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Akihiro Sawada

Publications and source records attributed to Akihiro Sawada.

16 recordsLinked to original sources
PubMed2006

Percutaneous mesenteric stenting followed by laparoscopic exploration for visceral malperfusion in acute type B aortic dissection.

A 55-year-old man underwent percutaneous mesenteric and left renal stenting for malperfusion in acute type B aortic dissection. Laparoscopic exploration was performed immediately after percutaneous revascularization to ensure the integrity of the abdominal viscera. Because the diagnosis of mesenteric infarction may sometimes be difficult and its delay can be fatal, we advocate laparoscopic exploration as a mini-invasive method after percutaneous management of visceral malperfusion, if the integrity of the abdominal viscera needs to be verified.

Aortic Dissection↗
PubMed2006

Genome wide expression analysis of white blood cells and liver of pre-diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats using a cDNA microarray.

In a prior study, we reported on a significant decrease in calpain10 gene expression in white blood cells (WBC) as well as the major insulin-target tissues including liver and adipose tissue, before the onset of diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. In this study, we extended our hypothesis that some type 2 diabetes mellitus (NIDDM) susceptible genes are up/down-regulated before the onset in WBC of OLETF rats, reflecting their up/down-regulation in major insulin-target tissues, such as the liver. We tested this hypothesis using rat cDNA microarrays. The findings show that 1080 genes are up/down-regulated by more than 2-fold compared to the controls, Long-Evans Tokushima Otsuka rats, before the onset in WBC and liver under fasted or insulin administered condition. Fifty-seven of the 1080 genes were up/down-regulated in both WBC and the liver. More than half have been reported to NIDDM susceptible genes and the remainder have not been reported to be related to NIDDM. These results indicate that there some NIDDM related genes are up/down-regulated in WBC before the onset of diabetes.

Animals↗
PubMed2005

Ipsilateral mamillary body atrophy after infarction of the posterior cerebral artery territory: MR imaging.

We describe herein magnetic resonance (MR) features of ipsilateral mamillary body atrophy after infarction of the posterior cerebral artery (PCA) territory. During the period May 2000 through July 2004, 13 patients with infarction of the PCA territory underwent cranial MR imaging in the chronic stage. Two 1.5-T scanners were used to obtain axial T1- and T2-weighted images with conventional spin-echo and fast spin-echo pulse sequences, respectively. The slice thickness was 6 mm, with a 2-mm interslice gap. Five of the 13 patients with PCA territory infarction had ipsilateral mamillary body atrophy. However, this asymmetry of the mamillary bodies was unclear in two of the five patients because of the thickness of the axial image slices. All five patients had a temporo-parieto-occipital infarction. The remaining eight patients had a parieto-occipital or an occipital infarction. Unilateral transneuronal mamillary body degeneration after infarction of the ipsilateral PCA territory including the posteromedial temporal lobe can be detected on conventional thick axial MR images.

Aged↗
PubMed2005

On-line microdevice for stress proteomics.

The handling of the cells or tissues is essential for proteomics research or drug screening, where labor is not avoidable. The steps of cell wash, protein extraction, protein denaturing are complicated procedures in conventional method using centrifugation and pipetting in the laboratory. This is the bottle-neck for proteome research. To solve these problems, we propose to utilize the nanotechnology, which will improve the proteomics methodology. Utilizing the nanotechnology, we developed a novel microseparation system, where centrifugation and pipetting are needless. This system has a nanostructured microdevice, by which the cell handling, protein extraction, and antibody assay can be performed. Since cell transfer is needless, all cells are corrected without any loss during the cell-pretreatment procedures, which allowed high reproducibility and enabled the detection of low amount of protein expression. Utilizing the microdevice, we analyzed the stress induced proteins. We further succeeded the screening of food that was useful for immunity and found that an extraction from seaweed promoted the apoptosis of T-lymphoblastic cells. Here, we present an on-line microdevice for stress proteomics.

Nanotechnology↗
PubMed2005

MR-guided percutaneous cryoablation for bilateral multiple renal cell carcinomas.

