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Biomedical subjects

Y Goriya

Publications and source records attributed to Y Goriya.

36 records · Page 2Linked to original sources
PubMed1979

The development of an artificial beta cell system and its validation in depancreatized dogs: the physiological restoration of blood glucose homeostasis.

An instrument for the control of blood glucose in a closed-loop fashion has been developed. This artificial beta cell consists of 4 subunits: a Glucose Monitor, a Microcomputer, an Insulin Infusion Pump and a Printer. Its internal control algorithm was derived from the modeled dynamics of glucose-induced insulin secretion, and includes the effects of both the proportional and derivative actions of blood glucose concentration, and is expressed as: IIR = Kp . BG + Kd . deltaBG + Kc, where IIR is insulin infusion rate, BG and deltaBG are blood glucose concentration and rate of change in glycemia, respectively. Kp and Kd are individual coefficients and Kc is a constant of basal insulin secretion. The performance of this system was studied with various kinds of glucose challenges on anaesthetized depancreatized dogs. Its notable characteristics were: 1) the insulin infusion rate was such as to maintain physiological insulin levels, and 2) dextrose or glucagon infusions were not required.

Animals↗
PubMed1979

Counterregulatory system in an artificial endocrine pancreas. Glucose infusion algorithm.

An artificial endocrine pancreas has been developed by adding a glucose infusion system to the artificial beta cell system. In this computer algorithm, glucose is infused on the basis of proportional and derivative actions to blood glucose concentration with the time delay constant between blood withdrawal and initiation of glucose infusion. When glucose was infused on the basis of proportional action with a 20-minute time delay, the prompt restoration to normoglycemia from the hypoglycemic state with a smaller amount of glucose was shown in depancreatized dogs. These results indicate that the artificial endocrine pancreas thus prepared is not only a useful device to safely control blood glucose, but also is an efficient research tool for the analysis of the blood glucose regulatory mechanism.

Animals↗
PubMed1979

An open-loop insulin delivery device for the control of experimental diabetes.

A new insulin delivery device has been developed and tested. It includes a reservoir, a pump, and a power pack. The reservoir holds 75 ml and is coupled to a precision peristaltic pump whose delivery can be set to any one of 128 different flow rates from 0 to 80 microliter/min (+/- 1.6% over 10 months) using the flow rate controller included in the battery power pack. The system weighs 525 g, consuming 50 mW at the maximum pumping rate, proportionately less at lower rates. Ten pumps have undergone bench tests for 30 days. One has been subjected to an extended life test of 16 months without change of tubing while seven complete systems have been used on dogs to demonstrate their capability for precise long-term (up to 16 months) intravenous insulin therapy. With this system, experimental diabetes has been controlled in 7 dogs for periods now extending beyond 16 months. This device now qualifies for-long term studies on hospitalized patients with diabetes mellitus.

Animals↗
PubMed1978

A portable precision pumping system for chronic, programmed insulin infusion.

This paper provides some details of a new insulin delivery system which includes a reservoir, a pump and a power pack. The reservoir holds 50 ml and is coupled to a precision peristaltic pump whose delivery can be set to any one of 128 different mean flow rates from 0 to 80 microliter/min (+/- 1.6% over 10 months) using the flow rate controller included in the battery power pack. The system weighs 525 g consuming 60 mW at the maximum pumping rate, proportionately less at lower rates. Ten pumps have undergone bench tests for 30 days. One has been subjected to an extended life test of 11 months while seven complete systems have been used on dogs to demonstrate their capability for precise longterm intravenous insulin therapy. With this system experimental diabetes has been reversed in 4 dogs for periods now extending beyond 6 months. This device now qualifies for long-term studies on hospitalized patients with diabetes mellitus.

Animals↗
PubMed1978

Continuous blood glucose analysis in vitro and in vivo.

