RGM1, a cell line derived from normal gastric mucosa of rat

Brainstem evoked potentials (BAEPs) were determined in three groups of male prisoners of war (POWs) released from detention camps and a control group. The first group comprised 21 POWs in whom BAEPs were determined 10-60 days after release (group I). The second group comprised 24 POWs in whom BAEPs were determined 6-9 months after release (group II), and the third group comprised 22 POWs in whom BAEPs were determined 12-18 months after release (group III). The control group comprised 32 subjects. The following changes were found in relation to the control group: in group I significantly longer interpeak latencies (IPLs) P1-P3; in group II significantly longer IPLs P1-P3 and P3-P5; and in group III significantly longer IPLs P1-P3. The subjective symptomatology of the POWs and the results of a routine examination indicate subclinical functional changes of the central nervous system, reflecting the dynamics of these changes. It is suggested that the basis of these changes may be a demyelinization intrathecal process, which occurred as a result of immunological changes during prolonged and intensive post-traumatic stress syndrome.     

Serum antibody responses of foals to virulence-associated 15- to 17-kilodalton antigens of Rhodococcus equi

Antibody (Ab) sensitized sciatic nerve Schwann cells (SchC) of 2-day-old rats (SchC/2d) were significantly more susceptible to cytolysis by both heterologous, guinea pig (GP), and homologous rat serum complement (40 +/- 3.8% and 21.2 +/- 3.1%, respectively) than SchC of 6-day-old rats (SchC/6d) (7.9 +/- 5.9% and 2.6 +/- 3.1%, respectively). To determine if resistance to complement (C)-mediated cytolysis correlated with expression of membrane proteins which regulate C activation, we used Western blot and FACS analysis. Binding of specific polyclonal Ab demonstrated similar concentrations of Crry, a regulator of C3 convertase formation, on plasma membranes of SchC 2d and 6d. During C activation, both C3b deposition and iC3b formation were greater on SchC/6d than on SchC/2d and the C3b deposition did not correlate with enhanced cytolysis. In contrast, 2.1-fold more rat CD59, a regulator of C8 and C9 incorporation into C5b-9, detected with Western blot on SchC/6d compared with SchC/2d was confirmed by FACS. Further, both rat and GP C8/C9 lysed SchC/2d expressing human C5b-7 (20.1 +/- 3.7 and 21.6 +/- 4.7%, respectively), while only GP C8/C9 caused cytolysis of 10.7 +/- 4.3% SchC/6d expressing hu C5b-7 and rat C8/C9 did not (0.5 +/- 0.5%). Preincubation of SchC/6d with an F(ab)2 fragment of an mAb to rCD59 with blocking capacity, increased cytolysis mediated by rat serum C more than 6-fold to 16.7 +/- 3.0% but only 1.7-fold (maximum cytolysis 37.4 +/- 11.2%) in SchC/2d. Our data suggest that expression of rat CD59 on SchC increased almost two-fold between postnatal days 2 and 6, and this increased expression on more terminally differentiated SchC is a significant factor in regulating terminal complement complex formation and limiting cytolysis of rat SchC by homologous serum complement.     

Activation of ecto-5'-nucleotidase by protein kinase C attenuates irreversible cellular injury due to hypoxia and reoxygenation in rat cardiomyocytes

Adenosine, synthesized by ecto-5'-nucleotidase, is cardioprotective against ischemia and reperfusion injury. We have previously reported that activation of protein kinase C increases ecto-5'-nucleotidase activity of the rat cardiomyocytes, raising the possibility that activation of protein kinase C protects cardiomyocytes from the irreversible cellular injury via activation of ecto-5'-nucleotidase. To test this hypothesis, cardiomyocytes were isolated from adult male Wistar rats and suspended in modified HEPES-Tyrode buffer solution. The cardiomyocytes were incubated with and without exposure to methoxamine (1 x 10(-6) mol/l) or phorbol 12-myristate 13-acetate (PMA. 1 x 10(-8) mol/l). Ecto-5'-nucleotidase activity increased 15 min after the onset of an exposure to either methoxamine or PMA. Adenosine release during hypoxia and reperfusion was augmented in the methoxamine- and PMA-pretreated cardiomyocytes compared with the untreated cardiomyocytes, which was inhibited by alpha, beta-methyleneadenosine 5'-diphosphate (AOPCP), an inhibitor of ecto-5'-nucleotidase. Irreversible cellular injury assessed by the extent of release of lactate dehydrogenase and the trypan blue exclusion test following 60 min of hypoxia and 60 min of reoxygenation was attenuated in the methoxamine- and PMA-pretreated cardiomyocytes compared with the untreated group, which was also blunted by AOPCP and 8-sulfophenyltheophylline, an adenosine receptor antagonist. An adenosine A1 receptor agonist, N6-cyclohexyladenosine, restored the cardioprotection under the treatment with PMA and AOPCP. We conclude that activation of ecto-5'-nucleotidase via protein kinase C contributes to the attenuation of the irreversible injury of the rat cardiomyocytes due to hypoxia and reoxygenation.     

