Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
2.
Viruses ; 16(1)2024 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-38257816

RESUMO

HIV-1 latency maintenance and reactivation are regulated by several viral and host factors. One such factor is Krüppel-associated box (KRAB)-associated protein 1 (KAP1: also named TRIM28 or TIF1ß). While initial studies have revealed KAP1 to be a positive regulator of latency reversal in transformed and primary CD4+ T cells, subsequent studies have proposed KAP1 to be a repressor required for latency maintenance. Given this discrepancy, in this study, we re-examine KAP1 transcription regulatory functions using a chemical genetics strategy to acutely deplete KAP1 expression to avoid the accumulation of indirect effects. Notably, KAP1 acute loss partially decreased HIV-1 promoter activity in response to activating signals, a function that can be restored upon complementation with exogenous KAP1, thus revealing that KAP1-mediated activation is on target. By combining comprehensive KAP1 domain deletion and mutagenesis in a cell-based reporter assay, we genetically defined the RING finger domain and an Intrinsically Disordered Region as key activating features. Together, our study solidifies the notion that KAP1 activates HIV-1 transcription by exploiting its multi-domain protein arrangement via previously unknown domains and functions.


Assuntos
HIV-1 , Ativação Transcricional , Proteína 28 com Motivo Tripartido , Humanos , HIV-1/genética , Mutagênese , Domínios RING Finger , Proteína 28 com Motivo Tripartido/genética
3.
ACS Appl Mater Interfaces ; 16(2): 2704-2715, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38150329

RESUMO

Liquid crystal elastomer (LCE)-based soft actuators are being studied for their significant shape-changing abilities when they are exposed to heat or light. Nevertheless, their relatively slow response compared with soft magnetic materials limits their application possibilities. Integration of magnetic responsiveness with LCEs has been previously attempted; however, the LCE response is typically jeopardized in high volumes of magnetic microparticles (MMPs). Here, a multistimuli, magnetically active LCE (MLCE), capable of producing programmable and multimodal actuation, is presented. The MLCE, composed of MMPs within an LCE matrix, is generated through extrusion-based 4D printing that enables digital control of mesogen orientation even at a 1:1 (LCE:MMPs) weight ratio, a challenging task to accomplish with other methods. The printed actuators can significantly deform when thermally actuated as well as exhibit fast response to magnetic fields. When combining thermal and magnetic stimuli, modes of actuation inaccessible with only one input are achieved. For instance, the actuator is reconfigured into various states by using the heat-mediated LCE response, followed by subsequent magnetic addressing. The multistimuli capabilities of the MLCE composite expand its applicability where common LCE actuators face limitations in speed and precision. To illustrate, a beam-steering device developed by using these materials is presented.

4.
Case Rep Dent ; 2023: 5714099, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37799173

RESUMO

Central mucoepidermoid carcinoma (CMEC) is a rare pathological entity with only a few case reports in the literature. The present case reported an uncommon occurrence of CMEC mimicking an odontogenic lesion in a young patient. A 17-year-old female patient sought dental care due to a slight swelling located in the posterior region of the mandible on the left side. Radiographic exams revealed an osteolytic lesion with defined limits in relation to proximity to the pericoronal follicle of tooth #38. The clinical and radiographic diagnostic hypothesis was an odontogenic lesion. Histological sections showed the presence of a neoplasm of glandular origin, not encapsulated, with a predominantly cystic growth pattern. The neoplasm consisted of mucous, intermediate, and squamous cells. In the immunohistochemical staining, the neoplastic cells were positive for cytokeratin 7. Mucous cells were positive for PAS with diastase digestion. The final diagnosis consisted of mucoepidermoid carcinoma. The tumor was removed surgically, and the patient has shown no signs of relapse nor recurrence. In conclusion, CMEC may mimic radiographic features of various pathologies, but despite its rarity, clinicians and oral radiologists should consider CMEC as a diagnostic hypothesis for jaw lesions.

