Brief Reports Open Access
Copyright ©The Author(s) 2000. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 15, 2000; 6(5): 754-758
Published online Oct 15, 2000. doi: 10.3748/wjg.v6.i5.754
Gene expression profiles in gastric mucosa of sleep deprivation rats
Xi Zhong Shen, Department of Gastroenterology, Zhongshan Hospital, Shanghai Medical University, 136 Yixueyuan Road, Shanghai, China
Jenny F.L. Chow, Marcel W.L. Koo, Chi-Hin Cho, Department of Pharmacology, Faculty of Medicine, University of Hong Kong, 5 Sassoon Road, Pokfulam, Hong Kong, China
Xi Zhong Shen, graduated from Shanghai Second Medical University as a Ph.D. in 1995, associate professor of gastroenterology, major in digestive diseases, having 20 papers published.
Author contributions: All authors contributed equally to the work.
Supported by the CRCG grant from the University of Hong Kong.
Correspondence to: Dr. Marcel W.L. Koo, Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, 5 Sassoon Road, Hong Kong, China. wlkoo@hkusua.hku.hk
Telephone: 00852-8199256 Fax: 00852-28170859
Received: May 12, 2000
Revised: June 10, 2000
Accepted: June 23, 2000
Published online: October 15, 2000

Abstract
Key Words: gene expression, mucosa, gastric, stress ulcer, GI tract, sleep deprivation, cDNA, ethanol



INTRODUCTION

Stress has been shown to induce gastric mucosal lesions and lower the effectiveness of the mucosa as a barrier[1-6]. In rats, gastric ulcers can be produced by cold-restraint stress[7-9] and it is frequently employed as a model for the study of the mechanisms of stress on ulcer formation. Cold-restraint stress however is not normally encountered in human subjects while sleep deprivation is a common experience among city dwellers, night shift workers and medical professionals. It imposes stress on the body, and produces a variety of health problems[10-14]. Sleep deprivation may affect the epithelium linings of the gastrointestinal tract, because stress been demonstrated to produce gastric mucosal lesions in rats[15,16]. Although various factors has been proposed to account for this process, the precise mechanism of how sleep deprivation to affect the gastric mucosa barrier, especially at the molecular level, still remains unclear. In this project we observed the effect of sleep deprivation on the defensive factors of gastric mucosa, and used cDNA expression arrays to identify genes expressed abnormally in gastric mucosa of sleep deprivation rats.

MATERIALS AND METHODS
Rats and reagents

Male Sprague Dawley rats weighing 180 g-200 g were used in the experiments. They were housed in a temperature (22 °C + 1 °C) and humidity (65%-70%) controlled room with a day night cycle of 12 h. The rats were given standard laboratory diet (Ralston Purina Co. Chicago, IL) and tap water ad libitum. Rats were starved for 24 h and water withdrawn 1 h prior to any oral or intragastric administration of agents in order to obtain an uniform distribution of those agents onto the gastric mucosa. All chemicals used in this study were purchased from Sigma Chemical Co. (St. Louis, USA) unless specified otherwise. The present study has been examined and approved by the Committee on the Use of Live Rats for Teaching and Research of the University of Hong Kong.

Sleep disturbance

Rats for sleep disruption were placed inside a computerized rotating drum while the control animals were left undisturbed in a stationary drum. The drum was rotated 180o in 30 s at 5 min intervals and was programmed to switch off for 1 h every day at 1:00 p.m. to allow for an hour of undisturbed sleep. Sleep disturbance was continued for 1 wk before the animals were killed and the organ weight was determined. Daily water and food consumption as well as the body weight was recorded throughout the whole experimental period.

Ethanol-induced gastric mucosal damage

Rats were starved for 24 h before 1mL of 500 mL/L ethanol was administered orally to induce acute gastric mucosal damage[17]. Rats were killed 2 h later by a sharp blow on the heads followed by cervical dislocation. The stomach was removed and opened along the greater curvature. The gastric lesion area (mm2) was traced onto a glass plate and subsequently measured on a graph paper with 1 mm2 divisions. The total lesion lengths divided by the number of rats in each group was expressed as the mean ulcer index[18].

Cold-restraint-induced gastric mucosal damage

Rats were put inside the close-fitting tubular wire-mesh cages and restrained inside a cold room for 2h. At the end of the experimental period they were killed and stomachs prepared for ulcer measurement as described previously[18].

