Association of osteopetrosis and vitamin D-resistant rickets.

The following report concerns a case of malignant osteopetrosis associated with hypocalcemic rickets unresponsive to vitamin D. Parathyroid hormone (PTH) and Calcitonin (CT) secretions were studied in basal conditions and under calcium gluconate infusion, before and after high doses of vitamin D. Basal values (PTH: 690 pg Eq/ml; CT: 560 pg/ml) were found to be much higher than in five control subjects of the same age group, even after vitamin D therapy (PTH: 990 pg Eq/ml; CT:450 pg/ml). Like rickets, PTH and CT secretions do not seem, therefore, to be notably influenced by vitamin D therapy.


Simultaneous occurrence of hypopituitarism and adrenal medullary insufficiency in a boy with hypoglycemia.

The case of a 6-year-old mentally retarded boy is described, who was delivered by breech presentation and who was later found to have adrenal calcifications. He presented with severe hypoglycemia during infancy and early childhood. Subsequent examinations revealed the coexistence of pituitary growth hormone and ACTH-deficiency and of adrenal medullary insufficiency. The hypothalamus-pituitary-thyroid and -gonadal axes were apparently normal. It is concluded that both, the pituitary and adrenal medullary insufficiency are probably due to the same complications at birth (hypothalamic or pituitary asphyxia and adrenal hemorrhage) and that both conditions contributed to the development of hypoglycemia.


Inhibition of converting enzyme activity by acute hypoxia in dogs.

We studied the effect of a change in oxygen tension on converting enzyme activity in anesthetized, paralyzed, catheterized dogs ventilated with room air, 100% O2, and hypoxic gas mixtures. Bradykinin was continuously infused into the femoral vein and simultaneous samples drawn from the pulmonary artery and left atrium; bradykinin was extracted into ethanol and measured by radioimmunoassay. Clearance of bradykinin by lung converting enzyme decreased from 96% at PaO2 levels above 95 Torr to 0% below 26 Torr. Inhibition of enzyme activity was rapid in onset (less than 2 min), closely correlated with PaO2 (r = 0.92, P less than 0.001), and reversible within 2 min after return to room air breathing. Converting enzyme activity of the systemic vascular bed was also inhibited by hypoxia; kininase I activity was unaffected by oxygen tension. Although arterial bradykinin concentrations in the range of 0.5 ng/ml produced hypotension in normoxic animals, elevations to 30 ng/ml had no hypotensive effect in hypoxic dogs. During acute hypoxia, venous bradykinin will pass through the lung unmetabolized, and local levels of angiotensin II and bradykinin will vary in vascular beds with different oxygen tensions, providing a finely-graded mechanism for blood flow regulation.


Effect of intrapulmonary hematocrit maldistribution on O2, CO2, and inert gas exchange.

The potential effect of intrapulmonary variations in hematocrit on gas exchange has been studied in theoretical models of the lung containing maldistribution of both hematocrit (Hct) and ventilation-perfusion (VA/Q) ratio. Hematocrit inequality enhanced gas exchange when units of low VA/Q were given a low Hct, arterial PO2 rising by as much as 14 Torr and PCO2 falling by up to 2 Torr depending on the particular distributions of Hct and VA/Q, whereas gas exchange was depressed when units of low VA/Q had a high Hct. After measuring inert gas solubilities in both dog and human blood of different Hct, the effect of Hct inequality on inert gas exchange was similarly assessed. Solubility was found to increase with HCT for less soluble gases. Because of this, conditions for enhancement of inert and O2 exchange by HCt inequality coincided, and it was found that in general the effects on O2 and inert gas transfer were quantitatively internally consistent. Even when Hct inequality was extreme, the resulting perturbation of inert gas concentrations was sufficiently small that the main features of the recovered VA/Q distributions were unaltered.


Susceptibility of different gases to ventilation-perfusion inequality.

Calculations of O2 and CO2 transfer in lung models of both series and parallel ventilation-perfusion (VA/Q) inequality have been performed by several investigators. In some cases, O2 uptake was found to be depressed more than CO2 output but in other examples CO2 elimination was interfered with to a greater extent. To understand the fundamental basis of differential susceptibility of various gases to VA/Q inequality, an algebraic analysis of inert gas exchange in two-compartment models of both series and parallel inequality is presented. For both types of inequality, the result is remarkably simple, in that the gas most affected is one whose partition coefficient is the geometric mean of the ventilation-to-perfusion ratios of the two compartments. Transfer of O2 and CO2 in these models was predicted well by the inert gas results not only qualitatively but even quantitatively. Similarly good quantitative predictions were obtained in more complicated multicompartment VA/Q distributions. The results therefore explain and reconcile the findings of various reported studies and in particular account for the observation that CO2 transfer is compromised in many examples of series inequality.


Rotaviral diarrhea in pigs: brief review.

Rotavirus is a name given to a group of viruses that have similar characteristics and are generally capable of causing diarrhea in the young. Infection of pigs with porcine rotavirus is common and widespread and can result in diarrhea, especially in 1- to 4-week-old pigs. This virus is frequently associated with a diarrheal syndrome popularity known as "white scours," "milk scours," or "3-week-old scours." Pigs less than 1 week old are infrequently infected, presumably because of adequate passive immunity. The infection resembles enzootic transmissible gastroenteritis. Diagnosis can be made by immunofluorescent staining of mucosal scrappings from the small intestines.


The structure and ultrastructure of the renal tubule of the urodele amphibian, Amphiuma means.

The renal corpuscle and segments of the renal tubule of the urodele amphibian Amphiuma means have been described and studied by light and electron microscopy as a background for investigations on the effects of hormones, drugs, toxins and carcinogens on cell structure and function in long-term organ cultures of kidney explants. Notable features of the A. means kidney include the number and variety of cytoplasmic inclusions in the cells of the proximal segment, the comparatively thick glomerular filter, and the presence of possible renin granules in the endothelial cells lining the afferent arteriole near its point of entry to the glomerular capsule.


Analysis of fat-soluble vitamins. XXI. High pressure liquid chromatographic assay methods for vitamin D in vitamin D concentrates.

Two high pressure liquid chromatographic methods, a straight and a reverse phase system, were developed and compared with the official (chemical) AOAC method for vitamin D concentrates. The effects of the systematic error and the reproducibility of using an internal or external standard were studied, as well as the effect of using peak height or peak height X retention time for calculating the potential vitamin D content. A method is given for determining the conversion factor to calculate previtamin D as vitamin D. Based on the results of the comparison, the following conditions were selected for collaborative study: straight phase, amyl alcohol-hexane mobile phase, external standard, and calculation of potency by peak height.


"Self-catabolite repression" of pectate lyase in Erwinia carotovora.

The induction of pectate lyase of Erwinia carotovora was repressed by a high concentration of its inducer. The concomitant addition of cyclic adenosine 3',5'-monophosphate reversed this repression.


Transport of alpha-p-nitrophenylgalactoside by the lactose carrier of Escherichia coli.

alpha-p-Nitrophenylgalactoside was found to be accumulated by the lactose transport-system of Escherichia coli. This fact may help to resolve the differences in the reported number of sugar binding sites of the lactose transport protein in nonenergized and energized membrane vesicles.


Lipid and lipopolysaccharide composition of Escherichia coli surface-altered mutants selected for resistance to levallorphan, tetracaine, and polymyxin.

Certain mutants of Escherichia coli with an altered permeability barrier have an essentially normal lipopolysaccharide, fatty acid, and phospholipid content, with a slight increase in the membrane protein:lipid ratio. The phospholipid metabolism of the lev and tec strains shows an abnormal response to growth in the selective agents levallorphan and tetracaine, respectively.


Purification and properties of acetate kinase from Acholeplasma laidlawii.

Acetate kinase (EC 2.7.2.1) was purified from Acholeplasma laidlawii cytoplasm by a combination of ammonium sulfate fractionation, gel filtration, diethylaminoethyl-cellulose chromatography, and affinity chromatography on 8-(6-aminohexylamino)-adenosine 5'-triphosphate conjugated to Sepharose 4B. The enzyme was composed of polypeptide chains of about 50,000 molecular weight as estimated from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Under nondenaturating conditions, apparent molecular weights between 64,000 and 130,000 were obtained, depending upon mainly the ionic strength of the test solution. The enzyme had a narrow specificity for phosphate acceptor acids, whereas both purine and pyrimidine nucleoside triphosphates were suitable phosphate donors. Na(+) and K(+) inhibited both acetyl phosphate and adenosine 5'-triphosphate synthesis, and the latter was also inhibited by high concentrations of adenosine 5'-diphosphate and acetyl phosphate. This substrate inhibition was partially abolished by 0.5 M NaCl. The enzyme catalyzed the independent adenosine 5'-diphosphate<-->adenosine 5'-triphosphate and acetate<-->acetyl phosphate exchanges. The rate of the latter was enhanced by the addition of cosubstrate Mg(2+)-adenosine 5'-triphosphate. The high affinity for substrates, except for acetate, indicated that under physiological conditions the direction of the enzymic reaction favors adenosine 5'-triphosphate synthesis. Thus, a mechanism for adenosine 5'-triphosphate generation in mycoplasmas is suggested.


High and selective resistance to mecillinam in adenylate cyclase-deficient or cyclic adenosine 3',5'-monophosphate receptor protein-deficient mutants of Escherichia coli.

Adenylate cyclase-deficient (cya) mutants of Escherichia coli K-12 were selectively and highly resistant to mecillinam (FL1060) among several beta-lactam antibiotics in the absence of cyclic adenosine 3',5'-monophosphate (cAMP). They became sensitive to the drug in the presence of cAMP. Also, cAMP receptor protein-negative (crp) mutants, with the exception of strain 5333, were highly resistant to mecillinam in the presence and in the absence of cAMP. Mecillinam exerted two distinct and sequential effects in both cya+ strains and cya strains supplemented with cAMP: (i) rounding of cells and (ii) cessation of cell division. The first effect was accompanied by a decrease in growth rate, whereas the second effect was accompanied by enlargement and lysis of the rounded cells. The second effect of mecillinam was dependent on inoculum size and cAMP. When the cell density was above about 10(6) cells per ml, the rounded cells stopped dividing but did not lyse. In the absence of cAMP, cya strains neither stopped dividing nor lysed; they were resistant to the second, lethal effect of mecillinam.


Diglyceride kinase mutants of Escherichia coli: inner membrane association of 1,2-diglyceride and its relation to synthesis of membrane-derived oligosaccharides.

