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Biomedical subjects

J del Pino

Publications and source records attributed to J del Pino.

5 recordsLinked to original sources
PubMed1995

Heterogeneous decrease of bone mineral density in the vertebral column of ovariectomized rats.

The long-term effect of ovariectomy on the loss of bone mineral density (BMD) was evaluated in rats with and without estrogen treatment; BMD was studied in the lumbar and caudal vertebrae, measured by DXA, to find how the losses of BMD occur in the axial skeleton. Seventy female Wistar rats of 3 months of age were divided into four groups as follows: group 1: control animals; group 2: ovariectomized animals; group 3: ovariectomized animals undergoing treatment with estrogen (0.25 mg/kg per week of 17-beta estradiol); group 4: ovariectomized rats undergoing estrogen treatment only during the last 3 months of the experimental period. No significant differences were found among the groups in regard to the BMD values of the caudal vertebrae at either 3 or 6 months. Likewise, in the lumbar vertebrae there were no significant differences among the groups after 3 months. However, at 6 months, a decrease in the BMDs of the ovariectomized animals with respect to the remaining groups was found: 226 +/- 11 mg/cm2 in the ovariectomized group; 262 +/- 14 mg/cm2 in the controls; 255 +/- 4 mg/cm2 in the rats receiving estrogen treatment for 6 months; and 259 +/- 5 mg/cm2 in the animals receiving estrogen for 3 months. The study also reveals the absence of differences in the bone mineral density between the ovariectomized and control rats when the former received estrogen treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1991

Potentiation of cocaine hepatotoxicity by ethanol in human hepatocytes.

The hepatotoxic effects of cocaine on the human liver and the effect of ethanol on cocaine-induced hepatotoxicity have been examined in adult human hepatocytes cultured in chemically defined conditions. Cultures were exposed to concentrations of cocaine ranging from 10(-2) to 10(-5) M. Cytotoxicity was evaluated after 24 hr of continuous exposure to cocaine by measuring the leakage of intracellular LDH and the ability of cells to reduce MTT. According to these end-point parameters, half-maximal cytotoxic concentrations of cocaine for human hepatocytes (IC50) were 6.8 and 7.8 mM, respectively. Lower concentrations of cocaine, however, impaired basic metabolic functions of human hepatocytes. Exposure of cells to 2 mM cocaine for 24 hr resulted in a 50% decrease in hepatic glycogen, a 40% decrease in cellular glutathione content, and a 40% decrease in urea synthesis with respect to control values. For most of the metabolic parameters assayed, significant alterations were observed at 0.5 mM cocaine. Glycogen reloading of hepatocytes began to be inhibited in the presence of 0.60 mM cocaine (IC10). Ethanol greatly potentiated cocaine-induced hepatotoxicity. After a 48 hr pretreatment of human hepatocytes with 50 mM ethanol, low concentration of cocaine (0.25 mM) that had no effects on hepatocyte metabolism in the absence of ethanol caused a 20% inhibition of the urea synthesis rate, a 40% degradation of glycogen stores, and a 30% reduction in glutathione content. The results of our work show that ethanol increases the effects of cocaine on human hepatocytes by a factor of 10.

Cells, Cultured↗
PubMed1990

Influence of sex, age, and menopause in serum osteocalcin (BGP) levels.

Osteocalcin (bone Gla protein) is a promising marker of bone turnover useful in the diagnosis and follow-up of high turnover osteoporosis. Conflicting results have been reported about its physiological variations according to sex, age, and menopause. Several, but not all, authors have found increased levels in males, with aging, and after menopause. We measured serum osteocalcin in 126 healthy subjects, 57 males and 69 females, aged between 45 and 88 years. Osteocalcin was higher (P less than 0.01) in males (6.24 +/- 0.36) than in females (4.32 +/- 0.34). This sexual difference was significant, too, in subjects younger and older than 60 years. Osteocalcin increased with age, linearly in males (P less than 0.05), and exponentially in females (P less than 0.05). Although there was a difference in age (P less than 0.05), no difference in osteocalcin levels between premenopausal women and women in their first two postmenopausal years was detected, while osteocalcin was significantly increased in women more than two years into menopause. We conclude that osteocalcin in healthy subjects is higher in males than in females and increases with age after 45 years in both sexes. Osteocalcin levels increase in women more than two years beyond menopause, but not only as an effect on aging.

Age Factors↗