Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Rev Sci Instrum ; 95(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38758767

RESUMO

As the plasma beta (ß) increases in high-performance tokamaks, electromagnetic turbulence becomes more significant, potentially constraining their operational range. To investigate this turbulence, a cross-polarization scattering (CPS) diagnostic system is being developed on the HL-3 tokamak for simultaneous measurements of density and magnetic fluctuations. In this work, a quasi-optical system has been designed and analyzed for the Q-band CPS diagnostic. The system includes a lens group for beam waist size optimization, a rotatable wire-grid polarizer for polarization adjustment, and a reflector group for measurement range regulation and system response enhancement. Laboratory tests demonstrated a beam radius of order 4 cm at the target measurement location (near the plasma pedestal), cross-polarization isolation exceeding 30 dB, and poloidal and toroidal angle adjustment ranges of ±40° and ±15°, respectively. These results verify the system's feasibility through laboratory evaluations. The quasi-optical system has been installed on the HL-3 tokamak during the 2023 experimental campaign to support the development of CPS diagnostics.

2.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37862534

RESUMO

Plasma Position Reflectometry (PPR) is planned to provide plasma position and shape information for plasma operation in future fusion reactors. Its primary function is to calibrate the drift of the magnetic signals due to the integral nature of magnetic measurement. Here, we attempt to measure plasma position using ordinary mode (O-mode) and extraordinary mode (X-mode) reflectometry systems on two tokamaks. A new physical model based on the phase shift is proposed to deduce the relative movement of the cut-off layer without density inversion. We demonstrate the plasma position measurements by absolute measurement from density profile inversion and relative measurement from phase shift. The combination of X-mode and O-mode reflectometers can minimize the limitations of single polarization reflectometry and further increase the accuracy of plasma position measurement. These results could provide an important technical basis for the further development of a real-time control system based on PPR.

3.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37668510

RESUMO

A 105 GHz collective Thomson scattering (CTS) diagnostic has been successfully developed for fast-ion measurements on the HL-2A tokamak, and it has been deployed during an experimental campaign. Enhanced signals exhibiting synchronous modulation characteristics have been observed across all CTS channels upon the launch of a modulated probe wave. Results show that the intensity of the CTS signal increases with Neutral Beam Injection (NBI) power and is proportional to neutron count, indicating that the scattering signal contains a contribution from fast ions. Compared with the signal without NBI, the enhanced scattering spectrum due to NBI is slightly wider than the predicted fast ion range. Such broadening might be attributed to the heating effects of the gyrotron.

4.
Zhonghua Nei Ke Za Zhi ; 62(4): 384-392, 2023 Apr 01.
Artigo em Chinês | MEDLINE | ID: mdl-37032133

RESUMO

Objective: To investigate the quality of life and associated factors in patients with coronary heart disease (CHD) in China. Methods: A cross-sectional study of 25 provinces and cities in China was performed from June to September 2020. A questionnaire was used to collect the socio-demographic and clinical information of patients with CHD, while the European Five-dimensional Quality of Life Scale (EQ-5D) was used to assess the quality of life. Multiple linear regression model was performed to analyze the associated factors. Results: The median age of the 1 075 responders was 60 (52, 67) years, and 797 (74.1%) were men. The EQ-5D and EQ-VAS indices were 0.7 (0.5, 0.8) and 60.0 (40.0, 80.0). Among the five dimensions in the quality of life scale, the frequency of anxiety/depression was the highest (59.8%), while problems in self-care was the lowest (35.8%). In the multiple linear regression model, female, increasing age, obesity, comorbidity(ies), anxiety/depression, social media channels, and receiving the CABG therapy were associated with the lower EQ-5D index (all P<0.05). In addition, increasing age, obesity, comorbidity (ies), depression, anxiety and depression, social media channels, and receiving the CABG therapy were associated with lower EQ-VAS index (all P<0.05). Conclusion: Over half of the patients with CHD in China have a low quality of life, which is related to gender, age, obesity, treatment pathway, the presence or absence of comorbidity (ies), and psychological state. In addition to managing the adverse effects of traditional socio-demographic factors on the quality of life, clinical practices should pay attention to the psychological state of patients. Moreover, establishing a WeChat group for doctor-patient communication could improve the quality of life of CHD patients.


