First detection of Edwardsiella ictaluri (Proteobacteria: Enterobacteriaceae) in wild Australian catfish

The bacterium Edwardsiella ictaluri is considered to be one of the most significant pathogens of farmed catfish in the United States of America and has also caused mortalities in farmed and wild fishes in many other parts of the world. E. ictaluri is not believed to be present in wild fish populations in Australia, although it has previously been detected in imported ornamental fishes held in quarantine facilities. In an attempt to confirm freedom from the bacterium in Australian native fishes, we undertook a risk-based survey of wild catfishes from 15 sites across northern Australia. E. ictaluri was detected by selective culturing, followed by DNA testing, in Wet Tropics tandan (Tandanus tropicanus) from the Tully River, at a prevalence of 0.40 (95% CI 0.21-0.61). The bacterium was not found in fishes sampled from any of the other 14 sites. This is the first report of E. ictaluri in wild fishes in Australia.

Renal mucous production in Australian freshwater plotosid and ariid catfishes

This study reports the presence of large mucous cells lining the large renal collecting ducts and opisthonephric ducts of the Australian freshwater catfishes Tandanus tandanus and Tandanus tropicanus. Histologic examination of the renal tissue from four other species of Australian freshwater catfishes suggests that this feature is unique to the two species of Tandanus studied. The potential functions of renal mucous secretion in T. tandanus and T. tropicanus are discussed.

Modelling random antibody adsorption and immunoassay activity

One of the primary considerations in immunoassay design is optimizing the concentration of capture antibody in order to achieve maximal antigen binding and, subsequently, improved sensitivity and limit of detection. Many immunoassay technologies involve immobilization of the antibody to solid surfaces. Antibodies are large molecules in which the position and accessibility of the antigen-binding site depend on their orientation and packing density. In this paper we propose a simple mathematical model, based on the theory known as random sequential adsorption (RSA), in order to calculate how the concentration of correctly oriented antibodies (active site exposed for subsequent reactions) evolves during the deposition process. It has been suggested by experimental studies that high concentrations will decrease assay performance, due to molecule denaturation and obstruction of active binding sites. However, crowding of antibodies can also have the opposite effect by favouring upright orientations. A specific aim of our model is to predict which of these competing effects prevails under different experimental conditions and study the existence of an optimal coverage, which yields the maximum expected concentration of active particles (and hence the highest signal).

Can We Predict Post-Hemorrhagic Ventricular Dilatation in Preterm Infants with Severe Intraventricular Hemorrhage?

BACKGROUND: The incidence of post-hemorrhagic ventricular dilatation (PHVD) remains high in preterm infants. Little is known about the risk factors for PHVD in infants with severe intraventricular hemorrhage (IVH).

OBJECTIVES: To determine the predictors of PHVD among preterm infants with severe IVH.

DESIGN/METHODS: We conducted a retrospective review of all pre-term infants (22+0 - 32+6 weeks) who were admitted to NICUs participating in the Canadian Neonatal Network between 2010 and 2014. Infants with severe IVH (IVH with ventricular dilatation or parenchymal bleeding) who survived ≥ 72 hours were included. Perinatal and neonatal risk factors were compared between infants with and without PHVD (lateral ventricles >10 mm).

RESULTS: Of 16600 eligible infants, 1964 (11.8%) developed severe IVH. Of 1815 infants with severe IVH who survived ≥72 hours, 616 (34%) developed PHVD. Factors associated with occurrence of PHVD include: lower gestational age, small for gestational age, low 5 minute Apgar score, SNAPII score>20, surfactant therapy, high frequency oscillatory ventilation (HFOV), inotropes and occurrence of pneumothorax. [table 1]. There were no differences between both groups in relation to antenatal steroids, multiple pregnancy, mode of delivery, birth weight, gender or the proportion received prophylactic indomethacin. Multivariate analysis showed low five-minute Apgar score and HFOV to be independent predictors of PHVD while maternal magnesium sulfate and small for gestation (SGA) to be protective against PHVD.[table 2].

CONCLUSION: Our study identified factors involved in the prediction of PHVD in a national cohort of preterm infants. The mechanisms by which these factors may impact PHVD need further investigation.

