Pandemic preparedness from the perspective of Occupational Health professionals

BACKGROUND

Prior to any infectious disease emergence as a public health concern, early occupational preparedness is crucial for protecting employees from novel pathogens- coronavirus disease 2019 (COVID-19) is no different.

AIMS

This study ascertains how occupational safety and health (OSH)/Human Resource (HR) professionals in the Republic of Ireland had managed to prepare their workplaces prior to the advent of COVID-19.

METHODS

As part of a larger COVID-19 workplace study, online focus groups were conducted with OSH/HR professionals. Collected data were transcribed verbatim and entered into NVivo for thematic analysis incorporating intercoder reliability testing.

RESULTS

Fifteen focus groups were conducted with OSH/HR professionals (n = 60) from various occupational settings. Three levels of organizational preparedness were identified: 'early awareness and preparation'; 'unaware and not ready' and 'aware, but not ready'. Most organizations were aware of the COVID-19 severity, but not fully prepared for the pandemic, especially stand-alone enterprises that may not have sufficient resources to cope with an unanticipated crisis. The experiences shared by OSH professionals illustrate their agility in applying risk management and control skills to unanticipated public/occupational health crises that arise.

CONCLUSIONS

General pandemic preparedness such as the availability of work-from-home policies, emergency scenario planning and prior experience in workplace outbreaks of infectious diseases were helpful for workplace-associated COVID-19 prevention. This is the first study conducted with OSH/HR professionals in Ireland regarding COVID-19 preparedness in workplaces, which provides valuable insights into research literature, as well as empirical experience for the preparation of future public health emergencies.

Benefica chirurgia. A global surgery project focusing on hernia surgery

BACKGROUND

The aim of international health cooperation projects is to alleviate the deficiencies in the area of health in low resource settings. Hernia surgery is a procedure that is well suited to these missions, due to its low morbidity, the fact that it can be performed on an outpatient basis, and the improvement in quality of life that it provides.

OBJECTIVE

To describe the results of Benefica Chirurgia (BC), a Spanish non-profit humanitarian association in hernia pathology.

METHODS

Five one-week surgical campaigns were carried out in Ecuador between 2015 and 2019, involving anesthetists, general and pediatric surgeons. Surgical and medical equipment was provided and transported by BC. ASA I/II patients underwent surgery.

RESULTS

Surgery was performed on 240 patients with hernia pathology on 27 days. Sixty-three per cent of patients were male and the mean age was 48.2 years (range: 1-83). Hernia location was inguinal in 113 patients, umbilical in 101, and other in 26. The anesthetic technique used was spinal in 185 patients (77.1%), local plus intravenous sedation in 31 (12.9%), and general in 24 (10%). The surgical technique used was hernioplasty in 191 patients, herniorrhaphy in 31, incisional hernia repair in 15 and herniotomy in three. Surgery was performed on an outpatient basis in 98.4% of cases. Morbidity was 2%. Long-term postoperative evaluation is very complex.

CONCLUSION

These campaigns make a significant contribution to health in low resource settings and provide great personal satisfaction for those involved. Standards achieved in the immediate postoperative period were similar to those obtained at the surgeons' centers in Europe. However, it is difficult to establish the rates of recurrence and chronic pain.

Unsupervised Quark/Gluon Jet Tagging With Poissonian Mixture Models

The classification of jets induced by quarks or gluons is important for New Physics searches at high-energy colliders. However, available taggers usually rely on modeling the data through Monte Carlo simulations, which could veil intractable theoretical and systematical uncertainties. To significantly reduce biases, we propose an unsupervised learning algorithm that, given a sample of jets, can learn the SoftDrop Poissonian rates for quark- and gluon-initiated jets and their fractions. We extract the Maximum Likelihood Estimates for the mixture parameters and the posterior probability over them. We then construct a quark-gluon tagger and estimate its accuracy in actual data to be in the 0.65-0.7 range, below supervised algorithms but nevertheless competitive. We also show how relevant unsupervised metrics perform well, allowing for an unsupervised hyperparameter selection. Further, we find that this result is not affected by an angular smearing introduced to simulate detector effects for central jets. The presented unsupervised learning algorithm is simple; its result is interpretable and depends on very few assumptions.

