CH4 and N2 O emissions from smallholder agricultural systems on tropical peatlands in Southeast Asia

There are limited data for greenhouse gas (GHG) emissions from smallholder agricultural systems in tropical peatlands, with data for non-CO2 emissions from human-influenced tropical peatlands particularly scarce. The aim of this study was to quantify soil CH4 and N2 O fluxes from smallholder agricultural systems on tropical peatlands in Southeast Asia and assess their environmental controls. The study was carried out in four regions in Malaysia and Indonesia. CH4 and N2 O fluxes and environmental parameters were measured in cropland, oil palm plantation, tree plantation and forest. Annual CH4 emissions (in kg CH4 ha-1  year-1 ) were: 70.7 ± 29.5, 2.1 ± 1.2, 2.1 ± 0.6 and 6.2 ± 1.9 at the forest, tree plantation, oil palm and cropland land-use classes, respectively. Annual N2 O emissions (in kg N2 O ha-1  year-1 ) were: 6.5 ± 2.8, 3.2 ± 1.2, 21.9 ± 11.4 and 33.6 ± 7.3 in the same order as above, respectively. Annual CH4 emissions were strongly determined by water table depth (WTD) and increased exponentially when annual WTD was above -25 cm. In contrast, annual N2 O emissions were strongly correlated with mean total dissolved nitrogen (TDN) in soil water, following a sigmoidal relationship, up to an apparent threshold of 10 mg N L-1 beyond which TDN seemingly ceased to be limiting for N2 O production. The new emissions data for CH4 and N2 O presented here should help to develop more robust country level 'emission factors' for the quantification of national GHG inventory reporting. The impact of TDN on N2 O emissions suggests that soil nutrient status strongly impacts emissions, and therefore, policies which reduce N-fertilisation inputs might contribute to emissions mitigation from agricultural peat landscapes. However, the most important policy intervention for reducing emissions is one that reduces the conversion of peat swamp forest to agriculture on peatlands in the first place.

Growth dynamics and amorphous-to-crystalline phase transformation in natural nacre

Biominerals, such as nacreous bivalve shells, are important archives of environmental information. Most marine calcifiers form their shells from amorphous calcium carbonate, hypothesised to occur via particle attachment and stepwise crystallisation of metastable precursor phases. However, the mechanism of this transformation, including the incorporation of trace elements used for environmental reconstructions, are poorly constrained. Here, using shells of the Mediterranean mussel, we explore the formation of nacre from the meso- to the atomic scale. We use a combination of strontium pulse-chase labelling experiments in aquaculture and correlated micro- to sub-nanoscale analysis to show that nacre grows in a dynamic two-step process with extensional and space-filling growth components. Furthermore, we show that nacre crystallizes via localised dissolution and reprecipitation within nanogranules. Our findings elucidate how stepwise crystallization pathways affect trace element incorporation in natural biominerals, while preserving their intricate hierarchical ultrastructure.

The psychological impact of Stevens-Johnson syndrome and toxic epidermal necrolysis on patients' lives: a Critically Appraised Topic

CLINICAL SCENARIO

A 65-year-old man presented with a 12-h history of deteriorating rash. Two weeks previously he had completed a course of neoadjuvant chemotherapy for ductal carcinoma of the breast. On examination there were bullae, widespread atypical targetoid lesions and 15% epidermal detachment. There was no mucosal involvement on presentation, but subsequently it did evolve. Skin biopsy showed subepidermal blistering with epidermal necrosis. This confirmed our clinical diagnosis of overlap Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). On transfer to intensive care he was anxious and fearful.

MANAGEMENT QUESTION

What are the psychological impacts of SJS/TEN on this man's life?

BACKGROUND

SJS and TEN have devastating outcomes for those affected.

OBJECTIVES

To conduct a Critically Appraised Topic to (i) analyse existing research related to the psychological impact of SJS and TEN and (ii) apply the results to the clinical scenario.

METHODS

Seven electronic databases were searched for publications focusing on the psychological impact of SJS/TEN on adults over 18 years of age.

RESULTS

Six studies met the inclusion criteria. Healthcare practitioners' (HCPs') lack of information around the disorder was highlighted. Patients experienced undue stress and fear. Some patients had symptoms aligned to post-traumatic stress disorder (PTSD), anxiety and depression.

DISCUSSION AND RECOMMENDATION

The evidence suggests that SJS and TEN impact psychologically on patients' lives. Education of HCPs, to address their lack of awareness and information on SJS/TEN, should facilitate their capacity to provide information and support to patients, thereby reducing patient anxiety. On discharge, a follow-up appointment with relevant HCPs to reduce the possibility of PTSD occurring should be considered.

