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Biomedical subjects

A Kurata

Publications and source records attributed to A Kurata.

At least 73 records · Page 4Linked to original sources
PubMed1996

Dural-pial arteriovenous malformation with unusual venous drainage.

A 41-year-old female presented with an uncommon mixed dural-pial arteriovenous malformation (AVM) with unusual venous drainage. Angiography at the initial operation for massive intracerebral hematoma in the parietal lobe showed no vascular malformations. Follow-up angiography 3 years later revealed a mixed dural-pial AVM at the previous surgical site. Unexpectedly, the venous drainage from the AVM was not into the patent superior sagittal sinus, but was retrograde into the contralateral cortical veins in the occipital lobe. No skull fracture or sinus thrombosis was demonstrated. The AVM was resected successfully without neurological deterioration. The pial portion of the lesion may have been a congenital anomaly, and the dural portion acquired. The development of a dural AVM at an earlier surgical site is uncommon, and may indicate the possible pathogenesis of acquired dural AVMs unrelated to sinus occlusion or accidental trauma. Furthermore, there are various possible patterns of venous drainage in vascular malformations.

Adult↗
PubMed1996

Involvement of Epstein-Barr virus expression in testicular tumors.

PURPOSE: Because orchitis has been described as a symptom of infectious mononucleosis which is caused by Epstein-Barr virus (EBV), a human tumor virus, we tried to ascertain the relationship between EBV and testicular tumors. MATERIALS AND METHODS: Sixteen seminomas, 11 embryonal carcinomas and 25 nonmalignant control testes were examined for persistence and expression of the EBV genome. To detect expression of EBV, mRNA in situ hybridization and immunofluorescence staining by monoclonal antibodies were performed. To confirm the EBV genome in testes, we used nested polymerase chain reaction (PCR). RESULTS: Messenger RNA in situ hybridization showed that all 27 seminomas and embryonal carcinomas expressed EB viral RNA, but the 25 nonmalignant testes did not. Monoclonal antibody staining showed EBV-related nuclear antigen (EBNA) 2 and latent membrane protein (LMP) 1 expression in testicular tumors. Nested polymerase chain reaction detected the EBV genome in normal testes as well as in testicular tumors. CONCLUSIONS: These results suggest that EBV is related to testicular tumors.

Antigens, Viral↗
PubMed1996

Strategy for breast conserving treatment--analysis of recurrence and prognosis after breast cosnserving treatment.

Two hundred and four patients with small breast cancer (T < or = 3.0 cm. N0 or N1a) were given breast conserving treatment (radiation group: 101, non-radiation group: 103) during the period from Feb. 1988 to Jan. 1995. Survival analysis of breast conserving treatment radiation group versus non-radiation group revealed the following: 1) Breast conserving treatment had a good prognosis, and a 5-year overall survival rate of 96.2%. 2) There was no significant difference of 5-year overall, disease-free and ipsilateral breast disease-free survival rate between the radiation group and non-radiation group. 3) Surgical margin involvement was the most significant risk factor in local recurrence after breast conserving treatment, and non-radiation was a possible risk factor. 4) Local recurrence was a significant risk factor for distant metastases after breast conserving treatment the same as node positive. These results suggested as follows: 1) Lumpectomy with a clear margin and radiation is the best choice for small breast cancer (T < or = 3.0 cm, N0 or N1a). 2) Adjuvant therapy after surgical treatment is necessary for local recurrence.

Axilla↗
PubMed1996

[Clinical studies of inverted papilloma of the bladder].

Clinical studies were conducted on 9 cases of inverted papilloma of the urinary bladder which were transurethrally resected between August, 1987 and July, 1995 at our hospital, in males between 29 and 81 years of age (mean:58.3). Six of the 9 inverted papillomas were localized at the bladder neck and 3 in the trigone. Cystoscopic examinations revealed that inverted papillomas were divided into two types, one with a thick and short stalk with a smooth surface and the other with a thin and long stalk with/without a partial papillary surface. The majority of the former was located in the trigone and all of the latter cases in the bladder neck, suggesting that the two types occurred at different sites. Pathological examination by Hematoxylin-Eosin staining demonstrated that 5 of the 9 cases were of the trabecular type and 4 were of the grandlar type. Immunohistochemically, none of the tumors were stained with the antiprostatic-specific-antigen antibody revealed. Follow-up periods after the operation were from 12 to 48 months(mean:26.6 months) and no recurrence was observed.

