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1.
Front Med (Lausanne) ; 11: 1383252, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38835792

RESUMO

Objective: To investigate the clinical characteristics and risk factors of patients with SARS-CoV-2 Omicron variant infection complicated with cardiovascular diseases. Methods: A retrospective analysis of general clinical data was conducted on patients with SARS-CoV-2 omicron infection complicated with hypertension, coronary heart disease, and heart failure admitted to one hospital in Guangdong Province from December 1, 2022, to February 28, 2023. Clinical symptoms, laboratory tests, imaging examinations, treatment, and clinical outcomes were collected. Multivariate logistic regression analysis was used to analyze the risk factors for mortality in patients with SARS-CoV-2 Omicron variant infection complicated with cardiovascular diseases. ROC curves were drawn to evaluate the predictive value of CRP, D-dimer, and CK-MB in predicting the risk of death. Results: A total of 364 confirmed cases were included, divided into the asymptomatic group, mild to moderate group, and severe to critically ill group based on the symptoms of COVID-19. There were 216 males (59.34%) and 148 females (40.66%), with a median age of 75 years. The differences between the three groups in terms of sex and age were statistically significant (p < 0.05). The top three underlying diseases were hypertension (288 cases, 79.12%), coronary heart disease (100 cases, 27.47%), and diabetes (84 cases, 23.08%). The differences in unvaccinated and triple-vaccinated patients among the three groups were statistically significant (p < 0.05). The common respiratory symptoms were cough in 237 cases (65.11%) and sputum production in 199 cases (54.67%). In terms of laboratory tests, there were statistically significant differences in neutrophils, lymphocytes, red blood cells, C-reactive protein, D-dimer, aspartate aminotransferase, and creatinine among the three groups (p < 0.05). In imaging examinations, there were statistically significant differences among the three groups in terms of unilateral pulmonary inflammation, bilateral pulmonary inflammation, and bilateral pleural effusion (p < 0.05). There were statistically significant differences among the three groups in terms of antibiotic treatment, steroid treatment, oxygen therapy, nasal cannula oxygen inhalation therapy, non-invasive ventilation, and tracheal intubation ventilation (p < 0.05). Regarding clinical outcomes, there were statistically significant differences among the three groups in terms of mortality (p < 0.05). Multivariate logistic regression analysis showed that CRP (OR = 1.012, 95% CI = 1.004-1.019) and D-dimer (OR = 1.117, 95% CI = 1.021-1.224) were independent risk factors for patient mortality. The predictive value of CRP, D-dimer, and CK-MB for the risk of death was assessed. D-dimer had the highest sensitivity (95.8%) in predicting patient mortality risk, while CRP had the highest specificity (84.4%). Conclusion: For patients with COVID-19 and concomitant cardiovascular diseases without contraindications, early administration of COVID-19 vaccines and booster shots can effectively reduce the mortality rate of severe cases. Monitoring biomarkers such as CRP, D-dimer, and CK-MB and promptly providing appropriate care can help mitigate the risk of mortality in patients.

