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1.
J Am Assoc Nurse Pract ; 35(8): 468-476, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37163454

RESUMEN

BACKGROUND: Psyllium is a natural, predominantly soluble fiber that forms a viscous gel when hydrated and is not digested or fermented. In the small intestine, psyllium gel increases chyme viscosity, slowing the degradation and absorption of nutrients. Psyllium has a significant effect in patients with metabolic syndrome and type-2 diabetes on glycemic control, while lowering serum cholesterol in hypercholesterolemic patients. Some randomized controlled studies have shown that psyllium also facilitates weight loss in overweight and obese participants. OBJECTIVES: A comprehensive review and meta-analysis assessing psyllium's impact on body weight, body mass index (BMI), and waist circumference in overweight and obese participants. DATA SOURCES: A comprehensive search was performed (Medline, Scopus, Cochrane Database) through March 21, 2022, using search terms to identify randomized, controlled, clinical studies designed to assess weight loss in overweight and obese participants over at least 2 months. Data were analyzed using the inverse variance method with random effects models. CONCLUSIONS: Six studies meeting inclusion criteria were identified (total n = 354). The meta-analysis showed that psyllium, dosed just before meals (mean dose 10.8 g/day, mean duration 4.8 months), was effective for decreasing body weight (MD = -2.1 kg [95% confidence interval [CI]: -2.6 to -1.6]; p < .001), BMI (MD = -0.8 kg/m 2 [95% CI: -1.0 to -0.6]; p < .001) and waist circumference (MD = -2.2 cm [95% CI: -2.9 to -1.4]; p < .001) in overweight and obese populations. IMPLICATIONS FOR PRACTICE: Gel-forming nonfermented psyllium fiber, dosed just before meals, is effective in facilitating weight loss in overweight and obese participants.


Asunto(s)
Psyllium , Humanos , Peso Corporal , Obesidad , Sobrepeso , Psyllium/farmacología , Psyllium/uso terapéutico , Pérdida de Peso
2.
PLoS One ; 17(10): e0266236, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36197931

RESUMEN

BACKGROUND: Significant reductions in ambient pressure subject an individual to risk of decompression illness (DCI); with incidence up to 35 per 10,000 dives. In severe cases, the central nervous system is often compromised (>80%), making DCI among the most morbid of diving related injuries. While hyperbaric specialists suggest initiating recompression therapy with either a Treatment Table 6 (TT6) or 6A (TT6A), the optimal initial recompression treatment for severe DCI is unknown. METHODS: Swine were exposed to an insult dive breathing air at 7.06 ATA (715.35 kPa) for 24 min followed by rapid decompression at a rate of 1.82 ATA/min (184.41 kPa/min). Swine that developed neurologic DCI within 1 hour of surfacing were block randomized to one of four United States Navy Treatment Tables (USN TT): TT6, TT6A-air (21% oxygen, 79% nitrogen), TT6A-nitrox (50% oxygen, 50% nitrogen), and TT6A-heliox (50% oxygen, 50% helium). The primary outcome was the mean number of spinal cord lesions, which was analyzed following cord harvest 24 hours after successful recompression treatment. Secondary outcomes included spinal cord lesion incidence and gross neurologic outcomes based on a pre- and post- modified Tarlov assessment. We compared outcomes among these four groups and between the two treatment profiles (i.e. TT6 and TT6A). RESULTS: One-hundred and forty-one swine underwent the insult dive, with 61 swine meeting inclusion criteria (43%). We found no differences in baseline characteristics among the groups. We found no significant differences in functional neurologic outcomes (p = 0.77 and 0.33), spinal cord lesion incidence (p = 0.09 and 0.07), or spinal cord lesion area (p = 0.51 and 0.17) among the four treatment groups or between the two treatment profiles, respectively. While the trends were not statistically significant, animals treated with TT6 had the lowest rates of functional deficits and the fewest spinal cord lesions. Moreover, across all animals, functional neurologic deficit had strong correlation with lesion area pathology (Logistic Regression, p < 0.01, Somers' D = 0.74). CONCLUSIONS: TT6 performed as well as the other treatment tables and is the least resource intensive. TT6 is the most appropriate initial treatment for neurologic DCI in swine, among the tables that we compared.