Mutants of Escherichia coli defective in diglyceride kinase contain 10 to 20 times more sn-1,2-diglyceride than normal cells. This material constitutes about 8% of the total lipid in such strains. We now report that this excess diglyceride is recovered in the particulate fraction, primarily in association with the inner, cytoplasmic membrane. The diglyceride kinase of wild-type cells was recovered in the same inner membrane fractions. The conditions employed for the preparation of the membranes did not appear to cause significant redistribution of lipids and proteins. The biochemical reactions leading to the formation of diglyceride in E. coli are not known. To determine whether diglyceride formation requires concurrent synthesis of the membrane-derived oligosaccharides (H. Schulman and E. P. Kennedy, J. Biol. Chem. 252:4250-4255, 1977), we have constructed a double mutant defective in both the kinase (dgk) and phosphoglucose isomerase (pgi). When oligosaccharide synthesis was inhibited in this organism by growing the cells on amino acids as the sole carbon source, the diglyceride was no longer present in large amounts. When glucose was also added to the medium, the pgi mutation was bypassed, oligosaccharide synthesis resumed, and diglyceride again accumulated. These findings suggest that diglyceride may arise during the transfer of the sn-glycero-1-P moiety from phosphatidylglycerol (and possibly cardiolipin) to the oligosaccharides. In wild-type cells the kinase permits the cyclical reutilization of diglyceride molecules for phospholipid biosynthesis.


The use of multivariate personality strategies in predicting attrition from alcoholism treatment.

This study attempted to replicate previous work which used discriminant analysis to predict attrition from an outpatient alcoholism treatment program. The MMPI-168 and Rotter's locus of control scale were administered to a sample of inpatient male alcoholics who later entered outpatient treatment. The MMPI-168 was scored using 5 factor-analytically derived measures, Depression, Somatization, Low Morale, Psychotic Distortion and Acting Out. Both studies found Depression to be the strongest predictor of attrition after controlling for Somatization. Internal locus of control was also related to attrition. The utility of discriminant analysis in predicting outcome from personality data and the ramifications for treatment is discussed.


Interaction of iodinated human [D-Ala2]beta-endorphin with opitate receptors.

The interaction of beta-endorphin with opiate receptors was studied by using the radioiodinated, metabolically stable D-Ala2 derivative of human beta-endorphin. This analog binds specifically to rat brain membrane preparations with an apparent Kd of about 2.5 x 10-9 M. The ability of various enkephalin analogs, as well as opiate agonists and antagonists, to inhibit the binding of beta-endorphin clearly demonstrates that this peptide can bind to opiate receptors. However, the effects of various cations on the binding of 125I-[D-Ala2]beta-endorphin are markedly different from those found for enkephalin binding. Sodium ion at physiological concentrations decreases substantially the binding of enkephalins but only slightly decreases endorphin binding, whereas manganese enhances enkephalin binding but has no effect on endorphin binding. Moreover, potassium (100 mM) decreases the binding of beta-endorphin but does not affect enkephalin binding. These results suggest that beta-endorphin and enkephalin bind differently to the same receptor or bind to different receptors with overlapping specificity.


The fate of cytoplasmic vanadium. Implications on (NA,K)-ATPase inhibition.

The fate of vanadate (+5 oxidation state of vanadium) taken up by the red cell was studied using EPR spectroscopy. The appearance of an EPR signal indicated that most of the cytoplasmic vanadate is reduced to the +4 oxidation state with axial symmetry characteristic of vanadyl ions. The signal at 23 degrees C was characteristic of an immobilized system indicating that the vanadyl ions in the cytoplasm are associated with a large molecule. [48V]Vanadium eluted with hemoglobin when the lysate from Na3[48V[O4-treated red cells was passed through a Sephadex G-100 column and rabbit anti-human hemoglobin serum caused a hemoglobin-specific precipitation of 48V when added to the red cell lysate. Both results indicate that hemoglobin is the protein which binds cytoplasmic vanadyl ions. However, neither sodium vanadate nor vanadyl sulfate bound to purified hemoglobin in vitro. Finally, transient kinetics of vanadyl sulfate interaction with the sodium-and potassium-stimulated adenosine triphosphatase showed that the +4 oxidation state of vanadium is less effective than the +5 oxidation state in inhibiting this enzyme. These results indicate that oxidation-reduction reactions in the cytoplasm are capable of relieving vanadate inhibition of cation transport.


The hydrolysis of cholesterol esters in plasma lipoproteins by hormone-sensitive cholesterol esterase from adipose tissue.

Adipose tissue contains a high level of neutral esterase active against emulsions of cholesteryl oleate. The present studies show that this enzyme can also effectively hydrolyze the cholesterol esters in native rat plasma high density lipoproteins (HDL) and low density lipoproteins (LDL). The hydrolysis of lipoprotein cholesterol esters by a pH 5.2 isoelectric precipitate fraction from the freshly prepared 100,000 X g supernatant of chicken adipose tissue was low, but increased more than 50-fold on activation with cyclic AMP-dependent protein kinase. Rat adipose tissue homogenates were also very active against lipoprotein cholesterol esters, hydrolyzing as much as 60% of the total labeled cholesterol ester in HDL or LDL in 1 h. Activity was optimal at pH 7 and very low at pH 4. No protease activity was detected at pH 7 and, since assays were done in 2 mM EDTA, phospholipase A activity was presumably negligible. The results show that hormone-sensitive cholesterol esterase of adipose tissue has ready access to the neutral lipid core of plasma lipoproteins, either because the enzyme penetrates the polar shell or because the cholesterol ester in the core is exposed, at least intermittently, to allow enzyme-substrate complex formation. Whether or not this enzyme activity plays a role in lipoprotein degradation by adipose tissue remains to be determined.


Succinic semialdehyde dehydrogenase. Reactivity of lysyl residues.

The enzyme succinic semialdehyde dehydrogenase from pig brain has been 2000-fold purified by a combination of DEAE-cellulose, hydroxyapatite, and AMP-Sepharose chromatography. This preparation has a molecular weight of 160,000 and a specific activity of 5.3 mumol/min.mg at 25 degrees C. The inhibition of succinic semialdehyde dehydrogenase by carbonyl compounds, i.e. P-pyridoxal and o-phthalaldehyde was investigated in detail. The enzyme is reversible, inhibited by preincubation with P-pyridoxal (mixing molar ratio, 300:1) at either 25 degrees or 37 degrees C. Reduction with NaBH1 results in the incorporation of approximately 4 mol of P-pyridoxyl residues/mol of enzyme. NAD+ protects the enzyme against inactivation by P-pyridoxal, whereas the substrate succinic semialdehyde failed to prevent the reaction of P-pyridoxal with lysine residues of the protein. The binding of approximately 10 mol of o-phthalaldehyde/mol of enzyme results in irreversible loss of catalytic activity. The reaction is fast and easily monitored by absorption and fluorescence spectroscopy.


Initiation of RNA synthesis in vitro by vesicular stomatitis virus. Role of ATP.

The ATP requirement during RNA transcription by the RNA-dependent RNA polymerase associated with purified vesicular stomatitis virus was studied during chain initiation and chain elongation steps. Initiation of transcription in vitro has an apparent Km for ATP of approximately 500 micron, whereas the apparent Km for ATP during chain elongation is almost identical with those for the other three ribonucleoside triphosphates, i.e. 20 to 30 micron. Further analysis of the transcription process demonstrated that the beta-gamma imido analogue of ATP cannot be used for the initiation step. However, it can be incorporated into RNA during chain elongation. These results indicate that a hydrolyzable form of the beta-gamma phosphodiester bond in ATP is required for the initiation process and also support the hypothesis for a single promoter site for the initiation of transcription on the genome of vesicular stomatitis virus.


Reconstitution of lipid vesicles associated with HVJ (Sendai virus) sikes. Purification and some properties of vesicles containing nontoxic fragment A of diphtheria toxin.

A mixture of HVJ (Sendai virus) spike proteins, the nontoxic fragment A of diphtheria toxin, lecithin, and cholesterol was solubilized in sucrose solution containing a nonionic neutral detergent. The liposomal vesicles which formed on removal of the detergent by dialysis were purified by gel filtration and centrifugation on a sucrose gradient. The resulting purified vesicles had hemagglutinating activity, hemolytic activity and, after solubilization, the enzymic activity of fragment A. The vesicles had no cell fusion activity. Electron microscopy showed that both the outside and inside of membranes of the vesicles were associated with the spikes. When the vesicles were freeze-fractured, no large aggregates of particles were seen on either face. Such fragment A-containing lipid vesicles (liposomes) with HVJ spikes bound to mamalian cell membrane and released their fragment A into the cytoplasm causing cell death. Neither fragment A-containing liposomes without spikes nor empty liposomes with spikes were toxic.


Hormonally induced cell shape changes in cultured rat ovarian granulosa cells.

Cultured rat ovarian granulosa cells undergo a dramatic morphological change when exposed to follicle-stimulating hormone (FSH). Exposure to FSH causes the flattened epithelioid granulosa cells to assume a nearly spherical shape while retaining cytoplasmic processes which contact the substrate as well as adjacent cells. This effect of FSH is preceded by a dose-dependent increase in intracellular cAMP, is potentiated by cyclic nucleotide phosphodiesterase inhibitors, and is mimicked by dibutyryl cAMP. Prostaglandins E1 or E2 and cholera enterotoxin also cause the cells to change shape. A subpopulation of the cells responds to luteinizing hormone. These morphological changes, which are blocked by 2,4-dinitrophenol, resemble those produced by treating cultures with cytochalasin B. Electron microscopy shows that the unstimulated, flattened cells contain bundles of microfilaments particularly in the cortical and basal regions. After FSH stimulation, microfilament bundles are not found in the rounded granulosa cell bodies but they are present in the thin cytoplasmic processes. These data suggest that the morphological change results from a cAMP-mediated, energy-dependent mechanism that may involve the alteration of microfilaments in these cells.


Calcium-binding modulator protein from the unfertilized egg of the sea urchin Arbacia punctulata.

We have purified and partly characterized a calcium-binding protein from the unfertilized egg of the sea urchin Arbacia punctulata. This protein closely resembles the calcium-binding modulator protein of bovine brain in its molecular weight, electrophoretic mobility, amino acid analysis, and peptide map. It activates bovine brain phosphodiesterase in the presence of calcium but has no effect on the phosphodiesterase of the Arbacia egg. Densitometric scanning of acrylamide gels of arbacia egg homogenates shows the modulator protein to represent 0.1% of the total protein of the egg. At 10(-4) M free calcium, the protein binds four calcium ions per 17,000-dalton molecule. We have used a column of rabbit skeletal muscle troponin-I covalently coupled to Sepharose 4B as an affinity column to selectively purify the Arbacia egg calcium-binding protein. This column has also been used to purify bovine brain modulator protein and may prove of general use in isolating similar proteins from other sources. The technique may be particularly helpful when only small quantities of starting material are available.


