Wynik wyszukiwania w bazie Polska Bibliografia Lekarska GBL

Zapytanie: SHARMA
Liczba odnalezionych rekordów: 6



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Tytuł oryginału: Carboxy terminal domain of the largest subunit of RNA polymerase II of Leishmania donovani has an unusually low number of phophorylation sites.
Autorzy: Dasgupta Arindam, Sharma Shalini, Das Aditi, Sarkar Dwijen, Majumder Hemanta K.
Źródło: Med. Sci. Monitor 2002: 8 (5) s.CR341-CR350, il., tab., bibliogr. 36 poz.
Sygnatura GBL: 313,278

Hasła klasyfikacyjne GBL:
  • genetyka
  • mikrobiologia

    Typ dokumentu:
  • praca doświadczalna
  • tytuł obcojęzyczny

    Wskaźnik treści:
  • zwierzęta

    Streszczenie angielskie: The C-terminal domain (CTD) of the largest subunit of RNA polymerase II in higher eukaryotes has an altered form in Leishmania donovani. To determine whether this is a general feature of the kinetoplastida and to investigate the role of this domain in parasitic RNA pol II transcription, we isolated the gene encoding RNA pol II LS (rpol IILS) and analyzed its C-terminal domain. The discreteness observed may be due to a functional constraint delineating parasite from host. The gene for L. donovani rpol IILS was picked up and sequenced. The CTD of L. donovani rpolIILS was purified as a His-tagged recombinant protein and phosphorylated with a crude kinase extract from L. donovani. An immunoblot analysis of the phosphorylated CTD and photo-crosslinked L. donovani nuclear extracts was done using anti-CTD antibody. The L. donovani rpol IILS is encoded by a single-copy gene. Its transcript is matured posttranscriptionally, with the mini-exon trans-spliced 397 bases upstream of the initiation site. The uniqueness of Leishmania rpol IILS CTD according to prediction analysis was corroborated with in vitro phosphorylation of the recombinant protein. Photoaffinity labelling of L. donovani nuclear run-on transcripts and immunoblot analysis using anti-CTD antibody could identify the active form of RNA polymerase II enzyme in this parasite. The L. donovani rpol IILS possesses a unique C-terminal extension lacking the characteristic repeats but containing serine residues as a potential phosphorylation site. Anti-CTD antiabody could recognize a single molecular species for the RNA pol II enzyme in L. donovani.

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    Tytuł oryginału: Betulinic acid, a potent inhibitor of eukaryotic topoisomerase I: identification of the inhibitory step, the major functional group responsible and development of more potent derivatives.
    Autorzy: Chowdhury Arnab Roy, Mandal Suparna, Mittra Bidyottam, Sharma Shalini, Mukhopadhyay Sibabrata, Majumder Hemanta K.
    Źródło: Med. Sci. Monitor 2002: 8 (7) s.BR254-BR260, il., tab., bibliogr. 29 poz.
    Sygnatura GBL: 313,278

    Hasła klasyfikacyjne GBL:
  • onkologia
  • genetyka
  • farmacja

    Typ dokumentu:
  • praca doświadczalna
  • tytuł obcojęzyczny

    Wskaźnik treści:
  • zwierzęta
  • myszy
  • in vitro

    Streszczenie angielskie: Background: Betulinic acid, a naturally abundant, plant derived, pentacyclic triterpenoid possesses anti-HIV, anti-malarial and anti-inflammatory properties and has recently emerged as a potent anti-tumor compound. This study explores the mode of action of betulinic acid on eukaryotic topoisomerase I and identifies the major functional group responsible along with more potent derivatives. Material/Methods: Topoisomerase I relaxation activity was electrophoretically measured by the decreased mobility of the relaxed monomers followed by ethidium bromide staining. DNA cleavage was studied by electrophoretic separation of the nicked monomers from the relaxed and supercoiled monomers in presence of ethidium bromide. In-vivo DNA cleavage was studied in blasted mouse splenocytes by the SDS-K+ trapping of 3H-DNA-topoisomerase I-camptothecin ternary complex. Results: Betulinic acid exerts its inhibitory effect by preventing topoisomerase I-DNA interaction as a result of which the 'cleavable complex' is not formed. In consequence, it also acts as an antagonist to camptothecin-mediated cleavage. A series of analogues modified at C-3, C-17 and C-20 positions of betulinic acid were subsequently assayed for inhibition of topoisomerase I catalytic activity. Replacemnt of the 17-carboxylic group reduces the inhibitory effect and decarboxylation leads to the complete loss of inhibitory effect. Conclusion: This study is the first detail report of betulinic acid as a very potent inhibitior of eukaryotic topoisomerase I and highlights the necessity of the carboxylic functional group. Dihydro betulinic acid is the most potent (IC50 = 0.5 ćM) pentacyclic triterpenoid to inhibit eukaryotic topoisomerase I till date and can be exploited as a strong candidate for anti-tumor drug designing.

