Activity of the Na,K-ATPase α4 Isoform Is Regulated During Sperm Capacitation to Support Sperm Motility

The α4 polypeptide is a testis-specific isoform of the catalytic subunit of the Na,K-ATPase, which is essential for sperm motility and fertility. In the present study, we have investigated the regulation of activity of the α4 isoform and the relevance of this event for sperm capacitation. We have performed this by taking advantage of the selective high affinity of α4 for the inhibitor ouabain. Our results show that ouabain-sensitive hydrolysis of ATP and uptake of (86)Rb, corresponding to the enzymatic and ion transport activities of α4, respectively, increased during sperm capacitation in a time-dependent manner. Specific labeling of α4 with the fluorescent indicator bodipy-ouabain and immunoblot analysis of biotinylated and streptavidin-precipitated sperm plasma membrane proteins indicated a capacitation- and time-dependent rise in levels of active α4 isoform at the sperm surface. Ouabain inhibition of α4 blocked the increase in total sperm motility and the hyperactive motility pattern characteristic of sperm capacitation. Moreover, interference of α4 activity with ouabain partially prevented the intracellular decrease in Na(+) and the plasma membrane hyperpolarization that typically accompany sperm capacitation. In contrast, ouabain inhibition of α4 did not affect the spontaneous sperm acrosomal reaction following capacitation. Together, these results demonstrate that Na,K-ATPase α4 activity is up-regulated during sperm capacitation through mechanisms that involve both increases in molecular activity and levels of α4 at the sperm plasma membrane. This increase in α4 activity helps maintain the changes in motility that are associated with sperm capacitation, emphasizing the biologic relevance of the Na,K-ATPase α4 isoform in sustaining sperm function.     

First orthotopic liver transplantation in patient with biliary atresia and situs inversus in spain

Biliary atresia is the most common indication for liver transplantation in the pediatric age group. The Kasai portoenterostomy has become established as the primary treatment for biliary atresia. If portoenterostomy fails, death before 2 years of age is likely without liver transplantation. The most common multiple malformation syndrome associated with biliary atresia is polysplenia syndrome, which forms a constellation of defects of body symmetry, splenic development and vascular anomalies, including situs inversus, polysplenia and others. The situs inversus was formerly considered an absolute contraindication for liver transplantation. Recently however, several case reports have been published suggesting that neither situs inversus nor this particular subset of vascular abnormalities should be considered contraindications to liver transplantation. We present one case of liver transplantation performed in patient with biliary atresia, situs inversus and polysplenia. This is the first report described in Spain for a liver transplant in a child with biliary atresia plus situs inversus.     

Duplication of the male urethra

Duplication of the male urethra is an uncommon congenital malformation. The majority of cases are diagnosed during infancy, and are detected by observing two urethral meatus, or by the appearance of some form of complication, normally of an obstructive nature. Micturitional cystourethrography is an essential test, both in confirming diagnosis of this pathology, and in determining the type of urethral duplication. Excretory urography is also recommended due to its association with other possible urological and extra-urological congenital disorders. Treatment is based on the patient's clinical symptoms, with a waiting period considered advisable for asymptomatic cases. Here we present a case of incomplete urethral duplication, diagnosed from a bladder outlet obstruction, secondary to stenosis of the urethra, which was treated with an endoscopic urethrotomy and distal septotomy, obtaining excellent clinical results.     

Ureteral implantation in peritoneum. Exceptional complication in renal transplantation

Because of the extraperitoneal location, generally used for renal grafting, intraperitoneal urine leaks are a rare complication after transplantation. We report a patient on peritoneal dialysis who developed ascites, abdominal pain, anuria and shock suddenly after renal transplantation. The patient was immediately taken back to the operating room. An abnormal implantation of ureter into the peritoneum overlying the bladder when carrying out an unstented parallel incision extravesical ureterone-ocystostomy was identified. After correcting ureter implantation the patient had immediate diuresis, renal function rapidly improved, with no further complications. Contributing causes were poor exposure, thickened peritoneum secondary to recurrent peritonitis, and the presence of residual peritoneal dialysis fluid.     

