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1.
Zhonghua Gan Zang Bing Za Zhi ; 31(1): 90-95, 2023 Jan 20.
Artículo en Chino | MEDLINE | ID: mdl-36948855

RESUMEN

Objective: To compare the safety and efficacy of transmesenteric vein extrahepatic portosystemic shunt (TEPS) and transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of cavernous transformation of the portal vein (CTPV). Methods: The clinical data of CTPV patients with patency or partial patency of the superior mesenteric vein treated with TIPS or TEPS treatment in the Department of Vascular Surgery of Henan Provincial People's Hospital from January 2019 to December 2021 were selected. The differences in baseline data, surgical success rate, complication rate, incidence rate of hepatic encephalopathy, and other related indicators between TIPS and TEPS group were statistically analyzed by independent sample t-test, Mann-Whitney U test, and Chi-square test. Kaplan-Meier survival curve was used to calculate the cumulative patency rate of the shunt and the recurrence rate of postoperative portal hypertension symptoms in both groups. Results: The surgical success rate (100% vs. 65.52%), surgical complication rate (6.67% vs. 36.84%), cumulative shunt patency rate (100% vs. 70.70%), and cumulative symptom recurrence rate (0% vs. 25.71%) of the TEPS group and TIPS group were statistically significantly different (P < 0.05). The time of establishing the shunt [28 (2141) min vs. 82 (51206) min], the number of stents used [1 (12) vs. 2 (15)], and the length of the shunt [10 (912) cm vs. 16 (1220) cm] were statistically significant between the two groups (t = -3.764, -4.059, -1.765, P < 0.05). The incidence of postoperative hepatic encephalopathy in the TEPS group and TIPS group was 6.67% and 15.79% respectively, with no statistically significant difference (Fisher's exact probability method, P = 0.613). The pressure of superior mesenteric vein decreased from (29.33 ± 1.99) mmHg to (14.60 ± 2.80) mmHg in the TEPS group and from (29.68 ± 2.31) mmHg to (15.79 ± 3.01) mmHg in TIPS group after surgery, and the difference was statistically significant (t = 16.625, 15.959, P < 0.01). Conclusion: The best indication of TEPS is in CTPV patients with patency or partial patency of the superior mesenteric vein. TEPS improves the accuracy and success rate of surgery and reduces the incidence of complications.


Asunto(s)
Encefalopatía Hepática , Hipertensión Portal , Derivación Portosistémica Intrahepática Transyugular , Humanos , Vena Porta/cirugía , Derivación Portosistémica Intrahepática Transyugular/métodos , Encefalopatía Hepática/etiología , Resultado del Tratamiento , Hipertensión Portal/cirugía , Hipertensión Portal/complicaciones , Estudios Retrospectivos , Hemorragia Gastrointestinal/etiología
2.
Zhonghua Gan Zang Bing Za Zhi ; 29(8): 754-758, 2021 Aug 20.
Artículo en Chino | MEDLINE | ID: mdl-34517456

RESUMEN

Objective: To evaluate the short- and medium-term clinical efficacy of TIPS approach combined with AngioJet thrombus aspiration technology treatment in acute portal vein thrombosis. Methods: 63 cases with acute portal vein thrombosis treated in our center from May 2017 to July 2019 were studied retrospectively, including 49 males and 14 females, aged 35-61 (46 ± 5) years. TIPS approach (with/without) combined with Angiojet thrombus aspiration and gastroesophageal varices embolization was performed simultaneously according to the patient's condition. Regular follow-up for 3-33 (22 ± 3) months after surgery was used to observe the curative effect. Results: The technical success rate was 100%. Portal vein and superior mesenteric vein blood flow were returned to normal after the operation. Two cases of biliary tract injury were untreated. Simultaneously, two cases of intrahepatic arteriovenous fistula were treated with superselective arterial embolization. During the follow-up period, 47 cases (74.61%) had complete portal vein recanalization, 13 cases (20.63%) had partial recanalization, 3 cases (4.76%) had complete portal cavernoma, 7 cases (11.11%) had symptomatic hepatic encephalopathy, 1 case had received artificial liver treatment (1.59%), 1 case had peptic ulcer (11.11%), 6 cases (9.52%) had lost to follow-up, and there was no portal hypertension-related bleeding or death. Conclusion: TIPS approach combined with AngioJet thrombus aspiration technology is safe, effective and feasible in the treatment of acute portal vein thrombosis, and the short- and medium-term clinical effects are satisfactory.


