Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Gastrointest Endosc ; 99(2): 146-154.e1, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37793505

RESUMEN

BACKGROUND AND AIMS: Endoscopic-related injuries (ERIs) for gastroenterologists are common and can impact longevity of an endoscopic career. This study examines sex differences in the prevalence of ERIs and ergonomic training during gastroenterology fellowship. METHODS: A 56-item anonymous survey was sent to 709 general and advanced endoscopy gastroenterology fellows at 73 U.S. training programs between May and June 2022. Demographic information was collected along with questions related to endoscopic environment, ergonomic instruction, technique, equipment availability, and ergonomic knowledge. Responses of female and male gastroenterology fellows were compared using χ2 and Fisher exact tests. RESULTS: Of the 236 respondents (response rate, 33.9%), 113 (44.5%) were women and 123 (52.1%) were men. Female fellows reported on average smaller hand sizes and shorter heights. More female fellows reported endoscopic equipment was not ergonomically optimized for their use. Additionally, more female fellows voiced preference for same-gender teachers and access to dial extenders and well-fitting lead aprons. High rates of postendoscopy pain were reported by both sexes, with significantly more women experiencing neck and shoulder pain. Trainees of both sexes demonstrated poor ergonomic awareness with an average score of 68% on a 5-point knowledge-based assessment. CONCLUSIONS: Physical differences exist between male and female trainees, and current endoscopic equipment may not be optimized for smaller hand sizes. This study highlights the urgent need for formal ergonomic training for trainees and trainers with consideration of stature and hand size to enhance safety, comfort, and equity in the training and practice of endoscopy.


Asunto(s)
Gastroenterólogos , Gastroenterología , Humanos , Masculino , Femenino , Gastroenterología/educación , Caracteres Sexuales , Endoscopía Gastrointestinal/educación , Gastroenterólogos/educación , Encuestas y Cuestionarios , Becas , Ergonomía
2.
Inflamm Bowel Dis ; 2023 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-38142126

RESUMEN

BACKGROUND: Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) frequently undergo restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) for medically refractory disease or colonic dysplasia/neoplasia. Subtotal colectomy with ileosigmoid or ileorectal anastomosis may have improved outcomes but is not well studied. Due to increased risk for colorectal cancer in PSC-IBD, there is hesitancy to perform subtotal colectomy. We aim to describe the frequency of colorectal dysplasia/neoplasia following IPAA vs subtotal colectomy in PSC-IBD patients. METHODS: We completed a retrospective study from 1972 to 2022 of patients with PSC-IBD who had undergone total proctocolectomy with IPAA or subtotal colectomy. We abstracted demographics, disease characteristics, and endoscopic surveillance data from the EMR. RESULTS: Of 125 patients (99 IPAA; 26 subtotal), the indication for surgery was rectal sparing medically refractory disease (51% vs 42%), dysplasia (37% vs 30%) and neoplasia (11% vs 26%) in IPAA vs subtotal colectomy patients, respectively. On endoscopic surveillance of IPAA patients, 2 (2%) had low-grade dysplasia (LGD) in the ileal pouch and 2 (2%) had LGD in the rectal cuff after an average of 8.4 years and 12.3 years of follow-up, respectively. One (1%) IPAA patient developed neoplasia of the rectal cuff after 17.8 years of surgical continuity. No subtotal colectomy patients had dysplasia/neoplasia in the residual colon or rectum. CONCLUSIONS: In patients with PSC-IBD, there was no dysplasia or neoplasia in those who underwent subtotal colectomy as opposed to the IPAA group. Subtotal colectomy may be considered a viable surgical option in patients with rectal sparing PSC-IBD if adequate endoscopic surveillance is implemented.


We sought to evaluate the risk of developing dysplasia in patients with both inflammatory bowel disease and primary sclerosing cholangitis, following surgery with either total proctocolectomy with ileal pouch-anal anastomosis or subtotal/total colectomy with ileosigmoid or ileorectal anastomosis.

