Search PubMed⌕ Search

Biomedical subjects

M Aoki

Publications and source records attributed to M Aoki.

At least 667 records · Page 37Linked to original sources
PubMed1989

[Histological observations of immunosuppressive effects of FK-506 in canine lung allotransplantation].

The Immunosuppressive effects of FK-506 were studied histologically in allotransplanted canine lungs. FK-506 was administered daily in a dose of 0.15 mg/kg after left lung allotransplantation. Nine dogs underwent open lung biopsy on the 7th postoperative day (p.o.d.). Mild mononuclear cell infiltrations around small vessels (MNC cuffings), which suggested an early phase of rejection, were observed in 2 dogs. Two dogs were sacrificed on the 14th and 2 on the 21st p.o.d. MNC cuffings were observed in the lung of one dog and in the bronchial submucosa of 2 dogs. Six dogs were sacrificed on the 28th p.o.d. MNC cuffings were observed in the lungs of 3 dogs and in the bronchial submucosa of 5 dogs. The MNC cuffings were of nearly the same extent in the lung and in the bronchial submucosa of most of the dogs. Alveolar structures were well in all the dogs and the bronchial epithelium in all except 2 of the dogs sacrificed on the 28th p.o.d. preserved. Arterial blood gas was examined before and 20 min. after right hilar ligation in 3 dogs on the 28th p.o.d. The PaO2 (228 mmHg, 312 mmHg, 217 mmHg at FiO2: 0.5, tidal volume: 20 ml/kg, respiratory rate: 20/min) and PaCO2 after rt, hilar ligation indicated that the transplanted lung was functioning well in these dogs. The present study suggests that FK-506 could be a potent immunosuppressive agent in lung transplantation. As 4 of the 14 dogs used in this experiment died from severe diarrhea caused by FK-506, further studies are needed to determine the suitable dose and route of administration of FK-506.

Animals↗
PubMed1989

[A clinical study of six surgically treated patients with malignant tumors arising from chronic pleuritis and pyothorax].

During the clinical course of chronic pleuritis and pyothorax, we frequently have found abnormal clinical signs such as increased abnormal chest shadows, subjective symptoms, such as chest pain and bloody sputum, and the appearance of atypical cells in the pleural effusion. It is very difficult and important to diagnose differentially worsening of chronic inflammation and occurrence of malignant tumors. We have surgically treated six patients with malignant tumors arising from chronic pleuritis and pyothorax, who had the above abnormal signs. All of them were made, and their average age was fifty three years. Two patients exhibited increased abnormal chest shadows, 5 had subjective symptoms (5 with chest pain, 2 with bloody sputum and 2 with fever), and 1 had atypical cells in the pleural effusion. Two patients had suffered from chronic pleuritis, who both had received artificial pneumothorax therapy for pulmonary tuberculosis, and the other 4 patients had suffered from chronic pyothorax, with mean duration of thirty years. The pathological diagnoses were 2 cases each of malignant pleural mesothelioma, squamous cell carcinoma, and malignant fibrous histiocytoma. The two patients with squamous cell carcinoma had pleurocutaneous and bronchopleural fistula. The operative methods were tumor resections with pleuropneumonectomy performed in 2 patients and pneumonectomy in 1. Absolute non-curative operation was performed in 1 patient, and postoperative radiotherapy in 3 patients. All patients died of tumor recurrence, although five of them underwent reoperation, chemotherapy and radiotherapy. Their duration of survival ranged from 3 to 15 months with a mean of 9 months after appearance of malignant tumor signs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Quantification of myocardial infarct size by technetium-99m pyrophosphate single photon emission computed tomography].

