溴莫尼定对视网膜缺血性损伤神经保护作用的实验研究

目的：探讨溴莫尼定(brimonidine)对视网膜缺血性损伤神经的保护作用。方法：新西兰大耳白兔32只，随机分为正常对照组、生理盐水治疗组、噻吗心安(timolol)治疗组、brimonidine治疗组，每组8只。后3组为损伤治疗组，通过生理盐水前房高压灌注的方法，制成视网膜缺血动物模型，在视网膜缺血前lh其结膜囊内分剐给予生理盐水、0．5％timolol眼液或0．2％brimonidine眼液局部治疗。在灌注后7d，观察图形视网膜电图(P-ERG)b波振幅变化，并进行组织形态学观察和视网膜神经节细胞(RGC)计数分析。结果：灌注后7d，3个损伤治疗组相对b波振幅恢复率为：7％、11％和64％，RGC标准丢失率为：43％、38％和12％，brimori-die治疗组视网膜组织形态结构接近正常对照组，而生理盐水治疗组和timolol治疗组视网膜内层组织结构损伤明显。结论：Brimonidine局部治疗对缺血诱导的视网膜结构和功能的损害有明显的神经保护作用。     

Nutritional considerations in intravenous drug misusers: a review of the literature and current issues for dietitians

Poor nutritional status and inadequate dietary intake in intravenous drug misusers (IVDMs) is a well-recognized problem among those involved in their care. However, there are very few published studies to substantiate these observations. This paper provides a review of the current literature and outlines the aims of dietary advice for IVDMs.     

Orbital volume measurement in the management of pure blowout fractures of the orbital floor.

With the recent advent of accurate orbital volume assessment by computed tomography, a retrospective analysis was made of 31 patients with 'pure' blowout fracture of the orbital floor, managed either surgically or conservatively, to determine whether orbital volume measurement could provide an additional parameter of use in the management of such fractures. There was a significant difference in orbital volume discrepancy between patients managed surgically or conservatively suggesting that this investigation may be of use in decision making on surgical intervention in patients with orbital blowout fractures.     

Herpetic croup: two case reports and a review of the literature

Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup.     

Effect of intravenous ketanserin on the human action potential duration at fixed heart rate

Summary In this study any changes in action potential duration or Q-T interval due to acute doses of ketanserin were monitored. The effect of a bolus dose (10 or 20 mg) followed by an infusion (10 or 20 mg over 20 minutes) of ketanserin on the Q-T interval and action potential duration was studied in six patients undergoing routine cardiac catheterization. Action potential duration was measured with a silver-silver chloride electrode catheter while heart rate was kept constant by atrial pacing and reflex effects avoided by -adrenergic blockade. There were some prolongations of the action potential duration but they were not in excess of 40 msec and did not reach statistical significance (control 263±46.0 msec; bolus 269±52.1 msec; infusion 262±53.6 msec; nor were there any significant changes in Q-T interval. Thus acute intravenous doses of ketanserin, in the absence of hypokalaemia or other Q-T interval-prolonging drugs, have no consistent effect on Q-T interval or action potential duration; prolongation of the action potential, when it occurs, is small.     

Subjective profile of phenylpropanolamine: absence of stimulant or euphorigenic effects at recommended dose levels

A total of 837 healthy volunteers presenting with various degrees of obesity participated in a large-scale, double-blind, placebo-controlled evaluation of the subjective effects of phenylpropanolamine (PPA), with particular attention to measurement of the euphoriant or stimulant potential of therapeutic doses of the compound. Dosage forms studied were PPA 75 mg sustained release, PPA 25 mg, and placebo. Subjects were recruited from four independent clinical sites. At each site, subjects were stratified according to degree of overweight (normal, mildly overweight, moderately overweight, or severely overweight) and randomly assigned to one of the three drug treatment regimens. Subjective effects were measured 11 times during the 12-hour experimental session using a short-form version of the Addiction Research Center Inventory. Data analysis did not indicate discernible subjective effects that would differentiate PPA from placebo, but did show typical circadian fluctuations. These results provided evidence that therapeutic doses of PPA do not produce the euphoriant or "stimulant" subjective effects that characterize drugs of abuse.     

Antibodies in guinea-pigs immunized with kidney and lung basement membranes

The cross-reaction of antibodies to tubular basement membrane (TBM) with alveolar basement membrane (ABM) has been studied in guinea-pigs with tubulointerstitial (TI) nephritis. Forty-three of fifty-two Hartley guinea-pigs immunized with rabbit TBM in complete Freund's adjuvant developed TI nephritis. In addition to linear deposits of guinea-pig IgG and C3 in the TBM, thirty-two of the nephritic animals showed linear immune deposits in ABM; twelve of these animals had thickened alveolar septa and increased numbers of polymorphonuclear (PMN) leucocytes in lung tissue. Sera and eluates of kidney and lung from nephritic guinea-pigs reacted strongly with TBM and more weakly with ABM of normal animals. Absorption experiments suggested that antibodies to TBM and ABM were closely related or identical. Only a minority of guinea pigs immunized with TBM showed in vivo binding of IgG to glomerular basement membrane (GBM). Immunization of guinea-pigs with lung-homogenate-induced antibodies binding to TBM and ABM (in approximately 45% of animals) and to GBM (in approximately 30% of animals). Immunization with crude GBM-induced antibodies which reacted preferentially with TBM and ABM. In contrast, collagenase-treated GBM-induced antibodies preferentially reactive with GBM. TI nephritis was induced in both Strain 13 and Strain 2 guinea-pigs, but the nephropathy developed much faster in Strain 13 animals. Immunization with rabbit TBM-induced antibodies reactive with ABM in 25% of Strain 13 guinea-pigs and in 50% of Strain 2 guinea-pigs, respectively.     

Ramification of the portal vein at the porta hepatis in humans

The ramification of the portal vein at the porta hepatis was studied by anatomic dissection performed in 32 formalin fixed human livers. In all the specimens there were branches which ran towards the caudate lobe, arising from the portal vein and either from the left or the right portal branches. Tri-and quadrifurcation of the portal vein was observed. In 5 cases (16%) there were branches arising from left portal branch or portal vein and directed anteriorly to the quadrate lobe or to the region of the gall-bladder sulcus. These branches ranged from 1.0 to 6.0 mm in diameter. The portal caudate branches were divided into 3 groups.Group 1: Branches to the papillary process; 1 or 2 branches in 26 cases (82%), 3 or 5 branches in 3 cases (9%) and no branches in 3 cases (9%);     

IL-4 inhibits human CD8 T cell expression of the common IL-2 receptor gamma chain

Previous studies in both rats and humans have shown that interleukin (IL) 4 can suppress the generation of IL-2-producing CD8 T cells. In an attempt to elucidate the mechanism by which this suppression is brought about, we set out to investigate whether the IL-4 signal interferes with the IL-2 receptor system. It has already been reported that IL-2 can affect the expression of its own receptor and thus provide a means of controlling its own activities. In this study, we demonstrate that the IL-2 Ralpha- and the IL-2 Rgamma-chains are dramatically upregulated following stimulation of CD8 T cells, whereas lower levels of beta-chain are observed. IL-4 did not affect the expression of the alpha- or beta-chains, but was found to inhibit the generation of common gamma-chain-expressing cells. Moreover, CD4 T cells were found to express much lower levels of this subunit and appeared less sensitive to the effects of IL-4. We postulate that the differential expression of the gamma-chain subunit, in the presence and absence of IL-4, may provide a tool for identifying functionally distinct subpopulations of CD8 T cells.