Lipid-saccharide intermediates and glycoprotein biosynthesis in a temperature-sensitive Chinese hamster cell mutant.

The characterization of a temperature-sensitive Chinese hamster cell mutant has been continued with the aim of localizing the apparent defect in glycoprotein synthesis (Tenner et al., '77). Although the mutation is lethal, a demonstration of the ability of the mutant cells to support proliferation of Mengo virus at the nonpermissive temperature indicates that the general metabolic processes of the cells remain intact at a time when glycoprotein synthesis is severely depressed. A quantitative study of protein synthesis on membrane-associated polysomes suggests that the synthesis of the polypeptide portion of the glycoproteins at 40.8 degrees C may be normal. The investigation of lipid-saccharide molecules which have been implicated in the formation and transfer of the oligosaccharide "core" to polypeptide acceptors shows that mutant cells at the nonpermissive temperature are capable of synthesizing these lipid saccharides normally, and that the pool of the dolichyl oligosaccharides is maintained at a constant level independent of the temperature. The rate of formation of the lipid-oligosaccharide, however, is reduced in intact mutant cells at the nonpermissive temperature. Further investigations show this decreased rate to be the result of an increased half life of the lipid-oligosaccharide at 40.8 degrees C. These data indicate that the temperature-sensitive step in glycoprotein biosynthesis is the transfer of the oligosaccharide core from the lipid-oligosaccharide intermediates to the nascent polypeptide chain. The data presented also provide evidence that the lipid-saccharide intermediates, previously described mainly in in vitro systems, are in fact involved in the glycosylation of a majority, if not all, of the mannose-containing glycoproteins in intact, growing hamster cells.


Production of serum proteins in normal diploid fibroblast-hepatoma cell hybrids and in A9-normal liver cell hybrids.

Two series of interspecific hybrids have been generated between liver cells (which actively secrete several serum proteins) and fibroblasts (which do not). In each series, one of the parental cells was a normal diploid cell: mouse hepatoma cells were fused with normal diploid rat fibroblasts, and normal rat liver cells were fused with mouse fibroblasts of the permanent line A9. The production of albumin, alpha-fetoprotein (AFP) transferrin and the third component of complement (C3) was analysed in these hybrids. Most hepatoma cell hybrids exhibit extinction of albumin, AFP and (to a lesser extent) transferrin; they retain the capacity to secrete C3. Normal liver cell hybrids are also characterized by the absence of albumin and transferrin production and by retention of C3 secretion. These results, when compared to previous results obtained with hybrids derived exclusively from different differentiated cells of permanent and transformed lines show that the phenotype of such hybrids is not determined by the abnormal character per se of the aneuploid parental cells. Amongst the rat fibroblast-mouse hepatoma cell hybrids, a few clones retain the capacity to actively secrete mouse albumin, AFP and transferrin, without the concomitant production of the rat serum proteins. These hybrids have lost more rat (fibroblast) chromosomes than the other clones and also have an increased number of mouse (hepatoma) chromosomes. Thus, their phenotype must result from either the complete loss of 'extinguisher' chromosomes, or gene dosage effects. The significance of the lack of rat serum protein production is also discussed, and it is suggested that retention, without concomitant activation, could be explained in terms of diffusible regulators and heritable differences in chromatin conformation.


Action of a slowly hydrolysable cyclic AMP analogue on developing cells of Dictyostelium discoideum.

Adenosine 3',5'-cyclic phosphorothioate (cAMP-S) is a cyclic AMP (cAMP) analogue which is only slowly hydrolysed by phosphodiesterases of Dictyostelium discoideum. The affinity of cAMP-S to cAMP receptors at the cell surface is only one order of magnitude lower than that of cAMP. cAMP-S can replace cAMP as a stimulant with respect to all receptor-mediated responses tested, including chemotaxis and the induction of cAMP pulses. cAMP-S does not affect growth of D. discoideum but it blocks cell aggregation at a uniform concentration of 5 x 10(-7) M in agar plate cultures of strain NC-4 as well as its axenically growing derivative, Ax-2. Another wild-type strain of D. discoideum, v-12, is able to aggregate on agar plates supplemented with 1 mM cAMP-S. The development of Polysphondylium pallidum and P. violaceum is also highly cAMP-S resistant. In Ax-2 both differentiation from the growth phase to the aggregation-competent stage and chemotaxis are cAMP-S sensitive, whereas in v-12 only chemotaxis is inhibited. v-12 can still form streams of cohering cells and fruiting bodies when chemotaxis is inhibited by cAMP-S. Whereas cAMP induces differentiation into stalk cells at concentrations of 10(-3) or 10(-4) M, cAMP-S has the same effect in strain v-12 at the much lower concentration of 10(-6) M.


Pseudocorpus luteum insufficiency: a local defect of progesterone action on endometrial stroma.

A 23-yr-old woman whose initial complaint was infertility demonstrated glandular stromal dissociation with failure of the endometrial stroma to undergo pseudodecidualization in repeated endometrial biopsies taken late in the luteal phase. As the clinical presentation was consistent with the inadequate corpus luteum syndrome, hormone measurements were performed. The endometrial biopsy was abnormal during cycles in which the serum pattern of progesterone, estradiol, FSH, and LH was normal. Exogenous progesterone did not correct the abnormality. The patient, by in vitro studies, has approximately one half the number of high affinity progesterone-binding sites in the cytosol fraction of her endometrium compared to preparations from two normal control subjects. Since her cytosol-binding protein was qualitatively identical to two control subjects, the incomplete maturation of her endometrial stroma may represent an absence or reduced number of stromal cytosol receptors and/or a resistance to specific hormone action in an individual target tissue.


Heterogeneity of the human chorionic gonadotropin alpha-subunit secreted by cultured choriocarcinoma (JEG) cells.

The cultured human choriocarcinoma cell line, JEG-clone 3, secretes substantial quantities of both biologically active hCG and an immunoreactive alpha-subunit (JEG-alpha). This study is concerned with a comparative characterization, using RIA, of the chromatographic properties (via gel exclusion and isoelectric focusing) of JEG-alpha and standard urinary hCG-alpha. Most of the molecules comprising the JEG-alpha fraction have an apparent molecular weight greater than that of hCG-alpha. Both hCG-alpha and JEG-alpha exhibit heterogeneity on electrofocusing. However, JEG-alpha contains a major component with an isoelectric pH (pI) of 4.8; this is a minor component, if present at all, in hCG-alpha. The JEG-alpha pI 4.8 component chromatographs with an apparent molecular weight greater than hCG-alpha, while a minor JEG-alpha pI 7.0 component chromatographs with an apparent molecular weight similar to that of the standard. Heterogeneity is expected in the carbohydrate moieties of the glycoprotein hormone subunits. Results of studies on the incorporation of 14C- and 3H labeled amino acids into JEG-alpha suggest that heterogeneity also exists in the protein moiety of JEG-alpha. An interesting possibility is that the form(s) of JEG-alpha with larger apparent molecular weight represents a precursor of the alpha-subunit used to form hCG.


Adrenocorticotropin-cortisol axis abnormalities in hemodialysis patients.

The ACTH-cortisol axis was studied in 15 hemodialysis patients. Basal plasma cortisol concentrations were found to be elevated and ACTH to be in the high normal range. Cortisol responded normally to exogenous ACTH, but neither cortisol nor ACTH were suppressed in response to oral dexamethasone. 11-Deoxycortisol and ACTH concentrations did not rise normally in response to either oral or iv metyrapone. We conclude that standard testing of the ACTH-cortisol axis in dialysis patients yields results suggesting Cushing's syndrome.


Enzyme-linked immunosorbent assay for detection of antibodies to influenza A and B and parainfluenza type 1 in sera of patients.

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to influenza A/Hong Kong/1/68, influenza A/Victoria/3/75, influenza B/Hong Kong/5/72, and parainfluenza type 1 viruses. Development and standardization of the method indicated that an acetone-ethyl alcohol mixture was a suitable fixative for the preparation of the solid-phase coupled antigen. The addition of sodium azide to the enzyme-conjugated solution and the concentrations of the enzyme-conjugate antiglobulin and test sera employed were all critical factors in the success of the ELISA procedure. The ELISA test was specific; there was no cross-reaction between influenza A and B or parainfluenza type 1 viruses. The concordance between ELISA and hemagglutination inhibition results suggested that both tests probably detected the same type of antibodies. The ELISA procedure was 8 to 64 times more sensitive than complement fixation and/or hemagglutination inhibition tests. Low levels of antibody in patients' sera were detected only by the ELISA test. During the course of the testing period false positive reactions were not encountered. The results of ELISA could be obtained within 3 h. The ELISA test required a very small amount of serum and, therefore, offered an opportunity to detect the presence of maternal antibodies to influenza viruses in blood collected from infants by heel prick.


Antibody to varicella-zoster virus after passive immunization against chickenpox.

Antibody titers to varicella-zoster virus were measured in varicella-susceptible immunocompromised children 48 h after they received either one of two lots of zoster immune globulin (ZIG) or a selected lot of immune serum globulin (ISG). Globulin was given to modify varicella in these children after exposure to varicella or zoster. Indirect immunofluorescence antibody titers (FAMA) of children after receipt of globulin ranged from less than 1:2 to 1:32. Geometric mean FAMA titers were highest after 1.2 ml of ISG per kg (FAMA titer 1:128) and 0.16 ml of ZIG lot A per kg (FAMA titer 1:1,024). Selected batches of ISG titering 1:128 or greater by FAMA, at a dose of 1.2 ml/kg, may be used to attempt to modify varicella in susceptible high-risk individuals when ZIG is not available.


The use of iodolipids in hepatosplenic computed tomography.

Iodolipids have been used as a contrast medium for hepatosplenic computed tomography (CT) in 148 patients. In all but two of these cases, the contrast material was injected by the intravenous route. The method appears to be safe due to the marked reduction of dosage in CT compared with conventional radiographic iodolipid hepatography. This decreased dosage is made possible by the improved density and spatial resolution of CT. Pictorial and histographic densitometric analysis of normal and abnormal liver after iodolipid administration yields considerable diagnostic improvement.


Development and experimental evaluation of a contrast medium for computed tomographic examination of the liver and spleen.

A lipoid based contrast material containing 53% of ethiodized oil in emulsion form was developed for computed tomography (CT) of the liver and spleen and tested in rabbits and monkeys. An intravenous dose of 0.2 ml/kg selectively opacified the liver and spleen, resulting in an average increase of 23 EMI units (500 scales) in the attenuation of the liver and a higher increase in the attenuation of the spleen. When injected into rhesus monkeys with carcinogen induced hepatomas there was a significant improvement in the visualization of the tumor, and small lesions, undetectable on the preliminary CT scan, became visible. Toxicity studies are in progress.


