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Biomedical subjects

R Puukka

Publications and source records attributed to R Puukka.

At least 37 records · Page 2Linked to original sources
PubMed1983

Pancreatic islet cell function and metabolic control in an infant with permanent neonatal diabetes.

A girl with typical clinical manifestations of neonatal diabetes was observed for 16 months with consecutive evaluations of pancreatic beta- and alpha-cell function and metabolic control. At the diagnosis both the plasma immunoreactive insulin (IRI) and C-peptide concentrations were inappropriate for the contemporaneous hyperglycemia. During the follow-up, the C-peptide fell twice below the detection limit but the beta-cell function recovered partially on both occasions. Based on 24-hour urinary C-peptide excretion, the endogenous insulin secretion was less than 10% of that in non-diabetic infants. When diagnosed the patient had plasma immunoreactive glucagon (IRG) and glucagon-like immunoreactivity (GLI) concentrations below the reference range for normal neonates. The IRG normalised within the first month, while the GLI increased to a level exceeding the reference range. Hemoglobin A1 had already risen at the time of diagnosis and subsequently rose to a level indicating poor metabolic control. The findings indicate an immature function of both beta- and alpha-cells at the diagnosis with the alpha-cells maturing within the first month. The recovery of the beta-cell function, after two failures in this patient with permanent neonatal diabetes, suggests that the beta-cell damage was at least partially reversible.

Diabetes Mellitus, Type 1↗
PubMed1983

Erythrocyte insulin binding in normal infants, children and adults.

To establish normal insulin binding criteria, we studied the binding of insulin to erythrocytes from normal subjects of different ages. Insulin binding to cord erythrocytes and to erythrocytes from infants aged 2-7 days was significantly higher at tracer and physiological insulin concentrations than was binding to cells from children aged 1-15 years and adults. In infants aged 1-12 months the maximum insulin binding to erythrocytes was significantly higher than that to erythrocytes from children, and in addition, it correlated negatively with age. An increase in receptor concentration was found in cord erythrocytes whereas an increased receptor affinity for insulin was found in erythrocytes from infants. Insulin binding characteristics in erythrocytes from prepubertal and pubertal children were basically similar to those in women. Erythrocytes from men bound significantly higher amounts of insulin than did those from women. This difference was associated with changes in receptor affinity for insulin. There was no correlation between the insulin binding characteristics and the circulating concentration of insulin or C-peptide. The increased erythrocyte insulin binding at birth persisted over the neonatal period. There was an overall negative correlation between the maximum insulin binding and age in the subjects studied, but the major decrease in erythrocytes insulin binding occurred during the first year of life past the neonatal period. These observations stress the importance of using age-matched controls in studies on erythrocyte insulin binding in disease states.

Adolescent↗
PubMed1983

Basal insulin secretion and erythrocyte insulin binding in preterm and term newborn infants.

To study the ontogeny of the insulin secretion and the erythrocyte insulin receptor we measured plasma immunoreactive insulin and C-peptide concentrations and the binding of [125I]-insulin to the erythrocytes in cord blood from 16 preterm and 16 term infants. 20 normal-weight adults were also studied. The C-peptide concentrations and the molar ratio of C-peptide to insulin were lower in the newborn infants than in the adults. The immunoreactive insulin correlated positively with birth weight in the term infants. The insulin binding to erythrocytes from the newborn infants was increased when compared to the adults. Erythrocytes from the preterm infants bound more insulin than the cells from the term infants. There was a strong negative correlation between insulin binding and gestational age. In the term infants, plasma C-peptide correlated negatively with the insulin binding. The increased binding to erythrocytes from the term infants was due to an increase in the receptor concentration. The high insulin binding in the preterm infants was a result of both an increased receptor concentration and affinity. These data suggest that the basal insulin secretion is similar in preterm and term infants and that the clearance of insulin is decreased in newborn infants. The increased insulin binding in newborn infants may be a mechanism by which the growth stimulatory effect of insulin in fetal life is mediated.

Adult↗
PubMed1982

Erythrocyte adenosine deaminase, purine nucleoside phosphorylase and phosphoribosyltransferase activity in patients with Down's syndrome.

