[Hypercalcemic crisis and hypocalcemic tetany]. / Hyperkalzämische Krise und hypokalzämische Tetanie.

A serum calcium level >3.5 mmol/l together with clinical symptoms such as muscle weakness, fatigue, nausea, vomiting, pancreatitis or even coma are characteristic for a hypercalcemic crisis (HC). Primary hyperparathyroidism (1HPT) and malignancy-associated hypercalcemia are the most frequent causal diseases for a HC. The analysis of serum levels for calcium, phosphorous, intact parathyroid hormone, electrophoresis and renal function parameters indicate which further radiological, scintigraphic or serum diagnostic steps are adequate to identify the cause of the patient's acute situation (i. e. most frequently 1HPT or malignant disease with bone involvement, e. g. myeloma) and thus to initiate the required surgical or oncological intervention. However, the primary goals in the treatment of HC include correcting dehydration and improving kidney function, lowering calcium levels and decreasing osteoclastic bone resorption. The goals are accomplished by volume repletion, forced diuresis, antiresorptive agents and hemodialysis on an intensive care unit. Hypocalcemic tetany (HT) is the consequence of severely lowered calcium levels (<2.0 mmol/l), usually in patients with chronic hypocalcemia. The causal disease for hypocalcemic tetany is frequently a lack of parathyroid hormone (PTH), (e. g. as a complication of thyroid surgery) or, rarely, resistance to PTH. HT due to severe and painful clinical symptoms requires rapid i. v. calcium replacement by central venous catheter on an intensive care unit. For the treatment of chronic hypocalcemia oral calcium and 25OH-vitamin D or even 1,25(OH)2-vitamin D3 and magnesium supplements may be necessary to achieve the desired low normal calcium levels. Thiazides are useful to reduce renal calcium loss and to stabilize the calcium levels. Some patients continue to exhibit clinical symptoms despite adequate calcium levels; in these cases s. c. parathyroid hormone 1-84 should be considered to stabilize calcium levels and to lower the dosage of calcium and vitamin D supplements.

Relevance of laser irradiance threshold in the induction of alkaline phosphatase in human osteoblast cultures.

Induction of matrix synthesis by low-level laser has been demonstrated extensively. However, the question of dose- or power intensity-dependency is under-investigated. To address this issue we chose human osteoblast cell cultures and measured their alkaline phosphatase (ALP) activity after laser irradiation. The cell cultures were irradiated periodically by 690 nm radiation via optical transmission fiber-based laser needles, reaching into the culture dishes. The osteoblasts showed no induction of ALP activity when we used a single laser needle stimulation with a laser irradiance of 51 mW/cm(2), an increase of approximately 43% at 102 mW/cm(2) irradiance (two needles per well) and a ninefold increase at 204 mW/cm(2) irradiance (four needles per well), leaving the temperature of the culture medium unaffected. We concluded that the osteoblastic response in ALP activity to a laser stimulus shows a logarithmic relationship, with a distinct threshold, rather than a linear dose-dependency. Secondly, the laser irradiance, rather than the dose, is relevant for the impact of the laser.

[Screening for osteoporosis]. / Osteoporosescreening.

Osteoporosis affects approximately 7 million patients in Germany and severely impairs quality of life. The clinical picture, subjective complaints as well as the presence or absence of risk factors are essential to determine the individual risk profile and to decide on possible serum blood tests, osteodensitometry, and X-ray examinations. Back pain or other clinical evidence of impaired bone stability should be evaluated with X-ray studies of the spine. If osteoporosis and an increased risk of fracture are present, treatment is indicated which includes an evidence-based pharmaceutical regimen in order to increase bone stability and to lower the risk of fractures. Drug treatment with adequate calcium and vitamin D supplementation and antiresorptive or osteoanabolic substances, usually for 3-5 years, should be accompanied by pain medication and neuromuscular rehabilitation to help prevent falls and maintain independence of the elderly.