Asunto(s)
Derivación Portosistémica Intrahepática Transyugular , Trombosis , Femenino , Humanos , Masculino , Vena Porta/cirugía , Estudios Retrospectivos , Tecnología , Resultado del Tratamiento
3.
Eur Rev Med Pharmacol Sci ; 24(2): 878-884, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-32016994

RESUMEN

OBJECTIVE: To explore the mechanism underlying micro ribonucleic acid (miR)-21 in the invasion of rat aortic aneurysm cells in vitro by regulating matrix metalloproteinase (MMP)-2 and MMP-9. MATERIALS AND METHODS: Rats were randomly divided into three groups: control group, model group, and miR-21 group. Real Time fluorescence quantitative Polymerase Chain Reaction (qRT-PCR) was adopted to detect the levels of miR-21 in each group of cells, transwell assay was performed to measure the effect of miR-21 on the invasion of aortic aneurysm cells. Western blotting was used to examine the expression of PTEN, which is the predicted target of miR-21 in aortic aneurysm cells, as well as the expressions of invasion-related proteases, MMP-2 and MMP-9. RESULTS: The expression level of miR-21 in thoracic aortic aneurysm cells in model group was significantly higher than that in normal group (p<0.05), and that in miR-21 group was remarkably higher than that in model group (p<0.05). MiR-21 group had evidently more aortic aneurysm cells and stronger cell invasion ability than normal group and model group (p<0.05). In addition, the expression level of PTEN in model group was significantly higher than that in normal group (p<0.05), while that in miR-21 group notably declined compared to model group, (p<0.05). Compared with normal group and model group, the expressions of MMP-2 and MMP-9 were markedly increased in miR-21 group (p<0.05). CONCLUSIONS: In aortic aneurysm cells of rats, miR-21 could suppress the expression of PTEN and activate MMP-2 and MMP-9 signals to promote the proliferation and migration of aortic aneurysm cells.


Asunto(s)
Aneurisma de la Aorta Torácica/enzimología , Regulación Enzimológica de la Expresión Génica , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 9 de la Matriz/biosíntesis , MicroARNs/biosíntesis , Animales , Aneurisma de la Aorta Torácica/genética , Aneurisma de la Aorta Torácica/patología , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Femenino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , MicroARNs/genética , Fosfohidrolasa PTEN/antagonistas & inhibidores , Fosfohidrolasa PTEN/biosíntesis , Fosfohidrolasa PTEN/genética , Ratas
4.
Blood ; 96(9): 3056-63, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11049984

RESUMEN

Tissue factor, which is expressed in vascular lesions, increases thrombin production, blood coagulation, and smooth muscle cell proliferation. We demonstrate that oxidized low-density lipoprotein (LDL) induces surface tissue factor pathway activity (ie, activity of the tissue factor:factor VIIa complex) on human and rat smooth muscle cells. Tissue factor messenger RNA (mRNA) was induced by oxidized LDL or native LDL; however, native LDL did not markedly increase tissue factor activity. We hypothesized that oxidized LDL mediated the activation of the tissue factor pathway via an oxidant-dependent mechanism, because antioxidants blocked the enhanced tissue factor pathway activity by oxidized LDL, but not the increased mRNA or protein induction. We separated total lipid extracts of oxidized LDL using high-performance liquid chromatography (HPLC). This yielded 2 major peaks that induced tissue factor activity. Of the known oxysterols contained in the first peak, 7alpha- or 7beta-hydroxy or 7-ketocholesterol had no effect on tissue factor pathway activity; however, 7beta-hydroperoxycholesterol increased tissue factor pathway activity without induction of tissue factor mRNA. Tertiary butyl hydroperoxide also increased tissue factor pathway activity, suggesting that lipid hydroperoxides, some of which exist in atherosclerotic lesions, activate the tissue factor pathway. We speculate that thrombin production could be elevated via a mechanism involving peroxidation of cellular lipids, contributing to arterial thrombosis after plaque rupture. Our data suggest a mechanism by which antioxidants may offer a clinical benefit in acute coronary syndrome and restenosis.


