The benefits of dual-consultant operating in complex breast reconstruction: A retrospective cohort comparison study.

BACKGROUND: Dual-consultant operating (DCO) has been introduced in a multitude of surgical specialities. This retrospective cohort comparison study seeks to delineate any benefits DCO may confer on list utilisation, patient safety and training opportunities. METHODS: A retrospective cohort comparison of all free-flap breast reconstruction cases conducted at a single centre by five consultant plastic surgeons in the period May 2016-May 2020. RESULTS: A total of 281 patient records were used for analysis; 146 cases were dual consultants compared with 135 single consultants, representing 186 and 158 free flaps, respectively. Patient demographics were near identical in terms of patient age, BMI and ASA grade. Operating times were significantly reduced for both unilateral (mean reduction 59.49 min) and bilateral cases (mean reduction 38.14 min) with the presence of dual consultants. The mean length of stay for dual-consultant cases was on average 0.35 days less than for single consultant cases (p = 0.04). Dual-consultant case complications were less severe than those of single consultant cases (mean Clavien-Dindo severity 1.35 vs 0.96, p = 0.05). The rates of trainee one-to-one consultant training were increased in dual-consultant cases when preparing vessels (0.08 vs 0.35, p=<0.01) and performing anastomosis (0.63 vs 0.77, p = 0.03). CONCLUSIONS: DCO for complex breast reconstruction confers significant benefits to operating time, list utility and patient safety whilst protecting training opportunities for trainees. Plastic surgery departments looking to redesign services in the post-SARS-CoV-19 era should consider its adoption into their enhanced recovery protocols.

The influence of the size and symmetry of cations and anions on the physicochemical behavior of organic ionic plastic crystal electrolytes mixed with sodium salts.

The phase behaviour, ionic conductivity, electrochemical stability and diffusion coefficients of mobile components in three organic ionic plastic crystals (OIPCs): triisobutylmethylphosphonium bis(fluorosulphonyl)amide (P1i444FSI), triisobutylmethylphosphonium bis(trifluromethanesulphonyl)amide (P1i444NTf2) and trimethylisobutylphosphonium bis(trifluoromethanesulphonyl)amide (P111i4NTf2) are compared to study the effect of the anions and cations on phase behaviour and dynamics. The FSI-based OIPC shows lower melting point and higher conductivity values most likely because of the higher degree of charge distributions and weaker ion-ion interactions compared to NTf2 anion-based OIPCs. Cyclic voltammetry of electrolytes consisting of these OIPCs with 70 mol% sodium salt incorporated indicates stable sodium plating/stripping behaviour at 70 and 50 °C for all samples. The magnitude of the peak currents, however, are much higher for the FSI-based electrolyte.

Electrochemical and physicochemical properties of small phosphonium cation ionic liquid electrolytes with high lithium salt content.

Electrolytes of a room temperature ionic liquid (RTIL), trimethyl(isobutyl)phosphonium (P111i4) bis(fluorosulfonyl)imide (FSI) with a wide range of lithium bis(fluorosulfonyl)imide (LiFSI) salt concentrations (up to 3.8 mol kg(-1) of salt in the RTIL) were characterised using a combination of techniques including viscosity, conductivity, differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), nuclear magnetic resonance (NMR) and cyclic voltammetry (CV). We show that the FSI-based electrolyte containing a high salt concentration (e.g. 1 : 1 salt to IL molar ratio, equivalent to 3.2 mol kg(-1) of LiFSI) displays unusual transport behavior with respect to lithium ion mobility and promising electrochemical behavior, despite an increase in viscosity. These electrolytes could compete with the more traditionally studied nitrogen-based ionic liquids (ILs) in lithium battery applications.

Influence of Zn2+ and water on the transport properties of a pyrrolidinium dicyanamide ionic liquid.

