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1.
Nature ; 622(7981): 58-62, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37794268

RESUMEN

In physics, two systems that radically differ at short scales can exhibit strikingly similar macroscopic behaviour: they are part of the same long-distance universality class1. Here we apply this viewpoint to geometry and initiate a program of classifying homogeneous metrics on group manifolds2 by their long-distance properties. We show that many metrics on low-dimensional Lie groups have markedly different short-distance properties but nearly identical distance functions at long distances, and provide evidence that this phenomenon is even more robust in high dimensions. An application of these ideas of particular interest to physics and computer science is complexity geometry3-7-the study of quantum computational complexity using Riemannian geometry. We argue for the existence of a large universality class of definitions of quantum complexity, each linearly related to the other, a much finer-grained equivalence than typically considered. We conjecture that a new effective metric emerges at larger complexities that describes a broad class of complexity geometries, insensitive to various choices of microscopic penalty factors. We discuss the implications for recent conjectures in quantum gravity.

2.
Nature ; 581(7809): 444-451, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32461652

RESUMEN

Structural variants (SVs) rearrange large segments of DNA1 and can have profound consequences in evolution and human disease2,3. As national biobanks, disease-association studies, and clinical genetic testing have grown increasingly reliant on genome sequencing, population references such as the Genome Aggregation Database (gnomAD)4 have become integral in the interpretation of single-nucleotide variants (SNVs)5. However, there are no reference maps of SVs from high-coverage genome sequencing comparable to those for SNVs. Here we present a reference of sequence-resolved SVs constructed from 14,891 genomes across diverse global populations (54% non-European) in gnomAD. We discovered a rich and complex landscape of 433,371 SVs, from which we estimate that SVs are responsible for 25-29% of all rare protein-truncating events per genome. We found strong correlations between natural selection against damaging SNVs and rare SVs that disrupt or duplicate protein-coding sequence, which suggests that genes that are highly intolerant to loss-of-function are also sensitive to increased dosage6. We also uncovered modest selection against noncoding SVs in cis-regulatory elements, although selection against protein-truncating SVs was stronger than all noncoding effects. Finally, we identified very large (over one megabase), rare SVs in 3.9% of samples, and estimate that 0.13% of individuals may carry an SV that meets the existing criteria for clinically important incidental findings7. This SV resource is freely distributed via the gnomAD browser8 and will have broad utility in population genetics, disease-association studies, and diagnostic screening.


Asunto(s)
Enfermedad/genética , Variación Genética , Genética Médica/normas , Genética de Población/normas , Genoma Humano/genética , Femenino , Pruebas Genéticas , Técnicas de Genotipaje , Humanos , Masculino , Persona de Mediana Edad , Mutación , Polimorfismo de Nucleótido Simple/genética , Grupos Raciales/genética , Estándares de Referencia , Selección Genética , Secuenciación Completa del Genoma
3.
Hepatology ; 79(6): 1279-1292, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38146932

RESUMEN

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study. APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings. CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.


Asunto(s)
Síndrome de Alagille , Humanos , Síndrome de Alagille/complicaciones , Síndrome de Alagille/tratamiento farmacológico , Femenino , Masculino , Estudios Retrospectivos , Niño , Lactante , Preescolar , Supervivencia sin Progresión , Adolescente , Proteínas Portadoras , Glicoproteínas de Membrana
4.
Mov Disord ; 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38817039

RESUMEN

Cerebrovascular activity is not only crucial to optimal cerebral perfusion, but also plays an important role in the glymphatic clearance of interstitial waste, including α-synuclein. This highlights a need to evaluate how cerebrovascular activity is altered in Lewy body diseases. This review begins by discussing how vascular risk factors and cardiovascular autonomic dysfunction may serve as upstream or direct influences on cerebrovascular activity. We then discuss how patients with Lewy body disease exhibit reduced and delayed cerebrovascular activity, hypoperfusion, and reductions in measures used to capture cerebrospinal fluid flow, suggestive of a reduced capacity for glymphatic clearance. Given the lack of an existing framework, we propose a model by which these processes may foster α-synuclein aggregation and neuroinflammation. Importantly, this review highlights several avenues for future research that may lead to treatments early in the disease course, prior to neurodegeneration. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

