Withdrawing Long-Term Diuretic Treatment Among Elderly Patients in General Practice

The aim of this study was to elaborate, implement and evaluatea strategy for discontinuation of long-term diuretic treatmentin elderly patients in general practice. Thirty-three patientswere enrolled for a supervised step-down and withdrawal of diuretics.After withdrawal, the patients were followed up for 6 monthsor until diuretic treatment was re-established. Withdrawal wassuccessful according to the protocol in 18 cases. Diuretic withdrawalfailed and the treatment was re-established in 15 cases, fourof which were sudden cardiovascular events. Most withdrawalfailures were identified by routine examinations through thefollow-up programmes, thus they had few consequences for thepatients. This demonstrates that careful follow-up is essentialafter diuretic withdrawal. Our findings support the view thata large proportion of elderly patients on diuretics may notneed such treatment.     

Electrical Restitution and Conduction Intervals of Ventricular Premature Beats in Man: Influence of Heart Rate

Monophasic action potentials (MAP) were obtained from the outflow tract of the right ventricle during apical pacing in 20 patients with coronary artery disease. The electrical restitution was studied by interpolation of extrasystoles with various coupling intervals to the preceding steady-state beat at basic paced cycle lengths (CL) of 700, 600, and 500 msec. At higher frequencies the ventricular effective refractory periods (V-ERP) and duration of MAPs became shorter and the electrical restitution curves were displaced downwards (P less than 0.001). With increasing diastolic intervals preceding the extrasystole up to a maximum of 100 msec, the duration of premature MAPs increased at all frequencies. An obvious hump of the electrical restitution curve was observed at coupling intervals of 100 msec due to a later transient decrease (P less than 0.01) in duration of MAPs at the basic CL of 500 msec. No significant hump was observed at lower heart rates. Thus, a different time course of the electrical restitution was observed at various CLs. The intraventricular conduction intervals were shorter at the shorter basic CLs when compared to the 700 msec cycles (P less than 0.05). The conduction intervals were also modified by the coupling interval between the interpolated stimulus and the preceding steady-state action potential (AP). The premature beats elicited 30 msec or earlier after refractoriness were conducted more slowly at all basic cycle lengths (P less than 0.005), and those between 60 and 150 msec after the V-ERP more rapidly (P less than 0.01) than the steady-state beats. These observations have implications for the protocols used for introducing two or more frequencies during programmed stimulation in man. Furthermore, the conduction pattern in vivo cannot be interpreted from single cell studies.     

Region-Specific Expression of Immunoregulatory Proteins on Microglia in the Healthy CNS

与中枢神经系统的空间结构高度一致,大部分的中枢神经系统疾病表现为区域性分布。虽然小胶质细胞已被公认在各种中枢神经系统疾病中发挥重要的作用,但是小胶质细胞是否表现为区域特异性目前还不清楚。因此,本研究目的是评估在健康成年小鼠的中枢神经系统的不同区域中小胶质细胞的不同表型。运用体外流式细胞仪分析CD11b,CD40,CD45,CD80,CD86,F4/80,TREM-2b,MHCII,CXCR3,CCR9以及CCR7的表面表达。这些免疫调节标记物大部分均存在于小胶质细胞上并且在表达水平上有明显的区域特异性差异。这些发现在很大程度上证实了在健康成年小鼠中枢神经系统的小胶质细胞中存在着免疫多样性。     

An in vivo method for microhardness measurements on human teeth

A non-destructive, in vivo method of measuring the enamel hardness directly on patients is described. Normal values on 39 students arc given and compared with those of five patients, one of whom suffered from abnormal oral acid concentration, and the others from the effects of various degrees of hyposialosis caused by radiologic treatment of tumors in head and neck. The difference between the two groups was significant below the 0.1% level. It was suggested that the method may be used to test the degree of salivary gland inactivation after radiologic treatment and the efficiency of different saliva substitutes used to alleviate the effects of hyposialosis.     

Measurement of local blood flow in acute myocardial infarction: loss of 15-^m microspheres during the first hour

Distribution of radiolabeled microspheres is widely utilized for determination of regional blood flow in experimental myocardial infarction studies. The purpose of this investigation was evaluation of the microsphere method during 1 h of regional ischaemia. Special attention was focused upon loss of preocclusion microspheres from ischaemic myocardium; mechanisms for loss and blood flow distribution in non-ischaemic left ventricle. Microspheres (15 μm) were injected into the left atrium in nine pentobarbital anaesthetized cats prior to coronary artery occlusion and again after 1 h of occlusion. Preocclusion blood flow estimates were lower in ischaemic compared with non-ischaemic myocardium (1.36 us. 1.62 cm³min^-1 g^-1, P = 0.002), corresponding to 16%apparent loss. In endocardial ischaemic tissue, development of oedema could account for the loss. In epicardial ischaemic tissue, oedema was not present and loss was therefore due to migration of microspheres. Epicardial loss increased in proportion to restoration of left ventricular contractility. There was no evidence for significant microsphere loss through lymphatic pathways. In non-ischaemic left ventricular tissue, myocardial blood flow was evenly distributed from apex to base, and also between endocardial and epicardial layers. This study quantitates an important limitation to measurements of local blood flow in ischaemic myocardium by radiolabelled microspheres.     

Soluble Tumor Necrosis Factor Receptor in Serum and Urine Throughout Normal Pregnancy and at Delivery

PROBLEM : To determine the concentration of the two soluble tumor necrosis factor receptors (sTNFR), sp55 and sp75, in healthy pregnant women. METHOD : Serum and urine samples were longitudinally collected from a group of pregnant women (N=53) five times throughout pregnancy. Maternal and umbilical sera were obtained from some of the deliveries (N=31). The samples were analysed using ELISA based on two monoclonal antibodies (IV4E and 3H5) against the soluble tumor necrosis factor receptors (sp55 and sp75). RESULTS : Serum concentration of sp55 and sp75 were increased in pregnant women compared to that of nonpregnant controls. Concentration of both sTNFRs increased towards term. Labor was associated with further increase of sp55. Concentrations of sp55 and sp75 in umbilical serum were significantly higher than those of maternal serum. Significant correlations were observed between maternal and umbilical sTNFR concentrations. CONCLUSIONS : The current study suggests that pregnancy is associated with an activation of mechanisms regulating the biological activities of TNF.