In order to expand our understanding of a potential zinc-based battery electrolyte, we have characterized the physical and transport properties of the ionic liquid (IL) 1-butyl-1-methylpyrrolidinium dicyanamide ([C4mpyr][dca]) containing various levels of both Zn(2+) and H2O. Detailed measurements of density, viscosity, conductivity, and individual anion and cation diffusion coefficients using pulsed-field-gradient (PFG) NMR combined with NMR chemical shifts and spin-lattice relaxation (T1) NMR experiments provide insights into the motion and chemical environment of all molecular species. We find that the various techniques for probing ion transport and dynamics form a coherent picture as a function of electrolyte composition. Zn(2+) addition causes a moderate reduction in the self-diffusion of the IL anion and cation, whereas the addition of H2O increases ion mobility by increasing the liquid's overall fluidity. Temperature-dependent (13)C T1 experiments of the dca carbon analyzed using Bloembergen-Purcell-Pound fits show monotonic slowing of anion dynamics with Zn(2+) addition, suggesting increased Zn(2+)/dca(-) association. T1 experiments show minimal change in the spin-lattice relaxation of cation or anion upon H2O addition, suggesting that H2O is playing no significant role in Zn(2+) speciation. Finally, we employ a novel electrophoretic NMR technique to directly determine the electrophoretic mobility of the C4mpyr cation, which we discuss in the context of impedance-based conductivity measurements.

Atomistic simulation of structure and dynamics of the plastic crystal diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate.

Molecular dynamics simulations have been performed to investigate the interrelations between structures, transport mechanisms, and phase transitions of an organic ionic plastic crystal material, diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate ([P1,2,2,4][PF6]), in both solid and liquid phases. Examination of the temperature dependence of supercell parameters and radial distribution functions provides evidence of plastic phase transitions. Nonlinear increments of cell size within the temperature range 123-413 K are consistent with the plastic phase transitions identified from experimental analysis. The time- and temperature-dependent microstructure and dynamics have been intensively studied through analysis of trajectory files. The rotational motion and diffusion of the matrix ions are quantitatively analysed via rotational correlation functions and mean square displacements. We present new information on the evolution of molecular motions in different phases, and compare and contrast our findings with previously reported hypotheses based on nuclear magnetic resonance results. This work provides valuable information at an atomistic level to explain the experimental observations, which helps further understanding of the molecular motions underlying the plastic phase transitions.

Investigation of zoonotic infections among Auckland Zoo staff: 1991-2010.

Investigation was undertaken to assess the occurrence of zoonotic infection among staff at Auckland Zoological Park, New Zealand, in 1991, 2002 and 2010. Serial cross-sectional health surveys in 1991, 2002 and 2010 comprising a health questionnaire, and serological, immunological and microbiological analysis for a range of potential zoonotic infections were performed. Laboratory results for zoo animals were also reviewed for 2004-2010 to assess the occurrence of potential zoonotic infections. Veterinary clinic, animal handler, grounds, maintenance and administrative staff participated in the surveys, with 49, 42 and 46 participants in the 1991, 2002 and 2010 surveys, respectively (29% of total zoo staff in 2010). A small number of staff reported work-related infections, including erysipelas (1), giardiasis (1) and campylobacteriosis (1). The seroprevalence of antibodies to hepatitis A virus and Toxoplasma gondii closely reflected those in the Auckland community. No carriage of hepatitis B virus (HBV) was detected, and most of those with anti-HBV antibodies had been vaccinated. Few staff had serological evidence of past leptospiral infection. Three veterinary clinic staff had raised Chlamydophila psittaci antibodies, all < 1 : 160 indicating past exposure. Two staff (in 1991) had asymptomatic carriage of Giardia lamblia and one person (in 2010) had a dermatophyte infection. After 1991, positive tests indicating exposure to Mycobacterium tuberculosis were < 10%, comparable to the general New Zealand population. Zoo animals had infections with potential zoonotic agents, including G. lamblia, Salmonella spp., Campylobacter spp. and T. gondii, although the occurrence was low. Zoonotic agents pose an occupational risk to zoo workers. While there was evidence of some zoonotic transmission at Auckland Zoo, this was uncommon and risks appear to be adequately managed under current policies and procedures. Nevertheless, ongoing assessment of risk factors is needed as environmental, human and animal disease and management factors change. Policies and procedures should be reviewed periodically in conjunction with disease monitoring results for both animals and staff to minimise zoonotic transmission.

