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1.
Fertil Steril ; 121(2): 291-298, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37952915

RESUMO

OBJECTIVE: To determine whether body mass index (BMI) was associated with live birth in patients undergoing transfer of frozen-thawed preimplantation genetic testing for aneuploidy (PGT-A) embryos. DESIGN: Retrospective cohort study of cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. SUBJECTS: All autologous and donor recipient PGT-A-tested cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2017. INTERVENTION(S): Body mass index. MAIN OUTCOME MEASURE(S): The primary outcome measure was the live birth rate, and the secondary outcome measures were the clinical pregnancy and biochemical pregnancy rates. Multivariable generalized additive mixed models and log-binomial models were used to model the relationship between BMI and outcome measures. RESULT(S): A total of 77,018 PGT-A cycles from 55,888 patients were analyzed. Of these cycles, 70,752 were autologous, and 6,266 were donor recipient. In autologous cycles, a statistically significant and clear nonlinear relationship was observed between the BMI and live birth rates, with the highest birth rates observed for the BMI range of 23-24.99 kg/m2. When using 23-24.99 kg/m2 as the referent, other BMI ranges demonstrated a lower probability of live birth and clinical pregnancy that continued to decrease as the BMI moved further from the reference value. Patients with a BMI of <18.5 kg/m2 had a 11% lower probability of live birth, whereas those with a BMI of ≥40 kg/m2 had a 27% lower probability than the referent. CONCLUSION(S): A normal-weight BMI range of 23-24.99 kg/m2 was associated with the highest probability of clinical pregnancy and live birth after a frozen-thawed PGT-A-tested blastocyst transfer in both autologous and donor recipient cycles. A BMI outside the range of 23-24.99 kg/m2 is likely associated with a malfunction in the implantation process, which is presumed to be related to a uterine factor and not an oocyte factor, as both autologous and donor recipient cycle outcomes were associated similarly with the BMI of the intended parent.


Assuntos
Coeficiente de Natalidade , Transferência Embrionária , Gravidez , Feminino , Humanos , Índice de Massa Corporal , Estudos Retrospectivos , Transferência Embrionária/efeitos adversos , Técnicas de Reprodução Assistida , Taxa de Gravidez , Testes Genéticos , Nascido Vivo , Aneuploidia , Avaliação de Resultados em Cuidados de Saúde , Fertilização in vitro/efeitos adversos
2.
Obstet Gynecol ; 143(1): 92-100, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37944144

RESUMO

OBJECTIVE: To compare obstetric and neonatal outcomes after single embryo transfer (SET) compared with multiple embryo transfer (MET) from frozen-thawed transfer cycles of embryos that underwent preimplantation genetic testing for aneuploidies (PGT-A). METHODS: We conducted a retrospective cohort study from the SART CORS (Society for Assisted Reproductive Technology Clinic Outcome Reporting System) national database. Clinical and demographic data were obtained from the SART CORS database for all autologous and donor egg frozen-thawed transfer cycles of embryos that underwent PGT-A between 2014 and 2016, after excluding cycles that used frozen oocytes, fresh embryo transfer, and transfers of embryos from more than one stimulation cycle. Multivariable linear and log-binomial regression models were used to estimate the relative and absolute difference in live-birth rate, multiple pregnancy rate, gestational age at delivery, and birth weight between SET compared with MET. RESULTS: In total, 15,638 autologous egg transfer cycles and 944 donor egg transfer cycles were analyzed. Although the live-birth rate was higher with MET compared with SET in the autologous oocyte cycles (64.7% vs 53.2%, relative risk [RR] 1.24, 95% CI, 1.20-1.28), the multiple pregnancy rate was markedly greater (46.2% vs 1.4%, RR 32.56, 95% CI, 26.55-39.92). Donor oocyte cycles showed similar trends with an increased live-birth rate (62.0% vs 49.7%, RR 1.26, 95% CI, 1.11-1.46) and multiple pregnancy rate (54.0% vs 0.8%) seen with MET compared with SET. Preterm delivery rates and rates of low birth weight were significantly higher in MET compared with SET in both autologous and donor oocyte cycles and were also higher in the subanalysis of singleton deliveries that resulted from MET compared with SET. CONCLUSION: Despite some improvement in live-birth rate, nearly half of the pregnancies that resulted from MET of embryos that underwent PGT-A were multiples. Compared with SET, MET is associated with significantly higher rates of neonatal morbidity, including preterm delivery and low birth weight. The transfer of more than one embryo that underwent PGT-A should continue to be strongly discouraged, and patients should be counseled on the significant potential for adverse outcomes.


