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Segregation of nonexchange chromosomes during Drosophila melanogaster meiosis requires the proper function of NOD, a nonmotile kinesin-10. We have determined the X-ray crystal structure of the NOD catalytic domain in the ADP- and AMPPNP-bound states. These structures reveal an alternate conformation of the microtubule binding region as well as a nucleotide-sensitive relay of hydrogen bonds at the active site. Additionally, a cryo-electron microscopy reconstruction of the nucleotide-free microtubule-NOD complex shows an atypical binding orientation. Thermodynamic studies show that NOD binds tightly to microtubules in the nucleotide-free state, yet other nucleotide states, including AMPPNP, are weakened. Our pre-steady-state kinetic analysis demonstrates that NOD interaction with microtubules occurs slowly with weak activation of ADP product release. Upon rapid substrate binding, NOD detaches from the microtubule prior to the rate-limiting step of ATP hydrolysis, which is also atypical for a kinesin. We propose a model for NOD's microtubule plus-end tracking that drives chromosome movement.
Assuntos
Cromossomos/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Proteínas dos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Nucleotídeos de Adenina/química , Adenosina Trifosfatases/metabolismo , Animais , Drosophila melanogaster/metabolismo , Cinesinas , Meiose , Microtúbulos/químicaRESUMO
ABSTRACT: Uterine leiomyomas are the most common pelvic tumor in women and the most frequent indication for hysterectomy. Although benign lesions, leiomyomas can cause dysfunctional uterine bleeding, pelvic pain or discomfort, infertility, and spontaneous abortion. Despite the fact that uterine leiomyomas can result in a significant amount of morbidity, it is relatively rare for these common tumors to lead to death. Here we present a case of fatal pulmonary thromboembolism that occurred due to pelvic vein thrombosis in the setting of leiomyomas.
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Zinc is an essential trace element that acts as a co-factor for many enzymes and transcription factors required for cellular growth and development. Altering intracellular zinc levels can produce dramatic effects ranging from cell proliferation to cell death. To avoid such fates, cells have evolved mechanisms to handle both an excess and a deficiency of zinc. Zinc homeostasis is largely maintained via zinc transporters, permeable channels, and other zinc-binding proteins. Variation in these proteins might affect their ability to interact with zinc, leading to either increased sensitivity or resistance to natural zinc fluctuations in the environment. We can leverage the power of the roundworm nematode Caenorhabditis elegans as a tractable metazoan model for quantitative genetics to identify genes that could underlie variation in responses to zinc. We found that the laboratory-adapted strain (N2) is resistant and a natural isolate from Hawaii (CB4856) is sensitive to micromolar amounts of exogenous zinc supplementation. Using a panel of recombinant inbred lines, we identified two large-effect quantitative trait loci (QTL) on the left arm of chromosome III and the center of chromosome V that are associated with zinc responses. We validated and refined both QTL using near-isogenic lines (NILs) and identified a naturally occurring deletion in sqst-5, a sequestosome-related gene, that is associated with resistance to high exogenous zinc. We found that this deletion is relatively common across strains within the species and that variation in sqst-5 is associated with zinc resistance. Our results offer a possible mechanism for how organisms can respond to naturally high levels of zinc in the environment and how zinc homeostasis varies among individuals.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Caenorhabditis elegans/genética , Zinco/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Mapeamento Cromossômico/métodos , Variação Genética , Homeostase , Locos de Características Quantitativas , Zinco/metabolismo , Dedos de ZincoRESUMO
BACKGROUND: Idiopathic nodular mesangial sclerosis, also called idiopathic nodular glomerulosclerosis (ING), is a rare clinical entity with an unclear pathogenesis. The hallmark of this disease is the presence of nodular mesangial sclerosis on histology without clinical evidence of diabetes mellitus or other predisposing diagnoses. To achieve insights into its pathogenesis, we queried the clinical, histopathologic and transcriptomic features of ING and nodular diabetic nephropathy (DN). METHODS: All renal biopsy reports accessioned at Indiana University Health from 2001 to 2016 were reviewed to identify 48 ING cases. Clinical and histopathologic features were compared between individuals with ING and DN (n = 751). Glomeruli of ING (n = 5), DN (n = 18) and reference (REF) nephrectomy (n = 9) samples were isolated by laser microdissection and RNA was sequenced. Immunohistochemistry of proline-rich 36 (PRR36) protein was performed. RESULTS: ING subjects were frequently hypertensive (95.8%) with a smoking history (66.7%). ING subjects were older, had lower proteinuria and had less hyaline arteriolosclerosis than DN subjects. Butanoate metabolism was an enriched pathway in ING samples compared with either REF or DN samples. The top differentially expressed gene, PRR36, had increased expression in glomeruli 248-fold [false discovery rate (FDR) P = 5.93 × 10-6] compared with the REF and increased 109-fold (FDR P = 1.85 × 10-6) compared with DN samples. Immunohistochemistry revealed a reduced proportion of cells with perinuclear reaction in ING samples as compared to DN. CONCLUSIONS: Despite similar clinical and histopathologic characteristics in ING and DN, the uncovered transcriptomic signature suggests that ING has distinct molecular features from nodular DN. Further study is warranted to understand these relationships.
