Protective effect of microinjection of glutamate into hypothalamus paraventricular nucleus on chronic visceral hypersensitivity in rats.

Chronic visceral hypersensitivity (CVH) is a major pathophysiological feature of patients experiencing in irritable bowel syndrome (IBS) and other disorders with visceral pain. However, little is known about its regulation of the central nucleus. In this research, we investigated the protective effect of microinjection of glutamate into hypothalamus paraventricular nucleus (PVN) on CVH and its possible regulatory mechanism in rats. Visceral sensitivity was assessed by pain threshold, abdominal withdrawal reflex (AWR) score, and the abdominal external oblique muscle electromyography (EMG) amplitude. Pathological changes in colorectal mucosa were assessed using immunohistochemical, biochemical analysis and Western blot. Results showed that microinjection of different doses of glutamate into PVN reduced the visceral sensitivity in a dose-dependent manner. This effect can be reversed after chemical ablation of PVN or nucleus tractus solitarius (NTS) or pretreatment with the arginine vasopressin (AVP)-V1 receptor antagonist ([Deamino-pen1,val4,D-Arg8]-vasopressin) DPVDAV into NTS. The vagus discharge frequency was significantly reduced after the glutamate microinjection into PVN. Additionally, oxidation, proliferation and apoptosis in colorectal mucosa were related to the CVH regulations. These findings suggested that PVN and NTS are involved in the regulatory process of CVH and exert the protective effect on CVH, providing new ideas and therapeutic targets for CVH research.

Role of gastroscopic biopsy of gastric ulcer margins and healed sites in the diagnosis of early gastric cancer: A clinical controlled study of 513 cases.

The present case study aimed to evaluate the effect of gastroscopic biopsy of gastric ulcer margins and healed sites in the diagnosis of early gastric cancer. A total of 513 patients who were diagnosed with gastric ulcers using gastroscopy between January 1999 and December 2013 were included in the present study and were divided into either the experimental or the control group. In the control group, samples were only taken from the ulcer margin, whereas in the experimental group samples were taken from the ulcer margin and from the ulcer base. In the experimental group, a routine biopsy of the ulcer margin was performed on first examination, and recheck by gastroscopy was performed from the second week. For ulcers that remained unhealed, a biopsy of the ulcer margin was subsequently conducted; however, for healed or almost healed ulcers, a biopsy of the ulcer base was conducted. The duration of follow-up by gastroscopy ranged between 1 week and 24 months. For the control group, a biopsy of the ulcer margin was conducted using the conventional method. The detection rate of the experimental group was 3.88% (9/232), with 4 cases of gastric cancer confirmed from examinations of the ulcer base. The detection rate of the control group was 1.07% (3/281), which was significantly decreased compared with that of the experimental group (P=0.0345). Overall, patients who underwent regular follow-up gastroscopy following treatment exhibited a markedly increased detection rate of early gastric cancer, suggesting that early cancer may occur in healed gastric ulcer sites.

Clinical guidelines of non-alcoholic fatty liver disease: A systematic review.

AIM: To perform a systematic review to grade guidelines and present recommendations for clinical management of non-alcoholic fatty liver disease (NAFLD). METHODS: A database search was conducted on PubMed for guidelines published before May 2016, supplemented by reviewing relevant websites. The Appraisal of Guidelines for Research and Evaluation (ARGEE) Instrument II was a tool designed to appraise the methodological rigor and transparency in which a clinical guideline is developed and it is used internationally. It was used to appraise the quality of guidelines in this study. The inclusion criteria include: clinical NAFLD guidelines for adults, published in English, and released by governmental agencies or key organizations. RESULTS: Eleven guidelines were included in this study. Since 2007, guidelines have been released in Asia (3 in China, 1 in South Korea, and 1 in Japan), Europe (1 in Italy), America (1 in United States and 1 in Chile) and three international agencies [European associations joint, Asia-Pacific Working Party and World Gastroenterology Organization (WGO)]. Using the ARGEE II instrument, we found US 2012 and Europe 2016 had the highest scores, especially in the areas of rigor of development and applicability. Additionally, Italy 2010 and Korea 2013 also presented comprehensive content, rigorous procedures and good applicability. And WGO 2014 offered various algorithms for clinical practice. Lastly, a practical algorithm for the clinical management was developed, based on the recommended guidelines. CONCLUSION: This is the first systematic review of NAFLD guidelines. It may yield insights for physicians and policy-makers in the development and application of guidelines.

