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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 235 records · Page 13Linked to original sources

A case of pelvic arteriovenous malformation in a male.

BACKGROUND: Congenital pelvic arteriovenous malformation (AVM) is rare especially in males. We present a case of pelvic AVM in a 38-year-old male. He was admitted to our hospital with left flank abdominal pain and painless gross hematuria. METHODS/DISCUSSION: Pelvic computed tomography demonstrated a homogeneous contrast-enhanced mass, 6 cm in diameter. For diagnosis, non-invasive magnetic resonance imaging (MRI) and color Doppler ultrasonography were very useful in our case. Though the treatment is controversial, we decided to monitor his clinical course.

Abdominal Pain↗

Cellular artificial skin substitute produced by short period simultaneous culture of fibroblasts and keratinocytes.

We developed a novel artificial skin substitute consisting of two collagen sponge layers with different pore sizes and cross-link densities. Fibroblasts suspended in 0.5 ml Dulbecco-modified Eagle's medium (DMEM) + 10% fetal bovine serum (FBS) were seeded on the lower dermal sponge layer, then epidermal collagen sponge and 0.1 ml suspension of keratinocytes in KGM were layered in this order. After a few hours, the medium was changed to DMEM + 5% FBS. These processes were carried out in one day, and the composite layers were then cultured by the air-liquid interface culture method. Three to five days after seeding, keratinocytes had grown to about ten layers, and fibroblasts had grown three-dimensionally into the lower dermal sponge layer. This novel cellular artificial skin substitute was grafted onto nude mice and took in 4 weeks. This skin substitute has the advantage of a shorter culturing period than previously cultured skins, and may be clinically useful for grafting that is urgently required in patients with severe generalised burns.

Animals↗

Functional MR imaging with venography for neurosurgical identification of the central sulcus.

We evaluated the applicability of functional MR imaging overlaid onto brain images superimposed venography for neurosurgical identification of the central sulcus. In 20 volunteers and 12 patients with brain tumors located around the sensorimotor cortex, gradient echo and large flip angle functional MR image was performed to allow visualization of flow effect and susceptibility related changes in relative large vein by motor hand task. Functional MR image acquired was overlaid on 3D anatomical image with 3D venography. Based on the 3D mapping, intra-operative cortical somatosensory evoked potentials (SEPs) were recorded. The significant activation area obtained from functional MR imaging was projected on an ascending cortical vein in 16 volunteers (80%) and 10 patients (83%). Comparing the anatomical activation map with visual inspection of the exposed cortical surface made it easy to identify the activation area during surgery. The cortical veins in 9 of 10 were validated as a central vein by intra-operative cortical recording of SEPs. Combination of functional MR imaging overlaid onto 3D anatomical image with venography and intra-operative SEPs permitted rapid and accurate localization of the central sulcus during surgery.

Adult↗

The characterization of human brain tumor using magnetization transfer technique in magnetic resonance imaging.

The clinical applicability of magnetization transfer (MT) technique in magnetic resonance imaging (MRI) for the estimation of the histological and constitutional feature of brain tumors was investigated. MT effect was evaluated by measuring the MT ratio (MTR). The parameters in 1.5-tesla MRI system were as follows: TR, 50 msec; TE, 5 msec; flip angle, 30 degree; offset frequency of off-resonance MT pulse, 1000 Hz. The sequence was performed in 20 normal volunteers and 45 patients with brain tumors which were characterized histologically and surgically. The MTR for brain tumors was significantly lower than that for normal brain tissue (p < 0.05). The MTR for meningioma was higher than that for the other brain tumors (p < 0.05). In the meningiomas, MTR for fibrous type was higher than that for meningothelial type, but there was no statistical significance. Regarding the physical consistency for the brain tumors, as classified by surgery, there was a statistically significant difference in MTR between the soft tumor group (0.22 +/- 0.03, n = 6) and the hard tumor group (0.36 +/- 0.04, n = 10) (p < 0.01). This study suggested that the MT technique for patients with brain tumor may be useful to understand the characteristics of the tumors presurgically, based on the degree of intermolecular interaction of macromolecule such as protein.

