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1.
Zhonghua Bing Li Xue Za Zhi ; 53(6): 598-604, 2024 Jun 08.
Artículo en Zh | MEDLINE | ID: mdl-38825906

RESUMEN

Objective: To investigate the clinicopathological, immunophenotypic and molecular genetic characteristics, and differential diagnosis of NTRK-rearranged spindle cell neoplasms (NTRK-RSCNs) in the gastrointestinal tract. Methods: Two NTRK-RSCNs diagnosed at the Department of Pathology of the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China and one case diagnosed at Zhengzhou Central Hospital, Zhengzhou, China from 2019 to 2022 were collected. The clinical data, histopathology, immunophenotypes and prognosis were analyzed. Fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) were used to detect NTRK gene rearrangements, while relevant literature was also reviewed and discussed. Results: Two patients were male and one was female, with the age of 17, 47 and 62 years, respectively. The tumors were located in the duodenum, ascending colon and descending colon, respectively. The tumors were protuberant masses with gray and rubbery sections. Their maximum diameter was 2.5, 5.0 and 10.0 cm, respectively. Histologically, the tumors invaded mucosa, intrinsic muscle and serosal adipose tissue. Tumor cells consisted of spindle or oval shaped cells with monotonous morphology and arranged in bundles or stripes pattern. Spindle cells were mildly to moderately atypical, with slightly eosinophilic cytoplasm and inconspicuous nucleoli. Necrosis and mitotic figures were observed in one high-grade tumor. All tumors expressed CD34, S-100 and pan-TRK in varying degrees. FISH analysis showed that NTRK1 gene was break-apart in 1 case and NTRK2 gene break-apart in 2 cases. NGS technologies showed LMNA::NTRK1 fusion in one case, STRN::NTRK2 fusion in another case. All patients recovered well after the surgery without recurrence at the end of the follow-up. Conclusions: NTRK-RSCN is rarely diagnosed in the gastrointestinal tract and has significant variations in morphology. It overlaps with various other mesenchymal tumors which should be considered as differential diagnoses. Be familiar with the features of histological morphology in combination with immunophenotype and molecular genetic characteristics can not only help diagnose NTRK-RSCNs, but provide therapeutic targets for clinical treatment.


Asunto(s)
Neoplasias Gastrointestinales , Hibridación Fluorescente in Situ , Receptor trkA , Humanos , Masculino , Femenino , Persona de Mediana Edad , Receptor trkA/genética , Receptor trkA/metabolismo , Neoplasias Gastrointestinales/genética , Neoplasias Gastrointestinales/patología , Adolescente , Reordenamiento Génico , Diagnóstico Diferencial , Secuenciación de Nucleótidos de Alto Rendimiento , Receptor trkB/genética , Receptor trkB/metabolismo
2.
Zhonghua Wai Ke Za Zhi ; 60(11): 987-991, 2022 Nov 01.
Artículo en Zh | MEDLINE | ID: mdl-36323580

RESUMEN

In recent years, great progress has been made in the treatment of Stanford type B aortic dissection, especially endovascular repair technology has become the main treatment. However, it is only used to repair the primary tear, the residual tears and false lumen are often left at the distal end, which causes adverse events such as distal aortic dilatation or even rupture. At present, there are many studies on the influencing factors of aortic remodeling, which provide some references for the prognosis of patients.The aorta carries the transportation of blood flow, and various factors affecting hemodynamics also affect the remodeling of aorta. Some researchers reported several factors related to negative remodeling and added auxiliary techniques, and achieved gratifying results. However, because of the different conditions of each patient, the specific treatment method is still unclear, the factors affecting the aortic remodeling effect also have not been thoroughly studied. Clarifying the influencing factors of negative remodeling is helpful to screen high-risk patients, optimize the treatment plan and improve the prognosis.


