Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 137
Filtrar
1.
Lancet ; 403(10434): 1351-1361, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38490230

RESUMEN

BACKGROUND: The current standard of care of screening and referring patients for treatment for symptoms, such as depression, pain, and fatigue, is not effective. This trial aimed to test the efficacy of an integrated screening and novel stepped collaborative care intervention versus standard of care for patients with cancer and at least one of the following symptoms: depression, pain, or fatigue. METHODS: This randomised, parallel, phase 3 trial was conducted in 29 oncology outpatient clinics associated with the UPMC Hillman Cancer Center in the USA. Patients (aged ≥21 years) with any cancer type and clinical levels of depression, pain, or fatigue (or all of these) were eligible. Eligible family caregivers were aged 21 years or older and providing care to a patient diagnosed with cancer who consented for this study. Patients were randomly assigned (1:1) to stepped collaborative care or standard of care using a central, permuted block design (sizes of 2, 4, and 6) stratified by sex and prognostic status. The biostatistician, oncologists, and outcome assessors were masked to treatment assignment. Stepped collaborative care was once-weekly cognitive behavioural therapy for 50-60 min from a care coordinator via telemedicine (eg, telephone or videoconferencing). Pharmacotherapy for symptoms might be initiated or changed if recommended by the treatment team or preferred by the patient. Standard of care was screening and referral to a health-care provider for treatment of symptoms. The primary outcome was health-related quality of life in patients at 6 months. Maintenance of the treatment benefits was assessed at 12 months. Participants included in the primary analysis were per intention to treat, which included patients missing one or both follow-up assessments. This trial was registered with ClinicalTrials.gov (NCT02939755). FINDINGS: Between Dec 5, 2016, and April 8, 2021, 459 patients and 190 family caregivers were enrolled. 222 patients were assigned to standard of care and 237 to stepped collaborative care. Of 459 patients, 201 (44%) were male and 258 (56%) were female. Patients in the stepped collaborative care group had a greater 0-6-month improvement in health-related quality of life than patients in the standard-of-care group (p=0·013, effect size 0·09). Health-related quality of life was maintained for the stepped collaborative care group (p=0·74, effect size 0·01). Patients in the stepped collaborative care group had greater 0-6-month improvements than the standard-of-care group in emotional (p=0·012), functional (p=0·042), and physical (p=0·033) wellbeing. No adverse events were reported by patients in either group and deaths were considered unrelated to the study. INTERPRETATION: An integrated screening and novel stepped collaborative care intervention, compared with the current standard of care, is recommended to improve health-related quality of life. The findings of this study will advance the implementation of guideline concordant care (screening and treatment) and has the potential to shift the practice of screening and treatment paradigm nationwide, improving outcomes for patients diagnosed with cancer. FUNDING: US National Cancer Institute.


Asunto(s)
Cuidadores , Neoplasias , Femenino , Humanos , Masculino , Fatiga , Neoplasias/diagnóstico , Neoplasias/terapia , Dolor , Calidad de Vida , Resultado del Tratamiento , Adulto Joven , Adulto
7.
J Chem Theory Comput ; 19(22): 8245-8257, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37947833

RESUMEN

Lipid membrane remodeling, crucial for many cellular processes, is governed by the coupling of membrane structure and shape fluctuations. Given the importance of the ∼ nm length scale, details of the transition intermediates for conformational change are not fully captured by a continuum-mechanical description. Slow dynamics and the lack of knowledge of reaction coordinates (RCs) for biasing methods pose a challenge for all-atom (AA) simulations. Here, we map system dynamics on Langevin dynamics in a normal mode space determined from an elastic network model representation for the lipid-water Hamiltonian. AA molecular dynamics (MD) simulations are used to determine model parameters, and Langevin dynamics predictions for bilayer structural, mechanical, and dynamic properties are validated against MD simulations and experiments. Transferability to describe the dynamics of a larger lipid bilayer and a heterogeneous membrane-protein system is assessed. A set of generic RCs for pore formation in two tensionless bilayers is obtained by coupling Langevin dynamics to the underlying energy landscape for membrane deformations. Structure evolution is carried out by AA MD, wherein the generic RCs are used in a path metadynamics or an umbrella sampling simulation to determine the thermodynamics of pore formation and its molecular determinants, such as the role of distinct bilayer motions, lipid solvation, and lipid packing.


