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BACKGROUND: Currently, weight loss remains the main management strategy for NAFLD, but the weight loss intention and methods remain poorly characterized. METHODS: We analysed data about the perception of weight status, intention and methods to lose weight amongst 3,822 persons with NAFLD (United States Fatty Liver Index ≥ 30) from the National Health and Nutrition Examination Survey, 2001-2014. RESULTS: Only 53.9% of people with NAFLD intended to lose weight, 91.8% with perception of overweight and 8.2% with normal weight perception. Persons with perception of overweight or overweight/obese status were four times more likely to try to lose weight (adjusted odds ratios 3.9 and 4.2, respectively, both P < 0.0001). Younger age, women, higher educational level, Hispanic and blacks (versus whites) were significant independent factors associated with weight loss intention. Notably, ≤10% attended weight loss programme. Metabolic equivalent of task hours per week was significantly higher in whites who exercised to lose weight (vs. no exercise, P = 0.003) but not in other racial/ethnic groups. Interestingly, calorie intake was similar between those who dieted versus not (2056 vs. 1970 kcal/day, P = 0.11). About 30% reported ≥ 10-lb weight loss, with 50% higher odds of success for men but there was no difference by race/ethnicity. CONCLUSION: Overweight or obese perception was a key driver in weight loss activities but was inconsistent with actual weight status and varied by race/ethnicity and other sociodemographic factors. Weight loss programme is under-utilized and should take in account of weight perception training and culturally appropriate approach.
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Imagen Corporal , Intención , Enfermedad del Hígado Graso no Alcohólico , Pérdida de Peso , Índice de Masa Corporal , Femenino , Humanos , Masculino , Encuestas Nutricionales , Obesidad/terapia , Sobrepeso/terapia , Factores Sociodemográficos , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Updated prevalence and outcome data for nonobese NAFLD for the multi-ethnic US population is limited. OBJECTIVES: We aimed to investigate the prevalence, clinical characteristics and mortality of obese and nonobese individuals with NAFLD in the United Sates. METHODS: A retrospective study was conducted using the 1999-2016 NHANES databases. We determined hazard ratio stratified by obesity status in NAFLD individuals using Cox regression and log-rank test. RESULTS: Overall NAFLD prevalence was 32.3%: 22.7% were obese and 9.6% were nonobese, with increasing trend over time for obese NAFLD, but not nonobese NAFLD. Amongst those with NAFLD, 29.7% (95% CI: 27.8%-31.7%) were nonobese, of which 13.6% had lean NAFLD. Nonobese NAFLD was more common in older (40.9% if ≥ 65 vs. 24.2% if < 65 years), male (34.0% vs. 24.2%) and foreign-born Asian people (39.8% vs. 11.4%) and uncommon in black (11.5% vs 30-35% in other ethnicities, P < 0.001). Metabolic comorbidities were common in nonobese NAFLD individuals who also had more advanced fibrosis. Nonobese NAFLD individuals had higher 15-year cumulative all-cause mortality (51.7%) than obese NAFLD (27.2%) and non-NAFLD (20.7%) (P < 0.001). However, DM and fibrosis, but neither obese nor nonobese NAFLD compared to non-NAFLD was independently associated with higher mortality. CONCLUSION: Nonobese NAFLD makes up about one-third of the NAFLD in the United States (even higher in older, male and foreign-born individuals) and carries higher mortality than obese NAFLD. Screening for NAFLD should be considered in high-risk groups even in the absence of obesity.
