Melatonin in serum and urine in patients with idiopathic pain syndromes

In 16 healthy volunteers, 16 patients with neurogenic pain syndromes, 37 patients with idiopathic pain syndromes, and 30 depressed patients, melatonin in serum was determined at 2 a.m. when the peak concentration was expected. In a somewhat larger series comprising 53 healthy volunteers, 14 patients with neurogenic pain syndromes, and 35 patients with idiopathic pain syndromes, melatonin was measured in urine collected during the night in a standardized manner. Chronic pain patients (with neurogenic or idiopathic pain disorders) and depressed patients had significantly lower melatonin in serum at 2 a.m. than healthy volunteers. Chronic pain patients also had significantly lower melatonin in urine than healthy volunteers, even when age, sex, and body weight were taken into account. The low melatonin concentrations were related to increased depressive symptomatology, especially sadness, bodily discomfort, inner tension, concentration difficulties, and pain. As low concentrations of melatonin in serum and urine also are found in patients with depressive disorders, the results are in line with the suggestion that the chronic idiopathic pain syndrome may be a variant of depressive disease, or the two syndromes may share a common pathogenic mechanism.     

Estimation of instantaneous flow from the indicator-dilution curve after bolus injection of indicator

The indicator-dilution technique is commonly used to determine mean flow estimates. The estimation of instantaneous flow from the shape of an indicator-dilution curve is the objective of this study. Based on a mixing chamber approach to the flow system, a mathematical relationship is derived to reconstruct momentary flow from an indicator-dilution curve. This relationship is verified in a model setup both with only constant flow and with a sinusoidal flow variation superimposed. This method proved to give good flow estimates for limited values of flow parameters. Also, some preliminary experiments were performed in a pulsating flow system simulating heart action. The results were promising although the method proved to be very sensitive to baseline offset.     

Silicone implant for surgery of therapy-refractory glaucomas

A silicone implant for surgery of refractory glaucomas has been developed. It consists of a tube 0.64 mm in diameter glued to the upper surface of a plate resembling a contact lens. The surgical procedure, which is similar to a trabeculectomy, is described.     

Evidence for P2-purinoceptors on human osteoblast-like cells.

ATP released from damaged cells or by controlled secretion could be an important factor in the formation or remodeling of bone. In a variety of other tissues ATP has been shown to control cellular processes by acting on P2-purinoceptors and activating the calcium signaling pathway. Here we demonstrate for the first time that extracellular ATP increases the intracellular free calcium [Ca2+]i concentration in normal human osteoblasts and in SaOS-2 cells, a human osteosarcoma-derived cell line, but not in ROS 17/2.8 cells. The ATP-induced increase in [Ca2+]i was dose dependent, and the concentrations of ATP required were similar to those reported to regulate cellular functions in other cell types. Although ATP is metabolized rapidly by bone cells, the effects on [Ca2+]i appeared to be mediated directly by ATP rather than one of its metabolites. Adenosine 3-thiotriphosphate, a nonhydrolyzable analog of ATP, induced similar changes in [Ca2+]i. This indicates that P2-purinoceptors are present on osteoblast-like cells and that extracellular ATP from various sources might be an important factor in the regulation of osteoblast functions.     

Neuropathy with lysosomal changes in Marinesco-Sj?gren syndrome: fine structural findings in skeletal muscle and conjunctiva.

The light- and electron-microscopical findings in the skeletal muscle and conjunctiva of 6 patients with Marinesco-Sj?gren syndrome (MSS) were presented. All patients were related and showed the cardinal clinical symptoms of the syndrome: congenital cataracts, mental retardation, delayed statomotor development, and cerebellar ataxia. The most prominent alteration found in the skeletal muscle of four patients was extensive neurogenic atrophy with conspicuous groups of atrophic muscle fibers. Additional findings were vacuolar degeneration and secondary, unspecific changes like slight mitochondrial alterations and increased variability in muscle fiber calibers. The ultrastructural examination revealed double-membrane structures near to, but not in direct contact with the nucleus. The nuclear changes described earlier (7, 20) were not found in any of the cases. Conjunctival biopsies revealed a marked increase in the number of lysosomes in fibroblasts. In summary, to the well known myopathic damage of muscles in MSS a neurogenic component should be added. Disturbed lysosomal function is to be considered as the basic abnormality, though the enzyme defect has not yet been identified. In cases of clinically suspected MSS, examination of a conjunctival biopsy is highly recommended.     

Management of Patients After Catheter Ablation of Ventricular Tachycardia

The management of patients after catheter ablation of ventricular tachycardia is not well defined. In this article we summarize recently published results and report our own experience. Factors influencing the clinical outcome of these patients and methods to identify patients with an increased risk of recurrence of ventricular tachycardia are discussed. Furthermore, a review is given on current concomitant therapeutic tools including antiarrhythmic drugs and the implantation of an automatic cardioverter defibrillator.     

Effect of titanium surface texture on the cell-biomaterial interface.

To improve the in vivo performance of engineered implants, this study examines the independent effects of surface chemistry and topography on fibroblast morphology and density in vitro. Titanium (Ti) was sputter-coated onto smooth and microtextured polyethylene terephthalate (PET). Test specimens were evaluated in 24-h, fibroblast cultures and assessed with scanning electron microscopy (SEM) for cellular morphology and density. Fibroblast density increased, as the Ti film thickness increased. The fibroblasts exhibited contact guidance on the textured test specimens. The greatest cellular density was found on the Ti-coated, textured test specimens. In conclusion, Ti and surface texture appeared to strongly influence fibroblast density and morphology as compared to PET and smooth surfaces.