| homology and relationship between the genomes of papovaviruses, bk virus and simian virus 40. | a number of hybridization techniques have been used to assess the homology between the genomes of bk virus (bkv) and simian virus 40 (sv40). a noncontiguous set of homologous sequences has been localized primarily within the late region of the sv40 genome, and these sequences presumably account for the cross-reaction between v-antigens of the two viruses. the reason for the relatively strong crossreaction between sv40 and bkv t-antigens is still unclear. the sequence homology and similarity in g ... | 1975 | 170606 |
| [ultrastructure of human hepatocytes in early prenatal ontogenesis]. | the structure of hepatic cells was studied in 40 human embryos and fetuses from 4 to 16 weeks of intrauterine development. depending on the differentiation degree of organells and their amount in the hepatic cell of the embryo and fetus three types of hepatic cells are distinguished: slightly differentiated, transitional and differentiated cells. in the course of early prenatal ontogenesis the amount of slightly differentiated hepatic cells diminishes and the amount of transitional and different ... | 1975 | 170891 |
| on the mechanism of action of cholera toxin on isolated rat adrenocortical cells. comparison with the effects of adrenocorticotropin on steroidogenesis and cyclic amp output. | the effects of cholera toxin on isolated rat adrenocortical cells have been investigated. both steroid and cyclic amp output from adrenal cells were increased by the toxin in a dose dependent fashion. the concentration of toxin for half maximal stimulation for both of these responses was about 40 ng/ml. maximal steroidogenesis and cyclic amp output was obtained with similar concentrations of the toxin. a correlation was observed between the low amounts of cyclic amp produced in response to all d ... | 1975 | 170975 |
| choleragen stimulates steroidogenesis and adenylate cyclase in cells lacking functional hormone receptors. | choleragen stimulates steroid secretion and adenylate cyclase in three cell lines, adrenal tumor line (y-1), a corticotropin-resistant mutant derived from y-1 called os-3, and a receptor-deficient leydig tumor line (i-10). sensitivity for half-maximal stimulation varies from 3 to 36 pm choleragen, the i-10 line being the most sensitive. latency before the onset of steroidogenesis is longer in os-3 and i-10 cells than in the y-1 line. in both os-3 and i-10 cells choleragen stimulates adenylate cy ... | 1975 | 172154 |
| endotoxic lipopolysaccharides stimulate steroidogenesis and adenylate cyclase in adrenal tumor cells. | lipopolysaccharides (endotoxins) from escherichia coli, serratia marcesens and salmonella typhosa stimulated steroid production in y-1 adrenal tumor cells in culture with a latent period of 3-4 h. lipid a, derived from escherichia coli lipopolysaccharide, also stimulated steroidogenesis. lipopolysaccharides and lipid a also stimulate adenylate cyclase activity and cause rounding of the cells. in contrast, lipopolysaccharides do not stimulate steroidogenesis in receptor-deficient adrenal tumor ce ... | 1975 | 172155 |
| proceedings: cyclic amp in hela cells stimulated with cholera enterotoxin and methylxanthines. | | 1975 | 172178 |
| naturally occurring autoantibodies against hidden cellular antigens. | | 1975 | 172441 |
| mechanism of activation of adenylate cyclase by vibrio cholerae enterotoxin. relations to the mode of activation by hormones. | the influence of vibrio cholerae enterotoxin (choleragen) on the response of adenylate cyclase to hormones and gtp, and on the binding of 125i-labeled glucagon to membranes, has been examined primarily in rat adipocytes, but also in guinea pig ileal mucosa and rat liver. incubation of fat cells with choleragen converts adenylate cyclase to a gtp-responsive state; (-)-isoproterenol has a similar effect when added directly to membranes. choleragen also increases by two- to fivefold the apparent af ... | 1975 | 172636 |
| sphingomyelinases in human tissues. iii. expression of niemann-pick disease in cultured skin fibroblasts. | sphingomyelinase was effectively extracted cultured fibroblasts homogenized in 1% glycine. the average specific activity was 24.6 nmol substrate hydrolyzed per hr per mg protein. cultured cells from two cases of niemann-pick disease type a and one case of type b had markedly reduced enzyme activity, whereas, in type e cells, total activity was twice normal. sphingomyelinase was resolved by isoelectric focusing into three peaks of activity (i-ii), where i and ii were the major forms. species i ha ... | 1975 | 172849 |
| mechanism of action of pituitary growth hormone. | | 1975 | 172992 |
| neuronal control of neurochemical processes in the basal ganglia. | | 1975 | 173060 |
| pathways of lipoprotein metabolism: integration of structure, function and metabolism. | | 1975 | 173155 |
| prostaglandin e in cholera toxin-induced intestinal secretion. lack of an intermediary role. | prostaglandin e1 (pge1) and cholera enterotoxin stimulate small-intestine mucosal adenylate cyclase and intestinal secretion of water and electrolytes. the previous suggestion that pge may mediate cholera-toxin effects was explored in these studies. closed rabbit jejunal loops were injected in vivo with cholera toxin and compared to similar loops in the same animal injected with buffer. loop mucosal homogenates and intestinal secretions were analyzed by radioimmunoassay for camp and pge concentr ... | 1975 | 173182 |
