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1.
J Acquir Immune Defic Syndr ; 95(4): 313-317, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38412045

RESUMEN

BACKGROUND: HIV testing is a critical step to accessing antiretroviral therapy (ART) because early diagnosis can facilitate earlier initiation of ART. This study presents aggregated data of individuals who self-reported being HIV-positive but subsequently tested HIV-negative during nationally representative Population-Based HIV Impact Assessment surveys conducted in 11 countries from 2015 to 2018. METHOD: Survey participants aged 15 years or older were interviewed by trained personnel using a standard questionnaire to determine HIV testing history and self-reported HIV status. Home-based HIV testing and counseling using rapid diagnostic tests with return of results were performed by survey staff according to the respective national HIV testing services algorithms on venous blood samples. Laboratory-based confirmatory HIV testing for all participants identified as HIV-positives and self-reported positives, irrespective of HIV testing results, was conducted and included Geenius HIV-1/2 and DNA polymerase chain reaction if Geenius was negative or indeterminate. RESULTS: Of the 16,630 participants who self-reported as HIV-positive, 16,432 (98.6%) were confirmed as HIV-positive and 198 (1.4%) were HIV-negative by subsequent laboratory-based testing. Participants who self-reported as HIV-positive but tested HIV-negative were significantly younger than 30 years, less likely to have received ART, and less likely to have received a CD4 test compared with participants who self-reported as HIV-positive with laboratory-confirmed infection. CONCLUSIONS: A small proportion of self-reported HIV-positive individuals could not be confirmed as positive, which could be due to initial misdiagnosis, deliberate wrong self-report, or misunderstanding of the questionnaire. As universal ART access is expanding, it is increasingly important to ensure quality of HIV testing and confirmation of HIV diagnosis before ART initiation.


Asunto(s)
Infecciones por VIH , Humanos , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Autoinforme , Encuestas y Cuestionarios , Errores Diagnósticos , África del Sur del Sahara/epidemiología
2.
Emerg Infect Dis ; 29(11): 2325-2334, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37877591

RESUMEN

Identifying persons who have newly acquired HIV infections is critical for characterizing the HIV epidemic direction. We analyzed pooled data from nationally representative Population-Based HIV Impact Assessment surveys conducted across 14 countries in Africa for recent infection risk factors. We included adults 15-49 years of age who had sex during the previous year and used a recent infection testing algorithm to distinguish recent from long-term infections. We collected risk factor information via participant interviews and assessed correlates of recent infection using multinomial logistic regression, incorporating each survey's complex sampling design. Compared with HIV-negative persons, persons with higher odds of recent HIV infection were women, were divorced/separated/widowed, had multiple recent sex partners, had a recent HIV-positive sex partner or one with unknown status, and lived in communities with higher HIV viremia prevalence. Prevention programs focusing on persons at higher risk for HIV and their sexual partners will contribute to reducing HIV incidence.


Asunto(s)
Infecciones por VIH , Humanos , Adulto , Femenino , Masculino , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , África/epidemiología , Factores de Riesgo , Parejas Sexuales , Recolección de Datos
3.
PLoS One ; 18(6): e0275560, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37363921

RESUMEN

BACKGROUND: We examined the epidemiology and transmission potential of HIV population viral load (VL) in 12 sub-Saharan African countries. METHODS: We analyzed data from Population-based HIV Impact Assessments (PHIAs), large national household-based surveys conducted between 2015 and 2019 in Cameroon, Cote d'Ivoire, Eswatini, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe. Blood-based biomarkers included HIV serology, recency of HIV infection, and VL. We estimated the number of people living with HIV (PLHIV) with suppressed viral load (<1,000 HIV-1 RNA copies/mL) and with unsuppressed viral load (viremic), the prevalence of unsuppressed HIV (population viremia), sex-specific HIV transmission ratios (number female incident HIV-1 infections/number unsuppressed male PLHIV per 100 persons-years [PY] and vice versa) and examined correlations between a variety of VL metrics and incident HIV. Country sample sizes ranged from 10,016 (Eswatini) to 30,637 (Rwanda); estimates were weighted and restricted to participants 15 years and older. RESULTS: The proportion of female PLHIV with viral suppression was higher than that among males in all countries, however, the number of unsuppressed females outnumbered that of unsuppressed males in all countries due to higher overall female HIV prevalence, with ratios ranging from 1.08 to 2.10 (median: 1.43). The spatial distribution of HIV seroprevalence, viremia prevalence, and number of unsuppressed adults often differed substantially within the same countries. The 1% and 5% of PLHIV with the highest VL on average accounted for 34% and 66%, respectively, of countries' total VL. HIV transmission ratios varied widely across countries and were higher for male-to-female (range: 2.3-28.3/100 PY) than for female-to-male transmission (range: 1.5-10.6/100 PY). In all countries mean log10 VL among unsuppressed males was higher than that among females. Correlations between VL measures and incident HIV varied, were weaker for VL metrics among females compared to males and were strongest for the number of unsuppressed PLHIV per 100 HIV-negative adults (R2 = 0.92). CONCLUSIONS: Despite higher proportions of viral suppression, female unsuppressed PLHIV outnumbered males in all countries examined. Unsuppressed male PLHIV have consistently higher VL and a higher risk of transmitting HIV than females. Just 5% of PLHIV account for almost two-thirds of countries' total VL. Population-level VL metrics help monitor the epidemic and highlight key programmatic gaps in these African countries.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Adulto , Humanos , Masculino , Femenino , Infecciones por VIH/tratamiento farmacológico , Viremia/tratamiento farmacológico , Carga Viral , Estudios Seroepidemiológicos , Lesotho , Zimbabwe , Fármacos Anti-VIH/uso terapéutico
4.
PLOS Glob Public Health ; 2(2): e0000080, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36962254

