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Biomedical subjects

Y Tada

Publications and source records attributed to Y Tada.

At least 145 records · Page 8Linked to original sources
PubMed1998

Cancer inhibition by green tea.

Green tea is now an acknowledged cancer preventive in Japan. This paper discusses several important features of (-)-epigallocatechin gallate (EGCG), the main constituent of green tea and tea polyphenols. EGCG and other tea polyphenols inhibited growth of human lung cancer cell line, PC-9 cells with G2/M arrest. 3H-EGCG administered by p.o. intubation into mouse stomach revealed that small amounts of 3H-activity were found in various organs where EGCG and green tea extract had previously demonstrated their anticarcinogenic effects, such as skin, stomach, duodenum, colon, liver, lung and pancreas. Cancer onset of patients who had consumed over 10 cups of green tea per day was 8.7 years later among females and 3.0 years later among males, compared with patients who had consumed under three cups per day. The mechanisms of action of EGCG were briefly discussed with regard to inhibition of tumor necrosis factor-alpha (TNF-alpha) release.

3T3 Cells↗
PubMed1998

The response of blood flow between the internal thoracic and ileocecal arteries to inotropic agents in a canine model.

The pharmacologic response of coronary artery bypass conduits is of great importance. This study was designed to clarify the response of blood flow between the internal thoracic artery (ITA) and the ileocecal artery (ICA) to inotropic agents. The responses of the ITA and ICA to epinephrine, dopamine, isoproterenol, and dobutamine were examined by collecting free-flowing blood from a canine model. There were no significant differences in the response to inotropic agents between the ITA and the ICA. Epinephrine and dopamine increased the graft flow, whereas isoproterenol and dobutamine decreased the graft flow percentages of the cardiac output. These results suggest that the flow response to inotropic agents is equivalent in canine ITA and ICA grafts.

Animals↗
PubMed1998

Rapid data acquisition protocol in ECG-gated myocardial perfusion SPECT with Tc-99m-tetrofosmin.

Into 25 patients with heart disorders, 99mTc-tetrofosmin 555-740 MBq was injected intravenously at rest. After 40 minutes, ECG-gated myocardial perfusion SPECT was performed with a two detector gamma camera VERTEX (ADAC), setting up two detectors to form a 90-degree angle. Sixteen frames per R-R interval were acquired during a 180 degree rotation from the RAO 45 degrees to the LPO 45 degrees. A pair of data sets with standard (SDA) and rapid data acquisition (RDA) protocols was collected. In an SDA protocol, SPECT imaging was performed for 50 sec per step in 5 degree angular steps (total acquisition time; 15 minutes). An RDA protocol was conducted with 12 sec per step, 6 degree angular steps (acquisition time, 3 minutes). LVEF (%) and LVEDV (ml) quantitated automatically with a QGS program showed excellent correlations between two protocols with correlation coefficients of 0.980 (p < 0.01) and 0.983 (p < 0.01), respectively. Subsequently visual assessment of regional wall motion based on a four-point grading system was carried out with a 3-D cine LV display. High complete agreement was gained with 158 (90.3%) out of total 175 segments, so that assessment of the global and regional LV function with the RDA protocol demonstrated high reliability and feasibility.

Electrocardiography↗
PubMed1998

A comparison of prosthetic materials used to repair abdominal wall defects.

Large abdominal wall defects may require a prosthesis for closure. The aim of our study was to identify the best material for abdominoplasty in pediatric patients. One hundred twenty-eight Wistar KY strain male rats (3 weeks old) were used. All animals underwent celiotomy via a midline skin incision. They were divided into seven groups as follows: the animals in groups 1 through 6 underwent full-thickness abdominal wall excision 3 cm in diameter. The animals in group 1 underwent primary closure. In groups 2 through 6 the defect was closed with prosthetic material. In Group 7, a sham operation was performed. Daily weights were measured. The animals were killed after 3 and 9 weeks. Adhesion scores were assigned for each group. Vicryl mesh resulted in the fewest adhesions and had no effect on weight gain in the developing rats.

Abdominal Muscles↗
PubMed1998

Thoracotomy for a patient with Stevens-Johnson syndrome: report of a case.

