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1.
Infect Agent Cancer ; 13: 41, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30607173

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant cancer of the liver and a leading cause of cancer-related mortality worldwide. Human immunodeficiency virus (HIV) has not been known to have a direct causal relationship with HCC despite independently causing inflammation of the liver. However, little is known on risk factors for HCC patients in an HIV endemic area. The objective of this study was to ascertain the risk factors of HCC and its association with HIV infection. METHODS: This was an un-matched case-control study conducted between June 2015 and June 2016 in Kisumu County Referral Hospital, Kenya. The study enrolled 257 patients with HCC cases and 257 controls. A multivariable logistic regression analysis was used to assess the risk factors for HIV and controlling for exploratory variables. Independent t-test was used to compare means. Exposure variable with values < 0.05 were considered to be statistically significant. RESULTS: HCC cases were more likely to be above 35 years old compared to controls (88.3% vs 23.0%), [aOR =51.6, 95% CI (27.8-95.6), P < 0.001)]. HBV infected patients have higher risk of HCC (47.1% vs 30.4%), [aOR = 3.3; 95% CI (1.7-5.0), P < 0.0001)]. HIV positive patients were more likely to have HCC than HIV negative patients (33.5% vs 10.9%), [aOR =4.3, 95% CI (2.2-8.4)), P < 0.001]. Females have lower risk of HCC than males (32.7 vs 23.7) [aOR = 0.2, 95% CI (0.1-0.4), P < 0.001]. The majority of HCC patients were at the time of diagnosis at stages C (35.1%) and D (48.6%) according to the Barcelona Clinic Liver Clinic (BCLC) criteria. CONCLUSION: Liver cancer was more frequent among adults and subjects co-infected with HBV and HIV. Thus, HIV represents an additional risk factor for liver cancer in this Kenyan population. Regular health screening of HIV and HBV infected subjects may significantly improve the early diagnosis and effective therapy of liver cancer.

2.
J Cell Physiol ; 232(9): 2287-2295, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27800606

RESUMO

The objectives of the African Organization for Research and Training in Cancer (AORTIC), includes bringing products of decades of advances in cancer research to African populations through local and international collaboration. The consistent and huge growth in participation in the conferences and the diversity of the nations is a witness to the success of the organization thus far. The theme for the Tenth AORTIC International Conference on Cancer in Africa in Morocco in 2015 was "Road map to Cancer Control in Africa" and topics of discussion of paramount importance for low- and middle-income African countries included childhood cancers such as BL, cancers of the cervix, breast, and prostate; cancers associated with HIV-infection such as cervical, vulvar, and anal; as well as cancer care challenges associated with palliative care. The role of environmental factors that underlie some epigenetic changes in some of the cancers was emphasized. Oral and poster presentations from various parts of the continent indicate the growth of basic and translational science of cancer in the region, with studies revealing regional diversity in the frequencies of the triple-negative breast cancer, cervical cancer, prostate cancer, HCC, and Burkitt's lymphoma. There was a sign that Africa is trying to keep pace with the paradigm shift and focusing on translational medicine. This was shown by suggestions for application of genome-wide association studies, new generation sequencing, as well as the evaluation of single nucleotide polymorphisms that may be responsible for variable susceptibility in some of the prevalent cancers in people of African descent. J. Cell. Physiol. 232: 2287-2295, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Prestação Integrada de Cuidados de Saúde/organização & administração , Países em Desenvolvimento , Neoplasias/terapia , Pesquisa Translacional Biomédica/organização & administração , África/epidemiologia , Atitude do Pessoal de Saúde , Difusão de Inovações , Epigênese Genética , Predisposição Genética para Doença , Infecções por HIV/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Comunicação Interdisciplinar , Estilo de Vida , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Neoplasias/genética , Fenótipo , Prevalência , Prognóstico , Fatores de Risco
3.
Infect Agent Cancer ; 10: 28, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26306097

