Applications of arsine evolution methods to environmental analyses.

Because of its biological activity, arsenic is involved in an active global geochemical cycle. Arsenic has been found to be transferred to the atmosphere, at least in part, by evolution of trimethyl arsine and similar methyl arsenic compounds. Because of the environmental importance of the several arsenic forms [inorganic arsenic (III) and (V), methylarsonic acid, dimethylarsenic acid, trimethylarsine, methylarsine, and dimethylarsine], chemical methods for their analysis are needed. Sensitive methods are required because environmental concentrations encountered are generally in the range of 0.01 (or lower) to 3 ppb for natural waters and 1-6 ng As/m3 for arsenic in air. Arsine evolution by pH selective reduction permits specific analyses for inorganic As (III) and As (V). Methylarsenic acids may be reduced to corresponding methylarsines with sodium borohydride after which separation permits specific detection of these arsenic compounds. The most sensitive and selective methods combine reduction, separation, and emission type detectors. The intensity of arsenic atomic emission lines is observed. This type of detector provides a lower limit of detection down to 0.02 ng As per sample. The methods have been applied to a variety of environmental samples.


Arsenic in the drinking water of the city of Antofagasta: epidemiological and clinical study before and after the installation of a treatment plant.

This is a second report of epidemiological and clinical investigation, related to the arsenic health problem, unique in the world, occurring in the city of Antofagasta, Chile. The arsenic problem originates in the chronic contamination of water supply in the city during 12 years. This phenomena, investigated clinically and epidemiologically and first reported in 1971, prompted the installation of a water treatment plant. This report aims to evaluate the working efficiency of the plant. The study was carried out through the examination of arsenic content in hair and nail clipping samples of the inhabitants of Antofagasta and the determination of this element in cultivated vegetables and carbonated beverages. Also a clinical study in school children, looking for cutaneous lesions attributed to arsenicism, was made. Results are encouraging. They reveal that contamination persists but in significantly lower levels.


Some aspects of the environmental exposure to arsenic in Romania.

The main sources of arsenic emission in Romania are ore smelters and refineries. Arsenic determinations were carried out by the silver diethyldithiocarbamate spectrophotometric method on hair and urine samples taken from smelter workers and individuals residing in two polluted areas and three areas not polluted by arsenic. Arsenic in hair was found to be a more reliable biologic test than tests on urine, obviously reflecting the differences in arsenic concentrations in workroom air. Repeated determinations for arsenic content after 3 years revealed a twofold increased rate in the 48 re-examined workers. Hair arsenic analysis in people living in two locations near an ore smelter and a refinery indicated high-levels compared to those of individuals residing in nonpolluted areas. Epidemiological studies are necessary in order to ascertain effects of heavy arsenic exposure in relation with concurrent exposures to respiratory irritants and metals.


Effects and dose--response relationships of skin cancer and blackfoot disease with arsenic.

In a limited area on the southwest coast of Taiwan, where artesian well water with a high concentration of arsenic has been used for more than 60 years, a high prevalence of chronic arsenicism has been observed in recent years. The total population of this "endemic" area is approximately 100,000. A general survey of 40,421 inhabitants and follow-up of 1,108 patients with blackfoot disease were made. Blackfoot disease, so-termed locally, is a peripheral vascular disorder resulting in gangrene of the extremities, especially the feet. The overall prevalence rates for skin cancer was 10.6 per 1000, and for blackfoot disease 8.9 per 1000. Generally speaking, the prevalence increased steadily with age in both diseases. The prevalence rates for skin cancer and blackfoot disease increased with the arsenic content of well water, i.e., the higher the arsenic content, the more patients with skin cancer and blackfoot disease. A dose-response relationship between blackfoot disease and the duration of water intake was also noted. Furthermore, the degree of permanent impairment of function in the patient was directly related to duration of intake of arsenical water and to duration of such intake at the time of onset. The most common cause of death in the patients with skin cancer and blackfoot disease was carcinoma of various sites. The 5-year survival rate after the onset of blackfoot disease was 76.3%; the 10-year survival rate was 63.3% and 15-year survival rate, 52.2%. The 50% survival point was 16 years after onset of the disease.


Questions concerning environmental mobility of arsenic: needs for a chemical data base and means for speciation of trace organoarsenicals.

Biomethylation of metals, including arsenic, apparently occurs as a global process. Health control strategies therefore depend on accurate analysis of arsenic's environmental mobility. Determining to what extent biotransformations occur and how resultant organometal(loids) are sequestered in food chains requires sophistication beyond present-day total element determinations. Rather, active molecular forms of arsenic must be speciated for each environmental compartment, and it is necessary to quantify the dynamics of arsenic's mobility. Thus, new chemical facts are needed yielding rates of methylation or demethylation of arsenic; partition coefficients of organoarsenicals between air, water, and organic phases; and arsenic redox chemistry in polar media. NBS research in this context is reviewed with examples of recent results emphasizing speciation methodology. Topic areas discussed are: the nature of aquated methylarsenic species (NMR and laser-Raman spectroscopy); transport of methylarsenicals from aqueous media (gas chromatography-graphic furnace AA detection applied to metabolic Me3As formation); and speciation of involatile organoarsenicals in aqueous media (demonstration of HPLC utilizing element-specific AA detection and appraisal of electrochemical detectors).


Outbreak of chronic arsenic poisoning among retired workers from an arsenic mine in Japan.

Retired former workers of Matsuo Arsenic Mine of Miyazaki prefecture in Japan were subjected to extensive medical examination. The number of retired workers subjected to examination were 61 of 208 workers who were engaged in the works of the mine and were tracked down by the work rolls. These workers left the mine more than 15 years prior to the time of the examination. The main works in the mine were classified as mining, dressing of ores, refining, and clerical work. Several findings such as arsenodermatitis, depigmentation, performation of nasal septum, hyposmia, anosmia, and peripheral nervous disturbance attributed to exposure to arsenic were observed in 9 of 21 roasters who often worked in the arsenic kitchen. No characteristic findings of arsenic poisoning, that is, gastrointestinal disturbance, disorder of the cardiovascular system, hematopoietic disorders, or liver disturbance were observed in the retired workers. Another notable finding was that 8 cases diagnosed as pneumoconiosis were found in 18 miners.


Mortality experience in relation to a measured arsenic trioxide exposure.

This report examines the mortality experience of 527 men who retired from a copper smelter where they were exposed to airborne arsenic trioxide. Urinary arsenic values of all plant employees were determined in 1973, and the relative arsenic exposure in the various departments of the plant were determined. The relationship of airborne arsenic concentrations to urinary arsenic values was studied in a separate experiment, and the feasibility of using urinary arsenic values as a measure of arsenic exposure was established. The mortality experience of the cohort under study showed them to have a mortality 12.2% higher than was found for males of the same area at the same ages and in the same time period. The excess mortality was due chiefly to respiratory cancer. When the deaths were classified by total lifetime arsenic exposure, the respiratory cancer mortality was linearly related to the amount of exposure. The 1973 figures for arsenic exposure underestimated the exposure of the cohort group by a factor of possibly 10. Evidence was obtained which suggests that after removal from arsenic exposure, the risk of lung cancer declines. Certain of the data which are presented suggests there may be a threshold value for airborne arsenic trioxide exposure below which no adverse effects may be expected.


Studies of morbidity near a copper smelter.

Children living near a copper smelter in Tacoma, Washington, have been shown to have increased levels of urinary and hair arsenic. Studies of hearing, blood status and school attendance in exposed and nonexposed children failed to detect any differences in these parameters.


Mortality in a region surrounding an arsenic emitting plant.

The purpose of the investigation is to study whether an increased mortality from certain causes exists in an area around the Rönnskärsverken smelter works in northern Sweden. Founded in 1928, this metallurgical plant processing mainly nonferrous metals has since its initial operations been using ore with a high arsenic content. This has resulted in environmental pollution to air and water of arsenic, as well as other metals and sulfur dioxide. The causes of death for the population of two parishes in the vicinity of the plant were listed from the National Sedish Register on Death Causes. A reference area in the same part of Sweden with similar degree of urbanization, occupational profile, and age distribution was chosen. The causes of death for the two populations were followed during a period of 14 yr. A significantly higher mortality rate for lung cancer was noted in men in the exposed area. However, this increase was no longer significant when the occupationally exposed at Rönnskärsverken were excluded. The latter showed a highly significant excess mortality due to primary respiratory cancer.A continuation of this investigation in the form of a cohort study of both the mortality and cancer incidence is currently under way.


Arsenic levels in Oregon waters.

The arsenic content of well water in certain areas of Oregon can range up to 30 to 40 times the U.S.P.H.S. Drinking Water Standard of 1962, where concentrations in excess of 50 ppb are grounds for rejection. The elevated arsenic levels in water are postulated to be due to volcanic deposits. Wells in central Lane County, Oregon, that are known to contain arsenic rich water are in an area underlain by a particular group of sedimentary and volcanic rocks, which geologists have named the Fischer formation. The arsenic levels in water from wells ranged from no detectable amounts to 2,000 ppb. In general the deeper wells contained higher arsenic water. The high arsenic waters are characterized by the small amounts of calcium and magnesium in relation to that of sodium, a high content of boron, and a high pH. Water from some hot springs in other areas of Oregon was found to range as high as 900 ppb arsenic. Arsenic blood levels ranged from 32 ppb for people living in areas where water is low in arsenic to 250 ppb for those living in areas where water is known to contain high levels of arsenic. Some health problems associated with consumption of arsenic-rich water are discussed.


Chromosome aberrations in workers exposed to arsenic.

The occurrence of chromosome aberrations was studied in short-term cultured lymphocytes from nine workers exposed to arsenic at the Rönnskär smeltery in northern Sweden. In the smelter workers, 87 aberrations were found in 819 mitoses. The number of aberrations varied individually from 0 to 25 aberrations per 100 cells. In a control material 13 aberrations were found in 1012 mitoses. The frequency of chromosome aberrations was significantly increased among the smelter workers, but due to the simultaneous exposure to other agents the effect of arsenic per se can not be assessed with certainty.


Changes in the chemical speciation of arsenic following ingestion by man.

