467 research outputs found
Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate, to produce 2-
oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to
isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine
synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures
of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay
and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or
upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear
increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate
concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity,
possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that
isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of
the cells in Prochlorococcus
Growth Dynamics and Water Potential Components of Three Summer Squash (Cucurbita pepo L.) Cultivars
Summer squash fruit is a horticultural crop that possesses a very short postharvest life due to its high rates of metabolism and transpiration along with a low cuticle resistance exhibited mainly when the fruit is harvested at horticultural maturity. This research was realized following the fruit growth of the summer squash cultivars: âEnterpriseâ, âPascolaâ and âHurakan F1â, whose seeds were germinated in polystyrene trays and their seedlings were subsequently transferred to pots for optimum growth under greenhouse conditions. Fruits were sampled at 3, 5, 7 and 9 days after anthesis (DAA). Physical (weight, diameter, and length of fruit), chemical (pH, titratable acidity and total soluble solids), hydric status (water, osmotic and pressure potentials), and histological analysis were done. The highest number of fruits having marketing quality were shown in both âPascolaâ and âHurakan F1â cultivars at 7 DAA, whereas, in âEnterpriseâ was shown at 9 DAA. Marketing quality fruits from the three cultivars showed similarities on pH (about 6.6), titratable acidity (TA) decreases in âEnterpriseâ and âHurakan F1â, whereas total soluble solids (TSS) decreases in âPascolaâ and âHurakan F1â (pJ 0.5). From 3 to 9 DAA, in all cultivars, the water potential was close to -1.0 MPa, the osmotic potential showed an increasing pattern ranging between -1.59 and -1.15 MPa, and the pressure potential remained in the positive range. Tissue water stability was histologically related to a well-defined parenchyma tissue showing thin-walled, polygonal, intact and turgid cells during fruit growth
Dietary Intervention Modulates the Expression of Splicing Machinery in Cardiovascular Patients at High Risk of Type 2 Diabetes Development: From the CORDIOPREV Study
Type-2 diabetes mellitus (T2DM) has become a major health problem worldwide. T2DM risk can be reduced with healthy dietary interventions, but the precise molecular underpinnings behind this association are still incompletely understood. We recently discovered that the expression profile of the splicing machinery is associated with the risk of T2DM development. Thus, the aim of this work was to evaluate the influence of 3-year dietary intervention in the expression pattern of the splicing machinery components in peripheral blood mononuclear cells (PBMCs) from patients within the CORDIOPREV study. Expression of splicing machinery components was determined in PBMCs, at baseline and after 3 years of follow-up, from all patients who developed T2DM (Incident-T2DM, n = 107) and 108 randomly selected non-T2DM subjects, who were randomly enrolled in two healthy dietary patterns (Mediterranean or low-fat diets). Dietary intervention modulated the expression of key splicing machinery components (i.e., up-regulation of SPFQ/RMB45/RNU6, etc., down-regulation of RNU2/SRSF6) after three years, independently of the type of healthy diet. Some of these changes (SPFQ/RMB45/SRSF6) were associated with key clinical features and were differentially induced in Incident-T2DM patients and non-T2DM subjects. This study reveals that splicing machinery can be modulated by long-term dietary intervention, and could become a valuable tool to screen the progression of T2DM
El suelo y su multifuncionalidad: ¿qué ocurre ahà abajo?
Se expone la definiciĂłn del suelo y su relaciĂłn con sus procesos de formaciĂłn. Asimismo, se destaca y ejemplifica la importancia ambiental y agrĂcola del suelo como un sistema multifuncional esencial para la recirculaciĂłn de los nutrimentos, hĂĄbitat de microbiodiversidad, almacĂ©n de carbono y como proveedor de alimentos y otros servicios ambientales cruciales para el mantenimiento de la biodiversidad del planeta. Finalmente, se discute sobre las actuales estrategias y perspectivas para su estudio en MĂ©xico, dado que se trata de un recurso natural no renovable y clave para nuestra seguridad ambiental y alimentaria
Influence of Gender in Advanced Heart Failure Therapies and Outcome Following Transplantation
Biological differences between males and females change the course of different diseases and affect therapeutic measures' responses. Heart failure is not an exception to these differences. Women account for a minority of patients on the waiting list for heart transplantation or other advanced heart failure therapies. The reason for this under-representation is unknown. Men have a worse cardiovascular risk profile and suffer more often from ischemic heart disease. Conversely, transplanted women are younger and more frequently have non-ischemic cardiac disorders. Women's poorer survival on the waiting list for heart transplantation has been previously described, but this trend has been corrected in recent years. The use of ventricular assist devices in women is progressively increasing, with comparable results than in men. The indication rate for a heart transplant in women (number of women on the waiting list for millions of habitants) has remained unchanged over the past 25 years. Long-term results of heart transplants are equal for both men and women. We have analyzed the data of a national registry of heart transplant patients to look for possible future directions for a more in-depth study of sex differences in this area. We have analyzed 1-year outcomes of heart transplant recipients. We found similar results in men and women and no sex-related interactions with any of the factors related to survival or differences in death causes between men and women. We should keep trying to approach sex differences in prospective studies to confirm if they deserve a different approach, which is not supported by current evidence
La resistencia femenina en el campo mexicano. Un anĂĄlisis agrario en el estado de Hidalgo / A resistĂȘncia das mulheres no campo mexicano. Uma anĂĄlise agrĂĄria no estado de Hidalgo
