Gut microbiota play important role in maintaining health. Probiotics are believed to augment it further. We aimed at comparing effects of probiotics, Lactobacillus acidophilus (LA) and Bacillus clausii (BC) (a) on the gut microbiota abundance and diversity and (b) their contributions to control intestinal dysbiosis and inflammation in Th1- and Th2-biased mice following Salmonella infection. We report how could gut microbiota and the differential immune bias (Th1 or Th2) of the host regulate host responses when challenged with Salmonella typhimurium in the presence and absence of either of the probiotics. LA was found to be effective in ameliorating the microbial dysbiosis and inflammation caused by Salmonella infection, in Th1 (C57BL/6) and Th2 (BALB/c)-biased mouse. BC was able to ameliorate Salmonella-induced dysbiosis and inflammation in Th2 but not in Th1-biased mouse. These results may support probiotics LA as a treatment option in the case of Salmonella infection.
Summary Long-term monolayer cultures of adult rat hepatocytes were tested for their ability to glucuronize phenol red and to maintain
initial levels of cell proteins, glucose consumption, and lactic acid production. Lactate dehydrogenase leakage served as
an index of culture status because a high value indicates cell death. Three tissue culture (TC) media formulations were the
main variables introduced to determine ideal conditions for cell survival in vitro. Investigations of long-term cultures were
preceded by studies of hepatocyte attachment to polystyrene surfaces. This attachment was influenced by the amount of substrate
deposited and the number of cells seeded, but not by the uniformity of the substrate coating. A statistical analysis of our
data revealed that in the absence of fetal bovine serum (FBS), air dried collagen (ADC) and Biomatrix (BMX) were superior
to saline precipitated collagen and fibronectin as attachment substrates. In the presence of 10% FBS, all of the substrates
performed equally.
Chee's Medium (CEM) proved to be the best for preserving cell proteins over a time course of 28 d and Williams' E medium also
performed adequately up to 14 d. The glucuronization of phenol red was at 50% of initial values at Day 7 in CEM-ADC hepatocytes
in contrast to 30% for cells in Williams' E medium and 5% for cells grown in Waymouth's. At 14 d glucuronization was still
present at 40% of original values in CEM-ADC cells but had ceased in the other two media. When BMX was used, none of the TC
media supported glucuronization levels comparable to ADC cells.
This research was supported in part by grant 1R01-AM-26520 from the National Institute of Arthritis, Diabetes and Digestive
Kidney Diseases, NIH, Bethesda, Maryland. 相似文献
The thermoalkalophilic Bacillus halodurans JB 99 cells known for production of novel thermostable alkaline keratinolytic protease were immobilized in calcium alginate
matrix. Batch and repeated batch cultivation using calcium alginate immobilized cells were studied for alkaline protease production
in submerged fermentation. Immobilized cells with 2.5% alginate and 350 beads/flask of initial cell loading showed enhanced
production of alkaline protease by 23.2% (5,275 ± 39.4 U/ml) as compared to free cells (4,280 ± 35.4 U/ml) after 24 h. In
the semicontinuous mode of cultivation, immobilized cells under optimized conditions produced an appreciable level of alkaline
protease in up to nine cycles and reached a maximal value of 5,975 U/ml after the seventh cycle. The enzyme produced from
immobilized cells efficiently degraded chicken feathers in the presence of a reducing agent which can help the poultry industry
in the management of keratin-rich waste and obtaining value-added products. 相似文献
During V(D)J recombination, RAG (recombination-activating gene) complex cleaves DNA based on sequence specificity. Besides its physiological function, RAG has been shown to act as a structure-specific nuclease. Recently, we showed that the presence of cytosine within the single-stranded region of heteroduplex DNA is important when RAGs cleave on DNA structures. In the present study, we report that heteroduplex DNA containing a bubble region can be cleaved efficiently when present along with a recombination signal sequence (RSS) in cis or trans configuration. The sequence of the bubble region influences RAG cleavage at RSS when present in cis. We also find that the kinetics of RAG cleavage differs between RSS and bubble, wherein RSS cleavage reaches maximum efficiency faster than bubble cleavage. In addition, unlike RSS, RAG cleavage at bubbles does not lead to cleavage complex formation. Finally, we show that the "nonamer binding region," which regulates RAG cleavage on RSS, is not important during RAG activity in non-B DNA structures. Therefore, in the current study, we identify the possible mechanism by which RAG cleavage is regulated when it acts as a structure-specific nuclease. 相似文献
Spentwash is one of the most complex and cumbersome wastewater with very high BOD, COD and other organic and inorganic toxic
constituents. It is dark brown colored and difficult to treat by normal biological process such as activated sludge or anaerobic
lagooning. The color is due to the presence of melanoidins, caramels and other polymers. These compounds have anti oxidant
properties which render them toxic to microorganisms. Spentwash disposal into the environment is hazardous and has a considerable
pollution potential. It affects the aesthetic merit. Its decolorization by physical or chemical methods have been investigated
and were found unsuitable. In the recent past, increasing attention has been directed towards utilizing microbial activity
for decolorization of spentwash. This review reveals various groups of microorganisms which have potential in spentwash decolorization.
