The treatment of some fractures of the forelimb in the horse.

Sir Frederick Hobday's service as a Veterinary Officer in the Army Veterinary Corps during the Great War 1914-1918 is recorded. This is followed by a description of the fractures of the distal forelimb which can be treated satisfactorily by surgery, and includes fractures of the carpal, the small metacarpal, the proximal sesamoid bones, the first phalanx and the extensor process of the third phalanx.


Elongation factor T from Bacillus stearothermophilus and Escherichia coli. Purification and some properties of EF-Tu and EF-Ts from Bacillus stearothermophilus.

Homogeneous preparations of elongation factors EF-Tu and EF-Ts from Bacillus stearothermophilus have been obtained with specific activities of 20000 +/- 2000 and 500000 +/- 50000 units/mg, respectively. By dodecylsulphate-polyacrylamide gel electrophoresis the molecular weight of EF-Tu was found to be 49000 +/- 2000 and of EF-Ts 35500 +/- 1000. Nucleotide-free EF-Tu was prepared by using ITP as a GDP-binding-site-directed analogue. EF-Tu was shown to contain two sulphydryl groups, one reacting fast and one slowly with N-ethylmaleimide and 5,5'-dithio-bis(2-nitrobenzoic acid) under non-denaturing conditions. The same reagents were shown to react with the three sulphydryl groups of EF-Ts in the native state. The heat stabilities of EF-Tu and EF-Ts are reversed with respect to the Escherichia coli factors, EF-Tu being the more stable protein; even nucleotide-free EF-Tu is relatively stable with a half-life at room temperature of about 35 h.


The linkage of lysine in the O-specific chains of Proteus mirabilis 1959.

Lipopolysaccharides of qualitatively identical but quantitatively different sugar composition were extracted from Proteus mirabilis strain 1959. The lipopolysaccharide with the higher percentage of typical O-specific constituents was subjected to partial acid hydrolysis. An oligosaccharide B22 was separated by paper chromatography and electrophoresis. It was found to be composed of equimolar amounts of D-galacturonic acid, D-galactosamine and L-lysine. Dinitrophenylation of the oligosaccharide as well as of the genuine lipopolysaccharide afforded xi-dinitrophenyl-L-lysine after acid hydrolysis, showing that lysine was linked to the disaccharide via its alpha-amino group. Further studies including the Morgan-Elson and Elson-Morgan reactions, NaBH4-reduction, hydrazinolysis and periodate oxidation revealed the structure of oligosaccharide B22 as D-galacturonyl-(1 leads to 4)-D-galactosamine with lysine attached to the carboxylic group of galacturonic acid via its alpha-amino group. Judged from its high inhibition capacity this oligosaccharide has to be considered as an essential part of the serological determinant of Proteus mirabilis 1959. The frequent occurrence of lysine and galacturonic acid in Proteus mirabilis O-serogroups and their possible significance for the respective serological specificities are discussed.


The enzymic addition of poly(A) to the 3'-end of RNA using bacteriophage MS 2 RNA as a model system.

ATP : RNA adenyltransferase, purified from Escherichia coli, was used to add a series of adenosine residues to the 3'-end of MS2RNA. Incubations of the order of a few minutes at 37 degrees C were sufficient for synthesis of a short poly(A) chain that did not appreciably alter the hydrodynamic or electrophoretic properties of MS2 RNA. The size of the poly(A) tails was estimated by gel electrophoresis after prior hydrolysis of the primer RNA with pancreatic ribonuclease. These results were in good agreement with the values calculated on the basis of the relative amount of incorporated AMP. After the addition of a short poly(A) tail, approximately 50% of the treated material binds specifically to an oligo(dT)-cellulose column. The majority of the recovered poly(a)-containing RNA was still intact, as shown by analysis on polyacrylamide gel. After incubations beyond 6 min, slowly sedimenting material, also showing reduced electrophoretic mobility, was formed. Presumably this material corresponds to RNA chains to which long poly(A) tails are linked.


A computerized neurosurgical intensive care system.

A specialized neurosurgical data acquisition and processing system was developed and applied in practice to monitor some 60 patients after head injury or neurosurgical operations. At first the system allowed off-line operation, and the experiences thus gained made it possible to implement the system in its present form for real-time on-line patient monitoring. The algorithms prepared in our laboratory allow rapid and concise presentation of results and have proved their usefulness in clinical practice. The main parameters of interest in neurosurgery are intracranial pressure (ICP) and the volume of cerebrospinal fluid (CSF) drained from one of the lateral ventricles. Examples of statistical analysis of both these variables, and their presentation in the form of tables, diagrams and histograms are given.


Multivariate data analysis based on a computerized patient monitoring system.

Multivariate time series data in post-operative patients (respiratory and cardiovascular) are compared to reference groups. Using this technique under the program control of a computerized patient monitoring system (IBM 1800) various classes in the respiratory and cardiovascular spectrum can define the co-ordinate system in hyperspace. The patient in crisis is recognised by his deviation from normal rates of change of the variable set, as well as by the time trajectories of recovery in the hyperspace.


Insulin and glucagon secretion by pancreatic islets from nondiabetic and diabetic sand rats (Psammomys obesus).

The secretion of insulin and glucagon was investigated in pancreatic islets from diabetic and nondiabetic sand rats of similar age and weight. The metabolic characterization was based on an intraperitoneal glucose tolerance test. Compared to nondiabetic animals diabetic sand rats had a diminished insulin content in their islets and a decreased insulin secretory response to glucose, glyceraldehyde and theophylline. Diazoxide inhibited insulin release in diabetic as well as in nondiabetic sand rats whereas mannoheptulose was effective only in the nondiabetic rats. There was no significant difference in glucagon content between the two groups. The glucagon secretion by pancreatic islets of diabetic animals was not suppressed by glucose, as in nondiabetic sand rats islets, but by glyceraldehyde. This indicates that the sensitivity to glucose rather than the suppressibility of glucagon release was altered.


Some adrenomimetic drugs affecting lipolysis in human adipose tissue in vitro.

In human adipose tissue in vitro, dose-response curves were followed for different adrenomimetics releasing free fatty acids and glycerol into an albumin-containing medium. Phenylephrine, salbutamol and t-butyl-norsynephrine produced lipolytic actions whose maximum did not exceed 20% of the maximal isoproterenol lipolysis. Phentolamine (1 x 10(-5) M) did not potentiate the effect of any of these drugs. When using salbutamol or t-butyl-norsynephrine for antagonizing isoproterenol actions, typical antagonism was found. The parallel shift of the isoproterenol curves showed pA2 values 5.8 for salbutamol and 5.7 for t-butyl-norsynephrine. Comparison of human and rat adipose tissue reactivity shows identical affinities of the drugs studied in both tissues, but related to isoproterenol, diminished intrinsic activities of salbutamol and t-butyl-norsynephrine in human adipose tissue.


Histological alterations in spleen and bone marrow colonies produced by irradiation of the donor mice.

The previously reported decrease in the ratio of erythrocytic (E): granulocytic (G) spleen colonies observed 8 days after bone marrow transplantation, when the donors had been x-irradiated up to 4 hours before the marrow was taken for transfer, was confirmed. The effect of taking the marrow between 4 hours and 13 days after x-irradiation, on the E:G ratio in both spleen and femoral bone marrow colonies, has been studied in detail. The reversion to a normal E:G ratio in spleen colonies assessed at 8 or 10 days was associated with increases in this ratio of colonies in the femoral bone marrow. Transplantation of cell suspensions prepared from the spleen and femoral bone marrow of primary recipients 8 days after the initial transfer produced a histological distribution of 8-day colonies in secondary recipients which was indpendent of x-irradiation of the donor. The data suggest that a hypothesis involving CFU migration within the spleen and, possibly, from the bone marrow to the spleen, provides a more satisfactory explanation of the data than one involving two CFU populations with different radiosensitivities.


A possibility to achieve genetic transformation in the platyfish-swordtail system (Platypoecilus maculatus - Xiphophorus helleri).

In order to determine how informative homologous donor DNA might be made available to propigment cells of the recipient Xiphophorus helleri for transformation, labelled heterologous DNA from E. coli was injected into the neural crest region or the yolk sac of embryos of the recipient. On the basis of the degradation rate of the donor DNA and the incorporation rate of radioactivity into the recipient DNA, it is concluded that injection into the neural crest region may be a suitable method to make available informative homologous donor DNA for transformation.


The Stein-Leventhal syndrome: a neuropituitary disorder.

Hypothalamic and pituitary gonadotropin function and responsiveness in four patients with well-documented Stein-Leventhal syndrome were studied. All patients were of reproductive age and had had menstrual disorders since menarche. Estrogen production was assessed by measuring the circulating levels of immunoreactive estradiol, by vaginal smears, and by the progestogen-induced menses test. Gonadotropin function was evaluated by measuring the serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in blood samples obtained at 15-minute intervals for 150 minutes. Pituitary gonadotropin reserve and responsiveness were studied by giving an intravenous bolus of synthetic LH-releasing hormone (LH-RH) and measuring the circulating gonadotropin levels before and after the injection.


Serum estradiol response to gonadotropin-releasing hormone: studies in normal women and in women with secondary amenorrhea.

Serum estradiol (E2), luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels were measured in blood samples obtained prior to and at frequent intervals for 360 or 480 minutes following the subcutaneous administration of gonadotropin releasing hormone (Gn-RH) to eight normal women and nine patients with hypothalamic secondary amenorrhea. In the normal subjects given 100 mug of Gn-RH on day 7 of the menstrual cycle, there was no significant increase in the mean E2 concentration above basal levels. Six women with secondary amenorrhea received Gn-RH, 100 mug, for 4 successive days; frequent blood samples were obtained on days 1 and 4. On day 1, the mean E2 concentration at 360 minutes was significantly greater than the mean basal level. On day 4 no significant increase in E2 was detected, although the mean LH and FSH responses and basal E2 level were not different from those of day 1. Four women with secondary amenorrhea received daily doses of 500 mug of Gn-RH for 7 days. Significant increases in mean serum E2 concentration (100 to 150 pg/ml) were noted at 6 and 8 hours after administration on day 1 and at 8 hours on day 4. No significant rise in E2 was detected on day 7. The mean LH and FSH responses did not differ from those observed in women who received the 100-mug dose, and there were no significant differences in responses on successive days of Gn-RH administration.


Effect of prostaglandins, nitrofurantoin, and Escherichia coli on response of human vas deferens to norepinephrine.

