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1.
Molecules ; 29(5)2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38474656

RESUMO

The SARS-CoV-2 virus and its mutations have affected human health globally and created significant danger for the health of people all around the world. To cure this virus, the human Angiotensin Converting Enzyme-2 (ACE2) receptor, the SARS-CoV-2 main protease (Mpro), and spike proteins were found to be likely candidates for the synthesis of novel therapeutic drug. In the past, proteins were capable of engaging in interaction with a wide variety of ligands, including both manmade and plant-derived small molecules. Pyrus communis L., Ginko bibola, Carica papaya, Syrian rue, and Pimenta dioica were some of the plant species that were studied for their tendency to interact with SARS-CoV-2 main protease (Mpro) in this research project (6LU7). This scenario investigates the geometry, electronic, and thermodynamic properties computationally. Assessing the intermolecular forces of phytochemicals with the targets of the SARS-CoV-2 Mpro spike protein (SP) resulted in the recognition of a compound, kaempferol, as the most potent binding ligand, -7.7 kcal mol-1. Kaempferol interacted with ASP-187, CYS-145, SER-144, LEU 141, MET-165, and GLU-166 residues. Through additional molecular dynamic simulations, the stability of ligand-protein interactions was assessed for 100 ns. GLU-166 remained intact with 33% contact strength with phenolic OH group. We noted a change in torsional conformation, and the molecular dynamics simulation showed a potential variation in the range from 3.36 to 7.44 against a 45-50-degree angle rotation. SAR, pharmacokinetics, and drug-likeness characteristic investigations showed that kaempferol may be the suitable candidate to serve as a model for designing and developing new anti-COVID-19 medicines.


Assuntos
COVID-19 , Proteases 3C de Coronavírus , Humanos , Animais , Cricetinae , Simulação de Acoplamento Molecular , Quempferóis , Ligantes , Simulação de Dinâmica Molecular , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Mesocricetus , Inibidores de Proteases
2.
Molecules ; 28(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38138581

RESUMO

In this study, for the first time, boron oxide nanoflake is analyzed as drug carrier for favipiravir using computational studies. The thermodynamic stability of the boron oxide and favipiravir justifies the strong interaction between both species. Four orientations are investigated for the interaction between the favipiravir and the B3O3 nanoflake. The Eint of the most stable orientation is -26.98 kcal/mol, whereas the counterpoise-corrected energy is -22.59 kcal/mol. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses are performed to obtain insights about the behavior and the types of interactions that occur between B3O3 nanoflake and favipiravir. The results indicate the presence of hydrogen bonding between the hydrogen in the favipiravir and the oxygen in the B3O3 nanoflake in the most stable complex (FAV@B3O3-C1). The electronic properties are investigated through frontier molecular orbital analysis, dipole moments and chemical reactivity descriptors. These parameters showed the significant activity of B3O3 for favipiravir. NBO charge analysis transfer illustrated the charge transfer between the two species, and UV-VIS analysis confirmed the electronic excitation. Our work suggested a suitable drug carrier system for the antiviral drug favipiravir, which can be considered by the experimentalist for better drug delivery systems.


Assuntos
Compostos de Boro , Teoria Quântica , Teoria da Densidade Funcional , Portadores de Fármacos
3.
J Mol Graph Model ; 125: 108611, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37660614

RESUMO

Traditionally, nanocones as a drug delivery material allow controlled drug delivery close to the target area while reducing the toxicity and generic accumulation associated with traditional intravenous injection methods. In the current study, density functional theory (DFT) is employed to investigate the therapeutic potential of carbon nanocone oxide (ONC) as a carrier with zidovudine drug for the treatment of human immunodeficiency virus (HIV). The electronic ground state and excited state were studied to evaluate the drug carrier potential of ONC and Zidovudine-ONC complex. The Frontier Molecular Orbitals (FMOs) and Molecular Electrostatic Potential (MEPs) revealed that the ONC carrier acts as a donor and zidovudine as an acceptor. The FMOs confirmed the interaction between drug and carrier stabilization energy by calculating chemical hardness, material softness, electronegativity, Ionization energy and electron affinity. The natural bond analysis (NBO), non-covalent interaction (NCI) and electron localization function (ELF) revealed the charge transfer between zidovudine and ONC. The density of state (DOS) and Charge Deposition analysis (CDA) provided the charge transfer. To study the excited state of zidovudine, transition density matrix (TDM), UV(Ultra-visible), IR (infrared), Raman, and NMR (Nuclear Magnetic Resonance) spectra of ONC and zidovudine-ONC complex have been plotted. The spectra showed a significant red shift in the zidovudine-ONC complex. Photoinduced electron studies (PET) showed fluorescence quenching because of the interaction between the drug and the carrier and provided a graphical explanation of the distinct excited state. All the results show that the ONC carrier has therapeutic potential as a zidovudine carrier for the treatment of Human Immunodeficiency Virus (HIV).


