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Biomedical subjects

M Shoji

Publications and source records attributed to M Shoji.

At least 253 records · Page 14Linked to original sources
PubMed1991

Secondary deposition of beta amyloid within extracellular neurofibrillary tangles in Alzheimer-type dementia.

The hippocampal areas of 34 autopsy specimen brains from aged demented and nondemented subjects were examined using double staining of Bodian and beta protein. In 18 cases (75.5 +/- 7.4 years old), none of the extracellular neurofibrillary tangles (E-NFTs) were immunoreactive with beta protein. In 16 cases (82.9 +/- 5.4 years old), the minority of E-NFTs were immunoreactive with beta-protein antiserum. These beta-immunoreactive E-NFTs frequently appeared in the areas having senile plaques, while they were not observed in the area lacking beta-immunoreactive senile plaques. The ultrastructure of beta-immunoreactive E-NFTs revealed that they consisted of extracellular amyloid fibrils, extracellularly located bundles of paired helical filaments, astroglial processes and degenerating neurites. These findings suggest that the beta immunoreactivity of E-NFTs comes from secondary deposition of amyloid fibrils.

Aged↗
PubMed1991

[Pulsatile release of gonadotropins in athletic women].

In athletic women menstrual disorders such as luteal insufficiency, oligomenorrhea and amenorrhea are often seen. It has been suggested that such disorders may be related to hypothalamic-pituitary axis insufficiency caused by physical activity. To investigate the mechanism by which the disorder is promoted, episodic gonadotropin secretion was studied in 10 athletic women (normal ovulatory, 5; short luteal, 5) and 6 non-athletic controls. In the early follicular phase of the menstrual cycle, blood samples were obtained through an indwelling venous catheter at 15-minute intervals for 4 hours. The concentrations of luteinizing hormone (LH) and follicle-stimulating hormones (FSH) were measured by radioimmunoassay. The mean LH and FSH concentrations in the athletic groups were lower than those in the control group. LH pulse frequencies in the short luteal group were 2.8 +/- 0.2 times/four hours (mean +/- standard error) and decreased compared with that of the control group (3.7 +/- 0.2 times/four hours; p less than 0.001). The LH pulse amplitudes of all three groups were similar. Pulsatile FSH secretion was also observed in all the women. Dynamism of FSH was the same as that of LH except for low pulse amplitude in the athletic groups. These data suggest that hypothalamic-pituitary axis insufficiency, especially of hypothalamic origin may be caused by athletic activity.

Adult↗
PubMed1990

Amyloid beta/A4 protein precursor is bound to neurofibrillary tangles in Alzheimer-type dementia.

Localization of amyloid beta/A4 protein precursor (APP) in Alzheimer's neurofibrillary tangles (NFT) was examined immunohistochemically. Antiserum directed to N-terminal of APP intensely labeled intracellular NFT and some neuropil threads. The NFT, extracted from Alzheimer brains by detergent treatments, were also immunoreactive with this antiserum. Antisera to other parts of APP labeled NFT after the formic acid pretreatment. However, Western blot analysis of NFT demonstrated no immunoreactive bands with APP antiserum. These findings suggest that APP is a minor component of the NFT.

Adult↗
PubMed1990

The amyloid beta-protein precursor is localized in smooth muscle cells of leptomeningeal vessels.

We examined leptomeningeal vessels using 2 different antisera which recognized both terminal ends of amyloid beta-protein precursor (APP). Both antisera recognized a 120-kDa protein from leptomeningeal vessels. Immunocytochemistry showed that APP was localized in the smooth muscle cells of leptomeningeal vessels. These results indicated that the smooth muscle cells of leptomeningeal vessels contained full-length native APP, and that the cerebrovascular amyloid in the leptomeningeal vessels was derived from this APP.

Aged↗
PubMed1990

Inhibition of protein kinase C, (sodium plus potassium)-activated adenosine triphosphatase, and sodium pump by synthetic phospholipid analogues.

