[Treatment of ocular diseases with high dose of T.T.F.D. (thiamine tetrahydrofurfuryl disulfide)].
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Eye Diseases↗
Biomedical subjects
S Hamada
Publications and source records attributed to S Hamada.
A system for computer-assisted design of stent-grafts for aortic aneurysms using 3-D morphological models.
A three-dimensional model was constructed from helical CT images for abdominal aortic aneurysm (AAA) and thoracic aortic aneurysm (TAA). A stent-graft was designed and positioned endoluminally on the computer. One hundred and nine stent-grafts for 101 patients were designed by this method and deployed well in all patients. The design time was reduced from 4 to 0.5 hr.
Adult↗
Amplitude abnormalities in the scalp far-field N18 of SSEPs to median nerve stimulation in patients with midbrain-pontine lesion.
Various amplitude ratios were measured in 20 normal controls and 36 patients with midbrain-pontine, thalamic or putaminal lesions in order to evaluate the amplitude abnormalities in scalp far-field N18 following median nerve stimulation. A study of normal controls showed that the distributions of P9/N18, P14/N18 and N18/P14 + N18 resembled a gaussian distribution and could be used as criteria for determining the decrease in N18 amplitude in each patient. There was a decrease in N18 amplitude, or the absence of N18, in patients with midbrain-pontine lesions, but not in those with thalamic or putaminal lesions. Nine amplitude ratios (P11/P9, P14/P9, N18/P9, P9/P11, P9/P14, P9/N18, N18/P14, P14/N18 and N18/P14 + N18) were compared statistically for normal controls and 3 groups of patients based on non-parametric, Wilcoxon's non-pairs and signed-rank tests. A decrease in N18 amplitude in midbrain-pontine lesion was shown by significant changes in N18/P9, P9/N18, N18/P14, P14/N18 and N18/P14 + N18, no amplitude decreases in P11 and P14 being found from the amplitude ratios of P11/P9, P9/P11, P14/P9 and P9/P14. No significant changes were seen in any of the 9 amplitude ratios when the normal controls and patients with thalamic and putaminal lesions were compared. The amplitude ratios of N18 can be used to detect a decrease in N18 amplitude in patients with midbrain-pontine lesions. The data obtained support the hypothesis that N18 originates in the midbrain-pontine region and that neither the thalamus nor thalamocortical radiation make major contributions to the formation of the N18 peak.
Adult↗
Assignment of tremulous body mutant gene zitter (zi) to linkage group IV of the rat (Rattus norvegicus).
Zitter rats are mutants from a Sprague-Dawley rat colony. They exhibit whole body tremors, defective overhairs, bent whiskers, and spongiform encephalopathy of the central nervous system. The anomalies are caused by an autosomal recessive gene, zitter (zi). We examined the linkage relationships between zi and 14 polymorphic loci in two backcross series, (zitter x TM)F1 x zitter and (zitter x BN)F1 x zitter. Linkage of the zi locus to Hao-1 and Svp-1 indicated that the zi locus belongs to linkage group IV. The gene order was zi--(9.2% +/- 2.8%)--Hao-1--(27.7% +/- 6.5%)--Svp-1.
Animals↗
A pitfall in ultrafast CT scanning for the detection of left atrial thrombi.
We studied 41 patients with mitral stenosis by ultrafast CT (UFCT) and transesophageal echocardiography to detect left atrial thrombi. Cardiac UFCT was performed twice after contrast medium injection to obtain early (during injection lasting 40-60 s) and late (approximately 5 min after beginning injection) phase images. There were 10 patients (24%) in whom a filling defect detected in the early phase disappeared in the late phase. The site of filling defects was the left atrial appendage in nine patients and the left atrium in one patient. All of the filling defects were in the ventral side of the left atrium. Furthermore, all of those patients had chronic atrial fibrillation. Transesophageal echocardiography revealed no thrombus in the area of the filling defect in the early phase. We believe that blood stasis existed in those patients. This finding leads to a false-positive result when only early phase images are obtained. The diagnosis of thrombi should be made only when a filling defect is observed in both phases. Late phase scanning is necessary in the diagnosis of left atrial thrombi.
