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1.
Regul Toxicol Pharmacol ; 134: 105226, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35817206

RESUMEN

An expert panel was convened to provide insight and guidance on per- and polyfluoroalkyl substances (PFAS) grouping for the purposes of protecting human health from drinking water exposures, and how risks to PFAS mixtures should be assessed. These questions were addressed through multiple rounds of blind, independent responses to charge questions, and review and comments on co-panelists responses. The experts agreed that the lack of consistent interpretations of human health risk for well-studied PFAS and the lack of information for the vast majority of PFAS present significant challenges for any mixtures risk assessment approach. Most experts agreed that "all PFAS" should not be grouped together, persistence alone is not sufficient for grouping PFAS for the purposes of assessing human health risk, and that the definition of appropriate subgroups can only be defined on a case-by-case manner. Most panelists agreed that it is inappropriate to assume equal toxicity/potency across the diverse class of PFAS. A tiered approach combining multiple lines of evidence was presented as a possible viable means for addressing PFAS that lack analytical and/or toxicological studies. Most PFAS risk assessments will need to employ assumptions that are more likely to overestimate risk than to underestimate risk, given the choice of assumptions regarding dose-response model, uncertainty factors, and exposure information.


Asunto(s)
Ácidos Alcanesulfónicos , Agua Potable , Fluorocarburos , Agua Potable/análisis , Fluorocarburos/análisis , Fluorocarburos/toxicidad , Humanos , Medición de Riesgo , Incertidumbre
2.
Environ Geochem Health ; 44(2): 527-535, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32740759

RESUMEN

Perchlorate (ClO4-) has been identified as a persistent environmental contaminant of concern. Perchlorate exposure is a potential health concern because it interferes with hormone production by thyroid gland. Food (fruits and vegetables) and drinking water are an important source of human exposure to perchlorate. However, little is known about the occurrence of perchlorate in Chile. The purpose of this study was to determine the occurrence of perchlorate in 145 samples (soil, drinking water, surface water, groundwater, fertilizers, fruits and vegetables) collected across Chile and estimate associated exposure to consumers. Our results show that perchlorate was detected in soil (median: 22.2 ng g-1), drinking water (median: 3.0 ng mL-1), fruits (median: 0.91 ng g-1 fresh weight [FW]), lettuce (median: 5.0 ng g-1 FW) and chard (median: 4.15 ng g-1 FW). Interestingly, perchlorate concentrations detected in drinking water from three regions (Serena, Copiapo and Illapel) exceeded the USEPA interim drinking water health advisory level of 15 ng mL-1. Median concentrations of perchlorate in non-nitrogenous fertilizers (3.1 mg kg-1) were higher than those in nitrogenous fertilizers (1.3 mg kg-1). Estimated daily intake (EDI) of perchlorate via drinking water was lower than the USEPA's reference dose (7000 ng kg-1 bw day-1). The EDI of perchlorate via vegetables (chard and lettuce) produced in northern Chile was three times higher than those produced in other regions. The results of this study provide information about perchlorate sources in Chile, which will be helpful in modifying current regulations.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Chile , Agua Potable/análisis , Fertilizantes/análisis , Frutas/química , Humanos , Percloratos , Suelo , Verduras , Contaminantes Químicos del Agua/análisis
3.
Hum Reprod ; 33(3): 426-433, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29340704