Primary malignant fibrous histiocytoma of skin.

Three fibrous histiocytomas, primary in skin, were studied by light and electron microscopy and by frozen section histochemistry. The term malignant was applied to cutaneous tumors which demonstrated aggressive multinodular local growth, including angioinvasion and/or extension into bone, muscle, and fascia. Metastases were not found. Strongly positive reactions for hydrolytic enzymes, particularly acid phosphatase will help differentiate malignant fibrous histiocytoma from most other primary soft tissue malignancies of skin. Electron microscopic studies reaffirm the presence of both histiocyte-like and fibroblast-like cells. Langerhans' granules were not identified. Primary malignant fibrous histiocytoma of skin may have a prognosis superior to homologous tumors arising in deeper soft tissue and the retroperitoneum.


Adrenal responsiveness in pre- and postpartum dairy cows.

Adrenal responsiveness was evaluated by injecting 10 multiparous dairy cows with 200 IU adrenocorticotropin between -13 and -2 days prepartum (I) and postpartum between 24 and 40 h (II) and 21 and 24 days (III). Concentrations of glucocorticoids following injection were influenced by day of injection, temperature, and minimum percent relative humidity but not by breed, breed X injection day interaction, or age of cow. Likewise differences in regressions for adrenal response and mean response (ng/ml) for the three injections were nil. Mean concentrations at peak (45, 60, and 120 min postinjection samples) adjusted for preinjection concentrations also did not differ for the three periods of injection. Mean concentrations of glucocorticoids in plasma for daily samples between -13 and -2 days prepartum were 5.3 +/- .4 (n = 61), reached a peak of 14.8 +/- .3 ng/ml the day of calving, and remained high for 2 days postpartum. Estradiol increased through prepartum sampling from 23.3 to 339.6 +/- 94.1 pg/ml the day of calving, then declined abruptly. Progestins began to decline about -5 days prepartum from mean concentration of 4.09 +/- .62 (n = 25) and attained low concentrations (.30 +/- .06 ng/ml) 2 days postpartum. Although there was a surge of glucocorticoids at parturition, this was not associated with a modification in adrenal responsiveness or with prepartum concentrations of other steroid hormones of plasma. Adrenal potential in prepartum and postpartum dairy cows appears well maintained.


Effects of 3-hydroxy-3-methylglutaric acid on plasma and low-density lipoprotein cholesterol levels in familial hypercholesterolemia.

Different doses of 3-hydroxy-3-methyl-glutaric acid (HMG) on plasma lipids were studied in a double-blind trial in 36 patients with familial hypercholesterolemia (type IIa or hyper-beta-lipoproteinemia). The patients were randomly assigned to five groups, and each group received one of the following treatments: placebo, or HMG 750 mg, 1500 mg, 2250 mg, or 3000 mg per day. As compared to placebo, the mean plasma cholesterol levels during the eight-week treatment period were 11 and 13 per cent lower in the 2250-mg and 3000-mg HMG-treated groups (P less than 0.034 and less than 0.021, respectively). At the same dosage levels LDL cholesterol was decreased by 8 per cent. HMG had no significant effect on plasma triglycerides as compared to placebo. Discontinuation of the medication did not result in a rebound of plasma cholesterol. There were no clinical or biologic adverse effects due to the administration of HMG, and all patients maintained excellent compliance to the medication. Because of its lack of toxicity, HMG may be useful as an adjunct to diet in the treatment of familial hypercholesterolemia.


The fate of amalgam implanted in soft tissues -- an experimental study.

The soft tissue reaction to amalgam depended on whether it was finely ground or a solid mass. Finely ground amalgam was actively digested within macrophages and giant-cells with loss of mercury and the formation of the fine particles of silver and sulphur. Larger masses became surrounded by a fibrous capsule.


Quantitation of mitochondrial DNA and protein in the liver of Fischer 344 rats during aging.

Mitochondria from liver whole homogenates of Fischer 344 rats, 3,6, 12 and 24 mo of age were separated by reorienting rate-zonal centrifugation on sucrose gradients. Employing this method, mitochondria can be harvested nearly quantitatively and subjected to a number of biochemical analyses. Separation and recovery of the mitochondria from young and old rats was monitored by assaying each fraction from the gradient for cytochrome oxidase and lipoamide dehydrogenase, two mitochondrial specific enzymes. In addition, several regions of the gradient were studied by transmission electron microscopy. In this study, mitochondrial DNA and protein were quantitated from the livers of the animals at each age group. It was demonstrated that between the ages of 12 and 24 mo these macromolecules decreased significantly. These data would seem to indicate that the number of mitochondria is decreased in this tissue in aged animals.


An unusual complication following surgical treatment of deQuervain's disease.

Symptoms of deQuervain's disease were relieved by incision of the first dorsal compartment sheath in a 43-year-old hospital employee. Three months after the operation she developed dysaesthesias in the distribution of the superficial radial nerve with wrist extension and thumb abduction. At reoperation the tendons of the first dorsal compartment were found to glide dorsally onto a fibrous remnant of the sheath and to elevate the overlying superficial radial nerve. Excision of the fibrous ridge resulted in relief of symptoms. The complication could have been avoided, in retrospect, by excising the sheath or by incising it at its dorsal attachment.


Syndactyly with Larsen's syndrome.

The association of syndactyly with Larsen's syndrome is reported. A revised listing of syndromes which may be associated with syndactyly is presented.


Coping with cancer through self-instruction: a hypothesis.

Because most cancer patients seem to cope well with the stresses of their illness, including the psychosocial ramifications, it is important to understand what good copers manage to do, as opposed to those patients who simply defend themselves against persistent problems. This requires making a radical distinction between coping and defending, as well as between healthy adaptive resources and latent pathological dispositions. A case report is presented to illustrate how one "supercoper" solved problems by self-instruction. While cognitive self-instruction may not be applicable for every cancer patient and all problems, it is a working hypothesis deserving of further investigation, since self-control and personal responsibility are essential elements in rehabilitation on all levels. One intervention model for "high distress" cancer patients is outlined.


Enteric viruses in the Danube river water and sludge.

A study of the viral pollution of the Roumanian course of the Danube river was carried out from 1972 to 1974. The presence of enteric viruses was investigated in 123 water samples, taken by the gauze swab method and in 116 sludge samples from the bottom of the river. The samples were collected from 20 sampling points along the river from Moldova Veche to Brăila, in accordance with the water use and the main pollution sources. Viruses were recovered from 17.5% of the samples. The frequency of virus isolations from water samples was similar to that observed in sludge samples. Therefore, the viral pollution of the Romanian course of the Danube showed a low level in comparison with other rivers, though two concentration techniques into suckling mice and into tissue cultures, were used for each sample.


[The radio immune level of total serum oestriol during pregnancy. An examination of the method and comparison of the concentrations of total serum oestriol, non-conjugated serum oestriol and the excretion of total urinary oestrogens (author's transl)].

The authors report on a preliminary study of the level of total serum oestriol in the third trimester of pregnancy by the bundle method of estimating this with "oestriol 1251 RIA Kit" (Amersham, Buchler). The criteria on which the quality of the method depends, viz, sensitivity, specificity, reliability, and accuracy, together with its practicability are satisfactory. Correlations between total serum oestriol and free serum oestriol and total urinary oestrogens are good and correspond with those given in the literature. This method therefore can be used in clinical practice. All the same, it still has to be established which parameter better reflects the feto-placental state. Is it the free serum oestriol or the total serum oestriol?


Comparison of the efficiency of two methods for virus concentration from river water environment in a model experiment.

Two of the methodical approaches for detection of virus contamination of surface waters were experimentally tested, i.e., the method of adsorption of virus particles to an inorganic salt (CaHPO4)  and the ultrafiltration method using the Amicon apparatus. Under the given experimental conditions, the two methods showed practically identical factors of efficiency of virus concentration; the Danube river water proved to be a more suitable medium for the model of Coxsackie A4 virus than the physiological saline used as the control. In view of the feasibility, inexpensiveness and adequate effectivity of the precipitation method and with respect to good results obtained with it in field studies, the mentioned method of concentration could be recommended as the method of choice in field virological practice for aimed examination of surface waters.


Coxsackie A 13 virus in the foci of rheumatism.

Faeces and nasopharyngeal washing were examined in 12 patients and 27 contacts of these patients in family foci (primary foci) of rheumatism and in 37 patients and 32 contacts of these patients in secondary foci of rheumatism (in hospitals). Results of stimultaneous examinations of 127 children of the control groups served as the control. An analysis of the results of the investigation showed the Coxsackie A 13 virus was found considerably more frequently in both the patients (83.3%) and their contacts (148.1%) in the primary foci of rheumatism than outside these foci (11.9--15.3%). The difference is statistically significant. Wide distribution of Coxsackie A 13 virus was also observed in clinical departments in which children were hospitalized at the acute stage of rheumatism. We failed to establish marked differences in the rate of detection of other viruses in the foci of rheumatism in comparison with the control groups.


Production of toxic enzymes of Clostridium perfringens BP6K on technologically important media including a medium with Tween 80.

The addition of 0.05--0.1%  of Tween 80 to casein hydrolysate medium of Adams and Hendee raises and production of Clostridium perfringens BP6K lecithinase by approximately 50%. The use of the silicon antifoam Lukosan makes the medium particularly suitable for cultivation in large volumes. Higher levels of theta haemolysin and lecithinase are formed on the casein hydrolysate medium than on the meat medium. All factors except the theta and lambda components are farily stable during cultivation.


Purification of hepatitis A virus by affinity chromatography.

Hepatitis A virus was purified from faeces by immunoaffinity chromatography.


Epidermodysplasia verruciformis versus disseminated verrucae planae: is epidermodysplasia verruciformis a generalized infection with wart virus?

Recently it has been shown that epidermodysplasia verruciformis is induced by human papilloma/virus different from the papilloma/virus of warts, and that 2 distinct viruses-designated HPV-3 and HP-4--are responsible for it. Ten cases of epidermodysplasia verruciformis were found to have been caused by HPV-3. Clinically and histologically, as well as in the often depressed cell-mediated immunity they closely resembled long-standing verrucae planae, also caused by HPV-3. Contrariwise, in epidermodysplasia verruciformis caused by HPV-4 there are characteristic red, red-brown, and depigmented, pityriasis versicolor-like plaques, and malignant transformation seems almost inevitable. Cases due to HPV-3 may be abortive or even regressive, or stationary, and hard to distinguish from flat warts. No malignant conversion was seen in patients infected only with HPV-3, whereas it occurred in 2 patients infected with both viruses: HPV-3 and HPV-4. Pigmented plaques are the most important adverse prognostic sign in EV induced by HPV-3.