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Diabetes Mellitus , Nefropatias Diabéticas , Síndrome Nefrótica , Diabetes Mellitus/patologia , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Humanos , Glomérulos Renais/patologia , Síndrome Nefrótica/patologia , Proteinúria/patologia , Esclerose/patologiaRESUMO
BACKGROUND: Social determinants of health (SDoH) play an important role in pediatric health outcomes. Trainees receive little to no training on how to identify, discuss and counsel families in a clinical setting. The aim of this study was to determine if a simulation-based SDoH training activity would improve pediatric resident comfort with these skills. METHODS: We performed a prospective study of a curricular intervention involving simulation cases utilizing standardized patients focused on four social determinants (food insecurity, housing insecurity, barriers to accessing care, and adverse childhood experiences [ACEs]). Residents reported confidence levels with discussing each SDoH and satisfaction with the activity in a retrospective pre-post survey with five-point Likert style questions. Select residents were surveyed again 9-12 months after participation. RESULTS: 85% (33/39) of residents expressed satisfaction with the simulation activity. More residents expressed comfort discussing each SDoH after the activity (Δ% 38-47%; all p < .05), with the greatest effect noted in post-graduate-year-1 (PGY-1) participants. Improvements in comfort were sustained longitudinally during the academic year. More PGY-1 participants reported engaging in ≥ 2 conversations in a clinical setting related to food insecurity (43% vs. 5%; p = .04) and ACEs (71% vs. 20%; p = .02). DISCUSSION: Simulation led to an increased resident comfort with discussing SDoH in a clinical setting. The greatest benefit from such a curriculum is likely realized early in training. Future efforts should investigate if exposure to the simulations and increased comfort level with each topic correlate with increased likelihood to engage in these conversations in the clinical setting.
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Internato e Residência , Determinantes Sociais da Saúde , Criança , Instabilidade Habitacional , Humanos , Estudos Prospectivos , Estudos RetrospectivosRESUMO
Chronic administration of efavirenz is associated with decreased serum bilirubin levels, probably through induction of UGT1A1 We assessed the impact of efavirenz monotherapy and UGT1A1 phenotypes on total, conjugated, and unconjugated serum bilirubin levels in healthy volunteers. Healthy volunteers were enrolled into a clinical study designed to address efavirenz pharmacokinetics, drug interactions, and pharmacogenetics. Volunteers received multiple oral doses (600 mg/day for 17 days) of efavirenz. Serum bilirubin levels were obtained at study entry and 1 week after completion of the study. DNA genotyping was performed for UGT1A1 [*80 (C>T), *6 (G>A), *28 (TA7), *36 (TA5), and *37 (TA8)] and for SLCO1B1 [*5 (521T>C) and *1b (388A>G] variants. Diplotype predicted phenotypes were classified as normal, intermediate, and slow metabolizers. Compared with bilirubin levels at screening, treatment with efavirenz significantly reduced total, conjugated, and unconjugated bilirubin. After stratification by UGT1A1 phenotypes, there was a significant decrease in total bilirubin among all phenotypes, conjugated bilirubin among intermediate metabolizers, and unconjugated bilirubin among normal and intermediate metabolizers. The data also show that UGT1A1 genotype predicts serum bilirubin levels at baseline, but this relationship is lost after efavirenz treatment. SLCO1B1 genotypes did not predict bilirubin levels at baseline or after efavirenz treatment. Our data suggest that efavirenz may alter bilirubin disposition mainly through induction of UGT1A1 metabolism and efflux through multidrug resistance-associated protein 2. SIGNIFICANCE STATEMENT: Efavirenz likely alters the pharmacokinetics of coadministered drugs, potentially causing lack of efficacy or increased adverse effects, as well as the disposition of endogenous compounds relevant in homeostasis through upregulation of UGT1A1 and multidrug resistance-associated protein 2. Measurement of unconjugated and conjugated bilirubin during new drug development may provide mechanistic understanding regarding enzyme and transporters modulated by the new drug.