Asunto(s)
Aneurisma de la Aorta Torácica , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Humanos , Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/efectos adversos , Procedimientos Endovasculares/métodos , Resultado del Tratamiento , Aorta , Factores de Riesgo , Estudios Retrospectivos
3.
Zhonghua Bing Li Xue Za Zhi ; 47(12): 941-944, 2018 Dec 08.
Artículo en Zh | MEDLINE | ID: mdl-30522176

RESUMEN

Objective: To investigate the clinicopathological features of gangliocytic paraganglioma(GP). Methods: Clinical data and pathological diagnosis of the 4 cases of GP were obtained through the medical record inquiry from January 2011 to December 2017 at the First Affiliated Hospital of Zhengzhou University. Routine HE staining and immunohistochemistry of CKpan, Syn, CgA, CD56, NSE and NF were performed. Clinical follow-up of the patients was obtained through telephone communication. Results: All 4 patients, including 2 male and 2 female patients, presented with intermittent abdominal pain and distention. The median age was 56 years. Preoperative CT showed local thickening of the duodenum wall with slight enhancement in all four cases. Endoscopic ultrasonography showed low level echo in the mucous layer and submucosa involved by the tumor in 3 of 4 cases. The maximal diameter of the tumor ranged from 0.6 to 1.8 cm with an average of 1.2 cm. Microscopically, the tumors consisted of epithelioid, spindle and ganglion-like cells, and the proportion of the three cell types was different among cases. Epithelioid cells expressed CKpan, Syn, CgA and CD56. Spindle cells expressed S-100 protein and SOX-10 and ganglion-like cells expressed NF, Syn, CgA and CD56.All tumour cells expressed NSE. All 4 patients had no recurrence a post-surgery follow-up period of 3 to 30 months. Conclusions: GP of the duodenum is a benign tumor with excellent prognosis after endoscopic excision. Although its incidence is very low, its diagnosis should be considered for any mass lesion of the duodenum, especially involving mucosa and submucosa of the second dudenal segment.


Asunto(s)
Neoplasias Duodenales/química , Neoplasias Duodenales/patología , Paraganglioma/química , Paraganglioma/patología , Antígeno CD56/análisis , Proteínas Portadoras/análisis , Creatina Quinasa/análisis , Neoplasias Duodenales/diagnóstico por imagen , Femenino , Hormonas Glicoproteicas de Subunidad alfa/análisis , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Oligodesoxirribonucleótidos , Paraganglioma/diagnóstico por imagen , Pronóstico , Proteínas S100 , Sinapsinas/análisis
4.
Zhonghua Gan Zang Bing Za Zhi ; 24(9): 676-680, 2016 Sep 20.
Artículo en Zh | MEDLINE | ID: mdl-27788724

RESUMEN

Objective: To investigate the value of spectral CT-based quantitative analysis in the differential diagnosis of liver cancer and liver abscess. Methods: A total of 70 patients with space-occupying lesions in the liver(45 with liver cancer and 25 with liver abscess)underwent spectral CT scans to obtain spectral images in the arterial phase and portal venous phase. The solid constituents of lesions and the iodine and water concentrations in necrotic or cystic parts of lesions, normal hepatic tissue, and abdominal aorta in the arterial phase and portal venous phase were measured, and the normalized iodine concentration(NIC)and lesion-to-normal hepatic tissue ratio(LNR)of iodine concentration were calculated. The two samples t-test and the receiver operating characteristic(ROC)curve analysis were performed for the quantitative indices above. Results: The patients with liver cancer had higher NIC and LNR in solid constituents in the arterial phase than those with liver abscess(NIC: 0.15±0.06 mg/ml vs 0.14±0.02 mg/ml, P > 0.05; LNR: 2.78±0.65 vs 1.45±0.88, P < 0.001). The patients with liver abscess had significantly higher NIC and LNR in solid constituents in the portal venous phase than those with liver cancer(NIC: 0.65±0.08 mg/ml vs 0.52±0.08 mg/ml, P≤0.001; LNR: 1.22±0.23 vs 0.95±0.15, P≤0.001). There were no significant differences in NIC in the arterial phase or NIC and LNR in the portal venous phase in necrotic or cystic parts of lesions between the patients with liver cancer and liver abscess(P > 0.05). The optimal quantitative value for the differential diagnosis of liver cancer and liver abscess was LNR in arterial phase, and the cut-off value of 1.53 had a sensitivity of 100% and a specificity of 92%. Conclusion: Quantitative iodine concentration analysis in spectral CT imaging has a certain value in the differential diagnosis of liver cancer and liver abscess and can improve the accuracy of diagnosis.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Absceso Hepático/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Arterias , Carcinoma Hepatocelular/patología , Medios de Contraste , Diagnóstico Diferencial , Femenino , Humanos , Yodo , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Necrosis/diagnóstico por imagen , Vena Porta/diagnóstico por imagen , Curva ROC , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tomografía Computarizada Espiral/métodos
5.
Genet Mol Res ; 14(3): 8366-74, 2015 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-26345763

