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Y Okada

Publications and source records attributed to Y Okada.

At least 37 records · Page 2Linked to original sources
PubMed2005

In vivo demonstration of T lymphocyte migration and amelioration of ileitis in intestinal mucosa of SAMP1/Yit mice by the inhibition of MAdCAM-1.

The aetiology of Crohn's disease (CD) remains unknown. Since SAMP1/Yit mice have been reported to develop CD-like spontaneous enteric inflammation, such mice have been studied as an animal model of CD. In this study, using this model we examined T lymphocyte migration in microvessels of intestinal mucosa in vivo and the expression of adhesion molecules by immunohistochemistry. Fluorescence-labelled T lymphocytes isolated from AKR/J (control) mice were injected into the tail veins of recipient mice, and T lymphocyte migration in the postcapillary venules of Peyer's patches, submucosal microvessels, and villus capillaries of the terminal ileum was monitored using an intravital microscope. Adhesion of T lymphocytes was significantly increased in 35 week old SAMP1/Yit mice compared with that in AKR/J or 15 week old SAMP1/Yit mice. Immunohistochemical study showed increased infiltration of CD4, CD8 and beta7-integrin-positive cells and increased expression of MAdCAM-1 and VCAM-1 in the terminal ileum of SAMP1/Yit mice. Antibodies against MAdCAM-1 and VCAM-1 significantly inhibited adhesion of T lymphocytes to microvessels of the terminal ileum, and anti-MAdCAM-1 antibody showed stronger suppressive effect than the anti-VCAM-1 antibody. Periodical administration of anti-MAdCAM-1 antibody twice a week for 7 weeks significantly ameliorated ileitis of SAMP1/Yit mice, but submucosal hypertrophy was not significantly suppressed. Anti-VCAM-1 antibody treatment failed to show significant resolution of ileitis. In addition, anti-MAdCAM-1 antibody treatment also attenuated established ileitis. The results demonstrate that, although MAdCAM-1 and VCAM-1 play an important role in T lymphocyte-endothelial cell interactions in SAMP1/Yit mice, MAdCAM-1 may be a more appropriate target for therapeutic modulation of chronic ileitis.

Animals↗
PubMed2005

Aggrecanase analysis of synovial fluid of temporomandibular joint disorders.

OBJECTIVES: To determine whether or not aggrecanase in synovial fluid can be used as a biochemical marker in the diagnosis of temporomandibular joint disorder (TMJD). MATERIALS AND METHODS: Forty-four samples of synovial fluid were obtained from 35 patients with internal derangement or osteoarthritis and 15 control samples from 10 asymptomatic volunteers. Aggrecanase in the synovial fluid was examined by immunoblotting. RESULT: The incidence of aggrecanase expression in TMJD group were significantly higher than that in the normal control group (P < 0.05). Those with severe OA and anterior disc displacement without reduction showed significantly high expression of aggrecanase compared with other disease subgroups (P < 0.05). CONCLUSION: These findings suggested that aggrecanase could be a potential biochemical marker for cartilage degeneration in the TMJD.

Adolescent↗
PubMed2005

High-frequency signals (> 400 hz): a new window in electrophysiological analysis of the somatosensory system.

High-frequency signals (HFSs) between 400-1500 Hz in Magnetoencephalography (MEG) and Electroencephalography (EEG) provide a new window in electrophysiological analysis of the somatosensory system in humans and in other animals. The HFS in the primary somatosensory (SI) cortex precedes the conventional N20. In the swine model, they appear to be due to spiking in thalamocortical axonal terminals and in the soma and dendrites of cortical neurons. These spiking activities seem to activate slower conductances in the pyramidal cells in layers II-III and V, which give rise to N20. The HFS monitoring may be useful for separately evaluating the electrophysiology of the subcortical and cortical components of the somatosensory pathway.

Action Potentials↗
PubMed2005

Antioxidant activity of thiosulfinates derived from garlic.