Stevens-Johnson syndrome (SJS) is an uncommon eruptive disorder of the skin and mucous membranes with systemic manifestation. It is extremely unusual for patients with a past history of SJS to present with indications for surgery necessitating thoracotomy. We describe herein the perioperative management of a patient with SJS who underwent surgery for a spontaneous pneumothorax.

Female↗
PubMed1998

Abdominal aortic aneurysm repair with arterial branch reconstruction: utility of the temporary bypass technique.

Between June 1992 and May 1996, five patients underwent an abdominal aortic aneurysm (AAA) repair with concomitant arterial branch reconstruction. All of the patients were males ranging in age from 55 to 66 years (mean: 61.6 years). The operations were performed for a localized abdominal aortic dissection, a pseudoaneurysm after patch angioplasty of a supraceliac AAA, a pararenal AAA, a total AAA with retrograde descending thoracic aortic dissection, and a supraceliac AAA after an infrarenal AAA repair. All patients underwent bilateral renal artery (RA) reconstruction. Three patients also had a concomitant reconstruction of the superior mesenteric artery ad celiac axis. The renal arteries were preferentially reconstructed. Visceral circulation during aortic cross-clamping was maintained via a temporary bypass circuit. A temporary division of the left renal vein was necessary in two patients. Overall, the mean renal ischemia time was 17.2min (range: 10 to 32 min). There was one perioperative death due to sepsis from a graft infection. Another patient died 6 months postoperatively due to pyothorax. One patient required postoperative hemodialysis for 1 month. Based on the above findings, the temporary bypass technique is thus considered to be useful for maintaining physiologic organ perfusion during aortic clamping without the need to use any complicated devices.

Aged↗
PubMed1998

Aortoesophageal fistula: report of an unusual case.

We report herein the case of a patient with an aortoesophageal fistula (AEF) who was managed successfully by surgery. A 5-mm oval, well circumscribed aortic perforation just above the orifice of the celiac axis and a 4-mm defect in the esophagus were primarily closed, and an omental flap was placed between the aorta and the esophagus. No definite etiology could be determined. Our experience of this case suggests that primary closure for defects in both the aorta and the esophagus is the best option when the defects are small, and that the possibility of an AEF must be considered in patients with midthoracic pain or hematemesis, even if there is no history of thoracic aortic aneurysm, foreign body ingestion, trauma, or esophageal disease.

Adult↗
PubMed1998

Therapeutic and diagnostic potential of a vasopressin-2 antagonist for impaired water handling in cirrhosis.

OBJECTIVE: Progressive cirrhosis is associated with increasing difficulty to handle free water. We examined the therapeutic potential of an orally active nonpeptide vasopressin-2 receptor antagonist (OPC-31260) in the management of edema and ascites in patients with cirrhosis. By means of its chemical blockade of the vasopressin-2 receptor in the kidney, we also assessed the ability of renal water handling in the early stage of cirrhosis. METHODS: A single 30 mg dose of OPC-31260 was administered orally to eight biopsy-proven patients with cirrhosis who had ascites or peripheral edema. The aquaretic responses were compared with those in six healthy subjects. RESULTS: In the patients with cirrhosis, OPC-31260 significantly (p < 0.01) increased the urinary excretion rate at 0 to 2 hours, and significantly (p < 0.01) lowered urine osmolality at 2 to 4 hours after administration. Free water clearance increased from -0.48 +/- 0.14 to +0.19 +/- 0.21 ml/min (p < 0.05) at 0 to 4 hours after administration. However, these aquaretic responses in the patients with cirrhosis were only approximately half the responses observed in the healthy subjects. A significant (p < 0.05) inverse relationship was observed between indocyanine green retention at 15 minutes after administration and the maximal free water clearance after administration to the patients with cirrhosis. Urinary sodium excretion did not change significantly in the patients, whereas it increased twofold in the healthy subjects. Urinary vasopressin excretion tended to increase in the patients, whereas it increased twofold to threefold (p < 0.01 to 0.05) from the baseline in the healthy subjects. Urinary prostaglandin E2 excretion was not increased, and serum sodium and plasma vasopressin levels were elevated only slightly in both groups. CONCLUSIONS: Even though a hyporesponsiveness was observed in the group of patients with cirrhosis compared with the healthy group, the novel vasopressin-2 antagonist induced hypotonic diuresis in patients with cirrhosis, suggesting a therapeutic potential in managing water excess. This drug response may be a new index to assess impairment of water handling in patients with cirrhosis.

