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Biomedical subjects

H Doi

Publications and source records attributed to H Doi.

At least 91 records · Page 5Linked to original sources
PubMed1999

[A case of neuroaxis endodermal cyst].

The patient was a 69-year-old male. During examination of possible deafness, a cystic mass was found in the left frontal lobe, which required surgical intervention. Though the mass adhered strongly to the dura mater macroscopically, the boundary between the mass and arachnoid was clear, having a meningioma-like appearance. The pathological diagnosis was epithelial cyst consisting of layered cubic to cylindrical epithelium. It is essential to perform an electronmicroscopic or immunohistological examination for knowing the origin of an epithelial cyst in the neuroaxis, that is, of ectodermal, endodermal, or mesenchymal origin. However, the diagnosis of heterotopic endodermal cyst was established in this patient because the continuity with ependyma cells or choroid plexus was absent without the so-called ectodermogenic tissue such as glia and nerve cells.

Aged↗
PubMed1999

[Transitional cell carcinoma in the ureter showing inverted proliferation: a case report].

A case of transitional cell carcinoma in the ureter showing inverted proliferation is reported. A tumor in the middle third of the right ureter was found in a 67-year-old male complaining of gross hematuria. Since positive findings of malignancy were obtained in a washing examination of urine cytology, right nephroureterectomy was performed. The gross specimen consisted of a polypoid and pedunculated 22 x 8 mm tumor which showed a smooth surface as in normal ureteral mucosa. Histopathologically, the tumor was lined with normal transitional epithelium but filled with transitional cell carcinoma, grade 1. Diagnosis and treatment of ureteral tumors showing inverted proliferation are discussed.

Aged↗
PubMed1999

[A case of sacral meningeal cyst with Marfan syndrome].

A rare case of sacral meningeal cyst Marfan syndrome is reported. A 40-year-old male who had a past history of Marfan syndrome was admitted to Tokyo Metropolitan Ebara Hospital due to sensory disturbance in the right S1-2 nerve root area on October 1998. On admission, neurological deficits were sensory disturbance and decrease right Achilles reflex. Plain sacral X-ray was normal. Magnetic resonance imaging revealed a cystic mass in the intrasacral space. MR myelography showed the cyst followed the thecal sac. Signal intensity of the cystic mass was the same as the cerebrospinal fluid. In the prone position, laminectomy of the sacrum was carried out. The neck of the meningeal cyst was ligated with the help of an aneurysmal needle. The patient's sensory disturbance disappeared postoperatively. As MRI becomes more frequently used in Marfan syndrome, it is important to keep the presence of such an entity in mind. MR myelography made it easy to diagnose the meningeal cyst.

Adult↗
PubMed1999

Spinal epidural varices.

A 16-year-old male experienced a sudden attack of back pain while walking through the corridor of school which required emergent hospitalization. Except for the back pain, no neurological symptoms were noted. Magnetic resonance (MR) imaging indicated an angiopathy-like flow void in the epidural region at Th 3-5 which seemed to explain the patient's back pain. Thoracic laminectomy at Th 3-5 and resection of the affected site were performed. Pathologically, the resected lesion only had a dilated normal vein and no findings indicating vascular deformity. The patient's outcome was good and no relapse of pain has occurred for about 2 years since the operation. Although some authors have reported vascular deformity with spinal epidural hemorrhage or varices with lumbar hernia of the intervertebral disc, there is no report concerning spinal epidural varices with pain only. The present case seemed to be a rare event and is reported here.

Adolescent↗
PubMed1999

[An autopsy case of pericallosal lipoma with mental retardation].

The patient was a 69-year-old male who had visited our psychological department due to mental retardation. Pericallosal lipoma was indicated by MRI taken during treatment. On December 30, 1998, the patient fell from steps and struck his forehead hard, and then limb palsy occurred. He was emergently brought to our hospital. Under the suspected diagnosis of traumatic cervical spinal cord injury, preventive therapy was performed to observe the clinical course in which paralysis gradually improved. On January 22, 1999, however, he died of cardiopulmonary arrest due to sudden suffocation. In general, the connection of choroid plexus lipoma and pericallosal lipoma is bilateral in most cases. In our patients, MRI suggested that a connection with cerebral ventricles through choroidal fissure existed with no right and left difference, however, autopsy findings revealed that the lipoma existed along the left cerebral arch with obvious connection only with the left choroid plexus. The present case seemed to be a very rare case.