Asunto(s)
Membrana Dobles de Lípidos , Simulación de Dinámica Molecular , Membrana Dobles de Lípidos/química , Entropía , Termodinámica , Agua/química
8.
Org Biomol Chem ; 21(45): 9054-9060, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37937510

RESUMEN

The development of artificial molecular machines is a challenging endeavor. Herein, we have synthesized a series of bispidine diamides D1-D6 that exhibit rotation reminiscent of a motor motion. Dynamic NMR, X-ray diffraction, quantum mechanical calculations, and molecular dynamics simulations provided insights into their rotational dynamics. All the diamides D1-D6 exhibited mutually independent rotation around the two bispidine arms. However, the rate of rotation and the presence or absence of directionality in amide bond rotation were found to depend on the solvent, temperature, and nature of substitution on the amide carbonyl. These engineered systems may aid in the development of biologically relevant synthetic molecular motors. Studies on homochiral and heterochiral bispidine-peptides revealed that the direction of rotation can be controlled by chirality and the nature of the amino acid.

10.
Sci Rep ; 13(1): 14281, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37653001

RESUMEN

More than six and half million people have died as a result of the COVID-19 pandemic till Dec 2022. Vaccination is the most effective means to prevent mortality and infection attributed to COVID-19. Identifying public attitudes and perceptions on COVID-19 vaccination is essential to strengthening the vaccination programmes. This study aims to identify attitudes and perceptions of twitter users towards COVID-19 vaccinations in four different countries. A sentiment analysis of 663,377 tweets from October 2020 to September 2022 from four different countries (i.e., India, South Africa, UK, and Australia) was conducted. Text mining using roBERTA (Robustly Optimized Bert Pretraining approach) python library was used to identify the polarity of people's attitude as "negative", "positive" or "neutral" based on tweets. A sample of 2000 tweets (500 from each country) were thematically analysed to explore the people's perception concerning COVID-19 vaccines across the countries. The attitudes towards COVID-19 vaccines varied by countries. Negative attitudes were observed to be highest in India (58.48%), followed by United Kingdom (33.22%), Australia (31.42%) and South Africa (28.88%). Positive attitudes towards vaccines were highest in the United Kingdom (21.09%). The qualitative analysis yielded eight themes namely (i) vaccine shortages, (ii) vaccine side-effects, (iii) distrust on COVID-19 vaccines, (iv) voices for vaccine equity, (v) awareness about vaccines, (vi) myth busters, (vii) vaccines work and (viii) vaccines are safe. The twitter discourse reflected the evolving situation of COVID-19 pandemic and vaccination strategies, lacunae and positives in the respective countries studied.


Asunto(s)
COVID-19 , Medios de Comunicación Sociales , Humanos , Vacunas contra la COVID-19 , Pandemias , COVID-19/epidemiología , COVID-19/prevención & control , Vacunación
11.
J Infect Dev Ctries ; 17(7): 1037-1040, 2023 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-37515795

RESUMEN

Cyclospora cayetanensis, a recently described coccidian parasite causes severe gastroenteric disease worldwide. Limited studies are found on the incidence of C. cayetanensis infection from India; hence remains largely unknown. To date, no case of cyclosporiasis from eastern India has been reported. In this study, we described an incidental case of C. cayetanensis in a 30 years old Bengali female patient with no travel history from eastern India. In June 2022, the patient presented with a history of diarrhoea persisting for more than two months with continuous passage foul smelling stools for which she took multiple antibiotics that were ineffective. There were no Salmonella, Shigella, or Vibrio-like organisms in the patient's faecal sample, and Toxin A/B of Clostridium difficile was also not detected by ELISA. The patient was HIV-negative. Finally, UV autofluorescence and DNA-based diagnosis confirmed the presence of C. cayetanensis, and the treatment with a combination of appropriate antibiotics was successful. This case report could raise awareness about C. cayetanensis associated diarrhoeal cases in India.


