Antihypertensive effect of amlodipine compared with nifedipine retard in patients with mild and moderate essential hypertension

OBJECTIVE: The present study was undertaken to evaluate the efficacy and safety of amlodipine for hypertension treatment in comparison with nifedipine retard. METHODS: We examined 31 patients with arterial blood pressure approximately 155-165 mmHg/100-105 mm Hg at the beginning of the trial. It was a randomized double-blind, parallel-group trial including two groups of patients. Patients of the first group were given active amlodipine and nifedipine retard placebo during 6 weeks, while the second group was given active nifedipine retard and amlodipine placebo. Statistical analysis was made using the paired Student's t-test, chi-square test and ANOVA test. RESULTS: At end point we observed significant decrease in arterial blood pressure after treatment of both drugs. The treatment with nifedipine retard increased the mean heart rate of patients. Amlodipine therapy in comparison to nifedipine retard did not change the heart rate in treated patients. Safety parameters: SGOT, SGTP, creatinine and others were in laboratory norms ranges. CONCLUSION: Amlodipine proved to be an effective, more safe and better-tolerated therapeutical alternative for hypertension management than nifedipine retard.     

Histamine receptors in the isolated rat stomach fundus and rabbit aortic strips

The effects of histamine and 4-methylhistamine (a selective H2-agonist) were studied on the isolated rat stomach fundus and rabbit aortic strips superfused with Krebs' solution. The contraction induced by histamine was found to be mediated via mepyramine-sensitive H1, while the relaxation induced by the amine through metiamide-sensitive H2-receptors in both smooth muscles. Prior addition of metiamide to the superfusion medium caused an apparent dose-related potentiation in the response to histamine on the aortic strip but not on the stomach fundus strip. The relaxation produced by histamine on the aortic strip demonstrated when the muscle was pretreated with mepyramine and contracted by angiotensin II or serotonin. Metiamide competitively inhibited the relaxation induced by histamine but not by papaverine in both smooth muscles. 4-Methylhistamine produced only a relaxation in the rat stomach fundus which could be competitively inhibited by metiamide. This analog had no agonistic property in the aortic strip. From these results it was concluded that histamine H1-and H2-receptors are present in both smooth muscles. The predominant contractile effect of histamine is mediated through H1-receptors and the relaxing effect of the amine through H2-receptors.     

Two cases of external ophthalmomyasis (author's transl)

After a brief survey of Hungarian references the author reports on two cases of ophthalmomyasis externa. The organism was shown to be present oestrus ovis in one instance. The treatment with carbon-tetrachloride might be considered as a new and efficacious therapy.     

Biochemical and molecular biological characterization of a lipase produced by the fungus Rhizopus delemar

The results of a comprehensive biochemical and molecular biological investigation of the lipase produced by the mycelial fungus Rhizopus delemar are described. This enzyme cleaves and synthesizes primary esters and related bonds, exhibits 1,3-positional selectivity in its actions on glycerides, and is a member of a family of enzymes that have been widely used in applied biocatalysis. Use of glycerol as main carbon source rather than glucose or lipid supported mycelial growth and lipase production. The enzyme was purified to homogeneity and characterized. Pure lipase was crystallized and its three-dimensional structure determined. The enzyme was found to adopt a configuration similar to those of other members of its homologous family. The structural data also indicated that lipases possess greater configurational mobility than had been previously appreciated. A complementary DNA clone was isolated that contained the full length lipase gene. The nucleic acid sequence of this cDNA indicated that it was initially synthesized as a preproenzyme, and allowed determination of the complete predicted amino acid sequence of the lipase, and its comparison to the sequences of related enzymes. Truncated forms of the cloned cDNA were produced that encoded either mature or prepro-lipase. These DNAs were introduced into a tightly regulated E. coli expression system, overcoming the toxicity of the enzyme while also allowing overproduction of lipase. Molecular modelling was employed to guide the rational mutagenesis of the enzyme, identifying sites within the substrate binding region that regulated substrate selectivity. Mutant lipases were generated with altered substrate specificities, creating novel enzymes and beginning the definition of structure-function relationships in the lipolytic enzymes.     

有限精度时间自动机的可达性检测

为了缓解状态空间爆炸问题,减小模型检测过程中生成的状态空间,加快模型检测速度,引入有限精度时间自动机(finite precision timed automata,简称FPTA)作为实时系统的形式模型,并提出了一种数据结构SDS(series of delay sequence)符号化表示状态空间中的状态集.FPTA只记录时钟变量的整数值及时钟变化的先后次序,从而减小生成的状态空间.在一定的时间约束下,Alur与Dill提出的时间自动机的可达性检测可简化为FPTA的可达性检测.举例描述了状态空间的生成过程和表示方法.最后,列出部分初步的实验结果,分析了SDS的特点及不足.     

