Biomedical subjects

A Kurata

Publications and source records attributed to A Kurata.

At least 109 records · Page 6Linked to original sources

PubMed1992

Choroid plexus arteriovenous malformations.

Among 24 arteriovenous malformations (AVMs) involving the choroid plexus, 11 were plexal type AVMs predominantly located in the choroid plexus of the lateral ventricle, and 13 were parenchymal type AVMs mainly situated in the paraventricular cerebral parenchyma. 83% of all AVMs involved both the choroid plexus and the paraventricular cerebral parenchyma. Most cases presented with intracranial hemorrhage, particularly intraventricular hemorrhage. The most serious surgical problem was a small residual nidus unrecognized at the initial operation causing postoperative hemorrhage. Five parenchymal type AVMs presented residual niduses in the choroid plexus, causing death in two cases. Two plexal type AVMs resulted in residual AVMs supplied by the cisternal segment of the anterior choroidal artery, situated in the medial temporal lobe. To prevent postoperative hemorrhage from a small residual nidus, immediate postoperative angiography while the patient is still under general anesthesia should be performed to identify any residual nidus.

Adolescent↗

PubMed1992

An analysis of the venous drainage system as a factor in hemorrhage from arteriovenous malformations.

The authors studied the venous drainage system and its impairment in relation to risk of hemorrhage in 108 cases of supratentorial arteriovenous malformation (AVM). The proportion of AVM's undergoing hemorrhage (hemorrhagic rate) was calculated in relation to: 1) the number of draining veins (one, two, or three or more); 2) the presence or absence of impairment in venous drainage (severe stenosis or occlusion in draining veins); and 3) the location of draining veins (deep venous drainage alone, superficial venous drainage alone, or a combination of the two). Statistical analysis demonstrated that AVM's with the following characteristics had a high risk of hemorrhage: 1) one draining vein (hemorrhagic rate 89% in 54 patients); 2) severely impaired venous drainage (hemorrhagic rate 94% in 18 patients); and 3) deep venous drainage alone (hemorrhagic rate 94% in 32 patients). The present study suggests that the venous drainage system of AVM's is significantly associated with the risk of hemorrhage of these lesions. Therefore, careful preoperative angiographic evaluation of the venous drainage system is mandatory for decision making in the management of patients with AVM's.

Cerebral Hemorrhage↗

PubMed1992

[Transitional cell carcinoma of the ureter with inverted proliferation: a case report].

A case of transitional cell carcinoma of the ureter with inverted proliferation is presented. A 74-year-old man with the chief complaint of asymptomatic macrohematuria was referred for a suspicion of a ureteral tumor. Excretory urography demonstrated a filling defect with a round smooth contour in the right lower ureter. Urine cytology was negative for malignant cells. No bladder tumor was noted by cystoscopic examination. Under the clinical diagnosis of a right ureteral tumor, right total nephroureterectomy was performed. The gross specimen contained a 2.0 x 1.0 cm, polypoid, pedunculated and smooth-surfaced tumor. The pathological diagnosis was transitional cell carcinoma with inverted proliferation G2 much greater than G1. Malignant tumor with inverted proliferation in the ureter is very rare. In Japan, 8 cases of transitional cell carcinoma with inverted proliferation in the ureter, including our case, are reviewed.

Aged↗

PubMed1992

[A case of retroperitoneal venous aneurysm].

A case of retroperitoneal venous aneurysm is reported. A 73-year-old woman was referred to us with the chief complaint of left abdominal mass. A giant abdominal mass was palpable and diagnostic imaging examination including ultrasound tomography, excretory pyelography, computed tomography, magnetic resonance imaging and angiography revealed a giant cystic mass encircled by calcification in the left retroperitoneal space. Operation for this cystic mass was performed under the preoperative diagnosis of a giant left renal cyst. During operation the mass was located between the left kidney and the left adrenal gland. Because it was difficult to separate the mass from the left kidney the mass was removed with the left kidney. The extirpated tumor measured 15.5 x 15.0 x 9.5 cm and contained old blood clots and red-yellow colored fluid. A histological examination revealed that the tumor wall was composed of smooth muscle and elastic fibers. Therefore, pathological diagnosis was retroperitoneal venous aneurysm. Retroperitoneal venous aneurysm is very rare. To our knowledge, this is the 8th case of retroperitoneal venous aneurysm reported in Japan.

