Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros











Intervalo de año de publicación
1.
BMC Gastroenterol ; 24(1): 250, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39107691

RESUMEN

BACKGROUND: The efficacy of highly restrictive dietary therapies such as exclusive enteral nutrition (EEN) in the induction of remission in Crohn's disease (CD) are well established, however, ongoing issues exist with its poor palatability, restrictions, and adherence. The primary aim of this review is to evaluate the current evidence for the efficacy of exclusively solid food diets on the induction and maintenance of clinical and biochemical remission in CD. Secondary aims include impact on endoscopic healing and quality of life. METHODS: A systematic review of all randomised controlled trials (RCTs), open-label randomised trials and head-to-head clinical trials assessing solid food diet intervention in patients with active or inactive Crohn's disease was conducted. Studies included adult and paediatric patients with a verified disease activity index at baseline and follow up (Harvey Bradshaw Index, HBI; Crohn's disease activity index, CDAI and paediatric CDAI, PCDAI). Additional secondary endpoints varied between studies, including endoscopic and biochemical responses, as well as quality of life measures. Two authors independently performed critical appraisals of the studies, including study selection and risk of bias assessments. RESULTS: 14 studies were included for review, with several studies suggesting clinically significant findings. Clinical remission was achieved in a paediatric population undertaking the Mediterranean diet (MD) (moderate risk of bias). In adults, the Crohn's disease exclusion diet (CDED) was comparable to the CDED with partial enteral nutrition (PEN) diet in induction of remission (moderate risk of bias). A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet was also shown to decrease symptoms in patients with quiescent or mildly active CD (high risk of bias), however, this was not corroborated by other low FODMAP diet studies. CONCLUSIONS: There are promising outcomes for the MD and CDED in inducing clinical remission in mild to moderate CD. The results need to be interpreted with caution due to design limitations, including issues with combining outcomes among CD and UC patients, and small sample size. The current evidence for solid food dietary therapy in CD is limited by the lack of high quality studies and moderate to high bias. Future well designed studies are needed to confirm their efficacy.


Asunto(s)
Enfermedad de Crohn , Inducción de Remisión , Enfermedad de Crohn/dietoterapia , Enfermedad de Crohn/terapia , Humanos , Calidad de Vida , Nutrición Enteral/métodos , Adulto , Ensayos Clínicos Controlados Aleatorios como Asunto , Niño
2.
medRxiv ; 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39211867

RESUMEN

Precision medicine promises significant health benefits but faces challenges such as the need for complex data management and analytics, interdisciplinary collaboration, and education of researchers, healthcare professionals, and participants. Addressing these needs requires the integration of computational experts, engineers, designers, and healthcare professionals to develop user-friendly systems and shared terminologies. The widespread adoption of large language models (LLMs) like GPT-4 and Claude 3 highlights the importance of making complex data accessible to non-specialists. The Stanford Data Ocean (SDO) strives to mitigate these challenges through a scalable, cloud-based platform that supports data management for various data types, advanced research, and personalized learning in precision medicine. SDO provides AI tutors and AI-powered data visualization tools to enhance educational and research outcomes and make data analysis accessible for users from diverse educational backgrounds. By extending engagement and cutting-edge research capabilities globally, SDO particularly benefits economically disadvantaged and historically marginalized communities, fostering interdisciplinary biomedical research and bridging the gap between education and practical application in the biomedical field.

3.
Preprint en Inglés | bioRxiv | ID: ppbiorxiv-434150

RESUMEN

Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2 (COVID-19), is a positive single-stranded RNA virus with a 30 kb genome that is responsible for the current pandemic. To date, the genomes of global COVID-19 variants have been primarily characterized via short-read sequencing methods. Here, we devised a long-read RNA (IsoSeq) sequencing approach to characterize the COVID-19 transcript landscape and expression of its [~]27 coding regions. Our analysis identified novel COVID-19 transcripts including a) a short [~]65-70 nt 5-UTR fused to various downstream ORFs encoding accessory proteins such as the envelope, ORF 8, and ORF 9 (nucleocapsid) proteins, that are relatively highly expressed, b) novel SNVs that are differentially expressed, whereby a subset are suggestive of partial RNA editing events, and c) SNVs at functional sites, whereby at least one is associated with a differentially expressed spike protein isoform. These previously uncharacterized COVID-19 isoforms, expressed genes, and gene variants were corroborated using ddPCR. Understanding this transcriptional complexity may help provide insight into the biology and pathogenicity of SARS-CoV-2 compared to other coronaviruses.