The effect of 8-methoxypsoralen-plus ultraviolet light on cell-virus interaction: the transforming infection; effect of PUVA on the transformation of baby hamster kidney cells by polyoma virus.

Pre-treatment of baby hamster kidney (BHK) cells with 8-methoxypsoralen (8-MOP) plus ultraviolet (UV) light enhances the frequency of their transformation by polyoma (Py) virus. Of the doses tested, 0.5 microgram/ml 8-MOP plus 0.3 J/cm2 UV-light results in maximal (30-fold) stimulation of viral transformation. 8-MOP alone does not affect viral transformation and UV-light alone causes only a slight increase in the transformation frequency. Thus the drug and light act synergistically in promoting the effect. Treatment of BHK cells with drug plus light without Py infection does not lead to a transformed morphology. A drug-light combination (0.01 microgram/ml 8-MOP plus 1.2 J/cm2 UV) that inhibits cellular DNA synthesis to 75% of control at 28 hr after treatment results in a 6-fold stimulation of the transformation frequency.


Serum proteins in heavily burnt patients.

Several serum proteins, such as prealbumin, protease inhibitors, immunoglobulins, metalloproteins and inflammatory glycoproteins were determined in the sera of heavily burnt patients by radial immunodiffusion. An increase of acute phase reactant glycoproteins (orsomucoid, haptoglobin, haemopexin, C-reactive protein), C3-complement, immunoglobulins, prealbumin and of the protease inhibitors (a1-antitrypsin, a2-macroglobulin) was found. For some proteins, such as prealbumin, haemopexin, immunoglobulins, this increase was preceeded by a decrease  on days 3 to 5 post-burn. The time course of the increase was variable, faster for some patients and slower for others: orosomucoid, C-reactive protein, C3-complement reached peak values between days 6 and 8; immunoglobulins and hemopexin decreased then towards normal values. No significant increase was found for ceruloplasmin, transferrin, beta2-glycoprotein, a2-SH glycoprotein and GC-globulin. It is proposed that the selective overproduction of the above mentioned proteins may be related to the stimulation of acute-phase reactant protein synthesis by the liver as a result of tissue breakdown produced by the circulating proteases and especially by elastases and collagenases as was shown previously (Miskulin et al., 1978; Moati et al., 1978a).


Study on the mutagenicity of conjugated estrogens in human, animal and bacterial systems.

Conjugated estrogens were studied for mutagenicity (and implied carcinogenicity) in two strains of S. typhimurium, two normal and three neoplastic human lymphoid cell lines (the latter from Burkitt's lymphoma patients) in cell culture and a Chinese hamster cell line in diffusion chambers implanted into mice. No significant increase in mutation rate or chromosome aberrations were noticed after exposure to conjugated estrogens.


Refractoriness of the pituitary gland after continuous exposure to luteinizing hormone releasing hormone.

The refractoriness of LH release by pituitary glands from intact female rats was studied during stimulation by luteinizing hormone releasing hormone (LH-RH), monobutyryl cyclic AMP+theophylline or potassium in vitro. Various concentrations of LH-RH (0.1, 0.3 and 10 ng/ml) all caused refractoriness within 24 h. Subsequent exposure to a supramaximally active concentration of LH-RH for 6 h also resulted in a depressed response; the degree of inhibition depended on the concentration of LH-RH to which the glands had been exposed previously. Glands made refractory to LH-RH also showed a depressed response to monobutyryl cyclic AMP+theophylline, although these agents by themselves were unable to induce refractoriness. Incubation in medium containing a high concentration of potassium also resulted in the release of LH, which in all respects was similar to that caused by LH-RH. Glands made refractory to LH-RH showed a decreased response to potassium and, conversely, the release of LH in response to LH-RH was reduced after exposure of glands to potassium. It is concluded that the LH releasing activity of LH-RH, which is mimicked by potassium, deteriorates during continuous exposure to the secretagogue.


A pigeon crop sac radioreceptor assay for prolactin.

Ovine prolactin, labelled with 125I by either lactoperoxidase or a mild chloramine T method, bound to receptors from the pigeon crop sac mucosa cells of prolactin-injected pigeons. Binding was demonstrated in a crude homogenate of mucosal cells removed from the crop by scraping and in a subcellular fraction in which 5'-nucleotidase activity was enhanced two- to threefold. The binding was specific, dependent on time, temperature and the concentration of receptors and had a dissociation constant of 7 X 10(-10) mol/l. The binding capacity of the crop tissue was 71 fmol/mg membrane protein. Nine purified preparations of prolactin from four species were assayed by local pigeon crop sac bioassay and by radioreceptor assay. The two methods were highly correlated (r = 0.934). The regression equation was radioreceptor assay = 1.22 bioassay--0.18 indicating a 1 : 1 correspondence between the two methods for prolactin purified from sheep, rat, horse and pig anterior pituitary glands.


A comparison of the borate-celite column screening technique with other extraction methods in forensic toxicology.

The comparison of five different extraction techniques from postmortem tissues was reported. The borate/celite column chromatography technique generally gave the best yields and its use as a screening method in forensic toxicology was discussed.


Effect of herpes simplex virus type 1 infection on the cellular DNA polymerase activities of mouse cell cultures.

Thymidine kinase-deficient mouse cell cultures infected with herpes simplex virus type 1 exhibited a maximum of virus DNA synthesis around 8 h post-infection as determined by pulse labelling with 3H-thymidine. Cellular DNA synthesis was progressively inhibited, but still appreciable until 8 h post-infection and not completely abolished at any time during the infectious cycle. Phosphonoacetic acid was found to be a potent and selective inhibitor of virus DNA synthesis only when added to infected cultures before the onset of virus DNA synthesis. During the interval of increasing virus DNA synthesis the activity of cellular alpha polymerase decreased rapidly, whereas the beta polymerase activity increased significantly; a slight increase was observed for the gamma polymerase activity. When infected cells were kept in the presence of phosphonoacetic acid following virus adsorption the effect on cellular DNA polymerases was less pronounced.


Excess of interfering over infectious particles in herpes simplex virus passaged at high m.o.i. and their effect on single-cell survival.

The capacity of herpes simplex virus to kill cells and to form both infectious centres and progeny virus was studied in cell culture. Two virus stocks were compared at various m.o.i.: (i) a standard virus stock and (ii) a stock which contained interfering virus particles (I particles). The formation of infectious progeny virus as well as of infectious centres appeared to be reduced by the action of I particles. In the examined virus stock I particles exceeded infectious particles by at least a factor of 5 to 10. More than 50% of cells which could be demonstrated to be hit by I particles survived and formed colonies.


Structural polypeptides of mumps virus.

The structural polypeptides of egg grown mumps virus were analysed by SDS-polyacrylamide-slab-gel electrophoresis. Mumps virions contained eight major polypeptides with mol. wt. of 75, 73, 71, 61, 47, 44, 42 and 40 X 10(3). The 75 K and 61 K polypeptides were glycosylated. In virions treated with pronase and trypsin, the 75 K glycoprotein was removed more readily from the virus than the 61 K glycoprotein. The gradual removal of the 75 K glycoprotein was paralleled by a decrease of haemagglutinating activity. The large glycoprotein was cleaved into a 40 K glycoprotein by trypsin treatment. Pronase and trypsin treatment also removed the smallest 40 K non-glycosylated polypeptide. Thus this polypeptide appears to be located on the outside of the virion and probably represents a cleavage product of the large glycoprotein. Treatment of virions with 2% Triton-X 100 under alkaline conditions in the absence or presence of 2 M-KCl solubilized the two glycoproteins and a fraction of the 71 and 44 K polypeptides, but not the 73 and 47 K polypeptides. The two smallest polypeptides were solubilized by treatment with 2% Triton X-100 in the presence of 2 M-KCl. Since the 40 K polypeptide was interpreted to represent a cleavage product of the large surface glycoprotein the 42 K polypeptide was proposed to represent the membrane protein of mumps virus. The 44 K polypeptide co-migrated with Vero cell actin. The nature of the 47 K polypeptide could not be determined, but it is probably located in the central part of the virus. The 73 K polypeptide and in some experiments also the 71 K polypeptide were found in purified nucleocapsid preparations. It is concluded that mumps virus has a general polypeptide composition similar to other paramyxoviruses. However, the molecular weights of the different polypeptides of mumps virus differ markedly from the corresponding polypeptides in Newcastle disease virus and Sendai virus.


Structural modification of polyfunctional rubratoxin B: effects on mammalian adenosine triphosphatase.

Rubratoxin B, an alpha, beta unsaturated lactone containing bisanhydride metabolite of certain toxigenic strains of penicillium molds, significantly inhibited in vitro brain microsomal Na+ - K+ adenosine triphosphatase from swine, mouse, and rat with IC50's of 6.76, 6.67, and 6.80 x 10(-6) M, respectively. Mitochondrial Mg++ oligomycin-sensitive ATPase from mouse liver was also inhibited with an IC50 of 6.30 x 10(-6) M rubratoxin B. Structural modification of the polyfunctional parent compound (rubratoxin B) to rubratoxin A (a gamma lactol replaces one of the anhydride moieties) or formation of the dihydro analogs of rubratoxins A and B (2,3 saturated delta lactone) decreased inhibition to all ATPase systems. The structure-activity relationship relative to ATPase inhibition was rubratoxin B greater than dihydrorubratoxin B greater than rubratoxin A greater than dihydrorubratoxin A. The order of reactivity by these analogs to brain microsomal Na+ -K+ ATPase from 3 mammalian species and to mouse hepatic mitochondrial Mg++ ATPase was similar, indicating no significant species variations. These results suggest that the previously demonstrated in vivo inhibition of adenosine triphosphatase preparations by rubratoxin B was the result of the intact parent compound, because chemical alteration of any one of the functional moieties (either the maleic anhydride ring or conjugated lactone) resulted in significantly decreased inhibition of ATPase activity.


Effect of ammonium salts on the interferon-induced antiviral state in mouse L cells.

The addition of ammonium salts to cells treated with interferon prevents the development of the antiviral state and destroys it when already established. This treatment does not seem to act on the binding of interferon to the cells but blocks a further step of activation on the cell membrane. The anti-interferon effect of ammonium salts is reversible with a complete recovery of the antiviral state. It is postulated that these salts may stabilize the interferon-receptor complex and thus prevent the changes in configuration necessary for the establishment and maintenance of its biological functions.


