RFPID: development and 3D-printing of a female physical phantom for whole-body counter

Whole-body counters (WBC) are used in internal dosimetry forin vivomonitoring in radiation protection. The calibration processes of a WBC set-up include the measurement of a physical phantom filled with a certificate radioactive source that usually is referred to a standard set of individuals determined by the International Commission on Radiological Protection (ICRP). The aim of this study was to develop an anthropomorphic and anthropometric female physical phantom for the calibration of the WBC systems. The reference female computational phantom of the ICRP, now called RFPID (Reference Female Phantom for Internal Dosimetry) was printed using PLA filament and with an empty interior. The goal is to use the RFPID to reduce the uncertainties associated within vivomonitoring system. The images which generated the phantom were manipulated using ImageJ®, Amide®, GIMP®and the 3D Slicer®software. RFPID was split into several parts and printed using a 3D printer in order to print the whole-body phantom. The newly printed physical phantom RFPID was successfully fabricated, and it is suitable to mimic human tissue, anatomically similar to a human body i.e., size, shape, material composition, and density.

Epidemiology of Clostridioides difficile Infection in Portugal: A Retrospective, Observational Study of Hospitalized Patients

INTRODUCTION

Clostridioides difficile is the main cause of healthcare-associated diarrhea in Europe and North America. The aim of this study was to characterize the epidemiology and clinical burden of Clostridioides difficile infection among hospitalized patients in Portugal.

MATERIAL AND METHODS

Retrospective study conducted in six public hospital centers in Portugal. All primary Clostridioides difficile infection episodes and related recurrences occurring in 2017, as well as episodes developing two to eight weeks after the last episode diagnosed in that year, were documented. The National Reference Laboratory (National Institute of Health Dr. Ricardo Jorge) provided national surveillance data on Clostridioides difficile infection.

RESULTS

A total of 385 inpatients with at least one primary episode diagnosed in 2017 were included. Most patients were aged over 70 years-old (73.2%). The included patients developed 451 episodes during the observation period. Approximately 44% of primary episodes were community-associated. Most episodes (94.9%) occurred in patients with one or more risk factors, with recent antibiotic exposure being particularly common (86.0%). All-cause in-hospital mortality was 19.5%, being significantly higher in patients aged over 65 years-old versus those aged 18 to 64 years-old (22.4% vs 7.8%, respectively). Over 50 different ribotypes were observed among 206 Clostridioides difficile strains received by the National Reference Laboratory.

CONCLUSION

In Portugal, hospitalized patients with Clostridioides difficile infection are mostly older patients presenting risk factors for the development of this infection, particularly recent antibiotic exposure. Mortality is disproportionately high among the older population. Community-associated Clostridioides difficile infection is common among inpatients with this infection.

Real-World Characterization of the Portuguese Population Living with HIV who Initiated Raltegravir Based-Regimens: The REALITY Study

INTRODUCTION

Although raltegravir has been available since 2007, data are lacking on the Portuguese population living with HIV who initiated this antiretroviral therapy. Hence, this study aimed to characterize the patients who initiated raltegravir-based regimens between January 2015 and December 2017, on sociodemographics, clinical features, and treatment satisfaction.

MATERIAL AND METHODS

Observational, retrospective, multicentre study conducted at 11 reference sites. Sociodemographic and clinical data were collected retrospectively from hospital medical records. For participants continuing raltegravir at study inclusion, the HIV Treatment Satisfaction Questionnaire was administered to assess satisfaction with raltegravir-based therapy. Descriptive statistics were performed. Treatment-naïve and treatment-experienced subgroups were compared for demographic and clinical variables.

RESULTS

A total of 302 patients were included; mostly men (69.5%) with a mean age of 49 years old. Approximately half of the patients had at least one non-AIDS-related comorbidity at baseline (53.3%), such as hypercholesterolemia, arterial hypertension, diabetes mellitus, and depression. Moreover, 52.3% were treatment-experienced patients with up to two treatments prior to raltegravir. Across the study time points, there was a reduction in the viral load and improvement in CD4 counts in both the treatment-naïve and treatment-experienced subgroups. Continuing users of raltegravir reported high treatment satisfaction (55.4 ± 7.2 points).

CONCLUSION

Raltegravir-based regimens seem like a valid therapeutic option in heterogeneous populations of HIV-infected patients, in patients with previous ART experience and as part of first-line therapeutic options alongside with the latest generation of drugs from its class.

