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1.
PLoS One ; 19(6): e0303694, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38870188

RESUMO

OBJECTIVE: This study investigates the association between physical exercise and emotion regulation abilities among college students, introducing self-efficacy as a mediating variable to analyze the pathway mechanism through which physical exercise affects emotion regulation abilities. METHODS: A cross-sectional study design was employed, utilizing a stratified random sampling method to survey three colleges in Jiangsu Province, China. Physical Activity Rating Scale, Physical Activity Self-efficacy Scale, and Emotional Intelligence Scale were used to measure the college student population. Regression analysis and mediation tests assessed whether self-efficacy mediates the relationship between physical exercise and college students' emotion regulation abilities. A total of 5,430 valid questionnaires were collected. RESULTS: The distribution of college students' physical activities was 77.0% for low, 13.1% for medium, and 9.3% for high levels. Physical activities were significantly and positively correlated with self-efficacy and emotional management abilities (r = 0.298,0.105;P<0.01), and self-efficacy was significantly and positively correlated with emotional management abilities (r = 0.322, P<0.01). Situational motivation and subjective support under self-efficacy were 0.08 and 0.255, respectively, and the adjusted R2 was 0.107. Self-efficacy played a fully mediating role between physical activities and emotional management abilities, with a total effect value of 0.032. The values of the direct and indirect effects were 0.003 and 0.029, accounting for 8.95% and 90.74% of the total effect, respectively. CONCLUSION: The physical exercise behavior of college students is primarily characterized by low intensity. Physical exercise among college students can positively predict their ability to regulate emotions. Self-efficacy fully mediates the relationship between physical exercise and emotion regulation ability among college students. College students can indirectly influence their ability to regulate emotions through physical exercise and self-efficacy.


Assuntos
Afeto , Regulação Emocional , Exercício Físico , Autoeficácia , Estudantes , Humanos , Exercício Físico/psicologia , Exercício Físico/fisiologia , Masculino , Feminino , Adulto Jovem , Regulação Emocional/fisiologia , Estudantes/psicologia , Estudos Transversais , Afeto/fisiologia , Adulto , Inquéritos e Questionários , Adolescente , Universidades , China , Emoções/fisiologia
2.
Front Public Health ; 12: 1402801, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765486

RESUMO

Background: Negative emotions in college students are a significant factor affecting mental health, with suicide behaviors caused by negative emotions showing an annual increasing trend. Existing studies suggest that physical exercise is essential to alleviate negative feelings, yet the intrinsic mechanisms by which it affects negative emotions have not been fully revealed. Objective: Negative emotions in college students represent a significant issue affecting mental health. This study investigates the relationship between physical exercise and negative emotions among college students, incorporating sleep quality and self-rated health (SRH) as mediators to analyze the pathway mechanism of how physical exercise affects students' negative emotions. Methods: A cross-sectional study design was utilized, employing online questionnaires for investigation. The scales included the Physical Activity Rating Scale-3 (PARS-3), the Depression Anxiety Stress Scales-21 (DASS-21), the Pittsburgh Sleep Quality Index (PSQI), and the 12-Item Short Form Health Survey (SF-12), resulting in the collection of 30,475 valid questionnaires, with a validity rate of 91%. Chain mediation tests and Bootstrap methods were applied for effect analysis. Results: The proportions of university students engaged in low, medium, and high levels of physical exercise were 77.6, 13.1, and 9.3%, respectively. The proportions of students experiencing "very severe" levels of stress, anxiety, and depression were 4.5, 10.9, and 3.6%, respectively. Physical exercise was significantly positively correlated with self-rated health (r = 0.194, p < 0.01), significantly negatively correlated with sleep quality (r = -0.035, p < 0.01), and significantly negatively correlated with stress, anxiety, and depression (r = -0.03, p < 0.01; r = -0.058, p < 0.01; r = -0.055, p < 0.01). Sleep quality was significantly negatively correlated with self-rated health (r = -0.242, p < 0.01). Mediation effect testing indicated that sleep quality and self-rated health partially mediated the relationship between physical exercise and negative emotions, with total effect, total direct effect, and total indirect effect values of -1.702, -0.426, and - 1.277, respectively. Conclusion: College students primarily engage in low-intensity physical activity. Sleep quality and self-rated health mediate the impact of physical exercise on students' negative emotions. A certain level of physical activity can directly affect students' emotional states and indirectly influence their negative emotions via sleep and self-rated health. Regular engagement in physical activities primarily positively impacts emotional states by enhancing mood stability and overall emotional resilience.