Central vein sign: A diagnostic biomarker in multiple sclerosis (CAVS-MS) study protocol for a prospective multicenter trial

The specificity and implementation of current MRI-based diagnostic criteria for multiple sclerosis (MS) are imperfect. Approximately 1 in 5 of individuals diagnosed with MS are eventually determined not to have the disease, with overreliance on MRI findings a major cause of MS misdiagnosis. The central vein sign (CVS), a proposed MRI biomarker for MS lesions, has been extensively studied in numerous cross sectional studies and may increase diagnostic specificity for MS. CVS has desirable analytical, measurement, and scalability properties. "Central Vein Sign: A Diagnostic Biomarker in Multiple Sclerosis (CAVS-MS)" is an NIH-supported, 2-year, prospective, international, multicenter study conducted by the North American Imaging in MS Cooperative (NAIMS) to evaluate CVS as a diagnostic biomarker for immediate translation into clinical care. Study objectives include determining the concordance of CVS and McDonald Criteria to diagnose MS, the sensitivity of CVS to detect MS in those with typical presentations, and the specificity of CVS among those with atypical presentations. The study will recruit a total of 400 participants (200 with typical and 200 with atypical presentations) across 11 sites. T2*-weighted, high-isotropic-resolution, segmented echo-planar MRI will be acquired at baseline and 24 months on 3-tesla scanners, and FLAIR* images (combination of FLAIR and T2*) will be generated for evaluating CVS. Data will be processed on a cloud-based platform that contains clinical and CVS rating modules. Imaging quality control will be conducted by automated methods and neuroradiologist review. CVS will be determined by Select6* and Select3* lesion methods following published criteria at each site and by central readers, including neurologists and neuroradiologists. Automated CVS detection and algorithms for incorporation of CVS into McDonald Criteria will be tested. Diagnosis will be adjudicated by three neurologists who served on the 2017 International Panel on the Diagnosis of MS. The CAVS-MS study aims to definitively establish CVS as a diagnostic biomarker that can be applied broadly to individuals presenting for evaluation of the diagnosis of MS.

Male breast cancer diagnosis stages, treatment and survival in Uruguay: a retrospective analysis of a case series

Male breast cancer (MBC) is a rare condition which, while sharing some similarities with breast cancer in women, has a unique disease profile of its own. Aim: To understand the characteristics of MBC and its management in Uruguay. Patients & methods: Retrospective observational study that included patients diagnosed with MBC. Results: 22 cases of MBC were found. The median age at diagnosis was 62.5 years. Symptoms included self-detected lump in 17 patients (77.3%) and nipple retraction in seven (22.7%). Ductal carcinomas of histological grade 2–3 were found in 20 patients (90.9%) and stage I–II disease was most commonly encountered (15 patients, 68.1%). Neoadjuvant chemotherapy, adjuvant chemotherapy, adjuvant radiotherapy and tamoxifen were offered to 16 (73%), 12 (54.5%), 17 (65.4%) and 20 (90.9%) patients, respectively. Conclusion: MBC behaves and is treated in many aspects like postmenopausal breast cancer. Further multi-institutional, prospective studies are needed for better understanding and management of male breast cancers.

Identification and diagnosis of Secondary Progressive Multiple Sclerosis during the clinical encounter: Results from a physician survey

BACKGROUND

It is difficult to characterize the transition from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive MS (SPMS), due to symptomatic variability across patients. Diagnosis of SPMS is prolonged and often established retrospectively, as it is based on patient clinical history and symptoms. This cross-sectional study aimed to identify MS neurologist reported clinical indicators deemed important in diagnosing SPMS in clinical practice.

METHODS

A web-based quantitative survey was conducted among MS-treating neurologists across the United States in January 2019. The questionnaire comprised of 17 questions evaluating primary clinical indicators used by neurologists in assessing patient progression to SPMS. Treatment approach and factors influencing treatment decision-making following SPMS diagnosis were also analyzed in the survey.