Asunto(s)
Peroxidación de Lípido , Lipoproteínas LDL/fisiología , Músculo Liso Vascular/fisiología , Tromboplastina/genética , Transcripción Genética , Sal Disódica del Ácido 1,2-Dihidroxibenceno-3,5-Disulfónico/farmacología , Animales , Antioxidantes/farmacología , Aorta/fisiología , Azoles/farmacología , Células Cultivadas , Deferoxamina/farmacología , Humanos , Isoindoles , Cinética , Lipoproteínas LDL/sangre , Lipoproteínas LDL/aislamiento & purificación , Lipoproteínas LDL/farmacología , Músculo Liso Vascular/efectos de los fármacos , Compuestos de Organoselenio/farmacología , Ratas , Ratas Sprague-Dawley , Tromboplastina/fisiología , Compuestos de Estaño/farmacología , Transcripción Genética/efectos de los fármacos
5.
Biomed Environ Sci ; 13(4): 287-92, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11351862

RESUMEN

To study the suppression effect of light rare earth elements (RE) on proliferation of two cancer cell lines. Two cancer cell lines PAMC82 and K562 were used to examine their colony-forming ability in soft agar, microtubule structure, calmodulin levels and regulation of some gene expressions by Northern blot analysis with and without treatment by RE. The results showed that on soft agar culture the colony-forming ability of human gastric cancer cell line PAMC82 treated by RE chloride decreased and the PAMC82 cell microtubule abnormal structure became normal. The calmodulin (CaM) levels decreased in human leukemia cells (K562) treated with cerium chloride and neodymium chloride. The Northern blot analysis revealed marked up-regulation of p53, p16(MTS1), p21 (WAF1) gene expressions in PAMC82 cells treated with lanthanum chloride and cerium chloride, as compared to control PAMC82 cells. The light rare earth elements studied have certain suppression effects on proliferation of cancer cells. This effect might be related to the decrease of calmodulin and up-regulation of some gene expressions in cancer cells.


Asunto(s)
Metales de Tierras Raras/farmacología , Células Tumorales Cultivadas/efectos de los fármacos , Calmodulina/análisis , División Celular/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Genes Supresores de Tumor , Humanos , Leucemia , Microtúbulos/ultraestructura , Neoplasias Gástricas , Células Tumorales Cultivadas/metabolismo , Células Tumorales Cultivadas/ultraestructura
6.
J Biol Chem ; 274(46): 32543-6, 1999 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-10551805

RESUMEN

Presenilin-1 (PS-1) is the most causative Alzheimer gene product, and its function is not well understood. In an attempt to elucidate the function of PS-1, we screened a human brain cDNA library for PS-1-interacting proteins using the yeast two-hybrid system and isolated a novel protein containing a PSD-95/Dlg/ZO-1 (PDZ)-like domain. This novel PS-1-associated protein (PSAP) shares a significant similarity with a Caenorhabditis elegans protein of unknown function. Northern blot analysis revealed that PSAP is predominantly expressed in the brain. Deletion of the first four C-terminal amino acid residues of PS-1, which contain the PDZ domain-binding motif (Gln-Phe-Tyr-Ile), reduced the binding activity of PS-1 toward PSAP 4-fold. These data suggest that PS-1 may associate with a PDZ-like domain-containing protein in vivo and thus may participate in receptor or channel clustering and intracellular signaling events in the brain.


Asunto(s)
Proteínas de Drosophila , Proteínas de Insectos/química , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas Mitocondriales , Proteínas del Tejido Nervioso/química , Fosfoproteínas/química , Proteínas Supresoras de Tumor , Secuencia de Aminoácidos , Sitios de Unión , Encéfalo/metabolismo , Línea Celular , Clonación Molecular , Expresión Génica , Humanos , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/genética , Fragmentos de Péptidos/metabolismo , Fosforilación , Presenilina-1 , Unión Proteica/genética , ARN Mensajero/metabolismo , Alineación de Secuencia , Transfección , Proteína de la Zonula Occludens-1
7.
J Biol Chem ; 274(46): 32795-802, 1999 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-10551840

