Core content for venous and Lymphatic Medicine: 2022 revision

The core content for a medical specialty outlines the scope of the discipline as well as the categories of knowledge considered essential to practice in the field. It provides a template for the development of curricula for medical school, graduate, and postgraduate education, as well as for creating certification standards. Venous and Lymphatic Medicine (VLM) is a specialty that has benefitted from contributions from specialists from several medical disciplines. Optimally, the societies, boards, and residency review committees representing these disciplines would uniformly recognize the scope of VLM to develop education and assessment standards to allow training and identification of qualified practitioners. In order to inform the standard setting bodies and other stakeholders of the current scope of VLM, a task force of VLM experts from cardiology, dermatology, emergency medicine, general surgery, interventional radiology, vascular medicine, and vascular surgery was formed to revise a 2014 consensus document defining the core content of the specialty of VLM.

Relationships between job burnout, ethical climate and organizational citizenship behaviour among registered nurses: A cross-sectional study

AIM

This study aimed to investigate the levels of nurses' organizational citizenship behaviour and the associations between job burnout and ethical climate with organizational citizenship behaviour.

BACKGROUND

Organizational citizenship behaviour improves adverse outcomes led by nursing shortage. However, the associations between three dimensions of job burnout and organizational citizenship behaviour are inconsistent, and little is known about whether ethical climate is related to organizational citizenship behaviour in nurses.

METHODS

In this cross-sectional study, 1157 nurses were selected using convenience sampling from April to October 2019. Self-report surveys assessed nurses' organizational citizenship behaviour, emotional exhaustion, depersonalization, personal accomplishment and perceptions of ethical climate.

RESULTS

Mean organizational citizenship behaviour was high among nurses. The regression model showed that job burnout and ethical climate explained an additional 38.6% of the variance in organizational citizenship behaviour over and above sociodemographic factors, with 44.9% of the total variance.

CONCLUSION

Nurses' organizational citizenship behaviour was at a relatively high level. Depersonalization was negatively associated with organizational citizenship behaviour while personal accomplishment and ethical climate were positively related to organizational citizenship behaviour. Therefore, nurse leaders are encouraged to take measures to help nurses reduce job burnout and create a favourable ethical climate for increasing nurses' organizational citizenship behaviour.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The 2016 ENFSI Fingerprint Working Group testing programme

In 2016, the Fingerprint Working Group (EFP-WG) of the European Network of Forensic Science Institutes (ENFSI), officially established an advisory group with the task of organising proficiency tests (PTs), as well as collaborative exercises (CEs) as a way of raising standards within the fingerprint profession. This article will provide an overview of the Visualisation collaborative exercise and the Comparison proficiency test, which were carried out in 2016. Both the exercise and the test were organised and co-funded by the Prevention of and Fight against Crime Programme of the European Union [1-3], Direct Grant "Towards the Vision for European Forensic Science 2020 (TVEFS-2020)" HOME/2013/ISEC/MO/ENFSI/4000005962, work package T3 "Proficiency Tests and Collaborative Exercises for the Fingerprint Domain". The characteristics of the testing programme are summarised, followed by an overview of the knowledge that has been gained, including lessons learnt.

Dental radiographic findings in 18 individuals with SATB2-associated syndrome

OBJECTIVE

To characterize the radiographic dental phenotype of individuals with SATB2-associated syndrome (SAS).

MATERIALS AND METHODS

Participants were evaluated by a multidisciplinary team during a concurrent clinic conducted during the 1st international SAS family meeting held in 2017 at a single institution. Whenever possible, panoramic and/or periapical radiographs were obtained in clinic or previously obtained and provided by the caregiver.

RESULTS

Of the 37 individuals evaluated, 18 (12 males, median age 8.5 years) underwent radiographic examination. Dental radiographs revealed anomalies in all individuals starting at 2 years of age. The most consistent finding was delayed development of the mandibular second bicuspids (83%) with other common radiographic findings including delayed development of the roots of the permanent teeth (78%), severely rotated (56%) or malformed teeth (44%), and taurodontism (44%).