5.
Proc Natl Acad Sci U S A ; 120(42): e2305295120, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37816059

RESUMO

Coordinated expression of ion channels is crucial for cardiac rhythms, neural signaling, and cell cycle progression. Perturbation of this balance results in many disorders including cardiac arrhythmias. Prior work revealed association of mRNAs encoding cardiac NaV1.5 (SCN5A) and hERG1 (KCNH2), but the functional significance of this association was not established. Here, we provide a more comprehensive picture of KCNH2, SCN5A, CACNA1C, and KCNQ1 transcripts collectively copurifying with nascent hERG1, NaV1.5, CaV1.2, or KCNQ1 channel proteins. Single-molecule fluorescence in situ hybridization (smFISH) combined with immunofluorescence reveals that the channel proteins are synthesized predominantly as heterotypic pairs from discrete molecules of mRNA, not as larger cotranslational complexes. Puromycin disrupted colocalization of mRNA with its encoded protein, as expected, but remarkably also pairwise mRNA association, suggesting that transcript association relies on intact translational machinery or the presence of the nascent protein. Targeted depletion of KCHN2 by specific shRNA resulted in concomitant reduction of all associated mRNAs, with a corresponding reduction in the encoded channel currents. This co-knockdown effect, originally described for KCNH2 and SCN5A, thus appears to be a general phenomenon among transcripts encoding functionally related proteins. In multielectrode array recordings, proarrhythmic behavior arose when IKr was reduced by the selective blocker dofetilide at IC50 concentrations, but not when equivalent reductions were mediated by shRNA, suggesting that co-knockdown mitigates proarrhythmic behavior expected from the selective reduction of a single channel species. We propose that coordinated, cotranslational association of functionally related ion channel mRNAs confers electrical stability by co-regulating complementary ion channels in macromolecular complexes.


Assuntos
Arritmias Cardíacas , Canal de Potássio KCNQ1 , Humanos , Canal de Potássio KCNQ1/genética , Canal de Potássio ERG1/genética , Hibridização in Situ Fluorescente , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-37835140

RESUMO

Puerto Rico (PR) has faced environmental and public health challenges that could have significantly affected cancer screening access. Using administrative claims data from PR's Medicaid population, this study assessed trends in colorectal and breast cancer screening from 2016 to 2021, the impact of disasters in screening, and the absolute deficit in screening due to the pandemic. The monthly rates of claims were analyzed using Poisson regression. Significant reductions in breast and colorectal cancer screening utilization were observed. The colorectal cancer screening rate in 2017 was 77% lower a month after Hurricanes Irma and María [RRadj: 0.23; 95% CI: 0.20, 0.25] compared to the same time period in 2016. Breast cancer screening dropped 50% in November 2017 compared to November 2016 [RRadj: 0.50; 95% CI: 0.47, 0.54]. Prospectively, a recovery in utilization has been observed only for breast cancer screening. The results revealed that cancer screening utilization substantially declined after environmental disasters and the pandemic. These findings have potentially severe long-term implications for cancer health disparities and mortality in PR.


Assuntos
Neoplasias da Mama , COVID-19 , Neoplasias Colorretais , Tempestades Ciclônicas , Humanos , Feminino , Porto Rico/epidemiologia , Pandemias , Detecção Precoce de Câncer , COVID-19/epidemiologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia
7.
Arch Physiol Biochem ; 129(5): 1058-1070, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33689540

RESUMO

We investigated how oxidative stress (OS) alters Ca2+ handling in ventricular myocytes in early metabolic syndrome (MetS) in sucrose-fed rats. The effects of N-acetyl cysteine (NAC) or dl-Dithiothreitol (DTT) on systolic Ca2+ transients (SCaTs), diastolic Ca2+ sparks (CaS) and Ca2+ waves (CaW), recorded by confocal techniques, and L-type Ca2+ current (ICa), assessed by whole-cell patch clamp, were evaluated in MetS and Control cells. MetS myocytes exhibited decreased SCaTs and CaS frequency but unaffected CaW propagation. In Control cells, NAC/DTT reduced RyR2/SERCA2a activity blunting SCaTs, CaS frequency and CaW propagation, suggesting that basal ROS optimised Ca2+ signalling by maintaining RyR2/SERCA2a function and that these proteins facilitate CaW propagation. Conversely, NAC/DTT in MetS recovered RyR2/SERCA2a function, improving SCaTs and CaS frequency, but unexpectedly decreasing CaW propagation. We hypothesised that OS decreases RyR2/SERCA2a activity at early MetS, and while decreased SERCA2a favours CaW propagation, diminished RyR2 restrains it.