Surgical specimens of human vas deferens, mounted isometrically in vitro, were tested for their reactivity to norepinephrine, the major neurohumoral control mechanism in this tissue, under a variety of conditions. There was no significant difference in reactivity (measured as amplitude and frequency of contraction) between vasa obtained under either spinal or local anesthesia. Similarly, the age of the donor (range, 20 to 79 years) had no effect on either measure of reactivity. Prostaglandins A1 (10(-7) gm/ml) and E2 (10(-9) gm/ml), Escherichia coli (10(5) organisms/ml), and E. coli endotoxin (10(-7) gm/ml) did not affect norepinephrine responses, suggesting that the role of these compounds in problems of fertility is not related to an alternation in sperm transport through the vas. Nitrofurantoin (10(-5) gm/ml) also had no effect on reactivity to norepinephrine, providing further evidence that low sperm counts in patients taking this drug are more appropriately attributed to a direct effect on spermatogenesis than to an effect on sperm transport.


[Studies on the measurements of LH-releasing hormone (LH-RH) by radioimmunoassay (RIA) (author's transl)].

The radioimmunoassay for LH-RH would aid greatly in the assessment of hypothalamic function. The anti-LH-RH was prepared by immunizing rabbits with LH-RH conjugate of BSA. 125I-LH-RH was prepared by the lactoperoxidase method and Sephadex G-10 column chromatography. The double antibody RIA technique was employed. On the assay of biological materials, LH-RH was extracted by methanol because LH-RH was rapidly destroyed in the serum, and this breakdown could not be prevented by benzamidine or 2,3-dimercaptopropranol. Sensitivity of this RIA system ranged from 10 tp 104 pg/ml, and the coefficient of variations of intra- and interassay were 12.9% and 9.% respectively. The serum LH-RH levels of men in a normal gonad state were below 10 pg/ml, and those of women in a normal gonad state in the early follicular or luteal phase were below 50 pg/ml. Whereas those of postmenopausal or castrated women were increased, and were highest in women with several gonadal disturbed states. The disappearance curve of LH-RH in women was characterized by two exponentials, t(1/2) of the initial component was 4.9 min, and that of the second component 24.6 min. Urinary excretion of exogenously administered LH-RH was also studied.


[Effects of synthetic sex steroids on the pituitary responsiveness to luteinizing hormone releasing hormone (LH-RH) (author's transl)].

Effects of short and long term administrations of an oral contraceptive preparation on the pituitary responses to the synthetic LH-RH were compared in the present experiment. Five normal cycling women were used as controls in the late proliferative phase. Five healty volunteers taking an oral contraceptive agent (1.0 mg norethindrone with 0.05 mg mestranol) for less than 10 cycles were served as short term group and other 4 women taking the same preparation for more than 40 cycles were studied as long term group. Volunteers in each group were kept fasting overnight and 5 ml of blood was drawn at 9 to 10 am on the day of experiment. Ten minutes after drawing blood, 200 mug synthetic LH-RH was injected subcutaneously in the late proliferative phase in the normal cycling women. According to the same procedure, women taking pills were administered LH-RH on the 7th to 12th day after the beginning of taking the first tablet in each cyle. Three ml of blood was taken at 15, 30, 60, 120 minutes and 24 hours, and serum LH and Fsh were determined by the double antibody radioimmunoassay. The 2nd IRP-HMG was used as the standard materials and expressed as mIU/ml of serum. Mean baseline serum LH and FSH concentrations were not suppressed in a short term administration of norethindrone-mestranol combination. Fifteen minutes after the subcutaneous injection of LH-RH, mean LH level was significantly elevated, and thereafter the level was not significantly changed as compared with that seen in the late proliferative phase of the cycle. Concerning the FSH response to LH-RH, a short term administration did not induce a significant rise. ...


Family sizes of children and family sizes of women.

This paper demonstrates the relation that obtains between the average family size of women and the average family size of offspring of those women. It estimates the value of these two measures for cohorts of American women aged 45-49 in various years from 1890 to 1970. It shows that children born during the post-war baby boom actually derived from smaller families than those born during the low-fertility 1930's; that under current patterns a woman would have to bear an average of almost two children fewer than were borne by her mother merely to keep population fertility rates constant from generation to generation; and that average family size for nonwhite children exceeds that for white by 50 percent, although the racial difference in family sizes of women is only 19 percent.


The United States population by race and urban-rural residence 1790-1860: reference tables.

The U.S. population by race and urban-rural residence from 1790 to 1860 is presented. The definition of the urban population used is that population residing in incorporated places of 2,500 population or more. The rural population is the residual of the total population minus the urban population, as defined above. The tables provide previously unavailable data on the urban-rural distribution of the black and white populations 1790-1860 and are compatible with data for the total population published by the Census Bureau.


The conservative restoration of class IV and VI defects.

Success in conservatively restoring Class IV and VI defects depends upon the method of retention and the restorative material chosen to best fulfill the clinical need. This need is determined by the size of the defect and its location in the arch relative to the functional load, age, vanity, and general dental appreciation of the patient.


Clinical evaluation of anterior restorative materials.

There are many materials (metallic and tooth-colored) which can be used to restore lost tooth structure and defects of anterior teeth. Protection of the pulp and periodontium are important considerations in restoring form, function, and smile. None of the present restorative materials is ideal in every respect. By knowing the properties of each material, alterations can be made in the cavity preparation, insertion of materials, and finishing procedures to overcome many weaknesses and enhance the strong qualities. The finest material will fail unless every procedure is carefully planned and executed. Patient cooperation is essential in respect to diet, hygiene, and maintenance recalls. The right combination of these fundamentals will spell "Happy Dentistry".


Nonprecious metal alloys for fixed restorative dentistry.

Non-noble alloys are available for use in the fabrication of cast restorations. These alloys are not necessarily designed for subsequent application of porcelain. Because they are promoted for use in place of the traditional gold alloys, significant changes in technique and armamentarium are necessary. Casting of acceptable clinical quality can be obtained, but not without additional equipment and personnel training. Obtaining casting of gold alloy quality on a routine basis may not be easily achieved. Casting into detail is possible (see Fig. 5), although greater surface roughness of the casting may be observed with the non-noble alloys. A high polish is possible (Fig. 6), however technicians and clinicians accustomed to and expert in polishing single or multiple gold alloy castings will require time and training to adjust to the somewhat more difficult and time-consuming techniques required in the polishing of non-noble alloys. Well fitting castings of the non-noble alloys require investments capable of greater thermal and/or hygroscopic expansion. The solidification shrinkage in non-noble alloys is greater than that of gold alloys. The clinician may find casting of these alloys to be "tight-fitting" on insertion. At present, because additional time and armamentarioum may be required, laboratory fees for the non-noble metal casting may not be any more economical than those of cast gold alloys. Therefore, the clinician and patient may benefit little with regard to reduced fees for restorations constructed of these alloys. In conclusion, the non-noble metals may find increased use in fixed restorative dentistry as expertise develops to the level at which usage of these products becomes routine. These is still considerable clinical information needed as to the durability and corrosion resistance of these alloys. Some work has been work has been done on the corrosion of these alloys, but much data remains to be obtained. Soldering these alloys is difficult and requires training of the technician in the required usage of special solders. The following facts should be considered in casting and finishing non-noble alloys for single and multiple unit casting in dentistry. 1. Silicate or phosphate bonding investments are required. 2. Recognition of proper casting appearance of the molten alloy is essential. 3. Additional armamentarium is required to obtain casting temperatures necessary. 4. Polishing procedures are more laborious and require harder abrasives. 5...


Early behavioral differences: gender or circumcision?

In human studies, the possible long-term effects on behavior of early physical insult or pharmacological agents have received little attention. We present both circumstantial and direct evidence that circumcision of male infants leads to behavioral changes. In some American studies  using circumcised infants, reported gender differences may instead be the result of the altered behavior of circumcised males. We suggest that circumcision requires more study in its own right,  and that it requires description if not control in all neonatal and infancy studies.


Isotransplantation of organ-cultured neonatal pancreas: reversal of alloxan diabetes in the rat.

Pancreases from neonatal rats four to 16 days postpartum were grown in organ culture for from two to nine days. Approximately 10-20 explants, each measuring 1 mm.3 (1 mg.), were grown on a single Millipore filter placed at the gas-liquid interface of a medium consisting of 50 per cent horse serum and 50 per cent chick embryo extract. Following organ culture, an estimated 9-20 mg. of cultured islet tissue were dissociated with collagenase and isotransplanted into the peritoneal cavity of alloxan-diabetic recipients. In seven of eight recipients the diabetes was reversed between 11 and 53 days of posttransplantation. Animals receiving 12-16 mg. of cultured islet attained normoglycemia in 11-20 days; animals receiving 9-10 mg. of cultured islet tissue recovered between 45 and 53 days. These animals have remained symptom-free for over six months. Biopsies of grafts taken from the peritoneal cavity following reversal of diabetes contained well-vascularized islets compared primarily of heavily granulated beta cells. Quantitative analysis of host pancreases by the linear scanning method (biopsied at one to two weeks and four to five months following reversal of the diabetes) demonstrated that the total beta-cell mass was 3 per cent and the total insulin content was 6 per cent of the normal values. Little or no evidence of regeneration of host beta cells was observed. These studies show that a period of organ culture prior to isotransplantation does not impair the ability of islet tissue to reverse alloxan diabetes in the rat.


Inhibition of insulin rlease by scorpion toxin in rat pancreatic islets.

Toxin purified from venom of the scorpion Leiurus quinquestriatus was used to release the norepinephrine from adrenergic nerve terminals in isolated pancreatic islets perifused in vitro. Addition of toxin (10 mug./ml) to the perifusion medium caused a sixfold increase in release of norepinephrine in the presence or absence of 3 X 10(-5) M phenoxybenzamine. During 20 minutes of stimulation with toxin, the pancreatic islets released an average of 15 pg. of norepinephrine per islet, which represented 20 per cent of the normal content of norepinephrine in islets. Insulin secretory rates in response to either 1.0 or 3.0 mg./ml. glucose were inhibited similarly by scorpion toxin. Addition of phenoxybenzamine abolished the inhibition of insulin release caused by scorpion toxin. Phenoxybenzamine alone did not affect release of insulin. Neither the enhanced release of norepinephrine nor the decreased release of insulin was reversed by a 20-minute wash-out period after infusion of toxin. These results indicate that the sympathetic nerve terminals in the rat pancreatic islet contain considerable amounts of norepinephrine that can be released by scorpion toxin. The norepinephrine released from sympathetic nerve endings in the pancreatic islet can inhibit release of insulin through an alpha-adrenergic action that is blocked by phenoxybenzamine.