Assuntos
Alcinos/farmacologia , Benzoxazinas/farmacologia , Bilirrubina/metabolismo , Ciclopropanos/farmacologia , Glucuronosiltransferase/genética , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Adulto , Feminino , Genótipo , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Fenótipo , Adulto JovemRESUMO
BACKGROUND: Despite its approval in 1953, hydralazine hydrochloride continues to be used in the management of resistant hypertension, a condition frequently managed by nephrologists and other clinicians. Hydralazine hydrochloride undergoes metabolism by the N-acetyltransferase 2 (NAT2) enzyme. NAT2 is highly polymorphic as approximately 50% of the general population are slow acetylators. In this review, we first evaluate the link between NAT2 genotype and phenotype. We then assess the evidence available for genotype-guided therapy of hydralazine, specifically addressing associations of NAT2 acetylator status with hydralazine pharmacokinetics, antihypertensive efficacy, and toxicity. SUMMARY: There is a critical need to use hydralazine in some patients with resistant hypertension. Available evidence supports a significant link between genotype and NAT2 enzyme activity as 29 studies were identified with an overall concordance between genotype and phenotype of 92%. The literature also supports an association between acetylator status and hydralazine concentration, as fourteen of fifteen identified studies revealed significant relationships with a consistent direction of effect. Although fewer studies are available to directly link acetylator status with hydralazine antihypertensive efficacy, the evidence from this smaller set of studies is significant in 7 of 9 studies identified. Finally, 5 studies were identified which support the association of acetylator status with hydralazine-induced lupus. Clinicians should maintain vigilance when prescribing maximum doses of hydralazine. Key Messages: NAT2 slow acetylator status predicts increased hydralazine levels, which may lead to increased efficacy and adverse effects. Caution should be exercised in slow acetylators with total daily hydralazine doses of 200 mg or more. Fast acetylators are at risk for inefficacy at lower doses of hydralazine. With appropriate guidance on the usage of NAT2 genotype, clinicians can adopt a personalized approach to hydralazine dosing and prescription, enabling more efficient and safe treatment of resistant hypertension.
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Anti-Hipertensivos/uso terapêutico , Arilamina N-Acetiltransferase/genética , Hidralazina/uso terapêutico , Hipertensão/tratamento farmacológico , Medicina de Precisão/métodos , Anti-Hipertensivos/farmacocinética , Arilamina N-Acetiltransferase/metabolismo , Relação Dose-Resposta a Droga , Resistência a Medicamentos/genética , Humanos , Hidralazina/farmacocinética , Hipertensão/genética , Nefrologia/métodos , Nefrologia/normas , Testes Farmacogenômicos/normas , Variantes Farmacogenômicos , Guias de Prática Clínica como Assunto , Medicina de Precisão/normas , Resultado do TratamentoRESUMO
Hypertension and chronic kidney disease are inextricably linked. Hypertension is a well-recognized contributor to chronic kidney disease progression and, in turn, renal disease potentiates hypertension. A generalized approach to drug selection and dosage has not proven effective in managing these conditions, in part, because patients with heterogeneous kidney disease and hypertension etiologies are frequently grouped according to functional or severity classifications. Genetic testing may serve as an important tool in the armamentarium of clinicians who embrace precision medicine. Increasing scientific evidence has supported the utilization of genomic information to select efficacious antihypertensive therapy and understand hereditary contributors to chronic kidney disease progression. Given the wide array of antihypertensive agents available and diversity of genetic renal disease predictors, a panel-based approach to genotyping may be an efficient and economic means of establishing an individualized blood pressure response profile for patients with various forms of chronic kidney disease and hypertension. In this manuscript, we discuss the validation process of a Clinical Laboratory Improvement Amendments-approved genetic test to relay information on 72 genetic variants associated with kidney disease progression and hypertension therapy. These genomic-based interventions, in addition to routine clinical data, may help inform physicians to provide personalized therapy.