Endoscopic observation of the gastric mucus in vivo stained with azure A

Gastric mucus was stained with Azure A, a cationic dye, which had the highest affinity with macromolecular constituents of the mucus, under such conditions as 0.2% Azure A-0.5% NaHCO3 solution (pH 8.1) in dye concentration, staining for ten minutes, 37 degrees C in reaction temperature and the salt concentration and ionic strength below 6.0 x 10(-2). In rat and resected human stomachs, gastric mucus was clearly stained under these conditions. In human subjects, the in vivo stained muscu was observed endoscopically. The pyloric gland region. The difference was seen in the pattern of the gastric area between the fundic and pyloric gland region. Histological examination revealed that only the mucous layer was stained with Azure A. The stained macromolecules in the mucus and factors affecting the staining were discussed.     

Proton magnetic resonance spectroscopy in patients with glial tumors: a multicenter study

Budding yeast (Saccharomyces cerevisiae) Rap1p has been expressed in fission yeast (Schizosaccharomyces pombe) under the control of the regulatable fructose bisphosphatase (fbp) promoter. When the fbp promoter was derepressed, cells containing the complete RAP1 gene failed to show any significant growth, suggesting that Rap1p is toxic. A derivative of Rap1p that has a temperature-sensitive mutation in the DNA-binding domain was not toxic in cells grown at 37 degrees C, a temperature at which DNA binding by rap1p(ts) is severely inhibited. Removal of a short region downstream of the DNA-binding domain, including a region previously shown to be essential for Rap1p toxicity in budding yeast, also abolished the toxic effect. The toxic effect of Rap1p has therefore been conserved between two distantly related yeasts. In budding yeast, overexpression of Rap1p also caused changes to the lengths of the telomeric repeats. No effects on telomeres were detected in fission yeast.     

Natriuretic peptide family as a novel antimigration factor of vascular smooth muscle cells

Vascular smooth muscle cell (SMC) migration is proposed to be an important process in the initiation and/or progression of atherosclerosis. The present study examined the effects of the natriuretic peptide family (atrial, brain, and C-type natriuretic peptides; ANP, BNP, and CNP) on the migration of cultured rat SMCs, using Boyden's chamber methods. Fetal calf serum (FCS) and platelet-derived growth factor (PDGF)-BB potently stimulated SMC migration. Rat ANP(1-28), rat BNP-45, and rat CNP-22 clearly inhibited SMC migration stimulated with FCS or PDGF-BB in a concentration-dependent manner. CNP-22 had the most potent inhibitory effect compared with other natriuretic peptides. When PDGF-BB-induced migration was separated into chemotactic and chemokinetic activities, the chemotactic component was strongly inhibited by these natriuretic peptides. Such inhibition by these natriuretic peptides was paralleled by an increase in the cellular level of cyclic GMP. The addition of a cyclic GMP analogue, 8-bromo cyclic GMP, and an activator of the cytosolic guanylate cyclase, sodium nitroprusside, significantly inhibited FCS- and PDGF-BB-stimulated migration in a concentration-dependent manner. These results suggest that natriuretic peptides, especially CNP-22, inhibit FCS- or PDGF-BB-stimulated SMC migration at least in part through a cyclic GMP-dependent process. Thus, the natriuretic peptide family may play a role as an antimigration factor of SMCs under certain circumstances.