Assuntos
Doença das Coronárias , Qualidade de Vida , Masculino , Humanos , Feminino , Qualidade de Vida/psicologia , Autorrelato , Estudos Transversais , Inquéritos e Questionários , Obesidade
5.
Zhonghua Xin Xue Guan Bing Za Zhi ; 50(8): 785-790, 2022 Aug 24.
Artigo em Chinês | MEDLINE | ID: mdl-35982011

RESUMO

Objective: To investigate the correlation between heart rate index (HRI), systolic blood pressure(SBP) peak-to-SBPrest ratio (SBPR) and peak oxygen consumption (peakVO2) in patients with chronic heart failure (CHF), and discuss the possibility of using HRI and SBPR collected during exercise to assess the exercise tolerance of CHF patients in the absence of gas analysis. Methods: In this cross-sectional study, a total of 547 patients with CHF who underwent cardiopulmonary exercise test(CPET) in Tongji Hospital Heart Rehabilitation Center Affiliated to Tongji University from March 2007 to December 2018 were collected retrospectively, focusing on their clinical data including age, gender, type of heart failure,BMI as well as data collected during their CPETs, such as peakVO2, HRI and SBPR. Spearman univariate correlation analysis was used for statistical analysis, to unveil the correlations between peakVO2 and those parameters, and multiple linear regression analysis was also conducted. Results: A total of 547 CHF patients conducting CPET were included in this research, of which 447 were male, at age of 63(56, 69). Univariate analysis indicates that HRI, SBPR and peakVO2 showed significant positive correlation (r=0.323, 0.263, respectively, all P<0.001); Age and peak VO2 showed significant negative correlation(r=-0.207, P<0.001); Male patients showed peakVO2 higher than female(r=-0.229, P<0.001); PeakVO2 of heart failure with reduced ejection fraction(HFrEF) was lower than heart failure with mid-range ejection fraction(HFmrEF)and heart failure with preserved ejection fraction(HFpEF) (r=0.181, P<0.001). Body mass index (BMI) had no significant correlation with peakVO2 (P>0.05). Multivariate linear regression analysis showed that the HRI, SBPR were positively correlated with peakVO2(t=7.68, 5.08, respectively, all P<0.05), while age and BMI showed negative correlation with peakVO2(t=-5.43, -0.31, respectively, all P<0.05). PeakVO2 of male was higher than female(t=-6.03, P<0.05), and peakVO2 of HFrEF was lower than those of HFmrEF and HFpEF(t=3.17, 4.48, respectively, all P<0.05). A linear equation (F=33.52, adjusted R2=0.29) could be constructed: peakVO2=10.65(male) or 8.53(female)+4.26HRI+3.31SBPR-0.07age-0.13BMI+0(HFrEF) or 1.05 (HFmrEF) or 1.62(HFpEF). Conclusion: HRI and SBPR are positively correlated with peakVO2. In the absence of gas analysis, it is possible to apply HRI and SBPR during exercise to predict exercise tolerance in patients with CHF.


Assuntos
Insuficiência Cardíaca , Doença Crônica , Estudos Transversais , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Prognóstico , Estudos Retrospectivos , Volume Sistólico/fisiologia
6.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(9): 796-803, 2021 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-34530561