Collection of gastric mucosa

Rats were killed by ether anesthesia followed by cutting off the abdominal aortic artery. The stomachs were removed rapidly, opened along the greater curvature, and rinsed with cooled normal saline thoroughly. A longitudinal section of gastric tissue was taken from the anterior part of the stomach and then fixed in 100 mL/L buffered formalin for 24 h. It was cut into sections of 5 μm and then used in histological examination. Gastric mucosa was taken from the remaining part of the stomach by scraping with a glass slide on a glass dish on ice. They were wrapped by a piece of aluminum foil, immediately froze in liquid nitrogen and stored at -70 °C until assayed.

cDNA expression arrays[19-24]

Total RNA for cDNA expression arrays was isolated from the gastric mucosa of rat s by using the AtlasTM Pure Total RNA Isolation Kit (CLONTECH Laboratories, Inc. CA. Cat.#: K1038-1). cDNA was synthesized and radioactive labeled using 5 μg total RNA from sleep deprivation rat and normal control rat according to standardized protocols (CLONTECH Laboratories, Inc. CA. PT3140-1). AtlasTM cDNA Expression Arrays (CLONTECH Laboratories, Inc. CA.) was used for differential expression screening. Each Atlas Array includes 588 of cDNA spotted in duplicate on a positively charged nylon membrane. Plasmid and bacter-iophage DNAs are included as negative controls to confirm hybridization specificity, along with several house keeping cDNA as positive controls for normalizing mRNA abundance. After a high-stringency wash, the membranes were exposed to X-ray film (Kodak BioMax MS film Cat.# 1188077) at -70 °C with an intensifying screen for 3 d. The gene expression pattern of 588 genes in gastric mucosa of normal and sleep deprivation rats was analyzed and compared on a computerized densitometer. Signals that genes were absent or present on one of the two membranes were identifiedvisually.

Statistics

The data were statistically analyzed with the unpaired two-tailed Student’s t test.

RESULTS
Effect of sleep deprivation on body weight

Sleep disturbed rats had the same water and food consumption when compared with the control however there was a slower increase in the percentage (%) of body weight among the sleep disturbed animals (Table 1). The decrease in % body weight gain was observed as early as 2 d after sleep disturbance, and after that they gain in weight; although slower; but in a parallel fashion to that of the control (Table 1, all values at P < 0.05). Sleep disturbance ind uced a significant increase in adrenal weight (240 μg/g ± 8 μg/g body weight) when compared with the control (215 μg/g ± 6 μg/g body weight). There was no difference in weights for the thymus and spleen between the two groups.

Table 1 Effect of sleep disturbance on the percentage gain in body weight.
GroupsPercentage gain in body weight
Day 1Day 2Day 3Day 4Day 5Day 6Day 7
Control7.2 ± 2.614.4 ± 2.218.3 ± 2.423.9 ± 2.228.5 ± 3.133.1 ± 3.637.7 ± 3.2
Sleep disturbed4.8 ± 2.57.7 ± 2.3a10.5 ± 2.3a16.2 ± 2.5a19.9 ± 2.4a24.6 ± 2.7a27.2 ± 3.1a
Effect of sleep deprivation on cold-restraint stress induced gastric ulceration

After rats were restrained in 4 °C for 2 h, the ulcer index in gastric mucosa of sleep deprivation rats (41.7 mm2± 8.3 mm2) was significantly higher (P < 0.01) then it in control rats (Figure 1). The results indicated that the sleep disturbance aggravated cold-restraint stress induced gastric ulceration.

Figure 1
Figure 1 Effect of sleep disturbance on cold-restraint stress induced (4 °C for 2 h) gastric ulceration in rats. Values are means ± SEM of 12 rats in each group; bP < 0.01, vs control group.
Effect of sleep deprivation on ethanol induced gastric ulceration

After the 500 mL/L ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 mm2± 4.2 mm2) was significantly lower (P < 0.01) thenthe corresponding control (53.7 mm2± 8.13 mm2), as shown in Figure 2.

