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1.
Sridhar R Perumal PT Etti S Shanmugam G Ponnuswamy MN Prabavathy VR Mathivanan N 《Bioorganic & medicinal chemistry letters》2004,14(24):6035-6040
In a SAR study, we have synthesized a few 1H-pyrazole carboxylate related microbicides using Vilsmeier reagent. The anti-microbial screening results of 1H-pyrazole-3-carboxylate are reported here for the first time. The effect of 1H-pyrazole carboxylates on the mycelial growth of plant pathogenic fungi is revealed. The first X-ray structure in the family of microbicidal 1H-pyrazole-4-carboxylates is presented. 相似文献
2.
Virtually all of the eukaryotic low-molecular weight protein tyrosine phosphatases (LMW PTPases) studied to date contain a conserved, high-pK(a) histidine residue that is hydrogen bonded to a conserved active site asparagine residue of the phosphate binding loop. However, in the putative enzyme encoded by the genome of the trichomonad parasite Tritrichomonas foetus, this otherwise highly conserved histidine is replaced with a glutamine residue. We have cloned the gene, expressed the enzyme, demonstrated its catalytic activity, and examined the structural and functional roles of the glutamine residue using site-directed mutagenesis, kinetic measurements, and NMR spectroscopy. Titration studies of the two native histidine residues in the T. foetus enzyme as monitored by (1)H NMR revealed that H44 has a pK(a) of 6.4 and H143 has a pK(a) of 5.3. When a histidine residue was introduced in place of the native glutamine at position 67, a pK(a) of 8.2 was measured for this residue. Steady state kinetic methods were employed to study how mutation of the native glutamine to alanine, asparagine, and histidine affected the catalytic activity of the enzyme. Examination of k(cat)/K(m) showed that Q67H exhibits a substrate selectivity comparable to that of the wild-type (WT) enzyme, while Q67N and Q67A show reduced activity. The effect of pH on the reaction rate was examined. Importantly, the pH-rate profile of the WT TPTP enzyme revealed a much more clearly defined acidic limb than that which can be observed for other wild-type LMW PTPases. The pH-rate curve of the Q67H mutant shows a shift to a lower pH optimum relative to that seen for the wild-type enzyme. The Q67N and Q67A mutants showed curves that were shifted to higher pH optima. Although the active site of this enzyme is likely to be similar to that of other LMW PTPases, the hydrogen bonding and electrostatic changes afford new insight into factors affecting the pH dependence and catalysis by this family of enzymes. 相似文献
3.
Bea Vuylsteke Gis��le Semd�� Lazare Sika Tania Crucitti Virginie Etti��gne Traor�� Anne Buv�� Marie Laga 《PloS one》2012,7(3)
Objective
To assess condom use and prevalence of STIs and HIV among female sex workers (FSWs), as part of a comprehensive monitoring and evaluation plan of a nationwide sex worker prevention project in Côte d''Ivoire.Design and Methods
Cross sectional surveys were conducted among FSWs attending five project clinics in Abidjan and San Pedro (2007), and in Yamoussoukro and Gagnoa (2009). A standardized questionnaire was administered in a face-to-face interview, which included questions on socio-demographic characteristics, sexual behaviour and condom use. After the interview, the participants were asked to provide samples for STI and HIV testing.Results
A total of 1110 FSWs participated in the surveys. There were large differences in socio-demographic and behavioural characteristics between FSW coming for the first time as compared to FSW coming on a routine visit. The prevalence of N. gonorrhoeae or C.trachomatis was 9.1%, 11.8% among first vs. 6.9% routine attendees (p = 0.004). The overall HIV prevalence was 26.6%, it was lower among first time attendees (17.5% as compared to 33.9% for routine attendees, p<0.001). The HIV prevalence among first attendees was also lower than the proportion of HIV positive tests from routine testing and counselling services in the same clinics.Conclusions
The results show a relatively high STI and HIV prevalence among FSWs in different cities in Côte d''Ivoire. In the light of these results, prevention efforts should continue to focus on FSWs in the country. 相似文献4.
5.
Distinct Combinations of Borrelia burgdorferi Sensu Lato Genospecies Found in Individual Questing Ticks from Europe 总被引:1,自引:0,他引:1
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Klaus Kurtenbach Simona De Michelis Henna-Sisko Sewell Susanne Etti Stefanie M. Schfer Rosie Hails Margarida Collares-Pereira Margarida Santos-Reis Klra Haninov Milan Labuda Antra Bormane Michael Donaghy 《Applied microbiology》2001,67(10):4926-4929
The genetic diversity of Borrelia burgdorferi sensu lato was assessed in individual adult Ixodes ricinus ticks from Europe by direct PCR amplification of spirochetal DNA followed by genospecies-specific hybridization. Analysis of mixed infections in the ticks showed that B. garinii and B. valaisiana segregate from B. afzelii. This and previous findings suggest that host complement interacts with spirochetes in the tick, thereby playing an important role in the ecology of Lyme borreliosis. 相似文献
6.
