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Biomedical subjects

Y Miyasaka

Publications and source records attributed to Y Miyasaka.

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

Analysis of differentially expressed genes in human hepatocellular carcinoma using suppression subtractive hybridization.

The genetic basis of hepatocellular carcinoma (HCC) has not yet been fully understood. Although various methods have been developed to detect differentially expressed genes in malignant diseases, efficient analysis from clinical specimens is generally difficult to perform due to the requirement of a large amount of samples. In the present study, we analysed differentially expressed genes with a small amount of human HCC samples using suppression subtractive hybridization (SSH). Total RNA were obtained from the hepatitis C virus-associated HCC and adjacent non-HCC liver tissues. cDNA was synthesized using modified RT-PCR, and then tester cDNA was ligated with 2 different kinds of adaptors and hybridized with an excess amount of driver cDNA. Tester specific cDNA was obtained by suppression PCR and the final PCR product was subcloned and sequenced. We identified 7 known genes (focal adhesion kinase, deleted in colon cancer, guanine binding inhibitory protein alpha, glutamine synthetase, ornithine aminotransferase, M130, and pepsinogen C) and 2 previously unknown genes as being overexpressed in HCC, and 1 gene (decorin) as suppressed in HCC. Quantitative analysis of gene expression using quantitative RT-PCR demonstrated the differential expression of these genes in the original and other HCC samples. These findings demonstrated that it is possible to identify the previously unknown, differential gene expression from a small amount of clinical samples. Information about such alterations in gene expression could be useful for elucidating the genetic events in HCC pathogenesis, developing the new diagnostic markers, or determining novel therapeutic targets.

Amino Acid Sequence↗
PubMed2001

Prevalence and mortality of the Brugada-type electrocardiogram in one city in Japan.

OBJECTIVES: We sought to study the prevalence and mortality of subjects exhibiting the Brugada-type electrocardiogram (ECG) in a community-based population in Japan. BACKGROUND: The Brugada syndrome has been associated with sudden death in subjects without structural heart disease. Hospital-based studies showed 11% to 38% annual fatal arrhythmic events in patients with the Brugada syndrome. METHODS: Prevalence and mortality of the Brugada-type ECG were studied in subjects who had ECGs during a health examination in Moriguchi, Osaka, Japan. Information about death and relocation from Moriguchi city was obtained prospectively. RESULTS: The Brugada-type ECG was found in 98 of 13,929 study subjects (0.70%, 95% confidence interval [CI]: 0.57% to 0.86%). The typical coved-type with an rsR' pattern in V(1) lead ("typical" Brugada-type) was found in 0.12% of subjects (95% CI: 0.07% to 0.20%). The prevalence for male subjects with the Brugada-type ECG (81%) was significantly higher than it was for those without (26%, p < 0.0001). In male subjects, the Brugada-type ECG was found in 2.14% (95% CI: 1.70% to 2.66%), and the "typical" Brugada-type was found in 0.38% (95% CI: 0.21% to 0.64%). After 2.6 +/- 0.3 years of follow-up, there was 1 death (1.0%, 95% CI: 0.03% to 5.6%) of a subject with the Brugada-type ECG, whereas there were 139 deaths (1.0%, 95% CI: 0.85% to 1.2%) of those without the Brugada-type ECG (p = 0.9943, log-rank test). CONCLUSIONS: A substantial number of the Brugada-type ECG were observed in subjects in a community-based population in Japan, especially in men. The total mortality of subjects with the Brugada-type ECG did not differ from the mortality of those without the Brugada-type ECG in a community-based population.

Aged↗
PubMed2001

Radiation therapy in combination with transcatheter arterial chemoembolization for hepatocellular carcinoma with extensive portal vein involvement.

