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1.
Changes in the protein and steroid hormones of follicular fluid, aspirated from different follicles of sheep and human ovaries, have been measured and correlated with the size of the follicles. As the fluid contains a number of proteins, steroids have been measured directly and after ether extraction. The follicular fluid concentrations of progesterone and 17 beta-oestradiol measured directly in the fluid increased with the size of the follicles. The levels of free testosterone remained constant in all sizes of follicles, while those of bound hormone showed a 10- to 15-fold increase over the free testosterone concentrations in both the sheep and human follicular fluid. A decrease in the levels of bound testosterone in the fluid of large follicles (LFFL) coincided with the increase in bound 17 beta-oestradiol, suggesting the possible conversion of bound testosterone to oestrogen as the follicle attained maturity. The ratio of follicle-stimulating hormone (FSH) to luteinizing hormone (LH) varied in the fluid obtained from different size follicles, being 1:7 in small (SFFL), 1.3.5 in medium (MFFL) and 1:2.3 in large (LFFL) follicles of sheep ovaries. The LH content of follicular fluid of different size follicles appeared to be the same, with LFFL showing a minor increase over SFFL. In the human, the fluid from medium follicles contained very little LH compared to LFFL. These differences in the pattern of LH levels present in the fluid from different size follicles between human and sheep ovaries presumably reflect species variations in the entry of LH into the follicles. 相似文献
2.
Rakesh M. Vohra Uttam C. Banerjee Sunil Das Syamalima Dube 《Biotechnology letters》1989,11(12):851-854
Summary A highly active extracellular rifamycin oxidase was isolated fromCurvularia lunata var.aeri. The enzyme has a pH optimum of 6.5 and temperature optimum of 50°C. 相似文献
3.
R M Vohra 《Applied microbiology》1992,58(1):403-404
A simple method that allows easy identification of rifamycin B-producing strains is described. This method involves the use of an enzyme, rifamycin oxidase, which converts inactive rifamycin B to active rifamycin S. In this method, colonies to be tested are grown in pairs. The two colonies are then transferred to two plates seeded with a sensitive strain of Staphylococcus aureus, one plate of which contains the enzyme rifamycin oxidase. All paired colonies which show a larger inhibition zone diameter on the enzyme-containing plate are identified as rifamycin B producers. 相似文献
4.
T K Bhattacharya S S Misra Feroz D Sheikh S Dayal V Vohra P Kumar Arjava Sharma 《DNA sequence》2004,15(5-6):326-331
A study on butyrophilin (BTN) gene was conducted to detect variability at nucleotide level between cattle and buffalo. Hae III PCR-RFLP was carried out in crossbred cattle and it revealed polymorphism at this locus. Three genotypes namely, AA, BB and AB and two alleles were observed with frequencies 0.78, 0.17, 0.04 and 0.87, 0.13, respectively. The sequences of different cattle, buffalo and sheep breeds have been reported in the EMBL gene bank with accession numbers: AY491468 to AY491475. The nucleotides, which have been substituted from allele A to B, were found to be C to G (71st nucleotide), C to T (86th nucleotide), A to T (217th nucleotide), G to A (258th nucleotide), A to C (371st nucleotide) and C to T (377th nucleotide). The nucleotide substitution at 71st, 86th and 377th position of the fragment were expected to be a silent mutation where as nucleotide changes at 217th, 258th and 371st positions were expected to be substituted by lysine with arginine, valine with isoleucine and leucine with proline in allele B. The differences of nucleotides and amino acids between cattle, buffalo and sheep breeds have been revealed and on the basis of nucleotide as well as protein variability the phylogenetic diagram have been developed indicating closeness between cattle and buffalo. 相似文献
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Polygalacturonases are the pectinolytic enzymes that catalyze the hydrolytic cleavage of the polygalacturonic acid chain. In the present study, polygalacturonase from Aspergillus niger (MTCC 3323) was purified. The enzyme precipitated with 60% ethanol resulted in 1.68-fold purification. The enzyme was purified to 6.52-fold by Sephacryl S-200 gel-filtration chromatography. On SDS–PAGE analysis, enzyme was found to be a heterodimer of 34 and 69 kDa subunit. Homogeneity of the enzyme was checked by NATIVE-PAGE and its molecular weight was found to be 106 kDa. The purified enzyme showed maximum activity in the presence of polygalacturonic acid at temperature of 45 °C, pH of 4.8, reaction time of 15 min. The enzyme was stable within the pH range of 4.0–5.5 for 1 h. At 4 °C it retained 50% activity after 108 h but at room temperature it lost its 50% activity after 3 h. The addition of Mn2+, K+, Zn2+, Ca2+ and Al3+ inhibited the enzyme activity; it increased in the presence of Mg2+ and Cu2+ ions. Enzyme activity was increased on increasing the substrate concentration from 0.1% to 0.5%. The Km and Vmax values of the enzyme were found to be 0.083 mg/ml and 18.21 μmol/ml/min. The enzyme was used for guava juice extraction and clarification. The recovery of juice of enzymatically treated pulp increased from 6% to 23%. Addition of purified enzyme increased the %T650 from 2.5 to 20.4 and °Brix from 1.9 to 4.8. The pH of the enzyme treated juice decreased from 4.5 to 3.02. 相似文献
8.
