RESUMO
Biallelic mutations in interphotoreceptor matrix proteoglycan 2 (IMPG2) in humans cause retinitis pigmentosa (RP) with early macular involvement, albeit the disease progression varies widely due to genetic heterogeneity and IMPG2 mutation type. There are currently no treatments for IMPG2-RP. To aid preclinical studies toward eventual treatments, there is a need to better understand the progression of disease pathology in appropriate animal models. Toward this goal, we developed mouse models with patient mimicking homozygous frameshift (T807Ter) or missense (Y250C) Impg2 mutations, as well as mice with a homozygous frameshift mutation (Q244Ter) designed to completely prevent IMPG2 protein expression, and characterized the trajectory of their retinal pathologies across postnatal development until late adulthood. We found that the Impg2T807Ter/T807Ter and Impg2Q244Ter/Q244Ter mice exhibited early onset gliosis, impaired photoreceptor outer segment maintenance, appearance of subretinal deposits near the optic disc, disruption of the outer retina, and neurosensorial detachment, whereas the Impg2Y250C/Y250C mice exhibited minimal retinal pathology. These results demonstrate the importance of mutation type in disease progression in IMPG2-RP and provide a toolkit and preclinical data for advancing therapeutic approaches.
Assuntos
Proteoglicanas , Retinose Pigmentar , Humanos , Animais , Camundongos , Adulto , Proteoglicanas/genética , Retina , Mutação , Retinose Pigmentar/genética , Progressão da DoençaRESUMO
A variety of systemic conditions involve the thorax and the eyes. While subtle or nonspecific eye symptoms can be the initial clinical manifestation of some disorders, there can be additional manifestations in the thorax that lead to a specific diagnosis and affect patient outcomes. For instance, the initial clinical manifestation of Sjögren syndrome is dry eye or xerophthalmia; however, the presence of Sjögren lung disease represents a fourfold increase in mortality. Likewise, patients with acute sarcoidosis can initially present with pain and redness of the eye from uveitis in addition to fever and parotitis. Nearly 90% of patients with sarcoidosis have thoracic involvement, and the ophthalmologic symptoms can precede the thoracic symptoms by several years in some cases. Furthermore, a diagnosis made in one system can result in the screening of other organs as well as prompt genetic evaluation and examination of family members, such as in the setting of Marfan syndrome or Ehlers-Danlos syndrome. Multimodality imaging, particularly CT and MRI, plays a vital role in identification and characterization of these conditions. While it is helpful for ophthalmologists to be knowledgeable about these conditions and their associations so that they can order the pertinent radiologic studies, it is also important for radiologists to use the clues from ophthalmologic examination in addition to imaging findings to suggest a specific diagnosis. Systemic conditions with thoracic and ophthalmologic manifestations can be categorized as infectious, inflammatory, autoimmune, neoplastic, or hereditary in origin. The authors describe a spectrum of these conditions based on their underlying cause. ©RSNA, 2024.
Assuntos
Oftalmopatias , Doenças Torácicas , Humanos , Oftalmopatias/diagnóstico por imagem , Oftalmopatias/etiologia , Doenças Torácicas/diagnóstico por imagem , Diagnóstico Diferencial , Imagem Multimodal/métodosRESUMO
New targets for brain tumor therapies may be identified by mutations that cause hereditary microcephaly. Brain growth depends on the repeated proliferation of stem and progenitor cells. Microcephaly syndromes result from mutations that specifically impair the ability of brain progenitor or stem cells to proliferate, by inducing either premature differentiation or apoptosis. Brain tumors that derive from brain progenitor or stem cells may share many of the specific requirements of their cells of origin. These tumors may therefore be susceptible to disruptions of the protein products of genes that are mutated in microcephaly. The potential for the products of microcephaly genes to be therapeutic targets in brain tumors are highlighted hereby reviewing research on EG5, KIF14, ASPM, CDK6, and ATR. Treatments that disrupt these proteins may open new avenues for brain tumor therapy that have increased efficacy and decreased toxicity.