A practical method for continuous blood glucose analysis in vivo is described. Using an interference-free enzyme reagent in a modified Auto-Analyzer whole blood glucose concentration can be monitored continuously and interpreted in terms of the actual plasma glucose concentration. The method uses a novel technique for preheating the sample diluent without introducing additional time delays, consumes whole blood at a rate of 0.05 ml/min, and demonstrates a transport delay of 148 s. Other improvements include an average baseline drift of -0.11 mg/dl/h and a mean change in sensitivity of -0.4% after 8.5 h. In vitro glucose recovery studies comparing whole blood to the corresponding plasma samples show the method is precise (101.3 +/- 0.7%), linearly proportional (slope of 1.007 +/- 0.012) and highly correlated (greater than 0.998) over the range of 0 to 500 mg/dl, with reference to a Beckman glucose analyzer. In vivo applications are presented to show that this method is suitable for us in systems such as the 'artificial endocrine pancreas'.

Autoanalysis↗
PubMed1978

Postbulbar duodenal ulcer occurring in a patient of diabetic coma.

Duodenal ulcer beyond the bulb occurred in a diabetic patient when he was in ketoacidotic coma causing serious anemia. Early investigation of the stomach and duodenum by endoscope was quite valuable for evaluating this bleeding complication and the healing process of the lesion was serially recorded. Since several cases of diabetic coma have been reported to die from gastrointestinal bleeding, this report presents the important aspect in the management of diabetic coma, and usefulness of emergency endoscope.

Adult↗
PubMed1976

A model for evaluation of the peroral insulin therapy: short-term treatment of alloxan diabetic rats with oral water-in-oil-in-water insulin emulsions.

Alloxan diabetic rats with fasting blood glucose levels above 300 mg/100 ml were treated with oral administration of water-in-oil-in-water (W/O/W) insulin emulsions at a dose of 50 U/100 g body weight, three times daily for 10 to 14 days. The course of diabetes was followed by determinations of glucose levels in blood and urine. During treatment with oral W/O/W insulin emulsions, daily excretion of urinary glucose decreased by about 30 to 40% (2 to 3 g/day) in all of the five rats studied, and returned to the pre-treatment levels after the treatment being discontinued. During treatment, a significant reduction in fasting blood glucose levels was observed in 4 out of 5 rats, giving the decrease by 18 to 44%. Quantitative estimates suggested that the effectiveness of 50 U/100 g of oral W/O/W insulin emulsions was comparable to that after intramuscular regular insulin at a dose of 0.5 U/100 g. Although oral W/O/W insulin emulsions are still of low efficiency, these results would indicate that diabetes can be controlled by effective oral insulin preparations.

Administration, Oral↗
PubMed1975

Dynamic study of exocrine function of the pancreas in diabetes mellitus with scintigraphy using 75Se-selenomethionine.

A dynamic study of scintigraphy of the pancreas using 75Se-selenomethionine in diabetic patients was performed. Patients were selected who complained of abdominal pain or diarrhea or both and whose pancreatic exocrine functions were thought to be disturbed. Selenium-75-selenomethionine (3 muCi/kg body weight) was injected intravenously and radioactivity (cpm) was recorded by a scinticamera for 10 min successively up to 120 min. After 20-30 min the increase of radioactivity in the selected area of the displayed pancreas usually reached a plateau. Pancreozymin (1 Harper unit/kg) and secretin (1 harper unit/kg) were administered intravenously and decrease of radioactivity in the same area was followed for 60 min to examine pancreatic exocrine function. After 75Se-selenomethionine injection, the angle of the initial increase of radioactivity, the height of the plateau, and the reactive decrease of radioactivity after pancreozymin and secretin were analyzed in each case. Radioactivity recorded on data tape was reproduced for each 10-min period on a cathode-ray tube display. Areas of interest were selected for dynamic analyses. To supplement the diagnosis by visual image of a scintigram of the pancreas, the scintigram was quantified in the present study and the dynamic curves of radioactivity in the selected area of the displayed pancreas were studied for a total of 3 hr. Application of the dynamic study of the pancreas scintigraphy and the additional data analyses seemed useful for the early detection of pancreatic exocrine dysfunction in diabetic patients in whom the ordinary laboratory pancreatic exocrine function tests gave uncertain results.

Adult↗
PubMedDate not supplied

Increased intestinal absorption of insulin in a micellar solution: water-in-oil-in-water insulin micelles.

