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101.
Ciaranello AL Perez F Maruva M Chu J Engelsmann B Keatinge J Walensky RP Mushavi A Mugwagwa R Dabis F Freedberg KA;CEPAC-International Investigators 《PloS one》2011,6(6):e20224
Background
The Zimbabwean national prevention of mother-to-child HIV transmission (PMTCT) program provided primarily single-dose nevirapine (sdNVP) from 2002–2009 and is currently replacing sdNVP with more effective antiretroviral (ARV) regimens.Methods
Published HIV and PMTCT models, with local trial and programmatic data, were used to simulate a cohort of HIV-infected, pregnant/breastfeeding women in Zimbabwe (mean age 24.0 years, mean CD4 451 cells/µL). We compared five PMTCT regimens at a fixed level of PMTCT medication uptake: 1) no antenatal ARVs (comparator); 2) sdNVP; 3) WHO 2010 guidelines using “Option A” (zidovudine during pregnancy/infant NVP during breastfeeding for women without advanced HIV disease; lifelong 3-drug antiretroviral therapy (ART) for women with advanced disease); 4) WHO “Option B” (ART during pregnancy/breastfeeding without advanced disease; lifelong ART with advanced disease); and 5) “Option B+:” lifelong ART for all pregnant/breastfeeding, HIV-infected women. Pediatric (4–6 week and 18-month infection risk, 2-year survival) and maternal (2- and 5-year survival, life expectancy from delivery) outcomes were projected.Results
Eighteen-month pediatric infection risks ranged from 25.8% (no antenatal ARVs) to 10.9% (Options B/B+). Although maternal short-term outcomes (2- and 5-year survival) varied only slightly by regimen, maternal life expectancy was reduced after receipt of sdNVP (13.8 years) or Option B (13.9 years) compared to no antenatal ARVs (14.0 years), Option A (14.0 years), or Option B+ (14.5 years).Conclusions
Replacement of sdNVP with currently recommended regimens for PMTCT (WHO Options A, B, or B+) is necessary to reduce infant HIV infection risk in Zimbabwe. The planned transition to Option A may also improve both pediatric and maternal outcomes. 相似文献102.
Protein kinase A-mediated serine 35 phosphorylation dissociates histone H1.4 from mitotic chromosome
Chu CS Hsu PH Lo PW Scheer E Tora L Tsai HJ Tsai MD Juan LJ 《The Journal of biological chemistry》2011,286(41):35843-35851
Global histone H1 phosphorylation correlates with cell cycle progression. However, the function of site-specific H1 variant phosphorylation remains unclear. Our mass spectrometry analysis revealed a novel N-terminal phosphorylation of the major H1 variant H1.4 at serine 35 (H1.4S35ph), which accumulates at mitosis immediately after H3 phosphorylation at serine 10. Protein kinase A (PKA) was found to be a kinase for H1.4S35. Importantly, Ser-35-phosphorylated H1.4 dissociates from mitotic chromatin. Moreover, H1.4S35A substitution mutant cannot efficiently rescue the mitotic defect following H1.4 depletion, and inhibition of PKA activity increases the mitotic chromatin compaction depending on H1.4. Our results not only indicate that PKA-mediated H1.4S35 phosphorylation dissociates H1.4 from mitotic chromatin but also suggest that this phosphorylation is necessary for specific mitotic functions. 相似文献
103.
Jinfeng Chu 《Inorganica chimica acta》2011,376(1):350-357
In this paper, two di-substituted triazine-based ligands, 6-chloro-N,N,N′N′-tetrakis-pyridin-2-ylmethyl-[1,3,5]triazine-2,4-diamine (L1), and 6-chloro-N,N′-bis-pyridin-2-ylmethyl-N,N′-bis-thiophen-2-ylmethyl-[1,3,5]triazine-2,4-diamine (L2), have been prepared. Reaction of CuCl2·2H2O and Cu(NO3)2·3H2O with L1 and L2 results in the formation of [Cu2Cl4(L1)]·3MeOH (compound 1), [Cu4(NO3)8(L1)2]·2.07CH2Cl2·0.93MeOH (compound 2), [Cu2Cl4(L2)2] (compound 3) and [Cu(NO3)2(L2)]·CH2Cl2 (compound 4), respectively, which have been fully characterized and determined by single-crystal X-ray crystallography, FT-IR, elemental analysis, thermogravimetric measurement and magnetic susceptibility. The dinuclear compound 1 shows strong π-π interactions between the neighboring pyridine rings. The nitrate-π (1,3,5-triazine ring) interaction with the distance of 2.755 Å in compound 2, is the closest contact reported so far. Compounds 3 and 4 are mononuclear copper(II) compounds, in which none of thiophene rings coordinates with copper(II) ion. In addition, the different orientations of two thiophene rings in compounds 3 and 4 lead to the π-π and CH2Cl2-π (thiophene ring) interactions in compound 4, but not in compound 3. 相似文献
104.
Li QY Su L Zu YG Zhang L Gao Y Wang CC Zhu QC Deng XQ 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(7-8):461-466
A new, simple, sensitive and specific reversed-phase high performance liquid chromatographic (HPLC) method using tandem mass spectrometry detection was initially developed and validated for the analysis of 10-(2-pyrazolyl-ethoxy)-(20S)-camptothecin (CPT13) in rat plasma. Pretreatment of the sample obtained from plasma involved a single protein precipitation step with using acetonitrile containing 0.1% formic acid. An aliquot of 20 μl was injected into a C-18 column. The chromatographic separation was achieved using the mobile phase consisting of acetonitrile:water (35:65) at a flow rate of 1.0 mL/min. The total run time for each sample was 10 min, and camptothecin (CPT, IS) and CPT13 were well separated with retention times of 5.1 min and 5.6 min, respectively. Detection was performed using a triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via an electrospray ionization (ESI) source. The calibration curve was linear (r2 = 0.9998) over the concentration range of 1-1000 ng/mL, with a LLOQ of 1 ng/mL for CPT13. The inter- and intra-day precision (%R.S.D.) were <2.58% and 6.28%, respectively, and the accuracies (%) were within the range of 97.34-110.67%. CPT13 in rat plasma was stable when stored at -20 °C or 4 °C for three freeze-thaw cycles, The method was employed for the first time during pharmacokinetic studies of CPT13 in rats following a single intravenous dose (0.1 mg/kg) and three different oral doses (50 mg/kg, 30 mg/kg, and 10 mg/kg). This fully validated method was successfully applied to a pharmacokinetic study of CPT13 in rats. 相似文献
105.
The purpose of this study was to test the morphology and haemodynamics of the renal artery in the rabbit as evaluated by conventional and contrast-enhanced ultrasonography (CEUS). The morphology and haemodynamics of the rabbit renal artery, including the diameter, which were measured using B-mode ultrasonography (US), colour Doppler US and CEUS, and systolic velocity, diastolic velocity and resistive index (RI) were measured using pulsed wave Doppler US. CEUS was used to measure the renal artery diameter: 0.21 ± 0.04 cm (right) and 0.21 ± 0.03 cm (left). Values of the main renal artery diameter obtained from CEUS significantly correlated with those of digital subtraction angiography. The blood flow velocity of the right main renal artery was 44.20 ± 8.71/18.92 ± 6.26 cm/s (systolic/diastolic) and 36.30 ± 6.89/17.64 ± 5.58 cm/s (systolic/diastolic), at its origin from the aorta and at the renal hilus, respectively. The blood flow velocity of the left main renal artery was 45.10 ± 8.49/19.00 ± 6.80 cm/s (systolic/diastolic) and 41.70 ± 10.25/19.55 ± 7.90 cm/s (systolic/diastolic), at its origin from the aorta and at the renal hilus, respectively. Conventional US provides a more feasible modality for measuring the morphology and haemodynamics of the rabbit renal artery. CEUS is a more accurate method for measuring diameter. This information on the morphology and haemodynamics of the rabbit renal artery might be helpful for researchers. 相似文献
106.