Chuanlin Zheng Atiako Kwame Acheampong Zhaowan Shi Amichay Mugzech Tamar Halaly‐Basha Felix Shaya Yufei Sun Violeta Colova Assaf Mosquna Ron Ophir David W. Galbraith Etti Or 《Plant, cell & environment》2018,41(10):2490-2503
The molecular mechanism regulating dormancy release in grapevine buds is as yet unclear. It was formerly proposed that dormancy is maintained by abscisic acid (ABA)‐mediated repression of bud–meristem activity and that removal of this repression triggers dormancy release. It was also proposed that such removal of repression may be achieved via natural or artificial up‐regulation of VvA8H‐CYP707A4, which encodes ABA 8′‐hydroxylase, and is the most highly expressed paralog in grapevine buds. The current study further examines these assumptions, and its experiments reveal that (a) hypoxia and ethylene, stimuli of bud dormancy release, enhance expression of VvA8H‐CYP707A4 within grape buds, (b) the VvA8H‐CYP707A4 protein accumulates during the natural transition to the dormancy release stage, and (c) transgenic vines overexpressing VvA8H‐CYP707A4 exhibit increased ABA catabolism and significant enhancement of bud break in controlled and natural environments and longer basal summer laterals. The results suggest that VvA8H‐CYP707A4 functions as an ABA degrading enzyme, and are consistent with a model in which the VvA8H‐CYP707A4 level in the bud is up‐regulated by natural and artificial bud break stimuli, which leads to increased ABA degradation capacity, removal of endogenous ABA‐mediated repression, and enhanced regrowth. Interestingly, it also hints at sharing of regulatory steps between latent and lateral bud outgrowth. 相似文献
7.
Andrew F. Auld Kunomboa A. Ekra Ray W. Shiraishi Moise Z. Tuho Joseph S. Kouakou Fayama Mohamed Virginie Ettiègne-Traoré Jennifer Sabatier Joseph Essombo Georgette Adjorlolo-Johnson Richard Marlink Tedd V. Ellerbrock 《PloS one》2014,9(5)
Background
In Côte d''Ivoire during 2004–2007, numbers of ART enrollees increased from <5,000 to 36,943. Trends in nationally representative ART program outcomes have not yet been reported.Methodology/Principal Findings
We conducted a retrospective chart review to assess trends in patient characteristics and attrition [death or loss to follow-up (LTFU)] over time, among a nationally representative sample of 3,682 adults (≥15 years) initiating ART during 2004–2007 at 34 health facilities. Among ART enrollees during 2004–2007, median age was 36, the proportion female was 67%, the proportion HIV-2-infected or dually HIV-1&2 reactive was 5%, and median baseline CD4+ T-cell (CD4) count was 135 cells/µL. Comparing cohorts initiating ART in 2004 with cohorts initiating ART in 2007, median baseline weight declined from 55 kg to 52 kg (p = 0.008) and the proportion weighing <45 kg increased from 17% to 22% (p = 0.014). During 2004–2007, pharmacy-based estimates of the percentage of new ART enrollees ≥95% adherent to ART declined from 74% to 60% (p = 0.026), and twelve-month retention declined from 86% to 69%, due to increases in 12-month mortality from 2%–4% and LTFU from 12%–28%. In univariate analysis, year of ART initiation was associated with increasing rates of both LTFU and mortality. Controlling for baseline CD4, weight, adherence, and other risk factors, year of ART initiation was still strongly associated with LTFU but not mortality. In multivariate analysis, weight <45 kg and adherence <95% remained strong predictors of LTFU and mortality.Conclusions
During 2004–2007, increasing prevalence among ART enrollees of measured mortality risk factors, including weight <45 kg and ART adherence <95%, might explain increases in mortality over time. However, the association between later calendar year and increasing LTFU is not explained by risk factors evaluated in this analysis. Undocumented transfers, political instability, and patient dissatisfaction with crowded facilities might explain increasing LTFU. 相似文献8.
9.
On the mechanism of dormancy release in grapevine buds: a comparative study between hydrogen cyanamide and sodium azide 总被引:1,自引:0,他引:1
The effect of low doses (LD)—0.1 kJ m−2 d−1 and high doses (HD)—0.3 kJ m−2 d−1 of UV-C irradiation on free, conjugated and bound spermine, spermidine and putrescine in leaves of young pea plants after
7 and 14 days of consecutive treatment was studied. Free polyamine (PA) fractions increased mainly in LD treated plants, while
conjugated fractions decreased. Bound fractions accumulated mainly at the end of the experiment (after 14 days of UV-C irradiation).
The results are interpreted in relation to the possible role of endogenous bound PAs in the prevention of membrane damage
induced by UV-C irradiation. Stress markers (malondialdehyde and electrolyte leakage) increased after 7 days of UV-C treatment,
and reached control values by the end of the experiment (mainly after HD treatment). Malondialdehyde concentration correlated
negatively with UV-C—induced bound fraction and total PAs. The results support the conclusion that endogenous PAs lessen membrane
damage in young pea plants provoked by UV-C irradiation. 相似文献
10.