The effect of temperature on microbial fermentation in blood was studied. Specimens of human blood from a blood bank were inoculated with Candida albicans, an organism capable of causing fermentation. A preservative was added to a portion of the inoculated specimens. These inoculated specimens, as well as uninoculated blood, were stored under various temperature conditions. Production of ethyl alcohol was monitored over a period of six months. Fermentation was found to be highly temperature dependent, with refrigeration proving to be most effective at inhibiting ethanol formation.
A study was undertaken to determine if a relatively minor modification of our existing specimen collection tubes could enhance the long-term stability of blood cocaine. We added cocaine, benzoylecgonine (BE) and ethanol to whole sheep blood in glass tubes that were prepared to contain one of several combinations of preservatives and anticoagulant.
On day 1 and at intervals of up to one year, the drugs were measured by gas chromatography-mass spectrometry (cocaine and BE) or headspace gas chromatography (ethanol). Storage of blood containing 200 ng/mL cocaine at 4°C for one year resulted in 100% loss of the drug using our normal 10 mL specimen collection tubes containing 100 mg sodium fluoride and 20 mg potassium oxalate. The substitution of oxalic acid for potassium oxalate reduced this loss to 76% without any significant effect on the benzoylecgonine or ethanol concentrations. Further addition of 10 mg echothiophate iodide, a quaternary ammonium compound, brought the cocaine loss down to 60% of the original concentration by one year. Further work will be required to determine if oxalic acid and/or echothiophate iodide could be used in blood collection vials intended for forensic toxicological purposes without any detrimental effect on other assays.
A partial amino-acid sequence of Bacillus subtilis 168 flagellin is presented. The region of unassigned sequence in this 304-residue polypeptide chain spans residues 158-173. Comparison of the 27-residue aminoterminal CNBr peptide of B. subtilis 168 flagellin with that derived from the flagellin of the serologically unrelated strain of B. subtilis, W23, shows only three conservative substitutions, whereas the 16-residue carboxyl-terminal peptides derived from these flagellins were identical. The comparison of the very limited sequence information available on the flagellins of Salmonella and Proteus with that on B. subtilis indicates homology between these proteins.Flagellins derived from flagella of varying gross morphology, isolated from a large number of both peritrichously and polarly flagellated bacterial species, possess a number of common features. In each organism, the flagellar filaments are composed of a single type of protein subunit. The molecular Weights of these subunits range, in the main, from 33 to 40,000. The amino-acid compositions of numerous highly purified flagellins show an absence of tryptophan and half-cystine, and a low content of aromatic amino acids (1-4).These similarities may represent the residuum of a common ancestry shared by this class of proteins. Evidence of such an interrelationship may still be discernible in the aminoacid sequences of flagellins obtained from unrelated organisms.For Salmonella (1, 6) and Bacillus subtilis (7) Single amino-acid substitutions leading to altered flagellar morphology have been reported both for Salmonella (8) and for B. subtilis 168 (9). In the latter case, a mutation producing flagella lacking the wild-type long period helix appears to result from the substitution of a valyl for an alanyl residue at a single position in the primary sequence of flagellin (9).The above considerations, as well as the fact that knowledge of the primary structure of flagellin is a prerequisite to future attempts to determine the conformation of the mono-
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.