Mental Health and economic effects: correlation between unemployment and psychoactive drugs

Introduction

Mental Health is an invisible part of public health, and a determinant of it by affecting the human, social and economic capital of countries. Is one of the main causes of disability worldwide and, when left untreated, they can lead to increased costs and premature mortality. In 2019 they represented 22% of the disability burden in DALY in the European Union. Regarding the effects of economic recessions studies suggest that they have detrimental effects on mental health. And can became a reality in the current pandemic scenario.

Objectives

To reflect on the studies carried out that debate the effects of previous economic crises on mental health, particularly the 2008-2013 crisis. It aims to list not only the possible intervention strategies in the area as well as the barriers to their implementation.

Methods

Classic review of the topic through the international literature and the state of the art on available platforms. Establish a proxy between the unemployment rate and the number of packages (antidepressants and anxiolytics consumed) in homologous periods as a representative capacity of the impact of the crisis on mental health.

Results

The number of packages of antidepressants and anxiolytics behave differently. the antidepressants have greater consumption when unemployment decreases.

Conclusions

Several studies describe that the increase in the unemployment rate, indebtedness and social exclusion are empirically proven as consequences of the economic crises and predisposing factors for mental pathology. However, this does not translate into a proxy for the consumption of antidepressant packages with the increase in the unemployment rate. It may be due to the non-prioritization of mental health.

Disclosure

No significant relationships.

The effect of frequency modulation on the FSR of a Fabry-Perot cavity using an Optical Spectrum Analyser

It is presented a study of the dependence between the free spectral range (FSR) and the cavity length in Fabry-Perot interferometers. Furthermore, the effect of frequency modulation on the FSR is studied when an optical spectrum analyser (OSA) is used as an interrogator. For low frequency range it is possible to observe this behaviour in the OSA and using an appropriate processing signal it is possible to use the white light interferometry technique.

Cannabis and Alcohol Co-Use and Condomless Anal Sex Among Men Who have Sex with Men Living with HIV: An Event-Level Analysis

Men who have sex with men (MSM) account for more than two thirds of new HIV diagnoses annually. Sexual behavior that increases risk for onward transmission of HIV is associated with both alcohol and cannabis use. However, little is known about the influence of cannabis and alcohol co-use on engagement in condomless anal sex (CAS). The current study explored daily associations between substance use and CAS among HIV-positive MSM using a 42-day timeline followback interview (N = 101). Generalized estimating equation (GEE) logistic regression models were used to examine the association between cannabis and alcohol co-use and CAS at the sexual event while controlling for study site, condition, adherence to antiretroviral therapy, sex-related alcohol expectancies, and partner type. Participants provided data for 1052 sexual activity days, 60.7% of which involved CAS. Of 638 CAS days, 9.1% involved no substances, 72.0% involved either cannabis or alcohol use, and 18.9% involved cannabis and alcohol co-use. Results indicated that the odds of engaging in CAS were higher for sexual events in which cannabis and alcohol co-use occurred (aOR 2.98; 95% CI 1.27, 6.97) compared to events in which no substance use occurred (p = 0.012), but this relationship was no longer significant when cannabis and alcohol co-use was compared to single substance use (aOR 1.57; 95% CI 0.85, 2.90; p = 0.15). Future research should identify specific substance use (e.g., quantity) and partner characteristics (e.g., level of intoxication) that may uniquely influence the relationship between cannabis and alcohol co-use and condomless sex.

O-122 ICSI in a box: development of a successful automated sperm injection robot with external supervision and minimal manual intervention

Study question

Is it possible to automate the way sperm is injected in an oocyte and improve ICSI consistency between embryologists?

Summary answer

The developed ICSI robot demonstrated a high degree of consistency and operator skill independence, allowing human supervision and external control, but minimal manual intervention.