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Enfermedad del Hígado Graso no Alcohólico/epidemiología , Obesidad/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Diabetes Mellitus/epidemiología , Femenino , Humanos , Cirrosis Hepática/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Grupos Raciales/estadística & datos numéricos , Estudios Retrospectivos , Distribución por Sexo , Estados Unidos/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a rising global disease associated with clinical and economic burdens. OBJECTIVES: We aimed to quantify NAFLD prevalence and awareness to provide stakeholders necessary information to combat NAFLD burden. METHODS: This study utilizes data from the National Health and Nutrition Examination Survey 2011-2016 and included 4538 adult participants who did not have heavy drinking or viral hepatitis history. The US fatty liver index defined NAFLD and NAFLD fibrosis score defined fibrosis. NAFLD awareness was captured by questionnaire. RESULTS: Amongst the study population of 4538 persons, NAFLD prevalence was 32.5%, lowest in non-Hispanic Blacks (18.0%) and Asians (18.1%), highest amongst Mexican Americans (48.4%). Within the NAFLD group, advanced fibrosis was highest in non-Hispanic Blacks (28.5%) and lowest amongst non-Hispanic Asians (2.7%). Of the 1473 (97.5%) NAFLD participants who answered NAFLD awareness question, 90% visited a healthcare centre at least once in the past year, but only 5.1% were aware of having NAFLD. On weighted population estimates, 77.33 million persons had NAFLD, 17.63 million had advanced fibrosis, and 73.39 million NAFLD participants were not aware of having NAFLD. CONCLUSIONS: Of 77.33 million people in the United States have NAFLD with 17.63 million having advanced fibrosis, with lowest prevalence in non-Hispanic Asians and highest in Mexican Americans. A conundrum exists amongst non-Hispanic Blacks who have low NAFLD prevalence but highest prevalence of advanced fibrosis. Awareness of NAFLD was low across all ethnicities. Effort is needed to improve disease awareness whilst addressing NAFLD clinical burden across ethnicities.
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Etnicidad/estadística & datos numéricos , Conocimientos, Actitudes y Práctica en Salud , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Grupos Raciales/estadística & datos numéricos , Adulto , Negro o Afroamericano/psicología , Negro o Afroamericano/estadística & datos numéricos , Alcoholismo/complicaciones , Alcoholismo/epidemiología , Alcoholismo/psicología , Asiático/psicología , Asiático/estadística & datos numéricos , Etnicidad/psicología , Femenino , Hepatitis Viral Humana/complicaciones , Hepatitis Viral Humana/epidemiología , Hepatitis Viral Humana/psicología , Hispánicos o Latinos/psicología , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , Americanos Mexicanos/psicología , Americanos Mexicanos/estadística & datos numéricos , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/psicología , Encuestas Nutricionales , Prevalencia , Grupos Raciales/psicología , Encuestas y Cuestionarios , Estados Unidos/epidemiología , Población Blanca/psicología , Población Blanca/estadística & datos numéricos , Adulto JovenRESUMEN
BACKGROUND: Direct-acting antiviral (DAA) regimens have shown high efficacy and tolerability for patients with HCV genotype 1/1b (GT1/1b) in clinical trials. However, robust real-world evidence of interferon (IFN)-free DAA treatment for HCV GT1-infected patients in Asia is still lacking. AIM: To systematically review and meta-analyse the effectiveness and tolerability of IFN-free DAA therapy for HCV GT1 infection in Asia. METHODS: We included studies that enrolled adult patients with HCV GT1 infection in routine clinical practice in Asia, using IFN-free DAA regimens, and reported sustained virological response (SVR) after 12/24 weeks end-of-treatment by 31 May 2017. The pooled SVR rates were computed with a random-effects model. Subgroup analysis and meta-regression as previously registered in PROSPERO were performed to determine how pre-planned variables might have affected the pooled estimates. RESULTS: We included 41 studies from eight countries and regions, comprising of 8574 individuals. The pooled SVR rates for GT1 were 89.9% (95% CI 88.6-91.1, I2 = 55.1%) with daclatasvir/asunaprevir (DCV/ASV) and 98.1% (95% CI 97.0-99.0, I2 = 41.0%) with ledipasvir/sofosbuvir ± ribavirin (LDV/SOF ± RBV). Baseline cirrhosis but not prior treatment history and age, attenuated the effectiveness of both regimens. Baseline resistance associated substitutions (RASs) severely attenuated SVR of DCV/ASV (65.4% vs 94.3%, P < 0.001) and only minimally with LDV/SOF ± RBV (94.5% vs 99.2%, P = 0.003). Patients with renal dysfunction treated with DCV/ASV showed a higher SVR rate (93.9% vs 89.8%, P = 0.046). Patients with hepatocellular carcinoma (HCC) LDV/SOF ± RBV achieved a lower SVR than those without HCC (94.1% vs 98.7%, P = 0.001). CONCLUSION: All oral DAA treatment of HCV GT1 resulted in high cure rates in Asian patients in routine clinical practice setting including elderly patients and those with end-stage renal disease.
