Superoxide, hydrogen peroxide, and singlet oxygen in lipid peroxidation by a xanthine oxidase system.

1. Xanthine oxidase acting aerobically upon acetaldehyde was found to cause the peroxidation of linolenate. This was demonstrated by increased absorbance at 233 nm due to diene conjugation and by the detection of a lipid peroxide spot on the thin layer chromatograms. 2. Superoxide dismutase inhibited this lipid peroxidation, as did catalase, thus indicating that both O2- and H2O2 were essential intermediates. Scavengers of singlet oxygen also inhibited the peroxidation of linolenate, whereas scavengers of hydroxyl radical did not. These effects, which were observed in the absence of iron salts, led to the proposal that O2- and H2O2 can directly give rise to a singlet oxygen, as follows: O2- + H2O2 leads to OH- + OH. + O2. 3. This proposal was further supported through the use of 2,5-dimethylfuran, as an indicating scavenger of singlet oxygen. Thus, when this compound was exposed to a known source of singlet oxygen, it gave a product which was detectable by thin layer chromatography. This product was also observed when 2,5-dimethylfuran was exposed to the xanthine oxidase system, in which case its accumulation was prevented by superoxide dismutase or by catalase, but not by scavengers of hydroxyl radical.


Gonadotropin binding and stimulation of cyclic adenosine 3':5'-monophosphate and testosterone production in isolated Leydig cells.

Gonadotropin binding and stimulation of cyclic adenosine 3':5'-monophosphate (cyclic AMP) formation and testosterone synthesis were studied in collagenase-dispersed interstitial cells from the adult rat testis. Binding of 125I-human chorionic gonadotropin (hCG) by isolated Leydig cells was of high affinity (Ka = 10(10) M-1) and low capacity, equivalent to approximately 6000 sites/cell. The binding data were consistent with the presence of a single order of receptors, with no interaction between binding sites. Stimulation of testosterone synthesis by increasing concentrations of hCG was completely dissociated from changes in cyclic AMP formation, and maximum activation of steroidogenesis was induced by hCG concentrations which had no effect upon cyclic AMP production. Kinetic analysis of gonadotropin-induced responses in dispersed Leydig cells also showed a marked dissociation between steroidogenesis and cyclic nucleotide formation. Low concentrations of hCG caused maximum stimulation of testosterone production which was not accompanied by a rise in cyclic AMP formation at any time after addition of gonadotropin. Higher concentrations of hCG caused marked elevations of cyclic AMP at progressively earlier time intervals, but did not alter the 20 to 30 min lag period required for induction of testosterone synthesis. These observations indicated that occupancy of gonadotropin receptors occurs over a much wider range of hCG concentration than that required for maximum steroidogenesis.


Specificity of the S1 nuclease from Aspergillus oryzae.

Conditions are described for digesting single-stranded DNA by S1 nuclease without introducing breaks in double-stranded DNA. The enzyme is inhibited by low concentrations of various compounds of phosphate. Under certain conditions S1 nuclease cleaves the strand opposite a nick in bacteriophage T5 DNA; under other conditions, the enzyme cleaves a loop in one strand of heteroduplex lambdaDNA while leaving the opposite strand intact. S1 nuclease makes many single strand breaks in ultraviolet-irradiated duplex lambdaDNA. Superhelical DNA of phiX174 (Form I) is converted first to a relaxed circular molecule (Form II), and then to a linear molecule (Form III) by cleavage at one site per molecule. Since the cleavage occurs at many sites in the population of molecules, the partially single-stranded regions in phiX174 superhelical DNA are not determined by specific nucleotide sequences.


Stimulation of adenylate cyclase from isolated hepatocytes and Kupffer cells.

Hepatocytes and Kupffer cells were separated from rat liver after prelabeling the Kupffer cells with colloidal iron and perfusion of the liver with digestive enzymes. The activity of several enzymes from Kupffer cells and hepatocytes was compared to validate this method of cell separation. The ratios of hepatocyte to Kupffer cell specific activities of glucose-6-phosphatase, 5'-nucleotidase, adenylate cyclase, and acid phosphatase were 20, 0.39, 0.18, and 0.078, respectively. Adenylate cyclases from hepatocytes and Kupffer cells were stimulated by fluoride ion, GTP, and catecholamines. Hepatocyte adenylate cyclase was also stimulated by glucagon, secretin, vasoactive intestinal polypeptide, and by prostaglandin E1, whereas, the Kupffer cell enzyme was completely insensitive to these hormones. The stimulation of hepatocyte adenylate cyclase by combinations of glucagon plus secretin, or glucagon plus vasoactive intestinal polypeptide, were equivalent to the sum of the individual stimulations. This suggests that the hepatocyte has specific receptors for glucagon and for vasoactive intestinal polypeptide and secretin. Prostaglandin E1 stimulation of hepatocyte adenylate cyclase was not additive to the stimulation caused by polypeptide hormones or catecholamines, nor did prostaglandin E1 decrease stimulation caused by these hormones. Although prostaglandin-sensitive adenylate cyclase was recovered with hepatocytes, 40 to 50% of the total liver prostaglandin-sensitive activity was recovered in a fraction of cell debris mixed with small cells which did not phagocytize colloidal iron.


Relative thrombogenicity of polydimethylsiloxane and silicone rubber constituents.

Medical grade silicone rubber (MGSR) is composed of polydimethylsiloxane (PDMS) as well as silica filler, oxidation products from the curing process, and other components. In a test that excludes air-blood interfaces, PDMS radiation cured under nitrogen has a whole blood clotting time 22% longer than MGSR. Curing the PDMS under oxidizing conditions maintains a 10% prolongation, but addition of silica filler to the PDMS returns the clotting time to that of MGSR. Extracting MGSR with solvents other than water appreciably lowers the clotting time. These results indicate the "pure" PDMS has an intrinsically high thromboresistance. Thrombogenicity is increased by the use of silica filler and oxidizing cure, as in MGSR.


Correlation of in vivo collagen degradation rate with in vitro measurements.

The rate of in vitro enzymatic degradation of various materials based on collagen has been determined by a novel mechanochemical method, and has been compared with the extent of degradation resulting from subcutaneous implantation in guinea pigs. In vitro data correlate well with in vivo data. It is suggested that the simple in vitro method described is an effective means of screening a large number of materials based on collagen for their ability to resist degradation during implantation in animals.


Improved high-performance liquid chromatographic method for polypeptide antibiotics and its application to study the effects of treatments to reduce microbial levels in bacitracin powder.

Improvements were made in the high-performance liquid chromatographic (HPLC) method to obtain baseline separation of chromatographic peaks of structurally similar polypeptide components in bacitracin. The improved method uses a 30-cm-long stainless-stell column packed with muBondapak C18. The theoretical plates of the column are approximately 140,000 per meter for the bacitracin A peak. The resolution function between bacitracins B1 and B2 and that between bacitracins A and B2 have been improved 418 and 225%, respectively. The components of bacitracin, bacitracins A, B, C, D, E, F, and G, were fractionated by the countercurrent distribution technique. These components, together with Compound X, a compound separated on a carboxymethylcellulose column, and bacitracin F, obtained by degrading bacitracin A sample at neutral pH, were used to identify peaks in the HPLC chromatogram. Effects of processing methods used to reduce microbial contamination levels in bacitracin powders were evaluated. Heat treatment caused a significant loss of antimicrobial activity (35% reduction), bacitracins A, B1, and B2 were reduced by 37, 22, and 21%, respectively. A significant increase (2.8 times) of bacitracin F, an oxidative degradation compound, was show. Irradiation by 60Co at 1.8 Mrad caused no loss of potency nor change in any of the bacitracin components. Ethylene oxide treatment, on the other hand, caused considerable (46%) reduction of potency. Substantial reduction of areas under the peak of bacitracins A, B1, and B2 (50, 24 and 37%, respectively) were noted. The chromatograms showed numerous unresolved peaks around bacitracins A, B1 and B2,; however, no significant increase in the bacitracin F peak, nor appearance of non-UV absorbing peaks were observed. Peptide antibiotics of the polymyxin group, circulin, colistin, and polymyxin, were also analyzed using the muBondapak C18 column with a linear-gradient elution. A UV monitor was used for polymyxin. A moving-wire flame ionization detector was used to monitor circulin and colistin. A sample of polymyxin, circulin, and colistin may be analyzed in less than 20 min of chromatographic time.


Primary aldosteronism due to a malignant ovarian tumor.

A case of a young woman with the syndrome of primary aldosteronism and malignant ovarian tumor is reported. Hormone studies revealed extremely high urinary aldosterone, undetectable plasma renin activity, elevated plasma 17beta estradiol and testosterone, and low plasma FSH and LH. Plasma cortisol and urinary 17-hydroxycorticoids were at the upper normal limits. Autopsy disclosed an ovarian tumor, histologically an arrhenoblastoma, with polymorphic aspects. The adrenal glands grossly were normal. Aldosterone was found by the double radioisotopic technique in the neoplastic tissue.


A testosterone-secreting, gonadotropin-responsive pure thecoma and polycystic ovarian disease.

A 31-yr-old hirsute female with oligoamenorrhea since menarche had markedly elevated peripheral plasma testosterone (T) concentrations of 250-255 ng/100 ml (normal 20-60 ng/100 ml), which lacked a diurnal rhythm, were not suppressed by dexamethasone, were decreased by ACTH, and were massively increased to 2,530 ng/100 ml by human chorionic gonadotropin (hCG). The binding capacity of T-binding globulin (TeBG) was 0.2 mug/100 ml (normal = 1.1-3.3 mug/100 ml). Plasma delta 4-androstenedione (A) was elevated at 374-681 ng/100 ml (normal = 90-135 ng/100 ml). Plasma estrone (E1) and estradiol (E2) were normal. The endometrium was proliferative. A T-secreting tumor was suspected because the plasma T levels were higher than those observed in polycystic ovarian disease. Exploratory surgery revealed bilateral polycystic ovaries and a pure thecoma in the right ovary which was not visible on surface examination. The thecoma did not contain granulosa cells. Plasma T in the right ovarian vein, draining the tumor, was 28,200 ng/100 ml and in the left ovarian vein was 2,600 ng/100 ml. Plasma A was elevated in both ovarian veins: 11,170 ng/100 ml on the left and 8,360 ng/100 ml on the right. The thecoma contained 1.35 mug/g of T and only 0.014 mug/g and 0.007 mug/g of E2 and E1, respectively. Plasma A and T after bilateral oophorectomy and removal of the thecoma were normal at 184 ng/100 ml and 40 ng/100 ml, respectively. 1) This pure thecoma produced primarily T rather than E1 OR E2 and was gonadotropin-responsive. 2) A very high plasma androgen level in a female is an important clue to the presence of a tumor. A T-secreting tumor should be ssupected when the peripheral plasma T is over 250 ng/100 ml and when plasma T increases to over 1,000 ng/100 ml following hCG stimulation. 3) Tumors cannot be classified as estrogenic or androgenic on the basis of the character of the endometrium.