RESUMEN

STUDY QUESTION: Is iodine deficiency associated with decreased fecundability? SUMMARY ANSWER: Moderate to severe iodine deficiency is associated with a 46% decrease in fecundability. WHAT IS KNOWN ALREADY: Iodine deficiency is common in women of childbearing age but its effect on fecundability has not been investigated. STUDY DESIGN, SIZE, DURATION: The LIFE Study, a population-based prospective cohort study, enrolled 501 women who had discontinued contraception within 2 months to become pregnant between 2005 and 2009. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women reported on risk factors for infertility by interview then kept daily journals of relevant information. Women used fertility monitors to time intercourse relative to ovulation then used home digital pregnancy tests to identify pregnancies on the day of expected menstruation. Urine samples for iodine analysis were collected on enrollment. MAIN RESULTS AND THE ROLE OF CHANCE: Samples were in the deficiency range in 44.3% of participants. The group whose iodine-creatinine ratios were below 50 µg/g (moderate to severe deficiency) had a 46% reduction in fecundity (P = 0.028) compared with the group whose iodine-creatinine ratios were in the adequate range: adjusted fecundability odds ratio of becoming pregnant per cycle, 0.54 (95% confidence interval 0.31-0.94). LIMITATIONS, REASONS FOR CAUTION: Iodine concentrations vary within individuals over time, so the data must be interpreted by group as we have done; residual confounding is possible. WIDER IMPLICATIONS OF THE FINDINGS: Significant delays in becoming pregnant occur at iodine concentrations that are common in women in the USA and parts of Europe. Replicating these findings will be important to determine whether improving iodine status could be beneficial in improving fecundability. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, USA. Contracts N01-HD-3-3355; N01-HD-3-3356; N01-HD-3-3358 and HHSN275201100001l/HHSN27500007. None of the authors has any conflict of interest to declare.


Asunto(s)
Fertilidad/fisiología , Fertilización/fisiología , Infertilidad Femenina/orina , Yodo/orina , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Estudios Prospectivos , Factores de Riesgo , Tiempo para Quedar Embarazada , Adulto Joven
4.
J Nanosci Nanotechnol ; 18(6): 3960-3968, 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29442732

RESUMEN

A flower like cobalt oxide nanostructured thin film (Co2O3) on Nickel (Ni) plate as have been successfully developed via alcoholic Seed Layer assisted chemical bath Deposition (SLD) process. Through the controlled alkaline electrolytes, the flower and paddles like Co2O3 nanoarchitectures were formed. The prepared thin film was characterized by X-ray diffraction (XRD), scanning electron microscope with energy dispersive X-ray (SEM and EDX), Atomic Force Microscope (AFM), Raman spectroscopy techniques. Electron micrograph reveals the flower and paddles like nanostructured Co2O3 thin film deposited on Ni plates. The electrochemical characteristics were investigated using cyclic voltammetry (CV), charge-discharge and AC impedance spectroscopy in different aqueous electrolytes such as NaOH, KOH, and LiOH. The maximum specific capacitance of 856 Fg-1 was attained with 2 M KOH electrolyte with 2 mVs-1 of the Co2O3 thin film coated Ni plate at 80 °C using SLD method. The capacitance values obtained with various electrolytes are in the order of KOH > NaOH > LiOH. The results indicate that the present method is economical and the material is ecofriendly with enhanced capacitance property.

5.
J Membr Biol ; 250(6): 663-670, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29147828

RESUMEN

A mathematical model of a reaction-diffusion within an entrapped-cell photobioreactor packed with gel granules containing immobilized photosynthetic bacterial cells is discussed. A theoretical model is based on a system of coupled nonlinear reaction-diffusion equations. In this research work, we have developed an efficient wavelet-based spectral approach for solving the proposed model. Analytical expressions for the concentration of substrate and product are established for all values of reaction-diffusion parameters using second kind Chebyshev wavelet method. The analytical results were also compared with Homotopy perturbation method (HPM) and Adomian decomposition method (ADM). Satisfactory agreement with ADM and HPM solutions is observed. Moreover, the use of Chebyshev wavelets is found to be simple, reliable, efficient, and computationally attractive.


