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Biomedical subjects

K Yuasa

Publications and source records attributed to K Yuasa.

At least 19 recordsLinked to original sources
PubMed1992

[Low flip angle spin-echo MR imaging to obtain better Gd-DTPA enhanced imaging with ECG gating].

ECG-gated spin-echo imaging (ECG-SE) can reduce physiological motion artifacts. However, ECG-SE does not provide strong T1-weighted images because repetition time (TR) depends on heart rate (HR). We investigated the usefulness of low flip angle spin-echo imaging (LFSE) in obtaining more T1-dependent contrast with ECG gating. in computer simulation, the predicted image contrast and signal-to-noise ratio (SNR) obtained for each flip angle (0-180 degrees) and each TR (300 msec-1200 msec) were compared with those obtained by conventional T1-weighted spin-echo imaging (CSE: TR = 500 msec, TE = 20 msec). In clinical evaluation, tissue contrast [contrast index (CI): (SI of lesion-SI of muscle)2*100/SI of muscle] obtained by CSE and LFSE were compared in 17 patients. At a TR of 1,000 msec, T1-dependent contrast increased with decreasing flip angle and that at 38 degrees was identical to that with T1-weighted spin-echo. SNR increased with the flip angle until 100 degrees, and that at 53 degrees was identical to that with T1-weighted spin-echo. CI on LFSE (74.0 +/- 52.0) was significantly higher than CI on CSE (40.9 +/- 35.9). ECG-gated LFSE imaging provides better T1-dependent contrast than conventional ECG-SE. This method was especially useful for Gd-DTPA enhanced MR imaging.

Contrast Media↗
PubMed1992

Acute pulmonary toxicity of inhaled beta-1,3-glucan and endotoxin.

The number of inflammatory cells was studied in lung walls and airways after inhalation of endotoxin or beta-1,3-glucan. In the water unsoluble form, beta-1,3-glucan caused a delayed response in terms of a decrease in macrophages and lymphocytes in the lung wall, 1 to 7 days after exposure but no invasion of neutrophils into the airways. When solubilized in 0.02 N NaOH, the cell response was the same as that observed after exposure to endotoxin.

Administration, Inhalation↗
PubMed1992

Estradiol-17 beta modifies the induction of spermidine/spermine N1-acetyltransferase activity in the liver of lipopolysaccharide-treated mice.

In an attempt to elucidate the effects of estrogen on polyamine metabolism in lipopolysaccharide (LPS)-treated mice, we assayed polyamine content and the activity of spermidine/spermine N1-acetyltransferase (SAT) and ornithine decarboxylase (ODC) in some organs. LPS elevated N1-acetylspermidine levels in the liver and lung and putrescine levels in the liver, lung and spleen. LPS increased the activity of ODC at 6 h and that of SAT at 12 h in the liver. When estradiol-17 beta was simultaneously administered with LPS, the maximum increase in hepatic N1-acetylspermidine levels was found 6 h earlier than in the LPS control. Likewise, the peak of the hepatic SAT activity after LPS-treatment was observed 6 h earlier in the estradiol-17 beta-treated mice than in the LPS control. No such effect of estradiol-17 beta was found in the lung and spleen. The LPS-induced ODC activity was not affected by estradiol-17 beta in the liver, lung or spleen. Estrone and 16 beta-ethylestradiol (an anti-estrogen) were also effective in enhancing the LPS-induced elevation of N1-acetyl-spermidine and putrescine in the liver, while both diethylstilbestrol, which has a potent estrogenic activity without steroid structure and estradiol-17 alpha (a non-estrogenic isomer of estradiol-17 beta) were without effect. Tamoxifen (an estrogen receptor antagonist) did not suppress the estrogen-induced increase in hepatic N1-acetylspermidine levels.

Acetyltransferases↗
PubMed1992

Hyperparathyroidism associated with parkinsonism.

A 70-year-old woman with hyperparathyroidism associated with parkinsonism is reported. Her primary initial symptom was parkinsonism, but it was levodopa-resistant. Chemical and hormonal findings revealed that she had hyperparathyroidism. The symptoms were relieved after the surgical removal of a parathyroid adenoma. Although this type of case has been reported only rarely, it suggests that hypercalcemia might be an aggravating factor in levodopa-resistant parkinsonism.

Adenoma↗
PubMed1992

Endotracheobronchial lidocaine concentrations during flexible fiberoptic bronchoscopy (FFB).

