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1.
J Crit Care ; 52: 109-114, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31035185

RESUMO

PURPOSE: To validate the furosemide stress test (FST) for predicting the progression of acute kidney injury (AKI). MATERIALS AND METHODS: We performed a multicenter, prospective, observational study in patients with stage I or II AKI. The FST (1 mg/kg for loop diuretic naïve patients and 1.5 mg/kg in patients previously exposed to loop diuretics) was administered. Subsequent urinary flow rate (UFR) recorded and predictive ability of urinary output was measured by the area under the curve receiver operatic characteristics (AuROC). Primary outcome was progression to Stage III AKI. Secondary outcomes included in-hospital mortality and adverse events. RESULTS: We studied 92 critically ill patients. 23 patients progressed to stage III AKI and had significantly lower UFR (p < 0.0001). The UFR during the first 2 h was most predictive of progression to stage III AKI (AuROC = 0.87), with an ideal cut-off of less than 200mls, with a sensitivity of 73.9% and specificity of 90.0%. CONCLUSION: In ICU patients without severe CKD with mild AKI, a UFR of less than 200mls in the first 2 h after an FST is predictive of progression to stage III AKI. Future studies should focus on incorporating a FST as part of a clinical decision tool for further management of critically ill patients with AKI.


Assuntos
Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/mortalidade , Furosemida/farmacologia , Injúria Renal Aguda/urina , Idoso , Área Sob a Curva , Estado Terminal/mortalidade , Progressão da Doença , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Inibidores de Simportadores de Cloreto de Sódio e Potássio , Urodinâmica , Adulto Jovem
2.
Eur Rev Med Pharmacol Sci ; 22(23): 8248-8256, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30556864

RESUMO

OBJECTIVE: Circular RNAs (circRNAs) have recently shown capabilities as gene regulators in mammals. In this study, we aimed to evaluate the effects and mechanism of circ_0009910 in gastric cancer (GC). PATIENTS AND METHODS: Circ_0009910 expression was quantified by Real-time PCR in human GC cell lines and tissues. Association between circ_0009910 levels and clinicopathological factors and patient's prognosis was analyzed. The roles of circ_0009910 in regulating GC cell proliferation, colony formation, migration, and invasion were evaluated in vitro. Western blot analysis was conducted to detect the expressions of molecular markers of epithelial-mesenchymal transition (EMT). RESULTS: Circ_0009910 expression level was elevated in GC tissues and cell lines and associated with clinical stage (p = 0.032), distant metastasis (p = 0.028) and differentiation (p = 0.007). Kaplan-Meier survival analysis indicated that circ_0009910 expression in positive group has a worse overall survival compared to the negative group (p = 0.0013). Multivariate analysis showed that circ_0009910 was an independent risk factor for GC (HR = 2.346, 95% CI: 1.673-3.775, p = 0.006). Knockdown of circ_0009910 expression can suppress BGC823 and AGS cells proliferation, migration and invasion in vitro experiments. The results of Western blot indicated that knockdown of circ_0009910 increased expression of E-cadherin and decreased expression of the mesenchymal markers, snail and N-cadherin. CONCLUSIONS: Altogether, we demonstrate that circ_0009910 acts as a prognostic biomarker and promote cell proliferation, migration, invasion and EMT in GC, indicating that circ_0009910 may be a novel potential biomarker and therapeutic target of GC.


Assuntos
Movimento Celular , Proliferação de Células , RNA Circular/metabolismo , Neoplasias Gástricas/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Prognóstico , RNA Circular/genética , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-29687440

