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1.
Inorg Chem ; 63(19): 8664-8673, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38696593

RESUMEN

C2 hydrocarbon separation from methane represents a technological challenge for natural gas upgrading. Herein, we report a new metal-organic framework, [Cu2L(DEF)2]·2DEF (UNT-14; H4L = 4,4',4″,4‴-((1E,1'E,1″E,1‴E)-benzene-1,2,4,5-tetrayltetrakis(ethene-2,1-diyl))tetrabenzoic acid; DEF = N,N-diethylformamide; UNT = University of North Texas). The linker design will potentially increase the surface area and adsorption energy owing to π(hydrocarbon)-π(linker)/M interactions, hence increasing C2 hydrocarbon/CH4 separation. Crystallographic data unravel an sql topology for UNT-14, whereby [Cu2(COO)4]···[L]4- paddle-wheel units afford two-dimensional porous sheets. Activated UNT-14a exhibits moderate porosity with an experimental Brunauer-Emmett-Teller (BET) surface area of 480 m2 g-1 (vs 1868 m2 g-1 from the crystallographic data). UNT-14a exhibits considerable C2 uptake capacity under ambient conditions vs CH4. GCMC simulations reveal higher isosteric heats of adsorption (Qst) and Henry's coefficients (KH) for UNT-14a vs related literature MOFs. Ideal adsorbed solution theory yields favorable adsorption selectivity of UNT-14a for equimolar C2Hn/CH4 gas mixtures, attaining 31.1, 11.9, and 14.8 for equimolar mixtures of C2H6/CH4, C2H4/CH4, and C2H2/CH4, respectively, manifesting efficient C2 hydrocarbon/CH4 separation. The highest C2 uptake and Qst being for ethane are also desirable technologically; it is attributed to the greatest number of "agostic" or other dispersion C-H bond interactions (6) vs 4/2/4 for ethylene/acetylene/methane.

2.
Intern Med J ; 54(8): 1409-1413, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39016076

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease. Global Burden of Disease (GBD) data from 1990 to 2019 reported a rise in prevalence (9-13%) in Australia, which also ranked third highest for NAFLD prevalence compared to 14 similar countries. As a result of underdiagnosis, NAFLD burden is underestimated by GBD.


Asunto(s)
Carga Global de Enfermedades , Enfermedad del Hígado Graso no Alcohólico , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Humanos , Australia/epidemiología , Prevalencia , Masculino , Femenino , Costo de Enfermedad , Persona de Mediana Edad , Adulto
3.
BMC Public Health ; 24(1): 1848, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38992680

RESUMEN

BACKGROUND: The ongoing global crisis of Higher Education (HE) institutions during the post-COVID-19 pandemic period has increased the likelihood of enduring psychological stressors for staff. This study aimed to identify factors associated with job insecurity, burnout, psychological distress and coping amongst staff working at HE institutions globally. METHODS: An anonymous cross-sectional study was conducted in 2023 with staff at HE institutions across 16 countries. Job insecurity was measured using the Job Insecurity Scale (JIS), burnout using the Perceived Burnout measure question, psychological distress using the Kessler Psychological Distress Scale (K10), and coping using the Brief Resilient Coping Scale. Multivariable logistic regression with a stepwise variable selection method was used to identify associations. RESULTS: A total of 2,353 staff participated; the mean age (± SD) was 43(± 10) years and 61% were females. Most staff (85%) did not feel job insecurity, one-third (29%) perceived burnout in their jobs, more than two-thirds (73%) experienced moderate to very high levels of psychological distress, and more than half (58%) exhibited medium to high resilient coping. Perceived job insecurity was associated with staff working part-time [Adjusted Odds Ratio 1.53 (95% Confidence Intervals 1.15-2.02)], having an academic appointment [2.45 (1.78-3.27)], having multiple co-morbidities [1.86 (1.41-2.48)], perceived burnout [1.99 (1.54-2.56)] and moderate to very high level of psychological distress [1.68 (1.18-2.39)]. Perceived burnout was associated with being female [1.35 (1.12-1.63)], having multiple co-morbidities [1.53 (1.20-1.97)], perceived job insecurity [1.99 (1.55-2.57)], and moderate to very high levels of psychological distress [3.23 (2.42-4.30)]. Staff with multiple co-morbidities [1.46 (1.11-1.92)], mental health issues [2.73 (1.79-4.15)], perceived job insecurity [1.61 (1.13-2.30)], and perceived burnout [3.22 (2.41-4.31)] were associated with moderate to very high levels of psychological distress. Staff who perceived their mental health as good to excellent [3.36 (2.69-4.19)] were more likely to have medium to high resilient coping. CONCLUSIONS: Factors identified in this study should be considered in reviewing and updating current support strategies for staff at HE institutions across all countries to reduce stress and burnout and improve wellbeing.


