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Biomedical subjects

S Tsuji

Publications and source records attributed to S Tsuji.

At least 667 records · Page 37Linked to original sources
PubMed1993

Phosphatidylserine specific binding protein in rat brain: purification and characterization.

A calcium-independent phosphatidylserine specific binding protein detected on liposome blotting analysis was purified from rat brain and revealed to be identical to myristoylated, alanine-rich C kinase substrate (MARCKS). MARCKS specifically binds to phosphatidylserine but not phosphatidylcholine. The binding of MARCKS to phosphatidylserine was abolished on protein kinase C-dependent phosphorylation. Since bacterially expressed MARCKS also specifically binds to phosphatidylserine, myristoylation of the N-terminal glycine seems not to be essential for the binding of MARCKS to phosphatidylserine. These data suggest that phosphatidylserine is a membranous target molecule of MARCKS.

Amino Acid Sequence↗
PubMed1993

Activation of human lysosomal sialidase.

An acid sialidase [EC 3.2.1.18], partially purified from human placenta by Con A-Sepharose adsorption and p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatographies, was activated by incubation at 37 degrees C. This activation showed both time and temperature dependencies, with the most effective activation observed at 37 degrees C in the pH range between 4.3 and 5.2. The influence of various protease inhibitors on its activation was investigated. Among the protease inhibitors tested, amastatin, an inhibitor of aminopeptidase A, significantly inhibited activation. The partially purified enzyme preparation contained aminopeptidase activity, which was inhibited by amastatin. Zinc ions inhibited either the activation of sialidase or the aminopeptidase activity in the enzyme preparation. These results suggest the possibility of participation of aminopeptidase function in the activation process of sialidase.

Aminopeptidases↗
PubMed1993

High resolution Tc-99m HMPAO SPECT in a patient with transient global amnesia.

This is a report of a patient who underwent high-resolution brain perfusion SPECT studies during and after an episode of transient global amnesia. During the attack, SPECT imaging showed increased perfusion in the left medial temporal region involving the amygdala and hippocampus. After recovery from amnesia, a follow-up SPECT examination showed slightly decreased perfusion in this region. These findings support the hypothesis that transient global amnesia is associated with transient hyperperfusion in the medial temporal brain structures, and confirm the utility of high-resolution SPECT imaging for the evaluation of the fine details of functional brain anatomy.

Adult↗
PubMed1993

Comparative SPECT study of stroke using Tc-99m ECD, I-123 IMP, and Tc-99m HMPAO.

Brain perfusion SPECT imaging using Tc-99m ethyl cysteinate dimer (ECD) was carried out in 12 patients with chronic cerebrovascular disease. The sensitivity of lesion detection and lesion-to-normal tissue contrast was compared with those of I-123 IMP and Tc-99m HMPAO. Eight patients underwent all three studies and the remaining four patients had Tc-99m ECD and I-123 IMP scans. The sensitivity of lesion detection and lesion contrast was analyzed quantitatively using an asymmetric index determined by the equation: 100 x [right - left[/(right + left). In the cerebral cortex, cerebellum, and white matter, I-123 IMP showed higher lesion sensitivity than Tc-99m ECD and Tc-99m HMPAO. In the striatum and thalamus, Tc-99m ECD and I-123 IMP showed higher lesion sensitivity than Tc-99m HMPAO. I-123 IMP showed the highest lesion contrast in cerebral cortex and cerebellum, whereas Tc-99m ECD showed the highest contrast in thalamus and striatum. In all regions, Tc-99m ECD showed higher lesion contrast than Tc-99m HMPAO. These results suggest regional variation in the sensitivity of lesion detection and lesion contrast of Tc-99m ECD compared to I-123 IMP, and the superiority of Tc-99m ECD to Tc-99m HMPAO.

Adult↗
PubMed1993

Heritable unstable DNA sequences and hypermethylation associated with fragile X syndrome in Japanese families.