RESUMO

BACKGROUND: Hypophosphatemia has been associated with prolonged duration of respiratory failure and increased mortality in critically ill patients, but there is very limited evidence supporting the negative effects of low phosphate. We examined the association between hypophosphatemia at ICU admission and time to successful weaning and 28-day mortality. METHODS: This was a cohort study that included all mechanically ventilated adult patients admitted to the ICU in 2013 at Nordsjaellands Hospital. Hypophosphatemia was defined as a serum level below 0.80 mmol/L. Multivariate Cox-regression was used to evaluate the effect of hypophosphatemia on mechanical ventilation and 28-day mortality. Multiple imputation was used to adjust for missing values. RESULTS: A total of patients were admitted during the study period, of whom 190 were eligible. 122 (64.2%) had serum phosphate levels measured during the first 24 hours of admission, of whom 25 (20.5%) were found to be hypophosphatemic. About 74% of patients were successfully weaned from the ventilator within 28 days. Hypophosphatemia was not associated with this outcome (HR: 0.56; 95% CI: 0.30-1.04; P = .067). All-cause 28-day mortality was 32.6%. Hypophosphatemia was also not associated with 28-day mortality (HR: 1.64; 95% CI: 0.65-4.17; P = .447). Similar results were present in supplementary analysis where missing data were included by means of multiple imputation. CONCLUSION: Hypophosphatemia at ICU admission was not associated with prolonged respiratory failure nor mortality. Further studies are warranted, where phosphate is measured systematically on all patients to elucidate the effect of low phosphate on relevant outcomes.

4.
AJNR Am J Neuroradiol ; 38(1): 132-138, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27765737

RESUMO

BACKGROUND AND PURPOSE: Sinus stenosis occasionally occurs in dural arteriovenous fistulas. Sinus stenosis impedes venous outflow and aggravates intracranial hypertension by reversing cortical venous drainage. This study aimed to analyze the likelihood of sinus stenosis and its impact on cerebral hemodynamics of various types of dural arteriovenous fistulas. MATERIALS AND METHODS: Forty-three cases of dural arteriovenous fistula in the transverse-sigmoid sinus were reviewed and divided into 3 groups: Cognard type I, type IIa, and types with cortical venous drainage. Sinus stenosis and the double peak sign (occurrence of 2 peaks in the time-density curve of the ipsilateral drainage of the internal jugular vein) in dural arteriovenous fistula were evaluated. "TTP" was defined as the time at which a selected angiographic point reached maximum concentration. TTP of the vein of Labbé, TTP of the ipsilateral normal transverse sinus, trans-fistula time, and trans-stenotic time were compared across the 3 groups. RESULTS: Thirty-six percent of type I, 100% of type IIa, and 84% of types with cortical venous drainage had sinus stenosis. All sinus stenosis cases demonstrated loss of the double peak sign that occurs in dural arteriovenous fistula. Trans-fistula time (2.09 seconds) and trans-stenotic time (0.67 seconds) in types with cortical venous drainage were the most prolonged, followed by those in type IIa and type I. TTP of the vein of Labbé was significantly shorter in types with cortical venous drainage. Six patients with types with cortical venous drainage underwent venoplasty and stent placement, and 4 were downgraded to type IIa. CONCLUSIONS: Sinus stenosis indicated dysfunction of venous drainage and is more often encountered in dural arteriovenous fistula with more aggressive types. Venoplasty ameliorates cortical venous drainage in dural arteriovenous fistulas and serves as a bridge treatment to stereotactic radiosurgery in most cases.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/patologia , Malformações Vasculares do Sistema Nervoso Central/fisiopatologia , Hemodinâmica/fisiologia , Seios Transversos/patologia , Seios Transversos/fisiopatologia , Adulto , Malformações Vasculares do Sistema Nervoso Central/cirurgia , Angiografia Cerebral , Constrição Patológica/patologia , Constrição Patológica/fisiopatologia , Feminino , Humanos , Hipertensão Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Genet Mol Res ; 14(1): 1085-95, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25730048

RESUMO

The objectives of the present study were to identify additional genes that may play important roles in the regulation of skeletal muscle growth and development, and to provide fundamental information for understanding the underlying molecular mechanisms. Eighteen cDNA libraries were constructed from the longissimus muscle of Polled Dorset (PD) and Small-tailed Han (SH) fetuses. To reveal the differences between the two species, we analyzed the differences in gene expression in 60-, 90- and 120-day fetal skeletal muscle by applying Agilent ovine genome-wide microarray. In this study, we obtained 17,704 genes using a chip containing 39,242 probes. There were 88 differentially expressed genes in the 60-day group (P < 0.05), 128 genes in the 90-day group (P < 0.05), and 340 genes in the 120-day group (P < 0.05) between the two breeds. The differentially expressed genes were grouped in different GO categories and signaling pathways. These results suggested that there are many genetic differences in the muscle growth and development transcriptomes between these two breeds. This study laid the foundation for future genomic research in sheep.