Asunto(s)
Modelos Teóricos , Algoritmos , Difusión , Fotobiorreactores
6.
J Orthop Sci ; 22(5): 840-845, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28554714

RESUMEN

BACKGROUND: Suprascapular nerve repair is a widely-prioritized procedure for shoulder reconstruction following brachial plexus injury. Although this procedure only reconstructs glenohumeral joint motion, the standard clinical assessment of shoulder function also includes the scapulothoracic joint contribution. The purpose of this preliminary study was to develop an objective method to accurately analyze shoulder abduction following suprascapular nerve repair in brachial plexus injury patients. METHODS: We introduced an objective method to accurately analyze independent shoulder abduction performed by supraspinatus muscle with the help of dynamic shoulder radiography. Antero-posterior radiographs of both shoulders in adduction and maximal active abduction were obtained. Five parameters were measured. They included global abduction, abduction in glenohumeral, scapulothoracic and clavicular joints along with lateral flexion of thoracic spine. Data were analyzed to distinguish glenohumeral joint contribution from that of scapulothoracic motion. The detailed biomechanics of glenohumeral motion were also analyzed in relation to scapulothoracic motion to separately define the contribution of each in global shoulder abduction. RESULTS: The test-retest, intra-examiner and inter-examiner reliabilities of the measurements were assessed. Intra-class correlation coefficient, Bland-Altman plots and repeatability coefficients showed excellent reliability for each parameter. The range of glenohumeral abduction showed high correlation to subtraction of the range of scapulothoracic from the range of global abduction. However, not all negative ranges of glenohumeral abduction meant non-recovery after nerve repair, because scapulothoracic motion contributed in parallel but not uniformly to global shoulder motion. CONCLUSION: The conventional measurement of shoulder global abduction with goniometer is not an appropriate method to analyze the results of suprascapular nerve repair in brachial plexus palsy patients. We recommend examination of glenohumeral and scapulothoracic motions separately with dynamic shoulder radiographic analysis. With scapulothoracic contribution to the global shoulder motion, the glenohumeral motion can be wrongly assessed.


Asunto(s)
Plexo Braquial/lesiones , Plexo Braquial/cirugía , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiología , Adolescente , Adulto , Artrografía , Fenómenos Biomecánicos , Humanos , Persona de Mediana Edad , Movimiento , Adulto Joven
7.
J Environ Biol ; 37(4): 565-71, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27498502

RESUMEN

An indigenous fungal strain was isolated from Indian Kolar Gold Field mine soil. The isolate was heterothallic, branched septate, deeply floccose, fast-growing, dull green with white background conidial columnar mycelium from Aspergillus section Fumigati. Diverse metabolic patterns of the isolate exhibit high metal, thermal resistance which grews well from 28 ± 1 degrees C to 37 degrees C and pH concentration was significant on the growth of isolate. Phylogenetic analysis of 16srRNA ß-Tubulin gene sequence established relationship among isolate and other taxa. Molecular identification and morphological features of fungal isolate were consistent with those of Neosartorya udagawae. Heterothallic N. udagawae FJ830683 strain was closely related to homothallic N. aureola EF661890. Fungal isolate extract synthesized narrow sized stable Gold nanoparticles (AuNPs).


Asunto(s)
Aspergillus/clasificación , Microbiología del Suelo , Aspergillus/genética , Aspergillus/aislamiento & purificación , Aspergillus/metabolismo , Secuencia de Bases , ADN de Hongos/genética , ADN de Hongos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Oro/metabolismo , India , Nanopartículas del Metal/análisis , Minería , Filogenia , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
8.
Ann Oncol ; 26(6): 1170-1174, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25701453

