AgNOR and rasp21 expression in gastric mucosal lesions caused by Helicobacter pylori infection

AIM: To investigate AgNOR and rasp21 expression levels in gastric mucosal lesions caused by Helicobacter pylori (Hp) infection in order to gain insight into the related biological processes (i.e. tumor-like behavior) and possible underlying mechanism supporting Hp pathogenesis.

METHODS: Hp infection was diagnosed in using the standard Campylobacter-like organism test along with Wathin-Starry staining. The expression of AgNOR was detected by the silver colloid staining technique. The expression of rasp21 was detected by monoclonal antibody and immunohistochemical staining using the ABC method. The study included a total of 278 patients with endoscopically- and pathologically-confirmed gastric mucosal lesions, representing chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), intestinal metaplasia, dysplasia, and gastric cancer. Among these, 146 of the patients were Hp-positive and 132 were Hp-negative.

RESULTS: The Hp-positive group of patients showed significantly greater AgNOR in the gastric mucosal lesions than the Hp-negative group, with the exception of the CSG sub-group (P < 0.05 or P < 0.01). The positive rate of rasp21 expression in gastric mucosal lesions in the Hp-positive group was also significantly higher than that in the Hp-negative group, with the exception of the CSG and CAG sub-groups (P < 0.05).

CONCLUSION: Hp-positive gastric mucosal lesions show biological behaviour of tumors. Hp may act as a promoter to activate the ras gene and to stimulate cell over-proliferation.

Clinical and experimental studies on stomach carcinoma treated with Yangwei Kangliu granules

AIM

To study the anti-cancer mechanism of Yangwei Kangliu (YWKL) granules from the view point of red blood cell (RBC) immunity and to investigate the relationship between RBC immunity and T lymphocyte immunity.

METHODS

Fifty patients with advanced gastric carcinoma were treated with a combination of YWKL granules and chemotherapy. Venous blood samples were obtained before treatment and after one course of treatment. The rosette rate of c-3b-receptor (RBC-C-3bRR), tumor and red cell (RRTR) and RBC immune complex (RBC-ICR) were measured under microscopy by counting the rosettes formed by sensitized or unsensitized yeast adherence. The T lymphocyte subset was observed by the method of APAAP. Control patients were treated with chemotherapy alone (n = 20). In addition, mouse tumor studies were performed to investigate the dynamic changes of RBC-C-3bRR, RRTR and RBC-ICR in response to treatment with YWKL granules (n = 30). Mice treated with chemotherapy alone (n = 30) or water alone (n = 30) were used as controls.

RESULTS

The clinical therapeutic effect of combination treatment with YWKL granules and chemotherapy (i.e. the treatment group) was markedly superior to that of chemotherapy alone (i.e. the control group) (P < 0.01). In the treatment group, the rosette rates of RBC-C-3bRR and of RRTR were significantly increased (P < 0.01) after treatment, the rate of RBC-ICR was markedly decreased (P < 0.01), and the ratio of CD4 to CD8 was obviously elevated (P < 0.01). Moreover, CD8 was much lower (P < 0.01) and the ratio of CD4 to CD8 was much higher (P < 0.01) than that in the control group. The RRTR rate was positively correlated with the ratio of CD4 to CD8. In mice, on day 9 of bearing cancer, the tumor weight in the group treated with YWKL granules alone was much lower than that of the tumors in the control mice groups; in addition, the YWKL treated mice showed higher RBC immune function than the mice of the two control groups. On day 13 of bearing cancer, however, the differences in both tumor weight and RBC immune function had disappeared.

CONCLUSION

The anti-cancer mechanism of YWKL granules may involve enhancement of RBC immunity and of T lymphocyte immune function, which is supported by the finding of RBC immune function being correlated with T lymphocyte immune function.

Clinicopathogenic studies of acute diarrhea in children

AIM: To identify etiologic pathogens of acute diarrhea in children and to determine the diagnostic value of stool pH.

METHODS: From May 1988 to April 1992, 368 children with acute diarrhea were studied. Fresh stools were routinely examined, and stool pH was tested with pH paper. Samples were placed in Cary-Blair culture medium and were sent to the lab for bacterial isolation and identification. Rotavirus was identified in the supernatant by ELISA.

