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Biomedical subjects

T Iwama

Publications and source records attributed to T Iwama.

At least 109 records · Page 6Linked to original sources
PubMed1994

Mortality in young first-degree relatives of patients with familial adenomatous polyposis.

BACKGROUND: Mortality and cancer deaths among young family members of patients with familial adenomatous polyposis (FAP) were investigated. METHODS: The subjects were 1764 members of 628 families with FAP registered at the authors' Polyposis Registry. They consisted of first-degree relatives of patients with FAP, excluding the propositus. These 1764 subjects were born between 1960 and 1978. Their survival times and causes of death were certified mainly by the National Family Registry and death certificates. Relative mortality rates were calculated based on the calendar year, age sex, and cause-specific death rate of Japanese people in the Vital Statistics, (Ministries of Health and Welfare, Japan. Vital statistics, Japan, Vol. 1960-1990. Tokyo: Statistics and Information Department, Minister's Secretariat, Ministry of Health and Welfare.) 1960-1990, Japan. RESULTS: There were 69 deaths before the age of 25 years. Deaths from malignant tumor were observed in 20 cases. Overall relative mortality rate in the subject group younger than age 20 years was 1.48. Relative cancer mortality in the age group between 1 and 4 years was significantly higher, because the relative mortality from hepatoblastoma in this age group was 176. Relative cancer mortality rate was significantly higher among males 15-19 years of age (15.4) and 20-24 years of age (male, 33.3; female, 150) due to colorectal cancer. CONCLUSIONS: Hepatoblastoma was a specific cancer in the 1- to 4-year-old age group in first-degree family members of patients with FAP. The incidence of colorectal cancer considerably increased, starting around the age of 20 years.

Adenomatous Polyposis Coli↗
PubMed1994

Double perfusion system for coronary angioplasty at the origin of the main vessel.

For the treatment of stenosis near the origin of either the left anterior descending artery or the left circumflex artery, one autoperfusion catheter was used to dilate the lesion while another was used to maintain perfusion of the nonstenosed vessel, which would normally suffer from a decrease in blood flow. This technique was applied to nine procedures in six patients. The balloon could be inflated for more than 60 sec in all cases. Satisfactory dilation was achieved without a significant decrease of systemic blood pressure during the procedure.

Angioplasty, Balloon, Coronary↗
PubMed1994

The significance of portal vein chemotherapy for liver micrometastases: an experimental study of a rat model.

To clarify the significance of prophylactic portal vein chemotherapy for hepatic metastases, the correlation between the timing of the portal infusion and the growth of liver micrometastases was examined in a rat model. Male Donryu rats weighing 160-180 g were first inoculated intraportally with 5 x 10(6) ascites hepatoma AH60C cells, following which an intraportal infusion of 5-fluorouracil (5-FU) 20 mg/kg/day with heparin 100 U/kg/day was given over 5 days, commencing on day 0, 3, and 6, in groups A, B, and C, respectively. Compared with a control group of rats which received no treatment, a significant inhibition of tumor growth and prolongation of survival time were observed in groups A (P < 0.01) and B (P < 0.05); however, group C, in which the mean diameter of the micrometastases was 0.52 +/- 0.10 mm at the commencement of the portal infusion, showed no therapeutic response. These results suggest that prophylactic portal vein chemotherapy should be given to prevent the lodgement of tumor cells in the portal system and inhibit their initial proliferation, rather than to destroy established micrometastases.

Animals↗
PubMed1994

Factors affecting the risk of rectal cancer following rectum-preserving surgery in patients with familial adenomatous polyposis.

PURPOSE: Rectum-preserving surgery is one of the most common surgeries for familial adenomatous polyposis (FAP). It is appropriate to analyze factors influencing risk of rectal cancer after rectum-preserving surgery in FAP patients. METHODS: Three hundred twenty-two patients with FAP (169 males, 153 females) who had undergone rectum-preserving surgery and were part of 1050 FAP patients registered at our FAP registry were included in the study. Postoperative survival was investigated and cause of death was elucidated from the death certificate or by inquiry to the hospitals that registered the patients. For risk analysis, log-rank tests were used. RESULTS: Forty-four cases developed invasive cancer within a mean interval of 119 months after surgery. Cumulative risk of rectal cancer was 24.2 +/- 7 percent (mean +/- limit of 95 percent confidence interval) at 15 years. Influencing risk factors for rectal cancer were a postoperative period over ten years or age over 44 years, a rectum longer than 7 cm, and dense polyposis. Other factors such as sex and cancer in the colon at initial surgery were not correlated with risk. CONCLUSION: The rectum may be reasonably preserved in patients with FAP when polyps in the rectum are sparse, ileorectal anastomosis is made on or below the peritoneal reflection, and patients continue having rectal examinations for life.

Adenomatous Polyposis Coli↗
PubMed1994

Pharmacological studies of platelet-activating factor (PAF)-induced augmentation of response to histamine in guinea-pigs.