Assuntos
Perfilação da Expressão Gênica , Desenvolvimento Muscular/genética , Músculo Esquelético/metabolismo , Transcriptoma/genética , Animais , Feto , Regulação da Expressão Gênica no Desenvolvimento , Músculo Esquelético/crescimento & desenvolvimento , Ovinos/genética , Carneiro Doméstico/genética
6.
Eur Rev Med Pharmacol Sci ; 18(2): 217-28, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24488911

RESUMO

OBJECTIVE: We aim to explore the expression difference between lung cancer cells and normal lung cells, and to investigate the mechanism of lung cancer development. Besides, we predicted the potential target site of transcriptional factors and microRNAs for differentially expressed genes (DEGs), which may help to regulate expression of DEGs. Small molecules were also identified to cure lung cancer. MATERIALS AND METHODS: Gene expression profiles we used were downloaded from Gene Expression Omnibus (GEO) using accession number of GSE2378. Firstly, we identified differential genes between lung cancer cells and normal lung cells by using R package limma. Then, we detected the processes and pathways that changed in lung cancer cells by Gene Ontology (GO) and KEGG pathway enrichment analysis. Potential target sites of transcriptional factors and microRNAs were also detected based on gene annotation data in MSigDB. Finally, small molecule drugs were screened via querying Connectivity Map database. RESULTS: We obtained 2961 differentially expressed genes between lung cancer cells and normal lung cells. Besides changes in cell cycle, metabolic processes and proteasome were also dramatically disordered. Some DEGs shared target sites of the transcription factor such as E2F, ETS and CEBPB. Target sites of hsa-miR-196a and hsa-miR-200c were also significantly enriched by DEGs. Iloprost simulated the state of normal cells, while MS-275 might be potential pathogenic substances. CONCLUSIONS: We investigate the lung cancer from Gene Ontology, pathway, transcription factors and microRNAs based on gene expression profiles. All these results may facilitate lung cancer treatment with a new breakthrough.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/genética , Transcriptoma/genética , Ciclo Celular/genética , Linhagem Celular , Linhagem Celular Tumoral , Perfilação da Expressão Gênica/métodos , Humanos , MicroRNAs/genética
7.
Am J Transplant ; 12(7): 1848-54, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22390401

RESUMO

Widespread thrombi are found among donor lungs rejected for transplantation. The 4G/5G polymorphism in the plasminogen activator inhibitor (PAI-1) gene impacts transcription and the 4G allele is associated with increased PAI-1 levels. We hypothesized that the 4G/4G genotype would be associated with decreased lung graft utilization, potentially because of worse oxygenation in the donor. We genotyped donors managed by the California Transplant Donor Network from 2001 to 2008 for the 4G/5G polymorphism in the PAI-1 gene. Non-Hispanic donors from 2001 to 2005 defined the discovery cohort (n = 519), whereas donors from 2006 to 2008 defined the validation cohort (n = 369). We found, that the odds of successful lung utilization among Non-Hispanic white donors were lower among donors with the 4G/4G genotype compared to those without this genotype in both the discovery (OR = 0.55, 95% CI = 0.3-0.9, p = 0.02) and validation (OR = 0.5, 95% CI = 0.3-0.9, p = 0.03) cohorts. This relationship was independent of age, gender, cause of death, drug use and history of smoking. Donors with the 4G/4G genotype also had a lower PaO2/FiO2 ratio (p = 0.03) and fewer donors with the 4G/4G genotype achieved the threshold PaO2/FiO2 ratio ≥ 300 (p = 0.05). These findings suggest a role for impaired fibrinolysis resulting in worse gas exchange and decreased donor utilization.


