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Biomedical subjects

M Puukka

Publications and source records attributed to M Puukka.

At least 19 recordsLinked to original sources

Highly sensitive determination of C-reactive protein on the Innotrac Aio! immunoanalyzer.

C-reactive protein (CRP) is a widely recognized indicator of inflammation. Prospective studies have shown that CRP can be used to predict the risk of future cardiovascular events in apparently healthy subjects. Clinical and laboratory studies have also shown that inflammation has an important role in the inititation, progression and destabilization of atheromas, which makes high-sensitivity CRP determinations valuable in cardiovascular risk assessment. Innotrac Aio! is a fully automated random-access immunoanalyzer using a unique all-in-one (Aio!) dry reagent concept and time-resolved fluorometric detection. In this study, the analytic performance of the Innotrac Aio! ultrasensitive CRP assay (usCRP) was evaluated. The analytical detection limit was 0.003 mg/L, the limit of quantification was <or= 0.03 mg/L and the carry-over result was within acceptable limits. Within-assay CVs obtained in lithium-heparin plasma at five concentrations ranged within 3.2 and 24.9%. Inter-assay precision using lithium-heparin plasma pools and commercial controls was 6.2-8.6% at concentrations of 0.17-33.3 mg/L. The inter-assay precision at a concentration of 0.04 mg/L using the serum pool was 67%. Regression analysis between Aio! usCRP and Cobas Integra CRP latex (Roche Diagnostics) using lithium-heparin plasma samples yielded the following results: correlation coefficient 0.983, slope 1.17 (< 50 mg/L) and correlation coefficient 0.974, slope 1.137 (< 10 mg/L). The correlation coefficient between Integra and Aio! usCRP assays using serum samples was 0.979 and the slope 1.106. Regresssion analysis between Aio! usCRP and Hitachi CRP (Latex) HS using serum samples revealed the following results: correlation coefficient 0.942, slope 0.879 (< 20 mg/L) and correlation coefficient 0.973, slope 0.983 (< 10 mg/L). EDTA whole blood samples correlated well with the corresponding plasma samples. Innotrac Aio! usCRP assay was found to be linear in the CRP concentration range of 0.09-62 mg/L. In the first quartile (0-25th percentile), 2nd quartile (25th-50th percentile), 3rd quartile (50th-75th percentile) and 4th quartile (75th-100th percentile), the mean CRP values were 0.16 mg/L, 0.52 mg/L, 1.24 mg/L and 4.39 mg/L, respectively.

Biomarkers↗

Physiological adaptations of the raccoon dog (Nyctereutes procyonoides) to seasonal fasting-fat and nitrogen metabolism and influence of continuous melatonin treatment.

The raccoon dog (Nyctereutes procyonoides) is a middle-sized canid with profound autumnal fattening followed by winter sleep. This study investigated the effects of prolonged fasting-induced winter sleep on the fat and nitrogen metabolism of the species. Half of the animals were treated with continuous-release melatonin implants to induce artificial short photoperiod. Autumnal accumulation of fat was characterized by low plasma free fatty acid (FFA), diacylglycerol (DG), and triacylglycerol (TG) levels. After transition to winter catabolism, the circulating lipid levels increased due to enhanced lipolysis. Two months of fasting resulted in a steady 3.1 kg weight loss (28% of body mass, 0.47% day(-1)). Storage fat was mobilized during the winter sleep reflected by the elevated FFA and DG concentrations. The lowered insulin levels could be a stimulator for TG hydrolysis. The plasma total amino acid concentrations, urea levels, and urea-creatinine ratios decreased due to fasting, whereas ammonia and total protein concentrations remained stable. The effects of melatonin on energy metabolism were modest. The results indicate that the raccoon dog is well adapted to long-term wintertime fasting utilizing fat as the principal metabolic fuel. The species can maintain its protein catabolism constant for at least 60 days. Decreased cortisol and thyroid hormone concentrations may contribute to protein sparing.

Adaptation, Physiological↗

Analytical performance of time-resolved fluorometry-based Innotrac Aio! cardiac marker immunoassays.

