Galactolipid fatty acid composition in adrenoleukodystrophy.

The non-hydroxy and hydroxy fatty acids of the major brain galactosphingolipids, cerebroside and sulphatide, have been isolated from white matter, gray matter and myelin of 2 children with adrenoleukodystrophy and from a corresponding control. In addition, cerebroside fatty acids were recovered from a myelin-related fraction on 1 patient. In comparison to control observations, myelin and the myelin-related fraction cerebroside demonstrate a loss of C24:1 and C24h:o fatty acids from normal and hydroxy fatty acid fractions, respectively. White and gray matter galactolipids isolated from 1 patient indicated a signficant increase in short chain (C16, C18 and C18:1) non-hydroxy fatty acids. In the isolated diseased myelin, the ratio of cerebroside hydroxy to non-hydroxy fatty acids was elevated about 1.5 times above the value for normal myelin, whereas the ratio derived for the myelin-related fraction was about two-thirds the values for the control myelin cerebroside.


HLA phenotype A2;B12 in vitamin B12 neuromyelopathy.

Severe neurological complications (either peripheral neuropathy, subacute combined degeneration of the cord or cerebral changes) are a characteristic feature in some patients with marked vitamin B12 deficiency. Although Addisonian pernicious anaemia (PA) is the major cause of this neurological syndrome, the disorder has been described in association with other conditions in which there is a profound depletion of vitamin B12 stores. Sixteen patients with vitamin B12 neuromyelopathy, associated with PA, have been HLA-typed for 27 alleles of the A and B loci and compared with 53 cases of PA without neurological damage and 60 controls of the same ethnic group. There is a significantly increased frequency of the HLA phenotype. A12;B12 (44% instead of 4% in PA patients without neurological damage) in the disease group studied (P less than 0.0005). The signficance of these findings in relation to the pathogenesis of vitamin B12 neuromyelopathy is discussed.


Commissural myelotomy.

The effect of commissural myelotomy in 24 cases with intractable pain is described. The operative technique employed with the operating microscope or magnifying glasses and a special myelotome is outlined. The results suggest an outstanding advantage in patients with bilateral metastases from malignancies except intrapelvic metastases. Patients with lumbar arachnoiditis showed a total failure of pain relief after 2 to 5 years, in spite of good relief temporarily.


The peroneal muscular atrophy syndrome. Clinical, genetic, electrophysiological and nerve biopsy studies. Part 2. Observations on pathological changes in sural nerve biopsies.

The light-and electron-microscopic, single teased nerve and morphometric studies of a series of 17 sural nerve biopsies from patients with personeal muscular atrophy are presented. The cases are divided into the following groups according to the criteria of Davis, Bradley and Madrid (1977): Hypertrophic Neuropathy Group; Intermediate Group; Neuronal Sensorimotor Group; Neuronal Motor Group. The Hypertrophic Neuropathy Group had nerve hypertrophy and marked segmental demyelination and onion bulb formation. The Intermediate Group also had segmental demyelilination and onion bulb formation, but nerve hypertrophy was not seen, and axonal degeneration and regeneration were prominent. The Neuronal Sensorimotor Group cases were all sporadic, and showed some onion bulbs, paranodal demyelination and evidence of axonal degeneration and regeneration. The sensory nerve biopsy in the Neuronal Motor Group showed no major abnormality apart from some cluster formation indicating axonal regeneration. The data tend to support the classification of peroneal muscular atrophy proposed by Davis et al. (1977), though there was overlap between the groups in individual pathological parameters.


Human chorionic gonadotropin produced by ectopic pinealoma in a girl with precocious puberty. Case report.

A case is reported in which a human chorionic gonadotropin (HCG-)-producing ectopic pinealoma was found in a 5-year-old girl with precocious puberty. Physical examination revealed abnormal breast enlargement. Endocrinological study disclosed a high plasma HCG concentration of 1192 ng/ml with a normal follicular stimulating hormone (FSH) level. The HCG content of the tumor was as high as 400 ng/mg of acetone dried tissue, but no FSH was detectable. This is the first reported case of precocious puberty associated with pineal tumor in a female.


Preoperative diagnosis of brain-stem abscess by computerized tomography with survival. Case report.

A case is reported in which the diagnosis of brain-stem abscess was made preoperatively by computerized tomography. Surgical therapy resulted in relatively good functional recovery.


Sarcoid of the cauda equina. Case report.

An unusual case of sarcoid involving the cauda equina, resulting in progressive paraparesis, is presented. There was no evidence of sarcoid involvement outside the nervous system, and the diagnosis was established through thoracolumbar exploration. The patient was treated with steroids postoperatively, and had a moderate recovery of neurological function.


Anomalous course of the recurrent motor branch of the median nerve in a patient with carpal tunnel syndrome.

A case is discussed in which carpal tunnel syndrome with an unusual course of the motor recurrent branch was discovered at operation. The importance of a careful dissection of the median nerve in this condition is emphasized.


An unusual atlanto-axial dislocation. Case report.

A case is presented in which the patient sustained a complete dislocation of the odontoid process in front of the anterior arch of the first cervical vertebra. There was no fracture of the arch of C-1 vertebra. The patient was treated successfully by trans-oral excision of the odontoid process and the anterior arch of C-1. Twenty days later the patient's spine was stabilized posteriorly at C-1 through C-3 with wire and methyl-methacrylate.


Intraparenchymal embolization for obliteration of an intramedullary AVM of the spinal cord. Technical note.

A new technique is presented in which expandable compressed Ivalon sponge emboli were used to obliterate an intramedullary arteriovenous malformation of the spinal cord by intraparenchymal embolization. A case is described in which this method was used.


Epidermoid and dermoid cysts. Clinical evaluation and late surgical results.

The authors report on the clinical data, operating technique, postoperative complications, and late results in a series of 31 epidermoid and 21 dermoid cysts of the central nervous system.


A fast method of estimating the elastance of the intracranial system.

The authors describe a fast method for estimating the elastance of the intracranial system in man. The method consists in constructing the so-called amplitude-pressure (Amp-P) curve which describes the relationship between the amplitude of pulse-related oscillations in cerebrospinal fluid pressure and the basic level of intracranial pressure. The Amp-P curve consists of two straight lines, and the point of intersection of these lines is thought to indicate the intracranial pressure level at which there occurs a qualitative change in the functioning of compensatory mechanisms of the intracranial system. The authors applied the method to examine the Amp-P curves of 10 patients without intracranial pathology and found that they provide a good description of the state and dynamics of the intracranial system. Preliminary data obtained in patients with intracranial pathology indicate that the method is a valuable tool in the diagnosis and treatment of neurosurgical patients.


Safety of mini-dose heparin administration for neurosurgical patients.

A course of small doses of heparin given subcutaneously before and after elective operations has been reported to reduce the incidence of deep venous thrombosis and pulmonary embolism in general surgical patients. To test the safety of mini-dose heparin for neurosurgical patients, mini-dose heparin was used for 150 adult patients undergoing elective neurosurgical procedures. No operative complications were thought to be related to heparin administration. Postoperatively, there were four wound seromas, two hematomas, and one non-fatal pulmonary embolus. Seven patients died postoperatively, of whom five had no evidence of pulmonary embolus. Although no conclusions were drawn as to the effectiveness of mini-dose heparin in preventing deep venous thrombosis or pulmonary emboli, it was believed that the method could be used safely and without fear of increased intracranial or intraspinal bleeding for neurosurgical patients.


Prognosis of seventh nerve palsy following removal of a large acoustic tumors.

Before the advent of microsurgery for acoustic tumors, it was accepted that the majority of seventh nerves would be lost during the removal of large tumors. It is now possible to preserve these attenuated seventh nerves, even with very large tumors. Postoperative facial palsy may be present even with an anatomically intact seventh nerve, but our experience has demonstrated that recovery will ultimately occur. Eight of our nin patients with this situation have regained facial function, although in some the first clinical evidence of recovery did not occur for 1 year.


Cerebral perfusion, vascular spasm, and outcome in patients with ruptured intracranial aneurysms.

In a retrospective study of 44 patients with verified ruptured intracranial aneurysms, the results of radionuclide cerebral perfusion scintigraphy (dynamic brain scanning) and the presence or absence of arteriographic spasm were correlated with the clinical outcome. The data indicated that patients with normal dynamic scans had a better outcome as a group and following intracranial surgery than those in whom perfusion was reduced. Patients with normal perfusion had a higher incidence of preoperative rebleeding from their aneurysms, while patients with reduced perfusion had a higher incidence of infarction, especially after intracranial surgery. There was no correlation between the presence or absence of arteriographic spasm and the results of the dynamic scans, and nor correlation between the presence of absence of spasm and the outcome of the group as a whole. However, in some individual cases with severe spasm, reduced perfusion on the dynamic scan and a poor outcome were noted. It was concluded that the results of the dynamic scan correlated better with eventual patient outcome than the presence or absence of arteriographic spasm. It is therefore suggested that patients in Grades I and II with normal dynamic scans be operated on promptly to prevent rebleeding, and that surgery in patients in Grades I and II with abnormal dynamic scans be delayed until the dynamic scan returns to normal.


Computerized tomography and surgical treatment in intracranial suppuration. Report of 30 consecutive unselected cases of brain abscess and subdural empyema.

The authors report their experience with 30 cases of intracranial suppuration: 23 with brain abscess and seven with subdural empyema. All of the cases were diagnosed by means of computerized tomography and enhancement with intravenous contrast material. Most of the patients were treated by single or repeated aspiration through burr holes.


Ventriculolymphatic shunt.

The authors report the cases of 16 adult patients who underwent ventriculolymphatic shunt procedures with apparent good results. The follow-up period is from 2 to 12 years. The anatomy of the terminal portion of the thoracic duct studied in 51 patients undergoing sympathectomy of the lower cervical-upper thoracic ganglionic chain is reported. The operative technique of the ventriculothoracic duct shunting procedure is described, and a general review of the function of the shunt as compared with that of ventriculoatrial shunts is presented.


Syringomyelia following lumboureteral shunting for communicating hydrocephalus. Report of three cases.

Three patients are described in whom syringomyelia was identified long after the treatment of communicating hydrocephalus by a lumboureteral shunt. The reason for syrinx formation in these cases could not be determined. In two there was either autopsy-proven or presumed evidence for arachnoiditis, and in the third patient the symptoms of syringomyelia were acutely aggravated by temporary obstruction of shunt. The development of a pressure drop from the intracranial compartment to the spinal compartment with crowding at the foramen magnum is also a suggested mechanism.