RESULTS

Overall, 300 neurologists completed the survey; most of the respondents were general MS-treating neurologists (63%) and from private care setting (58%). The overall respondents as well as MS-focused neurologists ranked patient history (45% and 42%, respectively) and patients' neurological exam (39% and 44%, respectively) as -primary clinical indicators of SPMS diagnosis. 57% of neurologists always or mostly switched disease modifying therapies after progression to SPMS, and mostly considered 3-6 months' assessment interval to diagnose SPMS.

CONCLUSION

The survey indicated that neurologists are able to recognize signs of SPMS within six months of symptomatic assessment. The diagnosis is primarily based on patient history among MS-treating neurologists. Therefore, continued education to neurologists may facilitate early diagnosis and timely introduction of effective treatment to manage the progression of SPMS.

Trunk and pelvis movement compensation in people with multiple sclerosis: Relationships to muscle function and gait performance outcomes

BACKGROUND

Problems with gait are common in people with multiple sclerosis (MS), but little is known about pelvis and trunk kinematics, especially in the frontal plane.

RESEARCH QUESTION

Are pelvis and trunk kinematics in people with MS related to muscle function, spatiotemporal parameters, and gait performance?

METHODS

In this cross-sectional study, 20 people with MS (Expanded Disability Status Scale 1.5-5.5) and 10 people with comparable age and sex (CTL) underwent threedimensional gait analysis, muscle function assessments (hip and trunk strength and endurance), and gait performance measures (Timed 25-Foot Walk - T25FW, 2-Minute Walk Test - 2MWT). Frontal and sagittal plane pelvis and trunk excursion during the stance period of walking were compared between groups; and in the MS group, associations were determined between kinematic variables, muscle function, spatiotemporal parameters, and gait performance.

RESULTS

Compared to the CTL group, the MS group had significantly greater sagittal plane trunk and pelvis excursion for both the stronger (p = 0.031) and weaker (p = 0.042) sides; less frontal plane trunk and pelvis excursion for both the stronger (p = 0.008) and weaker (p = 0.024) sides; and more sagittal plane trunk excursion for the stronger side (p = 0.047) during stance phase. There were low-to-moderate correlations in the MS group for sagittal plane pelvis excursion with muscle function (p = 0.019 to 0.030), spatiotemporal parameters (p < 0.001 to 0.005), and gait performance (p = < 0.001 to 0.001). Using linear regression, frontal and sagittal plane pelvis excursion were significant predictors of both T25FW and 2MWT, explaining 34 % and 46 % of the variance of each gait performance measure, respectively.

SIGNIFICANCE

Rehabilitation interventions may consider addressing pelvis movement compensations in order to improve spatiotemporal parameters and gait performance in people with MS.

Obesity-Related Genetic Determinants of Heart Failure Prognosis

PURPOSE

Recent advances in genomics offer a smart option for predicting future risk of disease and prognosis. The objective of this study was to examine the prognostic value in heart failure (HF) patients, of a series of single nucleotide polymorphisms (SNPs).

METHODS

A selection of 192 SNPs found to be related with obesity, body mass index, circulating lipids or cardiovascular diseases were genotyped in 191 patients with HF. Anthropometrical and clinical variables were collected for each patient, and death and readmission by HF were registered as the primary endpoint.

RESULTS

A total of 53 events were registered during a follow-up period of 438 (263-1077) days (median (IQR)). Eight SNPs strongly related to obesity and HF prognosis were selected as possible prognostic variables. From these, rs10189761 and rs737337 variants were independently associated with HF prognosis (HR 2.295 (1.287-4.089, 95% CI); p = 0.005), whereas rs10423928, rs1800437, rs737337 and rs9351814 were related with bad prognosis only in obese patients (HR 2.142 (1.438-3.192, 95% CI); p = 0.00018). Combined scores of the genomic variants were highly predictive of poor prognosis.

