A Perovskite-Graphene Device for X-ray Detection

This study examines a perovskite-based graphene field effect transistor (P-GFET) device for X-ray detection. The device architecture consisted of a commercially available GFET-S20 chip, produced by Graphenea, with a layer of methylammonium lead iodide (MAPbI3) perovskite spin coated onto the top of it. This device was exposed to the field of a molybdenum target X-ray tube with beam settings between 20-60 kVp (X-ray tube voltage) and 30-300 uA (X-ray tube current). Dose measurements were taken with an ion-chamber and thermo-luminescent dosimeters and used to determine the sensitivity of the device as a function of the X-ray tube voltage and current, as well as source-drain voltage. The X-ray tube was also simulated in this work with GEANT4 and MCNP to determine the dose rate and power incident on the device during irradiation. These simulations were then used to determine the responsivity as a function of the X-ray tube voltage and current, as well as the source-drain voltage. Overall, a strong positive correlation between sensitivity and source-drain voltage was found. Conversely, the sensitivity was found to decrease - roughly exponentially - as a function of both the X-ray tube current and energy. Similar trends were seen with responsivity. We report the models used for the study as well as address the feasibility of the device as a low-energy (< 70 keV) X-ray photon detector.

Novel paradigm enables accurate monthly gestational screening to prevent congenital toxoplasmosis and more

Background

Congenital toxoplasmosis is a treatable, preventable disease, but untreated causes death, prematurity, loss of sight, cognition and motor function, and substantial costs worldwide.

Methods/Findings

In our ongoing USA feasibility/efficacy clinical trial, data collated with other ongoing and earlier published results proved high performance of an Immunochromatographic-test(ICT) that enables accurate, rapid diagnosis/treatment, establishing new paradigms for care. Overall results from patient blood and/or serum samples tested with ICT compared with gold-standard-predicate-test results found ICT performance for 4606 sera/1876 blood, 99.3%/97.5% sensitive and 98.9%/99.7% specific. However, in the clinical trial the FDA-cleared-predicate test initially caused practical, costly problems due to false-positive-IgM results. For 58 persons, 3/43 seronegative and 2/15 chronically infected persons had false positive IgM predicate tests. This caused substantial anxiety, concerns, and required costly, delayed confirmation in reference centers. Absence of false positive ICT results contributes to solutions: Lyon and Paris France and USA Reference laboratories frequently receive sera with erroneously positive local laboratory IgM results impeding patient care. Therefore, thirty-two such sera referred to Lyon's Reference laboratory were ICT-tested. We collated these with other earlier/ongoing results: 132 of 137 USA or French persons had false positive local laboratory IgM results identified correctly as negative by ICT. Five false positive ICT results in Tunisia and Marseille, France, emphasize need to confirm positive ICT results with Sabin-Feldman-Dye-test or western blot. Separate studies demonstrated high performance in detecting acute infections, meeting FDA, CLIA, WHO ASSURED, CEMark criteria and patient and physician satisfaction with monthly-gestational-ICT-screening.

Conclusions/Significance

This novel paradigm using ICT identifies likely false positives or raises suspicion that a result is truly positive, rapidly needing prompt follow up and treatment. Thus, ICT enables well-accepted gestational screening programs that facilitate rapid treatment saving lives, sight, cognition and motor function. This reduces anxiety, delays, work, and cost at point-of-care and clinical laboratories.

Author’s Summary

Toxoplasmosis is a major health burden for developed and developing countries, causing damage to eyes and brain, loss of life and substantial societal costs. Prompt diagnosis in gestational screening programs enables treatment, thereby relieving suffering, and leading to > 14-fold cost savings for care. Herein, we demonstrate that using an ICT that meets WHO ASSURED-criteria identifying persons with/without antibody to Toxoplasma gondii in sera and whole blood with high sensitivity and specificity, is feasible to use in USA clinical practice. We find this new approach can help to obviate the problem of detection of false positive anti- T.gondii IgM results for those without IgG antibodies to T.gondii when this occurs in present, standard of care, predicate USA FDA cleared available assays. Thus, this accurate test facilitates gestational screening programs and a global initiative to diagnose and thereby prevent and treat T.gondii infection. This minimizes likelihood of false positives (IgG and/or IgM) while maintaining maximum sensitivity. When isolated IgM antibodies are detected, it is necessary to confirm and when indicated continue follow up testing in ∼2 weeks to establish seroconversion. Presence of a positive ICT makes it likely that IgM is truly positive and a negative ICT makes it likely that IgM will be a false positive without infection. These results create a new, enthusiastically-accepted, precise paradigm for rapid diagnosis and validation of results with a second-line test. This helps eliminate alarm and anxiety about false-positive results, while expediting needed treatment for true positive results and providing back up distinguishing false positive tests.

Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery

BACKGROUND

Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort.

METHODS

Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups.

RESULTS

The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status.