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Epidemiology of Posthemorrhagic Ventricular Dilatation in Canadian Neonatal Intensive Care Units

BACKGROUND: Severe intraventricular hemorrhage (IVH) is a common cause of neonatal morbidity and mortality .The incidence and management of post-hemorrhagic ventricular dilatation (PHVD) vary among different centres.

OBJECTIVES: To assess the incidence, temporal trend, management and associated outcomes of PHVD in Canadian NICUs.

DESIGN/METHODS: We conducted a retrospective review of all pre-term infants (22+0 -32+6 weeks) who were admitted to NICUs participating in the Canadian Neonatal Network between 2010 and 2014. Infants with severe IVH (IVH with ventricular dilatation or parenchymal bleeding) who survived ≥ 72 hours were included. We compared the rates of severe IVH, PHVD and VP shunting between the 5 Canadian regions. Short-term outcomes of infants who developed PHVD (ventricles size ≥10 mm) were compared with those who did not.

RESULTS: Of 16600 eligible infants, 1964 (11.8%) developed severe IVH. Of 1815 infants with severe IVH who survived ≥72 hours, 616 (34%) developed PHVD and 91 (5%) treated with VP shunt. No significant difference in the incidence of severe IVH, PHVD or VP shunting over the last five years was noted. There was a statistically significant difference in the rates of severe IVH (p<0.0001) and PHVD (p=0.02) among the 5 Canadian regions. VP shunts rates were variable with some Canadian regions with higher rates of PHVD had low rates of VP shunts. [figure 1]. Infants with PHVD had significantly higher mortality and short term morbidities. [table 1]. On regression analysis, PHVD is an independent predictor of death in infants with severe IVH [adjusted OR 1.55, 95% CI (1.18, 2.04)]. Infants with VP shunt had significantly higher rates of severe ROP (p<0.0001), meningitis (p<0.0001), and hospitalization (89 vs 41 days, p<0.0001).

CONCLUSION: PHVD is an independent predictor of death and is associated with adverse short- term outcomes. Variability exists between different regions in managing PHVD. Further studies are needed to investigate the impact of this variability on long-term outcomes.

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Neurodevelopmental Outcomes in Preterm Infants with Intraventricular Hemorrhage in Canada

BACKGROUND: Conflicting evidence exists in regards to outcomes of infants with mild IVH [subependymal hemorrhage (SEH) and IVH without ventricular dilatation (VD)] with recent reports suggesting poor outcomes.

OBJECTIVES: To compare 1) neurodevelopmental (ND) outcomes of infants < 29 wks GA with normal head ultrasound scan findings (Group 1: no IVH/PVL/VD to those with a) Group 2: SEH or IVH without VD, b) Group 3: IVH with VD (ventricle size > 10 mm) and c) Group 4: persistent intraparenchymal echogenicity (IPE) or lucency with or without IVH and 2) composite outcome of death or ND impairment (NDI)/severe NDI (SNDI) at 18-24 months in these groups.

DESIGN/METHODS: Retrospective cohort study of data from Canadian Neonatal Network (CNN)and Canadian Neonatal Follow-up Network (CNFUN) from April 2010 to September 2011. NDI was defined as any one of Bayley III score < 85 (cognition, language or motor), cerebral palsy (CP) or visual/hearing impairment. SNDI was defined as Bayley III score < 70 for any of the 3 components, CP with GMFCS > 3, severe visual impairment <20/200 or hearing impairment needing aids/cochlear implants. Data for the 4 groups were compared using Chi-squared test or ANOVA as appropriate. Multivariable regression was conducted to obtain adusted OR (95% CI).

RESULTS: See tables on page e51.

Sulfasalazine: A rare cause of acute eosinophilic pneumonia

Sulfasalazine is a compound of 5-aminosalicylic acid (5-ASA) and sulfapyridine joined by an azo bond. It is a widely used drug in the treatment of chronic inflammatory bowel disease. Fatal toxicity of sulfasalazine arises from its effects on the bone marrow and the resulting blood dyscrasias. Pulmonary toxicity from sulfasalazine is a rather rare finding. Here, we present the case of a patient who developed acute eosinophilic pneumonia with sulfasalazine use.

Spiritual well-being and quality of life among Icelanders receiving palliative care: data from Icelandic pilot-testing of a provisional measure of spiritual well-being from the European Organisation for Research and Treatment of Cancer

Palliative care focuses on improving quality of life (QoL). This study examined the feasibility of the Icelandic version of a provisional European Organisation for Research and Treatment of Cancer (EORTC) measure of spiritual well-being (SWB), and explored the relationship between SWB and QoL for palliative care patients in Iceland. Instruments from the EORTC were used: the provisional measure of SWB, which was undergoing pilot-testing in Iceland, and the EORTC QLQ C15-PAL. The correlation between scores was examined and descriptive statistics were used. Structured interviews explored feasibility. Thirty persons participated with average age 72 years. Belief in God or a higher power had the mean 3.33 on a 1-4 scale and the mean for overall SWB was 5.73 on a 1-7 scale. The mean score for global health/QoL was 59.4, physical functioning 48.5 and emotional functioning 78.9 on a 0-100 scale. Overall QoL was positively correlated with SWB showing r(30) = 0.386, P = 0.035. The participants found that answering the provisional EORTC QLQ-SWB prompted an emotional response and took the opportunity to discuss the subject. The provisional SWB measure was found relevant for the Icelandic context, and the study indicates that SWB and QoL are closely connected.

Patients Hospitalised with an Acute Exacerbation of COPD: Is There a Need for a Discharge Bundle of Care?

Acute Exacerbations of COPD (AECOPD) are the commonest cause of hospitalisation for patients with COPD. A number of interventions are known to improve care for such patients. Internationally and in Ireland, there is significant variation in care delivered to such patients. We reviewed admissions with AECOPD (n = 174) to an Irish teaching hospital during one year, to determine if recommended interventions had been delivered to patients prior to discharge. The most frequently delivered of such interventions were: assessment of oxygen requirements 151 (87%) and arrangements for follow-up 135 (78%). The least frequently delivered were: referral for pulmonary rehabilitation 19 (11%) and advice given regarding influenza vaccination 27 (17%). Patients who received care from a respiratory physician or respiratory clinical nurse specialist (RCNS) received more interventions than those cared for by other specialties. This study demonstrates poor compliance with internationally agreed interventions. The introduction of a discharge bundle of care for use in Irish hospitals should be considered.

Disordered breathing during sleep and exercise in idiopathic pulmonary fibrosis and the role of biomarkers

BACKGROUND AND OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) patients report fatigue, possibly reflecting sleep disturbance, but little is known about sleep-related changes. We compared ventilation and gas exchange during sleep and exercise in a cohort of IPF patients, and evaluated associations with selected biological markers.

METHODS

Twenty stable IPF patients (aged 67.9 ± 12.3 [SD]) underwent overnight polysomnography following an acclimatization night. Cardiopulmonary exercise testing was performed and inflammatory markers measured including TNF-α, IL-6, CXCL8, C-C motif ligand 18 (CCL-18) and C-reactive protein (CRP) RESULTS: Nine patients had sleep-disordered breathing (SDB) with an apnea-hypopnea frequency (AHI) ≥ 5/h, but only two had Epworth sleepiness score ≥ 10, thus having an obstructive sleep apnea syndrome. Sleep quality was poor. Transcutaneous carbon dioxide tension (PtcCO2) rose by 2.56 ± 1.59 kPa overnight (P = 0.001), suggesting hypoventilation. Oxygen saturation (SaO2) was lower during sleep than exercise (P < 0.01), and exercise variables correlated with resting pulmonary function. CCL-18 and CRP levels were elevated and correlated with PtcCO2 rise during sleep (P < 0.05). CCL-18 negatively correlated with diffusion capacity of carbon monoxide (DLCO), arterial oxygen (PaO2) and mean arterial carbon dioxide (PaCO2) (P < 0.05) and CRP negatively correlated with DLCO, PaO2, sleep SaO2 and oxygen uptake (VO2) during exercise (P < 0.05).

CONCLUSIONS

IPF patients desaturate more during sleep than exercise; thus, nocturnal pulse oxymetry could be included in clinical assessment. CCL-18 and CRP levels correlate with physiological markers of fibrosis.