RESUMEN

BACKGROUND: Combination chemotherapy ABVD (doxorubicin, bleomycin, vinblastine and dacarabazine) cures ∼70% of patients with advanced Hodgkin's lymphoma (aHL, stages IIB, III and IV) while more toxic escalated BEACOPP (EB, combination of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisolone) increases cure rates to 85%. Patients with a positive interim positron emission tomography-computerized tomography (PET-CT) scan after two cycles (PET-2) of ABVD have very poor outcomes with continued ABVD. Intensifying therapy with EB in PET-2-positive patients ('response-adapted therapy') may improve cure rates, whereas the negative patients can continue ABVD alone. PATIENTS AND METHODS: Eligible patients with newly diagnosed aHL received two cycles of ABVD and underwent PET-2 (scored with semi-quantitative 5-point visual criteria, 'Deauville score'). PET-2-negative patients continued four additional cycles of ABVD, whereas PET-2-positive patients received four cycles of EB. A phase II sample size of 50 was estimated keeping the lower and higher proportion of rejection of the event-free survival (EFS) as 70% and 85%, respectively. RESULTS: Fifty patients [median age 28 (12-60) years; male : female: 39 : 11; stages: IIB-3 (6%), III-29 (58%) and IV-18 (36%); International Prognostic Score (IPS): 0-3: 34 (68%); 4-7: 16 (32%)] were enrolled; 49 underwent PET-2. Eight (16%) were PET-2-positive, whereas 41 (84%) were negative. Forty-seven were evaluable for EFS and all 50 for overall survival (OS). The 2-year EFS was 76% (95% CI: 68-83) and OS was 88% (95% CI: 82-94). PET-2 was strongly prognostic-2-year EFS, negative versus positive: 82% versus 50%; P = 0.013. CONCLUSION: PET-2 response-adapted strategy could not achieve EFS of 85% in aHL. However, escalated therapy improved outcomes in PET-2-positive patients compared with historical data. TRIAL REGISTRATION: CTRI/2012/06/002741 (http://www.ctri.nic.in) and NCT01304849 (http://www.clinicaltrials.gov).


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Enfermedad de Hodgkin/tratamiento farmacológico , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bleomicina/administración & dosificación , Bleomicina/efectos adversos , Niño , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Dacarbazina/administración & dosificación , Dacarbazina/efectos adversos , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Etopósido/administración & dosificación , Etopósido/efectos adversos , Femenino , Enfermedad de Hodgkin/diagnóstico por imagen , Humanos , India , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Imagen Multimodal , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Prednisona/administración & dosificación , Prednisona/efectos adversos , Procarbazina/administración & dosificación , Procarbazina/efectos adversos , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Vinblastina/administración & dosificación , Vinblastina/efectos adversos , Vincristina/administración & dosificación , Vincristina/efectos adversos , Adulto Joven
9.
Hum Reprod ; 30(11): 2645-57, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26350610

RESUMEN

STUDY QUESTION: Are urinary phthalate concentrations associated with altered semen quality parameters among males recruited from the general population? SUMMARY ANSWER: Urinary levels of metabolites of phthalate diesters are associated with lower total sperm counts, larger sperm head sizes, and higher percentages of morphologically abnormal sperm. WHAT IS KNOWN ALREADY: High dose experiments in rats implicate phthalates as anti-androgens. Studies involving infertile men seeking care suggest that phthalates influence measures of semen quality raising concern about the implications for men in the general population. STUDY DESIGN, SIZE, DURATION: This prospective cohort study comprised 501 male partners in couples discontinuing contraception to become pregnant, who were recruited from 16 US counties using population-based sampling frameworks from 2005 to 2009. PARTICIPANTS/MATERIALS, SETTING, METHODS: Urine and semen samples were obtained at baseline from 473 (94%) men, of whom 378 (80%) men provided a second sample the following month. Urine was analyzed for 14 monoester metabolites of phthalate diesters by high-performance liquid chromatography coupled to tandem mass spectrometry. Semen samples were analyzed for 34 quality parameters categorized as general, motility, morphology, sperm head and sperm chromatin structure. MAIN RESULTS AND THE ROLE OF CHANCE: Urinary mono-[2-(carboxymethyl) hexyl] phthalate (MCMHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-benzyl phthalate (MBzP), and mono-isononyl phthalate (MNP) were significantly associated with lower total sperm counts and concentrations, larger sperm head sizes, higher proportions of megalo head sperm morphology, and/or other morphological changes. Urinary mono-methyl phthalate (MMP) and mono-cyclohexyl phthalate (MCPP) were significantly associated with lower sperm motility, and urine mono-2-ethylhexyl phthalate (MEHP) was significantly associated with higher sperm motility. LIMITATIONS, REASONS FOR CAUTION: While adverse associations were observed, the implications of the findings for couple fecundity and fertility remain to be established. Cautious interpretation is needed in light of reliance on a single measurement of phthalate measure and no correction for multiple comparisons.