Protective effect of histamine microinjected into cerebellar fastigial nucleus on stress gastric mucosal damage in rats.

In the study, we investigated the effect of histamine microinjected into cerebellar fastigial nucleus (FN) on stress gastric mucosal damage (SGMD), and its mechanisms in rats. The model of SGMD was established by restraining and water (21±1°C)-immersion for 3h. The gastric mucosal damage index (GMDI) indicated the severity of gastric mucosal damage. Histamine or receptor antagonist was microinjected into the FN. The decussation of superior cerebellar peduncle (DSCP) and the lateral hypothalamic area (LHA) were destroyed, respectively. The pathological changes of gastric mucosa were evaluated using biological signal acquisition system, Laser-Doppler flowmeter, and western blotting. We found that the microinjection of histamine (0.05, 0.5, and 5µg) into FN significantly attenuated the SGMD, in a dose-dependent manner, whereas, the microinjection of histamine H2 receptor antagonist, ranitidine, and glutamic acid decarboxylase antagonist, 3-mercaptopropionic acid (3-MPA) exacerbated the SGMD. The protective effect of histamine on SGMD was abolished by electrical lesion of DSCP or chemical ablation of LHA. The microinjection of histamine decreased the discharge frequency of the greater splanchnic nerve, and the gastric mucosal blood flow was increased. In addition, the cellular proliferation was enhanced, but the cellular apoptosis was reduced in the gastric mucosa. Also the pro-apoptosis protein, Bax, and caspase-3 were down-regulated, and the anti-apoptosis protein, Bcl-2 was up-regulated following microinjection of histamine. In conclusion, the FN participated in the regulation of SGMD after histamine microinjected into FN, and cerebellar-hypothalamic circuits (include: DSCP, LHA) contribute to the process, which may provide a new therapeutic strategy for SGMD.

Glutamate microinjection into the hypothalamic paraventricular nucleus attenuates ulcerative colitis in rats.

AIM: To investigate the effects of glutamate microinjection into hypothalamic paraventricular nucleus (PVN) on ulcerative colitis (UC) in rats and to explore the relevant mechanisms. METHODS: 2,4,6-Trinitrobenzenesulfonic acid (100 mg/kg in 50% ethanol) was instilled into the colon of adult male SD rats to induce UC. A colonic damage score (CDS) was used to indicate the severity of the colonic mucosal damage. The pathological changes in the colonic mucosa were evaluated using immunohistochemistry, Western blotting, biochemical analyses or ELISA. Ten minutes before UC induction, drugs were microinjected into the relevant nuclei in rat brain to produce chemical stimulation or chemical lesion. RESULTS: Microinjection of glutamate (3, 6 and 12 µg) into the PVN dose-dependently decreased the CDS in UC rats. This protective effect was eliminated after kainic acid (0.3 µg) was microinjected into PVN or into the nucleus tractus solitarius (NTS) that caused chemical lesion of these nuclei. This protective effect was also prevented when the AVP-V1 receptor antagonist DPVDAV (200 ng) was microinjected into the NTS. The discharge frequency of the vagus was markedly decreased following microinjection of glutamate into the PVN. Microinjection of glutamate into the PVN in UC rats significantly increased the cell proliferation and anti-oxidant levels, and decreased the apoptosis and Bax and caspase 3 expression levels and reduced the pro-inflammatory factors in the colonic mucosa. CONCLUSION: The activation of hypothalamic PVN exerts protective effects against UC, which is mediated by the NTS and vagus. The effects may be achieved via anti-oxidative, anti-apoptotic, and anti-inflammatory factors.

Enhancement effect of dihydroartemisinin on human γδ T cell proliferation and killing pancreatic cancer cells.

