Jun Matsuzawa

p16INK4 is inactivated by extensive CpG methylation in human hepatocellular carcinoma

Abstract Background & Aims: The molecular status of the p16 INK4 tumor-suppressor gene has not been fully elucidated in hepatocellular carcinoma. The aim of this study was to clarify the mechanism that gives rise to inactivation of p16 INK4 in hepatocellular carcinoma. Methods: The status of p16 INK4 was evaluated in 60 hepatocellular carcinomas by immunohistochemical staining, differential polymerase chain reaction, single-strand conformational polymorphism, methylation-specific polymerase chain reaction, and methylation-sensitive single nucleotide primer extension. Results: Immunohistochemical staining showed that 29 of the 60 tumors exhibited complete loss of p16 INK4 expression. High levels of DNA methylation were detected in 24 of 29 cases of hepatocellular carcinoma with negative p16 INK4 expression, with methylation of 60%–85% of the CpG islands. In contrast, the level of methylation was p16 INK4 staining, and no methylation was detected in tumors with positive immunostaining. Intragenic alteration of p16 INK4 was detected in 4 cases. Conclusions: A strong correlation was found between the extent of methylation and the degree of expression of p16 INK4 in tumor tissues, indicating that epigenetic change due to extensive CpG methylation is the main cause of inactivation of p16 INK4 in hepatocellular carcinoma. GASTROENTEROLOGY 1999;116:394-400

Influence of Interleukin-10 on the Interleukin-1 Receptor Antagonist/Interleukin-1β Ratio in the Colonic Mucosa of Ulcerative Colitis

A decrease in the ratio of IL-1ra/IL-1β produced regionally by the colonic mucosa of patients with ulcerative colitis (UC) is believed to play a role in the pathogenesis of UC. To investigate factors influencing intramucosal IL-1ra/IL-1β ratios, we evaluated polymorphism of the IL-1ra gene and the production of mucosal cytokines in Japanese patients with UC. Colonic biopsy specimens of mucosal tissue were placed in organ cultures for 24 h. Then, the supernatant concentrations of IL-1β, IL-1ra, IL-8, IL-4, IL-10, and TGF-β were assayed by ELISA. Genomic DNA was extracted from patient peripheral blood samples, then IL-1ra gene polymorphism was determined using PCR amplification. The mucosa from patients with active stage UC showed a tendency toward a decreased IL-1ra/IL-1β ratio. In the resolving stage, IL-1ra/IL-1β ratios increased with increasing IL-10 and TGF-β concentrations. The addition of human recombinant IL-10 to the culture supernatants produced concentration-dependent inhibition of IL-1β. In Japanese patients with UC, the IL-1ra allele gene 2 phenotype had no effect on the IL-1ra/IL-1β ratio. Our findings suggest that a relative deficiency of IL-10 in patients with UC may contribute to persistent inflammatory changes.

Leukocytapheresis is effective in inducing but not in maintaining remission in ulcerative colitis.

Goals and Background: Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by dense infiltration of lymphocytes, plasma cells, neutrophils, and monocyte-macrophages into the colonic mucosa. Leukocytapheresis is a procedure for selectively removing white blood cells from withdrawn blood. It is used for the treatment of several autoimmune diseases. This study was performed to evaluate the effectiveness of leukocytapheresis for inducing and maintaining remission in corticosteroid-resistant UC, as compared with corticosteroid-responsive UC. Study: Forty-five patients with active UC who were treated with a dose of 1 mg/kg per day or more of prednisolone given systemically for at least 2 weeks were evaluated. Twenty patients (6 males, 14 females) in whom improvement was induced only by high doses of prednisolone were allocated as the corticosteroid-responsive group. The other 25 patients (11 males, 14 females) who did not respond to the above-mentioned dose of prednisolone therapy were allocated as the corticosteroid-resistant group and received leukocytapheresis therapy once a week for 5 weeks. Of patients who had a remission, the corticosteroid-responsive group continued to have the conventional therapy and the corticosteroid-resistant group were given leukocytapheresis once every 4 weeks for at least 2 years as maintenance therapy. Results: Remission was induced by 5 weeks of leukocytapheresis in 23 of the 25 (92%) patients with corticosteroid-resistant active UC. The number of days required to achieve remission of UC was fewer in patients who received leukocytapheresis than in those who did not. Follow-up study of the patients who had remission showed similar relapse rates at 2 years in the patients who received leukocytapheresis and those given high doses of prednisolone alone. Conclusions: Leukocytapheresis is an effective treatment of acute corticosteroid-resistant UC but does not prevent the recurrence of UC.

The striking effect of hyperbaric oxygenation therapy in the management of chronic idiopathic intestinal pseudo-obstruction

Chronic idiopathic intestinal pseudo-obstruction is one of the disorders that is most refractory to medical and surgical treatment. Even when patients are given nutritional support, including total parenteral nutrition, obstructive symptoms seldom disappear. We report a case of chronic idiopathic intestinal pseudo-obstruction, due to myopathy, in which hyperbaric oxygenation therapy was strikingly effective. The presence of myopathy was histologically confirmed on the surgically resected jejunal specimen. Hyperbaric oxygenation resulted not only in relief of the patients obstructive symptoms but also in a rapid decrease of abnormally accumulated intestinal gas. At last, he could resume oral intake without any critical adverse effects. These observations strongly suggest that hyperbaric oxygenation can be an effective therapy in the management of chronic idiopathic intestinal pseudo-obstruction.