3.
J Phys Chem B ; 127(45): 9734-9746, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37936402

RESUMEN

IA3 is a 68 amino acid natural peptide/protein inhibitor of yeast aspartic proteinase A (YPRA) that is intrinsically disordered in solution with induced N-terminal helicity when in the protein complex with YPRA. Based on the intrinsically disordered protein (IDP) parameters of fractional net charge (FNC), net charge density per residue (NCPR), and charge patterning (κ), the two domains of IA3 are defined to occupy different domains within conformationally based subclasses of IDPs, thus making IA3 a bimodal domain IDP. Site-directed spin labeling (SDSL) electron paramagnetic resonance (EPR) spectroscopy and low-field Overhauser dynamic nuclear polarization (ODNP) spectroscopy results show that these two domains possess different degrees of compaction and hydration diffusivity behavior. This work suggests that SDSL EPR line shapes, analyzed in terms of their local tumbling volume (VL), provide insights into the compaction of the unstructured IDP ensemble in solution and that protein sequence and net charge distribution patterns within a conformational subclass can impact bound water hydration dynamics, thus possibly offering an alternative thermodynamic property that can encode conformational binding and behavior of IDPs and liquid-liquid phase separations.


Asunto(s)
Proteínas Intrínsecamente Desordenadas , Saccharomyces cerevisiae , Espectroscopía de Resonancia por Spin del Electrón/métodos , Conformación Proteica , Marcadores de Spin , Secuencia de Aminoácidos , Proteínas Intrínsecamente Desordenadas/química
4.
Dig Dis Sci ; 68(12): 4306-4320, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37773554

RESUMEN

The intestinal barrier is composed of several essential elements including luminal enzymes, bile acids, water layer, epithelial layer, and enterocyte layer. It acts as a dynamic interface between the luminal contents of food, commensal and pathogenic bacteria, and the gastrointestinal tract. The role of barrier dysfunction is of significant research interest in the development and targeted treatment of chronic inflammatory gastrointestinal conditions, such as inflammatory bowel disease. This review aims to examine the role of intestinal barrier dysfunction in the development of inflammatory bowel disease, the pathophysiology of increased barrier permeability in inflammatory bowel disease, and to explore potential treatment targets and clinical applications.


Asunto(s)
Enfermedades Gastrointestinales , Enfermedades Inflamatorias del Intestino , Humanos , Mucosa Intestinal/patología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/patología , Intestinos/patología , Permeabilidad , Uniones Estrechas/patología
5.
Biochemistry ; 62(11): 1716-1724, 2023 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-37198000

RESUMEN

Saccharomyces cerevisiae IA3 is a 68 amino acid peptide inhibitor of yeast proteinase A (YPRA) characterized as a random coil when in solution, folding into an N-terminal amphipathic alpha helix for residues 2-32 when bound to YPRA, with residues 33-68 unresolved in the crystal complex. Circular dichroism (CD) spectroscopy results show that amino acid substitutions that remove hydrogen-bonding interactions observed within the hydrophilic face of the N-terminal domain (NTD) of IA3-YPRA crystal complex reduce the 2,2,2-trifluoroethanol (TFE)-induced helical transition in solution. Although nearly all substitutions decreased TFE-induced helicity compared to wild-type (WT), each construct did retain helical character in the presence of 30% (v/v) TFE and retained disorder in the absence of TFE. The NTDs of 8 different Saccharomyces species have nearly identical amino acid sequences, indicating that the NTD of IA3 may be highly evolved to adopt a helical fold when bound to YPRA and in the presence of TFE but remain unstructured in solution. Only one natural amino acid substitution explored within the solvent-exposed face of the NTD of IA3 induced TFE-helicity greater than the WT sequence. However, chemical modification of a cysteine by a nitroxide spin label that contains an acetamide side chain did enhance TFE-induced helicity. This finding suggests that non-natural amino acids that can increase hydrogen bonding or alter hydration through side-chain interactions may be important to consider when rationally designing intrinsically disordered proteins (IDPs) with varied biotechnological applications.


Asunto(s)
Proteínas Intrínsecamente Desordenadas , Solventes , Proteínas Intrínsecamente Desordenadas/genética , Estructura Secundaria de Proteína , Enlace de Hidrógeno , Secuencia de Aminoácidos , Saccharomyces cerevisiae , Dicroismo Circular , Trifluoroetanol/farmacología , Pliegue de Proteína
7.
Gastroenterol Rep (Oxf) ; 10: goac049, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36196255

RESUMEN

Crohn's disease is a chronic gastrointestinal inflammatory disorder, characterized by episodes of relapsing and remitting flares. As the disease mechanism becomes better elucidated, there is a significant increase in the number of available biologic therapies. This article summarizes and synthesizes current Food and Drug Administration-approved biological therapy for Crohn's disease and examines the positioning of medical therapy as emerging biologics break onto the market.

