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Biomedical subjects

A Kallner

Publications and source records attributed to A Kallner.

At least 109 records · Page 6Linked to original sources
PubMed1983

An experimental study of social isolation of elderly people: psychoendocrine and metabolic effects.

Psychoendocrine and metabolic effects of social isolation and understimulation in real life were examined in a controlled study of 60 elderly people representative of their age group. Together with the staff and the elderly, a social activation program was formed at a senior citizen apartment building. Half of the elderly were part of this activation program (experimental group). The other half constituted the control group. Blood sampling and psychosocial testing were performed immediately before and after 3 and 6 months of social activation. Social activation increased threefold in the experimental group. Height decreased in the control group compared to the experimental subjects. Plasma levels of testosterone, dehydroepiandrosterone, and estradiol increased significantly in the experimental group over the 6-month period compared to the control group. The most pronounced increase took place during the initial 3 months. Hemoglobin A1c decreased significantly in the experimental group over the 6-month period compared to the control group. In this preliminary study it is concluded that social isolation and understimulation may be associated with a wide range of psychophysiologic effects in elderly people.

Aged↗
PubMed1983

Influence of vitamin C status on the urinary excretion of catecholamines in stress.

A group of volunteers on a low intake of ascorbate was compared with another group supplemented with 3 g of ascorbate daily with regard to urinary excretion of catecholamines and cortisol after exposure to a specified stressor. The low-dose group excreted less adrenaline than the high-dose group, whereas excretion of dopamine, noradrenaline and cortisol was largely unchanged. This effect may indicate another role in vivo of vitamin C in the biosynthesis of catecholamines besides that of a cofactor to a specific enzyme. The results suggest a role for ascorbate in an adequate response to stress.

Adult↗
PubMed1982

The influence of aging on hemoglobin A1c (HbA1c).

Hemoglobin A1c (HbA1c) was used as a marker of transient increases in plasma glucose over the preceding 8 to 12 weeks in 48 nondiabetics between the ages of 50 and 89 years. A major finding is the lack of any significant differences in fasting plasma glucose with age, whereas HbA1c differed significantly between the age groups 50 to 69, 70 to 79, and 80 to 89 years. The lowest values, 6.9 +/- .48%, were found among the youngest age group, whereas the highest, 8.62 +/- .28%, were found in those 80 to 89 years of age.

Aged↗
PubMed1981

Utilization and metabolic effects of a conventional and a single-solution regimen in postoperative total parenteral nutrition.

A comparison was made of the effects of two intravenous regimens for postoperative total parenteral nutrition, namely, a conventional (control) regimen (group I) and a single-solution regimen of the same composition (group II). The effects examined were: hemoglobin concentration, prothrombin time, serum protein and electrolyte concentrations, and nitrogen and electrolyte balances. The 18 patients undergoing abdominal surgery were allocated at random to the two groups and the experiment was run for 3 days. During the day of the operation and the next 3 days both groups showed a decrease in the hemoglobin concentration and in the serum levels of iron, albumin, transferrin and cholesterol, while the asparagine aminotransferase increased. During total parenteral nutrition the prothrombin time and erythrocyte sedimentation rate increased in both groups. The nitrogen balance improved gradually in both groups and on the 3rd day was positive in group II. The calcium and magnesium balances indicated a higher retention and the phosphate balance a lower retention of these ions in group II than in group I. The urinary phosphate excretion rate during total parenteral nutrition decreased in both groups. This study indicates that the single-solution regimens used in intravenous nutrition caused no adverse metabolic effects and was used as efficiently as a conventional regimen in the early postoperative period.

Abdomen↗
PubMed1981

Accuracy of some routine method used in clinical chemistry as judged by isotope dilution-mass spectrometry.

Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was used for accuracy control in 64 participating laboratories in Sweden. Mean values ("state-of-the-art" values) were obtained for creatinine, cholesterol, glucose, urea, uric acid, and cortisol. These values were compared with values obtained with highly accurate reference methods based on isotope dilution-mass spectrometry. Differences were marked in the case of determination of creatinine and cortisol. Concerning the other components, the differences between the state-of-the-art value and the values obtained with the reference methods were negligible. Moreover, the glucose oxidase and the oxime methods for determination of glucose and urea were found to give significantly lower values than the hexokinase and urease methods, respectively. We conclude that methods with a higher degree of accuracy are required for routine determination of creatinine and cortisol.

Blood Chemical Analysis↗
PubMed1980

Rhythmic changes in estriol excretion during pregnancy.

Different biologic rhythms with effect on one and the same parameter may cause a complicated signal pattern in which no regularity can be visually identified. In this study an autocorrelation function approach, well established in the interpretation of electroencephalograms, was shown to be applicable also in the interpretation of processes with few points of observation. This technique, used on the excretion of estriol in urine, reveals several rhythms with wavelengths between 6 and 72 hours. Interference between these signals may explain the irregular visual appearance of plots of subsequent estriol determinations and the considerable rise and fall of urinary estriol excretion during pregnancy. The presence of two independent sources of the rhythms is suggested. It is concluded that the complicated and individual rhythmic changes in urinary excretion of estriol results in a low diagnostic specificity for fetoplacental malfunction of this component.

