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Biomedical subjects

J Olsson

Publications and source records attributed to J Olsson.

113 records · Page 7Linked to original sources
PubMedDate not supplied

Fungal volatiles as indicators of food and feeds spoilage.

Fungal growth leads to spoilage of food and animal feeds and to formation of mycotoxins and potentially allergenic spores. Fungi produce volatile compounds, during both primary and secondary metabolism, which can be used for detection and identification. Fungal volatiles from mainly Aspergillus, Fusarium, and Penicillium have been characterized with gas chromatography, mass spectrometry, and sensory analysis. Common volatiles are 2-methyl-1-propanol, 3-methyl-1-butanol, 1-octen-3-ol, 3-octanone, 3-methylfuran, ethyl acetate, and the malodorous 2-methyl-isoborneol and geosmin. Volatile sesquiterpenes can be used for taxonomic classification and species identification in Penicillium, as well as to indicate mycotoxin formation in Fusarium and Aspergillus. Developments in sensor technology have led to the construction of "electronic noses" (volatile compound mappers). Exposure of different nonspecific sensors to volatile compounds produces characteristic electrical signals. These are collected by a computer and processed by multivariate statistical methods or in an artificial neural network (ANN). Such systems can grade cereal grain with regard to presence of molds as efficiently as sensory panels evaluating grain odor. Volatile compound mapping can also be used to predict levels of ergosterol and fungal colony-forming units in grain. Further developments should make it possible to detect individual fungal species as well as the degree of mycotoxin contamination of food and animal feeds.

Animal Feed↗
PubMedDate not supplied

Age-related changes in immune parameters in a very old population of Swedish people: a longitudinal study.

This study used a longitudinal design to examine age-related changes in a well-defined sample of Swedish people ranging from 86 to 92 years of age at baseline. The longitudinal design encompassed three measurement occasions with 1 year intermeasurement intervals. The results were analyzed by multivariate analyses of variance (MANOVA), which is useful for comparing individuals over time. Healthy middle-aged subjects (39 years SD +/- 5.8) served as controls. The proliferative responses to Concanavalin A (Con A), a T-cell mitogen, indicated significant lower levels in responses of the old when the two groups were compared. The MANOVA revealed no significant change in mitogen responses over measurement occasions in the old sample as compared with the young. However, when cell types and lymphocyte subpopulations were examined, significant differences were found between the two age groups in many of these parameters and for some (lymphocyte percentages and numbers, CD3 numbers) the MANOVA indicated significant decreases over the measurement occasions in the very old. The results also consistently indicated significant intraindividual correlations in cell types, lymphocyte subpopulations, and mitogen responses over time.

Adult↗
PubMedDate not supplied

Rupture of the myocardial histoskeleton and its relation to sudden death after infusion of glycine 1.5% in the mouse.

Hypoxic lesions in the subendocardium and long-standing dilatation of the interstitium have been described after exposure of the heart to glycine 1.5%, which is a widely used irrigating medium in endoscopic surgery. To study if the hypo-osmotic properties of the fluid cause these morphological changes, whether their long duration can be explained by rupture of the histoskeleton and whether they promote sudden death, 75 mice received an intravenous infusion of 200 ml/kg or 300 ml/kg over 60 min of either glycine 1.5%, glycine 1.5% in normal saline, normal saline, or no fluid (controls). The animals were decapitated when they were dying from the infusion, or else 7 days later, and 69 hearts were examined by light microscopy and 4 by electron microscopy. Rupture of the histoskeleton and hypoxic lesions in the subendocardium were observed in 47% and 35%, repectively, of the mice given glycine 1.5%, while the incidence averaged 20% in the two other groups. Rupture occurred in 38% of the mice that died, in 23% of those that survived an infusion, and in 0% of the controls. Hypoxic changes correlated with bradycardia, which is a sign of glycine absorption in the clinic. In conclusion, rupture of the histoskeleton and hypoxic changes occur in the subendocardium of mice after volume loading. These morphological changes were aggravated by the hypo-osmotic properties of glycine 1.5%.

Animals↗