What is known already

ICSI is a clinical procedure that is currently performed worldwide in most IVF centers and its use will only increase with more utilization of egg freezing. Since its implementation, the technique has been conducted manually by highly skilled embryologists. However, success rates can vary significantly depending on the experience of the operator. We leverage our experience in robotics, AI algorithms and embryology to develop an automated ICSI robot that requires minimal manual intervention with the aim to standardize the consistency of the procedure and, ultimately, improve overall results maintaining embryologist oversight.

Study design, size, duration

The ICSI robot was developed to have supervised automated control on critical steps of the injection procedure, including injection pipette advancement, zona pellucida and oolemma penetration with piezo-pulses, and pipette removal after injection. Manual intervention is required only for immobilization and capture of spermatozoa with a joystick gamepad and to release the sperm in the ooplasm, without the need for micromanipulation skills. In parallel, piezo-ICSI was performed in a conventional micromanipulation station as a control.

Participants/materials, setting, methods

Hamster and mouse oocytes were collected from superovulated females. For testing the efficiency of the automated system, hamster oocytes were injected with human donor sperm, as historically used in manual ICSI training programs, and survival rates evaluated after overnight culture. Mouse oocytes were injected with mouse sperm heads and subsequently cultured in vitro for five days. Blastocysts obtained were vitrified and embryo transfers are ongoing to evaluate term developmental rates.

Main results and the role of chance

The technical components of the ICSI robot were engineered to integrate AI algorithms, optics, cell microinjectors and mechatronics. AI algorithms were developed to identify the morphological structures of MII oocytes, including the zona pellucida, perivitelline space and polar body, both in the hamster and mouse models. The system detects and analyzes both the pipette and the oocyte and chooses the best area and plane for injection, allowing automated control of the subsequent injection steps. Using the hamster oocyte-human sperm model, a survival rate of 91% (n = 110) was achieved with the robot, which was statistically similar (p = 0.335) to the results obtained in the controls injected manually (96%, n = 28). The average time spent in each injection cycle, which includes scanning of the oocyte and injection pipette, and injection of the sperm into the oocyte, was approximately two minutes per ICSI operation. This time was comparable to the time required by highly experienced operators with manual piezo-injection. In the mouse, 91% (n = 53) of the oocytes injected survived the procedure, of which, 92% developed to two-cells and 87% to the blastocyst stage. No statistical differences were found when compared these efficiencies with manual controls (n = 40, 98%, 97% and 92%, respectively).

Limitations, reasons for caution

The developed ICSI robot has shown highly consistent results, independently of operator skills, both in hamster and mouse oocytes. However, additional validations should be performed to enlarge the sample size of injected oocytes and to evaluate the efficiency of the system in other oocyte species, including translational studies to humans.

Wider implications of the findings

The combination of multidisciplinary teams allows the development of automated processes that can reduce variability in certain IVF procedures, while supervised and assisted by experienced embryologists. It is expected that other laboratory procedures can be automated in the field of assisted reproductive treatments in a near future.

Trial registration number

N/A

Revisiting Polymer-Particle Interaction in PEO Solutions

We have measured the electrophoretic mobility and diffusion coefficient of carboxylate-modified and sulfate-modified polystyrene latex particles in poly(ethylene oxide) aqueous solutions. Carboxylate-modified polystyrene particles have shown a bound polymeric layer as the surface net charge vanishes even at very low poly(ethylene oxide) concentration. The polymeric layer causes a lower electrophoretic mobility and slower Brownian diffusion than that corresponding to the bare particles. We show that the diffusion is the result of a significantly increased effective particle size 2r_heff = 30 nm. This bound layer is not present in sulfate-modified polystyrene latex particles. The interaction between the carboxylate-modified particle surface and the macromolecules has been confirmed by means of atomistic computer simulations. The grafted acrylate copolymers, which come from the preparation procedure of the latex particles, confer more hydrophobic surface ready to interact with the polymer. The simulations suggest that the interaction is modulated not only by the nature of the acrylic acid monomer but also by the length of the grafted copolymer. Our results have important implications for particle selection in microrheology experiments.

