Comparison of enzyme phenotypes in human bladder tumours and experimentally induced hyperplastic and neoplastic lesions of the rat urinary bladder. A combined histochemical and immunohistochemical approach

The expression of a number of enzymes involved in drug metabolism, membrane function etc. was compared in hyperplastic and neoplastic lesions of the rat bladder and in human bladder tumours. Transitional cell carcinomas (TCC) in both rat and Man were characterized by decreased alkaline phosphatase (ALP) and increased gamma-glutamyl transpeptidase (GGT), beta-glucuronidase (beta-G1), succinate dehydrogenase (SD) and glucose-6-phosphate dehydrogenase (G6PD) activities. In addition, binding for antibodies specific for different cytochrome P-450 species (UT50, PB3a, MC1, MC2) and microsomal epoxide hydrolase (mEHb) was elevated in both murine and human tumours. Comparison of the enzyme phenotype in hyperplastic lesions induced by freeze ulceration or uracil administration with that in preneoplastic papillary or nodular hyperplasia (PNH) and TCC suggested, however, that most of the alteration in enzyme content or activity was non-specific and related to requirements for epithelial cell proliferation. On the other hand, the decreased ALP, and increased GGT and beta-G1 activity appeared more directly related to neoplastic transformation. The results suggested that qualitative differences exist between reactive hyperplasia and preneoplastic or neoplastic lesions in the urinary bladder. The finding of increased cytochrome P-450, in clear contrast to the reduction characteristic of preneoplastic hepatic lesions, may be important with regard to the observed difference in neoplastic transformation between the bladder and liver in response to drug metabolising enzyme inducers.     

Macrophages of the rat thymus after cyclosporin treatment. Histochemical, enzymehistochemical and immunohistochemical study

Young adult Wistar rats received 40 mg/kg of cyclosporin perorally for 21 days. Cyclosporin induced almost total disappearance of thymic medulla, whereas the cortex remained preserved. Although the density of cortical macrophages did not change significantly, their characteristics altered markedly and they became enlarged and rounded. In addition to an increase in acid phosphatase and nonspecific esterase activities, cortical macrophages developed very strong succinic dehydrogenase and chloroacetate esterase activities and a fine, granular, aldehyde fuchsin-positive cytoplasmic content. However, these cytoplasmic granules were PAS-negative and were not sudanophilic. Cortical macrophages retained their normal antigenic properties (which were studied by the use of ED1, ED2 and R-MC 41 monoclonal antibodies). Phagocytic cells in the remaining medullary islands retained their usual characteristics. The changes in cortical macrophages after cyclosporin treatment are discussed, especially in relation to the characteristics of macrophages of the cortico-medullary zone in the normal rat thymus.     

Kinetic properties of transketolase from the rat liver in a reaction with xylulose-5-phosphate and ribose-5-phosphate

An analysis of steady-state kinetics of purified rat liver transketolase shows that the reaction proceeds according to a two-stroke substitution ("ping-pong") mechanism. Based on the kinetic data, a competitive relationship was shown to exist between xylulose-5-phosphate and ribose-5-phosphate for the sites of substrate binding by the substituted form of the enzyme with the formation of a non-productive abortive complex (kd = 125 microM). The values of constants of two monomolecular steps of the reaction (k2 = 42 s-1; k4 = 9.4 s-1) were determined. It was assumed that the maximum rate-limiting step of the transketolase reaction is the degradation of the substituted form of transketolase--ribose-5-phosphate complex having a rate constant of k4.     

Energy and plastic metabolism of the heart muscle in rabbits undergoing thyroid irradiation with decimeter waves

The functional state of myocardial mitochondria, the glycogen and nucleic acid contents in myocardium, and morphometry of structural elements of cardiomyocytes and myocardial capillary network were investigated in order to select the optimal regimen of decimeter wave exposures with power density of 10, 120 and 240 mW/cm2 on the area of thyroid gland. It was shown that the thyroid gland exposure to decimeter waves at these intensities resulted in functional shifts in energy and plastic processes in myocardium and capillary blood supply. These changes increased to a considerable extent as the intensity of exposure was increasing and reached the maximum at power density of 240 mW/cm2 but event at this intensity there was not found the injurious effect of decimeter waves on the myocardium.     

The electron microscopic characteristics of stress lung

The influence of long-term (6 hours) immobilization stress on morphofunctional state of lung air-blood barrier was studied in experiments of the rats. It was shown that stress provoked the marked ultrastructural changes in the lungs, which were as follows: lung tissue oedema, pronounced thickening of lung air-blood barrier and its separate layers, edema-hemorrhagic syndrome, alveolar epithelial injury, disturbance of lung surfactant systems. Such a pathological complex may be designated as a "stress lung".     

