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1.
bioRxiv ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-39005323

RESUMEN

RNA virus infections are composed of a diverse mix of viral genomes that arise from low fidelity in replication within cells. The interactions between "defective" and full-length viral genomes have been shown to shape pathogenesis, leading to intense research into employing these to develop novel antivirals. In particular, Influenza A defective viral genomes (DVGs) have been associated with milder clinical outcomes. Yet, the full potential of DVGs as broad-spectrum antivirals remains untapped due to the unknown mechanisms of their de novo production. Much of the research into the factors affecting defective viral genome production has focused on the virus, while the role of the host has been neglected. We recently showed that altering host cell metabolism away from pro-growth pathways using alpelisib increased the production of Influenza A defective viral genomes. To uncover other drugs that could induce infections to create more DVGs, we subjected active influenza infections of the two circulating human subtypes (A/H1N1 & A/H3N2) to a screen of metabolites, metabolic signaling molecules, and cyanobacteria-derived biologics, after which we quantified the defective viral genomes (specifically deletion-containing viral genomes, DelVGs) and total viral genomes using third generation long-read sequencing. Here we show that metabolites and signaling molecules of host cell central carbon metabolism can significantly alter DelVG production early in Influenza A infection. Adenosine, emerged as a potent inducer of defective viral genomes, significantly amplifying DelVG production across both subtypes. Insulin had similar effects, albeit subtype-specific, predominantly enhancing polymerase segment DVGs in TX12 infections. Tricarboxylic Acid (TCA) cycle inhibitors 4-octyl itaconate and UK5099, along with the purine analog favipiravir, increased total viral genome production across subtypes. Cyanobacterial extracts primarily affected DVG and total viral genome production in TX12, with a specific, almost complete shutdown of influenza antigenic segments. These results underscore the influence of host metabolic pathways on DVG production and suggest new avenues for antiviral intervention, including PI3K-AKT and Ras-MAPK signaling pathways, TCA cycle metabolism, purine-pyrimidine metabolism, polymerase inhibition, and cyanotherapeutic approaches. More broadly, our findings suggest that the social interactions observed between defective and full-length viral genomes, depend not only on the viral actors, but can be altered by the stage provided by the host. Our study advances our fundamental understanding of DVG production mechanisms and highlights the potential of targeting host metabolism to develop broad-spectrum influenza therapeutics.

2.
Milbank Q ; 101(S1): 119-152, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37096601

RESUMEN

Policy Points There is growing attention to the role of immigration and immigrant policies in shaping the health and well-being of immigrants of color. The early 21st century in the United States has seen several important achievements in inclusionary policies, practices, and ideologies toward immigrants, largely at subnational levels (e.g., states, counties, cities/towns). National policies or practices that are inclusionary toward immigrants are often at the discretion of the political parties in power. Early in the 21st century, the United States has implemented several exclusionary immigration and immigrant policies, contributing to record deportations and detentions and worsening inequities in the social drivers of health.


Asunto(s)
Emigrantes e Inmigrantes , Equidad en Salud , Estados Unidos , Humanos , Emigración e Inmigración , Política Pública , Política de Salud
3.
J Ocul Pharmacol Ther ; 39(1): 80-85, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36520599

RESUMEN

Purpose: Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries with little in the way of treatment that prevents progression to end-stage disease. Kaempferol (KF) is a plant-derived dietary flavonoid that has demonstrated as a strong antioxidant showing neuroprotection in stroke models. We hypothesize that KF has protective effects against retinal degeneration and may serve as a therapeutic agent against AMD. Methods: BALB/c albino mice were assigned to 1 of 2 groups: control-treated or KF-treated retinal light injury mice. Mice were exposed to 8,000 lux cool white fluorescent light for 2 h to induce light injury. Control or KF was injected intraperitoneally after light injury for 5 days. Scotopic electroretinography (ERG) was recorded before light injury and 7 days after light injury. The retinal morphology and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed after light injury. Results: ERG a- and b-wave amplitudes were significantly reduced in the retinal light injury group compared with the nonretinal light injury group. Retinal light injury produced markedly thinning of the outer nuclear layer along with significant TUNEL-positive signals. In contrast KF treatments significantly attenuated reduction of ERG a- and b- wave amplitudes and the loss of the outer nuclear layer. Conclusions: KF protects retinal photoreceptors and preserves retinal function against retinal degeneration caused by light injury. These initial findings suggest that KF may represent a novel therapy for retinal degenerative conditions such as AMD.