The role of enzymes in decolorization and the microbial degradation of individual compounds imparting color to spentwash are
also discussed. 相似文献
Summary Multiple shoots were induced from cotyledonary nodes of grasspea (Lathyrus sativus L.) derived from 7-d-old in vitro seedlings on Murashige and Skoog (MS) medium containing N6-benzyladenine (BA), kinetin, or thidiazuron, BA being the most effective. Among the five genotypes tested, shoot proliferation
frequency was the highest (93.3%) for IC-120487, giving the maximum number of shoots (11.3 shoots per explant) on MS medium
augmented with 2.0 mgl−1 (8.87 μM) BA. Shoot cultures were established by repeatedly subculturing the original cotyledonary nodes on fresh medium after each
harvest of the newly formed shoots. Thus 30–40 shoots were obtained in 2 mo. from a single cotyledonary node. Up to 81.8%
of the shoots developed roots following transfer to half-strength MS medium containing 0.5 mgl−1 (2.85 μM) indole-3-acetic acid. Plantlets were successfully acclimatized and established in soil. 相似文献
Diversity and phylogenetic relationship between four closely related Salacia species, i.e., Salacia chinensis, Salacia macrosperma, Salacia fruticosa and Salacia oblonga, collected from the Western Ghats of Karnataka, India, was assessed. Ten each of RAPD and ISSR primers generated a total of 76 and 68 loci, generating polymorphisms of 92.21 and 89.71%, respectively. Maximum likelihood analysis of the ITS sequences revealed three clades. Dendrogram analyses of RAPD and ISSR revealed two and four clusters, respectively. Overall polymorphism revealed by RAPD was 41.45?±?10%, ISSR was 33.58?±?6.52%, and ITS was 25.50?±?17.25%. Molecular variance revealed significant variance within and among the Salacia species. Tajima’s D neutrality test and Fu’s Fs were negative for all four species, implying presences of rare alleles and population expansion. Comparative study of RAPD, ISSR and ITS for Salacia species has given an insight into the efficiency of each technique in detecting diversity within and among the population sampled in the Western Ghats of Karnataka.
Uromodulin, originally identified as an immunosuppressive glycoprotein in the urine of pregnant women, has been previously shown to be identical to human Tamm-Horsfall glycoprotein (THP). THP is synthesized by the kidney and localizes to the renal thick ascending limb and early distal tubule. It is released into the urine in large quantities and thus represents a potential candidate for a protein secreted in a polarized fashion from the apical plasma membrane of epithelial cells in vivo. After introduction of the full-length cDNA encoding uromodulin/THP into HeLa, Caco-2, and Madin-Darby canine kidney cells by transfection, however, the expressed glycoprotein was almost exclusively cell-associated, as determined by immunoprecipitation after radioactive labeling of the cells. By immunofluorescence, THP was localized to the plasma membranes of transfected cells. In transfected cell extracts, THP also remained primarily in the detergent phase in a Triton X-114 partitioning assay, indicating that it has a hydrophobic character, in contrast to its behavior after isolation from human urine. Triton X-114 detergent-associated THP was redistributed to the aqueous phase after treatment of cell extracts with phosphatidylinositol-specific phospholipase C. Treatment of intact transfected HeLa cells with phosphatidylinositol-specific phospholipase C also resulted in the release of THP into the medium, suggesting that it is a glycosylphosphatidylinositol (GPI)-linked membrane protein. Similar to other known GPI-linked proteins, uromodulin/THP contains a stretch of 16 hydrophobic amino acids at its extreme carboxyl terminus which could function as a GPI addition signal and was shown to label with [3H]ethanolamine. The results indicate that THP is a member of this class of lipid-linked membrane proteins and is released into the urine after the loss of its hydrophobic anchor, probably by the action of a phospholipase or protease. 相似文献
RAPD based fingerprinting of 21 serovars of Bacillus thuringiensis (Bt) representing different serotypes was performed using 19 random decamer primers. A total of 172 polymorphic fragments, ranging in size from 161-2789 bp, were amplified from 13 of the 19 primers. Pairwise genetic similarity analysis revealed very low similarity values, ranging from 3-68%, among the serovars of Bt, indicating high genetic divergence. Nineteen serovars of Bt fell in two major clusters and remaining two formed solitary clusters in the dendogram. Clustering of Bt strains established genetic relatedness between serovars and serotypes. It has been suggested that RAPD analysis can be used for genotypic characterization of Bt to complement flagellar serotyping. 相似文献