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Biomedical subjects

T Iwa

Publications and source records attributed to T Iwa.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Coronary bypass surgery for solitary stenosis of the left main coronary artery].

Ten patients with solitary stenosis of the left main coronary artery underwent coronary artery bypass grafting. All patients suffered from unstable angina and were in NYHA class III or IV. Two of them required intravenous infusion of nitroglycerin preoperatively. The degree of stenosis of the left main coronary artery was 75% in 3 patients, 90% in 5, 95% in one and total obstruction in the other one. Five patients received saphenous vein grafts to the LAD and circumflex artery and the other 5 patients received IMA grafts to the LAD and saphenous vein grafts to the circumflex arteries. In 2 patients with 75% stenosis of the left main coronary artery we found narrow internal mammary artery grafts, the so called "string sign", on postoperative angiography. Although several causes of string sign were proposed previously, we supposed that the main cause of the "string sign" was the competition for flow between the IMA graft and the native coronary artery or grafted coronary artery. Postoperatively, all patients showed improvements in cardiac function and were in NYHA class I. No evidence of ischemic findings was found in postoperative exercise stress tests.

Adult↗
PubMed1991

[A case of leiomyoma of the intermediate bronchus].

Leiomyoma of the trachea and bronchus is a rare tumor. Only 45 cases have been reported in the Japanese literature. We report here a case of leiomyoma of the intermediate bronchus which was successfully operated on. A 45-year-old man suffered from a repeated episode of pneumonia in the right lower lobe. Bronchoscopy revealed a polypoid mass on the intermediate bronchus. The diagnosis of leiomyoma was made by bronchoscopic biopsy. Sleeve resection of the intermediate bronchus including the tumor and end-to-end anastomosis was performed. His postoperative course was uneventful and bronchoscopic findings showed clear healing of the anastomotic site. The resected specimen contained a tumor with smooth surface having protrusion into the bronchial lumen with 6 x 5 x 4 mm in size. The final pathological diagnosis was leiomyoma of the intermediate bronchus with no evidence of malignancy.

Anastomosis, Surgical↗
PubMed1991

A new anticancer drug delivery system for the management of carcinomatous peritonitis.

To develop a new drug delivery system for the treatment of carcinomatous peritonitis, we constructed 5-fluorouracil poly L-microcapsules (5Fu-mc) by the organic phase separation technique and examined their drug-releasing capacities and anticancer effects. The microcapsules consisted of in vitro dissolvable polymolecular poly L-lactic acid and 5-fluorouracil (5Fu). The 5Fu-mc was about 200 microns in diameter and had a 5Fu content of about 40% (weight/weight). 5Fu-release time from the microcapsules was about 50 hours in vitro and about 48 hours in vivo. After the release of the 5Fu, the poly L-lactic acid was metabolized very slowly in the peritoneal cavity. The 5Fu-mc caused fewer side effects than the equivalent dose of a 5Fu solution. In addition, macroscopic and microscopic examinations of various abdominal organs revealed no toxic effects from the microcapsules. After administration of 5Fu-mc into the abdominal cavity of rats with AH-130 carcinomatous peritonitis, the 5Fu concentration remained at a high level for an extended period in the ascites but fell rapidly to low levels in the plasma. In conclusion, the present studies indicated that the 5Fu-mc were much more effective in prolonging the life of tumor-bearing hosts while producing less systemic side effects than a 5Fu solution.

Alanine Transaminase↗
PubMed1990

Immune reactivity in bronchogenic carcinoma and its relation to 5-year survival rate.

We performed a prospective study on the correlation of various parameters of the immune response with the 5-year survival rate in patients with bronchogenic carcinoma. Parameters were initially examined before starting treatment. Delayed hypersensitivity skin tests, lymphoblastogenesis, natural killer (NK) cell activity, and interleukin-2 (IL-2) production were employed to assess immune competence. Each reaction was classified into four or five grades in accordance with intensity; the 5-year survival rate of the patients showing each grade of the immune response was calculated. A correlation between response before treatment and the survival rate was most clearly noted for lymphoblastogenesis. The skin tests and the NK cell activity showed poorer correlations, and no exact correlation was noted between the IL-2 production and the immune response.

Carcinoma, Bronchogenic↗
PubMed1990

Left ventriculotomy of the heart: tissue repair and localization of collagen types I, II, III, IV, V, VI and fibronectin.

