Echocardiographic assessment of pressure volume relations in heart failure and valvular heart disease: using imaging to understand physiology

Pressure volume (PV) based analysis, using classic hemodynamic principles, has served as a basis for our understanding of cardiac physiology and disease states for decades. However, PV analysis has been restricted to primarily the basic research setting and for preclinical testing and has not be widely applied in part because of the invasive nature of the procedure and the expertise required to obtain adequate data using the conductance catheter. Development of single beat methodologies that rely on echocardiographic measurements of ventricular volume and Doppler and peripheral estimates of ventricular pressure and timing of the cardiac cycle has enabled broader application of PV analysis. This review explores the physiologic background, basic methodology, and recent and potential future applications of noninvasive PV analysis.

Cytoskeletal dynamics in interphase, mitosis and cytokinesis analysed through Agrobacterium-mediated transient transformation of tobacco BY-2 cells

Transient transformation with Agrobacterium is a widespread tool allowing rapid expression analyses in plants. However, the available methods generate expression in interphase and do not allow the routine analysis of dividing cells. Here, we present a transient transformation method (termed 'TAMBY2') to enable cell biological studies in interphase and cell division. Agrobacterium-mediated transient gene expression in tobacco BY-2 was analysed by Western blotting and quantitative fluorescence microscopy. Time-lapse microscopy of cytoskeletal markers was employed to monitor cell division. Double-labelling in interphase and mitosis enabled localization studies. We found that the transient transformation efficiency was highest when BY-2/Agrobacterium co-cultivation was performed on solid medium. Transformants produced in this way divided at high frequency. We demonstrated the utility of the method by defining the behaviour of a previously uncharacterized microtubule motor, KinG, throughout the cell cycle. Our analyses demonstrated that TAMBY2 provides a flexible tool for the transient transformation of BY-2 with Agrobacterium. Fluorescence double-labelling showed that KinG localizes to microtubules and to F-actin. In interphase, KinG accumulates on microtubule lagging ends, suggesting a minus-end-directed function in vivo. Time-lapse studies of cell division showed that GFP-KinG strongly labels preprophase band and phragmoplast, but not the metaphase spindle.

Isolated word recognition of silent speech using magnetic implants and sensors

There are a number of situations where individuals wish to communicate verbally but are unable to use conventional means-so called 'silent speech'. These include speakers in noisy and covert situations as well as patients who have lost their voice as a result of a laryngectomy or similar procedure. This paper focuses on those who are unable to speak following a laryngectomy and assesses the possibility of speech recognition based on a magnetic implant/sensors system. Permanent magnets are placed on the tongue and lips and the changes in magnetic field resulting from movement during speech are monitored using a set of magnetic sensors. The sensor signals are compared to sets of pre-recorded templates using the dynamic time warping (DTW) method, and the best match is identified. Experimental trials are reported for subjects with intact larynx, typically using 500-1000 utterances used for speaker dependant training and testing. It is shown that recognition rates of over 90% are achievable for vocabularies of at least 57 isolated words: sufficient to drive command-and-control applications.

Antenatal management of pulmonary hyperplasia (congenital cystic adenomatoid malformation)

A 26-year-old lady was seen in antenatal clinic. Her anomaly scan at 20 weeks showed significant fetal abdominal ascites and an enlarged echo bright right lung with cardiac displacement. These findings were consistent with recognised type III congenital cystic adenomatoid malformation (CCAM). An induction of labour was undertaken at 32 weeks' gestation due to increasing maternal morbidity. Labour was complicated by abdominal dystocia and a fetal paracentesis was performed, draining 800 ml. A bradycardia developed and the baby was ultimately stillborn. Post mortem examination the right lower lobe bronchus was atretic. The features were typical of those traditionally described as type III CCAM, but in the context of bronchial atresia, are better described as pulmonary hyperplasia.

Assessing training in sexual dysfunction for genitourinary medicine registrars

The training programme for specialist registrars in genitourinary medicine (GU) lists sexual dysfunction (SD) as ‘beyond essential, core curriculum’ despite many GU medicine clinics offering this service. A cross-sectional study was performed of all trainees on the British Association for Sexual Health and HIV mailing list. Data collected included frequency of clinics attended and involvement, any training and interest in future training. A total of 39/76 (51%) responses were received. In total, 20/39 (51%) work in departments with no SD clinic provision, and 12/39 have had some training in SD. In routine GU medicine consultation, 85% trainees are consulted regarding SD at least monthly. In all, 19/39 (49%) work in areas with weekly SD clinics; however, only three trainees were involved. Thirty-four out of 39 (87%) expressed interest in training and 31/39 (79%) respondents would like to see SD training added to the SpR curriculum. Fifty-one percent of juniors work in units without SD provision. Even when SD clinics occur, only three trainees are routinely involved and a large training opportunity is being missed. Despite this, 12/39 trainees have sought out extra training in the form of seminars, courses and meetings. Eighty-five percent wished to have SD as part of the core curriculum as they may ultimately work in an area where these skills are required.