The concentrations of four chemical species of arsenic in urine were observed with time, after ingestion of three different chemical species of arsenic. The arsenic-rich substances ingested, including arsenite-rich wine, arsenate-rich drinking water, and crab meat which contained organo-arsenic compounds. After ingestion of arsenite-rich wine, approximately 10% of the arsenic was excreted as arsenite, but the majority of the arsenic was methylated to methylarsonic acid and dimethylarsinic acid and excreted. After ingestion of arsenate-rich water, elevated levels of both arsenate and dimethylarsinic acid were observed. When crab meat was ingested, none of these four arsenic species were observed at elevated levels until the urine was heated in 2N NaOH. After the hot base digestion, high levels of dimethylarsinic acid were detected in these samples. The apparent biological half-lives were on the order of 10 hr for inorganic arsenic and 30 hr for the methylated arsenic forms.


Disposition of 14C and/or 74As-cacodylic acid in rats after intravenous, intratracheal, or peroral administration.

The distribution, excretion, and possible metabolism of (14)C- and/or (74)As-cacodylic acid, an organoarsenical herbicide, was studied in rats following a single intravenous injection, intratracheal instillation or oral gavage. Male Sherman rats were dosed at levels ranging from 200 mg/kg to 120 mug/kg. The extent and rate of lung absorption was greater than gastrointestinal absorption. Concentrations in the liver and whole blood were higher after peroral dosing than intravenous administration. Levels observed in plasma and other tissues were similar after all three routes following the absorptive phase. The percent dose found in the whole blood, red blood cells, and plasma was similar for all doses given by these routes. Less than 0.1(1/2) of the administered dose was recovered as (14)CO(2) by any route at 24 hr after administration. Twenty-four hours after intravenous, intratracheal, and peroral administration, 71, 60, and 25%, respectively, was excreted in the urine. After intravenous administration of 200 mg/kg, sufficient (14)C-cacodylic acid was recovered in bile to account for the small amount excreted in the feces. Cacodylic acid is probably not metabolized to inorganic arsenic since the disposition of (14)C and (74)As-cacodylic acid were identical.Kinetic analyses of the plasma curve for (14)C-cacodylic acid (high dose) yielded three half-times; 0.014, 0.214 and 3.42 hr with an apparent volume of distribution of 15.3 ml. Highest initial concentrations were found in the whole blood, muscle, kidney, liver and lung. Levels in all tissues decreased rapidly, but remained high in whole blood. The red blood cells were found to be the major site of body burden of cacodylic acid.


Experimental studies on arsenic absorption routes in rats.

Pentavalent inorganic arsenic was introduced by intravenous, intratracheal, gastrointestinal, and skin application in doses 0.1 to 4.0 mg/kg in rats. Isotopic technics were applied by use of As(74). It was found that the dynamics of arsenic distribution in the body as well as the kinetics of its elimination in urine and feces varies very substantially, depending on the mode of administration. Intravenous administration of As causes immediate appearance of arsenic in most tissues and a slow decrease of its concentrations in time. Similar situations could be observed with intratracheal dosing, because arsenic is very rapidly absorbed from the site of administration. Concentration in tissues increases more slowly after gastrointestinal resorption. Skin application causes first the accumulation of arsenic in the skin and next continuous, slow transport from the skin into the blood stream. The rate of skin resorption was 1.14-33.1 mug/cm(2)-hr for 0.01-0.2M concentrations. The red blood cell level of arsenic is very substantial and does not change with time, which indicates the accumulation of arsenic in this tissue. The elimination of arsenic occurred chiefly in urine and feces, but the urine/feces ratio changed very substantially, depending on the route of administration. The kinetics of arsenic elimination in urine was multiphasic, being three-phase in case of intravenous and intratracheal administration and two-phase after gavage and skin resorption. After intravenous administration of As, the half-times of elimination were 2.5, 10, and 690 hr, respectively. Administration of selenium salts during the slow phase increased the rate of arsenic elimination. The straight-line relations found between the absorbed dose of arsenic and its blood or urine concentrations could serve as baselines for exposure tests for humans.


Carcinogenic, teratogenic, and mutagenic effects of arsenic.

This review outlines briefly the history and present status of the problem of carcinogenic, teratogenic and mutagenic effects of arsenic. Discrepancies between clinical observations and positive results of epidemiological studies and the experimental induction of cancer by arsenic are discussed. The present knowledge of the mechanism of teratogenic and mutagenic effects of arsenic is analyzed. The growing importance of arsenic as an environmental pollutant is demonstrated. Continuation of throughly organized epidemiological studies in regions with excessive arsenic exposure of the population and standardization of an epidemiological approach to this problem on an international basis are recommended. New approaches in experimental studies of the carcinogenicity of arsenic in combination with other known or suspected carcinogens are recommended as well.


Epidemiology and toxicology of arsenic poisoning in domestic animals.

Arsenic poisoning is one of the more important causes of heavy metal poisoning in domestic animals. Two species--dogs and cattle--are intoxicated more frequently than other animals; yet sporadic instances of poisoning have been observed in cats, horses, and pigs. Cases observed by veterinary clinicians are either peracute, acute, or chronic intoxications. Frequently the initial and only indication that a severe problem exists with peracute poisoning in a cattle herd is dead animals. Chronic intoxications are also observed in cattle. Acute intoxication is the most common form of arsenic poisoning observed and documented in the dog. Also intoxicated dogs were younger, i.e., 2-6 months of age. Arsenic is a severe alimentary tract irritant in domestic animals, and treatment in most instances consists mainly of symptomatic and supportive treatment. The source of intoxication, when it can be determined, is usually dips, sprays, powders, or vegetation contaminated by pesticides containing arsenic.


Preliminary experimental study on carcinogenicity of arsenic trioxide in rat lung.

To investigate carcinogenic or cocarcinogenic properties, copper ore (Kinkaseki) and flue dust collected from a metal refinery and arsenic trioxide (As2O3) were administered into the lung of male Wistar-King rats by an intratracheal instillation method. No squamous cell carcinoma of the lung was found among the rats given three arsenical substances, while adenoma or adenocarcinoma was observed. Squamous cell carcinoma of the lung was observed in rats, when copper ore, flue dust, and arsenic trioxide were instilled into the lung together with benzo[a]pyrene (B[a]P. The incidence of squamous cell carcinoma of the lung in rats exposed to Kinkaseki, flue dust, and As2O3 in addition to B[a]P was higher than that in rats given B[a]P alone. The results of this study indicate that solid arsenical substances, such as arsenic trioxide, metal ore and flue dust from a metal refinery, seemed to act on the carcinogenicity of B[a]P in a cocarcinogenic manner.


Effects of arsenic on pyruvate dehydrogenase activation.

Our studies illuminate a particular site of altered pyruvate utilization by liver mitochondria isolated from arsenic-fed rats. Initially, pyruvate dehydrogenase (PDH) levels were measured before and after in vitro activation. The liver homogenates were prepared from male rats given access to deionized drinking water solutions containing 0, 20, 40, and 85 ppm arsenic as sodium arsenate (As+5) for 3 and 6 weeks. After 3 weeks, the effects of arsenic at the highest dose level were pronounced on the basal activity (before activation), with inhibition up to 48% of the control values. The total PDH (after activation) was inhibited by 14, 15, and 28% of the control values at 20, 40, and 85 ppm As+5, respectively. A similar pattern of inhibition of PDH was observed at 6 weeks, although the inhibition was lower at the highest dose. This effect is probably a reflection of mitochondrial regeneration at this time and dose. The inhibition of PDH both before and after activation suggests a direct arsenic effect on pyruvate utilization which does not involve a lipoic acid moiety. Evidence is also presented which indicates an arsenic effect on the regulating kinase and/or phosphatase. The metabolic effects of impaired mitochondrial utilization by pyruvate are also discussed.


Effects of chronic arsenic exposure on hematopoietic function in adult mammalian liver.

In these studies the effects of ingested arsenic (As(+5)) on hepatic heme biosynthetic capability and hemoprotein function in adult male rats were investigated. Animals exposed for 6 weeks to 0, 20, 40, or 85 ppm sodium arsenate in the drinking water suffered depression of hepatic delta-aminolevulinic acid (ALA) synthetase and heme synthetase (ferrochelatase) activities, with maximal decreases to 67 and 55% of control levels, respectively, at 85 ppm. Concomitantly, urinary uroporphyrin levels were elevated by as much as 12 times, and coproporphyrin by as much as 9 times, control values. The rate of incorporation of (3)H-ALA into mitochondrial and microsomal hemes was depressed by 40-50% at 20 ppm but was increased with regard to controls by as much as 150% at the higher treatment levels. A similar biphasic pattern was observed in regard to (14)C-leucine incorporation into cellular membranal proteins. In contrast, the levels of ALA dehydratase, uroporphyrinogen I synthetase, aminopyrine demethylase, and cytochrome P-450 were not significantly changed in As(+5)-treated rats. These results support the hypothesis that chronic, low level, arsenic exposure results in selective inhibition of mitochondrial-bound heme biosynthetic pathway enzymes (ALA synthetase and heme synthetase) resulting in a substantial increase in urinary porphyrins, uniquely characterized by a greater increase in uroporphyrin than coproporphyrin levels. These changes occur independent of, or prior to, alterations in hepatic hemoprotein-dependent functions and may thus serve in the clinical analysis of pretoxic exposure to arsenic compounds in human populations.


Arsenic as a teratogenic agent.

Sodium arsenate induces developmental malformations in a variety of experimental animals. In the golden hamster, the intravenous (or intraperitoneal) administration of 20 mg/kg of sodium arsenate during day 8 to 9 of gestation induces a rather specific spectrum of congenital malformations. This period corresponds to the period of very rapid differentiation and major organogenesis in this animal. The spectrum of defects produced by arsenate in the hamster includes exencephaly, encephaloceles, skeletal defects, and malformations of the genito-urinary system. This teratogenic effect can be significantly reduced by the simultaneous administration of selenium. Recent studies in this laboratory have demonstrated the permeability of the placenta to 74As during the early critical stages of embryogenesis and the distribution of this isotope in maternal, placental and embryonic tissues. We have also recently demonstrated the marked potentiation of the teratogenic effect of sodium arsenate by subjecting the mothers to short periods of hyperthermia immediately following the administration of subteratogenic or minimal teratogenic levels of arsenate.


Effects in the mouse and rat of prenatal exposure to arsenic.