Asunto(s)
Enfermedad de Descompresión , Buceo , Oxigenoterapia Hiperbárica , Enfermedades de la Médula Espinal , Animales , Descompresión , Enfermedad de Descompresión/terapia , Helio , Nitrógeno , Oxígeno , Enfermedades de la Médula Espinal/terapia , Porcinos
3.
Retina ; 42(7): 1384-1391, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35271555

RESUMEN

PURPOSE: To examine the association between omega-3 polyunsaturated fatty acids, docosahexaenoic acid, and eicosapentaenoic acid and age-related macular degeneration (AMD) in the Multi-Ethnic Study of Atherosclerosis cohort. METHODS: Multi-Ethnic Study of Atherosclerosis is a multicenter, prospective cohort study designed to identify risk factors for cardiovascular disease in four ethnic groups. Six thousand eight hundred and fourteen participants of White, African American, Hispanic/Latino, and Chinese descent, aged 45-84 years, were recruited, with those found to have cardiovascular disease excluded. Our study population included all Multi-Ethnic Study of Atherosclerosis participants with baseline polyunsaturated fatty acid measurements and retinal photography at Examination 5 (n = 3,772). Fundus photographs were assessed for AMD using a standard grading protocol. Relative risk regression (log link) determined associations between polyunsaturated fatty acid levels and AMD. RESULTS: There was a significant association between increasing docosahexaenoic acid levels and increasing docosahexaenoic acid + eicosapentaenoic acid levels with reduced risk for early AMD (n = 214 participants with early AMD, of which n = 99 (46.3%) are non-White). Eicosapentaenoic acid levels alone were not significantly associated with AMD. CONCLUSION: Our analysis suggests increasing levels of docosahexaenoic acid are associated with reduced risk for early AMD in a multiethnic cohort. This represents the first racially diverse study demonstrating an association between omega-3 polyunsaturated fatty acids and AMD risk.


Asunto(s)
Aterosclerosis , Ácidos Grasos Omega-3 , Degeneración Macular , Ácidos Docosahexaenoicos , Ácido Eicosapentaenoico , Etnicidad , Humanos , Degeneración Macular/diagnóstico , Degeneración Macular/epidemiología , Estudios Prospectivos , Factores de Riesgo
4.
Sci Rep ; 12(1): 5306, 2022 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-35351910

RESUMEN

The walking pattern and comfort of a person with lower limb amputation are determined by the prosthetic foot's diverse set of mechanical characteristics. However, most design methodologies are iterative and focus on individual parameters, preventing a holistic design of prosthetic feet for a user's body size and walking preferences. Here we refined and evaluated the lower leg trajectory error (LLTE) framework, a novel quantitative and predictive design methodology that optimizes the mechanical function of a user's prosthesis to encourage gait dynamics that match their body size and desired walking pattern. Five people with unilateral below-knee amputation walked over-ground at self-selected speeds using an LLTE-optimized foot made of Nylon 6/6, their daily-use foot, and a standardized commercial energy storage and return (ESR) foot. Using the LLTE feet, target able-bodied kinematics and kinetics were replicated to within 5.2% and 13.9%, respectively, 13.5% closer than with the commercial ESR foot. Additionally, energy return and center of mass propulsion work were 46% and 34% greater compared to the other two prostheses, which could lead to reduced walking effort. Similarly, peak limb loading and flexion moment on the intact leg were reduced by an average of 13.1%, lowering risk of long-term injuries. LLTE-feet were preferred over the commercial ESR foot across all users and preferred over the daily-use feet by two participants. These results suggest that the LLTE framework could be used to design customized, high performance ESR prostheses using low-cost Nylon 6/6 material. More studies with large sample size are warranted for further verification.


Asunto(s)
Pierna , Caminata , Pie , Humanos , Diseño de Prótesis , Rango del Movimiento Articular
5.
Artículo en Inglés | MEDLINE | ID: mdl-32071052

RESUMEN

This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 µg/ml; the mean NTZ maximum concentration (Cmax) in plasma was 10.2 µg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.).


Asunto(s)
Antituberculosos/farmacocinética , Antituberculosos/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Nitrocompuestos/farmacocinética , Nitrocompuestos/uso terapéutico , Tiazoles/farmacocinética , Tiazoles/uso terapéutico , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto , Antituberculosos/efectos adversos , Femenino , Haití , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Nitrocompuestos/efectos adversos , Esputo/microbiología , Tiazoles/efectos adversos , Adulto Joven
6.
J Am Assoc Nurse Pract ; 32(1): 15-23, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31764399

RESUMEN

BACKGROUND: Treatment guidelines for chronic idiopathic constipation (CIC) recommend an "increase in fiber intake" as a first-line therapy, but most epidemiologic studies fail to support an association between a high-fiber diet and a reduced risk of constipation. Furthermore, randomized controlled clinical studies show that most isolated fibers (e.g., supplements) are not different from placebo for a laxative effect, and several may be constipating. OBJECTIVES: The objective of this review was to compare the effects of two isolated fibers, coarse wheat bran and psyllium, on stool output and stool water content in patients with CIC. This review will also address misconceptions about fiber that are perpetuated by treatment guidelines. DATA SOURCES: A comprehensive literature review was conducted with the use of the Scopus, SciFinder, and PubMed scientific databases, limited to the previous 50 years (1968-2018; latest date included, December 31, 2018). CONCLUSIONS: In patients with CIC, nonfermented gel-forming psyllium was 3.4 times more effective than insoluble wheat bran for increasing stool output. Both psyllium and coarse wheat bran increased stool water content, a stool-softening effect, but finely ground wheat bran decreased stool water content, a stool-hardening effect. IMPLICATIONS FOR PRACTICE: It is a misconception that dietary fiber and all isolated fibers provide a laxative effect in patients with CIC. Our analysis suggests that treatment guidelines for CIC should make specific evidence-based recommendations as it pertains to fiber. To do otherwise takes the risk of perpetuating myth and misunderstanding and depriving patients of an effective therapy for CIC. A generic recommendation to "increase fiber intake" is akin to a recommendation to "increase pill intake" without regard to therapeutic or adverse effects.


