Biomedical subjects

C Montenegro

Publications and source records attributed to C Montenegro.

4 recordsLinked to original sources

PubMed2005

Temporal variation of chemical composition and relaxant action of the essential oil of Ocimum gratissimum L. (Labiatae) on guinea-pig ileum.

The medicinal plant Ocimum gratissimum L. (Labiatae) is widely encountered in the Northeast of Brasil where it is used to treat digestive problems. Its leaves have an essential oil (EOOG) content whose chemical composition varies according to the time of plant collection. We have compared the effects of the EOOG, collected at 08:00 a.m. (EOOG8) and at 12:00 a.m. (EOOG12), on the relaxation of guinea-pig isolated ileum. Both EOOG8 and EOOG12 (30-300 microg/ml) reversibly relaxed the spontaneous tonus of the guinea-pig ileum in a concentration-dependent manner, with similar IC50 values (49.3 and 23.8 microg/ml, respectively). The magnitude of the decrease in resting tonus was similar to that of the recognised smooth muscle relaxant papaverine. EOOG8 and EOOG12 relaxed 60 mM KCl-precontracted preparations similarly (38.33 +/- 9.91 microg/ml and 35.53 +/- 6.70), whereas a significantly more potent relaxant effect of EOOG12 compared to EOOG8 was observed when tissues were contracted using 10 microM acetylcholine (IC50 values of 69.55 +/- 4.93 and 128.16 +/- 15.70 microg/ml, respectively; p < 0.05). The principal constituents of the essential oil, eugenol and cineole, also relaxed KCl-precontracted preparations, although they were less potent than EOOG, suggesting that they alone were not responsible for EOOG-induced relaxations. Our results show that the essential oil extracted from the leaves of O. gratissimum L., collected at different time periods, exerts significant relaxant effects on isolated guinea-pig ileum which may underlie the therapeutic action of the plant.

Animals↗

PubMed2000

Recombinant growth hormone delivery systems based on vinylpyrrolidone-hydroxyethyl methacrylate copolymer matrices: monitoring optimization by capillary zone electrophoresis.

Experimental conditions for the fabrication of two new polymeric devices (i.e. films and slabs) useful for the controlled release of recombinant growth hormone (GH) are given. The release rate is controlled by the resorption profile of the vinylpyrrolidone-hydroxyethyl methacrylate (VP-HEMA) tested systems which is related to the copolymer composition. The suitability of capillary electrophoresis (CE) for following the complete preparation of the different VP-HEMA devices is shown. Moreover, CE allows simultaneous monitoring of the controlled release of GH and dissolved polymer during in vitro experiments. From these results, guidelines are given for the fabrication of polymeric devices containing protein as active drug as well as for the correct selection of conditions during in vitro experiments.

Biocompatible Materials↗

PubMed1996

[Our experience in endourology].

Exposition of the experience accrued over 8 years in endo-urological procedures performed to 303 patients divided in 2 groups: Lithiasic (Group I) and Non-lithiasic (Group II) patients. Ninety-two (92) percutaneous nephrostomies in 69 patients and 235 ureteroscopies in 234 patients were accomplished, removing 324 calculi and resolving other obstructive conditions. The rate of success was 85% and 98% for the percutaneous nephrostomies and ureteroscopies, respectively. Complications were reported in 7 patients after percutaneous nephrostomy and in 14 patients during ureteroscopy. Most of these complications resolved with the use of endoscopic techniques except in two patients who required open surgery. There were no deaths in the present series. The advantages of applying this technique over the conventional one are discussed.

Adult↗

PubMedDate not supplied

[Tuberculin reaction in healthy infants vaccinated with BCG at birth].

Tuberculin test with PPD RT-23 with Tween 80 (2 TU strength), was performed to 228 infants under two years of age. None of them had any history of contact with tuberculosis. All were healthy, well-nourished infants, and had been vaccinated with BCG at birth. A positive PPD reaction (greater than 6 mm), was found only in 8.8%, of them and 16.2% had no BCG scar on examination; 14.9% of the studied infants had negative PPD (0-5 mm) reactions together with absent BCG scars. These findings are significantly different from those previously reported by chilean authors, which showed higher proportion of positive (greater than = 6 mm) reaction to 2 TU PPD in infants from similar populations that had been vaccinated with different BCG preparations than our patients. These results suggest the need to evaluate the efficacy of the BCG vaccines that are currently being used in our country to determine the factors that may affect it and the protection that they afford.

BCG Vaccine↗