The Autism-Spectrum Quotient (AQ) measures the degree of autistic traits in clinical and non-clinical samples and has been validated in various countries and languages. However, the AQ has not been validated in Singapore, an Asian country whose population speaks predominantly English. Although previous validation studies have examined the distribution of scores, internal consistency, test-retest reliability and construct, convergent and discriminant validities in Asian countries using translated versions of the AQ and generally shown a suitable structure of the AQ, other studies testing cultural differences of the AQ have provided inconsistent results about whether differences exist in scores between Western and Asian samples. Additionally, while prior literature has consistently documented sex differences in AQ scores, findings about the relationship between personality traits and friendship quality with autistic traits have been mixed. The aim of the current study was to validate the psychometric properties of the original English AQ in a non-clinical Singaporean sample and compare their mean AQ scores to previous Western samples. In this study, psychometric properties of the original English AQ were assessed in 113 Singaporean adults  with no clinical diagnoses. They completed the AQ, the Friendship Questionnaire (FQ) and the short Big Five Inventory, with a subsample completing the AQ twice within three to six months. Results showed that AQ scores were normally distributed and the AQ had satisfactory internal consistency and test-retest reliability and it demonstrated construct, convergent and discriminant validities. Higher AQ scores were related to lower friendship quality and extraversion and higher neuroticism. The mean AQ scores of the Singaporean sample did not differ to that reported in original British sample. Together, present findings showed the original English AQ to be reliable for measuring the degree of autistic traits in a non-clinical Singaporean sample, producing comparable AQ scores and showing the same relationships to other social and personality measures and the same sex differences as has been reported in English samples. This supports the use of the AQ in Singapore for clinical and research purposes and suggests that the measurement of autistic traits in some Asian cultures is comparable to that reported in Western cultures. Autism spectrum disorders (ASD) are characterized by difficulties in social communication and interaction along with restricted interests and repetitive behaviours . AutistiVarious questionnaires have been developed to measure autistic traits in both clinical and non-clinical samples, including the Social Responsiveness Scale (SRS)  and the The AQ was designed as a screening tool to indicate the likelihood of ASD and has become the most widely used measure of autistic traits in non-clinical populations . The oriThe AQ has also been validated in non-clinical samples in Asian countries including Japan, Korea and China, although they have generally used translated versions instead of the original English version –14. The However, other studies have reported cultural differences in the scoring and responses on the AQ between in Asian compared to Western samples, although results to date have been inconsistent to each other. For example, Freeth et al.  found moAdditionally, convergent validity of the AQ has been demonstrated by its relationship with other measures that assess related underlying constructs, including friendship quality and the Big Five personality traits. The AQ and friendship quality assess the same construct of social functioning , 16. CorCritically, no published reports to date have validated any standardised measures of autistic traits in Singapore, so the main aim of this study was to validate the AQ in a non-clinical Singaporean sample and compare the findings with AQ validation studies with Western samples. Singapore is an interesting country because its located in Asia but English is predominantly spoken, presenting a unique opportunity to administer the original English version of the AQ to a non-clinical Asian sample without compromising the selection of a representative sample, unlike many previous Asian studies. This establishes a common basis for comparison with previous Western studies that similarly used the original English version of the AQ. Since ASD diagnoses are less socially accepted in Singapore compared to many Western countries and may be associated with under-diagnosis and underreporting of prevalence rates , validatThe present study aimed to validate the original English version of the AQ in a non-clinical Singaporean sample by testing its internal consistency, test-retest reliability and nature of distribution of scores. Additionally, it aimed to test construct validity by assessing sex differences in autistic traits and convergent and discriminant validities by examining the relationships between friendship quality and personality traits with autistic traits, and to compare mean AQ scores in the Singaporean sample with those from the British sample in the original English AQ validation study. These psychometric properties and analyses were chosen for their precedence in prior Western and Asian AQ validation studies to serve as a basis for comparison to validate the AQ in this new non-clinical sample with similar criteria and enable accurate assessment of the cultural independence of the AQ and autistic traits , 10–14. Mage = 37.78, SD = 14.52; 62Male/ 100Female/ 19 not indicating sex) were recruited in Singapore using social media platforms  and adverts posted in social locations. The inclusion criteria included citizenship or permanent residency in Singapore, speaking fluent English, being 18 years or older, and not reporting any clinical diagnoses. 39 participants had responses below 20% completion, indicating that they did not complete all items on the AQ, thus, were excluded. 25 participants had AQ scores higher than the clinical cut-off of 26 [Mage = 38.35, SD = 14.63; 47M/ 66F) who all indicated a sex whose data were included in the analysis.A total of 181 participants  .The FQ is a 35-item self-report questionnaire which measures the quality of friendships, with an example item being “How easy do you find discussing your feelings with your friends?” Total scores range from zero to 135 with higher scores indicating higher quality friendships. The FQ is reported to have a high Cronbach’s alpha coefficient of .84 in a non-clinical sample .The study received ethical approval from the Psychology Research Ethics Committee (PREC) in the Department of Psychology at the University of Bath, and all participants provided informed written consent. The study was completed online using Qualtrics to present the survey and to record responses, and the order of the survey was the demographic questions, the AQ, the BFI-S and the FQ. To examine test-retest reliability, 41 participants completed the AQ twice, with the second completion being 3 to 6 months after their first completion.D(113) = .06, p = .200.To validate the continuous distribution of AQ scores and determine the nature of the data, normality of AQ scores was tested using the Kolmogorov-Smirnov test. The results indicated a normal distribution in the non-clinical Singaporean sample, d was used to calculate effect size. Lastly, to test convergent and discriminant validities, two multiple linear hierarchical regressions were conducted with AQ scores as the DV. One regression included age and sex as model 1 and personality traits as Model 2, while the other had age and sex as Model 1 and friendship quality as Model 2.Internal consistency for AQ total score was calculated using Cronbach’s alpha. Test-retest reliability was determined by comparing the difference in scores of the first and second AQ attempts using a paired-samples t-test. To test if the AQ was culture independent, an independent samples t-test was conducted on the mean AQ scores of the Singaporean sample in this study and of the British sample from Baron-Cohen and colleagues’  study. TThe results from the reliability analysis showed that the internal consistency of the total AQ was satisfactory and Cronbach’s alpha coefficient was moderate (α = .64).M = 15.43, SD = 4.86) was not significantly different to the mean score reported in the British sample  from the original AQ study by Baron-Cohen and colleagues [t(112) = -0.20, p = .844.The mean AQ score of the Singaporean sample  was significantly higher than that of females , t(111) = 2.43, p = .017, indicating a significant sex difference.The mean AQ score of males  = 3.51, p = 0.033. Sex was the only variable that significantly predicted AQ score  = 6.92, p < .001, and that R2 values for Model 2 were significantly greater than Model 1, R2 = .26, ΔF = 7.84, p < .001, indicating that it explained significantly more of the variance  = 3.51, p = 0.033.  = 4.28, p = .007, and that the R2 value for Model 2 was significantly greater than Model 1, ΔR2 = .04, ΔF = 4.30, p = .041. Regarding individual predictors, friendship quality was found to significantly and negatively predict AQ scores.The results from the second hierarchical linear regression with AQ score as the DV showed that Model 1 significantly predicted AQ score, 033. see . ResultsM = 15.85, SD = 5.23) and second completions  were not significantly different to each other, t(40) = -1.07, p = .290, and were strongly correlated, r(40) = .88, p < .001, indicating satisfactory test-retest reliability. The mean scores of participants who did  and did not  attempt the AQ again were not found to be significantly different, t(111) = -1.10, p = .275, showing that the sample who did the test-retest reliability was comparable to the sample that did not complete it.Results showed that AQ scores for the first  reported in this study relative to previous studies , 13, 14.In conclusion, the findings here demonstrated satisfactory internal consistency, good test-retest reliability, a normal distribution of scores, and construct, convergent and discriminative validity of the English AQ in the Singaporean sample, along with mean AQ scores that were not different to the original British sample. Together, the present results validated the AQ as a reliable measure of autistic traits in a non-clinical Singaporean sample, with both the AQ and autistic traits shown to be robust to cultural differences when compared to the same original English version. This supports the use of the AQ as a screening tool to indicate the likelihood of ASD in adults for clinical purposes and allows for new avenues of research testing the degree of autistic traits in Singaporean samples and potentially other English-speaking Asian samples.S1 Data(CSV)Click here for additional data file.