Presence of Chromosomal crpP-like Genes Is Not Always Associated with Ciprofloxacin Resistance in Pseudomonas aeruginosa Clinical Isolates Recovered in ICU Patients from Portugal and Spain

CrpP enzymes have been recently described as a novel ciprofloxacin-resistance mechanism. We investigated by whole genome sequencing the presence of crpP-genes and other mechanisms involved in quinolone resistance in MDR/XDR-Pseudomonas aeruginosa isolates (n = 55) with both ceftolozane-tazobactam susceptible or resistant profiles recovered from intensive care unit patients during the STEP (Portugal) and SUPERIOR (Spain) surveillance studies. Ciprofloxacin resistance was associated with mutations in the gyrA and parC genes. Additionally, plasmid-mediated genes (qnrS2 and aac(6')-Ib-cr) were eventually detected. Ten chromosomal crpP-like genes contained in related pathogenicity genomic islands and 6 different CrpP (CrpP1-CrpP6) proteins were found in 65% (36/55) of the isolates. Dissemination of CrpP variants was observed among non-related clones of both countries, including the CC175 (Spain) high-risk clone and CC348 (Portugal) clone. Interestingly, 5 of 6 variants (CrpP1-CrpP5) carried missense mutations in an amino acid position (Gly7) previously defined as essential conferring ciprofloxacin resistance, and decreased ciprofloxacin susceptibility was only associated with the novel CrpP6 protein. In our collection, ciprofloxacin resistance was mainly due to chromosomal mutations in the gyrA and parC genes. However, crpP genes carrying mutations essential for protein function (G7, I26) and associated with a restored ciprofloxacin susceptibility were predominant. Despite the presence of crpP genes is not always associated with ciprofloxacin resistance, the risk of emergence of novel CrpP variants with a higher ability to affect quinolones is increasing. Furthermore, the spread of crpP genes in highly mobilizable genomic islands among related and non-related P. aeruginosa clones alert the dispersion of MDR pathogens in hospital settings.

Distinct epidemiology and resistance mechanisms affecting ceftolozane/tazobactam in Pseudomonas aeruginosa isolates recovered from ICU patients in Spain and Portugal depicted by WGS

Objectives

To analyse the epidemiology, the resistome and the virulome of ceftolozane/tazobactam-susceptible or -resistant Pseudomonas aeruginosa clinical isolates recovered from surveillance studies in Portugal (STEP, 2017–18) and Spain (SUPERIOR, 2016–17).

Methods

P. aeruginosa isolates were recovered from intra-abdominal, urinary tract and lower respiratory tract infections in ICU patients admitted to 11 Portuguese and 8 Spanish hospitals. MICs were determined (ISO-standard broth microdilution, EUCAST 2020 breakpoints). A subset of 28 ceftolozane/tazobactam-resistant P. aeruginosa isolates were analysed and compared with 28 ceftolozane/tazobactam-susceptible P. aeruginosa strains by WGS.

Results

Clonal complex (CC) 235 (27%) and CC175 (18%) were the most frequent, followed by CC244 (13%), CC348 (9%), CC253 (5%) and CC309 (5%). Inter-hospital clonal dissemination was observed, limited to a geographical region (CC235, CC244, CC348 and CC253 in Portugal and CC175 and CC309 in Spain). Carbapenemases were detected in 25 isolates (45%): GES-13 (13/25); VIM type (10/25) [VIM-2 (4/10), VIM-20 (3/10), VIM-1 (2/10) and VIM-36 (1/10)]; and KPC-3 (2/25). GES-13-CC235 (13/15) and VIM type-CC175 (5/10) associations were observed. Interestingly, KPC-3 and VIM-36 producers showed ceftolozane/tazobactam-susceptible phenotypes. However, ceftolozane/tazobactam resistance was significantly associated with GES-13 and VIM-type carbapenemase production. Six non-carbapenemase producers also displayed ceftolozane/tazobactam resistance, three of them showing known ceftolozane/tazobactam resistance-associated mutations in the PBP3 gene, ftsI (R504C and F533L). Overall, an extensive virulome was identified in all P. aeruginosa isolates, particularly in carbapenemase-producing strains.

Conclusions

GES-13-CC235 and VIM type-CC175 were the most frequent MDR/XDR P. aeruginosa clones causing infections in Portuguese and Spanish ICU patients, respectively. Ceftolozane/tazobactam resistance was mainly due to carbapenemase production, although mutations in PBP-encoding genes may additionally be involved.