Asunto(s)
Degeneración Macular , Degeneración Retiniana , Ratones , Animales , Degeneración Retiniana/tratamiento farmacológico , Degeneración Retiniana/etiología , Degeneración Retiniana/prevención & control , Quempferoles/farmacología , Retina , Células Fotorreceptoras de Vertebrados , Modelos Animales de Enfermedad , Electrorretinografía , Degeneración Macular/complicaciones , Apoptosis
4.
Environ Res ; 212(Pt D): 113478, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35597288

RESUMEN

This paper investigates the historical sources of soil-lead contamination in Santa Ana, California. Even though dangerous levels of soil-lead have been found in a wide variety of communities across the United States, public health institutions lack clarity on the historical origins of these crises. This study uses geo-spatial data collected through archival research to estimate the impact of two potential sources of lead contamination in the past -- lead-paint and leaded gasoline. It examines, through a combination of statistical and historical methods, the association between lead concentrations in contemporary soil samples and patterns in the evolution of the city's physical features, such as the growth of urbanized areas and the historical flow of traffic. We emphasize the value of historical data collected through archival research for understanding the sources of environmental lead, particularly leaded gasoline, which our study found to be the most likely and most prominent contributor to soil-lead in Santa Ana's environment. This research contributes to environmental-justice advocacy efforts to reframe lead poisoning as a systemic environmental issue and outlines the path forward to community-level remediation strategies.


Asunto(s)
Intoxicación por Plomo , Contaminantes del Suelo , Monitoreo del Ambiente , Gasolina , Humanos , Plomo/análisis , Suelo , Contaminantes del Suelo/análisis
5.
Am J Ind Med ; 65(6): 468-482, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35426145

RESUMEN

BACKGROUND: Many workers seek care for work-related medical conditions in primary care settings. Additionally, occupational medicine training is not consistently addressed in primary care professional training. These patterns raise concerns about the health outcomes of low-wage Latina/o immigrant workers who make use of primary care settings to obtain care for work-related injuries and illnesses. The objective of this qualitative study was to investigate how primary care clinicians assessed and addressed the role of occupational exposures on the health and well-being of Latina/o immigrant workers. METHODS: We conducted semistructured in-depth interviews with 17 primary care clinicians (physicians, resident physicians, and nurse practitioners) employed in an urban federally qualified health center (FQHC) with two sites located in Orange County, CA. RESULTS: Using a constructivist grounded theory approach, we determined that primary care clinicians had a general understanding that employment influenced the health and well-being of their Latina/o immigrant patients. Clinicians delivered care to Latina/o immigrant workers who feared reporting their injury to their employer and to Latina/o immigrants whose workers' compensation claim was terminated before making a full recovery. Clinicians were responsive to patients' work-related concerns and leveraged the resources available within the FQHC. Although some clinicians offered suggestions to improve occupational health in the FQHC, a few clinicians raised concerns about the feasibility of additional health screenings and clinic-based interventions, and pointed to the importance of interventions outside of the healthcare system. CONCLUSION: This study underscores the complexities of addressing occupational health concerns in urban FQHCs.


