Studies on calcium-stimulated adenosine triphosphatase in the albino rabbit dental pulp. Its subcellular distribution and properties.

The subcellular distribution of calcium-stimulated adenosine triphosphatase in the albino rabbit dental pulp was studied. The purity of the microsomal fraction was examined by measuring the marker enzymes and by electron microscopic observation. Some properties of calcium-stimulated adenosine triphosphatase were investigated.     

Nicorandil attenuates myocardial acidosis during coronary occlusion in dogs.

In dogs anaesthetized with pentobarbitone, the left anterior descending coronary artery (LAD) was partially occluded. Before and 30 min after partial occlusion, the myocardial pH was 7.52-7.54 and 6.89-6.91, respectively. Nicorandil (50 micrograms kg-1, i.v.) increased the pH that had been reduced by partial occlusion and this effect lasted at least 60 min. Thus nicorandil attenuates ischaemic myocardial acidosis.     

Beta-lactam antibiotics resistant Rothia dentocariosa from infected postoperative maxillary cyst: studies on R-plasmid and beta-lactamase

A cephalexin and penicillin G resistant strain of Rothia dentocariosa was clinically isolated from pus of infected postoperative maxillary cyst. The strain contained multiple plasmids. Plasmid curing tests with rifampicin eliminated cephalexin and penicillin G resistant phenotypic functions and 47 megadalton plasmids from the strain. Beta-Lactamase isolated from the strain hydrolyzed cephalosporin more efficiently than penicillin.     

Potentiation of tumoricidal properties of murine macrophages by Nocardia rubra cell wall skeleton (N-CWS)

Intraperitoneal injection of squalene-treated cell wall skeleton of Nocardia rubra (N-CWS) caused increase in number of peritoneal exudate cells (PEC). Adherent macrophages obtained from N-CWS-treated PEC suppressed growth of methylcholanthrene-induced fibrosarcoma (Meth-A), when injected intradermally with the tumor cells into BALB/c mice. The macrophages showed strong cytotoxicity against Meth-A cells in vitro. When treated with 10 micrograms/ml of N-CWS in vitro, proteose peptone-induced macrophages acquired tumoricidal property but resident macrophages showed no cytotoxicity after the treatment. In the supernatant of spleen cells cultured for 72 hours in the presence of N-CWS (10 micrograms/ml), the presence of (a) factor(s) with macrophage activating effect was observed. This factor, shown to be identical to macrophage activating factor (MAF) in molecular weight, showed synergy with N-CWS in potentiating macrophage cytotoxicity against tumor cells.     

Effect of sotalol on ischemic myocardial pH in the dog heart

Summary In dogs anesthetized with pentobarbital, the left anterior descending coronary artery (LAD) was occluded partially so that the LAD flow could be reduced to 1/2 to 1/3 the original flow (partial occlusion). Myocardial pH was recorded continuously by the use of a micro glass pH electrode inserted in the area to become ischemic by partial occlusion. Before partial occlusion, myocardial pH was 7.51–7.66. Partial occlusion reduced the pH by 0.63–0.72.Sotalol (5 mg·kg^–1, i.v.) increased the pH (by 0.45) that had been reduced by partial occlusion, with a marked decrease in heart rate (about 70 beats·min^–1) and a slight decrease in blood pressure (about 10 mm Hg in systolic pressure). Even when the sotalol-induced decrease in heart rate was prevented by pacing the heart, sotalol (5 mg·kg^–1, i.v.) increased the pH (by 0.43) of myocardium in which LAD was partially occluded. The pH of the non-ischemic normal heart, however, was not influenced by the injection of sotalol (5 mg·kg^–1, i.v.)It is concluded that the effect of sotalol to increase the pH of the ischemic heart is not related to the decrease in heart rate produced by the drug injection.     

