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Biomedical subjects

I Ericson

Publications and source records attributed to I Ericson.

8 recordsLinked to original sources

Levels of brominated flame retardants in Northern Fulmar (Fulmarus glacialis) eggs from the Faroe Islands.

Eggs from Northern Fulmars (Fulmarus glacialis) were sampled in the Faroe Islands. The content of the brominated flame retardants tri- to decabromodiphenyl ethers (BDEs) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were determined in nine samples in concentrations ranging from non-detectable to 7 ng g-1(l.w.). The BDE levels were similar as in an earlier study of BDE levels in the fulmar eggs from the Faroe Islands but 10-1000 times lower compared to studies of eggs from seabirds and birds of prey from Europe. The two hexaBDEs #153 and #154 were the most abundant congeners, which represented around 50% of the total mean BDE concentration. The levels of BDE #209 were below the limit of detection (1.24 ng g-1 l.w.) except for one sample, which showed a concentration of 7.18 ng g-1 l.w. BTBPE was detected in eight samples and the mean level was 0.11 ng g-1 l.w. This concentration was 150 times lower than the average total BDE concentration (including BDEs #28, #47, #100, #99, #154, #153, #183, #209). BTBPE has only been detected once before in biota. Also other bromo-containing compounds were detected in the fulmar eggs. One group identified was the polybrominated biphenyls (PBBs), but because of the absence of reference standards in the lab, these could not be quantified.

Animals↗

Phospholipid and fatty acid composition in mitochondria from spinach (Spinacia oleracea) leaves and petioles. A comparative study.

Essentially chlorophyll-free mitochondria from photosynthetic (leaf) and non-photosynthetic tissue (petiole) were isolated from spinach (Spinacia oleracea). Leaf mitochondria were found to contain more phosphatidylcholine than phosphatidylethanolamine compared with petiole mitochondria. Galactolipids were found in small and equal amounts (5 mol of galactolipids/100 mol of galactolipids and phospholipids) in both leaf and petiole mitochondria. Fatty acid composition showed a significant difference in the amounts of C18:2 and C18:3 acids. The C18:2/C18:3 ratio was more than twice as high in all of the phospholipids studied from petiole mitochondria compared with the ratio in leaf mitochondria. More than 50% (mol/100 mol) of the fatty acids in the major lipids (phosphatidylcholine, phosphatidylethanolamine and cardiolipin) in petiole mitochondria were C18:2. In the minor lipids (phosphatidylinositol and phosphatidylglycerol), C16:0 dominated in both leaf and petiole mitochondria.

Fatty Acids↗

The regulation of exogenous NAD(P)H oxidation in spinach (Spinacia oleracea) leaf mitochondria by pH and cations.

Essentially chlorophyll-free mitochondria were isolated from green leaves of spinach (Spinacia oleracea L. cv. Viking II). Uncoupled oxidation of exogenous NADPH (1 mM) to oxygen had an optimum at pH 6.0, and activity was relatively low at pH 7.0, even in the presence of 1 mM-CaCl2. There was a proportional increase in the apparent Km for NADPH with decreasing H+ concentrations, suggesting that NADPH protonated on the 2'-phosphate group was the true substrate. Exogenous NADH was oxidized by oxygen with an optimum at pH 6.9. Under low-cation conditions, EGTA or EDTA (both 1 mM) had no effect on the Vmax. of NADH oxidation, although the removal of bivalent cations from the membrane surface by the chelators could be observed by use of 9-aminoacridine fluorescence. In contrast, under high-cation conditions, chelators lowered the Vmax. by about 50%, probably due to a better approach of the negatively charged chelators to the negative membrane surface than under low-cation conditions. In a low-cation medium, the Vmax. of NADH oxidation was increased by about 50% by the addition of cations. This was caused by a lowering of the size of the negative surface potential through charge screening. In contrast with other cations, La3+ inhibited NADH oxidation, possibly through binding to lipids essential for NADH oxidation. The apparent Km for NADH varied 6-fold in response to changes in the size of the surface potential, suggesting that the approach of the negatively charged NADH to the active site is hampered by the negative surface potential. The results demonstrate that the spinach leaf cell can regulate the mitochondrial NAD(P)H oxidation through several mechanisms: the pH; the cation concentration in general; and the concentration of Ca2+ in particular. The results also emphasize the importance of electrostatic considerations when investigating the kinetic behaviour of membrane-bound enzymes.

Cations↗

Oxidation of Glycine via the Respiratory Chain in Mitochondria Prepared from Different Parts of Spinach.

Mitochondria were prepared from roots, stalks, leaves, and leaf veins of spinach. The mitochondrial preparations were examined for their ability to oxidize glycine via the respiratory chain. It is shown that the glycine-oxidizing capacity is restricted to photosynthetically active tissue. The activity is present in mitochondria from the green parts of the leaves, but not in mitochondria from roots, stalks, or leaf veins.

Journal Article↗

Method to Obtain a Chlorophyll-free Preparation of Intact Mitochondria from Spinach Leaves.

Mitochondria from green leaves of spinach have been prepared using a three-step procedure involving differential centrifugation, partition in an aqueous dextran polyethylene glycol two-phase system and Percoll gradient centrifugation. The mitochondrial fractions after the different steps of purification were compared. The final mitochondrial preparation was totally free from chloroplast material measured as chlorophyll content. The enrichment of mitochondria in relation to peroxisomes and microsomes was approximately 12 and 33 times, respectively, based on NAD:isocitrate dehydrogenase activity, glycolate oxidase activity, and NADPH:cytochrome c oxidoreductase activity. The apparent intactness of the inner and the outer mitochondrial membranes was higher than 90% as measured by latency of enzyme activities. The mitochondria showed high respiratory rates with respiratory control and the ADP/O ratios approached the theoretical limits.

Journal Article↗

What constitutes good care for people with dementia?

Person-centred care for people with dementia is an aspiration of both family and professional carers, but what constitutes person-centred care and how it can be achieved is less clear. This article describes a Swedish study in which in-depth interviews were completed with both family and professional carers of people with dementia with the purpose of exploring what they considered to be "best care". Important areas of similarity and difference were identified and the results suggest that both groups of carers need to work closely together if person-centred care is to become a reality.

Attitude of Health Personnel↗