4.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-20057539

RESUMEN

IMPORTANCECoronavirus disease 2019 (COVID-19) is a global pandemic associated with high mortality and effective treatment to prevent clinical deterioration to severe pneumonia has not yet been well clarified. OBJECTIVETo investigate the role of several adjuvant treatments in preventing severe pneumonia in patients with COVID-19. DESIGN, SETTING, AND PARTICIPANTSMulticenter, retrospective cohort study of 564 consecutively hospitalized patients with confirmed COVID-19 at Third Xiangya Hospital of Central South University, Changsha Public Health Treatment Center, First Hospital of Yueyang, Junshan Peoples Hospital of Yueyang, Central Hospital of Shaoyang, Central Hospital of Xiangtan, Second Hospital of Changde, Central Hospital of Loudi, and First Affiliated Hospital of University of South China in Hunan province from January 17, 2020 to February 28, 2020; The final date of follow-up was March 15, 2020. EXPOSURESNonspecific antivirals (arbidol, lopinavir/ritonavir, and interferon ), antihypertensives, and chloroquine. MAIN OUTCOMES AND MEASURESThe development of severe COVID-19 pneumonia; Demographic, epidemiological, clinical, laboratory, radiological, and treatment data were collected and analyzed. RESULTSOf 564 patients, the median age was 47 years (interquartile range, 36-58 years), and 284 (50.4%) patients were men. Sixty-nine patients (12.2%) developed severe pneumonia. Patients who developed severe pneumonia were older (median age of 59 and 45 years, respectively), and more patients had comorbidities including hypertension (30.4% and 12.3%, respectively), diabetes (17.4% and 6.7%, respectively), and cardiovascular disease (8.7% and 3.2%, respectively) and presented with fever (84.1% and 60.4%, respectively) and shortness of breath (10.1% and 3.8%, respectively) compared with those who did not. Nonspecific antiviral therapy did not prevent clinical progression to severe pneumonia, although fewer hypertensive patients on angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers (ACEI/ARB) therapy developed severe pneumonia in contrast with those on non-ACEI/ARB antihypertensive therapy (1 of 16 [6.3%] patients and 16 of 49 [32.7%] patients, respectively [difference, 26.4%; 95% CI, 1.5% to 41.3%]). Multivariate logistic regression analysis showed that hypertension without receiving ACEI/ARB therapy was an independent risk factor (odds ratio [OR], 2.07; 95% CI, 1.07 to 4.00) for developing severe pneumonia irrespective of age. Besides, none of patients treated with chloroquine developed severe pneumonia, though without significance (difference, 12.0%; 95% CI, -3.5% to 30.0%) by propensity score matching. CONCLUSIONS AND RELEVANCEHypertensive patients on ACEI or ARB may be protective from severe pneumonia in COVID-19 and hence these therapies should not be ceased unless there is a strong indication or further epidemiological evidence. Though none of the current antiviral and immunoregulation therapy showed benefit in preventing COVID-19 progression, chloroquine deserved further investigation. KEYPOINTSO_ST_ABSQuestionC_ST_ABSDoes the use of adjuvant therapy reduce progression to severe pneumonia in patients with coronavirus disease 2019 (COVID-19)? FindingsIn this retrospective, observational cohort study involving 564 patients with confirmed COVID-19, hypertension was an independent risk factor for progression to severe pneumonia irrespective of age and those on angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) therapy were less likely to develop severe COVID-19 pneumonia, while nonspecific antivirals or chloroquine did not have significant impact on clinical progression. MeaningHypertensive patients with COVID-19 should not have ACEI or ARB ceased, unless there is a strong indication or further epidemiological evidence, given its potential protective effects.