Asunto(s)
Emigrantes e Inmigrantes , Salud Laboral , Hispánicos o Latinos , Humanos , Atención Primaria de Salud , Indemnización para Trabajadores
6.
PLoS One ; 16(6): e0253578, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34166421

RESUMEN

RATIONALE: There is little doubt that aerosols play a major role in the transmission of SARS-CoV-2. The significance of the presence and infectivity of this virus on environmental surfaces, especially in a hospital setting, remains less clear. OBJECTIVES: We aimed to analyze surface swabs for SARS-CoV-2 RNA and infectivity, and to determine their suitability for sequence analysis. METHODS: Samples were collected during two waves of COVID-19 at the University of California, Davis Medical Center, in COVID-19 patient serving and staff congregation areas. qRT-PCR positive samples were investigated in Vero cell cultures for cytopathic effects and phylogenetically assessed by whole genome sequencing. MEASUREMENTS AND MAIN RESULTS: Improved cleaning and patient management practices between April and August 2020 were associated with a substantial reduction of SARS-CoV-2 qRT-PCR positivity (from 11% to 2%) in hospital surface samples. Even though we recovered near-complete genome sequences in some, none of the positive samples (11 of 224 total) caused cytopathic effects in cultured cells suggesting this nucleic acid was either not associated with intact virions, or they were present in insufficient numbers for infectivity. Phylogenetic analysis suggested that the SARS-CoV-2 genomes of the positive samples were derived from hospitalized patients. Genomic sequences isolated from qRT-PCR negative samples indicate a superior sensitivity of viral detection by sequencing. CONCLUSIONS: This study confirms the low likelihood that SARS-CoV-2 contamination on hospital surfaces contains infectious virus, disputing the importance of fomites in COVID-19 transmission. Ours is the first report on recovering near-complete SARS-CoV-2 genome sequences directly from environmental surface swabs.


Asunto(s)
COVID-19/genética , Genoma Viral , Hospitales de Enseñanza , Filogenia , SARS-CoV-2/genética , Análisis de Secuencia de ARN , Animales , COVID-19/epidemiología , COVID-19/transmisión , Chlorocebus aethiops , Humanos , SARS-CoV-2/aislamiento & purificación , Células Vero
7.
Phys Chem Chem Phys ; 23(14): 8800-8808, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33876039

RESUMEN

Using density functional theory (DFT) calculations, we examined the effects of substitutional doping on the formation of Cu vacancies in Cu2O(111). Upon replacing coordinatively unsaturated O with other elements (N, F, P, S, and Cl) and calculating the formation energies, we found that compared to the undoped surface, Cu vacancy formation is most favorable in the F-doped surface and least favorable in the N-doped Cu2O(111) surface. In addition, we found that in most cases, vacancy formation of the coordinatively saturated Cu has higher vacancy formation energy than coordinatively unsaturated Cu atoms. In the electron localization function plots and the projected charge distributions of the local density of states, we found bonding enhancement between Cu and N in N-Cu2O(111) but no corresponding enhancement was observed in the F-doped surface. Our results showed that the interaction between the substitutional dopants and the Cu atoms affects the formation of the doped system and the Cu vacancy formation in the surface.

8.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21252022

RESUMEN

RationaleThere is little doubt that aerosols play a major role in the transmission of SARS-CoV-2. The significance of the presence and infectivity of this virus on environmental surfaces, especially in a hospital setting, remains less clear. ObjectivesWe aimed to analyze surface swabs for SARS-CoV-2 RNA and infectivity, and to determine their suitability for sequence analysis. MethodsSamples were collected during two waves of COVID-19 at the University of California, Davis Medical Center, in COVID-19 patient serving and staff congregation areas. qRT-PCR positive samples were investigated in Vero cell cultures for cytopathic effects and phylogenetically assessed by whole genome sequencing. Measurements and Main ResultsImproved cleaning and patient management practices between April and August 2020 were associated with a substantial reduction of SARS-CoV-2 qRT-PCR positivity (from 11% to 2%) in hospital surface samples. Even though we recovered near-complete genome sequences in some, none of the positive samples (11 of 224 total) caused cytopathic effects in cultured cells suggesting this nucleic acid was either not associated with intact virions, or they were present in insufficient numbers for infectivity. Phylogenetic analysis suggested that the SARS-CoV-2 genomes of the positive samples were derived from hospitalized patients. Genomic sequences isolated from qRT-PCR negative samples indicate a superior sensitivity of viral detection by sequencing. ConclusionsThis study confirms the low likelihood that SARS-CoV-2 contamination on hospital surfaces contains infectious virus, disputing the importance of fomites in COVID-19 transmission. Ours is the first report on recovering near-complete SARS-CoV-2 genome sequences directly from environmental surface swabs.

