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Biomedical subjects

T Matoba

Publications and source records attributed to T Matoba.

At least 55 records · Page 3Linked to original sources
PubMed1981

Further observations of the digital plethysmography in response to auditory stimuli and its clinical applications.

Further observations of the digital plethysmography with auditory stimuli and its clinical applications were performed in patients with vibration disease and heart diseases. The responsive pattern to the auditory stimuli in the digital plethysmogram could be faithfully reproducible if it elapses more than 5 minutes apart between the first stimulus and the second one. The responsive patterns were divided into four types: normal (N), hyperreactive (I and D) types and hyporeactive (P) type. The values of urinary catecholamine increased in parallel to the activity level of the autonomic nerve. The hyperreactive type (D) had the highest value of urinary catecholamine, and vice versa. With regard to the age, the elderly was prone to show hyporeactive (P) type, and the young tended to be hyperreactive (D) type. Psychologic factors were examined by Cornell medical index. Neurosis was not necessarily related to the hyperreactive type. In clinical applications, it was observed by this method that the autonomic imbalance in patients with vibration disease, angina pectoris, or hypertension was recovered by the treatment, and the abnormal types of the response recovered to N type. In conclusion, the digital plethysmography with auditory stimuli as one of the autonomic nerve function tests would be much useful and non-invasive method for observation of clinical course and decision of the severity.

Adult↗
PubMed1981

The role of cell mediated immunity in coxsackie B viral myocarditis.

The role of cell mediated immunity (CMI) in the pathogenesis of coxsackie B (Cox. B) viral myocarditis in the adult were immunologically investigated. The number of types of neutralizing antibody in patients with Cox. B viral myocarditis was more than that in controls. This fact suggested that these patients had a history of previous Cox. B viral infections. In the patient with Cox. B viral myocarditis, neutralizing antibody titer was increased as 20 folds by the reinfection. And also macrophage migration inhibition test showed that CMI was enhanced not only against the same type but also against the other types of Cox.B group viruses. In conclusion, it may be essential in the occurrence of adult myocarditis that the patient has been infected by Cox.B virus and immunized against the other types as well as the same type of Cox.B group viruses. CMI may also play a critical role in the occurrence of Cox.B viral myocarditis.

Antibodies, Viral↗
PubMed1980

Subunit structure of pig kidney cathepsin A.

The two forms of pig kidney cathepsin A (A,L and A,S) were found to be composed of three kinds of polypeptides as common structural subunits with molecular weights of 20,000, 25,000, and 55,000. [32P]-DFP was incorporated into the subunit with a molecular weight of 25,000. This subunit seems to be a catalytic one, on which active serine is present. A subunit composition ratio of 1 : 1 : 1 in native cathepsin A,S was estimated by its molecular weight and those of the subunits. Native cathepsin, A,L also seems to have a subunit composition ratio of 1 : 1 : 1. These results suggest a monomer-polymer relationship between both enzymes.

Animals↗
PubMed1980

Effects of oral befunolol on heart rate and systolic blood pressure during submaximal exercise in man.

For the purpose of determining exercise intensity required for evaluating the effect of beta-blocking agents, the multi-stage treadmill exercise was carried out up to intensity of 85% of maximal oxygen intake (VO2max) after administration of beta-blocking agents in 7 healthy men. To obtain a stable dose response in the inhibitory effect of beta-blocking agents on heart rate (HR) and systolic blood pressure (S-BP), the exercise intensity more than 65% of VO2max (75% of maximal heart rate) was needed. In order to evaluate the effect of befunolol (BFE), a submaximal treadmill exercise of 75% of the age adjusted predicted maximal heart rate was loaded in 6 healthy men at 1.5, 4, and 8 hours following a single oral administration of 10 mg, 20 mg or 40 mg of BFE and 20 mg or 40 mg of propranolol. Simultaneously, the plasma concentration of BFE was determined 1.5, 4, 6 and 8 hours after the administration of BFE at each dose. In human serum, BFE was detected together with its metabolite, revealing a significant correlation between BFE and metabolite (r = 0.94, p < 0.001). Almost a certain rate of metabolite (4--5 times) was detected against BFE. As for the biological half life, it was 1.79 +/- 0.13 hours with BFE and 3.67 +/- 1.33 hours with metabolite. The inhibitory effect of BFE on HR and S-BP during exercise exhibited a dose response with the oral dose and its plasma concentration, and was almost twice as much as that of propranolol at the same dose. Accordingly, the myocardial oxygen consumption which may be represented as rate pressure product was inhibited twice as much as propranolol. BFE is characteristic of its more rapid elimination of its effect compared to the other beta-blocking agents. The decrease in the inhibitory effect of BFE or HR during exercise was about 1.8 times quicker than that of propranolol.

Administration, Oral↗
PubMed1979

Changes of ventricular monophasic action potential duration by stellate ganglion stimulation in dogs.