Assuntos
Neoplasias Encefálicas/patologia , Microcefalia/patologia , Animais , Encéfalo/patologia , Diferenciação Celular/fisiologia , Glioma/patologia , Humanos , Meduloblastoma/patologia , Mitose/fisiologiaRESUMO
Microcephaly and medulloblastoma may both result from mutations that compromise genomic stability. We report that ATR, which is mutated in the microcephalic disorder Seckel syndrome, sustains cerebellar growth by maintaining chromosomal integrity during postnatal neurogenesis. Atr deletion in cerebellar granule neuron progenitors (CGNPs) induced proliferation-associated DNA damage, p53 activation, apoptosis and cerebellar hypoplasia in mice. Co-deletions of either p53 or Bax and Bak prevented apoptosis in Atr-deleted CGNPs, but failed to fully rescue cerebellar growth. ATR-deficient CGNPs had impaired cell cycle checkpoint function and continued to proliferate, accumulating chromosomal abnormalities. RNA-Seq demonstrated that the transcriptional response to ATR-deficient proliferation was highly p53 dependent and markedly attenuated by p53 co-deletion. Acute ATR inhibition in vivo by nanoparticle-formulated VE-822 reproduced the developmental disruptions seen with Atr deletion. Genetic deletion of Atr blocked tumorigenesis in medulloblastoma-prone SmoM2 mice. Our data show that p53-driven apoptosis and cell cycle arrest - and, in the absence of p53, non-apoptotic cell death - redundantly limit growth in ATR-deficient progenitors. These mechanisms may be exploited for treatment of CGNP-derived medulloblastoma using ATR inhibition.
Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Cerebelares/genética , Cerebelo/crescimento & desenvolvimento , Instabilidade Cromossômica/genética , Meduloblastoma/genética , Neurogênese/genética , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/fisiologia , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias Cerebelares/patologia , Cerebelo/anormalidades , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Cerebelo/patologia , Instabilidade Cromossômica/efeitos dos fármacos , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Feminino , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Isoxazóis/farmacologia , Masculino , Meduloblastoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/patologia , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Pirazinas/farmacologiaRESUMO
INTRODUCTION AND HYPOTHESIS: Urethral injury resulting from transvaginal mesh slings is a rare complication with an estimated incidence of <1%. Our objective was to review the surgical management and functional outcomes of women presenting with urethral mesh perforation following midurethral sling (MUS) placement. METHODS: This was a retrospective multicenter review of women who from January 2011 to March 2016 at two institutions underwent mesh sling excision for urethral perforation with Female Pelvic Medicine and Reconstructive Surgery fellowship-trained surgeons. Data comprising preoperative symptoms, operative details, and postoperative outcomes were collected by telephone (n 13) or based on their last follow-up appointment. RESULTS OBTAINED: Nineteen women underwent transvaginal sling excision for urethral mesh perforation. Eight (42%) patients had undergone previous sling revision surgery. Sixty percent of women had resolution of their pelvic pain postoperatively. At follow-up, 92% reported urinary incontinence (UI), and three had undergone five additional procedures for vaginal prolapse mesh exposure (n 1), incontinence (onabotulinum toxin injection n 1, rectus fascia autologous sling n 1), prolapse (colpopexy n 1), and pain (trigger-point injection n 1). Patient global impression of improvement data was available for 13 patients, of whom seven (54%) rated their postoperative condition as Very much better or Much better. CONCLUSIONS: The management of urethral mesh perforation is complex. Most women reported resolution of their pelvic pain and a high rate of satisfaction with their postoperative condition despite high rates of incontinence.
