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Biomedical subjects

K Minami

Publications and source records attributed to K Minami.

At least 181 records · Page 10Linked to original sources
PubMed1997

Results of surgery for bronchogenic carcinoma located in the aortic window.

Because of its critical location, lung cancer located in the aortic window can cause complications affecting the pulmonary artery trunk, aortic arch and esophagus. The results of surgical treatment are poor; however, there are few long-term survivors. In an attempt to define the indications for extended surgery, we evaluated eleven patients with non-small cell lung cancer. The tumors were classified according to their clinical extent of invasion as Type A (invading the anterior mediastinum including the central part of the pulmonary artery), Type B (invading upwardly to the mediastinum through the aortic window) or Type C (invading the posterior mediastinum including the thoracic aorta or esophagus). In the five patients with type A invasion, no metastases to the upper mediastinal lymph nodes other than the subaortic lymph nodes were found. The three patients with type B invasion had many metastases to the upper mediastinal lymph nodes. There were no metastases in the upper mediastinum in any of these patients with type C invasion, but metastases were found in a lower mediastinal lymph node #9, and a carinal lymph node. Each group clearly demonstrated a different site of mediastinal lymph nodes metastasis. The long term result was good in Type A invasion, in contrast to Type B or C invasion. Our classification may be useful for planning one's surgical approach to advanced lung cancer of the aortic window.

Adult↗
PubMed1997

Ischemic cardiomyopathy--revascularization vs. transplantation.

Advanced coronary artery disease (CAD) and ischemic cardiomyopathy with elevated pulmonary artery pressures are criteria of a severe illness. In selected cases surgical revascularization has proved beneficial in terms of survival, reduction of morbidity and lowering the frequency of angina pectoris [6] in numerous studies over the past 25 years. But most of the earlier publications concentrated on patients with angina pectoris (AP) as a dominant symptom. Patients without AP but with predominant signs of congestive heart failure were largely excluded. This has changed recently [1-3,7,8,10,12,16,18] with the advent of the concept of hibernating myocardium. This term is defined as the presence of persistent myocardial and left ventricular dysfunction at rest due to reduced regional coronary blood flow that can be partially or completely restored to normal by myocardial revascularization [5,19]. Salvage of viable myocardium by successful revascularization improves left ventricular dysfunction. Diagnosis of hibernating myocardium is crucial because it does not leave the patient with chronic heart failure a candidate only for cardiac transplantation. Instead, these patients' left ventricular dysfunction is potentially reversible following revascularization by coronary bypass surgery. Furthermore we face a critical shortage of donor organs and extending waiting lists for possible transplant candidates. Following the start of the heart transplantation (HTX) program at our institution more than 690 operations were performed until September 1995. We screened more than 1600 patients for their eligibility as cardiac transplant recipients or for other forms of treatment. In this group of patients it has always been our policy to revascularize rather than transplant whenever possible.

Adult↗
PubMed1997

Heart transplantation for end-stage heart failure caused by iron overload.

Few reports exist concerning heart transplantation in recipients with end-stage myocardiopathy-associated heart failure caused by iron overload occurring with beta-thalassaemia, Diamond-Blackfan syndrome or haemochromatosis. Seven potential transplant candidates (six male, one female, mean age 26 years) with such heart failure, following desferrioxamine application subcutaneously over a number of years, and intravenously during their hospitalization before transplantation, were retrospectively analysed. Five were New York Heart Association (NYHA) class IV, three experienced one or more resuscitations immediately before transplantation could be performed. Continuous, high-volume, veno-venous haemofiltration was necessary in two patients. One of these two candidates additionally had to be bridged, first with a right ventricular, then with a biventricular assist device. Five of the seven patients survived, two with haemochromatosis, one with beta-thalassaemia major and one with Diamond-Blackfan syndrome following transplantation. One non-transplanted candidate with beta-thalassaemia major has been recompensated for 5 years. Survival was 14-74 months. Our results demonstrate the feasibility and indication of transplantation in patients with such heart failure and the satisfying outcome of immunosuppression is described.

Adolescent↗
PubMed1997

Long-term mechanical circulatory support.

Against the background of an increasing number of patients waiting for heart transplantation but a stagnating number of transplant procedures, long-term mechanical circulatory support is gaining major importance. We investigated the outcome of 20 patients (15 men, and 5 women, aged between 15 and 66 years) each supported for more than 100 days between September 1987 and August 1996. The indications for implantation were bridging in 17 patients, myocarditis in 2 patients, and postcardiotomy cardiogenic shock in one patient. 12 patients received the Novacor IVAD, 4 patients the Thoratec system, 3 patients the HeartMate device and one patient both Novacor and Thoratec. Mean duration of support was 178.1 days, 15 patients were transplanted, 14 of them could be discharged, 2 patients died, 4 patients are still waiting. The most frequent complication was device-related infection in 11 patients. The results have shown that all three systems are safe and reliable devices for supporting patients for more than 100 days.

