Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Br J Haematol ; 204(4): 1249-1261, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38098201

RESUMEN

Tyrosine kinase inhibitors (TKIs) have drastically improved the outcomes of pCML (paediatric CML) but data on long-term off-target toxicities of TKIs in children are scarce. In this single-centre, retrospective cum prospective study of pCML in chronic phase, we report our experience of treating 173 children with imatinib and following them for long-term toxicities. Mean (SD) time to attain CHR, CCyR and MMR were 3.05 (2.1), 10.6 (8.4) and 43.4 (31.8) months respectively. DMR was not attained in 59 (34%) patients at last follow-up. Ten patients were switched to second-generation TKIs (2G-TKIs; nilotinib = 1/dasatinib = 9) due to poor/loss in response, of which seven had kinase domain mutations. Three patients progressed to the blastic phase. At a median follow-up of 84 (3-261) months, the 5-year EFS and OS for the entire cohort were 96.9% (95% CI: 93.4-100) and 98.7% (95% CI: 96.9-100) respectively. Screening for long-term toxicities revealed low bone density and hypovitaminosis D in 70% and 80% respectively. Other late effects included short stature (27%), delayed puberty (15%), poor sperm quality (43%) and miscellaneous endocrinopathies (8%). Children younger than 5 years at diagnosis were more susceptible to growth and endocrine toxicities (p = 0.009). Regular monitoring for long-term toxicities, timely intervention and trial of discontinuation whenever feasible are likely to improve the long-term outlook of pCML.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva , Niño , Humanos , Masculino , Dasatinib , Estudios de Seguimiento , Hospitales , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Estudios Prospectivos , Inhibidores de Proteínas Quinasas/efectos adversos , Estudios Retrospectivos , Semen , Resultado del Tratamiento , Preescolar
2.
Radiat Environ Biophys ; 63(2): 297-306, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38722389

RESUMEN

For locally advanced cervical cancer, the standard therapeutic approach involves concomitant chemoradiation therapy, supplemented by a brachytherapy boost. Moreover, an external beam radiotherapy (RT) boost should be considered for treating gross lymph node (LN) volumes. Two boost approaches exist with Volumetric Intensity Modulated Arc Therapy (VMAT): Sequential (SEQ) and Simultaneous Integrated Boost (SIB). This study undertakes a comprehensive dosimetric and radiobiological comparison between these two boost strategies. The study encompassed ten patients who underwent RT for cervical cancer with node-positive disease. Two sets of treatment plans were generated for each patient: SIB-VMAT and SEQ-VMAT. Dosimetric as well as radiobiological parameters including tumour control probability (TCP) and normal tissue complication probability (NTCP) were compared. Both techniques were analyzed for two different levels of LN involvement - only pelvic LNs and pelvic with para-aortic LNs. Statistical analysis was performed using SPSS software version 25.0. SIB-VMAT exhibited superior target coverage, yielding improved doses to the planning target volume (PTV) and gross tumour volume (GTV). Notably, SIB-VMAT plans displayed markedly superior dose conformity. While SEQ-VMAT displayed favorable organ sparing for femoral heads, SIB-VMAT appeared as the more efficient approach for mitigating bladder and bowel doses. TCP was significantly higher with SIB-VMAT, suggesting a higher likelihood of successful tumour control. Conversely, no statistically significant difference in NTCP was observed between the two techniques. This study's findings underscore the advantages of SIB-VMAT over SEQ-VMAT in terms of improved target coverage, dose conformity, and tumour control probability. In particular, SIB-VMAT demonstrated potential benefits for cases involving para-aortic nodes. It is concluded that SIB-VMAT should be the preferred approach in all cases of locally advanced cervical cancer.