5.
Biotechnol Bioeng ; 121(5): 1674-1687, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38372655

RESUMEN

Hollow fiber filter fouling is a common issue plaguing perfusion production process for biologics therapeutics, but the nature of filter foulant has been elusive. Here we studied cell culture materials especially Chinese hamster ovary (CHO) cell-derived extracellular vesicles in perfusion process to determine their role in filter fouling. We found that the decrease of CHO-derived small extracellular vesicles (sEVs) with 50-200 nm in diameter in perfusion permeates always preceded the increase in transmembrane pressure (TMP) and subsequent decrease in product sieving, suggesting that sEVs might have been retained inside filters and contributed to filter fouling. Using scanning electron microscopy and helium ion microscopy, we found sEV-like structures in pores and on foulant patches of hollow fiber tangential flow filtration filter (HF-TFF) membranes. We also observed that the Day 28 TMP of perfusion culture correlated positively with the percentage of foulant patch areas. In addition, energy dispersive X-ray spectroscopy-based elemental mapping microscopy and spectroscopy analysis suggests that foulant patches had enriched cellular materials but not antifoam. Fluorescent staining results further indicate that these cellular materials could be DNA, proteins, and even adherent CHO cells. Lastly, in a small-scale HF-TFF model, addition of CHO-specific sEVs in CHO culture simulated filter fouling behaviors in a concentration-dependent manner. Based on these results, we proposed a mechanism of HF-TFF fouling, in which filter pore constriction by CHO sEVs is followed by cake formation of cellular materials on filter membrane.


Asunto(s)
Anticuerpos Monoclonales , Filtración , Cricetinae , Animales , Cricetulus , Células CHO , Perfusión , Filtración/métodos , Reactores Biológicos , Membranas Artificiales
6.
J Pediatr Gastroenterol Nutr ; 78(3): 548-554, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38504404

RESUMEN

OBJECTIVES: Abdominal pain remains one of the most common referral reasons to pediatric gastroenterology. Dietary intolerances are often considered but due to various factors are hardly pursued. We observed that diet review in large number of children with abdominal pain was high in sugary foods which led to food intolerance investigation and dietary intervention. METHODS: A retrospective review was conducted of patients presenting with abdominal pain, diarrhea, or vomiting and negative GI evaluation, who underwent fructose breath testing. Patients younger than 20 years old who were seen between June 1, 2018 and March 1, 2021 were included. Statistical analysis was performed in R. RESULTS: There were 110 pediatric patients during the study period who underwent fructose breath testing, with 31% male and 69% female. The average age was 12.14 ± 4.01 years, and the average BMI was 21.21 ± 6.12. Abdominal pain was the most common presenting symptom (74.5%) followed by diarrhea and vomiting. Seventy-seven patients (70%) had a positive fructose breath test and were diagnosed with dietary intolerance to fructose. The 56 (67.5%) of those patients experienced symptoms during the breath test. Forty-three patients improved with dietary intervention. Twenty-seven on low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet and 16 on other diets. CONCLUSIONS: Based on analysis of our cohort of children with abdominal pain and high incidence of fructose intolerance as well as improvement in symptoms, following dietary changes, this condition should be considered and treated. Further investigation is needed to improve diagnostic testing but also into understanding mechanisms behind symptom presentation in this population.


Asunto(s)
Intolerancia a la Fructosa , Síndrome del Colon Irritable , Polímeros , Humanos , Masculino , Femenino , Niño , Adolescente , Adulto Joven , Adulto , Disacáridos , Intolerancia a la Fructosa/diagnóstico , Intolerancia a la Fructosa/terapia , Intolerancia a la Fructosa/complicaciones , Monosacáridos , Síndrome del Colon Irritable/complicaciones , Dieta , Oligosacáridos , Dolor Abdominal/complicaciones , Diarrea/etiología , Fructosa , Vómitos/complicaciones , Fermentación
7.
Pattern Recognit ; 1522024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38645435

RESUMEN

Deep learning models for medical image segmentation are usually trained with voxel-wise losses, e.g., cross-entropy loss, focusing on unary supervision without considering inter-voxel relationships. This oversight potentially leads to semantically inconsistent predictions. Here, we propose a contextual similarity loss (CSL) and a structural similarity loss (SSL) to explicitly and efficiently incorporate inter-voxel relationships for improved performance. The CSL promotes consistency in predicted object categories for each image sub-region compared to ground truth. The SSL enforces compatibility between the predictions of voxel pairs by computing pair-wise distances between them, ensuring that voxels of the same class are close together whereas those from different classes are separated by a wide margin in the distribution space. The effectiveness of the CSL and SSL is evaluated using a clinical cone-beam computed tomography (CBCT) dataset of patients with various craniomaxillofacial (CMF) deformities and a public pancreas dataset. Experimental results show that the CSL and SSL outperform state-of-the-art regional loss functions in preserving segmentation semantics.