RESUMEN

Physical localization of molecular markers and assignment of the 15th linkage group to chromosome 11 of the karyotype in cassava (Manihot esculenta Crantz) were achieved using primed in situ labeling. Amplified signals for both the EST507-1 and SSRY13-5 markers were consistently observed in different stages of cell division. A comparison of the length, arm ratio, and other morphological characteristics of somatic metaphase chromosomes in karyotype analysis indicated that the EST507-1 and SSRY13-5 markers were localized on the short and long arm of cassava chromosome 11 with the relative map positions of 41.67 and 23.07, respectively. The physical localization of the 2 markers on chromosome 11 of the karyotype corresponds to their positions on the 15th linkage group in cassava.


Asunto(s)
Ligamiento Genético , Marcadores Genéticos , Manihot/genética , División Celular/genética , Mapeo Cromosómico , Genotipo , Cariotipificación , Manihot/citología
6.
Genet Mol Res ; 14(4): 16491-6, 2015 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-26662448

RESUMEN

The aim of this study was to characterize variations in Raf kinase inhibitor protein (RKIP) expression and related signaling molecules in gastric cardia adenocarcinoma. Cancerous and precancerous tissues were collected from patients with gastric cardia adenocarcinoma and normal tissue was collected from healthy controls. RKIP expression was detected in these tissues and the serum levels of NF-κB p65 and T-lymphocyte subsets were measured. Positive RKIP expression was higher in gastric cardia adenocarcinoma tissues than in precancerous tissues. The serum level of total NF-κB p65 was higher in patients with gastric cardia adenocarcinoma than in healthy controls. Levels of NF-κB p65 did not correlate with positive and negative expression of RKIP, but were higher in patients with lymph node metastasis than in those without it. The cellular immune function of the gastric cardia adenocarcinoma group was lower than in normal controls, particularly in cases with negative RKIP expression. RKIP is downregulated in gastric cardia adenocarcinoma tissues, which is related to the occurrence, progression, invasion, and metastasis of tumors. The possible mechanism for this may be the inhibition of NF-κB activity and cellular immune function, which allows for the escape of tumor cells from immune surveillance.


Asunto(s)
Adenocarcinoma/inmunología , Adenocarcinoma/metabolismo , Proteínas de Unión a Fosfatidiletanolamina/metabolismo , Neoplasias Gástricas/inmunología , Neoplasias Gástricas/metabolismo , Subgrupos de Linfocitos T/inmunología , Factor de Transcripción ReIA/metabolismo , Adenocarcinoma/sangre , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Progresión de la Enfermedad , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Inmunofenotipificación , Metástasis Linfática , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Fenotipo , Proteínas de Unión a Fosfatidiletanolamina/genética , Neoplasias Gástricas/sangre , Neoplasias Gástricas/patología , Subgrupos de Linfocitos T/metabolismo , Factor de Transcripción ReIA/sangre
9.
Eur Rev Med Pharmacol Sci ; 16(3): 299-304, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22530344

