Progesterone,fluid, and electrolytes in premenstrual syndrome.

Changes in mood, plasma progesterone concentration, urinary volume, sodium excretion, sodium:potassium ratio, and body weight during the menstrual cycle were determined in 18 women with premenstrual syndrome and 10 symptomless (control group) women. Plasma progesterone concentration was higher in the women with symptoms during the postovulatory phase of the cycle, and the peak progesterone concentration appeared earlier. The changes in progesterone concentration were accompanied by a natriuresis and diuresis that fell towards preovulatory values in the premenstrual phase. Sodium retention was not confined to any definite period. Mood symptoms occurred after the changes in progesterone and electrolyte concentrations. Progesterone deficiency is probably not the cause of premenstrual syndrome. Thus treatment with progesterone is probably illogical unless a deficiency is detected. Treatment should be aimed at preventing the natriuretic effect of progesterone in the postovulatory phase and the sodium-retaining and water-retaining effects of aldosterone in the premenstrual phase.     

Association of the MC4R V103I polymorphism with the metabolic syndrome: the KORA Study

Objective: Epidemiological studies showing an association between the melanocortin‐4‐receptor (MC4R) 103I variant (rs2229616) and decreased BMI are complemented by functional studies; these suggest a mechanism for appetite regulation and a linkage signal for physical activity and dietary intake for the region encompassing the MC4R. This study aims to provide epidemiological evidence for showing the association of this polymorphism with features of the metabolic syndrome and with parameters related to energy expenditure and dietary habits as potential mediators. Methods and Procedures: We analyzed this polymorphism in 7,888 adults of a population‐based cross‐sectional study applying regression‐based statistical models. Results: Carriers of the MC4R 103I (3.7%) exhibited a significantly decreased waist circumference (–1.46 cm, P = 0.020), decreased glycosylated hemoglobin (HbA_1c) (–0.09%, P = 0.040), and increased HDL‐cholesterol (HDL‐C) (+1.76 mg/dl, P = 0.056), but no change in blood pressure. The odds of having three or more components of the metabolic syndrome were substantially reduced among carriers of MC4R 103I (odds ratio (OR) = 0.46, P = 0.003). Controlling for BMI reduced the HbA_1c and HDL‐C association. Mediator analyses revealed a borderline association of MC4R 103I with carbohydrate intake (OR = 1.26, P = 0.059) possibly mediating association with leanness. Discussion: Our representative study of well‐phenotyped Europeans is the first to describe the association of the MC4R V103I with the metabolic syndrome and with a nutrient‐related phenotype. Our data support the idea that this polymorphism plays a role in appetite regulation that not only affects BMI, but also other features of the metabolic syndrome. It further establishes that the association of the MC4R V103I with obesity and related phenotypes is genuine.     

Analysis of the effects of hypothalamic-pituitary-adrenal axis activity in menstrual cycle on ankle proprioception,dynamic balance scores and visual-auditory reaction times in healthy young women

Objectives:Menstrual cycle (MC) can affect not only the female reproductive system, but also functions such as neuromuscular performance. For this reason, the aim of this study is to investigate the effect of hypothalamic-pituitary-adrenal axis (HPA) activity in MC on proprioception, balance and reaction times.Methods:For cortisol analysis, saliva samples were taken from the same women (n=43) in the four phases of MC. While State Trait Anxiety Inventory-I (STAI-I) was applied in each phase to support cortisol analysis, pain was measured with visual analogue scale (VAS). Proprioception, dynamic balance, visual and auditory reaction times (VRT-ART) measurements were made in the four phases of MC.Results:Cortisol, STAI-I and VAS scores, angular deviations in proprioception measurements, dynamic balance scores, VRT and ART measurements were found to show statistically significant difference between MC phases (p<0.05). As a result of the post hoc test conducted to find out which MC phase the statistical difference resulted from, it was found that statistically significant difference was caused by the mensturation (M) phase (p<0.05).Conclusions:It was found that neuromuscular performance and postural control was negatively affected by HPA axis activity in M phase of MC and by pain, which is a significant menstrual symptom.     

The dreams of women with and without severe emotional behavioral premenstrual symptoms.