Asunto(s)
Cyclospora , Ciclosporiasis , Humanos , Femenino , Adulto , Ciclosporiasis/diagnóstico , Ciclosporiasis/tratamiento farmacológico , Ciclosporiasis/epidemiología , Incidencia , Diarrea/epidemiología , Diarrea/parasitología , Antibacterianos/uso terapéutico , Heces/parasitología , India/epidemiología
12.
Environ Sci Pollut Res Int ; 30(38): 88450-88462, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37436617

RESUMEN

This research focused on the application of a fixed bed column filled with immobilized titanium oxide-loaded almond shell carbon (TiO2@ASC) for the treatment of leachate. The adsorption performance of synthesized TiO2@ASC in fixed bed column is analyzed using adsorption experiments and modeling study. The characteristics of synthesized materials are determined by several instrumental techniques like BET, XRD, FTIR, and FESEM-EDX. The flow rate, initial concentration of COD and NH3-N, and bed height were optimized to determine the effectiveness of leachate treatment. The linear bed depth service time (BDST) plots equations with a correlation coefficient of greater than 0.98 confirmed the model's accuracy for COD and NH3-N adsorption in column structure. The adsorption process was found to be well predicted by an artificial neural network (ANN) model with a root mean square error of 0.0172 and 0.0167 for COD and NH3-N reduction, respectively. The immobilized adsorbent was regenerated using HCl and was found to be reusable for up to three cycles, promoting material sustainability. This study is aimed to contribute towards SDG 6 and SDG11 by United Nations Sustainable Development Goals.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Contaminantes Químicos del Agua/análisis , Carbón Orgánico , Titanio , Adsorción , Purificación del Agua/métodos
13.
Am J Otolaryngol ; 44(6): 103975, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37478538

RESUMEN

BACKGROUND: COVID-associated Rhino-Orbito-Cerebral Mucormycosis (CAROM) appeared as an epidemic in India during the second wave of the COVID-19 pandemic during the months of March to May 2021. Though many reports have highlighted cross sectional and short-term attributes related to CAROM, long term follow up data is sparse. OBJECTIVE: This report aims to analyze the follow-up outcomes in consecutive patients presenting to us during the epidemic. PATIENTS AND METHODS: This was an ambispective observational analytical study, recruiting the consecutive patients admitted to our tertiary care centre during the period of the CAROM epidemic. The mortality rate during the follow-up and various factors affecting survival were studied using univariable and multivariable statistics with the Stata 14.0 software. RESULTS: Of the 189 patients studied, eight were lost to follow-up. The outcome analysis was performed for the 181 patients. 93.6 % (162/173) of the patients had diabetes. The All-cause mortality was 45 % (81/181), while the ROCM-specific mortality was found to be 24 % (46/181) at a median follow-up of 176 days (IQR: 21-217 days). With univariable analysis, increasing age, higher serum IL-6 levels, presence of additional comorbidities (in addition to Diabetes and hypertension), bilateral disease, skin necrosis, palatal involvement, infratemporal fossa involvement, and impaired vision/ocular movements were found to be associated with increased mortality. However, on multivariable analysis, only 1) increasing age, 2) raised serum IL-6 levels, and 3) bilateral disease were predictive of increased mortality. Surgical debridement (endoscopic, palatal removal, orbital exenteration, neurosurgical intervention) was associated with significantly reduced mortality on both univariable and multivariable analysis. CONCLUSION: Our intermediate-term follow-up data showed advanced age at presentation, raised IL-6 levels, and bilateral sinonasal involvement to be predictive of increased mortality, while surgical debridement is significantly protective from mortality in CAROM patients.


Asunto(s)
COVID-19 , Diabetes Mellitus , Mucormicosis , Enfermedades Orbitales , Humanos , Preescolar , Estudios Transversales , Interleucina-6 , Pandemias , Enfermedades Orbitales/etiología
14.
Proteins ; 91(9): 1222-1234, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37283297

RESUMEN

The RNA-dependent RNA polymerase (RdRp) complex of SARS-CoV-2 lies at the core of its replication and transcription processes. The interfaces between holo-RdRp subunits are highly conserved, facilitating the design of inhibitors with high affinity for the interaction interface hotspots. We, therefore, take this as a model protein complex for the application of a structural bioinformatics protocol to design peptides that inhibit RdRp complexation by preferential binding at the interface of its core subunit nonstructural protein, nsp12, with accessory factor nsp7. Here, the interaction hotspots of the nsp7-nsp12 subunit of RdRp, determined from a long molecular dynamics trajectory, are used as a template. A large library of peptide sequences constructed from multiple hotspot motifs of nsp12 is screened in-silico to determine sequences with high geometric complementarity and interaction specificity for the binding interface of nsp7 (target) in the complex. Two lead designed peptides are extensively characterized using orthogonal bioanalytical methods to determine their suitability for inhibition of RdRp complexation. Binding affinity of these peptides to accessory factor nsp7, determined using a surface plasmon resonance (SPR) assay, is slightly better than that of nsp12: dissociation constant of 133nM and 167nM, respectively, compared to 473nM for nsp12. A competitive ELISA is used to quantify inhibition of nsp7-nsp12 complexation, with one of the lead peptides giving an IC50 of 25µM . Cell penetrability and cytotoxicity are characterized using a cargo delivery assay and MTT cytotoxicity assay, respectively. Overall, this work presents a proof-of-concept of an approach for rational discovery of peptide inhibitors of SARS-CoV-2 protein-protein interactions.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Péptidos/farmacología , Secuencia de Aminoácidos , ARN Polimerasa Dependiente del ARN
15.
Transpl Infect Dis ; 25 Suppl 1: e14072, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37260056

