Management of ascites in cirrhosis

Ascites is one of the earliest and most common complications of patients with cirrhosis. A typical circulatory dysfunction characterized by arterial vasodilation, high cardiac output and stimulation of vasoactive systems is commonly present in these patients and is associated with a poor prognosis. The treatment of ascites has been based on the combination of a low-sodium diet and the administration of diuretics. The reintroduction of paracentesis and the recent introduction of the transjugular intrahepatic portosystemic shunt (TIPS) are the most relevant innovations in the treatment of ascites during the past two decades, although controlled trials in large series of patients are needed to delineate whether TIPS is a safe and useful treatment for these patients.     

Cholesterol atheromatous embolism: an increasingly recognized cause of acute renal failure

BACKGROUND.: Cholesterol atheromatous embolism is a systemic disease resultingfrom cholesterol crystal embolization to many organs, includingthe kidney. Vascular surgery, vascular radiology investigationsand anticoagulation have been identified as inciting factors. METHODS.: Fifteen patients with extensive atherosclerosis, presentingwith simultaneous occurrence of acute renal failure and peripheralischaemic changes were diagnosed as having acute renal failuredue to cholesterol atheromatous embolism. RESULTS.: The patients, 12 men and three women, had an average age of65 years. In one patient, spontaneous occurrence of the diseasewas observed. An inciting factor was identified in 14 patients:aortography in 10, aortic surgery in two, and thrombolysis intwo. Clinical course of acute renal failure was quite variable.Four patients required dialysis; 11 were conservatively managed.All patients had concomitant skin lesions, including digitalmottling, cyanosis and gangrene of the toes, and livedo reticularisof the lower limb and abdomen. Eosinophilia was the most commonlaboratory abnormality. The diagnosis of cholesterol atheromatousembolism was confirmed by tissue examination in eight; in threeit was based on the finding of retinal cholesterol emboli; infourpatients it was made on clinical grounds. Seven patientsdied within 36 months. Death was most commonly from cardiaccauses. CONCLUSIONS.: Since the population at risk for cholesterol embolism is growingand the disease is iatrogenic in origin, we should expect todetect cholesterol embolism with greater frequency as causeof acute renal failure in the future.     

显微锁孔手术治疗脑干及其周围病变

目的 将显微锁孔手术应用于脑干及其周围病变的外科治疗，探求以最小的创伤来取得最佳的手术疗效。方法 采用颞下锁孔人路、乳突后锁孔人路、枕下正中锁孔人路，以20mm左右直径的骨窗进行脑干及其周围病变的显微手术治疗。结果 本组16例例病人术后3d内均行MRI或DSA检查，肿瘤或动静脉畸形全切除11例，次全切除3例，部分切除1例，1例小脑后下动脉瘤成功夹闭。术中输血3例。并发脑脊液耳漏1例，硬膜下积液1例，1例术后持续昏迷40d苏醒，无死亡及感染病例。结论 锁孔人路微创技术处理脑干及其周围病变，因其手术创伤小，疗效佳，费用节省，值得临床推广应用。     

Reversible low-molecular-weight proteinuria in patients with distal renal tubular acidosis

Four patients with untreated renal tubular acidosis had a urinary excretion of low-molecular-weight (LMW) proteins which was restored to normal by alkali therapy. Hypokalaemic proximal tubular damage in untreated patients with distal renal tubular acidosis is believed to be the cause of LMW proteinuria. An examination of urinary excretion of LMW proteins is useful for determining hypokalaemic proximal tubular dysfunction, as well as the efficiency of alkali therapy.     