Garbage codes as causes of death and quality of mortality statistics in Belo Horizonte, Brazil

Background

Quality of cause-of-death information is fundamental for health planning. Traditionally, this quality has been assessed by the analysis of ill-defined causes from chapter XVIII of the International Classification of Diseases - 10th revision (ICD-10). However, studies have considered other useless diagnoses for public health purposes, defined, in conjunction with ill-defined causes, as garbage codes (GC). In Brazil, despite the high completeness of the Mortality Information System, approximately 30% of deaths are attributable to GCs. This study aims to analyze the frequency of GCs in Belo Horizonte municipality, the capital of Minas Gerais state, Brazil.

Methods

Data of deaths from 2011 to 2013 in Belo Horizonte were analyzed. GCs were classified according to the GBD 2015 study list. These codes were classified in: a) GCs from chapter XVIII of ICD-10 (GC-R), and b) GC from other chapters of ICD-10 (GC-nonR). Proportions of GC were calculated by sex, age, and place of occurrence.

Results

In Belo Horizonte, from the total of 44,123 deaths, 5.5% were classified as GC-R. The majority of GCs were GC-nonR (25% of total deaths). We observed a higher proportion of GC in children (1 to 4 years) and in people aged over 60 years. GC proportion was also higher in females, except in the age-groups under 1 year and 30-59 years. Home deaths (n = 7,760) had higher proportions of GCs compared with hospital deaths (n = 30,182), 36.9% and 28.7%, respectively. The leading GCs were the GC-R other ill-defined and unspecified causes of death (ICD-10 code R99)), and the GCs-nonR unspecified pneumonia (J18.9), unspecified stroke (I64), and unspecified septicemia (A41.9).

Conclusions

Analysis of GCs is essential to evaluate the quality of mortality information.

Key messages

Analysis of ill-defined causes (GC-R) is not sufficient to evaluate the quality of information on causes of death. Causes of death analysis should consider the total GC, in order to advance the discussion and promote adequate intervention on the quality of mortality statistics.

Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism

Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonized by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose is the prevailing sugar. As a result during progression from colonization to disease S. pneumoniae has to cope with a pronounced shift in carbohydrate nature and availability. Thus, we set out to assess the pneumococcal response to sugars found in glycans and the influence of glucose (Glc) on this response at the transcriptional, physiological, and metabolic levels. Galactose (Gal), N-acetylglucosamine (GlcNAc), and mannose (Man) affected the expression of 8 to 14% of the genes covering cellular functions including central carbon metabolism and virulence. The pattern of end-products as monitored by in vivo¹³C-NMR is in good agreement with the fermentation profiles during growth, while the pools of phosphorylated metabolites are consistent with the type of fermentation observed (homolactic vs. mixed) and regulation at the metabolic level. Furthermore, the accumulation of α-Gal6P and Man6P indicate metabolic bottlenecks in the metabolism of Gal and Man, respectively. Glc added to cells actively metabolizing other sugar(s) was readily consumed and elicited a metabolic shift toward a homolactic profile. The transcriptional response to Glc was large (over 5% of the genome). In central carbon metabolism (most represented category), Glc exerted mostly negative regulation. The smallest response to Glc was observed on a sugar mix, suggesting that exposure to varied sugars improves the fitness of S. pneumoniae. The expression of virulence factors was negatively controlled by Glc in a sugar-dependent manner. Overall, our results shed new light on the link between carbohydrate metabolism, adaptation to host niches and virulence.

Host glycan sugar-specific pathways in Streptococcus pneumoniae: galactose as a key sugar in colonisation and infection [corrected]

The human pathogen Streptococcus pneumoniae is a strictly fermentative organism that relies on glycolytic metabolism to obtain energy. In the human nasopharynx S. pneumoniae encounters glycoconjugates composed of a variety of monosaccharides, which can potentially be used as nutrients once depolymerized by glycosidases. Therefore, it is reasonable to hypothesise that the pneumococcus would rely on these glycan-derived sugars to grow. Here, we identified the sugar-specific catabolic pathways used by S. pneumoniae during growth on mucin. Transcriptome analysis of cells grown on mucin showed specific upregulation of genes likely to be involved in deglycosylation, transport and catabolism of galactose, mannose and N acetylglucosamine. In contrast to growth on mannose and N-acetylglucosamine, S. pneumoniae grown on galactose re-route their metabolic pathway from homolactic fermentation to a truly mixed acid fermentation regime. By measuring intracellular metabolites, enzymatic activities and mutant analysis, we provide an accurate map of the biochemical pathways for galactose, mannose and N-acetylglucosamine catabolism in S. pneumoniae. Intranasal mouse infection models of pneumococcal colonisation and disease showed that only mutants in galactose catabolic genes were attenuated. Our data pinpoint galactose as a key nutrient for growth in the respiratory tract and highlights the importance of central carbon metabolism for pneumococcal pathogenesis.