Figure 2
Figure 2 Effect of sleep deprivation on ethanol in duced (500 mL/L ethanol 1 mL p. o. for 2 h) gastric ulceration in rats. Error bars represent SEM, n = 10 for each group. bP < 0.01, vs control group.
cDNA expression array

Figure 3 shows the result obtained by hybridizing two cDNA array membranes with radioactive-labeled cDNA from gastric mucosa of control normal rat and from gastric mucosa of 7 d sleep deprivation rat. More than 10 differentially expressed genes were found in total 588 genes, most of them were digestive enzyme related genes, one of the overexpression gene in the gastric mucosa of sleep deprivation rat was identical to that of inducible heat shock protein 70.

Figure 3
Figure 3 cDNA array: Differential gene expression in gastric mucosa of normal control rat (A) and sleep deprivation rat (B). Sleep deprivation may decrease the following genes expression (Arrow 1-6) 1: bile-salt-stimulated lipase; 2: pancreatic lipase related protein 2 precursor; 3: triacylglycerol lipase precursor; 4: elastase 2 precursor; 5: trypsinogen II; 6: chymotrypsinogen B precursor, and increase the following genes expression (Arrow a-c) a: low-density lipoprotein receptor precursor; b: glucose transporter type 1; c: transferrin receptor protein. The dot for over expressed inducible heat shock protein 70 gene is circled.
DISCUSSION

In this experiment a rotating drum was used to produce sleep disturbance in rats and it was found to be an effective model for stress induction. Sleep disturbed rats had a smaller percentage gain in body weight and this was observed 2 d after sleep disturbance. This suppressive effect was not intensified after d2 and the sleep deprived rats gained in weight in a fashion paralleled to that of the controls. The statistical differences between all values of percent age gain in body weight were maintained at P < 0.05 level (Table 1). The slowing of weight gain was not due to a reduction in food intake as there was no difference in food and water consumption between the two groups. This may be the result of an increase in catabolic process that was generally observed in sleep deprived animals[25-27].

It has been found that sleep disturbance aggravated cold-restraint stress induced gastric ulceration (Figure 1). The aggravation may be the result of lowered effectiveness of the mucosal barrier. Cold-restraint stress has been shown to produce blood stagnation in the gastric mucosa[25], and sleep disturbance imposed psychological stress on the rats as was demonstrated by an increase in the adrenal weight. The increase in adrenal weight could be due to the activation of the hypothalamus-pituitary- adrenal axis producing an overstimulation on the adrenal glands[28-31]. All these factors may lead to the decrease in basal gastric mucosal blood flow and affect the defensive function of gastric mucosa. Results of this experiment indicated that the sleep deprivation did not aggravate the 500 mL/L ethanol induced gastric ulceration as expected, on the contrary, it did show some protective effect for ethanol challenge.

The human genome project’s large-scale sequencing efforts have generated partial sequence data for thousands of genes. Although many of these genes have been assigned to functional classes, the roles they play in various biological processes have yet to be elucidated. An important step toward understanding these roles is defining gene expression profiles, i.e. comparing patterns of expression in different tissues and developmental stages, in normal and disease states, or in distinct in vitro cell conditions. This can be accomplished using RT-PCR, RNase protection assays, Northern blot analysis, in situ hybridization, immunohisto-chemistry or Western blotting[32-44], but these methods focus on only a few genes at a time. A more promising approach for analyzing multiple genes simultaneously is the hybridization of entire cDNA population to nucleic acid arrays. This technology has a wide range of application, including investigating normal biological and disease processes, profiling differential gene expression, and discovering potential therapeutic and diagnostic drug targets[19-24]. In this experiment, for further investigation the reason why sleep deprivation protect gastric mucosa from ethanol insult, cDNA arrays were used to search for genes that were differentially expressed in gastric mucosa of sleep deprivation rats compared to gastric mucosa of control rats. More than 10 differentially expressed genes were found in total 588 genes (Figure 3), most of these were digestive enzyme related genes, one of the overexpression gene was inducible heat shock protein 70 gene. A variety of chemicals, viruses, and noxious stimuli such as trauma, hypoxia, or ischemia trigger the heat shock response and the subsequent synthesis of heat shock proteins[45-47]. Substantial evidence showed that heat shock is capable of protecting cells, tissues, organs, and animals from a subsequent, normally lethal heating, as well as from other types of noxious condition[48]. The protective effect of heat shock is likely mediated by overexpressed heat shock protein 70, because there is a lag between heat shock and the development of protection correlated with the production of heat shock protein 70, and protection is affected when heat shock protein 70 production is inhibited by treatment with inhibitors[49-51]. The overexpression of heat shock protein 70 was reported to protect guine a pig gastric mucosal cells from ethanol damage[52]. In conclusion, sleep disturbance imposed psychological stress on the rats as was demonstrated by decreasing body weight gain and increasing in the adrenal weight. Defensive function of the gastric mucosa was weakened by sleep deprivation thus predisposing it to ulcer formation induced by cold-restraint stress. On other hand, sleep deprivation decreased ethanol induced mucosa damage. This protective effect may be mediated by over expression of inducible heat shock protein 70 in gastric mucosa. Our experiment also showed that the cDNA arrays are the powerful approach to rapidly identify the gene expression profiles.