Assuntos
Fertilização in vitro , Nascimento Prematuro , Gravidez , Recém-Nascido , Feminino , Humanos , Fertilização in vitro/efeitos adversos , Nascimento Prematuro/etiologia , Estudos Retrospectivos , Nascido Vivo , Taxa de Gravidez , Testes Genéticos
4.
Fertil Steril ; 120(3 Pt 1): 521-527, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36849035

RESUMO

Tremendous advances in genetics have transformed the field of reproductive endocrinology and infertility over the last few decades. One of the most prominent advances is preimplantation genetic testing (PGT), which allows for the screening of embryos obtained during in vitro fertilization before transfer. Moreover, PGT can be performed for aneuploidy screening, detection of monogenic disorders, or exclusion of structural rearrangements. Refinement of biopsy techniques, such as obtaining samples at the blastocyst rather than the cleavage stage, has helped optimize results from PGT, and technological advances, including next-generation sequencing, have made PGT more efficient and accurate. The continued evolution of the approach to PGT has the potential to further enhance the accuracy of results, expand the application to other conditions, and increase access by reducing cost and improving efficiency.


Assuntos
Infertilidade , Diagnóstico Pré-Implantação , Gravidez , Feminino , Humanos , Diagnóstico Pré-Implantação/métodos , Infertilidade/diagnóstico , Infertilidade/genética , Infertilidade/terapia , Testes Genéticos/métodos , Aneuploidia , Fertilização in vitro , Blastocisto/patologia
5.
Fertil Steril ; 117(3): 548-559, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35058041

RESUMO

OBJECTIVE: To measure the consequences of nonadherence with the 2013 American Society for Reproductive Medicine elective single embryo transfer (eSET) guidelines for favorable-prognosis patients. DESIGN: Retrospective cohort. SETTING: In vitro fertilization clinics. PATIENT(S): A total of 28,311 fresh autologous, 2,500 frozen-thawed autologous, and 3,534 fresh oocyte-donor in vitro fertilization cycles in 2014-2016 at Society for Assisted Reproductive Technology-reporting centers. INTERVENTION(S): Patients aged <35 years or using donors aged <35 years underwent first blastocyst transfer. MAIN OUTCOME MEASURE(S): Singleton birth rate, gestational age at delivery, and birth weight were compared between the eSET and non-eSET groups using the chi-square or Fisher's exact test or t-tests. RESULT(S): Among fresh transfers, 15,643 (55%) underwent eSET. Live births after non-eSETs were less likely singletons (38.0% vs. 96.5%; adjusted relative risk [aRR], 0.56) and more likely complicated by preterm delivery (55.0% vs. 20.1%; aRR, 2.39) and low birth weight (<2,500 g) (40.1% vs. 10.6%; aRR, 3.4) compared with those after eSET. Among frozen-thawed transfers, 1,439 (58%) underwent eSET. Live births after non-eSETs were less likely singletons (41.9% vs. 95.2%; aRR, 0.69; 95% confidence interval, 0.66-0.73) and more likely complicated by preterm delivery (56.4% vs. 19.5%; aRR, 2.6; 95% confidence interval, 2.2-3.1) and low birth weight (38.0% vs. 8.9%; aRR, 3.9) compared with those after eSET. Among fresh donor oocyte transfers, 1,946 (55%) underwent eSET. Live births after non-eSETs were less likely singletons (31.3% vs. 97.3%; aRR, 0.48) and more likely complicated by preterm delivery (61.1% vs. 25.7%; aRR, 2.09) and low birth weight (44.3% vs. 11.7%; aRR, 3.39) compared with those after eSET. CONCLUSION(S): Nonadherence with transfer guidelines was associated with dramatically increased multiple pregnancies, preterm births, and low birth weights.


