Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
2.
Bull Exp Biol Med ; 173(3): 346-353, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35852692

RESUMO

We studied an amorphous solid dispersion of berberine with absorption enhancer sodium caprate (Huang-Gui solid dispersion preparations, HGSD). A therapeutic effect of HGSD was revealed in mice with type 2 diabetes mellitus and palmitate-induced injury to MIN6 ß-cells. HGSD treatment (150 mg/kg) improved glucose metabolism and decreased ß-cell apoptosis in diabetic mice. Furthermore, the effective component of HGSD berberine significantly attenuated the palmitate-induced decrease in MIN6 ß-cells viability and insulin secretion. Moreover, molecular docking analysis and Western blotting showed that berberine decreased cell apoptosis and expression of group VIA phospholipase A2 (iPLA2), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3. These data suggest that HGSD treatment protected ß-cells via inhibiting the iPLA2/p38 MAPK pathway.


Assuntos
Berberina , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Ilhotas Pancreáticas , Animais , Apoptose , Berberina/farmacologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Células Secretoras de Insulina/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Palmitatos/metabolismo , Palmitatos/farmacologia , Palmitatos/uso terapêutico , Fosfolipases/metabolismo , Fosfolipases/farmacologia , Fosfolipases/uso terapêutico , Fosfolipases A2 Independentes de Cálcio/metabolismo , Fosfolipases A2 Independentes de Cálcio/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
3.
Am J Physiol Renal Physiol ; 320(2): F193-F202, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33356952

RESUMO

Renal arteriolar tone depends considerably on the dilatory action of nitric oxide (NO) via activation of soluble guanylyl cyclase (sGC) and cGMP action. NO deficiency and hypoxia/reoxygenation are important pathophysiological factors in the development of acute kidney injury. It was hypothesized that the NO-sGC-cGMP system functions differently in renal afferent arterioles (AA) compared with efferent arterioles (EA) and that the sGC activator cinaciguat differentially dilates these arterioles. Experiments were performed in isolated, perfused mouse glomerular arterioles. Hypoxia (0.1% oxygen) was achieved by using a hypoxia chamber. Phosphodiesterase 5 (PDE5) and sGC subunits were considerably expressed on the mRNA level in AA. PDE5 inhibition with sildenafil, which blocks cGMP degradation, diminished the responses to ANG II bolus application in AA, but not significantly in EA. Vasodilation induced by sildenafil in ANG II-preconstricted vessels was stronger in EA than AA. Cinaciguat, an NO- and heme-independent sGC activator, dilated EA more strongly than AA after NG-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor) treatment and preconstriction with ANG II. Cinaciguat-induced dilatation of l-NAME-pretreated and ANG II-preconstricted arterioles was similar to controls without l-NAME treatment. Cinaciguat also induced dilatation in iodinated contrast medium treated AA. Furthermore, it dilated EA, but not AA, after hypoxia/reoxygenation. The results reveal an important role of the NO-sGC-cGMP system for renal dilatation and that EA have a more potent sGC activated dilatory system. Furthermore, AA seem to be more sensitive to hypoxia/reoxygenation than EA under these experimental conditions.


Assuntos
Angiotensina II/farmacologia , Arteríolas/enzimologia , Rim/irrigação sanguínea , Guanilil Ciclase Solúvel/metabolismo , Animais , Arteríolas/fisiologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico , Inibidores da Fosfodiesterase 5/farmacologia , Guanilil Ciclase Solúvel/genética
4.
Eur Rev Med Pharmacol Sci ; 24(24): 12929-12937, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33378043