Initial experiments involving mouse development employed single IP injections of 45 mg/kg sodium arsenate on one of days 6-12 of gestation and produced a spectrum of developmental defects. Embryotoxicity was indicated by high prenatal mortality and decreased fetal weights. A chelating agent, 2,3-dimercaptopropanol (BAL), was then employed in an attempt to alleviate the adverse effects of prenatal arsenate. BAL was administered 4 hr before, concurrently with, or 4 hr after arsenate. All BAL treatments diminished arsenate-induced gross malformations and growth retardation; the concurrent treatment alleviated skeletal malformation. Injection of rats IP with arsenate has also been reported to result in teratogenicity, including renal agenesis. Further reports indicated that 40 mg/kg arsenate administered to mice by gavage on days 9-11 increased prenatal mortality, reduced fetal weights, and was associated with minor malformations. According to our recent work, however, single oral doses of arsenate must be around 120 mg/kg to cause prenatal toxicity. Multiple doses of 60 mg/kg on 3 days had little effect. Sodium arsenite has also been found to be fetotoxic and teratogenic. Such effects were seen at IP doses of 10-12 mg/kg.


Effects of arsenic cell metabolism and cell proliferation: cytogenetic and biochemical studies.

Chromosome analysis of lymphocytes from patients who had been exposed to arsenic showed frequent structural and numerical aberrations, even with an interval of decades since the last exposure. The in vitro addition of sodium arsenate induced the same chromosome changes--even to extreme of chromosome pulverizations--upon lymphocyte cultures from healthy subjects. Radioactive incorporation studies showed that arsenate was able to inhibit dose-dependently the incorporation of radioactively labeled nucleotide in RNA and DNA. Beyond that, arsenic blocked the cells in the S- and G2-phase. A general explanation for the inhibitory effect of inorganic arsenic on cell metabolism is the known strong affinity of arsenic to enzymes, especially to those containing sulfhydryl groups.


Effect of the combined action of selenium and arsenic on suspension culture of mice fibroblasts.

The protective influence of arsenic against the toxic action of selenium has been tested on suspension cultures of mice fibroblasts LA 115. The growth of the cells was observed after the isolated and combined action of sodium arsenite NaAsO2 and sodium selenite Na2SeO3. The concentration range of both substances in cultivation medium MEm (USOL) was 10(-5) -10(-11)M. The growth of treated cultures was analyzed daily during 5 days of exposure. From the results obtained, growth curves of the cell cultures were constructed and analyzed. The results of every determination were evaluated in relation to the corresponding control culture. The results obtained demonstrate that decreasing concentrations of arsenic enhanced its protective effect in the range of the concentrations used. In contrast, a low protective effect of selenium against arsenic was noted in the concentrations employed. The cell cultures have proved to be very suitable for toxicological studies of the combined effects of different substances.


Emissions of arsenic in Sweden and their reduction.

The role of arsenic in Sweden is generally described, including raw materials, exports/imports, products, consumption, etc. An attempt was also made to estimate the transport of arsenic in Sweden. The quantities of arsenic in raw materials, the emissions of arsenic from such processes as copper smelters and chemical industries, and the amounts of products containing arsenic were calculated. The studies show that a copper smelter is the main user of arsenical materials, the very largest emitting source and also the plant which manufacturers most arsenic products. A summary of measurements of arsenic in air, water and soil in Sweden has also been made. The concentrations near a smelter, in the Baltic, in cities and in "clean-air areas" are given. The efforts made to date to reduce the emissions of arsenic and the measures planned for the next few years are described. A reduction has already been achieved and a further rather large decrease will come, especially in arsenic levels in water. The possibilities of minimizing the use of materials and products containing arsenic is also discussed.


Industrial contributions of arsenic to the environment.

Arsenic is present in all copper, lead, and zinc sulfide ores and is carried along with those metals in the mining, milling and concentrating process. Separation, final concentration and refining of by-product arsenic as the trioxide is achieved at smelters. Arsenic is the essential consistent element of many compounds important and widely used in agriculture and wood preservation. Lesser amounts are used in metal alloys, glass-making, and feed additives. There is no significant recycling. Current levels of arsenic emissions to the atmosphere from smelters and power plants and ambient air concentrations are given as data of greatest environmental interest.


Quantities of lead producing health effects in humans: sources and bioavailability.

Levels of lead ingestion and inhalation producing increased body burden of lead and clinical toxicity in adults and children are compared with usual levels of exposure. The magnitude of lead exposure from air, water, and food is estimated. Sources of high level exposure to lead are described; urban street dirt, house dust, and paint are particularly common sources of high concentrations of lead. The bioavailability of different lead compounds is reviewed as well as factors affecting susceptibility to lead.


Virus activation by vitamin A and NO2 gas exposures in hamsters.

Hamsters exposed to 10 ppm NO2 for 5 hr once a week for 4 weeks while undergoing acute vitamin A deficiency showed much reduced epithelial cell regeneration in the terminal bronchioles. Quantitative analysis done by autoradiography and scintillation counting from lung tissues indicates much reduced cell kinetics occurring in terminal bronchiolar alveolar region. Alveolar necrosis was often observed and no type II cell reversion occurred. Virus particles were found within the alveolar epithelial plasma membrane.


Recent studies on biomethylation and demethylation of toxic elements.

Methylcobalamin (methyl-B12) has been implicated in the biomethylation of the heavy metals (mercury, tin, platinum, gold, and thallium) as well as the metalloids (arsenic, selenium, tellurium and sulfur). In addition, methylcobalamin has been shown to react with lead, but the lead-alkyl product is unstable in water. Details of the kinetics and mechanisms for biomethylation of arsenic are presented, with special emphasis on synergistic reactions between metal and metalloids in different oxidation states. This study explains why synergistic, or antagonistic, processes can occur when one toxic element reacts in the presence of another. The relative importance of biomethylation reactions involving methylcobalamin will be compared to those reactions where S-adenosylmethionine is involved.


Occurrence and transformation of arsenic in the marine environment.

Among the trace elements, arsenic appears to possess a unique position in the environment. When comparing terrestrial and marine organisms there seems to be a significant difference between both level and chemical forms of arsenic. The level of arsenic in terrestrial organisms is seldom above 1 ppm (dry material) whereas the corresponding values for marine organisms vary from several parts per million up to more than 100 ppm. Furthermore, results so far show that marine organisms are able to convert inorganic arsenic into organic arsenic compounds. No evidence points to a corresponding ability in the terrestrial ones. In the aquatic organisms the arsenic is present as both lipid soluble and water soluble compounds. The water-soluble organic arsenic compounds have a basic character and are very stable to chemical and metabolic breakdown.


Flameless atomic absorption (FAA) and gas-liquid chromatographic studies in arsenic bioanalysis.

Procedures for assessment of arsenic in soft tissue by use of flameless atomic absorption (FAA) and gas-liquid chromatography (GLC), have been evolved, with special emphasis on the analytical distinction among inorganic, monomethyl-, and dimethylarsenic in several oxidation states. The chemical bases for such speciation reside in several properties of the arsenicals under consideration: (1) pentavalent inorganic arsenic, methylarsonic, and cacodylic acid are not extracted from tissue matter made strongly acid with hydrochloric acid, while the corresponding trivalent forms (as halides) are extracted; (2) chloroform extracts of samples treated under reducing conditions (HCl-KI) retain organoarsenicals when these extracts are re-extracted with water, but do not when aqueous solutions of oxidants are employed; (3) reduced cacodylate (dimethylarsinous acid) is not detected in the graphite furnace of an FAA unit under conditions selected, while cacodylate can be so detected. For GLC studies, monomethyl- and dimethylarsenic are simultaneously measured as the diethyldithiocarbamate complexes with an instrument equipped for electron-capture detection and containing a glass column packed with silanized 5% OV-17 on Anakrom A.S.


Implications of inorganic/organic interconversion on fluxes of arsenic in marine food webs.

An organic form of arsenic is commonly encountered in marine organisms; in greysole and shrimp, it accounted for all arsenic found in muscle tissue. It has been isolated from flounder tissue by two independent procedures; it was hydrophilic, cationic, and was not decomposed to inorganic arsenic by hot nitric and sulfuric acids. NMR spectroscopy indicated all nonexchangeable protons to be equivalent; they behaved more like N-methyl protons than As-methyl protons. High-resolution mass spectroscopy from a heated probe yielded a spectrum corresponding to tetramethylarsonium (AsMe4+); the authentic ion, however, had TLC and ion-exchange behavior different from that of the natural product. Infrared spectrometry likewise produced conflicting or uninterpretable data. Decomposition of the compound for analytical purposes was accomplished by dry ashing under oxidizing conditions. Sea urchins, like trout, converted arsenic to an organic form, but to a more limited degree. Arsenic found naturally in sea urchins and in a species of macroalga was also organic. In individual containers, sea urchins were fed on the alga for 7 weeks. During this time they consumed 0.203 +/- 0.075 mg total As and excreted only 0.036 +/- 0.015 mg as feces. Measurement of inorganic As in the seawater did not account for the discrepancy, but measurements of total As did (0.202 +/- 0.095 mg). Sea urchins, like humans, appear to be able to rapidly excrete these organic forms of arsenic.


Characterization of arsenic compounds formed by Daphnia magna and Tetraselmis chuii from inorganic arsenate.

Experiments to grow Tetraselmis chuii (a marine alga) and Daphnia magna in the presence of inorganic arsenate are described. The algae incorporate arsenic rather efficiently and form a lipid-soluble organic arsenic compound. T. chuii has been successfully mass cultured in a medium containing 10 ppm arsenic as arsenate. Daphnia magna was cultured in a medium containing 74As-labeled H3AsO4 and 1 ppm Na2HAsO4 expressed as arsenic. The arsenic metabolites were extracted with a chloroform-methanol solution and isolated by using column and thin-layer chromatography. TLC analysis of the metabolites revealed the presence of a 74As-containing product which migrated with phosphatidylethanolamine. This product was hydrolyzed with the phospholipases A, C, and D. The experimental results are not inconsistent with the presence of an arsenocholine moiety in the lipids. Arsenocholine, arsenobetaine, and acetylarsenocholine have been synthesized and will serve as reference substances in the chromatography experiments. The preparation of arsenocholine-containing lipids is in progress.


Occurrence and distribution of arsenic in soils and plants.

