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Biomedical subjects

J D Ringe

Publications and source records attributed to J D Ringe.

At least 19 recordsLinked to original sources
PubMed1994

[Pathogenesis of postmenopausal osteoporosis].

Low peak bone mass and increased bone loss within the process of bone remodelling are the most important determinants for the manifestation of postmenopausal osteoporosis. Both are influenced during lifetime by a large number of risk factors additively leading to a critical low bone mass. Loss of bone substance and deterioration of architecture of bone tissue lead to an increased fragility of the skeleton. In this complex interactions menopausal decrease of endogenous estrogen secretion is of special importance. Decrease of estrogen induces by effects on calcitropic hormones and different local growth factors a high bone turnover with a high rate of bone loss. The resulting slight increase of serum calcium and the consequent decrease in the secretion of parathyroid hormones and activation of vitamin D in the kidneys lead to a decreased intestinal calcium absorption. In peri- and early postmenopausal women there is a large range of different degrees of bone turnover. It is unclear however, whether there are really two distinct groups of so-called rapid and slow bone losers. It remains to clarify which intrinsic mechanisms besides the risk factors are responsible for the individually different answer of calcium and bone metabolism to estrogen deficiency, which is the same in every women.

Adult↗
PubMed1992

Effects of calcium channel blocking and atrial stimulation on QT time during hyper- and normocalcemia in man.

We investigated how calcium channel blocking agents modify the known decrease of QT time with increasing heart rate and calcium level. Furthermore, we examined how the influence of calcium channel blocking agents is modulated by atrial stimulation. To answer these questions, we measured the QT time both at a spontaneous heart rate and during atrial stimulation with 90 and 110 beats/min before and after intravenous administration of 5 mg verapamil in 23 patients with primary hyperparathyroidism, pre- and postoperatively. Atrial stimulation increased the frequency-related standard values of QT time. The spontaneous heart rate (HR) was influenced by neither the calcium level nor verapamil. The statistically significant correlations QT vs. HR and QT vs. Ca were reduced by verapamil, which indicated its influence. However, this effect did not achieve statistical significance.

Electrocardiography↗
PubMed1992

[Risk of osteoporosis in long-term heparin therapy of thromboembolic diseases in pregnancy: attempted prevention with ossein-hydroxyapatite].

Generalized idiopathic osteoporosis and transient osteoporosis of the hip are both rare complications of pregnancy. More frequently, long-term heparin administration to treat deep thrombosis in the legs or pelvis may lead to substantial decreases in bone mass and consequently increased risk of osteoporosis. Therapeutic studies with the aim to counteract the osteoporosis inducing effect of heparins, have not been published to date. In the special situation of pregnancy, most medications used for osteoporosis are contraindicated. In our open randomised study, 9 women on heparin-treatment received daily 6.46 g of the bone preparation OHC (ossein-hydroxyapatite-compound) over a period of 6 months and were compared to 11 women without bone protective treatment. In the OHC-group, good compliance was observed with no side effects and reduced back pain. Bone mass did not change significantly, whilst it dropped significantly statistically in the controls.

Adult↗
PubMed1991

[Calcitonin in the prevention and therapy of osteoporosis].

Main arguments for application of calcitonin in the therapy of osteoporosis are specific inhibition of osteoclasts, analgetic effect and stimulation of osteoblasts, the latter demonstrated only in vitro so far. Calcitonins are mostly used only for a short term in acute painful phases of osteoporosis. For salmon calcitonin, which has been tested most up to now, it has been demonstrated that its application in primary osteoporosis up to one year leads to a moderate but significant increase in bone mass. This metabolic effect on bone has been reached in the majority of studies in a combination with 500 to 1000 mg of calcium. The secondary clinical resistance observed after even longer application is presumably not so much a problem of antibodies than the consequence of depressed bone remodelling due to chronic inhibition of osteoclasts. The circulating antibodies during application of salmon calcitonin are only partially also neutralising. As to human calcitonin, therapeutic studies of corresponding length in manifest osteoporosis do not yet exist. Salmon calcitonin as nasal spray inhibits the increased postmenopausal skeleton breakdown in sound women during application of up to two years at present. In steroid-induced osteoporosis there are positive therapeutic results for both injectable and nasal calcitonin. Calcitonin therapy of osteoporosis in phases of some weeks to some months can be generally recommended nowadays. For a long-term therapeutic recommendation we still lack further studies in order to evaluate the effects of different dosage, mode of application and intermittent application.

Administration, Intranasal↗
PubMed1990

[Treatment of primary osteoporosis with calcium and salmon calcitonin].

Fifty-nine consecutive patients (19 men, 40 women, mean age 60.8 [27-80] years) with primary osteoporosis were studied to see if there was any significant gain in bone mass after treatment with salmon calcitonin. All the patients were given 1 g calcium by mouth every morning. Group 1 (n = 20) received no other specific medication while group 2 (n = 19) were given 100 I.U. calcitonin subcutaneously every second evening and group 3 (n = 20) received the same dose every evening. The pain reported by the patients was subdivided into four severity grades, and analgesic consumption was recorded. In group 1 there was a nonsignificant decrease in pain, but in groups 2 and 3 there was a highly significant diminution in pain (P less than 0.005) and in analgesic intake (P less than 0.01). Measurements of bone density carried out by photon absorption at the end of 12 months showed a 5.5% increase in the distal radius in group 2 (P = 0.0001) and a 7.1% increase in group 3 (P = 0.0001), while in group 1 mineral content had decreased by 4.3% (nonsignificant). These results show that a significant gain in bone mass can be achieved by administration of calcitonin, either daily or on alternate days. The incidence of extravertebral fractures and of new or progressive vertebral deformity tended to be lower in groups 2 and 3 than in group 1.

Administration, Oral↗
PubMed1990

[Pathogenesis of corticoid-induced osteoporosis].

Corticoid osteoporosis is the most important of the so-called secondary forms of osteoporosis. Although, in recent years, our knowledge of the pathomechanisms involved have been expanded, at the cellular and molecular-biological level, it remains incomplete. In practical-clinical terms, however, the following main effects of corticoids on bone metabolism and the calcium balance can be identified: inhibition of osteoblastic bone matrix synthesis and enhancement of osteoclastic bone absorption. This latter is promoted by inhibition of intestinal calcium absorption and tubular reabsorption of calcium with subsequent mild secondary hyperparathyroidism. These mechanisms suggest possibilities for the prevention and treatment of this form of osteoporosis.

Adrenal Cortex Hormones↗
PubMed1990

[Intranasal salmon calcitonin for the prophylaxis of bone mineral loss in steroid-treated chronic obstructive lung diseases ].

In the present controlled study the effect of calcitonin nasal spray (CAS 47931-85-1; Lachs-Calcitonin Nasal spray Sandoz) on the bone mineral content was investigated in 36 patients in need of corticosteroid therapy suffering from chronic, obstructive lung diseases. The treatment consisted of 200 IU intranasal daily and lasted for one year. In the control group there was a statistically significant decline of bone mineral content of 5% or 4.3% concerning the lumbar vertebrae L1-L4 and the femur, whereas in the treated group there was only a statistically not significant decrease of 0.9% and 0.8%, respectively. These findings show that calcitonin nasal spray in a dose of 200 IU daily is quite useful for the prophylaxis of steroid-induced osteoporosis.

Administration, Intranasal↗