Dosimetric and biologic intercomparison between electron and proton FLASH beams

BACKGROUND AND PURPOSE

The FLASH effect has been validated in different preclinical experiments with electrons (eFLASH) and protons (pFLASH) operating at an average dose rate above 40 Gy/s. However, no systematic intercomparison of the FLASH effect produced by eFLASHvs. pFLASH has yet been performed and constitutes the aim of the present study.

MATERIALS AND METHODS

The electron eRT6/Oriatron/CHUV/5.5 MeV and proton Gantry1/PSI/170 MeV were used to deliver conventional (0.1 Gy/s eCONV and pCONV) and FLASH (≥110 Gy/s eFLASH and pFLASH) dose rates. Protons were delivered in transmission. Dosimetric and biologic intercomparisons were performed using previously validated dosimetric approaches and experimental murine models.

RESULTS

The difference between the average absorbed dose measured at Gantry 1 with PSI reference dosimeters and with CHUV/IRA dosimeters was -1.9 % (0.1 Gy/s) and + 2.5 % (110 Gy/s). The neurocognitive capacity of eFLASH and pFLASH irradiated mice was indistinguishable from the control, while both eCONV and pCONV irradiated cohorts showed cognitive decrements. Complete tumor response was obtained after an ablative dose of 20 Gy delivered with the two beams at CONV and FLASH dose rates. Tumor rejection upon rechallenge indicates that anti-tumor immunity was activated independently of the beam-type and the dose-rate.

CONCLUSION

Despite major differences in the temporal microstructure of proton and electron beams, this study shows that dosimetric standards can be established. Normal brain protection and tumor control were produced by the two beams. More specifically, normal brain protection was achieved when a single dose of 10 Gy was delivered in 90 ms or less, suggesting that the most important physical parameter driving the FLASH sparing effect might be the mean dose rate. In addition, a systemic anti-tumor immunological memory response was observed in mice exposed to high ablative dose of electron and proton delivered at CONV and FLASH dose rate.

Sex moderates the association between quantitative sensory testing and acute and chronic pain after total knee/hip arthroplasty

OBJECTIVES

Acute postsurgical pain (APSP) may persist over time and become chronic. Research on predictors for APSP and chronic postsurgical pain (CPSP) has produced inconsistent results. This observational study aimed to analyze psychological and psychophysical variables associated with APSP and CPSP after total knee or hip arthroplasty, and to explore the role of sex.

METHODS

Assessments were conducted before surgery, 48 h, and 3 months postsurgery, including questionnaires (sociodemographic, pain related, and psychological) and quantitative sensory testing (QST). Hierarchical linear regression models analyzed potential predictors of APSP and CPSP, and moderation analyses evaluated the role of sex.

RESULTS

The study included 63 participants undergoing total knee (34, 54%) or hip (29, 46%) arthroplasty. Thirty-one (49.2%) were female and 32 (50.8%) were male. APSP (48 h) was associated with impaired conditioned pain modulation (CPM) (β = 0.301, p = 0.019). CPSP (3 months) was associated with being female (β = 0.282, p = 0.029), longer presurgical pain duration (β = 0.353, p = 0.006), knee arthroplasty (β = -0.312, p = 0.015), higher APSP intensity (β = 373, p = 0.004), and impaired CPM (β = 0.126, p = 0.004). In multivariate analysis, these clinical variables were significant predictors of CPSP, unlike sex, and CPM (adj. R 2 = 0.349). Moderation analyses showed that wind-up ratio (WUR) was a significant predictor of APSP in men (WUR × sex: b = -1.373, p = 0.046) and CPM was a significant predictor of CPSP in women (CPM × sex: b = 1.625, p = 0.016).

CONCLUSIONS

Specific QST parameters could identify patients at risk for high-intensity APSP and CPSP, with sex as a moderator. This has important clinical implications for patient care, paving the way for developing tailored preventive pain management strategies.

Sucrose preference test: A systematic review of protocols for the assessment of anhedonia in rodents

Anhedonia is described as a decreased ability to experience rewarding and enjoyable activities, a core symptom of major depressive disorder. The sucrose preference test (SPT) is a widely used and reliable behavioural test to assess anhedonia in rodents, based on a two-bottle choice paradigm. To date, different protocols are in use, inducing variability between researchers and hampering comparisons between studies. We performed a systematic review of the SPT protocols used in 2021 to identify the parameters in which they differ and their potential impact. We searched a total of four databases (PubMed, Scopus, Web of Science and Science Direct), from 1st January 2021 to 31st December 2021, and screened a total of 1066 articles. After screening by title and abstract, a total of 415 articles were included in this review. We extracted and analysed the different procedures used, the type of sweet solution and the habituation, deprivation, and testing protocols. The overall quality of the studies was considered very good, however, SPT protocols were extremely variable between studies with a total of 65 different habituation protocols and 104 combinations of food/water deprivation and preference testing duration. As the SPT is one of the most used tests to assess anhedonia in rodents, this work raises awareness of the great variability in SPT protocols being currently used. Furthermore, we call for standardization in the protocol used, and overall improvement of data reporting of methodologies and results, to increase the consistency between studies and allow a better comparison of results between different labs.