Adenoma↗

Analysis of phospholipase C gene in patients with subarachnoid hemorrhage due to ruptured intracranial saccular aneurysm.

This study is designed to determine whether patients with aneurysmal subarachnoid hemorrhage have mutations in the phospholipase C-delta 1 (PLC-delta 1) gene, which was identified as a gene responsible for hypertension in spontaneously hypertensive rats. Seventy-two cases (31 male and 41 female) with intracranial saccular aneurysms were analyzed. The mean age was 60.1 +/- 11.5 years (mean +/- SD) (range 24-85 years). There were 35 patients (48.6%) with hypertension, 5 (6.9%) with diabetes mellitus, 12 (16.7%) with hyperlipidemia, 8 (11.1%) with ischemic heart disease, and 25 (34.7%) who were active smokers. The location of aneurysm was distributed as follows: 33 (33%) were at anterior cerebral artery, 23 (23%) were at middle cerebral artery, 28 (28%) were at internal carotid artery, and 16 (16%) were at vertebro-basilar artery. Six patients (8.3%) had a family history of intracranial aneurysms. There were 20 patients (27.8%) with multiple aneurysms, and 8 patients (11.1%) with a large or giant aneurysm. The four regions of PLC-delta 1 gene (bases 1099-1271, 1254-1401, 1343-1481, and 1882-2023) where genetic mutations were found in spontaneously hypertensive rats, were screened by PCR-SSCP analysis and their nucleotide sequences of all patients were determined. However, no mutations were detected in all patients. These results suggest that mutations of PLC-delta 1 gene previously implicated in hypertensive factor in rats may not be the case with human patients and therefore may be poorly related with aneurysmal subarachnoid hemorrhage.

Adult↗

Intra-operative optical method using intrinsic signals for localization of sensorimotor area in patients with brain tumor.

The purpose of this study is intra-operatively to localize the sensorimotor area by intrinsic optical method detecting the changes in regional cerebral blood flow (rCBF) and cortical temperature following neuronal activity during median nerve stimulation. In 18 patients with brain tumors located around the sensorimotor cortex, cortical recording of somatosensory evoked potentials (SEPs) was performed and localized changes in rCBF during median nerve stimulation were measured by a laser-Doppler flowmeter on the locations of SEPs and around the activation area obtained by functional magnetic resonance imaging (fMRI). In two patients, cortical thermomapping was also performed during median nerve stimulation. In fMRI study, the significant activation area of sensorimotor could be obtained in 17 of 18 patients. In cortical recording of SEPs, the polarity reversal of N20 and P20 was observed in 14 of the 18 patients. In 9 of the 14 patients in whom SEPs could be recorded, the localized changes in rCBF, corresponding to the stimulation, were detected in the N20 area. In 2 of the 4 patients in whom N20 could not be recorded successfully, the localized changes in rCBF could be detected. The increase in rCBF during the stimulation was 18.3% +/- 5.3% (mean +/- SD, n = 11). Thermomapping could demonstrate the localized area, where the increase in rCBF was also detected, by observation of the changes in cortical temperature during the stimulation. The intra-operative intrinsic optical method detecting rCBF and cortical temperature in combination with recording of SEPs may be considered useful for brain functional localization related to neurosurgical disorders.

Aged↗

Tumor response and patterns of failure following intraoperative radiotherapy for unresectable pancreatic cancer--evaluation by computed tomography.

Tumor response and patterns of failure following intraoperative radiotherapy (IORT) of 42 patients with unresectable pancreatic cancers were evaluated by computed tomography (CT). At the time of maximum tumor regression, the tumor response rate following IORT was 52%, with three tumors showing CR. The median time of maximum tumor regression was 3 months after IORT. When tumor response was evaluated within 2 months of IORT, no significant difference in survival rate between responders and non-responders was noted. However, when tumor response was evaluated 3-6 months after IORT, the responders showed a significantly better survival rate than the non-responders. Local tumor recurrence, liver metastasis, and peritoneal dissemination were major causes of failure after IORT for unresectable pancreatic cancers. In addition, the median time of detection of these findings by CT was 2-3 months after IORT. Thus, our results indicate that CT performed 3-4 months after IORT is most important for predicting clinical outcome.

