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Biomedical subjects

M Revilla

Publications and source records attributed to M Revilla.

At least 19 recordsLinked to original sources

Transient dissociation of bone metabolism induced by high performance exercise: a study in elite marathon runners.

Bone metabolism parameters were studied in 18 elite marathon runners (11 men and 7 women) who participated in the Marathon World Cup held at San Sebastian, Spain in 1993. Measurements were made before the race, immediately after the race, and 24 hours after the race. The most interesting finding was increased alkaline phosphatase (P < 0. 0001) and decreased tartrate-resistant acid phosphatase (P = 0.0035), which suggests that exercise produced uncoupling of the bone cell metabolism. Serum calcium corrected for proteins did not increase with exercise and at the end of the race there was a negative correlation between cortisol, which was significantly higher (P < 0. 0001), and corrected serum calcium (r = 0.53, P = 0.026) that was not present at baseline. Running time showed a significant negative correlation with baseline serum cortisol (r = -0.67, P = 0.0015) and a significant positive correlation with body mass index (r = 0.53, P = 0.0207). The increase in alkaline phosphatase persisted 24 hours after the race, which suggests that exercise produced an intense and sustained effect on osteogenic capacity.

Acid Phosphatase

Effects of alprazolam supplementation on vertebral and femoral bone mass in rats on strenuous treadmill training exercise.

The ability of alprazolam to diminish cortisol response and favor ovarian function could make it useful in the prevention of osteopenia in athletes in selected cases. A sample of 45 female Wistar rats, all 93 days old and with a mean initial weight of 267 +/- 17 g, were studied. Rats were exposed to a high-performance level of exercise and were divided into two groups-one group received an alprazolam supplement and one did not-and compared with controls to determine the effect of alprazolam on bone mass as measured by dual-energy X-ray absorptiometry (DKA). Exercise consisted of treadmill running on 5 out of 7 days during a period of 11 weeks. A steep grade treadmill inclination was used to stimulate high-intensity muscle activity. Final inclination was 17.5 degrees and treadmill speed was 45 cm/second. Upon completion of the experiment, all the rats were killed and the femur and 5th lumbar vertebra were dissected and cleaned. Length, weight, bone mineral content (BMC), and density (BMD) of the whole right femur and 5th lumbar vertebra were measured. In the exercise only group (no alprazolam), the length, weight, BMC, BMD, and femur BMC/final rat weight ratio of the femur, and the vertebral weight, vertebral BMD and BMC, and vertebral BMC/final rat weight ratio were lower than in the control and the exercise-alprazolam groups (P < 0.0167 - < 0.0001). Alprazolam preserves bone mass in rats exposed to intense exercise.

Absorptiometry, Photon

Effects of promethazine on bone mass and on bone remodeling in ovariectomized rats: A morphometric, densitometric, and histomorphometric experimental study.

The effect of promethazine on bone is debated. We studied the effect of promethazine on bone and the mechanism of action involved by densitometric and histomorphometric measurements in female Wistar rats (100 days old, mean weight 25 +/- 20 g). A control group of 15 rats was not manipulated. An experimental group of 15 rats were ovariectomized (OVX) at 100 days of life and fed a diet supplemented with 4.8 mg/kg promethazine hydrochloride (OVX + Prom). The group that underwent OVX and a group of 15 rats that underwent sham ovariectomy (Sham-OVX) were not treated with promethazine. After 30 days, all the rats were killed. Their femur and 5th lumbar vertebra were dissected and cleaned of soft tissue. Femoral length and vertebral height were measured with a caliper and bones were weighed on a precision balance. The bone mineral content (BMC) and bone mineral density (BMD) of the whole right femurs and 5th lumbar vertebras were measured by dual-energy X-ray absorptiometry (DXA). Trabecular bone volume (Cn-BV-TV%), trabecular number (Tb-N mm(-1)), trabecular thickness (Tb-Th microm), and trabecular separation (Tb-Sp microm) were measured in the femurs by histomorphometric study of nondecalcified bone. Our results showed that promethazine significantly inhibited postovariectomy loss of bone mass (P < 0. 0001) by significantly reducing bone resorption, as shown by the smaller trabecular spaces observed in the treated OVX rats (P < 0. 0001).

Animals

Effect of induced uterine retroversion on bone mass in rats.

