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1.
Crit Rev Toxicol ; : 1-24, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38868996

RESUMO

Over the past several decades, there have been many epidemiology studies on talc and cancer published in the scientific literature, and several reviews and meta-analyses of talc and respiratory, female reproductive, and stomach cancers, specifically. To help provide a resource for the evaluation of talc as a potential human carcinogen, we applied a consistent set of examination methods and criteria for all epidemiology studies that examined the association between talc exposure (by various routes) and cancers (of various types). We identified 30 cohort, 35 case-control, and 12 pooled studies that evaluated occupational, medicinal, and personal-care product talc exposure and cancers of the respiratory system, the female reproductive tract, the gastrointestinal tract, the urinary system, the lymphohematopoietic system, the prostate, male genital organs, and the central nervous system, as well as skin, eye, bone, connective tissue, peritoneal, and breast cancers. We tabulated study characteristics, quality, and results in a systematic manner, and evaluated all cancer types for which studies of at least three unique populations were available in a narrative review. We focused on study quality aspects most likely to impact the interpretation of results. We found that only one study, of medicinal talc use, evaluated direct exposure measurements for any individuals, though some used semi-quantitative exposure metrics, and few studies adequately assessed potential confounders. The only consistent associations were with ovarian cancer in case-control studies and these associations were likely impacted by recall and potentially other biases. This systematic review indicates that epidemiology studies do not support a causal association between occupational, medicinal, or personal talc exposure and any cancer in humans.

2.
J Ethn Subst Abuse ; 22(4): 681-687, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34704895

RESUMO

Background. We describe the prevalence of and changes in heroin use and injection drug use (IDU) among high school students in five large, urban school districts in the US (2005-2017); nearly three-fourths of the students were Black and/or Hispanic/Latino.Methods. Data are from the Centers for Disease Control and Prevention's "Youth Risk Behavior Survey" program, which includes biennial surveys in urban school districts. We pooled data across districts and survey years, and then generated weighted prevalence estimates (and 95% CIs) for any lifetime heroin use and IDU. Joinpoint regression modeling was used to estimate changes in prevalence over the study period.Results. Biennial prevalence estimates (2005-2017) for heroin use and IDU were above 1.8% for all seven timepoints. In 2017, prevalence of heroin use and IDU were 2.9% and 2.5%, respectively. Both heroin use and IDU were higher among boys than girls. There were statistically significant increases in heroin use and IDU among girls from 2005-2009, whereas changes over time were stable among boys.Conclusions. High school students in large, urban school districts may have higher rates of heroin use and IDU than US high school students in general, and there is little evidence of increases since 2009. This study suggests that adolescence may be a critical period for initiation of heroin use among adolescents in large urban school districts, the majority of whom are Black and/or Latino.Supplemental data for this article is available online at https://doi.org/10.1080/15332640.2021.1992327 .


Assuntos
Dependência de Heroína , Estudantes , Abuso de Substâncias por Via Intravenosa , Adolescente , Feminino , Humanos , Masculino , Heroína/efeitos adversos , Hispânico ou Latino/estatística & dados numéricos , Prevalência , Assunção de Riscos , Estudantes/estatística & dados numéricos , Inquéritos e Questionários , Estados Unidos/epidemiologia , População Urbana/estatística & dados numéricos , População Urbana/tendências , Dependência de Heroína/epidemiologia , Abuso de Substâncias por Via Intravenosa/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos , Comportamentos de Risco à Saúde
3.
Environ Res ; 212(Pt A): 113240, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35390303