Adult↗
PubMed1995

Tumorigenicity of EBNA2-transfected cells.

The Epstein-Barr virus nuclear antigen 2 (EBNA2) gene is thought to be important for transformation by Epstein-Barr virus (EBV), but the mechanism of this transformation is little understood. Here, to examine the transforming ability of EBNA2, we transfected a rat fibroblast cell line F2408 with a recombinant EBNA2 expression plasmid and examined cell morphology, colony formation in soft agar, and tumorigenicity in nude mice. The morphology of transfected clones was similar to those of untransfected cells, but two of seven clones grew in soft agar, and four clones of seven clones reproducibly formed tumors in nude mice. These four clones showed EBNA2 expression, but non-tumorigenic clones did not. These results indicate that the expression of EBNA2 is correlated with tumorigenicity.

Animals↗
PubMed1995

[Giant schwannoma in the pelvic cavity presenting as renal failure: a case report].

A case of giant schwannoma in the pelvic cavity detected with renal failure is reported. A 50-year-old man was referred to another clinic with chief complaints of general fatigue and edema of the face and dorsa of the feet. On March the 4th 1994, he was hospitalized in the clinic because of renal failure. Bilateral hydronephrosis and a giant pelvic tumor were found by computed tomography (CT) and ultrasonography. Because bilateral percutaneous nephrostomies failed to recover his renal function, he was referred to our clinic for the purpose of hemodialysis and the further examination of the tumor on March 16, 1994. The pelvic angiography showed that the tumor was fed by the vessel from the left internal iliac artery. After the chemo-embolization from the feeding artery, tumor resection was performed on May 9, 1994. The tumor was 16x13x10 cm in size, and 1,110 g in weight. The histological findings of the tumor revealed the mixed type schwannoma of Antoni A and B. Six months after the operation, he has had no tumor recurrence. This is a rare case of pelvic schwannoma which was detected with renal failure. We reviewed and discussed 56 cases of schwannoma in the pelvic cavity, including our case, in the Japanese literature.

Humans↗
PubMed1995

[Recurrence of transitional cell carcinoma in bilateral upper urinary tracts and ileal conduit with invasion in the abdominal wall around nephrostomy after total cystectomy: a case report].

A case of recurrence of transitional cell carcinoma in bilateral upper urinary tracts and ileal conduit with invasion in the abdominal wall around nephrostomy after total cystectomy is presented. A 33-year-old man with right nephrostomy, after total cystectomy, construction of ileal conduit, bilateral partial ureterectomy and left nephrectomy for transitional cell carcinoma at another hospital was referred to our hospital because of further recurrence in the right renal pelvis and ileal conduit. He had had left nephrostomy before the left nephrectomy was performed. Right nephrectomy and total extirpation of ileal conduit were performed and hemodialysis was started from the day after the operation. However, several weeks later, transitional cell carcinoma was detected pathologically in the left abdominal wall around the left nephrostomy which had been inserted. The renal pelvis was inferred to have leaked urine around the nephrostomy and invasion arose in this region. After radiation therapy he was discharged but he died from recurrence of carcinoma 9 months after the operation. After total cystectomy, examinations by percutaneous puncture of the renal pelvis are very effective for evidence of recurrence in the upper urinary tract. However, we emphasize that the percutaneous technique carries the risk of tumor invasion through the percutaneous urinary tract.

Abdominal Muscles↗
PubMed1995

[Intrascrotal fibrous pseudotumor accompanied by pelvic kidney with ectopic ureteral opening: a case report].

A case of intrascrotal fibrous pseudotumor accompanied by pelvic kidney with ectopic ureteral opening is reported. The patient was a 65-year-old man with the complaint of swelling of the right scrotal contents. Ultrasonography showed a heterogeneous mass with acoustic shadow from the right epididymis to right spermatic cord. Intravenous pyelography revealed a non-visualizing right kidney. Endoscopic examination was performed because of the right non-functioning kidney and right epididymectomy was performed. Endoscopic findings showed that the ureteral opening existed at 6 degrees of the bladder neck. Retrograde pyelography demonstrated the right kidney in the pelvic cavity. The tumor was stony hard and 30 x 50 mm in size. Pathological diagnosis of the tumor was a fibrous pseudotumor. We reviewed and discussed 22 cases of fibrous pseudotumor, including our case, in the Japanese literature.