RESUMEN

INTRODUCTION: Late diagnosis of HIV (LD) increases the risk of morbidity, mortality, and HIV transmission. We used nationally representative data from population-based HIV impact assessment (PHIA) surveys in Malawi, Zambia, and Zimbabwe (2015-2016) to characterize adults at risk of LD and to examine associations between LD and presumed HIV transmission to cohabiting sexual partners. METHODS: We estimated the prevalence of LD, defined as CD4 count <350 cells/µL, among adults newly diagnosed with HIV during the surveys and odds ratios for associated factors. We linked newly diagnosed adults (index cases) to their household sexual partners and calculated adjusted odds ratios for associations between LD of the index case, viral load of the index case, and duration of HIV exposure in the relationship, and the HIV status of the household sexual partner. RESULTS: Of 1,804 adults who were newly diagnosed with HIV in the surveys, 49% (882) were diagnosed late. LD was associated with male sex, older age, and almost five times the odds of having an HIV-positive household sexual partner (adjusted odds ratio [aOR], 4.65 [95% confidence interval: 2.56-8.45]). Longer duration of HIV exposure in a relationship and higher viral load of the index case were both independently associated with higher odds of having HIV-positive household sexual partners. Individuals with HIV exposure of more than 5 years had more than three times (aOR 3.42 [95% CI: 1.63-7.18]) higher odds of being HIV positive than those with less than 2 years HIV exposure. The odds of being HIV positive were increased in individuals who were in a relationship with an index case with a viral load of 400-3499 copies/mL (aOR 4.06 [95% CI 0.45-36.46]), 3,500-9,999 copies/mL (aOR 11.32 [95% CI: 4.08-31.39]), 10,000-49,999 copies/mL (aOR 17.07 [95% CI: 9.18-31.72]), and ≥50,000 copies/mL (aOR 28.41 [95% CI: 12.18-66.28]) compared to individuals who were in a relationship with an index case with a viral load of <400 copies/mL. CONCLUSIONS: LD remains a challenge in Southern Africa and is strongly associated with presumed HIV transmission to household sexual partners. Our study underscores the need for earlier HIV diagnosis, particularly among men and older adults, and the importance of index testing.

