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Biomedical subjects

Y Terao

Publications and source records attributed to Y Terao.

123 records · Page 7Linked to original sources

Sequential production of Birbeck granules through adsorptive pinocytosis.

A case of vitiligo with inflammatory raised borders was observed electron microscopically, resulting in an interesting view of the formation of Birbeck granules in Langerhans cells. Following the formation of larger coated vesicles, which perform adsorptive pinocytosis from the cell membrane, membrane invagination of the cell occurred shown as the tubular infolding, resulting in the observation of the characteristic Birbeck granule band pattern in its interior. This phenomenon supports the theory of Hashimoto and Tarnowski (1968) that Birbeck granules are formed from the infolding of the cell membrane. In addition, our study shows the involvement of adsorptive pinocytosis in the formation of the granules. It was suggested that when the coated Birbeck granule shifts into the cell, possibly its coat is detached and the vesicle portion forms the globule of the Birbeck granule.

Adult↗

High melanosome engulfing activity of cutaneous fibroblasts in macular amyloidosis: an electron microscopic study.

Six patients with macular amyloidosis were investigated by electron microscopy and various morphological changes in fibroblasts were identified. Many cells, which seemed to be macrophages by light microscopy, proved to be fibroblasts. The digesting action of fibroblasts was well developed and many melanosomes were taken into the cells making the cells resemble melanophages. The fibroblasts extended long, thin and branched cytoplasmic processes to surround the amyloid mass, and the cells selectively extended these into the narrow spaces between collagen and amyloid. The fibroblast showed highly developed endocytotic activity and probable ingestion of amyloid by pinocytosis or phagocytosis. The developed rough endoplasmic reticulum contained much protein and was active in secretion.

Amyloidosis↗

Median raphe cyst of the penis.

A case of median raphe cyst of the penis in a 7-year-old boy is reported. Although the lesion is rare, characteristic clinical features makes it easy to diagnose median raphe cyst of the penis, which has been mistakenly reported as apocrine hidrocystoma. Surgical excision must be performed to prevent recurrence.

Child↗

Macular amyloidosis with patchy filamentous degeneration of collagen islands.

Unusual patchy filamentous degeneration of collagen islands, found in a typical case of macular amyloidosis, is described. This phenomenon was found to begin in intact islands scattered among the amyloid islands in the papillary and upper reticula dermis. Since the patches varied in size, they were thought to have grown gradually with time. They were derived from the degeneration of collagen fibrils and demonstrated a tropocollagen-like structure. Although the small patches preserved some characteristic structures of collagen fibrils or tropocollagen, the large patches showed amyloid-like filamentous masses surrounding the collagen islands.

Amyloidosis↗

Assay of 25-hydroxyvitamin D3 in human plasma by high-performance liquid chromatography.

A method using preparative and analytical high-performance liquid chromatography (HPLC) is proposed for the assay of 25-hydroxyvitamin D3 (25-OH-D3) in human plasma. A constant volume (0.2--2.0 ml) of a plasma sample was saponified. The unsaponifiable matter was first applied to preparative HPLC using a column of the straight-phase type (Zorbax SIL) in order to separate a 25-OH-D3 fraction from lipophilic concomitants giving ultraviolet-absorbing noise. Then, the separated 25-OH-D3 fraction was applied to analytical HPLC using a column of the reversed-phase type (Zorbax ODS) in order to measure the content of 25-OH-D3 from the peak height. This is a revised method from Jones (1978): Clin. Chem., 24, 287--298). The results showed that the clean-up procedure by the first preparative HPLC was successfully performed because the peak corresponding to 25-OH-D3 on the chromatogram of the second analytical HPLC was not disturbed by any other interfering peaks. Moreover, recovery through the whole procedure was satisfacotry (about 100%) and the procedures of saponification and isolation of the unsaponifiable matter diminished the overload to the columns. These are the revised points of Jones' method. When two determinations were performed on 12 samples of plasma taken from normal adults in October, the values were 22.6 +/- 4.8 and 21.0 +/- 3.6 (mean +/- SD) ng/ml, respectively.

Adult↗

Intracardiac flow dynamics with bi-directional ultrasonic pulsed Doppler technique.

1) Intracardiac flows were investigated by bi-directional pulsed Doppler technique with a combined use of the two-dimensional echocardiography. The flow at sampling sites in the heat and great vessels were correctly identified on the two-dimensional echocardiograms. 2) Soundspectrographic analysis of the flow Doppler signals was useful in obtaining information about flow modes and in differentiating flow signals from those of valves. 3) In healthy subjects, intracardiac flow revealed a laminar mode. As a matter of interest, a flow toward the aorta, which is a cranially turned flow, was found at the center and at the outflow tract of the left ventricle from mid to late diastole. 4) In mitral stenosis, the central stream at the stenotic portion exhibited an almost laminar and rapid flow. A good coincidence in flow mode was observed between clinical cases of mitral stenosis and experimental stenosis. 5) Disturbed flows were observed in the following diseased conditions. The diastolic regurgitant flow in the left ventricular outflow tract and mitral inflow in aortic regurgitation, the regurgitant flow into the left atrium and the diastolic mitral inflow in mitral regurgitation, the ejection flow in hypertrophic cardiomyopathy with outflow tract obstruction, and the tricuspid inflow in atrial septal defect. 6) Mechanisms of intracardiac flow dynamics were also discussed.

Adolescent↗

Pathophysiology of sensorimotor cortex in cortical myoclonus.

We have studied greatly enhanced cortical responses to somatosensory stimuli [giant somatosensory evoked potential (SEP) or magnetic field (SEF)] and cortical activities preceding the myoclonus (premyoclonus spike) in patients with cortical myoclonus, using magnetoencephalographic (MEG) techniques. A P1m component of giant SEF was estimated as a dipole positioned on the postcentral gyrus in all giant SEFs. This indicates that abnormally enhanced responses to sensory stimuli originate from the sensory cortex. In most of the patients with cortical reflex myoclonus, a dipole for the premyoclonus spike was also localized on the postcentral gyrus, which suggests that abnormal activation of the sensory cortex produces the spontaneous myoclonus. In one patient with galactosialidosis, two dipoles, one on the postcentral and the other on the precentral gyrus, could reasonably explain the premyoclonus spike. In the other patient with cortical reflex myoclonus, the premyoclonus spike associated with jerks of the lower limb muscle was estimated to be one dipole on the superior frontal gyrus just anterior to the paracentral lobule. This suggests that both spontaneous myoclonus and enhanced long loop reflex are generated by abnormal activation of the motor cortex in this patient. In a patient with epilepsia partialis continua who had no long loop reflexes, the premyoclonus spike was demonstrated to be positioned on the precentral gyrus, which indicates that abnormal activation of the motor cortex causes the spontaneous myoclonus in this patient. Our MEG studies demonstrated that abnormalities of the sensory or motor cortices contribute differently to the generation of myoclonus in cortical myoclonus, despite the fact that the sensory cortex is the main contributor in most of them.

Electric Stimulation↗