RESUMO

Objective: Contrast-enhanced CT is an important method of preoperative diagnosis and evaluation for the malignant potential of gastric submucosal tumor (SMT). It has a high diagnostic accuracy rate in differentiating gastric gastrointestinal stromal tumor (GIST) with a diameter greater than 5 cm from gastric benign SMT. This study aimed to use deep learning algorithms to establish a diagnosis model (GISTNet) based on contrast-enhanced CT and evaluate its diagnostic value in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before surgery. Methods: A diagnostic test study was carried out. Clinicopathological data of 181 patients undergoing resection with postoperative pathological diagnosis of gastric SMT with a diameter ≤ 5 cm at Department of Gastrointestinal Surgery of Renji Hospital from September 2016 to April 2021 were retrospectively collected. After excluding 13 patients without preoperative CT or with poor CT imaging quality, a total of 168 patients were enrolled in this study, of whom, 107 were GIST while 61 were benign SMT (non-GIST), including 27 leiomyomas, 24 schwannomas, 6 heterotopic pancreas and 4 lipomas. Inclusion criteria were as follows: (1) gastric SMT was diagnosed by contrast-enhanced CT before surgery; (2) preoperative gastroscopic examination and biopsy showed no abnormal cells; (3) complete clinical and pathological data. Exclusion criteria were as follows: (1) patients received anti-tumor therapy before surgery; (2) without preoperative CT or with poor CT imaging quality due to any reason; (3) except GIST, other gastric malignant tumors were pathologically diagnosed after surgery. Based on the hold-out method, 148 patients were randomly selected as the training set and 20 patients as the test set of the GISTNet diagnosis model. After the GISTNet model was established, 5 indicators were used for evaluation in the test set, including sensitivity, specificity, positive predictive value, negative predictive value and the area under the receiver operating curve (AUC). Then GISTNet diagnosis model was compared with the GIST-risk scoring model based on traditional CT features. Besides, in order to compare the accuracy of the GISTNet diagnosis model and the imaging doctors in the diagnosis of gastric SMT imaging, 3 radiologists with 3, 9 and 19 years of work experience, respectively, blinded to clinical and pathological information, tested and judged the samples. The accuracy rate between the three doctors and the GISTNet model was compared. Results: The GISTNet model yielded an AUC of 0.900 (95% CI: 0.827-0.973) in the test set. When the threshold value was 0.345, the sensitivity specificity, positive and negative predictive values of the GISTNet diagnosis model was 100%, 67%, 75% and 100%, respectively. The accuracy rate of the GISTNet diagnosis model was better than that of the GIST-risk model and the manual readings from two radiologists with 3 years and 9 years of work experience (83% vs. 75%, 60%, 65%), and was close to the manual reading of the radiologist with 19 years of work experience (83% vs. 80%). Conclusion: The deep learning algorithm based on contrast-enhanced CT has favorable and reliable diagnostic accuracy in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before operation.


Assuntos
Aprendizado Profundo , Tumores do Estroma Gastrointestinal , Neoplasias Gástricas , Diagnóstico Diferencial , Tumores do Estroma Gastrointestinal/diagnóstico por imagem , Humanos , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
7.
Zhonghua Yan Ke Za Zhi ; 56(8): 593-599, 2020 Aug 11.
Artigo em Chinês | MEDLINE | ID: mdl-32847334

RESUMO

Objective: To investigate the prevalence, causes and risk factors of moderate or severe visual impairment and blindness in people with type 2 diabetes over 50 years old in Funing County, Yancheng. Methods: This is a cross-sectional study. Using cluster random sampling, 84 survey sites were selected, and eye examination was performed on people with type 2 diabetes over 50 years old who were registered with the chronic disease information center of Funing County Center for Disease Control and Prevention in Yancheng, Jiangsu. The prevalence of moderate or severe visual impairment and blindness were calculated by different ages and genders. The causes of blindness and visual impairment were determined, and their influencing factors were analyzed by univariate and multivarite logistic regression. Results: A total of 2 067 people were investigated in this study, and 1 909 people were included. The response rate was 92.4%. Based on PVA, the prevalence of blindness and moderate to severe visual impairment was 5.29% (95%CI: 4.29%-6.30%) and 18.54% (95%CI: 16.80%-20.29%). The prevalence of blindness was related to age, marital status, education, duration of diabetes, history of diabetic nephropathy, systolic blood pressure and nuclear opacity. The prevalence of moderate or severe visual impairment was related to age, gender, educational level, diabetes treatment, exercise, and glycated hemoglobin. The prevalence of blindness and moderate to severe visual impairment was 3.67% (95%CI: 2.82%-4.51%) and 9.80% (95%CI: 8.46%-11.13%) based on BCVA. The prevalence of blindness was related to age, marital status, education, duration of diabetes, history of diabetic nephropathy, exercise and systolic blood pressure, while the prevalence of moderate or severe visual impairment was related to age, educational level, diabetes treatment and nuclear opacity. The primary cause of blindness and visual impairment is cataract, followed by diabetic retinopathy. Conclusions: The prevalence of moderate or severe visual impairment and blindness in people with type 2 diabetes in Funing County is relatively high. Attention should be paid to the prevention of blindness in this population. (Chin J Ophthalmol, 2020, 56: 593-599).


