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Biomedical subjects

I Kato

Publications and source records attributed to I Kato.

At least 307 records · Page 17Linked to original sources
PubMed1994

Changing patterns in the prevalence of dementia in a Japanese community: the Hisayama study.

We compared type-specific prevalences of dementia between two surveys of Hisayama residents > or = 65 years old conducted in 1985 and 1992. The overall age-adjusted prevalence was greatly decreased from 5.4% in 1985 to 3.3% in 1992 for men, while it was changed little from 7.5 to 6.3% for women. The prevalence of vascular dementia (VD) decreased during the intervening 7 years in men but not in women. The prevalence of Alzheimer's type (SDAT) was the same in either sex. The ratio of VD to SDAT prevalence was 1.8 in 1985 but fell to 1.1 in 1992. The background factors responsible for this change are discussed.

Age Distribution↗
PubMed1994

Angiogenic activity of a fusion protein of the cell-binding domain of fibronectin and basic fibroblast growth factor.

We constructed a fusion protein of the cell-binding domain of human fibronectin and human basic fibroblast growth factor, and prepared a polypeptide with both cell-adhesive activity and growth factor activity. A human gene fragment coding for basic fibroblast growth factor was amplified by the polymerase chain reaction, and introduced into the expression vector pTF7520, which encodes the cell-binding domain of human fibronectin. The resulting plasmid encoded a fusion protein in which basic fibroblast growth factor was added covalently to the C-terminal end of the fibronectin fragment. The fusion protein was expressed in Escherichia coli JM109 cells and purified from the extract by heparin affinity chromatography. The purified fusion protein had cell-adhesive activity toward BALB/c 3T3 cells, and stimulated their DNA synthesis in serum-depleted cultures. The fusion protein gave maximum mitogenic activity at the concentration of 10 nM. The fusion protein adsorbed to culture dishes, or added to collagen gels, stimulated the growth of human umbilical-vein endothelial cells. The fusion protein stimulated the angiogenesis in chorioallantoic membranes of developing chick embryos.

3T3 Cells↗
PubMed1994

Postoperative changes in the contralateral auditory brainstem response after microvascular decompression in cases of trigeminal neuralgia.

Postoperative changes in auditory brainstem response (ABR) in 40 patients with trigeminal neuralgia (TN) who underwent microvascular decompression (MVD) were analyzed. A high proportion (60%) were found to have a decrease in the latency of wave V in the contralateral (unaffected) ABR in the postoperative period. In some cases, a decrease in the latency of wave V was found on the unaffected side postoperatively while an increase was found on the affected side. Furthermore, in one case it was found that an improvement of the shortened latency of wave V on the unaffected side occurred in parallel with a recovery of prolonged latency on the affected side. This indicates that the decrease in the latency of wave V on the unaffected side corresponds to some retrocochlear lesion produced by MVD on the affected side, and shortened latency is considered to be a result of damage to the efferent system of the auditory pathway.

Adult↗
PubMed1994

Slow saccades and quick phases of nystagmus after pontine lesions.

A patient was referred to the university hospital to test eye movements after she had suffered cerebellar hemorrhage one month previously. Examination showed a selective deficit of saccades and quick phases of nystagmus toward the lesion site in the horizontal plane, which was later confirmed pathologically, and which corresponded precisely to the paramedian pontine reticular formation (PPRF). This may suggest that velocities in the quick phase of nystagmus, whether visual or vestibular, and saccades show the same result in PPRF lesion and they share the same neural circuitry in cells located in the PPRF. In the present study, the non-linear saccade velocity-amplitude equation was best-fitted to this patient. Quantitative evaluation of the quick phase may provide a simple and quick reference in saccade slowing.

Brain Diseases↗
PubMed1994

Quantitative assessment of influence of aging on optokinetic nystagmus.

