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Biomedical subjects

H Tikkanen

Publications and source records attributed to H Tikkanen.

14 recordsLinked to original sources
PubMed2001

Cloning and characterization of a fifth human lysyl oxidase isoenzyme: the third member of the lysyl oxidase-related subfamily with four scavenger receptor cysteine-rich domains.

We report the complete cDNA sequence of the human lysyl oxidase-like 4 (LOXL4) gene, a new member of the lysyl oxidase (LO) gene family. The predicted polypeptide is 756 amino acids long, including a 24-residue signal peptide. The C-terminal region contains a LO domain similar to those of LOX, LOXL, LOXL2 and LOXL3. The N-terminal region has four subregions similar to scavenger receptor cysteine-rich domains that are highly conserved with LOXL2 and LOXL3. The LOXL4 mRNA is approximately 4 kb in size and is expressed in many tissues, the highest levels among the tissues studied being in the skeletal muscle, testis and pancreas. Recombinant LOXL4 expressed in HT-1080 cells was secreted into the culture medium with no evident proteolytic processing.

Amino Acid Oxidoreductases↗
PubMed1998

Poor reproducibility of exercise test in assessment of claudication.

To assess reproducibility of the exercise test in intermittent claudication, a prospective, comparative, randomized study was undertaken. Ten patients with stable intermittent claudication of ischaemic origin were exercised on a flat surface (0-Ex), with 12% steady inclination (12-Ex) and with progressively increasing inclination (p-Ex) in a random order during three different sessions. The ankle-brachial index (ABI) at rest and after exercise (rABI, exABI), initial and maximum walking distance (IWD, MWD) and metabolic equivalent (MET) were obtained as the main outcome measures. The results were analysed using intraindividual coefficients of variation (CVs) and standard deviations (SDs). The ABI values of the worst extremity were used in evaluation of results. Reproducibility of the exercise ABI appeared to be good, especially during progressively increasing exercise, the mean CV being 9 +/- 5%. The best mean CV was observed during p-Ex (16% +/- 14%) for maximum walking distance. The mean CV for initial walking distances ranged from 30% to 54%. Treadmill exercise testing to measure walking distances is highly inaccurate and the value of exercise on the flat treadmill should be questioned. Graded exercise appeared to be the most reproducible in this respect. The ABI after exercise, however, was a reliable single parameter when assessing arterial insufficiency causing decreased walking capacity.

Aged↗
PubMed1994

Effect of digital edge-enhancement on the visibility of normal parenchymal lung markings.

Digital 'conventional-like' (C-L) and edge-enhanced (E-E) posteroanterior chest roentgenograms of 42 healthy individuals were ranked twice (interval of at least 5 days) in the order of increasing lung parenchymal markings (a total of four rankings). This was done by three radiologists, two residents, one medical student and one radiographer. There was a good general consistency of rankings for both the C-L and E-E images. The correlation coefficients were best (median 0.600) (P < 0.05) between the consequent rankings of C-L images compared to the subsequent rankings of E-E images (median 0.440) and to the various combinations between the rankings of both kinds of images. Subtle differences in normal lung parenchyma could, therefore, generally (five of the seven observers) best be demonstrated in C-L images, but two observers managed best with the E-E images.

Adult↗
PubMed1993

Progressive unilateral hypertrophic myopathy: a case study.

A 12-year-old girl had progressive unilateral muscle hypertrophy limited to the sole, tibialis anterior, and biceps femoris muscles. The affected muscles showed complex repetitive discharges by electromyography, necrosis and variation of fiber size upon histopathological examination, and increased metabolic activity in biochemical studies. The findings suggest a myopathic origin, but the actual cause remains unknown.

Child↗
PubMed1993

Observed lung markings in normal chest roentgenograms.

The digital chest posterior-anterior roentgenograms of 42 healthy individuals were ranked twice (interval of at least 5 days) in the order of increasing lung parenchymal markings. The evaluations were made by three radiologists, two residents, a medical student and a radiographer. All observers regardless of their radiological experience showed good intraobserver correlations between their two subsequent rankings (p < 0.05-0.001). The interobserver agreement on rankings was generally poor, even if the radiologists were considered. Radiologic training seemed to eliminate the influence of false leading factors (the object's respiration and body constitution). "The golden standard of evaluation" (= the added-up rankings by the radiologists) did not correlate either with the patient's ages (19-54 years) or smoking habits (0-45 pack-years, mean 4.2).

Adult↗
PubMed1992

Fatty acid-induced increase in serum dialyzable free thyroxine after physical exercise: implication for nonthyroidal illness.

In 14 healthy males, prolonged running exercise resulted in a mean 25% increase in serum free T4 (FT4) concentration (P less than 0.001) which was significantly correlated (P less than 0.01-0.02) with an over 5-fold increase in the concentration of serum FFA and the FFA/albumin molar ratio. Hemoconcentration, as reflected in a mean 19% increase in serum albumin, caused an increase in serum T4-binding globulin and therefore also in serum total T4. As there was no change in the serum T4/T4-binding globulin molar ratio, the rise in serum FT4 was probably not caused, or only partly caused, by an exercise-induced shift of T4 from the extravascular to the intravascular compartment. Neither is it likely that the mean 41% increase in serum TSH observed after exercise, partly owing to hemoconcentration, was the reason for the increase in serum FT4 and T4 as there was no correlation between the increases in the TSH and thyroid hormone levels. Further support for the assumption that the elevation in serum FT4 after exercise was FFA-induced was provided by the observation that addition of 2.5 mmol/L oleic acid to normal serum in vitro resulted in a 33% increase in serum FT4 (P less than 0.001). There is an association between increased concentrations of serum FT4 and unsaturated FFA in patients with various nonthyroidal illnesses according to earlier observations, but it is unlikely, in the light of the present data from healthy subjects, that FFA are directly involved in raising the serum FT4 concentration in nonthyroidal illnesses patients unless the serum FFA concentration exceeds 2 mmol/L or the FFA/albumin molar ratio rises above 2.5.