Assuntos
Transplante de Pulmão , Inibidor 1 de Ativador de Plasminogênio/genética , Polimorfismo Genético , Adulto , Estudos de Coortes , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Adulto Jovem
8.
Minerva Anestesiol ; 76(9): 725-36, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20820151

RESUMO

End-stage renal disease (ESRD) and chronic kidney disease (CKD) are increasing health problems worldwide. In the US alone, an estimated 26 million people suffer from some form of CKD. In countries such as India and Pakistan, the prevalence of CKD is also rapidly rising. The presence of CKD is associated with increased perioperative morbidity and mortality, even when adjusted for other variables such as hypertension or diabetes. Frequently, CKD is under diagnosed, so patients and physicians are often unaware of the impaired renal function. Renal dysfunction as a predictor of perioperative outcomes is discussed together with therapeutic interventions aimed at the protection of renal function. Better interventions and diagnostic tools, such as cystatin C, are needed to further improve perioperative morbidity and mortality in patients with CKD.


Assuntos
Falência Renal Crônica/complicações , Complicações Pós-Operatórias/etiologia , Glicemia , Doenças Cardiovasculares/complicações , Humanos , Falência Renal Crônica/sangue , Assistência Perioperatória
9.
Zhonghua Yi Xue Za Zhi (Taipei) ; 64(1): 23-30, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11310368

RESUMO

BACKGROUND: Surgery for deep nuclei arteriovenous malformations (AVMs) is controversial after the introduction of stereotactic irradiation and embolization. However, rupture of an AVM in this location can lead to catastrophic parenchymal or intraventricular hemorrhage. Thus, microsurgery still has its place in treatment of such lesions to prevent the untreated AVM bleeding or rebleeding. We present a series of 16 AVMs located in the deep nuclei treated by direct microsurgery before radiosurgery was available in 1993. METHODS: We reviewed the clinical and angiographic characteristic of 16 patients with deep-seated AVMs (three in caudate nucleus, three in lentiform nucleus and ten in thalamus). The surgical approach was described separately depending upon the location of the AVMs. The surgical outcomes were classified as excellent (symptoms improved), good (no additional neurological deficit), fair (minor neurological deficit), bad (major neurological deficit) and dead. RESULTS: Complete AVM elimination was achieved in 16 patients (100%) in one-stage operation. Eleven patients had excellent or good outcomes, three had fair outcomes and two had bad outcomes. There were no deaths in this series. Two patients had permanent hemiparesis to make a late morbidity rate of 12.5%. CONCLUSIONS: With improving microsurgical techniques, neuroimaging and neuroanesthesia, difficult and deeply hidden AVMs can be successfully resected under microsurgery with an acceptably low morbidity and mortality rate.


Assuntos
Gânglios da Base/cirurgia , Malformações Arteriovenosas Intracranianas/cirurgia , Tálamo/cirurgia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Microcirurgia , Radiocirurgia
10.
World J Gastroenterol ; 7(5): 597-601, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11819839

RESUMO

Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.


Assuntos
Carcinoma Hepatocelular/secundário , Neoplasias Hepáticas Experimentais/secundário , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Nus , Células Tumorais Cultivadas
11.
World J Gastroenterol ; 7(6): 816-20, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11854908

RESUMO

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in metastasis of hepatocellular carcinoma (HCC). METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve. RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P < 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P < 0.05). CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.