AIM: The aim of this study was to examine the effectiveness and toxicity of radiation therapy in combination with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with extensive portal vein tumor thrombus (PVTT). METHODS: The combined therapy was performed in 24 HCC patients with extensive PVTT. External radiation targeted for PVTT (50 Gy in 2 Gy fractions) was performed in combination with repetitive TACE for intralobar lesions using 30-60 mg epirubicin every 3 months, and associations of the following variables with the survival rate were evaluated: gender, age, viral etiology, Child's class, performance status, extrahepatic metastasis, size and number of HCC, and location of PVTT. RESULTS: The local response confined to PVTT was complete response (CR) in four patients, partial response (PR) in eight patients, no change (NC) in eight patients, and progressive disease (PD) in four patients. By using the stepwise Cox's regression analysis, only Child's class was associated with the survival rate. The survival rates after 1 and 2 years were 73 and 21% in Child's A, 10 and 0% in Child B or C, and 61 and 21% in patients in whom the local response was CR or PR, and 19 and 9% in those in whom the local response was NC or PD, respectively. By using the multiple logistic regression analysis, Child's class was the only factor associated with the local response (P = 0.006). CONCLUSIONS: The combined therapy is feasible and may be useful to reverse PVTT in patients with good hepatic function reserve.

Antineoplastic Agents↗
PubMed2001

Overexpression of interferon gamma-inducible protein 10 in the liver of patients with type I autoimmune hepatitis identified by suppression subtractive hybridization.

OBJECTIVE: To clarify gene expression profiles in the liver may elucidate the pathogenesis of type I autoimmune hepatitis (AIH). Using suppression subtractive hybridization (SSH), we identified genes overexpressed in the liver of AIH. METHODS: A small liver biopsy sample from a patient with definite AIH was available to be analyzed in our system. By mixing cDNA synthesized from this sample as a 'tester' and cDNA from a normal liver as a 'driver,' we subtracted cDNA to enrich genes overexpressed in AIH. After polymerase chain reaction (PCR) amplification and subcloning, we identified subtracted genes by sequencing 50 randomly selected clones. RESULTS: Only one cDNA fragment, which is identical to interferon inducible protein 10 (IP-10), was overexpressed by > 10 times in the liver of AIH, as compared with control. We confirmed IP-10 overexpression in all eight patients with AIH by reverse transcription PCR. Immunohistochemical analysis demonstrated increased IP-10 expression in hepatocytes in the liver of AIH. Reverse transcription PCR analysis of 63 liver biopsy samples with various liver diseases revealed that IP-10 expression was significantly higher in AIH (p = 0.025) and chronic hepatitis C (p = 0.0043) than in other liver diseases. Interestingly, the amount of IP-10 mRNA expression was correlated with serum ALT values in AIH (p = 0.0006), but not in chronic hepatitis C (p = 0.43). CONCLUSION: These results indicate the IP-10 expression in the liver might be used as a preferential marker of AIH, and that IP-10 has some pathophysiological roles in the liver damage of AIH.

Alanine Transaminase↗
PubMed2001

Sequences in the NS5A protein of hepatitis C virus and the serum alanine aminotransferase response to interferon therapy in Japanese patients.

BACKGROUND AND AIMS: Chronic hepatitis C is a slowly progressive disease and eventually causes hepatocellular carcinoma in many patients. Although interferon (IFN) therapy has been used for viral eradication, its success rate is only about 30%. In patients in whom it has failed (non-responders), there are several patterns of serum alanine aminotransferase (ALT) values, and detection of serum HCV-RNA during and after IFN therapy and improved long term prognosis were reported in patients whose serum ALT values were normalised by IFN therapy even if HCV viraemia persisted. The present study sought to clarify the virological characteristics contributing to these differences. METHODS: Complete or partial length dominant sequences of hepatitis C virus genotype 1b (HCV-1b) were determined by direct sequencing. Firstly, the complete sequences of HCV-1b genomes were determined in six non-responders; three showed normalisation of serum ALT values during IFN-alpha therapy and the other three did not. Subsequently, the amino acid residues that were different in the two groups were further analysed retrospectively in another 82 patients. RESULTS: Comparison of the sequences suggested an association between amino acids 2154-2172 of HCV-1b and serum ALT normalisation. A retrospective analysis of 82 patients revealed that the number of amino acid substitutions in this region was the only statistically significant variable associated with ALT normalisation (odds ratio 31.0; 95% confidence interval 5.0-286) in multivariate analyses. CONCLUSIONS: A HCV genomic region that correlates with the ALT response to IFN therapy appears to be present in virologically IFN ineffective patients.