Assuntos
Catarata , Diabetes Mellitus Tipo 2/complicações , Baixa Visão/epidemiologia , Cegueira/etiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários , Transtornos da Visão/epidemiologia
9.
Zhonghua Gan Zang Bing Za Zhi ; 26(12): 940-944, 2018 Dec 20.
Artigo em Chinês | MEDLINE | ID: mdl-30669788

RESUMO

Objective: To study serum HCV antibody (anti-HCV) with geographic distribution characteristics in Zhejiang Province. Methods: A stratified random cluster sampling method was used. Serum samples of the surveyed population were collected from selected hospitals, anti-HCV antibodies were examined, then hepatitis C infection rates among different genders, regions and age groups were analyzed. The anti-HCV rate was compared using the χ (2) test. Results: The average anti-HCV positive rate in Zhejiang Province was 0.24% [95% confidence interval (CI): 0.16% ~ 0.32%]. The antibody positive rate in the plain area was 0.32% (95% CI: 0.19% ~ 0.45%), which was significantly higher than the coastal islands 0.05%(95% CI: 0.00% ~ 0.12%, χ (2) = 7.638, P < 0.05). There was no significant difference between plain area and hilly area 0.22% (95% CI: 0.03% - 0.41%). There was no statistically significant difference in anti-HCV positive rates between males and females (χ (2) = 2.238, P = 0.135). The highest positive rate of anti-HCV (0.93%) was in the population aged 56-60 years and the lowest in the population aged less than 20 years. Anti-HCV positive rate of all age groups in 2017 was lower than that of 2006 seroepidemiological study of hepatitis C. Conclusion: Zhejiang Province is a region with low anti-HCV positive rate and the disease prevalence further reduced than 10 years ago. The positive rate of anti-HCV in plain areas is higher than islands. Middle-aged and elderly people are the age group with high prevalence, and the anti-HCV positive rate in people under 20 years old is exceptionally low. Gender differences in anti-HCV positive rate have little effect.


Assuntos
Hepacivirus , Anticorpos Anti-Hepatite C/sangue , Hepatite C/epidemiologia , Adulto , Idoso , China/epidemiologia , Feminino , Hepatite C/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Adulto Jovem
10.
Genet Mol Res ; 14(4): 12537-46, 2015 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-26505404

RESUMO

To understand the effects of disease-resistant maize varieties and new cropping systems on the population of Curvularia lunata, 52 isolates of C. lunata were collected in China from 2011 to 2013. The isolates were analyzed in terms of phylogenetic relationships, morphology, and pathogenicity. Phylogenetic analysis showed that the 52 isolates clustered into 2 distinct clusters with further subdivisions, suggesting the emergence of new genetic divergence within C. lunata. Results of morphology and pathogenicity analyses demonstrated that there were significant differences among these isolates: 27 isolates were classified as fast growing, 5 as slow growing, and 20 as moderate growing. Three isolates had white-colored colonies, 13 had yellowish green-colored colonies, and the remaining isolates had dark green-colored colonies. Furthermore, conidiation rates were assessed: 30 isolates were characterized as having low conidiation rates, 15 as having medium conidiation rates, and the remaining 7 isolates as having high conidiation rates. Eleven of the isolates appeared to be strongly pathogenic against maize, 15 isolates proved to be weakly pathogenic against maize, and the remaining isolates were regarded to be moderately pathogenic. Interestingly, correlation analysis demonstrated a negative correlation between the growth rate and the pathogenicity of the isolates, while a positive correlation was observed between the conidiation rate and the pathogenicity. No correlation was observed between the colony color and the pathogenicity of the isolates.


