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Biomedical subjects

M Shichiri

Publications and source records attributed to M Shichiri.

At least 235 records · Page 13Linked to original sources
PubMed1985

Long-term application of wearable artificial endocrine pancreas--closed-loop intravenous vs subcutaneous insulin infusion.

For closed-loop glycemic control on IDDM, closed-loop sc insulin infusion algorithm has developed by analysing the pharmacokinetics of sc insulin absorption. With the algorithm, daily glycemic excursion in IDDMs was controlled to near-normal levels. These data suggested that the closed-loop sc insulin infusion algorithm might be feasible to regulate glycemia in diabetic patients for a long-term period by wearable artificial endocrine pancreas.

Algorithms↗
PubMed1985

Renal handling of urate in the syndrome of inappropriate secretion of antidiuretic hormone.

Three patients with the syndrome of inappropriate secretion of antidiuretic hormone had elevated uric acid clearances. Their uric acid clearances decreased markedly after the administration of pyrazinamide. Probenecid was given to two of them and it produced large increases in uric acid clearance. These data suggest that enhanced secretion in the renal tubules was responsible for the increased clearance of uric acid. This article provides evidence that hypouricemia in the syndrome of inappropriate secretion of antidiuretic hormone is due to increased tubular urate secretion.

Aged↗
PubMed1984

Primary biliary cirrhosis. A patient with adverse reactions to tiopronin and autoimmune hemolytic anemia with reticulocytopenia.

A 32-year-old woman with asymptomatic primary biliary cirrhosis had autoimmune hemolytic anemia associated with reticulocytopenia and thrombocytopenia despite an intensely erythroid bone marrow. Her anemia was successfully treated with oral prednisolone and intravenous pulse methylprednisolone, with a rapid response of reticulocytosis and sustained erythrocytosis. Tiopronin therapy was later initiated and resulted in fever, rash, exacerbation of the liver disease, and positive direct and indirect antiglobulin tests.

Amino Acids, Sulfur↗
PubMed1984

A mathematical insulin-secretion model and its validation in isolated rat pancreatic islets perifusion.

A mathematical insulin-secretion model was constructed by analyzing the glucose-induced insulin secretion using a control theory. To validate the model, experimental data obtained in the isolated rat pancreatic islet perifusion system were compared with the simulation results. The simulation study of the model was found to fit quite well to insulin responses under various experimental conditions. A glucose-induced insulin secretion from pancreatic islets' beta cell was found to be expressed as a function of proportional plus derivative response to glucose input with the first order time lag. And the negative rate of change in glucose concentration was found to suppress insulin secretion to the extent of the negative stimuli, regardless of glucose concentration. This model would be useful as a research tool for analysis of physiological significance of insulin secretory dynamics and clinical investigation of insulin secretion.

Animals↗
PubMed1984

Closed-loop glycemic control with a wearable artificial endocrine pancreas. Variations in daily insulin requirements to glycemic response.

We succeeded in miniaturizing a needle-type glucose monitoring system with characteristics suitable for application in a wearable, closed-loop control system. A wearable artificial endocrine pancreas (12 X 15 X 6 cm, 400 g) consisting of a sensor, a microcomputer system that calculates insulin and glucagon infusion rates, and two roller pumps was developed. Continuous glucose monitoring by a glucose sensor inserted in the subcutaneous tissue of the forearm or abdomen of healthy and diabetic volunteers revealed that glucose concentrations in subcutaneous tissue were 10% lower than, but were highly correlated with, blood glucose concentrations in the range of 49-388 mg/dl. Glycemic control was established in diabetic patients by intravenously infusing insulin in response to measured glucose concentrations on a moment-to-moment basis for a period of several days. By comparing the glycemic control obtained in each patient treated with multiple insulin injections or open-loop subcutaneous insulin infusion, the superiority of feedback control with the system was clearly demonstrated. During continuous glycemic regulation, day-to-day variations of insulin requirements were recognized in both basal insulin infusion and postprandial insulin infusion rates in response to identical meals and exercise. These data suggest the feasibility of long-term glycemic control in diabetic subjects with a wearable artificial endocrine pancreas, and indicate that to overcome changes in individual metabolic characteristics on a moment-to-moment basis, a closed-loop glycemic control system may be essential for ambulatory diabetic patients.

Adult↗
PubMed1984

The development of wearable-type artificial endocrine pancreas and its usefulness in glycaemic control of human diabetes mellitus.

We have succeeded in miniaturizing a glucose monitoring system into a needle-type which preserves the characteristics suitable for application in a wearable closed-loop control system. The wearable artificial endocrine pancreas (12 X 15 X 6 cm, 400 g) consists of the sensor, a microcomputer which calculates the insulin and glucagon infusion rates and of a 2-syringe driving system. The device succeeded in controlling glycaemia perfectly in depancreatized dogs for a period of 3 days, and with replacement of subcutaneously inserted sensor for up to 7 days. When glucose monitoring by a needle-type glucose sensor inserted into subcutaneous tissue of the forearm or abdomen of healthy and diabetic volunteers was attempted, the readings were about 10% lower than blood glucose concentrations, but good correlation between them was observed in the range of 60 to 400 mg/dl. Perfect glycaemic control was established by infusing insulin either intravenously or subcutaneously in response to measured glucose concentrations on a moment-to-moment basis in diabetics for a period of several days. These results might indicate the feasibility of long-term glycaemic control in ambulatory diabetic patients with a wearable closed-loop glycaemic control system.