The systematic review and meta-analysis aimed to comprehensively evaluate acupuncture's efficacy and safety in treating dysphagia in Parkinson's disease (PD).We searched PubMed, Cochrane Library, Embase, Web of Science, China Knowledge Infrastructure (CNKI), China Science Journal Database (VIP), Wan-fang Database, and the China Biomedical Literature Service System (CBM) for randomized controlled trials (RCTs) comparing the efficacy of acupuncture alone or in combination with control treatment in improving dysphagia by October 2022. The degree of dysphagia was the primary outcome indicator, with secondary outcomes including serum albumin (ALB) and hemoglobin (Hb) levels, the incidence of pneumonia, and adverse events. Two investigators independently extracted information according to the inclusion and exclusion criteria. Data synthesis was calculated by RevMan (V.5.4.1) software.P < 0.00001) and reducing Standardized Swallowing Assessment (SSA) scores . Acupuncture combined with control therapy has a more significant benefit in improving the clinical efficiency of dysphagia in PD . Compared to the control group without acupuncture, acupuncture improved the nutritional status of patients and increased their serum ALB  and Hb levels . Three RCTs reported that the rate of pulmonary infections in the acupuncture group was lower than without acupuncture intervention .This study included ten randomized controlled trials with 724 patients. Most RCTs have a high or uncertain risk of bias due to the lack of a blinded design. Meta-analysis showed that acupuncture combined with control treatment was superior to control treatment alone in improving Videofluoroscopic Swallowing Study (VFSS) scores (MD: 1.48; 95% CI: 1.16, 1.81; Acupuncture could be recommended as an adjunctive treatment for dysphagia in PD. However, due to the high risk of bias in the included studies, more high-quality evidence is needed to confirm the efficacy and safety of acupuncture for dysphagia in PD.https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022370221. Dysphagia is a highly associated non-motor symptom of Parkinson's disease (PD), attributed to autonomic and gastrointestinal dysfunction , 2. HoweThe mechanism of dysphagia in PD is unclear and involves both dopaminergic and non-dopaminergic . DopaminAcupuncture is a traditional treatment in China, characterized by simple operation and easy acceptance by patients. The efficacy of acupuncture has been clinically verified, widely used in treating PD worldwide , 26, andhttps://www.crd.york.ac.uk/prospero/.This systematic review was developed based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) and checked by the PRISMA checklist . The metFrom the establishment of the database to October 2022, we searched four English databases  and four Chinese databases . No restrictions on countries or types of articles. The search terms included Parkinson's disease, Parkinson's disorders, deglutition disorders, dysphagia, and acupuncture, and the specific search strategy is shown in According to the PICOS principles, the inclusion criteria for this study were as follows: (1) Participants: Patients with a definite diagnosis of Parkinson's disease and tested for swallowing function, with dysphagia as a clinical manifestation of difficulty eating or choking on water. The diagnostic criteria for PD refer to the Chinese Guidelines for Diagnosis and Treatment of Parkinson's Disease (2016 Revision) and the diagnostic criteria for PD formulated by the Movement Disorder Society in 2015 , 31. TheExclusion criteria were: (1) Previous dysphagia caused by stroke, malignant disease of the posterior pharynx, digestive tract diseases, etc. (2) Studies with unclear diagnostic or assessment criteria. (3) Acupuncture is combined with other Chinese medical methods  to treat dysphagia. (4) The control group used Chinese medicine. (5) Duplicate published studies or studies with incomplete data that remain unavailable after contacting the original author.All included studies were imported into Endnote 20. Two professionally trained reviewers (Jing Wu and Yi Wang) examined all studies separately, excluding duplicate articles and those that did not meet the inclusion criteria and finally identifying studies that met the intended inclusion criteria. After extracting data on authors, year of publication, age, sample size, duration of disease, intervention method, acupuncture points, outcome indicators, and adverse effects, the two reviewers cross-checked to ensure the accuracy of the data. Any disagreements during the screening and data extraction process could be resolved with the assistance of a third assessor (Yu-jia Xie). For literature lacking information, the original authors were contacted for additions.Two reviewers (Jing Wu and Yi Wang) independently performed the risk of bias assessments according to the Cochrane Handbook for Systematic Reviews of Interventions . The evaP-values and 95% confidence intervals (CI). We defined P < 0.05 as a statistically significant difference. When the heterogeneity test is performed, the I2 test is executed first and combined with quantified by the I2 statistic for evaluation. If the heterogeneity test result is I2 < 50%, there is no significant heterogeneity among the results, and the fixed effect model is used for data analysis. If I2 ≥ 50%, there is statistical heterogeneity among the results. After excluding apparent clinical and methodological heterogeneity, the random effect model was used for meta-analysis.RevMan 5.4.1 provided by Cochrane Collaboration was used for data analysis. Relative risk (RR) was chosen as the statistic for dichotomous data, and mean difference (MD) as the effect indicator for continuous variables to obtain P-values ≥ 0.05 for the interaction indicated that the treatment effect did not differ significantly between subgroups. Sensitivity analysis was conducted when necessary.We considered that different types of acupuncture may have influenced the effectiveness of acupuncture, so we performed a subgroup analysis of the efficiency of varying needle types for treating dysphagia in PD. We searched a total of 171 papers from electronic databases. After excluding duplicate studies, 117 relevant studies were screened out. After reading the titles and abstracts of these studies, 24 relevant studies were identified. We read the full text before two independent reviewers performed further eligibility screening based on inclusion and exclusion criteria. The final 10 studies were included in the meta-analysis. The detailed literature screening process is shown in The 10 articles included in this study were all single-center randomized controlled trials conducted in China with 724 patients  , 33–41. Among the 10 included studies, warming acupuncture was used in two studies , 36, eleWe assessed the risk of bias for all included articles. Two studies , 36 did P = 0.38, I2 = 0%), and the fixed-effects model showed a meaningful difference in VFSS scores between acupuncture combined with rehabilitation training (RT) and RT alone , indicating that acupuncture assisted treatment can significantly improve dysphagia in patients with PD, as shown in Five studies reported post-treatment VFSS scores , 39, 41,P = 0.65, I2 = 0%), fixed-effects models were used for analysis. The results showed that swallowing function was better in the acupuncture-treated group compared with the control group without acupuncture . See SSA scores were reported in three studies –41. SincP = 0.58, I2 = 0%). The results showed that patients who received acupuncture combined with RT had more improvement in swallowing function compared with RT alone , the improvement of swallowing function was divided into four grades in six studies –37, 40, P < 0.0001; heterogeneity: I2 = 23%, P = 0.26), prick bleeding plus rehabilitation  and thumbtack needle plus RT  both significantly enhanced the effective rate.We divided the included studies into two subgroups according to the type of acupuncture to discuss the efficacy of acupuncture due to the variety of acupuncture methods in the experimental group. As shown in P < 0.00001; heterogeneity: I2 = 82%, P = 0.004; P < 0.00001;f heterogeneity: I2 = 17%, P = 0.30; The three included studies , 34, 35 P = 0.001; heterogeneity: I2 = 0%, P = 0.40; The incidence of pulmonary infection is reported in three articles , 36, 41.Of the ten included studies, only one reported no related acupuncture adverse events during the trial , and theFunnel plots were not used to investigate publication bias because of the limited number of included studies .This systematic review included 10 RCTs that evaluated the patient's swallowing function, nutritional status, and incidence of pneumonia. Our study showed that acupuncture combined with rehabilitation training increased the effectiveness of improving swallowing function in patients with swallowing disorders in Parkinson's disease and could lead to significant improvement in the patient's swallowing function and reduced the incidence of pulmonary infections. In addition, patients with dysphagia are often accompanied by malnutrition, and the nutritional level is closely related to the prognosis of patients. The study on the correlation between dysphagia and the nutritional status of PD patients shows that the better the nutritional status of patients, the better the prognosis . ALB andThe Water Swallow Test and VFSS are commonly used clinical assessment methods of dysphagia, among which VFSS is recognized as the gold standard for the diagnosis of dysphagia . HoweverDysphagia is a serious adverse factor in the prognosis of PD patients and a significant cause of death . It has “Where the acupoints are located, the indications are located” is one of the roles of acupoints. The ability of an acupoint to treat diseases in its location and the adjacent organs, tissues, and organs is a common feature of all acupoints . This arOverall, this study is the first systematic evaluation and meta-analysis of the effectiveness and safety of acupuncture for Parkinson's swallowing disorder. We hope to provide doctors with a range of treatment strategies and help them design individualized interventions. According to the above results, doctors can develop the most appropriate approach for dysphagia in PD based on proximal acupoint selection and Syndrome differentiation, combined with the proper acupuncture method.Although this study followed the criteria stated in PRISMA, there are still some limitations. First, even though the meta-analysis shows no obvious heterogeneity, all the included studies are single-center RCTs in China, and the small sample size and the diversity of treatment methods may lead to certain potential biases, thus affecting the reliability of the results. Second, due to the specific nature of acupuncture therapy, studies are difficult to implement, blinding for participants and personnel, and there is a high risk of bias. Third, as only one of the included studies mentioned the absence of adverse effects and none of the other studies reported on the adverse effects of acupuncture, there was no systematic review of the possible acupuncture problems during treatment. Hence, to more comprehensively and objectively evaluate the efficacy of acupuncture in treating dysphagia in Parkinson's disease, future studies need to raise the sample size, provide reasonable allocation concealment and blinded design for trials, and provide more comprehensive reference information for subsequent research studies.Acupuncture is effective as a complementary therapy for dysphagia in PD, not only improving patients' swallowing function but also enhancing their nutritional status and reducing the incidence of pneumonia. However, due to the high risk of bias in the included studies, the results should be interpreted with caution, and multicenter, more rigorous, and high-quality RCTs are necessary for subsequent analyses.The original contributions presented in the study are included in the article/JW and XW selected a topic for the study. WL revised the manuscript. JW and YW conducted data extraction and quality assessment, completed the data synthesis, drafted the manuscript, and performed the search strategy. YX arbitrated in cases of disagreement and ensured the absence of errors. All authors have developed the search strategy, read, and approved the manuscript.


The study aimed to compare the evolution of patient safety culture perceived by high-risk hospital staff in the context of the COVID-19 pandemic and non-COVID-19 pandemic and to examine the variations in patient safety culture across demographic variables. The study found that the COVID-19 pandemic has significantly impacted patient safety culture in healthcare settings, with an increased focus on safety climate, job satisfaction, teamwork climate, stress recognition, and emotional exhaustion. Safety culture and work stress vary among medical professionals of different age groups. To reduce stress, workload should be minimized, work efficiency improved, and physical and mental health promoted. Strengthening safety culture can reduce work-related stress, improve job satisfaction, and increase dedication towards work. The study recommends interventions such as psychological and social support, along with emotional management training, to reduce emotional exhaustion. Healthcare institutions can set up psychological counseling hotlines or support groups to help medical professionals reduce stress and emotional burden. Patient safety culture refers to employees’ shared beliefs, attitudes, values, norms, and behavioral characteristics regarding patient safety and is considered an important component of hospital culture that is oriented towards patient safety , 2. StudDuring the COVID-19 pandemic, patient safety culture in high-risk units of hospitals has become particularly important. These high-risk units, such as intensive care units (ICU), emergency departments (ED), and operating rooms, are where medical personnel and patients are most vulnerable to infection. In general, medical professionals in high-risk units need to face various complex surgeries, treatments, and monitoring. If they lack proper preventive measures and protection awareness, it will increase the risk of COVID-19 infection (such as airborne and fluid transmission) and medical errors. Establishing a patient safety culture can improve medical professionals’ awareness of disease control and infection prevention, thereby improving the quality of medical services and further enhancing patient safety. However, few studies have explored the changes in patient safety culture among high-risk hospital staff that have occurred before and after the COVID-19 pandemic  has been designated as the official questionnaire for evaluating patient safety culture since 2008. As per the current medical system in Taiwan, both the survey outcomes and the primary dataset need to be submitted electronically to the Joint Commission of Taiwan (JCT) via their website. Medical professionals (physicians and nurses) working in high-risk hospital environment  in 2019 and 2020 were issued to compare the trends of patient safety culture in the period of COVID-19 and non-COVID-19 pandemic. The ICU at case hospital plays a pivotal role in managing critically ill patients, particularly during the COVID-19 pandemic. It encompasses comprehensive medical care, advanced life support, continuous monitoring, infection prevention and control, rigorous diagnostic and therapeutic interventions, and multidisciplinary collaboration, including departments of internal medicine, pediatrics, and respiratory medicine. Moreover, the ED case hospital also plays a critical role in managing urgent and emergent medical conditions, especially during the COVID-19 pandemic. It involves rapid triage, timely assessment and stabilization of patients, implementation of infection control measures, efficient diagnostic evaluation, and coordinated multidisciplinary care. The ICU had 72 medical professionals, while the ED had 41.Medical professionals were asked to complete the questionnaire electronically through an email-delivered hyperlink. In the event that medical professionals lacked email addresses, a distinct account and password were supplied in hard copy format to enable access to the online questionnaire. Certain personnel opted for the paper-based format, whereby completed questionnaires were submitted to a dedicated box. All questionnaires were anonymized, devoid of any personally identifiable information.2.3.α values which ranged from 0.800 to 0.964.The study utilized the CSAQ to assess medical professionals’ perceptions on patient safety in high-risk hospital environment; the tool was translated from Dr. Sexton’s SAQ by the JCT in 2007 , 9. It o2.4.t-tests to examine the relationship between demographic and professional variables and the CSAQ dimensions. Additionally, Pearson’s coefficient (r) was used to identify any correlations between each of the CSAQ dimensions.The data was managed and analyzed using SPSSv25. Descriptive statistics such as means, standard deviations, frequencies, and percentages were calculated. Bivariate analysis was conducted using one-way ANOVA and 3.3.1.In both 2019 and 2020, a total of 113 questionnaires were distributed to the medical professionals in high-risk hospital environment. Out of these, 106 valid questionnaires were collected in 2019, resulting in a response rate of approximately 93.80%. In 2020, 102 valid questionnaires were collected, yielding a response rate of approximately 90.27%. To ensure consistency and comparability of the analysis results, this study employed a sample of 102 respondents for data analysis. The majority of participants in both 2019 and 2020 were female, accounting for 86.3% and 70.6% respectively, and most of them were nurses. Additionally, the majority of respondents were between the ages of 21 and 30, with 55.9% in 2019 and 66.7% in 2020 falling within this age range. The proportion of supervisors among respondents increased from 3.9% in 2019 to 8.8% in 2020. Furthermore, the results of both 2019 and 2020 indicated that most of the respondents had a college degree or above, with 95.1% and 96.1%, respectively, holding this level of education. In terms of work experience, nearly half of the respondents (about 47%) reported having worked for more than 5 years. Additionally, respondents in both years reported frequently needing to contact patients, with 91.1% in 2019 and 92.2% in 2020 indicating that this was a regular part of their job duties.Overall, the majority of participants in both years were female, with nurses comprising the largest group. Additionally, a significant proportion of respondents fell within the 21–30 age range. The number of supervisors among the respondents increased from 2019 to 2020. Most of the participants held a college degree or above. Nearly half of the respondents reported having more than five years of work experience. Moreover, contacting patients was identified as a regular aspect of their job duties for the respondents in both years. These findings highlight the demographic characteristics, educational background, work experience, and job responsibilities of the healthcare professionals surveyed in this study.3.2.p > 0.05), except for the mean EE score. The mean EE score in 2020 was significantly higher than that in 2019 (p < 0.05).The 2019 results of the statistical analysis demonstrated that TC  has the highest mean value, whereas WLB  has the lowest average value. The results of 2020 demonstrated that TC had the highest average value of 3.63, while WLB had the lowest mean value of 2.69. The Cronbach’s alpha values for the 2019 and 2020 CSAQ dimensions were ranged from 0.800 to 0.947. As shown in 3.3.3.4.To understand the factors affecting the respondents’ perceptions of patient safety culture in 2019 and 2020, a bivariate analysis including demographic and the CSAQ dimensions was conducted see , 5. TherBased on the results of an independent sample t-test, it was found that the mean scores for the dimensions of the CSAQ in TC, JS, SR, PM, and WC were significantly higher for males compared to females in 2019. However, there was no significant effect of gender on any of the CSAQ dimensions in 2020.There are differences in the perceptions of the patient safety culture among medical personnel with varying levels of work experience. The data from 2019 demonstrated that the mean JS score of medical personnel with 1–11 months of experience in the organization was significantly higher than that of those with 3–4 years of experience. In 2020, the mean JS and WC score for the above 21 years of experience in the organization was significantly higher than that of the 3–4 years, and the mean EE score for the above 21 years was significantly higher than that of the 1–2 years.Medical personnel who hold managerial positions have a significantly higher mean score in TC, SC, JS, PM, and WC compared to those who do not hold managerial positions in both 2019 and 2020. According to the data from 2020, medical personnel who hold managerial positions have a significantly higher score in EE than those who do not hold such positions. Educational level and whether they have contact with patients at work did not affect the CSAQ dimension score.4.This study fills gaps in the existing literature by focusing specifically on healthcare professionals working in high-risk hospital environments such as intensive care units and emergency rooms, this study narrows down the scope of research to a specific subset of medical personnel. This targeted approach helps to provide more precise insights into the patient safety culture within these critical units. Furthermore, the study’s emphasis on physicians and nurses as the primary participants the COVID-19 and non-COVID-19 contexts adds to the existing literature by shedding light on the specific experiences and perceptions of this healthcare professional group, which is valuable in understanding the dynamics of patient safety culture during the pandemic.It is worth noting that our results show that there may be some differences in patient safety culture between COVID-19 and non-COVID-19 pandemic. It is important to carefully interpret these results and consider factors that may affect patient safety culture, such as age, experience in organization, and managerial position. First, our research findings indicate that during the pandemic, both safety culture and work stress are crucial issues for medical professionals. There are significant differences in safety culture and stress perception among medical professionals of different age groups. The results of this research are consistent with the findings of Preti et al. , who repNext, strengthening the cultivation of safety culture can enhance the awareness of medical professionals and reduce work-related stress. The results of our research align with the findings of Chen et al. , who higThird, improving the job satisfaction of medical professionals during the pandemic is also a worthy issue of concern. Similarly, Rana et al.  found thFourth, this study demonstrates that medical professionals in managerial positions perform better in terms of patient safety culture than those in non-managerial positions. We recommend that it is important to clearly authorize medical professionals with their responsibilities and accountabilities in patient safety, ensuring that they understand their role and responsibility in patient safety. This includes ensuring that they know how to detect and report adverse events, identify and manage potential risk factors, and promote and implement best practices in patient safety. Encouraging medical professionals in managerial positions to participate in patient safety work and providing rewards and incentives for outstanding employees can be beneficial. This may include recognizing excellent employees, providing training and promotion opportunities, etc. This can help motivate medical professionals to invest more time and energy into improving patient safety.Finally, research data from 2019 and 2020 also shows a significant negative correlation between EE and most dimensions of the CSAQ, except for stress