5.
PLoS One ; 16(9): e0257476, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34543306

RESUMEN

BACKGROUND: Ineffective linkage to care (LTC) is a known challenge for community HIV testing. To overcome this challenge, a robust linkage to care strategy was adopted by the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). The NAIIS linkage to care strategy was further adapted to improve Nigeria's programmatic efforts to achieve the 1st 90 as part of the Nigeria Antiretroviral Therapy (ART) Surge initiative, which also included targeted community testing. In this paper we provide an overview of the NAIIS LTC strategy and describe the impact of this strategy on both the NAIIS and the Surge initiatives. METHODS: The NAIIS collaborated with community-based organizations (CBOs) and deployed mobile health (mHealth) technology with real-time dashboards to manage and optimize community LTC for people living with HIV (PLHIV) diagnosed during the survey. In NAIIS, CBOs' role was to facilitate linkage of identified PLHIV in community to facility of their choice. For the ART Surge, we modified the NAIIS LTC strategy by empowering both CBOs and mobile community teams as responsible for not only active LTC but also for community testing, ART initiation, and retention in care. RESULTS: Of the 2,739 PLHIV 15 years and above identified in NAIIS, 1,975 (72.1%) were either unaware of their HIV-positive status (N = 1890) or were aware of their HIV-positive status but not receiving treatment (N = 85). Of these, 1,342 (67.9%) were linked to care, of which 952 (70.9%) were initiated on ART. Among 1,890 newly diagnosed PLHIV, 1,278 (67.6%) were linked to care, 33.7% self-linked and 66.3% were linked by CBOs. Among 85 known PLHIV not on treatment, 64 (75.3%) were linked; 32.8% self-linked and 67.2% were linked by a CBO. In the ART Surge, LTC and treatment initiation rates were 98% and 100%, respectively. Three-month retention for monthly treatment initiation cohorts improved from 76% to 90% over 6 months. CONCLUSIONS: Active LTC strategies by local CBOs and mobile community teams improved LTC and ART initiation in the ART Surge initiative. The use of mHealth technology resulted in timely and accurate documentation of results in NAIIS. By deploying mHealth in addition to active LTC, CBOs and mobile community teams could effectively scale up ART with real-time documentation of client-level outcomes.


Asunto(s)
Atención a la Salud/métodos , Infecciones por VIH/psicología , Telemedicina , Adolescente , Adulto , Antirretrovirales/uso terapéutico , Estudios Transversales , Atención a la Salud/organización & administración , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Nigeria , Autoinforme , Encuestas y Cuestionarios , Adulto Joven
6.
J Acquir Immune Defic Syndr ; 87(Suppl 1): S73-S80, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34166315

RESUMEN

BACKGROUND: HIV-1 incidence calculation currently includes recency classification by HIV-1 incidence assay and unsuppressed viral load (VL ≥ 1000 copies/mL) in a recent infection testing algorithm (RITA). However, persons with recent classification not virally suppressed and taking antiretroviral (ARV) medication may be misclassified. SETTING: We used data from 13 African household surveys to describe the impact of an ARV-adjusted RITA on HIV-1 incidence estimates. METHODS: HIV-seropositive samples were tested for recency using the HIV-1 Limiting Antigen (LAg)-Avidity enzyme immunoassay, HIV-1 viral load, ARVs used in each country, and ARV drug resistance. LAg-recent result was defined as normalized optical density values ≤1.5. We compared HIV-1 incidence estimates using 2 RITA: RITA1: LAg-recent + VL ≥ 1000 copies/mL and RITA2: RITA1 + undetectable ARV. We explored RITA2 with self-reported ARV use and with clinical history. RESULTS: Overall, 357 adult HIV-positive participants were classified as having recent infection with RITA1. RITA2 reclassified 55 (15.4%) persons with detectable ARV as having long-term infection. Those with detectable ARV were significantly more likely to be aware of their HIV-positive status (84% vs. 10%) and had higher levels of drug resistance (74% vs. 26%) than those without detectable ARV. RITA2 incidence was lower than RITA1 incidence (range, 0%-30% decrease), resulting in decreased estimated new infections from 390,000 to 341,000 across the 13 countries. Incidence estimates were similar using detectable or self-reported ARV (R2 > 0.995). CONCLUSIONS: Including ARV in RITA2 improved the accuracy of HIV-1 incidence estimates by removing participants with likely long-term HIV infection.


Asunto(s)
Algoritmos , Monitoreo Epidemiológico , Infecciones por VIH/diagnóstico , VIH-1 , Adolescente , Adulto , Fármacos Anti-VIH/uso terapéutico , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Adulto Joven
7.
J Acquir Immune Defic Syndr ; 87(Suppl 1): S67-S72, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34166314

RESUMEN

BACKGROUND: In the population-based HIV impact assessment surveys, early infant diagnosis (EID) was provided to infants <18 months without a prior diagnosis. For the Namibia population-based HIV impact assessment (NAMPHIA), the GeneXpert platform was assessed for the feasibility of near POC EID testing compared with the standard Roche COBAS AmpliPrep/COBAS TaqMan (CAP/CTM) platform. Quality assurance measures and turnaround time were compared to improve EID results reporting. METHODS: NAMPHIA participants were screened for HIV exposure using Determine HIV-1/2 rapid test; samples reactive on Determine received EID testing on the GeneXpert instrument and Xpert HIV-1 Qual assay using whole blood. Results were confirmed at the Namibia Institute of Pathology using dried blood spots on the Roche CAP/CTM platform per national guidelines. RESULTS: Of the 762 screened infants, 61 (8.0%) were Determine-reactive and considered HIV-exposed. Of the 61 exposed infants, 2 were found to be HIV-infected whereas 59 were negative on both GeneXpert and Roche platforms, achieving 100% concordance. Average turnaround time was 3.4 days for the Xpert HIV-1 Qual assay, and average time from collection to testing was 1.0 days for GeneXpert compared with 10.7 days for Roche. No samples failed using GeneXpert whereas 1 sample failed using Roche and was repeated. CONCLUSION: Quality POC EID testing is feasible in a national survey through extensive training and external quality assurance measures. The use of decentralized POC EID for national testing would provide rapid diagnosis and improve TATs which may prevent loss to follow-up, ensure linkage to care, and improve clinical outcomes for infants.