2.
Front Med (Lausanne) ; 10: 1229794, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780575

RESUMO

Objective: The objective of this study was to analyze the clinical characteristics of pregnant women infected with the COVID-19 omicron variant and their neonates during the outbreak in Guangdong province, China. Methods: The clinical data of pregnant women infected with the COVID-19 omicron variant and their neonates were retrospectively collected from two hospitals in Guangdong province. Information recorded included age of mother, date of birth, sex, weight at birth, mode of delivery, gestational age, feeding mode, Apgar score, signs, medical records, underlying comorbidities and laboratory results. The presence of SARS-CoV-2 viral RNA was tested using an real-time PCR assay. Results: Seventy-nine pregnant women infected with COVID-19 omicron variant and their 68 neonates were included in this study. The vast majority (86.1%) of pregnant women was in their third trimester of pregnancy, and only 11 cases (15%) were in the first or second trimester. Of 79 pregnant women, 39 cases were asymptomatic at the time of infection, and 40 mothers presented with mild manifestations of COVID-19. The most common symptoms were fever (92.5%, 37/40) and cough (57.5%, 21/40). All of pregnant women did not receive chest computed tomography (CT) scan or X-ray. No pregnant woman developed severe pneumonia. A total of 68 neonates (3 set of twins) from 65 mothers with COVID-19 were reviewed. Among women who delivered, 34 cases underwent cesarean section, 31 cases underwent vaginal delivery. According to the timing of birth, there were 10 (14.7%) preterm neonates. Two babies were born dead (intrauterine fetal death after 22 weeks of gestation). Of the live babies born (66 cases) from mothers with COVID-19, 9 newborns were lower weight, and one preterm case was born with respiratory distress and intubated, he recovered and developed normally. SARS-CoV-2 nucleic acid testing was conducted on 41 neonates daily after birth, with only one neonate testing positive for SARS-CoV-2 infection on the third day after birth. The infected neonate exhibited typical fever and acute respiratory tract syndrome but ultimately had a good prognosis, recovering after 5 days of treatment. Conclusion: Although preliminary data suggests the risk of severe maternal and fetal complications from Omicron variant infection during pregnancy is lower than previous variants and Delta variant. Our study, which was conducted on a limited population sample, indicates that there is a possibility of severe complications, such as stillbirth, occurring in some fetal cases. These findings emphasize the need for continued attention from obstetricians.

3.
Front Pediatr ; 11: 1201940, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37492600

RESUMO

Objective: Glucose 6-phosphate dehydrogenase (G6PD) deficiency increases the risk of neonatal hyperbilirubinemia. The aim of this study is to evaluate the risk factors associated with hyperbilirubinemia in infants from the western part of Guangdong Province, and to assess the contribution of G6PD deficiency to neonatal jaundice. Methods: The term infants with neonatal hyperbilirubinemia in People's Hospital of Yangjiang from June 2018 to July 2022 were recruited for the retrospective analysis. All the infants underwent quantitative detection of the G6PD enzyme. The etiology was determined through laboratory tests and clinical manifestations. Results: Out of 1,119 term infants, 435 cases presented with jaundice. For the etiology analysis, infection was responsible for 16.09% (70/435), G6PD deficiency accounted for 9.66% (42/435), of which 3 were complicated with acute bilirubin encephalopathy), bleeding accounted for 8.05% (35/435), hemolytic diseases accounted for 3.45% (15/435), and breast milk jaundice accounted for 2.53% (11/435). One case (0.23%) was attributed to congenital hypothyroidism, multiple etiologies accounted for 22.3% (97/435), and 35.63% (155/435) were of unknown etiology. Of the jaundiced infants, 19.54% (85/435) had G6PD deficiency, while only 10.23% (70/684) of non-jaundiced infants had G6PD deficiency; this difference was found to be statistically significant (P < 0.001). Furthermore, the hemoglobin levels in the jaundiced infants with G6PD deficiency (146.85 ± 24.88 g/L) were lower than those without G6PD deficiency (156.30 ± 22.07 g/L) (P = 0.001). 65 jaundiced infants with G6PD deficiency underwent G6PD mutation testing, and six different genotypes were identified, including c.95A > G, c.392G > T, c.1024C > T, c.1311C > T, c.1376G > T, c.1388G > A, c.871G > A/c.1311C > T, c.392G > T/c.1388G > A, and c.1376G > T/c.1311C > T.65iciency. Conclusion: In newborns in Yangjiang, G6PD deficiency, infection, and neonatal hemolytic disease were identified as the main causes of hyperbilirubinemia and acute bilirubin encephalopathy. Specifically, Hemolytic factors in infants with G6PD deficiency may lead to reduced hemoglobin and increased bilirubin levels in jaundiced infants.

