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Biomedical subjects

M Sakai

Publications and source records attributed to M Sakai.

At least 757 records · Page 42Linked to original sources
PubMed1984

[A study on prolapse of the mitral valve in autopsy-proved papillary muscle dysfunction].

Echocardiographic studies have recently documented high incidence of mitral valve prolapse in cases with papillary muscle dysfunction (PMD). However, any pathologic evidence has not been yet described. To evaluate the incidence and the degree of morphologic prolapse of the mitral valve, we examined 76 cases of mitral regurgitation which were pathologically proved to have PMD among 3,000 consecutive autopsy cases over 60 years of age. The morphologic evidence of "mitral valve prolapse" was defined as overshooting of the mitral leaflet into the left atrium beyond the degree of normal hooding. Papillary muscle dysfunction was classified into three types; Type A due to old myocardial infarction, Type B due to acute myocardial infarction, and Type C induced by other factors such as cardiomyopathies. The following results were obtained: Morphologic "mitral valve prolapse" was found in 19 among the 76 cases (25%) of PMD, but marked "prolapse" was found in only one case. The incidence of morphologic "prolapse" did not show any difference among the types of PMD (cf. Fig. 1). The site of "prolapse" was mainly in the region of posteromedial commissure of the mitral valve. Echocardiographic study of 39 cases with PMD showed mitral valve prolapse in only two cases who belonged to the eight cases having morphologic "mitral valve prolapse". This study suggests that prolapse formation of the mitral valve secondary to PMD can be differentiated morphologically from those following primary myxomatous degeneration of the mitral leaflets as observed in cases with MVP.

Aged↗
PubMed1984

[A clinicopathologic study of valvular aortic stenosis in the aged].

To evaluate the usefulness of phonocardiography (PCG), carotid pulse recording (CAG) and echocardiography (UCG) used in diagnosing valvular aortic stenosis (AS) in the aged, we performed a clinicopathologic study of 23 autopsied patients with pathological evidence of aortic stenosis (AS). There were eight men and 15 women, whose ages averaged 82 years. PCG and CAG were available in 15 patients, and UCG was available in 13 patients. We classified the subjects into three groups; Group A with calcified AS, Group B with bicuspid AS and Group C with rheumatic AS. The following results were obtained. There were 12 patients in Group A, four in Group B and seven in Group C. Patients in Group A were older than those in Group B or C (A; 84-year-old, B; 80-year-old, C; 79-year-old on the average). The mean heart weight of Group A was less than that of Group B or C (A; 345 g, B; 453 g, C; 486 g). Congestive heart failure was more frequent in Groups B and C than in Group A. The fourth heart sound was recorded on the PCG in nine of 11 patients without atrial fibrillation, but there was no difference in incidence among the three groups. An ejection systolic murmur was recorded in all cases and a diastolic murmur of aortic regurgitation in 10. No patients had shudder formation on the CAG. The T-time tended to be prolonged in AS, especially in Groups B and C. The peak of the systolic murmur tended to be late in systole in Groups B and C. A1-peak/LVET was significantly increased in Groups B and C (A; 0.38, B; 0.51, C; 0.47). The decreased amplitude of aortic valvular opening (AVO) and the dense diastolic echo of the aortic valve were observed in all AS cases. The AVO of Group A was significantly less in amplitude than that of Group C (A; 3.6, C; 6.4). Thus, we could differentiate Group A from Groups B and C by various non-invasive techniques. These findings may be attributed to the different anatomic features of the aortic valves among these three groups.

Aged↗
PubMed1984

[A case of advanced gastric cancer associated with smouldering adult T-cell leukemia (ATL)].

A 43-year-old man was admitted to our clinic because of a 2-month history of anorexia, general fatigue and an upper abdominal mass. Upper GI series and endoscopic examination revealed Borrmann IV-type gastric cancer. The histologic diagnosis was undifferentiated adenocarcinoma. His peripheral blood contained approximately 3% atypical lymphocytes. These lymphocytes were identified to be ATL-cell based on E-rosette formation assays and anti-ATL associated antigen-antibody tests. Although the patient had no typical ATL-symptoms, we made a diagnosis of double cancer, i.e. gastric cancer and smouldering ATL. This is the first reported Japanese case of gastric cancer associated with smouldering ATL relationship between gastric carcinoma and other malignant diseases, especially ATL, is discussed.