Assuntos
Síndrome Metabólica , Canal de Liberação de Cálcio do Receptor de Rianodina , Ratos , Animais , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/farmacologia , Síndrome Metabólica/metabolismo , Miócitos Cardíacos , Estresse Oxidativo
9.
Int J Urol ; 29(5): 376-382, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35118726

RESUMO

OBJECTIVES: Penile urethral stricture disease not associated with hypospadias is rare, and there is a wide range of commonly used surgical repair techniques for this disease. We sought to compile a multi-institutional database of patients who had surgical correction of strictures in the penile urethra not limited to the meatus, and who had no history of hypospadias, for analysis using the Trauma and Urologic Reconstructive Network of Surgeons length, urethral segment and etiology classification system. METHODS: A retrospective database from 13 institutions was compiled of patients who had undergone surgical correction of Trauma and Urologic Reconstructive Network of Surgeons length, urethral segment and etiology urethral stricture segments S2b/S2c and excluding E5, with a minimum follow-up time of 4 months. Failure was defined as cystoscopically confirmed recurrence of a stricture measuring less than 16-Fr. RESULTS: We analyzed 222 patients with a median age of 57 years and a follow-up of 49 months. The overall surgical success rate was 80.2%. On multivariate analysis, the two variables identified that were predictive of surgical success were stricture length ≤2 cm as well as use of a buccal mucosa graft as compared to use of a fasciocutaneous flap, which had success rates of 83% and 52%, respectively (P = 0.0004). No statistically significant differences were found based on incisional approach or surgical technique, nor were outcomes different based on etiology or preoperative patient demographics. CONCLUSIONS: Surgical repair of penile urethral strictures of non-hypospadiac origin have a favorable overall success rate, at 80.2%. Regardless of incisional approach or surgical technique, all operations appear to have similar outcomes other than repairs using fasciocutaneous flap, which were statistically less successful than those using buccal mucosa graft.


Assuntos
Hipospadia , Estreitamento Uretral , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Feminino , Humanos , Hipospadia/complicações , Hipospadia/cirurgia , Masculino , Pessoa de Meia-Idade , Pênis/cirurgia , Estudos Retrospectivos , Estreitamento Uretral/etiologia , Estreitamento Uretral/cirurgia
10.
Sci Rep ; 12(1): 536, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017617

RESUMO

To evaluate the effect of the combination of linagliptin and insulin on metabolic control and prognosis in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and hyperglycemia. A parallel double-blind randomized clinical trial including hospitalized patients with SARS-CoV-2 infection and hyperglycemia, randomized to receive 5 mg linagliptin + insulin (LI group) or insulin alone (I group) was performed. The main outcomes were the need for assisted mechanical ventilation and glucose levels during hospitalization. Subjects were screened for eligibility at hospital admission if they were not with assisted mechanical ventilation and presented hyperglycemia, and a total of 73 patients with SARS-CoV-2 infection and hyperglycemia were randomized to the LI group (n = 35) or I group (n = 38). The average hospital stay was 12 ± 1 vs 10 ± 1 days for the I and LI groups, respectively (p = 0.343). There were no baseline clinical differences between the study groups, but the percentage of males was higher in the LI group (26 vs 18, p = 0.030). The improvements in fasting and postprandial glucose levels were better in the LI group that the I group (122 ± 7 vs 149 ± 10, p = 0.033; and 137 ± 7 vs 173 ± 12, p = 0.017, respectively), and insulin requirements tended to be lower in the LI group than the I group. Three patients in the LI group and 12 in the I group required assisted mechanical ventilation (HR 0.258, CI 95% 0.092-0.719, p = 0.009); 2 patients in the LI group and 6 in the I group died after a follow-up of 30 days (p = 0.139). No major side effects were observed. The combination of linagliptin and insulin in hospitalized patients with SARS-CoV-2 infection and hyperglycemia reduced the relative risk of assisted mechanical ventilation by 74% and improved better pre and postprandial glucose levels with lower insulin requirements, and no higher risk of hypoglycemia.This study is registered at clinicaltrials.gov, number NCT04542213 on 09/03/2020.