Serotonergic 5-HT2A/2C receptors are involved in prolactin secretion in hyperestrogenic rats

Serotonin (5-HT) has been shown to participate in prolactin secretion through a complex process resulting in both positive and negative effects. Estrogen has also been recognized as being involved in this serotonergic effect on prolactin release. Therefore, the aim of the present study was to assess whether estradiol modulates serotonergic involvement in prolactin secretion though 5-HT1A and/or 5-HT2A/2C receptors. Ovariectomized female Wistar rats, treated for 2 weeks with estrogen to induce a hyperprolactinemic status (hyperestrogenic rats) or with sunflower oil vehicle (hypoestrogenic rats), were injected daily with normal saline solution or 6-chloro-2-(1-piperazinyl)pyrazine (MK-212), an 5-HT2A/2C receptor agonist, for 4 days. Other groups of ovariectomized animals received 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) or pindolol, an agonist and antagonist of the 5-HT1A receptor respectively, on the last day of treatment with estrogen or vehicle. Prolactin levels were compared among groups in each experiment under the distinct drug treatments. MK-212 was found to increase prolactin concentrations both in hyper- and hypoestrogenic females compared to controls (p<0.05). In contrast, prolactin levels remained similar to those of controls both in hyperestrogenic animals treated with 8-OH-DPAT and pindolol and in hypoestrogenic rats administered the same treatments. In conclusion, our findings indicate the involvement of 5-HT2A/2C receptors on prolactin release through serotonergic pathways in female animals, especially in hyperestrogenic states.

BGFit: management and automated fitting of biological growth curves

BACKGROUND

Existing tools to model cell growth curves do not offer a flexible integrative approach to manage large datasets and automatically estimate parameters. Due to the increase of experimental time-series from microbiology and oncology, the need for a software that allows researchers to easily organize experimental data and simultaneously extract relevant parameters in an efficient way is crucial.

RESULTS

BGFit provides a web-based unified platform, where a rich set of dynamic models can be fitted to experimental time-series data, further allowing to efficiently manage the results in a structured and hierarchical way. The data managing system allows to organize projects, experiments and measurements data and also to define teams with different editing and viewing permission. Several dynamic and algebraic models are already implemented, such as polynomial regression, Gompertz, Baranyi, Logistic and Live Cell Fraction models and the user can add easily new models thus expanding current ones.

CONCLUSIONS

BGFit allows users to easily manage their data and models in an integrated way, even if they are not familiar with databases or existing computational tools for parameter estimation. BGFit is designed with a flexible architecture that focus on extensibility and leverages free software with existing tools and methods, allowing to compare and evaluate different data modeling techniques. The application is described in the context of bacterial and tumor cells growth data fitting, but it is also applicable to any type of two-dimensional data, e.g. physical chemistry and macroeconomic time series, being fully scalable to high number of projects, data and model complexity.

Seasonality and psychiatric disorders

Introduction

Season mood changes are a phenomenon recognised by almost everyone. Who did never experience a little energy decrease or light depressive feelings with the beginning of Autumn or Winter? And the season recurrence of some Psychiatric Disorders, like MDD and BD are sufficiently acknowledged by patients and specialists. There is even a nosologic entity called Seasonal Affective Disorder, which shows more prevalence among Nordic places (where winter days are shorter) and in which light therapy seems a good therapeutic option. Not only in Psychiatry the properties of light therapy were recognised, NR Finsen won the Nobel Prize in 1903 for his work with Heliotherapy (found benefits with sun exposure in some skin diseases). There are various theories that try to explain those assumptions, like summer-winter difference in duration of nightly melatonin release, inability to synchronize circadian rhythms with sleep/wake rhythms and even Vitamin D production.

Aims/objectives

The aim of this work consists on a scientific revision of the origins and the influence extension of seasonality in Psychiatric Disorders (PD) and in therapeutic implications, particularly with some new anti-depressants.

