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1.
Sex Transm Infect ; 99(8): 534-540, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37607814

RESUMO

BACKGROUND: The potential of HIV self-testing (HIVST) to cause harm is a concern hindering widespread implementation. The aim of this paper is to understand the relationship between HIVST and harm in SELPHI (An HIV Self-testing Public Health Intervention), the largest randomised trial of HIVST in a high-income country to date. METHODS: 10 111 cis and trans men who have sex with men (MSM) recruited online (geolocation social/sexual networking apps, social media), aged 16+, reporting previous anal intercourse and resident in England or Wales were first randomised 60/40 to baseline HIVST (baseline testing, BT) or not (no baseline testing, nBT) (randomisation A). BT participants reporting negative baseline test, sexual risk at 3 months and interest in further HIVST were randomised to three-monthly HIVST (repeat testing, RT) or not (no repeat testing, nRT) (randomisation B). All received an exit survey collecting data on harms (to relationships, well-being, false results or being pressured/persuaded to test). Nine participants reporting harm were interviewed in-depth about their experiences in an exploratory substudy; qualitative data were analysed narratively. RESULTS: Baseline: predominantly cis MSM, 90% white, 88% gay, 47% university educated and 7% current/former pre-exposure prophylaxis (PrEP) users. Final survey response rate was: nBT=26% (1056/4062), BT=45% (1674/3741), nRT=41% (471/1147), RT=50% (581/1161).Harms were rare and reported by 4% (n=138/3691) in exit surveys, with an additional two false positive results captured in other study surveys. 1% reported harm to relationships and to well-being in BT, nRT and RT combined. In all arms combined, being pressured or persuaded to test was reported by 1% (n=54/3678) and false positive results in 0.7% (n=34/4665).Qualitative analysis revealed harms arose from the kit itself (technological harms), the intervention (intervention harms) or from the social context of the participant (socially emergent harms). Intervention and socially emergent harms did not reduce HIVST acceptability, whereas technological harms did. DISCUSSION: HIVST harms were rare but strategies to link individuals experiencing harms with psychosocial support should be considered for HIVST scale-up. TRIAL REGISTRATION NUMBER: ISRCTN20312003.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Masculino , Humanos , Homossexualidade Masculina , Autoteste , HIV , País de Gales , Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Inglaterra
2.
Lancet ; 389(10071): 815-822, 2017 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-28110982

RESUMO

BACKGROUND: Men with high serum prostate specific antigen usually undergo transrectal ultrasound-guided prostate biopsy (TRUS-biopsy). TRUS-biopsy can cause side-effects including bleeding, pain, and infection. Multi-parametric magnetic resonance imaging (MP-MRI) used as a triage test might allow men to avoid unnecessary TRUS-biopsy and improve diagnostic accuracy. METHODS: We did this multicentre, paired-cohort, confirmatory study to test diagnostic accuracy of MP-MRI and TRUS-biopsy against a reference test (template prostate mapping biopsy [TPM-biopsy]). Men with prostate-specific antigen concentrations up to 15 ng/mL, with no previous biopsy, underwent 1·5 Tesla MP-MRI followed by both TRUS-biopsy and TPM-biopsy. The conduct and reporting of each test was done blind to other test results. Clinically significant cancer was defined as Gleason score ≥4 + 3 or a maximum cancer core length 6 mm or longer. This study is registered on ClinicalTrials.gov, NCT01292291. FINDINGS: Between May 17, 2012, and November 9, 2015, we enrolled 740 men, 576 of whom underwent 1·5 Tesla MP-MRI followed by both TRUS-biopsy and TPM-biopsy. On TPM-biopsy, 408 (71%) of 576 men had cancer with 230 (40%) of 576 patients clinically significant. For clinically significant cancer, MP-MRI was more sensitive (93%, 95% CI 88-96%) than TRUS-biopsy (48%, 42-55%; p<0·0001) and less specific (41%, 36-46% for MP-MRI vs 96%, 94-98% for TRUS-biopsy; p<0·0001). 44 (5·9%) of 740 patients reported serious adverse events, including 8 cases of sepsis. INTERPRETATION: Using MP-MRI to triage men might allow 27% of patients avoid a primary biopsy and diagnosis of 5% fewer clinically insignificant cancers. If subsequent TRUS-biopsies were directed by MP-MRI findings, up to 18% more cases of clinically significant cancer might be detected compared with the standard pathway of TRUS-biopsy for all. MP-MRI, used as a triage test before first prostate biopsy, could reduce unnecessary biopsies by a quarter. MP-MRI can also reduce over-diagnosis of clinically insignificant prostate cancer and improve detection of clinically significant cancer. FUNDING: PROMIS is funded by the UK Government Department of Health, National Institute of Health Research-Health Technology Assessment Programme, (Project number 09/22/67). This project is also supported and partly funded by UCLH/UCL Biomedical Research Centre and The Royal Marsden and Institute for Cancer Research Biomedical Research Centre and is coordinated by the Medical Research Council Clinical Trials Unit (MRC CTU) at UCL. It is sponsored by University College London (UCL).


