The relationship of the theophylline concentration in the saliva and the blood serum in patients with a broncho-obstructive syndrome

Theophylline salivary and serum concentrations (Tser and Tsal) were quantified after a single dose administration of theophylline drugs: euphylline (2.4% solution, 10 ml i.v. jet and 0.15 orally), theo-dur, retaphil, theopek, theobilong (0.3 g orally). The drugs were given to patients with broncho-obstructive syndrome. The samples were obtained within 6 and 24 hours upon administration for euphylline and other drugs, respectively. Tser and Tsal were determined at high-performance liquid chromatography. The authors revealed a linear relationship between Tser and Tsal in different time intervals. The percentage factors and formulas of Tser calculation by its Tsal values have been estimated.     

Progression of heart failure: a role for interstitial fibrosis

Progressive deterioration of left ventricular (LV) function is a characteristic feature of the heart failure (HF) state. The mechanism or mechanisms responsible for this hemodynamic deterioration are not known but may be related to progressive intrinsic dysfunction, degeneration and loss of viable cardiocytes. In the present study, we tested the hypothesis that accumulation of collagen in the cardiac interstitium (reactive interstitial fibrosis, RIF), known to occur in HF, results in reduced capillary density (CD = capillary/fiber ratio) and increased oxygen diffusion distance (ODD) which can lead to hypoxia and dysfunction of the collagen encircled myocyte. Studies were performed in LV tissue obtained from 10 dogs with chronic HF (LV ejection fraction 26 +/- 1%) produced by multiple sequential intracoronary microembolizations. In each dog, CD and ODD were evaluated in LV regions that manifested severe RIF (volume fraction 16 +/- 2%) and in LV regions of little or no RIF (volume fraction 4 +/- 1%). In regions of severe RIF, CD was significantly decreased compared to regions of no RIF (0.92 +/- 0.02 vs. 1.05 +/- 0.03) (P < 0.003). Similarly, ODD was significantly increased in regions of severe RIF compared to regions of no RIF (15.3 +/- 0.4 vs. 12.2 +/- 0.3 microns) (P < 0.001). These data suggest that in dogs with chronic HF, constituent myocytes of LV regions which manifest severe RIF may be subjected to chronic hypoxia; a condition that can adversely impact the function and viability of the collagen encircled cardiocyte.     

Calculation of the conformation of stereo-regular, double-spiral polynucleotides

By the step-by-step selection method energetically optimal conformation of double-stranded polynucleotides were calculated proceeding from the conformations of mono-and dinucleotides. These structures were found to belong to the families of DNA A and B forms. The dependence of six torsion angles of the polynucleotide chain on the glycosidic angle chi was investigated. As a result certain areas admitting of double-helix polynucleotides with sugar C3-endo with chi = -80 degrees were established.     

Microwave irradiation influences on the state of human cell nuclei

Changes of electrokinetic properties of cell nuclei and the quantity of granules of heterochromatin located near the nuclear envelope in nuclei of human buccal epithelium cells were studied under the influence of electromagnetic fields in vitro. Irradiation of cells was realized by means of a semiconductor generator of millimeter radiation (wavelength 7.1 mm, frequency 42.2 GHz), the Yav-1 apparatus for extremely high frequency therapy. It was shown that irradiation of cells induced a decrease in electric charge of native human buccal epithelium cell nuclei and an increase in chromatin condensation in nuclei. The observed effects depend on irradiation dose and individual peculiarities of donors.