Osamu Hachiya

Inhibition by Bacterial Lipopolysaccharide of Spontaneous and TNF-α-Induced Human Neutrophil Apoptosis In Vitro

In the previous paper (Takeda et al, Int. Immunol., 5, 691‐694, 1993), we demonstrated that tumor necrosis factor‐α (TNF‐α) promptly accelerates apoptosis of human neutrophils in vitro. In order to determine the role of neutrophil apoptosis in defending against bacterial infection, we studied the effect of bacterial lipopolysaccharide (LPS) on this process. LPS inhibited spontaneous and TNF‐α‐induced human neutrophil apoptosis in vitro, as determined by 1) light and electron microscopy, 2) flow cytometry, and 3) agarose gel electrophoresis of DNA. Low concentrations of cycloheximide, a protein synthesis inhibitor, which alone did not affect neutrophil apoptosis, were able to reduce spontaneous apoptosis inhibition by LPS, suggesting the involvement of newly synthesized protein in this phenomenon.

Intrahepatic micrometastases around liver metastases from gastric cancer

BACKGROUND/PURPOSE We aimed to clarify the association between the presence of micrometastases around liver metastases from gastric cancer and the results of hepatic resection. In addition, we investigated the influence of E-cadherin and matrix metalloproteinase (MMP)-7 expression on the development of micrometastases. METHODS Micrometastases around liver metastases were examined microscopically in 31 metastatic liver tumor specimens resected from 17 patients who had undergone hepatic resection for liver metastases from gastric cancer. E-cadherin and MMP-7 expression in the primary gastric tumor, the liver metastases, and the micrometastases were examined immunohistochemically. RESULTS Hepatic micrometastases were present in around 48% of the liver metastases, accounting for 59% of the patients. The tumor recurrence rate in the remnant liver after hepatic resection was significantly higher, and survival significantly poorer, in patients with such micrometastases than in those without. Micrometastases tended to appear around the liver metastases that had reduced E-cadherin expression. Most of the micrometastases in the lymph ducts and sinusoids showed reduced E-cadherin expression. MMP-7 expression was not correlated with the presence of micrometastases. CONCLUSIONS About half of the hepatic metastases from gastric cancer had seeded off micrometastases, and the presence of these micrometastases was associated with a poorer result of hepatic resection. Reduced E-cadherin expression in metastatic liver tumors may be associated with the development of micrometastases.

Hyperbaric Oxygen Therapy for Pancreatic and Gastrointestinal Disease

We report the results of hyperbaric oxygen therapy (HBO) for pancreatic and gastrointestinal disease. Thirty-nine patients received 100% oxygen at 2 atmospheres absolute pressure for 60 min. Results: In all four patients with liver abscess, feverishness subsided within 2.7 days after the start of HBO. All of three patients with infection after hepatic resection were relieved of systemic inflammatory response system (SIRS) and showed reduced CRP levels after HBO. In all of seven patients with acute appendicitis, pyrexia was relieved at 1.8 days after HBO introduction, and further surgery was not necessary. Among five patients with colorectal disease, HBO was effective in four, but ineffective in one. Five of six cases of infection after pancreatic resection were cured immediately after HBO. There were no complications such as middle ear inflammation, oxygen intoxication or pneumothorax. Conclusions: HBO is sometimes effective for treatment of refractory gastro enteric infections, especially those for which drainage is difficult. Pyrexia improved within 2.3 days after the start of HBO in most cases. If infection is refractory to standard antibiotics or drainage, HBO should be considered as an additional treatment. Since HBO is safe and generally cost-effective, it should be considered as an adjunct therapy for all gastro enteric infections.