CONCLUSIONS

Dental anomalies are fully penetrant and can be documented radiographically in all individuals with SAS.

CLINICAL RELEVANCE

Dental radiographic findings of delayed second premolar development and delayed development of permanent root formation, especially concurrent with findings of taurodontism and malformed teeth, support a clinical suspicion for SAS and should help differentiate SAS from other neurodevelopmental syndromes.

Integrated imaging of [11C]-PBR28 PET, MR diffusion and magnetic resonance spectroscopy 1H-MRS in amyotrophic lateral sclerosis

Objective

To determine the relationship between brain tissue metabolites measured by in vivo magnetic resonance spectroscopy (¹H-MRS), and glial activation assessed with [¹¹C]-PBR28 uptake in people with amyotrophic lateral sclerosis (ALS).

Methods

Forty ALS participants were evaluated clinically using the revised ALS functional rating scale (ALSFRS-R) and upper motor neuron burden (UMNB). All participants underwent simultaneous brain [¹¹C]-PBR28 PET and MR imaging including diffusion tensor imaging to acquire fractional anisotropy (FA). [¹¹C]-PBR28 uptake was measured as standardized uptake values normalized by whole brain mean (SUVR). ¹H-MRS metabolite ratios (myo-inositol/creatine, mI/Cr; N-acetylaspartate/creatine, NAA/Cr) were measured within the precentral gyri and brain stem (regions known to be involved in ALS pathophysiology), and precuneus (which served as a control region). Whole brain voxel-wise correlation analyses were employed to identify brain regions exhibiting an association between metabolites within the VOIs and [¹¹C]-PBR28 uptake.

Results

In the precentral gyri, [¹¹C]-PBR28 uptake correlated positively with mI/Cr and negatively with NAA/Cr. The same correlations were not statistically significant in the brain stem, or in the control precuneus region. Whole brain voxel-wise correlation analyses between the estimated brain metabolites within the VOIs and SUVR were highly correlated in the precentral gyri. Decreased FA values in the precentral gyri were correlated with reduced NAA/Cr and elevated mI/Cr. Higher UMNB was correlated with increased [¹¹C]-PBR28 uptake and mI/Cr, and decreased NAA/Cr. ALSFRS-R total score correlated positively with NAA/Cr and negatively with mI/Cr.

Conclusion

Integrated PET-MR and ¹H-MRS imaging demonstrates associations between markers for neuronal integrity and neuroinflammation and may provide valuable insights into disease mechanisms in ALS.

•

This study evaluates the relationship between ¹H-MRS and [¹¹C]-PBR28 PET-MR measures in people with ALS.

•

Myo-inositol/Creatine correlates positively with glial activation measured by [¹¹C]-PBR28 PET, and negatively with fractional anisotropy.

•

N-acetyl-aspartate/Creatine correlates negatively with [¹¹C]-PBR28 PET, and positively with fractional anisotropy.

•

Myo-inositol/Creatine and N-acetyl-aspartate/Creatine correlate with ALS-functional rating scale and upper motor neuron burden.

•

¹H-MRS and PET-MR measures provide complementary information to better understand brain pathology in people with ALS.

The 2015 ENFSI Fingerprint Working Group testing programme

As early as 2004, the Fingerprint Working Group (EFP-WG) of the European Network of Forensic Science Institutes (ENFSI) has organised proficiency tests (PT's), as well as collaborative exercises (CE's), as a way of raising standards within the fingerprint profession. This article provides an overview of the three collaborative exercises carried out in 2015. The characteristics of the testing programme are summarised, followed by an overview of the knowledge that has been gained, including depicting what lessons have been learnt.

