Effects of PGI2 on the inactivation of thrombin, factor Xa, and plasmin by antithrombin-III and heparin.

The influence of PGI2 on the activity and on the inactivation of enzymes participating in blood coagulation (thrombin and Factor Xa) and fibrinolysis (plasmin) were investigated. According to the results PGI2 has no effect on the activity of Factor Xa and plasmin nor on the inactivation of these enzymes by antithrombin-III in the absence and presence of heparin at a concentration of PGI2 up to 400 micrograms/ml. An acceleration of the inactivation of thrombin by antithormbin-III was found in the presence of PGI2 within a concentration of 100-400 micrograms/ml without any effect on the heparin-accelerated inactivation of thrombin by antithrombin. We got similar results using clotting tests for the assay and the application of synthetic substrate for thrombin. This inactivation-accelerating effect of PGI2 on thrombin was only demonstratable at a concentration five magnitudes higher than that of the anti-aggregation effect on platelets.     

Effects of acute and chronic ethanol on cardiac contractile protein ATPase activity of Syrian hamsters

Ethanol consumption is known to affect cardiac and skeletal muscle. In vivo experiments on cardiac muscle showed that ethanol affects cardiac contractility and Vmax, suggesting that contractile proteins of the myocardium were affected by ethanol. Therefore, experiments were carried out to examine the effects of ethanol on the cardiac contractile protein ATPase activities. Cardiac myofibrils isolated from ethanol-fed hamsters showed a significant decrease in myofibrillar ATPase activities between pCa 6 and 4. On the other hand, addition of ethanol (0.1%) in vitro to cardiac myofibrils from control hamster had no significant effect on the ATPase activities, suggesting that hamsters need to be exposed for longer periods of time to induce demonstratable changes in the contractile protein ATPase activity. Actin-activated myosin ATPase activities were significantly lower in myofibrils from ethanol-fed hamsters at 1:1 and 1:2 ratios of myosin to actin. These investigations revealed that chronic (4 weeks) exposure of hamsters to ethanol reduced cardiac contractile protein ATPase activity, which may help explain impaired cardiac function in chronic alcoholics.     

Effects of PGI2 on the inactivation of thrombin,factor Xa,and plasmin by antithrombin-III and hepartin

The influence of PGI₂ on the activity and on the inactivation of enzymes participating in blood coagulation /thrombin and Factor Xa/ and fibrinolysis /plasmin/ were investigated. According to the results PGI₂ has no effect on the activity of Factor Xa and plasmin nor on the inactivation of these enzymes by antithrombin-III in the absence and presence of heparin at a concentration of PGI₂ up to 400 μg/ml. An acceleration of the inactivation of thrombin by antithrombin-III was found in the presence of PGI₂ within a concentration of 100–400 μg/ml without any effect on the heparin-accelerated inactivation of thrombin by antithrombin. We got similar results using clotting tests for the assay and the application of synthetic substrate for thrombin. This inactivation-accelerating effect of PGI₂ on thrombin was only demonstratable at a concentration five magnitudes higher than that of the anti-aggregation effect on platelets.     

Influenza virus-specific antibody-secreting cells in the murine lung during primary influenza virus infection.

An enzyme-linked immunosorbent plaque assay is described which can reliably enumerate influenza virus-specific antibody-secreting cells and exhibits specificity similar to that of the indirect enzyme-linked immunosorbent assay. The assay was used to characterize the development of specific antibody-secreting cells, principally within lung tissue, during primary murine influenza virus infection after intranasal inoculation. Cells secreting influenza virus-specific immunoglobulin M (IgM), IgG, and IgA were detected in greatest numbers in lung tissue, and the data presented indicated that the cells may have originated from specific B-cell precursors in lung tissue which are demonstratable in vitro. At 11 months after infection, cells secreting IgG and IgA were still present in lung tissue. Influenza virus-specific antibody-secreting cells were also detected in spleen tissue and blood. Antibody-secreting cells appeared earlier in spleen than in lung tissue and declined more rapidly in spleen tissue.     

