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Biomedical subjects

A Hayashi

Publications and source records attributed to A Hayashi.

At least 235 records · Page 13Linked to original sources
PubMed1995

Accumulation of tropoelastin by a short-term ascorbic acid treatment in the culture medium of aortic smooth muscle cells in vitro.

Treatment of cultured smooth muscle cells with ascorbic acid resulted in an accumulation of tropoelastin in the culture medium in dose-dependent and exposure time-dependent manner under the condition in which collagen synthesis was stimulated 2-fold. The steady-state level of elastin mRNA was essentially unchanged, whereas collagen mRNA content increased 2-fold by ascorbic acid treatment. Newly synthesized tropoelastin was hydroxylated in the presence of ascorbic acid but was underhydroxylated in a scorbutic condition. Short pulse experiments showed that the secretion rate of tropoelastin was unaltered by ascorbic acid treatment. Pulse-chase experiment demonstrated that the level of fully hydroxylated tropoelastin in the medium of ascorbate-treated cells was greater than that of under-hydroxylated tropoelastin. These results indicate that accumulation of tropoelastin in the medium by ascorbic acid is related to an increased stability of hydroxylated tropoelastin and/or its impaired incorporation into insoluble elastin.

Actins↗
PubMed1995

Studies of temporomandibular joint sounds Part 3. The clinical usefulness of TMJ Doppler.

Doppler auscultation as applied to internal derangements of the TMJ has been developed in recent years. Possible clinical use of TMJ Doppler auscultation was examined by separating the signals into their spectral components, and comparing the results with those of the conventional sound amplification system (CSAS). Observing frequency component changes with time, similar observations were made using CSAS and TMJ Doppler. However, noises found in TMJ Doppler sonograms were markedly reduced in comparison with those found using CSAS. Ultrasonic waves have high directivity, and pass through soft tissue and fluid; however they have difficulty passing through air, and this may decrease the recording noise. TMJ Doppler can be applied to record movements of the condyle because changes in the receiving frequency indicate the movement of an observed object with precision.

Adult↗
PubMed1995

Concentric fibrosis and cellular infiltration around bile ducts induced by graft-versus-host reaction in mice: a role of CD8+ cells.

We report in this paper on obvious fibrotic lesions in the liver of mice undergoing specified graft-versus-host reaction (GVHR). B6 CD8+ splenocytes were transferred into (bm 12 x bm 1)F1 mice to induce GVHR. Recipient mice had been thymectomized and administrated with anti-CD8 monoclonal antibody (mAb) to deplete CD8+ cells from the hosts. Two weeks after the mAb administration, recipient mice were injected with B6 CD8+ cells and sacrificed further two or four weeks later for analyzing hepatic lesions histopathologically. Light microscopic analyses revealed the presence of concentric fibrosis around both small and large duct levels and the infiltration of mononuclear cells into portal areas. Focal necrosis of hepatocytes was also detected electron-microscopically. These findings suggest that CD8+ T lymphocytes might play an important role in the induction of fibrotic lesions in the liver.

Animals↗
PubMed1995

[Marked clinical improvement by plasmapheresis in a patient with stiff-man syndrome: a case with a negative anti-GAD antibody].

We described a 56-year-old man with stiff-man syndrome, who was markedly improved after plasmapheresis therapy. He had a 12-year history of progressive painful stiffness of his back and limbs, muscle cramps and difficulty in walking. He had been taking oral diazepam and prednisolone. On examination the abdominal and paraspinal muscles and limbs were continuously contracting, confirmed by surface and needle electromyography. Antibodies against glutamic acid decarboxylase (GAD) and pancreatic islet cells in the serum were negative, but antinuclear antibody and anti-smooth-muscle antibody were present. The patient underwent a course of 4 double filtration plasma exchanges of 3,000 ml each in an 8-day period. Plasmapheresis resulted in marked clinical improvement. The disappearance of muscular cramps and a reduction of stiffness occurred within 24 hours after the first plasmapheresis, and he was able to walk unassisted. The patient's subjective improvement continued over 4 months after the plasma exchange. This case provides additional evidence of the autoimmune mechanism of stiff-man syndrome. Plasmapheresis is one choice in the management for stiff-man syndrome.

Antibodies, Antinuclear↗
PubMed1995

[A case of HLA-DR2, DQw1 negative post-traumatic narcolepsy].

