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1.
Nat Commun ; 15(1): 2716, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548759

RESUMO

Neural stem and progenitor cell (NSPC) maintenance is essential for ensuring that organisms are born with proper brain volumes and head sizes. Microcephaly is a disorder in which babies are born with significantly smaller head sizes and cortical volumes. Mutations in subunits of the DNA organizing complex condensin have been identified in microcephaly patients. However, the molecular mechanisms by which condensin insufficiency causes microcephaly remain elusive. We previously identified conserved roles for condensins in repression of retrotransposable elements (RTEs). Here, we show that condensin subunit knockdown in NSPCs of the Drosophila larval central brain increases RTE expression and mobility which causes cell death, and significantly decreases adult head sizes and brain volumes. These findings suggest that unrestricted RTE expression and activity may lead to improper brain development in condensin insufficient organisms, and lay the foundation for future exploration of causative roles for RTEs in other microcephaly models.


Assuntos
Adenosina Trifosfatases , Drosophila melanogaster , Microcefalia , Complexos Multiproteicos , Animais , Humanos , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Microcefalia/genética , Proteínas de Ligação a DNA/metabolismo , Drosophila/genética , Encéfalo/metabolismo
2.
Rev Soc Bras Med Trop ; 57: e007022024, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38359311

RESUMO

BACKGROUND: Syphilis is associated with social and behavioral factors. METHODS: This cross-sectional study determined the prevalence of syphilis and its associated risk factors among recyclable waste collectors in Central Brazil. RESULTS: A lifetime syphilis prevalence rate of 7.91% (95% confidence interval: 5.25-11.75) was found among 278 participants. Low educational level, history of sexually transmitted infection, and age ≥ 36 years were associated with a high prevalence of lifetime syphilis. CONCLUSIONS: These findings emphasize the need for syphilis prevention, screening, and treatment among recyclable waste collectors, highlighting the potential for the spread of infection in vulnerable populations.


Assuntos
Infecções por HIV , Sífilis , Humanos , Adulto , Sífilis/epidemiologia , Brasil/epidemiologia , Prevalência , Estudos Transversais , Fatores de Risco , Infecções por HIV/epidemiologia
3.
Rev. Soc. Bras. Med. Trop ; 57: e00702, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1535377

RESUMO

ABSTRACT Background: Syphilis is associated with social and behavioral factors. Methods: This cross-sectional study determined the prevalence of syphilis and its associated risk factors among recyclable waste collectors in Central Brazil. Results: A lifetime syphilis prevalence rate of 7.91% (95% confidence interval: 5.25-11.75) was found among 278 participants. Low educational level, history of sexually transmitted infection, and age ≥ 36 years were associated with a high prevalence of lifetime syphilis. Conclusions: These findings emphasize the need for syphilis prevention, screening, and treatment among recyclable waste collectors, highlighting the potential for the spread of infection in vulnerable populations.

4.
J Clin Microbiol ; 61(11): e0077123, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37933990

RESUMO

Hepatitis C virus (HCV) infection is an underdiagnosed global health problem. Diagnosis of current HCV infections typically requires testing for HCV RNA using high-complexity laboratory tests. Methods for the detection of HCV RNA that are simple, inexpensive, rapid, and compatible with use outside of a laboratory setting are very important in order to improve access to hepatitis C diagnostic testing and facilitate accelerated linkage to care. We developed and evaluated three simple workflows for extracting HCV RNA from small volumes of whole blood for use in a sensitive, pan-genotypic RT-LAMP assay. The water workflow uses osmotic stress to release HCV RNA and has a limit of detection of 4.3 log10(IU/mL) (95% CI 4.0-4.9). The heat workflow uses a heating step to release HCV RNA and has a limit of detection of 4.2 log10(IU/mL) (95% CI 3.8-5.1). The bead workflow, which uses chemical lysis of the sample and a streamlined paramagnetic solid phase reversible immobilization bead procedure for nucleic acid purification, has a limit of detection of 2.8 log10(IU/mL) (95% CI 2.5-3.4). When used to test whole blood spiked with HCV RNA-positive plasma samples in which most HCV levels were below 5.0 log10(IU/mL), the water, heat, and bead workflows detected HCV RNA in 69%, 75%, and 94% of samples, respectively. These workflows are compatible with visual lateral flow dipsticks, and each takes less than 60 min from sample to result. Each workflow can be performed with minimal and inexpensive equipment. With further procedural simplifications, these workflows may form the basis of assays for the point-of-care diagnosis of HCV infections.