RESUMO

The COVID-19 pandemic has resulted in an extraordinary incidence of morbidity and mortality, with almost 6 million deaths worldwide at the time of this writing (https://covid19.who.int/). There has been a pressing need for research that would shed light on factors - especially modifiable factors - that could reduce risks to human health. At least several hundred studies addressing the complex relationships among transmission of SARS-CoV-2, air pollution, and human health have been published. However, these investigations are limited by available and consistent data. The project goal was to seek input into opportunities to improve and fund exposure research on the confluence of air pollution and infectious agents such as SARS-CoV-2. Thirty-two scientists with expertise in exposure science, epidemiology, risk assessment, infectious diseases, and/or air pollution responded to the outreach for information. Most of the respondents expressed value in developing a set of common definitions regarding the extent and type of public health lockdown. Traffic and smoking ranked high as important sources of air pollution warranting source-specific research (in contrast with assessing overall ambient level exposures). Numerous important socioeconomic factors were also identified. Participants offered a wide array of inputs on what they considered to be essential studies to improve our understanding of exposures. These ranged from detailed mechanistic studies to improved air quality monitoring studies and prospective cohort studies. Overall, many respondents indicated that these issues require more research and better study design. As an exercise to solicit opinions, important concepts were brought forth that provide opportunities for scientific collaboration and for consideration for funding prioritization. Further conversations on these concepts are needed to advance our thinking on how to design research that moves us past the documented limitations in the current body of research and prepares us for the next pandemic.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Exposição Ambiental/análise , Humanos , Pandemias , Material Particulado , Estudos Prospectivos , SARS-CoV-2
4.
J Clin Microbiol ; 59(2)2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33139419

RESUMO

Accurate serological assays to detect antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to characterize the epidemiology of SARS-CoV-2 infection and identify potential candidates for coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) donation. This study compared the performances of commercial enzyme immunoassays (EIAs) with respect to detection of IgG or total antibodies to SARS-CoV-2 and neutralizing antibodies (nAbs). The diagnostic accuracy of five commercially available EIAs (Abbott, Euroimmun, EDI, ImmunoDiagnostics, and Roche) for detection of IgG or total antibodies to SARS-CoV-2 was evaluated using cross-sectional samples from potential CCP donors who had prior molecular confirmation of SARS-CoV-2 infection (n = 214) and samples from prepandemic emergency department patients without SARS-CoV-2 infection (n = 1,099). Of the 214 potential CCP donors, all were sampled >14 days since symptom onset and only a minority (n = 16 [7.5%]) had been hospitalized due to COVID-19; 140 potential CCP donors were tested by all five EIAs and a microneutralization assay. Performed according to the protocols of the manufacturers to detect IgG or total antibodies to SARS-CoV-2, the sensitivity of each EIA ranged from 76.4% to 93.9%, and the specificity of each EIA ranged from 87.0% to 99.6%. Using a nAb titer cutoff value of ≥160 as the reference representing a positive test result (n = 140 CCP donors), the empirical area under the receiver operating curve for each EIA ranged from 0.66 (Roche) to 0.90 (Euroimmun). Commercial EIAs with high diagnostic accuracy to detect SARS-CoV-2 antibodies did not necessarily have high diagnostic accuracy to detect high nAb titers. Some but not all commercial EIAs may be useful in the identification of individuals with high nAb titers among convalescent individuals.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/isolamento & purificação , COVID-19/sangue , Estudos Transversais , Humanos , Soros Imunes/imunologia , Técnicas Imunoenzimáticas , Imunoglobulina G/sangue , Testes de Neutralização , SARS-CoV-2/imunologia , Sensibilidade e Especificidade
5.
Ann Intern Med ; 173(4): 262-267, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32422057

RESUMO

BACKGROUND: Tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on reverse transcriptase polymerase chain reaction (RT-PCR) are being used to rule out infection among high-risk persons, such as exposed inpatients and health care workers. It is critical to understand how the predictive value of the test varies with time from exposure and symptom onset to avoid being falsely reassured by negative test results. OBJECTIVE: To estimate the false-negative rate by day since infection. DESIGN: Literature review and pooled analysis. SETTING: 7 previously published studies providing data on RT-PCR performance by time since symptom onset or SARS-CoV-2 exposure using samples from the upper respiratory tract (n = 1330). PATIENTS: A mix of inpatients and outpatients with SARS-CoV-2 infection. MEASUREMENTS: A Bayesian hierarchical model was fitted to estimate the false-negative rate by day since exposure and symptom onset. RESULTS: Over the 4 days of infection before the typical time of symptom onset (day 5), the probability of a false-negative result in an infected person decreases from 100% (95% CI, 100% to 100%) on day 1 to 67% (CI, 27% to 94%) on day 4. On the day of symptom onset, the median false-negative rate was 38% (CI, 18% to 65%). This decreased to 20% (CI, 12% to 30%) on day 8 (3 days after symptom onset) then began to increase again, from 21% (CI, 13% to 31%) on day 9 to 66% (CI, 54% to 77%) on day 21. LIMITATION: Imprecise estimates due to heterogeneity in the design of studies on which results were based. CONCLUSION: Care must be taken in interpreting RT-PCR tests for SARS-CoV-2 infection-particularly early in the course of infection-when using these results as a basis for removing precautions intended to prevent onward transmission. If clinical suspicion is high, infection should not be ruled out on the basis of RT-PCR alone, and the clinical and epidemiologic situation should be carefully considered. PRIMARY FUNDING SOURCE: National Institute of Allergy and Infectious Diseases, Johns Hopkins Health System, and U.S. Centers for Disease Control and Prevention.


