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1.
Reprod Health ; 21(1): 123, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39180082

RESUMEN

Infertility refers to the inability to conceive after 12 months of regular, unprotected sexual intercourse. Psychosocial aspects of infertility research are predominant in developed countries. A scoping review of psychosocial aspects of infertility research conducted in Africa between 2000 and 2022 was conducted. Twelve databases and grey literature were searched for articles. Studies were included if they were published in English and included findings from patients diagnosed with primary or secondary infertility. A total of 2 372 articles were initially found and screening resulted in 116 articles being included in the scoping review. Most of the studies (81%) were conducted in Nigeria, Ghana and South Africa. Psychosocial aspects explored included quality of life, barriers to treatment, attitudes and stigma, and sociocultural and religious aspects of infertility, among others. The review maps published psychosocial research in the context of infertility in Africa and identifies gaps for future research.


Our aim was to review published studies on psychological and social research conducted among men and women who were seeking treatment for infertility in Africa between 2000 and 2022.We initially found 2 373 articles that seemed appropriate but after screening these articles only included 116 in this review.We found that in Africa, Nigeria, Ghana and South Africa produced the most studies on the psychological and social impact of infertility.Common areas of research include exploring patients quality of life, barriers to seeking fertility treatment, stigma and attitudes around infertility, social, cultural and religious issues relating to infertility.This review is therefore helpful in understanding where psychological and social research on infertility is being conducted, what it is focused on and what the gaps in research are.


Asunto(s)
Infertilidad , Calidad de Vida , Estigma Social , Humanos , Infertilidad/psicología , África , Calidad de Vida/psicología , Femenino , Masculino
2.
J Exp Biol ; 219(Pt 15): 2300-10, 2016 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-27489216

RESUMEN

The excretion of nitrogenous waste products in the form of ammonia (NH3) and ammonium (NH4 (+)) is a fundamental process in aquatic organisms. For mytilid bivalves, little is known about the mechanisms and sites of excretion. This study investigated the localization and the mechanisms of ammonia excretion in mytilid mussels. An Rh protein was found to be abundantly expressed in the apical cell membrane of the plicate organ, which was previously described as a solely respiratory organ. The Rh protein was also expressed in the gill, although at significantly lower concentrations, but was not detectable in mussel kidney. Furthermore, NH3/NH4 (+) was not enriched in the urine, suggesting that kidneys are not involved in active NH3/NH4 (+) excretion. Exposure to elevated seawater pH of 8.5 transiently reduced NH3/NH4 (+) excretion rates, but they returned to control values following 24 h acclimation. These mussels had increased abundance of V-type H(+)-ATPase in the apical membranes of plicate organ cells; however, NH3/NH4 (+) excretion rates were not affected by the V-type H(+)-ATPase specific inhibitor concanamycin A (100 nmol l(-1)). In contrast, inhibition of ciliary beating with dopamine and increased seawater viscosity significantly reduced NH3 excretion rates under control pH (8.0). These results suggest that NH3/NH4 (+) excretion in mytilid mussels takes place by passive NH3 diffusion across respiratory epithelia via the Rh protein, facilitated by the water current produced for filter feeding, which prevents accumulation of NH3 in the boundary layer. This mechanism would be energy efficient for sessile organisms, as they already generate water currents for filter feeding.


Asunto(s)
Amoníaco/metabolismo , Bivalvos/metabolismo , Cilios/metabolismo , Estructuras Animales/anatomía & histología , Estructuras Animales/enzimología , Animales , Bivalvos/enzimología , Epitelio/metabolismo , Branquias/metabolismo , Hemolinfa/metabolismo , Concentración de Iones de Hidrógeno , Transporte Iónico , Proteínas/metabolismo , Agua de Mar/química , ATPasas de Translocación de Protón Vacuolares/metabolismo
3.
Indoor Air ; 26(6): 892-902, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-26660492