Asunto(s)
Estreñimiento/tratamiento farmacológico , Laxativos/farmacología , Fibras de la Dieta/farmacología , Fibras de la Dieta/uso terapéutico , Heces , Humanos , Laxativos/farmacocinética , Laxativos/uso terapéutico , Psyllium/farmacocinética , Psyllium/farmacología , Psyllium/uso terapéutico
7.
BJS Open ; 3(5): 722-732, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31592517

RESUMEN

Background: Emergency and essential surgical, obstetric and anaesthesia (SOA) care are now recognized components of universal health coverage, necessary for a functional health system. To improve surgical care at a national level, strategic planning addressing the six domains of a surgical system is needed. This paper details a process for development of a national surgical, obstetric and anaesthesia plan (NSOAP) based on the experiences of frontline providers, Ministry of Health officials, WHO leaders, and consultants. Methods: Development of a NSOAP involves eight key steps: Ministry support and ownership; situation analysis and baseline assessments; stakeholder engagement and priority setting; drafting and validation; monitoring and evaluation; costing; governance; and implementation. Drafting a NSOAP involves defining the current gaps in care, synthesizing and prioritizing solutions, and providing an implementation and monitoring plan with a projected cost for the six domains of a surgical system: infrastructure, service delivery, workforce, information management, finance and governance. Results: To date, four countries have completed NSOAPs and 23 more have committed to development. Lessons learned from these previous NSOAP processes are described in detail. Conclusion: There is global movement to address the burden of surgical disease, improving quality and access to SOA care. The development of a strategic plan to address gaps across the SOA system systematically is a critical first step to ensuring countrywide scale-up of surgical system-strengthening activities.


Antecedentes: En la actualidad, se reconoce que la atención quirúrgica, obstétrica y anestésica urgente y esencial (surgical, obstetric, and anaesthesia, SOA) es uno de los componentes de la cobertura sanitaria universal y un elemento necesario para el funcionamiento de un sistema de salud. Para mejorar la atención quirúrgica a nivel nacional, se necesita una planificación estratégica que aborde los seis dominios de un sistema quirúrgico. En este artículo, se detalla el proceso para el desarrollo de un plan nacional de cirugía, obstetricia y anestesia (national surgical, obstetric, and anaesthesia plan, NSOAP) basado en las experiencias de los principales proveedores, los funcionarios del Ministerio de Salud, los líderes de la Organización Mundial de la Salud y consultores. Métodos: El desarrollo de un NSOAP incluye ocho pasos clave: (1) apoyo y dependencia del ministerio, (2) análisis de la situación y evaluaciones de referencia, (3) compromiso de los agentes implicados y establecimiento de prioridades, (4) redacción y validación, (5) seguimiento y evaluación, (6) análisis de costes, (7) gobernanza y (8) implementación. Redactar un NSOAP implica definir los déficits actuales en la atención, sintetizar y priorizar soluciones, y proporcionar un plan de implementación y seguimiento con unos costes proyectados para los seis dominios de un sistema quirúrgico: infraestructura, prestación de servicios, personal, gestión de la información, finanzas y gobernanza. Resultados: Hasta la fecha, cuatro países han completado un NSOAP y 23 más se han comprometido con su desarrollo. Las lecciones aprendidas de estos procesos previos de NSOAP se describen con detalle. Conclusiones: Existe un movimiento global para abordar la carga de las enfermedades que precisan cirugía, mejorar la calidad y el acceso a la atención SOA. El desarrollo de un plan estratégico para la aproximación sistemáticamente los déficits en todo el sistema SOA es un primer paso crítico para garantizar la ampliación a nivel nacional de las actividades de fortalecimiento del sistema quirúrgico.