Aged↗
PubMed1999

[Pulmonary infarction diagnosed by transbronchial lung biopsy].

A 43-year-old man complained of chest pain, fever, and hemosputum in February 1997. Chest X-ray films revealed small opacity in the right lower lung field. The patient received therapy for pneumonia and his condition gradually improved. However, on March 21 he was admitted to our hospital with worsened chest pain and radiographic findings. A transbronchial lung biopsy revealed thrombus and necrosis, thus yielding a diagnosis of pulmonary infarction. The patient did not exhibit any underlying disease or coagulation abnormalities. Treatment with ticlopidine resulted in a favorable course. This was a rare case of pulmonary infarction in which TBLB findings led to the diagnosis.

Adult↗
PubMed1999

[Four cases of cancer of unknown primary site that manifested as mediastinal metastatic lesions].

We encountered 4 patients with cancers of unknown primary sites that were manifested by mediastinal lesions. Patient 1 was a 58-year-old man with enlarged superior mediastinal lymph nodes. An exploratory thoracotomy yielded a diagnosis of lymph node metastasis of poorly differentiated adenocarcinoma. The patient was treated with chemotherapy and radiation therapy. Patient 2 was a 68-year-old man with a tumor in the right superior mediastinum. A total resection of the tumor was performed through a thoracotomy. The diagnosis was lymph node metastasis of squamous cell carcinoma, and treatment consisted of irradiation. A tumor shadow in the right upper lobe appeared 14 months after the thoracotomy, and was considered to be a primary lesion requiring a right pneumonectomy. The patient died of hepatic metastasis 6 months after the second operation. Patient 3 was a 59-year-old man with mediastinal and hilar lymph node swelling. Mediastinoscopic findings resulted in a diagnosis of squamous cell carcinoma. Because of the patient's insistence, only radiation therapy was performed. Patient 4 was a 65-year-old woman with a tumor in the right superior mediastinum who underwent a median sternotomy for total resection of the tumor. The pathological findings were strongly suggestive of metastasis of clear cell carcinoma. Patients 1, 3, and 4 were alive 33, 24, and 51 months, respectively, after their initial operation, without detectable primary sites. Patient 2 was considered to have had T 0 N 2 lung cancer.

Adenocarcinoma↗
PubMed1999

Castability of Ti-6Al-7Nb alloy for dental casting.

Castability of Ti-6Al-7Nb alloy, CP Ti, and Co-Cr alloy was examined for mesh type and plate type specimens. The casting was carried out with a pressure type casting machine and commercial molding material. The castability of the mesh type specimen was evaluated in terms of the number of cast segments (castability index), and that of the plate type was evaluated by the area of the specimen (casting rate). X-ray images processed by a digital imaging technique were used to identify the casting porosity. The casting rate of the specimens increased with increasing thickness of the specimens. It was concluded that the castability index and the casting rate of Ti-6Al-7Nb alloy was slightly lower than that of CP Ti, and higher than that of Co-Cr alloy, were as Ti-6Al-7Nb alloy showed fewer casting porosities than CP Ti and smaller ones than Co-Cr alloy, which was advantageous for increasing the reliability of the casting properties.

Dental Alloys↗
PubMed1998

Development of obstructive hypertrophic cardiomyopathy from nonobstructive hypertrophic cardiomyopathy.

A rare case of obstructive hypertrophic cardiomyopathy (HC) with mitral regurgitation (MR) is reported, which developed over 7 years from nonobstructive HC in an elderly woman. Systolic anterior motion of the anterior mitral leaflet was the most likely cause of the outflow obstruction and mitral valve replacement combined with septal myectomy resulted in complete abolition of the outflow tract gradient and MR.