RESUMO

OBJECTIVE: To investigate the target delivery properties of RC48-ADC, a novel antibody drug conjugate (ADC) comprising cytotoxic monomethyl auristatin E (MMAE) and an anti-human epidermal growth factor receptor 2 (HER2) antibody tethered via valine-citrulline linker, in vitro and in vivo. MATERIALS AND METHODS: Dissociation rate of MMAE from RC48-ADC was used as an estimate of its stability in serum. Cytotoxicity of the antibody and RC48-ADC towards multiple cell lines was measured. Subcellular distribution of the drug was determined by fluorescence imaging. The mechanism of lysosome targeting was verified. Endocytic pathways of RC48-ADC were assessed by the cellular fluorescence intensity of fluorescently-labelled drugs. Intracellular and extracellular distribution of MMAE was analysed after RC48-ADC or MMAE administration to characterize MMAE release. The serum and tumour concentration of MMAE was compared after tail-vein injection of RC48-ADC into tumour-bearing mice. RESULTS: RC48-ADC was highly stable in human serum. HER2-overexpressed cell line SK-BR-3 proliferation was stronger when suppressed by RC48-ADC than by the naked antibody. Both RC48-ADC and naked antibody were internalized via caveolae-mediated and clathrin-mediated endocytosis and concentrated in lysosomes. Higher HER2 expression was associated with enhanced uptake and intracellular release of conjugated MMAE; free MMAE could kill tumour cells via the bystander effect. Although serum RC48-ADC concentration was higher than that in tumours, exposure of MMAE in tumours was ~200 times higher than in serum, which rationalized the reduced toxicity of RC48-ADC. CONCLUSIONS: In vitro and in vivo experiments confirmed the targeted transport and release of RC48-ADC; it could selectively deliver MMAE to the targeted HER2-positive cell or tumour tissue, which could reduce off-target toxicity and enhance anti-tumour potency in humans.


Assuntos
Anticorpos Monoclonais/farmacologia , Citrulina/farmacologia , Sistemas de Liberação de Medicamentos , Imunoconjugados/farmacologia , Oligopeptídeos/farmacologia , Valina/farmacologia , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citrulina/sangue , Citrulina/química , Feminino , Imunoconjugados/sangue , Imunoconjugados/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Oligopeptídeos/sangue , Oligopeptídeos/química , Receptor ErbB-2/genética , Células Tumorais Cultivadas , Valina/sangue , Valina/química
5.
Zhonghua Xue Ye Xue Za Zhi ; 40(12): 1008-1014, 2019 Dec 14.
Artigo em Chinês | MEDLINE | ID: mdl-32023731

RESUMO

Objective: To investigate the clinical characteristics, diagnosis, treatment and prognosis of therapy-related myeloid neoplasms (t-MNs) after successful treatment for acute promyelocytic leukemia (APL) . Methods: Clinical data of 4 patients, diagnosed as t-MNs secondary to APL at Hematology Hospital of Chinese Academy of Medical Sciences from October 2012 to January 2019, were collected retrospectively. T-MNs related literature was reviewed. Results: The 4 cases were all females, with the median age 42 (range 40-53) years old at the diagnosis of APL. Regarding the induction and consolidation regimens, 3 patients received all-trans retinoid acid (ATRA) and arsenic trioxide (ATO) combined with anthracycline/anthraquinone and/or cytosine. One patient only received ATRA and other auxiliary drugs. Alkylating agents were not administrated. The 4 patients developed t-MNs 40 to 43 months after complete remission (CR) of APL, including 1 case of therapy-related myelodysplastic syndrome (t-MDS) and 3 cases of acute myeloid leukemia (t-AML) . The PML-RARα fusion genes were all negative when t-MNs developed. The three patients with t-AML were treated with 3 to 4 re-induction regimens, one of whom underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) after complete remission (CR) . One patient with t-MDS received hypomethylating agents. After a median follow-up of 54.5 (48-62) months, 2 patients with t-AML died, the median overall survival after t-MN was 12 (5-18) months. From 1989 to 2018, a total of 63 t-MN cases were reported in the literature. Therefore, 67 cases were analyzed when four patients in our center were added, including 27 males and 40 females with median age 52.5 (15-76) years. The median latency was 39 (12-126) months and the median overall survival after diagnosis of t-MN was 10 (1-39) months. Conclusions: Although rare, t-MNs may occur after successful control of APL. There are no existing guidelines for prevention and treatment of t-MNs, which have very poor prognosis. If cytopenia or other abnormalities of peripheral blood cells develop after 3 years of APL, t-MNs should be considered as a differential diagnosis.


