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Biomedical subjects

H Sugihara

Publications and source records attributed to H Sugihara.

At least 271 records · Page 15Linked to original sources

[Ultrasonic tissue characterization in hypertrophic cardiomyopathy: analysis of three-layered appearance of the ventricular septum by apical approach].

In normal hearts, two-dimensional echocardiography from the apical window displays the left ventricular wall as a three-layered appearance (TLA): central bright layer and bilateral sonolucent zones. The TLA is considered to reflect the normal myocardial architecture: the predominant latitudinal fiber bundles of the midwall layer, and longitudinal or oblique ones on both sides. We analysed the TLA of the ventricular septum in 20 normal subjects, 20 patients with left ventricular hypertrophy due to pressure load (LVH), and 81 patients with hypertrophic cardiomyopathy (HCM). Of the 81 HCM patients, the layering was often obscure or absent in 53 (65%), whereas LVH patients showed clear TLA as well as normal hearts. In patients with severe layering disorder (n = 30), the age at diagnosis was lower (40 +/- 15 vs 50 +/- 12, p less than 0.05), and familial occurrence (53 vs 11%, p less than 0.01) and severe functional limitation (NYHA greater than or equal to III) were more common (27 vs 4%) than in those with clear TLA (n = 28). The disturbed layering detectable by echocardiography may reflect the disorder of basic myocardial fiber architecture in the ventricular septum, and is likely to become a useful marker of the pathologic severity of the disease.

Adult↗

[Repeated blackout in a patient with accelerated idioventricular rhythm].

There has been no report that Accelerated Idioventricular rhythm (AIVR) causes a syncope attack. The patient described in this report is very rare because AIVR chronic without any heart diseases has been observed for 13 years, and because it is considered that AIVR is closely associated with his repeated blackouts. A 62-year-old male was admitted to our hospital because of repeated syncopal attacks. He reported that he occasionally felt lightheaded after strenuous lifting and pushing or pulling against resistance. We found that AIVR could produce a remarkable arterial pressure drop partly because of ventricular asynergy and loss of timed atrial contribution. Furthermore, we observed syncopal attacks during Valsalva maneuver and found abnormalities of baroreceptor reflex (Lack of reflex tachycardia and weakened evershoot phenomenon). It is concluded that AIVR is not a benign arrhythmia in this patient because it has been a possible cause of syncope attack due to systemic arterial pressure drop and baroreceptor abnormalities.

Accelerated Idioventricular Rhythm↗

[Clinical evaluation of 123I-BMIPP myocardial scintigraphy in patients with hypertrophic cardiomyopathy].

123I-BMIPP myocardial scintigraphy was performed in 13 patients with hypertrophic cardiomyopathy and compared with 201Tl myocardial scintigraphy performed within 3 months for evaluating the clinical significance of 123I-BMIPP myocardial scintigraphy. SPECT images were divided into 13 segments and segmental images were visually scored on a 4 (increased tracer uptake) to 0 (severely decreased tracer uptake) scale according to the tracer uptake. In comparison of 123I-BMIPP early images and 201Tl perfusion images, mismatches were seen in about 70% of all segments. The number of segments demonstrating lower myocardial uptake of 123I-BMIPP was larger than that of 201Tl. In hypertrophic regions, the tracer uptake of 123I-BMIPP early images was significantly lower than that of 201Tl images and the lower uptake of 123I-BMIPP delayed images was more marked. In non-hypertrophic regions, no significant difference was seen between the tracer uptakes of 123I-BMIPP early images and 201Tl images but the tracer uptake of 123I-BMIPP delayed images was significantly lower than that of 201Tl images. The mismatch between the tracer uptakes of 123I-BMIPP images and 201Tl images was thought to be a reflection of disordered myocardial fatty acid metabolism. "Washout", the difference between the tracer uptakes of 123I-BMIPP early images and delayed images was also thought to be a reflection of disordered myocardial fatty acid metabolism. These results suggest that 123I-BMIPP is a promising radiopharmaceutical for evaluating disordered myocardial fatty acid metabolism in patients with HCM.

Cardiomyopathy, Hypertrophic↗

[Diffuse subendocardial ischemia in a patient with aortic valve stenosis without coronary artery disease by exercise 201Tl SPECT].