Preliminary studies on the carcinogenic effects of Penicillium roqueforti toxin (PR toxin) on rats

Preliminary results on the carcinogenic activity of a mycotoxin of Penicillium roqueforti (PR toxin) are reported. A squamous epithelioma and a uterine sarcoma were histologically confirmed in 2 of 10 albino rats fed PR toxin in a relatively short time (449 and 551 days respectively). Only an adenocarcinoma was histologically proven within a control group of 10 rats in a significantly longer (931 days) time span.     

Lesions of the hypothalamic paraventricular nucleus and norepinephrine turnover in rats

The effects of bilateral lesions of the hypothalamic paraventricular nuclei (PVN), of rats with a mean weight of 260 g body, on eating habits and body weight, as well as on sympathetic nervous system (SNS) activity in interscapular brown adipose tissue (IBAT) were investigated. In 59 of 131 Sprague-Dawley female rats, PVN lesions resulted in hyperphagia and obesity. Although lesions were considered successful when more than 50% of the PVN was destroyed histologically, such lesions were observed in 35.9% (47/131) of all lesioned rats and all of these 47 rats were obese. Therefore, in this study, these 47 rats which were confirmed histologically, were designated as "PVN-lesioned rats". Plasma insulin levels in these 47 PVN-lesioned ats were more than double those of the controls. However, no significant differences were observed between plasma glucose levels in PVN-lesioned and control groups. Norepinephrine turnover, a reliable indicator of SNS activity, in IBAT, heart and pancreas was similar in PVN-lesioned and sham-operated control animals, even under contrasting conditions of feeding (ad libitum and fasting) and temperature (22 degrees C and 4 degrees C). It is concluded that PVN lesions produce hyperphagia, obesity and hyperinsulinemia in rats with an average body weight of 260g without affecting the SNS activity in IBAT, heart or pancreas.     

A method for the direct demonstration of the lectin-binding components of the human erythrocyte membrane.

1. A method which allows the characterization of lectin-binding components is described. This method should be useful in defining the nature and heterogeneity of these components in cell membranes. 2. The method, which we have used on erythrocyte "ghosts", involves the fixation of "ghost" components after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and incubation with purified 125I-labelled lectins. 3. Each of the four lectins used shows an individual pattern of reactivity towards "ghosts" components. Band 3, the major membrane-penetrating glycoprotein, is bound by the lectins from Ricinus communis and Phaseolus vulgaris (phytohaemagglutinin) and by concanavalin A. The major erythrocyte sialoglycoprotein is bound by the lectins from R. communis, P. vulgaris and Maclura aurantiaca. 4. Three of the lectins displays binding for other membrane components, some of which are not demonstratable by conventional protein- and carbohydrate-staining techniques.     

大鼠小肠移植后一氧化氮合酶组织化学观察

监测大鼠小肠移植后一氧化氮合酶的变化与排斥反应的关系以及肝小肠联合移植与单纯小肠移植后的变化异同。两组移植后分别于１、３、７……天同时取肠壁病理和组织化学标本对比,病理为常规ＨＥ染色观察, 一氧化氮合酶（ＮＯＳ） 组织化学检查按Ｄａｗ ｓｏｎ 方法显示其活性。结果两组肠壁ＮＯＳ的活性随移植后排斥反应加重而降低或消失, 单纯小肠移植比肝小肠联合移植变化明显。大鼠小肠移植后肠壁内ＮＯＳ变化与排斥反应相关, ＮＯ 可以作为小肠移植后监测排斥反应的参考指标之一     

Prolactin and Growth Hormone Binding in Mammary and Liver Tissue of Lactating Cows