Assuntos
Slings Suburetrais/efeitos adversos , Telas Cirúrgicas , Uretra/lesões , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Uretra/cirurgia , Incontinência Urinária por Estresse/prevenção & controle , Incontinência Urinária por Estresse/cirurgia , Incontinência Urinária de UrgênciaRESUMO
OBJECTIVES: The length of the third stage of labor is correlated with blood loss following a vaginal delivery. We aimed to accurately measure blood loss following a vaginal delivery and examine the relation between blood loss and length of the third stage of labor. METHODS: This was a prospective observational study of singleton pregnancies ≥24 weeks undergoing a vaginal delivery. Blood loss was meticulously measured and the length of the third stage of labor was recorded. RESULTS: The median blood loss of the 600 women was 125 mL (interquartile range 175) and the median length of the third stage of labor was 5 minutes (interquartile range 4). Total blood loss (P = 0.0263) and length of the third stage of labor (P = 0.0120) were greater in pregnancies ≥37 weeks versus <37 weeks. Women with a third stage of labor ≥15 minutes had a significantly greater risk of blood loss >500 mL (relative risk 5.8, 95% confidence interval 8.36-29.88). CONCLUSIONS: The median blood loss following a vaginal delivery is 125 mL and the median length of the third stage of labor is 5 minutes. Total blood loss and the length of the third stage of labor are greater in pregnancies >37 weeks. Women with a third stage of labor >15 minutes are 15.8 times more likely to have total blood loss ≥500 mL. As such, it is prudent to consider manual extraction of the placenta at 15 minutes rather than 30 minutes to minimize the risk of excessive blood loss.
Assuntos
Parto Obstétrico , Terceira Fase do Trabalho de Parto/fisiologia , Hemorragia Pós-Parto/etiologia , Adulto , Feminino , Humanos , Hemorragia Pós-Parto/diagnóstico , Gravidez , Estudos Prospectivos , Análise de Regressão , Fatores de Risco , Fatores de TempoRESUMO
PURPOSE OF REVIEW: The purpose of this review is to discuss the available energy sources used in the vaginal canal that are currently being promoted for certain pelvic floor conditions and explore the body of peer-reviewed literature supporting their use. RECENT FINDINGS: The majority of research has focused on the use of fractional CO2 laser treatment for genitourinary syndrome of menopause (GSM). Most of these studies are nonrandomized prospective studies, but their data consistently shows an improvement in symptoms without significant side effects. SUMMARY: Vaginal laser treatment for GSM is of particular interest to gynecologists as it provides patients with a history of estrogen receptor positive breast cancer, thromboembolic event, or other contraindication to hormone therapy, an effective treatment option. Currently, we are in the early stages of scientific investigation into the use of lasers in the treatment of pelvic floor dysfunction, but the emerging data is encouraging. The existing data is limited to mostly observational studies with additional quality randomized controlled trials and sham studies needed to ensure that physicians are providing the optimum evidence-based treatments to their patients. At the present time there is insufficient data to promote these therapies for stress incontinence, vaginal tightening, or other pelvic floor abnormalities.
Assuntos
Disuria/cirurgia , Lasers de Gás/uso terapêutico , Lasers de Estado Sólido/uso terapêutico , Distúrbios do Assoalho Pélvico/cirurgia , Incontinência Urinária por Estresse/cirurgia , Infecções Urinárias/cirurgia , Ablação por Cateter , Feminino , Humanos , Terapia a Laser/métodos , Menopausa , Distúrbios do Assoalho Pélvico/complicações , Distúrbios do Assoalho Pélvico/fisiopatologia , SíndromeRESUMO
PURPOSE OF REVIEW: The purpose of this review is to summarize the treatment options for anterior compartment prolapse, describe the role that apical suspension plays in the correction of anterior vaginal wall prolapse, and assess the risks and benefits of biologic and synthetic graft use in anterior compartment repair. RECENT FINDINGS: In 2016, The Cochrane Review published a review of 37 trials including 4023 participants finding that compared to native tissue repair, the use of synthetic mesh resulted in reduced symptomatic prolapse recurrence, anatomic recurrence, and repeat prolapse surgery. There was insufficient evidence regarding quality of life improvement or the use of biologic grafts. Of note the differences between native tissue and mesh kit repairs were not large. SUMMARY: A strong consideration should be on the correction of apical prolapse when present; isolated anterior wall repairs should be pursued with caution. The surgeon may consider the use of augmenting materials in their repair of anterior vaginal wall prolapse, although the available evidence is not strongly supportive of their use given potential risks.