Aged↗

PubMed1992

[Surgical treatments of nonconfluent pulmonary arteries with congenital cardiac defects].

Pulmonary artery angioplasty or reconstruction was performed in seven patients with nonconfluent pulmonary arteries and congenital cardiac defects. Age of these patients were ranged from 6 months to 41 years old. Five of them had pulmonary truncal atresia and complex cardiac anomalies. Two of these five patients demonstrated nonconfluent pulmonary arteries due to deformities at ductal insertion of pulmonary arteries. Three patients had had previous systemic to pulmonary artery shunt operations which caused pulmonary artery distortions. Other two patients had intrapulmonary arterial obstructions due to pulmonary artery thrombosis. Patch pulmonary artery plasty was carried out in three patients, dilatation of severe stenotic pulmonary artery was done in one patient simultaneously with pulmonary valvotomy. Central shunt operation was added in one patient with the pulmonary artery which was unable to be reconstructed. Last two patients underwent intrapulmonary artery reconstruction with the rolled pericardial graft. Hospital death occurred in one patient with unproperly increased pulmonary blood flow by central shunt. Average follow-up period of these six survivors after operation was 1.4 +/- 0.8 years. As definite repairs, two patients had Fontan operation, two patients had right ventricle to pulmonary artery reconstruction. And remaining two patients are still to be followed until sufficient growth of pulmonary artery suitable for Fontan operation.

Adolescent↗

PubMed1992

[Experience with BALT magic catheter (PURSIL catheter); especially investigation about advantage, disadvantage and the applications].

BALT magic catheter (PURSIL catheter) is a new catheter which is more flexible and plaint than the TRACKER-18 catheter because its mid-section and distal portion are made from polyurethane and silicon rather than polyethylene. Because the PURSIL catheter is flexible, it cannot be inserted with a guide wire, although it can be inserted into circulation during injection of contrast medium. Its inner diameter, 3.5mm, is smaller than that (5mm) of the TRACKER. There are few reports of embolization with the PURSIL catheter, and these describe only embolization using adhesive liquid embolus material. Embolization using small particles through the PURSIL catheter has never been reported. We report the catheterization using the PURSIL catheter of 26 arteries in 15 patients. The catheter was used for superselective angiography to clarify feeder and amytal tests in 5 patients with AVM, and embolization using PVA particles (150-250 microns) was performed in 1 patient with AVM, 3 patients with dural AVM, 4 cases with meningioma and 1 patient with vertebral aneurysm. Small PVA particles were easily injected without resistance through this catheter. In only one patient with dural AVM, was catheterization with this catheter not successful, and that was because the distal portion of the internal maxillar artery was extremely tortuous because of severe atherosclerosis. No complications associated with the use of this catheter were observed. We think that the greatest advantage of this catheter is the safety afforded by not using a guide wire. A disadvantage of this catheter is that, because of its small inner diameter, only small particles, or liquid embolus material can be injected through it.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Anti-C100-3 antibody titration using 4-parameter logistic curve (results in its application to hepatitis C cases treated with interferon].

We evaluated titers of C100-3 antibody by ELISA using a 4-parameter logistic fitting curve and examined the transition of the values in the cases of interferon treatment. The 4-parameter logistic fitting curve produced a standard curve in a wider range using a micro plate reader than the logarithmic curve. The values of C100-3 antibody during and after the treatments of interferon were changed in parallel with the alterations of ALT. The anti-C100-3 antibody titers assayed in the complete or partial responders were significantly reduced at the end of interferon therapy. These findings suggest the clinical usefulness of the evaluation of anti C100-3 antibody titers.

Antigens, Viral↗

PubMed1992

[Preoperative embolization for meningiomas using PVA particles].

