Detection of anti-HEV antibodies but no molecular positivity in dogs in the Campania region, southern Italy

Paslahepevirus balayani genotypes 3 and 4 (HEV-3 and 4) have zoonotic potential and can be transmitted to humans and animals through the consumption of contaminated raw or undercooked meat. Although it has been demonstrated that dogs are susceptible to the infection and produce specific antibodies, the epidemiological role of this species is not yet well defined. This study aimed to evaluate the circulation of HEV at the serological and molecular level in the dog population of the Campania region, southern Italy. A total of 231 dogs were sampled, divided according to several variables (sex, age, origin, lifestyle, location, size, and breed), and tested for the presence of HEV antibodies using a commercial multi-species ELISA. A total of 197 blood samples and 170 stool samples were tested with two specific PCRs in order to detect viral RNA. A total of 19 out samples of 231 were seropositive, obtaining an exposure (8.2%) similar to that observed in other European countries. The univariate and multivariate analysis revealed a wide exposure to stray dogs and animals from the province of Salerno. All samples tested with molecular methods were negative. Defining the role of domestic carnivores continues to be a "one health" challenge, although it appears that they do not eliminate the virus and therefore do not pose a danger to humans. In the absence of other evidence, it is advisable to continue to carry out surveillance also for domestic animals, which, due to ethological characteristics or their position in the food chain, could be predisposed to being exposed to HEV.

Wearable Ring-Shaped Biomedical Device for Physiological Monitoring through Finger-Based Acquisition of Electrocardiographic, Photoplethysmographic, and Galvanic Skin Response Signals: Design and Preliminary Measurements

Wearable health devices (WHDs) are rapidly gaining ground in the biomedical field due to their ability to monitor the individual physiological state in everyday life scenarios, while providing a comfortable wear experience. This study introduces a novel wearable biomedical device capable of synchronously acquiring electrocardiographic (ECG), photoplethysmographic (PPG), galvanic skin response (GSR) and motion signals. The device has been specifically designed to be worn on a finger, enabling the acquisition of all biosignals directly on the fingertips, offering the significant advantage of being very comfortable and easy to be employed by the users. The simultaneous acquisition of different biosignals allows the extraction of important physiological indices, such as heart rate (HR) and its variability (HRV), pulse arrival time (PAT), GSR level, blood oxygenation level (SpO2), and respiratory rate, as well as motion detection, enabling the assessment of physiological states, together with the detection of potential physical and mental stress conditions. Preliminary measurements have been conducted on healthy subjects using a measurement protocol consisting of resting states (i.e., SUPINE and SIT) alternated with physiological stress conditions (i.e., STAND and WALK). Statistical analyses have been carried out among the distributions of the physiological indices extracted in time, frequency, and information domains, evaluated under different physiological conditions. The results of our analyses demonstrate the capability of the device to detect changes between rest and stress conditions, thereby encouraging its use for assessing individuals' physiological state. Furthermore, the possibility of performing synchronous acquisitions of PPG and ECG signals has allowed us to compare HRV and pulse rate variability (PRV) indices, so as to corroborate the reliability of PRV analysis under stationary physical conditions. Finally, the study confirms the already known limitations of wearable devices during physical activities, suggesting the use of algorithms for motion artifact correction.

Registry-derived stage (RD-Stage) for capturing cancer stage at diagnosis for endometrial cancer

BACKGROUND

Capture of cancer stage at diagnosis is important yet poorly reported by health services to population-based cancer registries. In this paper we describe current completeness of stage information for endometrial cancer available in Australian cancer registries; and develop and validate a set of rules to enable cancer registry medical coders to calculate stage using data available to them (registry-derived stage or 'RD-Stage').

METHODOLOGY

Rules for deriving RD-stage (Endometrial carcinoma) were developed using the American Joint Commission on Cancer (AJCC) TNM (tumour, nodes, metastasis) Staging System (8th Edition). An expert working group comprising cancer specialists responsible for delivering cancer care, epidemiologists and medical coders reviewed and endorsed the rules. Baseline completeness of data fields required to calculate RD-Stage, and calculation of the proportion of cases for whom an RD stage could be assigned, was assessed across each Australian jurisdiction. RD-Stage (Endometrial cancer) was calculated by Victorian Cancer Registry (VCR) medical coders and compared with clinical stage recorded by the patient's treating clinician and captured in the National Gynae-Oncology Registry (NGOR).

RESULTS

The necessary data completeness level for calculating RD-Stage (Endometrial carcinoma) across various Australian jurisdictions varied from 0 to 89%. Three jurisdictions captured degree of spread of cancer, rendering RD-Stage unable to be calculated. RD-Stage (Endometrial carcinoma) could not be derived for 64/485 (13%) cases and was not captured for 44/485 (9%) cases in NGOR. At stage category level (I, II, III, IV), there was concordance between RD-Stage and NGOR captured stage in 393/410 (96%) of cases (95.8%, Kendall's coefficient = 0.95).

CONCLUSION

A lack of consistency in data captured by, and data sources reporting to, population-based cancer registries meant that it was not possible to provide national endometrial carcinoma stage data at diagnosis. In a sample of Victorian cases, where surgical pathology was available, there was very good concordance between RD-Stage (Endometrial carcinoma) and clinician-recorded stage data available from NGOR. RD-Stage offers promise in capturing endometrial cancer stage at diagnosis for population epidemiological purposes when it is not provided by health services, but requires more extensive validation.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

Correlation between physical activity, nutritional intake, and osteoporosis in postmenopausal women: a preliminary evaluation

OBJECTIVE

Osteoporosis is a chronic metabolic syndrome associated with debilitating consequences that represents one of the major non-communicable diseases and the most common bone illness that affects both men and women. This observational study evaluates the amount of physical activity and the nutritional intake in a group of postmenopausal women who have a sedentary job.

PATIENTS AND METHODS

All subjects underwent a medical evaluation, a body impedance analysis to evaluate body composition (fat mass, fat-free mass, and body cell mass), and a dual-energy X-ray absorptiometry to analyze bone mineral density. Additionally, a 3-day food record questionnaire and the International Physical Activity Questionnaire were administered respectively to evaluate patients' foods and beverages assumptions and the participants' Physical Activity levels.

RESULTS

The study showed that most of the patients had a moderate activity level and inadequate calcium and vitamin D assumption compared to guidelines.

CONCLUSIONS

The onset of osteoporosis seemed to be reduced at higher levels of leisure time, domestic, and transport activities, even in subjects who have a sedentary job and insufficient assumption of micronutrients.

