Variación estacional y sexual en la composición y perfil de ácidos grasos en filetes de caballa, Scomber scombrus (L. 1758) de la costa este tunecina

This study investigates the impact of season and sex variations on the total lipid contents and fatty acid composition of Scomber scombrus fillets from the Middle East Coast of Tunisia in order to dertermine the most favorable periods for consumption, and to see if the nutritional quality of the meat depends on the sex of the animal. The effect of fishing season induced significant changes in the lipid profile, and the highest values for total lipids were obtained in the spring for females with 13.2% and for males with 18.9%. The highest values for proteins were obtained in the summer for females with 22.0% and for males with 21.8%. Protein content variations were not significant (p > 0.05). The n-3/n-6 ratio showed a significant level, indicating a tendency toward n-3 fatty acid accumulation in mackerel fillets mainly represented by DHA, whose values were high during the study period for both sexes, except in autumun, which is the period of mackerel gonad maturation, when DHA decreased significantly (p 0.05). The Atherogenicity index (AI) and Thrombogenicity index (TI) were calculated. In our study the AI index was comprised between 0.3 and 0.6 for males and between 0.4 and 0.5 for females. The TI index values ranged from 0.6 to 0.8 for males, and was about 0.6 for females.Este estudio investiga el impacto de las variaciones estacionales y sexuales sobre el contenido total de lípidos y la composición de ácidos grasos de filetes de caballa, Scomber scombrus, de la Costa Este Tunecina, con objeto de determinar los períodos más favorables para su consumo y para ver si la calidad nutricional de la carne depende del sexo del animal. Los efectos de la temporada de pesca indujeron cambios significativos en el perfil de lípidos, así, los valores más altos de lípidos totales se obtuvieron en primavera para las hembras, 13,2% y para los machos, 18,9%. Los valores más altos de proteína se obtuvieron en verano para las hembras, 22,0% y para los machos 21,8%. Las variaciones en el contenido de proteínas no fueron significativas (

Cambios en la composición de los ácidos grasos y evaluación de la oxidación de lípidos y proteínas en almejas comerciales (Ruditapes decussatus) cocinadas

This study aimed to provide information about the changes in fatty acid composition and quality in Ruditapes decussatus tissue after four culinary treatments (steamed, baked, grilled and fried). All treated samples showed a significant decrease in moisture and protein. In contrast, a significant increase in fat content resulted from the grilled and fried treatments. Saturated fatty acid was significantly higher in fresh clams than all cooking processes, except in fried ones. Monounsaturated fatty acid and polyunsaturated fatty acid varied significantly between fresh and cooked clams with high values recorded for fried clams. The n-3/n-6 ratio, peroxide index, EPA+DHA and atherogenicity index decreased significantly after the cooking processes particularly in fried clams. The mineral levels (Mg, Ca and Mn) of cooked clams decreased considerably with grilled and fried treatments. The impacts of cooking on the fatty acid composition and protein content in clam tissue was evaluated by lipid peroxidation (TBARS, PV, FFA, TOR) and protein oxidation (AOPP and PCO), which varied statistically in fried, steamed, grilled and baked samples; indicating alterations in cooked clam tissues structure. Based on our results, steaming is recommended for the preparation of clams because it preserves the most nutritional tissue quality.El presente estudio tuvo como objetivo proporcionar información innovadora sobre los cambios en la composición y calidad de los ácidos grasos presentes en el tejido de Ruditapes decussatus tras cuatro tratamientos culinarios distintos (vapor, horno, parrilla y fritura). Todas las muestras tratadas mostraron una disminución significativa en el contenido de humedad y proteínas. Por el contrario, los tratamientos a la parrilla y frito resultaron en un aumento significativo de la cantidad de grasa. El contenido en ácidos grasos saturados fue significativamente mayor en las almejas frescas comparado con todas las almejas cocinadas, a excepción de las fritas. Los ácidos grasos mono- y poliinsaturados variaron significativamente entre las almejas frescas y cocinadas, mostrando el valor más alto en las almejas fritas. La relación n-3/n-6, el índice de peróxidos, el contenido de EPA + DHA y el índice de aterogenicidad disminuyeron significativamente después de todos los procesos de cocción, especialmente en las almejas fritas. Los niveles de minerales (Mg, Ca y Mn) de las almejas cocinadas disminuyeron considerablemente tras los tratamientos a la parrilla y frito. El impacto del cocinado sobre la calidad de los ácidos grasos y las proteínas se evaluó mediante la medida de la peroxidación de lípidos (TBARS, PV, FFA, TOR) y la oxidación de proteínas (AOPP y PCO), valores que variaron significativamente en las muestras fritas, al vapor, a la parrilla y al horno, indicando una alteración de la estructura de los tejidos de la almeja cocinada. De acuerdo a los resultados obtenidos, se recomienda la cocción al vapor para la preparación de las almejas, ya que es el tratamiento que mejor preserva calidad nutricional de los tejidos