Lidocaine concentrations in 49 endotracheobronchial aspirates ranged from 12,580 to 23 micrograms/ml. The aspirates taken from the larger airway contained higher concentrations of lidocaine than those obtained from the smaller airway. Of the aspirates collected before 10 minutes after the final lidocaine administration, the lidocaine concentration of 7 (24.1%) of 29 specimens was greater than 3,000 micrograms/ml, however, in the aspirates collected after 10 minutes, only 1 (5%) of 20 specimens showed a concentration greater than 3,000 micrograms/ml. Using the dilution technique method (DTM) of lidocaine in the fiberscope (FS) suction channel, gradual injection of a 2 ml saline solution into the suction channel and removal of the saline solution in the suction channel were performed immediately with a suction machine; the statistically significant differences (p < 0.001) between lidocaine concentrations in the specimens before and after the DTM procedure were determined.

Administration, Oral↗
PubMed1992

[The giant cavernous hemangioma of the neck].

A 67-year-old female who had complains of dyspnea and giant mass in the right neck. The plain CT scan and selective angiography showed an giant mass in the neck and extended into antero-superior mediastinum which pressed intrathoracic trachea. The tumor was resected completely by oblique neck incision and partial median sternotomy. It was 15 x 9 x 5 cm in size. The histological diagnosis was cavernous hemangioma. The giant cavernous hemangioma in neck extended into mediastinum is rare.

Aged↗
PubMed1992

[Malignant lymphoma developing from the wall of chronic empyema following artificial pneumothorax].

A 60-year-old man who had had chronic empyema following an artificial pneumothorax for pulmonary tuberculosis when he was 26 years old developed malignant lymphoma of the chest wall. The patient was admitted because of right pyothorax as a result of pseudomonas aeruginosa infection and underwent right thoracotomy. During lavage of the right thoracic cavity a tumor was found arising from the empyematic wall. Pathologic examination revealed that it was malignant lymphoma (diffuse large, immunoblastic, B cell type). Treatment with VEAP-Bleomycin elicited a good response. Seven months after chemotherapy, the patient underwent thoracoplasty in addition to packing the cavity with the latissimus dorsi and the greater omentum. Following this, the patient received chemotherapy once a month for one and a half years, after which he was kept under close observation without treatment. Complete remission has now lasted for 49 months since the initial treatment. This is the first reported lymphoma case with closure of the empyematic wall and is remarkable since this patient has remained in complete remission for the last two years without any treatment.

Empyema, Pleural↗
PubMed1992

[Clinical evaluation of serum levels of monomeric dimeric and tetrameric pseudocholinesterases in patients with various liver diseases].

Serum levels of monomeric, dimeric and tetrameric pseudocholinesterases were measured by means of enzyme-linked immunosorbent assay in patients with various liver diseases and normal controls in order to evaluate their clinical significance. In patients with liver cirrhosis, serum levels of monomeric, dimeric and tetrameric were significantly lower than those in normal controls, patients with fatty liver and chronic hepatitis. The ratio of monomeric and dimeric to tetrameric in patients with liver cirrhosis was also significantly lower than that in normal controls, patients with fatty liver and chronic hepatitis. Serum levels of tetrameric, dimeric and monomeric were not significantly higher in the patients with fatty liver than in normal controls, but the ratio of monomeric and dimeric to tetrameric was significantly higher in patients with fatty liver than that in normal controls, patients with chronic hepatitis and liver cirrhosis. These findings suggest that the selective determinations of serum levels of monomeric, dimeric and tetrameric pseudocholinesterases are useful to estimate the metabolism of fat and protein in various liver diseases.

Adult↗
PubMed1992

[Chronic lymphocytic leukemia diagnosed after corticosteroid therapy for Evans syndrome].

A 59-year-old woman was admitted in February 1991, because of abdominal distension. On admission, she had splenomegaly, autoimmune hemolytic anemia, and idiopathic thrombocytopenic purpura. Evans syndrome had been diagnosed and daily prednisolone therapy had been performed. After this therapy, a rapid increase of lymphocytes was observed accompanied with contraction of spleen. The monoclonal proliferation of B-lymphocytes and rearrangement of JH and J kappa gene were detected and chronic lymphocytic leukemia was diagnosed. With reduction of prednisolone, the lymphocyte counts decreased and the size of the spleen returned to the previous state. It is suspected that the cause of rapid lymphocytosis in this case was due to the redistribution of lymphocytes from the spleen to the peripheral blood.

Anemia, Hemolytic↗
PubMed1992

[A case of simultaneous operation of coronary artery bypass and ascending aorta to bifemoral bypass for ischemic heart disease combined with bilateral leg ischemia].

A 58-year-old man was admitted to our hospital because of angina pectoris with severe intermittent claudication. Angiography showed triple-vessel disease of the coronary artery and complete obstruction of the bilateral common iliac arteries from their origins. Both femoral arteries were patent by collateral supplies. Combined revascularization of coronary and femoral arteries was performed. Coronary arteries were bypassed with in situ left internal thoracic artery, gastroepiploic artery and saphenous vein graft. Bilateral femoral arteries were bypassed with externally supported Dacron graft from ascending aorta through the preperitoneal space. The patient recovered well and postoperative angiography revealed all bypass grafts patent.

