The reflex effect of changes in renal perfusion on hindlimb vascular resistance in anaesthetized rabbits

This study was designed to characterise the response of the hindlimb vasculature to reduced renal perfusion in the anaesthetized rabbit and to elucidate whether the stimulus was dependent upon reduced renal perfusion pressure (RPP) or blood flow (RBF). Acute decreases in renal perfusion resulted in rapid and reversible increases in femoral perfusion (FPP). This vascular response was completely abolished following renal denervation indicating that the afferent component of the reflex is neurally mediated. Acute hindlimb responses to changes in renal perfusion pressure were present whether the limb was perfused with homologous blood or cross-perfused with blood from a donor rabbit, demonstrating that the efferent component of the response is also neurally mediated. There was a 28-s latency for initiation of the hindlimb vasoconstriction, which is consistent with recent evidence for renal autocoid stimulation of the afferent renal nerve receptors. Decreasing RPP indirectly, by altering flow, resulted in a hindlimb vasoconstriction below approximately 55 mm Hg (7.3 kPa) RPP or 15 ml/ min RBF. However, decreasing RPP by directly reducing pressure in graded steps resulted in increases in FPP, which reflected the changes in renal flow; thus during the autoregulatory phase, where flow did not change as pressure fell, FPP also remained stable. The results of these protocols suggest that a neurally mediated hindlimb vascular reflex is stimulated by decreased renal flow rather than pressure.     

Urodilatin: a new peptide with beneficial effects in the postoperative therapy of cardiac transplant recipients

Summary Renal failure after heart transplantation (HTx) still remains a serious problem, especially when cyclosporin A is used for immunosuppression in the early postoperative therapy. To preserve good renal function without reducing immunosuppressive cyclosporin A treatment, we administered urodilatin (CDD/ANP-95-126) in a long-term, low-dose infusion in addition to the usual medication after heart transplantation. From November 1990 to June 1991, 51 patients (46 male and 5 female; mean age 48 years) were treated with a 620 ng/kg bw·min infusion for 96 h after HTx. The renal function and hemodynamic parameters of these urodilatin-treated patients were compared in this sequential study with 40 patients (33 male and 7 female; mean age 49 years) who had undergone HTx previously from May to November, 1990, as controls. In this phase IIa study, both groups did not differ significantly with respect to age, sex, indication for HTx, and preoperative renal function. In comparison with controls patients treated with urodilatin had a significantly better renal function: a reduction in the peak plasma creatinine (PC values day 4 : 1.5 ± 0.11 vs. 2.19 ± 0.19 mg/dl; P = 0.002), a lower peak serum urea (SU values day 4 : 109 ± 8 vs. 154.7 ± 8.94 mg/dl ; P = 0.0036), and a lower incidence of hemodialysis (6% vs. 10%) were observed. Adequate diuresis was maintained in spite of the reduction of furosemide by more than 60% (P = 0.005) on each day of urodilatin infusion in comparison with controls. The mean central venous pressure was significantly lower by about 50% (P = 0.02) during the administration of urodilatin in spite of reduced vasodilator medication with nitroglycerin. From this phase IIa study, we may conclude that urodilatin could be an important drug in intensive care treatment. For patients undergoing HTx, this peptide seems to be indicated for the improvement of renal function and cardiovascular status, especially in postoperative therapy using high-dose cyclosporin A treatment.Abbreviations ACE angiotensin converting enzyme - ANP atrial natriuretic polypeptide - ATG antithymocyte globulin - bpm beats per minute - bw body weight - CDD cardiodilatin - CDD/ANP-99-126 circulating form of vasorelaxant cardiac peptide - CHD coronary heart disease - CyA cyclosporin A - DCM dilated cardiomyopathy - GLM general linear model - hANP human atrial natriuretic polypeptide - HTx heart transplantation - NTG nitroglycerine - PC plasma creatinine - SU serum urea - SAS statistical analysing system     

The response of heat shock proteins 25 and 72 to ischaemia in different kidney zones

 Induction of heat shock proteins (HSPs) following cell injury contributes to the protection of vital cell functions. It was, therefore, of interest to study the effects of transient renal ischaemia on the abundance and distribution of two HSPs, HSP25 and HSP72, in renal tissue using Western-blot techniques. Analyses were performed on the supernatant (HSP25, HSP72) and pellet (HSP25) of homogenates obtained from cortex (CX) and outer (OM) and inner (IM) medulla of the rat kidney immediately after 60 min of ischaemia followed by varying periods of reperfusion. Ischaemia of the left kidney caused HSP25 contents to decrease in CX, OM and IM by 73, 89 and 54% respectively, compared with the corresponding zones of the contralateral control kidney. This initial decrease in supernatant HSP25 was accompanied by an increased abundance of HSP25 in the pellet. Following reperfusion, HSP25 contents in the supernatant gradually increased in CX and OM, reaching, after 24 h, values that were 5.4- and 2.5-fold higher, respectively, than those in the control kidneys. After 7 or 14 days of reperfusion, HSP25 contents had not completely normalised in CX, but had reached control levels in OM. In IM, the HSP25 content remained below control throughout the entire reperfusion period. HSP72 (supernatant) was below the detection limit in the CX of the control kidney. Similar to the level of HSP25, that of HSP72 was also markedly lower in OM and IM immediately after ischaemia. The intrarenal distribution of HSP72 and the sequence of zonal changes in HSP72 contents were similar to those observed for HSP25. These results are compatible with the view that, during ischaemia and the initial reperfusion period, HSP25 migrates from the cytoplasmic compartment (supernatant) into the nucleus and/or associates with cytoskeletal structures. The observation that both HSP25 and HSP72 are transiently induced in CX and OM, but not in IM, may be explained by the fact that, while all kidney cells are exposed to ischaemic stress, only inner medullary cells experience a major postischaemic attenuation of osmotic stress. Received: 11 February 1997 / Received after revision and accepted: 26 March 1997     