CONCLUSION

The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

Clinical utility of comprehensive circulating tumor DNA genotyping compared with standard of care tissue testing in patients with newly diagnosed metastatic colorectal cancer

BACKGROUND

Comprehensive biomarker testing is essential in selecting optimal treatment for patients with metastatic colorectal cancer (mCRC); however, incomplete genotyping is widespread, with most patients not receiving testing for all guideline-recommended biomarkers, in part due to reliance on burdensome sequential tissue-based single-biomarker tests with long waiting times or availability of only archival tissue samples. We aimed to demonstrate that liquid biopsy, associated with rapid turnaround time (TAT) and lower patient burden, effectively identifies guideline-recommended biomarkers in mCRC relative to standard of care (SOC) tissue testing.

PATIENTS AND METHODS

Prospectively enrolled patients with previously untreated mCRC undergoing physician discretion SOC tissue genotyping submitted pretreatment blood samples for comprehensive circulating tumor DNA (ctDNA) analysis with Guardant360 and targeted RAS and BRAF analysis with OncoBEAM.

RESULTS

Among 155 patients, physician discretion SOC tissue genotyping identified a guideline-recommended biomarker in 82 patients, versus 88 identified with comprehensive ctDNA (52.9% versus 56.8%, noninferiority demonstrated down to α = 0.005) and 69 identified with targeted PCR ctDNA analysis (52.9% versus 44.5%, noninferiority rejected at α = 0.05). Utilizing ctDNA in addition to tissue increased patient identification for a guideline-recommended biomarker by 19.5% by rescuing those without tissue results either due to tissue insufficiency, test failure, or false negatives. ctDNA median TAT was significantly faster than tissue testing when the complete process from sample acquisition to results was considered (median 10 versus 27 days, P < 0.0001), resulting in accelerated biomarker discovery, with 52.0% biomarker-positive patients identified by ctDNA versus 10.2% by SOC tissue 10 days after sample collection (P < 0.0001).

CONCLUSIONS

Comprehensive ctDNA genotyping accurately identifies guideline-recommended biomarkers in patients with mCRC at a rate at least as high as SOC tissue genotyping, in a much shorter time. Based on these findings, the addition of ctDNA genotyping to clinical practice has significant potential to improve the care of patients with mCRC.

Operationalizing Integrated Water Resource Management in Latin America: Insights from Application of the Freshwater Health Index

Water crises in Latin America are more a consequence of poor management than resource scarcity. Addressing water management issues through better coordination, identification of problems and solutions, and agreement on common objectives to operationalize integrated water resources management (IWRM) could greatly improve water governance in the region. Composite indices have great potential to help overcome capacity and information challenges while supporting better IWRM. We applied one such index, the Freshwater Health Index (FHI) in three river basins in Latin America (Alto Mayo, Perú; Bogotá, Colombia; and Guandu, Brazil) to assess freshwater ecosystem vitality, ecosystem services, and the water governance system in place. The approach included convening management agencies, water utilities, planning authorities, local NGOs and industries, community groups and researchers to co-implement the FHI. The results provide detailed information on the ecological integrity of each basin and the sustainability of the ecosystem services being provided. All three basins show very low scores for governance and stakeholder engagement, thus improving both in the region should be a priority. The results also shed light on how the FHI framework can help inform decision-making to improve IWRM implementation by facilitating stakeholder engagement while contributing to coordination, identification of problems and solutions as well as agreement on common objectives. Because implementation of IWRM is part of the solution for the United Nations Sustainable Development Goal (SDG) 6.5 ("By 2030, implement IWRM at all levels, including through transboundary cooperation as appropriate"), our case studies can serve as examples to other Latin American countries to achieve SDG 6.5.

Latin American consensus on the quality indicators for comprehensive care clinics for patients with inflammatory bowel disease: PANCCO-GETECCU

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic and incurable entity. The aim of the Pan American Crohn's and Colitis Organisation (PANCCO) is to create awareness of IBD, with special emphasis on Latin America, and the primary objective of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU, the Spanish acronym) is to obtain the accreditation of the clinical and therapeutic criteria for the diagnosis and treatment of IBD.

AIM

To carry out a consensus for evaluating the approval criteria that a Comprehensive Care Clinic for Latin American IBD patients must meet, to be considered a center of excellence.

MATERIALS AND METHODS

Fourteen clinical experts participated in the consensus. They were made up of specialists in gastroenterology, with broad clinical experience, spanning several years, in managing the care of a large number of patients with IBD, as well as advanced specialists in IBD. Thirteen of the participants came from 11 Latin American countries (Argentina, Brazil, Colombia, Dominican Republic, Ecuador, Guatemala, Mexico, Peru, Puerto Rico, Uruguay, and Venezuela) that have IBD clinics. An expert from Spain, representing the GETECCU, provided the methodologic support. The consensus consisted of 52 statements divided into three sections: 1) Structure indicators, 2) Process indicators, and 3) Result indicators. The Delphi panel method was applied.

RESULTS

The present Latin American consensus describes the quality indicators that a Comprehensive Care Clinic for IBD patients must meet, to be considered a center of excellence, taking into account the needs of our region.

CONCLUSIONS

This is the first Latin American consensus, jointly carried out by the PANCCO and GETECCU, to present accreditation standards for centers of excellence in the care of patients with IBD.