RESUMEN

OBJECTIVES: In this study, we investigated the effect of grape seed proanthocyanidins extracts (GSPE), which have been proved to have anti-oxidative and anti-aging functions, on the expression of apoA-L at mRNA level of HepG2 cells in vitro under the experimental conditions of high-sugar and sugar. MATERIALS AND METHODS: Cell viability was measured by sulforhodamine B (SRB). The apoA-I mRNA expression was assayed by real-time fluorescence quantitative polymerase chain reaction. Firstly, HepG2 cells were incubated in 10% inactivated newborn calf serum in Dulbecco's Modified Eagle Medium (DMEM). Next, cells were incubated with high-sugar and sugar serum-free medium, and added different concentration of GSPE (2.5, 5 and 10 microg/ml) for more than 24 hours, and thereafter, investigated whether GSPE can promote more apoA-I expression in HepG2 cells under the experimental conditions of high-sugar and sugar. RESULTS: In this experiment, HepG2 cells were incubated with high-sugar and sugar serum-free medium, and HepG2 cells incubated with high-sugar medium produced less apoA-I at mRNA level. The difference was significant (p < 0.05). When HepG2 cells were incubated with GSPE at concentration of 20 microg/ml or above for about 4 hours, cell viability measured by SRB was lower than 50%. However, cell viability of HepG2 cells incubated with GSPE at concentration of 10 microg/ml or below was higher than 70%. Therefore, we chose the HepG2 cells incubated with GSPE concentration of 2.5, 5, 10 microg/ml to observe the effect of GSPE on the mRNA expression of apoA-I. After incubated with GSPE, the apoA-I expression of HepG2 cells were significantly elevated at mRNA level compared to that of high sugar control (p < 0.05). Moreover, this action of GSPE showed dose dependent, and the dose of 2.5 microg/ml was optimal. CONCLUSIONS: GSPE (concentration of higher than 20 microg/ml) could inhibit HepG2 cell survival, and in HepG2 cells, endogenous apoA-I was significantly suppressed following 24h of exposure to high concentrations of glucose. Meanwhile GSPE could promote expression of apoA-L dose dependently at mRNA level when its concentration was lower than 10 microg/ml.


Asunto(s)
Apolipoproteína A-I/biosíntesis , Carbohidratos/farmacología , Proantocianidinas/farmacología , Vitis/química , Actinas/biosíntesis , Actinas/genética , Apolipoproteína A-I/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Electroforesis en Gel de Agar , Expresión Génica/efectos de los fármacos , Células Hep G2 , Humanos , Extractos Vegetales/farmacología , Proantocianidinas/química , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Semillas/química
11.
Genet Mol Res ; 9(3): 1896-907, 2010 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-20882485

RESUMEN

We examined the effect of polymorphisms in the endothelial nitric oxide synthase gene on the risk for essential hypertension in a Han Chinese population through a meta-analysis of data from 15 studies. Associations between increased risk for essential hypertension and 4b/a were obtained in a dominant model and allele contrast (aa + ab vs bb: odds ratio (OR)(FE) = 1.26, 95% confidence interval (CI) = 1.10-1.44; a vs b allele: OR(FE) = 1.23, 95%CI: 1.09-1.40). Four studies with sample sizes over 500 produced similar results. No evidence of publication bias was found. Also, no significant heterogeneity was observed among these studies. When we examined the G894T polymorphism, we found a marginally significant association for allele contrast and the recessive model when all the eligible studies were pooled together. However, there was no evidence for a significant association after the exclusion of two studies deviating from Hardy-Weinberg equilibrium in the control group. Heterogeneity among studies was observed. Results of cumulative and recursive cumulative meta-analysis indicated that more studies are needed to objectively determine the effects of these two polymorphisms.