8.
Circulation ; 145(20): 1524-1533, 2022 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-35389749

RESUMEN

BACKGROUND: Rare sequence variation in genes underlying cardiac repolarization and common polygenic variation influence QT interval duration. However, current clinical genetic testing of individuals with unexplained QT prolongation is restricted to examination of monogenic rare variants. The recent emergence of large-scale biorepositories with sequence data enables examination of the joint contribution of rare and common variations to the QT interval in the population. METHODS: We performed a genome-wide association study of the QTc in 84 630 UK Biobank participants and created a polygenic risk score (PRS). Among 26 976 participants with whole-genome sequencing and ECG data in the TOPMed (Trans-Omics for Precision Medicine) program, we identified 160 carriers of putative pathogenic rare variants in 10 genes known to be associated with the QT interval. We examined QTc associations with the PRS and with rare variants in TOPMed. RESULTS: Fifty-four independent loci were identified by genome-wide association study in the UK Biobank. Twenty-one loci were novel, of which 12 were replicated in TOPMed. The PRS composed of 1 110 494 common variants was significantly associated with the QTc in TOPMed (ΔQTc/decile of PRS=1.4 ms [95% CI, 1.3 to 1.5]; P=1.1×10-196). Carriers of putative pathogenic rare variants had longer QTc than noncarriers (ΔQTc=10.9 ms [95% CI, 7.4 to 14.4]). Of individuals with QTc>480 ms, 23.7% carried either a monogenic rare variant or had a PRS in the top decile (3.4% monogenic, 21% top decile of PRS). CONCLUSIONS: QTc duration in the population is influenced by both rare variants in genes underlying cardiac repolarization and polygenic risk, with a sizeable contribution from polygenic risk. Comprehensive assessment of the genetic determinants of QTc prolongation includes incorporation of both polygenic and monogenic risk.


Asunto(s)
Estudio de Asociación del Genoma Completo , Síndrome de QT Prolongado , Electrocardiografía , Heterocigoto , Humanos , Síndrome de QT Prolongado/diagnóstico , Síndrome de QT Prolongado/genética , Herencia Multifactorial , Secuenciación Completa del Genoma
9.
Mov Disord ; 38(7): 1262-1272, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37157056

RESUMEN

BACKGROUND: Cerebrovascular dysfunction in Parkinson's disease (PD) is heterogeneous and may contribute to disease pathophysiology or progression. There is a need to understand the mechanisms by which cerebrovascular dysfunction is altered in participants with PD. OBJECTIVES: The objective of this study is to test the hypothesis that participants with PD exhibit a significant reduction in the ability of the cerebral vessels to dilate in response to vasoactive challenges relative to healthy controls (HC). METHODS: The current study uses a vasodilatory challenge while participants undergo functional magnetic resonance imaging to quantify the amplitude and delay of cerebrovascular reactivity in participants with PD relative to age and sex-matched HC. An analysis of covariance was used to evaluate differences in cerebrovascular reactivity amplitude and latency between PD participants and HC. RESULTS: A significant main effect of group was observed for whole-brain cerebrovascular reactivity amplitude (F(1, 28) = 4.38, p = 0.046, Hedge's g = 0.73) and latency (F(1, 28) = 16.35, p < 0.001, Hedge's g = 1.42). Participants with PD exhibited reduced whole-brain amplitude and increased latencies in cerebrovascular reactivity relative to HC. The evaluation of regional effects indicates that the largest effects were observed in the cuneus, precuneus, and parietal regions. CONCLUSIONS: PD participants exhibited reduced and delayed cerebrovascular reactivity. This dysfunction may play an important role in chronic hypoxia, neuroinflammation, and protein aggregation, mechanisms that could lead to disease progression. Cerebrovascular reactivity may serve as an important biomarker and target for future interventions. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Enfermedad de Parkinson , Humanos , Encéfalo/patología , Imagen por Resonancia Magnética/métodos , Lóbulo Occipital , Lóbulo Parietal
10.
Dig Dis Sci ; 68(4): 1253-1259, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36323965

