Flucytosine Dosing in an Obese Patient With Extrameningeal Cryptococcal Infection

A 31-year-old, obese woman with extrameningeal cryptococcal disease was admitted to the Medical College of Virginia for antifungal therapy. Various physiologic variables influence flucytosine pharmacokinetics, and there are no guidelines for dosing the agent in obese patients. This patient received a dosage based on her ideal body weight, and serum drug concentrations were monitored. She recovered without sequelae.     

间充质干细胞的来源

目的:间充质干细胞具有强大的增殖能力和多向分化潜能,文章对其主要的来源途径予以综述。资料来源:应用计算机检索Medline1991-01/2006-01期间的相关文章,检索词为“mesenchyma stem cells,origin,research progress”,并限定文章语言种类为English。同时计算机检索中国期刊全文数据库1998-01/2006-10期间的相关文章,检索词为“间充质干细胞,来源,研究进展”,并限定文章语言种类为中文。资料选择:对资料进行初审,并查看每篇文献后的引文。纳入标准:①间充质干细胞的起源。②间充质干细胞研究进展、干细胞的分离及鉴定。排除标准:重复研究、个案报告或Meta分析类文章。资料提炼:共收集到96篇相关文献,40篇文献符合纳入标准,排除的56篇文献为内容陈旧或重复。符合纳入标准的40篇文献中,分别涉及骨髓、肌肉、脐血、胎盘、外周血、脂肪组织、血管及其他来源的间充质干细胞。资料综合:间充质干细胞是属于中胚层的一类多能干细胞,具有强大的增殖能力和多向分化潜能,动物模型试验和临床应用研究也取得了一定的效果。间充质干细胞来源广泛,易于获得,临床上为神经损伤及其他系统的损伤修复提供了更为广泛的途径。结论:间充质干细胞主要来源于骨髓、肌肉、脐血、外周血、胎盘等组织,具有广阔的应用前景。     

Occurrennce and impact of community-acquired and nosocomial rotavirus infections — a hospital-based study over 10 y

The need for a rotavirus vaccine in any particular country depends primarily on the number of hospitalized cases. Since only limited data are available for Germany, we undertook a retrospective hospital-based analysis in order to gather further information. From 1987 through 1996, a total of 3618 inpatients were hospitalized with a diagnosis of gastroenteritis (ICD 9). In 892 (25%) of them the causative organism wasa rotavirus. During the same period, 1886 (out of 8383; 22%) stool speciment tested in the hospital laboratory were obtained from rotavirus-positive inpatients. In 49.2% the infection was community-acquired, and in the remainder of nosocomial origin. Infants under 4 months of age(n=709; 38%) predominated among both the nosocomial and community-acquired infections. Premature neonates made up 26% of the nosocomial, but only 2% of the community-acquired cases of diarrhoea. The winter peak (January) was most pronounced in the age group 4-12 months, but in those more than 1 y old the peak came a month later. The median hospitalization time for community-acquired cases was 4 d (mean 5.9 d).The mortality was 0.1%. Rotavirus infection must therefore be regarded as a considerable burden, particularly with regard to infants and young children. Furthermore, the morbidity due to nosocomial infection with the rotavirus, analysed here in a long-term observational study, is unexpectedly high. □ Hospital-based study, nosocomial infection, rotavirus     

Acute pyelonephritis as a cause of late transplant dysfunction

In a renal transplant recipient, acute pyelonephritis of the allograft developed in association with acute deterioration of renal function. No other cause of renal dysfunction was delineated, and the serum creatinine level promptly returned to baseline with antimicrobial therapy. Acute pyelonephritis is an important cause of late transplant dysfunction, and prompt diagnosis and treatment result in complete recovery of renal function.     

The association of the ratio of waist to hip girth with blood pressure, serum cholesterol and serum uric acid in children and youths aged 6-17 years

To determine whether the association of the ratio of waist to hip girth with cardiovascular risk factors exists in prepubertal children and pubertal youths, the ratio was related to blood pressure, serum cholesterol and serum uric acid levels in children and youths aged 6-17 yr in the Health Examination Survey. In these samples drawn from the United States population, the ratio declined with increasing age. Boys had consistently higher ratios than girls. Black-white differences were inconsistent. The ratio was lower in girls whose menstrual periods had started at each age after 10. The ratio was significantly associated with systolic blood pressure in youths and with diastolic blood pressure in children independent of confounders. It was also significantly associated with serum uric acid but not serum cholesterol independent of confounders among youths. Longitudinal studies are needed of greater abdominal relative to lower body fat deposits in children and youths and risk of cardiovascular disease in adulthood.     