Circadian Rhythm↗
PubMed1980

A comparison between Finnish immigrants and native Swedes in the greater Stockholm region-social and medical risk indicators of ischemic heart disease.

A random sample of 105 Finnish 35-59-year-old male immigrants in the catchment area of Huddinge hospital was drawn and 105 age- and sex-matched native Swedes living in the same area. From the Finnish 71 participated and from the Swedes, 77. Most immigrants had been residing in the region for many years. Many had grown up in medium-sized municipalities in Finland, particularly in the province of Karelia. They differed from the native Swedes with regard to many social variables. Thus, the immigrants had lower incomes, were more frequently exposed to noise at work and reported more sickness absenteeism during the year preceding the study. The immigrants had significantly more often than the native Swedes at least one conventional risk indicator of ischemic heart disease. They were also demonstrated to have abnormally low high density lipoprotein cholesterol levels significantly more frequently than native Swedes. Several of the variables studied did not differentiate the groups from one another. Thus, there was no indication of any difference in total alcohol ingestion or in Type A behaviour prevalence.

Adult↗
PubMed1980

Use of isotope dilution--mass spectrometry for accuracy control of different routine methods used in clinical chemistry.

Serum from patients was pooled, filtered, dispensed and frozen. The serum pool obtained was used for accuracy control in twenty-one participating laboratories in the Stockholm area. Mean values (state of art values) were obtained for creatinine, cholesterol, glucose, urea and uric acid. These values were compared with values obtained with highly accurate reference methods, based on isotope dilution--mass fragmentography. The most marked difference was found in the case of determination of creatinine. It is suggested that immediate access to such a well-defined human serum might decrease the need for conventional interlaboratory control programmes.

Blood Glucose↗
PubMed1980

Interlaboratory evaluation of four RIA kits for determination of plasma cortisol, with special reference to accuracy: influence of matrix in calibration standards.

We used four RIA kits for determination of plasma cortisol to assay 12 plasma samples in four laboratories, and compared the results with those obtained with a highly accurate method based on isotope dilution/mass spectrometry. All kits (Farmos, NEN, Sorin, and Clinical Assays) showed 10-50% deviation from the comparison method in the normal range (200-700 nmol/L). The inter- and intralaboratory imprecision (CV) ranged between 8-27% and 5-11%, respectively. Possible explanations for this low accuracy are discussed. Retention of an intact biological matrix in the calibration standards seems to be one prerequisite for accuracy.

Humans↗
PubMed1979

Steady-state turnover and body pool of ascorbic acid in man.

The time course of radioactivity in plasma and urine after oral administration of a single dose of (1-14C)ascorbic acid has been followed in healthy nonsmoking male volunteers. The investigation was carried out under steady state conditions with regard to ascorbic acid intake (30 to 180 mg/day). Using pharmacokinetic principles, turnover, pool size, and rates of metabolism and excretion could be calculated. It was found that the half-life of ascorbic acid was inversely related to the dosage and that the pool could be increased to about 20 mg/kg bodyweight by increasing the dosage. It was concluded that on a daily intake of about 100 mg ascorbic acid this pool size would be reached in 95% of the population.

Adult↗
PubMed1978

Effects of ascorbic acid deficiency on adrenal mitochondrial hydroxylations in guinea pigs.

The effect of ascorbic acid deficiency on adrenal hydroxylation of cholesterol and deoxycorticosterone in guinea pigs was studied by using mitochondria and isolated cytochrome P-450 fractions. The effects obtained were compared with the effects of long-term treatment with ACTH. Advanced scurvy as well as treatment with ACTH resulted in an increase in the weight of the adrenals, the total amount of cytochrome P-450, the cholesterol side-chain cleavage activity, the cortisol level in plasma, and the excretion of unconjugated cortisol in urine. Total 11beta- and 18-hydroxylation of deoxycorticosterone were not stimulated or were stimulated only to a small extent. It is suggested that the major effects observed in advanced scurvy are due to ACTH, the level of which was significantly increased, most probably as a consequence of the stress. In animals kept on a scorbutogenic diet for 2-4 weeks or, with a small dose of ascorbate added, for several weeks, changes were observed that could not be fully explained as effects of ACTH on normal adrenals. Although the plasma levels of ACTH and cortisol were increased only to a small extent and excretion of unconjugated cortisol in urine was unaffected, there was a significant increase in the total capacity of adrenal mitochondria to hydroxylate exogenous cholesterol. It is concluded that the level of ascorbate in the adrenals might be of some importance for the capacity to convert cholesterol into pregnenolone. The normal feed-back regulation is, however, intact in moderate ascorbate deficiency and the plasma level of cortisol is kept within normal limits.

Adrenal Glands↗
PubMed1977

Removal of background interference in nephelometric determination of serum proteins.

By precipitation of beta-lipoprotein by a dextran sulphate and calcium chloride mixture the background light scattering in continuous flow nephelometric systems can be reduced to such a level that it can be neglected in practice. No loss of IgG, IgA, IgM, orosomucoid or transferrin on precipitation could be demonstrated. The supernatant could not be used for immunoelectrophoresis or radial immunodiffusion in analysis of these proteins since significantly lower values were obtained for some of them than in native serum.

Blood Proteins↗