Asunto(s)
Hipertensión/genética , Óxido Nítrico Sintasa de Tipo III/genética , Polimorfismo Genético/genética , Adulto , Anciano , Pueblo Asiatico/genética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad
12.
J Int Med Res ; 37(5): 1443-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19930849

RESUMEN

This study investigated the value of arterial elasticity measurement in the early diagnosis of angiographic coronary artery atherosclerosis in 105 consecutive elderly patients. They were divided into two groups according to the results of selective coronary angiography: 55 with coronary atherosclerosis and 50 with a normal coronary angiogram. The Gensini score of the coronary artery was acquired and capacitive arterial compliance (C1) and oscillatory arterial compliance (C2) were measured. An independent-sample t-test was used to evaluate the difference in C1 and C2 between the two groups. Bivariate analyses were performed to study the association between the Gensini score and C1 and C2. A significant difference between the two groups in C2 was found and the Gensini score of the coronary artery was significantly correlated with C2. Identification of early coronary atherosclerosis in geriatrics may be aided by the prognostic value of C2.


Asunto(s)
Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/patología , Resistencia Vascular/fisiología , Anciano , Enfermedad de la Arteria Coronaria/sangre , Elasticidad , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo
13.
Eur Rev Med Pharmacol Sci ; 23(12): 5422-5431, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31298395

RESUMEN

OBJECTIVE: Atrial fibrillation (AF) is independently associated with a higher risk of acute myocardial infarction (AMI). The occurrence of AMI in AF patients may lead to dismal prognosis. Risk assessment is a fundamental component of prevention for AMI. PATIENTS AND METHODS: 2419 consecutive patients with nonvalvular AF were enrolled in this retrospective study. A logistic regression analysis was performed on clinical variables to create a simple clinical prediction rule. The following nine variables and assigned scores (in brackets) were included in the prediction rule: age ≥65 years (1.0), heart failure (1.0), hypertension (1.0), diabetes mellitus (1.0), hyperlipidemia (0.5), history of stroke/TIA (0.5), vascular disease (1.0), current smoking (0.5), and resting heart rate >90 beats/min (1.0). Patients were considered to have a low probability if the score was ≤2.5, moderate if the score was 3.0 to 4.0, and high if the score was ≥4.5. The AMI unlikely was assigned to patients with scores <3.5 and AMI likely if the score was ≥3.5. To evaluate the score, we included an external validation cohort of 1810 nonvalvular AF patients from the Cardiology Center, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China. RESULTS: The score showed a good ability in discriminating AF patients experiencing AMI both in the internal derivation cohort, with a c-index of 0.80 [95% Confidence Interval (CI) 0.77-0.83, p<0.001] and in the external validation cohort (c-index 0.73, 95% CI 0.69-0.77, p<0.001). Our scoring system offered significantly better predictive performance than the CHA2DS2-VASc score (c-index 0.80 vs 0.71, p<0.001). CONCLUSIONS: Our scoring system is a simple and accurate way of predicting the risk of AMI in AF patients. Therefore, more accurate targeting of preventive therapy will be allowed.


Asunto(s)
Fibrilación Atrial/complicaciones , Modelos Estadísticos , Infarto del Miocardio/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , China/epidemiología , Comorbilidad , Diabetes Mellitus/epidemiología , Femenino , Insuficiencia Cardíaca/epidemiología , Humanos , Hiperlipidemias/epidemiología , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Probabilidad , Estudios Retrospectivos , Medición de Riesgo/métodos , Factores de Riesgo , Fumar/epidemiología , Accidente Cerebrovascular/epidemiología
14.
J Mol Biol ; 277(3): 559-72, 1998 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-9533880