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Antivirales/uso terapéutico , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Adulto , Asia/epidemiología , Quimioterapia Combinada/efectos adversos , Medicina General/estadística & datos numéricos , Genotipo , Hepatitis C Crónica/epidemiología , Hepatitis C Crónica/virología , Humanos , Resultado del TratamientoRESUMEN
Acral pseudolymphomatous angiokeratoma of children (APACHE) is a rare form of cutaneous pseudolymphoma characterized byangiomatous papules with a predilection for the acral regions of children. Classically, a dense dermal lymphocytic infiltrate composed of both T and B cells is seen in histological specimens, together with prominent vessels lined by plump endothelial cells. Increasing evidence suggests that this condition is neither necessarily acral, pseudolymphomatous, nor angiokeratomatous. It may not always be a pediatric disease. Therefore, the correctness of its nomenclature has been questioned. Herein, we report threecases whose clinical and histological features were consistent with the diagnosis of APACHE. To our knowledge, this is the first report of APACHE from Southeast Asia. We also discuss why we believe "APACHE" to be a misnomer and support "papular angiolymphoid hyperplasia" as a more accurate and encompassing term. In addition, we illustrate a case with significant overlapping features with lymphoplasmacytic plaque in children, suggesting that both entities may exist on a clinical andhistological spectrum.
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Angioqueratoma/patología , Hiperplasia Angiolinfoide con Eosinofilia/patología , Seudolinfoma/patología , Neoplasias Cutáneas/patología , Niño , Femenino , Humanos , Masculino , Singapur , Enfermedades de la Piel/patología , Terminología como Asunto , Adulto JovenRESUMEN
We intercalate a van der Waals heterostructure of graphene and hexagonal boron nitride with Au, by encapsulation, and show that the Au at the interface is two dimensional. Charge transfer upon current annealing indicates the redistribution of the Au and induces splitting of the graphene band structure. The effect of an in-plane magnetic field confirms that the splitting is due to spin splitting and that the spin polarization is in the plane, characteristic of a Rashba interaction with a magnitude of approximately 25 meV. Consistent with the presence of an intrinsic interfacial electric field we show that the splitting can be enhanced by an applied displacement field in dual gated samples. A giant negative magnetoresistance, up to 75%, and a field induced anomalous Hall effect at magnetic fields <1 T are observed. These demonstrate that the hybridized Au has a magnetic moment and suggests the proximity to the formation of a collective magnetic phase. These effects persist close to room temperature.
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The development of spintronics devices relies on efficient generation of spin-polarized currents and their electric-field-controlled manipulation. While observation of exceptionally long spin relaxation lengths makes graphene an intriguing material for spintronics studies, electric field modulation of spin currents is almost impossible due to negligible intrinsic spin-orbit coupling of graphene. In this work, we create an artificial interface between monolayer graphene and few-layer semiconducting tungsten disulphide. In these devices, we observe that graphene acquires spin-orbit coupling up to 17 meV, three orders of magnitude higher than its intrinsic value, without modifying the structure of the graphene. The proximity spin-orbit coupling leads to the spin Hall effect even at room temperature, and opens the door to spin field effect transistors. We show that intrinsic defects in tungsten disulphide play an important role in this proximity effect and that graphene can act as a probe to detect defects in semiconducting surfaces.
