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Biomedical subjects

C García-Moreno

Publications and source records attributed to C García-Moreno.

17 recordsLinked to original sources
PubMed2004

Effects of 17beta-estradiol, tamoxifen and raloxifene on the protein and mRNA expression of interleukin-6, transforming growth factor-beta1 and insulin-like growth factor-1 in primary human osteoblast cultures.

We investigated the effects of 17betaestradiol and two selective estrogen receptor modulators, tamoxifen and raloxifene, on the expression and release of constitutive and interleukin-1-stimulated interleukin (IL)-6, transforming growth factor-beta1 (TGF-beta1) and insulin-like growth factor-1 by osteoblasts in primary culture from trabecular bone of healthy post-menopausal women. After 24 h incubation with 10(-8) M concentration of these compounds, there was no decrease in: a) the constitutive or IL-1beta-induced levels of IL-6 protein released to culture medium; b) the constitutive IL-6 mRNA expression after incubation of osteoblasts with 10(-8) M 17betaestradiol or 10(-8) M tamoxifen for 1, 3, 6, 24 or 30 h. Although a decrease after 30 h of treatment with 10(-8) M, raloxifene was found in mRNA IL-6 expression, and this fact was not reflected by a decrease in the release of IL-6 protein to the culture medium after 48 h of incubation with 10(-8) M or 10(-7) M raloxifene. Tumoral growth factorTGF-betal expression was not influenced by incubation with these compounds. Gene expression of IGF-I increased following 24 or 30 h incubation with 10(-8) M 17beta-estradiol and 30 h incubation with raloxifene. Tamoxifen did not affect IGF-I expression. In conclusion, the effects of estradiol or tamoxifen on bone metabolism do not appear to be mediated through the regulation of osteoblast IL-6 release or synthesis, but raloxifene produces a decrease in mRNA IL-6 expression. The actions of estradiol, tamoxifen and raloxifene do not appear to be mediated by tumoral growth factor TGF-beta1. On the other hand, an increase in IGF-I synthesis induced by raloxifene and estradiol could mediate, in part, the effects of these compounds on bone.

Aged↗
PubMed2004

Modulation of survival in osteoblasts from postmenopausal women.

Osteoblast survival is one of the determinants of postmenopausal osteoporosis development. Recent data from animal experiments suggest that cytokines, in particular Fas ligand (FasL), contribute to postmenopausal osteoporosis. We now address the effect of Fas activation in postmenopausal osteoblast survival and the potential modulatory effect of estrogen and raloxifene analog (LY117018). The expression of Fas mRNA, Fas protein, and the sensitivity to Fas-induced apoptosis were studied in primary cultures of human osteoblasts from postmenopausal women and in osteoblastic MG-63 cells. Human postmenopausal osteoblasts constitutively expressed Fas receptors in the cell surface. TNFalpha increased the expression of Fas mRNA and cell surface Fas expression. Neither estradiol nor raloxifene analog prevented this increase in Fas expression. In addition, activation of Fas receptor resulted in apoptosis of postmenopausal osteoblasts. While TNFalpha did not induce human osteoblast apoptosis, it did increase the lethal effect of Fas activation. Therapeutic concentrations of estradiol or raloxifene analog did not modulate lethal cytokine-induced apoptosis. Both postmenopausal osteoblasts and MG-63 cells express FasL. FasL expression was not modulated by TNFalpha. In conclusion, estrogen and raloxifene analog do not appear to affect the sensitivity of postmenopausal osteoblasts to Fas-mediated apoptosis.

Aged↗
PubMed2002

Dilemmas and opportunities for an appropriate health-service response to violence against women.

This article is an overview of the role of health services in secondary and tertiary prevention of intimate partner violence. In it, I review the evidence, which comes mostly from developed countries, on the effectiveness and limitations of in-service training programmes to identify and care for women who have experienced intimate partner violence. I also discuss recent initiatives in developing countries to integrate concerns on gender-based violence into health-care services at different levels, some of the dilemmas and challenges posed by the current approaches to intimate partner violence, and recommendations for future interventions.

Battered Women↗
PubMed2001

S-sulfonate determination and formation in meat products.