Aorta↗
PubMed1991

[Long-term changes in the corneal endothelium after intraocular lens implantation].

The characteristics of the corneal endothelium of 134 eyes which underwent extracapsular cataract extraction and intraocular lens implantation from 1984 to 1990 were studied. We classified the initial 29 eyes as group 1 and the most recent 105 eyes as group 2. Endothelial cell loss of group 1 was much larger than that of the latter group, reflecting the degree of surgical damage. Endothelial cell of both groups decreased with index functions. The coefficient of variation of both groups showed no significant change during the observation period. The hexagonal cells of both groups decreased once after surgery, and it increased after one year in group 1, and after three months in group 2. However the late phase of the change of hexagonal cells appeared to have no relation to the degree of surgical damage. The change of hexagonal cells was supplemented by the appearance of pentagonal cells and heptagonal cells.

Adult↗
PubMed1991

[Two cases of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with Graves' disease].

We have reported two cases of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with Graves' disease. Case 1: a 45-year-old woman noticed a diffuse goiter, palpitation and emaciation in 1977. Laboratory studies confirmed that she had Graves' disease, and she was treated with antithyroid drug. In 1986, when the hyperthyroidism was subsided, she showed progressive symmetrical weakness and numbness in her limbs, and she was almost in tetraplegia at 1987. Markedly slowed motor and sensory nerve conductions and elevated CSF proteins as well as clinical manifestations confirmed the diagnosis of CIDP. Following corticosteroid-pulse therapy and plasmapheresis resulted in good recovery in both motor and sensory impairment, though two-times of relapses were observed. Case 2: a 33-year-old man first noticed weakness in his legs in 1977, motor and sensory disturbances progressed for 12 years. Slowed nerve conduction, high CSF proteins and two-times of relapses in early phase indicated that the CIDP was the diagnosis. In 1989 he complained general fatigue, hyperhidrosis and body-weight loss. The serum thyroid hormone levels were high, and other laboratory studies confirmed the presence of Graves' disease. The cases with both CIDP and Graves' disease has rarely been reported. The background mechanism of this association is not well understood, but the susceptibility to CIDP and Graves' disease may be related to the HLA antigens and immunoglobulin Gm allotypes of which are the genes linked to the major histocompatibility complex and controlling immune responses. The present two cases commonly shared several HLA-DR antigens, but their significance should be confirmed by examining many cases.

Adult↗
PubMed1991

[Bone infarction and fat island appearing as local defects in radionuclide bone marrow imaging].

Parallel studies of radionuclide bone marrow imaging and bone scanning are helpful in the early diagnosis of skeletal metastasis. In bone marrow imaging, most lesions are observed as a local defect. We had two cases of nonmetastatic lesions which appeared as local defects in bone marrow imaging. The first case was a male Hodgkin's disease patient, aged 48, who had been treated with frequent chemotherapy, including the administration of a large quantities of steroids. He complained of slight pain in the left shoulder. Without increased uptake in bone scanning, abnormal accumulation of 67Ga-citrate and a local defect in bone marrow imaging appeared, corresponding to localization of the pain. Suspecting bone marrow metastasis, we performed magnetic resonance imaging (MRI). An area of slightly decreased intensity in T1-weighted spin-echo images and lower intensity than fat tissue in T2-weighted images were observed, although it was slightly enhanced by Gd-DTPA. This lesion was diagnosed by biopsy as a bone infarction. The second case was that of a 69-year-old male lung cancer patient. Though no abnormality was revealed by bone scanning or 67Ga-citrate scintigraphy, an apparent defect at the 10th thoracic vertebra was observed in bone marrow imaging. It was not accompanied by pain. MRI was also performed in this case. This was depicted as a clearly defined high intensity area. This was diagnosed as a fat island, and no change has been seen in the seven months of follow up. In conclusion, it is necessary to consider the possibility of nonmetastatic lesions, when local defects appear in bone marrow imaging performed on cancer patients.

Adipose Tissue↗
PubMed1990

[Post radiation changes in the rectum: assessment by MR imaging].

MRI findings of pelvic radiation changes in 42 patients were correlated with the tumor and critical tissue dose, time post treatment, and clinical symptoms. The severity of tissue changes was graded. The ability of MRI to differentiate post radiation tissue changes from residual or recurrent tumor was also correlated. Radiation tissue toxicity increased significantly when the dose exceeded 4,500 cGy, with the incidence of marked rectal changes rising from 8% to 44% with a dose greater than 4,500 cGy. All grades of tissue change were seen in the rectum of time from start of therapy. All patients who exhibited clinical grade 2 or 3 rectal changes showed moderate or severe changes on MRI. Grade 1 MRI changes indicative of mucosal edema were present in 33% of patients with no clinical symptoms. In conclusion, the gradation and sequence of MRI changes following radiation therapy to the pelvis have been documented and correlated with clinical findings. With its potential for distinguishing radiation change from recurrent tumor. MRI should prove to be of value in the assessment of the post-radiation pelvis.

