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Biomedical subjects

T Yoshitake

Publications and source records attributed to T Yoshitake.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Reoperation in patients with thymoma].

For past seven years, reoperations were carried out for six patients with thymoma and myasthenia gravis (MG). Of six patients, five patients were suspected recurrent thymoma and remaining one patient was diagnosed as the residual thymus after thymothymectomy or thymomectomy. Myasthenia gravis has been progressing in five patients after initial operation except for one patient. Two cases of pleural dissemination tumors, one case of local recurrent thymoma and one case of the residual thymus were confirmed by surgery, remaining two patients had no recurrent tumor. As surgical procedure, median sternotomy using for reoperation has a great surgical risk, because left brachiocephalic vein closely adhered to the sternum is apt to be injured. Clinical symptoms of MG were improved in all the patients after reoperation regardless of recurrent tumor.

Adult↗
PubMed1993

[Coronary artery bypass surgery in patients with poor left ventricular function].

As the indications for coronary artery bypass grafting (CABG) among patients with poor left ventricular function remain incompletely defined, We undertook the study to assess the results of CABG surgery for a group of such patients. We retrospectively reviewed the clinical features and outcome for 7 patients with poor left ventricular function defined as an ejection fraction below 0.3 who underwent CABG. The mean age of the patients was 63 years (range, 38 to 78 years), and 4 were 70 years of age or older. All patients had history of previous myocardial infarction, and all had left main trunk stenosis or left main equivalent stenosis. The patients underwent CABG with three to six distal anastomoses (mean, 4.3/patient), the internal thoracic artery could be used in all patients, for one or two distal anastomoses (mean, 1.6/patient). Combined coronary endarterectomy was performed in 2 patients. With the exception of one 78-year-old patient with renal failure who died during the early postoperative period, all patients showed marked postoperative improvement in cardiac function. Cardiac catheterization and exercise stress test studies revealed significant improvement in left ventricular function and exercise tolerance in these six patients. These results suggest that excellent results can be obtained with CABG surgery in patients with poor left ventricular function when the viability of the myocardium in the bypassed area has been confirmed.

Adult↗
PubMed1992

High-performance liquid chromatographic determination of 3 alpha,5 beta-tetrahydroaldosterone in human urine with chemiluminescence detection.

A sensitive method for the determination of 3 alpha,5 beta-tetrahydroaldosterone (THALD) in human urine is described. The method uses high-performance liquid chromatography with chemiluminescence detection. Urinary THALD, released by enzyme hydrolysis, is isolated and concentrated using a Sephadex G-25M column and Bond-Elut C1 cartridges, and then oxidized by copper(II) acetate to form the corresponding glyoxal derivative. The glyoxal derivative is converted into the chemiluminescent quinoxaline by reaction with 4,5-diaminophthalhydrazide. The chemiluminescent quinoxaline is separated within 50 min on a reversed-phase column (TSKgel ODS-120T) with isocratic elution, followed by chemiluminescence detection; the chemiluminescence is produced by the reaction of the quinoxaline with hydrogen peroxide in the presence of potassium hexacyanoferrate(III) in alkaline solution. The detection limit for THALD is 0.6 pmol (220 pg) ml-1 in urine [1.5 fmol (0.53 pg) per 20 microliters injection] at a signal-to-noise ratio of 3. This method permits the sensitive and precise determination of THALD in human urine (50 microliters) from normal subjects and a patient with primary aldosteronism.

Aldosterone↗
PubMed1991

[Osteosarcoma developing after radiation and chemotherapy for primary mediastinal seminoma].

This report presented an osteosarcoma arising from the same field after radiation and chemotherapy without surgery for primary mediastinal seminoma. A 45-year-old man had received from June 1979 to August 1981 irradiation and chemotherapy for the anterior-mediastinal seminoma. Since then he was been without evidence of disease for five years. In March 1987, he had suffered from an advanced tumor extending from the neck and the mediastinum to the right anterior chest wall. Further irradiation combined with thermotherapy were performed but without improvement. He was thereafter seen and admitted July 23 1987 to our hospital with complaint of back pain. Needle biopsy specimen revealed chondrosarcoma. Despite chemotherapy with CDDP, he died four months later after admission. Pathological finding of his autopsy revealed a widely invading osteosarcoma extending to extra- and intrathorax and the neck without evidence of germ cell component. To explain the pathogenesis of the secondarily developing osteosarcoma, two hypotheses are offered; 1. Malignancy of mesenchymal component in germ cell tumor. 2. Radiation-induced osteosarcoma. The latter hypothesis appears to be the most probable pathogenesis from his autopsy. These findings suggest that a long survival patient with malignant germ cell tumor after therapy should be never considered as being free from a potential risk of secondarily developing malignancy.

Combined Modality Therapy↗
PubMed1990

Oxidation of nucleosides and nucleotides by peroxosulfate ions.

Treatment of 5-methylpyrimidine nucleosides and nucleotides with sodium peroxodisulfate in sodium phosphate buffer solution at pH 7.0 at 75 degrees C resulted in the selective oxidation of the methyl group. On the other hand, oxidation of thymidine by potassium peroxomonosulfate gave thymidine glycols.

Buffers↗
PubMed1990

[Primary mediastinal germ cell tumors].