Adolescent↗
PubMed1997

Inhibitory effect of the intravenous anesthetic, ketamine, on rat mesangial cell proliferation.

We studied the effects of ketamine and propofol on rat cultured mesangial cell (MC) proliferation. The 72-h exposure to ketamine (1-100 microM) inhibited [3H]thymidine incorporation into the MC in a concentration-dependent manner. Propofol, however, was not effective at inhibition of MC proliferation at doses from 1 to 100 microM. Ketamine also decreased the cell number at clinically relevant concentrations and increased adenosine 3',5'-cyclic monophosphate (cAMP) levels in MC. We also studied the effects of ketamine on cytokine-induced [3H]thymidine incorporation into the cells. Ketamine decreased the tumor necrosis factor-alpha (TNF-alpha)-, interleukin 1 (IL-1)-, and interleukin 6 (IL-6)-induced [3H]thymidine incorporation into the cells. It also decreased angiotensin II (Ag II)-induced [3H]thymidine incorporation. These results suggest that ketamine has inhibitory effects on MC proliferation, but that propofol does not. Because ketamine inhibits TNF-alpha-, IL-1-, and IL-6-induced MC proliferation, it may be useful in suppressing the cell growth clinically.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1997

Effects of pimobendan and its active metabolite, UD-CG 212 Cl, on Ca2+-activated K+ channels in vascular smooth-muscle cells.

The aim of this study was to clarify the mechanisms of activation of Ca2+-dependent K+ (K(Ca)) channels by pimobendan, a new cardiotonic and vasodilator agent with phosphodiesterase inhibition properties, and its main metabolite, UD-CG 212 Cl, in vascular smooth-muscle cells from porcine coronary arteries. Both pimobendan and UD-CG 212 Cl induced relaxation of porcine coronary artery strips. However, in the presence of 100 microM Rp-cAMPS (Rp diastereomer of adenosine cyclic 3',5'-phosphorothioate), a membrane-permeable antagonist of cAMP, the effects of pimobendan decreased significantly. Application of 1 microM pimobendan activated K(Ca) channels in cell-attached patches, and this increase in activity was suppressed by 100 nM H-89 (N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide), a cAMP-dependent protein-kinase inhibitor. Pimobendan was ineffective in altering the activity of K(Ca) channels in inside-out patches. In contrast, UD-CG 212 Cl, at a concentration of 1 microM, activated K(Ca) channels not only in cell-attached patches but also in inside-out patches. Application of 100 nM H-89 also inhibited UD-CG 212 Cl-induced K(Ca) channels activity but to a lesser degree than that induced by pimobendan in cell-attached patches. In conclusion, there are two mechanisms of activation of K(Ca) channels by pimobendan and UD-CG 212 Cl. Activation by pimobendan occurs primary through the cAMP pathway, whereas UD-CG 212 Cl activates K(Ca) channels directly as well as through the cyclic AMP pathway.

Animals↗
PubMed1997

Tuberculosis in heart transplant recipients.

STUDY OBJECTIVES: To clarify the prevalence and factors associated with tuberculosis, as well as patient survival in heart transplant recipients. DESIGN: A retrospective review of case records of all heart transplant recipients from March 1989 to February 1996 during a 7-year period. SETTING AND PATIENTS: During the period reviewed, 727 orthotopic heart transplantations were performed in 716 patients at the Heart Center Northrhine-Westphalia, Germany. RESULTS: Tuberculosis was proved in seven (1%) patients (four men/three women; age, 33 to 71 years; two miliary lesions, three pulmonary lesions, and two urogenital lesions). None of them had primary history of tuberculosis. Tuberculin skin tests were not performed before transplantation because there were no lesions indicating primary infection of turberculosis. The immunosuppressive regimen was based on double-drug (cyclosporine + azathioprine) therapy. Immunosuppression had been intensified by methylprednisolone pulses at least three times in those seven patients, and prednisone had been used orally in six of seven patients. Tuberculosis developed from 2.5 to 41 months after transplantation. Tuberculosis was found by routine examinations in four of seven patients. Diagnoses were made with both direct microscopy and cultures in six patients, and by histologic study in one. Treatment consisted of isoniazid, rifampicin, ethambutol, and pyrazinamide. Two patients with miliary lesions were treated with four drugs, and the others were treated with three drugs. Isoniazid was used in all patients. Rifampicin, which decreases cyclosporine serum levels, was not used from the beginning in one patient and treatment with it was stopped halfway in another patient because low cyclosporine level had induced rejection. Six of the seven patients are doing well while receiving antituberculous therapy. One patient died with miliary tuberculosis as a cause of death. CONCLUSIONS: The prevalence of tuberculosis in heart transplant recipients was higher than that in the general population. We recommend that a high degree of clinical suspicion is maintained for tuberculosis in heart transplant recipients with meticulous follow-up, and that the treatment of tuberculosis has to be with meticulous care, especially during the use of rifampicin.

