[Mixed connective tissue disease (MCTD) with severe acute pancreatitis].
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Acute Disease↗
Biomedical subjects
S Nishida
Publications and source records attributed to S Nishida.
Time perception: brain time or event time?
Recent experiments show that synchronous events can appear to an observer to occur at different times. Neural processing time delays are offered as an explanation of these temporal illusions, but equating perceived time with processing time leads to some thorny philosophical problems.
Brain↗
1alpha-Hydroxyvitamin D3 suppresses trabecular bone resorption by inhibiting osteoclastogenic potential in bone marrow cells after ovariectomy in mice.
To test the hypothesis that 1alpha-hydroxyvitamin D3 (1alpha(OH)D3) suppresses bone resorption after ovariectomy (ovx) by inhibiting osteoclastogenic potential in bone marrow cells, the bilateral tibiae of ddY mice, 8 weeks of age, subjected to ovx were obtained. 1alpha(OH)D3, at doses of 0, 0.2 (low dose), or 0.4 microg/kg body weight (high dose), was administered orally by canula three times a week for 2 or 6 weeks. Histomorphometric analysis of the proximal tibiae revealed that 1alpha(OH)D3 administration had no significant effect on trabecular bone volume of ovx limbs, which was reduced after ovx. The bone formation rate, increased by ovx, was significantly decreased by the administration of high-dose 1alpha(OH)D3. The ovx-induced increases in osteoclast number and surface at 2 weeks postsurgery were suppressed by the administration of high-dose 1alpha(OH)D3. With regard to bone marrow cells, the number of nonadherent cells per tibia obtained from ovx limbs increased, and this increase was suppressed by the administration of low- and high-dose 1alpha(OH)D3. The formation of mineralized nodules in marrow cultures obtained from ovx limbs was increased after surgery and unaltered by 1alpha(OH)D3 administration. The number of osteoclast-like multinucleated cells obtained from ovx limbs was reduced by low- and high-dose 1alpha(OH)D3 administration alike. The number of colony forming units-fibroblast and the number of colony forming units for granulocytes and macrophages was unaltered by ovx or the administration of 1alpha(OH)D3. The present study clearly demonstrates that high-dose 1alpha(OH)D3 suppresses osteoclast numbers and surface after ovx. The inhibitory effects of low- and high-dose 1alpha(OH)D3 on bone marrow cells after ovx were marked in the differentiation from osteoclast precursors to mature osteoclasts. Administration of 1alpha(OH)D3 suppressed ovx-promoted trabecular bone resorption by inhibiting osteoclastogenic potential in bone marrow cells.
Alkaline Phosphatase↗
A motion aftereffect seen more strongly by the non-adapted eye: evidence of multistage adaptation in visual motion processing.
We found that the motion aftereffect measured using a directionally ambiguous counterphase grating (flicker MAE) can be stronger when it is measured for the non-adapted eye than when measured for the adapted eye. The monocularly viewed adaptation stimulus was the movement of a missing-fundamental grating (2f+3f motion), for which the movement of the higher-order spatial structure was dominantly perceived, while the first-order structure was physically moving in the opposite direction. For observers who perceived the MAE consistently in the direction opposite to the movement of the higher-order structures, the MAE was larger for the non-adapted eye than for the adapted eye. This finding of 'over-100% transfer' invalidates the standard view that the IOT is a direct measure of the binocularity of the adapted neurones. In addition, the finding provides convincing support for the hypothesis that the flicker MAE reflects adaptation at multiple processing stages
Adaptation, Physiological↗
Temporal resolution of orientation-based texture segregation.