Assuntos
Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Teorema de Bayes , Betacoronavirus , COVID-19 , Reações Falso-Negativas , Humanos , Pandemias , Reprodutibilidade dos Testes , Fatores de Risco , SARS-CoV-2
6.
J Hepatol ; 73(2): 294-302, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32240715

RESUMO

BACKGROUND & AIMS: Accurate HCV incidence estimates are critical for monitoring progress towards HCV elimination goals, including an 80% reduction in HCV incidence by 2030. Moreover, incidence estimates can help guide prevention and treatment programming, particularly in the context of the US opioid epidemic. METHODS: An inexpensive, Genedia-based HCV IgG antibody avidity assay was evaluated as a platform to estimate cross-sectional, population-level primary HCV incidence using 1,840 HCV antibody and RNA-positive samples from 875 individuals enrolled in 5 cohort studies in the US and India. Using samples collected <2 years following HCV seroconversion, the mean duration of recent infection (MDRI) was calculated by fitting a maximum likelihood binomial regression model to the probability of appearing recent. Among samples collected ≥2 years post-HCV seroconversion, an individual-level false recent ratio (FRR) was calculated by estimating the probability of appearing recent using an exact binomial test. Factors associated with falsely appearing recent among samples collected ≥2 years post seroconversion were determined by Poisson regression with generalized estimating equations and robust variance estimators. RESULTS: An avidity index cut-off of <40% resulted in an MDRI of 113 days (95% CI 84-146), and FRRs of 0.4% (95% CI 0.0-1.2), 4.6% (95% CI 2.2-8.3), and 9.5% (95% CI 3.6-19.6) among individuals who were HIV-uninfected, HIV-infected, and HIV-infected with a CD4 count <200/µl, respectively. No variation was seen between HCV genotypes 1 and 3. In hypothetical scenarios of high-risk settings, a sample size of <1,000 individuals could reliably estimate primary HCV incidence. CONCLUSIONS: This cross-sectional approach can estimate primary HCV incidence for the most common genotypes. This tool can serve as a valuable resource for program and policy planners seeking to monitor and reduce HCV burden. LAY SUMMARY: Determining the rate of new hepatitis C virus (HCV) infections in a population is critical to monitoring progress toward HCV elimination and to appropriately guide control efforts. However, since HCV infections are most often initially asymptomatic, it is difficult to estimate the rate of new HCV infections without following HCV-uninfected people over time and repeatedly testing them for HCV infection. Here, we present a novel, resource-efficient method to estimate the rate of new HCV infections in a population using data from a single timepoint.


Assuntos
Infecções por HIV , Hepacivirus , Anticorpos Anti-Hepatite C/isolamento & purificação , Hepatite C , Imunoglobulina G/isolamento & purificação , Afinidade de Anticorpos , Contagem de Linfócito CD4/métodos , Contagem de Linfócito CD4/estatística & dados numéricos , Estudos de Coortes , Monitoramento Epidemiológico , Infecções por HIV/sangue , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Hepatite C/imunologia , Humanos , Incidência , Índia , Soroconversão , Testes Sorológicos/métodos , Testes Sorológicos/estatística & dados numéricos , Estados Unidos/epidemiologia , Carga Viral/métodos , Carga Viral/estatística & dados numéricos
7.
J Child Adolesc Subst Abuse ; 29(4-6): 246-251, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-36540327

RESUMO

Introduction: The majority of epidemiologic research on adolescent non-medical anabolic-androgenic steroid (AAS) use was conducted in the 1990s and early 2000s, indicating a need to update evidence for the modern era. We aim to understand the prevalence of AAS use among US adolescents and assess associations between AAS use, sports participation, other drug use, and injection drug use (IDU). Methods: Using data from the 2017 National Youth Risk Behavior Survey, we estimated the prevalence of AAS use and tested for associations between AAS use, sports participation, and drug use, overall and by sex. Results: The prevalence of AAS use was 2.98%. The prevalence among boys (3.46%) was higher than among girls (2.41%). AAS use was high among youth with lifetime heroin use (64.41%) and IDU (64.42%). There was no association between AAS and team sport participation (p=0.61). Conclusions: Our results indicate that adolescent AAS use is an aspect of polysubstance use rather than a substance used solely for performance enhancement in sports. Research with adolescents should be mindful of the overlap of heroin and AAS use among youth with IDU.