Garlic extract significantly inhibited the oxidation of methyl linoleate in homogeneous acetonitrile solution, whereas the antioxidant effect of allicin-free garlic extract, prepared by removing allicin by prepared by removing allicin by preparative HPLC, was much lower than that of the garlic extract. These results suggest that the antioxidant properties are mostly attributed to the presence of allicin in the garlic extract. Allicin a major component of the thiosulfinates in garlic extract, was found to be effective for inhibiting methyl linoleate oxidation, but its efficiency was less than that of alpha-tocopherol. Next, the reactivity of allicin toward the peroxyl radical, which is a chain-propagating species, was investigated by direct ESR detection. The addition allicin to 2,2'-azobis(2,4-dimethylvaleronitrile)-peroxyl radical solution caused the signal intensity of the peroxyl radical to dose-dependently decrease, indicating that allicin is capable of scavenging the the peroxyl radical and acting as an antioxidant. Finally, we studied the structure-anioxidant activity relationship for thiosulfinates and suggested that the combination of the allyl group (-CH2CH=CH2) and the -S(O)S- group is necessary for the antioxidant action of thiosulfinates in the garlic extract. In addition, one of the two possible combinations, -S(O)S-CH2CH=CH2, was found to make a much larger contribution to the antioxidant activity of the thiosulfinates than the other, CH2=CH-CH2-S(O)S-.

Acetonitriles↗
PubMed2005

[Thoracoscopic surgery for elderly patients].

To clarify the feasibility of lung resections, especially those with video-assisted thoracoscopic surgery (VATS), for elderly patients with primary non-small cell lung cancer, 14 patients aged 80 to 83 years who had undergone surgical treatment at Tohoku University Hospital from 1997 to 2004 were retrospectively reviewed. Thirteen of 14 patients had clinical stage I lung cancer and VATS lobectomy was applied to 7 of 9 patients undergoing VATS. One hospital death with acute exacerbation of interstitial pneumonia was recorded in a patient undergoing standard thoracotomy because of severe pleural adhesion. Overall 5-year survival rates of these 13 patients were 63.3% and those with VATS lobectomy were 66.7%. We conclude that VATS lobectomy is a feasible therapeutic option to be offered to selected elderly patients with clinical stage I lung cancer.

Aged↗
PubMed2005

[Primary lung cancer incidentally diagnosed in lung biopsy for diffuse pulmonary disease].

UNLABELLED: We here presented 2 cases of interstitial pneumonia with lung adenocarcinoma incidentally diagnosed by partially resected lung for diffuse pulmonary disease. CASE 1: A 78-year-old female was admitted to the hospital complaining of productive cough and general fatigue. The chest computed tomography (CT) revealed diffuse honey comb pattern in bilateral lung field especially in the right lower lung. Video-assisted thoracoscopic lung biopsy was performed and was diagnosed as diffuse spreading well differentiated adenocarcinoma. CASE 2: A 59-year-old male was admitted to the hospital complaining of dyspnea and general fatigue. The chest X-ray revealed right pneumothorax and chest CT revealed diffuse honey comb pattern and bullae in bilateral lung field and fibrous tumor-like lesion in the right middle lung. Video-assisted thoracoscopic lung biopsy was performed and was diagnosed as pulmonary fibrosis with papillary adenocarcinoma. CONCLUSION: It is important to examine carefully the specimen obtained from thoracoscopic lung biopsy even if interstitial pneumonia is strongly suspected.

Adenocarcinoma↗
PubMed2005

[Lung cancer with polyarthropathy due to parvovirus B19: report of a case].

We reported a case of lung cancer with polyarthropathy induced by human parvovirus B19. A 60-year-old female with lung cancer was admitted to our hospital with polyarthropathy similar to rheumatoid arthritis. Although the abnormal accumulation of 99mTc-MDP in the bone scan film and rheumatoid factor positive were detected before operation, we diagnosed polyarthropathy induced by parvovirus B19 through the detection of parvovirus B19 IgM and B19 DNA. The joint pain gradually improved after surgical treatment for lung cancer.

Arthritis↗
PubMed2004

Auditory evoked magnetic fields to speech stimuli in newborns--effect of sleep stages.