RESUMEN

BACKGROUND: Infections by multidrug-resistant organisms (MDRO) are a major hurdle in hematopoietic stem-cell transplants (HSCTs). Conditioning regimens lead to mucosal barrier injury, which in-turn leads to transmigration of gut bacteria and sepsis. Pre-transplant stool and throat surveillance cultures can guide empirical antibiotic policy during the neutropenic period. In this paper, we document colonization with MDRO in pre-transplant surveillance cultures and the correlation with bloodstream infections in HSCT patients and analyze transplant outcomes with respect to these infections. METHODS: A single-center, retrospective study on HSCT was performed between January 2021 and December 2021. The incidence of bacterial infections, percentage of MDROs, correlation with pre-transplant stool/throat surveillance cultures, and their impact on overall 100-day and post-100-day to 6-month post-transplant survival were analyzed. RESULTS: Sixty-four patients were included in the study. Pre-transplant stool surveillance cultures were positive for MDRO in 85.9% of patients. Almost half (48.5%) of the isolates were positive for carbapenemase-producing genes (mainly New Delhi metallo-beta-lactamase-1 [NDM-1] and oxacillinase-48 [OXA-48]). Eighteen patients (18/64, 28%) had a positive blood culture for MDRO in the peri-engraftment neutropenic period. Correlation between surveillance and blood cultures was seen in 61% (11/18) of patients. All-cause mortality was 14.1% (9/64) and 25% (16/64) in patients at 100 days and 6 months post-HSCT, respectively. The 100-day and post-100-day all-cause mortality rates were higher in patients with Gram-negative MDRO bloodstream infections (p < .012 and <.008, respectively). CONCLUSION: MDRO infections can adversely affect HSCT outcomes. Pre-transplant stool and throat surveillance cultures may guide empirical antibiotic policy and lead to favorable transplant outcomes.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Neoplasias , Sepsis , Humanos , Farmacorresistencia Bacteriana Múltiple , Estudios Retrospectivos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Sepsis/tratamiento farmacológico
16.
Infect Prev Pract ; 5(2): 100275, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36915471

RESUMEN

Background: Trend analysis of bacteraemias caused by multi-drug resistant (MDR) and extensively drug resistant (XDR) bacteria helps to assess efficacy of infection prevention and control (IPC) practices. Data on the trends of MDR and XDR bacteraemias are lacking from cancer patients in India. Aims: To report antibiotic resistance rates over time in bacteraemias and to assess the effect of IPC practices where patient isolation facilities were limited on the rates and trends of MDR and XDR bacteraemias from a cancer centre in eastern India. Methods: A retrospective observational study was conducted in a specialist cancer hospital in India from 2011 to 2021. The study included both patients with haematological and solid organ malignancy. Data on blood cultures and surveillance culture samples were analysed. Blood cultures were processed using BACT/ALERT® (bioMérieux, Marcy-l'Étoile, France) and the identification and antibiotic susceptibilities of bacteria were performed using VITEK® 2 (bioMérieux, Marcy-l'Étoile, France). Surveillance cultures for MDR/XDR bacteria were performed on a subset of patients and processed based on a modified method described previously. Findings: 3rd-generation cephalosporin-resistant Gram negative bacilli were the commonest cause of MDR bacteraemia (57.6%) followed by carbapenem resistant organisms (CRO) (35.7%). Bacteraemias caused by vancomycin-resistant enterococci (VRE), meticillin-resistant Staphylococcus aureus (MRSA) and colistin-resistant Gram negative bacilli were responsible for 1.3%, 2.3% and 3.0% of laboratory confirmed bloodstream infections (BSI) respectively. The ranges of the rates of MDR/XDR BSI per 1000 in-patients during the study period were: MRSA (1-1.18), VRE (0-0.88), 3rd generation cephalosporin-resistant Gram negative bacilli (10.10-20.32), CRO (5.05-13.07) and colistin-resistant Gram negative bacilli (E. coli, Klebsiella, Pseudomonas aeruginosa, Acinetobacter spp (0-1.3). Surveillance cultures collected from a subset of patients showed ranges of MRSA detection in 0-2.11%, VRE in 1.67%-7.49%, 3rd generation cephalosporin-resistant Gram negative bacilli in 55%-89.91% and carbapenem resistant Gram negative bacilli in 18.33%-31.11% of patients. Conclusion: This is one of few studies providing trend data for MDR/XDR bacteraemia rates among cancer patients in India over a decade. In a high prevalence setting it was possible to keep the rates of MDR/XDR bacteraemia controlled with IPC strategies and without adequate isolation facilities. The results are of potential interest to policy makers, IPC specialists and clinicians.