Wearable Multisensor Ring-Shaped Probe for Assessing Stress and Blood Oxygenation: Design and Preliminary Measurements

The increasing interest in innovative solutions for health and physiological monitoring has recently fostered the development of smaller biomedical devices. These devices are capable of recording an increasingly large number of biosignals simultaneously, while maximizing the user's comfort. In this study, we have designed and realized a novel wearable multisensor ring-shaped probe that enables synchronous, real-time acquisition of photoplethysmographic (PPG) and galvanic skin response (GSR) signals. The device integrates both the PPG and GSR sensors onto a single probe that can be easily placed on the finger, thereby minimizing the device footprint and overall size. The system enables the extraction of various physiological indices, including heart rate (HR) and its variability, oxygen saturation (SpO₂), and GSR levels, as well as their dynamic changes over time, to facilitate the detection of different physiological states, e.g., rest and stress. After a preliminary SpO₂ calibration procedure, measurements have been carried out in laboratory on healthy subjects to demonstrate the feasibility of using our system to detect rapid changes in HR, skin conductance, and SpO₂ across various physiological conditions (i.e., rest, sudden stress-like situation and breath holding). The early findings encourage the use of the device in daily-life conditions for real-time monitoring of different physiological states.

The possible role of physical activity in the modulation of gut microbiota in chronic kidney disease and its impact on cardiovascular risk: a narrative review

Chronic degenerative non-communicable diseases (CDNCDs), in particular chronic kidney disease, induce gut microbiota (GM) dysbiosis, which, in turn, worsens the progression of CDNCDs and patients' quality of life. We analyzed literature studies to discuss the possible positive and beneficial impact of physical activity on GM composition and CV risk in CKD patients. Regular physical activity seems to be able to positively modulate the GM, reducing the systemic inflammation and consequently the production of uremic gut-derived toxins, which are directly correlated with the increase of cardiovascular risk. In particular, the accumulation of indoxyl sulphate (IS) seems to be able to induce vascular calcifications, vascular stiffness and cardiac calcifications, while p-Cresyl sulphate (p-CS) seems to be able to exert a cardiotoxic action through metabolic pathways, capable of inducing oxidative stress. In addition, trimethylamine N-oxide (TMAO) can alter lipid metabolism, inducing the production of foam cells and causing an accelerated atherosclerosis process. In this context, a regular physical activity program seems to represent an adjuvant non-pharmacological approach to the clinical management of CKD patients.

Active breaks: a strategy to counteract sedentary behaviors for Health Promoting Schools. A discussion on their implementation in Italy

Abstract

School Active Breaks are short bouts of physical activity (5-15 minutes) conducted by appropriately trained teachers and delivered during or between curricular lessons. They are a good strategy to counteract sedentary behaviors, and a growing body of evidence shows that they can represent also a tool to promote and improve health, school wellbeing and academic achievements. On 19 February 2022, the Working Group on Movement Sciences for Health of the Italian Society of Hygiene, Preventive Medicine and Public Health organized an Awareness Day on the effectiveness, usefulness and feasibility of School Active Breaks, opened to teachers, educators, school leaders, pediatricians, personnel from Departments of Prevention and Public Health and Health Policy-makers. During the event, the testimonies about the experiences already carried out in Italy showed that School Active Breaks are an effective intervention that each school can easily include in its educational offer and apply in any context.

Detection of carbapenemase- and ESBL-producing Klebsiella pneumoniae from bovine bulk milk and comparison with clinical human isolates in Italy

Klebsiella pneumoniae is the most common Klebsiella species infecting animals and is one of the causing agents of mastitis in cows. The rise of antimicrobial resistance in K. pneumoniae, particularly in strains producing extended-spectrum β-lactamases (ESBLs) and/or carbapenemases, is of concern worldwide. Recently (Regulation UE No 2022/1255), carbapenems and cephalosporins in combination with β-lactamase inhibitors have been reserved only to human treatments in the European Union. The aim of this study was to investigate the role of cattle as carrier of human pathogenic carbapenem-resistant (CR) and ESBL-producing K. pneumoniae. On this purpose, a study involving 150 dairy farms in Parma province (Northern Italy) and 14 non replicate K. pneumoniae isolates from patients admitted at Parma University-Hospital was planned. Four multidrug resistant (MDR) K. pneumoniae strains were detected from 258 milk filters collected between 2019 and 2021. One carbapenemase KPC-3-positive K. pneumoniae ST307 (0.4 %; 95 % CI - 0.07 - 2.2) was detected in milk filters. The isolate also harboured OXA-9, CTX-M-15 and SHV-106 determinants, together with genes conferring resistance to aminoglycosides (aac(3')-IIa, aph (3″)-Ib, aph (6)-Id), fluoroquinolones (oqxA, oqxB, qnrB1), phosphonic acids (fosA6), sulphonamides (sul2), tetracyclines (tet(A)6) and trimethoprim (dfrA14). One KPC-3-producing K. pneumoniae ST307 was identified also among the human isolates, thus suggesting a possible circulation of pathogens out of the clinical settings. The remaining three bovine isolates were MDR ESBL-producing K. pneumoniae characterized by different genomic profiles: CTX-M-15, TEM-1B and SHV-187 genes (ST513); CTX-M-15 and SHV-145 (ST307); SHV-187 and DHA-1 (ST307). Occurrence of ESBL-producing K. pneumoniae in milk filters was 1.2 % (95 % CI 0.4-3.4). All the isolates showed resistance to aminoglycosides, 3rd-generation cephalosporins, and fluoroquinolones. Among the human isolates, two multidrug resistant ESBL-producing K. pneumoniae ST307 were found, thus confirming the circulation of this high-risk lineage between humans and cattle. Our findings suggest that food-producing animals can carry human pathogenic microorganisms harboring resistance genes against carbapenems and 3rd-generation cephalosporins, even if not treated with such antimicrobials. Moreover, on the MDR K. pneumoniae farms, the antimicrobial use was much higher than the Italian median value, thus highlighting the importance of a more prudent use of antibiotics in animal productions.

Neuromuscular and cardiac adverse events associated with immune checkpoint inhibitors: pooled analysis of individual cases from multiple institutions and literature

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the management of multiple tumors, due to improved efficacy, quality of life, and safety. While most immune-related adverse events (irAEs) are mild and easily managed, in rare cases such events may be life-threatening, especially those affecting the neuromuscular and cardiac system. The management of neuromuscular/cardiac irAEs is not clear due to the lack of consistent data. Therefore, we carried out a pooled analysis of collected cases from selected Italian centers and individual data from published case reports and case series, in order to improve our understanding of these irAEs.