The aim of the study was to examine whether a newborn can detect changes in a speech stimulus consisting of a fricative followed by a vowel /su/. In addition, we studied possible effect of the two sleep stages (active and quiet sleep) on the evoked magnetic responses. In young children (6 years), the same stimulus evokes a prominent deflection, consisting of two peaks. The first one (P1m) is evoked by the beginning of the fricative consonant and has a latency of about 145 ms. The second peak (P2m) with a latency of 340 ms, is evoked by the switch to the vowel. In newborns (n = 10), the waveform resembled that of the older children but latencies of the corresponding peaks were longer, 190 and 435 ms, correspondingly. The results suggest that already the newborn brain detects the change inside the auditory speech stimulus, namely the fricative sound changing into a vowel. However, the immaturity of the brain is reflected in the prolonged latencies. In addition, the responses were higher in amplitude in quiet sleep than in active sleep (F (1.9) = 36.5; p < 0.0002). This is in line with the enhanced somatosensory magnetic fields to tactile stimulation in quiet compared to active sleep in newborns.

Acoustic Stimulation↗
PubMed2004

Extravascular application of an intravascular ultrasound (IVUS) catheter during carotid endarterectomy to verify distal ends of stenotic lesions.

BACKGROUND: Intravascular ultrasound (IVUS) has been developed initially for intravascular imaging of coronary arteries to investigate vascular structures. We applied the IVUS catheter extravascularly to the cervical carotid arteries to obtain intra-operative ultrasound images during carotid endarterectomy (CEA). Intra-operative assessments of the distal ends of the stenotic lesions as well as pathological vascular structures are important, not only for exposing the lesions sufficiently but also for placing the shunt system safely. METHOD: An IVUS catheter (3.2 French/30 MHz) was intra-operatively applied close to the outer surface of the cervical carotid arteries during CEA. Ultrasound transection vascular images were obtained in 33 consecutive patients (30 males and 3 females) with a mean age of 66.5 years. FINDINGS: In 32 of 33 cases, extravascular application of IVUS catheter before making arteriotomies correctly depicted the distal ends of the internal carotid artery (ICA) stenotic lesions as a thin layer of vascular wall [0.64 +/- 0.16 mm (mean +/- SD) compared with 1.66 +/- 0.42 mm for carotid plaque] with intravascular blood flow. Based on the IVUS findings, we were able to adequately expose the normal ICA portion distal to the stenotic lesion before making the arteriotomy even in cases with stenotic lesions at very high positions, and to insert shunts safely. Furthermore, the properties of lesions and blood flow were also verified. However, it was difficult to examine the far vascular wall. CONCLUSIONS: Extravascular application of IVUS catheter is efficient for intra-operative evaluation of the distal end of the stenotic lesion especially in cases with stenotic lesions at very high positions and cases in whom pre-operative angiograms did not clearly demonstrate the distal end. The findings also demonstrate the properties of lesions and completeness of CEA.

Adult↗
PubMed2004

Nationwide survey of human Listeria monocytogenes infection in Japan.

Listeriosis, caused by Listeria monocytogenes, is a significant public-health concern as a result of its clinical severity and high mortality. Large foodborne outbreaks of listeriosis have occurred during the last two decades in Europe and the United States, but to date there have been no food-mediated epidemics of the disease and very little information is available on the number of cases of listeriosis in Japan. We performed a nationwide surveillance study of listeriosis. The data were collected between 1980 and 2002, and 95 case reports were identified from 1996 to 2002. We divided 13.6 (cases per year between 1996 and 2002) by the ratio of the number of beds in hospitals that replied to the questionnaire, to that of all the hospitals in Japan and estimated that there is an average of 83 cases of listeriosis per year and an incidence of 0.65 cases per million of the population in Japan.

Adolescent↗
PubMed2004

Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas.

BACKGROUND: To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed. METHODS: The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression. RESULTS: Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P = 0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only alpha integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P = 0.036), especially IPMTs (OR 35.7, P = 0.012). CONCLUSION: These results indicate that alpha-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.

Adenocarcinoma, Mucinous↗
PubMed2004

Mapping of SOMU1 and M1 epitopes on the apomucin encoded by the 5' end of the MUC5AC gene.