γδ T cells play important roles in innate immunity against tumors and infections. Inhibitory effect of dihydroartemisinin on growth of cancer cells has been found in recent years. In this study, we investigated the effect of dihydroartemisinin on human γδ T cell proliferation by MTT assay and killing activity against pancreatic cancer cells SW1990, BxPC-3 and PANC-1 by LDH release assay in vitro. Intracellular molecule alterations were verified by flow cytometry. The results suggested that appropriate concentration of dihydroartemisinin favored the expansion of γδ T cells and enhanced γδ T cell mediated killing activity against pancreatic cancer cells. Up-regulation of intracellular perforin, granzyme B expression and IFN-γ production may be the important mechanism of dihydroartemisinin on increased antitumor activity of γδ T cells.

[Lentivirus-mediated gene transfer of human sTRAIL induced apoptosis in SGC-7901 cells].

OBJECTIVE: To construct self-inactivating (SIN) lentiviral vector carrying human soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL) gene and to observe the effects of sTRAIL gene on apoptosis in SGC-7901 cells, so as to assess the value of sTRAIL in gene therapy for gastric cancer. METHODS: The bicistronic SIN lentiviral transfer plasmid containing sTRAIL gene and internal ribosomal entry site-green fluorescent protein gene (IRES-GFP) was constructed. Recombinant lentivirus containing sTRAIL were packaged using liposome by lentiviral packing system. Several cell lines including HL-7702, HLF-1 and SGC-7901 cells were infected with the viral supernatant. Flow cytometry was used to measure apoptosis of cells and recombinant sTRAIL. protein was assayed by ELISA at 24 h after infection. RESULTS: The lentiviral transfer plasmid pXZ208-sTRAIL was constructed, and the virus titres were above 10(6) IU/mL in the supernatant. SGC-7901 cells were efficiently infected by recombinant virus. The apoptosis rate of SGC-7901 cells was increased with the virus multiplicity of infection (MOI) increasing. When the MOI was > or = 0.5, a dose-dependent apoptosis rate was observed. At MOI of 6.0, the highest apoptosis rate (29.12 +/- 2.87)% was observed, while the expression of sTRAIL in the supernatant was only (34.08 +/- 3.43) ng/mL. However, no significant apoptosis was observed in HL-7702 cells and HLF-1 cells. CONCLUSION: Recombinant lentivirus carrying human sTRAIL gene can efficiently infected SGC-7901 cells, which induced apoptosis in SGC-7901 cells in vitro by secreting bioactive sTRAIL protein. However, this effect is not seen in normal cells.

Abnormal expression of Toll-like receptor 4 is associated with susceptibility to ethanol-induced gastric mucosal injury in mice.

BACKGROUND AND AIMS: Toll-like receptor 4 (TLR4) contributes to ethanol-induced gastric mucosal injury. This study aimed to determine its precise role in this pathogenic state and the related signaling pathway. METHODS: Ethanol-induced gastric mucosal injury models were generated in TLR4(-/-) mice (C3H/HeJ: point mutation; C57BL/10ScNJ: gene deletion), their respective TLR4(+/+) wild-type counterparts, and heterozygous TLR4(+/-) mice. Lipopolysaccharide (LPS) or pyrrolidine dithiocarbamate (PDTC) was injected intraperitoneally 1 h or 30 min before ethanol administration. At 1 h post-ethanol treatment, gastric or serum specimens were evaluated. RESULTS: Ethanol intra-gastric administration induced significant gastric mucosal injury in all mice, but the damaged area was larger in TLR4(-/-) mice. LPS preconditioning and up-regulated TLR4 expression led to significantly larger areas of gastric mucosal damage. Upon ethanol administration, TLR4(+/+), and not TLR4(-/-), mice showed significant increases in TLR4, myeloid differentiation factor 88 (MyD88), cytoplasmic high mobility group box 1 (HMGB1), and nuclear factor-kappa B p65 (NF-κB p65). PDTC pretreatment significantly attenuated the ethanol-induced gastric mucosal damaged areas, inhibited nuclear NF-κB p65 expression, and suppressed HMGB1 translocation out of the nucleus. In addition, PDTC pretreatment reduced ethanol-stimulated expression of the inflammatory modulators, interleukin-1ß (IL-1ß) and tumor necrosis factor-alpha (TNF-α), in serum. CONCLUSIONS: Both deficient and excessive expression of TLR4 promotes ethanol-induced gastric mucosal injury. The underlying mechanism involves the MyD88/NF-κB signaling pathway and the HMGB1, TLR4 activator ligand. The increased expression of HMGB1 may lead to increased secretion and binding to TLR4, further stimulating the TLR4/MyD88/NF-κB signaling pathway and aggravating the ethanol-induced gastric mucosal injury.

