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排序方式: 共有346条查询结果,搜索用时 281 毫秒
1.
2.
Analysis of the human regulators of complement activation (RCA) gene cluster with yeast artificial chromosomes (YACs). 总被引:6,自引:0,他引:6
D Hourcade A D Garcia T W Post P Taillon-Miller V M Holers L M Wagner N S Bora J P Atkinson 《Genomics》1992,12(2):289-300
The human regulators of complement activation gene cluster (RCA cluster) have been partially characterized with yeast artificial chromosomes (YACs). While the data confirm many points previously elucidated, the finer resolution of YAC mapping has allowed the discovery and/or localization of partial gene duplications, the determination of gene orientations, and the measurement of gaps between known genes. Here nine overlapping YACs that encompass a genomic region of 800 kb, encoding four RCA genes and three gene-like elements, are described. The encoded genes and two of the gene-like elements share the same orientation and are ordered (5' to 3') DAF, CR2, CR1, MCP-like, CR1-like, and MCP. A C4bp-like region lies upstream from DAF and is likely to correspond to one recently observed by F. Pardo-Manuel, J. Rey-Campos, A. Hillarp, B. Dahlback, and S. Rodriguez de Cordoba (1990, Proc. Natl. Acad. Sci. USA 87: 4529-4533). MCP-like, a new genetic element, was discovered and found to be homologous to the 5' portion of the MCP gene. Two large gaps of 85 kb (between CR2 and DAF) and 110 kb (between DAF and the C4bp-like element) could carry additional RCA genes. The arrangement of CR1, MCP-like, CR1-like, and MCP, in that order, strongly suggests that this region was generated by a single duplication of neighboring CR1/CR1-like and MCP/MCP-like forerunners. The RCA YACs will now serve as convenient DNA sources for the subcloning and further characterization of this region. 相似文献
3.
Short-term metabolic and concomitant morphologic effects of streptozotocin diabetes on isoproterenol-induced myocardial infarction
was studied in Wistar rats, Of particular significance was the observation that myocardial infarction in concert with diabetes
brought about a distinctive exacerbation of the severity and complexity of the histopathological lesions. Of all the biochemical
parameters, serum glucose and free fatty acids registered maximum elevation and serum lactate and cardiac glycogen levels
a maximum reduction. Among the lipoproteins, an inverse relationship was found between high density lipoproteins and low density
and very low density lipoproteins; while high density lipoproteins, ratio of high density lipoprotein to low density lipoprotein
and the percentage of high density lipoprotein were decreased, there was a significant increase in low density lipoprotein
concentration and percentage values of low density and very low density lipoproteins. In diabetes, the B cell of the endocrine
pancreas depicted selective necrosis. Loss of insulin granules and wide-spread necrobiosis of cellular elements of the pancreatic
islets were observed, respectively, in myocardial infarction and in diabetes plus myocardial infarction combinations. Pathological
evidence of chemical-induced mild toxicity was present in the exocrine parenchyma. Mitotic features and the presence of centroacinar
cells in the damaged Langerhans’ islets supposedly formed the basis of regeneration of the tissue in diabetes, with or without
vascular complications 相似文献
4.