PATIENTS AND METHODS

We collected retrospective data from patients treated in six Italian centers with ICIs (programmed cell death protein 1 or programmed death-ligand 1 and/or cytotoxic T-lymphocyte antigen 4 inhibitor) for any solid tumor who experienced neuromuscular and/or cardiovascular toxicity. Then, we carried out a search of case reports and series of neuromuscular/cardiac irAEs from ICIs with any solid tumor.

RESULTS

This analysis includes cases from Italian institutions (n = 18) and the case reports identified in our systematic literature search (n = 120), for a total of 138 patients. Among these patients, 50 (36.2%) had complete resolution of their neuromuscular/cardiac irAEs, in 21 (15.2%) cases there was a clinical improvement with mild sequelae, and 53 (38.4%) patients died as a result of the irAEs. Factors significantly associated with worse outcomes were early irAE onset, within the first two cycles of ICI (Fisher P < 0.0001), clinical manifestation of both myositis and myocarditis when compared with patients who developed only myositis or myocarditis (chi-square P = 0.0045), and the development of arrhythmia (Fisher P = 0.0070).

CONCLUSIONS

To the best of our knowledge, this is the largest collection of individual cases of immune-related myocarditis/myositis. Early irAE onset, concurrent development of myositis and myocarditis, as well as occurrence of arrhythmias are associated with worse outcomes and should encourage an aggressive immunomodulatory treatment.

Adaptive scheduling of acceleration and gyroscope for motion artifact cancelation in photoplethysmography

BACKGROUND AND OBJECTIVE

Recently, various algorithms have been introduced using wrist-worn photoplethysmography (PPG) to provide high accuracy of instantaneous heart rate (HR) estimation, including during high-intensity exercise. Most studies focus on using acceleration and/or gyroscope signals for the motion artifact (MA) reference, which attenuates or cancels out noise from the MA-corrupted PPG signals. We aim to open and pave the path to find an appropriate MA reference selection for MA cancelation in PPG.

METHODS

We investigated how the acceleration and gyroscope reference signals correlate with the MAs of the distorted PPG signals and derived both mathematically and experimentally an adaptive MA reference selection approach. We applied our algorithm to five state-of-the-art (SOTA) methods for the performance evaluation. In addition, we compared the four MA reference selection approaches, i.e. with acceleration signal only, with gyroscope signal only, with both signals, and using our proposed adaptive selection.

RESULTS

When applied to 47 PPG recordings acquired during intensive physical exercise from two different datasets, our proposed adaptive MA reference selection method provided higher accuracy than the other MA selection approaches for all five SOTA methods.

CONCLUSION

Our proposed adaptive MA reference selection approach can be used in other MA cancelation methods and reduces the HR estimation error.

SIGNIFICANCE

We believe that this study helps researchers to address acceleration and gyroscope signals as accurate MA references, which eventually improves the overall performance for estimating HRs through the various algorithms developed by research groups.

Clinical efficacy of sequential treatments in KRASG12C-mutant metastatic colorectal cancer: findings from a real-life multicenter Italian study (CRC-KR GOIM)

Background

The presence of KRASG12C mutation in metastatic colorectal cancer (mCRC) correlates with poor outcome. Although different selective inhibitors are under clinical development, the optimal treatment remains uncertain. Thus, we conducted a retrospective analysis in a large cohort of patients with KRASG12C mCRC treated in 12 Italian oncology units.

Patients and methods

Patients with unresectable mCRC harboring KRASG12C mutation receiving a first-line chemotherapy doublet or triplet between 2011 and 2021 were included in the study. Evaluation of overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) analysis was carried out.

Results

A total of 256/6952 (3.7%) patients with mCRC displayed KRASG12C mutation; of these, 111 met the inclusion criteria. The ORR of first-line therapy was 38.7% (43/111). Median PFS (mPFS) was 9 months [95% confidence interval (CI) 7.5-10.5 months]. After progression, only 62% and 36% of the patients are fit to receive second or third lines of treatment, with limited clinical benefit. Median OS (mOS) was 21 months (95% CI 17.4-24.6 months). In patients receiving first-line triplet chemotherapy, ORR was 56.3% (9/16), mPFS was 13 months (95% CI 10.3-15.7 months) and mOS was 32 months (95% CI 7.7-56.3 months). For irinotecan-based doublets, ORR was 34.5 (10/29), mPFS was 9 months (95% CI 6.4-11.6 months) and mOS was 22 months (95% CI 16.0-28.0 months). With oxaliplatin-based doublets ORR was 36.4% (24/62), mPFS was 7 months (95% CI 4.6-9.4 months) and mOS was 18 months (95% CI, 13.6-22.4 months).

Conclusion

Patients with KRASG12C-mutant mCRC had a disappointing response to standard treatments. Within the limitations of a retrospective study, these results suggest that first-line chemotherapy intensification with FOLFOXIRI is a valid option in fit patients.

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KRASG12C mutation is rare and occurs in 3.7% of the study population.

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The presence of KRASG12C mutation is correlated with an aggressive disease, with reduced response to chemotherapy.

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Only 62% and 36% of patients with KRASG12C-mutant mCRC are fit to receive second or third lines of treatment, respectively.

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The use of chemotherapy triplets is associated with improved outcomes compared with chemotherapy doublets.

Encorafenib plus cetuximab with or without binimetinib in patients with BRAF V600E-mutated metastatic colorectal cancer: real-life data from an Italian multicenter experience

Background

Encorafenib plus cetuximab with or without binimetinib showed increased objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) compared with chemotherapy plus anti-EGFR in previously treated patients with BRAF V600E-mutated (mut) metastatic colorectal cancer (mCRC). Although no formal comparison was planned, addition of binimetinib to encorafenib plus cetuximab did not provide significant efficacy advantage.

Patients and methods

This real-life study was aimed at evaluating safety, activity, and efficacy of encorafenib plus cetuximab with or without binimetinib in patients with BRAF V600E-mut mCRC treated at 21 Italian centers within a nominal use program launched in May 2019.