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Hipertensão/tratamento farmacológico , Variantes Farmacogenômicos , Insuficiência Renal Crônica/tratamento farmacológico , Anti-Hipertensivos/uso terapêutico , Técnicas de Genotipagem , Humanos , Hipertensão/genética , Assistência Centrada no Paciente , Medicina de Precisão , Insuficiência Renal Crônica/genéticaRESUMO
Varicose veins are twisted, dilated veins most commonly located on the lower extremities. The exact pathophysiology is debated, but it involves a genetic predisposition, incompetent valves, weakened vascular walls, and increased intravenous pressure. Risk factors include family history of venous disease; female sex; older age; chronically increased intra-abdominal pressure due to obesity, pregnancy, chronic constipation, or a tumor; and prolonged standing. Symptoms of varicose veins include a heavy, achy feeling and an itching or burning sensation; these symptoms worsen with prolonged standing. Potential complications include infection, leg ulcers, stasis changes, and thrombosis. Conservative treatment options include external compression; lifestyle modifications, such as avoidance of prolonged standing and straining, exercise, wearing nonrestrictive clothing, modification of cardiovascular risk factors, and interventions to reduce peripheral edema; elevation of the affected leg; weight loss; and medical therapy. There is not enough evidence to determine if compression stockings are effective in the treatment of varicose veins in the absence of active or healed venous ulcers. Interventional treatments include external laser thermal ablation, endovenous thermal ablation, endovenous sclerotherapy, and surgery. Although surgery was once the standard of care, it largely has been replaced by endovenous thermal ablation, which can be performed under local anesthesia and may have better outcomes and fewer complications than other treatments. Existing evidence and clinical guidelines suggest that a trial of compression therapy is not warranted before referral for endovenous thermal ablation, although it may be necessary for insurance coverage.
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Varizes/diagnóstico , Varizes/terapia , Humanos , Varizes/etiologiaRESUMO
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a severe neurodegenerative disorder that affects carriers of premutation CGG-repeat expansion alleles of the fragile X mental retardation 1 (FMR1) gene; current evidence supports a causal role of the expanded CGG repeat within the FMR1 mRNA in the pathogenesis of FXTAS. Though the mRNA has been observed to induce cellular toxicity in FXTAS, the mechanisms are unclear. One common neurophysiological characteristic of FXTAS patients is their inability to properly attenuate their response to an auditory stimulus upon receipt of a small pre-stimulus. Therefore, to gain genetic and cell biological insight into FXTAS, we examined the effect of expanded CGG repeats on the plasticity of the olfactory response of the genetically tractable nematode, Caenorhabditis elegans (C. elegans). While C. elegans is innately attracted to odors, this response can be downregulated if the odor is paired with starvation. We found that expressing expanded CGG repeats in olfactory neurons interfered with this plasticity without affecting either the innate odor-seeking response or the olfactory neuronal morphology. Interrogation of three RNA regulatory pathways indicated that the expanded CGG repeats act via the C. elegans microRNA (miRNA)-specific Argonaute ALG-2 to diminish olfactory plasticity. This observation suggests that the miRNA-Argonaute pathway may play a pathogenic role in subverting neuronal function in FXTAS.