OBJECTIVE: To evaluate the effect of surgical uterine retroversion on bone mass in rats. STUDY DESIGN: Forty-five female Wistar rats were assigned randomly to three groups: 15 unmanipulated rats, 15 rats that underwent uterine retroversion, and 15 rats that underwent sham uterine retroversion (exposure of the uterus to air followed by closure of the abdominal cavity). Sixty days later the rats were killed and their femurs were dissected. Femurs were weighed and measured, and femoral bone mineral content (BMC) and bone mineral density (BMD) were determined by dual energy X-ray absorptiometry. RESULTS: In the group of rats that underwent uterine retroversion, BMC, BMD, and BMC corrected for final body weight were significantly lower (P<0.001) than in the unmanipulated control and sham uterine retroversion groups. CONCLUSION: Our findings indicate that uterine retroversion induced a loss of bone mass. We could not determine the mechanism of bone loss; in our opinion, these problem merits further investigations, which currently occupy our interest.

Absorptiometry, Photon

Changes in body composition in women treated with gonadotropin-releasing hormone agonists.

OBJECTIVE: The changes that agonists of gonadotropin-releasing hormone (GnRH) produce in mineral bone mass are known, but, as far as we know, those produced by these agents in other body compartments are unknown. METHODS: We studied these changes using dual-energy X-ray absorptiometry in 50 eugonadal women treated with decapeptyl (Triptoreline), 3.75 mg injected intramuscularly, at 28-day intervals for 6 months. RESULTS: There were significant increases in fat content (9.5%, P < 0.0005) and weight (1.3%, P < 0.01), and significant decreases in fat-free mass (-1.9%, P < 0.0001) and water content (-1.8%, P < 0.0002). Bone mass was lost in the axial skeleton (-3.6%, P < 0.0001) but not in the peripheral skeleton. CONCLUSIONS: The changes induced in body composition by the GnRH agonists are similar to those of natural menopause.

Absorptiometry, Photon

T score of trabecular and cortical bone in normal postmenopausal women.

OBJECTIVE: The T score of the cortical and trabecular bone compartments (T score of BMDTrab and T score of BMDCorti) was calculated in healthy postmenopausal women to determine which bone compartment loses more bone mass. MATERIAL AND METHODS: A total 134 healthy postmenopausal women (mean age 55.1 +/- 6.4 years) and 67 healthy premenopausal women (mean age 36.0 +/- 8.6 years) were studied. Determinations were made using peripheral quantitative computed tomography (pQCT) of the nondominant forearm. The postmenopausal women were divided into groups by years since menopause (YSM): two early postmenopausal groups: < 5 YSM and 6-10 YSM; and two late postmenopausal groups: 11-20 YSM and > 20 YSM. RESULTS: There was a significant correlation between the T score of BMDTrab and the T score of BMDCorti (P < 0.0001). Both correlated negatively and significantly with age (P < 0.001 and P < 0.0001, respectively) and neither correlated with weight. The Wilcoxon test showed no significant differences between the trabecular and cortical T scores in the overall group of women. By YSM, only the > 20 YSM group showed significant differences (P < 0.005). The ANOVA post hoc Bonferroni/Dunn test showed a significant difference in the T score of BMDTrab by YSM only in the < 5 YSM versus 11-20 YSM groups (P = 0.007) and in the < 5 YSM versus > 20 YSM groups (P < 0.0001). The T score of BMDCorti by YSM differed significantly only between the < 5 YSM versus 11-20 YSM groups (P < 0.0001) and between the 11-20 YSM and > 20 YSM groups (P < 0.005). CONCLUSION: In contrast with what has been postulated in recent studies, our results showed that postmenopausal bone loss was similar in the cortical and trabecular bone compartments in the first 20 years after menopause. Trabecular bone loss was greater than cortical bone loss in late menopause (> 20 years).

Adult

Total and regional bone mass and biochemical markers of bone remodeling in metastatic prostate cancer.

BACKGROUND: The osteolytic activity of metastases of prostate cancer was evaluated in relation to total body bone mineral content (TBBMC) and regional bone mineral content (RBMC). METHODS: Bone mass was determined by dual-energy X-ray absorptiometry (DXA). Tartrate-resistant acid phosphatase (TRAP) was measured as a biochemical marker of bone resorption. RESULTS: In 32 patients (mean age 72+/-4 years) compared with 32 controls (mean age 73+/-5 years), there were significant differences in TRAP (P < 0.0001), TBBMC (P < 0.0001), and RBMC in the pelvis (P < 0.0001), legs (P=0.0001), and trunk (P<0.05), but not in the arms and head (P=ns). In the overall group of subjects, the correlation between TBBMC and TRAP was r=-0.68, P < 0.0001. The correlations remained significant in the patient and control groups separately. CONCLUSIONS: The loss of bone mass observed in patients with metastatic prostate cancer was caused mainly by the predominance of bone resorption in the osteoblastic metastases.