9.
Mymensingh Med J ; 29(4): 951-955, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33116101

RESUMEN

The incidence of visceral pain among caesarean section can be as high as 50% in sub arachnoid block (SAB) in spite adequate sensory block, which requires conversion to general anesthesia. Different types of adjuvant have been used to augment the effect of local anesthetics but their use is limited due to adverse effects. The effect of intrathecal midazolam along with hyperbaric bupivacaine in sub arachnoid block is less known. So this randomized, double blind study was conducted to evaluate the additive effect of 0.4ml midazolam to 0.5% 3ml bupivacaine on sub arachnoid block in scheduled elective caesarean section. This study demonstrated that the addition of intrathecal 0.4ml midazolam to spinal 0.5% bupivacaine kept all the characteristics of block unaffected, furthermore pain score VAS 3.4±1.3 in Group A and 1.8±1.22 in Group B which is statistically significant, the requirement of intraoperative analgesia and also increased the duration of postoperative analgesia that is 130.3±5.4 minute in Group A, 265.1±3.6 minute in Group B and also statistically significant. Therefore addition of 2.0mg midazolam with 0.5% bupivacaine significantly reduces the VAS score, reduces the intraoperative visceral pain and need of analgesia.


Asunto(s)
Anestesia Raquidea , Anestésicos Locales , Midazolam , Dolor Postoperatorio , Anestésicos Locales/uso terapéutico , Bupivacaína , Cesárea , Método Doble Ciego , Femenino , Humanos , Inyecciones Espinales , Midazolam/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/prevención & control , Embarazo , Estudios Prospectivos
11.
Artículo en Inglés | MEDLINE | ID: mdl-30909658

RESUMEN

Although lead has been removed from paint and gasoline sold in the U.S., lead exposures persist, with communities of color and residents in urban and low-income areas at greatest risk for exposure. The persistence of and inequities in lead exposures raise questions about the scope and implementation of policies that address lead as a public health concern. To understand the multi-level nature of lead policies, this paper and case study reviews lead policies at the national level, for the state of California, and for Santa Ana, CA, a dense urban city in Southern California. Through a community-academic partnership process, this analysis examines lead exposure pathways represented, the level of intervention (e.g., prevention, remediation), and whether policies address health inequities. Results indicate that most national and state policies focus on establishing hazardous lead exposure levels in settings and consumer products, disclosing lead hazards, and remediating lead paint. Several policies focus on mitigating exposures rather than primary prevention. The persistence of lead exposures indicates the need to identify sustainable solutions to prevent lead exposures in the first place. We close with recommendations to reduce lead exposures across the life course, consider multiple lead exposure pathways, and reduce and eliminate health inequities related to lead.


Asunto(s)
Equidad en Salud , Política de Salud , Salud Pública , Salud Urbana , California , Ciudades , Humanos , Plomo
12.
Oxid Med Cell Longev ; 2017: 1530230, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29142617

RESUMEN

This study evaluated the response of global histone H4 acetylation (H4ac), histone deacetylase 2 (HDAC2) activity, as well as the production of proinflammatory cytokines and monocyte phenotypes of lean and obese males after exercise. Ten lean and ten obese sedentary men were submitted to one session of strenuous exercise, and peripheral blood mononuclear cells (PBMC) were stimulated in vitro with lipopolysaccharide (LPS). Global H4ac levels, HDAC2 activity in PBMC, and IL-6, IL-8, and TNF-α production were analyzed. Monocyte phenotype was determined in accordance with the expression of CD14 and CD16. At rest, obese individuals presented higher frequency of proinflammatory CD14+CD16+ monocytes. LPS induced a significant augment in global H4ac and in the production of IL-6, IL-8, and TNF-α mainly in obese individuals. After exercise, the increased production of IL-8 and TNF-α and peripheral frequency of CD14+CD16+ were observed in both groups. In addition, exercise also induced a significant hyperacetylation of histone H4 and decreased HDAC2 activity in both nonstimulated and LPS-stimulated PBMC of obese individuals. Our data indicate that the obesity impacts on H4ac levels and that strenuous exercise leads to an enhanced chronic low-grade inflammation profile in obesity via an imbalance on H4ac/HDAC2.