RESUMEN

Relationships between measured moisture and qualitative dampness indicators (mold odor, visible mold, visible water damage, or peeling paint) were evaluated using data collected from California homes in a prospective birth cohort study when the infants were 6 or 12 months of age (737 home visits). For repeated visits, agreement between observation of the presence/absence of each qualitative indicator at both visits was high (71-87%, P < 0.0001). Among individual indicators, musty odor and visible mold were most strongly correlated with elevated moisture readings. Measured moisture differed significantly between repeated visits in opposite seasons (P < 0.0001), and dampness increased with the number of indicators in a home. Linear mixed-effect models showed that 10-unit increases in maximum measured moisture were associated with the presence of 0.5 additional dampness indicators (P < 0.001). Bedroom (BR) walls were damper than living room (LR) walls in the same homes (P < 0.0001), although both average and maximum readings were positively correlated across room type (r = 0.75 and 0.67, respectively, both P < 0.0001). Exterior walls were significantly damper than interior walls (P < 0.0001 in both LRs and BRs), but no differences were observed between maximum wall readings and measurements at either window corners or sites of suspected dampness.


Asunto(s)
Contaminación del Aire Interior/análisis , Asma/etiología , Monitoreo del Ambiente , Vivienda , Humedad/efectos adversos , California , Femenino , Humanos , Masculino , Estudios Prospectivos
4.
Indoor Air ; 24(3): 236-47, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24883433

RESUMEN

UNLABELLED: Dampness and visible mold in homes are associated with asthma development, but causal mechanisms remain unclear. The goal of this research was to explore associations among measured dampness, fungal exposure, and childhood asthma development without the bias of culture-based microbial analysis. In the low-income, Latino CHAMACOS birth cohort, house dust was collected at age 12 months, and asthma status was determined at age 7 years.The current analysis included 13 asthma cases and 28 controls. Next-generation DNA sequencing methods quantified fungal taxa and diversity. Lower fungal diversity (number of fungal operational taxonomic units) was significantly associated with increased risk of asthma development: unadjusted odds ratio(OR) 4.80 (95% confidence interval (CI) 1.04­22.1). Control for potential confounders strengthened this relationship. Decreased diversity within the genus Cryptococcus was significantly associated with increased asthma risk (OR 21.0, 95% CI 2.16­204). No fungal taxon (species, genus, class) was significantly positively associated with asthma development, and one was significantly negatively associated. Elevated moisture was associated with increased fungal diversity, and moisture/mold indicators were associated with four fungal taxa. Next-generation DNA sequencing provided comprehensive estimates of fungal identity and diversity, demonstrating significant associations between low fungal diversity and childhood asthma development in this community. PRACTICAL IMPLICATIONS: Early life exposure to low fungal diversity in house dust was associated with increased risk for later asthma developmen tin this low-income, immigrant community. No individual fungal taxon (species, genus, or class) was associated with asthma development, although exposure to low diversity within the genus Cryptococcus was associated with asthma development. Future asthma development studies should incorporate fungal diversity measurements, in addition to measuring individual fungal taxa. These results represent a step toward identifying the aspect(s) of indoor microbial populations that are associated with asthma development and suggest that understanding the factors that control diversity in the indoor environment may lead to public health recommendations for asthma prevention in the future.


Asunto(s)
Asma/etiología , Polvo/análisis , Hongos/inmunología , Variación Genética/inmunología , California , Distribución de Chi-Cuadrado , Niño , Estudios de Cohortes , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Polvo/inmunología , Femenino , Hongos/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Hispánicos o Latinos , Humanos , Masculino
5.
Sci Total Environ ; 854: 158551, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36075406