Adenocarcinoma↗

Facial nerve repair using a collagen conduit in cats.

We evaluated facial nerve regeneration using a collagen tube as a nerve conduit in five cats. In three 5 mm of the facial nerve were resected, a collagen tube was implanted, and a 5 mm segment of the opposite facial nerve was resected, reversed 180 degrees, and sutured back as an autologous nerve graft. In one a collagen tube was implanted on one side, and in the remaining one a 5 mm nerve segment was reversed. Histological, electrophysiological, and horseradish peroxidase labelling examinations were carried out 4-24 weeks postoperatively. Histological study showed that the nerve was well vascularised and regenerated. Electrophysiological examination confirmed the recovery of evoked electromyograms through to the regenerated axons. Horseradish peroxidase examination also confirmed restoration of the whole facial nerve. The collagen tube is an efficient nerve conduit.

Animals↗

HLA-DPB1*0501-associated opticospinal multiple sclerosis: clinical, neuroimaging and immunogenetic studies.

In order to clarify the relationship between the clinical phenotype and the human leucocyte antigen (HLA) in multiple sclerosis in Asians, 93 Japanese patients with clinically definite multiple sclerosis underwent clinical MRI and HLA-DPB1 gene typing studies. According to a neurological examination, 29 patients were classified as opticospinal multiple sclerosis, 17 as spinal multiple sclerosis and 47 as Western type multiple sclerosis showing the involvement of multiple sites in the CNS including either the cerebrum, cerebellum or brainstem. The opticospinal multiple sclerosis showed a significantly higher age of onset, higher expanded disability status scale scores and higher CSF cell counts and protein content than the Western type multiple sclerosis. On brain and spinal cord MRI, the opticospinal multiple sclerosis showed a significantly lower number of brain lesions, but a higher frequency of gadolinium-enhancement of the optic nerve and a higher frequency of spinal cord atrophy than in Western type multiple sclerosis. The frequency of the HLA-DPB1*0501 allele was found to be significantly greater in opticospinal multiple sclerosis (93%) than in healthy controls (63%, corrected P value = 0.0091 and relative risk = 7.9), but not in Western type multiple sclerosis (66%) or spinal multiple sclerosis (82%). The marked differences in the clinical and MRI findings as well as in the immunogenetic backgrounds between the opticospinal multiple sclerosis and Western-type multiple sclerosis together suggest that HLA-DPB1*0501-associated opticospinal multiple sclerosis is a distinct subtype of multiple sclerosis.

Adult↗

Aminoguanidine supplementation delays the onset of senescence in vitro in dermal fibroblast-like cells from senescence-accelerated mice.

The effects of aminoguanidine supplementation on senescence acceleration in vitro were examined in fibroblasts from the dorsal dermis of newborn SAMP11 (accelerated senescence-prone mice), and were compared to the effects in cell lines from SAMR1 (accelerated senescence-resistant) mice. Four millimolar aminoguanidine supplementation significantly delayed the senescence/crisis in cell lines from SAMP11 mice, but did not affect the senescence/crisis in cell lines from SAMR1 mice. Flow cytometric analysis of the DNA content of confluent cells revealed that aminoguanidine supplementation significantly decelerated the increase in the number of tetraploid cells until senescence/crisis. Although mean concentrations of lipid peroxides in the primary cultures did not differ significantly, considerably higher lipid peroxidation was observed in some SAMP11 cultures, and aminoguanidine supplementation reduced them to the levels in SAMRI cultures. These results strongly suggest that oxidative stress derived from polyamine catabolism may contribute to the senescence acceleration in vitro in cell lines from SAMP11 mice.

Animals↗

Formation of 4-hydroxy-2-nonenal-modified proteins and 3-nitro-L-tyrosine in rat island skin flaps during and after ischemia.

