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51.
YC Lo L Brett CJ Kenyon SD Morley JI Mason BC Williams 《Canadian Metallurgical Quarterly》1998,24(3-4):559-563
We have employed polyclonal antibodies to a peptide sequence of bovine steroidogenic acute regulatory (StAR) protein and human placental 3beta-hydroxysteroid dehydrogenase (3beta-HSD) to determine the localisation and distribution of these proteins in rat and bovine adrenal glands. Immunohistochemical staining demonstrated the presence of StAR protein in the zona glomerulosa (ZG), zona fasciculata (ZF), zona reticularis (ZR) and in the medulla of both species. For 3beta-HSD, immunostaining was observed in the ZG, ZF and ZR of the rat adrenal and was absent in the medulla. Immunoblotting experiments showed intense bands for StAR protein (30 kDa, 37 kDa) in the mitochondria of bovine ZG, ZF and medulla and a less intense band (30 kDa) in the microsomes. In rat ZG and ZF/R mitochondria only the 30 kDa protein was present. For 3beta-HSD, an intense band (42 kDa) was found in microsomes and mitochondria of rat and bovine ZG and ZFR. A very faint signal for 3beta-HSD was seen in adrenal medulla. In conclusion, StAR (or a closely related) protein is present throughout the adrenal gland in rat and bovine species in contrast to 3beta-HSD which is confined to the steroidogenic zones. The possible function of StAR protein in the adrenal medulla merits investigation. 相似文献
52.
WM Feinberg ES Cornell SD Nightingale LA Pearce RP Tracy RG Hart EG Bovill 《Canadian Metallurgical Quarterly》1997,28(6):1101-1106
BACKGROUND AND PURPOSE: The prothrombin time (expressed as the international normalized ratio [INR]) is the standard method of monitoring warfarin therapy in patients with atrial fibrillation. Prothrombin activation fragment F1.2 provides an index of in vivo thrombin generation and might provide a better index of the effective intensity of anticoagulation. We examined the relationship between F1.2 and INR in patients with atrial fibrillation. METHODS: We measured INR and F1.2 levels in 846 patients with atrial fibrillation participating in the Stroke Prevention in Atrial Fibrillation III study. Two hundred nineteen (26%) were taking aspirin alone, 326 (39%) were taking adjusted-dose warfarin, and 301 (36%) were taking a low fixed dose of warfarin (1 to 3 mg) plus aspirin (combination therapy). F1.2 levels were measured with an enzyme-linked immunosorbent assay. RESULTS: Patients receiving adjusted-dose warfarin or combination therapy had significantly higher INR and significantly lower F1.2 values than those on aspirin alone (P < or = .0001 for each of the four comparisons). F1.2 values (nanomolar) were inversely correlated with INR (F1.2 = -0.1 + 2.3[1/INR]; R2 = .37; P < .0001; simple linear regression). However, significant variability remained. Among patients receiving warfarin, older patients had higher F1.2 values than younger patients after adjustment for INR intensity (P < .001) in the model. There was no difference in the relationship between F1.2 and INR between men and women. CONCLUSIONS: Increasing intensity of anticoagulation, as measured by the INR, is associated with decreasing thrombin generation as measured by the F1.2 level, but significant variability exists in this relationship. Older anticoagulated patients have higher F1.2 values than younger patients at equivalent INR values. The clinical significance of these differences is not clear. F1.2 measurement might provide information regarding anticoagulation intensity in addition to that reflected by the INR. 相似文献
53.