Kisspeptin treatment induces gonadotropic responses and rescues ovulation in a subset of preclinical models and women with polycystic ovary syndrome

STUDY QUESTION

Can kisspeptin treatment induce gonadotrophin responses and ovulation in preclinical models and anovulatory women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Kisspeptin administration in some anovulatory preclinical models and women with PCOS can stimulate reproductive hormone secretion and ovulation, albeit with incomplete efficacy.

WHAT IS KNOWN ALREADY

PCOS is a prevalent, heterogeneous endocrine disorder, characterized by ovulatory dysfunction, hyperandrogenism and deregulated gonadotrophin secretion, in need of improved therapeutic options. Kisspeptins (encoded by Kiss1) are master regulators of the reproductive axis, acting mainly at GnRH neurons, with kisspeptins being an essential drive for gonadotrophin-driven ovarian follicular maturation and ovulation. Altered Kiss1 expression has been found in rodent models of PCOS, although the eventual pathophysiological role of kisspeptins in PCOS remains unknown.

STUDY DESIGN, SIZE, DURATION

Gonadotrophin and ovarian/ovulatory responses to kisspeptin-54 (KP-54) were evaluated in three preclinical models of PCOS, generated by androgen exposures at different developmental windows, and a pilot exploratory cohort of anovulatory women with PCOS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Three models of PCOS were generated by exposure of female rats to androgens at different periods of development: PNA (prenatal androgenization; N = 20), NeNA (neonatal androgenization; N = 20) and PWA (post-weaning androgenization; N = 20). At adulthood (postnatal day 100), rats were subjected to daily treatments with a bolus of KP-54 (100 μg/kg, s.c.) or vehicle for 11 days (N = 10 per model and treatment). On Days 1, 4, 7 and 11, LH and FSH responses were assessed at different time-points within 4 h after KP-54 injection, while ovarian responses, in terms of follicular maturation and ovulation, were measured at the end of the treatment. In addition, hormonal (gonadotrophin, estrogen and inhibin B) and ovulatory responses to repeated KP-54 administration, at doses of 6.4-12.8 nmol/kg, s.c. bd for 21 days, were evaluated in a pilot cohort of anovulatory women (N = 12) diagnosed with PCOS, according to the Rotterdam criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

Deregulated reproductive indices were detected in all PCOS models: PNA, NeNA and PWA. Yet, anovulation was observed only in NeNA and PWA rats. However, while anovulatory NeNA rats displayed significant LH and FSH responses to KP-54 (P < 0.05), which rescued ovulation, PWA rats showed blunted LH secretion after repeated KP-54 injection and failed to ovulate. In women with PCOS, KP-54 resulted in a small rise in LH (P < 0.05), with an equivalent elevation in serum estradiol levels (P < 0.05). Two women showed growth of a dominant follicle with subsequent ovulation, one woman displayed follicle growth but not ovulation and desensitization was observed in another patient. No follicular response was detected in the other women.

LIMITATIONS, REASONS FOR CAUTION

While three different preclinical PCOS models were used in order to capture the heterogeneity of clinical presentations of the syndrome, it must be noted that rat models recapitulate many but not all the features of this condition. Additionally, our pilot study was intended as proof of principle, and the number of participants is low, but the convergent findings in preclinical and clinical studies reinforce the validity of our conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

Our first-in-rodent and -human studies demonstrate that KP-54 administration in anovulatory preclinical models and women with PCOS can stimulate reproductive hormone secretion and ovulation, albeit with incomplete efficacy. As our rat models likely reflect the diversity of PCOS phenotypes, our results argue for the need of personalized management of anovulatory dysfunction in women with PCOS, some of whom may benefit from kisspeptin-based treatments.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research agreements between Ferring Research Institute and the Universities of Cordoba and Edinburgh. K.S. was supported by the Wellcome Trust Scottish Translational Medicine and Therapeutics Initiative (STMTI). Some of this work was undertaken in the MRC Centre for Reproductive Health which is funded by the MRC Centre grant MR/N022556/1. M.T.-S. is a member of CIBER Fisiopatología de la Obesidad y Nutrición, which is an initiative of Instituto de Salud Carlos III. Dr Mannaerts is an employee of Ferring International PharmaScience Center (Copenhagen, Denmark), and Drs Qi, van Duin and Kohout are employees of the Ferring Research Institute (San Diego, USA). Dr Anderson and Dr Tena-Sempere were recipients of a grant support from the Ferring Research Institute, and Dr Anderson has undertaken consultancy work and received speaker fees outside this study from Merck, IBSA, Roche Diagnostics, NeRRe Therapeutics and Sojournix Inc. Dr Skorupskaite was supported by the Wellcome Trust through the Scottish Translational Medicine and Therapeutics Initiative 102419/Z/13/A. The other authors have no competing interest.

FRI0546 GENDER DIFFERENCES OF RHEUMATIC DISEASES IN MEXICAN POPULATION: DATA FROM THE MEXICAN BIOLOGICS REGISTRY

Background:

Most autoimmune diseases are more prevalent in women. Symptom severity, disease progression, response to therapy and overall survival differ between males and females with rheumatic diseases.

Objectives:

To identify the characteristics of autoimmune diseases presentation and treatment between male and female population using information from the Mexican Adverse Events Registry (BIOBADAMEX).