RESUMO

BACKGROUND: Sub-Sahara Africa hosts up to 71 % of all HIV infected people in the world. With this high incidence of Human immunodeficiency virus ( HIV) comes the burden of co-morbidities such as malignant and premalignant lesions. Aids defining malignancies have been listed as Kaposi's sarcoma, Non-Hodgkin's lymphoma and invasive squamous cell carcinoma of the cervix. People with HIV/AIDS(PLWAS) have a higher risk of developing these neoplasms than the rest of the population. The pathogenesis of these neoplasms in people with HIV has been linked to immune suppression, persistent antigenic stimulation and cytokine dysregulation. Current study analyzes and presents the patterns and trends in the presentation of HIV related malignancies in patients diagnosed through histopathology at Kenyatta National Hospital. AIM: To describe the patterns of AIDS- defining and non-AIDS- defining malignancies and premalignant lesions 10 years pre- and post HAART period at Kenyatta National hospital, Kenya. METHODS AND TECHNIQUES: This was a hospital based descriptive cross sectional study. The Formalin fixed paraffin embedded (FFPE) blocks and histological reports of patients diagnosed between 2000 and 2011 were traced from archives. The patients' demographic data and clinical presentation was entered in an excel spreadsheet and the diagnosis and coding confirmed by a histopathologist. The data was then cleaned and analyzed using SSPS version 17.0 Ink. RESULTS: A total of 173 lesions were reviewed and analyzed. Of these 118 (68 %) were from females and 55 from males (32 %). The male to female ratio was 1:2. The age range was from two to 56 years with a median of 36 years. Kaposi sarcoma is the leading AIDS defining malignancy in Kenya while invasive squamous cell carcinoma of the conjunctiva is the leading non-AIDS defining malignancy. This is closely followed by invasive squamous cell carcinoma of the cervix and NHL. CONCLUSION: Kaposi sarcoma is the leading AIDS associated neoplasm in Kenya. Physicians and caretakers managing and following up on HIV/AIDS patients should look out for Kaposi sarcoma as a form of IRIS following the institution of HAART in all HIV/AIDS patients. The incidence of invasive squamous cell carcinoma of the conjunctiva is increasing in PLWAS in Kenya. There is therefore a need to introduce early screening programs for squamous intraepithelial neoplasm of the conjunctiva in HIV/AIDS patients.

4.
PLoS One ; 10(5): e0125420, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25933165

RESUMO

Epstein-Barr virus (EBV) is associated with Burkitt's lymphoma (BL), and in regions of sub-Saharan Africa where endemic BL is common, both the EBV Type 1 (EBV-1) and EBV Type 2 strains (EBV-2) are found. Little is known about genetic variation of EBV strains in areas of sub-Saharan Africa. In the present study, spontaneous lymphoblastoid cell lines (LCLs) were generated from samples obtained from Kenya. Polymerase chain reaction (PCR) amplification of the EBV genome was done using multiple primers and sequenced by next-generation sequencing (NGS). Phylogenetic analyses against the published EBV-1 and EBV-2 strains indicated that one sample, LCL10 was closely related to EBV-2, while the remaining 3 LCL samples were more closely related to EBV-1. Moreover, single nucleotide polymorphism (SNP) analyses showed clustering of LCL variants. We further show by analysis of EBNA-1, BLLF1, BPLF1, and BRRF2 that latent genes are less conserved than lytic genes in these LCLs from a single geographic region. In this study we have shown that NGS is highly useful for deciphering detailed inter and intra-variations in EBV genomes and that within a geographic region different EBV genetic variations can co-exist, the implications of which warrant further investigation. The findings will enhance our understanding of potential pathogenic variants critical to the development and maintenance of EBV-associated malignancies.