Adult↗
PubMed1997

[Bronchogenic carcinoma located in the aortic window].

In the patients with invasion to the aortic window, we performed operation via median sternotomy combined with anteroaxillar thoracotomy. In such patients with T4 invasion, conventional pneumonectomy could not be performed because of the extensive invasion near the main pulmonary artery trunk. In these patients in this study, complete resection of the involved pulmonary artery could be performed using a vascular clamp without CP bypass. Operative technique was as follows: first, the pericardium was opened and taping of the aorta was applied. When the uninvolved part of the intrapericardial pulmonary artery was long enough to cut, we could use a stapling device, but the stapling device could not be used in many cases because the length of the uninvolved segment was too short to cut the left pulmonary artery. In order to carry out complete resection, it was necessary to clamp the central part of the main pulmonary artery diagonally from the left lower side to the right upper side. The pulmonary arterial stump was closed with continuous 4-0 monofilament mattress and over and over suture. We recommend an aggressive surgical approach for the tumor with invasion to the aortic window, because the prognosis is dismal in nonresected locally advanced lung cancer.

Aorta, Thoracic↗
PubMed1997

[MR dynamic subtraction angiography (MRDSA)].

We have developed magnetic resonance dynamic subtraction angiography (MRDSA), which depicts the long segments of arteries from the upper abdomen to the lower leg by using a small dose of Gd-DTPA. The lower half of the body was divided into three imaging regions, abdomen, thigh and lower leg, in the order of scanning. The contrast-enhanced three-dimensional breath-hold fast field echo technique with half Fourier acquisition was performed in 3 normal volunteers and 12 patients with vascular diseases (4: abdominal aortic aneurysm, 8: atherosclerotic occlusive disease). The images were reconstructed into composite images by using maximum-intensity-projection postprocessing after the subtraction of precontrast images. A bolus intravenous injection of a small dose of Gd-DTPA (0.02-0.05 mmol/kg) was given, followed by the five sets of scans. The acquisition time of each set was 8 to 16 seconds, and the total dose used in MRDSA was 0.1 to 0.15 mmol/kg. The image quality of MRDSA was satisfactory in 3 normal volunteers and 12 patients with vascular diseases. MRDSA demonstrated aortic aneurysm and atherosclerotic obstruction as clearly as conventional angiography. MRDSA can replace conventional angiography.

Angiography, Digital Subtraction↗
PubMed1997

Inhibition of 5-hydroxytryptamine type 2A receptor-induced currents by n-alcohols and anesthetics.

5-Hydroxytryptamine type 2A receptors (5-HT2A) are G protein-coupled receptors that increase intracellular Ca2+ concentrations via activation of phospholipase C-beta and elevation of myo-inositol-1,4,5-triphosphate levels. In the central nervous system, these receptors are involved in regulating sleep and alertness. We now report that ethanol inhibited (IC50 = 41 mM) 5-HT2A receptor-induced Ca2+-dependent Cl- currents in Xenopus laevis oocytes. Pharmacologically relevant concentrations of other n-alcohols (propanol to octanol) also inhibited 5-HT responses; however, longer-chain alcohols (decanol, undecanol and dodecanol) had little or no effect. The protein kinase C inhibitor GF109203X and the nonspecific protein kinase inhibitor staurosporine abolished the inhibitory effects of ethanol and octanol on 5-HT2A receptors. GF109203X enhanced 5-HT2A receptor function when administered alone. In addition, the volatile anesthetics halothane and 1-chloro-1,2,2-trifluorocyclobutane decreased 5-HT2A responses in a concentration-dependent manner. The inhibitory effects of the volatile anesthetics were also attenuated in oocytes treated with GF109203X. The intravenous anesthetics propofol, ketamine, pentobarbital and etomidate did not affect 5-HT2A receptor function. The modulation of 5-HT2A receptor-dependent current was also investigated using two novel halogenated compounds that do not produce anesthesia. The nonanesthetic compound 2,3-chloro-octafluorobutane had no effects on 5-HT-induced currents; however, the nonanesthetic compound 1,2-dichlorohexafluorocyclobutane had an inhibitory effect at lower concentrations than the predicted anesthetic concentration. Thus, 5-HT2A receptors are inhibited by alcohols and volatile anesthetics, and these actions are dependent on protein kinase C.

Anesthetics↗
PubMed1997

Pulsatile and nonpulsatile extracorporeal circulation using Capiox E terumo oxygenator: a comparison study with Ultrox and Maxima membrane oxygenators.