Increased percentage of T cells with the expression of CD127 and CD132 in hypertrophic adenoid in children with otitis media with effusion

The hypertrophic adenoid may promote chronic suppurative otitis media in children as it fulfills its immune function. The number of lymphocytes in the adenoid and their cooperation in the immune response depend of on their proliferation and migration to the effector sites. Interleukin 7 (IL-7) is essential for the normal development and function lymphocytes. IL-7 plays pivotal role for activation and proliferation of T and B cells. The heterodimeric interleukin-7 receptor (IL-7R) is composed of the IL-7Rα (127) and the common cytokine receptor γc (CD132). The aim of this study was to evaluate the percentage of lymphocytes T (CD4+ and CD8+) with IL-7R (CD127 and CD132) expression in hypertrophic adenoid in children suffering with otitis media with effusion for a duration of 3 months. Adenoid excised due to hypertrophy with or without chronic otitis media with effusion was used as study material. CD4+ CD127+, CD4+132+, CD8+CD127+ and CD8+CD132+ cell subpopulations were identified using monoclonal antibodies and flow cytometry. The percentage of CD4+ and CD8+ T cells with CD127 receptor expression in hypertrophic adenoid of children with otitis media with effusion was statistically significantly higher than in hypertrophic adenoid group. The percentage of CD4+ T cells with CD132 expression in the study group was statistically significantly higher than in the reference group. The percentage of CD8+ T cells with CD132+ expression was not statistically different in both groups. The increased percentage of T lymphocytes with IL-7R expression (CD127 and CD132) in hypertrophic adenoid seems to influence the quantity of lymphocytes and upset the immunological function of tonsils which can influence the course of otitis media with effusion

Selective Induction of Cell Death in Melanoma Cell Lines through Targeting of Mcl-1 and A1

Melanoma is an often fatal form of skin cancer which is remarkably resistant against radio- and chemotherapy. Even new strategies that target RAS/RAF signaling and display unprecedented efficacy are characterized by resistance mechanisms. The targeting of survival pathways would be an attractive alternative strategy, if tumor-specific cell death can be achieved. Bcl-2 proteins play a central role in regulating survival of tumor cells. In this study, we systematically investigated the relevance of antiapoptotic Bcl-2 proteins, i.e., Bcl-2, Bcl-xL, Bcl-w, Mcl-1, and A1, in melanoma cell lines and non-malignant cells using RNAi. We found that melanoma cells required the presence of specific antiapoptotic Bcl-2 proteins: Inhibition of Mcl-1 and A1 strongly induced cell death in some melanoma cell lines, whereas non-malignant cells, i.e., primary human fibroblasts or keratinocytes were not affected. This specific sensitivity of melanoma cells was further enhanced by the combined inhibition of Mcl-1 and A1 and resulted in 60% to 80% cell death in all melanoma cell lines tested. This treatment was successfully combined with chemotherapy, which killed a substantial proportion of cells that survived Mcl-1 and A1 inhibition. Together, these results identify antiapoptotic proteins on which specifically melanoma cells rely on and, thus, provide a basis for the development of new Bcl-2 protein-targeting therapies

Small interfering RNA targeting mcl-1 enhances proteasome inhibitor-induced apoptosis in various solid malignant tumors