We reported a case of a 24-year-old man who had frequent sleep attacks beginning 4 years after a head trauma. He showed frequent episodes of excessive daytime sleepiness and cataplexy which were triggered by emotional excitement. He also complained of sleep paralysis and hypnagogic hallucination. An overnight polysomnography revealed the sleep onset REM stage as typically observed in narcoleptic patients. The HLA typing was negative for DR2 and DQw1. He was diagnosed as having HLA-DR2 and DQw1 negative-post-traumatic narcolepsy. Peroral pemoline suppressed excessive daytime sleepiness, sleep paralysis and hypnagogic hallucination with dramatic relief of cataplectic attacks by the addition of imipramine. It has been reported that more than 90% of narcoleptic patients are HLA-DR2 and-DQw1 positive. About 10% of the narcolepsy patients were regarded as symptomatic due to brain tumors, cerebrovascular disorders, head trauma, multiple sclerosis, encephalitis and so on, which mainly affect the brainstem or diencephalon. Thus far, narcolepsy is considered to develop depending on both the genetic background including HLA types, and exogenous factors. According to reported cases with narcolepsy, sporadic cases were HLA-DR2 positive even more frequently than familial cases. To date, however, there have been only three previous reports of a symptomatic narcolepsy patient without association of HLA-DR2 and DQw1. In conclusion, the present report suggests that typical symptomatic narcolepsy could be HLA-DR2 or DQw1 negative.

Adult↗
PubMed1994

Minoxidil stimulates elastin expression in aortic smooth muscle cells.

Minoxidil was found to inhibit the proliferation of smooth muscle cells in the proliferating phase, but not in the quiescent phase. Treatment of proliferating or quiescent cells with minoxidil resulted in a dose- and time-dependent stimulation of elastin synthesis specifically. Maximum stimulation (fourfold) occurred in cells treated with 1 mM minoxidil for 48 h. The stimulation of elastin synthesis was accompanied by a proportional increase in elastin mRNA level, and it was partially prevented by a K+ channel blocker (tetraethylammonium) and completely prevented by high K+ salt (0.1 M). Minoxidil had no significant effect on the extent of prolyl hydroxylation in newly synthesized elastin. These results indicate that minoxidil stimulates elastin synthesis at a pretranslational level by a mechanism unrelated to cell proliferation but one that may involve K+ efflux. As a pharmacological agent capable of stimulating elastin expression, minoxidil would be a useful drug for the treatment of abnormal elastin metabolism.

Actins↗
PubMed1994

A novel gelatinolytic enzyme secreted by amelanotic cells isolated from B16 melanoma cell line.

Mouse B16 melanoma cells are of heterogenous populations and consist of melanotic and amelanotic cells. Two clones, M3 (melanotic) and A7 (amelanotic), were screened from B16 melanoma cells using a microscope, and gelatinolytic activities in these clones were studied with zymography. Gelatinolytic enzyme was found in the cultured medium of A7 cells, but not in M3 cells. The enzymes with apparent molecular weights of 70, 140 and 280 kDa were detected and found to form complexes: a dimer or more than dimer. Their enzyme activities were not inhibited by ethylenediaminetetraacetic acid. The optimal pH of this enzyme was found to be at neutral pH. Preferential expression of this novel gelatinolytic enzyme in amelanotic melanoma will be related to tumorigenic and metastatic phenotype of amelanotic melanoma.

Animals↗
PubMed1994

Polar lipids of a non-alkaliphilic extremely halophilic archaebacterium strain 172: a novel bis-sulfated glycolipid.

Extremely halophilic archaebacteria which require high salt concentrations for growth and survival contain glycerol diether analogues of phospholipids and sulfated glycolipids as major membrane polar lipids. A non-alkaliphilic, non-pigmented rod-shaped extreme halophile, isolated from sea sand in Japan and designated 'strain 172', was found to contain two phospholipids, phosphatidylglycerol (PG) and phosphatidylglyceromethylphosphate (PGP-Me), derived from both C20-C20- and C20-C25-glycerol diethers, and a novel major glycolipid (designated SGL-X). This glycolipid has been identified as a bis-sulfated diglycosyl C20-C20- or C20-C25-glycerol diether, on the basis of its TLC mobility, positive-staining behavior with sugar and sulfate-staining reagents, its mole ratio sulfate/glycolipid = 2.2, and by spectrometric analysis (IR and FAB-MS) of the intact and the desulfated SGL-X. The sugars were identified as mannose and glucose, after acid hydrolysis of SGL-X, by paper chromatography of the free sugars and GC-MS of the derivatized sugars (alditol acetates). Permethylation analysis and 1H- and 13C-NMR analysis established the position and configuration of the sugar linkages and the positions of the sulfate groups. The final structure of SGL-X (now designated S2-DGD-1) is proposed to be: 2,3-diphytanyl- or phytanyl-sesterterpenyl-1-[2,6-(HSO3)2-alpha-Manp-1--> 2- Glcp]-sn-glycerol. This lipid is the first bis-sulfated glycolipid to be reported in extremely halophilic archaebacteria, and is the first in the biosphere that possesses two sulfate groups attached to the same monosaccaride.

