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The present study evaluated the beneficial effect of diosmectite–zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P< 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P< 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P< 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P< 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P< 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite–zinc oxide composite supplementation also increased (P< 0.05) TGF-β1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid–induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway.

A total of 144 piglets (Duroc × Landrace × Yorkshire; average initial weight of 6.13 kg weaned at 21 ± 1 d age) were allotted to 4 treatments for 2 wk, each of which had 6 pens with 6 pigs per pen. After the feeding experiment, 6 pigs per treatment were slaughtered to investigate the effects of cello-oligosaccharide (COS) on intestinal microbiota and epithelial barrier function. The COS was added to the basal diet at 0, 1.5, 3.0, and 4.5 g/kg diet at the expense of corn, respectively. Plasma d-lactate, diamine oxidase (DAO), and the Ussing chamber technique were used to determine the intestinal barrier function. 16S rRNA-based methods were used for intestinal microbiota analysis. The results showed that incremental levels of COS had no effect (P> 0.05) on growth performance. Incremental levels of COS increased lactobacilli in jejunal and colonic contents (P< 0.05); decreased Streptococcus suisin jejunal contents (P< 0.05) and S. suisand Escherichia coliin colonic contents (P< 0.05); reduced plasma DAO (linear, P= 0.013, and quadratic, P= 0.037); increased jejunal mucosa DAO (linear, P= 0.003, and quadratic, P= 0.008); decreased fluorescein isothiocyanate dextran 4 kDa flux of jejunum and colon (P< 0.05); and increased transepithelial electrical resistance (TER) in colon (P< 0.05), claudin-1 protein expression in jejunal mucosa (linear, P= 0.001, and quadratic, P= 0.003), and protein expressions of claudin-1 and zonula occludens-1 (ZO-1) in colonic mucosa linearly (P= 0.001 and P= 0.001, respectively) and quadratically (P= 0.001 and P= 0.002, respectively). The results indicated that the improved microbial ecosystem in the presence of COS might contribute to improvement in intestinal barrier function and tight junction proteins. Results also showed that the appropriate dietary COS supplementation level was 3.0 g/kg in weaned pig diets under our trial conditions.

Intrathecally (i.t.) administered corticotropin-releasing factor (CRF) has been shown to produce antinociception in the mouse abdominal stretching (writhing) assay. It also has been demonstrated that spinal kappa opioid receptors as well as CRF receptors are involved in the antinociception induced by CRF. In the present study, the role of CRF i.t. in modulating nociception was assessed further using the mouse tail-flick test. In addition, the modulatory effect of i.t. administered CRF on the antinociceptive activity of morphine was studied. Despite its potent and long-lasting antinociceptive effect in the writhing assay, CRF injected i.t. produced no consistent antinociception in the tail-flick test at doses up to 20 times the antinociceptive ED50 of CRF in the writhing test. In contrast, i.t. injection of CRF significantly attenuated the antinociceptive action of s.c. administered morphine. CRF at doses of 0.1 and 0.2 nmol/mouse i.t. increased the antinociceptive ED50 of s.c. morphine by 2- and 4-fold, respectively. The antagonistic action of CRF peaked between 15 min and 1 hr after i.t. injection and was still observable 4 hr after injection, demonstrating a time course similar to that of the antinociceptive effect of CRF in the writhing test. Intrathecal injection of alpha-helical CRF(9-41), a competitive CRF receptor antagonist, was able to inhibit, in a dose-dependent manner, the antagonistic activity of CRF. The antagonistic action of CRF also was attenuated dose-dependently by i.t. injection of nor-binaltorphimine (nor-BNI), a highly selective kappa opioid receptor antagonist. However, intrathecal injection of (+)-1-nor-BNI, an inactive enantiomer of nor-BNI, did not affect the antagonistic action of CRF. These data suggest that spinal kappa opioid receptors as well as CRF receptors are involved in the antagonistic effect of CRF against morphine antinociception.