CONCLUSIONS

SNPs rs10189761 and rs737337 were identified, for the first time, as independent predictors of major clinical outcomes in patients with HF. The data suggests an additive predictive value of these SNPs for a HF prognosis. In particular for obese patients, SNPs rs10423928, rs1800437, rs737337 and rs9351814 were related with a bad prognosis. Combined scores weighting the risk of each genomic variant could effect interesting new tools to stratify the prognostic risk of HF patients.

Influence of Acculturation on Emotional Learning and Memory in Spanish and English Speakers

Objective

The Emotional Verbal Learning Test-Spanish (EVLT-S) is a novel list learning test similar in structure to traditional verbal memory tests but contains words from 4 discrete emotional categories. Influence of acculturation on emotional learning was examined on EVLT-S learning trials 1 to 5.

Participants and Method

Participants included 50 bilingual healthy individuals in the Spanish-dominant group (Age M = 20.3years; 72% female) and 27 in the English-dominant group (Age M = 23.4years, 51.9% female). They were administered a battery of tests including the EVLT, a non-emotional verbal list learning test (LLT), Vocabulary (VC), Digit Span (DS), and The Short Acculturation Scale for Hispanics (SASH) in their dominant language. To examine learning curves a mixed model ANOVA was conducted with test (EVLT-S/EVLT, LLT-S/LLT) and trial as within-subjects variables and group (Spanish, English) as a between-subjects variable.

Results

There were significant main effects (p &lt; .005) for test, trial, and group. The Spanish-dominant group had the lowest overall performance on the EVLT-S (main effect for group). Post hoc comparisons of the Spanish-dominant group’s LLT-S and EVLT-S performance indicated significant differences at each trail (p &lt; .01), with the EVLT-S scores being lower than the LLT-S scores. The ANOVA was repeated with VC, DS, and SASH included as covariates. When controlling for these variables, the main effect for group was no longer significant. A significant trial by acculturation interaction effect emerged (p&lt;.05), with the English-dominant group generally performing better than the Spanish-dominant group.

Conclusions

Results suggest that Spanish and English language group differences were largely accounted for by word knowledge (VC), working memory (DS), and acculturation differences (SASH) between the groups. The role of these variables is discussed further in the context of acculturation.

Breast cancer PAM50 signature: correlation and concordance between RNA-Seq and digital multiplexed gene expression technologies in a triple negative breast cancer series

Background

Full RNA-Seq is a fundamental research tool for whole transcriptome analysis. However, it is too costly and time consuming to be used in routine clinical practice. We evaluated the transcript quantification agreement between RNA-Seq and a digital multiplexed gene expression platform, and the subtype call after running the PAM50 assay in a series of breast cancer patients classified as triple negative by IHC/FISH. The goal of this study is to analyze the concordance between both expression platforms overall, and for calling PAM50 triple negative breast cancer intrinsic subtypes in particular.

Results

The analyses were performed in paraffin-embedded tissues from 96 patients recruited in a multicenter, prospective, non-randomized neoadjuvant triple negative breast cancer trial (NCT01560663). Pre-treatment core biopsies were obtained following clinical practice guidelines and conserved as FFPE for further RNA extraction. PAM50 was performed on both digital multiplexed gene expression and RNA-Seq platforms. Subtype assignment was based on the nearest centroid classification following this procedure for both platforms and it was concordant on 96% of the cases (N = 96). In four cases, digital multiplexed gene expression analysis and RNA-Seq were discordant. The Spearman correlation to each of the centroids and the risk of recurrence were above 0.89 in both platforms while the agreement on Proliferation Score reached up to 0.97. In addition, 82% of the individual PAM50 genes showed a correlation coefficient > 0.80.

Conclusions

In our analysis, the subtype calling in most of the samples was concordant in both platforms and the potential discordances had reduced clinical implications in terms of prognosis. If speed and cost are the main driving forces then the preferred technique is the digital multiplexed platform, while if whole genome patterns and subtype are the driving forces, then RNA-Seq is the preferred method.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5849-0) contains supplementary material, which is available to authorized users.