Assuntos
Hepacivirus , Hepatite C , Humanos , Hepacivirus/genética , Transcrição Reversa , Sensibilidade e Especificidade , RNA Viral , Hepatite C/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Água
5.
PLoS One ; 18(4): e0283868, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37098017

RESUMO

Hepatitis A virus (HAV) infection is transmitted by the fecal-oral route, through interpersonal contact and ingestion of contaminated food or water. Prisoners are at higher risk of acquiring HAV infection mainly due to the environment of closed penal institutions and socioeconomic conditions. This study aims to determine the seroprevalence of anti-HAV and its associated risk factors among inmates from twelve prisons in Central Brazil. A cross-sectional study was conducted between March 2013 and March 2014. A total of 580 prisoners participated in the study. The participant's samples were tested for Total and IgM anti-HAV antibodies by electrochemiluminescence immunoassay (ECLIA). Risk factors associated with anti-HAV seropositivity were also analyzed. The prevalence rate of HAV exposure was 88.1% (95% CI: 85.5-90.7). No sample had a positive reaction to IgM anti-HAV. Increasing age, low level of education, and being imprisoned in Corumbá city were independently associated with HAV exposure among prisoners. To prevent the burden of the disease, vaccination strategies should be considered for susceptible prisoners in Central Brazil.


Assuntos
Vírus da Hepatite A , Hepatite A , Humanos , Anticorpos Anti-Hepatite A , Brasil/epidemiologia , Estudos Transversais , Estudos Soroepidemiológicos , Prevalência , Estabelecimentos Correcionais , Imunoglobulina M
6.
Trop Med Infect Dis ; 8(4)2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37104324

RESUMO

Sexually transmitted Human alphaherpesvirus 2 (HSV-2) causes genital ulcers, especially among sexually active adolescents and adults. We estimated the exact prevalence of anti-HSV-2 antibodies and correlated it with the demographic and behavioral aspects of the Indigenous population of the Jaguapirú and Bororó villages (Dourados, Mato Grosso do Sul (MS), Brazil). In total, 1360 individuals (>18 years old) were administered serologic tests. The prevalence of anti-HSV-2 IgM was 12.9%, that of anti-HSV-2 IgG was 57.2%, and 8.5% cases tested positive for both HSV-2 IgM and IgG. The prevalence of anti-HSV-2 antibodies was higher in females (59.5%) compared to males (49%), with an OR of 0.64 (0.49-0.83). Anti-HSV-2 antibodies were found in 14.2%, 12.3%, 15.4%, and 14.5% of participants with urinary problems, genital wounds, genital warts, and urethral discharge, respectively. In summary, the seroprevalence of HSV-2 in the Indigenous population was five times higher than that reported in the general adult Brazilian population. Educational level, income level, smoking, condom use, incarceration, illicit drug abuse, the sharing of used needles and syringes without adequate disinfection, homosexual relationships, prostitution, the sexual practices among drug users, and avoidance of contraceptive methods could contribute to the facilitation of HSV-2 transmission in the Indigenous population. Our results may help develop culturally appropriate intervention programs that eliminate health-access barriers and improve the implementation of public health policies aimed at promoting information regarding and preventing, treating, and controlling HSV-2 infection in Brazilian Indigenous populations.