Assuntos
Leucemia Mieloide Aguda , Leucemia Promielocítica Aguda , Segunda Neoplasia Primária , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica , Arsenicais , Feminino , Humanos , Leucemia Promielocítica Aguda/terapia , Pessoa de Meia-Idade , Óxidos , Estudos Retrospectivos , Resultado do Tratamento , Tretinoína
6.
Zhonghua Xue Ye Xue Za Zhi ; 39(8): 650-653, 2018 Aug 14.
Artigo em Chinês | MEDLINE | ID: mdl-30180466

RESUMO

Objective: To explore the efficacy and safety of chimeric antigen receptor T (CAR-T) cells in the treatment of central nervous system leukemia (CNSL). Methods: Two leukemia patients with CNSL were treated with CD19-CAR-T cells. The process and results of the entire treatment is reported and related literature review is conducted. Results: The patients were diagnosed as acute myeloid leukemia (AML)-M(2) with B lymphoid antigen expression and B cell acute lymphoblastic leukemia(B-ALL) by morphology and immunophenotype assay. The immunophenotype was consistent with the abnormal manifestations of AML-M(2) and B-ALL. Their clinical manifestations and laboratory tests met the diagnostic criteria of CNSL. The diagnosis was clear and the two patients were treated with CD19-CAR-T cell immunotherapy. Central nervous system symptoms were relieved. The imaging abnormalities of patient one has disappeared but cytokines release syndrome (CRS) occurred during the treatment. Cerebrospinal fluid of patient two was negative and no obvious CRS reaction was found. Conclusions: CAR-T cell immunotherapy is likely to induce the remission of CNSL and improve the prognosis.


Assuntos
Linfócitos T , Antígenos CD19 , Humanos , Imunoterapia Adotiva , Receptores de Antígenos de Linfócitos T , Receptores de Antígenos Quiméricos
7.
Zhonghua Xue Ye Xue Za Zhi ; 38(11): 956-961, 2017 Nov 14.
Artigo em Chinês | MEDLINE | ID: mdl-29224319

RESUMO

Objective: To investigate the feasibility of multiplex real-time RT-PCR with fluorescent probes in early screening of Ph-like acute lymphoblastic leukemia (ALL) and analyze the clinical feature and prognos. Method: A total of 118 adult B-ALL patients diagnosed between October 2010 and March 2016 were enrolled in this study. Multiplex RT-PCR was used to detect the Ph-like ALL related fusion gene and CRLF2 expression in 58 BCR-ABL and MLL rearrangement negative patients. The clinical features, treatment response and prognosis were analyzed in Ph-like fusion gene positive and/or CRLF2 over-expression patients. Result: Among 58 patients, 9 patients (9/58, 15.5%) showed Ph-like ALL related fusion genes positive and 10 patients (10/58, 17.2%) showed CRLF2 over-expression. There were statistical differences in age, WBC count, immunophenotypes, cytogenetics and risk stratification among Ph-like fusion gene positive or CRLF2 over-expression patients, Ph(+) patients, MLL(+) patients and B-other patients. The 2-year overall survival rates were 65%, 47%, 64% and 74% respectively among these four groups (P=0.043) . The 2-year relapse free survival rates were 51%, 39%, 62% and 70% respectively among these four groups (P=0.010) . Conclusion: Routine screening of Ph-like ALL by multiplex RTPCR is feasible.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Doença Aguda , Adulto , Proteínas de Fusão bcr-abl , Humanos , Reação em Cadeia da Polimerase Multiplex , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prognóstico
8.
Am J Physiol Renal Physiol ; 312(5): F908-F916, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28052871

RESUMO

Vasoconstriction plays an important role in the development of acute kidney injury in rhabdomyolysis. We hypothesized that myoglobin enhances the angiotensin II (ANG II) response in afferent arterioles by increasing superoxide and reducing nitric oxide (NO) bioavailability. Afferent arterioles of C57Bl6 mice were isolated perfused, and vasoreactivity was analyzed using video microscopy. NO bioavailability, superoxide concentration in the vessel wall, and changes in cytosolic calcium were measured using fluorescence techniques. Myoglobin treatment (10-5 M) did not change the basal arteriolar diameter during a 20-min period compared with control conditions. NG-nitro-l-arginine methyl ester (l-NAME, 10-4 M) and l-NAME + myoglobin reduced diameters to 94.7 and 97.9% of the initial diameter, respectively. Myoglobin or l-NAME enhanced the ANG II-induced constriction of arterioles compared with control (36.6 and 34.2%, respectively, vs. 65.9%). Norepinephrine responses were not influenced by myoglobin. Combined application of myoglobin and l-NAME further facilitated the ANG II response (7.0%). Myoglobin or l-NAME decreased the NO-related fluorescence in arterioles similarly. Myoglobin enhanced the superoxide-related fluorescence, and tempol prevented this enhancement. Tempol also partly prevented the myoglobin effect on the ANG II response. Myoglobin increased the fura 2 fluorescence ratio (cytosolic calcium) during ANG II application (10-12 to 10-6 M). The results suggest that the enhanced afferent arteriolar reactivity to ANG II is mainly due to a myoglobin-induced increase in superoxide and associated reduction in the NO bioavailability. Signaling pathways for the augmented ANG II response include enhanced cytosolic calcium transients. In conclusion, myoglobin may contribute to the afferent arteriolar vasoconstriction in this rhabdomyolysis model.


