Association of ureteropelvic pseudo-obstruction with cryptorchidism

A variety of upper urinary tract anomalies have been described in cryptorchidism. This report is of an asymptomatic patient with cryptorchidism, who appeared to have bilateral ureteropelvic-junction obstruction on excretory urography. Further investigations, including urodynamic studies and glomerular- and tubular-function tests, revealed no abnormalities. Ureteropelvic pseudo-obstruction can, therefore, be added to the list of numerous renal and urinary tract anomalies known to be associated with cryptorchidism.     

Effect of dimethylthiourea on paraquat toxicity in rats

We evaluated the utility of dimethylthiourea ( DMTU ), a hydroxyl radical scavenger, as potential therapy for paraquat poisoning. Seventy-five male Sprague-Dawley rats were divided into four groups ( DMTU -paraquat, paraquat, DMTU , control) and studied for up to 10 days. Clinical observations (dyspnea, weakness), mortality, hepatic and renal function tests, body weights, and histologic studies were performed. There was no mortality in the DMTU and control groups although various histologic and biochemical studies suggested that DMTU may be both hepatotoxic and nephrotoxic. In contrast, 74% of DMTU -paraquat rats and 39% of paraquat rats died (p less than 0.01). In addition, toxicity was clearly earlier in the DMTU -paraquat group than in the paraquat group. Hence, rather than being protective, treatment with dimethylthiourea was associated with increased mortality in paraquat-poisoned rats.     

Increased levels of protein C activity, protein C concentration, total and free protein S in nephrotic syndrome

Plasma protein C (PC) antigen concentration has been shown to be normal or increased in patients with proteinuria. However, the available data concerning PC anticoagulant activity in nephrotic syndrome (NS) are limited. We measured plasma PC antigen concentration. PC anticoagulant activity, total and free protein (PS) concentrations, and antithrombin III (AT-III) antigen concentration in 21 adult patients with NS. The results were compared with those obtained in a control group of normal volunteers. PC antigen concentration and its anticoagulant activity were significantly increased in the NS group when compared with the normal control group. Likewise, plasma total and free PS values were significantly higher in the NS patients than the corresponding values found in the control group. In contrast, plasma AT-III antigen concentration was significantly reduced in patients with NS. A negative correlation was found between plasma PC and AT-III levels. These observations suggest that increased plasma PC concentration and anticoagulant activity in NS may afford some protection against the thrombotic diathesis associated with antithrombin deficiency and other coagulation abnormalities in this otherwise hypercoagulable state.     

Lack of a Fast-Acting Effect of Erythropoietin on Arterial Blood Pressure and Endothelin Level

Abstract: Recombinant erythropoietin (EPO) has been shown to induce vascular smooth muscle contraction in vitro suggesting a rapid acting pressor effect. In addition its chronic administration has been shown to raise plasma endothelin. This study was designed to explore the presence, if any, of fast-acting effects of EPO on the arterial blood pressure and endothelin level in vivo. Nine stable patients with end-stage renal disease (ESRD) were included in a double-blind, crossover, placebo-controlled study using IV bolus injections of either EPO or saline solution administered to patients while they were comfortably seated in reclining chairs and undisturbed in individual climate-controlled rooms. After a 15-min resting period, the bolus injection was given, and blood pressure (BP) and heart rate were measured and recorded automatically every 5 min for 60 min using an electronic device to avoid operator bias/error. In addition, blood samples were obtained for plasma endothelin determination at time 0 and at 5, 30, and 60 min after injection. Patients were studied approximately 2 h before their regularly scheduled dialysis session. The EPO dosage given (50–60 U/kg) was equal to the maintenance dose, routinely administered during dialysis. No significant change was observed in arterial BP, heart rate, or plasma endothelin concentration relative to the baseline values after either EPO or placebo administration. Thus, the results have excluded a rapid effect on BP, heart rate, and endothelin concentration of EPO at therapeutic doses which, when chronically administered, can clearly raise arterial blood pressure in ESRD patients.     

