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Biomedical subjects

A Kurata

Publications and source records attributed to A Kurata.

At least 19 recordsLinked to original sources
PubMed2002

Multiple arteriovenous malformations with hemorrhage.

BACKGROUND: A rare case of a left temporal arteriovenous malformation (AVM) with bleeding 10 days after removal of another hemorrhagic AVM in the frontal lobe is reported. METHOD: A 47-year-old man had an attack of headache and vomiting and was admitted to our hospital. On admission, a CT scan showed subcortical hemorrhage in the left frontal lobe. Left carotid angiography revealed four AVMs and a vertebro-basilar angiogram demonstrated a vascular malformation. FINDINGS: First, a hemorrhagic AVM was removed with a hematoma. Following the operation, left carotid angiograms continued to show, AVMs, particularly a temporal AVM with increased blood flow, and after 10 days this hemorrhaged. This was surgically resected and the remaining small AVMs were treated by stereotactic radiosurgery. INTERPRETATION: The patient had a high risk of hemorrhage. Adding hemodynamic stress to this situation, hemorrhage would have been expected to occur at an early time after the initial intervention for hemorrhagic AVM. Considering the risk of hemorrhage, other AVMs should undergo surgery as soon as possible after resection of hemorrhagic AVM.

Cerebral Angiography↗
PubMed2001

Protection of the spinal cord with pentobarbital and hypothermia.

BACKGROUND: Ischemic spinal cord damage during thoracic aortic operations has not been eliminated despite application of various adjuncts. We experimentally investigated the protective effects of pentobarbital and hypothermia on the spinal cord subjected to ischemia. METHODS: Among nine groups of 6 rabbits each, groups AI to AIII underwent 20-minute infrarenal aortic occlusion, and groups BI to BVI underwent 40-minute occlusion. Five milligrams per kilogram of pentobarbital was administered to groups AII and BII; 10 mg/kg in groups AIII, BIII, and BVI; 20 mg/kg in group BIV; and none in groups AI, BI, and BV. In groups BV and BVI, hypothermia was induced. Forty-eight hours postoperatively, the motor function of the lower limbs was evaluated. RESULTS: Statistically significant recovery of motor function was observed in animals in groups AII, AIII, BIII, BIV, BV, and BVI. CONCLUSIONS: Pentobarbital showed dose-dependent protective effects of the spinal cord. Moderate hypothermia alone also showed protective effects. Combined use of pentobarbital and hypothermia resulted in highly significant recovery of spinal cord function.

Animals↗
PubMed2001

Clinically unidentified dissection of vertebral artery as a cause of cerebellar infarction.

BACKGROUND AND PURPOSE: Dissection of vertebral arteries has been reported in association with minor neck movements without signs of trauma on the surface of the neck. In addition, injury of a vertebral artery can cause brain infarctions. However, few cases have been reported in which fatal brain infarction was due to nonocclusive, clinically undetected, traumatic thrombus formation in a vertebral artery. CASE DESCRIPTION: A 62-year-old man was hit by a car, and a right cerebellar infarction was found the day after the accident. The cause of the infarction could not be detected by angiography. Although the patient recovered favorably after surgical removal of the right lateral hemisphere of the cerebellum, he died suddenly 2 weeks after the accident. An autopsy and a microscopic study revealed pulmonary thromboembolism and organizing traumatic lesions of the right vertebral artery without occlusion or noteworthy stenosis of the artery. CONCLUSIONS: We concluded that the patient sustained traumatic lesions of the right vertebral artery during the traffic accident 2 weeks before death and that his cerebellar infarction was due to a thrombus resulting from these traumatic lesions.

Accidents, Traffic↗
PubMed2001

Two novel cucurbitacins, neocucurbitacins A and B, from the Brazilian folk medicine "Buchinha" (Luffa operculata) and their effect on PEBP2alphaA and OCIF gene expression in a human osteoblast-like Saos-2 cell line.

Two novel cucurbitacins designated as neocucurbitacins A (1), possessing inhibitory activity of polyoma enhancer binding protein 2alphaA (PEBP2alphaA) and osteoclastogenesis-inhibitory factor (OCIF) gene expression in human osteoblast-like cells, and B (2) were isolated from the fruit of Luffa operculata. Their structures have been determined by extensive spectroscopic investigation.

