Showing papers by "Saint Francis University published in 1983"

Effect of Glucocorticoids on Type I Collagen Synthesis, Alkaline Phosphatase Activity, and Deoxyribonucleic Acid Content in Cultured Rat Calvariae*

Abstract: Glucocorticoid-induced osteoporosis is believed to be caused by increased bone resorption and decreased bone formation. However, the direct effects of glucocorticoids on bone formation are, as yet, not fully understood. Cortisol, corticosterone, and dexamethasone were examined for their effects on alkaline phosphatase activity, the incorporation of [3H]proline into type I collagen, DNA content, and mitotic index in intact 21-day-old fetal rat calvariae. After 24 h of treatment, cortisol at 1-100 nM increased the incorporation of [3H]proline into type I collagen, whereas at 1-10 microM, cortisol inhibited type I collagen labeling. After 96 h, cortisol (0.1-10 microM) had an inhibitory effect on type I collagen labeling and alkaline phosphatase activity. Cortisol had a small, not dose dependent, and transient stimulatory effect on alkaline phosphatase which appeared after 12-24 h of exposure, whereas the inhibitory effect was dose related, it appeared and was near-maximal after 48 h of continuous treatment with cortisol. Corticosterone and dexamethasone had an effect similar to that of cortisol on type I collagen synthesis and alkaline phosphatase activity. None of the steroids tested affected the release of the enzyme into the culture medium. Cortisol, corticosterone, and dexamethasone did not alter calvarial DNA content after 24 h of treatment, but after 96, concentrations of 1 nM to 10 microM were inhibitory. The decrease in DNA appeared after 48 h of exposure to 100 nM cortisol and was maximal after 72 h. Histological sections showed a marked and generalized decrease in the number of mitoses after colcemid arrest in calvariae treated with 100 nM cortisol, corticosterone, or dexamethasone for 96 h. These studies indicate that glucocorticoids have a dual effect on type I collagen synthesis and alkaline phosphatase activity in cultured calvariae: a transient stimulatory effect after short term treatment and an inhibitory one after long term exposure. The latter is related to a generalized decrease in cell population.

Effect of hormones and growth factors on alkaline phosphatase activity and collagen synthesis in cultured rat calvariae.

Abstract: Studies on the direct effects of hormones and growth factors on bone alkaline phosphatase have been limited to parathyroid hormone (PTH) and 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] and have not been compared to other parameters of bone formation. Insulin, PTH, 1,25(OH)2D3, epidermal and fibroblast growth factors (EGF, FGF) were examined for their effects on alkaline phosphatase activity and type I, [alpha 1 (I)]2 alpha 2, collagen synthesis in cultures of 21-day fetal rat calvariae. After 24 hr and 96 hr of treatment, insulin increased whereas PTH, 1,25(OH)2D3, EGF and FGF inhibited calvarial alkaline phosphatase activity and the incorporation of 3H-proline into collagenase-digestible protein and type I collagen. The agents tested did not affect the release of alkaline phosphatase into the culture medium. Although type I collagen was the only collagen detected, a small amount of another collagen might have been also synthesized. The hormonal effects on alkaline phosphatase activity and type I collagen synthesis were of greater magnitude after 96 hr than after 24 hr of continuous exposure to the agents tested and the two parameters correlated well (r = 0.88 after 96 hr and r = 0.97 after 24 hr of treatment. These studies indicate that insulin increases bone alkaline phosphatase activity and type I collagen synthesis in calvariae whereas PTH, 1,25(OH)2D3, EGF and FGF have an inhibitory effect. The results suggest that these agents affect osteoblastic function.

Fournier's gangrene: A general surgery problem

Abstract: Fournier's gangrene is a specific form of synergistic gangrene involving the scrotum and perineum. The disease may follow a variety of clinical conditions or occur without an apparent precipitating cause. It is associated with severe systemic toxicity and a significant mortality rate, and it demands prompt recognition and urgent, aggressive surgical intervention. Its treatment calls on the full armamentarium of the general surgeon. Preoperative resuscitation is often required. Operative debridement can be extensive, involving the buttocks and on occasion the upper thighs and abdominal wall. Postoperative management consists of wound care with eventual grafting or flap rotations. Colostomy may be required. Three cases illustrating the salient features of this disease are presented, together with a review of the literature.

Rupture of Indwelling Venous Catheters

Abstract: Recently a design change in certain Broviac and Hickman catheters has created a serious problem. The paper described the defect and a means of reinforcing the catheter both before it is inserted and after it is in place.

Hb S Mobile: A New Genetic Combination

Abstract: The genetic combination of Hb Mobile (β73 Asp→ Val) and Hb S (β6 Glu →Val) was found in a healthy black man whose hemolysate resembles that of Hb S electrophoretically. His mother and sister have Hb AS; the father and brother have Hb A Mobile. No clinical nor hematologic abnormalities were detected in any member of the family. A slightly decreased oxygen affinity associated with Hb Mobile appears to have no clinical significance. Simple methods of differentiating Hb Mobile S from the electrophoretically similar but clinically severe Hb SD Los Angeles are described.