The effects and modes of action of certain antineoplastic phospholipid analogues (racemic 1-O-octadecyl-2-O-methyl glycero-3-phosphocholine, BM 41.440, JH-1, CV-3988, and HePC) on (sodium plus potassium)-activated adenosine triphosphatase (Na,K-ATPase) and sodium pump activities were investigated. Inhibition of Na,K-ATPase in purified rat brain synaptosomal membranes by these lipids, in contrast to ouabain, was subject to membrane surface dilution and unaffected by whether the reaction was started with KCl, NaCl, or ATP. Kinetic analysis indicated that the analogues, again dissimilar to ouabain, were likely to interact directly or indirectly with sodium-binding sites of Na,K-ATPase located at the intracellular surface of the plasma membrane, a conclusion also supported by studies using the inside-out vesicles of human erythrocyte membranes. The studies also showed that ouabain (but not the lipids) increased the affinity constant of Na,K-ATPase for K+, whereas the lipids (but not ouabain) increased that for Na+. The lipids also inhibited 86Rb uptake by intact human leukemia HL60 cells at potencies quite comparable to those seen for inhibition of purified protein kinase C or Na,K-ATPase. It is suggested that Na,K-ATPase (sodium pump) might represent a hitherto unrecognized site of action for the lipid analogues, and that the antineoplastic effects of the agents might be due to, in part, inhibition of both protein kinase C and Na,K-ATPase and perhaps other membrane-associated enzymes.

Biological Transport, Active↗
PubMed1990

Amyloid beta-protein precursor accumulates in dystrophic neurites of senile plaques in Alzheimer-type dementia.

We raised two rabbit antisera against synthetic peptides corresponding to the carboxyl- and amino-terminal regions of the predicted amyloid beta-protein precursor (APP). Both antisera recognized the same 106-135 kDa proteins of human brain extract by immunoblot analysis. Immunocytochemical studies showed that these antisera both reacted with the same dystrophic neurites within the senile plaques of Alzheimer brains. These results indicated that APP accumulated in the dystrophic neurites of the senile plaques.

Aged↗
PubMed1990

Spontaneous oscillation of artificial membrane: equivalence in effects of temperature and volatile anesthetic.

Oscillatory phenomenon at an oil-water interface in the presence of hexadecyltrimethylammonium bromide (CTAB) has been studied. The oscillation was attributable to successive formation and destruction of surfactant monolayer. According to the temperature elevation, the frequency of the electrical oscillation increased whereas the amplitude decreased. Addition of diethylether increased the frequency and decreased the amplitude. These effects of temperature and anesthetic were analyzed by the theory of the "N"-shaped relationship between surface-pressure and surface-concentration of the surfactant.

Cetrimonium↗
PubMed1990

Immunoelectron microscopic localization of amyloid beta protein in the diffuse plaques of Alzheimer-type dementia.

We examined the ultrastructural localization of beta protein in diffuse plaques of Alzheimer brain by indirect immunoperoxidase technique. Intense immunoreaction products, scattered sporadically in the diffuse plaques, were located on small bundles of several amyloid fibrils and/or amorphous materials between amyloid-related cell processes (ARCP). Deposits of beta protein were also seen on parts of the cell membrane of ARCP, suggesting the importance of ARCP in plaque amyloid deposits.

Aged↗
PubMed1990

Alpha 1-antichymotrypsin as a possible biochemical marker for Alzheimer-type dementia.

