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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 487 records · Page 27Linked to original sources
PubMed1994

[Characteristic event-related potentials evoked by somatosensory tasks in a patient with right-left disorientation and finger agnosia].

Event-related brain potentials associated with both somatosensory and auditory detection tasks were recorded from the scalp in a 63-year-old man with finger agnosia and right-left disorientation resulted from cerebral infarction located around the region of the left angular gyrus. In a somatosensory oddball paradigm for discrimination between the right index finger (target, P = 0.2) and the left index finger (non-target, P = 0.8), early cognitive components P100, N140 and processing negativity were observed both in the target responses and non-target responses, however, no P300 component was recorded in both paradigms. In another paradigm to discriminate the index finger (target, P = 0.2) from small finger (non-target, P = 0.8) in the right hand, no P300 was evoked and only processing negativity was recorded both in the target responses and nontarget responses. These phenomena were obtained through characteristic behavior that the patient paid attention to the target stimuli as well as non-target stimuli and mentally counted them without discrimination. In contrast, in an auditory oddball paradigm P300 was clearly demonstrated to target stimuli that the patient correctly could count. The normal appearance of P300 in auditory detection tasks strongly suggests that the neural generator for the P300 was reserved intact. These results indicate that somatosensory information processing might be disturbed at the level of sensory discrimination needed for generation of P300 in our patient. It is also proposed that the neural events for somatosensory discrimination and auditory discrimination would take separate channels each other to reach the common generator of p300 in information processing.

Brain↗
PubMed1994

The re-evaluation of sex steroids metabolism in patients with non-alcoholic liver cirrhosis.

We examined the serum levels of testosterone (T), androstenedione (delta 4-A), estrone (E1), estradiol (E2), and dehydroepiandrosterone sulfate (DHEA-S) in the non-alcoholic cirrhotic male patients when divided into compensated or decompensated state. Serum level of T was significantly elevated in compensated cirrhotic patients (9.63 +/- 1.00 ng/ml, mean +/- SE) compared to that in decompensated cirrhotic patients (5.63 +/- 0.69 ng/ml, p < 0.01) and in aged-matched normal controls (4.95 +/- 0.38 ng/ml, p < 0.01). Serum levels of E1, E2 and delta 4-A tended to be increased in decompensated cirrhotic patients, while there was not a significant difference decompensated cirrhosis compared to those of normal controls. Serum concentration of cholinesterase, indicative one of the representative residual liver function, showed a good positive correlation to T (r = 0.53, p < 0.01), and a negative correlations to E1 (r = -0.67, p < 0.01), E2 (r = -0.77, p < 0.01), delta 4-A (r = -0.57, r = p < 0.01). Also, we examined the relationship of the serum levels to gynecomastia or esophageal varices. The cirrhotics with gynecomastia showed significantly higher serum levels of E1, E2, and delta 4-A, and lower level of T than those without gynecomastia. And the cirrhotics with esophageal varices showed the greater level of T than those without esophageal varices. Our study suggests that low serum testosterone level of men with nonalcoholic cirrhotic is not a common finding, especially in compensated state.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Surgical treatment for a coarctation of the aorta in an advanced aged woman].

A 55 year old woman with coarctation of the aorta underwent coarctectomy by end to end anastomosis successfully. She had no showed sign and symptom except hypertension until 55 years of age. Preoperative findings of cardiac catheterization and aortography were as follows: a pressure gradient of 100mmHg at the severe, short segmental coarctation and prominent development of internal mammary artery and intercostal artery as collateral circulation. After coarctectomy, hypertension improved and postoperative examination revealed no pressure gradient. This is a surgically resected case of coarctation of the aorta in the most advanced aged woman in Japanese literature.

Anastomosis, Surgical↗
PubMed1994

Possible involvement of endothelin-1 in cardiac hypertrophy.

In an attempt to ascertain a possible involvement of endothelin-1 (ET-1) in the development of cardiac hypertrophy induced by hemodynamic overloads in vivo, the expression of prepro ET-1 mRNA in the cardiac tissue and the plasma level of ET-1 were determined in rats undergoing various treatments for inducing cardiac hypertrophy. One week after aortic banding (AB), the rat exhibited left ventricular hypertrophy characterized by ventricular wall thickening, i.e. concentric hypertrophy. In contrast, the aortic regurgitation (AR) produced left ventricular enlargement without wall thickening 1 week after the operation, i.e. eccentric hypertrophy. Monocrotaline treatment (s.c.) also caused marked hypertrophy in the right ventricle (concentric hypertrophy) 3 weeks later, which was accompanied by a severe pulmonary hypertension (MCT-PH). A Northern blot analysis revealed that AB and MCT-PH markedly increased the expression of prepro ET-1 mRNA in the left and right ventricles, respectively. The rats with MCT-PH but not with AB displayed a significant higher level in their plasma ET-1 levels compared with control animals. In contrast, the rats undergoing AR surgery exhibited no significant elevation in either prepro ET-1 mRNA in the heart or the plasma ET-1 concentration. The results of the present study suggest that ET-1 is involved at least in part in the development of concentric but probably not eccentric cardiac hypertrophy induced by hemodynamic overloads.