| an investigation of the involvement of adenosine 3':5'-cyclic monophosphate in steroidogenesis by using isolated adrenal cell column perfusion. | the involvement of cyclic amp in corticosteroidogenesis was investigated by using isolated adrenal cell column perfusion. steroids were produced in response to 0.5, 1.0 and 5.0 mg of cyclic amp/ml. analysis of the shape of the response curves indicated an inverse relationship between rate of onset of steroid production and dose. a further increase in steroid production during the washout period after the 5 mg/ml dose was considered to indicate an intracellular inhibitory effect of cyclic amp. re ... | 1975 | 173285 |
| the photogeneration of superoxide by isolated photoreaction center from rhodospirillum rubrum. | | 1975 | 173311 |
| antibody-dependent lymphocyte mediated cytotoxicity mechanism and modulation by cyclic nucleotides. | | 1975 | 173470 |
| variations of cyclic nucleotide monophosphate levels during spontaneous uterine contractions. | oscillations on the concentrations of cyclic nucliotides occurred during spontaneous rhythmic contractions in rat uterus. the levels of cyclic gmp and cyclic amp were highest at the beginning of the contraction respectively the relaxation. | 1975 | 173575 |
| effect of estrogen on gene expression in the chick oviduct. correlation between nuclear-bound estrogen receptor and chromatin initiation site for transcription. | the [3h]estradiol exchange assay was used to characterize the nuclear estrogen receptor from the chick oviduct. after diethylstilibestrol (des) treatment (14 days), the oviduct nuclei contained estrogen receptors that manifested high affinity (kd = 2 x 10(-9)m) and low capacity binding (4000 to 5000 sites/cell) for estradiol. des and estradiol competed significantly for [3h]estradiol binding, while testosterone and progesterone were ineffective. these binding sites were found in the oviduct and ... | 1976 | 173720 |
| antibody-dependent cell-mediated cytotoxicity to target cells infected with type 1 and type 2 herpes simplex virus. | the phenomenon of antibody-dependent cell-mediated cytoxicity (adcc) has been extended to include target cells acutely infected with herpes simplex type 1 virus (hsv-1) or herpes simplex type 2 virus (hsv-2) in an in vitro system that employs immune human serum and human blood mononuclear cells. the cytotoxic reaction was detectable after 1 hr of incubation and was complete between 4 and 8 hr. the amount of adcc noted was directly proportional to the logarithm(10) of the effector: target cell ra ... | 1976 | 173757 |
| effects of chronic uremia, hemodialysis, and renal transplantation on plasma lipids and lipoproteins in man. | since quantitative and qualitative alterations in plasma lipoproteins may provide insights into mechanism(s) of altered lipid transport in renal failure, whole plasma triglyceride (tg) and cholesterol (chol) concentrations and lipoprotein neutral lipids and composition were examined in patients with chronic renal failure (undialyzed and dialyzed) and following successful renal transplantation. both uremic groups demonstrated increased tg (p less than 0.001) and normal chol in whole plasma and in ... | 1976 | 173766 |
| activation of renal erythropoietic factor by phosphorylation. | renal erythropoietic factor (ref) serves as a substrate for a cyclic nucleotide-dependent protein kinase. the phosphorylation of ref is associated with increased erythropoietic activity. conversely, ref isolated from hypoxic rats is a poor phosphate acceptor. these findings and the presence of a positive correlation between erythropoietin levels and urinary excretion of adenosine 3',5' monophosphate (cyclic-amp) in anemic individuals suggest that the cyclic-amp-protein kinase system plays an imp ... | 1976 | 173768 |
| cytoplasmic oestrogen receptor complex of female ovine pituitary: changes associated with the reproductive state and oestradiol treatment. | binding of oestrone and oestradiol to a pituitary cytosol receptor was studied in ovariectomized sheep during the breeding season, during anoestrus and after oestradiol treatment during anoestrus. all sheep were ovariectomized 2 weeks before removal of the anterior pituitary. oestrogen treatment consisted of the subcutaneous implantation of silastic capsules containing oestradiol-17beta 3 weeks before ovariectomy. association constants (ka) for oestrone and oestradiol and the concentration of bi ... | 1975 | 173786 |
| high content of glutamate and of atp in astrocytes cultured from rat brain hemispheres: effect of serum withdrawal and of cyclic amp. | | 1975 | 173804 |
| transformation of hamster kidney cells by bk papovavirus dna. | supercoiled bk papovavirus dna was shown to transform hamster kidney cells using the calcium phosphate co-precipitation technique. the transformed cells contained intranuclear t-antigen(s) and rescuable virus and produced progressively growing tumors when inoculated into hamsters. a novel finding was the production in tumor-bearing animals of antinuclear antibody, which reacted against normal, untransformed cells; in addition, tumor serum contained antibody against virus-specific t-antigen(s). | 1975 | 173887 |
| [clinical aspects of intrauterine infections (author's transl)]. | examples of typical embryopathy (rubella, cytomegaly) and fetopathy (toxoplasmosis, listeriosis) demonstrate the disastrous effects intrauterine infections may have on the fetus. even if they play a relatively small role numerically, they deserve our particular attention because we feel and hope that, by extending maternity care to environmental hygiene and prophylactic vaccination, they can be partly prevented and, by improving prenatal serological diagnosis and intensifying the cooperation of ... | 1975 | 173989 |
