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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 847 records · Page 47Linked to original sources
PubMed1976

Characterization of the fragments obtained by enzymic and alkaline degradation of rice-bran proteoglycans.

Repeated digestion of the proteoglycan B from rice bran with Pronase and hemicellulase yielded two types of glycopeptides. The first group, obtained from the third enzymic digest, was a type of low molecular-weight glycopeptide and was fractionated into two subfractions by paper electrophoresis. The second group, obtained from the fourth enzymic digest, was a mixture of glycopeptides of relatively high molecular-weight and was fractionated into three subfractions by gel filtration on Sephadex G-75. Alkaline degradation of these glycopeptides or the intact proteoglycan A yielded a sugar-amino acid compound, whose structure was established as O-alpha-L-arabinofuranosyl-hydroxyproline. These results indicate that the carbohydrate-protein linkage of the rice-bran proteoglycan is an O-glycosyl linkage between L-arabinose and hydroxyproline.

Amino Acids↗
PubMed1976

Purification and properties of the extracellular dextransucrase from Leuconostoc mesenteroides NRRL B-1299.

Dextransucrase [EC 2.4.1.5] activity from cell-free culture supernatant of Leuconostoc mesenteroides NRRL B-1299 was purified by (NH4)2SO4 fractionation, adsorption on hydroxyapatite, chromatography on DEAE-cellulose and gel filtration on Sephadex G-75. The extracellular enzyme was separated into two principal forms, enzymes I and N, and the latter was shown to be an aggregated form of the protomer, enzyme I. Enzymes I and N were both electrophoretically homogeneous and their relative activities reached 820 and 647 times that of the culture supernatant, respectively. On sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis, enzyme N dissociated into the protomer enzyme I, with a molecular weight of 48,000. Enzyme I was gradually converted into enzyme N upon aging, and this conversion was stimulated in the presence of NaCl. The optimum pH and temperature of enzyme I activity were pH 6.0 and 40 degrees, respectively, while those of enzyme N were pH 5.5 and 35 degrees. The Km values of enzymes I and N were 13.9 and 13.1 mM, respectively. Ca2+, Mg2+, Fe2+, and Co2+ stimulated the activity of enzyme N, and EDTA showed a potent inhibitory effect on this enzyme. Moreover, the activity of enzyme N was more effectively stimulated by exogenous dextrans as compared with enzyme I.

Cations, Divalent↗
PubMed1976

Studies on cathepsins of rat liver lysosomes. III. Hydrolysis of peptides, and inactivation of angiotensin and bradykinin by cathepsin A.

Systematic analysis of the hydrolysis of benzyloxycarbonyl (Cbz)-dipeptides by cathepsin A [EC 3.4.12.1] purified from rat liver lysosomes showed that multiple forms of cathepsin A preferentially cleave peptide bonds with leucine, methionine, and phenylalanine. Cbz-Met-Met, -Met-Phe, -Phe-Met, and -Phe-Ala were hydrolyzed 6 to 8 times faster than the standard substrates, Cbz-Glu-Phe and Cbz-Glu-Tyr. The pH optima of the hydrolyses were 4.6 to 5.8. Hydrolysis of peptide bonds with glycine, isoleucine, and proline was very slow, but the rate depended on the nature of the adjacent amino acids. Proteins such as albumin, cytochrome c, gamma-globulin, hemoglobin, histone, myoglobin, and myosin were scarecely degraded. Peptide hormones, such as glucagon and adrenocorticotropic hormone (ACTH) were hydrolyzed markedly with optimum pH's of 4.5 and 4.6, respectively. Angiotensin I, II, bradykinin, Lys- and Met-Lysbradykinin (kallidin and Met-kallidin), and substance P were also hydrolyzed at appreciable rates. pH optima for these peptide hormones were 5.2 to 5.6. On the other hand, insulin and its A chain, luteinizing hormone-releasing hormone (LH-RH), oxytocin and vasopressin were cleaved slowly. In the hydrolyses of glucagon and other peptides, multiple forms of rat liver lysosomal cathepsin A again showed a carboxypeptidase nature, cleaving peptide bonds sequentially from the carboxyl terminal. Almost all of the amino acids were cleaved on prolonged incubation. Vaso-activites of angiotensin II and bradykinin were rapidly lost on hydrolysis by cathepsin A. Lysosomal cathepsin C [dipeptidylaminopeptidase I, EC 3.4.14.1] also activated angiotensin II, but did not inactive bradykinin. Cathepsin A, therefore, can be regarded as one of the lysosomal angiotensinases and kinases. No distinct differences were observed between the multiple forms of cathepsin A in these hydrolyses and inactivations of peptides.