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Butanonas/farmacologia , Caenorhabditis elegans/fisiologia , Proteína do X Frágil da Deficiência Intelectual/genética , Neurônios Receptores Olfatórios/metabolismo , Células Receptoras Sensoriais/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas Argonautas/genética , Ataxia/genética , Ataxia/patologia , Caenorhabditis elegans/genética , Modelos Animais de Doenças , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/patologia , Humanos , Plasticidade Neuronal , Olfato , Tremor/genética , Tremor/patologia , Expansão das Repetições de TrinucleotídeosRESUMO
Signaling levels within sensory neurons must be tightly regulated to allow cells to integrate information from multiple signaling inputs and to respond to new stimuli. Herein we report a new role for the cGMP-dependent protein kinase EGL-4 in the negative regulation of G protein-coupled nociceptive chemosensory signaling. C. elegans lacking EGL-4 function are hypersensitive in their behavioral response to low concentrations of the bitter tastant quinine and exhibit an elevated calcium flux in the ASH sensory neurons in response to quinine. We provide the first direct evidence for cGMP/PKG function in ASH and propose that ODR-1, GCY-27, GCY-33 and GCY-34 act in a non-cell-autonomous manner to provide cGMP for EGL-4 function in ASH. Our data suggest that activated EGL-4 dampens quinine sensitivity via phosphorylation and activation of the regulator of G protein signaling (RGS) proteins RGS-2 and RGS-3, which in turn downregulate Gα signaling and behavioral sensitivity.
Assuntos
Comportamento Animal/fisiologia , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Proteínas Quinases Dependentes de GMP Cíclico/genética , GMP Cíclico/metabolismo , Animais , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Fosforilação , Proteínas RGS/genética , Proteínas RGS/metabolismo , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/fisiologia , Transdução de Sinais/genéticaRESUMO
Drosophila melanogaster Polo kinase physically interacts with, and is repressed by, the Matrimony (Mtrm) protein during oogenesis. Females heterozygous for a deletion of the mtrm gene display defects in chromosome segregation at meiosis I. However, a complete absence of Mtrm results in both meiotic catastrophe and female sterility. We show that three phosphorylated residues in an N-terminal region in Mtrm are required for Mtrm::Polo binding. However, this binding is noncanonical; it does not require either a complete S-pS/pT-P motif in Mtrm or key residues in the Polo-box domain of Polo that allow Polo to bind phosphorylated substrates. By using fluorescence cross-correlation spectroscopy to characterize the Mtrm::Polo interaction in vivo, we show that a sterile α-motif (SAM) domain located at the C terminus of Mtrm increases the stability of Mtrm::Polo binding. Although Mtrm's C-terminal SAM domain is not required to rescue the chromosome segregation defects observed in mtrm/+ females, it is essential to prevent both meiotic catastrophe and the female sterility observed in mtrm/mtrm females. We propose that Polo's interaction with the cluster of phosphorylated residues alone is sufficient to rescue the meiosis I defect. However, the strengthening of Mtrm::Polo binding mediated by the SAM domain is necessary to prevent meiotic catastrophe and ensure female fertility. Characterization of the Mtrm::Polo interaction, as well as that of other Polo regulators, may assist in the design of a new class of Polo inhibitors to be used as targeted anticancer therapeutic agents.
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Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Meiose/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Masculino , Fosforilação/fisiologia , Ligação Proteica/fisiologia , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Espectrometria de FluorescênciaRESUMO
There is a need to define regions of gene activation or repression that control human kidney cells in states of health, injury, and repair to understand the molecular pathogenesis of kidney disease and design therapeutic strategies. Comprehensive integration of gene expression with epigenetic features that define regulatory elements remains a significant challenge. We measure dual single nucleus RNA expression and chromatin accessibility, DNA methylation, and H3K27ac, H3K4me1, H3K4me3, and H3K27me3 histone modifications to decipher the chromatin landscape and gene regulation of the kidney in reference and adaptive injury states. We establish a spatially-anchored epigenomic atlas to define the kidney's active, silent, and regulatory accessible chromatin regions across the genome. Using this atlas, we note distinct control of adaptive injury in different epithelial cell types. A proximal tubule cell transcription factor network of ELF3, KLF6, and KLF10 regulates the transition between health and injury, while in thick ascending limb cells this transition is regulated by NR2F1. Further, combined perturbation of ELF3, KLF6, and KLF10 distinguishes two adaptive proximal tubular cell subtypes, one of which manifested a repair trajectory after knockout. This atlas will serve as a foundation to facilitate targeted cell-specific therapeutics by reprogramming gene regulatory networks.