Exploring lesbian, gay and bisexual patients' accounts of their experiences of cancer care in the UK

Despite greater recognition of rights and responsibilities around the care of cancer patients who identify as lesbian, gay or bisexual (LGB) within healthcare systems in the United Kingdom, recent quantitative evidence suggests that they experience poorer care than heterosexual counterparts and qualitative findings are limited. Therefore, in the present study, we present an analysis of the accounts of fifteen British LGB cancer patients (diagnosed with different forms of the disease) of the care received. Data were collected through in-depth individual interviews and analysed using thematic analysis. Three of the emerging themes are discussed. These include an examination of what we conceptualise as the 'awkward choreography around disclosure' opportunities and dilemmas for LGB patients, we describe 'making sense of sub-optimal care' which included instances of overt discrimination but was more frequently manifested through micro-aggressions and heteronormative systems and practices, and explore accounts of 'alienation from usual psychosocial cancer support'. We employ Meyer's Minority Stress Theory (2003) as a lens to interrogate the data and explore the ways in which actual or anticipated prejudice affected their experiences of treatment and support. We close with recommendations to enhance LGB-affirmative cancer care including enhanced training of healthcare professionals and explicit articulation of institutional commitment to LGB equality.

Further supporting evidence for the SATB2-associated syndrome found through whole exome sequencing

The SATB2-associated syndrome (SAS) was recently proposed as a clinically recognizable syndrome that results from deleterious alterations of the SATB2 gene in humans. Although interstitial deletions at 2q33 encompassing SATB2, either alone or contiguously with other genes, have been reported before, there is limited literature regarding intragenic mutations of this gene and the resulting phenotype. We describe five patients in whom whole exome sequencing identified five unique de novo mutations in the SATB2 gene (one splice site, one frameshift, and three nonsense mutations). The five patients had overlapping features that support the characteristic features of the SAS: intellectual disability with limited speech development and craniofacial abnormalities including cleft palate, dysmorphic features, and dental abnormalities. Furthermore, Patient 1 also had features not previously described that represent an expansion of the phenotype. Osteopenia was seen in two of the patients, suggesting that this finding could be added to the list of distinctive findings. We provide supporting evidence that analysis for deletions or point mutations in SATB2 should be considered in children with intellectual disability and severely impaired speech, cleft or high palate, teeth abnormalities, and osteopenia.

Lights, camera…citizen science: assessing the effectiveness of smartphone-based video training in invasive plant identification

The rapid growth and increasing popularity of smartphone technology is putting sophisticated data-collection tools in the hands of more and more citizens. This has exciting implications for the expanding field of citizen science. With smartphone-based applications (apps), it is now increasingly practical to remotely acquire high quality citizen-submitted data at a fraction of the cost of a traditional study. Yet, one impediment to citizen science projects is the question of how to train participants. The traditional “in-person” training model, while effective, can be cost prohibitive as the spatial scale of a project increases. To explore possible solutions, we analyze three training models: 1) in-person, 2) app-based video, and 3) app-based text/images in the context of invasive plant identification in Massachusetts. Encouragingly, we find that participants who received video training were as successful at invasive plant identification as those trained in-person, while those receiving just text/images were less successful. This finding has implications for a variety of citizen science projects that need alternative methods to effectively train participants when in-person training is impractical.

Using video ratings to assess multitasking performance in a naturalistic paradigm

BACKGROUND

Multitasking measures, in which a series of tasks must be completed within a naturalistic setting not fully under the experimenter's control, have been shown to be more sensitive than traditional measures in detecting organisational problems in people with difficulties in executive functioning. There are a number of drawbacks to such tasks however. They can take considerable time to administer and are demanding in terms of examiners noting and recording all relevant aspects of performance. This potentially leaves them more open to subtle bias. One method that could offset these limitations is to video record performance.

OBJECTIVES

The practicality and outcome of using video ratings to accurately score performance off-line is investigated here.