Asunto(s)
Adaptación Psicológica , Agotamiento Profesional , COVID-19 , Humanos , Estudios Transversales , COVID-19/epidemiología , COVID-19/psicología , Masculino , Femenino , Adulto , Agotamiento Profesional/epidemiología , Agotamiento Profesional/psicología , Persona de Mediana Edad , Universidades , Distrés Psicológico , Salud Global , SARS-CoV-2 , Pandemias
4.
Acta Neurochir (Wien) ; 166(1): 98, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386079

RESUMEN

PURPOSE: CSF diversion  is a recognised intervention in idiopathic intracranial hypertension (IIH), particularly in the presence of vision-threatening papilledema. Although ventriculo-atrial (VA) shunt insertion is a routine neurosurgical procedure, ventriculoperitoneal and lumboperitoneal shunts have been mostly used in this particular indication. This study aims to look at a single centre's experience with VA shunts in idiopathic intracranial hypertension (IIH). METHODS: Retrospective case series with a review of electronic records over a 10-year period; exclusion criteria were duplication of same shunt insertion, no VA shunt insertion, paediatric patients and indication other than IIH. Notes were reviewed for demographics, shunt survival (defined by time prior to revision) and reasons for revision. RESULTS: Eight VA shunt procedures were identified in 6 patients (mean age at insertion 34 ± 10 years) with a mean follow-up of 58 ± 25 months. All shunts were secondary procedures; 2 revisions from lumbo-pleural, 2 from ventriculopleural, 2 from ventriculoatrial and one each from ventriculoperitoneal and combined lumbo-/ventriculoperitoneal. At 50 months, 75% of VA shunts had survived, compared to only 58.3% of VPleural shunts in patients with IIH. Revisions were required due to acute intracranial bleed (1 case)-revised at day 1, and thrombus at distal site (1 case)-revised at day 57. Both shunts were later reinserted. From the latest clinic letters, all patients had their treatment optimised with this procedure, although only two patients had documented resolved papilloedema post-procedure. CONCLUSIONS: Ventriculo-atrial shunts are a safe and efficacious alternative option for CSF diversion in IIH. In this series, only 1 shunt was revised for a VA shunt-specific complication.


Asunto(s)
Seudotumor Cerebral , Humanos , Niño , Adulto Joven , Adulto , Seudotumor Cerebral/cirugía , Estudios Retrospectivos , Hemorragias Intracraneales , Prótesis e Implantes
5.
Int J Mol Sci ; 25(11)2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38892042

RESUMEN

Esophageal Cancer-Related Gene 2 (ECRG2), also known as Serine Peptidase Inhibitor Kazal type 7 (SPINK7), is a novel tumor suppressor gene from the SPINK family of genes that exhibits anticancer potential. ECRG2 was originally identified during efforts to discover genes involved in esophageal tumorigenesis. ECRG2 was one of those genes whose expression was absent or reduced in primary human esophageal cancers. Additionally, absent or reduced ECRG2 expression was also noted in several other types of human malignancies. ECRG2 missense mutations were identified in various primary human cancers. It was reported that a cancer-derived ECRG2 mutant (valine to glutamic acid at position 30) failed to induce cell death and caspase activation triggered by DNA-damaging anticancer drugs. Furthermore, ECRG2 suppressed cancer cell proliferation in cultured cells and grafted tumors in animals and inhibited cancer cell migration/invasion and metastasis. ECRG2 also was identified as a negative regulator of Hu-antigen R (HuR), an oncogenic RNA-binding protein that is known to regulate mRNA stability and the expression of transcripts corresponding to many cancer-related genes. ECRG2 function is important also for the regulation of inflammatory responses and the maintenance of epithelial barrier integrity in the esophagus. More recently, ECRG2 was discovered as one of the newest members of the pro-apoptotic transcriptional targets of p53. Two p53-binding sites (BS-1 and BS-2) were found within the proximal region of the ECRG2 gene promoter; the treatment of DNA-damaging agents in cancer cells significantly increased p53 binding to the ECRG2 promoter and triggered a strong ECRG2 promoter induction following DNA damage. Further, the genetic depletion of ECRG2 expression significantly impeded apoptotic cell death induced by DNA damage and wild-type p53 in cancer cells. These findings suggest that the loss of ECRG2 expression, commonly observed in human cancers, could play important roles in conferring anticancer drug resistance in human cancers. Thus, ECRG2 is a novel regulator in DNA damage-induced cell death that may also be a potential target for anticancer therapeutics.


Asunto(s)
Daño del ADN , Inhibidores de Serinpeptidasas Tipo Kazal , Humanos , Daño del ADN/genética , Animales , Inhibidores de Serinpeptidasas Tipo Kazal/genética , Inhibidores de Serinpeptidasas Tipo Kazal/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/metabolismo
6.
J Biol Chem ; 298(9): 102305, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35933019