Women with severe premenstrual symptoms, who tend to have more mood changes during the late luteal phase of their cycle than do women with few or no symptoms, often complain of having unpleasant dreams. This study examined whether these women experienced more intense negative dream emotions during the late luteal phase of their cycle compared with women with minimal symptoms. It also examined whether there was a relationship between presleep mood and dream affect. Seventeen women participated in the study (9 with severe symptoms, 8 with minimal symptoms). Analyses of variance revealed an increase in negative dream affect and misfortunes during the late luteal phase (p     

Self‐reported activation during the premenstrual and menstrual phases of the menstrual cycle

Abstract

A total of 171 female subjects completed a self‐report questionnaire dealing with activation (AD‐ACL) during the premenstrual and menstrual phases of their cycles. Significant variation between the two phases was found for all four activation factors: activation was highest premenstrually. Contraceptive use interacted significantly with cycle phase for the General Activation factor. Subjects taking oral contraceptive preparations also had lower scores on the Deactivation‐Sleep factor.     

Efficacy of progesterone and progestogens in management of premenstrual syndrome: systematic review

ObjectiveTo evaluate the efficacy of progesterone and progestogens in the management of premenstrual syndrome.DesignSystematic review of published randomised, placebo controlled trials.ResultsOverall standardised mean difference for all trials that assessed efficacy of progesterone (by both routes of administration) was −0.028 (95% confidence interval −0.017 to −0.040). The odds ratio was 1.05 (1.03 to 1.08) in favour of progesterone, indicating no clinically important difference between progesterone and placebo. For progestogens the overall standardised mean was −0.036 (−0.014 to −0.060), which corresponds to an odds ratio of 1.07 (1.03 to 1.11) showing a statistically, but not clinically, significant improvement for women taking progestogens.ConclusionThe evidence from these meta-analyses does not support the use of progesterone or progestogens in the management of premenstrual syndrome.

What is already known on this topic

The premenstrual syndrome affects about 1.5 million women in the United KingdomThere are numerous treatment options, progesterone being one of the most strongly advocatedProgesterone and progestogens are among the most widely prescribed treatments for premenstrual syndrome in the United Kingdom and the United States

What this study adds

There is no evidence to support the claimed efficacy of progesterone in the management of premenstrual syndromeThere is insufficient evidence to make a definitive statement about progestogens, but current evidence suggests that they are not likely to be effective     

Tripeptide IRW initiates differentiation in osteoblasts via the RUNX2 pathway

BackgroundOsteoblasts maintain the structural integrity of bone via differentiation and mineralization; therefore, their malfunction or reduced activity can cause serious bone disorders. Although studies have demonstrated the association between nutrients and bone, research on food-derived bioactive peptides and bone health are scanty.MethodsOsteoblasts MC3T3-E1 were treated with IRW (50 and 25 μM). Cell proliferation, cell cycle, osteoblastic differentiation, and mineralization were tested to evaluate the effects of IRW on osteogenesis promotion. The activation of PI3K-Akt-RUNX2 pathway and collagen synthesis were investigated to better understand the functions of IRW.ResultsIRW treatment (50 and 25 μM) in MC3T3-E1 cells caused a significant increase in cell proliferation by increasing the percentage of S and G2/M phase. Furthermore, IRW promoted mineralization in MC3T3-E1 cells. Mechanistically, we found that IRW treatment resulted in a 4-fold increase of Akt serine phosphorylation and a 2-fold increase of its downstream target RUNX2. Expression levels of RUNX2 associated proteins were concomitantly altered: ALP (2-fold increase), Col1A2 (2-fold increase), RANKL (2-fold decrease), and OPG (2-fold increase). Meanwhile, a parallel collagen synthesis pathway was found to contribute to IRW-stimulated osteogenesis.ConclusionsIRW, an egg-derived small bioactive peptide enhances osteoblastic activity and stimulates osteogenesis. The stimulation is primarily due to the activation of PI3K-Akt-RUNX2 pathway and its downstream effectors, accompanied by a secondary collagen synthesis pathway.General significanceOur results revealed the positive effects of tripeptide IRW on regulating osteogenesis and collagen synthesis, indicating its potential for the prevention or treatment of osteoporosis.     

