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Biomedical subjects

T Koivula

Publications and source records attributed to T Koivula.

At least 163 records · Page 9Linked to original sources
PubMed1986

Long-term anticonvulsant therapy and vitamin D metabolism in ambulatory pubertal children.

Parameters of calcium metabolism were thoroughly examined in 28 adolescents with long-term (over 6 years) anticonvulsant therapy (phenytoin, carbamazepine or combination) and in 10 normal controls in September and in March. The adolescents did not receive any vitamin D supplementation during the study. Serum calcium, inorganic phosphorus, parathyroid hormone and alkaline phosphatase levels in the anticonvulsant group did not differ from those of the control group. Serum 25(OH)D and 24,25(OH)2D levels were in all groups consistently higher in September than in March, but no seasonal variation was found in the 1,25(OH)2D levels in any group. The serum 25(OH)D levels in the phenytoin group in March were the lowest among the three groups treated with anticonvulsants, but the levels in the anticonvulsant groups did not differ significantly from each other or from the control group in the same season. The 24,25(OH)2D and 1,25(OH)2D levels in the anticonvulsant groups did not differ significantly from those of control group in September or in March. There was no correlation between anticonvulsant serum free fraction levels and vitamin D metabolites. The bone mineral content in the distal radius was not significantly decreased in the epileptic patients. In conclusion, the long-term anticonvulsant therapy did not induce the so-called "anticonvulsant rickets" in this ambulatory adolescent material. Our data do not indicate that anticonvulsant drugs alter significantly the vitamin D metabolism. Thus, routine vitamin D supplementation does not appear to be indicated in children on anticonvulsant therapy.

Adolescent↗
PubMed1986

Maternal compared with infant vitamin D supplementation.

Vitamin D metabolites were studied in mother-infant pairs at delivery and eight and 15 weeks after that to evaluate the possibility of vitamin D supplementation of infant through the mother. Healthy mothers (n = 49) delivering in January received daily either 2000 IU (group 1), 1000 IU (group 2), or no (group 3) vitamin D. Their infants were exclusively breast fed, and those in group 3 received 400 IU of vitamin D a day. After eight weeks of lactation the infantile vitamin D concentrations were similar in groups 1 and 3 but significantly lower in group 2. The serum 24,25-dihydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations were also lower in group 2. The mean mineral, parathyroid hormone, and alkaline phosphatase values showed no intergroup differences at any point. No infants showed any clinical or biochemical signs of rickets, and their growth was equal. In conclusion, a daily postpartum maternal supplementation with 2000 IU of vitamin D, but not with 1000 IU, seems to normalise the vitamin D metabolites of breast fed infants in winter. Maternal safety with such supplementation over prolonged periods, however, should be examined.

Breast Feeding↗
PubMed1986

Metabolic control in adolescent insulin-dependent diabetics referred from pediatric to adult clinic.

The metabolic control of 61 consecutive cases of adolescent diabetes was followed 1 year before and 1 year after the patients were referred from a pediatric to adult clinic. The level of control of the disease was determined by measurements of haemoglobin A1 made on visits to the out-patient clinic. No significant deterioration of the disease was noted on the first visit to the adult clinic. Boys and patients with a shorter disease history coped better with the transition period. During the first year of treatment at the adult clinic the metabolic control of the disease improved significantly (p less than 0.001). Girls and diabetics with a long disease history should be well-prepared for referral to adult clinics.

Adolescent↗
PubMed1986

Evaluation of a new inhibitor test for isoamylase on Hitachi 705 analyser.

We describe a simple and rapid method for measuring pancreatic and salivary type amylases using the Hitachi 705 analyser. The determination is based on the inhibition of salivary amylase using an inhibitor isolated from wheat germ. The precision of the proposed method was very good: within-day precision varied from 0.4 to 2.5% (CV) and day-to-day precision from 2.2 to 3.7% (CV). The new application correlated well with another commercially available inhibition method. As the standardization is very stable and the assay procedure exactly the same as for the total amylase assay, the proposed method is suitable for routine isoamylase determination. Reference values for pancreatic and salivary amylase activities are presented.