Injection of kaolin/carrageenan in the rat knee joint induces progressive experimental knee osteoarthritis

ABSTRACT

Osteoarthritis (OA), the most common joint disorder worldwide, is characterized by progressive degeneration of articular and periarticular structures, leading to physical and emotional impairments that greatly affect the quality of life of patients. Unfortunately, no therapy has been able to halt the progression of the disease. Owing to the complexity of OA, most animal models are only able to mimic a specific stage or feature of the human disorder. In this work, we demonstrate the intraarticular injection of kaolin or carrageenan leads to the progressive degeneration of the rat's knee joint, accompanied by mechanical hyperalgesia and allodynia, gait impairments (reduced contact area of the affected limb), and radiological and histopathological findings concomitant with the development of human grade 4 OA. In addition, animals also display emotional impairments 4 weeks after induction, namely, anxious and depressive-like behaviour, important and common comorbidities of human OA patients. Overall, prolonging kaolin or carrageenan-induced monoarthritis mimics several important physical and psychological features of human OA in both male and female rodents and could be further applied in long-term studies of OA-associated chronic pain.

Unlocking the molecular realm: advanced approaches for identifying clinically and environmentally relevant bacteria

Rapid, effective, and specific identification of clinical and environmental bacterial pathogens is of major importance for their control. Traditionally, bacteria have been identified by phenotypic methods based on morphological, biochemical, and metabolic properties. While these methods are very useful in clinical practice, they have limitations including a poor ability to differentiate within and between species and time-consuming workflows. Newly developed molecular methods can greatly improve the accuracy of taxonomic characterization, identifying specific strains of medical or environmental importance. However, due to high costs and the need for trained professionals, these methods are not yet routine in diagnostic laboratories. Thus, disseminating knowledge on advances in molecular identification techniques is pivotal to make these methodologies accessible. The objective of this work was to review and discuss current molecular techniques for bacteria identification aiming to track and monitor microbial agents in clinical and environmental samples.

Clinical Outcomes Among Elderly People With Burns

Burns in the elderly are a public health concern. This study aimed to analyze etiology, clinical characteristics, and independent risk factors for outcomes of burns in elderly patients. This retrospective study included elderly patients (65 years and over) admitted to a major burn unit between 2006 and 2016. Demographic data, clinical characteristics and outcomes were analyzed. One hundred and thirty patients were included. Most were female (56.2%) and the highest incidence was among those aged 75-84 years. The median burn area was 10.5%. The incidence in winter (50%) was higher (p<0.001) and flame burns predominated (p<0.001). The mortality rate was 32.3%. Independent risk factors for death were older age, larger extent burns, need for escharotomy, and cardiac disease as comorbidity. Amongst the survivors, the median length of stay was 36 days. Development of pressure sores, need for skin grafts, larger extent burns, presence of full-thickness burns, and cardiac disease were shown to be significantly associated with increased length of stay amongst survivors. Preventive measures should target women aged between 75-84 years. Flame burns occurred more frequently in winter. Prognosis is related to age, extent of burns, need for escharotomy at admission, and cardiac disease.

Comparative neurotoxicity of dietary methylmercury and waterborne inorganic mercury in fish: Evidence of optic tectum vulnerability through morphometric and histopathological assessments

