Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
PLoS Pathog ; 18(4): e1009925, 2022 04.
Artigo em Inglês | MEDLINE | ID: covidwho-1808578

RESUMO

Early in the SARS-CoV-2 pandemic, there was a high level of optimism based on observational studies and small controlled trials that treating hospitalized patients with convalescent plasma from COVID-19 survivors (CCP) would be an important immunotherapy. However, as more data from controlled trials became available, the results became disappointing, with at best moderate evidence of efficacy when CCP with high titers of neutralizing antibodies was used early in infection. To better understand the potential therapeutic efficacy of CCP, and to further validate SARS-CoV-2 infection of macaques as a reliable animal model for testing such strategies, we inoculated 12 adult rhesus macaques with SARS-CoV-2 by intratracheal and intranasal routes. One day later, 8 animals were infused with pooled human CCP with a high titer of neutralizing antibodies (RVPN NT50 value of 3,003), while 4 control animals received normal human plasma. Animals were monitored for 7 days. Animals treated with CCP had detectable but low levels of antiviral antibodies after infusion. In comparison to the control animals, CCP-treated animals had similar levels of viral RNA in upper and lower respiratory tract secretions, similar detection of viral RNA in lung tissues by in situ hybridization, but lower amounts of infectious virus in the lungs. CCP-treated animals had a moderate, but statistically significant reduction in interstitial pneumonia, as measured by comprehensive lung histology. Thus overall, therapeutic benefits of CCP were marginal and inferior to results obtained earlier with monoclonal antibodies in this animal model. By highlighting strengths and weaknesses, data of this study can help to further optimize nonhuman primate models to provide proof-of-concept of intervention strategies, and guide the future use of convalescent plasma against SARS-CoV-2 and potentially other newly emerging respiratory viruses.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Anticorpos Neutralizantes , Antivirais , COVID-19/terapia , Humanos , Imunização Passiva , Macaca mulatta , RNA Viral , Soroterapia para COVID-19
2.
Indian J Med Microbiol ; 40(2): 228-230, 2022.
Artigo em Inglês | MEDLINE | ID: covidwho-1729827

RESUMO

PURPOSE: Health care workers [HCW] are at a higher risk of infection SARS CoV2 infection due to frequent and close contact to patients with COVID-19. METHODS: Serum samples from 500 HCW's were tested for SARS CoV2 IgG antibodies in October 2020. A questionnaire was used to collect demographic and clinical data. All these HCWs were tested for COVID-19, in 2nd week of September 2020, as a hospital policy. RESULTS: Anti SARS CoV2 antibodies were detected in 128/ 500 [25.6%] HCWs. A total of 195/ 500 [39%] enrolled cases had already tested positive for Covid-19 at least once in last six months by RT-PCR. Sixty eight percent of HCWs with previous COVID-19 positivity by RT- PCR tested positive for Anti SARS CoV2 antibodies, whereas only 2.76% of asymptomatic HCWs tested positive. Of 121 anti SARS-CoV-2 IgG positive persons, 70 [57.85%] had CT value â€‹< â€‹25. Low CT value and asymptomatic cases had a strong reverse statistically significant association with SARS CoV2 IgG antibody positivity. CONCLUSIONS: We report that sero-conversion rate in HCWs is similar to that in general population suggesting that preventive practices used in hospitals are satisfactory. Cases with low viral counts in respiratory sample and asymptomatic cases have lower rate of seroconversion.


Assuntos
COVID-19 , Anticorpos Antivirais , Pessoal de Saúde , Humanos , Imunoglobulina G , SARS-CoV-2 , Estudos Soroepidemiológicos , Centros de Atenção Terciária
3.
Cell Rep ; 37(5): 109942, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: covidwho-1471904

RESUMO

Anti-viral monoclonal antibody (mAb) treatments may provide immediate but short-term immunity from coronavirus disease 2019 (COVID-19) in high-risk populations, such as people with diabetes and the elderly; however, data on their efficacy in these populations are limited. We demonstrate that prophylactic mAb treatment blocks viral replication in both the upper and lower respiratory tracts in aged, type 2 diabetic rhesus macaques. mAb infusion dramatically curtails severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated stimulation of interferon-induced chemokines and T cell activation, significantly reducing development of interstitial pneumonia. Furthermore, mAb infusion significantly dampens the greater than 3-fold increase in SARS-CoV-2-induced effector CD4 T cell influx into the cerebrospinal fluid. Our data show that neutralizing mAbs administered preventatively to high-risk populations may mitigate the adverse inflammatory consequences of SARS-CoV-2 exposure.


Assuntos
Anticorpos Monoclonais/uso terapêutico , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Envelhecimento/imunologia , Animais , COVID-19/líquido cefalorraquidiano , COVID-19/complicações , COVID-19/imunologia , Complicações do Diabetes/imunologia , Complicações do Diabetes/virologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/imunologia , Feminino , Humanos , Ativação Linfocitária , Macaca mulatta , Masculino , Neurite (Inflamação)/imunologia , Neurite (Inflamação)/prevenção & controle , Profilaxia Pré-Exposição , Linfócitos T/imunologia , Replicação Viral/imunologia
4.
Clin Transl Gastroenterol ; 12(10): e00411, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: covidwho-1456553