Endocrine effects of pimozide, a specific dopaminergic blocker.

Pimozide, a specific blocker of dopaminergic receptors, was administered orally to 10 adult male volumteers for 4 days. Half of the subjects received 4 mg/day and the other half 2 mg/day. Blood samples were obtained the day before, the 4th day of Pimozide, and 4 days after the last dose of the drug for the determination of LH, FSH, GH, PRL, TSH, cortisol and testosterone levels. Twenty-four h urinary collections were obtained for the determination of LH and FSH levels. Plasma LH levels decreased and plasma PRL levels increased in the combined groups during Pimozide. Plasma TSH levels decreased during treatment in the 4 mg group only. Urinary LH and plasma testosterone levels decreased in the post-treatment period in the combined groups. These data support the concept of a dopaminergic control of the secretion of several hormones in the human.


Demonstration of immunoglobulin G receptors induced by human cytomegalovirus.

Human cytomegalovirus induced a new immunoglobulin G receptor in human fibroblasts. The immunoglobulin G receptor was well localized in the perinuclear region at 48 h postinfection, and antiviral agents blocked its synthesis. The immunoglobulin G receptor bound immunoglobulin G of man and several other species. It may be a source of error in the performance of indirect fluorescence tests for human cytomegalovirus antibody.


Mutant feedback-resistant phosphoribosylpyrophosphate synthetase associated with purine overproduction and gout. Phosphoribosylpyrophosphate and purine metabolism in cultured fibroblasts.

We have reported previously two siblings with gout and uric acid lithiasis associated with excessive purine production. In the erythrocytes of these patients, phosphoribosylpyrophosphate (PRPP) synthetase exhibited resistance to feedback-inhibition by normal cell constituents such as guanosine-5'-diphosphate (GDP) and adenosine-5'-diphosphate (ADP), resulting in superactivity of the mutant enzyme and consequently in increased PRPP content and availability for nucleotide synthesis. Erythrocyte PRPP content and availability were normal in the propositus' parents, his healthy brother and three sons, and they all had normal serum level and urinary excretion of uric acid, except for the mother who was hyperuricosuric. To further characterize this mutation we studied PRPP and purine metabolism in cultured fibroblasts of the affected family. PRPP synthetase in dialyzed lysates of fibroblasts from the propositus and his mother exhibited increased specific activity, more markedly at low inorganic phosphate concentration, and decreased sensitivity to inhibition by ADP and GDP, PRPP content and availability and the rate of de novo purine nucleotide synthesis were markedly increased in the fibroblasts of the propositus and to a lesser extent in the fibroblasts of his mother but were normal in the fibroblasts of the other family members investigated. The fibroblast studies demonstrate the following sequence of abnormalities: feedback-resistance of PRPP synthetase; superactivity of this enzyme in normal physiological milieu; increased availability of PRPP; and increased de novo synthesis of purine nucleotides. The pattern of inheritance of this disorder is compatible with both an X-linked recessive and autosomal dominant traits.


Complement and immunoglobulins stimulate superoxide production by human leukocytes independently of phagocytosis.

Human peripheral blood polymorphonuclear leukocytes, when exposed to appropriate stimuli, generate significant amounts of superoxide anion (O-.2), a highly reactive molecule which is possibly involved in bacterial killing. Since the subcellular localization and mechanism of activation of O-.2 generating systems are unknown, we have investigated superoxide dismutase-inhibitable cytochrome c reduction (attributable to O-.2) by, and lysosomal enzyme release from, normal polymorphonuclear leukocytes and cells rendered incapable of ingesting particles by treatment with cytochalasin B. Neither phagocytosis nor lysosomal degranulation were prerequisites for enhanced O-.2 generation. Cytochalasin B-treated cells exposed to (a) serum-treated zymosan, a C3b receptor stimulus; (b) heat aggregated human IgG, an Fc receptor stimulus; and (c) the complement component, C5a, generated enhanced amounts of O-.2 in a time and concentration-dependent fashion. These cells also responded by releasing lysosomal enzymes, but there was no correlation between the ability of any immune reactant to provoke enzyme release and its ability to stimulate O-.2 generation. The three stimuli also enhanced O-.2 generation by normal (untreated) polymorphonuclear leukocytes, but only serum-treated zymosan and aggregated IgG were capable of provoking lysosomal enzyme release from normal cells. Untreated zymosan and native IgG neither stimulated O-.2 production nor provoked lysomal enzyme release. Since enhanced O-.2 production was stimulated by immune reactants in the absence of phagocytosis, the O-.2 generating system is very likely associated with the external plasma membrane of the polymorphonuclear leukocyte. Leukocyte membrane receptors for complement and immunoglobulins may therefore not only serve in particle recognition but also may initiate biochemical events which accompany phagocytosis and killing.


Collagenase in scleroderma.

Collagenase activity was measured by direct assay in skins from 12 patients afflicted with systemic sclerosis. In seven of those cases where extensive involvement of the forearm and trunk skin existed, collagenase activity of the involved skin was minimal or absent. Moreover, in the same patient, regions of marked skin involvement (e.g., forearm) showed no collagenase activity, when clinically uninvolved areas (thigh) exhibited normal or nearly normal levels of enzyme activity. In other patients where clinical symptoms were systemic and not associated significantly with the skin, collagenase activity approximated normal levels. Measurements of collagenase activity and tensile strength in another condition (basal cell carcinoma) that includes changes in mechanical properties of skin that any be regarded as the opposite end of the spectrum from those of sclerodermatous skin support a general correlation between collagenase activity and tensile strength. These studies indicate that the major defect responsible for the hidebound skin lesions of scleroderma may be decreased collagenase activity.


Isolation and characterization of a novel vitamin B12-binding protein associated with hepatocellular carcinoma.

High levels of a novel vitamin B12-binding protein (hepatoma B12 BP) have been observed recently in plasma obtained from three adolescent patients with hepatocellular carcinoma. This protein has now been isolated in homogeneous form from the plasma and pleural fluid of two of these patients by the use of affinity chromatography with vitamin B12-Sepharose. The hepatoma B12 BP belongs to the R-type group of B12-binding proteins and is essentially indistinguishable from the recently isolated human milk and saliva R-type proteins in terms of: (a) immunologic properties based on immunodiffusion and immunoprecipitation assays; (b) amino acid composition; (c) molecular weight based on amino acid and carbohydrate content; and (d) absorption spectra. Both hepatoma B12 BPs contain more sialic acid and less fucose than the milk and saliva B12 BPs. All four proteins contain similar amounts of galactose, mannose, galactosamine, and glucosamine. Differences in sialic acid content appear to account for the differences in electrophoretic mobility that were observed among the four proteins. Differences in total carbohydrate content appear to account for the differences in apparent molecular weight that were observed with both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Tumor tissue from one of the patients contained 10 times as much R-type protein as did normal liver tissue from the same patient. This suggests, although it does not prove, that synthesis by the tumor is the cause of the high levels of R-type protein found in the plasma of certain patients with hepatocellular carcinoma. Plasma survival studies performed with rabbits indicate that the hepatoma B12 BP has a prolonged plasma survival and suggests that his parameter is also of importance.


Stimulation of monocyte cGMP by leukocyte dialysates. An antigen-independent property of dialyzable transfer factor.

We studied the effects of dialysates from leukocyte lysates containing dialyzable transfer factor activity and other leukocyte dialysates devoid of transfer factor activity on accumulation of cyclic nucleotides in human leukocytes. Dialysates from normal leukocytes produced 4- to 11-fold increases in leukocyte cGMP, and experiments with purified cell populations revealed that the increases were predominantly, if not entirely, in blood monocytes. Substances that increased monocyte cGMP could be obtained from several cell populations including mononuclear cells from Hypaque-Ficoll gradients, plastic-adherent monocytes, nonadherent lymphocytes, and neutrophils, but were not present in dialysates of leukemic lymphocytes from patients with the Sezary syndrome. Moreover, dialysates that increased leukocyte cGMP had essentially no effect on intracellular cAMP. Dialysates of lysed mononuclear cells contained serotonin, ascorbate, and an unidentified cholinergic activity, agents known to increase leukocyte cGMP. After passage of dialyzable transfer factor from mononuclear cells through a gel-filtration column, four fractions were obtained that increased leukocyte cGMP. Two of these fractions contained ascorbate; two other active fractions, including one that also caused conversion of delayed skin tests, did not contain detectable ascorbate or serotonin. The dialysate of lysed neutrophils also increased cGMP, but this activity was limited to the column fractions which contained ascorbic acid. These observations raise the possibility that alterations in monocyte cGMP content could modulate either the specific antigen-dependent, or, more likely, the antigen-independent activities in preparations of transfer factor.


Adenoid cystic carcinoma of the breast: prevalence, diagnostic criteria, and histogenesis.

Three cases of adenoid cystic carcinoma have been identified in a 10-year review of 2686 cases of breast carcinoma. The criteria necessary for diagnosis have been reviewed with particular reference to cribriform intraduct carcinoma and adenocarcinoma of the breast with small, dark, 'basaloid'-cell pattern. The most important single diagnostic criterion of adenoid cystic carcinoma is a biphasic cellular pattern which may be aded by the demonstration of two types of mucin stromal acid mucopolysaccharide and ductal neutral mucopolysaccharide. This tumour most frequently presents as a painful or tender mass near the areola, and it carries a uniquely favourable prognosis when compared with similar tumours elsewhere in the body. Actomyosin has been demonstrated in all three tumours by an immunofluorescent method, and this supports a predominantly myoepithelial origin.


A histochemical method of differentiating lower gastrointestinal tract mucin from other mucins in primary or metastatic tumours.

Epithelial mucins of the normal terminal ileum, caecum, colon, and rectum of man are unique in that they alone exhibit staining following the periodate-borohydride/KOH/PAS technique. Application of this technique enables one to differentiate those mucin-producting metastases arising from adenocarcinoma of the lower gastrointestinal tract from those arising elsewhere, and may occasionally be useful in determining the site of the primary tumour when it is in doubt. Furthermore, it was found to be especially useful in distinguishing between primary adenocarcinoma of the lung and metastases in the lung from adenocarcinoma of the lower gastrointestinal tract.