Asunto(s)
Monitoreo Epidemiológico , Infecciones por VIH/diagnóstico , Prueba de VIH/métodos , VIH-1 , Encuestas Epidemiológicas , Pruebas en el Punto de Atención , Países en Desarrollo , Femenino , Humanos , Lactante , Recién Nacido , Masculino
8.
J Acquir Immune Defic Syndr ; 87(Suppl 1): S81-S88, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-33560041

RESUMEN

BACKGROUND: HIV population viral load (PVL) can reflect antiretroviral therapy program effectiveness and transmission potential in a community. Using nationally representative data from household surveys conducted in Zimbabwe, Malawi, and Zambia in 2015-16, we examined the association between various VL measures and the probability of at least one recent HIV-1 infection in the community. METHODS: We used limiting-antigen avidity enzyme immunoassay, viral load suppression (VLS) (HIV RNA <1000 copies/mL), and antiretrovirals in the blood to identify recent HIV-1 cases. RESULTS: Among 1510 enumeration areas (EAs) across the 3 surveys, 52,036 adults aged 15-59 years resided in 1363 (90.3%) EAs with at least one HIV-positive adult consenting to interview and blood draw and whose VL was tested. Mean HIV prevalence across these EAs was 13.1% [95% confidence intervals (CI) 12.7 to 13.5]. Mean VLS prevalence across these EAs was 58.7% (95% CI: 57.3 to 60.0). In multivariable analysis, PVL was associated with a recent HIV-1 case in that EA (adjusted odds ratio: 1.4, 95% CI: 1.2 to 1.6, P = 0.001). VLS prevalence was inversely correlated with recent infections (adjusted odds ratio: 0.3, 95% CI: 0.1 to 0.6, P = 0.004). The 90-90-90 indicators, namely, the prevalence of HIV diagnosis, antiretroviral therapy coverage, and VLS at the EA level, were inversely correlated with HIV recency at the EA level. CONCLUSIONS: We found a strong association between PVL and VLS prevalence and recent HIV-1 infection at the EA level across 3 southern African countries with generalized HIV epidemics. These results suggest that population-based measures of VLS in communities may serve as a proxy for epidemic control.


Asunto(s)
Infecciones por VIH/epidemiología , VIH-1 , Carga Viral , Viremia , Monitoreo Epidemiológico , Infecciones por VIH/virología , Encuestas Epidemiológicas , Humanos , Malaui/epidemiología , Zambia/epidemiología , Zimbabwe/epidemiología
9.
J Int AIDS Soc ; 23(11): e25631, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33225559