Propofol inhibits hypoxia/reoxygenation-induced human gastric epithelial cell injury by suppressing the Toll-like receptor 4 pathway.

This study aimed to investigate the role of the Toll-like receptor 4 (TLR4) pathway in normal human gastric epithelial (GES-1) cells under hypoxia/reoxygenation (H/R) in vitro, and the effect of propofol on injured GES-1 cells as well as its possible mechanism. Before H/R induction, GES-1 cells were preconditioned with fat emulsion, propofol, or epigallocatechin gallate. Then cell viability, cell apoptosis, and related molecules in the cells were analyzed under experimental conditions. We found that propofol 50 µmol/L markedly inhibited the H/R injury under hypoxia 1.5 h/reoxygenation 2 hours by promoting GES-1 cell viability and decreasing cell apoptosis. The TLR4 signal may be involved in the protective effect of propofol against H/R injury. The malondialdehyde contents and superoxide dismutase activities were recovered under propofol preconditioning. In summary, propofol preconditioning may exert a protective effect on H/R injury in GES-1 cells and the mechanism may be via inhibition of the activated TLR4 signal under H/R conditions.

The enhanced effect of lupeol on the destruction of gastric cancer cells by NK cells.

Lupeol, a triterpene, was reported to possess beneficial effects as a therapeutic and preventive agent for a range of disorders. Many studies have confirmed that lupeol possesses strong activities such as antioxidative, antiinflammatory, antiarthritic, antimutagenic, and antimalarial, both in vitro and in vivo, and at its effective therapeutic doses exhibit no toxicity to normal cells and tissues. Lupeol was observed to inhibit the proliferation of gastric tumour cells in a dose-dependent manner, as assessed by MTT assay, and induce the proliferation of NK cells, as assessed by flow cytometry and Western blotting. The killing effect of NK cells on gastric tumour cells was assessed by LDH. Our experiment demonstrated that lupeol at appropriate concentrations could promote the proliferation of NK cells, inhibit the proliferation of gastric cancer cell lines BGC823, N87 and HGC27, and increase the killing effect of NK cells on gastric cancer cells. We speculated that lupeol might increase the expression of PFP, IFN-γ, and CD107a via the activation of PI3K/Akt and Wnt/ß-catenin signalling pathways. Lupeol could serve as a potential agent against gastric cancer; however, further in-depth in vivo studies are still required.

Propofol participates in gastric mucosal protection through inhibiting the toll-like receptor-4/nuclear factor kappa-B signaling pathway.

AIMS: Propofol has demonstrated protective effects against digestive injury. Toll-like receptor-4 (TLR4) is involved in gastric mucosal injury. However, it has not yet been clarified whether propofol protects gastric mucosa from ethanol-induced injury and whether the mechanism involved is related to TLR4 activation. Therefore, this prospective study was carried out to address the issue. METHODS: Gastric mucosal injury was induced in mice by intragastric administration of ethanol. Propofol was given intraperitoneally 30 min before ethanol intragastric administration and, 1h later, gastric specimens were studied using hematoxylin--eosin staining, quantitative real-time RT-PCR, immunohistochemical staining and Western blot assays; serum specimens were studied using ELISA kits. RESULTS: Propofol at 25mg/kg significantly attenuated ethanol-induced gastric mucosal injury. In addition, propofol pretreatment significantly inhibited the upregulated expression of high-mobility group box-1 (HMGB1) protein, TLR4 and its downstream signaling molecules--myeloid differentiation factor 88 (MyD88) and nuclear factor kappa-B (NF-κB)--in gastric mucosa, while suppressing the increased release of tumor neurosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in serum. Furthermore, upregulation of the Bax/Bcl-2 ratio in gastric mucosa was clearly depressed by propofol. CONCLUSION: Propofol can inhibit HMGB1 expression and TLR4/MyD88/NF-κB-mediated inflammatory responses, and hamper apoptosis, which may contribute to its protective action against ethanol-induced gastric mucosal injury.

