Anti-inflammatory effects of leptin and cholecystokinin on acetic acid-induced colitis in rats: role of capsaicin-sensitive vagal afferent fibers

Leptin and cholecystokinin (CCK) have a synergistic interaction in the suppression of food intake, and afford similar gastroprotective activity. The present study was designed to investigate the putative protective effects of CCK and leptin on acute colonic inflammation. Leptin or CCK-8s was injected to rats intraperitoneally immediately before and 6 h after the induction of colitis with acetic acid. CCK-A receptor antagonist (L-364,718) or CCK-B receptor antagonist (L-365,260) was injected intraperitoneally 15 min before leptin or CCK treatments. In a group of rats, vagal afferent fibers were denervated by topical application of capsaicin on the cervical vagi. Rats were decapitated at 24 h, and the distal 8 cm of the colon were removed for macroscopic scoring, determination of tissue wet weight index (WWI), histologic assessment and tissue myeloperoxidase (MPO) activity. All inflammation parameters were increased by acetic acid-induced colitis compared to control group. Leptin or CCK-8s treatment reduced these parameters in a similar manner, while co-administration of leptin and CCK was found to be more effective in reducing the macroscopic score and WWI. CCK-8s-induced reduction in the score and WWI was prevented by CCK-A, but not by CCK-B receptor antagonist, whereas neither antagonist altered the inhibitory effect of leptin on colitis-induced injury. On the other hand, perivagal capsaicin prevented the protective effects of both CCK-8s and leptin on colitis. Our results indicate that leptin and CCK have anti-inflammatory effects on acetic acid-induced colitis in rats, which appear to be mediated by capsaicin-sensitive vagal afferent fibers involving the reduction in colonic neutrophil infiltration.     

Conformational preferences in diastereomeric(5S)-methyl-3-(o-aryl)-2,4-oxazolidinediones

The thermally interconvertible diastereomers of the (5S)-methyl-3-(o-aryl)-2,4-oxazolidinediones were synthesized and their conformers studied by (1)H NMR and HPLC. The barriers to rotation about the N-C(aryl) bond were found to be very much solvent dependent. For the o-fluoro oxazolidinedione, difference in barriers to rotation in deuterated methanol and deuterated chloroform amounted to 34 kJ/mol. ortho-Bromo substitution increased the barrier to rotation up to 100 kJ/mol in ethanol, which enabled the analytical separation of the diastereomers and observation of the thermodynamic enrichment of the S-P conformer by HPLC. In CDCl(3) by (1)H NMR, on the other hand, a barrier of only 89 kJ/mol was determined. The S-M and S-P conformers of the diastereomers of o-methyl, alpha-naphthyl and o-iodo derivatives have been assigned by NOESY experiments and the kinetic and thermodynamic constants for the interconversion between the S-M and S-P conformers were determined.     

The effects of streptozotocin-induced diabetes on brucellosis of rats

It is believed that an infection is more common and runs a more protracted course in people with diabetes. In clinical practice, it is important to be aware of these associations, as the prognosis is often dependent upon prompt recognition and appropriate treatment. To show the course of brucellosis in the diabetic state, a model of Brucella melitensis infection was used in the setting of streptozotocin-induced diabetes in rat. B. melitensis infection proceeded more severely in diabetic rats and the severity of diabetes affected the prognosis. However, no association was found between B. melitensis and insulin using in vitro and in vivo experiments. Our study illustrates that B. melitensis infection in diabetes should be taken seriously.     

Gender influence on jejunal migrating motor complex

The role of gender and the menstrual cycle in small bowel motility has not been clearly elucidated. Jejunal motility was recorded with a nasojejunal catheter incorporating five solid-state pressure transducers in ambulatory menstruating women and men of comparable age over 24 h. All women were studied twice, in the early follicular (early-F) and midluteal (mid-L) phases of the menstrual cycle, verified by determining serum levels of gonadal steroids and gonadotropins. The propagation velocity of phase III was slow and the contraction amplitude was high in both menstrual cycle phases compared with men, and these parameters were correlated with serum estrogen levels in the mid-L phase. In the early-F phase, migrating motor complex (MMC) cycle duration during sleep was long compared with other groups and positively correlated with estrogen concentrations, whereas in the mid-L phase MMC cycle duration during sleep was negatively correlated with serum progesterone levels. In all groups, the frequency of phase III contractions was low and the intercontractile interval measured from pressure peak to peak was long during sleep compared with the awake state. Postprandial motility did not display gender difference in any parameter examined. The results demonstrate that the majority of patterns of motility are similar in menstruating women and men, whereas certain aspects of the MMC, most conspicuously propagation velocity and phase III contraction amplitude, differ. We have also documented circadian variation of phase III contraction frequency in both women and men.     