Disposition Characteristics of Macromolecules in Tumor-Bearing Mice

As part of the strategy for the design of macromolecular carriers for drug targeting, the disposition characteristics of macromolecules were studied in mice bearing tumors that served as target tissues. Eight kinds of macromolecules including four polysaccharides and four proteins with different molecular weights and electric charges were used; tissue distribution and tumor localization after intravenous injection were studied. Pharmacokinetic analysis revealed that the tissue radioactivity uptake rate index calculated in terms of clearance was different among the tested compounds; especially, the urinary radioactivity excretion clearances and the total hepatic radioactivity uptake clearances varied widely. Compounds with low molecular weights (approximately 10 kD) or positive charges showed lower tumor radioactivity accumulation; radioactivity was rapidly eliminated from the plasma via rapid urinary excretion or extensive hepatic uptake, respectively. On the other hand, large and negatively charged compounds, carboxymethyl dextran, bovine serum albumin, and mouse immunoglobulin G, showed higher radioactivity accumulation in the tumor (calculated total amounts were 15.6, 10.8, and 20.8% of the dose, respectively) and prolonged retention in the circulation. These results demonstrated that the total systemic exposure rather than the uptake rate index was correlated with total tumor uptake. Molecular weight and electric charge of the macromolecules significantly affected their disposition characteristics and, consequently, determined radioactivity accumulation in the tumor. It was concluded that a drug–carrier complex designed for systemic tumor targeting should be polyanionic in nature and larger than 70,000 in molecular weight.     

Subclinical pulmonary oedema and intermittent haemodialysis

It has been postulated that patients with chronic renal failure,even in the absence of cardiopulmonary symptoms, accumulateinterstitial pulmonary fluid, which is removed by haemodialysis.To test this hypothesis we used the indocyanine green (ICG)-heavywater double indicator dilution method to measure lung water,cardiac output, and central blood volume in relation to haemodialysis.Ten uraemic patients, without cardiopulmonary symptoms, wereinvestigated at the beginning and end, and 2 h after, a regulardialysis session. A group of 18 surgical patients about to undergoelective abdominal surgery served as controls. Despite normalgas exchange, central blood volume, and cardiac output at thestart of dialysis the mean (SD) lung water was significantlyhigher than in the control group [4.8 (0.9) compared with 3.6(0.7) ml/kg, P<0.001]. There was no correlation between weightgain between sessions of dialysis and the magnitude of lungwater at the start of dialysis. Lung water decreased (P <0.001)to the level of the control group in response to dialysis. Therewas no correlation between weight loss and reduction in lungwater induced by dialysis. In conclusion, we have verified thepresence of subclinical pulmonary oedema which was removed bydialysis in a group of patients with established renal failure.The variations in lung water cannot be explained by hydrostaticmechanisms alone.     

急性肾功能衰竭的治疗进展

目的：探讨急性肾功能衰竭的治疗。方法：复习有关急性肾功能衰竭的治疗文献，作一总结。结果：使用人工合成三肽序列（RGD）的多肽、生长因子、心房利钠因子和人工肾小管治疗急性肾功能衰竭都取得了较好的疗效。结论：这些新的治疗可望改善急性肾衰的预后和降低死亡率。     

Presynaptic α2-adrenoceptor-mediated modulation of norepinephrine release from vascular adrenergic neurons in reduced renal mass salt hypertensive rats

The present study was designed to investigate the presynaptic alpha 2-adrenoceptor function to inhibit norepinephrine (NE) release in blood vessels of reduced renal mass salt hypertensive rats (Na-loaded HT). Isolated perfused mesenteric vasculatures were prepared from Na-loaded HT and normotensive control rats (NT-control), and the NE release and vascular responsiveness were examined. Periarterial nerve stimulation caused a significantly greater release of NE and pressor responses in Na-loaded HT than in NT-control. Yohimbine, a potent alpha 2-adrenoceptor antagonist, demonstrated the facilitatory effects on NE release during nerve stimulation. The effects were significantly attenuated in Na-loaded HT compared with NT-control. These results demonstrate that vascular sympathetic nervous activity might be enhanced in Na-loaded HT. Furthermore, the increased NE release from vascular adrenergic neurons in Na-loaded HT could partially depend on impaired presynaptic alpha 2-adrenoceptor-mediated modulation, which might contribute to the pathogenesis and maintenance of this form of salt-dependent hypertension.