RESUMEN

Based on structural analyses and on the behavior of mutants, we suggest that the polymerase domain of HIV-1 reverse transcriptase (RT) plays a critical role in holding and appropriately positioning the template-primer both at the polymerase active site and at the RNase H active site. For RT to successfully copy the viral RNA genome, RNase H must cleave the RNA with absolute precision. We believe that a combination of the structure of the template-primer and its precise positioning are responsible for the specific cleavages RNase H makes. We have proposed that resistance of HIV-1 RT to nucleoside analogs involves a subtle repositioning of the template-primer. This hypothesis is based on both structural and biochemical analyses. Mutations that confer resistance to nucleoside analogs do not cluster at the polymerase active site; however, they are in positions where they could alter the interaction between RT and the template-primer. If, as we have hypothesized, the polymerase domain is primarily responsible for positioning the template-primer and RNase H cleavage depends on this positioning, it should be possible to use RNase H cleavage to monitor at least some of the major changes in the position of the template-primer. We have used three assays (polymerase, RNase H, and strand transfer) to investigate the effects of mutations in the polymerase domain, including mutations that confer resistance to nucleotide analogs, on HIV-1 RT. All three assays involve RNA sequences derived from the viral genome. The data show that alterations in the polymerase domain, in particular, mutations that are in positions that would be expected to alter the interaction of RT with the template-primer, can alter both the efficiency and specificity of RNase H cleavage. These results are discussed in light of the structure of HIV-1 RT.


Asunto(s)
Transcriptasa Inversa del VIH/metabolismo , VIH-1/enzimología , Mutagénesis , ARN/metabolismo , Ribonucleasa H/metabolismo , Secuencia de Bases , Sitios de Unión , Transcriptasa Inversa del VIH/química , Transcriptasa Inversa del VIH/genética , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Relación Estructura-Actividad
15.
J Mol Biol ; 294(5): 1097-113, 1999 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-10600369

RESUMEN

Retroviral revXerse transcriptases (RTs) have an associated RNase H activity that can cleave RNA-DNA duplexes with considerable precision. We believe that the structure of the RNA-DNA duplexes in the context of RT determines the specificity of RNase H cleavage. To test this idea, we treated three related groups of synthetic RNA-DNA hybrids with either Moloney murine leukemia virus (MLV) RT or human immunodeficiency virus type 1 (HIV-1) RT. All of the hybrids were prepared using the same 81-base RNA template. The first series of RNase H substrates was prepared with complementary DNA oligonucleotides of different lengths, ranging from 6 to 20 nucleotides, all of which shared a common 5' end and were successively shorter at their 3' ends. The second series of oligonucleotides had a common 3' end but shorter 5' ends. The DNA oligonucleotides in the third series were all 20 bases long but had non-complementary stretches at either the 5' end, 3' end, or both ends. Several themes have emerged from the experiments with these RNA-DNA duplexes. (1) Both HIV-1 RT and MLV RT cleave fairly efficiently if the duplex region is at least eight bases long, but not if it is shorter. (2) Although, under the conditions we have used, both enzymes require the substrate to have a region of RNA-DNA duplex, both MLV RT and HIV-1 RT can cleave RNA outside the region that is part of the RNA-DNA duplex. (3) The polymerase domain of HIV-1 RT uses certain mismatched segments of RNA-DNA to position the enzyme for RNase H cleavage, whereas the polymerase domain of MLV RT does not use the same mismatched segments to define the position for RNase H cleavage. (4) For HIV-1 RT, a mismatched region near the RNase H domain can interfere with RNase H cleavage; cleavage is usually (but not always) more efficient if the mismatched segment is deleted. These results are discussed in regard to the structure of HIV-1 RT and the differences between HIV-1 RT and MLV RT.


