Search

Neuropeptide hormones produced by neurosecretory cells in the central or peripheral nervous systems regulate various physiological and behavioral events during insect development and reproduction. PBAN/Pyrokinin is a major neuropeptide family, characterized by a 5-amino-acid C-terminal sequence, FXPRLamide. This family of peptides has been implicated in regulating various physiological functions including, pheromone biosynthesis, muscle contraction, diapause induction or termination, melanization, and puparium formation in different insect species. In the present study, we report a new member of the PBAN family from the red imported fire ant, Solenopsis invicta, Soi-PBAN, composed of 26-AA (GSGEDLSYGDAYEVDEDDHPLFVPRL). Three additional peptides were deduced from Soi-PBAN cDNA: 15-AA (TSQDIASGMWFGPRL), 8-AA (QPQFTPRL) and 9-AA (LPWIPSPRL), that correspond to diapause hormone (DH), β-neuropeptide (NP), and γ-NP, which are found in many lepidopteran moths. Five peptides, DH, α, β, γ NPs, and PBAN are encoded from PBAN genes of lepidopteran moths, but in the fire ant the α-NP is missing. Each of the four synthetic peptides from the fire ant Soi-PBAN cDNA showed significant pheromonotropic activity in a moth model, indicating that these peptides are cross-reactive. Soi-β-NP induced the highest amount of pheromone production of the four peptides evaluated. The Soi-DH homologue had the lowest pheromonotropic activity, but was still significantly greater than control values. When the deduced amino acid sequences (entire ORF domains) from Soi-PBAN cDNA were compared with other known sequences, the fire ant was most similar to the honey bee, but phylogenetically distant from moth and beetle species. Soi-PBAN (26-AA) unlike the other three peptides shows a low degree of sequence identity with honeybee PBAN (33-AA). Based on the amino acid sequences encoded from insect PBAN genes identified to date, neuropeptide diversity is correlated with the taxonomic or phylogenetic classification of Insecta. From the present study we report the first neuropeptide identified and characterized from the central nervous system of Formicidae. [ABSTRACT FROM AUTHOR]

Systematic risk assessment and training courses have been suggested as interventions to deal with patient violence in psychiatric institutions. A dual centre prospective feasibility study was conducted on two Swiss psychiatric admission wards to test the hypothesis that such interventions will reduce the frequency and severity of violent events and coercion. A systematic aggression risk assessment, in combination with a standardized training course in aggression management was administered and the frequency and severity of aggressive incidents and the frequency of coercive measures were registered. The incidence rates of aggressive incidents and attacks showed no significant reduction from the baseline through risk prediction and staff training, but the drop in coercive measures was highly significant. A 'ward effect' was detected with one ward showing a decline in attacks with unchanged incidence rates of coercion and the other ward showing the opposite. The severity of the incidents remained unchanged whilst the subjective severity declined after the training course. We conclude that a systematic risk assessment and a training course may assist in reducing the incidence rate of coercive measures on psychiatric acute admission wards. Further testing of the interventions is necessary to measure the effect of the training alone and to counteract 'ward effects'. [ABSTRACT FROM AUTHOR]

