Angular versus spatial resolution trade‐offs for diffusion imaging under time constraints

Diffusion weighted magnetic resonance imaging (DW‐MRI) are now widely used to assess brain integrity in clinical populations. The growing interest in mapping brain connectivity has made it vital to consider what scanning parameters affect the accuracy, stability, and signal‐to‐noise of diffusion measures. Trade‐offs between scan parameters can only be optimized if their effects on various commonly‐derived measures are better understood. To explore angular versus spatial resolution trade‐offs in standard tensor‐derived measures, and in measures that use the full angular information in diffusion signal, we scanned eight subjects twice, 2 weeks apart, using three protocols that took the same amount of time (7 min). Scans with 3.0, 2.7, 2.5 mm isotropic voxels were collected using 48, 41, and 37 diffusion‐sensitized gradients to equalize scan times. A specially designed DTI phantom was also scanned with the same protocols, and different b‐values. We assessed how several diffusion measures including fractional anisotropy (FA), mean diffusivity (MD), and the full 3D orientation distribution function (ODF) depended on the spatial/angular resolution and the SNR. We also created maps of stability over time in the FA, MD, ODF, skeleton FA of 14 TBSS‐derived ROIs, and an information uncertainty index derived from the tensor distribution function, which models the signal using a continuous mixture of tensors. In scans of the same duration, higher angular resolution and larger voxels boosted SNR and improved stability over time. The increased partial voluming in large voxels also led to bias in estimating FA, but this was partially addressed by using “beyond‐tensor” models of diffusion. Hum Brain Mapp 34:2688–2706, 2013. © 2012 Wiley Periodicals, Inc.     

Histology as a diagnostic tool for intestinal isosporiasis in immunocompromised patients

Isospora belli is an opportunistic protozoan causing wasting diarrhea especially in patients with an immunocompromised status. Diagnosis is usually established by demonstrating the oocyst of the organism on stool examination, which however can often be inconclusive. Serological tests for isosporiasis are currently not available. In such a scenario, biopsy often provides evidence for a confirmatory diagnosis. We describe two such cases, in which intestinal biopsy was the only diagnostic evidence of isosporiasis as the cause for chronic diarrhea.     

全破壁灵芝孢子治疗男性更年期综合征

目的 :探讨全破壁灵芝孢子治疗法对男性更年期综合征的疗效。方法 :通过对 138例诊断为男性更年期综合征病人分组 ,其中 80例作全破壁灵芝孢子胶囊治疗并对其临床症状 ,血睾酮、SOD、MDA水平及主观抑郁症状评分作观察 ,并与 5 8例病情相同的病人予安慰剂对照。结果 :治疗组的病人症状改善率为 74 .3% ,血睾酮水平 3周前后分别为 (131.5 1± 19.12 )mg/L与 (2 5 3.78± 2 1.4 5 )mg/L ,SOD水平 3周前后分别为 (10 6 8.3± 12 1.4 )U/ g·Hb与 (1178.1± 132 .6 )U/ g .Hb ,MDA水平 3周前后分别为 (7.6± 0 .8) μmol/L与 (5 .8± 0 .6 )μmol/L。抑郁症状评分各指标均有较大改善。 结论 :全破壁灵芝孢子胶囊是治疗男性更年期综合征的一种有效、安全的方法。     

Comparative oxycodone pharmacokinetics in humans after intravenous, oral, and rectal administration.

The pharmacokinetics of oxycodone have been determined after single-dose administration by the intravenous (4.6-7.3 mg), oral (tablets, 9.1 mg and syrup, 9.1 mg), and rectal (30 mg) routes, in 48 patients undergoing minor surgery. There were no significant differences in the mean elimination half-lives between the intravenous (5.45 +/- 1.43 h), oral tablets (5.65 +/- 1.13 h), oral syrup (4.80 +/- 1.13 h), and rectal suppository (5.40 +/- 1.19 h) formulations of oxycodone. After intravenous administration, the mean plasma clearance of oxycodone was 25.5 +/- 10.1 L/h and the mean volume of distribution at steady state was 2.5 +/- 0.8 L/kg. The mean normalized area under the curve (AUC/D) obtained after intravenous dosing (48.2 +/- 30.2 micrograms.h/L/mg) was more than twice the AUC/D values obtained after the administration of oxycodone tablets (19.8 +/- 3.5 micrograms.h/L/mg), oxycodone syrup (17.5 +/- 5.3 micrograms.h/L/mg), and rectal suppository (20.3 +/- 5.1 micrograms.h/L/mg), indicating that the amount of oxycodone reaching the systemic circulation after the extravascular routes of administration was < 50% of that obtained after intravenous dosing. The mean absorption lag times after oxycodone tablets (0.52 +/- 0.33 h), oxycodone syrup (0.48 +/- 0.40 h), and rectal suppository (0.76 +/- 0.47 h) were consistent with the onset of pharmacological effects reported by the patients.     

速度滑冰与短道速度滑冰运动员身体功能评定

目的:总结速度滑冰与短道速度滑冰运动员各项生理生化指标,开发应用生理生化指标对身体功能进行评定,为科学训练提供参考依据。方法:分析速度滑冰与短道速度滑冰项目特点,并根据其特点制定了各项生理生化指标的参考值。结果:速度滑冰与短道速度滑冰均有周期性耐力性项目特点,要求运动员必须具备较强的无氧代谢能力,尤其是抗乳酸能力,可用4mmol/L做无氧阈训练监控指标。血尿素参考值4￣7mmol/L,功能下降或训练量大时增高。血清肌酸激酶强度训练时可高达16.67μkat/L以上。血红蛋白参考值为男120￣160g/L,女110￣150g/L。免疫指标和内分泌指标均应定期监测,为提供身体功能信息有重要意义。结论:可用血乳酸系统监控和评估有氧与无氧耐力水平,运动员身体功能评定是科学化训练重要保证,是科学训练的重要部分。     

Detection of Mycobacterium tuberculosis in bronchoalveolar lavage from patients with sputum smear-negative pulmonary tuberculosis using a polymerase chain reaction assay

Abstract The objective of this study was to evaluate the utility of a polymerase chain reaction (PCR) assay in detecting Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) specimens of patients suspected of having active pulmonary tuberculosis (TB) but who were sputum smear-negative. Patients undergoing investigation for suspected pulmonary TB at the University Hospital, Kuala Lumpur, and who were sputum smear-negative underwent fibreoptic bronchoscopy and BAL. One portion of each lavage specimen was submitted for smear examination for acid-fast bacilli and mycobacterial culture and the other portion assayed by PCR for the presence of a 562-base pair DNA segment belonging to the insertion sequence IS986, unique to the M. tuberculosis complex. As controls, lavage specimens from patients with other lung lesions were also similarly tested. The PCR assay gave a positivity rate of 80.9% (55 of 68) compared with 8.8% of smear examination and 7.4% of culture for detecting M. tuberculosis in BAL specimens. The assay was positive in two of 45 BAL specimens from 35 control subjects. The PCR assay was more sensitive than smear and culture in detecting M. tuberculosis in BAL specimens of patients with sputum smear-negative pulmonary TB.     

The heterogeneity of type IIA von Willebrand's disease: studies with protease inhibitors

The absence of large von Willebrand factor (vWF) multimers from plasma is a characteristic of Type IIA von Willebrand's disease (vWD) and is thought to contribute to the clinical expression of this disorder. Recently, three IIA patients have been reported in whom intermediate and large multimers could be restored if blood were collected in 5 mm EDTA, 6 mmol/L N-ethylmaleimide, and 1 mmol/L leupeptin. This suggested that absence of large multimers resulted from in vitro proteolysis. We have now collected blood from ten Type IIA vWD patients in these inhibitors but were not able to detect large multimers in the plasma of any of them. In addition, intermediate-sized multimers were reduced or completely absent in all. The inclusion of inhibitors in the citrate anticoagulant, as compared to citrate alone, was found to increase the relative proportion of intermediate multimers in some patients but had no effect in others, and in none did it restore large multimers to plasma. The results with platelet vWF were more varied. Four patients showed an absence or decrease of large multimers, whereas in seven patients large multimers were present. When compared with citrate anticoagulant alone, the inclusion of inhibitors in the anticoagulant had little or no effect on the platelet multimeric pattern. 1-Deamino-8- D-Arginine Vasopressin (DDAVP) was administered to six patients from five families. Two patients from one family showed complete correction and a third patient showed almost complete correction of her bleeding time. Two patients showed minimal correction and one showed no detectable correction. An increase in multimer size after DDAVP tended to be associated with correction of the bleeding time. However, in no case did the largest multimers appear in plasma even in patients with complete bleeding time correction. The presence or absence of inhibitors in the anticoagulant had little or no effect on the multimeric pattern after DDAVP. These results indicate that Type IIA vWD is a heterogeneous disorder in which absence of largest and intermediate multimers is an in vivo phenomenon.     

Reexamining treatment of high-grade T1 bladder cancer according to depth of lamina propria invasion: a prospective trial of 200 patients

Background:

Management of high-grade T1 (HGT1) bladder cancer represents a major challenge. We studied a treatment strategy according to substaging by depth of lamina propria invasion.

Methods:

In this prospective observational cohort study, patients received initial transurethral resection (TUR), mitomycin-C, and BCG. Subjects with shallower lamina propria invasion (HGT1a) were followed without further surgery, whereas subjects with HGT1b received a second TUR. Association of clinical and histological features with outcomes (primary: progression; secondary: recurrence and cancer-specific survival) was assessed using Cox regression.

Results:

Median age was 71 years; 89.5% were males, with 89 (44.5%) cases T1a and 111 (55.5%) T1b. At median follow-up of 71 months, disease progression was observed in 31 (15.5%) and in univariate analysis, substaging, carcinoma in situ, tumour size, and tumour pattern predicted progression. On multivariate analysis only substaging, associated carcinoma in situ, and tumour size remained significant for progression.

Conclusions:

In HGT1 bladder cancer, the strategy of performing a second TUR only in T1b cases results in a global low progression rate of 15.5%. Tumours deeply invading the lamina propria (HGT1b) showed a three-fold increase in risk of progression. Substaging should be routinely evaluated, with HGT1b cases being thoroughly evaluated for cystectomy. Inclusion in the TNM system should also be carefully considered.