Lymphocytes and the gut.

An increasing interest is being shown in the physiopathological relationship between lymphocytes and the intestinal tract. The possible importance of immune phenomena in the aetiology of a wide variety of bowel diseases is one reason for the interest. In this review aspects of the morphology, distribution and recirculation of lymphocytes with particular reference to the gut are discussed. Some tentative conclusions of the significance of alterations in disease are made.


Insulin and the glucose-glucagon feedback mechanism in the duck.

The relationship between insulin and the glucose-glucagon feedback mechanism was studied by testing the effectiveness of various routes, doses and timing of insulin administration prior to and during a glucose tolerance test in Peking ducks made transiently diabetic by subtotal pancreatectomy. Insulin injections or infusions given either before, or only during the glucose load, did not restore the A-cell response to glucose. Yet, if given both before and during the glucose test, in conditions which mimic the physiological basal insulin level and its variations (with, initially, intramuscular injections of 0.2 IU/kg and 8 mug/kg glucagon, every six hours, and then an intravenous injection of 3.6 mU/kg plus an infusion of 0.9 mU/kg/minute for one hour), the normal glucagon response to glucose was re-established. Insulin must therefore be present, both before and during glucose stimulation, for glucose to be effective as an A-cell suppressor.


Search for a biochemical basis of diabetic microangiopathy.

Diabetic microangiopathy, particularly as seen in the renal glomerulus, is characterized by morphological and biochemical alterations of the capillary basement membrane. Observations from a number of disciplines have indicated that the microvascular disease is not a separately inherited entity but a true consequence or "complication" of insulin deficiency. An evaluation of the biochemical events which could be responsible for the basement membrane lesions of diabetes indicates that the hyperglycemia or plasma somatotropin elevation of this disease alone, or in combination, may play an important role.


Effects of intermittent hypoglycaemia in pregnant rats on the functional development of the pancreatic B-cells of their offspring.

Intermittent hypoglycaemia was induced by insulin injections into pregnant rats. At birth, the pups body weight and pancreatic insulin content were slightly but significantly decreased. In contrast, the B-cells of these newborn rats responded more markedly to a glucose challenge than the controls. The pancreases of the insulin injected rats were grearly depleted of insulin, possibly because of feedback inhibition of insulin synthesis by exogenous insulin. This inhibitory effect was restricted to the mother since the injected insulin did not cross the placental barrier. It is proposed that the nutrient supply to the fetus influenced body growth and pancreatic insulin accumulation whereas blood glucose variations, even intermittent hypoglycaemia, promoted precocious maturation of the B-cell glucoreceptor system.


Calcium-antagonists and islet function. IV. Effect of D600.

D600 (2 to 20 muM; alpha-isopropyl-alpha [(N-methyl-N-homoveratril)-gamma-aminopropyl]-3,4,5-trimethoxyphenyl-acetonitril) caused a dose-related, rapid and reversible inhibition of glucose-induced insulin release. It also suppressed the insulinotropic action of a sulphonylurea but failed to affect the enhancing action of theophylline upon glucose-induced release. The inhibitory effect of D600 was enhanced at low extracellular Ca2+ concentration. D600 reduced both basal and glucose-stimulated 45calcium net uptake, whilst failing to affect the efflux of 45calcium from perifused islets. The recognition of glucose by the B-cell was also unaffected by D600 as judged by the effect of the sugar upon both 45calcium efflux and net uptake in the isolated islets. These findings are compatible with the hypothesis that the primary mode of action of D600 is to inhibit Ca2+ entry in the B-cell.


Mutagenicity of 5-nitroacenaphthene in salmonella.

5-Nitroacenaphthene was proved to be mutagenic on TA100 and TA98 of Salmonella typhimurium with or without metabolic activation by S-9 Mix. A possible metabolite, 5-hydroxyacenaphthene, carcinogenicity of which had not been observed, was non-mutagenic on TA100 and TA98, with or without metabolic activation.


The effect of oral and intravenous metoclopramide on human lower esophageal sphincter pressure.

Lower esophageal sphincter (LES) pressure was evaluated in response to oral or intravenous metoclopramide in normal subjects and in patients with symptomatic gastroesophageal reflux. Both the oral and intravenous administration of metoclopramide gave a dose-related increase in LES pressure. Complete dose-response curves to the oral compound showed greater absolute responsiveness in normals as compared to patients with LES incompetence. The generally accepted oral dose of 10.0 mg of metoclopramide gave a slight increase in LES pressure which was not consistent in all symptomatic patients. These studies suggest that higher doses of metoclopramide may be required for treating symptomatic gastroesophageal reflux secondary to LES incompetence.


Immunohistochemical identification of the cholecystokinin cell in the intestinal mucosa.

In indirect immunofluorescence tests, antibodies against pure porcine cholecystokinin (CCK) have detected specific CCK cells in the duodenal and jejunal mucosa of the dog and man. The CCK cells were scattered in the epithelium of the crypts, although some were in the villi. No CCK cells were found in the stomach, pancreas, terminal ileum, or colon. Some pyloric G cells also showed some reactivity with CCK antiserum, but absorption of CCK antiserum with gastrin C terminal pentapeptide prevented the staining of pyloric cells and provided specific staining of intestinal CCK cells. Anti-human gastrin I serum stained some intestinal cells too. Most of such cells did not react when gastrin antiserum was absorbed with pure CCK (a treatment that did not prevent the staining of pyloric gastrin cells); they were interpreted as cross-reacting CCK cells rather than as intestinal gastrin cells.


The use of ultrasound in the diagnosis of gastroenterological disease.

Ultrasound is high frequency mechanical vibration. As far as is presently known, there are no harmful effects of ultrasound at the energy levels used in currently available commercial ultrasonic scanners. Ultrasonic studies are independent of organ function, are painless, and require nor special preparation. Ultrasonic scanning is useful in the diagnosis of pancreatic disease, especially in the detection of complications of pancreatitis such as pancreatic abscess or pseudocyst, and in diagnosing pancreatic carcinoma. Gallstones and dilation of the biliary tree can be detected ultrasonically even when the patient is jaundiced. Primary liver tumors and hepatic metastases can often be demonstrated. Intraabdominal abscesses are better investigated by ultrasound than by any other means currently available. Ultrasonic scanning also provides a sensitive means of detecting ascites. Ultrasonic control of needle placement has been suggested for pancreatic and liver biopsy, for aspiration of intraabdominal fluid collections, and for percutaneous transhepatic cholangiography. Ultrasonic B-mode scans provide undistorted images of cross sections through the abdomen which can be used in radiotherapy planning to localize tumor masses and to place kidney shields accurately. Organ volumes can be estimated from a set of ultrasonic B-mode scans without any assumptions being made as to the shape of the organ.


The current status of alpha-1-antityrpsin, a protease inhibitor, in gastrointestinal disease.

Extremely deficient levels of alpha-1-antitrypsin (ALPHA1AT) predispose such deficient individuals to the development of emphysema and cirrhosis. Protease inhibitor (Pi) typing has clarified that the inherited deficiency is codominant. A glycoprotein with antigenic characteristics of alpha1AT is found in the endoplasmic reticulum of the hepatocytes of individuals with PiZ phenotype. No therapy is available except liver transplantation. Although biochemical advances in defining the nature of alpha1AT deficiency are progressing, the pathogenesis of the liver disease remains an enigma.


[Competence in Escherichia coli cells. III. Formation of competent states in Escherichia coli X7026 and Escherichia coli Hfr H cells during storage in different conditions].

The competence formation in 2 strains of Escherichia coli X7026 and Hfr H to isolated phage gamma DNA after the prolonged treatment of cells with Ca++ ions at low temperatures was investigated. In both strains studied the sensitivity of cells to phage lambda DNA increased during several days of maintenance at 4 degrees C in 0.2 M CaCl2, and reached the maximal value in 24-48 hours for E. coli Hfr H cells, and in 72-96 hours for E. coli X7026 cells. Cells maintained in CaCl2 for 24 hours and more interacted more effectively with DNA in the cold, and didn't need Ca++ ions at the last stage of transfection (incubation of the infectious mixture at 37 degrees C) as the freshly grown cells did. Variations induced in the cells after the prolonged action Ca++ ions were preserved only in the presence of CaCl2. After the washing of CaCl2 from the cells with 0.15 M NaCl they returned to the initial state. The competence formation in cells of E. coli X7026 under the effect of Ca++ ions was going on more actively when the cells were preliminary incubated for several days at 4 degrees C in the absence of CaCl2. E. coli Hfr H cells were resistant to this treatment.


[New type of mitochondrial mutation in yeasts--temperature-dependent mitochondrial mutations resistant to antibiotics].

Mitochondrial mutants of yeast Saccharomyces cerevisiae XII race resistant to erythromycin, neomycin and monomycin were used in the experiments. It is found that there are mitochondrial mutants resistant to antibiotics at 30 degrees C, but sensitive at 37 degrees C.  In most cases the sensitivity to antibiotics was accompanied by a loss of the ability to growth on non-fermental carbon sources at the elevated temperature (37 degrees C). The genetic analysis revealed the extra-chromosomal inheritance of the markers. Probable interpretation of this phenomenon is discussed.


[Ploidy and liquid-holding recovery in yeasts sensitive to radiation and nitrous acid].

The effects of genome ploidy and posttreatment incubation on inactivation by nitrous acid (NA) were studied in normal, radio- and nitrous acid-sensitive strains of yeast. In normal yeast cells the increase of ploidy (haploid to triploid) resulted in "the protective effect", i.e. haploid cells were the most sensitive, triploid -- the most resistant. This "protective effect" is absent in polyploid yeast homozygous for the xrs1-5 (rad 54) mutation; in this case the NA-sensitivity rises with the increase of ploidy, i.e. haploid cells are the most resistant ones. The effect of liquid holding (LH) after the NA treatment depends on the genetic background and ploidy of treated cells. Posttreatment incubation in buffer has practically no effect on the survival of wild-type Berkeley's yeast strains (1n, 2n, 3n). The highly homozygous haploid strains from Zakharov' collection, both wild type and xrs1-5 mutant, exhibit no LH-recovery too. However the death of wild-type cells drastically rises in LH-condition as the ploidy increases. 24 hours incubation in buffer results in at least a ten-fold decrease in survival of wild type 2n, 3n, 4n cells. The loss of viability is proportional to the time of incubation, but the cell titer being constant. The strains (2n, 3n, 4n) homozygous for the xrs1-5 mutation (rad 54) show considerable LH-recovery. It is supposed that the xrs1-5 mutation results in the derepression of the prereplicative pathway of LH-recovery which eliminates the NA-INDUCED DAMAGE OF DNA.