RESUMEN

Tissue factor, in association with factor VIIa, initiates the coagulation cascade. We studied the influences of two pathophysiological stimuli, native (unmodified) and oxidized low density lipoprotein, on tissue factor gene expression in a cell important in vascular remodeling and vascular diseases, the smooth muscle cell. Our results demonstrated that both lipoproteins significantly induced tissue factor gene expression in rat aortic smooth muscle cells; oxidized low density lipoprotein was slightly more potent. Both lipoproteins increased tissue factor mRNA in a concentration- and time-dependent manner. Results from nuclear run-on assays and mRNA stability experiments indicated that increased tissue factor mRNA accumulation in response to the lipoproteins was principally controlled at the transcriptional level. By using lipid extracts of low density lipoprotein or methylation of the intact lipoprotein to block receptor recognition, we showed that this lipoprotein induced tissue factor mRNA via both receptor-independent and receptor-augmented pathways. Transfection studies using a series of deleted tissue factor promoters revealed that a -143- to +106-base pair region of the rat tissue factor promoter contained regulatory elements required for lipoprotein-mediated induction. Electrophoretic mobility shift assays showed that the binding activities of the transcription factor Egr-1, but not Sp1, were markedly elevated in response to these lipoproteins. Transfection of site-directed mutants of the tissue factor (TF) promoter demonstrated that not only Egr-1 but also Sp1 cis-acting elements in the TF (-143) promoter construct were necessary for optimal TF gene induction. Our data show for the first time that both low density lipoprotein and oxidized low density lipoprotein induce tissue factor gene expression in smooth muscle cells and that this tissue factor gene expression is mediated by both Egr-1 and Sp1 transcription factors.


Asunto(s)
Lipoproteínas LDL/farmacología , Músculo Liso Vascular/metabolismo , Tromboplastina/genética , Animales , Secuencia de Bases , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Cinética , Lipopolisacáridos/farmacología , Datos de Secuencia Molecular , Músculo Liso Vascular/efectos de los fármacos , Mutación , Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas , Conejos , Ratas , Receptores de LDL/metabolismo , Tromboplastina/biosíntesis , Activación Transcripcional , Transfección
8.
Circulation ; 99(13): 1753-9, 1999 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-10190887

RESUMEN

BACKGROUND: Tissue factor, which is required for the initiation of the extrinsic coagulation cascade, is known to be upregulated in cells within atherosclerotic lesions, including smooth muscle cells. Tissue factor expression on the smooth muscle cell surface could be of pathological significance as a contributor to plaque growth, thrombus formation, and the acute coronary syndrome after plaque rupture. METHODS AND RESULTS: In this study, we show that LDL increased tissue factor mRNA and cell surface protein in smooth muscle cells without a marked increase in surface tissue factor activity. Hydrogen peroxide activated tissue factor on the cell surface but did not increase tissue factor mRNA or cell surface protein. Sequentially added LDL and hydrogen peroxide increased mRNA, cell surface protein, and activity; surface activity was greater than that observed with hydrogen peroxide alone. The action of hydrogen peroxide did not involve a regulatory mechanism associated with the cytoplasmic tail of tissue factor because a truncated tissue factor lacking the cytoplasmic tail was activated by hydrogen peroxide. CONCLUSIONS: These results suggest a novel 2-step pathway for increased tissue factor activity on smooth muscle cell surfaces in which lipoproteins regulate synthesis of a latent tissue factor and oxidants activate the protein complex.


Asunto(s)
LDL-Colesterol/farmacología , Músculo Liso Vascular/metabolismo , Tromboplastina/metabolismo , Animales , Membrana Celular/metabolismo , Células Cultivadas , Citoplasma/química , Activación Enzimática/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/farmacología , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , Estructura Terciaria de Proteína , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Tromboplastina/biosíntesis , Tromboplastina/genética
9.
J Biol Chem ; 271(5): 2731-9, 1996 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-8576248

RESUMEN

Tissue factor (TF) gene expression is rapidly induced in epithelial cells by phorbol 12-myristate 13-acetate and serum. We have shown that this induction is mediated by a novel serum response region (SRR) (-111 to +14 bp) within the human TF promoter. In this study, we characterized cis-acting genetic elements within the SRR that regulated basal and inducible expression of the TF gene in HeLa cells. Gel mobility shift assays using oligonucleotides spanning the entire SRR identified three 12-base pair (bp) motifs within subregions 1, 2, and 3 that bound constitutively expressed Sp1 and inducibly expressed EGR-1. Analysis of protein binding to these 12-bp motifs by competition with Sp1 and EGR-1 sites, mutation, and antibody supershift experiments indicated that they each contained distinct EGR-1 and Sp1 sites that overlapped by 6 bp. Functional studies using HeLa cells transfected with plasmids containing the wild-type TF promoter (-111 to +14 bp) or derivatives containing mutations in the three Sp1 and/or EGR-1 sites examined basal and inducible expression. The Sp1 sites mediated basal promoter activity, and both Sp1 and EGR-1 sites were required for maximal induction of the TF promoter by phorbol 12-myristate 13-acetate or serum. These data indicated that TF gene expression in HeLa cells was regulated by both Sp1 and EGR-1.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica , Proteínas Inmediatas-Precoces , Factor de Transcripción Sp1/metabolismo , Tromboplastina/genética , Factores de Transcripción/metabolismo , Transcripción Genética , Secuencia de Bases , Proteína 1 de la Respuesta de Crecimiento Precoz , Inducción Enzimática , Células HeLa , Humanos , Luciferasas/biosíntesis , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Regiones Promotoras Genéticas , Unión Proteica , Proteínas Recombinantes/metabolismo , Acetato de Tetradecanoilforbol/farmacología
10.
Cytokine ; 7(6): 491-502, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8580364