RESUMEN

E3-SCF (Skp1/cullin-1/F-box protein) polyubiquitin ligases activate the proteasomal degradation of over a thousand proteins, but the evolutionary diversification of the F-box protein (FBP) family of substrate receptor subunits has challenged their elucidation in protists. Here, we expand the FBP candidate list in the social amoeba Dictyostelium and show that the Skp1 interactome is highly remodeled as cells transition from growth to multicellular development. Importantly, a subset of candidate FBPs was less represented when the posttranslational hydroxylation and glycosylation of Skp1 was abrogated by deletion of the O2-sensing Skp1 prolyl hydroxylase PhyA. A role for this Skp1 modification for SCF activity was indicated by partial rescue of development, which normally depends on high O2 and PhyA, of phyA-KO cells by proteasomal inhibitors. Further examination of two FBPs, FbxwD and the Jumonji C protein JcdI, suggested that Skp1 was substituted by other factors in phyA-KO cells. Although a double-KO of jcdI and its paralog jcdH did not affect development, overexpression of JcdI increased its sensitivity to O2. JcdI, a nonheme dioxygenase shown to have physiological O2 dependence, is conserved across protists with its F-box and other domains, and is related to the human oncogene JmjD6. Sensitization of JcdI-overexpression cells to O2 depended on its dioxygenase activity and other domains, but not its F-box, which may however be the mediator of its reduced levels in WT relative to Skp1 modification mutant cells. The findings suggest that activation of JcdI by O2 is tempered by homeostatic downregulation via PhyA and association with Skp1.


Asunto(s)
Amoeba , Dictyostelium , Histona Demetilasas con Dominio de Jumonji , Proteínas Quinasas Asociadas a Fase-S , Proteínas Ligasas SKP Cullina F-box , Amoeba/enzimología , Amoeba/genética , Dictyostelium/enzimología , Dictyostelium/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Oxígeno/metabolismo , Procolágeno-Prolina Dioxigenasa/metabolismo , Proteínas Quinasas Asociadas a Fase-S/genética , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Proteínas Ligasas SKP Cullina F-box/metabolismo
7.
Occup Environ Med ; 80(1): 51-60, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36280382

RESUMEN

OBJECTIVES: Adverse occupational exposures can accelerate age-related lung function decline. Some longitudinal population-based studies have investigated this association. This study aims to examine this association using findings reported by longitudinal population-based studies. METHODS: Ovid Medline, PubMed, Embase, and Web of Science were searched using keywords and text words related to occupational exposures and lung function and 12 longitudinal population-based studies were identified using predefined inclusion criteria. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Lung function decline was defined as annual loss of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) or the ratio (FEV1/FVC). Fixed and random-effects meta-analyses were conducted to calculate pooled estimates for ever and cumulative exposures. Heterogeneity was assessed using the I2 test, and publication bias was evaluated using funnel plots. RESULTS: Ever exposures to gases/fumes, vapours, gases, dusts, fumes (VGDF) and aromatic solvents were significantly associated with FEV1 decline in meta-analyses. Cumulative exposures for these three occupational agents observed a similar trend of FEV1 decline. Ever exposures to fungicides and cumulative exposures to biological dust, fungicides and insecticides were associated with FEV1 decline in fixed-effect models only. No statistically significant association was observed between mineral dust, herbicides and metals and FEV1 decline in meta-analyses. CONCLUSION: Pooled estimates from the longitudinal population-based studies have provided evidence that occupational exposures are associated with FEV1 decline. Specific exposure control and respiratory health surveillance are required to protect the lung health of the workers.


Asunto(s)
Fungicidas Industriales , Exposición Profesional , Humanos , Fungicidas Industriales/farmacología , Exposición Profesional/efectos adversos , Pulmón , Volumen Espiratorio Forzado , Capacidad Vital , Polvo , Gases , Estudios Longitudinales
8.
Mol Cell Proteomics ; 20: 100045, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33376194

RESUMEN

HPLC has been employed for decades to enhance detection sensitivity and quantification of complex analytes within biological mixtures. Among these analytes, glycans released from glycoproteins and glycolipids have been characterized as underivatized or fluorescently tagged derivatives by HPLC coupled to various detection methods. These approaches have proven extremely useful for profiling the structural diversity of glycoprotein and glycolipid glycosylation but require the availability of glycan standards and secondary orthogonal degradation strategies to validate structural assignments. A robust method for HPLC separation of glycans as their permethylated derivatives, coupled with in-line multidimensional ion fragmentation (MSn) to assign structural features independent of standards, would significantly enhance the depth of knowledge obtainable from biological samples. Here, we report an optimized workflow for LC-MS analysis of permethylated glycans that includes sample preparation, mobile phase optimization, and MSn method development to resolve structural isomers on-the-fly. We report baseline separation and MSn of isomeric N- and O-glycan structures, aided by supplementing mobile phases with Li+, which simplifies adduct heterogeneity and facilitates cross-ring fragmentation to obtain valuable monosaccharide linkage information. Our workflow has been adapted from standard proteomics-based workflows and, therefore, provides opportunities for laboratories with expertise in proteomics to acquire glycomic data with minimal deviation from existing buffer systems, chromatography media, and instrument configurations. Furthermore, our workflow does not require a mass spectrometer with high-resolution/accurate mass capabilities. The rapidly evolving appreciation of the biological significance of glycans for human health and disease requires the implementation of high-throughput methods to identify and quantify glycans harvested from sample sets of sufficient size to achieve appropriately powered statistical significance. The LC-MSn approach we report generates glycan isomeric separations and robust structural characterization and is amenable to autosampling with associated throughput enhancements.