Effects od dietary protein, fat and energy on blood hemoglobin and hematocrit in the rat.

Twenty-eight-day old male Sprague-Dawley rats were fed diets containing varying levels of protein, fat and energy for 8 weeks and were killed. Blood hemoglobin and hematocrit measured at the time of killing increased progressively with increases in the level of dietary protein up to 50% protein. The Mean Corpuscular Hemoglobin Concentration (MCHC; hemoglobin concentration in g/100 ml red blood corpuscles) reached a plateau in rats fed diets containing 15% protein or more. Rats consuming low (5%) and high (21.1%) fat diets had lower hemoglobin concentration and hematocrit than rats fed the diets with intermediate fat content (11.9%); the level of dietary fat had no effect on the MCHC. Rats fed restricted amounts of diet had similar hemoglobin concentration to rats fed the same diet ad libitum; however the restricted rats had a lower hematocrit and hence a relative elevation of the MCHC.


Nutritional availability of spray dried lard water protein.

Four growth trials were conducted with rats and chicks to investigate the nutritional value of Spray Dried Lard Water (SDLW--a by-product from the rendering process of animal lard) as a source of protein in a semipurified diet. Weanling rats lost weight when fed a diet containing 10% of SDLW as sole source of protein. Responses of rats to amino acid(s) supplementation indicated tryptophan as the first-limiting amino acid, then threonine, methionine and lysine. One-week-old chicks fed diets containing SDLW to provide 20% crude protein responded to dietary amino acid supplementation. The results suggested that the limiting amino acid sequence of spray dried lard water for chicks was methionine, tryptophan, threonine and lysine, respectively. Results from this study also showed that biological availability of the amino acids in SDLW protein was rather low.


Influence of prolonged fasting in the dog on glucose turnover and blood metabolites.

Glucose turnover and blood metabolites were measured in eight adult female beagles in the fed state, at 1 day of fasting, and at 7, 14, and 21 days of fasting. Glucose utilization decreased significantly from 1 to 7 days of fasting, but remained constant from 7 to 21 days, while blood ketones and plasma free fatty acids rose significantly during the same period. Plasma alanine, serine, and glycine fell with fasting, with the greatest decrease in alanine levels occurring between 7 to 14 days. Plasma branched chain amino acids rose significantly with fasting. It was concluded that the shifts in plasma metabolites and decreased glucose utilization could be indicative of decreased energy demands of the fasting dogs and/or a shift in substrate utilization with progressive fasting.


Serum and duodenal alkaline phosphatase levels in fed and fasted magnesium deficient rats.

Rats depleted of magnesium for 13 days were killed after 18 to 20 hours of fasting or 2 hours after consumption of a standard-sized meal. Serum and duodenal alkaline phosphatase (AP) were reduced in fasted magnesium depleted rats compared to pair-fed and ad libitum-fed controls. With refeeding, serum alkaline phosphatase levels rose significantly in all groups, but the levels in refed Mg deficient rats remained below serum levels of fasted control rats. Inhibition of AP activity with L-phenylalanine and urea suggested that the differences in AP levels of fasted and fed rats were mainly due to enzymes of intestinal origin. Intestinal AP levels increased after feeding in all groups, but were proportionately greatest in Mg depleted rats. The pattern of serum and duodenal AP in fed and fasted rats and the results of polyacrylamide disc gel electrophoresis (PADGE) in duodenal AP extracts suggest that Mg depletion alters the release of AP into the blood that normally occurs in response to feeding.


Effects of diet composition on serum levels of insulin, thyroxine, triiodothyronine, growth hormone, and corticosterone in rats.

These studies were designed to determine the effects of diet composition on serum insulin, triiodothyronine, thyroxine, growth hormone, and corticosterone and to correlate these hormones with feed intake, body weight, and adipose tissue weight in rats. Experimental diets were fed for a period of 4 weeks. The experimental dietary groups were as follows: high starch (HST), high glucose (HG), high sucrose (HSU), high protein (HP), high saturated fat (HFS), and higher unsaturated fat (HFU). Serum glucose concentrations were not significantly different among any of the groups. The HST, HSU and HG diets produced the highest serum insulin. Serum thyroid hormone levels were highest in rats fed high fat diets. No significant differences in serum growth hormone or corticosterone levels were noted among the dietary groups. There was a tendency for rats fed a high protein diet to have higher concentration of corticosterone. However, there were no significant differences detected. There was a significant negative correlation between serum corticosterone and ovarian adipose tissue weight. It is concluded from these studies that these types of dietary manipulation have a significant effect on endocrine status and body fat deposition.


Effects of oxalic acid on availability of zinc from spinach leaves and zinc sulfate to rats.

Some effects of dietary oxalic acid on availability of zinc from organic and inorganic sources were assessed. Male rats fed zinc-deficient diets with and without added sodium oxalate were orally dosed once with either 65Zn-labeled spinach leaves or 65Zn-labeled zinc sulfate. Spinach plants (Spinacia oleracea, var. "Winter Bloomsdale") were grown in 65Zn-labeled nutrient solutions that contained 0.033, 0.131 or 0.262 ppm zinc. Increasing zinc supply to the plants increased zinc concentration in the leaves. Oxalic acid content in all leaves was about 7% dry weight. Dietary oxalate enhanced the availability of 65Zn from zinc sulfate, but had no effect on absorption and retention of 65Zn from spinach leaves. Regardless of dietary oxalate levels, absorption and retention of 65Zn was greater from spinach leaves than from zinc sulfate. We concluded that endogenous zinc in spinach leaves was readily available to zinc-deficient rats, and that dietary oxalate was not deleterious to zinc availability.


Protein intake, uric acid metabolism and protein efficiency ratio in growing chicks.

Changes in uric acid metabolism in chicks resulting from alterations in dietary protein intake have been correlated with dietary protein quality. Plasma uric acid levels, total uric acid excretion and protein efficiency ratio were measured in growing chicks fed diets containing 11%, 20%, 43% and 80% protein. A second degree polynomial with a coefficient of determination of 93% best described the relationship between dietary protein intake and total uric acid output. A second degree polynomial with a coefficient of determination of 58% best described the relationship between protein intake and dietary protein quality as measured by the protein efficiency ratio method. Plasma uric acid level was correlated, positively and linearly, with dietary protein intake and had a coefficient of determination of 42%. An integration of these relationships with purine biosynthesis and reutilization would enhance our knowledge of the control of uric acid production in the chick and possibly in human gout. The data demonstrate that total uric acid excretion and uric acid concentration in excreta may represent very useful methods of measuring dietary protein quality in the chick. The data also demonstrate that dietary protein level markedly affects uric acid production.


Studies on the synthesis and metabolism of zinc-thionein in rats.

The objectives of this investigation were to study the role of zinc-thionein in the metabolism of excessive amounts of zinc and the re-utilization of zinc bound to this protein. Rats were injected ip with 5 mg Zn/kg body weight as zinc chloride for 5 days to induce the synthesis of zinc-thionein. Proteins with molecular weight of 10,000 with high affinity for zinc were synthesized in rat liver and intestine. These proteins were heat stable. Large scale isolation of this protein from rat liver was achieved by a simple method consisting of a heating step and sephadex gel fractionation. Intravenous injection of isolated 65Zn-thionein to rats resulted in similar organ distribution of zinc as that after 65ZnCL2 injection. Gel filtration experiments with liver supernatant from rats injected with 65Zn-thionein showed that a major portion of 65Zn was transfered to other protein fractions and was re-ultilized similar to inorganic salts of zinc. Morphological studies showed no toxic effects after injection of zinc-thionein. These results show that zinc-thionein is metabolically active and non-toxic.


Effects of protein deficiency, pair-feeding, or diet supplementation on maternal, fetal and placental growth in rats.

The effects of feeding, throughout gestation, a diet deficient in protein, of pair-feeding, and of supplementing the deficient diet late in gestation on maternal body weight and weights of the products of conception were investigated in the rat. Protein deprivation resulted in net loss of maternal body weight, smaller and thinner placentas with decreased DNA content and placental labyrinth size, reduced uterine tissue weight, and smaller fetuses with retarded bone development. Pair-feeding caused a less severe reduction in maternal, uterine, placental, and fetal weights. Placentas from pair-fed dams had normal cell numbers with reduced cell size. Diet supplementation late in gestation resulted in increased net and total maternal body weight and uterine, placental, and fetal fetal weights, and an apparent partial recovery in fetal bone development. Placental cell size also increased significantly. The results suggest that placental and uterine development in protein-deficient dams is not the limiting factor in fetal development. Availability of protein may be the primary limiting factor, and energy deficit may play a secondary role.


Effects of selenium and vitamin E deficiencies in lambs on hepatic microsomal hemoproteins and mitochondrial respiration.

Microsomal hemoprotein levels and delta-amino levulinic acid dehydrase activity were determined in livers and rate of oxygen uptake, ADP:O ratios, and respiration control index were determined on mitochondria from muscle, liver, and heart of normal and white muscle diseased (WMD) lambs. WMD lambs were produced by feeding their dams either low selenium purified or alfalfa hay diets. Vitamin E and/or selenium was injected in a 2 x 2 factorial treatment in the ewes fed purified diets. Hepatic microsomal cytochrome P 450 levels and total heme content were significantly lower in WMD lambs. Cytochrome b5 content was significantly lower in lambs on the -E-Se or -E + Se treatments than those on the +E--Se treatment, but the cytochrome b5 content was not different between WMD and normal lambs from ewes fed the hay diet. No differences were found in hepatic delta-amino levulinic acid dehydrase activity, or in the rate of oxygen uptake, ADP:O ratios or respiratory control index between mitochondria from normal and WMD lamb tissue on any of the treatments.


Audiometric configurations of drop forge hammermen and helpers.

A study of 99 intensively noise exposed drop forge hammermen and helpers was conducted. The results of this study revealed drop forge noise induced audiometric threshold configurations which are different than those associated with most types of steady state noise exposure.


Physiological profile of professional fire fighters.

This investigation assessed the physical characteristics, functional capacities, and body composition of 45 professional fire fighters, aged 23 through 49 years. Maximum oxygen uptake (VO2), Recovery Oxygen Uptake, arm and leg strength, all showed a negative linear relationship with age. On the other hand, percent body fat increased with age from 18% to 21%. Hand grip strength did not decline significantly as the grip strength values remained fairly constant for all of the fire fighters. Most of the data collected were considered to be within the normal range of the sedentary North American population. It was concluded from these data that professional fire fighters might well benefit from a training program designed to develop and maintain a higher level of personal fitness.


