Combined time-resolved and high-spatial-resolution 3D MRA using an extended adaptive acquisition

PURPOSE: To combine the benefits of time-resolved dynamic imaging and single elliptical centric acquisitions in a reasonable scan time. MATERIALS AND METHODS: A time series of images with moderate spatial resolution was acquired using the 3D Time-Resolved Imaging of Contrast KineticS (3D TRICKS) technique with elliptical centric encoding during contrast arrival. Following venous opacification, a complete large centrically encoded k-space volume was acquired. The high-spatial-frequency portions of this volume were combined with a 3D TRICKS time frame to form a high-resolution image. An additional single image is formed by suppressing background and signal averaging all acquired data, including post-venous low-spatial-frequency data. For this image, 2D temporal correlation analysis is used to suppress low-spatial-frequency vein contributions. Arrival time and spatial correlations are used to suppress background. RESULTS: The 3D TRICKS time frame may be selected to ensure a combined high-resolution image that has optimal central k-space sampling for any vascular region. The single image formed by signal averaging all acquired data has increased contrast-to-noise (CNR) and signal-to-noise (SNR) ratios. CONCLUSION: The advantages of time-resolved and high-spatial-resolution imaging were combined using an extended dual-phase acquisition. Some SNR and CNR gain was achieved by signal averaging. This process is facilitated by background and vein suppression.     

军团菌在巨噬细胞与中性粒细胞内的生长效应研究

目的探索比较军团菌毒性株在巨噬细胞与中性粒细胞内的生长效应.方法诱导分化人的单核细胞系U937细胞使其成为类巨噬细胞,并分离诱导人的外周血单核巨噬细胞以及中性粒细胞;用不同生长时期的军团菌毒力株AA100,感染诱导分化成功的单核巨噬细胞和中性粒细胞,并比较其在巨噬细胞和中性粒细胞中的生长复制状况.结果过对数生长期的军团菌毒力株能够在巨噬细胞内大量复制,扩增状况呈生长阶段的依赖性;而各生长时期的军团菌毒力株均不能在中性粒细胞内大量扩增.结论军团菌逃逸机体的杀伤作用和免疫监视作用与其能够在巨噬细胞内大量复制密切相关.     

Bile salt independent flow during bile salt-induced choleresis and cholestasis in the rat: role of biliary thiol secretion

AIMS/BACKGROUND: Previous studies have shown that the generation of the so-called "bile salt-independent flow" (BSIF) may be partly dependent on the hepatic availability and rate of canalicular secretion of osmotically active substances such as glutathione (GSH) and derived thiols. This study examined the role of common bile salts (BS) on the BSIF formation under both choleretic and cholestatic conditions, and on the relationship of the BSIF to the biliary thiol secretion. METHODS: Experiments were carried out in adult male Sprague-Dawley rats both in situ in the isolated perfused rat liver and in vivo. The effect of choleretic and cholestatic doses of BS on the biliary BS secretion rate (BSSR), BS-dependent flow (BSDF), and BSIF was evaluated. RESULTS: In the perfused rat liver, the infusion of low and physiological doses of taurocholic acid stimulated the biliary BSSR, BSDF, and BSIF. This was associated with increased biliary thiol secretion and thiol-dependent bile flow. In vivo administration of taurocholic acid, taurochenodeoxycholic acid or taurolithocholic acid in step-wise increasing doses leading to cholestasis showed that the onset of cholestasis was not accompanied by a significant decline in the BSSR or BSDF but rather by a marked inhibition of the apparent BSIE During cholestasis, the three BS produced a significant reduction of biliary thiol secretion, with a marked decrease in thiol-dependent bile flow sufficient to account for a major proportion of BSIF inhibition. This decline in thiol secretion occurred before the drop in biliary BS secretion and was more pronounced than the reduction in BS output. No change in hepatic thiol content was observed. Administration of free or glyco-conjugated BS also resulted in a significant decrease of BSIF during the cholestatic period, suggesting a common role for BSIF inhibition in BS-induced cholestasis. CONCLUSION: The changes in bile flow during BS-induced choleresis and cholestasis are mediated by changes in the portion of the BSIF regulated by the thiol secretion.     

Percutaneous nephrostomy in neonates and infants

A total of 8 patients between 2 days and 2 years old underwent 13 percutaneous nephrostomies for treatment of hydronephrosis. No significant complications were encountered.     

Sex differences in the bile acid composition of human bile: Studies in patients with and without gallstones

The bile acid composition of human gallbladder bile was studied in 83 subjects, 20 of each sex without discernible hepatobiliary disease, and 20 men and 23 women with cholelithiasis. The bile acids were measured by combined thin-layer and gas-liquid chromatography.

In the bile of patients without cholelithiasis the molar percent of cholic acid was significantly greater in men while that of chenodeoxycholic acid was significantly greater in women.

In the bile of patients with cholelithiasis the concentration of total bile acids was reduced in both sexes but there was no sex difference in the molar percent of any of the bile acids. The molar percent of CDCA (both glycine and taurine conjugates) was reduced in women, while the molar percent of CA (only the glycine conjugate) was reduced in men.

     

Congenital varicella-zoster virus infection. A rare case of severe brain and ocular malformations without limb or cutaneous involvement in a newborn after maternal subclinical infection

Although congenital varicella-zoster virus VZV infection is rare, it carries serious morbidity and mortality to the fetus and newborn infant. We report a full term female newborn infant, born to a multipara unbooked mother who had VZV subclinical infection during the first trimester of pregnancy. Routine newborn examination showed cystic malformation of the left eye, and absence of the right eye globe. Radiological work up revealed severe brain and eye malformations, serological studies of both mother and baby were positive for VZV. The baby underwent palliative surgery to the eyes, upon discharge, a plan of multidisciplinary team was made for follow up including neurologist, ophthalmologist, pediatrician and social worker. Congenital VZV infection can be severe enough to cause catastrophic fetal anomalies and damage to the vital organs as many of those infants die in infancy.