Assuntos
Linfoma de Burkitt/virologia , Infecções por Vírus Epstein-Barr/virologia , Variação Genética , Genoma Viral , Herpesvirus Humano 4/genética , Linfócitos/virologia , Linfoma de Burkitt/complicações , Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/patologia , Linhagem Celular , Criança , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por Vírus Epstein-Barr/patologia , Antígenos Nucleares do Vírus Epstein-Barr/genética , Efeito Fundador , Expressão Gênica , Herpesvirus Humano 4/classificação , Herpesvirus Humano 4/patogenicidade , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Quênia/epidemiologia , Linfócitos/patologia , Filogenia , Proteínas Virais Reguladoras e Acessórias/genética
5.
J Infect Dis ; 212(11): 1735-42, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25985902

RESUMO

BACKGROUND: We previously reported that infants in Kenya were infected with Epstein-Barr virus (EBV) at <6 months of age, suggesting that mothers were the likely source of transmissible virus to the infant. In this study, we investigated whether breast milk contained infectious EBV and the role of malaria in EBV shedding in breast milk. METHODS: Breast milk samples were obtained from Kenyan mothers at postpartum weeks 6, 10, 14, and 18 and analyzed for presence of infectious EBV. RESULTS: We found that the prevalence of EBV DNA and the mean EBV load were significantly higher at 6 weeks and decreased through postpartum week 18 (P < .0001). High EBV load in breast milk correlated with mothers who had Plasmodium falciparum malaria at delivery. To determine whether viral DNA was encapsidated, breast milk samples were treated with DNAse before DNA extraction. Sixty percent of samples were DNAse resistant, suggesting that the viral DNA in breast milk was encapsidated. Next, we exposed peripheral blood mononuclear cells to breast milk supernatant, which resulted in the generation of EBV-positive lymphoblastoid cell lines, indicating that the virus in breast milk was infectious. CONCLUSIONS: Our data suggest that breast milk contains infectious EBV and is a potential source of viral transmission to infants living in malaria-endemic regions.


Assuntos
Infecções por Vírus Epstein-Barr/transmissão , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/genética , Leite Humano/virologia , DNA Viral/análise , Infecções por Vírus Epstein-Barr/epidemiologia , Feminino , Humanos , Lactente , Quênia/epidemiologia , Malária , Prevalência , Estudos Prospectivos , Carga Viral
6.
Matern Child Health J ; 19(3): 606-14, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24951129

RESUMO

The role of Plasmodium falciparum malaria in Epstein-Barr virus (EBV) transmission among infants early in life remain elusive. We hypothesized that infection with malaria during pregnancy could cause EBV reactivation leading to high EBV load in circulation, which could subsequently enhance early age of EBV infection. Pregnant women in Kisumu, where P. falciparum malaria is holoendemic, were actively followed monthly through antenatal visits (up to 4 per mother) and delivery. Using real-time quantitative (Q)-PCR, we quantified and compared EBV and P. falciparum DNA levels in the blood of pregnant women with and without P. falciparum malaria. Pregnant women that had malaria detected during pregnancy were more likely to have detectable EBV DNA than pregnant women who had no evidence of malaria infection during pregnancy (64 vs. 36 %, p = 0.01). EBV load as analyzed by quantifying area under the longitudinal observation curve (AUC) was significantly higher in pregnant women with P. falciparum malaria than in women without evidence of malaria infection (p = 0.01) regardless of gestational age of pregnancy. Increase in malaria load correlated with increase in EBV load (p < 0.0001). EBV load was higher in third trimester (p = 0.04) than first and second trimester of pregnancy independent of known infections. Significantly higher frequency and elevated EBV loads were found in pregnant women with malaria than in women without evidence of P. falciparum infection during pregnancy. The loss of control of EBV latency following P. falciparum infection during pregnancy and subsequent increase in EBV load in circulation could contribute to enhanced shedding of EBV in maternal saliva and breast milk postpartum, but further studies are needed.


