[Influence of surface finishing and polymerization method on the fatigue strength of the dental plastic materials].
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Acrylic Resins↗
Biomedical subjects
N Saitoh
Publications and source records attributed to N Saitoh.
Relative risks of death due to liver disease among Japanese male adults having various statuses for hepatitis B s and e antigen/antibody in serum: a prospective study.
Taking advantage of the compulsory annual medical check-up at the Central Institute of Health, Japan National Railways, hepatitis B seromarkers were tested in male employees at work and their "dead and alive" status was followed for more than 6 years for their prognostic significance. Two prospective studies were carried out. In the first study, two groups (cohorts) of males age 40 to 55 years were tested in 1973 and 1978, respectively, for HBsAg and anti-HBs. The relative risk of dying from primary liver cancer in HBsAg-positive carriers (n = 126) as compared to the controls who were negative for both HBsAg and anti-HBs (n = 5,322) was 30.03 and significantly high, whereas those positive for anti-HBs (n = 1,470) had no increased risk of dying from primary liver cancer or from other liver diseases. The follow-up period ranged from 6.5 to 11.5 years, averaging 8.5 years. In the second study, three male cohorts of the same ages were tested for HBsAg and HBeAg/anti-HBe (micro-Ouchterlony method) in 1977, 1978 and 1979, respectively. There were 513 HBsAg-positive carriers among 25,547 examinees, who were followed for an average of 7.3 (6 to 8) years. Among these HBsAg carriers, those who were positive for HBeAg on entry had the highest risk of dying from primary liver cancer (relative risk, 50.25) and from other liver diseases (78.06), followed by those negative for both (28.95 and 21.78, respectively) and those positive for anti-HBe (9.47 and 6.43) when compared with 25,034 noncarriers.(ABSTRACT TRUNCATED AT 250 WORDS)
Hepatitis B Antibodies↗
Combination of intraoperative radiation with resection of cancer of the pancreas.
The utility of intraoperative radiation therapy (IORT) as an adjuvant to the surgical resection of pancreatic cancer was studied. In 1976, as our first trial with this combined therapy, we applied IORT with 30 Gy of electron beam with 8 MeV to 15 patients to prevent local recurrence around the celiac axis and superior mesenteric artery after standard pancreatectomy. However, the combined therapy did not show an improvement in survival rate as compared to that of 19 patients with standard operation alone. Autopsies of three patients with the combined therapy did not show involved lymph nodes in the radiation field, but did show local recurrence around the aorta outside the radiation field. By comparison, we performed extended operation without IORT on nine patients, with almost complete dissection of the lymph nodes around the aorta, from the diaphragm to the level of the inferior mesenteric artery. This extended surgery did not improve survival time, and autopsy showed local recurrence in spite of the dissection of lymph nodes. Therefore, since 1984, we have performed IORT with a dose of 30 Gy, 9 MeV, and an extended radiation field from the diaphragm above to the inferior mesenteric artery below, following extended operation on 14 patients. The five-year cumulative survival rate of these cases was 33.3%. Four autopsies showed improvement of local control rate. No radiation-related complications were noticed postoperatively in patients who underwent extended IORT following pancreatectomy. We were encouraged to continue this approach for the cure of pancreatic cancer.
Adult↗
A novel compound, 9-hydroxy-1-nitropyrene, is a major photodegraded compound of 1-nitropyrene in the environment.
1-Nitropyrene is a widely distributed environmental contaminant, but its fate in the environment remains unknown. 1-Nitropyrene in benzene exposed to sunlight was found to degrade rapidly, whereas 1-nitropyrene adsorbed on soot was stable and degraded at a rate of 42% in 40 d. The major degraded compound was identified as 9-hydroxy-1-nitropyrene, using nuclear magnetic resonance and gas chromatography/mass spectrometry. Concentrations of 9-hydroxy-1-nitropyrene were found to be between 15 and 23 pg/m3 in urban airborne samples. The mutagenic potency of 9-hydroxy-1-nitropyrene was much lower than that of 1-nitropyrene. We concluded that 1-nitropyrene in the environment is photodegraded into 9-hydroxy-1-nitropyrene to become a less mutagenic compound.
Adsorption↗
Evaluation of surgical risk in preoperative biliary drainage patients by blood chemistry laboratory data--with special reference to rate of reduction of serum bilirubin levels.
BACKGROUND/AIM: In Japan, it is generally accepted that biliary decompression should be performed before surgical operations on patients with obstructive jaundice. However, even when adequate decompression and effective reduction of serum bilirubin levels are achieved before surgical operations, it is not uncommon for unforeseen postoperative complications to occur. In this study, we analyzed the effectiveness of biliary drainage prior to pancreatoduodenectomy in patients with malignant obstruction of the papilla of Vater clinically manifested by obstructive jaundice. PATIENTS AND METHODS: We retrospectively examined the serial blood chemistry laboratory data of 44 patients with periampullary carcinoma who had preoperative obstructive jaundice and underwent pancreatoduodenectomy during the last 10 years. We divided the cases into three groups according to the rate of decrease in serum bilirubin levels, "b": group I, b <-0.09; group II, -0.09<b<-0.05; and group III, -0.05<b. There were no significant differences between the three groups in regard to sex, location of tumor and method of biliary decompression, however, there was significantly higher morbidity rate in group III. RESULTS: The level of biliary enzymes (gamma-GTP, ALP) tended to be higher in group I and lower in group III. Although TB and DB decreased to below 5 mg/dl before pancreatoduodenectomy in all three groups, transaminase levels instead rose in group III just before pancreatoduodenectomy. CONCLUSION: This suggested that liver damage continued to progress after biliary decompression when the reduction rate was low, and thus we should carefully monitor such patients for postoperative complications.
Aged↗