Clinical characteristics of functioning gonadotroph adenoma in women presenting with ovarian hyperstimulation: Audit of UK pituitary centres.

OBJECTIVE: Functioning gonadotroph adenomas (FGAs) are rare pituitary tumours stimulating ovarian function with potential life-threatening consequences in women. However, a lack of aggregated clinical experience of FGAs impairs management in affected women. The aim of this study is to present the clinical course of FGA-induced ovarian hyperstimulation syndrome (OHSS) cases as identified by some of the largest UK pituitary endocrine tertiary centres with a view to increasing awareness and improving diagnosis and management of women with FGA. DESIGN: A retrospective observational study; audit of eight UK regional pituitary centres for cases of FGAs. SETTING: Specialist neuroendocrine centres in the United Kingdom. PATIENTS AND MEASUREMENTS: Women diagnosed with FGA-induced OHSS. Description of their clinical course. RESULTS: Seven cases of FGA were identified in women, all causing OHSS. Mean age was 33.4 years at diagnosis. Abdominal pain, irregular periods, headache, and visual disturbances were reported at presentation by 100%, 71%, 57% and 43% of women, respectively. Three of seven women underwent ovarian surgery before FGA diagnosis. Six women underwent transsphenoidal surgery (TSS) with incomplete tumour resection in five of those, but all showed improvement or resolution in symptoms and biochemistry postoperatively. CONCLUSION: FGA is a rare cause of spontaneous OHSS. TSS improves clinical and biochemical features of ovarian hyperstimulation in FGAs. Improved awareness of FGA will prevent inappropriate emergency ovarian surgery.

Large language models encode clinical knowledge.

Large language models (LLMs) have demonstrated impressive capabilities, but the bar for clinical applications is high. Attempts to assess the clinical knowledge of models typically rely on automated evaluations based on limited benchmarks. Here, to address these limitations, we present MultiMedQA, a benchmark combining six existing medical question answering datasets spanning professional medicine, research and consumer queries and a new dataset of medical questions searched online, HealthSearchQA. We propose a human evaluation framework for model answers along multiple axes including factuality, comprehension, reasoning, possible harm and bias. In addition, we evaluate Pathways Language Model1 (PaLM, a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM2 on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA3, MedMCQA4, PubMedQA5 and Measuring Massive Multitask Language Understanding (MMLU) clinical topics6), including 67.6% accuracy on MedQA (US Medical Licensing Exam-style questions), surpassing the prior state of the art by more than 17%. However, human evaluation reveals key gaps. To resolve this, we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, knowledge recall and reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLMs for clinical applications.

Dynamics of diurnal cortisol and alpha-amylase secretion and their associations with PTSD onset in recent interpersonal trauma survivors.

BACKGROUND: Dysfunction in major stress response systems during the acute aftermath of trauma may contribute to risk for developing posttraumatic stress disorder (PTSD). The current study investigated how PTSD diagnosis and symptom severity, depressive symptoms, and childhood trauma uniquely relate to diurnal neuroendocrine secretion (cortisol and alpha-amylase rhythms) in women who recently experienced interpersonal trauma compared to non-traumatized controls (NTCs). METHOD: Using a longitudinal design, we examined diurnal cortisol and alpha-amylase rhythms in 98 young women (n = 57 exposed to recent interpersonal trauma, n = 41 NTCs). Participants provided saliva samples and completed symptom measures at baseline and 1-, 3-, and 6-month follow-up. RESULTS: Multilevel models (MLMs) revealed lower waking cortisol predicted the development of PTSD in trauma survivors and distinguished at-risk women from NTCs. Women with greater childhood trauma exposure exhibited flatter diurnal cortisol slopes. Among trauma-exposed individuals, lower waking cortisol levels were associated with higher concurrent PTSD symptom severity. Regarding alpha-amylase, MLMs revealed women with greater childhood trauma exposure exhibited higher waking alpha-amylase and slower diurnal alpha-amylase increase. CONCLUSIONS: Results suggest lower waking cortisol in the acute aftermath of trauma may be implicated in PTSD onset and maintenance. Findings also suggest childhood trauma may predict a different pattern of dysfunction in stress response systems following subsequent trauma exposure than the stress system dynamics associated with PTSD risk; childhood trauma appears to be associated with flattened diurnal cortisol and alpha-amylase slopes, as well as higher waking alpha-amylase.

