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91.
We isolated a Staphylococcus aureus strain HPC-250 producing antibacterial agent against Paenibacillus strain HPC-251. Both strains were isolated from the same environmental niche. The bacteria were identified using the partial
sequencing of their TA-cloned 16S rDNA. Spectrum of the antibacterial agent was also tested against routine observed bacteria
with drinking water contamination such as Escherichia coli, Salmonella, Pseudomonas, and Vibrio and these were found to be sensitive. Bacteria like Acinetobacter and Burkholderia were found to be resistant. The differential antibacterial activity of the HPC-250 was observed for the genus Bacillus where
B. subtilis remained resistant although B. sphaericus was sensitive. 相似文献
92.
The in vitro maturation, fertilization and development of Indian water buffalo (Bubalus sp.) cumulus oocyte complexes (COCs) to blastocysts were studied during culture, either in serum free tissue culture medium 199 (TCM 199) or Waymouth MB (WM). Based on different supplements added to these media, the experimental groups included: (a) no supplement (control); (b) hormones (FSH, LH and oestradiol) (c) Epidermal growth factor (EGF); (d) IGF-1; and (e) EGF + IGF-1. Experiments were conducted to note three end points: (1) nuclear maturation 24 h after culture (eight replicates); (2) fertilization 24 h after insemination (10 replicates); (3) development to blastocysts (nine replicates). The oocytes were cultured in groups of up to five per drop. Using a two-way (5 x 2) factorial model with interactions, the results were compared using generalized linear models with binomial errors and the logit link function. In experiment 1, the proportion of oocytes reaching metaphase II was higher for all the supplement treatments than the control treatment (t = 3.68, p < 0.0001). The proportion of oocytes reaching metaphase II was 74.7, 63.2, 64.7 and 81% with hormone (chi2 = 17.23, p < 0.0001), EGF (chi2 = 7.07, p = 0.007), IGF-1 (chi2 = 19.21, p = 0.002) and EGF + IGF-1 (chi2 = 33.04, p < 0.0001) supplementation, respectively, compared to 46.6% in the control (no supplement) group. Media did not have an effect on outcome. In experiment 2, the proportion of oocytes fertilized was significantly higher with hormones (31.0%, chi2 = 12.5, p = 0.0004), IGF-1 (35.7%, chi2 = 20.53, p < 0.0001), and the EGF + IGF-1 combination (49.7%, chi2 = 51.35, p < 0.0001) compared to control (16.2%). No significant effect of media was seen. In experiment 3, the proportion of oocytes that cleaved at 48 h after culturing was significantly higher for all supplement treatments compared to control. IGF-1 supplementation was the only treatment that did not produce a significantly higher rate of progression to blastocysts compared to the control. Once again, media had no effect on outcome. It was concluded that maturation, fertilization and development of buffalo oocytes were enhanced by all supplements tested. Enhancement was maximal with the combination of EGF+IGF-1. In contrast, no significant differences were found between the two types of media used. 相似文献
93.
Leese MP Leblond B Newman SP Purohit A Reed MJ Potter BV 《The Journal of steroid biochemistry and molecular biology》2005,94(1-3):239-251
Sulfamoylated derivatives of the endogenous estrogen metabolite 2-methoxyestradiol (2-MeOE2 (7)), such as 2-methoxy-3-O-sulfamoyl estrone (2-MeOEMATE (1)), display greatly enhanced activity against the proliferation of human cancer cells and inhibit steroid sulphatase (STS), another current oncology target. We explore here the effects of steroidal D-ring modification on the activity of such 2-substituted estrogen-3-O-sulfamates in respect of inhibition of tumour cell proliferation and steroid sulphatase. The novel 17-deoxy analogues of 2-MeOEMATE and the related 2-ethyl and 2-methylsulfanyl compounds showed greatly reduced inhibition of MCF-7 proliferation. Introduction of a 17alpha-benzyl substituent to such 2-substituted estrogen sulfamates also proved deleterious to anti-proliferative activity but could, in one case, enhance STS inhibition with respect to the parent substituted estrone sulfamate. In contrast, selected 17-oxime derivatives of 2-MeOEMATE displayed an enhanced anti-proliferative activity. These results illustrate that enhanced in vitro anti-cancer activity can be achieved in the 2-substituted estrogen sulfamate series and highlight, in particular, the importance of potential hydrogen bonding effects around the steroidal D-ring in the activity of these molecules. The SAR parameters established herein will assist the future design of anti-proliferative and anti-endocrine agents as potential therapeutics for both hormone dependent and independent cancers. 相似文献
94.
Purohit PK Inamdar MM Grayson PD Squires TM Kondev J Phillips R 《Biophysical journal》2005,88(2):851-866
The conjunction of insights from structural biology, solution biochemistry, genetics, and single-molecule biophysics has provided a renewed impetus for the construction of quantitative models of biological processes. One area that has been a beneficiary of these experimental techniques is the study of viruses. In this article we describe how the insights obtained from such experiments can be utilized to construct physical models of processes in the viral life cycle. We focus on dsDNA bacteriophages and show that the bending elasticity of DNA and its electrostatics in solution can be combined to determine the forces experienced during packaging and ejection of the viral genome. Furthermore, we quantitatively analyze the effect of fluid viscosity and capsid expansion on the forces experienced during packaging. Finally, we present a model for DNA ejection from bacteriophages based on the hypothesis that the energy stored in the tightly packed genome within the capsid leads to its forceful ejection. The predictions of our model can be tested through experiments in vitro where DNA ejection is inhibited by the application of external osmotic pressure. 相似文献
95.
