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Biomedical subjects

H Rico

Publications and source records attributed to H Rico.

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

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

Total body bone measurements in spinal osteoporosis by dual-energy X-ray absorptiometry.

Changes in total body bone mineral content (BMCTB) and density (BMDTB), and the T-score of BMCTB and (BMDTB) were evaluated in relation to the number of vertebral fractures in women with postmenopausal osteoporosis for the purpose of defining deviations in these parameters that could be predictive of the occurrence of vertebral fracture. The study group consisted of 62 women diagnosed with postmenopausal osteoporosis. All of them had two or more spinal fractures. Regression analysis of the number of fractures against each parameter studied indicated that the following were predictive of the risk of fracture: a reduction of -0.5 in the T-score of both BMCTB and BMDTB (P < 0.0001) and a loss of about 135 g of BMCTB or 0. 058 g/cm2 of BMDTB (P < 0.0001). The fact that such changes were found during the follow-up of women with osteoporosis highlights the importance of bone mass measurements during follow-up.

Absorptiometry, Photon↗
PubMed1997

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↗
PubMed1997

Comparison of three bone densitometry methods in osteoporotic women.

Three techniques of bone mass measurement were evaluated in the diagnosis of postmenopausal osteoporosis; the overlap in the measurements and the capacity for discriminating was determined among 51 postmenopausal normal (mean age 66.6 +/- 8.4 years) and 42 postmenopausal osteoporotic women (mean age 68.5 +/- 7.5 years). All bone mass was evaluated by total body bone mineral content (BMCTB), density (BMDTB), ultrasound bone velocity (UBV) in proximal phalanxes 2-5 of the nondominant hand (UBV = mean value of all ultrasound measurements), and peripheral quantitative computed tomography of the nondominant forearm (pQCT). BMCTB was found to be significantly better (P < 0.0001) for diagnosing postmenopausal osteoporosis than the other methods; both cortical and trabecular pQCT measurements were more discriminating than the corresponding UBV measurements (P < 0.001). T-score values in normals, subjects versus osteoporotic ones were BMCTB -1.15 +/- 0.79 versus -3.17 +/- 0.74; BMDTB -1.01 +/- 0.97 versus -3.28 +/- 0.81; UBV -1.51 +/- 1.02 versus -2.34 +/- 1.21; trabecular-pQCT -0.40 +/- 0.72 versus -1.57 +/- 0.37; cortical-pQCT -1.00 +/- 0.87 versus -2.67 +/- 0.53; and total-pQCT -0.65 +/- 1.01 versus -2.34 +/- 0.27, respectively. The overlap in values between the postmenopausal normal and postmenopausal osteoporotic groups was 50% with UBV, 6% with BMCTB, 9% with BMDTB, 25% with cortical pQCT, and 42% with trabecular pQCT. BMCTB, BMDTB, UBV, and pQCT correlated well with each other as measurements of bone mass, but BMCTB was more discriminating than the other measurements in the diagnosis of osteoporosis.

Absorptiometry, Photon↗
PubMed1997

Influence of weight and gonadal status on total and regional bone mineral content and on weight-bearing and non-weight-bearing bones, measured by dual-energy X-ray absosorptiometry.

OBJECTIVE: To evaluate the influence of weight on total body bone mineral content (BMCTB) and regional body bone mineral content (head, arms, trunk and legs). This was studied in accordance with gonadal status and the weight-bearing or non-weight-bearing status of each region. METHODS: The study included 94 postmenopausal women (mean age 60.6 +/- 10.5 years), 36 perimenopausal women (mean age 49.0 +/- 2.3 years) and 60 premenopausal women (mean age 36.1 +/- 6.9 years). Full-body bone densitometry (DXA), for measuring total body bone and regional bone mineral content, was carried out in all the women. RESULTS: Among these groups, the influence of 1 kg of body weight on total and regional bone mineral content (percent) did not differ (paired test P ns). In the overall group of women, paired comparison showed differences between the head and other zones measured (P = 0.036-0.004). In the overall group of women, no differences were found in the percent influence of 1 kg body weight on bone mineral content in any study zone (by ANOVA, Fisher's PLSD post hoc test and the Kruskal-Wallis test). In the overall group of women, Fisher's r to z test revealed a non-significant relationship between weight and the bone mineral content of the head (r = 0.49, P ns) but in every other region the relationship between weight and bone mineral content was significant (r = 0.36-0.54, P < 0.0001 in all). CONCLUSIONS: The effect of body weight on BMCTB and regional did not differ significantly with either gonadal status or weight-bearing (legs) and non-weight-bearing bones (arms).

Absorptiometry, Photon↗
PubMed1997

Heterogeneity of trabecular and cortical postmenopausal bone loss: a longitudinal study with pQCT.

Eighty-one women were studied longitudinally to measure trabecular bone mineral density (BMDTrab) and cortical bone mineral density (BMDCorti) in the distal radius by peripheral quantitative computed tomography (pQCT) at intervals of about 1 year and to calculate the rate of percent change/year. Fifty-three women were naturally postmenopausal [mean age 63.3 +/- 5.3 years, age at menopause 50.7 +/- 3.8 years, 13 years since menopause (YSM)] and 28 had been ovariectomized (mean age 52.7 +/- 5.8 years, age at menopause 39.5 +/- 5.0 years, 13 YSM). There was no difference between groups (ANOVA) in the rate of percent change/years in BMDTrab (p = 0.692), but there was in BMDCorti (p = 0.020). When the women who had either gained or lost bone mass were compared (chi-square test), only BMDCorti differed significantly (p = 0.018). Considering > -2.5% change/years as the limit for rapid bone mass loss, BMDTrab values showed that 43% of the naturally postmenopausal women and 42.7% of the ovariectomized women had rapid bone loss (p ns). On the basis of BMDCorti values, 45% of the naturally postmenopausal women and 28.4% of the ovariectomized women had rapid bone loss (p = 0.018). Height, weight, body mass index (BMI), age, YSM, and years of reproductive life did not differ (ANOVA) between the women who gained or lost either BMDTrab or BMDCorti. Using Fisher's r to z and partial correlation adjusted for age and YSM of the percent change/year in BMDTrab and BMDCorti in the overall group and in each menopausal group, only BMDCorti differed.