Fragile X syndrome, associated with the fragile site at Xq27.3 (FRAXA), is the most common form of familial mental retardation. The fragile X mutation has recently been characterized as a heritable unstable DNA sequence, p(CCG)n/p(CGG)n, in the FRAXA locus. In the present study, a correlation between fragile X-genotypes in the FRAXA locus and hypermethylation of an adjacent CpG island was examined in four Japanese families with fragile X syndrome. We show here that the heritable unstable DNA sequences in the fragile X chromosome usually increase in size when transmitted by female carriers, and that the degree of methylation in the CpG island correlated with the increased sizes of the unstable DNA sequences. When a hypermethylated full mutation was transmitted by a male to his daughters, both the size of the unstable DNA sequence and the degree of the methylation reduced to the premutation range. Our observations suggest that female meiosis has a greater potential for amplifying unstable DNA sequences and that amplified DNA sequences can be transmitted through germ cells, while male germ cells seem not to be able to tolerate highly amplified unstable DNA sequences.

Base Sequence↗
PubMed1993

Role of endogenous endothelin in pathogenesis of ethanol-induced gastric mucosal injury in rats.

The major objective of this study was to elucidate the role of endogenous endothelin (ET)-1, a potent vasoconstrictor peptide, in the pathogenesis of ethanol (EtOH)-induced gastric mucosal injury. Two series of experiments were performed in anesthetized rats. First, we examined the time course of relationships among changes in ET-1 concentrations in gastric mucosal and portal plasma, gastric mucosal hemodynamics, and mucosal damage produced by EtOH. Intragastric EtOH stimulated release of endogenous ET-1 in gastric mucosal tissue. Plasma ET-1 concentrations in the portal vein also increased after intragastric EtOH administration. ET-1 concentrations in gastric mucosal tissue and portal plasma increased significantly before gastric mucosal hemorrhagic damage occurred. Moreover, 30 min after EtOH administration there were significant correlations between gastric mucosal ET-1 concentrations and both area of gastric hemorrhagic damage as well as concentration of EtOH administered intragastrically. After intragastric EtOH administration, increase in gastric mucosal hemoglobin concentration and decrease in gastric mucosal hemoglobin oxygen saturation, estimated using reflectance spectrophotometry, occurred within 2.5 min and continued throughout the experiments. The time course of microcirculatory changes correlated closely with increases in gastric mucosal ET-1 and portal plasma ET-1 concentrations after intragastric EtOH administration. Gastric microcirculatory disturbances induced by EtOH were associated with significant decreases in gastric mucosal ATP content. Second, we examined whether pretreatment with anti-ET-1 antibody protected against EtOH-induced mucosal injury by improving mucosal microcirculation. Pretreatment with anti-ET-1 antibody microscopically and macroscopically reduced gastric mucosal hemorrhagic damage induced by EtOH and significantly reduced EtOH-induced gastric microcirculatory disturbances and decreases in gastric mucosal ATP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Isolation of 353 NotI-linking clones and 62 DNA markers (DXS607-DXS668) from human chromosome Xq24-->qter.

Through restriction enzyme digestion of 1,784 cosmid DNAs derived from human chromosome region Xq24-->qter, we identified 353 NotI-linking cosmids (11 individual groups of overlapping NotI-linking cosmids at Xq24-->q25.6 groups at Xq26-->q27, and 19 groups at Xq28). Sixty-two of the 353 clones (DXS607-DXS668) contained multiple rare-cutter sites, including multiple SacII sites within a 2-kb region, as well as one to six sites for BssHII, MluI, NotI, or NruI.

Cosmids↗
PubMed1993

Cortical somatosensory potentials evoked by magnetic stimulation of thoracic and lumbar roots.

