The effects of parathyroid hormone applied at different regimes on the trochanteric region of the femur in ovariectomized rat model of osteoporosis.

This study aims to investigate the effects of two application frequencies of parathyroid hormone on the trochanteric region of rat femur. Forty-three-month-old female Sprague-Dawley rats were divided into 4 groups (n = 10/group). Three groups were ovariectomized, and 8 weeks later they were administered the following treatments (5 weeks): soy-free diet (OVX), subcutaneously injected PTH (0.040 mg/kg) 5 days a week (PTH 5x/w), subcutaneously injected PTH (0.040 mg/kg) every 2 days (PTH e2d), and a sham group. The values of the biomechanical and histomorphometric parameters showed higher results in 5x/w animals in comparison to the OVX and PTH 2ed groups. The ratio between bone diameter/marrow diameter (B.Dm/Ma.Dm) in subtrochanteric cross sections did not show any significant differences between PTH 5x/w and PTH e2d. The increased bone formation rate was observed under PTH treatment in both groups mainly at the endosteal side. The endosteum seems here to be one of the targets of PTH with an accelerate bone formation and a pronounced filling-in of intracortical cavities with higher intensity for the PTH 5x/w in comparison to PTH e2d rats.

Effect of parathyroid hormone on hypogonadism induced bone loss of proximal femur of orchiectomized rat.

PURPOSE: Management of hypogonadism-induced osteoporosis in elderly men is still a challenge. We investigated the short-term effects of parathyroid hormone (PTH) treatments on strength, micro-architecture, and mineral density of trochanteric region of orchiectomized rat femur. METHODS: Eight-month-old male Sprague-Dawley rats (n = 44) were divided into two groups: (1) orchiectomized (ORX) and (2) sham group. Twelve weeks after orchiectomy, half of the orchiectomized animals were treated with daily subcutaneously injected PTH (0.040 mg/kg/BW) (ORX-PTH) for 5 weeks. The other half remained untreated (ORX). The sham-operated group was divided and treated in the same way (sham, sham-PTH). After 5 weeks, both femurs were excised for biomechanical and histomorphometric analysis, trabecular measurements, mineral content assessment, and immunofluorescence analysis. RESULTS: The femoral trochanteric strength after PTH treatment was enhanced in the breaking test (ORX-F(max) = 158.7 N vs. ORX + PTH-F(max) = 202 N). Stiffness of treated ORX animals reached nearly the levels observed in untreated sham rats. PTH therapy improved the trabecular connectivity, width, and area (ORX-Tb.Ar = 47.79% vs. ORX + PTH-Tb.Ar = 68.47%, P < 0.05) in the proximal femur. The treated rats showed significantly improved mineral content in ashed femurs (ORX-mineral content = 43.73% vs. ORX + PTH-mineral content = 49.49%) when compared to the untreated animals. A comparison of widths of fluorescence bands in cortical bone of the subtrochanteric cross-sections showed a significant increase in oppositions after the PTH therapy. CONCLUSIONS: Our finding supports the hypothesis that PTH therapy seems to be a rational therapy in patients with hypogonadism induced bone loss and improves the bone strength of trochanteric region of rat femur.

Improvement of femoral bone quality after low-magnitude, high-frequency mechanical stimulation in the ovariectomized rat as an osteopenia model.

The treatment and prevention of osteoporosis involve great challenges. Nonpharmacological and supportive therapy procedures, sport, and physical exercises seem to prevent bone loss and improve bone mass. In the present study, we examined the effect of whole-body vertical vibration (WBVV) on femoral intertrochanteric bone quality in the rat osteoporosis model. Sixty female Sprague-Dawley rats, 3-month old, were ovariectomized (OVX) or sham-operated. After 3 months, each group was divided into two subgroups. In one of the subgroups, rats were treated with WBVV at 90 Hz (3.9 g) for 35 days; the second subgroup remained untreated. After killing the animals, biomechanical strength and trabecular bone architecture of the proximal region of femurs were analyzed. New cortical bone appositions and mineral density of femurs were additionally measured. Treatment with WBVV resulted in improved biomechanical properties. Maximal load and stiffness of the intertrochanteric region of femurs after WBVV were significantly enhanced. Maximal load and stiffness in treated OVX animals reached the levels observed in untreated sham rats. WBVV significantly improved all measured histomorphometric parameters in the trabecular area. Treated rats showed significantly improved mineral content in ashed femurs compared to untreated animals. A comparison of widths of fluorescence bands in cortical bone of subtrochanteric cross sections did not show any significant differences between the groups after WBVV. Low-magnitude, high-frequency mechanical stimulation improves bone strength in the proximal femur and may be a possible nonpharmacologic treatment option for postmenopausal osteoporosis.

Tissue calcium content in piglets with inguinal or scrotal hernias or cryptorchidism.

Scrotal and inguinal hernias are of great economic importance to the pig industry. These lesions are thought to result from incomplete closure of the inguinal ring and/or a patent processus vaginalis. Impairment of programmed cell death (PCD) may be involved in these abnormalities. As tissue Ca(2+) overload may be used as a measure of cell death, the aim of this study was to determine the tissue Ca(2+) content in samples of hernia sac, peritoneum, cremaster muscle and aqueous fluid from newborn piglets with scrotal or inguinal hernias (n=18) or cryptorchidism (n=18). Control samples from healthy piglets (n=20) were also evaluated. Tissue Ca(2+) content was determined by atomic absorption spectrophotometry. Significantly less Ca(2+) was found in the sacs (0.005 mg/g wt), peritoneal tissue (0.100 mg/g wt) and cremaster muscles (0.008 mg/g wt) of piglets with inguinal or scrotal hernias compared with control tissues (0.184, 0.144 and 0.048 mg/g wt for sacs, peritoneal tissue and cremaster muscles, respectively). These findings suggest that there may be perturbation of the apoptotic pathway in the urogenital tissues of affected piglets.

The demographic consequences of U.S. Jewish population trends.

PIP: This study is concerned with the population dynamics of the U.S. Jewish population. It is an extension of a previous study by Sidney Goldstein and develops the themes elaborated in that study in two directions: further investigation of nuptiality, fertility, and mixed marriage; and quantitative assessments of alternative projections of future population. The data are primarily taken from the National Jewish Population Study of 1970-1971. The authors conclude that the balance of internal population dynamics of U.S. Jewry is probably negative and, despite immigration, will become progressively more negative in the future.^ieng