Assuntos
Transferência Embrionária/normas , Fidelidade a Diretrizes/normas , Nascido Vivo/epidemiologia , Oócitos/fisiologia , Guias de Prática Clínica como Assunto/normas , Sociedades Médicas/normas , Adulto , Estudos de Coortes , Transferência Embrionária/métodos , Feminino , Humanos , Recém-Nascido , Doadores Vivos , Masculino , Gravidez , Prognóstico , Sistema de Registros , Técnicas de Reprodução Assistida/normas , Projetos de Pesquisa/normas , Estudos Retrospectivos , Transplante Autólogo/normas , Estados Unidos/epidemiologia , Adulto Jovem
6.
Syst Biol Reprod Med ; 67(2): 144-150, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33726574

RESUMO

The SARS-CoV-2 pandemic peak around March 2020 led to temporary closures of most fertility clinics. Many clinics reopened but required universal SARS-CoV-2 screening. However, the rate of positive results and the necessity for such testing is unknown. We report here on early results from asingle-center academic NewYork fertility practice utilizing universal SARS-CoV-2 screening. This mixed prospective retrospective cohort included 164 patients who underwent at least one SARS-CoV-2 screening test for fertility treatment between May and July2020. Patients completed 1 to 3 nasopharyngeal SARS-CoV-2 tests per cycle and remained symptom-free to continue fertility treatments. SARS-CoV-2 test results, past results, history of Covid-19 infection, and patient/cycle characteristics were recorded and tabulated through October2020. Outcomes included positive SARS-CoV-2 RNA tests, rate of prior Covid-19 infections, and clinical courses of patients testing positive. Patients underwent 263 cycles entailing 460 total SARS-CoV-2 screening tests. Fifteen patients reported astrong prior clinical history of Covid-19. Six patients experienced apositive SARS-CoV-2 test (2.3% of all cycles). Among 77 cycles (n = 58 patients) entailing one SARS-CoV-2 test, 2 cases (2.6%) were noted. Among 173 cycles (n = 121 patients) entailing two SARS-CoV-2 tests, 4 cycles (2.3%) were noted. Zero (0%) of 13 cycles (n = 13 patients) entailing 3 SARS-CoV-2 tests were positive. All patients were cleared to resume treatment within one month. Overall, anew asymptomatic infection was identified in 2 cycles (0.8%), while 4 of the 6 positive SARS-CoV-2 tests were among patients with aprior history of Covid-19. 3 of 4 also had adocumented prior positive RNA test. Our data suggest that universal SARS-CoV-2 screening among fertility patients is feasible, with an approximately 2% positive rate per cycle among the patients of this study. Most positive patients had aprior remote infection, but their infectiousness while being screened remains unclear.Abbreviations: REI: reproductive endocrinology and infertility; IUI: intrauterine insemination; IVF: in vitro fertilization; sono: sonography; cryo: cryopreservation; FET: frozen embryo transfer.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , Endocrinologia , Clínicas de Fertilização , Adulto , COVID-19/epidemiologia , Testes Diagnósticos de Rotina , Feminino , Humanos , Padrões de Prática Médica , SARS-CoV-2
7.
Arch Gynecol Obstet ; 303(6): 1617-1623, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33544203

RESUMO

PURPOSE: Women with cancer may desire fertility preservation (FP) prior to initiating cancer treatment, but undergoing FP may result in treatment delays. This study sought to determine whether such delays existed in our population and which factors were associated with patients' decision to proceed with FP. METHODS: This was a historical cohort study performed at Montefiore Medical Center's Institute for Reproductive Medicine and Health. Reproductive age women diagnosed with cancer and consulted for FP were included. The main outcome measure was the number of days between FP consultation and cancer treatment initiation. Factors associated with patients' decisions to proceed with FP were also analyzed. RESULTS: Thirty out of 51 women in our study underwent FP including embryo cryopreservation, oocyte cryopreservation, ovarian tissue cryopreservation (OTC), both oocyte and embryo cryopreservation, or GnRH agonist treatment. The majority of women who underwent FP chose embryo cryopreservation (36.7%), followed by oocyte cryopreservation (33.3%). Of the 20 patients with partners who underwent FP, 13 (65%) froze embryos. Only 4 of the 30 women who underwent FP had all, or a portion of their services, covered by insurance. The mean treatment delay was 18 days (p = 0.007), with a mean consultation to oncologic treatment gap of 23 ± 16.8 and 41.4 ± 25.9 days in the non-FP and FP groups, respectively. CONCLUSION: Women with cancer diagnosis who underwent FP prior to initiating cancer treatment experienced a statistically significant delay in initiating cancer treatment. However, the clinical significance of this finding is unknown since FP treatments have not been associated with increased recurrence or mortality.


