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1.
Carbohydr Polym ; 189: 48-55, 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29580425

RESUMEN

Environmental concerns have led to extensive research for replacing polymer-based food packaging with bio-nano-composites. In this study, incorporation of nano-cellulose into gelatin and starch matrices is investigated for this purpose. Chitosan is used to improve mechanical, anti-fungal and waterproof properties. Experiments are designed and analyzed using response surface methodology. Nano-Cellulose is synthesized via acid hydrolysis and incorporated in base matrices through wet processing. Also, tensile strength test, food preservation, transparency in visible and UV and water contact angle are performed on the nano-composite films. DSC/TGA and air permeability tests are also performed on the optimal films. The results show that increasing nano-cellulose composition to 10% leads to increase the tensile strength at break to 8121 MN/m2 and decrease the elongation at break. Also, increasing chitosan composition from 5% to 30% can enhance food preservation up to 15 days.


Asunto(s)
Celulosa/química , Quitosano/química , Embalaje de Alimentos , Gelatina/química , Nanocompuestos/química , Almidón/química , Resistencia a la Tracción
2.
Proc Natl Acad Sci U S A ; 110(2): 660-5, 2013 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-23269839

RESUMEN

Airway obstruction is a hallmark of allergic asthma and is caused primarily by airway smooth muscle (ASM) hypercontractility. Airway inflammation leads to the release of cytokines that enhance ASM contraction by increasing ras homolog gene family, member A (RhoA) activity. The protective mechanisms that prevent or attenuate the increase in RhoA activity have not been well studied. Here, we report that mice lacking the gene that encodes the protein Milk Fat Globule-EGF factor 8 (Mfge8(-/-)) develop exaggerated airway hyperresponsiveness in experimental models of asthma. Mfge8(-/-) ASM had enhanced contraction after treatment with IL-13, IL-17A, or TNF-α. Recombinant Mfge8 reduced contraction in murine and human ASM treated with IL-13. Mfge8 inhibited IL-13-induced NF-κB activation and induction of RhoA. Mfge8 also inhibited rapid activation of RhoA, an effect that was eliminated by an inactivating point mutation in the RGD integrin-binding site in recombinant Mfge8. Human subjects with asthma had decreased Mfge8 expression in airway biopsies compared with healthy controls. These data indicate that Mfge8 binding to integrin receptors on ASM opposes the effect of allergic inflammation on RhoA activity and identify a pathway for specific inhibition of ASM hypercontractility in asthma.


Asunto(s)
Antígenos de Superficie/metabolismo , Asma/fisiopatología , Hiperreactividad Bronquial/fisiopatología , Proteínas de la Leche/metabolismo , Contracción Muscular/fisiología , Músculo Liso/fisiología , Análisis de Varianza , Animales , Antígenos de Superficie/genética , Western Blotting , Lavado Broncoalveolar , Calcio/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Humanos , Interleucina-13/farmacología , Pulmón/patología , Ratones , Ratones Noqueados , Proteínas de la Leche/genética , FN-kappa B/metabolismo , Mutación Puntual/genética , Proteínas de Unión al GTP rho/metabolismo , Proteína de Unión al GTP rhoA
4.
Acta Diabetol ; 50(5): 807-14, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21773756

RESUMEN

While it is known that islet cell mass increases considerably after birth, general uncertainty surrounds the source of new beta cells in humans. Chronic pancreatitis (CP) presents a natural injury model for studying postnatal beta-cell regeneration in the human pancreas. In this report, we present histological evidence from human CP pancreases to support the theory that islet neogenesis can occur from ductal precursor cells after birth. Three young patients (ages 16, 12, and 28 years) underwent total pancreatectomy for the management of CP followed by islet isolation and autologous transplantation to prevent or minimize postsurgical diabetes. In all cases, the pancreases had extensive fibrosis, a rock-like consistency, and calcifications in the ducts. During islet isolations, we observed the unusual release of islets with many ductal fragments. In histopathological evaluation of these pancreases, solid cords of cells sometimes formed islet like structures intraductally or extending from ductal structures. Immunofluorescence staining for chromogranin, insulin, proinsulin, PDX1, glucagon, and cytokeratins confirmed these structures to be composed of chromogranin-positive endocrine cells which included both ß-cells and α-cells. Labeling for Ki67 to demonstrate mitotic activity showed frequent labeling of duct epithelial cells and of some periductal cells. Using insulin and wide-spectrum cytokeratin double immunofluorescent labeling, we found insulin-positive cells to be present within the ductal lumens, among the cytokeratin-positive ductal epithelium, and extending from the ductal epithelium into surrounding connective tissues, providing evidence for a ductal origin of islet neogenesis.


Asunto(s)
Islotes Pancreáticos/embriología , Páncreas/patología , Conductos Pancreáticos/citología , Pancreatitis Crónica/patología , Adolescente , Adulto , Niño , Femenino , Fibrosis , Humanos , Islotes Pancreáticos/citología , Masculino , Páncreas/cirugía , Pancreatectomía , Pancreatitis Crónica/cirugía , Índice de Severidad de la Enfermedad
5.
Asian Pac J Cancer Prev ; 13(8): 3927-30, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23098494

RESUMEN

Breast cancer is the most common cancer in women worldwide and the leading cause of death from cancer among women. Evidence suggests that early diagnosis and screening interventions might help to improve outcomes. This population-based study was conducted to determine breast cancer awareness and screening behavior among Iranian women and to examine its association with women's literacy. The study was carried out in two provinces, with 1,477,045 population, located in central and eastern part of Iran. Overall, 770 women were studied. Of these, 482 (62.7%) were literate and 287 (37.3%) were not. The results obtained from the data analysis indicated that there was a significant difference between literate and illiterate women. Further analysis of the data using logistic regression showed that literacy was an important contributing factor for breast cancer prevention behavior. The findings suggest that in order to improve women's health and breast cancer outcomes providing equal educational opportunities for women seems necessary.


Asunto(s)
Neoplasias de la Mama/prevención & control , Autoexamen de Mamas/estadística & datos numéricos , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Alfabetización en Salud , Adulto , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/epidemiología , Autoexamen de Mamas/tendencias , Estudios Transversales , Femenino , Humanos , Irán/epidemiología , Persona de Mediana Edad , Pronóstico , Encuestas y Cuestionarios
6.
East Mediterr Health J ; 17(6): 523-8, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21796971

RESUMEN

A study in Monastir, Tunisia estimated the prevalence of smoking and analysed the determinants of tobacco use among adolescents aged 10-19 years. An observational cross-sectional study was performed in the 8 colleges and high schools of Monastir city in 2004. The mean age of the 900 respondents was 15.8 (SD 2.2) years and 47.7% were aged under 16 years. The overall prevalence of cigarette use during the past year was 16.0% (30.2% among males and 4.6% among females). The first smoking experience was initiated by friends in 45.8% of cases, at a mean age of 13.8 (SD 2.3) years. One-fifth of smokers (21.5%) had used other forms of tobacco. In multivariate analysis, male sex, academic failure, poor family management, antisocial behaviour and addictive behaviour were the main predictors of adolescent smoking status. The prevalence of smoking among adolescents in Monastir is high and requires targeted action.


Asunto(s)
Fumar/epidemiología , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Análisis Multivariante , Prevalencia , Factores de Riesgo , Encuestas y Cuestionarios , Túnez/epidemiología , Adulto Joven
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