The reparative process following left ventriculotomy was investigated immunohistochemically using anti-type I, II, III, IV, V and VI collagen antibodies, and anti-fibronectin antibody. Wound healing began with proliferation of young fibroblasts positive for type I, III and V collagens at the wound margin; vascular granulation tissue then grew into the injured myocardium followed by deposition of fibrous components immunoreactive with type I and III. At 30 days after operation when almost the entire thickness of the myocardium at the wound was replaced by fibrosing granulation tissue, a small cluster of adipocytes appeared around capillaries at the wound margin. The granulation tissue was gradually replaced by the adipose tissue with establishment of a fibrous union at the subendocardium by 90 days. In addition to type I and III collagens, type VI collagen was detected in a fine fibrillary pattern along thick collagen fibre bundles in the fibrous tissue and around the adipocytes. Fibronectin was distributed diffusely in the granulation tissue and gradually decreased with increase of the fibrous components. These results indicate that the ventriculotomy was finally repaired in the form of a fibrous scar, particularly in the endocardium. There was marked infiltration of adipose tissue in the damaged myocardium. Presumably type VI collagen, as well as type I and type III collagens, plays an important role in wound union.

Animals↗
PubMed1990

Changes in immunological parameters in lung cancer patients undergoing immunotherapy with streptococcal preparation OK-432.

We have studied the immunological status of patients treated with streptococcal preparation OK-432. Two KE of OK-432 was injected intramuscularly once every week for more than three years unless the patients died. The natural killer (NK) activity in those patients who underwent curative surgery for lung cancer and had no sign of recurrence was significantly increased (P less than 0.01) during the OK-432 treatment. However, the NK activity in the patients who had persistent disease (non-resected cases, incompletely resected cases or recurrent cases) was not significantly increased in comparison with that before the immunotherapy. Also, in the cases with no clinical symptoms of recurrence, both the lymphoblastogenetic reactions to the mitogens and the IL-2 production were significantly enhanced (P less than 0.01) during the administration of OK-432. Reactions in the SU-PS (polysaccharide taken from the cell-wall fraction of the Streptococcus pyogenes SU strain and containing 7.2% of protein) skin-test appeared to significantly correlate with the immunological status of the patients under OK-432 therapy, but the PHA and PPD skin reactions showed no definitive enhancement. The survival rate of the patients whose SU-PS skin tests were positive during the OK-432 immunotherapy was significantly higher (P less than 0.01) than that of the patients with negative reactions.

Humans↗
PubMed1990

Reappraisal of bronchial arterial infusion therapy for advanced lung cancer.

As preoperative adjuvant therapy for advanced lung cancer, bronchial arterial infusion (BAI) of a chemotherapeutic agent was administered to patients with stage IIIa and IIIb hilar lung cancer. The infusion modality was changed for each term, from a single drug infusion, to a two drug infusion and then a three drug infusion, and the combination of infused drugs was selected in accordance with cell types. A significant radiographic shrinkage was observed after BAI therapy by the single, two and three drug infusions, being noted as 40.7 per cent, 61.8 per cent and 83.9 per cent, respectively. The effect on squamous cell carcinoma was more prominent than on other cell types. Upon microscopic examination of the resected specimens, significant histo-pathological effects were observed in 57.7 per cent of the patients who received single or two drug infusions, while the rate increased to as high as 92.2 per cent in the patients who received the three drug infusion. The histological effects of BAI therapy were also most marked in squamous cell carcinoma. It is of special interest that 5 of the 10 patients who received the three drug infusion of Carboquone (CQ) + Mitomycin C (MMC) + Nimustine-HCL (ACNU) for squamous cell carcinoma, showed complete disappearance of viable cancer cells at the tumor site; something which was never observed after the single and two drug infusions. It was therefore concluded that BAI therapy for advanced lung cancer should be reappraised through the modification of infusion methods.

Adenocarcinoma↗
PubMed1990

Results in 104 patients undergoing bronchoplastic procedures for bronchial lesions.

Bronchoplastic procedures were used in 104 patients with various bronchial disorders. Ten had benign lesions and 94, malignant tumors. The principal operative procedures were sleeve lobectomy and sleeve pneumonectomy for bronchogenic carcinoma, but 11 limited bronchial resections were performed in patients with benign lesions, minute bronchogenic carcinomas, and low-grade malignant tumors. Of the 94 patients with malignant tumors, 79 underwent a bronchoplastic procedure without carinal resection (sleeve lobectomy in 75 and limited bronchial resection in 4), and there was one operative death (1.3%). The overall 5-year survival rate for the patients with bronchogenic carcinoma in this group was 45% and that for patients undergoing curative resection, 57% (survival of patients in stages I, II, and IIIA was 79%, 55%, and 30%, respectively). A bronchoplastic procedure with carinal resection was performed in 15 patients. Twelve in this group underwent sleeve pneumonectomy. There were two operative deaths, and 1 patient has survived for longer than 4 years. Two patients with low-grade malignant tumors underwent carinal resection without lung resection and are still alive. We believe that bronchoplasty is a safe and valuable procedure and that limited bronchial resection appears to be the procedure of choice for localized bronchial lesions.