Asunto(s)
Ácidos Ftálicos/orina , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/anomalías , Adulto , Humanos , Masculino , Michigan , Persona de Mediana Edad , Estudios Prospectivos , Texas , Adulto Joven
10.
Phys Chem Chem Phys ; 17(46): 30983-7, 2015 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-26538114

RESUMEN

The electrochemical oxidation of toluene in N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyr](+)[Ntf2](-)) was investigated by using cyclic voltammetry and galvanostatic electrolysis in the presence of Co(II) at a Pt disc working electrode. Cyclic voltammetry (CV) investigations revealed that Co(II)-Co(III) oxidation is a diffusion controlled electron transfer process. The diffusion coefficient values of Co(II) were found to increase from 0.38 × 10(-7) to 1.9 × 10(-7) cm(2) s(-1) as the temperature was increased from 25 °C to 80 °C. The CV peak current for toluene electro-oxidation increased by nearly 7 fold in the presence of Co(II) demonstrating a good catalytic effect. Co(II) catalysed galvanostatic electrolysis of toluene at room temperature has shown that benzaldehyde was formed along with a small quantity of 3-methyl-1-hexanol.

11.
Ann Clin Microbiol Antimicrob ; 14: 18, 2015 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-25879935

RESUMEN

BACKGROUND: Novel chemical molecules recovered from endangered medicinal plants have wide applications and have the potential to cure different diseases caused by microorganisms. The aim of this study was to investigate In vitro antimicrobial, α-glucosidase inhibition and antioxidant activity of different solvent extracts of Epaltes divaricata L. METHODS: Antimicrobial activity of hexane, ethyl acetate and methanol extract of Epaltes divaricata was determined against bacteria and fungi using disc diffusion and microdilution method respectively. α-glucosidase inhibition, Total phenolic content (TPC), Reducing power activity, DPPH radical scavenging assay, hydroxyl radical scavenging activity, nitric oxide scavenging activity, superoxide scavenging activity and lipid peroxidation assay of plant extracts were performed according to standard protocol. Compound detection from the potential solvent extract was done through GC-MS analysis. RESULTS: Epaltes divaricata ethyl acetate extracts (EDEa) (1.25 mg/disc) showed significant inhibition for E. lentum (23 mm), E. aerogenes (18 mm), P. fluorescence (15 mm) and A. baumanii (15 mm). Minimum inhibitory concentration (MIC) of EDEa was found to be 31.25 µg/ml, 62.5 µg/ml and 62.5 µg/ml against A. flavus, A. niger and T. rubrum respectively. EDEa showed more α-glucosidase inhibition and antioxidant activity compared to hexane and methanol. EDEa showed 50% α-glucosidase inhibition at the concentration of 525.20 ± 2.37 µg/ml. The TPC of EDEa was 412.0 ± 2.21 mg of catechol equivalents/g extract. EDEa showed great scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC50 560 ± 2.02 µg/ml), hydroxyl (IC50 314.75 ± 2.56 µg/ml), nitric oxide (IC50 648.20 ± 2.09 µg/ml) and superoxide (IC50 361.14 ± 1.45 µg/ml) radicals, as well as high reducing power. EDEa also showed a more suppressive effect on lipid peroxidation. Using Antioxidant ß-carotene linoleate method, the scavenging values of EDEa was significantly lower than BHT. GC-MS analysis of EDEa showed maximum amount of 2-butenamide, N-(4-fluorophenyl)-3-methyl trans-cinnamyl tiglate silane and trichlorocyclohexyl silane (36.86%). CONCLUSION: The results obtained in this study clearly indicate that EDEa can be used as a natural antimicrobial, α-glucosidase inhibition and antioxidant agent.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Antioxidantes/farmacología , Asteraceae/química , Inhibidores de Glicósido Hidrolasas/farmacología , Extractos Vegetales/farmacología , Antibacterianos/química , Antifúngicos/química , Antioxidantes/química , Bacterias/efectos de los fármacos , Hongos/efectos de los fármacos , Inhibidores de Glicósido Hidrolasas/química , Extractos Vegetales/química , alfa-Glucosidasas/análisis
12.
Environ Res ; 137: 101-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25531814

