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211.
212.
Randeep Singh Qamar Qureshi Kalyanasundaram Sankar Paul R. Krausman Surendra Prakash Goyal Kerry L. Nicholson 《Acta theriologica》2014,59(4):521-527
We used camera trapping in conjunction with a spatial explicit capture–recapture model to estimate striped hyena (Hyaena hyaena) density and occupancy models to investigate factors affecting striped hyena detection probabilities in Ranthambhore Tiger Reserve (RTR), Rajasthan, India. A sampling effort of 4,450 trap days/nights over 75 days yield 68 photo captures of 21 unique striped hyenas (based on individual markings and visual identification); the estimated striped hyena density was 5.49?±?1.27 individuals/100 km2. Results of our occupancy model suggested that a rugged terrain is an important factor that influences striped hyena detection probability. Correlation with striped hyena detection with human settlement provides evidence of social tolerance of striped hyena towards humans, and more occurrence of resources allowed coexistence of hyena in a human-dominated landscape. This elasticity (inhabited areas close to humans) demonstrated by striped hyenas is an exception among carnivore communities living in this semi-arid habitat. 相似文献
213.
Mitchell Lawrence Jones Jorge Gabriel Ganopolsky Alain Labbé Christopher Wahl Satya Prakash 《Applied microbiology and biotechnology》2010,88(2):401-407
This review describes the antimicrobial properties of nitric oxide (NO) and its application as an antimicrobial agent in different
formulations and medical devices. We depict the eukaryotic biosynthesis of NO and its physiologic functions as a cell messenger
and as an antimicrobial agent of the cell-mediated immune response. We analyze the antimicrobial activity of NO and the eukaryotic
protective mechanisms against NO for the purpose of delineating the therapeutic NO dosage range required for an efficacious
and safe antimicrobial activity. We also examine the role of NO produced by virulent bacteria in lessening the efficacy of
traditional antimicrobials. In addition, we discuss the efficacy of NO in the healing of infected wounds, describing different
NO-producing devices by category, analyzing therapeutic levels, duration of NO production, as well as commercial considerations.
Finally, we provide current and future prospects for the design and use of NO-producing devices. 相似文献
214.
Telugu BP Ezashi T Roberts RM 《The International journal of developmental biology》2010,54(11-12):1703-1711
Authentic or na?ve embryonic stem cells (ESC) have probably never been derived from the inner cell mass (ICM) of pig blastocysts, despite over 25 years of effort. Recently, several groups, including ours, have reported induced pluripotent stem cells (iPSC) from swine by reprogramming somatic cells with a combination of four factors, OCT4 (POU5F1)/SOX2/KLF4/c-MYC delivered by retroviral transduction. The porcine (p) iPSC resembled human (h) ESC and the mouse "Epiblast stem cells" (EpiSC) in their colony morphology and expression of pluripotent genes, and are likely dependent on FGF2/ACTIVIN/NODAL signaling, therefore representing a primed ESC state. These cells are likely to advance swine as a model in biomedical research, since grafts could potentially be matched to the animal that donated the cells for re-programming. The objective of the present work has been to develop na?ve piPSC. Employing a combination of seven reprogramming factors assembled on episomal vectors, we successfully reprogrammed porcine embryonic fibroblasts on a modified LIF-medium supplemented with two kinase inhibitors; CHIR99021, which inhibits GSK-3beta, and PD0325901, a MEK inhibitor. The derived piPSC bear a striking resemblance to na?ve mESC in colony morphology, are dependent on LIF to maintain an undifferentiated phenotype, and express markers consistent with pluripotency. They exhibit high telomerase activity, a short cell cycle interval, and a normal karyotype, and are able to generate teratomas. Currently, the competence of these lines for contributing to germ-line chimeras is being tested. 相似文献
215.
216.
S Patyar R Joshi DS Prasad Byrav A Prakash B Medhi BK Das 《Journal of biomedical science》2010,17(1):21
Resistance to conventional anticancer therapies in patients with advanced solid tumors has prompted the need of alternative
cancer therapies. Moreover, the success of novel cancer therapies depends on their selectivity for cancer cells with limited
toxicity to normal tissues. Several decades after Coley's work a variety of natural and genetically modified non-pathogenic
bacterial species are being explored as potential antitumor agents, either to provide direct tumoricidal effects or to deliver
tumoricidal molecules. Live, attenuated or genetically modified non-pathogenic bacterial species are capable of multiplying
selectively in tumors and inhibiting their growth. Due to their selectivity for tumor tissues, these bacteria and their spores
also serve as ideal vectors for delivering therapeutic proteins to tumors. Bacterial toxins too have emerged as promising
cancer treatment strategy. The most potential and promising strategy is bacteria based gene-directed enzyme prodrug therapy.
Although it has shown successful results in vivo yet further investigation about the targeting mechanisms of the bacteria are required to make it a complete therapeutic approach
in cancer treatment. 相似文献
217.