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Humanos , Zidovudina , Portadores de Fármacos , Óxidos
4.
J Mol Graph Model ; 123: 108517, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37235904

RESUMO

This study aimed to explore the potential of Host-Guest coupling with Nanocarrier graphyne (GPH) to enhance the bioavailability of the drug 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (LUM) for brain tumor therapy. The electronic, geometric, and excited-state properties of GPH, LUM, and the graphyne@1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea-complex (GPH@LUM-complex) were studied using DFT B3LYP/6-31G** level of theory. The results showed that the GPH@LUM-complex was stable with negative adsorption energy (-0.20 eV), and there was good interaction between GPH and LUM in the solvent phase. The weak interaction forces between the two indicated an easy release of the drug at the target site. The Frontier Molecular Orbitals (FMO), Charge Density Analysis (CDA), and Natural Bond Orbital (NBO) analysis supported LUM to GPH charge transfer during complex formation, and the Reduced Density Gradient (RDG) isosurfaces identified steric effects and non-bonded interactions. UV-visible examination showed the potential of the GPH@LUM-complex as a drug carrier with a blue shift of 23 nm wavelength in the electronic spectra. The PET process analysis revealed a fluorescence-quenching process, facilitating systematic drug delivery. The study concluded that GPH had potential as a carrier for delivering LUM, and different 2D nanomaterials could be explored for drug delivery applications. The theoretical study's findings may motivate researchers to investigate the practical applications of GPH@LUM-complex in oncology.


Assuntos
Neoplasias Encefálicas , Compostos de Nitrosoureia , Humanos
5.
Nutrients ; 14(3)2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-35276979

RESUMO

This review aims to define the effectiveness of the ketogenic diet (KD) for the management of sarcopenic obesity. As the combination of sarcopenia and obesity appears to have multiple negative metabolic effects, this narrative review discusses the effects of the ketogenic diet as a possible synergic intervention to decrease visceral adipose tissue (VAT) and fatty infiltration of the liver as well as modulate and improve the gut microbiota, inflammation and body composition. The results of this review support the evidence that the KD improves metabolic health and expands adipose tissue γδ T cells that are important for glycaemia control during obesity. The KD is also a therapeutic option for individuals with sarcopenic obesity due to its positive effect on VAT, adipose tissue, cytokines such as blood biochemistry, gut microbiota, and body composition. However, the long-term effect of a KD on these outcomes requires further investigations before general recommendations can be made.


Assuntos
Dieta Cetogênica , Microbioma Gastrointestinal , Sarcopenia , Composição Corporal , Humanos , Obesidade
6.
J Clin Med ; 11(3)2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35160222

RESUMO

There is a discrepancy between the patients requiring organ transplants and the donors available to meet that demand. Many patients die every year while on the waiting list, and there is a need to bridge this gap. For many years, medical practitioners have been apprehensive of using donor organs from donors who have tested positive for the Hepatitis C virus (HCV), and with good reason. HCV has been proven to be among the leading causes of liver diseases requiring liver transplants. Over the years, studies have been carried out to find a treatment for Hepatitis C. The advent of direct-acting antivirals revolutionized the medical world. These medication regimens have been proven to treat Hepatitis C in transplant patients effectively. This systematic review will examine how DAA treatments affect transplants of different organs from HCV-positive donors to HCV-negative recipients.