| a study of the immuno-suppressive activity of herpes simplex virus type 2 and the tumor enhancing potential of the virus on yoshida sarcoma. | the relative delays of yoshida sarcoma (ys) tumor induction were used as indicator for the immunosuppressive potential caused by the subcutaneous infection of sprague-dawley rats with approximately 10(7) tcd50 hsv-2. the tumor formation is clearly accelerated and the number of tumors is increased as compared to sham injected rats. the impairment of immunity is at its maximum when the virus and the ys cells are applied simultaneously, whereas virus given after the tumor is of no consequence. the ... | 1975 | 174048 |
| apoprotein stability and lipid-protein interactions in human plasma high density lipoproteins. | temperature-dependent conformational changes of the principal apoprotein of human plasma high density lipoprotein (hdl), apoa-i, have been studied in the isolated apoprotein, in complexes of apoprotein with phospholipid, and in intact hdl. differential scanning calorimetry shows that in solution apoa-i undergoes a reversible, two-state thermal denaturation (midpoint temperature 54 degrees). the enthalpy (2.4 cal/g)(10.0 j/g) and specific heat change (0.08 cal/degrees c per g)(0.33 j/degrees c pe ... | 1975 | 174082 |
| an avian-related new herpesvirus infection in man--subacute myelo-optico-neuropathy (smon). | | 1975 | 174155 |
| [etiologic role of cytomegalovirus in infectious mononucleosis and certain viral diseases]. | | 1975 | 174231 |
| interaction of ultrasound with neoplastic tissue. ii. systemic effects after local sonic irradiation. | local sonic irradiation was applied to subcutaneously implanted furth-columbia rat wilms' tumor. the weight and the rate of tritiated thymidine uptake were measured in host organs distal to the application field. kidney and spleen weights were inhibited by the wilms' tumor, and sonication of the tumor removed all or part of this inhibition. liver weight was increased after sonication of tumor-bearing rats but not in nontumor-bearing rats. this may have been a response to tumor-specific substance ... | 1976 | 174264 |
| association of herpes simplex virus type 1 dna with host chromosomal dna during productive infection. | | 1976 | 174293 |
| metabolism of thymine in tumor tissue: the origins of beta-aminoisobutyric acid. | | 1975 | 174403 |
| rheumatology rounds at the hospital for special surgery. aspects of systemic lupus erythematosus: consideration of viral and genetic factors, and remarks on therapy. | the presentation of sle in one member of a twin pair has provided the background for discussion of genetic and environmental variables involved in the pathogenesis of the syndrome. there are promising leads (developing in parallel with studies in man and in nzb mice) suggesting that sle results from the interaction of genetic factors with an etiologic stimulus provided by type-c rna viruses. the principles of management of sle have been reviewed briefly. | 1975 | 174427 |
| galactose metabolism in relation to cataract formation in marsupials. | erythrocytic galactokinase and/or galactose-1-phosphate uridyl transferase activity were low in many species of marsupials. however, cataract formation was observed only in pouch-young members of these species when reared on cow's milk. the galactose tolerance of young kangaroos was found to be greatly impaired, but improved rapidly and markedly at the stage of which the definitive structure of the ruminant type of stomach as in adults is formed. the combination of high absorption of galactose a ... | 1975 | 174538 |
| murine leukaemia virus expression in the akr following thymectomy. | thymectomy effectively prevents the development of spontaneous lymphoma in the akr but how this effect is achieved remains to be determined. one possible mechanism, namely suppression of genomic expression of the oncogenic murine leukaemia virus now seems unlikely since levels of the group specific mulv antigen were in comparision with their sham operated controls unaltered in both neonatally and adult thymectomized akr. | 1975 | 174705 |
| increased cyclic adenosine 3',5'-monophosphate content in guinea pig ileum after exposure to staphylococcus aureus delta-toxin. | to compare staphylococcus aureus delta-toxin with cholera toxin, which is known to increase cellular cyclic adenosine 3',5'-monophosphate (camp), studies were undertaken to determine the effect of delta-toxin on the camp content of guinea pig ileum maintained in vitro. concentrations of delta-toxin as low as 0.40 mug/ml increased camp levels in guinea pig ileum after 2 h of incubation. histological damage was seen in ileum exposed for 2 h to delta-toxin concentrations of 100 mug/ml. as little as ... | 1976 | 175015 |
| immunological properties of bovine serum lipoproteins and chemical analysis of their protein moieties. | four classes of bovine serum lipoproteins were isolated by precipitation with dextran sulfate, ultracentrifugation, and preparative electrophoresis on polyacrylamide gel. very low density lipoprotein (d less than 1.019 g/ml) was related immunologically to low density lipoprotein-two (d 1.039 to 1.060 g/ml) and high density lipoprotein (d 1.060 to 1.210 g/ml) was related immunologically to low density lipoprotein-one (d 1.019 to 1.039 g/ml), but the two pairs were immunologically distinct. the ma ... | 1976 | 175102 |
| ultrastructure of mycoplasma-like organisms purified from clover phyllody-affected plants. | | 1976 | 175171 |
| translation of oncogenic virus rna in xenopus laevis oocytes. | | 1976 | 175294 |