Results

Out of 133 patients included, 97 (73%) received encorafenib plus cetuximab (targeted doublet) and 36 (27%) the same therapy plus binimetinib (targeted triplet). Most patients had Eastern Cooperative Group Performance Status (ECOG-PS) of 0 or 1 (86%), right-sided primary tumor (69%), and synchronous disease (66%). Twenty (15%) tumors were DNA mismatch repair deficiency (dMMR)/microsatellite instability (MSI)-high. As many as 44 (34%) patients had received two or more prior lines of therapy, 122 (92%) were previously exposed to oxaliplatin, and 109 (82%) to anti-vascular endothelial growth factor (anti-VEGF). Most frequent adverse events were asthenia (62%) and anti-EGFR-related skin rash (52%). Any grade nausea (P = 0.03), vomiting (P = 0.04), and diarrhea (P = 0.07) were more frequent with the triplet therapy, while melanocytic nevi were less common (P = 0.06). Overall, ORR and disease control rate (DCR) were 23% and 69%, respectively, with numerically higher rates in the triplet group (ORR 31% versus 17%, P = 0.12; DCR 78% versus 65%, P = 0.23). Median PFS and OS were 4.5 and 7.2 months, respectively. Worse ECOG-PS, peritoneal metastases, and more than one prior treatment were independent poor prognostic factors for PFS and OS. Clonality of BRAF mutation measured as adjusted mutant allele fraction in tumor tissue was not associated with clinical outcome.

Conclusions

Our real-life data are consistent with those from the BEACON trial in terms of safety, activity, and efficacy. Patients in good general condition and not heavily pretreated are those more likely to derive benefit from the targeted treatment.

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Encorafenib plus cetuximab ± binimetinib is safe and effective for BRAF V600E mut mCRC even in the real-world setting.

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Median OS is slightly shorter than in the BEACON trial, probably due to less selected patients in real life.

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Patients deriving more benefit from targeted therapy are likely those in good general conditions and not heavily pretreated.

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BRAF adjusted MAF is worth further investigation to better characterize the genomic heterogeneity of BRAF V600E mut mCRC.

Indocyanine green fluorescence angiography versus standard intraoperative methods for prevention of anastomotic leak in colorectal surgery: meta-analysis

BACKGROUND

Assessment of anastomotic blood perfusion with intraoperative indocyanine green fluorescence angiography (ICG-FA) may be effective in preventing anastomotic leak compared with standard intraoperative methods in colorectal surgery.

METHODS

MEDLINE, PubMed, Cochrane Central Register of Controlled Trials and the Cochrane Library were searched for RCTs and observational studies on intraoperative ICG-FA to May 2020. Odds ratios (ORs), risk differences and mean differences (MDs) were calculated with 95 per cent c.i. based on intention-to-treat analysis. The number needed to treat for an additional beneficial outcome was also estimated.

RESULTS

Twenty-five comparative studies included a total of 7735 patients. The use of intraoperative ICG fluorescence angiography was linked with a significant reduction in all grades anastomotic leak (OR 0.39 (95 per cent c.i. 0.31 to 0.49), P < 0.001; number needed to treat for an additional beneficial outcome (NNTB) 23) and length of hospital stay (MD -0.72 (95 per cent c.i. -1.22 to -0.21) days, P = 0.006). A significantly lower incidence of grade A (OR 0.33 (0.18 to 0.60), P < 0.001), grade B (OR 0.58 (0.35 to 0.97), P = 0.04) and grade C (OR 0.59 (0.38 to 0.92), P = 0.02) anastomotic leak was demonstrated in favour of ICG-FA. For low or ultra-low rectal resection, the odds of developing anastomotic leakage was 0.32 (0.23 to 0.45) (P < 0.001; NNTB 14). There were no differences in duration of surgery, and no adverse events related to ICG fluorescent injection.

CONCLUSION

The use of ICG-FA instead of standard intraoperative methods to assess anastomosis blood perfusion in colorectal surgery leads to a significant reduction in anastomotic leakage and in the need for surgical reintervention for anastomotic leak, especially in patients with low or ultra-low rectal resections.

P–048 Effects of bisphenol S and bisphenol F on human spermatozoa: an in vitro study

Study question

Are plasticizers bisphenol S (BPS) and bisphenol F (BPF) safer alternatives to bisphenol A (BPA) for human sperm function?

Summary answer

Unlike BPA, the analogues BPS and BPF do not significantly affect human sperm mitochondrial functions, motility and viability

What is known already

The widespread distribution of BPA, along with its reputation to be an endocrine disruptor has generated concerns about possible adverse effects for human health, thus prompting the European Food Safety Authority and the Food and Drug Administration to ban the use of this chemical in many plastic products. Following such restrictions, several substitutes have been developed, with BPS and BPF representing the main replacements to BPA. While it has been demonstrated that BPA promotes oxidative damages in spermatozoa from different species, including human, the possible effects exerted by BPS and BPF on human sperm, have not yet been investigated.

Study design, size, duration

We explored the effect of 4 h in vitro exposure to scalar concentrations of BPS and BPF (from 10 to 400 μM), and to 400 μM BPA on sperm motility, viability, mitochondrial membrane potential (Δm) and mitochondrial generation of reactive oxygen species (ROS). In a set of experiments, the effect of a combination of both BPF (400 μM) and BPS (400 μM) on ΔΨm and mitochondrial ROS generation was also assessed.

Participants/materials, setting, methods

Sperm Δm was analyzed by flow cytometry with the fluorescent lipophilic cationic dye JC–1. Flow cytometric assessment of mitochondrial generation of ROS was carried out using the lipid soluble cation MitoSOX red (MSR). Sperm motility and viability were evaluated by Computer-Aided Semen Analysis (CASA) and eosin assay, respectively.

Main results and the role of chance

The exposure to scalar concentration of BPS did not significantly affect sperm motility and viability with respect to untreated controls. A lower, albeit not significant, sperm motility was registered in samples exposed to the highest concentrations of BPF (300 μM and 400 μM). As expected, 400 μM BPA produced a complete sperm immobilization along with a dramatically loss in sperm viability. No significant differences were observed in sperm Δm and ROS generation after exposure to scalar concentration of BPS compared to untreated controls and the trend towards lower Δm and higher mitochondrial ROS generation at the highest concentrations of BPF did not reach statistical significance. On the contrary, after 4 h exposure to 400 μM BPA a significant lower Δm and higher mitochondrial ROS generation were observed. Finally, the exposure to a combination of BPF and BPS at high concentrations (400 μM) did not significantly affect sperm Δm, or mitochondrial ROS generation, when compared to 400 μM BPA, used as positive control. Limitations, reasons for caution: The present study only evaluated BPS and BPF effects, but in daily-life people are exposed to several plasticizers containing different bisphenols at different concentrations. Therefore, adverse effects of synergic exposure to BPA analogues other than BPS and BPF, alone or in combination with BPA, cannot be ruled out.

Wider implications of the findings: The analogues BPS and BPF, alone or in combination, appeared to be safer alternatives to BPA on sperm biology as they exert a neutral effect on sperm motility, viability, and mitochondrial functions even at high concentrations. These results could be useful to identify more secure plasticizer components.