RESUMEN

Organophosphosphorus pesticides (OPs) are widely used as insecticides in agriculture. Human exposure to OPs has been linked to adverse effects including poorer child neurodevelopment, reduced birth weight, altered serum hormone levels, and reduced semen quality. We measured six OP dialkyl phosphate (DAP) metabolites [three dimethyl alkylphosphates (DMs) and three diethyl alkylphosphates (DEs)] in urine samples collected two times during pregnancy (~13 and ~26 weeks gestation) from 594 women participating in the CHAMACOS birth cohort study and resided in an agricultural community in the United States (U.S.) between 1999 and 2000. Previous studies have shown these women have higher OP exposures compared with the general U.S. population. We examined bivariate associations between prenatal DAP metabolite levels and exposure determinants such as age, season, years living in the US, housing characteristics, fruit and vegetable consumption, occupation and residential proximity to agricultural fields. Final multivariable models indicated that season of urine collection was significantly associated (p < 0.01) with specific gravity-adjusted DM, DE and total DAP metabolites; samples collected in fall and winter had higher concentrations than those collected in spring-summer. Specific gravity-adjusted levels of DM and total DAP metabolites were significantly higher in women who had resided in the U.S. for 5 years or less (p < 0.05). Levels of DM metabolites also increased with daily fruit and vegetable servings (p < 0.01), and levels of DE metabolites were higher in residences with poorer housekeeping quality (p < 0.01) and in mothers that worked in agriculture (p < 0.05). These findings suggest that there are multiple determinants of OP exposure in pregnant women.


Asunto(s)
Plaguicidas , Femenino , Humanos , Embarazo , Estudios de Cohortes , Exposición a Riesgos Ambientales/análisis , Organofosfatos/orina , Compuestos Organofosforados , Plaguicidas/orina , Fosfatos , Mujeres Embarazadas , Análisis de Semen
6.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37737699

RESUMEN

We describe an inertial rotation sensor with a 30-cm cylindrical proof-mass suspended from a pair of 14 µm thick BeCu flexures. The angle between the proof-mass and support structure is measured with a pair of homodyne interferometers, which achieve a noise level of ∼5prad/Hz. The sensor is entirely made of vacuum compatible materials, and the center of mass can be adjusted remotely.

7.
Rev Sci Instrum ; 94(5)2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37191465

RESUMEN

Control noise is a limiting factor in the low-frequency performance of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). In this paper, we model the effects of using new sensors called Homodyne Quadrature Interferometers (HoQIs) to control the suspension resonances. We show that if we were to use HoQIs, instead of the standard shadow sensors, we could suppress resonance peaks up to tenfold more while simultaneously reducing the noise injected by the damping system. Through a cascade of effects, this will reduce the resonant cross-coupling of the suspensions, allow for improved stability for feed-forward control, and result in improved sensitivity of the detectors in the 10-20 Hz band. This analysis shows that improved local sensors, such as HoQIs, should be used in current and future detectors to improve low-frequency performance.

8.
Allergy ; 67(9): 1149-56, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22775568

RESUMEN

RATIONALE: Churg-Strauss syndrome (CSS) and hypereosinophilic syndrome (HES) overlap considerably in clinical presentation. A reliable means of distinguishing between these groups of patients is needed, especially in the setting of glucocorticoid therapy. METHODS: A retrospective chart review of 276 adult subjects referred for evaluation of eosinophilia > 1500/µl was performed, and subjects with a documented secondary cause of eosinophilia or a PDGFR -positive myeloproliferative neoplasm were excluded. The remaining subjects were assessed for the presence of American College of Rheumatology (ACR) criteria. Laboratory and clinical parameters were compared between subjects with biopsy-proven vasculitis (CSS; n = 8), ≥4 ACR criteria (probable CSS; n = 21), HES with asthma and/or sinusitis without other CSS-defining criteria (HESwAS; n = 20), HES without asthma or sinusitis (HES; n = 18), and normal controls (n = 8). Serum biomarkers reported to be associated with CSS were measured using standard techniques. RESULTS: There were no differences between the subjects with definite or probable CSS or HES with respect to age, gender, or maintenance steroid dose. Serum CCL17, IL-8, and eotaxin levels were significantly increased in eosinophilic subjects as compared to normal controls, but were similar between the eosinophilic groups. Serum CCL17 correlated with eosinophil count (P < 0.0001, r = 0.73), but not with prednisone dose. CONCLUSIONS: In patients with a history of asthma and sinusitis, distinguishing between ANCA-negative CSS and PDGFR-negative HES is difficult because of significant overlap in clinical presentation and biomarker profiles.