Methods:

BIOBADAMEX is a Mexican ongoing cohort that collects the information of patients using biologic and biosimilar drugs since 2016. For this study we included all patients enrolled in the registry and compared baseline clinical and disease characteristics, treatment and presence of adverse events between genders. We used logistic regression to analyze univariable associations.

Results:

A total of 655 participants were analysed, of which 82% were female (Table 1). We found women were older with a median of 53 years compared to 46 years in men (OR 1.02, CI 1.0-1.1). Smoking was higher in men (16%) compared to women (5%), (OR 0.3, CI 0.2-0.6). Women had longer disease duration, 9 years compared to 7 years in men (OR 1, CI 1.0-1.1). Rheumatoid arthritis (RA) was more prevalent in women (OR 2.7, CI 1-6.9), while ankylosing spondylitis (AS) and psoriatic arthritis (PsA) were more prevalent in men (OR 0.2, CI 0.1-0.4, and OR 0.3, CI 0.1-0.9 respectively). Women had more comorbidities than men (OR 1.8, CI 1.1-2.8) and used steroids more frequently (OR 1.7, CI 1.1-2.7). Differences in disease activity were not found, however we noticed high activity scores among participants.

Table 1.

Baseline characteristics in the cohort by sex

Womenn=532 (82%)Menn=123 (18%)UnivariableaOR(95%CI)Age, median (IQR)53 (44-60)47 (34-55)1.02 (1.0-1.1)*Body Mass Index, median (IQR)27 (23-31)26 (23-30)1.0 (0.9-1.1)Smoking, n(%)28 (5)18 (16)0.3 (0.2- 0.6)*Disease duration, median (IQR)9 (4-16)7 (2-13)1.0 (1.0-1.1)*Diagnosis, n(%): RA414 (78)37 (30)2.4 (1.0-5.7)* AIJ12 (2)5 (4)0.5 (0.1-1.9) AS37 (7)56 (46)0.1 (0.1-0.4)* PsA19 (4)15 (12)0.3 (0.1-0.8)* SLE17 (3)3 (2)1.2 (0.3-5.2) Others33 (6)7 (6)1Disease Activity indexes, median (IQR) DAS28a4.9 (3.6-5.9)4.9 (3.0-5.9)1.1 (0.9-1.3) BASDAIb4.8 (2.9-8)5.3 (2.8-7.5)0.9 (0.8- 1.1) ASDASc3.2 (1.9-4.5)3.9 (2.5-4.7)0.8 (0.6-1.2) SLEDAId14.5 (5.0-19.5)25 (25.0-31.0)0.6 (0.4-1.1)High blood pressure, n(%)77 (15)14 (12)1.3 (0.7-2.4)Diabetes mellitus, n(%)46 (9)7 (6)1.5 (0.7-3.5)High cholesterol, n(%)41 (8)8 (7)1.2 (0.4-2.6)Other comorbidities, n(%):173 (33)26 (21)1.8 (1.1 -2.8)*Use of previous biologic, n(%):216 (40)44 (36)1.2 (0.8- 1.8)Use of steroids, n(%):215 (42)34 (29)1.7 (1.1 -2.7)*Use of DMARD, n(%):418 (79)89 (72)1.4 (0.9-2.2)Adverse eventsb, n(%):69 (13)14 (11)1.2 (0.7-2.1) Severeb, n(%):12 (17)3 (21)0.8 (0.2-3.1)

Univariable logistic regression analysis. *p<0.05.an=469,bn=99,cn=71,dn=19,

Table 1.

Analysis of association between change (Δ) in FMD and relevant parameters by univariate and multivariate linear regression analysis.

UnivariateRho (p)MultivariateBeta (p)Δ FMD (%)(r2=0.30)ChangeADMA (µmol/l)-0.63 (<0.001)-0.25 (0.01)MDA (nmol/ml)-0.58 (<0.001)-0.18 (0.02)SOD (U/ml)0.48 (<0.001)NSGSH (U/ml)0.02 (0.75)NSHOMA-0.21 (0.001)NSeGFR (ml/min/ 1.73 m2)-0.03 (0.62)NShsCRP (mg/l)-0.45 (<0.001)NSPTX3 (ng/ml)-0.49 (<0.001)-0.21 (0.01)SBP (mmHg)-0.26 (<0.001)NSDBP (mmHg)-0.11 (0.12)NSHemoglobin (g/dl)0.07 (0.32)NSTotal Cholesterol (mg/dl)-0.05 (0.49)NSTriglyceride (mg/dl)-0.11 (0.12)NSLDL (mg/dl)-0.12 (0.07)NSHDL (mg/dl)0.02 (0.82)NSHbA1c (%)-0.26 (<0.001)NSFigure 1.

Scatter-plot graphs between FMD and ADMA, MDA, CuZn-SOD, PTX-3.

Conclusion:

In our study we found sex differences regarding age and disease duration, being higher in women. As expected, the prevalence of RA was higher in women and AS and PsA in men. Overall, women used more steroids than men. An interesting finding was that patients had high disease activity. Future longitudinal analyses will allow us to analyse sex differences in disease progression and treatment response.

