Ammonia inhibits proliferation and cell cycle progression at S-phase in human gastric cells.

Helicobacter pylori (Hp) has strong urease activity and produces a large amount of ammonia in the stomach. In animal studies, ammonia was shown to accelerate cell kinetics of gastric mucosa, and long-term exposure of the stomach to ammonia leads to mucosal atrophy. To understand this process, we examined the effects of ammonia on the growth and cell cycle progression of human gastric cancer cell lines (HGC-27, MKN1, MKN45) using flow-cytometric analysis.

[A cross-sectional study of factors associated with production of Japanese cedar pollen specific IgE antibody and total IgE antibody, and symptoms of Japanese cedar pollinosis in primary school children].

Frequency of and factors associated with sensitization by Japanese cedar pollen (JCP) and Japanese cedar pollinosis (JCPS) were analyzed by a cross-sectional method. Four hundred and five primary school children in a rural town were examined by a questionnaire filled out by their parents and a serum test in May, 1994. Children with positive JCP specific IgE antibody (CAP-RAST score > = 1) comprised 39%, and those with a score of 2 or more, 35%.

Age-related enhancement of tumor necrosis factor (TNF) production in mice.

We investigated age-related changes in the production of TNF at the cellular level using immunocompetent peritoneal and spleen cells from C3H/He mice of various ages. The density of cultured peritoneal macrophages and spleen cells required for TNF production was at least 5 x 10(5) cells/dish. The optimal concentration of OK-432 for 24-h culture of peritoneal macrophages (1 x 10(6) cells) and spleen cells (1 x 10(7) cells) was 0.

Effect of ammonia on cell-cycle progression of human gastric cancer cells.

Aim: Ammonia is a cytotoxic factor of Helicobacter pylori that is involved in gastric mucosal injury. This study was designed to show whether ammonia has an effect on the cell-cycle progression in human gastric cells in vitro.

Materials And Methods: We studied the effects of ammonia and ammonium chloride on cell growth and cell-cycle progression of the human gastric cancer cell line HGC-27.

[A case control study of risk factors for Japanese cedar pollinosis].

Risk factors for Japanese cedar pollinosis including past or family history of allergic diseases, smoking and passive smoking, dwelling conditions, and life events were analyzed by a case control method. Patients with Japanese cedar pollinosis (22 males and 67 females) were matched with a corresponding number of patients without potential symptoms of pollinosis according to sex and age (+/- 5 years). The mean age was 39 years in both groups.