Administration, Oral↗
PubMed1998

Cimetidine reduces impairment of cellular immunity after cardiac operations with cardiopulmonary bypass.

OBJECTIVE: Depressive effects of cardiopulmonary bypass on cell-mediated immune responses may lead to postoperative infectious complications. We previously reported that cimetidine reduced postbypass depression of the cytotoxic activity of natural killer cells. This study evaluated cimetidine as an agent to preserve cellular immunity after cardiac operations. METHODS: In a prospective randomized study, 20 patients were divided into two groups of equal size. Cimetidine-group patients received 400 mg of cimetidine intravenously before bypass and a 33 mg/hr intravenous infusion of cimetidine after the operation, continuing until the fifth postoperative day. Control-group patients received conventional perioperative therapy. Lymphocyte subsets, natural killer cell activity, percentage of CD56+CD16+ (percentage of natural killer cells), and percentage of CD11b+CD8+ (percentage of suppressor T lymphocytes) were measured perioperatively. RESULTS: Although temporary postoperative reductions in percentages of CD3+, CD4+, and CD56+CD16+ cells were observed in both groups, CD8+ percentages on postoperative day 1 and CD11b+CD8+ percentages on postoperative days 1 and 3 in the cimetidine group were significantly lower compared with those in the control group (p = 0.01,p = 0.004, andp = 0.02, respectively). Temporary postoperative reduction of natural killer cell activity was also observed in both groups, but the natural killer cell activity on postoperative day 1 in the cimetidine group (17.1%) was significantly higher (p = 0.02) than that in the control group (8.20%). CONCLUSIONS: Cimetidine counteracts depressive effects of cardiopulmonary bypass on cell-mediated immunity and may possibly reduce postoperative susceptibility to infection.

Antigens, CD↗
PubMed1998

Phosphorylation of influenza C virus CM2 protein.

Labeling of influenza C virus-infected HMV-II cells with [32P]orthophosphate showed that the CM2 protein is posttranslationally modified by phosphorylation. The unglycosylated form of CM2 synthesized in the presence of tunicamycin was found to be highly phosphorylated. This result, together with the finding that digestion of CM2 with peptide-N-glycosidase F failed to remove the 32P label from the glycosylated form of CM2, indicated that phosphorylation occurs in the polypeptide backbone and not in the oligosaccharide chain. Furthermore, phospho-amino acid analysis revealed that phosphorylation occurs exclusively on serine residues. Treatment of infected cells with brefeldin A resulted in a complete inhibition of phosphorylation, showing that phosphorylation of CM2 occurs after its migration from the endoplasmic reticulum to the Golgi apparatus. Phosphorylation of CM2 was also inhibited strongly, although not completely, by monensin treatment, suggesting that CM2 is phosphorylated predominantly after its movement from medial to trans Golgi cisternae. Finally, we found that the CM2 protein incorporated into the progeny virion is phosphorylated, which indicates that there is no strictly selective incorporation of the unphosphorylated form of CM2 into the virion.

Animals↗
PubMed1998

Anastomotic aneurysms after surgical treatment of Takayasu's arteritis: a 40-year experience.