ACKNOWLEDGEMENTS

The authors wish to thank Mr. Leung Hon Cheung for his technical assistance in constructing the rotating drum. This work was supported by the CRCG grant from the University of Hong Kong.

Footnotes

Edited by You DY Proofread by Ma JY

References
1.  Coskun T, Yeğen BC, Alican I, Peker O, Kurtel H. Cold restraint stress-induced gastric mucosal dysfunction. Role of nitric oxide. Dig Dis Sci. 1996;41:956-963.  [PubMed]  [DOI]  [Cited in This Article: ]
2.  Ren J, Gao J, Ojeas H, Lightfoot SA, Kida M, Brewer K, Harty RF. Involvement of capsaicin-sensitive sensory neurons in stress-induced gastroduodenal mucosal injury in rats. Dig Dis Sci. 2000;45:830-836.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 13]  [Cited by in F6Publishing: 14]  [Article Influence: 0.6]  [Reference Citation Analysis (0)]
3.  Ren JY, Ojeas H, Lightfoot SA, Harty RF. Effects of capsaicin on stress-induced duodenal injury. World J Gastroentero. 1998;4:53.  [PubMed]  [DOI]  [Cited in This Article: ]
4.  Liu GS, Huang YX, Li SW, Pan BR, Wang X, Sun DY, Wang QL. Experimental study on mechanism and protection of stress ulcer produced by explosive noise. World J Gastroenterol. 1998;4:519-523.  [PubMed]  [DOI]  [Cited in This Article: ]
5.  Zhu SL, Xu GS, Wang ZJ, Chen QZ, Jiao J. Effects of electro-acupuncture on 5-HT,NOS and gastric mucosa in stress rats. China Natl J New Gastroenterol. 1997;3:179.  [PubMed]  [DOI]  [Cited in This Article: ]
6.  Zhu SL, Xu GS, Chen QZ, Wang ZJ, Jiao J. The effects of electroneedling at point Zusanli on stress gastric ulcer: The changes of nitric oxide and catecholamine in rats. China Natl J New Gastroenterol. 1996;2:203-205.  [PubMed]  [DOI]  [Cited in This Article: ]
7.  Cho CH, Koo MW, Garg GP, Ogle CW. Stress-induced gastric ulceration: its aetiology and clinical implications. Scand J Gastroenterol. 1992;27:257-262.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 36]  [Cited by in F6Publishing: 38]  [Article Influence: 1.2]  [Reference Citation Analysis (0)]
8.  Popović M, Popović N, Bokonjić D, Dobrić S. Cold restraint-induced gastric lesions in individual- and group-stressed rats. Int J Neurosci. 1997;91:1-10.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 10]  [Cited by in F6Publishing: 11]  [Article Influence: 0.4]  [Reference Citation Analysis (0)]
9.  Erin N, Okar I, Oktay S, Ercan F, Arbak S, Yeğen BC. Cold-restraint- and TRH-induced ulcer models demonstrate different biochemical and morphological manifestations in gastric and hepatic tissues in rats. Role of calcitonin. Dig Dis Sci. 1996;41:55-64.  [PubMed]  [DOI]  [Cited in This Article: ]
10.  Naitoh P, Kelly TL, Englund C. Health effects of sleep deprivation. Occup Med. 1990;5:209-237.  [PubMed]  [DOI]  [Cited in This Article: ]
11.  Jones C, Griffiths RD, Humphris G. Disturbed memory and amnesia related to intensive care. Memory. 2000;8:79-94.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 137]  [Cited by in F6Publishing: 145]  [Article Influence: 6.0]  [Reference Citation Analysis (0)]
12.  Goldberg R, Shah SJ, Halstead J, McNamara RM. Sleep problems in emergency department patients with injuries. Acad Emerg Med. 1999;6:1134-1140.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 3]  [Cited by in F6Publishing: 4]  [Article Influence: 0.2]  [Reference Citation Analysis (0)]
13.  Wyatt JP, Weber JE, Chudnofsky C. The work of the American emergency physician. J Accid Emerg Med. 1998;15:170-174.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 9]  [Cited by in F6Publishing: 10]  [Article Influence: 0.4]  [Reference Citation Analysis (0)]
