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Biomedical subjects

M Revilla

Publications and source records attributed to M Revilla.

At least 55 records · Page 3Linked to original sources
PubMed1997

Comparison of the bone robusticity index and bone weight/bone length index with the results of bone densitometry and bone histomorphometry in experimental studies.

In experimental studies of bone in rats, two morphometric indices reflecting bone density have been proposed, the bone robusticity index and bone weight/bone length index. In rats, the bone mineral content (BMC) and bone mineral density (BMD) of a selected bone can be determined using dual-energy X-ray absorptiometry (DXA); bone volume can be measured by histomorphometry and other techniques. This study was undertaken to compare two morphometric indices (bone robusticity and bone weight/bone length) with the results of DXA and histomorphometry. Forty female Wistar rats (100 days old, mean weight 239+/-12 g) were studied: 20 controls and 20 ovariectomized rats (OVX). The morphometric indices and BMD differed significantly (Friedman test) in the overall group of rats; no differences were observed in the control group, but significant differences were apparent in the OVX group (p<0.0001). The morphometric indices correlated more closely with BMC than with BMD; the femur length/ femur weight index had closer correlations than the robusticity index. Nonetheless, both morphometric indices differed significantly from BMD determined by DXA under abnormal conditions, which makes them unreliable for use in these circumstances.

Absorptiometry, Photon↗
PubMed1996

Bone mass in Parkinson's disease: a study with three methods.

Recent reports suggest the presence of osteopenia in a high percentage of patients with Parkinson's disease (PD). These data contrast with previous reports of our group, perhaps due to the different methods used. We studied bone mass in 52 PD patients (28 males, 24 females) and in 80 age- and sex-matched controls (40 males, 40 females) who had no other disease that could affect bone mass. We measured the totally body bone mineral content (TBBMC) and the ultrasound bone velocity (UBV) of transmission in phalanx, and performed metacarpal radiogrammetry with computerized radiography (CCT). We also measured serum levels of total alkaline phosphatase and tartrate-resistant acid phosphatase, which were significantly increased in PD patients compared with controls (P < 0.0001). TBBMC was significantly lower in males (P < 0.05) and females (P < 0.05) with PD with respect to their controls. CCT did not differ significantly between the study groups. UBV was significantly lower in males with PD (P < 0.005), but similar in female PD and controls. These data suggest that the changes reported in bone mass in PD patients can depend on the sex and the study methods. We only found severe osteopenia in one male (3.6%) and five females (20.8%) with PD according to z-score. Only in women was no relationship found between TBBMC and severity of PD.

Absorptiometry, Photon↗
PubMed1996

Total and regional bone mineral content in Spanish professional ballet dancers.

Total body bone mineral content (TBBMC) and regional bone mineral content (BMC) was measured in the members of the Spanish National Dance Company (15 female, mean age 25.1 +/- 3.8 years, and 15 male, mean age 28.2 +/- 2.1 years) and in 30 controls (15 women, mean age 26.1 +/- 1.8 years, and 15 men, mean age 28.0 +/- 1.5 years). Ca, P, and Mg intake were greater in the group of ballet dancers than in controls analysis of variance (ANOVA, all P < 0.0001). BMC was similar in the group of ballet dancers and controls except in the trunk without pelvis (P < 0.001). Both male and female dancers weighed less than controls (P < 0.05). The BMC of the male dancers was less than that of male controls only in the trunk (P < 0.05) and in the trunk without pelvis (P < 0.005); BMC was lower in female dancers than in female controls only in the arms and in the trunk without pelvis (P < 0.05 and P < 0.005, respectively). TBBMC, adjusted for weight and age, was correlated partially with caloric intake (kcal/day) and with Ca, P, Mg, and Zn intake (g/day), and yielded significant differences between the dancers and controls only in P intake (P < 0.01), and between male dancers and male controls only in caloric intake and in Ca, P, and Zn intake (all P < 0.01, except for Ca, P < 0.05). The lower trunk bone mass observed in the female dancers is a risk factor for eventual osteoporosis.

Absorptiometry, Photon↗
PubMed1996

Changes in the cortical and trabecular bone compartments with different types of menopause measured by peripheral quantitative computed tomography.