Cell Line↗
PubMed2001

Rupture of pial arteriovenous malformation associated with early thrombosis of the draining system following stereotactic radiosurgery--case report.

A 50-year-old man was treated with stereotactic gamma knife radiosurgery for an incidentally detected small callosal arteriovenous malformation (AVM) with stenosis of the main draining pathway. He suffered two episodes of intraventricular hemorrhage at 4 and 14 weeks after the radiosurgery. Radiological studies demonstrated that the anterior portion of the draining system including a varix, which had been irradiated, was thrombosed before the obliteration of arteriovenous shunts. Stereotactic radiosurgery is an accepted treatment for selected small and medium AVMs, but this procedure may increase the risk of bleeding. Early occlusion of a part of the draining pathway after stereotactic radiosurgery might have induced AVM rupture. An impaired venous outlet, either consisting of one draining vein or with stenosis, present before treatment may be develop thrombosis in response to high-dose irradiation.

Aneurysm, Ruptured↗
PubMed2001

Coil embolization for the treatment of ruptured dissecting vertebral aneurysms.

BACKGROUND AND PURPOSE: Proximal occlusion of the parent artery has been widely used for treatment of vertebral dissecting ruptured aneurysms, but this does not always completely prevent rerupture. We retrospectively studied 24 consecutive patients for clinical characteristics and/or for efficacy of occlusion with detachable coils at the site of dissection. METHODS: During a 45-month period, 24 of 242 patients with aneurysms associated with subarachnoid hemorrhage had dissecting vertebral aneurysms identified at angiography. Eighteen of the 24 patients were treated with platinum coil occlusion at the affected site as early as possible after diagnosis, two patients were treated conservatively, and four others were not eligible for treatment owing to intractable elevation of intracerebral pressure and severe brain stem dysfunction. RESULTS: The rate of aneurysmal rupture in the posterior fossa was high, at 56 (23%) of the 242 aneurysms, including 24 (10%) vertebral dissecting aneurysms. Subsequent rupture occurred in 14 (58%) of the patients, all within 24 hours after the first attack and three during transportation to the hospital. In all 18 patients, coil embolization at the affected site was successful, with no complications. Radiologic findings showed complete occlusion of the dissection site and patency of the unaffected artery (mean follow-up, 9 months). Among the six patients who did not undergo embolization, only one survived with a good outcome, the others died of repeat hemorrhage. CONCLUSION: A high rate of vertebral artery dissecting aneurysms may be expected in patients with subarachnoid hemorrhage, especially in those with early repeat hemorrhage. Detachable platinum coil embolization may be more effective than proximal occlusion for treatment of ruptured vertebral dissecting aneurysms because of immediate cessation of blood flow to the dissection site; however, in patients with bilateral dissections or hypoplastic contralateral vertebral arteries, prior bypass surgery orstent placement to preserve the artery will be needed.

Adult↗
PubMed2001

[An autopsy case of primary aortoduodenal fistula complicated by both gastric carcinoma and acute gastric mucosal lesions].

We present an autopsy case of aortoduodenal fistula complicated by both gastric carcinoma and acute gastric mucosal lesions(AGML). A 73-year-old man with a past history of gastric ulcer, myocardial infarction, and arteriosclerosis of the right femoral artery presented to Osaka National Hospital complaining of intermittent claudication of the right lower extremity. After a diagnosis of arteriosclerosis obliterans, percutaneous angioplasty was performed. The postoperative course was initially good. However, two weeks after the angioplasty procedure he suddenly vomited blood. Emergency endoscopy revealed both polypoid gastric carcinoma and AGML, which were considered to be the major cause of his gastrointestinal bleeding. And he died of uncontrollable gastrointestinal bleeding two weeks after this examination. Autopsy showed an atherosclerotic aneurysm of the abdominal aorta that had ruptured into the third part of the duodenum. To our knowledge, there has been no previous autopsy on a primary aortoduodenal fistula from an atherosclerotic abdominal aneurysm complicated by similar hemorrhagic gastric lesions. This case emphasizes the difficulty of making a clinical diagnosis of primary aortoduodenal fistula.