14.  Armstrong KL, O'Donnell H, McCallum R, Dadds M. Childhood sleep problems: association with prenatal factors and maternal distress/depression. J Paediatr Child Health. 1998;34:263-266.  [PubMed]  [DOI]  [Cited in This Article: ]
15.  Harada N, Okajima K, Murakami K, Isobe H, Liu W. Gastric prostacyclin (PGI-2) prevents stress induced gastric mucosal in-jury in rats primarily by inhibiting leukocyte activation. Prostag-landins Other Lipid Mediat. 1999;57:291-303.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 20]  [Cited by in F6Publishing: 23]  [Article Influence: 0.9]  [Reference Citation Analysis (0)]
16.  Bentivoglio M, Grassi-Zucconi G. The pioneering experimental studies on sleep deprivation. Sleep. 1997;20:570-576.  [PubMed]  [DOI]  [Cited in This Article: ]
17.  Xu CD, Gan RB, Chen SN, Jiang SH, Xu JY. Protection of gastric mucosa from ethanol induced injury by recombinant epidermal growth factor in rats. World J Gastroenterol. 1998;4:437-438.  [PubMed]  [DOI]  [Cited in This Article: ]
18.  Cho CH, Ogle CW, Wong SH, Koo MW. Effects of zinc sulphate on ethanol- and indomethacin-induced ulceration and changes in prostaglandin E2 and histamine levels in the rat gastric glandular mucosa. Digestion. 1985;32:288-295.  [PubMed]  [DOI]  [Cited in This Article: ]
19.  Wellmann A, Thieblemont C, Pittaluga S, Sakai A, Jaffe ES, Siebert P, Raffeld M. Detection of differentially expressed genes in lymphomas using cDNA arrays: identification of clusterin as a new diagnostic marker for anaplastic large-cell lymphomas. Blood. 2000;96:398-404.  [PubMed]  [DOI]  [Cited in This Article: ]
20.  Kelly DL, Rizzino A. DNA microarray analyses of genes regulated during the differentiation of embryonic stem cells. Mol Reprod Dev. 2000;56:113-123.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in F6Publishing: 1]  [Reference Citation Analysis (0)]
21.  Eckmann L, Smith JR, Housley MP, Dwinell MB, Kagnoff MF. Analysis by high density cDNA arrays of altered gene expression in human intestinal epithelial cells in response to infection with the invasive enteric bacteria Salmonella. J Biol Chem. 2000;275:14084-14094.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 144]  [Cited by in F6Publishing: 152]  [Article Influence: 6.3]  [Reference Citation Analysis (0)]
22.  Kannan K, Amariglio N, Rechavi G, Givol D. Profile of gene expression regulated by induced p53: connection to the TGF-beta family. FEBS Lett. 2000;470:77-82.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 77]  [Cited by in F6Publishing: 81]  [Article Influence: 3.4]  [Reference Citation Analysis (0)]
23.  McCaffrey TA, Fu C, Du B, Eksinar S, Kent KC, Bush H, Kreiger K, Rosengart T, Cybulsky MI, Silverman ES. High-level expression of Egr-1 and Egr-1-inducible genes in mouse and human atherosclerosis. J Clin Invest. 2000;105:653-662.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 232]  [Cited by in F6Publishing: 237]  [Article Influence: 9.9]  [Reference Citation Analysis (0)]
24.  Wang L, Lu W, Chen YG, Zhou XM, Gu JR. Comparison of gene expression between normal colon mucosa and colon carcinoma by means of messenger RNA differential display. World J Gastroenterol. 1999;5:533-534.  [PubMed]  [DOI]  [Cited in This Article: ]
25.  Bergmann BM, Rechtschaffen A, Gilliland MA, Quintans J. Effect of extended sleep deprivation on tumor growth in rats. Am J Physiol. 1996;271:R1460-R1464.  [PubMed]  [DOI]  [Cited in This Article: ]