This work investigated the effects of inorganic mercury (iHg) and methylmercury (MeHg) on the fish optic tectum morphology, viz. in relation to: (i) vulnerability of specific optic tectum layers; (ii) preferential targeting of Hg forms to neurons or glial cells; (iii) comparative toxicity of iHg and MeHg in this brain area that is in the maintenance of several fish behaviors. Two experiments exposing juvenile white seabream (Diplodus sargus) to waterborne iHg [HgCl₂ (2 μg L^-1)] and dietary MeHg (8.7 μg g^-1) were performed, comprising both exposure (7 and 14 days; E7 and E14, respectively) and post-exposure (28 days; PE28) periods. Morphometric assessments were performed using stereological methods where the layers of the optic tectum were outlined, while its area and the number of neurons and glial cells were estimated. A histopathological assessment was also performed per section and per layer of optic tectum. iHg exposure did not trigger the loss of neurons during the exposure periods, while a decrease of glial cells was detected in a single layer of the optic tectum at E14. Differently, upon MeHg exposure, a decrease on the number of neurons and glial cells was found in several layers of optic tectum. In the post-exposure, both Hg forms triggered the loss of neurons, while only MeHg exposure led to a decrease on the number of glia cells. The histopathological assessment pointed out a higher toxicity of MeHg in the optic tectum layers, particularly in the post-exposure period, while no significant alterations were found in fish exposed to iHg. Hg forms targeted preferentially neurons. iHg and MeHg are relevant neurotoxicants to fish, with MeHg exposure leading to a higher toxicity than iHg in the optic tectum. After 28 days of post-exposure, iHg and MeHg neurotoxicity remained prominent, suggesting long-term effects of these toxicants.

Electronic device or regulated tobacco product? Learning from the diffusion of heated tobacco products in Spain

OBJECTIVES

Tobacco companies have introduced heated tobacco product (HTP) in many countries and marketed it on the grounds that it is a less harmful alternative to health. However, tobacco companies have been widely criticized for taking advantage of a loophole that allows electronic devices to circumvent regulations limiting tobacco advertising. This work aims to determine whether HTPs respected the rules that regulate tobacco advertising when it was introduced in Spain.

STUDY DESIGN

This is an observational epidemiological study.

METHODS

Using monthly time series data from September 2016 to June 2020, we analyzed whether the adoption of HTPs has followed the same behavior patterns as other brands that were introduced under the same conditions of use. The Bass model is used to analyze the diffusion of HTPs, and 30 other traditional cigarette brands introduced under the same conditions as this HTPs.

RESULTS

The adoption of HTPs in Spain has been like that of brands of slim cigarettes that are mistakenly considered to be healthier than traditional cigarettes. The results indicate that the use of HTPs has spread in the same way as additive-free and ultra-slim cigarette brands.

CONCLUSIONS

Policymakers should keep in mind that laws should restrict any marketing of tobacco products that promotes positive connotations between tobacco use and being healthy. If manufacturers are allowed to classify a category and/or brand of tobacco products as less harmful to health, the imitation effect is very high, leading to the proliferation of smoking.

Dosimetric and biologic intercomparison between electron and proton FLASH beams

Background and purpose

The FLASH effect has been validated in different preclinical experiments with electrons (eFLASH) and protons (pFLASH) operating at a mean dose rate above 40 Gy/s. However, no systematic intercomparison of the FLASH effect produced by e vs. pFLASH has yet been performed and constitutes the aim of the present study.

Materials and methods

The electron eRT6/Oriatron/CHUV/5.5 MeV and proton Gantry1/PSI/170 MeV were used to deliver conventional (0.1 Gy/s eCONV and pCONV) and FLASH (≥100 Gy/s eFLASH and pFLASH) irradiation. Protons were delivered in transmission. Dosimetric and biologic intercomparisons were performed with previously validated models.

Results

Doses measured at Gantry1 were in agreement (± 2.5%) with reference dosimeters calibrated at CHUV/IRA. The neurocognitive capacity of e and pFLASH irradiated mice was indistinguishable from the control while both e and pCONV irradiated cohorts showed cognitive decrements. Complete tumor response was obtained with the two beams and was similar between e and pFLASH vs. e and pCONV. Tumor rejection was similar indicating that T-cell memory response is beam-type and dose-rate independent.

Conclusion

Despite major differences in the temporal microstructure, this study shows that dosimetric standards can be established. The sparing of brain function and tumor control produced by the two beams were similar, suggesting that the most important physical parameter driving the FLASH effect is the overall time of exposure which should be in the range of hundreds of milliseconds for WBI in mice. In addition, we observed that immunological memory response is similar between electron and proton beams and is independent off the dose rate.

ASURE Clinical Trial Protocol: A Randomized, Placebo-Controlled, Proof-of-Concept Study Aiming to Evaluate Safety and Target Engagement following Administration of TW001 in Early Alzheimer's Disease Patients

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease with complex disease etiology and pathological processes. These include formation of plaques and tangles, aberrant lipid processing, neuroinflammation, cerebrovascular dysregulation, ion channel and mitochondrial dysfunction, and oxidative stress. Disease-modifying therapies focusing on all these different facets are needed. TW001 is an oral formulation with the radical scavenger edaravone as its active ingredient, targeting oxidative stress.