Membranes of mammary gland. XI. Marker enzyme distribution profiles for membranous components from bovine mammary gland.

Enzyme distribution profiles of clarified bovine mammary homogenates separated by equilibrium centrifugation on linear sucrose gradients suggested that several of the commonly utilized marker enzymes for rat liver are also valid markers for mammary cellular components. These marker enzymes include: Succinate dehydrogenase (mitochondria), nicotinamide adenine dinucleotide phosphate cytochrome c reductase and, to a lesser extent, retenone insensitive nicotinamide adenine dinucleotide cytochrome c reductase (endoplasmic reticulum), galactosyl transferase (Golgi apparatus), 5'-nucleotidase (plasma membranes), uric acid oxidase (microbodies), and acid phosphatase (lysosomes). Rotenone sensitive nicotinamide adenine dinucleotide cytochrome c reductase and sodium, potassium, magnesium-stimulated adenosine triphosphatase were widely distributed among subcellular fractions and are not valid marker enzymes. The boyant densities determined for the above fractions should aid in design of methods to obtain enriched sources of these components for analysis.


Variability in structural carbohydrates and in vitro digestibility of forages. 3. Guar (Cyamopsis tetragonoloba).

Thirteen genotypes of guar (Cyamopsis tetragonoloba) were compared with the local variety for structural carbohydrates and in vitro digestibility. Neutral detergent fiber, acid detergent fiber, lignin, and acid insoluble ash varied 31.2 to 44.4, 26.1 to 37.4, 6.8 to 11.1, and .30 to 1.11%. Cellulose varied from 16.6 to 28.1% whereas hemicellulose content ranged between 3.6 and 9.2%. In vitro digestibility of dry matter ranged between 62.8 to 71.2% Variation in protein, mineral matter, and percentage of dry matter was from 12.7 to 19.7, 9.4 to 12.3, and 23.0 to 26.7. Neutral detergent fiber and lignin plus silica were correlated negatively with in vitro digestibility of dry matter. A genetic manipulation of breeding material can bring about a highly nutritive genotype of guar.


Odontodysplasia.

Results of a comprehensive dental examination, including a histologic evaluation, of a patient showing unilateral odontodysplasia revealed no hint as to the origin of the abnormality. A complete medical examination also resulted in negative findings, with the excetion of congenital bilateral talipes equinovarus. The genetic history was negative, and results of chromosomal studies of the child and her mother revealed no abnormalities. Neither had an anatomic or a functional abnormality, with the exception of the odontodysplasia in the child. Results of laboratory studies including complete blood counts, urinalyses, ferric chloride tests of the urine, and electrolyte tests also were negative. The special considerations given in this case in an attempt to establish a possible causation of the abnormality were inconclusive. We think, however, that the management of the patient was successful in regard to the prosthetic appliance, and every attempt will be made to follow up the patient to ensure a good prognosis of the remaining developing dentition.


Effect of toothbrush variables on wear of dentin produced by four abrasives.

A study was conducted to explore the effect of brush brand, brush hardness, and the concentration of abrasive on the wear of human dentin by four dentifrice abrasives. The two hard brushes produced similar and high levels of abrasion, whereas the two medium brushes of the same brands gave dissimilar and lower levels of abrasion. Dilution changed the ranking of two of the four abrasives.


Toxic and reactogenic properties of pertussis bacteria (experimental and clinical studies).

The results of the study revealed correlation between the reactogenicity of pertussis vaccines in epidemiological observations and the toxic properties of pertussis bacteria in experiment. Quantitative and qualitative differences were found between the toxic factors in pertussis bacteria depending on their type-specific serological activity. Serotype 1.0.3 microbes exhibit more pronounced toxicity which accounts for the greater reactogenicity of vaccines prepared from this serotype as compared with the preparation produced from the serotype 1.2.3. The obtained results suggest the necessity of considering the greater toxicity of the serotype 1.0.3 in the preparation of pertussis vaccines.


Occurrence of antibodies to type 2 herpes simplex virus in the sera of town population.

In order to obtain a more detailed knowledge of the ecology of genital herpesvirus in Czechoslovak geographic and socioeconomic conditions, a total of 1 246 sera of town population, collected by the method of random selection from persons of different age groups in the town of Ostrava were examined in microneutralization reaction for antibodies to type 2 and type 1 herpes simplex virus. Antibodies to HSV-1 were present even in the youngest age groups 0--4 and 5--9 and positive findings in the older age groups ranged from 52 to 82% while antibodies to type 2 herpesvirus were found for the first time at the age of 14 (in one case); in adult persons they occurred in 17--26%. The mentioned results correspond to the sexual manner of transmission of genital herpesvirus and are in keeping with published findings.


Human leukemia-associated antigens: detection on cells of established lymphoblastoid lines.

Primate and rabbit antisera to different morphologic classes of human leukemia cells, after appropriate absorptions, detected leukemia-associated antigens present on cultured lymphoblastoid cell lines derived from leukemia patients. The primate antisera distinguished antigens on cells derived from myeloid leukemia patients from those on cells derived from lymphocytic leukemia patients. Of particular interest was the fact that antigens of myeloid leukemia, but not of lymphatic leukemia, were detected on lymphoid cell lines established from blood of patients with myeloid leukemia. One of four lymphoblastoid cell lines derived from normal donors expressed antigens of lymphatic leukemia. Leukemia-associated antigens were not found on the HRIK lymphoblastoid line derived from a Burkitt's lymphoma patient on skin fibroblasts or HeLa cells. Expression of these antigens on cultured cells derived from leukemia patients could not be related to the presence of the EB virus or the EB virus genome. Rabbit antisera detected antigens common to cells from patients with myeloid and lymphocytic leukemia. Absorption experiments demonstrated that the antigens detected on cell lines derived from leukemia patients are similar to those detected by the primate and rabbit antisera on fresh peripheral blood leukemic cells. The serologic detection of leukemia-associated antigens on lymphoblastoid cell lines indicates that some of these cultures contain cells with antigenic properties similar to those of human peripheral blood leukemic cells.


Immune and antibody responses to an isolated capsid protein of foot-and-mouth disease virus.

The purified capsid proteins VP1, VP2, and VP3 of foot-and-mouth disease virus type A12 strain 119 emulsified with incomplete Freund's adjuvant were studied in swine and guinea pigs. Swine inoculated on days 0, 28, and 60 with 100-mug doses of VP3 were protected by day 82 against exposure to infected swine. Serums from animals inoculated with VP3 contained viral precipitating and neutralizing antibodies, but such serums recognized fewer viral antigenic determinants than did antiviral serums. Capsid proteins VP1 and VP2 did not produce detectable antiviral antibody in guinea pigs, and antiviral antibody responses in swine to a mixture of VP1, VP2, and VP3 were lower than the responses to VP3 alone. However, when swine were inoculated with VP1, VP2, and VP3 separately at different body sites, no interference with the response to VP3 was observed. Vaccine containing VP3 isolated from acetylethylenimine-treated virus appeared less protective for swine than vaccine containing VP3 from nontreated virus. Trypsinized virus, which contains the cleaved peptides VP3a and VP3b rather than intact VP3, produced approximately the same levels of antiviral antibody responses in guinea pigs as did virus. Conversely, an isolated mixture of VP3a and VP3b did not produce detectable antiviral antibody responses in guinea pigs. The VP3a-VP3b mixture did, however, sensitize guinea pigs to elicit such responses following reinoculation with a marginally effective dose of trypsinized virus.


Cyclic GMP and lectin-induced lymphocyte activation.

Purified human peripheral lymphocytes incubated with the mitogenic plant lectins phytohemagglutinin and concanavalin A were examined for alterations in intracellular cGMP and cAMP under a variety of experimental conditions and using multiple techniques for the isolation and purification of cGMP and cAMP before assay of the cyclic nucleotides by radioimmunoassay. In contrast to work reported by others, we have been unable to demonstrate consistent increases in cGMP under any of the experimental conditions used and with any of the various purification schemes. In these same experiments exogenous cGMP added to the lymphocytes could be measured, and the immunoreactive material was destroyed by cyclic nucleotide phosphodiesterase, indicating that our inability to measure increases in cGMP was not caused by our inability to measure cGMP. Under identical experimental conditions, small but consistent and statistically significant increases in cAMP were noted. In addition, other parameters of lymphocyte activation, 45Ca uptake (an early parameter), and incorporation of 3H thymidine into DNA were unimpaired. These data call to question the concept of cGMP as the second messenger in lectin-stimulated human peripheral lymphocytes.


Experimental pneumococcal meningitis. II. Characterization and quantitation of the inflammatory process.

For the systematic study of the role of inflammation in the morbidity and mortality associated with bacterial meningitis, techniques for quantitation of the inflammatory reaction in the meninges of rabbits with experimental pneumococcal infection were developed. The brains of 19 infected animals were removed intact, and the area of inflammation in microscopic sections was quantitated by an electronic X-Y plotter connected to a computer. Exudate was maximal along the ventral surface of the brain at the level of the cerebellum. Inflammation increased progressively with time and peaked at 72 hr. In a separate group of 29 animals, lactic acid dehydrogenase concentrations in cerebrospinal fluid increased significantly during infection, and the rate of increase wirh time coincided with the increase in inflammation documented histologically. The described method of quantitating inflammation in the meninges during experimental meningitis makes it possible to study the increase in granulocyte involvement with time. The establishment of a direct relation between the concentration of lactic acid dehydrogenase in the cerebrospinal fluid and the inflammatory mass validates the use of lactic acid dehydrogenase as an indicator of inflammation.


Sensitivities of neurotropic arboviruses to human interferon.

The sensitivities of selected neurotropic arboviruses (St. Louis encephalitis, Western equine encephaltis, and La Crosse viruses) to human interferon and polyriboinosinic-polyribocytidylic acid (poly I-poly C) were determined in primary human fetal glial cell cultures. The sensitivities were measured by an end point (inhibition of virus yield). All of the viruses were sensitive to human interferon and poly I-poly C; St. Louis encephalitis and Western equine encephalitis viruses were inhibited at concentrations of interferon actually measured in the brains of persons who died from these infections. For St. Louis encephalitis and Western equine encephalitis viruses, viral replication and induction of interferon varied among cell cultures derived from individual fetuses. The present experiments may provide an approach toward understanding the problem of different host susceptibilities to neurotropic arbovirus infections.


Epidemiology of cytomegalovirus infection after transplantation and immunosuppression.