Treatment-resistant depression with anhedonia: Integrating clinical and preclinical approaches to investigate distinct phenotypes.

In our clinical work with treatment-resistant depressed (TRD) patients, certain patterns have emerged in terms of patients' presentations of anhedonia. Multiple studies have investigated anhedonia either as a state or a trait variable in depression, but anhedonia is a multifaceted construct and, as we better understand anhedonia, we increase our ability to measure and treat it. With the aim of personalizing medicine for more efficacious treatments, this paper focuses on clinical patterns we have seen in anhedonic TRD and argues for studies to be done in support of translational, face, and construct validity. Three representative clinical presentations of TRD with anhedonia are described: a congenital type, a stress-induced type, and a type exacerbated by medication. Each case is followed with discussion relating the clinical features to clinical and preclinical research relevant to putative mechanisms for the case. Animal models that are best suited to investigate and validate the existence of etiologies and mechanisms underlying anhedonia constructs unique to each case are proposed, as are potential directions for research in humans.

Database resources of the national center for biotechnology information.

The National Center for Biotechnology Information (NCBI) produces a variety of online information resources for biology, including the GenBank® nucleic acid sequence database and the PubMed® database of citations and abstracts published in life science journals. NCBI provides search and retrieval operations for most of these data from 35 distinct databases. The E-utilities serve as the programming interface for the most of these databases. Resources receiving significant updates in the past year include PubMed, PMC, Bookshelf, RefSeq, SRA, Virus, dbSNP, dbVar, ClinicalTrials.gov, MMDB, iCn3D and PubChem. These resources can be accessed through the NCBI home page at https://www.ncbi.nlm.nih.gov.

Altered smell and taste: Anosmia, parosmia and the impact of long Covid-19.

BACKGROUND: Qualitative olfactory (smell) dysfunctions are a common side effect of post-viral illness and known to impact quality of life and health status. Evidence is emerging that taste and smell loss are common symptoms of Covid-19 that may emerge and persist long after initial infection. The aim of the present study was to document the impact of post Covid-19 alterations to taste and smell. METHODS: We conducted exploratory thematic analysis of user-generated text from 9000 users of the AbScent Covid-19 Smell and Taste Loss moderated Facebook support group from March 24 to 30th September 2020. RESULTS: Participants reported difficulty explaining and managing an altered sense of taste and smell; a lack of interpersonal and professional explanation or support; altered eating; appetite loss, weight change; loss of pleasure in food, eating and social engagement; altered intimacy and an altered relationship to self and others. CONCLUSIONS: Our findings suggest altered taste and smell with Covid-19 may lead to severe disruption to daily living that impacts on psychological well-being, physical health, relationships and sense of self. More specifically, participants reported impacts that related to reduced desire and ability to eat and prepare food; weight gain, weight loss and nutritional insufficiency; emotional wellbeing; professional practice; intimacy and social bonding; and the disruption of people's sense of reality and themselves. Our findings should inform further research and suggest areas for the training, assessment and treatment practices of health care professionals working with long Covid.

Banana Cultivar Field Screening for Resistance to Fusarium oxysporum f.sp. cubense Tropical Race 4 in the Northern Territory.

Fusarium oxysporum f.sp. cubense, causal agent of Panama disease, is one of the biggest threats to global banana production, particularly the Cavendish competent tropical race 4 (Foc TR4). It continues to spread globally with detections occurring in regions of the Middle East and new continents such as Africa and South America in the last decade. As the search was on for new management strategies and resistant cultivars to combat the disease, a banana cultivar-screening trial took place in the Northern Territory of Australia, which examined the responses of 24 banana cultivars to the soil borne fungus. These cultivars included material from TBRI, FHIA and selections from Thailand, Indonesia and Australia and evaluated for their resistance to tropical race 4 for two cropping cycles. Several cultivars displayed considerable resistance to Foc TR4, including several FHIA parental lines and hybrids, the Cavendish (AAA) selections GCTCV 215 and GCTCV 247 from TBRI and an Indonesian selection CJ19 showed either very little to no plant death due to the disease.

Human biventricular electromechanical simulations on the progression of electrocardiographic and mechanical abnormalities in post-myocardial infarction.

AIMS: Develop, calibrate and evaluate with clinical data a human electromechanical modelling and simulation framework for multiscale, mechanistic investigations in healthy and post-myocardial infarction (MI) conditions, from ionic to clinical biomarkers. METHODS AND RESULTS: Human healthy and post-MI electromechanical simulations were conducted with a novel biventricular model, calibrated and evaluated with experimental and clinical data, including torso/biventricular anatomy from clinical magnetic resonance, state-of-the-art human-based membrane kinetics, excitation-contraction and active tension models, and orthotropic electromechanical coupling. Electromechanical remodelling of the infarct/ischaemic region and the border zone were simulated for ischaemic, acute, and chronic states in a fully transmural anterior infarct and a subendocardial anterior infarct. The results were compared with clinical electrocardiogram and left ventricular ejection fraction (LVEF) data at similar states. Healthy model simulations show LVEF 63%, with 11% peak systolic wall thickening, QRS duration and QT interval of 100 ms and 330 ms. LVEF in ischaemic, acute, and chronic post-MI states were 56%, 51%, and 52%, respectively. In linking the three post-MI simulations, it was apparent that elevated resting potential due to hyperkalaemia in the infarcted region led to ST-segment elevation, while a large repolarization gradient corresponded to T-wave inversion. Mechanically, the chronic stiffening of the infarct region had the benefit of improving systolic function by reducing infarct bulging at the expense of reducing diastolic function by inhibiting inflation. CONCLUSION: Our human-based multiscale modelling and simulation framework enables mechanistic investigations into patho-physiological electrophysiological and mechanical behaviour and can serve as testbed to guide the optimization of pharmacological and electrical therapies.

Insight Into Myocardial Microstructure of Athletes and Hypertrophic Cardiomyopathy Patients Using Diffusion Tensor Imaging.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) remains the commonest cause of sudden cardiac death among young athletes. Differentiating between physiologically adaptive left ventricular (LV) hypertrophy observed in athletes' hearts and pathological HCM remains challenging. By quantifying the diffusion of water molecules, diffusion tensor imaging (DTI) MRI allows voxelwise characterization of myocardial microstructure. PURPOSE: To explore microstructural differences between healthy volunteers, athletes, and HCM patients using DTI. STUDY TYPE: Prospective cohort. POPULATION: Twenty healthy volunteers, 20 athletes, and 20 HCM patients. FIELD STRENGTH/SEQUENCE: 3T/DTI spin echo. ASSESSMENT: In-house MatLab software was used to derive mean diffusivity (MD) and fractional anisotropy (FA) as markers of amplitude and anisotropy of the diffusion of water molecules, and secondary eigenvector angles (E2A)-reflecting the orientations of laminar sheetlets. STATISTICAL TESTS: Independent samples t-tests were used to detect statistical significance between any two cohorts. Analysis of variance was utilized for detecting the statistical difference between the three cohorts. Statistical tests were two-tailed. A result was considered statistically significant at P ≤ 0.05. RESULTS: DTI markers were significantly different between HCM, athletes, and volunteers. HCM patients had significantly higher global MD and E2A, and significantly lower FA than athletes and volunteers. (MDHCM = 1.52 ± 0.06 × 10-3 mm2 /s, MDAthletes = 1.49 ± 0.03 × 10-3 mm2 /s, MDvolunteers = 1.47 ± 0.02 × 10-3 mm2 /s, P < 0.05; E2AHCM = 58.8 ± 4°, E2Aathletes = 47 ± 5°, E2Avolunteers = 38.5 ± 7°, P < 0.05; FAHCM = 0.30 ± 0.02, FAAthletes = 0.35 ± 0.02, FAvolunteers = 0.36 ± 0.03, P < 0.05). HCM patients had significantly higher E2A in their thickest segments compared to the remote (E2Athickest = 66.8 ± 7, E2Aremote = 51.2 ± 9, P < 0.05). DATA CONCLUSION: DTI depicts an increase in amplitude and isotropy of diffusion in the myocardium of HCM compared to athletes and volunteers as reflected by increased MD and decreased FA values. While significantly higher E2A values in HCM and athletes reflect steeper configurations of the myocardial sheetlets than in volunteers, HCM patients demonstrated an eccentric rise in E2A in their thickest segments, while athletes demonstrated a concentric rise. Further studies are required to determine the diagnostic capabilities of DTI. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY STAGE: 2.

Art participation for psychosocial wellbeing during stroke rehabilitation: a feasibility randomised controlled trial.

PURPOSE: To examine the feasibility of undertaking a pragmatic single-blind randomised controlled trial (RCT) of a visual arts participation programme to evaluate effects on survivor wellbeing within stroke rehabilitation. METHODS: Stroke survivors receiving in-patient rehabilitation were randomised to receive eight art participation sessions (n = 41) or usual care (n = 40). Recruitment, retention, preference for art participation and change in selected outcomes were evaluated at end of intervention outcome assessment and three-month follow-up. RESULTS: Of 315 potentially eligible participants 81 (29%) were recruited. 88% (n = 71) completed outcome and 77% (n = 62) follow-up assessments. Of eight intervention group non-completers, six had no preference for art participation. Outcome completion varied between 97% and 77%. Running groups was difficult because of randomisation timing. Effectiveness cannot be determined from this feasibility study but effects sizes suggested art participation may benefit emotional wellbeing, measured on the positive and negative affect schedule, and self-efficacy for Art (d = 0.24-0.42). CONCLUSIONS: Undertaking a RCT of art participation within stroke rehabilitation was feasible. Art participation may enhance self-efficacy and positively influence emotional wellbeing. These should be outcomes in a future definitive trial. A cluster RCT would ensure art groups could be reliably convened. Fewer measures, and better retention strategies are required. Implications for Rehabilitation This feasibility randomised controlled trial (RCT) showed that recruiting and retaining stroke survivors in an RCT of a visual arts participation intervention within stroke rehabilitation was feasible. Preference to participate in art activities may influence recruitment and drop-out rates, and should be addressed and evaluated fully. Art participation as part of rehabilitation may improve some aspects of post-stroke wellbeing, including positive affect and self-efficacy for art. A future definitive cluster RCT would facilitate full evaluation of the value art participation can add to rehabilitation.

Social context, art making processes and creative output: a qualitative study exploring how psychosocial benefits of art participation during stroke rehabilitation occur.

PURPOSE: To explore stroke survivors' and artists' beliefs about participatory visual arts programme participation during in-patient rehabilitation to identify benefits and potential mechanisms of action. METHOD: Qualitative design using semi-structured in-depth interviews with stroke survivors (n = 11) and artists (n = 3). ANALYSIS: Data were audio-recorded and transcribed. Framework approach was used to identify themes and develop conceptual schemes. RESULTS: The non-medical, social context of art facilitated social interaction, provided enjoyment and distraction from stroke and re-established social identity thereby improving mood. The processes of art making generated confidence and self-efficacy, setting and achievement of creative, communication and physical recovery goals that provided control over survivors' situation and hope for recovery. Creative output involved completion of artwork and display for viewing. This enhanced self-esteem and improved mood, providing survivors with new identities through positive appraisal of the work by others. Self-efficacy, hope and control appeared to mediate benefits. CONCLUSION: This study provides a model of intervention components, mechanisms of action and outcome mediators to explain how art participation may work. Findings suggest that art may influence important psychosocial outcomes that other rehabilitation approaches do not typically address. The study paves the way for a future effectiveness trial. IMPLICATIONS FOR REHABILITATION: Participation in an art programme during rehabilitation appears to improve stroke survivors' mood, confidence and self-esteem and enhances perceptions of hope and control over recovery. Social interactions, the processes of art making and review and appraisal by others may be key intervention components from which benefits are derived. Benefits from art participation may enhance survivors' experiences of rehabilitation and appear to provide benefits that other rehabilitation interventions do not. Art participation should be considered as an important adjunct to traditional rehabilitation.

Feasibility study of the effects of art as a creative engagement intervention during stroke rehabilitation on improvement of psychosocial outcomes: study protocol for a single blind randomized controlled trial: the ACES study.

BACKGROUND: Benefits of art participation after stroke are becoming increasingly recognized. Qualitative studies suggest that participation in visual arts creative engagement interventions (CEIs) during rehabilitation after stroke may improve mood, self-esteem, hope and some aspects of physical recovery. This study examines the feasibility of undertaking a randomized controlled trial of a CEI delivered by artists within in-patient stroke rehabilitation to test effectiveness. METHODS/DESIGN: This trial is a two arm, single-blind, randomized controlled feasibility trial within in-patient stroke rehabilitation. We will recruit 80 patients receiving stroke rehabilitation in two stroke units in a health board area of Scotland (40 patients in each arm). Intervention arm participants will receive a visual-arts based CEI facilitated by experienced artists. Artists will follow an intervention protocol with specific components that enable participants to set, achieve and review artistic goals. Participants will receive up to eight intervention sessions, four within a group and four one-to-one with the artist. Control group participants will receive usual care only.Data collection will occur at baseline, post-intervention and three-month follow-up. Stroke-related health status is the primary outcome; mood, self-esteem, self-efficacy, perceived recovery control and hope are secondary outcomes. Semi-structured interviews will be conducted with purposively selected patients, artists and healthcare staff to elicit views and experiences of the intervention and feasibility and acceptability of trial processes. Recruitment rates, retention rates and patient preference for art participation will also be collected. Data will indicate, with confidence intervals, the proportion of patients choosing or refusing participation in the CEI and will allow calculation of recruitment rates for a future definitive trial. Summary data will indicate potential variability, magnitude and direction of difference between groups. Findings will inform sample size calculations for a definitive trial. Thematic analysis of qualitative data will be managed using the Framework Approach. Framework is an analytical approach for qualitative data, commonly used in policy and medical research. DISCUSSION: If shown to demonstrate effects, this intervention has the potential to address aspects of stroke recovery previously. Not routinely addressed in rehabilitation. TRIAL REGISTRATION: Registered with Clinical Trials.Gov: NCT02085226 on 6th March 2014.

Suffix tree searcher: exploration of common substrings in large DNA sequence sets.

BACKGROUND: Large DNA sequence data sets require special bioinformatics tools to search and compare them. Such tools should be easy to use so that the data can be easily accessed by a wide array of researchers. In the past, the use of suffix trees for searching DNA sequences has been limited by a practical need to keep the trees in RAM. Newer algorithms solve this problem by using disk-based approaches. However, none of the fastest suffix tree algorithms have been implemented with a graphical user interface, preventing their incorporation into a feasible laboratory workflow. RESULTS: Suffix Tree Searcher (STS) is designed as an easy-to-use tool to index, search, and analyze very large DNA sequence datasets. The program accommodates very large numbers of very large sequences, with aggregate size reaching tens of billions of nucleotides. The program makes use of pre-sorted persistent "building blocks" to reduce the time required to construct new trees. STS is comprised of a graphical user interface written in Java, and four C modules. All components are automatically downloaded when a web link is clicked. The underlying suffix tree data structure permits extremely fast searching for specific nucleotide strings, with wild cards or mismatches allowed. Complete tree traversals for detecting common substrings are also very fast. The graphical user interface allows the user to transition seamlessly between building, traversing, and searching the dataset. CONCLUSIONS: Thus, STS provides a new resource for the detection of substrings common to multiple DNA sequences or within a single sequence, for truly huge data sets. The re-searching of sequence hits, allowing wild card positions or mismatched nucleotides, together with the ability to rapidly retrieve large numbers of sequence hits from the DNA sequence files, provides the user with an efficient method of evaluating the similarity between nucleotide sequences by multiple alignment or use of Logos. The ability to re-use existing suffix tree pieces considerably shortens index generation time. The graphical user interface enables quick mastery of the analysis functions, easy access to the generated data, and seamless workflow integration.

Artificial urinary sphincter revision: the role of ultrasound.

OBJECTIVE: To assess the accuracy of office-based ultrasound (US) to identify the fluid status of the AMS 800 artificial urinary sphincter (AUS) pressure-regulating balloon (PRB). METHODS: Patients who underwent AUS revision surgery (removal/replacement) from January 4, 2007, to January 4, 2010, were identified. US were done preoperatively to assess the system fluid status. Intraoperative findings were recorded. Sensitivity and specificity were calculated comparing US results with intra-/postoperative findings. When the PRB was underfilled, the location of the device fluid leak was determined, and the device was removed/replaced. In cases of a full PRB, patients had a cuff downsizing or total removal/replacement. RESULTS: A total of 27 patients were identified. Reasons for not obtaining US included: advanced device age (4), cuff erosion (2), volume determination by other modality (2), cuff site pain (1), isolated pump malfunctions (1), and other (3). Fourteen patients underwent an US before the removal/replacement. By US, PRB was full (21-23 mL) in 43% of the patients and empty/underfilled (0-6 mL) in 57%. US was 100% sensitive and specific determining fluid status. When PRB was full, management consisted of cuff downsizing (3), transcorporal cuff placement (1), and total removal/replacement (2). In all cases of device leak, an entire removal/replacement was performed. The cuff was identified as the site of leak in 50% of cases. CONCLUSION: US is an effective and accurate way of determining the fluid status of the AMS 800 AUS. Given the accuracy of this modality, the system can be filled with saline solution without losing the ability to determine fluid status.

Campaign best practice in intravenous therapy.

Intravenous therapy is an integral part of nursing care but is associated with a high risk of infection. This article outlines a campaign that aimed to increase awareness of best practice for IV therapy and reduce the risks of healthcare-associated IV infections in hospital and community settings.

Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost.

INTRODUCTION: A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. METHODS: CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. RESULTS: CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). CONCLUSION: IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.

Fabrication and characterization of an all-diamond tubular flow microelectrode for electroanalysis.

The development of the first all-diamond hydrodynamic flow device for electroanalytical applications is described. Here alternate layers of intrinsic (insulating), conducting (heavily boron doped), and intrinsic polycrystalline diamond are grown to create a sandwich structure. By laser cutting a hole through the material, it is possible to produce a tubular flow ring electrode of a characteristic length defined by the thickness of the conducting layer (for these studies ∼90 µm). The inside of the tube can be polished to 17 ± 10 nm surface roughness using a diamond impregnanted wire resulting in a coplanar, smooth, all-diamond surface. The steady-state limiting current versus volume flow rate characteristics for the one electron oxidation of FcTMA(+) are in agreement with those expected for laminar flow in a tubular electrode geometry. For dopamine detection, it is shown that the combination of the reduced fouling properties of boron doped diamond, coupled with the flow geometry design where the products of electrolysis are washed away downstream of the electrode, completely eradicates fouling during electrolysis. This paves the way for incorporation of this flow design into online electroanalytical detection systems. Finally, the all diamond tubular flow electrode system described here provides a platform for future developments including the development of ultrathin ring electrodes, multiple apertures for increased current response, and multiple, individually addressable ring electrodes incorporated into the same flow tube.

Risk and protective genetic variants in suicidal behaviour: association with SLC1A2, SLC1A3, 5-HTR1B &NTRK2 polymorphisms.

BACKGROUND: Suicidal behaviour is known to aggregate in families. Patients with psychiatric disorders are at higher risk for suicide attempts (SA), however protective and risk genetic variants for suicide appear to be independent of underlying psychiatric disorders. Here we investigate genetic variants in genes important for neurobiological pathways linked to suicidal behaviour and/or associated endophenotypes, for association with SA among patients with co-existing psychiatric illness. Selected gene-gene and gene-environment interactions were also tested. METHODS: DNA was obtained from bloods of 159 patients (76 suicide attempters and 83 non-attempters), who were profiled for DSM-IV Axis I psychiatric diagnosis. Twenty-eight single nucleotide polymorphisms (SNPs) from 18 candidate genes (COMT, 5-HT2A, 5-HT1A, 5-HTR1B, TPH1, MAO-A, TPH2, DBH, CNR1, BDNF, ABCG1, GABRA5, GABRG2, GABRB2, SLC1A2, SLC1A3, NTRK2, CRHR1) were genotyped. Genotyping was performed by KBioscience. Tests of association between genetic variants and SA were conducted using Chi squared and Armitage Trend tests. Binary logistical regression analyses were performed to evaluate the contribution of individual genetic variants to the prediction of SA, and to examine SNPs for potential gene-gene and gene-environment interactions. RESULTS: Our analysis identified 4 SNPs (rs4755404, rs2269272, rs6296 and rs1659400), which showed evidence of association with SA compared to a non-attempter control group. We provide evidence of a 3-locus gene-gene interaction, and a putative gene-environment interaction, whereby genetic variation at the NTRK2 locus may moderate the risk associated with history of childhood abuse. CONCLUSION: Preliminary findings suggest that allelic variability in SLC1A2/3, 5-HTR1B and NTRK2 may be relevant to the underlying diathesis for suicidal acts.