OBJECTIVES

This manuscript describes the trial design for Phase IIA Alzheimer Study Using oRal Edaravone (ASURE).

METHODS

ASURE is a randomized, placebo-controlled, proof-of-concept study aiming to evaluate safety and target engagement following administration of TW001 in early AD patients. Patients should have a biomarker confirmed diagnosis to be included in the trial and will be treated for 90 days. The primary endpoints include safety and effect of TW001 on oxidative stress biomarkers. Exploratory endpoints focus on a panel of AD(-related) fluid-based biomarkers and EEG. In addition, a recently developed cognitive functional composite (CFC) score will measure early signs of cognitive and functional effects of TW001.

RESULTS

This article outlines the design of the clinical study, no results are included.

CONCLUSIONS

The ASURE trial design is discussed, with a particular focus on fluid biomarkers, EEG, and CFC as endpoints. By testing multiple measures related to pathology, pharmacodynamics, EEG as proxy for cognition, and cognitive functional scores, it is expected that small changes will be detectable in trials of shorter duration. Moreover, the wide range of endpoints allows to make well-informed decisions for designing pivotal studies later.

Impact of the COVID-19 pandemic on the mental and physical health and overall wellbeing of university students in Portugal

Throughout the pandemic of COVID-19 caused by SARS-CoV-2, university students were considered a vulnerable risk group for mental health impairment and wellbeing deterioration. This study aimed at evaluating the pandemic's impact on the physical and mental health and wellbeing among students of a Portuguese university. This cross-sectional study included 913 participants and ran from June to October 2020. Data collected included sociodemographics, three mental health self-report questionnaires (Depression Anxiety Stress Scale, Eating Disorder Examination Questionnaire and Brief COPE) and lifestyle practices (eating and sleeping patterns, media, and entertainment habits) during the first months of the pandemic, which included a 72-day full national lockdown. Descriptive and correlational statistical analysis were conducted. Students' food habits changed during the pandemic, namely on the consumption of snacks and fast food and, overall, less balanced meals became more prevalent. Additionally, almost 70% of the students reported Body Mass Index changes, while 59% went through sleep pattern changes-these were more pronounced in women and younger students. Over half (67%) of the inquirees exhibited an increase in their stress, depression, and generalized anxiety symptoms. Also, the study demonstrates that students' lifestyles trended negatively during the pandemic and highlights how important regular psychological, health monitoring and emotional support is, amongst this somehow overlooked population throughout the pandemic. Universities should provide support to overcome challenges in future stressful situations. This study might have an impact on how universities and higher education systems approach their students in terms of mental and physical health monitoring and promotion in future situations, non-related with COVID. Moreover, it has a large sample of students well characterized in terms of mental and physical health, which might be of interest for future comparison with other worldwide group of students throughout stressful situations, such as tragic events, wars, pandemics.

Rapid deployment bioprostesis for aortic valve stenosis: single center short and long-term outcomes

Background

Despite recent advances, surgical aortic valve replacement (SAVR) remains the gold standard for most of the patients with aortic valve stenosis. The ageing population, with increased comorbidities and the rising of minimally invasive techniques, led to the development of new prosthetic devices of easier and faster implantation.

Purpose

This study aimed to analyse short and long-term outcomes of SAVR with rapid-deployment (RD) aortic bioprosthesis for isolated aortic valve stenosis

Method

Singe center, retrospective longitudinal cohort study of patients with isolated aortic valve stenosis who underwent elective aortic valve replacement using RD devices between 2014 and December 2021.

Continuous variables are presented with median (IQR) and were analyzed using Mann-Whitney test. Categorical variables are presented in percentage or frequency and were analyzed using chi-square test. Kaplan-Meyer survival curve was constructed base on collected data from national registry.

Results

A RD device was implanted in 358 patients with a median age of 75,8 years and Euroscore II of 2,3. Median cross clamp and extracorporeal circulation time were 27,4 and 36,7 min, respectively. No significant paravalvular leaks.

Intensive care unit (ICU) length of stay was 3 days with acute renal lesion (any stage-53,2%; Dialysis-2,5%), need for hemodynamic support (63,1%) and new onset atrial fibrillation (33,6%) being the most frequent post-operative complications. Stroke occurred in 0,6% of cases and mortality was 1,1%. Pacemaker implementation rate of 11%.

The mean follow-up time was 6,7 years with 90% 5-years survival rate. Mean gradients of 11,2±4,8 mmHg at 6 months

Conclusion

Surgical treatment of aortic valve stenosis using RD devices is safe, with a low mortality rate. ICU length of stay and hospital length of stay are reduced. Follow-up shows an excellent long-term survival and hemodynamic performance.