Adult↗
Myocardial damage in patients with dilated cardiomyopathy: CT evaluation.
OBJECTIVE: The purpose of this study was to evaluate myocardial damage in patients with dilated cardiomyopathy (DCM) by ultrafast CT (UFCT) and estimate the improvement of DCM. MATERIALS AND METHODS: Seventeen patients with DCM were examined with UFCT, cardiac catheterization, left ventriculography (LVG) with manometry, and thallium myocardial scintigraphy (SCINTI). The findings of each examination were compared with each other. Especially, UFCT findings were compared with LV function. RESULTS: Late enhancement, focal wall thinning, and fatty component were detected by UFCT as focal abnormal findings. Left ventricular segments with these findings on UFCT correlated well with asynergy on LVG (p < 0.01) and perfusion defects on SCINTI (p < 0.05). Patients with these findings on UFCT showed significantly lower LV ejection fractions (p < 0.05), higher LV end-diastolic pressure (p < 0.05), and a higher incidence of ventricular tachycardia (p < 0.05). CONCLUSION: The focal myocardial abnormalities in DCM patients were well depicted with UFCT. Ultrafast CT was useful in estimating the severity of DCM and classifying the DCM patients.
Adolescent↗
Coronary artery anomalies with a shunt: evaluation with electron-beam CT.
PURPOSE: Our goal was to evaluate the role of electron-beam CT (EBT) in the diagnosis of patients with coronary artery anomalies with a shunt. METHOD: We performed EBT in seven patients with coronary artery anomalies with a shunt. Four cases were coronary artery fistula (CAF) and three were an anomalous origin of the left coronary artery from the pulmonary artery (ALCA from PA). Serial single volume mode scanning was performed at end-diastole to evaluate the anatomical course of the anomalous coronary arteries. Cine mode scanning was done in all but one to examine the ventricular wall motion and volumetrics. RESULTS: EBT could detect the course and drainage sites of all CAFs and ALCAs from PA. Cine mode scanning revealed reduced wall motion in one case with CAF and two cases with ALCA from PA. CONCLUSION: EBT serves a useful role in the assessment of coronary artery anomalies with a shunt.
Adult↗
Comparison of high resolution CT findings of sarcoidosis, lymphoma, and lymphangitic carcinoma: is there any difference of involved interstitium?
PURPOSE: The purpose of this study was to determine distinguishing features of three diseases that are distributed along the lymphatics. METHOD: CT scans of 40 patients with lymphangitic carcinomatosis, 41 with sarcoidosis, and 44 with malignant lymphoma were retrospectively reviewed. We evaluated the degree of involvement of the interlobular septa, bronchovascular structures, subpleural interstitium, and other CT findings. RESULTS: The number of thickened interlobular septa and the extent of involvement of the subpleural interstitium in lymphangitic carcinomatosis were higher than those in sarcoidosis and malignant lymphoma (p<0.0001). Nodules of >1 cm in diameter were more often seen in malignant lymphoma (41.0%) than in the other two diseases (p < 0.001). Bilateral distribution was more common in sarcoidosis (100%) than in the others (p<0.001). CONCLUSION: The major difference among lymphangitic carcinomatosis, sarcoidosis, and malignant lymphoma is the greater involvement of the interlobular septa and subpleural interstitium in lymphangitic carcinomatosis than in either sarcoidosis or malignant lymphoma.
Adult↗
Acute respiratory distress syndrome and acute interstitial pneumonia: comparison of thin-section CT findings.