[Effect of restricting the action of an amber-mutation suppressor contained in bacteriophage T4 genome].

The action of a bacteriophage suppressor can be restricted due to mutations arising in the genome of the host bacteria. Bacterial strains Escherichia coli BN and CAN were isolated in which a complete restriction of the action of phage suppressor psu+ took place. In thees strains obtained the restriction of serin-specific phage suppressors psu + a and psu + b is brought about. The action of bacteriophage suppressor su3+ containing in E. coli CAN is not abolished in this strain. The abolish of the action of glutamine-specific phage suppressor in both strains is not realized. Thus, in bacterial strains of E. coli BN and CAN the restriction of action of only definite tRNA type takes place. Mutation alterations in the bacterial strains obtained can be due to the change of 1) ribosomes, 2) aminoacyl-tRNA-synthetase, 3) suppressor tRNA. In this case the possibility of mutation alterations in the gene controlling the synthesis of suppressor tRNA is excluded, but there is a possibility of changing the tRNA molecule itself during maturation.


[Single-parent inheritance of mitochondrial mutations resistant to tetracycline in Saccharomyces cerevisiae].

The mitochondrial mutation of the resistance to tetracycline (Tr) is shown to have one-parent inheritance. The polarity of recombination between the gene Tr and other mitochondrial mutations also depends on the alleles controlling the mating type as well as in another nuclear gene i, suppressing Tr-resistance. The "arrest" of Tr-transmission in alpha-haploid or in a haploid with gene-suppressor induces the process of mitochondrial recombination.


[Disbalance in the rates of DNA and protein syntheses, occurrence of DNA breaks and viability of cells of rec+-, recA-- and recB--strains of Escherichia coli K-12].

The relationship between the disturbance of the velocity balance (disbalance) of DNA and protein syntheses, the beginning of DNA single-stranded breaks (SB) and their reparation in recA, recB mutants and wild type cells (rec+) is studied. It is found that a strong disbalance of the aforementioned syntheses results in SB of DNA, which are responsible for the death of the cells. The elimination of the disbalance by a balanced inhibition of DNA and protein syntheses contributes to the SB reparation and prevents the cells from the death.


[Reversion induction in phage T4 mutants in Escherichia coli strains with defective RNA polymerase].

The reversion induction in mutants of phage T4 under the effect of base analogues in RNA-polymerase Escherichia coli mutants is studied. In double mutant E. coli rif-r stl-r strain  phage T4 mutates several times more frequently than in the parental strain of E. coli RFS-522, containing an intact enzyme.


[Induced and spontaneous mutagenesis in phage T4 in Escherichia coli strains with mutant RNA polymerase].

Study was made of the frequency of induced and spontaneous mutations in phage T4 in RNA polymerase Escherichia coli strains. It has been shown that the rate of induced mutagenesis by base analogues increases in two rUV-mutants of phage T4 carrying mutations of the transition type, unlike the frameshift mutant which does not revert under these conditions. An increase in the level of spontaneous mutations in the phage is also found when RNA polymerase mutations are introduced into the system. The influence of mutant RNA polymerase on the mutation process is specific as no alteration of the recombination process in phage T4 has been found in E. coli strains with mutant RNA polymerase.


[Immunogenetic analysis of the localization of the Y-factor in the mouse genome. I. Study of interspecific F1 hybrids].

Immunogenetic analysis of Y-factor localization in mouse genome was carried out by means of skin grafts. The data obtained indicate to autosomal localization of Y-factor rather than Y-linked one. This leads to the conclusion that Y-factor is a sex-influenced factor, but not a sex-linked one. If the hypothesis about Y-factor localization in Y-chromosome is accepted, this gene will be identical in CGA and C57B1/6 strains and the variety of reactions, caused by T-antigen, will be determined by the genetical constitution of the male donors and the female recipients.


[Effect of mammalian and Escherichia coli DNA on rat somatic cell chromosomes].

High-polymer DNA isolated from mammalian lymphoid tissues (rat spleen, calf thymus) and from Escherichia coli increases the frequency of quantitative lesions in bone marrow cells of normal Wistar rats. The highest percentage of aberrant metaphases was revealed 24 hours after the injection of mammalian DNA, the frequency of aberrations being 9 times higher than the control values after the injection of heterologous DNA and 6 times higher-after the injection of homologous DNA. The effect observed was not a prolonged one, and 72 hours following the DNA injection the numbers of aberrant cells decreased to the control level. The maximal frequency of aberrations in bone marrow cells of rats treated with bacterial DNA was found 72 hours after the injection, when a 4-fold increase above the spontaneous aberration level was observed. Definite differences in the character of structural changes of chromosomes induced by DNA of different origin were revealed. Mammalian DNA injected produced the chromatid-type aberrations only. The injection of bacterial DNA led to the formation of both chromatid and chromosome aberrations. Possible mechanisms of the increase of chromosome aberration frequency in rat somatic cells under the action of high-polymer DNA of different origin are discussed.


[Genetic-biochemical study of acid phosphatases from Saccharomyces cerevisiae yeasts. IV. Genetic control of acid phosphatase II activity].

Genetic control of exocellular acid phosphatase of yeast Saccharomyces cerevisiae (acph 2) is studied. 64 mutants with the impaired activity of acid phosphatase have been obtained by UV-irradiation. All the mutations have been distributed among 4 genes: ACP1, ACP2, ACP3, ACP4 using functional and recombinational tests for allelism. It is shown that mutations in genes ACP1--ACP3 are recessive, but in the gene ACP4--dominant. The gene ACP4 is found to be located 0.41+/-0.064 in strains from centromere and to have no linkage with ACP1. Possible functions of genes studied are under discussion.


[Mechanism of conjugation in Escherichia coli K-12. IV. Conjugation in conditions of phenotypic suppression of gene dnaB mutation].

The thermosensitive mutation BT43 in the gene dnaB is a missence mutation affecting the vegetative and conjugational DNA synthesis. By means of the increase of ionic strength (NaCl concentration) in the medium the functional activity of the dnaB product is partially restored in non-permissive conditions. In these conditions a rescue of recombinant yield is observed. But the mechanism of recombination is switched from one-stranded to double-stranded. This is demonstrated by the alteration of the degree of linkage of genetically close markers.


[Nuclear suppression of a mitonchondrial mutation of tetracycline resistance in Saccharomyces cerevisiae].

Nuclear suppression of the mitochondrial mutation of tetracycline resistance (Tr) is found. The suppressor mutation (i) is monogenous and recessive. Besides phenotypical suppression of mitochondrial resistance to tetracycline, it causes "the arrest" of the Tr plasmagene transmission. The effect of the suppressor is specific.


[Base pair substitutions induced by Escherichia coli K-12 mutator gene prv].

Using the trpA system of Yanofsky, it is shown that the mutator gene prv of Escherichia coli K-12 induces transitions in both directions (A:T in equilibrium G:C), and not A:T leads to leads to C:G and C:G leads to A:T transversions. The prv1 mutation was found to be recessive in prv+/prv1 merodiploid.


[Mitochondrial marker recombination in yeasts. II. Crosses of isochromosomal and anisomitochondrial strains].

Mitochondrial markers of resistance to antibiotics erythromycin and neomycin were used to study mitochondrial recombination in Saccharomyces cerevisiae bifactorial crosses both in cis and trans configurations of markers. The following parameters of mitochondrial recombination have been examined: a) the asymmetrical transmission of parental classes, b) the frequency and the polarity of recombination and c) the effect of cell mating type on above listed parameters. The counting of results was carried out among random samples of zygotic diploid daughter colonies. The data obtained revealed the following features of mitochondrial recombination: 1. The origin of mitochondria controls all the parameters of mitochondrial recombination. 2. There are discovered two classes of mitochondrial crosses in relation to the polarity of recombination--a) a low polarity as "homosexual" (with types of mitochondria omega- X omega-) and b) a high polarity crosses as (heterosexual) (omega+ X omega+) 3. The linear arrangement of mitochondrial markers of the resistance to erythromycin and neomycin in relation to omega factor is suggested as omega-N-E. 4. The effect of cell mating type on the asymmetrical transmission of parental classes, frequency and polarity of recombination is established. 5. A new class of mitochondria is discovered that can transmit (or recombinate) with very high efficiency by ER-markers, but cannot transmit (or recombinate with) NR-markers.


[Dominant nonsense suppressors restricting the killer activity in Saccharomyces cerevisiae].

Dominant suppressors of the first type nonsense mutations, ade1-6, hisX, lys9-A21 and leu2-2, inhibit the killer activity in Peterhoff genetic stocks of Saccharomyces cerevisiae. Phenotypes CN (weak killer at 20 degrees, neutral at 32 degrees) and N (neutral at both temperatures) arising in the presence of the suppressors in killer strains are dominant toward S phenotype and toward K phenotype.


Migration inhibition with various cell fractions in human colorectal cancer.

The unseparated leucocytes, separated mononuclear cells and granulocytes of six control subjects and nine patients with colorectal cancer have been studied by a direct cell migration inhibition technique. A migratory index was calculated from the migration in the presence and absence of a perchloric acid extract of large bowel tumours. In 10% homologous AB serum, no significant migration inhibition occurred with any of the cells from control subjects. Five of the  nine cancer patients showed significant inhibition with their unseparated leucocytes, seven of seven with their mononuclear cells, and none of nine with their granulocytes. In 10% autologous serum, some controls exhibited migration inhibition with their unseparated leucocytes and their granulocyte fraction, but not with the mononuclear cell fraction. Migration inhibition was also now apparent in the granulocyte fraction of the cancer patients. It is concluded that, with a soluble tumour antigen preparation, a mononuclear cell population increases the sensitivity of the direct migration inhibition test and that autologous serum may interfere directly with the migration of granulocytes, by an action not dependent upon the release of inhibitory factors from sensitized lymphocytes. This could explain some of the inconsistencies of the assay when using an unseparated leucocyte population.


Glucagon and the colon.

The effect of glucagon on human colonic myoelectrical activity is described. By means of intraluminal, serosal, and surface electrodes, recordings from all areas of the large bowel have been obtained. Glucagon inhibited both electrical and pressure rhythms in all subjects tested. Evidence is produced to suggest a direct action on colonic smooth muscle. A controlled trial using glucagon during routine barium enema examinations suggests that it may prove to be useful for hypotonic examinations of the colon where painful spasm is present.