A quantitative assessment of the influence of aging on optokinetic nystagmus (OKN) was investigated using 50 normal adults in ages ranging from 30 to 70 years. In linear stimulus-induced OKN, a statistically significant difference was demonstrated in slow-phase OKN velocity only between the 30-59 year old age group and the 70-79-year-old age group, when OKN stimulus was more than 60 degrees/s. Step stimulus-induced OKN was investigated in the same age groups in order to compare aging effects upon slow-phase OKN velocity. No statistically significant difference was found in slow-phase OKN velocity between younger age groups and the oldest age group. There was no significant difference in fast-phase velocity among the age groups. Thus, step-induced OKN has a wider clinical application than linear stimulus-induced OKN.

Adaptation, Physiological↗
PubMed1994

Computer analysis for routine electronystagmography tests.

A computer program has been developed for on-line analysis of routine electronystagmography (ENG) tests. With this system, data acquisition of eye movements and stimulus signals obtained from ENG are accomplished at a rate of 200 Hz through a 12-bit analog-digital converter. A small spotlight for eye tracking tests is sinusoidally driven by a computer-generated analog signal. Six optokinetic stripes projected onto a screen are also controlled by the computer. Seven spots for saccade tests can be turned on or off based on digital signals produced through a digital output device. There are three types of eye movements in this series: nystagmus, pursuit eye movement and saccadic eye movement. An algorithm for the analysis of different eye movements is described in this paper. Recent significant advances in computer technology make it possible to perform such complicated tasks and to accomplish quantitative assessment of any type of eye movements in routine ENG tests. Consequently, computer analysis provides clues to the location of a disease and is very useful as a diagnostic tool in routine ENG testing.

Artifacts↗
PubMed1994

Rebound positional nystagmus as a peripheral origin.

Three cases of rebound positional nystagmus (RPN) are discussed in the present study. In all cases, spontaneous nystagmus was absent in the primary position, but positional nystagmus appeared in the side down position, and then nystagmus in the reversed direction appeared when the patient was returned to the primary position. The characteristics of RPN in the cases we studied were very similar to those of benign positional nystagmus. Tinnitus was accompanied with vertigo in Cases 2 and 3, and the glycerol tests were positive in Cases 1 and 3. There were no other abnormalities of ocular movements, neurological and neuroradiological examinations suggestive of central nervous system disorders indicating that RPN can be ascribed to peripheral lesions. A selective review of the literature is presented.

Electrooculography↗
PubMed1994

Role of the prepositus hypoglossi nucleus on primary position upbeat nystagmus.

Electrolytical destruction of the floor of the fourth ventricle was performed on 10 cats in order to produce primary position upbeat nystagmus (PPUN). In 5 cats who had unilateral lesions of the floor of the fourth ventricle, PPUN was never seen. Two of the remaining 5 cats, who had bilateral lesions, showed PPUN. In 2 cats with PPUN, the oculomotor level of the caudal fourth ventricle, in order that PPUN may be developed, it is necessary that the prepositus hypoglossi nucleus (PH) be destroyed bilaterally. The present experiment suggests that bilateral PH lesions could result in a tonic imbalance for eye positions and eye movements of the vertical axis, resulting in a downward drift with a corrective saccade; PPUN.

Animals↗
PubMed1994

The effect of uvulonodular lesions on horizontal optokinetic nystagmus and optokinetic after-nystagmus in cats.

The effect of uvulonodular lesions on horizontal optokinetic nystagmus (OKN) and optokinetic after-nystagmus (OKAN) was investigated in alert cats. A lesion in each of 6 cats was made by suction-ablation under anesthesia. In the 3 cats with only a uvular lesion, both the initial slow phase velocity and the time constant of OKAN were unchanged. In the remaining 3 cats whose lesions included the nodulus as well as the uvula, the time constant of OKAN was markedly prolonged, but the initial slow phase velocity of OKAN was not affected. The postoperative average time constant of OKAN increased from the normal value of 9 s to about 40 s. In contrast, OKN parameters (the steady-state velocity and the rising time constant) were not affected by uvular or uvulonodular lesions. These results strongly suggest that the nodulus is involved in the velocity storage mechanism and might control the discharge characteristics of the velocity storage integrator.

Animals↗
PubMed1994

[Mortality from major causes of death and its risk factors in the elderly--26-year follow-up study in Hisayama].