Ultrastructural study of the ciliated cells from renal tubular epithelium in acute progressive glomerulonephritis

Light microscopic examination of the renal tubular epithelium of a female with a rapid progressive glomerulonephritis revealed in several areas the presence of cells bearing ciliumlike structures.

At transmission electron microscopy, normal tubular cells appeared to be partially replaced by epithelial cells showing numerous 9×2 cilia and a normally developed basal apparatus. The cilia showed several ultra-structural details (i.e., outer dynein arms, spokes) such as observed in kinocilia of the respiratory epithelium. In addition, a number of poorly differentiated cells showing cilia with a 9 + 0 pattern and at the same time cilia with a 9 + 2 pattern of microtubular arrangement were also seen.

The possible biologic significance of these cilia is discussed.     

Acute renal failure in diabetics

Conclusions Acute renal failure in diabetic patients occurs, as a result of certain specific conditions. The most common of these are hyperglycaemic hyperosmolar coma, diabetic ketoacidosis, the use of radiocontrast media, and renal papillary necrosis. The management of diabetics with acute renal failure is essentially the same as for non-diabetic patients but may be complicated by the problems of metabolic control, vascular access, and vascular instability. Prevention is important as the development of acute renal failure adds considerably to the morbidity and mortality of these conditions and is often avoidable.Wellcome Research Fellow     

Tula Virus as Causative Agent of Hantavirus Disease in Immunocompetent Person,Germany

We report molecular evidence of Tula virus infection in an immunocompetent patient from Germany who had typical signs of hantavirus disease. Accumulating evidence indicates that Tula virus infection, although often considered nonpathogenic, represents a threat to human health.     

肾综合症出血热血清蛋白与肝肾功能及临床关系的研究

目的 了解肾综合症出血热（HFRS）各期血清蛋白的变化特点及其与肝、肾功能的关系。方法 采用瑞士产COBAS MIRA PLUS CC全血动生化分析仪及日本产MA－4210尿液分析仪分别检测同时的空腹静脉血及晨尿。结果 150例HFRS患者217次检测血清总蛋白（T）平均为63.51g/L,白蛋白（A）为36.29g/L,球蛋白（G）为27.22g/L,A/G=1.33。其中A／G为1.49-1.0者137例（63.3%）,A／G＜1.0者27例（12.44%）,A／G≥1.5者53例（24.42%）。结论 HFRS患者有75.58%存在着低白蛋白血症,并贯穿于各期,异常程度与病情轻重呈正相关,主要原因是肾脏损害,大量白蛋白从尿中丢失,与肝脏的合成功能关系不大。     

肾综合征出血热多尿期肾图的变化及意义

目的 :研究肾综合征出血热 (HFRS)多尿期肾图的变化及其意义。方法 :静脉注射 1 31 I-邻碘马尿酸钠 (1 31 I- OIH) 3.7×10 9Bq(10 μCi) ,用闪烁照相法描记 15 min,通过电子计算机自动处理 ,得出肾图的各项参数。结果 :2 0例受检者均已进入多尿期 ,2 4h尿量在 2 0 0 0 ml以上 ,血尿素氮 (BUN)已正常或接近正常 ,但肾图却明显异常 ,表现为半排时间 (TC1 /2 )延长 (>8min) ,15min残留率 (C1 5 /b)超过 5 0 % ,肾脏指数大多低于 45 % ;同期作尿β2 -微球蛋白 (β2 - m )测定 ,也明显高于正常 ;8例作发射型电子计算机扫描 (ECT)检查 ,肾小球滤过率 (GFR)和有效肾血浆流量 (ERPF)分别为 (4 0 .8± 2 1.2 ) ml/min和 (35 0 .8± 10 2 .1) ml/min,均明显低于正常 (P<0 .0 1)。结论 :HFRS患者多尿期肾图大多呈排出不良和功能受损的图形 ,表明该期肾功能以及肾血流量尚未恢复正常 ,对症治疗仍需继续。     

超声引导下肾囊肿的治疗

目的：通过超声的引导,对肾囊肿采取精确定位穿刺治疗,从而使肾囊肿的治疗更为简便有效。方法：从1995年以来的肾囊肿患者中选取12例单纯性肾囊肿患者,在穿刺探头引导下,对肾囊肿进行穿刺注射无水乙醇治疗,并在术后3－12个月进行随访。结果：治疗后3个月治愈率41．7％,6个月66．7％,12个月治愈率83．3％,有效率100％,无并发症发生,结论：超声引导穿刺治疗肾囊肿方法简便,安全可靠,痛苦小,治愈率高,值得向广大基层医院推广。