פרסומים

The authors report the case of a 15-year-old female who presented with a history of vague but constant pain about the medial aspect of her right knee. X-ray established the presence of an expanding lesion in the medial tibial plateau. Computerized axial tomography (CT) and magnetic resonance imaging (MRI) were used in the evaluation of the lesion. The authors compare the preoperative CT and MRI findings with the microscopic histopathology of the amputation specimen and note that the CT scan underestimated the extent of the microscopic tumor boundaries, whereas MRI showed altered activity beyond these boundaries.

Describes the "Computer Software Inquiry Inventory" (CSI), which was designed for content analysis of inquiry-based science computer software. Explains the five basic features of the instrument. Includes analyses of two programs using the CSI categories of evaluation. (ML)

Introduction Cationic polyelectrolytes play important roles in many biological systems. Histones [20] and cationic proteins of lysosomal origin [8, 18, 24, 25, 28, 33, 36, 37], both rich in arginine, and synthetic poly a-amino acids [3, 4, 5, 6, 23, 30] have been shown to be bactericidal and cytotoxic to a variety of bacteria and mammalian cells. In addition, these compounds modulate blood coagulation [30] and fibrinolysis [10]; agglutinate bacteria and mammalian cells [30]; modulate chemotaxis [16]; enhance adherence of mammalian cells to surfaces [26]; function as opsonins for phagocytosis by both "professional" and "nonprofessional" cells [3,5,6,17,27,28,34]; activate autolytic cell wall enzymes of Staphylococci [15]; and block Fe receptors for IgG upon certain group A Streptococci [14]. More recent studies have shown that histone-opsonized bacteria induced intense Iuminot- dependent chemiluminescence (LDCL) in human polymorphonuclear leukocytes (PMNs) and mouse peritoneal macrophages [In Furthermore, poly-i.-arginine collaborated with mixtures of lectins, calcium ionophore and the chemotactic peptide formyl-methionyl-Ieucyl-phenylalanine to induce synergistic LDCL and superoxide production in human PMNs [12,13]. Thus, arginine-rich polyelectrolytes appear to participate in many cellular functions related to host defenses against infection, presumably by mechanisms involving electrostatic interactions and ligand- receptor coupling phenomena. The objective of this present study was to investigate the possibility that arginine- rich polycations might facilitate the introduction of a variety of agents into eukaryotic cells. For this purpose, we have studied phagocytosis by Entamoeba histolytica of Candida albicans, and by Acanthamoeba palestinensis of Mycobacterium marinum.

Unsatd. fatty acids of soybean and castor oils were isomerized to conjugated forms and thermally polymd. or crosslinked to obtain emulsifiers for oil-water emulsions. The emulsifying agents were prepd. in 3 ways. The oil was transesterified with glycerol to obtain mono/diglycerides which were heated to 290° to give crosslinked polyglycerol esters. The emulsifiers were also prepd. by treating the soybean or castor oil with polyglycerols previously prepd. The 3rd case involved crosslinking the oil by a transesterification reaction 12 h at 290° to give a dimerized oil which was then transesterified with polyglycerol. A mixt. contg. 3% of the above-prepd. crosslinked polyglycerol esters, 40% water, and 50% soybean oil was easily emulsified to form a nonviscous stable water-in-oil emulsion. [on SciFinder(R)]

Food Grade Rutile (TiO2) was dispersed in coconut oil with the help of hydrophobic emulsifiers such as sorbitan esters and lecithin. The dispersed mixt. was melted and blended with hydrophilic emulsifiers such as ethoxylated sorbitan esters and the preheated (60°) blend was further sprayed by atomizer into cold water (20°). The oil-in-water emulsions contained encapsulated TiO2 in the internal phase. The technique is simple and allows prepn. of stable emulsions with av. droplets size of 1-10 $μ$. [on SciFinder(R)]