Asunto(s)
Anestesia/métodos , Servicios Médicos de Urgencia/normas , Obstetricia/organización & administración , Procedimientos Quirúrgicos Operativos/métodos , Anestesia/economía , Anestesia/normas , Atención a la Salud/economía , Atención a la Salud/organización & administración , Femenino , Implementación de Plan de Salud/métodos , Fuerza Laboral en Salud/organización & administración , Humanos , Gestión de la Información , Liderazgo , Programas Nacionales de Salud/organización & administración , Obstetricia/economía , Obstetricia/normas , Participación de los Interesados , Procedimientos Quirúrgicos Operativos/economía , Procedimientos Quirúrgicos Operativos/normas , Atención de Salud Universal , Organización Mundial de la Salud/economía , Organización Mundial de la Salud/organización & administración
8.
J Acad Nutr Diet ; 117(5): 681-682, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28449790

Asunto(s)
Psyllium , Agua
9.
Genome Med ; 9(1): 40, 2017 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-28446242

RESUMEN

BACKGROUND: The growth factor receptor network (GFRN) plays a significant role in driving key oncogenic processes. However, assessment of global GFRN activity is challenging due to complex crosstalk among GFRN components, or pathways, and the inability to study complex signaling networks in patient tumors. Here, pathway-specific genomic signatures were used to interrogate GFRN activity in breast tumors and the consequent phenotypic impact of GRFN activity patterns. METHODS: Novel pathway signatures were generated in human primary mammary epithelial cells by overexpressing key genes from GFRN pathways (HER2, IGF1R, AKT1, EGFR, KRAS (G12V), RAF1, BAD). The pathway analysis toolkit Adaptive Signature Selection and InteGratioN (ASSIGN) was used to estimate pathway activity for GFRN components in 1119 breast tumors from The Cancer Genome Atlas (TCGA) and across 55 breast cancer cell lines from the Integrative Cancer Biology Program (ICBP43). These signatures were investigated for their relationship to pro- and anti-apoptotic protein expression and drug response in breast cancer cell lines. RESULTS: Application of these signatures to breast tumor gene expression data identified two novel discrete phenotypes characterized by concordant, aberrant activation of either the HER2, IGF1R, and AKT pathways ("the survival phenotype") or the EGFR, KRAS (G12V), RAF1, and BAD pathways ("the growth phenotype"). These phenotypes described a significant amount of the variability in the total expression data across breast cancer tumors and characterized distinctive patterns in apoptosis evasion and drug response. The growth phenotype expressed lower levels of BIM and higher levels of MCL-1 proteins. Further, the growth phenotype was more sensitive to common chemotherapies and targeted therapies directed at EGFR and MEK. Alternatively, the survival phenotype was more sensitive to drugs inhibiting HER2, PI3K, AKT, and mTOR, but more resistant to chemotherapies. CONCLUSIONS: Gene expression profiling revealed a bifurcation pattern in GFRN activity represented by two discrete phenotypes. These phenotypes correlate to unique mechanisms of apoptosis and drug response and have the potential of pinpointing targetable aberration(s) for more effective breast cancer treatments.


Asunto(s)
Neoplasias de la Mama/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes Relacionados con las Neoplasias , Receptores de Factores de Crecimiento , Transducción de Señal , Neoplasias de la Mama/genética , Femenino , Perfilación de la Expresión Génica , Humanos
10.
J Am Assoc Nurse Pract ; 29(4): 216-223, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28252255

RESUMEN

BACKGROUND: Only 5% of adults consume the recommended level of dietary fiber. Fiber supplements appear to be a convenient and concentrated source of fiber, but most do not provide the health benefits associated with dietary fiber. PURPOSE: This review will summarize the physical effects of isolated fibers in small and large intestines, which drive clinically meaningful health benefits. DATA SOURCES: A comprehensive literature review was conducted (Scopus and PubMed) without limits to year of publication (latest date included: October 31, 2016). CONCLUSIONS: The physical effects of fiber in the small intestine drive metabolic health effects (e.g., cholesterol lowering, improved glycemic control), and efficacy is a function of the viscosity of gel-forming fibers (e.g., psyllium, ß-glucan). In the large intestine, fiber can provide a laxative effect if (a) it resists fermentation to remain intact throughout the large intestine, and (b) it increases percentage of water content to soften/bulk stool (e.g., wheat bran and psyllium). IMPLICATIONS FOR PRACTICE: It is important for nurse practitioners to understand the underlying mechanisms that drive specific fiber-related health benefits, and which fiber supplements have rigorous clinical data to support a recommendation. CLINICAL PEARL: For most fiber-related beneficial effects, "Fiber needs to gel to keep your patients well."


Asunto(s)
Fibras de la Dieta/uso terapéutico , Suplementos Dietéticos/normas , Metabolismo/efectos de los fármacos , Metabolismo/fisiología , Fibras de la Dieta/farmacología , Glucanos/farmacología , Glucanos/uso terapéutico , Humanos , Intestino Delgado/fisiología , Inulina/farmacología , Inulina/uso terapéutico , Psyllium/farmacología , Psyllium/uso terapéutico , beta-Glucanos/farmacocinética , beta-Glucanos/uso terapéutico
11.
J Acad Nutr Diet ; 117(2): 251-264, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27863994