Assuntos
Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética , Neoplasias da Próstata/diagnóstico , Ultrassonografia de Intervenção , Humanos , Masculino , Gradação de Tumores , Estudos Prospectivos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Sensibilidade e Especificidade
3.
AIDS ; 38(10): 1513-1522, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38819839

RESUMO

OBJECTIVE: Metabolic dysfunction associated fatty liver disease (MAFLD) is over-represented in people with HIV (PWH). Maraviroc (MVC) and/or metformin (MET) may reduce MAFLD by influencing inflammatory pathways and fatty acid metabolism. DESIGN: Open-label, 48-week randomized trial with a 2 x 2 factorial design. SETTING: Multicenter HIV clinics. PARTICIPANTS: Nondiabetic, virologically suppressed PLWH, aged at least 35 years, with confirmed/suspected MAFLD (≥1 biochemical/anthropometric/radiological/histological features). INTERVENTION: Adjunctive MVC; MET; MVC+MET vs. antiretroviral therapy (ART) alone. PRIMARY OUTCOME: Change in liver fat fraction (LFF) between baseline and week-48 using magnetic resonance proton density fat fraction (MR PDFF). RESULTS: Six sites enrolled 90 participants (93% male; 81% white; median age 52 [interquartile range, IQR 47-57] years) between March 19, 2018, and November 11, 2019. Seventy percent had imaging/biopsy and at least one 1 MAFLD criteria. The analysis included 82/90 with week-0 and week-48 scans. Median baseline MR PDFF was 8.9 (4.6-17.1); 40, 38, 8, and 14% had grade zero, one, two, and three steatosis, respectively. Mean LFF increased slightly between baseline and follow-up scans: 2.22% MVC, 1.26% MET, 0.81% MVC+MET, and 1.39% ART alone. Prolonged intervention exposure (delayed week-48 scans) exhibited greater increases in MR PDFF (estimated difference 4.23% [95% confidence interval, 95% CI 2.97-5.48], P  < 0.001). There were no differences in predicted change for any intervention compared to ART alone: MVC (-0.42% [95% CI -1.53 to 0.68, P  = 0.45]), MET (-0.62 [-1.81 to 0.56, P  = 0.30]), and MVC+MET (-1.04 [-2.74 to 0.65, P  = 0.23]). Steatosis grade remained unchanged in 55% and increased in 24%. CONCLUSION: Baseline levels of liver fat were lower than predicted. Contrary to our hypothesis, neither MVC, MET, or the combination significantly reduced liver fat as measured by MRPDFF compared to ART alone.


Assuntos
Infecções por HIV , Maraviroc , Metformina , Humanos , Maraviroc/uso terapêutico , Masculino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/complicações , Metformina/uso terapêutico , Feminino , Pessoa de Meia-Idade , Adulto , Resultado do Tratamento , Hipoglicemiantes/uso terapêutico , Fígado Gorduroso/tratamento farmacológico
4.
JAMA ; 308(4): 353-61, 2012 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-22820788