| clinical applications of cell surface markers. | | 1975 | 175398 |
| dependence of myocardial redox systems on the concentration of exogenous substrate. | isolated rat hearts were perfused according to langendorff at a range of perfusion pressures and the variations of intracellular oxygenation were studied under these conditions by optical methods. the oxygen consumption was directly related to left ventricular performance in all cases examined, the relationship being independent of both the substrate used (glucose, beta-oh-butyrate) and its concentration (2.5, 5.0, 10.0 mm). the changes in the respiratory rate were accompanied by modifications o ... | 1975 | 175412 |
| behaviorally evoked hippocampal theta waves: a cholinergic response. | forced running in a treadmill results in the instantaneous appearance of a synchronous electroencephalographic pattern in the dorsal hippocampus of the rat. a similar bioelectric response in the absence of movement is induced by physostigmine. both responses are blocked with scopolamine. lesions of the medial septal nucleus abolish hippocampal theta waves induced by forced running or physostigmine. | 1975 | 175440 |
| [leukocytosis and polynucleosis in infectious disease]. | during bacterial infections, the intensity of the polymorphonuclear leukocytosis depends on the bacterium but also on the mechanism and extent of the infection. polymorphonuclear leukocytosis is greater during pyogenic and anaerobic infections. it is due to deep suppuration, septicemia of thrombophlebitic origin, acute endocarditis, purulent meningitis and pneumonia. the increase in the number of polymorphonuclear cells is, on the other hand, less marked in sub-acute bacterial endocarditis. apar ... | 1975 | 175454 |
| pancytopenia and "caillary leak syndrome" with infectious mononucleosis. | a 19-year-old man with documented infectious mononucleosis presented with pancytopenia and a megaloblastic bone marrow. he developed a "capillary leak syndrome" with an expanded plasma volume of 9,290 ml and normal right heart and pulmonary artery pressures. the patient had a dramatic recovery after corticosteroid therapy. | 1976 | 175508 |
| [dermatofollicular method of vaccination of chickens against newcastle disease and pox]. | | 1975 | 175550 |
| effects of cholera enterotoxin, glucagon, and dibutyryl cyclic amp on rat liver alkaline phosphatase, bile flow, and bile composition. | cholera enterotoxin, 45 mug per 250 g body weight, administered intravenously to rats, caused a 6-fold rise in the activity of liver alkaline phosphatase in 12 hr. there was no change in bile volume or in the concentration or total bile content of na+, k+, hco3-, or cl- for 36 hr after the administration of cholera toxin. however, bile phospholipid output fell markedly from a control level of 15.0 +/- 1.0 mumol per 6 hr to a low level of 4.0 +/- 1.2 mumol per 6 hr in the 12- to 18-hr collection, ... | 1976 | 176082 |
| immune host response to corneal grafts sensitized to herpes simplex virus. | experiments were performed to study the fate of corneal grafts sensitized to herpes antigens when grafted to hsv-sensitized hosts. nonsensitized grafts in systemically sensitized hosts remained clear, whereas all locally sensitized grafts in systemically sensitized hosts became opaque within ten days. the stroma showed severe lymphocytic and plasma cell infiltration and neovascularization. one-half of the corneas from systemically sensitized hosts grafted to eyes previously infected opacified in ... | 1976 | 176129 |
| activation of adenylate cyclase by cholera toxin in rat liver homogenates. | the effect of cholera toxin on adenylate cyclase from rat liver has been studied in a broken cell preparation. the activation of the enzyme in this in vitro preparation requires the addition of nicotinamide adenine dinucleotide (nad) to the incubation medium and the presence of cell components other than the membrane-bound adenylate cyclase. once the activation of the cyclase is produced, the effect persists despite repeated washing or solubilization of the enzyme. the effect can be obtained wit ... | 1976 | 176181 |
| mechanism of activation adenylate cyclase in vitro by polymyxin-released, heat-labile enterotoxin of escherichia coli. | heat-labile enterotoxic material released from escherichia coli by polymyxin b activates the adenylate cyclase of pigeon erythrocyte ghosts in a time- and concentration-dependent manner. the activation requires nicotinamide adenine dinucleotide, adenosine triphosphate, and another component of the erythrocyte supernatant. the active species has a molecular weight of about 23,000-24,000 daltons, is inhibited by antibodies to the toxin of vibrio cholerae, and is not irreversibly denatured by sodiu ... | 1976 | 176279 |
| mode of action of vibrio cholerae enterotoxin in cultured adrenal tumor cells. | the effects of vibrio cholerae enterotoxin on steroidogenesis and on formation of adenosine 3':5'-cyclic phosphate (cyclic amp) in two adrenal tumor cell lines were compared. steroidogenesis was half-maximal at concentrations of 1 ng of cholera toxin/ml in the mutant os-3 cells and 3 ng of cholera toxin/ml in the parent y-1 cells. at the end of an 8-hr incubation, toxin-induced formation of cyclic amp in the mutant cell line was reduced by 90%. a molar ratio of gm1 ganglioside (galactosyl-n-acet ... | 1976 | 176280 |