26.  Bergmann BM, Gilliland MA, Balzano S, Refetoff S, Rechtschaffen A. Sleep deprivation in the rat: XIX. Effects of thyroxine administration. Sleep. 1995;18:317-324.  [PubMed]  [DOI]  [Cited in This Article: ]
27.  Spiegel K, Leproult R, Van Cauter E. Impact of sleep debt on metabolic and endocrine function. Lancet. 1999;354:1435-1439.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2405]  [Cited by in F6Publishing: 2201]  [Article Influence: 88.0]  [Reference Citation Analysis (0)]
28.  Vgontzas AN, Mastorakos G, Bixler EO, Kales A, Gold PW, Chrousos GP. Sleep deprivation effects on the activity of the hypothalamic pituitary adrenal and growth axes: potential clinical implications. Clin Endocrinol (Oxf). 1999;51:205-215.  [PubMed]  [DOI]  [Cited in This Article: ]
29.  Suchecki D, Lobo LL, Hipolide DC, Tufik S. Increased ACTH and corticos terone secretion induced by different methods of paradoxical sleep deprivation. J Sleep Res. 1998;7:276-281.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 125]  [Cited by in F6Publishing: 135]  [Article Influence: 5.2]  [Reference Citation Analysis (0)]
30.  Kuhs H, Farber D, Tolle R. Serum prolactin, growth hormone, total corticoids, thyroid hormones and thyrotropine during serial therapeutic sleep deprivation. Biol Psychiatry. 1996;39:857-864.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 15]  [Cited by in F6Publishing: 18]  [Article Influence: 0.6]  [Reference Citation Analysis (0)]
31.  Kresyun VI. The features of the influence of psychotropic agents on the structural-functional state of the adrenals of intact and stressed animals. Neurosci Behav Physiol. 1993;23:357-360.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in F6Publishing: 1]  [Reference Citation Analysis (0)]
32.  Lin GY, Chen ZL, Lu CM, Li Y, Ping XJ, Huang R. Immunohistochemical study on p53, H rasp21, c-erbB-2 protein and PCNA expression in HCC tissues o f Han and minority ethnic patients. World J Gastroentero. 2000;6:234-238.  [PubMed]  [DOI]  [Cited in This Article: ]
33.  Wu HG, Zhou LB, Pan YY, Huang C, Chen HP, Shi Z, Hua XG. Study of the mechanisms of acupuncture and moxibustion treatment for ulcerative colitis rats in view of the gene expression of cytokines. World J Gastroentero. 1999;5:51 5-517.  [PubMed]  [DOI]  [Cited in This Article: ]
34.  Luo YQ, Wu MC, Cong WM. Gene expression of hepatocyte growth factor and its receptor in HCCand nontumorous liver tissues. World J Gastroentero. 1999;5:119-121.  [PubMed]  [DOI]  [Cited in This Article: ]
35.  Zhang JX, Shen SR, Zhang XH, Chen X. Expression of Cx genes in liver and stomach of different embryonic stages. World J Gastroentero. 1999;5:47-49.  [PubMed]  [DOI]  [Cited in This Article: ]
36.  Yang JM, Wang RQ, Bu BG, Zhou ZC, Fang DC, Luo YH. Effect of hepatitis C virus infection on expression of several cancer associated gene products in hepatocellular carcinoma. World J Gastroentero. 1999;5:25-27.  [PubMed]  [DOI]  [Cited in This Article: ]
37.  Qian QJ, Xue HB, Qu ZQ, Fang SG, Cao HF, Wu MC. In situ detection of tumor infiltrating lymphocytes expressing perforin and fas ligand genes in human HCC. World J Gastroentero. 1999;5:12-14.  [PubMed]  [DOI]  [Cited in This Article: ]
38.  Xiao CZ, Dai YM, Yu HY, Wang JJ, Ni CR. Relationship between expression of CD44v6 and nm23 H1 and tumor invasion and metastasis in hepatocellular car cinoma. World J Gastroentero. 1998;4:412-414.  [PubMed]  [DOI]  [Cited in This Article: ]