4.
Front Pediatr ; 11: 1191651, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37416819

RESUMO

Objective: To analyze the clinical characteristics of neonatal infection during the outbreak of COVID-19 omicron variant in Guangdong province of China. Method: The clinical data of neonates infected with COVID-19 omicron variant were collected from three hospitals of Guangdong province, their epidemiological history, clinical manifestation and prognosis were summarized. Results: From December 12, 2022 to January 15, 2023, a total of 52 neonates with COVID-19 infection were identified across three hospitals in Guangdong Province, including 34 males and 18 females. The age of diagnosis was 18.42 ± 6.32 days. 24 cases had clear contact history with adults who were suspected to be infected with COVID-19. The most common clinical manifestation was fever (43/52, 82.7%), the duration of fever was 1-8 days. The other clinical manifestations were cough (27/52, 51.9%), rales (21/52, 40.4%), nasal congestion (10/52, 19.2%), shortness of breath (2/52, 3.8%), and vomiting (4/52, 7.7%). C-reactive protein was only increased in 3 cases. Chest radiological examination was performed in 42 neonates, twenty-three cases showed abnormal chest radiographic findings, including ground-glass opacity and consolidation. Fifty cases were admitted with COVID-19 presentation, two cases were admitted for jaundice. The hospital stay was 6.59 ± 2.77 days. The clinical classification included 3 cases of severe COVID-19 and one critical case. Fifty-one cases were cured and discharged after general treatment, and one critical case with respiratory failure was intubated and transferred to another hospital. Conclusion: The COVID-19 omicron variant infection in neonates is usually mild. The clinical manifestation and laboratory results are not specific, and the short-term prognosis is good.

5.
Front Genet ; 14: 1126099, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36861132

RESUMO

Background: Thalassemia presents a higher incidence in southern China. The objective of this study is to analyze the genotype distribution of thalassemia in Yangjiang, a western city of Guangdong Province in China. Methods: The genotypes of suspected cases with thalassemia were tested by PCR and reverse dot blot (RDB). Unidentified rare thalassemia genotypes of the samples were further ascertained by PCR and direct DNA sequencing. Results: Among 22467 suspected cases with thalassemia, 7658 cases were found with thalassemia genotypes using our PCR-RDB kit. Among these 7658 cases, 5313 cases were found with α-thalassemia (α-thal) alone, --SEA/αα was the most common genotype, accounting for 61.75% of α-thal genotypes, and the following mutations were found: α3.7/αα, -α4.2/αα, αCSα/αα, αWSα/αα, and αQSα/αα. A total of 2032 cases were found with ß-thalassemia (ß-thal) alone. ßCD41-42/ßN, ßIVS-II-654/ßN, and ß-28/ßN accounted for 80.9% of all ß-thal genotypes, and the following genotypes were found: ßCD17/ßN, ßCD71-72/ßN, and ßE/ßN. Compound heterozygotes of ß-thal and ß-thalassemia homozygotes were identified in 11 and five cases, respectively, in this study. α-thal combined with ß-thal was identified in 313 cases, showing 57 genotype combinations of the coincidence of both Hb disorders; one extreme patient had a genotype of --SEA/αWSα and ßCD41-42/ß-28. In addition, four rare α-mutations (--THAI, HKαα, Hb Q-Thailand, and CD31 AGG>AAG) and six rare ß-mutations (CD39 CAG>TAG, IVS-Ⅱ-2 (-T), -90(C>T), Chinese Gγ+(Aγδß)0, CD104 (-G), and CD19 A>G) were also found in this study population. Conclusion: This study provided detailed genotypes of thalassemia in Yangjiang of western Guangdong Province in China and reflected the complexity of genotypes in this high-prevalence region, and this would be valuable for diagnosis and counseling for thalassemia in this area.

6.
Sci Adv ; 9(4): eabp8943, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36696496

RESUMO

Exceptional points (EPs), at which more than one eigenvalue and eigenvector coalesce, are unique spectral features of non-Hermiticity (NH) systems. They exist widely in open systems with complex energy spectra. We experimentally demonstrate the appearance of paired EPs in a periodical-driven degenerate optical cavity along the synthetic orbital angular momentum dimension with a tunable parameter. The complex-energy band structures and the key features of EPs, i.e., their bulk Fermi arcs, parity-time symmetry breaking transition, energy swapping, and half-integer band windings, are directly observed by detecting the wavefront angle-resolved transmission spectrum. Our results demonstrate the flexibility of using the photonic synthetic dimensions to implement NH systems beyond their geometric dimension and EP-based sensing.