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The Ministry of Health (MOH) has updated the clinical practice guidelines on Dementia to provide doctors and patients in Singapore with evidence-based treatment for dementia. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Dementia, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical/2013/cpgmed_dementia_revised.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.
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Demencia/diagnóstico , Demencia/terapia , Guías de Práctica Clínica como Asunto , Salud Pública/normas , Medicina Basada en la Evidencia , Geriatría/métodos , Humanos , Atención Primaria de Salud/métodos , Atención Primaria de Salud/normas , SingapurRESUMEN
Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via prestructural ordering (incubation) effects. A crystallization speed of 500 picoseconds was achieved, as well as high-speed reversible switching using 500-picosecond pulses. Ab initio molecular dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystallization speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.
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BACKGROUND AND AIMS: Angio-embolisation in trauma is a relatively new technique that is gaining popularity and recognition in identifying and arresting bleeding in trauma patients. We studied the possibility whether angio-embolisation using the Digital Subtraction Angiography (DSA), in the operating theatre (OT) could achieve successful haemostasis in trauma patients. We further studied the feasibility of using this technique as part of trauma resuscitation/damage control. METHODS: A retrospective study of trauma patients, with Injury Severity Score (ISS ≥ 9), admitted to Tan Tock Seng Hospital (TTSH) from January 2004 to December 2008 was done. Patients who had received angio-embolisation in the OT or angiography suite were evaluated in terms of age, gender, ISS, the site and type of angioembolisation used. The primary end point was to assess the success rate of angioembolisation using the C-Arm DSA in the OT, and whether there were any complications necessitating a repeat procedure or surgical intervention. The secondary end points of the study were aimed at studying the cost effectiveness of this technique, logistical feasibility and evaluating this technique as part of the initial trauma resuscitative efforts. RESULTS: A total of 43 trauma patients received angioembolisation. 32 patients had the angio-embolisation done using the C-Arm DSA in the OT (n = 32). None of the patients who received angioembolisation in the operating theatre (n = 32) had any re-bleeding. 15 out of 32 survived. There were no complications related to the angio-embolisation procedure. The majority of angio-embolisations done were for pelvic fractures. CONCLUSION: The success of angio-embolisation in the OT using the C-Arm DSA for a trauma patient and its complication rates are similar to that done in a dedicated angio-graphic suite. We conclude that angio-embolisation in the operating theatre using the C-Arm DSA is feasible, cost effective and can be a modality in the initial trauma resuscitation/damage control in any lead lined operating theatre. We believe that we are the first to describe this method of angio-embolisation using the C-Arm DSA in a conventional lead lined trauma operating theatre and its use as a feasible option in a trauma resuscitation/damage control algorithm.
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Angiografía de Substracción Digital/métodos , Embolización Terapéutica/métodos , Hemorragia/diagnóstico por imagen , Adolescente , Adulto , Niño , Preescolar , Análisis Costo-Beneficio , Medicina de Emergencia , Estudios de Factibilidad , Femenino , Hemorragia/terapia , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Valor Predictivo de las Pruebas , Resucitación , Estudios Retrospectivos , Singapur , Adulto JovenRESUMEN
INTRODUCTION: The elderly population in Singapore is steadily increasing, thus increasing the stress on healthcare provision and financing. Elderly injuries result in significant mortality and morbidity. This study aimed to identify the injury patterns, specific risk factors involved and needs of the elderly so that the current emergency model of care for the injured elderly can be improved and injury prevention strategies devised. METHODS: We conducted a retrospective study of all elderly aged 65 years and older seen for trauma in an emergency department over six months. Data captured in the real-time computer system was studied with regard to patient profile, mechanism of injury and patient disposition. RESULTS: 720 patients aged 65 years and older were seen for trauma in the first six months of 2005, accounting for 10.4 percent of the total attendance for that age group. Home injuries (67.9 percent) were the most common, followed by road-related injuries (21.2 percent). 85.3 percent of the injuries were due to falls. 49.9 percent of the patients were admitted to hospital. We also examined the underlying causes of the injuries and the common injuries sustained. CONCLUSION: Injuries in the elderly is a significant problem. Most of the injuries occur at home and falling is the commonest cause. Many of the injuries are potentially preventable. Several possible injury prevention strategies and improvements to the current emergency model of care of the injured elderly are discussed. The establishment of a national elderly injury surveillance database is advocated.