RESULTS: Thirty-one pathogens and 385 bacterial strains were found in the 368 samples, with a detection rate of 67.7%, including 37.8% of mixed infections. Among the bacteria families, vibrionaceae was the most common (39.7%), and among bacteria genera, aeromonas was the most common (26.8%). In bacterial diarrhea, stool pH tended to be basic, while in viral diarrhea it tended to be acidic.

CONCLUSION: There are 31 pathogens for children’s acute diarrhea in this area. It is quite difficult to make an etiologic diagnosis only by clinical signs. However, stool pH is of some value for early disease diagnosis.

Double-bullet radioimmunotargeting therapy in 31 primary liver cancer patients

AIM: To observe the effect of double bullet immunotargeting therapy with chemotherapy and internal radiotherapy on primary liver cancer.

METHODS: The polyclonal horse antibody against human AFP (anti-AFPAb) and the monoclonal murine antibody against human AFP (anti-AFPMcAb) were used as carriers, and ¹³¹I and mitomycin C (MMC) were used as warheads to form double bullet, i.e. ¹³¹I anti-AFPMcAb-MMC (double bullet 1) and ¹³¹I anti-AFPAb-MMC (double bullet 2) prepared using the modified chloramine T method. Double bullet targeting therapy was administered by intravenous drip once a month in 31 patients (treatment group) with unresectable primary liver cancer. Among them, 4, 17 and 10 patients were administered 1, 2 and 3 times, and the median radiation dose (MBq/case) was 193.5 ± 37.74; 651.9 ± 232.4, and 992.0 ± 230.5 respectively.

METHODS: Tumor shrinkage, decrease in AFP, and 1 and 2 -year survival rates were significantly higher than the control groups who received transarterial infusion (TAI) or transarterial chemoembolization (TACE) at the same time (50.0%, 15/30 vs 30.0%, 9/30, P < 0.05; 66.7%, 18/27 vs 28.0%, 7/25, P < 0.01 and 50.0%, 34.0% vs 33.0%, 3.3%, P < 0.01, respectively). Furthermore, the tumor progression rate (10%) in the treatment group was significantly lower than that of the control group (40.0%, P < 0.01).

CONCLUSION: Double bullet target therapy is more effective than traditional therapies due to the synergistic effects of the antibody, radioisotope, and anticancer agents, which together, enhance tumor killing.

Loss of heterozygosity and mRNA expression at deleted in colorectal cancer gene locus in gastric cancer

AIM: To assess the effects of the deleted in colorectal cancer (DCC) gene changes on the development and progression of gastric cancer.

METHODS: The loss of heterozygosity (LOH) and mRNA expression DCC gastric cancer using a PCR-based detection method.

RESULTS: LOH was found in 35.3% (18/51) of the specimens, and the LOH was more frequently detected in tumors from patients with stage III or IV cancer (50.5%) than those in stages I or II (14.3%) (P < 0.05). The occurrence of LOH was not found to correlate with the histological type, tumor size, invasion depth and lymph node metastasis of gastric cancer. The mRNA expression of the DCC gene was studied in 26 of the 51 cases, of which LOE was found in 30.8% (8/26). LOE was not significantly correlated to LOH or other clinicopathological parameters.

CONCLUSION: LOH and LOE of DCC gene are frequently encountered in gastric cancer, and the LOH of DCC gene is a late event associated with progression of gastric cancer.

Immunohistochemical study on endocrine-like tumor cells in colorectal carcinomas

AIM: To evaluate the clinical significance of endocrine-like tumor cells in human colorectal carcinomas.

METHODS: The immunohistochemistry method (ABC) using a rabbit polyclonal antibody against human chromogranin A (CGA) was employed to determine changes in endocrine-like tumor cells from the surgically resected colorectal carcinoma tissues of patients (35 males and 27 females, aged from 19 to 78 years, with a mean age of 50.3 years). Of the 62 specimens, 44 were from rectal carcinomas, 18 from colonic carcinomas, 14 from lymph nodes and 48 from non-involvement. Dukes classification revealed 19 of the cases were in stage A, 29 cases were in stage B and 14 cases were in stage C. All of the specimens were fixed with 10% formalin, embedded with paraffin and cut into 5 μm sections. Additionally, the correlations among CGA-positive tumor cells, as well as the clinicopathologic data, age and sex of the patients, were also investigated.