RESUMEN

Hydrogen gas (H2) is produced by H2-producing microbes in the gut during polysaccharide fermentation. Gut microbiome also includes H2-consuming microbes utilizing H2 for metabolism: methanogens producing methane, CH4, and sulfate-reducing bacteria producing hydrogen sulfide, H2S. H2S is not measured in the evaluation of gaseous byproducts of microbial fermentation. We hypothesize that the availability of measured H2 depends on both hydrogen producers and hydrogen consumers by measuring H2 in vitro and in vivo. In the in vitro study, groups were Bacteroides thetaiotaomicron (B. theta, H2 producers), Desulfovibrio vulgaris (D. vulgaris, H2 consumers), and D. vulgaris + B. theta combined. Gas samples were collected at 2 h and 24 h after incubation and assayed for H2, CH4, and H2S. In the in vivo study Sprague-Dawley rats were gavaged with suspended bacteria in four groups: B. theta, D. vulgaris, combined, and control. Gas was analyzed for H2 at 60 min. In the in vitro experiment, H2 concentration was higher in the combined group (188 ± 93.3 ppm) compared with D. vulgaris (27.17 ± 9.6 ppm) and B. theta groups (34.2 ± 29.8 ppm; P < 0.05); H2S concentration was statistically higher in the combined group (10.32 ± 1.5 ppm) compared with B. theta (0.19 ± 0.03 ppm) and D. vulgaris group (3.46 ± 0.28 ppm; P < 0.05). In the in vivo study, H2 concentrations were significantly higher in the B. theta group (44.3 ± 6.0 ppm) compared with control (31.8 ± 4.3) and the combined group (34.2 ± 8.7, P < 0.05). This study shows that sulfate-reducing bacteria could convert available H2 to H2S, leading to measured hydrogen levels that are dependent on the actions of both H2 producers and H2 consumers.


Asunto(s)
Desulfovibrio , Hidrógeno , Animales , Ratas , Ratas Sprague-Dawley , Bacterias , Metano , Sulfatos
11.
BMC Pediatr ; 23(1): 189, 2023 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-37085783

RESUMEN

BACKGROUND: Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive DNA repair disorder that increases risk of hematological malignancy. Primary gastric malignancies are exceedingly rare in pediatric patients and not typically high on the differential of abdominal pain. CASE PRESENTATION: A 14-year-old male with NBS presented with persistent abdominal pain and was diagnosed with primary Hodgkin disease of the stomach. CONCLUSIONS: In pediatric patients with predisposition to malignancies, such as those with underlying chromosome instability disorders, all symptoms must be carefully considered.


Asunto(s)
Enfermedad de Hodgkin , Síndrome de Nijmegen , Masculino , Humanos , Niño , Adolescente , Síndrome de Nijmegen/complicaciones , Síndrome de Nijmegen/diagnóstico , Síndrome de Nijmegen/genética , Enfermedad de Hodgkin/complicaciones , Enfermedad de Hodgkin/diagnóstico , Genotipo
12.
Nature ; 537(7619): 185-190, 2016 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-27533032

RESUMEN

Morphine is an alkaloid from the opium poppy used to treat pain. The potentially lethal side effects of morphine and related opioids-which include fatal respiratory depression-are thought to be mediated by µ-opioid-receptor (µOR) signalling through the ß-arrestin pathway or by actions at other receptors. Conversely, G-protein µOR signalling is thought to confer analgesia. Here we computationally dock over 3 million molecules against the µOR structure and identify new scaffolds unrelated to known opioids. Structure-based optimization yields PZM21-a potent Gi activator with exceptional selectivity for µOR and minimal ß-arrestin-2 recruitment. Unlike morphine, PZM21 is more efficacious for the affective component of analgesia versus the reflexive component and is devoid of both respiratory depression and morphine-like reinforcing activity in mice at equi-analgesic doses. PZM21 thus serves as both a probe to disentangle µOR signalling and a therapeutic lead that is devoid of many of the side effects of current opioids.