Our objective was to study the changes in the bone mineral density of the cortical and trabecular compartments with different types of menopause. A total of 153 normal postmenopausal women (mean age 48 +/- 5 years) were studied. The women were divided into three groups based on mean age at menopause: early menopause (menopause before 43 years), normal menopause (menopause at 44-52 years), and late menopause (menopause after 52 years). The number of years since menopause was similar in all three groups (+/- 5 years). Cortical and trabecular bone mineral density was determined in all the women using peripheral quantitative computed tomography. Our results show that only the trabecular bone mineral density differed significantly among the groups (Kruskal-Wallis: P = 0.0029). The women with early menopause had a lower trabecular bone density than the women with normal and late menopause (P = 0.0019 and P < 0.0001, respectively). Among the women with early menopause, 22 had experienced menopause before the age of 40 and 25 after the age of 40; there were significant differences in trabecular bone mineral density between these two subgroups (P < 0.05). Trabecular bone mineral density, the only variable studied that varied among the groups, correlated significantly with the duration of reproductive life (simple linear regression: r = 0.340, P < 0.0001). In conclusion, these findings emphasize the importance of the duration of reproductive life as a determinant of bone mass in women.

Adult↗
PubMed1996

Prophylaxis of osteoporosis with calcium, estrogens and/or eelcatonin: comparative longitudinal study of bone mass.

OBJECTIVE: To evaluate three different therapeutic regimens for the prevention of osteoporosis in natural and surgical postmenopausal women who had been found to have rapid bone loss in analytical studies. METHODS: A total of 104 naturally or surgically postmenopausal women were studied, and subsequently followed-up during 1 year for avoidance of the influence of seasonal variation on bone mass, a factor overlooked in several studies. They were randomized into four groups of 26 patients each: the untreated control group (mean age 50 +/- 5 years); the hormonal replacement treatment (HRT) group (mean age 48 +/- 6 years), which was treated for 24 days each month with transdermal 17 beta-estradiol, 50 mg/day, together with medroxiprogesterone, 10 mg during 12 days; the calcium group (mean age 50 +/- 4 years), which was treated with elemental calcium, 1 g/day; and the calcitonin group (mean age 50 +/- 5 years), which was treated for 10 days each month with eel calcitonin, 40 IU/day and with elemental calcium, 500 mg/day. Full-body bone densitometry, for measuring total body bone mineral content (TBBMC), was carried out in all the women at baseline and 1 year. TBBMC was corrected for body weight by dividing its value by body weight (TBBMC/W). RESULTS: After 1 year TBBMC/W was lower in every group: -2.14% (P < 0.001) in the control group; -0.14% (P = NS) in the HRT group (P < 0.05 vs. controls); -0.18% (P = NS) in the calcium group (P < 0.05 vs. controls); and -0.06% (P = NS) in the calcitonin group (P < 0.01 vs. controls; P < 0.05 vs. calcium and HRT). CONCLUSIONS: These findings show that all three treatments are effective in the prevention of postmenopausal loss of bone mass.

Absorptiometry, Photon↗
PubMed1996

Correlation of ultrasound bone velocity with dual-energy X-ray bone absorptiometry in rat bone specimens.

RATIONALE AND OBJECTIVES: To investigate bone mass measurements by ultrasound bond velocity (UBV) in bone specimens obtained from experimental animals. METHODS: The authors made UBV measurements in 40 femurs and tibias dissected from Sprague-Dawley rats (14 weeks-old, mean weight 290 g) and compared them with bone densitometric measurements made on the same material using dual-energy x-ray absorptiometry (DXA). RESULTS: The coefficient of variation for UBV measurements, based on values obtained in five femurs and five tibias at different times, was 0.2% and 0.3% respectively. Regression studies yielded a correlation between UBV and bone mineral density in femur of r = 0.87 (P < 0.0001) and with bone mineral content of r = 0.65 (P < 0.0001); in the tibia similar levels of significance were obtained. The correlation between femur weight and UBV was r = 0.51 (P < 0.0005) and with bone mineral content it was r = 0.79 (P < 0.0001). Partial correlation between UBV and femur bone mineral density, with respect to bone weight, was r = 0.68 (P < 0.001), and with femur bone mineral content was r = 0.71 (P < 0.0001). In the tibia measurements were similarly significant. CONCLUSIONS: Measurements of bone mass made with ultrasound transmission velocity are precise correlate well with DXA measurements.

