Specific activity of mouse liver desaturases and elongases: Time course effects using n-3 and n-6 PUFA substrates and inhibitory responses of delta-6 desaturase.

The synthesis of n-3 and n-6 polyunsaturated acids (PUFAs) is associated with physiological functions in mammals, being catalyzed by Δ-5D and Δ-6D desaturases and elongases Elovl-2 and Elovl-5. In this context, we aimed to study the chief kinetic features of PUFA liver anabolism, looking upon (i) the time-dependency for the specific activity of Δ-6D, Δ-5D, Elovl2, Elovl2/5 and Elovl5, using n-3 and n-6 precursors between 0 and 240 min ex vivo in mouse liver.; and (ii) the specific activity-substrate (α-linolenic acid; ALA) concentration responses of Δ-6D in the absence and presence of linoleic acid (LA), arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), an enzyme regarded as the rate-limiting step in PUFA anabolism.

[Prognostic factors for survival in children with cancer and febrile neutropenia].

Unlabelled: Cancer remains one of the most important diseases in public health.

Objective: To estimate 5-year survival in pediatric cancer patients affected by FN, according to clinical-demographic variables.

Patients And Method: Survival, prognostic, and analytical study with historical cohort.

Enzymatic Interesterification of Cold-Pressed Maqui ( (Mol.) Stuntz) Seed Oil and Belly Oil from Rainbow Trout () Through Supercritical CO.

A new antioxidant lipid (AL) was synthesized from rainbow trout () belly oil and cold-pressed maqui (CPM) ( (Mol.) Stuntz) seed oil via enzymatic interesterification using in supercritical CO medium. A Box-Behnken design with 15 experiments was employed, with the independent variables being the following: belly oil/CPM oil ratio (10/90, 50/50, and 90/10, /), supercritical CO temperature (40.

Two new species and a new record of Hypoxylaceae (Xylariales, Ascomycota) from Mexico.

The family Hypoxylaceae has a cosmopolitan distribution with greater diversity in tropical regions, its growth habit is saprotrophic, endophytic and potentially phytopathogenic. From the revision of herbarium specimens and field collections from the Yucatan Peninsula, two new species were described: , characterized by having fusiform spores and which is distinguished by having stromata vinaceous and dark brown KOH-extractable pigments. The species are described based on morphological characters and Bayesian Inference analyses of four molecular markers (ITS, LSU, RPB2 and TUB2).

Modulation of Δ5- and Δ6-desaturases in the brain-liver axis.

Objective: Obesity is associated with liver depletion of ω-3 polyunsaturated fatty acids (ω-3 PUFAS) promoting steatosis and inflammation, whose levels are maintained by diet or biosynthesis involving Δ-5D, Δ-6D desaturases and elongases.

Method: We aimed to assess Δ-5D and Δ-6D activities in liver and brain from mice fed a control diet (CD) or high-fat diet (HFD) for four to sixteen weeks.

Results: HFD led to (1) an early (4 weeks) enhancement in liver Δ-5D, Δ-6D, and PPAR-α activities, without changes in oxidative stress, liver damage or fat accumulation; (2) a latter progressive loss in hepatic desaturation with insufficient compensatory increases in mRNA and protein expression, leading to ω-3 PUFA depletion, PPAR-α down-regulation reducing FA oxidation, and liver steatosis with enhancement in lipogenesis; and (3) brain ω-3 PUFA depletion after 12 to 16 weeks of HFD feeding.