Assuntos
Procedimentos Cirúrgicos em Ginecologia/métodos , Prolapso de Órgão Pélvico/cirurgia , Telas Cirúrgicas , Feminino , Humanos , Prolapso de Órgão Pélvico/epidemiologia , Prolapso de Órgão Pélvico/patologiaRESUMO
INTRODUCTION AND HYPOTHESIS: Entry into the peritoneal cavity can be challenging in patients with posthysterectomy prolapse; however, it is important for vaginal surgeons to be able to enter the peritoneal cavity using various techniques to perform an intraperitoneal vaginal vault suspension. METHODS: We present surgical footage of various methods of accessing the peritoneal cavity in posthysterectomy prolapse using posterior, anterior and apical approaches. RESULTS: This video highlights surgical techniques that can be used to enter the peritoneal cavity in posthysterectomy prolapse in a safe and reliable manner. CONCLUSIONS: Vaginal surgeons should be able to safely and confidently identify and enter the peritoneal cavity using various approaches to perform an intraperitoneal vaginal vault suspension.
Assuntos
Histerectomia/efeitos adversos , Prolapso de Órgão Pélvico/cirurgia , Cavidade Peritoneal/cirurgia , Complicações Pós-Operatórias/cirurgia , Procedimentos Cirúrgicos Urogenitais/métodos , Feminino , Humanos , Prolapso de Órgão Pélvico/etiologia , Complicações Pós-Operatórias/etiologia , Procedimentos Cirúrgicos Urogenitais/educação , Vagina/cirurgiaRESUMO
OBJECTIVES: The purpose of this study is to assess patient's satisfaction treatment outcomes and out-of-pocket expense for the fractional CO2 laser (SmartXide) in the treatment of genitourinary symptoms of menopause (GSM). MATERIALS AND METHODS: A multicenter retrospective cohort study of patients who completed a course of three vaginal treatments with the SmartXide11 Fractional CO2 laser. Patients contacted via telephone and asked to participate in questionnaires to evaluate for adverse outcomes since last treatment, symptom severity before and after treatment, patient satisfaction with treatment, patient satisfaction with out-of-pocket expense, and sexual function. RESULTS: Of the 368 patients contacted, 122 agreed to be interviewed. No patients reported seeking emergent medical treatment. Patient reported vaginal dryness significantly improved following treatment (P < 0.05). The frequency of intercourse increased from "once a month" to "few times a month" (P < 0.001). The vast majority of patients reported being satisfied with their treatment results (86%) and with the cost of treatment (78%). Satisfaction with the out-of-pocket expense did not correlate with household income (P = 0.07). CONCLUSION: The SmartXide Fractional CO2 laser is a safe and efficacious treatment for GSM. This treatment is associated with a high level of patient satisfaction with both treatment results and out-of-pocket expense. Lasers Surg. Med. 49:882-885, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Dispareunia/cirurgia , Gastos em Saúde , Lasers de Gás/uso terapêutico , Menopausa , Vagina/cirurgia , Doenças Vaginais/cirurgia , Idoso , Dispareunia/economia , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Retrospectivos , Síndrome , Resultado do Tratamento , Estados Unidos , Doenças Vaginais/economiaRESUMO
INTRODUCTION: We present an uncommon complication of vaginally placed synthetic prolapse mesh and demonstrate repair of rectal mesh perforation. METHODS: A 41-year-old was referred with multiple complaints following rectocele repair using a posterior vaginal mesh kit 5 months earlier. In the immediate postoperative period, she experienced severe pain radiating down her right leg, pelvic pain, dyspareunia, dyschezia, diarrhea, and new onset fecal incontinence. Our examination revealed tight, tender mesh arms palpable at the vaginal apex with no evidence of erosion or rectovaginal fistula. Rectal examination revealed intrarectal mesh traversing the rectal lumen 6 cm from the anal verge. Pelvic MRI demonstrated a possible rectovaginal fistula with inflammation surrounding the right sciatic nerve plexus. The patient underwent exploratory laparotomy, removal of the mesh, primary repair of two perforating rectal defects and diverting loop ileostomy. Postoperatively she experienced immediate improvement in pain and later underwent successful take-down of her ileostomy. She did well with improvement of bowel function, continence of feces, improvement of pain, and no recurrence of prolapse. CONCLUSION: Our video shows an abdominal approach for mesh removal and repair of rectal mesh injury occurring from vaginal mesh placement. We discuss the rationale for the abdominal approach and review techniques for proper placement of posterior vaginal mesh.