RESUMO

CONTEXT: Therapies to decrease immune activation might be of benefit in slowing HIV disease progression. OBJECTIVE: To determine whether hydroxychloroquine decreases immune activation and slows CD4 cell decline. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind, placebo-controlled trial performed at 10 HIV outpatient clinics in the United Kingdom between June 2008 and February 2011. The 83 patients enrolled had asymptomatic HIV infection, were not taking antiretroviral therapy, and had CD4 cell counts greater than 400 cells/µL. INTERVENTION: Hydroxychloroquine, 400 mg, or matching placebo once daily for 48 weeks. MAIN OUTCOME MEASURES: The primary outcome measure was change in the proportion of activated CD8 cells (measured by the expression of CD38 and HLA-DR surface markers), with CD4 cell count and HIV viral load as secondary outcomes. Analysis was by intention to treat using mixed linear models. RESULTS: There was no significant difference in CD8 cell activation between the 2 groups (-4.8% and -4.2% in the hydroxychloroquine and placebo groups, respectively, at week 48; difference, -0.6%; 95% CI, -4.8% to 3.6%; P = .80). Decline in CD4 cell count was greater in the hydroxychloroquine than placebo group (-85 cells/µL vs -23 cells/µL at week 48; difference, -62 cells/µL; 95% CI, -115 to -8; P = .03). Viral load increased in the hydroxychloroquine group compared with placebo (0.61 log10 copies/mL vs 0.23 log10 copies/mL at week 48; difference, 0.38 log10 copies/mL; 95% CI, 0.13 to 0.63; P = .003). Antiretroviral therapy was started in 9 patients in the hydroxychloroquine group and 1 in the placebo group. Trial medication was well tolerated, but more patients reported influenza-like illness in the hydroxychloroquine group compared with the placebo group (29% vs 10%; P = .03). CONCLUSION: Among HIV-infected patients not taking antiretroviral therapy, the use of hydroxychloroquine compared with placebo did not reduce CD8 cell activation but did result in a greater decline in CD4 cell count and increased viral replication. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN30019040.


Assuntos
Anti-Inflamatórios/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Hidroxicloroquina/uso terapêutico , Ativação Linfocitária/efeitos dos fármacos , Adolescente , Adulto , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4 , Linfócitos T CD8-Positivos , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Inflamação/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais , Resultado do Tratamento , Carga Viral , Adulto Jovem
5.
Lancet HIV ; 9(12): e838-e847, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36460023

RESUMO

BACKGROUND: High levels of HIV testing in men who have sex with men remain key to reducing the incidence of HIV. We aimed to assess whether the offer of a single, free HIV self-testing kit led to increased HIV diagnoses with linkage to care. METHODS: SELPHI was an internet-based, open-label, randomised controlled trial that recruited participants via sexual and social networking sites. Eligibility criteria included being a man or trans woman (although trans women are reported separately); being resident in England or Wales, UK; being aged 16 years or older; having had anal intercourse with a man; not having a positive HIV diagnosis; and being willing to provide name, email address, date of birth, and consent to link to national HIV databases. Participants were randomly allocated (3:2) by computer-generated number sequence to receive a free HIV self-test kit (BT group) or to not receive this free kit (nBT group). Online surveys collected data at baseline, 2 weeks after enrolment (BT group only), 3 months after enrolment, and at the end of the study. The primary outcome was confirmed (linked to care) new HIV diagnosis within 3 months of enrolment, analysed by intention to treat. Those assessing the primary outcome were masked to allocation. This study is registered with the ISRCTN Clinical Trials Register, number ISRCTN20312003. FINDINGS: 10 111 participants (6049 in BT group and 4062 in nBT group) enrolled between Feb 16, 2017, and March 1, 2018. The median age of participants was 33 years (IQR 26-44 years); 9000 (89%) participants were White; 8118 (80%) participants were born in the UK; 81 (1%) participants were transgender men; 4706 (47%) participants were university educated; 1537 (15%) participants had never been tested for HIV; and 389 (4%) participants were taking pre-exposure prophylaxis. At enrolment, 7282 (72%) participants reported condomless anal sex with at least one male partner in the previous 3 months. In the BT group, of the 4511 participants for whom HIV testing information was available, 4263 (95%) reported having used the free HIV self-test kit within 3 months.Within 3 months of enrolment there were 19 confirmed new HIV diagnoses (0·31%) in 6049 participants in the BT group and 15 (0·37%) of 4062 in the nBT group (p=0·64). INTERPRETATION: The offer of a single, free HIV self-test did not lead to increased rates of new HIV diagnoses, which could reflect decreasing HIV incidence rates in the UK. Nonetheless, the offer of a free HIV self-testing kit resulted in high HIV testing rates, indicating that self-testing is an attractive testing option for a large group of men who have sex with men. FUNDING: UK National Institute for Health and Care Research.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Feminino , Masculino , Humanos , Adulto , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Autoteste , País de Gales/epidemiologia , Homossexualidade Masculina , Teste de HIV , Comportamento Sexual , Internet
6.
EClinicalMedicine ; 32: 100700, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33681732