Adenocarcinoma↗
PubMed1983

Columnar aggregation of prefrontal and anterior cingulate cortical cells projecting to the thalamic mediodorsal nucleus in the monkey.

The columnar arrangement of the prefrontal and anterior cingulate cortex cells that project to the thalamic mediodorsal (MD) nucleus in rhesus and Formosan monkeys was studied by injecting horseradish peroxidase into the MD nucleus. Labelled cells appeared ipsilaterally in layers V and VI in the dorsolateral, medial, and orbital prefrontal cortex, and in layer VI in the anterior cingulate cortex. Labelled cells were aligned in the radially oriented cords of neurons and grouped into clusters, 25-200 microns wide, thus forming columns. Radial cellular cords with no labelled cells were interspersed between the labelled radial cords.

Animals↗
PubMed1983

A monoclonal antibody against catalytic subunits of acetylcholinesterase in the electric organ of an electric ray, Narke japonica.

A hybridoma cell line secreting a monoclonal antibody against catalytic subunits of acetylcholinesterase in the electric organ of Narke japonica has been obtained by using a mouse immunized with the nerve terminal membranes prepared from the electric organ of Narke japonica. This monoclonal antibody (Nj-501) reacted with asymmetric, low salt-soluble and detergent-soluble forms of acetylcholinesterase of the electric organ of Narke japonica. Immunoblot analysis showed that the catalytic subunits of the asymmetric, low salt-soluble and detergent-soluble forms of acetylcholinesterase were polypeptides of molecular weight (Mr) 70K, 70K / 66K and 66K, respectively. Nj-501 markedly inhibited the activity of all these forms of acetylcholinesterase.

Acetylcholinesterase↗
PubMed1983

beta-Galactosidase-neuraminidase deficiency (galactosialidosis): clinical, pathological, and enzymatic studies in a postmortem case.

Three male siblings in a Japanese family were affected with beta-galactosidase-neuraminidase deficiency (galactosialidosis). One patient died at 45 years of age, and postmortem liver and brain tissues were studied enzymatically. The residual activity of neuraminidase was relatively high in these tissues. Neuraminidase activity did not change in the tissues after repeated freezing and thawing of the homogenates, whereas this enzyme in control tissues lost 30 to 60% of its activity. There was a profound deficiency of beta-galactosidase in the tissues of the patient. Michaelis constant, pH profiles, and cryostability were identical for the patient and control patients. Cathepsin B was moderately increased in activity in the patient's tissues.

Adult↗
PubMed1983

Neuropathological findings of an autopsy case of adult beta-galactosidase and neuraminidase deficiency.

An autopsy case of a Japanese male with familial beta-galactosidase and neuraminidase deficiency is reported. The clinical picture was characterized by adult onset, a gargoyle-like face, cerebellar ataxia, myoclonus, convulsions, retinal degeneration and cortical blindness. Histopathologically, most neurons seemed to have become degenerated in the whole cerebral cortex. Moreover, the calcarine cortex appeared spongy with depopulation of nerve cells. Stuffed neurons or neuronal storage changes were found throughout the brain, especially in the motor nuclei of the spinal cord and brain stem. The inclusions in the stuffed neurons revealed various profiles on the electron microscope. They were composed of membranous lamellar and/or multilamellar structures, often accompanying vacuoles and reminiscent of lipofuscin-like profiles.

Age Factors↗
PubMed1983

The role of crossed and uncrossed optic pathways mediating black-white discrimination in rats with one eye enucleated at birth.

It has been reported that rats with one eye enucleated at birth (OEB) are able to relearn a black-white discrimination task originally learned with both the visual cortices intact faster than rats monocularly enucleated at three months of age (OET) when relearning is made after the visual cortex contralateral to the remaining eye is destroyed. Two experiments examined the hypothesis that functional enhancement of uncrossed optic pathways produced by monocular enucleation at birth might be the sole factor to produce such a phenomenon. The results showed that faster relearning in OEBs could not be totally explained by the hypothesis, and suggest that only when (1) there is a learning effect in the visual cortex ipsilateral to the remaining eye produced by interaction of visual information through the callosal fibers with an increased amount of information through uncrossed optic pathways during original learning and (2) relearning is mediated by enhanced functioning of uncrossed optic pathways, would such phenomenon be produced.

Animals↗
PubMed1983

Primary structures of human alpha-fetoprotein and its mRNA.