Autoanalysis↗
PubMed1985

Tumour-associated antigen CA 125 in patients with ovarian cancer.

The serum levels of antigen CA 125 expressed by epithelial ovarian carcinoma were measured in 27 postmenopausal women with ovarian tumours and in 16 controls. Increased serum levels of CA 125 were found in nine (75%) out of 12 patients with ovarian cancer; in three with stage I disease levels were not elevated. No significant difference was found in the concentration of CA 125 detected in peripheral or ovarian venous blood. Decreased antigen levels were found 6-30 weeks after radical operation and cytostatic chemotherapy in the ovarian cancer group. The results indicate the value of measuring CA 125 as a tumour marker in the follow-up of ovarian cancer.

Adenocarcinoma↗
PubMed1985

Elevated progesterone levels in serum and ovarian venous blood in patients with ovarian tumors.

Peripheral serum concentrations of progesterone were measured in 27 postmenopausal women with malignant, borderline, or benign ovarian tumor and in 10 women without ovarian neoplasm. The progesterone levels were significantly higher in all ovarian tumor groups as compared with the controls. There was no difference between malignant and benign tumors. Patients with a tumor volume over 1 000 ml had higher progesterone levels than patients with smaller tumors, in both peripheral and ovarian venous blood. Mucinous ovarian tumors were associated with the highest progesterone levels, compared with other histologic types of ovarian tumor. The results indicate that mucinous ovarian tumors are able to secrete progesterone and that the stage of malignancy has no effect on this hormonal activity.

Adenocarcinoma↗
PubMed1985

Maternal blood haemostatic-fibrinolytic balance and intrauterine growth retardation.

In order to study the association between haemostatic-fibrinolytic balance during late pregnancy and retarded foetal growth, 22 mothers with suspected intrauterine growth retardation were studied by blood haematocrit and platelet count, plasma fibrinogen and serum fibrinogen degenerating products (FDP) in late pregnancy. Fifteen mothers with undisturbed foetal growth served as controls. No statistical differences could be found between these two groups of mothers in any of the studied blood parameters. It is thus concluded that a defect in the haemostatic-fibrinolytic balance seems not to play any very important role in the etiology of intrauterine growth retardation.

Adult↗
PubMed1985

Evaluation of the value of fluorometric serum heat stable alkaline phosphatase assay in patients operated on for ovarian tumors.

The usefulness of a simple fluorometric assay for serum heat-stable alkaline phosphatase (HSAP) in the diagnosis and follow-up of ovarian cancer patients was evaluated. 50 percent of the patients with malignant ovarian tumors had serum HSAP-activities above the upper reference range. Active production of this tumor marker in malignant but not in benign ovarian tumors was demonstrated by analysing serum HSAP-activities in ovarian vein blood. After operation, serum HSAP-activities decreased in all cancer patients with elevated preoperative values. Our results suggest that fluorometric serum HSAP-assay may be a useful alternative method for the determination of this tumor marker especially in a clinical laboratory.

Alkaline Phosphatase↗
PubMed1984

Effect of surgical stress on the erythrocyte insulin receptor.

The aim of this study was to investigate whether surgical trauma causes changes in insulin receptors which may have significance on the causation of post-traumatic insulin resistance. Twenty-four patients scheduled for lumbar intervertebral disc operations or thoracotomy were investigated. In patients who did not receive glucose during operation blood glucose and plasma insulin concentrations did not change but lipolysis was induced as indicated by the increase of serum free fatty acids concentration. Glucose infusion (5% w/v) caused a hyperglycaemic and hyperinsulaenemic response without lipolysis. In patients not receiving a glucose load the number of insulin receptors on erythrocyte measured 4 h postoperatively increased from the preoperative values and the affinity of the receptors to insulin in physiological concentration range increased. In patients with glucose load the number of receptors decreased and receptor affinity to insulin at physiological concentration decreased. The results suggest that in patients receiving a glucose load the receptor changes indicate the perioperative development of insulin resistance at receptor level.