Assuntos
Emoções , Exercício Físico , Qualidade do Sono , Estudantes , Humanos , Masculino , Estudantes/psicologia , Feminino , Exercício Físico/psicologia , Estudos Transversais , Universidades , Inquéritos e Questionários , Adulto Jovem , Emoções/fisiologia , Adulto , Adolescente , Depressão/psicologia , Nível de Saúde , Saúde Mental
3.
Sensors (Basel) ; 23(16)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37631664

RESUMO

Fiber-optic magnetic field sensors have garnered considerable attention in the field of marine monitoring due to their compact size, robust anti-electromagnetic interference capabilities, corrosion resistance, high sensitivity, ease of multiplexing and integration, and potential for large-scale sensing networks. To enable the detection of marine magnetic field vector information, we propose an optical fiber vector magnetic field sensor that integrates three single-axis sensors in an orthogonal configuration. Theoretical analysis and experimental verification are conducted to investigate its magnetic field and temperature sensing characteristics, and a sensitivity matrix is established to address the cross-sensitivity between the magnetic field and temperature; experimental tests were conducted to assess the vector response of the three-dimensional (3D) vector sensor across the three orthogonal axes; the obtained experimental results illustrate the commendable magnetic field vector response exhibited by the sensor in the orthogonal axes, enabling precise demodulation of vector magnetic field information. This sensor presents several advantages, including cost-effectiveness, easy integration, and reliability vectorially. Consequently, it holds immense potential for critical applications in marine magnetic field network detection.

4.
Opt Express ; 31(10): 16795-16811, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37157751

RESUMO

Metal coatings can protect the fragile optical fiber sensors and extend their life in harsh environments. However, simultaneous high-temperature strain sensing in a metal-coated optical fiber remains relatively unexplored. In this study, a nickel-coated fiber Bragg grating (FBG) cascaded with an air bubble cavity Fabry-Perot interferometer (FPI) fiber optic sensor was developed for simultaneous high temperature and strain sensing. The sensor was successfully tested at 545 °C for 0-1000 µÉ›, and the characteristic matrix was used to decouple temperature and strain. The metal layer allows easy attachment to metal surfaces that operate at high temperatures, enabling sensor-object integration. As a result, the metal-coated cascaded optical fiber sensor has the potential to be used in real-world structural health monitoring.

5.
Hum Genomics ; 15(1): 38, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34187569

RESUMO

BACKGROUND: Acute myeloid leukemia (AML) is recognized as a hematological neoplasm with heterogenetic cytology and short-term outcome. HCP5 has been proven to be related with the pathogenesis of AML. However, the underlying mechanism of HCP5 in AML remains unclear. METHODS: Clinical profiles of AML patients were downloaded from TCGA and GTEx databases. LncBase and TargetScan online tools were utilized to predict potential targets, and dual-luciferase reporter assay was performed to verify the association between miR-1291 and HCP5 or PIK3R5. Cell Counting Kit 8 and flow cytometry tests were implemented to evaluate the effects of HCP5/miR-1291/PIK3R5 axis in AML cells. Quantitative RT-PCR and Western blot were conducted to detect the expression levels of genes. RESULTS: HCP5 and PIK3R5 were significantly increased in AML tissue samples compared with healthy controls. HCP5 facilitated AML cells viability and inhibited apoptosis. There was a positive relationship between HCP5 and PIK3R5, but miR-1291 negatively regulated PIK3R5. Overexpression of PIK3R5 enhanced the promoting effect of HCP5 in the development of AML, while weakened the suppression of miR-1291 to AML progression. CONCLUSION: Our findings manifested that HCP5 was remarkably upregulated in AML and upregulated HCP5 promoted the malignant behaviors of AML cells by mediating miR-1291/PIK3R5 axis, which would provide a new insight for the treatment of AML.


