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Biomedical subjects

P A Svendsen

Publications and source records attributed to P A Svendsen.

11 recordsLinked to original sources
PubMed1979

Insulin treatment and state of control before, during, and after connection to a glucose controlled insulin infusion system (Biostator).

Nine insulin-dependent, juvenile-onset diabetics were treated for more than twenty four hours with an artificial beta cell (Biostator). Using the amounts and profile of the insulin delivered by the machine as a guide for subsequent subcutaneous therapy, a better state of control was obtained. However, with the algorithm constants used, we found the Biostator to deliver more insulin (average 36%) than needed for subcutaneous therapy. Repeated oral glucose tolerance tests show that constants used in the algorithms might be optimized.

Adolescent↗
PubMed1979

Closed-loop system in evaluation of insulin infusion rates for an open-loop system.

The daily insulin requirements as calculated with a closed-loop system (Biostator), were used for insulin infusion with a portable, miniaturized pump in 6 juvenile-onset, insulin-requiring diabetics. Three diabetics were given insulin in a manner like that of the Biostator, e.g., maximal insulin infusion about 1 hour after start of meals. The MBG was 8.7 +/- 3.9 (SD) mmol/l. Three other diabetics had insulin in a fixed profile with peaks beginning simultaneously with meals. MBG of these patients was 4.4 +/- 1.9 mmol/l. Knowing the daily insulin dosage as calculated from the Biostator, normal blood glucose levels can be achieved with a fixed profile of insulin given by a portable pump.

Adult↗
PubMed1978

Long-term treatment of acromegaly with bromocriptine.

Treatment with bromocriptine, 30-55 mg daily, in 13 acromegalics for 1-15 months, resulted in a 60% decrease in growth hormone secretion, as judged from the excretion of growth hormone in 24-h urine. Normal excretion was obtained in 10 patients, while 1 patient showed no response. The plasma growth hormone response to O-GTT was improved, but not normalized, in 4 of 7 patients treated for more than 6 months, and marked glucosuria disappeared in two diabetics. While the secretion of TSH, LH and FSH was unchanged, the prolactin secretion was inhibited. The urine excretion of free cortisol showed a 30% decrease, possibly due to a direct effect of bromocriptine on the ACTH-secretion. Hypercalcaemia was never seen, but the initial hypercalcuria showed a modest decrease without measurable changes in the creatinine clearance. The subjective relief during long-term treatment was marked in 10 of 11 patients and the dominating symptoms disappeared in 40-67%, whereas heal-pad thickness, enlarged sellae, and visual fields remained unchanged. No serious side effects were observed. Treatment with bromocriptine seems effective and should be considered as a remedy amongst others, in suitable cases of acromegaly.

Acromegaly↗
PubMed1978

Kidney function in normal man during short-term growth hormone infusion.

Kidney function was studied in 9 normal males before and during a 2 h growth hormone (GH) infusion of 50 ng/kg/min. The following variables were measured during each 20 min clearance period: glomerular filtration rate, GFR, effective renal plasma flow, RPF (steady state infusion technique with urinary collections using [125I]iothalamate and [131I]iodohippurate), and urinary albumin and beta2-microglobulin excretion rates (radioimmunoassays). The GH infusion resulted in a 10-fold increase in plasma GH concentration. All the above mentioned variables remained practically unchanged during the infusion except for a small (-5%) but significant decrease in renal plasma flow (P less than 0.01). Our negative results contrast to the findings of increased GFR and RPF during prolonged GH administration and suggest that GH requires several hours or days for its renal effects to become manifest.

Adult↗
PubMed1977

The effect of short-term glucagon infusion on kidney function in normal man.

Kidney function was studied in six normal males before and during a 2 h glucagon (10 ng/kg/min) infusion. The following variables were determined during each 20 min clearance period; glomerular filtration rate (GFR), renal plasma-flow (RPF) , filtration fraction (FF), urinary albumin and beta2-microglobulin-excretion rates. Glucagon infusion resulted in a fourfold increase in plasma glucagon concentration. The infusion induced a significant increase in GFR (+9%), FF (+9%) and urinary beta2-microglobulin excretion rate (+32%), (p less than 0.01). RPF and urinary albumin excretion rates were not significantly changed. We suggest that glucagon may contribute to the reversible kidney function alterations typically found in poorly regulated juvenile diabetes, a state with relative or absolute hyperglucagonaemia.

Adult↗
PubMed1976

The effect of metabolic regulation on microvascular permeability to small and large molecules in short-term juvenile diabetics.

The microvascular permeability to small and large molecules was studied during good and poor metabolic regulation in ten short duration juvenile diabetics. The following variables were measured; daily urinary albumin and beta2-microglobulin-excretion rates, whole body transcapillary escape rate of albumin (TER), glomerular filtration rate (GFR), capillary filtration coefficient (CFC), and capillary diffusion capacity (CDC). The urinary albumin and beta2-microglobulin concentration were measured by sensitive radioimmunoassays; TER was detemined from the initial disappearance of intravenously injected 125I-labelled human serum albumin; GFR was measured on the forearm by straingauge plethysmography and CDS for 51Cr-EDTA clearance; CFC was measured on the forearm by straingauge plethysmography and CDC, for 51Cr-EDTA was determined in the jyperaemic anterio tibial muscle by the local clearance technique. All the above mentioned variables, except CDC, were significantly increased during poor metabolic regulation, indicating a functional microangiopathy. The mechanisms of these alterations appear to be increased filtration pressure in the microcirculation and/or increased porosity of the microvasculature. The findings of increased microvascular albumin passage are compatible with the hypothesis that the organic - histologicallly demonstrated - diabetic microangiopathy is a long-term effect of periods of increased extravasation of plasma proteins, with subsequent protein deposition in the microvascular wall, i.e. the concept to plasmatic vasculosis.

Adolescent↗