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Biomedical subjects

T Toyota

Publications and source records attributed to T Toyota.

At least 343 records · Page 19Linked to original sources
PubMed1985

Discrimination between cardiac para- and sympathetic damage in diabetics.

To analyze the autonomic mechanism on heart rate (HR) variations, pharmacological studies were performed on 8 healthy subjects and 6 diabetic patients. Three HR variations--in supine resting position, during deep breathing in supine position (respiratory HR variations), and on standing (orthostatic tachycardia; delta HR)--were examined. The results in healthy subjects and diabetics were similar. After administration of parasympathetic blockade with atropine, respiratory HR variations were almost abolished. However, no significant difference in delta HR was found. With the addition of beta-adrenergic blockade with propranolol, delta HR was remarkably reduced. Propranolol alone did not affect the respiratory HR variations, but after propranolol administration delta HR was significantly reduced compared with that of the control. The present studies show that respiratory HR variations are predominantly mediated by parasympathicus, whereas orthostatic tachycardia is mediated by both sympathicus and parasympathicus, particularly by sumpathicus. This result suggests the possibility of discriminating the impairment of the 2 cardiac autonomic nervous systems by these simple and non-invasive tests.

Adult↗
PubMed1985

Quantitative evaluation of diabetic autonomic neuropathy by using heart rate variations--determination of the normal range for the diagnosis of autonomic neuropathy.

Heart rate (HR) variations--in supine resting position, during deep breathing and on standing--were measured in 162 healthy subjects and 168 diabetics by use of an instantaneous-HR-change continuous recorder. As indices of HR variations, the standard deviation of the HR at rest (SD of HR), the mean difference between maximal and minimal HR during deep breathing (delta I-E) and the HR increase on standing (delta HR) were determined. In healthy subjects, the values for each test declined with age and the log-transformed data fitted the linear regression. The 90% confidence limits were calculated for the normal range and the values below normal range were defined as abnormal. In diabetics, the incidence of abnormal response were 19% in the SD of HR, 38% in the delta I-E and 22% in the delta HR. The delta I-E was the most sensitive index for the autonomic neuropathy. The delta HR was considered to be able to detect the different mechanisms of neural reflexes because of the poor correlation between the delta HR and the respiratory HR variations. The present studies suggested that delta I-E and delta HR should be measured at the same time to evaluate the autonomic neuropathy.

Adolescent↗
PubMed1985

Expression of receptors for Fc portion of IgM (Fc mu . R) and surface neuraminic acid on the human peripheral lymphocytes.

The purpose of this investigation is to establish a method of quantitation of sialic acid on the lymphocyte membrane surface and to clarify the importance of sialic acid in the functional manifestation of the lymphocyte receptor for the Fc portion of IgM (Fc mu . R) as well as the cell surface. The experiments yielded results leading to the following conclusions: Cell surface sialic acid can be exclusively recovered at consistent rates by treatment of lymphocytes with 0.1 IU of neuraminidase in the presence of Ca++ at 37 degrees C for 30 min. The sialic acid obtained, though in minute quantities, was accurately quantitated by the TBA method. By these procedures, the amount of sialic acid present on the cell membrane of human peripheral blood lymphocytes was determined to be 2.46 micrograms/10(7). Surface sialic acid on lymphocytes cultured at 37 degrees C after treatment with neuraminidase was resynthesized sufficiently at about 6 hr. On the cell membrane of lymphocytes deprived of Fc mu . R by treatment with neuraminidase, the receptor for IgM Fc became redetectable following incubation of the cells at 37 degrees C; the time-course of redevelopment of Fc mu . R showed a striking coincidence with that of sialic acid resynthesis. A sufficient redevelopment of Fc mu . R occurred in 6 hr of incubation of neuraminidase-treated Fc mu . R-deprived lymphocytes; the time required for sufficient redevelopment was comparable to that reported for pronase-treated lymphocytes. It is concluded from these findings that Fc mu . R deprived of sialic acid is no longer repaired while the receptor is resynthesized de novo on incubation of lymphocytes under adequate conditions.

Cell Membrane↗
PubMed1985

ApoE-2/E-3 ratio of very low density lipoprotein in diabetes mellitus.

Apolipoprotein E (apoE) of very low density lipoprotein (VLDL) in 22 diabetic patients was analysed by the method of one-dimensional isoelectrofocussing (IEF). We modified the IEF-method of Kashyap et al. by which apoE isoproteins were easily and accurately determined. The measurement of apoE-2/E-3 ratio was useful for determining apoE phenotypes. In 17 of 22 diabetics apoE phenotype was E3/3, while three patients showed E2/3 and two showed E3/4. ApoE-2/E-3 ratio was reduced from 0.91 +/- 0.07 to 0.73 +/- 0.04 (p less than 0.05) by the one month-period treatment in 10 insulin required diabetics. The ratio was also reduced from 1.06 +/- 0.14 to 0.89 +/- 0.09 (p less than 0.2) in 10 non-insulin required diabetics. The reduction in apoE-2/E-3 ratio was caused by an increase in apoE-3 band and a decrease in apoE-2 band which might be attributed to the changes in the sialic acid-content of isoproteins on the one-dimensional IEF method. Therefore, apoE phenotypes in diabetic patients should be determined when their diabetic state is improved.

Adult↗
PubMed1985

Continuous subcutaneous insulin infusion therapy in Japan, 1984: a survey by questionnaires.

