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Biomedical subjects

R Tanaka

Publications and source records attributed to R Tanaka.

At least 541 records · Page 30Linked to original sources
PubMed1990

Effects of long-term radiation exposure on chromosomal aberrations in radiological technologists.

Chromosomal aberrations in the lymphocytes of radiation technologists (RT) were analyzed by the trypsin G-banding method to study the late effects of long-term exposure to low doses of radiation. Structural aberrations were identified in 384 (2.5%) of 15,442 cells analyzed from 53 RT as compared to 177 (1.6%) of 11,136 cells from 36 healthy controls. Stable aberrations were the most frequent in both groups and were either translocations or deletions. Unstable aberrations were mainly acentric fragments in both groups. The frequency of translocations and acentric fragments was significantly higher in the RT than in the controls and was highest in the RT over 50 years. The highest frequency observed in the greater than 50 age group was attributed to the unknown for cumulative dose prior to introduction of film badges. Frequency of chromosomal aberrations correlated with the estimated dose from the film badges and years of experience of each RT based on the equation y = 0.22 + 0.37D + 4.35D2, where y is overall frequency of chromosomal aberrations and D is the estimated radiation dose in Sv.

Chromosome Aberrations↗
PubMed1990

Long-term results in a case of meningioma treated by embolization alone--case report.

A 73-year-old female, unable to walk without a cane, was hospitalized for evaluation of left sensorimotor disturbance. Computed tomographic (CT) scans revealed a large parasagittal mass, which was markedly and homogeneously enhanced by contrast material. Bilateral external carotid angiograms showed that the middle meningeal arteries supplied the tumor. Both CT and angiographic findings suggested a right frontal parasagittal meningioma. Catheter embolization with Ivalon (polyvinyl alcohol foam) particles was carried out prior to the planned surgery for the purpose of decreasing intraoperative hemorrhage from the tumor. However, her clinical symptoms began to improve 9 days after the embolization procedure, and surgery was decided against because of her advanced age and symptomatic improvement. Ten months after embolization, she was able to walk unassisted and CT scans showed a 60% reduction of the pre-embolization tumor size. Four years after embolization, she remained nearly asymptomatic despite some regrowth of the tumor.

Aged↗
PubMed1990

Reconstruction for the vertebral artery stenosis at its origin--bypass surgery using a saphenous vein graft with external shunting.

Eight patients with vertebral artery (VA) stenosis at its origin were surgically treated by a new reconstructive technique. Two patients suffered vertebrobasilar transient ischemic attacks, and five had brainstem and/or cerebellar infarction. All patients had multiple stenotic lesions, including bilateral VA stenoses in one and unilateral VA stenosis plus contralateral VA occlusion in seven. They underwent a subclavian artery to VA bypass using a saphenous short vein graft with external shunting. Postoperatively, no patients had aggravated neurological symptoms, and angiography showed all bypasses to be patent. One had an episode of transient loss of consciousness 8 months postoperatively, but the others showed no episodes of ischemia during an average follow-up period of 2 years and 10 months. The results indicate that this procedure is safer and more useful than other surgical procedures.

Aged↗
PubMed1990

[Effects of radiation on capillary endothelial cells derived from Mongolian gerbil brain].

Confluent monolayers of capillary endothelial cells derived from Mongolian gerbil brain were irradiated with a single exposure of x-rays, and their radiosensitivity and sequential changes in morphology, staining intensity for factor VIII-related antigen (F VIII RAg), and capacity to produce prostacyclin (PGI2) were examined. The radiobiologic parameters that characterized the dose-response survival curve for these cells were found to be n = 1.9, Dq = 140 rad, and D0 = 190 rad. Morphologically, nuclear and cytoplasmic swelling, vacuolation of cytoplasm, and giant cell formation occurred in a dose dependent manner after 24 hours from irradiation. Decreased staining intensity for F VIII RAg was observed in morphologically affected cells. The capacity to synthesize PGI2 was significantly enhanced at 24 hours, but less significant at 72 hours after irradiation. The present data suggest that the radiosensitivity of brain capillary endothelial cells may be somewhat lower than that of endothelial cells originated from larger vessels, and that radiation induced morphological and functional changes in the brain capillary endothelial cells may be quantitatively similar to the changes in endothelial cells of larger vessels.

Animals↗
PubMed1990

[Glomerular apolipoprotein B deposition in glomerular diseases].

In an attempt to elucidate the relationship between the progress of glomerular injury and abnormalities of lipid metabolism, we investigated glomerular deposition of apolipoprotein B (apo B) in renal biopsy specimens from 60 patients with glomerular diseases by indirect immunofluorescence using antihuman apo B-100 monoclonal antibody in comparison with clinical and histopathological findings. The patients were divided into 2 groups according to the intensity in staining of apo B in glomerulus (group A: negative or weakly positive; and group B: definitely positive). Staining of apo B in glomerulus was found in 37 patients (62%). The levels of serum total cholesterol, phospholipids, low density lipoprotein cholesterol and apo B in group B were significantly higher than in group A. The urinary protein excretion in group B was greater than that in group A. Group B was also shown to have a significantly decrease in renal function. Light microscopy revealed severe mesangial proliferation in patients with IgA nephropathy of group B. These findings suggested that glomerular apo B containing-lipoprotein deposition may play an important role in the progression of glomerular injury.