Asunto(s)
Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada , Neoplasias del Cuello Uterino , Humanos , Neoplasias del Cuello Uterino/radioterapia , Neoplasias del Cuello Uterino/patología , Femenino , Radioterapia de Intensidad Modulada/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radiometría , Persona de Mediana Edad , Órganos en Riesgo/efectos de la radiación , Metástasis Linfática/radioterapia
3.
Prep Biochem Biotechnol ; 53(2): 120-135, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35499507

RESUMEN

In recent years, biodiesel synthesis and production demands have increased because of its high degradability, cleaner emissions, non-toxicity, and an alternative to petroleum diesel. In this context, Single Cell Oil (SCO) has been identified as an alternative feedstock, having the advantage of accumulating high intracellular lipid. SCO/microbial lipids are potential alternatives for sustainable biodiesel production. The traditional technique for biodiesel production from the oils obtained from microbes generally requires two steps: lipid extraction and transesterification. In-situ transesterification is an innovative and renewable process for biodiesel production. It rules out the need to isolate and refine the feedstock lipid, as it directly uses biomass in a single step, i.e., the pretreated biomass will be subjected to in-situ transesterification in the presence of catalysts. Hence, the production cost can be reduced by eliminating the lipid extraction procedure. The current review focuses on the basic features and advantages of in-situ transesterification of SCO for biodiesel production with the aid of short-chain alcohols along with different acid, base, and enzyme catalysts. In addition, a comparative study was carried out to highlight the merits of in-situ transesterification over conventional transesterification.


Asunto(s)
Biocombustibles , Aceites , Esterificación , Ácidos Grasos , Catálisis
4.
Physiol Mol Biol Plants ; 29(1): 131-143, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36733838

RESUMEN

Thermal stress is a major abiotic stress in wheat and is highly complex in mechanism. A large area in northwestern plain zones (NWPZ), which is the wheat bowl of India is affected by heat stress. Climate change also causes an abrupt increase in temperature at different growth stages of wheat. Thus, wiser selection of stress tolerant varieties is an important strategy to combat the climate change effect. The present study aims for physiological and biochemical screening of timely sown NWPZ wheat varieties (WB2, HD3086, DBW88, DPW621-50, DBW17, HD2967 and PBW550) of India for their thermal stress tolerance along with heat tolerant (RAJ3765) and susceptible checks (RAJ4014) at seedling stage. The experiment was conducted in completely randomized design under controlled laboratory condition and heat stress was induced at 37 °C at seedling stage. Later different physio-biochemical traits were studied in both control and stress seedlings. All traits exhibited significant variations among genotypes under heat stress condition. Root and shoot weight, relative water content, chlorophyll content index and chlorophyll fluorescence reduced significantly, whereas membrane leakage, osmotic potential, catalase, ascorbate peroxidase, guaiacol peroxidase, malondialdehyde content and proline content were increased in stress plants. A tolerance matrix was prepared based on stress response of the genotypes for each trait and a final tolerance score was given to each genotype. Based on this tolerance matrix, DBW88 and PBW550 were identified as tolerant, DPW621-50, DBW17 and HD2967 as moderately susceptible and HD3086 and WB2 as susceptible to heat stress. Earlier studies parade that seedling level stress tolerance has high correlation with adult level stress tolerance under field condition in wheat. Hence, this study helps in wiser selection of varieties for sowing in NWPZ based on weather forecast of the location for creating varietal mosaic in context of climate change.

5.
Nutr Cancer ; 74(3): 1122-1137, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33998358

RESUMEN

Acute myeloid leukemia is characterized by abnormal differentiation of hematopoietic stem cells, leading to the accumulation of immature myeloid cells. Differentiation therapy has been a successful treatment option for acute promyelocytic leukemia but suffers from adverse effects. Therefore, search for novel differentiation-inducing agents with minimal side effects is desirable. Securinine, a naturally-occurring alkaloid, induces differentiation in various leukemic cells and apoptosis in other types of cancers. However, the underlying molecular mechanism(s) remain elusive. Our study aimed to elucidate the possible molecular mechanism(s) and signaling events involved in securinine-induced differentiation of HL-60 cells. Securinine inhibited proliferation in a time- and dose-dependent manner and triggered differentiation. A higher CD14+ population indicated maturation toward monocytic lineage. Securinine caused cell cycle arrest at the G0/G1 phase and enhanced ROS generation. Quantitative gene expression analysis showed significant down-regulation of C/EBP-α, C/EBP-ε, GAΤΑ, and c-myc and up-regulation of the PU.1 gene. The expression of distinct protein kinases Lyn, Chk-2, Yes, FAK, c-Jun, and JNK were enhanced. Use of specific inhibitors of crucial intracellular signaling proteins indicated that JNK and ERK blockade resulted in a significant decline in differentiation. These data thus confirm that securinine induces differentiation through the activation of the JNK-ERK signaling pathway in HL-60 cells.