Asunto(s)
Analgésicos Opioides/efectos adversos , Analgésicos Opioides/química , Descubrimiento de Drogas , Receptores Opioides mu/agonistas , Tiofenos/química , Tiofenos/farmacología , Urea/análogos & derivados , Analgesia/métodos , Analgésicos Opioides/farmacología , Animales , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Simulación del Acoplamiento Molecular , Dolor/tratamiento farmacológico , Receptores Opioides mu/deficiencia , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Compuestos de Espiro/farmacología , Relación Estructura-Actividad , Tiofenos/efectos adversos , Urea/efectos adversos , Urea/química , Urea/farmacología
14.
Retina ; 42(6): 1047-1056, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35067607

RESUMEN

PURPOSE: To investigate the utility of optical coherence tomography angiography (OCTA) for the detection of inflammatory choroidal neovascularization (iCNV) and monitoring their response to treatment. METHODS: A retrospective review of patients with a diagnosis of uveitis and associated iCNV with active exudation was performed. Active iCNV was determined by spectral domain OCT and/or fluorescein angiogram. Spectral domain OCTA outer retina to choriocapillaris slabs was evaluated for the presence of iCNV. Follow-up OCTA images were qualitatively assessed to determine whether regression of iCNV occurred after treatment. RESULTS: Thirteen eyes of 12 patients were included. The etiologies of uveitis include punctate inner choroidopathy (n = 4), multifocal choroiditis (n = 2), presumed sarcoid uveitis (n = 2), tuberculous choroiditis (n = 1), birdshot chorioretinopathy (n = 1), syphilitic uveitis (n = 1), serpiginous choroiditis (n = 1), and idiopathic panuveitis (n = 1). Inflammatory choroidal neovascularization was detected on en face OCTA in 10 of 13 eyes (76.9%). After iCNV treatment, en face OCTA demonstrated complete regression of iCNV in 5 of 10 eyes (50%), partial regression in 2 of 10 eyes (20%), and no regression in 3 of 10 eyes (30%). CONCLUSIONS: Optical coherence tomography angiography is an effective modality for detecting iCNV and could provide detailed visualization regarding location, morphologic structure, and flow of the iCNV and its response to therapy.


Asunto(s)
Neovascularización Coroidal , Coroides , Neovascularización Coroidal/diagnóstico , Neovascularización Coroidal/etiología , Angiografía con Fluoresceína/métodos , Humanos , Tomografía de Coherencia Óptica/métodos , Agudeza Visual
15.
Biochem J ; 478(17): 3185-3204, 2021 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-34405853

RESUMEN

p97 protein is a highly conserved, abundant, functionally diverse, structurally dynamic homohexameric AAA enzyme-containing N, D1, and D2 domains. A truncated p97 protein containing the N and D1 domains and the D1-D2 linker (ND1L) exhibits 79% of wild-type (WT) ATPase activity whereas the ND1 domain alone without the linker only has 2% of WT activity. To investigate the relationship between the D1-D2 linker and the D1 domain, we produced p97 ND1L mutants and demonstrated that this 22-residue linker region is essential for D1 ATPase activity. The conserved amino acid leucine 464 (L464) is critical for regulating D1 and D2 ATPase activity by p97 cofactors p37, p47, and Npl4-Ufd1 (NU). Changing leucine to alanine, proline, or glutamate increased the maximum rate of ATP turnover (kcat) of p47-regulated ATPase activities for these mutants, but not for WT. p37 and p47 increased the kcat of the proline substituted linker, suggesting that they induced linker conformations facilitating ATP hydrolysis. NU inhibited D1 ATPase activities of WT and mutant ND1L proteins, but activated D2 ATPase activity of full-length p97. To further understand the mutant mechanism, we used single-particle cryo-EM to visualize the full-length p97L464P and revealed the conformational change of the D1-D2 linker, resulting in a movement of the helix-turn-helix motif (543-569). Taken together with the biochemical and structural results we conclude that the linker helps maintain D1 in a competent conformation and relays the communication to/from the N-domain to the D1 and D2 ATPase domains, which are ∼50 Šaway.


Asunto(s)
Leucina/metabolismo , Dominios Proteicos/genética , Transducción de Señal/genética , Proteína que Contiene Valosina/química , Proteína que Contiene Valosina/metabolismo , Secuencia de Aminoácidos , Sitios de Unión/genética , Activación Enzimática/genética , Células HeLa , Secuencias Hélice-Giro-Hélice/genética , Humanos , Hidrólisis , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutación , Unión Proteica/genética , Transfección , Proteína que Contiene Valosina/genética
16.
Anaerobe ; 75: 102582, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35533828

