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91.
R P Virsik-Peuckert D Harder 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1986,49(4):673-681
Dicentric chromosome aberration yields have been measured after single-exposure and split-dose irradiations of human lymphocytes with 150 kV X-rays. Various temperature programmes between 4 and 37 degrees C were applied before, during and after irradiations and in the radiation-free interval. It was found that chromatin lesion repair was completely suppressed at 21 degrees C and below, whereas lesion formation is reduced only below 17 degrees C. The interaction between repairable lesions which leads to exchange-type aberrations is also suppressed by low temperatures. Hypothermic suppression of chromatin lesion repair and interaction is fully reversible at least up to 12 h of maintenance of the 'stored' state of these lesions. 相似文献
92.
This paper describes the development of experimental Chagas' disease in 64 out-bred young dogs. Twenty-nine animals were inoculated with the Be-62 and 35 with Be-78 Trypanosoma cruzi strains. Twenty-six were infected with blood trypomastigotes by different inoculation routes and 38 with metacyclic trypomastigotes from the vector via the conjunctival route. Twenty of the 26 dogs infected with blood trypomastigotes were autopsied during the acute phase. Eleven died spontaneously and nine were sacrificed. Six remained alive until they died suddenly (two) or were autopsied. (four). Twelve of the 38 dogs infected with metacyclic trypomastigotes evolved naturally to the chronic phase and remained alive for 24-48 months. The parasitemia, clinical aspects and serology (IgM and IgG) as well as electrocardiogram, hemogram and heart anatomo-histopathologic patterns of acute and chronic cardiac forms of Chagas' disease as seen in human infections, were reproduced. The most important finding is the reproducibility of diffuse fibrosing chronic chagasic cardiopathy in all dogs infected with Be-78 T. cruzi strain autopsied between the 90th and 864th days of infection. Thus, the dog can be considered as a suitable experimental model to study Chagas' disease according to the requisites of the Word Health Organization (1984). Furthermore the animal is easily obtained and easy to handle and maintain in experimental laboratory conditions. 相似文献
93.
Identification of the IL-17 receptor related molecule IL-17RC as the receptor for IL-17F 总被引:2,自引:0,他引:2
Kuestner RE Taft DW Haran A Brandt CS Brender T Lum K Harder B Okada S Ostrander CD Kreindler JL Aujla SJ Reardon B Moore M Shea P Schreckhise R Bukowski TR Presnell S Guerra-Lewis P Parrish-Novak J Ellsworth JL Jaspers S Lewis KE Appleby M Kolls JK Rixon M West JW Gao Z Levin SD 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(8):5462-5473
The proinflammatory cytokines IL-17A and IL-17F have a high degree of sequence similarity and share many biological properties. Both have been implicated as factors contributing to the progression of inflammatory and autoimmune diseases. Moreover, reagents that neutralize IL-17A significantly ameliorate disease severity in several mouse models of human disease. IL-17A mediates its effects through interaction with its cognate receptor, the IL-17 receptor (IL-17RA). We report here that the IL-17RA-related molecule, IL-17RC is the receptor for IL-17F. Notably, both IL-17A and IL-17F bind to IL-17RC with high affinity, leading us to suggest that a soluble form of this molecule may serve as an effective therapeutic antagonist of IL-17A and IL-17F. We generated a soluble form of IL-17RC and demonstrate that it effectively blocks binding of both IL-17A and IL-17F, and that it inhibits signaling in response to these cytokines. Collectively, our work indicates that IL-17RC functions as a receptor for both IL-17A and IL-17F and that a soluble version of this protein should be an effective antagonist of IL-17A and IL-17F mediated inflammatory diseases. 相似文献
94.
Motohiro Kobayashi Heeseob Lee Lana Schaffer Tim J Gilmartin Steven R Head Shigeo Takaishi Timothy C Wang Jun Nakayama Minoru Fukuda 《The journal of histochemistry and cytochemistry》2007,55(3):263-274
Helicobacter pylori infects over half the population worldwide and is a leading cause of chronic gastritis and gastric cancer. However, the mechanism by which this organism induces inflammation and carcinogenesis is not fully understood. In the present study we used insulin-gastrin (INS-GAS) transgenic mice that fully develop gastric adenocarcinoma after infection of H. pylori-related Helicobacter felis. Histological examination revealed that more than half of those mice developed invasive adenocarcinoma after 8 months of infection. These carcinomas were stained by NCC-ST-439 and HECA-452 that recognize 6-sulfated and non-sulfated sialyl Lewis X. Lymphocytic infiltration predominantly to submucosa was observed in most H. felis-infected mice, and this was associated with the formation of peripheral lymph node addressin (PNAd) on high endothelial venule (HEV)-like vessels detected by MECA-79. Time-course analysis of gene expression by using gene microarray revealed upregulation of several inflammation-associated genes including chemokines, adhesion molecules, surfactant protein D (SP-D), and CD74 in the infected stomach. Immunohistochemical analysis demonstrated that SP-D is expressed in hyperplasia and adenocarcinoma whereas CD74 is expressed in adenocarcinoma in situ and invasive carcinoma. These results as a whole indicate that H. felis induces HEV-like vessels and inflammation-associated chemokines and chemokine receptors, followed by adenocarcinoma formation. 相似文献
95.