We have developed 11 monoclonal antibodies (MAbs) against human gastric mucin, (1-13M1, 2-11M1, 2-12M1, 9-13M1, 58M1, 19M1, 21M1, 45M1, 463M, 589M, 62M1), which specifically stained by immunohistochemisty both the human gastric surface mucosa and colon adenoma. Among them, five (19M1, 21M1, 463M, 589M, 62M1) immunoreacted with the peptide encoded by the 3' region of the MUC5AC gene (Nollet et al: Int J Cancer 2002;99:336-343). In this study, we identified in the 5' region of this gene the nucleotide fragments encoding peptides immunoreacting with three other anti-M1 MAbs (1-13M1, 2-11M1 and 9-13M1), as well as the SOMU1 MAb (Sotozono et al: J Immunol Methods 1996;192:187-196). 1-13M1 MAb immunoreacts with peptides, including the Cys 2 and Cys 4 domains. The SOMU1 MAb recognized the Cys 5 domain, and the MAbs 2-11M1 and 9-13M1 the globular D1/D2 and D3 domains, respectively. Using serial sections of the mucosae adjacent to colon adenocarcinomas and colon adenomas, we observed that the anti-M1 and anti-SOMU1 MAbs displayed the same immunostaining patterns. The three anti-M1 MAbs (2-12M1, 58M1, and 45M1) did not react with the products of the MUC5AC gene tested until now. The MUC5AC apomucin is now well characterized by MAbs immunoreacting against seven different epitopes belonging to the different main cystein globular domains of this macromolecule. Such antibodies are useful tools for studying the biosynthesis, polymerization, and degradation of mucin.

Animals↗
PubMed2004

Endotoxin stimulates monocyte-endothelial cell interactions in mouse intestinal Peyer's patches and villus mucosa.

Although monocyte-endothelial cell interactions represent an initial step in controlling the recruitment of monocytes in inflamed tissues, their dynamic processes in microvessels of lymphoid (Peyer's patches) and non-lymphoid (villus) regions in gut-associated lymphoid tissue remain poorly understood. We monitored the migration of fluorescence-labelled monocytes derived from the spleen in intestinal microvessels with or without lipopolysaccharide (LPS) treatment and investigated the role of adhesion molecules, P-selectin, vascular cell adhesion molecule (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). In control mice, there were few interactions between infused monocytes and the endothelium of intestinal microvessels. The monocyte-endothelial interactions (both rolling and adhesion) were significantly increased in intestinal microvessels of LPS-treated mice compared with those in controls. Anti-P-selectin monoclonal antibody (MoAb) significantly suppressed the LPS-induced increase in monocyte rolling in postcapillary venules of Peyer's patches and submucosal venules. Anti-VCAM-1 MoAbs significantly suppressed the LPS-induced increase in monocyte adhesion to postcapillary venules (PCVs) of Peyer's patches, submucosal venules, and villus capillaries. In contrast, anti-ICAM-1 MoAb significantly suppressed the number of adherent monocytes in PCV of Peyer's patches but not in submucosal venules or villus capillaries. These observations demonstrated that LPS treatment resulted in a significant increase in recruitment of monocytes both in microvessels of lymphoid and non-lymphoid regions and that P-selectin, VCAM-1 and ICAM-1 appeared to play important roles in LPS-induced interactions.

Animals↗
PubMed2004

Deposition of silicone oil droplets in the residual anterior lens capsule after vitrectomy and lensectomy in rabbits.

AIM: To examine the histology of preserved anterior lens capsule in vitrectomised and lensectomised rabbit eyes with and without silicone oil tamponade. METHODS: Forty adult Japanese albino rabbits received two port vitrectomy and lensectomy with or without silicone oil tamponade in one eye under both general and topical anaesthesia. Anterior lens capsule was preserved during operation. After healing intervals residual anterior capsule was histologically observed under light or electron microscopy. RESULTS: Immediately after operation, cuboidal lens epithelial cells were observed on the posterior surface of the preserved anterior capsule. During healing intervals in eyes with or without silicone oil tamponade, regenerated lens structure of Sommerring's ring and fibrous tissue formed in the peripheral and central areas of the residual capsule, respectively. Ultrastructural observation revealed the presence of many vacuoles amid matrix accumulation on the posterior capsular surface, suggesting the deposition of emulsified silicone oil droplets. CONCLUSION: Lens epithelial cells produce regenerated lenticular structure and fibrous tissue on the residual capsule following vitrectomy and lensectomy in rabbits. Silicone oil droplets formed by its emulsification deposit in extracellular matrix accumulated on the posterior surface of the anterior capsule. Emulsified silicone may potentially enhance opacification of residual anterior capsule following pars plana vitrectomy by silicone oil deposition and subsequent activation of lens epithelial cells.