Trial registration number

Not applicable

Evidence of new sequence types of methicillin-resistant Staphylococcus pseudintermedius in Italy

Staphylococcus pseudintermedius (SP) and methicillin-resistant SP (MRSP) is one of the most important veterinary pathogens in the dog. Herein, from a total of 126 S. pseudintermediusstrains, 23 MRSP (18%) were identified. Multi-Locus Sequence Typing (MLST) revealed that most of MRSP strains belonged to ST71 (26%), which have been already reported in Italy and other countries. Interestingly, nine new sequence types (39%), from 1053 up to 1061, were described for the first time. Moreover, the isolated MRSP strains showed relevant antibiotic resistance profiles. This report highlights the circulation of new sequence types of MRSP in Italy and underlines the need of a global epidemiological surveillance to limit the increasing spread of multidrug-resistant MRSPstrains worldwide, since they may represent a considerable concern for dog's health.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Rapid screening for SARS-CoV-2 variants of concern in clinical and environmental samples using nested RT-PCR assays targeting key mutations of the spike protein

New SARS-CoV-2 mutations are constantly emerging, raising concerns of increased transmissibility, virulence or escape from host immune response. We describe a nested RT-PCR assay (~1500 bps) to detect multiple nucleotide changes resulting in key spike protein mutations distinctive of the major known circulating SARS-CoV-2 variants, including the three Variants of Concern (VOCs) 20I/501Y.V1 (United Kingdom), 20H/501Y.V2 (South Africa), and 20 J/501Y.V3 (Brazil), as well as the 20E.EU1 variant (Spain), the CAL.20C recently identified in California, and the mink-associated variant (GR, lineage B.1.1.298). Prior to application to field samples, the discriminatory potential of this PCR assay was explored using GISAID and Nextclade. To extend variant detection to challenging matrices such as sewage, where the amplification of long fragments is problematic, two short nested RT-PCR assays (~300 bps) were also designed, targeting portions of the region spanned by the long nested assay. The three newly-designed assays were then tested on field samples, including 31 clinical samples (7 fully-sequenced swab samples, and 24 uncharacterized ones) and 34 urban wastewater samples, some of which collected in areas where circulation of VOCs had been reported. The long assay successfully amplified 29 of the 31 swabs (93%), allowing the correct identification of variants 20I/501Y.V1 and 20E.EU1 present in the panel of previously characterized samples. The Spanish variant was detected in 14/24 of the uncharacterized samples as well. The sequences obtained using the short assays were consistent with those obtained with the long assay. Mutations characteristic of VOCs (UK and Brazilian variant) and of other variant (Spanish) were detected in sewage samples. To our knowledge, this is the first evidence of the presence of sequences harboring key mutations of 20I/501Y.V1 and 20 J/501Y.V3 in urban wastewaters, highlighting the potential contribution of wastewater surveillance to explore SARS-CoV-2 diversity. The developed nested RT-PCR assays can be used as an initial rapid screening test to select clinical samples containing mutations of interest. This can speed up diagnosis and optimize resources since it allows full genome sequencing to be done only on clinically relevant specimens. The assays can be also employed for a rapid and cost-effective detection of VOCs or other variants in sewage for the purposes of wastewater-based epidemiology. The approach proposed here can be used to better understand SARS-CoV-2 variant diversity, geographic distribution and impact worldwide.

What factors have impact on glucocorticoid replacement in adrenal insufficiency: a real-life study

PURPOSE

The impact of patient's characteristics on glucocorticoid (GC) replacement therapy in adrenal insufficiency (AI) is poorly evaluated. Aims of this study were to assess the influence of sex and body weight on GC dosing and to describe the choice of GC in AI of different etiologies.

METHODS

We retrospectively evaluated hydrocortisone (HC) equivalent total daily dose (HC-TDD) and per-kg-daily dose (HC-KDD) in 203 patients (104 primary AI [pAI], 99 secondary AI [sAI]) followed up for ≥ 12 months. They were treated with HC, modified-release HC (MRHC) or cortisone acetate (CA) and fludrocortisone acetate (FCA) in pAI.

RESULTS

At baseline, CA was preferred both in pAI and sAI; at last visit, MRHC was most used in pAI (49%) and CA in sAI (73.7%). Comparing the last visit with baseline, in pAI, HC-TDD and HC-KDD were significantly lower (p = 0.04 and p = 0.006, respectively), while FCA doses increased during follow-up (p = 0.02). The reduction of HC-TDD and HC-KDD was particularly relevant for pAI women (p = 0.04 and p = 0.002, respectively). In sAI patients, no change of HC-KDD and HC-TDD was observed, and we found a correlation between weight and HC-TDD in males (r 0.35, p = 0.02).

CONCLUSIONS

Our real-life study demonstrated the influence of etiology of AI on the type of GC used, a weight-based tailoring in sAI, a likely overdosage of GC treatment in pAI women at the start of treatment and the possibility to successfully increase FCA avoiding GC over-treatment. These observations could inform the usual clinical practice.

Relationship of Vitamin D status with testosterone levels: a systematic review and meta-analysis

PURPOSE

Despite a biological plausibility of a direct link between low vitamin D and androgen deficiency, the association remains inconclusive in epidemiological studies. Therefore, this systematic review and meta-analysis of case-control studies aim to assess whether and in what populations such an association can be demonstrated.

METHODS

A systematic search was performed in PubMed, EMBASE, Cochrane Library, Web of science, Science Direct, and CINAHL. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) in total testosterone (TT) levels between men with 25-hydroxyvitamin D (25(OH)D) <20 and ≥20 ng/mL were combined using random-effects models. Funnel plot and trim-and-fill analysis were used to assess publication bias. Heterogeneity source was explored by a sub-group analysis according to health-related characteristics of the study populations.

RESULTS

Eighteen included studies collectively gave information on 9892 men with vitamin D deficiency and 10,675 controls. The pooled SMD revealed a slight, albeit just significant, positive association between 25(OH)D and TT (pooled SMD: -0.23, 95% CI: -0.45 to -0.01; P = 0.04) with a large between-study heterogeneity (I² = 98%, P_{for heterogeneity} < 0.00001). At the sub-group analysis, a significant positive association, along with noticeable decrease in heterogeneity, could only be demonstrated in studies of patients with frailty states (pooled SMD: -0.19; 95% CI: -0.27, -0.10,  P < 0.0001; I² = 51%, P_{for heterogeneity} = 0.06). A sensitivity analysis revealed a high stability of the result and the trim-and-fill adjustment for publication bias did not affect pooled estimate.

CONCLUSIONS

Both hypovitaminosis D and androgen deficiency should be regarded as markers of a poor health status, sharing common underlying aetiologies and risk factors.

