Intracellular calcium ions activate a low-conductance chloride channel in smooth-muscle cells isolated from human mesenteric artery

Calcium-activated chloride currents were studied by the patch-clamp technique in vascular smooth muscle cells (VSMC) isolated from human mesenteric arteries. Bath application of 20 mM caffeine caused the cell membrane to depolarize by a calcium-activated inward current that peaked to –654±230 pA (holding potential –50 mV). Cell-attached, at the same time inwardly directed single-channel currents were detected with an amplitude of –0.22 pA. In open-cell-attached patches channel activity was triggered by elevating [Ca²⁺]_i to 10 M. At –60 mV the mean amplitude of the current was –0.24 pA and the mean open time of the channels was 28 ms. Plotting the amplitude of the current versus the test potential yielded a single-channel conductance of 2.8±0.5 pS. The currents disappeared when [Cl^–] was reduced from 150 mM to 5 mM at the cytosolic side of the inside-out patch at a holding potential of -60 mV (calculated reversal potential –58 mV) suggesting that the calcium-activated current was a chloride current. This suggests that, in human mesenteric VSMC, elevation of [Ca²⁺]_i activates a low-conductance chloride channel, which may mediate the agonist-induced depolarization of the cell membrane.     

Temporal and geographical distributions of human rotavirus serotypes, 1983 to 1988.

Between 1983 and 1988, subgroups and serotypes were determined for 907 of 1,084 clinical specimens of rotaviruses collected in various countries of Europe, North and South America, Africa, and Asia. Enhanced enzyme immunoassays based on monoclonal antibodies specific for rotavirus proteins VP6 and VP7 were used. Significant differences in the prevalent serotypes were detected from year to year in the United Kingdom and Brazil and also in different countries during the same year. Throughout the study, rotavirus serotype 1 was detected most often (53.8%), followed in frequency by serotype 2 (17.8%), serotype 3 (12.1%), serotype 4 (11.1%), and serotypes other than 1 to 4 (5.1%). No individual serotype was found to predominate consistently in any one location. In the United Kingdom, rotavirus serotypes varied in prevalence in a regular but not predictable way. We suggest that a similar epidemiology might be found in other settings. Seventeen unusual strains were detected. Of these, five strains did not react with reference monoclonal antibodies specific for subgroup I and subgroup II, but they reacted with rotavirus group A-specific polyclonal and monoclonal antibodies; four strains were of subgroup II, serotype 2, and at least one had a "long" electropherotype; two strains were of subgroup I, serotype 2 with a long electropherotype; and one strain was of subgroup I, serotype 3. Five group C rotaviruses were detected.     

Human polymorphonuclear leukocyte interaction with cyclosporine A.

The effects of cyclosporin A (cyA) on human polymorphonuclear leukocyte function, including phagocytosis, its associated metabolic burst, bacterial killing, and chemotaxis, were evaluated. Both Pseudomonas aeruginosa and Staphylococcus aureus were used as test particles. Polymorphonuclear leukocytes incubated in 10 and 50 micrograms of cyA per ml behaved normally with respect to phagocytosis and hexose monophosphate shunt activity at both high (10:1) and low (2:1) S. aureus/leukocyte ratios. With a small bacterial inoculum, killing of S. aureus was slightly impaired at early times only in the presence of 50 micrograms of cyA per ml. Phagocytosis and killing of P. aeruginosa with both large and small bacterial inocula were unaffected by cyA. Chemotaxis was within normal limits under all conditions. In addition, polymorphonuclear leukocytes from four renal transplant recipients receiving both cyA and prednisone demonstrated normal metabolic bursts and bacterial killing with both small and large inocula of S. aureus.     