METHODS

Nineteen participants completed a Multiple Errands Task (MET) while wearing a body-worn camera. Their performance was scored "live" and by an independent rater who had only access to video footage of the task.

RESULTS

Significant relationships were seen on all variables of the MET between the live and video ratings. The inter-rater reliability of the measure appears strong.

CONCLUSION

We provide initial support for the use of a video rater when assessing performance on an MET.

Minimally invasive therapy for fetal sacrococcygeal teratoma: case series and systematic review of the literature

OBJECTIVE

Large solid sacrococcygeal teratomas (SCT) can cause high-output cardiac failure and fetal or neonatal death. The aim of this study was to describe the outcomes of minimally invasive antenatal procedures for the treatment of fetal SCT.

METHODS

A case review was performed of five fetuses with a large SCT treated antenatally using minimally invasive techniques, and a systematic literature review on fetal therapy for solid SCTs was carried out.

RESULTS

Five women were referred between 17 + 5 and 26 + 4 weeks' gestation for a large fetal SCT with evidence of fetal cardiac failure. Vascular flow to the tumors was interrupted by fetoscopic laser ablation (n = 1), radiofrequency ablation (RFA; n = 2) or interstitial laser ablation  ±  vascular coiling (n = 2). There were two intrauterine fetal deaths. The other three cases resulted in preterm labor within 10 days of surgery. One neonate died. Two survived without procedure-related complications but had long-term morbidity related to prematurity. The systematic literature review revealed 16 SCTs treated minimally invasively for (early) hydrops. Including our cases, six of 20 hydropic fetuses survived after minimally invasive therapy (30%). Survival after RFA or interstitial laser ablation was 45% (5/11). Of 12 fetuses treated for SCT without obvious hydrops and for which perinatal survival data were available, eight (67%) survived. Mean gestational age at delivery after minimally invasive therapy was 29.7 ± 4.0 weeks. Survival after open fetal surgery in hydropic fetuses was 6/11 (55%), with a mean gestational age at delivery of 29.8 ± 2.9 weeks.

CONCLUSIONS

Fetal therapy can potentially improve perinatal outcomes for hydropic fetuses with a solid SCT, but is often complicated by intrauterine death and preterm birth.

Left-right asymmetry of the gnathostome skull: its evolutionary, developmental, and functional aspects

Much of the gnathostome (jawed vertebrate) evolutionary radiation was dependent on the ability to sense and interpret the environment and subsequently act upon this information through utilization of a specialized mode of feeding involving the jaws. While the gnathostome skull, reflective of the vertebrate baüplan, typically is bilaterally symmetric with right (dextral) and left (sinistral) halves essentially representing mirror images along the midline, both adaptive and abnormal asymmetries have appeared. Herein we provide a basic primer on studies of the asymmetric development of the gnathostome skull, touching briefly on asymmetry as a field of study, then describing the nature of cranial development and finally underscoring evolutionary and functional aspects of left-right asymmetric cephalic development.

Pattern and polarity in the development and evolution of the gnathostome jaw: both conservation and heterotopy in the branchial arches of the shark, Scyliorhinus canicula