RESUMEN

Desulfovibrio spp. is a commensal sulfate reducing bacterium that is present in small numbers in the gastrointestinal tract. Increased concentrations of Desulfovibrio spp. (blooms) have been reported in patients with inflammatory bowel disease and irritable bowel syndrome. Since stress has been reported to exacerbate symptoms of these chronic diseases, this study examined whether the stress catecholamine norepinephrine (NE) promotes Desulfovibrio growth. Norepinephrine-stimulated growth has been reported in other bacterial taxa, and this effect may depend on the availability of the micronutrient iron. OBJECTIVES: This study tested whether norepinephrine exposure affects the in vitro growth of Desulfovibrio vulgaris in an iron dependent manner. METHODS: DSV was incubated in a growth medium with and without 1 µm of norepinephrine. An additional growth assay added the iron chelator deferoxamine in NE exposed DSV. Iron regulatory genes were assessed with and without the treatment of NE and Deferoxamine. RESULTS: We found that norepinephrine significantly increased growth of D. vulgaris. Norepinephrine also increased bacterial production of hydrogen sulfide. Additionally, norepinephrine significantly increased bacterial expression in three of the four tested iron regulatory genes. The iron chelator deferoxamine inhibited growth of D. vulgaris in a dose-dependent manner and reversed the effect of norepinephrine on proliferation of D. vulgaris and on bacterial expression of iron regulatory genes. CONCLUSION: The data presented in this work suggests that promotion of D. vulgaris growth by norepinephrine is iron dependent.


Asunto(s)
Desulfovibrio vulgaris , Desulfovibrio , Deferoxamina/metabolismo , Deferoxamina/farmacología , Desulfovibrio/metabolismo , Desulfovibrio vulgaris/genética , Humanos , Hierro/metabolismo , Quelantes del Hierro/metabolismo , Quelantes del Hierro/farmacología , Norepinefrina/metabolismo , Norepinefrina/farmacología
17.
Am J Hum Genet ; 103(2): 245-260, 2018 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-30057031

RESUMEN

Interferon regulatory factor 2 binding protein-like (IRF2BPL) encodes a member of the IRF2BP family of transcriptional regulators. Currently the biological function of this gene is obscure, and the gene has not been associated with a Mendelian disease. Here we describe seven individuals who carry damaging heterozygous variants in IRF2BPL and are affected with neurological symptoms. Five individuals who carry IRF2BPL nonsense variants resulting in a premature stop codon display severe neurodevelopmental regression, hypotonia, progressive ataxia, seizures, and a lack of coordination. Two additional individuals, both with missense variants, display global developmental delay and seizures and a relatively milder phenotype than those with nonsense alleles. The IRF2BPL bioinformatics signature based on population genomics is consistent with a gene that is intolerant to variation. We show that the fruit-fly IRF2BPL ortholog, called pits (protein interacting with Ttk69 and Sin3A), is broadly detected, including in the nervous system. Complete loss of pits is lethal early in development, whereas partial knockdown with RNA interference in neurons leads to neurodegeneration, revealing a requirement for this gene in proper neuronal function and maintenance. The identified IRF2BPL nonsense variants behave as severe loss-of-function alleles in this model organism, and ectopic expression of the missense variants leads to a range of phenotypes. Taken together, our results show that IRF2BPL and pits are required in the nervous system in humans and flies, and their loss leads to a range of neurological phenotypes in both species.

18.
J Pediatr Hematol Oncol ; 43(7): 254-257, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33181587

RESUMEN

OBJECTIVE: Hepatic and biliary tract diseases are common in sickle cell disease (SCD) patients, likely due to sickling, hemosiderosis, viral hepatitis, or cholelithiasis. Literature is lacking on associations between SCD, autoimmune hepatitis (AIH), and/or sclerosing cholangitis (SC)-together, autoimmune liver disease (AILD). We aimed to better understand the relationship of these diseases in pediatric patients. MATERIALS AND METHODS: A retrospective analysis of patients with SCD and AILD at the Children's Hospital of Philadelphia (January 2008 to August 2015). RESULTS: Seven patients, ages 8 to 23 years (3 males), were identified. Three had AIH, 2 SC, and 2 AIH/SC overlap, known as autoimmune SC. All patients with AIH treated with azathioprine significantly improved their liver enzymes. One patient with SC and inflammatory bowel disease underwent successful bone marrow transplant. Two SC patients died from SCD complications. CONCLUSIONS: In this cohort, there seems to be an association between SCD and AILD; SC in this population was severe. Physicians should be aware of this and evaluate patients with SCD and elevated liver enzymes for AILD.