Absorptiometry, Photon

Metacarpal radiogrammetry by computed radiography in postmenopausal women with Colles' fracture and vertebral crush fracture syndrome.

Based on the hypothesis that the underlying osteoporotic mechanism of Colles' fracture in postmenopausal women is similar to that of other osteoporotic fractures, that is, cortical bone resorption as opposed to cancellous bone resorption, the rate of corticoendosteal bone loss was compared in 40 normal postmenopausal women [average age 68.4 +/- 7.1 years; 20 +/- 4 years since menopause (YSM)], in 35 postmenopausal women with Colles' fracture (age 69.4 +/- 7.5 years, 22 +/- 8 YSM), in 35 normal postmenopausal women with vertebral crush fracture (age 69.4 +/- 7.5 years, 22 +/- 8 YSM, and in 35 normal premenopausal women (age 36.1 +/- 7.9 years). Radiogrammetry by digital radiography of the second metacarpal was used to measure external (ED) and internal (ID) diameter, cortical thickness (CCT), cortical area (CA), and the ratio of cortical area to total area (CA/TA). The ID values of the groups of postmenopausal women were subtracted from the ID value of the premenopausal women and the result was divided by YSM to obtain the rate of corticoendosteal resorption/year (DeltaC), CA resorption year (DeltaCA) and CA/TA resorption/year (DeltaCA/TA). ID, DeltaC, DeltaCA, and DeltaCA/TA all were larger in the postmenopausal women with Colles' and vertebral crush fractures than in the normal postmenopausal women (ANOVA: all P < 0.0001). ID, CCT, DeltaC, CA, DeltaCA, and DeltaCA/TA did not differ between the two groups of postmenopausal women with fractures. DeltaC was 87% greater in postmenopausal women with vertebral crush fracture and 116% greater in women with Colles' fracture than in normal postmenopausal women. These results indicate that the loss of cortical bone is an important factor in Colles' fracture in postmenopausal women.

Adult

Ultrasonographic bone velocity in pregnancy: a longitudinal study.

OBJECTIVE: Longitudinal changes in bone mass were evaluated with use of ultrasonography and bone remodeling markers in 40 normal pregnant women in relation to their calcium intake. STUDY DESIGN: The study took place at the University of Alcalá Hospital in Madrid. Biochemical markers of bone remodeling and ultrasonographic bone propagation velocity in the proximal phalanxes of fingers 2 to 5 were measured in all three trimesters of pregnancy. Wilcoxon, unpaired and paired t tests, and analysis of variance were used. RESULTS: Ultrasonographic bone propagation velocity (meters per second) was lower in the second and third trimesters of pregnancy (p < 0.0001) compared with the respective preceding trimesters and in the third trimester in the overall group of pregnant women. Tartrate-resistant acid phosphatase and alkaline phosphatase levels increased significantly (p < 0.0001) in parallel with the ultrasonographic bone propagation velocity decrease. CONCLUSIONS: Gestation was accompanied by a reduction in ultrasonographic bone propagation velocity that was greater in women with low calcium intake.

Acid Phosphatase

Effects of zinc supplementation on vertebral and femoral bone mass in rats on strenuous treadmill training exercise.

The hypothesis that a zinc (Zn) deficit may cause osteopenia in athletes is well founded. In rats exposed to strenuous exercise, we evaluated the effect of a zinc supplement on femoral and vertebral bone mass determined by dual-energy X-ray absorptiometry. Four lots of 93-day-old female Wistar rats were studied. A control group of 30 rats were not manipulated (Zn- Ex- group). The experimental group of 40 rats was fed a diet supplemented with an additional 20% of Zn/kg of feed; this group was divided into two groups of 20 rats each, one that did not exercise (Zn+ Ex-) and one that did (Zn+ Ex+). A group of 15 rats exercised but did not receive a zinc supplement (Zn- Ex+ group). Training consisted of treadmill running for 5 out of 7 days over an 11-week period. Initial speed, running time, and treadmill speed were increased gradually. Analysis of variance with the Bonferroni/Dunn test showed that the length, weight, bone mineral content (BMC), and bone mineral density (BMD) of the femur were less in the Zn- Ex+ group than in the others (p < 0.008), and the weight, BMC, and BMD of the fifth lumbar vertebra also were lower in the Zn- Ex+ group than in the others (p < 0.008). These findings confirm the adverse effects of strenuous exercise (treadmill running) on bone tissue in rats and the effectiveness of zinc supplementation in preventing it.

