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1.
Light-scattering and surface tension measurements have been used to study the structure and thermodynamic properties of aqueous-salt solutions of pectins, with the degree of esterification (DE) varying from 5 to 100%. Pectin macromolecules were found in the form of aggregates with . The second virial coefficient of pectin was negative in these poor solvents and independent of the DE. Pectins exhibited surface activity at the air-water interface, the magnitude of this activity also being independent of the DE. 相似文献
2.
Determination of molecular weight of heparin by size exclusion chromatography with universal calibration 总被引:3,自引:0,他引:3
The molecular weight (MW) of heparin can be accurately determined by size exclusion chromatography using "universal calibration." A universal calibration curve was constructed for Superose 12 with standard pullulan samples and verified using characterized ficoll fractions. This calibration yielded the correct MW of heparin as determined by light scattering, when the ionic strength of the mobile phase was maintained over 1.0M. Sodium poly(styrenesulfonate) samples were not suitable standards because of adsorption at high salt concentration and repulsion from the packing material at low ionic strength. The extraordinarily high charge density of heparin leads to the need for high salt concentration to screen such repulsions. 相似文献
3.
Noelle A. Benzekri Jacques Sambou Binetou Diaw El Hadji Ibrahima Sall Fatima Sall Alassane Niang Selly Ba Ndèye Fatou Ngom Guèye Mouhamadou Ba?la Diallo Stephen E. Hawes Moussa Seydi Geoffrey S. Gottlieb 《PloS one》2015,10(11)
Background
Malnutrition and food insecurity are associated with increased mortality and poor clinical outcomes among people living with HIV/AIDS; however, the prevalence of malnutrition and food insecurity among people living with HIV/AIDS in Senegal, West Africa is unknown. The objective of this study was to determine the prevalence and severity of food insecurity and malnutrition among HIV-infected adults in Senegal, and to identify associations between food insecurity, malnutrition, and HIV outcomes.Methods
We conducted a cross-sectional study at outpatient clinics in Dakar and Ziguinchor, Senegal. Data were collected using participant interviews, anthropometry, the Household Food Insecurity Access Scale, the Individual Dietary Diversity Scale, and chart review.Results
One hundred and nine HIV-1 and/or HIV-2 participants were enrolled. The prevalence of food insecurity was 84.6% in Dakar and 89.5% in Ziguinchor. The prevalence of severe food insecurity was 59.6% in Dakar and 75.4% in Ziguinchor. The prevalence of malnutrition (BMI <18.5) was 19.2% in Dakar and 26.3% in Ziguinchor. Severe food insecurity was associated with missing clinic appointments (p = 0.01) and not taking antiretroviral therapy due to hunger (p = 0.02). Malnutrition was associated with lower CD4 cell counts (p = 0.01).Conclusions
Severe food insecurity and malnutrition are highly prevalent among HIV-infected adults in both Dakar and Ziguinchor, and are associated with poor HIV outcomes. Our findings warrant further studies to determine the root causes of malnutrition and food insecurity in Senegal, and the short- and long-term impacts of malnutrition and food insecurity on HIV care. Urgent interventions are needed to address the unacceptably high rates of malnutrition and food insecurity in this population. 相似文献4.
Software-based image analysis is a crucial step in the biological interpretation of two-dimensional gel electrophoresis experiments.
Recent significant advances in image processing methods combined with powerful computing hardware have enabled the routine
analysis of large experiments. We cover the process starting with the imaging of 2-D gels, quantitation of spots, creation
of expression profiles to statistical expression analysis followed by the presentation of results. Challenges for analysis
software as well as good practices are highlighted. We emphasize image warping and related methods that are able to overcome
the difficulties that are due to varying migration positions of spots between gels. Spot detection, quantitation, normalization,
and the creation of expression profiles are described in detail. The recent development of consensus spot patterns and complete
expression profiles enables one to take full advantage of statistical methods for expression analysis that are well established
for the analysis of DNA microarray experiments. We close with an overview of visualization and presentation methods (proteome
maps) and current challenges in the field.
An erratum to this article can be found at 相似文献
5.
Geoffrey S. Gottlieb Robert A. Smith Ndeye Mery Dia Badiane Selly Ba Stephen E. Hawes Macoumba Toure Alison K. Starling Fatou Traore Fatima Sall Stephen L. Cherne Joshua Stern Kim G. Wong Paul Lu Moon Kim Dana N. Raugi Airin Lam James I. Mullins Nancy B. Kiviat Papa Salif Sow for the UW-Dakar HIV- Study Group 《PloS one》2011,6(7)
Background
Antiretroviral therapy for HIV-2 infection is hampered by intrinsic resistance to many of the drugs used to treat HIV-1. Limited studies suggest that the integrase inhibitors (INIs) raltegravir and elvitegravir have potent activity against HIV-2 in culture and in infected patients. There is a paucity of data on genotypic variation in HIV-2 integrase that might confer intrinsic or transmitted INI resistance.Methods
We PCR amplified and analyzed 122 HIV-2 integrase consensus sequences from 39 HIV-2–infected, INI-naive adults in Senegal, West Africa. We assessed genetic variation and canonical mutations known to confer INI-resistance in HIV-1.Results
No amino acid-altering mutations were detected at sites known to be pivotal for INI resistance in HIV-1 (integrase positions 143, 148 and 155). Polymorphisms at several other HIV-1 INI resistance-associated sites were detected at positions 72, 95, 125, 154, 165, 201, 203, and 263 of the HIV-2 integrase protein.Conclusion
Emerging genotypic and phenotypic data suggest that HIV-2 is susceptible to the new class of HIV integrase inhibitors. We hypothesize that intrinsic HIV-2 integrase variation at “secondary” HIV-1 INI-resistance sites may affect the genetic barrier to HIV-2 INI resistance. Further studies will be needed to assess INI efficacy as part of combination antiretroviral therapy in HIV-2–infected patients. 相似文献6.