Association of Plasma Parathyroid Hormone with Metabolic Syndrome and Risk for Cardiovascular Disease

ObjectiveTo review the current literature investigating the association of plasma parathyroid hormone (PTH) with the prevalence of metabolic syndrome and the risk for cardiovascular disease (CVD).MethodsWe conducted a search of PubMed and Medline database using the terms hyperparathyroidism, metabolic syndrome, hypertension, hyperlipidemia, hyper-glycemia, and CVD. We reviewed relevant studies from 2004 to 2012.ResultsThe current literature assessing the association of plasma PTH levels with metabolic syndrome and CVD is inconsistent; however, positive associations among hyperparathyroidism, metabolic syndrome, and CVD were found in a majority of the studies. The differences in the study populations may partly explain the mixed results.ConclusionIn the general population, a high serum PTH level predisposes patients to CVD mortality. Further research is needed to determine the role of PTH in the etiology of metabolic syndrome and CVD. (Endocr Pract. 2013;19:712-717)     

Association of the MC4R V103I Polymorphism With Obesity: A Chinese Case–control Study and Meta‐analysis in 55,195 Individuals

Recently, large‐scaled studies suggested a negative association of the infrequent allele of the melanocortin‐4 receptor (MC4R) V103I polymorphism with obesity. We conducted a Chinese case–control study, meta‐analysis in East Asians and in all populations, in order to further assess the association between the V103I polymorphism and reduced body weight and to explore whether the association varies among different ethnic groups. We conducted a case–control study to analyze this polymorphism in 2,012 children of two independent study groups from Beijing, China, no association was found between the V103I polymorphism and obesity or obesity‐related phenotypes (P > 0.10). In the meta‐analysis of 3,526 individuals from six East Asian studies, I103 carriers had a 31% lower risk for obesity (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.50–0.94, P = 0.02). Subsequently, we performed a large meta‐analysis of the six East Asian studies and 31 studies of other ethnic groups, involving 55,195 individuals with 19,822 obese cases and 35,373 nonobese controls. In total, the individuals with I103 allele had a 21% lower risk for obesity (OR = 0.79, 95% CI: 0.71–0.88, P < 0.0001). In conclusion, this study confirmed and extended the previous findings, suggesting the MC4R V103I polymorphism is negatively associated with human obesity. It provides significant evidence for the association in East Asian populations. Further large‐scaled studies in East Asian populations are needed to validate the association.     

Type II diabetes and metabolic syndrome in relation to head and neck squamous cell carcinoma risk: A SEER-Medicare database study

BackgroundDiabetes and metabolic syndrome have been found to increase the risk of various cancers. Previous studies indicated that diabetes may increase the risk of head and neck squamous cell carcinoma (HNSCC). Metabolic syndrome has not been investigated as a risk factor. We tested whether type II diabetes or metabolic syndrome were associated with HNSCC using a very large database of medical administrative records, providing the ability to investigate relatively weak effects and stratify by subgroups.MethodsWe identified persons diagnosed with HNSCC between 1994 and 2007 in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. We selected controls from a 5% sample of Medicare beneficiaries and frequency matched to cases on sex and duration of enrollment. We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between type II diabetes/metabolic syndrome and HNSCC, adjusted for potential confounders, among 14,022 cases and 42,066 controls.ResultsWe observed a very weak inverse association between type II diabetes and HNSCC (OR = 0.92; 95% CI, 0.88–0.96) and a moderate inverse association for metabolic syndrome (OR = 0.81; 95% CI, 0.78–0.85). Associations were modified by tobacco use, with null results for type II diabetes among never users (OR = 1.00; 95% CI, 0.95–1.06) and inverse associations among ever users (OR = 0.80; 95% CI, 0.75–0.86).ConclusionsWe observed moderate inverse associations between metabolic syndrome and HNSCC and weak inverse associations between type II diabetes and HNSCC, which was contrary to the evidence to date. Inadequate control for confounding factors, such as overweight/obesity, may have influenced results.     

T3111C CLOCK SINGLE NUCLEOTIDE POLYMORPHISM AND MOOD DISORDERS: A META-ANALYSIS

It has been hypothesized that abnormalities in the molecular clock underlie the development of mood disorders, in the direction of higher prevalence in individuals with a reduced flexibility to adapt to important regulations of mood in response to changes in seasons, stress levels, sleep schedules, and time zones. In particular, a T/C change (rs1801260) at the 3111 position of the circadian locomotor output cycles kaput (CLOCK) gene has been explored in psychiatry disorders. This meta-analysis has been undertaken to investigate the association between rs1801260 and both mood disorders and depression severity, shedding light on previous controversial results and providing better power to detect smaller effect sizes. PubMed and ISI databases were searched for studies focused on the association between rs1801260 and mood disorders spectrum. Quality of studies was assessed. We found no association between CLOCK genotypes and mood disorders, even when we separately investigated ethnical homogeneous or unipolar disorder studies. No association was found regarding severity of depression either. The methodological quality of the studies has been found to be medium-high. Our meta-analysis shows no association between rs1801260 and mood disorders (as a complete phenotype) or depression severity and points out the necessity of further research in order to better understand the underlying biological machinery of circadian dysfunction in subjects affected by mood disorders. (Author correspondence: alessandro.serretti@unibo.it)     