7.
Vaccines (Basel) ; 9(11)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34835300

RESUMO

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) created a global pandemic (COVID-19) that has resulted in massive health and economic losses. The current unavailability of treatments leaves vaccination as the only way to control this disease. There are four vaccines (Sinopharm, Pfizer-BioNTech, Sputnik, and AstraZeneca) available in Bahrain. This project aimed to study the most common side effects resulting from the first and second doses of these four vaccines. Data were collected through an online questionnaire answered by 311 individuals who received both doses of one of these four vaccines. The results of this study revealed that regardless of the vaccine identity, participants experienced more side effects from the second dose. Among the different side effects, pain at the site of injection was primarily observed after the first dose of the Pfizer vaccine (43%), which was followed by the AstraZeneca vaccine (31%). Moreover, fever was observed in participants after the first dose of the Sputnik vaccine (37%), while headache was mainly observed after the first dose of the Pfizer vaccine (32%). It is important to note that fatigue was observed after the first dose of all four vaccines but was reported by the highest proportion of respondents in the Pfizer group (28%). Interestingly, there are some side effects, such as pain at the site of injection, that are correlated with fever (r = 0.909). Similarly, headache is correlated with fever (r = 0.801) and pain at the site of injection (r = 0.868). Overall, it was observed that recipients of the Sinopharm vaccine reported the mildest side effects among all four vaccines. The crucial finding of this study is that the first and second dosage post-vaccination side effects were modest and predictable with no occurrences of hospitalization; this information can assist in lessening vaccine apprehension.

8.
Trials ; 22(1): 618, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526081

RESUMO

OBJECTIVES: Considering the therapeutic potential of honey and Nigella sativa (HNS) in coronavirus disease 2019 (COVID-19) patients, the objective of the study is defined to evaluate the prophylactic role of HNS. TRIAL DESIGN: The study is a randomized, placebo-controlled, adaptive clinical trial with parallel group design, superiority framework with an allocation ratio of 1:1 among experimental (HNS) and placebo group. An interim analysis will be done when half of the patients have been recruited to evaluate the need to adapt sample size, efficacy, and futility of the trial. PARTICIPANTS: All asymptomatic patients with hospital or community based COVID-19 exposure will be screened if they have had 4 days exposure to a confirmed case. Non-pregnant adults with significant exposure level will be enrolled in the study High-risk exposure (<6 feet distance for >10min without face protection) Moderate exposure (<6 feet distance for >10min with face protection) Subjects with acute or chronic infection, COVID-19 vaccinated, and allergy to HNS will be excluded from the study. Recruitment will be done at Shaikh Zayed Post-Graduate Medical Institute, Ali Clinic and Doctors Lounge in Lahore (Pakistan). INTERVENTION AND COMPARATOR: In this clinical study, patients will receive either raw natural honey (0.5 g) and encapsulated organic Nigella sativa seeds (40 mg) per kg body weight per day or empty capsule with and 30 ml of 5% dextrose water as a placebo for 14 days. Both the natural products will be certified for standardization by Government College University (Botany department). Furthermore, each patient will be given standard care therapy according to version 3.0 of the COVID-19 clinical management guidelines by the Ministry of National Health Services of Pakistan. MAIN OUTCOMES: Primary outcome will be Incidence of COVID-19 cases within 14 days of randomisation. Secondary endpoints include incidence of COVID-19-related symptoms, hospitalizations, and deaths along with the severity of COVID-19-related symptoms till 14th day of randomization. RANDOMISATION: Participants will be randomized into experimental and control groups (1:1 allocation ratio) via the lottery method. There will be stratification based on high risk and moderate risk exposure. BLINDING (MASKING): Quadruple blinding will be ensured for the participants, care providers and outcome accessors. Data analysts will also be blinded to avoid conflict of interest. Site principal investigator will be responsible for ensuring masking. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): 1000 participants will be enrolled in the study with 1:1 allocation. TRIAL STATUS: The final protocol version 1.4 was approved by institutional review board of Shaikh Zayed Post-Graduate Medical Complex on February 15, 2021. The trial recruitment was started on March 05, 2021, with a trial completion date of February 15, 2022. TRIAL REGISTRATION: Clinical trial was registered on February 23, 2021, www.clinicaltrials.gov with registration ID NCT04767087 . FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). With the intention of expediting dissemination of this trial, the conventional formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines.