RESUMEN

INTRODUCTION: The global target for 2020 is that ≥90% of people living with HIV (PLHIV) receiving antiretroviral therapy (ART) will achieve viral load suppression (VLS). We examined VLS and its determinants among adults receiving ART for at least four months. METHODS: We analysed data from the population-based HIV impact assessment (PHIA) surveys in Eswatini, Lesotho, Malawi, Zambia and Zimbabwe (2015 to 2017). PHIA surveys are nationally representative, cross-sectional household surveys. Data collection included structured interviews, home-based HIV testing and laboratory testing. Blood samples from PLHIV were analysed for HIV RNA, CD4 counts and recent exposure to antiretroviral drugs (ARVs). We calculated representative estimates for the prevalence of VLS (viral load <1000 copies/mL), nonsuppressed viral load (NVL; viral load ≥1000 copies/mL), virologic failure (VF; ARVs present and viral load ≥1000 copies/mL), interrupted ART (ARVs absent and viral load ≥1000 copies/mL) and rates of switching to second-line ART (protease inhibitors present) among PLHIV aged 15 to 59 years who participated in the PHIA surveys in Eswatini, Lesotho, Malawi, Zambia and Zimbabwe, initiated ART at least four months before the survey and were receiving ART at the time of the survey (according to self-report or ARV testing). We calculated odds ratios and incidence rate ratios for factors associated with NVL, VF, interrupted ART, and switching to second-line ART. RESULTS: We included 9200 adults receiving ART of whom 88.8% had VLS and 11.2% had NVL including 8.2% who experienced VF and 3.0% who interrupted ART. Younger age, male sex, less education, suboptimal adherence, receiving nevirapine, HIV non-disclosure, never having married and residing in Zimbabwe, Lesotho or Zambia were associated with higher odds of NVL. Among people with NVL, marriage, female sex, shorter ART duration, higher CD4 count and alcohol use were associated with lower odds for VF and higher odds for interrupted ART. Many people with VF (44.8%) had CD4 counts <200 cells/µL, but few (0.31% per year) switched to second-line ART. CONCLUSIONS: Countries are approaching global VLS targets for adults. Treatment support, in particular for younger adults, and people with higher CD4 counts, and switching of people to protease inhibitor- or integrase inhibitor-based regimens may further reduce NVL prevalence.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH/fisiología , Adolescente , Adulto , Recuento de Linfocito CD4 , Estudios Transversales , Esuatini/epidemiología , Femenino , Infecciones por VIH/epidemiología , Humanos , Incidencia , Lesotho/epidemiología , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Nevirapina/uso terapéutico , Prevalencia , Encuestas y Cuestionarios , Carga Viral , Adulto Joven , Zambia/epidemiología , Zimbabwe/epidemiología
10.
PLoS One ; 15(7): e0236501, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32706823

RESUMEN

OBJECTIVES: The main objectives of the study are to estimate HIV prevalence, active syphilis prevalence, and correlates of co-infection with HIV in Zambia, among recently sexually active individuals aged 15 to 59 years old. METHODS: We used data from the 2016 Zambia Population-based HIV Impact Assessment (ZAMPHIA), a national household survey that included biomarker testing for HIV and syphilis. Chembio DPP® Syphilis Screen and Confirm Assay was used to distinguish between active and older syphilis infections. This is the first time Chembio DPP® has been used in a national survey. Log-binominal modelling was utilized to understand the risk of acquiring HIV/active syphilis co-infection using select socio-demographic and sexual behavior variables. Multivariable analysis compared those with co-infection and those with no infection. All reported results account for the complex survey design and are weighted. RESULTS: A total of 19,114 individuals aged 15-59 years responded to the individual interview and had a valid syphilis and/or HIV test. The prevalence for those sexually active in the 12 months preceding ZAMPHIA 2016 was 3.5% and 13% for active syphilis and HIV, respectively. The prevalence of HIV/active syphilis co-infection was 1.5%. Factors associated with higher prevalence of co-infection versus no infection among females included, but were not limited to, those living in urban areas (adjusted prevalence ratio (aPR) = 3.0, 95% CI = 1.8, 4.8), those had sexual intercourse before age 15 years (aPR = 1.8, 95% CI = 1.1, 2.9), and those who had two or more sexual partners in the 12 months preceding the survey (aPR = 2.7, 95% CI = 1.6, 4.7). CONCLUSION: These findings show high prevalence for both mono-infection with HIV and syphilis, as well as co-infection with HIV/active syphilis in Zambia. There is a need for better screening and partner services, particularly among those engaging in high-risk sexual behaviors (e.g., engaging in transactional sex).


Asunto(s)
Coinfección/epidemiología , Infecciones por VIH/epidemiología , Sífilis/epidemiología , Adolescente , Adulto , Estudios Transversales , Femenino , VIH-1 , Conductas de Riesgo para la Salud , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Encuestas y Cuestionarios , Sexo Inseguro , Adulto Joven , Zambia/epidemiología
11.
MMWR Morb Mortal Wkly Rep ; 67(1): 29-32, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29329280

RESUMEN

In 2016, an estimated 1.5 million females aged 15-24 years were living with human immunodeficiency virus (HIV) infection in Eastern and Southern Africa, where the prevalence of HIV infection among adolescent girls and young women (3.4%) is more than double that for males in the same age range (1.6%) (1). Progress was assessed toward the Joint United Nations Programme on HIV/AIDS (UNAIDS) 2020 targets for adolescent girls and young women in sub-Saharan Africa (90% of those with HIV infection aware of their status, 90% of HIV-infected persons aware of their status on antiretroviral treatment [ART], and 90% of those on treatment virally suppressed [HIV viral load <1,000 HIV RNA copies/mL]) (2) using data from recent Population-based HIV Impact Assessment (PHIA) surveys in seven countries. The national prevalence of HIV infection in adolescent girls and young women aged 15-24 years, the percentage who were aware of their status, and among those persons who were aware, the percentage who had achieved viral suppression were calculated. The target for viral suppression among all persons with HIV infection is 73% (the product of 90% x 90% x 90%). Among all seven countries, the prevalence of HIV infection among adolescent girls and young women was 3.6%; among those in this group, 46.3% reported being aware of their HIV-positive status, and 45.0% were virally suppressed. Sustained efforts by national HIV and public health programs to diagnose HIV infection in adolescent girls and young women as early as possible to ensure rapid initiation of ART should help achieve epidemic control among adolescent girls and young women.


