Dynamic Exosome Analysis to Predict Response to the Combination of SABR and Immunotherapy in Oligoprogressive Disease

PURPOSE/OBJECTIVE(S)

Up to 80% of metastatic patients face resistance to immune checkpoint inhibitors (ICI). Combined SABR and ICI (I-SABR) can unleash antitumor immune cascades to overcome resistance and improve response with minimal toxicity. This synergy is particularly interesting in the oligoprogressive setting to extend the clinical benefit (CB) of ICI. However, there are no current biomarkers for patient selection. We hypothesize that differential expression of exosomal RNA in liquid biopsy may predict response to I-SABR.

MATERIALS/METHODS

Ongoing prospective multicenter study in two cohorts. Cohort A consists of metastatic patients in oligoprogression to ICI (1-5 extracranial sites) but maintaining the same ICI due to CB and who receive concomitant SABR (35 Gy in 5 fractions, fx) to oligoprogressive sites. Cohort B is a comparative group of oligometastatic patients receiving only SABR in ablative doses. Blood samples are extracted before SABR (T1), after the first (T2) and last (T3) fx, two months post-SABR (T4) and at further progression (TP). Response is evaluated by iRECIST and defined by the objective response rate (ORR) in all lesions (in and out-of-field)- complete and partial responses. For exosome analysis, we perform RNA isolation and small RNA sequencing from plasma. We use Cutadapt, Bowtie and featureCounts to quantify the number of reads of miRNA, small nuclear RNA (snRNA) and small nucleolar RNA (snoRNA). Pairwise differences in expression in responders and non-responders are examined by DESeq2 differential expression analysis. Differentially expressed transcripts are consulted in Ingenuity Pathway Analysis (IPA).

RESULTS

Of 22 patients recruited, we present preliminary results of the first 10 (8 from cohort A and 2 from B) that had undergone re-evaluation after SABR. Most frequent cancer types were lung (60%) and renal cell (20%). Seventy percent were polymetastatic (>5 lesions) and 90% had a single progressing site. Pembrolizumab (40%) and Nivolumab (30%) were the most frequent ICI. Most lesions for SABR were lung (45%). With a median follow-up of 7.1 months (95% CI, 3.7-10.6) ORR at two months was 60% (6 partial responses, 1 stable disease and 3 progressions). Median progression-free survival was 10.3 months (95% CI, 3.7-not reached) and median overall survival was not reached. Seven patients in cohort A were available for small RNA analysis. We identified 3 miRNA, 24 snRNA and 9 snoRNA that were significantly differentially expressed at T1. Hsa-miR-493, marker of tumor progression, was upregulated in non-responders. RN7SK inhibits LAS1L (a known inductor of metastasis in lung cancer) and was upregulated in responders. SNORD71, which is inhibited by ILF3 (promotor of progression), was also upregulated in responders.

CONCLUSION

I-SABR is an effective approach for extending CB of ICI in oligoprogressive patients. Exosomal RNA expression analysis in liquid biopsy is a novel and non-invasive technique that may predict response to this combination and aid in patient selection.

A pro-BMP function exerted by Rhodnius prolixus short gastrulation reveals great diversity in the role of BMP modulators during embryonic patterning

Dorsal-ventral (DV) patterning is regulated by the bone morphogenetic pathway (BMP) in Bilateria. In insect DV patterning, the Toll pathway also plays a role, in addition to BMPs. Variations in the relative importance of each pathway for DV patterning have been reported using single species of coleopteran, hymenopteran, hemipteran and orthopteran insects. To investigate if the molecular control of DV patterning is conserved inside an insect order, the emergent model hemiptera species Rhodnius prolixus was studied. We found that R. prolixus BMP pathway controls the entire DV axis, with a broader effect respective to Toll, as shown for the hemiptera Oncopeltus fasciatus. Different from O. fasciatus, the unique R. prolixus short gastrulation (sog) and the twisted gastrulation (tsg) orthologues do not antagonize, but rather favour embryonic BMP signalling. Our results reinforce the hypothesis that hemiptera rely preferentially on BMPs for DV patterning but that, surprisingly, in R. prolixus Sog and Tsg proteins exert only a positive role to establish a dorsal-to-ventral BMP gradient. Since sog has been reported to be lost from orthopteran and hymenopteran genomes, our results indicate that Sog's role to modify BMP activity varies greatly in different insect species.