7.
Front Genet ; 14: 1345537, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38264207

RESUMO

Objectives: The prevalence of G6PD deficiency has not been reported in Yangjiang, a western city in Guangdong province. This study aims to investigate the molecular characteristics of G6PD deficiency in this region. Methods: Blood samples were collected from adults at a local hospital to screen for G6PD deficiency. The deficient samples were subjected to further analysis using PCR and reverse dot blot to determine the specific G6PD variants. Results: Among the 3314 male subjects, 250 cases of G6PD deficiency were found using the G6PD enzyme quantitative assay, resulting in a prevalence of 7.54% (250/3314) in the Yangjiang region. The prevalence of G6PD deficiency in females was 3.42% (176/5145). Out of the 268 cases of G6PD deficiency tested for G6PD mutations, reverse dot blot identified 20 different G6PD variants. The most common G6PD variant was c.1388G>A (81/268), followed by c.1376G>T (48/268), c.95A>G (32/268), c.1024C>T (9/268), c.392G>T (7/268), and c.871G>A/c.1311C>T (6/268). It was observed that c.871G>A was always linked to the polymorphism of c.1311C>T in this population. Conclusion: This investigation into G6PD deficiency in this area is expected to significantly improve our understanding of the prevalence and molecular characterization of this condition.

8.
Nat Commun ; 13(1): 2040, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440661

RESUMO

Synthetic dimensions based on particles' internal degrees of freedom, such as frequency, spatial modes and arrival time, have attracted significant attention. They offer ideal large-scale lattices to simulate nontrivial topological phenomena. Exploring more synthetic dimensions is one of the paths toward higher dimensional physics. In this work, we design and experimentally control the coupling among synthetic dimensions consisting of the intrinsic photonic orbital angular momentum and spin angular momentum degrees of freedom in a degenerate optical resonant cavity, which generates a periodically driven spin-orbital coupling system. We directly characterize the system's properties, including the density of states, energy band structures and topological windings, through the transmission intensity measurements. Our work demonstrates a mechanism for exploring the spatial modes of twisted photons as the synthetic dimension, which paves the way to design rich topological physics in a highly compact platform.

9.
IEEE Trans Neural Syst Rehabil Eng ; 24(12): 1405-1415, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26955041

RESUMO

We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory.


Assuntos
Braço/fisiologia , Terapia por Estimulação Elétrica/métodos , Modelos Biológicos , Modelos Estatísticos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Membros Artificiais , Simulação por Computador , Terapia por Estimulação Elétrica/instrumentação , Retroalimentação Fisiológica , Humanos , Músculo Esquelético/inervação , Reabilitação Neurológica/instrumentação , Reabilitação Neurológica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Terapia Assistida por Computador/instrumentação , Terapia Assistida por Computador/métodos
10.
Nature ; 528(7583): 523-5, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26633633

RESUMO

Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

11.
Pancreas ; 44(3): 507-11, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25723878

RESUMO

OBJECTIVE: The present retrospective study aimed to analyze the optimal time to initiate enteral nutrition (EN) in patients with severe acute pancreatitis at a single Chinese institution (China Medical University Hospital). METHODS: A total of 1196 patients with severe acute pancreatitis were admitted in the intensive care unit between November 2003 and June 2013; 1092 patients were selected and were divided into the early and delayed EN groups, according to their initial timing of EN. RESULTS: Five hundred sixty-six patients were administered with the delayed EN, and 526 with the early EN. Both groups had similar severity of pancreatic necrosis, but organ failure developed in 81% patients of the delayed EN group and 21% in the early EN group (P < 0.01). The numbers of septic necrosis and morbidity were significantly higher in the delayed EN group than in the early EN (P < 0.01). CONCLUSIONS: The early EN had significant benefits over the delayed EN in the decrease of organ failure and mortality; our findings suggested that the first 48 hours of administration in the intensive care unit was the optimal time to start EN.