Viral infections and clinical complications were studied during hemodialysis and after renal transplantation. Active cytomegalovirus infection developed in 96% of patients after renal transplantation; reactivation of herpes simplex, varicella-zoster, and Epstein-Barr viruses was found in 35%, 24%, and 0% of patients, respectively. Cytomegalovirus viremia developed in 42% of patients an average of two months after renal transplantation, lasted 1.75 (+/- 1.5) months (except in one patient with chronic viremia), and was followed by chronic viruria. Higher titers of infectious cytomegalovirus were found in the polymorphonuclear than in the mononuclear leukocyte fraction. Reactivation of a latent infection and, less likely, respiratory infection appear to be the most probable mechanisms of cytomegalovirus infection after renal transplantation. One to three months after transplant, cytomegalovirus infection may be related to fever, arthralgia, pneumonitis, and leukopenia; three to four months after transplant, the virus may be related to hepatitis; and 12-30 months after transplant, it may be related to retinitis in patients with chronic viremia. Although other causes of these complications are possible, herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, measles virus, adenovirus, hepatitis B virus, and Toxoplasma gondii appear to be of lesser importance than cytomegalovirus in this respect.


Decreased interferon response by lymphocytes from children with chronic hepatitis.

Since a decreased interferon response has been linked with certain chronic viral infections, a preliminary study was undertaken to determine whether an altered interferon response may be involved in the pathogenesis of chronic hepatitis, a complication of type B hepatitis. The production of interferon by lymphocytes from patients with chronic hepatitis was compared with the production by lymphocytes from normal subjects. The amount of interferon produced by paramyxovirus-stimulated lymphocytes from 16 patients was substantially smaller than that produced by lymphocytes from 12 healthy donors. The results indicate that decreased production of interferon may be responsible for the chronicity of the disease. However, further studies are necessary to establish causality.


Experimental herpes simplex virus encephalitis: Comparative effects of treatment with cytosine arabinoside and adenine arabinoside.

Experimental herpesvirus encephalitis in weanling mice was treated with either cytosine arabinoside or adenine arabinoside to determine the comparative effectiveness of the two compounds on survival and on the concentration of virus in the brain. The uniformly fatal course of the encephalitis was not altered by any dosage of cytosine arabinoside. In contrast, treatment with adenine arabinoside resulted in long-term survival of the majority of the infected animals. The concentration of virus measured in the brains of animals treated with two different dosages of cytosine arabinoside indicated initial suppression of viral replication with a subsequent rise to levels higher than those in the untreated controls. In the brains of adenine arabinoside-treated animals, titers of virus gradually diminished to undetectable levels by the eighth day after institution of therapy.


Direct visualization of enveloped Epstein-Barr Herpesvirus in throat washing with leukocyte-transforming activity.

Mature enveloped virions belonging to the herpes class were found in a concentrated, partially purified specimen of throat washings from a patient undergoing immunosuppressive therapy for prevention of renal homograft rejection. This throat washing contained a high titer of biologically active Epstein-Barr virus and no other human herpesviruses. Epstein-Barr virions were not detected in throat washings from patients with mononucleosis that had only low titers of transforming activity.


Experimental infection of chimpanzees with hepatitis A virus.

The susceptibility of chimpanzees to viral hepatitis type A was examined with immine electron microscopy. Of four seronegative infant chimpanzees, two were inoculated with a hepatitis A acute-phase stool filtrate rich in 27 nm virus-like hepatitis A antigen (HA Ag) particles, and two were inoculated with an HA Ag-negative preinfection stool filtrate. One of each pair of chimpanzees was inoculated intravenously, the other orally. One month later both chimpanzees that had received the HA Ag-positive filtrate developed biochemical, histologic, and clinical evidence of acute viral hepatitis. HA Ag particle (27 nm) were detected in their stools by immune electron microscopy; particle shedding followed a pattern similar to that in human volunteers. Immune electron microscopy also showed that antibody HA Ag had developed in the convalescent-phase sera of the infected chimpanzees. Control animals remained free of illness at this time but did develop hepatitis three to five weeks after exposure to the two infected chimpanzee-. The infectious inoculum was titrated in two additional seronegative chimpanzees. It was concluded that hepatitis a can be successfully transmitted to seronegative chimpanzees. Moreover, these studies provide further evidence that the 27-nm virus-like HA Ag particle is the etiologic agent of viral hepatitis type A.


A prospective evaluation of heterophile and Epstein-Barr virus-specific IgM antibody tests in clinical and subclinical infectious mononucleosis: Specificity and sensitivity of the tests and persistence of antibody.

Three heterophile antibody tests and a test specific for IgM antibody to Epstein-Barr virus were evaluated during prospective studies of infectious mononucleosis. Specificity was judged by the frequency of false-positive results in sera of known qualities taken before illness; except for two patients bled during early, unrecognized illnes,, titers of greater than or equal to 1:40 were detected in 12% by the absorbed sheep red cell test, in 6.7% by the absorbed horse red cell test, and in none by the beef cell hemolysin test. None had IgM antibody specific for Epstein-Barr virus in sera obtained before illness. In addition, no rises in titer of heterophile antibody were detected by the horse cell test in 38 patients with proved rubella and/or influenza infection. In terms of sensitivity (indicated by the percentage of cases with diagnostic titers during infectious mononucleosis), 97% were positive by the Epstein-Barr virus IgM test, 96% by the horse cell agglutination test, 85% by the beef hemolysin test, and 81% by the sheep cell agglutination test. Persistence of antibody was judged by serial bleedings up to three years after illness; titers of heterophile antibody by the sheep agglutination and beef hemolysin tests as well as titers of IgM antibody to Epstein-Barr virus returned to normal in two to three months, whereas the horse cell heterophile test remained positive for a year or more in 75%. Inapparent and mild infections with Epstein-Barr virus resulted in the production of horse cell heterophile antibody in 48.4% of 122 subjects.


Comparative serial virologic and serologic studies of symptomatic and subclinical congenitally and natally acquired cytomegalovirus infections.

Infants with congenitally (38) and natally (17) acquired cytomegalovirus infection were prospectively studied by means of virologic and multiple serologic assays. These infections were characterized by chronic viral excretion (measured in years). The quantity of virus excreted in the urine during early infancy was significantly greater in infants who acquired infection in utero, particularly amon those born with overt disease; thereafter, all three groups (congenital symptomatic, congenital asymptomatic, and natal) excreted similar amounts of virus. The patterns of antibody responses, particularly the fluorescent antibody response to the early antigen and the complement-fixing antibody response, further indicated that congenitally infected infants (especially symptomatic ones) bear a greater antigenic burden than do natally infected infants. From a diagnostic standpoint, the test for fluorescent antibody to the late antigen was the most sensitive assay, whereas the test for complement-fixing antibody proved to be the least useful, The indirect hemagglutination assay, although performed only in infants with natal infection, was only slightly less sensitive than the fluorescent antibody procedure; by the former technique, diagnostic rises were detected in all but one infant after the onset of viruria.


Enhanced host defense mechanisms with levamisole in suckling rats.

Levamisole, a synthetically produced anthelminthic agent, was administered to suckling rats that were challenged with bacterial and viral pathogens. There was no in vitro antibacterial or antiviral effect of the drug. However, enhanced survival was demonstrated in those animals treated with levamisole and challenged with Staphylococcus aureus or herpes simplex virus. The mechanism for protection against the bacteria appears to be enhancement of the primary inflammatory response. The mechanism for protection against herpes simplex virus is not yet understood.


Experimental infection of marmosets with a cytomegalovirus of human origin.

Two adult and two neonatal cotton-topped marmosets and two neonatal white-lipped marmosets (Saguinus species) were inoculated with 10(7) plaque-forming units of cytomegalovirus (Colburn strain). No overt clinical disease developed in four marmosets during observation for eight months; one adult and one neonatal cotton-topped marmoset died from nonspecific causes 63 and 259 days after inoculation, respectively. By days 7-16 after inoculation, all marmosets developed plasma antibodies, which were detectable by neutralization and immunofluorescence assays (peak titers, 1:128-1:256 and 1:64-1:256, respectively). Attempts to isolate virus from whole blood, peripheral lymphocytes, oropharyngeal swabs, or vaginal swabs by cocultivation with permissive cell cultures were unsuccessful. Virus was recovered, however, by cocultivation from the kidney tissues of the adult marmoset that died. Immunosuppressive treatment with azathioprine resulted in a fourfold increase in antibody levels in plasma of two of three marmosets.


Effects of dichloromethylene diphosphonate, ethane-1-hydroxy-1,1-diphosphonate, and rickets in rats.

This study compared bone remodeling, bone mineralization, and parathyroid hormone secretion in rats treated with ethane-1-hydroxy-1,1-diphosphonate (EHDP) or dichloromethylene diphosphonate (Cl2MDP). The results were compared with findings in rachitic and control rats. In addition, calcification was induced in the skin by administration of lead acetate intravenously and polymyxin B subcutaneously; the efficacies of EHDP and Cl2MDP in preventing the calcific plaque were compared. Both the serum biochemical values and the morphologic findings indicate that Cl2MDP and EHDP influence bone and mineral metabolism differently. Even with the relatively large doses used in this study, Cl2MDP had a minor or no effect while EHDP had a marked effect that, in general, is undersirable. EHDP caused increase in circulating immunoreactive parathyroid hormone to levels greater than those in rachitic rats. Both diphosphonates appear to have a similar effect on the ectopic mineralization produced by calciphylaxis, suggesting that Cl2MDP may be the agent of choice in this problem because the undersirable side-effects would be avoided.


Hidradenomata of the external auditory meatus. (Review of the literature and report of a pleomorphic adenoma).

A case of hidradenoma of the external auditory meatus ('ceruminoma') is presented, with a review of the literature. The tumour has the appearances of a pleomorphic adenoma and is devoid of a capsule. It is suggested that the term hidradenoma be used for tumours of the ceruminous glands and that they be classified histologically as (1) adenoma, (2) pleomorphic adenoma, (3) adenoid cystic carcinoma and (4) adenocarcinoma. This classification aids treatment and prognosis. Attention is drawn to the high incidence of malignancy in hidradenomata of the external auditory meatus. The treatment of choice for pleomorphic adenomata is wide surgical excision with an adequate margin of normal skin. If there is doubt regarding complete removal, or a recurrence develops, a wider surgical excision is necessitated.


Responses of hair cells to statocyst rotation.

A new technique is described for stimulating hair cells of the Hermissenda statocyst. The preparation and recording apparatus can be rotated at up to 78 rpm while recording intracellular potentials. Hair cells in front of the centrifugal force vector depolarize in response to rotation. Hair cells in back of the centrifugal force vector hypoerpolarize in response to rotation. Mechanisms by which the hair cell generator potential might arise are examined.