Assuntos
Ascomicetos/genética , Ascomicetos/patogenicidade , Doenças das Plantas/microbiologia , Zea mays/microbiologia , China , Filogenia , Virulência
11.
Neuroscience ; 277: 356-66, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25014876

RESUMO

In a previous study, we have shown that the small organic compound tegaserod, a drug approved for clinical application in an unrelated condition, is a mimic of the regeneration-beneficial glycan polysialic acid (PSA) in a mouse model of femoral nerve injury. Several independent observations have shown positive effects of PSA and its mimetic peptides in different paradigms of injury of the central and peripheral mammalian nervous systems. Since small organic compounds generally have advantages over metabolically rapidly degraded glycans and the proteolytically vulnerable mimetic peptides, a screen for a small PSA mimetic compound was successfully carried out, and the identified molecule proved to be beneficial in neurite outgrowth in vitro, independent of its originally described function as a 5-HT4 receptor agonist. In the present study, a mouse spinal cord compression device was used to elicit severe compression injury. We show that tegaserod promotes hindlimb motor function at 6 weeks after spinal cord injury compared to the control group receiving vehicle only. Immunohistology of the spinal cord rostral and caudal to the lesion site showed increased numbers of neurons, and a reduced area and intensity of glial fibrillary acidic protein immunoreactivity. Quantification of regrowth/sprouting of axons immunoreactive for tyrosine hydroxylase and serotonin showed increased axonal density rostral and caudal to the injury site in the ventral horns of mice treated with tegaserod. The combined observations suggest that tegaserod has the potential for treatment of spinal cord injuries in higher vertebrates.


Assuntos
Indóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismos da Medula Espinal/tratamento farmacológico , Medula Espinal/efeitos dos fármacos , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Astrócitos/fisiologia , Axônios/efeitos dos fármacos , Axônios/patologia , Axônios/fisiologia , Contagem de Células , Sobrevivência Celular/efeitos dos fármacos , Cicatriz/tratamento farmacológico , Cicatriz/patologia , Cicatriz/fisiopatologia , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida , Gliose/tratamento farmacológico , Gliose/patologia , Gliose/fisiopatologia , Membro Posterior/fisiopatologia , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurônios/fisiologia , Recuperação de Função Fisiológica/fisiologia , Serotonina/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Tirosina 3-Mono-Oxigenase/metabolismo
12.
Genet Mol Res ; 12(4): 4162-70, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24114211

RESUMO

Exposure of humans to low levels of environmental oxygen results in alveolar hypoxia and normally causes chronic pulmonary hypertension and morphological alterations of precapillary pulmonary vessels. In this study, the microarray dataset GSE11341 was used to identify potential differentially expressed genes related with human lung microvascular endothelial cell hypoxia. In addition, gene ontology term enrichment analysis was performed to explore their underlying functions. In addition, we also investigated the small molecules by comparing with the Connectivity Map. We found that hypoxia samples of 3, 24, and 48 h relative to 0 h displayed 22, 21, and 29 differentially expressed genes, respectively. Among them, six genes (ADM, HMOX1, VEGFA, EGLN3, APOLD1, and ANGPTL4) were closely related to pulmonary microvascular endothelial cell hypoxia response. Three drugs (pindolol, sulfapyridine, and ciclopirox) were selected as candidates to treat hypoxia-related pulmonary diseases. In conclusion, our results provide some underlying drug targets for treatment of hypoxic pulmonary patients.