RESUMO

BACKGROUND: Globally, trans people are disproportionately affected by HIV, but research on strategies to increase testing are limited. SELPHI is a randomised-controlled-trial (RCT) of 10,135 cis men, trans men, and trans women reporting lifetime anal intercourse with male partners (cis or trans), evaluating whether the offer of free HIV self-testing (HIVST) increases diagnosis. This subgroup analysis from the SELPHI RCT aims to describe key HIVST outcomes and HIVST acceptability for trans people. METHODS: SELPHI recruited using social networking and trans focused social media. Participants were randomised 60/40 to baseline HIVST (Biosure™) (BT) vs no baseline HIVST (nBT); and at 3-months (if completed the survey and reported recent CAI) 50/50 to 3-monthly HIVST (RT) vs no repeat HIVST (nRT). Outcomes were self-reported through online surveys. We conducted a qualitative study of semi-structured peer-led participant interviews (n = 20) exploring HIVST motivations and experiences. These were analysed using a framework approach. FINDINGS: SELPHI recruited and randomised 118 trans men and trans women (94 trans men, 24 trans women), of whom 20 (16 trans men, 4 trans women) underwent the second randomisation. Median age at baseline was 29 (IQR: 22, 37), 79% were white, 79% were UK born, 37% had degree level education, and 31% had never tested for HIV. 62% (n = 59) of trans men completed the 3-month survey, but survey completion by trans women in nBT was too low (1/11) for randomised comparison. In trans men HIV testing uptake by 3 months was significantly higher in BT (95% 36/38) vs nBT (29%, 6/21) (RR=3.32 (1.68, 6.55) p<0.001). Trans people randomised to RT reported 3 times higher rate of HIV testing compared to nRT during the two-year follow-up (IRR 3.66 (1.86, 8.01) p<0.0001). STI testing frequency (mean number of tests during each 13 week period/ 2-year follow-up) was not significantly different across interventions: RT (0.03) and nRT (0.01) (IRR=1.86 95%CI; 0.77, 5.15; p = 0.15). Social harms were rare. Acceptability was very high in BT: 97% (38/39) found instructions easy to understand, 97% (37/38) found the HIVST simple to use and 100% (39/39) reported good overall experience. In interviews, reported HIVST benefits included increased autonomy, privacy, convenience and avoidance of health care providers perceived to be discriminatory and services that increased dysphoria. Minor lancet and test processing issues were reported. INTERPRETATION: HIVST significantly increased testing uptake and frequency in trans men and trans people overall, although recruitment and retention of trans women was low. HIVST acceptability was high and indicates easy access to this novel technology may increase HIV testing access for this key population.