8.
Clin Infect Dis ; 69(4): 709-712, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30605508

RESUMO

Among adults in the 2011-2016 National Health and Nutrition Examination Survey (NHANES), the estimated prevalence of hepatitis B surface antigen (HBsAg) was 0.36% overall and 3.4% in non-Hispanic Asians. Among adult HBsAg carriers, 42% had antibodies to hepatitis delta virus (anti-HDV). Routine anti-HDV testing should be considered for HBsAg carriers.


Assuntos
Hepatite B/epidemiologia , Hepatite D/epidemiologia , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Estados Unidos/epidemiologia , Adulto Jovem
9.
Clin Infect Dis ; 68(8): 1402-1405, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30239645

RESUMO

In the US household population, hepatitis C virus testing coverage marginally increased between 2013 and 2017 among persons born between 1966 and 1994 (13.2% to 16.8%) and persons born between 1945 and 1965 (12.3% to 17.3%). Testing coverage remains limited and sociodemographic disparities were observed in both populations.


Assuntos
Hepatite C/diagnóstico , Hepatite C/epidemiologia , Programas de Rastreamento/estatística & dados numéricos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia
10.
J Infect Dis ; 217(5): 785-789, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29186448

RESUMO

A cross-sectional study was conducted of 500 human immunodeficiency virus (HIV)-infected adults frequency matched on age, sex, and community to 500 HIV-uninfected individuals in the Rakai District, Uganda to evaluate seroprevalence of anti-hepatitis E virus (HEV) IgG antibodies. HEV seroprevalence was 47%, and 1 HIV-infected individual was actively infected with a genotype 3 virus. Using modified Poisson regression, male sex (prevalence ratios [PR] = 1.247; 95% confidence interval [CI], 1.071-1.450) and chronic hepatitis B virus infection (PR = 1.377; 95% CI, 1.090-1.738) were associated with HEV seroprevalence. HIV infection status (PR = 0.973; 95% CI, 0.852-1.111) was not associated with HEV seroprevalence. These data suggest there is a large burden of prior exposure to HEV in rural Uganda.


Assuntos
Anticorpos Anti-Hepatite/sangue , Vírus da Hepatite E/imunologia , Hepatite E/epidemiologia , Imunoglobulina G/sangue , Adulto , Estudos Transversais , Feminino , Infecções por HIV/complicações , Hepatite B Crônica/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estudos Soroepidemiológicos , Fatores Sexuais , Uganda/epidemiologia
11.
J Infect Dis ; 214(3): 344-52, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26768250

RESUMO

BACKGROUND: Sensitive methods are needed to estimate the population-level incidence of hepatitis C virus (HCV) infection. METHODS: We developed an HCV immunoglobulin G (IgG) antibody avidity assay by modifying the Ortho 3.0 HCV enzyme-linked immunoassay and tested 997 serum or plasma samples from 568 people who inject drugs enrolled in prospective cohort studies. Avidity-based testing algorithms were evaluated by their (1) mean duration of recent infection (MDRI), defined as the average time an individual is identified as having been recently infected, according to a given algorithm; (2) false-recent rate, defined as the proportion of samples collected >2 years after HCV seroconversion that were misclassified as recent; (3) sample sizes needed to estimate incidence; and (4) power to detect a reduction in incidence between serial cross-sectional surveys. RESULTS: A multiassay algorithm (defined as an avidity index of <30%, followed by HCV viremia detection) had an MDRI of 147 days (95% confidence interval [CI], 125-195 days), and the false-recent rates were 0.7% (95% CI, .2%-1.8%) and 7.6% (95% CI, 4.2%-12.3%) among human immunodeficiency virus (HIV)-negative and HIV-positive persons, respectively. In various simulated high-risk populations, this algorithm required <1000 individuals to estimate incidence (relative standard error, 30%) and had >80% power to detect a 50% reduction in incidence. CONCLUSIONS: Avidity-based algorithms have the capacity to accurately estimate HCV infection incidence and rapidly assess the impact of public health efforts among high-risk populations. Efforts to optimize this method should be prioritized.