Water-in-oil-in-water (W/O/W) insulin micelles were prepared, and the possibility of insulin absorption in a micellar form was examined. In this preparation, insulin was trapped in oil droplets of oleic acid in glyceryl-alpha-monooleate. (1) W/O/W insulin micelles were absorbed from the ligated jejunal loop of rabbits to the order of 12.3 to 58.5% of the dose given (10 mU/kg body weight) during the 3-h experimental period. (2) Alloxan diabetic rats were treated with intrajejunal administration of W/O/W insulin micelles at a dosage of either 25 or 50 mU/100 g body weight, three times daily for as long as 14 days. During treatment, a significant reduction in the daily excretion of urinary glucose was observed, concomitant with a decrease in fasting blood glucose. Quantitative estimates suggested that the effectiveness of 25 mU/100 g of intrajejunal W/O/W insulin micelles was comparable to that of regular insulin at a dosage of 1 mU/100 g i.m. These results would indicate that W/O/W insulin micelles, when given enterally, are more effective in lowering blood and urinary glucose levels than W/O/W insulin emulsions in which insulin was trapped in oil droplets of triglyceride.

Animals↗
PubMedDate not supplied

Validation of I.V. small-dose insulin infusion therapy in diabetic ketoacidosis of depancreatized dogs.

A validation of small-dose insulin infusion therapy was studied by the constant i.v. infusion of various doses of insulin into ketoacidotic depancreatized dogs. Constant insulin infusion of 5 x B, 10 X B, 30 X B and 50 X B (B = 225 microunit/kg/min) was performed for 3 h by mechanical pump. The following results were obtained: (1) plasma concentrations of immunoreactive insulin (IRI) increased proportionally to the dose of infused insulin, but the higher IRI did not result in a greater fall in plasma glucose concentration, correspondingly; the mean rate of fall in plasma glucose concentration of 5 x B was not significantly lower than that of 50 x B; beta-hydroxybutyrate and arterial pH improvements were observed in each group during the 3-h insulin infusion. These data suggested that for the improvement of diabetic ketoacidosis, the insulin infusion rate of more than 30 x B, which raised the plasma IRI levels above the physiological range, was not essential; (2) the necessity of potassium supplementation during the small-dose insulin infusion was suggested if the pre-treatment level of serum potassium was low. These results confirmed that in the absence of infection or severe acidosis small-dose insulin infusion therapy is as effective as the conventional large-dose insulin therapy.

Animals↗
PubMedDate not supplied

Effect of ageing on the relationship between early diastolic left ventricular function and mitral valve motion.

OBJECTIVE: The relationships between age and diastolic left ventricular function, and age and mitral valve motion were studied. DESIGN: The maximum velocity of circumferential fibre lengthening (negative peak Vcf) of left ventricular function and mitral valve motions, such as mitral valve E and A wave amplitude, D-E and E-F slopes, and their relationships were assessed. SUBJECTS: Twenty young, healthy persons (10 males and 10 females) from 20 to 47 years old (mean 34.5), and 26 older healthy subjects (five males and 21 females) from 62 to 94 years old (mean 80.0) were studied. INTERVENTION: M-mode echocardiography of left ventricular function and mitral valve motion were recorded and digitized for the assessment. MAIN RESULTS: Age showed a significant (P = 0.0001) correlation with negative peak Vcf (r = -0.62), with E wave amplitude (r = -0.83), with D-E slope (r = -0.71) and with E-F slope (r = -0.83). Negative peak Vcf was correlated with E wave amplitude (r = 0.51, P = 0.0007), with D-E slope (r = 0.31, P = 0.058), with E-F slope (r = 0.53, P = 0.0005). Its relations with mitral valve A wave amplitude was r = -0.30, P = 0.17 in the elderly group and r = 0.003, P = 0.99 in the younger group. A significant (P < 0.001) positive, linear correlation was observed between age and mitral A/E ratio (r = 0.82). CONCLUSIONS: The easily measurable mitral valve E-F slope and E wave amplitude can be used to assess early diastolic left ventricular function in ageing. Left atrial contraction appears to play a more important role in the elderly, compensating for the decline in early diastolic left ventricular function.

Adult↗