Preoperative embolization for highly vascularized and large meningiomas is an indispensable technique for facilitating their surgical removal by decreasing blood loss during the operation. This is a report of 4 large and highly vascularized meningiomas in the skull base, on which embolization of feeders was performed preoperatively by PVA (Polyvinyl alcohol foam) particles (150-250 micron produced by INGENOR CO, Paris) and small strips of gelfoam (0.5 x 0.5 x 3-5mm). Under EEG monitoring, Isosorbide dinitrate was used for prevention and relief of vascular spasm. Lidocaine injection tests (Xylocaine 2%: 50mg mixed in equal volumes with Iopamiron 300) were performed for checking before embolization. In the intracranial portion, standard taper steerable guide wire was changed to seeker flexible soft-tip guide wire. In two cases, the meningioma was located in the medial part of the sphenoidal ridge. In the other two cases, one meningioma was in the lateral part of the sphenoidal ridge and the other was in the olfactory groove. In all 4 cases, we successfully performed embolization without complication. In one case, we had to perform embolization twice, because of revascularization detected by angiography 3 weeks after the first embolization. In this latter case, we had performed central embolization only, by using PVA particles, having left feeder without occlusion (peripheral embolization) using gelfoam. The result suggested that it was also necessary to perform peripheral embolization especially if the tumor is fed by large tortuous and irregular abnormal vessels. Peripheral embolization may prevent PVA particles from washing out and causing progressive thrombosis by PVA particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Primary carcinoma in situ of the upper urinary tract: a case report].

A case of primary carcinoma in situ of the upper urinary tract in a 72-year-old woman is reported. The patient who complained of left lower abdominal pain was referred for a suspicion of left ureteral stone. An excretory pyelogram showed mild left ureteral stricuture at the level of L3, but a stone was not detected in the ureter at the same level. Cytology of voided urine was positive for malignant cells several times. Cystoscopic examination revealed no abnormality in the bladder. Retrograde left pyelogram demonstrated the ureteral stricture and no lesions either of stone or tumor in the ureter. However malignant cells were detected cytologically in the left ureteral catheteral urine. Left total nephroureterectomy with the bladder cuff was carried out under the preoperative diagnosis of carcinoma in situ of the upper urinary tract. Macroscopically, the wall of the ureter at the stenotic level had induration without apparent tumor mass. The pathological diagnosis was transitional cell carcinoma in situ from the renal pelvis to the mid-ureter. The primary carcinoma in situ of the upper urinary tract is rare. To our knowledge, this case is the 26th case reported in the Japanese literature.

Aged↗

PubMed1992

[Adrenal myelolipoma associated with Cushing's syndrome: a case report].

A 42-year-old woman was referred to our hospital for evaluation of severe hypertension. A right adrenal tumor was revealed by CT scan, and the elevation of cortisol and u-17OHCS was found. We made a diagnosis of adrenal adenoma with Cushing's syndrome and performed right adrenalectomy. However, a small myelolipoma (1.5 mm in diameter) was found beside the cortical adenoma by histopathological examination. Adrenal myelolipoma is not a rare disease now, because it is easily-detected as an incidental by CT scan. The present case of adrenal myelolipoma, however, is interesting and uncommon in its connection with functioning cortical adenoma. Only 3 cases have been previously reported so far in English and Japanese publications. We discuss the etiology of adrenal myelolipoma, and suggest that myelolipoma would develop in the course of regressive or necrotic degeneration of cortical cells by hormonal disorders, stress, circulatory disturbance or other unknown factors.

Adenoma↗

PubMed1991

Effects of lobenzarit disodium on human endothelial cells. Lobenzarit disodium inhibits proliferative response, HLA-DR antigen expression, and T cell adherence toward endothelial cells.

The therapeutic action of lobenzarit disodium (CCA) on the function of endothelial cells (EC) isolated from human umbilical cord veins was investigated. CCA suppressed 3H-thymidine incorporation into EC in a dose-dependent manner. Significant inhibition was detected at a concentration of 50 micrograms/ml. The expression of HLA-DR antigen on the surface of EC was increased when EC were cultured with recombinant interferon-gamma (rIFN gamma). Treatment of EC with either IFN gamma or interleukin-1 enhanced the adhesion of T cells to EC. The kinetics of HLA-DR antigen expression by EC cultured with IFN gamma was different from the kinetics of T cell-EC adhesion, however. Neither anti-HLA-DR nor anti-HLA-ABC monoclonal antibody inhibited T cell binding to EC monolayers. CCA suppressed the expression of HLA-DR antigen by EC cultured with rIFN gamma. In an EC monolayer adhesion assay, CCA also inhibited T cell adhesion to EC in the presence of either IFN gamma or interleukin-1. Significant inhibition was observed at a CCA concentration of 10 micrograms/ml, a level that is easily attainable in serum. These results suggest that CCA may suppress rheumatoid synovitis by reducing the angiogenesis and emigration of chronic inflammatory cells from the blood into the synovium.

Cell Adhesion↗

PubMed1991

Histiocytic neoplasias: immunohistochemical evaluation of their frequencies among malignant lymphoma and related conditions in Japan.

