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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 289 records · Page 16Linked to original sources
PubMed1995

Sustained increase of methylguanidine in rats after amygdala or hippocampal kindling.

Methylguanidine (MG) and guanidinoacetic acid (GAA) are known to be endogenous convulsants in the mammalian brain. We have reported previously that MG and GAA concentrations were significantly elevated bilaterally in the amygdala (AM) 7 and 28 days after completion of AM kindling. In the present study, we investigated regional changes in MG and GAA in (1) AM-kindled rat brain 3 months after completion of kindling and (2) hippocampal (HIPP)-kindled rat brain 7 and 28 days after completion of kindling, using high-performance liquid chromatography. MG was increased significantly in the kindled AM 3 months after completion of AM kindling (76%, P < 0.05). Significant increases in MG levels were also found 7 and 28 days after completion of HIPP kindling (124%, P < 0.025 and 110%, P < 0.05, respectively) in the left AM, ipsilateral to the kindled site. GAA increased significantly (93%, P < 0.025) only in the left AM, ipsilateral to the kindled site, 7 days after completion of HIPP kindling. These results, together with our previous data, indicate that long-lasting increases of MG occur in the AM regardless of kindled foci, and may be important in producing neuronal hyperexcitability in kindled epileptogenesis.

Amygdala↗
PubMed1995

Rat epidermal cathepsin B: purification and characterization of proteolytic properties toward filaggrin and synthetic substrates.

The aim of this study was to purify epidermal cathepsin B from rat skin and investigate its proteolytic activities on filaggrin and several synthetic substrates. The molecular weight of purified monomeric cathepsin B was estimated to be 30 kDa by SDS-polyacrylamide gel electrophoresis. The amino acid composition, similar to that of liver cathepsin B, indicated the enzyme to be an acidic protease. The enzyme had strong hydrolytic activity toward N-benzyloxy-carbonyl-L-arginyl-L-arginine-7-amido-4-methylcoumarin (Z-Arg-Arg-MCA) (152 mU/mg) and N-benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amido-4-methylcoumarin (424 mU/mg), but had no proteolytic activity toward L-arginine-7-amido-4-methylcoumarin. The Km value for Z-Arg-Arg MCA was 0.34 mM and pH optimum was 5.5. Cathepsin B degraded rat epidermal filaggrin into small fragments at pH 4.0 and 5.5., and was inhibited by a specific cysteine proteinase inhibitor, N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)L-leucyl]- agmatin. This study demonstrated that filaggrin was susceptible to degradation by cathepsin B. Such an action may have relevance to skin differentiation in which acid proteases are thought to participate.

Animals↗
PubMed1995

Mapping and characterization of a sequential epitope on the rabies virus glycoprotein which is recognized by a neutralizing monoclonal antibody, RG719.

We have established a murine hybridoma cell line RG719 which produces a rabies virus-neutralizing IgM-type monoclonal antibody (referred to as MAb RG719). Immunoblot analysis indicated that the antibody recognized a sequential epitope of G protein. Among four rabies virus strains tested, the antigenicity to MAb RG719 was absent from the Nishigahara strain, while the other three strains (HEP, ERA and CVS) reacted to the MAb. Studies with deletion mutants of the G protein indicated that the epitope was located in a middle region of the primary structure of G protein, ranging from position 242 to 300. By comparing the estimated amino acid sequence of the four strains, we found in this region two amino acids (at positions 263 and 291) which are common to three of those strains but are not shared by the Nishigahara strain. The site-directed point mutagenesis revealed that replacement of phenylalanine-263 by leucine destroyed the epitope of the HEP G protein, while the epitope was generated on the Nishigahara G protein whose leucine-263 was replaced by phenylalanine. These observations suggest that phenylalanine-263 is essential for constructing the epitope for MAb RG719. The synthetic 20-mer peptide produced by mimicking the amino acid sequence (ranging from amino acid positions 249 to 268) of the presumed epitope region was shown to bind specifically to MAb RG719 and also to raise the virus-neutralizing antibodies in rabbits. Vaccination with the HEP vaccine produced in Japan induced in humans and rabbits production of significant amounts of the antibodies which reacted with the 20-mer peptide.

