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)     

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.     

Olfactory esthesioneuroblastoma: scintigraphic expression of somatostatin receptors

Esthesioneuroblastoma is an uncommon tumor originating in the upper nasal cavity and constitutes 3% of all intranasal neoplasms. Few references exist about the expression of somatostatin receptors in these tumors. Our case demonstrates a good correlation between the somatostatin receptor scintigraphy and magnetic resonance imaging.     

Endoscopic retrograde stenting for allograft hydronephrosis

BACKGROUND AND OBJECTIVES: Ureteral obstruction occurs in 2% to 10% of all renal transplant recipients. Antegrade endourologic intervention has been the gold standard of therapy but carries significant morbidity. This study was designed to investigate the feasibility of retrograde stenting of these difficult ureters and to determine whether it can be performed with minimal morbidity without general or regional anesthesia. METHODS: Ninety-seven consecutive patients were found to have renal allograft hydronephrosis by ultrasonography, between August 1993 and March 1997. Of these, 61 (63%) had confirmation of obstruction by MAG-3 imaging, with equivocal results in 25 (26%). The remaining 11 patients had a rising creatinine concentration despite Foley catheter drainage. All patients had retrograde stenting attempted under local anesthesia followed by intravenous sedation if necessary. If stent placement was unsuccessful, the procedure was repeated under regional or general anesthesia. RESULTS: A total of 85 patients (88%) were managed successfully with retrograde stenting. Of these procedures, 24 (28%) were performed under local anesthesia alone, while 57 (67%) required both local anesthesia and intravenous sedation. Only 4 patients (5%) required general anesthesia. No patient suffered any morbidity associated with retrograde stenting. Of the 12 patients in whom retrograde stenting failed, 2 had renal allograft rupture and 10 had ureteral necrosis at surgical exploration. CONCLUSIONS: Retrograde stenting of the hydronephrotic renal allograft can be achieved with a high success rate and minimal morbidity, usually without general or regional anesthesia. If the ureter cannot be managed in a retrograde fashion, a high index of suspicion for a serious allograft complication should exist.     

Pharmacokinetics and pharmacodynamics of L-Dopa after acute and 6-week tolcapone administration in patients with Parkinson's disease

Tolcapone, a central and peripheral catechol O-methyltransferase (COMT) inhibitor, reduces the conversion of L-Dopa into 3-O-methyl-Dopa (3-OMD), thus leading to more stable and sustained L-Dopa plasma levels. This study was designed to evaluate the effects of acute and 6-week tolcapone administration on L-Dopa pharmacokinetics and pharmacodynamics in Parkinson's disease (PD) patients with predictable motor fluctuations. Tapping test, walking time, and tremor, as well as L-Dopa and 3-OMD plasma levels, were assessed before and for 5 hours after the administration of a single L-Dopa dose, alone or in combination with 200 mg tolcapone, in seven patients with PD. This clinical and pharmacokinetic study was repeated after 6 weeks of tolcapone therapy (200 mg three times daily). It was observed that tolcapone, after both acute and chronic administration, prolonged the motor improvement induced by L-Dopa. As a result, at week 6 of tolcapone therapy, the daily hours spent "off" were significantly decreased. Tolcapone significantly increased the area under the curve of L-Dopa plasma levels by slowing down the elimination of L-Dopa from plasma, whereas the maximal concentration of L-Dopa was not modified. 3-OMD levels decreased significantly after acute tolcapone administration, and after 6 weeks of tolcapone therapy, they were approximately one sixth of pre-tolcapone values. The data confirm that tolcapone decreases L-Dopa clearance and prolongs motor response in PD patients with motor fluctuations, and that this effect is maintained after 6 weeks of tolcapone therapy.