Assuntos
Comunicação Autócrina/fisiologia , Carcinoma Hepatocelular/secundário , Fator de Crescimento de Hepatócito/fisiologia , Neoplasias Hepáticas/patologia , Comunicação Parácrina/fisiologia , Proteínas Proto-Oncogênicas c-met/fisiologia , Humanos , Células Tumorais Cultivadas
12.
Hepatogastroenterology ; 47(32): 365-70, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10791191

RESUMO

BACKGROUND/AIMS: To investigate the effect of antisense H-ras DNA on tumorigenesity, apoptosis and metastasis of a high metastatic tumor model of human hepatocellular carcinoma in nude mice LCI-D20. METHODOLOGY: LCI-D20 cells in primary culture were treated with 10 microns/L antisense oligodeoxynucleotide (ODN) drugs in vitro. 1.5 x 10(6) LCI-D20 cells with or without pretreatment were inoculated into each elevated subcutaneous (s.c.) flap in 14 nude mice, 6 animals for antisense H-ras oligodeoxynucleotide treated cells, 4 for H-ras non-specific antisense oligodeoxynucleotide treated cells, and the rest 4 for cells without pretreatment. RESULTS: In in vitro cell culture study, 5-day continuous suppression of H-ras expression by antisense H-ras oligodeoxynucleotide resulted in significant inhibition of the proliferation of LCI-D20 cells (t = 31.529, P < 0.01). In situ end-labeling detection showed that apoptotic cell death was significantly increased in cells with 5-day treatment of antisense H-ras oligodeoxynucleotide (34.0 +/- 4.5%) in comparing with cells without treatment (2.5 +/- 1.2%, t = 13.434, P < 0.01) or treated with non-specific antisense oligodeoxynucleotide (4.8 +/- 1.4%, t = 12.453, P < 0.01) at the corresponding time. In the in vivo experiment, at week 6, no palpable tumor could be found in 50% (3/6) of animals receiving cells with pretreatment of antisense H-ras oligodeoxynucleotide, while 100% (4/4, 4/4) of animals in the 2 control groups developed palpable tumors. Tumor growth in antisense H-ras treated animals was significantly retarded in comparison with that of the untreated (t = 3.509, P < 0.01) or non-specific antisense oligodeoxynucleotide treated animals (t = 3.452, P < 0.01). 75% to 100% of animals in the 2 control groups developed lung metastases, while in antisense H-ras treated animals lung metastasis foci could not be found by random serial section and microscopy (u = 2.536, P < 0.01; u = 3.162, P < 0.01, respectively). CONCLUSIONS: Specific inhibition of H-ras expression by antisense H-ras oligodeoxynucleotides could not only induce apoptotic cell death, inhibit the growth rate of LCI-D20 cells in vitro and in vivo, but also alter in vivo tumorigenesity and metastatic potential of LCI-D20 cells.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/patologia , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Divisão Celular/efeitos dos fármacos , Citometria de Fluxo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/patologia
13.
Blood ; 94(1): 74-86, 1999 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10381500

RESUMO

Erythropoietin (EPO) and its receptor (EPOR) are required for the development of mature erythrocytes. After binding of ligand, the EPOR activates a variety of signaling pathways that ultimately control cellular proliferation, survival, and specific gene expression. Although erythroid progenitors appear to be the principal EPO-responsive cell type in vivo due to the restricted expression of the EPOR, many growth factor-dependent cell lines expressing the EPOR can respond to EPO by activating many or all of these pathways. In the present study, we have identified a cellular context (the interleukin-2 [IL-2]-dependent HT-2 line) in which the EPO stimulation of the EPOR fails to support cellular proliferation, STAT-5 induction, or MAPK activation, despite efficient phosphorylation of the EPOR and JAK2 and inhibition of apoptosis after withdrawal of IL-2. Interestingly, when we fused HT-2 cells expressing the EPOR with Ba/F3 cells in a complementation assay, the resulting hybridomas proliferated and potently activated STAT-5 and MAPK in response to EPO. These data indicate that an unidentified cellular factor is needed to mediate signaling by the EPOR. Moreover, Ba/F3 cells apparently express this factor(s) and somatic fusions can, therefore, confer EPO-responsiveness to HT-2 cells that lack this factor.