We applied twin coil magnetic stimulation to thoracic and lumbar roots to evaluate the posterior column function in 50 normal subjects and 34 patients with neurologic disorders. In all nine patients with cervical myelopathy, there were abnormal somatosensory evoked potentials (SEPs) with stimulation of upper thoracic levels. In 14 patients with thoracic or lumbar myelopathy, there were normal SEPs with stimulation of spinal roots above the lesions and abnormal SEPs with stimulation below the lesions. In a patient with girdle sensation between T-3 and T-6, the peak latencies of P2 were significantly delayed with stimulation of T-2 and T-4, but peak latencies were normal with T-6, T-10, and L-3 stimulation. Ten patients with polyneuropathy had normal SEPs recorded with thoracic and lumbar root stimulation. SEPs by twin coil stimulation at thoracic and lumbar root levels are useful in detecting lesions of spinal cord or roots and for following their clinical course noninvasively.

Adolescent↗
PubMed1993

Frequent presence of anti-GQ1b antibody in Fisher's syndrome.

We used the enzyme-linked immunosorbent assay to investigate autoantibodies against the gangliosides GM1, GD1a, GD1b, GT1b, GD2, and GQ1b in sera from 16 patients with Fisher's syndrome. We found high anti-GQ1b antibody titers, mainly those of the IgG class, in the sera of 13 of these patients. The titers decreased with the clinical course of the illness. Moreover, anti-GQ1b antibody-positive patients had more severe ataxia of cerebellar type than the antibody-negative patients.

Adult↗
PubMed1993

Uniform tissue distribution of tRNA(Lys) mutation in mitochondrial DNA in MERRF patients.

We documented the presence of a point mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA) in various postmortem tissues from two patients with myoclonus epilepsy associated with ragged-red fibers (MERRF). The percentages of the mutant mtDNA were similar (93 to 99%) in both clinically affected and unaffected tissues, suggesting that preferential clinical involvement of certain tissues in MERRF is based not only on the variation of distribution of the mutant mtDNA, but also on other factors such as differences in the threshold in various CNS regions and organs.

Adult↗
PubMed1993

Sudomotor potential evoked by magnetic stimulation of the neck.

We studied the sudomotor potential in the palm of the hand, evoked by magnetic stimulation of the neck, in 15 normal subjects and five patients with dysautonomia. The potentials consisted of two positive peaks (S1, S2), with mean (+/- SD) onset latencies of 408.5 +/- 31.8 and 619 +/- 61.4 msec. The sudomotor potential was clearly obtained only from the palm and was influenced by stimulus intensity, coil position, current direction in the coil, atropine or pilocarpine iontophoresis, and motor effort. With this method, we estimated the postganglionic sympathetic conduction time and the central reflex time, the mean values (+/- SD) of which were 408.5 +/- 31.8 and 323.3 +/- 45.2 msec. In three patients with severe dry skin, the sudomotor potential and the sympathetic skin response were not obtained. A patient with OPCA had a prolonged central reflex time, and a patient with alcoholic polyneuropathy showed a delayed sudomotor potential. Sudomotor potential is a noninvasive and useful method for evaluating sympathetic sudomotor function in patients with central and peripheral nervous system disorders.

Adult↗
PubMed1993

Influence of chronic oestrogen treatment on severity of hydronephrosis in inbred DDD mice.

It has been reported that mice treated chronically with oestrogen (oestradiol propionate) increase their bladder urine volume. Since inbred DDD mice, particularly male DDD mice, lack a protective mechanism against vesicoureteral reflux (VUR), chronic oestrogen treatment may increase the pressure in the renal pelvis and lead to severe hydronephrosis. The present studies were carried out to confirm this hypothesis. Results of a least-squares analysis of variance showed that the severity of hydronephrosis was more severe after treatment with high doses of oestrogen (1.0 and 5.0 mg/kg/week) in entire and castrated male DDD mice. Hydroureter was also observed in the same groups. Intra-vesicular pressure was 7 to 12 cmH2O higher in mice of these groups than in control DDD mice. High doses of oestrogen had no effect on the kidneys of C57BL/6 mice which showed normal protection against VUR, though it increased bladder urine volume. These findings support the hypothesis that hydronephrosis in DDD mice is caused by an incomplete protective mechanism against VUR.