[Modern criticism of psychiatry -- rebellion or return to tradition? (author's transl)].

Modern criticism of psychiatry started about 10 years ago with violent attacks on the ways in which psychiatric patients were handled in practice. In its attempt to shatter rigid structures and to adopt attitudes, wellknown for many years, for therapeutic action, this criticism remains in an historical scientific tradition which can be traced back to the beginning of this century. With the advance of sociologic thinking and the adoption of radical sociogenetic demands, mainly in the Anglo-Saxon literature, this criticism finds its own feet towards the end of the sixties as a kind of antipsychiatry. It obtains its leverage in the lack of differentiation between diagnosis and psychopathologic description in psychiatry ignoring like Birnbaum the "essential" history of psychiatric science dating from the middle of the 19th century, it returns to the psychiatry of late romanticism. It assesses the place of psychiatry within the range of sciences. In a similar manner it opposes the detached, individual-psychologic, approach or classical psychopathology and sees the various psychopathologic data as forms of a deviation in the sense of symbolic interactionism. Modern criticism of psychiatry could, therefore, mark the start of a developing interactional psychopathology which would certainly not have to compete with traditional psychopathology. It could take its place as an independent approach on equal terms with existing trends. A precondition would be a disnissal of a- and antihistoric basic tendencies which alone would make possible the necessary re-interpretation with the developments up to date and with present-day achievements.


Clinical use of LH-RH test as a diagnostic tool.

The response to LH-RH is never characteristic of a given disorder of the hypothalamo-hypophysial-gonadal axis except in the cases of severe gonadal disturbances, but reflects the functional states which can be observed under various circumstances. The same functional state may be found in different diseases and, in contrast, one disease can evolve through different functional states with time.


Treatment of work-related health problems in a work clinic.

Little is known about patients who chronically express work problems through medical complaints or who develop or exaggerate physical problems to avoid work, the authors say. In 1973 a university-affiliated medical clinic set up a multidisciplinary work clinic to study and treat patients with work-related health problems. In general the clinic's first 18 patients showed emotional immaturity and social or psychiatric dysfunction, often severe. After treatment nine of the 18 returned to work, and two began vocational retraining and later took jobs. The authors believe that because of the close relationship between work and health, medical-care institutions must deal with work problems that patients present.


Suppression of the primary immune response in vivo to sheep red blood cells by B-cell mitogens.

Polyacrylic acid (PAAC), lipopolysaccharide (LPS), dextran sulphate (DS) and purified protein derivative of tubercle bacilli (PPD), compounds mitogenic for B lymphocytes in vitro, suppressed the immune response of mice to SRBC in vivo, when injected 4-2 days before immunization. The same compounds enhanced the immune response when injected half an hour before immunization of the animals with a suboptimal antigen dose. A subsequent injection of PAAC given shortly before immunization, abolished the immunosuppressive effect expected by pretreatment of the animals with either PAAC or LPS. A second injection of LPS abolished the immunosuppressive effect of LPS only. The results indicate that when B lymphocytes react with a mitogen in the absence of a particular antigen, they temporarily lose their capacity to respond to antigen.


Should I be using pit and fissure sealants or amalgam?

Results of many trials have shown that fissure sealants can have a highly significant effect in the prevention of occlusal caries. The ultraviolet light cured materials appear to produce the most succesful and reproducible results. No evidence of caries or demineralization has been reported which could be related to acid etching of enamel. Several studies have shown that etched enamel, not covered by resin, will be remineralized on contact with oral fluid. There is evidence to support the argument that a small amount of undiagnosed caries at the base of the fissure would be arrested by the application of sealant. Larger carious lesions must be restored with a suitable material. Microleakage occurs at the margins of restorations as demonstrated in vitro by the use of an artificial caries technique in which 'outer' and 'cavity wall' lesions are produced. The incidence of cavity wall lesions is less if a composite material, rather than amalgam, is used. Microleakage may be decreased further by application of resin to the composite/enamel margins.


A disease-conscious method for sequential diagnosis by use of disease probabilities without assumption of symptom independence.

A method for automatic diagnosis of disease is formulated and applied to a data base of several hundred gastroenterological patients who were each known to have one of six diseases. Application of the method requires no assumptions regarding statistical independence of symptoms. Each disease is associated with its own disease-symptom function, and any order of dependence between the symptoms and each disease may be allowed for. A patient's symptoms are used to determine the value of any specified disease-symptom function. This value is then used to determine the probability that the patient has the corresponding disease. The method is applied to a sequential diagnosis of patients not contained in the initial data base. Additional symptoms are chosen according to their diagnostic value. The entire model is disease-conscious in that disease-symptom functions, disease probabilities and diagnostic values need be evaluated only for those diseases that are considered relevant to the diagnosis.


Outcome studies of therapeutic community and halfway house treatment for addicts.

This paper reviews the outcomes of follow-up studies of addicts in therapeutic communities. The aim is to assess the research problems in such studies and the range of recovery rates found. It was found that controlled studies are few in number and available only for correctional institutions, not for Daytop, Synanon, or Phoenix House. Most studies base outcomes on "graduates" rather than all those taken into the program. Very few graduates of traditional communities exist. Most are employed in drug or social service activities. Few return to employment outside treatment agencies for addicts. Three controlled studies, all with halfway houses,  suggest that they are not more effective than probation. Further controlled studies, especially with agencies such as Daytop and Synanon, are required.


Female drug use: some observations.

This paper, based on a review of recent social science drug research, summarizes the main findings on female drug use and speculates on its future direction. The findings include the following: women are usually initiated into illicit drug use by men; rates of illicit drug use are lower among females than males (which may reflect the greater personal freedom traditionally granted to males), although the difference narrows among younger persons and among those who subscribe to more liberal values and life styles; women are more likely than men to use psychotherapeutic drugs (which may reflect strains resulting from their unequal status vis-à-vis men); and female opiate addicts, although they tend to hold conventional values, are often involved in such deviant activity as prostitution. To the extent that women gain social equality with men and subscribe to greater personal lifestyle freedom, they may be expected to show a higher rate of illicit drug use, particularly of a recreational kind. On the other hand, the rate of psychotherapeutic drug use may decrease, although if the tensions of the workplace eventually substitute for the tensions of status inequality, the resultant changes in rates and patterns of substance use are problematic.


In vitro cultivation of leprosy bacilli on hyaluronic acid based medium. 1. Preliminary report.

In vitro cultivation is reported of Mycobacterium leprae on a medium (designated LA-3) based on hyaluronic acid with additional ingredients of yeast extract, bovine albumin and glycerin together with phosphate buffer. The medium is also incorporated with agar or agarose (designated LA-3P) to serve as culture plates. Initial growth in LA-3 in test tubes required about six weeks but subsequently this was speeded up to about two weeks utilizing large quantities of media with aeration by shaking twice a day. Growth on LA-3P yields numerous small orange-yellow colonies in two to three weeks. Facets of the emerging aspects of the life cycle of M. leprae under cultivation are given preliminary report. The bases for the allegation of M. leprae identity of the cultured bacilli are essentially the following six determinations. 1. Pathologic and experimental determined rationale for the essential M. leprae nutrient requirement. 2. Several cultures having the same characteristics have been isolated from LL patients widely separate in time and by geography. 3. Failure of culture isolates to subculture on the usual media employed in the cultivation of mycobacteria at both 37 degrees C and room temperature. 4. 1 degree cultures in liquid medium successfully transferred to 2 degrees liquid medium and to 2 degrees agar medium plates. 5. Bacillary isolates and bacilli of 1 degree and 2 degrees liquid medium cultures all stain with pooled LL serum, FITC coupled, M. leprae specific antibody with which a broad range of other mycobacteria do not react. 6. M. lepraemurium also presents good growth on this medium.


Specific direct fluorescent antibody identification of Mycobacterium leprae.

In vitro cultivation of M. leprae requires a rapid, specific identification procedure for monitoring the cultures. A method utilizing direct FITC-coupled lepromatous, specific serum globulin is described in detail with suggestions for improvement. After various purification and adsorption procedures, notably against human liver powder and M. tuberculosis, a fluorescent serum preparation is obtained which specifically reacts with M. leprae and not with other mycobacteria.


Modification of radiation effects in single-cell systems by membrane-binding agents.

Chlorpromazine sensitized E. COLI B/r, thymocytes and Yoshida ascites-tumour cells to 60Co gamma-rays, preferentially, under hypoxic conditions, Residual sensitization was observed in E. coli B/r. The radiosensitization by chlorpromazine was found to be due to the reaction of radiolytically-induced hydroxyl radicals with the sensitizer. When both procaine HCI and chlorpromazine were present during anoxic irradiation of E. coli B/r, there was no additive effect. But the addition of procaine HCL after irradiation to cell sensitized by chlorpromazine had an effect that was significantly greater than that produced even by oxygen. A similar effect was observed when lignocaine or tetracaine was used in place of procaine. The possible mechanisms involved in radiosensitization by chlorpromazine and in the post-irradiation effect of local anaesthetics in cells sensitized to 60Co gamma-rays by chlorpromazine are discussed.


Biochemical properties of cultivated Mycobacterium lepraemurium.

1. Dehydrogenase activity of whole cell of cultivated M. lepraemurium is accelerated with sodium laurate, but not with the other substrates. 2. Dehydrogenase activity of cell free extract of cultivated M. lepraemurium is accelerated with citrate or malate. 3. There is no acceleration of oxygen consumption corresponding to added substrates in the respiration activity of whole cells of cultivated M. lepraemurium, but endogenous QO2 is 1.7 mul. 4. Cell free extract of cultivated M. lepraemurium shows slight acceleration of oxygen consumption with NADH, but does not with citrate or alpha-ketoglutarate. 5. NADH is not oxidized rapidly with the particle fraction of cultivated M. lepraemurium. 6. Type b1 cytochrome having an absorption peak at a wave length of 561 mmu and type a2 cytochrome having an absorption peak at 625 mmu are detected in an oxidoreductive difference spectrum or particle fraction of cultivated M. lepraemurium, but type c cytochrome having the absorption peak at 550 mmu is not seen. Since the other cultivable acid-fast bacilli always have type c cytochrome, nondetection of type c cytochrome is characteristic for M. lepraemurium. 7. These cytochromes are reduced with NADH. 8. M. lepraemurium produces a red pigment which emits a red fluorescence with ultraviolet light on its 1% Ogawa yolk medium. This phenomenon is a characteristic of M. lepraemurium, M. avium and M. intracellulare.