5.
J Biol Chem ; 290(14): 8849-62, 2015 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-25635056

RESUMEN

Highly conserved molecular chaperone Hsp70 heat shock proteins play a key role in maintaining protein homeostasis (proteostasis). DnaK, a major Hsp70 in Escherichia coli, has been widely used as a paradigm for studying Hsp70s. In the absence of ATP, purified DnaK forms low-ordered oligomer, whereas ATP binding shifts the equilibrium toward the monomer. Recently, we solved the crystal structure of DnaK in complex with ATP. There are two molecules of DnaK-ATP in the asymmetric unit. Interestingly, the interfaces between the two molecules of DnaK are large with good surface complementarity, suggesting functional importance of this crystallographic dimer. Biochemical analyses of DnaK protein supported the formation of dimer in solution. Furthermore, our cross-linking experiment based on the DnaK-ATP structure confirmed that DnaK forms specific dimer in an ATP-dependent manner. To understand the physiological function of the dimer, we mutated five residues on the dimer interface. Four mutations, R56A, T301A, N537A, and D540A, resulted in loss of chaperone activity and compromised the formation of dimer, indicating the functional importance of the dimer. Surprisingly, neither the intrinsic biochemical activities, the ATP-induced allosteric coupling, nor GrpE co-chaperone interaction is affected appreciably in all of the mutations except for R56A. Unexpectedly, the interaction with co-chaperone Hsp40 is significantly compromised. In summary, this study suggests that DnaK forms a transient dimer upon ATP binding, and this dimer is essential for the efficient interaction of DnaK with Hsp40.


Asunto(s)
Proteínas de Escherichia coli/metabolismo , Proteínas del Choque Térmico HSP40/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Dimerización , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Polarización de Fluorescencia , Proteínas HSP70 de Choque Térmico/química , Proteínas HSP70 de Choque Térmico/genética , Mutagénesis Sitio-Dirigida , Unión Proteica , Resonancia por Plasmón de Superficie
6.
Nat Struct Mol Biol ; 20(7): 900-7, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23708608

RESUMEN

The 70-kilodalton (kDa) heat-shock proteins (Hsp70s) are ubiquitous molecular chaperones essential for cellular protein folding and proteostasis. Each Hsp70 has two functional domains: a nucleotide-binding domain (NBD), which binds and hydrolyzes ATP, and a substrate-binding domain (SBD), which binds extended polypeptides. NBD and SBD interact little when in the presence of ADP; however, ATP binding allosterically couples the polypeptide- and ATP-binding sites. ATP binding promotes polypeptide release; polypeptide rebinding stimulates ATP hydrolysis. This allosteric coupling is poorly understood. Here we present the crystal structure of an intact ATP-bound Hsp70 from Escherichia coli at 1.96-Å resolution. The ATP-bound NBD adopts a unique conformation, forming extensive interfaces with an SBD that has changed radically, having its α-helical lid displaced and the polypeptide-binding channel of its ß-subdomain restructured. These conformational changes, together with our biochemical assays, provide a structural explanation for allosteric coupling in Hsp70 activity.


Asunto(s)
Adenosina Trifosfato/metabolismo , Proteínas de Escherichia coli/química , Proteínas HSP70 de Choque Térmico/química , Adenosina Trifosfatasas/química , Adenosina Trifosfatasas/genética , Regulación Alostérica , Secuencia de Aminoácidos , Sitios de Unión , Secuencia Conservada , Cristalografía por Rayos X , Dimerización , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Enlace de Hidrógeno , Modelos Moleculares , Datos de Secuencia Molecular , Mutación Missense , Péptidos/metabolismo , Unión Proteica , Conformación Proteica , Pliegue de Proteína , Mapeo de Interacción de Proteínas , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA