Robinow syndrome: Report of two cases and review of the literature

We report two patients with Robinow syndrome, review the published literature and stress the importance and limitations of radiographic examination in the diagnosis of this disorder, which shows extreme clinical and radiographic variability. The radiographic differential diagnosis of Robinow syndrome is discussed.     

The effect of prior leaning on human postural responses

This study examines how human postural responses are altered by leaning about the ankles to five different initial stance positions prior to anterior or posterior horizontal translations of the support surface. When subjects leaned in the same direction as the translation-induced sway, postural strategies changed to use of less ankle torque and more horizontal shear forces at the surface to return to equilibrium. This change in strategy was associated with reduced and delayed activation of the stretched ankle muscles and an increased activation of proximal muscles producing rapid hip flexions or extensions. The changes in ankle muscle activation strength and latencies cannot be predicted based on simple stretch or load reflexes, but match predictions from computational, biomechanical models of human stance co-ordination^1–4.     

输血传播西尼罗病毒

西尼罗病毒(WNV)属黄病毒科黄热病毒属。黄热病毒属的其它成员包括登革热病毒、扁虱热传播性脑炎、黄热病,日本脑炎和圣·路易斯大脑炎病毒。1937年Smithburn及其同事首先从白尼罗河源头乌干达北部的西尼罗河地区一例37岁妇女的血液中分离出WNV,按照当时的情况,新分离的虫媒病毒的命名以获得该病毒的地理名称命名。耶例妇女参与了昏睡病监视项目,并且在抽血的当天有38.1℃的发热,分离出的病毒在恒河猴大脑内和鼻内接种以后导致发热和脑炎(但是当给予静脉注射时只有发烧)以及诱导了免疫。非洲绿猴脑内接种该病毒没有使其患上脑炎,仅有发热,感染该病毒后做鼠生物实验,发现3只恒河猴中有2只血液中含有该病毒达9天。     

Role of free protein S and C4b binding protein in regulating the coagulant response to Escherichia coli

Previous studies showed that infusion of C4b-binding protein with sublethal Escherichia coli (E. coli) in the primate produced a consumptive coagulopathy followed by microvascular thrombosis and renal failure. The first objective of this study was to characterize the pathophysiology and mechanism of this phenomena following infusion of both these agents with emphasis on defining the role of free protein S. The second objective was to examine the relevance of this model to the hemolytic uremic syndrome. Infusion of C4b-binding protein alone reduced free protein S and decreased platelet concentration to 20% of baseline, whereas infusion of the C4b-binding protein/protein S complex did not. There was no activation of other inflammatory or coagulant factors. Infusion of sublethal E coli alone produced a transient inflammatory response with no reduction of free protein S. However, coinfusion of C4b-binding protein with sublethal E coli reduced free protein S and produced a thrombocytopenia, anemia, and a microvascular thrombotic response, whereas infusion of the C4b-binding protein/protein S complex with sublethal E coli did not. Studies comparing the effects of neutralizing (S-163) and nonneutralizing (S- 145) antibodies with protein S coinfused with sublethal E coli produced similar contrasting results. Therefore, we concluded that neutralization of free protein S, and not some other property of C4b- binding protein influenced by protein S, accounted for this microvascular thrombotic response. This response is similar to the hemolytic uremic syndrome characterized by thrombocytopenia, anemia, shistocytosis, and renal glomerular thrombosis with uremia. Comparison of the respective renal histopathologic appearance supports this conclusion. This raises the possibility that inhibition of protein S activity (possibly by one of the forms of C4b-binding proteins) might be one of the factors contributing to microvascular thrombotic disorder, such as the hemolytic uremic syndrome.     

Renal allograft rejection: evaluation by Doppler US and MR imaging

A prospective study compared the efficacy of Doppler ultrasonography (US) and magnetic resonance (MR) imaging in evaluating 38 renal allografts, with specific attention to transplant rejection. Forty-three Doppler US and 42 MR examinations were performed and interpreted. Histologic correlation was obtained from 22 biopsy or nephrectomy specimens. Clinical correlation or a response to instituted therapy was used as confirmation in the remaining allografts. Accuracy in identifying cyclosporine toxicity or acute tubular necrosis could not be evaluated because there were few such cases, with concomitant rejection in most. The ability to predict and identify presence or absence of rejection was not affected by different serum creatinine values. Doppler US was significantly superior to MR imaging in identifying allograft rejection, demonstrating a higher sensitivity (95% vs. 70%), specificity (95% vs. 73%), and accuracy (95% vs. 71%). Because of its low cost and accessibility, Doppler US should become the primary modality for renal transplant screening.     

Follow-up studies of multicystic dysplastic kidneys

Thirty cases of multicystic dysplastic kidney (MCDK) were diagnosed over 11 years. Nine patients underwent nephrectomy: three for increasing kidney size (classic MCDK) and six because of an inconclusive diagnosis (hydronephrotic MCDK). Of the remaining 21 patients, 19 were followed up for a mean of 33.5 months (range, 2-101 months). Follow-up ultrasound examinations revealed that 16 kidneys did not change in size, one decreased in size after cyst puncture, and two disappeared (one after cyst puncture). This series included one case of non-renin-producing hypertension that was controlled medically, one case of nephroblastomatosis found in the removed dysplastic kidney, and one case of pyelonephritis in the contralateral kidney. When the diagnosis of classic MCDK is made with imaging modalities, the lesion may not have to be removed unless there is growth of the mass during the 1st year of life. Nine percent of these lesions will disappear within the first 3 years of follow-up, and the authors recommend an even longer period of follow-up.