Adrenocorticotropic Hormone↗
PubMed1976

Water stress, rapid polyribosome reductions and growth.

Measurements of the water status of various plant tissues exposed to differing levels of salts for 1 hour were made using the recently developed Campbell J-14 press (Logan, Utah). Values obtained with the press were found to correlate well with estimates of relative water content, and experiments with 3-day-old pumpkin seedlings showed that detectable changes in press values of cotyledon tissues could be obtained within 5 minutes following salt- or desiccation-induced stress.Polyribosome levels were measured in tissues from various plant species following short duration water stress. A small reduction in polyribosome percentage was obtained in cotyledons of 3-day-old pumpkin seedlings which were exposed to an osmotic potential (NaCl) of -4 bar for 10 minutes, but more pronounced changes were found after 30 minutes of stress. Shoot tissues of peas, barley, wheat, and safflower following 20- or 30-minute salt- or desiccation-induced stress yielded extracts with reduced polyribosome levels; however, 30 minutes of exposure of cotton and pumpkin seedlings to -6 bars did not result in altered polyribosome percentage of extracts from roots. Studies using shoot tissues from pumpkins and peas showed that polyribosome percentages and growth rates of both plants were reduced in proportion to loss of tissue water. These plants differed in their sensitivity to stress in that polyribosome content and growth rate reductions were both nearly twice as severe per unit of water loss in peas as in pumpkins. These data along with those obtained by others suggest that growth rate reductions may be directly proportional to reductions in polyribosome levels during water stress.

Journal Article↗
PubMed1976

New device for automatic recording and processing AV transmission intervals of the heart.

The principle and construction of a device made for the purpose of displaying the interrelationship between two sets of cardiac intervals is described. Electrical signals derived from the atrium and ventricle of the experimental animal are fed to the input of the device where a special switch and an integrated circuit logic gate select the two sets of cardiac intervals to be measured, e.g., AA and VV or AA and AV intervals. These intervals are converted into electrical square pulses having voltages proportional to the respective intervals. Besides simply comparing the two cardiac intervals by recording them simultaneously against time, the interrelationship of the two is displayed in an X-Y configuration on-line on a cathode-ray oscilloscope. This latter method, if used only for the occasionally induced premature excitations with varied coupling time, facilitates the measurement of the functional refractory periods for atrioventricular conduction. The mode of operation of the device is presented with examples of experiments.

Animals↗
PubMed1976

Insulin and glucagon response in patients with chronic pancreatitis.

The oral glucose tolerance test and arginine infusion test were carried out on 22 patients with chronic pancreatitis and 11 normal control subjects. According to the glucose tolerance curve, the patients were divided into three groups; group I (normal or slightly impaired), group II (mildly diabetic) and group III (moderately diabetic). Markedly impaired insulin responses to oral glucose as well as to arginine infusion were observed in groups II and III. In group I, the mean plasma insulin levels during glucose tolerance test were the same as those in the controls, but the insulin response to arginine was reduced except in two cases. On the other hand, the glucagon levels during arginine infusion test were within the normal range in group I and slightly reduced in the other groups with diabetic glucose tolerance. The ratio of increment area of insulin to that of glucagon during arginine infusion in the patients was slightly decreased in comparison with the controls. Neither insulin nor glucagon response after arginine infusion showed a significant correlation with pancreatic exocrine function. It is concluded that in chronic pancreatitis insulin response to glucose as well as to arginine is markedly decreased, and that glucagon rise after arginine infusion is lowered compared with the controls.

Adolescent↗
PubMed1976

Susceptibility of chickens to avian encephalomyelitis virus. II. Behavior of the virus in day-old chicks.