SJ Hicks SD Carrington RL Kaswan S Adam J Bara AP Corfield 《Canadian Metallurgical Quarterly》1997,64(4):597-607
Our aims were to separate and characterize secreted canine ocular mucins, and to provide definitive evidence of membrane-bound mucins at the canine ocular surface. Mucus was collected by suction from the ocular surface of normal dogs and dispersed in guanidine hydrochloride and a cocktail of protease inhibitors. Caesium chloride density gradient centrifugation separated secreted mucins from membranes, which were collected from the top of the gradients. Membranes were extracted with octyl glucoside and screened using lectins and anti-mucin antibodies. Gradient fractions containing secreted mucins were constituted into pools on the basis of differential lectin and antibody staining. High molecular weight material from each pool was purified by gel filtration. This material, and the membrane extract, were reduced and alkylated. Vacuum blotting of separated materials after agarose gel electrophoresis was used to compare subunit structure. Density gradient profiles indicated three principal secreted glycoprotein peaks: one staining strongly with anti-mucin antibodies. Gel filtration demonstrated that each contained high molecular weight material. Vacuum blots demonstrated the presence of two secreted glycoproteins with differently sized subunits. On the basis of buoyant density, one of these may be lipid complexed. Membrane extracted material stained with anti-mucin antibodies, and vacuum blotting of this material provided evidence for two membrane-bound components. In conclusion, we have shown that normal canine ocular mucus contains two secreted mucins, each exhibiting different subunit structure; one of these mucins may undergo lipid complexation. Normal canine ocular mucus also contains two membrane-bound mucins: one of which is unique among membrane mucins in showing subunit structure. 相似文献
54.
Exposure of mammalian cells to ultraviolet (UV) light elicits a cellular response and can also lead to apoptotic cell death. In this report, we show that a 36-kDa myelin basic protein (MBP) kinase detected by an in-gel kinase assay can be dramatically activated during the early stages of UV irradiation-triggered apoptosis of A431 cells. Immunoblot analysis revealed that this 36-kDa MBP kinase could be recognized by an antibody against the C-terminal regions of a family of p21Cdc42/Rac-activated kinases (PAKs). By using this antibody and a PAK2-specific antibody against the N-terminal region of PAK2 as studying tools, we further demonstrated that UV irradiation caused cleavage of PAK2 to generate a 36-kDa C-terminal catalytic fragment and a 30-kDa N-terminal fragment in A431 cells. The appearance of the 36-kDa C-terminal catalytic fragment of PAK2 matched exactly with the activation of the 36-kDa MBP kinase in A431 cells upon UV irradiation. In addition, UV irradiation also led to activation of CPP32/caspase-3, but not ICH-1L/caspase-2 and ICE/caspase-1, in A431 cells and the kinetics of activation of CPP32/caspase-3 appeared to correlate well with that of DNA fragmentation and of cleavage/activation of PAK2, respectively. Moreover, blockage of activation of CPP32/caspase-3 by pretreating the cells with two specific tetrapeptidic inhibitors for caspases (Ac-DEVD-cho and Ac-YVAD-cmk) could significantly attenuate the extent of cleavage/activation of PAK2 induced by UV irradiation. Collectively, the results demonstrate that cleavage and activation of PAK2 can be induced during the early stages of UV irradiation-triggered apoptosis and indicate the involvement of CPP32/caspase-3 in this process. 相似文献
55.
To elucidate the mechanism of gut hypertrophy observed in rats artificially reared (AR) on milk formulas, the effects of four refined formulas with different ratios of casein (C) and whey protein (W), CW 2:8, CW 4:6, CW 6:4 and CW 8:2, on the gut growth of AR rats were examined. Four groups of pups were infused with each formula through an intragastric cannula from age 5 to 15 days. Each of the four milk formulas showed a different character in the stomach, such as no curd, very soft curd, soft curd and hard curd, in response to an increasing ratio of C:W. There were no significant differences in body weight gain among the AR groups and mother-reared (MR) controls. The stomach growth, in weight, of AR rats increased in response to the increasing ratios of C:W. In comparison with MR controls, hypertrophy of the stomach of AR rats appeared within the formulas with higher proportions of casein than whey protein (CW 6:4 and CW 8:2), but not those with lower proportions (CW 2:8 and CW 4:6). The growth of the small intestine was also related to the increasing ratio of C:W in the formulas. A similar pattern of hypertrophy in the hindgut was seen in AR rats. There was no association between hypertrophy of the gut in AR rats and plasma triiodothyronine. The present results clearly demonstrated that the gut growth of AR rat pups was directly influenced by the diet but not by AR per se, and that hard casein-curd in the stomach might be one cause of gut hypertrophy. 相似文献
56.
Seed banks and molecular maps: unlocking genetic potential from the wild 总被引:10,自引:0,他引:10
Nearly a century has been spent collecting and preserving genetic diversity in plants. Germplasm banks-living seed collections that serve as repositories of genetic variation-have been established as a source of genes for improving agricultural crops. Genetic linkage maps have made it possible to study the chromosomal locations of genes for improving yield and other complex traits important to agriculture. The tools of genome research may finally unleash the genetic potential of our wild and cultivated germplasm resources for the benefit of society. 相似文献
57.
