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Biomedical subjects

S Sakato

Publications and source records attributed to S Sakato.

9 recordsLinked to original sources
PubMed1992

Hereditary motor and sensory neuropathy with calf muscle enlargement.

We report three related patients with autosomal dominant hereditary motor and sensory neuropathy (HMSN). An unusual and characteristic feature was calf enlargement, caused by muscle fiber hypertrophy predominantly of type 1 fibers. None of the family members showed atrophy of the legs. Sural nerve pathology disclosed marked loss of myelinated fibers and numerous onion bulb formations. While cases of HMSN with calf muscle hypertrophy have been reported, the present pedigree was different from that in any of the previous cases in that no family member showed clinically apparent leg atrophy.

Adolescent↗
PubMed1990

[Brainstem infarcts presented medial longitudinal fasciculus (MLF) syndrome and cerebellar ataxia--report of three cases].

Vascular disorders of the brainstem manifest characteristic neurologic symptoms according to their localization. The medial longitudinal fasciculus (MLF) lies in the paramedian portion of the upper brainstem tegmentum, and the lesion in this fasciculus shows specific abnormality of the eye movement pattern which is known as the MLF syndrome. Although the MLF syndrome was reported frequently to be accompanied by varieties of other neurologic deficits according to the lesion extending into the adjacent structures in the brainstem, the combination of MLF syndrome and cerebellar ataxia has attracted less attention of neurologists. Recently we experienced three cases of cerebellar ataxia arisen simultaneously with MLF syndrome. Magnetic resonance imaging (MRI) tomography or X-ray computed tomography visualized lacunar lesion(s) in the upper brainstem tegmentum in all of three cases. It was obvious that the lesion included the MLF and caused the MLF syndrome in these cases. It was speculated that ventro-caudal extension of the lesion involved the decussation of the superior cerebellar peduncle, and was responsible for the association of cerebellar ataxia with MLF syndrome. According to the recent discussion about the feeding arteries in the brainstem, we decided that the damage of the paramedian branches diverging from the basilar tip resulted in the lacunar lesion(s). The development of diagnostic procedures especially MRI enables the diagnosis of the vascular disorders in the brainstem with considerable accuracy.

Aged↗
PubMed1979

[The high pressure liquid chromatography of corticoids. II. Analysis of synthetic corticoids in blood and urine (author's transl)].

The high pressure liquid chromatographic (HPLC) technique was developed to separate and quantitate the synthetic corticosteroids (s-CS) which are widely used clinically. 1) 12 kinds of s-CS in alcoholic solvent and 2) some of their metabolites in the plasma and urine of healthy subjects with oral administration of s-CS were investigated for the preliminary work. The results are summarized as follows: 1) Cortisol sodium phosphate, Dexamethasone 21, disodium phosphate, Paramethasone acetate, Cortisol acetate, Cortisone acetate, Methylprednisolone acetate, Prednisone, Dexamethasone, 9 alpha-fluorocortisol, Betamethasone, Triamcinolone, and Prednisolone in ethanol were clearly separated by HPLC from Cortisol (F). In the suitable condition of the HPLC (LC-2 type) with a Zorbax SIL column, organic solvent (cyclohexane:dichloromethane:ethanol = 9:4:1)-carrier mobile phases and UV detector, the retention time of each s-CS was obviously different from that of F. The calibration curve was obtained in a linear line with regards to each s-CS. The mean recovery was 97.6% and the coefficient of variation were 1.6 (intraassay) and 7.2 (interassay)%. The sensitivity of the steroid determination was 200pg order. 2) The serial changes in plasma concentrations of s-CS; CS-metabolites and endogenous F were shown in 3 healthy males and 2 females following oral administration of the s-CS. The separated metabolites in number and quality depended on the kind of s-CS. Prednisone and other kinds of the acidified products were separated from prednisolone in the plasma and urinary samples of the healthy subjects as well as Addisonian patients. In conclusion, the HPLC method is useful for the separation and quantitation of the UV-absorbing CS of human plasma and urine. The obtained chromatograms may be an indication of the metabolic state of the subject with treatment of s-CS.

Adrenal Cortex Hormones↗
PubMed1979

A unique affinity and adaptation of renomedullary interstitial cells for hypertonic medium.

Collagenase-dispersed cells of renal papillary tissue from adult mongrel dogs were directly inoculated in a modified M.E.M. (Eagle's) giving an osmolality of approximately 1,000 mOsm/L by addition of urea and sodium chloride, and were cultured in an atmosphere of 95% air-5%CO2 at 37 degrees C. Within twelve hours after inoculation, spindle-shaped cells attached firmly to the surface of culture dishes, while the other cellular components of the inner medulla remained floating in the medium. After several days in culture, the colonies grew to form a confluent cell layer, which was composed of almost homogenous cells giving spindle-shape. These cells kept on the major characteristics of renomedullary interstitial cell (RIC) in morphology as well as in function to produce prostaglandin E. These results appear to be principally attributable to the unique characteristics of RIC, one of which is affinity for high osmolality and the other is different behavior in attachment to the dish. As the procedure proposed here was relatively simple and did not require a long period up to the development of monolayer, it would provide a promising model "in vitro" to study the humoral regulation of prostaglandin production.

Animals↗
PubMed1977

Electron microscopy of the mouse optic nerve: a quantitative study of the total optic nerve fibers.

The total number of myelinated and unmyelinated nerve fibers was counted in a montage of electron micrographs prepared to cover the entire profile of the mouse optic nerve in transverse section. Many astrocytic processes form a barrier structure all around the optic nerve. As a whole, the mouse optic nerve consists of one fascicle where the nerve fibers, the glia cells and their processes, and the capillaries are fitted closely together to fill substantially all of the available space. No tissue space accompanied with connective tissue septa penetrates into the fascicle, except for those situated around the arteriole and venule. The total number of 64,746 myelinated nerve fibers in the optic nerve in one side was counted. This corresponds to about 98.8% of the total number of the optic nerve fibers. The total number of 807 unmyelinated nerve fibers was also counted. This corresponds to about 1.2% of the total nerve fibers. The external diameter of every myelinated fiber, including the myelin sheath, was measured on the montage micrograph and its frequency distribution was examined. The diameter of the myelinated fibers ranges from 0.3 to 4.2 mu and its mean value is 0.96 mu. The frequency distribution of fiber diameter is unimodal with a peak at 0.7 to 0.9 mu. A regional heterogeneity in fiber size is found in the optic nerve. The nerve fibers in the peripheral area of the nerve are relatively small and uniform in diameter, whereas those in the central area show a fairly wide range in diameter.

Animals↗
PubMedDate not supplied

A case of new daily persistent headache with elevated antibodies to Epstein-Barr virus.

A 45-year-old woman presented with persistent headache which was of acute onset and occurred daily. Laboratory findings included thrombocytosis, elevated levels of antinuclear antibody, rheumatoid factor, and antibodies to Epstein-Barr virus (EBV). Magnetic resonance image of the head, left selective external carotid angiography, temporal arterial biopsy, and cerebrospinal fluid revealed no abnormal findings that could explain her headache. Her headache was compatible with NDPH, which has been reported by Vanast, and was thought to be related to EBV reactivation.

Antibodies, Viral↗