Amino Acid Sequence↗
PubMed1995

[A clinical study of gastrointestinal flora in patients with, or without MRSA colonization in the upper-respiratory tract after introduction of preventive measures of hospital infection].

In early 1980's methicillin-resistant Staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in the A geriatric hospital MRSA infection was prevalent. To decrease nosocomial infections some active preventive measures against hospital infection were taken since Oct. 1991. After introduction of preventive measures of hospital infection in geriatric ward (190 beds) nosocomial bacteremia and pneumonia were markedly decreased in comparison to the episode number before introduction of prevention. However several patients with MRSA colonization were observed every month. The aim of this clinical study was to clear how frequent MRSA was isolated from the gastric juice and stool. Any MRSA was not observed in 63 cultured stool, but just one MRSA was isolated in patients with MRSA colonization. On the other hand gram-negative organisms, which were E. coli, P. aeruginosa, P. mirabilis etc., were frequently observed in cultured stool. In conclusion, we considered frequency of MRSA colonization in gastrointestinal space was not so high but rather very low.

Adult↗
PubMed1995

Does homozygosity advance the onset of dentatorubral-pallidoluysian atrophy?

We confirmed a homozygous type of relatively small expansion of CAG triplet repeats (57 repeats) in the short arm of chromosome 12 in a male patient with dentatorubral-pallidoluysian atrophy (DRPLA) by polymerase chain reaction. He showed early onset (age, 17 years) of DRPLA. There was good correlation of the age of onset with the number of triplet repeats. The homozygous state of the expansion of the triplet repeats was responsible for the early onset and severity of his DRPLA.

Adult↗
PubMed1995

An investigation of the effects of lifestyle on care-seeking behavior using data from health insurance claims.

To clarify the effects of lifestyle on care-seeking behavior, we conducted a questionnaire survey using Morimoto's 8 lifestyle factors and tabulated the medical evaluations at annual medical checkup of 1212 male white-collar employees of a company (aged 21-60 years in 1991), and then extracted the health insurance data for these subjects for the first half of 1992 from the health insurance-carrier computer system. The percentage of employees who visited medical facilities, the number of days of medical care, and the medical fees reported on the health insurance claims were chosen as indices of care-seeking behavior, and the relationship of each index to lifestyle and medical checkup data was examined. The health practice index (HPI), which was obtained by summing the scores for the 8 lifestyle factors was associated with the medical evaluation as expected, but was inversely correlated with the indices of care-seeking behavior. The percentage of employees who visited medical facilities, the number of the days of medical care, and the total medical fees were all higher for the subjects with high HPI scores than for those with low HPIs. Our findings are consistent with those of other researchers who have found an inverse relationship between tobacco smoking and health insurance claims, which has been attributed to the degree of consciousness of health. Compared to smokers, non-smokers have high consciousness of health and tend to consult a doctor more frequently, with resulting increased frequency of medical facility consultation and days of medical care, as well as medical fees. Lifestyle is an important aspect of physical and mental health status.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[A study of preventive medicine in relation to mental health among middle-management employees (Part 2)--effects of long working hours on lifestyles, perceived stress and working-life satisfaction among white-collar middle-management employees].

Recently, we have introduced the holistic method into health care of workers and aimed at improvement of Quality of Life (QOL). It has been made clear that primary prevention of diseases needs lifestyle appraisal. Therefore, we studied the daily working hours and the effects of long working hours on lifestyles, perceived stress and working-life satisfaction, which we used as a subjective index of Quality of Life (QOL), based on data obtained from a survey of 1,026 department chiefs and 2,902 section chiefs in 110 large companies in Japan in 1990. The results are summarized as follows. (1) The percentage of those working 10 hours per day was 41.6% for department chiefs and 40.4% for section chiefs, and for 11 or more working hours it was 24.1% in department chiefs and 30.9% in section chiefs. The younger both department and section chiefs, the longer their working hours. (2) Both department and section chiefs had a significant relationship between long working hours and poor sleeping habits, poor physical exercise, feeling busy, irregularity of daily life and irregularity of daily meals. The department chiefs had a significant relationship between long working hours and unbalanced nutrition or no hobbies. The section chiefs had a significant relationship between long working hours and drinking many cups of tea or coffee, taking a lot of salt or ill physical condition during the past six months.