Lys192 in the third transmembrane domain of the human CB1 cannabinoid receptor was converted to an alanine to study its role in receptor recognition and activation by agonists. HU-210, CP-55940, WIN55212-2, and anandamide, four cannabinoid agonists with distinct chemical structures, were used to characterize the wild-type and the mutant receptors. In human embryonal kidney 293 cells stably expressing the wild-type receptor, specific binding to [3H]WIN55212-2 and inhibition of cAMP accumulation by cannabinoid agonists were demonstrated, with different ligands exhibiting the expected rank orders of potency and stereoselectivity in competition binding and functional assays. In cells expressing the mutant receptor, the binding affinity of the receptor for [3H]WIN55212-2 was only slightly affected (the Kd for the mutant receptor was twice that of the wild-type), and the ability of WIN55212-2 to inhibit cAMP accumulation was unchanged. However, HU-210, CP-55940, and anandamide were unable to compete for [3H]WIN55212-2 binding to the mutant receptor. In addition, the potencies of HU-210, CP-55940, and anandamide in inhibiting cAMP accumulation were reduced by > 100-fold. These results demonstrate that Lys192 is critical for receptor binding by HU-210, CP-55940, and anandamide. Because Lys192 is not important for receptor binding and activation by WIN55212-2, WIN55212-2 must interact with the cannabinoid receptor through at least one point of interaction that is distinct from those of the three other agonists.

A novel multiplexing scheme for dense holographic storage in photorefractive crystals, spatioangular multiplexing, is described in detail. Compared with spatial multiplexing, spatioangular multiplexing increases the storage capacity by fully utilizing the volume of the storage medium. On the other hand, spatioangular multiplexing reduces the number of holograms overlapping any one hologram in a given volume and so increases the diffraction efficiency achievable as compared with angular multiplexing. Using this scheme, we succeeded in storing 756 high-resolution patterns in an Fe:LiNbO_3 crystal of volume 1 cm^3, with an average diffraction efficiency of 0.5%. This large database is designed for practical use in a novel associative-memory system, called a high-order feedback neural network.

Corticotropin-releasing factor (CRF), a putative stress transmitter, in previous studies failed to show any antinociceptive effect after central intracerebroventricular administration. In this study, a possible role of intrathecally (i.t.) administered CRF in modulating nociception and the involvement of opioid receptors were examined. CRF (i.t.) produced a dose-dependent antinociceptive effect in the mouse abdominal stretching (writhing) assay, with an ED50 of 22.1 (18.9-25.8) pmol/mouse. This antinociceptive effect of CRF peaked from 10 min to 1 hr after i.t. administration, although a significant antinociceptive effect was still observable 4 hr after injection. The dose-response curve of CRF antinociception was shifted to the right by i.t. administered alpha-helical CRF (9-41), a CRF antagonist, and the ED50 was raised by 3.7-fold. Naloxone, an opioid antagonist, also dose-dependently shifted the antinociceptive dose-response curve of CRF to the right. Naloxone at 1 and 10 mg/kg s.c. increased the ED50 value of CRF by 2- and 4-fold, respectively. In contrast, s.c. injection of 10 mg/kg of (+)-naltrexone, an inactive enantiomer of naltrexone, did not affect significantly the antinociception of i.t. administered CRF. Intrathecal injection of nor-binaltorphimine, a highly selective kappa opioid antagonist, increased the antinociceptive ED50 of CRF by 5.6-fold. However, the antinociceptive activity of CRF (i.t.) was not significantly affected by either beta-funaltrexamine, an irreversible mu selective opioid antagonist, or naltrindole, a highly selective delta opioid antagonist. Furthermore, the antinociceptive ED50 of CRF was not altered by (+)-1-nor-binaltorphimine, an inactive enantiomer of nor-binaltorphimine.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of the guinea pig ileum (GPI) and mouse vas deferens (MVD) to quantify opiate tolerance and physical dependence in the same preparation was examined. In the GPI, tolerance to and physical dependence on various opiates were induced by direct incubation with an agonist and tolerance and abstinence were assessed after its rapid removal by extensive washing. Dependence, as evidenced by an increase in twitch height and after removal of the agonist as compared to that before incubation, provided an index of the degree of physical dependence. The extent of the supersensitive response after agonist removal was noted to be related directly to the agonist concentration and the degree of tolerance development. Furthermore, the supersensitive response was found to be stereospecific, naloxone reversible and preferentially mu receptor-mediated. Likewise, tolerance to opiates could be demonstrated in the MVD by direct incubation with an agonist. Unlike the GPI, rapid removal of the agonist by washing did not produce a supersensitive response to electrical stimulation. However, a supersensitive response was demonstrable in the presence of naloxone. Thus, after a tolerant/dependent state was induced by incubation of the vas with a predetermined dose of [D-Ala2, D-Leu5]enkephalin that completely abolished the twitch response, the subsequent addition of naloxone resulted in a supersensitive response to electrical stimulation that was concentration-dependent. The maximum twitch response in the presence of naloxone, compared to that obtained before incubation with the agonist, provided an index of the extent of dependence.(ABSTRACT TRUNCATED AT 250 WORDS)