Asunto(s)
Ejercicio Físico , Histona Desacetilasa 2/metabolismo , Histonas/metabolismo , Leucocitos Mononucleares/metabolismo , Obesidad/metabolismo , Acetilación , Adulto , Citocinas/metabolismo , Humanos , Inflamación/metabolismo , Inflamación/patología , Leucocitos Mononucleares/patología , Masculino , Obesidad/patología
13.
J Control Release ; 201: 49-55, 2015 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-25599856

RESUMEN

Tumor drug delivery is a complex phenomenon affected by several elements in addition to drug or delivery vehicle's physico-chemical properties. A key factor is tumor microvasculature with complex effects including convective transport, high interstitial pressure and enhanced vascular permeability due to the presence of "leaky vessels". Current in vitro models of the tumor microenvironment for evaluating drug delivery are oversimplified and, as a result, show poor correlation with in vivo performance. In this study, we report on the development of a novel microfluidic platform that models the tumor microenvironment more accurately, with physiologically and morphologically realistic microvasculature including endothelial cell lined leaky capillary vessels along with 3D solid tumors. Endothelial cells and 3D spheroids of cervical tumor cells were co-cultured in the networks. Drug vehicle screening was demonstrated using GFP gene delivery by different formulations of nanopolymers. The synthetic tumor network was successful in predicting in vivo delivery efficiencies of the drug vehicles. The developed assay will have critical applications both in basic research, where it can be used to develop next generation delivery vehicles, and in drug discovery where it can be used to study drug transport and delivery efficacy in realistic tumor microenvironment, thereby enabling drug compound and/or delivery vehicle screening.


Asunto(s)
Sistemas de Liberación de Medicamentos , Neoplasias/metabolismo , Microambiente Tumoral , Línea Celular , Técnicas de Cocultivo , Células Endoteliales , Técnicas de Transferencia de Gen , Proteínas Fluorescentes Verdes/genética , Células HeLa , Humanos , Microfluídica , Nanopartículas/administración & dosificación , Nanopartículas/química , Plásmidos , Polímeros/administración & dosificación , Polímeros/química
14.
J Pediatr Rehabil Med ; 7(4): 281-94, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25547881

RESUMEN

Endocrinopathies are frequently linked to central nervous system disease, both as early effects prior to the disease diagnosis and/or late effects after the disease has been treated. In particular, tumors and infiltrative diseases of the brain and pituitary, such as craniopharyngioma, optic pathway and hypothalamic gliomas, intracranial germ cell tumor, and Langerhans cell histiocytosis, can present with abnormal endocrine manifestations that precede the development of neurological symptoms. Early endocrine effects include diabetes insipidus, growth failure, obesity, and precocious or delayed puberty. With improving prognosis and treatment of childhood brain tumors, many survivors experience late endocrine effects related to medical and surgical interventions. Chemotherapeutic agents and radiation therapy can affect the hypothalamic-pituitary axes governing growth, thyroid, gonadal, and adrenal function. In addition, obesity and metabolic alterations are frequent late manifestations. Diagnosing and treating both early and late endocrine manifestations can dramatically improve the growth, well-being, and quality of life of patients with childhood central nervous system diseases.