References:

[1] Ortona E et al. Ann Ist Super Sanita 2016;52(2):205-12

[2] Ngo ST et al. Front Neuroendocrinol 2014;3(3):347-69

Disclosure of Interests:

Vijaya Rivera Teran: None declared, Deshire Alpizar-Rodriguez: None declared, Sandra Sicsik: None declared, Fedra Irazoque-Palazuelos Consultant of: Bristol-Myers Squibb, Janssen, Pfizer Inc, Roche and UCB, Dafhne Miranda: None declared, David Vega-Morales: None declared, Julio Cesar Casasola: None declared, Sandra Carrilo: None declared, angel castillo: None declared, Sergio Duran Barragan: None declared, Omar Muñoz: None declared, Aleni Paz: None declared, Angélica Peña: None declared, Alfonso Torres: None declared, Daniel Xavier Xibille Friedmann Consultant of: Lilly, Abbvie, Speakers bureau: Lilly, Abbvie, Azucena Ramos: None declared, José Francisco Moctezuma: None declared, Francisco Aceves: None declared, Estefania Torres: None declared, Natalia Santana: None declared, Miguel Vazquez: None declared, Erick Zamora: None declared, Francisco Guerrero: None declared, Claudia Zepeda: None declared, Melanea Rivera: None declared, Kitzia Alvarado: None declared, Cesar Francisco Pacheco Tena: None declared

High prevalence of asymptomatic COVID-19 in hemodialysis. Daily learning during first month of COVID-19 pandemic☆

Dialysis patients are a risk group for SARS-CoV2 infection and possibly further complications, but we have little information. The aim of this paper is to describe the experience of the first month of the SARS-Cov2 pandemic in a hospital haemodialysis (HD) unit serving the district of Madrid with the second highest incidence of COVID19 (almost 1000 patients in 100,000 h). In the form of a diary, we present the actions undertaken, the incidence of COVID19 in patients and health staff, some clinical characteristics and the results of screening all the patients in the unit.

We started with 90 patients on HD: 37 (41.1%) had COVID19, of whom 17 (45.9%) were diagnosed through symptoms detected in triage or during the session, and 15 (40.5%) through subsequent screening of those who, until that time, had not undergone SARS-CoV2 PCR testing. Fever was the most frequent symptom, 50% had lymphopenia and 18.4% <95% O₂ saturation. Sixteen (43.2%) patients required hospital admission and 6 (16.2%) died. We found a cluster of infection per shift and also among those using public transport. In terms of staff, of the 44 people involved, 15 (34%) had compatible symptoms, 4 (9%) were confirmed as SARS-Cov2 PCR cases by occupational health, 9 (20%) required some period of sick leave, temporary disability to work (ILT), and 5 were considered likely cases.

Conclusions

We detected a high prevalence of COVID19 with a high percentage detected by screening; hence the need for proactive diagnosis to stop the pandemic. Most cases are managed as outpatients, however severe symptoms are also appearing and mortality to date is 16.2%. In terms of staff, 20% have required sick leave in relation to COVID19.

The use of microindentation for the study of bone properties in type 1 diabetes mellitus patients

Diabetes mellitus is associated with a higher risk of fracture. In this study, we analysed the bone quality of premenopausal women with type 1 diabetes mellitus by microindentation. No differences in bone quality were identified between patients and healthy controls, suggesting that intensive insulin therapy can preserve bone health.

PURPOSE

To compare the bone quality of women with type 1 diabetes mellitus (T1DM) and healthy controls, and to determine the relationship with bone mineral density (BMD).

METHODS

This was a cross-sectional study of 45 premenopausal women with T1DM and 21 healthy controls, matched according to age and BMI. Clinical parameters, BMD and bone tissue mechanical properties (assessed using the bone material strength index [BMSi]) were evaluated in each group using microindentation. In T1DM patients, glycosylated haemoglobin (HbA_1c), the number of hypoglycaemic events and the status of chronic complications were also analysed.

RESULTS

No differences in BMSi or BMD between T1DM patients and healthy controls were identified. In the T1DM patients, the mean HbA_1c was 7.52% ± 1.00% and the mean time elapsed since diagnosis was 22.6 ± 12.2 years. Eight patients (17.7%) met the criteria for metabolic syndrome (MetS), and microvascular complications were present in 12 patients (26.7%). Neither the number of features of MetS present nor the presence of microangiopathy was found to be associated with BMSi.

CONCLUSIONS

T1DM premenopausal patients showed bone tissue properties comparable to those shown by controls. Further larger-scale studies should be conducted to confirm these results.

B-68 The Effect of Bilingualism on Stroop Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) affects neurocognition. Speaking multiple languages can also influence cognitive test performances. We examined the relationship between TBI and monolingualism/bilingualism on a task of attention and response inhibition (Stroop Color Word Test; SCWT).

Method

The sample (N = 96) consisted of 37 healthy controls (19 bilingual; 18 monolingual), 32 acute TBI participants (12 bilingual; 20 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. The SCWT included the word (SCWT-W), color (SCWT-C), and color-word interference (SCWT-I) conditions. All participants passed performance validity testing. 3X2 ANOVAs were conducted to examine the relationship between TBI and monolingualism/bilingualism on SCWT performances.

Results

Group effects (control and TBI groups) were found for all Stroop measures. We found main effects of TBI on SCWT-W, p = .013, ηp² = .09, SCWT-C, p = .001, ηp² = .14, and SCWT-I, p = .022, ηp² = .08, with the controls outperforming acute TBI survivors on SCWT-I, chronic TBI survivors on SCWT-W, and both TBI groups on SCWT-C. We also observed main effects of language for SCWT-C, p = .012, ηp² = .07, and SCWT-I, p = .003, ηp² = .09, with the monolinguals outperforming bilinguals on SCWT-C and SCWT-I. However, no significant interactions between TBI and language were found.

Conclusion

As expected, the control group outperformed TBI survivors on the SCWT. Monolinguals outperformed bilinguals on all Stroop measures except SCWT-W condition. Our findings seem to suggest that monolingual speakers may have better attention and response inhibition abilities that resulted in better SCWT performance.

B-67 The Effect of Bilingualism on Executive Functioning Performance in Traumatic Brain Injury Survivors and Healthy Adults

Objective

Traumatic brain injury (TBI) survivors often exhibit problems with executive function (EF). Language use can also impact EF test performances. We examined the effects of TBI and bilingualism/monolingualism on several EF tests.

Method

The sample (N = 94) consisted of 37 healthy controls (19 bilingual; 18 monolingual), 30 acute TBI participants (10 bilingual; 20 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. Stroop Color-Word (SCW), Delis-Kaplan Executive Function System Letter Fluency (DKEFS-LF), Trail Making Test part B (TMT-B) and a EF global composite (EF-GC) were used to assess EF. All participants passed performance validity testing. 3X2 ANOVAs were conducted to determine the effect of TBI and bilingualism/monolingualism on EF performances.

Results

Main effects were found between groups (control and TBI groups) on SCW, p = .046, ηp² = .07, TMT-B, p = .042, ηp² = .07, and EF-GC, p = .005, ηp² = .13; the 6-month TBI group performed worse than controls on TMT-B and EF-GC. Main effects were found for bilingualism/ monolingualism on SCW, p = .012, ηp² = .07, and TMT-B, p = .034, ηp² = .05; monolingual participants performed better than bilingual participants. No significant interactions between TBI and language were found.

Conclusion

The TBI group underperformed on SCW, TMT-B, and EF-GC compared to controls; relative to monolinguals, bilinguals underperformed on the SCW and TMT-B only. In conclusion, our findings seem to suggest that monolinguals have better cognitive flexibility compared to bilinguals that result in better EF performances.

Chronic kidney disease progression in patients with resistant hypertension subject to 2 therapeutic strategies: Intensification with loop diuretics vs aldosterone antagonists

INTRODUCTION

Actualy, there are few data about glomerular filtration rate (eGFR) drop in patients with resistant hypertension and how diferent therapies can modify chronic kidney disease progression (CKD).

OBJECTIVE

To evaluate CKD progression in patients with resistant hypertension undergoing 2diferent therapies: treatment with spironolactone or furosemide.

METHODS

We included 30 patients (21M, 9W) with a mean age of 66.3±9.1 years, eGFR 55.8±16.5ml/min/1.73 m², SBP 162.8±8.2 and DBP 90.2±6.2mmHg: 15 patients received spironolactone and 15 furosemide and we followed up them a median of 32 months (28-41).

RESULTS

The mean annual eGFR decrease was -2.8±5.4ml/min/1.73 m². In spironolactone group was -2.1±4.8ml/min/1.73 m² and in furosemide group was -3.2±5.6ml/min/1.73 m², P<0.01. In patients received spironolactone, SBP decreased 23±9mmHg and in furosemide group decreased 16±3mmHg, P<.01. DBP decreased 10±8mmHg and 6±2mmHg, respectively (P<.01). Treatment with spironolactone reduced albuminuria from a serum albumin/creatine ratio of 210 (121-385) mg/g to 65 (45-120) mg/g at the end of follow-up, P<.01. There were no significant changes in the albumin/creatinine ratio in the furosemide group. The slower drop in kidney function was associated with lower SBP (P=.04), higher GFR (P=.01), lower albuminuria (P=.01), not diabetes mellitus (P=.01) and treatment with spironolactone (P=.02). Treatment with spironolactone (OR 2.13, IC 1.89-2.29) and lower albuminuria (OR 0.98, CI 0.97-0.99) maintain their independent predictive power in a multivariate model.

CONCLUSION

Treatment with spironolactone is more effective reducing BP and albuminuria in patients with resistant hypertension compared with furosemide and it is associated with a slower progression of CKD in the long term follow up.