Assuntos
Afinidade de Anticorpos , Biomarcadores/sangue , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/imunologia , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Imunoglobulina G/imunologia , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Hepatite C/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
14.
Proc Natl Acad Sci U S A ; 108(1): 325-30, 2011 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-21173246

RESUMO

Noroviruses are global agents of acute gastroenteritis, but the development of control strategies has been hampered by the absence of a robust animal model. Studies in chimpanzees have played a key role in the characterization of several fastidious hepatitis viruses, and we investigated the feasibility of such studies for the noroviruses. Seronegative chimpanzees inoculated i.v. with the human norovirus strain Norwalk virus (NV) did not show clinical signs of gastroenteritis, but the onset and duration of virus shedding in stool and serum antibody responses were similar to that observed in humans. NV RNA was detected in intestinal and liver biopsies concurrent with the detection of viral shedding in stool, and NV antigen expression was observed in cells of the small intestinal lamina propria. Two infected chimpanzees rechallenged 4, 10, or 24 mo later with NV were resistant to reinfection, and the presence of NV-specific serum antibodies correlated with protection. We evaluated the immunogenicity and efficacy of virus-like particles (VLPs) derived from NV (genogroup I, GI) and MD145 (genogroup II, GII) noroviruses as vaccines. Chimpanzees vaccinated intramuscularly with GI VLPs were protected from NV infection when challenged 2 and 18 mo after vaccination, whereas chimpanzees that received GII VLPs vaccine or a placebo were not. This study establishes the chimpanzee as a viable animal model for the study of norovirus replication and immunity, and shows that NV VLP vaccines could induce protective homologous immunity even after extended periods of time.


Assuntos
Modelos Animais de Doenças , Gastroenterite/prevenção & controle , Vírus Norwalk/genética , Pan troglodytes , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Sequência de Bases , Imunofluorescência , Gastroenterite/imunologia , Gastroenterite/virologia , Humanos , Imuno-Histoquímica , Injeções Intramusculares , Intestino Delgado/virologia , Dados de Sequência Molecular , Mucosa/virologia , Análise de Sequência de DNA , Fatores de Tempo , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas Virais/administração & dosagem
15.
Environ Pollut ; 347: 123442, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38278409

RESUMO

Exposure to ambient particulate matter (PM) has been associated with respiratory and cardiovascular outcomes, and nickel has been more frequently associated with these outcomes than other metal constituents of ambient PM. Because of this, we evaluated whether the evidence to date supports causal relationships between exposure to nickel in ambient PM and respiratory or cardiovascular outcomes. We critically reviewed 38 studies in human populations published between 2012 and 2022. Although a large variety of respiratory and cardiovascular outcomes were examined, data were sparse for many. As a result, we focused our evaluation on seven respiratory outcomes and three cardiovascular outcomes that were each examined in ≥3 studies. Of these health outcomes, exposure to nickel in ambient PM has been statistically significantly associated with respiratory mortality, respiratory emergency hospital visits, asthma, lung function (i.e., forced expiratory volume in 1 s, forced vital capacity), cardiovascular mortality, and ischemic heart disease mortality. Studies of the health outcomes of focus are subject to multiple methodological limitations, primarily ecological fallacy (short-term exposure studies), exposure measurement error, confounding, model misspecification, and multiple comparisons issue. While some statistically significant associations were reported, they were not strong, precise, or consistent. Statistically significant findings for long-term exposure to nickel in PM were largely reported in studies that could not establish temporality, despite their cohort study design. Statistically significant findings for short-term exposure to nickel in PM were largely reported in studies that could establish temporality, although this cannot inform causal inference at the individual level due to the aggregate level data used. The biological plausibility of the associations is only supported at high concentrations not relevant to ambient exposures. Overall, the literature to date does not provide adequate support for a causal relationship between nickel in ambient PM and respiratory or cardiovascular outcomes.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Doenças Cardiovasculares , Humanos , Material Particulado/toxicidade , Material Particulado/análise , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Níquel/toxicidade , Estudos de Coortes , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Pulmão/química , Poluição do Ar/análise , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia
16.
Proc Natl Acad Sci U S A ; 107(19): 8766-71, 2010 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-20421498