Adaptation of N-tropic Friend leukaemia virus and its murine sarcoma virus pseudotype of non-permissive B-type C57BL/6 mouse cell line.

N-tropic Friend leukaemia virus (FLV) was serially passaged in a B-type C57BL/6 mouse cell line, YH-7. After a single passage, the infectious efficiency of FLV in the restrictive YH-7 cells was significantly increased. This adapted character of FLV could be reversed by a single passage in permissive N-type MLg cells. The true host range conversion from N to NB was accomplished after eleven to twelve passages in YH-7 cells. In contrast, the host range conversion of N-tropic murine sarcoma pseudotype, MuSV(FLV), took place after two passages.


Attempts to extend the genetic map of poliovirus temperature-sensitive mutants.

Eighteen new ts mutants of poliovirus have been isolated after a variety of mutagenic treatments, and their loci identified in relation to the previous genetic map. The map was only extended by 25%, and the physiological characters of the new isolates corresponded in all aspects tested with those of the previous isolates. Apparently single mutants at the extreme left of the map were defective in synthesis of both double- and single-stranded RNA, functions that do not co-vary in other mutants. Two procedures respectively predicted to induce mutations preferentially in the 5' and 3' regions of the genome gave isolates which all indicated that the structural protein region was nearest the 5' end. The loci fro resistance to dextran sulphate and to ethyl-2-methylthio-4-methyl-5-pyrimidine carboxylate both lie in the structural protein region.


On the use of chloramine-T to iodinate specifically the surface proteins of intact enveloped viruses.

Rous-associated virus-6I was used as a model for studying the labelling specificity of the chloramine-T iodination procedure when applied to intact enveloped viruses. The specificity of labelling depended markedly on the concentration of iodide in the reaction mixture. At low concentrations of iodide (below 0-5 muM) only the surface proteins and lipid of intact virions were iodinated; there was no detectable labelling of internal proteins. At 10 muM-iodide, however, both internal and external proteins were iodinated; moreover there was a marked change in the reactivity of the surface proteins. It appears that the lipid envelope provides an effective barrier to the iodinating complex generated at low, but not at high, concentrations of iodide. These and other observations suggest that the chloramine-T procedure has a previously unrecognized potential for specifically labelling the surface proteins of lipid-enveloped structures.


The polypeptide structure of transmissible gastroenteritis virus.

The polypeptides of purified preparations of the coronavirus responsible for transmissible gastroenteritis of pigs have beem examined by polyacrylamide gel electrophoresis. Four major polypeptides, VPI (mol. wt. 200000), VP2 (50 000), VP3 (30000) and VP4 (28500) and two minor polypeptides, VPIa (105000) and VPIb (80500) have been reproducibly demonstrated in the virion, of which VPI, VP3 and VP4 contain carbohydrate. Treatment of the virion with the proteolytic enzyme bromelain removes the surface projections and VPI, thus identifying this glycopolypeptide as the major structural component of the projection.


Two levels of restriction by mouse or cat cells of murine sarcoma virus coated by endogenous xenotropic oncornavirus.

Mouse and cat cells were each examined for the mode of restriction of endogenous xenotropic oncornavirus. Murine xenotropic helper virus (MuX) and its pseudo-type of Moloney murine sarcoma virus (MSV(MuX)) were grown in cat cells to high titre. MuX alone did not replicate in any mouse cell tested including normal or transformed outbred Swis 3T3 cells or SC-I cells, but did grow in a variety of other mammalian cells. MSV(MuX) was not able to achieve that intracellular state from which it could be rescued by mouse leukaemia virus (MuLV) in any mouse cell tested with the exception of SC-I cells. Detection of MSV(MuX) foci with appropriate helper virus was as sensitive in SC-I cells as in the cells of several other species. Sequential passage of MSV(MuX) virus complex in SC=I cells resulted in a loss of infectious sarcoma and helper viruses, but transformed, MSV rescuable cells were retained. If cat embryo cells were infected with either the feline endogenous xenotropic virus (FeX) or its MSV pseudotype (MSV(FeX), two analogous states of restriction were observed. FeX alone did not replicate in cat cells as measured by release of progeny virus or by FeX group-specific antigen induction. Cat cells could be susceptible or insusceptible to the entry of MSV(FeX) as measured by MSV rescue with appropriate ecotropic feline leukaemia virus. The sensitivity of detection of MSV(FeX) foci in some cat cells in the presence of feline ecotropic virus was comparable to that exhibited by cells of other mammalian species. A single strain of cat cells underwent a change in its restrictive capacity for MSV(FeX) on prolonged passage. Late passage cat cells became very insusceptible to MSV(FeX) but not to other pseudotypes of MSV. Infectious FeX or its group-specific antigens were not detected in the insusceptible cells. The major glycoprotein of FeX did appear as a surface antigen of the insusceptibel cells. It is apparent that two levels of cellular restriction can be distinguished in each of two mammalian cell systems by the susceptibility to penetration of MSV coated with endogenous xenotropic oncornavirus.


'Phagocytosis' of sendai virus by model membranes.

Sendai viruses were attached to liposomes (vesicular model membranes) at 0 to 4 degrees C, and were then incubated at 37 degrees C. Liposomes made of phosphatidylcholine, cholesterol and gangliosides enveloped the viruses at 37 degrees C to give a picture that resembles the ingestion step of phagocytosis. Virus particles were enveloped only by liposomes that contained gangliosides which serve as Sendai virus receptors.


Regulation by thymidine monophosphate and other nucleotides of thymidine kinase activity in extracts from primary rabbit kidney cells infected by HSV types 1 and 2.

In an attempt to differentiate between thymidine kinase (EC.2.4.1.21) induced by herpesvirus hominis type I (TK I) and type 2 (TK2), the different susceptibilities to the modifying effects of some thymidine analogues proved to be useful criteria: (I)2'-deoxythymidine-5'-triphosphate (dThd-5'-PPP) inhibits TK 2 at a concentration of 0-125 mM by 90%, whereas TK I is inhibited at 4-03 mM by 50%. (2) 2'-deoxythymidine-5'-monophosphate (dThd-5'-P) competitively inhibits TK 2 at all concentrations tested. On the other hand, the direction of its effect on TK I is concentration dependent: at 500 mum it stimulates and at 8 mM inhibits TK I activity. During enzyme kinetic studies, TK I displays substrate inhibition which is reversed by dThd-5'-P. This result explains the stimulating effect of dThd-5'-P at 500 muM. This phenomenon suggests the existence on the enzyme molecule of a second binding site for dThd which mediates substrate inhibition and which can be occupied also by dThd-5'-P. After polyacrylamide gel electrophoresis of TK I, the stimulation by dThd-5'-P disappears, suggesting the separation of the second binding site from the catalytic centre.


The site of anoxic block in the spinal monosynaptic pathway.

Asphyxiation of the spinal cord for periods of 2-4 min leads to block of the monosynaptic pathway. At about the same time this blockage takes place, the afferent action potentials fail to invade the presynaptic terminals. Asphyxiation also interferes with the antidromic invasion of motoneurons, and the failure of the antidromic action potentials to invade the motoneuron dendrites coincides with the time of the disappearance of the orthodromic monosynaptic responses. During reoxygenation, both the presynaptic terminals and the dendrites recover their function, or rather their polarization, in a few seconds and yet synaptic transmission reappears only after several minutes. It is postulated that failure of synaptic transmission during asphyxia is due to depolarization of both the presynaptic terminals and the dendrites of the postsynaptic elements. However, repolarization of these elements during reoxygenation, is not sufficient to reestablish synaptic transmission, but recovery of some unidentified biochemical process is apparently necessary.


Seizure susceptibility in the developing mouse and its relationship to glutamate decarboxylase and pyridoxal phosphate in brain.

The relationship between the susceptibility to convulsions, the content of pyridoxal 5'-phosphate and the activity of pyridoxal kinase (EC 2.7.1.35) and glutamate decarboxylase (EC 4.1.1.15) in brain, was studied in the developing mouse. Seizures were induced by pyridoxal phosphate-gamma-glutamyl hydrazone (PLPGH), a drug previously reported to reduce the levels of pyridoxal 5'-phosphate and as a consequence to inhibit the activity of glutamate decarboxylase in brain of adult mice. It was found that the seizure pattern, as well as the time of appearance of convulsions, differed between 2- and 5-day old mice and 10-day old or older mice, indicating a progressive increase in seizure susceptibility during development. In brain, pyridoxal kinase activity and pyridoxal 5'-phosphate levels were decreased by the administration of PLPGH at all ages studied, whereas glutamate decarboxylase activity was inhibited less than 25% in 2- and 5-day old mice, and about 50% thereafter. Parallelly, the activation of glutamate decarboxylase by pyridoxal 5'-phosphate added in vitro to control homogenates was less in 2- and 5-day old mice than in older animals. It is concluded that the increase in the susceptibility to seizures induced by PLPGH during development is probably related to the increase observed in the sensitivity of glutamate decarboxylase in vivo to a decrease of pyridoxal 5'-phosphate levels. The correlation between pyridoxal 5'-phosphate, glutamate decarboxylase, and seizure susceptibility seems to be established at about 10 days of age.


Phenothiazine antagonism of the noradrenergic inhibition of cerebellar Purkinje neurons.

Phenothiazine derivatives were examined as potential antagonists of the inhibitory noradrenergic synapses from the nucleus locus coeruleus to rat cerebellar Purkinje cells. Fluphenazine, and its thioxanthine analogue, flupenthixol, antagonized the inhibitory action of norepinephrine, when iontrophoretically applied to single cells. Alpha-flupenthixol was generally more active than the beta isomer. Fluphenazine had no appreciable effect on inhibitions induced by iontophoresis of GABA or cyclic AMP. Parenteral fluphenazine also blocked the inhibition of Purkinje cells produced by the stimulation of the noradrenergic pathway from locus coeruleus, but basket and stellate cell inhibitory inputs to Purkinje cells were unaffected. These data suggest that fluphenazine can specifically block a known central adrenergic inhibitory pathway.


Neuromuscular junctions in the buccal mass of Aplysia: fine structure and electrophysiology of excitatory transmission.