RESULTS: CGA-positive tumor cells were found in 35.5% of the patients with colorectal cancers, representing 20.0% (5 of 25) and 45.9% (17 of 37) of the aged and non-aged, respectively. These differences were significant (χ² test, P < 0.05). Nevertheless, no significant correlations were found between the CGA-positive tumor cells and the sex, Dukes stages, tumor location, degree of histological differentiation or presence of lymph node metastasis.

CONCLUSION: The low incidence of endocrine-like tumor cells found in the aged patients may be a new pathological feature for colorectal carcinomas, which could explain why the aged patients usually had a better prognosis. The exact significance of these findings requires further characterization.

Effects of electro-acupuncture on 5-HT, NOS and the gastric mucosa of stress rats

AIM: To study the effects of electro-acupuncture (EA) on 5-hydroxytryptophan (5-HT) levels, nitrous oxide (NOS) levels, nitric oxide (NO) levels, and the gastric mucosa in stress rats.

METHODS: The changes of 5-HT and NOS were measured in the gastric mucosa, and NO and 5-HT were measured in the serum by biochemical methods. The gastric mucosa was examined pathohistologically in the stress rats with gastric mucosa damage after EA. The changes before and after stress by EA were compared.

RESULTS: EA decreased the gastric mucosa damage index in the stress rats (2.71 ± 0.40 to 1.86 ± 0.69, P < 0.01). EA normalized NOS level in gastric mucosa to the control group. The changes before stress by EA was more obvious than that after stress. EA lowered the 5-HT levels in the gastric mucosa (μg/g wet weight, 6.91 ± 3.08 to 4.51 ± 1.62, P < 0.01). EA recovered the NO level in serum of the stress rats (μmol/L, 5.78 ± 1.49 to 7.91 ± 1.11, P < 0.05), and increased the levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in serum continuously.

CONCLUSION: EA stimulation normalizes the NOS and NO levels in the gastric mucosa of stress rats. EA also lowers the high 5-HT levels and induces NO release.

Survival and malignant phenotype changes of human hepatoma SMMC-7721 cell line induced by cryopreservation at -50 °C

AIM: To investigate the effect of cryopreservation at -50 °C on the human hepatoma SMMC-7721 cell line.

METHODS: With 15% DMSO as a cryoprotectant, the SMMC-7721 cells were cryopreserved at -50 °C, then thawed and recultured. The survival rate, mitotic index and LDH isoenzymes were compared between pre- and post-cryopreservation.

RESULTS: Thirteen hours after the thaw, the mitotic index of cryopreserved SMMC-7721 cells decreased by 1.09%. The mode scope of chromosome number (46-53) after cryopreservation tended to transfer to that of normal human cells, and the percentage of metaphases containing 46 chromosomes changed from 0% to 16%. LDH isoenzymes changed from H-like model (LDH3(29.3%) > LDH4 (26.8%) > LDH2 (25.3%) > LDH5 (14.9%) > LDH1 (3.6%) to M-like model (LDH4 (48.3%) > LDH5 (28.3%) > LDH3 (18.9%) > LDH2 (4.4%) > LDH1 (0%)). This suggests that the survival rate could reach over 95%.

CONCLUSION: Cryopreservation at -50 °C can be a convenient method for the cryopreservation of cell lines. However, cryopreservation at -50 °C is likely involved in the changes of the malignant phenotypes of the human hepatoma SMMC-7721 cell line, and may induce the differentiation of malignant cells.

Source of blood supply and embolization treatment in cavernous hemangioma and sclerosis of the liver

AIM: To investigate the source of the blood supply in carvenous hemangioma of liver (CHL), and provide a feasible treatment for CHL via thehepatic artery.

METHODS: (1) Portovenography, hepatic arteriography and portal vein staining were performed in 5 patients to determine the origin of the blood supply. Two casts of hepatic blood vessels from resected specimens were observed. (2) Clinical data from 75 patients (30 males, 45 females, aged 25-57 years, mean of 37.4) were obtained. Of these, 56 were of solitary type (44 on the right lobe, 12 on the left, with 4 having intraparenchyma), and 19 were of multiple type (9 on the right, 2 the left, 8 whole liver). Twenty-two patients were treated with sclerosis, 50 by embolization via hepatic artery, and 3 were excised.

RESULTS: In the 5 cases where portography was used, the contrast medium did not enter the tumor, and the tumor appeared as low density area, with the intrahepatic branches of the portal vein pushed aside. In the 5 cases with where portal vein staining was used, the normal liver parenchyma stained a deep blue; however, the tumor was not stained. The tumor area appeared as a round vacant cavity in the 2 specimen casts. For the 72 patients treated with sclerosis or embolization via hepatic artery or through interventional method, the tumors diminished by 10%-30% in diameter, and no tumors grew larger.

CONCLUSION: The blood supply of CHL originates from the hepatic artery. Tumors treated with sclerosis and embolization decreased in size or got fibrotic.

Alterations of erythrocyte ATPase activity and oxygen consumption in patients with liver-blood deficiency syndrome

AIM: To investigate the pathophysiology of erythrocyte energy metabolic changes of patients with the traditional Chinese Medicine (TCM) liver-blood deficiency syndrome (LBDS).

METHODS: Erythrocyte membrane ATPase activity and oxygen consumption rate (OCR) were determined in 66 patients with LBDS, including 35 patients with iron deficiency anemia and 31 patients with chronic aplastic anemia. Thirty healthy adults served as controls.

RESULTS: ATPase activity and OCR were decreased in patients with LBDS.

CONCLUSION: The decreased erythrocyte ATPase activity and OCR might cause the energy hypometabolism in LBDS patients.

Relation between bile acids and myocardial damage in obstructive jaundice

AIM: To investigate the morphologic changes of the myocardium and its relationship to serum bile acids in obstructive jaundice.

METHODS: Part 1: 35 rats were randomly assigned to three groups: Group I (BDL1, n = 11), the common bile duct (CBD) was ligated and severed and mice were then sacrificed after one week. Group I (BDL2, n = 11), the CBD was ligated and severed and mice were then killed after two weeks. Group I (SO, n = 13), the CBD was isolated. Hearts were collected for morphologic studies and blood was taken to determine the total serum bile acids (TAB). Part 2: 13 rats received gastric intubation of 10% 4 mL/kg sodium cholate. Their serum TBA and the heart’s morphologic changes were then examined.

RESULTS: One to two weeks after the CBD was ligated and severed, damage was evident in the mitochondria within the myocardium and the serum TBA was significantly increased. When rats were administered sodium cholate to make their peak blood concentration mimic the average blood concentration in BDL2, a similar degree of myocardial damage was observed.

CONCLUSION: An increase in endogenous bile acids is one causative factor of myocardial damage in obstructive jaundice.

Analysis of fibronectin, fibronectin receptor and interleukin-1 in patients with cirrhosis treated by the Yanggan Jieyu decoction

AIM: To investigate the effects of the Yanggan Jieyu (YGJY, nourishing the liver and alleviating mental depression) decoction on the plasma concentrations of fibronectin (FN), fibronectin receptor (FNR), tumor necrosis factor alpha (TNF-α), and the activity of interleukin-1 (IL-1) in patients with cirrhosis.

METHODS: Thirty-four cases of decompensated cirrhosis were divided into the YGJY decoction treatment group and the control group (patients received standard treatment). FN, FNR and TNF-α were measured by ELISA and expressed as mg/L (FN, FNR) and ng/L (TNF-α). IL-1 was measured by mice thymocyte proliferation using a β scintillation counter and was expressed as cpm.

RESULTS: In the YGJY decoction treatment group, FN and TNF-α levels increased significantly (P < 0.01 and P < 0.05, respectively), and FNR and IL-1 levels decreased significantly (P < 0.05 and P < 0.05, respectively). In the control group, FN, FNR, TNF-α, and IL-1 levels did not significantly change.

CONCLUSION: YGJY decoction could prevent hepatic fibrosis by adjusting the plasma levels of FN, FNR, TNF-α and IL-1, which could mediate cirrhosis formation. This data is of clinical significance.

Effects of tetrandrine on gastric mucosa and liver in portal hypertensive rats

AIM: To study the effects of tetrandrine on portal hypertensive gastric mucosal lesions.

METHODS: Portal hypertensive models were induced in Wistar rats by 60% CCl₄ 3 mL/kg body weight through subcutaneous injection, once every 4 d for 56 d. The animals were randomly divided into portal hypertension, tetrandrine and propranolol groups and subsequently, treated by normal saline, tetrandrine and propranolol respectively for 15 d. Some healthy rats were used as control group. Portal venous pressure (PVP), gastric mucosal prostaglandin E₂ (PGE₂) content, gastric mucosal blood flow (GMBF), gastric adherent mucus (GAM), ALT, ALP and serum total bilirubin (STB), were measured and liver tissues were observed histologically.

RESULTS: In tetrandrine group and propranolol group, PVP was significantly lower (1.43 ± 0.13, 1.45 ± 0.12 vs 1.89 ± 0.18 kPa; P < 0.01) and gastric mucosal PGE₂ content (138.59 ± 12.68, 129.98 ± 14.31 vs 104.65 ± 12.97 pg/mg; P < 0.01), GMBF (11.80 ± 3.47, 10.54 ± 3.63 vs 6.61 ± 2.82 mL·h·kg; P < 0.05) and GAM (3.01 ± 0.15, 2.98 ± 0.21 vs 2.24 mg ± 0.26 mg; P < 0.01) was significantly higher than that in portal hypertension control group. In tetrandrine group intrahepatic proliferative fibrous tissues were reduced and serum ALT (47.67 ± 25.90 vs 189.33 ± 41.21 King U; P < 0.01), ALP (0.22 ± 0.04 vs 0.31 ± 0.06 μmol·s^-1/L; P < 0.01) and STB (4.75 ± 0.76 vs 11.12 ± 2.93 μmol/L; P < 0.01) were lowered as compared with those in portal hypertension control group. ALT (209.34 ± 36.91 vs 189.33 ± 41.21 King U; P > 0.05) and STB (11.63 ± 3.01 vs 11.12 ± 2.93 μmol/L; P > 0.05) in propranolol group were not different from that in portal hypertension control group, but it showed more marked hepatocellular degeneration and necrosis and elevation of ALP (0.46 ± 0.05 vs 0.31 ± 0.06 μmol·s^-1/L; P < 0.01).

CONCLUSION: Tetrandrine can improve the functions of gastric mucosa and liver, and facilitate the absorption of intrahepatic proliferative fibrous tissues. Propranolol can aggravate hepatosis though it may improve portal hypertensive gastric mucosal lesions.

Difference between periportal and pericentral Kupffer cells in lipopolysaccharide uptake in rats

AIM: To reveal the difference in the ability of Kupffer cells in the periportal and pericentral regions of the liver to uptake lipopolysaccharides (LPS) injected into the portal vein.

METHODS: Male Wistar rats were divided into two groups: normal control group (n = 6) and GdCl₃-treated group (n = 8). Sixteen hours before the experiment, rats in the GdCl₃-treated group were injected with GdCl₃via the tail vein to eliminate Kupffer cell function specifically in the periportal region. LPS at a dose of 20 μg/100 g body weight was injected into rats of both groups via the portal vein. Zero, 2, 5, 10, 30, and 60 min after LPS injection, liver samples were obtained and the distribution of LPS in Kupffer cells was observed by immunofluorescence imaging of monoclonal antibody-specific LPS staining using a confocal laser scanning microscope.

RESULTS: In the normal control group, positive reactions to LPS were found in Kupffer cells in the periportal region with the peak at two minutes after LPS injection. Kupffer cells in the pericentral region showed the peak at five minutes after LPS injection, but its fluorescent intensity to LPS at the peak time in the cytoplasm was significantly lower than that of Kupffer cells in the pericentral region. In the GdCl₃-treated group, Kupffer cells in the pericentral region showed the peak at two minutes following LPS injection, and the LPS fluorescent intensity showed no significant difference from that of the normal control rats at the peak point. No significant changes of LPS fluorescent intensities were found in Kupffer cells in the periportal region at various time points following LPS injection in GdCl₃-treated rats.

CONCLUSION: Kupffer cells in the periportal and pericentral regions showed differences in LPS uptake via the portal vein.

Effects of metoclopramide on gastrointestinal myoelectric activity in rats

AIM: To investigate the effects of metoclopramide (MCP) action on myoelectric activity in the antrum and small intestine.

METHODS: Ten healthy male Wistar rats, weighing 250-350 g, were anesthetized with ketamine hydrochloride (100 mg/kg, intramuscularly). Four pairs of bipolar stainless steel electrodes 3 mm apart were implanted on the serosal surface of the antrum at one, 10 and 20 cm distal to the pylorus. Five to ten days following the operation, the gastrointestinal myoelectric activity of fasted rats after intramuscular injection of 2.5, six and 12 mg/kg MCP was recorded using a 8-channel EEG machine, and these values were quantitatively compared with the myoelectric activity after saline injection.

RESULTS: In fasted rats, 2.5 mg/kg MCP increased the amplitude of spike activity (402.0 ± 138.4 μV, vs 345 ± 163.4 μV, P < 0.05) and the percentage of the slow wave-containing spike bursts (60.4% ± 22.0% vs 47.4% ± 22.5%, P < 0.01) of small intestine (1 cm distal to the pylorus), but did not affect the myoelectric activity of the antrum. Six and 12 mg/kg MCP increased the amplitude of both the slow wave (332.8 ± 200.1 μV vs 191.2 ± 143.9 μV, P < 0.01; 330.0 ± 197.1 μV vs 191.2 ± 143.9 μV, P < 0.05) and the spike activity of the antrum (180.5 ± 69.7 μV vs 121.8 ± 63.3 μV, P < 0.05; 174.5 ± 71.7 μV vs 123.8 ± 63.3 μV, P < 0.05), while in small intestine (1 cm distal to the pylorus) only the amplitude of spike activity (407.3 ± 179.0 μV vs 345.0 ± 163.4 μV, P < 0.05; 456.0 ± 145.4 μV vs 345.0 ± 163.4 μV, P < 0.05) and the percentage of the slow wave containing spike bursts (61.7% ± 26.5% vs 47.4% ± 22.5%, P < 0.01; 59.1% ± 17.3% vs 47.4% ± 22.5%, P < 0.01) was increased and the latent period significantly prolonged (2.5 ± 0.35 min vs 0.77 ± 0.18 min, P < 0.01).

CONCLUSION: Different mechanisms may be involved in enhancing the myoelectric activity of the antrum and small intestine following MCP administration.

Clinicopathological risk factors and prognostic evaluation in hepatocellular carcinoma recurrence after surgery

AIM: To analyze the clinicopathological risk factors in hepatocellular carcinoma recurrence after surgery.

METHODS: We used significance testing (χ² and Student’s t-test) of single and multiple factors, and Wilcoxon Cox tropic examination; a retrospective clinicopathological analysis was performed on 156 cases of hepatocellular carcinoma after hepatectomy.

RESULTS: Of the 156 cases, 68.4%, 57.3%, 46.7%, 31.5%, and 28.6% had one, two, three, four, and five postoperative tumor-free years, respectively; the total recurrence rate was 53.2% (83/156). In the 83 recurrent cases, 65 were intrahepatic subclinical, with a resection rate of 78.3% (65/83). The relevant factors involved in recurrence were: male gender, tumor number and size, capsule infiltration, and portal vein involvement. These factors were an obvious influence on the prognosis of the patients with postoperative hepatocellular carcinoma (P < 0.05). In the recurrent liver carcinomas, 63.1% of tumor nodes (41/65) were at the ipsilateral segment of the primary tumor nodes.

CONCLUSION: Male gender, tumor number and size, capsule infiltration, and portal vein involvement are factors for postoperative hepatocellular carcinoma recurrence. Recurrence is mainly unicentral. The right front liver lobe is the segment with a high rate of recurrence.

P21 and CEA expression and AgNOR counts in dimethylhydrazine-induced colon carcinoma in rats

AIM: To study P21 and carcinoembryonic antigen (CEA) expression and to measure argyrophilic nucleolar organizer region (AgNOR) counts in various lesions of colonic mucosa and the mechanism of carcinogenesis.

METHODS: Thirty-eight male Wistar rats were injected with dimethylhydrazine (DMH) once a week for 25 wk. P21 and CEA expression was detected by immunohistochemical methods, and AgNOR was counted by silver staining paraffin sections from various colonic lesions.

RESULTS: The incidence of colonic carcinoma in DMH-treated rats was 71.05% (27/38), and lymph node metastasis occurred in six rats. Immunohistochemical studies showed that P21 was primarily expressed in dysplasia and carcinomas, while CEA was expressed in carcinomas and metastatic tumors. AgNOR counts were higher in dysplasia and carcinomas. There were significant differences in P21 and CEA expression between benign and malignant lesions (P < 0.05). The difference in AgNOR counts was also significant between normal and dysplastic tissues, and between dysplasia and malignant lesions (P < 0.05).

CONCLUSION: Dysplasia is a premalignant change of colonic carcinoma. The detection of P21 via immunohistochemistry and AgNOR counting may be an important clinical screening technique for colon carcinoma and premalignant lesions.

Effects of metoclopramide on gastrointestinal myoelectric activity in rats

AIM

To investigate the effects of metoclopramide (MCP) action on myoelectric activity in the antrum and small intestine.

METHODS

Ten healthy male Wistar rats, weighing 250-350 g, were anesthetized with ketamine hydrochloride (100 mg/kg, intramuscularly). Four pairs of bipolar stainless steel electrodes 3 mm apart were implanted on the serosal surface of the antrum at one, 10 and 20 cm distal to the pylorus. Five to ten days following the operation, the gastrointestinal myoelectric activity of fasted rats after intramuscular injection of 2.5, six and 12 mg/kg MCP was recorded using a 8-channel EEG machine, and these values were quantitatively compared with the myoelectric activity after saline injection.

RESULTS

In fasted rats, 2.5 mg/kg MCP increased the amplitude of spike activity (402.0 ± 138.4 μV, vs 345 ± 163.4 μV, P < 0.05) and the percentage of the slow wave-containing spike bursts (60.4% ± 22.0% vs 47.4% ± 22.5%, P < 0.01) of small intestine (1 cm distal to the pylorus), but did not affect the myoelectric activity of the antrum. Six and 12 mg/kg MCP increased the amplitude of both the slow wave (332.8 ± 200.1 μV vs 191.2 ± 143.9 μV, P < 0.01; 330.0 ± 197.1 μV vs 191.2 ± 143.9 μV, P < 0.05) and the spike activity of the antrum (180.5 ± 69.7 μV vs 121.8 ± 63.3 μV, P < 0.05; 174.5 ± 71.7 μV vs 123.8 ± 63.3 μV, P < 0.05), while in small intestine (1 cm distal to the pylorus) only the amplitude of spike activity (407.3 ± 179.0 μV vs 345.0 ± 163.4 μV, P < 0.05; 456.0 ± 145.4 μV vs 345.0 ± 163.4 μV, P < 0.05) and the percentage of the slow wave containing spike bursts (61.7% ± 26.5% vs 47.4% ± 22.5%, P < 0.01; 59.1% ± 17.3% vs 47.4% ± 22.5%, P < 0.01) was increased and the latent period significantly prolonged (2.5 ± 0.35 min vs 0.77 ± 0.18 min, P < 0.01).

CONCLUSION

Different mechanisms may be involved in enhancing the myoelectric activity of the antrum and small intestine following MCP administration.

Survival and malignant phenotype changes of human hepatoma SMMC-7721 cell line induced by cryopreservation at -50 °C

AIM: To investigate the effect of cryopreservation at -50 °C on the human hepatoma SMMC-7721 cell line.

METHODS: With 15% DMSO as a cryoprotectant, the SMMC-7721 cells were cryopreserved at -50 °C, then thawed and recultured. The survival rate, mitotic index and LDH isoenzymes were compared between pre- and post-cryopreservation.

RESULTS: Thirteen hours after the thaw, the mitotic index of cryopreserved SMMC-7721 cells decreased by 1.09%. The mode scope of chromosome number (46-53) after cryopreservation tended to transfer to that of normal human cells, and the percentage of metaphases containing 46 chromosomes changed from 0% to 16%. LDH isoenzymes changed from H-like model (LDH3(29.3%) > LDH4 (26.8%) > LDH2 (25.3%) > LDH5 (14.9%) > LDH1 (3.6%) to M-like model (LDH4 (48.3%) > LDH5 (28.3%) > LDH3 (18.9%) > LDH2 (4.4%) > LDH1 (0%)). This suggests that the survival rate could reach over 95%.

CONCLUSION: Cryopreservation at -50 °C can be a convenient method for the cryopreservation of cell lines. However, cryopreservation at -50 °C is likely involved in the changes of the malignant phenotypes of the human hepatoma SMMC-7721 cell line, and may induce the differentiation of malignant cells.

Changes in mucosal permeability to lipopolysaccharide in the colon of chronic alcoholic rats

AIM: To evaluate the effects of chronic alcohol abuse on mucosal permeability to lipopolysaccharide (LPS) in the colon of rats.

METHODS: Escherichia coli LPS (20 mg/L) was injected into the colon of chronic alcoholic rats (n = 10) that had been supplied with Lieber diet every other day for six weeks. Before and 5, 10, 20, and 30 min after LPS injection, portal vein blood samples were obtained and the LPS levels in the blood were measured. The distribution of LPS in the colon tissues was observed with confocal laser scanning microscopy by immunofluorescence technique using a monoclonal antibody specific to the lipid A region of LPS. Normal rats were used as the controls (n = 6).

RESULTS: Before LPS injection, LPS levels in the portal vein blood of chronic alcoholic rats were significantly higher than that of the normal controls (3.56 ± 0.67 ng/L vs 2.45 ± 0.15 ng/L, P < 0.01). At 5, 10, 20, and 30 min after LPS injection, LPS levels were significantly higher than that before LPS injection (173.56 ± 3.45 ng/L, 154.78 ± 0.57 ng/L, 43.89 ± 0.67 ng/L, 45.38 ± 0.89 ng/L vs 3.56 ± 0.67 ng/L, respectively, P < 0.01). Most mucosal cells in the chronic alcoholic rats showed strong positive reactions to LPS, but in the normal rats, there were no significant changes in portal vein blood LPS levels and in the fluorescence reactions to LPS in the mucosal cells after LPS injection.

CONCLUSION: Chronic alcohol abuse results in a significant increase in LPS permeability in the colon mucosa cells of rats.

Endoscopic monitoring in small bowel transplantation

AIM: To investigate the role of endoscopic monitoring in small bowel transplantation.

METHODS: This study was conducted in two parts—an initial experimental study followed by a clinical study. In the experimental study, segmental small bowel allotransplantation was performed on white outbred pigs. Stomas were created for exteriorization of the proximal and distal ends of the intestines (Thiry-Vella loop). The grafts were monitored by endoscopy via stomas, with or without immunosuppressive therapy. For the clinical study, the whole small-bowel allograft of a woman with short bowel syndrome was endoscopically monitored via distal stoma.

RESULTS: The most common endoscopic findings of graft rejection following small bowel allotransplantation were mucosal erythema, erosion, and ulceration. Diffuse ulceration with bleeding occurred in the late phase of rejection.

CONCLUSION: Endoscopic monitoring is essential to small bowel transplantation.

Characteristics of upper digestive tract diseases in Bohai Bay fishermen

AIM: To study the characteristics of upper digestive tract diseases (UDTDs) in fishermen who live in Bohai Bay.

METHODS: An investigation was carried out in 1488 fishermen with symptoms of UDTDs (aside from liver, biliary and pancreatic diseases) during the time period between December 1991 and February 1995. This investigation included medical history evaluations, physical, gastroscopic and pathological examinations, tests for Helicobacter pylori (H. pylori) infection, and analysis of the nitrate content in their drinking water.

RESULTS: Among the 1488 subjects investigated, 1467 suffered from one or more of the 14 UDTD diseases, most of which were chronic atrophic gastritis (CAG, 1103 cases), peptic ulcers (268 cases), and cancer of the upper digestive tract (25 cases).

CONCLUSION: The incidence rate of UDTDs tends to be high among fishermen due to their particular living habits, the high nitrate content of their drinking water, etc. In addition, the clinical manifestations of UDTDs in fishermen are significantly different from those of the inland residents.