The effect of phloretin on human γδ T cells killing colon cancer SW-1116 cells.

OBJECTIVE: To explore the effect and mechanism of Phloretin on human γδ T cells killing colon cancer SW-1116 cells. METHODS: γδ T cells were amplified in vitro from human peripheral blood mononuclear cells through isopentenyl pyrophosphate method (IPP). After cocultured different concentrations of Phloretin with γδ T cells or SW-1116 cells for 48h respectively, MTT assay was used to test the growth curve of these two cells; Flow cytometry to test the expression of Granzyme B (GraB), perforin (PFP), CD107a and IFN-γ of γδ T cells; Lactate dehydrogenase (LDH) release assay to test the cytotoxic activity of the γδ T cells on SW-1116 cells; and Western blot to test the Wnt3a expression of the γδ T cells. RESULTS: After cultured with IPP for ten days, the percentage of γδ T cells increased from 3.31±3.00% to 78.40±10.30%. Compared to the control group, when the concentration of Phloretin increased from 2.35µg/ml to 18.75µg/ml, it could significantly proliferate the γδ T cell growth (P<0.05) and inhibit the growth of SW-1116 cells in dose-response, and the expression of GraB, PFP, CD107a and Wnt3a significantly increased (P<0.05). Significant positive relationships were observed among CD107a and PFP, GraB, cytotoxicity (P<0.05). The percentage of IFN-γ producing γδ T cells treated with Phloretin was significantly higher than control group. CONCLUSION: Phloretin can enhance the killing effect of γδ T cells on SW-1116 cells; the mechanism may be that Phloretin could proliferate the γδ T cell growth, increase the expression of PFP and GraB, activate the Wnt signaling pathway, and produce higher level of IFN-γ. Indeed CD107a expression probably correlates quite well with antitumor activity.

Muscimol microinjection into cerebellar fastigial nucleus exacerbates stress-induced gastric mucosal damage in rats.

AIM: To investigate the effects of microinjection of the GABA(A) receptor agonist muscimol into cerebellar fastigial nucleus (FN) on stress-induced gastric mucosal damage and the underlying mechanism in rats. METHODS: Stress-induced gastric mucosal damage was induced in adult male SD rats by restraining and immersing them in cold water for 3 h. GABA(A) receptor agonist or antagonist was microinjected into the lateral FN. The decussation of superior cerebellar peduncle (DSCP) was electrically destroyed and the lateral hypothalamic area (LHA) was chemically ablated by microinjection of kainic acid. The pathological changes in the gastric mucosa were evaluated using TUNEL staining, immunohistochemistry staining and Western blotting. RESULTS: Microinjection of muscimol (1.25, 2.5, and 5.0 µg) into FN significantly exacerbated the stress-induced gastric mucosal damage in a dose-dependent manner, whereas microinjection of GABA(A) receptor antagonist bicuculline attenuated the damage. The intensifying effect of muscimol on gastric mucosal damage was abolished by electrical lesion of DSCP or chemical ablation of LHA performed 3 d before microinjection of muscimol. Microinjection of muscimol markedly increased the discharge frequency of the greater splanchnic nerve, significantly increased the gastric acid volume and acidity, and further reduced the gastric mucosal blood flow. In the gastric mucosa, further reduced proliferation cells, enhanced apoptosis, and decreased anti-oxidant levels were observed following microinjection of muscimol. CONCLUSION: Cerebellar FN participates in the regulation of stress-induced gastric mucosal damage, and cerebello-hypothalamic circuits contribute to the process.