Assuntos
Leucemia Mieloide Aguda/genética , MicroRNAs/genética , Fosfatidilinositol 3-Quinase/genética , RNA Longo não Codificante/genética , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/patologia , Transdução de Sinais/genética
6.
Lancet Haematol ; 8(4): e289-e298, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33770484

RESUMO

BACKGROUND: Primary immune thrombocytopenia is an autoimmune bleeding disorder. Preclinical reports suggest that the sialidase inhibitor oseltamivir induces a platelet response in the treatment of immune thrombocytopenia. This study investigated the activity and safety of dexamethasone plus oseltamivir versus dexamethasone alone as initial treatment in adult patients with primary immune thrombocytopenia. METHODS: This multicentre, randomised, open-label, parallel group, phase 2 trial was done in five tertiary medical hospitals in China. Eligible patients were aged 18 years or older with newly diagnosed, treatment-naive primary immune thrombocytopenia. Participants were randomly assigned (1:1), using block randomisation, to receive either dexamethasone (orally at 40 mg per day for 4 days) plus oseltamivir (orally at 75 mg twice a day for 10 days) or dexamethasone monotherapy (orally at 40 mg a day for 4 days). Patients who did not respond to treatment (platelet counts remained <30 × 109 cells per L or showed bleeding symptoms by day 10) were given an additional cycle of dexamethasone for 4 days in each group. Patients in the dexamethasone plus oseltamivir group who relapsed (platelet counts reduced again to <30 × 109 cells per L) after an initial response were allowed a supplemental course of oseltamivir (75 mg twice a day for 10 days). The coprimary endpoints were 14-day initial overall response and 6-month overall response. Complete response was defined as a platelet count at or above 100 × 109 cells per L and an absence of bleeding. Partial response was defined as a platelet count at or above 30 × 109 cells per L but less than 100 × 109 cells per L and at least a doubling of the baseline platelet count and an absence of bleeding. A response lasting for at least 6 months without any additional primary immune thrombocytopenia-specific intervention was defined as sustained response. All patients who were randomly assigned and received the allocated intervention were included in the modified intention-to-treat population analysis. This study has been completed and is registered with ClinicalTrials.gov, number NCT01965626. FINDINGS: From Feb 1, 2016, to May 1, 2019, 120 patients were screened for eligibility, of whom 24 were ineligible and excluded, 96 were enrolled and randomly assigned to receive dexamethasone plus oseltamivir (n=47) or dexamethasone (n=49), and 90 were included in the modified intention-to-treat analysis. Six patients did not receive the allocated intervention. Patients in the dexamethasone plus oseltamivir group had a significantly higher initial response rate (37 [86%] of 43 patients) than did those in the dexamethasone group (31 [66%] of 47 patients; odds ratio [OR] 3·18; 95 CI% 1·13-9·23; p=0·030) at day 14. The 6-month sustained response rate in the dexamethasone plus oseltamivir group was also significantly higher than that in the dexamethasone group (23 [53%] vs 14 [30%]; OR 2·17; 95 CI% 1·16-6·13; p=0·032). During the median follow-up of 8 months (IQR 5-14), two of 90 patients discontinued treatment due to serious adverse events (grade 3); one (2%) patient with general oedema in the dexamethasone plus oseltamivir group and one (2%) patient with fever in the dexamethasone group. The most frequently observed adverse events of any grade were fatigue (five [12%] of 43 in the dexamethasone plus oseltamivir group vs eight [17%] of 47 in the dexamethasone group), gastrointestinal reactions (eight [19%] vs three [6%]), insomnia (seven [16%] vs four [9%]), and anxiety (five [12%] vs three [6%]). There were no grade 4 or 5 adverse events and no treatment-related deaths. INTERPRETATION: Dexamethasone plus oseltamivir offers a readily available combination therapy in the management of newly diagnosed primary immune thrombocytopenia. The preliminary activity of this combination warrants further investigation. Multiple cycles of oseltamivir, as a modification of current first-line treatment, might be more effective in maintaining the platelet response. FUNDING: National Natural Science Foundation of China.