Assuntos
DNA Viral/sangue , Herpesvirus Humano 4/genética , Malária Falciparum/sangue , Plasmodium falciparum/genética , Complicações Infecciosas na Gravidez/sangue , Adulto , DNA de Protozoário/sangue , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/complicações , Feminino , Humanos , Malária Falciparum/complicações , Parasitemia , Gravidez , Gestantes , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral
7.
Infect Agent Cancer ; 9: 28, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25225572

RESUMO

BACKGROUND: Oncoviruses such as HPV, KSHV, and EBV have been reported in patients with HIV infection and AIDS. How oncovirus-associated cancers rise in AIDS patients has not been fully established. The purpose of our study was to identify the viral agents in vulvar cancer and to assess their contribution to pathogenesis. METHOD: We retrospectively identified a total of 13 vulva tissue samples from HIV-1 positive and 9 vulvar samples from HIV-1 negative patients from the Botswana National Health Laboratory in Gaborone, Botswana, a Southern African country with a high incidence of HIV. We utilized PCR and IHC to identify HPV, EBV, KSHV, and JC virus in FFPE preserved tissue samples. RESULTS: Using the GP5(+)/GP6(+) primer set we detected several HPV types in tissue samples. EBV was detected in all of the positive cases (100%) and in most of the negative cases (89%). KSHV was detected in 39% of the HIV-1 positive samples and in 11% of the negative samples, and no JC virus was detected in any of the samples. Using IHC we demonstrated that LANA was expressed in 61% of the positive samples and in 44% of the negative samples. The ubiquitous EBV was more consistently expressed in negative cases (100%) than in positive cases (69%). Interestingly, the HPV-16 E6 transcript was detected in 56% of the negative samples compared to 31% of the positive samples. However, the cell cycle protein P21 used as a surrogate marker for HPV was detected in 77% of the positive samples and in 44% of the negative samples, while VEGF signals were similar in both positive (92%) and negative samples (89%). CONCLUSION: Our study, suggests that in Botswana, vulvar squamous cell carcinoma (VSCC) is associated with oncogenic viruses present in the niche but the contribution and progression may be regulated by HPV and other immunosuppressive infections that include HIV-1.

8.
Int J Gynecol Cancer ; 24(4): 758-65, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24651632

RESUMO

OBJECTIVE: The primary aim of this study was to describe the prevalence of select oncogenic viruses within vulvar squamous cell carcinoma (VSCC) and their association with human immunodeficiency virus (HIV) status in women in Botswana, where the national HIV prevalence is the third highest in the world. METHODS: A cross-sectional study of biopsy-confirmed VSCC specimens and corresponding clinical data was conducted in Gaborone, Botswana. Polymerase chain reaction (PCR) and immunohistochemistry (IHC) viral testing were done for Epstein-Barr virus, human papillomavirus (HPV) strains, and Kaposi sarcoma herpesvirus, and PCR viral testing alone was done for John Cunningham virus. RESULTS: Human papillomavirus prevalence by PCR was 100% (35/35) among tested samples. Human papillomavirus type 16 was the most prevalent HPV strain (82.9% by PCR, 94.7% by either PCR or IHC). Kaposi sarcoma herpesvirus prevalence by PCR had a significant association with HIV status (P = 0.013), but not by IHC (P = 0.650). CONCLUSIONS: The high burden of HPV, specifically HPV16, in vulvar squamous cell cancer in Botswana suggests a distinct HPV profile that differs from other studied populations, which provides increased motivation for HPV vaccination efforts. Oncogenic viruses Kaposi sarcoma herpesvirus and Epstein-Barr virus were also more prevalent in our study population, although their potential role in vulvar squamous cell cancer pathology is unclear.


Assuntos
Carcinoma de Células Escamosas/virologia , Infecções por HIV/complicações , HIV/isolamento & purificação , Papillomaviridae/genética , Infecções por Papillomavirus/complicações , Neoplasias Vulvares/virologia , Adolescente , Adulto , Botsuana/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/patologia , Estudos Transversais , DNA Viral/genética , Feminino , Seguimentos , HIV/genética , Infecções por HIV/virologia , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Prevalência , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Neoplasias Vulvares/epidemiologia , Neoplasias Vulvares/patologia , Adulto Jovem
9.
Ecancermedicalscience ; 8: 396, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24550997