Asunto(s)
Compuestos Heterocíclicos de Anillo en Puente , Azepinas/farmacología , Diferenciación Celular , Células HL-60 , Compuestos Heterocíclicos de Anillo en Puente/farmacología , Humanos , Lactonas , Sistema de Señalización de MAP Quinasas , Piperidinas
6.
J Gastroenterol Hepatol ; 37(3): 489-498, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34672022

RESUMEN

BACKGROUND AND AIM: Because acute infectious gastroenteritis may cause post-infection irritable bowel syndrome and functional dyspepsia and the severe acute respiratory syndrome coronavirus-2 affects gastrointestinal (GI) tract, coronavirus disease-19 (COVID-19) may cause post-infection-functional GI disorders (FGIDs). We prospectively studied the frequency and spectrum of post-infection-FGIDs among COVID-19 and historical healthy controls and the risk factors for its development. METHODS: Two hundred eighty patients with COVID-19 and 264 historical healthy controls were followed up at 1 and 3 months using translated validated Rome Questionnaires for the development of chronic bowel dysfunction (CBD), dyspeptic symptoms, and their overlap and at 6-month for IBS, uninvestigated dyspepsia (UD) and their overlap. Psychological comorbidity was studied using Rome III Psychosocial Alarm Questionnaire. RESULTS: At 1 and 3 months, 16 (5.7%), 16 (5.7%), 11 (3.9%), and 24 (8.6%), 6 (2.1%), 9 (3.2%) of COVID-19 patients developed CBD, dyspeptic symptoms, and their overlap, respectively; among healthy controls, none developed dyspeptic symptoms and one developed CBD at 3 months (P < 0.05). At 6 months, 15 (5.3%), 6 (2.1%), and 5 (1.8%) of the 280 COVID-19 patients developed IBS, UD, and IBS-UD overlap, respectively, and one healthy control developed IBS at 6 months (P < 0.05 for all except IBS-UD overlap). The risk factors for post-COVID-19 FGIDs at 6 months included symptoms (particularly GI), anosmia, ageusia, and presence of CBD, dyspeptic symptoms, or their overlap at 1 and 3 months and the psychological comorbidity. CONCLUSIONS: This is the first study showing COVID-19 led to post-COVID-19 FGIDs. Post-COVID-19 FGIDs may pose a significant economic, social, and healthcare burden to the world.


Asunto(s)
COVID-19 , Enfermedades Gastrointestinales , COVID-19/complicaciones , COVID-19/epidemiología , Estudios de Casos y Controles , Enfermedades Gastrointestinales/epidemiología , Enfermedades Gastrointestinales/virología , Humanos , Incidencia , Estudios Prospectivos , Factores de Riesgo , SARS-CoV-2
7.
Mol Plant Microbe Interact ; 34(8): 962-972, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33881922