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Cromatina , Rim , Humanos , Cromatina/genética , Túbulos Renais Proximais , Nível de Saúde , Contagem de CélulasRESUMO
An overwhelming body of evidence points to an inextricable link between race and health disparities in the United States. Although race is best understood as a social construct, its role in health outcomes has historically been attributed to increasingly debunked theories of underlying biological and genetic differences across races. Recently, growing calls for health equity and social justice have raised awareness of the impact of implicit bias and structural racism on social determinants of health, healthcare quality, and ultimately, health outcomes. This more nuanced recognition of the role of race in health disparities has, in turn, facilitated introspective racial disparities research, root cause analyses, and changes in practice within the medical community. Examining the complex interplay between race, social determinants of health, and health outcomes allows systems of health to create mechanisms for checks and balances that mitigate unfair and avoidable health inequalities. As one of the specialties most intertwined with social medicine, emergency medicine (EM) is ideally positioned to address racism in medicine, develop health equity metrics, monitor disparities in clinical performance data, identify research gaps, implement processes and policies to eliminate racial health inequities, and promote anti-racist ideals as advocates for structural change. In this critical review our aim was to (a) provide a synopsis of racial disparities across a broad scope of clinical pathology interests addressed in emergency departments-communicable diseases, non-communicable conditions, and injuries-and (b) through a race-conscious analysis, develop EM practice recommendations for advancing a culture of equity with the potential for measurable impact on healthcare quality and health outcomes.
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Medicina de Emergência , Equidade em Saúde , Humanos , Instalações de Saúde , Serviço Hospitalar de Emergência , Lacunas de EvidênciasRESUMO
BACKGROUND: Metabolic outcomes in type 1 diabetes remain suboptimal. Disease modifying therapy to prevent ß-cell loss presents an alternative treatment framework but the effect on metabolic outcomes is unclear. We, therefore, aimed to define the relationship between insulin C-peptide as a marker of ß-cell function and metabolic outcomes in new-onset type 1 diabetes. METHODS: 21 trials of disease-modifying interventions within 100 days of type 1 diabetes diagnosis comprising 1315 adults (ie, those 18 years and older) and 1396 children (ie, those younger than 18 years) were combined. Endpoints assessed were stimulated area under the curve C-peptide, HbA1c, insulin use, hypoglycaemic events, and composite scores (such as insulin dose adjusted A1c, total daily insulin, U/kg per day, and BETA-2 score). Positive studies were defined as those meeting their primary endpoint. Differences in outcomes between active and control groups were assessed using the Wilcoxon rank test. FINDINGS: 6 months after treatment, a 24·8% greater C-peptide preservation in positive studies was associated with a 0·55% lower HbA1c (p<0·0001), with differences being detectable as early as 3 months. Cross-sectional analysis, combining positive and negative studies, was consistent with this proportionality: a 55% improvement in C-peptide preservation was associated with 0·64% lower HbA1c (p<0·0001). Higher initial C-peptide levels and greater preservation were associated with greater improvement in HbA1c. For HbA1c, IDAAC, and BETA-2 score, sample size predictions indicated that 2-3 times as many participants per group would be required to show a difference at 6 months as compared with C-peptide. Detecting a reduction in hypoglycaemia was affected by reporting methods. INTERPRETATION: Interventions that preserve ß-cell function are effective at improving metabolic outcomes in new-onset type 1 diabetes, confirming their potential as adjuncts to insulin. We have shown that improvements in HbA1c are directly proportional to the degree of C-peptide preservation, quantifying this relationship, and supporting the use of C-peptides as a surrogate endpoint in clinical trials. FUNDING: JDRF and Diabetes UK.
