Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Rand Health Q ; 11(2): 3, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38601717

RESUMEN

The U.S. Air Force asked RAND Project AIR FORCE (PAF) to help assess the well-being of its wounded members and the quality of services provided to facilitate their recovery and reintegration. RAND PAF fielded a survey in the fall of 2016 to assess wounded airmen's functioning in the domains of physical health, mental health, interpersonal relationships, unemployment, and financial status, as well as their utilization and perceptions of Air Force nonmedical programs for wounded airmen. The authors of this study invited all 713 wounded airmen enrolled in the Air Force Wounded Warrior program to complete the survey, and 270 airmen (38 percent) completed it. One-third of airmen reported difficulty obtaining care for physical or mental health conditions, and one-quarter expressed dissatisfaction with coordination of care. Similar proportions of airmen reported barriers to care for physical and mental health conditions. Difficulty scheduling appointments was the most commonly endorsed barrier for both types of conditions. Small but notable proportions of airmen reported potential social support deficits, unemployment, and financial problems. For many of the Air Force's programs for wounded airmen, over 80 percent of program users reported overall program satisfaction. The authors recommend that the Air Force consider focusing on improving care coordination, increasing health care system capacity, continuing employment assistance, and improving marketing of programs with low uptake.

2.
Curr Opin Allergy Clin Immunol ; 24(3): 147-152, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38547423

RESUMEN

PURPOSE OF REVIEW: This review aims to explore role of emerging biologics, including ligelizumab, UB-221, dupilumab, and antialarmins, in food allergy management. With a focus on recent developments, we evaluate their promise in mitigating adverse events during oral immunotherapy (OIT), reducing allergic reactions, and addressing the limitations of current therapeutic options. RECENT FINDINGS: Antiimmunoglobulin E mAbs, exemplified by omalizumab, demonstrate efficacy in desensitization and safety improvement during multiallergen OIT. Next-generation antibodies like ligelizumab and UB-221 exhibit enhanced potency and unique mechanisms, holding promise for food allergy treatment. Dupilumab, targeting IL-4 receptor alpha, presents potential benefits in decreasing allergen-specific IgE and modifying the atopic march. Exploration of antialarmins, specifically anti-IL-33 (etokimab) and anti-TSLP (tezepelumab), reveals encouraging results, with etokimab showing early success in peanut allergy trials. SUMMARY: Biologics hold promising potential for food allergy treatment. Tailoring therapeutic approaches based on shared decision-making becomes pivotal. While omalizumab remains a significant option, next-generation anti-IgE antibodies and agents targeting alarmins exhibit unique strengths. Dupilumab, despite limited success as monotherapy, shows promise as an adjunct for OIT. Careful consideration of treatment goals, patient preferences, and the evolving landscape of biologics will shape future clinical practice, offering allergists an expanded toolbox for personalized food allergy management.


Asunto(s)
Productos Biológicos , Hipersensibilidad a los Alimentos , Humanos , Hipersensibilidad a los Alimentos/inmunología , Hipersensibilidad a los Alimentos/terapia , Hipersensibilidad a los Alimentos/tratamiento farmacológico , Productos Biológicos/uso terapéutico , Productos Biológicos/efectos adversos , Desensibilización Inmunológica/métodos , Animales , Antialérgicos/uso terapéutico , Inmunoglobulina E/inmunología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales/uso terapéutico , Alérgenos/inmunología , Omalizumab/uso terapéutico
3.
J Biol Chem ; 299(12): 105363, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37863262

RESUMEN

Metformin is among the most prescribed medications worldwide and the first-line therapy for type 2 diabetes. However, gastrointestinal side effects are common and can be dose limiting. The total daily metformin dose frequently reaches several grams, and poor absorption results in high intestinal drug concentrations. Here, we report that metformin inhibits the activity of enteropeptidase and other digestive enzymes at drug concentrations predicted to occur in the human duodenum. Treatment of mouse gastrointestinal tissue with metformin reduces enteropeptidase activity; further, metformin-treated mice exhibit reduced enteropeptidase activity, reduced trypsin activity, and impaired protein digestion within the intestinal lumen. These results indicate that metformin-induced protein maldigestion could contribute to the gastrointestinal side effects and other impacts of this widely used drug.