RESUMEN

Ralstonia solanacearum causes bacterial wilt disease in solanaceous crops. Identification of avirulence type III-secreted effectors recognized by specific disease resistance proteins in host plant species is an important step toward developing durable resistance in crops. In the present study, we show that R. solanacearum effector RipJ functions as an avirulence determinant in Solanum pimpinellifolium LA2093. In all, 10 candidate avirulence effectors were shortlisted based on the effector repertoire comparison between avirulent Pe_9 and virulent Pe_1 strains. Infection assays with transgenic strain Pe_1 individually carrying a candidate avirulence effector from Pe_9 revealed that only RipJ elicits strong bacterial wilt resistance in S. pimpinellifolium LA2093. Furthermore, we identified that several RipJ natural variants do not induce bacterial wilt resistance in S. pimpinellifolium LA2093. RipJ belongs to the YopJ family of acetyltransferases. Our sequence analysis indicated the presence of partially conserved putative catalytic residues. Interestingly, the conserved amino acid residues in the acetyltransferase catalytic triad are not required for effector-triggered immunity. In addition, we show that RipJ does not autoacetylate its lysine residues. Our study reports the identification of the first R. solanacearum avirulence protein that triggers bacterial wilt resistance in tomato. We expect that our discovery of RipJ as an avirulence protein will accelerate the development of bacterial wilt-resistant tomato varieties in the future.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.


Asunto(s)
Ralstonia solanacearum , Solanum , Proteínas Bacterianas/genética , Resistencia a la Enfermedad , Enfermedades de las Plantas
8.
J Med Virol ; 93(4): 2281-2286, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33230819

RESUMEN

There are more than 350 real-time polymerase chain reaction (RT-PCR) coronavirus disease-2019 (COVID-19) testing kits commercially available but these kits have not been evaluated for pooled sample testing. Thus, this study was planned to compare and evaluate seven commercially available kits for pooled samples testing. Diagnostic accuracy of (1) TRUPCR SARS-CoV-2 Kit (Black Bio), (2) TaqPath RT-PCR COVID-19 Kit (Thermo Fisher Scientific), (3) Allplex 2019-nCOV Assay (Seegene), (4) Patho detect COVID-19 PCR kit (My Lab), (5) LabGun COVID-19 RT-PCR Kit (Lab Genomics, Korea), (6) Fosun COVID-19 RT-PCR detection kit (Fosun Ltd.), (7) Real-time Fluorescent RT-PCR kit for SARS CoV-2 (BGI) was evaluated on precharacterised 40 positive and 10 negative COVID-19 sample pools. All seven kits detected all sample pools with low Ct values (<30); while testing weak positive pooled samples with high Ct value (>30); the TRUPCR Kit, TaqPath Kit, Allplex Assay, and BGI RT-PCR kit showed 100% sensitivity, specificity, and accuracy. However, the Fosun kit, LabGun Kit, and Patho detect kit could detect only 90%, 85%, and 75% of weakly positive samples, respectively. We conclude that all seven commercially available RT-PCR kits included in this study can be used for routine molecular diagnosis of COVID-19. However, regarding performing pooled sample testing, it might be advisable to use those kits that performed best regarding positive identification in samples' pool, that is TRUPCR SARS-CoV-2 Kit, TaqPath RT-PCR COVID-19 Kit, Allplex 2019-nCOV Assay, and BGI Real-time RT-PCR kit for detecting SARS CoV-2.


Asunto(s)
Prueba de COVID-19/métodos , COVID-19/diagnóstico , Juego de Reactivos para Diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , SARS-CoV-2/aislamiento & purificación , COVID-19/epidemiología , Técnicas de Laboratorio Clínico , Humanos , India/epidemiología , Estudios Prospectivos , ARN Viral/análisis , ARN Viral/genética , República de Corea , SARS-CoV-2/genética , Sensibilidad y Especificidad , Organización Mundial de la Salud
9.
Mol Biol Rep ; 47(11): 8629-8643, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33068231

RESUMEN

Wheat is produced worldwide over six continents with the European Union, China, India, Russia, and the United States as major producer countries. The productivity was recorded 749 million tons by harvesting from 220-million-hectare land. It is the need of the hour to develop stress-tolerant wheat varieties to enhance the productivity by 60% to provide food security to 9.6 billion-world population by 2050. Although the genotypes have been identified for heat, drought and salt tolerance, their underlying mechanism for tolerance is poorly understood. The detailed understanding of the mechanism and identification of critical factors participating in multiple abiotic stress tolerance is essential. In the present study, the contrasting wheat genotypes were intensely characterized and assessed for the expression of different stress responsive genes under lab conditions. The expression analysis revealed that SHN1, DREB6, NHX2 and AVP1 were found to be highly induced under heat, salt and drought stresses in wheat. Thus, these genes can be used as signature genes to identify the multiple stress-tolerant varieties in the breeding program. The novel variants of these genes can be targeted through breeding or genetic engineering or genome editing strategies to develop multiple abiotic stress tolerant wheat varieties.


