Biomedical subjects

T Narisawa

Publications and source records attributed to T Narisawa.

At least 19 recordsLinked to original sources

PubMed1996

Inhibitory effects of natural carotenoids, alpha-carotene, beta-carotene, lycopene and lutein, on colonic aberrant crypt foci formation in rats.

Inhibitory effect of four carotenoids prevalent in human blood and tissues against the formation of colonic aberrant crypt foci was examined in Sprague-Dawley rats. They received three intrarectal doses of N-methylnitrosourea in weak 1, and a daily gavage of de-escalated doses of carotenoids during weeks 2 and 5. Lycopene, lutein, alpha-carotene and palm carotenes (a mixture of alpha-carotene, beta-carotene and lycopene) inhibited the development of aberrant crypt foci quantitated at week 6, but beta-carotene did not. The results suggested that lycopene and lutein in small doses may potentially prevent colon carcinogenesis.

Animals↗

PubMed1996

The retroperitoneal approach to aortoiliac surgery associated with a horseshoe kidney: report of a case.

The presence of a horseshoe kidney associated with aortoiliac vascular disease poses technical difficulties in terms of vascular reconstruction. The renal isthmus, position of the renal pelvis and ureters, and variable blood supply to the horseshoe kidney can complicate aortoiliac reconstruction. The left retroperitoneal approach provides excellent exposure of the abdominal aorta in patients with a horseshoe kidney without dividing the renal isthmus and avoids the risk of injury to a ureter in an anomalous position. We herein report the case of a patient with a horseshoe kidney who underwent a successful reconstruction of aortoiliac vascular disease using the left retroperitoneal approach.

Aged↗

PubMed1996

Chemoprevention by pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, of N-methyl-N-nitrosourea-induced colon carcinogenesis in F344 rats.

A potential chemopreventive action of pravastatin (Pr), a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, on colon carcinogenesis was evaluated in F344 rats. All rats at 7 weeks of age received an intrarectal dose of 2 mg of N-methyl-N-nitrosourea 3 times weekly for 2 weeks in experiment I (2 groups of 16 rats each), and for 3 weeks in experiment II (4 groups of 30 rats each). They were given drinking water containing 0 ppm (control) or 200 ppm Pr during weeks 1 to 40 in experiment I, and containing 0 ppm (control), 25 ppm, 5 ppm and 1 ppm Pr during weeks 4 to 40 in experiment II. The body weight gains, and food and water intakes were similar in all the groups. The incidence of colon carcinomas at termination of the experiment at week 40 was not different in the 200 ppm Pr and control groups in experiment I (63% vs. 69%), while it was significantly lower in the 25 ppm and 5 ppm groups, but not in the 1 ppm Pr group, compared with the control group in experiment II (50%, 48%, and 77% vs. 80%). This inhibitory effect of Pr against colon carcinogenesis was not related to the cholesterol-lowering effect of this agent. We postulate that Pr inhibits the promotion stage of colon carcinogenesis, perhaps through modulation of cholesterol synthesis in situ in the colonic mucosa, thereby suppressing farnesyl isoprenylation of growth-regulating proteins such as p21 ras.

Animals↗

PubMed1996

[A case of the giant and pedunculated thrombus formation in the left atrium with normal mitral valve].

Occurrence of thrombus formation in the left atrium is rare without accompanying abnormalities at the mitral valve. Only a few cases of giant and pedunculated thromboses in the left atrium have been reported in the Japanese literatures. This is a case report of giant thrombus in the left atrium treated surgically. Patient was 61 years old male suffering from palpitation. Physical examination of the heart revealed increased first sound and diastolic rumbling at the apex. ECG revealed atrial fibrillation and LVH. Echocardiography and chest CT demonstrated a huge tumor like mass in the left atrium attached to the septal area. There were no abnormalities found at mitral valvular structures or motion. Catheterization studies revealed no disturbance of valvular functions. Angiographic examination demonstrated smooth surfaced tumor mass occupied left atrium. Coronary angiography revealed significant stenosis in segments 6, 7, 9, 12 and 14. Prior to surgery, patient was diagnosed myxoma of the left atrium and ischemic heart disease. Removal of the mass and CABG were carried out at a same time. Pathology revealed giant and pedunculated globular thrombus. Contributional factors possibly growing of such huge thrombus formation explained resulting from atrial fibrillation and decreased contractile force of the hypertrophied ventricle.