7.
Sci Rep ; 12(1): 16701, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36202887

RESUMO

Human T-lymphotropic viruses 1 and 2 (HTLV-1/2) have a worldwide distribution. HTLV-1 has been associated with several diseases, including an aggressive malignant disease known as adult T-cell leukemia/lymphoma and a chronic inflammatory neurological disease called HTLV-1-associated myelopathy, while HTLV-2 has not been definitively associated with diseases. HTLV-2 is most prevalent in specific groups such as injecting drug users and the indigenous population. In Brazil, most studies about HTLV in indigenous are carried out in indigenous communities from the north of the country. Mato Grosso do Sul (MS), Central Brazil, has the second-largest indigenous population in Brazil. However, there is no available data about HTLV infection in this group. We conducted the first investigation of HTLV-1/2 infection prevalence in the indigenous population from Jaguapiru and Bororó villages in Dourados City, MS, to provide the prevalence and molecular characterization of HTLV. For that, a total of 1875 indigenous participated in the study. All the serum samples were screened by an enzyme-linked immunosorbent assay commercial kit for the presence of anti-HTLV-1/2 antibodies. Positive samples were confirmed by HTLV-1/2 Western Blot assay. The HTLV-1 5'LTR region was detected by nested PCR amplification and sequenced by Sanger. Most of the study population declared belonging to Guarani-Kaiowá ethnicity (69.18%), 872 (46.51%), and 1003 (53.49%) were from Jaguapiru and Bororó villages, respectively. The median age of participants was 31 years, and 74.24% were females. Two individuals were detected with HTLV-1 (0.1%; CI 95% 0.1-0.2). The phylogenetic analysis revealed that isolates belong to the Cosmopolitan subtype and the Transcontinental subgroup (HTLV-1aA). The low HTLV-1 prevalence found in this study is similar to that observed among blood donors, and pregnant populations from Mato Grosso do Sul. The absence of HTLV-2 infection among these Brazilian indigenous communities would suggest a distinct behavior pattern from other indigenous populations in Brazil.


Assuntos
Infecções por HTLV-I , Infecções por HTLV-II , Vírus Linfotrópico T Tipo 1 Humano , Adulto , Brasil/epidemiologia , Feminino , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-II/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 2 Humano/genética , Humanos , Masculino , Filogenia , Gravidez , Prevalência
8.
Nucleic Acids Res ; 50(18): 10680-10694, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36169232

RESUMO

Condensin I and condensin II are multi-subunit complexes that are known for their individual roles in genome organization and preventing genomic instability. However, interactions between condensin I and condensin II subunits and cooperative roles for condensin I and condensin II, outside of their genome organizing functions, have not been reported. We previously discovered that condensin II cooperates with Gamma Interferon Activated Inhibitor of Translation (GAIT) proteins to associate with Long INterspersed Element-1 (LINE-1 or L1) RNA and repress L1 protein expression and the retrotransposition of engineered L1 retrotransposition in cultured human cells. Here, we report that the L1 3'UTR is required for condensin II and GAIT association with L1 RNA, and deletion of the L1 RNA 3'UTR results in increased L1 protein expression and retrotransposition. Interestingly, like condensin II, we report that condensin I also binds GAIT proteins, associates with the L1 RNA 3'UTR, and represses L1 retrotransposition. We provide evidence that the condensin I protein, NCAPD2, is required for condensin II and GAIT protein association with L1 RNA. Furthermore, condensin I and condensin II subunits interact to form a L1-dependent super condensin complex (SCC) which is located primarily within the cytoplasm of both transformed and primary epithelial cells. These data suggest that increases in L1 expression in epithelial cells promote cytoplasmic condensin protein associations that facilitate a feedback loop in which condensins may cooperate to mediate L1 repression.


