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Biomedical subjects

D A Lang

Publications and source records attributed to D A Lang.

61 records · Page 4Linked to original sources
PubMed1981

Brief, irregular oscillations of basal plasma insulin and glucose concentrations in diabetic man.

The basal plasma insulin and glucose concentrations of 12 diet-treated maturity-onset diabetics were measured at minute intervals for 2 h. Brief, irregular oscillations (mean period 8.8 min) in plasma insulin were superimposed on longer term fluctuations (greater than 30 min). Time series analysis demonstrated a synchronous plasma glucose oscillation (mean amplitude 0.03 mmol/L) associated with short insulin cycles. The glucose changes seen in diabetic subjects were similar to the short plasma insulin cycles (less than 10 min) observed in normal subjects. In contrast, the longer plasma insulin cycles (greater than 10 min) of normal subjects were associated with a plasma glucose oscillation that rose before the end of the cycle. The demonstration of insulin oscillations independent of preceding plasma glucose changes in both normal and diabetic subjects suggests a pancreatic oscillating mechanism of "pacemaker". The associated glucose changes may reflect the entrainment, by the insulin cycles, of glucose production or utilization.

Blood Glucose↗
PubMed1981

Softening the 'perverse' effects of quality assurance.

Interdisciplinary stress is a common, though unwelcome, by-product of quality assurance activities. The divergent lines of authority in a hospital are usually inadequate for dealing with interdisciplinary problems or with joint or contested matters, resulting in uneven treatment of those identified as having lapsed from accepted standards. If the purpose of quality assurance--improvement of patient care--is not to be perverted, current methods of dealing with identified problems must be revised.

Conflict, Psychological↗
PubMed1979

Cyclic oscillations of basal plasma glucose and insulin concentrations in human beings.

In a study of whether oscillations in plasma glucose and insulin occur in human beings, plasma samples were taken at one-minute intervals from 10 normal subjects for periods lasting between one and two hours. In five subjects the basal plasma insulin concentrations cycled regularly, with a mean period of 13 minutes and mean amplitude of 1.6 mU per liter (11.5 pmol per liter). A concurrent plasma glucose cycle was demonstrated, with a mean amplitude (after averaging to minimize random error) of 0.05 mmol per liter (1 mg per decliter). The average plasma glucose cycle was two minutes in advance of the plasma insulin. In the subjects with less regular plasma insulin cycles, a similar plasma glucose rise was demonstrated two minutes before the insulin rise. These phase relations are compatible with the presence of a negative-feedback loop between the liver and pancreatic beta cells that regulates both basal plasma insulin and glucose concentrations, although the cyclic beta-cell secretion could be independent of plasma glucose.

Adult↗
PubMedDate not supplied

Comparison of chlorpropamide and glibenclamide treatment of maturity-onset diabetes: control assessed by fasting plasma glucose concentrations.

Twelve maturity-onset diabetic subjects were treated with chlorpropamide once daily, glibenclamide once daily, or glibenclamide twice daily in a crossover design study. Doses were increased until the fasting blood glucose concentrations became less than 6 mmol/L (108 mg/dl), at which time the patients were admitted for a 24-h study period. There was little difference between the plasma glucose and insulin responses to chlorpropamide or glibenclamide given twice daily (mean doses 489 and 11 mg/day, respectively). When glibenclamide was given once daily (mean dose 9 mg/day), similar plasma glucose concentrations during the day were obtained with slightly higher plasma glucose concentrations during the night. Four patients had chlorpropamide-induced flushing with alcohol, and six patients had postprandial hypoglycemia on glibenclamide. Chlorpropamide once daily or glibenclamide twice daily are suitable for control based on fasting blood glucose measurements.

Adult↗