Assuntos
Preservação da Fertilidade , Neoplasias , Estudos de Coortes , Criopreservação , Feminino , Humanos , Neoplasias/tratamento farmacológico , Recuperação de Oócitos , Oócitos
8.
J Assist Reprod Genet ; 37(12): 3033-3038, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33047187

RESUMO

PURPOSE: To evaluate the effect of controlled ovarian hyperstimulation length and total gonadotropin (GN) dose on recipient live birth rate (LBR) in fresh donor oocyte cycles. METHODS: Data was obtained from SART CORS on all fresh donor oocyte GnRH antagonist cycles (n = 1049) between 2014 and 2015 which resulted in a single embryo transferred. Donor and recipient demographic information and cycle characteristics were extracted. Binomial regression was used to estimate LBR with respect to days of stimulation (DOS) and total GN dose. Multivariate analysis was performed to evaluate these relationships after controlling for confounders. RESULTS: Overall LBR in fresh donor oocyte cycles was 57%. Average stimulation length was 14.3 ± 4.9 days, and total GN dose was 2464 ± 1062 IU. On univariate analysis, neither days of stimulation (p = 0.5) nor total GN dose (p = 0.57) was independently correlated with LBR. However, in prolonged stimulations (> 15 days) with high total GN dose (> 3000 IU), as both the cycle length and total GN dose increased, LBR significantly decreased from 63.81 to 48.15% (p = 0.02) and from 67.61 to 48.15% (p = 0.01), respectively. Multivariate analysis showed no significant effect of either DOS or total GN dose on LBR. CONCLUSIONS: LBR is significantly decreased in fresh donor oocyte cycles when cycles are prolonged with high total GN dose. However, after controlling for confounders neither DOS nor total GN dose significantly affects LBR.


Assuntos
Coeficiente de Natalidade , Gonadotropina Coriônica/administração & dosagem , Transferência Embrionária/métodos , Fertilização in vitro/métodos , Nascido Vivo/epidemiologia , Indução da Ovulação/métodos , Injeções de Esperma Intracitoplásmicas/métodos , Adulto , Feminino , Humanos , Masculino , New York/epidemiologia , Gravidez , Taxa de Gravidez , Doadores de Tecidos
9.
Fertil Steril ; 114(6): 1225-1231, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33012553

RESUMO

OBJECTIVE: To study the impact of both controlled ovarian hyperstimulation (COH) length and total gonadotropin (GN) dose individually and in concert on live birth rates (LBR) in both fresh and freeze-all in vitro fertilization embryo transfer (IVF-ET) cycles. DESIGN: Historical cohort study. SETTING: Not applicable. PATIENT(S): The U.S. national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2015 was used to identify patients undergoing autologous GN stimulation IVF cycles with the use of GnRH antagonist-based suppression protocols where a single embryo transfer was performed as part of a fresh IVF-ET cycle (fresh, n = 14,866) or the first frozen embryo transfer after a freeze-all cycle (frozen, n = 2,964), and not including preimplantation genetic testing cycles. The patients' demographic and cycle characteristics, duration of COH, total GN dose, and pregnancy outcomes were extracted. Binomial regression models estimated trend and relative risk of live birth with respect to days of stimulation and total GN dose singularly, and after adjustment for a priori confounders including age, parity, body mass index, diagnosis, and maximum follicle-stimulating hormone in both fresh and frozen embryo transfer cycles. Both days of stimulation and total GN dose were then added to the multivariate model to show whether they were independently associated with LBR. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Live birth rate. RESULTS: In both fresh and frozen cycles, length of COH was significantly associated with total GN dose. On univariate analysis, LBR decreased significantly with increasing length of stimulation and increasing total GN dose in both fresh and frozen cycles. On multivariable analysis including both days of stimulation and total GN dose, days of stimulation was no longer significantly correlated with LBR, whereas total GN dose remained significantly correlated with LBR in fresh cycles only. When total GN doses ranging from <2,000 IU through 5,000 IU to >5,000 IU were compared, a significant improvement in live birth rate was noted with lower total GN doses. Specifically, GN doses <2,000 IU had a 27% higher rate of live birth compared with GN dose >5,000 IU. For GN dose groups up to 4,000 IU, the estimated effect on LBR was similar. There was a marginal improvement (13%) in LBR with GN doses of 4,000 IU to 5,000 IU compared with >5,000 IU. When the multivariate model was applied to the frozen cycles, neither total GN dose nor days of stimulation was significantly associated with LBR. CONCLUSIONS: High total GN dose but not prolonged COH is associated with decreasing LBRs in fresh cycles, whereas neither factor significantly affects LBR in frozen cycles. Consideration should be given to minimizing the total GN dose when possible in fresh autologous cycles, either by decreasing the daily dose or by limiting the length of stimulation to improve LBRs. In freeze-all cycles, the use of higher GN doses does not seem to adversely affect the LBR of the first frozen embryo transfer. High total GN dose likely exerts a negative impact on the endometrium and/or oocyte/embryo unrelated to the length of stimulation. The differential effect of total GN dose on LBR in fresh and frozen cycles may imply a greater impact exerted on the endometrium rather than the oocyte.