Radiation protection measures used in Portuguese interventional radiology departments: A national survey

INTRODUCTION

This study aimed to characterise radiation protection (RP) measures used in interventional radiology (IR) departments in Portugal with respect to European and national recommendations.

METHODS

An online national survey was created to characterise the fluoroscopy technology as well as analyse the frequency of body fluoroscopy-guided intervention procedures (FGIP), RP education and training of the staff, and RP measures used daily.

RESULTS

In Portugal, most equipment for FGIP are single-sourced and have a flat panel detector (70%). The most commonly FGIP are percutaneous biliary drainage, percutaneous arterial and venous thrombolysis/thrombectomy, arteriovenous malformations embolization, and percutaneous transluminal balloon angioplasty for arteriovenous fistulas. Only a few staff members had received postgraduate education and training in RP (30%), with most nurses having not received RP education and training (40%). Some of the recommended RP measures lacked harmonisation. Additionally, >50% of the IR departments do not consider examination dose values to identify patients eligible for tissue reactions follow-up.

CONCLUSION

This is the first study to examine the characteristics of IR departments in Portugal. We observed a lack of RP education and training among staff members; further, there was a need to update some RP measures in some IR departments according to the recommendations.

IMPLICATIONS FOR PRACTICE

Our findings will be presented to the participating IR departments in order to update and promote RP best practices. Moreover, our findings will be presented to the national societies of the different professional groups in order to inform strategies for harmonising RP education and training of the staff.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

OUP accepted manuscript

Optimization of metabolism to maximize production of bio-based chemicals must consistently balance cellular resources for biocatalyst growth and desired compound synthesis. This mini-review discusses synthetic biology strategies for dynamically controlling expression of genes to enable dual-phase fermentations in which growth and production are separated into dedicated phases. Emphasis is placed on practical examples which can be reliably scaled to commercial production with the current state of technology. Recent case studies are presented, and recommendations are provided for environmental signals and genetic control circuits.

Microbiome - a (FUTURE) marker for the differential diagnosis for autism spectrum disorder and attention-deficit/hyperactivity disorder?

Introduction

The differential diagnosis between Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD) is often challenging and detrimental to early and timely treatment. Co-current and overlapping symptoms contribute to erode differential diagnostic accuracy, based mainly on clinical assessment supported by standardized instruments and reports from parents and teachers. The microbiota was recently considered a valuable resource in the search for biological markers in neurodevelopmental disorders.

Objectives

Our objective was to examine the published literature in order to clarify the role of the microbiome as a possible differential biomarker between ASD and ADHD.

Methods

Five hundred and sixteen articles were reviewed in order to contextualize the role of Gut- Brain Axis in neurodevelopment and neurodevelopmental disorders, the microbiome as a biomarker and ultimately to unravel microbiome abnormalities reported in patients diagnosed with ASD and/or ADHD.

Results

Although gut microbiome appears to be involved in the pathogenesis of ASD with several reports identifying changes in gut populations and functions, a “microbial signature” is still not reached. In ADHD patients, research confirms that the composition and predicted functions of gut microbiome are also altered, but identically controversial results were found.

Conclusions

Future studies are needed to confirm the relationship between the composition and function of the microbiome and the occurrence or presentation of each of the disorders. A specific signature of the microbiota could then constitute itself as a differential biomarker in ASD and ADHD.

Predicting lung nodules malignancy

BACKGROUND

It is critical to developing an accurate method for differentiating between malignant and benign solitary pulmonary nodules. This study aimed was to establish a predicting model of lung nodules malignancy in a real-world setting.

METHODS

The authors retrospectively analysed the clinical and computed tomography (CT) data of 121 patients with lung nodules, submitted to percutaneous CT-guided transthoracic biopsy, between 2014 and 2015. Multiple logistic regression was used to screen independent predictors for malignancy and to establish a clinical prediction model to evaluate the probability of malignancy.