Asunto(s)
Enteropeptidasa , Metformina , Proteolisis , Animales , Humanos , Ratones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Enteropeptidasa/metabolismo , Metformina/efectos adversos , Metformina/farmacología , Metformina/uso terapéutico , Proteolisis/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Tracto Gastrointestinal/enzimología , Tripsina/metabolismo , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico
4.
Ann Allergy Asthma Immunol ; 131(1): 29-36, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37100276

RESUMEN

The prevalence of food allergy (FA) has been increasing globally and comes with a heavy burden not just economically, but also on quality of life. Although oral immunotherapy (OIT) is effective at inducing desensitization to food allergens, it has several limitations that weaken its success. Limitations include a long duration of build-up, especially when used for multiple allergens, and a high rate of reported adverse events. Furthermore, OIT may not be effective in all patients. Efforts are underway to identify additional treatment options, either as monotherapy or in combination, to treat FA or enhance the safety and efficacy of OIT. Biologics such as omalizumab and dupilumab, which already have US Food and Drug Administration approval for other atopic conditions have been the most studied, but additional biologics and novel strategies are emerging. In this review, we discuss therapeutic strategies including immunoglobulin E inhibitors, immunoglobulin E disruptors, interleukin-4 and interleukin-13 inhibitors, antialarmins, JAK1 and BTK inhibitors, and nanoparticles, and the data surrounding their application in FA and highlighting their potential.


Asunto(s)
Productos Biológicos , Hipersensibilidad a los Alimentos , Humanos , Desensibilización Inmunológica/efectos adversos , Productos Biológicos/uso terapéutico , Calidad de Vida , Administración Oral , Inmunoterapia , Alérgenos , Inmunoglobulina E
5.
Front Allergy ; 4: 1089308, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36814725

RESUMEN

Introduction: Epicutaneous immunotherapy (EPIT) has been tested in clinical trials for children with peanut allergy (PA) for its safety and efficacy in inducing desensitization. Aside from peanut avoidance and symptom management, oral immunotherapy (OIT) is another option for PA patients. However, OIT can be associated with adverse events and pose safety concerns to children and their caregivers. Methods: This study assessed 27 children who successfully completed a peanut EPIT trial. 18 of them transitioned to peanut OIT with starting doses ranging from 10-600 mg of peanut protein. Our aim was to learn more about the EPIT to OIT experience through descriptive survey responses and to gather information that may support the sequential use of the two immunotherapies for safe and positive outcomes that may not be achieved by either alone. Results: Overall, children and their caregivers had less anxiety about starting OIT after having had peanut exposure through EPIT. Most children who transitioned from EPIT to OIT had no or minor symptoms initially, with symptoms lessening later in OIT. Most were also able to maintain or increase their peanut dose over time, achieving maintenance doses of 60-2,000 mg. Discussion: In comparison with current literature on OIT for PA in children, the reported symptoms appeared less severe and less prevalent in the EPIT to OIT group. However, there were 3 participants who withdrew from OIT due to the development of intolerable symptoms. This study provides initial data in support of EPIT to OIT, and larger randomized controlled trials assessing effectiveness of the two therapies together are warranted.