Blood Glucose↗
PubMed1984

Long-term furosemide treatment in idiopathic edema.

Of 12 patients with idiopathic edema, ten patients had received total doses of furosemide of up to about 950 g. A good negative correlation was observed between the creatinine clearance and the duration of daily oral furosemide intake of more than 40 mg, and a highly significant correlation was found between the logarithm of the creatinine clearance and the duration of daily furosemide ingestion. Cessation of furosemide and institution of a sodium-restricted diet was followed by improvement in the creatinine clearance. Three patients had acute renal failure with myoglobinuria. All patients examined showed tubular and/or interstitial changes. This study shows that in idiopathic edema, long-term furosemide treatment gradually impairs renal function, with reversal to a considerable degree after cessation of the drug, and that it causes organic changes in the kidney.

Adolescent↗
PubMed1983

Glycaemic control in pancreatectomized dogs with a wearable artificial endocrine pancreas.

A needle-type glucose sensor has been developed using a platinum electrode covered with immobilized glucose oxidase. Experiments with albumin-saline solution in vitro showed that at 5.5 mmol/l glucose concentration the output current generated was 1.2 +/- 0.4 nA (mean +/- SD). The current increased as a linear function of glucose concentration over the range (0-27.7 mmol/l). The response time to reach 90% of the final plateau value was 16.2 +/- 6.2s. The signal-to-noise ratio of the sensor was 15.8 +/- 2.6 decibels. The temperature coefficient in output was 2.3 +/- 1.0%/degrees C. The current output was not affected significantly by changes in oxygen tension of the solution in the range 25-150 mmHg. In vivo, the output current of sensors inserted into the subcutaneous tissues of dogs was directly related to blood glucose concentrations after oral glucose or meals. Daily checking of the sensors maintained in subcutaneous tissues in five dogs showed that the sensitivity decreased gradually to 87.2 +/- 7.6% at 72 h, and dropped significantly to 57.4 +/- 7.0% of the initial output by 96 h. A wearable artificial endocrine pancreas (18.0 x 17.7 x 7.9 cm, 700 g) was developed, consisting of a needle-type glucose sensor, a microcomputer system and a pump driving mechanism. Three pancreatectomized dogs were fitted with the system by inserting the sensor into subcutaneous tissue. By renewing the sensor every fourth day, the device could maintain the daily glucose variations in diabetic dogs within the range 5-9.5 mmol/l for 7 days.

Animals↗
PubMed1983

Increased urinary kallikrein-like activity in the syndrome of inappropriate secretion of antidiuretic hormone.

The role of the kallikrein system in the natriuresis of SIADH was studied in 3 patients. Following free water intake, serum Na decreased. Urinary Na excretion, urinary aldosterone excretion and urinary kallikrein-like activity (UKaV) increased. Significant relationships were observed between UKaV and urinary aldosterone excretion during the study. Further, there were significant relationships between serum Na and UKaV, and between uric acid clearance and UKaV. In 1 patient, who was observed for a longer period, a significant relationship was observed between Na clearance and UKaV. We conclude that UKaV is increased during hyponatremia in SIADH by volume expansion. This increase in UKaV may play a role in the natriuresis in SIADH.

Aged↗
PubMed1983

Evidence of beneficial effects of strict glycemic control on diabetic vascular complications--a prospective study with artificial devices.

This prospective study was undertaken to examine whether glycemic normalization could have beneficial on the course of diabetic vascular complications in 6 insulin-dependent diabetics. A significant amelioration of glycemic regulation was achieved by intensive glycemic control with artificial devices and multiple injections for 3 months, which also resulted in an improvement in conduction velocity, a regression in retinovascular permeability and a decrease in urinary total protein excretion. These results indicate that even after short-term treatment, glycemic near-normalization can have a beneficial effect on the early stage of diabetic vascular complications.

Blood Glucose↗
PubMed1982

Wearable artificial endocrine pancrease with needle-type glucose sensor.

Miniaturisation of the bedside artificial endocrine pancreas in necessary to provide a means of restoring physiological glycaemic excursions in diabetic patients in the long term. One of the remaining problems in producing such a sophisticated device is the difficulty in developing a sufficiently small glucose-monitoring system. A needle-type glucose sensor has been developed which is suitable for use in a closed-loop glycaemic control system. The wearable artificial endocrine pancreas, incorporating the needle-type glucose sensor, a computer calculating infusion rates of insulin, glucagon, or both, and infusion pumps, was tested in pancreatectomised dogs: the device produced perfect control of blood glucose for up to 7 days.

Animals↗