RESUMEN

Enduring misconceptions about the physical effects of fiber in the gut have led to misunderstandings about the health benefits attributable to insoluble and soluble fiber. This review will focus on isolated functional fibers (eg, fiber supplements) whose effects on clinical outcomes have been readily assessed in well-controlled clinical studies. This review will also focus on three health benefits (cholesterol lowering, improved glycemic control, and normalizing stool form [constipation and diarrhea]) for which reproducible evidence of clinical efficacy has been published. In the small bowel, clinically meaningful health benefits (eg, cholesterol lowering and improved glycemic control) are highly correlated with the viscosity of soluble fibers: high viscosity fibers (eg, gel-forming fibers such as b-glucan, psyllium, and raw guar gum) exhibit a significant effect on cholesterol lowering and improved glycemic control, whereas nonviscous soluble fibers (eg, inulin, fructooligosaccharides, and wheat dextrin) and insoluble fibers (eg, wheat bran) do not provide these viscosity-dependent health benefits. In the large bowel, there are only two mechanisms that drive a laxative effect: large/coarse insoluble fiber particles (eg, wheat bran) mechanically irritate the gut mucosa stimulating water and mucous secretion, and the high water-holding capacity of gel-forming soluble fiber (eg, psyllium) resists dehydration. Both mechanisms require that the fiber resist fermentation and remain relatively intact throughout the large bowel (ie, the fiber must be present in stool), and both mechanisms lead to increased stool water content, resulting in bulky/soft/easy-to-pass stools. Soluble fermentable fibers (eg, inulin, fructooligosaccharide, and wheat dextrin) do not provide a laxative effect, and some fibers can be constipating (eg, wheat dextrin and fine/smooth insoluble wheat bran particles). When making recommendations for a fiber supplement, it is essential to recognize which fibers possess the physical characteristics required to provide a beneficial health effect, and which fiber supplements are supported by reproducible, rigorous evidence of one or more clinically meaningful health benefits.


Asunto(s)
Fibras de la Dieta/administración & dosificación , Medicina Basada en la Evidencia , Tracto Gastrointestinal/metabolismo , Glucemia/metabolismo , Colesterol/sangre , Heces/química , Galactanos/administración & dosificación , Humanos , Inulina/administración & dosificación , Laxativos/administración & dosificación , Mananos/administración & dosificación , Gomas de Plantas/administración & dosificación , Psyllium/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Viscosidad , beta-Glucanos/administración & dosificación
12.
Dig Dis Sci ; 61(11): 3140-3146, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27680987

RESUMEN

BACKGROUND: Misconceptions about the effects of dietary fiber and 'functional' fiber on stool parameters and constipation persist in the literature. METHODS: A comprehensive literature review was conducted with the use of the Scopus and PubMed scientific databases to identify and objectively assess well-controlled clinical studies that evaluated the effects of fiber on stool parameters and constipation. RESULTS: The totality of well-controlled randomized clinical studies show that, to exert a laxative effect, fiber must: (1) resist fermentation to remain intact throughout the large bowel and present in stool, and (2) significantly increase stool water content and stool output, resulting in soft/bulky/easy-to-pass stools. Poorly fermented insoluble fiber (e.g., wheat bran) remains as discreet particles which can mechanically irritate the gut mucosa, stimulating water & mucous secretion if the particles are sufficiently large/coarse. For soluble fibers, some have no effect on viscosity (e.g., inulin, wheat dextrin) while others form high viscosity gels (e.g., ß-glucan, psyllium). If the soluble fiber is readily fermented, whether non-viscous or gel-forming, it has no effect on stool output or stool water content, and has no laxative effect. In contrast, a non-fermented, gel-forming soluble fiber (e.g., psyllium) retains its gelled nature and high water-holding capacity throughout the large bowel, resulting in soft/bulky/easy-to-pass stools. CONCLUSION: When considering a recommendation for a fiber supplement regimen to treat and/or prevent constipation, it is important to consider which fibers have the physical characteristics to exert a laxative effect, and which fiber supplements have rigorous clinical evidence of a significant benefit in patients with constipation.


Asunto(s)
Estreñimiento/prevención & control , Fibras de la Dieta/uso terapéutico , Fermentación , Laxativos/uso terapéutico , Estreñimiento/tratamiento farmacológico , Dextrinas/uso terapéutico , Suplementos Dietéticos , Glucanos/uso terapéutico , Humanos , Inulina/uso terapéutico , Psyllium/uso terapéutico , beta-Glucanos/uso terapéutico
13.
Phys Rev E ; 93(3): 033205, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27078473

RESUMEN

The influence of finite relaxation times on Thomson scattering from warm dense plasmas is examined within the framework of the average-atom approximation. Presently most calculations use the collision-free Lindhard dielectric function to evaluate the free-electron contribution to the Thomson cross section. In this work, we use the Mermin dielectric function, which includes relaxation time explicitly. The relaxation time is evaluated by treating the average atom as an impurity in a uniform electron gas and depends critically on the transport cross section. The calculated relaxation rates agree well with values inferred from the Ziman formula for the static conductivity and also with rates inferred from a fit to the frequency-dependent conductivity. Transport cross sections determined by the phase-shift analysis in the average-atom potential are compared with those evaluated in the commonly used Born approximation. The Born approximation converges to the exact cross sections at high energies; however, differences that occur at low energies lead to corresponding differences in relaxation rates. The relative importance of including relaxation time when modeling x-ray Thomson scattering spectra is examined by comparing calculations of the free-electron dynamic structure function for Thomson scattering using Lindhard and Mermin dielectric functions. Applications are given to warm dense Be plasmas, with temperatures ranging from 2 to 32 eV and densities ranging from 2 to 64 g/cc.