Assuntos
COVID-19/diagnóstico , Hiperglicemia/tratamento farmacológico , Insulina/uso terapêutico , Linagliptina/uso terapêutico , Glicemia/análise , COVID-19/complicações , COVID-19/virologia , Quimioterapia Combinada , Feminino , Hospitalização , Humanos , Hiperglicemia/complicações , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Respiração Artificial/estatística & dados numéricos , SARS-CoV-2/isolamento & purificação
11.
PLOS Glob Public Health ; 2(11): e0000782, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36962595

RESUMO

The human papillomavirus (HPV) vaccine has been proven effective in the prevention of infection with high-risk HPV types, which can lead to the development of six HPV-related cancers. Puerto Rico (PR) adopted a mandatory HPV vaccination school-entry policy that took effect in August 2018. While school-entry requirements are generally accepted as an effective approach for increasing vaccination rates, there are few studies that have documented their impact on improving HPV vaccination rates. The objective of this study was to evaluate the impact of the HPV school-entry policy in PR on HPV vaccine coverage. We used a pre-post natural experiment. The study population included adolescents registered in the PR Immunization Registry during 2008-2019. We calculated HPV vaccine initiation and up-to-date (UTD) vaccine coverage rates. We estimated age-standardized rates (ASR) and standardized rate ratio with 95%CI. Vaccine data corresponding to a total of 495,327 adolescents were included for analysis; 50.9% were male and 49.1% were females. After policy implementation, a marked increase in raw HPV vaccine initiation among 11- to 12-year-old adolescents was observed across years 2017 (a pre-policy year), 2018, and 2019 (58.3%, 76.3%, and 89.8%, respectively). UTD coverage also showed a moderate increase after policy implementation among 11- to 12-year-old adolescents. The gap between sexes in vaccine initiation and UTD coverage narrowed over time; the ASRs in 2019 showed an increase of 19% in initiation and 7% increase in UTD relative to 2017 for males and females combined (both significant at p<0.05). This study demonstrated evidence of improvement in HPV vaccination rates following implementation of the school-entry policy and a narrowed sex gap in vaccine rates over time in PR. Future analyses should assess how the policy continues to affect vaccine coverage in subsequent years and how the COVID-19 pandemic has impacted HPV vaccination uptake.

12.
Heliyon ; 7(9): e07915, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34584999

RESUMO

This research examines the spatial structure of a sample of breast cancer (BC) cases and their spatial interaction with contaminated areas in the Monterrey Metropolitan Area (MMA). By applying spatial statistical techniques that treat the space as a continuum, degrees of spatial concentration were determined for the different study groups, highlighting their concentration pattern. The results indicate that 65 percent of the BC sample had exposure to more than 56 points of PM10. Likewise, spatial clusters of BC cases of up to 39 cases were identified within a radius of 3.5 km, interacting spatially with environmental contamination sources, particularly with refineries, food processing plants, cement, and metals. This study can serve as a platform for other clinical research by identifying geographic clusters that can help focus health policy efforts.

13.
BMC Geriatr ; 21(1): 419, 2021 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-34246238

RESUMO

BACKGROUND: Functional disability continues to be a significant public health problem that increases older adults' vulnerability to experience a diminished quality of life, loss of independence, higher healthcare costs and health services utilization, and increased risks of mortality. Thus, we aimed to study the prevalence of functional disabilities by sex according to the types of daily living activities, controlling for specific sociodemographic variables among older Hispanics from low-income communities. METHODS: We used a cross-sectional epidemiological research design, considering a complex sampling design of households to interview adults ≥65 years living in low-income communities in Puerto Rico. Functional disability was measured by the PROMIS® Physical Function Short Form-20 T-score. The selected community was reported to have 5980 adult residents ≥65 years, according to the USA Census. The prevalence of functional disability was estimated using the logistic regression model, weighting by the effect of the sampling. Our estimated prevalence was compared between sexes using the prevalence ratio (PR), which was estimated with logistic regression models, controlling for age, income, number of chronic conditions, high and low impact of chronic conditions in functional disabilities, marital status, and sampling design. RESULTS: We recruited 211 older Hispanics from a randomly selected sample. Their mean age was 74.4 ± 7.1 years, with female predominance (57.3%). The overall estimated prevalence of physical function disability using T-score among females was 2.70 (95% CI: 1.4, 5.1) times the estimated prevalence of physical function disability among males. Women were more likely to report functional disabilities in instrumental activities of daily living, self-care activities, and functional mobility compared to males. However, sex differences were largely explained by the presence of musculoskeletal conditions of high impact in functional disability. CONCLUSIONS: The females in our study bear the greater burden of physical function disability in their adult age. Health policies, as well as future studies, should be targeted at reducing the burden of physical function disabilities in different types of daily activities through gender-sensitive disability self-management programs.