R.b.e. of 50 k Vp x-rays and 660 keV gamma-rays (137 Cs) with respect to the production of DNA damage, repair and cell-killing in Escherichia coli K-12.

We have compared the efficiency of cell-killing, DNA single-strand breakage and double-strand breakage in an Escherichia coli K-12 wild-type strain after irradiation with soft X-rays (50kVp) and hard gamma-rays (600 keV) under aerobic conditions. Irradiation with 50 kVP x-rays resulted in 1.47 times more cell killing than was observed with 137Cs gamma-rays based on a comparison of D0 values evaluated from the survival curves. DNA sedimentation studies showed that, although 50 kVp X-rays were 1-93 times more effective than 137Cs gamma-rays in producing DNA double-strand breaks, there was no sigificant difference between the two qualities of radiation with respect to the initial number of single-strand breaks produced. When the cells were irradiated and allowed to repair maximally in minimal medium, 1-57 times more unrepaired DNA single-strand breaks remained per krad after irradiation with 50 kVp X-rays than with 137Cs gamma-rays. The increased yield of DNA double-strand breaks resulting from 50 kVp X-radiation may account for most of these additional unrepaired single-strand breaks, since single- and double-strand breaks are indistinguishable on alkaline sucrose gradients. These results suggest that the greater r.b.e. of 50 kVp X-rays may be related to an increased effectiveness for producing DNA double-strand breaks compared with the higher energy 137Cs gamma-rays.


Immunologic protection of rabbit corneal allografts: prolonged survival of allografts pretreated with homologous antibody against transplantation antigens.

Homologous Dutch pigmented rabbit antibody against New Zealand white rabbit transplantation antigens has been produced. This antibody is much less cytotoxic than similarly prepared heterologous guinea pig antilymphocyte serum. The homologous antibody preparation significantly prolongs corneal allograft survival.


The response of the juxtaglomerular apparatus to stimuli effecting renin or erythropoietin release in canine renal allografts.

The functioning canine renal allograft produces plasma renin activity (PRA) and erythropoietin (ESF) activity and can maintain normal blood pressure and normal erythropoiesis. Moreover, in response to various provocative stimuli it can: (i) increase plasma renin activity in response to low sodium intake; (ii) suppress PRA in response to high sodium intake; (iii) produce increased serum erythropoietin in response to hypoxia. The granulation activity of the juxtaglomerular apparatus correlates best with the degree of graft rejection and with the PRA in groups manipulated by changing sodium balance. This is not the case with hypoxia. Thus, the juxtaglomerular apparatus, even in the presence of vascular changes seen with the severe degree of rejection in renal allografts, can respond to stimuli that can regulate renin release. Renin production by the transplanted kidney can be dissociated from ESF secretion. Blood pressure changes in the present model were not directly associated with increased PRA or juxtaglomerular apparatus activity. In such conditions hypertension can exist in the presence of suppressed PRA and without hypergranulation of the apparatus. The majority of correlations of this study thus establish a close association of the degree of juxtaglomerular index activity with PRA levels, rather than ESF.


Histogenesis of B and T lymphocytes.

There are striking differences in the histogenesis of B and T cells. 1) The formation of B lymphocytes seems to be closely associated with that of other blood cells, whereas the formation of T cells is not. 2) In postnatal life, the bone marrow is a mojor site for the formation of B cells, while T cells are produced mainly in the thymus. 3) B cells are formed in a short production pathway, consisting of two or three mitoses, whereas T cells are formed in a long production pathway, consisting of about eight mitoses. 4) The starting point for the short production pathway is a large transitional cell. The long production pathway starts with a reticulum cell, a large lymphoblast or a cell which has been termed "monocytoid". 5) Plasma proteins have ready access to the cells of the short production pathway in bone marrow, but because of the blood-thymus barrier are not as readily accessible to the tissure involved in T cell formation in the long production pathway in the thymus.


Effect of phospholipids on the activity of DNA polymerase I from E. coli.

Sphingomyelin, phosphatidylethanolamine and lecithin at concentrations which destabilize the DNA helix enhance the DNA polymerase activity, but sphingosine and phosphatidylserine have only a moderate effect. MgCl2 was shown to modify the action of sphingomyelin on the DNA polymerase activity. The role of phospholipids in the DNA replicating process was analyzed.


Transplant nephrectomy and simultaneous second graft retransplantation.

Tranplant nephrectomy and retransplantation has become an established modality in treating patients with rejected kidney allografts. Experience with 29 patients who underwent simultaneous transplant nephrectomy and retransplantation is presented. This procedure did not involve a considerably greater risk than a primary transplant and had an almost equal rate of success. There was no significant correlation between survival or failure of the second graft and the time the patient had been on dialysis prior to the first transplant, the duration of first graft survival, or the source of the first or second kidney. Seventy-five percent of the failures in the second transplant group were due to hyperacute or accelerated rejection, and only 25% were rejected in an acute or chronic fashion. The high frequency of hyperacute and accelerated rejections is presumably a result of presensitization by the first transplant. An inadequate supply of cadaver kidneys prevented performance of the simultaneous procedure in all patients that required it.


Membrane immunoglobulin on mouse myeloma cells: discrepancies in the detection of membrane IG by two different methods.

Two different methods, immunofluorescence and lactoperoxidase-catalysed radioiodination, were used to investigate mIg on two different myeloma cell lines. The data indicate that, even though both techniques are highly sensitive, different results can be obtained in the same cell line depending on the technique employed.


Atrial and ventricular asystole for 19 seconds without syncope. Report of a case.

A 58-year-old male presented with a three-year-long history of short attacks of loss of consciousness. Epilepsy was suspected and phenobarbital and diphenylhydantoin were given, but without effect. Ambulatory ECG monitoring for four days revealed episodes of sinus bradycardia, marked sinus arrhythmia, and episodes of atrial and ventricular standstill. The longest asystolic period, without escape of lower pacemakers, was 20 sec and was recoreded during undisturbed sleep. Another long atrial and ventricular asystolic period with a duration of 19 sec, recorded during daily activity, was accompanied by dizziness but without loss of consciousness. The patient's symptoms were relieved by implantation of a pacemaker.


[Development in the immunotherapy of malignant melanoma].

Recent progress in the investigation of malignant melanoma has encouraged the possibilities of using immunological methods in the treatment of cancer. Under investigation are especially attempts to influence both the humoral and cellular immunity with cytotoxic effect on tumor cells. In perspective of these studies schedules for greater effectiveness of immunotherapy by combination of active, passive, eliminative or adoptive methods are conceivable. They provide a rational basis particulary because essential questions of alternation between the immune reactions are not yet understood.


[Model experiments on the effect of IgM- and IgG-antibodies on the reactivity of Treponema pallidum hemagglutination (TPHA)-test].

Fractionated sera of patients in different stages of syphilis were examined comparatively with the TPHA-FTA(IgM)- and FTA(IgG)-test. It was shown that the TPHA-test proved to be convenient for early immunologic diagnosis of syphilis. The TPHA-test includes not only IgG anti-treponemal antibodies but also IgM antibodies. In the early stage of syphilis a reactive result of TPHA-test can be related exclusively on treponemal specific IgM antibodies.


[Mixed bullous diseases].

As mixed bullous diseases are presented the intermediate forms between bullous pemphigoid (BP) and dermatitis herpetiformis (DH) with clinical and histologic features of both diseases, and with linear deposits composed exclusively or mainly of IgA at the basement membrane zone in the direct immunofluorescence test. This type of mixed bullous disease is more common in children (juvenile DH), although typical DH and BP cases as in adults occur also in childhood. Also herpes gestationis seems to be related to mixed bullous diseases with prevalence of immunologic phenomena characteristic of BP, although its IF pattern may be regarded as diagnostic (usually absence of circulating and in vivo bound antibasement antibodies, and presence of some complement components at the dermal-epidermal juncti0n). Especially controversial is in this group a variety of pemphigus with clinical features of DH, and good response to sulfapyridine of some cases, presenting acantholysis and immunological phenomena specific for pemphigus. For this form of pemphigus the term herpetiform pemphigus has been proposed. In the group of mixed bullous diseases should also be included cases of coexistence-in different periods, or concomitantly-of pemphigus and BP.


[The voice as a mirror of personality (author's transl)].

The philosopher and astrologer Scotus, who was famous for his translations from Greek and Arabic into Latin wrote a handbook of physiognomy for Emperor Friedrich II about 1228 A.D. In this volume based particularly on Arabic sources is a chapter on the voice. It contains numerous details that suposedly enable recognition of certain personality traits by voice characteristics. In the present such concepts are familiar, but that it was of practical relevance 750 years ago may justify closer inspection of Scotus and his work.


Use of a formalin-treated, live Escherichia coli vaccine in the prevention of neonatal enteric colibacillosis in swine.

A field trial was conducted to evaluate the effectiveness of an Escherichia coli vaccine in prevention of neonatal enteric colibacillosis in swine. Sows (272 total) were allotted to control (151 sows) and vaccinated groups (121 sows). Sows in the vaccinated groups were given a single intramuscular injection of a formalin-treated, live E coli vaccine 10 to 20 days prior to farrowing. The effects of the vaccination were to: (1) reduce mortality from 2.14 to 0.93 (P less than 0.001) pigs per litter; (2) reduce number of pigs with diarrhea, from 7.28 to 3.12 (P less than 0.004) per litter; and (3) increase number of pigs weaned, from 7.62 to 8.2 (P less than 0.005) per litter. The advantages of vaccination were most apparent in the barns with less than adequate sanitation and ventilation.


Immunofluorescence testing in a bullous skin disease of a dog.

A chronic skin disease in a dog, which resembled a pemphigus-like condition, was studied histologically and by direct immunofluorescence testing. Histologic examination revealed a bullous disorder and was a useful diagnostic tool; however, direct immunofluorescence testing showed the disease to be equivalent to bullous pemphigoid of man.


Localization of smooth muscle-like contractile proteins in kidney by immunoelectron microscopy.

Contractile proteins of smooth muscle type were found in kidney cells by immunological methods. The reactions of rabbit anti-actin, anti-heavy meromyosin and anti-myosin antisera with rat kidney were investigated by immunoelectron microscopy. Anti-actin stained specifically the foot processes of epithelial cells in the glomerulus, the basal processes of tubular epithelial cells, and the cytoplasm of smooth muscle cells. Anti-heavy meromyosin stained the foot processes at their bases near the cell membrane and close to the basement membrane. Anti-myosin stained the cytoplasm of vascular smooth muscle cells. It is suggested that actin and heavy meromyosin-like proteins may act together to cause movement of foot process cytoplasm.