We analysed the temporal-frequency characteristics of two functional processes involved in orientation-based texture segregation: local orientation coding and subsequent orientation-contrast coding. Two texture images, in which each micropattern was rotated by 90 degrees, were alternated at various temporal frequencies. A micropattern was a second-derivative (D2) of a Gaussian that loses orientation information when temporally fused with the orthogonal D2 pattern. We measured the upper temporal-frequency limits for localising the target region whose mean orientation differed from the background by 90 degrees or by 45 degrees. If the temporal limit of the texture perception is determined by the most sluggish processing stage, the temporal limit for the 90 degrees texture should be determined by local orientation coding or by orientation-contrast coding, depending on which stage has the lower temporal precision. On the other hand, the 45 degrees texture should always be segregated below the temporal limit of local orientation coding regardless of the temporal limit of orientation-contrast coding. We found that the temporal limit for the 90 degrees texture was slightly higher than that for the 45 degrees texture under spatial conditions appropriate for texture segregation. Moreover, an orientation-noise analysis of segregation performance for a wide range of temporal frequencies revealed that the temporal-frequency sensitivities for the two textures were nearly identical. These results imply that the temporal limit for orientation-based texture segregation depends only on that of local orientation coding. This conclusion further suggests that the potential temporal resolution of orientation-contrast coding is not lower than that of local orientation coding, which would imply that the orientation-contrast coding is unlikely to be mediated by sluggish neural processes.
Contrast Sensitivity↗
Micropattern orientation and spatial localization.
A current, popular, theory of spatial localization holds that the visual system represents the location of simple objects by a single positional tag, the accuracy of which is largely independent of the internal properties of the object. We have already presented evidence of the limitations of such a view (Keeble & Hess (1998). Vision Research, 38, 827-840) in that 3-micropattern alignment performance was found to be dependent on the orientation of the micropatterns. We tested whether this was caused by a local anisotropy in positional coding by conducting 3-micropattern bisection experiments with varying patch orientation. No corresponding effect of patch orientation was found, implying a difference in the mechanisms used for the two tasks. In a further experiment we show that alignment task performance is very similar to the otherwise identical 2-patch orientation discrimination task. We conclude that the 3-micropattern alignment task is mediated by orientational mechanisms. We therefore present a 2nd-order orientation model for 3-patch alignment.
Anisotropy↗
Inhibitory effect of histamine on axonal transport in cultured mouse dorsal root ganglion neurons.
Histamine is important in mediating peripheral sensory information such as inflammation, allergic hypersensitivity, and itch. In the present study, using video-enhanced microscopy, we investigated the effect of histamine on axonal transport in cultured dorsal root ganglion (DRG) neurons of the mouse. Application of histamine (100 microM) reversibly reduced the number of particles transported within neurites in both anterograde and retrograde directions. The histamine H(1)-receptor agonist 2-thiazolylethylamine (100 microM) and the H(3)-receptor agonist R-alpha-methylhistamine (100 microM) also reduced anterograde and retrograde axonal transport, whereas the histamine H(2)-receptor agonist dimaprit (100-1000 microM) had no effect. The effect of histamine was partially blocked by pretreatment with H(1)-receptor antagonist pyrilamine (1 microM) or the H(3)-receptor antagonist thioperamide (1 microM). Pretreatment with a combination of pyrilamine (1 microM) and thioperamide (1 microM) completely blocked the response to histamine. The H(2)-receptor antagonist cimetidine (1 microM) was ineffective. These results suggest that histamine inhibits axonal transport of cultured mouse DRG neurons via the activation of H(1)- and H(3)-receptors.
Animals↗
Morphological and functional differentiation of human thyroid cells in collagen gel culture.
OBJECTIVE: Cultured human thyroid cells in collagen gel culture were examined on cell morphology and the production of thyroglobulin (Tg), triiodothyronine (T3) and thyroxine (T4) which are components of functional differentiation. METHODS: Thyroid cells obtained from normal human thyroid tissues (four cases), follicular adenoma tissues (three cases), papillary carcinoma tissues (three cases), and follicular carcinoma tissue (one case), were cultured in collagen gel. Then these cultured cells were observed on cellular morphology and production of Tg, T3 and T4. Moreover, changes in morphological characteristics and production of Tg, T3 and T4 induced by addition of thyroid stimulating hormone (TSH) and epidermal growth factor (EGF) to medium in collagen gel culture were determined. RESULTS: Normal and tumor cells in collagen gel culture formed colonies and follicles with Tg production, similar to in vivo-like three-dimensional cellular structures and functions. Normal thyroid cells stimulated TSH induced more Tg and produced morphological changes, i.e. enlarged follicular lumens and increased the height of follicular cells, but did not promote cell proliferation. Reversely, normal thyroid cells stimulated with EGF promoted cell proliferation, but did not change morphological findings and did not increase production of Tg, T3 and T4. CONCLUSIONS: These findings suggest that collagen gel culture is useful for observing the effects of stimulation by cell growth factor on the morphological and functional differentiation of human thyroid cells.