Assuntos
COVID-19 , Mel , Nigella sativa , Adulto , Hospitais , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , SARS-CoV-2 , Resultado do Tratamento
9.
Artigo em Inglês | MEDLINE | ID: mdl-34069764

RESUMO

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in China in December 2019 and has become a pandemic that resulted in more than one million deaths and infected over 35 million people worldwide. In this study, a continent-wide analysis of COVID-19 cases from 31st December 2019 to 14th June 2020 was performed along with socio-economic factors associated with mortality rates as well as a predicted future scenario of COVID-19 cases until the end of 2020. METHODS: Epidemiological and statistical tools such as linear regression, Pearson's correlation analysis, and the Auto Regressive Integrated Moving Average (ARIMA) model were used in this study. RESULTS: This study shows that the highest number of cases per million population was recorded in Europe, while the trend of new cases is lowest in Africa. The mortality rates in different continents were as follows: North America 4.57%, Europe 3.74%, South America 3.87%, Africa 3.49%, Oceania and Asia less than 2%. Linear regression analysis showed that hospital beds, GDP, diabetes, and higher average age were the significant risk factors for mortality in different continents. The forecasting analysis since the first case of COVID-19 until 1st January 2021 showed that the worst scenario at the end of 2020 predicts a range from 0 to 300,000 daily new cases and a range from 0 to 16,000 daily new deaths. CONCLUSION: Epidemiological and clinical features of COVID-19 should be better defined, since they can play an import role in future strategies to control this pandemic.


Assuntos
COVID-19 , África , Ásia/epidemiologia , China/epidemiologia , Europa (Continente) , Previsões , Humanos , Morbidade , América do Norte , SARS-CoV-2 , Fatores Socioeconômicos , América do Sul
10.
Am J Transplant ; 19(9): 2533-2542, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30768838

RESUMO

The advent of direct-acting antiviral therapy for hepatitis C virus (HCV) has generated tremendous interest in transplanting organs from HCV-infected donors. We conducted a single-arm trial of orthotopic heart transplantation (OHT) from HCV-infected donors into uninfected recipients, followed by elbasvir/grazoprevir treatment after recipient HCV was first detected (NCT03146741; sponsor: Merck). We enrolled OHT candidates aged 40-65 years; left ventricular assist device (LVAD) support and liver disease were exclusions. We accepted hearts from HCV-genotype 1 donors. From May 16, 2017 to May 10, 2018, 20 patients consented for screening and enrolled, and 10 (median age 52.5 years; 80% male) underwent OHT. The median wait from UNOS opt-in for HCV nucleic-acid-test (NAT)+ donor offers to OHT was 39 days (interquartile range [IQR] 17-57). The median donor age was 34 years (IQR 31-37). Initial recipient HCV RNA levels ranged from 25 IU/mL to 40 million IU/mL, but all 10 patients had rapid decline in HCV NAT after elbasvir/grazoprevir treatment. Nine recipients achieved sustained virologic response at 12 weeks (SVR-12). The 10th recipient had a positive cross-match, experienced antibody-mediated rejection and multi-organ failure, and died on day 79. No serious adverse events occurred from HCV transmission or treatment. These short-term results suggest that HCV-negative candidates transplanted with HCV-infected hearts have acceptable outcomes.


Assuntos
Insuficiência Cardíaca/cirurgia , Transplante de Coração , Hepatite C/transmissão , Adulto , Idoso , Amidas , Antivirais/uso terapêutico , Benzofuranos/administração & dosagem , Carbamatos , Ciclopropanos , Feminino , Genótipo , Rejeição de Enxerto , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/virologia , Transplante de Coração/efeitos adversos , Coração Auxiliar , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Humanos , Imidazóis/administração & dosagem , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Quinoxalinas/administração & dosagem , RNA Viral/análise , Sulfonamidas , Resposta Viral Sustentada , Fatores de Tempo , Obtenção de Tecidos e Órgãos , Resultado do Tratamento , Carga Viral , Listas de Espera
11.
Transbound Emerg Dis ; 65(6): 2032-2038, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30051602

RESUMO

Peste des petits ruminants (PPR) is an endemic and highly infectious disease of several tropical countries, including Pakistan. Despite exhaustive vaccination, outbreaks are on the rise annually across different parts of the country. Clinical outcomes are largely employed to diagnose disease, while comprehensive genomic features of prevailing field strains of SRMV largely remain elusive. Here, we present comparative sequence-based phylogenomics of field strains from three districts representing different agro-livestock production systems during an emerging wave of outbreaks in 2015, together with the first complete genome sequencing of a strain from Pakistan. The analysis revealed clustering of study strain (SRMV/Lahore/UVAS/Pak/2015) to lineage IV, close to isolates characterized previously from India and China. Investigations of inter- and intralineage genetic distances showed a higher genetic distance between SRMV/Lahore/UVAS/Pak/2015 to lineage III viruses than lineages I and II. The characterized Pakistani strain also showed a high percentage of genetic distance from isolates originated from Nigerian and other African small ruminants. Based on these observations, an integrated cross-protection investigation is warranted in the future, not only to define the protective efficacy of currently applied vaccines, but also to continuously elucidate the genomic and evolutionary nature of circulating viruses in the country to achieve disease eradication by 2030.