Asunto(s)
Polisacáridos/metabolismo , Animales , Encéfalo/metabolismo , Línea Celular , Cromatografía de Fase Inversa , Células Epiteliales/metabolismo , Glicómica/métodos , Humanos , Isomerismo , Metilación , Ratones , Polisacáridos/química , Espectrometría de Masas en Tándem
9.
J Biol Chem ; 296: 100769, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33971197

RESUMEN

Acid alpha-glucosidase (GAA) is a lysosomal glycogen-catabolizing enzyme, the deficiency of which leads to Pompe disease. Pompe disease can be treated with systemic recombinant human GAA (rhGAA) enzyme replacement therapy (ERT), but the current standard of care exhibits poor uptake in skeletal muscles, limiting its clinical efficacy. Furthermore, it is unclear how the specific cellular processing steps of GAA after delivery to lysosomes impact its efficacy. GAA undergoes both proteolytic cleavage and glycan trimming within the endolysosomal pathway, yielding an enzyme that is more efficient in hydrolyzing its natural substrate, glycogen. Here, we developed a tool kit of modified rhGAAs that allowed us to dissect the individual contributions of glycan trimming and proteolysis on maturation-associated increases in glycogen hydrolysis using in vitro and in cellulo enzyme processing, glycopeptide analysis by MS, and high-pH anion-exchange chromatography with pulsed amperometric detection for enzyme kinetics. Chemical modifications of terminal sialic acids on N-glycans blocked sialidase activity in vitro and in cellulo, thereby preventing downstream glycan trimming without affecting proteolysis. This sialidase-resistant rhGAA displayed only partial activation after endolysosomal processing, as evidenced by reduced catalytic efficiency. We also generated enzymatically deglycosylated rhGAA that was shown to be partially activated despite not undergoing proteolytic processing. Taken together, these data suggest that an optimal rhGAA ERT would require both N-glycan and proteolytic processing to attain the most efficient enzyme for glycogen hydrolysis and treatment of Pompe disease. Future studies should examine the amenability of next-generation ERTs to both types of cellular processing.


Asunto(s)
Endosomas/metabolismo , Polisacáridos/metabolismo , alfa-Glucosidasas/metabolismo , Glucógeno/metabolismo , Enfermedad del Almacenamiento de Glucógeno Tipo II/metabolismo , Glicopéptidos/metabolismo , Humanos , Hidrólisis , Proteolisis
10.
Occup Environ Med ; 79(5): 347-357, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34782367

RESUMEN

Coal mine workers are exposed to a number of workplace hazards which may increase the risk of cancer and mortality. We conducted a systematic review and meta-analysis to investigate cancer and mortality in coal mine workers We searched in Ovid Medline, PubMed, Embase and Web of Science databases using keywords and text words related to coal mines, cancer and mortality and identified 36 full-text articles using predefined inclusion criteria. Each study's quality was assessed using the Newcastle-Ottawa Scale. We performed random-effect meta-analyses including 21 of the identified articles evaluating cancer and/or mortality of coal mine workers. The meta-analysis showed an increased risk of all-cause mortality (SMR 1.14, 95% CI 1.00 to 1.30) and mortality from non-malignant respiratory disease (NMRD) (3.59, 95% CI 3.00 to 4.30) in cohorts with coal workers' pneumoconiosis (CWP). We found a somewhat increased risk of stomach cancer (1.11, 95% CI 0.97 to 1.35) and of mortality from NMRD (1.26, 95% CI 0.99 to 1.61) in the cohorts of coal miners with unknown CWP status. The meta-analysis also showed a decreased risk of prostate cancer and cardiovascular and cerebrovascular mortality among coal miners. This may be a result of the healthy worker effect and possible lower smoking rates, and perhaps also reflect the physically active nature of many jobs in coal mines. The meta-analysis for lung cancer did not show increased risk in coal miners with CWP (1.49, 95% CI 0.70 to 3.18) or for coal miners of unknown CWP status (1.03, 95% CI 0.91 to 1.18). Lower smoking rates in coal mine workers could explain why case-control studies where smoking was controlled for showed higher risks for lung cancer than were seen in cohort studies. Coal mine workers are at increased risk of mortality from NMRD but decreased risk of prostate cancer and cardiovascular and cerebrovascular mortality. Studies of coal mine workers need long-term follow-up to identify increased mortality and cancer incidence.