Inorganic arsenicals have been used in agriculture as pesticides or defoliants for many years and, in localized areas, oxides of arsenic have contaminated soils as a result of fallout from ore-smelting operations and coal-fired power plants. Use of inorganic arsenicals is no longer permitted in most agricultural operations, and recent air pollution controls have markedly reduced contamination from smelters. Thus, this paper will concentrate on the effect of past applications on arsenic accumulation in soil, phytotoxicity to and uptake by plants as influenced by soil properties, and alleviation of the deleterious effects of arsenic. Once incorporated into the soil, inorganic arsenical pesticides and arsenic oxides revert to arsenates, except where the soil is under reducing conditions. The arsenate ion has properties similar to that of orthophosphate, and is readily sorbed by iron and aluminum components. This reaction greatly restricts the downward movement (leaching) of arsenic in soils and the availability of arsenic to plants. Several methods of estimating plant available arsenic in soils have been developed. They involve extraction of the soil with reagents used to estimate phosphorus availability. This extractable arsenic is reasonably well correlated with reduced plant growth by, and plant uptake of arsenic. For most plants, levels of arsenic in the edible portion of the plant are well below the critical concentration for animal or human consumption, even when severe phytotoxicity occurs. Alleviation of arsenic phytotoxicity has been attempted by increasing the soil pH, by use of iron or aluminum sulfate, by desorbing arsenate with phosphate and subsequent leaching, and by cultural practices such as deep plowing. Only limited benefits have accrued from these procedures the cost of which is often prohibitively high. Since attempts to reduce arsenic toxicity have not been very successful, its excessive accumulation in soils should be avoided.


Fate of arsenicals in different environmental substrates.

The current knowledge of arsenic (As) transformations in the environment, as well as some gaps in this knowledge, are reviewed. These transformations involve As chemical and biochemical transformations in air, waters, sediments, and soils. Arsenic moves in a dispersive manner through air and water and is in physical and chemical equilibrium in many substrates. It is oxidized, reduced, methylated, volatilized, incorporated into biotic tissues, excreted, adsorbed, and desorbed. Oceanic sediments become the eventual sink for As. The rates of As movement and transformation vary with environmental conditions. Besides inorganic As, various methylated arsenicals are found naturally at environmentally sensitive equilibrium concentrations, which are probably maintained biotically. An As-transformation model has been constructed from rate constants derived from field observations. The environmental factors affecting these rate constants are discussed.


Levels of arsenic in the United States food supply.

At the present time, the Food and Drug Administration (FDA) accords the highest priority to mercury, lead, cadmium, arsenic, selenium, and zinc in its program on toxic elements in foods. The only regulatory levels for arsenic in foods in the U. S. are the tolerances which have been established for its residues in specified foods, resulting from the application of arsenical pesticides on food and feed crops and from animal feed additives. FDA has monitored for arsenic in its Total Diet Survey since the inception of this program. The data from this program indicate that the average daily intake for arsenic (as As(2)O(3)) has decreased from about 130 mug/day in 1968 to about 20 mug/day in 1974. Most of the arsenic is found in the meat-fish-poultry food class of the total diet. In individual foods, the highest levels were found in fish, with a mean level of about 1.5 ppm (as As(2)O(3)) in the edible portion of finfish. Much lower levels were found in all the other food types analyzed; of these, the highest levels found were a mean level of 0.08 ppm in chicken and 0.16 ppm in rice. FDA toxicologists do not believe that the average daily intake of arsenic, or its levels in the different food commodities, pose a hazard to the consumer.


Airborne arsenic exposure and excretion of methylated arsenic compounds.

First void urine samples were collected from copper smelter workers exposed to inorganic arsenic and from unexposed controls. Arsenic compounds (As (III), As (V), methylarsonic acid and dimethylarsinic acid) in these samples were analyzed by selective volatilization as arsines with determination of arsenic by plasma excitation emission spectrometry. On the day preceding the urine sample collection a breathing zone measurement was made of respirable arsenic particulates for each subject. It was found that all of the subjects, including the controls excreted arsenic primarily as methylated species. Approximately 50% of the total arsenic was excreted as dimethylarsinic acid and 20% as methylarsonic acid. Slight differences in the proportion of various arsenic compounds were observed with varying levels of inorganic arsenic exposure. Amounts of arsenic species were all closely correlated with each other and with exposure. Irrespirable particulate exposures were measured on a subset of high exposure workers. Irrespirable arsenic was found to be more closely correlated with excretion of arsenic compounds than was respirable arsenic.


Test of environmental exposure to arsenic and hearing changes in exposed children.

Arsenic determination was carried out on hair, urine, and blood samples taken from groups of 10-year-old boys, each numbering 20 to 25 individuals, residing in a region polluted by arsenic. In all the examined materials considerably elevated concentrations of arsenic were found. The relation of the observed levels of arsenic to the distance of the place of residence up to a distance of more than 30 km from the source of the emissions was studied. On the basis of the results obtained, the most advantageous material for estimation of nonoccupational exposure to arsenic seems to be hair, in spite of some problems with the decontamination procedure involved. Considerable variability among individual arsenic values in the hair makes group examination a necessity. Hearing changes were analyzed in a group of 56 10-year old children residing near a power plant burning local coal of high arsenic content. The results of both audiometric and clinical examination were compared with those of control group numbering 51 children of the same age living outside the polluted area. The highly standardized audiometric and clinical examination were completed with a questionnaire analysis concerning the personal medical histories of the children. The obtained data were elaborated statistically by means of the chi(2)- test. In the case of air conduction, important hearing losses were found at frequencies of 125, 250 and 8000 Hz, especially at the lowest frequency range. Significant degrees of hearing loss were found in bone conduction as well as in the corresponding ranges of frequencies. The high statistical significance of the hearing impairments found points to very low probability of their being only an "accidental" finding. The possibility of toxic damage to the ear cannot yet be excluded.


Reaction of human choriomammotropin with hydrogen peroxide.

Treatment of human choriomammotropin with hydrogen peroxide in the absence of denaturant was found to oxidize five of its six methionine residues to sulfoxide; the residue not oxidized was found to be methionine-170. This derivative was identical to the native hormone by exclusion chromatography, circular dichroism spectra, and rate of tryptic digestion, but suffered a very substantial drop in biological activity. In the presence of 8 M urea all of the methionines could be oxidized with hydrogen peroxide or alkylated with iodoacetic acid. The physical properties of these completely methionine-modified derivatives were significantly changed and biological activity had again been very substantially decreased. In control experiments, treatment of the native hormone with 8 M urea did not affect its physical, spectral or biological properties. Amino acid analysis of the derivatives was completely in accord with that expected.


Degradation of nucleic acids in cell lysates by S1 nuclease in the presence of 9 M urea and sodium dodecylsulfate.

Single-strand-specific nuclease S1 from Aspergillus oryzae is shown to degrade DNA and RNA in lysates of HeLa cells in the presence of 9 M urea and sodium dodecylsulfate. Free dodecylsulfate inhibits S1 nuclease. However, if the detergent is complexed with proteins prior to the addition of the enzyme, S1 nuclease can degrade nucleic acids at dodecylsulfate concentrations which would inhibit the enzyme completely if no other proteins were present. In lysates prepared from HeLa cells by treatment with dodecylsulfate and urea, the detergent is complexed by cellular proteins and therefore S1 nuclease can be used to digest DNA and RNA. DNA can be completely degraded but, even after heat-denaturation, only 60% of the cellular RNA is converted into acid-soluble material. Analysis of the acid-insoluble RNA fragments by gel filtration reveals that the majority of the degradation products is approximately of tRNA size.


Size distribution of rat liver nuclear RNA containing mRNA sequences.

Total rat liver poly(A)-containing polysomal mRNA was size-fractionated on polyacrylamide gels in 98% formamide. Complementary DNA (cDNA) was prepared from the 8--14-S mRNA fraction and separated into sequences representing abundant and non-abundant mRNAs. The cDNA complementary to the abundant small mRNA of the rat liver cell (approximately 20 species) was hybridized to nuclear RNA of different lengths to determine the size distribution of nuclear RNA molecules which contain these messenger sequences. It was found that: 1. All abundant 8--14-S poly(A)-containing mRNAs have larger nuclear precursor molecules; 20% of the different messenger sequences are found in nuclear RNA of several times their cytoplasmic length. 2. 70% of the mass of the examined nuclear messenger sequences is in RNA molecules of a size similar to their polysomal mRNA; 30% are in larger than 18-S RNA and 2% are between 37 S and 44 S. 3. The majority of small messenger-containing RNA molecules in the RNA prepared from isolated nuclei are of true nuclear origin, since their frequency distribution differs significantly from that of the polysomal 8--14-S mRNA.


The lipid bilayer structure of the abnormal human plasma lipoprotein X. An X-ray small-angle-scattering study.

The structure of the abnormal lipoprotein X occurring in the plasma of patients with obstructive jaundice was investigated by X-ray small-angle scattering. The data were analyzed by discussing the distance distribution functions obtained directly from the experimental data by Fourier transformation, involving no a priori assumptions. The results provide evidence for lipoprotein X being essentially a random distribution of lamellae with a thickness of 5.1 nm and are consistent with hollow spherical (vesicular) structures of outer diameters greater than 30 nm with some overall size heterogeneity. Under the experimental conditions chosen, lipoprotein concentrations between 0.01 and 0.18 g/ml in in buffers of low ionic strength, lateral stacking as observed in negative-stain electron microscopy does not occur. The electron density profile perpendicular to the lamellar plane indicates that a lipid bilayer is the underlying structural principle, with the protein moieties partly bound within the polar head-group regions and partly occluded in soluble form in the vesicle interior.


The purification and properties of two low-molecular-weight proteins required for the initiation of translation in ascites tumour cells.

A fractionated cell-free protein-synthesising system from Krebs II ascites tumour cells is described. It is dependent on the addition of exogenous mRNA. In this system the translation of natural mRNAs requires the presence of four initiation factors: the high-molecular-weight complex IF-M3, IFEMC and two low-molecular-weight proteins IF-Malpha and IF-Mbeta. None of these factors are required for the translation of the synthetic messenger poly(A,U,G). The purification of IF-Malpha and IF-Mbeta was achieved by the use of gel and ion-exchange chromatography. Analysis of the purified proteins by sodium dodecyl sulphate/polyacrylamide gel electrophoresis showed that the molecular weight of IF-Malpha is 19,000 and that of IF-Mbeta is 15,000. The initiation factor IF-E1 isolated from rabbit reticulocytes can substitute for IF-Mbeta in the translation of encephalomyocarditis virus RNA. IF-Malpha does not correspond to any previously recognised eukaryotic initiation factor.


Studies on the role and mode of operation of the very-lysine-rich histone H1 in eukaryote chromatin. The three structural regions of the histone H1 molecule.

Limited digestion with trypsin of both calf thymus H1 histone and the fragment 1--120 of the H1 molecule has resulted in the isolation of the fragment 35--120. This fragment assumes a globular structure under physiological conditions of pH and ionic strength. The variable N-terminal portion of the molecule, up to residue 34, is not required for the formation of the H1 globular structure. Proton nuclear magnetic resonance (NMR) and ultracentrifugation studies show that the H1 histone molecule consists of three distinct structural domains under structuring conditions: a random coil 'nose' consisting of 35 to 40 residues from the N-terminal end; a globular 'head' involving the next approximately 80 residues; and a random-coil 'tail' of the remainder of the molecule.