4-Hydroxy-2-nonenal (HNE)-modified proteins and 3-nitro-L-tyrosine were evaluated as a specific marker of reactive oxygen species (ROS)- and nitric oxide (NO)-mediated peroxynitrite-induced tissue injuries in ischemic and reperfused skin flap by Western blot analysis. Specimens were taken from island skin flaps of rats during the following three conditions: ischemia only, 5 hours of ischemia and reperfusion, and 10 hours of ischemia and reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine increased with ischemic time (3, 6, and 10 hours postischemia). In the reperfused skin flap after both 5 and 10 hours of ischemia, HNE-modified proteins and 3-nitro-L-tyrosine were increased 3 hours postreperfusion, and they reached a maximum 6 hours after reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine 1 hour postreperfusion were higher with 10 hours ischemia-reperfusion than with 5 hours ischemia-reperfusion. These results indicate (1) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity in ischemic flaps is dependent on the ischemic period and (2) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity occurs during an early stage of reperfusion if the ischemic period is long.

Aldehydes↗

Skin flap storage with intracellular and extracellular solutions containing trehalose.

To evaluate and compare the effects of IT-Kyoto (IT-K) solution (intracellular type) and ET-Kyoto (ET-K) solution (extracellular type) on long-term skin flap preservation (from 24-120 hours), Japanese white rabbits were used as an animal model and Euro-Collins (EC) solution was used as a comparative solution. A total of 180 animals were divided randomly into 15 groups (N = 12) for 24, 48, 72, 96, and 120 hours of flap storage in three solutions. The survival rate, weight change, and histological appearance of flaps were compared among the three solutions. The survival rates in the IT-K and ET-K solutions were the same: 100%, 100%, 100%, 92%, and 50% in flaps preserved for 24, 48, 72, 96, and 120 hours, which were higher (p < 0.01 in the 72-, 96-, and 120-hour groups) than those in the EC solution group: 100%, 75%, 33%, 8.3%, and 0%. The flap weight gain in the IT-K and ET-K solution groups was less than that in EC solution group (p < 0.01). Histologically, flaps in the IT-K and ET-K solution groups showed a better appearance than those in the EC solution group. It was concluded that in a rabbit model IT-K and ET-K solutions are superior to EC solution for long-term skin flap preservation, and the safe preservation period for IT-K and ET-K solutions is approximately 96 hours. It was also concluded that the effects of intracellular (IT-K)-type solution and extracellular (ET-K)-type solution on rabbit skin flap preservation are similar.

Animals↗

Application of artificial dermis prior to full-thickness skin grafting for resurfacing the nose.

Two patients with nasal skin defects resulting from excision of rhinophyma and multiple angiofibromas were treated with artificial dermis followed by full-thickness skin grafts taken from the postauricular region. The secondary skin grafts took completely in both patients, and the postoperative results were excellent. Although a two-stage operation is required, application of artificial dermis prior to full-thickness skin grafting is a reliable method for resurfacing the nose.

Adult↗

Eustachian tube cartilage and medial movement of lateral pharyngeal wall on phonation.

Several authors have demonstrated the importance of medial movement of the lateral pharyngeal wall in velopharyngeal closure upon phonation. However, it remains controversial what muscle is responsible for lateral pharyngeal wall movement and where is the main site of this movement. The purpose of this study was to address the above two unanswered questions. In 22 subjects (12 normal volunteers, 10 patients with cleft palate), lateral pharyngeal wall movement upon phonation was evaluated by using rapid magnetic resonance imaging (MRI). Before rapid MRI, their lateral pharyngeal wall movements were classified into three groups: the poor, moderate, and good, according to the findings of nasopharyngoscopy. Inward displacement of the eustachian tube cartilages upon phonation, which was quantified as distance ratio in the transverse plane of MR images, was compared with nasopharyngoscopic findings. In addition, the level of lateral pharyngeal wall movement was observed in the plane 5 mm lateral to the mid-sagittal plane of MR images. Inward displacement of the eustachian tube cartilage in the transverse plane of MR images was coincident with medial movement of lateral pharyngeal wall observed by nasopharyngoscopy in all 22 subjects. By using one-way analysis of variance, a statistically significant correlation was found between nasopharyngoscopic classification and distance ratio. The sagittal plane of MR images revealed that the main site of movement occurred at the level of the hard palate and above. It is concluded that medial movement of the lateral pharyngeal wall consists of inward displacement of the eustachian tube cartilage, which is caused by contraction of the levator veli palatini muscle, and that the primary site of this movement is at the level of the hard palate and above, where the eustachian tube, but not the superior constrictor muscle, exists.