14.
Am J Clin Nutr ; 102(6): 1604-14, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26561625

RESUMEN

BACKGROUND: A number of health benefits are associated with intake of soluble, viscous, gel-forming fibers, including reduced serum cholesterol and the attenuation of postprandial glucose excursions. OBJECTIVE: We assess the effects of psyllium, which is a soluble, gel-forming, nonfermented fiber supplement, on glycemic control in patients who were being treated for type 2 diabetes mellitus (T2DM) and in patients who were at risk of developing T2DM. DESIGN: A comprehensive search was performed of available published literature (Scopus scientific database) and clinical records stored by Procter & Gamble with the use of key search terms to identify clinical studies that assessed the glycemic effects of psyllium in nondiabetic, pre-T2DM, and T2DM patients. RESULTS: We identified 35 randomized, controlled, clinical studies that spanned 3 decades and 3 continents. These data were assessed in 8 meta-analyses. In patients with T2DM, multiweek studies (psyllium dosed before meals) showed significant improvement in both the fasting blood glucose (FBG) concentration (-37.0 mg/dL; P < 0.001) and glycated hemoglobin (HbA1c) [-0.97% (-10.6 mmol/mol); P = 0.048]. Glycemic effects were proportional to baseline FBG; no significant glucose lowering was observed in euglycemic subjects, a modest improvement was observed in subjects with pre-T2DM, and the greatest improvement was observed in subjects who were being treated for T2DM. CONCLUSIONS: These data indicate that psyllium would be an effective addition to a lifestyle-intervention program. The degree of psyllium's glycemic benefit was commensurate with the loss of glycemic control. Because the greatest effect was seen in patients who were being treated for T2DM, additional studies are needed to determine how best to incorporate psyllium into existing prevention and treatment algorithms with concomitant hypoglycemic medications.


Asunto(s)
Diabetes Mellitus Tipo 2/terapia , Medicina Basada en la Evidencia , Hiperglucemia/prevención & control , Hipoglucemia/prevención & control , Prebióticos , Estado Prediabético/dietoterapia , Psyllium/uso terapéutico , Terapia Combinada/efectos adversos , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/prevención & control , Hemoglobina Glucada/análisis , Humanos , Prebióticos/efectos adversos , Estado Prediabético/sangre , Estado Prediabético/epidemiología , Estado Prediabético/prevención & control , Psyllium/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Riesgo
15.
Nutr Metab Cardiovasc Dis ; 22(10): 877-82, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22494807

RESUMEN

AIMS: To determine if customary lower serum vitamin D concentrations in healthy African American (AA) adults are associated with modest elevations in fasting plasma glucose (FPG) and/or resting blood pressure (BP). Numerous health disparities between African American (AA) and Caucasian American (CA) adults, especially those which increase cardiovascular morbidity and mortality, have been attributed to lower serum vitamin D concentrations in the AA. Prediabetes (PreDM) and prehypertension (PreHTN) are significantly more prevalent in healthy disease free CA adults with serum vitamin D concentrations below the 75th percentile for the Caucasian cohort. We hypothesized that despite overall lower serum vitamin D concentrations in AA, an increase in the prevalence for PreDM and PreHTN would be seen in those with low vitamin D levels. METHODS AND RESULTS: Disease free AA adults in the National Health and Nutrition Examination Survey 2001-2006 were assessed. PreDM and PreHTN were diagnosed using the ADA and JNC 7 criteria: (FPG) 100-125 mg/dL and resting systolic (SBP) 120-139 and/or diastolic (DBP) 80-89 mm Hg, respectively. Logistic regression was employed to assess effects of low vitamin D concentrations on the odds for PreDM and PreHTN (n = 621). Age, gender and BMI adjusted odds ratio for co-morbid PreDM and PreHTN in AA men (n = 343) and women (n = 278) with vitamin D levels ≤45.4 versus >45.4 nmol/L was 2.02 (1.11, 3.68), (p < 0.021). CONCLUSIONS: Evaluating serum vitamin D levels, with consideration for supplementation in seemingly healthy AA adults with prediabetes, prehypertension, or co-existing prediabetes and prehypertension, has merit.