The effect of zinc supplementation on brain derived neurotrophic factor: A meta-analysis

BackgroundZinc in one of the most abundant trace minerals in human body which is involved in numerous biological pathways and has variety of roles in the nervous system. It has been assumed that zinc exerts its role in nervous system through increasing brain derived neurotrophic factor (BDNF) concentrations.ObjectivesPresent meta-analysis was aimed to review the effect of zinc supplementation on serum concentrations of BDNF.Methods and materialsFour electronic databases (Pubmed, Scopus, Web of Science, Embase) were searched for identifying studies that examined BDNF levels prior and after zinc supplementation up to May 2020. According to the Cochrane guideline, a meta-analysis was performed to pool the effect size estimate (Hedges’ test) of serum BDNF across studies. Risk of publication bias was assessed using a funnel plot and Egger’s test.ResultsFive studies were eligible and 238 participants were included. These studies enrolled subjects with premenstrual syndrome, diabetic retinopathy, major depression disorder, overweight/obese and obese with mild to moderate depressive disorders. Zinc supplementation failed to increase blood BDNF concentrations with effect size of 0.30 (95 % CI: -0.08, 0.67, P = 0.119). Funnel plot did not suggest publication bias.ConclusionZinc supplementation may not significantly increase BDNF levels. However, the small number of included articles and significant heterogeneity between them can increase the risk of a false negative result; therefore, the results should be interpreted with caution.     

Increased depressive-like traits in an animal model of premenstrual irritability

Women are at higher risk of anxiety and mood disorders, especially at transitions across the reproductive life cycle (premenstruum, postpartum, menopause). Premenstrual dysphoric disorder (PMDD) is one of female mood disorders associated with changing ovarian hormone levels. Because anxiety and depression frequently occur in women with PMDD, premenstrual dysphoria might be a manifestation of certain vulnerability traits increasing the risk of those disorders. The present study was conducted to elucidate a potential association between estrous cycle-dependent aggression, the rodent model of "premenstrual irritability" (resident-intruder test), and anxiety (elevated plus maze), depressive-like traits (forced swim test) as well as carbohydrate craving in female Wistar rats. Some aggressive and nonaggressive females were restraint-stressed before testing to determine their sensitivity to stress at different hormonal stages. The results revealed that females expressing the estrous cycle-dependent aggression but not those not expressing cycle-dependent aggression spent longer time immobile and shorter time swimming in the forced swim test at metestrus compared to proestrus phase of the estrous cycle. There was no difference between aggressive and nonaggressive females in anxiety, locomotor activity and sensitivity to restraint stress and sucrose consumption. The present study suggests a common neurobiological background for the estrous cycle-dependent aggression and depressive-like traits in rodents. This phenomenon could potentially aid the elucidation of premenstrual emotional dysfunctions and might be used as an ethological model to study a biochemical and genetic proneness to depression.     

Explore the Features of Brain-Derived Neurotrophic Factor in Mood Disorders

Objectives

Brain-derived neurotrophic factor (BDNF) plays important roles in neuronal survival and differentiation; however, the effects of BDNF on mood disorders remain unclear. We investigated BDNF from the perspective of various aspects of systems biology, including its molecular evolution, genomic studies, protein functions, and pathway analysis.

Methods

We conducted analyses examining sequences, multiple alignments, phylogenetic trees and positive selection across 12 species and several human populations. We summarized the results of previous genomic and functional studies of pro-BDNF and mature-BDNF (m-BDNF) found in a literature review. We identified proteins that interact with BDNF and performed pathway-based analysis using large genome-wide association (GWA) datasets obtained for mood disorders.

Results

BDNF is encoded by a highly conserved gene. The chordate BDNF genes exhibit an average of 75% identity with the human gene, while vertebrate orthologues are 85.9%-100% identical to human BDNF. No signs of recent positive selection were found. Associations between BDNF and mood disorders were not significant in most of the genomic studies (e.g., linkage, association, gene expression, GWA), while relationships between serum/plasma BDNF level and mood disorders were consistently reported. Pro-BDNF is important in the response to stress; the literature review suggests the necessity of studying both pro- and m-BDNF with regard to mood disorders. In addition to conventional pathway analysis, we further considered proteins that interact with BDNF (I-Genes) and identified several biological pathways involved with BDNF or I-Genes to be significantly associated with mood disorders.

Conclusions

Systematically examining the features and biological pathways of BDNF may provide opportunities to deepen our understanding of the mechanisms underlying mood disorders.     

Changes in mood, cognitive performance and appetite in the late luteal and follicular phases of the menstrual cycle in women with and without PMDD (premenstrual dysphoric disorder)

Although it's been reported that women with premenstrual dysphoric disorder (PMDD) have increased negative mood, appetite (food cravings and food intake), alcohol intake and cognitive deficits premenstrually, few studies have examined these changes concurrently within the same group of women or compared to women without PMDD. Thus, to date, there is not a clear understanding of the full range of PMDD symptoms. The present study concurrently assessed mood and performance tasks in 29 normally cycling women (14 women who met DSM-IV criteria for PMDD and 15 women without PMDD). Women had a total of ten sessions: two practice sessions, 4 sessions during the follicular phase and 4 sessions during the late luteal phase of the menstrual cycle. Each session, participants completed mood and food-related questionnaires, a motor coordination task, performed various cognitive tasks and ate lunch. There was a significant increase in dysphoric mood during the luteal phase in women with PMDD compared to their follicular phase and compared to Control women. Further, during the luteal phase, women with PMDD showed impaired performance on the Immediate and Delayed Word Recall Task, the Immediate and Delayed Digit Recall Task and the Digit Symbol Substitution Test compared to Control women. Women with PMDD, but not Control women, also showed increased desire for food items high in fat during the luteal phase compared to the follicular phase and correspondingly, women with PMDD consumed more calories during the luteal phase (mostly derived from fat) compared to the follicular phase. In summary, women with PMDD experience dysphoric mood, a greater desire and actual intake of certain foods and show impaired cognitive performance during the luteal phase. An altered serotonergic system in women with PMDD may be the underlying mechanism for the observed symptoms; correspondingly, treatment with specific serotonin reuptake inhibitors (SSRIs) remains the preferred treatment at this time.     

Female menstrual phases modulate human prefrontal asymmetry: A magnetoencephalographic study

We previously reported that the trait/baseline prefrontal cortex (PFC) activity expresses a dynamic plasticity during female menstrual cycle. The shift of asymmetric lateralization of PFC baseline activity pinpoints a possible emotional regulation of negative affection. The current emotional Go/NoGo study aimed to investigate the state PFC responses of different menstrual phases during fear facial stimulation in fourteen healthy women. Our data disclosed that the menstrual cycle was coupled with a shift of asymmetric lateralization of frontal activation across different menstrual phases. Evoked magnetic field activity in the time window 200-300 ms (M1) and 300-450 ms (M2) after stimulus onset demonstrated significant interactions between hemispheric side and menstrual phase. The right hemispheric dominance in periovulatory phase (OV) changed to left hemispheric dominance in menstrual (MC) phase. Significant association between the anxiety score and the left PFC activation was particularly observed in MC phase. Our study revealed a plastic resilience of functional organization of human brain and a dynamic automaticity of inter-hemispheric synergism for possible adaptive regulation under the aversive confrontation in accordance with hormonal fluctuation during the menstrual cycle.     

A study of the interplay effect in radiation therapy using a Monte-Carlo model

PurposeIn modulated radiotherapy, breathing motion can lead to Interplay (IE) and Blurring (BE) effects that can modify the delivered dose. The aim of this work is to present the implementation, the validation and the use of an open-source Monte-Carlo (MC) model that computes the delivered dose including these motion effects.MethodsThe MC model of the Varian TrueBeam was implemented using GATE. The dose delivered by different modulated plans is computed for several breathing patterns. A validation of these MC predictions is achieved by a comparison with measurements performed using a dedicated programmable motion platform, carrying a quality assurance phantom. A specific methodology was used to separate the IE and the BE. The influence of different motion parameters (period, amplitude, shape) and plan parameters (volume margin, dose per fraction) was also analyzed.ResultsThe MC model was validated against measurement performed with motion with a mean 3D global gamma index pass rate of 97.5% (3%/3 mm). A significant correlation is found between the IE and the period and the antero-posterior amplitude of the motion but not between the IE and the CTV margin or the shape of motion. The results showed that the IE increases D2% and decreases the D98% of CTV with mean values of +6.9% and −3.3% respectively.ConclusionsWe validated the feasibility to assess the IE using a MC model. We found that the most important parameter is the number of breathing cycles that must be greater than 20 for one arc to limit the IE.     

Male-origin microchimerism and endometrial cancer: A prospective case-cohort study

BackgroundMany women carry male cells of presumed fetal origin–so-called male-origin microchimerism (MOM)–in their circulation and tissues. Studies have found reduced risks of hormone dependent cancers, including breast and ovarian cancer, among MOM-positive women. The aim of this study was to investigate the association between MOM and endometrial cancer.MethodsWe designed a prospective case-cohort study including 76 cases and 505 controls from the Diet, Cancer and Health cohort aged 50–64 years and cancer-free at enrolment in 1993–1997. We analyzed blood samples for the presence of Y-chromosome (DYS14). We examined the association between MOM and endometrial cancer in weighted Cox regression models. As a negative control outcome, we studied the association between MOM and injuries to test for spurious associations.ResultsWe detected MOM in 65.9% controls and 54.0% cases. While we observed no overall association between MOM and endometrial cancer (HR=0.73, 95% CI: 0.47–1.15), we found a borderline significantly reduced rate of Type 1 endometrial cancer (HR=0.66, 95% CI: 0.39–1.00), but not other types of endometrial cancers (HR=1.00, 95% CI: 0.35–2.90). The reduced rate was not modified by hormonal exposure (P = 0.79). We found no association between MOM and risk of injuries (HR=0.96, 95% CI: 95% CI: 0.78–1.21).ConclusionsOur study suggests that MOM is inversely associated with Type 1 endometrial cancer, without evidence of an interaction with hormonal exposure. We encourage future research to confirm our findings.     

Association between Common Polymorphism near the MC4R Gene and Obesity Risk: A Systematic Review and Meta-Analysis

Background

Genome-wide association studies on Europeans have shown that two polymorphisms (rs17782313, rs12970134) near the melanocortin 4 receptor (MC4R) gene were associated with increased risk of obesity. Subsequently studies among different ethnic populations have shown mixed results with some confirming and others showing inconsistent results, especially among East Asians and Africans. We performed a comprehensive meta-analysis of various studies from different ethnic populations to assess the association of the MC4R polymorphism with obesity risk.

Methods

We retrieved all published literature that investigated association of MC4R variants with obesity from PubMed and Embase. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model.

Results

A total of 61 studies (80,957 cases/220,223 controls) for rs17782313 polymorphism (or proxy) were included in the meta-analysis. The results suggested that rs17782313 polymorphism was significantly associated with obesity risk (OR = 1.18, 95%CI = 1.15–1.21, p<0.001). Similar trends were observed among subgroups of Europeans and East Asians, adults and children, studies with high quality score, and for each five MC4R polymorphisms independently.

Conclusions

The present meta-analysis confirms the significant association of MC4R polymorphism with risk of obesity. Further studies should be conducted to identify the causal variant and the underlying mechanisms of the identified association.     

Proton range monitoring with in-beam PET: Monte Carlo activity predictions and comparison with cyclotron data

GoalProton treatment monitoring with Positron-Emission-Tomography (PET) is based on comparing measured and Monte Carlo (MC) predicted β⁺ activity distributions. Here we present PET β⁺ activity data and MC predictions both during and after proton irradiation of homogeneous PMMA targets, where protons were extracted from a cyclotron.Methods and materialsPMMA phantoms were irradiated with 62 MeV protons extracted from the CATANA cyclotron. PET activity data were acquired with a 10 × 10 cm² planar PET system and compared with predictions from the FLUKA MC generator. We investigated which isotopes are produced and decay during irradiation, and compared them to the situation after irradiation. For various irradiation conditions we compared one-dimensional activity distributions of MC and data, focussing on Δw50%, i.e., the distance between the 50% rise and 50% fall-off position.ResultsThe PET system is able to acquire data during and after cyclotron irradiation. For PMMA phantoms the difference between the FLUKA MC prediction and our data in Δw50% is less than 1 mm. The ratio of PET activity events during and after irradiation is about 1 in both data and FLUKA, when equal time-frames are considered. Some differences are observed in profile shape.ConclusionWe found a good agreement in Δw50% and in the ratio between beam-on and beam-off activity between the PET data and the FLUKA MC predictions in all irradiation conditions.