The authors studied mortality from major causes of death and risk factors in the elderly in a long-term prospective survey conducted in a Japanese suburban community, Hisayama. In the baseline survey in 1961, we scrutinized 1658 residents of the town aged 40 years or older accounting for 92% of the total population in this age range. Of those, 591 residents (245 men and 346 women) aged 60 years or older, who were free from major cardiovascular disease, were selected for the present study. They were followed-up for 26 years from 1961 to 1987. The average age was 67 years for men and 70 years for women, being significantly higher for women than for men. During the follow-up period, 529 subjects (89.5%) died, and 448 were autopsied (autopsy rate 84.7%). The all-cause mortality (per 1,000 person-years) after adjustment for age was 89.9 for men and 56.7 for women, the former being significantly higher than the latter (p < 0.01). The age-adjusted mortality from cerebrovascular disease was estimated to be 21.4 for men and 9.9 for women, i.e. 8.9 and 8.8 from heart disease, and 19.9 and 10.6 from neoplasm, and 18.1 and 12.2 from-pneumonia, respectively. There was significant sex difference in mortality from cerebrovascular disease, neoplasm and pneumonia (p < 0.01) but not from heart disease (p > 0.1). Multiple Cox's proportional hazards regression analysis showed systolic blood pressure and male sex to be significant risk factors for death by cerebrovascular disease. Systolic blood pressure was also a predictor for death by heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1994

Hyperinsulinaemia and blood pressure in a general Japanese population: the Hisayama Study.

OBJECTIVES: To study the relationship between serum insulin and blood pressure, as well as the prevalence of hypertension according to the insulin level in a general Japanese population. DESIGN: In 1988 a cross-sectional community survey was conducted among Hisayama residents aged 40-79 years. METHODS: A total of 1073 males and 1407 females (72.5 and 80.5% of the total population, respectively) underwent comprehensive investigation, including a 75-g oral glucose-tolerance test. Fasting and 2-h serum insulin levels were measured by radioimmunoassay. RESULTS: The sum of the fasting and 2-h postloading insulin levels was significantly correlated with the systolic blood pressure (SBP; r = 0.18 and 0.26 for males and females, respectively) and the diastolic blood pressure (DBP; r = 0.24 and 0.19, respectively) in the subjects not receiving antihypertensive drugs. In multiple regression analysis the correlation with blood pressure remained significant in both sexes even after controlling for age, body mass index, alcohol intake, smoking, a family history of hypertension, serum total cholesterol and fasting plasma glucose. The age- and sex-adjusted prevalence of hypertension (SBP > or = 160 mmHg or DBP > or = 95 mmHg, or both, or receiving drug treatment) increased significantly with an increase in the sum of fasting and 2-h postload insulin levels in both the non-obese subjects (body mass index < 25 kg/m2) and the obese subjects (body mass index > or = 25 kg/m2). Multiple logistic regression showed that the sum of fasting and 2-h postload insulin levels was a significant factor with an independent relationship to hypertension, even after taking the other risk factors into account. CONCLUSION: The present study suggests that hyperinsulinaemia is related to hypertension in a general Japanese population.

Adult↗
PubMed1994

[Effect of free radicals on the permeability of the blood brain barrier--using in vitro blood brain barrier model of human-SOD transgenic mouse].

Free radicals have been implicated in pathogenesis of vasogenic edema caused by post-ischemic reperfusion injury. It has been reported that Cu-Zn superoxide dismutase transgenic mouse (tg-mouse) which is overexpressing Cu-Zn SOD, prevents post ischemic brain edema and decreases infarct size in middle cerebral artery occlusion model. To investigate the effects of free radicals and free radical scavengers on the permeability of the blood-brain barrier (BBB), we established in vitro BBB model, using cultured brain endothelial cells (BECs) which were extracted from the tg-mice and non tg-mice (control). To make the BBB model, the BECs were cultured on the membrane which has 0.45 micron pores. After cells became confluent, the electrical resistance across the cell monolayer, which reflects the para-cellular flux of ionic molecules, was measured. The BBB model of the tg-mouse were incubated with menadione (Vitamin K3, intracellular O2- producting agent), and the segmental changes of the electrical resistance through the monolayer were compared with those of the control. Moreover, to investigate the effect of the ironic ions which influence the metabolism of free radicals, desferroxamine mesylate (Fe chelating agent) was added to the BBB models before menadione treatment. The cultured brain endothelial cells of tg-mouse has 1.7 times higher SOD activity than that of the control. In the menadione treatment, it showed a significant decrease of electrical resistance in the tg-mouse earlier than that of the control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Non-isotopic restriction mapping of cosmid DNA.