Neutralization of Mason-Pfizer virus by sera from patients treated for renal disease.

Sera from 67 patients treated for renal diseases were assayed by as many as three different tests for activities against Mason-Pfizer virus (M-P V) antigens. Firstly, in patients studied before kidney transplantation, neutralizing activity against syncytium-forming units of M-P V was found in 50% of 24 cases of chronic glomerulonephritis but in only 10% of 20 cases with other diseases (P less than 0.01). These proportions were higher after treatments accompanying transplantation since, of the 19 patients without antibodies before graft, 53% showed a sero-conversion after this treatment. The incidence of M-P V antibodies did not correlate with the number of transfusions received by the patients. Neither did these antibodies correlate with the presence of antibodies to antigens associated with baboon endogenous virus or simian sarcoma virus; antibodies to the latter two viruses were found in 6 to 21% of the sera, with no specific distribution among the sera. Secondly, pseudotypes of vesicular stomatitis virus with M-P V antigens in their envelope were prepared; they were inactivated by 90% of the sera which neutralized M-P V syncytium forming units and by none of the negative sera. Thirdly, specific complement-dependent cytotoxic antibodies to HeLa cells producing M-P V were also found in 61% of the sera with neutralizing activity to M-P V and only in 12% of the sera which did not neutralize M-P V. Absorption experiments indicated that the serum activities against M-P V associated antigens were not due to anticellular antibodies directed against normal constituents of human cells. However, no evidence has been provided that the M-P V associated antigens reacting with the human sera were virus coded.


Circular, circular-linear and branched herpes simplex virus DNA molecules from arginine deprived cells.

Analysis of the virus DNA isolated from arginine deprived cells revealed that the majority of DNA molecules are linear, with some molecules having one or more short branches. In addition, circular and circular-linear DNA molecules of genome size and smaller were observed.


Replication of animal viruses in differentiating muscle cells: vaccinia and herpes simplex virus type 1.

Cells cultured from the breast muscles of 11 to 12-day-old chick embryos were infected in the undifferentiated mitotic myoblast stage or in the terminally differentiated non-mitotic myotube stage with one of two DNA viruses, vaccinia and herpes simplex virus type 1 (HSV-1). DNA synthesis was measured and production ov virus-specific DNA detected in cells infected as myoblasts or myotubes by isotope labelling, autoradiographic and buoyant density centrifugation techniques. Furthermore, fully fused myotubes resemble myoblasts in their ability to support productive infection by these DNA viruses although DNA replication and nuclear division have ceased in myotubes and only minimum levels of host-cell DNA polymerase activity are present.


Protease activation of Sendai virus infectivity; studies in non-permissive and permissive cells.

Non-infectious virus particles are produced by BSC-1 cells after infection with Sendai virus. Trypsin treatment of these particles activates their infectivity. The studies reported here show that such non-infectious virus particles adsorb normally to cells but cannot initiate infection even after very long adsorption periods. Secondary Rhesus monkey kidney cells support the growth of Sendai virus but cannot activate the infectivity of virus grown in BSC-1 cells. The significance of these results is discussed.


Decreased production of transforming virus and altered antigenic behaviour in cultured avian sarcoma cells.

Tumours induced in chickens by inoculation of avian sarcoma viruses are frequently capable of undergoing spontaneous regression. It is only those tumour cells which have been derived from progressively growing neoplasms that are able to produce transforming progeny virus in vitro and to shed into the culture medium antigens which are specifically reactive with the peripheral lymphocytes of sarcoma-bearing hosts. Following multiple passages and extended growth in culture, however, the ability of these tumour cell fluids to stimulate the lymphocytes of sensitized hosts diminishes in concert with the declining capacity of these cells to continue to synthesize fully transforming progeny virus. In certain instances, however, aged tumour cells are able to synthesize particles which contain the enzyme RNA-dependent DNA polymerase yet lack detectable envelope glycoprotein.


Stimulation of ornithine decarboxylase by human cytomegalovirus.

Human cytomegalovirus (HCMV) infection of low serum-arrested confluent whole human embryo (Flow 5000) cells markedly stimulated ornithine decarboxylase (ODC) activity. Increased ODC activity was apparent by 12 h post-infection. The capacity of HCMV to stimulate ODC was: (1) dependent upon multiplicity of infection; (2) eliminated when the virus was neutralized with specific antiserum; and (3) sensitive to ultraviolet irradiation. Virus-mediated induction, in contrast to high serum induction of ODC, was not subject to inhibition by polyamines added to the growth medium. Phosphonoacetic acid (PAA) which blocks HCMV replication by inhibiting the activity of HCMV-specific DNA polymerase and which does not prevent HCMV induced stimulation of cell DNA synthesis, reversibly inhibited HCMV-induced stimulation of ODC activity by 74%. Studies with PAA indicated that HCMV-induced stimulation of ODC activity is independent of cell DNA synthesis and that the mechanism regulating virus-induced stimulation may be related to the HCMV-specific DNA polymerase.


The neutralization of transmissible gastroenteritis virus by normal heterotypic serum.

Exposure of transmissible gastroenteritis virus of pigs to unheated normal heterotypic serum resulted in a drop in infectivity, an effect which was lost after heating the serum to 56 degrees C for 30 min or by treatments inactivating complement. Analysis of virus proteins, RNA and lipids, and centrifugation studies showed little difference between inactivated and control virus, but electron microscopy of negatively stained particles after treatment with serum revealed holes in the virus envelope, characteristic of those caused by complement in the presence of antibody.


Establishment and characterization of Indian muntjak cell lines transformed with simian virus 40.

Kidney cells of an Indian muntjak were transformed with simian virus 40 (SV40). The transformation efficiency of the tertiary cultures was very high when estimated by the agar suspension culture method. The efficiency was about 0.015% when infected at an input multiplicity of 0.4 p.f.u./cell. Clonal cell lines were established from the colonies in soft agar medium. Most of the cell lines and their subclones produced a small amount of infectious SV40. The SV40 virion antigen-positive cells in a clone increased from 0.2% to about 40% by the treatment with mitomycin C. More than 70% of the cells in two cell lines were normal in G- and C-banded karyotypes, indicating that chromosomal change is not a necessary step in the process of transformation of the Indian muntjak cells with SV40.


Enhancement of infectivity of encephalomyocarditis virus RNA by amphotericin B methyl ester.

The methyl ester of amphotericin B (AmBME), a macrolide polyene antibiotic, enhanced the infectivity of encephalomyocarditis (EMC) virus RNA for L929 cells. AmBME alone (100 microgram/ml) resulted in increases in EMC virus RNA infectivity of 10- to 100-fold. Addition of DEAE dextran at concentrations (5 microgram/ml), which alone slightly suppressed EMC virus RNA infectivity, further augmented the effects of AmBME (augmentation in infectivity up to 750-fold). AmBME did not inhibit RNase, did not enhance EMC virus infectivity and increased infectivity of EMC virus RNA which was already cell-associated. The polyenes are probably acting by increasing intracellular penetration of polyribonucleotides.


Transformation of rat cells by the hybrid virus Ad2(2+) HEY.

A set of four isogenic rat cell lines transformed by Ad22+ HEY have been studied. While all of the cell lines synthesize SV40 T antigen, only one expresses adenovirus 2 T antigen: none expresses SV40 V antigen or adenovirus 2 fibre antigen. Three cell lines contain 1 to 2 virus equivalents of SV40 and adenoviral sequences per diploid quantity of rate cell DNA and the fourth line contains five copies of SV40 and 20 copies of the adenovirus genome. At least three of the cell lines contain DNA sequences from the helper adenovirus 2 in addition to sequences from the Ad2+ HEY genome. The patterns of integrated virus sequences are complex suggesting multiple insertions of both adenovirus and SV40 DNA sequences. SV40 can be rescued from three cell lines by fusion with permissive cells.


Mechanisms of interferon induced transfer of viral resistance between animal cells.

The sequence of events initiated by interferon and leading to the antiviral state were studied as possible sites for the cell-to-cell transfer of interferon induced viral resistance. The possible role of interferon produced by recipient cells was negated by the demonstration of transfer of resistance in the presence of anti-human interferon antibody and under conditions of a single cycle of VSV growth. Transfer of sensitivity of WISH cells to mouse interferon, possibly through transfer of a membrane receptor, seems unlikely since resistance was transferred in the absence of mouse interferon. From kinetic data and the fact that actinomycin D blocked resistance in human cells for 3 h longer than in mouse cells, it seems unlikely that the mouse antiviral protein itself or its mRNA alone is a likely candidate for the transfer of resistance. Thus, by a process of elimination, we suggest that secondary messenger molecules which transmit the interferon signal from the membrane to the nucleus are the effector substance(s) for the transfer process.


Variant lines of mouse kidney cells transformed by an SV40tsA mutant with growth properties of wild-type transformed cells at nonpermissive temperature.

MKSA207 cells, a BALB/c mouse kidney line transformed by a tsA mutant of SV40, are temperature-dependent for the expression of the 'standard transformed phenotype'. At the permissive temperature (33.5 degrees C), the mKSA207 cells resembled wild-type (wt) SV40 transformants; they contained the intranuclear SV40 T antigen, grew to high saturation density in monolayer culture in either 10% or 0.5% serum, and also in methylcellulose suspension culture and became multinucleate in cytochalasin B. At the nonpermissive temperature (39.8 degrees C), the mKSA207 cells lost some of their transformed properties; they grew only to low density in 10% serum, hardly grew at all in 0.5% serum or in methylcellulose suspension culture, and remained mono- or binucleate in cytochalasin B. At 40 degrees C in low serum, mKSA207 cells lost the intranuclear T antigen and when fed 10% serum at 39.8 degrees C, accumulated large amounts of T antigen in the cytoplasm. Derivatives of mKSA207 have been selected at 39.8 degrees C in liquid medium and methylcellulose suspension culture. The heat adapted lines, like wt SV40 transformants, exhibited the standard transformed phenotype at both 33.5 and 39.8 degrees C. It is unlikely that acquisition of temperature-independence for the transformed phenotype was due to reversion of the tsA gene to wild-type because the heat-adapted cell lines displayed the cytoplasmic T antigen at 39.8 degrees C, characteristic of the parental mKSA207 cells and SV40 rescued from one of the heat-adapted lines was temperature sensitive for growth. The T antigen levels (complement fixation units per 10(6) cells) of heat-adapted lines grown at 39.8 degrees C were comparable to those of mKSA207 cells grown at 33.5 or 39.8 degrees C.


Type C virus induced by iododeoxyuridine in the human embryonic cell strain HEL-12.