Asunto(s)
Fitomejoramiento , Proteínas de Plantas/genética , Estrés Fisiológico/genética , Triticum , Regulación de la Expresión Génica de las Plantas , Genotipo , Factores de Transcripción/genética , Triticum/genética , Triticum/crecimiento & desarrollo
10.
Mol Biol Rep ; 46(3): 3557-3569, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30941642

RESUMEN

CRISPR technology has vividly increased its applications in last five years for genome editing in a wide range of organisms from bacteria to plants. It is mostly applied in the field of mammalian research. This emerging versatile tool can be utilized in crop improvement by targeting various traits to increase economic value and adaptability of the crop species under changing climate. In plants, Arabidopsis and rice are the most studied plant species in genome editing through CRISPR technology. Wheat is lagging behind in the utilization of CRISPR based genome modifications. The hexaploid, large genome size and the recalcitrant nature in terms of tissue culture are the major obstacles for CRISPR utilization in wheat. Recently, the IWGSC released the high quality of reference genome for wheat which will greatly accelerate the application of CRISPR-based genome engineering in wheat and helps to resolve the global issue of food security in coming decades. The exogenous DNA-free improved mutants with CRISPR technology having desired traits will increase the productivity under biotic and abiotic stress conditions. To address complex traits involving multigene, recently developed multiplex genome editing toolkits can be used. This is a first review of its kind in which the practical utilization and updates on CRISPR validation in wheat along with its future prospects for use of this technology in wheat improvement are comprehensively discussed. Thus, the compiled information will immensely benefit the researchers for utilization of CRISPR system in wheat improvement across the globe.


Asunto(s)
Sistemas CRISPR-Cas/genética , Edición Génica/métodos , Triticum/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Genes de Plantas/genética , Ingeniería Genética/métodos , Genoma de Planta/genética , Plantas Modificadas Genéticamente/genética , Poaceae/genética
11.
Biochem Biophys Res Commun ; 482(4): 961-967, 2017 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-27899317

RESUMEN

Plasticity and developmental capacity of stem cells have now been established as a promising tool to restore the degenerative disorders. The linearity differentiation of human mesenchymal stem cells (hMSCs) into adipogenic, chondrogenic, osteogenic and even in neuronal subtypes has been demonstrated. The number of xenobiotics such as dexamethasone, insulin, isobutyl 1-methyle xanthine and retinoic acid has been reported for the potential to differentiate hMSCs into neuronal subtypes. But, the applicability of indigenous neurotrophic factor-nerve growth factor (NGF) has not been explored for the purpose. Thus, the present investigations were carried out to study the NGF induced neuronal differentiation of hMSCs. Following the isolation, purification and characterization of hMSCs were allowed to differentiate into neuronal subtypes under the influence of NGF (50 ng/mL). At various concentrations of NGF, the neuronal makers were analysed at both mRNA and protein levels. Cells, exposed with NGF were showing the significant and gradual increase in the neuronal markers in differentiating cells. The magnitude of expression of markers was maximum at day 4 of differentiation. NGF at 50 ng/mL concentration was found to induce neuronal differentiation of hMSCs into neuronal subtypes.