A simple method for ECG and VCG assessment of the severity of pulmonary valve stenosis.

In patients with isolated pulmonary valve stenosis, the right ventricular (RV) hypertrophy is related to the hemodynamic severity of their lesions. We estimated the peak RV pressure noninvasively in 112 patients with isolated pulmonary valve stenosis by a Frank lead vectorcardiogram (VCG), an orthogonal electrocardiogram (ECG), and a standard scalar ECG. In 78 randomly assigned patients, 10 ECG measurements and 13 VCG measurements were correlated with the peak RV pressure at cardiac catheterization; the best multiple linear regression equation used the R wave in standard lead 1 (ECG), maximal rightward voltage in the terminal part of the frontal vector loop (VCG), and the Q wave in the orthogonal Z lead, giving R = 0.66 (SEM 25). The equation was validated in the other 34 patients; correlation of estimated with actual peak RV pressure was r = 0.64. A nomogram for clinical use was devised from this regression equation.


Exercise ECG and case history in the diagnosis of latent coronary heart disease among presumably healthy middle-aged men.

Previously undetected coronary heart disease (CHD) was suspected in 152 of 2014 presumably healthy males aged 40-59 yr. 63 had angina pectoris, 100 a positive exercise test and only 13 both angina and a positive exercise test. Coronary angiography was performed in 105 cases of whom 69 had a positive angiogram. A 2:1 proportion of true vs false positive diagnoses of CHD was found regardless of whether the diagnosis was suspected by the exercise test and/or the case history. Exercise test data show that CHD-suspect individuals differ only marginally from normal age counterparts irrespective of angiographic findings. However, of the 12 with a positive exercise ECG and maximal pulse greater than or equal to 2 SD below normal mean, 10 had pathologic angiograms. Of 58 with positive exercise ECGs and pathological angiograms, 43 had work performance below normal mean. By using a target pulse of 150 beats/minute 69% of the positive exercise ECGs had remained undisclosed.


Arterial blood supply to a left artrial myxoma diagnosed by coronary arteriography: report of a case.

A patient with left atrial myxoma is described. Selective coronary arteriography visualized a cluster of abnormal vessels representing the vascularization of the tumoral mass localized in the left atrium.


Criss-cross heart with congenitally corrected transposition: report of a case with d-transposed aorta and ventricular preexcitation.

A case is described of corrected transposition in a situs solitus individual, in which, despite the presence of atrioventricular discordance (1-bulboventricular looping), the aorta was right-sided. A ventricular septal defect and pulmonary stenosis were also present, and the case had been erroneously diagnosed during life as complete transposition. The true diagnosis was not appreciated at surgery, and correction of the anomaly was attempted using a modification of Fontan's operation. The criss-cross atrioventricular connections were only fully appreciated at autopsy. The patient also exhibited ventricular preexcitation of Wolff-Parkinson-White variety type A. Histopathological examination revealed the presence of two atrioventricular nodes in the right atrium, each contacting the ventricular conduction tissue which was distributed to the morphologically appropriate ventricles. In addition, a left-sided accessory atrioventricular connection perforated the anulus of the left-sided, morphologically tricuspid, valve.


[Growth and reproduction of the chinchilla-age at vaginal opening, oestrous cycle, gestation period, litter size, sex ratio, and diseases frequently encountered (author's transl)].

The paper deals with observations on growth and reproduction of the chinchilla in recent 4 years started from 1966 at this laboratory. There were large variations in age of vaginal opening (less than 71 days-308 days) with an average of 173.2+/-57.6 days in 45 females. The average length of 100 oestrus cycles in 24 females was 35.7+/-7.9 (15-62) days. The mean period of 5 gestations in 5 females was 110.4 (108-112) days. Eighty-one out of 123 litters were born between March and August during 3 years, and parturition never occurs in December. The most suitable season for reproduction of chinchillas may be from January to April, and a summer anoestrous seems to be present in August to early September as reported by Weir. The litter size ranged from 1 to 4 with a mode of 2 (46.3%) and an average of 1.90+/-0.76. More male kids were produced at birth at this laboratory, and sex ratio was 133.7 (98 females and 131 males). In 1973, 37 chinchillas gave birth to 71 kids with an average litter size of 1.92, and 59 of them were successfully weaned (1.59 per litter). Of these kids, 50 (1.35 per liter) attained 240 days of age (adulthood). Among 91 subjected to investigation for causes of death, 23 (25.3%) were dead during newborn period, and 9 and 5 adults were dead of malocclusion (9.9%) and the prolapse of rectum respectively.


[Inheritance and growth of mouse mutation brachypodism (brp) (author's transl)].

A mouse mutation brachypodism was detected in an inbred strain of mouse (NC) maintained by National Institute of Animal Health (Ministry of Agriculture). An attempt was made in this paper to reveal the mode of inheritance and the pattern of growth of this mutant. 1. From the results of crossing tests, it might be concluded that an autosomal recessive gene (brp, linkage group V) was responsible for the occurrence of the brachypodism. 2. Body weights of brachypod mice (brp/brp) were smaller than those of normal mice (+/brp) from the delivery, and this tendency was remarkable with age.


[Biological characteristics of miniature "Shiba" goats (author's transl)].

Practical informations of miniature "Shiba" goats, that have since long been bred for meat consumption in Kyushu District of Japan, were provided for using as laboratory animals. Nine years ago, some pairs of the goats, were introduced to Stock Farm of Tokyo University from a National Institute. Thereafter, they were successfully bred and increased in number and were distributed to many laboratories for researchers. The "Shiba" goat is white coloured, horned, and much smaller in size while sharing common characteristics with full size goats. The handling is much easier with less amount of food consumption. The body weight are 24 to 28 kg and 15 to 22 kg in males and females, respectively. They are obedient and have a strong resistance to diseases, including cerebral nematodiasis. The productive characteristics are as follows: 1) Continuous breeder, 2) Age at the first parturition: 13 months, 3) Gestation period: 5 months, 4) Litter size: 1.84, 5) Rate of raising: nearly all, 6) Delivery interval: 8 months, 7) No intersexality. Hematological data were also demonstrated.


The influence of feeding patterns on the growth of rat.

To see the influence of a restricted diet and a meal feeding for the growing Wistar rats were subjected to three types of feeding patterns, free access feeding, three meals and one meal per day. The animals of each feeding pattern group were fed either unrestricted and restricted amount of diet. The restricted group received only 60% weight of the diet taken by the unrestricted groups. The growth of the animals having free access to the restricted amount of diet was almost similar to that of those having received the restricted amount of diet three meals per day rather than to the group fed the unrestricted diet once per day. The former group seemed to be a "nibbler type" rather than a "meal feeder type".


Hereditary anophthalmia in the progeny of an X-irradiated female rat.

Inherited anophthalmia was observed in the progeny of a female rat irradiated with 50 R of X-irradiation at 17 days of age. Observations on the inheritance of the condition indicated that this anophthalmia can be considered as the result of polygenic factors with incomplete penetrance.


Control of Pseudomonas aeruginosa infection in laboratory mice with gentamicin.

Pseudomonas aeruginosa infection in laboratory mice was successfully eradicated by oral treatment of gentamicin, 1.0 g per liter of drinking water for 3 days.


[Long term surveys on Tyzzer's disease in three rat breeder colonies (author's transl)].

Retired rats of SD strain from three breeder colonies (A, B and C) were monthly monitored for CF antibody to Tyzzer's organism for 2 to 6 years. In colony A, antibody-positive rats were found at frequencies ranging from 5 tp 100% with a single peak during about one year without any detectable signs of apparent disease. However, in colony B, in spite of the outbreak of the disease, antibody-positive animals were only sporadically detected during about 4 years after the outbreak. Thereafter, in this colony, the antibody was not demonstrated in all animals examined for 2 years, and susceptibility to the disease of 3-week-old rats was the same as that of ones from one-infected colony. Cortisone test did not suggest the infection. In colony C, no antibody-positive rats were detected for 3 years.


Changes in phospholipid composition of Nocardia polychromogenes during temperature adaptation.

The effect of growth temperature on the phospholipid composition of Nocardia polychromogenes has been examined. When the growth temperature was decreased from 37 degrees C to 27 degrees C, there was a large decrease in phosphatidyl ethanolamine with an increase in cardiolipin and phosphoinositides. These changes are discussed in context with the control of membrane fluidity.


A low molecular weight glycosaminoglycan from the human aorta.

A low mol. wt, dialyzable glycosaminoglycan was isolated from human aorta and was found to be homogeneous on 2 dimensional electrophoresis. As judged by its electrophoretic mobilities and its hydrolysis by chondroitin sulfatase ABC, it was concluded that this hitherto unknown glycosaminoglycan is an oversulfated chondroitin sulfate.


The synthesis of total and specific glycosaminoglycans during development of experimental liver cirrhosis.

During hepatic fibrogenesis induced by long-term administration of thioacetamide, the synthesis of chondroitin 4,6-sulfate and hyaluronic acid was strongly enhanced; the formation of heparan sulfate comprising at least 70% of total liver GAG synthesis and of a keratan-sulfate-like fraction was stimulated 1.7 fold. Formation of dermatan-sulfate in liver could not be detected.


Robertsonian fusion leading to the formation of stable dicentric chromosome in an ascites cell line of the mouse.

The dicentric nature of a marker metacentric chromosome originated by robertsonian fusion has been established in the ascites cells of mouse sarcoma 180. C-banding analysis has revealed that the metacentric is actually a dicentric with 2 closely situated C-positive heterochromatic zones. The nature of the centromeres and the NF value of the cell indicate that this meta-dicentric marker has originated by breakage and fusion within each of the short arms of 2 acrocentric chromosomes.


A note on the evolution of the transducer mechanism of the vertebrate retinal rod.

The Ca2+-gating mechanism that is the key component of membrane excitability in paramecium has recently been localized on the cilia of this animal. Such a finding shows how the change in Ca2+ permeability (which is the probable consequence of the photoisomerization of rhodopsin) of the discs of the outer segments of the retinal rods could have evolved.


Chromatin ultrastructure of lower vertebrates.

Meiotic and mitotic chromosomes from amphibians and snakes were studied by electron microscopy. By using water spreading, preceded by a mild NaCl pretreatment, we showed: 1. 'Beads on a string' arrangement of the chromatin fibres; 2. The presence of loops at pachytene chromomeres as well as during metaphase of both mitosis and first meiosis; 3. Transcriptional activity for non-ribosomal RNA on peripheral loops during the middle pachytene.


Morphological appearance of fat in the epithelial cells of different portions of the intestines in mice.

Absorption of administered fat in the small intestine of mice as judged morphologically in semi-thin sections demonstrates a proximal to distal gradient, being greatest in the mid-jejunal area, but less in the duodenum and ileum. The criterion of the amount and size of fat droplets in intestinal epithelial cells, however, does not necessarily give a reliable indication of the efficiency of fat absorption in the different segments of the intestine.


The relative sensitivity of pulmonary parenchymal cells to 239plutonium dioxide.

Alpha particles inhaled by mice affect primarily type II epithelial cells, whereas interstitial mononuclears, alveolar macrophages and type I epitehlium are much more resistant and apparently react secondarily. The cellular responses, qualitative and quantitative, exhibit a time-dose relationship.


Effects of some oligopeptides, consisting of aromatic amino acids, on the excitability of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac).

L-Phe-L-Tyr and L-Lys-L-Phe-L-Tyr showed a marked inhibitory effect (not chloride-dependent) on the excitability of an identifiable giant neurone (the TAN) of Achatina fulica Férussac, while L-Tyr-L-phe, L-Tyr-L-Tyr, L-Phe-L-Phe, L-Lys-L-Phe and Z-L-Phe-L-Tyr (Z-: carbobenzoxy) had no effect.


Inhibitory effect of taurine on decrease in the inotropic action of ouabain at high concentrations in isolated atria.

In vitro, taurine was shown to inhibit the decrease in the inotropic effect of ouabain at large doses in the normal and also low K+ medium in which this decrease in the inotropism of ouabain was facilitated. This inhibitory effect of taurine was, at least in part, due to the inhibition of the efflux of intracellular K+ in the isolated heart.


Effect of harmaline on the cerebello-rubral system.

Harmaline induces synchronous rhythms in both the cerebellum and the red nucleus of the rabbit. The level of synchronization is lower in the red nucleus than in the cerebellar cortex, probably because the cerebello-rubral pathway and the red nucleus neurons only participate poorly in the harmaline-induced olivo-cerebellar rhythm.


Metaraminol uptake by human thrombocytes: a poor model for neuronal noradrenaline uptake.

The IC50 of a number of antidepressants and related drugs on the uptake of 1-metaraminol and serotonin into human thrombocytes, and of noradrenaline and serotonin into rat midbrain synaptosomes were compared. In accordance with previous reports, it was found that platelets provide a good model for the study of neuronal uptake of serotonin. Platelet uptake of 1-metaraminol, although correlated to some extent with noradrenaline uptake into synaptosomes, seems to be an unsatisfactory model for the neuronal uptake of the latter amine.


Elevation of serum xanthine oxidase activity following halothane anesthesia in man.

Halothane, but not methoxyflurane, was found to cause specific hepatocellular damage, the hepatotoxicity being prompt but transient. The hepatotoxicity was demonstrated by the elevation in the serum activity of xanthine oxidase, a highly sensitive marker for acute liver damage.


Toxicity of Parthenium hysterophorus L. to cattle and buffaloes.

Parthenium hysterophorus L., when fed to buffalo bull calves and cross bred bull calves resulted in acute toxicity leading to death. The former animals developed severe dermatitis. Autopsy revealed ulceration of alimentary tract. Extensive pathological changes were noticed in liver, kidney and skin.


The acetylcholinesterase reaction and catecholamine fluorescence in the glomus cells of rat carotid body.

The presence of both acetylcholinesterase reaction and glyoxylic acid-induced fluorescence of catecholamines in the same glomus cells of rat carotid body was demonstrated using combined histochemical methods. A suggestion is made that the glomus cells have both excitatory and inhibitory effects on the chemosensory nerve via acetylcholine and catecholamines, respectively.


Dietary restriction and fetal development.

The effect of deficient nutrition of pregnant Wistar rats on the fetal weight has been studied. It has been established that the fetal weight of the group of rats fed with a restricted amount of stock diet lags behind the fetal weight of the group receiving unrestricted amounts of the same stock diet. The differences in weight between the 2 groups were, on each day of the observation period, significant at the level of p less than 0.05 and p less than 0.01, respectively.


Effect of actinomycin D on the quail oocyte nucleolus during meiotic prophase I.

Actinomycine D alters profoundly the distribution of the nucleolar constituents in the quail oocyte at prophase I of meiosis. As a consequence of nucleolar segregation, the normally existing relations between the nucleolus fibrillar centers and the microchromosomes are ruptured. The relations between the fibrillar center and the dense fibrills which surround it remain intact, suggesting that they constitute together a functional unit.


Early foetal thrombosis induced by thalidomide in mouse: possible explanation for teratogenicity.

Mouse foetuses were treated by Thalidomide on days 11-12 in order to verify whether the drug would induce blood abnormalities leading to circulatory troubles. About 18% of the treated foetuses showed both severe limb haemorrhages on day 14, and obvious alterations of the nucleated red blood cells of vitelline origin. These blood abnormalities, occurring suddenly during the well-known 'critical stage' of foetal development, could be responsible for circulatory blocks leading to necrosis.


The chemokinetic effect of serum albumin.

Experiments performed by means of time lapse cinematography or the filter technique show that human serum albumin has marked chemokinetic effects on neutrophil cultured in Gey's solution. The average speed of the cells, as well as the proportion of neutrophils showing locomotion, is increased. Enhanced locomotion correlates with decreased attachment to the substratum as determined by morphological and functional criteria.


Clinical and immunological studies on persons exposed to Parthenium hysterophorus L.

Studies on 300 persons subjected by occupational hazard to the allergenic weed, Parthenium hysterophorus L. for periods ranging from 3 to 12 months revealed that 4% of them developed contact dermatitis of the exposed parts of the body, while 56% of them got sensitized to the weed without apparently exhibiting any dermatitis. None of them suffered from allergic manifestations like rhinitis or bronchial asthma during the period of study which extended for 2 years.


Effects of constant light exposure and blindness on the oxidative metabolism of selected brain areas in male rats.

Male rats were housed in continuous illumination or blinded when 21 day-old and killed 69 days later. The continuous illumination exposure increased the weights of testes and sex accessory organs and reduced the pineal gland weight. Blindness decreased weights of testes, sex accessory organs and anterior pituitary. The oxygen consumption rate of the hypothalamus was higher in the blinded animals than in the controls and lower in the continuously illuminated rats. No one of such groups showed significant changes in the oxygen consumption by either the amygdala or the hippocampus.


Central aromatization of testosterone in testicular feminized mice.

Aromatization of testosterone was examined in hypothalamic and cerebral cortex tissues from 32 mice--10 normal males, 10 normal females, 2 carrying the testicular feminized gene (Tfm) and 10 Tfm with the modifying (Ohv) gene. Total aromatization was 1.5 times greater in normal males than females. In both forms of Tfm, conversions were equal and similar to normal females.


Adrenalectomy, ovarian HCG-binding and the onset of female puberty in the rat.

The delay of puberty onset in female rats adrenalectomized before the 25th day of age is due neither to changes in the number of ovarian HCG-receptors nor to an altered hormone affinity of these receptors. It is assumed that glucocorticoids act on an intracellular level in the ovarian cells, possibly by alterations of cyclic AMP-dependent phosphodiesterase activity.


Ovarian HCG-binding in hemicastrated immature female rats.

Hemigonadectomy in 9-day-old female rats results in a drastic increase in the weight and the number of HCG-binding sites of the remaining ovary during further development. However, on a per mg basis of ovarian weight, the number of HCG-receptors is identical in hemicastrated and control rats.


A newly designed decantation for purified synaptic vesicle.

A new decanting device of fine stainless steel needles has been developed, which can remove a layer from a gradient with little contamination from the adjacent upper or lower layers. This new apparatus can be used for removal of a very narrow band from a density gradient and has been successfully used in the fractionation of synaptic vesicles from brain homogenates.


Use-effectiveness and analysis of satisfaction levels with the Billings Ovulation Method: two-year pilot study.

A 2-year study of 135 women using the Billings Ovulation Method as their method of family planning is reported. There were 1381 exposure cycles during the 1st year and 580 during the 2nd year. The total conception rates were 1.303 for the 1st year and 1.896 for the 2nd year. If one subtract the user failures from these rates, the biologic failure rates are 0.072 for the 1st year and 0.517 for the 2nd year. The continuation rate is 51.8%. An analysis of satisfaction levels is presented with a discussion of possible underlying emotional factors.


The diagnosis and therapy of luteal phase deficiency.

Between 1973 and 1975, 16 patients evaluated for infertility at Duke University Medical Center were diagnosed as having luteal phase deficiency. A majority had had prior infertility surveys, and the average duration of their infertility exceeded 2 years. The diagnosis was suspected after study of basal body temperature charts and menstrual patterns in more than 80% of the patients. This diagnosis was established by timed endometrial biopsy. The primary method of therapy was supplementation of the luteal phase with progesterone vaginal suppositories. The pregnancy rate after therapy was 50% and pregnancy occurred after a mean of five treatment cycles. The minimal follow-up of patients who failed to conceive was 8 months. To date, the majority of these pregnancies have been completed without complication and the remainder are progressing satisfactorily. Two additional patients developed luteal phase deficiency while taking clomiphene citrate and became pregnant with progesterone supplementation.


Vaginal absorption of estrone and 17beta-estradiol.

In order to study estrogen absorption from the vagina, 0.5 mg of unconjugated estrone (E1) or 17beta-estradiol (E2) was administered vaginally to 10 postmenopausal patients. A 29-fold increase in plasma E2 and a 4-fold increase in plasma E1 concentrations were observed 1 hour following the vaginal deposition of 0.5 mg of E2. Maximal decreases of 25% and 37% in plasma levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), respectively, were observed at 5 hours following treatment. One hour after vaginal administration of 0.5 mg of E1, a 24-fold increase in plasma E1 and a 3.7-fold increase in E2 were observed. These increases were associated with a 30% decrease in plasma FSH and LH. These data indicate that the vaginal administration of E2 or E1 may be used to achieve physiologic blood levels of these estrogens. They further suggest that vaginal estrogens not be used in patients in whom systemic estrogen therapy is contraindicated.


Pituitary function in adult males receiving medroxyprogesterone acetate.