The induction of a type C virus from a strain of human embryonic lung cells (HEL-12) by iododeoxyuridine (IdUrd) was examined at various times during in vitro propagation. IdUrd did not elicit type C virus production immediately following initiation of cultures from frozen primary HEL-12 cells. After overnight treatment with 30 microgram/ml IdUrd the cells expressed viral antigens and produced a type  C virus between the 25th and 80th day of in vitro growth. Production of the induced type C virus was transient. Single-cell clones of the parental HEL-12 strain were likewise susceptible to type C virus production by IdUrd. The ability of IdUrd to induce virus terminated with the onset of spontaneous type C virus production from HEL-12 cells at between 80 and 120 days of in vitro growth.


Differentiation between SV40 large-T and U antigenic sites.

Radioimmune precipitation, SDS-polyacrylamide slab gel electrophoresis and fluorography were used to investigate the SV40 large-T and U antigenic sites on species of proteins synthesized during wild type and tsA58 mutant infections in TC7 monkey cells. Wild type infection at 33 and 41.5 degrees C and the A58 infection at 33 degrees C produced similar profiles of three species ranging in mol. wt. from 84000 to 94000, all of which had both the large-T and U antigenic sites. The A58 infection at 41.5 degrees C, however, produced an additional four discrete species ranging in mol. wt. from 60000 to 74000 that contained the large-T site(s), but not the U site(s). A subpopulation of the 74000 mol. wt. species contained both sites. Therefore, the region of the A58 mutant 94000 mol. wt. species containing the U antigenic site(s), the COOH-terminal region, appears to be more sensitive to processing, probably proteolytic cleavage, than does the region containing the large-T antigenic site(s).


SV40-transformed human diploid cells that remain transformed throughout their limited lifespan.

Of ninety-one subcultured foci of SV40-transformed WI-38 human diploid fibroblasts, none yielded cells that grew indefinitely, but all cells in each subculture continued to produce T antigen and to look morphologically transformed throughout their lifespan. These results are consistent with the commitment theory of fibroblast senescence, but predict that a special transformation event is necessary to accout for the rare survivors.


Inhibition of a complete replication cycle of human cytomegalovirus in actinomycin pre-treated cells.

The study of human cytomegalovirus (HCMV) in cultures of human embryo lung fibroblasts, pre-treated with actinomycin D, has shown that under these conditions the virus infection does not proceed beyond the 'early' events of the virus replication cycle. In the same experimental conditions the growth of poliovirus type I, vaccinia virus and herpes simplex type I virus, was completely unaffected. These results suggest that the complete HCMV replication cycle requires some cellular function(s) between early transcription of the input virus genome and virus DNA synthesis.


Studies on polyoma virus DNA replication in synchronized C3H2K cells.

In G1-arrested cells infected between 1 and 12 h after having been stimulated by fresh serum to progress to S phase, polyoma virus DNA synthesis proceeded in the first half of S phase, and virus and whole cellular DNA accumulated at about the same time. However, in cells infected later than 14 h after serum stimulation, virus DNA synthesis was shifted to the next S phase. Thus, a permissive cell attains competence for polyoma virus DNA replication at a precise moment during an S phase initiated by fresh serum, which can efficiently replace the early virus host DNA stimulation function. When cells were incubated in serum that had lost its capacity to stimulate host DNA synthesis by pre-absorption with growing cells, normal yields of polyoma DNA could nevertheless be observed, which shows that extensive replication of host DNA does not seem to be an obligatory condition for virus DNA replication.


The effect of 1-beta-D-arabinofuranosylthymine on the growth of herpes simplex virus types 1 and 2.

The influence of araT on the synthesis of HSV of types 1 and 2 including a TK(--) variant, on the activity  of the dThd and the dCyd kinases and on the incorporation of radioactivity into insoluble or soluble material after infection was studied. AraT inhibited different parameters of the replication of a TK(--) variant; it is possibly phosphorylated by enzymes other than the deoxypyrimidine kinase and therefore it is less selectively phosphorylated than dThd. The mode of action of araT on herpes replication must be studied in more detail.


Mengovirus-induced capping of virus receptors on the plasma membrane of Ehrlich ascites tumour cells.

Mengovirus particles adsorbed to Ehrlich ascites tumour cells are redistributed into patches and caps without the action of antibodies. Thus capping may be an early signal in picornavirus infection.


Transcranial management of pituitary tumours with suprasellar extension.

A consecutive series of 101 pituitary tumours treated in the 10 year period 1968-78 has been examined, giant lesions being excluded. There were 48 female cases and 53 male, women predominating in the ratio of three to two in the age group 40-50 years and men showing a slight predominance in the age group 50-60 years. Most cases presented with visual deterioration which in 22 cases had been present for between one and two years, and in a further 22 for an even longer period, between two and 10 years. All patients underwent subfrontal craniotomy with mainly radical excision of the tumour followed by radiotherapy. The operative mortality was 0.99%. A system of grading of visual field defect has been described and used to compare preoperatively visual loss with postoperative visual recovery. Fifty-six per cent of cases returned to normal vision over the first two years, and a further 37% showed appreciable improvement in visual fields or acuity or both. Six per cent of cases showed no improvement in visual fields, and one patient died of postoperative deep vein thrombosis and pulmonary embolism. The degree of visual improvement has been correlated with the extent of visual defect, length of visual complaint, and size of the tumour. The importance of central and peripheral visual field analysis is emphasised yet again.


Significance of immunoglobulin deposition in peripheral nerve in neuropathies associated with paraproteinaemia.

Direct and indirect immunofluorescent studies of sural nerves were carried out in two patients with paraproteinaemia and neuropathy, in four other patients with axonal or demyelinating neuropathies, and in one normal sural nerve. IgM was demonstrated directly in the two cases of paraproteinaemia and neuropathy, and indirectly, using the serum of one of these cases, in a case of axonal neuropathy and in one case of chronic Guillain-Barré syndrome. In the latter case, IgM deposition also occurred after exposure to normal serum. These results suggest that the paraprotein itself did not directly cause neuropathy, but that immunoglobulin deposition is probably a secondary process, caused by diffusion into damaged nerves.


Electrotonic coupling among neuroendocrine cells in Aplysia.

1. We have discovered and characterized direct electrotonic synaptic coupling among a population of neuroendocrine (bag) cells in the parietovisceral ganglion of the marine gastropod Aplysia dactylomela. Pairs of ipsilateral and contralateral bag cells were impaled in vitro with microelectrodes. Current pulses applied through the electrometer amplifier to either cell influenced the other cell via electrotonic connections. 2. The coupling between bag cells was relatively weak when measured at the somata; the mean ratio of postsynaptic/presynaptic response amplitudes is 0.0075. Junctional rectification was not detected. The latency between pre- and postjunctional responses was long, up to 50 ms, a delay comparable to that for chemical synaptic transmission among neurons in this ganglion. Low-Ca2+/high-Mg2+ bathing solutions did not block transmission between bag cells, but did block chemical synaptic potentials in other identified neurons. 3. Postjunctional electrotonic responses had markedly slow time courses compared to the prejunctional responses, a characteristic that permitted summation of otherwise undetectable electrotonic PSPs and the demonstration of coupling between the two (bilateral) clusters of bag cells. 4. Based on extracellular recordings of their compound action potentials, the neurites of A. dactylomela bag cells extended a shorter distance (approximately 3 mm) along the connective than the neurites of A. californica or A. brasiliana. 5. Electrolytic lesions made along the neurites during intrasomatic coupling measurements significantly shortened the duration of postjuctional electrotonic responses, indicating that the neurites are widely electrically interconnected and, as a population, have a large effective membrane capacitance. The lesions furthermore revealed that an important site of electrotonic coupling is at the base of the pleurovisceral connective just rostral to the bag cell cluster. 6. The small-amplitude, long-latency and prolonged time course of postjunctional responses are interpreted to indicate remote and widespread coupling sites among the bag cells. This electrotonic coupling underlies the synchronized firing of the bag cells.


Interactions between bilateral clusters of neuroendocrine cells in Aplysia.

1. Activity of bilateral clusters of electrotonically coupled neuroendocrine cells (the bag cells) was studied using multiple-site intracellular and extracellular recording techniques in isolated parietovisceral ganglia of three species of Aplysia. Bilateral afterdischarges typically began with spike initiation on one side near the neurite terminals along the pleurovisceral connective; propagation of action potentials then proceeded toward the somata with potentiation to full somatic invasion in the ipsilateral bag cell cluster. This activity potentiated across the parietovisceral ganglion until contralateral spikes were initiated at a point near the bag cell somata (designated site A) and compound bag cell activity was then propagated both inward toward the somata and outward toward the circumesophageal ring of head ganglia. This sequence of events, i.e., "in one side, out the other," could occur several times during an afterdischarge, although outward propagation of activity was rarely maintained for more than 20 spikes. Synchrony between clusters was best during these periods of activity. Usually after a few episodes of this sequence, the sites of spike initiation spontaneously shifted to near the neurite terminals of each side and activity was initiated distally and propagated inward. Asychrony between clusters commonly developed when the sites for spike initiation were near the neurite terminals of each side. 2. Waveforms and temporal sequence of recorded events indicate that at least two sites for spike initiation exist within the neuritic tree of each bag cell cluster. These are the distal terminations of the neurites and a proximal site near the somata. Action potentials could be generated at this proximal site spontaneously or when electrotonically driven by contralateral activity. Removal of the bag cell somata did not interfere with bilateral behavior of the bag cell system. The proximal site is, therefore, not somatic. Activity initiated there was always more synchronous and propagated with a higher conduction velocity than activity initiated at the distal ends of the neurites. 3. Experiments were performed with and without the circumesophageal ring of head ganglia intact. Removal of the head ganglia had no effect on bilaterality of or synchrony within the bag cell system. Systematic stimulations and cuts of head ring connectives suggested that the cerebral ganglion may participate in orthodromic activation of the bag cells. 4. Our findings indicate the bag cells of Aplysia are a homogeneous population of neuroendocrine cells with multiple sites for spike initiation. Either cluster can serve as a pacemaker for the other through potentiation and electrotonic activation of the contralateral cluster at proximal sites on the neurites.


Central and peripheral control of siphon-withdrawal reflex in Aplysia californica.