Low calorie commercial sugar is a sensitive marker of glomerular filtration rate

BACKGROUND: Glomerular filtration rate (GFR) in humans and animals might be determined with precision by measuring the clearance of an ideal marker, such as inulin. However, the use of inutest, an inulin analog, is limited by its cost and accessibility. The present study tested whether low calorie commercial sugar (LC sugar) can be used to measure GFR during normal and renal dysfunction. METHODS: Two groups of 6 male Wistar rats weighing 300 to 350 g were included. One group was treated with a daily dose of cyclosporine (CsA) 30 mg/kg subcutaneously for 7 days and the other group was formed by nontreated control rats. In one half of each group, GFR was evaluated by using inutest and in the other half by using LC sugar. GFR was also evaluated by using a wide LC sugar plasma concentration range in an additional group. RESULTS: In nontreated rats, the mean GFR evaluated with LC sugar was 2.2 +/- 0.1 mL/min. This value is equal to that obtained with inutest: 2.3 +/- 0.1 mL/min. CsA administration produced a significant reduction of renal blood flow and renal function. The GFR reduction induced by CsA was similarly determined by both LC sugar and inutest to be at 1.0 +/- 0.2 and 1.1 +/- 0.2 mL/min (P= NS), respectively. In addition, GFR did not change when LC sugar plasma concentration gradually increased. CONCLUSION: Our results show that in both normal and pathophysiologic conditions, LC sugar is a good marker of GFR similar to the gold standard inutest.     

Clinical and familial study of arrhythmogenic right ventricular cardiomyopathy

Objective　To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). Methods　Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. Results　All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). Conclusion　Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle.     

111In-oxine platelet survivals in thrombocytopenic infants

Thrombocytopenia is a common occurrence (20%) in sick neonates, but the causes have not been well studied. In this report we demonstrate that thrombocytopenia in the neonate is characterized by increased platelet destruction as shown by shortened homologous 111In-oxine-labeled platelet life spans. Thirty-one prospectively studied thrombocytopenic neonates were investigated by measuring the 111In-labeled platelet life span, platelet-associated IgG (PAIgG), and coagulation screening tests. In every infant, the thrombocytopenia was shown to have a destructive component since the mean platelet life span was significantly shortened to 65 +/- 6 (mean +/- SEM) hours with a range of one to 128 hours compared with adult values (212 +/- 8; range, 140 to 260; gamma function analysis). The platelet survival was directly related to the lowest platelet count and inversely related to both the highest mean platelet volume and duration of the thrombocytopenia. In 22 infants the percent recovery of the radiolabeled platelets was less than 50%, which suggested that increased sequestration also contributed to the thrombocytopenia. Infants with laboratory evidence of disseminated intravascular coagulation (n = 8) or immune platelet destruction evidenced by elevated levels of PAIgG (n = 13) had even shorter platelet survivals and a more severe thrombocytopenia compared with the ten infants in whom an underlying cause for the thrombocytopenia was not apparent. Full-body scintigraphic images obtained in 11 infants showed an increased uptake in the spleen and liver, with a spleen-to- liver ratio of 3:1. This study indicates that thrombocytopenia in sick neonates is primarily destructive, with a subgroup having evidence of increased platelet sequestration.     

Sera from patients with heparin-induced thrombocytopenia generate platelet-derived microparticles with procoagulant activity: an explanation for the thrombotic complications of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia is characterized by moderate thrombocytopenia and thrombotic complications, whereas quinine/quinidine-induced thrombocytopenia usually presents with severe thrombocytopenia and bleeding. Using flow cytometry and assays of procoagulant activity, we investigated whether sera from patients with these immune drug reactions could stimulate normal platelets to generate platelet-derived microparticles with procoagulant activity. Sera or purified IgG from patients with heparin-induced thrombocytopenia stimulated the formation of platelet-derived microparticles in a heparin-dependent fashion. Further studies showed that heparin-induced thrombocytopenia sera also produced a marked increase in procoagulant activity. In contrast, sera from patients with quinine- or quinidine-induced thrombocytopenia did not generate platelet-derived microparticles nor generate increased procoagulant activity. However, quinine/quinidine-induced thrombocytopenia sera produced a significant increase in the binding of IgG to platelets in a drug-dependent fashion, whereas sera from patients with heparin-induced thrombocytopenia demonstrated no drug-dependent binding of IgG to platelets. We also observed increased levels of circulating microparticles in patients with acute heparin-induced thrombocytopenia compared with control patients. Our observations indicate that the generation of procoagulant platelet-derived microparticles in vivo is a plausible explanation for the thrombotic complications observed in some patients with heparin-induced thrombocytopenia.     

蝙蝠葛中的新生物碱——蝙蝠葛新林碱

防已科植物蝙蝠葛(Menispermum daurioum DC.)的根茎,即北豆根,是一种重要的中药,具有清热解毒、消肿止痛等功效。已知含有近二十种生物碱,其中五种属双苄基四氢异喹啉类,即蝙蝠葛碱(dauricine,Ⅰ)、蝙蝠葛诺林碱(daurinoline,Ⅱ)、蝙蝠葛新诺林碱