Aged↗
PubMed1997

Ultrasound bone velocity on proximal phalanges in premenopausal, perimenopausal, and postmenopausal healthy women.

RATIONALE AND OBJECTIVES: The authors studied premenopausal, perimenopausal, and postmenopausal women to determine if ultrasound bone velocity (UBV) on proximal phalanges of women reflect bone changes related to gonadal status and age. METHODS: A total of 166 healthy women-64 postmenopausal women (mean age 58.7 +/- 9.4 years), 41 perimenopausal women (mean age 49.5 +/- 2.9 years), and 61 premenopausal women (mean age 36.8 +/- 7.1 years)-were studied. All the women underwent UBV study of the 2nd to 5th proximal phalanges on the nondominant hand and the mean value of all ultrasound measurements was calculated. RESULTS: The postmenopausal women had a UBV that differed significantly, one-way analysis of variance, from that of the perimenopausal women and premenopausal women (both P < 0.001). The UBV measurements of the perimenopausal women differed significantly from those of the premenopausal women (P < 0.01). Simple linear regression analysis of the relation between UBV and age showed that this was significant and negative in the overall group of women (r = -0.69; P < 0.0001), significant in the perimenopausal (r = -0.66; P < 0.001) and postmenopausal women (r = -0.69; P < 0.001) and nonsignificant in the premenopausal women (r = 0.08; P not significant). In the postmenopausal women, the correlation between UBV and years since menopause was larger (r = -0.71; P < 0.0001) than the correlation between UBV and chronological age. CONCLUSIONS: Ultrasound bone velocity of the phalanx, as a method for measuring changes in bone with age, has a precision that makes it possible to detect changes in bone mass in perimenopausal women and may perform similarly to other bone mass measurements.

Adult↗
PubMed1997

Influence of soft tissue (fat and fat-free mass) on ultrasound bone velocity: an in vivo study.

RATIONALE AND OBJECTIVES: The authors determine the relative effect of soft-tissue compartments, body fat (percent [%Bfat] and weight [Bfat kg]) and fat-free mass (FFM kg), on measurements of ultrasound bone velocity (UBV m/second). METHODS: The authors measured UBV in proximal phalanxes and body fat and fat-free mass by near infrared interactance in 40 healthy premenopausal women (mean age +/- standard deviation 28.2 +/- 3.8 years). RESULTS: Correlation study (Fisher's r to z) showed that UBV correlated negatively with %Bfat (r = -0.61, P < 0.0001), Bfat kg (r = -0.56, P = 0.0001) and marginally with body weight (r = -0.33, P = 0.0403), but did not correlate with FFM kg or H2O L (both r = -0.08, P not significant). When the correlation test was adjusted for weight and age (partial correlation), the negative correlation between UBV and %Bfat persisted (r = -0.54, P < 0.0005; and r = -0.63, P < 0.0001, respectively) and the correlation with FFM kg, adjusted for weight, became positive and significant (r = 0.55, P < 0.0005). CONCLUSIONS: These results, to our knowledge, are the first to be obtained by in vivo evaluation of UBV in relation to body fat and fat-free mass. Body fat, but not fat-free mass, was the main factor affecting UBV. This confirms the deficiency of UBV measurements, considering that obesity is a protective factor for bone mass.

Adipose Tissue↗
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

Study of supramolecular structures released from the cell wall of Candida albicans by ethylenediamine treatment.

Candida albicans cell wall components were analyzed by ethylenediamine (EDA) treatment. Based on their different solubility properties, the cell wall components produced three fractions (A, B, and C). Fractions B (EDA-soluble, water-insoluble) and C (EDA-insoluble) contained glucan, chitin, and protein in different proportions. After zymolyase (mainly a beta-glucanase complex) or chitinase treatment of fractions B and C, more polysaccharides and proteins were solubilized by a second EDA treatment, suggesting that the solubility of the polymers in EDA depends on the degree of polymer interactions. Western blot analysis using two monoclonal antibodies (1B12 and 4C12) revealed electrophoretic patterns that were similar in mycelial and yeast morphologies, except that in material obtained from mycelial walls, an additional band was detected with MAb 1B12. Fluorescence microscopy of cell wall fractions treated with FITC-labeled Con-A, Calcofluor white, and FITC-labeled agglutinin showed that glucan and mannoproteins are uniformly distributed in fractions B and C, while chitin is restricted to distinct patches. Transmission electron microscopy demonstrated that fraction C maintained the original shape of the cells, with an irregular thickness generally wider than the walls. When fraction C was treated with chitinase, the morphology was still present and was maintained by an external glucan layer, with an internal expanded fibrillar material covering the entire cellular lumen. Degradation of the glucan skeleton of fraction C with zymolyase resulted in the loss of the morphology.

Blotting, Western↗
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↗