Objective(s): Folic acid, a micronutrient supporting the natural defense system, may elevate antidepressant responses, although the lymphocyte serotonergic system has not been explored in folate-supplemented depressed patients. Methods: Twenty-seven patients were randomly assigned to groups receiving fluoxetine (20 mg) and folic acid (10 mg/day) or fluoxetine and placebo for 6 weeks. Clinical outcome was assessed according to the Hamilton Depression Rating Scale (HDRS) at the beginning, during and at the end of treatment. Blood samples were taken, plasma was separated, and lymphocytes were obtained by density gradient centrifugation with Ficoll/Hypaque and differential adhesion to plastic dishes. Fifteen healthy subjects served as controls. Plasma folate, homocysteine and vitamin B₁₂, and serotonin concentration in lymphocytes were determined by HPLC. The HDRS score was significantly lower in patients receiving fluoxetine and folic acid compared with those receiving fluoxetine and placebo after 6 weeks of treatment (7.43 ± 1.65 vs. 11.43 ± 1.31, respectively; p = 0.04). Plasma homocysteine statistically significant decreased after folic acid (p = 0.02), but no significant changes were observed in vitamin B₁₂. Results: Serotonin was significantly reduced after fluoxetine either with folate (p = 0.03) or placebo (p = 0.01) probably by the effect of transporter blockade. 5-Hydroxyindoleacetic acid was lower in lymphocytes of patients receiving folate (p = 0.04), indicating a reduced turnover rate, thus accumulating serotonin in the cells. A significant negative correlation was noted between homocysteine and folate. No significant correlations were present among biochemical parameters and depression severity. Conclusion: Modifications due to treatment with fluoxetine and folic acid may alter lymphocyte function in depression probably indirectly by reducing homocysteine levels and directly on lymphocytes by modifying the serotonergic system.

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Renal inflammation and oxidative stress are constantly present in experimental hypertension. Since the spontaneously hypertensive rat (SHR) has reduced levels of hepatocyte growth factor (HGF), which suppresses the activation of the proinflammatory nuclear transcription factor kappa B (NF-κB), we speculated that HGF deficiency could play a key role in the pathogenesis of hypertension in the SHR. To test this hypothesis we increased HGF in the SHR by HGF gene delivery. We found that kidneys of 15-week-old SHR had an important reduction in HGF mRNA and protein expression. Adult SHRs were randomly assigned to receive weekly hydrodynamic injection (1mg/kg) of a naked plasmid containing human HGF (hHGF) gene associated with a cytomegalovirus promoter (pCMV-HGF) or empty vector (pcDNA3.1) during 6weeks. WKY rats treated with pcDNA3.1 and pCMV-HGF served as controls. The kidneys in the hypertensive SHR untreated and treated with the empty vector had increased NF-κB activation, elevated mRNA and protein expression of RANTES, MCP-1 and IL-6 and increased oxidative stress. Activity of Na(+)-ATPase was increased while activity of Na(+), K(+)-ATPase was normal. hHGF gene therapy normalized renal NF-κB activity, proinflammatory cytokines, antioxidant status (GSH, SOD and CAT), Na(+)-ATPase activity, reduced renal injury and ameliorated hypertension. Our results suggest that reduction in HGF production plays a major role in the pathogenesis of hypertension in the SHR and increasing HGF is a potential therapeutic target in the treatment of hypertension.

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INTRODUCCIóNLas raíces y tubérculos tropicales son considerados alimentos básicos en la dieta de los pobladores de América Latina, África y Asia; y a pesar de que un gran número de estos cultivos se podrían desarrollar a nivel mundial, sólo cinco especies ocupan el 99% del total de la producción papa (Solanum tuberosum), yuca (Manihot esculenta), batata (Ipomoea batatas), ñame (Dioscorea spp.) y ocumo (Colocassia, Cytosperma, Xanthosoma spp.) (1).En Venezuela, la mayoría de los cultivos de raíces y tubérculos, entre ellos la batata, ocumo, apio (Arracacia xanthorrhiza) y ñame, se manejan en el ámbito de pequeños sembradíos y se comercializan principalmente a nivel nacional, teniendo un valor comercial bastante escaso en los canales internacionales, por no incursionar estos mercados. En general, estos rubros son perecederos y se caracterizan por tener un elevado contenido de humedad, resultando como consecuencia pérdidas postcosecha que alcanzan hasta un 30% a nivel mundial (2).El ñame es un cultivo que pertenece a la familia Dioscoreaceae, recomendado como alimento energético debido a que presenta un alto contenido de almidón (70 a 80% de su peso en materia seca), y una concentración de proteínas del 12%, que se considera superior a la determinada para otras raíces y tubérculos tropicales, mostrando un buen balance de aminoácidos esenciales (3). Además, contiene fibra dietaria (7 a 8%), compuestos antioxidantes, vitaminas y minerales, tales como ácido ascórbico (30 μg/g), calcio (140 μg/g) y fósforo (430 ABSTRACT The tubercles of Dioscorea alata which belongs to the Dioscoraceae family are rhizomes, which are cultivated in the tropical and subtropical regions of the world; representing an energetic food source for these populations due to its high contents of starch. In order to increase and diversify its consumption, it was proposed to study the addition of extruded yam flour for the elaboration of a powder mixture for making vanilla-flavored instant drinks. Two formulations were made based on 20% and 40% of extruded yam flour; they were evaluated in function to their chemical composition, physical characteristics (water activity, color, pH and viscosity) and sensorial properties. The results indicated that the addition of the extruded yam flour allowed to increase the protein and dietary fiber contents, with values of water activity, pH and viscosity similar to those of the commercial product that was taken as a reference. The sensorial evaluation resulted of good approval for the studied formulations. In conclusion, the formulation based upon 20% of extruded yam flour, allowed obtaining a product with chemical, physical and sensorial properties comparables to the commercial product; but with antioxidant properties ascribed to some polyphenols originated from the extruded yam flour.