The lower extrinsic protractor muscle in the buccal mass of Aplysia consists of bundles of muscle fibers 4--12 mu in diameter, containing thick and thin filaments that are not arranged in a transversely striated pattern. Individual fibers come close to one another and form specialized junctional regions. Electrophysiological evidence indicates that the muscle fibers form an electrical cyncytium. Muscle bundles are innervated by more than one excitatory axon at a number of points along their length. The presynaptic terminals contain spherical electron-lucent vesicles and a few larger electron-dense vesicles. There are no obvious structural postsynaptic specializations. Graded contraction can result from summation of excitatory junctional potentials in separate axons or from summation and facilitation of junctional potentials from a single axon. The buildup of facilitation during a train of stimuli results from the linear summation of facilitation remaining from preceding impulses.


Soradic ulcerative mutilating acropathy with imbalance of free amino acids in the cerebrospinal fluid.

A case of sporadic ulcerative mutilating acropathy is described. Muscle biopsy showed signs of neurogenic atrophy. Motor nerve conduction velocity was slightly reduced. The muscles of the foot were completely unresponsive to electric stimulation of both femoral nerves. The content of free amino acids in serum and cerebrospinal fluid was determined by ion exchange chromatography, and compared with a control group. While in serum no significant changes were found, in CSF most amino acids showed great alterations, mainly consisting in an increase. It is suggested that the primary disturbance may be located in the spinal nerve roots.


Experimental neuropathy produced by 2,5-hexanedione--a major metabolite of the neurotoxic industrial solvent methyl n-butyl ketone.

Chronic exposure of rats to 2,5-hexanedione (CH3COCH2CH2COCH3), a major metabolite of the neurotoxic industrial solvent methyl n-buryl ketone (CH3COCH2CH2CH2CH3), has been shown to cause a clinical peripheral neuropathy with dying-back peripheral and central nervous system degeneration characterized by giant axonal swellings filled with neurofilaments. This pattern of disease is similar to that produced by methyl n-butyl ketone.


Safety factor in single human motor end-plates studied in vivo with single fibre electromyography.

In a single fibre EMG investigation on healthy subjects the relationship between the neuromuscular jitter and the safety factor of the motor end-plate relative to curare was studied. A positive correlation was found between the jitter increase after a standard dose of D-tubocurarine and the initial jitter. The conclusion was drawn that the neuromuscular jitter can be used as an indicator of the safety factor. There are a number of nerve-muscle disorders in which the jitter is increased, probably indicating a reduced safety factor which may be of clinical importance when these patients are subjected to diseases or drugs which would otherwise not produce neuromuscular symptomatology.


Regional curare for the reduction of the safety factor in human motor end-plates studied with single fibre electromyography.

A method employing six minutes of regional curarization with 0.5 mg D-tubocurarine and single fibre electromyographic measurements (SFEMG) was used in order to study the effect of an additional small dose of D-tubocurarine. The effect of the additional dose was most pronounced in terms of increased jitter, on motor end-plates with the initially highest jitter. The combination of regional curarization and SFEMG jitter recordings offers a sensitive technique for detecting mild effects of various drugs on neuromuscular transmission not detectable with decrement investigations.


Single fibre EMG findings in polyneuropathies of different aetiology.

Single fibre electromyography was carried out in patients with polyneuropathy due to uraemia, diabetes, and alcohol. In the two former groups the fibre density within the motor unit and the impulse transmission were mainly normal. In the latter group the fibre density was significantly increased as signs of reinnervation. Impulse transmission was impaired in a number of the action potential complexes, which is typical of active reinnervation. The results may indicate that the diabetic and uraemic polyneuropathies are characterized in the main by demyelination, whereas the alcoholic type is dominated by axonal lesion even at an early stage.


5-Hydroxytryptophan and sleep in Down's syndrome.

Polygraphic total night sleep electroencephalographic (EEG), electro-oculographic (EOG) and electromyographic (EMG) recordings have been made in 6 mongoloid infants who received oral 5-HTP for periods extending from 12 to 36 months. The doses were adapted to the infants' age and tolerance level. The oculomotor activity of paradoxical sleep (PS) was selectively analysed. The eye-movement (EM) density was significantly decreased in non-treated mongoloids as compared with that of normal age-related infants. Out of the 5-HTP-treated patients, however, the results in only 2 were within the limits for normal age-related infants. 5-HTP failed to induce any long-term differences in the EM frequencies. In fact, the drug had a short-term effect lasting up to 8 days. An increase in muscle tone and an improvement of motor behaviour were the only long-lasting results.


An immunopathologic component in experimental togavirus encephalitis.

The effects of immune manipulation upon survival and histopathology in two experimental group B togavirus encephalitides were studied in inbred mice. The median survival time 8 days after intracerebral injection of Langat virus increased to 10 days with an immunosuppressive course of cyclophosphamide, with concomitant reduction in the inflammatory response. Adoptive immunization with immune lymphoid cells or serum also tended to prolong Langat virus survival while increasing inflammation. Survival following intracerebral West Nile virus (7 days) was unaffected by immunosuppression or adoptive transfer, although suppression was associated with less severe CNS lesions, and immune serum with less necrosis. These findings indicate that the immune response may be both protective and pathology-inducing in some togarvirus encephalitides. The differences in host response to these two related agents suggest caution in generalizing about the role of the immune response in viral infections.


Nuroaxonal degeneration induced by sodium diethyldithiocarbamate in cultures of central nervous tissue.

Well myelinated cultures of newborn mouse cerebellum, exposed to varying concentrations of sodium diethyldithiocarbamate (DDC), a heavy metal chelating agent, were examined by light and electron microscopy. DDC treatment of cultures for 24-48 hours produced swellings of axons and presynaptic endings, the morphological features characteristic of dystrophic axons. The axonal swellings contained an increased amount of endoplasmic reticulum, mitochondria and dense bodies. A continued exposure to DDC induced an extensive degeneration of axons and ensheathing myelin. Glial cells, on the other hand, were structurally intact even after a long-term exposure to DDC. It is suggested that DDC produces in myelinated CNS cultures an initial enlargement of axons and presynaptic endings and then continues to induce Wallerian degeneration in axons.


Cerebral dynamic studies for early detection of recurrent anaplastic intracranial gliomas.

The authors compared radionuclide cerebral dynamic studies, brain scans, and clinical evaluation as indicators of recurrence of intracranial anaplastic gliomas and found cerebral dynamic studies more sensitive to tumor growth than static brain scans. The former may show changes prior to clinical evidence of tumor progression.


Central functional changes after facial-spinal-accessory anastomosis in man and facial-hypoglossal anastomosis in the cat.

A left facial-spinal-accessory anastomosis was performed for peripheral facial paralysis in an 8-year-old boy. By the fourth postoperative year, the corneal reflex showed a normal latency, and left arm and face movements could be executed independently. The possibility of neural plasticity playing a role in establishing new central relationships which enable the achievement of a "normal" latency corneal reflex and independent face and arm movements is discussed. The latency of the corneal reflex recorded as electrical response of the orbicularis oculi muscle to electrical stimulation of the ipsilateral cornea was measured in normal cats and cats which had undergone a facial-hypoglossal anastomosis 12 to 14 months previously. The latency of the reflex was 8 to 22 msec in normal animals and 200 to 300 msec in the operated cats, while conduction times in the regenerated hypoglossal nerve fibers were found to be within normal limits. This suggests that the long latency of the corneal reflex following the cross anastomosis is due to the time required for transmission across newly-formed connections between the trigeminal terminals and the hypoglossal neurons.


A qualitative and quantitative electronmicroscopic study of the structure of the adenoid cystic carcinoma of human minor salivary glands.

The fine structural characteristics of five adenoid cystic carcinomas of human minor salivary galnds and a quantitative assessment of the relative volumes occupied by morphologically defined cell types in these tumors are reported. We observed that the cyst-like spaces which give the characteristic cribriform pattern to the adenoid cystic carcinoma contain replicated basement membrane-like materail. Material comprisimg aggregates of fine tubules having a median diameter of 270 A, and rounded, electron dense bodies were noted within duct-like lumena of one tumor. In addition, dilatation of the intercellular spaces and squamous metaplasia were noted. From 500 electronmicrographs obtained by standardized techniques and used for the morphological part of the study, 175 were selected by a random sampling method and analyzed by the stereological technique of point counting. This method demonstrated that duct type cells occupied 75% by volume of the tumor in these glands; myoepithelial cells occupied 3%, acinar cells occupied 2%, and other tissues occupied 22% of the tumors. These proportions differ significantly (P less than 0.001) from our previously published figures for normal specimens of these glands.


Evaluation of parotid gland masses by rectilinear scanning.

Twelve salivary gland scans, done preoperatively for evaluation of parotid masses, included nine cases of Warthin's tumor. In addition to Warthin's tumor showing an accumulation of pertechnetate, increased activity was also present in two cases of mixed tumors. Warthin's tumor may also show decreased activity, with or without a large cystic component. Therefore, the interpretation of preoperative salivary gland scans must be made with caution.


Melanotic neuroectodermal tumor of infancy.

Recurrence of a melanotic neuroectodermal tumor of infancy was clinically evident eight weeks after the original lesion had been surgically removed. Concentrations of urinary vanilmandelic acid were elevated immediately after surgery but returned to normal a month after removal of the tumor. The location of the recurrent tumor, the rapidity of recurrence, and the concentrations of urinary VMA favor a theory of neural crest origin.


Cushing syndrome, sexual precocity, and polyostotic fibrous dysplasia (Albright syndrome) in infancy.

The sexual precocity of polyostotic fibrous dysplasia is occasionally accompanied by other endocrine disorders, but in only two previous instances has Cushing syndrome been reported. The history of a 6-month-old girl is presented, in whom this syndrome was complicated by congenital Cushings syndrome. Although endocrinopathies of polyostotic fibrous dysplasia have usually been ascribed to a central (hypothalamic) origin, the findings in this patient suggest autonomous hyperfunction of the peripheral endocrine glands, with the Cushing syndrome caused by hyperplastic nodules in the adrenal glands and the precocity by luteinized follicular cysts of the ovary.


Viral hepatitis: recent developments and prospects for prevention.

During the past decade new development in hepatitis research have shed new light on the etiologic, epidemiologic, immunologic, and prophylactic aspects of type A and B hepatitis virus infection. Recent advances in hepatitis A virus research include: (1) identification of the virus as a 27 nm particle with characteristics resembling an enterovirus, (2) transmission of the infection to marmosets and chimpanzees, and (3) development of specific complement fixation and immune adherence antibody tests. Recent advances in hepatitis B research include: (1) identification of the virus as a 42 nm particle (Dane particle) containing an outer coat, the hepatitis B surface antigen, and an inner core, the hepatitis B core antigen, (2) development of specific tests to detect the hepatitis B antigens and their respective antibodies, (3) transmission of the infection to chimpanzees, (4) development of a specific hepatitis B immune serum globulin, and (5) development of an inactivated hepatitis B vaccine.