Asunto(s)
Negro o Afroamericano , Estado Prediabético/epidemiología , Prehipertensión/epidemiología , Deficiencia de Vitamina D/epidemiología , Vitamina D/sangre , Adulto , Anciano , Glucemia/análisis , Presión Sanguínea , Comorbilidad , Estudios Transversales , Suplementos Dietéticos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Estado Prediabético/sangre , Estado Prediabético/fisiopatología , Prehipertensión/sangre , Prehipertensión/fisiopatología , Prevalencia , Factores de Riesgo , Deficiencia de Vitamina D/fisiopatología , Población Blanca , Adulto Joven
16.
J Pharmacol Exp Ther ; 340(2): 445-56, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22072732

RESUMEN

Ionotropic GABA(A) receptors (GABA(A)Rs), which mediate inhibitory neurotransmission in the central nervous system, are implicated in the behavioral effects of alcohol and alcoholism. Site-directed mutagenesis studies support the presence of discrete molecular sites involved in alcohol enhancement and, more recently, inhibition of GABA(A)Rs. We used Xenopus laevis oocytes to investigate the 6' position in the second transmembrane region of GABA(A)Rs as a site influencing alcohol inhibition. We asked whether modification of the 6' position by substitution with larger residues or methanethiol labeling [using methyl methanethiosulfonate (MMTS)] of a substituted cysteine, reduced GABA action and/or blocked further inhibition by alcohols. Labeling of the 6' position in either α2 or ß2 subunits reduced responses to GABA. In addition, methanol and ethanol potentiation increased after MMTS labeling or substitution with tryptophan or methionine, consistent with elimination of an inhibitory site for these alcohols. Specific alcohols, but not the anesthetic etomidate, competed with MMTS labeling at the 6' position. We verified a role for the 6' position in previously tested α2ß2 as well as more physiologically relevant α2ß2γ2s GABA(A)Rs. Finally, we built a novel molecular model based on the invertebrate glutamate-gated chloride channel receptor, a GABA(A)R homolog, revealing that the 6' position residue faces the channel pore, and modification of this residue alters volume and polarity of the pore-facing cavity in this region. These results indicate that the 6' positions in both α2 and ß2 GABA(A)R subunits mediate inhibition by short-chain alcohols, which is consistent with the presence of multiple counteracting sites of action for alcohols on ligand-gated ion channels.


Asunto(s)
Etanol/farmacología , Antagonistas de Receptores de GABA-A/farmacología , Receptores de GABA-A/efectos de los fármacos , Alcoholes/metabolismo , Alcoholes/farmacología , Sustitución de Aminoácidos/fisiología , Animales , Sitios de Unión/fisiología , Unión Competitiva , Cisteína/genética , Cisteína/metabolismo , Cistina/metabolismo , ADN Complementario/genética , Sinergismo Farmacológico , Fenómenos Electrofisiológicos/efectos de los fármacos , Fenómenos Electrofisiológicos/fisiología , Etanol/metabolismo , Etomidato/farmacología , Antagonistas de Receptores de GABA-A/metabolismo , Humanos , Metionina/genética , Metilmetanosulfonato/análogos & derivados , Metilmetanosulfonato/metabolismo , Metilmetanosulfonato/farmacología , Simulación de Dinámica Molecular , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Técnicas de Placa-Clamp , Receptores de GABA-A/química , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , Triptófano/genética , Xenopus laevis , Ácido gamma-Aminobutírico/farmacología
17.
Food Chem Toxicol ; 49(12): 3319-27, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21939727

RESUMEN

To characterize the subchronic oral toxicity of resveratrol, CD rats received daily gavage doses of 0, 200, 400, or 1000 mg resveratrol/kg/day, and beagle dogs received daily capsule doses of 0, 200, 600, or 1200 mg resveratrol/kg/day for 90 days. Resveratrol induced only minimal toxicity, consisting of dose-related reductions in body weight gain in female rats and both sexes of dogs, and a statistically significant increase in bilirubin levels in rats at the 1000 mg/kg/day dose. Clinical observations, hematology, ophthalmology, neurotoxicity evaluations (functional observational batteries), organ weights, and gross pathology provided no biologically significant evidence of resveratrol toxicity in either species. In rats, the high dose of resveratrol reduced the incidence of cardiomyopathy; no other microscopic changes were seen. Histopathologic changes in dogs were limited to minimal inflammatory infiltrates in the kidney and urinary bladder, which were not considered toxicologically significant. A cardiovascular safety pharmacology (telemetry) study in dogs revealed no evidence of resveratrol toxicity. Based on body weight effects, the No Observed Adverse Effect Level (NOAEL) for resveratrol was 200mg/kg/day in rats and 600 mg/kg/day in dogs. The apparent cardioprotective activity of resveratrol in rats demonstrates that its potentially beneficial activities may extend beyond efficacy in cancer prevention.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Cardiotónicos/farmacología , Polifenoles/farmacología , Estilbenos/toxicidad , Pruebas de Toxicidad Subcrónica/métodos , Administración Oral , Animales , Peso Corporal/efectos de los fármacos , Perros , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Femenino , Riñón/efectos de los fármacos , Riñón/metabolismo , Masculino , Nivel sin Efectos Adversos Observados , Tamaño de los Órganos/efectos de los fármacos , Ratas , Resveratrol , Estilbenos/administración & dosificación , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo
18.
Artículo en Inglés | MEDLINE | ID: mdl-22256157

RESUMEN

A mechanical Lower Limb Paralysis Simulator (LLPS) was developed for able-bodied persons to model the gait of Reciprocating Gait Orthosis (RGO) users. The purpose of this study was to determine if able-bodied subjects ambulating with the LLPS exhibited gait characteristics typical of RGO users. Five able-bodied persons were trained to ambulate with the LLPS and underwent a motion gait analysis. LLPS users were found to exhibit gait patterns that were characteristic of RGO-assisted gait.