Assuntos
Células Endoteliais/metabolismo , Pneumopatias/metabolismo , Transcriptoma , Hipóxia Celular , Células Cultivadas , Endotélio Vascular/patologia , Perfilação da Expressão Gênica , Ontologia Genética , Humanos , Pulmão/irrigação sanguínea , Microvasos/patologia , Análise de Sequência com Séries de Oligonucleotídeos
13.
J Nanosci Nanotechnol ; 10(12): 8322-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21121334

RESUMO

Based on a facile vapor-phase transport method without any catalyst and template, one-dimensional single-crystalline bismuth oxide (Bi2O3) micro/nanoribbons were fabricated on silicon substrates in large quantities and morphology-controlled fabrication of Bi2O3 was achieved from a single precursor. The widths of Bi2O3 ribbons varied from 0.2 to 20 microm depending on the deposition temperatures. The thickness was in the range of 0.1-2 microm and the length reached several hundred micrometers and even millimeter range. The detailed composition and structural analysis confirmed the single-crystalline nature of alpha-Bi2O3 micro/nanoribbons with monoclinic structure. The photoluminescence spectrum of a single Bi2O3 ribbon showed a broadband emission from 450 to 750 nm in the visible region, consisting two peaks located at 589 and 697 nm which were primarily originated from the impurity ions and crystal defects. A self-catalyzed vapor-solid model was proposed to account for the growth mechanism of Bi2O3 ribbons with different morphologies.

14.
Tissue Antigens ; 70(4): 272-82, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17767548

RESUMO

Many malignant cancer cells downregulate human leukocyte antigen (HLA) class I antigen expression to evade T cell recognition. However, hepatocellular carcinoma (HCC) is exceptional to the general findings in cancer cells, and the mechanisms for its upregulation remain unclear. It has been reported that promyelocytic leukemia (PML) proto-oncogene controls the transcription of multiple class I antigen presentation genes in murine cancer cells. To find out the functional role of PML gene on the increased HLA class I antigen expression in HCC cells, we analyzed the expression of proto-oncogene PML and multiple class I antigen presentation genes in HCC specimens obtained in China. The results showed concordant changes of proto-oncogene PML and cell surface HLA-A expression in 44 paraffin-embedded HCC tissues. Furthermore, co-upregulated expression of PML genes and class I antigen presentation genes could be detected in 9 of 15 fresh HCC tissues by reverse transcription polymerase chain reaction (RT-PCR). In addition, studies using HCC cell lines showed that increased expression of HLA class I molecules paralleled with PML upregulation were detected in QGY-7701 HCC cell line with RT-PCR, western blot, and flow cytometry, and that the overexpression of exogenous PML in a low-expression class I cell line BEL-7405 could induce the expression of multiple class I antigen-presenting molecule genes and slightly but significantly increase the expression of cell surface HLA class I molecules. In conclusion, the expression of proto-oncogene PML and HLA class I molecules were concordantly upregulated and the expression of PML gene might be one of the mechanisms that leads to the increased expression of class I antigen in HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Proto-Oncogenes , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/imunologia , Linhagem Celular Tumoral , China , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/isolamento & purificação , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/imunologia , Proteína da Leucemia Promielocítica , Proto-Oncogene Mas , Regulação para Cima
15.
J Exp Clin Cancer Res ; 25(1): 115-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16761627