Abstract Background In Western societies colonic cancer most frequently develops in the distal colon, largely as a result of the composition of the diet. Modulation of dietary factors is therefore an attractive modality to reduce colorectal cancer risk. This study aims to evaluate the potentially protective effects of calcium in right hemicolectomy patients. Materials and methods A randomized controlled cross-over intervention trial was performed with 1000 mg of elemental calcium per day for 2 months in 15 right hemicolectomy patients. Primary endpoints were proliferative activity, determined by immunohistochemical detection of BrdU-labeled cells (LI) in rectal biopsies, and cytotoxicity and alkaline phosphatase activity of faecal water. Secondary endpoints were bile acid composition in faeces. Results Calcium-reduced LI in the superficial one-third of the crypt (from 0·84 ± 0·27% to 0·37 ± 0·08%, P = 0·04) and a trend towards a lower total LI and LI in the mid one-third of the crypt was observed. Alkaline phosphatase activity was reduced from 6·2 ± 2·6 U mL-1 in the placebo period to 4·6 ± 2·2 in the calcium period (P = 0·02), and a trend toward a lower cytotoxicity of faecal water was observed. No effect on total bile acids in faeces was observed, but calcium increased the percentage of deoxycholic acid (from 49·6 ± 7·0% to 56·5 ± 6·2%, P = 0·03) and decreased the percentages of cholic acid (from 10·3 ± 4·7% to 5·8 ± 2·7%, P = 0·05) and lithocholic acid (from 26·7 ± 3·4% to 23·9 ± 2·9%, P = 0·04). Conclusion Calcium may have a protective effect against colorectal cancer risk in right hemicolectomy patients. [ABSTRACT FROM AUTHOR]

Substitution of casein for soybean protein in the diet causes high degrees of hypercholesterolemia in rabbits. When rats or humans were fed exactly the same diets, no response of the concentration of serum cholesterol to the type of protein was observed. The hypothesis is put forward that, in rabbits, dietary casein and peptides derived from it-because of their high degree of phosphorylation-inhibit the binding of glycine-conjugated bile acids to insoluble calcium phosphate in the intestinal lumen. As a result, feeding of casein causes an increase in the availability of bile acids, which leads to enhanced absorption of bile acids and cholesterol. Eventually, the concentration of serum cholesterol will be increased. In rabbits this cascade of events occurs because these animals have a relatively low activity of intestinal alkaline phosphatase, and a high ratio of glycine to taurine in conjugated bile acids. Unlike glycine conjugates, taurine-conjugated bile acids do not effectively bind to the intestinal calcium-phosphate sediment. The low activity of intestinal alkaline phosphatase in rabbits secures the high degree of phosphorylation of casein and its peptide products in the small intestine. In contrast with rabbits, rats and humans have high activities of intestinal alkaline phosphatase and a low glycine-to-taurine ratio in conjugated bile acids. Thus the hypothesis presented would explain why rabbits, but not rats and humans, are susceptible to dietary casein with respect to the concentration of serum cholesterol. The relevance of the hypothesis as to the mechanisms underlying the hypercholesterolemic effect of some other dietary proteins is discussed. [ABSTRACT FROM AUTHOR]

Background: Nitric oxide (NO) production catalyzed by iNOS (inducible NO synthase) is thought to take place mainly in macrophages after activation by inflammatory mediators. NO is subsequently oxidized to nitrite and nitrate, which are excreted in urine. The concentration of inflammatory mediators in small bowel biopsy specimens from patients with coeliac disease is increased. The latter could induce increased NO production by stimulation of intestinal macrophage iNOS, resulting in high levels of urinary NO oxidation products, nitrite and nitrate (NOx). Aim: In the present study we evaluated the urinary NOx/creatinine ratios in children with active coeliac disease (n= 22), coeliac disease patients on a gluten-free diet (n= 9), healthy (n= 11) and sick control children (n= 18). Methods: The Griess reagent method was used for measuring urinary NOx. Results: Median NOx/creatinine ratios of active coeliac disease patients, coeliac disease patients on a gluten-free diet, healthy and sick control patients were 1.21, 0.19, 0.10 and 0.13 mmol/mmol, respectively. All active coeliac disease patients showed increased NOx/creatinine ratios. Urinary NOx/creatinine ratios of the active coeliac disease patients were significantly higher than those of healthy controls (p< 0.0001), sick controls (p< 0.0001) and coeliac disease patients on a gluten-free diet (p< 0.0001). Conclusion: The urinary NOx/creatinine ratio is increased in patients with active coeliac disease and reverts to normal on a gluten-free diet. [ABSTRACT FROM AUTHOR]