Assuntos
Atividades Cotidianas , Pessoas com Deficiência , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Prevalência , Qualidade de Vida
14.
Cochrane Database Syst Rev ; 7: CD010783, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34313331

RESUMO

BACKGROUND: Dementia is a progressive global cognitive impairment syndrome. In 2010, more than 35 million people worldwide were estimated to be living with dementia. Some people with mild cognitive impairment (MCI) will progress to dementia but others remain stable or recover full function. There is great interest in finding good predictors of dementia in people with MCI. The Mini-Mental State Examination (MMSE) is the best-known and the most often used short screening tool for providing an overall measure of cognitive impairment in clinical, research and community settings. OBJECTIVES: To determine the accuracy of the Mini Mental State Examination for the early detection of dementia in people with mild cognitive impairment SEARCH METHODS: We searched ALOIS (Cochrane Dementia and Cognitive Improvement Specialized Register of diagnostic and intervention studies (inception to May 2014); MEDLINE (OvidSP) (1946 to May 2014); EMBASE (OvidSP) (1980 to May 2014); BIOSIS (Web of Science) (inception to May 2014); Web of Science Core Collection, including the Conference Proceedings Citation Index (ISI Web of Science) (inception to May 2014); PsycINFO (OvidSP) (inception to May 2014), and LILACS (BIREME) (1982 to May 2014). We also searched specialized sources of diagnostic test accuracy studies and reviews, most recently in May 2014: MEDION (Universities of Maastricht and Leuven, www.mediondatabase.nl), DARE (Database of Abstracts of Reviews of Effects, via the Cochrane Library), HTA Database (Health Technology Assessment Database, via the Cochrane Library), and ARIF (University of Birmingham, UK, www.arif.bham.ac.uk). No language or date restrictions were applied to the electronic searches and methodological filters were not used as a method to restrict the search overall so as to maximize sensitivity. We also checked reference lists of relevant studies and reviews, tracked citations in Scopus and Science Citation Index, used searches of known relevant studies in PubMed to track related articles, and contacted research groups conducting work on MMSE for dementia diagnosis to try to locate possibly relevant but unpublished data. SELECTION CRITERIA: We considered longitudinal studies in which results of the MMSE administered to MCI participants at baseline were obtained and the reference standard was obtained by follow-up over time. We included participants recruited and clinically classified as individuals with MCI under Petersen and revised Petersen criteria, Matthews criteria, or a Clinical Dementia Rating = 0.5. We used acceptable and commonly used reference standards for dementia in general, Alzheimer's dementia, Lewy body dementia, vascular dementia and frontotemporal dementia. DATA COLLECTION AND ANALYSIS: We screened all titles generated by the electronic database searches. Two review authors independently assessed the abstracts of all potentially relevant studies. We assessed the identified full papers for eligibility and extracted data to create two by two tables for dementia in general and other dementias. Two authors independently performed quality assessment using the QUADAS-2 tool. Due to high heterogeneity and scarcity of data, we derived estimates of sensitivity at fixed values of specificity from the model we fitted to produce the summary receiver operating characteristic curve. MAIN RESULTS: In this review, we included 11 heterogeneous studies with a total number of 1569 MCI patients followed for conversion to dementia. Four studies assessed the role of baseline scores of the MMSE in conversion from MCI to all-cause dementia and eight studies assessed this test in conversion from MCI to Alzheimer´s disease dementia. Only one study provided information about the MMSE and conversion from MCI to vascular dementia. For conversion from MCI to dementia in general, the accuracy of baseline MMSE scores ranged from sensitivities of 23% to 76% and specificities from 40% to 94%. In relationship to conversion from MCI to Alzheimer's disease dementia, the accuracy of baseline MMSE scores ranged from sensitivities of 27% to 89% and specificities from 32% to 90%. Only one study provided information about conversion from MCI to vascular dementia, presenting a sensitivity of 36% and a specificity of 80% with an incidence of vascular dementia of 6.2%. Although we had planned to explore possible sources of heterogeneity, this was not undertaken due to the scarcity of studies included in our analysis. AUTHORS' CONCLUSIONS: Our review did not find evidence supporting a substantial role of MMSE as a stand-alone single-administration test in the identification of MCI patients who could develop dementia. Clinicians could prefer to request additional and extensive tests to be sure about the management of these patients. An important aspect to assess in future updates is if conversion to dementia from MCI stages could be predicted better by MMSE changes over time instead of single measurements. It is also important to assess if a set of tests, rather than an isolated one, may be more successful in predicting conversion from MCI to dementia.