Assuntos
Remoção de Dispositivo/métodos , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Retocele/cirurgia , Telas Cirúrgicas/efeitos adversos , Adulto , Feminino , Humanos , Doença Iatrogênica , Complicações Pós-Operatórias/cirurgia , Reto/lesõesRESUMO
The superior olivary complex (SOC) is an essential auditory brainstem relay involved in sound localization. To identify the genetic program underlying its maturation, we profiled the rat SOC transcriptome at postnatal days 0, 4, 16, and 25 (P0, P4, P16, and P25, respectively), using genome-wide microarrays (41,012 oligonucleotides (oligos)). Differences in gene expression between two consecutive stages were highest between P4 and P16 (3.6%) and dropped to 0.06% between P16 and P25. To identify SOC-related genetic programs, we also profiled the entire brain at P4 and P25. The number of differentially expressed oligonucleotides between SOC and brain almost doubled from P4 to P25 (4.4% versus 7.6%). These data demonstrate considerable molecular specification around hearing onset, which is rapidly finalized. Prior to hearing onset, several transcription factors associated with the peripheral auditory system were up-regulated, probably coordinating the development of the auditory system. Additionally, crystallin-γ subunits and serotonin-related genes were highly expressed. The molecular repertoire of mature neurons was sculpted by SOC-related up- and down-regulation of voltage-gated channels and G-proteins. Comparison with the brain revealed a significant enrichment of hearing impairment-related oligos in the SOC (26 in the SOC, only 11 in the brain). Furthermore, 29 of 453 SOC-related oligos mapped within 19 genetic intervals associated with hearing impairment. Together, we identified sequential genetic programs in the SOC, thereby pinpointing candidates that may guide its development and ensure proper function. The enrichment of hearing impairment-related genes in the SOC may have implications for restoring hearing because central auditory structures might be more severely affected than previously appreciated.
Assuntos
Tronco Encefálico , Regulação da Expressão Gênica/fisiologia , Audição/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Transcriptoma/fisiologia , Animais , Animais Recém-Nascidos , Tronco Encefálico/citologia , Tronco Encefálico/crescimento & desenvolvimento , Tronco Encefálico/metabolismo , Feminino , Humanos , Masculino , Proteínas do Tecido Nervoso/genética , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Sprague-DawleyRESUMO
Hypertrophic cardiomyopathy (HCM) is characterized by asymmetric left ventricular hypertrophy, diastolic dysfunction and myocardial disarray. HCM is caused by mutations in sarcomeric genes, but in >40% of patients, the mutation is not yet identified. We hypothesized that FHL1, encoding four-and-a-half-LIM domains 1, could be another disease gene since it has been shown to cause distinct myopathies, sometimes associated with cardiomyopathy. We evaluated 121 HCM patients, devoid of a mutation in known disease genes. We identified three novel variants in FHL1 (c.134delA/K45Sfs, c.459C>A/C153X and c.827G>C/C276S). Whereas the c.459C>A variant was associated with muscle weakness in some patients, the c.134delA and c.827G>C variants were associated with isolated HCM. Gene transfer of the latter variants in C2C12 myoblasts and cardiac myocytes revealed reduced levels of FHL1 mutant proteins, which could be rescued by proteasome inhibition. Contractility measurements after adeno-associated virus transduction in rat-engineered heart tissue (EHT) showed: (i) higher and lower forces of contraction with K45Sfs and C276S, respectively, and (ii) prolonged contraction and relaxation with both mutants. All mutants except one activated the fetal hypertrophic gene program in EHT. In conclusion, this study provides evidence for FHL1 to be a novel gene for isolated HCM. These data, together with previous findings of proteasome impairment in HCM, suggest that FHL1 mutant proteins may act as poison peptides, leading to hypertrophy, diastolic dysfunction and/or altered contractility, all features of HCM.