Protection of ghrelin postconditioning on hypoxia/reoxygenation in gastric epithelial cells.

AIM: To investigate the protective effect and mechanisms of ghrelin postconditioning against hypoxia/reoxygenation (H/R)-induced injury in human gastric epithelial cells. METHODS: The model of H/R injury was established in gastric epithelial cell line (GES-1) human gastric epithelial cells. Cells were divided into seven groups: normal control group (N); H/R postconditioning group; DMSO postconditioning group (DM); ghrelin postconditioning group (GH); D-Lys3-GHRP-6 + ghrelin postconditioning group (D + GH); capsazepine + ghrelin postconditioning group (C + GH); and LY294002 + ghrelin postconditioning group (L + GH). 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to detect GES-1 cell viability. Hoechst 33258 fluorochrome staining and flow cytometry were conducted to determine apoptosis of GES-1 cells. Spectrophotometry was performed to determine release of lactate dehydrogenate (LDH). Protein expression of Bcl-2, Bax, Akt, and glycogen synthase kinase (GSK)-3ß was determined by western blotting. Expression of vanilloid receptor subtype 1 (VR1), Akt and GSK-3ß was observed by immunocytochemistry. RESULTS: Compared with the H/R group, cell viability of the GH group was significantly increased in a dose-dependent manner (55.9% ± 10.0% vs 69.6% ± 9.6%, 71.9% ± 17.4%, and 76.3% ± 13.3%). Compared with the H/R group, the percentage of apoptotic cells in the GH group significantly decreased (12.38% ± 1.51% vs 6.88% ± 0.87%). Compared with the GH group, the percentage of apoptotic cells in the D + GH group, C + GH group and L + GH groups significantly increased (11.70% ± 0.88%, 11.93% ± 0.96%, 10.20% ± 1.05% vs 6.88% ± 0.87%). There were no significant differences in the percentage of apoptotic cells between the H/R and DM groups (12.38% ± 1.51% vs13.00% ± 1.13%). There was a significant decrease in LDH release following ghrelin postconditioning compared with the H/R group (561.58 ± 64.01 U/L vs 1062.45 ± 105.29 U/L). There was a significant increase in LDH release in the D + GH, C + GH and L + GH groups compared with the GH group (816.89 ± 94.87 U/L, 870.95 ± 64.06 U/L, 838.62 ± 118.45 U/L vs 561.58 ± 64.01 U/L). There were no significant differences in LDH release between the H/R and DM groups (1062.45 ± 105.29 U/L vs 1017.65 ± 68.90 U/L). Compared with the H/R group, expression of Bcl-2 and Akt increased in the GH group, whereas expression of Bax and GSK-3ß decreased. Compared with the GH group, expression of Bcl-2 decreased and Bax increased in the D + GH, C + GH and L + GH groups, and Akt decreased and GSK-3ß increased in the L + GH group. The H/R group also upregulated expression of VR1 and GSK-3ß and downregulated Akt. The number of VR1-positive and Akt-positive cells in the GH group significantly increased, whereas the number of GSK-3ß-positive cells significantly decreased. These effects of ghrelin were reversed by capsazepine and LY294002. CONCLUSION: Ghrelin postconditioning protected against H/R-induced injury in human gastric epithelial cells, which indicated that this protection might be associated with GHS-R, VR1 and the PI3K/Akt signaling pathway.

Lateral hypothalamic area mediated the protective effects of microinjection of glutamate into interpositus nucleus on gastric ischemia-reperfusion injury in rats.