Farba Karam Fatou Mbow Helen Fletcher Cheikh S. Senghor Koura D. Coulibaly Andrea M. LeFevre Ndeye F. Ngom Gueye Tandakha Dieye Papa S. Sow Souleymane Mboup Christian Lienhardt 《PloS one》2008,3(1)
Background
Detection and treatment of latent TB infection (LTBI) in HIV infected individuals is strongly recommended to decrease morbidity and mortality in countries with high levels of HIV.Objective
To assess the validity of a newly developed in-house ELISPOT interferon-γ release assay (IGRA) for the detection of LTBI amongst HIV infected individuals, in comparison with the Tuberculin Skin Test (TST).Methodology/Principal Findings
ESAT6/CFP10 (EC) ELISPOT assays were performed, together with a TST, in 285 HIV infected individuals recruited in HIV clinics in Dakar, Senegal, who had no signs of active TB at time of enrolment. Thirty eight of the subjects (13.3%) failed to respond to PHA stimulation and were excluded from the analysis. In the 247 remaining patients, response to PHA did not vary according to CD4 cell count categories (p = 0.51). EC ELISPOT was positive in 125 (50.6%) subjects, while 53 (21.5%) had a positive TST. Concordance between EC ELISPOT and TST was observed in 151 patients (61.1%) (kappa = 0.23). The proportion of subjects with a positive response to the EC ELISPOT assay decreased with declining CD4 counts (p trend = 0.001), but were consistently higher than the proportion of TST responders. In multivariate analysis, the risk of being EC-ELISPOT positive in HIV infected individuals was associated with age, CD4 count and HIV-1 strain.Conclusion
Our study indicates that IGRAs using M. tuberculosis specific antigens are likely to retain their validity for the diagnosis of LTBI among HIV positive individuals, but may be impaired by T-cell anergy in severely immuno-suppressed individuals. 相似文献7.
Ankita Salvi Pratik Bankhele Jamal M. Jamil Madhura Kulkarni-Chitnis Ya Fatou Njie-Mbye Sunny E. Ohia Catherine A. Opere 《Neurochemical research》2016,41(5):1020-1028
In the present study, we investigated the effect of three different sources of hydrogen sulfide (H2S) on sympathetic neurotransmission from isolated superfused bovine iris-ciliary bodies. The three agents under consideration were: ACS67, a hybrid of latanoprost and a H2S-donating moiety; l-cysteine, a substrate for endogenous production of H2S and GYY 4137, a slow donor of H2S. We also examined the contribution of prostaglandins to the pharmacological actions of the H2S donors on release of [3H]-norepinephrine ([3H]NE) triggered by electrical field stimulation. ACS67, l-cysteine and GYY 4137 caused a concentration-dependent inhibition of electrically-evoked [3H]NE release from isolated bovine iris-ciliary bodies without affecting basal [3H]NE efflux. The cyclooxygenase inhibitor, flurbiprofen enhanced the inhibitory action of ACS67 and l-cysteine on stimulated [3H]NE release. Both aminooxyacetic acid, an inhibitor of cystathionine-β-synthase and glibenclamide, a KATP channel blocker reversed the inhibition of evoked NE release induced by the H2S donors. We conclude that H2S donors can inhibit sympathetic neurotransmission from isolated bovine iris-ciliary bodies, an effect partially dependent on the in situ production of H2S and prostanoids, and is mediated by an action on KATP channels. 相似文献
8.
Catherine A. Opere Emmanuel M. Monjok Kaustubh H. Kulkarni Ya Fatou Njie Sunny E. Ohia 《Neurochemical research》2009,34(11):1962-1968
Hydrogen sulfide (H2S), can produce pharmacological effects on neural and non-neural tissues from several mammalian species. The present study
investigates the pharmacological action of H2S, (using sodium hydrosulfide, NaHS, and/or sodium sulfide, Na2S as donors) on amino acid neurotransmission (using [3H] d-aspartate as a marker for glutamate) from isolated, superfused bovine and porcine retinae. Isolated neural retinae were incubated
in Krebs solution containing [3H] d-aspartate at 37°C. Release of [3H] d-aspartate was elicited by high potassium (K+ 50 mM) pulse. Both NaHS and Na2S donors caused an inhibition of K+-evoked [3H] d-aspartate release from isolated bovine retinae without affecting basal [3H] d-aspartate efflux yielding IC50 values of 0.006 and 6 μm, respectively. Furthermore, NaHS inhibited depolarization-evoked release of [3H] d-aspartate from isolated porcine retinae with an IC50 value of 8 μM. The inhibitory action of NaHS on [3H] d-aspartate release from porcine retinae was blocked by propargyglycine, a selective inhibitor of cystathionine γ-lyase (CSE).
Our results indicate that H2S donors can inhibit amino acid neurotransmission from both isolated bovine and porcine retinae, an effect that is dependent,
at least in part, on intramural biosynthesis of H2S. 相似文献
9.
10.
M F Berthéas D Germain B Lauras R Gaja G Blache J Fraisse C P Brizard 《Journal de génétique humaine》1988,36(1-2):63-67
Cytogenetic studies on a phenotypically normal fertile male revealed an unbalanced Y; 15 translocation. His wife referred for a prenatal diagnosis because of maternal age. The foetus was male and carried the same translocation. 相似文献