The erythrocyte adenosine deaminase, nucleoside phosphorylase, hypoxanthineguanine phosphoribosyltransferase and adenine phosphoribosyltransferase activities and plasma urate concentrations were measured in 20 cases of Down's syndrome and in 20 age- and sex-matched control subjects. The mean erythrocyte adenosine deaminase and adenine phosphoribosyltransferase activities and plasma urate concentrations were significantly higher in Down's syndrome subjects than in controls (p less than 0.001, p less than 0.01 and p less than 0.001, respectively). In all subjects studied there was a positive correlation between the erythrocyte adenosine deaminase activity and plasma urate concentration (r = 0.488, p less than 0.005). The concentrations of the erythrocyte adenine nucleotides, AMP, ADP and ATP, did not differ in Down's syndrome (n = 10) from those of control subjects (n = 10). The results suggest that the increase of plasma urate concentrations is a consequence of the increase in adenosine deaminase activity in Down's syndrome patients.

Adenine Nucleotides↗
PubMed1982

Haemoglobin Hijiyama: a haemoglobin variant found in connection with glycosylated haemoglobin estimation in a Finnish diabetic boy.

A variant of haemoglobin A, named earlier haemoglobin Hijiyama, was found in three generations of a Finnish family in connection with the determination of glycosylated haemoglobin of a diabetic patient. The biochemical abnormality is in the beta-chain at residue 120 where lysine is replaced by glutamic acid. In the heterozygote carriers of the abnormal haemoglobin there was no apparent association with clinical or haematological abnormalities. By isoelectric focusing in thin-layer polyacrylamide gels, haemoglobin Hijiyama could be distinguished with high specificity from haemoglobin A as well as from other haemoglobin variants earlier found in Finland. The glycosylated haemoglobin fractions (haemoglobin A1 and haemoglobin Hijiyama 1) in the diabetic patient sample could be determined by colorimetric and electrophoretic methods.

Child↗
PubMed1982

Electrophoretically determined haemoglobin A1 concentrations during short-term changes in glucose concentration.

In our experience, electrophoresis on agar gel is a very satisfactory alternative to the more widely used chromatographic methods for the determination of haemoglobin A1 (HbA1). Like the chromatographic method, the electrophoretic method is unable to detect any difference between the labile intermediate form of HbA1, which changes rapidly with acute changes in blood glucose level, and the more stable end-product, which reflects long-term glucose levels. In vitro at 37 degrees C the electrophoretically determined HbA1 concentration increases with increasing glucose concentration and with time in both normal and diabetic erythrocytes, but decreases to the preincubation concentration during further incubation of the erythrocytes in a glucose-free medium at 37 degrees C. Similarly, if normal or diabetic erythrocytes are incubated with isotonic saline before the HbA1 assay, the labile fraction is eliminated. In diabetics, the decrease in HbA1 concentration correlates with both the blood glucose level and the preincubation HbA1 concentration. Thus for HbA1 to be an accurate indicator of long-term glucose control in diabetic patients saline incubation of the erythrocytes may be necessary before HbA1 assay by the electrophoretic method, otherwise the assay results will also reflect recent changes in the blood glucose level.

Adolescent↗
PubMed1982

99mTc-DTPA--a useful clinical tool for the measurement of glomerular filtration rate.

The single injection 99mTc-DTPA clearance was compared with the inulin clearance performed with the constant infusion technique in 22 subjects. There was a good correlation between these two methods (r = 0.968, p less than 0.001). Although the single injection technique calculated by one compartment model is not accurate enough for research purposes, it seems to work well in routine clinical practice for the measurement of glomerular filtration rate using 99mTc-DTPA as a tracer substance. The performance is simple, it needs only a few blood samples, nor does it need any urine collection, the radiation dose is low and it seems to be more accurate than the endogenous creatinine clearance.

Adolescent↗
PubMed1981

Exercise-induced proteinuria in children and adolescents with type 1 (insulin dependent) diabetes.

The urinary excretion excretion of albumin and Beta2-microglobulin was measured by radioimmunoassay in 64 children and adolescents with Type 1 (insulin dependent) diabetes and in 68 non-diabetic subjects aged from 9 to 19 years. At rest the albumin excretion of te diabetic subjects did not differ from that of te non-diabetic children and adolescents but during exercise the albumin excretion was significantly higher in children and adolescents with Type 1 diabetes (p less than 0.02). the excretion rate of Beta2-microglobulin in diabetic subjects did not differ from that of the healthy subjects. Both at rest and during exercise the albumin excretion rate was highest in those diabetics with poorest metabolic control of their disease.

Adolescent↗
PubMed1981

Elevated erythrocyte adenosine deaminase activity in Down's syndrome.