Maternal depression and medication exposure during pregnancy: comparison of maternal retrospective recall to prospective documentation

OBJECTIVE

Outcome investigations of prenatal maternal depression and psychotropic exposure rely extensively on maternal retrospective recall. This study compared postnatal recall to prospective documentation of illness and medication exposures.

DESIGN

Prospective cohort and retrospective case-control studies.

SETTING

Emory Women's Mental Health Program (prospective study) and Emory University Department of Psychology (retrospective study).

SAMPLE

A total of 164 women who participated in both the prospective and retrospective studies.

METHODS

Women with a history of mental illness were followed during pregnancy for prospective prenatal assessments of depression and medication exposures. At 6 months postpartum, some of these women also participated in a retrospective study during which they were asked to recall prenatal depression and medication use. Agreement between prospective and retrospective documentation of exposures was analysed.

MAIN OUTCOME MEASURES

Occurrence of maternal depression during pregnancy and maternal use of pharmacological agents during pregnancy.

RESULTS

There was only moderate agreement (k = 0.42) in prospective versus retrospective reporting of prenatal depression. Positive predictive value for recalling depression was 90.4%; however, negative predictive value for denying depression was only 53.8%. Participants accurately recalled psychotropic use but significantly underreported use of nonpsychotropic medications.

CONCLUSIONS

Studies using retrospective data collection may be susceptible to systematic recall bias with underreporting of maternal depression and use of nonpsychotropic agents during pregnancy.

Sexual dysfunction service provision in UK genitourinary medicine clinics in 2007

Sexual difficulties are common in people attending genitourinary (GU) medicine/HIV services and many would like professional help. Here, we report the results of the BASHH Special Interest Group in Sexual Dysfunction (SD) survey on the level and type of SD service provision within UK GU medicine services in 2007. Many clinicians expressed an interest in SD, however, only 25% of GU medicine clinics provide a designated SD service. Marked regional variation in the level of service provision was highlighted. Lack of resources and other pressures on GU medicine services, notably 48-h access, are barriers to SD service development. In spite of these constraints, we argue that GU medicine clinics are a highly appropriate place to treat SD.

Obstetric skills drills: evaluation of teaching methods

OBJECTIVE

To determine the most effective method of delivering training to staff on the management of an obstetric emergency.

SUBJECTS

The research was conducted in a District General Hospital in the UK, delivering approximately 3500 women per year. Thirty-six staff, comprising of junior and senior medical and midwifery staff were included as research subjects. Each of the staff members were put into one of six multi-professional teams. Effectively, this gave six teams, each comprising of six members.

METHOD

Three teaching methods were employed. Lecture based teaching (LBT), simulation based teaching (SBT) or a combination of these two (LAS). Each team of staff were randomly allocated to undertake a full day of training in the management of Post Partum Haemorrhage utilising one of these three teaching methods. Team knowledge and performance were assessed pre-training, post training and at three months later. In addition to this assessment of knowledge and performance, qualitative semi-structured interviews were carried out with 50% of the original cohort one year after the training, to explore anxiety, confidence, communication, knowledge retention, enjoyment and transferable skills.

RESULTS

All teams improved in their performance and knowledge. The teams taught using simulation only (SBT) were the only group to demonstrate sustained improvement in clinical management of the case, confidence, communication skills and knowledge. However, the study did not have enough power to reach statistical significance. The SBT group reported transferable skills and less anxiety in subsequent emergencies. SBT and LAS reported improved multidisciplinary communication. Although tiring, the SBT was enjoyed the most.

CONCLUSION

Obstetrics is a high risk speciality, in which emergencies are to some extent, inevitable. Training staff to manage these emergencies is a fundamental principal of risk management. Traditional risk management strategies based on incident reporting and event analysis are reactive and not always effective. Simulation based training is an appropriate proactive approach to reducing errors and risk in obstetrics, improving teamwork and communication, whilst giving the student a multiplicity of transferable skills to improve their performance.