Asunto(s)
Minas de Carbón , Neoplasias Pulmonares , Mineros , Enfermedades Profesionales , Neumoconiosis , Neoplasias de la Próstata , Carbón Mineral , Humanos , Neoplasias Pulmonares/epidemiología , Masculino , Enfermedades Profesionales/epidemiología , Neumoconiosis/epidemiología
11.
Skeletal Radiol ; 51(3): 451-475, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34155550

RESUMEN

Periarticular calcification and ossification is a frequent finding on imaging and may sometimes pose a diagnostic challenge. The differential diagnoses for this radiological finding are wide and can be classified into broad groups such as idiopathic, developmental, trauma, burns, infection, tumor, connective tissue disease, crystalline, metabolic, vascular, and foreign bodies. With careful consideration of the clinical and imaging findings as well as awareness of mimickers of periarticular mineralization, the list of differential diagnoses can be narrowed down. This article aims to review the clinical-radiologic findings of periarticular calcified or ossified lesions with relevant imaging illustrations.


Asunto(s)
Calcinosis , Osteoartritis , Calcinosis/diagnóstico por imagen , Diagnóstico Diferencial , Humanos
12.
HPB (Oxford) ; 24(2): 234-243, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34294525

RESUMEN

BACKGROUND: Sickle cell disease (SCD) is a rare hemoglobinopathy which can result in chronic liver disease and cirrhosis. Patients with SCD have an increased risk of hematologic malignancy, but the prevalence of hepatocellular carcinoma (HCC) in this population is unknown. Herein, the association of SCD with HCC was examined using registry data. METHODS: The SEER-Medicare database was queried to identify patients diagnosed with HCC between 2000 and 2015, and further stratified by SCD status. Propensity matching was performed to examine cancer-related survival and treatment outcomes. RESULTS: Overall 56,934 patients with HCC were identified, including 81 patients with SCD. Patients with SCD more frequently had cirrhosis [48.1% (39/81) vs 23.5% (13,377/56,853), p < 0.01] yet presented with smaller tumors [<5 cm: 51.9% (42/81) vs 38.5% (21,898/56,853), p = 0.01]. After propensity matching, SCD was not associated with attenuated survival (aHR 0.73 95%CI 0.52-1.01). When stratified by treatment, patients with SCD had equivalent outcomes to chemotherapy (p = 0.65), TACE/TARE (p = 0.35), resection (p = 0.15) and transplantation (p = 0.67) when compared to non-SCD patients. CONCLUSION: This study confirms that a subset of patients with SCD will develop HCC. Importantly, therapeutic options for HCC should not be limited by pre-existing SCD, and similar survival should be expected when compared to non-SCD patients.


Asunto(s)
Anemia de Células Falciformes , Carcinoma Hepatocelular , Neoplasias Hepáticas , Anciano , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/diagnóstico , Anemia de Células Falciformes/epidemiología , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/terapia , Humanos , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/terapia , Medicare , Puntaje de Propensión , Estudios Retrospectivos , Resultado del Tratamiento , Estados Unidos/epidemiología
13.
J Biol Chem ; 295(27): 9223-9243, 2020 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-32414843

RESUMEN

Skp1, a subunit of E3 Skp1/Cullin-1/F-box protein ubiquitin ligases, is modified by a prolyl hydroxylase that mediates O2 regulation of the social amoeba Dictyostelium and the parasite Toxoplasma gondii The full effect of hydroxylation requires modification of the hydroxyproline by a pentasaccharide that, in Dictyostelium, influences Skp1 structure to favor assembly of Skp1/F-box protein subcomplexes. In Toxoplasma, the presence of a contrasting penultimate sugar assembled by a different glycosyltransferase enables testing of the conformational control model. To define the final sugar and its linkage, here we identified the glycosyltransferase that completes the glycan and found that it is closely related to glycogenin, an enzyme that may prime glycogen synthesis in yeast and animals. However, the Toxoplasma enzyme catalyzes formation of a Galα1,3Glcα linkage rather than the Glcα1,4Glcα linkage formed by glycogenin. Kinetic and crystallographic experiments showed that the glycosyltransferase Gat1 is specific for Skp1 in Toxoplasma and also in another protist, the crop pathogen Pythium ultimum The fifth sugar is important for glycan function as indicated by the slow-growth phenotype of gat1Δ parasites. Computational analyses indicated that, despite the sequence difference, the Toxoplasma glycan still assumes an ordered conformation that controls Skp1 structure and revealed the importance of nonpolar packing interactions of the fifth sugar. The substitution of glycosyltransferases in Toxoplasma and Pythium by an unrelated bifunctional enzyme that assembles a distinct but structurally compatible glycan in Dictyostelium is a remarkable case of convergent evolution, which emphasizes the importance of the terminal α-galactose and establishes the phylogenetic breadth of Skp1 glycoregulation.


