Sources of Reactive Oxygen and Nitrogen Species in Tissue Microenvironment of Hernioplasty Materials.

Titanium and polypropylene mesh endoprostheses were implanted into the rat abdominal cavity and the populations of cells migrating to their surface were analyzed. On both materials, the cells were presented mainly by macrophages that proliferated, activated, and fused to form multinuclear cells. Contact with the foreign surface triggered superoxide anion generation and myeloperoxidase synthesis by macrophages (these processes were more intense on polypropylene implants than on titanium ones) and stimulated production of nitric oxide by macrophage. It was hypothesized that the effects of free nitrogen and oxygen radicals lead to oxidation and destruction of the polypropylene endoprosthesis surface.

[Modification of the method of trypsin esterase activity determination]. / Modifikatsiia metoda opredeleniia ésteraznoi aktivnosti tripsina.

Determination of esterase activity of trypsin in blood serum using the Erlanger's method leads to overestimation of enzyme activity due to the increased "dimness" of the reaction medium. V. A. Shaternikov suggested a correction, which is based on the use of the two-wavelength registration method. But this correction does not eliminate this secondary factor completely. So for the clearing of the solutions we offer to stop the reaction by putting tubes into ice followed by subsequent centrifugation the investigated samples at 0 degree C for 15 min, at 25,000 g. It gives the possibility to measure an actual increase of an optical density in accordance to the hydrolysis of the substrate. The results of the measuring of an esterase activity of trypsin are represented in a serum and in a peritoneal exudate of dogs with an acute experimental pancreatitis. The serum esterase activity of trypsin in a was not found in intact animals. Three hours after induction of pancreatitis trypsin activity was detected only in blood serum of two of seven animals [approximately 3.6 mmole/(min-l)]. Rats with acute pancreatitis also had very low esterase activity of trypsin in blood [0.38 +/- 0.16 mmole/(min-l)] that insignificantly deferred from the control. These data question applicability of this method for diagnostics of acute pancreatitis. The estarse activity of trypsin detected in blood and peritoneal exudate, does not indicate its proteolytic activity, because it was insensitive to soybean trypsin inhibitor.

Generation of free oxygen radicals in the pathogenesis of experimental acute reflux pancreatitis.

In dogs with acute reflux pancreatitis specific activity of superoxide dismutase in the pancreas rapidly increased (over 15 min). Activation of this enzyme by free oxygen radicals was demonstrated in in vitro experiments. Treatment with allopurinol prevented activation of superoxide dismutase. Our results indicate that superoxide ions are generated in the pancreas at the early stage of acute reflux pancreatitis due to activation of xanthine oxidase.

Free radical oxidation and activity of enzymes catalyzing biotransformation of xenobiotics in the liver of rats with experimental acute pancreatitis.

The development of experimental acute pancreatitis in rats was accompanied by intensification of lipid peroxidation, activation of superoxide dismutase and glutathione reductase, inhibition of glutathione transferase, and deceleration of aniline N-hydroxylation by cytochrome P-450 in the liver. Antioxidants inhibited lipid peroxidation and antioxidant enzymes, but did not prevent inhibition of detoxifying enzymes.

[The level of malone dialdehyde in blood plasma as a manifestation of hepatic function in pilots of various professional categories]. / Uroven' malonovogo dial'degida plazmy krovi kak pokazatel' funktsional'nogo sostoianiia pecheni u letchikov razlichnykh professional'nykh kategorii]

Plasma levels of malone dialdehyde (MDA) were measured in flyers of various professional categories and persons who had no flight experience in normal conditions and shortly after a hypobaric hypoxia trial (30 min., P = 405 mm Hg, ascent and descent at 15-20 m/s), and after 24 hours of reoxygenation. In essentially healthy and highly adapted to periodic hypoxia flyers of the military transport aviation MDA remained within the normal range whereas in some subjects without flight experience displayed a significant increase in MDA levels during hypoxia and/or reoxygenation. Elevated baseline values and a material rise in MDA were also found in flyers whose blood bilirubin was above 20 mumol/L. The detoxicating function of the liver was disturbed in this category. A similar instability of the blood MDA is characteristic of subjects with hypertension, cranial traumata and obesity.

[Structural-metabolic manifestations of the cardiotoxic effect of EDTH]. / Strukturno-metabolicheskie proiavleniia kardiotoksicheskogo éffekta EDTG.

Rat myocardia exposed to 4-month inhalation of ethyl ether of 3,3-dimethyl-4,4,6-trichloro-5-hexanoic acid were studied by biochemical, morphometrical, and ultrastructural stereological methods. Long-term contact with the agent was shown to lead to myofilament regeneration impairment, resulting in a decrease in the volume density of contractile structures and in atrophy of some cardiomyocytes, which remained within 7 months of postexposure. Parallel to myofibrillar destructive alterations, there was an activation of the energy-generating compartment, which reached its maximum 1 month following the experiment and followed by mitochondrial alterations and lower SDH activity. It is concluded that the degenerative changes in cardiomyocytes are primarily associated with the functional overload and depletion of mitochondrial resources.

[Ultrastructure of the smooth muscle cells of the femoral artery in rats exposed to vibration]. / Ul'trastruktura gladkomyshechnykh kletok bedrennoi arterii krysy pod deistviem vibratsii.

Electron microscopic study of femoral arteries of white rats exposed to prolonged general vibration at a frequency of 100 Hz with an amplitude of 0.5-0.7 mm has been performed. Light and dark smooth muscle cells, as well as unchanged cells have been found in the vascular media of experimental animals. Light cells are swollen with destroyed myofilaments and great number of microtubules in cytoplasm. Dark cells are characterized by coagulation necrosis and melting of myofilaments. Vibration was shown to cause marked structural changes in smooth muscle cells mitochondria: destruction of internal and external membranes, increasing matrix osmophilia or swelling of mitochondria accompanied by crista fragmentation, as well as matrix clarification and disappearance. Morphometric analysis indicates a considerably decreased energy production by smooth muscle cell mitochondria. It has been concluded that vibrations have a damaging effect on medial smooth muscle cells of the femoral artery in the experimental animals.