Left or right stellate ganglion stimulation resulted in changes of ST segments and T waves of electrocardiogram. The present experiments were performed in an attempt to elucidate alpha-and beta-adrenergic actions, and calcium action on the monophasic action potential duration (APD), that is, the repolarizing phase of myocardium. During experiments in open-chest dogs, right ventricular pacing was performed for avoiding the acceleration of heart rate by stellate ganglion stimulation. Administration of phentolamine, propranolol or D600 prolonged APD, while hydrazine shortened it. However, stellate ganglion stimulation caused a prolongation of APD after infusion of propranolol or hydrazine, and a shortening of APD after infusion of phentolamine, D600 or hydrazine. These results indicate that alpha-and beta-adrenergic actions as well as calcium ions can be related to APD in the ventricular myocardium of dogs; apparently, alpha-adrenergic action prolongs APD and beta-adrenergic action shortens it.

Action Potentials↗
PubMed1978

Rat renin: purification and characterization.

In order to clarify the molecular basis of the unique features of rat renin (EC 3.4.99.19) and to provide materials and basic information for high blood pressure studies in rats, renin was purified from rat kidney. The final step of purification on CM-cellulose separated renin into three major isoenzyme peaks, R-I, R-II, R-III, and an additional minor peak. These preparations were judged homogeneous by multiple criteria, and the isoenzymes were found to have similar amino acid compositions. The amino acid composition is also closely analogous to hog renin, except that rat renin has a higher cysteine content. In contrast to hog renin, the rat enzymes do not contain amino sugars, yet are apparently glycoproteins as judged by their affinity for concanavalin A. The molecular weights of R-I, R-II, and R-III were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 37 000, 36 000 and 35 000, respectively. The isoelectric points were 5.05, 5.15 and 5.22, respectively. The specific activities of the purified enzymes (determined using rat plasma as substrate) were 615, 626 and 452 Goldblatt units/mg, respectively. Comparison of activities with the hog- and rat-derived substrates indicated a preference for that from the rat. The reaction of the rat enzymes with a synthetic peptide substrate had a similar catalytic rate constant to the hog enzyme, indicating close similarity in the active site region of the two enzymes.

Animals↗
PubMed1977

Native form of renin in the kidney.

Renin (EC 3.4.99.19) has been observed to exist in a high molecular weight (Mr greater than 50,000) and a low molecular weight from (Mr approximately 42,000) in various tissues. Little is known concerning the origin and function of the high molecular weight form of renin and its relationship to low molecular weight renin. We have found that the high molecular weight form of renin in the kidney was converted to the low molecular weight form during the extraction process. The conversion is apparenly catalyzed by an agent(s) which requires free sulfhydryl groups since blockers of sulfhydryl groups completely suppress the conversion. This conversion could not be prevented by various specific inhibitors of serine proteases nor by the metal chelator EDTA. By the use of Na-tetrathionate it was possible to preserve the renin activity of hog kidney exclusively in the high molecular weight form. Similarly, using N-ethylmaleimide it was shown that a similar high molecular weight form of renin is the exclusive form present in rat kidney. These results suggest that the high molecular weight form of renin is the native form stored in the kidney and that it is converted by an enzyme or agent requiring sulfhydryl groups to the circulating (low molecular weight) form when it is secreted into blood. Renin activity was increased to approximately 155% of the original level upon conversion.

Animals↗
PubMed1977

Substrate specificities of cathepsin A,L and A,S from pig kidney.

The substrate specificities of two different molecular sizes of cathepsin A, A,L (large form) and A,S (small form), for synthetic substrates were examined kinetically. Both enzymes showed a similar broad substrate specificity against various acyl dipeptides, amino acid esters, and amino acid amides. Z-Phe-Ala and Ac-Phe-OEt were good substrates. Peptides containing hydrophobic amino acids were hydrolyzed rapidly. The presence of hydrophobic amino acid residues, not only at the C-terminal position but also at the second position and probably the third position from the C-terminal, resulted in an increase in the rate of hydrolysis. Peptides containing glycine and proline were hydrolyzed slowly. Inhibition studies with Z-D-Phe-D-Ala and Z-Phe suggested that the peptidase and esterase activities of the enzymes are both catalyzed by the same site of the enzyme molecule, but it remains to be elucidated whether or not the binding sites for peptides and esters are the same.

Alanine↗
PubMed1977

Clinical features and laboratory findings of vibration disease: a review of 300 cases.

Clinical features and laboratory findings of 300 inpatients with vibration disease before and after treatments were reviewed. Having been using chain saws or pneumatic hammers for a long period, the patients were afflicted with Raynaud's phenomenon, numbness, pain or stiffness of fingers, pain of elbows and neck, stiffness of shoulders and lumbago. They had high incidences of complaints due to the disorder of the central nervous system, especially of the higher center of the autonomic nervous system; i.e. headache (52.0%), palmar hyperhidrosis (70.0%), forgetfulness (78.2%), fatiguability (61.3%), tinnitus (41.8%), impotence (55.1%), etc. Laboratory findings of the autonomic nerve activity tests, electroencephalograms and audiograms also suggested the disorder of the central nervous system. Treatments during three months had improved significantly the subjective symptoms and the objective findings (p less than 0.05 to 0.001). Thus, vibration disease should be considered as a systemic disease, including disorders of the central nervous system, especially of the higher center of the autonomic nervous system, and disturbances of the peripheral functions.