Asunto(s)
Transcriptasa Inversa del VIH/metabolismo , Virus de la Leucemia Murina de Moloney/enzimología , ADN Polimerasa Dirigida por ARN/metabolismo , Ribonucleasa H/metabolismo , Secuencia de Aminoácidos , Disparidad de Par Base/genética , Secuencia de Bases , Modelos Moleculares , Datos de Secuencia Molecular , Peso Molecular , Conformación de Ácido Nucleico , Ácidos Nucleicos Heterodúplex/química , Ácidos Nucleicos Heterodúplex/genética , Ácidos Nucleicos Heterodúplex/metabolismo , Oligodesoxirribonucleótidos/química , Oligodesoxirribonucleótidos/genética , Oligodesoxirribonucleótidos/metabolismo , ARN/química , ARN/genética , ARN/metabolismo , Alineación de Secuencia , Relación Estructura-Actividad , Especificidad por Sustrato , Temperatura , Moldes Genéticos
16.
J Mol Biol ; 300(2): 403-18, 2000 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-10873473

RESUMEN

Treating HIV infections with drugs that block viral replication selects for drug-resistant strains of the virus. Particular inhibitors select characteristic resistance mutations. In the case of the nucleoside analogs 3TC and FTC, resistant viruses are selected with mutations at amino acid residue 184 of reverse transcriptase (RT). The initial change is usually to M184I; this virus is rapidly replaced by a variant carrying the mutation M184V. 3TC and FTC are taken up by cells and converted into 3TCTP and FTCTP. The triphosphate forms of these nucleoside analogs are incorporated into DNA by HIV-1 RT and act as chain terminators. Both of the mutations, M184I and M184V, provide very high levels of resistance in vivo; purified HIV-1 RT carrying M184V and M184I also shows resistance to 3TCTP and FTCTP in in vitro polymerase assays. Amino acid M184 is part of the dNTP binding site of HIV-1 RT. Structural studies suggest that the mechanism of resistance of HIV-1 RTs carrying the M184V or M184I mutation involves steric hindrance, which could either completely block the binding of 3TCTP and FTCTP or allow binding of these nucleoside triphosphate molecules but only in a configuration that would prevent incorporation. The available kinetic data are ambiguous: one group has reported that the primary effect of the mutations is at the level of 3TCTP binding; another, at the level of incorporation. We have approached this problem using assays that monitor the ability of HIV-1 RT to undergo a conformational change upon binding a dNTP. These studies show that both wild-type RT and the drug-resistant variants can bind 3TCTP at the polymerase active site; however, the binding to M184V and M184I is somewhat weaker and is sensitive to salt. We propose that the drug-resistant variants bind 3TCTP in a strained configuration that is salt-sensitive and is not catalytically competent.


Asunto(s)
Transcriptasa Inversa del VIH/antagonistas & inhibidores , Transcriptasa Inversa del VIH/química , VIH-1/enzimología , Lamivudine/metabolismo , Lamivudine/farmacología , Sustitución de Aminoácidos/genética , Fármacos Anti-VIH/metabolismo , Fármacos Anti-VIH/farmacología , Sitios de Unión , Catálisis , Nucleótidos de Desoxicitosina/metabolismo , Nucleótidos de Desoxicitosina/farmacología , Desoxirribonucleótidos/metabolismo , Farmacorresistencia Microbiana/genética , Transcriptasa Inversa del VIH/genética , Transcriptasa Inversa del VIH/metabolismo , Modelos Moleculares , Mutación/genética , Ensayos de Protección de Nucleasas , Oligodesoxirribonucleótidos/genética , Oligodesoxirribonucleótidos/metabolismo , Unión Proteica/efectos de los fármacos , Conformación Proteica , ARN/biosíntesis , ARN/química , ARN/genética , ARN/metabolismo , Proteínas de Unión al ARN/antagonistas & inhibidores , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Inhibidores de la Transcriptasa Inversa/metabolismo , Inhibidores de la Transcriptasa Inversa/farmacología , Ribonucleasa H/metabolismo , Sales (Química)/farmacología , Electricidad Estática , Moldes Genéticos , Transcripción Genética
17.
Virus Res ; 45(2): 101-9, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8896245