Asunto(s)
Neoplasias Encefálicas/complicaciones , Enfermedades del Sistema Nervioso Central/fisiopatología , Glándulas Endocrinas/fisiopatología , Adolescente , Antineoplásicos/efectos adversos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/radioterapia , Niño , Enfermedades del Sistema Endocrino/inducido químicamente , Enfermedades del Sistema Endocrino/etiología , Trastornos del Crecimiento/etiología , Hormona de Crecimiento Humana/deficiencia , Humanos , Masculino , Obesidad/etiología , Pubertad Precoz/etiología , Radioterapia/efectos adversos , Enfermedades Testiculares/etiología , Enfermedades de la Tiroides/etiología
15.
Lab Chip ; 13(6): 1093-101, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23344641

RESUMEN

Current techniques for mimicking the Blood-Brain Barrier (BBB) largely use incubation chambers (Transwell) separated with a filter and matrix coating to represent and to study barrier permeability. These devices have several critical shortcomings: (a) they do not reproduce critical microenvironmental parameters, primarily anatomical size or hemodynamic shear stress, (b) they often do not provide real-time visualization capability, and (c) they require a large amount of consumables. To overcome these limitations, we have developed a microfluidics based Synthetic Microvasculature model of the Blood-Brain Barrier (SyM-BBB). The SyM-BBB platform is comprised of a plastic, disposable and optically clear microfluidic chip with a microcirculation sized two-compartment chamber. The chamber is designed in such a way as to permit the realization of side-by-side apical and basolateral compartments, thereby simplifying fabrication and facilitating integration with standard instrumentation. The individually addressable apical side is seeded with endothelial cells and the basolateral side can support neuronal cells or conditioned media. In the present study, an immortalized Rat Brain Endothelial cell line (RBE4) was cultured in SyM-BBB with a perfusate of Astrocyte Conditioned Media (ACM). Biochemical analysis showed upregulation of tight junction molecules while permeation studies showed an intact BBB. Finally, transporter assay was successfully demonstrated in SyM-BBB indicating a functional model.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Técnicas Analíticas Microfluídicas/métodos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Línea Celular , Rastreo Celular , Medios de Cultivo Condicionados/química , Dextranos/química , Técnicas Analíticas Microfluídicas/instrumentación , Modelos Biológicos , Permeabilidad , Ratas , Rodamina 123/química
16.
Stem Cells Int ; 2012: 738484, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22792117

RESUMEN

Adult bone marrow mononuclear cells (BM-MNCs) are a potential resource for making Schwann cells to repair damaged peripheral nerves. However, many methods of producing Schwann-like cells can be laborious with the cells lacking a functional phenotype. The objective of this study was to develop a simple and rapid method using autologous BM-MNCs to produce a phenotypic and functional Schwann-like cell. Adult porcine bone marrow was collected and enriched for BM-MNCs using a SEPAX device, then cells cultured in Neurobasal media, 4 mM L-glutamine and 20% serum. After 6-8 days, the cultures expressed Schwann cell markers, S-100, O4, GFAP, were FluoroMyelin positive, but had low p75(NGF) expression. Addition of neuregulin (1-25 nM) increased p75(NGF) levels at 24-48 hrs. We found ATP dose-dependently increased intracellular calcium [Ca(2+)](i), with nucleotide potency being UTP = ATP > ADP > AMP > adenosine. Suramin blocked the ATP-induced [Ca(2+)](i) but α, ß,-methylene-ATP had little effect suggesting an ATP purinergic P2Y2 G-protein-coupled receptor is present. Both the Schwann cell markers and ATP-induced [Ca(2+)](i) sensitivity decreased in cells passaged >20 times. Our studies indicate that autologous BM-MNCs can be induced to form a phenotypic and functional Schwann-like cell which could be used for peripheral nerve repair.

17.
Appl Environ Microbiol ; 78(11): 3824-36, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22447604

RESUMEN

Survival of the food-borne pathogen Listeria monocytogenes in acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affects L. monocytogenes survival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C). L. monocytogenes cells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). For L. monocytogenes grown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response of L. monocytogenes grown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σ(B), σ(H), CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability of L. monocytogenes to survive gastric passage and ultimately cause disease.