Through histologic review of 1,766 cases with malignant lymphoma and related conditions, 35 cases (2%) were selected as probable histiocytic neoplasias. Proliferating cells in these cases had voluminous, granulated cytoplasm, and round to irregularly shaped nuclei often with bi- or multinucleated forms showing monomorphous or polymorphous proliferation accompanying small lymphocytes, plasma cells, and, less frequently, eosinophils. Cases showing proliferation of convoluted cells with numerous benign-appearing histiocytes or large cells with clear cytoplasm were excluded under a diagnosis of T-cell lymphoma. To evaluate the immunologic character of proliferating cells, immunohistochemistry using antibodies Mx-Pan B, MB-1, MT-1, UCHL-1, lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, S-100 alpha, S-100 beta, Leu M1, epithelial membrane antigen, and Ki-1 were carried out in 23 cases. Naphthol-ASD-chloracetate reaction and toluidine blue stain were also performed. These procedures revealed that 12 cases (52%) were B-cell type, three cases (13%) T-cell type, six cases (26%) true histiocytic type, and two cases null type. Therefore, the frequency of cases with true histiocytic neoplasias among cases with malignant lymphoma and related conditions in Japan may be 0.5%.

Antibodies, Monoclonal↗

PubMed1991

Different B-cell responses to human T-cell lymphotropic virus type I (HTLV-I) envelope synthetic peptides in HTLV-I-infected individuals.

HTLV-I (human T-cell lymphotropic virus type I) is the retrovirus related to two distinct diseases, adult T-cell leukemia/lymphoma (ATLL) and HTLV-I-associated myelopathy (HAM). We analyzed the difference in antibody activities against the viral protein and the difference in specificities of anti-HTLV-I envelope antibodies among HTLV-I-infected individuals from the same HTLV-I-endemic area using a HTLV-I-gag-env hybrid protein and HTLV-I-env-encoded synthetic peptides as antigens, respectively. The difference in the responses of IgG anti-HTLV-I envelope antibody production among HTLV-I-infected individuals was qualitative as well as quantitative. Sera from patients with HAM showed significantly higher activities of antibodies against HTLV-I-gag-env hybrid protein than sera from other HTLV-I-infected individuals including ATLL patients. The specificities of IgG anti-HTLV-I-envelope antibodies, tested on seven synthetic envelope peptides, were directed mainly against four sites, V1E7 (residues 97-111), V1E8 (191-209), and V1E9 (268-286) on gp46 and V1E1 (342-363) on gp21. Three of these sites were shown to be immunodominant T-cell sites in mice in our previous study. Whereas patients in all categories made antibodies specific for V1E1 and V1E8, only HAM patients made antibodies to the V1E7 and V1E9 epitopes, suggesting a qualitative difference in response. Whether this difference is of pathogenetic significance is not clear.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1991

Synergistic effects of phorbol ester and interferon-alpha: target cell class I HLA antigen expression and resistance to natural killer and lymphokine-activated killer cell-mediated cytolysis.

This study was undertaken to investigate whether target cell class I HLA antigen expression induced by phorbol ester and interferon-alpha (IFN-alpha) was associated with resistance to natural killer (NK) cells and lymphokine-activated killer (LAK) cell-mediated cytotoxicity. Class I antigen expression on the surface of the K562 erythroleukemia cell line was enhanced by either IFN-alpha or phorbol ester (PDBu). Addition of PDBu together with IFN-alpha had a synergistic effect on class I antigen expression on the cells. Furthermore, synergism between IFN-alpha and PDBu was also found in class I antigen expression by MOLT-3 cells. This synergistic effect on class I antigen expression was blocked by the protein synthesis inhibitor (cycloheximide). Pretreatment of K562 cells with PDBu and IFN-alpha made them more resistant to lysis by NK and LAK cells than did either PDBu or IFN-alpha. In contrast to PDBu, 4 alpha PDD, a biologically inactive phorbol analogue, alone or combination with IFN-alpha, had no effect on class I antigen expression and susceptibility to lysis by NK and LAK cells. Kinetic experiments showed an inverse relationship between the expression of class I antigens and susceptibility to NK cell-mediated cytolysis. Using cold target competition analysis, target cells pretreated with PDBu and IFN-alpha clearly competed less effectively than did untreated cells for lysis of untreated target cells. These results demonstrate that target cells pretreated with PDBu and IFN-alpha decrease their sensitivity to natural killer and lymphokine-activated killer cells inversely with target cell class I HLA antigen expression.