Complement C5a anaphylatoxin fragment causes apoptosis in TGW neuroblastoma cells

Human neuroblastoma TGW cells express a C5a anaphylatoxin receptor-like molecule termed neuronal C5a receptor. A C5a-receptor fragment peptide (termed PR226-multiple antigenic peptide) can induce rapid apoptosis in TGW cells via neuronal C5a receptor-associated signal transduction pathways. In order to analyse role of activated complement system in neurodegeneration, TGW cells were exposed to an oligomer form of a C5a fragment (amino acids: 37-53) peptide termed PL37-multiple antigenic peptide. Upon treatment with PL37-multiple antigenic peptide, an increased nuclear c-fos expression was shown within 30 min. DNA fragmentation, a hallmark of apoptosis, was noted within 4 h. Extracellular administration of 100 nM PL37-multiple antigenic peptide evoked inward calcium current pulses. At higher doses (0.5 microM-1 microM), PL37-multiple antigenic peptide evoked higher current pulses, followed by an irreversible, high inward current. To exert its apoptotic effect, PL37-multiple antigenic peptide utilizes a pertussis toxin-sensitive signal transduction pathway associated with the neuronal C5a receptor. Activation of the complement system and therefore release of C5a has already been reported in Alzheimer's disease. In addition, the presence of the Kunitz-type proteinase inhibitors indicates an impaired protease function and a possible abnormal fragmentation of C5a anaphylatoxin. Our data suggest that neurons expressing neuronal C5a receptor are more vulnerable to the apoptosis associated with the neuronal C5a receptor and the possibility that abnormal activation of C5a receptor and C5a anaphylatoxin fragments might be involved in the pathogenesis of Alzheimer's disease.     

MR arthrography of the shoulder: variants and pitfalls

Use of magnetic resonance arthrography to evaluate pathologic conditions of the shoulder is becoming widespread. However, normal anatomy or anatomic variations can cause interpretive errors. The most common variations occur at the origins of the glenohumeral ligaments (GHLs) and the insertion of the joint capsule. Among the GHL variants, common origin of the superior and middle ligaments is the most frequent followed by thinning, thickening, or absence of a ligament, most often the middle one. Absence or thinning of one ligament is sometimes associated with thickening of another or changes in the size and shape of the anterior capsular recesses. Common normal variants of the labrum include foramen sublabrum (detachment of the anterosuperior labrum from the glenoid margin) and the Buford complex (absence of the anterosuperior labrum in association with a thick middle GHL). Pitfalls related to the arthrographic technique include (a) visualization of a deep sulcus between the insertion of the long head of the biceps tendon and the superior labrum and (b) an apparent type III capsular insertion due to overdistention of the capsule by injected contrast material.     

The influence of vasectomy and vasovasostomy on testicular ATPases, cAMP, ABP and androgen receptor in rabbits

The present study was performed to further clarify the influences of vasectomy on functions of testis and to disclose the possible mechanisms of infertility after vasovasostomy (VV). Thirty-one rabbits were divided into sham-operated control group (C), vasectomy control group (V), VV fertility group (VaF) and VV infertility group (VaI). Serum testosterone (ST) level, testicular cAMP, androgen binding protein (ABP), nuclear androgen receptor (NAR) concentrations, testis cell membrane Na(+)-, K(+)-ATPase, Mg(2+)-ATPase activities, sperm density and testis weight were measured. Vasectomy resulted in significantly reduced cAMP, Na(+)-, K(+)-ATPase, Mg(2+)-ATPase, testis weight and increased ABP; VV completely restore testis weight in VaF and VaI, Na(+)-, K(+)-ATPase, Mg(2+)-ATPase in VaF, partly cAMP in VaF and VaI, Na(+)-, K(+)-ATPase, Mg(2+)-ATPase in VaI, but did not restore ABP. The NAR content in VaI was significantly lower than those in C, VaF and V. No statistical differences among 4 groups were seen in Kd values for [3H]-T. ST levels in VaF, VaI and V were insignificantly different compared with C, but the value in VaF was higher than that in VaI (p < 0.05). Sperm density after VV reached 122 +/- 62 x 10(6)/ml in VaF and 10 +/- 24 x 10(6)/ml in VaI, both in VaF and VaI were significantly low compared with C (p < 0.001), and the value in VaI was remarkedly lower than that in VaF (p < 0.001). It was shown that sperm density was positively correlated with cAMP content, Na(+)-, K(+)-ATPase, Mg(2+)-ATPase activities, but negatively with ABP. These results suggest that vasectomy gives rise to damage to the testis, and vasovasostomy does not appear completely effective in reversing testicular changes.