Adult↗
PubMed1990

T-lymphocyte subsets as noninvasive markers of cardiomyopathy.

Fifty-eight patients with symptomatic congestive heart failure were examined for T-lymphocyte subsets in the peripheral blood using two-color laser flow cytometry as a noninvasive diagnostic procedure. The final diagnosis established by catheterization and endomyocardial biopsy were dilated cardiomyopathy (DCM, n = 24), myocarditis (MC) by the Dallas criteria (n = 12), and coronary heart disease (CHD, n = 16). The CD8+CD11- (cytotoxic T) subset was significantly low in patients with DCM (13.9 +/- 4.4 vs. controls, p less than 0.05) in comparison with MC (20.7 +/- 10.9) and CHD (22.3 +/- 5.9). Moreover, the CD4+2H4+ (suppressor/inducer T) subsets were higher in patients with DCM (27.3 +/- 6.9 vs. controls, p less than 0.01) than in those with MC (17.3 +/- 7.8) and CHD (15.6 +/- 7.9). The CD4/CD8 and CD4+2H4+/CD8+CD11- ratio were examined and compared with those of normal controls (NC n = 16). The CD4+2H4+/CD8+CD11- ratio was clearly higher in patients with DCM (2.2 +/- 0.9 vs. controls, p less than 0001) than in those with MC (1.1 +/- 0.6) CHD (0.9 +/- 0.7). A CD4+2H4+/CD8+CD11- ratio of greater than 1.6 was considered to facilitate diagnosis of dilated cardiomyopathy with 79% sensitivity and 70% specificity. There was no significant increase in the ratios between MC and CHD. However, the proportion of the CD8+Leu7+ (natural suppressor) subset of circulating T lymphocytes in patients with MC was statistically higher (19.1 +/- 6.3% vs. controls, p less than 0.05) than in DCM or CHD. An elevated ratio of CD4+2H4+/CD8+CD11- among peripheral blood lymphocytes may thus be a useful marker for differential diagnosis of dilated chronic cardiomyopathy from myocarditis and coronary heart disease.

Adult↗
PubMed1990

The influence of motor unit composition and stature on fractionated patellar reflex times in untrained men.

The purpose of the present study was to investigate the influence of muscle fibre composition and stature on fractionated patellar reflex times in ten healthy untrained men (mean age: 23.3 years, SD 3.1; mass: 65.9 kg, SD 8.5; height: 172.3 cm, SD 5.3). Biopsies were taken from the right vastus lateralis muscle. Using staining for myofibrillar adenosine triphosphatase after pre-incubation at pH 4.3 and 4.6, muscle fibres were classified into slow twitch (ST), fast twitch, oxidative-glycolytic (FTa) and fast twitch, glycolytic (FTb) fibres. Total patellar reflex time (TRT) and its fractionated components--reflex latency (LAT) and reflex motor time (MT)--were obtained from the mean of ten trials in each subject whilst performing Jendrassik's maneuvre. The TRT, LAT and MT were 77.7 ms, SD 16.5, 23.4 ms, SD 1.3 and 54.2 ms, SD 16.3, respectively. The LAT was significantly correlated to the percentage number of ST (r = 0.758, P less than 0.05) and FTa fibres (r = -0.657, P less than 0.05), fast twitch:slow twitch ratio (r = -0.799, P less than 0.01) and to the height of the subjects (r = 0.901, P less than 0.001), whereas TRT and MT were not significantly correlated with either fibre types or the height of the subjects. From these results it can be concluded that the LAT during the patellar reflex is influenced by muscle fibre composition and the length of the sensory and/or motor nerve.

Humans↗
PubMed1990

Bifemelane hydrochloride reduces plasma beta-endorphin-like immunoreactivity levels in rats.

The effect of bifemelane hydrochloride on plasma beta-endorphin-like immunoreactivity (beta-En-LI) levels in rats was studied. Bifemelane hydrochloride (25 mg/kg) was injected i.p., and the animals were decapitated at various times after the administration. The plasma beta-En-LI levels were measured by radioimmunoassay. The effect of bifemelane hydrochloride on beta-En-LI release from the anterior pituitary was also investigated by means of an in vitro experiment. The beta-En-LI content in the hypothalamus and pituitary gland did not change significantly after bifemelane hydrochloride injection. The plasma beta-En-LI levels decreased significantly in a dose-related manner with a nadir at 40 min after the injection. The beta-En-LI release in vitro from the anterior pituitary was inhibited with the addition of bifemelane hydrochloride. The findings suggest that bifemelane hydrochloride acts on the anterior pituitary to inhibit beta-En-LI release.

Animals↗