PAS Kinase deficiency alters the glucokinase function and hepatic metabolism

The liver controls metabolic homeostasis in response to fasting and refeeding periods. Glucokinase (GCK) adjusts hepatic glucose phosphorylation to blood glucose levels, acting as a glucose sensor. Our objective was to determine whether PAS kinase (PASK), a nutrient sensor, could be affecting the expression or activity of liver GCK and the response to fasting and refeeding states of key hepatic metabolic pathways. PASK-deficient mice have impaired insulin signaling (AKT overactivation). Furthermore, PASK deficiency modified the expression of several transcription factors involved in the adjustment to fasting and refeeding. Foxo1 decreased under fasting conditions, while Ppara and Pparg were overexpressed in PASK-deficient mice. However, PEPCK protein levels were similar or higher, while the expression of Cpt1a decreased in PASK-deficient mice. By contrast, Lxra and Chrebp were overexpressed after refeeding, while the expression of Acc and Fas decreased in PASK-deficient mice. Likewise, with a decreased expression of Gck and increased nuclear location of the complex GCK-GCKR, GCK activity decreased in PASK-deficient mice. Therefore, PASK regulated some of the genes and proteins responsible for glucose sensing, such as glucokinase, and for insulin signalling, affecting glucose and lipid metabolism and consequently certain critical hepatic functions.

In Vitro and In Vivo Antiaggregant Effects of Magnesium Halogenates

The in vitro antiplatelet aggregating activity of magnesium and magnesium associated with soluble citroflavomJids (hesperidin and eriodictin, 1:1) is well-established.

The degree of inhibition of in vitro platelet aggregation activity produced by different concentrations of magnesium halogenates was determined. ADP (4 μM) was used to induce aggregation following Cardinal and Flowers’ (1) technique.

Antithtombotic activity was studied in vivo. The differencein duration. of ADP-induced respiratory dysfunction was compared between animals fed 25 mg/kg magnesium halogenates for 10 days before testing and controls.

An increase in circulating platelets was observed in rats treated with magnesium halogenates.

Cognitive predictors of illness course at 12 months after first-episode of depression

Major Depressive Disorder (MDD) entails cognitive dysfunction in many cognitive domains, but it is still uncertain whether such deficits are present in the early stages. The purpose of the study is to determine the cognitive performance in first episode depression (FED) exploring the presence of different cognitive profiles, and the role of cognition in FED at baseline and long-term. Ninety subjects (18-50 years) were included, 50 patients with a FED and 40 healthy controls. Participants were assessed with a neuropsychological battery, covering language, attention, verbal memory, processing speed and executive domains. Neuropsychological group comparisons were performed with MANOVAs. A hierarchical cluster analysis was run to identify clusters of patients with similar neuropsychological performance. Two generalized linear models were built to predict baseline HDRS-17 and changes at 12 months. Patients performed significantly worse than healthy controls in language, attention/working memory, verbal memory, processing speed and executive functioning, with moderate to large effect sizes (0.5 - 1). Two clusters were found: cognitively preserved patients (n=37) and cognitively impaired patients (n=13). Large effect sizes of cognitive impairment in FED were observed between the two cognitive clusters (preserved and impaired). Depressive symptoms at baseline were predicted by verbal memory (p=0.003), while 12-month changes were predicted by executive function (p=0.041) and language (p=0.037). Cognitive performance predicted depressive symptoms at baseline and at follow-up, pointing to the usefulness of cognitive assessment even at the commencement of the illness.