Female↗
PubMed1995

[A survey of the inclinations of medical students towards becoming occupational physicians].

We conducted a survey to investigate medical students awareness of the activities of occupational physicians and their willingness to do postgraduate courses in this field. Those surveyed were fifth grade students in six universities in the Kinki district of Japan in 1993. In analyzing the responses of 368 eligible subjects, the response rate was 68.4% and the following results were obtained. 1) Only one of the 368 subjects expressed a desire to become an occupational physician after graduation, however 24.2% of those surveyed had considered becoming occupational physicians. More female students and, males over the age of 25, had considered becoming occupational physicians. Anxiety about a possible surplus of medical doctors in the near future was a factor that led them to consider becoming occupational physicians. 2) There were few negative responses concerning the activities of occupational physicians, even among those who had not considered becoming occupational physicians. 88.3% of those surveyed complained of a lack of information regarding postgraduate courses. 3) Responses were varied concerning conditions in the practice of occupational physicians. Those who had considered becoming occupational physicians were mostly concerned with the establishment of a system for the acceptance of occupational physicians in industry, while those who had not thought of becoming occupational physicians, considered practicing as occupational physicians as a sideline to regular clinic duties. 4) Having considered the above results and those of other researchers, we concluded that supplying more information related to the activities of occupational physicians and offering further postgraduate training programs in occupational medicine would encourage more medical students to become occupational physicians.

Career Choice↗
PubMed1995

Autonomic nervous disorder in motor neuron disease: a study of advanced stage patients.

Autonomic functions were studied in 10 respiratory-support patients with motor neuron disease (MND) at its most advanced stage by means of hemodynamic function tests. The mean duration of disease was 83.4 months (SD 28.0, range 50-140 months). All the patients in this study had lost their ability to breathe spontaneously and were ventilated by respirator. Hemodynamic function tests were performed in 8 out of 10 patients. These patients showed exaggerated sympathetic vasomotor reflexes, increased reflex hypertension and tachycardia in response to the cold pressor test and increased response to administration of adrenaline. However, the responses to both the Aschner eyeball pressure test and injection of atropine were normal, indicating normal parasympathetic nervous system function. Plasma and urine levels of norepinephrine, epinephrine and their metabolites were almost normal in all 10 patients, as were serum dopamine-beta-hydroxylase levels. In patients with the most advanced stage of MND, hyperfunction of the adrenergic sympathetic nervous system was observed, and this was considered to be a symptom characteristic of MND.

Aged↗
PubMed1995

The loss of in vivo activity of recombinant human erythropoietin by active oxygen species.

The effects of active oxygen species on the in vivo activity of recombinant human erythropoietin (EPO) treated by Fenton system, xanthine (X) plus xanthine oxidase (XO) system and hydrogen peroxide (H2O2) has been studied by means of counting the increase in number of hemolyser-resistant cells (HRCs) in EPO-injected mice. The results showed that both Fenton and X plus XO systems caused a significant reduction of the activity in proportion to the concentration of generated active oxygen species. Meanwhile, the treatment of EPO with H2O2 alone resulted in a relatively slight reduction of the activity. Electrophoretic studies on the structure of EPO revealed that its main protein band on sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) disappeared in proportion with the extent of exposure to active oxygen generating systems. Both Fenton and X plus XO systems caused a significant loss of fluorescence in the pyridylamino (PA-) sugar chain in proportion to the concentration of generated active oxygen species, and no degradation products in the sugar chain part of the PA-sugar chain were detected. This showed that aromatic groups in EPO were sensitive to attack by active oxygen species. These results provide evidence that hydroxyl radical and other active oxygen species have a potential to react with EPO, leading to a reduction of its in vivo activity.

