פרסומים

Polymorphic transitions between the cryst. forms 4, 5, and 6 of coca butter (m. 27.5, 33.8, and 36.3°, resp.) were studied by differential scanning calorimetry and x-ray diffraction. The transitions were modified by surfactants of the Span and Tween type, mostly in favor of form 5. Expts. were also carried out on chocolate. There was little relation between polymorphic transition and bleaching. Bleaching seemed, however, related to the rate of cooling, and was due to the migration of a molten cocoa butter fraction to the surface. [on SciFinder(R)]

Surfactants prepd. by bromination of the double bonds of oleate groups of sorbitan monooleate (I), sorbitan trioleate (II), and polyoxyethylene derivs. of I and II were effective emulsifiers in the prepn. of oil-in-water emulsions. The HLB values of the brominated compds. were similar to those of starting compds. The use, formation, and the stability of emulsions were detd. [on SciFinder(R)]

A computer-based system for recording and analysing light microscope images, combined with classical cytogenetic analysis, has revealed the spatial organization of the giant chromosomes of Drosophila salivary gland cells. Each polytene chromosome arm folds up in a characteristic way, contacts the nuclear surface at specific sites and is topologically isolated from all other arms.

Crystal size distribution and the yield of Ca oxalate crystals were detd. in solns. with an admixt. of 5 normal and 3 stone forming urines. A pos. correlation was found between the median size and no. of particles and the overall inhibitory potentials of the urines toward Ca oxalate pptn. in vitro as reflected by discriminating index (DI) [sic] measurements. Incubation of 2 samples of stone formers' (SF) urines with glutamic-oxalacetic-transaminase (GOT) caused a redn. of aspartic acid concn., an increase in glutamic acid concn. and a parallel decrease in the DI values. After 90 min of SF urine incubation with GOT the DI in three samples was improved and both the median size and no. of particles were reduced, by 28% and 45% resp. These results could indicate that GOT activity changes the inhibitory power of the SF urine by transforming aspartic acid into glutamic acid, having thus most probably a part in the inhibition of Ca oxalate stone formation. [on SciFinder(R)]

Orange essential oil was emulsified with water in the presence of various food additives (xanthan gum [11138-66-2], sorbitan monolaurate [1338-39-2], sorbitan monooleate [1338-43-8], ethoxylated sorbitan monooleate [9005-65-6], sucrose diacetate hexaisobutyrate [126-13-6], tragacanth gum [9000-65-1], and ester gum 8BG) and tested for light scattering quality, opacity, and stability, to det. the proper emulsifying agents for use in creating cloudy emulsions in soft drink manuf. Best results were obtained by using combinations of ester gums and the emulsifying agents. [on SciFinder(R)]

The effects of normal human serum, insulin-like growth factor and β-d-xyloside on the synthesis of proteoglycan, as well as their differential effect on the synthesis of chondroitin sulfate and keratan sulfate side-chains, were studied in chick embryonal cartilage. The glycosaminoglycans found in the incubation medium were mainly intact carbohydrate moieties of partially degraded proteoglycan molecules, whereas the tissue-bound glycosaminoglycans were of intact proteoglycan molecules. In incubations with normal human serum, the synthesis of the chondroitin sulfate side-chains of the tissue-bound glycosaminoglycans was preferentially stimulated, while the percentage of medium glycosaminoglycan (out of the total glycosaminoglycan in tissue and medium) was reduced, compared to control incubations. In incubations with insulin-like growth factor, the synthesis of the keratan sulfate side-chains of the tissue-bound glycosaminoglycan was preferentially stimulated, whereas the percentage of t

The exptl. conditions to maintain metastability in a soln. of Ca oxalate during 15 min were defined. Seed crystals of uric acid and Na urate were added, and the decrease in Ca ion concn. was measured by a Ca-selective electrode. Na urate crystals caused a decrease of ∼14%, while uric acid seeds were inactive. The growth of Ca oxalate on Na urate surface was confirmed by x-ray emission anal. When glutamic acid was added at 4-5 ppm concn. to the metastable soln. contg. uric acid seeds, a ∼28% Ca-concn. decrease was obsd. The pptn. of Ca oxalate on uric acid was confirmed by x-ray emission anal. A structural fit at an at. level between 2 solids, which is a necessary condition for epitaxy, is not sufficient for growth to occur. An addnl. factor, namely attraction at an ionic or mol. level, is also needed. It may be furnished by a mediating agent compatible with both solids. [on SciFinder(R)]

Multiple (water-in-oil-in water) emulsions were prepd. by homogenizing 30 parts 1% NaCl with 70 parts of light mineral oil contg. varying amts. of Brij 92 emulsifier and then adding 20 parts of this primary emulsion to 80 parts of 5% glucose contg. varying amts. of mixts. of Span 20 [1338-39-2] and Tween 80 [9005-65-6] to provide hydrophile-lipophile balance (HLB) values of 9-15. At Tween-Span emulsifier mixt. concns. of 0.7-1.5% the yield of multiple emulsion was not affected by HLB value; droplet size detd. the yield. At emulsifier concns. \textgreater1.5% the yield decreased with increasing concn. at any HLB, related to a continuous decrease in multiple emulsion droplet size. Yields and emulsion stability were max. with an HLB value of 11 at emulsifier concns. \textgreater1.5%; at emulsifier mixt. concns. of 0.7-3% stability increased with increasing HLB value. Multiple emulsions are promising pharmaceutical forms. [on SciFinder(R)]