Assuntos
Dexametasona/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Glucocorticoides/uso terapêutico , Oseltamivir/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Administração Oral , Adulto , China/epidemiologia , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Quimioterapia Combinada/efeitos adversos , Quimioterapia Combinada/métodos , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/efeitos adversos , Feminino , Seguimentos , Glucocorticoides/administração & dosagem , Glucocorticoides/efeitos adversos , Hemorragia/epidemiologia , Humanos , Análise de Intenção de Tratamento/métodos , Masculino , Pessoa de Meia-Idade , Oseltamivir/administração & dosagem , Oseltamivir/efeitos adversos , Contagem de Plaquetas/estatística & dados numéricos , Contagem de Plaquetas/tendências , Púrpura Trombocitopênica Idiopática/imunologia , Segurança , Resultado do Tratamento
7.
Am J Hematol ; 95(12): 1542-1552, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32871029

RESUMO

We conducted a prospective, multicenter, randomized, controlled clinical trial to compare the efficacy and safety of high-dose dexamethasone (HD-DXM) plus recombinant human thrombopoietin (rhTPO), vs HD-DXM alone in newly diagnosed adult immune thrombocytopenia (ITP) patients. Enrolled patients were randomly assigned to receive DXM plus rhTPO or DXM monotherapy. Another 4-day course of DXM was repeated if response was not achieved by day 10 in both arms. One hundred patients in the HD-DXM plus rhTPO arm and 96 patients in the HD-DXM monotherapy arm were included in the full analysis set. So, HD-DXM plus rhTPO resulted in a higher incidence of initial response (89.0% vs 66.7%, P < .001) and complete response (CR, 75.0% vs 42.7%, P < .001) compared with HD-DXM monotherapy. Response rate at 6 months was also higher in the HD-DXM plus rhTPO arm than that in the HD-DXM monotherapy arm (51.0% vs 36.5%, P = .02; sustained CR: 46.0% vs 32.3%, P = .043). Throughout the follow-up period, the overall duration of response was greater in the HD-DXM plus rhTPO arm compared to the HD-DXM monotherapy arm (P = .04), as estimated by the Kaplan-Meier analysis. The study drugs were generally well tolerated. In conclusion, the combination of HD-DXM with rhTPO significantly improved the initial response and yielded favorable SR in newly diagnosed ITP patients, thus could be further validated as a frontline treatment for ITP. This study is registered as clinicaltrials.gov identifier: NCT01734044.


Assuntos
Dexametasona/administração & dosagem , Púrpura Trombocitopênica Idiopática , Trombopoetina/administração & dosagem , Adulto , Idoso , Dexametasona/efeitos adversos , Intervalo Livre de Doença , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/mortalidade , Taxa de Sobrevida , Trombopoetina/efeitos adversos
8.
Am J Hematol ; 94(12): 1374-1381, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31591739

RESUMO

We conducted a prospective, multicenter study to evaluate the efficacy and safety of low-dose decitabine in adult patients with refractory immune thrombocytopenia. Adult patients who did not respond to, did not tolerate, or were unwilling to undergo splenectomy, with either a baseline platelet count less than 30 × 109 /L or the presence of bleeding symptoms and further need of ITP-specific treatments, were enrolled. Patients received decitabine at 3.5 mg/m2 intravenously for three consecutive days per cycle, for three cycles with a four-week interval between cycles. All patients were assessed every week during the first 12 weeks and at four-week intervals thereafter. We screened 49 patients for eligibility. Four patients were excluded and 45 received decitabine. At the end of decitabine treatment, complete response was achieved in eight patients (17.78%), and partial response was achieved in 15 patients (33.33%). The median time to initial response was 28 days (range, 14-70 days). Furthermore, seven relapsed patients received decitabine retreatment and all showed platelet response, including one complete response and six partial responses. Sustained response rates at 6, 12 and 18 months were 44.44% (20/45), 31.11% (14/45) and 20.0% (9/45), respectively. For responders, immune thrombocytopenia-related symptoms, fatigue, psychological health, fear, and overall quality of life were significantly improved. Adverse events were observed in 13 (28.89%) patients. No serious adverse events were recorded. In conclusion, low dose decitabine is potentially effective and safe in the management of adults with refractory immune thrombocytopenia. This trial is registered with clinicaltrials.gov identifier: NCT01568333.