Adult↗
PubMed2001

Lower mortality in patients with the DD genotype of the angiotensin-converting enzyme gene after acute myocardial infarction.

OBJECTIVE: The angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with different serum ACE concentrations and cardiac ACE activity. We assessed whether the ACE gene I/D polymorphism influenced cardiac mortality in Japanese patients with acute myocardial infarction. METHODS AND RESULTS: The ACE gene I/D polymorphism was determined in 441 consecutive patients with a first myocardial infarction. There were 69 patients (16%) with the DD genotype, 194 patients (44%) with the ID genotype, and 178 patients (40%) with the II genotype. During a mean follow-up of 9.4 months, there were 49 cardiac deaths (DD, n = 4; ID, n = 26; II, n = 19). The DD genotype was significantly associated with a lower mortality than the other genotypes (p = 0.0363) by Cox regression analysis adjusted for age, sex, site of myocardial infarction, Killip functional class, reperfusion therapy during acute phase, ACE inhibitor use, and beta-blocker use. CONCLUSIONS: In a selected cohort of Japanese patients, the DD genotype was associated with a significantly lower cardiac mortality after a first myocardial infarction.

Female↗
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

[A case report of hemiparesis due to compression of the medulla oblongata by an elongated vertebral artery].

The authors report a case of a 53-year-old woman who developed symptoms and signs of compression of the left medulla oblongata by the elongated and curved left vertebral artery with normal diameter. Twelve days before admission to the hospital, the patient suddenly noticed severe occipital-nuchal headache and nausea with vomiting, while she was unloading a burden. Neurological examination revealed left facial hyperalgesia, right hemihypesthesia and mild right hemiparesis. Hoarseness was observed, but the movement of the uvula and tongue was normal. Hypertension was noticed (180/100). Cerebral and vertebral angiography revealed no aneurysm, but demonstrated an elongated and curved V4 portion of the left vertebral artery with normal diameter. Coronal plain of T2 weighted image of MRI and CT scan with metrizamide administered into the CSF, clearly demonstrated an elongated and curved left vertebral artery compressing the ventro-lateral portion of the left medulla oblongata, neurovascular decompression of the V4 from the medulla oblongata was performed. Through the operating microscope, it was observed that the elongated and curved V4 portion of the left vertebral artery with normal configuration was compressing the left medulla oblongata ventro-laterally, making a compression notch at the outlets of the cranial nerves IX and X. Transposition of the V4 portion was impossible. Some pieces of Taflon felt, thick enough to prevent the pulsatile movement of the V4 from compressing the medulla oblongata, were inserted between the V4 and the medulla oblongata. Two months after the operation, the patient's right hemiparesis and sensory disturbances were gradually improving and her blood pressure had become normal. The authors emphasize that, among patients with symptoms and signs of compression of the medulla oblongata, there is at least one patient for whom neurovascular decompression was an effective treatment.

Female↗
PubMed2000

Mild mitral regurgitation was associated with increased prevalence of thromboembolic events in patients with nonrheumatic atrial fibrillation.

Although several studies demonstrated that the presence of significant mitral regurgitation was associated with reduced occurrence of thromboembolism, little data is available concerning the effect of mild mitral regurgitation on the occurrence of thromboembolic events. To evaluate the association between mild mitral regurgitation and thromboembolic events, we reviewed 232 patients' records between January 1996 and September 1997 who had nonrheumatic atrial fibrillation. There were 59 patients (25%) with mitral regurgitation > or = grade 2, 69 patients (30%) with grade 1 mitral regurgitation, and 104 patients (45%) with no mitral regurgitation. Patients with grade 1 mitral regurgitation had significantly higher prevalence of thromboembolic events (28%) than those with mitral regurgitation > or = grade 2 (8%, P=0.006) or those with no mitral regurgitation (11%, P=0.007). A history of previous thromboembolic events were compared between 173 patients with grade 1 mitral regurgitation and those with no mitral regurgitation using the logistic regression analysis adjusted for age, sex, administration of warfarin, and presence of hypertension, diabetes mellitus, structural heart disease, enlarged left atrium (> or = 40 mm), chronic atrial fibrillation, and grade 1 mitral regurgitation. Grade 1 mitral regurgitation (odds ratio=2.689, 95% confidence interval=1.039-7.189, P=0.0434) and no warfarin administration (odds ratio=0.045, 95% confidence interval=0.002-0.242, P=0.0036) were significantly associated with the history of thromboembolic events. The presence of mild mitral regurgitation in nonrheumatic atrial fibrillation was associated with higher prevalence of thromboembolic events.