The protective effect of arbutin against potassium bromate-induced oxidative damage in the rat brain
H. Turan Akkoyun Ahmet Uyar Mahire Bayramoglu Akkoyun Aydın Şükrü Bengü Şule Melek Fatma Karagözoğlu Sevinç Aydın Suat Ekin Sinem Aslan Erdem 《Journal of biochemical and molecular toxicology》2023,37(2):e23248
This study aimed to investigate the protective effects of arbutin (ARB) against brain injury induced in rats with potassium bromate (KBrO3). The rats were divided into four groups as Group 1: Control (0.9% NaCl ml/kg/day p.), Group 2: KBrO3 (100 mg/kg (gavage), Group 3: ARB (50 mg/kg/day p.), and Group 4: KBrO3 + ARB (100 mg/kg (gavage) + 50 mg/kg/day p.). At the end of the fifth day of the study, the rats in all groups were killed, and their brain tissues were collected. In the collected brain tissues, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were measured, and routine histopathological examinations were made. The MDA levels in the group that was exposed to KBrO3 were significantly higher than those in the control group (p ˂ 0.001). In comparison to the KBrO3 group, the MDA levels in the KBrO3 + ARB group were significantly lower (p ˂ 0.001). It was observed that SOD and CAT enzyme activity levels were significantly lower in the KBrO3 group compared to the control group (p ˂ 0.001), while these levels were significantly higher in the KBrO3 + ARB group than in the KBrO3 group (p ˂ 0.001). Additionally, the group that was subjected to KBrO3 toxicity, as well as ARB administration, had much lower levels of histopathologic signs than the group that was subjected to KBrO3 toxicity only. Consequently, it was found that KBrO3 exposure led to injury in the brain tissues of the rats, and using ARB was effective in preventing this injury. 相似文献
5.
6.
Karadag Abdullah Ozen Ata Ozkurt Mete Can Cavit Bozgeyik Ibrahim Kabadere Selda Uyar Ruhi 《Molecular biology reports》2021,48(7):5531-5539
Molecular Biology Reports - Herein, we identified miRNA signatures that were able to differentiate malignant prostate cancer from benign prostate hyperplasia and revealed the therapeutic potential... 相似文献
7.
Migyeong Jo Sanghwan Ko Bora Hwang Sung-Won Min Ji Yeon Ha Ji Chul Lee Se-Eun Jang Sang Taek Jung 《Biotechnology and bioengineering》2020,117(8):i-i
The immunoglobulin G (IgG) molecule has a long circulating serum half-life (~3 weeks) through pH- dependent FcRn binding-mediated recycling. To hijack the intracellular trafficking and recycling mechanism of IgG as a way to extend serum persistence of non-antibody therapeutic proteins, we have evolved the ectodomain of a low-affinity human FcγRIIa for enhanced binding to the lower hinge and upper CH2 region of IgG, which is very far from the FcRn binding site (CH2–CH3 interface). High-throughput library screening enabled isolation of an FcγRIIa variant (2A45.1) with 32-fold increased binding affinity to human IgG1 Fc (equilibrium dissociation constant: 9.04 × 10−7 M for wild type FcγRIIa and 2.82 × 10−8 M for 2A45.1) and significantly improved affinity to mouse serum IgG compared to wild type human FcγRIIa. The in vivo pharmacokinetic profile of PD-L1 fused with engineered FcγRIIa (PD-L1–2A45.1) was compared with that of PD-L1 fused with wild type FcγRIIa (PD-L1–wild type FcγRIIa) and human PD-L1 in mice. PD-L1–2A45.1 showed 11.7- and 9.7-fold prolonged circulating half-life (t1/2) compared to PD-L1 when administered intravenously and intraperitoneally, respectively. In addition, the AUCinf of PD-L1–2A45.1 was two-fold higher compared to that of PD-L1–wild type FcγRIIa. These results demonstrate that engineered FcγRIIa fusion offers a novel and successful strategy for prolonging serum half-life of therapeutic proteins. 相似文献
8.
Genetic localization and in vivo characterization of a Monascus azaphilone pigment biosynthetic gene cluster 总被引:1,自引:0,他引:1
9.
Jason L. Brown Neftali Sillero Frank Glaw Parfait Bora David R. Vieites Miguel Vences 《PloS one》2016,11(1)
Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800–1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of suitable habitat occupied by a species, is less expressed in amphibians than in reptiles, possibly reflecting their lower dispersal capacity. Taxonomic composition of communities assessed by field surveys is largely explained by bioclimatic regions, with communities from the dry and especially subarid biomes distinctly differing from humid and subhumid biomes. 相似文献