Asunto(s)
Galactosa/metabolismo , Proteínas Ligasas SKP Cullina F-box/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Dictyostelium/metabolismo , Proteínas F-Box/metabolismo , Glucosiltransferasas/metabolismo , Glicoproteínas/metabolismo , Glicosilación , Glicosiltransferasas/metabolismo , Hidroxilación , Hidroxiprolina/metabolismo , Filogenia , Procolágeno-Prolina Dioxigenasa/genética , Prolil Hidroxilasas/metabolismo , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Proteínas Ligasas SKP Cullina F-box/fisiología , Toxoplasma/metabolismo
14.
J Biol Chem ; 295(9): 2804-2821, 2020 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-31964714

RESUMEN

Animal cells express heparan sulfate proteoglycans that perform many important cellular functions by way of heparan sulfate-protein interactions. The identification of membrane heparan sulfate-binding proteins is challenging because of their low abundance and the need for extensive enrichment. Here, we report a proteomics workflow for the identification and characterization of membrane-anchored and extracellular proteins that bind heparan sulfate. The technique is based on limited proteolysis of live cells in the absence of denaturation and fixation, heparin-affinity chromatography, and high-resolution LC-MS/MS, and we designate it LPHAMS. Application of LPHAMS to U937 monocytic and primary murine and human endothelial cells identified 55 plasma membrane, extracellular matrix, and soluble secreted proteins, including many previously unidentified heparin-binding proteins. The method also facilitated the mapping of the heparin-binding domains, making it possible to predict the location of the heparin-binding site. To validate the discovery feature of LPHAMS, we characterized one of the newly-discovered heparin-binding proteins, C-type lectin 14a (CLEC14A), a member of the C-type lectin family that modulates angiogenesis. We found that the C-type lectin domain of CLEC14A binds one-to-one to heparin with nanomolar affinity, and using molecular modeling and mutagenesis, we mapped its heparin-binding site. CLEC14A physically interacted with other glycosaminoglycans, including endothelial heparan sulfate and chondroitin sulfate E, but not with neutral or sialylated oligosaccharides. The LPHAMS technique should be applicable to other cells and glycans and provides a way to expand the repertoire of glycan-binding proteins for further study.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Endotelio/química , Heparitina Sulfato/metabolismo , Lectinas Tipo C/metabolismo , Proteínas de la Membrana/metabolismo , Proteómica/métodos , Animales , Sitios de Unión , Células Cultivadas , Endotelio/citología , Humanos , Ratones , Unión Proteica , Células U937
15.
J Hepatol ; 74(1): 66-79, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32561318

RESUMEN

BACKGROUND & AIMS: Failure to control oesophago-gastric variceal bleeding (OGVB) and acute-on-chronic liver failure (ACLF) are both important prognostic factors in cirrhosis. The aims of this study were to determine whether ACLF and its severity define the risk of death in OGVB and whether insertion of rescue transjugular intrahepatic shunt (TIPS) improves survival in patients with failure to control OGVB and ACLF. METHODS: Data on 174 consecutive eligible patients, with failure to control OGVB between 2005 and 2015, were collected from a prospectively maintained intensive care unit registry. Rescue TIPS was defined as technically successful TIPS within 72 hours of presentation with failure to control OGVB. Cox-proportional hazards regression analyses were applied to explore the impact of ACLF and TIPS on survival in patients with failure to control OGVB. RESULTS: Patients with ACLF (n = 119) were significantly older, had organ failures and higher white cell count than patients with acute decompensation (AD, n = 55). Mortality at 42-days and 1-year was significantly higher in patients with ACLF (47.9% and 61.3%) than in those with AD (9.1% and 12.7%, p <0.001), whereas there was no difference in the number of endoscopies and transfusion requirements between these groups. TIPS was inserted in 78 patients (AD 21 [38.2%]; ACLF 57 [47.8%]; p = 0.41). In ACLF, rescue TIPS insertion was an independent favourable prognostic factor for 42-day mortality. In contrast, rescue TIPS did not impact on the outcome of patients with AD. CONCLUSIONS: This study shows that in patients with failure to control OGVB, the presence and severity of ACLF determines the risk of 42-day and 1-year mortality. Rescue TIPS is associated with improved survival in patients with ACLF. LAY SUMMARY: Variceal bleeding that is not controlled by initial endoscopy is associated with high risk of death. The results of this study showed that in the occurrence of failure of the liver and other organs defines the risk of death. In these patients, insertion of a shunt inside the liver to drain the portal vein improves survival.


Asunto(s)
Insuficiencia Hepática Crónica Agudizada , Transfusión Sanguínea , Várices Esofágicas y Gástricas , Hemorragia Gastrointestinal , Hemostasis Quirúrgica , Cirrosis Hepática , Derivación Portosistémica Intrahepática Transyugular/métodos , Insuficiencia Hepática Crónica Agudizada/sangre , Insuficiencia Hepática Crónica Agudizada/diagnóstico , Insuficiencia Hepática Crónica Agudizada/etiología , Insuficiencia Hepática Crónica Agudizada/mortalidad , Factores de Edad , Transfusión Sanguínea/métodos , Transfusión Sanguínea/estadística & datos numéricos , Várices Esofágicas y Gástricas/complicaciones , Várices Esofágicas y Gástricas/diagnóstico , Femenino , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/mortalidad , Hemorragia Gastrointestinal/cirugía , Hemostasis Quirúrgica/métodos , Hemostasis Quirúrgica/estadística & datos numéricos , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Recuento de Leucocitos/métodos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Londres/epidemiología , Masculino , Persona de Mediana Edad , Mortalidad , Puntuaciones en la Disfunción de Órganos , Pronóstico , Medición de Riesgo , Insuficiencia del Tratamiento
16.
Anal Bioanal Chem ; 413(4): 967-978, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33230700

