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41.
NJ Yousif WW Dzwierzynski JR Sanger HS Matloub 《Canadian Metallurgical Quarterly》1998,102(7):2431-2435
This case report describes the use of a single lateral arm flap sequentially transferred to two defects in a bilateral hand injury. We believe this is a novel approach in reconstructing defects in bilateral hands when a staged reconstruction is planned. 相似文献
42.
A Nighorn NJ Gibson DM Rivers JG Hildebrand DB Morton 《Canadian Metallurgical Quarterly》1998,18(18):7244-7255
The nitric oxide (NO)-cGMP signaling system is thought to play important roles in the function of the olfactory system in both vertebrates and invertebrates. One way of studying the role of NO in the nervous system is to study the distribution and properties of NO synthase (NOS), as well as the soluble guanylyl cyclases (sGCs), which are the best characterized targets of NO. We study NOS and sGC in the relatively simple and well characterized insect olfactory system of the hawkmoth, Manduca sexta. We have cloned Manduca sexta nitric oxide synthase (MsNOS) and two sGCs (MsGCalpha1 and MsGCbeta1), characterized their basic biochemical properties, and studied their expression in the olfactory system. The sequences of the Manduca genes are highly similar to their mammalian homologs and show similar biochemical properties when expressed in COS-7 cells. In particular, we find that MsGC functions as an obligate heterodimer that is stimulated significantly by NO. We also find that MsNOS has a Ca2+-sensitive NO-producing activity similar to that of mammalian neuronal NOS. Northern and in situ hybridization analyses show that MsNOS and the MsGCs are expressed in a complementary pattern, with MsNOS expressed at high levels in the antennae and the MsGCs expressed at high levels in a subset of antennal lobe neurons. The expression patterns of these genes suggest that the NO-sGC signaling system may play a role in mediating communication between olfactory receptor neurons and projection neurons in the glomeruli of the antennal lobe. 相似文献
43.
JD Slater LT Yonemoto CJ Rossi NJ Reyes-Molyneux DA Bush JE Antoine LN Loredo RW Schulte SL Teichman JM Slater 《Canadian Metallurgical Quarterly》1998,42(2):299-304
The suppression of apoptosis may contribute to the carcinogenicity of the peroxisome proliferators (PPs), a class of non-genotoxic rodent hepatocarcinogens. Our previous work demonstrated that the PP nafenopin suppressed both spontaneous and transforming growth factor beta1 (TGFbeta1)-induced hepatocyte apoptosis both in vivo and in vitro. Here, we extend these observations by demonstrating the ability of nafenopin to suppress apoptosis induced by other major candidates for the signalling of cell death in the liver. Treatment of rat or mouse hepatocyte monolayers with TGFbeta1 or the DNA damaging drugs etoposide or hydroxyurea induced high levels of apoptosis. Western blot analysis did not support a role for either p53 or p21waf1 in etoposide-induced apoptosis in rat hepatocytes. Treatment of mouse hepatocytes with an agonistic anti-Fas antibody also resulted in an induction of high levels of apoptosis. Pre-addition and continued exposure to nafenopin suppressed apoptosis induced by all three stimuli. Overall, our studies demonstrate that the ability of nafenopin to protect hepatocytes from apoptosis is not restricted to species or apoptotic stimulus. It is possible, therefore, that the PPs may suppress apoptosis by acting on diverse signalling pathways. However, it seems more likely that nafenopin suppresses hepatocyte apoptosis elicited by each death stimulus by impinging on a core apoptotic mechanism. 相似文献
44.
XF Zhao T Colaizzo-Anas NJ Nowak TB Shows RW Elliott PD Aplan 《Canadian Metallurgical Quarterly》1998,47(2):319-322
OBJECTIVE: We prospectively compared the ability of two techniques--bone scintigraphy with single-photon emission computed tomography (SPECT) of the chest and CT of the chest--to reveal potential osteosarcoma metastases of the lung. SUBJECTS AND METHODS: Our study included 27 patients with osteosarcoma who prospectively underwent both bone scintigraphy with SPECT of the chest and CT of the chest. The imaging results were compared with outcome or pathologic analysis of any lung lesions found. RESULTS: Eight (30%) of the 27 patients had pulmonary metastases. Four of these eight patients had positive results on both CT studies and bone SPECT studies, with additional lesions detected with bone SPECT in two of these four patients. The other four patients with pulmonary metastases had positive results on CT studies, whereas the results of bone SPECT studies remained negative. The results of bone SPECT studies were negative in the 19 patients without pulmonary metastases. CT, however, showed abnormalities in seven (37%) of the 19 patients, which were eventually attributed to benign conditions. CONCLUSION: Negative results on a bone SPECT study of the chest should not be used to exclude the possibility of lung metastases. However, if the results are positive, a bone SPECT study can be used to confirm abnormalities seen on CT scans and may also reveal subtle lesions missed on CT scans. 相似文献
45.