An open randomised, prospective study was undertaken on 90 patients who underwent routine myocardial revascularization. The aim of the study was to demonstrate that the Capiox E polypropylene fiber membrane oxygenator with a conventional single pulsatile/nonpulsatile blood pump for cardiopulmonary bypass (CPB) was comparable in performance to that of the Maxima and the Ultrox membrane oxygenators using a double pump system. The patients were divided into six groups according to perfusion mode and oxygenator type. Laboratory parameters, fluid balance and oxygenation was examined at set times before during and after cardiopulmonary bypass. Net fluid input was lower in the Capiox E groups regardless of perfusion mode: 2932 +/- 562 ml (Capiox E), compared to 3646 +/- 531 ml (Ultrox) and 3593 +/- 582 ml (Maxima). Net fluid balance 1288 +/- 534 ml was lowest in the Capiox/NP group, compared to 1604 +/- 460 ml (Ultrox/NP) and 1881 +/- 594 ml (Maxima/NP), (p < 0.05). The higher net fluid balance in the Capiox E/PP group 1649 +/- 580 ml compared to 1592 +/- 583 ml (Ultrox E/PP) and 1494 +/- 542 ml (Maxima/PP) was attributed to a technicality whereby the recommended priming volume of the Capiox E oxygenator was exceeded for safety reasons. The values of plasma free Hb were slightly higher in the PP than NP groups: Maxima/PP 80 mg/dl, /NP 50 mg/dl; Ultrox/PP 62 mg/dl, /NP 48 mg/dl; Capiox E/PP 55 mg/dl, /NP 48 mg/dl. The FiO2 was higher in the Capiox E groups 0.77 (PP) and 0.88 (NP) compared to Maxima/PP (0.66), /NP (0.65) and Ultrox/PP (0.64), /NP (0.63). Reciprocally, the venous saturation was higher in the Ultrox and Maxima groups compared to Capiox E at end of CPB. The study demonstrated that the CapioxE oxygenator with a single blood pump system can compare to the Maxima and Ultrox oxygenators with a double blood pump for CPB with regard to blood handling, oxygenation and fluid balance in routine cardiac surgery.

Blood Gas Analysis↗
PubMed1997

[A case of a premenopausal woman with advanced breast cancer treated with aromatization inhibition in combination with luteinizing hormone-releasing hormone agonist].

A 44-year-old premenopausal woman having local recurrence and pleural and bone metastases of breast cancer was treated with aromatization inhibition in combination with Luteinizing Hormone-releasing Hormone (LH-RH) agonist. The dominant site of metastasis was a painful local lesion invading the chest wall. A partial response by reducing the size of the local lesion was attained 3 months after initiation of treatment. This result suggested that treatment using aromatization inhibition in combination with LH-RH agonist would be effective in premenopausal breast cancer. To confirm the effectiveness of this treatment, comparative study between aromatization inhibition in combination with LH-RH agonist aromatization inhibition alone and anti-estrogen in combination with LH-RH agonist are needed.

Adult↗
PubMed1997

Surgical repair of pulmonary stenosis with intact ventricular septum in a 68-year-old woman.

Patients with mild pulmonary stenosis after infancy rarely have symptoms or develop increasing obstruction. We experienced a 68-year-old woman with severe pulmonary valvar and infundibular stenosis (peak to peak pressure gradient = 80 mmHg). She had been pointed out heart disease at the age of six. Endocarditis at the age of 17 might induce calcification of valve and affect the progression of pulmonary stenosis, and moreover, which might gradually develop severe subvalvar obstruction and poststenotic aneurysm of pulmonary trunk. She refused operative intervention because of mild clinical symptoms (NYHA class II), but we recommended surgical repair due to repeated transient ischemic attacks, which were suspected paradoxical embolism through persistent foramen ovale. She underwent pulmonary valvotomy and infundibular resection and is doing well.

Aged↗
PubMed1997

[Usefulness of percutaneous microwave tissue coagulation therapy for solitary liver cancer].

The possible use of percutaneous transhepatic microwave tissue coagulation therapy (PMCT) using ultra-sonography under local anesthesia for solitary liver cancer was studied. The subjects were 8 patients having primary or metastatic liver cancer with solitary liver tumor less than 4 cm in size, consisting of 2 hepatocellular carcinomas, and 6 metastatic carcinomas. PMCT was performed continuously 3 times at the output of 30 watts for 30 seconds at a time. Tumors less than 3 cm in size were completely coagulated by irradiation from 2 to 5 times judged by enhanced CT. No recurrence of tumor was recognized in the coagulation area. But in some cases, multiple metastases were found at another site in the liver by 3 months after PMCT. Thus, the results suggest that PMCT is a useful therapy for small liver tumor as a local control.

Aged↗