7.
Health Technol Assess ; 22(39): 1-176, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30040065

RESUMO

BACKGROUND: Men with suspected prostate cancer usually undergo transrectal ultrasound (TRUS)-guided prostate biopsy. TRUS-guided biopsy can cause side effects and has relatively poor diagnostic accuracy. Multiparametric magnetic resonance imaging (mpMRI) used as a triage test might allow men to avoid unnecessary TRUS-guided biopsy and improve diagnostic accuracy. OBJECTIVES: To (1) assess the ability of mpMRI to identify men who can safely avoid unnecessary biopsy, (2) assess the ability of the mpMRI-based pathway to improve the rate of detection of clinically significant (CS) cancer compared with TRUS-guided biopsy and (3) estimate the cost-effectiveness of a mpMRI-based diagnostic pathway. DESIGN: A validating paired-cohort study and an economic evaluation using a decision-analytic model. SETTING: Eleven NHS hospitals in England. PARTICIPANTS: Men at risk of prostate cancer undergoing a first prostate biopsy. INTERVENTIONS: Participants underwent three tests: (1) mpMRI (the index test), (2) TRUS-guided biopsy (the current standard) and (3) template prostate mapping (TPM) biopsy (the reference test). MAIN OUTCOME MEASURES: Diagnostic accuracy of mpMRI, TRUS-guided biopsy and TPM-biopsy measured by sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) using primary and secondary definitions of CS cancer. The percentage of negative magnetic resonance imaging (MRI) scans was used to identify men who might be able to avoid biopsy. RESULTS: Diagnostic study - a total of 740 men were registered and 576 underwent all three tests. According to TPM-biopsy, the prevalence of any cancer was 71% [95% confidence interval (CI) 67% to 75%]. The prevalence of CS cancer according to the primary definition (a Gleason score of ≥ 4 + 3 and/or cancer core length of ≥ 6 mm) was 40% (95% CI 36% to 44%). For CS cancer, TRUS-guided biopsy showed a sensitivity of 48% (95% CI 42% to 55%), specificity of 96% (95% CI 94% to 98%), PPV of 90% (95% CI 83% to 94%) and NPV of 74% (95% CI 69% to 78%). The sensitivity of mpMRI was 93% (95% CI 88% to 96%), specificity was 41% (95% CI 36% to 46%), PPV was 51% (95% CI 46% to 56%) and NPV was 89% (95% CI 83% to 94%). A negative mpMRI scan was recorded for 158 men (27%). Of these, 17 were found to have CS cancer on TPM-biopsy. Economic evaluation - the most cost-effective strategy involved testing all men with mpMRI, followed by MRI-guided TRUS-guided biopsy in those patients with suspected CS cancer, followed by rebiopsy if CS cancer was not detected. This strategy is cost-effective at the TRUS-guided biopsy definition 2 (any Gleason pattern of ≥ 4 and/or cancer core length of ≥ 4 mm), mpMRI definition 2 (lesion volume of ≥ 0.2 ml and/or Gleason score of ≥ 3 + 4) and cut-off point 2 (likely to be benign) and detects 95% (95% CI 92% to 98%) of CS cancers. The main drivers of cost-effectiveness were the unit costs of tests, the improvement in sensitivity of MRI-guided TRUS-guided biopsy compared with blind TRUS-guided biopsy and the longer-term costs and outcomes of men with cancer. LIMITATIONS: The PROstate Magnetic resonance Imaging Study (PROMIS) was carried out in a selected group and excluded men with a prostate volume of > 100 ml, who are less likely to have cancer. The limitations in the economic modelling arise from the limited evidence on the long-term outcomes of men with prostate cancer and on the sensitivity of MRI-targeted repeat biopsy. CONCLUSIONS: Incorporating mpMRI into the diagnostic pathway as an initial test prior to prostate biopsy may (1) reduce the proportion of men having unnecessary biopsies, (2) improve the detection of CS prostate cancer and (3) increase the cost-effectiveness of the prostate cancer diagnostic and therapeutic pathway. The PROMIS data set will be used for future research; this is likely to include modelling prognostic factors for CS cancer, optimising MRI scan sequencing and biomarker or translational research analyses using the blood and urine samples collected. Better-quality evidence on long-term outcomes in prostate cancer under the various management strategies is required to better assess cost-effectiveness. The value-of-information analysis should be developed further to assess new research to commission. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16082556 and NCT01292291. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 39. See the NIHR Journals Library website for further project information. This project was also supported and partially funded by the NIHR Biomedical Research Centre at University College London (UCL) Hospitals NHS Foundation Trust and UCL and by The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research Biomedical Research Centre and was co-ordinated by the Medical Research Council's Clinical Trials Unit at UCL (grant code MC_UU_12023/28). It was sponsored by UCL. Funding for the additional collection of blood and urine samples for translational research was provided by Prostate Cancer UK.


Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/economia , Imageamento por Ressonância Magnética/economia , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Estudos de Coortes , Análise Custo-Benefício , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/normas , Humanos , Imageamento por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Anos de Vida Ajustados por Qualidade de Vida , Grupos Raciais , Sensibilidade e Especificidade , Medicina Estatal , Reino Unido
8.
PLoS One ; 12(4): e0175596, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28426834

RESUMO

BACKGROUND: PROUD participants were randomly assigned to receive pre-exposure prophylaxis (PrEP) immediately or after a deferred period of one-year. We report on the acceptability of this open-label wait-listed trial design. METHODS: Participants completed an acceptability questionnaire, which included categorical study acceptability data and free-text data on most and least liked aspects of the study. We also conducted in-depth interviews (IDI) with a purposely selected sub-sample of participants. RESULTS: Acceptability questionnaires were completed by 76% (415/544) of participants. After controlling for age, immediate-group participants were almost twice as likely as deferred-group participants to complete the questionnaire (AOR:1.86;95%CI:1.24,2.81). In quantitative data, the majority of participants in both groups found the wait-listed design acceptable when measured by satisfaction of joining the study, intention to remain in the study, and interest in joining a subsequent study. However, three-quarters thought that the chance of being in the deferred-group might put other volunteers off joining the study. In free-text responses, data collection tools were the most frequently reported least liked aspect of the study. A fifth of deferred participants reported 'being deferred' as the thing they least liked about the study. However, more deferred participants disliked the data collection tools than the fact that they had to wait a year to access PrEP. Participants in the IDIs had a good understanding of the rationale for the open-label wait-listed study design. Most accepted the design but acknowledged they were, or would have been, disappointed to be randomised to the deferred group. Five of the 25 participants interviewed reported some objection to the wait-listed design. CONCLUSION: The quantitative and qualitative findings suggest that in an environment where PrEP was not available, the rationale for the wait-listed trial design was well understood and generally acceptable to most participants in this study.


Assuntos
Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição , Listas de Espera , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Brain Res Mol Brain Res ; 109(1-2): 189-97, 2002 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-12531528

RESUMO

Superoxide dismutase plays a key role in cell protection against the damaging effects of superoxide. Mutations in the copper/zinc dependent intracellular form of superoxide dismutase (SOD1) are associated with a subset of cases of familial amyotrophic lateral sclerosis (FALS). In this study we have investigated the effects of over-expressing wild-type SOD1 and two mutant forms of SOD1 found in FALS, G93A and G93R, on cell survival using stably transfected neuronal cells. G93R is associated with early age of onset and severely reduced erythrocyte SOD1 enzyme activity. Overexpression of wild-type SOD1 in ND7 cells significantly enhanced cell survival and reduced apoptosis after serum deprivation. Conversely, cells expressing the G93R mutation of SOD1 exhibited significantly increased cell death and increased number of TUNEL-positive cells, having a more profound effect than G93A SOD1 expressing cells, thus reflecting the relative clinical severity of these mutations. The effects of three further apoptotic and nonapoptotic death-inducing paradigms were investigated, hypoxia with reperfusion, staurosporine and gamma-interferon induced cell death. With each paradigm, cell death was significantly reduced by overexpression of wild-type SOD1 and increased by overexpression of the SOD1 mutations G93A and G93R. We further used these SOD1 constructs to develop a virus expressing either wild type SOD1 or the SOD1 mutant G93R and found a similar protective effect against serum withdrawal following infection with an HSV vector expressing wild-type SOD1 which offers a potential tool for neuroprotective gene delivery in vivo.


Assuntos
Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Apoptose/fisiologia , Sobrevivência Celular/fisiologia , Neurônios/fisiologia , Fármacos Neuroprotetores/metabolismo , Superóxido Dismutase/metabolismo , Animais , Linhagem Celular , Meios de Cultura Livres de Soro , Inibidores Enzimáticos/metabolismo , Vetores Genéticos , Humanos , Marcação In Situ das Extremidades Cortadas , Interferon gama/metabolismo , Mutagênese Sítio-Dirigida , Neurônios/citologia , Estaurosporina/metabolismo , Superóxido Dismutase/genética
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