1,721,303 research outputs found
A five-day treatment of tumor-induced hypercalcemia by intravenous amino-hexane (AHBP) or aminobutane (ABBP) bisphosphonate
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Electroplastic effect in specimens of duplex stainless steel under tension
No full textDuplex stainless steels (DSSs) possess a typical biphasic microstructure consisting of equal amount of ferrite and austenite, which provides better combination of the mechanical and corrosion properties compared to the austenitic grade. Despite their good processability, they suffer from embrittlement of secondary phases in a very specific temperature range 450 – 1000°C depending on the composition. Solubilizing treatment after processing is required to obtain a perfect balance between austenite and ferrite and moreover, to dissolve any secondary phases that could have been formed during processing. This implies very high energy consumption of forming processes due to a high temperature (above 1000°C) or high power needed for the forming machines. The electroplastic effect could be used to reduce the force needed to form the material and extend the forming limits. The effect consists in direct interaction between the electrons of the electrical current and the ions of the material. The current mode (e.g., continuous current, pulsed current, pulse duration and duty cycle) plays an important role in the occurrence and the extent of the electroplastic effect. The electroplastic effect is investigated under tension in two-phase duplex stainless steel UNS S32205. Tensile tests under different current conditions (current density and frequency) are compared to room temperature tests. The best effect in terms of reduction of the ultimate tensile strength and increase in the fracture strain is achieved by introducing a multi-pulse current with the maximum density and pulse duration
Effects on the bones of nandrolone decanoate therapy in postmenopausal osteoporosis [Effetti ossei della terapia con nandrolone decanoato nella osteoporosi postmenopausale]
No full textIn many patients with involutional osteoporosis, anabolic steroids may produce a rapid subjective improvement and pronounced reduction of complaints. In animal experiments it has been demonstrated that anabolic steroids can also have objective effect on bone tissue. Twenty postmenopausal osteoporotic patients have been randomly assigned to two different treatments: 10 patients were treated with 50 mg i.m. of nandrolone decanoate every 3 weeks for 12 months; 10 patients were treated with placebo. Both groups received an oral calcium supplement (1 g/day). Bone mineral content (BMC) was measured by dual photon absorptiometry before and after 1, 3, 6 and 12 months. Plasma alkaline phosphatase (A.Ph.) and urinary hydroxyproline/creatinine ratio (HOP) were measured at the same times. Intestinal calcium absorption was measured by the 47Ca oral test before and after treatment. In 4 patients of both groups a transiliac bone biopsy was performed before and after treatment. After 1 year there was a significant increase in the BMC of the lumbar spine in the group receiving calcium plus nandrolone decanoate. A progressive but not significant increase of A.Ph. was observed in the group treated with nandrolone decanoate. Radiocalcium absorption significantly increased in nandrolone treated patients. The histomorphometric study of bone demonstrated a significant increases in trabecular bone volume and in active osteoid surfaces in patients treated with nandrolone decanoate. Because the plasma A.Ph. tendes to increase with no change in bone resorption (as measured by urinary HOP) and the active osteoid surfaces significantly augment, we conclude that nandrolone therapy increases the bone formation rate
Hypertension and primary hyperparathyroidism: the role of adrenergic and renin-angiotensin-aldosterone systems
No full textPrimary hyperparathyroidism (HPTH) is frequently associated with hypertension. To date, the relationship between these two conditions is still not clear. We have studied 34 consecutive patients with primary HPTH due to a parathyroid adenoma. The diagnosis was later surgically confirmed in 32 cases. Ten of thirty-four HPTH patients were hypertensive. Before adenomectomy (PTHX) and 1-2 months after PTHX, we measured the following parameters in all patients: circulating levels of total and ionized Ca, intact immunoreactive parathormone (iPTH) (1-84), plasma renin activity (PRA), aldosterone, and daily total urinary catecholamine excretion. Moreover, 10 hypertensive HPTH patients, 10 normotensive HPTH patients, compared to 10 to 10 sex- and age-matched healthy normotensive subjects, underwent an acute norepinephrine test to assess vascular reactivity to a pressor agent. Before PTHX, no significant difference was observed between normotensive and hypertensive patients in all the above-mentioned variables, except for PRA and plasma aldosterone levels which were higher in hypertensive patients. Furthermore, the pressor response to the norepinephrine test was significantly greater in hypertensive HPTH patients than in the other 2 groups. After PTXH, serum Ca and intact iPHT (1-84) levels were reduced to normal values in all patients, while blood pressure, PRA and plasma aldosterone levels became normal in 8 of 10 hypertensive patients. The pressor response to the norepinephrine test was similar in the 2 groups. These results are consistent with the hypothesis of a direct effect of PTH on renin secretion which could contribute to the pathogenesis of hypertension and to the vessels sensitization to pressor agents
Circulating levels of immunoreactive parathyroid hormone (PTH) and calcitonin (CT) In bronchogenic carcinoma
No full textImproved enantioselective synthesis of anti α-methyl-β-hydroxy esters through TiCl4-PPh3 mediated aldol condensation
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