Cerebral blood flow relationships associated with a difficult tone recognition task in trained normal volunteers

Tone recognition is partially subserved by neural activity in the right frontal and primary auditory cortices. First we determined the brain areas associated with tone perception and recognition. This study then examined how regional cerebral blood flow (rCBF) in these and other brain regions correlates with the behavioral characteristics of a difficult tone recognition task. rCBF changes were assessed using H2(15)O positron emission tomography. Subtraction procedures were used to localize significant change regions and correlational analyses were applied to determine how response times (RT) predicted rCBF patterns. Twelve trained normal volunteers were studied in three conditions: REST, sensory motor control (SMC) and decision (DEC). The SMC-REST contrast revealed bilateral activation of primary auditory cortices, cerebellum and bilateral inferior frontal gyri. DEC-SMC produced significant clusters in the right middle and inferior frontal gyri, insula and claustrum; the anterior cingulate gyrus and supplementary motor area; the left insula/claustrum; and the left cerebellum. Correlational analyses, RT versus rCBF from DEC scans, showed a positive correlation in right inferior and middle frontal cortex; rCBF in bilateral auditory cortices and cerebellum exhibited significant negative correlations with RT These changes suggest that neural activity in the right frontal, superior temporal and cerebellar regions shifts back and forth in magnitude depending on whether tone recognition RT is relatively fast or slow, during a difficult, accurate assessment.      

Iron and Heart Disease: The Epidemiologic Data

There has developed a general theory of chronic and degenerative disease causation—the Oxidative Stress Theory. This theory states that the production of tissue-damaging free radicals is an essential component in the pathogenesis of chronic diseases and that iron may help to catalyze the reactions producing free radicals. As a result, it has been suggested that the risk of coronary heart disease increases with increasing body iron stores. In support of that hypothesis, a prospective epidemiologic study of heart disease in Finnish men found that the risk of heart attack increased with increasing levels of serum ferritin. However, the vast majority of the epidemiologic data, including results from prospective, cross-sectional, and case-control and autopsy studies, published since that initial study have failed to support the original hypothesis that high body iron stores increase the risk of coronary heart disease.     

Determinants of vancomycin clearance by continuous venovenous hemofiltration and continuous venovenous hemodialysis

The clearance of vancomycin is significantly reduced in patients with acute, as well as, chronic renal failure. Although multiple-dosage regimen adjustment techniques have been proposed for these patients, there is little quantitative data to guide the individualization of vancomycin therapy in acute renal failure patients who are receiving continuous renal replacement therapy (CRRT). To determine appropriate vancomycin dosing strategies for patients receiving continuous venovenous hemofiltration (CVVH) and continuous venovenous hemodialysis (CVVHD), we performed controlled clearance studies in five stable hemodialysis patients with three hemofilters: an acrylonitrile copolymer 0.6 m2 (AN69), polymethylmethacrylate 2.1 m2 (PMMA), and polysulfone 0.65 m2 (PS). Patients received 500 mg of vancomycin intravenously at least 12 hours before the start of the clearance study. The concentration of vancomycin in multiple plasma and dialysate/ultrafiltrate samples was determined by EMIT (Syva, Palo Alto, CA). The diffusional clearance and sieving coefficient (SC) of vancomycin were compared by a mixed-model repeated-measures analysis of variance (ANOVA) with filter and blood (Q(B)), dialysate inflow (Q(DI)), or ultrafiltration rate (Q(UF)) as the main effects and patient as a random effect. Vancomycin was moderately protein bound in these patients; free fraction ranged from 49% to 83%. The SCs of the three filters were similar and significantly correlated with the free fraction of vancomycin (P = 0.01; r2 = 0.465). Significant linear relationships were observed between the diffusional clearance of vancomycin and Q(DI) for all three filters: AN69 (slope = 0.482; r2 = 0.880); PMMA (slope = 0.853; r2 = 0.966); and PS (slope = 0.658; r2 = 0.887). The slope of this relationship for the PMMA filter was significantly greater than that of the AN69 and PS filters. The clearance of vancomycin, urea, and creatinine, however, was essentially constant at all Q(B)s for all three filters. Thus, the clearance of vancomycin was not membrane dependent during CVVH. However, during CVVHD, membrane dependence of vancomycin clearance was noted at a Q(DI) greater than 16.7 mL/min; vancomycin clearance with PMMA at a Q(DI) of 25 mL/min was 66% and 43% greater than that with the AN69 and PS filters, respectively. CVVH (62% to 262%) and CVVHD (90% to 540%) can significantly augment the clearance of vancomycin in acute renal failure patients. Dosing strategies for individualization of vancomycin therapy in patients receiving CVVH and CVVHD are proposed.