Bronchi↗
PubMed1990

Thermally controlled laser irradiation of the myocardium with intraoperative ultrasound monitoring.

We used intraoperative ultrasonography (IOUS) to study the feasibility and safety of Nd:YAG laser irradiation of the myocardium in 26 canine left ventricular segments. During the laser irradiation process, the myocardial temperature was monitored and surface cooling was used. Afterward, intraoperative ultrasonographic scans, which enabled the evaluation of the irradiated lesions, were compared with cross sections made through the tissues. The total dose of laser energy ranged from 200 to 3,600 joules, and the estimated volume of irradiated lesions ranged from 76.8 to 2590 mm3. There were significant correlations between the laser discharge output (in joules [J]) and the irradiated lesion volume (P less than 0.001), and between the laser energy density (in J/mm2) and the depth of the lesions (P less than 0.01). Macroscopic examination of the cross sections of irradiated myocardium revealed that the lesions were well-demarcated, but not charred or perforated. Thus, we could obtain a satisfactorily large zone of laser photocoagulation without inducing tissue damage, if surface cooling was used and the myocardial temperature was monitored. IOUS was successful in visualizing and locating the irradiated lesions that were seen as hypoechoic, clearly outlined nodules. We submit that this study has established the technical feasibility and dose-response relationship of thermally controlled laser irradiation, and has demonstrated the usefulness of IOUS for the precise localization and monitoring of such laser treatment.

Animals↗
PubMed1990

Better predictors of successful His-bundle ablation analysis of first shocks.

We have reported here that a longer HV interval in association with a larger His amplitude yields a high rate of success when used to position the ablating catheter for His-bundle ablation. Additionally, we have shown that double discharge shocks are more effective than single discharge shocks, and that negative polarity is more effective than positive polarity. The use of bipolar or tripolar, and not quadripolar catheters, was also associated with a higher success rate. In our institution, using a bipolar catheter, we attempt to record an HV interval greater than 55 msec and a His amplitude greater than 0.35 mV. When both of these criteria are fulfilled, we use 3 to 4 joules per kg, and a single discharge shock. When one or the other of these criteria are not fulfilled, we use the double discharge shock method. Using these techniques, we have achieved successful His-bundle ablation with only one shock in all but one of the most recent 21 consecutive patients.

Bundle of His↗
PubMed1990

Functional character and augmentation of lymphocytes in regional lymph nodes of patients with lung cancer.

It appears that lymph node metastases are more frequent in lung cancer than in other cancers because of impaired defensive mechanisms in the regional lymph nodes. However, little is known about the immunologic function of regional lymph node lymphocytes (RLNL) in patients with lung cancer. We have studied the immunologic properties of RLNL in comparison with peripheral blood lymphocytes (PBL). We measured the natural killer (NK) cell activity of RLNL and PBL in patients with lung cancer and found that the NK activity was significantly more depressed in the RLNL than in the PBL. In contrast, interleukin-2 (IL-2) production was markedly higher in the RLNL than in the PBL. The cytotoxic effect of RLNL in nonmetastatic lymph nodes on target cells (such as K562 cells) or PC-3 and PC-10 cells (NK-resistant, human lung cancer of adenocarcinoma and epidermoid carcinoma, respectively) was significantly enhanced by in vitro incubation with recombinant IL-2 (rIL-2). Furthermore, we clarified that both rIL-2 and OK-432, which is a biologic response modifier and IL-2 inducer as well, augmented the cytotoxicity of RLNL and that these effector cells were lymphokine-activated killer (LAK) cells. The depletion of lymphocyte subsets by pretreatment with specific monoclonal antibody showed that the LAK activity in RLNL was mediated by CD3+ and CD8+ cells, whereas the lymphocyte subsets contributing the LAK activity in PBL were CD3+ and CD16+ cells. It was concluded that a majority of the effector cells in RLNL were LAK cells of the cytotoxic T cell population.

Adult↗
PubMed1990

Surgical management of life-threatening arrhythmias.