The pituitary, adrenal, and gonadal functions of nine males (six XY, two XYY, and one XY/XYY) were studied after at least 6 months of medroxyprogesterone acetate (MPA) therapy for antisocial or sex-offending behavior. Five were studied both before and during therapy, four only during therapy. MPA was effective in decreasing serum gonadotropin and plasma testosterone concentrations. MPA caused no change in the 24-hour rhythm or total integrated concentration of growth hormone. The plasma cortisol circadian rhythm was suppressed but not obliterated by MPA therapy. Although a significant decrease (P less than 0.001) in 24-hour integrated concentrations of plasma cortisol was also found, the rise in the plasma cortisol level after insulin-induced hypoglycemia was unchanged.


Spermatozoal antibodies in human seminal plasma as a cause of failed artificial donor insemination.

Seven couples who were in a program of artificial donor insemination (AID) which had not resulted in a pregnancy were advised to abstain from sexual intercourse for 2 days prior to AID. Six of the wives became pregnant following this advice. Seminal plasmas from the seven husbands showed evidence of spermatozoal antibodies. They agglutinated or immobilized healthy spermatozoa and contained immunoglobulin A and complements C-3 and C-4. Immunoglubulin G levels in these seminal plasmas were slightly elevated. Blood sera from the same husbands also agglutinated normal spermatozoa or decreased their motility. A comparison of 33 women who were not advised concerning sexual intercourse prior to AID and 17 women who were advised revealed that 46% of the former group became pregnant, whereas in the advised group 88% achieved pregnancy. The conclusion is that abnormal semen may contain spermatozoal antibodies which adversely affect normal spermatozoa. In order to avoid the presence of spermatozoal antibodies on the wife's cervix, couples are advised to abstain from sexual intercourse, or to use a condom, for 2 days prior to AID.


Vas occlusion by tantalum clips and its comparison with conventional vasectomy in man: reliability, reversibility, and complications.

Occlusion of the vas deferens has been carried out by applying tantalum clips in 60 men. Another 50 men were vasectomized conventionally and served as controls. Vasography showed that two clips were required on each vas to bring about perfect and firm occlusion. The incidence of postoperative infection and other complications was much lower in the clip-occluded cases. Under a long-term follow-up, 10% of the conventionally vasectomized men were dissatisfied with the operation as compared with 2% of the clip-occluded group. Both groups became azoospermic within 3 months and the failure rate was zero. Removal of the clips not only was difficult but left the vas compressed and leaking. The method cannot, therefore, be considered reversible by itself. However, recanalization could easily be achieved by end-to-end anastomosis after excision of the small clipped segment or by side-to-side anastomosis without any excision. This, damage to the neuromuscular apparatus of the vas may be minimized. Male sterilization by clip occlusion has the advantages of minimal surgical intervention, shorter operative time, safety from postoperative infection, and easier recanalization if desired.


Fertility following microsurgical removal of the ampullary-isthmic junction in rabbits.

The role of the ampullary-isthmic junction (AIJ) in fertility was investigated in the rabbit by using microsurgical tuboplastic techniques. Microsurgical transection or resection of the AIJ failed to alter fertility significantly. Nine of ten rabbits which underwent unilateral transection of the AIJ became pregnant on the operated side and eight of the ten became pregnant on the unoperated control side. Of the ten rabbits which underwent unilateral AIJ resection, all became pregnant bilaterally. The results of this study indicate that the AIJ is not necessary for normal fertility in the rabbit.


Effects of testosterone and dihydrotestosterone on spermatogenesis, rete testis fluid, and peripheral androgen levels in hypophysectomized rats.

To compare the effects of testosterone (T) and dihydrotestosterone (DHT) on the maintenance and the restoration of spermatogenesis, hypophysectomized (APX) rats were treated daily for 35 days with 0.5 mg of T propionate (TP) or DHT propionate (DHTP) beginning 5 or 33 days after hypophysectomy. In the maintenance experiment, the weights of the testes and the number of early spermatids were significantly lower in DHTP-than in TP-treated animals, while late spermatids were present only in rats treated with TP. In the restoration experiment, TP increased testicular weight and the number of germinal cells, whereas DHTP had very little effect on the testis. In an attempt to explain these findings, we measured androgen levels in the rete testis fluid (RTF) and peripheral plasma of APX rats treated with TP or DHTP. The concentration of T in the RTF of TP-treated rats was nearly 3-fold higher than the level of DHT in the RTF of animals given DHTP. Plasma T levels measured 1/2, 2, 4, and 24 hours after the last of three daily injections of TP were considerably higher than were the corresponding plasma DHT levels in animals given DHTP. In animals treated with free steroids, peripheral androgen levels between 1/2 and 4 hours after the last injection were much higher in rats given T than in those given DHT, but thereafter this difference disappeared. We conclude that the difference in the ability of subcutaneously injected TP and DHTP to maintain and to restore spermatogenesis in APX rats was due to a difference in androgen levels in the testes of these animals.


Infertility as a consequence of bilateral herniorrhaphies.

The involvement of internal genitalia in inguinal hernias occurring in female infants and children has been reported. We present here an interesting infertility problem as a consequence of accidental "tubal ligation* secondary to bilateral inguinal herniorrhaphies during childhood. Several postulated etiologic factors in the development of such hernias are presented, and the potential occurrence of similar problems in other individuals is emphasized. We urge very meticulous technique when such hernias are repaired, and we reiterate the importance of a thorough medical history during infertility investigation. The potential frequency of this uncommon but devastating problem presenting in an infertility investigation may be underestimated. Additionally, it is conceivable that, with the increasing survival rates of prematurely born infants who are at increased risk for such hernias, this problem may become more frequent.


Self-checking the intrauterine device.

The self-examination habits of 155 women wearing an intrauterine device have been analyzed. One-third were persistently unable to find the tail. There was a loose relationship between the type of device, the length of the tail, and failure to detect. The more parous and those of higher social class were more adept at detection, as were those who examined themselves each month.


The kinetics of 1,2-3H-cortisol after intra-amniotic administration.

Foetuses of random-bred H mice (Velax) received on day 13 of foetal development 1,2-3H-cortisol by the intra-amniotic administration, and 10, 20, 30, 60 and 120 min. after drug injection the radioactivity in the amniotic fluid, foetuses and placentae was determined by methanol extraction. The mean value of total radioactivity in the foetuses and placentae attained 2.2% and 2.7%, respectively, of the injected dose during the first 10 min. and did no longer change substantially. Total radioactivity in the amniotic fluid, after an initial acute fall, corresponded to 16.4% of injected dose from 20 min. to 2 hours after drug administration.


The dynamics of changes in serum lipids during continuous irradiation of rats.

The dynamics of changes in serum lipids (free fatty acids, free glycerol, triglycerides, total cholesterol, and phospholipids) were studied in male Wistar rats irradiated in an open experimental field with a daily dose of 15.48 mC.kg.--1 (60 R) up to a total exposure of 774.0 mC. kg.--1 (3,000 R). The resulting changes occurred in several periods. Initial period of 0--7 days included a drop in triglyceride level and a rise in free glycerol, total cholesterol, and phospholipids in both control and irradiated rats. The period of 14--25 days marked the appearance of serum hyperlipaemia. Between 25--50 days, the levels of the different fractions oscillated and existing changes became more pronounced. The general level of serum lipids during continuous gamma-irradiation exceeded that found in controls. Changes in control animals from experimental field reflected the influence of a changed environment. The modifying factor affecting both irradiated and control rats was night fasting prior to sacrificing the animals and, probably, also the presence of an infradian rhythm in some serum lipid fractions.


Comparison of hydroxyurea and excess thymidine as synchronizing agents in cultures of L5178Y mouse lymphoma cells.

Comparison of double hydroxyurea and hydroxyurea-excess thymidine blockades as synchronizing procedures in cultured L5178Y cells revealed that hydroxyurea mimics the effect of thymidine as regards the degree of the resulting synchrony evaluated by the mitotic index and 3H-thymidine incorporating activity. However, the peaks of the mitotic and 3H-incorporating activity appear later after thymidine than after hydroxyurea blockade and the initial maximum incorporation of 3H-deoxycytidine into DNA was about twice higher in thymidine- than in hydroxyurea-treated cells. On the other hand, the timing of 14C-formate incorporation into purine DNA bases was closely similar in both cell populations.


The spontaneous release of 51Cr from labeled EL-4 ascitic lymphoma cells as dependent upon the composition of the cell population.

Investigations on the spontaneous release of 51Cr from the EL-4 ascitic lymphoma showed that daily rhythmic changes can be correlated with the dominance of certain cell types in the population. A generation time of 9.8 h, an average doubling time of 32 h, and an 'appearance cycle' of 96 h were established for the population. Earlier observed variations in the values for spontaneous 51Cr release can be explained in terms of the cellular composition of the population.


The effect of propranolol upon chick embryo cardiogenesis.

The teratogenic effects of propranolol HCl on cardiac development were studied in chick embryos of days 3 and 4 of incubation. Propranolol was injected into the yolk sac at doses ranging from 0.05 to 0.6 mg per egg. All the treated and control embryos were examined on day 7. The LD50 for the embryos treated on the 3rd and 4th day was 0.15 and 0.35 mg per embryo, respectively. Cardiac anomalies such as aortic stenosis ventricular septal defects and common truncus arteriosus were observed. Other malformations included atrial septal defects, thin atrial wall and defects of the pulmonic, aortic and atrioventricular valves. The incidence of cardiac anomalies in the controls was very low. Propranolol was observed to slow the heart rate in the experimental embryos. It is suggested that slowing of heart rate at the early stages of heart development caused aberrant bloodstream flow patterns which probably resulted in the genesis of cardiac anomalies. The results of this study indicate that propranolol has teratogenic effects on chick embryo cardiogenesis.


The marfan's syndrome. In vitro study of collagen metabolism in tissue specimens of the aorta.

Tissue specimen of the aorta was obtained from a patient with Marfan's syndrome after heart surgery. Media and adventitia were carefully separated and subsequently used for biochemical characterization. Aortas from an embryonic calf and from a human adult were used as internal controls. The data clearly indicated that an insufficient synthesis of type I collagen rather than a defect in the formation of cross-links may be the prime cause in this inherited connective tissue disorder. Such a disturbance in the regulation of the genes coding for the different collagen chains may explain the weakness and enhanced extensibility of the blood vessels finally resulting in an aneurysm.


Brittle diabetes in pregnancy.