RESULTS

From a total of 121 patients, 75 (62%) were men and with a mean age of 64.7 years old. Multivariate logistic regression analysis identified six independent predictors of malignancy: age, gender, smoking status, current extra-pulmonary cancer, air bronchogram and nodule size (p<0.05). The area under the curve (AUC) was 0.8573.

CONCLUSIONS

The prediction model established in this study can be used to assess the probability of malignancy in the Portuguese population, thereby providing help for the diagnosis of lung nodules and the selection of follow-up interventions.

Clinical utility of plasma-based digital next-generation sequencing in patients with advance-stage lung adenocarcinomas with insufficient tumor samples for tissue genotyping

BACKGROUND

Approximately 30% of tumor biopsies from patients with advanced-stage lung adenocarcinomas yield insufficient tissue for successful molecular subtyping. We have analyzed the clinical utility of next-generation sequencing (NGS) of cell-free circulating tumor DNA (ctDNA) in patients with inadequate tumor samples for tissue genotyping.

PATIENTS AND METHODS

We conducted the study in a multi-institutional prospective cohort of clinically unselected patients with advanced-stage lung adenocarcinomas with insufficient tissue for EGFR, ALK or ROS1 genotyping across 12 Spanish institutions (n = 93). ctDNA NGS was carried out by Guardant Health (Guardant360, Redwood City, CA), using a hybrid-capture-based 73-gene panel. Variants were deemed actionable if they were part of the OncoKB precision oncology knowledge database and classified in four levels of actionability based on their clinical or preclinical evidence for drug response.

RESULTS

Eighty-three out of 93 patients (89%) had detectable levels of ctDNA. Potentially actionable level 1-4 genomic alterations were detected in 53 cases (57%), of which 13 (14%) had level 1-2A alterations (Food and Drug Administration-approved and standard-care biomarkers according to lung cancer guidelines). Frequencies of each genomic alteration in ctDNA were consistent with those observed in unselected pulmonary adenocarcinomas. The majority of the patients (62%), particularly those with actionable alterations (87%), had more than one pathogenic variant in ctDNA. The median turnaround time to genomic results was 13 days. Twelve patients (13%) received genotype-matched therapies based on ctDNA results, deriving the expected clinical benefit. Patients with co-occurring pathogenic alterations had a significantly shorter median overall survival as compared with patients without co-occurring pathogenic alteration (multivariate hazard ratio = 5.35, P = 0.01).

CONCLUSION

Digital NGS of ctDNA in lung cancers with insufficient tumor samples for tissue sequencing detects actionable variants that frequently co-occur with other potentially clinically relevant genomic alterations, allowing timely initiation of genotype-matched therapies.

LRP5 gene polymorphisms and radiographic joint damage in rheumatoid arthritis patients

Rheumatoid arthritis (RA) is characterized by increased bone resorption and impaired bone formation. Osteoblast function is regulated by the canonical LRP5/Wnt/β-catenin pathway. Bone mineral density and RA joint destruction are partially inherited. In line with this, we found significant associations between LRP5 SNPs (p.A1330V, p.N740N, p.V667M) and RA radiographic damage severity.

INTRODUCTION

Increased bone resorption and impaired bone formation characterize rheumatoid arthritis (RA). Canonical Wnt/β-catenin pathway, signalled by lipoprotein receptor-related protein-5 (LRP5), regulates osteoblast function. Since bone mineral density (BMD) and RA joint destruction are partially inherited, we studied their association with LRP5 single nucleotide polymorphisms (SNPs).

METHODS

Clinical data and peripheral blood for biomarkers assessment and LRP5 genotyping were collected from 208 RA patients. Hands and feet X-rays were scored [modified Sharp/van der Heijde Score (SHS), joint space narrowing (JSN), and erosion scores]. Lumbar spine, total left proximal femur, and left hand BMD were assessed by dual-energy X-ray absorptiometry (DXA).

RESULTS

TT genotypes for p.A1330V and p.N740N LRP5 SNPs associated with total SHS, erosion score, and hands erosion score; the same for p.A1330V with feet JSN score and p.N740N with hands total score. AG genotype for p.V667M associated with sclerostin and hands JSN score. Femoral BMD associated with TC genotype for p.N740N. Multiple test correction precluded a few of these associations. Among V667M-N740N-A1330V haplotypes: GTT associated with higher feet JSN score (OR = 3.80; p = 0.016) and ATT with higher JSN score (OR = 4.60; p = 0.032), hands total score (OR = 5.65; p = 0.022), and total SHS (OR = 6.74; p = 0.024).

CONCLUSION

Significant associations between LRP5 SNPs (p.A1330V, p.N740N, and p.V667M) and the severity of radiographic damage reinforce the evidence of bone destruction heritability in RA.

Morbidity and mortality outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients aged 75 years and over: Spanish group of peritoneal cancer surgery (GECOP) multicenter study

BACKGROUND

The aim of this study is to report the perioperative outcomes of cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) in patients ≥75 years from a Spanish multi-institutional experience.

METHODS

This multi-institutional retrospectively analyzed a prospectively collected clinical data from 10 Spanish hospitals that are part of the Spanish Group Peritoneal Cancer Surgery (GECOP). We assessed postoperative morbidity rates and performed univariate and multivariate analyses of factors associated with overall (grade I-IV) and major (grade III-IV) postoperative morbidity.

RESULTS

A total of 85 patients aged ≥75 years were included. Forty six postoperative adverse events were detected in 37 patients (43.5%). Twenty five complications in 20 patients (23.5%) were mild (grade I-II) and 16 complications in 12 patients (14.1%) were moderate-severe (grade III-IV). Five patients died in the first 90 days after the procedure (5.9%). After multivariate analysis, independent factors associated with postoperative complications were: PCI> 12 (OR: 4.14, 95% CI 1.22-14.12, p = 0.043) and the need for perioperative blood transfusion (OR: 14.91, 95% CI 3.87-57.46, p < 0.001). Regarding grade III-IV complications, after multivariate analysis, the presence of preoperative albumin levels <3.5 mgr/dl (OR: 9.15, 95% CI 1.38-60.57, p = 0.017), need for diaphragmatic peritonectomy procedures (OR: 11.32, 95% CI 1.40-91.32, p = 0.023) and perioperative blood transfusion (OR: 8.58, 95% CI 1.44-51.16, p = 0.018) were independent factors.

CONCLUSIONS

Cytoreductive surgery and performing HIPEC by experienced groups in selected patients aged ≥75 years can be performed with morbidity and mortality similar to that described in the literature.

Definition of redox and pH influence in the AMD mine system using a fuzzy qualitative tool (Iberian Pyrite Belt, SW Spain)

Poderosa Mine is an abandoned pyrite mine, located in the Iberian Pyrite Belt which pours its acid mine drainage (AMD) waters into the Odiel river (South-West Spain). This work focuses on establishing possible reasons for interdependence between the potential redox and pH, with the load of metals and sulfates, as well as a set of variables that define the physical chemistry of the water-conductivity, temperature, TDS, and dissolved oxygen-transported by a channel from Poderosa mine affected by acid mine drainage, through the use of techniques of artificial intelligence: fuzzy logic and data mining. The sampling campaign was carried out in May of 2012. There were a total of 16 sites, the first inside the tunnel and the last at the mouth of the river Odiel, with a distance of approximately 10 m between each pair of measuring stations. While the tools of classical statistics, which are widely used in this context, prove useful for defining proximity ratios between variables based on Pearson's correlations, in addition to making it easier to handle large volumes of data and producing easier-to-understand graphs, the use of fuzzy logic tools and data mining results in better definition of the variations produced by external stimuli on the set of variables. This tool is adaptable and can be extrapolated to any system polluted by acid mine drainage using simple, intuitive reasoning.

Quelqu’un pense à moi

L’objectif de cette communication est de rendre compte d’une démarche sociologique d’évaluation d’un programme de veille des conduites suicidaires : ALGOS . ALGOS est une étude nationale multicentrique (23 centres) de l’efficacité d’un algorithme de recontact après une tentative de suicide (carte ressource avec numéro d’urgence, appels téléphoniques et/ou cartes postales). Mille cinquante-cinq suicidants ont été inclus suite à leur passage aux urgences. Comment les différentes catégories d’acteurs (psychiatres, psychologues, généralistes, cellule de recontact, urgentistes, suicidants) ont-ils pu se sentir impliqués dans ce programme ? La méthodologie adoptée pour accéder aux comportements d’appropriation du dispositif est triple :

– des entretiens semi-directifs téléphoniques avec des médecins traitants (n = 10), psychiatres (n = 10) et psychologues (n = 3) suivant les patients en soins courants ;

– des entretiens semi-directifs en face à face avec les psychologues (n = 4) et attachées de recherche clinique (n = 2) de la cellule de recontact du centre d’investigation clinique et avec des patients (n = 29) ayant participé au programme ;

– des focus groupes (3) avec les professionnels des urgences (n = 27) ayant inclus les patients dans le programme.