The effect of coordinating and non-coordinating additives on the transport properties in ionic liquid electrolytes for lithium batteries.

In the present study we expand our analysis of using two contrasting organic solvent additives (toluene and THF) in an ionic liquid (IL)/Li NTf(2) electrolyte. Multinuclear Pulsed-Field Gradient (PFG) NMR, spin-lattice (T(1)) relaxation times and conductivity measurements over a wide temperature range are discussed in terms of transport properties and structuring of the liquid. The conductivity of both additive samples is enhanced the most at low temperatures, with THF slightly more effective than toluene. Both the anion and lithium self-diffusivity are enhanced in the same order by the additives (THF > toluene) while that of the pyrrolidinium cation is marginally enhanced. (1)H spin-lattice relaxation times indicate a reasonable degree of structuring and anisotropic motion within all of the samples and both (19)F and (7)Li highlight the effectiveness of THF at influencing the lithium coordination within these systems.

Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xH(x-1)]-.

We describe a fluidity and conductivity study as a function of composition in N-methylpyrrolidine-acetic acid mixtures. The simple 1 : 1 acid-base mixture appears to form an ionic liquid, but its degree of ionicity is quite low and such liquids are better thought of as poorly dissociated mixtures of acid and base. The composition consisting of 3 moles acetic acid and 1 mole N-methylpyrrolidine is shown to form the highest ionicity mixture in this binary due to the presence of oligomeric anionic species [(AcO)(x)H(x-1)](-) stabilised by hydrogen bonds. These oligomeric species, being weaker bases than the acetate anion, shift the proton transfer equilibrium towards formation of ionic species, thus generating a higher degree of ionicity than is present at the 1 : 1 composition. A Walden plot analysis, thermogravimetric behaviour and proton NMR data, as well as ab initio calculations of the oligomeric species, all support this conclusion.

The 2000 canine distemper epidemic in Caspian seals (Phoca caspica): pathology and analysis of contributory factors.

More than 10,000 Caspian seals (Phoca caspica) were reported dead in the Caspian Sea during spring and summer 2000. We performed necropsies and extensive laboratory analyses on 18 seals, as well as examination of the pattern of strandings and variation in weather in recent years, to identify the cause of mortality and potential contributory factors. The monthly stranding rate in 2000 was up to 2.8 times the historic mean. It was preceded by an unusually mild winter, as observed before in mass mortality events of pinnipeds. The primary diagnosis in 11 of 13 seals was canine distemper, characterized by broncho-interstitial pneumonia, lymphocytic necrosis and depletion in lymphoid organs, and the presence of typical intracytoplasmic inclusion bodies in multiple epithelia. Canine distemper virus infection was confirmed by phylogenetic analysis of reverse transcriptase-polymerase chain reaction products. Organochlorine and zinc concentrations in tissues of seals with canine distemper were comparable to those of Caspian seals in previous years. Concurrent bacterial infections that may have contributed to the mortality of the seals included Bordetella bronchiseptica (4/8 seals), Streptococcus phocae (3/8), Salmonella dublin (1/8), and S. choleraesuis (1/8). A newly identified bacterium, Corynebacterium caspium, was associated with balanoposthitis in one seal. Several infectious and parasitic organisms, including poxvirus, Atopobacter phocae, Eimeria- and Sarcocystis-like organisms, and Halarachne sp. were identified in Caspian seals for the first time.

Differentiating infection from vaccination in foot-and-mouth-disease: evaluation of an ELISA based on recombinant 3ABC.