A 35-year-old woman with five renal cell carcinomas (RCCs) was treated by percutaneous cryoablation. She had two RCCs in the left kidney and three in the right. Cryoablation was performed using a high-pressure argon-based system with 2- or 3-mm cryoprobes under magnetic resonance (MR) guidance. Three tumors were completely ablated. Two tumors were residual, as they were so close to nearby organs that we were forced to stop the freezing to avoid complications. No complications were encountered, and renal function was preserved. In conclusion, MR-guided cryoablation is a safe procedure even when RCCs are bilateral and multiple.

Adult↗
PubMed2004

Symmetrical lesions of the middle cerebellar peduncle: MR imaging and differential diagnosis.

The purpose of this paper is to show several diseases that manifest symmetrical hyperintense lesions on the middle cerebellar peduncles, the largest connecting peduncles between the brainstem and the cerebellum, in conventional magnetic resonance (MR) images. We retrospectively reviewed cranial MR images obtained with 0.3-, 0.5-, 1.0-, and 1.5-Tesla scanners. We found symmetrical middle cerebellar peduncular lesions in patients with Wilson's disease; hepatic encephalopathy; extrapontine myelinolysis; acute disseminated encephalomyelitis; wallerian degeneration of the pontocerebellar tracts after either pontine infarction, pontine hemorrhage, or central pontine myelinolysis; leukodystrophy; olivopontocerebellar atrophy; and toluene abuse. Definitive diagnosis of these diseases can be made relatively easily on the basis of clinical data; however, examination of associated brainstem or supratentorial lesions in MR images is also important.

Adolescent↗
PubMed2004

Gyral abnormalities in the early stage of superior sagittal sinus thrombosis.

We report computed tomography (CT) features in a case of segmental thrombosis of the superior sagittal sinus. On the initial cranial CT scan, both frontal cortices showed focal areas of slightly increased attenuation. The lesions were isointense on magnetic resonance (MR) images no matter what pulse sequence was used, except on fluid-attenuated inversion recovery images, which showed curvilinear sulcal hyperintensity. On postcontrast T1-weighted images, curvilinearly enhancing structures were apparent in both frontal cortical sulci. No lesion appeared on follow-up CT or in MR images. We speculated that the areas of slightly increased attenuation in the cortices represented blood congestion in the cortical veins, venules and capillaries without serum leakage. Cranial CT images should be carefully interpreted to avoid overlooking subtle lesions.

Aged↗
PubMed2002

Suitability of four polymorphic DNA markers for indirect genetic diagnosis of haemophilia A in Japanese subject.

Indirect genetic diagnosis using polymorphic DNA markers can detect carriers of haemophilia A (HA). These markers include CA repeat polymorphisms at intron 13 (CA-13) and CT-AG at intron 22 of the coagulation factor VIII (FVIII) gene, and also certain restriction fragment length polymorphisms (RFLPs) such as HindIII at intron 19 and BclI at intron 18. Recently, CA repeat polymorphism at intron 6 (CA-6) was also reported. We compared usefulness of the BclI RFLP, the HindIII RFLP, and CA-13 to that of CA-6. Heterozygosity of markers was examined in 282 X chromosomes obtained from 205 subjects including HA patients. Expected heterozygosity of the HindIII and BclI RFLPs was 30.0% and 27.9%, while observed heterozygosity was 28.0% and 26.5%. Expected heterozygosity of CA-13 was 45.6%, and observed heterozygosity was 40.0%. CA-6 showed two alleles with repeat numbers of 13 and 14, expected and observed heterozygosity were low (1.4% and 2.6%, respectively). When we used these markers in a HA lineage where the mother was a carrier according to coagulation factor assays, carrier diagnosis was possible using CA-13, the HindIII RFLP, and the BclI RFLP. This was not true for CA-6, for which the mother was homozygous. Although CA-13, and the HindIII and BclI RFLPs were useful for indirect genetic diagnosis of HA, CA-6 proved less useful because of low heterozygosity.

DNA↗
PubMedDate not supplied

Magnetic resonance-guided percutaneous cryoablation of uterine fibroids: early clinical experiences.