| multiple roles of erythrocyte supernatant in the activation of adenylate cyclase by vibrio cholerae toxin in vitro. | peptide a1 of vibrio cholerae toxin, nicotinamide adenine dinucleotide, adenosine triphosphate, and a soluble protein present in erythrocyte supernatant are required for the activation of pigeon erythrocyte ghost adenylate cyclase but are not required to maintain the activated state. the compounds are all required simultaneously, and when all are added to ghosts, adenylate cyclase activity increases at a linear rate without delay. under optimal conditions significant activation of cyclase is giv ... | 1976 | 176281 |
| cholera toxin and the adenylate cyclase-activating signal. | studies with chemically modified cholera toxin derivatives showed that all treatments that decreased the ability of toxin to bind to mouse thymus cells or to polystyrene-coupled gm1 ganglioside caused a concomitant reduction in the toxin's ability to increase adenosine 3':5'-cyclic phosphate (cyclic amp) in thymus cells and skin vascular permeability in rabbits. dissociation of the h (heavy) and l (light) subunits abolished the biologic activity without inhibiting receptor binding, as did treatm ... | 1976 | 176282 |
| interaction of vibrio cholerae toxin with sarcoma 180 cell membranes. | three discrete phases are discernible in the activation, by vibrio cholerae toxin, of adenylate cyclase in fragments of sarcoma 180 cell membranes. in the first, or preparatory, phase the toxin must be exposed to dithiothreitol or nicotinamide adenine dinucleotide (nad) in the absence of the membranes. in the second phase, the prepared toxin is dissociated to yield a macromolecular cyclase-activating factor (mcaf) in the presence of the membranes. in the third phase, membrane basal adenylate cyc ... | 1976 | 176283 |
| orphan airlift. enteric pathogens isolated from vietnamese children immigrating to the united states. | isolation studies for bacterial and parasitic agents were carried out on stool specimens from vietnamese infants at the time of their mass airlift to the united states. one or more bacterial pathogens were found in 49% of the 367 stool specimens cultured. the isolates included enteropathogenic escherichia coli (161), shigella (16), salmonella (15), but no salmonella typhi or vibrio cholerae. parasites identified in 88 stool specimens included giardia lamblia (10), ascaris lumbricoides (7), and e ... | 1976 | 176481 |
| inhibition of enterotoxin-induced intestinal secretion by the polypeptide antibiotic, polymyxin. | | 1976 | 176498 |
| structure and function of cholera toxin and hormone receptors. | the enterotoxin from vibrio cholerae is a protein of 100,000 mol wt which stimulates adenylate cyclase activity ubiquitously. the binding of biologically active 125i-labeled choleragen to cell membranes is of extraordinary affinity and specificity. the binding may be restricted to membrane-bound ganglioside gm1. this ganglioside can be inserted into membranes from exogenous sources, and the increased toxin binding in such cells can be reflected by an increased sensitivity to the biological effec ... | 1976 | 176537 |
| [the effect of multiple injections of acth (alone and combined with sodium ribonucleinate) on incorporation of p32-orthophosphate into the mitochondrial rna of the liver, spleen and heart of white rats]. | | 1976 | 176651 |
| [effect of cyclic amp on the proliferation and differentiation of hematopoietic cells (literature survey)]. | | 1975 | 176654 |
| positive inotropic activity of cholera enterotoxin on the embryonic chick heart. | the characteristics of the positive inotropic effect of different preparations of cholera toxin on the isolated 4-day-old embryonic chick heart were investigated. crude (cct) as well as partially purified and purified (pct)preparations of cholera toxin were shown to have positive inotropic activity. contractility was increased within 1 minute and reached a maximum at approximately 40 minutes after exposure to toxin. activities of all three toxin preparations were abolished by heating, their effe ... | 1976 | 177757 |
| functional incorporation of ganglioside into intact cells: induction of choleragen responsiveness. | nctc 2071 cells are unable to synthesize the monosialoganglioside gm1. when grown in chemically defined medium these cells contained no detectable gm1 and did not accumulate 3': 5'-cyclic amp in response to choleragen. incubation of the cells with [3h]gm1 permitted quantification of ganglioside uptake which was dependent on time and concentration of [3h]gm1 in the medium. responsiveness to choleragen was demonstrated with binding of as few as 17,000 molecules of [3h]gm1 per cell; a maximal respo ... | 1976 | 177969 |
| pregnancy interrupting effects of some bacterial toxins. | embryotoxic properties of shigella dysenteriae and clostridium perfringens toxins, of e. coli endotoxin, v. cholerase and e. coli enterotoxins were compared in mice. e. coli endotoxin has embryotoxic effects at all stages of pregnancy. e. coli enterotoxin v. cholerae enterotoxin and shigella dysenteriae toxin are most effective mainly at earlier stages of pregnancy. clostridium perfringens toxin has no embryotoxic effect. | 1976 | 178014 |
| monolayer cultures of normal adult rat adrenocortical cells: steroidogenic responses to nucleotides, bacterial toxins and antimicrotubular agents. | monolayer cultures of normal rat adrenocortical cells were treated with agents which stimulate steroidogenesis by y-1 adrenal tumour cells. choleragen was active, whereas cyclic nucleotides other than cyclic amp, bacterial endotoxins and antimicrotubular agents were inactive. | 1976 | 178525 |