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Accidentes por Caídas/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Anciano , Anciano de 80 o más Años , Femenino , Evaluación Geriátrica , Humanos , Masculino , Médicos de Familia , Vigilancia de la Población , Estudios Retrospectivos , Factores de Riesgo , Singapur/epidemiologíaRESUMEN
Bladder cancer is the fifth most common malignancy in the UK. Clinically, the most important process in determining prognosis is the development of invasion, initially of the lamina propria and then beyond as these transitional cell carcinomas (TCCs) progress from stage pT1 to stages T2+. Cadherins and catenins are the main mediators of cell-cell interactions in epithelial tissues, and loss of membranous E-cadherin immunoreactivity is strongly correlated with high grade, advanced stage and poor prognosis in bladder cancer and other malignancies. However, the role of P-cadherin is yet to be fully elucidated in bladder TCC. The objectives of this study were to establish how the expression of cadherins and catenins determines clinical and in vitro behaviour in bladder TCC. Utilizing immunohistochemistry, immunofluorescence and western blotting, we demonstrated a significant reduction in the expression of E-cadherin and beta-catenin as grade and stage of bladder TCC progress, accompanied by a significant increase in P-cadherin expression (all p < 0.05, Pearson's chi2 test). Increased P-cadherin expression was also associated with a significantly worse bladder cancer-specific survival (log rank p = 0.008), with Cox regression showing P-cadherin to be an independent prognostic factor. Utilizing a variety of tissue culture models in a range of functional studies, we demonstrated that P-cadherin mediates defective cell-cell adhesion and enhances anchorage-independent growth. The results provide evidence that increased P-cadherin expression promotes a more malignant and invasive phenotype of bladder cancer, and appears to have a novel role late in the disease.
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Biomarcadores de Tumor/análisis , Cadherinas/metabolismo , Carcinoma de Células Transicionales/metabolismo , Cateninas/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Western Blotting/métodos , Cadherinas/análisis , Carcinoma de Células Transicionales/química , Carcinoma de Células Transicionales/patología , Cateninas/análisis , Humanos , Inmunohistoquímica , Pronóstico , Modelos de Riesgos Proporcionales , Análisis de Supervivencia , Neoplasias de la Vejiga Urinaria/química , Neoplasias de la Vejiga Urinaria/patología , beta Catenina/análisisRESUMEN
BACKGROUND: Fine-needle aspiration cytology (FNAC) is integral to the diagnosis and management of patients with thyroid nodules. We introduced synoptic cytology reporting for thyroid nodules in 2004. The aim of this study was to examine the effect of synoptic cytology reporting in our institution. METHODS: A comparative study of two 2-year periods (1 August 2002 to 1 August 2004 and 2 August 2004 to 2 August 2006) before and after the introduction of synoptic reporting was conducted from a prospectively collected database of patients presented with thyroid nodules. The only change during these periods was the format of FNAC reporting. We used the same radiological practice and cytopathology service throughout the study period. All patients are still being followed up. RESULTS: There were a total of 660 patients. Of these, 376 were operated and 284 non-operated. The female to male ratio was 7:1. Comparing the two periods, the overall FNAC sensitivities were 60% versus 79.1%; specificities, 83.7% versus 79.4%; accuracy, 76% versus 79.3%; false-positive result, 16.3% versus 20.6% and false-negative result, 40% versus 20.9%. The non-diagnostic rates were 7.4% versus 3.15%. FNAC prompted surgery in 66.7% versus 100% in carcinoma and 56.4% versus 73.6% in adenoma. A benign FNAC prompted surgery in 15% versus 19.8% of cases. There was no thyroid cancer detected in the current follow up. CONCLUSIONS: Synoptic cytology reporting has resulted in an overall improvement in all measures of the tests. It is a simple and effective tool to use. Synoptic cytology reporting is therefore recommended for all endocrine surgical units.