Shift in the Balance between Circulating Thrombospondin-1 and Vascular Endothelial Growth Factor in Cancer Patients: Relationship to Platelet α-Granule Content and Primary Activation

Tumoral angiogenesis is regulated by the balance between factors that activate and inhibit angiogenesis. Elevated levels of activators have been associated with a poor prognosis in cancer patients, but little is known about the net balance between circulating activators and inhibitors in these patients. This study was designed to determine whether the balance between circulating concentrations of the angiogenesis inhibitor TSP-1 and the activator VEGF differs from that in healthy persons, and to shed light on the possible role of platelets in this balance. Twenty-five cancer patients and 18 healthy subjects were included. Serum and plasma concentrations of VEGF, TSP-1 and PF4 were measured by ELISA. Our results showed that in healthy subjects the balance between the TSP-1 and VEGF concentrations in serum and in serum minus plasma was twice to three times as high as in cancer patients (p<0.05). The theoretical TSP-1 content per platelet was greater in healthy subjects than in patients (94 vs. 53.6 ng/mL, p<0.05), and platelet activation (determined indirectly as the plasma concentration of PF4) was greater in cancer patients (129 vs. 48 IU/mL, p<0.01). Platelet activation correlated significantly with serum concentration of TSP-1 (r=0.470, p=0.018) and showed a tendency toward correlation with plasma concentration of TSP-1 (r=0.382, p=0.059). Our findings show that the circulating TSP-1/VEGF balance is diminished in cancer patients. Platelet activation may play an important role in this decrease and may ultimately lead to increased angiogenic activity in these patients.

Biological attenuation of arsenic and iron in a continuous flow bioreactor treating acid mine drainage (AMD)

Passive water treatments based on biological attenuation can be effective for arsenic-rich acid mine drainage (AMD). However, the key factors driving the biological processes involved in this attenuation are not well-known. Here, the efficiency of arsenic (As) removal was investigated in a bench-scale continuous flow channel bioreactor treating As-rich AMD (∼30-40 mg L^-1). In this bioreactor, As removal proceeds via the formation of biogenic precipitates consisting of iron- and arsenic-rich mineral phases encrusting a microbial biofilm. Ferrous iron (Fe(II)) oxidation and iron (Fe) and arsenic removal rates were monitored at two different water heights (4 and 25 mm) and with/without forced aeration. A maximum of 80% As removal was achieved within 500 min at the lowest water height. This operating condition promoted intense Fe(II) microbial oxidation and subsequent precipitation of As-bearing schwertmannite and amorphous ferric arsenate. Higher water height slowed down Fe(II) oxidation, Fe precipitation and As removal, in relation with limited oxygen transfer through the water column. The lower oxygen transfer at higher water height could be partly counteracted by aeration. The presence of an iridescent floating film that developed at the water surface was found to limit oxygen transfer to the water column and delayed Fe(II) oxidation, but did not affect As removal. The bacterial community structure in the biogenic precipitates in the bottom of the bioreactor differed from that of the inlet water and was influenced to some extent by water height and aeration. Although potential for microbial mediated As oxidation was revealed by the detection of aioA genes, removal of Fe and As was mainly attributable to microbial Fe oxidation activity. Increasing the proportion of dissolved As(V) in the inlet water improved As removal and favoured the formation of amorphous ferric arsenate over As-sorbed schwertmannite. This study proved the ability of this bioreactor-system to treat extreme As concentrations and may serve in the design of future in-situ bioremediation system able to treat As-rich AMD.

Cisgenesis and intragenesis: new tools for improving crops

Genetically Modified Organisms (GMO) could be the answer for many relevant problems affecting crops. However, improving crops through GMO is also often associated with safety concerns, environmental risks and health issues due to the presence of foreign DNA. These limitations have prompted the development of alternative technologies. Recently, cisgenesis and intragenesis have been developed as new tools aimed to modify crops. While cisgenesis involves genetic modification using a complete copy of natural genes with their regulatory elements that belong exclusively to sexually compatible plants, intragenesis refers to the transference of new combinations of genes and regulatory sequences belonging to that particular species. So far, application of cisgenesis and intragenesis as alternatives to conventional transgenesis are limited to a few species, mainly due to the lack of knowledge of the regulatory sequences required. The grape is one of the most cultivated crops worldwide and is the most economically relevant crop in Chile. Its genomic sequence has been completed, making available new sources of information to improve grape traits by genetic manipulation. This review is focused on the current alternatives to transgenesis in plants, including new approaches to develop marker-free crops, their application to economically relevant crops and future perspectives in the area. Also, the identification of grapevine promoters with a wide range of expression profiles is shown. The expression pattern of these genes was analyzed in different tissues and developmental stages, as well as under several stresses and stimuli, giving a broad range of expression patterns, including genes expressed exclusively during ripening, in response to sugars, senescence and biotic stress, among others. Genes with strong and constitutive expression were also identified. Functional analysis using reporter genes has been conducted in order to confirm the promoter's transcription activity, opening new possibilities for developing cisgenic/intragenic grapevines.