RESUMEN

Bisphenol A, benzophenone-type UV filters, and phthalates are chemicals in high production and use including in a range of personal care products. Exposure of humans to these chemicals has been shown to affect endocrine function. Although short-lived, widespread exposure may lead to continual opportunity for these chemicals to elicit health effects in humans. The association of these chemicals with incident uterine leiomyoma, an estrogen sensitive disease, is not known. Urinary concentrations of bisphenol A (BPA), five benzophenone-type UV filters (2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2׳-dihydroxybenzophenone (2,2׳OH-4MeO-BP), 2,2׳4,4׳-tetrahydroxybenzophenone (2,2׳4,4׳OH-BP), and 4-hydroxybenzophenone (4OH-BP), and 14 phthalate monoesters were quantified in 495 women who later underwent laparoscopy/laparotomy at 14 clinical sites for the diagnosis of fibroids. Significantly higher geometric mean creatinine-corrected concentrations of BPA, 2,4OH-BP, and 2OH-4MeO-BP were observed in women with than without fibroids [BPA: 2.09µg/g vs. 1.46µg/g p=0.004; 2,4OH-BP:11.10µg/g vs. 6.71µg/g p=0.01; 2OH-4MeO-BP: 11.31µg/g vs. 6.10µg/g p=0.01]. Mono-methyl phthalate levels were significantly lower in women with than without fibroids (1.78µg/g vs. 2.40µg/g). However, none of the exposures were associated with a significant odds ratio even when adjusting for relevant covariates. There was a lack of an association between select nonpersistent chemicals and the odds of a fibroid diagnosis.


Asunto(s)
Exposición a Riesgos Ambientales , Contaminantes Ambientales/toxicidad , Leiomioma/epidemiología , Protectores Solares/toxicidad , Adolescente , Adulto , Compuestos de Bencidrilo/toxicidad , Compuestos de Bencidrilo/orina , Benzofenonas/toxicidad , Benzofenonas/orina , Cromatografía Líquida de Alta Presión , Monitoreo del Ambiente , Contaminantes Ambientales/orina , Femenino , Humanos , Leiomioma/inducido químicamente , Fenoles/toxicidad , Fenoles/orina , Ácidos Ftálicos/toxicidad , Ácidos Ftálicos/orina , Protectores Solares/metabolismo , Estados Unidos/epidemiología , Útero/efectos de los fármacos , Adulto Joven
13.
Med J Malaysia ; 70(3): 200-4, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26248785

RESUMEN

Clinical experience with extensively Drug Resistant tuberculosis (XDR-TB) has not been reported in Malaysia before. We describe the clinical characteristics, risk factors, progress and therapeutic regimen for a healthcare worker with XDR-TB, who had failed therapy for multidrug resistant TB (MDR TB) in our institution. This case illustrates the risk of TB among healthcare workers in high TB-burden settings, the importance of obtaining upfront culture and susceptibility results in all new TB cases, the problem of acquired drug resistance developing during MDR-TB treatment, the challenges associated with XDR-TB treatment regimens, the value of surgical resection in refractory cases, and the major quality of life impact this disease can have on young, economically productive individuals.

