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K Matsuda

Publications and source records attributed to K Matsuda.

At least 523 records · Page 29Linked to original sources
PubMed1991

[Characterization of muscarinic acetylcholine receptors in the isolated gastric chief cells from guinea pig].

The muscarinic receptor system involved in pepsinogen secretion from isolated guinea pig gastric chief cells was investigated by assessing the effect of muscarinic receptor antagonists on carbamylcholine (CCh)-induced pepsinogen secretion. CCh stimulated pepsinogen secretion in a dose dependent manner with the maximal and the half-maximal stimulatory concentrations at 10(-4) and 3 x 10(-6) M, respectively. Each of five different muscarinic receptor antagonists such as atropine, pirenzepine, 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), AF-DX116 and scopolamine reduced pepsinogen secretion stimulated by graded concentration of CCh, but did not alter the maximum secretion. The increase in concentration of each antagonist caused parallel rightward shift of the dose response curve to CCh. Schild analysis of the inhibition of CCh-induced pepsinogen secretion by the antagonists showed that pA2 values of atropine, scopolamine and 4-DAMP are 8.8, 9.2 and 9.0, respectively. On the other hand, pA2 values of pirenzepine and AF-DX116 are 6.5 and 5.9, respectively, suggesting that the muscarinic receptor mediating pepsinogen secretion from chief cells has a intermediate affinity for pirenzepine and a low affinity for AF-DX116. These results suggest that the muscarinic acetylcholine receptor mediating pepsinogen secretion from gastric chief cells is the M3 subtype.

Animals↗
PubMed1991

[201Tl-reverse redistribution in a case with stunned myocardium].

A 58-year-old man was admitted to our hospital because of chest pain. Electrocardiogram showed giant negative T waves in leads I, II, III, aVl, aVf and V2 through V6. Echocardiogram showed anterior wall motion abnormality. Rest-redistribution thallium scan obtained 3 days after admission revealed reverse redistribution in antero-apical area. Coronary angiogram showed no significant stenotic lesions and left ventriculogram in chronic stage showed improvement of wall motion abnormality. Repeat thallium scan in chronic stage showed disappearance of perfusion defect in apical area. It was difficult to diagnose myocardial viability in our case with stunned myocardium because rest-redistribution thallium scan showed reverse redistribution. As the mechanism of this finding, early coronary recanalization in acute stage of the event was suspected.

Coronary Disease↗
PubMed1990

Clinical evaluation of a new bilayer "artificial skin" composed of collagen sponge and silicone layer.

A bilayer "artificial skin" composed of an outer layer of silicone and an inner sponge layer of collagen and chondroitin sulphate has been developed by modifying the technique proposed by Yannas et al. (1980). Following experimental successes, the "artificial skin" was applied clinically. It was placed on the skin defects of 10 patients. Three weeks after application the outer layer of silicone sheet was peeled off and thin split thickness skin was grafted onto the newly synthesised dermis-like tissue. Secondary skin grafts took perfectly in all cases and postoperative appearance was satisfactory.

Adolescent↗
PubMed1990

Development and application of homologous radioimmunoassay for newt prolactin.

A specific and sensitive homologous radioimmunoassay (RIA) for newt (Cynops pyrrhogaster) prolactin (PRL) was developed. PRL isolated from newt pituitary glands was used for generating antiserum in a rabbit, for radioiodination, and for the standard. Several dilutions of plasma and pituitary homogenate of newts yielded dose-response curves which were parallel to the standard curve. Plasma from hypophysectomized newts showed the least amount of cross-reaction. Pituitary homogenates of other species of urodeles such as Ambystoma mexicanum and Onychodactylus japonicus gave inhibition curves which were parallel to the standard curve. Purified PRLs of anurans such as Rana catesbeiana and Bufo japonicus gave inhibition curves which did not parallel the standard. Bovine PRL and ovine PRL showed no inhibition of binding even at relatively high doses in this RIA. The RIA was applied to the determination of plasma and pituitary PRL levels in the adult newts treated with dopamine agonist (bromocriptine) and/or antagonist (pimozide). Pimozide enhanced PRL levels and bromocriptine antagonized it, while pituitary PRL levels were not appreciably changed.