Cell Differentiation↗
Domino liver transplantation with end-to-side infrahepatic vena cavocavostomy.
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Aged↗
Effect of trabecular bone contour on ultimate strength of lumbar vertebra after bilateral ovariectomy in rats.
To test the hypothesis that the effect of trabecular microarchitecture on bone strength varies with the duration of estrogen loss, we evaluated the relationship between three-dimensional (3D) parameters for trabecular microarchitecture and bone minerals with the compressive load of the lumbar vertebra in rats. Female Sprague-Dawley rats (n = 190) were divided into 19 groups. Ten rats were killed at day 0. Half of the remaining rats underwent bilateral ovariectomy (ovx), and the others were subjected to sham surgery. Ten rats from each group were killed at 3, 7, 11, 14, 28, 42, 56, 70, and 84 days postsurgery. Urinary deoxypyridinoline and serum osteocalcin increased significantly in the ovx group from days 28 and 11, respectively, compared with the sham group. Bone mineral content (BMC) and bone mineral density (BMD) of the fifth lumbar body diminished from days 42 and 84, respectively, compared with the sham group. In ovx rats, trabecular bone volume (BV/TV), measured using 3D images of microcomputed tomography, diminished from day 28 compared with both baseline control and sham. The trabecular bone pattern factor (TBPf) and structure model index (SMI) increased from day 28 in the ovx group compared with both baseline control and sham. Ultimate compression loads diminished at day 28 compared with baseline control and decreased progressively thereafter. Neither of these parameters changed in the sham group during the same period. Within 4 weeks post-ovx, TBPf, SMI, and BV/TV correlated with load (p < 0.01). BMC and BMD correlated with load from 6 weeks post-ovx (p < 0.01). Stepwise regression analysis showed that TBPf was the most significant determinant of load within 4 weeks post-ovx (coefficient of determination [R(2)] = 0.669; p < 0.01). SMI correlated with TBPf (R(2) = 0.968; p < 0.01). Moreover, R(2) for ultimate load indicated higher values of 0.975 with TBPf and SMI. However, BMC was the most significant determinant of load from 6 weeks post-ovx (R(2) = 0.511; p < 0.01), as it was in the sham group. These data suggest that changes in trabecular bone contour with increased bone turnover are critical for reducing lumbar bone strength during the early post-ovx period in rats.
Amino Acids↗
Thoracoabdominal bypass graft with liver retransplantation for the treatment of a pseudoaneurysm of the supraceliac aorta after liver transplantation.
Pseudoaneurysm following liver transplantation is a rare but life-threatening complication. Treatment is directed towards control of fatal bleeding. Ligation with or without revascularization of the graft is the treatment of choice. When revascularization is not possible, or the liver does not tolerate the arterial blood deprivation, retransplantation is the only option. We report a case of a 14-month-old girl who developed a pseudoaneurysm at the anastomosis between the recipient supraceliac aorta and the donor graft. The pseudoaneurysm was excised and the aorta was ligated above and below it. An extra-anatomical thoracoabdominal arterial graft was used to provide arterial blood supply to the lower torso and also to arterialize a new orthotopic liver graft. This is the first reported case of the use of thoracoabdominal jump graft to vascularize a transplanted liver.
Anastomosis, Surgical↗
Markov process amplitude EEG model for spontaneous background activity.
The Markov process amplitude (MPA) EEG model effectively representing spontaneous brain activity of the EEG was introduced. The relationship between the electrical mechanism for EEG generation and the proposed model was also investigated. The MPA EEG model was described by the sinusoidal waves with the randomly fluctuating amplitude of the first-order Markov process. The parameters of the MPA EEG model were determined optimally based on the real EEG records. The results of model outputs in the frequency domain demonstrated an excellent fit with the power spectrum of the corresponding EEG. The simulated model signal in the time domain also showed good agreement with the EEG time series. The satisfactory results from the MPA EEG model suggest its possible applicability in clinical practice. Furthermore, from the high goodness of fit, the authors think that the neurons oscillate at fixed frequencies and are modulated by synaptic interactions in accordance with the first-order Markov process.