Aged↗
PubMed1995

Expression of bone matrix protein messenger ribonucleic acids in human breast cancers. Possible involvement of osteopontin in development of calcifying foci.

BACKGROUND: Development of calcifying foci is a fairly common finding in human breast cancers, and the deposition of calcium phosphate is observed in such foci. The calcium phosphate is a physiologic component of bones and teeth. Since the expression of messenger (m) RNAs of osteopontin (OPN), osteocalcin (OC), osteonectin (ON), and matrix gla protein (MGP) has been described in bones and teeth, we examined the mRNA expression of OPN, OC, ON, or MGP in the calcifying foci that were observed in human breast cancers. EXPERIMENTAL DESIGN: Cell types expressing mRNAs of OPN, ON or MGP were identified with combination of in situ hybridization and immunohistochemistry. RESULTS: The OPN mRNA-expressing cells clustered around the necrotic foci within cancer cell nests, and the examination with anti-OPN antibody revealed that OPN protein was localized in such necrotic foci where calcium phosphate deposited. The OPN mRNA-expressing cells were identified as macrophages by staining the adjacent section with the anti-CD68 PG-M1 monoclonal antibody which specifically recognizes macrophages. Neither ON mRNA-expressing cells nor MGP mRNA-expressing cells appeared to correlate with the deposition of calcium phosphate. CONCLUSIONS: The OPN protein produced by macrophages appeared to play a significant role for development of calcifying foci within necrotic area of breast cancers.

Antibodies, Monoclonal↗
PubMed1994

Gadolinium-DTPA--enhanced magnetic resonance imaging of a sequestered lumbar intervertebral disc and its correlation with pathologic findings.

A 37-year-old man developed spinal nerve root compression caused by a sequestered lumbar intervertebral disc that migrated caudally away from the L5-S1 interspace of origin. Magnetic resonance imaging (MRI) scans of the lumbosacral spine after administration of gadolinium-DTPA (Gd-DTPA) revealed intense peripheral, but not entire, enhancement of an extradural defect. The result of examination using Gd-DTPA-enhanced MRI increased the certainty of preoperative diagnosis of sequestered disc. Pathologic examination of the resected specimen showed that the extradural defect was sequestered disc material covered with vascularized granulation tissue, and indicated that the intense peripheral enhancement of the extradural defect in Gd-DTPA-enhanced MRI was related to the accumulation of contrast material within the vascularized granulation tissue surrounding the avascular sequestered disc material.

Adult↗
PubMed1994

Experimental saccular aneurysms. II. A new model in swine.

A new technique for surgical construction of experimental lateral saccular aneurysms on the common carotid artery of swine is described. It involves end-to-side suturing of an isolated segment of vein to an artery. During a short period of parent artery clamping, an elliptical arteriotomy is fashioned through the open-ended vein graft, the open end of which is subsequently tied and clamps are removed to form an aneurysmal vein pouch. The principal advantage of this technique is the short period of vascular clamping necessary to isolate a segment of the parent artery. This prevents severe endothelial injury and prolonged postoperative vasospasm, both of which may promote intra-aneurysmal thrombosis. Narrow- or wide-necked aneurysms can be created. Steps in the surgical construction of this model are detailed, and specific advantages of using swine are highlighted.

Animals↗
PubMed1994

The effects of a carotid-jugular fistula on cerebral blood flow in the cat: an experimental study in the acute period.

The purpose of the present study is to investigate the effects of feline carotid-jugular (CJ) fistula (Spetzler's model) on cerebral blood flow (CBF) in the acute period after creation of the fistula. Using laser-Doppler flowmetry, cortical CBF was measured on the fistula side of 11 cats. Temporary occlusion and opening of the fistula led to an immediate increase and decrease, respectively, in cortical CBF. However, CBF returned to baseline within 1 minute, on average. CO2 reactivity in the closed fistula was preserved. It is suggested that cerebral hemodynamic changes due to Spetzler's CJ fistula model are minimal in the acute period after fistulization.

