Isolation, characterization, and molecular cloning of a specific Mycobacterium tuberculosis antigen gene: identification of a species-specific sequence.

A rabbit polyclonal antiserum exhibiting a specific recognition pattern for Mycobacterium tuberculosis proteins was used to screen an M. tuberculosis genomic library constructed in the expression vector lambda gt11. One clone, denominated C1:10, expressed M. tuberculosis-specific determinants as part of a large fusion protein with beta-galactosidase. The gene for this protein has been sequenced, and it encodes a protein of 134 amino acids (13.8 kDa) which did not display significant homology with any of the previously reported proteins in the data bases. Hybridization studies with restriction fragments of the cloned sequence revealed that it was not present in the genomes of related mycobacteria, namely, M. bovis, M. bovis BCG, M. flavescens, M. fortuitum, M. phlei, and M. vaccae. These findings suggest that we have detected a gene, or a fragment therefrom, unique for M. tuberculosis whose nucleotide and amino acid sequences could be useful tools in the design of an improved vaccine or a diagnostic method of greater accuracy for tuberculosis.     

Predictive equation for acquisition of hepatitis B in hospital workers in a general hospital

A cross-sectional study was performed to obtain risk factors for hepatitis B disease, HBsAg carriers and immunised personnel, among 2470 workers in a general hospital in Madrid, Spain. The data obtained were analyzed with multiple logistic regression to obtain coefficients for variables. The results of the analysis show that being a nurse or being regularly exposed to blood are the most important risk factors for hepatitis B acquisition. The length of time working at the same job activity was also a risk factor. The resulting coefficients allow the construction of a predictive equation for non-immunised, HBsAg carrier and immunised HBV status, which can select subjects for a hepatitis B vaccination program.     

Studies on the degenerative and regenerative phenomena occurring after transection and repair of the sciatic nerve in rats: effects of acetyl-L-carnitine

The effects of acetyl-L-carnitine on some degenerative and regenerative phenomena following sciatic nerve transection in rats, were studied. In Experiment 1, acetyl-L-carnitine was administered intraperitoneally at the dose of 50 mg/kg/day for 28 and 56 days following transection and microsurgical repair of the sciatic nerve. On day 56, the acetyl-L-carnitine-treated rats showed a significantly (p less than 0.05) better motor recovery ("clinical assessment") of the peroneal component of the sciatic nerve than the control rats. Twenty-eight days after nerve repair, the acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of myelinated axons in the postlesional nerve stump than control rats. Finally, the treated rats had a significantly lower (p less than 0.05) presence of atrophic fibres in the extensor digitorum longus muscle. In Experiment 2 the sciatic nerve was cut. To prevent spontaneous regeneration, a metallic clip was applied to the distal nerve stump and then the nerve stumps were positioned in different anatomical compartments. After surgery, a group of rats was treated with acetyl-L-carnitine dissolved in the drinking water (75 mg/kg/day). Another group of rats received normal water and served as the control group. Three, 6, 9, 12 and 18 months postoperatively, in the rats of both groups, the proximal sciatic nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. While in untreated rats the number of horseradish peroxidase-labelled neurons decreased with the increase in denervation time, in acetyl-L-carnitine-treated rats the number of horseradish peroxidase-labelled neurons remained stable for as long as 12 months of denervation and decreased only after 18 months of denervation. Furthermore, acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of horseradish peroxidase-labelled neurons with respect to untreated rats both after 9 and 12 months of denervation. In Experiment 3, the sciatic nerve was cut and then repaired after periods of 3, 6, 9, 12, and 18 months. Four months after nerve repair, the sciatic nerve was again cut and the proximal nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. Both acetyl-L-carnitine-treated and untreated rats showed a tendency to have an increased number of horseradish peroxidase-labelled neurons with respect to intact rats of correspondent ages.(ABSTRACT TRUNCATED AT 400 WORDS)     

Androgenic Activity of Antiandrogens Predicted by Fit into DNA

Computer modeling including graphics and energy calculations were employed for the first time to examine the stereochemical fit of antiandrogens into double-stranded DNA. In this study, we assessed the relative fit of antiandrogens in the cavity between base pairs known to accommodate androgens. When compared to testosterone which was given a normalized value of 100%, the antiandrogens manifested the following order of fit: RU23908 (88%) > hydroxyflutamide (71%) > cyproterone acetate (41%). A correlation was observed between the relative fit of the antiandrogens and reported agonistic properties as assessed by the ability to increase nuclear androgen receptor levels in the rat ventral prostate. These findings may be useful in the design and development of androgen antagonists without agonistic activity.     

Cardiac output measurement by the thermodilution method: An in vitro test of accuracy of three commercially available automatic cardiac output computers

Objective To describe the accuracy and the reproducibility of the thermodilution flow measurements obtained using 3 commercially available cardiac output computers commonly used in intensive care units.Design An experimental in vitro study. Twelve different values of control flow (Qctr) were measured (Qmsr) using 3 different cardiac output computers (Abbott Critical Care System, Oximetrix 3 SvO₂/CO Computer, Baxter Oximeter/Cardiac Output Computer SAT-1^TM; American Edwards Laboratories, 9520 A Cardiac Output Computer). Standard equipment and techniques were employed, taking account of the specific weight and heat of warm water relative to blood. In addition, separate sets of measurements were performed in order to investigate the effect on Qmsr of some variables which may influence the indicator loss (time for injection, depth of immersion of the catheter, temperature of the injected fluid).Setting Our laboratory, inside the intensive care unit.Measurements and results The analysis of the linear regression of Qmsr versus Qctr (r values between 0.992 and 0.984; residual standard deviation values comprised between 0.24 and 0.49 l/min; intercepts and slopes not significantly different from identity line), the values of the percentage errors (PE=[Qctr–Qmsr]·100/Qctr; PE mean values 7.9, 5.0 and 13.1), and those of the coefficients of variability (CV=standard deviation mean value, %; CV mean values 5.4, 5.8 and 4.6), show a good level of accuracy and reproducibility of the measurements. Our data confirm previously reported results. Furthermore, the cumulative effect of variables capable of influencing the indicator loss, even if corrected according to the calculation constant the manufacturers provide, was found to result in statistically significant changes of Qmsr.Conclusion The accuracy and reproducibility of the automatic cardiac computers tested is sufficient for practical clinical purpose. It may also depend on the modality of injection of the cooling bolus, which may significantly influence the effective indicator losses.     

Effect of ethylene on naringin, narirutin and nootkatone accumulation in grapefruit

This paper studies the effect of different concentrations of ethephon on the levels of the sesquiterpene, nootkatone, and of the flavanones, naringin and narirutin, in grapefruit fruits. The results show that nootkatone synthesis and/or accumulation was stimulated by all the concentrations of ethephon assayed, while the levels of naringin and narirutin in the rind diminished. These results open up new perspectives concerning the possible regulation of the secondary metabolism of the plants.