Abstract

A radioligand/receptor binding assay was developed using homologous hormones to distinguish between bovine growth hormone (bGH) and bovine prolactin (bPRL) receptors in liver and mammary tissue of lactating cows. Mammary and liver tissues were homogenized in 0.3 M sucrose and centrifuged at 100,000 x g over a 1.3 M sucrose density gradient. Membranes from the 0.3 - 1.3 M sucrose interface were incubated with 1 ng of iodinated bGH or bPRL for 20 h at 22°C in the presence of increasing concentrations of native bGH or bPRL. High affinity receptor binding sites were found for bPRL in liver and mammary tissue membranes (Ka=3.2 and 1.3 × 10⁸ 1/mol with 34 and 63 fmol receptors/mg liver and mammary membrane protein, respectively) and for bGH only in liver tissue (Ka=1.8 × 10⁹ 1/mol, 18 fmol receptors/mg membrane protein). Receptor number estimates were 3 and 11 times higher in mammary and liver tissue using a heterologous hGH system indicating that heterologous systems may overestimate the number of receptors in bovine tissue. The absence of demonstratable bGH receptors in lactating bovine mammary tissue supports in vitro results of others with isolated mammary tissue indicating that the positive effect of bGH on milk production in intact cows is via an indirect mechanism.     

EEG changes and platelet aggregation in experimental cerebral focal ischemia in rabbits

Nine white New Zealand rabbits were submitted to internal carotid embolization with microspheres which caused a histologically verified focal cerebral ischemia. Six animals were sham-operated. EEG, QEEG, ECG, blood pressure, rectal temperature and platelet aggregation were monitored in basal conditions and one hour after ischemia. Embolized animals showed an increase in power density spectrum (PDS) and delta activity (0.15-3.70 Hz) and the appearance of platelet aggregation. The QEEG changes were correlated to the degree of platelet aggregation after ischemia.     

Diurnal rhythm of the reproductive activity of cells and the functional morphology of the adenohypophysis of rats (histological and the autoradiographic study)]

The adenohypophysis of intact mongrel male rats was studied histologically and autoradiographically. The diurnal periodicity was revealed and the successive spikes of indices of the DNA synthesis, mitotic process and secretory activity of the adenohypophysis cells were established. The maximum amount of the dividing cells was found about 12 o'clock p. m.-at the period of the least secretory and synthetizing activity of the gland.     

Architecture of implanted bone matrix gelatin influences heterotopic calcification and new bone formation

Heterotopic bone formation in skeletal muscle induced by compacted demineralized bone matrix gelatin (BMG) was studied histologically and biochemically. BMG was obtained by dehydrating diaphyseal shafts of femora and tibiae of 4-week-old male Sprague-Dawley rats, cutting the bone into chips, and demineralizing and extracting the chips with various solutions. The BMG was treated with 4 M guanidine-HCl, and compacted BMG was prepared by centrifugation. The compacted BMG was implanted into the rectus abdominis muscle of 5-week-old male Sprague-Dawley rats. The resulting specimens were examined histologically, and their alkaline phosphatase activity and the calcium content of the tissues were measured 3, 5, 7, 10, and 15 days after implantation. The BMG (separated BMG) with 75- to 500-microns particle sizes were implanted into control rats. The results showed that calcification, alkaline phosphatase activity, and bone formation were suppressed by implantation of the compacted BMG and that scarcely any vascularization occurred. Calcification, vascularization, and alkaline phosphatase activity were related and were indispensable for bone formation. In the control group, bone formation was observed at sites of high activity of alkaline phosphatase and well-developed vascularization. These results suggested that compacting of BMG suppressed vascularization, decreased calcification, and consequently reduced the induction of bone formation.     

Morphologic changes of the pancreas in hemorrhagic shock and the postresuscitation period

The canine pancreas (20) in the terminal period of hemorrhagic shock and postresuscitation period was studied histologically and electronmicroscopically. There were detected ultrastructural signs of the plasmatic membranes of pancreatocytes and membranes of secretory granules with "leakage" of pancreatic ferments in the interstitial tissue. The incretion of pancreatic ferments in the vascular bed is conditioned by the elevation of proteolytic activity of blood serum in hemorrhagic shock and postresuscitation period.     