Absorptiometry, Photon↗
PubMed1996

Behavior of bone mass measurements. Dual energy x-ray absorptiometry total body bone mineral content, ultrasound bone velocity, and computed metacarpal radiogrammetry, with age, gonadal status, and weight in healthy women.

RATIONALE AND OBJECTIVES: Bone mass as measured by dual energy x-ray absorptiometry varies with body weight. The authors studied the behavior of bone mass measurements made by ultrasound bone velocity and metacarpal radiogrammetry in relation to body weight. METHODS: Eighty healthy women were studied: 40 post-menopausal and 40 premenopausal (mean age 60 +/- 6 and 38 +/- 8 years, respectively). The authors performed in every subject the following studies: a radiograph of the nondominant hand for metacarpal cortical thickness, a study of the 2nd to 5th proximal phalanges for ultrasound bone velocity, and total bone mineral content by dual energy x-ray absorptiometry. RESULTS: The measurements obtained with the three methods correlated significantly with each other (P < 0.0001). The only parameter related significantly with weight were total bone mineral content (P < 0.0001). In the premenopausal women, age did not correlate with any measurement. In the postmenopausal women, age correlated significantly with the three measured parameters (P < 0.0058 to P < 0.0001). CONCLUSIONS: Weight did not influence ultrasound bone velocity and metacarpal cortical thickness measurements.

Absorptiometry, Photon↗
PubMed1996

New evidence that serum beta(2)-microglobulin behaves as a biological marker of bone remodelling in women.

Having observed that serum beta(2)-microglobulin concentration correlates with serum tartrate-resistant acid phosphatase (TRAP) concentration in postmenopausal osteoporosis, and that metacarpal endosteal diameter is dependent on bone resorption, we correlated the two biochemical parameters with the radiographic parameter to determine if beta(2)-microglobulin behaves like a biological marker of bone remodelling. In 105 women (mean age 68 +/- 4 years) consisting of 60 normal postmenopausal women and 55 osteoporotic postmenopausal women, there was a significant positive correlation between metacarpal endosteal diameter and these two biochemical values (r = 0.66 with beta(2)-microglobulin and r = 0.68 with TRAP in the osteoporotic postmenopausal women; r = 0.48 with beta(2)-microglobulin and r = 0.56 with TRAP in the normal postmenopausal women; P < 0.001 for all comparisons). All three measurements were significantly higher (P < 0.001) in the osteoporotic postmenopausal women than in the normal postmenopausal women. These findings show that serum beta(2)-microglobulin behaves like a biological marker of remodelling.

Acid Phosphatase↗
PubMed1996

Total and regional bone mass in metastatic cancer of the prostate.

OBJECTIVES: Given the discrepancies in the findings of regional bone densitometry in patients with osseous metastases of prostate cancer, we decided to evaluate total and regional bone mineral content in 21 patients with stage D cancer of the prostate. These measurements were compared with those of a group of healthy subjects of similar age (n = 21). METHODS: A full body bone densitometry was carried out in all of the men. Dual energy X-ray absorptiometry was used. RESULTS: There were no differences between groups in the anthropometric variables (Student's t test). There were no differences between groups in the bone mass of the skull and arms, but patients had less bone mass in the trunk and legs (p < 0.05) and in the pelvis (p < 0.0001). Total body bone mineral content and total body bone mineral content corrected for weight also were lower in the patients than in the control group (p < 0.005). CONCLUSION: These results show that patients with prostate cancer and bone metastases have decreased bone mass, possibly because of a predominance of osteolytic over osteoblastic metastases.

Absorptiometry, Photon↗
PubMed1996

Resonance of about-weekly human heart rate rhythm with solar activity change.

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

Adult↗
PubMed1995

Total and regional bone mineral content and fracture rate in postmenopausal osteoporosis treated with salmon calcitonin: a prospective study.