Assuntos
Angiotensina II/farmacologia , Arteríolas/efeitos dos fármacos , Rim/irrigação sanguínea , Mioglobina/farmacologia , Rabdomiólise/fisiopatologia , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Animais , Antioxidantes/farmacologia , Arteríolas/metabolismo , Arteríolas/fisiopatologia , Sinalização do Cálcio/efeitos dos fármacos , Óxidos N-Cíclicos/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Microscopia de Vídeo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Rabdomiólise/metabolismo , Marcadores de Spin , Superóxidos/metabolismo , Fatores de Tempo
9.
Zhonghua Yi Xue Za Zhi ; 96(15): 1164-7, 2016 Apr 19.
Artigo em Chinês | MEDLINE | ID: mdl-27117360

RESUMO

OBJECTIVE: To investigate the correlation between R2(*) value of enhanced T2 star-weighted angiography (ESWAN) sequence and primary hepatocellular carcinoma infiltration and tumor thrombus, and investigate the biological behavior of HCC. METHODS: A total of 221 cases of patients' imaging data with MRI examination(including ESWAN sequence) diagnosed as primary HCC were retrospectively analyzed.All the patients were collected from January 2014 to September 2015 in the First Affiliated Hospital of Dalian Medical University.The differences of R2(*) values in different MR types of HCC were analyzed.All patients were divided into infiltration group and non-infiltration group, tumor thrombus group and non-tumor thrombus group, the R2(*) values of the paired groups were compared.The diagnostic efficiency of R2(*) in HCC infiltration and tumor thrombus were evaluated by ROC curve, and to find out the threshold values. RESULTS: The MR types of 221 patients included 90 cases of nodular type, 62 cases of massive type, 69 cases of diffuse type.70 patients had tumor thrombus.The R2(*) values of different MR types were (21.82±8.52), (24.17±8.84)and (34.45±11.73) Hz, respectively.There was no statistically significant difference between the nodular and the massive types (P=0.144), while the difference between the nodular and diffuse type, the massive and diffuse types were statistically significant(P=0.000). The R2(*) values of infiltration group and non-infiltration group were (34.45±11.73) and (22.78±8.70) Hz , the R2(*) values of tumor thrombus group and non-tumor thrombus group were (31.20±12.17) and (24.21±9.90) Hz, the difference also had statistically significant(t=7.397 and 4.534, P=0.000 and 0.000). The AUC of R2(*) values for infiltration and tumor thrombus were 0.804, 0.681. R2(*) ≥24.68 Hz was the threshold value to diagnose the infiltration and tumor thrombus. CONCLUSION: R2(*) value can be used as a MR non-enhancement quantitative index to evaluate the biological behavior of HCC.


Assuntos
Angiografia/métodos , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Curva ROC , Estudos Retrospectivos
10.
Eur Rev Med Pharmacol Sci ; 18(9): 1373-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24867516