Asunto(s)
Epidemias/prevención & control , Infecciones por VIH/prevención & control , Adolescente , África/epidemiología , Fármacos Anti-VIH/uso terapéutico , Femenino , Infecciones por VIH/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Prevalencia , Evaluación de Programas y Proyectos de Salud , Carga Viral/estadística & datos numéricos , Adulto Joven
12.
J Recept Signal Transduct Res ; 35(6): 516-22, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25224408

RESUMEN

Insulin, when co-applied with GABA, can cause an inhibition of the induced current at GABAA receptors. This study investigated that inhibitory effect of insulin at a variety of receptor isoforms, concentrating on α1, α2 and α4 containing receptors. Various isoforms were expressed in Xenopus oocytes and currents determined using two-electrode voltage clamp. Submaximal GABA currents at all isoforms studied were inhibited by nanomolar concentrations of insulin. At α2 and α4 containing forms, insulin could inhibit maximal GABA currents. The ability to inhibit maximal currents, and the general potency and effects at submaximal currents paralleled the number of potential MAPK sites on the α subunits. The differences in insulin inhibition of GABA currents at different α containing GABAA receptors could be important in autocrine and paracrine control of hormone secretion in the pancreas, and in control of reward and food intake circuits of the brain.


Asunto(s)
Moduladores del GABA/farmacología , Insulina/farmacología , Oocitos/metabolismo , Receptores de GABA-A/metabolismo , Xenopus laevis/metabolismo , Secuencia de Aminoácidos , Animales , Electrofisiología , Hipoglucemiantes/farmacología , Potenciales de la Membrana , Datos de Secuencia Molecular , Oocitos/citología , Oocitos/efectos de los fármacos , Fosforilación/efectos de los fármacos , Ratas , Homología de Secuencia de Aminoácido , Xenopus laevis/crecimiento & desarrollo , Ácido gamma-Aminobutírico/metabolismo
14.
Neurochem Int ; 58(7): 794-803, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21397651

RESUMEN

Pregnane derived steroids have agonistic and antagonistic actions at GABA(A) receptors. Putative binding sites for agonistic neurosteroids are located within the transmembrane (TM) regions. A mutation within the rat α(1) TM3 region, S299C, caused the expressed receptors to have unusual and extreme sensitivity to agonistic neurosteroids. For mutant α1S299C receptors, with wild type ß and γ subunits, expressed in Xenopus oocytes, steroids activated the GABA(A) receptors in the absence of GABA. Maximal steroid induced currents were about half of maximal GABA currents. The steroid activation was biphasic with EC(50)'s much lower than wild type, in subnanomolar and nanomolar concentrations, while the wild type had only one activation peak with near micromolar EC(50). These currents could be blocked by both picrotoxin and an antagonist neurosteroid. The steroids did not seem to potentiate significantly submaximal GABA currents. The α1S299C mutation did not affect responses to the extracellularly acting partial agonist piperidine-4-sulfate. Substituted cysteine experiments indicate that this mutant can be modified by pCMBS(-) when the sulfhydryl reagent is added with the higher steroid concentration for activation but not the lower steroid concentration. The pCMBS(-) will also immediately block the high concentration steroid current. Taken together the data suggest that α1S299 is important in at least the in transduction of the steroid binding to the rest of the receptor.


Asunto(s)
Mutación , Neurotransmisores/metabolismo , Receptores de GABA-A/genética , Animales , Relación Dosis-Respuesta a Droga , Pregnanolona/farmacología , Xenopus laevis
15.
Fertil Steril ; 93(6): 2088-90, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20116786

RESUMEN

A retrospective study was performed to determine whether the timing of embryo transfer catheter removal effects pregnancy rates in fresh, day 3 IVF cycles. Two hundred eighteen patients were evaluated, and no difference was noted between delayed versus immediate catheter removal techniques.