RESUMO

The objectives of the African Organisation for Research and Training in Cancer (AORTIC), both at its inception in the early 1980s, and at its reactivation in 2000 following a decade of inactivity, included bringing the products of decades of advances in cancer research to African populations through international collaboration. The historical perspective provided in this report illustrates progress in achieving these objectives through successive continent-wide activities over a period of 30 years, culminating in the organisation's most recent conference held in Durban, South Africa, 21-24 November 2013. The constant growth in the number of attendants and increasing diversity of the nations of their origin are consistent with advances, whereby the number of participants and the nations of their origin have grown from 24 in 1983 to almost 1000 in 2013, and from 14 to 70, respectively. While earlier AORTIC conferences used to assume the atmosphere of 'jamborees', more recent ones have morphed to problem-solving events, with the concerted collaboration of international organisations, including the World Health Organisation (WHO), International Union Against Cancer (UICC), the Africa Union (AU), the US National Cancer Institute (NCI), the International Psycho-Oncology Society (IPOS), and others. The topics of discussion at the Ninth AORTIC International Conference on Cancer in Africa in Durban were those of paramount importance for low- and middle-income countries: childhood cancers, cancers of the cervix, breast, and prostate, as well as cancer care challenges resulting from ignorance, neglect, and economic deprivation. The role of environmental factors that underlie Burkitt's lymphoma was the subject of the Epidemiology of Burkitt Lymphoma in East-African Children and Minors Workshop, highlighting the NCI research programme in East Africa, while the Workshop on Cost Effectiveness of Treatment of Cancer in Africa surmised that treating childhood cancers is affordable in Africa in spite of widespread economic deprivation. WHO representatives emphasised the organisation's commitment to the global control of non-communicable diseases (NCDs), including cancer, and promoted the new initiatives for the control of cervical cancer, one of the commonest and deadliest cancers in adult Africans. AU representative proffered the principles of 'demographic dividends' for Africa to be able to tackle its burden of NCDs. UICC, represented by its President, provided guidelines for cancer diagnosis and staging, and advised on its effort to improve global access to radiotherapy, especially in Africa, while IPOS led the discussions on mitigating the suffering that is associated with the late presentation of cancer in the region. Oral and poster presentations from various parts of the continent indicate the growth of basic science of cancer in the region, with studies revealing regional diversity in the frequencies of the triple-negative breast cancer. They also suggest a need for genome-wide association studies as well as the evaluation of single nucleotide polymorphisms that may be responsible for variable susceptibility in breast and prostate cancer in people of African descent. Finally, the AORTIC leadership announced its plan for the advancement of cancer control by intensifying cancer advocacy at all levels of governance in the region.

10.
Infect Agent Cancer ; 9: 32, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25686906

RESUMO

A one-day workshop on Burkitt lymphoma (BL) was held at the 9(th) African Organization for Research and Training in Cancer (AORTIC) conference in 2013 in Durban, South Africa. The workshop featured 15 plenary talks by delegates representing 13 institutions that either fund or implement research on BL targeting AORTIC delegates primarily interested in pediatric oncology. The main outcomes of the meeting were improved sharing of knowledge and experience about ongoing epidemiologic BL research, BL treatment in different settings, the role of cancer registries in cancer research, and opportunities for African scientists to publish in scientific journals. The idea of forming a consortium of BL to improve coordination, information sharing, accelerate discovery, dissemination, and translation of knowledge and to build capacity, while reducing redundant efforts was discussed. Here, we summarize the presentations and discussions from the workshop.