Heart Atria↗

PubMed1995

The effects of dietary fiber from Lagenaria scineraria (yugao-melon) on colonic carcinogenesis in mice.

BACKGROUND: The increasing trend of colon cancer in Japan is attributed to changes in dietary habits, that is, increased amounts of fat and decreased amounts of fiber in the diet. The effects of Japanese dietary fiber from Lagenaria scineraria (yugao-melon) on colonic carcinogenesis in mice were examined. METHODS: Eighteen ICR mice in each group were fed with either a basal diet or a diet containing 5%, 10%, or 20% of yugao powder for 35 weeks. All the mice received a weekly intraperitoneal injection of 1,2-dimethylhydrazine (DMH), 10 mg/kg body weight for 10 weeks. The effects of yugao powder on the mucosal and luminal variables involved in colonic carcinogenesis were then compared with those of wheat bran in the mice without any carcinogen treatment. RESULTS: The incidence of colon tumors (adenocarcinomas) was lower in the yugao powder diet groups than in the basal diet group at week 35 (24% vs. 50%, P < 0.05). The bile acid concentration in the colon was reduced in all the fiber diet groups except for the 5% yugao powder diet group. The colonic luminal pH acidified as yugao powder contents also increased in the yugao powder diet groups. The findings on the colonic short chain fatty acids, microflora, and mucosal fatty acids and ornithine decarboxylase activity were all inconsistent with a tendency to either develop or to inhibit carcinogenesis in both the fiber diet groups. CONCLUSIONS: Dietary fiber from yugao-melon suppressed DMH-induced colonic carcinogenesis in mice by lowering the bile acid concentration and pH in the colon. The results of the luminal and mucosal variables examined also suggested that the mechanisms of action of yugao powder against colonic carcinogenesis differed from those of wheat brain.

Adenocarcinoma↗

PubMed1995

[A case of extirpation of the extrapleural plombs].

A 75-year-old male, who had undergone left extrapleural plombage for left pulmonary tuberculosis 46 years before, was admitted because of cough and sputum. The Chest X-ray and CT-scan films on admission show fluid collection in plombs. Left postero-lateral thoractomy was performed on January 14, 1994. There were thickness of the parietal pleura and no findings of empyema or fistulas. Extrapleural plombs and partial part of the vegetation were removed safely. There were two damaged plombs and fluid collection in another two plombs. No findings of residual tuberculosis were found on postoperative pathological and bacteriological examinations. He has been well for 8 months postoperatively.

Aged↗

PubMed1995

[Coronary artery disease in patients with abdominal aortic aneurysm].

To evaluate the influence of coronary artery disease (CAD), we reviewed 102 patients who underwent elective repair of abdominal aortic aneurysm (AAA) between 1982 and 1992. Prior to surgery, all patients underwent clinical evaluation for the presence of CAD including dipyridamole thallium scintigraphy. They were classified into the following groups: Group I (n = 66), no clinical evidence of CAD; Group II (n = 26), clinical evidence of stable CAD; Group III (n = 10), unstable CAD. Coronary angiography (CAG) was performed in group II and group III patients only. All patients in group I and group II underwent elective repair of their AAA without coronary revascularization. Eight patients in group III underwent CABG followed by elective AAA repair within two months. One of two patients who had impending ruptured AAA underwent combined CABG and AAA repair as a single operation and the other underwent AAA repair followed by CABG. One case of perioperative myocardial infarction occurred in group II, but there was no early postoperative death related to cardiac disease in group I and II. In group III, however one patient who underwent combined surgery died of low-output syndrome in the early postoperative period, no death or myocardial infarction occurred following staged operation in the other nine patients. This present results support the contention that CAG is not necessary in all AAA patients, and that they can be managed according to appropriate risk by a selective approach based upon clinical assessment of their CAD. It is also apparent that a staged operation can be performed very safely in patients with unstable CAD.

Adult↗

PubMed1994

Colon cancer prevention with a small amount of dietary perilla oil high in alpha-linolenic acid in an animal model.

