1,024 research outputs found
Mission d'appui administratif et financier auprès de l'IRAG (Guinée Conakry) du 22 au 26 septembre 2008
Detection of vitellogenin in a subpopulation of sea urchin coelomocytes
Sea urchin vitellogenin is a high molecular weight glycoprotein, which is the precursor of the major yolk protein present in the unfertilized egg. Vitellogenin processing into the major yolk protein and its further enzymatic cleavage during sea urchin embryonic development, has been extensively described, and the adhesive properties of the processed molecule have been studied. The function of vitellogenin in the adult, where it has been found in the coelomic fluid of both male and female individuals, is still unknown, although its role on promoting the adhesion of embryonic cells has been shown. In this report we describe the detection of vitellogenin in lysates of whole circulating coelomocytes of both male and female sea urchins of the species Paracentrotus lividus. By metrizoic acid gradients we purified total coelomocytes into six subpopulations that were tested for the occurrence of the molecule using vitellogenin-specific polyclonal antibodies. We detected vitellogenin only in the coelomocyte subpopulation called colorless spherule cells, packed in kidney-shaped granules located around the nucleus. We also showed that coelomocytes respond to stress conditions by discharging vitellogenin into the medium. This result together with previous observations on the adhesive properties of the molecule suggest a role for vitellogenin in the clotting phenomenon occurring after host invasion
Novel Combination of Sorafenib and Celecoxib Provides Synergistic Anti-Proliferative and Pro-Apoptotic Effects in Human Liver Cancer Cells
Molecular targeted therapy has shown promise as a treatment for advanced hepatocellular carcinoma (HCC). Sorafenib, a multikinase inhibitor, recently received FDA approval for the treatment of advanced HCC. However, although sorafenib is well tolerated, concern for its safety has been expressed. Celecoxib (Celebrex®) is a selective cyclooxygenase-2 (COX-2) inhibitor which exhibits antitumor effects in human HCC cells. The present study examined the interaction between celecoxib and sorafenib in two human liver tumor cell lines HepG2 and Huh7. Our data showed that each inhibitor alone reduced cell growth and the combination of celecoxib with sorafenib synergistically inhibited cell growth and increased apoptosis. To better understand the molecular mechanisms underlying the synergistic antitumor activity of the combination, we investigated the expression profile of the combination-treated liver cancer cell lines using microarray analysis. Combination treatment significantly altered expression levels of 1,986 and 2,483 transcripts in HepG2 and Huh7 cells, respectively. Genes functionally involved in cell death, signal transduction and regulation of transcription were predominantly up-regulated, while genes implicated in metabolism, cell-cycle control and DNA replication and repair were mainly down-regulated upon treatment. However, combination-treated HCC cell lines displayed specificity in the expression and activity of crucial factors involved in hepatocarcinogenesis. The altered expression of some of these genes was confirmed by semi-quantitative and quantitative RT-PCR and by Western blotting. Many novel genes emerged from our transcriptomic analyses, and further functional analyses may determine whether these genes can serve as potential molecular targets for more effective anti-HCC strategies
Hidatidosis ósea: nuestra casuística
Se revisan los resultados de 16 casos de hidatidosis musculoesquelética
tratados en la Unidad de Sépticos del Aparato Locomotor del Hospital Universitario "La Fe" de
Valencia en el período 1972-1989.
Las dificultades diagnósticas fueron importantes, siendo en 5 de los casos un diagnóstico
operatorio. Analizados los métodos de tratamiento se llega a la conclusión de que la curación
definitiva sólo se consigue con la resección completa y amplia de la lesión. Los curetajes,
acompañados o no de aseptizaciones químicas, suelen dar recidivas. Se recomienda combinar
el tratamiento médico con el quirúrgico.The results of 16 cases of musculoskeletal hydatidosis treated in
the locomotive Apparatus Septic Unit of the Valencia University Hospital "La Fe"
between 1972 and 1989 wer e reviewed.
The diagnostic difficulties wer e marked and 5 cases wer e diagnosed at surgery.
After analyzing the therapeutical approaches, it is drawn the conclusion that a
definitive healing is achieved only when an extensive and complete resection is
done. Curettage, with and without chemical aseptization, generally results in recurrence.
A combined medical and surgical treatment is recommended
Non invasive tools for the diagnosis of liver cirrhosis
Liver cirrhosis (LC), the end stage of many forms of chronic hepatitis of different etiologies is a diffuse
process characterized by fibrosis and the conversion of normal liver architecture into structurally abnormal nodules surrounded by annular fibrosis. This chronic
progressive clinical condition, leads to liver cell failure and portal hypertension, which can favour the onset of hepatocellular carcinoma. Defining the phase of the natural history is crucial for therapeutic choice and prognosis. Liver biopsy is currently considered the
best available standard of reference but it has some limits, so alternative tools have been developed to substitute liver biopsy when assessing liver fibrosis.