RESUMEN

Leukaemia Inhibitory Factor (LIF), an interleukin 6 (IL-6)-type cytokine, is an essential growth factor for murine embryonal stem cells. The LIF-receptor was known in these cells, but the cell-internal part of the signal cascade and the transcription factors through which LIF controls its growth-promoting target genes in embryonal stem cells, had not been identified. This study shows that the type II IL-6-response element of the rat alpha 2 macroglobulin (alpha 2M) gene, which mediates IL-6- and LIF-responses in hepatic cells, also functioned as a LIF-response element (LIF-RE) in ES1 embryonal stem cells and P19 embryonal carcinoma cells. It conferred transcriptional activation by LIF of transfected reporter constructs in these cells. A characteristic DNA-binding activity interacting with this LIF-RE was induced by treatment of these cells with LIF. The complex between this activity and the LIF-RE had identical electrophoretic mobility, sequence-specificity and kinetics of induction as the complex with the corresponding LIF-response factor (LIF-RF) from hepatic cells. The transcription factor STAT3 was part of this complex, as shown by its reactivity with anti-STAT3 antibodies. Withdrawal of LIF from ES1 cells caused the induction of differentiation and the disappearance of this DNA-binding activity. Simultaneously, the surface density of high-affinity LIF receptors was reduced approximately 10-fold.


Asunto(s)
Inhibidores de Crecimiento/genética , Interleucina-6 , Linfocinas/genética , Secuencias Reguladoras de Ácidos Nucleicos , Células Madre/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , alfa-Macroglobulinas/genética , Secuencia de Aminoácidos , Animales , Diferenciación Celular/efectos de los fármacos , Línea Celular , Regulación hacia Abajo/efectos de los fármacos , Células Madre de Carcinoma Embrionario , Inhibidores de Crecimiento/farmacología , Factor Inhibidor de Leucemia , Linfocinas/farmacología , Ratones , Datos de Secuencia Molecular , Células Madre Neoplásicas , Ratas , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Células Madre/metabolismo
11.
J Immunol ; 154(7): 3266-74, 1995 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-7534794

RESUMEN

Inflammatory genes are regulated in cells of monocyte (Mo) lineage by a variety of cellular encounters, including adhesion mediated by integrins. The role of the beta 1 family of integrins in the direct induction of immediate early gene expression was analyzed by using the tissue factor (TF) gene. Engagement of alpha 4 or beta 1 on Mo, but not members of the beta 2 integrin family, with specific mAbs as surrogate ligands immediately and directly induced high level surface expression of TF, and accumulation of TF mRNA, as well as production of TNF-alpha and HIV-1 virus. The mechanism responsible for induction of TF gene transcription mediated by the engagement of alpha 4 or beta 1 was elucidated by using THP-1 monoblastic leukemia cells. Functional analysis of plasmids containing the TF promoter expressing the luciferase reporter gene identified a cis-acting integrin-responsive element (InRE), which contained two AP-1 sites as well as a single kappa B-like site. Mutation of either the AP-1 sites or kappa B-like site greatly diminished responsiveness to integrin engagement. This InRE also conferred responsiveness to a heterologous promoter in the same reporter plasmid. Binding of mAbs to either alpha 4 or beta 1 led to nuclear translocation of the c-Rel/p65 heterodimer that preferentially bound to the TF kappa B-like site. In contrast, constitutive binding of AP-1 proteins to the two AP-1 sites was not increased by alpha 4 or beta 1 integrin engagement. These studies expand knowledge of integrin regulation of immediate early gene expression in Mo and molecular encounters that are inferred to play an active role in Mo effector functions.