PURPOSE: The purpose of this work was to compare the thin-section CT findings of acute respiratory distress syndrome (ARDS) with those of acute interstitial pneumonia (AIP). METHOD: The thin-section CT scans from 25 patients with ARDS and 25 with AIP were independently assessed by two observers without knowledge of clinical and pathologic data. The presence, extent, and distribution of various CT findings were independently analyzed. RESULTS: Honeycombing was seen more frequently in lobes of patients with AIP (26%) than in lobes with ARDS (8%) (p < 0.001). Compared with patients with ARDS, a greater number of patients with AIP had a predominantly lower lung zone distribution (p < 0.05) and a symmetric distribution (p < 0.05) of the parenchymal abnormalities. CONCLUSION: Patients with AIP have a greater prevalence of honeycombing and are more likely to have a symmetric bilateral distribution and a lower lung zone predominance than patients with ARDS. However, significant overlap exists among the CT findings.
Acute Disease↗
Invasive and noninvasive thymoma: distinctive CT features.
PURPOSE: The purpose of this work was to evaluate the CT features of thymoma and to determine the most helpful findings in differentiating invasive from noninvasive thymoma. METHOD: The CT scans from 27 patients with invasive thymoma and 23 with noninvasive thymoma were independently assessed by two observers without knowledge of their invasiveness. The presence and distribution of various CT findings were independently analyzed. RESULTS: Invasive thymomas were more likely to have lobulated (16/27, 59%) or irregular (6/27, 22%) contours than noninvasive thymomas (8/23, 35% and 1.5/23, 6%, respectively) (p < 0.05). Invasive thymomas had a higher prevalence of low attenuation areas within the tumor (16/27, 60%) than noninvasive thymomas (5/23, 22%) (p < 0.001) as well as foci of calcification (14.5/27, 54% vs. 6/23, 26%; p < 0.01). CONCLUSION: The presence of lobulated or irregular contour, areas of low attenuation, and multifocal calcification is suggestive of invasive thymoma.
Adult↗
Regional differences of serotonin-mediated synaptic plasticity in the chicken spinal cord with development and aging.
Previous studies in our laboratory [3,17] have demonstrated that serotonin (5-HT) appears to have a trophic-like effect in enhancing synapse formation and maintenance in both the developing and the adult central nervous system. In the present study, we focused on age-related changes in the density of the axosomatic and axodendritic synapses and the number of 5-HT-positive fibers in the chicken spinal cord, with special reference to differences between the ventral (laminae VII and IX) and the dorsal (lamina I) horn. At 1 week posthatching (P1W), a transient overproduction of synapses and 5-HT-immunoreactive fibers occurred in lamina IX; all parameters had returned to their initial levels by 1 month post-hatching (P1M). The density of synapses further decreased by about 40% between P6M and P2Y (2 years posthatching). Although the magnitude of the transient increase in lamina VII was less than that in lamina IX, the changing pattern of the synapses and the 5-HT-positive fibers was similar in both regions. In the ventral horn, thin 5-HT-positive fibers were most prominent at P1W and then decreased with development; thin 5-HT-positive fibers were still found at P6M but had almost disappeared by P2Y. By contrast, at P2Y the density of the synapses and the 5-HT-positive fibers in the dorsal horn was even higher than that of younger animals. Reduction of 5-HT levels in P2Y-old chickens by p-chlorophenylalanine (pCPA) administration decreased the synaptic density in lamina I but not in lamina IX. The results of this study demonstrate that 5-HT-mediated synaptic plasticity is markedly different in the ventral and dorsal horns of the aged chicken. In the ventral horn, synaptic plasticity reached a maximum at about P1W, remained stable in the young-adult period, and then finally disappeared in the aged chicken. Conversely, the results suggest that in the dorsal horn, 5-HT fibers continue to mediate the trophic influence on synaptic plasticity even in the old chicken.
Aging↗
Inhibitory effects of oolong tea extract on caries-inducing properties of mutans streptococci.