Rotavirus Gastroenteritis is Associated with Increased Morbidity and Mortality in Children with Inherited Metabolic Disorders

Rotavirus is the leading cause of infantile diarrhoea worldwide in children <5 years1. Although mortality rates are low in Ireland, certain populations are more susceptible to the associated morbidity and mortality of infection. A retrospective chart review of 14 patients with confirmed IMDs who were admitted to Temple Street Children's Hospital between 2010 to 2015 with rotavirus infection were compared with 14 randomly selected age matched controls. The median length of stay was 7 days (SD25.3) in IMD patients versus 1.5 days (SD 2.1) in the controls. IV fluids were required on average for 4.5 days (range 0-17) in IMD patients versus 0.63 days (range 0-3) in controls. This report highlights the increased morbidity of rotavirus infection in patients with IMD compared to healthy children. This vulnerable population are likely to benefit from the recent introduction of the rotavirus oral vaccination in October 2016.

Keep wetlands wet: the myth of sustainable development of tropical peatlands - implications for policies and management

Pristine tropical peat swamp forests (PSFs) represent a unique wetland ecosystem of distinctive hydrology which support unique biodiversity and globally significant stores of soil carbon. Yet in Indonesia and Malaysia, home to 56% of the world's tropical peatland, they are subject to considerable developmental pressures, including widespread drainage to support agricultural needs. In this article, we review the ecology behind the functioning and ecosystem services provided by PSFs, with a particular focus on hydrological processes as well as the role of the forest itself in maintaining those services. Drawing on this, we review the suitability of current policy frameworks and consider the efficacy of their implementation. We suggest that policies in Malaysia and Indonesia are often based around the narrative of oil palm and other major monocrops as drivers of prosperity and development. However, we also argue that this narrative is also being supported by a priori claims concerning the possibility of sustainability of peat swamp exploitation via drainage-based agriculture through the adherence to best management practices. We discuss how this limits their efficacy, uptake and the political will towards enforcement. Further, we consider how both narratives (prosperity and sustainability) clearly exclude important considerations concerning the ecosystem value of tropical PSFs which are dependent on their unimpacted hydrology. Current research clearly shows that the actual debate should be focused not on how to develop drainage-based plantations sustainably, but on whether the sustainable conversion to drainage-based systems is possible at all.

A Prospective Analysis of the Relationship between Chronic Diseases and Adiposity in older adults: Findings from the Lifeways Cross-Generation Cohort Study of a Thousand Families 2001-2014

This study assesses the relationship between body mass index (BMI) and adult chronic diseases (diabetes mellitus type 2 [DM2], cardiovascular diseases [CVD] and cancers), in grandparents in the Lifeways Cross-Generation Cohort Study. BMI was either measured or reported, at baseline or 10-year follow-up, in 1,244 grandparents. Cumulative morbidity data were recorded at baseline, 3 and 10-year follow-up through questionnaires, General Practice note search, or both. Just over 42% of grandparents were overweight and 32.1% obese. In the multivariate analysis BMI showed a strong linear association with both DM2 (ptrend <0.001) and CVD (ptrend <0.001). There were no significant associations with cancers, but case numbers were small. Results were similar for waist circumference. This prospective study presents novel Irish data and confirms other recent Irish cross-sectional reports on adiposity and adult chronic disease, highlighting the need for effective health promotion interventions in older adults.

The Bhutani Nomogram Reduces Incidence of Severe Hyperbilirubinaemia in Term and Near Term Infants

Very high bilirubin levels can have devastating neurodevelopmental effects on infants including hearing loss and cerebral palsy. A previous study in our institution determined the rate of, and factors associated with, bilirubin values above exchange transfusion level. Since this study the Bhutani nomogram was introduced to help identify infants at risk of severe hyperbilirubinaemia. In our study we looked at the initial serum bilirubin taken in infants 36 weeks and 2.5 kgs. Our results show that since this nomogram was introduced there has been a significant reduction in the number of infants reaching exchange transfusion levels. We also showed that the Bhutani nomogram could successfully be used in a population of unknown direct Coombs status.

Mental health service users' experiences of mental health care: an integrative literature review

A number of studies have highlighted issues around the relationship between service users and providers. The recovery model is predominant in mental health as is the recognition of the importance of person-centred practice. The authors completed an in-depth search of the literature to answer the question: What are service users' experiences of the mental health service? Three key themes emerged: acknowledging a mental health problem and seeking help; building relationships through participation in care; and working towards continuity of care. The review adds to the current body of knowledge by providing greater detail into the importance of relationships between service users and providers and how these may impact on the delivery of care in the mental health service. The overarching theme that emerged was the importance of the relationship between the service user and provider as a basis for interaction and support. This review has specific implications for mental health nursing. Despite the recognition made in policy documents for change, issues with stigma, poor attitudes and communication persist. There is a need for a fundamental shift in the provider-service user relationship to facilitate true service-user engagement in their care. The aim of this integrative literature review was to identify mental health service users' experiences of services. The rationale for this review was based on the growing emphasis and requirements for health services to deliver care and support, which recognizes the preferences of individuals. Contemporary models of mental health care strive to promote inclusion and empowerment. This review seeks to add to our current understanding of how service users experience care and support in order to determine to what extent the principles of contemporary models of mental health care are embedded in practice. A robust search of Web of Science, the Cochrane Database, Science Direct, EBSCO host (Academic Search Complete, MEDLINE, CINAHL Plus Full-Text), PsycINFO, PsycARTICLES, Social Sciences Full Text and the United Kingdom and Ireland Reference Centre for data published between 1 January 2008 and 31 December 2012 was completed. The initial search retrieved 272 609 papers. The authors used a staged approach and the application of predetermined inclusion/exclusion criteria, thus the numbers of papers for inclusion were reduced to 34. Data extraction, quality assessment and thematic analysis were completed for the included studies. Satisfaction with the mental health service was moderately good. However, accessing services could be difficult because of a lack of knowledge and the stigma surrounding mental health. Large surveys document moderate satisfaction ratings; however, feelings of fear regarding how services function and the lack of treatment choice remain. The main finding from this review is while people may express satisfaction with mental health services, there are still issues around three main themes: acknowledging a mental health problem and seeking help; building relationship through participation and care; and working towards continuity of care. Elements of the recovery model appear to be lacking in relation to user involvement, empowerment and decision making. There is a need for a fundamental shift in the context of the provider-service user relationship to fully facilitate service users' engagement in their care.

