Nivalenol-induced apoptosis in thymus, spleen and Peyer''s patches of mice

ICR:CD-1 male mice were orally administered with Nivalenol(NIV) at the dose levels of 5, 10 and 15 mg/kg body weight, and examined at 12, 24 and 48 hours after inoculation (HAI), respectively, to elucidate the process of development of apoptosis in the thymus, spleen and Peyer's patch. There were no signs of clinical disorders and no changes in body and organ weights until 48 HAI except for that the thymus weight significantly decreased at 48 HAI. Immunohistochemically, the number of apoptotic lymphocytes evaluated by in situ detection for fragmented DNA showed a dose-dependent increase at 12 HAI in both the thymus and the Peyer's patch, while it became to increase at 24 HAI in the spleen. Dead lymphocytes in the thymus, spleen and Peyer's patch showed ultrastructural characteristics of apoptosis. Moreover, the DNA ladder was first detected by agarose gel electrophoresis at 12 HAI in the thymus of 15 mg/kg-group. The results clearly indicate that NIV is able to induce apoptosis in the lymphoid tissues of mice.     

Effects of temperature increase on the propagation of presynaptic action potentials in the pathway between the Schaffer collaterals and hippocampal CA1 neurons

Effects of temperature increase on the neuronal activity of hippocampal CA2-CA1 regions were examined by using optical and electrophysiological recording techniques. Stimulation of the Schaffer collaterals at the CA2 region evoked depolarizing optical signals that spread toward the CA1 region at 32 degrees C. The optical signal recorded by 49 pixels was characterized by fast and slow components that were closely related to presynaptic action potentials and excitatory postsynaptic responses, respectively. The optical signal was depressed by temperature increase to 38-40 degrees C. The temperature increase to 38 degrees C produced a hyperpolarization and a depression of the excitatory postsynaptic potential (EPSP) in single hippocampal CA1 pyramidal neurons. The depression of the neuronal activity induced by temperature increase was attenuated by application of glucose (22 mM) or pyruvate (22 mM). Adenosine (200 microM) did not block the presynaptic action potential but strongly depressed the excitatory postsynaptic response. 8-Cyclopentyl-1,3-dimethylxanthine (8-CPT) (10 microM), an antagonist for adenosine A(1) receptors, attenuated the depression of the excitatory postsynaptic response but not the inhibition of the presynaptic action potential at 38 degrees C. These results suggest that adenosine mediates the high-temperature-induced depression of the excitatory synaptic transmission but not that of action potential propagation in rat CA1 neurons.     

Dietary bile acids inhibit potentially elemental diet-induced small intestinal atrophy in rats

The mechanism responsible for elemental diet (ED)-induced small intestinal atrophy is still unknown. However, it is possible that bile acids in the gut lumen influence this process. The aim of this study was to evaluate the effects of oral bile acid administration during ED feeding. Specific pathogen-free male Sprague-Dawley rats, 10 weeks old, were fed an ED only, ED plus 0.1% (w/w) hyocholic acid, or ED plus 0.1% (w/w) hyodeoxycholic acid ad libitum for 4 weeks. The control rats were fed standard chow ad libitum for 4 weeks. After 4 weeks, the wet weight and whole length of the small intestine, and the mucosal diamine oxidase (DAO) and alkaline phosphatase (ALP) activities were measured. Microscopic histological observation was also performed. ED feeding induced atrophy and elevations in the mucosal DAO and ALP activities in the small intestine. Hyocholic acid and hyodeoxycholic acid administration both tended to inhibit these alterations. In conclusion, ED feeding induced atrophy and elevations in the mucosal DAO and ALP activities in the small intestine. Oral bile acid administration may prevent this atrophy and the elevations in mucosal DAO and ALP activities, which may lead to new therapeutic strategies in patients managed with ED.     

A randomized controlled trial comparing water exchange and air insufflation during colonoscopy without sedation

Objectives

Previous studies have shown that water exchange is superior to air insufflation in attenuating insertion pain during colonoscopy. We conducted a randomized controlled trial with head-to-head comparison of these methods to assess their effectiveness in colonoscopy without sedation.

Methods

A total of 447 outpatients were randomized to either water exchange (WE) or the standard air (CO₂) insufflation (AI). The primary outcome was the improvement of patient intraprocedural pain (pain score), evaluated using a questionnaire (scores 1 to 5).

Results

After exclusion of 44 patients from further analysis, 403 patients were analyzed. There was no difference in clinical background between the WE and AI groups. Patients in the WE group reported less intraprocedural pain than those in the AI group (2.17?±?1.06 vs. 2.42?±?1.03; unpaired t test, p?=?0.021). We divided the cases into two groups, more or less painful colonoscopy, based on age, body mass index, use of anti-peristaltic drugs or not, and physician’s experience. In less painful colonoscopy, the WE method could reduce pain effectively but its effect was limited in the more painful group.

Conclusion

WE is superior to AI for attenuating insertion pain during colonoscopy without sedation, but its efficacy is limited in more painful endoscopy.

     

Immunohistochemical demonstration of inducible nitric oxide and nuclear factor-kappa B with reference to age-related changes in the mouse spiral and vestibular ganglion

The morphology and immunohistochemistry of inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-kappa B) were studied on the spiral and vestibular ganglion of young and old ddy mice. The significant decrease in the number of the spiral ganglion cells and a significant expression of iNOS and NF-kappa B were observed in old mice. In contrast, in the vestibular ganglion of all animals examined, decrease in the number of the ganglion cells or expression of iNOS and NF-kappa B were not observed. Although the relevance of enzymatic systems for the protection of vestibular ganglion cells in old individuals from harmful oxidative stress increased with aging should be further clarified, lack of harmful stress due to nitric oxide (NO) may be one of the plausible reasons for that the vestibular ganglion cells were not decreased in number with aging, since iNOS was not detected in the vestibular ganglion cells in the animals tested in the present study.     

Influencing factors on occurrence and relapse in ulcerative colitis

The concordance rate of monozygotic twins showed that the occurrence of ulcerative colitis required both internal and environmental conditions. Genetic studies revealed that IBD1 locus on chromosome 16 and IBD2 locus on chromosome 12 showed highly suspicious susceptibility for inflammatory bowel disease. The other possible internal factors include antineutrophil cytoplasmic antibodies and mucin abnormality. Many environmental factors have been reported to cause relapse. These are viral and bacterial infection, medicine such as antibiotics, non-steroidal anti-inflammatory drugs and aminosalicylates, colonic ischemia, post-examination state, psychological stress, winter season, travel and overwork.