Bombesin improves burn-induced intestinal injury in the rat

This study was designed to determine the effect of exogenous bombesin (10 microg/kg/day, subcutaneously, three times a day) on intestinal hypomotility and neutrophil infiltration in the early and late phases of burn injury (partial-thickness, second-degree burn of the skin). In acute (2 h after burn injury) or chronic (3 days after) burn groups, intestinal transit was delayed, which was reversed by bombesin treatment. In the acute burn group, but not in the chronic group, increased MPO activity was also reduced by bombesin treatment. The results demonstrate that bombesin ameliorates the intestinal inflammation due to burn injury, involving a neutrophil-dependent mechanism.     

Antimicrobial and biological effects of ipemphos and amphos on bacterial and yeast strains

In this study, the antimicrobial effects of monophosphazenes such as SM ipemphos and amphos were examined on bacterial and yeast strains. In addition, the biological effects of these compounds were tested on the lipid level of Saccharomyces cerevisiae and Candida albicans cells. The SM has an antimicrobial effect on the bacterial and yeast strains within the range of 100 and 1500 microg. When the concentration was increased, the inhibition zone expanded on the growth media ( p < 0.01; p < 0.001). The ipemphos did not affect the bacterial and yeast cells in the 100 and 600 microg range. In addition, the amphos did not show an antimicrobial effect on the bacterial cells between 100 and 300 microg or on yeast cells at any of the administered concentrations. In vitro media, the biological effects of these molecules were compared with vitamin E, melatonin and fish oil on the yeast cells. We have found that monophosphazenes have growth effects on the cells in vitro media. The lipid level of S. cerevisiae cells was decreased by 300 microg doses of vitamin E, fish oil, and ipemphos (respectively; p < 0.05, p < 0.01, and p < 0. 001). In addition, the lipid levels of the same yeast cells were depressed by 1000-microg doses in all supplemented groups. However, it was observed that the highest decrease in lipid level of S. cerevisiae cells occurred in the amphos group ( p < 0.001). The lipid levels of the C. albicans cells were significantly reduced ( p < 0.01) by 300 microg of amphos and melatonin. In contrast, the vitamin E and fish oil significantly raised ( p < 0.01; p < 0.001) the lipid level of the same yeast cell, as compared with the control. In addition, the lipid level of these cells was increased by administration of 1000 microg vitamin E, and melatonin ( p < 0.01). In conclusion, while high concentrations of ipemphos and amphos have an antimicrobial effect on bacterial and yeast cells, amphos did not affect the yeast cells. While ipemphos and amphos increased cell growth in media, they reduced the lipid level of C. albicans and S. cerevisiae. In addition, the antioxidants such as vitamin E, melatonin, and fish oils affected the lipid level of yeast cells.     

Turkish honeybees: genetic variation and evidence for a fourth lineage of Apis mellifera mtDNA

The mtDNA of bees from 84 colonies of Turkish honeybees (Apis mellifera) was surveyed for variation at four diagnostic restriction sites and the sequence of a noncoding intergenic region. These colonies came from 16 locations, ranging from European Turkey and the western Mediterranean coast to the Caucasus Mountains along the Georgian border, the eastern Lake Van region, and the extreme south. Combined restriction site and sequence data revealed four haplotypes. Three haplotypes belonged to the eastern Mediterranean mtDNA lineage. The fourth haplotype, which had a novel restriction site pattern and noncoding sequence, was found in samples from the extreme south, near the Syrian border. We found two different noncoding sequences among the eastern Mediterranean haplotypes. The "Caucasian" sequence matches that described from A. m. caucasica, and the "Anatolian" sequence matches that of A. m. carnica. The frequency of the "Caucasian" sequence was highest (98-100%) in sites near the Georgian border and decreased steeply to the south and west. Elsewhere the Anatolian sequence was found. In European Turkey (Thrace) a restriction site polymorphism previously reported from A. m. carnica in Austria and the Balkans was present at high frequency. A novel mtDNA haplotype with a unique restriction site pattern and noncoding sequence was found among bees from Hatay, in the extreme south near the Syrian border. This haplotype differed from the three previously known lineages of honeybee mtDNA--African, western European, and eastern Mediterranean-and may represent a fourth mitochondrial lineage.