L’implication de la cellule de recontact apparaît comme un atout majeur du dispositif qui transparaît dans le discours et le vécu subjectif des suicidants à travers la conviction : « Quelqu’un pense à moi ». La majorité des médecins, psychiatres et psychologues n’ont pas eu un sentiment d’implication dans le programme. Les professionnels des urgences ont eu des réactions très variées qui ne sont cependant pas corrélées avec le nombre d’inclusions. La majorité de ces professionnels a « joué le jeu ». Le programme semble être plus adapté à un profil spécifique de participants. Ces résultats sont mis en perspective par rapport à la discussion dans la littérature internationale .

Do asymptomatic former high-impact sports practitioners maintain the ability to contract the pelvic floor muscles?

AIM

Sports are associated with pelvic floor dysfunction. This work aimed to assess, in nulliparous asymptomatic women, whether previous intense practice of high-impact sports is associated with differences in morphology and contraction of the pelvic floor muscles, when compared to women who practiced low-level physical activity.

METHODS

In this prospective pilot study, 7 former high-impact sports practitioners and a control group (N.=7) were compared. Clinical evaluation and self-administered questionnaires were used to gather information about pelvic floor dysfunction and physical activity. Static and cine dynamic MR images were acquired. Morphological measures of the pubovisceral muscle area and thickness, and levator hiatus (LH) anterior-to-posterior diameter, width and area were taken in the static images. LH anterior-to-posterior diameter was again assessed in the dynamic acquisition (consecutive blocks of rest vs. maximal voluntary contraction). The relative variation between these two conditions was used as an indirect measure of contraction.

RESULTS

No abnormal clinical or imaging findings were reported. Former high-impact sports practitioners evidenced decreased pubovisceral muscle thickness (right side P=0.005; left side P=0.004) and area (P=0.004), and larger levator hiatus width and area (P=0.045; P=0.005). Only its anterior-to-posterior diameter was similar (4.89cm±0.35 and 4.81cm±0.17, respectively). Their ability to perform maximum voluntary contractions seems to have decreased (8.03%±0.81 vs. 13.74%±0.95 for controls).

CONCLUSION

The current results suggest that women who previously practiced high-impact sports, even being asymptomatic, may have suffered damage to the pelvic floor muscles due to the biomechanical impact of the sports. They may require pelvic floor muscle training to increase muscle thickness and hiatal closing capacity.

Economic analysis of microaerobic removal of H2S from biogas in full-scale sludge digesters

The application of microaerobic conditions during sludge digestion has been proven to be an efficient method for H2S removal from biogas. In this study, three microaerobic treatments were considered as an alternative to the technique of biogas desulfurization applied (FeCl3 dosing to the digesters) in a WWTP comprising three full-scale anaerobic reactors treating sewage sludge, depending on the reactant: pure O2 from cryogenic tanks, concentrated O2 from PSA generators, and air. These alternatives were compared in terms of net present value (NPV) with a fourth scenario consisting in the utilization of iron-sponge-bed filter inoculated with thiobacteria. The analysis revealed that the most profitable alternative to FeCl3 addition was the injection of concentrated O2 (0.0019 €/m(3) biogas), and this scenario presented the highest robustness towards variations in the price of FeCl3, electricity, and in the H2S concentration.