A treatment with cyanide for the analysis of S-sulfonates in meat and meat derivatives, after a study of the effectiveness of this agent and that of dithiothreitol (DTT), is proposed. Once the protein-bound sulfite has been released, it is determined by HPLC ion exclusion with electrochemical detection. In the assay on the reproducibility of the method, standard deviations were 7.4, 9.2, and 11.4 for mean S-sulfonate values of 69, 107, and 130 microg of SO(2)/g, respectively. Mean recovery was 91.2% for different amounts (56, 111, and 223 microg of SO(2)/g) of S-sulfocysteine added. A study was made of the formation of S-sulfonates in model systems and in meat from different species-chicken and beef-with different fat contents. In the assays with meat, two different levels of sulfite addition were used: 600 and 1200 microg of SO(2)/g. From the assays carried out in model systems with sulfite and cystine it may be concluded that one factor limiting the interaction is the accessibility to disulfide groups. The proportion of S-sulfonates in sulfited meat remains relatively constant and does not seem to be governed by the meat component, the level of sulfite addition, or the fat content. However, the latter two factors are inversely correlated with the retention of sulfite in the foods analyzed.

Chromatography, High Pressure Liquid↗
PubMed2000

Ethical and methodological issues in conducting research on gender-based violence in Southern Africa.

International experience of carrying out research on violence against women among women who may have experienced such violence and among men who may have been violent has raised a number of ethical issues, which appear in sharp focus. This paper is based on the collective experiences derived from involvement in three large gender-based violence surveys in South Africa and one in Zimbabwe. These are broadly concerned with the safety of researchers and research subjects from violence arising because of the research project, risks of traumatisation of both respondents and researchers as violent experiences are recounted; impact of work on violence as an issue in researchers' own relationships; risks of under-reporting the extent of violence experienced or perpetrated; and the need for research efforts to be followed up in ways beneficial to women experiencing violence, such as increased support, public information, and law and policy changes. This paper discusses how these issues have pertained and been addressed in research on gender-based violence in Southern Africa and consider lessons for this and other sensitive areas of reproductive and sexual health research.

Battered Women↗
PubMed1999

A variation in Bone Alkaline Phosphatase levels that correlates positively with bone loss and normal levels of aminoterminal propeptide of collagen I in girls with anorexia nervosa.

Anorexia nervosa (AN) is a very extended pathology among adolescent girls nowadays. These patients show a high degree of osteopenia; hence, study of their bone remodelling is of great interest. Serum bone alkaline phosphatase (bAP) and aminoterminal propeptide of procollagen I (PINP) provide good sensitivity in the analysis of bone alterations in postmenopausal osteoporosis. The aim of this study was to compare the usefulness of bAP and PINP in the study of bone remodelling in AN, and their possible correlation with the degree of osteopenia in this pathology. In order to help in the interpretation of the results, levels of the beta-isomer of urinary carboxyterminal propeptide of collagen I (beta-CTX) have also been included. Serum bAP (IRMA) Tandem R-Ostase, Hybritech), PINP (RIA, Orion Diagnostica) and CTX (CrossLaps ELISA, Osteometer) were determined in 41 girls with AN, aged 18.5+/-2.2 years (mean+/-SD) and in 31 healthy control women, aged 19+/-2.3 years. Bone mineral density (BMD) in lumbar spine was measured by DEXA in the AN group. We found that 41 of the 43 patients had BMD z-scores under -2. No significant differences were found in the levels of serum bAP nor in PINP and beta-CTX levels between controls and patients, although values in the AN group were highly variable. All the BMD z-score values were negative, and their absolute value correlates positively with bAP (P = 0.0279) and almost with beta-CTX (P = 0.0921) but not with PINP (P = 0.4627). Bone AP correlates with PINP in control girls (P = 0.017), but not in the AN group (P = 0.3573). Patients with AN were divided into three groups according to their levels of bAP: low (I), normal (II) or high (III). Patients with the highest bAP levels also presented the highest increase in bone resorption, according to their beta-CTX levels, and the highest degree of osteopenia. However, values of PINP were similar in the three groups of patients. The bAP/beta-CTX ratios in subgroups I, II and III of AN patients were 0.035, 0.065 and 0.073, a finding that suggests that bAP is not indicating the real degree of bone mineralization in these patients, because it is a contradiction that the formation/resorption ratio should be higher in the patients who have the highest bone loss. These results could suggest that bone loss in AN is produced by an increase in bone resorption (beta-CTX), without variations in bone matrix formation (PINP); bAP levels are a good marker in the follow-up of osteopenia degree, but not a real indicator of bone mineralization, a similar situation to that of osteomalacia.

Adolescent↗
PubMed1998

Low bone density with normal bone turnover in ovariectomized and streptozotocin-induced diabetic rats.