The results of an evaluation of the Innotrac Aio! cardiac markers are presented. This system is based on dry-chemistry, time-resolved fluorometry. All assay-specific reagents are dry-coated into assay-specific cups, and only the generic assay buffer is required. The levels of precision attained with pooled serum samples and control materials were acceptable for cTnI and CK-MB. Myoglobin assay showed higher CV, 5.6-9.5%. The linearity studies were performed in concentration ranges of 0.1-76 microg/L for cTnI, 0.7-450 microg/L for CK-MB and 0.6-1500 microg/L for myoglobin. The markers were found to be linear within the ranges tested. The correlation coefficient between the Aio! and AxSYM cTnI assays was 0.960, and the slope was 0.07. The correlation coefficients between the Aio! and AxSYM CK-MB and myoglobin assays were 0.995 and 0.971, respectively. They involved some differences in the measured concentrations (Aio! CK-MB was about 9% higher than AxSYM CK-MB, and Aio! myoglobin was 19% higher than AxSYM). Comparative studies with all the markers, using EDTA whole blood and lithium heparin plasma specimens and lithium heparin whole blood and plasma, yielded the following results: the slopes were close to 1.0 for all correlations, with the exception of that between CK-MB EDTA whole blood and lithium heparin (0.83). High correlation coefficients were obtained (> or = 0.97). The carryover results for all the cardiac markers were good, 0.0%, 0.0%, and 0.3% for cTnI, CK-MB, and myoglobin, respectively. The analytical detection limits were 0.01 microg/L for cTnI, 0.8 microg/L for CK-MB and 0.5 microg/L for myoglobin. The stability of the analytes in the lithium heparin samples at room temperature was also studied and was found to be decreased by from 10% (myoglobin and CK-MB) to 17% (cTnI) in 8 h. Innotrac Aio! provides a rapid and easy quantitative measurement of cardiac TnI, CK-MB, and myoglobin within < 18 min. This system is therefore suitable for use in emergency departments, coronary care units or central laboratory settings.

Biomarkers↗

The effect of a high-sucrose diet on dentin formation and dental caries in hyperinsulinemic rats.

A high-sucrose diet decreases dentin formation and its minerals, but the mechanisms behind the effect are largely unknown. We studied the combined and separate effects of sucrose and insulin on dentin formation and mineral metabolism in growing rats. At weaning, animals were randomized into 4 groups: control/sucrose diets both with and without external insulin (1 U/x 100 g body weight daily). After 4 weeks, we measured areas of dentin formation, numbers and areas of dentinal caries lesions, and serum and urine glucose, insulin, Ca, Na, K, and P. Exogenous insulin increased serum and urine insulin levels and decreased serum glucose level, but did not affect dentin formation or dentinal caries lesion formation or progression. A high-sucrose diet decreased dentin formation independently of insulin. The differences in serum and urine minerals between the groups were minor. The findings confirm that sucrose-diet-induced reduction in dentinogenesis is independent of insulin and loss of minerals in urine.

Analysis of Variance↗

The reducing effects of a calcium-deficient diet and high sucrose diet on dentin apposition of rat molars.

A high sucrose diet reduces dentin apposition of growing rats. The mechanisms of reduction are unclear, but disturbances in calcium balance or in mineralization of predentin may explain them. In this experiment, 29 Sprague-Dawley rats, 21 days old, were weaned and randomized into calcium-deficient, high-sucrose or standard-diet groups for 3 weeks. They were given food and water ad libitum. During the experiment, animals were individually housed in metabolic cages where urine samples were collected. At ages of 21 and 40 days mineralizing dentin was marked using I.P. injections of oxytetracycline hydrochloride. At 42 days of age, the animals were anesthetized and their blood was collected by cardiac puncture. Right hemimandibles were sectioned sagittally and left hemimandibles were fixed, decalcified, and cut into histological sections. Dentin appositions were measured planimetrically, predentin width, from histological sections. Ca, K, and Na levels of serum and urine were measured flame photimetrically and P levels were measured by the UV method. Statistical analyses were done using one-way analysis of variation (ANOVA) Tuckey's HSD t test. In the calcium-deficient group, hypocalcemia, reduced dentin apposition, and increased predentin width were noticed when compared with the control group (P<0.05). Also, the increase in predentin width, caused by calcium deficiency, was significant compared with sucrose-fed animals (P<0.05). Sucrose diet reduced dentinogenesis, increased Ca excretion to urine, but also reduced urinary levels of P, K, and Na, and the differences were significant for the controls (P<0.05). In conclusion, despite the same kind of reduced dentinogenesis in calcium-deficient and high-sucrose groups, calcium imbalance or reduced mineralization of predentin does not explain reduced dentinogenesis in sucrose-fed animals.

Animals↗

The effect of sucrose diet of rat dams on the dentine apposition and dental caries of their pups.

