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21.

Background  

Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards C. parapsilosis in vitro.  相似文献   
22.
The glucose-dependent insulinotropic peptide receptor (GIPR) has been implicated with neuroplasticity and may be related to epilepsy. GIPR expression was analyzed by immunohistochemistry in the hippocampus (HIP) and neocortex (Cx) of rats undergoing pilocarpine induced status epilepticus (Pilo-SE), and in three young male patients with left mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) treated surgically. A combined GIPR immunohistochemistry and Fluoro-Jade staining was carried out to investigate the association between the GIPR expression and neuronal degeneration induced by Pilo-SE. GIPR was expressed in the cytoplasm of neurons from the HIP CA subfields, dentate gyrus (DG) and Cx of animals and human samples. The GIPR expression after the Pilo-SE induction increases significantly in the HIP after 1 h and 5 days, but not after 12 h or 50 days. In the Cx, the GIPR expression increases after 1 h, 12 h and 5 days, but not 50 days after the Pilo-SE. The expression of GIPR 12 h after Pilo-SE was inversely proportional to the Fluoro-Jade staining intensity. In the human tissue, GIPR expression patterns were similar to those observed in chronic Pilo-SE animals. No Fluoro-Jade stained cells were observed in the human sample. GIPR is expressed in human HIP and Cx. There was a time and region dependent increase of GIPR expression in the HIP and Cx after Pilo-SE that was inversely associated to neuronal degeneration.  相似文献   
23.
The fate of vicilins ingested by Callosobruchus maculatus and the physiological importance of these proteins in larvae and adults have been recently investigated. Vicilins have been demonstrated to be absorbed through the midgut epithelium, circulate in their trimeric form in the haemolymph and are deposited in the fat body. In fat body cells of both sexes, vicilins are partially hydrolyzed and the fragments are eventually deposited in the eggs. Tracking the fate of FITC-labelled vicilins in adult males revealed that the labelled vicilin fragments were also detected in oöcytes and eggs, when the males copulated with non-labelled females. Based on the results presented here, we propose that following absorption, vicilins accumulate in the fat body, where they are partially degraded. These peptides are retained throughout the development of the males and are eventually sequestered by the gonads and passed to the female gonads during copulation. It is possible that accumulation in the eggs is a defensive strategy against pathogen attack, as these peptides are known to have antimicrobial activity. The contribution of vicilin-derived peptides from seminal fluids may be an investment that helps to increase the offspring survival. This study provides additional insights into the possible contributions of males to female fecundity following copulation in C. maculatus.  相似文献   
24.
Enrichment culture experiments employing soil and water samples obtained from petroleum-contaminated environments succeeded in the isolation of a pure culture possessing the ability to utilize quinoline as a sole nitrogen source but did not utilize quinoline as a carbon source. This culture was identified as Pseudomonas ayucida based on a partial 16S rRNA gene sequence, and the strain was given the designation IGTN9m. Examination of metabolites using thin-layer chromatography and gas chromatography-mass spectrometry suggests that P. ayucida IGTN9m converts quinoline to 2-quinolinone and subsequently to 8-hydroxycoumarin. Resting cells of P. ayucida IGTN9m were shown to be capable of selectively removing about 68% of quinoline from shale oil in a 16-h treatment time. These results suggest that P. ayucida IGTN9m may be useful in petroleum biorefining for the selective removal of organically bound nitrogen from petroleum.  相似文献   
25.
    