Capillaries↗
PubMed1977

Comparative double-blind trial of dl-alpha-tocopheryl nicotinate on vibration disease.

Sixty inpatients with vibration disease were examined on the effect of dl-alpha-tocopheryl nicotinate by comparative double-blind study. The observed period was 6 weeks and the dose was 6 capsules a day (600 mg as dl-alpha-tocopheryl nicotinate, Juvela Nicotinate, referred to as EN). The physical exercise therapy was applied to all patients throughout the test period. EN group became better with a significant difference from P (placebo) group in the subjective symptoms, the clinical examinations and the collective improving rate (p less than 0.01, 0.05, 0.01), respectively. The improvement of the subjective symptoms of both groups was higher 6 weeks than 3 weeks after administration. Most items in EN group became better significantly (p less than 0.05) as compared with those in P group. The examinations of the peripheral functions in EN group showed a significant improvement 6 weeks after administration in comparison with those in P group. Blood chemistry, blood cell counts and serum electrolytes changed within normal range. Thus, this preparation would be a curative agent for patients with vibration disease.

Clinical Trials as Topic↗
PubMed1975

Purification and some properties of cathepsin A of small molecular size from pig kidney.

Cathepsin A [EC 3.4.2.-] of small molecular size (cathepsin A, S) has been purified about 800-fold from pig kidney by procedures including chromatographies on DEAE-Sephadex, SP-Sephadex, and Sephadex G-150. 1. The homogeneity of the purified enzyme was proved by ultracentrifugation and polyacrylamide gel electrophoresis. The molecular weight (100,000) and isoelectric point (pI=5.0) were estimated. 2. The enzyme was remarkably stabilized by sucrose and KCl, and was most stable at pH 5-5.5 in the presence of both stabilizers. The enzyme had not only peptidase activity but also esterase and amidase activity; it was optimally active at pH 5.2 for peptide hydrolysis and at pH 8 for the hydrolysis of esters and amides. 3. Diisopropyl fluorophosphate and iodoacetamide completely inhibited these three activities. 4. The enzyme hydrolyzed various benzoyl- and benzyloxycarbonyl-dipeptides with neutral, acidic, and basic amino acids, and proline in the C-terminal position. The carboxypeptidase nature of the enzyme was proved by its action on an oligopeptide. 5. Several enzymatic properties of cathepsin A, S were almost the same as thoas of cathepsin A of large molecular size (cathepsin A, L) and the crude homogenate.

Animals↗
PubMed1975

Digital plethysmographic responses to auditory stimuli in patients with vibration disease.

Digital plethysmographic responses to auditory stimuli in 15 healthy men and 82 patients with vibration disease were analyzed in order to clarify the functional conditions of autonomic nervous system in this disease. The auditory stimuli given to healthy men caused a rapid decrease in the amplitude of the plethysmograms. After cessation of the auditory stimuli the decreased amplitude recovered to the control value within 30 sec. In the patients with vibration disease, however, the recovery of the decreased amplitude was delayed. The plethysmographic changes in the patients with vibration disease were divided into 4 types: normal (N), intermediate (I), delayed (D) and poor response (P) types. Each type of I, D and P was altered to type N by treatments consisting of therapeutic exercises, hot spring cures and so on. All healthy men showed type N. There were no significant differences between the time courses of the recovery of the plethysmographic changes and the amplitudes of the plethysmograms before the auditory stimuli. The results obtained seem to indicate that the autonomic nervous system in the patient with vibration disease is in disorder, and that the digital plethysmography with auditory stimuli is instrumental to detect the functional changes in the autonomic nervous system.

Acoustic Stimulation↗
PubMed1975

Substrate specificity of carboxypeptidase from Watermelon.

The substrate specificity of carboxypeptidase (F-II) purified from watermelon for various synthetic peptides and esters was examined kinetically. The enzyme showed a broad substrate specificity against various carbobenzoxy- and benzyl-dipeptides. Peptides containing glycine or proline were hydrolyzed slowly by the enzyme. Peptides containing hydrophobic amino acids were hydrolyzed rapidly. The presence of hydrophobic amino acid residues, not only at the C-terminal position but also at the second position and probably the third position from the C-terminal resulted in an increase in the rate of hydrolysis. Inhibition studies with diisopropyl flurophosphate and diastereomers of carbobenzoxy-Phe-Ala demonstrated that the peptidase and esterase activities of the enzyme are both catalyzed by the same site of the enzyme molecule, but the binding sites for peptides and esters seem not to be the same. The enzyme also had amidase activity, which was optimal at pH 7.0.

Amidohydrolases↗