The purpose was to examine whether a sucrose diet in rat dams reduces dentine apposition and enhances dental caries in their pups. Sprague-Dawley rat pups were randomized into four groups on the day of birth. During the lactation period three dams received a standard rodent diet and three a diet containing 41% sucrose. At the age of 3 weeks the pups were weaned and given an intraperitoneal injection of oxytetracycline hydrochloride. During the experimental period, half of the pups of control dams received a sucrose diet (Cnt-Suc pups) and half of the pups of sucrose dams received a standard diet (Suc-Cnt pups). The pups in the other halves received the same diet as given to their dams during lactation (Cnt-Cnt and Suc-Suc pups). Urine samples were collected from dams and pups during the test periods. After 4 weeks the pups were killed, their blood was collected and their jaws sectioned sagittally. Dentine apposition was determined planimetrically and dental caries using Schiffs staining. Ca, K and Na of serum and urine were measured flame photometrically and P using an ultraviolet method. The lactational sucrose diet was associated with decreased P and Na excretion in the dams, and also with reduced dentine apposition in their pups. Reduced dentine apposition and induced Ca excretion with decreased P, K and Na excretions were observed in Suc-Suc pups and Cnt-Suc pups during the experiment period. Fewer intact teeth with more enamel and dentinal caries lesions occurred in sucrose-exposed groups (Suc-Cnt, Cnt-Suc and Suc-Suc pups). It was concluded that the sucrose diet given to dams during lactation changed the function of the pulp dentine complex of their pups leading to reduced dentinogenesis, but also predisposed to a reduction of dentinogenesis in pups during the experimental period and enhanced the occurrence of dental caries.

Analysis of Variance↗

Effects of a high sucrose diet and intragastric sucrose feeding on the dentinogenesis, dental caries, and mineral excretion of the young rat.

Previous studies show that a high sucrose diet reduces the rate of primary dentinogenesis and increases dental caries, although their cause-effect relationship is still obscure. The purpose of this study was to explore whether the effect of sucrose load on the dentinogenesis and dental caries of young rat molars is mediated by systemic (intragastric) or by systemic and local (dietary) factors. At weaning (19 days), animals were randomized into the control, intragastric sucrose, and dietary sucrose groups for 4 weeks. The areas of dentin appositions and dentinal caries lesions were measured planimetrically. Caries was also determined with Shiffs staining and the width of predentin by histology. Urinary Ca, K, and Na levels were measured by flame photometry, urinary P levels using an UV method, and serum insulin levels using radioimmunoassay. Systemic and local sucrose load reduced dentin appositions and intragastric sucrose increased urinary Ca excretion. No differences in the width of predentin were noticed. Only dietary sucrose enhanced the occurrence and progression of caries. The present findings show that sucrose load reduces dentinogenesis by impairing the synthesis of dentin matrix, but also point out the crucial importance of the local sucrose challenge in the initiation of dental caries.

Analysis of Variance↗

Multicentre evaluation of KONE Optima analysis system.

Optima from KONE Instruments Corporation is a new selective laboratory analyzer for turbidimetric, colorimetric and ion selective electrode measurements. Overall analytical performance of Optima and reagents provided by KONE was evaluated according to ECCLS guidelines, in a multicentre study involving four different laboratories, including substrates (cholesterol, high-density lipoprotein-cholesterol, creatinine), specific proteins (transferrin, IgG), enzyme activities (gamma-glutamyltransferase, alanine aminotransferase) and electrolytes (sodium, potassium, chloride). The results obtained attest good precision of the system for all the analytes tested: the range of within-run CV is 0.5 %-4.3 %, and range of between-day CV % is 0.8 %-7.9 % (median of four laboratories). Except for total cholesterol (5 % overestimation compared to the reference method) accuracy of measurement is adequate. Creatinine and uric acid assays were subjects of interference (defined as deviation > 10 % from target value) by bilirubin and haemoglobin respectively.

Blood Chemical Analysis↗

New method for the determination of pancreatic amylase evaluated.

We have carried out a multicenter evaluation of a new reagent carrier for Reflotron, specific for pancreatic amylase where the salivary isoenzyme is inhibited by two specific monoclonal antibodies. This new procedure combines easy handling with low imprecision (median CV less than 3%) in control material, serum, heparinized blood, and plasma) and close correlation (r = 0.991 to 0.999) with established manual and automated methods. The same close correlation was found with values obtained from either venous or capillary finger-stick blood. Salivary amylase up to 54 kU/L (37 degrees C) was inhibited to about 97%. Endogenous interference by hemoglobin, bilirubin, triglycerides, cholesterol, or hematocrit was found to be negligible within a wide range of interferent concentrations. Out of a panel of 28 commonly used drugs it was shown that only two (ascorbic acid and paracetamol), and then only at toxic concentrations, caused a deviation in amylase activity of greater than 10%. From the results of this study we conclude that this new method is suitable for highly precise and accurate measurements of pancreatic amylase in emergency and routine laboratories.