Assuntos
Nutrição Enteral , Pancreatite Necrosante Aguda/terapia , Tempo para o Tratamento , Adolescente , Adulto , Idoso , China , Nutrição Enteral/efeitos adversos , Nutrição Enteral/mortalidade , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/etiologia , Insuficiência de Múltiplos Órgãos/mortalidade , Pancreatite Necrosante Aguda/complicações , Pancreatite Necrosante Aguda/diagnóstico , Pancreatite Necrosante Aguda/mortalidade , Pancreatite Necrosante Aguda/cirurgia , Projetos Piloto , Estudos Retrospectivos , Fatores de Risco , Sepse/etiologia , Sepse/mortalidade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
12.
IEEE Trans Neural Syst Rehabil Eng ; 22(3): 654-63, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24122573

RESUMO

We present a method for controlling a neuroprosthesis for a paralyzed human arm using functional electrical stimulation (FES) and characterize the errors of the controller. The subject has surgically implanted electrodes for stimulating muscles in her shoulder and arm. Using input/output data, a model mapping muscle stimulations to isometric endpoint forces measured at the subject's hand was identified. We inverted the model of this redundant and coupled multiple-input multiple-output system by minimizing muscle activations and used this inverse for feedforward control. The magnitude of the total root mean square error over a grid in the volume of achievable isometric endpoint force targets was 11% of the total range of achievable forces. Major sources of error were random error due to trial-to-trial variability and model bias due to nonstationary system properties. Because the muscles working collectively are the actuators of the skeletal system, the quantification of errors in force control guides designs of motion controllers for multi-joint, multi-muscle FES systems that can achieve arbitrary goals.


Assuntos
Braço/fisiologia , Membros Artificiais , Estimulação Elétrica/métodos , Próteses Neurais , Algoritmos , Feminino , Humanos , Contração Isométrica/fisiologia , Pessoa de Meia-Idade , Modelos Estatísticos , Desenho de Prótese , Traumatismos da Medula Espinal/reabilitação
13.
Biochem Cell Biol ; 91(6): 449-54, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24219287

RESUMO

The airway epithelial barrier function is important in maintaining the homeostasis in the body. A number of airway disorders are associated with the epithelial barrier dysfunction. The present study aims to elucidate a possible mechanism by which the proteolytic allergens compromise the epithelial barrier function. The airway epithelial cell line, RPMI 2650 cells (Rp cells) and kidney epithelial cell line, MDCK cells, were cultured to be monolayers and used as an in vitro epithelial barrier model. House dust mite antigen, Der P1 (Der) was used as an antigen that has the proteolytic property. The epithelial barrier permeability and transepithelial resistance (TER) were used as the indicators of epithelial barrier function. Both epithelial cell lines could endocytose Der in the culture. Some of the Der was transported across the epithelial barrier to the basal chambers of the Transwells without affecting the TER. The endocytic Der could suppress the expression of ubiquitin E3 lases A20 and further interfered with the fusion of endosome/lysosome in the epithelial cells. Mite antigen, Der, can interfere with the fusion of endosome/lysosome in epithelial cells to induce the epithelial barrier dysfunction.


Assuntos
Antígenos de Dermatophagoides/farmacologia , Proteínas de Artrópodes/farmacologia , Cisteína Endopeptidases/farmacologia , Endossomos/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Fusão de Membrana/efeitos dos fármacos , Mucosa Respiratória/efeitos dos fármacos , Animais , Transporte Biológico , Linhagem Celular , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Cães , Endocitose , Endossomos/metabolismo , Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lisossomos/metabolismo , Células Madin Darby de Rim Canino , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Permeabilidade , Proteólise , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa
14.
Artigo em Inglês | MEDLINE | ID: mdl-24110508

RESUMO

Functional electrical stimulation (FES) can be used to restore movement control following paralysis. For complex multijoint systems, it is becoming increasingly apparent that closed-loop controllers are needed. Designing a closed-loop control system is easiest when the open-loop system is stable. In this study we developed a computational model to assess the open-loop stability of FES-control systems. We used the model to examine the open-loop stability of the human arm throughout its reachable workspace. For each simulated position of the hand we examined the stability of the arm, assuming that a minimal pattern of muscle activation was used to support the arm against gravity. Only muscles available to an existing FES user were considered. We found that with this reduced muscle set, the stability of the arm was severely compromised. We also demonstrated that muscle co-contraction can be an effective method to improve the stability for many postures.