Assuntos
Disfunção Cognitiva/complicações , Demência/diagnóstico , Testes de Estado Mental e Demência , Doença de Alzheimer/diagnóstico , Demência/etiologia , Demência Vascular/diagnóstico , Demência Vascular/etiologia , Progressão da Doença , Diagnóstico Precoce , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/etiologia , Humanos , Doença por Corpos de Lewy/diagnóstico , Doença por Corpos de Lewy/etiologia , Testes Neuropsicológicos , Sensibilidade e Especificidade
15.
Ciudad de México; México. Ciencia Latina Revista Científica Multidisciplinar; 2021; 20210600. 14 p. ilus.
Monografia em Espanhol | MINSAPERÚ | ID: biblio-1284094

RESUMO

El documento contiene la revisión y el análisis de los resultados del monitoreo de los antibióticos prohibidos en producción animal para consumo humano, efectuados por el Servicio Nacional de Sanidad Agraria del Perú (SENASA): nitrofuranos (furaltadona y furazolidona) y cloranfenicol.


Assuntos
Cloranfenicol , Alimentos , Furazolidona , Antibacterianos , Nitrofuranos
16.
J Pharmacol Toxicol Methods ; 110: 107081, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34058320

RESUMO

Heterologously expressed hERG channels represent a mainstay of in vitro drug safety screens intended to mitigate risk of cardiac IKr block and sudden cardiac death. This is true even as more channel types are adopted as part of the Comprehensive in vitro Proarrhythmia Assay (CiPA) intended to elevate specificity and thus enhance throughput of promising lead drugs. Until now, hERG1a homomeric channels have been used as a proxy for IKr despite a wealth of evidence showing that hERG1a/1b heteromers better represent native channels in terms of protein abundance and channel biophysical and pharmacological properties. Past efforts to create a stable hERG1a/1b cell line were met with unpredictable silencing of hERG1b expression despite stable integration of the gene into the HEK293 cell genome. Here we report a new cell line stably expressing hERG1a, with hERG1b reliably controlled by an inducible promoter sensitive to doxycycline. Co-immunoprecipitation, Western blot analysis and patch-clamp electrophysiology confirm the heteromeric composition of the expressed channels. Association with hERG1b was found to promote hERG1a protein levels and enhance membrane current levels. Optimal conditions for drug screening and experimental investigation were achieved at 24 h exposure to 100 ng/ml doxycycline. Differences in pharmacological sensitivity between homomeric and heteromeric channels were observed for dofetilide and ebastine, but not fluoxetine, as evaluated by their IC50 values. Using these values in the O'Hara-Rudy-CiPA in silico model revealed discrepancies in pro-arrhythmia risk, implying the hERG1a homomeric platform overestimates risk for these two drugs. Dofetilide block was use-dependent and faster for hERG1a/1b than hERG1a channels, whereas ebastine showed considerable block at rest and had a slower progression for hERG1a/1b channels. The hERG1a/1b cell line thus represents an advanced model for contemporary drug safety screening assays such as CiPA that employ IC50 values to estimate risk of proarrhythmia in computational models of ventricular cardiomyocytes. This novel technology fulfills an unmet need to enhance specificity and foster a safe yet expanded drug development pipeline.


