EFFECTS OF HYPERTONIC SOLUTIONS AND OF MERCURIC CHLORIDE ON THE UPTAKE OF [14C]GLUCOSE ANALOGUES BY RABBIT BRAIN

Intracarotid perfusion of hypertonic solutions of urea, NaCl or acetamide increased the brain uptake index (BUI) of glucose analogues by rabbit brain, while isotonic urea was without effect. Lactamide, whether isotonic or hypertonic, decreased the BUI of glucose analogues. The increased BUI produced by the other hypertonic solutions could be inhibited by unlabeled substrate, unlabeled glucose or by phloridzin, and may reflect stimulated carrier-mediated transport of monosaccharides into brain. Although the increases could also have been due to altered cerebral blood flow, radioautography showed no gross evidence of such alterations. The BUI of 2-2-deoxy-D-[1-¹⁴C]glucose was decreased by intracarotid injection of 0.01mM HgCl₂, to the same level seen following maximal inhibition with unlabeled 2-deoxy-D-glucose, while 0.08mM HgCl₂ gave BUI's above this level. The lower concentration of HgCl₂ probably inhibited carrier-mediated monosaccharide transfer, while the higher concentration appeared to increase passive diffusion into the brain as well.     

Cerebral metabolic pattern in young adult Down's syndrome subjects: altered intercorrelations between regional rates of glucose utilization

ABSTRACT. Correlations between regional cerebral metabolic rates for glucose determined by pisitron emission tomography with [¹⁸F]-2-fluoro-2-deoxy-D-glucose, have heen used to indicate functional associations between pairs of brain regions. This method was applied to data from 14 healthy adult subjects with trisomy 21 Down's syndrome tape < 34 years) and from 24 age-matched healthy controls. Correlations were obtained between ratios of regional-to-global resting glucose utilization. In comparison to age-matched controls, the Down's svndrome group had many smaller correlations for region-pairs wilhin and between the frontal and parietal lubes, some correlations were large and negative in the Down's syndrome group, but large and positive in the controls. One region so affected was the inferior frontal gyrus thai includes Broca's area. This result is consistent with ihe relatively greater language impairment in Down's syndrome subjects. The thalamus also had smaller correlations with temporal and occipital regions in the Down's syndrome group compared: to controls. These results suggest that Down's syndrome is accompanied by a functional disruption of neural circuits associated with directed attention.     

Nephrotic syndrome and fibrillary glomerulonephritis

Laufer J, Augarten A, Szeinberg A, Rapoport J, Katzenelson D, Yahav Y (The Chaim Sheba Medical Center, Tel Hashomer, Affiliated to the Sackler School of Medicine, Tel Aviv, Israel). Nephrotic syndrome and fibrillary glomerulonephritis (Case Report). J Intern Med 1997; 242 : 83–6.
A 28-year-old female with cystic fibrosis presented with nephrotic syndrome and progressive renal failure. In addition, she complained of blurred vision and there was a purpuric skin eruption localized to her legs. A renal biopsy revealed fibrillary glomerulonephritis. Skin biopsy demonstrated swelling of capillary endothelium, thickening of arteriolar walls and deposition of IgA, C3 and fibrinogen by immunofluorescence. Opthalmoscopy and fluorescein angiography disclosed cotton wool spots with intraretinal haemorrhages and ischaemia of the macula. Albumin infusions resulted in worsening of eye symptoms and signs. The presence of these three clinicopathologic entities in a patient with CF may indicate the possibility of systemic involvement related to continued exposure to chronic bacterial lower lung infection.