The VR strain of avian encephalomyelitis virus, which had been adapted to embryonated hen's eggs, was inoculated into 2-day-old chicks by the subcutaneous route (10(2.5) approximately 10(3.0) EID50) or by the oral route (10(4.8) EID50). The chicks were examined chronologically for the distribution of the virus in the body. As a result, minute amounts of the virus were detected from the liver, spleen, pancreas, and muscle at the site of inoculation one day after inoculation and various amounts from almost all the organs 3 days and more after inoculation. The virus titer could nearly reach a maximum 7 to 9 days after inoculation. Above all, such high virus titers as ranging from 10(4.3) to 10(5.8) EID50/0.1 g were demonstrated in the brain, heart, liver, spleen, and pancreas. After that, there was a tendency for virus titer to decrease in most organs and for virus to multiply persistently in the pancreas, brain, and eyeball. Virus titer was maintained at a level of 10(2.3) approximately 10(2.8) EID50/0.1 g in these three organs even 21 days after inoculation. In the group of subcutaneous inoculation, all the chicks manifested clinical signs of infection 5 to 10 days after inoculation. On the other hand, no chicks were involved in clinical infection in the group of oral inoculation. Multiplication of the virus was delayed in the body of these chicks. Small amounts of the virus were detected from the spleen and pancreas 11 days after inoculation. Low titers (10(2.7) EID50/0.1 g at the highest) of the virus were only detected from the brain, spinal cord, spleen, pancreas, esophagus, and other organs 14 and 21 days after inoculation.

Administration, Oral↗
PubMed1976

Susceptibility of chickens to avian encephalomyelitis virus. III. Behavior of the virus in growing chicks.

A chick embryo-adapted strain of avian encephalomyelitis virus was inoculated subcutaneously and orally into 40-day-old (middle-aged) and 110-day-old (advanced-aged) chicks to examine the behavior of the virus in the chick body. In the middle-aged chicks, the virus appeared in the muscle at the site of inoculation, liver, spleen, pancreas, lumbar and cervical portions of the spinal cord, and brain 1 approximately 9 days after subcutaneous inoculation, and remained mostly in the central nervous system up to 17 days after the inoculation. The virus was found in large amounts in the muscle at the site of inoculation (10(3.1)), lumbar portion (10(2.5)) and cervical portion (10(2.1)) of the spinal cord, brain (10(1.9)), and in minute amounts in the other organs examined. It appeared in 11 of 21 organs examined. In the middle-aged chicks inoculated by the oral route, the virus was detected transiently in small amounts from esophagus, pancreas, and rectum 4 approximately 14 days after inoculation. In the advanced-aged chicks inoculated by the subcutaneous route, the virus was detected in titer of 10(2.1) approximately 10(3.0) from the muscle at the site of inoculation 2 approximately 7 days after inoculation. The virus was also found sporadically in several organs up to 17 days after inoculation. In the advanced-aged chicks inoculated by the oral route, no virus appeared in any organ, but these chicks turned to be weakly positive for neutralizing antibody in the 4th or later week after inoculation.

Animals↗
PubMed1976

Susceptibility of chickens to avian encephalomyelitis virus. IV. Behavior of the virus in laying hens.

Some laying hens 6 months of age were inoculated subcutaneously or orally with a chick embryo--adapted strain of avian encephalomyelitis virus and examined for propagation of the virus in the body. When inoculated subcutaneously, the virus appeared in liver, spleen, ovarian follicle, and muscle at the site of inoculation 1 day, in kidney and lumbar part of the spinal cord 3 days, in the pancreas 5 days, in heart, duodenum, and cervical part of the spinal cord 7 days, and in the brain 11 days after inoculation. After its appearance, it increased gradually in amount in liver, spleen, pancreas, muscle at the site of inoculation, and cervical and lumbar parts of the spinal cord, but remained at a low level in any other organ. When examined 14 days after inoculation and later, it was distributed mainly in the central nervous system. It was detected from 12 of 16 organs examined. The highest virus level in each organ was 10(2.6)/0.1 g in pancreas and lumbar part of the spinal cord, which were followed by muscle at the site of inoculation (10(2.0)/0.1 g), spleen (10(1.8)/0.1 g), cervical part of the spinal cord, heart, and liver in the order listed. When inoculated orally, the virus was found sporadically in spleen, pancreas, kidney, cecum, ovarian follicle, and lumbar part of the spinal cord. The virus level was low in these organs, of which pancreas, kidney, and lumbar part of the spinal cord showed the highest virus level, or 10(1.3)/0.1 g.

Administration, Oral↗
PubMed1976

Susceptibility of chickens to avian encephalomyelitis virus. V. Behavior of a field strain in laying hens.

