E-cigarette constituents propylene glycol and vegetable glycerin decrease glucose uptake and its metabolism in airway epithelial cells in vitro.

Electronic nicotine delivery systems, or e-cigarettes, utilize a liquid solution that normally contains propylene glycol (PG) and vegetable glycerin (VG) to generate vapor and act as a carrier for nicotine and flavorings. Evidence indicated these "carriers" reduced growth and survival of epithelial cells including those of the airway. We hypothesized that 3% PG or PG mixed with VG (3% PG/VG, 55:45) inhibited glucose uptake in human airway epithelial cells as a first step to reducing airway cell survival. Exposure of H441 or human bronchiolar epithelial cells (HBECs) to PG and PG/VG (30-60 min) inhibited glucose uptake and mitochondrial ATP synthesis. PG/VG inhibited glycolysis. PG/VG and mannitol reduced cell volume and height of air-liquid interface cultures. Mannitol, but not PG/VG, increased phosphorylation of p38 MAPK. PG/VG reduced transepithelial electrical resistance, which was associated with increased transepithelial solute permeability. PG/VG decreased fluorescence recovery after photobleaching of green fluorescent protein-linked glucose transporters GLUT1 and GLUT10, indicating that glucose transport function was compromised. Puffing PG/VG vapor onto the apical surface of primary HBECs for 10 min to mimic the effect of e-cigarette smoking also reduced glucose transport. In conclusion, short-term exposure to PG/VG, key components of e-cigarettes, decreased glucose transport and metabolism in airway cells. We propose that this was a result of PG/VG reduced cell volume and membrane fluidity, with further consequences on epithelial barrier function. Taking these results together, we suggest these factors contribute to reduced defensive properties of the epithelium. We propose that repeated/chronic exposure to these agents are likely to contribute to airway damage in e-cigarette users.

Essential oils inhibit the bovine respiratory pathogens Mannheimia haemolytica, Pasteurella multocida and Histophilus somni and have limited effects on commensal bacteria and turbinate cells in vitro.

AIMS: The objective of this study was to determine antimicrobial activities of essential oils (EOs) against bovine respiratory disease (BRD) pathogens and nasopharyngeal commensal bacteria, as well as cytotoxicity in bovine turbinate (BT) cells in vitro. METHODS AND RESULTS: The chemical composition of 16 EOs was determined using gas chromatography-mass spectrometry. All EOs were first evaluated for growth inhibition of a single BRD pathogen Mannheimia haemolytica serotype 1 strain (L024A). The most inhibitory EOs (n = 6) were then tested for antimicrobial activity against multidrug-resistant strains of M. haemolytica (serotypes 1, 2 and 6); the BRD pathogens Pasteurella multocida and Histophilus somni, as well as commensal bacteria that were isolated from the nasopharynx of feedlot cattle. The cytotoxicity of 10 EOs was also evaluated using a BT cell line. The EOs ajowan, thyme and fennel most effectively inhibited all BRD pathogens tested including multidrug-resistant strains with minimum inhibitory concentrations (MIC) of ≤0·025% (volume/volume, v/v). For these EOs, the MIC was 2-32 fold greater against commensal bacteria, compared to BRD-associated pathogens. No cytotoxic effects of EOs against BT cells were observed within the tested range of concentrations (0·0125-0·4%, v/v). CONCLUSIONS: The EOs ajowan, thyme and fennel inhibited M. haemolytica, P. multocida and H. somni at a concentration of 0·025% and had minimal antimicrobial activity against nasopharyngeal commensal bacteria and cytotoxicity against BT cells. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated that EOs may have potential for intra-nasal administration to mitigate bovine respiratory pathogens in feedlot cattle.

Sheep tick Ixodes ricinus management on Welsh hill farms of designated conservation importance: implications for nationally declining birds.

Impacts of sheep ticks Ixodes ricinus on livestock, gamebirds and wildlife are of concern across Europe. The present study describes livestock and tick management by 36 farmers from three upland sites of conservation importance in North Wales, where farmers consider that ticks have increased during the last 25 years. Sheep, average densities of 2.0 animals per ha were treated with pour-on acaricides in spring, again in July, and also when removed from the moor in autumn. Given acaricide efficacy rates, sheep were susceptible to tick bites for half the period on the moor. Sheep from 17 farms were examined for ticks. Infestations were similar between farms and in relation to the acaricide used, averaging 9.3 ticks per sheep, although they were lower where the interval between successive acaricide treatments was shorter. Repeated sampling of sheep and red grouse chicks showed no annual difference in tick burdens on grouse chicks, which averaged 6.2 ticks per chick, although there were three-fold fewer ticks on sheep in 2018 than in previous years. Tick bite rates on sheep and grouse were higher than elsewhere in the U.K. Most farmers interviewed would aim to improve their tick management using longer-lasting acaricides and treating sheep more frequently, although they would need advice and financial help, which is currently unavailable via Government funded agri-environment schemes.

The effects of acaricide treatment of sheep on red grouse Lagopus lagopus scotica tick burdens and productivity in a multi-host system.

Ixodes ricinus (Ixodida: Ixodidae) ticks are of economic and pathogenic importance across Europe. Within the uplands of the U.K., management to reduce ticks is undertaken to benefit red grouse Lagopus lagopus scotica (Galliformes: Phasianidae). Management strategies focus on the acaricide treatment of domestic sheep Ovis aries (Artiodactyla: Bovidae), but the effectiveness of this is less certain in the presence of wild hosts, particularly red deer Cervus elaphus (Artiodactyla: Cervidae) and mountain hare Lepus timidus (Lagomorpha: Leporidae). This study examines the effects of sheep management on grouse tick burdens and productivity using sites with a range of wild host densities. Sites at which applications of acaricide were more frequent had lower tick burdens; this relationship was similar on sites with a range of deer densities. However, no direct link was detected between acaricide treatment interval and grouse productivity. Sites with higher deer densities had higher grouse tick burdens and lower productivity [mean ± standard error (SE) young : adult ratio: 1.2 ± 0.2] compared with sites with lower deer densities (mean ± SE young : adult ratio: 1.8 ± 0.1). Sites with higher grouse brood sizes and higher proportions of hens with broods were also those with higher mountain hare abundance indices. This study highlights the importance of the frequent treatment of sheep with acaricide to reduce tick burdens on grouse, even in the presence of wild hosts.

Conceptualising production, productivity and technology in pharmacy practice: a novel framework for policy, education and research.

CONTEXT AND BACKGROUND: People and health systems worldwide face serious challenges due to shifting disease demographics, rising population demands and weaknesses in healthcare provision, including capacity shortages and lack of impact of healthcare services. These multiple challenges, linked with the global push to achieve universal health coverage, have made apparent the importance of investing in workforce development to improve population health and economic well-being. In relation to medicines, health systems face challenges in terms of access to needed medicines, optimising medicines use and reducing risk. In 2017, the International Pharmaceutical Federation (FIP) published global policy on workforce development ('the Nanjing Statements') that describe an envisioned future for professional education and training. The documents make clear that expanding the pharmacy workforce benefits patients, and continually improving education and training produces better clinical outcomes. AIMS AND PURPOSE: The opportunities for harnessing new technologies in pharmacy practice have been relatively ignored. This paper presents a conceptual framework for analysing production methods, productivity and technology in pharmacy practice that differentiates between dispensing and pharmaceutical care services. We outline a framework that may be employed to study the relationship between pharmacy practice and productivity, shaped by educational and technological inputs. METHOD AND RESULTS: The analysis is performed from the point of view of health systems economics. In relation to pharmaceutical care (patient-oriented practice), pharmacists are service providers; however, their primary purpose is not to deliver consultations, but to maximise the quantum of health gain they secure. Our analysis demonstrates that 'technology shock' is clearly beneficial compared with orthodox notions of productivity or incremental gain implementations. Additionally, the whole process of providing professional services using 'pharmaceutical care technologies' is governed by local institutional frames, suggesting that activities may be structured differently in different places and countries. DISCUSSION AND CONCLUSION: Addressing problems with medication use with the development of a pharmaceutical workforce that is sufficient in quantity and competence is a long-term issue. As a result of this analysis, there emerges a challenge about the profession's relationship with existing and emerging technical innovations. Our novel framework is designed to facilitate policy, education and research by providing an analytical approach to service delivery. By using this approach, the profession could develop examples of good practice in both developed and developing countries worldwide.

A vapour phase assay for evaluating the antimicrobial activities of essential oils against bovine respiratory bacterial pathogens.

The objectives of this study were to develop a new assay for the evaluation of the antimicrobial activities of essential oils (EOs) in vapour phase and to demonstrate the antimicrobial activities of commercial EOs against BRPs. To achieve the first objective, a microtube cap containing 100 µl of EO was embedded in an agar plate. An agar plug (diameter 13 mm) inoculated with a bacterial suspension containing108  CFU per ml was then placed over the cap and incubated at 37°C for 24 h. Subsequently, bacteria were recovered from the agar plug by immersion in 5 ml of broth for 10 min, followed by vortexing for 30 s, and the broths were then plated for enumeration. To demonstrate the usefulness of the assay, nine commercial EOs derived from the following specific plants: ajowan, carrot seed, cinnamon leaf, citronella, fennel, ginger grass, lavender, rosemary and thyme were first evaluated for their vapour phase antimicrobial activities against Mannheimia haemolytica serotype 1. Selected EOs were further tested against Pasteurella multocida and Histophilus somni. The EOs of ajowan, thyme and cinnamon leaf completely or partially inhibited BRPs growth. This new assay provided reproducible results on the vapour phase antimicrobial activities of EOs against BRPs. These results support further study of EOs as a potential mitigation strategy against BRPs. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we present a new vapour phase assay for evaluating the antimicrobial activities of essential oils (EO) against bovine respiratory pathogens (BRPs). Using this assay, we identified EOs, such as ajowan, thyme and cinnamon leaf, that can effectively inhibit growth of the BRPs Mannheimia haemolytica serotype 1, Pasteurella multocida and Histophilus somni. This is the first study to demonstrate the vapour phase antimicrobial activity of EOs against BRPs.

Can acaricide-impregnated leg bands fitted to female red grouse reduce sheep tick parasitization of chicks and increase chick survival?

In parts of northern England, North Wales and the Scottish Highlands, increasing numbers of sheep ticks Ixodes ricinus (Ixodida: Ixodidae), and the louping ill virus they can carry, are considered to be important factors that reduce red grouse Lagopus lagopus scotica productivity. The present study tested this hypothesis by fitting adult female grouse with leg bands impregnated with the acaricide cypermethrin to experimentally control ticks on their chicks on two managed grouse moors in northeast Scotland. The chicks of females fitted with acaricide leg bands showed reduced tick infestations and improved survival in one of the two study years, relative to chicks of control females. Acaricide leg bands constitute a potential management technique that may be adopted by grouse moor managers in circumstances of high tick infestations on grouse chicks.

The dangers of the day of birth.

OBJECTIVE: To compare the risk of fetal death on the day of childbirth, with the risk of death at other ages, and with the risks of some hazardous activities, on a common scale of risk per day. DESIGN: Review of publicly available data. SETTING UK SAMPLE: Data extracted from the Office of National Statistics and other sources. METHODS: Data from the Office of National Statistics and other sources were used to calculate death rates at different ages expressed as rates per day of life. Death rates for different activities were also calculated as risks per day, or risks per activity, as appropriate. All risks were expressed in micromorts, the number of one in a million chances of dying. Figures on life expectancy (LE) were used to compare potential life years lost. MAIN OUTCOME MEASURES: Daily, or unit of activity, risk of dying for different activities compared with the risk of dying on the day of childbirth. RESULTS: The risk of dying on the day of birth (0.43 per 1000, or 430 micromorts) exceeds that of any other average day of life until the 92nd year. It is comparable with other apparently more dangerous activities, such as undergoing major surgery. For comparison, the average risk of non-natural death per day and the increased risk from smoking one cigarette or travelling 200 miles by car are all about 1 micromort. CONCLUSIONS: The lifetime risk of death in childbirth is low, but is concentrated in a short period, making being born a high-risk activity. Parents considering interventions to reduce these risks should be made aware of this.

Tooth microwear formation rate in Gasterosteus aculeatus.

Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals.

A survey in the West Midlands of the United Kingdom of current practice in managing hypotension in lower segment caesarean section under spinal anaesthesia.

BACKGROUND: Spinal anaesthesia, the most common form of anaesthesia for caesarean section, leads to sympathetic blockade and profound maternal hypotension resulting in adverse maternal and neonatal outcomes. Hypotension, nausea and vomiting remain common but until the publication of the National Institute of Health and Care Excellence (NICE) 2021 guidance, no national guideline existed on how best to manage maternal hypotension following spinal anaesthesia for caesarean section. A 2017 international consensus statement recommended prophylactic vasopressor administration to maintain a systolic blood pressure of >90% of an accurate pre-spinal value, and to avoid a drop to <80% of this value. This survey aimed to assess regional adherence to these recommendations, the presence of local guidelines for management of hypotension during caesarean section under spinal anaesthesia, and the individual clinician's treatment thresholds for maternal hypotension and tachycardia. METHODS: The West Midlands Trainee-led Research in Anaesthesia and Intensive Care Network co-ordinated surveys of obstetric anaesthetic departments and consultant obstetric anaesthetists across 11 National Health Service Trusts in the Midlands, England. RESULTS: One-hundred-and-two consultant obstetric anaesthetists returned the survey and 73% of sites had a policy for vasopressor use; 91% used phenylephrine as the first-line drug but a wide range of recommended delivery methods was noted and target blood pressure was only listed in 50% of policies. Significant variation existed in both vasopressor delivery methods and target blood pressures. CONCLUSIONS: Although NICE has since recommended prophylactic phenylephrine infusion and a target blood pressure, the previous international consensus statement was not adhered to routinely.

Enhanced control of sheep ticks in upland sheep flocks: repercussions for red grouse co-hosts.

Sheep ticks Ixodes ricinus (Acari: Ixodidae) and tick-borne diseases cause major economic losses in both upland sheep farming and moorland shoots of red grouse Lagopus lagopus scoticus. Sheep were treated with acaricide four times between March and October and double-vaccinated against louping ill virus (LIV), instead of the conventional regime of two acaricide treatments and no vaccinations, on two moors in northern England. Enhanced treatment started at Westerdale Moor in 1995 and at Danby Moor in 2000; the latter had previously represented a spatial control site. From 1992 to 2003, grouse chick condition, tick burdens, reproductive success, shooting bags and LIV seroprevalence were measured. A total of 1297 grouse chicks from 398 broods were examined for ticks. Enhanced acaricide treatment reduced tick burdens by 90%, and LIV seroprevalence decreased in relation to the number of years since treatment began. Breeding success and post-breeding densities of grouse in the current sample area remained unrelated to acaricide treatment, tick burdens or LIV seroprevalence, but 25% and 60% more grouse were shot on Westerdale and Danby, respectively, after treatment enhancement than before. By improving shooting bags, tick management schemes help to maintain the economic viability of grouse moors, which, in turn, provide upland landscape and wildlife benefits.

Lipopolysaccharide modifies amiloride-sensitive Na+ transport processes across human airway cells: role of mitogen-activated protein kinases ERK 1/2 and 5.

Bacterial lipopolysaccharides (LPS) are potent inducers of proinflammatory signaling pathways via the activation of nuclear factor-kappa B (NF-kappaB) and mitogen-activated protein kinase (MAPK), causing changes in the processes that control lung fluid homeostasis and contributing to the pathogenesis of lung disease. In human H441 airway epithelial cells, incubation of cells with 15 microg ml(-1) LPS caused a significant reduction in amiloride-sensitive I (sc) from 15 +/- 2 to 8 +/- 2 microA cm(-2) (p = 0.01, n = 13) and a shift in IC(50) amiloride of currents from 6.8 x 10(-7) to 6.4 x 10(-6) M. This effect was associated with a decrease in the activity of 5 pS, highly Na(+) selective, amiloride-sensitive <1 microM channels (HSC) and an increase in the activity of approximately 18 pS, nonselective, amiloride-sensitive >10 microM cation channels (NSC) in the apical membrane. LPS decreased alphaENaC mRNA and protein abundance, inferring that LPS inhibited alphaENaC gene expression. This correlated with the decrease in HSC activity, indicating that these channels, but not NSCs, were comprised of at least alphaENaC protein. LPS increased NF-kappaB DNA binding activity and phosphorylation of extracellular signal-related kinase (ERK)1/2, but decreased phosphorylation of ERK5 in H441 cells. Pretreatment of monolayers with PD98059 (20 microM) inhibited ERK1/2 phosphorylation, promoted phosphorylation of ERK5, increased alphaENaC protein abundance, and reversed the effect of LPS on I (sc) and the shift in amiloride sensitivity. Inhibitors of NF-kappaB activation were without effect. Taken together, our data indicate that LPS acts via ERK signaling pathways to decrease alphaENaC transcription, reducing HSC/ENaC channel abundance, activity, and transepithelial Na(+) transport in H441 airway epithelial cells.

Alveolar epithelial fluid clearance is mediated by endogenous catecholamines at birth in guinea pigs.

Transition from placental to pulmonary oxygenation at birth depends on a rapid removal of fetal lung fluid from the developing alveoli. Alveolar fluid clearance was examined in ventilated, anesthetized developing guinea pigs of the ages newborn, 2-d-old, 5-d-old, 30-d-old, and 60-d-old (adult). An isosmolar 5% albumin solution was instilled into the lungs of the guinea pigs; the guinea pigs were then studied for 1 h. Alveolar fluid clearance was measured from the increase in alveolar protein concentration as water was reabsorbed. Newborn guinea pigs had a very high alveolar fluid clearance rate that declined rapidly within the first 5 postnatal days towards adult levels. The high alveolar fluid clearance at birth was apparently mediated by the beta-adrenergic system as demonstrated by the elevated plasma epinephrine levels and the increased sensitivity to inhibition by the beta-adrenergic antagonist propranolol immediately after birth. Surprisingly, exogenous addition of epinephrine was not able to stimulate alveolar fluid clearance in the newborn lung, but exogenous epinephrine stimulation increased over time to adult levels. The elevated alveolar fluid clearance at birth was associated with a significantly greater amiloride sensitivity in the newborn guinea pig lung. Northern blot analysis of distal lung tissue as well as isolated alveolar epithelial type II cells showed and confirmed higher levels of the alpha-subunit of the epithelial sodium channel mRNA in the newborn lung that rapidly tapered off toward adult levels. In conclusion, these data demonstrate the importance of the beta-adrenergic system and amiloride-sensitive sodium transporting pathways for clearance of fetal lung fluid at birth.

Pharmacological activators of AMP-activated protein kinase have different effects on Na+ transport processes across human lung epithelial cells.

BACKGROUND AND PURPOSE: AMP-activated protein kinase (AMPK) is activated by metformin, phenformin, and the AMP mimetic, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR). We have completed an extensive study of the pharmacological effects of these drugs on AMPK activation, adenine nucleotide concentration, transepithelial amiloride-sensitive (I(amiloride)) and ouabain-sensitive basolateral (I(ouabain)) short circuit current in H441 lung epithelial cells. EXPERIMENTAL APPROACH: H441 cells were grown on permeable filters at air interface. I(amiloride), I(ouabain) and transepithelial resistance were measured in Ussing chambers. AMPK activity was measured as the amount of radiolabelled phosphate transferred to the SAMS peptide. Adenine nucleotide concentration was analysed by reverse phase HPLC and NAD(P)H autofluorescence was measured using confocal microscopy. KEY RESULTS: Phenformin, AICAR and metformin increased AMPK (alpha1) activity and decreased I(amiloride). The AMPK inhibitor Compound C prevented the action of metformin and AICAR but not phenformin. Phenformin and AICAR decreased I(ouabain) across H441 monolayers and decreased monolayer resistance. The decrease in I(amiloride) was closely related to I(ouabain) with phenformin, but not in AICAR treated monolayers. Metformin and phenformin increased the cellular AMP:ATP ratio but only phenformin and AICAR decreased cellular ATP. CONCLUSIONS AND IMPLICATIONS: Activation of alpha1-AMPK is associated with inhibition of apical amiloride-sensitive Na(+) channels (ENaC), which has important implications for the clinical use of metformin. Additional pharmacological effects evoked by AICAR and phenformin on I(ouabain), with potential secondary effects on apical Na+ conductance, ENaC activity and monolayer resistance, have important consequences for their use as pharmacological activators of AMPK in cell systems where Na+K+ATPase is an important component.

Perinatal PTX-sensitive G-protein expression and regulation of conductive 22Na+ transport in lung apical membrane vesicles.

Using apical membrane vesicles (AMV) prepared from mature foetal and early neonatal guinea pig lung we show that pertussis toxin (PTX)-sensitive G-protein regulation of conductive 22Na+ uptake undergoes rapid changes following birth. Thus, G-protein activation by intravesicular incorporation of 100 microM GTPgammaS into vesicles resuspended in NaCl, which in late gestation stimulated uptake, consistently induced inhibition of conductive Na+ uptake into AMV prepared from neonatal lung at 4 days of age (N4) (52+/-9%, n=8, P<0.05). This response was not significantly different in the presence of the relatively impermeant anion isethionate (Ise-) (69+/-9%, n=7, P<0.05). Changes in the regulation of uptake were already detectable on the day of birth (N0) in AMV resuspended in NaCl, with GTPgammaS inducing both stimulatory and inhibitory responses. These data indicate that the processes by which 22Na+ uptake into AMV is regulated by G-proteins undergoes a change at birth and by 4 days of age, G-protein regulation of uptake occurs predominantly via modulation of co-localised Na+ channels. Intravesicular incorporation of GDPbetaS or pre-treatment with PTX did not significantly alter conductive 22Na+ uptake in the presence of NaCl or NaIse suggesting that constitutively active G-proteins are not involved in this process. Pre-treatment of AMV with PTX prevented the inhibition of conductive 22Na+ uptake by GTPgammaS (105+/-16% n=7) indicating that a PTX-sensitive G-protein mediates the inhibition of channels in neonatal AMV. Western blotting demonstrated enrichment of Gialpha1, Gialpha2, Gialpha3 and Goalpha in the apical membrane preparations. We also show that there is a significant rise in the levels of Gialpha3 during the early neonatal period providing a potential candidate for the G-protein mediated changes in regulation of conductive 22Na+ uptake in neonatal AMV.

Differential regulation of Na+ and Cl- conductances by PTX-sensitive G proteins in fetal lung apical membrane vesicles.

In apical membrane vesicles (AMV) prepared from late gestation fetal guinea pig lung we show that conductive 22Na+ uptake is modulated by at least two pathways involving pertussis toxin (PTX)-sensitive G proteins. Intravesicular incorporation of 100 microM GTPgammaS into vesicles resuspended in NaCl caused a significant stimulation (P<0. 05) of conductive Na+ uptake in AMV to 150+/-10% (n=10) of control, whereas GDPbetaS reduced uptake to 65+/-9% (n=4) of control. This contrasting response to GTPgammaS and GDPbetaS is characteristic of a G protein mediated pathway. GTPgammaS induced a significantly smaller stimulation, 125+/-8% (n=5) of control, in the presence of the relatively impermeant anion isethionate (Ise-). Taken together, these data indicate modulation of both Na+ and Cl- channels in the apical membrane by co-localised G protein(s). Treatment with PTX stimulated conductive 22Na+ uptake to 171+/-20% (n=13) of control in AMV resuspended in NaCl, but did not have a significant effect, 94+/-19% of control, in the presence of NaIse indicating the existence of tonic activation of Cl- channels in these AMV under resting conditions. As the combined effects of PTX and GTPgammaS diminished uptake, we propose that the G protein(s) responsible for Na+ channel activation in response to GTPgammaS is PTX-sensitive and that additional PTX-insensitive G proteins might also modulate 22Na+ uptake in these AMV. The presence of Gialpha1, Gialpha2, Gialpha3 and Goalpha in this apical membrane preparation was confirmed by PTX catalysed [32P]ADP-dependent ribosylation and Western blotting. Incubation of AMV with 200 microM DTT caused an inhibition of conductive Na+ uptake in AMV resuspended in NaCl or NaIse to 66+/-8% (n=11) and 64+/-8% (n=6) of control respectively. Pre-treatment with DTT did not affect the ability of GTPgammaS to stimulate conductive Na+ uptake suggesting that the regulation of 22Na+ uptake in late gestation guinea pig fetal lung AMV is unlikely to involve an associated regulatory protein.

New insights into the glucose oxidase stick test for cerebrospinal fluid rhinorrhoea.

Rhinorrhoea is a clinical sign of cerebrospinal fluid (CSF) leakage in patients with skull fracture, but can also be attributable to respiratory secretions or tears. Laboratory tests confirming the presence of CSF are not sufficiently rapid to support clinical decision making in the emergency department and may not be universally available. Detection of glucose in nasal discharge was traditionally used to diagnose CSF leak at the bedside, but has fallen into disuse as it has poor positive predictive value. We propose an algorithm to improve the diagnostic value of this test taking into consideration factors we have found to affect the glucose concentration of respiratory secretions. In patients at risk of CSF leak, nasal discharge is likely to contain CSF if glucose is present in the absence of visible blood, if blood glucose is <6 mmol x L(-1), and if there are no symptoms of upper respiratory tract infection.

Multiple P2Y receptor subtypes in the apical membranes of polarized epithelial cells.

Apical ATP, ATP, UTP and UDP evoked transient increases in short circuit current (I(SC), a direct measure of transepithelial ion transport) in confluent Caco-2 cells grown on permeable supports. These responses were mediated by a population of at least three pharmacologically distinct receptors. Experiments using cells grown on glass coverslips showed that ATP and UTP consistently increased intracellular free calcium ([Ca(2+)](i)) whilst sensitivity to UDP was variable. Cross desensitization experiments suggested that the responses to UTP and ATP were mediated by a common receptor population. Messenger RNA transcripts corresponding to the P2Y(2), P2Y(4) and P2Y(6) receptors genes were detected in cells grown on Transwell membranes by the reverse transcriptase - polymerase chain reaction. Identical results were obtained for cells grown on glass. Experiments in which I(SC) and [Ca(2+)](i) were monitored simultaneously in cells on Transwell membranes, confirmed that apical ATP and UTP increased both parameters and showed that the UDP-evoked increase in I(SC) was accompanied by a [Ca(2+)](i)-signal. Ionomycin consistently increased [Ca(2+)](i) in such polarized cells but caused no discernible change in I(SC). However, subsequent application of apical ATP or UTP evoked a small rise in I(SC) but no rise in [Ca(2+)](i). UDP evoked no such response. As well as evoking increases in [Ca(2+)](i), the ATP/UTP-sensitive receptors present in Caco-2 cells thus allow direct control over ion channels in the apical membrane. The UDP-sensitive receptors, however, appear to simply evoke a rise in [Ca(2+)](i).