Animals↗
PubMed1994

[A case report of tricuspid replacement for the acquired tricuspid stenosis at the time of reoperation].

A 57-year-old woman, who underwent aortic valve replacement and open mitral commissurotomy nine years ago, was admitted with congestive heart failure due to mitral regurgitation and tricuspid regurgitation, for which we planned mitral valve replacement and tricuspid annuloplasty. Intraoperatively, the orifice of tricuspid valve was stenosed like fish-mouth, which we attempted to make commissurotomy and modified Kay's annuloplasty, but failed to decrease the central regurgitation. A CarboMedics 23 mm prosthesis was implanted in the mitral position and a Capentier-Edwards 29 mm in the tricuspid position. She had recovered from congestive heart failure postoperatively, no regurgitant flow was detected in right ventriculography.

Female↗
PubMed1994

[A case report of giant mediastinal thyroid carcinoma with SVC syndrome].

A 78-year-old man with SVC syndrome caused from compression by follicular carcinoma of the thyroid which extended to the mediastinum was presented. CT and MRI demonstrated a giant right thyroid tumor which extended to the mediastinum and displaced the trachea. The resection of 675 g-tumor was performed through median sternotomy and right collar incision without reconstruction of SVC. His postoperative course was complicated with recurrent nerve paralysis which had been gradually improved for several months. At present, he has been freed from SVC syndrome.

Adenocarcinoma, Follicular↗
PubMed1993

Increased production of endothelin-1 in the hypertrophied rat heart due to pressure overload.

Endothelin-1 (ET-1) has been demonstrated to induce hypertrophy in cultured cardiac myocytes. We investigated the production of ET-1 in the heart of aorta-banded rats in vivo. Seven days after the banding of the abdominal aorta, rats developed a significant left ventricular hypertrophy. The tissue content of mature ET-1 and the level of expression of prepro ET-1 mRNA were higher in the left ventricle of aorta-banded rats than in those of sham-operated rats. The expression of prepro ET-1 mRNA in the right ventricle was not different between the two groups. These findings indicate that the production of ET-1 increased in the hypertrophied left ventricle, thereby suggesting the possible involvement of endogenous ET-1 in the development of cardiac hypertrophy due to pressure overload.

Animals↗
PubMed1993

Molecular cloning and expression of a 90-kDa diacylglycerol kinase that predominantly localizes in neurons.

A diacylglycerol kinase cDNA was isolated from a rat brain cDNA library. This cDNA encoded an 801-amino acid protein of 90,287 Da. This 90-kDa diacylglycerol kinase showed 58% identity in deduced amino acid sequence with a previously isolated rat 80-kDa diacylglycerol kinase. EF-hand motifs, cysteine-rich zinc-finger-like sequences, and putative ATP-binding sites were all conserved between the two kinase species. However, mRNA encoding the 90-kDa kinase was confined to restricted neuronal populations such as the caudate-putamen, the accumbens nucleus, and the olfactory tubercle. Further, the 90-kDa kinase was found to exhibit high phosphorylation activity for long-chain diacylglycerols and was mainly associated with the membrane fraction when the cDNA was transfected into COS-7 cells.

Amino Acid Sequence↗
PubMed1993

Different mode of action of endothelin-1 in parietal and visceral veins.

The mode of contractile effect of endothelin-1 in venous smooth muscles was evaluated using three isolated veins, the jugular vein, the portal vein and the inferior caval vein of dogs. The contractile responses to endothelin-1 were attenuated by atropine and augmented by neostigmine in the inferior caval and portal veins, but were not affected by either agent in the jugular vein. We conclude that the contractile responses of visceral veins to endothelin-1 are partly mediated via endogenously released acetylcholine.

Animals↗
PubMed1993

[Clinical experiences in using ITC silastic detachable balloons--report on 30 cases with various neurovascular diseases].

As defective balloons often lead to disasters, reliable detachable balloons have long been eagerly awaited. We had the opportunity of using ITC detachable balloons on 30 cases with various neurovascular diseases. No defective balloon was found during in vitro testing done immediately prior to their placement in the patient's vascular system. Moreover, there was no premature detachment during catheter manipulation or early deflation within several weeks after detachment. Both immediate and long term follow up showed balloon embolization would be the first choice for various direct arteriovenous fistulae. Also, anatomically inaccessible aneurysms with small necks, less than 1 cc in volume, could be successfully treated by detachable balloons. However, detachable balloons are not ideal embolic material for large and giant aneurysms. In conclusion, when used by properly trained personnel, ITC silastic detachable balloons are a safe, easy to use and reliable option.

Adolescent↗
PubMed1993

Arginine-vasopressin increases the release of ET-1 into perfusate of rat mesenteric artery.