Intrinsic Coagulation Pathway in End-Stage Renal Disease Associated with Spinal Cord Injury Treated with Hemodialysis

Plasma procoagulant activities of factors XII, XI, IX, and VIII and plasma concentrations of factor XII antigen and high molecular weight kininogen (HMK) were determined in nine men with chronic renal failure (CRF) associated with long-standing spinal cord injury (SCI) treated with hemodialysis. The results were compared with those obtained in a group of 10 ambulatory CRF patients and 8 normal volunteers (control group). Congenitally deficient plasmas were used as the substrate for the measurement of procoagulant activities in a one-stage clotting assay. Monospecific antibodies were employed in the measurement of factor XII antigen and HMK using gradient plate immunodiffusion and rocket immunoelectrophoresis. Factor XII coagulant activity and antigen concentration were significantly increased in the SCI group. The mean values for plasma factor XI and IX activities in the SCI group were comparable with those observed in the ambulatory patients and normal control group. However, marked variations in factor XI and IX levels were noted among the SCI patients with a few instances of mild to moderate factor deficiencies and several cases of markedly elevated levels. Factor VIII activity was markedly increased, with only two of the nine patients exhibiting normal values. HMK concentration in the SCI group was comparable with values obtained for the other groups. Following dialysis, factor XII antigen concentration rose and factor XI activity fell slightly but significantly. The results indicate that the combination of CRF and long-standing SCI is associated with marked aberrations of intrinsic coagulation pathway. The underlying mechanisms and the clinical consequences of these abnormalities are not known and require further investigation.     

Intravenous digital subtraction angiography (DSA) of hemodialysis access fistulae

Hemodialysis access fistulae or grafts are subject to a variety of complications, including thrombosis, stenoses, and aneurysm or pseudoaneurysm formation. The usual radiologic methods to evaluate these problems consist of retrograde venous angiography or standard femoral or brachial arteriography. Both are invasive, and may traumatize the artery or graft. Six patients with internal blood access were studied using digital subtraction angiography; five using a central venous injection and one with direct graft injection. Preliminary results indicate that intravenous digital subtraction angiography (IV-DSA) can depict the anatomy of access fistula with adequate spatial resolution. Pathologic entities (stenoses, aneurysms) can be demonstrated, as well as other findings of uncertain clinical significance (kinks and webs). In addition, hemodynamic data can be inferred from the near-physiologic sequence of vessel opacification. Methods are in development that will allow determination of absolute blood flow in pertinent vessels via IV-DSA. There were no complications in this small series, and all examinations were performed on outpatients utilizing standard technique.     

Topical thrombin and control of bleeding from the fistula puncture sites in dialyzed patients

The length of bleeding from the puncture sites of internal arteriovenous channels was markedly reduced with the use of topical thrombin in 12 patients treated with hemodialysis. This procedure can, therefore, save patient and staff time, minimize recurrent blood loss with each dialysis, and prolong the life of vascular access by diminishing the length of potentially hazardous compression needed for proper hemostasis.     

CT-guided laser therapy in resistant human tumors: phase I clinical trials

Photodynamic therapy was performed on ten tumors in patients who did not respond to initial therapy and for whom no additional conventional therapy was available. A sensitizing agent (hematoporphyrin derivative [HpD]) was injected directly into each tumor under computed tomographic (CT) guidance to deliver high concentrations to the tumor and to minimize systemic toxicity. Three to 6 days after the injection, a clear Teflon sheath catheter was placed into the tumor under CT guidance. The tumor was exposed to red light (630-nm wavelength) through laser fiberoptics inserted in the sheath. The initial investigation confirmed the technical feasibility of CT-guided photodynamic therapy by means of intratumoral HpD injections and laser exposure through fiberoptics inserted in sheath catheters. The toxicity from a single treatment was minor, and the tumor response was encouraging.     

Cimetidine in the management of metabolic alkalosis induced by nasogastric drainage.

Metabolic alkalosis resulting from nasogastric drainage is a well recognized and potentially serious clinical problem. In the postoperative patient with acute renal failure, the management of the metabolic alkalosis is particularly difficult, and established modalities of therapy are sometimes ineffective and can be hazardous to the patient. In this article, we report on the successful use of cimetidine (an H2-receptor antagonist) as an adjunct in the treatment of severe metabolic alkalosis in a postsurgical renal failure patient. To our knowledge, this is the first reported successful use of cimetidine in the treatment of metabolic alkalosis due to gastric acid loss.