Comparison between the radial forearm and superficial circumflex iliac artery perforator free flaps for oral soft tissue reconstruction.

The radial forearm free flap (RFFF) is widely used for oral reconstruction. The superficial circumflex iliac artery perforator (SCIP) flap is an increasingly utilized alternative. The cases of 165 patients who received either an RFFF or SCIP flap for oral reconstruction at Chris O'Brien Lifehouse, Sydney were reviewed. The aim was to report on patient, pathology, treatment, and outcome variables and to compare these between the two flap groups. A RFFF was used in 126 patients and a SCIP flap in 39 patients. SCIP flap patients were younger (P < 0.001) and had shorter operative times (P < 0.001), shorter anaesthetic times (P < 0.001), and more frequent recipient site dehiscence (P = 0.005) when compared to RFFF patients. The SCIP flap was significantly less frequently used for composite resections including bone when compared to the RFFF (P < 0.001). The primary site distribution was more even for RFFF patients (P < 0.001). There were no SCIP flap failures; three RFFF failures occurred. SCIP flaps performed comparably in terms of operative and clinical outcomes. Most SCIP flaps were utilized in younger patients with partial glossectomy defects.

Towards universal ambient ionization: direct elemental analysis of solid substrates using microwave plasma ionization.

A microwave plasma was used for direct ambient ionization mass spectrometry of solid substrates, rapidly yielding atomic spectra without sample digestion or pre-treatment. Further, molecular spectra for the organic components of the substrate were obtained simultaneously, in an ambient ionization format. Initial characterization of the microwave plasma coupling to an ion trap mass spectrometer was carried out using solution standards and a microwave plasma torch (MPT) configuration. The configuration of the microwave plasma was then optimized for ambient ionization. The atomic and organic composition for samples applicable to nuclear and conventional forensic screening, including explosive/radionuclide mixtures and inorganic/organic gunshot residue component mixtures were successfully determined. The technologies employed are readily fieldable; the feasibility of a multimode ion source that could be coupled with a portable ion trap mass spectrometer for rapid, on-site, elemental, isotopic, and molecular screening of samples is demonstrated.

The intestinal life cycle of Bacillus subtilis and close relatives.

Bacillus subtilis is considered a soil organism for which endospore formation provides a means to ensure long-term survival in the environment. We have addressed here the question of what happens to a spore when ingested. Spores displaying on their surface a heterologous antigen, tetanus toxin fragment C (TTFC), were shown to generate anti-TTFC responses not to the antigen contained in the primary oral inoculum but to those displayed on spores that had germinated and then resporulated. We then used reverse transcription-PCR to determine expression of vegetative genes and sporulation-specific genes in the mouse gut following oral dosing with spores. Significant levels of germination and sporulation were documented. Using natural isolates of B. subtilis that could form biofilms, we showed that these strains could persist in the mouse gut for significantly longer than the laboratory strain. Moreover, these isolates could grow and sporulate anaerobically and exhibited a novel phenomenon of being able to form spores in almost half the time required for the laboratory isolate. This suggests that spores are not transient passengers of the gastrointestinal tract but have adapted to carry out their entire life cycle within this environment. This is the first report showing an intestinal life cycle of B. subtilis and suggests that other Bacillus species could also be members of the gut microflora.

Carotenoids present in halotolerant Bacillus spore formers.

Six isolates of pigmented spore-forming bacteria were recovered from human faeces from subjects in Vietnam. 16S rRNA analysis demonstrated close association with known pigmented Bacillus species. All isolates were able to tolerate growth on 8% NaCl and were resistant to arsenate, characteristics that make them most related to Bacillus indicus. Two visible pigments were apparent, a yellow pigment found in vegetative cells and an orange pigment found only in spores. We used high-performance liquid chromatography to characterize and quantify these pigments and found them to be carotenoids. The biosynthetic pathway that generates them branches with one that could lead to the spore-associated orange pigmentation. Although these bacteria were found in faeces, the seafood-rich diet of Vietnam and the recovery of other pigmented Bacillus species from seafood and marine environments makes it highly probable that the true origin of these bacteria is from ingested seafood.