Limits of phagocytic power of macrophages

The ability of peritoneal macrophages to take up different doses of antigen (sheep's erythrocytes) and of antigens differing in physicochemical properties (sheep's erythrocytes, rat erythrocytes, and typhoid vaccine) was studied. An increase in the dose of sheep's erythrocytes injected many times over had no effect on the quantity of antigen ingested by the macrophages within a definite time interval. In macrophages taken at short periods after injection of erythrocytes of the different species of animals into the mice, ability to take up these erythrocytes in vitro was sharply inhibited. Preincubation of macrophages (in vivo or in vitro) with all the antigens tested sharply increased their ability to phagocytose typhoid vaccine.Laboratory of Physiology and Regulation of Immunity, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsina, Vol. 84, No. 7, pp. 58–61, July, 1977.     

Dual effects of endogenous DNases on transcriptionally active and inactive chromatin

Experiments on resting hepatocytes with inactive c-fos gene and active albumin gene. We revealed that DNA of the transcribed gene is less susceptible to the influence of endogenous Ca2+/Mg(2+)-dependent DNases in matrix-associated and highly soluble chromatin fractions. In the fraction of low soluble chromatin active gene was more accessible for DNases. Our results indicate that activity of endogenous DNases can change in the transcribed gene locus.     

Expression of transforming growth factor-beta1 and transforming growth factor-beta receptors in hepatocellular carcinoma and dysplastic nodules.

In this study we analyzed by immunohistochemistry the expression of TGF-beta1 protein and TGF-beta receptors I and II in 4 low-grade dysplastic nodules, 2 high-grade dysplastic nodules, 6 early, 22 small, and 62 advanced hepatocellular carcinomas. The expression of TGF-beta1 protein by hepatocytes was decreased in advanced hepatocellular carcinoma compared with small or early hepatocellular carcinoma(P < .05). Frequent and intense staining of TGF-beta1 protein was noted in the sinusoidal endothelium of advanced hepatocellular carcinomas despite of its decreased staining in hepatocellular carcinoma cells. Reduced expression of TGF-beta receptors I and II compared with surrounding nontumorous tissue were noted from the early hepatocellular carcinoma stage suggesting that down-regulation of TGF-beta receptors is correlated with progression from premalignant to malignant phenotype. Reduced expression of both TGF-beta1 and TGF-beta receptor II in neoplastic hepatocytes were also significantly correlated with increased tumor size and increased proliferative activity(P < .05). These findings suggest that during hepatocarcinogenesis, the inhibitory effects of TGF-beta1 protein on hepatocellular carcinoma cells is outweighed by its effects on stromal elements, which, overall, contributes indirectly to a tumor growth stimulatory environment. Also, the growth-inhibitory effects of TGF-beta1 may have been further negated by reduced TGF-beta receptors on hepatocellular carcinoma cells.     

Effect of Parmidine (pyridinolcarbamate) on platelet aggregation,blood coagulation,and fibrinolysis

The effect of Parmidine (pyridinolcarbamate) on platelet aggregation, blood coagulation, and fibrinolysis was studied in rabbits. After direct addition of Parmidine to platelet-enriched plasma aggregation of the platelets produced by serotonin (5-HT) and adrenalin was reduced. After oral administration of Parmidine to animals, aggregation induced by ADP, 5-HT, and adrenalin was inhibited, blood coagulation was reduced, and fibrinolysis was accelerated.Laboratory of Pharmacology, S. Ordzhonikidze All-Union Pharmaceutical Chemical Research Institute. Department of Pharmacology, Therapeutic Faculty, Moscow Medical Stomatological Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 322–324, March, 1976.     

肺动脉高压的发病机制、治疗进展

肺动脉高压是多种因素导致的内皮功能受损所致,病理机制的研究进展为治疗开辟了新思路,提出了如钾离子通道开放剂、内皮素受体拮抗剂、蛋白激酶C抑制剂、PDE-5抑制剂和血栓素抑制等治疗方法.     

Classification of instruments for cryosurgery

Conclusions 1. Cryosurgical instruments can be divided into passive and autonomous cryoprobes and cryoprobes with delivery of the coolant from a separate reservoir. 2. To freeze easily accessible organs and tissues to a depth of 5 mm it is best to use passive cryoprobes with a copper core. 3. Autonomous cryoprobes can be used for freezing organs and tissues having a volume not more than 10–25 cm³. Cryoprobes with delivery of the coolant from a separate reservoir must be used when freezing a larger volume. Physicotechnical Institute of Low Temperatures, Academy of Sciences of the Ukrainian SSR, Kharkov. Translated from Meditsinskaya Tekhnika, No. 4, pp. 34–36, July–August, 1971.     

Thermotropic liquid crystalline polymers, 4. Study of crystalline and liquid-crystalline comb-like polymers with mesogenic side groups by IR spectroscopy

The IR spectra (in the region of 400–3600 cm^?1) of comb-like polymers in crystalline, liquid-crystalline, and fluid isotropic phases were studied, and the effect of the chemical structure of the long side chains on the crystalline and liquid-crystalline states were examined. The spectroscopic criteria of phase transitions in comb-like polymers were established and the fragments of the side chains involved in the formation of the liquid-crystalline phase, were determined.