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941.
KN Garratt DR Holmes V Molina-Viamonte GS Reeder DO Hodge KR Bailey JK Lobl DA Laudon RJ Gibbons 《Canadian Metallurgical Quarterly》1998,136(2):196-204
TCRhigh cells are generated by the mainstream of T cell differentiation in the thymus, whereas TCRint cells (or NK1.1+ T cells) are generated extrathymically in the liver and by an alternative intrathymic pathway. It is still unknown how these T cell populations interact in vivo with each other. To investigate the interaction of TCRint cells with TCRhigh cells, we used congenitally athymic nude (B6-nu/nu) mice which carry only TCRint cells in all immune organs. When TCRhigh cells from B6-C-H-2bm12 (bm12) mice (i.e. I-Abm12) were injected into B6-nu/nu mice (i.e. 1-Ab), the expanding T cell population was a mixture of TCRhigh cells of donor origin and TCRint cells of recipient origin. However, 9 Gy-irradiated nude mice permitted a full expansion of TCRhigh cells which expressed the IL-2Ralpha+beta+ phenotype, namely, they were at the most activated state. These mice died of acute graft-versus-host disease (GVHD) within 5 days. On the other hand, non-irradiated nude mice suppressed the expansion of TCRhigh cells of donor origin and such TCRhigh cells continued to have the IL-2Ralpha(+/-)beta+ phenotype. These mice could survive but showed signs of chronic GVHD thereafter. In both situations, CD4+alphabeta T cells expanded irrespective of donor or recipient origin. These results suggest that TCRint cells in the recipient mice possess a regulatory function in relation to donor TCRhigh cells; as a result, fully activated TCRhigh cells acquired the IL-2Ralpha+beta+ phenotype and injured the host, but TCRhigh cells suppressed in vivo remained as the IL-2Ralpha(+/-)beta+ phenotype and only partially injured the host. 相似文献
942.
JF Winther FW Bach S Friis WJ Blot L Mellemkjaer K Kj?ller C H?gsted JK McLaughlin JH Olsen 《Canadian Metallurgical Quarterly》1998,50(4):951-955
US angiography, enhanced with intraarterial CO2 microbubbles imaging, documented 40 nodules of hepatocellular carcinoma (HCC) lesser than 20 mm in diameter in 34 patients, which were convinced histopathologically. As to the imaging acuity of arterial vascularity in nodules, US angiography was compared with DSA and US color angio. The detection of arterial vascularity was possible in 34 (85.0%) of 40 nodules by US angiography, 26 (65.0%) by DSA, and 28 (70.0 %) by US color angio. US angiography was available for detection of HCC, particularly with small HCC lesser than 20 mm in size. 相似文献
943.
MA Froetschel JK Courchaine SW Nichols HE Amos AC Murry 《Canadian Metallurgical Quarterly》1997,80(3):511-518
This study explores the effects of infusion of nerve growth factor (NGF) on behavioral outcome and cell death in the septal region using the clinically relevant model of fluid-percussion brain injury in the rat. Animals were subjected to fluid-percussion brain injury and 24 hours later a miniosmotic pump was implanted to infuse NGF (12 animals) or vehicle (12 animals) directly into the region of maximum injury for 2 weeks. Four weeks postinjury the animals were tested for cognitive function using a Morris Water Maze paradigm. Neurological motor function was evaluated over a 4-week postinjury period. The rats receiving NGF infusions had significantly higher memory scores than vehicle-treated animals. Examination of the cholinergic neurons in the medial septal region using choline acetyltransferase immunohistochemistry demonstrated significant cell loss after injury. Infusion of NGF significantly attenuated loss of these cholinergic neurons. A second group of animals was subjected to fluid-percussion brain injury alone (23 rats) or injury followed by NGF infusion (18 rats). These animals were killed between 24 hours and 2 weeks postinjury and the septal region was examined for the presence of apoptotic cells using the terminal deoxynucleotidyl transferase-mediated biotinylated-deoxyuridinetriphosphate nick-end labeling technique. Apoptotic cells were identified as early as 24 hours postinjury; their numbers peaked at 4 and 7 days, and then declined by 14 days. The NGF-treated animals had some apoptotic cells; however, even at 7 days there were significantly fewer of these cells. No significant motor differences were observed between the NGF- and vehicle-treated groups. These data indicate that NGF administration beginning 24 hours after fluid-percussion brain injury has a beneficial effect on cognition and results in sparing of cholinergic septal neurons. These improvements persist after cessation of NGF administration. The beneficial effects of NGF may be related to its ability to attenuate traumatically induced apoptotic cell death. 相似文献
944.