Antikörperbildung gegen Poliovirus-N- und -H-Antigen bei Immunisierung von Meerschweinchen

Zusammenfassung Sieben Gruppen von Meerschweinchen zu je 15 Tieren wurden mit virulenten und attenuierten StÄmmen von Poliomyelitis immunisiert und die Antikörperbildung gegen N- und H-Antigen beobachtet. In allen Gruppen wurden zuerst H-Antikörper und spÄter N-Antikörper gebildet. Im weiteren Verlauf der Immunisierung nimmt bei Typ I und Typ II die Bildung von N-Antikörpern wesentlich schneller zu, so da\ die N-Titer bald höher sind als die H-Titer. Gleichzeitig reagieren zuerst mehr Versuchstiere mit H-Antikörper-Bildung, wÄhrend spÄter mehr Tiere N-Antikörper bilden.Bei der Immunisierung mit Typ III reagieren mehr Tiere mit Antikörperbildung gegen H als gegen N, gleichzeitig sind die H-Titer wÄhrend des ganzen Verlaufs höher oder ebenso hoch wie die N-Titer. Die Antikörperbildung gegen die ImpfstÄmme entsprach weitgehend dem Verlauf bei den virulenten StÄmmen. Die Reaktion des Organismus auf die Zufuhr von N- und H-Antigen Ändert sich im Laufe der Immunisierung. Die zu einem spÄteren Zeitpunkt vorgenommenen Booster-Injektionen vermögen das initiale übergewicht der H-Antikörper nicht wiederherzustellen, selbst wenn mehr H- als N-Antigen zugeführt wird.

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Antibody production versus poliovirus N and H antigen after immunisation of guinea pigs

Summary Seven groups of guinea pigs consisting of 15 animals each were immunized with virulent and attenuated strains of poliomyelitis virus. Subsequently the antibody production versus N and H antigen was studied. The animals of all groups responded primarily by production of H antibodies and later by N antibodies. During the further course of immunization the production of N antibodies was much faster for type I and II, thus anti N titers soon were higher than anti H titers. In addition, more animals responded initially by production of H antibodies, while later on more animals produce N antibodies. During the immunization with type III more animals produced H than N antibodies and H titers were always higher than N titers or equal. Antibody production to vaccination strains corresponded to a far extent to that of virulent strains. Response of the organism changes during the course of immunization. Booster injections given at a later time do not recall the initial peak of H antibodies, even if a greater dose H antigen is given than N.

     

Microphotometric investigation of oxidative enzyme activity in endometrial epithelium of rats after ovariectomy and injection of testosterone propionate

Activity of oxidative enzymes in the epithelium lining the uterine cavity and in the glandular epithelium of ovariectomized rats in the period of climacteric disorders was investigated by a comparative microphotometric method. An increase in lactate dehydrogenase (LD) and glucose-6-phosphate dehydrogenase (G6PD) activity and a decrease in succinate dehydrogenase (SD) and NAD- and NADP-diaphorase activity were found in the epithelial cells lining the uterine cavity. LD activity was increased in the glandular epithelium but SD, and NAD- and NADP-diaphorase activity was sharply reduced. Injection of testosterone propionate caused a marked increase in the activity of the oxidative enzymes studied in the endometrial epithelium of the rats compared with their activity in control rats and in rats not receiving the hormone.Research Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. Department of Obstetrics and Gynecology, Daghestan Medical Institute, Makhachkala. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 209–212, February, 1978.     

Enhanced proliferation of endogenous virus in Chinese hamster cells associated with microtubules and the mitotic apparatus of the host cell.

Chinese hamster ovary cells harbour intracytoplasmic virus-like particles of type A which are closely associated with sites of microtubule formation. We report here the enhanced proliferation of these particles and their release at the cell membrane by using either 5-bromodeoxyuridine or dibutyryl cyclic AMP. The extracellular mature particles are similar in morphology to retroviruses of type B. Close association of the type A virus precursors with microtubule organizing centres, i.e. kinetochores, centrioles and basal bodies, and with microtubules per se, is confirmed by studying the effects of the microtubule inhibitors Colcemid and vincristine sulphate. The role of microtubules in the activation and transport of the intracytoplasmic type A particles is discussed.     