Asunto(s)
Cateterismo/métodos , Remoción de Dispositivos , Transferencia de Embrión/instrumentación , Recuperación del Oocito/métodos , Adulto , Cateterismo/efectos adversos , Remoción de Dispositivos/efectos adversos , Remoción de Dispositivos/métodos , Transferencia de Embrión/métodos , Femenino , Fertilización In Vitro/métodos , Humanos , Embarazo , Resultado del Embarazo , Estudios Retrospectivos , Factores de Tiempo
16.
Fertil Steril ; 94(2): 678-83, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19515366

RESUMEN

OBJECTIVE: To determine the effect of intravaginal micronized P on pregnancy rates in clomiphene citrate and letrozole ovulation induction cycles in women with polycystic ovary syndrome (PCOS). DESIGN: Retrospective chart review. SETTING: University-based assisted reproductive technology program. PATIENTS: Women with PCOS who underwent ovulation induction with either clomiphene citrate (n = 90) or letrozole (n = 31) from January 2002 to December 2008. INTERVENTION(S): Clomiphene citrate (50-250 mg x 5 days) or letrozole (5 mg x 5 days) were used for ovulation induction. After either intercourse or IUI, patients received intravaginal micronized P (200 mg twice daily) according to prescribing physician preference. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate. RESULT(S): In clomiphene cycles, clinical pregnancies were documented in 15.3% of cycles (19 of 124) in the P group, compared with 12.1% (11 of 91) of the non-P group. In letrozole cycles, clinical pregnancies were documented in 21.1% of cycles (8 of 38) in the P group, compared with none (0 of 13) in the non-P group. CONCLUSION(S): Women with PCOS who used letrozole for ovulation induction had higher clinical pregnancy rates when using intravaginal P support. Luteal supplementation with P should be strongly considered in women with PCOS, especially in those using letrozole for ovulation induction.


Asunto(s)
Infertilidad Femenina/tratamiento farmacológico , Nitrilos/administración & dosificación , Inducción de la Ovulación/métodos , Síndrome del Ovario Poliquístico/complicaciones , Índice de Embarazo , Progesterona/administración & dosificación , Triazoles/administración & dosificación , Administración Intravaginal , Adulto , Inhibidores de la Aromatasa/administración & dosificación , Clomifeno/administración & dosificación , Femenino , Humanos , Infertilidad Femenina/complicaciones , Inseminación Artificial , Letrozol , Fase Luteínica/efectos de los fármacos , Embarazo , Progestinas/administración & dosificación , Estudios Retrospectivos , Adulto Joven
17.
J Assist Reprod Genet ; 26(6): 335-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19548079

RESUMEN

PURPOSE: To determine whether follicle curetting at the time of oocyte retrieval increases oocyte yield. METHODS: Retrospective review of all patients who underwent oocyte retrieval from July 1, 2003 to June 30, 2005. MAIN OUTCOME MEASURE: Number of oocytes retrieved. SECONDARY OUTCOME MEASURES: retrieval time, number of cryopreserved embryos, pregnancy rates, and incidence of ovarian hyperstimulation syndrome. RESULTS: There were no differences in patient demographics, antral follicle count, cycle stimulation characteristics, fertilization rates, embryo quantity or quality, embryo cryopreservation rates, clinical pregnancy rates, live birth rates, or ovarian hyperstimulation syndrome between the groups. Retrievals that utilized curetting took three minutes longer. Follicle curetting significantly increased the number of oocytes retrieved, 13.9 +/- 0.6 compared to 11.4 +/- 0.6 oocytes without curetting (P = 0.003). The quantity of mature oocytes was also increased with curetting (10.3 +/- 0.5 versus 8.4 +/- 0.5, P = 0.006). CONCLUSIONS: This study demonstrated that follicle curetting significantly increased oocyte yield. While it did not increase live birth rates, this increase in oocyte yield should lead to increased numbers of embryos for selection at transfer and increased embryos for cryopreservation.


Asunto(s)
Recuperación del Oocito/métodos , Oocitos , Folículo Ovárico , Adulto , Femenino , Fertilización In Vitro , Humanos , Masculino , Inducción de la Ovulación , Embarazo , Resultado del Embarazo
18.
Reprod Toxicol ; 26(2): 183-4, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18762242

RESUMEN

Prior to 2007, use of the insulin sensitizer metformin was widely advocated in patients with polycystic ovarian syndrome (PCOS) both to promote ovulation and decrease the incidence of PCOS-associated obstetrical complications. However, the gastrointestinal disturbances associated with metformin led many to discontinue its use. Rosiglitazone is an insulin sensitizer that, because of minimal associated gastrointestinal disturbance, was used as an alternative to metformin in PCOS patients. From 2003 to 2005, 8 women with PCOS unable to tolerate metformin used rosiglitazone for ovulation induction and during their first 12 weeks of gestation. All delivered healthy babies at term, without obstetric complications or congenital anomalies. However, given recent evidence that disputes the reproductive benefits of insulin sensitization for PCOS and that raises safety concerns of rosiglitazone, we are no longer using it for PCOS treatment.