Seventy-two postmenopausal osteoporotic women having more than one nontraumatic vertebral crush fracture were studied. Thirty-six of them, aged 68.8 +/- 1.2 years (18 +/- 4 YSM-years since menopause), were treated with 100 IU/day of salmon calcitonin i.m. plus 500 mg of elemental calcium for 10 days each month. The remaining 36 patients, aged 69.6 +/- 1.4 years (19 +/- 3 YSM), were given only 500 mg of elemental calcium for 10 days each month. All patients underwent clinical and analytical evaluation every 3 months. Radiological evaluation, assessment of vertebral deformities, and metacarpal radiogrammetry were done every 6 months. Densitometric measurements of total and regional bone mass were made every 12 months. At 24 months, the calcitonin group showed a 60% reduction in the number of new fractures and the group receiving only calcium had a 45% increase (P < 0.001). The incidence of vertebral fractures was 0.07 per patient-year in the group treated with calcitonin and 0.45 per patient-year in the group treated with calcium (P < 0.001). At 2 years, the calcitonin group showed a 12% increase in cortical bone mass on metacarpal radiogrammetry, a 16% increase in the axial skeleton on trunk densitometry, a 3.5% increase in total body bone mineral content, a 30.7% increase in pelvic bone mineral content, and a 6.2% increase in arm bone mineral content (all P < 0.001). In the group treated with calcium alone there was a loss of bone mass in every region. These findings suggest that salmon calcitonin is effective in the treatment of osteoporosis and show that it acts on cortical and trabecular bone.

Absorptiometry, Photon↗
PubMed1995

Beta-2-microglobulin in diseases with high bone remodeling.

Beta2-microglobulin has been observed to behave as a biological marker of bone remodeling. We measured beta2-microglobulin and tartrate-resistant acid phosphatase (TRAP), a specific biological marker of bone remodeling, in 225 women: healthy premenopausal controls, healthy postmenopausal control, and patients with diseases characterized by enhanced bone turnover (postmenopausal osteoporosis, primary hyperparathyroidism, primary hyperthyroidism, polyostotic Paget's bone disease), and in other Paget's group before and after calcitonin treatment. Beta2-microglobulin levels differed significantly between the healthy premenopausal women (n = 20) compared with all the other groups. However, beta2-microglobulin levels did not differ significantly between healthy postmenopausal women (n = 38) and patient's with Paget's bone disease (n = 40)(P = 0.5095), or between women with postmenopausal osteoporosis (n = 30) and women with hyperthyroidism (n = 20)(P = 0.7890). TRAP concentrations differed significantly in all the groups paired except for women with Paget's bone disease and women with either hyperparathyroidism or hyperthyroidism (P = 0.5179 and 0.6993, respectively); likewise, TRAP levels did not differ significantly between the women with hyperparathyroidism and those with hypothyroidism (P = 0.7804). After calcitonin treatment, there was a 22% increase in beta2-microglobulin, a 17% decrease in TRAP, and a 39% decrease in alkaline phosphatase, all of which were significant at P < 0.0001. Our findings indicate that serum beta2-microglobulin, like osteocalcin, behaves as a biological marker of remodeling in a number of diseases with enhanced bone remodeling but not in Paget's bone disease.

Acid Phosphatase↗
PubMed1995

Evidence that the loss of bone mass induced by GnRH agonists is not totally recovered.

There is disagreement as to whether the loss of bone mass induced by GnRH agonists is reversible. In part, the differences of opinion might be attributed to the fact that the influence of weight and seasonal changes on bone mass is often overlooked. Taking into consideration weight and seasonal changes in bone mass, total (TBBMC) and regional body bone mineral content were measured in 38 women treated with GnRH agonists for 6 months for endometriosis or leiomyomata. Measurements were made at the onset of treatment, at 6 months of treatment and at 6 months after finishing treatment. TBBMC was corrected for body weight. Body weight had increased significantly at 6 months of treatment (P = 0.0175). Regional bone mineral content showed the following: limbs, no changes; head, significantly lower at 12 months than at baseline (P = 0.0036) and at 6 months (P = 0.0343) of therapy; trunk, significantly lower at 6 months (P = 0.0002) compared to baseline, but the values at 1 year were not significantly different from either the baseline or the 6-month values; pelvis, the same pattern of change as in the trunk (P = 0.0349). TBBMC was significantly lower at 6 months of treatment (P < 0.0001) and at 1 year (P = 0.0162). TBBMC adjusted for weight experienced the same changes as unadjusted bone mineral content (P < 0.0001 and P < 0.0009 at 6 months and 1 year, respectively). Our findings indicate that the bone mass lost with GnRH treatment had not been restored 6 months after discontinuing treatment.