DNA complementary to human alpha-fetoprotein (AFP)mRNA was cloned in the plasmid pBR322. Analysis of three overlapping cDNA clones revealed most of the nucleotide sequence of AFP mRNA, and the remaining nucleotides at the 5' end of the mRNA were elucidated from a cloned genomic DNA fragment. The amino acid sequence was deduced from the nucleotide sequence, which revealed 19 amino acids in the signal sequence and 590 amino acids in mature AFP. There are 15 regularly spaced disulfide bridges, which generate a folding structure having three repeating domains. There is one potential N-glycosylation site, Asn-Phe-Thr, in the amino acid sequence. In comparison with mouse AFP, 66% of the amino acid sequence was conserved, with the highest identity (72%) in domain 3, followed by domain 2 (67%) and domain 1 (59%). In comparison with human albumin, a 39% conservation of primary structure was found. Again, the similarity was the highest in domain 3 and the lowest in domain 1. Human AFP and human albumin are similar in overall structure, but certain parts of the molecules differ significantly in their predicted secondary structure.

Amino Acid Sequence↗
PubMed1983

Activation of potassium transport induced by secretagogues in superfused submaxillary gland segments of rat and mouse.

In order to investigate the actions of acetylcholine (ACh), catecholamines and substance P on K transport in the submaxillary gland, measurements of net K flux to and from the gland tissue using flame photometry, Na efflux from the tissue using radioactive 22Na, and membrane potential and input resistance using micro-electrodes were carried out on isolated superfused segments of rat and mouse submaxillary glands. ACh (5.5 X 10(-8) to 5.5 X 10(-4) M), phenylephrine (5 X 10(-7) to 5 X 10(-4) M) or substance P (10(-9) to 10(-5) M) stimulation for 5 min induced a transient K release followed by a small K uptake after the cessation of stimulation. The K release was markedly enhanced by the simultaneous addition of ouabain (10(-3) M). On the other hand, isoprenaline (2.5 X 10(-9) to 2.5 X 10(-5) M) induced a transient K uptake without any preceding K release. The K uptake was completely blocked by the addition of ouabain. Noradrenaline induced only K uptake at a low concentration (3 X 10(-7) M), but induced transient K release followed by marked K uptake at higher concentrations (3 X 10(-6) to 3 X 10(-4) M). The K release induced by noradrenaline was suppressed by the addition of phentolamine (10(-5) M), while the K uptake was suppressed by propranolol (5 X 10(-6) M). The K release induced by ACh, phenylephrine, noradrenaline or substance P was severely reduced by Ca omission from the superfusing solution and restored by the re-admission of Ca. The isoprenaline- or noradrenaline-induced K uptake was, however, little affected by Ca omission. Application of isoprenaline (2.5 X 10(-6) M) induced an increase in 22 Na efflux. The increase in 22Na efflux was completely abolished in the presence of ouabain. Local application to the tissue bath of isoprenaline (4.7 X 10(-13) to 4.7 X 10(-12) mole) or noradrenaline (5.7 X 10(-12) to 5.7 X 10(-11) mole) in the presence of phentolamine (10(-5) M) induced membrane hyperpolarization without any appreciable change in input resistance. The hyperpolarization was abolished in the presence of ouabain (10(-3) M) or propranolol (5 X 10(-6) M) or in a K-free or low Na solution. Higher doses of both agonists, however, induced depolarization or biphasic responses (initial depolarization followed by hyperpolarization). The depolarizations were accompanied by a moderate reduction in input resistance. It is concluded that in the rat and mouse submaxillary gland acinar cells cholinergic, alpha-adrenergic or substance P stimulation causes K release (and perhaps Na uptake) resulting in activation of the Na-K pump, while beta-adrenergic receptor stimulation might directly activate the Na-K pump resulting in K uptake, or might cause Na uptake resulting in activation of the Na-K pump.

Acetylcholine↗
PubMed1983

Cyclic cytoplasmic activity of non-nucleate egg fragments of Xenopus controls the morphology of injected sperms.

Triton X-100-treated sperms were injected into non-nucleate egg fragments of Xenopus laevis to determine whether the structure of the injected sperm nucleus is affected by the cyclic activity of the cytoplasm. Swollen vesicular nuclei were very frequently observed when the sperms were injected and incubated during the 'rounding-up' phase of the recipient fragment, whereas no such structures were found when they were incubated during the 'relaxing' phase.

Animals↗