The acquisition of jaws constitutes a landmark event in vertebrate evolution, one that in large part potentiated their success and diversification. Jaw development and patterning involves an intricate spatiotemporal series of reciprocal inductive and responsive interactions between the cephalic epithelia and the cranial neural crest (CNC) and cephalic mesodermal mesenchyme. The coordinated regulation of these interactions is critical for both the ontogenetic registration of the jaws and the evolutionary elaboration of variable jaw morphologies and designs. Current models of jaw development and evolution have been built on molecular and cellular evidence gathered mostly in amniotes such as mice, chicks and humans, and augmented by a much smaller body of work on the zebrafish. These have been partnered by essential work attempting to understand the origins of jaws that has focused on the jawless lamprey. Chondrichthyans (cartilaginous fish) are the most distant group to amniotes within extant gnathostomes, and comprise the crucial clade uniting amniotes and agnathans; yet despite their critical phylogenetic position, evidence of the molecular and cellular underpinnings of jaw development in chondrichthyans is still lacking. Recent advances in genome and molecular developmental biology of the lesser spotted dogfish shark, Scyliorhinus canicula, make it ideal for the molecular study of chondrichthyan jaw development. Here, following the 'Hinge and Caps' model of jaw development, we have investigated evidence of heterotopic (relative changes in position) and heterochronic (relative changes in timing) shifts in gene expression, relative to amniotes, in the jaw primordia of S. canicula embryos. We demonstrate the presence of clear proximo-distal polarity in gene expression patterns in the shark embryo, thus establishing a baseline molecular baüplan for branchial arch-derived jaw development and further validating the utility of the 'Hinge and Caps' model in comparative studies of jaw development and evolution. Moreover, we correlate gene expression patterns with the absence of a lambdoidal junction (formed where the maxillary first arch meets the frontonasal processes) in chondrichthyans, further highlighting the importance of this region for the development and evolution of jaw structure in advanced gnathostomes.

The Ribosomal Database Project: improved alignments and new tools for rRNA analysis

The Ribosomal Database Project (RDP) provides researchers with quality-controlled bacterial and archaeal small subunit rRNA alignments and analysis tools. An improved alignment strategy uses the Infernal secondary structure aware aligner to provide a more consistent higher quality alignment and faster processing of user sequences. Substantial new analysis features include a new Pyrosequencing Pipeline that provides tools to support analysis of ultra high-throughput rRNA sequencing data. This pipeline offers a collection of tools that automate the data processing and simplify the computationally intensive analysis of large sequencing libraries. In addition, a new Taxomatic visualization tool allows rapid visualization of taxonomic inconsistencies and suggests corrections, and a new class Assignment Generator provides instructors with a lesson plan and individualized teaching materials. Details about RDP data and analytical functions can be found at http://rdp.cme.msu.edu/.

Compensatory strategies for acquired disorders of memory and planning: differential effects of a paging system for patients with brain injury of traumatic versus cerebrovascular aetiology

BACKGROUND

Previous studies have demonstrated the effectiveness of paging systems in compensating for everyday memory and planning problems after brain injury, including in individuals with traumatic brain injury (TBI).

METHODS

Here, in addition to further analyses of the TBI data from a previous randomised control crossover trial, results are reported from a sub-group of 36 participants with brain injury from cerebrovascular accident (CVA).

RESULTS

Results indicate that, as with the TBI group, the pager was effective. However, the pattern of results following cessation of treatment differed. At a group level, TBI participants demonstrated maintenance of pager-related benefits, whereas CVA participants' performance returned to baseline levels. Comparisons of demographic and neuropsychological characteristics of the groups showed that the CVA group was older, had a shorter interval post-injury, and had poorer executive function than the TBI group. Furthermore, within the TBI group, maintenance was associated with executive functioning, such that executive dysfunction impeded maintenance. This correlation remained after controlling for demographic differences between groups.

CONCLUSIONS

Together, these findings suggest that executive dysfunction may affect treatment-for example, whether or not temporary use of the pager is sufficient to establish a subsequently self-sustaining routine.

Estimating Ownerships and Parcels of Nonindustrial Private Forestland in Massachusetts

Woodland ownership for three regions of Massachusetts is estimated using property tax assessor data. These data are nonspatially explicit and are based on commercial, industrial, residential, or other activity rather than actual land cover. A heuristic was used to aggregate similar parcels to provide an estimate of actual landownership. The estimated average statewide ownership is 17.9 ac, and when properties less than 10 ac are excluded, the average rises to 42.5 ac. The median ownership varies from east to west in the state across the spectrum of suburban development radiating from the metropolitan Boston area, with the median being 4.8, 7.8, and 8.6 ac in the eastern, central, and western part of the state, respectively. These results are compared with ownership estimates generated by the US Forest Service Forest Inventory and Analysis.

Factor I is required for the development of membranoproliferative glomerulonephritis in factor H-deficient mice

The inflammatory kidney disease membranoproliferative glomerulonephritis type II (MPGN2) is associated with dysregulation of the alternative pathway of complement activation. MPGN2 is characterized by the presence of complement C3 along the glomerular basement membrane (GBM). Spontaneous activation of C3 through the alternative pathway is regulated by 2 plasma proteins, factor H and factor I. Deficiency of either of these regulators results in uncontrolled C3 activation, although the breakdown of activated C3 is dependent on factor I. Deficiency of factor H, but not factor I, is associated with MPGN2 in humans, pigs, and mice. To explain this discordance, mice with single or combined deficiencies of these factors were studied. MPGN2 did not develop in mice with combined factor H and I deficiency or in mice deficient in factor I alone. However, administration of a source of factor I to mice with combined factor H and factor I deficiency triggered both activated C3 fragments in plasma and GBM C3 deposition. Mouse renal transplant studies demonstrated that C3 deposited along the GBM was derived from plasma. Together, these findings provide what we believe to be the first evidence that factor I-mediated generation of activated C3 fragments in the circulation is a critical determinant for the development of MPGN2 associated with factor H deficiency.

Discovery of a major D-loop replication origin reveals two modes of human mtDNA synthesis

Mammalian mitochondrial DNA (mtDNA) replication has long been considered to occur by asymmetric synthesis of the two strands, starting at the multiple origins of the strand-displacement loop (D-loop). We report the discovery of a major replication origin at position 57 in the D-loop of several human cell lines (HeLa, A549, and 143B.TK-) and immortalized lymphocytes. The nascent chains starting at this origin, in contrast to those initiated at the previously described origins, do not terminate prematurely at the 3' end of the D-loop but proceed well beyond this control point, behaving as "true" replicating strands. This origin is mainly responsible for mtDNA maintenance under steady-state conditions, whereas mtDNA synthesis from the formerly identified D-loop origins may be more important for recovery after mtDNA depletion and for accelerating mtDNA replication in response to physiological demands.

Strikingly higher frequency in centenarians and twins of mtDNA mutation causing remodeling of replication origin in leukocytes

The presence of a genetic component in longevity is well known. Here, the association of a mtDNA mutation with a prolonged life span in humans was investigated. Large-scale screening of the mtDNA main control region in leukocytes from subjects of an Italian population revealed a homoplasmic C150T transition near an origin of heavy mtDNA-strand synthesis in approximately 17% of 52 subjects 99-106 years old, but, in contrast, in only 3.4% of 117 younger individuals (P = 0.0035). Evidence was obtained for the contribution of somatic events, under probable nuclear genetic control, to the striking selective accumulation of the mutation in centenarians. In another study, among leukocyte mtDNA samples from 20 monozygotic and 18 dizygotic twins, 60-75 years old, 30% (P = 0.0007) and 22% (P = 0.011), respectively, of the individuals involved exhibited the homoplasmic C150T mutation. In a different system, i.e., in five human fibroblast longitudinal studies, convincing evidence for the aging-related somatic expansion of the C150T mutation, up to homoplasmy, was obtained. Most significantly, 5' end analysis of nascent heavy mtDNA strands consistently revealed a new replication origin at position 149, substituting for that at 151, only in C150T mutation-carrying samples of fibroblasts or immortalized lymphocytes. Considering the aging-related health risks that the centenarians have survived and the developmental risks of twin gestations, it is proposed that selection for a remodeled replication origin, inherited or somatically acquired, provides a survival advantage and underlies the observed high incidence of the C150T mutation in centenarians and twins.

Understanding lesbians' healthcare behaviour: the case of breast self-examination

Lesbians' risk of breast cancer is a much-debated issue in health research because lesbians are believed to be at higher risk of the disease than are heterosexual women. This belief is based upon particular risk factors for breast cancer, which are said to be more prevalent in lesbians; and upon differences in preventive health behaviours: in particular, lesbians are said to be less likely to practise breast self-examination (BSE). This paper presents data collected as part of the UK Lesbians and Healthcare Survey (n = 1066) focusing on lesbians who report never practising BSE (n = 218, 20%) and the explanations they offer for their healthcare behaviours. It identifies six types of explanation for not practising BSE: (i) "I don't know what I'm looking for"; (ii) "I've never got into the habit"; (iii) "I'm frightened in case I find something"; (iv) "I don't think I'm at much risk"; (v) "I'm uncomfortable with my body"; and (vi) "My partner does it for me". These findings are important for increasing understanding of lesbians' healthcare behaviour and for developing health promotion materials relevant to their needs.

Electrical heterogeneity within the ventricular wall

Recent studies have established the presence of three distinct cell types in the ventricular myocardium: epicardial, M and endocardial cells. Epicardial and M cell action potentials differ from endocardial cells with respect to the morphology of phase 1. These cells possess a prominent transient outward current (I(to))-mediated notch responsible for the 'spike and dome' morphology of the epicardial and M cell response. M cells are distinguished from the other cell types in that they display a smaller slowly activating delayed rectifier current (I(Ks)), but a larger late sodium current (late I(Na)) and sodium-calcium exchange current (I(Na-Ca)). These ionic distinctions underlie the longer action potential duration (APD) and steeper APD-rate relationship of the M cell, which is more pronounced in the presence of antiarrhythmic agents with class III actions. The preferential prolongation of the M cell action potential results in the development of a transmural dispersion of repolarization (TDR), which can be estimated from the electrocardiogram (ECG) as the interval between the peak and the end of the T wave (QTpeak-QTend interval). Using the canine arterially perfused ventricular wedge model, transmembrane action potentials of the various cardiac cell types can be correlated to the waveforms of the ECG, providing insight into the cellular etiology of ECG abnormalities. Two congenital syndromes of sudden cardiac death that have been modeled using this technique are the long QT and Brugada syndromes. The long QT syndrome has been linked to 5 gene mutations on chromosomes 3, 7, 11, and 21. Mutations in the cardiac sodium channel SCN5A have been linked to families with a history of the Brugada syndrome. Although the etiologies of these two syndromes are different, lethal arrhythmias in both are thought to arise due to amplification of intrinsic electrical heterogeneities. Similar mechanisms are likely responsible for life-threatening arrhythmias in a variety of other cardiomyopathies ranging from heart failure and hypertrophy, which involve mechanisms similar to those operative in LQTS, to ischemia and infarction, which may involve mechanisms more closely resembling those responsible for the Brugada syndrome.

Estrogen receptors in the normal adult and developing human inner ear and in Turner's syndrome

The influence of estrogens, the female sex hormone, on the ear and hearing is yet not fully investigated, though some studies have suggested that estrogens may influence hearing functions. The presence of estrogen receptors alpha and beta has earlier been shown in the inner ear of mice and rats. The aim of this study was to map possible estrogen receptors in the human inner ear. Inner ear tissue from human adults, aborted human normal fetuses and fetuses with Turner's syndrome were collected. Paraffin embedded sections of adult and fetal inner ears were immunostained with antibodies against estrogen receptors alpha and beta. Estrogen receptor alpha containing cells were found in the adult human inner ear only in the spiral ganglion, and estrogen receptor beta in the stria vascularis solely. The human fetal inner ear tissue from both normal and Turner fetuses showed a very weak staining of estrogen receptor alpha in the spiral ganglion cells, but no specific labeling of the Kölliker's organ of Corti at 13, 14 and 18 weeks of age. No staining of estrogen receptor beta was seen in the fetal inner ear.