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Glándula Tiroides/patología , Nódulo Tiroideo/patología , Biopsia con Aguja Fina , Reacciones Falso Negativas , Reacciones Falso Positivas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/cirugía , Nódulo Tiroideo/cirugía , TiroidectomíaRESUMEN
In a membrane bioreactor (MBR) process containing a variety of bacteria, the bacterial adhesion to the membrane surface, prior to cake formation, causes an increased filtration resistance. In this study, Pseudomonas fluorescens, commonly found in the municipal wastewater treatment process with activated sludge, was used to show the effects of extracellular polymeric substances (EPS) on bacterial adhesion to the membrane surface in the MBR. Of the various roles of EPS in promoting membrane fouling, the adhesion of bacteria to the membrane surface was calculated using the specific cake resistance (alpha, m/kg). Although the amount of EPS binding with bacteria was increased by the addition of Ca2+, there was no significant effect on the bacterial growth. The results of the particle size distribution showed that the addition of Ca2+ increased flocculation, allowing the formation of a complex with the bacteria and EPS. In order to identify the effects of the addition of Ca2+ on the hydrophobicity, the contact angle was also measured. The result showed that the addition of Ca2+ showed no significant differences in the hydrophobicity, even though there was an increase in flocculation. With the bacteria containing a higher EPS concentration, a higher specific cake resistance was observed. From the results of the adhesion experiment, which was conducted with various EPS levels, displayed as the COD and TOC concentration, an increased EPS concentration was shown to promote bacterial adhesion to the membrane surface.
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Adhesión Bacteriana , Biopolímeros/química , Reactores Biológicos/microbiología , Pseudomonas fluorescens/fisiología , Eliminación de Residuos Líquidos , Calcio , Aguas del Alcantarillado/química , Aguas del Alcantarillado/microbiologíaRESUMEN
AIM: To examine the histological and immunocytochemical characteristics of epiretinal membranes (ERM) associated with stage 4 macular holes (MH) so as to establish a vitreoretinal rationale for surgery in stage 4 MH. METHOD: Consecutive patients with stage 4 MH undergoing vitrectomy and membrane peeling were recruited. Preoperatively, the eyes were examined for ERM formation over the macula and completeness of posterior hyaloid membrane (PHM) separation from the retina. ERM peel specimens obtained during surgery were sent for histological and immunocytochemical studies and were compared with the PHM specimens taken from a previous post-mortem study of eyes with physiological posterior vitreous detachment but without macular holes. RESULT: A total of 13 patients with stage 4 MH fulfilled the inclusion criteria and were recruited. Preoperatively, all eyes had an ERM over the macula and incomplete separation of the PHM seen as a defect in the PHM on specular biomicroscopy. Histologically, the ERM specimens had very similar morphological characteristics to PHM, consisting of an eosinophilic membrane of varying thickness with scattered spindle-shaped cells. The membranes stained positively for type IV collagen while the cells were glial fibrillary acidic protein positive. Postoperatively, successful closure of MH was achieved in all cases. CONCLUSION: Stage 4 MH is characterised by incomplete separation of the PHM from the retina with remnants overlying the macula manifesting as ERM. Removal of the ERM is required during vitrectomy in order to relieve the tangential forces involved in the development of MH.