Assuntos
Cardiomiopatia Hipertrófica/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas com Domínio LIM/genética , Proteínas Musculares/genética , Adolescente , Adulto , Idoso , Animais , Cardiomiopatia Hipertrófica/metabolismo , Estudos de Casos e Controles , Células Cultivadas , Criança , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas com Domínio LIM/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Proteínas Musculares/metabolismo , Mutação , Miócitos Cardíacos/metabolismo , Linhagem , Adulto JovemRESUMO
PURPOSE: To develop uniform and reliable reference ranges for amniotic fluid volume (AFV) across gestation in normal singleton pregnancies using quantile regression (QR). METHODS: An analysis of true AFVs determined by dye-dilution techniques or by direct measurement at cesarean delivery in normal singleton pregnancies. AFV centiles were established by QR, a flexible semi-parametric approach of estimating rates of change across the entire distribution of AFV rather than just in the mean as is observed with standard linear regression. RESULTS: The study evaluated 379 women with normal singleton pregnancies between 16 and 41 weeks gestation. QR was used to determine the association between AFV and gestational age (GA). A second-order quantile regression model indicated a nonlinear relationship between AFV and gestational age at the upper centile range (≥80th percentile). CONCLUSION: This study defines normative centile charts for true AFVs between 16 and 41 weeks gestation in normal singleton pregnancies using QR. This statistical approach more appropriately reflects true AFV across gestation at each centile of interest (e.g. 5th, 50th, 95th, etc.) as compared to standard linear regression.
Assuntos
Líquido Amniótico/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Adulto , Cesárea , Técnica de Diluição de Corante , Feminino , Idade Gestacional , Humanos , Mississippi , Oligo-Hidrâmnio/diagnóstico por imagem , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Valores de Referência , Análise de RegressãoRESUMO
RATIONALE: Telethonin (also known as titin-cap or t-cap) is a 19-kDa Z-disk protein with a unique ß-sheet structure, hypothesized to assemble in a palindromic way with the N-terminal portion of titin and to constitute a signalosome participating in the process of cardiomechanosensing. In addition, a variety of telethonin mutations are associated with the development of several different diseases; however, little is known about the underlying molecular mechanisms and telethonin's in vivo function. OBJECTIVE: Here we aim to investigate the role of telethonin in vivo and to identify molecular mechanisms underlying disease as a result of its mutation. METHODS AND RESULTS: By using a variety of different genetically altered animal models and biophysical experiments we show that contrary to previous views, telethonin is not an indispensable component of the titin-anchoring system, nor is deletion of the gene or cardiac specific overexpression associated with a spontaneous cardiac phenotype. Rather, additional titin-anchorage sites, such as actin-titin cross-links via α-actinin, are sufficient to maintain Z-disk stability despite the loss of telethonin. We demonstrate that a main novel function of telethonin is to modulate the turnover of the proapoptotic tumor suppressor p53 after biomechanical stress in the nuclear compartment, thus linking telethonin, a protein well known to be present at the Z-disk, directly to apoptosis ("mechanoptosis"). In addition, loss of telethonin mRNA and nuclear accumulation of this protein is associated with human heart failure, an effect that may contribute to enhanced rates of apoptosis found in these hearts. CONCLUSIONS: Telethonin knockout mice do not reveal defective heart development or heart function under basal conditions, but develop heart failure following biomechanical stress, owing at least in part to apoptosis of cardiomyocytes, an effect that may also play a role in human heart failure.