Combined anti CXC receptors 1 and 2 therapy is a promising anti-inflammatory treatment for respiratory diseases by reducing neutrophil migration and activation

Neutrophil infiltration and activation in the lung are important pathophysiological features in COPD, severe asthma and bronchiectasis mostly mediated by CXCL8 and CXCL1 via CXCR1 and CXCR2. No thorough study to date has been performed to compare the anti-inflammatory effect profile of dual CXCR1/2 vs. selective CXCR2 antagonists in relevant human neutrophil assays and pulmonary inflammation models. Dual CXCR1/2 (SCH527123, diaminocyclobutandione-1) and selective CXCR2 (SB265610, thiopyrimidine-1) antagonist activity and receptor residence time were determined by [(35)S]GTPγS binding in human (h)- and guinea pig (gp)-CXCR1 and CXCR2 overexpressing membranes. h-neutrophil chemotaxis, degranulation and ROS production were established using CXCL8 or CXCL1 to evaluate dual CXCR1/2- or selective CXCR2-dependent activities. LPS-induced lung inflammation in gp was selected to assess in vivo potency. Dual CXCR1/2 antagonists blocked both CXCL8 and CXCL1-induced h-neutrophil functions and [(35)S]GTPγS binding. In contrary, selective CXCR2 antagonists displayed significantly reduced potency in CXCL8 -mediated h-neutrophil responses despite being active in CXCR2 assays. Upon LPS challenge in gp, administration of SCH527123 inhibited the increase of neutrophils in BALF, modestly reduced blood neutrophils and induced minor neutrophil accumulation in bone marrow. Differentiation of CXCR1/2 vs. CXCR2 antagonists could not be extended to in vivo due to differences in CXCR1 receptor homology between h and gp. Dual CXCR1/2 therapy may represent a promising anti-inflammatory treatment for respiratory diseases reducing more effectively neutrophil migration and activation in the lung than a CXCR2 selective treatment. However, the in vivo confirmation of this claim is still missing due to species differences in CXCR1.

Where does the removal of H₂S from biogas occur in microaerobic reactors?

In order to maximise the efficiency of biogas desulphurisation and reduce the oxygen cost during microaerobic digestion, it is essential to know how the process occurs. For this purpose, a reactor with a total volume of 266 L, treating 10 L/d of sewage sludge, was operated with 25.0 L and without headspace. Under anaerobic conditions, the H2S concentration in the biogas varied between 0.21 and 0.38%v/v. Next, O2 was supplied from the bottom of the reactor. At 0.25-0.30 NLO₂/Lfed, the biogas was entirely desulphurised, and its O₂ content remained below 1.03%v/v, when the digester had 25.0 L of gas space. However, with almost no headspace, the H2S content in the biogas fluctuated from 0.08 to 0.21%v/v, while the average O2 concentration was 1.66%v/v. The removed H2S accumulated in the outlet pipe of the biogas in the form of S(0) due to the insufficient headspace.

Pain in multiple sclerosis: a systematic review of neuroimaging studies

Introduction

While pain in multiple sclerosis (MS) is common, in many cases the precise mechanisms are unclear. Neuroimaging studies could have a valuable role in investigating the aetiology of pain syndromes. The aim of this review was to synthesise and appraise the current literature on neuroimaging studies of pain syndromes in MS.

Methods

We systematically searched PubMed and Scopus from their inception dates to the 2nd of April 2013. Studies were selected by predefined inclusion and exclusion criteria. Methodological quality was appraised. Descriptive statistical analysis was conducted.

Results

We identified 38 studies of variable methodology and quality. All studies but one used conventional structural magnetic resonance imaging, and the majority reported a positive association between location of demyelinating lesions and specific neuropathic pain syndromes. Most investigated headache and facial pain, with more common pain syndromes such as limb pain being relatively understudied. We identified a number of methodological concerns, which along with variable study design and reporting limit our ability to synthesise data. Higher quality studies were however less likely to report positive associations of lesion distribution to pain syndromes.

Conclusions

Further high quality hypothesis-driven neuroimaging studies of pain syndromes in MS are required to clarify pain mechanisms, particularly for the commonest pain syndromes.

•

We reviewed neuroimaging studies of pain syndromes in multiple sclerosis (MS).

•

All studies investigated neuropathic pain or headache, mainly using structural MRI.

•

Most reported associations between location of demyelinating lesions and pain.

•

Culprit lesions were most commonly reported in the brainstem.

•

High quality hypothesis-driven neuroimaging studies of pain in MS are still needed.

