Variable Selection for Covariate Dependent Dirichlet Process Mixtures of Regressions

Dirichlet Process Mixture (DPM) models have been increasingly employed to specify random partition models that take into account possible patterns within the covariates. Furthermore, in response to large numbers of covariates, methods for selecting the most important covariates have been proposed. Commonly, the covariates are chosen either for their importance in determining the clustering of the observations or for their effect on the level of a response variable (in case a regression model is specified). Typically both strategies involve the specification of latent indicators that regulate the inclusion of the covariates in the model. Common examples involve the use of spike and slab prior distributions. In this work we review the most relevant DPM models that include the covariate information in the induced partition of the observations and we focus extensively on available variable selection techniques for these models. We highlight the main features of each model and demonstrate them in simulations

A bayesian nonparametric model for white blood cells in patients with lower urinary tract symptoms

Lower Urinary Tract Symptoms (LUTS) affect a significant proportion of the population and often lead to a reduced quality of life. LUTS overlap across a wide variety of diseases, which makes the diagnostic process extremely complicated. In this work we focus on the relation between LUTS and Urinary Tract Infection (UTI). The latter is detected through the number of White Blood Cells (WBC) in a sample of urine: WBC≥ 1 indicates UTI and high levels may indicate complications. The objective of this work is to provide the clinicians with a tool for supporting the diagnostic process, deepening the available knowledge about LUTS and UTI. We analyze data recording both LUTS profile and WBC count for each patient. We propose to model the WBC using a random partition model in which we specify a prior distribution over the partition of the patients which includes the clustering information contained in the LUTS profile. Then, within each cluster, the WBC counts are assumed to be generated by a zero-inflated Poisson distribution. The results of the predictive distribution allows to identify the symptoms configuration most associated with the presence of UTI as well as with severe infections

Lower urinary tract symptoms that predict microscopic pyuria

INTRODUCTION AND HYPOTHESIS: Urinary dipsticks and culture analyses of a mid-stream urine specimen (MSU) at 10(5) cfu ml(-1) of a known urinary pathogen are considered the gold standard investigations for diagnosing urinary tract infection (UTI). However, the reliability of these tests has been much criticised and they may mislead. It is now widely accepted that pyuria (≥1 WBC μl(-1)) detected by microscopy of a fresh unspun, unstained specimen of urine is the best biological indicator of UTI available. We aimed to scrutinise the greater potential of symptoms analysis in detecting pyuria and UTI. METHODS: Lower urinary tract symptom (LUTS) descriptions were collected from patients with chronic lower urinary tract symptoms referred to a tertiary referral unit. The symptoms informed a 39-question inventory, grouped into storage, voiding, stress incontinence and pain symptoms. All questions sought a binary yes or no response. A bespoke software package was developed to collect the data. The study was powered to a sample of at least 1,990 patients, with sufficient power to analyse 39 symptoms in a linear model with an effect size of Cohen's f(2) = 0.02, type 1 error probability = 0.05; and power (1-β); 95% where β is the probability of type 2 error). The inventory was administered to 2,050 female patients between August 2004 and November 2011. The data were collated and the following properties assessed: internal consistency, test-retest reliability, inter-observer reliability, internal responsiveness, external responsiveness, construct validity analysis and a comparison with the International Consultation on Incontinence Modular Questionnaire for female lower urinary tract symptoms (ICIQ-FLUTS). The dependent variable used as a surrogate marker of UTI was microscopic pyuria. An MSU sample was sent for routine culture. RESULTS: The symptoms proved reliable predictors of microscopic pyuria. In particular, voiding symptoms correlated well with microscopic pyuria (χ(2) = 88, df = 1, p < 0.001). The symptom inventory has significant psychometric characteristics as below: test-retest reliability: Cronbach's alpha was 0.981; inter-observer reliability, Cronbach's alpha was 0.995, internal responsiveness F = 221, p < 0.001, external responsiveness F = 359, df = 5, p < 0.001. The correlation coefficients for the domains of the ICIQ-FLUTS were around R = 0.5, p < 0.001. CONCLUSION: This symptoms score performed well on the standard, psychometric validation. The score changed in response to treatment and in a direction appropriate to the changes in microscopic pyuria. It correlated with measures of quality of life. It would seem to make a good candidate for monitoring treatment progress in ordinary clinical practice

Recalcitrant chronic bladder pain and recurrent cystitis but negative urinalysis - what should we do?