Acute Disease↗
PubMed2001

Bi-directional single anastomotic technique for the proximal anastomosis of free grafts (the saphenous vein or radial artery) to the ascending aorta in coronary artery bypass grafting surgery.

In an operation involving coronary bypass grafting, anastomoses to the ascending aorta with saphenous vein or radial artery grafts may increase the possibility of post-operative strokes by the dislodgement of embolic particles into the arterial vasculature. We report a bi-directional single anastomotic technique to decrease the possibility of intra and postoperative strokes and to allow earlier cardiac perfusion by the graft anastomosed to the ascending aorta, in case of CABG with 2 free grafts from there.

Anastomosis, Surgical↗
PubMed2000

Optimal management of the axilla in patients with breast cancer.

BACKGROUND: Although most surgeons perform some form of axillary lymph node dissection (ALND) as part of locoregional management of operable breast cancer, the extent of dissection remains controversial. PATIENTS AND METHODS: Observation of the axilla trial (protocol I) and partial dissection trial (protocol I) began in January 1996. Between January 1996 and May 2000, 45 post-menopausal and 207 women with clinically node-negative breast cancer were enrolled into protocol I and protocol II respectively. RESULTS: The 4-year cumulative incidence rate of axillary recurrence was 7% in patients with untreated the axilla. The 4-year overall survival rate was 98% in patients with untreated the axilla. The 4-year disease-free and overall survival rates were 96% and 98% respectively in patients treated with partial dissection. CONCLUSION: Total axillary dissection seems to be unnecessary in Japanese breast cancer patients with relatively small tumors.

Adult↗
PubMed2000

Minimally invasive coronary artery bypass grafting for the left anterior descending coronary artery.

OBJECTIVE: A single surgeon conducted One hundred and twelve patients underwent minimally invasive direct coronary artery bypass grafting for the left anterior descending coronary artery 112 patients at Yamato Seiwa Hospital from September 1996 until August 1999. METHODS: All procedures were performed via left anterior short thoracotomy using a stabilizer during graft anastomosis. RESULTS: No operative deaths occurred but 3 patients died while hospitalized due to noncardiac events. Graft occlusion was seen in 3 patients early postoperatively. Other angiography graft failure such as stenosis was seen in 11 patients. Occlusive lesions of other coronary arteries occurred in 77 patients (69%) and 53 patients underwent percutaneous transluminal coronary angioplasty the pre/postoperatively for those lesions. CONCLUSIONS: These results suggest that minimally invasive direct coronary artery bypass grafting is seen by cardiologists as a reasonable form of revascularization in conditioned patients having left anterior descending artery lesion, and that minimally invasive direct coronary artery bypass grafting has a spectrum of candidates different from that of conventional surgical revascularization for the coronary artery.

Adolescent↗
PubMed2000

Thromboangiitis obliterans: classic and new morphological features.

The clinical and pathological concept of thromboangiitis obliterans (TAO, Buerger's disease) is still controversial. While the clinical criteria of TAO are relatively well defined, the etiology is unknown and its diagnosis based on pathology is confusing, since there is no consensus on the precise pathological criteria for TAO. To investigate the morphological features that differentiate TAO from arteriosclerosis obliterans (ASO) or thromboembolism, and to clarify the morphological independence of TAO, we studied 94 amputated specimens of lower extremities, including 31 specimens from patients with a clinical diagnosis of TAO and 31 autopsy specimens as control cases. It was revealed that most of the classic morphological features described by Buerger and others are not helpful when considered independently in the differential diagnosis, except for intact internal elastic lamina. In addition, findings of intimal inflammation, intact media and absence of medial calcification were demonstrated to be common in both TAO and thromboembolism. Statistical analysis in the present study, the most comprehensive thus far, showed that novel findings of onion-like-shaped recanalizing vessels in the occluded arteries, adventitial fibrosis without medial fibrosis, swelling of the endothelium of the vasa vasorum and edema beneath the external elastic lamina were characteristic of TAO and would be helpful in a differential diagnosis. When a combination of these morphological features is present, diagnosis of a presumed overlap of TAO and ASO in the same site of the vessel concerned is possible. Furthermore, comparison of statistical evaluations based on morphological features performed in various diagnostic groups implies that the clinical diagnosis of TAO is currently underestimated because the results of the analysis of morphological features of specimens in which TAO was suspected or specimens selected on the basis of a broad and nonspecific definition of TAO were surprisingly similar to the results in strictly defined TAO cases. Our findings suggest that injury and regeneration of minute vessels such as recanalizing vessels and vasa vasorum play a part in the pathogenesis of TAO.