Myocardial infarct size in 41 patients with the first attack of acute transmural myocardial infarction (MI) was assessed by technetium-99m pyrophosphate single photon emission computed tomography (99mTcPYP-SPECT). A ratio of the number of voxels of 99mTcPYP uptake into the infarct area to that into the thorax was calculated as a parameter of MI size. The ratio was positively correlated with both peak CPK activity (r = 0.53, p less than 0.005, n = 24) and extent score in 201TI-SPECT (r = 0.70, p less than 0.005, n = 14) significantly in patients with anterior MI but not in patients with inferior MI. There was also significant negative correlation between the ratio and the left ventricular ejection fraction (LVEF) measured by RI angiography in both acute (r = -0.67, p less than 0.005, n = 18) and chronic (r = -0.75, p less than 0.005, n = 25) phases in patients with anterior MI. Recovery in LVEF at chronic phase was noted in patients with small anterior MI but not with large anterior MI. 8 of 14 patients with inferior MI had right ventricular MI, that might have affected evaluation of MI size and resulted in no correlation between variables. It was suggested that 99mTcPYP-SPECT was a useful method to evaluate MI size and to predict prognosis of cardiac function in patients with anterior MI but not in patients with inferior MI.

Adult↗
PubMed1989

[Surgical treatment of small cell lung cancer].

Thirty-four small cell lung cancer (SCLC) patients underwent surgery in Kyoto University from 1976 to 1989. The mean age was 62 years males numbered 25 cases, and females 9. All cases were LD except 2 rib-metastasized patients. Seventeen patients were in PS 0, and 17 in PS 1. Twenty-eight patients were treated with chemotherapy. In the remaining 5 patients 2 were treated by only oral 5-FU derivatives, one died upon operation, one was unable to be treated because of advanced age, and the last one refused chemotherapy. Except for the one operational death, 33 cases were able to be evaluated. Out of 28 patients, 16 were treated only by post-operative chemotherapy. As for operational radicality, 21 out of 31 cases were operated radically (68%). The survival rate of these 33 patients reached 78% for 1 year, 37% for and 5 years, with MSI at 26 months. The neoadjuvant (+) group showed a better prognosis than the non-non-neoadjuvant group.

Adult↗
PubMed1989

[Thermal analgesia following intrathecal capsaicin administration in rats--detailed measurements of thermal analgesia over the lower body by a thermal probe].

This study was undertaken to examine the thermal pain thresholds over a wide area of the lower body surface following the intrathecal administration of capsaicin in rats. Thermal nociceptive thresholds measured under light halothane anesthesia were determined as skin twitch or escape response latencies to the heat stimulation (52.0 degrees C) by a thermal probe. Capsaicin (50 micrograms in 10 microliters) was injected through a chronically implanted catheter whose tip was near the lumbar enlargement of the spinal cord. The hot-plate test (52.0 degrees C) was also performed in all rats tested. Increase in thermal pain thresholds were consistently observed in the low back and abdominal region, while the hind paws did not always respond with prolonged skin twitch or escape latencies. Intensities of thermal analgesia at the sole of hind paws measured by hot-plate test correlated well with those by thermal probe test. In conclusion, intrathecal capsaicin definitely produced thermal analgesia, but its intensity was considerably variable in the hind paws. These results are in keeping with our previous finding that there was much variability in the effect of capsaicin assessed by the hot-plate test, indicating a possibility that capsaicin does not spread uniformly in the CSF because of its water insolubility or difficulty in penetrating to the large nerve roots innervating the hind paws.

Analgesics↗
PubMed1989

[Nd-YAG laser therapy in the field of pulmonary surgery].

Since 1980, we have treated 71 patients with malignant tumors and benign lesions by the Nd-YAG laser. The flexible fiberoptic bronchoscope with the local anesthesia was used for the treatments. Fifty-four cases were malignant tumors and 17 were benign lesions involving trachea and/or hilar bronchus. In malignant tumors, 41 cases were lung cancers, 24 of which were squamous cell carcinomas. Of 17 cases of benign lesions, 10 (58.5%) were introgenic stenoses. Palliative treatments were done for 36 cases of lung cancers, of which 23 died within 1 year after treatments. Four of 5 cases, which survived beyond 2 years, were adenoid cystic carcinomas. In 17 benign cases, 13 (76.5%) showed distinct improvements of symptoms and findings after treatments. Three patients died of massive bleedings. In these cases, severe stenoses were observed, which required treatments repeatedly. With the proper knowledge of the indications, limitations and complications, of YAG laser therapy it can be a beneficial mean for the management of benign lesions and malignant tumors in trachea and hilar bronchus.