Scanning electron microscopy of integumental surfaces of Schistosoma intercalatum.

Scanning electron microscopy was employed to study critical point dried Schistosoma intercalatum adults at 120 to 6,000 X magnifications. Well-developed integrumental elevations, or bosses, with variable spination account for the roughness of the male schistosome. The female is relatively smooth even though it possesses minute spines on the posterior part of the body. SEM reveals that the gynecophoral canal of the male, especially the presence of a gynecophoral fold, provides an effective means for clasping the female when in copula.


Scanning electron microscope observations on adult Schistosoma japonicum.

The integumental surfaces of critical point dried adult Schistosoma japonicum were studied by scanning electron microscopy. There are no bosses or spines on the dorsal surface of the male, which is ridged and presents a spongy appearance. Many spines cover the inner surface of the oral sucker and extend to the pharyngeal opening. The oral sucker shows a rim with spines of variable size and sharpness inward and outward from the rim. The ventral sucker possesses many spines which are smaller than in the oral sucker. The lining of the gynecophoric canal is roughened by minute spines. The integument of the female is ridged and pitted and possesses fewer spines than in the oral sucker, the ventral sucker, and the gynecophoric canal of the male. Anterior to the acetabulum, the integumental surfaces are devoid of spines. However, in the other areas, spines are equally distributed except for the vicinity of the excretory pore.


Modification of the lung recovery assay for schistosomula and correlations with worm burdens in mice infected with Schistosoma mansoni.

The kinetics of recovery of schistosomula from the lungs of previously-unexposed CF1 mice were studied following infection with Schistosoma mansoni cercariae. Lung tissue fragments were incubated from 3 to 48 hr and the completeness of recovery of viable schistosomula was determined. The recovery of schistosomula from the lungs was shown to correlate closely with 7-week worm recoveries. With the additional incubation described, the lung recovery assay may provide a more defined indicator of protective immunity. Based on the data generated by these analyses, it is predicted that under these conditions schistosomula arrive in the lungs from 3 to 7 days after infection, and that they sojourn there for a 3-day period.


Life history and habitat analysis of the eye fluke Diplostomum spathaceum (trematoda: diplostomatidae) in Utah.

Diplostomum spathaceum which is widespread throughout Utah in desert, mountain valley, and high alpine lakes, causes a disease known as diplostomatosis or eye fluke disease. Snails (756) were examined and two species, Lymnaea stagnalis and L. palustris were positive for D. spathaceum. Examination of 838 fish, which included 19 species, revealed 10 species (Salmo trutta, Catostomus discobulus, Salmo clarki, Micropterus salmoides, Catostomus platyrhynchus, Salmo gairdneri, Gila atraria, Catostomus ardens, Salvelinus fontinalis, and Richardsonius balteatus) positive for metacercariae of D. spathaceum. The only avian hosts positive for adult Diplostomum were Larvus californicus and L. delawarensis.


Partial purification of fasciola hepatica antigen for the immunodiagnosis of fascioliasis in rats.

When F. hepatica adult worm antigen is fractionated with Sephadex G-200, four major peaks are obtained. The first peak, when used as antigen in counterelectrophoresis, reacts with the serum of normal rats as well as from rats infected with F. hepatica for 5 weeks or longer. The crest and descending portion of peak II and the third peak are nonreactive with normal rat serum, but highly reactive with the serum of rats with F. hepatica. In addition, F. hepatica antigens cross-reacting with S. mansoni adult worm antisera are absent in these fractions. It is suggested, then, that these fractions of F. hepatica adult worm antigen be utilized for the immunodiagnosis of fascioliasis by CEP. Optimum antigen concentration for this test has been determined to be approximately 1.80 mg/ml protein.


Experimental infection with Plasmodium chabaudi in rats. Observations on adaptation and the immune responses to infection.

Plasmodium chabaudi was adapted to rats after some initial refractoriness. Progressive adaptation was indicated by shortening of the prepatent period and increases in peak parasitemia with successive passages. Rats infected with parasites of early passages resisted the infection, and even splenectomized rats quickly recovered. However, the parasites appeared to become more virulent with successive passages and after the 45th passage, all adult rats inoculated with the parasite died with severe hemolytic anemia. After adaptation, infections of the rat strain appeared to stimulate resistance in mice that was more effective against challenge with parasites of the homologous strain than it was against challenge with mouse strain parasites. Rats recovered from P. chabaudi were highly resistant to the homologous strain of P. chabaudi, but they were no more resistant to Babesia radhaini than were normal rats. However, when the rat strain was used to immunize mice, they were as resistant to B. rodhaini as they were to mouse strain P. chabaudi. Serologic studies made on rats with acute infection indicated that anemia was associated with antibody to erythrocytes as well as with high parasitemia. The soluble serum antigen (SA) associated with malarial and babesial infections was not present and its antibody was not detected in serum of recovered rats. However, antibody to SA was detected in blood mice that had recovered from rat strain P. chabaudi infection. Thus acquired resistance to B. rodhaini appeared to have been associated with elaboration of SA.


Anantrum histocephalum sp. n. (cestoda: bothriocephalidae) from Synodus lucioceps (synodontidae) of Southern California.

Anantrum histocephalum sp. n. is described from Synodus lucioceps, California lizardfish. The larger worm size, mushroom-shaped scolex, vitelline follicle distribution, and larger eggs distinguish this species from A. tortum. The tapeworm was observed in 8.5% of 164 lizardfish from the coastal waters of Los Angeles County.


Tupaiataenia quentini gen. et sp. n. (anoplocephalidae: linstowiinae) and other tapeworms from the common tree shrew, Tupaia glis.

Three species of cestodes recovered from tree shrews, Tupaia glis, were identified as Sparganum sp., Hymenolepis diminuta, and Tupaiataenia quentini gen. et sp. n. The new genus is differentiated from Mathevotaenia, Markewitchitaenia and Atriotaenia by being craspedote, possessing a large seminal receptacle, the presence of a hermaphroditic canal leading into the genital atrium, and by having two opposable, muscular lappets on the anterior margin of each sucker.


A simple method of obtaining an enriched fraction of tegumental brush border from Hymenolepis diminuta.

A method for isolating an enriched preparation of tegumental brush border from the tapeworm, Hymenolepis diminuta, is described. Combining incubation of whole tapeworms in Krebs-Ringer/tris-maleate solution containing a hemolytic saponin, low shear-force agitation, and differential centrifugation, a pellet is obtained at 2,500 g which contains a significant concentration of surface brush border. The content of brush border in this fraction is identified by the presence of numerous microvilli, increased specific radioactivity after surface tagging with 3H-Concanavalin A, and relatively little mitochondrial contamination (succinic dehydrogenase). Based on morphological criteria, fractions sedimenting with greater force contain dense vesicles and mitochondria from the outer portion of the tegument.


Lipids from subcellular fractions of the tegument of Hymenolepis diminuta.

Lipids comprised 37% and 22.1%, respectively, of the day weights of brush border- and vesicle-rich fractions separated by differential centrifugation of isolated H. diminuta tegument. Neutral lipids of both fractions were rich in cholesterol, but also contained small amounts of glycerides, sterol esters, and (in brush borders) free fatty acids. Phosphatidyl ethanolamine was the most prevalent polar lipid in both fractions, and was particularly abundant (63.4% of total polar lipids) in vesicles; sphingomyelin, not previously reported from H. diminuta, was also present. Polar lipids of both tegumental fractions resembled each other but differed from whole worm polar lipids in fatty acid composition. Tegumental polar lipids contained lower levels of long-chain, polyunsaturated fatty acids than reported for corresponding lipids of whole worms.


Oncicola martini sp. n., and other archiacanthocephala of the Chaco Boreal, Paraguay.

Archiacanthocephalans are reported from mammals of Paraguay. Oncicola martini sp. n. is described from Felis geoffroyi. It is most similar to O. lamasi (Freitas et Costa 1964) comb. n., differing in having larger hooks, all except the smallest of which are barbed. Other species recorded are Oncicola oncicola from Felis geoffroyi (new host record), O. paracampanulata from Felis yagouaroundi, O. luehei from Nasua nasua, Oligacanthorhynchus microcephala from Didelphis albiventris, and O. tortuosa from Euphractus sexcinctus (new host and South American records).


The morphology and histochemistry of eggshell formation in Cephaluris coloradensis, a parasite of pikas.

Histochemical and histological studies of Cephaluris coloradensis (Nematoda: Oxyuridae) a parasite of pikas (Ochotonidae), show that in this species the eggs are each enclosed by three shells. The inner shell is chitin with an operculum at one end; the operculum is chemically distinct. The other two shells are lipoprotein. The inner lipoprotein shell is new, not previously reported in nematode species. It forms after the outer lipoprotein shell but beneath it, and is believed to be a product of the egg. The new layer encircles part of the embryo. A thin mucoprotein cementing substance binds the inner lipoprotein shell to the chitinous shell. A thin outermost mucoprotein layer formed from secretions of the uterus covers the eggshell.


In vitro cultivation of Ostertagia ostertagi, the medium stomach worm of cattle. I. Development from infective larvae to egg-laying adults.

When a 70-min exsheathing process and two-step roller culture system were used, infective larvae of Ostertagia ostertagi developed in large numbers to mature adult males and females in 28 and 29 days, respectively. Females laid fertile eggs in the 2- to 16-cell stages from day 34 on. Some of the expelled eggs developed to the morula stage, in the culture fluid, by day 52. Yields of mature adults and eggs were best when cultures were started with 100,000 larvae in 100 ml of medium. The optimal culture system produced from 20% to 35% mature adults, from days 28 through 52.


Labial sense organs of the nematode, Heterakis gallinarum.

The labial sense organs of Heterakis gallinarum (Schrank 1788) were examined by scanning and transmission electron microscopy. Two large doublet papillae are visible externally on the dorsal lip while a single doublet papilla, a short peglike ventrolateral papilla, and the opening of the amphid are visible on each subventral lip. Internal anatomy of these papillae indicates that the doublet papillae are probably pressure receptors while the ventrolateral papillae may be combined mechano- and chemoreceptors. Amphids resemble the structure of amphids of several previously studied nematodes. Six internal labial receptors, two at the inner edge of each lip, can be identified by transmission microscopy. They may be mechanoreceptors recording cuticular stresses during feeding. Each sense organ is associated with a complexly folded system of membranes delimiting extracellular space continuous with space surrounding the dendritic process of the receptor.