RESUMO

INTRODUCTION: The adherence to a gluten-free diet (GFD) is a trending topic in the management of celiac disease. The aim of our study was to evaluate the diagnostic performance of urinary gluten immunogenic peptides (GIP) determination to detect gluten contamination of the GFD. METHODS: In study A, 25 healthy adults on a standard GFD performed 6 gluten challenges (0, 10, 50, 100, 500, and 1,000 mg) with quantification of urinary GIP before (T0) and during the following 24 hours. In study B, 12 participants on a gluten contamination elimination diet underwent urinary GIP determination at T0 and after challenge with 5 or 10 mg gluten. Urine GIP concentration was determined by an immunochromatographic assay. RESULTS: In study A, 51 of 150 baseline urine samples were GIP+ on GFD and 7 of 17 were GIP+ after the zero-gluten challenge, whereas only 55 of 81 were GIP+ after the 10-1,000 mg gluten challenges. There was no significant change in the 24-hour urinary GIP when increasing gluten from 10 to 1,000 mg. In study B, 24 of 24 baseline urine samples were GIP-, whereas 8 of 24 were GIP+ after 5 or 10 mg of gluten. DISCUSSION: Traces of gluten in the standard GFD may cause positivity of urinary GIP determination, whereas a false negativity is common after a gluten intake of 10-1,000 mg. Owing to the impossibility of standardizing the test in normal conditions, it seems unlikely that urinary GIP determination may represent a reliable tool to assess the compliance to the GFD of patients with celiac disease or other gluten-related disorders.


Assuntos
Doença Celíaca/dietoterapia , Doença Celíaca/urina , Dieta Livre de Glúten , Glutens/urina , Cooperação do Paciente , Peptídeos/urina , Adulto , Doença Celíaca/imunologia , Método Duplo-Cego , Feminino , Glutens/imunologia , Humanos , Imunoglobulina A/sangue , Masculino , Peptídeos/imunologia , Transglutaminases/imunologia
5.
New Gener Comput ; 39(3-4): 541-568, 2021.
Artigo em Inglês | MEDLINE | ID: covidwho-1391853

RESUMO

Novel Coronavirus (COVID-19) has become one of the deadliest pandemics that has affected almost all the nations in the world. Lockdown and systematic re-opening of shopping malls, offices, etc. is still one of the major weapons against this virus. However, the government and medical agencies take long time to reopen the places due to risks involved in this deadly virus. The delay to reopen places has resulted in sharp decline in the growth of economy. In this paper a current context aware framework is proposed which uses multiple inputs for a specific region to decide whether to open it or not. The proposed framework used series of deep neural network models to generate recommendations specific to a particular region. Most of the inputs are real-time and readily available with the government. The main aim is to develop framework which can be used in any kind of pandemic even in small region to easily contain it. However, it has been tested using opensource data available for COVID-19. Data was crawled from web for 22 districts of Haryana state of India. Experimental result proved the efficiency of proposed framework.

6.
PLoS Pathog ; 17(7): e1009688, 2021 07.
Artigo em Inglês | MEDLINE | ID: covidwho-1298083

RESUMO

There is an urgent need for effective therapeutic interventions against SARS-CoV-2, including new variants that continue to arise. Neutralizing monoclonal antibodies have shown promise in clinical studies. We investigated the therapeutic efficacy of a combination of two potent monoclonal antibodies, C135-LS and C144-LS that carry half-life extension mutations, in the rhesus macaque model of COVID-19. Twelve young adult macaques (three groups of four animals) were inoculated intranasally and intra-tracheally with a high dose of SARS-CoV-2 and 24 hours later, treated intravenously with a high (40 mg/kg) or low (12 mg/kg) dose of the C135-LS and C144-LS antibody combination, or a control monoclonal antibody. Animals were monitored for 7 days. Compared to the control animals, animals treated with either dose of the anti-SARS-CoV-2 antibodies showed similarly improved clinical scores, lower levels of virus replication in upper and lower respiratory tract, and significantly reduced interstitial pneumonia, as measured by comprehensive lung histology. In conclusion, this study provides proof-of-concept in support of further clinical development of these monoclonal antibodies against COVID-19 during early infection.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , COVID-19/terapia , Pulmão/patologia , SARS-CoV-2/imunologia , Replicação Viral , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/patologia , COVID-19/virologia , Modelos Animais de Doenças , Feminino , Pulmão/diagnóstico por imagem , Macaca mulatta , Masculino , Análise Multivariada , Radiografia , Sistema Respiratório/virologia , SARS-CoV-2/fisiologia , Fatores de Tempo , Resultado do Tratamento , Replicação Viral/imunologia
7.
Nat Commun ; 12(1): 541, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: covidwho-1044084

RESUMO

CD4 T follicular helper (Tfh) cells are important for the generation of durable and specific humoral protection against viral infections. The degree to which SARS-CoV-2 infection generates Tfh cells and stimulates the germinal center (GC) response is an important question as we investigate vaccine induced immunity against COVID-19. Here, we report that SARS-CoV-2 infection in rhesus macaques, either infused with convalescent plasma, normal plasma, or receiving no infusion, resulted in transient accumulation of pro-inflammatory monocytes and proliferating Tfh cells with a Th1 profile in peripheral blood. CD4 helper cell responses skewed predominantly toward a Th1 response in blood, lung, and lymph nodes. SARS-CoV-2 Infection induced GC Tfh cells specific for the SARS-CoV-2 spike and nucleocapsid proteins, and a corresponding early appearance of antiviral serum IgG antibodies. Collectively, the data show induction of GC responses in a rhesus model of mild COVID-19.


Assuntos
COVID-19/imunologia , Centro Germinativo/imunologia , SARS-CoV-2/imunologia , Células T Auxiliares Foliculares/imunologia , Células Th1/imunologia , Animais , Anticorpos Antivirais/sangue , COVID-19/terapia , Linhagem Celular , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Humoral/imunologia , Imunização Passiva , Imunogenicidade da Vacina/imunologia , Imunoglobulina G/sangue , Macaca mulatta , Masculino , Fosfoproteínas/imunologia , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero , Soroterapia para COVID-19
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA