AAGBI: Safer pre-hospital anaesthesia 2017: Association of Anaesthetists of Great Britain and Ireland.

Pre-hospital emergency anaesthesia with oral tracheal intubation is the technique of choice for trauma patients who cannot maintain their airway or achieve adequate ventilation. It should be carried out as soon as safely possible, and performed to the same standards as in-hospital emergency anaesthesia. It should only be conducted within organisations with comprehensive clinical governance arrangements. Techniques should be straightforward, reproducible, as simple as possible and supported by the use of checklists. Monitoring and equipment should meet in-hospital anaesthesia standards. Practitioners need to be competent in the provision of in-hospital emergency anaesthesia and have supervised pre-hospital experience before carrying out pre-hospital emergency anaesthesia. Training programmes allowing the safe delivery of pre-hospital emergency anaesthesia by non-physicians do not currently exist in the UK. Where pre-hospital emergency anaesthesia skills are not available, oxygenation and ventilation should be maintained with the use of second-generation supraglottic airways in patients without airway reflexes, or basic airway manoeuvres and basic airway adjuncts in patients with intact airway reflexes.

Mutant frizzled-4 disrupts retinal angiogenesis in familial exudative vitreoretinopathy.

Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. Loci associated with FEVR map to 11q13-q23 (EVR1; OMIM 133780, ref. 1), Xp11.4 (EVR2; OMIM 305390, ref. 2) and 11p13-12 (EVR3; OMIM 605750, ref. 3). Here we have confirmed linkage to the 11q13-23 locus for autosomal dominant FEVR in one large multigenerational family and refined the disease locus to a genomic region spanning 1.55 Mb. Mutations in FZD4, encoding the putative Wnt receptor frizzled-4, segregated completely with affected individuals in the family and were detected in affected individuals from an additional unrelated family, but not in normal controls. FZD genes encode Wnt receptors, which are implicated in development and carcinogenesis. Injection of wildtype and mutated FZD4 into Xenopus laevis embryos revealed that wildtype, but not mutant, frizzled-4 activated calcium/calmodulin-dependent protein kinase II (CAMKII) and protein kinase C (PKC), components of the Wnt/Ca(2+) signaling pathway. In one of the mutants, altered subcellular trafficking led to defective signaling. These findings support a function for frizzled-4 in retinal angiogenesis and establish the first association between a Wnt receptor and human disease.

Optimal sampling locations to reduce uncertainty in contamination extent in water distribution systems.

Drinking water utilities rely on samples collected from the distribution system to provide assurance of water quality. If a water contamination incident is suspected, samples can be used to determine the source and extent of contamination. By determining the extent of contamination, the percentage of the population exposed to contamination, or areas of the system unaffected can be identified. Using water distribution system models for this purpose poses a challenge because significant uncertainty exists in the contamination scenarios (e.g., injection location, amount, duration, customer demands, contaminant characteristics). This article outlines an optimization framework to identify strategic sampling locations in water distribution systems. The framework seeks to identify the best sampling locations to quickly determine the extent of the contamination while considering uncertainty with respect to the contamination scenarios. The optimization formulations presented here solve for multiple optimal sampling locations simultaneously and efficiently, even for large systems with a large uncertainty space. These features are demonstrated in two case studies.

Dapper, a Dishevelled-associated antagonist of beta-catenin and JNK signaling, is required for notochord formation.

Dapper was isolated in a screen for proteins interacting with Dishevelled, a key factor in Wnt signaling. Dapper and Dishevelled colocalize intracellularly and form a complex with Axin, GSK-3, CKI, and beta-catenin. Overexpression of Dapper increases Axin and GSK-3 in this complex, resulting in decreased soluble beta-catenin and decreased activation of beta-catenin-responsive genes. Dapper also inhibits activation by Dishevelled of c-Jun N-terminal kinase (JNK), a component of beta-catenin-independent Frizzled signaling. Inhibition of Dapper activates both beta-catenin-responsive genes and an AP1-responsive promoter, demonstrating that Dapper is a general Dishevelled antagonist. Depletion of maternal Dapper RNA from Xenopus embryos results in loss of notochord and head structures, demonstrating that Dapper is required for normal vertebrate development.

Dishevelled activates Ca2+ flux, PKC, and CamKII in vertebrate embryos.

Wnt ligands and Frizzled (Fz) receptors have been shown to activate multiple intracellular signaling pathways. Activation of the Wnt-beta-catenin pathway has been described in greatest detail, but it has been reported that Wnts and Fzs also activate vertebrate planar cell polarity (PCP) and Wnt-Ca2+ pathways. Although the intracellular protein Dishevelled (Dsh) plays a dual role in both the Wnt-beta-catenin and the PCP pathways, its potential involvement in the Wnt-Ca2+ pathway has not been investigated. Here we show that a Dsh deletion construct, XDshDeltaDIX, which is sufficient for activation of the PCP pathway, is also sufficient for activation of three effectors of the Wnt-Ca2+ pathway: Ca2+ flux, PKC, and calcium/calmodulin-dependent protein kinase II (CamKII). Furthermore, we find that interfering with endogenous Dsh function reduces the activation of PKC by Xfz7 and interferes with normal heart development. These data suggest that the Wnt-Ca2+ pathway utilizes Dsh, thereby implicating Dsh as a component of all reported Fz signaling pathways.

Transcription of nonrepeated DNA in mouse brain.

Under normal conditions of DNA renaturation, about 60 percent of mouse DNA fragments renature at a rate consistent with their being present only once per sperm. These nonrepeated sequences (also called single-copy or unique) may be used in RNA-DNA hybridization experiments to provide quantitative estimates of RNA diversity. About 10 percent of the mouse single-copy sequences are transcribed in mouse brain tissue. Estimates of about 3 percent were obtained for mouse liver and kidney RNA's. If only one of the complementary DNA strands is transcribed, this hybridization value implies that the equivalent of at least 300,000 different sequences of 1000 nucleotides are expressed in mouse brain tissue. It is suggested that the large amount of DNA in mammals is functionally important, and that a substantial proportion of the genome is expressed in the brain.

A survey of surgical airway experiences and equipment among immediate care doctors.

BACKGROUND: There is a variety of approaches to obtaining a surgical airway, but little literature on techniques other than surgical cricothyroidotomy and the placement of a cuffed tube. METHODS: An e-mail and postal survey of the memberships of the British Association for Immediate Care (BASICS) and BASICS (Scotland) was performed to ascertain the equipment carried for a surgical airway and obtain summarised case reports of the surgical airways performed. RESULTS: The response rate was 359 of 942 surveys sent (38%). Most doctors carry equipment to perform a surgical airway. A total of 93 prehospital surgical airways was reported as summarised cases. A needle cricothyroidotomy was initially obtained in 17 cases (18%) but was changed to other types in all but six cases. Of these six patients, two survived to hospital. A small uncuffed tube was initially placed in 29 patients (31%) and remained in 23 cases; 22 survived to hospital. A surgical cricothyroidotomy and placement of a cuffed tube was the initial airway obtained in 51 cases and the final airway obtained in 64 (69%) patients; 34 survived to reach hospital. Some spontaneous ventilation remained in 56 (60%) patients. CONCLUSIONS: This paper reports the successful prehospital use of small uncuffed tubes in both breathing and apnoeic patients. The survival rate to hospital following a prehospital surgical airway is reasonable. There is a high incidence of spontaneous ventilation in this patient cohort. There were a number of limitations with this study, but the subject is worthy of further research.

Fragile-X syndrome and myotonic dystrophy: parallels and paradoxes.

Fragile-X syndrome and myotonic dystrophy are caused by triplet repeat expansions embedded in CpG islands in the transcribed non-coding regions of the FMR1 and the DMPK genes, respectively. Although initial reports emphasized differences in the mechanisms by which the expanded triplet repeats caused these diseases, results published in the past year highlight remarkable parallels in the likely molecular etiologies. At both loci, expansion is associated with altered chromatin, aberrant methylation, and suppressed expression of the adjacent FMR1 and DMAHP genes, implicating epigenetic mediation of these genetic diseases.

Proposed genetic basis of Huntington's disease.

I propose that Huntington's disease (HD) is caused by dominant position-effect variegation, a phenomenon for which new information is available in Drosophila melanogaster. The essential features of this proposal are that (1) the HD mutation is the result of a chromosome alteration that inactivates transcription of a nearby structural gene or genes (cis-inactivation); the combination of this proposed chromosome alteration and the structural gene(s) is termed the HD allele; (2) there is pairing in some somatic cells between the HD and HD+ alleles on homologous chromosomes; (3) as a result of this somatic pairing, the HD mutation also inactivates transcription of the HD+ structural gene on the normal homologue (trans-inactivation), resulting in complete dominance of the mutation; (4) polymorphism for an X-linked recessive modifier of position-effect variegation means that the age of onset of symptoms of HD will depend on which parent the HD mutation was inherited from. The fully dominant nature of HD and the parental-source effect on the age of onset are thus both understandable within the genetic and epigenetic paradigm of position-effect variegation.

Farmers' beliefs about bovine tuberculosis control in Northern Ireland.

Beliefs can play an important role in farmer behaviour and willingness to adopt new policies. In Northern Ireland, bovine tuberculosis (bTB) is one of the most important endemic diseases facing the cattle industry. An observational study was conducted on 192 farms in a high bTB incidence area during 2010-2011 in order to obtain a better understanding of farmers' beliefs in relation to bTB control. The views of farmers who had experienced a recent confirmed or multiple reactor bTB breakdowns (cases) were compared to those of farmers who had no recent reactors or restricted herd tests (controls). Data were obtained from a face-to-face questionnaire assessing farmers' agreement to 22 statements. All participating farmers found bTB control important and most were keen to learn more about bTB biosecurity measures and were in favour of the cattle-related bTB control measures as presented in the questionnaire (isolation of skin test inconclusive animals, use of the gamma-interferon test and pre-movement testing). The majority of farmers would allow badger vaccination and culling on their own land with an overall preference for vaccination. Highest disagreement was shown for the statements querying a willingness to pay for bTB control measures. There was agreement on most issues between case and control farmers and between different age groups of farmers although case farmers showed more support for additional advice on bTB biosecurity measures (P = 0.042). Case farmers were also more in favour of allowing badger vaccination (P = 0.008) and culling (P = 0.043) on their land and showed less concern for public opposition (P = 0.048).

Herd-level risk factors for bovine tuberculosis and adoption of related biosecurity measures in Northern Ireland: A case-control study.

Bovine tuberculosis (bTB) is a zoonotic disease which is endemic in Northern Ireland. As it has proven difficult to eradicate this disease, partly due to a wildlife reservoir being present in the European badger (Meles meles), a case-control study was conducted in a high incidence area in 2010-2011. The aim was to identify risk factors for bTB breakdown relating to cattle and badgers, and to assess the adoption of bTB related biosecurity measures on farms. Face-to-face questionnaires with farmers and surveys of badger setts and farm boundaries were conducted on 117 farms with a recent bTB breakdown (cases) and 75 farms without a recent breakdown (controls). On logistic regression at univariable and multivariable levels, significant risk factors associated with being a case herd included having an accessible badger sett within the farm boundaries in a field grazed in the last year (odds ratio, OR, 4.14; 95% confidence interval, CI, 1.79, 9.55), observation of live badgers (OR 4.14; 95% CI 1.79, 9.55), purchase of beef cattle (OR 4.60; 95% CI 1.61, 13.13), use of contractors to spread slurry (OR 2.83; 95% CI 1.24, 6.49), feeding meal on top of silage (OR 3.55; 95% CI 1.53, 8.23) and feeding magnesium supplement (OR = 3.77; 95% CI 1.39, 10.17). The majority of setts within the farm boundary were stated to be accessible by cattle (77.1%; 95% CI 71.2, 83.0%) and 66.8% (95% CI 63.8, 69.7%) of farm boundaries provided opportunities for nose-to-nose contact between cattle. Adoption of bTB related biosecurity measures, especially with regards to purchasing cattle and badger-related measures, was lower than measures related to disinfection and washing.

Proposed mechanism of inheritance and expression of the human fragile-X syndrome of mental retardation.

A mechanism is proposed for the inheritance and expression of the fragile-X-linked syndrome of mental retardation in humans. Two independent events are required for expression of the syndrome: the fragile-X mutation, and X chromosome inactivation in pre-oogonial cells. The fragile-X mutation at site Xq27 has little or no effect until the chromosome is inactivated in a female as part of the process of dosage compensation. At a stage where the inactivated X chromosome would normally be reactivated in preparation for oogenesis, the mutation results in a local block to the reactivation process. This block to reactivation leads to mental retardation in progeny by reducing the level of products from the unreactivated Xq27 region in male cells, and, for a heterozygous female, in somatic cells in which the normal X chromosome has been inactivated. Published data relevant to this proposed mechanism are discussed.

Sandwich ELISA detection of Clostridium perfringens cells and alpha-toxin from field cases of necrotic enteritis of poultry.

Sandwich ELISAs (sELISAs) for the detection of Clostridium perfringens cells and alpha-toxin were developed and used to screen intestinal samples from normal broiler chickens and from clinical cases of necrotic enteritis. The assays clearly distinguished between the two sets of samples. The sELISA absorbance values from samples obtained from the majority of healthy birds were low and those from the majority of necrotic enteritis cases were high. Together, the assays provide a suitable test for the rapid screening for the diagnosis of necrotic enteritis in poultry.

Discrepancy between first-dose converting enzyme inhibition at rest and subsequent inhibition during exercise in chronic heart failure.

Low-dose angiotensin-converting enzyme inhibition is thought to completely block the renin-angiotensin system. This study examined the hemodynamic and hormonal responses to initial low- and higher dose converting-enzyme inhibitor (lisinopril or captopril) at rest compared with the response during subsequent chronic therapy while treadmill exercise testing was performed in nine patients with chronic heart failure. At rest, similar changes in systemic arterial pressure, plasma renin activity, and plasma aldosterone concentration were found with initial low and higher doses. However, after at least 4 weeks of therapy, dose-dependent increases in plasma renin activity and decreases in plasma aldosterone concentration were noted during exercise without significant differences in exercise systemic arterial pressure or heart rate. This discrepancy suggests that initial low-dose converting enzyme inhibition does completely block the enzyme, but higher dose therapy is required for complete blockade during subsequent exercise in chronic heart failure.

Combined blood cell counting and classification with fluorochrome stains and flow instrumentation.

A multiparameter flow cytophotometer was used to count and classify fixed human blood cells fluorochromed with a mixture of ethidium bromide (EB), brilliant sulfaflavine and a blue fluorescent stilbene disulfonic acid derivative (LN). The system measures light scattered by the cells and absorption at 420 nm for all cells. In addition, nuclear EB fluorescence (540 leads to 610 nm) and cytoplasmic fluorescence from LN (366 leads to 470 nm), brilliant sulfaflavine (420 leads to 520 nm) and EB exicted by energy transfer from LN (366 leads to 610 nm) are measured for all nucleated cells. This information is sufficient to perform red and white blood cell counts and to classify leukocytes as lymphocytes, monocytes, basophils, eosinophils or neutrophils. Light scattering and/or nuclear and cytoplasmic fluorescence values may be further analyzed to obtain the ratio of immature to mature neutrophils. Counts produced by the system are in reasonable agreement with those obtained by electronic cells counting and examination of Wright's-stained blood smears; some discrepancies appear to be due to systematic errors in the manual counting method.

Fragile-X mutation proposed to block complete reactivation in females of an inactive X chromosome.

I discuss two aspects of my proposal that fra(X) chromosomes exist in two states, imprinted and non-imprinted: why do males not imprint the fra(X); does the "Sherman paradox" rule out my proposal?

Possible erasure of the imprint on a fragile X chromosome when transmitted by a male.

Although most males with the fragile-X [fra(X)] syndrome do not reproduce, there are 2 published pedigrees that include affected males who have daughters and who thus appear to have transmitted the fragile-X chromosome to their progeny. In addition, one published fra(X) pedigree includes an apparently normal male who expresses cytogenetically the fra(X) site at high frequency and who has 3 daughters. In the 6 daughters of these 3 males, there is little or no cytogenetic expression of the fra(X). I interpret these pedigrees within the context of my X-inactivation imprinting model of the fra(X) syndrome (Genetics 117:587-599): the cytogenetic manifestation of the imprinted state of the mutant fra(X) chromosome [high percentage of cytogenetic expression] is no longer present in daughters of imprinted males. I propose that the imprinted state is erased when an imprinted fragile-X chromosome is passed through a male. Such erasure in the gender opposite to the gender that established the imprint is in accord with other examples of chromosome imprinting in mammals. Additional data from unpublished fra(X) pedigrees are requested.

Intercalary heterochromatin of Drosophila as a potential model for human fragile sites.

We summarize our proposal that "intercalary heterochromatin" of Drosophila is a useful model for human fragile sites. Comparison with Drosophila site 11A suggests that the normal allele of fragile site Xq27 is a meiotic pairing site.

The dissociation constants of alizarin fluorine blue.

Dissociation constants for the analytical reagent alizarin fluorine blue (3-aminomethylalizarin-N N-diacetic acid) have been determined by potentiometric titration at ionic strength 0.1, and are k(1) = 1.28 +/- 0.30 x 10(-5); k(2) = 2.82 +/- 0.24 x 10(-8); k(3) = 3.72 +/- 0.19 x 10(-11); k(4) = 6.39 +/- 0.12 x 10(-12).