Adolescent↗

Rubrimonas cliftonensis gen. nov., sp. nov., an aerobic bacteriochlorophyll-containing bacterium isolated from a saline lake.

Phenotypic and phylogenetic studies were performed with two strains (OCh 317T and OCh 318; T = type strain) of aerobic chemoheterotrophic bacteriochlorophyll-containing bacteria isolated from water of a saline lake located on the west coast of Australia. Both strains were Gram-negative, short rods and were motile by means of polar flagella. Catalase, oxidase, nitrate reductase, phosphatase and urease were produced. The cells utilized D-glucose, citrate, glycolate, pyruvate and ethanol. Acids were produced from L-arabinose, D-fructose, D-galactose, D-glucose, D-ribose and D-xylose. The strains could grow in media containing 0.5-7.5% NaCl. Bacteriochlorophyll a was synthesized under aerobic conditions. The results of 16S rRNA gene sequence comparisons revealed that strain OCh 317T represented a new lineage in the alpha-3 group of the class Proteobacteria. Strains OCh 317T and OCh 318 were identified as strains of the same species because of their very similar phenotypic characteristics and their previously described high DNA-DNA homology. Therefore, it was concluded that the two strains should be assigned to a new genus and species, for which the name Rubrimonas cliftonensis is proposed. The type strain is OCh 317T (= JCM 10189T).

Bacteria, Aerobic↗

Roseivivax halodurans gen. nov., sp. nov. and Roseivivax halotolerans sp. nov., aerobic bacteriochlorophyll-containing bacteria isolated from a saline lake.

Phenotypic and phylogenetic studies were performed with two strains (OCh 239T and OCh 210T, T = type strain) of aerobic bacteriochlorophyll-containing bacteria isolated from the charophytes and the epiphytes on the stromatolites, respectively, of a saline lake located on the west coast of Australia. Both strains were chemoheterotrophic, Gram-negative and motile rods with subpolar flagella. Catalase and oxidase were produced. ONPG reaction was positive. Cells utilized D-glucose, acetate, butyrate, citrate, DL-lactate, DL-malate, pyruvate, succinate, L-aspartate and L-glutamate. Acids were produced from D-fructose and D-glucose. Bacteriochlorophyll a was synthesized under aerobic conditions. Strain OCh 239T had nitrate reductase and phosphatase. Acids were produced from L-arabinose, D-galactose, lactose, maltose, D-ribose and sucrose. The strain could grow in 0-20.0% (w/v) NaCl. Strain OCh 210T had urease. Hydrolysis of gelatin was positive. Acids were produced from D-xylose. The strain could grow in 0.5-20.0% (w/v) NaCl. The results of 16S rRNA sequence comparisons revealed that strains OCh 239T and OCh 210T formed a new cluster within the alpha-3 group of the alpha subclass of the class Proteobacteria. The similarity value of the 16S rRNA sequences between strains OCh 239T and OCh 210T was 95.8%. Therefore, it was concluded that these two strains should be placed in a new genus, Roseivivax gen. nov., as the new species Roseivivax halodurans sp. nov. and Roseivivax halotolerans sp. nov. The type species of the genus is Roseivivax halodurans. The type strains of Roseivivax halodurans and Roseivivax halotolerans are OCh 239T (= JCM 10272T) and OCh 210T (= JCM 10271T), respectively.

Bacteria, Aerobic↗