Adult↗
PubMed1992

Measuring radiation exposure during percutaneous drainages: can shoulder dosemeters be used to estimate finger doses?

Some previous studies have shown remarkably high finger doses to radiologists performing percutaneous drainage under fluoroscopy. To assess the possible need for extra finger dosemeters in addition to the general dosemeter, radiologists' and assistants' radiation exposure at both shoulders and at the third fingers of both hands were recorded using thermoluminescent dosemeters during 27 interventional drainage procedures. Under couch screening was used. Mean dose rates were calculated by dividing the doses by the screening time. The dose rates for the sites measured were correlated with each other. The radiologists' bilateral finger dose rates did not correlate with each other; nor did dose rates between the left shoulder and the right hand. The radiologists' dose rates at both shoulders, however, correlated with each other, as did the shoulder dose rates with the dose rates at the ispilateral hand. The right shoulder dose rates correlated with the left hand dose rates. The assistants' dose rates at the places of measurement all showed significant correlations with each other. It is therefore concluded that radiologists involved in percutaneous drainages should use finger dosemeters on both hands; for assistants this may not be necessary.

Drainage↗
PubMed1989

Gastric emptying and serum insulin levels after intake of glucose-polymer solutions.

To examine the gastric emptying characteristics of four drinks varying in carbohydrate composition and concentration, five men ingested 600 ml of one of the different drinks on four separate occasions. All drinks contained Na+ 71 mmol.l-1, Cl- 60 mmol.l-1, Mg+2 5 mmol.l-1 and citrate 7 mmol.l-1; the carbohydrate component was either 3% glucose, 3% glucose-polymer (GP), 5% GP or 10% GP. With 99mTc-diethylene-triaminepenta-acetic acid (DTPA) as a marker, a scintillation camera and computer were used to measure the rate of gastric emptying. The half-emptying times (T 1/2) were inversely related to the glucose content of the solutions. The T 1/2 for 3% PG was 22.4 +/- 4.4 min (mean +/- SE) and for 10% GP 50 +/- 3.3 min (p less than 0.005). There was no significant difference in T 1/2 between the 3% glucose and 3% GP solutions. The increments in blood glucose (highest blood levels from 7.4 +/- 0.3 mmol.l-1 to 8.9 +/- 0.8 mmol.l-1), serum insulin (from 28 +/- 6 mU.l-1 to 77 +/- 13 mU.l-1) and C-peptide (from 3.6 +/- 0.4 micrograms.l-1 to 5.8 +/- 0.9 micrograms.l-1) were related to the amount of carbohydrate ingested. In all cases the serum insulin levels were high enough to inhibit the liberation of free fatty acids from the adipose tissue. It is concluded that the amount of carbohydrate in glucosyl units in the solution is a major determinant of gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

High-carbohydrate diet for long distance runners--a practical view-point.

The nutritional value of a high-carbohydrate diet was evaluated. Seven male marathon runners kept a food record diary for the three days preceeding two endurance races. They were instructed in how to compose a diet which contained about 9 g carbohydrate day-1 kg body weight-1. Sixty three per cent of the subjects' total energy intake was derived from carbohydrates. The dietary intake of vitamin C was six times the Recommended Daily Dietary Allowances (RDA). Intakes of thiamin, riboflavin, calcium, magnesium and iron were more than twofold, and niacin intake 1,4-fold compared to the allowances. The diet contained sufficient amounts of carbohydrate to refill and enlarge muscle glycogen stores. Moreover the nutritional value was high, and therefore this kind of a diet can be recommended to endurance athletes even on a daily basis.

Adult↗
PubMed1987

Serum lipoproteins, sex hormones and sex hormone binding globulin in middle-aged men of different physical fitness and risk of coronary heart disease.

Serum concentrations of lipoproteins, apolipoprotein A-I (Apo A-I), androgens, including biologically active free testosterone (free T), and sex hormone binding globulin (SHBG) and their associations were studied in 3 groups of men of different physical fitness and risk of CHD, consisting of male CHD patients, joggers and healthy controls. Of the 3 study groups, men with angiographically assessed CHD had the lowest HDL-C (P less than 0.002) and highest LDL-C and triglyceride (TG) levels (P = 0.05 and P less than 0.001) and lower 5 alpha-dihydrotestosterone (5 alpha-DHT) levels than joggers (P less than 0.02). Joggers had the highest serum high density lipoprotein cholesterol (HDL-C), Apo A-I and SHBG levels and lowest serum low density lipoprotein cholesterol (LDL-C) compared to the other groups (P less than 0.01). In correlation analysis 5 alpha-DHT was the most significant positive determinant of HDL-C and Apo A-I levels in CHD patients (r = 0.56 and r = 0.55, respectively, P less than 0.05). Moreover, SHBG was significantly positively correlated to both HDL-C and Apo A-I levels in patients, in the whole study group and in healthy men separately (r = 0.37-0.52, P less than 0.01). These significant correlations were also confirmed when age variation and differences in body mass index and smoking were controlled in multivariate analysis and in addition, in multivariate analysis both serum free and total testosterone were inversely related to serum triglyceride (TG) levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