RESUMEN

The RNA polymerase gene of murine coronavirus MHV-JHM encodes a polyprotein of greater than 750 kDa. This polyprotein is proposed to be processed by two papain-like cysteine proteinases, PCP-1 and PCP-2, and a poliovirus 3C-like proteinase domain, 3C-pro, to generate protein products. The amino-terminal product of the MHV polymerase polyprotein, p28, is generated by cleavage of the polyprotein by PCP-1. To identify the viral products downstream of p28, we generated a fusion-protein specific antiserum directed against the region adjacent to p28 and used the antiserum to detect virus-specific proteins from MHV-JHM infected cells. When this antiserum was used to immunoprecipitate radiolabeled proteins from MHV-JHM infected cell lysates, virus-specific proteins of 72 and 65 kDa were detected. Furthermore, pulse and chase experiments demonstrated that p72 is likely a precursor to the mature protein product, p65. To investigate which viral proteinase may be responsible for generating p72 and p65, we expressed the 5'-region of the MHV-JHM RNA polymerase gene including the two papain-like cysteine proteinase domains in an in vitro transcription/translation system and analyzed the translation products for proteolytic processing. We also cloned and expressed the 72 kDa region immediately downstream from p28, and tested the ability of in vitro translated PCP-1 and PCP-2 to cleave p72 to p65 in trans. Our results indicate that neither viral proteinase domain PCP-1 nor PCP-2 is capable of cleavage of p72 to produce p65 in vitro. The role of MHV proteinases in the processing of p72 and p65 is discussed.


Asunto(s)
Virus de la Hepatitis Murina/enzimología , Procesamiento Proteico-Postraduccional , ARN Polimerasa Dependiente del ARN/metabolismo , Proteínas Virales/metabolismo , Animales , Ratones , Virus de la Hepatitis Murina/genética , Proteínas/genética , Proteínas/metabolismo , ARN Polimerasa Dependiente del ARN/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Virales/genética
18.
J Atheroscler Thromb ; 8(1): 30-2, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11686313

RESUMEN

Increasing evidence has indicated the important roles of inflammation and immune response in the development of atherosclerosis and ischemic heart disease (IHD). We measured the serum interleukin (IL)-8 and IL-12 levels of patients with unstable angina pectoris (UAP) and patients with acute myocardial infarction (AMI), and compared findings with those of normal subjects. The results showed that the serum level of IL-8 was significantly higher in patients with UAP and patients with AMI than in healthy control subjects. To our knowledge, this is the first report that serum IL-12 level was elevated in patients with AMI but not in patients with UAP. These findings suggest that IL-8 and IL-12 are involved in the process of IHD, and serum IL-12 may be a marker for differentiating AMI from UAP.


Asunto(s)
Interleucina-12/sangre , Interleucina-8/sangre , Isquemia Miocárdica/sangre , Anciano , Angina de Pecho/sangre , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia
19.
Adv Exp Med Biol ; 380: 431-5, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8830520

RESUMEN

The polymerase gene of Mouse Hepatitis Virus strain JHM (MHV-JHM) encodes a polyprotein larger than 750 kilodaltons. This polyprotein is proposed to be processed by several viral proteinases into functional subunits. The amino-terminal subunit is p28, which is cleaved by the first viral papain-like proteinase domain. In this study, we identified the cleavage site of this papain-like cysteine proteinase by amino acid sequencing of radiolabeled polypeptide adjacent to p28. Proteolysis occurs between the glycine-247 and valine-248 dipeptide bond. To determine which amino acid residues are critical for proteolysis, we preformed site-directed mutagenesis on the coding sequences surrounding the cleavage site and assayed for the efficiency of cleavage of p28 in an in vitro transcription and translation system. We report that glycine-247 and arginine-246 are the most critical residues for efficient processing of p28.


Asunto(s)
Cisteína Endopeptidasas/metabolismo , Virus de la Hepatitis Murina/enzimología , Procesamiento Proteico-Postraduccional , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Animales , Arginina , Sitios de Unión , Glicina , Cinética , Ratones , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Papaína , Biosíntesis de Proteínas , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato , Transcripción Genética , Proteínas Virales/biosíntesis , Proteínas Virales/química
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