Assuntos
Diabetes Mellitus Tipo 1 , Adulto , Criança , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/complicações , Peptídeo C/uso terapêutico , Estudos Transversais , Hemoglobinas Glicadas , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêuticoRESUMO
There is a need to define regions of gene activation or repression that control human kidney cells in states of health, injury, and repair to understand the molecular pathogenesis of kidney disease and design therapeutic strategies. However, comprehensive integration of gene expression with epigenetic features that define regulatory elements remains a significant challenge. We measured dual single nucleus RNA expression and chromatin accessibility, DNA methylation, and H3K27ac, H3K4me1, H3K4me3, and H3K27me3 histone modifications to decipher the chromatin landscape and gene regulation of the kidney in reference and adaptive injury states. We established a comprehensive and spatially-anchored epigenomic atlas to define the kidney's active, silent, and regulatory accessible chromatin regions across the genome. Using this atlas, we noted distinct control of adaptive injury in different epithelial cell types. A proximal tubule cell transcription factor network of ELF3 , KLF6 , and KLF10 regulated the transition between health and injury, while in thick ascending limb cells this transition was regulated by NR2F1 . Further, combined perturbation of ELF3 , KLF6 , and KLF10 distinguished two adaptive proximal tubular cell subtypes, one of which manifested a repair trajectory after knockout. This atlas will serve as a foundation to facilitate targeted cell-specific therapeutics by reprogramming gene regulatory networks.
RESUMO
OBJECTIVES: Virtual rounds enable remote participation in bedside clinical encounters. Their effects on education remain poorly characterized and limited by lack of foundational evidence establishing that this approach is welcomed among learners and educators. We assessed technical feasibility and acceptability of incorporating video conferencing into daily work rounds of pediatric residents and attending physicians. METHODS: We conducted a cross-sectional survey-based study of attending observers and pediatric residents participating in rounds both at the bedside and via video teleconferencing from September to December 2020. Participant experiences were assessed and summarized using parametric Likert-type questions regarding technical issues, efficiency, educational experience, and engagement. Associations between technical aspects and individual perceptions of virtual rounds and self-reported engagement were also measured. RESULTS: Of 75 encounters, 29% experienced technical issues, 45% of which were attributable to a low-quality tablet stand. Negative impacts of virtual rounding on efficiency were reported in 6% of responses. Virtual participants were engaged (70%) and reported educational value for 65% of encounters. Comfort with virtually asking questions (odds ratio 3.3; 95% confidence interval 2.0-5.7) and performing clinical tasks for other patients (odds ratio 0.42; 95% confidence interval 0.2-0.9) were associated with engagement (P <.05). CONCLUSIONS: Virtual participation in rounds was technically feasible and maintained educational value and engagement for residents in the majority of encounters, without sacrificing efficiency. Even as restrictions from the coronavirus disease 2019 pandemic are lifted, this rounding model has many important applications, including increasing educational opportunities for remote learners and making multidisciplinary rounds more accessible.
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COVID-19 , Visitas de Preceptoria , Humanos , Criança , Pacientes Internados , Estudos Transversais , Estudos de Viabilidade , COVID-19/epidemiologiaRESUMO
Diabetic kidney disease (DKD) remains the leading cause of end-stage kidney disease despite decades of study. Alterations in the glomerulus and kidney tubules both contribute to the pathogenesis of DKD although the majority of investigative efforts have focused on the glomerulus. We sought to examine the differential expression signature of human DKD in the glomerulus and proximal tubule and corroborate our findings in the db/db mouse model of diabetes. A transcriptogram network analysis of RNAseq data from laser microdissected (LMD) human glomerulus and proximal tubule of DKD and reference nephrectomy samples revealed enriched pathways including rhodopsin-like receptors, olfactory signaling, and ribosome (protein translation) in the proximal tubule of human DKD biopsy samples. The translation pathway was also enriched in the glomerulus. Increased translation in diabetic kidneys was validated using polyribosomal profiling in the db/db mouse model of diabetes. Using single nuclear RNA sequencing (snRNAseq) of kidneys from db/db mice, we prioritized additional pathways identified in human DKD. The top overlapping pathway identified in the murine snRNAseq proximal tubule clusters and the human LMD proximal tubule compartment was carboxylic acid catabolism. Using ultra-performance liquid chromatography-mass spectrometry, the fatty acid catabolism pathway was also found to be dysregulated in the db/db mouse model. The Acetyl-CoA metabolite was down-regulated in db/db mice, aligning with the human differential expression of the genes ACOX1 and ACACB. In summary, our findings demonstrate that proximal tubular alterations in protein translation and carboxylic acid catabolism are key features in both human and murine DKD.