Map-guided direct surgery was performed in 408 patients with various tachyarrhythmias at our institution. Of 355 patients with WPW syndrome, 5 had experienced an episode of ventricular fibrillation (Vf), 180 had atrial fibrillation with a rapid ventricular response, and 76 had other heart diseases. These patients were regarded as being at risk for sudden death. The shortest R-R interval between pre-excitation (215 +/- 38 msec) was significantly shorter than the antegrade effective refractory period (270 +/- 35 msec) of accessory pathway (ACP) in 126 patients (p less than 0.001). The shortest R-R interval of the patients with Vf was 200 msec or less. The ACP was successfully interrupted in 334 patients (94%). Simultaneous operations were carried out for other types of heart disease in 58 patients. Surgery was performed in 43 patients with ventricular tachycardia (VT), 39 non-ischemic and 4 ischemic, who were unresponsive to conventional antiarrhythmic therapy. Three patients with non-ischemic VT required emergency operation. The principle of surgery for non-ischemic was excision plus cryocoagulation of right ventricle and incision plus cryocoagulation of left ventricle. Thirty non-ischemic patients (76.9%) were cured of VT, while 7 still take medication prophylactically (3 for sporadic premature beats, and 4 for VT). All 4 patients with ischemic VT were also treated successfully. In conclusion, our results demonstrate the therapeutic value of map-guided direct surgery for life-threatening arrhythmias.

Adolescent↗
PubMed1990

Mediastinal spread of metastatic lymph nodes in bronchogenic carcinoma. Mediastinal nodal metastases in lung cancer.

The location, frequency, and spread of metastases to the mediastinal lymph nodes were examined in 124 patients with histologically proven N2 disease who underwent pulmonary resection and total lymph node resection. There were one-level metastases in 47 percent of cases, two-level metastases in 29 percent, three-level in 12 percent, and 12 percent had four or more levels of metastases. Nodal metastases to the lower mediastinum from upper lobe cancer were frequently observed as were metastases of lower lobe cancer to the upper mediastinum. The frequency of the latter was higher than that of the former. About one third of squamous cell carcinoma and adenocarcinoma in the right upper lobe produced nodal metastases in the lower mediastinum. In addition, there were often skip metastases to the nonregional parts of the mediastinum without regional nodal involvement in the mediastinum. From the results of the present study, it appears that extensive mediastinal dissection should be recommended in surgery for lung cancer irrespective of the location of the primary tumor.

Carcinoma, Bronchogenic↗
PubMed1990

[Treatment of Wolff-Parkinson-White syndrome associated with asthma].

We performed division of accessory pathways in five asthma patients associated with Wolff-Parkinson-White (WPW) syndrome, for whom the administration of a beta-blocker for the tachycardia is contraindicated, and the administration of bronchodilators for the asthma attack may cause premature ventricular contractions. As a result, the tachycardic attacks disappeared postoperatively, both at rest and following administration of bronchodilators. Radical treatment of WPW syndrome by division the accessory pathway is considered to be necessary for the safe treatment of asthma.

Adrenergic beta-Antagonists↗
PubMed1990

[Surgical treatment of Wolff-Parkinson-White syndrome].

The paper presents the data on 365 operations to arrest the Wolff-Parkinson-White syndrome, which were performed in the period of 1973 to July 1989 in the Clinical Hospital, University of Kanazawa. The authors were the first to apply an endocardial access to remove Kent's bundle. They obtained the following results: later on 344 of 365 patients undergone surgery had no recurrent tachycardias. Incomplete abolition was observed in 21 patients, but relapses of tachycardias were absent. A total of 11 patients died within 1 to 32 days of postsurgery. The authors have noted that they achieved 100% positive results in the last series of 101 operations: there was no relapse of tachycardias, repeated operations, atrioventricular block and deaths. At present, the surgical technique for arresting the WPW syndrome has some advantage over drug therapy. The operation fully makes the patient recovered, while with conservative therapy he has to be on drugs during his life.

Adult↗
PubMed1990

[Surgical treatment of non-ischemic ventricular tachycardia].

The authors reviewed the results of 42 operations for non-ischemic ventricular tachycardias, tachycardia being arrested by laser ablation in 2 cases. Right and left ventricular tachycardias were seen in 26 and 14 patients, respectively. For diagnosis, preoperative electrophysiologic study, intraoperative epicardial mapping, and "delayed" potentials were used. In 38 of 40 patients who had undergone a direct operation, a positive result was obtained; in 31 patients, a complete disappearance without applying antiarrhythmics was observed. Four patients received drug therapy which proved to be ineffective before surgery. Two patients died after surgery due to recurrent tachycardia. Out of 38 survivals, 3 died of heart failure that was not caused by recurrent tachycardia.

Action Potentials↗
PubMed1990

[A study on pre-operative administration of 5'-DFUR in carcinomas of the gastric, breast, thyroid and colon].

Pre-operative chemotherapy for 7 days with 5'-DFUR (p.o.) were carried out in the patients with gastric, breast, thyroid and colon cancers. The concentration of 5-fluorouracil (5-FU) in tumor cells was higher than that in the normal tissue. In case of breast cancer, it was 10 times higher than normal tissue. The concentration of 5-FU at the metastatic lymph nodes in gastric cancer was considerably high. The pattern of DNA histogram changed when chemotherapy was applied, and we observed the G2 and M phase block.

Antineoplastic Agents↗