Journal Article↗
PubMed1984

Serum amylase and isoamylase assay on the Hitachi 705 automatic clinical chemical analyzer.

The automated continuous alpha-amylase assay using p-nitrophenyl-alpha-D-maltoheptaoside (Boehringer Mannheim) as substrate on the Hitachi 705 clinical chemical analyzer, was compared with the Phadebas Kinetic Amylase Assay (Pharmacia Diagnostics) on the Hitachi 705. The two methods showed good correlation. The precision varied from 1.0 to 2.5% (CV) within-day and from 1.1 to 5.6% (CV) day-to-day. The substrate, p-nitrophenyl-alpha-D-maltoheptaoside, was also applied to an automated isoamylase assay. The amylase inhibitor from wheat was used to determine the ratio of pancreatic and salivary amylase activities of serum. About 80% of salivary type amylase was inhibited up to an activity level of 1000 U/l, while inhibition of pancreatic type amylase activity was only 10-15%. Ratios of pancreatic to salivary amylase from 0.1 to 10 can be evaluated in serum with wheat inhibitor. The precision of the isoamylase determination by the Boehringer amylase method was acceptable.

Amylases↗
PubMed1984

Binding of tyrosine-A-14(125I)-monoiodoinsulin to human erythrocytes.

We have studied the method for the determination of human erythrocyte insulin receptor concentrations using tyrosine-A-14-monoiodoinsulin as the labelled ligand with increasing amounts of unlabelled insulin in a saturation assay. An overnight incubation at 0-+4 degrees C was found to give the highest receptor concentrations and highest affinities for the ligand. Insulin receptor concentrations were found to be very low and lower in erythrocytes from normal females than from normal male subjects (7.0 +/- 1.9 and 10.5 +/- 1.6 receptors per erythrocyte, respectively). Our results suggest that an initially homogenous class of insulin binding sites upon exposure to insulin can appear in different forms with different binding affinities for the ligand. This was deduced from the changes in the forms of Scatchard plots when the saturation assay was performed at different times at low temperature. Variability in the forms of Scatchard plots (linear to biphasic or vice versa) in samples obtained on different occasions from the same subjects also support this view. The apparent dissociation constants (mean values) were 150 and 550 pmol/l for the linear components of the biphasic plots and 300 pmol/l for the linear plot. These values lie well within the normal plasma concentrations of insulin. Addition of spermine to the incubation mixture was shown to further accentuate the high affinity part of the Scatchard plot. The high and low affinity forms of the receptor could provide an ideal means to rapidly regulate the response to insulin.

Erythrocytes↗
PubMed1984

Quality control of insulin radioreceptor assay for human erythrocytes. Effect of ageing of mono-125I-Tyr-A14-insulin preparation.

The quality control of insulin radioreceptor assay for human erythrocytes is based on the storage of erythrocyte preparations in Hepes buffer of pH 8.0, containing 10 g/l of albumin and 20 mmol/l of glucose. The change of erythrocytes into spherocytes and crenated cells reduces the apparent number of insulin receptors in a relatively constant way by less than 8% a week after 10 days of storage. At the same time the dissociation constants of the insulin-receptor complex increase rapidly. Thus the use of a preparation must be limited to controlling the determination of the insulin binding sites of erythrocytes, and not to the measurement of the affinities of the receptors. When mono-125I-Tyr-A14-insulin gets old, a slow decrease in the insulin binding sites can be measured, but the dissociation constants of the insulin receptor complex are not affected.

Erythrocytes↗
PubMed1984

Increase of serum angiotensin-converting enzyme activity after freezing.