39.  Wang XW, Xu B. Expression of alpha fetoprotein messenger RNA in BEL-7404 human hepatoma cells and effect of L-4 oxalysine on the expression. World J Gastroentero. 1998;4:294-297.  [PubMed]  [DOI]  [Cited in This Article: ]
40.  Sun JJ, Zhou XD, Zhou G, Liu YK. Expression of intercellular adhesive molecule 1 in liver cancer tissues andliver cancer metastasis. World J Gastroentero. 1998;4:202-205.  [PubMed]  [DOI]  [Cited in This Article: ]
41.  Zhang QX, Dou YL, Shi XY, Ding Y. Expression of somatostatin mRNA in various differentiated types of gastric carcinoma. World J Gastroentero. 1998;4:48-51.  [PubMed]  [DOI]  [Cited in This Article: ]
42.  Tao HQ, Lin YZ, Wang RN. Significance of vascular endothelial growth factor messenger RNA expression in gastric cancer. World J Gastroenterol. 1998;4:10-13.  [PubMed]  [DOI]  [Cited in This Article: ]
43.  Yang DH, Xiu C, Yang B, Gu JR, Qian LF, Qu SM. Expression of insulin like growth factor II and its receptor in liver cells of chronic liver diseases. China Natl J New Gastroenterol. 1997;3:117-118.  [PubMed]  [DOI]  [Cited in This Article: ]
44.  Ke CS, Li DF, Wang W, Wang YM. Study on clinical pathology and immunoh istochemistry of chronic erosive gastritis. China Natl J New Gastroenterol. 1997;3:113.  [PubMed]  [DOI]  [Cited in This Article: ]
45.  Stojadinovic A, Kiang J, Smallridge R, Galloway R, Shea-Donohue T. Induction of heat-shock protein 72 protects against ischemia/reperfusion in rat small intestine. Gastroenterology. 1995;109:505-515.  [PubMed]  [DOI]  [Cited in This Article: ]
46.  Marber MS, Mestril R, Chi SH, Sayen MR, Yellon DM, Dillmann WH. Overexpression of the rat inducible 70-kD heat stress protein in a transgenic mouse increases the resistance of the heart to ischemic injury. J Clin Invest. 1995;95:1446-1456.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 632]  [Cited by in F6Publishing: 659]  [Article Influence: 22.7]  [Reference Citation Analysis (0)]
47.  Maroni P, Bendinelli P, Zuccorononno C, Schiaffonati L, Piccoletti R. Cellular signalling after in vivo heat shock in the liver. Cell Biol Int. 2000;24:145-152.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 18]  [Cited by in F6Publishing: 19]  [Article Influence: 0.8]  [Reference Citation Analysis (0)]
48.  Kiang JG, Tsokos GC. Heat shock protein 70 kDa: molecular biology, biochemistry, and physiology. Pharmacol Ther. 1998;80:183-201.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 829]  [Cited by in F6Publishing: 780]  [Article Influence: 30.0]  [Reference Citation Analysis (0)]
49.  Burkart V, Liu H, Bellmann K, Wissing D, Jäättela M, Cavallo MG, Pozzilli P, Briviba K, Kolb H. Natural resistance of human beta cells toward nitric oxide is mediated by heat shock protein 70. J Biol Chem. 2000;275:19521-19528.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 61]  [Cited by in F6Publishing: 67]  [Article Influence: 2.8]  [Reference Citation Analysis (0)]
50.  Rokutan K. Role of heat shock proteins in gastric mucosal protection. J Gastroenterol Hepatol. 2000;15 Suppl:D12-D19.  [PubMed]  [DOI]  [Cited in This Article: ]
51.  Kiang JG, Ding XZ, McClain DE. Thermotolerance attenuates heatinduced increases in [Ca2 ]i and HSP-72 synthesis but not heat induced intracellular acidification in human A 431 cells. J Investig Med. 1996;44:53-63.  [PubMed]  [DOI]  [Cited in This Article: ]
52.  Nakamura K, Rokutan K, Marui N, Aoike A, Kawai K. Induction of heat shock proteins and their implication in protection against ethanol-induced damage in cultured guinea pig gastric mucosal cells. Gastroenterology. 1991;101:161-166.  [PubMed]  [DOI]  [Cited in This Article: ]