Assuntos
Eritrócitos/fisiologia , Eritropoetina/farmacologia , Proteínas do Leite , Receptores da Eritropoetina/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/fisiologia , Linhagem Celular , Proteínas de Ligação a DNA/fisiologia , Ativação Enzimática , Eritropoetina/fisiologia , Humanos , Fator de Transcrição STAT5 , Transativadores/fisiologia
14.
J Biol Chem ; 274(9): 5415-21, 1999 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-10026152

RESUMO

Signal transduction by the erythropoietin receptor (EPOR) is activated by ligand-mediated receptor homodimerization. However, the relationship between extracellular and intracellular domain oligomerization remains poorly understood. To assess the requirements for dimerization of receptor cytoplasmic sequences for signaling, we overexpressed mutant EPORs in combination with wild-type (WT) EPOR to drive formation of heterodimeric (i.e. WT-mutant) receptor complexes. Dimerization of the membrane-proximal portion of the EPOR cytoplasmic region was found to be critical for the initiation of mitogenic signaling. However, dimerization of the entire EPOR cytoplasmic region was not required. To examine this process more closely, we generated chimeras between the intracellular and transmembrane portions of the EPOR and the extracellular domains of the interleukin-2 receptor beta and gammac chains. These chimeras allowed us to assess more precisely the signaling role of each receptor chain because only heterodimers of WT and mutant receptor chimeras form in the presence of interleukin-2. Coexpression studies demonstrated that a functional receptor complex requires the membrane-proximal region of each receptor subunit in the oligomer to permit activation of JAK2 but only one membrane-distal tail to activate STAT5 and to support cell proliferation. Thus, this study defines key relationships involved in the assembly and activation of the EPOR signal transduction complex which may be applicable to other homodimeric cytokine receptors.


Assuntos
Citoplasma/metabolismo , Receptores da Eritropoetina/metabolismo , Sequência de Bases , Biopolímeros , Divisão Celular , Linhagem Celular , Oligodesoxirribonucleotídeos , Receptores da Eritropoetina/química , Receptores da Eritropoetina/genética , Transdução de Sinais
15.
J Exp Clin Cancer Res ; 18(4): 543-8, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10746982

RESUMO

The mRNA and protein expression of HSP70 were studied using RT-PCR and FCM techniques. It's immune protective effects in vivo and the cytotoxicity in vitro were also observed. Results showed that cell viability didn't change under 42-43 degrees C, but declined in 44-45 degrees C; the level of HSP70 mRNA decreased initially (0.5-4.0 hour) but gradually resumed and increased from 8 to 12 hours at 42 degrees C. The positive cells expressed membrane HSP70 were significantly higher in heat shocked group than in a control group (P<0.001); the highest positive rate was 96.8% at 43 degrees C. The C3H mice immunized with heat shocked H22 cells could resist a secondary subcutaneous inoculation of parental H22 cells and their tumorigenic rate was significantly lower than that in mice immunized with parental H22 cells and RPMI 1640 control mice, which were 1/9.7/8 and 8/8, respectively. Their median survival time was also longer than that of parental cell group and RPMI 1640 control group, which were >90 days, 73.5 days, and 39.5 days, respectively. Through heat-treated tumor cell and lymphocyte mixed culture (TLMC), the induced lymphocytes had higher cytotoxic activities than that of splenic cells. The cytotoxicity against H22 cells reached 65.38% (2 hrs, 42 degrees C) and 67.84% (12 hrs, 43 degrees C) and could be blocked by anti-HSP70 McAb. Phenotype analysis revealed that the rate of TCR gammadelta+ cells rose with increasing cytotoxic activity, but no similar changes could be found in the CD4+ CD8+ TCR alphabeta+ subset. These results suggest that proper heat shock conditions can improve the immunogenicity of tumor cells and CD4- CD8- TCR gammadelta+ T carried on cytotoxic function via the HSP70 molecule.