RESUMO

Hepatitis B virus (HBV)-associated acute liver failure (ALF) is a dramatic clinical syndrome due to a sudden loss of hepatic cells leading to multiorgan failure. The mechanisms whereby HBV induces ALF are unknown. Here, we show that liver tissue collected at the time of liver transplantation in two patients with HBV-associated ALF is characterized by an overwhelming B cell response apparently centered in the liver with massive accumulation of plasma cells secreting IgG and IgM, accompanied by complement deposition. We demonstrate that the molecular target of these antibodies is the hepatitis B core antigen (HBcAg); that these anti-bodies display a restricted variable heavy chain (V(H)) repertoire and lack somatic mutations; and that these two unrelated individuals with ALF use an identical predominant V(H) gene with unmutated variable domain (IGHV1-3) for both IgG and IgM anti-HBc antibodies, indicating that HBcAg is the target of a germline human V(H) gene. These data suggest that humoral immunity may exert a primary role in the pathogenesis of HBV-associated ALF.


Assuntos
Linfócitos B/imunologia , Perfilação da Expressão Gênica , Anticorpos Anti-Hepatite B/biossíntese , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Falência Hepática Aguda/genética , Fígado/imunologia , Linfócitos B/virologia , Linhagem da Célula , Análise por Conglomerados , Proteínas do Sistema Complemento/imunologia , Progressão da Doença , Hepatite B/sangue , Hepatite B/imunologia , Hepatite B/virologia , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Imuno-Histoquímica , Fígado/patologia , Fígado/virologia , Falência Hepática Aguda/sangue , Falência Hepática Aguda/imunologia , Falência Hepática Aguda/virologia , Necrose/imunologia , Necrose/patologia , Necrose/virologia , Linfócitos T/imunologia , Linfócitos T/virologia , Adulto Jovem
17.
Glob Epidemiol ; 6: 100117, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37637718

RESUMO

Aspartame is a dipeptide non-sugar sweetener that was first marketed in the US in carbonated beverages in 1983, before gaining prominence globally. The Joint Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) and the WHO International Agency for Research on Cancer (IARC) completed evaluations of aspartame and cancer in July 2023. JECFA reaffirmed the safety of aspartame, stating that epidemiology evidence is "not convincing," and that there are no consistent associations between aspartame and cancer (JECFA/IARC, 2023; JECFA, 2023). JECFA also noted "reverse causality, chance, bias and confounding by socioeconomic or lifestyle factors, or consumption of other dietary components, could not be completely ruled out" in relevant epidemiology studies (JECFA/IARC, 2023). In contrast, IARC stated that there are three "high quality" studies on liver cancer (Riboli, 2023), but that the evidence is limited because "chance, bias or confounding could not be ruled out as an explanation for the positive findings" (JECFA/IARC, 2023). IARC does not provide an explanation as to how these studies can be both high quality and have these weaknesses, most notably potential exposure misclassification, or how inconsistent associations from studies with these weaknesses constitute limited evidence. Further, when IARC concludes an agent has limited or inadequate human evidence (and no sufficient animal or strong mechanistic evidence), it classifies that agent as either Group 2B, a possible human carcinogen, or Group 3, not classifiable as to its carcinogenicity. Ultimately, the interpretations of Group 2B and Group 3 classifications are intended to be similar. However, a Group 2B designation may make it appear to scientists and non-scientists alike that the evidence is pointing in the direction of causality. This can lead to unnecessary confusion with respect to the evidence, as well as a perception of a disagreement within WHO regarding aspartame. This apparent contradiction could have been avoided by assigning the IARC classification most consistent with the conclusion that the human evidence for cancer is inadequate: Group 3.

