Metoprolol does not reduce platelet aggregability during sympatho-adrenal stimulation

Summary The possibility that -adrenoceptor blockers, especially ₁-selective agents might inhibit platelet function is of considerable interest, as this might be of pathophysiological importance in cardiovascular diseases. Platelet function, however, is difficult to assess and in vivo related data are scarce.The effect of one week of treatment with metoprolol 200 mg/day on platelet aggregability during mental stress (colour word conflict test; CWT) and low and high dose adrenaline infusions has been evaluated in a double-blind, placebo-controlled, cross-over study in 10 healthy male volunteers. Platelet function in vivo was assessed using ex vivo filtragometry, and the urinary excretions of -thromboglobulin (HMW -TG) and 11-dehydro-TxB₂ (a thromboxane metabolite). Conventional in vitro aggregometry and the urinary levels of 2,3-dinor-6-keto-PGF₁ (a prostacyclin metabolite) were also studied.During the interventions there was increased platelet aggregability in vivo, as filtragometry readings were shortened by 41±11% during high dose adrenaline infusion, urinary HMW -TG levels increased and urinary 11-dehydro-TxB₂ tended to increase. In contrast, platelet sensitivity to ADP in vitro was reduced. The urinary 2,3-dinor-6-keto-PGF₁ levels were increased during the interventions.Despite the cardiovascular and biochemical signs of -adrenoceptor blockade at rest and during the interventions, metoprolol failed to influence platelet function in vivo, as measured by ex vivo filtragometry, or urinary HMW -TG or 11-dehydro-TxB₂ levels. It tended rather to enhance the stress response measured by ex vivo filtragometry. Platelet aggregability in vitro and urinary 2,3-dinor-6-keto-PGF₁ levels were not altered by metoprolol.Thus, metoprolol was not found to reduce platelet aggregability in healthy male volunteers either at rest or during sympatho-adrenal activation. The effect of treatment may still differ in patients; studies in patients with ischaemic heart disease are under way.     

Hepatic levels of prostaglandins F2α and I2 (prostacyclin) and of thromboxane A2 in dogs developing hemorrhagic shock

Professorial Department of Surgery, L'vov Medical Institute. L'vov Branch, Kiev Research Institute of Hematology and Blood Transfusion. (Presented by Academician of the Academy of Medical Sciences of the USSR V. S. Savel'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 2, pp. 134–135, February, 1992.     

The ONG capsular lens,report of 100 implantations

This Capsular Lens (ONG, type IV, to be called O.C.L.) has been developed for routinely performed extracapsular cataract extraction with lens implantation. The fundamental surgical procedure was based on continuing experience with the bimanual aspiration-irrigation technique and system developed by the author in 1971. The biomechanical properties of the asymmetric partly flexible, haptic loops are designed to give tensionfree fixation in two capsular pockets. The plano-anterior position of the lens ensures well-defined irido-lenticular clearance and proper alignment of the convex side with the posterior capsule. Consequently no iridectomy or iridotomy is needed for proper aqueous flow.     

Noradrenergic and dopaminergic interactions in escape behavior: Analysis of uncontrollable stress effects

The effects of norepinephrine receptor blockade on the deficits of escape behavior induced by haloperidol and by inescapable shock were evaluated. Phenoxybenzamine, the -norepinephrine receptor blocker, was found to enhance escape behavior and to eliminate the disruptive effects of both inescapable shock and haloperidol. In contrast, the -norepinephrine receptor antagonist, propranolol, was without effect on behavior under any of these conditions, while the dopamine--hydroxylase inhibitor, FLA-63, disrupted performance. Like phenoxybenzamine, the norepinephrine receptor stimulant, clonidine, was found to eliminate the behavioral disruption produced by haloperidol. These somewhat paradoxical findings were discussed in terms of the contribution of DA-NE interactions in determining behavioral change in aversive paradigms.     

Unicentric osteosarcoma of bone with subsequent skeletal metastases

Five cases of unicentric osteosarcoma with subsequent skeletal metastases are reviewed. Skeletal metastases may occur prior to pulmonary metastases in such patients. Initial and periodic bone scanning is therefore justified since early detection of distant bone lesions may have important therapeutic implications. A classification of multiple site osteosarcoma based upon clinical, pathologic, and radiologic characteristics is proposed.     

Acid maltase deficiency in non-identical adult twins

Summary Acid maltase deficiency is described in non-identical adult twins. The onset of the disease can be traced into late infancy; the clinical picture is one of severe muscular dystrophy; respiratory insuficiency was the cause of death in one case. The autopsy showed the central nervous system, heart and liver to be spared. Glycogen filled vacuoles are found in skin, mesenchymal cells, small nerves and skeletal muscles. The light microscopic study of 9 different muscles showed extremely variable involvement ranging from normal appearance to overt vacuolization. A 6–20% residual acid -glucosidase activity was found in visceral organs, cultured fibroblasts and in some skeletal muscles. No satisfactory explanation can be given why this generalized acid -glucosidase deficiency produces a selective involvement of skeletal muscles. If compared with infantile AMD (Pompe's disease) our cases have a much higher residual acid -glucosidase activity and show the presence of an antigenically detectable protein.From our study and from a similar report in the literature (de Barsy et al., 1975), it appears that a combined approach of light microscopy, electron microscopy and biochemical analysis (determination of acid -glucosidase) is necessary to make a diagnosis of AMD in adults.Dr. Th. de Barsy is a Research Fellow of the Fonds National de la Recherche Scientifique.     

高效液相色谱系统聚类分析方法在风轮菜属药材分类中的应用

目的 :探讨高效液相色谱技术应用于风轮菜属中药的鉴定研究。方法 :利用高效液相色谱提供药材的内在成分信息 ,结合模式识别技术 ,对风轮菜属植物进行了分类及鉴定。结果 :色谱数据的系统聚类结果得到了预期效果 ,这对于研究风轮菜属药材的类别及近缘性提供了依据。结论 :本方法具有简便、快捷、重现性好等优点。     

重组水蛭素治疗兔弥散性血管内凝血

目的:观察重组水蛭素对治疗脂多糖致兔弥散性血管内凝血模型的抗凝疗效。方法:建立兔脂多糖弥散性血管内凝血模型,18只新西兰大白兔随机分为3组,静脉注射脂多糖的同时分别予生理盐水、普通肝素和重组水蛭素,于注射脂多糖前,注射后2,4,6h检测血小板计数、活化部分凝血活酶时间、抗凝血酶Ⅲ、纤维蛋白原、血清纤维蛋白降解产物(FDP);并观察心、肺脏器的病理变化。结果:模型组兔活化部分凝血活酶时间明显延长,血小板计数和纤维蛋白原显著降低,抗凝血酶Ⅲ活性明显下降,与肝素组相比重组水蛭素组血小板和纤维蛋白原消耗减少,抗凝血酶Ⅲ活性下降程度减轻。所有实验动物血清FDP变化无统计学差异。病理检查模型组心、肝、肺、肾、脾脏可见微血栓形成,重组水蛭素组均未见微血栓形成。结论:重组水蛭素具有明显的抗凝作用,可有效治疗弥散性血管内凝血。