| activation of intestinal mucosal adenylate cyclase by shigella dysenteriae i enterotoxin. | because the mechanism whereby shigella dysenteriae i enterotoxin induces intestinal secretion is unclear, the effect of this toxin on adenylate cyclase activity in rabbit ileal mucosa was studied under various in vitro and in vivo conditions. activation of adenylate cyclase by shigella enterotoxin was observed only when substrate (atp) concentrations above the km of adenylate cyclase were employed. these concentrations of atp are greater than those required to demonstrate activation of adenylate ... | 1976 | 178569 |
| oppositional effects of acetylcholine and isoproterenol on isometric tension and cyclic nucleotide concentrations in rabbit atria. | the effects of acetylcholine chloride and isoproterenol on myocardiial cyclic gmp, cyclic amp and on isometric tension were studied in isolated electrically driven rabbit atria. acetylcholine (0.5 mum) produced a significant decrease in isometric force that was associated with a significant elevation in atrial cyclic gmp. cyclic amp was significantly lowered at 15 seconds after the addition of acetylcholine, but was only slightly decreased at earlier time periods. both the negative inotropic act ... | 1975 | 178695 |
| [symptomatology of diseases caused by c1. perfringens]. | | 1976 | 178949 |
| [antibodies to viral antigens in rheumatoid arthritis]. | | 1976 | 179153 |
| viral diseases of cats: current concepts. | | 1976 | 179185 |
| [localization of genome rna synthesis in sendai virus]. | localization of sendai virus 50s rna in ehrlich ascitic carcinoma cells was studied. at 48 hours postinfection virus-specific 50s rna was found in the nucleus after 30 min exposure to 3h-uridine, and its amount increased after 1-hour exposure to the precursor reaching 18% of the total nucleus virus-specific rna. after 2-hour or longer exposure to the precursor the amount of 50s rna in the nuclei decreased considerably and in the cytoplasm in this gradient region a considerable radioactivity appe ... | 1975 | 179216 |
| [health aspects of the study of bdellovibrio bacteriovorus as a natural factor in the self-purification of reservoirs]. | | 1975 | 179245 |
| [the biological role of estriol]. | it was demonstrated on the uteri of women and guinea pigs that estriol (in vitro) possessed a marked affinity to the estradiol-binding system of human and guinea pig uteri; the activity of steroid-receptor interaction of estriol in vitro constituted 9.4% for guinea pigs and 17% for man in relation to the estradiol activity. administration of estriol to guinea pigs in vivo in a dose of 0.25-0.5 mg led to a sharp reduction of the estradiol-binding capacity of the receptor system of the uterus. it ... | 1975 | 179639 |
| [the diuretic action of morphine in rats]. | | 1976 | 179647 |
| [role of bioenergetic changes in the mechanism of action of nonsteroid anti-inflammatory agents]. | in experiments on rats the antiphlogistic action of sodium mephenaminate and salicylate was found to be more pronounced under conditions of ovalbumin than that of dextran inflammation. the antiphlogistic effect of sodium salicylate was greater than that of mephenaminate in ovalbumin inflammation; this correlated with a more marked drop in the content of lactic acid in the blood and with a more complete elimination of uncoupling of oxidative phosphorylation in the hepatic mitochondria than in cas ... | 1976 | 179649 |
| arginyl-trna synthetase from baker's yeast. purification and some properties. | arginyl-trna synthetase from baker's yeast (saccharomyces cerevisiae, strain 836) was obtained pure by a large-scale preparative method, which involves four chromatographic columns and one preparative polyacrylamide gel electrophoretic step. the enzyme has a high specific activity (9000 u/mg) and consists of a single polypeptide chain of molecular weight approximately 73000 as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate. amino acid analysis of the e ... | 1976 | 179818 |
| biochemical and mechanical effects of phenylephrine on the heart. | injections of phenylephrine into isolated perfused guinea pig hearts increased cyclic amp and phosphorylase a. reserpine pretreatment or propranolol decreased or abolished the phenylephrine-induced biochemical changes without affecting the contractile response. phentolamine, on the other hand, shifted the phenylephrine dose-response curve for contractility to the right without affecting the other parameters. the biochemical effects of phenylephrine are apparently due to the release of noradrenal ... | 1976 | 179825 |
| [radioreceptor assay of gonadotropin]. | | 1976 | 180307 |
| sodium-stimulated alpha-aminoisobutyric acid transport by membrane vesicles from simian virus-transformed mouse cells. | uptake of alpha-aminoisobutyric acid, by membrane vesicles derived principally from the plasma membrane and endoplasmic reticulum of mouse 3t3 cells transformed by simian virus 40, is stimulated by sodium chloride. both in the presence and absence of na+ uptake is time-dependent and osmotically sensitive. the na+-stimulated uptake is inhibited by other amino acids. the kinetics of transport of alpha-aminoisobutyric acid are shown to be biphasic both in whole cells and in the membrane vesicles. o ... | 1976 | 180527 |
| [studies on the physiopathology of cholera in bari]. | during a small epidemic of cholera in south italy in summer of 1973, the infection showed some peculiarities and differences in comparison with cholera classic picture of asiatic areas. in this paper epidemiological, pathogenetic, clinical and biochemical data of patients admitted to the institute of infectious diseases of bari are reported. the age of the majority of patients (over 50) is an important factor for understanding cause of infection; but also preexistent basal diseases are responsib ... | 1975 | 180912 |