Vagus nerve stimulation for epilepsy: is output current correlated with acute response?

OBJECTIVES

Vagus nerve stimulation (VNS) is an effective treatment for intractable epilepsy. It is unknown whether acute response is correlated with the amplitude of output current. The purpose of this study was to determine if the output current of VNS is correlated with percent reductions in seizure frequency and response.

MATERIALS AND METHODS

Retrospective analysis of a multicenter randomized trial of three unique paradigms of VNS was carried out in patients with intractable partial onset epilepsy. Output current at 1 and 3 months was correlated with percent reduction in seizure frequency and response rates.

RESULTS

Sixty-one subjects were enrolled and completed the study. Output current, ranging from 0.25 to 1.5 mA, was not correlated with reductions in seizure frequency, or with > or = 50% reduction in seizures. Six of seven initial non-responders did experience > or = 50% reductions in seizures after current was increased.

CONCLUSIONS

The output current is not a major determinant of acute response to VNS for epilepsy. Many patients respond to low current (<1 mA). Some (20%) initial non-responders may respond to an increase in output current.

The novel endocannabinoid receptor GPR55 is activated by atypical cannabinoids but does not mediate their vasodilator effects

BACKGROUND AND PURPOSE

Atypical cannabinoids are thought to cause vasodilatation through an as-yet unidentified 'CBx' receptor. Recent reports suggest GPR55 is an atypical cannabinoid receptor, making it a candidate for the vasodilator 'CBx' receptor. The purpose of the present study was to test the hypothesis that human recombinant GPR55 is activated by atypical cannabinoids and mediates vasodilator responses to these agents.

EXPERIMENTAL APPROACH

Human recombinant GPR55 was expressed in HEK293T cells and specific GTPgammaS activity was monitored as an index of receptor activation. In GPR55-deficient and wild-type littermate control mice, in vivo blood pressure measurement and isolated resistance artery myography were used to determine GPR55 dependence of atypical cannabinoid-induced haemodynamic and vasodilator responses.

KEY RESULTS

Atypical cannabinoids O-1602 and abnormal cannabidiol both stimulated GPR55-dependent GTPgammaS activity (EC50 approximately 2 nM), whereas the CB1 and CB2-selective agonist WIN 55,212-2 showed no effect in GPR55-expressing HEK293T cell membranes. Baseline mean arterial pressure and heart rate were not different between WT and GPR55 KO mice. The blood pressure-lowering response to abnormal cannabidiol was not different between WT and KO mice (WT 20+/-2%, KO 26+/-5% change from baseline), nor was the vasodilator response to abnormal cannabidiol in isolated mesenteric arteries (IC50 approximately 3 micro M for WT and KO). The abnormal cannabidiol vasodilator response was antagonized equivalently by O-1918 in both strains.

CONCLUSIONS

These results demonstrate that while GPR55 is activated by atypical cannabinoids, it does not appear to mediate the vasodilator effects of these agents.

S100A8 triggers oxidation-sensitive repulsion of neutrophils

The inflammatory response to tissue injury is a multi-faceted process. During this process, neutrophils migrate in the extravascular spaces, directed to the site of injury by chemical gradients generated by chemotactic molecules. S100A8, a protein associated with a wide variety of inflammatory conditions, is heavily over-expressed in association with inflammation. We hypothesized that human S100A8 possesses neutrophil-repelling properties that result in an anti-inflammatory effect in vivo. The chemotactic activity of S100A8 on neutrophils was tested in Transwell chemotaxis assays. Analysis of the data indicates that S100A8 causes a repulsion of peripheral neutrophils, an activity that S100A8 loses upon its oxidation. Using a mutant of S100A8 resistant to oxidation and consistent with the in vitro findings, we demonstrated that S100A8 causes a strong anti-inflammatory effect in the rat air-pouch model of inflammation in vivo. These data highlight a naturally occurring novel anti-inflammatory pathway and provide potential molecular targets for the development of novel anti-inflammatory therapeutics. Abbrevations: ethylene diamine tetraacetic acid (EDTA); limulus amoebocyte lysate assay (LAL); pertussis toxin (PTX); forward scatter (FSC); Interleukin-8 (IL-8); formyl-Met-Leu-Phe (fMLP); monocyte chemotactic protein 1 (MCP1).