Recent devastating outbreaks of foot-and-mouth disease (FMD) in Europe have reopened the discussion about the adequacy of the non-vaccination strategy implemented by the EU in 1991. Here we describe the evaluation of a new commercially available test kit for the discrimination between vaccination and infection. The test is based on the detection of antibodies against the recombinant non-structural (NS) protein 3ABC. In contrast to immunization with vaccines free of 3ABC, these antibodies are elicited as a consequence of infection. Testing more than 3600 negative sera from several countries revealed a specificity of > 99% for bovine, ovine, and porcine samples. Antibodies specific for 3ABC can be detected as soon as 10 days post-infection. As compared with the occurrence of antibodies against structural proteins of FMDV, anti-3ABC antibodies can be detected 5-10 days later, depending on the species. No anti-3ABC antibodies were detected in sera from vaccination experiments or in field sera from vaccinated animals. However, anti-3ABC antibodies can be detected in vaccinated animals upon challenge. These results provide evidence that this test can facilitate the use of vaccines in new strategies against FMD.

Development of reverse transcription-PCR (oligonucleotide probing) enzyme-linked immunosorbent assays for diagnosis and preliminary typing of foot-and-mouth disease: a new system using simple and aqueous-phase hybridization.

A reverse transcription-PCR (RT-PCR)-enzyme-linked immunosorbent assay system that detects a relatively conserved region within the RNA genome of all seven serotypes of foot-and-mouth disease virus (FMDV) has been developed. The high specificity of the assay is achieved by including a rapid hybridization step with a biotin-labeled internal oligonucleotide. The assay is highly sensitive, fast, and easy to perform. A similar assay, based on a highly variable region of the FMDV genome and employing a single asymmetric RT-PCR and multiple hybridization oligonucleotides, was developed to demonstrate the method's ability to type FMDV. Based on our theoretical and practical knowledge of the methodology, we predict that similar assays are applicable to diagnosis and strain differentiation in any system amenable to PCR amplification.

Mass die-Off of Caspian seals caused by canine distemper virus.

Thousands of Caspian seals (Phoca caspica) died in the Caspian Sea from April to August 2000. Lesions characteristic of morbillivirus infection were found in tissue specimens from dead seals. Canine distemper virus infection was identified by serologic examination, reverse transcriptase- polymerase chain reaction, and sequencing of selected P gene fragments. These results implicate canine distemper virus infection as the primary cause of death.

Photosensitization of pancreatic tumour cells by delta-aminolaevulinic acid esters.

A series of straight chain, branched and cyclo-delta-aminolaevulinic acid (ALA) esters have been synthesized and their photosensitizing properties analysed using an in vitro system of rat pancreatoma cells. Structurally favourable ALA esters not only induced the formation of more of the endogenous photosensitizer, protoporphyrin IX (PpIX), but they did so at a faster rate than ALA itself. This action was reflected in a substantial increase in photocytotoxicity of some 270 times, using the more potent ALA esters. An important structural feature was identified in two of the ALA esters which greatly limited PpIX production, i.e. a branch point located next to the site of ester cleavage. Experiments on the transport of ALA and of ALA esters across the cell membrane showed that ALA, but not ALA esters, gain access to the cell via the di- and tripeptide transporter, PEPTI. Finally, these results show that the esterification of ALA can greatly increase its cellular uptake, so generating more intracellular PpIX, improved tumour cell photosensitization and enhanced photocytotoxicity.

Intercellular communication in Helicobacter pylori: luxS is essential for the production of an extracellular signaling molecule.