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Membrana Epirretinal/cirugía , Perforaciones de la Retina/cirugía , Anciano , Anciano de 80 o más Años , Colágeno/metabolismo , Membrana Epirretinal/metabolismo , Membrana Epirretinal/patología , Femenino , Estudios de Seguimiento , Proteína Ácida Fibrilar de la Glía/metabolismo , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Perforaciones de la Retina/patología , Perforaciones de la Retina/fisiopatología , Manejo de Especímenes , Resultado del Tratamiento , Agudeza Visual , Vitrectomía/métodosRESUMEN
The fatty acid composition of phospholipids and the contents of docosahexaenoic acid (DHA)-containing diacyl phosphatidylcholine and diacyl phosphatidylethanolamine molecular species were determined from brains of five fresh-water fish species from a boreal region adapted to 5 degrees C, five fresh-water fish species from a temperate region acclimated to 5 degrees C, five fresh-water fish species from a temperate region acclimated to 20 degrees C, and three fresh water fish species from a subtropic region adapted to 25-26 degrees C, as well as six mammalian species and seven bird species. There was little difference in DHA levels of fish brains from the different thermal environments; mammalian and bird brain phospholipids contained a few percentage points less DHA than those of the fish investigated. Molecular species of 22:6/22:6, 22:6/20:5, 22:6/20:4, 16:0/22:6, 18:0/22:6, and 18:1/22:6 were identified from all brain probes, and 16:0/22:6, 18:0/22:6, and 18:1/22:6 were the dominating species. Cold-water fish brains were rich in 18:1/22:6 diacyl phosphatidylethanolamine (and, to a lesser degree, in diacyl phosphatidylcholine), and its level decreased with increasing environmental/body temperature. The ratio of 18:0/22:6 to 16:0/22:6 phosphatidylcholine and phosphatidylethanolamine was inversely related to body temperature. Phospholipid vesicles from brains of cold-acclimated fish were more fluid, as assessed by using a 1, 6-diphenyl-1,3,5-hexatriene fluorescent probe, than those from bird brains, but the fluidities were almost equal at the respective body temperatures. It is concluded that the relative amounts of these molecular species and their ratios to each other are the major factors contributing to the maintenance of proper fluidity relationships throughout the evolutionary chain as well as helping to maintain important brain functions such as signal transduction and membrane permeability.
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Química Encefálica , Ácidos Docosahexaenoicos/análisis , Fosfolípidos/análisis , Animales , Aves , Temperatura Corporal , Ácidos Grasos/análisis , Peces , Polarización de Fluorescencia , Fluidez de la MembranaRESUMEN
Docosahexaenoic acid (DHA) is essential for the growth and functional development of the brain in infants. DHA is also required for maintenance of normal brain function in adults. The inclusion of plentiful DHA in the diet improves learning ability, whereas deficiencies of DHA are associated with deficits in learning. DHA is taken up by the brain in preference to other fatty acids. The turnover of DHA in the brain is very fast, more so than is generally realized. The visual acuity of healthy, full-term, formula-fed infants is increased when their formula includes DHA. During the last 50 years, many infants have been fed formula diets lacking DHA and other omega-3 fatty acids. DHA deficiencies are associated with foetal alcohol syndrome, attention deficit hyperactivity disorder, cystic fibrosis, phenylketonuria, unipolar depression, aggressive hostility, and adrenoleukodystrophy. Decreases in DHA in the brain are associated with cognitive decline during aging and with onset of sporadic Alzheimer disease. The leading cause of death in western nations is cardiovascular disease. Epidemiological studies have shown a strong correlation between fish consumption and reduction in sudden death from myocardial infarction. The reduction is approximately 50% with 200 mg day(-1)of DHA from fish. DHA is the active component in fish. Not only does fish oil reduce triglycerides in the blood and decrease thrombosis, but it also