| nitrogenase of azotobacter chroococcum. kinetics of the reduction of oxidized iron-protein by sodium dithionite. | the kinetics of the reduction of oxidized fe-protein of nitrogenase from azotobacter chroococcum by sodium dithionite were studied by stopped-flow and rapid-freezing e.p.r. (electron-paramagnetic-resonance) spectroscopy. the appearance of the gav. = 1.94 e.p.r. signal (0.24 electron integrated intensity/mol) was associated with a one-electron reduction by so2--with k greater than 10(8)m-1-s-1 at 23 degrees c. a value of k = 1.75s-1 was obtained for the rate of dissociation of s2o42- into 2so2-- ... | 1976 | 180978 |
| endonucleolytic cleavage of murine leukemia virus 35s rna by microsome-associated nuclease. | | 1976 | 180996 |
| phosphorylation of the active, a1 component of cholera toxin by protein kinase. | cholera toxin, an activator of adenylate cyclase in a wide variety of cells, is a substrate for the phosphotransferase reaction catalyzed by purified cyclic adenosine 5'-monophosphate dependent bovine cardiac muscle protein kinase and the protein associated with human erythrocyte membranes. phosphorylation occurs when the toxin is dissociated with 5-20 mm dithiothreitol and is restricted to the a1 or "adenylate cyclase activating" subunit of the toxin. | 1976 | 181050 |
| in vitro anamnestic antibody response: differential cellular and calcium requirements for induction by antigen and regulation by cyclic amp. | | 1976 | 181149 |
| characteristics of immunity induced by neuraminidase-treated lymphosarcoma cells in c3h (mtv+) and c3h (mtv-) mice. | the immunogenicity of 6c3hed lymphosarcoma ascites tumor cells was greatly enhanced upon treatment with vibrio cholerae neuraminidase. as a result, mammary tumor virus (mtv)-free c3h mice which had been repeatedly immunized with the treated cells resisted a challenge of 10(6) untreated viable cells inoculated i.p., whereas all control animals died after receiving less than 10 lymphosarcoma tumor cells. in contrast, there was no increase in the refractoriness to challenge when mtv-infected c3h mi ... | 1976 | 181351 |
| interferon action: role of membrane gangliosides. | | 1976 | 181911 |
| trophoblastic pseudotumor of the uterus: an exaggerated form of "syncytial endometritis" simulating a malignant tumor. | twelve cases of a hitherto unrecognized pseudotumorous trophoblastic invasion of the myometrium are analyzed. human chorionic gonadotropin (hcg) was identified by an immunoenzyme technique in the cytoplasm of the invasive cells. the lesion may be localized and only superficially invasive or deeply invasive and have a gross appearance suggesting a neoplasm in the excised uterus. in either case, this process has been confused with various types of malignant tumors, most often choriocarcinoma, from ... | 1976 | 182351 |
| the effects of cholera toxin on the adrenal weight in hypophysectomized rats. | the effects of cholera on adrenal weight in hypophysectomized rats were investigated, in an attempt to demonstrate an acth-like, adrenal trophic effect of the toxin. the results suggested that the toxin probably exerts is acth-like action on the adrenal via adenylate cyclase. cholera toxin was also shown to have a thermolytic action, similar to that of acth, probably due to stimulation of adrenal glucocorticoid secretion. | 1976 | 182572 |
| similarity of responses of cultured sertoli cells to cholera toxin and fsh. | the effects of cholera toxin on the responses of cultured sertoli cells were compared with those elicited by follicle-stimulating hormone (fsh), and n6o2'-dibutyryl-3',5'-cyclic amp (bu2camp). addition of fsh or cholera toxin increased camp levels. subsequently there was greater rates of conversion of testosterone to 17beta-estradiol, formation of androgen-binding protein (abp), and incorporation of [3h]thymidine into dna by sertoli cells prepared from testes of immature rats and cultured in the ... | 1976 | 182580 |
| stimulatory and inhibitory effects of cyclic amp on pancreatic glucagon release from monolayer cultures and the controlling role of calcium. | when glucagon release from monolayer cultures of newborn rat pancreas was measured over four hours in media containing 2.5 mm ca++, a significant cyclic amp-related inhibition of release was observed. this was noted whether intracellular cyclic amp levels were raised by the addition of exogenous cyclic amp or dibutyryl cyclic amp, by phosphodiesterase inhibition with theophylline, or by the stimulation of adenylate cyclase with cholera toxin. the inhibition was concentration dependent for cyclic ... | 1976 | 182608 |
| augmented immunogenicity of tumor cell membranes produced by surface budding viruses: parameters of optimal immunization. | membranes prepared from tumor cells infected with surface budding viruses are much more immunogenic than membranes from uninfected tumor cells. factors affecting immunization with membranes from virus-infected tumor cells were studied. preparations made with influenza virus were clearly superior to those prepared with vesicular stomatitis virus (vsv). membranes infected with vsv were maximally immunogenic at a dose equivalent to a 10% cell pack whereas influenza-virus-infected membranes were imm ... | 1976 | 182646 |
