In vitro exposure of human osteoarthritic chondrocytes to ELF fields and new therapeutic application of musically modulated electromagnetic fields: biological evidence.

Osteoarthritis (OA) is the most frequently occurring rheumatic disease, caused by metabolic changes in chondrocytes, the cells that maintain cartilage. Treatment with electromagnetic fields (MF) produces benefits in patients affected by this pathology. Isolated human osteoarthritic (OA) chondrocytes were cultured in vitro under standard conditions or stimulated with IL-1beta or IGF-1, to mimic the imbalance between chondroformation and chondroresorption processes observed in OA cartilage in vivo.

Alterations in adenylate kinase activity in human PBMCs after in vitro exposure to electromagnetic field: comparison between extremely low frequency electromagnetic field (ELF) and therapeutic application of a musically modulated electromagnetic field (TAMMEF).

This study investigated the effects of electromagnetic fields on enzymes involved in purine metabolism in human peripheral blood mononuclear cells in vitro. Cells were obtained from 20 volunteers. We tested both low-energy, extremely low frequency (ELF; 100-Hz) electromagnetic fields and the Therapeutic Application of Musically Modulated Electromagnetic Fields (TAMMEFs); the latter is characterized by variable frequencies, intensities, and wave shapes.

Evidence of a new phosphoryl transfer system in nucleotide metabolism.

Crude rat liver extract showed AMP-AMP phosphotransferase activity which, on purification, was ascribed to a novel interaction between adenylate kinase, also known as myokinase (EC 2.7.4.

A kinetic study of the rat liver adenosine kinase reverse reaction.

Adenosine kinase is an enzyme catalyzing the reaction: adenosine + ATP --> AMP + ADP. We studied some biochemical properties not hitherto investigated and demonstrated that the reaction can be easily reversed when coupled with adenosine deaminase, which transforms adenosine into inosine and ammonia. The overall reaction is: AMP + ADP --> ATP + inosine + NH(3).

Adenosine kinase gene expression in human colorectal cancer.

Real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate gene expression of adenosine kinase, a key enzyme in adenosine metabolism, in human intestinal biopsy specimens of 10 colorectal cancer patients. Quantitative mRNA expression levels were normalized against the reference gene beta-actin. The results showed that adenosine kinase gene expression was significantly higher in cancer than in normal-appearing tissue, in line with our previous measurements of adenosine kinase enzyme activities in colorectal tumor samples.

Metabolic effects of nitrendipine.

A randomized, double-blind, placebo-controlled study was conducted to evaluate the safety and clinical efficacy of nitrendipine in the treatment of isolated systolic hypertension in elderly patients. The subjects were 20 elderly patients with isolated systolic hypertension who received 20 mg of nitrendipine or placebo daily for 60 days. In the nitrendipine-treated patients, both systolic and diastolic blood pressures were reduced significantly during treatment (from a mean of 180 to 155 mmHg and 92 to 80 mmHg); heart rate did not change significantly.

On the mechanism of the positive inotropy of low concentrations of strophanthidin.

The hypothesis that low concentrations of strophanthidin may decrease contractile force (and intracellular sodium activity, aiNa) under normal conditions but might increase force (while still decreasing aiNa) under conditions of increased Ca load was tested in sheep cardiac Purkinje fibers perfused in vitro. Strophanthidin was used at concentrations (7.5-25 nM, "low strophanthidin") that decreased both force and aiNa in different preparations.

On the antiarrhythmic mechanisms of magnesium in cardiac Purkinje fibers.

The antiarrhythmic actions of high [Mg]o (8 mM) were studied in sheep cardiac Purkinje fibers. At 0.1 microM, strophanthidin inhibits the Na-K pump (intracellular sodium activity aiNa and force increase) and increasing Mg shortens the action potential, decreases force and increases aiNa, as in control.

Magnesium and intracellular sodium activity in cardiac Purkinje fibers.

The actions of magnesium on intracellular sodium activity (aiNa), transmembrane potentials and contractile force were studied in sheep cardiac Purkinje fibers perfused in vitro. Increasing [Mg]o from 1.05 to 2-8 mM shortens the action potential, decreases force and increases aiNa in active (and quiescent) fibers.

Hypertension in the elderly is associated with impaired glucose metabolism independently of obesity and glucose intolerance.

We evaluated insulin secretion, insulin sensitivity and blood pressure changes after oral administration of glucose in hypertensive and normotensive elderly subjects. The hypertensive group consisted of 12 subjects (aged 72.5 +/- 1.