A protocol for the non-isotopic restriction mapping of cosmid DNA was developed. After digestion with lambda terminase and partial digestion with restriction enzymes, DNA fragments containing right or left cohesive cos termini were selectively captured by hybridization with biotinylated oligonucleotides, bound to magnetic beads coated with streptavidin and recovered by heating. Recovered DNA fragments containing cos ends were resolved by agarose gel electrophoresis, and fluorescence from the DNA fragments in the ethidium bromide-stained gel was detected with the fluorescent image analyzer, FMBIO. Restriction maps were directly determined from the ladder of the partial digestion products. Two micrograms of cosmid DNA for each partial digestion were sufficient for mapping the restriction enzyme sites. This procedure provides a prototype for other cos sequence-mediated or other specific sequence-mediated DNA isolation technologies and a convenient method for non-isotopic DNA analysis. The rapid physical analysis of cosmid DNA that we present here will contribute to large DNA structural analyses like the human genome project.

Base Sequence↗
PubMed1994

Analysis of oligosaccharides of human IgG from serum of leukemia patients.

The biantennary N-acetyllactosamine type oligosaccharide is attached to asparagine-297 of the human IgG heavy chain, which is an integral part of the tertiary structure of the Fc region, and is quite important in the role of IgG. Pyridylamination and analysis by HPLC can be performed more rapidly and simply than conventional carbohydrate analysis. We applied it to the analysis of the oligosaccharide structures of IgG from the serum of patients with leukemia, CLL and AML. The proportion of oligosaccharide from leukemia patients with a bisecting N-acetylglucosamine residue was almost equal to that of healthy individuals. However, the proportion of fucose and galactose residues differed. These data suggest that the analysis of the fucose and the terminal galactose residue of such oligosaccharides will be useful in the classification of leukemia.

Acetylglucosamine↗
PubMed1993

Hemolytic toxin produced by Porphyromonas gingivalis.

Porphyromonas gingivalis no. 381 and ATCC 33277 produced an extracellular hemolytic toxin which was heat-labile, trypsin-sensitive, and lytic to human, horse, sheep and rabbit erythrocytes. The hemolytic toxin is a 'hot-cold', thiol-independent toxin. The production of the hemolytic toxin was greatly enhanced by addition of hemoglobin to the culture medium.

Cold Temperature↗
PubMed1993

Molecular cloning and cDNA sequencing of endoxyloglucan transferase, a novel class of glycosyltransferase that mediates molecular grafting between matrix polysaccharides in plant cell walls.

Endoxyloglucan transferase is a novel class of glycosyltransferase recently purified from Vigna angularis (Nishitani, K,, and Tominaga, R. (1992) J. Biol. Chem. 267, 21058-21064). This enzyme is the first transferase identified that catalyzes molecular grafting between polysaccharide cross-links in the cell wall matrix and participates in reconstruction of the network structure in the cell wall. Based on the NH2-terminal amino acid sequence information of the purified transferase, we have here cloned and sequenced cDNAs derived from five different plant species, V. angularis, Triticum aestivum, Arabidopsis thaliana, Lycopersicon esculentum, and Glycine max. In the five plant species, the amino acid sequence of the mature proteins is conserved in the range of 71-90% throughout their length. The consensus sequence for N-linked glycosylation, and four cysteine residues are all conserved in the five species. Thus, the endoxyloglucan transferase protein is ubiquitous among higher plants. The highly conserved DNA sequence will serve as a promising tool for exploring the molecular process by which cell wall construction, and hence cell growth, is regulated.

Amino Acid Sequence↗