El presente trabajo centrĂł su anĂĄlisis en los diferentes papeles y relaciones de las mujeres en los sistemas de producciĂłn ovino (SPO) desde un enfoque ambiental productivo. El cual tuvo como objetivo principal identificar las principales prĂĄcticas agro-productivas; cuya finalidad fue obtener informaciĂłn que permitiera diferenciar sus necesidades y prioridades particulares a fin de la comprensiĂłn de diversas oportunidades, formas de participaciĂłn y beneficios ambientales que determinan la continuidad de los SPO. AsĂ como los apoyos necesarios que se requieren en la zona para que los SPO continĂșen vigentes en once de las comunidades indĂgenas del municipio de San Salvador, Estado de Hidalgo.Entre los principales resultados se destaca que la mayorĂa (77%) de las SPO que realizĂł el pastoreo extensivo se encuentra a cargo de mujeres que no han contado con apoyo de gobiernos, municipales, estatales o federales. Los factores asociados con la desigualdad de las mujeres estĂĄn relacionados con la educaciĂłn, la propiedad de activos agropecuarios y la nula remuneraciĂłn en las actividades agropecuarias. La alta migraciĂłn de los hombres en el municipio de San Salvador es uno de los principales factores que han permitido que la mujer quede incluida en el ĂĄmbito agropecuario. Sin embargo, la falta de polĂticas pĂșblicas no ha favorecido el trabajo de las mujeres, quienes consideran el campo como la principal fuente de trabajo y en algunos casos la Ășnica que les permite cumplir con sus necesidades bĂĄsicas de sustento familiar
Preoperative toxoplasma gondii serostatus does not affect long-term survival of cardiac transplant recipients: analysis of the Spanish Heart Transplantation Registry
[Abstract] Background. It's unclear whether pre-transplant T. gondii seropositivity is associated with impaired survival in heart transplant recipients.
Objectives. To test the above-mentioned hypothesis in the Spanish Heart Transplantation Registry.
Methods. Post-transplant outcomes of 4048 patients aged > 16 years who underwent first, single-organ heart transplantation in 17 Spanish institutions from 1984 to 2014 were studied. Long-term post-transplant survival and survival free of cardiac death or retransplantation of 2434 (60%) T. gondii seropositive recipients and 1614 (40%) T. gondii seronegative recipients were compared.
Results. T. gondii seropositive recipients were older, had higher body mass index, and presented higher prevalence of hypertension, hypercholesterolemia, COPD and Cytomegalovirus seropositivity than T. gondii seronegative recipients. In univariable analysis, pre-transplant T. gondii seropositivity was associated with increased post-transplant all-cause mortality (non-adjusted HR 1.15; 95% CI 1.04â1.26). However, this effect was no longer statistically significant after multivariable adjustment by recipient's age and sex (adjusted HR 1.01, 95% CI 0.92â1.11). Extended multivariable adjustment by other potential confounders showed similar results (adjusted HR 0.99, 95% CI 0.89â1.11). T. gondii seropositivity had no significant effect on the composite outcome cardiac death or retransplantation (non-adjusted HR 1.08, 95% CI 0.95â1.24, p = 0.235). The distribution of the causes of death was comparable in T. gondii seropositive and T. gondii seronegative recipients. No statistically significant impact of donor's T. gondii serostatus or donor-recipient T. gondii serostatus matching on post-transplant survival was observed.
Conclusions. Our analysis did not show a significant independent effect of preoperative T. gondii serostatus on long-term outcomes after heart transplantation
Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines
Background: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions
and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools.
Methods: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of
various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We
came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, see Supplementary data) concluded the following:
Results: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing
complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications
should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50â200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added.
Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico.
Conclusions: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed
Amplified Genes May Be Overexpressed, Unchanged, or Downregulated in Cervical Cancer Cell Lines
Several copy number-altered regions (CNAs) have been identified in the genome of cervical cancer, notably, amplifications of 3q and 5p. However, the contribution of copy-number alterations to cervical carcinogenesis is unresolved because genome-wide there exists a lack of correlation between copy-number alterations and gene expression. In this study, we investigated whether CNAs in the cell lines CaLo, CaSki, HeLa, and SiHa were associated with changes in gene expression. On average, 19.2% of the cell-line genomes had CNAs. However, only 2.4% comprised minimal recurrent regions (MRRs) common to all the cell lines. Whereas 3q had limited common gains (13%), 5p was entirely duplicated recurrently. Genome-wide, only 15.6% of genes located in CNAs changed gene expression; in contrast, the rate in MRRs was up to 3 times this. Chr 5p was confirmed entirely amplified by FISH; however, maximum 33.5% of the explored genes in 5p were deregulated. In 3q, this rate was 13.4%. Even in 3q26, which had 5 MRRs and 38.7% recurrently gained SNPs, the rate was only 15.1%. Interestingly, up to 19% of deregulated genes in 5p and 73% in 3q26 were downregulated, suggesting additional factors were involved in gene repression. The deregulated genes in 3q and 5p occurred in clusters, suggesting local chromatin factors may also influence gene expression. In regions amplified discontinuously, downregulated genes increased steadily as the number of amplified SNPs increased (p<0.01, Spearman's correlation). Therefore, partial gene amplification may function in silencing gene expression. Additional genes in 1q, 3q and 5p could be involved in cervical carcinogenesis, specifically in apoptosis. These include PARP1 in 1q, TNFSF10 and ECT2 in 3q and CLPTM1L, AHRR, PDCD6, and DAP in 5p. Overall, gene expression and copy-number profiles reveal factors other than gene dosage, like epigenetic or chromatin domains, may influence gene expression within the entirely amplified genome segments
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