Measurement of hepatic perfusion with dynamic computed tomography: assessment of normal values and comparison of two methods to compensate for motion artifacts

RATIONALE AND OBJECTIVES: To assess normal values of hepatic perfusion by dynamic, single-section computed tomography, to compare two methods of data processing (a smoothing with a fitting procedure), and to evaluate the influence of motion artifacts. METHODS: Twenty-five volunteers with no history or suspicion of liver disease were examined (age range, 32.8-81.1 years). All examinations were subjectively ranked into groups 1 through 3 according to the degree of motion artifacts (negligible, moderate, severe). All data were processed with a smoothing procedure and a pharmacokinetic fitting procedure (TopFit). The arterial, portal venous, and total hepatic perfusion; the hepatic perfusion index (HPI); and the arterial/portal venous ratio (A/P ratio) were calculated with both procedures. RESULTS: Mean hepatic perfusion, as assessed with the fitting procedure and the smoothing procedure, respectively, was as follows: arterial, 0.20 and 0.22 mL x min(-1) x mL(-1); portal venous, 1.02 and 1.24 mL x min(-1) x mL(-1); total perfusion, 1.22 and 1.47 mL x min(-1) x mL(-1); HPI, 16.4% and 15.4%; and A/P ratio, 0.20 and 0.19. The differences were significant for the portal venous and total hepatic perfusion. The portal venous and total hepatic perfusion values showed significant differences between group 1 and groups 2 and 3 for both procedures. HPI and the A/P ratio showed no significant differences at all. CONCLUSIONS: Motion artifacts and the type of data processing influence the assessment of the arterial, portal venous, and total hepatic perfusion but do not influence measurement of the HPI and the A/P ratio.     

Immuntherapeutische Behandlung therapierefraktärer und rezidivierter akuter lymphatischer Leukämien im Kindes- und Jugendalter

Acute lymphoblastic leukemia (ALL) represents the most frequent malignant disease in childhood and adolescence and offers a good prognosis with approximately 80% survival in first remission after polychemotherapy and radiotherapy. In addition,many children with relapsed or refractory ALL will still be cured by allogeneic hematopoietic stem cell transplantation (alloHSCT).However, therapeutic options are limited with a very poor prognosis in case of another relapse after alloHSCT.Here,immunotherapy strategies offer a promising alternative to another chemotherapy or second alloHSCT, which are mainly palliative and accompanied by high morbidity and mortality. Immunotherapy strategies aim at an improvement of the graft-versus-leukemia (GvL) effect.The therapeutic GvL effect is usually associated with graft-versus-host disease (GvHD).The definition of patients subgroups with an increased risk for relapse after alloHSCT gains growing importance for immunotherapy strategies.Promising approaches for separation of GvL-effect and GvHD after donor lymphocyte infusions, e.g. T-cell suicide gene therapy, will be described. Finally, vaccination strategies for ALL exist.     

Knowledge and attitudes about otitis media risk: implications for prevention

OBJECTIVES: To investigate maternal knowledge and attitudes about otitis media (OM) risk, to estimate the prevalence of risk factors in the first year of life, and to identify barriers to the reduction of risk factors (eg, formula feeding, day care attendance, and exposure to passive smoke). METHODS: Questionnaires mailed to a systematic sample of 504 Minnesota women >/=18 years old identified through 1994 birth certificates. RESULTS: Eighty percent returned a completed survey. According to maternal report, 29% of infants (age 8 to 13 months) had recurrent OM (>/=3 episodes) and 2% had tympanostomy tubes. Forty-six percent attended day care, 29% had >/=1 smoking parent, and 49% breastfed for 相似文献   

Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon

We have examined whether dietary polyamines influence the formation and initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rat colon. Effects of a combination of dietary polyamines at three dose levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g; spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied in animals in two different experimental situations: animals treated with AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a specific inhibitor of endogenous polyamine synthesis. In both experimental situations, dietary polyamines enhanced the growth of ACF, expressed as the number of large ACF (foci with three or more aberrant crypts, ACF > or = 3), whereas the formation of ACF, expressed as the number of ACF, was apparently not altered. In animals treated with AOM alone, maximal growth enhancing effect on ACF was nearly obtained with the median level of dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of DFMO was counteracted by dietary polyamines in a dose- dependent manner, and it was abolished at the highest level of polyamines. In conclusion, it was demonstrated that dietary polyamines are able to enhance the growth of AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused inhibition of ACF growth, probably by compensating for the DFMO-reduced endogenous polyamine synthesis.      

From genotype to phenotype--behavior of the transgenic rat TGR(mRen2)27 as an example

Transgenic techniques provide a tool to generate animals that differ from the wild-type by one or more genes, either by introducing foreign genes (transgenic animals) or by specific mutations of genes (knock-out animals). Most transgenic and knock-out animals are mice and not rats. The frequent use of rat models in the behavioral laboratory, however, will require the increasing application of transgenic techniques in this species. This paper reviews behavioral data from our laboratory as an example of characterizing the behavioral phenotype of a particular transgenic rat, the TGR(mRen2)27 rat. By describing the anxiogenic profile of this rat we also consider some problems associated with such an analysis, with the intention to raise issues that may also apply to studies of behavior in transgenic animals in general.     

二甲双胍治疗抗精神病药物引起的血脂异常:两项随机、安慰剂的对照研究

目的：验证二甲双胍治疗抗精神病药引起的血脂异常的疗效和安全性。方法：将两项随机、安慰剂的 对照研究纳入分析。共有201例服用抗精神病药物后出现血脂异常的首发精神分裂症患者,并将其分为1 000 mg/d 二甲双胍组(以下简称为二甲双胍组,n=103)和安慰剂组(n=98),观察24周。在基线、治疗后第12周和第24周进行 临床症状及体重、血糖、血脂等代谢指标的评估。结果：二甲双胍治疗后,二甲双胍组和安慰剂组之间低密度脂 蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)的平均差异从基线时的0.16 mmol/L,降低到第24周结束时的 –0.86 mmol/L,降低了1.02 mmol/L,差异有统计学意义(P<0.01)。而24周结束时,二甲双胍组LDL-C≥3.37 mmol/L的 患者有25.3%,显著低于安慰剂组24周结束时的64.8%(P<0.01)。与安慰剂组相比,二甲双胍组的体重、体重指数、 胰岛素、胰岛素抵抗指数、总胆固醇、三酰甘油和高密度脂蛋白胆固醇也有显著变化,差异均有统计学意义(均 P<0.05)。治疗对体重和胰岛素抵抗的影响出现在第12周,并且在第24周进一步改善,但对改善血脂异常的作用在第 24周结束时才出现。结论：二甲双胍治疗对于改善抗精神病药物引起的血脂异常和胰岛素抵抗是有效的,并且改善 抗精神病药物诱导的胰岛素抵抗出现的时间早于降低血脂异常的时间。