Animals↗
PubMed1993

Identification of inbred strains of mice and genetic relationships between strains as assessed by DNA fingerprinting.

Strain identification and the assessment of genetic relationships among inbred strains of mice were examined by DNA fingerprinting using M13 phage DNA as a probe. We used 8 inbred strains (NC/Jah, DDD/Jah, DSD/Jah, RR/Jah, SS/Jah, C3H/HeJah, C57BL/6 Jah and C57BL/6CrSlc) and coisogenic (NC-brp) as well as congenic (C57BL/6-bg) strains. DNA fingerprints using M13 phage DNA as a probe revealed identical patterns within strains. Bands due to new mutations in minisatellite regions within each strain were not observed. The banding patterns were strain-specific. Thus, DNA fingerprinting seemed to be suitable for genetic monitoring of mice. A dendrogram constructed with difference values calculated from DNA fingerprint patterns showed that relationships among strains reflected the history of these strains, so DNA fingerprinting could also be effectively used to assess the relationships between inbred strains of mice.

Animals↗
PubMed1993

[Application of DNA fingerprinting to investigation of genetic relationships between laboratory rabbit strains].

It is well known that laboratory rabbits are not controlled genetically like laboratory mice and rats. In order to test the usefulness of DNA fingerprinting in investigation of genetic uniformity of the laboratory rabbits strains and their relationships, we applied DNA fingerprinting using bacteriophage M13 probe to five strains (2 inbreds (JWY-NIBS and DuY-NIBS) and 3 outbreds (JW-NIBS, Icl:JW and WHHL)). DNA fingerprints of 2 inbred strains showed the same banding patterns within each strain but the strain-specific patterns. Although there were no rabbits showing the same banding patterns in 3 outbred strains, average percent differences (APD) were 13.7 to 18.6. A dendrogram based on APD of DNA fingerprints was constructed by 2 large clusters, JW group and DuY. The dendrogram was essentially similar to that based on rabbit mandible measurements. These results suggest that DNA fingerprinting is available not only for the genetic monitoring of the laboratory rabbit strains but also for the investigation of their genetic relationships.

Animals↗
PubMed1993

Sinus and atrioventricular nodal re-entrant tachycardia.

A case of a 42-year-old woman who had combined sinus and atrioventricular nodal tachycardia is reported. Programmed atrial stimulation study showed the induction of the two types of paroxysmal supraventricular tachycardia. The mechanisms of these supraventricular tachycardias were both sinus nodal and atrioventricular re-entrant tachycardia. Sinus nodal re-entrant tachycardia could be induced only after injection of atropine. The tachycardias could no longer be induced after the administration of verapamil.

Adult↗
PubMed1993

Shy-Drager syndrome with abnormal circadian rhythm of plasma antidiuretic hormone secretion and urinary excretion.

A 67-year-old patient with Shy-Drager syndrome (SDS), exhibited nocturnal polyuria associated with abnormal circadian rhythm of antidiuretic hormone (ADH) secretion and nocturnal polyuria. The patient excreted a larger volume of urine during the nighttime compared to that in the daytime. The specific gravity of urine at night was lower than that during the day. In contrast to normal circadian rhythm of ADH, the patient's plasma concentration of ADH was increased in the daytime. The present study raised the possibility that an altered circadian rhythm of plasma ADH secretion might be considered a result of the neurodegenerative changes involving the hypothalamus.

Aged↗
PubMed1993

[Studies on the preparation of sample solution for determination of nicotinic acid and nicotinamide in foods by high performance liquid chromatography].

A method for preparation of sample solution for determination of nicotinic acid (NA) and nicotinamide (NAA) in foods by high performance liquid chromatography has been studied. NA and NAA were simultaneously extracted from foods with methanol, then the extracts were cleaned up by use of a Sep-Pak tC18 cartridge. NA and NAA in each sample solution were determined by high performance liquid chromatography. Recoveries of NA and NAA from various foods spiked at levels of 25 and 250 micrograms/g were not less than 70%.

Chromatography, High Pressure Liquid↗