Prakash Peddi Charles W. Loftin Jennifer S. Dickey Jessica M. Hair Kara J. Burns Khaled Aziz Dave C. Francisco Mihalis I. Panayiotidis Olga A. Sedelnikova William M. Bonner Thomas A. Winters Alexandros G. Georgakilas 《Free radical biology & medicine》2010,48(10):1435-1443
DNA-dependent protein kinase (DNA-PK) is a key non-homologous-end-joining (NHEJ) nuclear serine/threonine protein kinase involved in various DNA metabolic and damage signaling pathways contributing to the maintenance of genomic stability and prevention of cancer. To examine the role of DNA-PK in processing of non-DSB clustered DNA damage, we have used three models of DNA-PK deficiency, i.e., chemical inactivation of its kinase activity by the novel inhibitors IC86621 and NU7026, knockdown and complete absence of the protein in human breast cancer (MCF-7) and glioblastoma cell lines (MO59-J/K). A compromised DNA-PK repair pathway led to the accumulation of clustered DNA lesions induced by γ-rays. Tumor cells lacking protein expression or with inhibited kinase activity showed a marked decrease in their ability to process oxidatively induced non-DSB clustered DNA lesions measured using a modified version of pulsed-field gel electrophoresis or single-cell gel electrophoresis (comet assay). In all cases, DNA-PK inactivation led to a higher level of lesion persistence even after 24–72 h of repair. We suggest a model in which DNA-PK deficiency affects the processing of these clusters first by compromising base excision repair and second by the presence of catalytically inactive DNA-PK inhibiting the efficient processing of these lesions owing to the failure of DNA-PK to disassociate from the DNA ends. The information rendered will be important for understanding not only cancer etiology in the presence of an NHEJ deficiency but also cancer treatments based on the induction of oxidative stress and inhibition of cluster repair. 相似文献
218.
Subhra Prakash Chakrabarty Hemalatha Balaram 《Biochimica et Biophysica Acta - Proteins and Proteomics》2010,1804(9):1743-1750
Reversible zinc chelation via thiol groups of cysteines leading to modulation of activity in redox regulated proteins forms a basis for switching on–off of various biochemical processes. Silent information regulator 2 (Sir2), a NAD+ dependent deacetylase, contains a non-catalytic zinc ion coordinated by thiol groups of cysteines. Using Plasmodium falciparum Sir2 (PfSir2), we have examined the effect of zinc removal on the structure and activity of this enzyme. Our studies show that the enzyme with high affinity for zinc exhibits partial collapse of structure upon removal of the metal ion. Zinc reconstitution of apo PfSir2 led to recovery of both structure and activity highlighting the reversibility of the process. 相似文献
219.
R. Arora S. Bhatia B. P. Mishra R. Sharma A. K. Pandey B. Prakash A. Jain 《Biochemical genetics》2010,48(3-4):304-311
The genetic polymorphism of the β-lactoglobulin (β-LG) gene was determined in 638 animals belonging to 15 native Indian sheep breeds reared in different agroecological regions for various production traits. Variants of β-LG were found using PCR–RFLP of genomic DNA. Rsa1 restriction enzyme digestion of a 120-bp PCR fragment of exon 2 of β-LG revealed two genetic variants, A (0.37) and B (0.63), and the three genotypes AA (0.175), AB (0.389), and BB (0.436). The differences in allelic frequency were not significant across the breeds, irrespective of their geographic origin and utility (χ2 test, P > 0.05). The pattern of occurrence of allelic variants revealed that the B allele was more frequent in the majority of the Indian breeds than in breeds reported from countries of Southwest Asia, Eastern and Central Europe, and the Mediterranean. A higher level of heterozygosity (0.422) was discerned, despite the declining status of several of the Indian breeds. These findings revealed that Indian sheep are predominantly of the β-LG B type. 相似文献
220.
Downy mildew (Peronospora plantaginis) caused two different types of infection in the floral parts of isabgol (Plantago ovata). Systemic infection resulted in long spikes bearing weak and sterile florets, which later turned black due to saprophytic
growth. Localised infection produced various symptoms ranging between normal flower opening and failure to bloom. Different
parts of infected flowers such as sepal, petal, filament and anther were reduced in size compared to healthy flowers. However,
gynoecium was elongated in localised infection. P. plantaginis induced gradual sterility of isabgol flowers. Androecium was affected more than the gynoecium was. Pollen number, pollen
viability and germination reduced drastically due to localised infection. On the contrary, there were no significant differences
between healthy and locally infected flowers in terms of stigma receptivity. In systemically infected spikes, bud development
was arrested leading to sterility. When localised disease severity was high, secondary systemic infection caused similar symptoms.
Microscopic observations showed presence of the pathogen in different parts of the flowers. Downy mildew adversely affected
seed yield and quality; producing seeds, which were smaller and lighter than the healthy ones and later, became black. Seed
yield was reduced by as much as 73.45 percent. Husk content per unit seed mass increased relatively as the total surface area
of infected seeds increased. 相似文献