Adult↗
Cyclooxygenase-1 and cyclooxygenase-2 selectivity of non-steroidal anti-inflammatory drugs: investigation using human peripheral monocytes.
Since the pharmacological profiles of various non-steroidal anti-inflammatory drugs (NSAIDs) might depend on their differing selectivity for cyclooxygenase 1 (COX-1) and 2 (COX-2), we developed a new screening method using human peripheral monocytes. Monocytes from healthy volunteers were separated, and the cells were incubated with or without lipopolysaccharide (LPS). Monocytes without LPS stimulation exclusively expressed COX-1 on Western blotting analysis, whereas LPS stimulation induced COX-2 expression. Unstimulated monocytes (COX-1) and LPS-stimulated monocytes (COX-2) were then used to determinethe COX selectivity of various NSAIDs. The respective mean IC50 values for COX-1 and COX-2 IC50 (microM), and the COX-1/COX-2 ratio of each NSAID were as follows: celecoxib, 82, 6.8, 12; diclofenac, 0.076, 0.026, 2.9; etodolac, > 100, 53, > 1.9; ibuprofen, 12, 80, 0.15; indometacin, 0.0090, 0.31, 0.029; meloxicam, 37, 6.1, 6.1; 6-MNA (the active metabolite of nabumetone), 149, 230, 0.65; NS-398, 125, 5.6, 22; piroxicam, 47, 25, 1.9; rofecoxib, > 100, 25, > 4.0; S-2474, > 100, 8.9, > 11; SC-560, 0.0048, 1.4, 0.0034. The percentage inhibition of COX-1 activity at the IC50 of COX-2 also showed a wide variation among these NSAIDs. The bioassay system using human monocytes to assess the inhibitory effects of various NSAIDs on COX-1 and COX-2 may become a clinically useful screening method.
Anti-Inflammatory Agents, Non-Steroidal↗
Surgical treatment of primary cardiac tumors: 28 years' experience in Kanazawa University Hospital.
To examine the clinical features of primary cardiac tumors, 34 patients who underwent surgical treatment from 1973 to 2000 at the Kanazawa University Hospital were analyzed and the literature was reviewed. The 34 patients were divided into 3 categories: (i) myxomas; (ii) benign non-myxomas; and (iii) malignant tumors. Twenty-three patients (70%) were diagnosed with myxomas, including 22 left atrial myxomas and 1 right atrial myxoma. Seven patients (18%) were diagnosed with benign non-myxoma tumors, including 3 hemangiomas, 1 fibroma, 1 rhabdomyoma, 1 pheochromocytoma, and 1 lipoma. Four patients (12%) were diagnosed with malignant tumors, including 2 angiosarcomas, 1 rhabdomyosarcoma, and 1 malignant fibrous histiocytoma. Among the myxoma patients, in-hospital mortality was 9% (2/23), late mortality was 10% (2/21), and no recurrent myxomas have been identified. Among benign non-myxoma patients there were no perioperative deaths; however, 1 patient died 11 years after surgery, with no linked cause. No recurrent tumors have been identified. Among malignant tumor patients, 1 patient died the day following surgery and the rest died within 14 months. Early and late results of surgery were acceptable for those patients with benign tumors, while the prognosis for patients with malignant tumors was very poor.
Adolescent↗
Right ventricular cardiomyopathy accompanied by protein-losing enteropathy and chylous effusion.
Severe right-side heart failure developed in a 47-year-old Japanese woman who suffered from hypoalbuminemia and a massive right side chylous pleural effusion. She had been diagnosed as having protein-losing enteropathy with right ventricular cardiomyopathy. Autopsy showed congenital anomalies of the lymph ducts and abnormal deposition of fibrous and fatty tissue in the right ventricular myocardium. The clinical and pathological findings are consistent with the nonarrythmogenic form of the arrythmogenic right ventricular dysplasia.
Adult↗
A non-arthropathic dose and its disposition following repeated oral administration of ofloxacin, a new quinolone antimicrobial agent, to juvenile dogs.