Animals↗
PubMed1995

A clinical and neuroradiological study of X-linked hydrocephalus in Japan.

To clarify the clinicopathological features of X-linked hydrocephalus, the authors studied 30 affected males from 15 families. In utero ultrasonography, performed at 21 to 40 weeks of gestation, revealed 18 fetuses with hydrocephalus. Computerized tomography (CT) revealed bilateral enlargement of the lateral ventricle with preponderant dilation of the posterior horn. In five patients with complete magnetic resonance (MR) imaging data, the most specific finding was localized atrophy of the anterior vermian lobe. Other MR imaging findings included a large massa intermedia, flat corpora quadrigemina, a small brainstem, and diffuse hypoplasia of the cerebral white matter. In all cases, the corpus callosum was hypoplastic or aplastic. The aqueduct was patent in four of five cases. Asymmetrical reduction of the ventricular size and a rippled ventricular wall were characteristic postshunt CT findings. Progressive macrocephaly and symptoms due to increased intracranial pressure were ameliorated by the shunt; however, the neurological outcome was not improved by shunting. Of 14 patients who lived to be between 2 and 18 years of age, all are retarded. These results indicate that X-linked hydrocephalus is not a disease of simple ventriculomegaly due to aqueduct stenosis alone but involves other complicated central nervous system anomalies.

Abnormalities, Multiple↗
PubMed1995

[Identical male twins showing progression from hypertrophic cardiomyopathy to dilated cardiomyopathy-like features].

Twenty-three-year-old identical male twins with hypertrophic cardiomyopathy which progressed into the dilated phase are reported. The younger brothers first presented at age 16 with an abnormal electrocardiogram. Hypertrophic nonobstructive cardiomyopathy with an asymmetric septal hypertrophy was diagnosed. He was treated with beta-blocker, but he stopped taking the drug as he had no symptoms at that time. He presented again at age 21 years with symptoms of apparent congestive heart failure. Echocardiography showed marked dilatation of the left ventricle with thin wall which was compatible with dilated cardiomyopathy. The elder brother presented with an initial echocardiogram showing systolic anterior movement of the mitral valve without asymmetric septal hypertrophy. He presented again with his brother aged 21 years when his echocardiogram showed slight dilatation of the left ventricle, although he did not complain of cardiac symptoms. These identical twins are the first reported cases of hypertrophic cardiomyopathy progressing to the deteriorated dilated phase.

Adult↗
PubMed1995

[Primary nasopharyngeal lymphoma with CD3- and CD56+ phenotype].

A 73-year-old man was admitted to our hospital with nasal hemorrhage and high grade fever on Aug, 1992. Physical examination revealed a tumor in the nasopharyngeal cavity, generalized skin eruptions and three tumors on different subcutaneous lesions, splenomegaly 2 cm below the costal margin, and the enlargement of the right cervical and axillary lymph nodes. Biopsy of the nasopharyngeal and cutaneous tumor disclosed non-Hodgkin's lymphoma (WF: Diffuse small cleaved). Peripheral blood examination showed a WBC of 4,800/microliters with 10% blastoid cells. Bone marrow examination showed 60% blastoid cells which frequently appeared a hand mirror configuration had no azurophilic granules in the cytoplasm. Flow cytometic analysis of these cells in the bone marrow showed that they expressed CD56 (NKH-1) and Ia but not expressed T-cell antigens as well as B-cell antigens and myeloid cell antigens. Phenotype of subcutaneous tumor biopsy cells was similar to that of blastoid cells in the bone marrow. T-cell receptor gene (TCR beta and gamma) rearrangements in blastoid cells were not found. The patient was treated with local radiotherapy to nasopharyngeal and skin tumors, followed by chemotherapy. The patient died of complication with pulmonary bleeding due to DIC. These results suggested that this nasopharyngeal lymphoma derived from NK cell.

Aged↗