Adult↗
PubMed2000

The influence of vascular pressure and angiographic characteristics on haemorrhage from arteriovenous malformations.

BACKGROUND: The present study was designed to determine whether there is a physiological explanation for the predisposition of patients with certain angiographic characteristics to haemorrhage from cerebral arteriovenous malformations (AVMs). METHODS: Intra-operative measurement of feeding artery pressure (FAP) and intravascular pressures in the draining venous system [draining vein pressure (DVP) and cranial sinus pressure (SP)] were performed for 30 AVM cases using direct puncture of the vessels. The correlation between pressures and previously described angiographic characteristics predisposing to haemorrhage were evaluated. FINDINGS: Small nidus size and only one draining vein increased the risk of haemorrhage. FAP and DVP are both inversely related to the number of draining veins and the size of the AVMs. DVP was significantly higher in AVMs with haemorrhage (23.1+/-8.7 mmHg) than in those without (13.5+/-4.4), as was FAP (58.6+/-12.8 as opposed to 38.7+/-4. 7) (p<0.05). Moreover, the difference between systemic blood pressure and the FAP with haemorrhagic AVMs (17.0+/-9.5 mmHg) was significantly lower than that in nonhaemorrhagic cases (33.7+/-5.5) (p<0.05). The pressure difference between the feeding artery and draining vein was not significant between the haemorrhagic and nonhaemorrhagic groups. There was no significant difference of SP between haemorrhagic and nonhaemorrhagic patients. INTERPRETATION: The present study suggests that a high DVP probably induced by high resistance in the venous drainage system, as well as a high FAP, may contribute to the development of haemorrhage from AVMs, and physiologically supports previous reports that small AVMs and AVMs with only one draining vein are susceptible to haemorrhage.

Cerebral Angiography↗
PubMed2000

Purification, characterization, and relation to bikunin of rat urinary trypsin inhibitors.

Two forms of urinary trypsin inhibitor (UTI-1 and UTI-2) were purified from pooled urine of normal male rats to apparent homogeneity by salting out, affinity chromatography, gel filtration, and reverse-phase HPLC. UTIs-1 and 2 were shown to be thermostable glycoproteins with the respective molecular weights of 22,000 and 18,000 estimated by SDS-PAGE. These inhibitors combined with bovine trypsin in a 1:1 molar ratio: the Kd values were 2.5 x 10(-10) and 2.3 x 10(-10) M, respectively. Amino acid composition and sequence analysis indicated that UTI-1 corresponded to rat bikunin of which the amino acid sequence was deduced from a rat liver cDNA clone encoding alpha1-microglobulin [Lindqvist et al. (1992), Biochim. Biophys. Acta 1130, 63-67] except that the protein sequence seemed to lack C-terminal serine, and UTI-2 corresponded to UTI-1 lacking N-terminal 21 amino acid residues.

Amino Acid Sequence↗
PubMed2000

Ten years' experience of aortic aneurysm associated with systemic lupus erythematosus.

BACKGROUND: aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with systemic lupus erythematosus (SLE). The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in these patients. METHODS: among 429 patients operated on for abdominal aortic aneurysm (AAA) during the past 10 years, five cases with SLE were treated surgically. Their clinical data were reviewed, and the resected aneurysmal wall of the five patients was also examined histologically. RESULTS: the mean age of the patients with SLE was 55 years, which was statistically younger than that of the other patients (mean 77 years, s.d. 7.9, p <0.05). They had received long-term corticosteroid therapy for the treatment of SLE for a mean of 23 years. Histologically, destruction of the medial elastic lamina was characteristic. Four patients had no complications in the postoperative follow-up period (mean 4 years), while the remaining patient died of rupture of a dissecting aneurysm two years after operation. CONCLUSION: prolonged steroid therapy may play a major role in accelerating atherosclerosis, which can result in aortic aneurysmal enlargement, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with SLE.