Microaerobic digestion of sewage sludge on an industrial-pilot scale: the efficiency of biogas desulphurisation under different configurations and the impact of O2 on the microbial communities

Biogas produced in an industrial-pilot scale sewage sludge reactor (5m(3)) was desulphurised by imposing microaerobic conditions. The H2S concentration removal efficiency was evaluated under various configurations: different mixing methods and O2 injection points. Biogas was entirely desulphurised under all the configurations set, while the O2 demand of the digester decreased over time. Although the H2S removal seemed to occur in the headspace, S(0) (which was found to be the main oxidation product) was scarcely deposited there in the headspace. O2 did not have a significant impact on the digestion performance; the VS removal remained around 47%. Conversely, DGGE revealed that the higher O2 transfer rate to the sludge maintained by biogas recirculation increased the microbial richness and evenness, and caused an important shift in the structure of the bacterial and the archaeal communities in the long term. All the archaeal genera identified (Methanosaeta, Methanospirillum and Methanoculleus) were present under both anaerobic and microaerobic conditions.

Diffusion-weighted imaging: determination of the best pair of b-values to discriminate breast lesions

OBJECTIVE

In breast diffusion-weighted imaging (DWI), the apparent diffusion coefficient (ADC) is used to discriminate between malignant and benign lesions. As ADC estimates can be affected by the weighting factors, our goal was to determine the optimal pair of b-values for discriminating breast lesions at 3.0 T.

METHODS

152 females with 157 lesions (89 malignant and 68 benign) underwent breast MRI, including a DWI sequence sampling six b-values 50, 200, 400, 600, 800 and 1000 s mm(-2). ADC values were computed from different pairs of b-values and compared with ADC obtained by fitting the six b-values using a mono-exponential diffusion model (ADCall). Cut-off ADC values were determined and diagnostic performance evaluated by receiver operating characteristic analysis using Youden statistics. Mean ADCs were determined for normal tissue and lesions. Differences were evaluated by lesion and histological types.

RESULTS

Considering the cut-off values 1.46 and 1.49 × 10(3)mm(2) s(-1), the pairs 50, 1000 and 200, 800 s mm(-2) showed the highest accuracy, 77.5% and 75.4% with areas under the curve 84.4% and 84.2%, respectively. The best pair for ADC quantification was 50, 1000 s mm(-2) with 38/49 true-negative and 69/89 true-positive cases respectively; mean ADCs were 1.86 ± 0.46, 1.77 ± 0.37 and 1.15 ± 0.46 × 10(-3) mm(2) s(-1) for normal, benign and malignant lesions. There were no significant differences in these ADC values when compared with ADCall (ADC calculated from the full set of b - values) [difference = 0.0075 × 10(-3) mm(2) s(-1); confidence interval 95%: (-0.0036; 0.0186); p = 0.18].

CONCLUSION

The diagnostic performance in differentiating malignant and benign lesions was most accurate for the b-value pair 50, 1000 s mm(-2).

ADVANCES IN KNOWLEDGE

The best b-value pair for lesion discrimination and characterization through ADC quantification was 50, 1000 s mm(-2).

The headspace of microaerobic reactors: sulphide-oxidising population and the impact of cleaning on the efficiency of biogas desulphurisation

O2-limiting/microaerobic conditions were applied in order to control the H2S content of biogas. The S(0)-rich deposits found all over the headspace of two pilot reactors (R1 and R2) as a result of operating under such conditions for 7 and 15 months (respectively) were sampled and removed. After restarting micro-oxygenation, H2S-free biogas was rapidly obtained, and the O2 demand of R2 decreased. This highlighted the need for a cleaning interval of less than 14 months in order to minimise the micro-oxygenation cost. The H2S removed from R2 after approximately 1 month was recovered from its headspace as S(0), thus indicating that the biogas desulphurisation did not take place at the liquid interface. Denaturing gradient gel electrophoresis indicated that the composition, species richness and size of the sulphide-oxidising bacteria population depended on the location, and, more specifically, moisture availability, and indicated increasing species richness over time. Additionally, a possible succession was estimated.