F Hermansen SD Rosen F Fath-Ordoubadi JS Kooner JC Clark PG Camici AA Lammertsma 《Canadian Metallurgical Quarterly》1998,25(7):751-759
Positron emission tomography (PET) in conjunction with C15O2 or H215O can be used to measure myocardial blood flow (MBF) and tissue fraction (TF), i.e. the fraction of the tissue mass in the volume of the region of interest. However, with C15O2 inhalation, the tissue fraction in the septum is overestimated. Bolus injection of H215O together with arterial cannulation gives very precise results but is invasive. The purpose of this study was to develop a method which circumvents these problems. A four-parameter model with parameters for MBF, TF and spill-over fractions from both left and right ventricular cavities was developed. This method was compared with a three-parameter model (no right ventricular cavity spill-over) in both septal and non-septal regions of interest for three different administration protocols: bolus injection of H215O, infusion of H215O and inhalation of C15O2. It was found that MBF can be measured with intravenous administration of H215O without the requirement for arterial cannulation. The four-parameter protocol with bolus injection was stable in clinical studies. The four-parameter model proved essential for the septum, where it gave highly significantly better fits than did the three-parameter model (P<0.00003 in each of 15 subjects). Administration of H215O together with this four-parameter model also circumvented the problem of overestimation of TF in the septum seen with C15O2 inhalation. In addition, the radiation dose of H215O protocols is lower than that of C15O2 inhalation. Using a left atrial input curve instead of a left ventricular cavity input curve gave the same mean MBF and TF. 相似文献
58.
The objective of the present study was to evaluate the effect of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-alpha (IL-1a), on myoblast proliferation and fusion and on myocyte protein metabolism and stress protein expression. Proliferation was suppressed (p < 0.05) by both cytokines, alone and in combination, and at lower concentrations, the suppression was additive. Likewise, fusion was retarded (p < 0.05) by these cytokines alone and in combination. Myosin synthesis was not altered acutely or chronically by TNF-alpha alone or by the combination of this cytokine with IL-1alpha. Chronic exposure to TNF-alpha did not alter total cellular protein synthesis, but exposure to IL-1alpha and the cytokine combination resulted in an increase (14% to 19%, p < 0.05) in synthesis. Neither total cellular protein nor myosin degradation were influenced by either cytokine alone or by the combination. There was no detectable induction, acutely or chronically, of any of the stress proteins evaluated (HSC70, HSP70, or HSP60). These data suggest that cytokines may alter muscle growth and development prenatally and postnatally and that the changes in muscle protein metabolism during periods of immune challenge are not direct effects of TNF-alpha or IL-1alpha. 相似文献
59.
JR Eshleman PS Donover SJ Littman SE Swinler GM Li JD Lutterbaugh JK Willson P Modrich WD Sedwick SD Markowitz ML Veigl 《Canadian Metallurgical Quarterly》1998,16(9):1125-1130
We describe a novel mutator phenotype in the Vaco411 colon cancer cell line which increases the spontaneous mutation rate 10-100-fold over background. This mutator results primarily in transversion base substitutions which are found infrequently in repair competent cells. Of the four possible types of transversions, only three were principally recovered. Spontaneous mutations recovered also included transitions and large deletions, but very few frameshifts were recovered. When compared to known mismatch repair defective colon cancer mutators, the distribution of mutations in Vaco411 is significantly different. Consistent with this difference, Vaco411 extracts are proficient in assays of mismatch repair. The Vaco411 mutator appears to be novel, and is not an obvious human homologue of any of the previously characterized bacterial or yeast transversion phenotypes. Several hypotheses by which this mutator may produce transversions are presented. 相似文献
60.
HC Hung WC Chen Y Chao MC Hou HC Lin FY Chang SD Lee 《Canadian Metallurgical Quarterly》1998,93(12):2603-2604
Complication of endoscopic variceal injection sclerotherapy for esophageal variceal hemorrhage is not unusual. However, sclerotherapy complicated panophthalmitis was never reported before. We report such an unusual complication and discuss its possible mechanism and treatment. 相似文献