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991.
Detection of specificity of a new antigen in Candida tropicalis and its evaluation by taxonomic DNA analyses 总被引:1,自引:0,他引:1
Monospecific factor serum for identifying Candida tropicalis was obtained either from rabbit antiserum to heated cells of C. tropicalis M 1519 (S 96) or from antiserum to C. tropicalis IFO 1400, by adsorption with heated cells of Candida albicans serotype A, or C. albicans (A) and Candida krusei, respectively. We designated this adsorbed serum factor t serum. The monospecific factor serum reacted with 31 out of 32 strains of C. tropicalis, only when tested on heat-treated cell antigens, whereas it did not react with any of 72 strains of the six other medically important species of Candida. The morphological and physiological characteristics of the one strain of C. tropicalis that did not react with the factor t serum, designated the t- -strain, were shown to be similar to those of the type strain of C. tropicalis by most of the methods employed for identifying Candida. Therefore, cell wall mannan from the t- -strain was compared with that from several typical strains of C. tropicalis for its specificity by the precipitation reaction and also for its 1H-nuclear magnetic resonance spectrum. The results showed that these mannans are similar to each other serologically and physicochemically, suggesting that the new antigen t is not mannan. Taxonomic characterization of the t-- and several typical strains of C. tropicalis was carried out by determining the mol% G+C of their DNA and also their DNA homology. Although the mol% G+C values of four typical strains of C. tropicalis were fairly similar (35.2 to 36.2 mol% by the Tm method and 35.5 to 36.4 mol% by the HPLC method), the t- -strain had a G+C content of 44.1 (Tm) and 43.3 (HPLC) mol%. Furthermore, the DNAs of the t- -strain and the type strain of C. tropicalis showed only 18.2% relatedness. These results suggest that the antigen corresponding to serum factor t exists only in the cell wall of C. tropicalis strains, not in those of the other medically important Candida, and that the t- -strain should not be classified as C. tropicalis. In conclusion, the taxonomic value and usefulness of factor t serum is primarily for differentiating C. tropicalis from C. albicans serotype A serologically. 相似文献
992.
Regulation of E- and P-cadherin expression correlated with melanocyte migration and diversification. 总被引:3,自引:0,他引:3
Melanocytes (Mc) and their progenitors melanoblasts (Mb) are derived from the neural crest and migrate along the dorsolateral pathway to colonize the dermis, the epidermis, and finally the hair matrix. To examine the involvement of cadherins in the migration of Mc lineage cells, we combined flow cytometric analysis of dissociated live cells with immunohistochemical staining of tissue sections to quantify the level of cadherin expression on the surface of Mb/Mc. At 11.5 days postcoitum, Mb are in the dermis and are E-cadherin(-)P-cadherin(-) (E-cad(-)P-cad(-)). During the next 48 h, a 200-fold increase of E-cadherin expression is induced on the surface of Mb prior to their entry into the epidermis, thereby forming a homogeneous E-cad(high)P-cad(-/low) population. The cadherin expression pattern then diversifies, giving rise to three populations, an E-cad(-)P-cad(-) dermal population, E-cad(high)P-cad(low) epidermal population, and E-cad(-)P-cad(med-high) follicular population. In all three populations, the patterns of expression are region-specific, being identical with those of surrounding cells such as keratinocytes and fibroblasts, and are preserved before and after pigmentation. While most of the epidermal Mb/Mc disappear after the neonatal stage in normal mice, forced expression of steel factor in the epidermis of transgenic mice promotes survival of epidermal Mb/Mc, maintaining epidermal-type cadherin expression pattern (E-cad(high)P-cad(low)) throughout the postnatal life. These findings indicate the involvement of extrinsic cues in coordinating the cadherin expression pattern of Mb/Mc and suggest a role for E- and P-cadherins in guiding Mc progenitors to their final destinations. 相似文献
993.
S Minoshima M Amagai J Kudoh R Fukuyama T Hashimoto T Nishikawa N Shimizu 《Cytogenetics and cell genetics》1991,57(1):30-32
Chromosome mapping of the human gene encoding the 230-kDal autoantigen of an autoimmune skin disease, bullous pemphigoid, was performed using flow-sorted human chromosomes of cells of normal karyotype and cells carrying a reciprocal translocation t(6;16)(q15;q24). The cDNA of the autoantigen hybridized with intact chromosome 6 and translocation chromosome 6p- (6pter----q15::16q24----qter). The gene (BPA230) was located to the chromosome region 6pter----q15. 相似文献
994.