6.
Nucleic Acids Res ; 50(2): 847-866, 2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-34967415

RESUMEN

The nucleotide messenger (p)ppGpp allows bacteria to adapt to fluctuating environments by reprogramming the transcriptome. Despite its well-recognized role in gene regulation, (p)ppGpp is only known to directly affect transcription in Proteobacteria by binding to the RNA polymerase. Here, we reveal a different mechanism of gene regulation by (p)ppGpp in Firmicutes: (p)ppGpp directly binds to the transcription factor PurR to downregulate purine biosynthesis gene expression upon amino acid starvation. We first identified PurR as a receptor of (p)ppGpp in Bacillus anthracis. A co-structure with Bacillus subtilis PurR reveals that (p)ppGpp binds to a PurR pocket reminiscent of the active site of phosphoribosyltransferase enzymes that has been repurposed to serve a purely regulatory role, where the effectors (p)ppGpp and PRPP compete to allosterically control transcription. PRPP inhibits PurR DNA binding to induce transcription of purine synthesis genes, whereas (p)ppGpp antagonizes PRPP to enhance PurR DNA binding and repress transcription. A (p)ppGpp-refractory purR mutant in B. subtilis fails to downregulate purine synthesis genes upon amino acid starvation. Our work establishes the precedent of (p)ppGpp as an effector of a classical transcription repressor and reveals the key function of (p)ppGpp in regulating nucleotide synthesis through gene regulation, from soil bacteria to pathogens.


Asunto(s)
Bacillus subtilis/metabolismo , Proteínas Bacterianas/metabolismo , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/metabolismo , Guanosina Pentafosfato/metabolismo , Guanosina Tetrafosfato/metabolismo , Proteínas Represoras/metabolismo , Sitios de Unión , Regulación Bacteriana de la Expresión Génica
7.
Cancer Med ; 11(1): 238-244, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34816614

RESUMEN

INTRODUCTION: The American Cancer Society, Inc. (ACS) estimates that 37,940 Indiana residents were diagnosed with cancer in 2020, which remains the leading cause of death in the state. Across the cancer continuum, national goals have been established targeting recommended benchmarks for states in prevention, screening, treatment, and survivorship. Indiana consistently falls below most goals for each of these targeted categories. METHODS: To address these disparities, we implemented Project ECHO (Extension for Community Healthcare Outcomes) as a virtual telehealth educational platform targeted at local healthcare providers. ECHO programs utilize a novel tele-mentoring approach to the education of clinicians in a hub/spoke design. Sessions occurred twice monthly from September 2019 to September 2020 and consisted of a traditional didactic lecture and a case-based discussion led by participating providers. RESULTS: During the pilot year there were a total of 22 ECHO sessions with 140 different participants. On average, 15.5 spokes attended each session with increasing participation at the end of the year. Post-session surveys suggested generally favorable perception with 72% of respondents finding the quality "excellent." DISCUSSION: Given the increasing rate of recurrent participation toward the end of the pilot year in conjunction with the favorable survey responses following each session, it was felt that the program was overall successful and warranted continued implementation. CONCLUSION: The Project ECHO platform is a validated telehealth education platform that has the potential to impact cancer care at multiple points along the cancer continuum at the regional level.


Asunto(s)
Detección Precoz del Cáncer , Personal de Salud/educación , Neoplasias/prevención & control , Supervivencia , Telemedicina/métodos , Curriculum , Humanos , Indiana , Neoplasias/diagnóstico , Proyectos Piloto , Evaluación de Programas y Proyectos de Salud
8.
J Asthma Allergy ; 14: 1497-1510, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34934327

RESUMEN

Oral immunotherapy (OIT) in pediatric patients provides an alternative option to the current standard of care in food allergy, which is allergen avoidance and reactive treatment. Because patients are exposed to one or more food allergens during treatment, OIT is associated with adverse events and can be a cumbersome process for children, their caregivers, and clinicians. However, there have been an overwhelming number of studies that show high efficacy in both single- and multi-allergen OIT, and that quality of life is greatly improved for both patients and their families after undergoing immunotherapy. This review discusses clinical considerations for OIT in pediatrics, including efficacy and safety, practical management, and future directions of treatment.