Absorptiometry, Photon

Effect of lead on bone and cartilage in sexually mature rats: a morphometric and histomorphometry study.

The effect of exposure to lead on the longitudinal development of the femur and of its cartilage growth plate was studied in rats. A group of forty-five 50-day-old female Wistar rats was divided into a control group of 20 rats and an experimental group of 25 rats fed a diet supplemented with 17 mg of lead acetate per kilogram of feed for 50 days. On Day 50 all rats were killed and their right femurs were dissected. The femurs were cleaned of soft tissue and femoral lengths were measured with a Vernier caliper and thickness of growth cartilage (GPC-Th micron) by histomorphometry. Final body weights were significantly (P < 0.05) lower in the control group than in the rats given the lead-supplemented diet. Femur length did not differ between groups. Histomorphometry of the femur showed that the thickness of growth cartilage was higher (P < 0.05) in the control group. These findings suggested lead-induced inhibition of growth plate development. The growth plate may be one of the key target tissues accounting for the adverse effects of chronic lead exposure on skeletal development.

Animals

Vertebral and metacarpal morphometry as indicators of nutritional improvement.

Because of the importance of nutrition in the development of bone mass, we studied the nutritional state, and bone state by means of metacarpal radiogrammetric measurements and vertebral morphometry in a group of 40 premenopausal women born between 1960 and 1970, mean age 29 +/- 5 years, and in another group of 40 postmenopausal women born between 1934 and 1944, mean age 55 +/- 4 years. Both groups were considered normal, the main characteristic distinguishing them being that the women born between 1934 and 1944 grew up in a period of widespread malnutrition in Spain and the women born between 1960 and 1970 grew up in a period of normal nutrition. Protein, carbohydrate and fat intake in these two periods differed significantly (p < 0.0001 in the three cases by Fischer's exact test). The values of the metacarpal measurements, anterior height of the dorsal vertebrae from T-4 to T-12, and posterior height from L-1 to L-4 between the premenopausal and postmenopausal groups of women were significantly different (p < 0.001) (Anova test). These findings show the importance of nutrition in the development of bone mass during childhood.

Absorptiometry, Photon

Effect of lead on bone development and bone mass: a morphometric, densitometric, and histomorphometric study in growing rats.

The effect of exposure to lead on the longitudinal development of bone and on bone mass was studied in rats. A group of 35, 50-day-old female Wistar rats was divided into a control group of 15 rats and an experimental group of 20 rats fed a diet supplemented with 17 mg of lead acetate per kg feed for 50 days. Total body bone densitometry (TBBMC) was performed the day before ending the 50-day experiment. On day 50, all rats were killed and their right femur and 5th lumbar vertebra were dissected. The bones were cleaned of soft tissue and femoral length and vertebral length were measured with a caliper and all bones were weighed on a precision scale. Final body weight (P < 0.05), TBBMC (P < 0.005), and femur weight (P < 0.005) were significantly lower in the control group. Femur length did not differ between groups, but the length of the 5th lumbar vertebra was greater in the control group (P < 0.05). Histomorphometry of the femur showed that Cn-BV/TV, Tb-N, Tb-Th were lower (P < 0.05 in all) and Tb-Sp was higher (P < 0.05) in the group given the lead-supplemented diet. These findings suggested lead-induced inhibition of axial bone development and a histomorphometric decrease in bone mass, produced mainly by enhanced resorption, and a densitometric increase in bone mass, produced by lead accumulation in bone.

Animals

Cortical bone resorption in osteoporosis.

A study was made of 110 women: 35 healthy premenopausal, 40 healthy postmenopausal, and 35 women diagnosed as having postmenopausal osteoporosis. The postmenopausal women had similar ages and years since menopause (YSM). In all of the women, total bone mass was evaluated by dual-energy X-ray absorptiometry and metacarpal morphometry was evaluated by radiogrammetry on the second metacarpal of the nondominant hand, performed by computed radiography. An external metacarpal diameter of >/=7.4 mm was required as proof of having developed an adequate peak bone mass. The endosteal diameter, which is indicative of bone resorption in both groups of postmenopausal women, obtained in the postmenopausal groups was subtracted from the endosteal diameter obtained in the premenopausal group and the resulting figure was divided by the years since menopause to calculate the rate of cortical bone resorption/year for each group. The endosteal diameters values differed in the three groups studied (P < 0.0001): 3.2 +/- 0.7 mm in the healthy premenopausal women; 3.9 +/- 0.6 mm in the healthy postmenopausal women; and 4.7 +/- 0.5 mm in the osteoporotic postmenopausal women. The rate of cortical bone resorption was 0.068 +/- 0.002 mm/YSM (years since menopause) in the osteoporotic postmenopausal women and 0.033 +/- 0.003 mm/YSM in the healthy postmenopausal women (P < 0. 0001). These figures reflect the importance of bone resorption, as opposed to deficient bone formation, as a cause of osteoporosis.