Asunto(s)
Integrinas/fisiología , Macrófagos/metabolismo , Tromboplastina/biosíntesis , Secuencia de Bases , Northern Blotting , Línea Celular , Regulación de la Expresión Génica/fisiología , VIH-1/metabolismo , Humanos , Integrina alfa4 , Integrina beta1 , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , ARN Mensajero/biosíntesis , Transducción de Señal , Tromboplastina/genética , Transfección/genética , Factor de Necrosis Tumoral alfa/biosíntesis
12.
Arterioscler Thromb ; 14(5): 807-14, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8172857

RESUMEN

Cell-specific expression of tissue factor (TF) in vivo is consistent with its primary role in hemostasis. In addition, TF expression is induced in cultured cells by a variety of agents, including serum and growth factors, which define the TF gene as a "primary response" gene. In this study we examined the signaling pathways and cis-acting regulatory elements required for induction of TF gene expression in HeLa cells in response to serum and the tumor promoter, phorbol 12-myristate 13-acetate (PMA). TF activity and mRNA were induced greater than sixfold in quiescent HeLa cells by serum and PMA. TF mRNA induction by both agonists required intracellular Ca2+ mobilization, whereas inhibition of protein kinase C abolished induction of the TF gene by PMA but had no effect on induction by serum. Functional studies demonstrated that a region of the human TF promoter between -96 and +121 bp contained regulatory elements required for serum and PMA induction. These data indicate that different signaling pathways regulate TF gene expression in response to serum and PMA, although the same cis-acting DNA elements may mediate induction.


Asunto(s)
Fenómenos Fisiológicos Sanguíneos , Acetato de Tetradecanoilforbol/farmacología , Tromboplastina/genética , Secuencia de Bases , Calcio/metabolismo , Cicloheximida/farmacología , Regulación de la Expresión Génica , Genes Reguladores , Células HeLa , Humanos , Datos de Secuencia Molecular , Proteína Quinasa C/fisiología , ARN Mensajero/análisis , Tromboplastina/biosíntesis
14.
Biomed Environ Sci ; 1(3): 270-6, 1988 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2855920

RESUMEN

Studies on the toxicity and safety of a mixture of rare earth metal nitrates (Ce, La, Nd, Pr, and Sm) used in agricultural operations are reported. In mice, rats, and guinea pigs, the oral LD50 ranged from 1397 to 1876 mg/kg; absorption in the gastrointestinal tract was low. The accumulation coefficient was greater than 5. In rabbits, a topical application of a suspension of 500 mg/ml produced mild irritation of the skin and eye mucosa. Subchronic and chronic toxicity studies were done at different dose levels in monkeys (100 mg/kg) and rats (200 and 1800 mg/kg); biochemical and histopathological examination of tissues showed no abnormal or specific pathological changes. In chronic feeding studies with rats, the incidence of tumors and malignant tumors in test groups was lower than that in the control. Rat fetuses did not show any teratogenicity when the dams were orally fed up to 330 mg/kg of this nitrate mixture. Ames mutagenicity tests were negative at a 50 mg/kg level. The results indicate that an oral dose of 60 mg/kg should be considered as a no-effect level with an ADI of 0.6 mg/kg and that the level of rare earth nitrates used in Chinese agriculture is within acceptable risk or safety limits.


Asunto(s)
Fertilizantes/toxicidad , Metales de Tierras Raras/toxicidad , Administración Oral , Animales , Aberraciones Cromosómicas , Femenino , Cobayas , Pruebas Hematológicas , Pruebas Inmunológicas , Masculino , Metales de Tierras Raras/administración & dosificación , Ratones , Pruebas de Micronúcleos , Pruebas de Mutagenicidad , Nitratos/toxicidad , Ratas , Ratas Endogámicas , Salmonella typhimurium/genética , Espermatozoides/efectos de los fármacos , Teratógenos , Testículo/citología , Testículo/efectos de los fármacos
15.
Int Arch Occup Environ Health ; 52(3): 281-4, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6629516

RESUMEN

A simple and selective method to detect thiodiglycolic acid (TdGA) in urine by flame-photometric-detector (FPD) of gas chromatograph (GC) is described. The detection limit of this method is less than 1 ng without disturbances. Urine from 64 subjects exposed to different air concentration of vinyl chloride (VCM) from 0.3 ppm to more than 100 ppm in three groups and 78 subjects was detected in this way. A comparison of the results of these groups shows significant differences between the control and two exposed groups.


Asunto(s)
Contaminantes Ocupacionales del Aire/toxicidad , Tioglicolatos/orina , Cloruro de Vinilo/toxicidad , Compuestos de Vinilo/toxicidad , Humanos , Fotometría
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