Assuntos
Arritmias Cardíacas , Canais de Potássio Éter-A-Go-Go , Canal de Potássio ERG1/genética , Canais de Potássio Éter-A-Go-Go/genética , Células HEK293 , Humanos , Miócitos Cardíacos
17.
Proc Natl Acad Sci U S A ; 118(22)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34031250

RESUMO

Infection with the flavivirus Zika virus (ZIKV) can result in tissue tropism, disease outcome, and route of transmission distinct from those of other flaviviruses; therefore, we aimed to identify host machinery that exclusively promotes the ZIKV replication cycle, which can inform on differences at the organismal level. We previously reported that deletion of the host antiviral ribonuclease L (RNase L) protein decreases ZIKV production. Canonical RNase L catalytic activity typically restricts viral infection, including that of the flavivirus dengue virus (DENV), suggesting an unconventional, proviral RNase L function during ZIKV infection. In this study, we reveal that an inactive form of RNase L supports assembly of ZIKV replication factories (RFs) to enhance infectious virus production. Compared with the densely concentrated ZIKV RFs generated with RNase L present, deletion of RNase L induced broader subcellular distribution of ZIKV replication intermediate double-stranded RNA (dsRNA) and NS3 protease, two constituents of ZIKV RFs. An inactive form of RNase L was sufficient to contain ZIKV genome and dsRNA within a smaller RF area, which subsequently increased infectious ZIKV release from the cell. Inactive RNase L can interact with cytoskeleton, and flaviviruses remodel cytoskeleton to construct RFs. Thus, we used the microtubule-stabilization drug paclitaxel to demonstrate that ZIKV repurposes RNase L to facilitate the cytoskeleton rearrangements required for proper generation of RFs. During infection with flaviviruses DENV or West Nile Kunjin virus, inactive RNase L did not improve virus production, suggesting that a proviral RNase L role is not a general feature of all flavivirus infections.


Assuntos
2',5'-Oligoadenilato Sintetase/metabolismo , Endorribonucleases/metabolismo , Interações Hospedeiro-Patógeno , Replicação Viral , Zika virus/fisiologia , 2',5'-Oligoadenilato Sintetase/genética , Células A549 , Endorribonucleases/genética , Humanos
18.
Acta neurol. colomb ; 37(1,supl.1): 81-89, mayo 2021. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1248584

RESUMO

RESUMEN La meningitis por Mycobacterium tuberculosis es la forma extrapulmonar más letal de la tuberculosis activa, con alta prevalencia en los países en desarrollo, lo que constituye un problema de salud pública. Las formas de presentación extrapulmonar que comprometen el sistema nervioso incluyen la tuberculosis meníngea, el granuloma tuberculoso, el absceso tuberculoso y la radiculomielitis, con una presentación clínica inespecífica que dificulta su oportuno diagnóstico, sumado a la falta de pruebas rápidas con alta sensibilidad y especificidad, el alto costo y la pobre asequibilidad a las pruebas en muchos países. El diagnóstico se basa en pruebas microbiológicas, moleculares y en aquellas basadas en la respuesta del huésped. El diagnóstico microbiológico se basa en la tinción de Ziehl-Neelsen y en el cultivo, este último considerado durante mucho tiempo la prueba diagnóstica de oro. El diagnóstico molecular es más preciso utilizando las pruebas de amplificación de ácidos nucleicos, la reacción en cadena de la polimerasa, la prueba de GeneXpert MTB/RIF y la prueba Xpert MTB/ RIF Ultra. Debido a la ausencia de una prueba rápida, existen escalas que ayudan a orientar el diagnóstico del paciente, dentro de las cuales merecen citarse la de Thwaites y la de Marais. El tratamiento de la tuberculosis de cepas sensibles incluye un esquema estructurado con isoniazida, rifampicina, pirazinamida y etambutol, sin embargo, en la actualidad la resistencia a los antimicrobianos constituye un problema, por lo cual el tratamiento en la tuberculosis multirresistente debe ser individualizado, con un régimen de tratamiento prolongado.


SUMMARY Mycobacterium tuberculosis meningitis is the most lethal extrapulmonary form of active tuberculosis with high prevalence in developing countries, which constitutes a public health problem. The extrapulmonary presentation that compromise the nervous system include meningeal tuberculosis, tuberculous granuloma, tuberculosis abscess and radiculomyelitis. A nonspecific clinical presentation, the lack of rapid tests with high sensitivity and specificity, the high cost and poor affordability of testing in many countries make the diagnosis more complicated. The diagnosis is based on microbiological, molecular, and host response based testing. Microbiological diagnosis is based on Ziehl - Neelsen staining and culture, the latter long considered the gold standard diagnostic test. Molecular diagnosis is more accurate using nucleic acid amplification tests, the chain reaction of polymerase, the GeneXpert MTB / RIF test, and the Xpert MTB / RIF Ultra test. Given the absence of a rapid test, there are scales that help guide the patient's diagnosis, within which the Thwaites Scale and the Marais Scale deserve to be mentioned. The treatment of tuberculosis of susceptible strains includes a structured regimen with isoniazid, rifampicin, pyrazinamide and ethambutol, however, antimicrobial resistance is currently a problem for which the treatment of multidrug-resistant tuberculosis must be individualized, with a long-term treatment regimen.