Adolescent↗
PubMed1990

[Experimental study on maturational therapy of osteosarcoma cell].

We investigated the differentiation-inducing effects of dibutyryl cyclic AMP (dBc AMP) on several cultured osteosarcoma cell lines (DUNN, MOLONEY, OST, FBJ). 1. Cell growth rates of all the osteosarcoma cell lines were reduced by 3mM dBc AMP. 2. Both alkaline phosphatase activity and 45Ca2(+)-uptake were promoted by 3mM dBc AMP. 3. There was, in each cell line except for the OST cells, a marked enlargement of the cell processes under the light microscopic observation. At the electron microscopic level, there were also many findings indicating an increase in cell functions. These results suggest that the differentiation may be induced by cAMP in osteosarcoma cells, and that the differentiation therapy by cAMP-related drugs is promising for a clinical application.

Alkaline Phosphatase↗
PubMed1990

[A case of peripheral adenoid cystic carcinoma].

A case of peripheral adenoid cystic carcinoma in a 70-year-old woman is presented. She had a coin lesion in the left upper lung field on chest X-ray film. Before one month on admission to our hospital, she noticed a tumor in the left thigh and underwent simple resection. Histological diagnosis was liposarcoma. Lung metastasis of the liposarcoma or primary lung cancer were suspected. Lung wedge resection was performed and adenoid cystic carcinoma was diagnosed. Generally adenoid cystic carcinoma originates from bronchial gland, arising in the trachea or main bronchus. In this case, the tumor originated from the peripheral lung field.

Aged↗
PubMed1990

[A case of extramedullary plasmacytoma of the mesenteric lymph nodes].

Reported here is a extremely rare case of extramedullary plasmacytoma which occurred in the mesenteric lymph nodes and could be diagnosed before operation. The ultrasound examination showed a multilobular mass, the CT examination a multilobular, homogeneous mass, and angiography a hypervascular lesion. M-protein decreased after operation.

Humans↗
PubMed1990

[A case of xanthoma of the skull].

The reports in the radiologic literature of osseous xanthoma are very rare. We reported a case of xanthoma of the skull without hyperlipidemia. The bony changes is well-marginated radiolucent lesion with marginal sclerosis and an central nidus of bone.

Bone Diseases↗
PubMed1990

[Silent myocardial ischemia in diabetics--by treadmill exercise testing].

We examined silent myocardial ischemia in diabetics by treadmill exercise testing. There were 28 diabetic men and 64 diabetic woman without angina, with a mean age of 59 +/- 11 years. Symptom-limited treadmill exercise testing was performed, and we used the electrocardiogram during exercise and immediately after exercise for judgement. ST segment depression was defined as positive if there was at least 0.1 mV of ST depression 80 ms from the J point. It was defined as negative if max heart rate (HR) was more than 80% of target HR and there was no significant ST depression. It was defined as equivocal if there was no significant ST depression but max HR was less than 80% of target HR. In 92 diabetics, 21 patients (23%) showed positive ST depression, 35 (38%) showed negative ST depression, 36 (39%) showed equivocal ST depression. In 56 diabetics exclusive of treadmill equivocal patients, 38% of patients showed positive ST depression. Treadmill positive diabetics had a significantly higher rate of smokers, patients with hypertension, and a higher triglyceride level as compared with treadmill negative diabetics. Coronary arteriography, which was performed in six treadmill positive diabetics, revealed coronary stenosis of more than 75% in four patients.

Adult↗
PubMed1990

[Polycythemia vera terminating in myelodysplastic syndrome].

A 77-year-old male, who had been treated with carboquone and busulfan for polycythemia vera (PV), developed myelodysplastic syndrome (MDS) 8 years later. On admission the peripheral blood revealed pancytopenia, but blastoid cells were not noted. The bone marrow showed hypercellularity, and functional and morphological abnormalities in trilineages of hemocytes. Cytogenetic study showed complex abnormalities involving chromosomes 5 and 7. We diagnosed this case as secondary MDS to alkylating agents. He was treated with 1, 25 (OH)2 vitamin D3. However, it was not effective and the percentage of myeloblasts increased to 14.4%. In spite of supportive therapy, he died of sepsis due to urinary tract infection.

Aged↗
PubMed1990

[Anesthetic management of patients with cardiomyopathies].

Anesthetic management of patients with cardiomyopathy was studied. In the past 8 years, we experienced 24 surgical procedures for 16 patients complicated with cardiomyopathy of whom 6 cases with hypertrophic type (HCM) and 10 cases with dilated type (DCM). In HCM there was no correlation between the incidence of intraoperative complication and preoperative evaluation by New York Heart Association. In HCM cases who revealed atrial fibrillation, conduction disturbance on ECG and hypokinesis on echocardiogram resulted in high incidence of cardiac complication during anesthesia. Induction of anesthesia is extremely risky if the anesthesiologist is not aware of the presence of cardiomyopathies. In DCM, preoperative episode of heart failure, arrhythmias and conduction disturbance on ECG were considered as anesthetic risk factors. Both in HCM and DCM, there were no statistical significance in complication between general anesthesia and epidural anesthesia. The authors recommend epidural technique as a method of choice for HCM patient.

Adult↗