A case of aortic valve stenosis without coronary artery disease was confirmed to have diffuse subendocardial ischemia by exercise Thallium-201 myocardial single photon emission computed tomography. A 72-year-old woman, who had been diagnosed as aortic valve stenosis, was admitted because of chest pain during exercise. In cardiac catheterization findings, the patient angiographically had normal coronary arteries and no asynergy of left ventricular wall motion. The peak flow velocity in continuous wave Doppler echocardiography was about 5.0 m/sec at aortic valve level, providing a pressure drop of 100 mmHg across a stenotic valve with calculating on a modified Bernoulli equation (PG = 4V2). Thallium-201 myocardial SPECT images during exercise showed a transient "dilation and a widespread wall thinning" of left ventricle with apical perfusion defect. Simultaneous electrocardiogram showed further ST depression and the patient had chest pain. In 6 months after aortic valve replacement the patient no longer demonstrated both apical perfusion defect and "wall thinning" in postoperative thallium-201 myocardial SPECT images and also had neither ST depression nor chest pain. Thus; a transient "dilation and wall thinning" of left ventricle in this patient is suspected to be a sign of diffuse subendocardial ischemia.

Aged↗

Morphology and modes of cell proliferation in earliest signet-ring-cell carcinomas induced in canine stomachs by N-ethyl-N'-nitro-N-nitrosoguanidine.

Signet-ring-cell carcinomas were induced in the stomach of 12 beagle dogs by p.o. administration of N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), and the morphology and modes of cell proliferation in an incipient stage of cancer growth were studied with bromodeoxyuridine (BrdUrd) incorporation. From 5 to 27 months after the completion of 8 months' carcinogen treatment, minute carcinomas were found in the stomachs of 9 dogs. Before sacrifice, the dogs were given a single or repeated i.v. injections of BrdUrd for 1-3 days. Minute signet-ring-cell carcinomas were found to form a layered structure, in which the cancer cells proliferated in the lamina propria at the gland-neck level and differentiated to postmitotic signet-ring cells at the upper and lower levels of the mucosa. From repeated injections of BrdUrd, the time required for all the proliferative cells to be labelled with BrdUrd (reflecting the maximum cell-cycle time) was estimated to be 1.7 days for the normal glands, and 2.7 days for minute signet-ring-cell carcinomas. From the labelling index with BrdUrd as well as from the morphology, earliest carcinomas were identified in the single gland. There remained atrophic normal epithelium commonly in the single-gland lesions. Proliferative atypical cells appeared to be shed into the stroma passively through the atrophy and subsequent collapse of the gland rather than through active invasion. This may be a reason why cancer cells in minute signet-ring cell carcinomas preserved the normal pattern of cell renewal movement to form the layered structure.

Adenocarcinoma, Mucinous↗

Reconstruction of the skin in three-dimensional collagen gel matrix culture.

The skin comprises three layers: epidermis, dermis, and hypodermis. We report here on a skin, reconstructed in vitro, that is composed of all three layers. The top-most layer, epidermis, was exposed to air by a new method. The exposure induced an extensive proliferation, and differentiation, i.e. keratinization was eventually observed in the cultured epidermal cells. Skin thus cultured will be a useful graft of transplantation and provide an ideal model system in which to study diseases of the skin.

Air↗

Isolation and characterization of hemorrhagic toxin from the venom of Trimeresurus elegans.

1. Hemorrhagic toxin from the venom of Trimeresurus elegans was purified in a homogeneous form using gel filtration and ion exchange chromatographies. 2. Hemorrhagic toxin possessed hemorrhagic and TAME (tosyl-L-arginine methyl ester) hydrolytic activities. These activities were inhibited when hemorrhagic toxin was incubated with benzamidine or N-bromosuccinimide. 3. Its mol. wt was 28,500 and the isoelectric point was 7.4. 4. This toxin contains ca 1.5 mol Ca per mol of protein.

Amino Acid Sequence↗

Characterization of Ac1-Proteinase from the venom of Agkistrodon acutus (Hundred-pace snake) from Taiwan.

1. Ac1-Proteinase from the venom of Agkistrodon acutus was isolated in a homogeneous form by a previously published method. 2. Ac1-Proteinase possessed lethal, hemorrhagic, caseinolytic, azocaseinolytic, azoalbumin hydrolytic and hide powder azure hydrolytic activities. 3. The toxin also hydrolyzed the oxidized B chain of insulin and fibrinogen. The cleavage sites in the oxidized B chain of insulin were identified as Ala(14)-Leu(15) and Tyr(16)-Leu(17). The A alpha chain of fibrinogen was digested. 4. Biological properties of Ac1-Proteinase were investigated further and are reported in this paper.