Absorptiometry, Photon

Influence of electromagnetic fields on bone mass and growth in developing rats: a morphometric, densitometric, and histomorphometric study.

The effect of electromagnetic fields on bone is debated. In an experimental study of this effect, we compared two lots of growing female rates (both lots n = 15, age 3 weeks, average weight 23.2 +/- 3.3 g), one of which was exposed to a 3-mT, 100-Hz, Helmholtz-type electromagnetic field for 24 hours a day for 30 days, and the other of which served as the control. Bone development and bone mass were evaluated by morphometry, densitometry, and histomorphometry. The rats were killed at 30 days and weighed. The right femurs were dissected, measured, and weighed; bone densitometry was used to determine femoral bone mineral content (BMC) and density (BMD), and histomorphometry of the nondecalcified bone was used to determine trabecular bone volume (Cn-BV-TV%), number (Tb-N mm) and thickness (Tb-Th microm), intertrabecular space (Tb-Sp microm) and growth cartilage thickness (Gc-Th microm). In the rats exposed to the electromagnetic field, BMC and BMD (P = 0.019 and P = 0.002, respectively) and Cn-BV-TV, Tb-N, Tb-Th (P = 0.005, P = 0.036, and P = 0.027, respectively) all were decreased, whereas Tb-Sp was increased (P = 0.002). There were no significant differences in initial and final body weight, or in final femur weight, femur length, and GC-Th. These findings indicate that electromagnetic fields of the type used here reduced bone formation and increased bone resorption without affecting bone development in rats.

Absorptiometry, Photon

Complementary medical treatment for Colles' fracture: a comparative, randomized, longitudinal study.

In 45 women with Colles' fracture, two types of complementary medical treatment (calcitonin with calcium [SCT+Ca] and calcium alone [Ca]) were compared with placebo. Consecutive patients were assigned randomly to one of the three study groups at the time of inclusion in the study: 15 women (68.6 +/- 5.7 years) were given 100 IU/day I.M. of SCT plus 1200 mg of elemental Ca for 10 successive days each month; 15 women (71.7 +/- 6.1 years) were given only 1200 mg of elemental Ca for 10 days each month; and 15 women (66.9 +/- 7. 9 years) were treated with placebo. Biochemical and radiogrammetric studies were made at baseline and after 1 year of treatment. In the SCT+Ca group tartrate-resistant acid phosphatase decreased (Wilcoxon test, P = 0.014) and the metacarpal index and the cortical and total area (CA/TA) ratio increased (both P = 0.001). In the group treated with Ca alone, no changes were observed. In the placebo group, the metacarpal index and CA/TA decreased (P = 0.015 and P = 0.007, respectively). Ca alone, at the dosage used here, inhibited bone loss after Colles' fracture. The addition of SCT to Ca administration not only impeded bone loss but significantly increased cortical bone mass.

Aged

Influence of body mass index on the age-related slope of total and regional bone mineral content.

The influence of body mass index (BMI) on T scores for total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) was studied in 186 healthy women: 100 postmenopausal, 35 perimenopausal, and 51 premenopausal. The three groups were divided by BMI >25 kg/m2 and BMI <25 kg/m2 and the postmenopausal women were further subdivided by years since menopause (YSM): <10, 10-20, and >20. Tartrate-resistant acid phosphatase (TRAP) concentration was higher in perimenopausal and postmenopausal women with BMI <25 kg/m2 (P < 0.001). T scores for TBBMC and for axial or peripheral RBMC differed (P < 0.05 in all) between women with BMI >25 kg/m2 and BMI <25 kg/m2. The rate of perimenopausal and postmenopausal age-related slope of BMC, as reflected in all measurements, differed with BMI. In the overall group of women, the T score for TBBMC correlated significantly with BMI (r = 0.46, P < 0.0001); this correlation increased when adjusted for age (r = 0.62, P < 0.0001). BMI correlated with TRAP only in postmenopausal women (r = 0.57, P < 0. 0001). Yearly TBBMC decline was twice as high in postmenopausal women with BMI <25 kg/m2 (P = 0.0004) than in those with BMI >25 kg/m2; the decline of trunk RBMC was more significant (P < 0.0001). These findings confirm the influence of BMI and gonadal status on bone mass.

Acid Phosphatase