RESUMO

Human major histocompatibility complex (HLA), located on 6p21.3, encodes for genes involved in antigen processing and presentation. Loss of heterozygosity (LOH) at 6p21.3 may cause downregulated expression of HLA, thus provide tumor cells with an immune-escape tumor phenotype. In the present study, we detected HLA class I expression in gastric cancer and correlated it with LOH at 6p21.3. The expression of HLA class I antigen was analyzed by immunohistochemical procedure in 50 fresh surgically removed gastric cancers and corresponding normal tissues using 5 monoclonal antibodies (mAbs). LOH studies were detected by using 6 microsatellite markers located at 6p21.3, 1 marker located at 6q21 and 2 microsatellite markers flanking the beta2m gene. HLA class I complex was obviously downregulated in gastric cancer compared with corresponding normal tissues (t=4.00, p<0.01). The expression of beta2m gene was also downregulated in tumor, but not concordant with HLA class I surface downregulation. Out of the 50 tumors, 25 (50%) showed LOH of at least one STR marker at 6p21.3 while only 11 (22%) showed LOH of the two markers flanking the beta2m gene. The LOH frequency of D6S105, which is close to HLA-A gene, was the highest in all STR markers studied (34%). Downregulation of HLA class I expression was correlated with loss of chromosomal regions at 6p21.3 (chi-squared = 5.13, p<0.05). Our results suggested that LOH of 6p21.3 contributed to HLA class I downregulated expression in gastric cancer especially at HLA-A locus. LOH of HLA-A gene might be one of the mechanisms underlying the abnormal expression of HLA class I complex.


Assuntos
Cromossomos Humanos Par 6 , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Perda de Heterozigosidade , Neoplasias Gástricas/genética , Deleção Cromossômica , Marcadores Genéticos , Humanos , Imuno-Histoquímica
16.
Neuroscience ; 116(3): 639-47, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12573707

RESUMO

The two sides of the brain are differently involved in the modulation of immune responses as demonstrated by lesion and behavioral approaches. To study the interactions between cerebral cortex cytokines and brain lateralization, three groups of BALB/c mice were selected on the basis of their performance in the paw preference test (left-pawed, ambidextrous and right-pawed) and the levels of interleukin-1beta and interleukin-6 were measured in the two cerebral cortices after an intraperitoneal saline or lipopolysaccharide. Generally, right cortices had higher interleukin-1beta and interleukin-6 levels than left cortices for both saline and lipopolysaccharide-treated mice. A strong correlation between the levels of interleukin-1beta and interleukin-6 in right and left cortices and behavioral lateralization was observed. For the saline-treated mice: in their left cortices, interleukin-1beta levels were higher for ambidextrous mice than for right-pawed mice (P<0.05); in their right cortices, interleukin-6 levels were higher for ambidextrous mice than for right-/left-pawed mice, and right-pawed mice have higher levels of interleukin-6 than left-pawed mice (P<0.01). In their left cortices, interleukin-6 levels are higher for left-pawed mice than for both ambidextrous and right-pawed mice (P<0.01). In their left cortices, interleukin-6 levels are higher for left-pawed mice than for both ambidextrous and right-pawed mice (P<0.01). The quadratic curve equations showed that the levels of interleukin-1beta and interleukin-6 in the right/left cortices had a highly significant correlation with paw preference scores in both normal and lipopolysaccharide-treated mice. In conclusion, the present report demonstrated that the basal levels of interleukin-1beta and interleukin-6 were higher in the right cortex than left cortex in mice. There was a strong correlation between the levels of interleukin-1beta and interleukin-6 and behavioral lateralization, and cytokine asymmetries had a strong correlation with the direction and the intensity of behavioral lateralization.


Assuntos
Córtex Cerebral/metabolismo , Lateralidade Funcional/fisiologia , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Animais , Córtex Cerebral/imunologia , Extremidades/fisiologia , Feminino , Interleucina-1/imunologia , Interleucina-6/imunologia , Camundongos , Camundongos Endogâmicos BALB C
17.
Acta Crystallogr D Biol Crystallogr ; 57(Pt 8): 1196-200, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11517911

RESUMO

The crystal structure of human muscle creatine kinase has been determined by the molecular-replacement method and refined at 3.5A resolution. The structures of both the monomer and the dimer closely resemble those of the other known structures in the creatine kinase family. Two types of dimers, one with a non-crystallographic twofold symmetry axis and the other with a crystallographic twofold symmetry axis, were found to exist simultaneously in the crystal. These dimers form an infinite "double-helix"-like structure along an unusual long crystallographic 3(1) axis.