The haematology of six species of native catfish from northern Australia

Haematology has the potential to be a valuable tool in determining the health status of wild fish populations and wider ecosystem health. However, limited haematological data are available for wild Australian fish species, and the interpretation and nomenclature of leukocytes is variable and inconsistent in fish. The morphology and cytochemical reactions of erythrocytes, thrombocytes and leukocytes of 189 wild eel-tailed catfish (Tandanus tandanus), Wet Tropics tandan (Tandanus tropicanus), Hyrtyl’s tandan (Neosilurus hyrtlii), black catfish (Neosilurus ater), lesser salmon catfish (Neoarius graeffei), and silver cobbler (Neoarius midgleyi) are described. Erythrocytes, thrombocytes, lymphocytes, monocytes and heterophils in all six species are morphologically similar to those reported in other Siluriformes. Basophils and eosinophils are rarely reported in fish; however basophils were observed in peripheral blood smears of T. tropicanus and N. ater, and eosinophils were observed in N. graeffei. Periodic acid Schiff positive granular leukocytes were observed in N. graeffei, N. midgleyi, N. ater and T. tandanus. This is the first report on the leukocyte morphology and cytochemistry of any native Australian catfish species, and provides useful baseline data for future assessments of fish health and ecosystem integrity in Australia.

Oxygen saturation profile in late-preterm and term infants: a prospective cohort study

OBJECTIVE

To determine oxygen saturation profile over 6 h monitoring period in healthy late-preterm and term neonates during the first 48 h of age, and to assess the impact of gestational age, birth weight and method of delivery on this profile.

STUDY DESIGN

Prospective cohort study of measurement of SpO2 over 6 h in 20 late-preterm (35 to 36 weeks gestation) and 40 term infants within 12 to 48 h of birth was conducted. Infants with cardiorespiratory symptoms or need for cardiorespiratory support at birth were excluded. Percentage time spent at SpO2 >90% and ⩽90% was calculated by gestational age and birth weight.

RESULT

Late-preterm infants and infants born weighing <2.5 kg spent approximately 7% of the time at SpO2 ⩽90%; this time decreased as gestational age and birth weight increased. Time at SpO2 >90% was significantly different between late-preterm and term infants (93% (5%) vs 96% (3%); P =0.002). Time at SpO2 >90% was not significantly different between males and females (95% (5%) vs 95% (4%), both n=30; P =0.72) or between vaginal births and cesarean births (95% (4%), n=32, vs 95% (4%), n=28; P =0.39). Cumulative time with SpO2 <90 was mean (s.d.) of 25 (18) in preterm vs 13 (10) min in term infants.

CONCLUSION

Over a 6-h period healthy late-preterm and term infants spent significant time at SpO2 ⩽90%. Lower gestation and lower birth weight were associated with higher time at SpO2 ⩽90%.

Longitudinal trends in utilization of endocrine therapies for breast cancer: an international comparison

WHAT IS KNOWN AND OBJECTIVE

Endocrine therapy is an effective treatment for post-menopausal women with 'oestrogen receptor-positive' invasive breast cancers. There are two main types of endocrine therapies: selective oestrogen receptor modulators (tamoxifen) and aromatase inhibitors (anastrozole, letrozole and exemestane). The aim of this study was to compare the patterns of use of endocrine therapies for breast cancer in women between nine developed countries.

METHODS

A longitudinal, cross-national drug utilization study was conducted. The endocrine therapies included were tamoxifen and the aromatase inhibitors: anastrozole, letrozole and exemestane. Annual drug utilization data were collected from Australia, Denmark, England, Finland, France, Iceland, the Netherlands, Norway and Sweden over the period 2001-2012. Utilization was measured in DDD/1000 inhabitants/day and was also adjusted for breast cancer incidence and female population statistics.

RESULTS AND DISCUSSION

Total use of endocrine therapies either increased or remained steady in all countries. Total endocrine therapy usage was consistently highest in England and France. Norway showed the lowest usage of endocrine therapies overall, using only 1.80 DDD/1000 inhabitants/day in 2012. Downward trends in tamoxifen use and upward trends in aromatase inhibitors were seen across all countries over the study period. By 2012, aromatase inhibitors represented over half of total endocrine therapy use in all countries, and as high as 74% and 80% in France and Denmark, respectively.