Animals↗
PubMed2004

Immune signals in the context of secondary osteoporosis.

Bone homeostasis is maintained by a balance between bone resorption by osteoclasts and bone formation by osteoblasts, and alterations in bone metabolism can lead to diseases such as osteoporosis. Inter-cellular and intra-cellular signaling, originating from the immune system, the largest source of cell-derived regulatory signals, are involved in these processes. Immune-competent cells such as macrophages and lymphocytes deliver cell-cell signaling through soluble factors such as cytokines and through direct contact with the cells. Such immunological signals to the bone are transmitted primarily through osteoblasts or direct stimulation of osteoclasts to induce osteoclast maturation or bone resorption, which may in turn lead to the disequilibrium of bone metabolism. Inflammatory diseases such as rheumatoid arthritis are good examples of such a process, in which immunological signals play a central role in the pathogenesis of the accompanying secondary osteoporosis. We will achieve a better understanding of the pathogenesis of bone metabolism in osteoporosis through immune signaling, and thereby develop improved therapeutic strategies for these conditions.

Animals↗
PubMed2004

Multiple regional 1H-MR spectroscopy in multiple system atrophy: NAA/Cr reduction in pontine base as a valuable diagnostic marker.

OBJECTIVE: We performed (1)H-MR spectroscopy ((1)H-MRS) on multiple brain regions to determine the metabolite pattern and diagnostic utility of (1)H-MRS in multiple system atrophy (MSA). METHODS: Examining single voxels at 3.0 T, we studied metabolic findings of the putamen, pontine base, and cerebral white matter in 24 MSA patients (predominant cerebellar ataxia (MSA-C), n = 13), parkinsonism (MSA-P), n = 11), in 11 age and duration matched Parkinson's disease patients (PD) and in 18 age matched control subjects. RESULTS: The N-acetylaspartate to creatine ratio (NAA/Cr) in MSA patients showed a significant reduction in the pontine base (p<0.0001) and putamen (p = 0.02) compared with controls. NAA/Cr in cerebral white matter also tended to decline in long standing cases. NAA/Cr reduction in the pontine base was prominent in both MSA-P (p<0.0001) and MSA-C (p<0.0001), and putaminal NAA/Cr reduction was significant in MSA-P (p = 0.009). It was also significant in patients who were in an early phase of their disease, and in those who showed no ataxic symptoms or parkinsonism, or did not show any MRI abnormality of the "hot cross bun" sign or hyperintense putaminal rims. NAA/Cr in MSA-P patients was significantly reduced in the pontine base (p = 0.001) and putamen (p = 0.002) compared with PD patients. The combined (1)H-MRS in the putamen and pontine base served to distinguish patients with MSA-P from PD more clearly. CONCLUSIONS: (1)H-MRS showed widespread neuronal and axonal involvement in MSA. The NAA/Cr reduction in the pontine base proved highly informative in the early diagnosis of MSA prior to MRI changes and even before any clinical manifestation of symptoms.

Aspartic Acid↗
PubMed2004

[New surgical technique of pulmonary segmentectomy by ultrasonic scalpel and absorbable sealing materials].

We developed new surgical technique of pulmonary segmentectomy by ultrasonic scalpel to sever intersegmental pulmonary tissue and absorbable sealing materials to cover the cut surface of lung. This method is expected to preserve more anatomical lung volume than the segmentectomy with surgical stapler. Two cases of post surgical recurrent lung cancer, 3 cases of pulmonary metastasis and 4 cases of primary lung cancer were applied this technique to preserve function. Among 3 materials examined, best result was obtained with polyglycolic acid felt (PGAF:Neoveil). PGAF is a very soft and thin (0.15 mm depth) new absorbable material that is able to closely adhere to irregular sections of the lung with fibrin glue and effectively seals air leakage. Mean chest drainage period after surgery in 6 cases with PGAF was 3.3 days. Excellent lung expansion was obtained immediately after the surgery and PGAF was disappeared completely on chest CT within 1 year. Although the possible superiority of this method is suggested in the present study, further comparative study is necessary to clarify the advantage of this new technique.

Absorbable Implants↗