Brugia timori sp. n. (nematoda: filarioidea) from Flores Island, Indonesia.

Brugia timori sp. n. from experimentally-infected Mongolian jirds (Meriones unguiculatus) is described. The adult male differs from other Brugia species, except Brugia malayi, in having a spicular ratio of 3 : 1; it differs from B. malayi in having greater numbers of subventral adanal papillae (up to 5 on each side) that are loosely spaced and irregularly positioned about the cloaca, a greater diameter of the capitulum of the left spicule, greater lengths of the proximal- and midsections of the left spicule, and a greater length of the proximal section of the right spicule. The adult female has an ovejector of greater length and width than that of B. malayi. Microfilariae in the blood of persons from whom the parasite lines of this study originated were typical of the Timor type, having a greater total body length than other Brugia spp., a length to width cephalic space ratio of about 3 : 1, and a sheath which did not stain when processed in the usual manner with Giemsa.


Haemaphysalis (allophysalis) danieli, sp. n. (ixodoidea: ixodidae), female and tentatively associated immature stages from high mountains of northern Pakistan and Afghanistan.

Haemaphysalis (Allophysalis) danieli sp. n. is described from a female taken from alpine vegetation in Swat, Pakistan. Fifty-one nymphal and larval ticks tentatively associated with this taxon are from hamsters, field mice, voles, and marmots (Rodentia), Cricetulus migratorius, Apodemus flavicollis, alticola roylei, and Marmota caudata, and from pikas (Lagomorpha), Ochotona roylei, in Gilgit and Hazara districts of Pakistan and in Badakhashan Province of Afghanistan. Collecting localities are in the western Himalayan mountain complex between 2,310 and 4,000 m altitude and between 35degrees08' and 36degrees23' N and 71degrees51' and 74degrees02' E. This species is most closely related to the mountain-inhabiting H. (A9Y pospelovashtromae Hoogstraal of southern USSR and Mongolia and H. (A.) garhwalensis Dhanda and Bhat of northern India and Nepal.


Life cycle of the tick Rhipicephalus evertsi evertsi neumann (acarina: ixodidae) under laboratory conditions.

The preoviposition period of the tick Rhipicephalus evertsi Neumann maintained under laboratory conditions at 26 C was 6.1 +/- 0.38 days. The average number of eggs produced during the oviposition period was 10,400 +/- 397 (max. 13.307, min. 7,558). The greatest daily egg production was recorded on the 3rd day (1.107 eggs/female). The incubation period of eggs at 26 C was 24.8 +/- 1.37 and the feeding time of the larvae and nymphs (a two-host tick) was 17.2 +/- 0.14 days at 26 C. This tick represents the two-host type of cycle and the percentage of larvae, pharate nymphs, and nymphs on the host at various intervals after attachment was recorded. The changes in the weight of the immature stages during the feeding period was examined daily. Nymphs which produce males were lighter in weight (10.3 +/- 0.28 mg), than those which produce females (15.6 +/- 0.33) and males emerge (13.7 +/- 0.10 days of premolting period) before females (14.1 +/- 0.11 days).


Is stimulus recognition a necessary condition for the occurrence of exposure effects?

Many theories of exposure effects involve the operation of psychological processes that depend on some form of stimulus recognition. Two experiments investigated the role of stimulus recognition in the mere exposure phenomenon. Female subjects viewed novel stimuli at various exposure frequencies, then measures of stimulul recognition and effect were obtained. In each experiment, a significant and positive relationship was found between stimulus exposure and affect, even when the effects of stimulus recognition were held constant. Thus, stimulus recognition was not a necessary condition for the occurrence of the observed exposure effects. The results suggest that the relationship between stimulus exposure and affect does not depend on the operation of higher order cognitive processes, at least to the extent that such processes are themselves dependent upon stimulus recognition.


Behavior change following self-confrontation: a test of the value-mediation hypothesis.

This study presents a reanalysis of data from Rokeach's self-confrontation experiments using path analytic techniques. Contrary to Rokeach's interpretations, findings indicate that behavior changes  following self-confrontation are not primarily mediated through changes in value priorities. Rather, the available data suggest that the self-confrontation process involves the resolution of inconsistencies between behaviors and self-conceptions that are revelaed during the treatment session. The authors interpret these findings within the framework of Rokeach's general theory of self-disatisfaction and cognitive-behavioral change. Suggestions for future directions in self-confrontation research are offered.


Nonverbal communication of affect in preschool in children: relationships with personality and skin conductance.

A slide-viewing paradigm measuring the tendency to communicate accurate nonverbal messages via spontaneous facial expressions and gestures was applied to 13 male and 11 female preschoolers (aged 4-6 years). The children watched 16 emotionally loaded color slides while, unknown to them, their mothers viewed their reactions via television. The children's skin conductance (SC) was monitored during the experiment, and they had been rated by two teachers on a new scale of affect expression developed from Jones' externalizer/internalizer distinction. High communication accuracy was associated with low SC responding. Rated expressiveness was associated with high communication accuracy and low SC responding. Sex differences appeared in the pattern of relations between the affect expression scale and the measures of communication accuracy and SC response.


Effectiveness of counteraggression strategies in reducing interactive aggression by males.

Studies on techniques of reducing aggression have typically examined passive, matching, and punitive strategies of counteraggression and have been remarkably inconsistent in their findings. This research was designed to resolve the contradictory results by reconceptuallzing the strategies in terms of counteraggression/aggression (cA/A) ratios. We predicted that the norm of reciprocity and the tendency to exploit weakness would make a cA/A ratio of less than but close to 1.0 (matching) most effective in reducing aggression. Ten cA/A ratios were used. One hundred male subjects set punishment level set by their opponent (a confederate) on 25 trials, and, on 13 losing trials, received punishment. The most effective cA/A ratios for reducing aggression were the lowest ones. Lower cA/A ratios reduced aggression and ratios greater than 1.0 increased aggresion. Contrary to the results of previous studies, the matching strategy was ineffective in reducing aggresion.


Hexobarbital pharmacokinetics in rats after ligation of the common bile duct.

Rats, with and without bile duct ligation (BDL), were injected with hexobarbital (i.p. and i.v.) and blood concentrations measured as a function of time. Analysis of these curves using a single-compartment model showed that BDL altered hexobarbital pharmacokinetics in a manner dependent upon the duration of BDL and the route of administration of hexobarbital. Clearance from the blood and the rate constant for elimination (K) were reduced after 72-hour BDL but not after 12-hour BDL. The absorption of hexobarbital after intraperitoneal injection was slowed by 12- and 72- hour BDL. Seventy-two-hour BDL also increased the volume of distribution of hexobarbital but only when the drug was administered intraperitoneally. These data are consistent with previously reported data showing impairment of hepatic microsomal drug metabolism after 72-hour BDL, but not after 12-hour BDL. We also confirmed earlier speculations that BDL decreased the absorption of intraperitoneally-administered hexobarbital, although this does not appear to be a significant factor in prolonging hexobarbital sleeping time.


Mechanism of action of anticoagulants: correlation between the inhibition of prothrombin synthesis and the regeneration of vitamin K1 from vitamin K1 epoxide.

It has been proposed that coumarin and indandione anticoagulants inhibit clotting protein synthesis by preventing the regeneration of vitamin K1 from its 2,3-epoxide metabolic. To test this hypothesis, the effects of nine coumarin and indandiones on prothrombin synthesis and the conversion of vitamin K1 epoxide to vitamin K1 were measured. There was a good correlation between the inhibition of prothrombin synthesis and the epoxide-K1 conversion both in vivo and in vitro. Diphenadione (2-diphenyl acetyl-1,3-indandione) caused a delayed inhibition of prothrombin synthesis which correlated with a delayed inhibition of the epoxide-K1 conversion in vivo. These results provide strong evidence for the proposed mechanism of action of coumarin and indandione anticoagulants.


Studies in rats on the mechanism by which 6-mercaptopurine inhibits the anticoagulant effect of warfarin.

The observation in man that 6-mercaptopurine (6-MP) decreases the anticoagulant effect of warfarin could be simulated in male Wistar Lewis rats. This permitted a detailed study in animals on the mechanism of this drug interaction. It was found that 6-MP treatment (5 mg/kg at 12-hour dose intervals) neither affects the distribution nor increases the elimination rate of 14C-warfarin. The degradation rate of prothrombin complex activity (determined after blocking the synthesis of prothrombin complex activity by 15 mg/kg of warfarin sodium) was also not inhibited by 6-MP. When added to rat plasma in vitro, 6-MP had no effect on prothrombin times. It was evident, however, that 6-MP treatment produces a significant shortening of the prothrombin times of nonanticoagulated animals. This effect was completely reversible a few days after discontinuance of 6-MP treatment. Analysis of the activity of clotting factors II, V, VII, VIII, and X by one-stage assays using human deficient substrate plasma revealed that the increase in prothrombin complex activity during 6-MP treatment is mainly due to an increase in factor II activity. From these experiments it appears that 6-MP increases the synthesis and/or activation of prothrombin and thereby decreases the response to oral anticoagulant drugs.


Immunosuppressive effects of 8,9-epoxyhexahydrocannabinol (EHHC).

8,9-Epoxyhexahydrocannabinol (EHHC)-treated mice showed an inhibition of both humoral and cell-mediated immunity. The hemolytic plaque forming assay was employed to determine both the IgM and IgG antibody response. The effect of EHHC on IgM antibody production was measured in BDG1 male mice given X 10(8) sheep erythrocytes i.p. followed 24 and 48 hours later by i.p. injections of EHHC. EHHC produced a dose-dependent inhibition of plaque forming cells (PFC)/10(6) spleen cells and PFC/spleen on days 3, 4 and 5 after antigen administration. On day 4 the ED50 for PFC/10(6) spleen cells and PFC/spleen was 28 and 18 mg/kg, respectively. Peak response to IgG antibody production was observed on day 9. EHHC (100 mg/kg) administered i.p. 48 hours after antigen produced a 58 and 46% suppression of PFC/10(6) leucocyte on days 7 and 9, respectively. CDF1 male mice received 100 microng of Cornybacterium parvum in the left footpad. Two days after sensitization, EHHC was administered in doses of 0.75 to 50 mg/kg i.p. A challenge dose of 100 microng of Cornybacterium parvum was injected into the right footpad on day 6 and footpad swelling was measured 24 hours later by mercury displacement. EHHC at a dose of 0.78 mg/kg produced a 95% inhibition of the delayed-type hypersensitivity response. These studies showed that EHHC inhibits both the humoral and cellular arm of the immune response.