Syntheses and Immunological Effects of Thymic Humoral Factor-γ2 and Its Phe7-Substituted Analogues

Abstract: Thymic humoral factor-γ2 and five analogues modified at position 7 with various phenylalanine derivatives were synthesized by a solid-phase method. The synthetic peptides were tested for their effects on the impaired blastogenic response of phytohemagglutinin-stimulated T lymphocytes of uremic patients with infectious diseases. The synthetic thymic humoral factor-γ2 enhanced the blastogenic response of T lymphocytes in the blood of the 2 patients tested. Of the synthetic peptides, [Phe(4F)⁷]thymic humoral factor-γ2 exhibited the most potent effect.     

Cerebral protective effect of flunarizine in a canine model of cerebral ischaemia

To test the effect of flunarizine on cerebral ischaemia, 15 dogs were subjected to ischaemia, using the 'canine model of the completely ischaemic brain regulated with a perfusion method' in which the cerebral blood flow (CBF) can be fully regulated. Five animals served as untreated controls, 10 received flunarizine, a calcium antagonist (1 mg/kg in 5 dogs and 3 mg/kg in 5 dogs), before the ischaemic period. After 1 h CBF was restored and recovery of the electrical activity of the brain and the degree of brain swelling were observed for 3 h. At the end of the experiments, the degree of extravasation of Evans blue was examined. Remarkable recovery of EEG was found in the groups given flunarizine when compared with untreated controls. However, no significant difference was found between untreated controls and flunarizine treated groups for the degree of brain swelling and the degree of extravasation of Evans blue. These results suggest that the treatment of flunarizine is of benefit for functional recovery against cerebral ischaemia, but does not suppress ischaemic brain oedema.     

Histopathological study of experimental periodontitis in rats--ultrastructures, permeability, immunohistochemistry, and morphometric analysis in both pocket and long junctional epithelial

To elucidate the biological characteristics of both pocket and long junctional epithelia in experimental periodontitis, elastic rubber was inserted between the first and second molars of the left maxilla in rats. The rubber was removed after a week. An immunohistochemical study using anti-laminin and permeability experiments using peroxidase were conducted; examinations were made of ultrastructures and lanthanum; and a morphometric analysis was made of the distribution of capillaries immediately below the epithelium. Results: 1. Periodontal pockets formed from 5 days to 2 weeks after removal of the rubber. The long junctional epithelium was appearent from the fourth week after removal. Immunohistochemical study showed that laminin was located at the internal and external basal laminae in the long junctional epithelium but not on the surface of the pocket epithelium. 2. Electron microscopy showed the pocket epithelium to consist of flattened cells aligned parallel to the tooth surface in the coronal portion. The epithelium, which included numerous vacuoles, manifested especially wide intercellular spaces in which a large number of polymorphonuclear leukocytes were evident. Bacteria surrounded by neutrophils could be seen on the surface of the cementum in the pocket. Invading neutrophils split the epithelium at the central portion of the pocket. In the apical portion, the epithelium formed spindles that adhered to the cementum by means of half-desmosomes. Many neutrophils and fenestrated capillaries were observed in connective tissue immediately below the epithelium. 3. The long junctional epithelium consisted of 2 or 3 cell layers aligned parallel to the tooth surface. Intercellular spaces in the long junctional epithelium were as wide as those in the pocket epithelium and contained a small number of lymphocytes and a few neutrophils. Half-desmosomes were detected between the epithelial cells and the cementum. From the central to the apical region, epithelial tissues assumed a knife-edge form. Desmosomes and gap junctions occurred among these cells. Dense granules containing a limiting membrane and homogeneous electron-dense material were observed int he peripheral cytoplasm. Although fibroblasts aligned parallel to the epithelium occurred in them, few collagen fibers, inflammatory cells and capillaries were to be recognized in the connective tissue. 4. Permeability experiments in the pocket and the long junctional epithelium produced analogous results. Light microscopy showed that, in both epithelia, peroxidase penetrated into intercellular spaces and leaked into the pocket. Electron microscopy showed that, as an electron-dense material, lanthanum was detected in intercellular spaces and connective tissues.(ABSTRACT TRUNCATED AT 400 WORDS)