Asunto(s)
Sangre Fetal/citología , Células Madre Mesenquimatosas/citología , Factores de Crecimiento Nervioso/metabolismo , Neurogénesis , Adulto , Separación Celular , Células Cultivadas , Femenino , Humanos , Células Madre Mesenquimatosas/metabolismo , Neuronas/citología , Neuronas/metabolismo , Adulto Joven
12.
J Med Virol ; 89(1): 49-54, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27329816

RESUMEN

Influenza A and Respiratory Syncytial Virus (RSV) has been recognized as a major cause of acute respiratory tract infection. H1N1 is one of the subtypes of influenza A, pandemic worldwide in July 2009, causing 18,449 deaths globally. To investigate the prevalence and clinical manifestation of the influenza A, H1N1pdm09, and RSV. Throat/nasal swab collected from the patients of all age group either outpatients/inpatients having respiratory illness from 2 to 5 days. The clinical data were recorded in a predesigned questionnaire. RNA was extracted and analyzed by real time PCR at a tertiary care center, 2009-2014. Total 4,352 samples tested for influenza A and H1N1. Out of 4,352, 32.2% (median positivity 21%; range 16-41% during 6 years) were positive for influenza A and 19% were H1N1 (median positivity 16.7%; range 8.7-23% during 6 years). Total 1653 samples were analyzed for RSV from 2011 to 2014, 12% were RSV positive (median positivity 11.35%; range 10-16.3% during 4 years). Pharyngitis, dyspnea were frequent symptoms in influenza A and H1N1 (P < 0.005) whereas bronchiolitis and pneumonia were commonly present in RSV (P < 0.005). The positivity of influenza A and H1N1 was higher in age-group 21-30, whereas RSV in infant and children. H1N1 and RSV were co-circulated and have common clinical symptoms particularly in lower age group. Therefore, laboratory confirmation is necessary for further disease prognosis. Age was an important risk factor that affects the positivity of influenza A, H1N1, and RSV. Different clinical manifestation of H1N1 and RSV will be helpful for early and accurate diagnosis. J. Med. Virol. 89:49-54, 2017. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/patología , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/patología , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios Epidemiológicos , Femenino , Humanos , India/epidemiología , Lactante , Recién Nacido , Gripe Humana/virología , Masculino , Persona de Mediana Edad , ARN Viral/análisis , ARN Viral/genética , ARN Viral/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Encuestas y Cuestionarios , Centros de Atención Terciaria , Adulto Joven
13.
Bioconjug Chem ; 28(11): 2647-2672, 2017 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-28767225

RESUMEN

The critical role of serotonin (5-hydroxytryptamine; 5-HT) and its receptors (5-HTRs) in the pathophysiology of diverse neuropsychiatric and neurodegenerative disorders render them attractive diagnostic and therapeutic targets for brain disorders. Therefore, the in vivo assessment of binding of 5-HT receptor ligands under a multitude of physiologic and pathologic scenarios may support more-accurate identification of disease and its progression and the patient's response to therapy as well as the screening of novel therapeutic strategies. The present Review aims to focus on the current status of radioligands used for positron-emission tomography (PET) and single-photon-emission computerized tomography (SPECT) imaging of human brain serotonin receptors. We further elaborate upon and emphasize the attributes that qualify a radioligand for theranostics on the basis of its frequency of use in clinics, its benefit to risk assessment in humans, and its continuous evolution, along with the major limitations.


Asunto(s)
Encéfalo/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Receptores de Serotonina/análisis , Proteínas de Transporte de Serotonina en la Membrana Plasmática/análisis , Tomografía Computarizada de Emisión de Fotón Único/métodos , Animales , Encéfalo/citología , Humanos , Modelos Moleculares , Neuronas , Radiofármacos/química
14.
Soft Matter ; 13(37): 6585-6593, 2017 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-28902216

RESUMEN

Probe rheology experiments, in which the dynamics of a small amount of probe chains dissolved in immobile matrix chains is discussed, have been performed for the development of molecular theories for entangled polymer dynamics. Although probe chain dynamics in probe rheology is considered hypothetically as single chain dynamics in fixed tube-shaped confinement, it has not been fully elucidated. For instance, the end-to-end relaxation of probe chains is slower than that for monodisperse melts, unlike the conventional molecular theories. In this study, the viscoelastic and dielectric relaxations of probe chains were calculated by primitive chain network simulations. The simulations semi-quantitatively reproduced the dielectric relaxation, which reflects the effect of constraint release on the end-to-end relaxation. Fair agreement was also obtained for the viscoelastic relaxation time. However, the viscoelastic relaxation intensity was underestimated, possibly due to some flaws in the model for the inter-chain cross-correlations between probe and matrix chains.

