[Diagnostic value of multislice perfusion CT in dementia patients]. / Bedeutung der zerebralen Perfusionsmessung am Mehrzeilenspiral-CT in der Demenzdiagnostik.

BACKGROUND: The diagnostic value of perfusion CT in dementia patients was retrospectively evaluated in comparison to the Mini-Mental State Examination (MMSE). MATERIAL AND METHODS: The perfusion CT database of 55 subjects was investigated. All patients underwent an unenhanced, contrast-enhanced, and perfusion CT of the head. The clinical evaluation of the degree of dementia was performed with the MMSE. In the perfusion CT data, 24 ROI were marked. Then blood volume (BV), blood flow (BF), and mean transit time (MTT) were calculated and compared with the ipsilateral and contralateral regions and with the degree of dementia. RESULTS: With increasing degree of dementia, a significant decrease of the occipital and temporal BV was found. A significant decrease of the BF in the frontal lobe, basal ganglia, and occipital region was found. Concurrently, the MTT increased significantly in the basal ganglia region. The group with Alzheimer's disease showed significant regional hypoperfusion compared with the group of cognitively normal subjects in the frontal, basal ganglia, occipital, and temporal region. CONCLUSIONS: The cerebral perfusion decreased with increasing degree of dementia. The inexpensive and widely available perfusion CT reveals information about regional differences of cerebral perfusion, which may be useful in differentiating severity and types of dementia.

Lactoferrin turnover in man.

1. The turnover of 125I-labelled lactoferrin was measured in ten adults. Simultaneous organ radioactivity counting was performed. 2. Ferrokinetic studies were performed in three adults after the intravenous injection of [59Fe]lactoferrin. 3. Lactoferrin was rapidly eliminated from the plasma with a mean fractional catabolic rate of 5.7/day. Apolactoferrin (one subject) was eliminated at a slower rate (fractional catabolic rate 1.22/day). 4. Of the administered 125I label 99% was recovered in the urine, as free iodine, within the first 24 h. In the 59Fe studies no appreciable activity was found in the urine. 5. Organ radioactivity counting showed that lactoferrin was rapidly taken up by the liver and spleen. In the 125I studies the rapid excretion of free 125I suggested catabolism at these sites. In the 59Fe studies, the radioactivity persisted in the liver and spleen for several weeks and was slowly transferred to the bone marrow before appearing in circulating erythrocytes. 6. From the values of fractional catabolic rate, plasma lactoferrin, neutrophil lactoferrin and plasma volume, a 'derived neutrophil turnover' was calculated for each subject. The mean value was 8 x 10(8) neutrophils/day. This is about 1% the value obtained from the actual measurement of labelled cells. It is postulated that this 'derived value' represents only that portion of neutrophil turnover accounted for by intravascular senescence.

Lactoferrin content of peripheral blood cells.

The peripheral blood of 60 normal adults was separated into plasma, red cells, neutrophils, lymphocytes, monocytes and platelets. Lactoferrin concentrations were measured in the plasma and cell extracts and compared to those of lysozyme. The neutrophil lactoferrin content in males and post-menopausal females was found to be significantly higher than in pre-menopausal females. A small amount of lactoferrin was found in association with monocytes, but not with lymphocytes, erythrocytes and platelets. Neutrophil lysozyme concentrations did not exhibit any variation with sex and age; but the level in monocytes was higher than that in neutrophils. No correlation was observed between individual neutrophil lactoferrin values and the plasma level. Immunofluorescent studies showed neutrophils to have a lobulated pattern suggestive of nuclear staining. Monocytes did not show direct staining, but exhibited a peripheral pattern after prior exposure to lactoferrin--confirming the existence of a surface receptor. Gel chromatography indicated that neutrophil lactoferrin is in a polymerized or complexed form which elutes with the void volume on Sephadex G-200; serum lactoferrin consists of two forms, one of which also elutes with the void volume on Sephadex G-200.