Amylases↗

Spice allergy: results of skin prick tests and RAST with spice extracts.

Skin prick tests (SPT) with freeze-dried spices and 5% (w/v) spice extracts were performed on 50 patients with 2+ or stronger SPT reactions to spices per se, and RAST were performed on 10 of them. Freeze-dried extracts produced mostly equal or stronger SPT reactions than corresponding whole spices, but 5% (w/v) extracts produced weaker reactions and also remained totally negative in some patients. Positive RAST results were seen in all 10 patients tested. The correlation between the RAST and SPT results was good for mustard and paprika, but poor for cayenne, coriander, caraway and white pepper. Five patients with positive SPT and RAST for spices contracted rhinitis from powdered spices in their working environments, and one patient suffered from gastrointestinal pains caused by spiced food. The others had noticed no clinical symptoms caused by spices. The present results thus indicate that both SPT and RAST should include purified spice extracts.

Adolescent↗

The effect of bupivacaine paracervical block on the neurobehavioural responses of newborn infants.

The effects of maternal bupivacaine paracervical block on neonatal neurobehavioural responses were studied at the ages of 3 h, 1 day, 2 days and 4-5 days. Subjects were healthy, term neonates born vaginally to 10 mothers with paracervical block and to 12 mothers without analgesia. No statistically significant differences were found in the responses between the groups. It is concluded that paracervical block with a small dose of bupivacaine, applied by experienced obstetricians to non-risk parturients with healthy foetuses, has no detrimental effects on newborn behaviour or neurological recovery.

Adult↗

Postnatal decrease in insulin binding to erythrocytes in infants of diabetic mothers.

To clarify the role of insulin receptors in the macrosomia and the tendency to hypoglycemia in infants of mothers with insulin-treated diabetes mellitus (IDM) we studied insulin binding in erythrocytes from mixed umbilical blood and from peripheral venous blood collected when the infants were 3-14 days old. Normal infants were matched for gestational and postnatal age. The IDM infants were macrosomic, with significantly higher birth weights relative to gestational age than the control infants. Plasma free insulin concentrations in cord blood were 15-fold higher in the IDM than in the normal infants and more than 3-fold higher in the peripheral venous blood at the median age of 4 days. Hypoglycemia occurred in 12 of the 17 IDM and in none of the normal infants. In umbilical blood insulin binding to erythrocytes was similar in the IDM and normal infants. In both groups insulin binding decreased during the first postnatal weeks, but the decrease was significantly greater in the IDM than in the normal infants. The decrease in insulin binding to erythrocytes was a consequence of decreased receptor affinity as well as decreased receptor concentration in the IDM infants, but was mainly due to decreased receptor concentration in the normal infants. We conclude that insulin binding to its erythrocyte receptor in cord blood in IDM infants is similar to that in normal infants in spite of the simultaneous gross hyperinsulinemia in the IDM infants. The resulting increase in insulin action would then contribute to the tendency toward hypoglycemia and may be partly responsible for the macrosomia in IDM infants. The marked postnatal decrease in insulin binding in IDM infants is a possible explanation for their diminishing risk of hypoglycemia after the first few days of life in spite of persisting hyperinsulinemia.

Birth Weight↗

The effect of segmental epidural analgesia on the neurobehavioural responses of newborn infants.

The effects of maternal segmental epidural analgesia on neonatal neurobehavioural responses were studied at the ages of 3 h, 1 day, 2 days and 4-5 days. Subjects were healthy, term neonates born vaginally to 14 mothers with an epidural block and to 15 mothers without analgesia. The only statistically significant differences were found at the age of 1 day, when the epidural group infants habituated and oriented better to inanimate auditory stimuli. It is concluded that segmental epidural analgesia with a low dose of bupivacaine can be regarded as being a safe obstetric analgesic method as regards neonatal behavioural responses.

Acoustic Stimulation↗

Levels of some purine metabolizing enzymes in lymphocytes from patients with Down's syndrome.