9.
mBio ; 12(4): e0065621, 2021 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-34465018

RESUMEN

Human gut microbes exhibit a spectrum of cooperative and antagonistic interactions with their host and also with other microbes. The major Bacteroides host-targeting virulence factor, Bacteroides fragilis toxin (BFT), is produced as an inactive protoxin by enterotoxigenic B. fragilis strains. BFT is processed by the conserved bacterial cysteine protease fragipain (Fpn), which is also encoded in B. fragilis strains that lack BFT. In this report, we identify a secreted antibacterial protein (fragipain-activated bacteriocin 1 [Fab1]) and its cognate immunity protein (resistance to fragipain-activated bacteriocin 1 [RFab1]) in enterotoxigenic and nontoxigenic strains of B. fragilis. Although BFT and Fab1 share no sequence identity, Fpn also activates the Fab1 protoxin, resulting in its secretion and antibacterial activity. These findings highlight commonalities between host- and bacterium-targeting toxins in intestinal bacteria and suggest that antibacterial antagonism may promote the conservation of pathways that activate host-targeting virulence factors. IMPORTANCE The human intestine harbors a highly complex microbial community; interpersonal variation in this community can impact pathogen susceptibility, metabolism, and other aspects of health. Here, we identified and characterized a commensal-targeting antibacterial protein encoded in the gut microbiome. Notably, a shared pathway activates this antibacterial toxin and a host-targeting toxin. These findings highlight unexpected commonalities between host- and bacterium-targeting toxins in intestinal bacteria.


Asunto(s)
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Microbioma Gastrointestinal/genética , Interacciones Microbiota-Huesped , Intestinos/microbiología , Redes y Vías Metabólicas/genética , Animales , Antibacterianos/biosíntesis , Antibacterianos/aislamiento & purificación , Toxinas Bacterianas/metabolismo , Bacteriocinas/genética , Bacteroides fragilis/genética , Bacteroides fragilis/metabolismo , Femenino , Humanos , Masculino , Metaloendopeptidasas/metabolismo , Ratones Endogámicos C57BL
10.
Annu Rev Genet ; 55: 115-133, 2021 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-34416118

RESUMEN

Bacterial stress-signaling alarmones are important components of a protective network against diverse stresses such as nutrient starvation and antibiotic assault. pppGpp and ppGpp, collectively (p)ppGpp, have well-documented regulatory roles in gene expression and protein translation. Recent work has highlighted another key function of (p)ppGpp: inducing rapid and coordinated changes in cellular metabolism by regulating enzymatic activities, especially those involved in purine nucleotide synthesis. Failure of metabolic regulation by (p)ppGpp results in the loss of coordination between metabolic and macromolecular processes, leading to cellular toxicity. In this review, we document how (p)ppGpp and newly characterized nucleotides pGpp and (p)ppApp directly regulate these enzymatic targets for metabolic remodeling. We examine targets' common determinants for alarmone interaction as well as their evolutionary diversification. We highlight classical and emerging themes in nucleotide signaling, including oligomerization and allostery along with metabolic interconversion and crosstalk, illustrating how they allow optimized bacterial adaptation to their environmental niches.


Asunto(s)
Guanosina Pentafosfato , Nucleótidos , Bacterias/genética , Bacterias/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Guanosina Pentafosfato/genética , Guanosina Pentafosfato/metabolismo , Nucleótidos/metabolismo
12.
Nat Commun ; 11(1): 5388, 2020 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-33097692

RESUMEN

The alarmone nucleotides guanosine tetraphosphate and pentaphosphate, commonly referred to as (p)ppGpp, regulate bacterial responses to nutritional and other stresses. There is evidence for potential existence of a third alarmone, guanosine-5'-monophosphate-3'-diphosphate (pGpp), with less-clear functions. Here, we demonstrate the presence of pGpp in bacterial cells, and perform a comprehensive screening to identify proteins that interact respectively with pGpp, ppGpp and pppGpp in Bacillus species. Both ppGpp and pppGpp interact with proteins involved in inhibition of purine nucleotide biosynthesis and with GTPases that control ribosome assembly or activity. By contrast, pGpp interacts with purine biosynthesis proteins but not with the GTPases. In addition, we show that hydrolase NahA (also known as YvcI) efficiently produces pGpp by hydrolyzing (p)ppGpp, thus modulating alarmone composition and function. Deletion of nahA leads to reduction of pGpp levels, increased (p)ppGpp levels, slower growth recovery from nutrient downshift, and loss of competitive fitness. Our results support the existence and physiological relevance of pGpp as a third alarmone, with functions that can be distinct from those of (p)ppGpp.