The regulatory systems of endogenous endothelin-1 (ET-1) production from intact tissues and the effects of produced ET-1 on vascular tonus by a closed circuit perfusion system of rat mesenteric artery were investigated. It was demonstrated that ET-1 is released from intact mesenteric arterial beds from Wistar rats both under basal conditions and after stimulation with arginine-vasopressin (AVP) (10(-10)-10(-9) M). Furthermore, AVP (10(-10)-10(-9) M) markedly and dose-dependently induced the expression of prepro ET-1 mRNA in the mesenteric arterial beds. Increased release of ET-1 by AVP may contribute to maintaining vascular tonus. Concomitant addition of actinomycin D inhibited the increased expression of prepro ET-1 mRNA and reduced the amount of immunoreactive ET-1 found during the 6-hour perfusate from AVP (10(-10) M)-stimulated and -unstimulated tissues.

Animals↗
PubMed1993

Molecular cloning of a novel putative G protein-coupled receptor expressed in the cardiovascular system.

A novel cDNA clone encoding a putative G protein-coupled receptor has been isolated from a rat aortic smooth muscle cDNA library. Sequence analysis of this clone reveals the structural features characteristic of this superfamily, with a high degree of sequence similarity to the Edg-1 receptor previously reported to be expressed in vascular endothelial cells. This novel receptor mRNA is expressed predominantly in the lung and heart. Although the ligand for this receptor has yet to be identified, the results suggest the existence of a new receptor subfamily in the cardiovascular system thus far unrecognized.

Amino Acid Sequence↗
PubMed1993

Characterization of phosphoramidon-sensitive metalloproteinases with endothelin-converting enzyme activity in porcine lung membrane.

Endothelin-1 (ET-1), a 21 amino-acid potent vasoconstrictor peptide, is produced from the biologically inactive intermediate big ET-1 via an endoproteolytic cleavage between Trp-21 and Val-22 by endothelin converting enzyme (ECE). cDNA sequence analysis predicts that the two other members of the endothelin family, ET-2 and ET-3, are also generated from the corresponding intermediates called big ET-2 and big ET-3, respectively. The metalloproteinase inhibitor phosphoramidon inhibited the conversion of big ET-1 into mature ET-1 both in vivo and in cultured endothelial cells, suggesting that ECE may be a neutral metalloproteinase. In this study, we solubilized and partially purified ECE from the membrane fraction of porcine lung. Using gel filtration chromatography, we separated two distinct ECE activities, designated M1 (apparent molecular mass approx. 300 kDa) and M2 (approx. 65 kDa). Optimum pH for the cleavage of big ET-1 by M1 and M2 was 7.0 and 7.5, respectively. M1 efficiently converted human big ET-1(1-38) to ET-1, but not human big ET-2(1-37) or human big ET-3(1-41)-amide. In contrast, M2 converted both big ET-1 and big ET-2, but not big ET-3. M1 was inhibited by phosphoramidon (IC50 approx. 1 microM) but not by thiorphan or bacitracin. In contrast, M2 was inhibited by much lower concentrations of phosphoramidon (IC50 approx. 0.3 nM), as well as by thiorphan and bacitracin. ECE activity in M1 was able to bind to a concanavalin A-agarose column and was eluted by alpha-methyl-D-glucoside, indicating that the ECE is glycosylated. From these results, M1 and M2 from the porcine lung membrane are similar to the candidate of ECE in endothelial cells and neutral endopeptidase in kidney (EC 3.4.24.11), respectively. Taken in conjunction with the previous finding that neither thiorphan nor bacitracin affected the conversion of endogenously synthesized big ET-1 in cultured endothelial cells, we conclude that physiologically relevant ECE found in the endothelial cells is more similar to M1 than to M2.

Animals↗
PubMed1993

An experimental recurrence model for malignant fibrous histiocytoma induced by 4-hydroxyaminoquinoline 1-oxide in the rat.

To clarify the relationship between local recurrence of mesenchymal tumors and their malignant potentiality, we made an experimental recurrence model for malignant fibrous histiocytoma (MFH) induced by 4-hydroxyaminoquinoline 1-oxide in the rat by repeated excisional operations. By the repeated excision, the number of recurrent tumors increased, and the doubling time of tumor growth was shortened. The mean doubling time of primary tumors was 6.6 days, that of the first locally recurrent tumors was 4.3 days, and that of the second locally recurrent tumors was 3.3 days. However, mitotic count and 5-bromo-2-deoxyuridine (BrdU) labeling index did not change. This study proved experimentally that MFH shows more rapid growth through repeated local recurrences, and this experimental model may provide a better understanding of the local recurrence of MFH.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1993

Characterization of Geotrichum candidum lipase III with some preference for the inside ester bond of triglyceride.

A new form of Geotrichum candidum lipase with a unique positional specificity was found to exist in the culture broth as a minor component together with the well-documented major form. Unlike the major form, which cleaves both the inside and outside ester bonds of triglyceride indiscriminately, the newly isolated form showed some preference for the inside (2-position) ester bond. The new enzyme was also characterized by its own fatty acid specificity, i.e., an outstandingly high activity towards triolein and methyl oleate among the simple triglycerides and fatty acid methyl esters tested. Moreover, the enzyme possessed a specific activity three times as high as the major form. Notable difference in circular dichroism spectra were observed between the two forms, indicating distinct conformational differences. Edman degradation revealed that the N-terminal sequence of the new form differed from that of the major form, thus demonstrating the existence of a novel lipase gene on the chromosome.

Amino Acid Sequence↗