Assuntos
Peste dos Pequenos Ruminantes/epidemiologia , Vírus da Peste dos Pequenos Ruminantes/genética , Animais , Surtos de Doenças/veterinária , Paquistão/epidemiologia , Filogenia , Sequenciamento Completo do Genoma
12.
Nutrients ; 8(8)2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27490566

RESUMO

The selectivity and beneficial effects of prebiotics are mainly dependent on composition and glycosidic linkage among monosaccharide units. This is the first study to use prebiotic galacto-oligosaccharides (GOS) that contains ß-1,6 and ß-1,3 glycosidic linkages and the novel combination of GOS and inulin in cancer prevention. The objective of the present study is to explore the role of novel GOS and inulin against various biomarkers of colorectal cancer (CRC) and the incidence of aberrant crypt foci (ACF) in a 1,2-dimethyl hydrazine dihydrochloride (DMH)-induced rodent model. Prebiotic treatments of combined GOS and inulin (57 mg each), as well as individual doses (GOS: 76-151 mg; inulin 114 mg), were given to DMH-treated animals for 16 weeks. Our data reveal the significant preventive effect of the GOS and inulin combination against the development of CRC. It was observed that inhibition of ACF formation (55.8%) was significantly (p ≤ 0.05) higher using the GOS and inulin combination than GOS (41.4%) and inulin (51.2%) treatments alone. This combination also rendered better results on short-chain fatty acids (SCFA) and bacterial enzymatic activities. Dose-dependent effects of prebiotic treatments were also observed on cecum and fecal bacterial enzymes and on SCFA. Thus, this study demonstrated that novel combination of GOS and inulin exhibited stronger preventive activity than their individual treatments alone, and can be a promising strategy for CRC chemoprevention.


Assuntos
Focos de Criptas Aberrantes/prevenção & controle , Anticarcinógenos/uso terapêutico , Neoplasias do Colo/prevenção & controle , Modelos Animais de Doenças , Inulina/uso terapêutico , Prebióticos , Trissacarídeos/uso terapêutico , 1,2-Dimetilidrazina , Focos de Criptas Aberrantes/metabolismo , Focos de Criptas Aberrantes/microbiologia , Focos de Criptas Aberrantes/patologia , Amônia/análise , Animais , Anticarcinógenos/administração & dosagem , Proteínas de Bactérias/metabolismo , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Ceco/enzimologia , Ceco/metabolismo , Ceco/microbiologia , Colo/metabolismo , Colo/microbiologia , Colo/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/microbiologia , Neoplasias do Colo/patologia , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/metabolismo , Fezes/química , Fezes/enzimologia , Fezes/microbiologia , Concentração de Íons de Hidrogênio , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Inulina/administração & dosagem , Masculino , Distribuição Aleatória , Ratos Wistar , Estereoisomerismo , Trissacarídeos/administração & dosagem , Trissacarídeos/química
13.
Virol J ; 11: 24, 2014 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-24512668