We measured serum alpha 1-antichymotrypsin levels in 38 patients with Alzheimer-type dementia, 89 control subjects, 2 subjects with Down's syndrome, 20 with vascular dementia, 18 with Parkinson's disease, 14 with spinocerebellar degeneration, 15 with cerebrovascular disease without dementia, and 14 with Duchenne muscular dystrophy. Cerebrospinal fluid (CSF) levels of alpha 1-antichymotrypsin were also measured in 15 patients with Alzheimer-type dementia, 26 control subjects, 6 with vascular dementia, 7 with cerebrovascular disorder, and 11 with degenerative disorders. In control subjects, there were no age-related changes or sex differences. Serum and CSF levels were significantly and specifically higher in patients with Alzheimer-type dementia than in other subjects (serum, p less than 0.001; CSF, p less than 0.05). Serum levels of alpha 1-antichymotrypsin were significantly elevated in the early stage of Alzheimer-type dementia, whereas there was no definite correlation between serum levels and the degree of dementia. CSF levels of alpha 1-antichymotrypsin tended to parallel the severity of dementia. Serum levels were not correlated with CSF levels. These data indicate that serum and CSF levels of alpha 1-antichymotrypsin might be independently upregulated in Alzheimer-type dementia. We concluded that the measurement of serum levels of alpha 1-antichymotrypsin could be useful as a screening marker for Alzheimer-type dementia. In addition, CSF levels also could be a useful marker for Alzheimer-type dementia, because they might reflect the state of dementia.

Age Factors↗
PubMed1990

Ultrastructure of the neuropil threads in the Alzheimer brain: their dendritic origin and accumulation in the senile plaques.

Thread-like structures immunoreactive with paired helical filaments and tau antisera were demonstrated as mesh-works in the neocortices of five brains with Alzheimer-type dementia, but not in those of five normal aged control brains. The ultrastructure of the threads was examined using paired routine electron microscopic ultrathin sections and adjacent 0.4-micron-thick semithin sections, immunostained for beta protein. Outside the beta protein-positive senile plaques, neuropil threads appeared sporadically as small slender neurites, containing either regularly constricted or straight filaments. These neurites often showed dendritic profiles. Similar threads were also seen within the senile plaques. The threads were accumulated in amyloid fibril-rich primitive plaques, but not in amyloid fibril-poor diffuse plaques. The presence of these threads was closely associated with neurofibrillary tangle formation. Our findings suggest that wide-spread change of the neuropil neurites, neuropil threads or curly fibers, both outside and inside of the senile plaques are dendritic in origin and play an important role in the clinical manifestation of dementia.

Aged↗
PubMed1990

Axonal swellings in the corticospinal tracts in amyotrophic lateral sclerosis.

In 2 of 16 cases with sporadic amyotrophic lateral sclerosis (ALS) large numbers of axonal swellings were observed in the corticospinal tracts over a region extending from the posterior limbs of internal capsules to the bulbar pyramids. On electron microscopy, these axonal swellings were seen to consist of accumulations of neurofilaments and altered neuronal organelles (mitochondria and secondary lysosomes). Their morphology differed from the spheroids seen in the anterior horn in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1990

Depression in members of a new religious sect in Japan.

We investigated 226 people belonging to a regional church of a new religious sect (hereinafter referred to as religious group) and 899 ordinary people living in the rural area near this church (hereinafter referred to as nonreligious group) with a questionnaire using Zung's Self-Rating Depression Scale (SDS). In males ranging in age from 40 to 69, the mean scores of 7 SDS items out of 20 were significantly higher in the religious group than in the nonreligious group. Males at the age of 70 or older in both groups, however, did not show any significant difference in these items. It suggests that the religious affiliation exerted mentally good effects on the older male members.

Adaptation, Psychological↗
PubMed1990

Syntheses and biological activities of renin inhibitors containing statine analogues.

Syntheses and biological activities of dipeptide renin inhibitors that contain statine analogues are described. The key steps of the synthetic approach to dipeptide renin inhibitors are the asymmetric synthesis of 2(R)-substituted-3-aminocarbonylpropionic acids and the diastereoselective syntheses of (3S,4S)-statine analogues. These inhibitors (2,14-40) inhibited human renin in the 3-140 nM range. Inhibitor ES 6864 (2) was found to be a highly potent inhibitor of human renin (IC50: 4.6 x 10(-9) M) and showed high enzyme specificity. Oral administration of ES 6864 at 3 mg/kg to conscious, sodium-depleted marmosets inhibited plasma renin activity (PRA) more than 80% after 1 h.