Animals↗
PubMed1990

Purification and properties of newt prolactin.

A highly purified prolactin (PRL) was obtained from pituitary glands of newts, Cynops pyrrhogaster, by extraction of acetone-dried powder with acid acetone and high-performance liquid chromatography (HPLC) on Mono-Q (anion exchange), Superose-12 (gel filtration), and TSK-gel ODS-120T (reverse-phase) columns with a yield of 4.5 mg per 325 mg of protein starting material. Purification was monitored by SDS-polyacrylamide gel electrophoresis (PAGE) and Western blotting analysis employing antiserum against bullfrog PRL. Newt PRL thus obtained has a molecular weight of 23,000 as determined by SDS-PAGE. The isoelectric point is 4.7 as determined by isoelectric focusing. The amino acid composition closely resembles that of anuran PRLs. This hormone was as potent as bovine PRL in stimulating collagen synthesis in the bullfrog tadpole tail fin. Antiserum against newt PRL was produced by immunizing a rabbit. Histological studies on newt adenohypophyses revealed that the cells that immunologically reacted with the antiserum against newt PRL correspond to the ones positively stained with the antiserum against bullfrog PRL.

Amino Acids↗
PubMed1990

Difference in effects of sodium fluoride and cholecystokinin on diacylglycerol accumulation and calcium increase in guinea pig gastric chief cells.

In isolated guinea pig gastric chief cells, sodium fluoride (NaF) stimulated a monophasic increase in diacylglycerol accumulation, while cholecystokinin (CCK) strongly stimulated its biphasic accumulation. NaF evoked an increase in initial Ca2+ influx rate with a slow increase in intracellular free Ca2+ concentration [( Ca2+]i), while CCK stimulated a rapid increase in [Ca2+]i followed by a late sustained phase of the [Ca2+]i increase. Lanthanum chloride (La3+) effectively blocked NaF-stimulated increase in [Ca2+]i, but it blocked only CCK-stimulated late sustained phase of [Ca2+]i increase. The effect of NaF on pepsinogen secretion was enhanced in the presence of 100 microM AlCl3. Furthermore, pertussis toxin did not affect NaF-evoked diacylglycerol accumulation at all. These results suggest that NaF may activate a pertussis-toxin insensitive guanine nucleotide regulatory protein (G protein) coupled to a signal transducing mechanism which seems to be distinct from that activated by CCK, thereby inducing increases in diacylglycerol accumulation, Ca2+ influx and pepsinogen secretion in guinea pig gastric chief cells.

Animals↗
PubMed1990

Influence of glycosaminoglycans on the collagen sponge component of a bilayer artificial skin.

A bilayer artificial skin composed of a silicone membrane and a collagen sponge layer containing glycosaminoglycans (GAGs) was first developed by Yannas and Burke. They reported that GAGs contained in the collagen sponge layer contributed to the function of the artificial skin. In an attempt to assess the effect of GAGs in the collagen sponge layer, the electron microscopic structure, mechanical strength of collagen sponges, and cell proliferation were examined in vitro, using four kinds of collagen sponges containing: no GAG, chondroitin 6-sulphate (C6S), dermatan sulphate (DER), and hyaluronic acid (HYA). The results indicated that: (1) addition of GAGs scarcely affected the mechanical structure of collagen sponges; (2) addition of C6S and DER reinforced mechanical strength, while addition of HYA did not; (3) addition of C6S and DER significantly decreased cell proliferation.

Artificial Organs↗
PubMed1990

Experimental study of a newly developed bilayer artificial skin.

A bilayer artificial skin composed of an outer layer of silicone polymer and an inner sponge layer of collagen containing chondroitin 6-sulphate was developed by modifying the technique proposed by Yannas et al. The artificial skin was placed on the skin defects on the backs of rats. Histological observation indicated that fibroblasts and capillaries infiltrated into the pores and filled in lattice spaces, resulting in synthesis of the connective tissue matrix and absorption of the original network of collagen and chondroitin 6-sulphate. Epidermal cells migrated from the edge of the wound between the two layers. Post-operative contracture in the wound with the artificial skin was significantly less than in the control.