prevents cardiac arrhythmias. The association of DHA deficiency with depression is the reason for the robust positive correlation between depression and myocardial infarction. Patients with cardiovascular disease or Type II diabetes are often advised to adopt a low-fat diet with a high proportion of carbohydrate. A study with women shows that this type of diet increases plasma triglycerides and the severity of Type II diabetes and coronary heart disease. DHA is present in fatty fish (salmon, tuna, mackerel) and mother's milk. DHA is present at low levels in meat and eggs, but is not usually present in infant formulas. EPA, another long-chain n-3 fatty acid, is also present in fatty fish. The shorter chain n-3 fatty acid, alpha-linolenic acid, is not converted very well to DHA in man. These longchain n-3 fatty acids (also known as omega-3 fatty acids) are now becoming available in some foods, especially infant formula and eggs in Europe and Japan. Fish oil decreases the proliferation of tumour cells, whereas arachidonic acid, a longchain n-6 fatty acid, increases their proliferation. These opposite effects are also seen with inflammation, particularly with rheumatoid arthritis, and with asthma. DHA has a positive effect on diseases such as hypertension, arthritis, atherosclerosis, depression, adult-onset diabetes mellitus, myocardial infarction, thrombosis, and some cancers.
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Grasas de la Dieta/administración & dosificación , Grasas de la Dieta/farmacología , Ácidos Docosahexaenoicos/administración & dosificación , Ácidos Docosahexaenoicos/farmacología , Animales , Humanos , Estado NutricionalAsunto(s)
Grasas Insaturadas en la Dieta , Ácidos Docosahexaenoicos , Ácido Eicosapentaenoico , Alimentos Fortificados , Lípidos/sangre , Agregación Plaquetaria , Adolescente , Adulto , Animales , Pollos , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Ácidos Docosahexaenoicos/administración & dosificación , Ácidos Docosahexaenoicos/farmacología , Huevos , Femenino , Humanos , Masculino , Carne , Leche , Agregación Plaquetaria/efectos de los fármacos , PorcinosRESUMEN
Carp (Cyprinus carpio L.) whole brain was used to investigate the thermal acclimation changes under normoxic conditions of three-subclasses (alkenylacyl-, alkylacyl- and diacyl-subclasses) of choline glycerophospholipids (CGP), ethanolamine glycerophospholipids (EGP) and inositol glycerophospholipids (IGP) as well as their acyl chain profiles and molecular species composition. The alkenylacyl subclass of CGP and IGP and the alkylacyl subclass of CGP and EGP varied significantly during summer (25 degrees C) acclimation compared to winter (5 degrees C). The levels of alkenylacyl and alkylacyl-CGP, alkylacyl-EGP and alkenylacyl-IGP were 17.3-, 3.7-, 3.5- and 1.3-fold higher in the summer, respectively, while the alkenylacyl EGP was moderately lower. The levels of diacyl subclasses from CGP and IGP were considerably lower in the summer to compensate for the higher proportion of alkenylacyl and alkylacyl subclasses. Significant changes of ether phospholipids and the reorganization of the molecular species composition of all lipid subclasses may be associated with the "fine tuning" of the physical properties of the cellular membranes in carp brain due to temperature acclimation. The overall acyl chain profile of the three subclasses of carp brain phospholipids showed differences in composition depending upon the subclass of the individual phospholipid. Generally the polyunsaturated fatty acid (PUFA) chain composition increased relative to monounsaturated fatty acid (MUFA) and saturated fatty acids (SFA) during winter acclimation. Docosahexaenoic acid (DHA) was richer in the winter compared to summer. However, no DHA was found in ether-containing species of IGP from either winter or summer, except for 2% in alkylacyl-IGP during the summer. The above observations suggest that the content of ether phospholipids (alkenylacyl and alkylacyl) as well as the reorganization of the molecular species composition of all phospholipids may serve to maintain a functional fluid-crystalline state to preserve the signaling functions in carp brain.