cognition. EE represents the phenomenon where individuals gradually lose their ability to express positive emotions and experience fatigue, weariness, and negative emotional states such as depression, as a result of prolonged work pressure, psychological burden, and emotional communication . EE amon5.In the context of the COVID-19 pandemic, there have been significant changes in patient safety culture. The pandemic has brought new challenges and risks to healthcare settings, leading to increased emphasis on infection control, communication, and teamwork. Healthcare organizations have had to rapidly adapt to the constantly changing environment, which has impacted patient safety culture.Emotional issues of medical professionals during the pandemic are often overlooked or deemed unimportant. It is worth noting that the effects of emotional conditions on medical professionals can be long-lasting and can have a significant impact on both their physical and mental health. These issues can also interfere with their job performance, potentially compromising patient safety. Within demographic structures, patient safety culture may vary between the COVID-19 and non-COVID-19 contexts. Factors such as the age, years of experience, managerial position and may also impact changes in patient safety culture in response to the pandemic.A number of recommendations for future research are given. Further studies in different hospital settings and countries are suggested to confirm the findings of this study and determine if similar changes in patient safety culture have occurred in other healthcare systems. Conducting longitudinal studies to track the changes in patient safety culture over time during pandemics. This will help in evaluating the effectiveness of interventions aimed at improving patient safety culture and identifying areas for further improvement. Moreover, qualitative research could be conducted to gain a deeper understanding of the experiences of healthcare staff during pandemics and how they perceive patient safety culture. This will help in identifying the barriers and facilitators to improving patient safety culture in pandemics.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.This Study received ethical clearance from the Institutional Review Board of Cheng Ching General Hospital in Taichung City, Taiwan with approval number HP190028. The participation in the study implies consent for the use of the data.H-CH and W-HH conceived and designed the study and draw the manuscript. L-YC collected data and H-CH and L-YC analyzed the data. All authors contributed to the article and approved the submitted version.This work was supported by Hubei Provincial Department of Education with the grant number of B2022137, Hubei Enterprise Culture Research Center, and Research Center of Hubei Logistics Development.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Monosodium glutamate (MSG) is the sodium salt of glutamic acid (GLA), used as a flavour enhancer. MSG is considered a controversial substance. It is incriminated in disturbing the antioxidant system, but also has beneficial effects, as GLA metabolism plays a crucial role in homeostasis. This study highlights which positive or negative aspects of MSG sub-chronic consumption are better reflected in subjects potentially affected by advanced age. Daily doses of MSG were administered to four groups of two-year-old Wistar rats for 90 days: (I) 185 mg/kg bw, (II) 1500 mg/kg bw, (III) 3000 mg/kg bw and (IV) 6000 mg/kg bw, compared to a MSG non-consumer group. Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, direct and total bilirubin, total cholesterol, triglycerides, creatinine and urea levels were analysed; stomach, liver and kidney samples were subjected to histopathological analysis. Although, in most cases, there were no statistical differences, interesting aspects of the dose–effect relationship were observed. After MSG sub-chronic consumption, the positive aspects of GLA seem to be reflected better than the negative ones. The hormesis effect, with low-level reactive oxygen species’ protective effects and GLA metabolism, may represent the hypothesis of a potential defence mechanism triggered by MSG sub-chronic consumption in ageing rats. Corynebacterium [Glutamic acid (GLA) is a non-essential amino acid found in animal and plant proteins . It is aacterium ,5. The uacterium . There iacterium . Only a acterium ,7. We practerium .In 1995, MSG was included in the Generally Recognised As Safe (GRAS) list by the Food and Drug Administration (FDA) ,6. Also,Although food safety regulatory agencies generally consider MSG consumption safe, there are two aspects regarding its safety as a food additive. On one side, using GLA and its salts as food additives makes a small contribution to the total glutamate intake from all sources . Also, iBecause MSG follows the same path of processing as GLA by the human organism, some essential metabolic roles of the amino acid highlight their beneficial effect. Firstly, GLA is involved in liver detoxification because of its capacity to fix the ammonia in case of acute liver failure. Physiologically, intestinal ammonia, produced from nitrogen products, is taken up by the liver and subjected to the ureogenetic cycle. Damaged livers, instead, do not accomplish this step efficiently, resulting in high ammonia levels. The glutamine (GLN)/glutamate cycle and glutamine synthetase (GS) are very important in the process of ammonia detoxification, as GLN is the non-toxic storage and transport form of ammonia in the liver . The enzThe GLA–GLN relationship also plays a vital role in muscular metabolism, as GLN is stored and released predominantly by the skeletal muscle . Also, iIn addition to being the major nitrogen transporter, GLN is also a regulator of acid–base balance . Kidney-N-methyl-D-aspartate) receptors of glutamate are considered to be of great importance for the learning process. They seem to have a crucial role in encoding. NMDA receptors are involved in the emotional memory, the procedural memory system, motor learning and episodic-like memory [Additionally, the contribution of GLA to synaptic transmission, neuronal plasticity, development, learning and memory is well established . In conte memory . In addie memory .On the other hand, despite GLA metabolic implications and beneficial effects, many researchers disagree with the safety of MSG consumption. The potential toxicity of MSG has been evaluated mainly through preclinical studies. The reported side effects of MSG included (but were not limited to) hepatotoxicity, nephrotoxicity, reproductive system toxicity, cardiotoxicity, neurotoxicity ,29,30,31Terminalia catappa extract, propolis and protocatechuic acid [Oxidative stress is considered the primary mechanism for many disorders caused by MSG . An imbauic acid ,40,41,42uic acid . Therefore, questions can be raised about the consumer’s dangerous and unconscious abuse of MSG. The reason is the difficulty of monitoring the amount of ingested substance, which is likely responsible for effects at multiple histological levels in chronic and sub-chronic consumption, even in small doses. The scientific literature provides us with several experimental studies that have assessed the chronic toxicity of MSG but with significant heterogeneity in the administered doses and the period of administration. Most preclinical studies evaluate MSG chronic and sub-chronic toxicity at different tissue levels through biochemical and/or histological determinations .Therefore, this experimental study aims for a more comprehensive knowledge of MSG’s pharmaco-toxicological profile, considering its abusive and uncontrolled use in food. As presented before, arguments exist for and against its behaviour in the organism. This study emphasises which positive or negative aspects of MSG sub-chronic consumption are better highlighted in subjects potentially affected by advanced age; this aspect involves observing how they are influenced by the ADI and NOAEL dose of MSG, established by the scientific literature. Thus, the study goal is to provide relevant data regarding the effect of MSG through biochemical and histological methods  applied to an ageing experimental animal model (two-year-old Wistar rat).The study proposal was approved by the George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures Scientific Research Ethics Committee (No. 1172/05.11.2020) and Targu Mures Sanitary-Veterinary and Food Safety Direction (No. 49/02.07.2021).Anhydrous MSG was obtained from Sigma Aldrich . The producer guaranteed 99% purity.The study was conducted on seventy 2-year-old Wistar adult rats . They were obtained from the Biobase of UMFST George Emil Palade of Targu Mures. The animals were raised under standard laboratory conditions: comfort temperature 21–22 °C, humidity 40–60%, 12 h/12 h dark–light cycle. The animals were divided into five groups of 14 rats each . The animals were fed with standard fodder for rats purchased from “Cantacuzino” National Institute for Medical-Military Research and Development from Bucharest. The MSG was included in the feed composition, and the mixture was homogenised and pelleted. The administration of the MSG to the subjects was carried out under identical conditions for 90 days.The pellets and water were administered ad libitum, as this feeding method is often used for rodents in animal experiments and is considered a stress-free administration route. Additionally, as in the human population MSG is administered orally, we considered it more relevant for the study to choose this route to simulate human behaviour as correctly as possible. The administered amounts were established considering the quantities allowed by the food safety authorities (ADI and NOAEL doses according to EFSA) since the ones used in similar studies are very different. The MSG doses per group and pertinent observations are presented in Human/animal and animal/human dose extrapolation were set after Reagan-Shaw S. et al.  and AnroThe groups were monitored daily regarding their behaviour and experimental conditions. Also, the rats were weighed, and the food and water consumed were monitored weekly.After 90 days of MSG administration, the animals were sacrificed (following an 18 h fast) to collect the biological samples—blood samples (blood serum) and histological samples. The blood samples were used to determine the levels of several biochemical and metabolic parameters: aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin (TB) and direct bilirubin (DB), urea (UR), creatinine (CR), triglycerides (TG) and total cholesterol (CHOL). Moreover, liver, renal and stomach tissues were collected for anatomopathological analysis.Application of anaesthesia. The blood samples were collected through cardiac puncture under general gaseous anaesthesia using isoflurane. The exsanguination allowed the collection of a high amount of blood to analyse all the proposed biochemical parameters. Sampling and storage of blood samples. The blood samples were collected using a 10 mL or 20 mL syringe. They were collected in 6 mL yellow vacuum blood sample collection tubes (Gel and Clot activator) for optimal separation of blood serum. Then, the samples were kept for 30 to 50 min to rest at room temperature. Further, they were centrifuged for 5 min at 3000 rotations/min, using 5804 R Eppendorf and 5810 Eppendorf centrifuges. After centrifugation, the serum was separated from the other components using an automatic micropipette and stored in safe-lock Eppendorf tubes at −80 °C.The analysis of biochemical and metabolic parameters. The analysis of the parameters was made with Cobas Integra 400 Plus apparatus. The kits were compatible with the analyser and were purchased from Roche Diagnostics. The parameters were analysed with specific methods and reagents .Sampling and storage