Short allele of serotonin transporter gene promoter is a risk factor for obesity in adolescents

Obesity and hypertension are increasing medical problems in adolescents. Serotonin transporter (5-HTT) is involved in mood and eating disturbances. Encoded by the gene SLC6A4, the promoter shows functional insertion/deletion alleles: long (L) and short (S). Because individuals who are carriers for the short version are known to be at risk for higher levels of anxiety, we hypothesized that this variant may be associated with overweight. Data and blood samples were collected from 172 adolescents out of a cross-sectional, population-based study of 934 high school students. To replicate the findings, we also included 119 outpatients from the Nutrition and Diabetes Section of the Children's County Hospital. We found that the S allele was associated with overweight (BMI > 85th percentile), being a risk factor for overweight independently of sex, age, and hypertension [odds ratio (OR): 1.85; 95% confidence interval (CI): 1.13, 3.05; p < 0.02]. Additionally, in the outpatient study, compared with the homozygous LL subjects, S allele carriers showed a higher BMI z-score (1.47 +/- 1.09 vs. 0.51 +/- 1.4; p < 0.002) and were more frequent in overweight children. In conclusion, the S allele of the SLC6A4 promoter variant is associated with overweight being an independent genetic risk factor for obesity.     

Plasma visfatin concentrations in severely obese subjects are increased after intestinal bypass

Objective: Visfatin has shown to be increased in obesity and in type 2 diabetes. The aim of this study was to determine the change in plasma visfatin in severely obese (SO) persons after weight loss following bariatric surgery in relation to glucose concentration. Research Methods and Procedures: Visfatin and leptin were studied in 53 SO persons (BMI, 54.4 ± 6.8 kg/m²) before and 7 months after bariatric surgery and in 28 healthy persons (BMI, 26.8 ± 3.8 kg/m²). All of the patients underwent bariatric surgery with biliopancreatic diversion or gastric bypass. Results: The pre‐surgery levels of visfatin in the SO group were greater than in the control group (55.9 ± 39.9 vs. 42.9 ± 16.6 ng/mL, p = 0.024). This increase was significant in the SO group with impaired fasting glucose (63.4 ± 36.6 ng/mL) and diabetes (60.0 ± 46.0 ng/mL). SO patients with normal fasting glucose had similar levels of visfatin to the controls. Seven months after surgery, visfatin levels were significantly increased (84.8 ± 32.8 ng/mL, p < 0.001). This increase was independent of the pre‐surgical glucose levels. The type of bariatric surgery had no influence on visfatin levels. Post‐surgical visfatin was significantly correlated with the post‐surgery plasma concentrations of leptin (r = 0.39, p = 0.014). Discussion: Plasma levels of visfatin in the SO group were increased but only when accompanied by high glucose levels, even in the range of impaired fasting glucose. Bariatric surgery causes an increase in visfatin, which is correlated mainly with the changes produced in the leptin concentration.     

Regulation of Nitrate Transport in Citrus Rootstocks Depending on Nitrogen Availability

Previously, we reported that in Citrus plants, nitrate influx through the plasmalemma of roots cells follows a biphasic pattern, suggesting the existence of at least two different uptake systems, a high and low affinity transport system (HATS and LATS, respectively). Here, we describe a novel inducible high affinity transport system (iHATS). This new nitrate transport system has a high capacity to uptake nitrate in two different Citrus rootstocks (Cleopatra mandarin and Troyer citrange). The iHATS was saturable, showing higher affinity than constitutive high affinity transport system (cHATS) to the substrate NO₃⁻. The V_max for this saturable component iHATS was higher than cHATS, reaching similar values in both rootstocks.Additionally, we studied the regulation of root NO₃⁻ uptake mediated by both HATS (iHATS and cHATS) and LATS. In both rootstocks, cHATS is constitutive and independent of N-status. Concerning the regulation of iHATS, this system is upregulated by NO₃⁻ and down-regulated by the N status and by NO₃⁻ itself when plants are exposed to it for a longer period of time. LATS in Cleopatra mandarin and Troyer citrange rootstocks is repressed by the N-status.The use of various metabolic uncouplers or inhibitors indicated that NO₃⁻ net uptake mediated by iHATS and LATS was an active transport system in both rootstocks.Key Words: Citrus, inducible high affinity transport system (iHATS), constitutive high affinity transport system (cHATS), nitrate uptake, regulation     