Archaea↗
PubMed1994

[A case of idiopathic hyperaldosteronism with normal plasma aldosterone concentrations for 5 years after onset: a 12-year follow-up study].

We report a 54-year old man diagnosed as idiopathic hyperaldosteronism (IHA) at least 12 years after the onset. At the age of 42, he showed hypertension (162/100mmHg), hypokalemia, metabolic alkalosis, low plasma renin activity (PRA) and normal plasma aldosterone concentration (PAC) in a supine posture. Both PRA and PAC were elevated after a 2-hour ambulation following furosemide (60mg) injection. Since the accumulation of radioactivity following 131I-aldosterol injection with combined administration of dexamethasone was equally detected in both adrenal areas, he was diagnosed as low-renin essential hypertension (LREH). Blood pressure (BP) decreased to the normal range after treatment with nifedipine (40mg/day). At the age of 47, however, BP was hypertensive (164/106mmHg) serum potassium (K) level was normal. Although PAC was normal in a supine posture, it increased after a 2-hour ambulation following furosemide (60mg) injection. PRA after the stimulation was still suppressed despite the increase in PAC. At the age of 54, BP was 172/94mmHg. Serum K level was 3.4mEq/L. PRA was suppressed below 0.1 ng/ml/hr, while PAC was above the normal range (170pg/ml) in a supine posture. Serum cortisol and urinary excretion of 17-OHCS and 17-KS were within normal limits. PRA was still suppressed below 0.1 ng/ml/hr after a 2-hour ambulation following furosemide (60mg) injection, but PAC was markedly increased (330pg/ml). There was a diurnal rhythm of aldosterone, which was parallel to that of ACTH.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1994

Effect of tri-n-butyltin on intracellular Ca2+ concentration of mouse thymocytes under Ca(2+)-free condition.

Effect of tri-n-butyltin at concentrations ranging from 100 nM to 1 microM on the intracellular Ca2+ concentration of mouse thymocytes was examined under Ca(2+)-free conditions in comparison with those of 50 nM A23187, 100 nM thapsigargin and 10 microM cyclopiazonic acid, using the fluorescent dye for intracellular Ca2+, fluo-3. Tri-n-butyltin persistently increased the intensity of fluo-3 fluorescence while A23187, thapsigargin and cyclopiazonic acid produced a transient augmentation of the fluorescence. Pretreatment with A23187 greatly decreased the fluorescence responses induced by 1 microM tri-n-butyltin. However, the effect of thapsigargin and cyclopiazonic acid on the tri-n-butyltin-induced response was much weaker than that of A23187. In the presence of tri-n-butyltin, the transient response produced by A23187 was greatly prolonged. Results may suggest that tri-n-butyltin increases the membrane Ca2+ permeability of the intracellular organelles (cellular calcium stores) and decreases the Ca2+ pump activity of thymocyte membrane, resulting in a sustained increase in the intracellular Ca2+ concentration under Ca(2+)-free concentration.

Aniline Compounds↗
PubMed1994

Characterization of 2',7'-dichlorofluorescin fluorescence in dissociated mammalian brain neurons: estimation on intracellular content of hydrogen peroxide.

The fluorescence of 2',7'-dichlorofluorescin (DCF) was measured in acutely dissociated rat cerebellar neurons as a mean of estimating the formation of reactive oxygen species (ROS). N,N-Diethyldithiocarbamate, an inhibitor for superoxide dismutase, reduced the intensity of DCF fluorescence in a dose-dependent fashion at concentrations of 30 nM to up to 10 microM. N-Ethylmaleimide, an inhibitor for glutathione peroxidase, augmented the DCF fluorescence in a dose-dependent manner at concentration of 10 microM to 1 mM while 3-amino-1,2,4-triazole, an inhibitor for catalase, did not change the fluorescence intensity even at concentrations as high as 1 mM. Hydrogen peroxide, applied externally at concentrations between 3 microM and 3 mM, augmented the fluorescence in a dose-dependent fashion. These results suggest the possibility that the DCF fluorescence may be useful in estimating the intracellular content of hydrogen peroxide of mammalian brain neurons.