Cell Line↗

PubMed1991

Hemorrhagic venous infarction after excision of an arteriovenous malformation: case report.

A case of arteriovenous malformation (AVM) in which postoperative hemorrhagic infarction developed, probably because of occlusion of the former draining veins, is reported. The hemorrhage developed in the temporal lobe 3 days after the initial operation and was located in the immediate vicinity of the site of the AVM. The following findings suggest that the postsurgical hemorrhage probably resulted from a venous thrombosis: 1) no evidence of residual AVM; 2) delayed onset of the hemorrhage, inconsistent with the time course of a hemorrhage developing according to the breakthrough theory or with insufficient hemostasis with a high-pressure afterload; 3) good correlation between the location of the hemorrhage and the occlusion of the draining veins; and 4) multifocal hemorrhage affecting both the gray matter and the subcortical white matter. Postoperative hemorrhagic infarction caused by thrombosis in the draining veins is rare, but it should be considered as a distinct postoperative complication after removal of an AVM.

Cerebral Hemorrhage↗

PubMed1991

Detection of Leu-19 (CD56) antigen on human thyroid epithelial cells by an immunohistochemical method.

The Leu-19 (CD56) antigen, which is recognized by anti-Leu-19 and NKH-1 monoclonal antibody, is a 200,000-220,000 molecular weight (MW) glycoprotein that is expressed predominantly on human natural killer (NK) cells that mediate major histocompatibility complex (MHC)-unrestricted cytotoxicity. However, cross-reactivity of this antibody has been observed in lung cancer, and in muscle and neural tissues. In the present study, we used the immunoperoxidase technique to examine the expression of Leu-19 antigen in human thyroid epithelial cells. In normal thyroid tissues (n = 4), thyroid tissues from Graves' patients (n = 7) and benign thyroid tumours (n = 7), thyroid epithelial cells expressed Leu-19 antigen in all cases. In thyroid papillary carcinoma (n = 6) there was no expression in four cases. This staining pattern of anti-Leu-19 antibody is similar to that of anti-thyroid peroxidase antibody. These findings implicate that the expression of Leu-19 antigen is closely related to the differentiation of thyroid epithelial cells.

Antigens, CD↗

PubMed1991

[A case of aortitis syndrome complicated with amyloidosis, type AA].

We recently saw a patient who had aortitis syndrome associated with secondary amyloidosis. To our knowledge, she is the fourth report of this complication occurring in aortitis syndrome. In November 1985, the patient, a 18 year-old woman, was admitted to our hospital because of a high fever, back pain, abdominal pain and general fatigue. On physical examination, bruit was audible on the abdomen, bilateral radial artery was weakly palpable. Angiography showed the stenosis of bilateral carotid artery, subclavian artery, renal artery and superior mesenteric artery. From the above findings, she was diagnosed aortitis syndrome, and treatment was begun with prednisolone. However, she developed recurrently a high fever, chest pain, abdominal pain and exertional dyspnea. Laboratory findings at the active stage revealed the marked elevation of leukocytes, erythrocyte sedimentation rate and C-reactive protein. On her clinical course, the number of circulating thrombocytes was paralleled with the activity of the disease. On June 1988, she developed suddenly a high fever and severe pain of abdomen. Pathological findings of her stomach showed the deposition of amyloid protein A. Laboratory findings depicted the marked increment of thrombocytes, beta-thromboglobulin and platelet factor 4. These results suggest that circulating thrombocytes may play a role in product ion of amyloid protein.

Adult↗

PubMed1991

[Benign hemorrhagic renal cyst: a case report].

A case of benign hemorrhagic renal cyst in a 64-year-old man is reported. The patient was admitted to our hospital for further evaluation of left upper abdominal mass. CT scan and ultrasonic sonography showed a left giant renal cystic mass. The characteristic findings were thick and irregular wall and heterogeneous contents of the cystic mass. Selective renal arteriography showed a hypervascular area in a part of the cyst wall and hemorrhagic cyst was suspected by MR imaging. The presence of a malignant tumor in the cyst wall was suspected, and radical nephrectomy was performed. The specimen measured 18 x 12 x 8 cm and weighed 1,170 g. The cyst contained bloody fluid and a hemorrhagic degenerating mass. Pathohistological examination showed no evidence of malignant tumor at any site of the cyst wall.

Hemorrhage↗