17.
Indian J Med Microbiol ; 41: 104-110, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36244851

RESUMEN

PURPOSE: Despite COVID vaccination with ChAdOx1 ncov-19 (COVISHIELD®) (ChAdOx1 ncov-19) a large number of healthcare workers (HCWs) were getting infected in wave-2 of the pandemic in a cancer hospital of India. It was important therefore to determine the genotypes responsible for vaccine breakthrough infections. METHODS & OBJECTIVES: Retrospective observational study of HCWs. Whole genome sequencing of SARS CoV-2 using Illumina NovaSeq was done. Mutations from both waves were compared to identify genomic correlates of transmissibility and vaccine breakthrough infections. RESULTS: Vaccine breakthrough infections were seen in 127 HCWs out of 1806 fully vaccinated staff (7.03%). Median number of HCWs infected per day in wave-1 was 0.92 versus 3.25 in wave-2. Majority of wave-1 samples belonged to B.1 and B.1.1 lineage. Variant of concern- Delta variant (90%), and variant of interest- Kappa variant (10%), was seen in only wave-2 samples. Total mutation observed in wave-2 samples (median â€‹= â€‹44) was 1.8 times than wave-1 sample (median â€‹= â€‹24). Spike protein in wave-2 samples had 13 non-synonymous mutation as compared to 8 seen in wave-1 samples. E484Q-vaccine escape mutant was detected in five samples of wave-2; T478K - highly infectious mutation was seen in 31 samples of wave-2. We identified a novelcoding disruptive in-frame deletion (c.467_472delAGTTCA, p. Glu156_Arg158delinsGly) in the Spike protein. This mutation was seen only in wave-2 (78%, n â€‹= â€‹39) samples. CONCLUSION: The circulating virus strains in wave-2 infections demonstrated a greater degree of infectivity. There was a significant change in the genotypes observed in wave-1 and wave-2 infections along with almost twice the number of mutations. We noted that vaccine breakthrough infections (although mostly mild).


Asunto(s)
COVID-19 , Enfermedades Transmisibles , Neoplasias , Humanos , Instituciones Oncológicas , Epidemiología Molecular , SARS-CoV-2 , ChAdOx1 nCoV-19 , Glicoproteína de la Espiga del Coronavirus , Infección Irruptiva , Genómica , Personal de Salud , India , Complicaciones Posoperatorias
18.
Natl Med J India ; 35(3): 132-137, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36461870