9.
Crohns Colitis 360 ; 3(1): otab009, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34222863

RESUMEN

BACKGROUND: Micronutrient deficiencies are common in patients with inflammatory bowel disease (IBD). To date, the literature has focused on vitamin D, vitamin B12, and iron deficiencies. METHODS: We report a case series of 20 patients with IBD and vitamin C deficiency treated at a single tertiary care center. RESULTS: Sixteen (80%) patients had symptoms of clinical scurvy, including arthralgia, dry brittle hair, pigmented rash, gingivitis, easy bruising, and/or brittle nails. Eighteen patients underwent a nutritional assessment, 10 (56%) patients reported complete avoidance of fruits and vegetables, and 3 (17%) reported reduced intake of fruits and vegetables. CONCLUSIONS: Vitamin C deficiency should be considered in IBD patients, particularly those with reduced fruit/vegetable intake, as it can lead to significant signs and symptoms.

10.
Gastroenterology ; 160(7): 2435-2450.e34, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33676971

RESUMEN

BACKGROUND & AIMS: Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of COVID-19, we investigated intestinal infection with SARS-CoV-2, its effect on pathogenesis, and clinical significance. METHODS: Human intestinal biopsy tissues were obtained from patients with COVID-19 (n = 19) and uninfected control individuals (n = 10) for microscopic examination, cytometry by time of flight analyses, and RNA sequencing. Additionally, disease severity and mortality were examined in patients with and without GI symptoms in 2 large, independent cohorts of hospitalized patients in the United States (N = 634) and Europe (N = 287) using multivariate logistic regressions. RESULTS: COVID-19 case patients and control individuals in the biopsy cohort were comparable for age, sex, rates of hospitalization, and relevant comorbid conditions. SARS-CoV-2 was detected in small intestinal epithelial cells by immunofluorescence staining or electron microscopy in 15 of 17 patients studied. High-dimensional analyses of GI tissues showed low levels of inflammation, including down-regulation of key inflammatory genes including IFNG, CXCL8, CXCL2, and IL1B and reduced frequencies of proinflammatory dendritic cells compared with control individuals. Consistent with these findings, we found a significant reduction in disease severity and mortality in patients presenting with GI symptoms that was independent of sex, age, and comorbid illnesses and despite similar nasopharyngeal SARS-CoV-2 viral loads. Furthermore, there was reduced levels of key inflammatory proteins in circulation in patients with GI symptoms. CONCLUSIONS: These data highlight the absence of a proinflammatory response in the GI tract despite detection of SARS-CoV-2. In parallel, reduced mortality in patients with COVID-19 presenting with GI symptoms was observed. A potential role of the GI tract in attenuating SARS-CoV-2-associated inflammation needs to be further examined.


Asunto(s)
COVID-19/virología , Enfermedades Gastrointestinales/virología , Inmunidad Mucosa , Mucosa Intestinal/virología , SARS-CoV-2/patogenicidad , Anciano , Anciano de 80 o más Años , COVID-19/diagnóstico , COVID-19/inmunología , COVID-19/mortalidad , Estudios de Casos y Controles , Células Cultivadas , Citocinas/sangre , Femenino , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/inmunología , Enfermedades Gastrointestinales/mortalidad , Interacciones Huésped-Patógeno , Humanos , Mediadores de Inflamación/sangre , Mucosa Intestinal/inmunología , Italia , Masculino , Persona de Mediana Edad , Ciudad de Nueva York , Pronóstico , Medición de Riesgo , Factores de Riesgo , SARS-CoV-2/inmunología , Carga Viral
11.
medRxiv ; 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-32935117