Some 12-month-old laying hens were inoculated orally or subcutaneously with 10(4.7) EID50 of a field strain of avian encephalomyelitis virus. They were examined for propagation of the virus in the body at regular intervals of time. When two hens were sacrificed daily in the group of oral inoculation, the virus was found in liver, pancreas, and esophagus in both hens 1 day, in brain, lumbar part of the spinal cord, heart, spleen, pharynx, larynx, glandular stomach, muscle, and blood in one of the two hens 1 day, and in various parts of the body 3 approximately 9 days after inoculation. After that, the virus was detected almost continually from the central nervous system and abdominal parenchymatous organs in nearly all the hens examined up to the end of the observation period, or 21 days after inoculation. Virus detection from the digestive tract and ovarian follicle, however, decreased in frequency and virus titer was reduced remarkably with the lapse of time after inoculation. When the largest amount of virus was determined in each organ, it was the largest, or 10(6.5) EID50/0.1 g, in the liver and about 10(5.0) EID50/0.1 g in spleen, pancreas, kidney, and ovarian follicle. There was little difference in virus propagation and its course between the group of subcutaneous inoculation and that of oral administration.

Administration, Oral↗
PubMed1975

Purification and characterization of two activities of the intracellular dextransucrase from Leuconostoc mesenteroides NRRL B-1299.

Dextransucrase (sucrose: 1,6-alpha-D-glucan 6-alpha-glucosyltransferase EC 2.4.1.5) activity of Leuconostoc mesenteroides NRRL B-1299 cells has been purified by adsorption on hydroxyapatite, followed by chromatographies on DEAE-cellulose and DEAE-Sephadex. The enzyme activity was readily separated into two principal forms of the enzyme, I and II, by DEAE-cellulose chromatography. Both enzymes I and II were purified to an electrophoretically homogeneous state in which the relative enzyme activities reached 32-and 14-fold of the original specimen, respectively. Molecular weights were 69 000 for the enzyme I and 79 000 for the enzyme II as determined by electrophoresis in sodium dodecyl sulphate-polyacrylamide, and no subunit structure was observed. Enzyme I had an optimum pH at 6.3-6.5 and exhibited a maximal activity at 45 degrees C, while the optimum pH and temperature of enzyme II were pH 5.5-5.9 and 35-40 degrees C. The Km values of enzymes I and II were 10.7 and 250 mM, respectively. The effects of several metal ions, chemical reagents, and addition of various dextrans were also examined. Beside linear alpha-1,6-linkages the polymer synthesized by the enzyme II contained lesser amount of alpha-1,2-and alpha-1,3-linkages, which seems to be a primary characteristic of the B-1299 dextran.

Chromatography↗
PubMed1975

On the water-soluble heterogalactan from the fruit bodies of Lentinus edodes.

The chemical structure of a heterogalactan isolated from the trichloracetic acid extract of the fruit bodies of Lentinus edodes is reported. It consists of a main chain of (1 yields 6)-linked alpha-D-galactopyranose residues, part of which are substituted in the 2-position either with single L-fucopyranose or D-mannopyranose residues. However, there is a possible alternative structure of a branched D-galactan in which most of the side-chains are terminated with L-fucose or D-mannose residues.

Basidiomycota↗
PubMed1975

Glucagon-induced insulin secretion in normal diabetic subjects.

Eight normal subjects and ten diabetic patients were studied to compare the response of plasma insulin to glucagon with that to glucose and tolbutamide. Oral glucose tolerance test, glucagon test and tolbutamide-glucagon test were performed at intervals of several days. In glucose tolerance test, insulin response was reduced in the patients with severe diabetes. Plasma insulin increased and reached the peak 3 min after glucagon injection (glucagon I) in the normal controls, while plasma insulin response was reduced in diabetic patients, especially in the severe diabetics. In the normal controls plasma insulin rose and reached the peak 6 min after the tolbutamide injection and thereafter fell to the initial level. Glucagon injection following tolbutamide (glucagon II) caused the rise in insulin in the control subjects. In diabetics insulin response to either tolbutamide or glucagon I was reduced. Tolbutamide or glucagon II caused a significant difference in plasma insulin response in all the diabetic groups compared with the normal subjects, while glucose or glucagon I showed a significant increment of plasma insulin between the normal subjects and the severe diabetics. These results suggest that injection of tolbutamide as well as glucagon II provides a definite discrimination of insulin response in diabetics from the normal controls. The usefulness of the tolbutamide-glucagon test in the diagnosis of diabetes mellitus was discussed. -- glucose tolerance test; glucagon test; tolbutamide-glucagon test; plasma insulin.

Administration, Oral↗