Assuntos
Braço/fisiologia , Estimulação Elétrica , Modelos Biológicos , Próteses Neurais , Fenômenos Biomecânicos , Mãos/fisiologia , Humanos , Movimento , Músculos/fisiologia , Postura , Recuperação de Função Fisiológica
15.
J Biomed Sci ; 20: 68, 2013 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-24028494

RESUMO

BACKGROUND: Epithelial barrier dysfunction is associated with the pathogenesis of a number of immune inflammations; the etiology is not fully understood. The fusion of endosome/lysosome is a critical process in the degradation of endocytic antigens in epithelial cells. Recent reports indicate that myosin VI (myo6) is involved in the activities of endosomes. The present study aims to investigate the role of myo6 in epithelial barrier dysfunction. RESULTS: The endosome accumulation was observed in myo6-deficient Rmcs. More than 80% endosomes were fused with lysosomes in naïve Rmcs while less than 30% endosomes were fused with lysosomes in the myo6-deficient Rmcs. The myo6-deficient Rmc monolayers showed high permeability to a macromolecular antigen, ovalbumin, the latter still conserved the antigenicity, which induced strong T cell activation. CONCLUSIONS: We conclude that myo6 plays a critical role in the fusion of endosome/lysosome in Rmc epithelial cells. Deficiency of myo6 compromises the epithelial barrier function.


Assuntos
Endossomos/metabolismo , Células Epiteliais/metabolismo , Lisossomos/metabolismo , Cadeias Pesadas de Miosina/genética , Animais , Linhagem Celular , Humanos , Camundongos , Cadeias Pesadas de Miosina/metabolismo
16.
Cytokine ; 59(1): 59-64, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22579114

RESUMO

BACKGROUND AND AIMS: Measles infection causes immune suppression that contributes to morbidity and mortality of the patients; the mechanism is poorly understood. Regulatory T cells (Treg) play a critical role in immune suppression. Integrin alphavbeta6 (avb6) is associated with Treg's function. This study aims to investigate into the mechanism by which measles C protein (MVP)-induced avb6 contributes the generation of Tregs in the lung. METHOD: MVP was introduced to mouse lung by nasal drops. The expression of avb6 by lung tissue was examined by reverse transcription polymerase chain reaction and Western blotting. The development of tolerogenic dendritic cells (DC) and Tregs in the lung and their functions was examined by flow cytometry. The suppressor function of MVP-induced Tregs was examined by cell culture models. RESULTS: The exposure to MVP markedly increased the expression of avb6 in the lung epithelial cells. Administration of MVP significantly suppressed the levels of IL-4 and IFNγ as well as increases in Tregs in lung tissue. DCs captured the MVP in the lung and differentiate into tolerogenic DCs; the latter has the ability to induce Treg development in the lung. Activation of MVP-induced Tregs powerfully suppressed polarized CD4(+) T cells. CONCLUSIONS: Exposure to MVP can induce Treg development in the lung that plays an important role in the suppression of CD4(+) T cell function.


Assuntos
Antígenos de Neoplasias/metabolismo , Tolerância Imunológica/imunologia , Integrinas/metabolismo , Pulmão/imunologia , Pulmão/virologia , Proteínas Virais/imunologia , Animais , Células Dendríticas/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Reguladores/imunologia , Proteínas Virais/administração & dosagem
17.
Artigo em Inglês | MEDLINE | ID: mdl-23365897

RESUMO

A major challenge in controlling multiple-input multiple output functional electrical stimulation systems is the large amount of time required to identify a workable system model due to the high dimensionality of the space of inputs. To address this challenge we are exploring optimal methods to sample the input space. In this paper we present two methods for optimally sampling isometric muscle force recruitment curves. One method maximizes the information about the recruitment curve parameters, and the second method minimizes the average variance of the predicted output force. We compared these methods to two previously-used methods in simulation. The simulation model was identified from recruitment data collected during experiments with a human subject with a high spinal cord injury. The optimal sampling methods on average produced estimates of the output force with less error than the two previously-used methods. The optimal sampling methods require fewer system identification experiments to identify models with similar output prediction accuracy.


Assuntos
Simulação por Computador , Terapia por Estimulação Elétrica/métodos , Contração Isométrica , Modelos Biológicos , Músculo Esquelético/fisiopatologia , Traumatismos da Medula Espinal , Bases de Dados Factuais , Humanos , Valor Preditivo dos Testes , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia
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