פרסומים

A salt water slurry of Dunaliella parva, an halophilic alga, was treated to convert it into C6H6-sol. material, as rich as possible in C and H. Several features obsd. were: 25% of the combined C can be extd. under mild conditions of pressure (atm.) and temp.; the presence of CO as well as transition-metal salts has only minor effect on the conversion and the compn. of the product; and ≤75% of the combined C is converted by in-situ presence of C6H6 during the pyrolysis of the alga-salt water slurry. [on SciFinder(R)]

The effect of solvents on the crystal structure of pure stearic acid crystd. from them was studied using x-ray and DTA. The latent heat of the phase transition, $Δ$Ht, was measured for the two well-defined forms B and C. X-ray diffractograms are the means for the identification of crystal modifications. However, only qual. information about the compn. present in the mixt. is inferred from the relative peak intensities. DTA of the phase transitions at 54° (for B) and 64° (for A) furnishes quant. data for each component present in the mixt. Values of 0 and 4.9 cal g-1 for the phase transition enthalpies were measured for the pure C form and B form, resp. Intermediate values were found for mixts. of C and B. The interplay between the crystn. conditions (type of solvent, cooling rate, and flow regime) dictates the formation of various crystal structure modifications. [on SciFinder(R)]

A std. bakers' grade wheat flour contg. 11.5% protein was mixed with various concns. of Na stearoyl-2-lactylate (SSL) [25383-99-7], Ca stearoyl-2-lactylate [5793-94-2], isostearoyl-2-lactylate [76021-79-9], SSL-Span 60 [1338-41-6] (3-7:7-3), SSL-Polysorbate 60 [9005-67-8] (1-3:1), or a mixt. of monoglyceride stearate [31566-31-1] and diglyceride stearate [1323-83-7], and farinog., extensog., and baking quality measurements were made. Best overall results were obtained with 0.5% SSL, Ca stearoyl-2-lactylate, or SSL-Span 60 (7:3), which induced a 10-15% increase in loaf vol. as compared to controls without emulsifiers. Flour with 0.5% mono- and diglyceride stearate added produced a relatively poor quality product. [on SciFinder(R)]

The crystal size and the length to width ratio of nitrofurantoin (I) [67-20-9] can be controlled using an appropriate mixt. of solvents and suitable crystn. conditions. DMF formed undesirable complexes with I while with HCO2H [64-18-6] no crystal structure modification or complexation was detected. The length (y) to width (x) ratio of I varies from 2.5 to 1.5 when crystd. from pure HCO2H or in a mixt. with H2O or EtOH [64-17-5]. The y/x values corresponded to the solvent interactions and supersatn. The crystal growth regularity is ascribed to the solvent power and thus when more regular crystals will ppt. bioavailability and solubilization of the drug will increase. Best results were obtained when a mixt. of HCO2H-EtOH (2:1) soln. was used as the crystn. media yielding large tabular crystals. [on SciFinder(R)]

A new method is described for following the inhibitory effect in artificial urine of polymeric dicarboxylic amino acids and other polyanionic derivs. on Ca oxalate crystn. The technique is based on using a Ca-specific electrode to measure Ca++ ion activity in soln. to assess the formation of Ca oxalate ppt. The retardation effect of poly-L-glutamic acid Na salt and poly-L-aspartic acid Na salt occurred in a 5-100 ppm concn. range. Blocking of the free carboxylic groups on the polymers eliminated the retardation effect. The retardation appears to be an inhibition of seed crystal growth rate. Normal urine retarded the pptn. but pathol. urine did not. [on SciFinder(R)]

Human polymorphonuclear leukocytes (PMN) chemotaxis was tested during exposure to leukocyte and platelet extracts, a variety of polyelectrolytes, inflammatory exudates, and bacterial products. The chemoattractants employed were either zymosan-activated serum or supernatant from autolyzed Staphylococcus aureus. Chemotaxis to both chemoattractants was markedly inhibited by leukocyte and platelet extracts; inflammatory exudates; anionic polyelectrolytes, DNA, hyaluronic acid, liquoid; and by cationic polyelectrolytes, histone, protamine base, protamine sulfate, and myeloperoxidase. Inhibition was also found with elastase, collagenase, pepstatin, and epsilon-amino-caproic acid. Bacterial products, such as lipoteichoic acid and lipopolysaccharides, and extracts of human dental plaque inhibited chemotaxis. No inhibition of chemotaxis was observed with heparin (< 10 micrograms/ml), chondroitin sulfate, phosphatidylethanolamine and phospatidylserine. Indeed, chondroitin sulfate markedly enhanced chemotaxis and antagonized the inhibitory effect of leukocyte or platelet extract. None of the agents employed was toxic to PMN as judged by trypan blue exclusion. These observations suggest that cationic polyelectrolytes and inflammatory exudates influence PMN surfaces, modifying interaction with chemoattractants. Assessment of the role of PMN chemotaxis in host defense against microbial invaders requires evaluation of the response in the presence of agents likely to be present in inflamed tissues.