In vitro Growth and Shoot Multiplication of Achras zapota in a Controlled Carbon Dioxide Environment 总被引:1,自引:0,他引:1
The culture vessels with multiplying shoots of Achras zapota L. on Schenk and Hildebrandt (SH) medium containing 8.88 M 6-benzylaminopurine (BAP) with or without sucrose were kept under varied CO2 concentrations ranging from 0.6 to 40.0 g m–3 using different concentrations of sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), potassium bicarbonate (KHCO3), and potassium carbonate (K2CO3) in small acrylic chambers. Complete absence of carbon source caused death of shoots within 20 d. Under elevated concentrations of CO2 (10.0 and 40.0 g m–3) the shoots grew photoautotrophically on sucrose-free medium. The growth of cultures was better at 40.0 g (CO2) m–3 than on 3.0 % sucrose under ambient air of growth room. However, the best response was obtained at 10.0 g (CO2) m–3 and 3.0 % sucrose where maximum number of shoots, shoot length, fresh and dry mass, total number of leaves and leaf area was observed. 相似文献
96.
Purohit S Brahmaraju M Palta A Shukla S Laloraya M Kumar PG 《Biochemical and biophysical research communications》2004,316(3):903-909
Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. We have examined the presence of a cadherin on spermatozoon and its possible involvement in sperm-oocyte interaction. Spermatozoa from fertile human subjects showed the presence of E-cadherin on its head domains, detectable only after permeabilization of the surface membranes. On the contrary, spermatozoa from oligozoospermic subjects did not possess E-cadherin on their principal acrosomal and equatorial domains. Immunoprecipitation and Western blot studies also showed the presence of E-cadherin in spermatozoa from fertile males and its absence in oligozoospermic males. Using RT-PCR, we detected E-cadherin message in the round cells of fertile males, which was absent in the cells from oligozoospermic males. The presence of anti-E-cadherin antibody brought about quantitative reduction in the sperm-oocyte binding in vitro. These observations indicate the possibility of the interplay of a cadherin-dependent homophilic and/or heterophilic adhesion interaction between spermatozoa and oocyte during fertilization. The absence of a key adhesion molecule in a human male infertility disorder points towards genetic defects causing failure in gamete interactions. 相似文献
97.
Tang X Maricic I Purohit N Bakamjian B Reed-Loisel LM Beeston T Jensen P Kumar V 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(11):7645-7655
Regulatory mechanisms involving CD8+ T cells (CD8 regulatory T cells (Tregs)) are important in the maintenance of immune homeostasis. However, the inability to generate functional CD8 Treg clones with defined Ag specificity has precluded a direct demonstration of CD8 Treg-mediated regulation. In the present study, we describe the isolation of functional lines and clones representing a novel population of TCRalphabeta+ Tregs that control activated Vbeta8.2+ CD4 T cells mediating experimental autoimmune encephalomyelitis. They express exclusively the CD8alphaalpha homodimer and recognize a peptide from a conserved region of the TCR Vbeta8.2 chain in the context of the Qa-1a (CD8alphaalpha Tregs). They secrete type 1 cytokines but not IL-2. CD8alphaalpha Tregs kill activated Vbeta8.2+ but not Vbeta8.2- or naive T cells. The CD8alphaalpha Tregs prevent autoimmunity upon adoptive transfer or following in vivo activation. These findings reveal an important negative feedback regulatory mechanism targeting activated T cells and have implications in the development of therapeutic strategies for autoimmune diseases and transplantation. 相似文献
98.
Effect of controlled carbon dioxide on in vitro shoot multiplication in Feronia limonia (L.) Swingle
The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was
insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO2), was found to be inadequate for sustainable growth and multiplication of shoots. The carbon dioxide enrichment promoted
shoot multiplication and overall growth. The promotory effect of CO2 was independent of the presence of sucrose in the medium. In the presence of both CO2 and sucrose, an additive effect was observed producing maximum shoot growth. In the absence of sucrose a higher concentration
of CO2 (10.0)g m−3 was required to achieve photoautotrophic shoot multiplication comparable to ambient air controls. Highest leaf area per shoot
cluster promoting shoot growth and multiplication was recorded under this treatment. Shoots growing on sucrose containing
medium under controlled CO2 environment of 0.6 g m−3 concentration evoked better response than ambient air controls (shoots growing on sucrose containing medium) in growth room.
This treatment produced the overall best response. The present study highlighted the possibility of photoautotrophic multiplication
which might prove useful for successful hardening and acclimatization in tissue culture plants. 相似文献
99.
Satpute RM Kashyap RS Kainthla RP Purohit HJ Taori GM Daginawala HF 《Indian journal of experimental biology》2006,44(5):367-370
Neurite outgrowth is essential for the communication of the nervous system. The rat Pheochromocytoma (PC12) cells are commonly used in the neuronal cell study. It is well known that exogenous stimuli such as Nerve Growth Factor (NGF) induce neurite outgrowth. In the present study it has been investigated whether or not the conditioned medium from human neuroblastoma cell line (IMR-32) and human glioblastoma cell line (U87MG) may augment neurite outgrowth in PC12 cells. PC12 were cultured with and without conditioned media of IMR-32 and U87MG. The result showed that both the conditioned media induce neurite outgrowth within 48 hr and stops further proliferation of PC12 cells. However no outgrowth was noted in PC12 cells incubated without conditioned medium. In conclusion, it is shown that both the conditioned media (IMR-32 and U87MG) have the potential to induce the neurite outgrowth in the PC12 cells. 相似文献
100.
Anju V Mudaliar Rajpal S Kashyap Hemant J Purohit Girdhar M Taori Hatim F Daginawala 《BMC neurology》2006,6(1):34-7