Determination of esterase activity of human and animal serine proteinases using fluorogenic esters of amino acids as substrates]

Two fluorogenic derivatives of amino acids are proposed as substrates for the purpose of enzymatic assay: N-benzyloxycarbonyl-phenylalanine-4-methyl umbelliferyl ester (substrate-1) and tert-butyloxycarbonyl-alanine-4-methyl-umbelliferyl ester (substrate-II). Chymotrypsin-like (hydrolysis of substrate-1), elastase-like (hydrolysis of substrate-II) esterase activity of bovine pancreatic chymotrypsin, activities of cathepsin G and elastase from human, porcine and rat neutrophils and esterase activity of human, porcine and rat serum were assayed. Differences in the level of chymotrypsin-like and elastase-like activities of human, porcine and rat serum were established. Activities of purified elastase and cathepsin G from human and animal neutrophils were shown to have no significant distinctions.     

Interactions of interferon with other immunomodulators in the regulation of human natural killer cell activity]

The cytotoxic activity of natural killer (NK) cells isolated from peripheral blood of 20 healthy donors and 34 patients with multiple sclerosis (MS) against labelled with H3-uridine target cells K-562 before and after their 1 hr treatment with reaferon (RF), T-activin (TA), myelopid (MP), opioid preparation dalargin (DL) as well as with combinations of TA, MP and DL with RF was studied in 14 hrs cytotoxic test. It has been shown that combination of RF with TA, MP and DL changed the regulatory action of these peptides on NK cell activity in healthy donors in vitro. The same combination of the preparations in patients with MS caused another changes in regulation of NK activity by them because NK cells in MS patients had had initially changed sensitivity to action of these regulatory polypeptides.     

The effect of infra-red radiation on rectal temperature and respiration rate of unacclimated female new zealand white rabbits

1. 1.|An experiment was carried out to examine the effects of various levels of infra-red (i.r.) radiation on rectal temperature (RT) and respiration rate (RR) in New Zealand While rabbits.

2. 2.|A 4 × 3 × 6 factorial design was employed in which the factors were: four intensities of i.r. radiant heating of 0.0, 1.9, 2.1 and 2.4 MJ/m²/h, three replicates and six rabbits.

3. 3.|rectal temperature differed (P < 0.05) between treatments and were highest at the “high” level of i.r. radiation (1°C higher than for controls). At the “medium” and “low” levels of i.r. heating RTs were respectively 0.3 and 0.2°C higher than in controls.

4. 4.|At different levels of radiation RR were different (P < 0.05), with the highest (422.7 ± 218.1 breaths/min) at 2.4 MJ/m²/h i.r. radiant heating. This RR was almost 2.5 times that in controls, while at the “low” and “medium” i.r. levels RR values were respectively 1.5 and 2 times those of controls.

Effects of different doses of perfluorocarbon emulsion on hemodynamics and contractility of ischemic heart]

The effect of different doses of perfluorocarbon emulsion (5, 10, and 15 ml/kg) on the hemodynamics and contractility of heart was studied on anesthetized dogs. The emulsion was introduced intravenously by the 60th minute of acute myocardium ischemia caused by partial coronary occlusion. When pO2 = 120 mm Hg, the emulsion was efficient only at doses of 10 and 15 ml/kg (an increase in cardiac ejection, in the rate of contraction and relaxation of the myocardium, reduction of vascular resistance). However, the efficiency of the emulsion at a dose of 15 ml/kg was lower, possibly, due to hypervolemia and cardiodepressive effect of introduction of excess quantity of the surface-active substance proxanol, a component of the emulsion.     

Characterization of cloned alpha-satellite sequence from the extrachromosomal DNA of HeLa cell culture]

We have obtained the alphoid DNA clones, pK1 and pK2, from the extrachromosomal DNA of Hela cells treated by cycloheximide (30 micrograms/ml). Nucleotide sequences of the clones were aligned. The sides of the pK1 and pK2 are 390 and 184 bp, respectively. The marked RELP for the clones was not observed. The results of in situ hybridization have shown an approximately equal distribution of Ag-grains over major part of human chromosomes, with a slight preference for chromosomes 1, 5 and 19 (the 1-st group of alpha-satellite DNA). Therefore, the obtained alphoid sequences seem to be rather conservative and non-chromosome-specific. We suppose that increase of the alphoid DNA content in the fraction of the extrachromosomal DNA under the cycloheximide treatment is a result of the sporadic statistical processes rather then consequence of the specific excision.     

Cyclic AMP efflux is regulated by occupancy of the adenosine receptor in pig aortic smooth muscle cells

Cultured pig aortic smooth muscle cells respond to extracellular adenosine by activating adenylate cyclase and by initiating the efflux of cAMP. In the presence of extracellular adenosine, efflux is first order with respect to intracellular cAMP concentration up to at least 125 pmol/10(6) cells. The apparent first-order rate constant for the efflux of cAMP increases in a dose-dependent manner in response to extracellular adenosine or 5-N-ethylcarboxamide adenosine. The EC50 for adenosine for promoting cAMP efflux is 12 microM. For cells stimulated with 5-N-ethylcarboxamide adenosine, the EC50 is 5 microM. When extracellular adenosine is removed, efflux stops abruptly. Cellular cAMP content falls but is still in a range that supports cAMP efflux when agonist is present. Efflux is not affected by H8 (N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride), an inhibitor of cAMP-dependent protein kinase. These data suggest that in pig aortic smooth muscle cells, the efficiency of cAMP efflux is regulated by A2 receptor occupancy.     

Rhinoplasty: the light reflexes

The physical characteristics of the light reflexes of the nasal tip are defined in large part by the studio lighting configuration. By varying the lighting configuration, it is possible to alter the light reflexes as regards their number, distance apart, symmetry, and size. For the plastic surgeon, the quarter light system of the medical photographer has definite advantages over the key light system of the portrait photographer. The quarter light system consists of two lights of equal intensity with symmetrical angles of incidence placed at 45 degrees to the camera-subject axis. Measuring changes in the light reflexes as a method of determining the efficacy of surgical techniques is valid under very controlled conditions.