Asunto(s)
Anemia de Células Falciformes/complicaciones , Eritrocitos Anormales/patología , Hepatitis Autoinmune/patología , Adolescente , Adulto , Niño , Femenino , Estudios de Seguimiento , Hepatitis Autoinmune/etiología , Humanos , Masculino , Pronóstico , Estudios Retrospectivos , Adulto Joven
19.
Dig Dis Sci ; 66(8): 2661-2668, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-32918175

RESUMEN

Hydrogen sulfide (H2S) is a recently discerned endogenous signaling molecule that modulates the vascular system. Endogenous hydrogen sulfide has been shown to dilate both the mesenteric and portal vasculature. Gut microbiome, via sulfur reducing bacteria, is another source of H2S production within the gut lumen; this source of H2S is primarily produced and detoxified in the colon under physiologic conditions. Nitric oxide (NO), a major endogenous vasodilator in the portal circulation, participates in H2S-induced vasodilation in some vascular beds. We hypothesize that jejunal but not colonic H2S increases portal vein flow in a NO-dependent fashion. To evaluate the effects of luminal H2S, venous blood flow, portal venous pressure, and systemic venous pressure were measured in rats after administration of either vehicle or an H2S donor (NaHS) into the jejunum or the colon. We found that portal venous pressure and systemic pressure did not change and were similar between the three study groups. However, portal venous blood flow significantly increased following jejunal administration of NaHS but not in response to colonic NaHS or vehicle administration. To test the contribution of NO production to this response, another group of animals was treated with either an NO synthase inhibitor (N-Ω-nitro-L-arginine, L-NNA) or saline prior to jejunal NaHS infusion. After L-NNA pretreatment, NaHS caused a significant fall rather than increase in portal venous flow compared to saline pretreatment. These data demonstrate that H2S within the small intestine significantly increases portal venous blood flow in a NO-dependent fashion.


Asunto(s)
Colon/metabolismo , Sulfuro de Hidrógeno/farmacología , Yeyuno/metabolismo , Óxido Nítrico/metabolismo , Vena Porta/fisiología , Animales , Colon/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Sulfuro de Hidrógeno/administración & dosificación , Yeyuno/efectos de los fármacos , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa/metabolismo , Nitroarginina/farmacología , Ratas , Ratas Sprague-Dawley
20.
J Pediatr Nurs ; 60: 223-229, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34280734

RESUMEN

PURPOSE: The rising prevalence of IBD in children corresponds with a need for patient education on transition to adult care. The objective of this study was to design, implement and evaluate a novel transitions program for adolescents with Inflammatory Bowel Disease and their parents, and to assess the impact of this program on transition readiness skills, self-efficacy and participant satisfaction. DESIGN AND METHODS: Sixteen adolescent-parent dyads participated in the virtual transition workshop. Workshop programming was designed utilizing a biopsychosocial and multidisciplinary approach to IBD management and engagement with healthcare resources. The impact of the workshop was measured utilizing validated self- and parent-report measures of transition readiness (TRAQ), self-efficacy (IBD-SES), depression (PHQ8) and anxiety (GAD7). RESULTS: Over 60% of participants found the workshop helpful and 92% would recommend it to other teens with IBD. The average adolescent transition readiness score (TRAQ) significantly increased by 5.00 points following the workshop (SD = 7.49, p = 0.04), while total parent scores increased by 10.55 points (SD = 11.15, p = 0.011). As was expected, this demonstrates increased transition readiness skills. The average total adolescent IBD-SES score decreased by 6.75 (SD = 8.95, p = 0.024). CONCLUSION: This novel transition program resulted in increased participant transition readiness, as reported by adolescent and parents, indicating the workshop's utility in promoting tangible skill development. Self-efficacy scores did not increase; self-efficacy is a delayed measure of program success and is tied to disease status and other stressors which also changed across time points. PRACTICE IMPLICATIONS: Future directions include continuing the virtual program for increased participation and dissemination, integrating feedback and increasing interdisciplinary involvement.


Asunto(s)
Enfermedades Inflamatorias del Intestino , Transición a la Atención de Adultos , Adolescente , Adulto , Ansiedad , Trastornos de Ansiedad , Niño , Humanos , Enfermedades Inflamatorias del Intestino/terapia , Padres , Autoeficacia
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