Characterization of passive dosimeters in proton pencil beam scanning - A EURADOS intercomparison for mailed dosimetry audits in proton therapy centres

The lack of mailed dosimetry audits of proton therapy centres in Europe has encouraged researchers of EURADOS Working Group 9 (WG9) to compare response of several existing passive detector systems in therapeutic pencil beam scanning. Alanine Electron Paramagnetic Resonance dosimetry systems from 3 different institutes (ISS, Italy; UH, Belgium and IFJ PAN, Poland), ^natLiF:Mg, Ti (MTS-N) and ^natLiF:Mg, Cu, P (MCP-N) thermoluminescent dosimeters (TLDs), GD-352M radiophotoluminescent glass dosimeters (RPLGDs) and Al₂O₃:C optically stimulated dosimeters (OSLDs) were evaluate. Dosimeter repeatability, batch reproducibility and response in therapeutic Pencil Beam Scanning were verified for implementation as mail auditing system. Alanine detectors demonstrated the lowest linear energy transfer (LET) dependence with an agreement between measured and treatment planning system (TPS) dose below 1%. The OSLDs measured on average a 6.3% lower dose compared to TPS calculation, with no significant difference between varying modulations and ranges. Both GD-352M and MCP-N measured a lower dose than the TPS and luminescent response was dependent on the LET of the therapeutic proton beam. Thermoluminescent response of MTS-N was also found to be dependent on the LET and a higher dose than TPS was measured with the most pronounced increase of 11%. As alanine detectors are characterized by the lowest energy dependence for different parameters of therapeutic pencil beam scanning they are suitable candidates for mail auditing in proton therapy. The response of luminescence detector systems have shown promises even though more careful calibration and corrections are needed for its implementation as part of a mailed dosimetry audit system.

Clinical and seminal parameters associated with testicular microlithiasis and its severity in males from infertile couples

STUDY QUESTION

Is there an association of testicular microlithiasis (TM) and its severity with testicular dysfunction in men from infertile couples?

SUMMARY ANSWER

The presence of ≥5 testis microcalcifications per sonogram at the scrotal ultrasonography (US) of infertile males was associated with a more severe testicular dysfunction as compared to males with limited, or without, TM.

WHAT IS KNOWN ALREADY

TM, representing an incidental finding in the scrotal US, is associated with male infertility and a higher risk for testicular cancer as compared to that in infertile males without TM. Still, there are unresolved questions on the relation between TM severity and testicular dysfunction in infertile men, as well as on the identification of risk factors for TM.

STUDY DESIGN, SIZE, DURATION

This study was an observational, retrospective, case-control investigation involving males who underwent clinical evaluation, measurement of reproductive hormones, seminal analysis and scrotal US as part of diagnostic work-up for couple infertility at an andrology clinic, between January 2004 and December 2018. One hundred patients, out of the 2112 scored men, were found to have TM during the US evaluation. One hundred male partners from 100 infertile couples without TM, comprising the control group, were selected through a matched analysis by age and date of evaluation to reduce the confounding effect of both age and technique variability all along the long period of observation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

TM was defined as limited TM (LTM) or classical TM (CTM), when the maximum number of hyperecogenic spots per sonogram was &lt;5 or ≥5, respectively. CTM, LTM and control groups were compared for clinical variables, serum levels of FSH, LH, and total testosterone, as well for semen parameters and scrotal US features.

MAIN RESULTS AND THE ROLE OF CHANCE

After the exclusion of cases with testicular nodules to eliminate the possible confounding effect of testis cancer on testicular dysfunction, cases with CTM showed a lower mean testis volume (P = 0.03) and a lower sperm concentration (P = 0.03) as compared to the other two groups. A higher FSH level was observed in the CTM group compared to the LTM group (P = 0.02) and in controls (P = 0.009). The multiple logistic regression analysis showed that only a smaller testicle volume exhibited an independent significant association with a higher odds of detecting CTM (odds ratio = 0.84, 95% CI: 0.75–0.94; P = 0.02). No significant differences were observed between groups in the prevalence of risk factors for testicular cancer, or in the prevalence of conditions associated with TM.

LIMITATIONS, REASONS FOR CAUTION

The retrospective design of the study did not allow conclusions to be drawn about the possible underlying links in the associations of TM with defective spermatogenesis.

WIDER IMPLICATIONS OF THE FINDINGS

Males from infertile couples who exhibit a reduced testicular volume should undergo scrotal US, independent of sperm parameters, to exclude CTM and, eventually, testis cancer, although the association of CTM and current or future testis cancer risk is not yet clear. Evidence is provided here demonstrating that the presence of LTM has no clinical relevance in males from infertile couples.

STUDY FUNDING/COMPETING INTEREST(S)

Investigation was funded by Ministero dell’Università e della Ricerca, PRIN 2018, Italy. The authors have not declared any competing interests.

TRIAL REGISTRATION NUMBER

N/A

Frailty of the elderly in orthopaedic surgery and body composition changes: the musculoskeletal crosstalk through irisin

In recent years, scientific interest has been developed towards irisin, a novel molecule of the family of myokines, which is directly involved in body mass composition balance, chronic diseases susceptibility and physiologic resilience to stressful events, including surgery. In the context of musculoskeletal disease, the role of this molecule has been associated to the balance of lean and fatty mass, and the production of irisin is subordinated to a healthy lifestyle and exercise. The mechanism of action of irisin on tissues is complex, and several studies described the molecular pathways in animal model and human subjects. In particular, in adipose cells, the key-role of irisin is to stimulate the differentiation of white adipose tissue to brown adipose tissue, through the action on the uncoupling protein 1. Furthermore, in the bony tissue, irisin stimulates osteogenesis through expression of Sost and Opn genes. These features make irisin a suitable molecule to use as a biomarker of the overall musculoskeletal health of the elderly, before undergoing orthopaedic surgery. Further research on this topic should be carried out to highlight the possible clinical role and predictive value of irisin in a multidisciplinary approach to the elderly before musculoskeletal surgery.

Food-Borne Bacteria Associated with Seafoods: A Brief Review

Consumption of contaminated seafoods is a major cause of death and hospitalization particularly in poor and developing countries. As with other food types, seafoods are also not free of food-borne pathogens and several risk factors are associated with its consumption. Regarding seafoods, there are regulatory hygienic alerts in importing countries. This paper briefly reviews the occurrence of seafood-borne diseases and describes the most important bacterial causes of these infections. Also, major bacterial threats, the route of infection, and food safety concerns associated with seafoods consumption are explained. Several bacterial pathogens, like Vibrio spp., Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Clostridium botulinum, Shigella spp., and Aeromonas spp. are considered as microbiological hazards for seafoods. These bacteria can contaminate seafood products anytime from farm to table. Some effective methods should be adopted for control and prevention of bacterial hazards in fish industry. Maintaining the microbiological water quality of domestic capture, post-harvest care, proper hygiene, etc. can minimize the bacterial hazards. Food-borne intoxications can be controlled by the proper refrigeration of seafoods and the continuous monitoring of the chill chain during the entire production process right up to consumption. Other ways to prevent food-borne outbreaks due to consumptions of seafoods are training of the consumers about correct handling of food, proper preparation, and storage of seafoods.

Comparison of virtual reality rehabilitation and conventional rehabilitation in Parkinson's disease: a randomised controlled trial

OBJECTIVE

To compare a 6-week virtual reality (VR) rehabilitation programme with a conventional rehabilitation programme in patients with Parkinson's disease.

DESIGN

Prospective, single-blinded, randomised controlled trial.

SETTING

Outpatients.

PARTICIPANTS

Fifty-one patients with Parkinson's disease were assigned at random to a VR rehabilitation programme or a conventional rehabilitation programme.

INTERVENTIONS

Both programmes ran for 6 consecutive weeks, with a 40-minute session three times per week.

MAIN OUTCOME MEASURES

The Balance Berg Scale (BBS) was used to measure balance. Secondary outcome measures were: Dynamic Gait Index (DGI) to evaluate ability to adapt gait to complex walking tasks; Disabilities of the Arm, Shoulder and Hand (DASH) scale to measure performance of the upper limb; and Short Form 36 (SF-36) to evaluate quality of life.

RESULTS

The VR rehabilitation programme led to an increase in BBS score {45.6 [standard deviation (SD) 7.9] vs 49.2 (SD 8.1), mean difference 3.6, 95% confidence interval (CI) 1.3 to 5.9; P=0.003}, DGI score [18.7 (SD 4.7) vs 20.2 (SD 4.2), mean difference 1.6, 95% CI 0.6 to 2.5; P=0.003] and SF-36 mental composite score [37.7 (SD 11.4) vs 43.5 (SD 9.2), mean difference 5.8, 95% CI 0.4 to 11.3; P=0.037], and a decrease in DASH scale score [29.6 (SD 17.5) vs 21.6 (SD 15.1), mean difference -7.9, 95% CI -13.7 to -2.2; P=0.009]. In contrast, the conventional rehabilitation programme only led to a decrease in DASH scale score [30.3 (SD 18.1) vs 25.1 (SD 15.8), mean difference -5.2, 95% CI -8.8 to -1.5; P=0.007].

CONCLUSION

These findings suggest that rehabilitation is useful in Parkinson's disease, and the VR rehabilitation programme was more effective in determining overall improvement than the conventional rehabilitation programme.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02807740.

Multicentre evaluation of case volume in minimally invasive hepatectomy

Background

Surgical outcomes may be associated with hospital volume and the influence of volume on minimally invasive liver surgery (MILS) is not known.

Methods

Patients entered into the prospective registry of the Italian Group of MILS from 2014 to 2018 were considered. Only centres with an accrual period of at least 12 months and stable MILS activity during the enrolment period were included. Case volume was defined by the mean number of minimally invasive liver resections performed per month (MILS/month).

Results

A total of 2225 MILS operations were undertaken by 46 centres; nine centres performed more than two MILS/month (1376 patients) and 37 centres carried out two or fewer MILS/month (849 patients). The proportion of resections of anterolateral segments decreased with case volume, whereas that of major hepatectomies increased. Left lateral sectionectomies and resections of anterolateral segments had similar outcome in the two groups. Resections of posterosuperior segments and major hepatectomies had higher overall and severe morbidity rates in centres performing two or fewer MILS/month than in those undertaking a larger number (posterosuperior segments resections: overall morbidity 30·4 versus 18·7 per cent respectively, and severe morbidity 9·9 versus 4·0 per cent; left hepatectomy: 46 versus 22 per cent, and 19 versus 5 per cent; right hepatectomy: 42 versus 34 per cent, and 25 versus 15 per cent).

Conclusion

A volume–outcome association existed for minimally invasive hepatectomy. Complex and major resections may be best managed in high-volume centres.

Microdosimetry at the CATANA 62 MeV proton beam with a sealed miniaturized TEPC

A new mini-TEPC with cylindrical sensitive volume of 0.9 mm in diameter and height, and with external diameter of 2.7 mm, has been developed to work without gas flow. With such a mini counter we have measured the physical quality of the 62 MeV therapeutic proton beam of CATANA (Catania, Italy). Measurements were performed at six precise positions along the Spread-Out Bragg Peak (SOBP): 1.4, 19.4, 24.6, 29.0, 29.7 and 30.8 mm, corresponding to positions of clinical relevance (entrance, proximal, central, and distal-edge of the SOBP) or of high lineal energy transfer (LET) increment (distal-dose drop off). Without refilling the microdosimeter with new gas, the measurements were repeated at the same positions 4 months later, in order to study the stability of the response in sealed-mode operation. From the microdosimetric spectra the frequency-mean lineal energy y-_F and the dose-mean lineal energy y-_D were derived and compared with average LET values calculated by means of Geant4 simulations. The comparison points out, in particular, a good agreement between microdosimetric y-_D and the total dose-average LET¯_d, which is the average LET of the mixed radiation field, including the contribution by nuclear reactions.

Management of Fournier's gangrene non-healing wounds by autologous skin micrograft biotechnology: a new technique

Fournier's gangrene is an acute bacterial infection producing necrosis of the perineum and external genitalia that generally affects elderly men. Although skin grafts and flaps are the standard procedure for reconstruction, sometimes wounds can become chronic. Rigenera Protocol is a new technique based on autologous skin micrografts that reactivates and supports wound healing. A 40-year-old male with Fournier's gangrene, due to a rectal microperforation following diarrhoea, was treated with surgical debridement, negative pressure wound therapy and subsequently coverage with skin grafts. He developed non-healing wounds treated by Rigenera protocol after two months of advanced wound dressings. This technique is based on skin micrografts obtained by mechanical dermal disgregation to provide mesenchymal stem cells and extracellular matrix to the wound. The suspension injected into the wound triggers reactivation of healing without significant residual scarring on both donor site and treated area. Non-healing wounds were reduced by 15% at day 7 and by 50% after 30 days. Wounds completely healed after seventy days. The regenerated tissue appeared closer to skin graft than to scar tissue. This report shows how the use of skin micrografts through Rigenera protocol can be a useful method to reactivate wound healing resulting from Fournier's gangrene, with no discomfort for patient in a practical, safe and easy way.