Assuntos
Insuficiência Cardíaca/metabolismo , Coração/fisiopatologia , Mecanotransdução Celular , Proteínas Musculares/deficiência , Miocárdio/metabolismo , Adaptação Fisiológica , Animais , Animais Geneticamente Modificados , Apoptose , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Conectina , Modelos Animais de Doenças , Ecocardiografia , Fibrose , Genótipo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Camundongos , Camundongos Knockout , Proteínas Musculares/genética , Miocárdio/patologia , Fenótipo , Interferência de RNA , Ratos , Sarcômeros/metabolismo , Estresse Mecânico , Transfecção , Proteína Supressora de Tumor p53/metabolismoRESUMO
Clinical trials seeking type 1 diabetes prevention are challenging in terms of identifying patient populations likely to progress to type 1 diabetes within limited (i.e., short-term) trial durations. Hence, we sought to improve such efforts by developing a quantitative disease progression model for type 1 diabetes. Individual-level data obtained from the TrialNet Pathway to Prevention and The Environmental Determinants of Diabetes in the Young natural history studies were used to develop a joint model that links the longitudinal glycemic measure to the timing of type 1 diabetes diagnosis. Baseline covariates were assessed using a stepwise covariate modeling approach. Our study focused on individuals at risk of developing type 1 diabetes with the presence of two or more diabetes-related autoantibodies (AAbs). The developed model successfully quantified how patient features measured at baseline, including HbA1c and the presence of different AAbs, alter the timing of type 1 diabetes diagnosis with reasonable accuracy and precision (<30% RSE). In addition, selected covariates were statistically significant (p < 0.0001 Wald test). The Weibull model best captured the timing to type 1 diabetes diagnosis. The 2-h oral glucose tolerance values assessed at each visit were included as a time-varying biomarker, which was best quantified using the sigmoid maximum effect function. This model provides a framework to quantitatively predict and simulate the time to type 1 diabetes diagnosis in individuals at risk of developing the disease and thus, aligns with the needs of pharmaceutical companies and scientists seeking to advance therapies aimed at interdicting the disease process.
Assuntos
Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/prevenção & controle , Teste de Tolerância a Glucose , Autoanticorpos , Progressão da Doença , Glicemia/metabolismoRESUMO
The development of therapies to prevent or delay the onset of type 1 diabetes (T1D) remains challenging, and there is a lack of qualified biomarkers to identify individuals at risk of developing T1D or to quantify the time-varying risk of conversion to a diagnosis of T1D. To address this drug development need, the T1D Consortium (i) acquired, remapped, integrated, and curated existing patient-level data from relevant observational studies, and (ii) used a model-based approach to evaluate the utility of islet autoantibodies (AAs) against insulin/proinsulin autoantibody, GAD65, IA-2, and ZnT8 as biomarkers to enrich subjects for T1D prevention. The aggregated dataset was used to construct an accelerated failure time model for predicting T1D diagnosis. The model quantifies presence of islet AA permutations as statistically significant predictors of the time-varying probability of conversion to a diagnosis of T1D. Additional sources of variability that greatly improved the accuracy of quantifying the time-varying probability of conversion to a T1D diagnosis included baseline age, sex, blood glucose measurements from the 120-minute timepoints of oral glucose tolerance tests, and hemoglobin A1c. The developed models represented the underlying evidence to qualify islet AAs as enrichment biomarkers through the qualification of novel methodologies for drug development pathway at the European Medicines Agency (EMA). Additionally, the models are intended as the foundation of a fully functioning end-user tool that will allow sponsors to optimize enrichment criteria for clinical trials in T1D prevention studies.
Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Autoanticorpos/genética , Biomarcadores , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/prevenção & controle , Hemoglobinas Glicadas , HumanosRESUMO
Chromosome 15q11.2-q13.1 duplication syndrome (Dup15q syndrome) is a severe neurodevelopmental disorder characterized by intellectual disability, impaired motor coordination, and autism spectrum disorder. Chromosomal multiplication of the UBE3A gene is presumed to be the primary driver of Dup15q pathophysiology, given that UBE3A exhibits maternal monoallelic expression in neurons and that maternal duplications typically yield far more severe neurodevelopmental outcomes than paternal duplications. However, studies into the pathogenic effects of UBE3A overexpression in mice have yielded conflicting results. Here, we investigated the neurodevelopmental impact of Ube3a gene overdosage using bacterial artificial chromosome-based transgenic mouse models (Ube3aOE) that recapitulate the increases in Ube3a copy number most often observed in Dup15q. In contrast to previously published Ube3a overexpression models, Ube3aOE mice were indistinguishable from wild-type controls on a number of molecular and behavioral measures, despite suffering increased mortality when challenged with seizures, a phenotype reminiscent of sudden unexpected death in epilepsy. Collectively, our data support a model wherein pathogenic synergy between UBE3A and other overexpressed 15q11.2-q13.1 genes is required for full penetrance of Dup15q syndrome phenotypes.
