Secretory dynamics of ghrelin in adolescent girls with anorexia nervosa and healthy adolescents

Ghrelin is an orexigenic peptide and a growth hormone (GH) secretagogue. Secretory dynamics of ghrelin have not been characterized in adolescents with anorexia nervosa (AN). We hypothesized that, compared with healthy adolescents, girls with AN would have increased ghrelin concentrations measured over 12 h of nocturnal sampling from increased basal and pulsatile secretion, and endogenous ghrelin would independently predict GH and cortisol. We examined ghrelin concentration and secretory dynamics in 22 girls with AN and 18 healthy adolescents 12-18 yr old. Associations between ghrelin, various hormones, and measures of insulin resistance were examined. On Cluster analysis, girls with AN had higher ghrelin concentrations than controls, including total area under the curve (AUC) (P = 0.002), nadir (P = 0.0006), and valley levels (P = 0.002). On deconvolution analysis, secretory burst amplitude (P = 0.03) and burst mass (P = 0.04) were higher in AN, resulting in higher pulsatile (P = 0.05) and total ghrelin secretion (P = 0.03). Fasting ghrelin independently predicted GH burst frequency (r = 0.44, P = 0.005). The nutritional markers body mass index and body fat predicted postglucose and valley ghrelin but not fasting levels. Ghrelin parameters were inversely associated with fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), leptin, and IGF-I. HOMA-IR was the most significant predictor of most ghrelin parameters. Valley ghrelin independently predicted cortisol burst frequency (52% of variability), and ghrelin parameters independently predicted total triiodothyronine and LH levels. Higher ghrelin concentrations in adolescents with AN are a consequence of increased secretory burst mass and amplitude. The most important predictor of ghrelin concentration is insulin resistance, and ghrelin in turn predicts GH and cortisol burst frequency.     

Altered Structural and Functional Connectivity in Late Preterm Preadolescence: An Anatomic Seed-Based Study of Resting State Networks Related to the Posteromedial and Lateral Parietal Cortex

Objective

Late preterm birth confers increased risk of developmental delay, academic difficulties and social deficits. The late third trimester may represent a critical period of development of neural networks including the default mode network (DMN), which is essential to normal cognition. Our objective is to identify functional and structural connectivity differences in the posteromedial cortex related to late preterm birth.

Methods

Thirty-eight preadolescents (ages 9–13; 19 born in the late preterm period (≥32 weeks gestational age) and 19 at term) without access to advanced neonatal care were recruited from a low socioeconomic status community in Brazil. Participants underwent neurocognitive testing, 3-dimensional T1-weighted imaging, diffusion-weighted imaging and resting state functional MRI (RS-fMRI). Seed-based probabilistic diffusion tractography and RS-fMRI analyses were performed using unilateral seeds within the posterior DMN (posterior cingulate cortex, precuneus) and lateral parietal DMN (superior marginal and angular gyri).

Results

Late preterm children demonstrated increased functional connectivity within the posterior default mode networks and increased anti-correlation with the central-executive network when seeded from the posteromedial cortex (PMC). Key differences were demonstrated between PMC components with increased anti-correlation with the salience network seen only with posterior cingulate cortex seeding but not with precuneus seeding. Probabilistic tractography showed increased streamlines within the right inferior longitudinal fasciculus and inferior fronto-occipital fasciculus within late preterm children while decreased intrahemispheric streamlines were also observed. No significant differences in neurocognitive testing were demonstrated between groups.

Conclusion

Late preterm preadolescence is associated with altered functional connectivity from the PMC and lateral parietal cortex to known distributed functional cortical networks despite no significant executive neurocognitive differences. Selective increased structural connectivity was observed in the setting of decreased posterior interhemispheric connections. Future work is needed to determine if these findings represent a compensatory adaptation employing alternate neural circuitry or could reflect subtle pathology resulting in emotional processing deficits not seen with neurocognitive testing.     

Dysbiosis of salivary microbiome and cytokines influence oral squamous cell carcinoma through inflammation

Archives of Microbiology - Advanced combinatorial treatments of surgery, chemotherapy, and radiotherapy do not have any effect on the enhancement of a 5-year survival rate of oral squamous cell...     

Regulatory mechanisms across networks of the circadian clock and senescence pathways

Journal of Plant Biochemistry and Biotechnology - The circadian clock serves the fitness of higher plants by controlling various aspects of plant growth and development ranging from photosynthesis...     

Cultivation of <Emphasis Type="Italic">Gracilaria verrucosa</Emphasis> (Huds) Papenfuss in Chilika Lake for livelihood generation in coastal areas of Orissa State

The agarophyte red alga Gracilaria verrucosa occurs widely in Chilika Lake, one of the RAMSAR wetland sites in India. The lake is situated in the extreme southeast corner of Orissa between latitudes 19°28′ and 19°54′ N and longitudes 85°06′ and 85°35′ E. The natural biomass production is not sufficient for the agar industry, and the only alternative is to maximize the production of the seaweed through mass cultivation by seaweed farming. To elucidate important aspects of the growth and development of G. verrucosa, experimental field cultivation was undertaken at Langaleswar and Samal sites of Chilika Lake using ropes and raft methods during March to August, 2009. After 30 days of cultivation a maximum 15- and 13.8-fold increase in biomass in raft culture and rope culture, respectively, was observed at Langaleswar and an 11.6- and 11.0-fold increase in biomass at Samal. Environmental parameters such as temperature, salinity, pH, transparency, DO, conductivity, nitrate, and phosphate were monitored at both stations, and the influence of environmental parameters is discussed.     