Asunto(s)
Bacillus/metabolismo , Proteínas Bacterianas/metabolismo , Nucleótidos de Guanina/metabolismo , Nucleótidos/metabolismo , Bacillus/genética , Bacillus anthracis/metabolismo , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Guanosina Tetrafosfato/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Unión Proteica , Biosíntesis de Proteínas
13.
J Mol Biol ; 432(14): 4108-4126, 2020 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-32446804

RESUMEN

The alarmones pppGpp and ppGpp mediate starvation response and maintain purine homeostasis to protect bacteria. In the bacterial phyla Firmicutes and Bacteroidetes, xanthine phosphoribosyltransferase (XPRT) is a purine salvage enzyme that produces the nucleotide XMP from PRPP and xanthine. Combining structural, biochemical, and genetic analyses, we show that pppGpp and ppGpp, as well as a third newly identified alarmone pGpp, all directly interact with XPRT from the Gram-positive bacterium Bacillus subtilis and inhibit XPRT activity by competing with its substrate PRPP. Structural analysis reveals that ppGpp binds the PRPP binding motif within the XPRT active site. This motif is present in another (p)ppGpp target, the purine salvage enzyme HPRT, suggesting evolutionary conservation in different enzymes. However, XPRT oligomeric interaction is distinct from HPRT in that XPRT forms a symmetric dimer with two (p)ppGpp binding sites at the dimer interface. (p)ppGpp's interaction with an XPRT bridging loop across the interface results in XPRT cooperatively binding (p)ppGpp. Also, XPRT displays differential regulation by the alarmones as it is potently inhibited by both ppGpp and pGpp, but only modestly by pppGpp. Lastly, we demonstrate that the alarmones are necessary for protecting GTP homeostasis against excess environmental xanthine in B. subtilis, suggesting that regulation of XPRT is key for regulating the purine salvage pathway.


Asunto(s)
Guanosina Pentafosfato/genética , Guanosina Tetrafosfato/genética , Pentosiltransferasa/genética , Purinas/metabolismo , Bacillus subtilis/enzimología , Regulación Bacteriana de la Expresión Génica/genética , Humanos , Nucleótidos/genética , Unión Proteica/genética
15.
Elife ; 82019 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-31552824

RESUMEN

The alarmone (p)ppGpp regulates diverse targets, yet its target specificity and evolution remain poorly understood. Here, we elucidate the mechanism by which basal (p)ppGpp inhibits the purine salvage enzyme HPRT by sharing a conserved motif with its substrate PRPP. Intriguingly, HPRT regulation by (p)ppGpp varies across organisms and correlates with HPRT oligomeric forms. (p)ppGpp-sensitive HPRT exists as a PRPP-bound dimer or an apo- and (p)ppGpp-bound tetramer, where a dimer-dimer interface triggers allosteric structural rearrangements to enhance (p)ppGpp inhibition. Loss of this oligomeric interface results in weakened (p)ppGpp regulation. Our results reveal an evolutionary principle whereby protein oligomerization allows evolutionary change to accumulate away from a conserved binding pocket to allosterically alter specificity of ligand interaction. This principle also explains how another (p)ppGpp target GMK is variably regulated across species. Since most ligands bind near protein interfaces, we propose that this principle extends to many other protein-ligand interactions.