<p>Abstract</p> <p>Background</p> <p>Targeting the ubiquitin-proteasome pathway is a promising approach for anticancer strategies. Recently, we found Bik accumulation in cancer cell lines after they were treated with bortezomib. However, recent evidence indicates that proteasome inhibitors may also induce the accumulation of anti-apoptotic Bcl-2 family members. The current study was designed to analyze the levels of several anti-apoptotic members of Bcl-2 family in different human cancer cell lines after they were treated with proteasome inhibitors.</p> <p>Methods</p> <p>Different human cancer cell lines were treated with proteasome inhibitors. Western blot were used to investigate the expression of Mcl-1 and activation of mitochondrial apoptotic signaling. Cell viability was investigated using SRB assay, and induction of apoptosis was measured using flow cytometry.</p> <p>Results</p> <p>We found elevated Mcl-1 level in human colon cancer cell lines DLD1, LOVO, SW620, and HCT116; human ovarian cancer cell line SKOV3; and human lung cancer cell line H1299, but not in human breast cancer cell line MCF7 after they were treated with bortezomib. This dramatic Mcl-1 accumulation was also observed when cells were treated with other two proteasome inhibitors, MG132 and calpain inhibitor I (ALLN). Moreover, our results showed Mcl-1 accumulation was caused by stabilization of the protein against degradation. Reducing Mcl-1 accumulation by Mcl-1 siRNA reduced Mcl-1 accumulation and enhanced proteasome inhibitor-induced cell death and apoptosis, as evidenced by the increased cleavage of caspase-9, caspase-3, and poly (ADP-ribose) polymerase.</p> <p>Conclusions</p> <p>Our results showed that it was not only Bik but also Mcl-1 accumulation during the treatment of proteasome inhibitors, and combining proteasome inhibitors with Mcl-1 siRNA would enhance the ultimate anticancer effect suggesting this combination might be a more effective strategy for cancer therapy.</p

Uncoupling of the LKB1-AMPKα Energy Sensor Pathway by Growth Factors and Oncogenic BRAFV600E

BACKGROUND: Understanding the biochemical mechanisms contributing to melanoma development and progression is critical for therapeutical intervention. LKB1 is a multi-task Ser/Thr kinase that phosphorylates AMPK controlling cell growth and apoptosis under metabolic stress conditions. Additionally, LKB1(Ser428) becomes phosphorylated in a RAS-Erk1/2-p90(RSK) pathway dependent manner. However, the connection between the RAS pathway and LKB1 is mostly unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the UV induced HGF transgenic mouse melanoma model to investigate the interplay among HGF signaling, RAS pathway and PI3K pathway in melanoma, we identified LKB1 as a protein directly modified by HGF induced signaling. A variety of molecular techniques and tissue culture revealed that LKB1(Ser428) (Ser431 in the mouse) is constitutively phosphorylated in BRAF(V600E) mutant melanoma cell lines and spontaneous mouse tumors with high RAS pathway activity. Interestingly, BRAF(V600E) mutant melanoma cells showed a very limited response to metabolic stress mediated by the LKB1-AMPK-mTOR pathway. Here we show for the first time that RAS pathway activation including BRAF(V600E) mutation promotes the uncoupling of AMPK from LKB1 by a mechanism that appears to be independent of LKB1(Ser428) phosphorylation. Notably, the inhibition of the RAS pathway in BRAF(V600E) mutant melanoma cells recovered the complex formation and rescued the LKB1-AMPKalpha metabolic stress-induced response, increasing apoptosis in cooperation with the pro-apoptotic proteins Bad and Bim, and the down-regulation of Mcl-1. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that growth factor treatment and in particular oncogenic BRAF(V600E) induces the uncoupling of LKB1-AMPKalpha complexes providing at the same time a possible mechanism in cell proliferation that engages cell growth and cell division in response to mitogenic stimuli and resistance to low energy conditions in tumor cells. Importantly, this mechanism reveals a new level for therapeutical intervention particularly relevant in tumors harboring a deregulated RAS-Erk1/2 pathway

Neurorétinite stellaire bilatérale révélant une sténose de l’artère rénale

La neurorétinite stellaire est un syndrome clinique associant une perte brutale de l’acuité visuelle (AV), associant un oedème papillaire et des exsudats en étoile en périmaculaire. Les étiologies de cette affection, sont multiples. Elle doit faire rechercher une cause infectieuse chez le sujet jeune et une cause vasculaire chez le sujet âgé ; La neurorétinite stellaire idiopathique de Leber doit rester un diagnostic d’élimination. Nous rapportons l’observation clinique d’un patient âgé de 63 ans qui consulte pour une baisse bilatérale de l’acuité visuelle, évoluant depuis 3 semaines et chez qui l’examen ophtalmologique trouve une neurorétinite stellaire bilatérale. Le bilan infectieux était négatif et l’IRM orbito-cérébrale était normale.L’examen général a noté une tension artérielle à 270/160 mmHg. Et Le bilan étiologique a révélé une sténose de l’artère rénale droite. Après stabilisation de la tension artérielle, il y a eu régression de l’oedème papillaire et résorption des exsudats maculaires et une amélioration sur le plan fonctionnel