Search PubMedSearch

Biomedical subjects

M Arenas

Publications and source records attributed to M Arenas.

33 records · Page 2Linked to original sources

Influence of postmortem time and temperature on osteoinductive activity of demineralized microperforated ethylene oxide-sterilized syngeneic bone implant in the rat.

Bone morphogenetic protein is labile and easily inactivated by many extracorporeal factors. It is crucial to establish whether delay in retrieval of donor bone and ambient holding temperature of the donor body influence osteoinductivity of bone left in situ. Of ten adult rats that were killed, five were kept at 4 degrees and five at room temperature. Femurs were harvested at 24, 36, 48, 72, and 168 hours. After processing, segments were implanted in 20 four-week-old syngeneic rats for 14 days. The level of osteoinduction was evaluated histologically. It was excellent in the 4 degrees group in the 24-, 36-, and 48-hour specimens but less advanced at 72 hours. Bone taken from the room temperature group showed findings identical to those kept at 4 degrees through 36 hours, but osteoinduction was less advanced at 48 hours and absent at 72 hours. No bone formed at 168 hours in either temperature group. The following observations were made. (1) Osteoinductivity of demineralized bone left in situ after death was unexpectedly stable. (2) Retrieval time was extended by donor cooling. (3) Microperforated demineralized bone actively induced new bone formation. (4) Ethylene oxide does not inhibit osteoinduction when correctly applied for sterilization. If confirmed in humans, retrieval of bone to be used for osteoinduction could be delayed for some hours, particularly if the donor was immediately refrigerated. This would increase the effective number of bone tissue donors and utilize an undeveloped resource.

Animals

Menstrual patterns and progesterone circulating levels following different procedures of tubal occlusion.

This study was undertaken to assess the effects of different tubal occlusion procedures on ovarian function. Three groups of subjects randomized to tubal occlusion by laparoscopy and Yoon ring (24 subjects), minilaparotomy and Yoon ring (19 subjects) and minilaparotomy and Pomeroy (22 subjects), and one separate control group of 26 healthy subjects not using any form of contraception were studied in a prospective design. The characteristics of the menstrual patterns were studied for one year after sterilization. Determination of the circulating progesterone levels were made on days 15, 20 and 25 of menstrual cycles initiated 1, 3, 6 and 12 months following the tubal ligation. In the analysis of the bleeding pattern there was a statistically significant difference in the mean segment length and in the longest bleeding-free interval in the subjects who had been sterilized by minilaparotomy with Yoon ring, when compared to the other two study groups and to the control group. However, the magnitude of this difference in number of days was not considered clinically significant. There was no statistically significant difference in the percentage of ovulatory cycles within the study and the control groups, or when the results of the study groups were compared with each other or to the control group.

Adult

Effect of diltiazem on pentagastrin-induced gastric secretion in man.

The effects of diltiazem on pentagastrin-induced gastric secretion were studied in 11 normal volunteers. Diltiazem 60 mg thrice daily for 10 doses did not produce any clear-cut effect on the increase in gastric acidity induced by either standard or low doses of pentagastrin. Despite the role of calcium on gastric secretion, diltiazem does not show promise as an agent capable of reducing gastric acidity.

Adult

[Pulmonary abscess].

Explore the source record for details and available documents.

Anti-Bacterial Agents