Over-expression of TATA binding protein (TBP) and p53 and autoantibodies to these antigens are features of systemic sclerosis, systemic lupus erythematosus and overlap syndromes

The aim of this study was to determine the expression levels of p53 and TATA binding protein (TBP) and the presence of autoantibodies to these antigens in Asian Indian patients with systemic sclerosis (SSc), overlap syndromes (OS) and systemic lupus erythematosus (SLE). Fifty patients with SSc, 20 with OS, including mixed connective tissue diseases (MCTD), 20 with SLE, 10 disease controls (DC) and 25 controls (C) were studied. The over-expression of p53 and TBP antigen was determined quantitatively by sandwich enzyme-linked immunosorbent assay (ELISA), varies between four- and sevenfold higher in patients with SSc, OS and SLE, in comparison to DC and C. The expressed protein antigens were not present as free antigens but as immune-complexes. Autoantibodies to p53 were detected by ELISA in 78% subjects with SSc, 100% with OS and 80% with SLE. Autoantibodies to TBP were observed in 28% patients with SSc, 25% with OS and 15% with SLE. In comparison to healthy controls, the titre of antibodies to p53 was significantly higher in patients with SSc (P = 0.00001) than the patients with OS (P = 0.00279) and SLE (P = 0.00289), whereas the titre of antibodies to TBP was higher in patients with OS (P = 0.00185) than the SLE (P = 0.00673) and the SSc (P = 0.00986) patients. Autoantibodies to p53 and TBP were detected in all these patients and the levels of these two autoantibodies showed weak negative correlation with each other. We propose that the over-expression of these antigens might be due to hyperactive regulatory regions in the p53 and TBP gene.     

Inverted tandem ("mirror") duplications in human chromosomes: -nv dup 8p, 4q, 22q

We have studied 4 patients with inverted tandem duplications of parts of chromosomes, a hitherto rarely identified form of a structural rearrangement involving a single chromosome in man. In patients 1 and 2, the duplication involved parts of the short arm of chromosome 8 (regions 8p12 leads to 8p23 and 8p21 leads to 8p23, respectively). Both patients manifested certain characteristics of the mosaic trisomy 8 syndrome. Elevated levels of glutathione reductase (GSR) in their erythrocytes supported the interpretation of a partial duplication of chromosome 8 and indicated a regional localization for the GSR gene locus. In Partient 3, the distal half of the long arm of chromosome 4 was duplicated (region 4q23 leads to 4q35). Clinical evidence supported this interpretation, as Patient 3 resembled phenotypically the 13 reported cases with duplication of the distal 4q. The cytogenetic findings in Patient 4 suggested a possibly inverted duplication of 22q. The clinical correlation was less convincing due to the lack of a well-defined phenotype for trisomy 22. These chromosome aberrations had occurred de novo in all 4 cases. Although they involved different chromosomal regions, they might well have arisen by the same mechanism. Possible modes of origin that are discussed in detail include unequal exchange between homologous chromosomes, between chromatids of 1 chromosome or between strands of 1 DNA duplex.     

Immunohistochemical demonstration of migration inhibitory factor (MIF) in experimental allergic contact dermatitis.

The kinetics of appearance of MIF+ cells was investigated in experimental contact dermatitis using a monoclonal antibody (7D10) against murine MIF which was reacted with cryostat sections of tissues and detected by the indirect immunoperoxidase test. Four groups of BALB/c mice were investigated: (1) sensitized with 2,4-dinitrofluorobenzene (DNFB); (2) unsensitized controls; (3) tolerized; (4) unsensitized. A challenge dose of DNFB was applied to the ear of animals of groups 1-3 and of croton oil to those of group 4. Three phases could be distinguished in group 1: (a) an initial vascular and exudative reaction; (b) an early cellular phase; and (c) a late cellular phase. At zero time rarely any T lymphocytes (Lyt 1+; Lyt 2+) were seen in all four groups. Within less than 30 min venous endothelial cells became strongly MIF+. This was followed by an influx of monocytes/macrophages reaching a maximum of 72 h in group 1 and a slight peak at 12 h in groups 2 and 3. At 16-24 h in all groups the endothelial reaction weakened while many 7D10+ macrophages appeared in group 1. By double-labelling it was shown that lymphocytes were 7D10-. The influx of lymphocytes, part of which carried the T cell receptor, began at 12 h, reaching a maximum at 72 h in group 1. In groups 2 and 3 only a weak lymphocytic infiltrate developed which declined at 24 h. Group 4 developed an inflammatory reaction after the initial phase with similar kinetics as in group 1. The data suggest that an immune inflammatory reaction is preceded by a nonspecific reaction of the vascular endothelium and the mononuclear phagocytic system and that MIF is playing a central role in these events.