SLK-mediated phosphorylation of paxillin is required for focal adhesion turnover and cell migration

Focal adhesion turnover is a complex process required for cell migration. We have previously shown that the Ste20-like kinase (SLK) is required for cell migration and efficient focal adhesion (FA) turnover in a FA kinase (FAK)-dependent manner. However, the role of SLK in this process remains unclear. Using a candidate substrate approach, we show that SLK phosphorylates the adhesion adapter protein paxillin on serine 250. Serine 250 phosphorylation is required for paxillin redistribution and cell motility. Mutation of paxillin serine 250 prevents its phosphorylation by SLK in vitro and results in impaired migration in vivo as evidenced by an accumulation of phospho-FAK-Tyr397 and altered FA turnover rates. Together, our data suggest that SLK phosphorylation of paxillin on serine 250 is required for FAK-dependent FA dynamics.

Outlier SNPs show more genetic structure between two Bay of Fundy metapopulations of Atlantic salmon than do neutral SNPs

Atlantic salmon of Eastern Canada were once of considerable importance to aboriginal, recreational, and commercial fisheries, yet many populations are now in decline, particularly those of the inner Bay of Fundy (iBoF), which were recently listed as endangered. We investigated whether nonneutral SNPs could be used to assign individual Atlantic salmon accurately to either the iBoF or the outer Bay of Fundy (oBoF) metapopulations because this has been difficult with existing neutral markers. We first searched for markers under diversifying selection by genotyping eight captively bred Bay of Fundy (BoF) populations for 320 SNP loci with the Sequenom MassARRAY™ system and then analysed the data set with four different F(ST) outlier detection programs. Three outlier loci were identified by both BayesFST and BayeScan whereas seven outlier loci, including the three previously mentioned, were identified by both Fdist and Arlequin. A subset of 14 nonneutral SNPs was more accurate (85% accuracy) than a subset of 67 neutral SNPs (75% accuracy) at assigning individual salmon back to their metapopulation. We then chose a subset of nine outlier SNP markers and used them to inexpensively genotype archived DNA samples from seven wild BoF populations using Invader™ chemistry. Hierarchical AMOVA of these independent wild samples corroborated our previous findings of significant genetic differentiation between iBoF and oBoF salmon metapopulations. Our research shows that identifying and using outlier loci is an important step towards achieving the goal of consistently and accurately distinguishing iBoF from oBoF Atlantic salmon, which will aid in their conservation.

Relative risks of inbreeding and outbreeding depression in the wild in endangered salmon

Conservation biologists routinely face the dilemma of keeping small, fragmented populations isolated, wherein inbreeding depression may ensue, or mixing such populations, which may exacerbate population declines via outbreeding depression. The joint evaluation of inbreeding and outbreeding risks in the wild cannot be readily conducted in endangered species, so a suggested ‘safe’ strategy is to mix ecologically and genetically similar populations. To evaluate this strategy, we carried out a reciprocal transplant experiment involving three neighboring populations of endangered Atlantic salmon (Salmo salar) now bred in captivity and maintained in captive and wild environments. Pure, inbred, and outbred (first and second generation) cross types were released and recaptured in the wild to simultaneously test for local adaptation, inbreeding depression, and outbreeding depression. We found little evidence of inbreeding depression after one generation of inbreeding and little evidence of either heterosis or outbreeding depression via genetic incompatibilities after one or two generations of outbreeding. A trend for outbreeding depression via the loss of local adaptation was documented in one of three populations. The effects of inbreeding were not significantly different from the effects of outbreeding. Hence, at the geographic scale evaluated (34–50 km), inbreeding for one generation and outbreeding over two generations may have similar effects on the persistence of small populations. The results further suggested that outbreeding outcomes may be highly variable or unpredictable at small genetic distances. Our work highlights the necessity of evaluating the relative costs of inbreeding and outbreeding in the conservation and management of endangered species on a case-by-case basis.

Consequences of farmed-wild hybridization across divergent wild populations and multiple traits in salmon

Theory predicts that hybrid fitness should decrease as population divergence increases. This suggests that the effects of human-induced hybridization might be adequately predicted from the known divergence among parental populations. We tested this prediction by quantifying trait differentiation between multigenerational crosses of farmed Atlantic salmon (Salmo salar) and divergent wild populations from the Northwest Atlantic; the former escape repeatedly into the wild, while the latter are severely depleted. Under common environmental conditions and at the spatiotemporal scale considered (340 km, 12 000 years of divergence), substantial cross differentiation had a largely additive genetic basis at behavioral, life history, and morphological traits. Wild backcrossing did not completely restore hybrid trait distributions to presumably more optimal wild states. Consistent with theory, the degree to which hybrids deviated in absolute terms from their parental populations increased with increasing parental divergence (i.e., the collective environmental and life history differentiation, genetic divergence, and geographic distance between parents). Nevertheless, while these differences were predictable, their implications for risk assessment were not: wild populations that were equally divergent from farmed salmon in the total amount of divergence differed in the specific traits at which this divergence occurred. Combined with ecological data on the rate of farmed escapes and wild population trends, we thus suggest that the greatest utility of hybridization data for risk assessment may be through their incorporation into demographic modeling of the short- and long-term consequences to wild population persistence. In this regard, our work demonstrates that detailed hybridization data are essential to account for life-stage-specific changes in phenotype or fitness within divergent but interrelated groups of wild populations. The approach employed here will be relevant to risk assessments in a range of wild species where hybridization with domesticated relatives is a concern, especially where the conservation status of the wild species may preclude direct fitness comparisons in the wild.

The Ste20-like kinase SLK is required for ErbB2-driven breast cancer cell motility

The Ste20-like kinase, SLK, is involved in the control of cell motility through its effects on actin reorganization and focal adhesion turnover. Here we investigated the role of SLK in chemotaxis downstream of the tyrosine kinase receptor, HER2/ErbB2/Neu, which is frequently overexpressed in human breast cancers. Our results show that SLK is required for the efficient cell migration of human and mouse mammary epithelial cell lines in the presence of the Neu activator, heregulin, as a chemoattractant. SLK activity is stimulated by heregulin treatment or by overexpression of activated Neu. Phosphorylation of tyrosine 1201 or tyrosines 1226/7 on Neu is a key event for SLK activation and cell migration, and cancer cell invasion mediated by these tyrosines is inhibited by kinase-inactive SLK. Signaling pathway inhibitors show that Neu-mediated SLK activation is dependent on MEK, PI3K, PLCgamma and Shc signaling. Furthermore, heregulin-stimulated SLK activity requires signals from the focal adhesion proteins, FAK and src. Finally, phospho-FAK analysis shows that SLK is required for Neu-dependent focal adhesion turnover. Together, these studies define an interaction between Neu and SLK signaling in the regulation of cancer cell motility.

Clarithromycin with low dose dexamethasone and thalidomide is effective therapy in relapsed/refractory myeloma

A combination of clarithromycin, low dose of thalidomide and low dose dexamethasone was used in a phase II study to treat patients with relapsed and refractory myeloma. Thirty patients received clarithromycin 250 mg twice daily and thalidomide 50 mg at night on an ongoing basis with 4-d pulses of 10 mg dexamethasone given monthly. Eight patients had permitted escalation of thalidomide dosage up to 200 mg daily. The combination was well tolerated and could be given to elderly, infirm and severely cytopenic patients. Response rates were high, with 89% achieving at least 50% reduction in paraprotein and a 96% overall response rate. Although clarithromycin has only minimal anti-myeloma properties when used as a single agent, its combination with thalidomide and dexamethasone appears very effective, allowing these to be used in lower and more tolerable doses with good clinical effects.

A comparative study of the effect of hydrogen peroxide versus normal saline on the strength of the bone-cement interface

Hydrogen peroxide has been used for decades as an effervescent haemostatic agent in arthroplasty. Recently it has been shown to adversely affect the material properties of PMMA. We aim to assess whether any such deleterious effects are demonstrated in an experimental model which mimics the clinical use of hydrogen peroxide. Matched pairs of cancellous bone samples were treated with a swab soaked in either saline or a 3% solution of hydrogen peroxide, prior to manufacture of cement-bone constructs using Palacos or Simplex cement. Thirty pairs were then compared by subjecting them to a torsional shear force until failure and a further thirty pairs were tested to failure in tension. There was no significant difference between the mean torques to failure for the Palacos-peroxide group versus the Palacos-saline group, or the Simplex-peroxide versus the Simplex-saline group (p=0.31 and 0.71 respectively). Similarly there was no significant difference between the mean tension loads to failure for the Palacos-peroxide group versus the Palacos-saline group, and the Simplex-peroxide versus the Simplex-saline group (p=0.79 and 0.23 respectively). We conclude that the use of hydrogen peroxide as an effervescent haemostatic agent has no detrimental effect on the mechanical integrity of the bone-cement interface when compared to normal saline.

Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European Union

Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Association's guideline of <200 CFU x ml(-1) for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n = 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4- to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU x ml(-1). Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU x ml(-1), although occasional high values (up to 4.88 log CFU x ml(-1)) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.

Diclofenac for treatment of nocturia caused by nocturnal polyuria: a prospective, randomised, double-blind, placebo-controlled crossover study

OBJECTIVES

To investigate the efficacy of diclofenac 50 mg enteric-coated tablet (Non-Steroidal Anti-Inflammatory Drug) in the treatment of nocturnal polyuria.

MATERIALS AND METHODS

26 patients (20 male and 6 female) with a mean age of 72 years (range 52-90) diagnosed with nocturnal polyuria were recruited. The study period comprised 2 weeks of either placebo or active medication taken at 2100 h. Following one-week rest period, patients were crossed over to the other medication for a further 2 weeks. Frequency volume charts were completed during the second week of each of the two study periods along with feedback forms to assess any subjective improvement in symptoms during each of the study periods.

RESULTS

A significant improvement in the symptoms was noted for diclofenac when compared with the placebo. The mean nocturnal frequency decreased from 2.7 to 2.3 (p<0.004) and the mean ratio of night-time to 24 h urine volume decreased from 44% to 39% (p<0.001). No significant side effects were reported.

CONCLUSIONS

NSAIDs are effective in the treatment of nocturnal polyuria causing a decrease in nocturnal frequency with subjective symptom improvement. Our study suggests a novel treatment option for this common condition.

Diethylstilboestrol versus bicalutamide in hormone refractory prostate carcinoma: a prospective randomized trial

OBJECTIVE

To compare the efficacy of diethylstilboestrol (DES) with bicalutamide in the treatment of hormone refractory prostate cancer in relation to its effect on prostate-specific antigen (PSA) and survival.

METHODS

Patients on LHRH analogues for prostate carcinoma with evidence of biochemical or clinical progression were randomized into one of the treatment arms (n=58). The first group (group A, n=26) received 1 mg of DES with 75 mg of aspirin per day in addition to the primary hormonal treatment. The second group (group B, n=32) received bicalutamide at a dose of 50 mg/day in addition to the primary treatment. Patients were followed up every 3 months with their PSA being checked and were also monitored for any clinical progression and adverse effects as a result of treatment. Any adverse event occurring after patients were started on treatment was attributed to the drug and patients were clinically assessed at each visit. Failure of treatment was defined as a 50% or greater increase in PSA after commencing treatment. Once randomized, all patients were followed up for survival regardless of failure of second-line hormonal manipulation.

RESULTS

The mean age of the patients was 76.7 years (60-88, SD 7.4) in group A and 76 years (67-86, SD 6.9) in group B. Twelve patients in each group had metastatic disease. The median follow-up periods for both groups were 24 months (range 6-48 in group A, range 3-54 in group B). 65% of the patients in group A (17/26) and 43.5% (14/32) in group B had a fall in their PSA levels (p=0.08, Fisher's exact test) with 23% (6/26) and 31% (10/32) having a >50% response respectively (p=0.34, Fisher's exact test). Mean PSA nadir in those who responded were 20.6 ng/ml (range 1.6-59.4) and 7.41 ng/ml (range 0.1-42.6) in groups A and B respectively. The median duration of response was 9 months (3-18 months) for group A and 12 months (3-18 months) for group B. Seven patients in group A and 6 in group B experienced adverse events. Three of the 7 in the group A experienced cardiovascular related adverse effects (1 congestive cardiac failure, 1 pulmonary embolism and 1 stroke). At the end of the study period, 14 (54%) of group A patients were alive and 12 (46%) were dead. In group B, 15 (47%) were alive, 16 (50%) were dead and 1 (3%) lost to follow-up. At the completion of the study, 3 patients in each group were still on treatment.

CONCLUSION

Low-dose DES and 50 mg of bicalutamide per day are equally effective in hormone refractory prostate carcinoma with respect to biochemical response, although DES has more severe adverse effects. This is a small sample and larger multicentre trials are needed to give us a definite conclusion.

Microbial contamination of dental unit water systems

INTRODUCTION

Dental unit water systems (DUWS) may serve as a reservoir for biofilms that contribute to high numbers of bacteria in the water used during dental treatment. These microbes are predominantly harmless but potentially pathogenic organisms can also be present in the biofilm. This may pose a potential health risk for patients and dental personnel.

AIM

to determine the microbial levels of DUWS in dental practices.

MATERIALS AND METHOD

A cross-sectional study of water and tubing samples from 30 general dental practices (15 health board and 15 private surgeries) was undertaken as part of a pan-European investigation of the microbial qualitative and quantitative aspects of DUWS.

RESULTS

Microbial loads ranged from 100 to 104 cfu ml-1 and exceeded the European guidelines for drinking water in many cases. The available evidence suggested the presence of isolates most likely belonging to families of aquatic and soil bacteria. It was not possible to draw distinct conclusions correlating microbial loads with dental unit parameters, including age of the unit, water source and chemistry and presence or absence of anti-retraction devices. Opportunistic or true pathogens were not detected. Yeasts were observed in samples from three units although further analysis confirmed that these were not Candida albicans. A decontamination strategy applied to one of the units eliminated the yeasts completely.

CONCLUSIONS

Dental practitioners must be knowledgeable regarding microbial contamination and biofilm formation in dental unit waterlines. There is a need for development of European evidence-based guidelines and reliable control regimes for microbial contamination of DUWS.

The fatigue strength of compact bone in torsion

We have conducted a series of fatigue tests on samples of bovine compact bone loaded in cyclic torsion. The fatigue strength (i.e. the range of stress needed to cause failure in a given number of cycles) was found to be lower than the fatigue strength of the same material in compression by more than a factor of two. We also tested intact chicken metatarsals and found a similar reduction in strength compared to compression testing of chicken tibiae. These results were predicted using a theoretical model in which fatigue failure was assumed to be dependent on the growth of microcracks, oriented approximately parallel to the bone's longitudinal axis but having misorientation angles of up to 30 degrees. An effective stress range was derived which is a function of the normal and shear stresses, and thus of the Mode I and Mode II stress intensities experienced by the crack. These results may have important consequences for the understanding of fatigue in bone in vivo; relatively small amounts of longitudinal shear stress, which are often ignored in analysis, may contribute significantly to fatigue failures. This may shed light on the phenomenon of stress fractures and on the need for repair and adaptation in living bone.

Cardiac rhythm disturbances in the obstructive sleep apnea syndrome: effects of nasal continuous positive airway pressure therapy

STUDY OBJECTIVES

A high incidence of nocturnal cardiac rhythm disturbances among patients with obstructive sleep apnea (OSA) syndrome has been described in some reports, but not in others. We wished to examine the prevalence of significant cardiac rhythm disturbance in patients with established moderate to severe OSA syndrome and, in particular, to assess the impact of nasal continuous positive airway pressure (nCPAP) therapy.

DESIGN AND SETTING

A prospective study of consecutive eligible patients in a dedicated sleep disorders unit of a university teaching hospital.

MEASUREMENTS AND RESULTS

Holter monitoring was performed for 18 h in 45 patients with previously diagnosed OSA syndrome (mean [SD] apnea/hypopnea frequency [AHI] of 50 [23]/h) and repeated within 2 to 3 days after institution of nCPAP therapy. Investigators were blinded to the patients' treatments during data analysis. Thirty-five patients were found to have some cardiac rhythm disturbance, but only 8 had pathologically significant disturbances (ventricular tachycardia or fibrillation, complex ventricular ectopy, new-onset supraventricular tachycardia other than sinus tachycardia, pauses of > 2 s, and second- or third-degree heart block). Significant rhythm disturbances occurred only during the nighttime, and there was a significant correlation between OSA severity and the severity of rhythm disturbance (p = 0.04, r = 0.301). No significant correlation was found between OSA severity and any other anthropometric parameter measured. nCPAP therapy resulted in abolition of rhythm disturbance in seven of these eight patients; the eighth patient was found to have coexisting severe aortic valve disease requiring valve replacement.

CONCLUSION

The data indicate that OSA syndrome predisposes to clinically significant cardiac rhythm disturbances that can be successfully controlled by nCPAP therapy.

An assessment of the aggressive potential of radiolucencies related to the mandibular molar teeth

AIM

The purpose of this study was to outline the radiographic appearance of radiolucent lesions related to the molar teeth and to determine which features indicate aggressive lesions.

PATIENTS AND METHODS

Panoramic radiographs were reviewed in 66 patients with radiolucencies related to the molar teeth. The radiographic appearances of the lesions were assessed with regard to location and size, and the relationship to the molar teeth. Radiographic evidence of aggression was assessed and pathology reviewed.

RESULTS

Nineteen patients had aggressive and 47 had non-aggressive radiolucent lesions. The aggressive lesions included keratocysts, unicystic ameloblastoma, adenoid cystic carcinoma, giant cell granuloma, myxofibroma, chondroblastic osteosarcoma, mestastases and squamous cell carcinoma of the tongue invading the mandible.

CONCLUSION

The differential diagnosis of radiolucent lesions in the mandible can be difficult using panoramic radiographs alone. Helpful features in determining aggression were older patients, larger lesions, Lodwick type IC tumour border, condition of the mandibular cortex, movement of adjacent teeth and the relationship of the inferior alveolar canal.

Compression data on bovine bone confirms that a "stressed volume" principle explains the variability of fatigue strength results

The literature contains many measurements of the fatigue properties of compact bone, but these experimental results have been difficult to interpret and use due to a large amount of apparent scatter: variation in the number of cycles to failure for a given cyclic stress or strain range. Recently Taylor (1998a, Journal of Orthopaedic Research, 16, 163-169) showed that much of this scatter could be explained using a statistical model which took into account specimen size, or more specifically stressed volume. The present paper describes an attempt to test this model by using it to predict some new data, for bovine bone tested in compressive loading at room temperature at physiological loading rates. Twenty specimens were tested at the same applied load range (100 MPa). The theory was able to predict the mean behaviour of the specimens very well, with an accuracy (expressed in terms of stress) of 2%. It was also able to predict the degree of scatter (i.e. the variation of Nf), which was shown to be similar to that measured by other workers.

Identification of a CD4 domain required for interleukin-16 binding and lymphocyte activation

Interleukin-16 (IL-16) activates CD4(+) cells, possibly by direct interaction with CD4. IL-16 structure and function are highly conserved across species, suggesting similar conservation of a putative IL-16 binding site on CD4. Comparison of the human CD4 amino acid sequence with that of several different species revealed that immunoglobulin-like domain 4 is the most conserved extracellular region. Potential interaction of this domain with IL-16 was studied by testing murine D4 sequence-based oligopeptides for inhibition of IL-16 chemoattractant activity and inhibition of IL-16 binding to CD4 in vitro. Three contiguous 12-residue D4 region peptides (designated A, B, and C) blocked IL-16 chemoattractant activity, with peptide B the most potent. Peptides A and B were synergistic for inhibition, but peptide C was not. Peptides A and B also blocked IL-16 binding to CD4 in vitro, whereas peptide C did not. CD4, in addition to its known function as a receptor for major histocompatibility complex class II, contains a binding site for IL-16 in the D4 domain. The D4 residues required for IL-16 binding overlap those previously shown to participate in CD4-CD4 dimerization following class II major histocompatibility complex binding, providing a mechanistic explanation for the known function of IL-16 to inhibit the mixed lymphocyte reaction.

The spectrum of mycobacterial disease in a Dublin teaching hospital

We describe our experience at our combined tuberculosis and public health clinic, which has been in existence since 1991, and compare it to a previous review of tuberculosis at St. Vincent's Hospital from 1974 to 1979. A total of 107 patients were treated, 58 male and 49 female, with a mean age of 53 years. Seventy-seven patients had pulmonary tuberculosis, 23 extrapulmonary and three had both. Four patients had miliary tuberculosis. Our figures reflect the fall in incidence of tuberculosis in Ireland since the 1970's and a rise in smear negative and presumptive cases. The epidemiology of tuberculosis in Ireland is little changed except for an increasing impact of immigration. Problems such as late diagnosis, especially in older patients, and non-compliance remain significant. In addition, there were four deaths from tuberculosis. However, our combined clinic has led to the appropriate management of patients by Respiratory Medicine specialists and a great move to ambulatory diagnosis and management. We believe it is the best model for the effective management of tuberculosis in Ireland.

Consensus on renal cortical scintigraphy in children with urinary tract infection. Scientific Committee of Radionuclides in Nephrourology

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.

Consensus on diuresis renography for investigating the dilated upper urinary tract. Radionuclides in Nephrourology Group. Consensus Committee on Diuresis Renography

There is great variation in technique and interpretation of diuresis renography between different establishments.

METHODS

To address this problem, an International Consensus Committee was appointed by the Ninth International Symposium on Radionuclides in Nephrourology in 1994.

RESULTS

The final document was produced and addressed: objectives, equipment, data acquisition, choice of radiopharmaceutical, patient preparation, position, dosage of furosemide, timing of furosemide, role of bladder catheter, duration of study, pediatric considerations, evaluation of the furosemide response, interpretation, and conclusion.

CONCLUSION

The report presents a standardized approach to diuresis renography that, if adopted, will improve reproducibility between centers, discourage unacceptable practice and stimulate further discussion between nuclear medicine and urology health care professionals who treat patients with dilated and obstructed upper urinary tracts.

Alcohol content of proprietary mouthwashes

The use of mouthwashes with high ethanol content has been linked to excess risks of mouth cancer, as have prolonged and frequent use of mouthwashes with lower ethanol contents. Twenty two proprietary mouthwashes available without prescription in Ireland were analysed by gas chromatography and their ethanol contents (w/v) at manufacturers' recommended dilutions for use were calculated. The ethanol contents of diluted mouthwashes ranged from < 0.01-23.40% w/v. 27% had ethanol contents > 10% w/v; 9% had ethanol contents > 20% w/v. As the use of the higher ethanol content mouthwashes may be a possible risk factor for oral cancer in frequent or constant users, we believe that the attention of the statutory regulatory authorities should be drawn to this situation.

Productive aging: an overview of the literature

"Productive aging" describes an array of activities through which older people contribute to society. Both the extent of current productive activities among older people and the barriers to more extensive productive activity are reviewed. If certain adjustments can be made for their special needs, older people have the potential to make substantial contributions. However, a variety of prejudicial attitudes and discriminatory practices continue to limit the opportunities of older people to make productive contributions, particularly in workplace settings. Interventions are needed to strengthen opportunities for retraining, employment, and volunteering for older people. At the same time, programs and policies to facilitate the productive participation of older people cannot easily correct for the adverse effects of a lifetime of racial or gender discrimination.

Fluctuations in body satisfaction across situations

Although the variable nature of body image was underscored by Schilder (The image and appearance of the human body. New York: International Universities Press, 1950), few investigators have addressed the stability of body image or its sensitivity to variation in environmental or situational conditions. Most researchers have assumed that body image is a stable characteristic. The present study was designed to investigate the situational specificity of body satisfaction, one facet of body image. One hundred forty-four undergraduate women indicated their degree of body satisfaction in general and in the following four situations: (a) walking by a group of attractive men and women at the beach in a bathing suit, (b) having a conversation with a close female friend over lunch, (c) getting dressed to go to school in privacy, and (d) trying on bathing suits in the dressing room of a department store. Body satisfaction varied significantly across the four situations for all body parts except the face, hair, and hands. Additionally, body satisfaction scores were found to reflect how subjects felt about their bodies when they were being especially self-critical, rather than how they felt in "everyday" situations.