1. The defensive withdrawal reflex of the siphon of Aplysia is a local response (exhibited by the organ that is stimulated) mediated by the conjoint action of both the central and peripheral nervous systems. 2. Three independent methods were used to determine the contribution of the central and peripheral nervous systems to the siphon-withdrawal reflex: 1) acute reversible deganglionation, 2) chronic deganglionation, and 3) a selective reversible hyperpolarization. With each of these techniques, the central nervous system was found to contribute about 55% of the total reflex. 3. Seven motor neurons were identified and characterized with respect to their electrophysiological properties and the motor actions. Three of the central motor cells belong to the LD clusters of cells (LDS1, LDS2, LDS3) and one is an RD cell (RDS). These four cells all receive excitatory synaptic input from siphon stimulation, excitatory synaptic input from the activity of the respiratory command cells network (interneuron II). large spontaneous IPSPs, and exhibit hyperpolarizing responses (H response) to iontophoretically applied acetylcholine (ACh). These cells all participate in the siphon-withdrawal component of a centrally commanded fixed-action pattern: spontaneous pumping movements of the mantle organs driven by the respiratory command cells. They receive an EPSP burst during the activity of the respiratory command cells and are competent to mediate the siphon motion. Three central siphon motor cells belong to the LB cluster (LBS1, LBS2, LBS3). These cells also receive excitatory input following stimulation of the siphon, a spontaneously occurring IPSP, and have H response to iontophoretically applied ACh. These cells, however, receive an IPSP burst during spontaneous pumping movement and thus do not participate in the active contraction phase of this behavior. LBS1 and LDS1 were examined with respect to their transmitter biochemistry and were found to be noncholinergic. 4. The siphon-withdrawal reflex habituates with comparable kinetics to repeated tactile stimulation when it is under central and peripheral control and when it is under peripheral control only. Thus, not only do both systems act conjointly to produce the defensive withdrawal reflex, but also they have similar response properties and are well matched to mediate the two parts of this siphon behavior.


Intracellular study of tonic-type enteric neurons in guinea pig small intestine.

1. Intracellular recording revealed a population of myenteric neurons with electrical behavior that appeared to be equivalent to the tonic-type mechanosensitive neurons found in earlier studies that utilized extracellular recording of single units. 2. Electrical stimulation of the interganglionic fiber tracts evoked a slowly rising excitatory postsynaptic potential (slow EPSP) that was prolonged for several seconds after termination of the stimulus in these cells. The slow EPSP was associated with increased input resistance and augmented excitability of the somal membrane. The somal membranes had relatively low excitability in the absence of fiber tract stimulation. This was indicated by: 1) failure of depolarizing current pulses to elicit spike discharge in some cells; 2) when spikes were elicited by depolarizing current pulses, one to three spikes occurred, and these were seen only at the onset of the pulse; 3) passive invasion of the soma by current from spikes in the cell's processes did not trigger spikes; 4) the spikes were followed by prolonged hyperpolarizing afterpotentials associated with decreased input resistance. 3. Characteristics of the augmented excitability during the slow EPSP were: 1) endogenous discharge of trains of spikes, 2) spike discharge throughout 200 ms duration depolarizing current pulses, 3) electrotonic spike potentials from the processes triggered somal spikes, 4) postspike afterhyperpolarization was reduced or abolished. 4. The slow EPSP was reduced or abolished in Krebs solution with 16 mM Mg+2 and in HEPES-buffered Krebs with 1 mM Mn2+. It was enhanced in Krebs solution with 3 times normal Ca2+. Spike discharge in elevated Ca2+ eliminated the increase in input resistance associated with the slow EPSP. 5. Calcium availability was an important factor in regulation of membrane conductance and excitability in the perikaryon. The slow EPSP provides a mechanism whereby the soma of a multipolar neuron gates the spread of excitation between its dendrites and axon.


Serotonergic activation of tonic-type enteric neurons in guinea pig small bowel.

1. Electrical stimulation of interganglionic fiber tracts of Auerbach's plexus released a chemical substance, which produced a slow EPSP associated with an increase in input resistance in the postsynaptic neuron. 2. This effect of fiber tract stimulation was mimicked by microiontophoretic application of serotonin (5-HT) to the neurons. Both the endogenous transmitter substance and exogenous 5-HT produced membrane depolarization, both increased the input resistance of the neuron, both reduced or abolished hyperpolarizing afterpotentials of the action potentials, and both augmented membrane excitability. 3. During tachyphylaxis to excess 5-HT (1 micron) in the perfusion solution, the response to fiber tract stimulation was also reversibly blocked. 4. Methysergide (30 micron) blocked both the response to fiber tract stimulation and to exogenous 5-HT. 5. Cholinergic agonists and antagonists did not alter the slow EPSP and the response to exogenous 5-HT. 6. The evidence suggests that 5-HT is the neurotransmitter substance that produces the slow EPSP in myenteric neurons.


Macrophages in experimental and human brain tumors. Part 1: Studies of the macrophage content of experimental rat brain tumors of varying immunogenicity.

Although the presence of lymphoreticular cells within tumors has been recognized for over 100 years, it is only within the last decade that the concept has arisen that standard histological examination techniques may lead to an underestimation of the true extent of tumor infiltration by lymphoreticular cells, and particularly by macrophages. The macrophage content of certain systemic tumors has been correlated with their immunogenicity and growth characteristics. Since the central nervous system is to some extent an "immunologically privileged site" and contains within it specialized reticuloendothelial cells called microglia, the authors determined the macrophage content of three rodent brain-tumor cell lines, and attempted to correlate this macrophage content with their immunogenicity and growth characteristics. Their findings indicate a direct correlation between the immunogenicity and macrophage content of these three neural tumor cell lines.


The psychiatric clinical specialist in the general hospital.

The author describes her experience as a psychiatric clinical nurse specialist functioning independently in a general hospital in a variety of roles. Seven areas of involvement illustrate the wide range of patient, staff, and other needs which this nurse specialist can meet. The author wishes to thank Joanne Damon, R.N., Sandra Zion, R.N., Dorothy Markay, R.N., and Rachel Rotkovitch, R.N., for their advice, encouragement, and support, and Florence Williams, R.N., who provided clinical supervision.


Factors affecting the rate of incorporation of a false transmitter into mammalian motor nerve terminals.

1. The incorporation of acetylmonoethylcholine (AMECh) into transmitter store at the mammalian neuromuscular junction has been studied using electrophysiological techniques. 2. Incubation of rat muscle in the presence of 0.1 mM-monoethylcholine (MECh) and 40 mM-K+ for 60-90 min produced a maximal reduction in the time constant of decay of synaptic currents and potentials, indicating that acetylcholine (ACh) had been replaced by AMECh in the released quanta. 3. Under resting conditions, muscles incubated for up to 24 hr in the presence of MECh showed no incorporation of AMECh into the released transmitter. In contrast, muscles pre-loaded with AMECh and then incubated in choline-containing medium showed a substantial reversion to ACh in the released transmitter within 4 hr. 4. It is suggested that this difference results from the rate of synthesis or packaging of transmitter being considerably slower with MECh than with choline, so that stimulation in the presence of MECh causes an over-all depletion of transmitter stores that does not occur with choline as the precursor. Measurements of m.e.p.c. amplitude following K+-evoked release in the presence of MECh or choline confirmed this interpretation. 5. In order to test whether newly formed AMECh is incorporated into a single homogeneous pool of transmitter from which the released quanta are derived, the rate of incorporation of AMECh into the released transmitter was measured as a function of the number of quanta released when transmitter output was increased by various methods. 6. The number of quanta released before 63% conversion of the released transmitter to AMECh was brought about varied from 1.3 X 10(5) (nerve stimulation at 3 Hz) to about 4 X 10(5) (release by high-K+ solution). With nerve stimulation in Mg2+-blocked muscles the value was 2.5 X 10(5). 7. Incorporation of AMECh into the quanta released by nerve stimulation appeared to take place more rapidly than its incorporation into spontaneously released quanta. 8. These results are discussed in terms of the compartmentation of transmitter stores in the nerve terminals.


Transmitter release from normal and degenerating locust motor nerve terminals.

1. An analysis has been made of spontaneous and evoked transmitter release from terminals of 'fast' excitatory motor axons on locust muscle fibres using intra- and extracellular recording together with a Ca-electrode technique for activating transmitter release from single nerve terminals on multiterminally innervated muscle fibres. 2. Spontaneous intracellular miniature excitatory junction potentials (m.e.j.p.s), recorded at active spots on these muscle fibres, occurred non-randomly with frequent bursts of m.e.j.p.s. 3. M.e.j.p.s of subnormal amplitude were also seen but contributed only a small fraction of the minature discharge. 4. The amplitude distribution of intracellularly recorded excitatory junction potentials (e.j.p.s) evoked during ionophoretic application of Ca onto single nerve terminals was adequately predicted by Poisson statistics. 5. During the course of nerve terminal degeneration m.e.j.p.s of subnormal amplitude became more frequent and eventually formed the major part of the miniature discharge. Transmitter quanta responsible for 'small' m.e.j.p.s did not contribute to evoked release either at normal or degenerating terminals. Evoked transmitter release from degenerating axon terminals before excitation-secretion coupling failure conformed to Poisson statistics. 6. It is concluded that more than one release mechanism operates on the transmitter pool or pools in locust motor nerve terminals.


Graded synaptic transmission between local interneurones and motor neurones in the metathoracic ganglion of the locust.

1. In the metathoracic ganglion of the locust some neurones can effect changes in the membrane potential of identified post-synaptic motor neurones without themselves spiking. 2. These 'non-spiking' neurones have processes only within the metathoracic ganglion, and therefore are local intraganglionic interneurones. 3. The absence of spikes in the interneurones reflects their normal physiological state and is not due to the experimental conditions. 4. When the interneurones are depolarized by the injection of current pulses lasting several hundred milliseconds, post-synaptic motor neurones are either depolarized, or hyperpolarized, for the duration of the pulse. 5. The magnitude of the change in post-synaptic voltage is graded according to the amount of presynaptic current. 6. A number of physiological tests indicate that the graded effects upon motor neurones are mediated by chemical synaptic transmission. For example, an evoked hyperpolarization of a motor neurone can be reversed in polarity by simultaneously hyperpolarizing the motor neurone with injected current. 7. At their resting potential some interneurones tonically release sufficient transmitter to have a measurable post-synaptic effect. The injection of depolarizing and hyperpolarizing currents into these interneurones effects opposite changes in post-synaptic potential. 8. Other interneurones must be depolarized from resting potential before a post-synaptic effect is observed, and hyperpolarizing currents have no post-synaptic effect. In these interneurones it is estimated that a depolarization of only 2 mV is sufficient to effect the release of transmitter. 9. The membrane potentials of non-spiking interneurones can fluctuate by as much as 15 mV during active movements of the hind legs and individual p.s.p.s as large as 5 mV can be recorded. Therefore, summed p.s.p.s or even single ones are expected to be the electrophysiological signals effecting transmitter release from these interneurones.