Miosis and fluctuation in the rabbit pupil: effects of morphine and naloxone.

In the unanesthetized rabbit, morphine (12-16 mg/kg i.v.) produced a miosis that was not sustained. The response to the narcotic was a pupillary constriction that became maximal within 2 minutes following i.v. administration, after which time the pupil size fluctuated appreciably. The magnitude of the fluctuation, typically as high as 40% of control diameter, was much larger than can be attributed to "noise." The fluctuations occurred within a frequency of approximately 0.5 to 2/min. The miosis and subsequent fluctuation seen with 12 and 16 mg/kg of morphine was blocked by naloxone (0.5 mg/kg i.v.), but 128 mg/kg of morphine overcame the block. Cumulative dose-response curves for morphine and for morphine after naloxone yielded the value pA2=6.8 which is in agreement with the values obtained using other effects and species. Administration of morphine after exposure to high intensity light produced less miosis than that seen under normal illumination.


Antiseizure activity of gamma-acetylenic gamma-aminobutyric acid: a catalytic irreversible inhibitor of gamma-aminobutyric acid transaminase.

gamma-Acetylenic gamma-aminobutyric acid (gamma-acetylenic GABA) produces several-fold sustained elevations of brain GABA concentrations when administered intraperitoneally to mice. It protects mice against seizures induced by audiogenic stimuli, electroshock, thiosemicarbazide, isoniazid and strychnine. The duration and degree of audiogenic seizure protection appears to correlate with elevations in whole brain GABA levels. gamma-Acetylenic GABA does not protect against seizures induced by pentylenetetrazol or picrotoxin even at doses that increase brain GABA concentrations approximately 6-fold. This differential antiseizure activity suggests that the GABA system may play a role in some, but not all experimentally produced seizures.


Induction of membrane alterations by norepinephrine: studies with macrophages and phospholipids monolayers.

Norepinephrine (8 mM) produced a rapid and readily reversible rounding and vacuolation in mouse peritoneal macrophages. The rapid onset and offset of these changes suggested something other than classical pinocytosis as a mechanism. The morphological changes were inhibited by cytochalasin B but not by propranolol. Norepinephrine lowered the contact angle between a macrophage monolayer and a sessile drop of saline. This indication of increased membrane hydrophilicity is consistent with an increase in membrane surface pressure. Norepinephrine had no effect on neutral phospholipid (phosphatidylcholine) monolayers but expanded acidic phospholipid (phosphatidylserine) monolayers over a wide range of surface pressures (15-40 dynes/cm). Based on these observations, it is suggested that norepinephrine may produce the morphological changes by expanding the macrophage membrane to the point of membrane buckling and/or by a viscotropic stimulation of membrane enzymes which, in turn, activate microfilaments.


Accumulation of norepinephrine by macrophages and relationships to known uptake processes.

Incubation of mouse peritoneal macrophages with l-[3H]norepinephrine resulted in an apparent multiphasic accumulation of the catecholamine by the cells. Low temperature did and iodoacetate did not inhibit uptake. Part of the accumulation followed saturation kinetics; cocaine, metanephrine and phenoxybenzamine did not inhibit the observed uptake. On this basis, it was concluded that the uptake process or combination of processes could not be classified solely as uptake1, uptake2 or simple diffusion However, similarities between norepinephrine accumulation by macrophages and that by other extraneuronal tissues do exist. This, along with previous morphological data, suggests that the macrophage uptake may typify a component of extraneuronal accumulation of norepinephrine and that this component may, in part, result from a nonspecific membrane perturbation by norepinephrine.


Antimuscarinic and noncompetitive antagonist properties of dicyclomine hydrochloride in isolated human and rabbit bladder muscle.

In isolated strips of bladder neck (prostatic capsule) and detrusor of rabbit and man, dicyclomine had minimal effect on the resting tension. Competitive antimuscarinic activity against carbachol could be demonstrated at doses of dicyclomine less than or equal to 1 X 10(-6) M, whereas at higher doses a noncompetitive action against both carbachol and potassium was observed. The ratio of dissociation constants relating to the noncompetitive and competitive actions, respectively, was about 1200, approximately 100 times higher than that previously reported in ileum. Dicyclomine was only about 1/30 as potent as atropine in competitive antimuscarinic activity. Dicyclomine hydrochloride may be useful in the clinical management of "uninhibited bladder."


Effects of acetylcholine on potassium movements in the guinea-pig sinus node.

Factors influencing the effect of acetylcholine (ACh) on potassium movements in the sinus node have been studied using tracer potassium (42K) and a microelectrode technique. The following results were obtained. ACh has qualitatively different effects on 42K uptake depending upon concentration, i.e., small concentrations (approximately equal to 10(-9) M) of ACh may decrease and larger concentrations (greater than or equal to 10(-7) M) increase 42K uptake. The ACh induced increase in 42K uptake is slightly but significantly greater when the rate of discharge is maintained constant by electrical drive than when the rate is slowed by ACh as quantitated by transmembrane recordings. In the presence of atropine, the ACh-induced increase in 42K uptake is abolished and replaced by a small but consistent decrease. Blockage by nicotine enhances the ACh-induced increase in 42K uptake and blockade by d-tubocurarine diminishes it. The effect of ACh on 42K uptake is greater in high (5.4 mM) than in low (0.54 mM) [Ca]0. These results suggest the conclusion that ACh acts upon a muscarinic recpetor to increase and on a nicotinic receptor to decrease potassium uptake. The net effect depends upon the concentration of ACh. The action of ACh on potassium uptake is modulated by [Ca]0.


Vasodilation due to urokinase in the canine femoral circulation.

Based upon clinical observations, we hypothesize that the plasminogen activator urokinase is vasoactive in addition to being fibrinolytic and thrombolytic. The effects of intra-arterial injections and infusions of urokinase were investigated in the canine femoral circulation. Injections of human urine urokinase increased femoral artery blood flow in a dose-related fashion that was not significantly attenuated by beta adrenergic blockade, antihistamine treatment, heating, atropine treatment or kallikrein inactivation. The Ploug preparation of urine urokinase was somewhat more effective than the Abbott or Sterling-Winthrop preparations in  causing this dilation. Some nonspecific inhibition of the vasodilator responses was produced by inhibition of plasminogen activation with epsilon-aminocaproic acid. The continuous infusion of urokinase increased femoral arterial flow but there was some tendency to escape. Further experiments seem indicated to determine potential application of local urokinase in clinical conditions where vasodilation and fibrinolysis-thrombolysis might be of value.


Vasodilatation produced by apomorphine in the hindleg of the dog.

Apomorphine, injected into the dog femoral artery in doses of 0.6 microng or higher, produced a marked increase in femoral blood flow, without a change in blood pressure. No increase in flow was produced by comparable doses of dopamine or morphine. After sympathetic denervation or administration of phenoxybenzamine, the apomorphine vasodilatation was either abolished or greatly reduced. When the vascular tone in the denervated hindleg was restored by sympathetic nerve stimulation, the vasodilatory effect of apomorphine often re-established itself; this was not the cases when the vascular tone was restored by an infusion of noradrenaline. The apomorphine vasodilatation was not antagonized by propranolol or atropine. Mepyramine, in doses that antagonize histamine, often inhibited the apomorphine vasodilatation. Haloperidol, injected i.a., antagonized the apomorphine effect without changing the responses to isopropylnoradrenaline, acetylcholine, histamine and and nitroglycerin. Haloperidol blockade was overcome by increasing the dose of apomorphine. These results suggest that apomorphine dilates the femoral vasculature by an action on a "dopamine receptor." The possibility that the receptor is located on sympathetic nerve endings is discussed.


Mexrenoate potassium: a steroidal aldosterone antagonist and antihypertensive.

Mexrenoate potassium (SC-26714) is a water soluble salt of a steroidal hydroxy acid which has been shown to antagonize the sodium-retaining effects of aldosterone at oral dosages of 1 mg/kg and about 1.8 mg/kg in the dog and rat, respectively. Dose-related natriuretic responses, indexed as a reversal (increases) in the aldosterone-depressed urinary log Na/K ratio, indicated that mexrenoate was between 2.1 (dog) and 4.5 (rat) times as potent as spironolactone. Based on sodium output, in intact rats, mexrenoate was essentially inactive as a diuretic with an estimated potency of less than 0.4% that of hydrochlorothiazide. Diuretic potency was not indicative of antihypertensive potency. In dogs with established hypertension (Page model with the remaining kidney decapsulated and cellophane wrapped) both mexrenoate and spironolactone exhibited equivalent antihypertensive responses. An optimum oral dose of either compound was 5 mg/kg/day. Initial and maximum antihypertensive responses were observed on the 2nd and 5th days of treatment, respectively. Recovery to pretreatment hypertensive levels was observed 72 hours later. Mexrenoate shares with spironolactone the pharmacological characteristics of an aldosterone antagonist.


Nephrotoxicity of cephaloridine in newborn rabbits: role of the renal anionic transport system.

The nephrotoxicity of cephaloridine, cefazolin and mercuric chloride was studied in rabbits of various ages. Cephaloridine produced dose-related elevations in serum urea nitrogen, creatinine and renal tubular necrosis in adult and 30-day-old rabbits, only slight changes at 15 days of age and no effect in 5-day-old rabbits. Cefazolin also produced dose-related nephrotoxicity in adult rabbits but no effect in 15-day-old rabbits. Mercuric chloride administration resulted in similar nephrotoxicity in 5-, 15- and 30-day-old rabbits and adults. The development of susceptibility to cephaloridine nephrotoxicity paralleled the maturation of the renal anionic transport system as determined by the accumulation of p-aminohippurate by renal cortical slices in vitro. Substrate stimulation of the anionic transport system by p-aminohippurate or penicillin increased the nephrotoxicity of cephaloridine in between rabbits. The authors concluded that the lack of cephaloridine nephrotoxicity in newborn rabbits is due to the incomplete development of the renal anionic transport system.


Turbulence measurement by the pulse luminescence method using a nitrogen pulse laser.

In order to visualize and measure with ease the velocity distribution and diffusion of turbulent flow, the pulse luminescence method was investigated. Turbulence intensity was obtained from the turbulent diffusion patterns by Taylor's diffusion theory. Apparatus was developed for easier measurement. A nitrogen pulse laser was used for instantaneous, high-power excitation. With the use of a night vision scope a bright image was recorded by a TV camera and video tape recorder. The optimum concentration of LC-G1A luminescent particles was about 0-05% wt for the measurement. High fidelity of the particles as an indicator of the fluid velocity was confirmed. It was demonstrated that the turbulence intensity could be visualized and measured quantitatively by the pulse luminescence method.