The idea of immunological surveillance against cancer has existed for nearly 100 years but as no conclusive evidence has yet been published the importance of the cellular immune defense in the detection and removal of incipient or existing tumors is still a hotly debated subject. However, in order to select a relevant immunotherapeutic strategy in the treatment of cancer, a fundamental understanding of the basic immunologic conditions under which a tumor develops and exists is a prerequisite. Therefore, a murine model was set up that we hoped would enable us to confirm or reject the theory of immunological surveillance. A large panel of methylcholanthrene induced tumors was established in T-cell immunodeficient nude mice and congenic normal mice to study the influence of the immune system on developing tumors. As nude mice developed tumors fastest and with the highest incidence, we concluded that in this model the immune system constituted a ‘tumor-suppressive factor’ delaying and sometimes abrogating tumor growth, i.e. performing immune surveillance. Immunogenicity of the tumors was assessed by transplantation back to normal histocompatible mice. Tumors originating from the immunodeficient nude mice turned out to be far more immunogenic than tumors from normal mice, resulting in a high rejection rate. CD8+cytotoxic T cells were found to be indispensable for this rejection, leading to the conclusion that the cytotoxic T cells perform immune selection in normal mice, eliminating immunogenic tumor cell variants in the incipient tumor. In this review, we discuss the difficulties facing immunotherapy when conclusions are drawn from the presented observations and hypotheses.  相似文献   
26.
Photolysis of HbNO has been studied from 6.2 K to 15.5 K by electron spin resonance during and after continuous illumination. Non-exponential kinetics of both dissociation and reassociation of NO was observed. The prolonged illumination separates the fast and slow ligands. This picture is consistent with NO tunnelling from two sites at different distances from the bound position. This result is obtained using a model of a sum of two exponentials or of conformational substates.  相似文献   
27.
Humic acids from four Brazilian topsoils of different origin and four fungal melanins, synthesized under two cultural conditions were subjected to a two step hydrolysis procedure and the released monosaccharides qualitatively and quantitatively determined by gas-liquid chromatography. The neutral sugars, glucose, galactose, mannose, arabinose, xylose, fucose, rhamnose and the alcohol sugar inositol, were detected in most of the soil humic acid samples. The fungal melanins showed the presence of glucose, galactose, mannose and arabinose. Ribose was present in two out of the eight samples tested. Some quantitative differences in the two types of humic polymers were noted and expected considering their origins. However, similarities were more apparent than differences and give further indication that melanic fungi may play a significant role in the formation of soil humic acids.  相似文献   
28.
The phylum Porifera (sponges) was the first to diverge from the common ancestor of the Metazoa. In this study, six cDNAs coding for protein- serine/threonine kinases (PS/TKs) are presented; they have been isolated from libraries obtained from the demosponges Geodia cydonium and Suberites domuncula and from the calcareous sponge Sycon raphanus. Sequence alignments of the catalytic domains revealed that two major families of PS/TK, the "conventional" (Ca(2+)-dependent) protein kinase C (PKC), the cPKC subfamily, as well as the "novel" (Ca(2+)- independent) PKC (nPKC), form two separate clusters. In each cluster, the sequence from S. raphanus diverges first. To approach the question about the origin of protein-tyrosine kinases (PTK), which are found only in Metazoa, we analyzed two additional PS/TKs which have been cloned from S. domuncula: the stress-responsive protein kinase (KRSvSD) and the protein-kinase-C-related kinase (PRKvSD). The construction of the phylogenetic tree, comprising the eight PS/TKs and the PTK cloned previously from G. cydonium, revealed that the PTK derived from the branch including the KRSvSD kinase. These data facilitate the first molecular approach to elucidate the origin of metazoan PTK within the PS/TK superfamily.   相似文献   
29.
Photolysis of nitrosyl haemoglobin (HbNO) has been studied from 6.5 K to 20 K for different NO saturation conditions. The kinetic curves are fitted equally well by a biphasic exponential and a distribution of activation energies. The parameters are straightforwardly related to the quaternary structure of the protein. The biphasic model indicates that two germinate processes in the NO reassociation to Hb dominate at low temperatures independent of the protein conformation.  相似文献   
30.
After re-emergence of malaria in 1993, a continued increase in Plasmodium vivax cases was observed from 1993 to 2006 in northern Gyeonggi and Gangwon Provinces adjacent to the demilitarized zone separating North from South Korea. Annual parasite incidence per 1000 people ranged from 0.33 in 2004 to 0.89 in 2006. While malaria case rates declined (22.6%) in 2004, they increased 75.1% in 2005 and 51.7% in 2006 from the previous years. An initial incorrect diagnosis of 46.8% of malaria cases as common cold resulted in a mean delay of 1.3 days for the detection malarial parasites. Of the total cases, 10.2% from December to May were due to latent intrinsic incubation infections acquired the previous malaria season and the rest of the cases from June to November were either latent or short incubation infections. Overall, the peak anopheline population occurred from July to September, resulting in a similar peak in malaria cases. While malaria cases increased during 2005–2006, anopheline populations, based on trap indices, were not significantly different during 4 years of surveillance. To decrease the malaria patient infective period to mosquitoes, public health centers in Paju and Cheorwon in 2006 prescribed chloroquine + primaquine at days 0–3 after initial malaria diagnosis followed by an additional 11 days of primaquine (early primaquine treatment), rather than chloroquine on days 0–3 and primaquine on days 4–17 (delayed primaquine treatment). A reduction in the malaria parasite incidence during 2007 was recorded for the two locations offering the early primaquine treatment relative to other locations using the delayed primaquine treatment.  相似文献   
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