Diabetes and estrogen deficit are known causes of osteopenia, diabetes being associated with a low bone turnover and estrogen deficit with a high bone turnover. In the present work, we studied the effect of combined ovariectomy and diabetes on bone mineral content (BMC) and bone mineral density (BMD) and several bone markers in the rat. Four groups of rats were studied: control (C), ovariectomized (O), diabetic (D), and ovariectomized and diabetic (DO). Twelve weeks after starting the experiments, BMC and BMD of the first six lumbar vertebrae were measured; a bone formation marker (BGP) and a bone resorption marker (free collagen cross-links, PYD) were also analyzed. Diabetic rats showed diminished gain in bone mass, BMC (D: 0.417 +/- 0.028 g, DO: 0.422 +/- 0.020 g) and BMDs (D: 0.171 +/- 0.006 g/cm2, DO: 0.174 +/- 0.006 g/cm2) both being significantly (P < 0.001) lower than those of control (C: BMC 0.727 +/- 0.024 g and BMD 0.258 +/- 0.004 g/cm2) and ovariectomized (O: BMC 0.640 +/- 0.044 g and BMD 0.240 +/- 0.009 g/cm2) groups. Moreover, the BMC and BMD of the C group were significantly (P < 0.05) higher than that of the O group. BGP and PYD levels were significantly (P < 0.01) higher in the O group (BGP: 138.2 +/- 16.8 ng/ml, PYD: 270.2 +/- 17.8 nM/mM) than those found in the control rats (BGP: 44.7 +/- 4.8 ng/ml, PYD: 165.6 +/- 12.5 nM/mM); the D group showed significantly (P < 0.01) lower values (BGP: 27.4 +/- 14.6 ng/ml, PYD: 55.0 +/- 7.4 nM/mM) than those of the control group. The DO group showed similar levels (BGP: 43.4 +/- 5.1 ng/ml, PYD: 146.7 +/- 14.6 nM/mM) to those found in the C group. Although bone marker levels in the O and D groups were in accordance with those expected in these situations, in the DO group the corresponding levels are apparently "normal." Also, the decrease of gain in bone mass observed after combining estrogen deficit and diabetes (DO group) did not seem to be more marked than that caused by diabetes alone.

Amino Acids↗
PubMed1998

Effect of alendronate on cultured normal human osteoblasts.

Alendronate is an aminobisphosphonate with a potent anti-reabsorptive action that does not appear to interfere with bone mineralization, and is even able to increase bone mineral density in osteoporotic postmenopausal women through a still not fully understood mechanism. This study was conducted to assess the direct effect of alendronate on diverse aspects of normal human osteoblast physiology. For that purpose, the in vitro effect of a wide range of concentrations [from 10(-1) to 10(-12) mol/L] of alendronate on cell viability, proliferation, collagen synthesis, and the mineral-depositing capacity of normal human osteoblasts was tested. Alendronate effects were examined at 48 and 96 h of culture in the presence or absence of fetal calf serum. In vitro alendronate affected osteoblast viability at concentrations equal to or higher than 10(-4) mol/L. At concentrations equal to or higher than 10(-3) mol/L, no viable cells were observed in cultures. In vitro alendronate at concentrations between 10(-5) and 10(-12) mol/L did not have any effect on the proliferative capacity of normal human osteoblasts determined by two different techniques: (1) tritiated thymidine incorporation to DNA and (2) cell counting. Collagen synthesis by normal human osteoblasts showed a tendency to decrease following incubation with alendronate supplemented with fetal calf serum. This decrease was only statistically significant after 96 h of culture; however, a dose-response effect could not be documented. Finally, no effect of alendronate was observed on calcium deposition in vitro by normal human osteoblasts at concentrations equal to or lower than 10(-5) mol/L. In conclusion, the present study shows that alendronate in vitro does not affect viability, proliferation, and mineral deposit capacity of normal human osteoblasts at the concentration at which it inhibits by 50% the resorptive capacity of osteoclasts that for this drug has been reported as 2 x 10(-9) mol/L.

Adult↗
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↗
PubMed1983

Improved method for determination and identification of serotonin in foods.

A previously described method to identify and quantitate serotonin in foods has been improved. The extraction and separation of serotonin from interfering substances has been improved, and the scope of material to which the method may be applied has been widened. The relative standard deviation (RSD) for repeated determinations of serotonin in canned fried tomato purée and the average recovery of serotonin added to the same sample was 6.25 and 89.9%, respectively. The method showed the presence of serotonin in apricots, cherries, and peaches.

Chromatography, Thin Layer↗
PubMed1980

Spectrofluorometric determination and thin layer chromatographic identification of serotonin in foods.

A method is described for determining serotonin in foods, based on alkaline butanol-sand column elution followed by spectrofluorometric and spectrofluorometric determination with thin layer chromatographic confirmation. The method has been applied to fresh bananas, banana-based baby food, and fresh and canned tomatoes. The average recovery was 91%. The amounts of serotonin found were 10--30 ppm in bananas, 0.1--1.9 ppm in banana-based baby foods, 4.4--5.6 ppm in fresh tomatoes, and 2.8--5.6 ppm in canned tomatoes.

Chromatography, Thin Layer↗