RESUMO

OBJECTIVES: The accurate identification of bronchioloalveolar carcinoma (BAC) from adenocarcinoma (AC) and other types of lung cancer is important from clinical perspectives; especially, when BAC is histologically-mixed with AC. We hypothesized that the elastic fibers (EF) pattern could be used as a differential marker to identify BAC from other lung cancers. The aim was to characterize the EF pattern in different types of lung cancer and evaluate its significance for differential diagnosis of BAC. PATIENTS AND METHODS: Clinical samples of different types of lung cancers were collected. The samples were stained by hematoxylin-eosin (H&E) staining for histopathological comparison. Then, modified Weigert's staining of the EF was performed to characterize its patterns. The EFs were semi-quantified and compared among different types of lung cancer. Further, transmission electronic microscopy (TEM) was performed and ultrastructural features of the EFs were compared between BAC and adenocarcinoma (AC). RESULTS: H&E staining histopathology could differentiate the most types of lung cancer except certain types, such as histologically-mixed BAC and AC. The EF pattern in BAC was uniquely different from other types of lung cancer as > 95% of BAC was + or ++ for EF staining while > 95% of other types of lung cancer were--or ± type. TEM study further confirmed the EF pattern difference between BAC and AC. CONCLUSIONS: As the data show, as > 95% BAC specimens can be identified from other lung cancers based on EF (Weigert's) staining. The EF pattern in BAC is uniquely different from other types of lung cancer and, therefore, can be used as a differential clinical marker of BAC.


Assuntos
Adenocarcinoma Bronquioloalveolar/ultraestrutura , Adenocarcinoma/ultraestrutura , Tecido Elástico/ultraestrutura , Neoplasias Pulmonares/ultraestrutura , Adenocarcinoma de Pulmão , Corantes , Diagnóstico Diferencial , Amarelo de Eosina-(YS) , Hematoxilina , Humanos , Microscopia Eletrônica de Transmissão , Valor Preditivo dos Testes , Coloração e Rotulagem
11.
Bull Environ Contam Toxicol ; 87(1): 58-64, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21516458

RESUMO

Organochlorine contaminants (OCs) in fish were determined to evaluate the potential risk to humans consuming fish originating in Baiyangdian Lake, North China. Relatively low levels of PCBs, HCHs and DDTs were observed, with mean concentrations ranging from 0.28 to 3.28 ng/g, wet weight. Among various fish species tested, the highest burden of OCs was recorded in northern snakehead (7.39 ng/g, wet weight) and the lowest was in grass carp (2.04 ng/g, wet weight). The hazard ratios (HRs), based on noncancer risk were all less than 1.0, while the HRs based on cancer risk exceeded 1.0 only for PCBs based on the 90th percentile concentration.


Assuntos
Contaminação de Alimentos/análise , Hidrocarbonetos Clorados/análise , Poluentes Químicos da Água/análise , Animais , China , DDT/análise , Monitoramento Ambiental/métodos , Peixes , Água Doce/análise , Água Doce/química , Humanos , Resíduos de Praguicidas/análise , Medição de Risco
12.
Oncogene ; 30(10): 1229-40, 2011 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-21076472

RESUMO

Yes-associated protein (YAP) is a downstream effector of the Hippo signaling pathway, which controls organ expansion and tissue development. We have recently defined the tumorigenic potential and clinical significance of the YAP1 oncogene in human hepatocellular carcinoma (HCC). The present study aims to define the tumorigenic properties of YAP in HCC and elucidate the related downstream signaling mechanism. In a gain-of-function study, we demonstrated that ectopic increased expression of YAP in the immortalized non-tumorigenic hepatocyte cell line MIHA confers tumorigenic and metastatic potentials, as evidenced by (1) enhanced aptitudes in cell viability, anchorage-independent growth, migration and invasion; (2) tumor formation in a xenograft mouse model; and (3) induction of HCC biomarker α-fetoprotein and activation of mitogen-activated protein kinase. Furthermore, we have identified AXL, a receptor tyrosine kinase, as a key downstream target that drives YAP-dependent oncogenic functions. RNAi-mediated knockdown of AXL expression decreased the ability of YAP-expressing MIHA cells and of the primary HCC cell line to proliferate and invade. These results indicate that AXL is a mediator of YAP-dependent oncogenic activities and implicates it as a potential therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Transformação Celular Neoplásica/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo , Animais , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular , Linhagem Celular , Movimento Celular/genética , Proliferação de Células , Transformação Celular Neoplásica/genética , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Humanos , Immunoblotting , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Nus , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno , Receptores Proteína Tirosina Quinases/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Transfecção , Transplante Heterólogo , Receptor Tirosina Quinase Axl
13.
SAR QSAR Environ Res ; 20(1-2): 91-101, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19343585