A non-arthropathic dose and disposition of ofloxacin, a potent new quinolone antimicrobial agent, were assessed in male juvenile (3-month-old) dogs, when administered orally at 5, 10 and 20 mg/kg/day once daily for 8 consecutive days. Ofloxacin concentrations in sera and articular cartilages were analyzed by high-performance liquid chromatography (HPLC). Macroscopically, arthropathy characterized by fluid-filled vesicles in articular surface of the humerus and femur was observed in animals receiving 10 and 20 mg/kg/day of ofloxacin, but not in those given 5 mg/kg/day. At 20 mg/kg/day, arthropathy of comparable severity also occurred on day 2. Microscopically, the cavity formation in the middle zone of the articular cartilage was first identified and then necrotic chondrocytes were found numerous around the cavity, followed by appearance of chondrocyte clusters. In pharmacokinetics, peak serum concentration (Cmax) and area under the concentrations (AUC0-24) were increased in a dose-dependent manner. However, no remarkable differences in these two parameters were noted between a single and repeated treatments, suggesting no accumulation of the drug. The articular ofloxacin concentration 2 hr after treatment was approximately 1.8 (day 2) to 2.0 times (day 8) higher than the serum concentration. Based on these results, a non-arthropathic dose of ofloxacin in male juvenile dogs following an 8-day treatment is considered to be 5 mg/kg/ day, and its Cmax, AUC0-24 and articular cartilage concentrations 2 hr after treatment were 3.4 microg/ml, 35.1 microg-hr/m/ and 7.0 microg/g, respectively, under these experimental conditions. Thus, arthropathy due to ofloxacin may be predicted by monitoring serum drug concentration.
Administration, Oral↗
Visual response saturation to orientation contrast in the perception of texture boundary.
We analyzed how the visual response to orientation modulation in texture patterns varied as a function of the magnitude of orientation contrast. Using a contrast-discrimination technique, we measured threshold increments of orientation contrast (the orientation contrast required for discriminating between two textures) at various pedestal-orientation contrasts. The orientation-contrast-response function estimated for a step-orientation contrast, which produces a vivid percept of surface boundaries, saturated at approximately 30 degrees (experiment 1). The saturation was still evident even when the strength of the step-orientation contrast was reduced by orientation noise (experiment 2), but no strong saturation was found for textures that did not produce a vivid percept of surface boundaries (experiment 3). These results are consistent with the notion that orientation-based texture segregation involves the generation of a neural representation of the surface boundary whose strength is nearly independent of the magnitude of orientation contrast.
Contrast Sensitivity↗
Cathepsin L activity and its inhibitor in human otitis media.
OBJECTIVE: We examined cathepsin L activity, expression of cystatin A, and copper- and zinc-containing superoxide dismutase in human chronic otitis media. The relationships of our findings to clinical findings (e.g., grade of bone destruction) were also studied. DESIGN: Retrospective basic and clinical study. SETTING: Department of Otolaryngology and First Department of Biochemistry, Kinki University School of Medicine, Osaka, Japan. METHOD: The human middle ear tissues evaluated in this study were surgically obtained from seven patients with cholesteatoma epithelium, three patients with granulation tissues in cholesteatoma, three patients with granulation tissues in noncholesteatoma, and three patients with intact mucous membrane of the middle ear. MAIN OUTCOME MEASURES: Cathepsin L activities in cholesteatoma epithelium, granulation tissues in cholesteatoma, or granulation tissues in noncholesteatoma were measured using Barrett's method. Cystatin A expressions were observed by Western blot analysis. Copper- and zinc-containing superoxide dismutase in cholesteatoma was examined immunohistochemically. RESULTS: Mean cathepsin L activity was higher in diseased tissues than in intact mucous membranes of the middle ear. Granulation tissues with high cathepsin L activity resulted in extensive bone destruction in both cholesteatomas and noncholesteatomas of the middle ear. All cases with intact mucous membrane of the middle ear exhibited no expression of cystatin A. Seven of 10 cases with diseased tissues expressed cystatin A in cholesteatoma epithelium, granulation tissues in cholesteatoma, or granulation tissues in noncholesteatoma. No relationships were found between cystatin A expression and grade of cathepsin L activity. Copper- and zinc-containing superoxide dismutase was more strongly positive in cholesteatoma epithelium regions than in granulation tissues. CONCLUSION: These results suggest that copper- and zinc-containing superoxide dismutase in cholesteatoma epithelium prevents complications by suppressing cathepsin L activity.
Cathepsin L↗