Therapeutic interventions for PTSD – current evidence on the the role of psychedelics

Introduction

Post-traumatic stress disorder (PTSD) is often a chronic condition, despite the existence of evidence-based treatment options. Psychotherapy is the designated first line treatment for PTSD, although high rates of psychiatric and medical comorbidity are observed among patients who have undergone treatment. The psychoactive properties of psychedelics may be of particular interest within a substance-assisted psychotherapy approach, offering new treatment opportunities for this debilitating disorder.

Objectives

Review current evidence, therapeutic context, and possible mechanisms of action of different types of psychedelics in the treatment of PTSD.

Methods

Literature review using Medline database.

Results

3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy appears to be a potentially safe, effective, and durable treatment for individuals with treatment-refractory PTSD. Based on a small number of studies, ketamine administration appears to result in temporary symptom relief and may, in combination with psychotherapy, lead to lasting reductions in PTSD symptoms. Although these have not yet been investigated in controlled studies, it is known that psilocybin and LSD induce psychoactive effects that could as well contribute to the psychotherapeutic treatment of PTSD.

Conclusions

The use of psychedelic compounds within a substance-assisted psychotherapy framework offers a novel method for pharmacotherapy-psychotherapy integration, although there is still much to learn from both a clinical and neurobiological perspective. It is necessary to generate more data regarding the safety and efficacy of psychedelics, in addition to research on cost-effectiveness, its use in mental health care infrastructure and also regarding the training of specialized therapists.

Colorectal cancer liver metastases: management and five-year survival in a South African patient cohort

BACKGROUND

Approximately 25% of patients with colorectal cancer (CRC) will be diagnosed with CRC liver metastases (CRCLM) during the course of their disease. No data regarding CRCLM presentation, management and survival outcomes has been published from either the private or public health care sectors in South Africa. This study aimed to address this deficit, reporting on a private sector cohort.

METHODS

A retrospective review of a private health care funder's database from 1 January 2008 to 31 December 2015 was performed. ICD-10 diagnosis codes were used to identify CRC and CRCLM. Procedure codes assigned to hospital admissions were used to identify the type of surgical treatment. Chemotherapy was identified by the WHO Anatomical Therapeutic Chemical classification system of medicines. Treatment patterns were assessed and five-year overall survival (OS) was calculated. Survival was estimated using the Kaplan-Meier method, and Cox proportional-hazards regression was used for between group survival comparisons.

RESULTS

Six hundred and one (601) of 3 412 patients presenting with CRC (17.6%) were diagnosed with CRCLM at presentation or during the follow-up period. Sixty patients with CRCLM (10.0%) underwent resection of the primary CRC and liver resection for metastases, 281 (46.8%) underwent CRC resection only, 180 (30%) received chemotherapy only, and 47 (7.8%) received no treatment. Five-year OS for these groups were 57.3%, 15.6%, 9.8% and 0% respectively.

CONCLUSION

Five-year OS of the various CRCLM treatment pathways in a South African private sector population compares to results published in international series. However, a smaller proportion of patients with CRCLM underwent liver resection, compared to international studies.

Effectiveness of Text Message Reminders on Adherence to Inhaled Therapy in Patients With Asthma: Prospective Multicenter Randomized Clinical Trial

Background

Poor adherence to inhaled medication in asthma patients is of great concern. It is one of the main reasons for inadequate asthma control.

Objective

The goal of the research was to determine if motivational messages using short message service (SMS, or text) improved adherence to inhaled medication in patients with asthma.

Methods

A prospective multicenter randomized parallel-group clinical trial was conducted in 10 asthma clinics in Spain. Adherence was assessed with electronic monitors (Smartinhaler, Adherium Ltd) connected to inhalers. Patients in the SMS group received psychologist-developed motivational messages every 3 days for 6 months.