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    Tytuł oryginału: Functional reconstitution of Ral-binding GTPase activating protein, RLIP76, in proteoliposomes catalyzing ATP-dependent transport of glutathione conjugate of 4-hydroxynonenal.
    Autorzy: Sharma Rajendra, Sharma Abha, Yang Yusong, Awasthi Sanjay, Singhal Sharad S., Zimniak Piotr, Awasthi Yogesh C.
    Źródło: Acta Bioch. Pol. 2002: 49 (3) s.693-701, il., bibliogr. s. 700-701
    Sygnatura GBL: 303,116

    Hasła klasyfikacyjne GBL:
  • mikrobiologia

    Typ dokumentu:
  • praca doświadczalna
  • tytuł obcojęzyczny

    Streszczenie angielskie: Earlier studies from our laboratories have shown that RLIP76, a previously described Ral-binding GTpase activating protein (Jullien-Flores et al., 1995, J. Biol. Chem. 270: 22473), is identical with the xenobiotic transporter DNP-SG ATPase, adn can catalyze ATP-dependent transport of glutathione-conjugates as well as doxorubin (Awasthi et al., 2000, Biochemistry, 39: 9327). We have now reconstituted purified bacterially expressed RLIP76 in proteoliposomes, and have studied ATP-dependent uptake of the glutathione conjugate of 4-hydroxynonenal (GS-HNE) by these vesicles. Results of these studies show that RLIP76 reconstituted in proteoliposomes catalyzes ATP-dependent transport of GS-HNE against a concentration gradient. The transport of GS-HNE is saturable with respect to ATP as well as GS-HNE with Km values of 1.4 mM and 2.5 ćM, respectively. These studies demonstrate that RLIP76 mediates active transport of GS-HNE, adn are consistent with our previous work showing that RLIP76-mediated efflux of GS-HNE regulates the intracellular concentration of 4-HNE and thereby affects 4-HNE mediated signaling.

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    Tytuł oryginału: Patient, community and clinician perceptions of the quality of life associated with diabetes mellitus.
    Autorzy: Landy Jennifer, Stein Joshua D., Brown Melissa M., Brown Gary C., Sharma Sanjay
    Źródło: Med. Sci. Monitor 2002: 8 (8) s.CR543-CR548, tab., bibliogr. 27 poz.
    Sygnatura GBL: 313,278

    Hasła klasyfikacyjne GBL:
  • endokrynologia

    Typ dokumentu:
  • praca epidemiologiczna
  • tytuł obcojęzyczny

    Wskaźnik treści:
  • ludzie

    Streszczenie angielskie: Background: A study was undertaken to assess the quality of life of patients with type 1 and type 2 diabetes mellitus and to ascertain whether clinicians and non-diabetic respondents from the general public have similar views of the impact of diabetes upon health-related quality of life. Material/Methods: Time trade off utility values were generated from a standardized time-tradeoff questionnaire. Three hundred and fifty-two individuals with type 1 or type 2 diabetes mellitus, 157 non-diabetic participants from the general public (community), and 61 healt care clinicians participated in the study. Results: The mean utility score for diabetic patients was 0.889 and the median utility score was 1.000. The mean utility score for clinicians was 0.861, with a median value of 0.894, while the respective mean and median scores for the general public were 0.919 and 0.953. There was a significant difference between the disribution of the means of socres of clinicians and patients as well as between clinicians and the general public. There was no significant difference between the utility scores of patients and the general public. Within the group of diabetic patients, there was no significant difference in utility scores between type 1 and type 2 diabetics. Conclusions: Clinicians tended to over emphasize the impact that diabetes mellitus has on health related quality of life, while the non-diabetic publics' utility values are more closely correlated with those of diabetics themselves. We conclude that there is a significant difference in how clinicians, diabetics and the general public perceive the effect diabetes has upon quality of life.

    5/6

    Tytuł oryginału: Transport functions and physiological significance of 76 kDa Ral-binding GTPase activating protein (RLIP76).
    Autorzy: Awasthi Sanjay, Sharma Rajendra, Yang Yusong, Singhal Sharad S., Pikula Sławomir, Bandorowicz-Pikula Joanna, Singh Shivendra V., Zimniak Piotr, Awasthi Yogesh C.
    Źródło: Acta Bioch. Pol. 2002: 49 (4) s.855-867, il., tab., bibliogr. s. 863-867
    Sygnatura GBL: 303,116

    Typ dokumentu:
  • tytuł obcojęzyczny

    Streszczenie angielskie: We have recently demonstrated that a previously known Ral-binding GTPase activating protein, RLIP76, can also catalyze ATP-dependent transport of various structurally unrelated xeno- and endobiotics irrespective of their net charge (Awasthi et al., 2000, Biochemistry, 39: 9327). RLIP76 is a non-ATP binding cassette (ABC) protien but it has two ATP-binding sites and shows basal ATPase activity which is stimulated in the presence of its transport substrates (allocrites) such as doxorubicin (DOX) and S-(2,4-dinitrophenyl) glutathione (DNP-SG). Proteoliposomes reconstituted with purified RLIP76 catalyze ATP-dependent, saturable transport of DOX, as well as of glutathione-conjugates including leukotrienes (LTC4) and the GSH-conjugate of 4-hydroxynonenal (GS-HNE). In erythrocytes the majority of transport activity for DOX, GS-HNE, and LTCA is a ccounted for by RLIP76. Cells exposed to mild oxidative stress show a rapid and transient induction of RLIP76 resulting in an increased efflux of GS-HNE and acquire resistance to oxidative stress mediated toxicity and apoptosis. Cells transfected with RLIP76 acquire resistance to DOX through increased efflux of the drug suggesting its possible role in the mechanisms of drug-resistance. In this article, we discuss the significance of transport functions of RLIP76 highlighting its role in the defense mechanisms against oxidative injury, and modulation of signaling mechanisms.

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    Tytuł oryginału: Potential of CT-scan based tumor volume as a response indicator in chemotherapy of advanced epithelial ovarian cancer.
    Autorzy: Kumar Pratik, Rehani Madan Mohan, Kumar Lalit, Sharma Raju, Bhatla Neerja, Singh Rajvir, Sundaram K. Ramaiyer
    Źródło: Med. Sci. Monitor 2002: 8 (10) s.CR667-CR674, il., tab., bibliogr. 27 poz.
    Sygnatura GBL: 313,278

    Hasła klasyfikacyjne GBL:
  • onkologia
  • ginekologia i położnictwo

    Typ dokumentu:
  • praca kliniczna
  • tytuł obcojęzyczny

    Wskaźnik treści:
  • ludzie
  • płeć żeńska

    Streszczenie angielskie: Background: Response prediction in patients undergoing chamotherapy for ovarian cancer is an important issue, since the cure rate is only about 15 - 20 p.c. We attempted to develop a semi-empirical model to predict response in individual cases after the first cycle of chemotherapy. Material/Methods: This prospective study included 51 cases of advanced ovarian cancer. A method was standardized to estimate ovarian tumor volume accurately from CT scan films. This permits the inclusion of patients who have undergone CT scan elsewhere. Patients underwent 4 - 6 cycles of chemotherapy and tumor volume was estimated after each cycle. This yielded a tumor regression curve for each patient. Results: Percent reduction in tumor volume after the first chemo-cycle was a significant prognostic factor in multivariate analysis. Depending upon the rate of regression patients could be classified into Fast Regressing FR (n = 29) and Moderately Regressing MR (n = 16), whereas 6 patients showed Progressive Disease (PD) despite ongoing chemotherapy. The median survivals for the FR, MR and PD groups were 29.3, 18.9 adn 8.5 months respectively. We found that 'percent reduction in volume after firs chemo-cycle' could categorize a patient as FR/MR/PD correctly in 94.1 p.c. of cases. This parameter could also detect 5 out of 6 inherently resistand PD cases, who would otherwise undergo further chemotherapy, since early detection of resistance by clinical monitoring is quite difficult.

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