Serum markers offer a cost-effective alternative to liver biopsy being less invasive and theoretically without
complications. They can be classified into direct and indirect markers which may be used alone or in combination to produce composite scores. Diagnostic
imaging includes a number of instruments and techniques to estimate liver fibrosis and cirrhosis like
ultrasound (US), US Doppler, contrast enhanced US and Elastography. US could be used for the diagnosis of
advanced LC while is not able to evaluate progression of fibrosis, in this case Elastography is more reliable.
This review aims to revise the most recent data from the literature about non invasive methods useful in
defining liver fibrosis
Experiments on crack propagation and threshold at defects in press-fits of railway axles
Fatigue strength under fretting fatigue is one of the open problems in the area of fatigue. In the case of railway wheel-axle press-fits,
there are no records of recent failures because design rules are today based on making the shape of geometrical transitions the most
stressed point. However, it is important to analyze correctly the acceptability of defects and micro-cracks at press-fits.
In this paper, after a preliminary presentation of the results obtained by a new criterion for predicting the non-propagation of
cracks under rolling contact fatigue conditions, a new series of experiments on full-scale axle press-fits containing artificial defects
is presented and discussed. Results show the modified Dang Van criterion is adequate for describing the development of natural
cracks and cracks from artificial defects. The latter, characterized by a depth of 250 350 m, are competitors of fretting cracks
naturally developed from surface scars and surface damage
GRP78 POLYMORPHISM rs430397 IS ASSOCIATED WITH HEPATOCELLULAR CARCINOMA IN A SOUTHERN ITALIAN POPULATION
Heat shock protein 70 serum levels differ significantly in patients with chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma.
Members of the heat shock protein 70 (HSP70) family play an important role in assisting protein folding, preventing protein aggregation and transport of proteins across membranes under physiological conditions. Following environmental (i.e., irradiation, chemotherapy), physiological (i.e., cell growth, differentiation), and pathophysiological (i.e., inflammation, tumorigenesis) stress, the synthesis of heat shock proteins (HSPs) is highly up-regulated, whereas protein synthesis in general is reduced. In contrast to normal cells, many tumor entities including hepatocellular carcinoma (HCC) overexpress HSP70, the major-stress-inducible member of the HSP70 family, present it on their cell surface and secrete it into the extracellular milieu. Herein, the prognostic relevance of serum HSP70 levels in patients with chronic hepatitis (CH; n = 50), liver cirrhosis (LC; n = 46), and HCC (n = 47) was analyzed. Similar to other tumor entities, HSP70 is also present on the surface of primary HCC cells. The staining intensity of intracellular HSP70 in HCC tissue is stronger compared to control and cirrhotic liver sections. HSP70 serum levels in all HCC patients were significantly higher compared to a control group without liver disease (n = 40). No significant age- and gender-related differences in HSP70 serum levels were observed in male and female healthy human volunteers (n = 86). Patients with CH (n = 50) revealed significantly higher HSP70 serum levels compared to the control group, however, these values were significantly lower than those of HCC patients (n = 47). Furthermore, a subgroup of patients with LC who subsequently developed HCC (LC-HCC, n = 13) revealed higher HSP70 serum levels than patients with LC (n = 46, p = 0.05). These data indicate that serum HSP70 levels are consecutively increased in patients with CH, LC and liver carcinomas and thus might have a prognostic value
Therapeutic biomaterials based on extracellular vesicles: classification of bio-engineering and mimetic preparation routes
This work was supported by the Ministerio de Economía y Competitividad (MINECO, Spain), under the Grant CTQ2013-47396-R. This study was also financed by the Consejería de Economía y Empleo del Principado de Asturias (Plan de Ciencia, Tecnología e Innovación 2013-2017), under the Grant GRUPIN14-022. Support from the European Regional Development Fund is gratefully acknowledge
Surface resonant modes in colloidal photonic crystals
Herein we report an experimental and theoretical optical analysis of the effect of growing a dielectric slab on the surface of photonic colloidal crystals. Optical spectroscopy shows an enhancement of the transmitted intensity for certain frequencies within the photonic pseudogap. Simulations based on a scalar wave approximation fairly reproduce the experimental results and provide a description of the interplay between the features arising from the presence of the surface slab and the finite size of the photonic crystal. The experimental observations are explained by the excitation of photon resonant states at the crystal boundary. Our work demonstrates that the amplitude of light waves penetrating the crystal with frequencies lying within the pseudogap range can be greatly modified by rather simple means
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