Methods

We make a bibliographic investigation about more recent findings in origins and influence extension of seasonality in PD and the role of new psychopharmacologic approaches in these cases.

Results

There are some scientific papers in which those maters are analysed.

Conclusion

There are some scientific theories about the mechanisms and degree of influence of seasonality in some PD, but the whole process have not been explained nor have been tested.

Bipolar disorder in childhood and adolescence

Introduction

The diagnosis of Bipolar Disorder (BD) is still controversial in the early stages of life, not only because of its difficulty, but also because of the precaution of professionals with this diagnosis, since it is a chronic illness.

Aims

To review and synthesize available information about paediatric BD.

Methods

The authors consulted, selected and reviewed information concerning the theme, mainly searched on-line articles.

Results

It is difficult to diagnose BD in youths, considering the fewer specific symptoms and the high co-morbidity.

Conclusions

Despite some disagreement on this diagnosis, BD is a valid clinical entity in children and adolescents.

Fluorometric determination of ethidium bromide efflux kinetics in Escherichia coli

Background

Efflux pump activity has been associated with multidrug resistance phenotypes in bacteria, compromising the effectiveness of antimicrobial therapy. The development of methods for the early detection and quantification of drug transport across the bacterial cell wall is a tool essential to understand and overcome this type of drug resistance mechanism. This approach was developed to study the transport of the efflux pump substrate ethidium bromide (EtBr) across the cell envelope of Escherichia coli K-12 and derivatives, differing in the expression of their efflux systems.

Results

EtBr transport across the cell envelope of E. coli K-12 and derivatives was analysed by a semi-automated fluorometric method. Accumulation and efflux of EtBr was studied under limiting energy supply (absence of glucose and low temperature) and in the presence and absence of the efflux pump inhibitor, chlorpromazine. The bulk fluorescence variations were also observed by single-cell flow cytometry analysis, revealing that once inside the cells, leakage of EtBr does not occur and that efflux is mediated by active transport. The importance of AcrAB-TolC, the main efflux system of E. coli, in the extrusion of EtBr was evidenced by comparing strains with different levels of AcrAB expression. An experimental model was developed to describe the transport kinetics in the three strains. The model integrates passive entry (influx) and active efflux of EtBr, and discriminates different degrees of efflux between the studied strains that vary in the activity of their efflux systems, as evident from the calculated efflux rates: = 0.0173 ± 0.0057 min^-1; = 0.0106 ± 0.0033 min^-1; and = 0.0230 ± 0.0075 min^-1.

Conclusion

The combined use of a semi-automated fluorometric method and an experimental model allowed quantifying EtBr transport in E. coli strains that differ in their overall efflux activity. This methodology can be used for the early detection of differences in the drug efflux capacity in bacteria accounting for antibiotic resistance, as well as for expedite screening of new drug efflux inhibitors libraries and transport studies across the bacterial cell wall.

Depression in Multiple Sclerosis: A Case Report

Introduction:

Depression is the predominant psychological disturbance in Multiple Sclerosis (MS) with lifetime prevalence around 50% and annual prevalence of 20%. Depression is commoner during relapses and may exacerbate fatigue and cognitive dysfunction. The aetiology of depression is multifactorial and likely associated with psychological stress, focal demyelinating lesions and immune dysfunction. There is no correlation between age, gender, duration of illness and sex. Unlike it was believed for the treatment with interferon β, recent side effects data from clinical trials have failed to confirm that this medication is associated with an increased risk of depression in patients with MS. Treating depression improves quality of life and improves adherence to disease-modifying drugs. Treatment with pharmacotherapy is particularly challenging given the somatic symptoms overlap between MS and depression and the increased burden of their side effects.

Aims:

To demonstrate the relationship between depression and MS.

Methods:

We report a case of depression in a 32 year old woman with MS, treated twice with bolus of metilprednisolone, taking interferon β at present. Her psychopathological symptoms have been sadness, terminal insomnia, anorexia, fatigue, social isolation, anhedonia, increased worry, pessimism, loss of self-esteem and suicidal ideation (not structured). The pharmacotherapy used to treat the depression was firstly fluoxetine and lately venlafaxine.

Results:

There has been an improvement on the patient's symptoms related both to the depression and to the MS.

Conclusions:

This case demonstrates once more, the complex relationship between those two clinical entities.