Colour‐based foraging diverges after multiple generations under different light environments

When the environment changes, sensory systems can adapt plastically or evolve genetically to the new surroundings, and traits and behaviours reliant on these sensory systems may also change, leading to altered evolutionary trajectories. We tested for differences in colour‐based foraging preferences of guppies (Poecilia reticulata) that lived for 6–10 generations under each of three light environments (green, lilac or control) to determine whether evolution under different light environments alters visually based behaviour. When tested in a common light environment, we found differences in pecking behaviour between treatments that were likely due to changes in the visual system. Pecking behaviour towards green stimuli was consistent across light treatments, possibly reflecting the importance of detecting green algae in the wild. The blue stimulus was only pecked at by fish from the control environments. Behaviour towards long wavelength stimuli varied, possibly due to the polymorphic nature of the long wavelength opsins. These results are consistent with one component of sensory drive but do not allow us to conclude whether these differences are due to plastic or evolved responses.     

Evidence for both humoral and neural regulation of sex pheromone biosynthesis in Spodoptera littoralis

Selected tissues presumably involved in the control of sex pheromone production were analyzed by ELISA for the presence of PBAN-like immunoreactivity (PBAN-IR) in Spodoptera littoralis. The temporal distribution pattern of PBAN-IR in the hemolymph is similar to that of pheromone production in the gland. On the other hand, analysis of the retrocerebral complex, brain-subesophageal ganglion complex, and terminal abdominal ganglion (TAG) revealed similar PBAN-IR levels in both photophase and scotophase periods. Pheromonotropic activity exhibited by both hemolymph and TAG, as determined by a modified in vitro bioassay, agrees with the results of the immunochemical analyses. Severing the ventral nerve cord anterior to the TAG impaired normal sex pheromone production by second-scotophase females. These results are discussed in the context of how sex pheromone biosynthesis is regulated by PBAN in S. littoralis. © 1996 Wiley-Liss, Inc.     

Toxic action of etoposide on mouse peritoneal macrophages and its modulation by interleukin 3

In the present work, we have studied the toxic action of etoposide on mouse peritoneal macrophages. First, we have determined the induction of DNA fragmentation by this antitumour compound. To study the possible influence of interleukin 3 on the effects of etoposide on mouse macrophages, we studied intracellular protein phosphorylation induced by interleukin 3. After incubation of the cells in the presence of interleukin 3, increased phosphorylation levels of proteins of estimated molecular weights of around 29,000, 34,000, 50,000 and 61,000 daltons were observed. We have also investigated a possible influence of interleukin 3 on DNA degradation induced by etoposide. The changes of Bax levels induced by etoposide that we have observed seemed to be modulated by this cytokine. From these results, a possible role of interleukin 3 can be suggested in the attenuation of some toxic effects produced by etoposide in mouse peritoneal macrophages. Thus, a therapeutic application of interleukin 3 on antitumour treatments in cells from the mononuclear phagocytic system might be proposed.     

Proteomic signature of human cancer cells

We assessed proteomic profiles as biomarkers for monitoring cell phenotypes. Protein expression profiles were obtained by fluorescence two-dimensional difference gel electrophoresis (2-D-DIGE), in which quantitative ability is improved by labeling proteins with fluorescent dyes prior to electrophoresis. Integrated protein spot intensities were analyzed by a statistical approach. The proteomic data of two groups of cell lines: (1) adenocarcinoma (AC) cell lines derived from lung, pancreas and colon tissues and (2) lung cancer cell lines with different histological backgrounds, including AC, squamous cell carcinoma and small cell carcinoma, were assessed on the basis of prior biological information. Hierarchical clustering analysis and principal component analysis were used to divide the cell lines into subgroups on the basis of similarities between their protein expression profiles. The majority of cell lines were grouped according to their organ of origin or histological background. A machine-learning algorithm selected 32 protein spots that were responsible for the classification. The results indicate that proteomic data generated by 2-D-DIGE can provide a signature of essential cell phenotypes, suggesting that it might be possible to apply this technique to developing tumor markers that could identify the organ of origin of metastatic tumors and contribute to the differential diagnosis of lung cancer.