Assuntos
Elementos Nucleotídeos Longos e Dispersos , Complexos Multiproteicos/metabolismo , Regiões 3' não Traduzidas , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA , Humanos , Interferon gama/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética
9.
Viruses ; 14(8)2022 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-36016283

RESUMO

Higher rates of human immunodeficiency virus (HIV) infection have been detected in prisoners when compared with the general population, but research into HIV molecular epidemiology and its transmission network has been lacking among them. Thus, this study aimed to verify potential HIV molecular transmission networks among prisoners. In addition, we aimed to describe the mutations related to antiretroviral resistance in these isolates. Thus, we conducted a cross-sectional survey from 2013 to 2018 in prisons in Central-Western Brazil, and the final sampling composed of 84 prisoners. Proviral DNA was extracted from each whole blood sample followed by amplification of the partial polymerase gene and sequencing. Forty-nine sequences (58.3%) were classified as subtype B, followed by C (14.3%), D, and F1 (2.4% each). A complex and dynamic HIV-1 epidemic is observed in the prisons, as 25% of the sequences were recombinant forms. We detected 15 HIV transmission clusters composed of at least two sequences, that included not only prisoners but also individuals from the general population from the same State with a variety of risk behaviors. Thirty-two percent (32.0%) of treatment-experienced prisoners had at least one drug resistance mutation (DRM), while transmitted DRMs were found in 5.9% of the prisoners. We highlight the urgent need for routine surveillance of HIV-1 infection including resistance genotypic tests considering the high disease burden, risky behaviors inside prisons, and the dynamic relationship of prisoners with the outside community.


Assuntos
Infecções por HIV , HIV-1 , Prisioneiros , Brasil/epidemiologia , Estudos Transversais , HIV-1/genética , Humanos , Epidemiologia Molecular
10.
Viruses ; 14(5)2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35632826

RESUMO

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9-14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4-69.4%). In contrast, only 19.2% (CI 95%: 17.6-20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.


Assuntos
Emigrantes e Imigrantes , Hepatite B , Brasil/epidemiologia , Estudos Transversais , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Humanos , Japão/epidemiologia
11.
Braz J Infect Dis ; 26(2): 102350, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35487275

RESUMO

A cross-sectional study was carried out in the Hematology and Hemotherapy Institute of the state of Mato Grosso do Sul (Hemosul) to evaluate the seroprevalence and risk factors of Hepatitis E Virus (HEV) exposure among volunteer blood donors in Central Brazil. Two-hundred fifty samples from the biorepository were tested for anti-HEV IgG and IgM using the Wantai HEV ELISA test. The seroprevalence of HEV exposure was 6.4% (95% CI: 3.9-10.2). Being born in another state of Brazil, mainly in the Southeast and South regions, was associated with a higher risk of HEV exposure (p < 0.001).


Assuntos
Vírus da Hepatite E , Hepatite E , Doadores de Sangue , Brasil/epidemiologia , Estudos Transversais , Anticorpos Anti-Hepatite , Hepatite E/epidemiologia , Humanos , Imunoglobulina M , Estudos Soroepidemiológicos , Voluntários
12.
Braz. j. infect. dis ; 26(2): 102350, 2022. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1384116

RESUMO

Abstract A cross-sectional study was carried out in the Hematology and Hemotherapy Institute of the state of Mato Grosso do Sul (Hemosul) to evaluate the seroprevalence and risk factors of Hepatitis E Virus (HEV) exposure among volunteer blood donors in Central Brazil. Two-hundred fifty samples from the biorepository were tested for anti-HEV IgG and IgM using the Wantai HEV ELISA test. The seroprevalence of HEV exposure was 6.4% (95% CI: 3.9-10.2). Being born in another state of Brazil, mainly in the Southeast and South regions, was associated with a higher risk of HEV exposure (p < 0.001).

