[Toxic aluminum encephalopathy. Predominant involvement of the limbic system on MRI]. / Encéphalopathie toxique à l'aluminium. Atteinte prédominante du système limbique en IRM.

Two patients underwent acoustic schwannoma surgery by transmastoid approach. Petrous bone defect was filled in with aluminium-containing bone cement (Ionocem). A pseudomeningocele by CSF accumulation in subcutaneous temporoparietal area appeared after the procedure and, in subsequent weeks, encephalopathy with confusion and seizures. MRI showed cerebral involvement with herpes-like disposition. Temporal stereotactic biopsy in a case did not confirm viral encephalitis but disclosed cellular accumulation of lipofucsin and particles highly suggestive of aluminum-inclusions. Aluminium's levels in blood and CSF of both patients were very high and confirm the brain's toxic involvement. Aluminium's toxicity would be advocated in patients with neurologic disorders who have undergone maxillofacial or skull bone-cementoplasty by an aluminum-containing biomaterial, if this cement is in contact with CSF.

Precipitation and characterization of an aluminosilicate from AlCl3-Na2SiO3-HCl in serum, of interest for Alzheimer disease.

A precipitation experiment was performed with human serum to model aluminosilicate formation in brains of patients with Alzheimer disease. Aluminum and (or) silicate ions were added to serum in a 1:2 molar ratio at pH 7.4. Precipitates formed immediately and were left for 24 h at 37 degrees C before filtration. Silicate and aluminosilicate formed precipitates with human serum proteins albumin, transferrin, and IgG. In untreated samples, the IgG/albumin ratio increased slightly compared with the ratio in dried serum. Diethylbarbiturate-washed precipitates had a significantly lower protein content than did untreated ones. The IgG/albumin ratio increased considerably in the sample containing aluminosilicate. We conclude that IgG is the sodium dodecyl sulfate-soluble human protein most firmly bound to the aluminosilicate matrix. From 27Al magic-angle-spinning nuclear magnetic resonance (MAS NMR), a pronounced peak was found at 52.79 ppm and a minor peak at 0.53 ppm, suggesting that 4-coordinated aluminum predominates and that 6-coordinated aluminum is present in a smaller proportion. The 29Si MAS NMR spectrum shows a poorly ordered structure. The aluminosilicate formed also contains the cations Na+ > K+ > Ca2+ > Mg2+ and anions Cl- > PO4(3-). Rather than looking for aluminum toxicity to explain the effects of Alzheimer disease, one should consider that by precipitating such a composite phase, the balance of cations, anions, and proteins in human serum is changing.

Effect of feeding various levels of sodium zeolite A on milk yield, milk composition and blood profiles in thermally stressed Holstein cows.

Mid-lactation Holstein cows (n = 48) were equally and randomly assigned to one of four feeding treatments of sodium zeolite-A (SZA). SZA was mixed in a grain mixture (50:50 grain to forage ratio) of 0% (control), 0.5%, 1.0% and 1.5% SZA on a dry matter intake basis. Cows were fed alfalfa hay in the first phase and corn silage in the second phase of the study as roughage sources. Milk samples were taken three times weekly (am and pm) and analyzed for milk fat, protein and lactose with blood profiles conducted from samples collected weekly. SZA significantly (P less than .05) increased feed intake at all three levels for both diets. Milk yield was significantly (P less than .05) greater in the alfalfa diet. However, milk fat percent and percent protein were greater (P less than .05) in the corn silage diet. The addition of SZA to the corn silage diet increased (P less than .05) milk fat percent at the 1.0% level and milk protein at the 1.5% level. Calcium in milk was significantly (P less than .01) increased and respiration rates significantly lowered (P less than .05) in both diets at the 1.0% level. Serum calcium was higher (P less than .05) at the 1.0 and 1.5% level in the hay diet and the 1.5% level in the corn silage diet. Also, serum glucose and alkaline phosphate levels were significantly (P less than .05) higher in the corn silage diet.