Microanatomical and biological aspects of bacterial associations in Tyrophagus putrescentiae (Acari: Acaridida)

The occurrence of bacterial colonies in the mesenchymal tissue of Tyrophagus putrescentiae Schrank was studied. One algal and two fungal species were offered as food. The experiment was analysed histologically and via transmission electron microscopy and plating of the mite homogenate. The dominant bacterium species, the bacterium population density in the mesenchyme, the location of bacterium groups between the internal organs and the ultrastructure were investigated. There were conspicuous differences between food types tested. On Penicillium, the highest population of bacteria in the mesenchymal tissue was correlated with the chitinase activity in mite homogenate. In this homogenate, Serratia marcescens was highly dominant among the other plated bacteria and it exhibited strong chitinolytic and trehalolytic activity.     

Cytochemical study of acid phosphatase activity in the functional and degenerating spinning gland cells of Pericallia ricinii (lepidoptera).

A study of the presence, distribution and activity of acid phosphatase has been carried out in the cells of the spinning gland of moth pest Pericallia ricinii in sequential larval, prepupal and pupal stages. Acid phosphomonoesterase activity at first appears in the apical and basal regions of the secretory cells of second instar larva and later in the following stages is localised in the middle region of the cells. The highest activity was found while using an incubation time from 25 to 30 minutes. Prolonged incubation resulted in artifacts. Based on the acid phosphatase activity two cell types (A and B) in the spinning gland cell layer could be distinguished. The cytochemical differences in histologically similar cells of the spinning gland of the Indian moth pest were reported for the first time. In pupal period progressive deformation could be observed in the gland cells, which is accompanied by high acid phosphatase activity, which is in contradistinction to cells with small deformations and low enzyme activity. The process of degeneration in former cells is also quicker than in the latter ones.     

Evidence for amylase in avian salivary glands

Four glands of the house sparrow, chicken and turkey were examined histologically and for their content of amylase. These were the external and intermediate mandibular glands, the maxillary gland and glandula anguli oris of the sparrow and the anterior and posterior mandibular, maxillary and anguli oris glands of the chicken and turkey. Amylase was determined by a starch substrate slide method and by biochemical assay. General morphology and mucopolysaccharide staining are described. All four glands of the sparrow demonstrated significant amylolytic activity by the assay. In the external mandibular and anguli oris glands this activity could be traced to mucous and seromucous cells of origin by means of the starch substrate slide procedure. None of the glands of the chicken or turkey displayed significant amylolytic activity.     

Evaluating Mitotic Activity in Canine and Feline Solid Tumors: Standardizing the Parameter

Three different methods for evaluating mitotic activity (mitotic count, mitoses/area, mitotic index) were applied to different types of canine and feline solid tumors to determine the method that is most objective and correlates best with other parameters of cell proliferation. Mitotic activity was evaluated on toluidine blue stained his-tological sections. Slides stained with histochemical (AgNOR proteins) and im-munohistochemical (MEB1, PCNA) markers of cell proliferation were available for each case. Quantitation of mitotic activity and cell proliferation parameters was performed with an image analyzer. Mitotic activity assessment was compared with cell proliferation indices and its ability to discriminate tumors grouped on histologically based criteria including the histological type, malignant or benign characteristics, and grade. A significant correlation by linear regression analysis with other parameters assessing cell proliferation revealed that mitotic index correlated 100% and mitoses/area and mitotic count correlated 40% of the time. In discriminating the proliferative activity of tumors grouped by histological criteria, mitotic index and mitotic count revealed 100% concordance with the other parameters of cell proliferation, while mitoses/areas showed 80% concordance.     

Indices of protein kinase activity and the problem of biochemical diagnosis of malignant growth

Protein kinase, cAMP-dependent and casein kinase activities and the ratio of these activities were determined in normal and neoplastic tissues of the colonic mucosa. Substantial activation of casein kinase and an appropriate decrease in the activity ratio of the enzymes were revealed in the malignant tissue. Protein kinase activity changed in a similar fashion in the histologically intact mucosa located 25-30 cm from the center of the tumor. The data obtained are suggestive of the possibility of using the above-indicated findings for the biochemical diagnosis of malignant neoplasms.