13.
PLoS Negl Trop Dis ; 15(2): e0009066, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33544713

RESUMO

Human T-cell leukemia virus type 1 (HTLV-1) has worldwide distribution and is considered endemic in southwestern Japan. HTLV-1 infection has been associated with adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) besides other diseases. This cross-sectional study aimed to investigate the prevalence, risk factors and molecular characterization of HTLV-1, among the world's largest population of Japanese immigrants and their descendants outside of Japan, in São Paulo, Southeast Brazil, as well as to analyze the phylogenetic relationship among isolates of HTLV-1. From July to December 2017, 2,139 individuals from five Japanese associations were interviewed and submitted to blood collection. All serum samples were first tested for the presence of anti-HTLV-1/2 antibodies by ELISA and then peripheral blood from individuals with positive serological results were analyzed for the presence of HTLV-1 5'LTR proviral DNA. Partial sequencing of the 5'LTR region of HTLV-1 proviral DNA was performed by Sanger. The prevalence of HTLV-1 infection was 5.1% (CI 95%: 4.2-6.0). In the multiple logistic regression model, HTLV-1 infection was associated with age ≥ 45 years, female sex, being first and second-generation Japanese immigrants, and having sexual partners with history of blood transfusion. The phylogenetic analysis revealed that all HTLV-1 were classified as Cosmopolitan (1a) subtype. Of them, 47.8% were classified as Transcontinental (A) subgroup and 52.2% as belonging to the Japanese (B) subgroup. Although most HTLV-1-infected patients were asymptomatic (97.3%), blurred vision was associated with HTLV-1 infection. The high prevalence of HTLV-1 infection found in this studied population and especially the intra- and interfamily HTLV-1 transmission presents an urgent call for preventive and control responses of this infection in Brazil.


Assuntos
Emigrantes e Imigrantes , Infecções por HTLV-I/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano , Leucemia de Células T/epidemiologia , Leucemia de Células T/prevenção & controle , Adulto , Doenças Assintomáticas , Brasil/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Vírus Linfotrópico T Tipo 1 Humano/classificação , Vírus Linfotrópico T Tipo 1 Humano/genética , Humanos , Japão , Leucemia de Células T/virologia , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Paraparesia Espástica Tropical/virologia , Linhagem , Filogenia , Prevalência , Provírus , Fatores de Risco
15.
Sci Rep ; 10(1): 6708, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317697

RESUMO

Hepatitis B virus (HBV) infection is still a concern in vulnerable populations. In a study performed by our team in 1999-2003 in two Afro-Brazilian communities, Furnas dos Dionísios (FD) and São Benedito (SB), high prevalence rates of HBV exposure (42.7% and 16.0%, respectively), high susceptibility to HBV (55.3% and 63.0%) and low HBV vaccination like profile rates (2.0% and 21.0%) were observed. In 2015-2016, we reassessed HBV epidemiological and molecular features in these two communities to verify the impact of health actions adopted in the last years. The prevalence rate of HBV exposure among the enrolled 331 subjects was 35.3% in FD and 21.8% in SB. HBV chronic infection (5.8% in FD, 4.9% in SB) remained high. The rate of HBV vaccination like profile increased from 10.7% to 43.5% (2.0% to 45.9% in FD, 21.0% to 39.5% in SB) while susceptible subjects declined from 58.9% to 26.3% (55.3% to 18.8% in FD, 63.0% to 38.7% in SB). Among 18 HBsAg positive samples, 13 were successfully sequenced (pre-S/S region). Phylogenetic analyses showed that all isolates belong to HBV subgenotype A1, clustering within the Asian-American clade. Despite the maintenance of high prevalence rate of HBV exposure over these 13 years of surveillance, significant improvements were observed, reinforcing the importance of facilitated HBV vaccination to difficult-to-access population to close gaps in prevention.


Assuntos
População Negra , Hepatite B/epidemiologia , Adolescente , Adulto , Asiático , Comportamento , Biomarcadores/sangue , Brasil/epidemiologia , Criança , Pré-Escolar , Demografia , Feminino , Hepatite B/sangue , Hepatite B/imunologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Filogenia , Prevalência , Vacinação , Adulto Jovem
16.
Int J Infect Dis ; 90: 46-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31589921