A novel method for quantitative myocardial contrast echocardiography in mice

The small size of the mouse heart frequently imparts technical challenges when applying conventional in vivo imaging methods for assessing heart function. Here, we describe the use of high-frequency ultrasound imaging in conjunction with a size-tuned blood pool contrast agent for quantitatively assessing myocardial perfusion in living mice. A perflurocarbon microbubble formulation exhibiting a narrow size distribution was developed, and echogenicity was assessed at 18 MHz in vitro. Adult mice were subjected to permanent ligation of the left anterior descending artery. Ultrasound imaging was performed on day 7, and a cohort of intact mice was used as a control. Parasternal long-axis cine clips were acquired at 18 MHz before and after contrast administration. Reduced ejection fraction and increased end-systolic volume were observed in infarcted compared with control mice. In control animals, washin of the contrast agent was visible in all myocardial segments. Reduced contrast enhancement was observed in apical-posterolateral regions of all infarcted mice. A novel method for reslicing of the imaging data through the time domain provided a two-dimensional presentation of regional contrast agent washin, enabling convenient identification of locations exhibiting altered perfusion. Myocardial segments exhibiting diminished contractility were observed to have correspondingly low relative myocardial perfusion. The contrast agent formulation and methods demonstrated here provide the basis for simplifying routine in vivo estimation of infarct size in mice and may be particularly useful in longitudinal evaluation of revascularization interventions and assessment of peri-infarct ischemia. NEW & NOTEWORTHY Murine myocardial contrast echocardiography frequently suffers from poor sensitivity to contrast. Here, we formulated a novel size-tuned microbubble contrast agent and validated it for use with ultra-high-frequency ultrasound. A novel data method for evaluating myocardial perfusion based on reslicing the imaging data through the time domain is presented.

Metal-free, direct conversion of α-amino acids into α-keto γ-amino esters for the synthesis of α,γ-peptides

An efficient, metal-free synthesis of unusual α-keto γ-amino esters from α-amino acids is achieved by a radical scission–oxidation–addition of silyloxy acrylates procedure, where no purification of the reaction intermediates is needed. The process allows the synthesis of α,γ-peptides.

Phase II study of first-line biweekly docetaxel and cisplatin combination chemotherapy in advanced gastric cancer

PURPOSE

Previous studies have shown that docetaxel and cisplatin, as single agents, are effective and relatively well tolerated in patients with advanced gastric cancer. The aim of this study was to assess efficacy and toxicity of a biweekly regimen of docetaxel plus cisplatin in patients with advanced gastric cancer.

PATIENTS/METHODS

Fifty-five patients with histologically proven advanced gastric cancer with at least 1 measurable lesion and ECOG PS ≤ 2 were enrolled. Patients received docetaxel 50 mg/m(2) and cisplatin 50 mg/m(2) every 2 weeks until progression disease, unbearable toxicity or a maximum of 12 cycles.

RESULTS

In total, 426 cycles were administered (median 8.5 cycles) to 52 evaluable patients. One patient (1.9 %) showed a complete response, while 21 (40.4 %) had partial responses. The objective response rate was 42.3 % (95 % CI 28.9-55.7), the median time to progression was 5.5 months (95 % CI 4.0-7.0), and the median overall survival was 8.9 months (95 % CI 6.0-11.9). The most common grade 3-4 toxicities per cycle were haematological [neutropenia (5.9 %)].

CONCLUSIONS

Biweekly administration of docetaxel and cisplatin in advanced gastric cancer has a manageable toxicity profile and shows a promising antitumour activity as a first-line therapy.

Synthesis of the putative structure of 15-oxopuupehenoic acid

Synthesis of the putative structure of the marine natural 15-oxopuupehenoic acid has been achieved starting from commercial (-)-sclareol. Key steps of the synthetic sequence are the Robinson annulation of a β-ketoester and methyl vinyl ketone and an unprecedented cyclization of the resulting α,β-enone, which is mediated by tin(IV) chloride in the presence of N-phenylselenophthalimide. The physical properties of the synthetic compound are somewhat different from those reported for the natural product.

Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

AIM

The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset.

LOCATION

Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1.

METHODS

Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons.

RESULTS

The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%.

MAIN CONCLUSIONS

Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities, because neither wood density nor species assemblages can be reliably mapped from space.

Microstructural white-matter abnormalities associated with treatment resistance, severity and duration of illness in major depression

BACKGROUND

Although white-matter abnormalities have been reported in middle-aged patients with major depressive disorder (MDD), few data are available on treatment-resistant MDD and the influence of relevant variables related to clinical burden of illness is far from being well established.

METHOD

The present study examined white-matter microstructure in a sample of 52 patients with MDD in different stages (treatment-resistant/chronic MDD, n = 18; remitted-recurrent MDD, n = 15; first-episode MDD, n = 19) and 17 healthy controls, using diffusion tensor imaging with a tract-based spatial statistics approach. Groups were comparable in age and gender distribution, and results were corrected for familywise error (FWE) rate.