BACKGROUND: Epidemiologic and experimental studies suggest that dietary fish oil and vegetable oil high in omega-3 polyunsaturated fatty acids (PUFAs) suppress the risk of colon cancer. The optimal amount to prevent colon carcinogenesis with perilla oil high in omega-3 PUFA alpha-linolenic acid in a 12% medium-fat diet was investigated in female F344 rats. For comparison, safflower oil high in omega-6 PUFA linoleic acid was used. METHODS: Thirty or 25 rats at 7 weeks of age in each group received an intrarectal dose of 2 mg N-methyl-N-nitrosourea 3 times weekly in weeks 1 and 2 and were fed the diets with various levels of perilla oil and safflower oil throughout the experiment. RESULTS: The incidence of colon cancer at the termination of the experiment at week 35 was 40%, 48% and 32% in the rats fed the diets with 3% perilla oil plus 9% safflower oil, 6% perilla oil plus 6% safflower oil, and 12% perilla oil plus 0% safflower oil, respectively, whereas it was 67% in the rats fed the control diet with 0% perilla oil plus 12% safflower oil. The amount of diet consumed and the body weight gain were identical in all of the dietary groups. The ratios of omega-3 PUFA to omega-6 PUFA in the serum and the colonic mucosa at week 35 were increased in parallel to the increased intake of perilla oil. CONCLUSIONS: The results suggest that a relatively small fraction of perilla oil, 25% of total dietary fat, may provide an appreciable beneficial effect in lowering the risk of colon cancer.

Animals↗

PubMed1994

Prevention of 1,2-dimethylhydrazine-induced colon tumorigenesis by HMG-CoA reductase inhibitors, pravastatin and simvastatin, in ICR mice.

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin (Pr) and simvastatin (Si), suppressed 1,2-dimethylhydrazine (DMH)-induced colon cancer development in female ICR mice. All mice received an i.p. injection of 10 mg DMH/kg body wt once weekly for 15 weeks. Pr was administered at 0.01, 0.005 and 0.001% levels in drinking water, and Si at 0.01 and 0.002% levels in the diet. All animals had access to Pr or Si throughout the experiments which were terminated at weeks 25 or 30. Histologically most of the tumors were well-differentiated adenocarcinomas. The incidence of colon tumors examined at weeks 25 or 30 was reduced by 67% in the 0.01% Pr group, by 30% in the 0.005% Pr and 0.01% Si groups, and by 24% in the 0.001% Pr and 0.002% Si groups, compared with their respective controls. However, the differences did not reach statistical significance. The number of tumors per mouse was significantly reduced in all groups administered Pr and Si except the 0.001% Pr group as compared to their respective controls. The results from those three independent experiments seem to suggest that HMG-CoA reductase inhibitors may prevent colon tumorigenesis in laboratory animal model.

1,2-Dimethylhydrazine↗

PubMed1994

[Dissecting aortic aneurysms that occurred in aged brothers without Marfan syndrome].

The occurrence of familial dissecting aortic aneurysms without Marfan syndrome is rare. This report describes two aged siblings who underwent successful surgery for this disease. Neither patient had the clinical features of Marfan syndrome, and both had histories of systemic hypertension. Case 1: A 76-year-old man had dissecting aortic aneurysm, DeBakey type IIIa, which was localized and had multiple lumina with thrombi. Case 2: A 71-year-old man (younger brother of case 1) had retrograde dissecting aortic aneurysm, DeBakey type IIIa. Histological examinations of the aortae showed cystic medial necrosis in both cases, and also showed atherosclerotic changes in case 1. These two siblings had no familial history of cardiovascular incidents and were much older than previously reported cases. Therefore it may be possible that the dissecting aortic aneurysms of these two cases occurred coincidently rather than due to hereditary factors.

Aged↗

PubMed1994

[Asymptomatic bilateral spontaneous pneumothorax].

Two surgical cases of bilateral pneumothorax founded at a medical examination were reported. Case 1; A 15-year-old male was admitted to our hospital pointed out left spontaneous pneumothorax without complaints. The interval between the first and the contralateral pneumothorax was 3 weeks. He was treated with a one-stage operation through a bilateral axillary incision. Case 2; A 19-year-old male was admitted to our hospital pointed out left spontaneous pneumothorax without complaints. Surgical operation was performed with a left axillary incision. One year after the treatment, he was pointed out right spontaneous pneumothorax on his chest X-ray film. Partial resection of the right lung was performed with a right axillary incision. Of the 261 pneumothorax patients, 28 had bilateral pneumothorax in our hospital. The majority of these patients had complaints which were chest pain, dyspnea and cough. Of the 28 patients, 2 had no complaints at the time of admission. We conclude that we have to follow up carefully the patients with hemilateral spontaneous pneumothorax.

