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.     

Therapy of patients with human T-cell lymphotrophic virus I-induced adult T-cell leukemia with anti-Tac, a monoclonal antibody to the receptor for interleukin-2

Human T-cell lymphotropic virus I (HTLV-I)-induced adult T-cell leukemia (ATL) cells constitutively express interleukin-2 (IL-2) receptors identified by the anti-Tac monoclonal antibody (MoAb), whereas normal resting cells do not. This observation provided the scientific basis for a trial of intravenous anti-Tac in the treatment of nine patients with ATL. The patients did not suffer untoward reactions and did not have a reduction in the normal formed elements of the blood, and only one of the nine produced antibodies to the anti-Tac MoAb. Three patients had transient mixed, partial, or complete remissions lasting from 1 to more than 8 months after anti-Tac therapy, as assessed by routine hematologic tests, immunofluorescence analysis of circulating cells, and molecular genetic analysis of HTLV-I provirus integration and of the T-cell receptor gene rearrangement. The precise mechanism of the antitumor effects is unclear; however, the use of a MoAb that prevents the interaction of IL-2 with its receptor on ATL cells provides a rational approach for the treatment of this malignancy.     

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.     

Ultrastructural observations on beaded α-motoneuron dendrites

Beaded dendrites of 1α-motoneurons intracellularly labelled with horseradish peroxidase (HRP) were studied ultrastructurally in eight adult cats. For comparison, adjacent unlabelled beaded dendrites of unknown origin were also included in the study. Electron microscopy revealed no signs of degeneration or poor fixation according to common criteria. With the exception of the HRP-reaction product no difference in structure was observed between labelled and unlabelled beaded dendrites. Both the beads and their interconnecting segments were postsynaptic to boutons of normal appearance containing spherical (S-type boutons) or flattened vesicles (F-type boutons). The values for synaptic covering and synaptic packing density of the beaded dendritic regions, which usually were located in the periphery of the dendritic trees, were clearly lower than values obtained previously for cell bodies and proximal dendrites of a-motoneurons.     

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。     

Novel APC-cleavage sites in FVa provide insights into mechanisms of action of APC and its cofactor protein S

Summary.  Background: Activated protein C (APC) inhibits factor Va (FVa) by cleaving at Arg306, Arg506 and Arg679. Protein S serves as cofactor, in particular for the Arg306 site, and a protein S-mediated relocation of the active site of APC closer to the membrane has been proposed as a mechanism. Recently, it was demonstrated that FVa, which was mutated at all three APC-cleavage sites (FVa-306Q/506Q/679Q), could still be cleaved by APC. These sites were close to Arg306 and Arg506 but not further defined. Objective: To identify and characterize the additional APC-cleavage sites in FVa. Methods: The cDNA for FV-306Q/506Q/679Q was used as a template to create FV variants with one or more possible cleavage sites being mutated. The FV variants were expressed and their sensitivity for APC characterized functionally and with Western blotting. Results: The additional APC-cleavage sites were located at Lys309, Arg313, Arg316, Arg317 and Arg505. FVa-306Q/309Q/313Q/316Q/317Q/505Q/506Q/679Q (denoted 8M-FVa) was APC resistant. To investigate individual sites, they were mutated back using 8M-FV as a template. The kinetics of APC-degradation of these variants demonstrated that protein S was equally efficient in enhancing the APC effect for all the novel sites. Conclusions: Multiple APC-cleavage sites close to Arg306 and a single site close to Arg506 were identified. Protein S was equally efficient as APC cofactor for all novel sites. The stimulation by protein S of the Arg505 cleavage argues against a specific protein S-mediated stimulation of cleavage at Arg306 due to relocation of the APC active site closer to the membrane.     

Gastric ulcer disease in infants: US findings

Among 600 infants examined with ultrasound for vomiting, seven (mean age, 3 months) had distinctive features that can be considered diagnostic of gastric ulcer. The findings are thickening of the mucosa (greater than 4 mm) in the antropyloric region, elongation of the antropyloric canal, persistent spasm, and delayed gastric emptying. Two of the infants had slight thickening of the pyloric muscle. Gastrointestinal series or endoscopy demonstrated thickened gastric mucosa and a deformed gastric antrum in all infants, as well as actual ulceration in five.