家兔中脑导水管周围灰质中注射八肽胆囊收缩素（CCK—8）拮抗吗啡镇痛和...

We have reported that intracerebroventricular (i. c. v.) injection of 1-4 ng of CCK-8 to the rat produced a remarkable antagonistic effect on morphine analgesia. In order to study the species specificity and the site of action, CCK-8 was microinjected into the PAG of the rabbit, and its influence on morphine analgesia and electroacupuncture analgesia was observed. The latency of the escape response (ERL) to radiant heat focused on the snout was measured as an index of the pain threshold. Microinjections were made via cannulae chronically implanted into the PAG. The drug solutions were delivered in a volume of 1 microliter, at a speed of 0.125 microliter/min. The ERL was measured for a period of 60 or 70 minutes at 10 min intervals. 1. CCK-8 administered unilaterally to the PAG of the rabbit at a dose of 3 ng antagonized the analgesia induced by morphine (4 mg/kg, i. v.) by 73% (P less than 0.001), and reduced the analgesic effect of electroacupuncture by 67% (P less than 0.001). These effects were dose-dependent within the range from 1.5 ng to 6.0 ng. The effect of CCK-8 was reversed by CCK receptor blocker proglumide (4 microliters, intra-PAG injection). Unsulfated CCK-8 (CCK-us) had no effect in this regard. These results indicate that in the PAG of the rabbit, exogenously administered CCK-8 was capable of antagonizing opioid analgesia by the activation of CCK receptors. 2. Two groups of rabbits were given with morphine (2 mg/kg, i. v.) and simultaneous injection of CCK-8 antiserum (CCK-AS, 1 microliter) or normal rabbit serum (NRS) into the PAG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Importance of associated microorganisms in the development of acute pneumonia

Sputum samples obtained from 106 patients with acute pneumonia have been studied by the quantitative microbiological method. Different microbial associations have been shown to play an important role in the development of acute pneumonia (67.9%). Microbiological studies have revealed the prevalence of pneumococci in the etiological structure of the disease. Staphylococci, hemophilic bacteria and Neisseria have been found to take part in the development of acute pneumonia in a lesser number of cases and more often occur in combination with pneumococci or form different associations themselves. The so-called "etiological" type of microbial associations has been determined, two or three microbial species being isolated at high concentrations (10(6) and over) and the percentage of patients with such combinations being 59.7 +/- 5.8%. The analysis of the clinical course of the disease has revealed that the presence of different microbial species in patients linked, to a great extent, with the clinical picture of the disease. These data may be used for prescribing adequate etiotropic therapy and for prognostication. Quantitative bacteriological studies carried out in the dynamics of the disease permit timely detection of changes in the microflora of the respiratory tracts, the evaluation of the effectiveness of antibacterial therapy in the process of its implementation and the rational correction of therapeutic measures.     

The taxonomy of obligate anaerobic bacteria

Studies on the chemotaxonomy of obligate anaerobic bacteria have been made. The combination of gas chromatography and mass spectrometry with computer-assisted analysis, permitting the multicomponent analysis of all products of bacterial metabolism and bacterial cell components, has been shown to be a research method, quite suitable for such studies. The chromatographic profiles of the end products of metabolism in anaerobic cultures of different age have been found to differ not in the set and number of peaks indicating various metabolites, but only in the concentration of metabolites, increasing in the process of prolonged incubation. The authors believe that the national microbiological "library" of the chromatographic profiles of anaerobic organisms should be created and the album of typing chromatographic profiles should be published; besides, data on new profiles should regularly appear in magazines.     

NADPH:cytochrome P-450(c) reductase: Biochemical characterization in rat brain and cultured neurons and evolution of activity during development

NADPH:cytochrome P-450 (c) reductase is a microsomal enzyme which is involved in the cytochrome P-450-dependent biotransformation of many exogenous agents as well as of some endogenous molecules. Using cytochromec as a substrate, the kinetic parameters of this enzyme were determined in brain microsomes. The comparison of the NADPH:cytochrome P-450 reductase's V_max values and cytochrome P-450 contents in both fractions, suggests a role of cerebral NADPH:cytochrome P-450 reductase in cytochrome P-450 independent pathways. This is also supported by the different developmental pattern of brain enzyme as compared to the liver enzyme, and by the presence of a relatively high NADPH:cytochrome P-450 reductase activity in immature rat brain and neuronal cultures, while cytochrome P-450 was hardly detectable in these preparations. The enzyme activity was not induced by a phenobarbital chronic treatment neither in the adult brain nor in cultured neurons, suggesting a different regulation of the brain enzyme expression.