Results

There were 53 patients in the SMS group and 88 patients in the control group. After 6 months, mean electronic adherence was 70% (SD 17%) in the intervention group and 69% (SD 17%) in the control group (P=.82). Significant differences between the study groups in morning and evening adherence to inhaled therapy, asthma control, exhaled nitric oxide levels, or improvement of lung functions were not observed.

Conclusions

Motivational messages were not useful to improve adherence to inhaled asthma medication compared with usual care.

Modeling the Transport of Human Rotavirus and Norovirus in Standardized and in Natural Soil Matrix-Water Systems

We modeled Group A Rotavirus (RVA) and Norovirus genogroup II (GII NoV) transport experiments in standardized (crystal quartz sand and deionized water with adjusted pH and ionic strength) and natural soil matrix-water systems (MWS). On the one hand, in the standardized MWS, Rotavirus and Norovirus showed very similar breakthrough curves (BTCs), showing a removal rate of 2 and 1.7 log₁₀, respectively. From the numerical modeling of the experiment, transport parameters of the same order of magnitude were obtained for both viruses. On the other hand, in the natural MWS, the two viruses show very different BTCs. The Norovirus transport model showed significant changes; BTC showed a removal rate of 4 log₁₀, while Rotavirus showed a removal rate of 2.6 log₁₀ similar to the 2 log₁₀ observed on the standardized MWS. One possible explanation for this differential behavior is the difference in the isoelectric point value of these two viruses and the increase of the ionic strength on the natural MWS.

P727 Unexpected ventricular aneurysm: further ischemic aetiology

Introduction

Ventricular aneurysm is an infrequent complication of myocardial infarction. In absence of an ischemic event, alternative aetiologies include: thoracic trauma, hypertrophic cardiomyopathy, myocarditis, Chagas disease, cardiac sarcoidosis or arrythmogenic cardiomyopathy. In the absence of any of the previous, congenital aneurysm diagnosis is made.

Case

We present the case of 57-year-old man referred to cardiology department because a new onset of atrial fibrillation with left bundle branch block. Past medical history included high blood pressure and dyslipidaemia without any history or smoking, alcohol consumption or any other toxic abuse. No chest pain, shortness of breath or other significant symptoms were reported. Physical examination was unremarkable except for an arrhythmic pulse at 85-90 bpm.

Echocardiogram showed moderate dilated left ventricle with mild-moderate LV dysfunction (EF 40% ) with a septal aneurysm of 2.4x1cm (Picture A). A coronary CT was performed that ruled out coronary heart disease and confirmed the presence of the septal aneurysm (Picture B). To better characterize this image, a cardiac magnetic resonance (CMR) was performed. Moderate dilated LV with significant dysfunction (EF 31%) was reported. A septal aneurysm of 13 x 22 x 33 mm composed of a 2.8 m thin wall of true myocardial tissue was documented (picture C and D-late gadolinium enhance). No myocardial delayed enhancement was detected in any area of the LV. Moreover, no signs of myocardial non compaction, arrythmogenic cardiomyopathy, hypertrophic cardiomyopathy or myocarditis were seen. Chagas serology as well as sarcoidosis diagnosis work up were negative. Patient denied any thoracic traumatism. Congenital aneurysm diagnosis was finally established.

Electrical cardioversion was performed after 1 month of correct oral anticoagulation and heart failure treatment was started. Case was presented in the Heart Team session and a conservative management was decided based on asymptomatic status and absence of ventricular arrhythmias. After 3 years of clinical follow up, the patients is in good status, asymptomatic and in sinus rhythm. Discussion: Congenital ventricular aneurysm is a rare cardiac malformation that arises during the fourth embryonic week. Most frequently, left ventricular aneurysms are found in the apex and the perivalvular area, being the septal location an atypical one. Most patients are asymptomatic but when symptoms occur, they are mostly related to the presence of ventricular arrhythmias. Aneurysm rupture incidence is variable, ranging from 3.7% to 12 % according to the different series. For this reason, surgery is recommended in symptomatic patients. However, management of asymptomatic patients is not clear since prognosis studies are lacking.