The inhibitory effects of oolong tea extract (OTE) on the caries-inducing properties of mutans streptococci were examined in vitro. OTE reduced the rate of acid production by mutans streptococci accompanied with the retardation of growth rate of mutans streptococci, while the action by chromatographically isolated oolong tea polyphenol (OTF6) was weak. On the other hand, both oolong tea products decreased cell surface hydrophobicity of almost all the oral streptococci examined in the present study, and also induced cellular aggregation of Streptococcus mutans, Streptococcus oralis, Streptococcus sanguis or Streptococcus gordonii. In these reactions, OTF6 showed a more pronounced activity than OTE. Furthermore, the oolong tea products inhibited the adherence of mutans streptococci to saliva-coated hydroxyapatite. These results suggest that OTF6 may inhibit bacterial adherence to the tooth surfaces by reducing the hydrophobicity of mutans streptococci, and OTE may inhibit caries-inducing activity of mutans streptococci by reducing the rate of acid production.
Bacterial Adhesion↗
Antibacterial activity of polyphenol components in oolong tea extract against Streptococcus mutans.
The purpose of the present study was to determine the antibacterial activity of oolong tea extract on oral streptococci, including Streptococcus mutans and Streptococcus sobrinus, and to identify the response to its components. Antibacterial activity was found when the extract was added to S. mutans cells in chemically defined medium but not in complex broth media. Further, pretreatment with bovine serum albumin reduced the antibacterial activity. The extract showed antibacterial activity against all of the oral streptococci examined, with the highest activity against S. mutans MT8148R. This activity was found to originate from a monomeric polyphenol-rich fraction, and it was stronger than that of pure polyphenols. Moreover, some combinations of monomeric polyphenols showed the highest level of antibacterial activity. These results suggest that the antibacterial activity of oolong tea extract is caused by a synergistic effect of monomeric polyphenols, which can easily bind to proteins.
Animals↗
Role of glucose side chains with serotype-specific polysaccharide in the cariogenicity of Streptococcus mutans.
Previously, we isolated and characterized a new Streptococcus mutans strain (serotype k) from human blood and oral cavity samples, and found that the serological properties of serotype k strains were similar to those of a gluA-inactivated mutant strain of MT8148 (MT8148GD). MT8148GD showed significantly lower sucrose-dependent adhesion to glass surfaces, sucrose-independent adhesion to saliva-coated hydroxyapatite, dextran-binding activity, and cell-associated glucosyltransferase (GTF) activity than the parent strain. Further, Western blot analysis revealed reduced GTFB and GTFC expression in serotype k strains as compared to MT8148, though the caries-inducing activities of MT8148GD and a serotype k oral isolate in rats were similar to that of MT8148. We conclude that a glucose side-chain defect in the serotype-specific polysaccharide of S. mutans may be associated with its cariogenicity, though to a lesser extent than its other major surface proteins.
Animals↗
Isoelectric focusing in polyacrylamide gel of the membrane proteins of Streptococcus mutans and related streptococci.
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Acrylamides↗
Inhibitory spectrum of a bacteriocinlike substance (mutacin) produced by some strains of Streptococcus mutans.
Streptococcus mutans strains were surveyed to determine their lysogenicity. Growth inhibition of the indicator strains around the inoculum of stab culture of some S mutans strains was demonstrated. Many gram-positive bacteria, including mycobacteria and streptomycetes, were sensitive to the antibacterial activity.
Bacteria↗
Effect of dextranase prepared from Spicaria violacea on dental caries in the hamster.
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Animals↗
Three-dimensional CT imaging of aneurysm of aberrant right subclavian artery.
We report a case of an aneurysm originating from an aberrant right subclavian artery, which was incidentally found as a compression deformity of the upper esophagus on a barium study in a 46-year-old man. Computed tomography (CT) clearly demonstrated the aneurysm of the aberrant right subclavian artery. In particular, reconstructed three-dimensional CT (3D-CT) was valuable in evaluating the positional relationships between the anomalous vessel with aneurysm and other structures.
Aneurysm↗