Assuntos
Decitabina/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Adulto , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Terapia Combinada , Decitabina/administração & dosagem , Decitabina/efeitos adversos , Esquema de Medicação , Resistência a Medicamentos , Substituição de Medicamentos , Feminino , Gastroenteropatias/induzido quimicamente , Hemorragia/etiologia , Hemorragia/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Contagem de Plaquetas , Estudos Prospectivos , Púrpura Trombocitopênica Idiopática/complicações , Púrpura Trombocitopênica Idiopática/cirurgia , Qualidade de Vida , Recidiva , Esplenectomia
9.
Mol Immunol ; 101: 377-385, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30055408

RESUMO

Endoplasmic reticulum (ER) stress is induced in chronic myelogenous leukemia (CML) cells. As an important sensor of ER stress, inositol-requiring protein-1α (IRE1α) promotes the survival of acute myeloid leukemia. NLRP1 inflammasome activation promotes metastatic melanoma growth and that IRE1α can increase NLRP1 inflammasome gene expression. This study aimed to investigate the role and molecular mechanism of IRE1α in CML cell growth. We found that overexpression of IRE1α or NLRP1 significantly promoted the proliferation and decreased the apoptosis of CML cells, whereas downregulation of these two genes showed the opposite effects. 4-phenylbutyric acid (4-PBA), an ER stress inhibitor, reduced the expression of IRE1α and NLRP1. IRE1α elevated NLRP1 expression via cAMP responsive element binding protein (CREB) phosphorylation. NLRP1 inflammasome was activated in CML cells and its activation partly reversed ER stress inhibitor-induced cell apoptosis. Furthermore, inhibition of IRE1α/NLRP1 pathway sensitized CML cells to imatinib-mediated apoptosis. Additionally, IRE1α expression was elevated and NLRP1 inflammasome was activated in primary cells from CML patients. Downregulation of IRE1α or NLRP1 suppressed the proliferation and elevated the apoptosis of primary CML cells. Collectively, this study demonstrated that the IRE1α/CREB/NLRP1 pathway contributes to the progression of CML and the development of imatinib resistance. Hence, targeting ER stress-related IRE1α expression or NLRP1 inflammasome activation may block CML development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Estresse do Retículo Endoplasmático , Endorribonucleases/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Mesilato de Imatinib/farmacologia , Inflamassomos/metabolismo , Proteínas NLR , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
10.
Zhonghua Xue Ye Xue Za Zhi ; 35(5): 388-92, 2014 May.
Artigo em Chinês | MEDLINE | ID: mdl-24857206