Abstract P727 Figure. A.Echo B.-CT C.-CMR. D.-CMR gadolinium

Low Golimumab Trough Levels at Week 6 Are Associated With Poor Clinical, Endoscopic and Histological Outcomes in Ulcerative Colitis Patients: Pharmacokinetic and Pharmacodynamic Sub-analysis of the Evolution Study

BACKGROUND AND AIMS

Golimumab has an established exposure-response relationship in patients with ulcerative colitis [UC]. However, the association of serum golimumab trough levels [TL] with objective markers of disease activity, such as endoscopic and histological activity scores and concentrations of biomarkers, remains less understood. This report describes the relationship of serum golimumab TL at the end of the induction period [Week 6] with clinical, endoscopic, histological, and biomarker parameters.

METHODS

This was an open-label, uncontrolled, prospective and interventional study. Moderate to severely active UC patients naïve to biologic therapy were treated with golimumab. Serum golimumab TL and faecal calprotectin levels were measured at baseline [Week 0 of induction] and Week 6.

RESULTS

A total of 34 patients completed the induction phase [Week 6] and were included in this analysis. Overall, 47.1% and 14.7% of patients achieved clinical response and remission with significantly higher serum golimumab TL in patients with early response or remission [3.7 μg/mL vs 1.3 μg/mL, p = 0.0013; and 3.1 μg/mL vs 1.7 μg/mL, p = 0.0164, respectively]. In addition, golimumab TL were significantly higher in patients achieving histological remission [4.2 μg/mL vs 1.7 μg/mL, p = 0.0049]. Week 6 golimumab TL were inversely correlated with the total Mayo score [rs = -0.546; p = 0.0008], the Mayo endoscopic subscore [rs = -0.381; p = 0.0262], the Geboes histological activity score [rs = -0.464; p = 0.0057], and faecal calprotectin levels [rs = -0.497; p = 0.0044].

CONCLUSIONS

A higher early exposure to golimumab is associated with a better objective response in active UC patients and appears to drive the outcome at Week 6.

P102 Shunting slit ventricles: a comparison of the parieto-occipital vs frontal approach

Objectives

Slit ventricles can be a challenging target during shunt catheter insertion. Traditionally, the frontal approach has been considered optimal. At this centre, routine use of electromagnetic (EM) stereotatic guidance (StealthTM, Medtronic) has enabled a parieto-occipital burr hole approach to the frontal horns. We compare shunt placement and revisions required for patients with slit ventricles who had shunts inserted via a parieto-occipital (P-O) approach vs. frontal shunt.

Design

Retrospective cohort.

Subjects

Patients with slit ventricles and a ventricular shunt inserted using EM guidance between 2012–2018.

Methods

Slit ventricles were defined as <3 mm (widest). Outcome measures included placement accuary and survival using Kaplan-Meier curve.

Results

82 patients (77F:5M) aged 34.9±10.8 years (mean ±SD) had shunts inserted for IIH (n=63), chiari/syrinx (n=8), congenital hydrocephalus (n=10), pseudomeningocoele (n=1). 35 had primary P-O shunts and 46 had frontal shunts. Overall, 94% of cases had the catheter tip sitting in the frontal horn. The P-O approach was just as accurate as the frontal approach. Eight P-O shunts and 9 frontal shunts required revision over a 60 month periods. There was no significant different in shunt survival between the two approaches (p=0.99).

Conclusions

EM guided placement has enabled the P-O approach to be as safe and with equivalent survival to frontal approach. The accuracy of shunt placement between the two approaches was equivocal.

TM3-3 Correlation of lumbar puncture opening pressure with 24 hours intraparenchymal ICP monitoring: the effects of position on ICP

Objectives

Lumbar Puncture opening pressure in lateral decubitus has been considered the gold standard method of intracranial pressure (ICP) measurement for many years. The use of continuous intraparenchymal ICP monitoring is more recent and there is no consensus regarding what can be considered normal ICP with this method of measurement. A conversion factor between lumbar puncture opening pressure and 24 hours ICP monitoring could provide a better insight on the interpretation of ICP. This study investigates the differences between 24 hours ICP and ICP in lumbar puncture position.