RESUMEN

Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of coronavirus disease 2019 (COVID-19), we investigated intestinal infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its effect on disease pathogenesis. SARS-CoV-2 was detected in small intestinal enterocytes by immunofluorescence staining or electron microscopy, in 13 of 15 patients studied. High dimensional analyses of GI tissues revealed low levels of inflammation in general, including active downregulation of key inflammatory genes such as IFNG, CXCL8, CXCL2 and IL1B and reduced frequencies of proinflammatory dendritic cell subsets. To evaluate the clinical significance of these findings, examination of two large, independent cohorts of hospitalized patients in the United States and Europe revealed a significant reduction in disease severity and mortality that was independent of gender, age, and examined co-morbid illnesses. The observed mortality reduction in COVID-19 patients with GI symptoms was associated with reduced levels of key inflammatory proteins including IL-6, CXCL8, IL-17A and CCL28 in circulation but was not associated with significant differences in nasopharyngeal viral loads. These data draw attention to organ-level heterogeneity in disease pathogenesis and highlight the role of the GI tract in attenuating SARS-CoV-2-associated inflammation with related mortality benefit. ONE SENTENCE SUMMARY: Intestinal infection with SARS-CoV-2 is associated with a mild inflammatory response and improved clinical outcomes.

12.
Blood Adv ; 1(15): 1120-1123, 2017 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-29296754
13.
Nat Chem Biol ; 12(10): 860-6, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27547920

RESUMEN

Oxidation of methionine disrupts the structure and function of a range of proteins, but little is understood about the chemistry that underlies these perturbations. Using quantum mechanical calculations, we found that oxidation increased the strength of the methionine-aromatic interaction motif, a driving force for protein folding and protein-protein interaction, by 0.5-1.4 kcal/mol. We found that non-hydrogen-bonded interactions between dimethyl sulfoxide (a methionine analog) and aromatic groups were enriched in both the Protein Data Bank and Cambridge Structural Database. Thermal denaturation and NMR spectroscopy experiments on model peptides demonstrated that oxidation of methionine stabilized the interaction by 0.5-0.6 kcal/mol. We confirmed the biological relevance of these findings through a combination of cell biology, electron paramagnetic resonance spectroscopy and molecular dynamics simulations on (i) calmodulin structure and dynamics, and (ii) lymphotoxin-α binding toTNFR1. Thus, the methionine-aromatic motif was a determinant of protein structural and functional sensitivity to oxidative stress.


Asunto(s)
Hidrocarburos Aromáticos/química , Metionina/química , Hidrocarburos Aromáticos/metabolismo , Metionina/metabolismo , Modelos Moleculares , Oxidación-Reducción , Teoría Cuántica
14.
Biochemistry ; 55(21): 2914-26, 2016 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-27191789

RESUMEN

Synaptotagmin I (Syt I) is a vesicle-localized integral membrane protein that senses the calcium ion (Ca(2+)) influx to trigger fast synchronous release of neurotransmitter. How the cytosolic domains of Syt I allosterically communicate to propagate the Ca(2+) binding signal throughout the protein is not well understood. In particular, it is unclear whether the intrinsically disordered region (IDR) between Syt I's transmembrane helix and first C2 domain (C2A) plays an important role in allosteric modulation of Ca(2+) binding. Moreover, the structural propensity of this IDR with respect to membrane lipid composition is unknown. Using differential scanning and isothermal titration calorimetry, we found that inclusion of the IDR does indeed allosterically modulate Ca(2+) binding within the first C2 domain. Additionally through application of nuclear magnetic resonance, we found that Syt I's IDR interacts with membranes whose lipid composition mimics that of a synaptic vesicle. These findings not only indicate that Syt I's IDR plays a role in regulating Syt I's Ca(2+) sensing but also indicate the IDR is exquisitely sensitive to the underlying membrane lipids. The latter observation suggests the IDR is a key route for communication of lipid organization to the adjacent C2 domains.