18.
Glob Epidemiol ; 5: 100110, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37638370

RESUMO

Toews et al. [1] and the World Health Organization (WHO) [2] reviewed observational epidemiology studies of non-sugar sweeteners (NSSs) and various health effects. The former used the Risk of Bias in Non-randomised Studies - of Interventions (ROBINS-I) tool and the latter used both the ROBINS-I tool and the Newcastle-Ottawa Scale to evaluate study quality. Both reviews concluded that there were no associations between NSS or aspartame consumption and cancer (except possibly between saccharin and bladder cancer) but indicated that the certainty of the evidence for all cancer types was "very low." While we agree with this conclusion, the support for the confidence in the evidence generally was not transparently documented, as the results of the study quality assessment were only provided in scores or ratings. An examination of illustrative case studies shows that some important aspects of study quality domains specific for NSSs generally or aspartame specifically (i.e., issues with the exposure and outcome assessments, the consideration of confounding/covariates, and selection bias) may have been overlooked or not given appropriate consideration, while other aspects that were less likely to have a large impact on overall study quality dominated the results in the two assessments. Our review of other studies published after the WHO [2] review further demonstrates this point. While this may not seem important given the overall lack of associations, it impacts the degree to which evidence supports a lack of effects as opposed to not being adequate to evaluate associations. In the future, aspartame and cancer outcome reviews should focus on those study quality domains that are most likely to impact the interpretation of results and discuss them in a transparent, systematic manner. If there is very low certainty in the evidence as a result of low study quality, reviewers should conclude the evidence is inadequate for making a causal determination.

19.
J Virol ; 85(17): 8656-66, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21715504

RESUMO

Noroviruses are the most common cause of epidemic gastroenteritis. Genotype II.3 is one of the most frequently detected noroviruses associated with sporadic infections. We studied the evolution of the major capsid gene from seven archival GII.3 noroviruses collected during a cross-sectional study at the Children's Hospital in Washington, DC, from 1975 through 1991, together with capsid sequence from 56 strains available in GenBank. Evolutionary analysis concluded that GII.3 viruses evolved at a rate of 4.16 × 10(-3) nucleotide substitutions/site/year (strict clock), which is similar to that described for the more prevalent GII.4 noroviruses. The analysis of the amino acid changes over the 31-year period found that GII.3 viruses evolve at a relatively steady state, maintaining 4% distance, and have a tendency to revert back to previously used residues while preserving the same carbohydrate binding profile. In contrast, GII.4 viruses demonstrate increasing rates of distance over time because of the continued integration of new amino acids and changing HBGA binding patterns. In GII.3 strains, seven sites acting under positive selection were predicted to be surface-exposed residues in the P2 domain, in contrast to GII.4 positively selected sites located primarily in the shell domain. Our study suggests that GII.3 noroviruses caused disease as early as 1975 and that they evolve via a specific pattern, responding to selective pressures induced by the host rather than presenting a nucleotide evolution rate lower than that of GII.4 noroviruses, as previously proposed. Understanding the evolutionary dynamics of prevalent noroviruses is relevant to the development of effective prevention and control strategies.


Assuntos
Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/genética , Evolução Molecular , Gastroenterite/virologia , Norovirus/classificação , Norovirus/genética , Substituição de Aminoácidos/genética , Criança , Pré-Escolar , District of Columbia , Humanos , Lactente , Dados de Sequência Molecular , Norovirus/isolamento & purificação , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
20.
Glob Epidemiol ; 4: 100084, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37637021

RESUMO

Environmental epidemiology has proven critical to study various associations between environmental exposures and adverse human health effects. However, there is a perception that it often does not sufficiently inform quantitative risk assessment. To help address this concern, in 2017, the Health and Environmental Sciences Institute initiated a project engaging the epidemiology, exposure science, and risk assessment communities with tripartite representation from government agencies, industry, and academia, in a dialogue on the use of environmental epidemiology for quantitative risk assessment and public health decision making. As part of this project, four meetings attended by experts in epidemiology, exposure science, toxicology, statistics, and risk assessment, as well as one additional meeting engaging funding agencies, were organized to explore incentives and barriers to realizing the full potential of epidemiological data in quantitative risk assessment. A set of questions was shared with workshop participants prior to the meetings, and two case studies were used to support the discussion. Five key ideas emerged from these meetings as areas of desired improvement to ensure that human data can more consistently become an integral part of quantitative risk assessment: 1) reducing confirmation and publication bias, 2) increasing communication with funding agencies to raise awareness of research needs, 3) developing alternative funding channels targeted to support quantitative risk assessment, 4) making data available for reuse and analysis, and 5) developing cross-disciplinary and cross-sectoral interactions, collaborations, and training. We explored and integrated these themes into a roadmap illustrating the need for a multi-stakeholder effort to ensure that epidemiological data can fully contribute to the quantitative evaluation of human health risks, and to build confidence in a reliable decision-making process that leverages the totality of scientific evidence.

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