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排序方式: 共有701条查询结果,搜索用时 15 毫秒
71.
Kumar AK Ramachandran G Kumar P Kumaraswami V Swaminathan S 《MedGenMed : Medscape general medicine》2006,8(4):53
Patient adherence to treatment is an important factor in the effectiveness of antiretroviral regimens. Adherence to treatment could be monitored by estimation of antiretroviral drugs in biological fluids. We aimed to obtain information on the quantity and duration of excretion of lamivudine in urine following oral administration of a single dose of 300 mg and to assess its suitability for adherence monitoring purposes. Spot urine samples were collected before dosing and at 4, 8, 12, 24, 28, 32, 48, 72, and 96 hours post dosing from 10 healthy subjects, and lamivudine was estimated by high-pressure liquid chromatography (HPLC). Lamivudine values were expressed as a ratio of urine creatinine. About 91% of the ingested drug was excreted by 24 hours, and the concentration thereafter in urine was very negligible. A lamivudine value of 0.035 mg/mg creatinine or less at 48 hours is suggestive of a missed dose in the last 24 hours. The study findings showed that estimation of urine lamivudine in spot specimens could be useful in monitoring patient adherence to antiretroviral treatment. However, this needs to be confirmed on a larger sample size and among patients on once-daily and twice-daily treatment regimens. 相似文献
72.
73.
Bing Lai Rakhi Agarwal Lindsay D. Nelson Subramanyam Swaminathan Erwin London 《The Journal of membrane biology》2010,236(2):191-201
Botulinum neurotoxins (BoNTs) undergo low pH-triggered membrane insertion, resulting in the translocation of their light (catalytic)
chains into the cytoplasm. The T (translocation) domain of the BoNT heavy chain is believed to carry out translocation. Here,
the behavior of isolated T domain from BoNT type A has been characterized, both in solution and when associated with model
membranes. When BoNT T domain prepared in the detergent dodecylmaltoside was diluted into aqueous solution, it exhibited a
low pH-dependent conformational change below pH 6. At low pH the T domain associated with, and formed pores within, model
membrane vesicles composed of 30 mol% dioleoylphosphatidylglycerol/70 mol% dioleoylphosphatidylcholine. Although T domain
interacted with vesicles at low (50 mM) and high (400 mM) NaCl concentrations, the interaction required much less lipid at
low salt. However, even at high lipid concentrations pore formation was much more pronounced at low NaCl concentrations than
at high NaCl concentration. Increasing salt concentration after insertion in the presence of 50 mM NaCl did not decrease pore
formation. A similar effect of NaCl concentration upon pore formation was observed in vesicles composed solely of dioleoylphosphatidylcholine,
showing that the effect of NaCl did not solely involve modulation of electrostatic interactions between protein and anionic
lipids. These results indicate that some feature of membrane-bound T domain tertiary structure critical for pore formation
is highly dependent upon salt concentration. 相似文献
74.
75.
L-aspartate-alpha-decarboxylase (ADC) is a critical regulatory enzyme in the pantothenate biosynthetic pathway and belongs to a small class of self-cleaving and pyruvoyl-dependent amino acid decarboxylases. The expression level of ADC in Mycobacterium tuberculosis (Mtb) was confirmed by cDNA analysis, immunoblotting with an anti-ADC polyclonal antibody using whole cell lysate and immunoelectron microscopy. The recombinant ADC proenzyme from Mycobacterium tuberculosis (MtbADC) was overexpressed in E. coli and the protein structure was determined at 2.99 A resolution. The proteins fold into the double-psi beta-barrel structure. The subunits of the two tetramers (there are eight ADC molecules in the asymmetric unit) form pseudo fourfold rotational symmetry, similar to the E. coli ADC proenzyme structure. As pantothenate is synthesized in microorganisms, plants, and fungi but not in animals, structure elucidation of Mtb ADC is of substantial interest for structure-based drug development. 相似文献
76.
77.
The onset of hen egg white lysozyme aggregation on exposure to alkaline pH of 12.2 and subsequent slow growth of soluble lysozyme aggregates (at 298 K) was directly monitored by steady-state and time-resolved fluorescence anisotropy of covalently attached dansyl probe over a period of 24 h. The rotational correlation time accounting for tumbling of lysozyme in solution (40 microM) increased from approximately 3.6 ns (in pH 7) to approximately 40ns on exposure to pH 12.2 over a period of 6 h and remained stable thereafter. The growth of aggregates was strongly concentration dependent, irreversible after 60 min and inhibited by the presence of 0.9 M l-arginine in the medium. The day old aggregates were resistant to denaturation by 6 M guanidine.HCl. Our results reveal slow segmental motion of the dansyl probe in day old aggregates in the absence of L-arginine (0.9 M), but a much faster motion in its presence, when growth of aggregates is halted. 相似文献
78.
79.
Subramanian Swaminathan Vanamail Perumal Srividya Adinarayanan Krishnamoorthy Kaliannagounder Ravi Rengachari Jambulingam Purushothaman 《PLoS neglected tropical diseases》2012,6(11)
Background
Monitoring and evaluation guidelines of the programme to eliminate lymphatic filariasis require impact assessments in at least one sentinel and one spot-check site in each implementation unit (IU). Transmission assessment surveys (TAS) that assess antigenaemia (Ag) in children in IUs that have completed at least five rounds of mass drug administration (MDA) each with >65% coverage and with microfilaria (Mf) levels <1% in the monitored sites form the basis for stopping the MDA. Despite its rigour, this multi-step process is likely to miss sites with transmission potential (‘hotspots’) and its statistical assumptions for sampling and threshold levels for decision-making have not been validated. We addressed these issues in a large-scale epidemiological study in two primary health centres in Thanjavur district, India, endemic for bancroftian filariasis that had undergone eight rounds of MDA.Methodology/Principal Findings
The prevalence and intensity of Mf (per 60 µl blood) were 0.2% and 0.004 respectively in the survey that covered >70% of 50,363 population. The corresponding values for Ag were 2.3% and 17.3 Ag-units respectively. Ag-prevalence ranged from 0.7 to 0.9%, in children (2–10 years) and 2.7 to 3.0% in adults. Although the Mf-levels in the survey and the sentinel/spot check sites were <1% and Ag-level was <2% in children, we identified 7 “residual” (Mf-prevalence ≥1%, irrespective of Ag-status in children) and 17 “transmission” (at least one Ag-positive child born during the MDA period) hotspots. Antigenaemic persons were clustered both at household and site levels. We identified an Ag-prevalence of ∼1% in children (equivalent to 0.4% community Mf-prevalence) as a possible threshold value for stopping MDA.Conclusions/Significance
Existence of ‘hotspots’ and spatial clustering of infections in the study area indicate the need for developing good surveillance strategies for detecting ‘hotspots’, adopting evidence-based sampling strategies and evaluation unit size for TAS. 相似文献80.
Biofiltration for treating VOCs: an overview 总被引:1,自引:0,他引:1
Swaminathan Detchanamurthy Peter Alan Gostomski 《Reviews in Environmental Science and Biotechnology》2012,11(3):231-241
In this paper we present a review of Biofiltration, one of the air pollution control technologies (APCT) used to treat volatile organic compounds (VOCs) effectively. It also talks about the history of biofiltration, and also proposes few ideas for the future developments in the biofiltration research pertaining to VOC control. Moreover, the paper also discusses about various important physical, chemical and biological factors which affect the performance of a biofilter both directly and indirectly. This paper will be handier for those who are new to the field of biofiltration research for VOC treatment. 相似文献