Lower growth hormone and higher cortisol are associated with greater visceral adiposity, intramyocellular lipids, and insulin resistance in overweight girls

Although body composition, insulin sensitivity, and lipids are markedly altered in overweight adolescents, hormonal associations with these parameters have not been well characterized. Growth hormone (GH) deficiency and hypercortisolemia predispose to abdominal adiposity and insulin resistance, and GH secretion is decreased in obese adults. We hypothesized that low-peak GH on the GH-releasing hormone (GHRH)-arginine stimulation test and high cortisol in overweight adolescents would be associated with higher regional fat, insulin resistance, and lipids. We examined the following parameters in 15 overweight and 15 bone age-matched control 12- to 18-yr-old girls: 1) body composition using dual-energy X-ray absorptiometry and MR [visceral and subcutaneous adipose tissue at L(4)-L(5) and soleus intramyocellular lipid ((1)H-MR spectroscopy)], 2) peak GH on the GHRH-arginine stimulation test, 3) mean overnight GH and cortisol, 4) 24-h urinary free cortisol (UFC), 5) fasting lipids, and 6) an oral glucose tolerance test. Stepwise regression was the major tool employed to determine relationships between measured parameters. Log peak GH on the GHRH-arginine test was lower (P = 0.03) and log UFC was higher (P = 0.02) in overweight girls. Log mean cortisol (overnight sampling) was associated positively with subcutaneous adipose tissue and, with body mass index standard deviation score, accounted for 92% of its variability, whereas log peak GH and body mass index standard deviation score accounted for 88% of visceral adipose tissue variability and log peak GH for 34% of the intramyocellular lipid variability. Log mean cortisol was independently associated with log homeostasis model assessment of insulin resistance, LDL, and HDL and explained 49-59% of the variability. Our data indicate that lower peak GH and higher UFC in overweight girls are associated with visceral adiposity, insulin resistance, and lipids.     

New role for tRNA and its fragment purified from human urinary bladder carcinoma conditioned medium: Inhibition of endothelial cell growth

The growth of endothelial cells is necessary for angiogenesis, which in turn is required for later steps of tumor progression. In an attempt to purify new modulators of endothelial cell growth from the conditioned medium of human urinary bladder carcinoma cells, we isolated a small and stable oligonucleotide containing 10 to 16 bases. This oligonucleotide inhibited the growth of endothelial cells in vitro and was identified as a fragment of transfer RNA (tRNA). When unfractionated bovine tRNA was added to the cell culture, it specifically inhibited growth of endothelial cells, but not smooth muscle cells, bovine kidney cells, 3T3 fibroblasts, and several cancer cell lines. In contrast, ribosomal RNA, total yeast RNA, and single nucleosides from tRNA hydrolysate had no effect. These results demonstrate a new role for tRNA and its fragment as a selective endothelial cell inhibitor in vitro. J. Cell. Biochem. 76:109–117, 1999. © 1999 Wiley‐Liss, Inc.     

Chromium bioaccumulation in rice grown in contaminated soil and irrigated mine wastewater--a case study at South Kaliapani chromite mine area, Orissa, India

The level of chromium (Cr) contamination in soils and irrigated mine wastewater at South Kaliapani chromite mine region of Orissa, (India) were investigated. Chromium bioaccumulation in rice plants (Oryza sativa L. cv. Khandagiri) irrigated with Cr+6 contaminated mine wastewater was analyzed along with its attenuation from mine wastewater. The levels of Cr+6 in irrigated mine wastewaters in successive rice grown plots were analyzed on 75 days and 100 days after transplantation of seedlings. Total chromium content in different parts of rice plants and soil samples from different plots was analyzed during harvesting stage (125 days after transplantation). Cr accumulation was significantly high in surface soils (0-20 cm) with a mean value of 11,170 mg kg(-1), but it decreased significantly after the crop harvest. About 70% to 90% reduction of Cr+6 levels was observed in irrigated mine wastewater when passed through successive rice plots. High bio-concentration of Cr in leaves with values ranging from 125-498 mg kg(-1) as compared to stem (25-400 mg kg(-1)) and grain (5-23 mg kg(-1)) was noticed. The reduction of Cr+6 levels is related to plant age, high biomass and area of water passage and was attributed to rhizofiltration technique.     

Antigenicity of filarial superoxide dismutase in human bancroftian filariasis

Superoxide dismutase activity was measured in different stages of growth of filarial parasites (human and cattle). The activity was almost undetected or very low in microfilarial stage but in adult worms, the enzyme activity was high. The enzyme was characterized to be a Cu/Zn superoxide dismutase. Most of the enzyme activity was associated with a detergent extractable fraction of adult (Setaria) parasite. The enzyme was also detected in thein vitro released products of adult worms. The superoxide dismutase activity was completely inhibited with IgG antibody from chronic filarial patients in contrast to IgG from normal people. Filarial patients particularly have high IgG and IgM antibody levels to purified enzyme. However, individuals from non-filarial regions of Orissa are sero-negative for superoxide dismutase antibodies. Antibody response to superoxide dismutase could thus be used for filarial diagnosis.