Asunto(s)
Biomarcadores/sangre , Quimiocina CCL11/sangre , Quimiocina CCL17/sangre , Síndrome de Churg-Strauss/sangre , Síndrome Hipereosinofílico/sangre , Interleucina-8/sangre , Adulto , Anciano , Anciano de 80 o más Años , Síndrome de Churg-Strauss/metabolismo , Síndrome de Churg-Strauss/patología , Femenino , Humanos , Síndrome Hipereosinofílico/metabolismo , Síndrome Hipereosinofílico/patología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
9.
FASEB J ; 25(2): 515-25, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20952481

RESUMEN

For many years, mRNA abundance has been used as the surrogate measure of gene expression in biological systems. However, recent genome-scale analyses in both bacteria and eukaryotes have revealed that mRNA levels correlate with steady-state protein abundance for only 50-70% of genes, indicating that translation and post-translation processes also play important roles in determining gene expression. What is not yet clear is whether dynamic processes such as cell cycle progression, differentiation, or response to environmental changes change the relationship between mRNA and protein abundance. Here, we describe a systems approach to interrogate promastigote-to-amastigote differentiation in the obligatory intracellular parasitic protozoan Leishmania donovani. Our results indicate that regulation of mRNA levels plays a major role early in the differentiation process, while translation and post-translational regulation are more important in the latter part. In addition, it appears that the differentiation signal causes a transient global increase in the rate of protein synthesis, which is subsequently down-regulated by phosphorylation of α-subunit of translation initiation factor 2. Thus, Leishmania dynamically changes the relationship between mRNA and protein abundance as it adapts to new environmental circumstances. It is likely that similar mechanisms play a more important role than previously recognized in regulation of gene expression in other organisms.


Asunto(s)
Regulación de la Expresión Génica/fisiología , Leishmania donovani/genética , Leishmania donovani/metabolismo , Animales , Diferenciación Celular , Análisis de Secuencia por Matrices de Oligonucleótidos , Pliegue de Proteína , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Protozoario/genética , ARN Protozoario/metabolismo , Factores de Tiempo
10.
Cochrane Database Syst Rev ; (2): CD007288, 2012 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-22336830

RESUMEN

BACKGROUND: Bell's palsy is an idiopathic, acute unilateral facial weakness that evolves rapidly and is maximal within two days. Moderate ear discomfort, sensitivity to sound and reduced tearing may occur. OBJECTIVES: To assess the effects of hyperbaric oxygen therapy on recovery of facial function in adults with moderate to severe Bell's palsy. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (January 2012), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to January 2012), EMBASE (January 1980 to January 2012), CINAHL (1937 to January 2012), AMED (1985 to January 2012), LILACS (January 1982 to January 2012). In addition we made a systematic search for relevant controlled trials in specific hyperbaric literature sources. SELECTION CRITERIA: Randomised controlled trials or quasi-randomised controlled trials of adults (over 16 years of age) undergoing hyperbaric oxygen therapy for moderate to severe Bell's palsy. We considered studies to be of sufficient quality for inclusion in the review only if there was blinding in the assessment of the facial palsy grade. We planned to include studies of HBOT used as adjuvant therapy, or in addition to routine medical therapy (including corticosteroids or antivirals, or both). Both treatment and control groups were to receive the same baseline therapy. HBOT had to be delivered at concentrations greater than or equal to 1.2 ATA in a hyperbaric oxygen chamber as a series of dives of 30 to 120 minutes. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed eligibility and study quality and extracted data. We contacted study authors for additional information. MAIN RESULTS: Our searches found no randomised controlled trials or quasi-randomised controlled trials that met the eligibility criteria for this review.There is very low quality evidence from one randomised trial involving 79 participants with acute Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation and thus did not meet pre-defined eligibility criteria. The trial compared 42 people who received hyperbaric oxygen therapy (2.8 atmospheres for 60 minutes twice daily, five days per week until the facial palsy resolved; maximum 30 'dives') and placebo tablets with 37 people who received placebo hyperbaric oxygen therapy (achieving only a normal partial pressure of oxygen) and prednisone (40 mg twice daily, reducing over eight days). Facial function recovered in more participants treated with hyperbaric oxygen therapy than with prednisone (hyperbaric oxygen therapy, 40/42 (95%); prednisone, 28/37 (76%); risk ratio 1.26, 95% CI 1.04 to 1.53). There were no reported major complications and all participants completed the trial. AUTHORS' CONCLUSIONS: Very low quality evidence from one trial suggests that hyperbaric oxygen therapy may be an effective treatment for moderate to severe Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation. Further randomised controlled trials are needed.


