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.     

The coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac disease in school-age subjects

Background : Recent studies suggest that coeliac disease (CD) is one of the commonest, life-long disorders in Italy. The aims of this multicentre work were: (a) to establish the prevalence of CD on a nationwide basis; and (b) to characterize the CD clinical spectrum in Italy. Patients and methods : Fifteen centres screened 17201 students aged 6–15 years (68.6% of the eligible population) by the combined determination of serum IgG- and IgA-antigliadin antibody (AGA) test; 1289 (7.5%) were IgG and/or IgA-AGA positive and were recalled for the second-level investigation; 111 of them met the criteria for the intestinal biopsy: IgA-AGA positivity and/or AEA positivity or IgG-AGA positivity plus serum IgA deficiency. Results : Intestinal biopsy was performed on 98 of the 111 subjects. CD was diagnosed in 82 subjects (75 biopsy proven, 7 not biopsied but with associated AGA and AEA positivity). Most of the screening-detected coeliac patients showed low-grade intensity illness often associated with decreased psychophysical well-being. There were two AEA negative cases with associated CD and IgA deficiency. The prevalence of undiagnosed CD was 4.77 × 1000 (95% CI 3.79–5.91), 1 in 210 subjects. The overall prevalence of CD, including known CD cases, was 5.44 × 1000 (95% CI 4.57–6.44), 1 in 184 subjects. The ratio of known to undiagnosed CD cases was 1 in 7. Conclusions : These findings confirm that, in Italy, CD is one of the most common chronic disorders showing a wide and heterogeneous clinical spectrum. Most CD cases remain undiagnosed unless actively searched.     

Reduced upper airway nitric oxide in cystic fibrosis

PURPOSE: Incidence data for severe aplastic anaemia (SAA) in children are scanty and vary. Few population based studies have been reported. A retrospective and prospective study was conducted to determine the incidence and course of SAA. PATIENTS AND METHODS: All children with a diagnosis of SAA in the Nordic countries from 1982 through 1993 were registered and have been followed up since 1987. RESULTS: A total of 101 children were diagnosed with SAA. The mean annual child population was 4.31 million. A constant incidence of 1.95/million children/year was found: 2.4 for boys and 1.5 for girls. A non-significant increase of cases occurred from November to March. Possible aetiological agents were noted in 29%. The actuarial survival was 79% after one year and 68% after five years without significant difference between boys and girls. CONCLUSION: The incidence of SAA in the Nordic countries remains stable with a preponderance among boys. SAA has still a high initial mortality and a risk of late deaths.     

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.