Asunto(s)
Bacillus subtilis/enzimología , Guanosina Pentafosfato/metabolismo , Guanosina Tetrafosfato/metabolismo , Hipoxantina Fosforribosiltransferasa/antagonistas & inhibidores , Regulación Alostérica , Cristalografía por Rayos X , Escherichia coli/enzimología , Hipoxantina Fosforribosiltransferasa/química , Hipoxantina Fosforribosiltransferasa/metabolismo , Conformación Proteica , Multimerización de Proteína
16.
PLoS One ; 10(7): e0130697, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26136239

RESUMEN

Timely and accurate measurement of population protection against measles is critical for decision-making and prevention of outbreaks. However, little is known about how survey-based estimates of immunization (crude coverage) compare to the seroprevalence of antibodies (effective coverage), particularly in low-resource settings. In poor areas of Mexico and Nicaragua, we used household surveys to gather information on measles immunization from child health cards and caregiver recall. We also collected dried blood spots (DBS) from children aged 12 to 23 months to compare crude and effective coverage of measles immunization. We used survey-weighted logistic regression to identify individual, maternal, household, community, and health facility characteristics that predict gaps between crude coverage and effective coverage. We found that crude coverage was significantly higher than effective coverage (83% versus 68% in Mexico; 85% versus 50% in Nicaragua). A large proportion of children (19% in Mexico; 43% in Nicaragua) had health card documentation of measles immunization but lacked antibodies. These discrepancies varied from 0% to 100% across municipalities in each country. In multivariate analyses, card-positive children in Mexico were more likely to lack antibodies if they resided in urban areas or the jurisdiction of De Los Llanos. In contrast, card-positive children in Nicaragua were more likely to lack antibodies if they resided in rural areas or the North Atlantic region, had low weight-for-age, or attended health facilities with a greater number of refrigerators. Findings highlight that reliance on child health cards to measure population protection against measles is unwise. We call for the evaluation of immunization programs using serological methods, especially in poor areas where the cold chain is likely to be compromised. Identification of within-country variation in effective coverage of measles immunization will allow researchers and public health professionals to address challenges in current immunization programs.


Asunto(s)
Anticuerpos Antivirales/sangre , Programas de Inmunización/estadística & datos numéricos , Vacuna Antisarampión/administración & dosificación , Sarampión/prevención & control , Vacunación/estadística & datos numéricos , Adolescente , Adulto , Preescolar , Países en Desarrollo , Pruebas con Sangre Seca , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Femenino , Encuestas de Atención de la Salud/estadística & datos numéricos , Registros de Salud Personal , Humanos , Programas de Inmunización/economía , Lactante , Masculino , Sarampión/sangre , Sarampión/inmunología , Sarampión/virología , Vacuna Antisarampión/economía , Vacuna Antisarampión/provisión & distribución , Virus del Sarampión/inmunología , Virus del Sarampión/aislamiento & purificación , México , Persona de Mediana Edad , Nicaragua , Vacunación/instrumentación
17.
J Bacteriol ; 197(18): 2908-19, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26124242

RESUMEN

UNLABELLED: The bacterial stringent response (SR) is a conserved stress tolerance mechanism that orchestrates physiological alterations to enhance cell survival. This response is mediated by the intracellular accumulation of the alarmones pppGpp and ppGpp, collectively called (p)ppGpp. In Enterococcus faecalis, (p)ppGpp metabolism is carried out by the bifunctional synthetase/hydrolase E. faecalis Rel (RelEf) and the small alarmone synthetase (SAS) RelQEf. Although Rel is the main enzyme responsible for SR activation in Firmicutes, there is emerging evidence that SASs can make important contributions to bacterial homeostasis. Here, we showed that RelQEf synthesizes ppGpp more efficiently than pppGpp without the need for ribosomes, tRNA, or mRNA. In addition to (p)ppGpp synthesis from GDP and GTP, RelQEf also efficiently utilized GMP to form GMP 3'-diphosphate (pGpp). Based on this observation, we sought to determine if pGpp exerts regulatory effects on cellular processes affected by (p)ppGpp. We found that pGpp, like (p)ppGpp, strongly inhibits the activity of E. faecalis enzymes involved in GTP biosynthesis and, to a lesser extent, transcription of rrnB by Escherichia coli RNA polymerase. Activation of E. coli RelA synthetase activity was observed in the presence of both pGpp and ppGpp, while RelQEf was activated only by ppGpp. Furthermore, enzymatic activity of RelQEf is insensitive to relacin, a (p)ppGpp analog developed as an inhibitor of "long" RelA/SpoT homolog (RSH) enzymes. We conclude that pGpp can likely function as a bacterial alarmone with target-specific regulatory effects that are similar to what has been observed for (p)ppGpp. IMPORTANCE: Accumulation of the nucleotide second messengers (p)ppGpp in bacteria is an important signal regulating genetic and physiological networks contributing to stress tolerance, antibiotic persistence, and virulence. Understanding the function and regulation of the enzymes involved in (p)ppGpp turnover is therefore critical for designing strategies to eliminate the protective effects of this molecule. While characterizing the (p)ppGpp synthetase RelQ of Enterococcus faecalis (RelQEf), we found that, in addition to (p)ppGpp, RelQEf is an efficient producer of pGpp (GMP 3'-diphosphate). In vitro analysis revealed that pGpp exerts complex, target-specific effects on processes known to be modulated by (p)ppGpp. These findings provide a new regulatory feature of RelQEf and suggest that pGpp may represent a new member of the (pp)pGpp family of alarmones.


