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M Ushiyama

Publications and source records attributed to M Ushiyama.

32 records · Page 2Linked to original sources
PubMed1991

Transthyretin-type cerebral amyloid angiopathy in type I familial amyloid polyneuropathy.

To clarify the pathogenesis of cerebrovascular amyloid deposits, histological and immunocytochemical studies were performed on the central nervous system (CNS) in ten cases with type I familial amyloid polyneuropathy (FAP). They commonly suffered from peripheral somatic and autonomic nerve disorders without any CNS dysfunctions. However, all cases showed CNS amyloid deposits, mainly on the leptomeningeal vessels and pia-arachnoid membranes, with arteries and arterioles in the subarachnoidal space being the predominant site of cerebral amyloid accumulation. Using immunocytochemical staining methods with antibodies to amyloid beta-protein, human cystatin C and transthyretin (prealbumin), all of these amyloid deposits were specifically immunolabeled by the anti-human transthyretin antibody. However, there was no transthyretin-related amyloid deposits in the brain parenchyma. It is concluded that CNS transthyretin-immunoreactive amyloid deposition with cerebral amyloid angiopathy (CAA) is a common pathological finding in this disease. Moreover, the patients with type I FAP are known to have an amyloid protein precursor (a variant of transthyretin) in serum. This transthyretin type of CAA, therefore, seems to be an example of cerebrovascular amyloid deposits derived from a serum precursor.

Adolescent↗
PubMed1991

Noradrenergic nerve fibers of the rectal mucosa in autonomic disorders: comparison of histochemical study with clinical severity and changes in plasma noradrenaline induced by standing.

A histochemical study was carried out on the rectal mucosae biopsied from 20 patients with autonomic dysfunctions and 13 controls using a catecholamine fluorescent staining method, and the rectal noradrenergic nerve fiber lesions were compared with the severity of autonomic symptoms and disturbance of plasma noradrenaline increase in response to standing in 17 patients. In 9 patients with type I familial amyloid polyneuropathy and 1 with acute pandysautonomia, the number of fluorescent nerve fibers was greatly reduced, and the degree of depletion correlated well with the other 2 parameters showing the severity of autonomic dysfunction. In contrast, rectal noradrenergic nerve fibers were normally preserved in 10 patients with multiple system atrophy, although they suffered from severe autonomic symptoms with poor noradrenaline response to the postural loading. It is concluded that noradrenergic nerve fiber lesions in the biopsied rectal mucosa may represent the systemic involvement of sympathetic post-ganglionic nerves.

Adult↗
PubMed1988

Effect of alpha-human atrial natriuretic peptides on intraocular pressure in normal albino rabbits.

The effect of alpha-human atrial natriuretic peptide (alpha-hANP) on the intraocular pressure (IOP) was studied in normal rabbits. Dose response studies to IOP were performed after intravenous administration of alpha-hANP at 6.25, 12.5, 25.0, 50 and 100 micrograms/kg to the rabbits. The maximum reduction in IOP was observed to occur with the alpha-hANP 50 micrograms/kg dose. The time course of the pressure response to alpha-hANP were measured prior to and following intravenous administration of 50 micrograms/kg of alpha-hANP. The change in IOP and blood pressure showed the same pattern in the simultaneous record. Silver grains of 125I-alpha-hANP (10 microCi/g body weight) were detected in the ciliary processes of mice by radioautography after intravenous injection. The pupillary response was not tested in this experiment. The mechanism of IOP reduction was discussed.

Animals↗
PubMed1986

Ultrastructural findings of rectal and skin biopsies in adult GM1-gangliosidosis.

We report the ultrastructural findings in rectal and skin biopsies in four cases with adult GM1-gangliosidosis. The rectal specimens taken under endoscopic control contained submucosal plexuses, which were easily identified on light-microscopic and electron-microscopic examination. In all cases the ganglion cells in submucosal plexus contained characteristic osmiophilic lamellar inclusions, some of which were typical membranous cytoplasmic bodies, were commonly observed in the ganglion cells, Schwann's cells, vascular endothelial cells, and perithelial cells in rectal biopsy, and membrane-bound clear vacuoles were occasionally seen in the cytoplasm of rectal and cutaneous fibroblasts. However, the axons of unmyelinated nerves in both biopsies showed a normal appearance, and there was no significant change in the eccrine glands in skin biopsy. Comparing rectal and skin biopsies, the former was found to be more valuable for morphological diagnosis of this disease, and our ultrastructural examination of rectal biopsy revealed that enteric nerve cells were involved even in adult GM1-gangliosidosis with a benign course and restricted cerebral lesions.

Adult↗
PubMed1985

Type III (chronic) GM1-gangliosidosis. Histochemical and ultrastructural studies of rectal biopsy.

Type III GM1-gangliosidosis is a rare hereditary storage disease caused by lack of lysosomal beta-galactosidase and characterized by a slowly progressive course, and extrapyramidal signs, but without prominent skeletal changes or visceromegaly. The storage substance was reported to be located only in the basal ganglia. There has been no detailed report on visceral lesions in type III GM1-gangliosidosis. In this report we describe a case of type III GM1-gangliosidosis, and the histochemical and ultrastructural findings from biopsied rectum. The patient was a 22-year-old female who exhibited dysarthria, gait disturbance, and generalized dystonia with rigidity. Beta-galactosidase activity in leukocytes was absent and sialidase activity in cultured fibroblasts was normal. Many histiocytes were found in biopsied rectal mucosa. Histochemical studies showed that the granules of histiocytes contained acidic glycoconjugates, beta-galactose, beta-N-acetylgalactosamine and sialic acid. Ultrastructural investigations revealed that ganglion cells of Meissner's plexus had many osmiophilic lamellar inclusions, similar to "membranous cytoplasmic bodies". These findings are crucial for the clinical diagnosis of type III GM1-gangliosidosis.

Adult↗
PubMed1979

Water permeability of yeast cells at sub-zero temperatures.

A combined cryomicroscopic-multiple nonlinear regression analysis technique has been used to determine the water permeability of the yeast cell Saccharomyces cerevisiae during freezing. The time rate of change in volume of "supercooled" yeast cells was photographically monitored using a "cryomicroscope" which is capable of controlling in a programmable manner both the temperature and the time rate of change in temperature of the cell suspension being studied. Multiple nonlinear regression analysis together with a thermodynamic model of cell water transport during freezing was then used to statistically deduce the subzero temperature dependence of the cell water permeability. The water permeability process for S. cerevisiae being cooled at subzero temperatures was found to be rate-limited by the passage of water through either the plasmalemma, the cell wall, or a combination of these two permeability barriers. The hydraulic water permeability coefficient for yeast at 20 degrees C is approximately 1--2 x 10(-13) cm3/dyne sec, if extrapolation from subzero temperatures to room temperature is permissible, while the apparent activation energy governing the permeability process at subzero temperatures is approximately 45--68 kJ/mol (11--16 kcal/mol).

Cell Compartmentation↗