Amino Acid Sequence↗

Hemorrhagic protease from the venom of Calloselasma rhodostoma.

1. A hemorrhagic protease I (HP-I) was isolated from Calloselasma rhodostoma venom by Sephadex G-75, DEAE-Sephacel and Q-Sepharose column chromatographies. 2. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis. 3. HP-I has a molecular weight of 34,800 and possesses hemorrhagic and proteolytic activities. Both activities are inhibited by ethylenediaminetetraacetic acid (EDTA), 1,10-phenanthroline, ethyleneglycolbis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), and tetraethylenepentamine (TEP). However neither soybean trypsin inhibitor nor p-chlorobenzoic acid (PCMB) were found to have any effect. 4. The toxin contains 311 amino acid residues and exhibits an isoelectric point of 4.5. 5. The A alpha chain of fibrinogen was cleaved first, followed later by the B beta chain.

Amino Acid Sequence↗

Autopsy report of HTLV-I-associated myelopathy presenting with ALS-like manifestations.

We report an autopsy case of HTLV-I-associated myelopathy (HAM) showing clinical features indistinguishable from amyotrophic lateral sclerosis (ALS). A Japanese man developed bulbar palsy and generalized neurogenic muscular atrophy with symmetrical hyperreflexia at the age of 57 and died 4.5 years after the onset. He had an increased titer of anti-HTLV-I antibodies in serum and CSF. At autopsy, the leptomeninges were thickened and infiltrated with inflammatory cells. The brain and spinal cord were atrophic. The pyramidal tracts and anterior horn cells of spinal cord were severely degenerated but degenerative changes were also found in the basal ganglia, thalamus, brainstem tegmentum, and the dorsal columns of spinal cord. In all degenerative areas, prominent infiltrations of inflammatory cells were found. The present case indicates that HAM may produce clinical features indistinguishable from ALS.

Amyotrophic Lateral Sclerosis↗

Morphological and functional comparison of subcapsular small cells, subcapsular large cells and inner layer cells of bovine adrenal cortex.

Subcapsular small cortical cells (SC cells) and subcapsular large cortical cells (LC cells) of bovine adrenal cortex were cultured separately after purification by unit gravity sedimentation, and then compared with inner-half layer cells (IL cells) prepared by the same method. Both SC and LC cells were polygonal in shape and their mitochondria were elongated with lamellar cristae. SC cells became as large as LC cells on day 6 of culture with increased cytoplasmic lipid droplets, whereas IL cells showed no change in size. IL cells were spindle-shaped and had mitochondria with tubulovesicular cristae. Both SC and LC cells produced 11 beta-deoxycorticosterone, corticosterone, aldosterone and small amounts of 17 alpha-hydroxyprogesterone (17 alpha-OH-Prog) and cortisol (F). IL cells produced much more 17 alpha-OH-Prog and F than SC or LC cells. When stimulated with ACTH, cortical cells in each group showed cellular retraction and their mitochondria became spherical. The amounts of 17 alpha-OH-Prog and F increased in all groups, especially in IL cells. These results show that LC cells have similar characteristics to SC cells in both morphology and function, and that they differ from IL cells, which correspond to classical fasciculata-reticularis cells.

17-alpha-Hydroxyprogesterone↗

Genomic organization of Drosophila choline acetyltransferase.

Choline acetyltransferase (ChAT; acetyl-CoA:choline-O-acetyltransferase; EC 2.3.1.6) is the enzyme responsible for the synthesis of the neurotransmitter acetylcholine and is thus the genetic determinant of neurons with a cholinergic phenotype. We have screened a Drosophila genomic library using a cRNA probe, transcribed from Drosophila ChAT cDNA, and isolated three independent clones representing all the exons of this gene. The gene spans more than 26 kb of DNA and is organized into eight exons containing 594, 80, 192, 759, 408, 147, 201, and 1,612 nucleotides. All inserts that hybridized with a cRNA probe have been subcloned and the sequence of intron/exon boundaries determined. The only part of the ChAT gene not represented in our clones is a part of the first intron. A minimum size for this uncloned DNA has been deduced from Southern analysis of Drosophila genomic DNA. We also have probed the transcripts of the ChAT gene by northern analysis of total Drosophila RNA using two different exon-specific antisense RNA probes. An exon I probe detected two bands of RNA whereas an exon VIII probe hybridized with only the smaller band, previously identified as ChAT mRNA. These results indicate a complex transcription pattern for the ChAT locus in Drosophila.