PURPOSE: To evaluate the clinical characteristics of anastomotic aneurysms that develop in surgically treated patients with Takayasu's arteritis. METHODS: Among 103 patients with Takayasu's arteritis treated surgically over 40 years, 91 patients with 259 anastomoses (allowing for exclusion of 12 operative deaths) participated in follow-up study from 1 month to 37.3 years with a mean value +/- SEM of 17.3 +/- 1.1 years with a follow-up completion rate of 93% at 30 years. The clinical characteristics of anastomotic aneurysms were clarified, and the influences of several factors (sites of anastomoses, occlusive or aneurysmal disease, suture material, preoperative systemic inflammation, and administration of corticosteroids) on formation of anastomotic aneurysms were analyzed by means of life-table method and Cox regression analysis. RESULTS: Twenty-two uninfected anastomotic aneurysms were found among 14 patients (22 of 259 anastomoses, 8.5%). The interval between the previous operation and diagnosis varied from 1.6 to 30 years with a mean value +/- SEM of 9.8 +/- 1.8 years. The cumulative incidence of anastomotic aneurysm at 20 years was 12.0%. Systemic inflammation or steroid administration had little influence on formation of anastomotic aneurysm. Instead, anastomotic aneurysm tended to occur after operations for aneurysmal lesions. CONCLUSIONS: Anastomotic aneurysm can occur anytime after operations for Takayasu's arteritis. The development of anastomotic aneurysm is not influenced by any factor specific to this disease except the presence of an aneurysmal lesion.

Adolescent↗
PubMed1998

Nondissection method for tibial bypass surgery using Esmarch's rubber bandage or an automatic sequential pneumatic tourniquet: long-term results.

It is suspected that operative injury to the native arteries during a vascular bypass procedure causes periarterial fibrosis contributing to late graft failure. A a nondissection method for tibial artery bypass has been developed using Esmarch's rubber bandage or an automatic sequential pneumatic tourniquet. This retrospective study examined patency and other late results in distal bypass operations using the nondissection method. Between June 1982 and July 1995, 78 tibial bypasses were performed using reversed autogenous saphenous vein grafts in 70 patients (57 men, 13 women; mean age 57.4 years). Graft patency was assessed angiographically. When a stenotic lesion was recognized, the graft was revised and considered an assisted primary patency. Primary patency rates at 1, 3, 5, and 10 years were 82.8%, 75.3%, 63.4% and 63.4%, respectively, by life-table analysis. Six grafts required revision for stenosis; one involved distal anastomotic stenosis. As a result, assisted primary patency rates resembled secondary patency rates of 87.7%, 84.3%, 80.3%, and 80.3% at the same respective intervals. In conclusion, the nondissection method improved long-term patency by preventing late distal anastomotic stenosis.

Arterial Occlusive Diseases↗
PubMed1998

Wide distribution of [3H](-)-epigallocatechin gallate, a cancer preventive tea polyphenol, in mouse tissue.

The increasing recognition of green tea and tea polyphenols as cancer preventives has created a need for a study of their bioavailability. For this purpose, we synthesized [3H] (-)-epigallocatechin gallate ([3H]EGCG) with a specific activity of 48.1 GBq/mmol and directly administered the solution into the stomachs of CD-1 female or male mice. Radioactivity in the digestive tract, various organs, blood, urine and feces was measured with an oxidizer at various times after administration and significant radioactivity was found in the previously reported target organs of EGCG and green tea extract (digestive tract, liver, lung, pancreas, mammary gland and skin), as well as other organs (brain, kidney, uterus and ovary and testes) in both sexes. Incorporation of radioactivity in the cells was confirmed by microautoradiography. Within 24 h, 6.6 (females) and 6.4% (males) of total administered radioactivity was excreted in the urine and 37.7 and 33.1% in feces. HPLC analysis of urine from both sexes revealed that 0.03-0.59% of administered [3H]EGCG, along with at least five metabolites, was excreted. In addition, we found that a second, equal administration to female mice after a 6 h interval enhanced tissue levels of radioactivity in blood, brain, liver, pancreas, bladder and bone 4-6 times above those after a single administration. These results suggest that frequent consumption of green tea enables the body to maintain a high level of tea polyphenols and this paper is the first pharmacological evidence of a wide distribution of [3H]EGCG in mouse organs, indicating a similar wide range of target organs for cancer prevention in humans.

Animals↗
PubMed1998

Identification of a 374 amino acid protein encoded by RNA segment 6 of influenza C virus.

