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1.
The fine structure of the female gonad of Varroa jacobsoni is described. There are two components: the ovary proper and the so-called lyrate organ. The ovary is the place where oocytes mature, embedded in a supporting tissue composed of two cell types: somacells 1 and somacells 2. The lyrate organ has a nutrimentary function and is comprised of two components: supporting cells and nutritive tissue. The supporting cells are similar to the somacells 2 in that they contain abundant microtubules. The nutritive tissue is an extensive syncytium. It is connected with the oocytes via intercellular bridges, the nutritive cords. Oocytes and nutritive tissue are thought to have derived from common stem cells. From fine structural evidence it is concluded that ribosomes are one of the most important components to be transported via the nutritive cords into the oocytes. However, an increase in number of mitochondria in the middle-stage oocytes may also be a consequence of transport of these organelles from the nutritive tissue into the oocytes. Further characteristics make plausible that the interdependences of oocytes and nutritive tissue are comparable to those found in meroistic ovarioles of insects. The somatic components do not seem to be as important as the follicle cells of insects, however. It is assumed that the evolution of a nutrimentary oogenesis speeds up embryogenesis. Thus, the differentiation of the female gonad of Varroa jacobsoni may have facilitated the species' adaptation to a development completed in a short and limited time within the shelter of the covered brood cell of the bee. 相似文献
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Different methods of assessing ketone body concentrations in blood and plasma of ketoacidotic patients have been compared. We confirmed that Ketostix reacts strongly with acetoacetate, giving a useful range of 0 to 10 mM for plasma acetoacetate, that acetone reacts weakly, and that 3-hydroxybutyrate does not react at all. Plasma Ketostix readings correlated only moderately well with enzymatically determined whole-blood acetoacetate. All samples giving a + + + reaction contained more than 1·6 mM acetoacetate while only 4 out of 21 samples showing 0 contained more than 0·4 mM. Comparison of Ketostix readings with total blood ketone body content showed poor correlation. One reason for this was the large variation in the ratio of 3-hydroxybutyrate to acetoacetate in ketoacidosis; another was that often Ketostix had been stored in such a way that they had become damp, which impairs their reliability. If the Ketostix reading and estimation of the blood pH show a discrepancy we suggest that an enzymatic assay should be used to determine the ketone bodies and lactate. 相似文献
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M Mondelli G M Vergani A Alberti D Vergani B Portmann A L Eddleston R Williams 《Journal of immunology (Baltimore, Md. : 1950)》1982,129(6):2773-2778
Peripheral blood T lymphocytes from 21 patients with chronic HBV infection were incubated with autologous hepatocytes in a microcytotoxicity assay. Cytotoxicity was significantly increased in 13 cases, and in 12 of these the cytotoxic effect of the T lymphocytes was inhibited by preincubating the liver cells with IgG containing antibodies to the hepatitis B core antigen (HBcAg). Normal human IgG and IgG containing antibodies to the hepatitis B surface antigen (HBsAG) were without effect. Control experiments using autologous fibroblasts as target cells showed low levels of T cell cytotoxicity and no blocking effect of anti-core antibody. All patients in whom it was possible to demonstrate HBcAg in liver tissue had significantly increased T cell cytotoxicity to autologous hepatocytes. These studies suggest that T cell cytotoxicity in patients with chronic HBV infection is directed against determinants resembling the hepatitis B core antigen on the plasma membrane of hepatocytes. 相似文献
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Elke EM Brouwers Alwin DR Huitema Jos H Beijnen Jan HM Schellens 《BMC clinical pharmacology》2008,8(1):7
Background
The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin. 相似文献8.
Carla Cacciotto Maria Filippa Addis Daniela Pagnozzi Bernardo Chessa Elisabetta Coradduzza Laura Carcangiu Sergio Uzzau Alberto Alberti Marco Pittau 《BMC microbiology》2010,10(1):225
Background
Mycoplasmas are the simplest bacteria capable of autonomous replication. Their evolution proceeded from gram-positive bacteria, with the loss of many biosynthetic pathways and of the cell wall. In this work, the liposoluble protein complement of Mycoplasma agalactiae, a minimal bacterial pathogen causing mastitis, polyarthritis, keratoconjunctivitis, and abortion in small ruminants, was subjected to systematic characterization in order to gain insights into its membrane proteome composition. 相似文献9.
R D Leslie H P Volkmann M Poncher I Hanning H Orskov K G Alberti 《BMJ (Clinical research ed.)》1986,293(6551):840-842
Non-insulin dependent diabetes appears to be an inherited condition. A study of young offspring of non-insulin dependent diabetics was conducted to determine whether metabolic abnormalities could be found at a young age before clinical diabetes developed. Thirteen patients with non-insulin dependent diabetes were selected who fulfilled the following criteria: they had a sibling who also had non-insulin dependent diabetes, their spouse was non-diabetic, and the offspring were aged between 12 and 45 years, not diabetic, and available for study. All 32 offspring had a 75 g oral glucose tolerance test, and results in 13 of them, one randomly selected from each family, were compared with 13 controls of similar age, sex, and weight. The offspring had significantly higher fasting concentrations of glucose, higher proportions of haemoglobin A1, and higher concentrations of insulin, C peptide, and glucagon. After glucose challenge the increases in both glucose and C peptide concentrations were significantly greater in the offspring. These differences were maintained in all 32 offspring when compared with 18 controls of similar age, sex, and weight; seven of the 32 offspring had impaired glucose tolerance. These results indicate that young offspring of selected non-insulin dependent diabetics can show extensive metabolic changes including impaired glucose tolerance. These changes are associated with hyperinsulinaemia and hyperglucagonaemia. 相似文献
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