Tetsuro Yamane

Inhibitory Effect of (—)‐Epigallocatechin Gallate on Carcinogenesis with N‐Ethyl‐N′‐nitro‐N‐nitrosoguanidine in Mouse Duodenum

(—)‐Epigallocatechin gallate (EGCG) is the main polyphenolic constituent of green tea infusion and inhibits tumor promotion by teleocidin in two‐stage carcinogenesis on mouse skin. In this work, EGCG was found to inhibit tumor promotion in the gastrointestinal tract in a model system of mouse duodenal carcinogenesis with N‐ethyl‐N′‐nitro‐N‐nitrosoguanidine. The duodenal tumors that developed were studied stereomicroscopically and histologically.

Inhibitory effects and toxicity of green tea polyphenols for gastrointestinal carcinogenesis.

Recently, an epidemiologic study showed a lower risk of gastrointestinal carcinogenesis in green tea drinkers. An experiment on two‐stage skin carcinogenesis in mice showed that (−)‐epigallocatechin gallate (EGCG), one of the main constituents of green tea, inhibited tumor formation.

Inhibitory effects of fucoxanthin, a natural carotenoid, on N-myc expression and cell cycle progression in human malignant tumor cells

Fucoxanthin, a natural carotenoid prepared from brown algae, inhibited the growth of GOTO cells, a human neuroblastoma cell line. Fucoxanthin at 10 micrograms/ml reduced the growth rate of GOTO cells to 38% of the control at day 3 after drug treatment. Flowcytometric analysis revealed that fucoxanthin caused the arrest in the G0-G1 phase of cell cycle. Expression of N-myc gene was proved to be decreased by fucoxanthin as early as 4 h after treatment at 10 micrograms/ml and that may be important for the mechanism of anti-proliferative action of the carotenoid.

Clinicopathological characteristics of gastric cancer in the elderly.

The clinicopathological features of 380 elderly patients 70 years of age or older with gastric cancer were reviewed retrospectively from hospital records between 1969 and 1993. They were then compared with 1134 middle-aged patients between 40 and 69 years. The elderly constituted 18.4% of all gastric cancer patients 20 years ago but now comprise 24.4% of all patients in the most recent decade, despite the overall decrease in the rate of gastric cancer. The distinguishing histological features of gastric cancer in the elderly were an intestinal type of cancer, expansive tumour growth and synchronous multiplicity of the lesions. Elderly patients had a similar rate of tumour extension but had poorer survival as compared with the middle-aged patients. Post-operative death within 30 days after surgery was also higher in the elderly than in the middle-aged patients.

Inhibition of 1,2-dimethylhydrazine-induced oxidative DNA damage by green tea extract in rat.

Following subcutaneous injection of 1,2‐dimethylhydrazine (DMH), which is carcinogenic to rat colon and liver, to Sprague‐Dawley rats, a significant increase of 8‐hydroxydeoxyguanosine (8‐OHdG) was observed in the DNA of colonic mucosa and liver. The 8‐OHdG formation reached the maximal level at about 24 h after the DMH injection. On the other hand, no increase of 8‐OHdG was observed in the DNA of the kidney. Drinking green tea extract (GTE) for ten days prior to the DMH injection significantly inhibited the formation of 8‐OHdG in the colon. These findings demonstrate that DMH causes oxidative damage to the DNA of its target organ, and that GTE protects colonic mucosa from this oxidative damage.

Physiologic status of the anorectum following sphincter-saving resection for carcinoma of the rectum

The physiologic status of the anorectum after low anterior resections or pull-through operations of the rectum was evaluated clinically and by manometric studies. It was demonstrated that the presence of a normal anal resting pressure and an anorectal reflex were important to achieve postoperative continence after sphincter-saving operations. In patients with anastomotic leaks and poor function, a marked high-pressure zone in the anal canal and an anorectal reflex were not found, but as local inflammation resulting from the anastomotic leak disappeared, these parameters returned to normal. A normal anorectal reflex was found in one of three patients after Bacon-type pull-through operations, but the remaining two showed an increase of anal canal pressure during colonic distention. These results indicate that an elevation of anal-canal pressure in response to colonic distention plays a significant role in fecal continence at the time of “a sense of urgency” if internal sphincter function is impaired.

How safe are the xenogeneic hemostats?--Report of a case of severe systemic allergic reaction.

We report herein the unusual case of a 55-year-old woman who developed a severe systemic allergy to Avitene (microfibrillar collagen hydrochloride), a xenogeneic agent sometimes used for topical hemostasis in laparoscopic cholecystectomy. The patient developed fever, general fatigue, mild liver dysfuction, and prominent eosinophilia postoperatively. A skin allergy test confirmed that these abnormal findings were attributable to an allergic reaction to Avitene.

Inhibition of mucosal lipid hyperoxidation by green tea extract in 1,2-dimethylhydrazine-induced rat colonic carcinogenesis

Phosphatidylcholine hydroperoxide (PCOOH) measured using a chemiluminescence detector to examine colonic mucosal lipid hyperoxidation increased after injection of 1,2-dimethylhydrazine and green tea extract (GTE), which we previously showed inhibited carcinogenesis and oxidative DNA damage in the gastrointestinal tract. Therefore, the hyperoxidation of membrane phospholipids reflected well the degree of DNA damage and carcinogenic alteration, and may be a useful intermediate biomarker for initiation of carcinogenesis.

Conservative surgery for regional lymphadenectomy in the treatment of early gastric carcinoma

The relationship between lymph node metastases and postoperative prognosis in 209 patients with early gastric cancer was studied. As to the postoperative prognosis in relation to the extent of lymph nodes dissection, no significant difference was observed among the age-corrected 5-year survival rates following three surgical procedures in patients with early gastric cancer. Age-corrected 5-year survival rates were 0.92±0.44 R1-resection, 0.95±0.44 in R2-resection, and 1.00±0.06 in R3-resection, respectively. In addition, in 71 patients including 33 with early gastric cancer and 38 patients with advanced but relative early gastric carcinoma, the relationship between the immunostatus and postoperative prognosis was investigated. Postoperative age-corrected 5-year survival rate (0.904±1.153) of the optimal responders with good immunostatus was significantly higher than that (0.582±1.153) of the suboptimal responders with impaired immunostatus (P<0.01). Thus, conservative surgery for regional lymphadenectomy may be an effective procedure for cure of early gastric carcinoma, particularly in cases of a carcinoma limited to the mucosal area of the stomach.

Alteration of adenosine deaminase levels in peripheral blood lymphocytes of patients with gastric cancer

The present study was undertaken to determine the adenosine deaminase (ADA) activity of peripheral lymphocytes in patients with gastric cancer, with respect to the cancer progression, the effect of surgery and/or immunotherapy. The gastric cancer patients showed lower lymphocyte ADA activity than did the normal control. The lymphocyte ADA activity did not decrease with the cancer progression. There was a significant correlation between lymphocyte ADA activity and blastogenesis of lymphocyte by phytohemaglutinin or concanavalin A. Six months following gastrectomy, the lymphocyte ADA activity was increased, as compared with the preoperative value. The ADA activity of patients on post-operative OK-432 showed a greater increase, as compared to that of patients not given this treatment. In conclusion, decreased lymphocyte ADA activity in gastric cancer patients might be due to either the cancer bearing status or to the immunological suppression.