Asunto(s)
Parálisis de Bell/terapia , Oxigenoterapia Hiperbárica/métodos , Adulto , Humanos
11.
S Afr Med J ; 111(10): 938-941, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-34949285

RESUMEN

Hookah pipe (HP) smoking is perceived as a harmless activity, enjoyed by young adults and high school-going children. Awareness of the health impact of recreational habits, and their intersection with new social norms in the COVID-era, requires critical review. We describe a case series of young HP smokers presenting with secondary polycythaemia with significant clinical sequelae necessitating extensive work-up. HP smoking may lead to acute and chronic carbon monoxide intoxication, with resultant secondary polycythaemia and complications including provoked thrombosis.


Asunto(s)
Intoxicación por Monóxido de Carbono/etiología , Policitemia/etiología , Tromboembolia/etiología , Fumar en Pipa de Agua/efectos adversos , Adulto , Humanos , Masculino , Persona de Mediana Edad , Sudáfrica
12.
J Exp Med ; 135(3): 458-75, 1972 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-4550767

RESUMEN

Rabbit antibodies were prepared against purified mouse macrophages, erythrocytes, and liver lysosomes. In the presence of complement each of these reagents was capable of lysing mouse erythrocytes and macrophages. In the absence of complement, all antisera agglutinated mouse erythrocytes and at high concentration produced a cytotoxic effect on macrophages. At IgG concentrations of 100 microg/ml, no morphological evidence of cytotoxicity was evident. These data suggest the presence of common antigens on the erythrocyte and macrophage plasma membrane. Anti-macrophage, anti-erythrocyte, and anti-lysosomal gamma-globulins and IgG, employed at subtoxic concentrations, all inhibited the attachment and ingestion of opsonized erythrocytes and mycoplasma. This occurred without significant reduction in the phagocytosis of polystyrene particles, formalinized erythrocytes, and yeast cell walls. Each of the anti-membrane IgG antibodies was capable of blocking the Fc receptor on the macrophage plasma membrane. Attachment to the macrophage membrane occurred by means of the Fab region. However, a role for the Fc portion of the molecule was suggested since pepsin-digested IgG was unable to block the receptor. Each of the IgG antibodies produced a partial blockade of the complement receptor and reduced the ingestion of EAC1,4,2,3 by approximately 50%.


Asunto(s)
Anticuerpos , Reacciones Antígeno-Anticuerpo , Membrana Celular/inmunología , Inmunidad Celular , Macrófagos/inmunología , Sulfato de Amonio , Animales , Precipitación Química , Cromatografía en Gel , Eritrocitos/inmunología , Formaldehído , Pruebas de Hemaglutinación , Inmunoglobulina G , Inmunoglobulinas/aislamiento & purificación , Técnicas In Vitro , Hígado/citología , Hígado/inmunología , Lisosomas/inmunología , Macrófagos/citología , Ratones , Microscopía de Contraste de Fase , Mycoplasma/inmunología , Fagocitosis , Conejos
13.
Audiol Neurootol ; 15(5): 291-302, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20150727