RESUMEN

Background There was a dramatic rise in the incidence of rhino-orbito-cerebral mucormycosis associated with the 2021 Covid-19 wave in India. We aim to document the demographic characteristics and risk factors of a consecutive cohort of inpatients with Covid-19-associated rhino-orbito-cerebral mucormycosis (CAROM) during the surge of April-June 2021. Methods We included all patients of CAROM treated at our tertiary referral facility from 1 April to 14 June 2021. We prospectively gathered details with regard to Covid-19 illness and treatment, CAROM presentation, comorbid conditions and risk factors. Results Our prospective cohort consisted of 200 consecutive patients, of which 146 (73%) patients tested positive on the Covid-19 RT-PCR test at presentation. CAROM occurred concurrent with the Covid-19 infection in 86%, and delayed CAROM after seeming recovery from Covid-19 was seen in 14%. Covid-19 was classified as mild, moderate and severe in 54%, 33% and 13%. The surge of CAROM followed the population peak of Covid-19 infections by about 3 weeks. Advanced disease at presentation was frequent with ocular involvement in 56.6% (111/196) and central nervous system involvement in 20% (40/199). One or more comorbid conditions were identified in 191/200 (95.5%) patients. The dominant associations were with diabetes (189/200; 94.5%) and uncontrolled hyper-glycaemia (122/133; 91.7%), recent steroid use (114/ 200; 57%), which was often considered as inappropriate in dosage or duration, lymphopenia (142/176; 80.7%), and increased ferritin levels (140/160; 87.5%). No evidence supported the role of previous oxygen therapy or previous nasal swab testing as risk factors for CAROM. Conclusion The inpatient volumes of CAROM were noted to parallel the Covid-19 incidence curve by about 3 weeks. Covid-19 infection may directly predispose to CAROM by way of lymphopenia and increased ferritin levels. Uncontrolled hyperglycaemia is identified as a near-invariable association. Recent steroid use is noted as very frequent and was often received in excess of treatment advisories.


Asunto(s)
COVID-19 , Linfopenia , Mucormicosis , Humanos , Mucormicosis/epidemiología , Pacientes Internos , Estudios Prospectivos , COVID-19/epidemiología , Factores de Riesgo , Demografía , Ferritinas , Esteroides
19.
BMJ Case Rep ; 15(11)2022 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-36357101

RESUMEN

A man in his early 80s presented to the otorhinolaryngology department with progressively worsening dysphagia to solids and a recent episode of difficulty breathing accompanied by a very brief expulsion of a solid mass from the mouth. Based on the endoscopic appearance of a fatty lesion of an elongated mass with a thick stalk on the posterior pharyngeal wall, a diagnosis of the benign fibrovascular polyp was given after clinical and radiological correlation. The pharyngeal polyp was resected at the base of its pedicle by transoral endoscopy with a thunder beat vessel sealing device. Histopathological examination of the mass revealed a well-differentiated liposarcoma composed of mature adipocytes. Following surgical excision, the patient made a full recovery. This case signifies the integrated role of preoperative biopsy, new surgical technologies and targeted therapies in managing pharyngoesophageal polyps.


Asunto(s)
Trastornos de Deglución , Neoplasias Esofágicas , Lipoma , Liposarcoma , Pólipos , Masculino , Humanos , Neoplasias Esofágicas/diagnóstico por imagen , Neoplasias Esofágicas/cirugía , Liposarcoma/diagnóstico por imagen , Liposarcoma/cirugía , Pólipos/patología
20.
Mol Pharm ; 19(11): 3770-3783, 2022 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-36173709

RESUMEN

We have developed a multi-level virtual screening protocol to identify lead molecules from the FDA inactives database that can inhibit insulin aggregation. The method is based on the presence of structural and interaction specificity in non-native aggregation pathway protein-protein interactions. Some key challenges specific to the present problem, when compared with native protein association, include structural heterogeneity of the protein species involved, multiple association pathways, and relatively higher probability of conformational rearrangement of the association complex. In this multi-step method, the inactives database was first screened using the dominant pharmacophore features of previously identified molecules shown to significantly inhibit insulin aggregation nucleation by binding to its aggregation-prone conformers. We then performed ensemble docking of several low-energy ligand conformations on these aggregation-prone conformers followed by molecular dynamics simulations and binding affinity calculations on a subset of docked complexes to identify a final set of five potential lead molecules to inhibit insulin aggregation nucleation. Their effect on aggregation inhibition was extensively investigated by incubating insulin under aggregation-prone aqueous buffer conditions (low pH, high temperature). Aggregation kinetics were characterized using size exclusion chromatography and Thioflavin T fluorescence assay, and the secondary structure was determined using circular dichroism spectroscopy. Riboflavin provided the best aggregation inhibition, with 85% native monomer retention after 48 h incubation under aggregation-prone conditions, whereas the no-ligand formulation showed complete monomer loss after 36 h. Further, insulin incubated with two of the screened inactives (aspartame, riboflavin) had the characteristic α-helical dip in CD spectra, while the no-ligand formulation showed a change to ß-sheet rich conformations.


Asunto(s)
Ensayos Analíticos de Alto Rendimiento , Insulina , Insulina/química , Ligandos , Estructura Secundaria de Proteína , Insulina Regular Humana , Riboflavina , Dicroismo Circular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...