Purpose: Lower urinary tract symptoms (LUTS) may be associated with chronic urinary tract infection (UTI) undetected by routine diagnostic tests. Antimicrobial therapy might confer benefit for these patients. Materials and Methods: Over ten years, we treated patients with chronic LUTS. Pyuria was adopted as the principal biomarker of infection. Urinary leucocyte counts were recorded from microscopy of fresh midstream urine (MSU) samples. Antibiotics were prescribed and the prescription adjusted to achieve a measurable clinical response and a reduction in pyuria. Results: We treated 624 women (mean age=53.4 years; sd=18) with chronic LUTS and pyuria. The mean duration of symptoms prior to presentation was 6.5 years. Only 16% of MSU cultures submitted were positive (≥105 cfu ml-1). Mean treatment length was 383 days (SD=347; 95% CI=337-428). Treatment was associated with a reduction in total LUTS (F=98; p=.0001), 24-hour frequency (F=75; p=.0001), urinary 3 urgency (F=90; p=.0001), lower urinary tract pain (F=108; p=.0001), voiding symptoms (F=10; p=.002) and pyuria (F=15.4; p=.0001). Full-dose first-generation urinary antibiotic (such as cefalexin, nitrofurantoin, or trimethoprim) was combined with Methenamine Hippurate. We recorded 475 adverse events (AEs) during 273,762 treatment days. There was only one serious adverse event (SAE). We observed no increase in the proportion of resistant bacterial isolates. Conclusion: This large case series demonstrates that patients with chronic LUTS and pyuria experience symptom regression and a reduction in urinary tract inflammation associated with antimicrobial therapy. Disease regression was achieved with a low frequency of AEs. These results provide preliminary data to inform a future RCT

ESTUDO COMPARATIVO DO POTENCIAL INFLAMATÓRIO DE EXTRATOS VEGETAIS INSETICIDAS

Pediculose é uma infestação causada pelo parasita Pediculus humanus capitis De Geer, conhecido popularmente como piolho. A doença é considerada um problema sério de saúde pública. Embora existam diversos tratamentos populares para a infestação, poucos estudos científicos comprovam a eficácia dos tratamentos. A utilização de espécies vegetais com atividade inseticida antipediculose, além de acessível à população de baixa renda, também se constitui em tratamento alternativo eficaz para o controle da doença. Os extratos vegetais obtidos de Melia azedarach L., Ruta graveolens L. e Sambucus australis Cham. et Schlecht  apresentam atividade antipediculose, no entanto é importante investigar o potencial inflamatório destes extratos. O presente trabalho analisou o poder de indução inflamatória de extratos hidroalcoólicos das espécies vegetais M. azedarach, R. graveolens e Sambucus australis, empregando ratos da linhagem Wistar. Neste estudo não foi possível constatar a existência de inflamação significativa produzida pelos três extratos vegetais nos níveis dos tempos investigados

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 3

In this contribution, new data concerning bryophytes, fungi and lichens and of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera Dicranodontium, Fontinalis, Lophocolea and Riccia, the fungal genus Diplolaeviopsis, the lichen genera Agonimia, Cladonia, Protoparmelia, Rhizocarpon, and Scytinium

Cardiac Structural and Functional Consequences of Amyloid Deposition by Cardiac Magnetic Resonance and Echocardiography and Their Prognostic Roles

OBJECTIVES: This cross-sectional study aimed to describe the functional and structural cardiac abnormalities that occur across a spectrum of cardiac amyloidosis burden and to identify the strongest cardiac functional and structural prognostic predictors in amyloidosis using cardiac magnetic resonance (CMR) and echocardiography. BACKGROUND: Cardiac involvement in light chain and transthyretin amyloidosis is the main driver of prognosis and influences treatment strategies. Numerous measures of cardiac structure and function are assessed by multiple imaging modalities in amyloidosis. METHODS: Three hundred twenty-two subjects (311 systemic amyloidosis and 11 transthyretin gene mutation carriers) underwent comprehensive CMR and transthoracic echocardiography. The probabilities of 11 commonly measured structural and functional cardiac parameters being abnormal with increasing cardiac amyloidosis burden were evaluated. Cardiac amyloidosis burden was quantified using CMR-derived extracellular volume. The prognostic capacities of these parameters to predict death in amyloidosis were assessed using Cox proportional hazards models. RESULTS: Left ventricular mass and mitral annular plane systolic excursion by CMR along with strain and E/e' by echocardiography have high probabilities of being abnormal at low cardiac amyloid burden. Reductions in biventricular ejection fractions and elevations in biatrial areas occur at high burdens of infiltration. The probabilities of indexed stroke volume, myocardial contraction fraction, and tricuspid annular plane systolic excursion (TAPSE) being abnormal occur more gradually with increasing extracellular volume. Ninety patients (28%) died during a median follow-up of 22 months (interquartile range: 10 to 38 months). Univariable analysis showed that all imaging markers studied significantly predicted outcome. Multivariable analysis showed that TAPSE (hazard ratio: 1.46; 95% confidence interval: 1.16 to 1.85; p < 0.01) and indexed stroke volume (hazard ratio: 1.24; 95% confidence interval: 1.04 to 1.48; p < 0.05) by CMR were the only independent predictors of mortality. CONCLUSIONS: Specific functional and structural abnormalities characterize different burdens of cardiac amyloid deposition. In a multimodality imaging assessment of a large cohort of amyloidosis patients, CMR-derived TAPSE and indexed stroke volume are the strongest prognostic cardiac functional markers