In eight brittle diabetics the insulin requirement increased during successful pregnancies from 35 to 64 U./day (in 29 stable severe diabetics from 53 to 78 U./day). The within-day glycemic excursions were calculated as the mean of the three differences between four time points: fasting, one hour after breakfast, two hours after breakfast, and two hours after lunch. This parameter was constant throughout the pregnancy in nondiabetics (34-46 mg./100 ml.) and stable severe diabetics (55-72 mg./100 ml.). In brittle diabetics it dropped from 147 mg./100 ml. before the pregnancy and 153 mg./ 100 ml. at eight weeks to 85 mg./100 ml. at 36 weeks. The between-day variability was calculated as the mean glycemic difference between two successive days at the four points of time noted above. It was very low in nondiabetics (49-53 mg./100 ml.). In brittle diabetics it decreased from 127 mg./100 ml. before pregnancy and 120 mg./100 ml. at eight weeks to 46-55 mg./100 ml. at 24-36 weeks. This shows that brittleness substantially decreased in the second half of pregnancy.


On the mechanism of diazoxide-induced hyperglycemia.

Infusion of diazoxide (16.5 mg./kg. in 10 minutes) into normal unanesthetized dogs resulted in a prompt hyperglycemia due to increased hepatic glucose production as measured with a 3-3H-glucose primer-infusion technique. Plasma insulin and glucagon were decreased. Glucose uptake failed to increase. Diazoxide administration during period of alpha adrenergic receptor blockade with phentolamine still caused hyperglycemia and increased glucose production. Glucose uptake was inhibited despite adequate plasma insulin. Infusion of somatostatin along with insulin prevented the effects of diazoxide on plasma glucose and glucose production. It is concluded that diazoxide hyperglycemia is not due solely to decreased insulin secretion or increased epinephrine secretion and that glucagon is not a contributory factor. Diazoxide may act directly to increase glucose production and inhibit glucose uptake. Somatostatin appears capable of blocking the effect of diazoxide on glucose production by an unknown mechanism.


Pregnancy in diabetes complicated by vascular disease.

Over 50 years of experience with pregnancy in diabetic women is reviewed. In particular, the maternal and fetal survival in mothers with either microvascular or macrovascular disease is considered. This includes White classes E, F, R, RF, H, and T. In this group of patients with vascular disease, maternal survival during pregnancy is virtually 100 per cent with the exception of class H (ischemic heart disease). Fetal survival has steadily improved throughout the time period examined, but is still considerably below that of pregnancies occurring in women without vascular disease. Long-term maternal survival is adversely affected by the first decade after delivery.


The regulation of plasma ketone body concentration by counterregulatory hormones in man.

Previous studies have attributed norepinephrine's ketogenic activity to its ability to mobilize peripheral fat stores. This study was designed to determine whether norepinephrine has ketogenic activity independent of its lipolytic effect in diabetic man. Six insulin-dependent diabetic subjects were infused with pathophysiologic concentrations of norepinephrine (0.08 microgram./kg./min.). As a control for norepinephrine's lipolytic effect, a separate heparin-induced free fatty acid generation study was performed on each subject. The results demonstrate, for the first time in man, that norepinephrine has ketogenic activity independent of its lipolytic effect. Furthermore, physiologic elevations of norepinephrine concentration were also demonstrated to increase plasma glucagon concentration. Our data are consistent with the possibility that the rise in concentration of glucagon may have a participated in the catecholamine-augmented ketogenesis.


Histocompatibility antigens and diabetic retinopathy.

Of 160 patients with onset of diabetes at or after 30 years of age, the 84 with no evidence prevalences of HLA-A1 and B8 when compared with the 76 with retinal complications or with the 282 healthy blood donors. In addition, in 90 patients with onset of diabetes before age 30 years, we could confirm the reported significant increase of HLA-B8 and decrease of B7, but no differences were noted between those juvenile-onset diabetics with and those without retinopathy.


The effect of hGH deficiency on the insulin response to glucagon after oral glucose loading.

Six children and adolescents (aged from 2 6/12 to 16 years) with isolated hGH deficiency were subjected to a standard oral glucose tolerance test (OGTT) followed by the administration of IV glucagon at 180 mins. Three of them underwent a second test after several months of hGH therapy. Nine patients underwent a separate IV glucagon test and two of these patients had both tests. As controls served 14 endocrinologically normal children and adolescents, who underwent both tests. It was found that the patients with isolated hGH deficiency had lower basal insulin and blood glucose levels and that their insulin response to IV glucagon even after oral glucose preloading was significantly lower than in the control group. This response was partially restored by several months of hGH treatment in the three patients tested. These findings are interpreted as further evidence for an insulinotrophic effect of hGH.


Development of insulin resistance in normal dogs following alloxan-induced insulin deficiency.

Insulin resistance was measured in 16 normal dogs by a method involving the continuous intravenous infusion of epinephrine, propranolol, glucose and insulin. With this approach, endogenous insulin secretin is inhibited, similar steady state levels of exogenous insulin are achieved in all doags, and the resultant steady state plasma glucose level provides a direct estimate of the ability of insulin to dispose of the infused glucose load. Thus, the higher the steady state plasma glucose level, the more the insulin resistance. Different amounts of alloxan were then administered to these dogs in order to produce insulin deficiency of varying degrees. Insulin resistance was then measured again in each dog. The results indicated that insulin resistance did not develop in dogs with only a moderate degree of insulin deficiency (fasting plasma glucose levels less than 150 mg/100 ml). On the other hand, a significant degree of insulin resistance developed in dogs with severe insulin deficiency (fasting plasma glucose greater than 150 mg/100 ml). Furthermore, the insulin resistance that developed in dogs with severe insulin deficiency could be returned to normal with insulin replacement for one week. These results indicate that insulin resistance can occur as a secondary manifestation of insulin deficiency.


Serum free insulin concentrations during the treatment of diabetic coma and precoma with low dose intramuscular insulin.

Fifty patients in diabetic coma or precoma, 33 of whom had previously received insulin and had circulating insulin antibodies, were studied during treatment with a low-dose intramuscular insulin regime. In the presence of insulin antibodies, serum free insulin was separated from bound insulin by steady-state gel filtration. The initial mean serum free insulin concentration in the group of patients without insulin antibodies was 9 mU/1, 1 to 2 hours after intramuscular therapy it had risen to 22 mU/1, and after 7 to 8 hours to 73 mU/1. The corresponding concentrations for the group with insulin antibodies were 13, 23 and 74 mU/1. No relationship was found between the concentrations of serum free insulin attained and the age of the patients, their initial degree of acidosis, dehydration, and systolic blood pressure, the insulin antibody characteristics of their sera, nor the rate of decline of the blood glucose.


The effect of intraportal and peripheral infusions of glucagon on insulin and glucose concentrations and glucose tolerance in normal man.

The effect of peripheral and intraportal infusions on 0.86 pmol/kg-min-1 of glucagon on plasma glucose, plasma insulin, and glucose tolerance was examined in four normal subjects. Peripheral glucagon concentrations increased by 60--90 pmol/1 during intraportal and 70--180 pmol/1 during peripheral infusions. The infusions caused increases in plasma glucose levels of approximately 1 mmol/1, and in plasma insulin levels of 75--100%, regardless of route of administration. Intravenous glucose tolerance tests carried out during the glucagon infusions showed that glucose tolerance remained within the normal range and was uninfluenced by the route of administration.


The effect of cigarette smoking on blood sugar, serum insulin and non esterified fatty acids in diabetic and non diabetic subjects.

The effect of cigarette smoking on carbohydrate metabolism has been investigated in 10 diabetic and 18 non-diabetic subjects. All were habitual smokers. Neither the fasting plasma sugar nor the plasma sugar response to an oral glucose load was significantly altered by smoking. Serum insulin, free fatty acids, cholesterol and triglyceride were measured in 10 non-diabetic patients, and were not significantly altered by smoking. It is concluded that in habitual smokers at least, cigarette smoking does not impair carbohydrate metabolism. In addition, it seems that smoking before or during oral glucose tolerance test is unlikely to influence the diagnostic value of the test.


Plasma glucagon suppression by phenformin in man.

In an attempt to elucidate the mechanism of action of phenformin, eleven juvenile-onset, insulin-requiring diabetic subjects underwent four different treatment regimens during standard breakfast tests. These four treatments were: control (no insulin or phenformin); insulin alone (15 U regular insulin administered subcutaneously one-half hour before breakfast); phenformin alone (50 mg of the timed-release capsule given twice daily for three days before the study and two and one-half hours before breakfast on the day of study); and phenformin plus insulin (in the amounts and at the times stated above). Phenformin was found to decrease postprandial hyperglycaemia significantly when compared with control values, and its addition to insulin further decreased the postprandial glucose rise below that found with insulin alone (p less than 0.005). These effects were associated with a reduction in early (30-min) postprandial hyperglucagonaemia (p less than 0.05). Triglyceride levels, gastrin secretion, growth hormone levels, and increments of alpha-amino nitrogen were not affected by phenformin. Thls, suppression of postprandial hyperglucagonaemia may be an additional mechanism in the reduction of postprandial hyperglycaemia after phenformin.


Glucagon secretion in diabetic patients with idiopathic haemochromatosis.

The aim of the present investigation was to determine in patients with idiopathic haemochromatosis whether diabetes is of the primary type or secondary to pancreatic injury due to iron deposition. For this purpose, plasma glucagon concentrations were determined following arginine infusion or an oral glucose load in eight patients with diabetes and idiopathic haemochromatosis. The enhanced glucagon response to arginine and the nonsuppressibility of glucagon secretion by oral glucose found in these patients were similar to the results found in the same tests performed in our previous series of patients with "idiopathic" diabetes and at variance with those reported by others in patients with chronic pancreatitis.


Enzyme activities in quadriceps femoris muscle of obese diabetic male patients.

In biopsy samples of the lateral part of the quadriceps femoris muscle of 6 obese diabetic male patients and of 11 obese males with a normal glucose tolerance, the activities of 7 enzymes of energy metabolism were estimated: hexokinase, cytoplasmic glycerol-3-phosphate: NAD dehydrogenase, triosephosphate dehydrogenase, lactate dehydrogenase, citrate synthase, malate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase. The obese diabetic male patients exhibited decreased activities of enzymes of carbohydrate breakdown and cytoplasmic NAD regeneration. Enzymes connected functionally with aerobic metabolism were less affected. The unchanged activity of 3-hydroxyacyl-CoA dehydrogenase points to an increased role of fatty acid catabolism in the muscle.