Aged↗
PubMed1998

Association of remnant lipoprotein levels with impairment of endothelium-dependent vasomotor function in human coronary arteries.

BACKGROUND: It remains undetermined whether triglyceride-rich lipoproteins are an independent risk factor for atherosclerosis. METHODS AND RESULTS: The correlation of responses of coronary arterial diameter (quantitative coronary angiography) and coronary blood flow (intracoronary flow wire technique) to intracoronary infusion of acetylcholine (10 and 50 microg/min) with coronary risk factors including remnant lipoprotein levels was statistically analyzed in 106 consecutive subjects with normal coronary angiograms. Remnant lipoproteins were isolated from fasting blood with an immunoaffinity mixed gel containing anti-apolipoprotein (apo) A-1 and anti-apoB-100 monoclonal antibodies. In multivariate stepwise regression analysis, remnant lipoprotein levels had the most significant correlation with abnormal epicardial coronary vasomotor responses to acetylcholine infusion, reflected by impaired dilation or constriction of the epicardial coronary arteries, and the levels also had an inverse and independent correlation with the coronary blood flow increase in response to acetylcholine. In a subgroup of 53 consecutive subjects, constrictor responses of epicardial coronary diameters to intracoronary infusion of NG-monomethyl-L-arginine (50 micromol/min for 4 minutes) at baseline, reflecting the presence of coronary nitric oxide bioactivity, had an inverse and independent correlation with remnant lipoprotein levels by use of multivariate analysis. CONCLUSIONS: Remnant lipoprotein levels were independently associated with abnormal endothelium-dependent vasomotor function in large and resistance coronary arteries in humans, indicating that remnant lipoproteins may impair endothelial vasomotor function in human coronary arteries. The decrease in coronary nitric oxide bioactivity may be responsible in part for the inhibitory effects of remnant lipoproteins.

Acetylcholine↗
PubMed1998

Supersensitivity of atherosclerotic artery to constrictor effect of cigarette smoke extract.

OBJECTIVE: The aim of this study was to assess whether contractile response of arteries to aqueous component of cigarette smoke extract (CSE) may be modulated in atherosclerotic arteries. METHODS: Thoracic aortas were isolated from control rabbits and from 1.5% cholesterol-fed rabbits, all of which had visible advanced atheromatous surface changes on the aortas. CSE was prepared by bubbling main stream of smoke from one cigarette with filter into 2 ml of phosphate-buffered saline. The thoracic aortic rings were suspended in organ chambers and tested with CSE (0.01-3.0 microliters/ml buffer in the organ chamber) after precontraction with 0.1 mumol/l of phenylephrine (PE). RESULTS: The contractile response to CSE was significantly greater in atherosclerotic aortas than in control aortas (the maximal contraction expressed as % of the precontraction; control aortas 10.8 +/- 2.8%, atherosclerotic aortas 42.6 +/- 4.7%; P < 0.01). The magnitude of the precontractions by PE was not different between control and atherosclerotic aortas. Exogenous addition of superoxide dismutase (SOD) significantly attenuated the CSE-induced contraction in both control and atherosclerotic aortas and pretreatment of aortic rings with diethyldithiocarbamate to deplete of endogenous vascular CuZn-SOD activity potentiated the CSE-induced contraction in control aortas, while it had no significant effect in atherosclerotic aortas. The vascular SOD activity was significantly lower in atherosclerotic aortas than in control aortas ((U/mg protein): control aortas 38.2 +/- 3.3, atherosclerotic aortas 18.5 +/- 2.4; P < 0.01). CONCLUSION: These results indicate that atherosclerotic arteries may be supersensitive to the constrictor effect of superoxide anion derived from CSE. The decrease in endogenous vascular SOD activity may partly contribute to the increased susceptibility to oxidative stress in atherosclerotic arteries.

Animals↗
PubMed1998

Remnants of chylomicron and very low density lipoprotein impair endothelium-dependent vasorelaxation.