Association of beta-blockers and first-registered heart rhythm in out-of-hospital cardiac arrest: real-world data from population-based cohorts across two European countries

AIMS: Conflicting results have been reported regarding the effect of beta-blockers on first-registered heart rhythm in out-of-hospital cardiac arrest (OHCA). We aimed to establish whether the use of beta-blockers influences first-registered rhythm in OHCA. METHODS AND RESULTS: We included patients with OHCA of presumed cardiac cause from two large independent OHCA-registries from Denmark and the Netherlands. Beta-blocker use was defined as exposure to either non-selective beta-blockers, β1-selective beta-blockers, or α-β-dual-receptor blockers within 90 days prior to OHCA. We calculated odds ratios (ORs) for the association of beta-blockers with first-registered heart rhythm using multivariable logistic regression. We identified 23 834 OHCA-patients in Denmark and 1584 in the Netherlands: 7022 (29.5%) and 519 (32.8%) were treated with beta-blockers, respectively. Use of non-selective beta-blockers, but not β1-selective blockers, was more often associated with non-shockable rhythm than no use of beta-blockers [Denmark: OR 1.93, 95% confidence interval (CI) 1.48-2.52; the Netherlands: OR 2.52, 95% CI 1.15-5.49]. Non-selective beta-blocker use was associated with higher proportion of pulseless electrical activity (PEA) than of shockable rhythm (OR 2.38, 95% CI 1.01-5.65); the association with asystole was of similar magnitude, although not statistically significant compared with shockable rhythm (OR 2.34, 95% CI 0.89-6.18; data on PEA and asystole were only available in the Netherlands). Use of α-β-dual-receptor blockers was significantly associated with non-shockable rhythm in Denmark (OR 1.21; 95% CI 1.03-1.42) and not significantly in the Netherlands (OR 1.37; 95% CI 0.61-3.07). CONCLUSION: Non-selective beta-blockers, but not β1-selective beta-blockers, are associated with non-shockable rhythm in OHCA

First overview on the 4th Annex I Habitats Report in Italy: methods, criticality, results and future prospects

Like all the other EU/28 countries, in 2019 Italy developed the 4th Italian Report ex-Art. 17 on the conservation status of the Habitats of Annex I to the 92/43/EEC Directive. Institutional referent of the process, on behalf of the Ministry for Environment, Land and Sea Protection (MATTM), was the Italian Institute for Environmental Protection and Research (ISPRA) with the scientific support of the Italian Botanical Society (SBI). A huge working group composed of thematic and territorial experts was formed with the task to collect, analyse, validate the data resulting from Annex I Habitat monitoring in Italy for the period 2013-2018, whose collection is in charge to the regional administrations. Data on 124 types of terrestrial and inland water Habitats present in Italy have been processed in order to assess their overall conservation status in the Biogeographic Regions of occurrence. The carried out activity led to the compilation of 278 assessment sheets. The work included a critical analysis of the data and a broad scientific confrontation aimed at finding methodologically robust solutions to fill the gaps. The work was structured so as to guarantee the traceability of the information and to allow the collection of "gray" literature and scientific articles, phytosociological surveys and unpublished material of the specialists, composing a substantial pool of data useful for starting a long-term process to support the next reporting cycles. Cartographic outcomes, associated databases and additional data used for the assessments will be available online on the ISPRA Portal as soon as the validation process by the European Commission will be completed. A freely accessible online archive of phytosociological surveys representative of the various Annex I Habitats in Italy is being set up within the national "VegItaly" database, managed by the Italian Society of Vegetation Science, by way of a dedicated archive named "HAB_IT". Such a long-term vision, oriented to the storage and enhancement of knowledge, represents an important innovative aspect and a significant progress towards the construction of an effective monitoring system for the conservation of Annex I Habitats in Italy