PURPOSE: Uterine fibroids (leiomyomas) are the most common tumors of the uterus. The present study evaluated the feasibility and effectiveness of magnetic resonance (MR)-guided percutaneous cryoablation for uterine fibroids as a minimally invasive treatment alternative. METHODS: From August 2001 to June 2002, MR-guided percutaneous cryoablation was performed on seven uterine fibroids in 6 patients who displayed clinical symptoms related to tumors. Using a horizontal-type open MR system, cryoablation probes were percutaneously placed in fibroids. Fibroids were ablated, and the site and size of ice balls were monitored on MR imaging. Postoperatively, patients completed a questionnaire to assess changes in presenting clinical symptoms, and MR images were obtained for all patients at follow-up. Changes in clinical symptoms and tumor volume were evaluated in each patient. RESULTS: All treated patients showed reductions in tumor size. Mean volume reduction rate was 40.3% at 6 weeks postoperatively, and 79.4% at 9-12 months. All patients reported fever after treatment. Surgical drainage was required for abscess in the probe channel in one patient, and transient liver damage occurred in another. Subjective symptoms improved in all patients except one who had multiple tumors, and no patient complained of new symptoms after cryoablation during follow-up. CONCLUSION: MR-guided percutaneous cryoablation represents a feasible and effective treatment for uterine fibroids.

Adult↗
PubMedDate not supplied

Carotid-anterior cerebral artery anastomosis: MR angiographic features and literature review.

Carotid-anterior cerebral artery anastomosis is a rare anomaly of the anterior part of the circle of Willis. We report here magnetic resonance (MR) angiographic findings in 2 patients with this anomaly. MR angiographic source images are useful in evaluating the anatomical details of this anomaly. Including the 2 present cases, 27 patients with this anomaly have been reported in the English-language literature. Thirty anomalous arteries were found in the 27 patients (R/L/bilateral=22/2/3). The reason for the right-sided predominance is unknown.

Adult↗
PubMedDate not supplied

Variations of the superior cerebellar artery: MR angiographic demonstration.

PURPOSE: The purpose of this study was to describe variations of the proximal segments of the superior cerebellar artery (SCA) detected by magnetic resonance (MR) angiography. MATERIALS AND METHODS: We reviewed 145 consecutive MR angiograms. All patients were studied with a 1.5-Tesla imager using the three-dimensional time-of-flight technique. RESULTS: There were 16 duplicated SCAs in 13 patients, seven SCAs originating from the posterior cerebral arteries in six patients, four early bifurcations of the SCAs in four patients, and one SCA arising from the internal carotid artery. Because the SCA is small in caliber, the bilateral SCAs in nine patients could not be identified on MR angiograms owing to patient movement. In two patients with duplicated SCA, one of the duplicated trunks compressed the trigeminal nerve at the root entry zone, resulting in trigeminal neuralgia. CONCLUSION: Although most of these SCA variations have no clinical significance, preoperative identification of SCA variations is important for avoiding complications during surgery and/or for interventional procedures of the distal basilar artery.

Adolescent↗
PubMedDate not supplied

Wallerian degeneration of the middle cerebellar peduncle after pontine infarction: MR imaging.

PURPOSE: To report magnetic resonance (MR) imaging findings of wallerian degeneration of the pontocerebellar tract secondary to a pontine infarction. MATERIALS AND METHODS: We retrospectively reviewed cranial MR images obtained during the past seven years in our institution and selected those from patients with a chronic stage of pontine infarction and a hyperintense lesion at the central portion of the middle cerebellar peduncle on T2-weighted images. RESULTS: In three patients with a ventromedial pontine infarction, we found a symmetrical hyperintense lesion at the central portion of the middle cerebellar peduncle bilaterally on T2-weighted MR images in the chronic stage. In another patient with a ventrolateral pontine infarction, we found such a lesion at the ipsilateral middle cerebellar peduncle. CONCLUSION: Because the middle cerebellar peduncle carries afferent fibers from the contralateral basis pontis to the cerebellar cortex, these middle cerebellar peduncular lesions are regarded as wallerian degeneration. This secondary degeneration should not be misinterpreted as a newly developed infarction or other disease.

Aged↗
PubMedDate not supplied

Bilateral anterior cerebral artery territory infarction associated with unilateral hypoplasia of the A1 segment: report of two cases.

We report two cases of bilateral anterior cerebral artery (ACA) territory infarction. On magnetic resonance (MR) angiograms, the A1 segment of the ACA was unilaterally hypoplastic in both cases, suggesting that unilateral hypoplasia of A1 is a significant predisposing factor for this rare type of cerebral infarction. When the contralateral A1 is dominant, embolic materials may enter into it more easily.

Aged↗