A country-wide survey of the continuous subcutaneous insulin infusion (CSII) therapy was carried out in the summer of 1984 in Japan. Questionnaires were mailed to doctors of 456 diabetes clinics and other questionnaires were distributed to patients taking CSII therapy by salesmen of the infusion pump makers. 275 doctors and 86 patients responded to the questionnaires. CSII therapy was conducted in 110 clinics (40%), but it was done mostly in inpatients. Decrease in blood glucose (91%) and improvement of general body condition (65%) were achieved by the therapy, but cutaneous complications, such as skin reaction to the tapes (33%), pigmentation (46%), induration (35%) and lipodystrophy, and hypoglycemic (83%) or ketoacidotic (16%) episodes were experienced in many cases. 211 doctors predicted bright prospects for the CSII therapy, 86 (41%) speculated a spread in the popularity of the therapy and 44 (21%) opined that the therapy was a passing phenomenon (only a fashion).

Adult↗
PubMed1984

A putative second messenger of insulin action regulates hepatic microsomal glucose-6-phosphatase.

Physiological concentrations of insulin suppressed rat liver microsomal glucose-6-phosphatase activity in vitro. To attest a hypothesis that a putative second messenger of insulin action (insulin mediator) mediated this process, we isolated the low molecular factor from insulin-treated plasma membranes of rat liver, which was acid- and heat-stable substance of a peptide nature. The insulin mediator which was proved to activate the mitochondria pyruvate dehydrogenase suppressed microsomal glucose-6-phosphatase. The insulin mediator was linked to suppression of the gluconeogenic enzyme through the control of non-specific phosphohydroxylase.

Animals↗
PubMed1984

Partial purification from human mononuclear cells and placental plasma membranes of an insulin mediator which stimulates pyruvate dehydrogenase and suppresses glucose-6-phosphatase.

A substance capable of stimulating pyruvate dehydrogenase (PDH) and suppressing glucose-6-phosphatase (G-6-Pase) in a cell-free system was prepared from insulin-treated human placental plasma membranes and peripheral blood mononuclear cells by formic acid extraction. This material was partially purified by molecular-exclusion chromatography, ion-exchange chromatography, and hydroxylapatite chromatography. This was found to stimulate pyruvate dehydrogenase and inhibit glucose-6-phosphatase in a dose-dependent manner. The amount or ability of this substance to stimulate pyruvate dehydrogenase was increased in the proportion to the concentration of insulin. The stimulation of pyruvate dehydrogenase by the factor was eliminated when sodium fluoride was presented in the assay of the activation. This result implied that the activation of pyruvate dehydrogenase was mediated by the stimulation of the phosphatase of pyruvate dehydrogenase complex. Each material isolated from insulin-treated human placental plasma membranes and mononuclear cells shared a number of important characteristics of putative second messengers of insulin action as follows: (i) heat and acid stability; (ii) a similar molecular weight; (iii) increased activity of pyruvate dehydrogenase in a insulin-dependent manner; and (iv) stimulated pyruvate dehydrogenase by the sodium fluoride-sensitive mechanism. This human putative second messenger of insulin action was eluted from the anion-exchange resin AG1-X8 at an ionic strength of 0.3-0.4 M, as well as from the hydroxylapatite column at a phosphate concentration of 0.2-0.3 M.

Adenosine Triphosphate↗
PubMed1984

Somatostatinoma syndrome accompanied by overproduction of pancreatic polypeptide.

A case of somatostatin and pancreatic polypeptide (PP) producing tumor of the pancreas is presented. A 65-year-old woman was admitted for the evaluation of the tumor in the right upper quadrant of the abdomen. Clinical abnormalities included diabetic glucose intolerance, pancreatic insufficiency and marked dilatation of gallbladder. Marked high concentration of plasma PP and low levels of plasma insulin and glucagon were observed before operation. Plasma insulin concentrations in response to oral glucose tolerance test and arginine infusion were markedly low. A large quantity of somatostatin (4,300 ng/g ww) as well as PP (1,340 ng/g ww) was detected in the tumor, and somatostatin cells and PP cells were determined by immunofluorescence studies. After operation, pancreatic insufficiency and glucose intolerance were improved, and the patient made a favorable progress.

Aged↗
PubMed1983

Diurnal profile of gallbladder size in diabetic patients: ultrasonographic evaluation of diabetic neurogenic gallbladder.

The diurnal change of gallbladder size was clearly measured with a real time ultrasonography. To visualize the gallbladder, 21 diabetic patients and 11 healthy subjects were scanned right subcostally in the supine position nine times between 8:00 a.m. and 8:00 p.m. Photographs of the images were produced on Polaroid film, and the area of gallbladder was calculated. The diurnal changes of the gallbladder size were expressed as the percentage of the size measured at 8:00 a.m. after an overnight fast. The gallbladder in normal control started contracting immediately after breakfast and reached 57.2 +/- 7.6% at 9:00 a.m. In the diabetic patients with and without autonomic neuropathy the gallbladder contracted to 80.9 +/- 14.5% and 72.4 +/- 14.8%, respectively, at 9:00 a.m. while the nadir of the diurnal profile curve in healthy subjects was 24.5 +/- 3.6% at 3:00 p.m., in the diabetic patients with and without autonomic neuropathy those were 57.7 +/- 6.1% at 6:00 p.m. and 41.3 +/- 8.3% at 8:00 p.m., respectively. This implies that the gallbladder contraction was delayed and poor in diabetic patients. In this paper, the gallbladder tonicity index is proposed, which is useful for the easy evaluation of autonomic state of gallbladder in diabetes mellitus.

Adolescent↗