The effects of stibophen on phosphofructokinases and aldolases of adult filariids.

Trivalent organic antimonials, such as stibophen, have been employed for the chemotherapy of schistosome and filariid infections. The effects of stibophen on adult Litomosoides carinii, Dipetalonema witei (= viteae), and Brugia pahangi were examined. In vitro, lactate accumulation was markedly inhibited by the antimonials as was phosphofructokinase activities in homogenates. Incubation of filariids with stibophen and determination of internal concentrations of hexose phosphate also indicated a decreased phosphofructokinase activity. In addition, a second inhibitory effect of stibophen on aldolase has been observed which appears to be specific for stibophen and is not displayed by potassium antimony tartrate. Both inhibitory activities may contribute to the chemotherapeutic effect of stibophen. In addition to the schistosomes and filariids, stibophen also inhibits Ascaris and Hymenolepis diminuta phosphofructokinases at low concentrations, where no inhibition of the corresponding mammalian liver enzyme was demonstrable.


Heligmosomoides polygyrus (=Nematospiroides dubius): the development of self-cure and/or protection in several strains of mice.

Strains of outbred (ICR/CD1 and S--W) and inbred (BALB/C and C57BL/6) mice vaccinated subcutaneously (SQ) with 500, 1,000, or 2,000 exsheathed Heligmosomoides polygyrus larvae developed varying levels of protection upon subsequent oral challenge with larvae. In contrast, the inbred C3H/HEJ strain failed to develop protection at any dosage level tested. ICR/CD1 mice vaccinated intraperitoneally with exsheathed larvae developed a high level of resistance but exhibited extensive adhesions of the viscera. When ensheathed larvae were used for vaccination, ICR/CD1 mice developed a moderate level of protection; but 1% of the vaccine dose was recovered in the intestine as adult stages. Both the inbred and outbred strains given multiple oral infections developed a protection response similar to that strain's response following parenteral vaccination. The specificity of this protection was demonstrated using various complex foreign antigens. In contrast, the self-cure response was observed only in the S--W strain.


Bench surgery and renal autotransplantation in the pediatric patient.

A new operative procedure in renal surgery has evolved from the extensive recent experience in kidney transplantation. Bench surgery and autotransplantation have not been, as yet, fully exploited by surgeons caring for children. This approach to reconstruction of renal substance and renal vessels has as its greatest dividend conservation of kidney tissue. The operation has specific applicability for selected cases of: (1) renovascular hypertension; (2) congenital obstructive uropathy; (3) bilateral Wilms' tumor, and; (4) renal trauma in children.


Preoperative therapy for unresectable malignant tumors in children.

Thirty-six children with initially unresectable malignant tumors were managed with pre- and postoperative therapy combined with reduction of primary tumor burden by total or subtotal resection. The proportion of patients achieving long-term tumor-free survival after surgery was 0.48 in the Wilms' tumor group and 0.60 among patients with other regionally unresectable malignant neoplasms. These results are encouraging in an otherwise high mortality situation.


Differences in cAMP levels in the gingival fluid of diabetics and nondiabetics.

Gingival fluid from eight control subjects and ten diabetics was collected and the content of cAMP and protein in the fluid was assayed to determine the nature of the biochemical changes occurring in the gingival fluid due to diabetes. The gingival fluid of the control subjects had a cAMP concentration of 2.4 X 10(-6) M, which was a hundredfold greater than that seen in serum, thus suggesting that the cAMP in the fluid resulted from active synthesis by the gingival cells and was not merely a transudate from the blood. The gingival fluid of the diabetics contained only one-seventh the level of cAMP seen in the control group. It is suggested that the decreased level of cAMP seen in the givgival fluid of diabetics may be a manifestation of a defect in the cAMP forming mechanism of the gingival tissue, which may reflect the systemic etiology of diabetes. It was also found that in the control subjects the content of cAMP in the gingival fluid was in inverse proportion to the volume of exudate in the gingival crevice. No such relationship was seen in the diabetic group. It appears that the level of cAMP present in the gingival fluid of normal individuals without any generalized endocrine deficiencies may be used as an additional indicator of the inflammatory status of the gingival tissues, along with the clinical evaluation based on gingival index.


Metabolism of 8-(methylthio)cyclic 3',5'-adenosine monophosphate by rats and dogs after oral or intravenous dosing and in vitro by subcellular preparations of dog liver.

8-(Methylthio-14C or -35S)cyclic 3',5'-adenosine monophosphate (I) was given intravenously to rats (5 mg/kg) and orally and intravenously to dogs (0.25, 2.5, or 50 mg/kg). Oral doses were absorbed well but slowly. Plasma half-lives in dogs were about 3 hr after oral or intravenous doses of 0.25 or 2.5 mg/kg and ranged from 5 to 12 hr after oral or intravenous doseas of 50 mg/kg. Plasma glucose and insulin concentrations in dogs were increased by oral or intravenous doses of the compound. Regardless of the route, excretion of radioactivity by rats and dogs at all doses was chiefly in the urine (74-87% of the dose); the remainder was excreted in the feces or bile. Compound I was rapidly distributed to most tissues of dogs but entered the brain and certain portions of the eye slowly and to a limited extent. Urine and plasma of dogs and urine of rats contained I, 8-(methylthio)adenosine, and at least two other unidentified metabolites. Compound I and cyclic 3',5'-adenosine monophosphate were metabolized in vitro by the soluble fraction of dog liver to form 8-(methylthio)adenosine-5'-monophosphate and adenosine-5'-monophosphate, respectively. These compounds were further converted to 8-(methylthio)adenosine and adenosine, respectively. Compound I was metabolized in vitro more slowly than cyclic 3',5'-adenosine monophosphate.


Effects of selected drugs on an auditory or thalamic conditioned stimulus eliciting recruitment in the cat.

Minimally effective oral doses of chlorpromazine, imipramine, and pentobarbital necessary to block a discrete trial (bar-press) conditioned avoidance response were compared in cats chronically implanted with electrodes over the cerebral cortex and in the nucleus centralis medialis of the thalamus. Three conditioned stimulus contingencies consisting of tone and low or high voltage thalamic stimulation were presented. Minimal conditioned response blocking doses of these agents produced only slight qualitative changes in cortically recorded recruitment. Drug treatment affected the conditioned stimulus contingencies differentially, and the rank order in terms of ease of disruption of the conditioned avoidance response was high voltage thalamic conditioned stimulus greater than low voltage thalamic conditioned stimulus greater than auditory conditioned stimulus. The differential effect of these drugs might have been due to the additive inhibition of these agents and the thalamic conditioned stimulus on performance. With the exception of chlorpromazine, the behavioral effects of these drugs and their effects on recruitment were dissociated.


Protective effect of selenium on certain hepatotoxic and pancreotoxic manifestations of subacute cadmium administration.

Administration of cadmium chloride (1.0 mg/kg s.c.) to rats, twice a day for 7 days, significantly stimulated the activities of hepatic pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-diphosphatase and glucose 6-phosphatase, markedly increased the concentration of hepatic cyclic adenosine monophosphate and circulating blood glucose and significantly reduced serum insulin levels. Furthermore, subacute exposure to cadmium induced glucose intolerance that was associated with a decreased pancreatic secretory activity as evidenced by lowered insulinogenic indices and marked inhibition of phentolamine-stimulated insulin release. In contrast to cadmium, administration of selenium dioxide (2 X 1.0 mg/kg/day s.c., 7 days) failed to alter significantly the activities of gluconeogenic enzymes, hepatic cyclic adenosine monophosphate, blood glucose or serum insulin levels, glucose tolerance or the pancreatic secretory activity. However, administration of selenium concurrently with cadmium completely prevented the cadmium-induced increases of hepatic gluconeogenic enzymes. Treatment with selenium ameliorated the cadmium-induced hyperglycemia, hypoinsulinemia, glucose intolerance and the suppression of pancreatic secretory activity, whereas it failed to alter significantly the cadmium-induced elevation of hepatic cyclic AMP levels. Data provide evidence suggesting that subacute exposure to cadmium alters several parameters of carbohydrate metabolism and suppresses pancreatic secretory activity and that administration of selenium alone is without any appreciable effect on the above parameters. However, administration of selenium concurrently with cadmium prevents, to varying degrees, several of the cadmium-induced metabolic and functional changes.


Effects of pressure and anesthetics on conduction and synaptic transmission.

The antagonism observed between pressure and anesthesia in intact animals suggests that pressure antagonism may be a promising criterion for identifying the effects of anesthetics which are important to loss of responsiveness. It is therefore of interest to compare the effects of pressure and anesthesia on conduction and on synaptic transmission, which have often been proposed as possible alternative cellular sites of anesthesia. The model used in this study is the isolated rat superior cervical ganglion. Helium pressure (35-103 atm) antagonized partial conduction block of the preganglionic nerve by halothane(0.5 and 1 mM). Helium pressure failed to antagonize the depressant effects of halothane (0.25-0.5 mM) on nicotinic transmission and of halothane or methoxyflurane (0.24 mM) on muscarinic transmission in the ganglion. Pressure itself severely depressed synaptic transmission and added to the depressant effects of the anesthetics. Conduction block as a possible cellular mechanism of anesthesia therefore meets the proposed criterion of pressure reversibility. In contrast, pressure does not antagonize anesthetic depression of excitatory synaptic transmission in the rat superior cervical ganglion.


Synaptic transfer at a vertebrate central nervous system synapse.

1. The relation between presynaptic depolarization and transmitter release was examined at a synapse between a Müller axon and a lateral interneurone in the spinal cord of the lamprey. Two micro-electrodes, one for passing current and the other for recording the resulting voltage change, were placed in the presynaptic axon; a single electrode for recording the post-synaptic potential produced by release of transmitter was placed in the post-synaptic cell. 2. When action potentials were blocked with tetrodotoxin, brief depolarizing pulses in the presynaptic fibre were as effective as the action potential had been in producing transmitter release. 3. The release process had an apparent threshold depolarization of 40-50 mV and saturated at presynaptic depolarizations of the order of 100 mV. Increasing the duration of the presynaptic pulse increased the maximum level of release. 4. Displacing the presynaptic voltage recording electrode from the position of synaptic contact toward the current passing electrode increased the apparent depolarization required to produce a given level of transmitter release. This shift in the input-output relation was consistent in magnitude with the voltage attenuation between the presynaptic recording electrode and the synapse expected from the space constant of the fibre. 5. The effect of conditioning hyperpolarization and depolarization of the presynaptic fibre on subsequent transmitter release by brief depolarizing pulses was examined. No effect was observed when the presynaptic recording electrode was in the region of synaptic contact. When the presynaptic electrode was not so positioned, conditioning effects were observed which depended on electode position and could be attributed to changes in the space constant of the presynaptic fibre. No conditioning effects were observed on transmitter release by the action potential.