Training children with asthma to use inhalation therapy equipment.

In Experiment I, four children with asthma were taught to use the intermittent positive-pressure breathing (IPPB) apparatus, a device that delivers bronchodilator medication to the lungs under positive pressure. Because these youngsters had not learned to use the device with repeated instructions, script with back-up reinforcement was introduced to train sequentially three responses - eye fixation, facial posturing, and diaphragmatic breathing - according to a multiple-baseline design. The procedures were effective in teaching appropriate use of the IPPB apparatus. Further, the children's use of the apparatus after training resulted in significantly more effective relief of asthma symptoms. In a second experiment, nurses were instructed in the application of the operant techniques used in the first study, and then served as experimenters in a partial replication of Experiment I. The data once again reflected a strong impact of the intervention program on IPPB responses.


Discontinuous synthesis of lac messenger ribonucleic acid in a mutant of Escherichia coli with a new lac promoter.

A mutant of Escherichia coli with a new promoter for the lac operon exhibits dramatic discontinuities in the synthesis of lac messenger ribonucleic acid after induction. These discontinuities immediately precede similar discontinuities in the synthesis of beta-galactosidase. The discontinuous synthesis of beta-galactosidase persists after addition of rifampin.


Changes in active transport, intracellular adenosine 5'-triphosphate levels, macromolecular syntheses, and glycolysis in an energy-uncoupled mutant of Escherichia coli.

The temperature-sensitive Escherichia coli mutant ecfts metC (Lieberman and Hong, 1974), previously shown to be defective in the coupling of metabolic energy to active transport, is also altered in a wide variety of cellular activities at the nonpermissive temperature. These alterations include a lowering of intracellular adenosine 5'-triphosphate levels, an alteration of glucose metabolism such that large quantities of pyruvate and dihydroxyacetone phosphate are excreted into the medium, excretion of accumulated potassium ions, and a cessation of deoxyribonucleic acid, ribonucleic acid, and phospholipid synthesis. Since these effects closely mimic the action of colicins E1 and K on E. coli cells, the possibility that the ecf gene product is the primary biochemical target for these colicins is discussed.


Escherichia coli mutants with altered ribosomal ribonucleic acid metabolism.

This paper reports the partial characterization of two temperature-sensitive mutants of Escherichia coli with alterations in ribosomal ribonucleic acid (rRNA) metabolism at the restrictive temperature. Both mutants continue to synthesize deoxyribonucleic acid and protein at 42 C but showed little or no accumulation of RNA. Both strains are inducible for beta-galactosidase at the restrictive temperature, showing that messenger RNA synthesis continues and that the messenger RNA is translated into functional protein. One of the strains, 2S474, shows a rather severe depression (sevenfold) in the synthesis of all classes of RNA at 42 C. In addition, the synthesis of rRNA is selectively depressed, with the percentage of rRNA synthesis. However, there appears to be a selective depression in the rate of rRNA synthesis and, possibly, in the conversion of p16S rRNA to m16S rRNA.


In vivo transcription of R-plasmid deoxyribonucleic acid in Escherichia coli strains with altered antibiotic resistance levels and/or conjugal proficiency.

The amounts of plasmid deoxyribonucleic acid (DNA) and the levels of the in vivo transcription of the Escherichia coli plasmids R538-1 (repressed for conjugal transfer) and R538-1drd (derepressed for transfer) were determined by DNA-DNA hybridization and DNA-ribonucleic acid hybridization, respectively. The results demonstrate that the level of plasmid transcription is increased by two-fold in the strain carrying the derepressed plasmid, compared to an isogenic strain carrying the repressed plasmid, whereas the amount of plasmid DNA is approximately the same, suggesting that the transfer genes are under transcriptional control. Levels of plasmid DNA, plasmid DNA transcription, and chloramphenicol acetyltransferase activity were also compared in a mutant strain that carried the R538-1drd plasmid and was resistant to high levels of antibiotics. This strain produces about 13 copies of plasmid DNA per chromosome compared to five copies for the parent strain. The level of transcription of plasmid DNA was found to be twofold higher in the high-level resistant strain, whereas the level of chloramphenition, acetyltransferase activity was increased by 10-fold. In addition  the levels of plasmid DNA transcription and chloramphenicol acetyltransferase activity in the high-level resistant strain were found to be further increased by the presence of high levels of chloramphenicol in the growth medium. The amount of plasmid DNA remained constant under these conditions, indicating that high levels of chloramphenicol can stimulate the expression of plasmid genes at the level of transcription in this strain.


Effect of mutations in deoxyribonucleic acid repair pathways on the sensitivity of Escherichia coli K-12 strains to nitrofurantoin.

Escherichia coli K-12 strains that carry mutations in one or more genes coding for proteins involved in repair of deoxyribonucleic acid lesions are more sensitive to the antibiotic nitrofurantoin than are the nonmutant parent strains.


Kinetics of thymineless death in Escherichia coli 15 as measured by single-cell observations.

Kinetics of thymineless death for Escherichia coli 15 TAU-bar from plating on solid medium were compared with those from direct observations of single cells under a microscope. The latter method did not involve any physical change of the medium. The kinetics obtained for the two methods were identical. This rules out the assumption that in E. coli 15 TAU-bar death from the thymine deprivation is directly associated with the plating procedure.


In vivo distribution of ribonucleic acid polymerase between cytoplasm and nucleoid in Escherichia coli.

Three forms of ribonucleic acid polymerase can be distinguished in exponentially growing Escherichia coli cells: (i) active, (ii) inactive, inside the nucleoid, and (iii) inactive, free in the cytoplasm.


Effect of growth conditions on glutamate transport in the wild-type strain and glutamate-utilizing mutants of Escherichia coli.

The effects of growth conditions on the glutamate transport activity of intact cells and membrane vesicles and on the levels of glutamate-binding protein in wild-type Escherichia coli K-12 CS101 and in two glutamate-utilizing mutants, CS7 and CS2TC, were studied. Growth of CS101 on aspartate as the sole source of carbon or nitrogen resulted in a severalfold increase in glutamate transport activity of intact cells and membrane preparations to levels characteristic of the operator-constitutive mutant CS7. The high glutamate transport activity of mutant CS7 was not depressed further by growth on aspartate. Synthesis of glutamate-binding protein was not enhanced by aspartate in either strain. Mutant CS2TC produces a heat-labile repressor of glutamate permease synthesis and is therefore able to grow on glutamate at 42 C but not at 30 C. CS2TC cells grown in a glycerol-minimal medium at the restrictive temperature (30 C) exhibit low glutamate transport activity. Growth on aspartate at 30 C results in derepressed synthesis of glutamate permease. Cells grown on glycerol at 42 C have high glutamate transport activity. No further derepression is obtained upon growth on aspartate. Growth of CS101 and CS7 in "rich broth" greatly reduces the levels of glutamate-binding protein but does not appreciably affect glutamate transport by whole cells or membrane preparations. The identity of the carrier and the role of the binding protein in glutamate transport are discussed in the light of these findings.


Glutamate transport in membrane vesicles of the wild-type strain and glutamate-utilizing mutants of Escherichia coli.

A highly specific energy-dependent glutamate transport system was demonstrated in membrane vesicles of glutamate-utilizing Escherichia coli K-12 mutants. The glutamate transport activity of membranes from the parent strain, unable to grow on glutamate, was very low. With ascorbate-phenazine methosulfate as the electron donor, mutant preparations displayed 17 to 20 times higher activity than did the wild type. However, the affinity of the mutant carrier for L-glutamate remained the same as in the parent strain. Comparative inhibition analysis of glutamate transport in whole cells and membrane vesicles and of in vitro binding of glutamate to a specific periplasmic-binding protein suggests that under certain conditions the latter may be a component of the E. coli K-12 glutamate transport system.


Excision repair of ultraviolet-irradiated deoxyribonucleic acid in plasmolyzed cells of Escherichia coli.

A system of cells made permeable by treatment with high concentrations of surcrose (plasmolysis) has been exploited to study the excision repair of ultraviolet-irradiated deoxyribonucleic acid in Escherichia coli. It is demonstrated that adenosine 5'-triphosphate is required for incision breaks to be made in the bacterial chromosome as well as in covalently closed bacteriophage lambda deoxyribonucleic acid. After plasmolysis, uvrC mutant strains appear as defective in the incision step as the uvrA-mutated strains. This is in contrast to the situation in intact cells where uvrC mutants accumulate single-strand breaks during postirradiation incubation. These observations have led to the proposal of a model for excision repair, in which the ultraviolet-specific endonuclease, coded for by the uvrA and uvrB genes, exists in a complex with the uvrC gene product. The complex is responsible for the incision and possibly also the excision steps of repair. The dark-repair inhibitors acriflavine and caffeine are both shown to interfere with the action of the adenosine 5'-triphosphate-dependent enzyme.


Transposition of a deoxyribonucleic acid sequence encoding trimethoprim and streptomycin resistances from R483 to other replicons.

R483, a plasmid of the Ialpha incompatibility group, contained a deoxyribonucleic acid (DNA) sequence encoding resistance to trimethoprim (TpR) and streptomycin (SmR) that could be transposed to other replicons, i.e., to the Escherichia coli chromosome and to related and unrelated plasmids. Each transposition resulted in the acquisition by the recipient replicon of a segment of DNA of about 9 X 10(6) daltons, both resistance genes, but never the colicin Ia or pilus genes of R483. Transposition took place at a single chromosomal site between dnaA  and ilv and did not suppress the DnaA phenotype, in contrast to integration of the whole R483 plasmid. The chromosome, having received the transposition, could secondarily act as a transposition donor to another plasmid. Such a plasmid was indistinguishable from one having received a direct transposition from R483. TpR SmR transposition was very site specific and did not require a functional recA+ gene. We postulate that the TpR SmR segment of R483 is a transposon (TnC) with specific boundary sequences.


Regulation of lysine transport by feedback inhibition in Saccharomyces cerevisiae.

