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Biomedical subjects

K Yuasa

Publications and source records attributed to K Yuasa.

At least 37 records · Page 2Linked to original sources

Multimodality imaging of cervicofacial actinomycosis.

Actinomycosis is an uncommon chronic disease usually caused by Actinomyces israelii. It affects the soft tissue mainly but sometimes spreads to involve salivary glands, bone, or even the skin of the face and neck. Five cases have been seen in our department. Several imaging modalities were used to assist in making the diagnosis. The cases are presented and the literature reviewed. Ultrasonography was found to be a useful diagnostic tool especially in developing the differential diagnosis.

Actinomycosis

Computed tomography of the jaws in familial adenomatosis coli.

Familial adenomatosis coli is known to be associated with tooth impactions, odontomas, and osteomas. Three cases were examined by panoramic radiography and computed tomography. Computed tomography was especially useful for detecting osteomas in the maxilla and also revealed a wavy cortical thickening in the mandible in one instance. The latter finding has been reported for other bones in the body but not previously for the mandible.

Child

Quantification of occlusive and reperfused myocardial infarct size with Gd-DTPA-enhanced MR imaging.

The potential of Gd-DTPA-enhanced magnetic resonance imaging (MRI) for measuring infarct size was assessed in canine hearts. Twelve dogs underwent pre- and post-contrast MR imaging before and after recanalization. Infarct area was identified by triphenyltetrazolium chloride (TTC) staining of postmortal specimens in each case. Recanalization was complete in 10 dogs. High SI area was seen after reperfusion in nine of them; and it showed low signal intensity before reperfusion in seven of them. Two dogs were killed during reperfusion period: neither of them showed a low SI area before reperfusion. Necrotic regions were confirmed by TTC staining in seven of 12 dogs. Both the visual and quantitative assessment (n = 7) indicated that the extent of the low SI area before reperfusion was approximately the same as that of the necrotic region shown by TTC staining, while the high SI area seen after reperfusion was obviously larger than both the necrotic region and the low SI area on pre-reperfusion images. The correlation coefficient between low SI area and necrotic area was 0.98, and between high SI area and necrotic area was 0.80. These results suggest that Gd-DTPA-enhanced MRI may be useful for quantification of infarct size in occlusive myocardial infarction but it may overestimate in reperfused one.

Animals

Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging.

In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute myocardial infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR = 0.68 +/- 0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR:1.76 +/- 0.34). We conclude that Gd-DTPA- enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration.

Animals

Analysis of maxillary sinusitis using computed tomography.

Odontogenic maxillary sinusitis can be defined as sinusitis induced by a dental lesion. We examined the CT findings of 68 patients with maxillary sinusitis in order to differentiate between inflammation of sinus origin and inflammation of dental origin. Maxillary sinusitis was classified into four types according to clinical symptoms, history and conventional radiographic findings: type 1, simple sinusitis; type 2, odontogenic sinusitis; type 3, mixed sinusitis; type 4, slight sinus abnormality with a dental lesion. The relationship between the type of maxillary sinusitis and CT findings was analysed. Type 1 sinusitis exhibited severe pathological changes in both mucosa and bone which often extended into the nasal cavity and other paranasal sinuses. Type 2 sinusitis exhibited localized pathology on the unilateral antral floor. Type 3 sinusitis exhibited severe pathology characteristic of type 1 combined with type 2 sinusitis. Type 4 sinusitis could be differentiated by the CT findings into type 1 or type 2 sinusitis. The classification of sinusitis in this manner has implications for treatment planning, and CT should therefore be performed when conventional radiography does not provide sufficient information.

Female

[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

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

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

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

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

[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

[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

[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

[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

[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

[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

[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