RESUMEN

Detection of hepatitis B Virus surface antigen (HBsAg) is an established method for diagnosing both acute and chronic hepatitis B virus (HBV) infection. In addition to enzyme immunoassays (EIAs), rapid diagnostic tests (RDTs) are available for the detection of HBsAg in resource-poor settings. However, the available RDTs have inadequate sensitivity and therefore are not suitable for diagnosis of patients with low levels of HBsAg and for blood screening. To provide a high-sensitivity RDT, we developed a lateral flow immunoassay (LFIA) for HBsAg utilizing upconverting nanoparticle (UCNP) reporter. The UCNP-LFIA can use whole blood, serum, or plasma and the results can be read in 30 min using a reader device. When compared with a commercial conventional visually read LFIA, the developed UCNP-LFIA had a Limit of Detection (LoD) of 0.1 IU HBsAg/ml in spiked serum, whereas the LoD of the conventional LFIA was 3.2 IU HBsAg/ml. The developed UCNP-LFIA fulfills the WHO criterion for blood screening (LoD ≤ 0.13 IU HBsAg/ml) in terms of LoD. The UCNP-LFIA and conventional LFIA were evaluated with well-characterized sample panels. The UCNP-LFIA detected 20/24 HBsAg-positive samples within the HBsAg Performance Panel and 8/10 samples within the Mixed Titer Performance Panel, whereas the conventional LFIA detected 8/24 and 4/10 samples in these panels, respectively. The performance of the assays was further evaluated with HBsAg-positive (n = 108) and HBsAg-negative (n = 315) patient samples. In comparison with a central laboratory test, UCNP-LFIA showed 95.4% (95% CI: 89.5-98.5%) sensitivity whereas sensitivity of the conventional LFIA was 87.7% (95%CI: 79.9-93.3%).


Asunto(s)
Anticuerpos Inmovilizados/química , Antígenos de Superficie de la Hepatitis B/análisis , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/diagnóstico , Inmunoensayo/métodos , Nanopartículas/química , Diseño de Equipo , Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Inmunoensayo/instrumentación , Límite de Detección , Mediciones Luminiscentes/instrumentación , Mediciones Luminiscentes/métodos
17.
Global Health ; 17(1): 117, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34598720

RESUMEN

BACKGROUND: The current pandemic of COVID-19 impacted the psychological wellbeing of populations globally. OBJECTIVES: We aimed to examine the extent and identify factors associated with psychological distress, fear of COVID-19 and coping. METHODS: We conducted a cross-sectional study across 17 countries during Jun-2020 to Jan-2021. Levels of psychological distress (Kessler Psychological Distress Scale), fear of COVID-19 (Fear of COVID-19 Scale), and coping (Brief Resilient Coping Scale) were assessed. RESULTS: A total of 8,559 people participated; mean age (±SD) was 33(±13) years, 64% were females and 40% self-identified as frontline workers. More than two-thirds (69%) experienced moderate-to-very high levels of psychological distress, which was 46% in Thailand and 91% in Egypt. A quarter (24%) had high levels of fear of COVID-19, which was as low as 9% in Libya and as high as 38% in Bangladesh. More than half (57%) exhibited medium to high resilient coping; the lowest prevalence (3%) was reported in Australia and the highest (72%) in Syria. Being female (AOR 1.31 [95% CIs 1.09-1.57]), perceived distress due to change of employment status (1.56 [1.29-1.90]), comorbidity with mental health conditions (3.02 [1.20-7.60]) were associated with higher levels of psychological distress and fear. Doctors had higher psychological distress (1.43 [1.04-1.97]), but low levels of fear of COVID-19 (0.55 [0.41-0.76]); nurses had medium to high resilient coping (1.30 [1.03-1.65]). CONCLUSIONS: The extent of psychological distress, fear of COVID-19 and coping varied by country; however, we identified few higher risk groups who were more vulnerable than others. There is an urgent need to prioritise health and well-being of those people through well-designed intervention that may need to be tailored to meet country specific requirements.


Asunto(s)
Adaptación Psicológica , COVID-19/psicología , Miedo , Salud Global/estadística & datos numéricos , Distrés Psicológico , Adulto , COVID-19/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores Socioeconómicos , Adulto Joven
18.
BMC Public Health ; 21(1): 2108, 2021 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-34789208