Acute Disease↗
PubMed1994

Mechanism of inhibitory effect of dextran sulfate and heparin on human T-cell lymphotropic virus type I (HTLV-I)-induced syncytium formation in vitro: role of cell-to-cell contact.

Cell-to-cell contact is usually essential for syncytium formation by HTLV-I-infected cell lines. The present study was undertaken to determine the inhibitory effect of polyanionic compounds, dextran sulfate and heparin, on HTLV-I-induced syncytium formation, as demonstrated by the fusion of HTLV-I-infected cells with target cells. These two compounds almost completely blocked syncytium formation in the early phase of the reaction at a concentration of 125 micrograms/ml, but dextran, as a control, did not inhibit it at concentrations up to 625 micrograms/ml. 50% inhibition of syncytium formation was detected at a concentration of 2 micrograms/ml of dextran sulfate 5000, 3 micrograms/ml of dextran sulfate 8000 and 8 micrograms/ml of heparin. The binding of radiolabeled HTLV-I-infected cells (HCT-1) to the target cells was inhibited by addition of dextran sulfate and heparin, and the inhibitory effects were concentration-dependent. No marked changes were detected in the expression of adhesion molecules on the virus-infected cells and target cells, and in the expression of envelope proteins on the virus-infected cells after exposing them to the polyanionic compounds. These results suggest that the blocking of cell-to-cell contact by polyanionic compounds, probably independent of surface adhesion molecules, is important for their inhibitory effect on HTLV-I-induced syncytium formation.

Antibodies, Monoclonal↗
PubMed1994

Draining vein pressure increases and hemorrhage in patients with arteriovenous malformation.

BACKGROUND: Recent radiological studies have shown that arteriovenous malformations with impaired venous drainage may be susceptible to hemorrhage. To evaluate this hypothesis using a hemodynamic approach, we measured intravascular pressure during surgery in three patients with arteriovenous malformation. SUMMARY OF REPORT: In three patients we measured intravascular pressures in the draining venous system and the feeding arteries simultaneously before removal of arteriovenous malformations with marked segmental stenotic or occlusive draining veins and evidence of hemorrhage. The draining vein pressures at prestenotic (or preocclusive) sites in the three patients were 38, 25, and 40 mm Hg, respectively, all significantly above the normal cortical venous pressure, whereas pressure measurements in poststenotic sites and the sagittal sinus pressure in the venous drainage system approached normal values. The feeding artery pressures in the patients were lower than normal cortical artery pressure because of the arteriovenous shunt. CONCLUSIONS: Intraoperative vascular pressure measurements support the hypothesis that arteriovenous malformations with impaired venous drainage may be associated with a local increase in venous pressure and thus may be susceptible to hemorrhage.

Adolescent↗
PubMed1994

Aneurysmography for visualizing large aneurysms.

We report a case of a large cavernous sinus aneurysm, in which conventional angiography did not clearly demonstrate the exact form and the position of the neck. Superselective angiography performed with the catheter tip in the lumen of the aneurysm and with the internal carotid artery occluded just proximal to its neck is a new technique that demonstrates the morphological details of an entire aneurysm. With the use of cineangiography, the exact volume of the aneurysm was defined. The valuable aneurysmographic information obtained was useful in achieving occlusion of the aneurysm, while preserving the parent artery.

Carotid Artery, Internal↗
PubMed1994

Venous ischemia caused by dural arteriovenous malformation. Case report.

A case is presented of tentorial dural arteriovenous malformation (AVM) associated with visual hallucinations and quadrant hemianopsia. Computerized tomography (CT) and magnetic resonance imaging showed an ischemic region, mainly affecting the white matter of the right occipital lobe, that was defined as an area of increased blood volume on dynamic CT scans and as a decrease in cerebral blood flow on N-isopropyl-p-123I-iodoamphetamine single-photon emission CT scans. Angiography demonstrated venous congestion, probably because the retrograde arterial inflow from the dural AVM into the corticomedullary vein was direct and not via the sinuses. The symptoms and radiological findings improved immediately after endovascular treatment. The origin of these symptoms was fully evaluated and confirmed to be a reversible ischemic change caused by disturbance of the volume of venous return over an extensive area.

Aged↗