Enhanced recovery pathways in colorectal surgery: a consensus paper by the Associazione Chirurghi Ospedalieri Italiani (ACOI) and the PeriOperative Italian Society (POIS)

Enhanced Recovery After Surgery (ERAS) pathway is a multi-disciplinary, patient-centered protocol relying on the implementation of the best evidence-based perioperative practice. In the field of colorectal surgery, the application of ERAS programs is associated with up to 50% reduction of morbidity rates and up to 2.5 days reduction of postoperative hospital stay. However, widespread adoption of ERAS pathways is still yet to come, mainly because of the lack of proper information and communication. Purpose of this paper is to support the diffusion of ERAS pathways through a critical review of the existing evidence by members of the two national societies dealing with ERAS pathways in Italy, the PeriOperative Italian Society (POIS) and the Associazione Italiana Chirurghi Ospedalieri (ACOI), showing the results of a consensus development conference held at Matera, Italy, during the national ACOI Congress on June 10, 2019.

Development and validation of a staging system for gastric adenocarcinoma after neoadjuvant chemotherapy and gastrectomy with D2 lymphadenectomy

BACKGROUND

Neoadjuvant chemotherapy followed by gastrectomy with D2 lymphadenectomy is commonly used for patients with locally advanced gastric adenocarcinoma. The eighth AJCC ypTNM staging system was validated based on patients undergoing more limited lymphadenectomy (less than D2). The aim of this study was to develop a system for accurate staging of patients with locally advanced gastric adenocarcinoma who receive neoadjuvant chemotherapy followed by gastrectomy with D2 lymphadenectomy.

METHODS

A modified system of ypTNM was developed, based on overall survival (OS) of patients receiving neoadjuvant chemotherapy followed by gastrectomy with D2 lymphadenectomy at Memorial Sloan Kettering Cancer Center, and validated using data from an international cohort of patients who had similar treatment.

RESULTS

Of 325 patients in the derivation cohort, 33 (10·2 per cent) had ypT0 N0/+ tumours, which are not classifiable under the AJCC system. The 5-year OS rate for modified ypTNM stages I, II, IIIA and IIIB was 89, 71, 42·3 and 10 per cent respectively, compared with 82, 65·2 and 24·1 for AJCC stages I, II and III respectively. The concordance index (0·730 versus 0·709), estimated area under the curve (0·765 versus 0·740) and time-dependent receiver operating characteristic (ROC) curve throughout the observation period were all superior for modified ypTNM staging. For the validation cohort of 186 patients, the modified system was again better at separating patients into prognostic groups for OS.

CONCLUSION

The modified ypTNM staging system improves the accuracy of OS prediction for patients treated with neoadjuvant chemotherapy followed by gastrectomy with D2 lymphadenectomy.

ASSESSING THE CONTRIBUTION OF CROSS-SECTIONS TO THE UNCERTAINTY OF MONTE CARLO CALCULATIONS IN MICRO- AND NANODOSIMETRY

Within EURADOS Working Group 6 'Computational Dosimetry', the micro and nanodosimetry task group 6.2 has recently conducted a Monte Carlo (MC) exercise open to participants around the world. The aim of this exercise is to quantify the contribution to the uncertainty of micro and nanodosimetric simulation results arising from the use of different electron-impact cross-sections, and hence physical models, employed by different MC codes (GEANT4-DNA, PENELOPE, MCNP6, FLUKA, NASIC and PHITS). Comparison of the participants' simulation results for both micro and nanodosimetric quantities using different MC codes was the first step of the exercise. The deviation between results is due to different cross-sections but also different tracking methods and particle transport cut-off energies. The second step of the exercise will involve using identical cross-section datasets to account only for the other variations in the first step, thus enabling the determination of the uncertainty contribution due to different cross-sections. This paper presents a comparison of the MC simulation results obtained in the first part of the exercise. For the microdosimetric simulations, particularly in the configuration where the electron source is contained within the micrometric target, the choice of MC code has a small influence on the results. For the nanodosimetric results, on the other hand, the mean ionisation cluster size distribution (ICSD) was sensitive to the physical models used in the MC codes. The ICSD was therefore chosen to study the influence of different cross-section data on the uncertainty of simulation results.

MICRODOSIMETRIC MEASUREMENT OF SECONDARY RADIATION IN THE PASSIVE SCATTERED PROTON THERAPY ROOM OF iTHEMBA LABS USING A TISSUE-EQUIVALENT PROPORTIONAL COUNTER

Measurements of the dose equivalent at different distances from the isocenter of the proton therapy center at iThemba LABS were previously performed with a tissue-equivalent proportional counter (TEPC). These measurements showed that the scattered radiation levels were one or two orders of magnitude higher in comparison to other passive scattering delivery systems. In order to reduce these radiation levels, additional shielding was installed shortly after the measurements were done. Therefore, the aim of this work is to quantify and assess the reduction of the secondary doses delivered in the proton therapy room at iThemba LABS after the installation of the additional shielding. This has been performed by measuring microdosimetric spectra with a TEPC at 11 locations around the isocenter when a clinical modulated beam of 200 MeV proton was impinging onto a water phantom placed at the isocenter.

SOI microdosimetry and modified MKM for evaluation of relative biological effectiveness for a passive proton therapy radiation field

With more patients receiving external beam radiation therapy with protons, it becomes increasingly important to refine the clinical understanding of the relative biological effectiveness (RBE) for dose delivered during treatment. Treatment planning systems used in clinics typically implement a constant RBE of 1.1 for proton fields irrespective of their highly heterogeneous linear energy transfer (LET). Quality assurance tools that can measure beam characteristics and quantify or be indicative of biological outcomes become necessary in the transition towards more sophisticated RBE weighted treatment planning and for verification of the Monte Carlo and analytical based models they use. In this study the RBE for the CHO-K1 cell line in a passively delivered clinical proton spread out Bragg peak (SOBP) is determined both in vitro and using a silicon-on-insulator (SOI) microdosimetry method paired with the modified microdosimetric kinetic model. The RBE along the central axis of a SOBP with 2 Gy delivered at the middle of the treatment field was found to vary between 1.11-1.98 and the RBE for 10% cell survival between 1.07-1.58 with a 250 kVp x-ray reference radiation and between 1.19-2.34 and 0.95-1.41, respectively, for a Co60 reference. Good agreement was found between RBE values calculated from the SOI-microdosimetry-MKM approach and in vitro. A strong correlation between proton lineal energy and RBE was observed particularly in the distal end and falloff of the SOBP.