Steven Habbous Karen P. Chu Xin Qiu Anthony La Delfa Luke T.G. Harland Ehab Fadhel Angela Hui Bayardo Perez-Ordonez Ilan Weinreb Fei-Fei Liu John Waldron Brian O'Sullivan David Goldstein Wei Xu Shao Hui Huang Geoffrey Liu 《Cancer epidemiology》2013,37(6):820-829
Introduction Human papillomavirus (HPV) is a risk and prognostic factor for oropharyngeal cancer (OPC). Determining whether the incidence of HPV-associated OPC is rising informs health policy. Methods HPV status was ascribed using p16 immunohistochemistry in 683/1474 OPC patients identified from the Princess Margaret Hospital's Cancer Registry (from 2000 to 2010). Missing p16 data was estimated using multiple (n = 100) imputation (MI) and validated using an independent OPC cohort (n = 214). Non-OPC head and neck squamous cell carcinoma (HNSCC) (n = 3262) were also used for time-trend comparison. Regression was used to compare HNSCC subsets and time-trends. The c-index was used to measure the predictive ability of MI. Results The incidence of OPC rose from 23.3% of all HNSCC in 2000 to 31.2% in 2010 (p = 0.002). In the subset of OPC tested for p16, there was no change in p16 positivity over time (p = 0.9). However, p16 testing became more frequent over time (p < 0.0001), but was nonetheless biased, favouring never-smokers [OR 1.87 (95% CI 1.29–2.70)] and tumors of the tonsil [OR 2.30 (1.52–3.47)] or base-of-tongue [OR 1.72 (1.10–2.70)]. These same factors were also associated with p16-positivity [ORs 3.22 (1.27–8.16), 7.26 (3.50–15.1), 5.83 (2.70–12.7), respectively]. Following MI and normalization, the proportion of OPC that was p16-associated rose from 39.8% in 2000 to 65.0% in 2010, p = 0.002, fully explaining the rise in OPC in our patient population. Conclusion The rise in HNSCC referrals seen from 2000 to 2010 at our institution was driven primarily by p16-associated OPC. MI was necessary to derive reliable conclusions when cases with missing data are considerable. 相似文献
107.
It has been assumed that yeast external invertase is a dimer, with each subunit composed of a 60-kDa polypeptide chain. We now present evidence that at its optimal pH of 5.0, the predominant form of external invertase is an octamer with an average size of 8 X 10(5) Da. During ultracentrifugation the octamer dissociated to lower molecular weight forms, including a hexamer, tetramer, and dimer. All forms of the enzyme were shown to possess identical specific activities and to contain a similar carbohydrate to protein ratio. Although the monomer subunits (1 X 10(5) Da) were heterogenous in carbohydrate content, each subunit possessed nine oligosaccharide chains. When stained for protein and enzyme activity following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, only the oligomeric form of the enzyme appeared to be active. Thus, on partially inactivating invertase with 4 M guanidine hydrochloride both octamer and monomer were evident on the gels but only the former was active. Similarly, incubating at pH 2.5 in the presence of sodium dodecyl sulfate yielded only inactive monomer. The monomer, unlike the active oligomeric aggregate, was unable to hydrolyze sucrose after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Consistent with the in vitro studies, freshly prepared yeast lysate was shown to contain the octameric species of external invertase as the major active form of this enzyme. From these studies and others which employed deglycosylated invertase, it is concluded that the carbohydrate component of external invertase contributes not only to stabilizing enzyme activity, but also to maintaining its oligomeric structure. 相似文献
108.
109.
Mycorrhizal impacts on root trait plasticity of six maize varieties along a phosphorus supply gradient 总被引:4,自引:0,他引:4
Wang Xin-Xin Li Hongbo Chu Qun Feng Gu Kuyper Thomas W. Rengel Zed 《Plant and Soil》2020,457(1-2):71-81
Plant and Soil - Acidic soils with a pHwater below 5.5 occupy up to 40% of world’s arable land. Aluminum (Al) toxicity and magnesium (Mg) deficiency often coexist in acidic soils, limiting... 相似文献
110.
During postnatal development, UDP-Gal: GlcNAc(beta 1-4)-galactosyltransferase (4 beta-GT) and UDP-Gal:GalNAc(beta 1-3)-galactosyltransferase (3 beta-GT) activities were increased by 17- and 24-fold, respectively, in the rat small intestine. The injection of cortisone into suckling rats resulted in precocious induction of distal 4 beta- and 3 beta-GT activities by 2.7- and 1.8-fold, respectively. Injection of phorbol-12-myristate-13-acetate (PMA) resulted in precocious induction of distal 3 beta-GT by 2.7-fold. These results suggest that intestinal galactosyltransferase activities are under developmental regulation and can be modified by cortisone and PMA. 相似文献