BJ van Vlijmen NJ Pearce M Berg? B Staels JW Yates AD Gribble BC Bond MH Hofker LM Havekes PH Groot 《Canadian Metallurgical Quarterly》1998,48(4):396-402
PURPOSE: We report an investigation into the distribution of proteoglycans (PGs) in normal, organ-cultured and dextran-treated human corneas. METHODS: Immunogold labeling was carried out at the electron microscope level to localize keratan sulphate (KS), chondroitin sulphate (CS), and heparan sulphate (HS) PGs. RESULTS: High levels of labeling for CS was found in the epithelium, endothelium, and keratocytes, with light labelling present in the basement membranes and the corneal stroma. Labeling for HS was present in the epithelium, endothelium, and keratocytes, with intense labeling present at the endothelium/Descemet's membrane interface and the epithelium/Bowman's layer interface. Large filaments were also observed in these regions in cuprolinic blue-stained specimens. Keratan sulphate was present at high levels in the stroma and the basement membranes with low levels present within the keratocytes, epithelium, and endothelium. The pattern of KS labeling along the collagen fibrils in the stroma sometimes showed evidence of periodicity. Organ-cultured corneas had extensive collagen-free "lakes," the interior of which immunolabeled positively for KS and showed staining with cuprolinic blue. The lakes were greatly reduced in the dextran-treated samples. CONCLUSION: This investigation determined the ultrastructural distribution of KS, CS, and HS PGs in human cornea and showed that organ culture is associated with a change in distribution of stromal PGs. 相似文献
46.
OBJECTIVES: To assess the comparability of the Hybritech Tandem-R and Abbott AxSYM PSA assays in the setting of a hospital laboratory changing methods of PSA assay. METHODS: A total of 115 serum samples were tested simultaneously with both reagent kits. These include samples from patients evaluated for screening, benign prostatic hyperplasia, and follow-up of prostate cancer. RESULTS: The outcomes of the Hybritech Tandem-R PSA test ranged from 0.0 to 48.3 ng/mL with a median value of 2.4 ng/mL (mean 3.48, SD 5.46). The outcomes of the Abbott AxSYM PSA test ranged from 0.0 to 49.33 ng/mL with a median of 2.22 ng/mL (mean 3.82, SD 5.59). The outcomes of the two assays were found to be highly correlated by the Pearson correlation coefficient (r = 0.9942). When samples were divided according to PSA levels of 0.0 to less than 2.5, 2.5 to less than 4.0, 4.0 to less than 10.0, and 10.0 to less than 25.0 ng/mL, the outcomes were also highly correlated in all PSA level ranges (r = 0.9619, 0.8094, 0.9167, and 0.9081, respectively). CONCLUSIONS: The PSA values of the Tandem-R and Abbott AxSYM assays are highly correlated in the PSA level ranges of 0.0 to less than 2.5, 2.5 to less than 4.0, 4.0 to less than 10.0, and 10.0 to less than 25.0 ng/mL. 相似文献
47.
The Ca2+-sensitive K+ channel (K(Ca) channel) plays a key role in buffering pressure-induced constriction of small cerebral arteries. An amplified current through this channel has been reported in vascular smooth muscle cells obtained from hypertensive animals, implying that the expression or properties of K(Ca) channels may be regulated by in vivo blood pressure levels. In this study, we investigated this hypothesis and its functional relevance by comparing the properties, expression levels, and physiological role of K(Ca) channels in cerebral resistance arteries from normotensive and genetically hypertensive rats. Whole-cell patch-clamp experiments revealed a 4.7-fold higher density of iberiotoxin-sensitive K(Ca) channel current at physiological membrane potentials in spontaneously hypertensive rat (SHR) compared with Wistar-Kyoto (WKY) rat cerebrovascular smooth muscle cells (n = 18 and 21, respectively). However, additional single-channel analysis in detached patches showed similar levels of unitary conductance, voltage, and Ca2+ sensitivity in K(Ca) channels from WKY and from SHR membranes. In contrast, Western analysis using an antibody directed against the K(Ca) channel alpha-subunit revealed a 4.1-fold increase in the corresponding 125-kD immunoreactive signal in cerebrovascular membranes from SHR compared with WKY rats. The functional impact of this enhanced K(Ca) channel expression was assessed in SHR and WKY rat pial arterioles, which were monitored by intravital microscopy through in situ cranial windows. Progressive pharmacological block of K(Ca) channels by iberiotoxin (0.1 to 100 nmol/L) dose-dependently constricted pial arterioles from SHR and WKY rats (n = 6 to 8). The arterioles in SHR constricted 2- to 4-fold more intensely, and vasospasm occurred in some vessels. These data provide the first direct evidence that elevated levels of in situ blood pressure induce K(Ca) channel expression in cerebrovascular smooth muscle membranes. This homeostatic mechanism may critically regulate the resting tone of cerebral arterioles during chronic hypertension. Furthermore, the overexpression of distinct K+ channel types during specific cardiovascular pathologies may provide for the upregulation of novel disease-specific membrane targets for vasodilator therapies. 相似文献
48.