An acute increase in airway response to histamine produced by platelet activating factor (PAF) was investigated pharmacologically in guinea-pigs. (1) The airway response to histamine (3 micrograms/kg) measured as pulmonary pressure was increased 8 min after injection of PAF at a dose of 25 ng/kg without affecting the numbers of leukocytes (macrophages, eosinophils, neutrophils and lymphocytes) in bronchoalveolar lavage fluid and airway capillary permeability. (2) To investigate the mechanism responsible for the PAF (25 ng/kg)-induced airway hyperresponsiveness to histamine, the effects of CV-3988 (a PAF-antagonist), ONO-1078 (a leukotriene (LT) antagonist), AA-861 (a 5-lipoxygenase inhibitor), indomethacin (a cyclooxygenase inhibitor), OKY-046 (a thromboxane A2 (TXA2) synthetase inhibitor) and S-1452 (a TXA2 receptor antagonist) were examined. Simultaneously, to investigate the direct antagonistic effects of these drugs on PAF-induced response, the effects of above agents on PAF (150 ng/kg) induced bronchoconstriction were examined. CV-3988 completely inhibited both reactions, while ONO-1078 and AA-861 had no effect on both reactions. OKY-046, S-1452 and indomethacin inhibited PAF-induced bronchoconstriction more potently than PAF-induced airway hyperresponsiveness. These results indicate that inflammatory response is not involved in the onset of PAF-induced acute airway hyperreactivity. Results also suggest that TXA2 but not LT may play a role in the onset of this airway hyperreactivity and the role of TXA2 in hyperreactivity is less important than in PAF-induced bronchoconstriction.

Animals↗
PubMed1994

Bombesin enhances experimental carcinogenesis induced in rat colon by 1,2-dimethylhydrazine.

The effects of bombesin on the colonic mucosa and on the incidence, number, size and histology of colon cancers induced by 1,2-dimethylhydrazine (DMH) were studied in Fischer 344 rats. In experiment 1, rats were randomized into three groups to receive either saline or bombesin (10 or 30 micrograms/kg body wt) to determine the labeling index of normal colonic mucosa. In experiment 2, rats were given 20 weekly injections of DMH (20 micrograms/kg body wt) and received either saline or bombesin (10 or 30 micrograms/kg body wt) every other day for 24 weeks. Administration of bombesin significantly increased the labeling indices of colonic mucosa in a dose-dependent manner. Chronic administration of bombesin at both dosages with DMH caused significant increases in the incidence, number and depth of involvement of colon cancers; however, it did not affect the size and histological type of colon cancers. In addition, bombesin at the dose of 30 micrograms/kg significantly increased the labeling index of colon cancer. These results suggest that bombesin stimulates the cell proliferation of colonic mucosa and colon cancer and enhances colon carcinogenesis in rats.

1,2-Dimethylhydrazine↗
PubMed1994

Emphysematous pyelonephritis successfully treated with nephrectomy and granulocyte colony-stimulating factor.

A 58-year-old woman developed diabetic ketoacidosis and emphysematous pyelonephritis caused by Escherichia coli. She was successfully treated with nephrectomy, antibiotics, and recombinant human granulocyte colony-stimulating factor (rhG-CSF). RhG-CSF therapy may be an effective adjunct for diabetic patients with severe infection, even when neutropenia is not present.

Anti-Bacterial Agents↗
PubMed1994

Indications for local excision of ampullary lesions associated with familial adenomatous polyposis.

BACKGROUND: The relative risk of periampullary carcinoma is high in patients with familial adenomatous polyposis (FAP). We examined the possibility of local treatment of the ampullary lesion of these patients in an early stage. STUDY DESIGN: From August 1991 to April 1993, 37 patients with FAP underwent endoscopic examination and biopsy of the ampulla. Local excision of the ampulla was performed in seven patients. RESULTS: Two of the seven patients were diagnosed with carcinoma in situ; the ages of the patients were 35 and 46 years. A 38-year-old woman had ampullary carcinoma infiltrating into the muscle of the sphincter of Oddi. These three cases showed a protruding change or deformity of the ampulla endoscopically. The laboratory data, cholangiogram, and abdominal ultrasonography were within normal limits. The superficial change of the ampulla along with the young age of the patients were considered to be factors that warranted further observation. Postoperative complications in two cases were treated successfully. CONCLUSIONS: Indications for local excision of the ampulla of patients with FAP would be protruding change of the ampulla, biopsy showing adenoma with severe atypia or carcinoma, in situ, no jaundice with or without subclinical abnormality of laboratory data, no apparent dilatation in the bile duct, and age of more than 35 years.

Adenomatous Polyposis Coli↗
PubMed1994

DNA alterations in cells from hereditary non-polyposis colorectal cancer patients.

To determine if the MCC, DCC or p53 gene is associated with susceptibility to hereditary non-polyposis colorectal cancer (HNPCC), these genes in normal cells from 12 HNPCC patients were analysed by polymerase chain reaction-single strand conformation polymorphism analysis. No changes which may alter the amino acid sequences of these genes were detected, suggesting that these genes are not associated with the susceptibility to HNPCC. Only one of nine HNPCC cancers showed mutations in the MCC and p53 genes on the same analysis. Loss of heterozygosity in chromosomes 5q, 17p, 18q and 22 was detected in four of the nine cancers, all of them being positive as to metastasis to lymph nodes. Abnormalities of the (CA)n repeat were found in six cancers, including all four without metastasis. These data indicate that tumor suppressor genes in chromosomes 5q, 17p, 18q and 22 are associated with the late stage of colorectal tumorigenesis in HNPCC, whereas the (CA)n repeat abnormalities are an early event of tumorigenesis and more essential to HNPCC.

Adult↗