Purification and some characteristics of a calcium-binding protein from Bacillus cereus spores

A novel calcium-binding protein has been purified from the dormant spores of Bacillus cereus T. Purity of this protein was verified by SDS-PAGE and reversed-phase HPLC. Its calcium-binding ability was verified by a competitive calcium-binding assay using Chelex-100 resin and 45Ca autoradiography. The protein is heat-stable and is retained by hydrophobic matrices (phenyl-Sepharose) in a calcium-dependent manner. SDS-PAGE and amino acid composition indicate the molecular mass of the protein to be 24 kDa.     

Distribution of the superficial temporal artery in the Chinese adult.

The superficial temporal artery is important in head and neck surgery. Ethnologic variation may affect surgical procedure. In this study, we evaluated the variations of the artery in Chinese adults. We measured its bifurcating location, the diameter of its vessels, and its relationship to nearby structures. A total of 26 cadavers with 52 superficial temporal arteries were examined in 3 consecutive years. The superficial temporal artery ran 1.14 cm anteriorly to the bony external auditory canal. The average diameters of the superficial temporal artery, frontal branch, and parietal branch were 2.14, 1.61, and 1.68 mm, respectively. In 45 of 52 cases (86.5 percent), bifurcation of the artery occurred well above the zygomatic arch. The present study thus demonstrated that the superficial temporal artery in the Chinese adult differs from that in the Caucasian and has provided a detailed anatomic distribution analysis of the superficial temporal artery in Chinese adults, which should benefit the clinician in dealing with operation procedures related to this artery.     

Effect of mucin on the pharmacokinetics of antibiotics in the rat

The intramuscular pharmacokinetics of ticarcillin and amikacin in rats receiving 1 ml of 5% mucin suspension (equivalent to 250 mg/kg) administered intraperitoneally were not altered compared with the control animals. However, it is important to investigate the effect of mucin on the pharmacokinetics of antimicrobial agents in animals which are used to evaluate the efficacy of the agents.     

The inhibitory effect of oral administration of garlic on experimental carcinogenesis in hamster buccal pouches by DMBA painting

The inhibitory effect of oral administration of garlic on experimental carcinogenesis in buccal pouches induced by painting 9,10-dimethyl-1,2-benz(a)anthracene (DMBA) was studied on 40 golden Syrian hamsters. The animals were grouped at random into four experimental groups (oral administration of garlic, NTP, BP or mineral oil followed by DMBA painting on buccal pouches), three chemical control groups (oral administration of garlic, NTP or BP without DMBA painting) and a DMBA control group (only painted DMBA on buccal pouches). Starting from the fourth week after DMBA painting, the pouch mucosae were examined biweekly for its tumor formation and blood vessel architecture. Animals were sacrificed 25 weeks after DMBA application. Tumors and pouch mucosae were dissected to examine tumor nature and biochemical reactions of DNA synthesis and GGTase activity. The inhibitory efficacy of garlic, BP and NTP were evaluated according to the results of these examinations. Garlic was found to have a higher inhibitory efficacy than BP and NTP through the probable mechanism of competitive binding with nuclear DNA and diminishing the opportunity of DMBA to initiate carcinogenesis. Other factors related to cancer inhibition included insufficient local blood flow, low GGTase activity and lesser DNA synthesis. The inhibitory effect of fractions of garlic on experimental carcinogenesis should be a reasonable and necessary continuation in future studies of the series of cancer prevention by garlic.     

Comparative screening of recombinant antigen thermostability for improved leptospirosis vaccine design

Recombinant antigens exhibit targeted protectiveproperties and offer important opportunities in the development of therapeutic technologies. Biophysical and structural methods have become important tools for the rational design and engineering of improved antigen-based vaccines. Vaccines containing Leptospira immunoglobulin-like (Lig) protein-derived antigens are currently the most promising candidates for protective immunity against the globally prevalent bacterial pathogen, Leptospira interrogans; however, vaccine trials using these domains have produced inconsistent results. Here, we compare the thermostability of domains from the main immunogenic regions from major leptospiral antigens, LigA and LigB. By measuring temperature-dependent fluorescence decay of the hydrophobic core tryptophan, 17 individual Lig protein immunoglobulin-like (Ig-like) domains were shown to display a broad range of unfolding temperatures. For a majority of the domains, stability issues begin to occur at physiologically relevant temperatures. A set of chimeric Ig-like domains was used to establish the ability of transplanted domain regions to enhance thermostability. Further insights into the determinants for domain stabilization were explored with nuclear magnetic resonance dynamics and mutational analysis. The current study has yielded a set of thermostable Ig-like domain scaffolds for use in engineering antigen-based vaccines and demonstrates the importance of incorporating thermostability screening as a design parameter.