Animals↗
PubMed1990

Calcium is essential for both the membrane binding and lytic activity of pore-forming protein (perforin) from cytotoxic T-lymphocyte.

The influence of Ca on the membrane binding and lytic activity of lymphocyte pore-forming protein (perforin) was studied. In the absence of Ca, perforin did not bind to the target membranes and did not support lysis of the target cells. In contrast, in the presence of Ca perforin was able to bind to the cell membrane (Km greater than 0.2 mM). Almost all the perforin molecules bind to the membrane within 1 min at 0 degrees C. The addition of EDTA abolished the binding, indicating that the effects of Ca on the membrane binding are reversible. On the other hand, the perforin-mediated lysis of target cells was temp-dependent and also required the presence of Ca in the reaction mixture (Km = 0.05 mM). The difference between the Km values for the membrane binding and lytic activity suggests the presence of two distinct Ca-requiring steps in perforin-mediated target cell lysis.

Animals↗
PubMed1990

The transient increase of urinary digitalis-like substance excreted during excess sodium intake in reduced renal mass rats.

Urinary immunoreactive endogenous digitalis-like substance (EDLS) excretion was studied in gradually reduced renal mass rats (RRM). Urinary EDLS increased immediately after the start of 1% NaCl ingestion, then it returned to the basal level 2 weeks later. Both urinary sodium excretion and urinary EDLS were significantly higher in 3/6 and 4/6 RRM than in control until 2 weeks after starting 1% NaCl. However, there was no difference in blood pressure between the groups. Transient EDLS increase may play an important role in maintaining sodium and water homeostasis, but its transient increase apparently does not contribute to blood pressure elevation.

Animals↗
PubMed1990

Mode of action of glycogen branching enzyme from Neurospora crassa.

Neurospora crassa branching enzyme [EC 2.4.1.18] acted on potato amylopectin or amylose to convert them to highly branched glycogen-type molecules which consisted of unit chains of six glucose units. The enzyme also acted on the amylopectin beta-limit dextrin, indicating that the enzyme acted on internal glucose chains as well as outer chains. By the combined action of N. crassa glycogen synthase [EC 2.4.1.11] and the branching enzyme, a glycogen-type molecule was formed from UDP-glucose. In the presence of primer glycogen, the glucose transfer reaction was accelerated by the addition of branching enzyme. On the other hand, the glucose transfer reaction by glycogen synthase did not occur without primers. When the branching enzyme was added, the glucose transfer occurred after a short time lag. This recovery of the glucose transfer reaction did not occur upon addition of the inactivated branching enzyme. The structure of the product formed by the combined action of the two enzymes was different from that of the intact N. crassa glycogen with respect to the distribution patterns of the unit chains.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1990

A kinetic study of the interaction between glycogen and Neurospora crassa branching enzyme.

The interaction of Neurospora crassa branching enzyme (1,4-alpha-D-glucan:1,4-alpha-D-glucan 6-alpha-(1,4-alpha-glucano)-transferase) [EC 2.4.1.18] with substrate glycogen or amylopectin was studied by affinity electrophoresis. By this method, the dissociation constants (K) of the branching enzyme for oyster glycogen (CL-12.2, OCL-6.3) and for potato amylopectin (CL-20, OCL-12.8) were determined to be 13.3 mM and 0.355 mM, respectively. The affinity of the enzyme to the substrate glycogen increased with the increase of outer chain length (OCL) of the substrate. The thermodynamic parameters of the branching reaction were obtained from the changes of K values of the enzyme-substrate complex at various temperatures. The value of heat change (delta H degree) of the branching reaction for amylopectin was -27.7 kcal/deg.mol. The most suitable length of glucan chain for branching was greater than 12 glucose units.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1990

Organization and structure of the 5' flanking region of the rat serine dehydratase gene.