14.
Langmuir ; 30(32): 9780-8, 2014 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-25062385

RESUMEN

The entrapment of nanolipoprotein particles (NLPs) and liposomes in transparent, nanoporous silica gel derived from the precursor tetramethylorthosilicate was investigated. NLPs are discoidal patches of lipid bilayer that are belted by amphiphilic scaffold proteins and have an average thickness of 5 nm. The NLPs in this work had a diameter of roughly 15 nm and utilized membrane scaffold protein (MSP), a genetically altered variant of apolipoprotein A-I. Liposomes have previously been examined inside of silica sol-gels and have been shown to exhibit instability. This is attributed to their size (∼150 nm) and altered structure and constrained lipid dynamics upon entrapment within the nanometer-scale pores (5-50 nm) of the silica gel. By contrast, the dimensional match of NLPs with the intrinsic pore sizes of silica gel opens the possibility for their entrapment without disruption. Here we demonstrate that NLPs are more compatible with the nanometer-scale size of the porous environment by analysis of lipid phase behavior via fluorescence anisotropy and analysis of scaffold protein secondary structure via circular dichroism spectroscopy. Our results showed that the lipid phase behavior of NLPs entrapped inside of silica gel display closer resemblance to its solution behavior, more so than liposomes, and that the MSP in the NLPs maintain the high degree of α-helix secondary structure associated with functional protein-lipid interactions after entrapment. We also examined the effects of residual methanol on lipid phase behavior and the size of NLPs and found that it exerts different influences in solution and in silica gel; unlike in free solution, silica entrapment may be inhibiting NLP size increase and/or aggregation. These findings set precedence for a bioinorganic hybrid nanomaterial that could incorporate functional integral membrane proteins.


Asunto(s)
Nanopartículas/química , Gel de Sílice/química , Apolipoproteína A-I/química , Nanoestructuras/química , Polimetil Metacrilato/química
15.
Indian J Exp Biol ; 52(12): 1206-10, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25651615

RESUMEN

Chromium (Cr) contamination in soil is a growing concern in sustainable agriculture production and food safety. We performed pot experiment with chromium (30 mg/soil) to assess the accumulation potential of Zea mays and study the influence of four fertilizers, viz. Farm Yard Manure (FYM), NPK, Panchakavya (PK) and Vermicompost (VC) with respect to Cr accumulation. The oxidative stress and pigment (chlorophyll) levels were also examined. The results showed increased accumulation of chromium in both shoots and roots of Zea mays under FYM and NPK supply, and reduced with PK and VC. While the protein and pigment contents decreased in Cr treated plants, the fertilizers substantiated the loss to overcome the stress. Similarly, accumulation of Cr increased the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) indicating the enhanced damage control activity. However, these levels were relatively low in plants supplemented with fertilizers. Our results confirm that the maize can play an effective role in bioremediation of soils polluted with chromium, particularly in supplementation with fertilizers such as farm yard manure and NPK.


Asunto(s)
Cromo/metabolismo , Fertilizantes/clasificación , Suelo/química , Zea mays/metabolismo , Biodegradación Ambiental , Catalasa/metabolismo , Clorofila/metabolismo , Ecosistema , Estiércol , Estrés Oxidativo , Peroxidasa/metabolismo , Proteínas de Plantas/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Superóxido Dismutasa/metabolismo , Zea mays/crecimiento & desarrollo
17.
Mar Pollut Bull ; 208: 117055, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39366062

RESUMEN

After tin and mercury salts were added to estuarine microbial mats increasing amounts of methyltin and methylmercury, respectively, were formed over a 30 to 100 hour time period. Inhibition of the methylation by molybdate, a metabolic inhibitor of sulfate reduction, stimulation by pyruvate addition and lack of methylation by sterilized mats, were evidence that sulfate reducing bacteria within the mats were responsible for the tin and mercury methylation. Methyl mercury was formed from mercuric chloride and mercuric cysteine, but not from mercuric sulfide. We suggest that mercury bound to organic complexes in anoxic sediments is likely methylated by microbial mats. Since estuarine meiofauna and macrofauna fed on microbial mats, the methylmercury and methyltin formed by microbial mats could be an important avenue for the entrance of these compounds into the marine food web.