11.
Arch Dermatol ; 148(2): 219-23, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22351821

RESUMO

BACKGROUND: Viral-associated trichodysplasia of immunosuppression is a rare cutaneous eruption that is characterized by follicularly based shiny papules and alopecia with characteristic histopathologic findings of abnormally anagen follicules with excessive inner root sheath differentiation. Prior reports have described the histopathologic characteristics on vertical sections; however, to our knowledge, immunohistochemical analysis of polyomavirus proteins has not been previously performed. OBSERVATIONS: We discuss the thorough diagnostic evaluation and therapy of an unusual case of viral-associated trichodysplasia due to a newly described human polyomavirus that occurred in a patient with posttreatment chronic lymphocytic leukemia and an abnormal white blood cell count. Unique to our study is the immunohistochemical staining for the polyomavirus middle T antigen, which demonstrated positive staining of cellular inclusions within keratinocytes that compose the inner root sheath. Further evaluation with scanning electron microscopy and polymerase chain reaction analysis of viral DNA confirmed the presence of the virus. Treatment with topical cidofovir resulted in dramatic clinical improvement and hair regrowth. CONCLUSIONS: Several tools, including immunohistochemical staining for the polyomavirus middle T antigen, can be used to identify the pathogenic virus associated with viral-associated trichodysplasia. This case highlights the utility of multiple diagnostic modalities and a robust response to a topical therapeutic agent, cidofovir.


Assuntos
Antivirais/uso terapêutico , Citosina/análogos & derivados , DNA Viral/análise , Doenças do Cabelo/tratamento farmacológico , Organofosfonatos/uso terapêutico , Infecções por Polyomavirus/tratamento farmacológico , Cidofovir , Citosina/uso terapêutico , Feminino , Doenças do Cabelo/patologia , Doenças do Cabelo/virologia , Folículo Piloso/química , Folículo Piloso/patologia , Folículo Piloso/virologia , Humanos , Pessoa de Meia-Idade , Polyomavirus , Infecções por Polyomavirus/metabolismo , Infecções por Polyomavirus/patologia
12.
Infect Agent Cancer ; 5: 6, 2010 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-20346104

RESUMO

BACKGROUND: Ocular surface squamous neoplasia (OSSN) is a rare cancer that has increased in incidence with the HIV pandemic in Africa. The underlying cause of this cancer in HIV-infected patients from Botswana is not well defined. RESULTS: Tissues were obtained from 28 OSSN and 8 pterygia patients. The tissues analyzed from OSSN patients were 83% positive for EBV, 75% were HPV positive, 70% were KSHV positive, 75% were HSV-1/2 positive, and 61% were CMV positive by PCR. Tissues from pterygium patients were 88% positive for EBV, 75% were HPV positive, 50% were KSHV positive, and 60% were CMV positive. None of the patients were JC or BK positive. In situ hybridization and immunohistochemistry analyses further identified HPV, EBV, and KSHV in a subset of the tissue samples. CONCLUSION: We identified the known oncogenic viruses HPV, KSHV, and EBV in OSSN and pterygia tissues. The presence of these tumor viruses in OSSN suggests that they may contribute to the development of this malignancy in the HIV population. Further studies are necessary to characterize the molecular mechanisms associated with viral antigens and their potential role in the development of OSSN.

13.
J Immigr Minor Health ; 12(4): 569-79, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19199112

RESUMO

OBJECTIVES: To describe the social and cultural differences between Anglophone and Francophone African immigrants which define the impediments that Francophone African immigrants face trying to access health and human services in Philadelphia, Pennsylvania. METHODS: Surveys and personal interviews were administered to participants in social events, community meetings, and health centers. A Chi-squared analysis was used to contrast the communities. RESULTS: Francophone Africans demonstrated less acculturation, education, English fluency, and more legal documentation problems, and thus face greater challenges accessing health care. Anglophone Africans had a higher level of acculturation, fewer language problems, and perceived fewer barriers in accessing health care than Francophone Africans. CONCLUSIONS: Educating new immigrants, through a more culturally sensitive infectious disease treatment and prevention program, is integral to achieving a higher access and utilization rates of available services; especially in recent Francophone immigrants. A larger study is needed to extend the findings to other cities where immigrants with similar backgrounds or acculturation issues reside.