Lack of activity of 15-epi-lipoxin A₄ on FPR2/ALX and CysLT1 receptors in interleukin-8-driven human neutrophil function

Neutrophil recruitment and survival are important control points in the development and resolution of inflammatory processes. 15-epi-lipoxin (LX)A interaction with formyl peptide receptor 2 (FPR2)/ALX receptor is suggested to enhance anti-inflammatory neutrophil functions and mediate resolution of airway inflammation. However, it has been reported that 15-epi-LXA₄ analogues can also bind to cysteinyl leukotriene receptor 1 (CysLT1) and that the CysLT1 antagonist MK-571 binds to FPR2/ALX, so cross-reactivity between FPR2/ALX and CysLT1 ligands cannot be discarded. It is not well established whether the resolution properties reported for 15-epi-LXA4 are mediated through FPR2/ALX, or if other receptors such as CysLT1 may also be involved. Evaluation of specific FPR2/ALX ligands and CysLT1 antagonists in functional biochemical and cellular assays were performed to establish a role for both receptors in 15-epi-LXA₄-mediated signalling and function. In our study, a FPR2/ALX synthetic peptide (WKYMVm) and a small molecule FPR2/ALX agonist (compound 43) induced FPR2/ALX-mediated signalling, enhancing guanosine triphosphate-gamma (GTPγ) binding and decreasing cyclic adenosine monophosphate (cAMP) levels, whereas 15-epi-LXA₄ was inactive. Furthermore, 15-epi-LXA4 showed neither binding affinity nor signalling towards CysLT1. In neutrophils, 15-epi-LXA₄ showed a moderate reduction of interleukin (IL)-8-mediated neutrophil chemotaxis but no effect on neutrophil survival was observed. In addition, CysLT1 antagonists were inactive in FPR2/ALX signalling or neutrophil assays. In conclusion, 15-epi-LXA₄ is not a functional agonist or an antagonist of FPR2/ALX or CysLT1, shows no effect on IL-8-induced neutrophil survival and produces only moderate inhibition in IL-8-mediated neutrophil migration. Our data do not support an anti-inflammatory role of 15-epi-LXA₄- FPR2/ALX interaction in IL-8-induced neutrophil inflammation.

Microaerobic desulphurisation unit: a new biological system for the removal of H₂S from biogas

A new biotechnology for the removal of H2S from biogas was devised. The desulphurisation conditions present in microaerobic digesters were reproduced inside an external chamber called a microaerobic desulphurisation unit (MDU). A 10 L-unit was inoculated with 1L of digested sludge in order to treat the biogas produced in a pilot digester. During the 128 d of research under such conditions, the average removal efficiency was 94%. The MDU proved to be robust against fluctuations in biogas residence time (57-107 min), inlet H2S concentration (0.17-0.39% v/v), O2/H2S supplied ratio (17.3-1.4 v/v), and temperature (20-35°C). Microbiological analysis confirmed the presence of at least three genera of sulphide-oxidising bacteria. Approximately 60% of all the H2S oxidised was recovered from the bottom of the system in the form of large solid S(0) sheets with 98% w/w of purity. Therefore, this system could become a cost-effective alternative to the conventional biotechniques for biogas desulphurisation.

The potential of oxygen to improve the stability of anaerobic reactors during unbalanced conditions: results from a pilot-scale digester treating sewage sludge

A well-functioning pilot reactor treating sewage sludge at approximately 4.4 NL/m(3)/d of oxygen supply and 18d of hydraulic retention time (HRT) was subjected to a hydraulic overload to investigate whether oxygen benefits successful operation in stressful circumstances. Only a mild imbalance was caused, which was overcome without deterioration in the digestion performance. Volatile solids (VS) removal was 45% and 43% at 18 and 14 d of HRT, respectively. Biogas productivity remained around 546 NmL/gVS, but it was slightly higher during the period of imbalance. Thereafter, similar performances were achieved. Under anaerobic conditions, VS removal and biogas productivity were respectively 41% and 525 NmL/gVS, hydrogen partial pressure rose, and acetic acid formation became less favourable. Oxygen seemed to form a more stable digestion system, which meant increased ability to deal successfully with overloads. Additionally, it improved the biogas quality; methane concentration was negligibly lower, while hydrogen sulphide and oxygen remained around 0.02 and 0.03%v/v, respectively.