Post-synaptic potentiation: interaction between quanta of acetylcholine at the skeletal neuromuscular synapse.

1. Post-synaptic responses to acetylcholine (ACh) released from nerve terminals and from iontophoretic micropipettes were investigated in skeletal muscle fibres of the snake. Each fibre has a compact end-plate consisting of fifty to seventy synaptic boutons. The fibres were voltage clamped, and synaptic currents were recorded from visually identified end-plates. 2. When acetylcholinesterase (AChE) is inhibited, a potentiating interaction is observed between two or more quanta that are released close to each other from a synaptic bouton and act upon partially overlapping postsynaptic areas. The potentiation is expressed as a prolongation of the synaptic current. This potentiation also occurs under normal conditions of release when about 300 quanta are distributed over the entire end-plate, so thet the presynaptic release sites are separated by an average of 2 mum. An analogous potentiating interaction is observed when micropipettes, closely apposed to the subsynaptic membrane, substitute for quantal release sites. ACh from one pipette potentiates the response to ACh from another pipette less than 2 mum away. 3. In contrast, with AChE fully active no post-synaptic potentiation is seen when the normal complement of quanta is released over the entire end-plate. The time course of the synaptic currents in response to a single quantum or to 300 quanta is similar. It is concluded that functionally the quanta act independently of each other, because AChE isolates each quantum from its neighbours by limiting the lifetime of ACh and its lateral diffusion in the synaptic cleft. The estimated area over which a quantum normally acts is less than 2mum2. 4. Post-synaptic receptors are not saturated by the ACh in a quantum, since the peak of the quantal response adds linearly to the response produced by an appropriate background concentration of ACh from a pipette. This conclusion is supported by the observation that upon inhibition of AChE the peak amplitude of the quantal current response increases by about 20% with no change in its time to peak. 5. It is suggested that post-synaptic potentiation between quanta may play a role in signalling at synapses in which non-linear dose-response characteristics have been observed and where transmitter is not as repidly inactivated as the neuromuscular synapse.


The number of transmitter molecules in a quantum: an estimate from iontophoretic application of acetylcholine at the neuromuscular synapse.

1. The sensitivity of the subsynaptic membrane of twitch muscles of the frog and snake to iontophoretically applied acetylcholine (ACh) was determined. Optimal placement of ACh micropipettes on to the postsynaptic membrane resulted in potentials that were similar, though not identical, to the miniature excitatory post-synaptic potentials (min e.p.s.p.s). A sensitive bio-assay was developed to measure the output of ACh from micropipettes; this allowed an estimate to be made of the upper limit of the number of ACh molecules in a quantum of transmitter that is released from the nerve to produce a min e.p.s.p. 2. The assay to calibrate the output of ACh from micropipettes used the end-plate of the snake muscle as an ACh concentration detector. The end-plate was situated within a few mum of an oil-water interface, and a 0-6 nl. droplet of Ringer solution containing a known concentration of ACh (1 muM or less) was formed in the oil phase. The droplet was brought to the interface and, upon touching it, discharged its contents into the Ringer phase immediately above the end-plate. This resulted in a membrane depolarization that was recorded with an intracellular microelectrode. By applying droplets containing various known ACh concentrations a standard curve was constructed. To measure the ACh output of micropipettes a 0-6 nl. droplet of Ringer solution was suspended in the oil. The ACh pipette tip was inserted into the droplet and several thousand pulses of ACh were then delivered. The ACh content of the test droplet was measured by comparing its effectiveness in depolarizing the end-plate with the standard curve. In this manner the number of ACh molecules released in a single pulse was determined as a function of charge passed through the pipette. The output of ACh was linear and an average of 30,000 molecules of ACh were released per pC. 3. The sensitivity of the subsynaptic membrane to iontophoretically applied ACh, using the linear slopes of dose-response curves, in preparations from frog and snake treated with anticholinesterases was usually about 5 mV/pC. It follows that 6000 molecules of ACh are sufficient to produce a depolarization of 1 mV in the subsynaptic membrane. 4. The mean min e.p.s.p.s of muscle fibres treated with anticholinesterase range from 1 to 3 mV. Since the ACh released from an iontophoretic pipette is less effective than the same amount released from the nerve, it is concluded that a quantum of transmitter consists of less than 10,000 molecules of ACh. 5. It is calculated that for each molecule of ACh released in a quantum there results a minimum net flow of 3000 univalent ions across the synaptic membrane.


Evidence against a physiological role of prostaglandins in the regulation of noradrenaline release in the cat spleen.

1. The effects of prostaglandins E2 (PGE2) and indomethacin on responses and on noradrenaline overflow elicited by nerve stimulation were studied in the perfused cat's spleen, at different calcium concentrations in the perfusion medium: 0-26, 0-65 and 2-6 mve stimulation and in the overflow of the transmitter. PGE2 was more effective in reducing transmitter overflow at 5 than at 30 Hz. 3. Indomethacin, 14-0 muM, prevented the release of PGE-like material in the venous effluent of the spleen elicited by either nerve stimulation or by exogenous noradrenaline. 4. During exposure to 14-0 muM indomethacin there was no increase in responses to nerve stimulation or in the overflow of noradrenaline elicited by nerve stimulation at 5 or at 30 Hz. 5. Similar results to those obtained with exogenous PGE2 and with indomethacin in the presence of 2-6 mM calcium, were observed when the experiments were carried out in the presence of either 0-65 or 0-26 mM calcium. 6. In the presence of the alpha-adrenoceptor blocking agents, phenoxybenzamine (2-9 muM) or phentolamine (3-1 muM), the increase in transmitter overflow obtained during stimulation was 6-5 and 8-3-fold respectively. 7. Since inhibition of the synthesis of PGE did not increase transmitter overflow during nerve stimulation, it appears that the proposed negative feed-back mechanism mediated by endogenous prostaglandins does not play an important physiological role in the regulation of adrenergic neurotransmission in the cat spleen. In this tissue the major endogenous negative feed-back regulatory mechanism is triggered by the neurotransmitter through the activation of prejunctional alpha-adrenoceptors.


Disturbed wards--do we need them?

This is a study of forty-three female residents of a continued care state psychiatric facility who were transferred from a ward for highly disturbed persons to a ward based on a geographical unit system. One year after the transfer thirty-eight patients were improved, particularly in the area of behavior symptomatology. A change in perceived expectations of both patients and staff seemed to be primarily responsible for the positive change noted.


The psychiatric nurse as outpatient psychotherapist.

Nursing therapy has predominantly reflected treatment within inpatient settings. There is little focus on outpatient services, where the psychiatric nurse can function as psychotherapist. Specific roles of one outpatient nurse therapist are outlined. Concrete guidelines in terms of supervision, support, and self-exploration are delineated for implementation by the nurse as outpatient psychotherapist.


Emergency discharges: their outcome.

This paper compares the short-term outcome of a group of seven patients released from an inpatient facility during an employee strike and a group of eight released at the optimal time according to the treating physicians. There was no difference in the outcome of the two groups, only two fifth of the entire cohort could be considered as doing well. The reasons for the findings are explored.


Consultation to groups in conflict: some aspects of group design.

1. One should carefully consider the broad dynamics and deal with one's own feelings in performing the consultation. One should resist any pull to act hastily in setting up a group. 2. It must be determined if a group would be helpful in dealing with the problem. Then one must ascertain the desire for a group experience at all levels of the nursing hierarchy. Membership in a group should be by choice and not because of obligation or coercion. 3. The boundaries of the group should be worked out after careful evaluation of the problem. This should include discussion with any potential participants about the desire for a group and about issues of membership and other boundary decisions such as time and place. If the boundaries and responsibilities of membership cannot be agreed upon by the consultant and members, then it is far more responsible not to conduct a group. 4. The task of the group should be defined and clear to the members and be consistent with the desired output of the group. In a group in conflict, there should be a defined primary task, that of dealing with any issues related to the understanding of this conflict. It follows that the role function os the consultant must be carefully defined. 5. To do effective work, the consultant must be seen as independent of the ward authority. One should consider with utmost caution any individual consultation with group members, as this may limit the consultant's effectiveness in dealing with the whole group. The consequences of allowing the ward authority to attend group meetings should be thought through carefully as this will greatly increase the complexity of any experience.


The hallucinating patient and nursing intervention.

This paper has been concerned with a patient's problematic behavior pattern, namely hallucinations. The social and dynamic significance of the behavior for the individual have been explored and analyzed and a formulation of possible developmental processes influencing the patient to utilize hallucinations has been discussed. On the basis of these analyses, formulations for a psychiatric nursing treatment plan of intervention have been presented. In conclusion, it is well to bear in mind that the schizophrenic patient, who is hallucinating, is striving to communicate in as clear and straightforward a way as he knows, the nature of his anxieties and experiences, despite how radically different they are from the nurse's, with speech content that is diffucult to follow. Thus, with this understanding, it behooves us as nurses to intervene accordingly and "decode" the hallucinated messages and thereby assist in breaking into the third stage in the evolutionary cycle of a psychosis, as cited by R.D. Laing: Stage 1 = Good (me); Stage 2 = Bad (me); Stage 3 = Mad (not me).


The effect of inhibition of prostaglandin synthesis on ovarian hypertrophy in the rat.

Aspirin and indomethacin, inhibitors of prostaglandin biosynthesis, were utilized to determine the role of prostaglandins (PGs) in ovarian weight gain in rats following unilateral ovariectomy or treatment with PMSG. After unilateral ovariectomy, the compensatory ovarian hypertrophy was 185-0% compared with 139-8% and 97-5% in rats treated with indomethacin and aspirin, respectively. The adrenal weights in rats treated with aspirin were also reduced significantly. Administration of PGE2 or PGF2alpha with aspirin reversed the effect of aspirin on the adrenals but had no effect on the ovarian weight. Indomethacin and aspirin treatment of animals injected with PMSG also reduced the ovarian weight gain. If 100 mug PGE2 were given twice daily, this effect was reversed in both groups but thrice daily administration had no effect on rats receiving aspirin. In PMSG-treated rats, 100 mug PGF2alpha twice daily did not reverse the effect of indomethacin and aspirin, and actually enhanced the effect of aspirin.