RESUMO

OBJECTIVES: To evaluate the epidemiological and molecular features of HBV infection among recyclable waste collectors. METHODS: The participants were recruited from the dumping ground and recycling cooperatives in Campo Grande, Brazil, and were screened for hepatitis B and C, and HIV serological markers by ELISA, confirmed by PCR. RESULTS: Among 278 participants, 63.7% (95% CI: 58.0-69.3) were considered susceptible to HBV infection. The prevalence rate of HBV exposure was 10.1% (95% CI: 6.5-13.6) and 0.4% (95% CI: 0.1-0.6) were chronic carriers. Age ≥45 years (AOR=7.15), history of homosexual contact (AOR=5.29), tattoo (AOR=4.92) and history of surgery (AOR=2.89) were factors associated with ever infection. Age 18-25 years (AOR=4.63), educational level ≥9 years (AOR=1.98) and knowledge about HBV transmission (AOR=3.08) were associated with serological HBV vaccination like profile (26.2%; 95% CI: 21.1-31.4). CONCLUSIONS: Despite the availability and efficacy of HBV vaccine, this study found high HBV exposure and proportion of susceptible adults in a low endemic area. Vaccination and screening campaigns using accessible language to the economically disadvantaged populations can reduce the number of people susceptible to HBV infection.


Assuntos
Antígenos de Superfície da Hepatite B/administração & dosagem , Vacinas contra Hepatite B/administração & dosagem , Vírus da Hepatite B/imunologia , Hepatite B/prevenção & controle , Adolescente , Adulto , Brasil/epidemiologia , Estudos Transversais , Doenças Endêmicas/prevenção & controle , Doenças Endêmicas/estatística & dados numéricos , Feminino , Hepatite B/epidemiologia , Hepatite B/virologia , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Vacinação/estatística & dados numéricos , Cobertura Vacinal/estatística & dados numéricos , Populações Vulneráveis/estatística & dados numéricos , Adulto Jovem
17.
ACS Macro Lett ; 9(6): 781-787, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35648526

RESUMO

Here we report microphase-separated poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) as a reinforcing filler in PDMS thermosets that overcomes the long-standing problem of aging in the processing of silica-reinforced silicone. Surprisingly, PS-b-PDMS reinforced composites display comparable mechanical performance to silica-modified analogs, even though the modulus of PS is much smaller than that of silica and there is no evidence of percolation with respect to the rigid PS domains. We have found that a few unique characteristics contribute to the reinforcing performance of PS-b-PDMS. The strong self-assembly behavior promotes batch-to-batch repeatability by having well-dispersed fillers. The structure and size of the fillers depend on the loading and characteristics of both filler and matrix, along with the shear effect. The reinforcing effect of PS-b-PDMS is mostly brought by the entanglements between the corona layer of the filler and the matrix, rather than the hydrodynamic reinforcement of the PS phase.

18.
PLoS One ; 14(8): e0221265, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31437184

RESUMO

Viral hepatitis, syphilis, HIV, and tuberculosis infections in prisons have been identified globally as a public health problem. Tuberculosis (TB) and viral hepatitis co-infection may increase the risk of anti-tuberculosis treatment-induced hepatotoxicity, leading to the frequent cause of discontinuation of the first-line anti-tuberculosis drugs. Therefore, the aim of this cross-sectional study was to investigate the epidemiological features of HCV, HBV, syphilis and HIV infections among bacteriologically confirmed tuberculosis prisoners in Campo Grande (MS), Central Brazil. The participants who agreed to participate (n = 279) were interviewed and tested for the presence of active or current HCV, HBV, syphilis and HIV infections. The prevalence of HCV exposure was 4.7% (13/279; 95% CI 2.2-7.1). HCV RNA was detected in 84.6% (11/13) of anti-HCV positive samples. Out of 279 participants, 19 (6.8%; 95% CI 4.4-10.4) were HIV co-infected, 1.4% (4/279, 95% CI 0.5-3.8) had chronic hepatitis B virus (HBsAg positive) and 9.3% (26/279, 95% CI 6.4-13.4) had serological marker of exposure to hepatitis B virus (total anti-HBc positive). The prevalence of lifetime syphilis infection (anti-T. pallidum positive) was 10% (28/279, 95% CI 7.0-14.2) and active syphilis (VDRL ≥ 1/8 titre) was 5% (14/279, 95% CI 2.9-8.3). The prevalence of TB/HCV co-infection among prisoners with HIV (15.8%) was higher than among HIV-non-infected prisoners (3.8%; P<0.05). These results highlight the importance of hepatitis testing among prisoners with bacteriologically confirmed case of TB who can be more effectively and safely treated in order to reduce the side effects of hepatotoxic anti-TB drugs.