Amino Acid Sequence↗

Susceptibility to active oxygen species of protective and nonprotective strains on the challenge of Salmonella enteritidis by immunization with culture filtrate.

Protective ability against the challenge of different strains by immunization with culture filtrate (CF) obtained from Salmonella enteritidis was investigated. It was shown that the different strains of S. enteritidis can be separated into two distinct groups of protective (2547, 116M, 116-54, SR-98G, and 3775) and nonprotective strains (2822, 3975, and IID-604). Using a cell-free microbicidal system, the susceptibilities of these strains to active oxygen species was evaluated. S. enteritidis was found to be susceptible to these active oxygen species, however no differences between the protective and nonprotective strains were observed. Both catalase (H2O2 scavenger) and histidine (1O2 scavenger) inhibited the bactericidal activity of the xanthine-xanthine oxidase system. Therefore, among the various oxygen intermediates, H2O2 and 1O2 appears to be necessary for killing of S. enteritidis. In tests for the ability to trigger an oxidative burst in murine peritoneal macrophages, strain 2547 triggered O2 generation at levels as high as those observed with strain 2822. These studies indicate that the difference between the protective and nonprotective strains is not attributed to susceptibility against active oxygen species nor to the ability to trigger an oxidative burst. From these observations, it is suggested that the difference is not due to differences in resistance to the killing of different strains within macrophages.

Animals↗

Difference in the protection against infection with different challenge strains of Salmonella enteritidis by killed vaccine.

Differences in protection against the challenge of different strains of formalin-killed cells obtained from Salmonella enteritidis were investigated. When strains 2547, 116M, 116-54, SR-98G, and 3775 were used as the challenge strain, protective effects were apparent in groups of mice immunized with formalin-killed cells from S. enteritidis strains (protective strains). Conversely, no protective effects were observed with the challenge of strains 2822, 3975, and IID-604 (nonprotective strains). Electrophoretic banding patterns of lipopolysaccharides in SDS-PAGE were similar between the LPS obtained from the various strains used in this study. Additionally, no differences in sensitivity to macrophage intracellular killing were observed between the protective and nonprotective strains. Phagocytic experiments by macrophages in vitro indicated that immune serum used as the opsonin promotes phagocytosis of various strains by macrophages as compared to using normal serum as the opsonin, but the rate of phagocytosis enhanced by immune serum is higher in protective strains than nonprotective strains. In studies of passive transfer of immune serum, it was found that mice passively immunized with immune serum could only protect against infection by challenging with protective strains with the exception of strain SR-98G. These results suggest that the protective effect observed with the challenge of protective strains may be due to macrophage phagocytosis enhanced by opsonization with immune serum.

Animals↗

Electrical stimulation of hypothalamic periventricular nucleus is followed by a large rebound secretion of growth hormone in unanesthetized rats.

The effect of electrical stimulation of the hypothalamic periventricular nucleus (PVN) on plasma GH profile was studied in unanesthetized female Wistar rats. A bipolar concentric electrode was implanted into the PVN, hypothalamic ventromedial nucleus (VMH), or intervening area between the PVN and VMH. Serial blood specimens were collected from an indwelling right atrial cannula. Plasma GH levels were reduced significantly during electrical stimulation of PVN, and a large rise of plasma GH levels followed after cessation of stimulation. An identical plasma GH profile was observed in response to the repeated stimulation. This rebound secretion of GH was completely inhibited by the administration of rat GRF antiserum. The effect of electrical stimulation of VMH on plasma GH levels was similar to that of PVN stimulation. However, the stimulation of hypothalamic area intervening between PVN and VMH was not followed by a surge of GH secretion. Since a continuous exposure of somatotrophs to GRF even in a concurrent presence of somatostatin (SS) is known to induce attenuation of the GH response to GRF through receptor effect, the results suggest that the release of endogenous GRF is augmented following the cessation of electrical stimulation of neurons providing hypophysiotropic SS.

Animals↗