Effects of steady-state plasma vasopressin levels on the distribution of intrarenal blood flow on electrolyte excretion.

1. In order to evaluate the effects of arginine vasopressin (AVP) on the distribution of intrarenal blood flow and on electrolyte excretion, steady-state plasma AVP levels (4-8, 19-1, 44-3, and 100-6 micro u./ml.) were produced in anaesthetized dogs, which were hydrated to minimize endogenous anti-diuretic hormone (ADH) release. 2. The urinary excretion of sodium and potassium increased without change in their filtered loads during AVP infusion. 3. Measurement by the 133xenon washout method revealed diphasic blood flow shifts, as a function of the plasma AVP level, between compartment 1 (outer cortex) and compartment 2 (inner cortex and outer medulla) without change in compartment 3 (inner medulla). 4. In a separate study, the radioactive microsphere (15 micronm) method was used with a plasma AVP levels of 19-8 micronu./ml. Blood flow (expressed as % flow/g tissue) decreased in the outer cortex and increased in the inner cortex. 5. Total renal blood flow did not change during infusion of AVP. However, the values measured by 133xenon were lower than those measured by the microsphere method. 6. There was agreement between these two independent methods that blood flow shifted from outer to inner cortex, with no change in total renal flow, at similar plasma AVP levels (19-1 and 19-8 micronu./ml.). The relationship of these intrarenal circulatory changes to the increased electrolyte excretion is discussed.


Relative capabilities of sarcoplasmic reticulum in fast and slow mammalian skeletal muscles.

1. The calcium uptake capabilities of the sarcoplasmic reticulum (SR) of the fat-twitch muscles extensor digitorum longus (EDL) and tibialis anterior (TA) of the rat and the extensor digitorum longus of the cat have been compared with the same capabilities of the slow-twitch soleus muscles of the rat and cat. 2. For the ra the Vmax values of sarcoplasmic reticulum from tibialis anterior, extensor digitorum longus and from soleus muscles were 50, 51, and 10 micronmole Ca2+/g per minute, respectively. 3. For the extensor digitorum longus and soleus muscles of the cat the Vmax values were 34 and 5-6 micronmole Ca2+/g per minute, respectively. 4. These data were compared with mechanical data as reported in the literature for the same muscles. The relative calcium uptake capabilities of sarcoplasmic reticulum from slow and fast muscles corresponded closely to the relative rates of relaxation of these muscles.


Some properties of the smooth muscle of mouse vas deferens.

1. Contractions of the mouse vas deferens in response to electrical stimulation differ form those recorded form the guinea-pig vas deferens in that they are abolished by tetrodotoxin. 2. Changes in membrane potentials were recorded form the smooth muscle of both preparations in response to stimulation with current pulses applied by an intracellular electrode and by alrge extracellular plate electrodes. 3. Both preparations behaved similarly in response to intracellular stimulation. Electrotonic potentials in response to extracellular current pulses spread in a longitudinal direction in the guinea-pig vas deferens in accordance with the cable-like properties of this preparation. In contrast, no longitudinal spread of eletrotonus was observed in the mouse vas deferens. 4. Responses to nerve stimulation differed in the two preparations. In the guinea-pig, single stimuli caused excitatory junction potentials (e.j.p.s) which gave rise to action potentials. Some cells from the mouse vas deferens showed similar e.j.p.s and action potentials, although the threshold for the initiation of action potentials was lower and more variable. 5. The majority of cells in the mouse vas deferens failed to show action potentials in response to a single stimuli even though the amplitude of e.j.p.s was from 35 to 40 mV. This was probably due to the large resting membrane potentials of these cells, as all-or-nothing action potentials could be evoked if successive e.j.p.s were allowed to sum with each other or if a depolarizing current pulse was applied at the peak of an e.j.p. 6. The nature of the response to nerve stimulation recorded from differnt cells in the mouse vas deferens could be correlated with the amplitude and time course of the response of the same cell to intracellular stimulation. 7. It is concluded that individual smooth muscle cells in both preparations are probably coupled electrically but that there are few, if any, low resistance pathways in the longitudinal direction in the mouse vas deferens.


The distribution of acetylcholine receptors on muscle fibres of regenerating salamander limbs.

1. Muscle fibres developing during limb regeneration were examined for responsiveness to acetylcholine (ACh) applied iontophoretically along the membrane. 2. Fibres which were uninnervated as well as those with non-transmitting synapses had high over-all sensitivities, with only minor variations along their length. 3. Functionally innervated fibres in which depolarization did not yet elicit action potentials had high over-all sensitivities, even when the synaptic potentials ahd amplitudes of 40-50 mV. In these the membrane in the vicinity of synapses tended to have sensitivities above the background level. 4. Upon the appearance of action potentials, several weeks after fibre innervation, the responsiveness to ACh began to decline in synapse free regions of the membrane. In mature muscle the sensitivity to ACh is restricted to sites of synaptic contact.


Biochemical approaches to problems of cellular patterning.

The expression of intracellular patterning is perhaps nowhere more impressive than in the arrangements of structural elements associated with the cell surface in protozoa. The view is proposed that biochemical studies of protozoan plasma membranes and associated surface structures represent important contributions of potential significance for the understanding of the perpetuation and expression of positional information at the intracellular level. Some recent work dealing with the isolation, identification, and metabolism of pellicular proteins in Tetrahymena is presented and discussed. Some integral membrane proteins have been identified by iodination and polyacrylamide gel electrophoresis. Labeling studies suggest heterogeneous turnover rates within the group of presently identified membrane proteins. High molecular weight proteins with some similarity to spectrin have been isolated from Tetrahymena epiplasm. It is suggested that the ciliate epiplasm is one example of membrane-associated, actomyosin-like systems found in a variety of cell types. The epiplasm may play a role in the positioning of surface-associated structures and in the control of cell shape.


Site and mode of adrenaline action on chloride transport across the rabbit corneal epithelium.

1. Membrane events accompanying adrenaline-stimulated Cl secretion by the isolated rabbit corneal epithelium were investigated with micro-electrodes. 2. Pulses of adrenaline (5 X 10(-10) M final concentration) delivered to either side of the epithelium produced a transient decrease in epithelial resistance occuring at the outer membrane of the squamous cell. This response was reversible and could be blocked completely by total Cl substitution with SO4. 3. Adrenaline generally produced a small transient increase in epithelial potential occuring also at the squamous cell outer membrane. Reversal potentials obtained for the adrenaline response were 45-1 mV for corneal potential and 22-8 mV for outer membrane. 4. Adrenaline always hyperpolarized epithelial potential when the tear side was bathed in Cl-free solution. Reversing the gradient (Cl-free on the stromal side) slowly and consistently changed the response to a depolarization which reached a steady level after 2 hr. 5. The reversal potential of the outer membrane for the adrenaline response was found to be a semilogarithmic function of the tear side Cl concentration over a broad range with a slope of 56 mV/decade. The reversal potential was zero at a tear side Cl concentration of 41-5 mM, which value may be taken to be representative of cell Cl concentration. 6. After abolishing the adrenaline response by perfusing both sides of the tissue with Cl-free solution, reintroduction of Cl to the stromal side led to a recovery of the epithelial potential response in the hyperpolarizing direction. The recovery of the response was inhibited by ouabain (10(-5) M). 7. The results supported the following model for the influence of adrenaline on anion transport in the epithelium: Cl is transported against an electrochemical potential gradient into the cells from the stromal side by an active process linked to Na-k activated ATPase. Normally a slight gradient exists from cells to tears favouring the passive outward diffusion of Cl. This latter process is enhanged by adrenaline, which increases cell cyclic AMP, in turn increasing the passive Cl permeability of the outer cellular membrane.


Eimeria dispersa and Eimeria gallopavonis: infectivity, survival, and development in primary chicken and turkey kidney cell cultures.

Eimeria dispersa (turkey strain) and Eimeria gallopavonis sporozoites were inoculated into primary cultures of chicken kidney (CK) and turkey kidney (TK) cells. Eimeria dispersa sporozoites were more infective in either cell type than those of E. gallopavonis: at 4 hr, the percentage of infection was 67-98 for E. dispersa but only 23-56 for E. gallopavonis. E. dispersa also survived better in culture: at 2 days, losses of E. dispersa in both cell types were only 4-19%, whereas losses of E. gallopavonis were 35-47% IN TK cells and 60-95% CK cells. However, E. gallopavonis developed further than E. dispersa. Location and increase in numbers of intracellular stages at 4 days indicated that E. dispersa proceeded through 2 schizogonic generations before development stopped.


The effects of heat and cobalt-60 gamma-radiation on excystation of the rat coccidium, Eimeria nieschulzi Dieben, 1924.

Sporulated oocysts of Eimeria nieschulzi Dieben, a rat coccidium, were exposed for 1 hr to Cobalt-60 gamma-radiation (15, 30, or 60k-rads), to heat (35, 40, or 45 C) , or to both concurrently (15, 30, OR 60 K-RADS AT 35 C) to compared the excystation capabilities of treated vs nontreated parasites. Intact treated oocysts appeared structurally unaltered when viewed with the light microscope. Excystation of sporozoites occured in all treated groups when their sporocysts were exposed to a trypsin-sodium taurocholate (TST) fluid, but after 150 min in TST the excystation rate was significantly lower than in nontreated sporocysts. Sporozoites which excysted from treated sporocysts were abnormal both in the excystation process and in their form and movement once outside the sporocysts.


Effect of age and sex on the acquisition of immunity to toxoplasmosis in cats.

The effects of age and sex of the cat on oocyst shedding, multiplication of Toxoplasma gondii in tissues of cats, and acquisition of immunity were investigated after oral inoculation of cats with Toxoplasma cysts. Twenty-five cats varying in age from 1 week to 39 months were killed 7-97 days after inoculation with T. gondii. Homogenates of brain, heart, mesenteric lymph nodes, retina, and blood from these cats were inoculated into mice to test for Toxoplasma infectivity. Toxoplasma was isolated more frequently and in higher titers in mice receiving inocula from cats of the youngest age group (1 week old). Toxoplasma gondii was isolated from tissues of only 2 of 21 cats older than 2 months (at the time of inoculation), although all of the animals shed oocysts within 1 week after ingesting the parasites. The number of oocysts shed varied among littermates of the same sex and between sexes. Generally, cats younger than 12 months shed more oocysts than older cats. The number of oocysts shed by older cats varied considerably; males generally shed more oocysts than the females. However, the numbers of cats examined were too small for statistical comparison. Nevertheless, the observations suggest that cats older than 12 months should not be used in experiments where numbers of oocysts shed is critical.