RESUMEN

OBJECTIVES: To assess the importance of 2 variables, transducer tip diameter and resection of the round window (RW) niche, affecting the optimization of the mechanical stimulation of the RW membrane with an active middle ear implant (AMEI). MATERIALS AND METHODS: Ten temporal bones were prepared with combined atticotomy and facial recess approach to expose the RW. An AMEI stimulated the RW with 2 ball tip diameters (0.5 and 1.0 mm) before and after the resection of the bony rim of the RW niche. The RW drive performance, assessed by stapes velocities using laser Doppler velocimetry, was analyzed in 3 frequency ranges: low (0.25-1 kHz), medium (1-3 kHz) and high (3-8 kHz). RESULTS: Driving the RW produced mean peak stapes velocities (H(EV)) of 0.305 and 0.255 mm/s/V at 3.03 kHz, respectively, for the 1- and 0.5-mm tips, with the RW niche intact. Niche drilling increased the H(EV) to 0.73 and 0.832 mm/s/V for the 1- and 0.5-mm tips, respectively. The tip diameter produced no difference in output at low and medium frequencies; however, the 0.5-mm tip was 5 and 6 dB better than the 1-mm tip at high frequencies before and after niche drilling, respectively. Drilling the niche significantly improved the output by 4 dB at high frequencies for the 1-mm tip, and by 6 and 10 dB in the medium- and high-frequency ranges for the 0.5-mm tip. CONCLUSION: The AMEI was able to successfully drive the RW membrane in cadaveric temporal bones using a classical facial recess approach. Stimulation of the RW membrane with an AMEI without drilling the niche is sufficient for successful hearing outputs. However, the resection of the bony rim of the RW niche significantly improved the RW stimulation at medium and higher frequencies. Drilling the niche enhances the exposure of the RW membrane and facilitates positioning the implant tip.


Asunto(s)
Ventana Redonda/cirugía , Estribo/fisiología , Hueso Temporal/cirugía , Humanos , Prótesis Osicular , Procedimientos Quirúrgicos Otológicos , Ventana Redonda/fisiología
14.
Thorax ; 64(4): 353-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19240083

RESUMEN

BACKGROUND: Many studies have found that the risk of childhood asthma varies by month of birth, but few have examined ambient aeroallergens as an explanatory factor. A study was undertaken to examine whether birth during seasons of elevated ambient fungal spore or pollen concentrations is associated with risk of early wheezing or blood levels of Th1 and Th2 type cells at 24 months of age. METHODS: 514 children were enrolled before birth and followed to 24 months of age. Early wheezing was determined from medical records, and Th1 and Th2 type cells were measured in peripheral blood using flow cytometry. Ambient aeroallergen concentrations were measured throughout the study period and discrete seasons of high spore and pollen concentrations were defined. RESULTS: A seasonal pattern was observed, with birth in autumn to winter (the spore season) associated with increased odds of early wheezing (adjusted odds ratio 3.1; 95% confidence interval 1.3 to 7.4). Increasing mean daily concentrations of basidiospores and ascospores in the first 3 months of life were associated with increased odds of wheeze, as were increasing mean daily concentrations of total and specific pollen types. Levels of Th1 cells at age 24 months were positively associated with mean spore concentrations and negatively associated with mean pollen concentrations in the first 3 months of life. CONCLUSIONS: Children with higher exposure to spores and pollen in the first 3 months of life are at increased risk of early wheezing. This association is independent of other seasonal factors including ambient levels of particulate matter of aerodynamic diameter

Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Alérgenos/efectos adversos , Exposición a Riesgos Ambientales/efectos adversos , Hongos , Polen/efectos adversos , Ruidos Respiratorios/etiología , Contaminantes Atmosféricos/análisis , California , Citocinas/metabolismo , Exposición a Riesgos Ambientales/análisis , Femenino , Humanos , Lactante , Recién Nacido , Masculino , México/etnología , Material Particulado/efectos adversos , Material Particulado/análisis , Factores de Riesgo , Estaciones del Año , Esporas Fúngicas , Linfocitos T Colaboradores-Inductores/fisiología
15.
Science ; 257(5074): 1245-7, 1992 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-1387730