Design

Single centre prospective observational study.

Subjects

Fifty-four patients (42F:12M, mean age 38±12 years) were included.

Methods

Patients investigated with 24 hours ICP monitoring who underwent a short exercise battery during the monitoring period were included. The exercise battery was standardised; patients were asked to stay in a supine, sitting, standing and lumbar puncture position for 2 min each.Mean ICP and pulse amplitude were calculated for each position.

Results

The mean 24 hours ICP was 4.9 mmHg (±6.9 SD) and the mean ICP in lumbar puncture position was 14.1 mmHg (±8.9 SD). The average increase in lumbar puncture position was 9.1 mmHg (±5.9 SD). Patients with normal lumbar puncture position ICP (<12 mmHg) had an average 24 hours ICP of 1.4 mmHg (±2.81 SD).

Conclusions

Our results suggest that ICP measured in lumbar puncture position is on average 9.1 mmHg higher than 24 hours ICP results. Larger studies will be needed to confirm these findings.

A Simple Score for Future Risk Prediction in Patients with Controlled Asthma Who Undergo a Guidelines-Based Step-Down Strategy

BACKGROUND

The minimum controlling dose of treatment must be established in patients with asthma, but the outcome of step-down is unpredictable.

OBJECTIVE

To identify factors associated with risk of control loss when stepping down asthma treatment and to develop a score to predict this risk.

METHODS

A prospective, multicenter study including adults with well-controlled asthma was performed. Treatment was stepped up or stepped down over a 12-month period to maintain asthma control. We determined associations between clinical and functional variables and step-down failure. Finally, we derived a score to predict loss of control in 1 cohort and validated it in an independent cohort.

RESULTS

The derivation cohort consisted of 228 patients; 218 completed at least 1 step-down episode and a total of 495 step-down episodes were evaluated. A medical-record documented postbronchodilator spirometry result of <70% forced expiratory volume in 1 second (FEV₁)/forced vital capacity (odds ratio [OR] = 2.08; 95% confidence interval [CI]: 1.26-3.43), current FEV₁ < 80% (OR = 1.80; 95% CI: 1.03-3.14), ≥1 severe exacerbation in the previous 12 months (OR = 2.43; 95% CI: 1.48-4.01), and Asthma Control Test score < 25 (OR = 2.30; 95% CI: 1.35-3.92) were independently associated with failure. The score showed an area under the curve of 0.690 (95% CI: 0.633-0.747; P < .05) in the derivation cohort and 0.76 (95% CI: 0.643-0.882; P < .001) in a validation cohort of 114 patients. A score <4.5 implies a low risk of failure (<20%), whereas a score >8 implies a high risk (>40%).

CONCLUSION

This score can facilitate the prediction of step-down failure before medication taper in patients with well-controlled asthma.

Evaluation of Bacterial Contamination as an Indicator of Viral Contamination in a Sedimentary Aquifer in Uruguay

In Uruguay, groundwater is frequently used for agricultural activities, as well as for human consumption in urban and rural areas. As in many countries worldwide, drinking water microbiological quality is evaluated only according to bacteriological standards and virological analyses are not mentioned in the legislation. In this work, the incidence of human viral (Rotavirus A, Norovirus GII, and human Adenovirus) and bacterial (total and thermotolerant coliform and Pseudomonas aeruginosa) contamination in groundwater in the Salto district, Uruguay, as well as the possible correlation between these groups of microorganisms, was studied. From a total of 134 groundwater samples, 42 (32.1%) were positive for Rotavirus, only 1 (0.7%) for both Rotavirus and Adenovirus, and 96 (72.6%) samples were positive for bacterial indicators. Results also show that Rotavirus presence was not associated with changes in chemical composition of the aquifer water. Bacteriological indicators were not adequate to predict the presence of viruses in individual groundwater samples (well scale), but a deeper spatial-temporal analysis showed that they are promising candidates to assess the viral contamination degree at aquifer scale, since from the number of wells with bacterial contamination the number of wells with viral contamination could be estimated.