Assuntos
Criopreservação , Transferência Embrionária , Fármacos para a Fertilidade Feminina/efeitos adversos , Fertilização in vitro , Gonadotropinas/efeitos adversos , Infertilidade/terapia , Síndrome de Hiperestimulação Ovariana/etiologia , Indução da Ovulação/efeitos adversos , Adulto , Bases de Dados Factuais , Transferência Embrionária/efeitos adversos , Feminino , Fertilidade , Fertilização in vitro/efeitos adversos , Humanos , Infertilidade/diagnóstico , Infertilidade/fisiopatologia , Nascido Vivo , Síndrome de Hiperestimulação Ovariana/fisiopatologia , Gravidez , Taxa de Gravidez , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
10.
J Surg Educ ; 76(6): 1516-1525, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31151829

RESUMO

OBJECTIVE: To characterize the mistreatment identified within the University of Michigan's Obstetrics and Gynecology (Ob/Gyn) clerkship and compare the rates of mistreatment to that of other clerkships in an effort to improve the learning environment. DESIGN: This is a retrospective cohort study looking at multiple sources of data from 2015 to 2018 about student mistreatment including end-of-rotation and teaching evaluations completed by students, as well as an online reporting system available to medical students. For evaluations, students were asked to rate their agreement with statements on a 5-point Likert scale (1 = strongly disagree, to 5 = strongly agree). Narrative comments were also solicited and evaluated. SETTING: University of Michigan Medical School and Michigan Medicine Ob/Gyn Department, Ann Arbor, Michigan. PARTICIPANTS: A total of 513 students rotated through the Ob/Gyn clerkship between 2015 and 2018 and were asked to complete evaluations. RESULTS: Five hundred and five of the 513 students completed evaluations between 2015 and 2018. In response to the statement, "Students are treated in a professional/respectful manner in this clerkship," the Ob/Gyn clerkship's mean scores on a 5-point scale were 4.45 (in 2015-2016), 4.52 (in 2016-2017), and 4.27 (in 2017-2018). These means, as well as the means to 3 other professionalism questions, were lower than the range of 4.42 to 4.84 for all other third-year clerkships over this time. The mean scores were also lower for Ob/gyn when compared to the Surgery clerkship. A total of 32 narrative comments were submitted by students between 2015 and 2017 related to mistreatment or unprofessional behavior. Frequent themes included students being treated as "stupid" or discouraged from asking questions (8 comments), being treated in an unprofessional manner by staff (7 comments), feeling ignored or marginalized by faculty (4 comments), and faculty unprofessional behavior toward others (4 comments). CONCLUSIONS: Students on the Ob/Gyn clerkship reported a higher rate of mistreatment compared to other clerkships. Efforts are being made by the Ob/Gyn department to communicate these data on mistreatment to educators in order to improve the Ob/Gyn culture and learning environment for medical students.