of the tissue samples. The liver, kidneys and stomach were collected, rinsed and conserved in a 10% neutral buffered formalin (NBF). A particular procedure was applied to the stomach, which was rinsed with 9% NaCl solution and left on a Petri dish covered with 10% NBF for 30 min. After that, the tissue was conserved in a 10% NBF. After 24 h, the solution was changed for all the samples. Then, the tissue samples were subjected to grossing and inclusion in histological cassettes. The tissue samples were processed following a standard histological protocol and embedded in paraffin. After this, thin sections of 2 µm were obtained from the paraffin blocks using the rotary microtome. They were later stained using Haematoxylin–Eosine (H&E), according to a routine protocol.Histological analysis. Histological samples were examined under an Olympus BX51 microscope, and the bright field images were obtained with an Olympus SP350 digital camera and processed using the Olympus cellSens software (Version 3.1). Histologic changes were assessed and graded as to severity utilising the International Harmonization of Nomenclature and Diagnostic (INHAND) standards ,53,54. Tp < 0.05. The data were collected and stored with the help of Microsoft Excel (Microsoft Office™) software (Office 365). The statistical tests were performed in Graphpad PRISM 9 (Graphpad™). All quantitative data underwent the ROUT (Q = 1%) outlier identifier test. The normality distribution was tested with the D’Agostino and Pearson test. To determine whether the experimental groups had any statistical differences regarding the biochemical and metabolic parameters and chronic progressive nephropathy severity, the one-way ANOVA test and post-hoc Dunnett’s and Tukey’s tests were used for statistical analysis. Data are expressed as mean values ± SD. All statistical tests were performed at a 95% confidence interval. Statistical significance was established, being indicated by In the case of histopathological data, no statistical tests were applied. The results are expressed as the occurrence frequency of modification/group. No statistical differences were observed between the groups for the AST parameter. The highest values for AST were observed in the Control group, followed by group 2. For ALT, the highest values were found in group 3; a decrease in values of ALT from group 3 to group 4 was observed, with a statistically significant difference .In the present study, group 4 presents the lowest values of ALP. Group 1 shows the highest values, followed by the Control group. Statistical differences were observed between group 1 and group 4 and also between the Control group and group 4 .The highest values of DB and TB were observed in group 2. A decrease in the values of DB (slightly decrease) and TB from the Control group to group 1 was noticed. Also, a decrease of TB (slightly decrease) and DB from group 2 to groups 3 and 4 was observed ; there aThe maximum CHOL value was measured in group 4, which received the highest dose, twice the NOAEL-approved one. The differences between the groups were not statistically relevant regarding CHOL levels. Group 2 had similar values to the Control group. Group 3 presented the lowest values compared to the rest .TG levels increased from group 1 to group 4; the last one showed the highest values among all five groups. Groups 1, 2 and 3, on the other hand, showed lower values than those of the Control group . The Control group and groups 1 to 3 presented similar values of CR. The highest values were those of group 4; a statistical difference was observed between the Control group and group 4 .The measured values of UR were quite similar for all groups; the highest value was observed in group 3 .The histological changes observed in the hepatic tissue are presented in The histological changes of the renal tissue are also presented as the occurrence frequency of lesions for each group. Hyaline droplet accumulation, tubular pigment, mineralisation, chronic progressive nephropathy, glomerulopathy and cytoplasmic vacuolisation are the histopathological changes observed among the subjects. .As a characteristic of CPN, glomerulopathy was observed in all groups, as follows: Control group—25.00% (3/12); group 1—20.00% (2/10); group 2—33.33% (3/9); group 3—57.14% (4/7); group 4—41.66% (5/12).Also, a grading of chronic progressive nephropathy was performed to assess the severity of the alteration. No statistical differences were observed between the groups’ grades after applying the one-way ANOVA and post-hoc Dunnett’s and Tukey’s tests . Throughout the experiment, some subjects from each group died before the end of the administration of the entire amount of MSG. The mortality rate increased from the Control group to group 3, with a subsequent decrease in group 4  .AST and ALT are indicators of hepatocyte integrity, an increase in the serum levels of the two enzymes suggesting the destruction of the cytoplasmic or mitochondrial membranes. Increased release of the liver enzymes AST and ALT indicates hepatocellular damage in mammals. For rodents, AST shows greater specificity for liver damage . AST and ALT are transaminases that can transform glutamate into α-ketoglutarate (α-KG). Once in the intestine, exogenous glutamate undergoes this transformation catalysed by AST and ALT in the intestinal enterocytes. The final product is carbon dioxide after participating in this way in the Krebs cycle. However, glutamate metabolism also yields glutamine, aspartate or alanine ,56.Various scientific studies present MSG as responsible for destroying liver cells by producing an imbalance between the body’s oxidising and antioxidant species. The explanation could be some disturbances in the levels of CAT and SOD or the decrease in the level of GSH in the case of high consumption of MSG ,42,56,57Scientific studies that evaluated the toxicity of MSG show relatively significant heterogeneity in terms of the administration period and the administered dose. In most studies, the administration was performed orally with the feed or by gavage. Studies conducted on young adult rats concluded that different amounts of MSG are responsible for increasing AST and ALT levels. Also, in studies with multiple doses, the increase of AST and ALT was directly proportional to the administered dose. MSG had been given in different amounts and for different periods and in each case, the AST and ALT levels were higher than the Control group: 0.69 mg/g bw/day and 1.38 mg/g bw/day, respectively, administered for 28 days ; 1.8 mg/In our study, compared with the findings of the studies mentioned above, the values of AST and ALT are not proportional to the administered dose. We observed a decrease in values from group 3 to group 4 for ALT. Although the quantities of MSG administered in our study are much higher than in other studies, there are no statistical differences between the groups, except groups 3 and 4, for the ALT parameter.The relevance of the clinical value of serum ALP lies in diagnosing cholestatic liver, with hepatobiliary obstruction being a pathological condition in which it is increased ,64. GiveSeveral experimental studies on rats presented MSG as the responsible molecule for increased levels of ALP. An increase in ALP levels compared to the Control group was observed, even if there was a difference in the administered dose and the period of administration, such as: 2.4 g/kg bw/day, 8 weeks ; 35 mg/kIn our study, group 4 (6 g MSG/kg bw/day) presented the lowest ALP values compared to group 1 (185 mg MSG/bw/day), the differences being statistically significant. Also, statistical differences exist between group 4 and the Control group. The obtained results contrast with the Johnlouis I. et al. (2019) experimental results, where an increase in ALP levels, compared to the Control group, was observed at 8 g MSG/kg bw/day after 14 days of administration . The samSerum bilirubin concentration can be used to indicate liver functional status and differentiate several types of liver damage . An incrOnobrudu D. et al. (2020)  and AiraCHOL and TG are good indicators for the changes in the serum lipid profile following sub-chronic consumption of MSG. Elevated levels of CHOL indicate the onset of atherosclerotic processes, kidney damage or the development of diabetes. Low levels, on the other hand, may suggest liver damage . MSG is According to the scientific experimental studies on animals that assessed the influence of CHOL according to the dose of MSG, an increase in CHOL levels was predominantly observed compared to MSG non-consuming groups. The values were also directly proportional to the increase in the quantity of the additive. So, starting from the thorough analysis of the experimental studies and considering the metabolic implications of MSG, the expectations regarding CHOL levels were that they would increase depending on the dose of the additive. Several studies present higher levels of CHOL after MSG administration, as follows: 15 mg/kg bw/day, administered for 30 days ; 0.69 mgAnother study in which 10 mg/100 g bw/day MSG was administered to adult rabbits for 21, 42 and 63 days indicated lower levels of CHOL compared to the Control group in each case . In our TG characterises the body’s lipid profile, with high TG values indicating acute pancreatitis, liver and kidney damage or diabetes. An increase in TG can also be produced by exogenous substances ,70,80. TA possible dysregulation of the carbohydrate metabolism, manifested by insufficient insulin levels, can lead to increased lipolysis, with high production of fatty acids, possibly due to elevated levels of oxidative species. The esterification of fatty acids leads to TG, increasing lipid reserves in the liver and muscles . ConsequIn our study, the levels of TG increased as the MSG dose was higher, except in the Control group, which had the highest values after group 4. Although no statistical differences were observed, the group that received 6000 mg/kg bw/day presented the highest values of TG and CHOL, the parameters contouring the lipid profile of the subjects. Several experimental studies quantified the levels of TG after administration of different doses of MSG to groups of adult rats. Most of them observed increased levels of TG compared to the Control group: 2.4 g/kg bw/day, administered for 8 weeks ; 600 mg/Regarding renal damage, CR and UR are two suggestive parameters for evaluating possible changes at this level . Since CAccording to scientific literature, MSG’s nephrotoxic effect is achieved through multiple mechanisms. Among these is the formation of free radicals at the renal level, considered a primary cause of the destruction at the cellular level . The kidUR is a biological compound with a crucial role in the body, as its synthesis contributes to the decrease of ammonia levels resulting from the catabolism of amino acids. Thus, the amount of this parameter is influenced by protein consumption. The detoxification process takes place through the biochemical reactions of the UR cycle ,67,80,84The specialised literature presents MSG as responsible for the dysregulation of tubular resorption, glomerular filtration rate and renal blood flow. All these factors can be causes of nephrotoxicity. These alterations result from oxidative stress production at this level . The impIn our study, CR levels do not present significant differences between the Control group and groups 1–3, with similar values. However, group 4 is distinguished, having the highest levels, with statistical differences compared to the Control group. Other experimental studies on adult rats support the idea that higher values of CR appear in the experimental group, compared to the Control one, when the following doses of MSG are administered as 3 g/kg bw/day for six months , and 15 Also, several studies assessed the levels of