Effect of charcoal-containing cigarette filters on gas phase volatile organic compounds in mainstream cigarette smoke.

Of the chemicals identified to date in mainstream cigarette smoke with known toxicological properties, the volatile organic compounds (VOCs) are considered the most hazardous group owing to their high abundance and toxicity. In this research we evaluate a recently introduced line of cigarettes that contain charcoal in their filters. The amount of charcoal in these filters ranged from 45 mg to 180 mg and were either dispersed among the filter material or contained in a small cavity in the filter segment. Charcoal has long been used for removing VOCs from both water and air. Our findings indicate that these cigarettes reduce machine generated mainstream smoke deliveries of a wide range of VOCs compared to a similar, non-charcoal filtered, cigarette. However, this reduction is dependent not only on the amount of charcoal present but also on the volume of smoke being drawn through the filter. While a brand with 45 mg charcoal reduces VOC delivery under ISO smoking conditions, charcoal saturation and breakthrough occur under more intense smoking conditions. Breakthrough is minimised for brands with the most charcoal. Overall, the brands with the most charcoal are effective at reducing VOC deliveries under even intense smoking conditions.

Delivery of antimicrobials into parasites.

To eliminate apicomplexan parasites, inhibitory compounds must cross host cell, parasitophorous vacuole, and parasite membranes and cyst walls, making delivery challenging. Here, we show that short oligomers of arginine enter Toxoplasma gondii tachyzoites and encysted bradyzoites. Triclosan, which inhibits enoyl-ACP reductase (ENR), conjugated to arginine oligomers enters extracellular tachyzoites, host cells, tachyzoites inside parasitophorous vacuoles within host cells, extracellular bradyzoites, and bradyzoites within cysts. We identify, clone, and sequence T. gondii enr and produce and characterize enzymatically active, recombinant ENR. This enzyme has the requisite amino acids to bind triclosan. Triclosan released after conjugation to octaarginine via a readily hydrolyzable ester linkage inhibits ENR activity, tachyzoites in vitro, and tachyzoites in mice. Delivery of an inhibitor to a microorganism via conjugation to octaarginine provides an approach to transporting antimicrobials and other small molecules to sequestered parasites, a model system to characterize transport across multiple membrane barriers and structures, a widely applicable paradigm for treatment of active and encysted apicomplexan and other infections, and a generic proof of principle for a mechanism of medicine delivery.

Plasmodium falciparum: cyanide-resistant oxygen consumption.

It has been hypothesized that Plasmodium parasites utilize a branched chain respiratory pathway, consisting of a classical cyanide-sensitive branch and an alternative cyanide-resistant branch. To further explore this hypothesis, the effect of cyanide on Plasmodium falciparum was determined using a polarographic assay. The rate of oxygen consumption by saponin-freed parasites was approximately 5% that of control human white blood cells or of Toxoplasma gondii, consistent with an anabolic role for P. falciparum respiration. However, while all of the oxygen consumption of the control white blood cells and of T. gondii could be inhibited by cyanide, 25% of the oxygen consumption of the P. falciparum parasites was found to be insensitive to high concentrations of cyanide. The cyanide-resistant portion of the parasite oxygen consumption was completely inhibited by two inhibitors of alternative oxidase activities in other systems, propyl gallate and salicyclhydroxamic acid. These studies provide the first direct evidence for a branched chain respiratory pathway in P. falciparum. Furthermore, salicyclhydroxamic acid, propyl gallate, and related inhibitors of alternative oxidase activities were shown to inhibit the growth of P. falciparum in vitro. These results support the need for further investigation of alternative oxidase activity as an antimalarial chemotherapeutic target.

Prenatal sonographic diagnosis, assessment, and management of a fetus with a quadruple nuchal cord at 39 weeks' gestation.

A case of prenatal sonographic diagnosis of a quadruple nuchal cord is presented. Perinatal assessment included nonstress, oxytocin challenge testing, and Doppler velocimetry studies of the umbilical artery and fetal vibratory acoustic stimulation. Obstetric management of this case is discussed.

Organisms isolated from severe odontogenic soft tissue infections: their sensitivities to cefotetan and seven other antibiotics, and implications for therapy and prophylaxis.

Cefotetan is a new cephamycin antibiotic characterised by excellent B-lactamase stability and anti-anaerobe activity, coupled with a long half life of 3-4 h which permits twice daily dosage. A clinical trial of cefotetan in the treatment of severe oro-facial infections is presented, together with a detailed analysis of the causative organisms and their sensitivities to eight antibiotics. 50/50 patients achieved clinical cure with a treatment regime comprising cefotetan therapy and incision and drainage, with patients being transferred to oral cephradine for the final phase of therapy. Side effects were minimal and there were no instances of relapse. Significant resistance among alpha-haemolytic streptococci and bacteroides organisms to penicillin was observed. The streptococci were resistant due to mechanisms other than beta-lactamase production. In the light of these findings and the reports of other workers it is suggested that penicillin V may no longer be the most appropriate drug for endocarditis prophylaxis, despite the most recent recommendations of the American Heart Association. Furthermore, if penicillin V is used for this purpose, a penicillin free interval of 6-8 weeks may be inadequate before this drug is used. Cefotetan is not suitable for prophylaxis against endocarditis.

Juvenile hormone promotes dominance behavior and ovarian development in social wasps (Polistes annularis).

Repeated topical application of juvenile hormone to workers of the primitive social wasp, Polistes annularis resulted in a disruption of colony social structure as indicated by a sharp increase in the frequency of dominance interactions. Ovarian maturation was also observed, probably as both a direct and an indirect effect of hormone treatment.

Diatremes with kimberlitic affinities in north-central montana.

Diatremes in the Missouri River Breaks demonstrate systematic subsidence-ring structure, contain inclusions derived from far above and far below, and have been produced by gas-rich eruptions of alkalic ultramafic magmas. Similar magmas have produced diatremes in many localities in the world and are known to be closely associated with and probably parental to kimberlites.