Assuntos
Proteínas de Choque Térmico HSP70/genética , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Animais , Membrana Celular/metabolismo , Sobrevivência Celular , Citotoxicidade Imunológica , Proteínas de Choque Térmico HSP70/biossíntese , Temperatura Alta , Neoplasias Hepáticas Experimentais/imunologia , Neoplasias Hepáticas Experimentais/prevenção & controle , Teste de Cultura Mista de Linfócitos , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Biossíntese de Proteínas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica , Células Tumorais Cultivadas
16.
Nat Struct Biol ; 5(11): 993-1004, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9808045

RESUMO

Dimerization of the erythropoietin (EPO) receptor (EPOR), in the presence of either natural (EPO) or synthetic (EPO-mimetic peptides, EMPs) ligands is the principal extracellular event that leads to receptor activation. The crystal structure of the extracellular domain of EPOR bound to an inactive (antagonist) peptide at 2.7 A resolution has unexpectedly revealed that dimerization still occurs, but the orientation between receptor molecules is altered relative to active (agonist) peptide complexes. Comparison of the biological properties of agonist and antagonist EMPs with EPO suggests that the extracellular domain orientation is tightly coupled to the cytoplasmic signaling events and, hence, provides valuable new insights into the design of synthetic ligands for EPOR and other cytokine receptors.


Assuntos
Eritropoetina/química , Proteínas do Leite , Peptídeos Cíclicos/química , Receptores da Eritropoetina/antagonistas & inibidores , Receptores da Eritropoetina/química , Transdução de Sinais/fisiologia , Sequência de Aminoácidos , Animais , Sequência Conservada/genética , Cristalografia por Raios X , Proteínas de Ligação a DNA/metabolismo , Dimerização , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Fosforilação , Conformação Proteica , Receptores da Eritropoetina/agonistas , Proteínas Recombinantes de Fusão , Fator de Transcrição STAT5 , Transativadores/metabolismo , Triptofano/química , Tirosina/química
17.
Hepatogastroenterology ; 45(22): 1056-61, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9756006

RESUMO

BACKGROUND/AIMS: The aim of this study was to try to understand the effects of the synthetic matrix metalloproteinase inhibitor Batimastat (BB-94) on hepatocellular carcinoma (HCC). METHODOLOGY: An orthotopic metastatic human hepatocellular carcinoma in nude mice model (LCI-D20) was used to study primary tumor growth, local invasion and metastasis of HCC. MTT assay was used to study the effects of BB-94 on cytotoxin and proliferation of HCC cell line SMMC-7721 in vitro. A gelatine zymograph was used to study the expression of MMPs in the LCI-D20 tumor tissue. RESULTS: BB-94 can inhibit primary tumor growth, local invasion, intrahepatic and lung metastasis, as well as prolong survival. BB-94 did not affect the proliferation of HCC cells in vitro. LCI-D20 tumor tissue expresses MMP-2 and MMP-9. CONCLUSIONS: BB-94 has a cytostatic therapeutic effect on HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Metaloendopeptidases/antagonistas & inibidores , Metástase Neoplásica/tratamento farmacológico , Fenilalanina/análogos & derivados , Tiofenos/uso terapêutico , Animais , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/mortalidade , Divisão Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Metaloendopeptidases/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Fenilalanina/farmacologia , Fenilalanina/uso terapêutico , Taxa de Sobrevida , Tiofenos/farmacologia , Células Tumorais Cultivadas
18.
J Cancer Res Clin Oncol ; 124(5): 275-80, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9645459