A fluorometric assay [4] of angiotensin-converting enzyme (ACE) was adapted to a new fluorometric and nephelometric Transcon 102 FN analyser. The intraassay coefficient of variation for the method was 2.6% (n = 48). The corresponding interassay coefficient was 5.3% (n = 16). Freezing with subsequent thawing of serum increased its ACE activity by approximately 15%. This effect remained constant if serum samples were stored at -70 degrees C, but it disappeared within one month if the samples were kept at -20 degrees C.

Adult↗
PubMed1984

Acetylator phenotyping with sulphadimidine in patients receiving isoniazid.

The possible competition of isoniazid for the acetylation of sulphadimidine was studied by comparing the degree of acetylation of urine sulphadimidine (1 g orally) in isoniazid-treated and in isoniazid-untreated patients. The former group (isoniazid 300 mg once daily) consisted of 5 slow and 5 rapid acetylators and the latter group of 5 and 6 respective acetylator phenotypes. In all of the 4-8, 8-12 and 12-24 h urine fractions, the acetylation percentage of sulphadimidine and its distribution pattern were practically unaffected by the isoniazid. This suggests that isoniazid therapy does not interfere significantly with the routine acetylator phenotyping by means of sulphadimidine.

Acetylation↗
PubMed1983

Divergent effects of atenolol, practolol and propranolol on the peripheral metabolic changes induced by dynamic exercise in healthy men.

A study has been made of the effects of intravenous atenolol, practolol and propranolol on the changes induced by exhaustive dynamic physical exercise in blood pressure, heart rate and blood levels of lactate, glucose, insulin, free fatty acids and potassium. The mean endurance of dynamic exercise was reduced by all three beta-blockers, most markedly by propranolol. After all the beta-blockers heart rate showed a similar decrease during the first 60 min of exercise; atenolol caused the smallest reduction at exhaustion. All three beta-blockers lowered the systolic blood pressure during exercise; propranolol was the most active agent both during exercise and during recovery. The diastolic pressure was higher during exercise after treatment with the beta-blockers, especially propranolol. The beta-blockers did not markedly affect the elevation of blood lactate induced by exercise. The increase in blood glucose was abolished by atenolol. Plasma insulin was reduced by exercise after beta-blockade, most markedly after propranolol and practolol. All the beta-blockers were equipotent in reducing up to 60 min the exercise-induced increase in plasma free fatty acids, although at exhaustion propranolol had a significantly greater effect than atenolol or practolol. Serum potassium was higher after propranolol and atenolol than after practolol during exercise and recovery.

Adult↗
PubMed1983

Fibrinogen: a comparison of an immunoturbidimetric method with four conventional methods.

A rapid and simple immunochemical method for fibrinogen determination is described. The method is based on measuring the turbidity caused by antigen-antibody complexes with an enzyme analyser using diluted antiserum as a starting reagent. This immunoturbidimetric method correlates well with the immunodiffusion method and with two of the thrombin methods. Its correlation with the precipitation method according to Low was a little weaker.

Fibrinogen↗
PubMed1983

Serum lysosomal enzyme activities in silicosis and asbestosis.

The serum activities of two lysosomal enzymes, beta-N-acetylglucosaminidase (EC 3.2.1.30) and beta-glucuronidase (EC 3.2.1.31) were analyzed for 28 silicosis and 34 asbestosis patients. The enzyme activities of the patients were compared with those of age-, sex- and exposure-matched controls with no radiological signs of pneumoconiosis, and with an additional reference group of blood donors. The serum activity of beta-N-acetylglucosaminidase was higher in the silicosis patients (32.5 +/- 11.7 U/l) than in the asbestosis patients (21.7 +/- 7.9 U/l, p less than 0.001), in the silica exposed controls (27.1 +/- 6.7 U/l, p less than 0.05) or in the blood donors (24.8 +/- 6.3 U/l, p less than 0.05). No significant differences were found in the serum activity of beta-glucuronidase in the studied groups. Although the mechanisms causing different levels of serum beta-N-acetylglucosaminidase activity in silicosis and asbestosis patients remain unresolved, they may be related to the different mechanisms of action of the two dusts on lung (10).

Acetylglucosaminidase↗