The most frequent site of extragonadal germ cell tumors is the mediastinum. The majority (80%) of mediastinal germ cell tumors are benign mature teratomas, which can be easily removed. Malignant germ cell tumors account for approximately 20% of all cases and are clinically classified into seminoma and non-seminomatous germ cell tumors. Seminomas are radiosensitive and have relatively a good prognosis. Patients with non-seminomatous germ cell tumors had a very poor prognosis, however, the introduction of cis-platinum based chemotherapy has improved the prognosis of patients with these tumors. Three hundred twenty nine cases of malignant mediastinal germ cell tumors have been described in the literature and reports up to 1988 in Japan. The types and cases are following: [table: see text] Multi-drug chemotherapy with cis-platinum has improved the prognosis of patients with embryonal carcinoma and yolk sac tumors, although patients with choriocarcinoma have yet a poor response to the combination chemotherapy. Five year survivors have consisted of 19 patients with seminomas and five patients with non-seminomatous germ cell tumors. Most long survival patients have undergone surgical resection of tumors. The results suggested that the improvement for prognosis requires earlier prognosis and complete surgical removal of tumors associated with chemotherapy combining further effective regimens.

Adolescent↗
PubMed1989

Determination of 21-hydroxycorticosteroids in human urine by high-performance liquid chromatography with fluorescence detection.

A simple and sensitive high-performance liquid chromatographic method with fluorescence detection for the determination of nineteen 21-hydroxycorticosteroids is described. The corticosteroids are oxidized by cupric acetate to form the corresponding glyoxal derivatives. The derivatives are converted into fluorescent quinoxalines by reaction with 1,2-diamino-4,5-methylenedioxybenzene, a fluorogenic reagent for alpha-dicarbonyl compounds. The quinoxalines are separated within 70 min on a reversed-phase column (TSK gel ODS-120T) by stepwise elution with mixtures of methanol, acetonitrile, and 1.0 M ammonium acetate. The detection limits are 0.14-29.4 pmol at a signal-to-noise ratio of 3 in a 50-microliter injection volume. This sensitivity permits precise determination of hydrocortisone, cortisone, corticosterone, and their tetrahydro derivatives in 500 microliters of normal human urine.

Chromatography, High Pressure Liquid↗
PubMed1989

[Roentogenologic pathologic evaluation of allograft rejection in heart-lung transplantation--an experimental study in Japanese monkey].

Experimental heart-lung transplantation was carried out in Japanese Monkey (Macaca fuscata). Twelve monkeys survived two to thirty-three days. Pathologic examination of the lung was performed at the time of open lung biopsy and autopsy. Postoperative chest roentogenogram was also studied in seven monkeys. In the early postoperative period, central cloudiness and enhancement of the interstitial change were observed, which started from the second or third postoperative day and reached their peak between the fifth and eighth postoperative day. Pathological study revealed no obvious monocyte infiltration in the lung of this stage. Two types of pulmonary rejection were observed, one is alveolar and vascular rejection. The other is vascular type of rejection, which started as early as in the twelfth postoperative day in a case. In the former, consolidation of the lung was noticed and useful in the diagnosis, but in the latter, no distinct change was observed in plain chest roentogenogram.

Animals↗
PubMed1989

[Treatment of primary mediastinal germ cell tumors].

Primary mediastinal germ cell tumors are clinically classified into mature (benign) teratomas and malignant germ cell tumors. Mature teratomas should be surgically excised after diagnosis, because unnecessary delay may result in the rupture of tumors or in malignant degeneration. The prognosis after surgical removal of tumor is good and there is no recurrence of tumor after complete excision. Malignant germ cell tumors are therapeutically classified into seminomatous and nonseminomatous germ cell tumors. Nonseminomatous germ cell tumors comprise immature teratoma, teratocarcinoma (malignant teratoma), embryonal carcinoma, yolk sac (endodermal sinus) tumor and choriocarcinoma. Treatments for patients with them require an multidisciplinary therapeutic approach with radiotherapy or chemotherapy combined with surgical intervention. The prognosis of patients with these tumors are poor, however seminomatous germ cell tumors have a better prognosis than that of nonseminomatous tumors, because they are responsive to radiotherapy or chemotherapy and long survivals over five years after treatment are not rare among them. An aggressive cisplatin-based combination chemotherapy is performed for patients with nonseminomatous tumors who have mostly the elevated serum levels of AFP or beta-HCG as tumor marker. The serum levels of tumor markers reflect precisely the biological behavior of nonseminomatous tumors. Patients with the normalised serum levels of tumor markers after an medical intervention may have a good long prognosis following radical resection of tumors, although the sustained high serum levels of tumor markers after treatment indicate a poor prognosis. Long survivals over five years after therapy are extremely rare among them.

Combined Modality Therapy↗
PubMed1988

[Indications for thoracotomy in pulmonary metastatic sarcoma and its prognosis].

Between 1960 and 1987, 46 patients underwent thoracotomy for pulmonary metastatic sarcoma. The histologic classification of the sarcoma was osteosarcoma in 33 patients, other malignant bone tumors in 6 and soft tissue sarcoma in 7. The cumulative five-year survival rate of the 33 patients with osteosarcoma was 23%. Ten patients survived more than 3 years and 8 of them are still alive without pulmonary metastasis. Prognosis was significantly better with intensive multidrug chemotherapy. In this series, prognosis was not significantly related to the interval from initial onset to initial treatment, that from initial treatment to pulmonary metastasis and that from pulmonary metastasis to initial thoracotomy. The five-year survival rate of the 6 patients with other malignant bone tumors was 35%, and that of the 7 patients with soft tissue sarcoma 26%. Good indications for thoracotomy in pulmonary metastatic osteosarcoma are: (1) the primary sarcoma is resected, (2) the interval from initial treatment to pulmonary metastases is more than 6 months, (3) the number of pulmonary metastases is less than 4 or 5 nodules, and (4) the number and diameter of pulmonary metastases is controlled with chemotherapy within 2 or 3 months after occurrence of metastasis.

Adolescent↗