A steady-state level of about 240 nmol/mg (dry wt) occurs during lysine transport in Saccharomyces cerevisiae. No subsequent efflux of the accumulated amino acid was detected. Two transport systems mediate lysine transport, a high-affinity, lysine-specific system and an arginine-lysine system for which lysine exhibits a lower affinity. Preloading with lysine, arginine, glutamic acid, or aspartic acid inhibited lysine transport activity; preloading with glutamine, glycine, methionine, phenylalanine, or valine had little effect; however, preloading with histidine stimulated lysine transport activity. These preloading effects correlated with fluctuations in the intracellular lysine and/or arginine pool: lysine transport activity was inhibited when increases in the lysine and/or arginine pool occurred and was stimulated when decreases in the lysine and/or arginine pool occurred. After addition of lysine to a growing culture, lysine transport activity was inhibited more than threefold in one-third of the doubling time of the culture. These results indicate that the lysine-specific and arginine-lysine transport systems are regulated by feedback inhibition that may be mediated by intracellular lysine and arginine.


Kinetics of labeling of the S-adenosylmethionine pool of Saccharomyces cerevisiae.

A method has been developed for studying the specific activity of the pool of S-adenosylmethionine in yeast. The pool reaches half-maximal specific activity within 30 s after the addition of [methyl-3H]methionine. After addition of an excess of nonradioactive methionine, the specific activity of S-adenosylmethionine is reduced by half within 20 s. During that period there is a substantial expansion of the pool. A logarithmically growing cell in synthetic medium contains about 2 X 10(6) molecules of S-adenosylmethionine, of which only 10% is used for the methylation of ribonucleic acid molecules.


Biosynthesis and assembly of envelope lipoprotein in a glycerol-requiring mutant of Salmonella typhimurium.

A glycerol-requiring mutant of Salmonella typhimurium was used in a study of the biosynthesis and assembly of a structural lipoprotein in the cell envelope of gram-negative bacteria. Upon removal of glycerol from the growth medium, the biosynthesis of lipoprotein, as measured by radioactive arginine incorporation, was reduced by the same extent as that of other envelope proteins, the cumulative incorporation of arginine being 20% of that of the unstarved control cells. However, the incorporation of radioactive palmitate into lipoprotein was more severely curtailed after glycerol starvation, the cumulative rate of which was 8% of that observed in the unstarved cells. It was further observed that the lipoprotein synthesized in the glycerol-starved cells was more enriched in unmodified cysteine, which is known to be the N-terminal amino acid of lipoprotein, than that synthesized in the unstarved cells. We conclude that the synthesis of the apoprotein portion of Braun's lipoprotein proceeds independently of the attachment of diglyceride to the sulfhydryl group of the N-terminal cysteine and may, in fact, precede the incorporation of the diglyceride moiety.


Utilization of D-asparagine by Saccharomyces cerevisiae.

Yeast strains sigma1278b and Harden and Young, which synthesize only an internal constitutive form of L-asparaginase, do not grow on D-asparagine, as a sole source of nitrogen, and whole cell suspensions of these strains do not hydrolyze D-asparagine. Strains X2180-A2 and D273-10B, which possess an externally active form of asparaginase, are able to grow slowly on D-asparagine, and nitrogen-starved suspensions of these strains exhibit high activity toward the D-isomer. Nitrogen starvation of strain X218O-A2 results in coordinate increase of D- and L-asparaginase activity; the specific activity observed for the D-isomer is approximately 20% greater than that observed for the L-isomer. It was observed, in studies with cell extracts, that hydrolysis of D-asparagine occurred only with extracts from nitrogen-starved cells of strains that synthesize the external form of asparaginase. Furthermore, the activity of the extracts toward the D-isomer was always higher than that observed with the L-isomer. A 400-fold purified preparation of external asparaginase from Saccharomyces cerevisiae X218U-A2 hydrolyzed D-asparagine with an apparent Km of 0.23 mM and a Vmax of 38.7 mumol/min per mg of protein. D-Asparagine was a competitive inhibitor of L-asparagine hydrolysis and the Ki determined for this inhibition was approximately equal to its Km. These data suggest that D-asparagine is a good substrate for the external yeast asparaginase but is a poor substrate for the internal enzyme.


Active site of ribonucleoside diphosphate reductase from Escherichia coli. Inactivation of the enzyme by 2'-substituted ribonucleoside diphosphates.

Ribonucleoside diphosphate reductase is an allosteric enzyme consisting of two nonidentical subunits, proteins B1 and B2. B1 contains dithiols which participate in the oxidation-reduction reactions of electron transport, while B2 contains a free radical essential for activity. Ribonucleoside diphosphates are bound to B1 but not to B2. Addition of 2'-deoxy-2'-chloro ribonucleoside diphosphates to ribonucleotide reductase irreversibly inactivates B1 without affecting B2. The reaction is specific since (a) it requires the presence of active B2, (b) it is controlled by allosteric effectors, (c) B1 is protected against inactivation by the normal substrates, and (d) the chloro-substituted nucleoside monophosphates have no effect. The inactivation of B1 is caused by a modification of the oxidation-reduction dithiols. The chloro derivatives decompose into free base, chloride ion, and 2-deoxyribose 5-diphosphate as a consequence of reaction with the enzyme. 2'-Deoxy-2"-azido ribonucleoside diphosphates cause an irreversible inactivation of B2 without affecting B1. The reaction is specific by the above criteria, indicating that the azido derivatives also bind to the active site of the enzyme. On reduction by ribonucleotide reductase, the azido derivatives function as radical scavengers and selectively destroy the free radical of B2, indicating that this radical participates in ribonucleotide reduction directly. On the basis of these results, a model of the active site of ribonucleotide reductase is proposed in which the site is formed from both B1 and B2. In the site the electron-donating oxidation-reduction active dithiols of B1 are in close contact with the free radical of B2. The azido derivative also inactivates the adenosylcobalamin-dependent ribonucleoside triphosphate reductase from Lactobacillus leichmannii and a ribonucleotide reductase preparation from calf thymus, indicating a general involvement of free radical intermediates in enzyme-catalyzed ribonucleotide reduction.


Yeast DNA-dependent RNA polymerase I. A rapid procedure for the large scale purification of homogeneous enzyme.

A procedure has been developed for the rapid purification of large amounts of yeast RNA polymerase I (A). The method involves batchwise treatment with phosphocellulose and DEAE-cellulose, ion filtration chromatography on DEAE-Sephadex, sucrose gradient centrifugation, and DNA-cellulose chromatography. The enzyme obtained is apparently homogeneous by sedimentation velocity analysis and has a specific activity of 300 nmol of UMP incorporated into RNA in 10 min per mg of protein. Between 30 and 45 mg of enzyme can be obtained in 5 days from 3.0 kg of yeast cells. The subunit composition of the enzyme was determined by polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate. The purified polymerase is composed of 11 putative subunits with molecular weights 185,000 (Ia), 137,000 (Ib), 48,000 (Ic), 44,000 (Id), 41,000 (Ie), 36,000 (If), 28,000 (Ig), 24,000 (Ih), 20,000 (Ii), 14,500 (Ij), and 12,000 (Ik). Yeast polymerase I separates into two forms when subjected to gel electrophoresis under nondenaturing conditions. The main component which migrates faster contains all the subunits except the polypeptides Ic and If. The slow migrating component which is present in lower amounts contains all the subunits.


Conditional spore cortex-less mutants of Bacillus sphaericus 9602.

Lysine-requiring mutants of Bacillus sphaericus 9602 were isolated and classified into three groups by their mutation site in the pathway of lysine biosynthesis. The Group I mutant lacks meso-alpha, epsilon-diaminopimelic acid (meso-Dap) decarboxylase activity, but Group II and III mutants have a normal level of Dap decarboxylase activity. A Group II mutant makes dipicolinic acid from an intermediate in the lysine pathway, but Group III mutants do not. In the absence of meso-Dap in the culture, muramic lactam content in the spore cortex of Group II and III mutants is very low, compared to the wild type content. Addition of meso-Dap to the culture causes an increase of muramic lactam content. Since meso-Dap is detectable only in the spore cortex of B. sphaericus 9602, almost all of the muramic lactam in the spore is probably also located in the cortex. Group I mutants grown in the presence of L-lysine sporulate normally. Group II and III mutants produce oval and nonrefractile spores under the same conditions but the addition of meso-Dap to the culture results in the production of round and refractile spores. Thus, the presence of cortex in the spore is essential to give the round and refractile spores in B. sphaericus. The presence of cortex is also required for the accumulation of dipicolinic acid in the sporulating cells. Furthermore, 1-octanol resistance of the spore depends only on the presence of cortex but both cortex and dipicolinic acid are required for heat resistance of the spore.


Evidence for a conformational change in tRNAPhe upon aminoacylation.

A conformational difference between the structure of tRNAPhe and Cbz-Phe-tRNAPhe from Escherichia coli was detected using the spin label method. A comparison of the respective rotational correlation time (tau c) values of three differently located spin labels, indicates that upon aminoacylation of tRNAPhe, the 4-thiouridine residue region and the miniloop region become more flexible, while the environment of the anticodon loop is not affected. These observations suggest that the main difference in structure between charged and uncharged tRNA resides in the release and exposure of the TpsiC loop for eventual binding to the ribosomes.


Modification and restriction of T-even bacteriophages. In vitro degradation of deoxyribonucleic acid containing 5-hydroxymethylctosine.

Using the single-stranded circular DNA of bacteriophage fd as template, double-stranded circular DNA has been prepared in vitro with either 5-hydroxymethylcytosine ([hmdC]DNA) or cytosine ([dC]DNA) in the product strand. Extracts prepared from Escherichia coli cells restrictive to T-even phage containing nonglucosylated DNA degrade [hmdC]DNA to acid-soluble material in vitro, but do not degrade [dC]dna. In contrast, extracts prepared from E. coli K12 rglA- rglB-, a strain permissive to T-even phage containing nonglucosylated DNA, do not degrade [hmdC]DNA or [dC]DNA. In addition, glucosylation of the [hmdC]DNA renders it resistant to degradation by extracts from restrictive strains. The conversion of [hmdC]DNA to acid-soluble material in vitro consists of an HmCyt-specific endonucleolytic cleavage requiring the presence of the RglB gene product to form a linear molecule, followed by a non-HmCyt-specific hydrolysis of the linear DNA to acid-soluble fragments, catalyzed in part by exonuclease V. The RglB protein present in extracts of E. coli K12 rglA- rglB+ has been purified 200-fold by complementation with extracts from E. coli K12 rglA- rglB-. The purified RglB protein does not contain detectable HmCyt-specific endonuclease or exonuclease activity. In vitro endonucleolytic cleavage of [hmdC]DNA thus requires additional factors present in cell extracts.