RESUMO

OBJECTIVE: To compare the efficacy and toxicity of the chemotherapeutic regimen containing pirarubicin and mitoxantrone on the treatment of relapsed or refractory acute myeloid leukemia (AML) in adults. METHODS: In this open prospective multicentre study, we randomly assigned patients with relapsed or refractory AML to receive TAE regimen (pirarubicin+cytarabine+etoposide) versus MAE regimen (mitoxantrone + cytarabine + etoposide). The efficacy and toxicity were compared between the two groups. RESULTS: 56 patients entered this clinical trial. The complete remission (CR) rate on TAE arm was 79.0% versus 55.6% on MAE arm with the overall response (OR) rates of 86.8% versus 88.9%, respectively. The CR was higher on TAE arm (P=0.035) but with no significant difference between the two groups regarding the overall response (OR) rate. The regimens were well tolerated in both groups. Hematologic and non-hematologic toxicity were similar except relatively lower the mean dosage of G-CSF, red blood cells and platelets transfusion on TAE arm. No significant differences were seen between the two groups regarding the overall survival and relapse free survival rates. CONCLUSION: TAE regimen might be an effective salvage therapy in patients with relapsed or refractory AML.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doxorrubicina/análogos & derivados , Leucemia Mieloide Aguda/tratamento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Dactinomicina/administração & dosagem , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Metotrexato/administração & dosagem , Estudos Prospectivos , Recidiva , Indução de Remissão
11.
Virus Res ; 179: 235-40, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24239755

RESUMO

Profiling and assembly of virus-derived small interfering RNAs (siRNAs) using next-generation sequencing technologies have been very useful for identification and diagnosis of a number of plant and invertebrate viruses. In this work, we have conducted high-throughput pyrosequencing and bioinformatic analysis of the small brown planthopper (SBPH, Laodelphax striatellus), and these analyses unexpectedly showed that the Himetobi P virus (HiPV) was present in our laboratory cultures. HiPV was also found to infect our brown planthopper (BPH, Nilaparvata lugens) and the white-backed planthopper (WBPH, Sogatella furcifera) cultures. The majority of the HiPV-derived siRNAs (Hd-siRNAs) were 21 and 22 nucleotides in length and nearly two-thirds of the siRNAs originated from the HiPV genomic RNA strand. The Hd-siRNAs were evenly distributed across the genome and this indicates that the HiPV genome contributes uniformly to production of Hd-siRNAs. Although HiPV infection appeared to be innocuous to the SBPH, alterations of gene expressions involved in reproduction, cytoskeleton structure and defense responses such as RNA interference pathways (RNAi) genes were observed. Furthermore, we demonstrated that silencing Agronaute 2 in L. striatellus enhanced HiPV accumulation, and this observation provides evidence for the existence of RNAi defenses against HiPV in the SBPH.


Assuntos
Dicistroviridae/genética , Hemípteros/virologia , Interferência de RNA , RNA Interferente Pequeno/genética , Animais , Dicistroviridae/classificação , Dicistroviridae/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Dados de Sequência Molecular , RNA Interferente Pequeno/metabolismo
12.
Biochem Biophys Res Commun ; 345(3): 976-83, 2006 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-16712794

RESUMO

Obesity is highly correlated with systemic insulin resistance. To assess the effect of fat cell on the development of hepatic insulin resistance, an in vitro system was developed in which primary hepatocytes were kept in co-culture with 3T3-L1 cells, then insulin signaling and glycogen production were subsequently analyzed in hepatocytes. The results showed that insulin-induced tyrosine phosphorylation of insulin receptor substrate (IRS)-2 was significantly blocked. Insulin-regulated activation of Akt kinase and glucose production in the hepatocytes were also reduced after co-culture. On the other hand, addition of TNF-alpha or IL-6 neutralizing antibodies to the supernatant of co-culture recovered both IRS-2 phosphorylation and Akt activation. In conclusion, fat cells may induce insulin resistance in liver cells, and this process appears to be mediated by TNF-alpha and IL-6. Our data present first the direct evidence of interaction for insulin signaling event between the adipocytes and hepatocytes.


Assuntos
Adipócitos/citologia , Técnicas de Cocultura , Hepatócitos/citologia , Resistência à Insulina , Células 3T3-L1 , Transporte Ativo do Núcleo Celular , Animais , Proteínas Substratos do Receptor de Insulina , Interleucina-6/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
13.
Yi Chuan ; 26(2): 274-82, 2004 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-15640002

RESUMO

Mitochondrial DNA (mtDNA) encodes subunits of the mitochondrial electron transport system and the rRNAs and tRNAs required for constructing the mitochondrial translational machinery. Each subunit encoded by mtDNA is essential for normal oxidative phosphorylation. Thus, integrity of the mtDNA is crucial for the survival of organisms. It has long been held that there is no DNA repair in mitochondria. But in recent years,a number of repair factors have been found in mitochondrial extracts, suggesting the presence of DNA repair in mitochondria. This review summarized recent progress of enzyme in mitochondrial DNA repair processes.