RESUMO

Using quantum chemical descriptors and partial least squares regression, a quantitative structure-activity relationship (QSAR) model is developed for the depuration rate constants (log k(d)) of 62 polychlorinated biphenyls (PCBs) in juvenile rainbow trout (Oncorhynchus mykiss). The values of the cross-validated regression coefficient (Qcum(2)) and standard deviation (SD) are 0.655 and 0.05, respectively. The high cross-validated coefficient and low standard deviation indicate that the QSAR model is well predictive. In the QSAR model, the following six descriptors are highly significant: QH(+) (the most positive charge of a hydrogen atom), HOF (standard heat of formation), CCR (core-core repulsion), EE (electronic energy), alpha(2) (squared average molecular polarisability), and S (molecular surface area). The significant descriptors show that the depuration of PCBs in rainbow trout may be mainly attributed to the biota-water partitioning process, and the reactive activity of PCB molecules may play a subordinate role.


Assuntos
Previsões/métodos , Oncorhynchus mykiss/metabolismo , Bifenilos Policlorados/metabolismo , Relação Quantitativa Estrutura-Atividade , Animais , Biotransformação , Modelos Estatísticos , Bifenilos Policlorados/química
14.
Zhongguo Yi Liao Qi Xie Za Zhi ; 25(1): 41-4, 2001 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-12583303

RESUMO

This paper introduces a kind of all-purpose medical electronic teaching instrument. According to the modularization design rule, a medical electronic teaching instrument integrated with information transfer, signal processing, keyboard monitoring and signal sampling, etc, can be realized. On the other hand, A/D, D/A, self-detecting of computer, collecting and testing of biological potentials, driving electromotor and generating functional signals, etc can also be realized by the related software based on the system. It has been proved that, by using single-chip processor and computer, the system can implement full-scale test and processing of biomedical signals so that operators can understand the principles and the construction of medical instruments more easily and deeply. Therefore, it is valuable in application of medical electronic coursesteaching, research and etc.


Assuntos
Instrução por Computador/instrumentação , Educação Médica , Tecnologia Educacional/instrumentação , Software , Desenho de Equipamento , Design de Software
15.
EMBO J ; 11(1): 145-55, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1740102

RESUMO

Antibody class switching is achieved by recombinations between switch (S) regions which consist of tandemly repeated sequences located 5' to Ig heavy chain constant (CH) region genes. RNA transcripts from specific unrearranged or germ-line Ig CH genes are induced in IgM+ B cells prior to their undergoing class switch recombination to the same CH genes. Thus, the antibody class switch appears to be directed by induction of accessibility, as assayed by transcription of germ line CH genes. For example, IL-4 induces transcripts from the mouse germ-line C gamma 1 and C epsilon genes to which it also directs switch recombination. We report here that the 150 bp region upstream of the first initiation site of RNA transcribed from the murine germ-line C gamma 1 gene, contains promoter and enhancer elements responsible for basal level transcription and inducibility by anti-Ig phorbol myristate acetate (PMA) and for synergy of these inducers with IL-4 in a surface IgM+ B cell line, L10A6.2 and a surface IgG2a+ B cell line, A20.3. Linker-scanning mutations demonstrated that multiple interdependent elements are required for inducibility by PMA and also for synergy with IL-4. Within the 150 bp region are several consensus sequences that bind known or putative transcription factors, including a C/EBP binding site--IL-4 responsive element, four CACCC boxes, a PU box, a TGF beta inhibitory element (TIE), an alpha beta-interferon response element (alpha beta-IRE) and an AP-3 site. The relationship between transcription regulated by these elements and the regulation of endogenous germ-line gamma 1 transcripts and switching to IgG1 is discussed.


Assuntos
Regulação da Expressão Gênica , Genes de Troca/genética , Cadeias gama de Imunoglobulina/genética , Sequências Reguladoras de Ácido Nucleico/genética , Animais , Anticorpos Anti-Idiotípicos , Sequência de Bases , Análise Mutacional de DNA , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Células Germinativas/efeitos dos fármacos , Imunoglobulina M/genética , Interleucina-4/farmacologia , Luciferases/genética , Camundongos , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão/genética , Acetato de Tetradecanoilforbol/farmacologia , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA