Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Bull Exp Biol Med ; 170(3): 340-344, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33452981

RESUMEN

We evaluated the possibility of using an experimental model of hepatocellular carcinoma to study oncomarkers of primary liver cancer and compared the diagnostic efficacy of alpha-fetoprotein and osteopontin in the experiment and in clinical practice. Experimental studies were performed on a model of hepatocellular carcinoma induced by administration of diethyl nitrosamine to Fisher-344 rats. In addition, the levels of α-fetoprotein and osteopontin were determined in 35 patients with hepatocellular carcinoma detected at stages I-II according to TNM classification. The proposed model of liver cancer in rats reflects the sequence of stages characteristic of hepatocellular carcinoma in humans: liver fibrosis-cirrhosis-cancer. This model is applicable for the study of tumor markers at the early stage of tumor development. Osteopontin was found to have a more powerful diagnostic potential then alpha-fetoprotein.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Osteopontina/metabolismo , alfa-Fetoproteínas/metabolismo , Animales , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma Hepatocelular/genética , Cirrosis Hepática/genética , Cirrosis Hepática/metabolismo , Neoplasias Hepáticas/genética , Osteopontina/genética , Ratas , alfa-Fetoproteínas/genética
2.
Klin Lab Diagn ; 64(10): 607-612, 2019.
Artículo en Ruso | MEDLINE | ID: mdl-31742954

RESUMEN

Liver cirrhosis in the outcome of hepatitis C is the leading cause of hepatocellular carcinoma (HCC) in the world. Early diagnosis and timely treatment of HCC are important for reducing mortality and increasing life expectancy of patients with hepatocellular carcinoma. To assess the risk of HCC, the definition of alpha-fetoprotein (AFP) in the blood is most widely used, but low sensitivity limits its diagnostic value. In 2012, a new HCC biomarker - osteopontin (OPN), which is a secreted phosphoprotein that has a high affinity for integrins was proposed. The level of acute renal failure begins to rise in the early stages of malignancy, before the period of HCC detection by imaging methods, and has significantly better sensitivity than AFP. The purpose of this study is to evaluate the diagnostic efficacy of the combined determination of alpha-fetoprotein and osteopontin in prospective monitoring of patients with chronic hepatitis C in the advanced phase of liver fibrosis. Monitoring of 588 patients with hepatitis C was carried out from February 2013 to February 2019. HCC was detected in 55 of them (2.6% per year). The combination of 2 biomarkers showed better diagnostic efficacy than alpha-fetoprotein and osteopontin separately: AUC 0.85 (95% CI 0.80-0.90) versus AUC 0.63 (95% CI 0.57-0, 70) and AUC 0.82 (95% CI 0.77-0.88), respectively. This combination showed a sensitivity of 85.5% and made it possible to diagnose HCC with a prognostic level of a positive result of 72.3% at 19,4±0,8 weeks before the diagnosis was confirmed by instrumental imaging methods (ultrasound, MRI, CT). In the combined variant, ARF made the greatest contribution to the increase in diagnostic efficacy (AUC). At an early and very early stage of HCC development, isolated HCC elevations were found in only 5.4% of patients. Conclusion: the combined use of alphafetoprotein and osteopontin as a diagnostic panel can be recommended for monitoring patients with liver cirrhosis in the outcome of hepatitis C and predicting HCC at an early stage of development.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Hepatitis C/diagnóstico , Neoplasias Hepáticas/diagnóstico , Osteopontina/sangre , alfa-Fetoproteínas/análisis , Biomarcadores de Tumor/sangre , Detección Precoz del Cáncer , Humanos , Fragmentos de Péptidos , Estudios Prospectivos
3.
Mol Phylogenet Evol ; 124: 60-70, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29501375

RESUMEN

Pontoscolex corethrurus is the most widespread earthworm species in tropical and sub-tropical zones and one of the most studied in soil science. Although, ecological interactions of P. corethrurus with its environment are well documented, the taxonomic status of the species remains unclear. In this study, we investigated phylogenetic relationships within the genus Pontoscolex, in particular focusing on morphologically indistinguishable (i.e., cryptic) lineages. A total of 792 specimens collected from 25 different countries and islands all over the world were analyzed using two mitochondrial (COI and 16S rDNA) and two nuclear (internal transcribed spacers 2 and 28S rDNA) markers, and a total of 11 morphological characters both internal and external were investigated in all genetically characterized lineages. A large-scale multilocus sequence data matrix was also obtained for Pontoscolex spp. specimens using the Anchored Hybrid Enrichment (AHE) method. Multilocus phylogenetic and phylogenomic analyses, combined with species delimitation methods; including single locus (mPTP, ABGD) and multilocus (BPP) approaches, revealed congruent results. Four cryptic species were supported within the P. corethrurus species complex, and four potentially new species within the genus Pontoscolex. One widespread lineage (L1), within P. corethrurus complex was observed in the current population of Fritz Müller's garden where P. corethrurus was first described in 1856. Cryptic lineages were observed in sympatry at several localities. This, in combination with observed heteroplasmy in COI gene in one population raises an important question of reproductive isolation between these species.


Asunto(s)
Oligoquetos/clasificación , Animales , Teorema de Bayes , Marcadores Genéticos , Geografía , Haplotipos/genética , Oligoquetos/anatomía & histología , Filogenia , Especificidad de la Especie , Simpatría
4.
Sovrem Tekhnologii Med ; 13(1): 27-33, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34513063

RESUMEN

The aim of the study was to identify the most effective serum tumor markers for early diagnosis of hepatocellular carcinoma based on the combination of diagnostic characteristics and correlations. Materials and Methods: There were observed 55 patients with chronic hepatitis C in the stage of liver cirrhosis with a verified diagnosis of hepatocellular carcinoma. The control group consisted of 55 patients with chronic hepatitis C at the stage of liver cirrhosis without hepatocellular carcinoma, comparable to the experimental group in terms of basic clinical profile. The following tumor markers were estimated in both groups: alpha-fetoprotein (AFP), alpha-fetoprotein-L3 (AFP-L3), annexin A2 (ANXA2), heparin-binding growth factor Midkine (MDK), glypican-3 (GPC3), des-gamma-carboxyprothrombin (DCP, PIVKA-II), dickkopf-related protein 1 (DKK-1), osteopontin (OPN), and Golgi protein 73 (GP73). There were also evaluated such indices as diagnostic sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio of a positive test, the possible correlation between alpha-fetoprotein and other tumor markers. The area under the ROC curve (AUC) was calculated at the 95% confidence interval. Results: The greatest sensitivity was revealed when using heparin-binding growth factor, annexin A2, osteopontin. Alpha-fetoprotein, alpha-fetoprotein-L3, glypican-3, des-gamma-carboxyprothrombin, dickkopf-related protein 1 had the best specificity. AUC>0.75 was found in annexin A2, heparin-binding growth factor, glypican-3, des-gamma-carboxyprothrombin, osteopontin, Golgi protein 73. The likelihood ratio of a positive test result was the highest for glypican-3. A significant correlation was found between alpha-fetoprotein and alpha-fetoprotein-L3, annexin A2, des-gamma-carboxyprothrombin. Conclusion: According to the aggregate indicators of diagnostic efficiency, heparin-binding growth factor, glypican-3, and osteopontin are the most promising tumor markers of those studied. When they are used, integral AUC values are above the average, the level of these tumor markers in the blood of patients with hepatocellular cancer does not correlate with alpha-fetoprotein. They are applicable for diagnosing liver cancer in AFP-negative patients. The combined use of AFP + GPC3, AFP + OPN has already shown their advantages. However, the efficacy of the combination of AFP + MDK, GPC3 + OPN has not been determined yet; therefore, significance of the combined use of these tumor markers in the diagnosis of liver cancer should be investigated in the near future.


Asunto(s)
Carcinoma Hepatocelular , Hepatitis C , Neoplasias Hepáticas , Biomarcadores de Tumor , Carcinoma Hepatocelular/diagnóstico , Detección Precoz del Cáncer , Glipicanos , Humanos , Neoplasias Hepáticas/diagnóstico
5.
Gastroenterol Clin Biol ; 33 Suppl 4: S257-62, 2009 Nov.
Artículo en Francés | MEDLINE | ID: mdl-20004332

RESUMEN

Liver transplantation is considered the best treatment of hepatocellular carcinoma but its efficacy depends on the risk of tumour recurrence. The risk of recurrence depends on tumour characteristics but is also influenced by immunosuppressive regimens. Immunosuppressants of the mTOR inhibitors family share anti-tumour properties which are already taken into account in the treatment of renal carcinoma and advanced hepatocellular carcinoma. These features make interesting their use in liver transplantation for hepatocellular carcinoma, with the following goals: to reduce the risk of post-transplant tumour recurrence, to expand the indications of liver transplantation for hepatocellular carcinoma and eventually to slow down tumour growth during the waiting period. However, to date, the potential role of mTOR inhibitors after liver transplantation for hepatocellular carcinoma is only based on small encouraging proof of concept studies. Large randomized studies are therefore required to further define the specific indications of these compounds. The demonstration of a beneficial impact of mTOR inhibitors in the setting of liver transplantation for hepatocellular carcinoma would be a major therapeutical advance.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Inmunosupresores/administración & dosificación , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Neoplasias Hepáticas/cirugía , Trasplante de Hígado/métodos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Animales , Antineoplásicos/administración & dosificación , Humanos , Recurrencia Local de Neoplasia/prevención & control , Sirolimus/administración & dosificación , Serina-Treonina Quinasas TOR
6.
Gastroenterol Clin Biol ; 33(5): 361-9, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19398289

RESUMEN

While the natural history and appropriate diagnostic and management practices are relatively well defined for hepatocellular carcinoma (HCC), data are scarce concerning the characteristic features and treatment modalities for recurrent HCC after liver transplantation. The time of recurrence appears to impact survival more significantly than localization, but to date, guidelines for therapeutic management of recurrent HCC have not been established. Data in the literature shows that late and unifocal recurrence has a better prognosis when treated by surgery or radiofrequency. In the event of early recurrence, surgery cannot be recommended due to the lack of evidence and the high risk of advanced disease. Systemic therapy can be discussed in a situation of multifocal recurrence. Proliferative signal inhibitors exhibit both immunosuppressive and antiproliferative properties and liver transplantation teams tend to introduce such treatment despite the lack of extensive data.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Algoritmos , Humanos , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/terapia , Factores de Riesgo
7.
Neotrop Entomol ; 44(2): 109-15, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26013127

RESUMEN

Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity.


Asunto(s)
Vuelo Animal , Mariposas Nocturnas/fisiología , Animales , Guyana Francesa , Factores de Tiempo
9.
Diagn Interv Imaging ; 94(7-8): 677-95, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23830777

RESUMEN

Management of patients with a benign hepatocellular tumor relies largely on imaging data; the diagnosis of focal nodular hyperplasia (FNH) must be made with certainty using MRI, because no other clinical or laboratory data can help diagnosis. It is also essential to identify adenomas to manage them appropriately. The radiological report in these situations is therefore of major importance. However, there are diagnostic traps. The aim of this paper is to present the keys to the diagnosis of benign lesions and to warn of the main diagnostic pitfalls.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Diagnóstico por Imagen , Hepatopatías/diagnóstico , Neoplasias Hepáticas/diagnóstico , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
10.
J Radiol ; 92(7-8): 688-700, 2011.
Artículo en Francés | MEDLINE | ID: mdl-21819911

RESUMEN

PURPOSE: To validate the 2010 diagnostic criteria from the American Association for the Study of Liver Diseases (AASLD) for hepatocellular carcinoma (HCC) on MRI using the surgical liver specimen as a gold standard. PATIENTS AND METHODS: A total of 21 liver transplant recipients were retrospectively included. Each underwent surgery because of HCC between January 2007 and January 2008. Pre-transplant MRI was performed on a 1.5 Tesla MR unit. The T1W and T2W signal and kinetic contrast enhancement were correlated for each lesion with the surgical specimen. Lesion diameters between MRI and specimen were compared (Spearman). A multivariate model was created (R statistics software package) to predict the presence and grade of tumor differentiation (WHO, Edmonson Steiner). RESULTS: A total of 71 nodules were detected at histology, including 54 HCC (mean size: 25.3mm) compared to 68 on MRI. There was moderate agreement (r=0.58, P<0.001) between the maximum lesion diameters measured on MRI and at histology. Wash-out on MRI provided an accuracy of 75 % for the detection of HCC (sensitivity=75 %, specificity=76 %). Adding T2W hyperintensity to the AASLD criteria increased the sensitivity of MRI from 70.3 % to 77.7 % for the diagnosis of HCC and from 67.6 % to 79 % for nodules less than 20mm in diameter, without affecting specificity. On multivariate analysis, wash out as a single variable was significantly associated with a diagnosis of HCC (P<0.01, odds ratio 12.0, CI 95 % [2.6-55.5]). T1W hyperintensity (P=0.04, odds ratio 5.4) and loss of signal on opposed-phase images (P=0.02, odds ratio 9.2) were predictive of good differentiation. CONCLUSION: On MRI, the AASLD criteria or presence of wash out within a liver nodule in patients with underlying chronic hepatocellular disease are suggestive of tumoral transformation. The addition of T2W hyperintensity to the AASLD criteria increases the detection of HCC, especially nodules smaller than 20mm.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patología , Aumento de la Imagen , Procesamiento de Imagen Asistido por Computador , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patología , Trasplante de Hígado , Imagen por Resonancia Magnética , Anciano , Algoritmos , Carcinoma Hepatocelular/cirugía , Transformación Celular Neoplásica/patología , Medios de Contraste/administración & dosificación , Femenino , Francia , Humanos , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Sensibilidad y Especificidad , Sociedades Médicas , Estadística como Asunto , Carga Tumoral
11.
Mol Ecol Resour ; 10(4): 606-14, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21565065

RESUMEN

Species identification of earthworms is usually achieved by careful observation of morphological features, often sexual characters only present in adult specimens. Consequently, juveniles or cocoons are often impossible to identify, creating a possible bias in studies that aim to document species richness and abundance. DNA barcoding, the use of a short standardized DNA fragment for species identification, is a promising approach for species discrimination. When a reference library is available, DNA-based identification is possible for all life stages. In this study, we show that DNA barcoding is an unrivaled tool for high volume identification of juvenile earthworms. To illustrate this advance, we generated DNA barcodes for specimens of Lumbricus collected from three temperate grasslands in western France. The analysis of genetic distances between individuals shows that juvenile sequences unequivocally match DNA barcode clusters of previously identified adult specimens, demonstrating the potential of DNA barcoding to provide exhaustive specimen identification for soil ecological research.

12.
C R Acad Sci III ; 324(8): 733-42, 2001 Aug.
Artículo en Francés | MEDLINE | ID: mdl-11510419

RESUMEN

An ecological classification based on a set of morphological characters may be used to describe earthworm functions in soil. However these relationships have been seldom verified. Gizzards of the earthworm Martiodrilus carimaguensis (Glossoscolecidae) were studied to find out if its anecic morphology was in agreement with its diet (shallow litter remains and deep organo-mineral material). By direct observation of 13 adults' gizzard contents with a dissecting and a phase contrast microscope, the volumetric percentage of plant fragments, roots, amorphous organic matter and mineral particles reached respectively 63, 5, 6.5 and 30% v/v. Eighty percent of plant fragments were microscopic, and mostly incorporated into the organo-mineral earthworm casts well preserved in the gizzard. Coprophagy and rhizophagy were the dominant feature of M. carimaguensis diet. Yet, the casts produced revealed a high variability in its diet, what could be related to transitional adoption of a typical anecic diet during some periods.


Asunto(s)
Dieta , Ecosistema , Oligoquetos/clasificación , Oligoquetos/fisiología , Animales , Colombia , Oligoquetos/anatomía & histología , Suelo
13.
C R Acad Sci III ; 324(5): 465-78, 2001 May.
Artículo en Francés | MEDLINE | ID: mdl-11411289

RESUMEN

Fourteen types of physical structures produced by ecosystem engineers were sampled at the surface of a savanna soil of Colombia. Invertebrates implicated in the creation of these structures were identified. Some physical (aggregate size and stability, bulk density) and chemical (C, N, P contents, pH, etc) properties of structures were assessed. Three large groups of structures were identified: (i) earthworm casts characterised by a high bulk density (1.3-1.4 g.cm-3), constituted of aggregates (7-10 mm), high in organic C (3-4%) and assimilable nutrients; (ii) termite mounds with low bulk density (0.6-0.9 g.cm-3), constituted of aggregates (8-9 mm), high in organic C (3.5-10%) and assimilable nutrients; and (iii) slightly compact (0.4-0.7 g.cm-3) and granular (aggregate size < 1.5 mm) termite superficial channels and ant mounds low in organic C (less than 1.5%) and assimilable nutrients. These results underline the large diversity of the biogenic structures produced at the surface of the studied soil. They suggest the feasibility of a functional classification of engineer organisms that would take into account simultaneously the different functional attributes reflected by these structures.


Asunto(s)
Ecología , Suelo , Animales , Hormigas , Clima , Colombia , Isópteros , Modelos Biológicos , Oligoquetos
14.
Proc Natl Acad Sci U S A ; 101(49): 17216-21, 2004 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-15563600

RESUMEN

Although inappropriate activation of the Wnt/beta-catenin pathway has been implicated in the development of hepatocellular carcinoma (HCC), the role of this signaling in liver carcinogenesis remains unclear. To investigate this issue, we constructed a mutant mouse strain, Apc(lox/lox), in which exon 14 of the tumor-suppressor gene adenomatous polyposis coli (Apc) is flanked by loxP sequences. i.v. injection of adenovirus encoding Cre recombinase (AdCre) at high multiplicity [10(9) plaque-forming units (pfu) per mouse] inactivated the Apc gene in the liver and resulted in marked hepatomegaly, hepatocyte hyperplasia, and rapid mortality. beta-Catenin signaling activation was demonstrated by nuclear and cytoplasmic accumulation of beta-catenin in the hepatocytes and by the induction of beta-catenin target genes (glutamine synthetase, glutamate transporter 1, ornithine aminotransferase, and leukocyte cell-derived chemotaxin 2) in the liver. To test a long-term oncogenic effect, we inoculated mice with lower doses of AdCre (0.5 x 10(9) pfu per mouse), compatible with both survival and persistence of beta-catenin-activated cells. In these conditions, 67% of mice developed HCC. beta-Catenin signaling was strongly activated in these Apc-inactivated HCCs. The HCCs were well, moderately, or poorly differentiated. Indeed, their histological and molecular features mimicked human HCC. Thus, deletion of Apc in the liver provides a valuable model of human HCC, and, in this model, activation of the Wnt/beta-catenin pathway by invalidation of Apc is required for liver tumorigenesis.


Asunto(s)
Proteínas del Citoesqueleto/fisiología , Genes APC , Neoplasias Hepáticas Experimentales/etiología , Transducción de Señal , Transactivadores/fisiología , Animales , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Vectores Genéticos/administración & dosificación , Inmunohistoquímica , Hígado/metabolismo , Neoplasias Hepáticas Experimentales/genética , Neoplasias Hepáticas Experimentales/patología , Ratones , Ratones Mutantes , Fenotipo , Tasa de Supervivencia , Transcripción Genética , beta Catenina
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA