Co-localization of TFF2 with gland mucous cell mucin in gastric mucous cells and in extracellular mucous gel adherent to normal and damaged gastric mucosa

Trefoil factor 2 (TFF2) is mucin associated peptide that has a mucosal barrier function in addition to participating in repair and healing. We examined the localization of TFF2 and gastric mucins in gastric mucous cells, the surface mucous gel layer (SMGL) adherent to normal gastric mucosa, and in the mucoid cap covering gastric erosions. Carnoy's solution, or formalin/picric acid-fixed paraffin embedded materials from resected stomachs and formalin-fixed paraffin embedded gastric biopsy materials were used. Sections were immunostained for the TFF2 and histochemically stained for gastric mucins. In addition, thick sectioned gastric mucosa fixed in Carnoy's solution were stained with FITC-labeled GSA-II lectin specific for gland mucous cell mucin and examined for three-dimensional images of the SMGL using a confocal laser scanning microscope. The TFF2 and gland mucous cell mucin were found intermixed together in the gastric gland mucous cells, in the SMGL in laminated layers, and in the mucoid cap. A laminated arrangement of continuous sheets of gland mucous cell mucin in the SMGL was demonstrated in the three-dimensional images. Co-localization of the TFF2 with gland mucous cell mucin suggests a physical interaction between the TFF2 and gland mucous cell mucin. The TFF2 trapped in the adherent mucins may be responsible for mucosal defense, healing, and repair.

Roles of virD4 and cagG genes in the cag pathogenicity island of Helicobacter pylori using a Mongolian gerbil model

BACKGROUND AND AIMS

The roles of the virD4 and the cagG genes in the cag pathogenicity island of Helicobacter pylori for gastroduodenal pathogenesis are unclear and their roles in vivo have not been examined.

METHODS

Seven week old male Mongolian gerbils were inoculated with the wild type H pylori TN2GF4, its isogenic virD4, or cagG mutants. Animals were sacrificed at 4, 12, and 24 weeks after inoculation. Gastric inflammation and H pylori density were evaluated by histology, inflammatory response (as measured by interleukin (IL)-1beta mRNA levels), proliferative activity (as assessed by 5'-bromo-2'deoxyuridine labelling indices), and host systemic reaction (as measured by anti-H pylori IgG antibody).

RESULTS

Degree of gastric inflammation, proliferative activity, and mucosal IL-1beta mRNA levels remained low throughout the first 12 weeks in gerbils infected with the virD4 mutants. Degree of gastric inflammation and proliferative activity increased at 24 weeks with the virD4 mutants reaching levels comparative with those seen at four weeks with the wild-type strains. Mucosal IL-1beta mRNA levels were also increased at 24 weeks with the virD4 mutants and levels at 24 weeks were similar between the wild-type and virD4 mutants. In contrast, gerbils infected with the cagG mutants had reduced ability to colonise gerbils, and no or little gastric inflammation or proliferative activity was observed.

CONCLUSIONS

Loss of the virD4 gene temporally retarded but did not abrogate gastric inflammation. Loss of the cagG gene abolished gastric inflammation partially via reduced ability to colonise gerbils. Unknown factors related to the type IV secretion system other than CagA may influence gastric inflammation.

Gene therapy for colorectal cancer

Colorectal cancer is an important public health problem worldwide. Gene therapy has therapeutic potential for patients with advanced or recurrent colorectal cancer, incurable by conventional treatments. To date, many strategies of gene therapy have been explored, including mutant gene correction, prodrug activation, immune stimulation and genetically-modified oncolytic viruses. Although the preclinical results of gene therapy for colorectal cancer have shown promise, gene therapy is still at an early stage of clinical development and has not yet shown a significant therapeutic benefit for patients. The main obstacles for introduction of gene therapy to patients are poor targeting selectivity of the vectors and inefficient gene transfer. As the science supporting tumour-selective vectors evolves, gene therapy may expand rapidly in the clinical practice of colorectal cancer treatment.

Duodenogastric reflux and Helicobacter pylori infection synergistically increase gastric mucosal cell proliferative activity in Mongolian gerbils

BACKGROUND

Helicobacter pylori and duodenogastric reflux (DGR) are both recognized as aetiological factors in chronic gastritis and gastric carcinogenesis. In this study, a Mongolian gerbil (MG) model was used to investigate the histopathological changes in the gastric mucosa resulting from DGR and/or H. pylori infection.

METHODS

One-hundred-and-eleven 7-week-old, specific-pathogen-free, male MGs were divided into four groups: normal controls, gerbils with surgically induced DGR, and H. pylori-infected gerbils with and without DGR. Gerbils were killed 4, 12 and 26 weeks after DGR surgery, their stomachs removed and sections prepared. Sections were fixed immediately in 20% phosphate-buffered formalin and subjected to haematoxylin and eosin staining, Alcian blue at pH 2.5/periodic acid-Schiff staining, and immunostaining for smooth muscle cells, H. pylori and 5'-bromo-2'-deoxyuridine (BrdU).

RESULTS

The gastric mucosa of H. pylori-infected gerbils showed chronic active gastritis irrespective of DGR throughout the experimental period. The gastric mucosa of H. pylori-infected gerbils with DGR demonstrated higher BrdU labelling than in the other groups.

CONCLUSIONS

In MGs, DGR and H. pylori infection synergistically increased gastric mucosal cell proliferative activity. DGR and H. pylori infection may be involved synergistically in gastric carcinogenesis by increasing cell proliferative activity.

Paradoxical role of Helicobacter pylori infection: protective effect against ethanol-induced gastric mucosal injury in Mongolian gerbils

We investigated the effect of ethanol (a representative necrotizing agent) on gastritis induced by Helicobacter pylori infection in Mongolian gerbils. Seventy-eight gerbils were used. Four and 12 weeks after H. pylori inoculation, 30% ethanol was administered into the stomach. The stomachs were removed after 30 min, the intramucosal prostaglandin (PG) E2 concentration was measured, and histopathology was recorded. H. pylori infection caused chronic active gastritis, gastric erosion, hypersecretion of mucin from gland mucus cells, and a rise in the activity of intramucosal PGE2. After ethanol administration, gastric erosion was significantly less in animals infected with H. pylori than in uninfected animals. In conclusion, in the early stage of H. pylori infection, accentuation of intramucosal PGE2 and hypersecretion of mucin from gland mucus cells have a protective effect against gastric mucosal injury induced by necrotizing agents.

Role of N-methyl-N-nitrosourea in the induction of intestinal metaplasia and gastric adenocarcinoma in Mongolian gerbils infected with Helicobacter pylori

BACKGROUND

Progression from intestinal metaplasia to neoplasia has not been demonstrated experimentally. The hypothesis that gastric adenocarcinoma arises from intestinal metaplasia was tested in a Mongolian gerbil model of Helicobacter pylori (H. pylori) infection.

METHODS

One hundred and fourteen specific pathogen-free gerbils were divided in five groups. A and D: infected with H. pylori and administered the carcinogen N-methyl-N-nitrosourea (MNU); C and E: received MNU; B: H. pylori, but no MNU. Animals were killed at 41 weeks, stomachs were mapped, and the relationship between metaplasia and cancer was assessed.

RESULTS

Intestinal metaplasia occurred more frequently in the H. pylori-infected, MNU-treated gerbils than in those receiving H. pylori inoculation only (P < 0.01). Carcinomas arose only in H. pylori-infected animals receiving MNU (8 well differentiated, 2 poorly differentiated, and 10 signet ring). Intestinal metaplasia occurred more frequently in association with intestinal-type carcinoma.

CONCLUSIONS

Intestinal metaplasia and adenocarcinoma arise in stomachs subjected to the same injuries (in this study, H. pylori and MNU). Only two intestinal-type carcinomas were contiguous to intestinal metaplasia; all other tumors developed most commonly at non-metaplastic sites. This suggests that in this animal model H. pylori and MNU induce several phenotypes of gastric cancer, but intestinal metaplasia may be a direct precursor only in a subset of the intestinal-type tumors.

Timing of N-methyl-N-nitrosourea administration affects gastric carcinogenesis in Mongolian gerbils infected with Helicobacter pylori

In Mongolian gerbils, the gastric mucosa shows dramatic changes after Helicobacter pylori inoculation. The influence of the timing of N-methyl-N-nitrosourea (MNU) administration after H. pylori inoculation on gastric carcinogenesis was investigated. Ninety-two gerbils were divided into four groups. One group was given MNU at 24 weeks, and another at 1 week, after H. pylori inoculation. The other groups received only MNU. Stomachs were excised for histological examination 20 weeks after completing the MNU treatment. Carcinomas arose only in animals given MNU 1 week after H. pylori inoculation. In the relationship between H. pylori and gastric carcinogenesis, H. pylori is a promoter rather than an initiator, and other environmental factors (the timing of MNU administration) play important roles.

Retroperitoneal malignant fibrous histiocytoma surgically removed six times using a harmonic scalpel

This paper describes a patient with retroperitoneal malignant fibrous histiocytoma who underwent surgical removal of the tumor 6 times. It is difficult to remove locally recurrent retroperitoneal malignant fibrous histiocytoma many times by repeat surgery, since the tumor tends to adhere tightly to the surrounding scar tissue. In the 5th and 6th operations we conducted on the patient, a harmonic scalpel was useful for separating the tumor from the scar tissue at the previous surgical site.

Revascularization using the short gastric vessels of the gastric tube after subtotal esophagectomy for intrathoracic esophageal carcinoma

BACKGROUND

Maintaining sufficient blood flow to the substitutive organ after esophagectomy is essential to decrease the risk of anastomotic leakage.

STUDY DESIGN

Forty-one patients underwent subtotal esophagectomy for intrathoracic esophageal carcinoma and reconstruction using the gastric tube. Additional vascular anastomosis between the short gastric vessels and the vessels in the neck was performed in 15 patients. Tissue blood flow was measured by laser Doppler flowmetry before and after vascular anastomosis. The incidence of anastomotic leakage in the revascularization group was compared with that in the remaining 26 patients.

RESULTS

Venous anastomosis was performed in 14 patients and arterial anastomosis in 9. There was a significant increase in tissue blood flow after venous anastomosis alone (mean percent increase: 36%; p < 0.01), and after arterial and venous anastomoses (mean percent increase: 108%; p < 0.01). No anastomotic leakage was observed in the revascularization group; six patients (23.1%) in the control group had leakage (p < 0.05). Patients in the revascularization group started taking a meal 10.0 +/- 0.4 days postoperatively, compared with 15.1 +/- 1.8 days in the control group (p < 0.05).

CONCLUSIONS

Additional vascular anastomosis in esophageal reconstruction after subtotal esophagectomy achieved good results. This procedure can reduce the risk of anastomotic leakage and may be useful for esophageal reconstruction.

Additional microvascular anastomosis in reconstruction after total esophagectomy for cervical esophageal carcinoma

BACKGROUND

Maintaining sufficient blood flow to the substitute organ after total esophagectomy is essential for decreasing the risk of anastomotic leakage. Additional venous, or arterial and venous, anastomoses between the vessels of the gastric tube and the vessels in the neck after total esophagectomy are described for 11 patients with cervical esophageal carcinoma.

METHODS

The tissue blood flow was measured by laser Doppler flowmetry before and after anastomosis. Venous anastomosis was performed for all 11 patients, and arterial anastomosis was added for 7 patients.

RESULTS

A significant increase in tissue blood flow was observed after venous anastomosis alone (mean, 19%; P < 0.05) and after arterial and venous anastomoses (mean 43%; P < 0.01). There was no anastomotic leakage or hospital death.

CONCLUSIONS

This procedure may reduce the risk of anastomotic leakage especially in the case of pharyngogastrostomy following total esophagectomy.

Use of the Harmonic Scalpel in open abdominoperineal surgery for rectal carcinoma

We describe a technique of open abdominoperineal resection with the use of the Harmonic Scalpel in seven patients. Using this instrument we dissected all pelvic vessels, including the middle hemorrhoidal artery, with no subsequent bleeding. In addition, we divided the levator ani muscles completely in the abdominal procedure alone.

Distinction of the shape of Helicobacter pylori using stereo pairs constructed from digitized light microscopic images

This study was performed to distinguish between the coccoid form or spiral forms of Helicobacter pylori (Hp) and to elucidate the pathologic significance of these shapes of Hp. Specimens obtained from human or Mongolian gerbil stomachs were fixed in Carnoy's solution and embedded in paraffin. Sections 3 or 10 microm thick were stained with polyclonal anti-Hp antibody by the immunoperoxidase method. Stereo pairs were prepared from these thick sections by computer-assisted reconstruction. The two shapes of Hp were easily distinguishable by this method. In the human stomach, the proportions of Hp in the surface mucous gel layer (SMGL) and the gastric pits were 31.5% and 68.5%, and the percentage of the spiral form varied from 31.9% to 66.3%. In Mongolian gerbils, a higher proportion of Hp colonized the SMGL, and the spiral form existed more frequently both in the SMGL and on the surfaces of the surface mucous cells.

Helicobacter pylori infection enhances N-methyl-N-nitrosourea-induced stomach carcinogenesis in the Mongolian gerbil

No previous report has demonstrated the relationship between Helicobacter pylori (HP) infection and gastric carcinogenesis in an experimental animal model. A total of 170 male Mongolian gerbils (MGs) were divided into nine groups (18 < or = n < or = 20 for each group). MGs of four groups were inoculated with HP before or after continuous N-methyl-N-nitrosourea (MNU) administration via the drinking water. Both intestinal-type and diffuse-type adenocarcinomas, including signet ring-cell carcinomas, were found at 40 weeks after the study commenced, but only in the HP inoculation groups with MNU exposure and not in the MNU alone or HP inoculation alone control groups. The present findings demonstrate that HP infection increases the incidence of MNU-induced adenocarcinoma of the glandular stomach in MGs.

A modified stapling technique for esophagojejunostomy after total or proximal gastrectomy

BACKGROUND

Stapling devices reduce the leakage rate of digestive tract anastomoses, but they increase the risk of strictures. We investigated a newly modified technique of end-to-end anastomosis stapling in esophagojejunostomy after total or proximal gastrectomy.

STUDY DESIGN

A modified stapling technique (using a stapled anastomosis between esophageal mucosal and intact jejunal layers, with hand-sewn seromuscular sutures between the esophagus and jejunum) was used in 21 patients (modified group), while a conventionally stapled anastomosis was performed in 17 patients (conventional group). The incidence and severity of dysphagia and the size of the anastomosis as determined from x ray films were compared in the two groups.

RESULTS

The modified technique provided significantly better results for dysphagia severity than the conventional method (p = 0.0025). Most of the patients in the modified group had mild dysphagia, and most patients in the conventional group complained of moderate or severe dysphagia. In the modified group, the inner diameter of the anastomosis was 12.1 +/- 2.5 mm, significantly larger than that in the conventional group (10.0 +/- 1.8 mm; p = 0.009).

CONCLUSIONS

The use of our modified stapling technique can minimize the risk of anastomotic stricture and the feeling of dysphagia after esophagojejunostomy.

Intraportal US with 20-MHz and 30-MHz scanning catheters. Work in progress

Intraportal ultrasonography (US) with scanning catheters was attempted in nine patients with various biliary tract diseases, to evaluate the portal venous system for tumor invasion. Intraportal US was performed successfully in seven patients. Intraportal US scans were compared with images obtained with arterial portography, direct portography, and intraoperative US. Intraportal and intraoperative US revealed cancer invasion into the wall of the portal venous trunk in two patients. Negative findings for cancer invasion with intraportal US were verified with intraoperative US and laparoscopic examination in five cases. Arterial portography was unable to delineate the fine portal venous wall configuration in six of the seven patients, and direct portographic images were not fully diagnostic of tumor invasion in three cases. The improved detection of tumor invasion to the portal venous system with intraportal US was helpful in determining the appropriate treatment for biliary tract disease in these patients.

[Alpha-recoiling behaviour of 222Rn on 226Ra-sources]

By using electroplated 226Ra-sources, the ejection and injection behaviour of alpha-recoil atoms, 222Rn, which generates on the source surface during alpha-decay process of its parent 226Ra, has been basically investigated. The thinly and uniformly distributed 226Ra-sources were prepared with high deposition yield by the molecular plating technique, in which radium was deposited on a stainless-steel cathode from an isopropanol media by adopting a rotating platinum anode, applied potential of 900 V, and deposition time of 40 min. The ejection efficiency of 222Rn was determined by using the relationship between the 226Ra strength on source and the 222Rn-one transferred on a stainless steel collector in vacuum. It was found that the ejection (or injection) efficiency was greatly influenced on the source preparation methods. The highest ejection efficiency (up to 30%) could be obtained from the electroplated source, whereas the same source could be resulted in the significant decrease of this value (till 2%) after simple ignition treatment. The retention efficiency of 222Rn injected on some collector materials was evaluated to be more than 70% over the tested collectors. From these results, it was concluded that the recoil effects should be most important to interpret the emanation phenomena even in nature.