Assuntos
Creatina Quinase/química , Isoenzimas/química , Creatina Quinase Forma MM , Cristalização , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Conformação Proteica
18.
J Struct Biol ; 130(1): 1-9, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10806086

RESUMO

d-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) shows cooperative properties for binding coenzymes. The structure of apo-GAPDH from Palinurus versicolor has been solved at 2.0 A resolution by X-ray crystallography. The final model gives a crystallographic R factor of 0.178 in the resolution range 8 to 2 A. The structural comparison with holo-GAPDH from the same species reveals a conformational change induced by coenzyme binding similar to that observed in Bacillus stearothermophilus GAPDH but to a lesser extent. The differences in magnitude during the apo-holo transition between these two enzymes were analyzed with respect to the change of the amino acid composition in the coenzyme binding pocket. In the crystalline state of apo-GAPDH, the overall structures of the subunits are similar to each other; however, significant differences in temperature factors and minor differences in domain rotation upon coenzyme binding were observed for different subunits. These structural features are discussed in relation to the environmental asymmetry of crystallographically independent subunits.


Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/química , Nephropidae/enzimologia , Animais , Apoenzimas/química , Cristalografia por Raios X , Holoenzimas/química , Modelos Moleculares , Conformação Proteica , Estrutura Quaternária de Proteína , Eletricidade Estática
19.
Neurosci Lett ; 206(2-3): 204-6, 1996 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8710187

RESUMO

Superconducting Quantum Interference Devices (SQUIDs) can be used to detect neuromagnetic fields evoked in the peripheral and central nervous system. Up to now, such measurements had to be based on SQUIDs with a low critical temperature (Tc) requiring liquid helium cooling. Recent improvements in high-Tc SQUID technology relying on liquid nitrogen cooling led to a significant reduction in the system's noise level. Hare, first high-Tc recordings of weak neuromagnetic fields are demonstrated. In particular, along the entire somatosensory afferent pathway including peripheral nerves, brachial plexus and primary somatosensory neocortex evoked neuromagnetic activities were detected using conventional recording parameters for bandwidth and number of averages. This opens up a wide perspective for cost-effective high-Tc magnetometry in clinical neuroscience.


Assuntos
Plexo Braquial/fisiologia , Temperatura Baixa , Campos Eletromagnéticos , Nervos Periféricos/fisiologia , Córtex Somatossensorial/fisiologia , Potenciais Evocados/fisiologia , Humanos , Magnetismo , Nitrogênio , Teoria Quântica
20.
Biotechnol Bioeng ; 46(6): 510-3, 1995 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-18623345

RESUMO

The first large-scale production of 7-aminocephalosporanic acid (7ACA) from cephalosporin C (CPC) using a wholly enzymatic synthesis method is reported here. We produced 7ACA from CPC in as high a molar yield as 85% using the immobilized enzymes D-amino acid oxidase (D-AOD) and glutaryl-7-ACA acylase (GL-acylase). In the first reactor, CPC is converted to keto-adipyl-7-aminocephalosporanic acid (keto-7ACA) using an immobilized D-AOD isolated from a yeast, Trigonopsis variabilis. The keto-7ACA is then spontaneously converted to glutaryl-7-aminocephalosporanic acid (GL-7ACA) via a chemical reaction with hydrogen peroxide. The hydrogen peroxide is also a product of the D-AOD reaction. Near quantitative conversion of the keto-7ACA to GL-7ACA was observed. The second reactor converts GL-7ACA to 7ACA using an immobilized GL-acylase, which was isolated from a recombinant Escherichia coli. The final 7ACA crystalline product is a high quality product. The reactions are conducted under very mild aqueous conditions: pH 8.0 and 20 degrees to 25 degrees C. The production of desacetyl side products is minimal. This process is currently being implemented on an industrial scale to produce 7ACA.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...