JK Patnaik BS Das SK Mishra S Mohanty SK Satpathy D Mohanty 《Canadian Metallurgical Quarterly》1994,51(5):642-647
To document histopathologic evidence on the pathogenic mechanism of human cerebral malaria, we used light microscopy to study brain specimens from 23 patients who died of central nervous system involvement with Plasmodium falciparum. Sequestration of parasitized red blood cells (PRBCs) leading to cerebral capillary clogging was seen. In a few specimens, vascular clogging by PRBCs was associated with margination of mononuclear cells. In others, capillaries were virtually empty and lymphocytes and monocytes were seen in apposition (marginated) to the capillary endothelial surface. The endothelial cells appeared plump, hypertrophied, and prominent. The capillary wall appeared thickened by fibrinous material. Massive intercellular brain edema along with extravasated red blood cells, mononuclear cells, and plasmatic fluid was also noticed. In addition to hypoxia induced by PRBC-mediated vascular clogging, marginating mononuclear cells may contribute to the pathogenesis of cerebral malaria. The precise role played by this phenomenon needs further evaluation. 相似文献
945.
946.
947.
FJ van Spronsen Y Thomasse GP Smit JV Leonard PT Clayton V Fidler R Berger HS Heymans 《Canadian Metallurgical Quarterly》1994,20(5):1187-1191
Hereditary tyrosinemia type I (McKusick 27670) is a heterogeneous disease with poor prognosis, yet there are few reports of the long-term prognosis. It is therefore difficult to decide on the treatment for individual patients. We have conducted an international survey of patients with tyrosinemia type I and examined the probability of survival on dietary treatment and the causes of death in 108 patients with tyrosinemia type I. The survival after the onset of symptoms varied with the age at onset; the earlier the symptoms developed the poorer the outlook. Liver failure and recurrent bleeding (67%), hepatocellular carcinoma (17%) and the porphyria-like syndrome with respiratory failure (10%) were the most common causes of death. The 1- and 2-yr survival probability after the onset of symptoms in patients in whom symptoms developed before 2 mo, between 2 and 6 mo and after 6 mo were 38%/29%, 74%/74% and 96%/96%, respectively. On the basis of these survival rates, a new classification--which is important with respect to choices in treatment--is proposed: very early (onset of symptoms < 2 mo), early (2 to 6 mo) and late presenting form (> 6 mo). 相似文献
948.
GW Miller JK Staley CJ Heilman JT Perez DC Mash DB Rye AI Levey 《Canadian Metallurgical Quarterly》1997,41(4):530-539
The plasma membrane dopamine transporter (DAT) is considered to be a reliable marker of presynaptic dopaminergic terminal loss. Previous in vivo imaging and postmortem binding studies have detected a loss in striatal DAT binding in Parkinson's diseased (PD) brain; however, these techniques have poor spatial resolution and may suffer from nonspecific binding of some ligands. In this study, we use novel highly specific monoclonal antibodies to distinct epitopes of human DAT to quantify and localize the protein. Western blot analysis revealed marked reductions in DAT immunoreactivity in putamen, caudate, and nucleus accumbens of PD brain compared with control cases, and the reductions were significantly correlated to disease duration. Immunohistochemistry revealed DAT-immunoreactive fibers and puncta that were dense throughout the striatum of control brains but that were drastically reduced in putamen of PD brains. Caudate from PD brains showed a significant degree of sparing along the border of the ventricle, and the nucleus accumbens was relatively preserved. An unexpected finding was that discrete islands of DAT immunoreactivity were preserved within the matrix of PD putamen. Thus, immunological analysis of DAT protein provides novel and sensitive means for localizing and quantifying DAT protein in PD and other neurological disorders involving dopaminergic systems. 相似文献
949.
The classical clinical picture of coeliac disease includes prolonged diarrhoea with failure to thrive. During the past two decades this type of active presentation of coeliac disease has decreased in many European countries, giving the impression that coeliac disease is a disappearing disease. However, this is not true. The disease can be found in older children with a more or less silent presentation. Silent coeliac disease can be detected by active screening with serological tests. Coeliac disease can be suspected in children suffering from mild gastrointestinal symptoms, such as abdominal pain, and in those with signs of nutritional deficiencies, as well as in children of first-degree relatives of already diagnosed coeliacs, patients with IgA-deficiency, patients suffering from dental enamel hypoplasia or dermatitis herpetiformis, and patients with some other disease known to be associated with coeliac disease, such as diabetes mellitus. According to the fundamental criteria of coeliac disease, the intestinal mucosa is flat when the individual is eating gluten-containing foods. However, this is not strictly true. Intolerance to gluten is obviously variable and the intestinal mucosa may be normal. This type of latent coeliac disease can be detected by analysing genetic markers, measuring antibodies in intestinal fluid or counting the density of intra-epithelial gamma/delta T cells which are increased greatly even in the latent phase of coeliac disease. Thus the general concept of the natural history of coeliac disease is changing. 相似文献
950.