15.
J Chem Phys ; 147(18): 184903, 2017 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-29141414

RESUMEN

Although it has not been frequently discussed, contributions of the orientational cross-correlation (OCC) between entangled polymers are not negligible in the relaxation modulus. In the present study, OCC contributions were investigated for 4- and 6-arm star-branched and H-branched polymers by means of multi-chain slip-link simulations. Owing to the molecular-level description of the simulation, the segment orientation was traced separately for each molecule as well as each subchain composing the molecules. Then, the OCC was calculated between different molecules and different subchains. The results revealed that the amount of OCC between different molecules is virtually identical to that of linear polymers regardless of the branching structure. The OCC between constituent subchains of the same molecule is significantly smaller than the OCC between different molecules, although its intensity and time-dependent behavior depend on the branching structure as well as the molecular weight. These results lend support to the single-chain models given that the OCC effects are embedded into the stress-optical coefficient, which is independent of the branching structure.

16.
Soft Matter ; 12(44): 9068-9076, 2016 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-27774542

RESUMEN

Active bodies in viscous fluids interact hydrodynamically through self-generated flows. A stiff, apolar, active filament generates symmetric fluid flow around it and thus cannot self-propel. Here we study the mobility and aggregation induced by hydrodynamic flow in a suspension of stiff, apolar, active filaments. We consider two types of active filaments, with those producing extensile or contractile flows along their long axis. Lateral hydrodynamic attractions in extensile filaments lead, independent of the volume fraction, to anisotropic aggregates which translate and rotate ballistically. Lateral hydrodynamic repulsions in contractile filaments lead to microstructured states, where the degree of clustering increases with the volume fraction and the filament motion is always diffusive. Our results demonstrate that the interplay between active hydrodynamic flows and anisotropic excluded volume interactions provides a generic nonequilibrium mechanism for hierarchical self-assembly of active soft matter.

17.
J Neurochem ; 133(5): 640-52, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25753155

RESUMEN

The generation of differentiated and functional neurons is a complex process, which requires coordinated expression of several proteins and microRNAs (miRNAs). The present study using nerve growth factor (NGF)-differentiated PC12 cells led to the identification of miR-200, miR-221/222 and miR-34 families as major up-regulated miRNAs in fully differentiated neurons. Similar to PC12 cells, induction of miR-200 family was observed in differentiating neural stem cells, demonstrating a direct role of miR-200 family in neuronal differentiation. Over-expression of miR-200 induced neurite formation in PC12 cells and regulated neuronal markers in favour of differentiation. However, inhibition of miR-200 induced proliferation of PC12 cells. In differentiating PC12 cells and neural stem cells, an inverse relationship was observed between expression of reprogramming transcription factors (SOX2, KLF4, NANOG, OCT4 and PAX6) and miR-200. Over-expression of miR-200 in PC12 cells significantly down-regulated mRNA and protein levels of SOX2 and KLF4. Moreover, we observed two phases of dramatic down-regulation of miR-200 expression in developing rat brains correlating with periods of neuronal proliferation. In conclusion, our results indicate that increased expression of the miR-200 family promotes neuronal differentiation, while decreased expression of the miR-200 family promotes neuronal proliferation by targeting SOX2 and KLF4.