Asunto(s)
Anovulación/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Inducción de la Ovulación/métodos , Ovulación/efectos de los fármacos , Síndrome del Ovario Poliquístico/fisiopatología , Tiazolidinedionas/uso terapéutico , Adulto , Anovulación/etiología , Femenino , Humanos , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Recién Nacido , Síndrome del Ovario Poliquístico/complicaciones , Embarazo , Resultado del Embarazo , Primer Trimestre del Embarazo , Rosiglitazona , Tiazolidinedionas/administración & dosificación , Tiazolidinedionas/efectos adversos
19.
Neurosci Lett ; 443(1): 27-31, 2008 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-18672028

RESUMEN

In the CNS, GABA and insulin seem to contribute to similar processes, including neuronal survival; learning and reward; and energy balance and food intake. It is likely then that insulin and GABA may interact, perhaps at the GABA(A) receptor. One such interaction has already been described [Q. Wan, Z.G. Xiong, H.Y. Man, C.A. Ackerley, J. Braunton, W.Y. Lu, L.E. Becker, J.F. MacDonald, Y.T. Wang, Recruitment of functional GABA(A) receptors to postsynaptic domains by insulin, Nature 388 (1997) 686-690]; in it a micromolar concentration of insulin causes the insertion of GABA(A) receptors into the cell membrane, increasing GABA current. I have discovered another effect of insulin on GABA(A) currents. Using a receptor isoform, alpha(1)beta(2)gamma(2s) that is the likely main neuronal GABA(A) isoform expressed recombinantly in Xenopus oocytes, insulin inhibits GABA-induced current when applied simultaneously with low concentrations of GABA. Insulin will significantly inhibit currents induced by EC(30-50) concentrations of GABA by about 38%. Insulin is potent in this effect; IC(50) of insulin was found to be about 4.3 x 10(-10) M. The insulin effect on the GABA dose responses looked like that of an antagonist similar to bicuculline or beta-carbolines. However, an effect of phosphorylation on the GABA(A) receptor from the insulin receptor signal transduction pathway cannot yet be dismissed.


Asunto(s)
Hipoglucemiantes/farmacología , Insulina/farmacología , Potenciales de la Membrana/efectos de los fármacos , Receptores de GABA-A/fisiología , Animales , Bicuculina/farmacología , Carbolinas/farmacología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Antagonistas del GABA/farmacología , Concentración 50 Inhibidora , Potenciales de la Membrana/fisiología , Microinyecciones , Oocitos , Técnicas de Placa-Clamp , Ratas , Xenopus laevis , Ácido gamma-Aminobutírico/farmacología
20.
Fertil Steril ; 90(5): 2006.e17-9, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18635167

RESUMEN

OBJECTIVE: To report on a patient with virilization during pregnancy who experienced delayed lactation secondary to elevated maternal androgens. DESIGN: Case report and review of the literature. SETTING: University hospital. PATIENT(S): A 32-year-old pregnant woman presented with virilization at 32 weeks' gestation. INTERVENTION(S): Laboratory evaluation, ultrasound examination, magnetic resonance imaging, cesarean section for fetal indication, nipple stimulation to facilitate lactation. MAIN OUTCOME MEASURE(S): Case report. RESULT(S): Postpartum normalization of serum T levels and patient ability to breastfeed exclusively after delayed initiation of lactation. CONCLUSION(S): Maternal virilization during pregnancy is rare and is often due to androgen-secreting tumors that are benign. Therefore, careful evaluation of these patients is important to avoid inadvertent oophorectomy.


Asunto(s)
Lactancia , Luteoma/complicaciones , Neoplasias Ováricas/complicaciones , Complicaciones Neoplásicas del Embarazo , Virilismo/etiología , Adulto , Andrógenos/sangre , Lactancia Materna , Cesárea , Femenino , Edad Gestacional , Humanos , Nacimiento Vivo , Luteoma/patología , Luteoma/fisiopatología , Imagen por Resonancia Magnética , Neoplasias Ováricas/patología , Neoplasias Ováricas/fisiopatología , Embarazo , Regulación hacia Arriba , Virilismo/patología , Virilismo/fisiopatología
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