Asunto(s)
Calcio/metabolismo , Lípidos/química , Vesículas Sinápticas/metabolismo , Sinaptotagmina I/química , Sinaptotagmina I/metabolismo , Regulación Alostérica , Secuencia de Aminoácidos , Sitios de Unión , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Humanos , Resonancia Magnética Nuclear Biomolecular , Dominios Proteicos , Transmisión Sináptica , Vesículas Sinápticas/química
15.
Biochim Biophys Acta ; 1838(9): 2331-40, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24657395

RESUMEN

Eukaryotic lipids in a bilayer are dominated by weak cooperative interactions. These interactions impart highly dynamic and pliable properties to the membrane. C2 domain-containing proteins in the membrane also interact weakly and cooperatively giving rise to a high degree of conformational plasticity. We propose that this feature of weak energetics and plasticity shared by lipids and C2 domain-containing proteins enhance a cell's ability to transduce information across the membrane. We explored this hypothesis using information theory to assess the information storage capacity of model and mast cell membranes, as well as differential scanning calorimetry, carboxyfluorescein release assays, and tryptophan fluorescence to assess protein and membrane stability. The distribution of lipids in mast cell membranes encoded 5.6-5.8bits of information. More information resided in the acyl chains than the head groups and in the inner leaflet of the plasma membrane than the outer leaflet. When the lipid composition and information content of model membranes were varied, the associated C2 domains underwent large changes in stability and denaturation profile. The C2 domain-containing proteins are therefore acutely sensitive to the composition and information content of their associated lipids. Together, these findings suggest that the maximum flow of signaling information through the membrane and into the cell is optimized by the cooperation of near-random distributions of membrane lipids and proteins. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.


Asunto(s)
Membrana Celular/química , Membrana Dobles de Lípidos/química , Lípidos/química , Proteínas de la Membrana/química , Rastreo Diferencial de Calorimetría , Membrana Celular/metabolismo , Humanos , Mastocitos/química , Microdominios de Membrana/química , Fosfatidilcolinas/química , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Transducción de Señal
16.
Artículo en Inglés | AIM (África) | ID: biblio-1258641

RESUMEN

Introduction: Improper management of and resultant poor outcomes from upper extremity injuries can be economically devastating to patients who rely on manual labour for survival. This is a pilot study using the Quick DASH Survey (disabilities of arm; shoulder and hand); a validated outcome measurement tool. Our objective was to assess functional outcomes of patients with acute upper extremity injuries who were cared for by non-physician clinicians as part of a task-shifting programme. Methods :This pilot study was performed at the Karoli Lwanga Hospital Emergency Centre (EC) in Uganda. Patients were identified retrospectively by querying the EC quality assurance database. An initial list of all patients who sustained traumatic injury (road traffic accident; assault) between March 2012 and February 2013 was narrowed to patients with upper extremity trauma; those 18 years and older; and those with cellular phone access. This subset of patients was called and administered the Quick DASH. The results were subsequently analysed using the standardised DASH metrics. These outcome measures were further analysed based upon injury type (simple laceration; complex laceration; fracture and subluxation). Results :There were a total of 25 initial candidates; of which only 17 were able to complete the survey. Using the Quick DASH Outcome Measure; our 17 patients had a mean score of 28.86 (range 5.0-56.8). Conclusions : When compared to the standardised Quick DASH outcomes (no work limitation at 27.5 vs. work limited by injury at 52.6) the non-physician clinicians appear to be performing upper extremity repairs with good outcomes. The key variable to successful repair was the initial injury type. Although accommodations needed to be made to the standard Quick DASH protocol; the tool appears to be usable in non-traditional settings


Asunto(s)
Proyectos Piloto , Calidad de la Atención de Salud , Uganda , Extremidad Superior , Heridas y Lesiones
17.
J Psychol ; 144(2): 205-19, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20307023

RESUMEN

The sibling relationship is an involuntary one that individuals often maintain throughout life (V. G. Cicirelli, 1995; M. A. Fitzpatrick & D. M. Badzinski, 1994; P. Noller & M. A. Fitzpatrick, 1993). The authors investigated interpersonal communication motives in sibling relationships to examine the way in which siblings voluntarily maintain their relationships with one another over time. R. B. Rubin, E. M. Perse, and C. A. Barbato (1988) identified 6 primary motives that people have for communicating: affection, control, escape, inclusion, pleasure, and relaxation. Participants were 323 individuals who reported on why they communicated with 1 of their siblings. The authors found differences between male and females participants and between intact and nonintact families. The number of siblings and the birth order of siblings also appeared to affect motives for communicating. The authors discuss the implications and limitations.


Asunto(s)
Comunicación , Motivación , Relaciones entre Hermanos , Adolescente , Adulto , Orden de Nacimiento , Femenino , Humanos , Masculino , Factores Sexuales , Encuestas y Cuestionarios , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...