We investigated the protective effects of chemical stimulation of cerebellar interpositus nucleus (IN) on gastric ischemia-reperfusion injury (GI-RI) and its possible regulatory mechanisms in rats. Gastric mucosal damage index (GMDI) indicated the severity of gastric mucosal injuries. Transferase dUTP nick end labeling (TUNEL) staining and proliferating cell nuclear antigen (PCNA) were performed to assess gastric mucosal cell apoptosis and proliferation. Microinjection of glutamate into IN markedly attenuated GI-RI. Either chemical lesion of IN or electrical ablation of the decussation of superior cerebellar peduncle (DSCP) obviously aggravated GI-RI. The protective effects of IN were reversed with the pretreatments of microinjection of 3-mercaptopropionic acid into IN or Bicuculline into lateral hypothalamic area (LHA), individually. The discharge frequency and intensity of greater splanchnic nerve (GSN) decreased and gastric mucosal blood flow increased after chemical stimulation of IN. The apoptosis of positive cells of gastric mucosa was decreased by chemical stimulation of IN, whereas proliferation increased. The gastric juice volume, acidity, and total acid output were all decreased after the chemical stimulation of IN. These results indicated that IN participates in regulation of GI-RI and is a specific area in central nervous system for exerting protective effects on GI-RI. DSCP, LHA and GSN may involve in this process. Apoptosis and proliferation may mediate this protective process in rats too.

Lateral hypothalamic area mediated the aggravated effect of microinjection of Baclofen into cerebellar fastigial nucleus on stress gastric mucosal damage in rats.

Cerebellum, primarily believed as a subcortical somatic motor center, is increasingly considered to be implicated in visceral activities. However, little is known about its regulation on gastrointestinal organs. In this research, we investigated the aggravated effect of microinjection of gamma-aminobutyric acid receptor subtype B (GABA(B)R) agonist, Baclofen into cerebellar fastigial nucleus (FN) on stress gastric mucosal damage (SGMD) and its possible regulatory mechanism. The gastric mucosal damage index was chosen to indicate the severity of gastric mucosal injure. Immunohistochemistry and transferase-mediated dUTP-biotin nick-endlabeling (TUNEL) methods were used to detect the variations of lateral hypothalamic area (LHA) and gastric mucosa. It had been demonstrated that FN participates in regulation of SGMD via its GABA(B)R and GABA neural pathway, which passes through the decussation of superior cerebellar peduncle and projects to the GABA receptors in LHA. Meanwhile, celiac sympathetic nerve involves in this process via mediating neural discharge, which results in the decrease of gastric mucosal blood flow. Additionally, apoptosis, proliferation and oxidation in gastric mucosa, and gastric acid contribute in the mechanism. It could be expected that these results might suggest insights to the cerebellar and hypothalamic function, and the treatment of gastrointestinal diseases.

The protective effect of 17beta-estradiol postconditioning against hypoxia/reoxygenation injury in human gastric epithelial cells.

The purpose of this study was to investigate the effects and mechanisms of 17beta-estradiol pharmacological postconditioning on gastric epithelial cells hypoxia/reoxygenation injury by using an in vitro model of human gastric epithelial cells. The model of hypoxia/reoxygenation was established with human gastric epithelial cell line. The gastric epithelial cell viability was detected by 3-(4, 5-dimethylthazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assays. Gastric epithelial cellular apoptosis was determined by Hoechst 33258 fluorochrome staining and flow cytometric analysis. Contents of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured by Colorimetry analysis. The protein expression of Bcl-2 and Bax in different groups was determined by Western blot analyses and immunocytochemistry assay. 17beta-estradiol (10(-8), 10(-7) and 10(-6)mol/l) inhibited hypoxia/reoxygenation injury and 17beta-estradiol (10(-6)mol/l) obviously attenuated hypoxia/reoxygenation injury 3h hypoxia followed by 4h reoxygenation. 17beta-estradiol promoted gastric epithelial cell viability and inhibited the gastric epithelial cell apoptosis, and meanwhile, decreased the MDA content and increased SOD activity. The level of Bcl-2 protein was restored to the normal level by 17beta-estradiol pharmacological postconditioning. In contrast, the Bax protein level was markedly reduced by 17beta-estradiol pharmacological postconditioning. These effects of 17beta-estradiol were inhibited by pretreatment with fulvestrant. These data suggested that 17beta-estradiol seems involved in regulation of gastric hypoxia/reoxygenation injury and gastroprotection, and its protective effects were strongly related to estrogen receptor.