Female↗
PubMed1989

[Technical problems on right lung transplantation].

This report describes the technique of the allo-transplantation of the right lung of an adult mongrel dog. Compare to the transplantation of the left lung, we found several pitfalls in the right lung transplantation. 1) The intraatrial groove of the recipient must be divided carefully just at the middle of the right and the left atrium in order to make a generous cuff for the left atrial anastomosis. 2) It is preferable to divide azygos vein to perform easy anastomosis of right pulmonary artery and right bronchus. 3) Care must be taken to make left atrial cuff in donor lung since we did not divide intraatrial groove in the donor animal. It was necessary to make the left atrial cuff with a part of the right atrium attached.

Anastomosis, Surgical↗
PubMed1989

Localization of megakaryocytes in the bone marrow.

In the bone marrow, megakaryocytes are located in the extravascular space, applied to the abluminal surface of endothelium. In this position, they send cytoplasmic projections into the lumen. Some of these projections are organelle free and may serve to anchor the cell to the endothelium. They could also serve to monitor the circulation and to receive information as to the requirement of the body for platelet formation. Megakaryocytes also send organelle containing projections into the lumen. This may be an early step in the migration of these cells into the lumen or, alternatively, part of the proplatelet formation. These proplatelets are 2.5 x 120 microns elongated structures that penetrate the lumen and can each subsequently make 1000 platelets. Each megakaryocyte can make six to eight proplatelets. In the perisinal position, megakaryocytes may subserve an adventitial function as well; many blood cells can then take a transmegakaryocytic route to reach the endothelium and enter the circulation.

Animals↗
PubMed1989

[Craniopharyngioma with malignant transformation--a report of two cases].

Two cases of a craniopharyngioma with malignant transformation are reported. Case 1 involved a 3-year-old male who had received a partial resection and radiotherapy for a suprasellar tumor. Histologically, a biopsy specimen showed craniopharyngioma. Eight years later, the child died of an intracerebral and nasopharyngeal invasion of the recurrent tumor. Case 2 involved a 9-year-old male who initially had been diagnosed as having a craniopharyngioma in the suprasellar region. Five years after the first operation, he died from growth of the tumor in spite of radiotherapy and a partial resection. The pathological examinations of these two cases showed an apparent transition of the craniopharyngioma into a squamous cell carcinoma.

Ameloblastoma↗
PubMed1989

[Intrathecal clonidine--how does it work in spinal fentanyl analgesia in rats?].

The effects of intrathecal clonidine on spinal fentanyl analgesia were studied by the hot-plate test (52.0 degrees C) in rats. Clonidine (5 micrograms) and/or fentanyl (5 micrograms) were administered alone or combined in volume of 10 microliters through a chronically-implanted polyethylene catheter (PE-10) whose tip was near the lumbar enlargement of the spinal cord. Injections were done repeatedly every two or three days to determine the time course of thermal analgesia. Results were as follows; 1) Intrathecal clonidine (n = 5) produced no thermal analgesia. 2) Intrathecal fentanyl (n = 10) produced a profound thermal analgesia which was attenuated markedly by the repeated injections in six rats before the 9th injection. 3) Two out of six fentanyl tolerated rats responded with remarkable increases in thermal thresholds following the intrathecal clonidine with fentanyl. 4) Rats which were administered with both clonidine and fentanyl from the 1st injection (n = 9) responded with a extended prolongation of the escape latency, compared with the rats which received fentanyl only. In this group, the tolerance developed in only three animals by the 9th injection. In conclusion, combined intrathecal administration of clonidine with fentanyl potentiated the analgesic effect of fentanyl and then definitely suppressed the tolerance formation even if a small dose of clonidine which produces no analgesic effect was used. These results suggest that intrathecal or epidural administration of clonidine with narcotics might be useful in managing intractable pain.