Erythrocyte ADA activity was measured in 29 cases of Down's syndrome and in 29 age- and sex-matched controls subjects. The mean activity (+/- S.D.) of ADA in Down's syndrome was 1883 +/- 463 mU/g Hb (37 degrees C) and 1361 +/- 294 mU/g Hb in the controls. The difference was statistically significant (p less than 0.001). The purine metabolism of Down's syndrome patients is discussed.

Adenosine Deaminase↗
PubMed1980

A rapid and simple gas-liquid chromatographic determination of valproic acid (alpha-propyl-valeric acid) in serum.

A simple and rapid gas-liquid chromatographic method for the determination of valproic acid in serum is described. Valproic acid is extracted from acidified serum into chloroform and analyzed by gas-liquid chromatography using an FFAP column. The sensitivity of the method is 5 mumol/l and the within-run and day-to-day precisions (CV) are 4.5% or better. Analytical recovery is estimated to exceed 98% and no interference from other drugs or constituents of serum has been observed. The method was used to study the half-life of valproic acid in five healthy persons receiving a single oral dose of the drug, and the technique is well adapted to the routine monitoring of epileptic patients. In routine analysis, the determination of 50 serum samples may be performed by one technician during a normal working day.

Epilepsy↗
PubMed1979

Gray scale ultrasound signs of gallbladder stones: clinical and experimental study.

200 patients with radiologically detected gallbladder stones were examined with gray scale ultrasound. Nine different ultrasound signs caused by the stones were found. A physical and chemical analysis of the gallstones of 33 patients from different image groups was performed. Viscosity of the bile and the thickness of the gallbladder wall were measured. Phantom experiments were performed and four different ultrasound signs were found but there was no significant correlation between these and the physicochemical properties of the gallstones.

Bile↗
PubMed1978

Comparison of alkaline phosphatase isoenzymes determined by an inhibition method and by electrophoresis.

A chemical inhibition procedure suitable for the routine determination of alkaline phosphatase (AP) isoenzymes in serum has been adapted for use with a fast kinetic analyzer, System Olli 3000. The results of this procedure are compared with the electrophoretic separation of alkaline phosphatase isoenzymes. The comparison of the results obtained indicates that the AP-urea/AP ratio can be used to differentiate between patients with bone and liver disease and that it is possible to estimate the relative bone and liver isoenzyme activities from this ratio quickly using two simple equations.

Adult↗
PubMed1978

An automated method for determination of serum and urine alpha-amylase.

An automated method for the determination of alpha-amylase activities of serum and urine using the Phadebas Amylase Test is described. The procedure has been adapted for the System Olli 3000 analyser using amylase tablets whose weight is half of that of normal tablets. The results are calculated by the computer with the aid of a standard curve calculated theoretically. This automated procedure is fast, as many as 120 analyses per hour can be carried out. Intra-assay precision of 2.0 and 2.2% (CV) is obtained from serum samples containing 301 and 181 u/l of alpha-amylase, respectively (n = 20), and inter-assay precision is 4.4 and 3.3% with mean values of 337 and 196 u/l, respectively (n = 20). When the automated procedure is compared with the manual procedure on 85 sera with alpha-amylase activities below 1000 u/l, a good correlation r = 0.992, and a regression equation y = 1.01x-6 are found. In the case of serum and urine samples, which contain high enzyme activities, the automated method gives slightly higher results than the manual method.

Amylases↗
PubMed1978

Enzymatic determination of triglycerides with a system Olli 3000 analyser.

We describe a totally enzymatic method for determining serum triglycerides adapted for a System Olli 3000 analyser. In this procedure triglycerides are determined by measuring free glycerol enzymatically after hydrolysis of a sample with lipase and esterase. The method utilizes two standards for calibration, includes a blank correction and requires 20 microliter of serum. Forty serum samples can be analysed in about 30 min. The procedure is linear up to a concentration of 8 mmol/l of triglycerides. The precision and sensitivity of the method are good. A comparison of this method with another enzymatic method gave the correlation coefficient 0.988 and the regression line y = 1.02x + 0.02 (n = 95).

Autoanalysis↗
PubMed1978

Maternal and foetal plasma bupivacaine concentrations in labour with segmental epidural analgesia.

Maternal and foetal plasma bupivacaine concentrations were assayed following segmental epidural analgesia during the first stage of 14 normal labours. Analgesia was accomplished with 20 mg of 0.5% bupivacaine. 10 mothers received only one dose and four mothers two doses. The maternal and foetal plasma bupivacaine levels remained very low and the foetomaternal ratios were about 1:4 during the labour. At delivery, the foeto-maternal ratio increased, showing that the decline of bupivacaine concentrations is slower in foetal than in maternal plasma.

Adult↗