RESUMEN

BACKGROUND: Diabetes mellitus represents a substantial global health challenge, with prevalence rising in low- and middle-income countries (LMICs). Although diabetes is known to follow a socioeconomic gradient, patterns in LMICs are unclear. This study examined associations between education and diabetes, and diabetes self-management behaviours, in six LMICs. METHODS: Cross-sectional data for 31,780 participants from China, Ghana, India, Mexico, Russia, and South Africa from the World Health Organization Study on Global AGEing and adult health (SAGE) study were used. Participants aged ≥50 years completed face-to-face interviews between 2007 and 2010. Participants self-reported diabetes diagnosis, physical activity, sedentary time, fruit and vegetable consumption, any special diet/program for diabetes, whether they were taking insulin for diabetes and number of years of education. Height, weight, waist, and hip circumference were measured. Country-specific survey-weighted log-binomial regression models were fitted to examine associations between the number of years of education and self-reported diabetes diagnosis (primary analysis). In secondary analyses, among those with a self-reported diabetes diagnosis, generalised linear regression models were fitted to examine associations between education and i) physical activity, ii) sedentary time, iii) fruit and vegetable consumption, iv) special diet for diabetes, v) taking insulin, vi) BMI, vii) waist circumference and viii) hip circumference. RESULTS: There was strong evidence of an association between years of education and diabetes diagnosis in Ghana (RR = 1.09, 95% CI: 1.06-1.13) and India (RR = 1.09, 95% CI: 1.07-1.12) only. In India, greater years of education was associated with higher leisure physical activity, fruit and vegetable intake, rates following a special diet or taking insulin, but also higher mean BMI, waist and hip circumference. Relationships between education and self-management behaviours were rarely seen in the other countries. CONCLUSIONS: Associations between education and diabetes, and behavioural self-management (India only) was more evident in the two least developed (Ghana and India) of the WHO SAGE countries, indicating increasing diabetes diagnosis with greater numbers of years of education. The lack of gradients elsewhere may reflect shifting risk from higher to lower educated populations. While there was some suggestion that self-management behaviours were greater with increased education in India, this was not observed in the other countries.


Asunto(s)
Diabetes Mellitus , Automanejo , Adulto , China , Estudios Transversales , Países en Desarrollo , Conductas Relacionadas con la Salud , Humanos , India , Prevalencia , Organización Mundial de la Salud
19.
Sensors (Basel) ; 21(2)2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33418986

RESUMEN

Rapid diagnostic tests (RDTs) are often used for the detection of anti-human immunodeficiency virus (HIV) antibodies in remote locations in low- and middle-income countries (LMIC) with low or limited access to central laboratories. The typical format of an RDT is a lateral flow assay (LFA) with visual interpretation prone to subjectivity. This risk of misinterpretation can be overcome with luminescent upconverting nanoparticle reporters (UCNPs) measured with a miniaturized easy-to-use reader instrument. An LFA with UCNPs for anti-HIV-1/2 antibodies was developed and the assay performance was evaluated extensively with challenging patient sample panels. Sensitivity (n = 145) of the UCNP-LFA was 96.6% (95% CI: 92.1-98.8%) and specificity (n = 309) was 98.7% (95% CI: 96.7-99.7%). Another set of samples (n = 200) was used for a comparison between the UCNP-LFA and a conventional visual RDT. In this comparison, the sensitivities for HIV-1 were 96.4% (95% CI: 89.8-99.3%) and 97.6% (95% CI: 91.6-99.7%), for the UCNP-LFA and conventional RDT, respectively. The specificity was 100% (95% CI: 96.4-100%) for both assays. The developed UCNP-LFA demonstrates the applicability of UCNPs for the detection of anti-HIV antibodies. The signal measurement is done by a reader instrument, which may facilitate automated result interpretation, archiving and transfer of data from de-centralized locations.


Asunto(s)
VIH-1 , Nanopartículas , Anticuerpos , Humanos , Inmunoensayo , Pruebas Inmunológicas , Sensibilidad y Especificidad
20.
Glycobiology ; 30(10): 817-829, 2020 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-32149355

RESUMEN

Mutations in multiple genes required for proper O-mannosylation of α-dystroglycan are causal for congenital/limb-girdle muscular dystrophies and abnormal brain development in mammals. Previously, we and others further elucidated the functional O-mannose glycan structure that is terminated by matriglycan, [(-GlcA-ß3-Xyl-α3-)n]. This repeating disaccharide serves as a receptor for proteins in the extracellular matrix. Here, we demonstrate in vitro that HNK-1 sulfotransferase (HNK-1ST/carbohydrate sulfotransferase) sulfates terminal glucuronyl residues of matriglycan at the 3-hydroxyl and prevents further matriglycan polymerization by the LARGE1 glycosyltransferase. While α-dystroglycan isolated from mouse heart and kidney is susceptible to exoglycosidase digestion of matriglycan, the functional, lower molecular weight α-dystroglycan detected in brain, where HNK-1ST expression is elevated, is resistant. Removal of the sulfate cap by a sulfatase facilitated dual-glycosidase digestion. Our data strongly support a tissue specific mechanism in which HNK-1ST regulates polymer length by competing with LARGE for the 3-position on the nonreducing GlcA of matriglycan.


Asunto(s)
Distroglicanos/metabolismo , Ácido Glucurónico/metabolismo , Sulfotransferasas/metabolismo , Animales , Distroglicanos/química , Ácido Glucurónico/química , Glicosilación , Ratones , Sulfotransferasas/química , Sulfotransferasas/aislamiento & purificación
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