NJ Beauchamp RN Pike M Daly L Butler M Makris TR Dafforn A Zhou HL Fitton FE Preston IR Peake RW Carrell 《Canadian Metallurgical Quarterly》1998,92(8):2696-2706
The inherent variability of conformational diseases is demonstrated by two families with different mutations of the same conserved aminoacid in antithrombin. Threonine 85 underlies the opening of the main beta-sheet of the molecule and its replacement, by the polar lysine, in antithrombin Wobble, resulted in a plasma deficiency of antithrombin with an uncharacteristically severe onset of thrombosis at 10 years of age, whereas the replacement of the same residue by a nonpolar methionine, antithrombin Wibble, gave near-normal levels of plasma antithrombin and more typical adult thromboembolic disease. Isolated antithrombin Wibble had a decreased thermal stability (Tm 56.2, normal 57.6 degreesC) but was fully stabilized by the heparin pentasaccharide (Tm 71.8, normal 71.0 degreesC), indicating that the prime abnormality is a laxity in the transition of the main sheet of the molecule from the 5- to 6-stranded form, as was confirmed by the ready conversion of antithrombin Wibble to the 6-stranded latent form on incubation. That this transition can occur in vivo was shown by the finding of nearly 10% of the proband's plasma antithrombin in the latent form and also, surprisingly, of small but definitive amounts of latent antithrombin in normal plasma. The latent transition will be predictably accelerated not only by gross mutations, as with antithrombin Wobble, to give severe episodic thrombosis, but also by milder mutations, as with antithrombin Wibble, to trigger thrombosis in the presence of other predisposing factors, including the conformational stress imposed by the raised body temperatures of fevers. Both antithrombin variants had an exceptional (25-fold) increase in heparin affinity and this, together with an increased inhibitory activity against factor Xa, provides evidence of the direct linkage of A-sheet opening to the conformational basis of heparin binding and activation. 相似文献
49.
The long cane can be used as a mobility aid for visually handicapped people. According to a questionnaire completed by Japanese cane users, it seems they are not always satisfied with using long canes for a variety of reasons. In this study, hand-transmitted vibration from the long cane due to tapping the ground was measured because an exposure to repeated shock-type tapping vibration may affect the hand-arm system. A sighted female wearing a blindfold participated. The measurement was carried out in different conditions with three different ground materials both indoor and outdoors. The vibration at three axes of the cane grip and one axis at the wrist were measured. The pinch forces between an index finger and the grip were also measured using a strain gauge in order to observe how the vibration characteristics depend on the changing forces. Measurement, evaluation and assessment were based on the International Standard (ISO 5349). The estimated daily exposure time and the transmissibility were obtained in order to investigate the severity of the hand-transmitted vibration caused by the long cane. It was found that the characteristics of tapping vibration depend on different measurement conditions and the vibration might be associated with a health risk over a long life span. 相似文献
50.
We investigated the behavior of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APx), in potato tubers during storage at low temperature. SOD activity increased temporarily within 3 weeks and was higher at 1 degree C than at 20 degrees C. APx activity also increased more at low (1 degree C) than at higher temperatures (5 and 20 degrees C). The contents of ascorbic acid (AsA), which is the substrate of APx, decreased immediately within 3 weeks and then gradually decreased until 15 weeks. The activity of CAT, the other enzyme which can scavenge hydrogen peroxide, decreased once in the first six weeks and thereafter increased to 15 weeks. Thus, the enhancement of the active oxygen-scavenging system that was induced by low temperature in potato tubers could result not only in a decrease of AsA but also in combined increases in APx and CAT activity whose manners were different. 相似文献