RESUMEN

Tentoxin is a naturally occurring phytotoxic peptide that causes seedling chlorosis and arrests growth in sensitive plants and algae. In vitro, it inhibits activity of the beta subunit of the plastid proton-adenosine triphosphatase (ATPase) from sensitive species. Plastid atpB genes from six closely related, tentoxin-sensitive or -resistant Nicotiana species differ at codon 83, according to their response to the toxin: glutamate correlated with resistance and aspartate correlated with sensitivity. The genetic relevance of this site was confirmed in Chlamydomonas reinhardtii by chloroplast transformation. The alga, normally tentoxin-resistant, was rendered tentoxin-sensitive by mutagenesis of its plastid atpB gene at codon 83. Codon 83 may represent a critical site on the beta subunit that does not compete with nucleotide binding or other catalytic activities.


Asunto(s)
Cloroplastos/efectos de los fármacos , Micotoxinas/farmacología , Péptidos Cíclicos/farmacología , ATPasas de Translocación de Protón/fisiología , Adenosina Trifosfato/biosíntesis , Secuencia de Aminoácidos , Animales , División Celular/efectos de los fármacos , Chlamydomonas , Relación Dosis-Respuesta a Droga , Resistencia a Medicamentos/genética , Hidrólisis/efectos de los fármacos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Plantas Tóxicas , ATPasas de Translocación de Protón/genética , Rhodospirillum rubrum , Homología de Secuencia de Ácido Nucleico , Nicotiana , Transformación Genética
18.
Mol Biochem Parasitol ; 152(1): 53-65, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17204342

RESUMEN

Leishmania donovani is an intracellular protozoan parasite that causes kala-azar in humans. During infection the extracellular insect forms (promastigotes) undergo rapid differentiation to intracellular amastigotes that proliferates in phagolysosomes of mammalian macrophages. We used microarray-based expression profiling to investigate the time-course of changes in RNA abundance during promastigote-to-amastigote differentiation in a host-free system that mimics this process. These studies revealed that several hundred genes underwent an ordered progression of transient or permanent up- and down-regulation during differentiation. Genes that were permanently up-regulated in amastigotes were enriched for transporters and surface proteins, but under-represented in genes involved in protein and other metabolism. Most of these changes occurred late in the differentiation process, when morphological differentiation was essentially complete. Down-regulated genes were over-represented in those involved in cell motility, growth and/or maintenance, and these changes generally occurred earlier in the process. Genes that were transiently up- or down-regulated during differentiation included those encoding heat shock proteins, ubiquitin hydrolases, RNA binding proteins, protein kinases, a protein phosphatase, and a histone deacetylase. These results suggest that changes in mRNA abundance may be important in signal transduction, as well as protein and mRNA turnover, during differentiation. In addition to these mRNA changes, other transcripts including one or more rRNAs and snoRNAs, and non-coding RNAs from several telomeres, also showed substantial changes in abundance during the differentiation process. This paper provides the first genome-scale quantitative analysis of gene expression during the transition from promastigotes to amastigotes and demonstrates the utility of the host-free differentiation system.


Asunto(s)
Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Leishmania donovani/genética , Animales , Northern Blotting , ADN Protozoario/química , ADN Protozoario/genética , Leishmania donovani/crecimiento & desarrollo , Leishmania donovani/metabolismo , Datos de Secuencia Molecular , Morfogénesis/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas Protozoarias/biosíntesis , ARN Mensajero/biosíntesis , ARN Protozoario/biosíntesis , Análisis de Secuencia de ADN , Factores de Tiempo
19.
J Am Geriatr Soc ; 65(5): 1061-1066, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28182265