The drug 4-aminopyridine (4-AP) at a dose of 0.2 mg-kg -~ body weight intravenously is an effective antagonist of non-depolarizing neuromuscular blockade. We studied its cardiovascular effects in the canine heart using a right-heart bypass with extracorporeal circulation in seven dogs. This study demonstrates that 4-aminopyridine significantly augments arterial blood pressure, left ventricular dp]dt maximum, as well as left ventricular pressure at dp/dt mx. The highest values were obtained between two and 20 minutes after administration of 4-AP. Left ventricular end-diastolic pressure diminished slightly, but this was not statistically significant. Although the exact mechanism of action of 4-AP is not known, its positive inotropic effects may be of value in the reversal of non-depolarizing neuromuscular blockade in patients with impaired myocardial function of diverse aetiologies and it would be contraindicated in patients with arterial hypertension and/or coronary artery disease.

Soil mechanical resistance to root penetration and shape of the reserve root of sweet potato from the Huaman descriptor. A study was carried out in order to evaluate the influence of mechanical resistance to root penetration (PR), in a soil affected by tillage and seeding distance, on the shape of the reserve root of a sweet potato crop (Ipomoea batatas (L.) Lamb). Experimental design was based on a strip plot arrangement, where big lots were assigned to tillage systems (TS) and seeding density (SD) to strips. The TS consisted of: 1) deep vertical tillage with chisel (CT); 2) tillage with disc plow (DT); 3) conventional tillage with 3 harrow passes (CoT); and 4) minimum tillage with one harrow pass (MT). With 4 tillage working depths of 18, 23, 12 y 7 cm, respectively. The SD were of 0.25 cm (D1) and 0.15 cm (D2) on the crop row. RP average was higher at deeper soil layers for MT treatments (5-15, 15-25 cm) by 44 and 37%, with respect to that observed at same soil layers in the rest of tillage systems. There was scant difference between medium and deep tillage systems (CoT, CT, DT) for PR. The shape of the reserve root was variable, a rounded shape found mostly in MT treatments, contrary to that expected considering RESUMENSe estableció un ensayo para determinar la influencia de la resistencia mecánica a la penetración de raíces (RP), en un suelo afectado por la labranza y por la distancia de siembra, sobre la forma de la raíz reservante del cultivo batata (Ipomoea batatas (L.) Lamb). El diseño del experimento se basó en un arreglo en franjas, donde los sistemas de labranza (SL) fueron asignados a las parcelas grandes y las densidades de siembra (DS) a las franjas. Los SL consistieron en: 1) labranza vertical profunda con cincel y 3 pases de rastra (LC); 2) profunda con arado de disco y 3 pases de rastra (LA); 3) media con 3 pases de rastra de disco (LCo); y 4) mínima con un pase de rastra de disco (LM). Con 4 profundidades de trabajo de 18, 23, 12 y 7 cm, respectivamente. Las DS fueron de 0,25 cm (D1) y 0,15 cm (D2) en la hilera. La RP fue superior en los estratos del suelo a profundidades de 5 a 15 y 15 a 25 cm en los tratamientos de LM, (44 y 37%, respectivamente), respecto al promedio observado en el resto de los tratamientos en los estratos mencionados. Hubo escasa diferenciación entre los sistemas de labranza media y profunda (LCo, LC, LA) para RP. Se encontraron formas redondeadas preferiblemente en los tratamientos * Universidad Central de Venezuela, Facultad de Agronomía, Venezuela.