Assuntos
Infecções por HIV/etnologia , Acessibilidade aos Serviços de Saúde , Serviço Social , Adolescente , Adulto , África/etnologia , Cultura , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Philadelphia , Inquéritos e Questionários , Adulto Jovem
14.
J Gen Virol ; 88(Pt 2): 631-640, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17251582

RESUMO

Transcriptional regulation of the human immunodeficiency virus type 1 (HIV-1) is a complex event that requires the cooperative action of both viral (e.g. Tat) and cellular (e.g. C/EBPbeta, NF-kappaB) factors. The HIV-1 Tat protein recruits the human positive transcription elongation factor P-TEFb, consisting of cdk9 and cyclin T1, to the HIV-1 transactivation response (TAR) region. In the absence of TAR, Tat activates the HIV-1 long terminal repeat (LTR) through its association with several cellular factors including C/EBPbeta. C/EBPbeta is a member of the CCAAT/enhancer-binding protein family of transcription factors and has been shown to be a critical transcriptional regulator of HIV-1 LTR. We examined whether Tat-C/EBPbeta association requires the presence of the P-TEFb complex. Using immunoprecipitation followed by Western blot, we demonstrated that C/EBPbeta-cyclin T1 association requires the presence of cdk9. Further, due to its instability, cdk9 was unable to physically interact with C/EBPbeta in the absence of cyclin T1 or Tat. Using kinase assays, we demonstrated that cdk9, but not a cdk9 dominant-negative mutant (cdk9-dn), phosphorylates C/EBPbeta. Our functional data show that co-transfection of C/EBPbeta and cdk9 leads to an increase in HIV-1 gene expression when compared to C/EBPbeta alone. Addition of C/EBP homologous protein (CHOP) inhibits C/EBPbeta transcriptional activity in the presence and absence of cdk9 and causes a delay in HIV-1 replication in T-cells. Together, our data suggest that Tat-C/EBPbeta association is mediated through cdk9, and that phosphorylated C/EBPbeta may influence AIDS progression by increasing expression of HIV-1 genes.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Quinase 9 Dependente de Ciclina/metabolismo , Regulação Viral da Expressão Gênica , Produtos do Gene tat/metabolismo , HIV-1/patogenicidade , Proteína beta Intensificadora de Ligação a CCAAT/genética , Linhagem Celular Tumoral , Ciclina T , Quinase 9 Dependente de Ciclina/genética , Ciclinas/genética , Ciclinas/metabolismo , Produtos do Gene tat/genética , Humanos , Transfecção , Células U937 , Produtos do Gene tat do Vírus da Imunodeficiência Humana
15.
J Neuroimmunol ; 176(1-2): 174-80, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16750572

RESUMO

HIV-1 infection of the central nervous system (CNS) is associated with dysregulation of several important cytokines and chemokines, which are involved in inflammatory process. Earlier studies ascribed a critical role for Tat, a potent viral transcription activator, in this process by enhancing the expression of several immunomodulators including TGFbeta and MCP-1. Investigation of signaling pathways which are controlled by these cytokines led to identification of MH2 domain of Smad3, the downstream activator of TGFbeta pathway, as a modulator of MCP-1 promoter activity. The level of MCP-1 is increased in AIDS patients with neurologic problems, through recruitment of inflammatory cells, which can contribute to neuropathogenesis of AIDS. Therefore, we attempted to investigate the effect of MH2 on expression of MCP-1 and other immunolmodulators in CNS cells. By employing an adenovirus expression vector, we demonstrated that MH2 can decrease the levels of Tat-induced activation of MCP-1 and several other cytokines and chemokines in astrocytic cells. In addition, we showed that MH2 significantly reduced the activity of cytokines produced by cultures of adenovirus-MH2 transduced cells as measured by the transmigration of human PBMC cells. Thus, MH2 domain of Smad3 is a potential agent that may be developed as an inhibitor for the cytokine-mediated inflammatory responses in the brain and may have the potential to prevent transmigration of HIV-1-infected monocytes across the blood brain barrier in AIDS patients.


Assuntos
Citocinas/biossíntese , Produtos do Gene tat/toxicidade , HIV-1/patogenicidade , Proteína Smad3/química , Proteína Smad3/fisiologia , Complexo AIDS Demência/etiologia , Adenoviridae/genética , Quimiocina CCL2/genética , Humanos , Células U937 , Produtos do Gene tat do Vírus da Imunodeficiência Humana
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