Optimisation of imaging protocols in interventional cardiology: impact on patient doses

The purpose of this work is to evaluate the impact of the imaging protocol as part of the optimisation of patient doses in interventional cardiology. This paper reports the results of an initial study to refine the existing fluoroscopy and cine settings, evaluates a new imaging protocol by measuring the image quality and phantom entrance air kerma values, and tests the clinical implementation of the new protocol in terms of the reduction in patient doses and the impact on clinical images. The initial study developed a new fluoroscopy mode using 7.5 frames s^-1 (instead of the previous 15 frames s^-1) with a similar dose/frame and a reduction of approximately 26% in dose/frame for the existing standard cine mode. For the new imaging protocol, the reduction in entrance air kerma was characterised for water depths of 16, 20, and 24 cm and the image quality was evaluated using a Leeds test object. A reduction in dose of around 50% was observed for the low fluoroscopy mode and an 18%-38% reduction was measured for cine. The image quality was unchanged in fluoroscopy mode and did not suffer noticeable alterations in cine mode. In the clinical implementation, cardiologists evaluated the new imaging protocol in clinical practice and cooperated with medical physicists to ensure full optimisation. The image quality criteria evaluated the ability to visualise the standard coronary arteries and small vessels (<2 mm), and the proper visualisation of the heart and diaphragm. A total of 1635 interventional cardiac procedures were assessed. The median kerma-area product exhibited a reduction of 37% for CA and 43% for PTCA examinations, and the quality of the clinical images was considered sufficient for standard clinical practice.

Molecular and hydrodynamic properties of human epidermal growth factor receptor HER2 extracellular domain and its homodimer: Experiments and multi-scale simulations

BACKGROUND

In a broad range of human carcinomas gene amplification leads to HER2 overexpression, which has been proposed to cause spontaneous dimerization and activation in the absence of ligand. This makes HER2 attractive as a therapeutic target. However, the HER2 homodimerization mechanism remains unexplored. It has been suggested that the "back-to-back" homodimer does not form in solution. Notwithstanding, very recently the crystal structure of the HER2 extracellular domain homodimer formed with a "back-to-head" interaction has been resolved. We intend to explore the existence of such interactions.

METHODS

A combination of experiments, molecular dynamics and hydrodynamic modeling were used to monitor the transport properties of HER2 in solution.

RESULTS & CONCLUSIONS

We have detected the HER2 extracellular domain homodimer in solution. The results show a high degree of molecular flexibility, which ultimately leads to quite higher values of the intrinsic viscosity and lower values of diffusion coefficient than those corresponding to globular proteins. This flexibility obeys to the open conformation of the receptor and to the large fluctuations of the different domains. We also report that for obtaining the correct hydrodynamic constants from the modeling one must consider the glycosylation of the systems.

GENERAL SIGNIFICANCE

Conformational features of epidermal growth factor receptors regulate their hydrodynamic properties and control their activity. It is essential to understand the dynamics of these systems and the role of the specific domains involved. To find biophysical correlations between dynamics and macroscopic transport properties is of general interest for researches working in this area. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue.

Occupational dose reduction in cardiac catheterisation laboratory: a randomised trial using a shield drape placed on the patient

The aim of this study was to evaluate the occupational radiation dose in interventional cardiology by using a shielding drape on the patient. A random study with and without the protective material was conducted. The following control parameters were registered: demographic data, number of stents, contrast media volume, fluoroscopy time, number of cine images, kerma-area product and cumulative air kerma. Occupational dose data were obtained by electronic active dosemeters. No statistically significant differences in the analysed control parameters were registered. The median dose value received by the interventional cardiologist was 50% lower in the group with a shielding drape with a statistically significant p-value <0.001. In addition, the median value of the maximum scatter radiation dose was 31% lower in this group with a statistically significant p-value <0.001. This study showed that a shielding drape is a useful tool for reducing the occupational radiation dose in a cardiac catheterisation laboratory.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point-of-care quantitative test with two established ELISA assays

BACKGROUND

Therapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA-based, with a turnaround time of approximately 8 h, and delaying the target dosage adjustment to the following infusion.