Asunto(s)
Mercurio , Estaño , Contaminantes Químicos del Agua , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Metilación , Estuarios , Sedimentos Geológicos/microbiología , Sedimentos Geológicos/química , Compuestos de Metilmercurio/metabolismo , Bacterias/metabolismo
18.
Sci Rep ; 14(1): 12429, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38816436

RESUMEN

Evapotranspiration (ETo) is an important component of the hydrological cycle and reliable estimates of ETo are essential for assessing crop water requirements and irrigation management. Direct measurement of evapotranspiration is both costly and involves complex and intricate procedures. Hence, empirical models are commonly utilized to estimate ETo using accessible meteorological data. Given that empirical methods operate on various assumptions, it is essential to assess their performance to pinpoint the most suitable methods for ETo calculation based on the availability of input data and the specific climatic conditions of a region. This study aims to evaluate different empirical methods of ETo in the tropical highland Udhagamandalam region of Tamil Nadu, India, utilizing sixty years of meteorological data from 1960-2020. In this study, 8 temperature-based and 10 radiation-based empirical models are evaluated against ETo estimates derived from pan evaporation observation and the FAO Penman-Monteith method (FAO-PM), respectively. Statistical error metrics indicate that both temperature and radiation-based models perform better for the Udhagamandalam region. However, radiation-based models performed better than the temperature based models. This is possibly due to the high humidity of the study region throughout the year. The results suggest that simple temperature and radiation-based models using minimum meteorological information are adequate to estimate ETo and thus find potential application in agricultural water practices, hydrological processes, and irrigation management.

19.
Int J Tuberc Lung Dis ; 27(10): 724-728, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37749834

RESUMEN

Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacillus Burkholderia pseudomallei. Mediastinal melioidosis has a range of clinical presentations, making it difficult to diagnose: we therefore reviewed the evidence on the clinical characteristics, radiological features and invasive diagnostic modalities or interventions. An electronic search was conducted on three databases (PubMed, SCOPUS, Google Scholar) from November to December 2022. The initial search yielded 120 results, of which 34 studies met the inclusion criteria, but only 31 full-texts were retrievable. Among these, 4 were cohort studies, 26 case reports or series and 1 a conference abstract. The four main themes covered were mediastinal melioidosis as a diagnostic dilemma, unexpected complications, invasive interventions or an accompanying thoracic feature. Radiological manifestations included matting, necrosis and abscess-like collection. Severe presentations of mediastinal melioidosis included superior vena cava obstruction, sinus tract formation and pericardial tamponade. Transbronchial needle aspiration was the most common invasive diagnostic modality. Further research is needed to understand the relationship between the thoracic features of melioidosis on patient prognosis, its relationship to melioidosis transmission and potential preventive measures.


Asunto(s)
Burkholderia pseudomallei , Melioidosis , Humanos , Melioidosis/diagnóstico por imagen , Melioidosis/complicaciones , Radiografía , Vena Cava Superior
20.
Afr J Thorac Crit Care Med ; 29(4): e1149, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38239775

RESUMEN

Background: Pleural fluid residue, or macroscopic tissue, circulating freely in the pleural fluid obtained through direct filtration, may carry diagnostic histopathological information. We aimed to determine the histopathological concordance of pleural fluid residue in diagnosing TPE and MPE, compared with conventional pleural biopsy. This was a prospective cohort study of consecutive inpatients with cytology-negative exudative effusion who underwent pleuroscopy and had their initial suctioned pleural fluid filtered for residue samples. Pleural fluid residue demonstrated malignant cells in four out of seven cases of pleural biopsy-confirmed malignancy. Pleural fluid residue has comparable cytomorphology but reduced cellularity compared with pleural biopsy. No tuberculous histological features were present in the pleural fluid residue samples. In this preliminary study pleural fluid residue provided histopathological information for malignant pleural effusion, but no incremental diagnostic information for tuberculous effusion. However larger and more definitive studies are required to clarify these findings, and to explore the utility and suitability of pleural fluid residue for mutational analysis. What the study adds: This study demonstrates the potential of pleural fluid residue as a non-invasive diagnostic method for confirming malignancy in cytology-negative exudative effusion. What are the implications of the findings: In resource-limited settings or patients contraindicated for pleural biopsy, pleural fluid residue may provide a viable diagnostic alternative; however, this observation needs further validation.

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