Adrenal Cortex Hormones↗
PubMed2000

Dural arteriovenous malformations associated with cerebral aneurysms.

Only limited information is available concerning dural arteriovenous malformations (AVMs) found in association with cerebral aneurysms. The present report focuses on six such cases, concentrating attention on clinical characteristics and significance. Of a total of 46 dural AVMs encountered over a given period, six (13%) were linked with cerebral aneurysms. Particularly strong associations were noted for dural AVMs in the anterior cranial fossa (three of four cases) and convexity (all of three cases). With dural AVMs in the anterior cranial fossa, subarachnoid haemorrhage is common, so that where this is encountered the possibility of a complicating aneurysm should be considered in order to select an appropriate treatment.

Adolescent↗
PubMed2000

The effect of encephalo-myo-synangiosis on abnormal collateral vessels in childhood moyamoya disease.

Child patients with Moyamoya disease initially present with ischemic symptoms. However, the long-term risk of intracranial hemorrhage for childhood Moyamoya disease is unknown. Hemodynamic overload to the fragile collateral vessels has been considered to cause hemorrhage. We reviewed angiograms to evaluate the effect of encephalo-myo-synangiosis (EMS) on abnormally dilated collateral vessels in 13 child patients with Moyamoya disease. EMS was performed on 24 sides in 13 patients ranging from 5 to 14 years of age. Post-operative angiography (6-88 months after surgery) revealed good revascularizations through EMS (larger than one-third of the middle cerebral artery (MCA) distribution) in 18 sides (75%) and smaller revascularizations in 6 sides (25%). In cases with a good revascularization through EMS, reduction of the abnormal collateral vessels was observed not only in the basal Moyamoya vessels (94% of sides) but also in the medullary arteries derived from the choroidal arteries (62% of sides), which are considered to cause intraventricular hemorrhages in adult patients. It is suggested that EMS may reduce the hemodynamic load on dilated collateral vessels and, subsequently, the long-term risk of intracranial hemorrhage in childhood Moyamoya disease.

Adolescent↗
PubMed2000

Clinicopathological study of intracranial fusiform and dolichoectatic aneurysms : insight on the mechanism of growth.

BACKGROUND AND PURPOSE: Intracranial fusiform aneurysms can be divided into 2 clinically different subtypes: acute dissecting aneurysms and chronic fusiform or dolichoectatic aneurysms. Of these 2, the natural history and growth mechanism of chronic fusiform aneurysms remains unknown. METHODS: A consecutive series of 16 patients with chronic fusiform aneurysms was studied retrospectively to clarify patient clinical and neuroradiological features. Aneurysm tissues were obtained from 8 cases and were examined to identify histological features that could correspond to the radiological findings. RESULTS: Four histological features were found: (1) fragmentation of internal elastic lamina (IEL), (2) neoangiogenesis within the thickened intima, (3) intramural hemorrhage (IMH) and thrombus formation, and (4) repetitive intramural hemorrhages from the newly formed vessels within thrombus. IEL fragmentation was found in all cases, which suggests that this change may be one of the earliest processes of aneurysm formation. MRI or CT detected IMH, and marked contrast enhancement of the inside of the aneurysm wall (CEI) on MRI corresponded well with intimal thickening. Eight of 9 symptomatic cases but none of 7 asymptomatic cases presented with both radiological features. CONCLUSIONS: Data suggest that chronic fusiform aneurysms are progressive lesions that start with IEL fragmentation. Formation of IMH seems to be a critical event necessary for lesions to become symptomatic and progress, and this can be monitored on MRI. Knowledge of this possible mechanism of progression and corresponding MRI characteristics could help determine timing of surgical intervention.

Adult↗