AIM

To validate the first point-of-care IFX quantification device available in the market - the Quantum Blue Infliximab assay (Buhlmann, Schonenbuch, Switzerland) - by comparing it with two well-established methods.

METHODS

The three methods were used to assay the IFX concentration of spiked samples and of the serum of 299 inflammatory bowel diseases (IBD) patients undergoing IFX therapy.

RESULTS

The point-of-care assay had an average IFX recovery of 92%, being the most precise among the tested methods. The Intraclass Correlation Coefficients of the point-of-care IFX assay vs. the two ELISA-based established methods were 0.889 and 0.939. Moreover, the accuracy of the point-of-care IFX compared with each of the two reference methods was 77% and 83%, and the kappa statistics revealed a substantial agreement (0.648 and 0.738).

CONCLUSIONS

The Quantum Blue IFX assay can successfully replace the commonly used ELISA-based IFX quantification kits. This point-of-care IFX assay is able to deliver the results within 15 min makes it ideal for an immediate target concentration adjusted dosing. Moreover, it is a user-friendly desktop device that does not require specific laboratory facilities or highly specialised personnel.

Analysis of fracture healing in osteopenic bone caused by disuse: experimental study

Osteoporosis has become a serious global public health issue. Hence, osteoporotic fracture healing has been investigated in several previous studies because there is still controversy over the effect osteoporosis has on the healing process. The current study aimed to analyze two different periods of bone healing in normal and osteopenic rats. Sixty, 7-week-old female Wistar rats were randomly divided into four groups: unrestricted and immobilized for 2 weeks after osteotomy (OU2), suspended and immobilized for 2 weeks after osteotomy (OS2), unrestricted and immobilized for 6 weeks after osteotomy (OU6), and suspended and immobilized for 6 weeks after osteotomy (OS6). Osteotomy was performed in the middle third of the right tibia 21 days after tail suspension, when the osteopenic condition was already set. The fractured limb was then immobilized by orthosis. Tibias were collected 2 and 6 weeks after osteotomy, and were analyzed by bone densitometry, mechanical testing, and histomorphometry. Bone mineral density values from bony calluses were significantly lower in the 2-week post-osteotomy groups compared with the 6-week post-osteotomy groups (multivariate general linear model analysis, P<0.000). Similarly, the mechanical properties showed that animals had stronger bones 6 weeks after osteotomy compared with 2 weeks after osteotomy (multivariate general linear model analysis, P<0.000). Histomorphometry indicated gradual bone healing. Results showed that osteopenia did not influence the bone healing process, and that time was an independent determinant factor regardless of whether the fracture was osteopenic. This suggests that the body is able to compensate for the negative effects of suspension.

Expert knowledge integration in the data mining process with application to cardiovascular risk assessment

The data mining process, when applied to clinical databases, suffers from critical data problems, from noisy acquisitions to missing or incomplete data points. Expert knowledge, in the form of practitioners' experience and clinical guidelines, is already used to manually correct some of these problems, while enhancing expert's confidence in such systems. In this work, we propose the Knowledge-Biased Tree (KB3), a knowledge biased decision tree inducer that is able to exploit IF THEN rules to guide the tree inducing process. The KB3 approach was tested against its unbiased counterpart, the C5.0 algorithm in the cardiovascular risk assessment task. Using a clinical dataset provided by the hospital of Sta Cruz (Lisbon, Portugal) the performance of the proposed algorithm is compared against the unbiased C5.0 and the state of the art risk score used in clinical practice (GRACE risk score).