Asunto(s)
Frío , Almacenamiento de Alimentos , Regulación Bacteriana de la Expresión Génica , Respuesta al Choque Térmico , Listeria monocytogenes/crecimiento & desarrollo , Viabilidad Microbiana , Adaptación Fisiológica , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Recuento de Colonia Microbiana , Medios de Cultivo , Ácido Gástrico , Perfilación de la Expresión Génica , Humanos , Concentración de Iones de Hidrógeno , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Listeria monocytogenes/fisiología , Análisis de Secuencia por Matrices de Oligonucleótidos
18.
J Dairy Sci ; 95(3): 1568-74, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22365238

RESUMEN

Pseudomonas spp. are common gram-negative, post-pasteurization contaminants that contribute to spoilage of pasteurized dairy products. This study evaluated 5 common selective media for detecting Pseudomonas spp. in pasteurized milk. The performance of each selective medium for recovering 12 different Pseudomonas isolates (selected to represent a diversity of pasteurized milk isolates) was compared with that of standard plate count agar pour plates. Pseudomonas isolates showed varying abilities to produce colonies on different selective media. For 2 of 12 isolates, a 48-h incubation time was required for colony formation on any of the media tested. Violet red bile agar and coliform Petrifilm (3M, St. Paul, MN) were less effective than standard plate count agar pour plates at recovering Pseudomonas, regardless of incubation time, and MacConkey agar showed poor detection efficiency compared with SPCP after a 48-h incubation (R(2) = 0.26). Therefore, the use of violet red bile agar, MacConkey agar, or coliform Petrifilm may not be sufficient for detecting common Pseudomonas spp. in milk. The methods showing the highest detection efficiencies were crystal violet tetrazolium agar (CVTA) pour plates (R(2) = 0.95) and CVTA plates inoculated by spiral plating (R(2) = 0.89) incubated at 32 °C for 48 h. Overall, plating milk samples on CVTA followed by a 48-h incubation at 32 °C was the most effective selective method for recovering a diversity of Pseudomonas spp. from milk.


Asunto(s)
Medios de Cultivo , Leche/microbiología , Pseudomonas/crecimiento & desarrollo , Animales , Bovinos , Microbiología de Alimentos/métodos , Técnicas Microbiológicas/veterinaria , Pasteurización
19.
Int J Pediatr Endocrinol ; 2011: 138903, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21603250

RESUMEN

Graves' disease is less common in prepubertal than pubertal children, and initial presentation with thyroid storm is rare. We report an 11-year-old prepubertal Hispanic girl who presented with a one-day history of respiratory distress, fever, and dysphagia. She had exophthalmos, a diffuse bilateral goiter and was agitated, tachycardic, and hypertensive. Nasal swab was positive for respiratory syncytial virus (RSV). She was diagnosed with thyroid storm and admitted to the pediatric intensive care unit. While infection is a known precipitant of thyroid storm and RSV is a common pediatric infection, to the best of our knowledge, this is the first reported case of RSV infection apparently precipitating thyroid storm in a prepubertal child.

20.
Obes Surg ; 21(7): 930-4, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20957447

RESUMEN

BACKGROUND: Heterozygous mutations in melanocortin-4 receptor (MC4R) are the most frequent genetic cause of obesity. Bariatric surgery is a successful treatment for severe obesity. The mechanisms of weight loss after bariatric surgery are not well understood. METHODS: Ninety-two patients who had Roux-en-Y gastric bypass (RYGB) surgery were screened for MC4R mutations. We compared percent excess weight loss (%EWL) in the four MC4R mutation carriers with that of two control groups: 8 matched controls and with the remaining 80 patients who underwent RYGB. RESULTS: Four patients were heterozygous for functionally significant MC4R mutations. In patients with MC4R mutations, the %EWL after RYGB (66% EWL) was not significantly different compared to matched controls (70% EWL) and non-matched controls (60% EWL) after 1 year of follow-up. CONCLUSIONS: This study suggests that patients with heterozygous MC4R mutations also benefit from RYGB and that weight loss may be independent of the presence of such mutations.


Asunto(s)
Derivación Gástrica , Mutación , Obesidad/genética , Receptor de Melanocortina Tipo 4/genética , Pérdida de Peso/genética , Adulto , Estudios de Casos y Controles , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Obesidad/cirugía
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