Unlike pollen and seed size, the extent and causes of variation in ovule size remain unexplored. Based on 45 angiosperm species, we assessed whether intra- and interspecific variation in ovule size is consistent with cost minimization during ovule production or allows maternal plants to dominate conflict with their seeds concerning resource investment. Despite considerable intraspecific variation in ovule volume (mean CV = 0.356), ovule production by few species was subject to a size-number trade-off. Among the sampled species, ovule volume varied two orders of magnitude, whereas seed volume varied four orders of magnitude. Ovule volume varied positively among species with flower mass and negatively with ovule number. Tenuinucellate ovules were generally larger that crassinucellate ovules, and species with apical placentation (which mostly have uniovulate ovaries) had smaller ovules than those with other placentation types. Seed volume varied positively among species with fruit mass and seed development time, but negatively with seed number. Seeds grew a median 93-fold larger than the ovules from which they originated. Our results provide equivocal evidence that selection minimizes ovule size to allow efficient resource allocation after fertilization, but stronger evidence that ovule size affords maternal plants an advantage in parent-offspring conflict. 相似文献
96.
Coruasić A Barisić D Plavec A Planinić P Skrgatić L Vujić G Herman M 《Collegium antropologicum》2007,31(Z2):147-154
With correct staging a large number of patients with cervical cancer FIGO stages IA2 and IB can be spared of unnecessary radiation therapy by laparoscopic assisted vaginal radical hysterectomy (LAVRH) as an option of radical surgical treatment in such patients. The development of laparovaginal surgery, indication and contraindication were presented. Also, the surgical technique was described in detail. Fifty-two patients were followed up in 2003 after LAVRH or open surgery, performed in our single center. Only 5 (14%) patients died from cervical cancer within 3 years following the treatment. They were all clinical stage IB treated with open surgery. There were 4 (11%) complications following treatment and they were all in patients with clinical stage IB, also treated with open surgery. There was no complication in LAVRH treated patients. The results and complications of the sole Croatian center performing LAVRH or open surgery in patients with cervical cancer FIGO stages IA and IB were similar to those in centers across the world. 相似文献
97.
Kaiser L Davis J Patterson J Boyd RF Olivier NB Bohart G Schwartz KA 《Comparative medicine》2007,57(4):383-389
Cardiac events, including heart failure and arrhythmias, are the leading cause of death in patients with beta thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The goal of the current study was to determine whether cardiac arrhythmias occurred in the guinea pig model of secondary iron overload. Electrocardiograms were recorded by using surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran (test animals) or dextran alone (controls). Loading occurred over approximately 6 wk. Electrocardiograms were recorded for 1 wk prior to loading, throughout loading, and for approximately 4 wk after loading was complete. Cardiac and liver iron concentrations were significantly increased in the iron-loaded animals compared with controls and were in the range of those reported for humans with thalassemia. Arrhythmias were rare in both iron-loaded and control guinea pigs. No life-threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias in the iron-loaded guinea pig model and that arrhythmias detected in human patients with iron overload may be the result of a complex interplay of factors. 相似文献
98.
99.
Jaquelline Carla Valamiel de Oliveira-Silva Girley Francisco Machado-de-Assis Maykon Tavares Oliveira Nívia Carolina Noguieira Paiva Márcio Sobreira Silva Araújo Cláudia Martins Carneiro Olindo Assis Martins-Filho Helen Rodrigues Martins Marta de Lana 《Memórias do Instituto Oswaldo Cruz》2015,110(1):86-94
Trypanosoma cruzi strains from distinct geographic areas show differences in drug
resistance and association between parasites genetic and treatment response has been
observed. Considering that benznidazole (BZ) can reduce the parasite burden and
tissues damage, even in not cured animals and individuals, the goal is to assess the
drug response to BZ of T. cruzi II strains isolated from children of the
Jequitinhonha Valley, state of Minas Gerais, Brazil, before treatment. Mice infected
and treated with BZ in both phases of infection were compared with the untreated and
evaluated by fresh blood examination, haemoculture, polymerase chain reaction,
conventional (ELISA) and non-conventional (FC-ALTA) serologies. In mice treated in
the acute phase, a significant decrease in parasitaemia was observed for all strains.
Positive parasitological and/or serological tests in animals treated during the acute
and chronic (95.1-100%) phases showed that most of the strains were BZ resistant.
However, beneficial effect was demonstrated because significant reduction (p <
0.05%) and/or suppression of parasitaemia was observed in mice infected with all
strains (acute phase), associated to reduction/elimination of inflammation and
fibrosis for two/eight strains. BZ offered some benefit, even in not cured animals,
what suggest that BZ use may be recommended at least for recent chronic infection of
the studied region. 相似文献
100.