Assuntos
DNA Glicosilases/metabolismo , Reparo do DNA/fisiologia , DNA Mitocondrial/metabolismo , Mitocôndrias/genética , Animais , DNA Helicases/metabolismo , DNA Ligases/metabolismo , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Humanos , Mitocôndrias/enzimologia
14.
IUBMB Life ; 55(3): 133-7, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12822889

RESUMO

A new PCR based method was developed to detect deleted mitochondrial DNA (mtDNA). Peripheral blood cell DNA was obtained from a victim who was accidently exposed to a 60Co radiation source in 1990. Using the DNA as template, first PCR was performed to generate multiple products including true deletions and artifacts. The full length product was recovered and used as template of secondary PCR. The suspicious deletion product of mtDNA could be confirmed only if it was yielded by first PCR. Using either original primers or their nested primers, the suspicious deletion product was amplified and authenticated as a true deletion product. The template was recovered and determined to be a deletion by sequencing directly. The results show that a new mtDNA deletion, which spans 889 bp from nt 11688 to nt 12576, was detected in the peripheral blood cells of the victim. It indicates that this new PCR-based method was more efficient at detecting small populations of mtDNA deletion than other routine methods. MtDNA deletion was found in the victim, suggesting the relationship between the deletion and phenotypes of the disease.


Assuntos
Radioisótopos de Cobalto/efeitos adversos , DNA Mitocondrial/genética , DNA Mitocondrial/efeitos da radiação , Reação em Cadeia da Polimerase/métodos , Deleção de Sequência , Adulto , Sequência de Bases , DNA/sangue , Humanos , Masculino , Mutação , Liberação Nociva de Radioativos
15.
IUBMB Life ; 55(3): 139-44, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12822890

RESUMO

The pathogenetic mechanism of the most extensively investigated A3243G mutated tRNALeu(UUR) gene, which causes the MELAS encephalomyopathy, maternally inherited diabetes, or chronic progressive external ophlthalmoplegia, is still unresolved, despite the numerous investigations on the topic. Previous evidences presented in published work suggested that the mitochondrial DNA harboring A3243G mutation result decreases in the rates of mitochondrial protein synthesis. To search for differences in aminoacylation of mitochondrial DNA-encoded wild-type and mutant human tRNALeu(UUR), we have expressed and purified the two kinds of tRNAsLeu(UUR), and have expressed human mitochondrial leucyl-tRNA synthetase for in vitro assays of aminoacylation of wild-type and mutant human tRNALeu(UUR). The results indicate human mitochondrial tRNALeu(UUR) gene A3243G point mutant can remarkably reduce its aminoacylation, suggesting it could be one of the mechanisms that the mutation can produce in such clinical phenotypes.


Assuntos
DNA Mitocondrial/genética , RNA de Transferência de Leucina/metabolismo , Acilação , Humanos , Cinética , Mutação Puntual , RNA de Transferência de Leucina/genética , Transcrição Gênica
16.
Yi Chuan ; 25(4): 383-7, 2003 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-15639892

RESUMO

The wild-type and mutant-type human mitochondrial tRNALeu(UUR) genes were synthesized and transcribed in vitro with T7 RNA polymerase. The kinetic parameters of human mitochondrial leucyl-tRNA synthetase(mtLeuRS) were determined with wild-type and mutant-type human mitochondrial tRNALeu(UUR) respectively. The results show that the value of Km/Kcat of mtLeuRS for the mutant-type tRNALeu(UUR) is 63.9% as compared with the wild-type. Human mitochondrial tRNALeu(UUR) gene A3243G point mutant can remarkably reduce it's aminoacylation activity, suggesting it would be one of the mechanisms that the mutation could produce such clinical phenotypes.

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