Rate of heat release and ignitability indices for surface linings

Dimensional analysis is applied to one form of fire growth in a compartment to derive two indices for the classification of linings, an ignitability index and a rate of heat release index, that can be combined into a fire growth parameter, which here is made proportional to the time to flashover in the internationally standardized Room/Corner Test. The ignitability index is the inverse of the time to ignition. The rate of heat release index is obtained by integrating the rate of heat release in time, weighted in such a way that the values of rate of heat release immediately after ignition are of higher importance than those at later times. Both indices are determined from test results of the Cone Calorimeter.     

Detection and partial characterization of bacteriocin in the methanotrophic bacterium Methylobacter bovis

The strain Methylobacter bovis 98 was selected among methanotrophic bacteria as one of the most active producers of secretory bacteriocin-like compounds. In the above strain this compound was shown to be a protein with a molecular weight of about 70 kD, relatively thermostable, having a bactericidal effect on closely related organisms. Its properties as a whole are consistent with the accepted definition of bacteriocins, which so far have not been found in this group of microorganisms. A methodical approach that combines electrophoretic separation of secretory proteins and testing their antibacterial activity directly in polyacrylamide gel allowed us for the first time to identify bacteriocin in methanotrophic bacterial culture.     

The role of NF-kappaB in the angiogenic response of coronary microvessel endothelial cells

The activation of nuclear factor (NF)-kappaB by 12(R)-hydroxyeicosatrienoic acid [12(R)-HETrE], an arachidonic acid metabolite with potent stereospecific proinflammatory and angiogenic properties, was examined and its role in the angiogenic response was determined in capillary endothelial cells derived from coronary microvessels. Electrophoretic mobility-shift assay of nuclear protein extracts from cells treated with 12(R)-HETrE demonstrated a rapid and stereospecific time- and concentration-dependent increase in the binding activity of NF-kappaB, which was inhibitable by the antioxidants N-acetylcysteine, butylated hydroxyanisole, and pyrrolidine dithiocarbamate and was partially attenuated by the protein kinase C inhibitors, staurosporine and calphostin C. Neither 12(S)-HETrE nor other related eicosanoids--e.g., 12(R)-HETE, 12(S)-HETE, and leukotriene B4--stimulated the activation of NF-kappaB relative to 12(R)-HETrE, substantiating the claim for a specific receptor-mediated mechanism. 12(R)-HETrE stimulated the formation of capillary-like cords of microvessel endothelial cells distinguishable from a control; this effect was comparable to that observed with basic fibroblast growth factor (bFGF). Inhibition of NF-kappaB activation resulted in inhibition of capillary-like formation of endothelial cells treated with 12(R)-HETrE by 80% but did not affect growth observed with bFGF. It is suggested that 12(R)-HETrE's angiogenic activity involves the activation of NF-kappaB, possibly via protein kinase C stimulation and the generation of reactive oxygen intermediates for downstream signaling.     

Different O-glycosylation of respiratory mucin glycopeptides from a patient with cystic fibrosis

The O-linked oligosaccharides from three fractions of highly glycosylated mucin glycopeptides obtained from sputum of a patient with cystic fibrosis were characterized and compared regarding size, composition, sequence and when possible linkage positions. Neutral and sialic acid-containing glycans were permethylated and analyzed by high-temperature GC-MS and MALDI-MS, showing more than 60 different oligosaccharides with a size of up to 15 monosaccharide units. Some of the observed oligosaccharides are novel for respiratory secretions, one being a trifucosylated heptasaccharide with the proposed structure: Fuc-Gal-4(Fuc-3)GlcNAc-(Fuc-)Gal-3GalNAcol. The glycosylation of two of the glycopeptide fractions was similar with regard to the neutral and sialylated oligosaccharides despite their different origins from the sol or gel phase. Analysis of the sulfated oligosaccharides by FAB-MS/MS indicated that the gel fraction contained C-6 linked sulfate groups while the two sol fractions also contained C-3 linked sulfate. The results suggest the presence of different glycosylated mucin domains, probably originating from different mucin glycoforms and/or apoproteins in the airway of cystic fibrosis patients.     

On the question of an electrokinetic requirement for phospholipase C action

The phospholipase C of clostridium welchii (alpha toxin) has an absolute requirement for trace quantities of Ca2+. It attacks pure phosphatidylcholine particles (smectic mesophases) having a close-packed bilayer structure only when their surface zeta potential is made positive by the addition of certain divalent ions (e.g., Ca2+) to the aqueous phase or by the presence of low concentrations of long chain cations to the lipid. Alternatively, if the rotational freedom of individual phospholipid molecules is increased by the insertion of short n-alkanols (e.g., hexanol) into the bilayer or when a monolayer of the substrate at an air/water interface is expended, enzymic hydrolysis can occur without any requirement for a net postive charge on the surface.     

Morphology of the male accessory organs of reproduction of immature fallow deer (Dama dama L.) with particular reference to puberty and antler development

Cutting the suspensory ligament reduced the ovarian content of norepinephrine (NE) to less than half that of controls and only a few blood vessels had perivascular fibers and an occasional nerve remained in the interstitial gland. Cutting the ovarian plexus had a less drastic, but similar effect on the ovarian content of NE and on the pattern of ovarian adrenergic nerves. Cutting both the suspensory ligament and ovarian plexus eliminated visualization of ovarian adrenergic nerves, but some ovarian NE was still measurable. Fluorescence and electron microscopic studies of the suspensory ligament revealed a large adrenergic nerve embedded in smooth muscle of the ligament. The nerve was also acetylcholinesterase-positive. Cutting the celiac plexus or incising a small nerve lateral to the plexus and medial to the origin of the suspensory ligament, had the same effect on the ovarian adrenergic nerves as cutting the suspensory ligament. It is concluded that the extrinsic adrenergic nerves to the rat ovary reach the organ by two routes: one via the nerve in the suspensory ligament (superior ovarian nerve), and one via the traditionally described ovarian plexus along the ovarian artery.