RESUMO

BACKGROUND: Hepatitis C virus (HCV) is highly infectious pathogen which is responsible for causing Hepatitis around 200 million individuals worldwide. In Pakistan, 4.7% of HCV prevalence has been reported and HCV genotype 3a has been found to be the major source of infection in Pakistan but still there is lack of information on distribution of HCV genotypes and viral load in various geographical regions of Pakistan. Therefore, current study was designed to determine distribution of HCV genotypes as well viral load in different areas of Punjab province of Pakistan. FINDINGS: A total of 995 serum samples were taken from those individuals in which antibodies against HCV were detected through ELISA, from different regions of Punjab i.e. Lahore 317(31.85%), Faisalabad 70(7.03%), Gujranwala 129(12.96%), Gujrat 106(10.65%), Sialkot 94(9.44%), Sargodha 60(6.03%), Mandibaha-ud-din 135(13.56%), Jhang 86(8.64%). Qualitative PCR was performed to determine viral load and genotyping was performed using Nested PCR. Chi-square test was used to determine the age and sex-wise prevalence of HCV. Out of 995 samples, 888 samples were found positive for HCV RNA. In all regions, genotype 3a showed highest prevalence (82.81%) followed by genotype 1 (3.41%), mixed genotypes (2.41%), genotype 2 (0.50%), genotype 5 (0.1%) and unclassified genotypes (10.75%). Viral load in 29.5% patients infected with genotype 3a was less than 600,000 IU/mL, while it was between 600,000-800,000 IU/mL in 27.9% patients and 25.22% patients had more than 800,000 IU/mL viral load. CONCLUSION: HCV genotype 3a is the most prevalent genotype in various regions of Punjab. Viral load of HCV patients in these different regions of Punjab are reported for the first time. Moreover, based upon these results the Patients having viral load below 800,000 IU/mL would be expected to show better response of anti-HCV therapy.


Assuntos
Variação Genética , Hepacivirus/classificação , Hepacivirus/isolamento & purificação , Hepatite C/epidemiologia , Hepatite C/virologia , Carga Viral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Genótipo , Hepacivirus/genética , Anticorpos Anti-Hepatite C/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Paquistão/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , Adulto Jovem
14.
Indian J Virol ; 24(3): 342-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24426296

RESUMO

Several outbreaks of avian influenza (AI) caused by H9N2 subtype, have been reported in the poultry industry during 1990 around the globe. Currently, H9N2 are endemic in the large area of Middle and Far East, including Pakistan. Since H9N2 AI viruses are sporadically reported from humans, extensive incidence of H9N2 in poultry imposes a great risk for human health. In this context, continuous monitoring of the poultry and determining the genetic nature of these viruses are fundamental to predict any future threat. Thus gene sequences of one isolate of H9N2, isolated from commercial poultry flocks, were analyzed. The results of this investigation, based on hemagglutinin (HA), neuraminidase (NA) and non-structural genes, showed that Pakistani H9N2 isolates are closely related to each other and to other H9N2 isolates from the Middle East. However, several unusual substitutions with unknown functional consequences were observed in HA and NA proteins and thus warrant further investigations for their possible role in viral biology. In conclusion, these findings provide information regarding the genetic nature of H9N2 avian influenza viruses in Pakistani poultry and necessitate the sequencing of more H9N2 viruses from both naturally infected and vaccinated flocks.

15.
Gastroenterology ; 143(1): 223-233.e9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22503792

RESUMO

BACKGROUND & AIMS: The development of vaccines and other strategies to prevent hepatitis C virus (HCV) infection is limited by rapid viral evasion. HCV entry is the first step of infection; this process involves several viral and host factors and is targeted by host-neutralizing responses. Although the roles of host factors in HCV entry have been well characterized, their involvement in evasion of immune responses is poorly understood. We used acute infection of liver graft as a model to investigate the molecular mechanisms of viral evasion. METHODS: We studied factors that contribute to evasion of host immune responses using patient-derived antibodies, HCV pseudoparticles, and cell culture-derived HCV that express viral envelopes from patients who have undergone liver transplantation. These viruses were used to infect hepatoma cell lines that express different levels of HCV entry factors. RESULTS: By using reverse genetic analyses, we identified altered use of host-cell entry factors as a mechanism by which HCV evades host immune responses. Mutations that alter use of the CD81 receptor also allowed the virus to escape neutralizing antibodies. Kinetic studies showed that these mutations affect virus-antibody interactions during postbinding steps of the HCV entry process. Functional studies with a large panel of patient-derived antibodies showed that this mechanism mediates viral escape, leading to persistent infection in general. CONCLUSIONS: We identified a mechanism by which HCV evades host immune responses, in which use of cell entry factors evolves with escape from neutralizing antibodies. These findings advance our understanding of the pathogenesis of HCV infection and might be used to develop antiviral strategies and vaccines.


Assuntos
Anticorpos Neutralizantes/imunologia , Hepacivirus/genética , Hepatite C/genética , Internalização do Vírus , Linhagem Celular Tumoral , Hepacivirus/imunologia , Hepatite C/imunologia , Humanos , Masculino , Mutação , Transplantes/virologia
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