Adaptation, Physiological↗
PubMed1989

[Is massive fluid load indispensable for the parturient immediately before regional anesthesia?].

One hundred healthy parturients scheduled for elective cesarean section were studied prospectively. Fifty patients received spinal anesthesia with 12mg of hyperbaric tetracaine and were defined as the spinal group. Other fifty patients received epidural anesthesia with 300mg of lidocaine and were defined as the epidural group. A half of patients in each group were given 1,000ml of Ringer's lactate immediately before the regional anesthesia (prehydrated). Rapid hydration was not given to another half of them (non-prehydrated). In the spinal group, ephedrine administration was needed significantly less frequently for prehydrated patients than for non-prehydrated ones. And the mean dose of this drug for prehydrated patients was significantly less than that for non-prehydrated ones. In the epidural group, though prehydration tended to prevent maternal hypotension, neither rate of ephedrine administration nor mean doses of this drug showed any significant difference between prehydrated and non-prehydrated patients. Prehydration did not improve significantly neither acid-base balances of umbilical arterial and venous blood nor Apgar scores of the neonates in either group. We conclude that massive fluid load is not indispensable immediately before the regional anesthesia for the parturient. Furthermore, because this method is not reliable, its advantages and disadvantages including the possibility of enhancing pulmonary edema should be evaluated.

Adult↗
PubMed1989

[New selection criterion for Fontan procedure: pulmonary artery clamping test and pulmonary vascular resistance in increased pulmonary blood flow].

A new selection criterion for Fontan procedure, pulmonary artery clamping test (PACT) was developed and employed in 13 candidates for Fontan procedure. PACT was aimed to evaluate the response of pulmonary vascular bed to increased pulmonary blood flow and calculate the pulmonary vascular resistance in the increased pulmonary blood flow as a selection criterion for Fontan procedure, preoperatively. After a median sternotomy incision, an electromagnetic flow meter was employed for measuring the pulmonary blood flow (Qp) on the pulmonary trunk. By clamping the left pulmonary artery and the right pulmonary artery, right pulmonary vascular resistance and the left pulmonary resistance in the pulmonary blood flow of Qp were calculated respectively. By means of electrical analogue, right and left lungs were simulated as resistors in parallel. And the equivalent pulmonary vascular resistance Rpc was calculated as the predicted pulmonary vascular resistance in the increased pulmonary blood flow of two times Qp. Fontan procedure was performed in 9 cases with a Rpc of less than 3 unit.m2 with a successful result and no death. Postoperative cardiac index ranged from 2.6 to 3.7 L/min.m2 with a mean of 2.8 L/min.m2. Postoperative pulmonary vascular resistance ranged from 1.6 to 3.2 unit.m2. Postoperative cardiac index was correlated with postoperative pulmonary vascular resistance. And postoperative pulmonary vascular resistance was well correlated with equivalent pulmonary vascular resistance but was not correlated with preoperative pulmonary vascular resistance measured by Fick's method at the preoperative catheterization. In Fontan procedure, the pulmonary blood flow frequently increases to a certain degree postoperatively. And pulmonary vascular resistance is not a static resistance, but a dynamic resistance. Hence, in discussing a pulmonary vascular resistance as a selection criterion for Fontan procedure, the pulmonary blood flow in which the pulmonary vascular resistance stand should be taken into account. Equivalent pulmonary vascular resistance Qpc is a theoretical selection criterion for Fontan procedure and well reflects the postoperative pulmonary vascular resistance. Fontan procedure can be successfully performed with a Rpc of less than 3 unit.m2.

Adolescent↗