Remnants of chylomicron and very low density lipoprotein (VLDL) have been implicated as potentially atherogenic. Since endothelial dysfunction is an early event in atherosclerosis, we examined effects of the remnants on endothelium-dependent vasorelaxation. The remnant lipoproteins were isolated from postprandial plasma in hyperlipidemic subjects using the immunoaffinity gel mixture of anti apo A-1 and anti apo B-100 monoclonal antibodies and ultracentrifugation. Rabbit aortic strips suspended in the organ chambers were incubated for 2 h with the preparations of lipoproteins and lipids. After incubation, the strips were tested with vasodilators after precontraction with phenylephrine (1 microM). The remnant lipoproteins (750-1500 microg triglyceride/ml) but not VLDL fraction (up to 1500 microg triglyceride/ml) impaired vasorelaxation in responses to acetylcholine, substance P and A23187. Carbamylated or methylated remnant lipoproteins, chemically modified remnant lipoproteins, had comparable impairment of the vasorelaxation as unmodified remnant lipoproteins. Incubation with lipid extracts from the remnant lipoproteins also exerted an inhibitory effect on the vasorelaxation. Relaxation to sodium nitroprusside was fully preserved in all aortas exposed to the lipoprotein preparations. Thus, the remnant lipoproteins impair endothelium-dependent arterial relaxation at the concentrations observed in the plasma in patients with coronary artery disease (500-2000 microg triglyceride of remnant lipoprotein/ml). The impairment may be in apoprotein receptor-independent manner, and the lipids in the remnants seem to contribute to the inhibitory effect. The endothelial dysfunction caused by the remnant lipoproteins may play a role in the high prevalence of atherosclerotic coronary artery disease in postprandial hyperlipidemic patients.

Acetylcholine↗
PubMed1998

Effect of valine-depleted total parenteral nutrition on fatty liver development in tumor-bearing rats.

Valine-depleted amino acid imbalance, while having a suppressive effect on tumor growth, may induce fatty liver. We administered valine-depleted total parenteral nutrition (TPN) solution to rats subcutaneously transplanted with ascites containing hepatoma AH-109A and examined the time course of the development of fatty liver. An accumulation of fatty vacuoles was observed in hepatocytes on day 4. To prevent the development of fatty liver in tumor-bearing rats, we administered a small amount of valine in addition to the valine-depleted imbalance solution via the central vein. Such treatment, however, resulted in neither the prevention of fatty liver development nor the suppression of tumor growth. To supply valine to the liver, we administered a low concentration of valine via the portal vein simultaneously with central venous administration of valine-depleted TPN solution. As a result, the peripheral blood valine level of these rats was < 0.5 that of the control group, but the valine in the liver was maintained at the same level as that of the control group, and accumulation of triacylglycerols in the liver was slight. However, the suppressive effect on tumor growth was maintained, as the tumor weight was suppressed to almost the same degree as that of rats administered only the valine-depleted solution.

Amino Acids↗
PubMed1998

Amount of hydroxyl radical on calcium-ion-implanted titanium and point of zero charge of constituent oxide of the surface-modified layer.

To compare the surface properties of calcium-ion (Ca2+)-implanted titanium with those of titanium and to investigate the mechanism of bone conductivity of Ca2+-implanted titanium, amounts of hydroxyl radical of Ca2+-implanted titanium and titanium were estimated. Also, the point of zero charge (p.z.c.) of oxide constituting surface oxides of Ca2+-implanted titanium and titanium was determined. Results showed that the amount of active hydroxyl radical on Ca2+-implanted titanium was found to be significantly larger than that on titanium, indicating that the number of electric-charging sites of Ca2+-implanted titanium in electrolyte is more than that of titanium. The p.z.c. values of rutile (TiO2), anatase (TiO2), and perovskite (CaTiO3), were estimated to be 4.6, 5.9, and 8.1, respectively. Thus, Ca2+-implanted titanium surface is charged more positively in bioliquid than titanium, accelerating the adsorption of phosphate ions.

Journal Article↗