Effect of ethidium bromide on the oxidative metabolism and enzyme profiles of Crithidia fasciculata.

Changes in the metabolism of Crithidia fasciculata ATCC 11745 when grown in the presence of ethidium bromide were studied. Ethidium bromide-grown cells had decreased respiratory activity as measured by oxygen consumption. More than 50% of the organisms cultivated in a defined medium containing 1.0 mg/liter of ethidium bromide became dyskinetoplastic and had decreased activities of particulate succinate and NADH-linked dehydrogenases as well as of soluble isocitrate dehydrogenase. These cells also had increased activities of particulate alpha-glycerophosphate dehydrogenase, soluble alpha-glycerophosphate dehydrogenase, malic enzyme, hexokinase, and malate dehydrogenase. Ethidium bromide-grown cells had a lower level of ATP and contained less DNA than cells grown in its absence.


Gradionation: hypothesis for positioning and patterning.

The interaction of contiguous proteins is explored in microtubules, rosettes, and membranes based on the well established molecular phenomena of cooperativity and allosterism. It is proposed that conformational gradients in protein arrays cause the formation of gradions by nearest-neighbor interactions. Gradions are repeating functional molecular sequences that contain several conformational forms of one or more proteins, with the result that different reactive sites can exist in the same molecular architecture at any one time. Gradionators are small controlling molecules that may be microscopically visible as layers of linkages, but could alse be smaller. Some of the presently available supporting evidence and its functional implications are discussed, including the possibility that the raison d'etre for membrane-particle arrays is to enhance the regulation and amplification capabilities of cell systems.


Organization and control of microtubule pattern in centrohelidan heliozoa.

Comparative studies of axopodial microtubule pattern in 10 different centrohelidan Heliozoa belonging to the genera Acanthocystis, Raphidiophrys and Heterophrys suggest that 2 basic principles govern pattern formation in centrohelidan Heliozoa. While the larger "open" arrays with unspecified number of microtubules, e.g. in A. aculeata and R. ambigua, may result from self-linkage of additional microtubules around centroplast-nucleated "starter microtubules," the smaller "closed" arrays with specified microtubule number, e.g. in A. pectinata and H. marina, favor a template-driven linkage mechanism. The centroplast is a highly complex microtubule organizing center involved in the control of orientation, number, and diameter of the axonemes. Its shell may serve as a surface upon which the microtubule nucleating sites assemble, but how the precise positioning of these sites occurs is still open to debate. Some of the unsolved problems of microtubule pattern formation may be explained by the "linker nucleation hypothesis" which is an extension of the "gradion hypothesis" by Roth et al. It is shown how both the formation of closed arrays and the balanced lateral growth of open arrays may result from linker-induced microtubule nucleation.


Uterine proteins and the activation of embryos from mice during delayed implantation.

Ovariectomy-induced delay of implantation was used to study the role of the uterine environment in controlling implantation in mice. Labelling studies in vivo showed that uterine protein synthesis and secretion is maximal 2-5 h and 24-30 h after the oestradiol injection which initiates implantation. Embryos removed from uteri 5,12 or 30 h after oestradiol injection were able to transport and utilize precursors of nucleic acids and proteins in short-term cultures at the same rate as normal embryos, although "delayed" embryos had low levels of activity. These results suggest that "delayed" embryos are metabolically activated within 5 h of release from delay, perhaps because of the hormonally-induced changes in uterine proteins which occur at this time.


Oestrogen content of semen and the effect of exogenous oestradiol-17beta on the oestrogen and androgen concentration in semen and blood plasma of bulls.

The concentration (mean +/- S.E.M.) of oestrogen in semen (0-89 +/- 0-04 ng/ml) of bulls was 8-9-fold higher than in blood plasma (0-10 +/- 0-01 ng/ml) while the concentration of androgen in semen (1-15 +/- 0-26 ng/ml) was 2-7-fold lower than in blood plasma (3-21 +/- 0-47 ng/ml). This concentration of oestrogen in semen was not influenced by 0,1,3 or 5 false mounts or when ejaculations occurred at 2-min intervals. When 100 mg oestradiol-17beta were injected i.v. the oestrogen level in semen followed that in the plasma.


The association between basal body temperature, sexual swelling and urinary gonadal hormone levels in the menstrual cycle of the chimpanzee.

Basal body temperature (BBT) was measured continuously by radiotelemetry throughout 14 chimpanzee menstrual cycles and correlated with daily observations of the sexual skin swelling. A biphasic BBT shift from a pre-nadir mean of 36-12 degrees C to a post-nadir mean of 36-67 degrees C was observed in 12 cycles. The temperature nadir showed a close temporal relationship with detumescence of the sexual skin swelling (an early luteal event), but the rate of temperature rise after the nadir was variable. In 3 normal cycles studied, the temperature nadir occurred the day after a urinary oestrone peak, but there was no consistent temporal association between BBT rise and pregnanediol increment. Progesterone secretion is therefore probably not the sole determinant of the BBT shift; the changing oestrogen/progestin ratio may be the more important factor regulating body temperature during the luteal phase.


Changes in the protein content of mouse uterine flushings during normal pregnancy and delayed implantation, and after ovariectomy and oestradiol administration.

The protein content of the mouse uterine lumen increased significantly (P less than 0-001) on Day 4 of pregnancy, the day of implantation. This increase was associated with the presence of 14 serum and 22 non-serum proteins in the lumen; the major serum proteins were classed as high molecular weight slow alpha-globulins, while the dominant non-serum components consisted of slow and fast alpha-globulins, 6 prealbumins and a large quantity of proteinaceous material migrating near the origin of the gels. During experimental and lactational delayed implantation the protein levels were constantly low, transferrin, haemoglobin and albumin dominating the protein pattern. After administration of oestradiol-17beta, however, a biphasic uterine response was detected, significant increases in luminal protein concentration being observed within 12 h and again at 40-48 h after injection. The first phase of this response involved an influx of serum and non-serum proteins into the uterine lumen, most proteins migrating as high molecular weight slow alpha-globulins. The second phase involved an increase in the intensity of many non-serum components, the major proteins having Ra values of 0-06, 0-10 and 0-32. The qualitative, but not the quantitative, aspects of this response to oestradiol were identical in the absence of blastocysts.


Examination of the role of FSH in periovulatory events in the hamster.

The need for endogenous FSH in the periovulatory events such as oocyte maturation, ovulation, luteinization, maintenance of luteal function and follicular maturation was examined in the cyclic hamster. A specific antiserum to ovine FSH, shown to be free of antibodies to LH and to cross-react with FSH of the hamster, was used to neutralize endogenous FHS at various times. Administration of this antiserum during pro-oestrus did not affect oocyte maturation and ovulation, as judged by the normality of the ova to undergo fertilization and normal implantation. It also had no effect on the process of luteinization or on the maintenance of luteal function as indicated by the normal levels of plasma and luteal progesterone during pro-oestrus and oestrus during the cycle and in pregnancy. All these processes were, however, disrupted by administration of an antiserum to ovine LH, thereby demonstrating their dependence on endogenous LH. Although FSH antiserum given at pro-oestrus did not prevent the imminent ovulation, it blocked the ovulation occurring at oestrus of the next cycle. This antiserum was effective in preventing the ensuing ovulation when given at any other time of the cycle until the morning of pro-oestrus. It is concluded that, in the hamster, high levels of FSH during pro-oestrus and oestrus are required for initiating maturation of a new set of follicles which are dependent on the trophic support of FSH throughout the cycle until the morning of pro-oestrus. Such follicles then appear to need only LH for subsequent ovulatory and associated processes.


Studies on the binding of antibody against mouse lactate dehydrogenase (isoenzyme X) by preimplantation mouse embryos.

The binding of antibodies against LDH-X by preimplantation mouse embryos was studied to detect LDH-X from spermatozoa in embryos after fertilization. Incubation of preimplantation mouse embryos with rabbit anti-mouse-LDH-X-IgG and then with peroxidase-labelled goat anti-rabbit IgG revealed a strong peroxidase staining of the zona pellucida of normal fertilized and unfertilized 1-cell ova. However, the reaction was significantly weaker with both fertilized and unfertilized 1-cell ova from females induced to superovulate and normal and superovulated blastocysts. Pure antibody against mouse LDH-X was obtained by affinity chromatography of the rabbit anti-mouse LDH-X-IgG on pure mouse LDH-X covalently bound to sepharose. The pure antibody against mouse LDH-X reacted immunochemically identically to anti-mouse LDH-X-IgG, but it was not bound by any stage of preimplantation mouse embryos. The IgG fractions which had passed through the affinity column during the purification procedure and which did not contain any anti-LDH-X activity were bound by the zonae of preimplantation mouse embryos in the same manner as was unpurified anti-mouse LDH-X-IgG. Histochemical studies indicated LDH activity only in the embryo proper, but not on the zona pellucida. It is concluded that LDH-X is not present in preimplantation mouse embryos.


Effect of copper and platinum intrauterine devices on endometrial morphology and implantation in the rabbit.

The response of the rabbit endometrium to the copper IUD was investigated. A plastic IUD bearing copper foil (42 mm2) was inserted into one horn of the rabbit uterus and a physically similar platinum-bearing IUD in the contralateral horn served as a control. The Pt-IUD caused no tissue damage and little if any inflammatory reaction in ovariectomized, oestrous or pregnant animals, whereas the Cu-IUD produced endometrial ulcers in 14 out of 15 does in all hormonal states. The associated inflammation was particularly intense in the pregnant animals in which a unilateral pyometra was usually present. Despite the endometrial trauma produced, the Cu-IUD was only partly effective as a contraceptive agent, 36% of the ova shed from the ovary ipsilateral to the Cu-IUD implanting, compared with 63% of the ova ipsilateral to the Pt-IUD. However, almost half of the implantation swellings in the copper-bearing horns were abnormally small or distorted in shape at 9 days post coitum. The tissue destruction observed in the rabbit endometrium emphasizes the need for careful histological studies of the effect of the copper IUD on the human uterus.


Ultrastructural integrity of mouse testicular cells separated by velocity sedimentation.