Adolescent↗

PubMed1994

[Coronary artery bypass grafting to total occlusion of all three coronary vessels].

We studied total occlusion of all three coronary arteries. From 1975 to 1992, a total of 4,100 patients underwent coronary arteriography at Show University Hospital. Of these, four patients (0.1%) had complete occlusion of all three coronary arteries and all of them underwent coronary artery bypass grafting (CABG). The mean numbers of coronary risk factors were only 2.3 but history of angina of effort were long-standing such as 4 to 29 years (mean 16.3 yr). All cases had previous episodes of myocardial infarction. Three cases (75%) had aortic aneurysm. One case was also diagnosed as Leriche syndrome besides coexisting aneurysm. Coronary arteriogram showed total occlusion of right coronary artery, left anterior descending artery and left circumflex artery in the segment of 1.6 or 7 and 11 respectively. All cases had intracoronary anastomosis and intercoronary anastomosis. Among 12 occluded coronary arteries of all four cases, 11 were distally visualized with contrast medium via collateral flow but good opacification of the distal coronary trees were not seen. Also proper assessments of cardiac performance including viability of myocardium were not established because all cases were in the state of C.C.S grades IV. But significant clinical recovery were obtained in all cases after CAGB of three or four bypass. We conclude that these results might be a useful suggestion for the treatment of total occlusion of all three coronary arteries.

Aged↗

PubMed1993

A very low dose of green tea polyphenols in drinking water prevents N-methyl-N-nitrosourea-induced colon carcinogenesis in F344 rats.

The effect of tea polyphenols, major constituents of tea, on colon carcinogenesis was investigated. A total of 129 female F344 rats were given an intrarectal instillation of 2 mg of N-methyl-N-nitrosourea 3 times a week for 2 weeks, and received a water solution of green tea extract (GTE) as drinking water throughout the experiment. Autopsies at week 35 revealed significantly lower incidence of colon carcinomas in rats ingesting 0.05%, 0.01% or 0.002% GTE solution than in controls ingesting 0% GTE solution: 43%, 40% and 33% vs. 67%. The data suggest that GTE, even at a very low dose (0.002% solution), has a potent inhibitory effect on colon carcinogenesis.

Animals↗

PubMed1993

[Single selective cerebral perfusion for aortic arch replacement].

The patients underwent aortic arch replacement for aneurysmal disease from 1988 to 1993 using a simplified cardiopulmonary bypass (CPB) technique with single selective cerebral perfusion (single SCP). Recently cold cerebral perfusion technique was also used. In order to study the effect of this technique, we monitored bilateral carotid artery pressure, blood oxygen saturation of jugular vein and brain oxygenation by near infrared spectroscopy during CPB. Of the ten patients with arch aneurysm, five had urgent operation for ruptured aneurysm. The cold single SCP was accomplished by perfusion to the right axillary artery using separate pump and separate heat exchanger (flow 10-15 ml/kg/min, pressure 40-60 mmHg, perfusion temperature under 12 degrees C) under the low CPB flow (1,000-1,500 ml/min), moderate systemic cooling (23-25 degrees C) and retro-grade cardioplegia. There were no strokes caused by this technique. This simplified technique of cold single SCP was simple and attractive method, provide satisfactory cerebral protection.

Aged↗

PubMed1992

Cell kinetic analysis of the mucosal epithelium and assay of ornithine decarboxylase activity during the process of 1-hydroxyanthraquinone-induced large bowel carcinogenesis in rats.