Pawan K. Vohra Michael A. Thompson Venkatachalem Sathish Alexander Kiel Calvin Jerde Christina M. Pabelick Brij B. Singh Y.S. Prakash 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2013,1833(12):2953-2960
Exogenous brain-derived neurotrophic factor (BDNF) enhances Ca2 + signaling and cell proliferation in human airway smooth muscle (ASM), especially with inflammation. Human ASM also expresses BDNF, raising the potential for autocrine/paracrine effects. The mechanisms by which ASM BDNF secretion occurs are not known. Transient receptor potential channels (TRPCs) regulate a variety of intracellular processes including store-operated Ca2 + entry (SOCE; including in ASM) and secretion of factors such as cytokines. In human ASM, we tested the hypothesis that TRPC3 regulates BDNF secretion. At baseline, intracellular BDNF was present, and BDNF secretion was detectable by enzyme linked immunosorbent assay (ELISA) of cell supernatants or by real-time fluorescence imaging of cells transfected with GFP–BDNF vector. Exposure to the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFα) (20 ng/ml, 48 h) or a mixture of allergens (ovalbumin, house dust mite, Alternaria, and Aspergillus extracts) significantly enhanced BDNF secretion and increased TRPC3 expression. TRPC3 knockdown (siRNA or inhibitor Pyr3; 10 μM) blunted BDNF secretion, and prevented inflammation effects. Chelation of extracellular Ca2 + (EGTA; 1 mM) or intracellular Ca2 + (BAPTA; 5 μM) significantly reduced secreted BDNF, as did the knockdown of SOCE proteins STIM1 and Orai1 or plasma membrane caveolin-1. Functionally, secreted BDNF had autocrine effects suggested by phosphorylation of high-affinity tropomyosin-related kinase TrkB receptor, prevented by chelating extracellular BDNF with chimeric TrkB-Fc. These data emphasize the role of TRPC3 and Ca2 + influx in the regulation of BDNF secretion by human ASM and the enhancing effects of inflammation. Given the BDNF effects on Ca2 + and cell proliferation, BDNF secretion may contribute to altered airway structure and function in diseases such as asthma. 相似文献
9.
Depending upon the stimulus, neuronal cell death can either be triggered from the cell body (soma) or the axon. We investigated the origin of the degeneration signal in amyloid β (Aβ) induced neuronal cell death in cultured in vitro hippocampal neurons. We discovered that Aβ1–42 toxicity-induced axon degeneration precedes cell death in hippocampal neurons. Overexpression of Bcl-xl inhibited both axonal and cell body degeneration in the Aβ-42 treated neurons. Nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1) blocks axon degeneration in a variety of paradigms, but it cannot block neuronal cell body death. Therefore, if the neuronal death signals in Aβ1–42 toxicity originate from degenerating axons, we should be able to block neuronal death by inhibiting axon degeneration. To explore this possibility we over-expressed Nmnat1 in hippocampal neurons. We found that inhibition of axon degeneration in Aβ1–42 treated neurons prevented neuronal cell death. Thus, we conclude that axon degeneration is the key component of Aβ1–42 induced neuronal degeneration, and therapies targeting axonal protection can be important in finding a treatment for Alzheimer’s disease. 相似文献
10.
Manish Singh Ashima Singh Somanath Kundu Sandhya Bansal Avinash Bajaj 《生物化学与生物物理学报:生物膜》2013,1828(8):1926-1937
We synthesized four cationic bile acid based facial amphiphiles featuring trimethyl ammonium head groups. We evaluated the role of these amphiphiles for cytotoxic activities against colon cancer cells and their membrane interactions by varying charge, hydration and hydrophobicity. The singly charged cationic Lithocholic acid based amphiphile (LCA-TMA1) is most cytotoxic, whereas the triply charged cationic Cholic acid based amphiphile (CA-TMA3) is least cytotoxic. Light microscopy and Annexin-FITC assay revealed that these facial amphiphiles caused late apoptosis. In addition, we studied the interactions of these amphiphiles with model membrane systems by Prodan-based hydration, DPH-based anisotropy, and differential scanning calorimetry. LCA-TMA1 is most hydrophobic with a hard charge causing efficient dehydration and maximum perturbations of membranes thereby facilitating translocation and high cytotoxicity against colon cancer cells. In contrast, the highly hydrated and multiple charged CA-TMA3 caused least membrane perturbations leading to low translocation and less cytotoxicity. As expected, Chenodeoxycholic acid and Deoxycholic acid based amphiphiles (CDCA-TMA2, DCA-TMA2) featuring two charged head groups showed intermediate behavior. Thus, we deciphered that charge, hydration, and hydrophobicity of these amphiphiles govern membrane interactions, translocation, and resulting cytoxicity against colon cancer cells. 相似文献