CR an UR. They observed increased levels of both parameters compared to the Control group when administering MSG: 15 mg/kg bw/day, for 30 days ; the dosRegarding UR levels, in the present study, we have similar values for the Control group, groups 1 and 4, while group 3 presents the highest levels. The decreasing trend of values from group 3 to group 4 is also repeated for the UR, ALT, DB, TB and ALP parameters. Our hypothesis for this effect could sustain the body’s possible compensatory mechanisms. As we analysed the biochemical parameters, particularly valuable for liver and kidney function, we intended to complete the results with an anatomopathological evaluation of the hepatic and renal tissues. Also, as MSG was given orally, the stomach was subjected to anatomopathological analysis.Bile duct hyperplasia is considered to be a common background finding, being a spontaneous change in older animals, but it can also be induced or exacerbated by the treatment ,85,86. MHelicobacter hepaticus and Helicobacter bilis [Minimal oval cell hyperplasia was observed in the Control group and group 3, the experimental group having the highest values. Also, group 3 was the only group that presented moderate oval cell hyperplasia. Bile duct hyperplasia may be associated with oval cell hyperplasia . Oval ceer bilis ,87.Minimal and moderate, mainly portal, multifocal mononuclear cell infiltrate was observed in all groups of our experiment. They are generally noticed in several chronic liver diseases of various aetiologies . RegardiIn our study, hepatic macrovesicular and microvesicular steatosis (mainly centrilobular) was observed only in the control group, while from group 2 to group 4, increasing percentages of minimal hepatic focal microvesicular steatosis were noticed. It can also be considered a physiological adaptation to an imbalance between the uptake of lipids from blood and the secretion of lipoproteins by the hepatocyte . NitrofuAlthough many cases of cholangiocarcinoma are not related to a specific risk factor, primary hepatobiliary disease, genetic disorders, toxic exposures and infections could contribute to its development . CholangHelicobacter spp. [The karyomegaly observed in group 4 occurs because of duplication of nuclear material in the absence of cytokinesis, reflecting hepatocyte polyploidy. Ageing rats of different strains have a predisposition to variations in cell size, nuclei and polyploidy ,91. Modeter spp. . In our ter spp. .Scientific studies evaluating MSG toxicity on liver tissue reported several histological modifications following MSG administration, compared to the Control group, as follows: periportal hepatic necrosis associated with mononuclear cell infiltration and single-cell necrosis  ; moderatHyaline droplets represent low molecular weight protein accumulation within lysosomes caused by tubular reabsorption and hydrolysis balance disturbance. The reason for this imbalance is increased filtered protein loads or decreased catabolism . HyalineMineralisation can occur spontaneously in laboratory animals or as a consequence of drug treatment. It is frequently observed in rodent toxicity studies. Mineralisation can also be a consequence of renal failure. More commonly, renal mineralization is found as a spontaneous lesion along the corticomedullary junction in rats as a background finding and is of no clinical consequence. Among rodents, female rats show a higher predisposition . This moCytoplasmic vacuolisation is characterised by intracellular accumulation of fluid, lipid, or other material within the epithelium. This results in a swollen, pale or granular cytoplasmic appearance. Although it may precede degeneration and necrosis, cytoplasmic vacuolisation may also indicate a reversible change or occur in normal animals . Group 4In our study, as CPN occurred in all groups, we attempted to grade it to evaluate if there is a correlation between its severity and MSG dose. Although there are no statistical differences between groups, we noticed a trend of increasing severity grade from the Control group to group 3, with a subsequent decrease of values in group 4.CPN is a common, spontaneous, age-related disease of rodent kidneys, particularly in rats . The distert-butyl alcohol, ethyl benzene and tetrafluoroethylene.Furthermore, the disease appears more severe in male than female rats. In addition to strain, age and sex differences, hormones, diet and microflora are other factors that can modulate the incidence and severity of CPN-associated lesions ,97. A poSerum urea nitrogen and creatinine levels are not significantly elevated until the advanced stages of the disease. Advanced CPN is a significant factor underlying the spontaneous development of atypical tubule hyperplasia .Some of the renal histological alterations following MSG consumption observed in experimental studies on rats and mice, compared to the Control group, are presented as follows: vascular congestion, interstitial inflammatory infiltrate, hyaline casts and cellular casts in the renal tubules  ; dilatatNo histological alterations were observed among the subjects after stomach evaluation.Polyuria and polydipsia were noted to be more pronounced with increasing MSG dose, but in the case of group 4, they were very marked compared to the other groups. One possible explanation is the high amount of sodium ions in MSG.In this study, we attempted to explain our results based on the hormesis phenomenon and the complex biochemical implications of GLA, also considering the advanced age of the rats.Hormesis is a dose–response relationship when a low-dose effect is opposite to the one observed at high doses. It can explain how cells respond to low-dose exposure to stressors . The adaTherefore, low-level ROS might activate different transcription factors sensitive to redox status changes, such as nuclear factor erythroid 2–related factor (Nrf2) . In respAlthough the inductor hormetic dose is difficult to establish and the hormetic mechanisms are probably more complex, with more responses activated upon oxidative stress, we attempted to bring this approach to our study. A decrease (even slightly) in the levels of some biochemical/metabolic parameters from the Control group to group 1, or even to groups 2 and 3, in some cases, may be due to the hormesis effect. This aspect can be observed in the case of AST, CHOL, TG, UR, DB and TB. In this case, low doses of MSG may have a protective effect in ageing rats. In the case of DB and TB, we may talk about an inverted U-shaped dose–response curve with the highest values in group 2. In the case of TG, we may consider a J-shaped dose–response curve, describing low-dose reduction and high-dose enhancement of adverse effects.Also, the biochemical implications of GLA may explain the defence mechanism triggered by sub-chronic MSG consumption. GLA is the primary nitrogen collector in the organism, transporting nitrogen from the tissues to the liver and kidneys for ureagenesis . IntestiThe key enzyme in CHOL synthesis is NADPH-dependent HMG-CoA reductase. NADPH is the coenzyme of glutathione reductase and aldose reductase, the key enzyme in glucose metabolism via the polyol pathway. Both of them are marker enzymes in oxidative stress . Increas2, generating reduced coenzymes (NADH and FADH2). The normal functioning of the Krebs cycle depends on the presence of both precursors, acetyl-CoA and oxaloacetate (OA), in equimolecular quantities. Insulin resistance in aged animals can alter Krebs’ cycle function, with an OA/acetyl-CoA ratio < 1, with serum hypertriglyceridemia as a consequence [TG are synthesised de novo in the liver, using intermediates of carbohydrate metabolism: acetyl-CoA as a precursor for fatty acid synthesis and dioxyacetone phosphate to obtain glycerol-3P (glycerol-3 phosphate). In the case of a calorie-balanced diet, acetyl-CoA will be oxidised in the Krebs cycle to COsequence . MSG admLogistical difficulties prevented us from conducting a parallel study on younger adult Wistar rats to compare MSG’s effect on different age groups. We could obtain valuable results through this approach, which would be a future research direction we propose. Also, a higher number of subjects in each group would have been indicated for better precision of the results.Also, due to logistical difficulties, it was not possible to examine the subjects who died before the end of the administration of the entire quantity of MSG. Therefore, some possible toxic effects of MSG that could have caused death were omitted.Extrapolating the results obtained on experimental animals to the human species is quite challenging. Achieving highly relevant data in this regard would require clinical trials.The self-administration method of MSG used in the study has advantages and disadvantages. Its limitations include the lower dosage accuracy than oral gavage or parenteral methods. Also, it relies on the natural circadian timing of alimentation and depends on individual preferences for flavours, palatability issues and changes in behaviour over time.Selecting the MSG doses administered within the groups to be relevant for the human species was difficult. The heterogeneity of doses administered in similar scientific studies contributed to this aspect.Although we tried to conduct the study in optimal conditions, we identified certain limiting aspects. However, some of these limitations can be overcome in the future, leading to valuable results. The limitations of this study are presented as follows:MSG is a controversial chemical substance, as both the advantages and disadvantages of its use are approached in the scientific literature. Despite the positive results of experimental studies regarding the toxicity of MSG at different levels, the regulatory authorities in food safety  do not question the safety of using MSG in food. Also, GLA metabolic pathways support its utility for the human body. The organism behaviour at ADI and NOAEL doses of MSG and how MSG toxicity is reflected in subjects potentially affected by advanced age was assessed using two-year-old Wistar rats.After evaluating the biochemical parameters, we can conclude that, even though, in most cases, there were no statistical differences in the levels of the parameters between the groups, there are some changes that could have biological importance. This aspect refers to ALT, ALP, DB, TB and UR, which are lower at high doses. Also, a decrease of AST, CHOL, TG, UR, DB and TB from the Control group to group 1, or even to groups 2 and 3, in some cases, could be observed. The hormesis effect, with low-level ROS protective effects and the biochemical implications of GLA, may represent the hypothesis of a potential defence mechanism triggered by MSG sub-chronic consumption in ageing rats.Among the experimental studies discussed in this article are those in which MSG toxicity is evaluated for a shorter administration period, included in the acute toxicity category. However, we could observe that even though smaller doses of the additive were administered for a shorter time than ours, MSG proved to produce pathological changes. This aspect is somewhat confusing because, according to our results, we cannot say that MSG was precisely harmful. On the contrary, we can affirm that, after the sub-chronic administration of MSG, the positive aspects of GLA are better reflected than the negative ones in ageing rats and could also be relevant for the elderly human population. This aspect is consistent with the fact that the regulatory authorities accept MSG in food safety, and it is widely used.Still, even considering all these aspects, it is not simple to formulate a conclusion regarding the acceptance limits of MSG among rats, even more so in the human species. A more profound approach to the subject is necessary to assess MSG sub-chronic consumption’s risk/benefit ratio.


Based on a per-lesion analysis, the detection rate of SPECT/CT was significantly higher than that of US (p = 0.01) and fhSEPCT/US (p = 0.003), and there was no significant difference in detection rate when comparing US to fhSPECT/US (p = 0.08). The main perceived limitations of fhSPECT/US in lesion detection were: (i) lesions localized at a depth ≥4.5 cm; (ii) imperfect image fusion due to tissue compression; (iii) limited spatial manipulation ability of the SPECT mobile camera handheld probe; and (iv) a wide spread of detected activity. In conclusion, clinical use of fhSPECT/US for localization of parathyroid adenomas is feasible, but shows lower sensitivity than conventional modalities and requires technical improvements.The aim of this prospective pilot study was to evaluate the feasibility of a new hybrid imaging modality, free-hand single-photon computed tomography/ultrasonography (fhSPECT/US), for preoperative localization of parathyroid adenomas and to compare its performance with conventional ultrasonography and SPECT/CT. Twelve patients diagnosed with primary hyperparathyroidism underwent sequentially US and parathyroid scintigraphy, including SPECT/CT, followed by fhSPECT/US, allowing for real-time fusion between US and freehand-generated gamma-camera images. The fhSPECT/US detection rates were correlated with histopathology, when available, or with the imaging modality showing the most lesions. Based on a per patient analysis, the detection rate was significantly different when comparing SPECT/CT to fhSPECT/US ( Primary hyperparathyroidism (pHPT) is a common endocrine disorder and the most frequent disorder of the parathyroid glands, affecting women above the age of 50 more often than men ,2. In apThe main treatment for pHPT is surgery, usually a minimally invasive parathyroidectomy in the case of solitary adenomas. Preoperative imaging is indicated to localize the pathological gland to be removed, as well as to identify patients with multiple hyperfunctioning glands who should undergo more extensive surgical exploration of the neck . SeveralScintigraphy is the most specific of the available imaging modalities 87%) [% [7]. SeCombining two imaging modalities increases diagnostic certainty in both simple cases  and more challenging cases . This enables the surgeon to plan the operation and make informed decisions regarding whether to perform minimally invasive parathyroid surgery or bilateral neck exploration. Hybrid imaging combining SPECT and CT during the same examination session has been shown to improve diagnostic performance such as sensitivity, specificity, and detection rate in pHPT ,9.®SPECT Imaging Probe . Feasibility studies have applied this new hybrid modality to thyroid imaging [A novel hybrid imaging modality was recently developed that allows for the fusion of SPECT and US: declipse imaging ,11,12, l imaging ,18,19,20 imaging . To our The purpose of the present study was to prospectively evaluate the feasibility of fhSPECT/US for the preoperative localization of parathyroid lesions in pHPT, and to compare its performance with the currently recommended combination of US and SPECT/CT.This was a single-arm prospective pilot study to collect quantitative and qualitative data regarding the feasibility and diagnostic performance of fhSPECT/US and compare it to recommended modalities for parathyroid imaging (US and SPECT/CT).®SPECT Imaging system  is provided with an infrared tracking system that allows for three-dimensional localisation of the gamma camera and the US probe (by tracking devices placed on the probes) with respect to a reference marker placed on or next to the patient.Patients referred for parathyroid scintigraphy from February 2019 to March 2020 were invited to participate. The inclusion criteria were as follows: age older than 18 years, biochemical diagnosis of pHPT , ability to lie on the examination table for an additional 30 min after the SPECT/CT , and providing written informed consent. Patients could be excluded from study for non-compliance or an inability to provide informed consent. Each enrolled patient sequentially underwent US, parathyroid scintigraphy including SPECT/CT, and fhSPECT/US, allowing for real-time image fusion . AlthougTo avoid inter-operator variability, the parathyroid US was always performed by the same expert endocrinologist (G.P.S.) using an Affinity 50 instrument  with two linear probes. One probe L18-5 had a better resolution, with a 3.5 cm width and a frequency ranging from 5 to 18 megahertz (MHz), and the other probe L12-5, had better penetration, with a 5 cm width and a frequency ranging from 5 to 12 MHz. In all cases, the US was performed before scintigraphy.™ instrument  with the following acquisition parameters: 60 30-s images and a 256 × 256 matrix for SPECT, and a dose modulation of 100 kv and slice thicknesses of 2 mm for CT, providing a useful field of view (FOV) of 500 mm.Next, parathyroid scintigraphy was performed after intravenous injection of 550 MBq of Technetium-99m methoxyisobutylisonitrile (Tc-99m-MIBI). This procedure included pinhole imaging approximately 45 min after injection (acquisition time: 10 min), followed by a SPECT/CT performed approximately 1.5 h post injection. The SPECT/CT was performed using a Symbia Intevo®SPECT Imaging Probe , with a SPECT duration of 1–5 min depending on tracer retention. Following fhSPECT imaging, an acquisition of US images was performed using a GE LOGIQ E9 ML6-15 linear probe  with a frequency ranging from 5 to 15 MHz and an acquisition depth fixed at 4.5 cm. These freehand images were captured each time by one of two experienced nuclear medicine physicians . The SPECT probe, Crystal Cam CXC-CT40A , was directed in vertical and horizontal planes around the patient’s neck to obtain multiple projections. The specifications of the cadmium zinc telluride (CZT) solid state camera were as follows: low-energy high-sensitivity collimator (LEHS), 9.4 mm spatial resolution. Reconstructions were performed in an iterative maximum likelihood expectation maximization (MLEM) fashion to generate 3D images using a sampling rate of 20 Hz and voxel sizes of 2 mm × 2 mm × 2 mm.Finally, fhSPECT/US imaging was performed using the declipseFollowing the fhSPECT/US acquisition, an additional pinhole image was obtained to analyze Tc-99m-MIBI washout (acquisition time: 10 min). Thereafter, injection of 200 MBq of Tc-99m pertechnetate was performed, and a pinhole image of the thyroid was obtained 10 min after the radiotracer injection (acquisition time: 10 min) . This seThe number and location of suspicious parathyroid lesions visualized on the first cervical US were indicated in the endocrinologist’s report, as is routine in clinical practice. The planar and SPECT/CT scintigraphic images, as well as the fhSPECT/US images, were viewed by two experienced nuclear physicians. The number and location of suspicious parathyroid lesions viewed on images were determined by consensus.Based on the results of the conventional imaging procedures (US and SPECT/CT), the patients were referred for surgical resection of their respective parathyroid lesions.The data collected for each patient included: age; sex; height; weight; Tc-99m-MIBI injected activity; images and results of US, SPECT/CT and fhSPECT/US, such as localization of parathyroid lesion , location of lesion(s) and lesion size; histopathology results; pre- and post-surgical laboratory variables such as PTH and calcium levels; and issues related to image acquisition.The study protocol was approved by the Vaud Cantonal Commission on Ethics in Human Research .p-value < 0.05 was considered significant.All statistical analyses were performed using Stata/IC software  version 15.0. Sensitivity, specificity, and accuracy were calculated and compared between the different modalities, using the results from histopathology as gold standard when available, or otherwise using the results of the conventional imaging modality (US or SPECT/CT) showing the highest number of lesions in the respective patient. Pairwise comparisons of the different modalities were carried out using the non-parametric McNemar test for dichotomous paired samples. For all statistical tests, a The characteristics of the cohort are summarized in Supplementary File S1.Across all imaging modalities, 16 lesions were detected in the 12 patients. US detected a total of 10 lesions in 10 patients, SPECT/CT detected 16 lesions in 12 patients, and fhSPECT/US detected 7 lesions in 7 patients . At the US detected 59% (10/17) of the lesions in 83% (10/12) of the patients. SPECT/CT detected 94% (16/17) of the lesions in all patients (100%). fhSPECT/US detected 41% (7/17) of the lesions in 58% (7/12) of the patients.p = 0.03), and not significantly different when comparing SPECT/CT to US (p = 0.16) and US to fhSPECT/US (p = 0.08). On a per-lesion analysis, the detection rate of SPECT/CT was significantly higher than that of US (p = 0.01) and fhSEPCT/US (p = 0.003), and no significant difference in detection rate was found when comparing US to fhSPECT/US (p = 0.08). The lesions detected were primarily in lower positions. Their locations were congruent between different imaging modalities.On a per patient analysis, the detection rate was significantly different when comparing SPECT/CT to fhSPECT/US . Technical issues were encountered when using this novel imaging modality in patients with successful and unsuccessful detection of parathyroid lesions. Indeed, failure of lesion detection by fhSPECT/US in five patients was related mainly to technical limitations. In two of these patients, the lesions were located too deep, which created problems for both US and fhSPECT/US. For example, in patient #1, the lesion, visualized on pinhole a and SPEIn one patient, the radiotracer uptake was visualized within the sternocleidomastoid muscle a and outIn the seven patients with detected lesions, some fusions also encountered technical issues; nevertheless, in these cases, detection was still possible despite suboptimal real-time fusion of US and fhSPECT images. One of the issues was the effect of excessively compressing the tissue for US imaging during the fhSPECT/US procedure, which was not the case for the fhSPECT part, as shown in The second issue observed in patients with detected lesions was the spread of activity detected by fhSPECT . The lesIn one patient, a lesion was not detected on the US, but it was detected using fhSPECT. The location was posterior to the trachea and thus not accessible to US imaging. Nevertheless, due to presence of radioactivity, visualization was possible with the fhSPECT acquisition but was not correlated to an anatomical structure on the fusion image c. The leBased on the fhSPECT/US real-time fusion image, the lesion measured 7 mm and was located at a depth of 3.2 cm. No US images were available due to a lack of exploration in this anatomical region.This pilot study evaluated the feasibility of fhSPECT/US in the preoperative localization of parathyroid adenomas in patients with pHPT, as well as its performance compared to stadard-of-care US and SPECT/CT.The problems observed with the use of this new imaging modality, fhSPECT/US, have also been reported in previous studies ,16,21,22The lack of detection could be related primarily to the limitation of the detection depth of the fhSPECT gamma camera due to the limited angle acquisition. This is currently set by device developers at 4.5 cm. This depth is acceptable for “normal” parathyroid gland locations, but it may not be sufficient for some ectopic locations. This was the case in our cohort for three lesions in retro-tracheal or para-esophageal region. This issue has already been noted by Bluemel et al. in sentinel node localization in obese patients, or when the depth exceeded 2 cm .One of the reasons for sub-optimal fusion mentioned in this work and in the literature is the habit of performing tissue compressions for US image acquisition. This compression causes tissue deformation and decreases the location depth of the investigated organ. Two studies proposed the use of pressure transducers to improve this problem and distribute compression evenly ,22. The Movements of the patient or of the locator that allows for infrared tracking may also explain suboptimal fusion . De BreeSpatial resolution is often described as insufficient in studies on sentinel node localization. Difficulties arise in the discrimination between the injection site and the node, or when several nodes are located close to each other ,15,22. FIn the literature, it is proposed to use a pinhole collimator to improve resolution . HoweverIt is important to note that for a correct fusion image, the pixel size of both imaging modalities must be identical. However, in this study, the US pixel size was not verified. This parameter can be very variable and depends on the examination depth and matrix size. It is usually within the millimeter range and therefore smaller than that of fhSPECT .We noted difficulties in the acquisition of the fhSPECT due to a limited number of angular projections as well as a restricted solid angle of the device. In several patients, the limited number of angular projections led to a spread of activity, and in others it led to an aberrant projection on the US image. Both parameters negatively influenced spatial resolution at greater depths, resulting in spreading of the signal and a less precise localization . An incrIn addition, manual scanning of the neck using the fhSPECT camera is performed randomly and is therefore very operator-dependent. It would be interesting to propose a robotic arm system holding the fhSPECT probe to establish a more systematic and efficient scan, allowing for a greater number of projections. Several authors have tested operator variability and proposed this possibility of a robotic arm to automate and standardize the procedure ,27,28. MAnother proposed improvement would be to substitute the current reconstruction algorithm, maximum likelihood expectation maximisation (MLEM), with an ordered subset expectation maximisation (OSEM) method. OSEM is an accelerated version of MLEM that classifies iterations into subsets to speed up reconstruction. For an MLEM reconstruction with 16 iterations, it is possible to perform an OSEM reconstruction with four iterations and four subsets (which will be four times faster), or with two iterations and eight subsets (which will be eight times faster) .In summary, optimization of fhSPECT for clinical use in parathyroid lesion localization would require several technical modifications of the probe and system design.p < 0.0001) on accuracy and differentiation of thyroid lesions from parathyroid lesions [SPECT/CT was the most successful imaging modality in this study, as it detected all the parathyroid lesions in all the patients. Interestingly, the performance of fhSPECT/US was inferior to that of US, even though both imaging modalities used US. This might be explained in part by a difference in experience of the US operators, given that the fhSPECT/US was performed after US and SPECT/CT  and the  lesions . AnotherThis pilot study has several limitations. The limited sample size and the small number of surgeries performed likely impacted our performance estimates. Moreover, only sensitivity could be calculated because it was not possible to calculate specificity in the absence of true negatives. Another limitation was that the fhSPECT/US images were not performed blindly, as physicians were aware of planar and SPECT/CT images, as is done in clinical routine. Thus, the operators were guided in their explorations.Notwithstanding these considerations, the feasibility of fhSPECT/US as a new imaging modality for the localization of parathyroid lesions was well assessed, and several relevant observations were made. While it is difficult to ensure that these observations were exhaustive, several of them were made repeatedly during the study and were also reported by others in the literature. Conversely, all the issues identified in the literature were also observed in the present study, considering the relative paucity of data with this technique, with a few published studies in general and only two case reports specific to parathyroid lesions ,21.The development and use of this new hybrid imaging modality are not intended to replace SPECT/CT. However, it could be proposed in special cases such as claustrophobic patients or patients refusing additional CT irradiation. If, after necessary improvements, fhSPECT/US could replace US in some cases, such as to detect whether there is associated thyroid pathology, it could reduce the number of appointments for the patient and potentially reduce healthcare costs. Finally, once technical issues have been resolved, fhSPECT/US could also provide added value in countries or areas that do not have access to SPECT/CT imaging.One main limitation of US, in general, is its operator-dependent nature ,8,31. SiPerformance of fhSPECT and US imaging requires the operator to be in a position close to the patient, which may raise concerns about radiation protection. A higher dose to the whole body and hands is inevitable. Nevertheless, in a study on hand dose during thyroid investigations with Tc-99m injected activities between 60 and 80 MBq, operators received an average dose of 9.25 µSv at the extremities per procedure during an acquisition of approximately 20 min . In paraTo our knowledge, this pilot study is the first to investigate fhSPECT/US in a prospective cohort of patients undergoing parathyroid investigations. The results indicate that its use for this purpose is feasible but requires technical improvements. The technical limitations identified in this preliminary analysis were primarily due to to detection challenges related to depth, excess tissue compression during US, and restrictions in the spatial manipulation of the US probe and SPECT camera. The sensitivity of fhSPECT/US was lower than that of US or SPECT/CT. Different plausible explanations can be proposed, such as detection challenges related to depth, operator-dependent handling of US and fhSPECT, and the presence of locators on the devices that limited the angles of detection. After technical improvements are made, further studies are warranted to clarify the potential role of this hybrid modality in clinical routine.