Adult↗
PubMed1995

Correlation of total-body bone mineral content determined by dual-energy X-ray absorptiometry with bone mineral density determined by peripheral quantitative computed tomography.

RATIONALE AND OBJECTIVES: We sought to determine the value of peripheral quantitative computed tomography (pQCT) in measuring bone mineral density. METHODS: In 50 healthy, eugonodal premenopausal women, we correlated measurements of total bone mineral content (BMCTB), made with dual-energy X-ray absorptiometry (DXA), and bone mineral density, determined by pQCT. RESULTS: The partial correlations, adjusted for weight and age, between BMCTB and cortical bone density, total bone density, and trabecular bone density were .71 (p < .0001), .63 (p < .0001), and .32 (p < .05), respectively. CONCLUSION: These results and the advantages of pQCT--providing precise bone density determinations for trabecular and compact bone separately, having a high spatial resolution that allows a "compartmental" analysis of bone structure, having a low coefficient of variation, and having a minimal radiation dose (< 5 mrem)--confirm the adequacy of using this method for bone mass studies.

Absorptiometry, Photon↗
PubMed1995

Zinc, biochemical markers of nutrition, and type I osteoporosis.

Having observed previously that the reduction of levels of biological markers of nutrition in postmenopausal osteoporosis may be related to zinc deficiency, we measured plasma and urinary zinc concentrations in 30 women with postmenopausal osteoporosis and in 30 healthy postmenopausal women who served as controls. Plasma zinc levels did not differ between groups, but urinary zinc excretion was significantly higher in the women with postmenopausal osteoporosis (p = 0.002). The relation between total body bone mineral content corrected for body weight (TBBMC/W) and markers of nutrition was significant (multiple regression analysis: p < 0.0001) in the women with postmenopausal osteoporosis but not in the healthy postmenopausal controls. Likewise, the relation between TBBMC/W and plasma and urinary zinc levels also was significant in the women with postmenopausal osteoporosis but not in the controls (multiple regression analysis: p = 0.0022). Neither group showed any correlation between plasma or urinary zinc concentrations and levels of biological markers of nutrition. Urinary zinc concentration correlated significantly with serum tartrate-resistant acid phosphatase level (simple linear regression analysis: r = 0.583, p < 0.001) in the women with postmenopausal osteoporosis but not in controls. TBBMC correlated with urinary zinc concentration significantly in the women with postmenopausal osteoporosis (simple linear regression: r = 0.567, p = 0.0015), but the correlation was nonsignificant in healthy postmenopausal controls. These findings indicate that the elevation of urinary zinc elimination in osteoporosis is dependent on bone resorption.

Aged↗
PubMed1995

Evaluation of bone density with peripheral quantitative computed tomography in healthy premenopausal, perimenopausal, and postmenopausal women.

We compared bone mass in premenopausal, perimenopausal, and postmenopausal women using peripheral quantitative computed tomography to measure separately cortical, trabecular, and total bone density. Trabecular bone density was lower (p < 0.05) in the perimenopausal women than in the healthy premenopausal women. In perimenopausal women, trabecular bone density showed a significant linear regression with age (r = 0.554, p < 0.001), but cortical bone density did not (r = 0.130, p = 0.447). The group of postmenopausal women had significantly lower bone mass in all three bone compartments than the premenopausal and perimenopausal women. These findings confirm the existence of a significant loss of trabecular bone mass in the perimenopausal period.

Adult↗
PubMed1995

Biochemical markers of nutrition in type-I and type-II osteoporosis.

We studied nutritional deficits, using as markers the levels of transferrin, retinol-binding protein, and prealbumin, in 20 women with osteoporotic hip fractures (type II), 40 women with vertebral fractures (type I), and two groups of age-matched control subjects. The concentrations of all three nutritional markers were lower in the two groups of patients than in their matched controls, and in type-I as compared with type-II osteoporosis. In the osteoporotic patients, simple linear regression showed a significant correlation between the variables which we studied (r2 ranged from 0.5 to 0.7; p < 0.001), the best correlation being between prealbumin and retinol-binding protein in type-II osteoporosis. Our results suggest that there is a more marked nutritional deficit in type-II than in type-I osteoporosis.

Aged↗