Individual bacteria of numerous species can communicate and coordinate their actions via the production, release, and detection of extracellular signaling molecules. In this study, we used the Vibrio harveyi luminescence bioassay to determine whether Helicobacter pylori produces such a factor. Cell-free conditioned media from H. pylori strains 60190 and 26695 each induced >100-fold-greater luminescence in V. harveyi than did sterile culture medium. The H. pylori signaling molecule had a molecular mass of <10 kDa, and its activity was unaffected by heating to 80 degrees C for 5 min or protease treatment. The genome sequence of H. pylori 26695 does not contain any gene predicted to encode an acyl homoserine lactone synthase but does contain an orthologue of luxS, which is required for production of autoinducer-2 (AI-2) in V. harveyi. To evaluate the role of luxS in H. pylori, we constructed luxS null mutants derived from H. pylori 60190 and 26695. Conditioned media from the wild-type H. pylori strains induced >100-fold-greater luminescence in the V. harveyi bioassay than did conditioned medium from either mutant strain. Production of the signaling molecule was restored in an H. pylori luxS null mutant strain by complementation with a single intact copy of luxS placed in a heterologous site on the chromosome. In addition, Escherichia coli DH5alpha produced autoinducer activity following the introduction of an intact copy of luxS from H. pylori. Production of the signaling molecule by H. pylori was growth phase dependent, with maximal production occurring in the mid-exponential phase of growth. Transcription of H. pylori vacA also was growth phase dependent, but this phenomenon was not dependent on luxS activity. These data indicate that H. pylori produces an extracellular signaling molecule related to AI-2 from V. harveyi. We speculate that this signaling molecule may play a role in regulating H. pylori gene expression.

Localization of foot-and-mouth disease virus RNA by in situ hybridization within bovine tissues.

Foot-and-mouth disease is a highly contagious disease of cloven hooved animals. In cattle, both acute and long-term persistent infections occur. Foot-and-mouth disease virus (FMDV), a picornavirus, has been shown, using virus isolation procedures, to replicate in the pharynx and soft palate of cattle. In this study, in situ hybridization has been used to detect FMDV RNA within the cells of tissues removed from infected bovines. A digoxigenin-labelled anti-sense RNA probe was prepared corresponding to a region of the FMDV genome encoding part of the RNA-dependent RNA polymerase (3D). The efficacy and specificity of this probe for in situ hybridisation was determined using virus-infected cells in tissue culture. Strong cytoplasmic staining was only detected in FMDV-infected cells. Various tissue samples were collected from FMDV-infected cattle between 5 and 17 days post-infection. Viral RNA was detected by in situ hybridisation within cells of the soft palate, tonsil and pharynx up to 17 days post-infection. This technique is useful for the study of FMDV localization in cattle both during and after the acute clinical phase of disease and may assist in identifying specific sites of virus persistence.

Mutational analysis of the vacA promoter provides insight into gene transcription in Helicobacter pylori.

Analysis of 12 Helicobacter pylori promoters indicates the existence of a consensus -10 hexamer (TAtaaT) but little conservation of -35 sequences. In this study, mutations in either the H. pylori vacA -10 region or the -35 region resulted in decreased vacA transcription and suggested that an extended -10 motif is utilized. Thus, despite the lack of a -35 consensus sequence for H. pylori promoters, the -35 region plays a functional role in vacA transcription.

Helicobacter pylori strain-specific genotypes and modulation of the gastric epithelial cell cycle.

Helicobacter pylori cag+ strains enhance gastric epithelial cell proliferation and attenuate apoptosis in vivo, which may partially explain the increased risk of gastric cancer associated with these strains. The goals of this study were to identify specific H. pylori genes that regulate epithelial cell cycle events and determine whether these effects were dependent upon p53-mediated pathways. AGS gastric epithelial cells were cultured alone or in the presence of 21 clinical H. pylori isolates, H. pylori reference strain 60190, or its isogenic cagA-, picB-, vacA-, or picB-/vacA- derivatives. Coculture of H. pylori with AGS cells significantly decreased cell viability, an effect most prominent with cag+ strains (P < 0.001 versus cag-strains). cag+ strains significantly increased progression of AGS cells from G1 into G2-M at 6 h and enhanced apoptosis by 72 h. Compared with the parental 60190 strain, the picB- mutant attenuated cell cycle progression at 6 h (P < or = 0.05), and decreased apoptosis with enhanced AGS cell viability at 24 h (P < or = 0.04). The vacA- mutant decreased apoptosis and enhanced viability at later (48-72 h) time points (P < or = 0.05). Compared with the wild-type strain, the picB-/vacA- double mutant markedly attenuated apoptosis and increased cell viability at all time points (P < or = 0.05). Furthermore, cocolonization with H. pylori had no significant effect on expression of p53, p21, and MDM2. The diminished AGS cell viability, progression to G2-M, and apoptosis associated with cag+ H. pylori strains were dependent upon expression of vacA and genes within the cag pathogenicity island. These results may explain heterogeneity in levels of gastric epithelial cell proliferation and apoptosis found within H. pyloricolonized mucosa.