Aged↗
PubMed2000

Characteristics of hepatitis C viral genome associated with disease progression.

The clinical presentations of chronic hepatitis C are not uniform. Some patients show persistently high serum alanine transaminase (ALT) values and develop liver cirrhosis and hepatocellular carcinoma (HCC), whereas serum ALT values stay normal in other patients. The mechanism causing this diversity remains to be elucidated. The aim of this study was to identify genomic characteristics of hepatitis C virus (HCV) genotype 1b associated with disease progression. Full length sequences of HCV were determined in 14 patients who showed persistently normal serum ALT values (normal ALT group) and 13 cirrhotics with HCC (HCC group). Residues in which amino acid usage was different between these 2 groups were extracted, and Progression score was defined as the total number of residues with 7 amino acids, more frequently present in the HCC group than in the normal ALT group. In the validation of this Progression score in 9 patients with normal ALT and 25 with HCC, the score was significantly higher in the HCC group (3.1 +/- 1.1 vs. 2.0 +/- 0.9, P =.019). Finally, the correlation between the score and clinical markers related to disease progression was analyzed. In a total of 107 patients with chronic HCV infection, the Progression score was correlated significantly with platelet counts (r = -0.31, P =.0024) by multivariate analysis. In conclusion, high Progression scores were associated with the presence of HCC and low platelet counts. Sequences of the HCV-1b genome may be related to the progression of chronic hepatitis C.

Amino Acids↗
PubMed2000

Basaloid-squamous carcinoma of the esophagus: report of a case.

We report herein the case of a 69-year-old man with basaloid-squamous carcinoma (BSC) of the esophagus. To the best of our knowledge, this is the 60th case of BSC of the esophagus to be reported in Japan, and a review of the other 59 cases is presented after this case report. In our patient, endoscopic findings revealed a circumferential erosion in the middle intrathoracic esophagus (Im), and a protruding tumor with friable ulceration in the center of the erosion. A biopsy suggested that it was moderately differentiated squamous cell carcinoma (SCC), and a thoracoscopic total thoracic esophagectomy was performed. Histologically, the protruding-type lesion with ulceration was composed of BSC, and the circumferential 0 -I + IIc type lesion was composed of moderately differentiated SCC. The immunohistochemical findings of these resected specimens led us to suspect that the basal-layer-type SCC had transformed into BSC by undergoing differentiation and expansive proliferation.

Aged↗
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

Vascular structure of arteriovenous malformations.

Cerebral arteriovenous malformations (AVMs) are classified angiographically into two types: the arteriovenous fistula (AVF) type and the plexiform type. However, the differences in vascular structure of these two types have not been clarified. The purpose of the present study is to elucidate the vascular structure of plexiform AVMs and to discuss the clinical significance of this classification of AVMs. Specimens of AVMs resected in 8 cases and identified by cerebral angiography as plexiform AVMs were examined. Immediately after their removal, microdissection of the terminal arterial feeder, the nidus, and the venous drainer was performed under a microscope. A histological examination of each element was then conducted. Microdissection of a portion of the vascular mass that formed the nidus made it possible to separate individual vessels of the mass from each other. Many of these individual vessels connected with the feeder on one side, while the other side anastomosed with the drainer, thus exhibiting the morphology of an AVF. From our examination of the AVMs in the present study, we inferred that the plexiform type is fundamentally a conglomeration of AVFs. It is therefore suggested that the vascular structure of this type of AVM is not fundamentally different from that of the AVF type.

Adult↗
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↗