Cell kinetics and activity of ornithine decarboxylase (ODC) were studied during the process of 1-hydroxyanthraquinone (1-HA)-induced intestinal carcinogenesis in rats. Starting at 6 weeks of age, a total of 37 male ACI/N rats were divided into two groups and treated as follows: group I (18 rats) received diet containing 1% 1-HA for 12 months; group II (19 rats) was given the basal diet alone. Sub-groups of 5-7 rats were sequentially killed at 4, 8 and 12 months for evaluation of the length, cell numbers and 5-bromo-2'-deoxyuridine (BrDU) labeling indices of large bowel crypts together with ODC activity. All kinetic and ODC data indicated increased DNA synthesis and proliferation at all time points. Morphological observation of the intestines also revealed melanosis, crypt abscesses and erosion, becoming more pronounced with length of exposure to the anthraquinone. The data thus suggest that cell proliferation in the crypts of the cecum or colon is important for 1-HA-induced intestinal carcinogenesis.

Animals↗

PubMed1992

Inhibitory effect of cryptoporic acid E, a product from fungus Cryptoporus volvatus, on colon carcinogenesis induced with N-methyl-N-nitrosourea in rats and with 1,2-dimethylhydrazine in mice.

The antitumorigenic effect of cryptoporic acid E (CPA-E), a dimeric drimane sesquiterpenoid isolated from the fungus Cryptoporus volvatus, on colon carcinogenesis was investigated. Female F344 rats given an intrarectal instillation of 2 mg of N-methyl-N-nitrosourea 3 times weekly in weeks 1 and 2 were fed diet containing 0.2% CPA-E from week 3. Female ICR mice given 15 weekly intraperitoneal injections of 10 mg of 1,2-dimethylhydrazine/kg body weight during weeks 1 to 15 were fed diet containing 0.06% CPA-E from week 1. The experiment was terminated at week 35 for rats and at week 25 for mice. The incidence and the number of tumors per animal were reduced in CPA-E-fed animals compared to the controls: 31% vs. 75% (P less than 0.05) and 0.4 +/- 0.2 (SEM) vs. 0.9 +/- 0.2 (0.1 greater than P greater than 0.05) in rats, and 31% vs. 63% (0.1 greater than P greater than 0.05) and 0.4 +/- 0.2 vs. 2.4 +/- 0.8 (P less than 0.05) in mice (16 animals in each group). Intrarectal deoxycholic acid-induced colonic mucosal ornithine decarboxylase activity was significantly lowered in CPA-E-fed animals compared to controls. This shows an antipromoting activity of CPA-E against colon carcinogenesis. Thus, it was concluded that CPA-E inhibits colon cancer development in both rats and mice treated with 2 different colon carcinogens.

1,2-Dimethylhydrazine↗

PubMed1991

Clinical observation on the association of gallstones and colorectal cancer.

A possible association between gallstones, colorectal cancer, and gastric cancer was investigated. The age distribution and mean age of the two cancer groups were identical. The incidence of gallstones in 378 colorectal cancer cases and 869 gastric cancer cases was 7.1% and 5.5%, respectively. Of colorectal cancer cases, 33 cases with multiple carcinomas had a significantly higher gallstone incidence than cases with a solitary carcinoma--24.2% and 5.5%, respectively. The mean age was 5 years older in gallstone cases than in those without gallstones in both cancer groups, and it was 4 years older in multiple-carcinoma cases than in solitary-carcinoma cases in the colorectal cancer group. These results suggest that the higher levels of same causative factors (i.e., dietary fat) are associated with a longer duration of gallstone formation and colorectal cancer development as demonstrated by multiple colorectal-carcinoma cases.

Adenocarcinoma↗

PubMed1991

Liver abscess as the initial manifestation of colonic Crohn's disease: report of a case.

Liver abscess is a rare complication of Crohn's disease and in most of the reported cases, the diagnosis of Crohn's disease preceded that of liver abscess. We report herein a case in which a liver abscess was the initial clinical manifestation of Crohn's disease in a 36 year old man who presented with high fever and weakness. The diagnosis of liver abscess was established by abdominal ultrasonography, computed tomography and an arterial blood culture. The abscess was resolved with antibiotic therapy alone and during the drug therapy, a barium enema examination was performed which revealed a stricture at the transverse colon. Resection of the transverse colon was performed and macroscopic and microscopic examination of the resected specimen established the diagnosis of Crohn's disease. The liver abscess was thus speculated to be secondary to the inflamed bowel. Although rare, Crohn's disease should be included in the differential diagnosis of diseases causing liver abscess.

Adult↗