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.

"Does the use of gestation-specific centiles for cervical length change the management of pregnancies at risk of recurrent spontaneous preterm birth?"

INTRODUCTION

Preterm birth is the leading cause of neonatal morbidity and mortality. Spontaneous Preterm Birth (sPTB) has many and varied causes but is known to be strongly associated with a short or shortening cervix in the midtrimester of pregnancy. The strongest risk factor for sPTB is a previous sPTB. In women with a history of sPTB, we can offer surveillance and treatments which have been proven to reduce the risk of sPTB, such as cervical cerclage and vaginal progesterone supplementation. Alongside other indications, we currently use 25 mm or shorter as a "trigger threshold" for offering cervical cerclage treatment in the Preterm Birth Prevention Clinic at The National Maternity Hospital.

AIM

To determine if using gestation-specific centiles instead of a 25 mm cut-off for cervical length changes the antenatal management of women at high risk of sPTB.

METHOD

This was a retrospective chart review of all women attending the preterm birth clinic over the 2-year period 2018-2020 in a large tertiary referral unit in Dublin, Ireland. Demographic details, obstetric history, preterm birth risk factors and preventative treatments offered were collected and analysed. Cervical lengths were measured with ultrasound using a standardised protocol and all performed or supervised by 2 experienced sonographers.

RESULTS

A total of 200 patients with known risk factors for sPTB attended the Preterm Birth Surveillance Clinic at the National Maternity Hospital during the study period. Of these, 36/200 (18%) went on to deliver again prior to 37 weeks despite attending the clinic +/- receiving interventions & this group are the focus of this paper. The indications for surveillance in this group that had a recurrent sPTB included recurrent second-trimester pregnancy losses/preterm delivery < 34 weeks (26/36 (72%)), cervical trauma (including treatment of CIN) (12/36 (33%)), congenital abnormalities (1/36 (2.8%)), uterine anomaly (1/36 (2.8%)) and placental bleeding (1/36 (2.8%)). There was one smoker in this series. Funnelling was observed in 3/36 cases (8.3%). Of the 36 patients, an additional 15 would have received a cerclage had gestation-specific centiles, i.e., <5th centile, been used and an additional 10/36 (28%) would have been offered progesterone therapy.

CONCLUSION

In those at high risk of preterm birth, the use of gestation-specific centiles for cervical length increases the proportion of patients that would be eligible for cervical cerclage. It is unclear whether this would change clinical outcome.

Enhanced Recovery After Bariatric Surgery: Feasibility and Outcomes in a National Bariatric Centre

PURPOSE

This study aimed to assess outcomes of bariatric surgical procedures after the implementation of an enhanced recovery after bariatric surgery protocol in the National Bariatric Centre in Ireland.

MATERIALS AND METHODS

Data on consecutive bariatric procedures performed over a 36-month period was prospectively recorded. ERABS interventions utilized included preoperative counselling, shortened preoperative fasts, specific anaesthetic protocols, early postop mobilization and feeding, and extended post-discharge thromboprophylaxis.

RESULTS

A total of 280 primary bariatric procedures were performed over a 36-month period. The primary procedures were laparoscopic sleeve gastrectomy (57.5%), laparoscopic one anastomosis gastric bypass (33.2%) and laparoscopic Roux-en-Y gastric bypass (9.3%). Mean (SD) age was 48 (± 10) years, mean (SD) preoperative BMI 49.5 (± 9) kg/m² and 68% were female. Median ASA score was 3, and median OSMRS also 3. Over 50% of patients had a diagnosis of hypertension or OSA, and over one-third had a diagnosis of type 2 diabetes mellitus or dyslipidemia. All procedures were completed laparoscopically and 29 patients underwent a simultaneous procedure. The mean (SD) length of stay was 2.3 (± 1.4) days (median 2 days, range 2-47 days). Overall postoperative morbidity rate was 10.0% (n = 29). The 30-day readmission and reoperation rates were 3.6% and 2.5% respectively. There was no mortality recorded in this series.

CONCLUSION

Implementing an ERABS protocol was feasible, safe, associated with low morbidity, no mortality, acceptable LOS and low readmission and reoperation rates. Although patients with obesity have a spectrum of disease-related complications, this should not preclude the use of an ERABS protocol in bariatric surgery.

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.

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.

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.

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.

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.

Continuing medical education: 1960s to the present

Since the 1960s, continuing medical education (CME) has undergone a period of reappraisal of its effectiveness and consideration of alternatives to the traditional teaching model. In this paper the authors discuss three proposals that were developed out of these concerns: the establishment of a national plan, a process program model based on the identified needs of physicians, and the use of mandatory continuing education as part of a relicensing/recertification procedure. The problems and controversies in each of these areas are explored. Recommendations for changes in CME are discussed and summarized into three areas: organizational needs, programmatic needs, and physician needs. The authors attempt to point out the general agreement in these recommendations as well as the difficulty of achieving any uniform or orderly change in the future.