Water acidification trends in a reservoir of the Iberian Pyrite Belt (SW Spain)

Scarcity of waters is the main limiting factor of economic development in most arid and semi-arid regions worldwide. The construction of reservoirs may be an optimal solution to assure water availability if the drainage area shows low disturbances. This is the quandary of mining areas where economic development relies on water accessibility. Water acidification trends were investigated in the Sancho Reservoir (SW Spain) in the last 20 years. The acidity (pH3-5) and high dissolved metal concentrations (e.g., 4.4 mg/L of Al, 2.1mg/L of Mn, 1.9 mg/L of Zn) observed in the Sancho, together with the large volume stored (between 37 and 55 Mm(3)), makes this reservoir an extreme case of surface water pollution worldwide. A progressive acidification has been observed since 2003, as evidenced by decreasing pH values and increasing dissolved metal concentrations, especially noticeable after 2007. The increase in the net acidity in the reservoir originates from the higher input of metals and acidity due to the rebound effect after the mining closure in 2001. This trend was not detected in the river feeding the reservoir due to its great hydrological and hydrochemical variability, typical of the Mediterranean climate. Chemical analysis and absolute dating of sediments identified a progressive enrichment in S and metals (i.e., Fe, Zn Cu, Ni, Co and Cd) in the upper 20 cm, which reinforce the year 2002/03 as the onset of the acidification of the reservoir. The decrease of pH values from 4-5 to 3-4 occurred later than the increase in sulfate and metals due to pH-buffering by Al. The acid mine drainage (AMD) pressure has caused an increment of dissolved Fe and other metals, as well as a change in the pH buffering role, exerted now by Fe. These processes were simulated by PHREEQC, which confirms that the acidification trend will continue, causing pH values to reach 2.5 if AMD pressure persists.

Population Genetics of Plasmodium vivax in the Peruvian Amazon

Background

Characterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. Despite considerable efforts for its control, vivax malaria remains a major health problem in Peru. In this study, we have explored the population genetics of Plasmodium vivax isolates from Iquitos, the main city in the Peruvian Amazon, and 25 neighbouring peri-urban as well as rural villages along the Iquitos-Nauta Road.

Methodology/ Results

From April to December 2008, 292 P. vivax isolates were collected and successfully genotyped using 14 neutral microsatellites. Analysis of the molecular data revealed a similar proportion of monoclonal and polyclonal infections in urban areas, while in rural areas monoclonal infections were predominant (p = 0.002). Multiplicity of infection was higher in urban (MOI = 1.5–2) compared to rural areas (MOI = 1) (p = 0.003). The level of genetic diversity was similar in all areas (He = 0.66–0.76, p = 0.32) though genetic differentiation between areas was substantial (PHI_PT = 0.17, p<0.0001). Principal coordinate analysis showed a marked differentiation between parasites from urban and rural areas. Linkage disequilibrium was detected in all the areas (IAs = 0.08–0.49, for all p<0.0001). Gene flow among the areas was stablished through Bayesian analysis of migration models. Recent bottleneck events were detected in 4 areas and a recent parasite expansion in one of the isolated areas. In total, 87 unique haplotypes grouped in 2 or 3 genetic clusters described a sub-structured parasite population.

Conclusion/Significance

Our study shows a sub-structured parasite population with clonal propagation, with most of its components recently affected by bottleneck events. Iquitos city is the main source of parasite spreading for all the peripheral study areas. The routes of transmission and gene flow and the reduction of the parasite population described are important from the public health perspective as well for the formulation of future control policies.

We present the population genetics of malaria vivax parasites in a large area of the Peruvian Amazon. Our results showed that the parasite population had a predominant clonal propagation, reproducing themselves with identically or closely related parasites; therefore, the same genetic characteristics are maintained in the offspring. The clonal propagation may favour the higher levels of genetic differentiation among the parasites from isolated areas compared to areas where human migration is common. The patterns of gene flow have been established, finding Iquitos city as a reservoir of parasite genetic variability. Moreover, a recent reduction of the parasite population was observed in areas where recent control activities were performed. This research provides a picture of the nature and dynamics of the parasite population which have a significant impact in the malaria epidemiology; therefore, this knowledge is crucial for the development of efficient control policies.

Preparation and in vitro characterization of chitosan nanobubbles as theranostic agents

Theranostic delivery systems are nanostructures that combine the modality of therapy and diagnostic imaging. Polymeric micro- and nanobubbles, spherical vesicles containing a gas core, have been proposed as new theranostic carriers for MRI-guided therapy. In this study, chitosan nanobubbles were purposely tuned for the co-delivery of prednisolone phosphate and a Gd(III) complex, as therapeutic and MRI diagnostic agent, respectively. Perfluoropentane was used for filling up the internal core of the formulation. These theranostic nanobubbles showed diameters of about 500nm and a positive surface charge that allows the interaction with the negatively charged Gd-DOTP complex. Pluronic F68 was added to the nanobubble aqueous suspension as stabilizer agent. The encapsulation efficiency was good for both the active compounds, and a prolonged drug release profile was observed in vitro. The effect of ultrasound stimulation on prednisolone phosphate release was evaluated at 37°C. A marked increase on drug release kinetics with no burst effect was obtained after the exposure of the system to ultrasound. Furthermore, the relaxivity of the MRI probe changed upon incorporation in the nanobubble shell, thereby offering interesting opportunity in dual MRI-US experiments. The ultrasound characterization showed a good in vitro echogenicity of the theranostic nanobubbles. In summary, chitosan drug-loaded nanobubbles with Gd(III) complex bound to their shell might be considered a new platform for imaging and drug delivery with the potential of improving anti-cancer treatments.