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41.
Using cultured cells from bovine and rat aortas, we have examined the possibility that endothelial cells might regulate the growth of vascular smooth muscle cells. Conditioned medium from confluent bovine aortic endothelial cells inhibited the proliferation of growth-arrested smooth muscle cells. Conditioned medium from exponential endothelial cells, and from exponential or confluent smooth muscle cells and fibroblasts, did not inhibit smooth muscle cell growth. Conditioned medium from confluent endothelial cells did not inhibit the growth of endothelial cells or fibroblasts. In addition to the apparent specificity of both the producer and target cell, the inhibitory activity was heat stable and not affected by proteases. It was sensitive flavobacterium heparinase but not to hyaluronidase or chondroitin sulfate ABC lyase. It thus appears to be a heparinlike substance. Two other lines of evidence support this conclusion. First, a crude isolate of glycosaminoglycans (TCA-soluble, ethanol-precipitable material) from endothelial cell-conditioned medium reconstituted in 20 percent serum inhibited smooth muscle cell growth; glycosaminoglycans isolated from unconditioned medium (i.e., 0.4 percent serum) had no effect on smooth muscle cell growth. No inhibition was seen if the glycosaminoglycan preparation was treated with heparinase. Second, exogenous heparin, heparin sulfate, chondroitin sulfate B (dermatan sulfate), chondroitin sulfate ABC, and hyaluronic acid were added to 20 percent serum and tested for their ability to inhibit smooth muscle cell growth. Heparin inhibited growth at concentrations as low as 10 ng/ml. Other glycosaminoglycans had no effect at doses up to 10 μg/ml. Anticoagulant and non- anticoagulant heparin were equally effective at inhibiting smooth muscle cell growth, as they were in vivo following endothelial injury (Clowes and Karnovsk. Nature (Lond.). 265:625-626, 1977; Guyton et al. Circ. Res. 46:625-634, 1980), and in vitro following exposure of smooth muscle cells to platelet extract (Hoover et al. Circ. Res. 47:578-583, 1980). We suggest that vascular endothelial cells may secrete a heparinlike substance in vivo which may regulate the growth of underlying smooth muscle cells.  相似文献   
42.
The comparative study of intratracheal and intravenous effect of administration of heparin on blood clotting and mast cell population condition was carried out in experiments. Unlike intravenous bolus injection of heparin, which induced fast short-time inactivation of all enzyme clotting factors, a single intratracheal injection inactivated "internal" rout of thrombin production. It was shown, that long-term hypocoagulability effect and inhibition of factors of blood coagulation after intratracheal administration of heparin correlated with accumulation of heparin in mast cell.  相似文献   
43.
Seven families with translocations t(11; 22) identified at our Institute and analysis of the literature showed that the imbalance resulted from such translocations is always due to nondisjunction 3:1. Nondisjunction occurs more often in the 1st meiotic division, and is more rare in the second one. Expressed prezygotic selection against spermia with an additional chromosome greatly increases the risk of having an imbalanced child for the women-carriers as compared to men-carriers. The phenotype of the patients with +der(22)t(11; 22) is composed of the features characteristic for trisomy 22q (cleft lip and palate, preauricular papillomas and fistulas, rectal atresia or stenosis) and trisomy 11q (long philtrum with the upper lip hanging over, renal al; asia and hypoplasia). Diaphragmatic hernias are found to be common for the patients with +der(22)t(11; 22).  相似文献   
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Two hundred forty-three isolates of alfalfa nodule bacteria (Sinorhizobium meliloti) were obtained from legume nodules and soils sampled in the northern Aral region, experiencing secondary salinization. Isolates obtained from nodules (N isolates) were significantly more salt-tolerant than those from soils (S isolates) when grown in a liquid medium with 3.5% NaCl. It was found that wild species of alfalfa, melilot, and trigonella preferably formed symbioses with salt-tolerant nodule bacteria in both salinized and nonsalinized soils. Only two alfalfa species, Medicago falcata and M. trautvetteri, formed efficient symbioses in soils contrasting in salinity. The formation of efficient symbiosis with alfalfa in the presence of 0.6% NaCl was studied in 36 isolates (N and S) differing in salt tolerance and symbiotic efficiency. Fifteen isolates formed efficient symbioses in the presence of salt. The increase in the dry weight of the plants was 25-68% higher than in the control group. The efficiency of symbiotic interaction under salinization conditions depended on the efficiency of the isolates under standard conditions but did not correlate with the source of nodule bacteria (soil or nodule) or their salt tolerance. The results indicate that nodule bacterium strains forming efficient symbioses under salinization conditions can be found.  相似文献   
47.
The synthesis of asymmetric meso-aryl-substituted porphyrins containing three 4-methoxycarbonylphenyl groups, and as a forth substituent 4-hydroxyphenyl or 4-hydroxy-3- methoxyphenyl radicals, or the isomeric 3- and 4-pyridyl substituents is described. O-alkyl derivatives of 4-hydroxyl residue are obtained. The ytterbium complexes ofthese porphyrins were synthesized and studied their luminescence spectral properties were studied. A significant difference in the lifetimes of the excited state ofytterbium complexes of esters and acids of asymmetric porphyrins is demonstrated.  相似文献   
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The synthesis of natural and synthetic porphyrin complexes with Pt, Pd, Rh, and Ru is reported. Their electronic absorption spectra, phosphorescence spectra, and lifetimes at room temperature both in the presence and in the absence of oxygen were studied. It has been shown that the variation of the nature of the central metal atom and of the substituents in pyrrole and phenyl rings allows the obtaining of metalloporphyrins with various phosphorescence excitation and phosphorescing emission spectra at room temperature. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru.  相似文献   
50.
We found that thionyl chloride can chlorinate porphyrin complexes with transient metals (Pd, Ni, or Cu) at the free beta- and meso-positions of the porphyrin macrocycle. A more prolonged or rigorous treatment also causes the chlorination of side alkyl substituents, mainly, methyl groups.  相似文献   
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