Animals↗
PubMed1994

Portal vein aneurysm in the liver associated with multiple vascular malformations.

Portal vein aneurysm (PVA) includes focal dilatation of the portal vein, and was formerly thought to be a rare disease. We report a 46-year-old man with chronic aggressive hepatitis and intrahepatic portal vein aneurysm communicating with the hepatic vein. Hemangiomas in the liver and intracranial arteriovenous malformation (AVM) were also found. To our knowledge, this is the first report of a case of PVA in a patient with congenital intracranial AVM. As the PVA in this patient communicated with the hepatic vein, and as hemangiomas in the liver and intracranial AVM were also present, the pathogenesis in this patient seems to have been congenital anomaly of the vasculature.

Aneurysm↗
PubMed1994

Vascularized iliac bone graft based on a pedicle of upper lumbar vessels for anterior fusion of the thoraco-lumbar spine.

A new option for the use of a vascularized iliac bone graft, based on the upper (first or second) lumbar vessels, has been developed. As a pedicled graft, this supero-posteriorly-based vascularized iliac bone graft can reach the vertebrae from T8 to the sacrum, and the lower sternum and thoracic cage. In this report, the vascular anatomy of the flap and clinical experience using it for anterior spinal fusion are described.

Adult↗
PubMed1994

Application of an alpha-sidechain length-specific monoclonal antibody to immunoaffinity purification and enzyme immunoassay of 2,3-dinor-6-keto-prostaglandin F1 alpha from human urine.

2,3-Dinor-6-keto-prostaglandin F1 alpha (2,3-dinor-6-keto-PGF1 alpha) is a major urinary metabolite of PGI2 (prostacyclin) and one of the most reliable parameters of PGI2 production in vivo. A mouse was immunized with 2,3-dinor-6-keto-20-carboxy-PGF1 alpha conjugated to bovine serum albumin for preparation of a monoclonal antibody which recognized the difference in the alpha-sidechain length of 6-keto-PGF1 alpha and its 2,3-dinor-metabolite. A sensitive and specific enzyme immunoassay was developed by the solid-phase competition method with 2,3-dinor-6-keto-20-carboxy-PGF1 alpha labeled with peroxidase protein. The detection range of the assay was 14-1200 fmol (IC50 = 120 fmol). The cross-reactivities of the antibody with 6-keto-PGF1 alpha, 6,15-diketo-13,14-dihydro-PGF1 alpha, and other arachidonate metabolites were less than 0.01%. An immunoaffinity column was prepared by coupling the anti-2,3-dinor-6-keto-PGF1 alpha antibody to BrCN-activated Sepharose 4B. Human urine was applied to an octadecylsilyl silica cartridge, and the extract was applied to the immunoaffinity column. This procedure allowed an efficient separation of 2,3-dinor-6-keto-PGF1 alpha from unidentified urinary substances which interfered with immunoassay. Validity of the results obtained by the enzyme immunoassay was confirmed by GC/MS employing selected ion monitoring for quantification.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

The significance of gonadotropin-releasing hormone test for predicting fertility after varicocelectomy.

To predict the surgical outcome in 30 infertile men with varicocele, endocrinologic evaluation by the GnRH test was performed before and 6 months after the high ligation of the left internal spermatic vein. Semen analysis was performed and the levels of basal T and PRL were examined preoperatively and 6 months postoperatively. In the pregnancy group, the preoperative excessive response of LH to the GnRH test decreased significantly after surgery. Significant reduction in the LH response is considered to be a valuable parameter for predicting fertility.

Adult↗
PubMed1994

Monoallelic expression of normal mRNA in the PIT1 mutation heterozygotes with normal phenotype and biallelic expression in the abnormal phenotype.

The combined deficiency of thyrotropin, growth hormone and prolactin, caused by PIT1 abnormality manifests in the homozygous or heterozygous state. We studied a patient having an allele with Arg271Trp mutation, which produces clinical symptoms in heterozygotes by a dominant-negative effect. However, in the family, her father, grandmother and aunts had the same mutation without clinical symptoms, although the proband had typical phenotypic expression. We analyzed the PIT1 transcript in peripheral lymphocytes by reverse transcription-polymerase chain reaction and found monoallelic expression of normal allele in the father and grandmother and skewed pattern of biallelic expression in the proband. The phenotypic expression of PIT1 abnormality may depend on different transcription of the PIT1 gene.

Alleles↗