RESUMEN

OBJECTIVE: To examine the association between long-term metformin therapy and serum vitamin B12 monitoring. DESIGN: Retrospective cohort study. SETTING: A single Veterans Affairs Medical Center (VAMC), 2002-2012. PARTICIPANTS: Veterans 50 years or older with either type 2 diabetes and long-term metformin therapy (n = 3,687) or without diabetes and no prescription for metformin (n = 13,258). MEASUREMENTS: We determined diabetes status from outpatient visits, and defined long-term metformin therapy as a prescription ≥500 mg/d for at least six consecutive months. We estimated the proportion of participants who received a serum B12 test and used multivariable logistic regression, stratified by age, to evaluate the association between metformin use and serum B12 testing. RESULTS: Only 37% of older adults with diabetes receiving metformin were tested for vitamin B12 status after long-term metformin prescription. The mean B12 concentration was significantly lower in the metformin-exposed group (439.2 pg/dL) compared to those without diabetes (522.4 pg/dL) (P = .0015). About 7% of persons with diabetes receiving metformin were vitamin B12 deficient (<170 pg/dL) compared to 3% of persons without diabetes or metformin use (P = .0001). Depending on their age, metformin users were two to three times more likely not to receive vitamin B12 testing compared to those without metformin exposure, after adjusting for sex, race and ethnicity, body mass index, and number of years treated at the VAMC. CONCLUSION: Long-term metformin therapy is significantly associated with lower serum vitamin B12 concentration, yet those at risk are often not monitored for B12 deficiency. Because metformin is first line therapy for type 2 diabetes, clinical decision support should be considered to promote serum B12 monitoring among long-term metformin users for timely identification of the potential need for B12 replacement.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Metformina/uso terapéutico , Veteranos/estadística & datos numéricos , Deficiencia de Vitamina B 12/inducido químicamente , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Hospitales de Veteranos , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Deficiencia de Vitamina B 12/sangre
20.
J Dev Orig Health Dis ; 8(2): 196-205, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28031075

RESUMEN

Oxidative stress has been linked to many obesity-related conditions among children including cardiovascular disease, diabetes mellitus and hypertension. Exposure to environmental chemicals such as phthalates, ubiquitously found in humans, may also generate reactive oxygen species and subsequent oxidative stress. We examined longitudinal changes of 8-isoprostane urinary concentrations, a validated biomarker of oxidative stress, and associations with maternal prenatal urinary concentrations of phthalate metabolites for 258 children at 5, 9 and 14 years of age participating in a birth cohort residing in an agricultural area in California. Phthalates are endocrine disruptors, and in utero exposure has been also linked to altered lipid metabolism, as well as adverse birth and neurodevelopmental outcomes. We found that median creatinine-corrected 8-isoprostane concentrations remained constant across all age groups and did not differ by sex. Total cholesterol, systolic and diastolic blood pressure were positively associated with 8-isoprostane in 14-year-old children. No associations were observed between 8-isoprostane and body mass index (BMI), BMI Z-score or waist circumference at any age. Concentrations of three metabolites of high molecular weight phthalates measured at 13 weeks of gestation (monobenzyl, monocarboxyoctyl and monocarboxynonyl phthalates) were negatively associated with 8-isoprostane concentrations among 9-year olds. However, at 14 years of age, isoprostane concentrations were positively associated with two other metabolites (mono(2-ethylhexyl) and mono(2-ethyl-5-carboxypentyl) phthalates) measured in early pregnancy. Longitudinal data on 8-isoprostane in this pediatric population with a high prevalence of obesity provides new insight on certain potential cardiometabolic risks of prenatal exposure to phthalates.


Asunto(s)
Dinoprost/análogos & derivados , Exposición Materna/efectos adversos , Americanos Mexicanos/estadística & datos numéricos , Obesidad/epidemiología , Ácidos Ftálicos/efectos adversos , Efectos Tardíos de la Exposición Prenatal/epidemiología , Adolescente , Adulto , Niño , Preescolar , Dinoprost/efectos adversos , Femenino , Humanos , Estudios Longitudinales , Masculino , Obesidad/inducido químicamente , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Prevalencia , Estados Unidos/epidemiología , Vasoconstrictores/efectos adversos
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