Asunto(s)
Terapia por Estimulación Eléctrica/instrumentación , Modelos Biológicos , Aparatos Ortopédicos , Paraplejía/fisiopatología , Paraplejía/terapia , Caminata/fisiología , Humanos
19.
Am J Clin Nutr ; 92(5): 1204-13, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20826628

RESUMEN

BACKGROUND: The relation between dietary fish intake and brachial artery measures, including brachial artery flow-mediated dilation (FMD), has not been well established across sex and racial-ethnic groups. OBJECTIVE: We hypothesized that consumption of nonfried fish and plasma phospholipid measures of long-chain omega-3 (n-3) fatty acids would be positively associated with larger FMD in men and women across racial-ethnic groups. DESIGN: We investigated cross-sectional associations of brachial artery measures with fish intake (ascertained with a food-frequency questionnaire) and plasma phospholipid omega-3 concentrations in 3045 adults, aged 45-84 y, who were free of clinical cardiovascular disease. RESULTS: In overall multivariate-adjusted analyses, there were no significant associations between fish intake or any brachial artery measures. However, when stratified by sex, there was an association between the highest quartile of nonfried fish consumption and a 0.10-mm lower (1 SD) brachial artery diameter in men (P = 0.01) and a 0.27% smaller FMD in women (P = 0.02) compared with the lowest quartile of nonfried fish intake in each respective sex strata. When stratified by race-ethnicity and race-ethnicity by sex, additional heterogeneity was noted, but results were difficult to interpret because of small sample sizes. Plasma phospholipid omega-3 concentrations showed a similar directionality of association with brachial artery measures observed for nonfried fish consumption, although statistical significance was not achieved in fully adjusted models. CONCLUSION: This study indicates that the association between nonfried fish intake and baseline brachial artery size varies by sex, with suggestive evidence of sex differences in the association between nonfried fish intake and FMD.


Asunto(s)
Grasas de la Dieta/administración & dosificación , Ácidos Grasos Omega-3/farmacología , Peces , Fosfolípidos/química , Alimentos Marinos , Vasodilatación/efectos de los fármacos , Animales , Aterosclerosis/prevención & control , Arteria Braquial/fisiología , Estudios Transversales , Etnicidad , Ácidos Grasos Omega-3/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Fosfolípidos/sangre , Factores Sexuales
20.
Food Chem Toxicol ; 46(3): 1068-78, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18082924

RESUMEN

Se-methylselenocysteine (MSC) is an organoselenium compound being developed for breast cancer chemoprevention. To characterize MSC toxicity, CD rats received daily gavage doses of 0, 0.5, 1.0, or 2.0 mg/kg/day (0, 3, 6, or 12 mg/m(2)/day), and beagle dogs received daily gavage doses of 0, 0.15, 0.3, or 0.6 mg/kg/day (0, 3, 6, or 12 mg/m(2)/day) for 28 days. In rats, MSC induced dose-related hepatomegaly in both sexes; mild anemia, thrombocytopenia, and elevated liver enzymes were observed in high dose females only. Microscopic pathology included hepatocellular degeneration (high dose males, all doses in females); arrested spermatogenesis (high dose males); and atrophy of corpora lutea (middle and high dose females). In dogs, MSC induced mild anemia in middle and high dose males, and in high dose females. Toxicologically significant microscopic lesions in dogs were seen only in the liver (peliosis and vacuolar degeneration in high dose males, midzonal necrosis in males in all dose groups). Based on liver pathology seen in female rats in all dose groups, the no observed adverse effect level (NOAEL) for MSC in rats is <0.5mg/kg/day. Based on alterations in hematology parameters and liver morphology in male dogs in all dose groups, the NOAEL for MSC in dogs is <0.15 mg/kg/day.


Asunto(s)
Anticarcinógenos/toxicidad , Neoplasias de la Mama/prevención & control , Cisteína/análogos & derivados , Compuestos de Organoselenio/toxicidad , Administración Oral , Animales , Anticarcinógenos/administración & dosificación , Cisteína/administración & dosificación , Cisteína/toxicidad , Perros , Femenino , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Compuestos de Organoselenio/administración & dosificación , Ratas , Selenocisteína/análogos & derivados
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