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of parasiticides for the treatment, prevention and control of flea and tick infestation on dogs and cats

These guidelines are intended to assist the planning and conduct of laboratory and clinical studies to assess the efficacy of ectoparasiticides applied to dogs or cats for the purpose of treating, preventing and controlling flea and tick infestations. The term ectoparasiticide includes insecticidal and acaricidal compounds, as well as insect growth regulators. The range of biological activities accruing from animal treatment that are considered include: repellency and anti-feeding effects, knockdown, speed of kill, immediate and persistent lethal effects, and interference with egg fertility and subsequent development of off-host life cycle stages. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping, interpretation of results and animal welfare. These guidelines are also intended to assist registration authorities involved in the approval and registration of new parasiticides, and to facilitate the worldwide adoption of harmonized procedures.

Scan of human genome reveals no new Loci under ancient balancing selection

There has been much speculation as to what role balancing selection has played in evolution. In an attempt to identify regions, such as HLA, at which polymorphism has been maintained in the human population for millions of years, we scanned the human genome for regions of high SNP density. We found 16 regions that, outside of HLA and ABO, are the most highly polymorphic regions yet described; however, evidence for balancing selection at these sites is notably lacking--indeed, whole-genome simulations indicate that our findings are expected under neutrality. We propose that (i) because it is rarely stable, long-term balancing selection is an evolutionary oddity, and (ii) when a balanced polymorphism is ancient in origin, the requirements for detection by means of SNP data alone will rarely be met.

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of acaricides against ticks (Ixodidae) on ruminants

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of the efficacy of acaricides (excluding vaccines and other bio-control agents) against single and multi-host ticks (Ixodidae) on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. The use of pen facilities is advocated for dose determination and confirmation studies for defining therapeutic and persistent efficacy. A minimum of two studies per tick species for which claims are sought is recommended for each dose determination and dose confirmation investigation. If dose confirmation studies demonstrate greater than 95% efficacy the sponsor may proceed to field studies, where a minimum of two studies per geographical location is preferred to confirm the therapeutic and persistent efficacy under field conditions. If dose confirmation studies demonstrate less than 95% efficacy then longer-term field studies can be conducted over two tick seasons with a minimum of two studies per geographical location. These studies can incorporate other control methods such as tick vaccines, to demonstrate stable long-term tick management. Specific advice is also given on conducting studies with paralysis ticks. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new acaricides, and to facilitate the worldwide adoption of standard procedures.

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of ectoparasiticides against myiasis causing parasites on ruminants

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of efficacy of ectoparasiticides against the myiasis causing parasites of ruminants. These guidelines specifically focus on larvicidal efficacy against myiasis causing flies. Information is provided on the selection of animals, dose determination and dose confirmation studies, field studies, record keeping and result interpretation. These guidelines advocate the use of pen facilities for dose determination and dose confirmation studies for defining therapeutic and persistent efficacy. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new ectoparasiticides, and to facilitate the world-wide adoption of standard procedures.

Identifying the impact of diabetes research

AIMS

Assessment of the impact of health research is a growing but problematic field. We examined how a combination of approaches might together inform assessment of the impact of a body of diabetes research published in 1981 and help identify factors behind success.

METHODS

Three broad approaches were applied to the work of one team leader of acknowledged influence. Standard bibliographic analysis was complemented by a second approach which categorized the importance of the primary publications to the papers citing them, in four domains. In parallel, a third approach involved qualitative assessment using surveys, critical pathway analysis by, and interviews of, co-authors and external experts. Extending the approach incorporated key additional publications from other years.

RESULTS

In 1981, the team leader published 29 papers. Citations to these 29 first generation papers varied from 1 to 76 and resulted in 799 second generation papers. Citations to these produced 12 891 third generation papers. Analysis of second generation papers suggested the cited first generation paper was thought to be of considerable or essential significance in only 9% of cases. While much research made little impact, qualitative analysis included a wealth of information, sometimes missed by standard bibliographic techniques, on where the identified research influenced important streams of clinical development. Analysis covered major research studies (such as the Diabetes Control and Complications Trial), insulin pump therapy, and career development of co-authors.

CONCLUSIONS

Understanding the impact of research requires multiple approaches. With refinement, these techniques could be employed more widely and potentially could inform research policy.

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of ectoparasiticides against biting lice, sucking lice and sheep keds on ruminants

These guidelines have been prepared to assist in the design, implementation and interpretation of studies for the assessment of the efficacy of ectoparasiticides against biting and sucking lice and sheep keds on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. These guidelines advocate the use of pen facilities for dose determination and dose confirmation studies for defining therapeutic and persistent efficacy. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision making process, to assist in the approval and registration of new ectoparasiticides, and to facilitate the world-wide adoption of standard procedures.