Assuntos
Infecções por HIV/epidemiologia , Hepatite B Crônica/epidemiologia , Hepatite C Crônica/epidemiologia , Prisioneiros , Sífilis/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adulto , Brasil/epidemiologia , Coinfecção , Estudos Transversais , HIV/isolamento & purificação , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , Hepacivirus/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/virologia , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/virologia , Humanos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Saúde Pública/ética , Sífilis/diagnóstico , Sífilis/microbiologia , Treponema pallidum/isolamento & purificação , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia
19.
Braz J Infect Dis ; 22(6): 472-476, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30528600

RESUMO

Human T cell lymphotropic virus type 1 (HTLV-1) was the first retrovirus discovered in humans and is endemic in several parts of the world. Because of risk behaviors, mainly sexual, men who have sex with men (MSM) are at high risk of acquiring HTLV-1 infection. A cross-sectional study was performed to estimate the prevalence of HTLV-1 infection, to characterize genetically HTLV-1 sequences and to identify risk behaviors associated with this infection among MSM in Central Brazil. A total of 430 MSM were enrolled in this study and three were shown to be HTLV-1 infected, prevalence of 0.7% (95% confidence interval: 0.4-0.9). Phylogenetic analysis showed that all HTLV-1 positive samples belonged to Cosmopolitan subtype Transcontinental subgroup A. Although the prevalence rate of HTLV-1 infection found in this study was similar to that observed among Brazilian blood donors, additional HTLV-1 preventive interventions need to be further implemented because this population is engaged in high-risk sexual behavior.


Assuntos
Infecções por HTLV-I/epidemiologia , Homossexualidade Masculina/estatística & dados numéricos , Vírus Linfotrópico T Tipo 1 Humano/genética , Adulto , Idoso , Brasil/epidemiologia , Estudos Transversais , Infecções por HTLV-I/diagnóstico , Infecções por HTLV-I/transmissão , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Prevalência , Fatores de Risco , Minorias Sexuais e de Gênero , Adulto Jovem
20.
Braz. j. infect. dis ; 22(6): 472-476, Nov.-Dec. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-984015

RESUMO

ABSTRACT Human T cell lymphotropic virus type 1 (HTLV-1) was the first retrovirus discovered in humans and is endemic in several parts of the world. Because of risk behaviors, mainly sexual, men who have sex with men (MSM) are at high risk of acquiring HTLV-1 infection. A cross-sectional study was performed to estimate the prevalence of HTLV-1 infection, to characterize genetically HTLV-1 sequences and to identify risk behaviors associated with this infection among MSM in Central Brazil. A total of 430 MSM were enrolled in this study and three were shown to be HTLV-1 infected, prevalence of 0.7% (95% confidence interval: 0.4-0.9). Phylogenetic analysis showed that all HTLV-1 positive samples belonged to Cosmopolitan subtype Transcontinental subgroup A. Although the prevalence rate of HTLV-1 infection found in this study was similar to that observed among Brazilian blood donors, additional HTLV-1 preventive interventions need to be further implemented because this population is engaged in high-risk sexual behavior.


Assuntos
Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Vírus Linfotrópico T Tipo 1 Humano/genética , Infecções por HTLV-I/epidemiologia , Homossexualidade Masculina/estatística & dados numéricos , Filogenia , Brasil/epidemiologia , Infecções por HTLV-I/diagnóstico , Infecções por HTLV-I/transmissão , Prevalência , Estudos Transversais , Fatores de Risco , Minorias Sexuais e de Gênero
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