Assuntos
Bullying , Estágio Clínico , Ginecologia/educação , Obstetrícia/educação , Má Conduta Profissional , Estudantes de Medicina , Educação de Graduação em Medicina , Feminino , Humanos , Masculino , Michigan , Estudos Retrospectivos , Adulto Jovem
11.
West J Emerg Med ; 19(1): 18-22, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29383051

RESUMO

INTRODUCTION: Medical student mistreatment is a prevalent and significant challenge for medical schools across the country, associated with negative emotional and professional consequences for students. The Association of American Medical Colleges and Liaison Committee on Medical Education have increasingly emphasized the issue of mistreatment in recent years, and medical schools are tasked with creating a positive learning climate. METHODS: The authors describe the efforts of an emergency department (ED) to improve its clerkship learning environment, using a multifaceted approach for collecting mistreatment data and relaying them to educators and clerkship leadership. Data are gathered through end-of-rotation evaluations, teaching evaluations, and an online reporting system available to medical students. Mistreatment data are then relayed to the ED during semi-annual meetings between clerkship leadership and medical school assistant deans, and through annual mistreatment reports provided to department chairs. RESULTS: Over a two-year period, students submitted a total of 56 narrative comments related to mistreatment or unprofessional behavior during their emergency medicine (EM) clerkship. Of these comments, 12 were submitted in 2015-16 and 44 were submitted in 2016-17. The most frequently observed themes were students feeling ignored or marginalized by faculty (14 comments); students being prevented from speaking or working with patients and/or attending faculty (11 comments); and students being treated in an unprofessional manner by staff (other than faculty, 8 comments). CONCLUSION: This article details an ED's efforts to improve its EM clerkship learning environment by tracking mistreatment data and intentionally communicating the results to educators and clerkship leadership. Continued mistreatment data collection and faculty development will be necessary for these efforts to have a measurable effect on the learning environment.


Assuntos
Estágio Clínico , Medicina de Emergência/educação , Aprendizagem , Má Conduta Profissional/psicologia , Má Conduta Profissional/estatística & dados numéricos , Estudantes de Medicina/psicologia , Educação de Graduação em Medicina , Feminino , Humanos , Masculino
13.
Hear Res ; 328: 102-12, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26232528

RESUMO

Connexins are components of gap junctions which facilitate transfer of small molecules between cells. One member of the connexin family, Connexin 26 (Cx26), is prevalent in gap junctions in sensory epithelia of the inner ear. Mutations of GJB2, the gene encoding Cx26, cause significant hearing loss in humans. The vestibular system, however, does not usually show significant functional deficits in humans with this mutation. Mouse models for loss of Cx26 function demonstrate hearing loss and cochlear pathology but the extent of vestibular dysfunction and organ pathology are less well characterized. To understand the vestibular effects of Cx26 mutations, we evaluated vestibular function and histology of the vestibular sensory epithelia in a conditional knockout (CKO) mouse with Cx26 loss of function. Transgenic C57BL/6 mice, in which cre-Sox10 drives excision of the Cx26 gene from non-sensory cells flanking the sensory epithelium of the inner ear (Gjb2-CKO), were compared to age-matched wild types. Animals were sacrificed at ages between 4 and 40 weeks and their cochlear and vestibular sensory organs harvested for histological examination. Cx26 immunoreactivity was prominent in the peripheral vestibular system and the cochlea of wild type mice, but absent in the Gjb2-CKO specimens. The hair cell population in the cochleae of the Gjb2-CKO mice was severely depleted but in the vestibular organs it was intact, despite absence of Cx26 expression. The vestibular organs appeared normal at the latest time point examined, 40 weeks. To determine whether compensation by another connexin explains survival of the normal vestibular sensory epithelium, we evaluated the presence of Cx30 in the Gjb2-CKO mouse. We found that Cx30 labeling was normal in the cochlea, but it was decreased or absent in the vestibular system. The vestibular phenotype of the mutants was not different from wild-types as determined by time on the rotarod, head stability tests and physiological responses to vestibular stimulation. Thus presence of Cx30 in the cochlea does not compensate for Cx26 loss, and the absence of both connexins from vestibular sensory epithelia is no more injurious than the absence of one of them. Further studies to uncover the physiological foundation for this difference between the cochlea and the vestibular organs may help in designing treatments for GJB2 mutations.


Assuntos
Conexinas/fisiologia , Deleção de Genes , Vestíbulo do Labirinto/fisiologia , Animais , Cóclea/fisiologia , Conexina 26 , Conexina 30 , Conexinas/genética , Feminino , Junções Comunicantes/fisiologia , Genótipo , Células Ciliadas Auditivas/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Microscopia de Fluorescência , Mutação , Fenótipo
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