Assuntos
Mobilidade Urbana
19.
Front Microbiol ; 12: 655239, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815347

RESUMO

Failure of the cell to properly regulate the number and intracellular positioning of their flagella, has detrimental effects on the cells' swimming ability. The flagellation pattern of numerous bacteria is regulated by the NTPases FlhF and FlhG. In general, FlhG controls the number of flagella produced, whereas FlhF coordinates the position of the flagella. In the human pathogen Vibrio parahaemolyticus, its single flagellum is positioned and formed at the old cell pole. Here, we describe the spatiotemporal localization of FlhF and FlhG in V. parahaemolyticus and their effect on swimming motility. Absence of either FlhF or FlhG caused a significant defect in swimming ability, resulting in absence of flagella in a ΔflhF mutant and an aberrant flagellated phenotype in ΔflhG. Both proteins localized to the cell pole in a cell cycle-dependent manner, but displayed different patterns of localization throughout the cell cycle. FlhF transitioned from a uni- to bi-polar localization, as observed in other polarly flagellated bacteria. Localization of FlhG was strictly dependent on the cell pole-determinant HubP, while polar localization of FlhF was HubP independent. Furthermore, localization of FlhF and FlhG was interdependent and required for each other's proper intracellular localization and recruitment to the cell pole. In the absence of HubP or FlhF, FlhG forms non-polar foci in the cytoplasm of the cell, suggesting the possibility of a secondary localization site within the cell besides its recruitment to the cell poles.

20.
World J Urol ; 39(7): 2669-2675, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32944804

RESUMO

PURPOSE: To critically evaluate a multi-institutional patient cohort undergoing Dorsal-Onlay Buccal Mucosal Graft Urethroplasty (D-BMGU) for recurrent post-radiation posterior urethral stenosis. METHODS: Retrospective multi-institutional review of patients with posterior urethral stenosis from 10 institutions between 2010-2019 was performed. Patients with at least 1-year follow-up were assessed. Patient demographics, stenosis characteristics, peri-operative outcomes, and post-operative clinical and patient-reported outcomes were analyzed. The primary outcomes were stenosis recurrence and de-novo stress urinary incontinence (SUI). Secondary outcomes were changes in voiding, sexual function, and patient-reported satisfaction. RESULTS: Seventy-nine men with post-radiation urethral stenosis treated with D-BMGU met inclusion criteria. Median age and stenosis length were 72 years, (IQR 66-75), and 3.0 cm (IQR 2.5-4 cm), respectively. Radiation modalities included: 36 (45.6%) external beam radiotherapy (EBRT), 13 (16.5%) brachytherapy (BT), 10 (12.7%) combination EBRT/BT, and 20 (25.3%) EBRT/radical prostatectomy. At a median follow-up of 21 months (IQR 13-40), 14 patients (17.7%) had stenosis recurrence. Among 37 preoperatively-continent patients, 3 men (8.1%) developed de-novo SUI following dorsal onlay urethroplasty. Of 29 patients with preoperative SUI all but one remained incontinent post-operatively (96.6%). Following repair, patients experienced significant improvement in PVR (92.5 to 26 cc, p = 0.001) and Uroflow (4.6 to 15.9 cc/s, p = 0.001), and high overall satisfaction, with 91.9% reporting a GRA of + 2 or better). CONCLUSION: Dorsal onlay buccal mucosa graft urethroplasty is a safe and feasible technique in patients with post-radiation posterior urethral stenosis. This non-transecting approach may confer low rates of de-novo SUI. Further research is needed to compare this technique with excisional urethroplasty.


Assuntos
Mucosa Bucal/transplante , Lesões por Radiação/cirurgia , Uretra/cirurgia , Estreitamento Uretral/etiologia , Estreitamento Uretral/cirurgia , Idoso , Humanos , Masculino , Recidiva , Estudos Retrospectivos , Procedimentos Cirúrgicos Urológicos Masculinos/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...