Molecular and biochemical analysis of a 105 kDa Mycoplasma gallisepticum cytadhesin (GapA).

The identification of a gene (gapA) from Mycoplasma gallisepticum with homology to the P1 cytadherence gene of Mycoplasma pneumoniae is reported. The gapA gene is a 2895 bp ORF encoding a protein with a molecular mass of 105 kDa. Nucleotide sequence analysis of the gapA gene revealed 45% homology to the M. pneumoniae P1 gene, 46% homology to the Mycoplasma genitalium MgPa gene and 47% homology to the Mycoplasma pirum P1-like protein gene. It has a 64 mol % A+T content compared to 46, 60 and 72 mol % respectively for the P1, MgPa and the P1-like protein genes. As with the P1 and MgPa genes, gapA is a central gene in a multi-gene operon, but unlike the P1 and MgPa genes, there is only a single copy of gapA in the genome. GapA is a trypsin-sensitive surface-exposed protein. Chicken tracheal-ring inhibition-of-attachment assays, using anti-GapA Fab fragments, resulted in 64% inhibition of attachment. These results indicated that GapA plays a role in cytadherence of M. gallisepticum to host cells.

Antibody to the nonstructural proteins of foot-and-mouth disease virus in vaccinated animals exposed to infection.

Cattle which have been infected with foot-and-mouth disease (FMD) virus can be differentiated from those that have been vaccinated on the basis of the detection of antibody to one or more of the non-structural (NS) proteins of the virus. Cattle which have been protected by vaccination can become persistently infected with FMD virus (FMDV) without ever showing clinical signs. Vaccinated, protected cattle which are persistently infected cannot be distinguished from animals that merely have been vaccinated on the basis of serological tests for antibody to the structural proteins of FMDV. Sera were collected from groups of cattle for varying periods after exposure to infection under experimental conditions. On the basis of isolation of virus from probang samples collected during the course of the experiments it was possible to classify the cattle according to the following criteria; naive, infected and eliminated the virus (convalescent), infected and persistently infected with FMDV (carriers), vaccinated alone, vaccinated and either convalescent or carrier. Sera were examined for antibody to the NS proteins Lb, 2C, 3A, 3D, and 3ABC by an indirect profiling ELISA using E. coli-expressed fusion proteins as antigens. Considerable variation was observed in the antibody response to NS proteins of both naive and vaccinated animals following infection. The extent of individual variation was so great that convalescent animals could not be differentiated from carrier animals on the basis of their antibody response to any of the NS proteins examined. The majority of vaccinated, protected animals showed an antibody response to NS proteins, particularly 3ABC, following exposure to infection. However, the carrier state was demonstrated in some vaccinated, protected animals in which no antibody response to any of the NS proteins could be detected. The detection of antibody to NS proteins can therefore be used on a group, or herd, basis to detect circulation of virus in a vaccinated population but further investigations in the field are required to determine the sampling level necessary for statistical acceptance. On an individual animal basis, however, freedom from antibody to NS proteins in a vaccinated animal, or an animal of unknown history, does not necessarily imply that the animal is free from infection with FMD virus and, furthermore, the titre of antibody to NS proteins is not a useful predictive measure of whether or not an infected animal has successfully eliminated the virus.