Amino Acids↗
PubMed1990

Effects of central osmotic stimulation on vasopressin and enkephalin release into the blood and cerebrospinal fluid and blood pressure.

To assess the central effect of hypertonic NaCl on the release of vasopressin (AVP) and methionine enkephalin-like substances into the blood and cerebrospinal fluid, and on blood pressure, ventriculocisternal perfusion (0.25 ml/min, 60 min) was performed in anesthetized dogs with artificial cerebrospinal fluid (CSF), either isotonic (300 mosmol/kg) or hypertonic (600 and 1200 mosmol/kg). The effect of central administration of a V1-AVP antagonist on the central osmotic challenge was also studied. In dogs, given 600 mosmol/kg, CSF osmolality increased with a concomitant rise in mean arterial pressure and plasma AVP concentrations. Plasma osmolality, heart rate, CSF AVP and plasma and CSF methionine enkephalin-like substances showed no significant change. In dogs, given 1200 mosmol/kg, the CSF osmolality increase was accompanied by a rise in mean arterial pressure, heart rate, plasma AVP and CSF AVP. Plasma osmolality and plasma and CSF methionine-enkephalin-like substances did not change significantly. A V1-AVP antagonist given centrally attenuated the rise in mean arterial pressure induced by osmotic challenge. In dogs, given 300 mosmol/kg, no parameters changed significantly except for a gradual fall in heart rate. These results suggest that central osmotic stimulation by hypertonic NaCl increases blood pressure, heart rate and the release of AVP, but not methionine enkephalin-like substances, into the blood and CSF, and a V1-blocker given centrally attenuates the pressor response.

Animals↗
PubMed1990

[Mental health in software engineers. I. Frequency of mental complaints, physical complaints and psychiatric disorders].

This study examined the physical complaints, mental complaints and psychiatric disorders in software engineers. Subjects were 101 male software engineers. They were evaluated by a semistructured interview. Psychiatric diagnosis was based on DSM-III (Diagnostic and Statistical Manual of Mental Disorders, third edition). The results are summarized as follows: 1) Physical complaints were observed in 68% of the subjects with 25% of the subjects complaining of physical ill-health. This study showed that 12% of the subjects had hypertension, 12%, gastritis or gastro-duodenal ulcer, 14%, allergic disease, and 19% miscellaneous diseases. 2) Of the subjects 62% had mental complaints and 31% mental ill-health. Depressive symptom was the most frequent mental complaint with 32% of the subjects diagnosed as DSM-III. The common diagnoses were adjustment disorders (19%), major affective disorders (6%), psychological factors affecting physical condition (5%) and dysthymic disorder (3%). Only one subject sought professional help from a psychiatrist for relief of mental complaints. The data suggest the severity of mental ill health in software engineers, but methodological limitations preclude a firm conclusion at this time. Further studies should be made on the mental health state in software engineers.

Adult↗
PubMed1990

[Mental health in software engineers. II. Classification of occupational stressors, and relationship between occupational stressors and psychiatric disorders].

Occupational stressors and psychiatric disorders were studied in a sample of 101 male software engineers. Psychiatric diagnosis was based on DSM-III (Diagnostic and Statistical Manual of Mental Disorders, Third Edition). The results can be summarized as follows: 1) More than 30% of the subjects were not satisfied with their work. 2) Occupational stressors ascertained in the interview could be classified into "quantity of job," "quality of job," "role in organization," "relations with others," "work conditions," "career development," "reward," "organizational structure and climate," "low social support," and "lack of decision making." "quality of job" (35%), "quantity of job" (30%), and "role in organization" (33%) were the most common stressors for the subjects. 3) Among the occupational stressors, only "quantity of job" was significantly related to psychiatric disorders (p less than 0.05). The results suggest that many software engineers are not satisfied with their work and that "quantity of job" has the greatest influence on their mental health. Some measures should be taken to avoid potential health hazards, for the research findings indicate a relationship between occupational stressors and mental health in software engineers.

Adult↗