Unspliced mRNA from RNA segment 6 of influenza C virus contains a single open reading frame that potentially encodes a polypeptide of 374 amino acids. This polypeptide, which has not been identified as yet, is predicted to contain the complete amino acid sequence of the matrix protein, M1, as well as that of a small integral membrane protein, CM2. Here, we found that small amounts of two previously unrecognized proteins with apparent molecular masses of 42 (P42) and 44 kDa (P44) were immunoprecipitated with immune serum against CM2. The electrophoretic mobilities of P42 and P44 varied depending on virus strain, indicating that they are virus-coded. Treatment of infected cells with tunicamycin and digestion of immunoprecipitated proteins with various endoglycosidases revealed that P42 is modified by the addition of a high-mannose oligosaccharide chain to generate P44. A monoclonal antibody against M1, like anti-CM2 serum, was able to immunoprecipitate both the P42 and P44 proteins. Furthermore, the tryptic peptide map of either P42 or P44 was indistinguishable from the map of the mixture of M1 and CM2. These results, taken together, suggest strongly that P42 and P44 correspond to the 374 amino acid protein encoded by unspliced RNA segment 6 mRNA and its N-glycosylated form, respectively.

Animals↗
PubMed1998

Trapping of secreted molecules at single-cell level using an HPLC resin particle under a videomicroscope.

Particles of HPLC resins are used for the trapping of secreted molecules from a single cell. The basic molecules, e.g., histamine, are secreted from a single RBL-2H3 cell by granule exocytosis and are trapped by cation-exchange HPLC resins outside the cell. Since quinacrine is concentrated into the exocytotic and acidic microgranules in RBL-2H3 cells, which are used as a model cell line of mast cells, we measured the change in the fluorescence intensity of the quinacrine released from the cells and that of molecules trapped on the resin using a videomicroscope. By measuring the increase in the fluorescence intensity of the resins, we can estimate the real time course of molecular secretion from a single cell.

Animals↗
PubMed1998

Dipyridamole thallium-201 single-photon emission computed tomography for prediction of perioperative cardiac events in patients with arteriosclerosis obliterans undergoing vascular surgery.

The aim of the study was to determine whether or not dipyridamole thallium-201 single-photon emission computed tomography (201Tl-SPECT) has significant additive value for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) undergoing vascular surgery. Routine preoperative 201Tl-SPECT was performed in 106 consecutive patients with ASO (age 68+/-8.9 years; 91 men and 15 women). The frequency of reversible defects in a clinical high-risk group (n=44) was significantly higher than in a low-risk group (n=62; 55% vs 24%, p<0.01). Perioperative cardiac events occurred in 9 patients, including 4 cardiac deaths, 1 non-fatal myocardial infarction, and 4 cases of unstable angina. Although clinical risk stratification was useful in predicting cardiac events (19% in the high-risk group vs 2% in the low-risk group, p<0.01), the positive predictive value was low. When considering a combination of 2 or more than 2 risk factors and a large reversible defect as a predictor, the positive predictive value and specificity increased from 19% to 47% and from 64% to 91%, respectively, whereas the sensitivity remained unchanged (89%). These results suggest that the addition of 201Tl-SPECT data to clinical risk-stratified patients with ASO allows better prediction of perioperative cardiac events.

Adult↗
PubMed1998

[Characteristics of work, life and health analyzed in a survey of a hundred thousand employees of small companies and self-employed persons].

A study of business performance, life and health in small businesses by means of checklist consisting of 22 items and 66 subitems was done by All Commercial Union Mutual Aids Association from September through November, 1995. We analyzed 8 items related to "health." One representative person in each enterprise answered the questionnaire anonymously. The total number of responders was 97,527. Women comprized 18% of those study. 55% of responders were working in companies with only one or two employees. Compared to the government statistics, this study population was comparable to other industrial divisions with the exception of the engineering and construction industry which was three times as large and the wholesale and retail industry which was one-fourth the size. Workers with longer working hours a day reported lesser amounts of sleep. Those workers complained of uneasiness about their health and tended to work on holidays. They also carried their exhaustion over to the next day and did not have regular health examinations. The larger the decrease in sales compared with the previous year, the more the workers showed anxiety about their health and went to the hospital regularly. There was a strong correlation between the percentage of workers who answered "yes" for long working hours and "yes" percentage for a large decrease in sales. An often heard response was, "A doctor tells you to take a rest, but it's impossible to do so because of the job requirements." Among those who responded, there was a large group who were presently hospitalized.

Adult↗