Mechanisms of polyploidization of mouse cardiomyocytes

Most ventricular cardiomyocytes in mice aged 5–6 days are polyploid cells. By this time 60% of the cardiomyocytes have become binuclear and a further 10% have become mononuclear polyploid cells. Binuclear cardiomyocytes are formed as a result of acytokinetic mitosis, mononuclear tetraploid cells as a result of termination of mitosis in the initial phases.Laboratory of Cytology, N. K. Kol'tsov Institute of Developmental Biology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 219–222, February, 1980.     

The involvement of glutamatergic transmission in the mechanism of movement disorders induced by reversive rotation of white mice

The ability of the selective non-competitive NMDA receptor blocker MK-801 and a series of new glutamate antagonists—the adamantane derivatives IEM-1754 and IEM-1857 and phencyclidine (IEM-1925)—to prevent movement disorders induced by reversive rotation in mice was studied. I.p. MK-801 at a dose of 0.15 ml and IEM-1754 at a dose of 5.0 mg/kg prevented the development of akinesia in response to reversive rotation, as effectively as scopolamine, a known agent which provides effective prophylaxis for movement diseases. IEM-1857, the quaternary analog of IEM-1754, was not effective. IEM-1925 significantly increased the responses of mice to reversive rotation, possibly because of its high activity in relation to other subtypes of glutamate receptors. These data provide evidence for the involvement of glutamatergic transmission in the mechanism of movement disorders of vestibular origin. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 4, pp. 497–501, May, 1999.     

Cocaine or delta 9-tetrahydrocannabinol does not affect cellular cytotoxicity in vitro

Cocaine or delta 9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, has no effect on in vitro cytotoxicity mediated by natural killer (NK) cells and cytotoxic T-lymphocytes (CTL) at concentrations similar to those observed in vivo.     

Certain characteristics of myocardial contractility of isovolumic dog heart at randomly variable heart rhythm

Summary The relationship heart rate-left ventricular pressure was investigated in the isolated canine heart perfused with constant pressure at different preloads. Rhythmical stimulation was performed with constant stimulus interval duration and with stimulus intervals randomly changed near the average value (150–200 stimuli in series).Correlation and dispersion function analysis show that rhythm dispersion had a negative inotropic effect which was independent of the preload of the ventricle in the range of 120–180 beat/min, but this dependence occurred with low rates of stimulation.This method is proposed for the assessment of contractility under conditions of heart rate variations (physiological and pathological arrhythmias).     

抑酸抗菌药联合治疗消化性溃疡的疗效观察

68例经胃镜证实的消化性溃疡患者,随机分成两组,分别接受常规抑酸护膜及抑酸抗菌联合治疗。服药法：常规治疗组为雷尼替丁0．15g,2次／d,三钾二橼络合铋120mg,4次／d,抗菌治疗组为三钾二橼络合铋120mg,4次／d,甲硝唑0．2g,4次／d,阿莫西林250mg,4次／d,均连服4周为一疗程,结果两组治愈率分别为73％（22／30）和87％（33／38）,而追踪观察治愈者1年复发率却分别为68％（15／22）和3％（1／33）。结果表明应用抑酸抗菌联合治疗消化性溃疡,具有症状缓解迅速、逼反应少,价格低、病人依从性好等优点,是一种较理想的消化性溃疡的治疗方案。     

灌洗法一期叻除吻合术在左侧梗阻性结肠癌中的应用

目的：探讨左半结肠癌并梗阻一期切除吻合的可行性。方法：术中灌洗肠内容物,术后吻合口减压。结果：1995年至1999年所遇左侧梗阻性大肠癌中选择5例用此方法吻合成功。结论：左侧梗阻性大肠癌,只要掌握好手术指针。术中充分灌洗肠内容物,术后扩肛可一期切除吻合。