Mouse testicular cells were examined ultrastructurally to determine whether the cells are damaged during the preparation of single-cell suspensions or during cell separation. The testicular cells were dissociated from seminiferous tubules by trypsinization and were fixed immediatley; fixed after being held in suspension for 4 h at 4 degrees C; or fixed after being separated into enriched fractions by sedimentation velocity either at unit gravity or by centrifugal elutriation. In general, the ultrastructural integrity of the cells, compared with that of corresponding testicular cells fixed in situ, was maintained during the dissociation and separation procedures. Ultrastructural abnormalities were most frequently produced in Sertoli cells and were occasionally observed in the acrosomes and nuclei of round spermatids. The cytoplasmic matrix of the midpiece of mature elongated spermatids or spermatozoa and the acrosomes of these cells were often disrupted. It is suggested that the dissociation procedures were responsible for most of the observed alterations of ultrastructural integrity.


A study of the time course of egg retention activity in the rabbit oviduct.

Changes in egg retention activity of the oviduct were assessed during the first 5 days after HCG-induced ovulation in rabbits. Dextran microspheres were used as ovum surrogates. They were injected into the peritoneal cavity at 0, 10, 32, 41, 50, 64, 72 and 80 h following HCG. The distribution of ova and surrogates in the genital tract was assessed 24 h following surrogate injection in all groups and at 8 h following surrogate injection in animals injected 50 h after HCG. The distribution of microspheres injected up to 50 h after HCG was similar to that of eggs. Surrogates were not retained at the ampullary-isthmic junction (AIJ) shortly after passage of ova through this region. Morever, spheres injected 38 h after ovulation reached the eggs at the proximal isthmus in 8 h or less. Surrogates injected at 64 h following HCG or later were retained at the AIJ, indicating resumption of retaining activity at this level. It is suggested that egg passage through the AIJ is associated with a temporary reduction of the retaining activity lasting for approximately 16 h. Retaining activity at the AIJ is regained before eggs pass from the proximal isthmus into the uterus.


Spermatogenesis in hybrid mice treated with oestrogen and testosterone.

Male BC3F1 hybrid mice were injected with 10 micrograms oestradiol benzoate/day alone or in conjunction with 80 micrograms testosterone propionate/day. Oestrogen alone decreased the weights of the accessory sex organs, but oestrogen + testosterone resulted in an increase. Assessment of spermatogenesis by a variety of methods revealed little effect of the hormones. Testicular weight and the histological appearance of the seminiferous epithelium was not altered appreciably, although Leydig cell atrophy was apparent when testosterone was given. The kinetics of spermatogenesis, studied by cell separation techniques and biochemical features of spermatogenesis, including protamine biosynthesis, lactate dehydrogenase levels and the formation of the highly resistant, condensed sperm nucleus, were also unaffected by the hormonal treatments. However, a reduction in the number of intact testicular spermatozoa in mechanically prepared cell suspensions was obtained. It is concluded that, in these animals, spermatogenesis is relatively insensitive to the administration of oestrogen.


Induction of nest-material collecting in male Barbary doves by intracerebral androgen.

The behaviour of the male Barbary dove (Streptopelia risoria) in selecting nesting material and transporting it to the nest site is reduced after castration and is restored by treatment with testosterone propionate when castrated males received unilateral intracerebral implants of this androgen. Implants in the anterior hypothalamus, preopitc region, and the area of the ventral neostriatum intermediale were effective in reinstating the collection of nesting material, and in many instances restoration of the behaviour was to levels at or above those observed before castration. Implants in other areas, and implants without hormone, were generally without effect. Although the brain areas from which the gathering of nesting material can be elicited are comparable to those from which courtship displays have been induced in previous studies, it appears that testosterone propionate implants stimulate nesting activities more effectively and more persistently than courtship.


Role models for women medical students.

Research about women physicians indicates that career/family conflicts modify professional involvement. At a large midwestern medical school, 192 women medical students were asked their ideas about women physicians as role models. The first- and second-year women differed significantly in their thoughts from the third- and fourth-year women. The former were acutely aware of an identity crisis as a woman. Their anxiety was projected into a need for a fourth-year elective with a woman physician. The third- and fourth-year women had little interest in working with a woman physician. Because of their anxiety regarding a physician's responsibility for patients, the competency of the physician was the major concern of these women; the sex of the teacher was irrelevant to their educational objectives.


Personality changes in a sample of women physicians.

Personality changes in a sample of 49 women physicians who graduated from the University of California, San Francisco, School of Medicine were measured by psychological tests and interview procedures. Differences between psychological test scores on entry and 8 to 11 years later were not great in magnitude, but they were consistent. The nature of the changes pointed in the direction of greated effectiveness in the area of work and achievements, more introspection, more certainty about goals, and more awareness and acceptance of traditional role demands. Correspondingly, there was a diminution of strivings for success and needs for impressing others. The most frequently cited changes by the women physicians were increased self-confidence and greater self-acceptance followed by more awareness of nurturant, loving feelings in themselves.


A comparison of personality types among female student health professionals.

The purpose of the study reported here was to focus on the personality traits of six groups of women students in medicine, pharmacy, medical technology, physical therapy, dietetics, and occupational therapy. The Myers-Briggs Type Indicator was administered to all groups to measure Extroversion-Introversion, Sensing-Intuition, Thinking-Feeling, and Judging-Perception. Results show that (a) medical students in contrast to the other five groups are guided more by thinking than feelings in their approach to work and people and (b) pharmacy students prefer well-planned, routine work in contrast to occupational therapy students who like changing situations and flexibility. Some implications of these findings for the health team are mentioned.


Internal review as a means of maintaining quality education in a medical school.

In order to focus attention on education, the University of Texas Medical Branch at Galveston adopted a system of internal review. The process was initially conducted for courses in the basic sciences by an ad hoc dean's committee consisting of representatives from the teaching faculty, administration, and student body as well as experts in medical education. As a consequence of the experience with the review of the basic science courses, the internal review process was applied to the clinical science courses and the elective programs at UTMB. The activities  of the internal review process have resulted in improvements in instructional procedures and structural changes in the medical school's approach to educational planning, implementation, and evaluation.


'Fifth pathway' in New York state medical schools.

During the academic year 1975-76, 259 students were enrolled in "fifth pathway" programs in New York and New Jersey. An analysis of students participating in programs in New York state schools revealed that a majority (87 percent) had received their undergraduate training at the Autonomous University of Guadalajara. The choice of graduate training of these students was similar to that of American graduates; however, the proportion of fifth pathway students selecting primary care specialties was significantly smaller than that of their American trained counterparts. Although the desirability of the fifth pathway has been a topic of frequent discussion, it is anticipated that for the next several years increasing numbers of students will be participants. It is, therefore, important to develop, at least on a regional level, uniform standards for admission and performance to assure the quality of this educational experience.


The questionnaire as a data-gathering device: medical school response patterns.

In this article the authors present the findings of a study of the process by which medical schools' internal information systems respond to external questionnaires. A representative sample of six medical schools was selected for the study, which was conducted under the joint auspices of the Association of American Medical Colleges and the Bureau of Health Manpower, Department of Health, Education, and Welfare. The process for completing four national questionnaires was analyzed following site visits and detailed documentation at each school. An overall objective of the study was to estimate the effect of this process on the quality of data supplied. A number of problems with the process which inhibited the provision of reliable data were found. These are highlighted and corrective action suggested both for the institutions completing the questionnaire and for the sponsoring agencies.


Attrition from general practice: career patterns of Toronto medical school graduates.

Reported here are the results of a study of the degree to which medical careers in general practice versus specialization are pursued by graduates of the University of Toronto Faculty of Medicine in the first six years after the completion of their internships. The retention rates in general practice and residency are documented on an annual basis using the life table method. The annual rate of attrition from general practice dropped substantially after the first three years. Fifteen percent of the initial general practice group dropped out during the first year, 10 percent of the remainder in the second year, and 8 percent of the rest in the third year. In each of the subsequent three years, the attrition rate was 4 percent, 4 percent, and 2 percent, respectively.


Students' attitudes toward cancer: changes in medical school.

This study focuses on the development of attitudes toward cancer during medical school. Under consideration were: (a) attitudes toward the patient's inner resources to cope with a serious illness such as cancer, (b) attitudes toward the value of early diagnosis, (c) attitudes toward the value of aggressive treatment, and (d) belief in immortality and preparation for the acceptance of death. Changes occurred throughout medical school, especially during the clinical years. More change appears to be related to medical education and experience that to personality. The findings have important implications for the education of medical students.


Ovulatory cycle characteristics in Macaca fascicularis.

A total of 595 menstrual cycles were studied in 28 adult M. fasicularis over a period of five years. Ovulations, observed laparoscopically in 138 cycles, occurred on the left ovary 62.6% of the time. No significant effect was noted on cycle length relative to the ovulatory status of the previous cycle or the occurrence of ovulation on the same ovary in consecutive cycles. Laparoscopy had no effect on the parameters studied.


Pulpotomy as an alternative to canine tooth extraction in monkeys [Macaca mulatta].

An effective method for sealing pulp canals after partial removal of canine tooth crowns from adult rhesus monkeys is described.


Human-type A-B-O blood group antigens of Ethiopian vervet monkeys (Cercopithecus aethiops) in the wild.

Human type A-B-O blood group antigens were tested in a local population of Ethiopian vervet monkeys (Cercopithecus aethiops). One animal was of group AB, the others were A. This represents a lower rate of polymorphism at this locus than has been observed among South African populations of the same species.


Kinetics of permeability changes induced by electric impulses in chromaffin granules.

Electric field pulses, ranging in intensity from 20 to 50 kV/cm and in duration from 10 to 40 micronsec, caused a transient increase in the membrane permeability of chromaffin granules from the bovine adrenal medulla, that led to partial release of granule soluble constituents. This transient permeability change was long-lived, as compared to the pulse duration, and the main part of material efflux occurred after the termination of the pulse. During the latter phase the temporarily increased permeability decayed to its original value, in the absence of the electric field. This indicated that the structural perturbation induced in the membrane was transient and apparently reversible. The release event was characterized by a field-dependent permeability coefficient ranging from 2x10(-4) cm/sec at 30 kV/cm to 3x10(-3) cm/sec at 50 kV/cm. The resealing process of the membrane could be described by two relaxation times, both of which decreased with increasing field strength. Tau1 varied from about 3.0 msec at 30 kV/cm to less than 2.0 msec at 50 kV/cm, while tau2 varied from about 100 to about 40 msec in the same interval of field strength. The distribution in the degree of filling of granules that had been partially depleted by an electric field pulse indicated that the population could be considered homogeneous with respect to release.