The activities of a number of purine metabolizing enzymes of erythrocytes and lymphocytes were determined in 18 subjects with Down's syndrome and in 18 age- and sex-matched control subjects. An increase of adenosine deaminase activity (adenosine or deoxyadenosine as substrates) was found in erythrocytes (P less than 0.001) as well as in lymphocytes (P less than 0.001) of Down's syndrome subjects compared to controls. The purine nucleoside phosphorylase activities in lymphocytes and plasma urate concentrations were also significantly higher in Down's syndrome subjects than in controls (P less than 0.001 and less than 0.02, respectively). Adenine phosphoribosyltransferase activities and hypoxanthine-guanine phosphoribosyltransferase activities in lymphocytes were identical in the two groups. In all subjects studied there were positive correlations between the erythrocyte adenosine deaminase activities, lymphocyte adenosine deaminase or deoxyadenosine activities, and plasma urate concentrations (P less than 0.05 in all cases), and between lymphocyte nucleoside phosphorylase and lymphocyte adenosine deaminase or deoxyadenosine deaminase activities (P less than 0.01 and less than 0.05, respectively). The results suggest that increased activities of some purine metabolizing enzymes found in both erythrocytes and lymphocytes may contribute to increased purine degradation and hyperuricemia in subjects with Down's syndrome. In addition, the increased adenosine deaminase and nucleoside phosphorylase activities may be related to the immunological dysfunction found in subjects with Down's syndrome.

Adenine Phosphoribosyltransferase↗

Erythrocyte insulin binding in preterm newborn infants.

To characterize the erythrocyte insulin receptor in newborn infants we studied the binding of 125I-insulin to the erythrocytes from 42 preterm infants (14 at birth, 14 aged 2-7 days, and 14 aged 8-16 days) with a mean gestational age of 34.1 wk, and from 32 term infants (16 at birth and 16 aged 2-7 days). The insulin binding to cord blood erythrocytes from preterm infants was significantly higher than that of cord blood cells from term infants and to postnatal cells from preterm as well as term infants. The erythrocytes from preterm infants aged 2-7 days bound more insulin than cells from preterm infants aged 8-16 days. The maximum insulin binding (specific insulin binding at tracer concentration of insulin) correlated negatively with the gestational age both at birth and over the 1st postnatal wk. In the preterm infants there was a strong negative correlation between the maximum insulin binding and postnatal age. The enhanced insulin binding to cord blood erythrocytes from preterm infants was due to both an increased receptor concentration and a high affinity for insulin. The increased affinity persisted over the 1st wk of life. In preterm infants older than 1 wk the insulin binding characteristics were basically similar to those in term newborn infants. In all infants studied the receptor concentration seemed to be postnatal age dependent while the receptor affinity was gestational age dependent. No correlation was found between the insulin binding data and the plasma concentrations of immunoreactive insulin or C-peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗

Maternal and fetal effects of low-dosage bupivacaine paracervical block.

Vasoconstriction of the uterine arteries, hypertonus of the uterus, and the direct toxic effects of a local anesthetic on the fetus or a combination of the above have been presented as etiological factors of fetal bradycardia following paracervical block. The reduce fetal side-effects a superficial and lowdosage technique of PCB have been advocated. We have studied the effects of 25 mg of bupivacaine PCB using the above technique on fetal heart rate pattern (FHR), fetal acid-base balance, uterine activity, placental blood flow and maternal and fetal plasma levels of bupivacaine in 38 patients. The analgesic effect of a single 25 mg of bupivacaine PCB was good in 76%, moderate in 12% and poor in 12% of the cases. No changes in maternal heart rate or in blood pressure were noted. Fetal bradycardia defined as a decrease of mean fetal heart rate of at least 20 bpm or an absolute rate less than 100 bpm and a duration greater than two minutes occurred in 12% of the cases. The mean amplitude of the baseline fetal heart rate variability decreased significantly after PCB and a silent pattern (an amplitude less than 5 bpm) was observed in 20% of the cases. The most frequent (27%) pathological finding in our study was the disappearance of FHR accelerations after PCB. Similarly early and late decelerations of FHR occurred more often after PCB than during the control period before the block. The fetal pH from scalp blood samples did not, on average, decrease after PCB, but did so in cases with fetal bradycardia. Intervillous blood flow as measured by the 133Xe washout method did not change when measured before and after PCB. In addition in three cases with fetal bradycardia the changes in the intervillous blood flow were minimal. No significant changes in the mean uterine tone, amplitude and frequency of contractions were observed after PCB. However, an obvious uterine hypertonus was observed after PCB was observed in three cases of fetal bradycardia but not in two other cases of bradycardia or in the 8 cases of silent FHR pattern. Mean maternal bupivacaine concentration 20 minutes after PCB was 0.14 +/- 0.06 microgram/ml and 0.07 +/- 0.04 microgram/ml at birth. Simultaneous fetal and umbilical venous and arterial concentrations were correspondingly 0.04 +/- 0.02 microgram/ml, 0.03 +/- 0.01 microgram/ml and 0.03 +/- 0.01 microgram/ml, and they were significantly lower than respective maternal concentrations.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