RESULTS

Widespread significant reductions of fractional anisotropy (FA) - including the cingulum, corpus callosum, superior and inferior longitudinal fascicule - were evident in treatment-resistant/chronic MDD compared with first-episode MDD and controls (p < 0.05, FWE-corrected). Decreased FA was observed within the ventromedial prefrontal region in treatment-resistant/chronic MDD even when compared with the remitted-recurrent MDD group (p < 0.05, FWE-corrected). Longer duration of illness (β = -0.49, p = 0.04) and higher depression severity (at a trend level: β = -0.26, p = 0.06) predicted lower FA in linear multiple regression analysis at the whole-brain level. The number of previous episodes and severity of symptoms were significant predictors when focused on the ventromedial prefrontal area (β = -0.28, p = 0.04; and β = -0.29, p = 0.03, respectively). Medication effects were controlled for in the analyses and results remained unaltered.

CONCLUSIONS

Our findings support the notion that disruptions of white-matter microstructure, particularly in fronto-limbic networks, are associated with resistance to treatment and higher current and past burden of depression.

Fast demographic traits promote high diversification rates of Amazonian trees

The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits – short turnover times – are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rates are either constant or decline over time, and occurs in a wide range of Neotropical tree lineages. This finding reveals the crucial role of intrinsic, ecological variation among clades for understanding the origin of the remarkable diversity of Amazonian trees and forests.

A short synthetic route towards merosesquiterpenes with a benzoxanthene skeleton

A short synthetic sequence for the preparation of merosesquiterpenes with a benzoxanthene skeleton starting from (−)-sclareol is reported. The D ring of the target compound is obtained through a Diels–Alder cycloaddition.

Preclinical and clinical characterization of the selective 5-HT(1A) receptor antagonist DU-125530 for antidepressant treatment

BACKGROUND AND PURPOSE

The antidepressant efficacy of selective 5-HT reuptake inhibitors (SSRI) and other 5-HT-enhancing drugs is compromised by a negative feedback mechanism involving 5-HT(1A) autoreceptor activation by the excess 5-HT produced by these drugs in the somatodendritic region of 5-HT neurones. 5-HT(1A) receptor antagonists augment antidepressant-like effects in rodents by preventing this negative feedback, and the mixed β-adrenoceptor/5-HT(1A) receptor antagonist pindolol improves clinical antidepressant effects by preferentially interacting with 5-HT(1A) autoreceptors. However, it is unclear whether 5-HT(1A) receptor antagonists not discriminating between pre- and post-synaptic 5-HT(1A) receptors would be clinically effective.

EXPERIMENTAL APPROACH

We characterized the pharmacological properties of the 5-HT(1A) receptor antagonist DU-125530 using receptor autoradiography, intracerebral microdialysis and electrophysiological recordings. Its capacity to accelerate/enhance the clinical effects of fluoxetine was assessed in a double-blind, randomized, 6 week placebo-controlled trial in 50 patients with major depression (clinicaltrials.gov identifier NCT01119430).

KEY RESULTS

DU-125530 showed equal (low nM) potency to displace agonist and antagonist binding to pre- and post-synaptic 5-HT(1A) receptors in rat and human brain. It antagonized suppression of 5-hydroxytryptaminergic activity evoked by 8-OH-DPAT and SSRIs in vivo. DU-125530 augmented SSRI-induced increases in extracellular 5-HT as effectively as in mice lacking 5-HT(1A) receptors, indicating a silent, maximal occupancy of pre-synaptic 5-HT(1A) receptors at the dose used. However, DU-125530 addition to fluoxetine did not accelerate nor augment its antidepressant effects.

CONCLUSIONS AND IMPLICATIONS

DU-125530 is an excellent pre- and post-synaptic 5-HT(1A) receptor antagonist. However, blockade of post-synaptic 5- HT(1A) receptors by DU-125530 cancels benefits obtained by enhancing pre-synaptic 5-hydroxytryptaminergic function.