Chemopreventive effects of rofecoxib and folic acid on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

OBJECTIVES: Epidemiological and experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) are chemopreventive agents of gastrointestinal cancers, but few studies on gastric cancer have been carried out. A decrease in folic acid supplement and subsequent DNA hypomethylation are related to gastrointestinal cancers, and it has been shown that high-dose folic acid may interfere with gastric carcinogenesis in dogs. The objective of this study was to investigate the effects of rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, and folic acid on the chemoprevention of gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Wistar rats, and to evaluate the cell proliferation of gastric mucosa in different experimental groups. METHODS: Eighty male Wistar rats were randomly divided into five groups (16 rats in each group). In the control group, the rats were given pure water and basal diet. In the MNNG group, the rats received MNNG in drinking water (100 mg/L) and basal diet. In the MNNG + low-dose rofecoxib group, the rats were given MNNG and rofecoxib 5 mg/kg per day with basal diet. In the MNNG + high-dose rofecoxib group, the rats were given MNNG and rofecoxib 15 mg/kg per day with basal diet. In the MNNG + folic acid group, the rats were given MNNG and folic acid 5 mg/kg per day with basal diet. The experiment was terminated at 50 weeks, and all rats were killed. Blood samples of 3 mL were obtained for measurement of serum folic acid concentrations in the control group, the MNNG group and the MNNG + folic acid group by using chemiluminescent method. The stomach was removed from all rats for histopathological examination and immunohistochemical study. Proliferating cell nuclear antigen (PCNA) expression in gastric epithelial cells was also determined. RESULTS: In the MNNG group, five of 11 rats (45.5%) developed gastric cancer, while in all other four groups no gastric cancer was found (P < 0.05). The positivity rate of PCNA expression in the cancerous tissues was significantly higher than that in the non-cancerous tissues (80.0%vs 14.1%, P < 0.05). The positivity rate of PCNA expression in the gastric mucosal cells of the MNNG group was significantly higher than that in the other four groups. The mean serum folic acid concentration of rats was significantly higher in the MNNG + folic acid group (193.70 +/- 60.73 ng/mL) than those in the control group (84.21 +/- 25.26 ng/mL) and the MNNG group (72.27 +/- 16.70 ng/mL, P < 0.05). It was shown that both low- and high-dose rofecoxib as well as folic acid interfered with the development of gastric cancer induced by MNNG in Wistar rats. CONCLUSIONS: The results indicate that rofecoxib as well as folic acid interferes with gastric carcinogenesis induced by MNNG in Wistar rats, and the suppression of gastric cell proliferation may play a crucial role in the chemoprevention of gastric cancer by rofecoxib and folic acid. The higher serum folic acid concentration of rats may play an important role in the prevention of gastric cancer.

Diet and gastric cancer: a case-control study in Shanghai urban districts.

OBJECTIVE: The incidence rates of gastric cancer in Shanghai urban districts have been markedly declining over the past three decades. From 1972 to 2001 the age-adjusted incidence rates of gastric cancer decreased from 62.0 to 32.5 per 100,000 in men and from 23.9 to 16.9 per 100,000 in women. This study aimed to investigate the relationship between environmental factors, in particular dietary factors, and the development of gastric cancer in those who lived in Shanghai urban districts for more than 15 years, and to explore the causes that led to the reduction of the incidence rates of gastric cancer in Shanghai. METHODS: One hundred and eighty-nine patients with gastric cancer and 567 age and sex-matched controls were surveyed with a questionnaire. SPSS software package was used to perform the univariate and multivariate unconditional logistic regression analysis modeling. RESULTS: Vitamin supplements, use of home refrigerators, high consumption of fresh fruits and vegetables, bean and dairy products, and good meal habits were protective factors against gastric cancer. However, family history of cancer, chronic gastric diseases, increased intake of salted, pickled, fried and smoked foods, poor meal habits, smoking and alcohol drinking were risk factors for gastric cancer. CONCLUSIONS: The reduction of the incidence of gastric cancer in Shanghai urban district in the past three decades is closely related to environmental factors, in particular dietary factors and wide use of home refrigerators.