Asunto(s)
Enterococcus faecalis/enzimología , Enterococcus faecalis/metabolismo , Guanosina Pentafosfato/metabolismo , Guanosina Tetrafosfato/biosíntesis , Ligasas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/biosíntesis , Desoxiguanosina/química , Dipéptidos/biosíntesis , Dipéptidos/química , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/genética , Regulación Bacteriana de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Ligasas/genética , Magnesio , Estructura Molecular , Estrés Fisiológico , Especificidad por Sustrato
18.
BMC Med ; 13: 164, 2015 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-26170012

RESUMEN

BACKGROUND: Individual income and poverty are associated with poor health outcomes. The poor face unique challenges related to access, education, financial capacity, environmental effects, and other factors that threaten their health outcomes. METHODS: We examined the variation in the health outcomes and health behaviors among the poorest quintile in eight countries of Mesoamerica using data from the Salud Mesomérica 2015 baseline household surveys. We used multivariable logistic regression to measure the association between delivering a child in a health facility and select household and maternal characteristics, including education and measures of wealth. RESULTS: Health indicators varied greatly between geographic segments. Controlling for other demographic characteristics, women with at least secondary education were more likely to have an in-facility delivery compared to women who had not attended school (OR: 3.20, 95 % confidence interval [CI]: 2.56-3.99, respectively). Similarly, women from households with the highest expenditure were more likely to deliver in a health facility compared to those from the lowest expenditure households (OR 3.06, 95 % CI: 2.43-3.85). Household assets did not impact these associations. Moreover, we found that commonly-used definitions of poverty do not align with the disparities in health outcomes observed in these communities. CONCLUSIONS: Although poverty measured by expenditure or wealth is associated with health disparities or health outcomes, a composite indicator of health poverty based on coverage is more likely to focus attention on health problems and solutions. Our findings call for the public health community to define poverty by health coverage measures rather than income or wealth. Such a health-poverty metric is more likely to generate attention and mobilize targeted action by the health communities than our current definition of poverty.


Asunto(s)
Países en Desarrollo/economía , Países en Desarrollo/estadística & datos numéricos , Indicadores de Salud , Pobreza/estadística & datos numéricos , Adulto , América Central/epidemiología , Composición Familiar , Femenino , Humanos , Renta/estadística & datos numéricos , Modelos Logísticos , Embarazo , Encuestas y Cuestionarios
19.
Popul Health Metr ; 13(1): 3, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25685074