Funding Acknowledgement

Type of funding sources: None.

Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort

PURPOSE

After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation.

METHODS

A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age < 10 and ≥ 14 weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry.

RESULTS

Median UIC was 104 μg/L (IQR 62-189) in the overall population (n = 481) of which 19% had UIC < 50 µg/L. Forty three percent (n = 206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146 µg/L (IQR 81-260) and 74 µg/L (IQR 42-113) in ICS users and non-users, respectively (p < 0.001). Not using an ICS was an independent risk factor for iodine insufficiency [adjusted OR (95% CI) = 6.00 (2.74, 13.16); p < 0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p < 0.014).

CONCLUSIONS

A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine deficiency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt. Trial registration number NCT04010708, registered on the 8th July 2019.

Cytoskeleton disruption by the metabolic inhibitor 3-bromopyruvate: implications in cancer therapy

The small molecule 3-bromopyruvate (3BP), is an anticancer molecule that acts by hindering glycolysis and mitochondrial function leading to energy depletion and consequently, to cell death. In this work we have focused on understanding how the glycolytic inhibition affects cancer cell structural features. We showed that 3BP leads to a drastic decrease in the levels of β-actin and α-tubulin followed by disorganization and shrinkage of the cytoskeleton in breast cancer cells. 3BP inhibits cell migration and colony formation independently of the activity of metalloproteinases. To disclose if these structural alterations occurred prior to 3BP toxic effect, non-toxic concentrations of 3BP were used and we could observe that 3BP was able to inhibit energy production and induce loss of β-actin and α-tubulin proteins. This was accompanied with alterations in cytoskeleton organization and an increase in E-cadherin levels which may indicate a decrease in cancer cells aggressiveness. In this study we demonstrate that 3BP glycolytic inhibition of breast cancer cells is accompanied by cytoskeleton disruption and consequently loss of migration ability, suggesting that 3BP can potentially be explored for metastatic breast cancer therapy.

Magnetostructural coupling in RFeO3 (R = Nd, Tb, Eu and Gd)

We investigate the interplay of magnetization and lattice vibrations in rare-earth orthoferrites RFeO₃, with a specific focus on non-symmetry-breaking anomalies. To do so, we study the magnetization, magnon excitations and lattice dynamics as a function of temperature in NdFeO₃, TbFeO₃, EuFeO₃ and GdFeO₃. The magnetization shows distinct temperature anomalous behavior for all investigated rare-earth orthoferrites, even in the compounds with no phase transitions occurring at those temperatures. Through spin-phonon coupling, these magnetic changes are mirrored by the FeO₆ rotation mode for all the studied RFeO₃, revealing a common magnetostructural effect associated with the octahedra rotations. The R³⁺ oscillation modes evidence a Fe³⁺/R³⁺ spins cross-talk for the NdFeO₃ and TbFeO₃ cases. Our work sheds light into the common magnetostructural coupling in rare-earth orthoferrites, and the important role of magnetic anisotropy and spin-orbit coupling strength of the R-Fe interactions on the spin-reorientation transition at high temperatures.

Cycloid psychosis - from the past to the future: based on a case report

Introduction

The concept of cycloid psychosis has a long tradition in European psychiatry since it was introduced by Kleist in 1926. Nevertheless, this concept is not included explicitly in modern classifications, leading to a controversial discussion about its utility in current psychiatry.

Objectives

Starting from a case study, we intend to review the evolution of cycloid psychosis concept and analyze its role in modern psychiatry.

Methods

Non-systematic review of the literature and report of a case study.

Results

Following Kleist’s work, Leonhard described the three overlapping subtypes, and later Perris developed the first operational diagnostic criteria. Since then, this entity has shown a high diagnostic stability, validity and a good predictive diagnostic and prognostic value. We report a case of a 30-year-old woman, previous heathy, without regular medication, living with her parents and 5-year-old son, until she emigrated alone to Switzerland. After 10 days abroad, she was sent back to Portugal, and after organic disease and drug misuse exclusion, she was admitted in our inward with a clinical picture of perplexity, anxiety, thinking and behavioral disturbance with persecutory and poisoning delusions, auditory hallucinations, and total insomnia. Following rapid and full recovery, she was discharged 14 days later while being medicated with Paliperidone 3 mg/day and Lorazepam 4 mg/day, which was abandoned by her 2 months later, without relapse of the symptoms.

Conclusions

The current lack of a satisfactory system for categorizing acute, and remittent psychoses seems to be reason enough to remain awareness of this unique diagnostic entity, which is worthy of further investigation.

Disclosure

No significant relationships.