For study of the mechanisms regulating the induction of serine dehydratase by various hormones in rat liver [Noda et al. (1988) J. Biol. Chem. 263, 14764-14768], we cloned the gene for this enzyme from a rat genomic library. The gene spans about 7.5 kilobases and consists of nine exons and eight introns. The exon-intron boundaries are consistent with the "GT-AG" rule. Southern blot analysis of rat genomic DNA suggested the presence of one copy of serine dehydratase gene per haploid genome. The 5' end of serine dehydratase mRNA is located 148 nucleotides upstream of the initiator methionine codon. ATG, determined by primer extension analysis and S1 nuclease mapping, although an alternative transcription initiation site(s) may be located a few bases downstream. The 5' flanking region of the gene lacks typical TATA and CCAAT sequences, but contains AATAAA and CATT sequences, at -25 to -20 and -54 to -51, respectively. Furthermore, there are five GC box-related sequences. There are three putative glucocorticoid-responsive elements and two copies of the CGTCA motif of the cAMP-responsive element upstream of the promoters. The 5' flanking sequence shows more than 98% homology with that reported by Ogawa et al. [(1988) Proc. Natl. Acad. Sci. U.S.A. 85, 5809-5813], but the first exons have different sequences. Another difference is that a segment of 108 nucleotides is located just upstream of exon 5 in the sequence reported here, but is included as an exon in the sequence of Ogawa et al. The possibility to producing two species of serine dehydratase mRNAs from a single gene by transcription from different sites and alternative splicing is discussed.

Animals↗
PubMed1990

Surgical treatment of epilepsy in the comprehensive care program: advantages and considerations.

To properly establish the surgical treatment of epilepsy in the comprehensive care program, we planned a surgical strategy mainly for a temporal lobe epilepsy and have performed 60 temporal lobectomies. The surgical candidates were selected from 142 patients who met the initial criteria, and passed the initial evaluation for surgical intervention. Forty-five patients had long-term intracranial EEG recording, and circumscribed organic lesions were disclosed in 27 patients by neuroimaging techniques. The outcome of 23 patients who were followed for 2 years postoperatively was complete freedom from complex partial seizures in 17 patients (74%) and an increase in full employment from 2 to 10 patients. Despite the possible surgical complications, including detrimental effects on the higher cerebral functions, it is essential that the surgical treatment of epilepsy should be established as a part of the comprehensive care program. Our experiences and analyses of the state of the art in surgical intervention also suggest that surgical indications for more intractable patients whose social adjustment is less hopeful should be established and the surgical care system for these patients should also be planned. Furthermore, some patients may be free from recurrent seizures postoperatively, but still have difficulties in social rehabilitation. The problems for such patients remain unsolved.

Adult↗
PubMed1990

Subtypes of temporal lobe epilepsies: a clinical point of view.

We studied 40 patients with temporal lobe epilepsies who had long-term intracranial EEG recordings and temporal lobectomies. They were divided into 3 groups on the basis of the anatomical site of seizure origin. An electrode implantation technique combined intracerebral depth electrodes with subdural strip electrodes. The seizures were of amygdalo-hippocampal origin in 18 patients, lateral temporal in 13 patients, and temporo-basal in 9 patients. The clinical and EEG features were reviewed retrospectively with regard to 3 factors in each patient: localization of interictal spikes in the scalp-recorded EEG, signal symptoms (auras), and presumed etiologies. Epilepsy with amygdalo-hippocampal and lateral temporal seizures was found to be distinguishable by the electroclinical features. It seems practical to classify these 2 subtypes of temporal lobe epilepsies as in the 1989 Classification of Epilepsies and Epileptic Syndromes. Temporal lobe epilepsies thus defined can be regarded as epileptic syndromes rather than a cluster of seizure manifestations.

Adolescent↗
PubMed1990

[A case of Legionnaires' disease, the first case in Hokkaido Prefecture--an experience of isolation of Legionella pneumophila and identification by indirect immunofluorescence antibody method].

Although 18 cases of Legionnaires' disease have been reported in Japan, these have included none from the northern areas of Japan. The first confirmed case of Legionnaires' disease in Hokkaido district, a northern island of Japan, is reported. A 48 year-old male was admitted for fulminant pneumonia, and died the next day. Legionella pneumophila, serogroup 1, was cultured and determined from the sputum and lung tissue obtained at autopsy. Postmortem examination by means of the indirect immunofluorescent method, using group specific antisera against Legionella pneumophila as a primary antibody, revealed phagocytized bacilli in the alveoli of the lung.

Fluorescent Antibody Technique↗