| inflammatory cells in solid murine neoplasms. i. tumor disaggregation and identification of constituent inflammatory cells. | mechanical and enzymatic methods of disaggregating tumors were studied with the goals of (1) minimizing cell losses while (2) maintaining functional and surface membrane markers needed to objectively identify inflammatory cells (ic)1 in resultant suspensions. application of the principles and methods described makes accurate estimation of the percentage of each ic type present in neoplasms possible for the first time. compared to purely mechanical means of disaggregating tumors, all enzyme mixtu ... | 1976 | 182647 |
| comparison of jc and bk human papovaviruses with simian virus 40: dna homology studies. | studies were performed to ascertain the relationship of human papovavirus jc to bk virus and to simian virus 40 (sv40) by further restriction endonuclease analysis and by dna-dna competition hybridization on membrane filters. form i dna extracted from two new isolates from cases of progressive multifocal leukoencephalopathy of human papovaviruses that were jc-like in their antigenic properties were found to yield restriction endonuclease fragmentation patterns similar to those of prototypic jc v ... | 1976 | 183019 |
| redistribution of immunoglobulin receptors on human neutrophils and its relationship to the release of lysosomal enzymes;. | release of the lysosomal enzyme beta-glucuronidase from human neutrophils was induced by igg or its fc fragment, aggregated by immune precipitation or by coating on latex particles. such release was inhibited when the cells were preincubated with free igg or fc fragments; f(ab')2 fragments were ineffective in both inducing and inhibiting beta-glucuronidase release. neutrophils incubated with igg or fc fragments, when challenged with anti-igg antibody, released lysosomal enzymes without the relea ... | 1976 | 183051 |
| increase of glucagon receptors in hyperthyroidism. | | 1976 | 183145 |
| cyclic amp and growth of ehrlich ascites tumor cells. lack of cyclic amp elevation in nutritionally deprived cells and mechanism of retardation of growth by dibutryl cyclic amp. | cyclic amp levels in ehrlich ascites tumor cells changed little after deprivation of cells of essential nutrients, serum, glucose and amino acids, deprival of each of which leads to marked inhibition of growth and protein synthesis. cyclic amp levels also changed little after the addition of these nutrients to deprived cells. thus cyclic amp is not likely to be the intracellular mediator for growth regulation by these three nutrients. elevation of cyclic amp levels for short periods by exposure ... | 1976 | 183828 |
| [adenylate cyclase system of the liver]. | | 1976 | 183838 |
| cytomegalovirus hepatitis in an artificial kidney unit. | serum hepatitis is a dreaded risk in connection with regular dialysis treatment (rdt). liver damage, however, can be cuased by other diseases, such as infection with cytomegalovirus (cmv). two cases in our artificial kidney unit revealed signs of liver damage with increased liver enzyme activity. case 1, a woman, was on rdt after an unsuccessful renal transplantation, and case 2, a man, belonged to the staff. serum hepatitis was initially suspected in both cases, but repeated examinations of the ... | 1976 | 184060 |
| effect of disinfectants on variola virus in cell culture. | twenty kinds of disinfectants were examined for ability to inactivate variola virus. cytopathic effect and plaque formation on monolayer cultures of an established monkey kidney cell line were used as indicators of virus inactivation. a micromethod using microplate cultures, and not requiring a co2 incubator, was adopted. the procedures were straightforward, showing good reproducibility. among the compounds tested, several were found to be superior because of the minimum concentrations required ... | 1976 | 184735 |
| surface antigens on hela cells persistently infected with hvj (sendai virus). | surface antigens of helahvj cells, a cell line persistently infected with hvj, were studied by fluorescent antibody staining. after absorption with concentrated hvj virions and hela cells, anti-helahvj antiserum was able to demonstrate specific surface fluorescence on helahvj cells, while this serum no longer reacted with original hela cells nor with hvj virions. during cytolytic infection of hela cells with hvj, this specific surface antigen appeared at an early stage of infection prior to the ... | 1976 | 184762 |
| a cyclic adenosine 3':5'-monophosphate-mediated effect of cholera toxin on high-molecular-weight glycoprotein species of malignant cells. | a comparison of the pronase-sensitive glycosylated species detectable under permissive and nonpermissive conditions by normal rat kidney cells transformed by a temperature-sensitive derivative of rous sarcoma virus reveals relative decreased labeling of high-molecular-weight glycosylated species under conditions that allow the expression of transformation, in medium supplemented either with 0.5% calf serum or with human alpha2-macroglobulin, 100 mug/ml. exposure of the cultures to cholera toxin ... | 1976 | 184943 |
| msh stimulates adenylate cyclase and tyrosinase in cultivated melanoma cells in the presence of cytochalasin b. | | 1976 | 185075 |
| the syrian hamster: a reproducible model for studying changes in intestinal fluid secretion in response to enterotoxin challenge. | syrian hamsters respond in a predictable and reproducible manner to intragastric administration of purified cholera enterotoxin by intraluminal accumulation of fluid in the small bowel, cecum, and proximal colon. in the majority of animals this process is self limiting, and recovery occurs with full reabsorption of intestinal fluid by 30 to 35 h. the secretory response to 75 mug of cholera toxin has been defined, and the model was utilized to study the inhibitory effects of indomethacin, polymyx ... | 1976 | 185149 |