Predation of simulated willow ptarmigan nests: the influence of density and cover on spatial and temporal patterns of predation

Predation of eggs is a major loss in production for many populations of grouse, yet often the identity of the predators, their pattern of search, and their impact on spacing of nests is unknown. We set out clutches of quail eggs to simulate willow ptarmigan (Lagopus lagopus) nests at three densities (100/km2, 50/km2, and 27/km2) to (i) investigate the effects of nest density and concealment on predation rates, (ii) investigate the temporal and spatial patterns of predation, (iii) identify nest predators, and (iv) compare predation rates on artificial nests and nests of willow ptarmigan. Predation on artificial nests was not dependent on density. Predation was lowest in the 1st week, when nests were covered to simulate conditions during laying, and increased in week 2. Thereafter it increased on two plots and declined on four others. Artificial nests had a higher probability of being taken by a predator if they were adjacent to a nest that had been taken previously, suggesting that predators concentrate their search in areas where they have been successful. Neither amount of cover at the nest nor distance to marker stakes influenced predation rate. Predation on artificial nests was lower than on ptarmigan nests. Red foxes (Vulpes vulpes) took most clutches at artificial nests positioned beside boards coated with petroleum jelly, followed by Arctic ground squirrels (Spermophilus parryi), and least weasels (Mustela nivalis). Artificial nests were useful for identifying potential nest predators and investigating their search patterns, but did not give a good index of the extent or temporal pattern of predation on natural nests.

Role of support networks in maintenance of improved cardiovascular health status

This study was undertaken to clarify the relationship between maintaining an improved cardiovascular health status and social support networks. Two hundred and ninety participants from a national trial that was carried out to specify the impact of reducing risk for cardiovascular disease were rescreened 3 years after completion of the trial. Original risk status of the participants was compared to risk status at the end to identify who had an improved risk status (n = 204). Risk status of 204 improvers was calculated from the rescreening data to identify maintainers (n = 63) and nonmaintainers (n = 143). No significant differences were found between maintainers and nonmaintainers in sociodemographic status, or in level of general support. Highly significant differences were found for four types of support provided specifically for risk reduction: information/advice (P = 0.002), appraisal (P = 0.004), emotional support (P = 0.01) and availability (P = 0.019). Most of these differences in support were accounted for by the larger support network identified by the maintainers. In addition, compared to nonmaintainers, maintainers' networks were more family-centered (P = 0.012), and were correspondingly more dense (P = 0.021). A discriminant function analysis using the significant variables was able to predict maintenance in 72% of the cases. The significant variables also accounted for 10% of the variance between maintainers and nonmaintainers. The implications of this study are: (1) assessment of support should be specific to the health outcome being studied: (2) research on the impact of social environment on health status will benefit from clearly specifying individual components of social support and social networks; (3) amount of social support provided is related to size of the network and relationship of supporter to the at-risk individual; (4) because social support and social networks account for a small but significant amount of the variance between maintainers and nonmaintainers, these concepts should be included in patient assessments prior to developing a treatment or maintenance plan.

Methodological issues in social support and social network research

With the plethora of articles describing a relationship between social support and/or social network and health status, it was considered useful to take stock of the current status of research in this area, focusing on two critical methodological issues: clarity of definition, and validity and reliability of the measurement instruments. Of the 33 instruments reviewed only modest agreement was found in conceptual definition, and frequently the concepts were not defined or ill-defined. Of particular concern is the definitional confusion between social support and social network. Variables used to operationalize these concepts confirm this lack of specificity and ambiguity in definition. As for validity and reliability, many of the investigators reported no data on these issues; others provided information that only modestly supported the validity or reliability of their instrument. The conclusion of this assessment suggests the need to clarify the essential elements of social support and social networks in order to better distinguish between the behavioral (support) and structural (network) variables that may be affecting health status. A question is also raised as to the likelihood of a single questionnaire being designed that would accurately measure the perceptions of support or supportive behaviors in the variety of supportive research that will continue to be studied. Finally, more rigorous standards need to be used by investigators in establishing the validity and reliability of the instruments in order to improve their predictive utility.

Expressed emotion and perceived family interaction in the key relatives of elderly patients with dementia

Four groups of families were investigated using an interview designed to assess expressed emotion (EE) in relatives of psychiatric patients and a family interaction questionnaire (FIQ) based upon the Leary and Benjamin schemes for coding interpersonal behaviour. The families included 25 containing a psychiatric patient aged between 18 and 46, and three groups of 12 families each, all containing a patient over 60 (patients with dementia, a functional psychiatric disorder, or a chronic physical disorder respectively). In all cases data were obtained from key relatives. The FIQ clearly separated out the group of dementia relatives who reported the most dominant and protective behaviours and the highest levels of hostile-dominance and the lowest levels of affection. EE was not found to be so sensitive to interactions occurring in families with a member with dementia, and the possible reasons for this are discussed.