Assuntos
Transtorno do Espectro Autista , Deficiência Intelectual , Animais , Aberrações Cromossômicas , Cromossomos Humanos Par 15 , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Camundongos , Camundongos Transgênicos , Ubiquitina-Proteína Ligases/genéticaRESUMO
The sarcomeric titin springs influence myocardial distensibility and passive stiffness. Titin isoform composition and protein kinase (PK)A-dependent titin phosphorylation are variables contributing to diastolic heart function. However, diastolic tone, relaxation speed, and left ventricular extensibility are also altered by PKG activation. We used back-phosphorylation assays to determine whether PKG can phosphorylate titin and affect titin-based stiffness in skinned myofibers and isolated myofibrils. PKG in the presence of 8-pCPT-cGMP (cGMP) phosphorylated the 2 main cardiac titin isoforms, N2BA and N2B, in human and canine left ventricles. In human myofibers/myofibrils dephosphorylated before mechanical analysis, passive stiffness dropped 10% to 20% on application of cGMP-PKG. Autoradiography and anti-phosphoserine blotting of recombinant human I-band titin domains established that PKG phosphorylates the N2-B and N2-A domains of titin. Using site-directed mutagenesis, serine residue S469 near the COOH terminus of the cardiac N2-B-unique sequence (N2-Bus) was identified as a PKG and PKA phosphorylation site. To address the mechanism of the PKG effect on titin stiffness, single-molecule atomic force microscopy force-extension experiments were performed on engineered N2-Bus-containing constructs. The presence of cGMP-PKG increased the bending rigidity of the N2-Bus to a degree that explained the overall PKG-mediated decrease in cardiomyofibrillar stiffness. Thus, the mechanically relevant site of PKG-induced titin phosphorylation is most likely in the N2-Bus; phosphorylation of other titin sites could affect protein-protein interactions. The results suggest that reducing titin stiffness by PKG-dependent phosphorylation of the N2-Bus can benefit diastolic function. Failing human hearts revealed a deficit for basal titin phosphorylation compared to donor hearts, which may contribute to diastolic dysfunction in heart failure.
Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/fisiologia , Insuficiência Cardíaca Diastólica/metabolismo , Ventrículos do Coração/metabolismo , Proteínas Musculares/metabolismo , Proteínas Quinases/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Animais , Conectina , Sequência Consenso , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , GMP Cíclico/fisiologia , Cães , Elasticidade , Humanos , Dados de Sequência Molecular , Proteínas Musculares/genética , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Miofibrilas/efeitos dos fármacos , Miofibrilas/ultraestrutura , Óxido Nítrico/fisiologia , Fosforilação , Isoformas de Proteínas/metabolismo , Proteínas Quinases/genética , Proteínas Recombinantes de Fusão/fisiologia , Sarcômeros/metabolismo , Sarcômeros/ultraestrutura , Relação Estrutura-Atividade , Remodelação Ventricular/fisiologiaRESUMO
Ureteroarterial fistula is a rare condition wherein a communication develops between a ureter and the common, internal, or external iliac artery. Localizing the fistula can be difficult, as cystoscopy, CT angiography, and conventional angiography have low sensitivity in identifying the fistula. Provocative maneuvers within the ureter, however, can aid in the visualization of fistulae on angiography. Prior reports of endovascular repair have utilized transfemoral access, which makes performing concurrent provocative maneuvers in the ureter challenging. We present a case of successful endovascular ureteroarterial fistula localization and embolization in an 80-year-old woman with recurrent gross hematuria by the transradial approach, aided by concurrent provocative maneuvers performed via cystoscopy. The transradial endovascular approach facilitated a multi-disciplinary joint procedure that resulted in effective treatment of the patient.