RESUMO

Resectional therapy has been accepted as the only curative therapy for hepatocellular carcinoma (HCC). Unfortunately, it is estimated that only 10% of HCC are resectable at the time of diagnosis. Cytoreduction and sequential resection offer a new hope for patients with unresectable HCC. Radioimmunotherapy (RIT) is an attractive approach for cytoreduction. We have previously shown that intrahepatic arterial 131I-labelled anti-HCC monoclonal antibody (131I-Hepama-1 mAb) could be used safely in combination with hepatic artery ligation for treatment of unresectable HCC, and encouraging results have been achieved. In this paper, the long-term survival and the prognostic factors in HCC patients treated with radioimmunotherapy will be analysed. Sixty-five patients with surgically verified unresectable HCC were treated with hepatic artery ligation plus hepatic artery cannulation and infusion from 1990 to 1992. Thirty-two patients were enrolled in a phase I-II clinical trial with infusion of 131I-radiolabelled anti-HCC monoclonal antibody (Hepama-1 mAb) via the hepatic artery (the RIT group). Another 33 patients formed the group treated with intrahepatic-arterial chemotherapy (the non-RIT group). T cell subsets were measured in 24 patients and human anti-(murine Ig) antibody (HAMA) were monitored in the RIT group. The 5-year survival rate was significantly higher in the RIT group than in the chemotherapy group, being 28.1% compared to 9.1% (P < 0.05); this was mainly a result of better cytoreduction and a higher sequential resection rate (53.1% compared to 9.1%). Significant prognostic factors in the RIT group included tumour capsule status and the number of tumour nodules. HAMA incidence and CD4+ T lymphocytes influenced short-term, but not long-term survival. It is suggested that intrahepatic-arterial RIT, using 131I-Hepama-1 mAb, combined with hepatic artery ligation might be an effective approach to improve long-term survival in some patients with unresectable HCC, which may successfully be made resectable by intra-arterial infusion of 131I-Hepama-1 mAb.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/radioterapia , Radioisótopos do Iodo/uso terapêutico , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/radioterapia , Radioimunoterapia/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Resultado do Tratamento
19.
Proc Natl Acad Sci U S A ; 95(12): 7006-11, 1998 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-9618529

RESUMO

Erythropoietin (EPO) is required for red blood cell development, but whether EPO-specific signals directly instruct erythroid differentiation is unknown. We used a dominant system in which constitutively active variants of the EPO receptor were introduced into erythroid progenitors in mice. Chimeric receptors were constructed by replacing the cytoplasmic tail of constitutively active variants of the EPO receptor with tails of diverse cytokine receptors. Receptors linked to granulocyte or platelet production supported complete erythroid development in vitro and in vivo, as did the growth hormone receptor, a nonhematopoietic receptor. Therefore, EPOR-specific signals are not required for terminal differentiation of erythrocytes. Furthermore, we found that cellular context can influence cytokine receptor signaling.


Assuntos
Eritrócitos/fisiologia , Eritropoese/fisiologia , Eritropoetina/fisiologia , Receptores da Eritropoetina/fisiologia , Células 3T3 , Animais , Diferenciação Celular/fisiologia , Eritrócitos/citologia , Camundongos , Proteínas Recombinantes de Fusão/fisiologia , Transdução de Sinais , Transfecção
20.
Curr Opin Immunol ; 10(3): 271-8, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9638363

RESUMO

The JAK/STAT pathway is recognized as one of the major mechanisms by which cytokine receptors transduce intracellular signals. This system is regulated at multiple levels, including JAK activation, nuclear trafficking of STAT factors, and negative feedback loops. Gene deletion studies have implicated selected STAT factors as predominant mediators for a limited number of lymphokines. This signaling pathway influences normal cell survival and growth mechanisms and may contribute to oncogenic transformation.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica/fisiologia , Proteínas Tirosina Quinases/fisiologia , Receptores de Citocinas/fisiologia , Transdução de Sinais/fisiologia , Transativadores/fisiologia , Animais , Apoptose/fisiologia , Transformação Celular Neoplásica , Proteínas de Ligação a DNA/genética , Dimerização , Retroalimentação , Regulação da Expressão Gênica/efeitos dos fármacos , Marcação de Genes , Genes Letais , Interferons/fisiologia , Camundongos , Camundongos Knockout , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Tirosina Quinases/deficiência , Proteínas Tirosina Quinases/genética , Receptores de Citocinas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transativadores/deficiência , Transativadores/genética , Domínios de Homologia de src
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