Noncanonical conformation of nucleic acids: structure with slipped-loops, occurring in DNA oligonucleotides

A HPLC method was developed and validated for the quantitation of 9-cis-retinoic acid (ALRT1057) and its major metabolite, 4-oxo-9-cis-retinoic acid (LG100182) in human plasma. Samples were buffered and extracted with methyl-tert-butyl-ether. The analytes and an I.S. were separated on a C18 HPLC column using a shallow gradient of 70-89% organic solvent. The analytes were quantitated by UV detection at 348 nm. Selectivity against endogenous compounds and potential metabolites (retinol, all trans-, 13-cis-, and 4-hydroxy-9-cis-retinoic acid) was demonstrated. The run time was 29 min. The standard curve was linear from 2.5 to 450 ng ml-1. Interassay precision for both analytes in quality control samples was less than 5.0% RSD. Accuracy was within 11.0% RE for both compounds. Analyte stability during sample storage, extraction processing, and chromatography was established. Method ruggedness was tested by two analysts and on two HPLC systems. This method has been applied to the quantitation of clinical samples.     

Effectiveness of mass neonatal BCG vaccination in the prevention of pulmonary tuberculosis: a case-control study in Nagpur, India

SETTING: Government Medical College, Nagpur, India, a tertiary care hospital. OBJECTIVE: To estimate the effectiveness of mass neonatal BCG vaccination in the prevention of pulmonary tuberculosis in Nagpur, India. DESIGN: A hospital-based pair-matched case-control study with a case of 1:3, including 144 cases of pulmonary tuberculosis and 432 controls. RESULTS: The overall vaccine effectiveness estimated in the present study was 60% (95% Confidence Interval [CI] 43%-72%). The protective effect was more in males in the age group 21-30 years. The prevented fraction was 39% (95% CI 24%-52%). CONCLUSION: The moderate effectiveness demonstrated in this study needs to be substantiated for other forms of tuberculosis by undertaking community-based case-control studies, before attempting to justify the use of mass neonatal BCG vaccination strategy as a part of the national programme.     

Long-term synaptic plasticity in the honeybee

A monosynaptic response was recorded in vivo in the mushroom body of the bee brain, an important site for memory consolidation. Focal electrical stimulation of a major afferent input evoked an extracellular field potential that consisted of a presynaptic fiber volley and a postsynaptic response. We report a long-lasting potentiation of the synaptic response (2.6-fold increase; < or = 3.5 h). Potentiation of the response was induced by low-frequency stimulation (0.02-1.0 Hz), was input specific, and was maintained in the absence of stimulation. Paired-pulse facilitation of the response was converted to paired-pulse depression after potentiation, suggesting a presynaptic mechanism. This is the first demonstration of long-term synaptic plasticity in the insect brain.     

Purification and characterization of a Na+, K+ ATPase inhibitor found in an endotoxin of Leptospira interrogans

We showed previously that the glycolipoprotein fraction prepared from Leptospira interrogans inhibited the Na+,K+ ATPase enzyme purified from brain or kidney and in isolated nephron segments (M. Younes-Ibrahim, P. Burth, M. V. Castro Faria, B. Buffin-Meyer, S. Marsy, C. Barlet-Bas, L. Cheval, and A. Doucet, C. R. Acad. Sci. Paris Ser. III 318:619-625, 1995). In the present communication, we have demonstrated that unsaturated fatty acids such as oleic and palmitoleic acids, which are adsorbed to this fraction, are effective inhibitors of the enzyme.     

Polymorphism of pericentromere heterochromatin of polytene chromosomes of ovarian trophocytes in natural populations of the malaria mosquito Anopheles messeae Fall

The HBsAg status and demographic data of 2480 pregnant women who attended antenatal clinics at Maternal and Child Health Centres in Hong Kong were collected by means of a self-administered questionnaire over a 1-week period in July 1996, to explore the underlying reason of a higher than expected HBsAg prevalence. Local women constituted 49.2% of the sample, mainland Chinese 39.7% and others 11.1%. The overall HBsAg prevalence was 10.0%. When related to place of birth, those born in Hong Kong had a prevalence of 8.4% whereas the prevalence of those born in mainland China was 13.1% (P < 0.001). The overall HBsAg carriage rate is high because of a higher rate in immigrants in the community. It is apparent that the HBsAg prevalence of local people in Hong Kong has been decreasing in the past decade. Overall, the current HBsAg carriage rate in the local adult population is estimated to have declined to about 8%.     

Monoclonal antibodies to the alpha-subunit of the putative human H+,K+-ATPase encoded by the atp1al1 gene

The N-terminal fragment of ATP1AL1, the possible catalytic subunit of human ouabain-sensitive H+,K(+)-ATPase, was expressed in Escherichia coli cells as two recombinant proteins: the Ser14-Ile104 fragment or the same fragment containing His6 sequence at its N-end. The second protein was purified by metal-affinity chromatography and used as an antigen to construct two hybridoma lines producing antibodies of the IgM class. These monoclonal antibodies were shown to recognize not only the starting antigen but also the full-size recombinant ATP1AL1 protein and do not react with Na+,K(+)-ATPase.