995.
Isolation of phospholipase d producing microorganisms with high transphosphatidylation activity 总被引:5,自引:0,他引:5
The transphosphatidylation and hydrolytic activities of phospholipase d in culture supernatants of soil isolates were evaluated by a specific spectrophotometric method for quantitative determination using an artifical substrate, phosphatidyl-p-nitrophenol. Phospholipase d from strain TH-2 showed the highest specific activity and ratio of transphosphatidylation activity to hydrolytic activity among those from the eight soil isolates and commercial Actinomycetes phospholipase d. 相似文献
996.
Takeshi Kon Masahiro Nohara Yusuke Yamanoue Yoshihiro Fujiwara Mutsumi Nishida Teruaki Nishikawa 《BMC evolutionary biology》2007,7(1):127
Background
The lancelet Asymmetron inferum (subphylum Cephalochordata) was recently discovered on the ocean floor off the southwest coast of Japan at a depth of 229 m, in an anaerobic and sulfide-rich environment caused by decomposing bodies of the sperm whale Physeter macrocephalus. This deep sulfide-rich habitat of A. inferum is unique among the lancelets. The distinguishing adaptation of this species to such an extraordinary habitat can be considered in a phylogenetic framework. As the first step of reconstruction of the evolutionary processes in this species, we investigated its phylogenetic position based on 11 whole mitochondrial genome sequences including the newly determined ones of the whale-fall lancelet A. inferum and two coral-reef congeners. 相似文献997.
998.
Yoshio Iguchi Sakurako Kosugi Hiromi Nishikawa Ziqiao Lin Yoshio Minabe Shigenobu Toda 《PloS one》2014,9(12)
Exposure of neonates to oxidative stress may increase the risk of psychiatric disorders such as schizophrenia in adulthood. However, the effects of moderate oxidative stress on the adult brain are not completely understood. To address this issue, we systemically administrated 2-cyclohexen-1-one (CHX) to adult rats to transiently reduce glutathione levels. Repeated administration of CHX did not affect the acquisition or motivation of an appetitive instrumental behavior (lever pressing) rewarded by a food outcome under a progressive ratio schedule. In addition, response discrimination and reversal learning were not affected. However, acute CHX administration blunted the sensitivity of the instrumental performance to outcome devaluation, and this effect was prolonged in rats with a history of repeated CHX exposure, representing pro-depression-like phenotypes. On the other hand, repeated CHX administration reduced immobility in forced swimming tests and blunted acute cocaine-induced behaviors, implicating antidepressant-like effects. Multivariate analyses segregated a characteristic group of behavioral variables influenced by repeated CHX administration. Taken together, these findings suggest that repeated administration of CHX to adult rats did not cause a specific mental disorder, but it induced long-term alterations in behavioral and cognitive functions, possibly related to specific neural correlates. 相似文献
999.
Ikuko Kato Susan Land Adhip P. Majumdar Jill Barnholtz-Sloan Richard K. Severson 《Cancer epidemiology》2010,34(3):291-297
Purpose Fat absorption may play a crucial role in colorectal carcinogenesis by determining intra-colonic exposure to potentially carcinogenic lipid metabolites. Methods We conducted a population-based case–control study that included 1163 cases and 1501 controls to examine whether individuals who carry genetic variants associated with lower lipid absorption have a higher risk of colorectal cancer. Using Taqman assay, we determined FABP2 alanine (A)/threonine (T) polymorphism at codon 54 in exon-2 and APOE isoforms. Multivariable odds ratios (OR) and 95% confidence intervals (CI) were calculated by unconditional logistic regression models, assuming FABP2 A54 and APO non-E4 as high risk alleles. Results We found no associations with either of the polymorphisms. The OR associated with FABP2 A54 homozygotes compared with the others was 1.01 (95% CI; 0.86–1.45) and that for non-ApoE4 carriers compared with carries was 0.95 (95% CI; 0.80–1.13). However, there was a statistically significant negative interaction between total fat intake and FABP2 AA genotypes (p = 0.025), indicating that the risk of colorectal cancer associated with this polymorphism is higher in the subjects with lower fat intake. Conclusions These results suggest that these SNPs may not be useful in predicting colorectal cancer risk in populations with high fat intake. 相似文献
1000.