RESUMEN

BACKGROUND: Health has improved markedly in Mesoamerica, the region consisting of southern Mexico and Central America, over the past decade. Despite this progress, there remain substantial inequalities in health outcomes, access, and quality of medical care between and within countries. Poor, indigenous, and rural populations have considerably worse health indicators than national or regional averages. In an effort to address these health inequalities, the Salud Mesoamérica 2015 Initiative (SM2015), a results-based financing initiative, was established. METHODS: For each of the eight participating countries, health targets were set to measure the progress of improvements in maternal and child health produced by the Initiative. To establish a baseline, we conducted censuses of 90,000 households, completed 20,225 household interviews, and surveyed 479 health facilities in the poorest areas of Mesoamerica. Pairing health facility and household surveys allows us to link barriers to care and health outcomes with health system infrastructure components and quality of health services. RESULTS: Indicators varied significantly within and between countries. Anemia was most prevalent in Panama and least prevalent in Honduras. Anemia varied by age, with the highest levels observed among children aged 0 to 11 months in all settings. Belize had the highest proportion of institutional deliveries (99%), while Guatemala had the lowest (24%). The proportion of women with four antenatal care visits with a skilled attendant was highest in El Salvador (90%) and the lowest in Guatemala (20%). Availability of contraceptives also varied. The availability of condoms ranged from 83% in Nicaragua to 97% in Honduras. Oral contraceptive pills and injectable contraceptives were available in just 75% of facilities in Panama. IUDs were observed in only 21.5% of facilities surveyed in El Salvador. CONCLUSIONS: These data provide a baseline of much-needed information for evidence-based action on health throughout Mesoamerica. Our baseline estimates reflect large disparities in health indicators within and between countries and will facilitate the evaluation of interventions and investments deployed in the region over the next three to five years. SM2015's innovative monitoring and evaluation framework will allow health officials with limited resources to identify and target areas of greatest need.

20.
Injury ; 43(7): 1176-81, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22541760

RESUMEN

INTRODUCTION: Leg length discrepancy (LLD) following intramedullary nailing of femoral fractures is not uncommon. We designed a prospective study to evaluate the efficacy of routine postoperative computed tomography (CT) scanograms for evaluation of limb length discrepancy in patients with comminuted Winquist III or IV femoral shaft fractures treated with intramedullary nailing. METHODS: The study consisted of 15 patients with Winquist III and 13 with a Winquist IV femoral shaft fracture pattern with an average age of 37 years. The mechanisms of injury were motor vehicle collision (13), gunshot wound (12) and falls (three). All patients were treated with a statically locked intramedullary femoral nail (18 antegrade and 10 retrograde). A CT scanogram evaluated limb length in all patients. A discrepancy of greater than 20mm was considered for correction during the same admission. An LLD of 15-20mm was discussed with the patient extensively for correction. RESULTS: In the 28 patients included in our study, the average limb length discrepancy was 9.1mm with a range of -43.5mm short to 10.3mm long. The LLD was less than 10mm in 18 patients (64%), 10-15mm in four patients (14%), 15-20mm in three patients (11%) and more than 20mm in three patients (11%). Measurement of discrepancy as small as 0.5mm showed that 18 patients were fixed with shortening and in 10 patients the operated femur was longer. Tibia lengths were also evaluated separately. Though none of the tibiae had a previous fracture, only three patients (10%) had tibiae of equal length. In 13 patients, an unequal tibia partially corrected the LLD whilst in 12 it added to the discrepancy. Five patients with LLD of greater than 15mm underwent correction. CONCLUSIONS: A postoperative scanogram in patients with comminuted femoral shaft fractures treated with intramedullary nailing is useful to evaluate LLD and allows for early intervention. The ideal length where correction is necessary remains unclear.


Asunto(s)
Fracturas del Fémur/diagnóstico por imagen , Fémur/diagnóstico por imagen , Fijación Intramedular de Fracturas/efectos adversos , Fracturas Conminutas/diagnóstico por imagen , Diferencia de Longitud de las Piernas/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Accidentes por Caídas , Accidentes de Tránsito , Adulto , Femenino , Fracturas del Fémur/complicaciones , Fracturas del Fémur/patología , Fracturas del Fémur/cirugía , Fémur/patología , Fracturas Conminutas/complicaciones , Fracturas Conminutas/patología , Fracturas Conminutas/cirugía , Humanos , Diferencia de Longitud de las Piernas/etiología , Masculino , Satisfacción del Paciente , Estudios Prospectivos , Resultado del Tratamiento , Heridas por Arma de Fuego
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...