WHAT IS NEW AND CONCLUSION

Our analysis found a shift in use of endocrine therapy from tamoxifen to aromatase inhibitors. This trend is consistent with major clinical guidelines endorsing preferential use of aromatase inhibitors in post-menopausal women. Stabilization or small increase in tamoxifen use in the recent years may reflect the recognition of tamoxifen as still an appropriate first-line treatment. The similarity in utilization patterns may be due to the relatively comparable healthcare systems in the countries, namely universal health insurance and pharmaceutical coverage. Differences in utilization observed could be due to differences in breast cancer incidence, prescribing behaviours, interpretation of new trial evidence, and timing of drug marketing approval and reimbursement between countries.

Efficacy and ligand bias at the μ-opioid receptor

In order to describe drug action at a GPCR, a full understanding of the pharmacological terms affinity, efficacy and potency is necessary. This is true whether comparing the ability of different agonists to produce a measurable response in a cell or tissue, or determining the relative ability of an agonist to activate a single receptor subtype and produce multiple responses. There is a great deal of interest in the μ-opioid receptor (MOP receptor) and the ligands that act at this GPCR not only because of the clinically important analgesic effects produced by MOP agonists but also because of their liability to induce adverse effects such as respiratory depression and dependence. Our understanding of the mechanisms underlying these effects, as well as the ability to develop new, more effective MOP receptor drugs, depends upon the accurate determination of the efficacy with which these ligands induce coupling of MOP receptors to downstream signalling events. In this review, which is written with the minimum of mathematical content, the basic meaning of terms including efficacy, intrinsic activity and intrinsic efficacy is discussed, along with their relevance to the field of MOP receptor pharmacology, and in particular in relation to biased agonism at this important GPCR.

Novel GPCR paradigms at the μ-opioid receptor

Opioids, such as morphine, are the most clinically useful class of analgesic drugs for the treatment of acute and chronic pain. However, the use of opioids is greatly limited by the development of severe adverse side effects. Consequently, drug discovery efforts have been directed towards improving the therapeutic profile of opioid-based treatments. Opioid receptors are members of the family of GPCRs. As such, the recent GPCR paradigms of biased agonism and allosterism may provide novel avenues for more effective analgesics. Biased agonism (or functional selectivity) has been described for all the opioid receptor family members. Furthermore, the first allosteric modulators of opioid receptors have very recently been described. However, identification and quantification of biased agonism in a manner that is informative to medicinal chemists and drug discovery programmes still remains a challenge. In this review, we examine the progress, to date, towards identification and quantification of biased agonism and allosterism at the μ-opioid receptor in the context of its implications for the discovery of better and safer analgesics.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.

Morphine-induced internalization of the L83I mutant of the rat μ-opioid receptor

BACKGROUND AND PURPOSE

Naturally occurring single-nucleotide polymorphisms (SNPs) within GPCRs can result in alterations in various pharmacological parameters. Understanding the regulation and function of endocytic trafficking of the μ-opioid receptor (MOP receptor) is of great importance given its implication in the development of opioid tolerance. This study has compared the agonist-dependent trafficking and signalling of L83I, the rat orthologue of a naturally occurring variant of the MOP receptor.

EXPERIMENTAL APPROACH

Cell surface elisa, confocal microscopy and immunoprecipitation assays were used to characterize the trafficking properties of the MOP-L83I variant in comparison with the wild-type receptor in HEK 293 cells. Functional assays were used to compare the ability of the L83I variant to signal to several downstream pathways.

KEY RESULTS

Morphine-induced internalization of the L83I MOP receptor was markedly increased in comparison with the wild-type receptor. The altered trafficking of this variant was found to be specific to morphine and was both G-protein receptor kinase- and dynamin-dependent. The enhanced internalization of L83I variant in response to morphine was not due to increased phosphorylation of serine 375, arrestin association or an increased ability to signal.

CONCLUSIONS AND IMPLICATIONS

These results suggest that morphine promotes a specific conformation of the L83I variant that makes it more liable to internalize in response to morphine, unlike the wild-type receptor that undergoes significantly less morphine-stimulated internalization, providing an example of a ligand-selective biased receptor. The presence of this SNP within an individual may consequently affect the development of tolerance and analgesic responses.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.