Asunto(s)
Diferenciación Celular/fisiología , Proliferación Celular , MicroARNs/fisiología , Neuronas/fisiología , Animales , Encéfalo/crecimiento & desarrollo , Recuento de Células , Supervivencia Celular , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/metabolismo , MicroARNs/biosíntesis , MicroARNs/genética , Factor de Crecimiento Nervioso/farmacología , Células PC12 , Ratas , Factores de Transcripción SOXB1/metabolismo , Transfección , Regulación hacia Arriba
18.
IUBMB Life ; 67(7): 506-13, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26177573

RESUMEN

The rapid outbreak of type-2 diabetes is one of the largest public health problems around the globe. Particularly, the developing nations are becoming the epicenters of cardiometabolic disorders owing to the change in lifestyle and diet preference besides genetic predisposition. Diabetes has become a major independent risk factor for cardiovascular diseases in South Asian countries including India. The pathogenesis of type-2 diabetes primarily initiates with inadequacy of pancreatic islet ß-cells to respond to chronic fuel surfeit and hence causing glycemic load, insulin resistance, and obesity. Urban Indian life is threatened with unhealthy high calorie diet and sedentary habits, and thus impairing the metabolic status of "thin-fat Indians" and rendering them more vulnerable to metabolic disorders. Furthermore, the metabolic dysfunction may be triggered off quite early in life due to poor maternal health and impairment in intrauterine programming and, particularly in rural India. The impaired fetal development affects the health status in later stage of life by promoting obesity, insulin resistance, type-2 diabetes, and cardiovascular complications. Therefore, the preventive and therapeutic approaches focus on a holistic strategy to improve maternal and child health, promote balanced diet and physical exercise in combination with pharmacological intervention of reducing/checking hyperglycemia, obesity, and cardiovascular complications. This review summarizes the epidemiology, mechanisms, and risk factors for diabetes and cardiovascular disorders with a focus on the Indian subcontinent.


Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/fisiopatología , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/prevención & control , Diabetes Gestacional/etiología , Dieta , Dislipidemias/etiología , Femenino , Humanos , India/epidemiología , Resistencia a la Insulina , Obesidad/etiología , Embarazo , Factores de Riesgo
19.
Haematologica ; 100(12): 1526-33, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26341739

RESUMEN

Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to glycoprotein1bα activates platelets. Lower concentrations of Hb (0.37-3 µM) significantly increase the phosphorylation of signaling adapter proteins, such as Lyn, PI3K, AKT, and ERK, and promote platelet aggregation in vitro. Higher concentrations of Hb (3-6 µM) activate the pro-apoptotic proteins Bak, Bax, cytochrome c, caspase-9 and caspase-3, and increase platelet clot formation. Increased plasma Hb activates platelets and promotes their apoptosis, and plays a crucial role in the pathogenesis of aggregation and development of the procoagulant state in hemolytic disorders. Furthermore, we show that in patients with paroxysmal nocturnal hemoglobinuria, a chronic hemolytic disease characterized by recurrent events of intravascular thrombosis and thromboembolism, it is the elevated plasma Hb or platelet surface bound Hb that positively correlates with platelet activation.


Asunto(s)
Apoptosis , Plaquetas/metabolismo , Hemoglobinas/metabolismo , Hemólisis , Activación Plaquetaria , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Plaquetas/patología , Femenino , Hemoglobinuria Paroxística/patología , Humanos , Masculino
20.
Cureus ; 16(7): e65729, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39211659

RESUMEN

Acute pancreatitis is a severe inflammatory condition that can lead to systemic repercussions, one of which is the development of hepatic steatosis (fatty liver). The accumulation of fat in liver cells can complicate the course of pancreatitis, exacerbating inflammation and causing additional metabolic disturbances. The presence of fatty liver in the context of acute pancreatitis can thus worsen the overall clinical picture, making management more challenging and potentially leading to further complications. Here, we discuss a rare case of a 34-year-old female who demonstrated the reversal of fatty liver following the improvement of acute pancreatitis. This case highlights the dynamic relationship between acute pancreatitis and hepatic steatosis, illustrating that effective management of pancreatitis can lead to significant improvements in associated conditions such as fatty liver.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA