Background: Oxidative stress from exercise can contribute to damaging cells, increasing heat shock protein 70 (HSP70) and suppressing the immune system in the body. This research aimed to determine the antioxidant potential of red-fleshed pitaya extract on HSP70 and cortisol expression in rats which were subjected to strenuous exercise.Methods: The subjects of this research were 32 Sprague Dawley male rats, aged 3 months, with an average weight of 200 g. Red-fleshed pitaya extract was obtained from methanol extraction process; a maceration technique was performed and the extract was concentrated using an air-drying method. Rats were randomly divided into four groups. Group 1 were subjected to strenuous exercise and treated with distilled water only; while Groups 2, 3 and 4 were subjected to strenuous exercise and treated with 100 mg/kg body weight, 200 mg/kg body weight and 300 mg/kg body weight of red-fleshed pitaya extract, respectively. Strenuous exercises in rats was performed by intense swimming of 20 min/day, 3 days a week for 3 weeks. HSP70 expression and cortisol were measured with Enzyme-Linked Immune Sorbent Assay (ELISA) method.Results: There was a significant reduction of HSP70 (p=0.000) and cortisol expression (p=0.000) between the groups. Also, there was a significant difference in the average decreasing of HSP70 expression between group 4 and either groups 1 or 2 (p=0.000). However, a significant difference between groups 4 and 3 was not observed (p=0.813). Lastly, a significant difference was found in the average decrease of cortisol expression between groups 4 and 1 (p=0.000), 2 (p=0.000), and 3 (p=0.000) respectively.Conclusion: Red-fleshed pitaya is potential to be utilized as antioxidant to decrease the HSP70 and cortisol expression. Strenuous exercise tends to trigger free radical compound production. Moreover, this impairs the balance of free radicals and antioxidants as a result of oxidative stress. Research has discovered that oxidative stress from strenuous exercise reduces performance as it damages cells, causing pain and muscles fatigues, lowering antioxidant levels, increasing the expression of heat shock protein 70 (HSP70) and suppressing the immune system. Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle. Exercise can stimulate increased concentration of HSP70 in muscles and plasma.Physical activity is an activity which has various influences and significant effects on the body. The effect of regular physical activity is a positive influence on biological functions, and will improve health and the antioxidant defense system in order to protect body from the negative effects of oxidative damage. Previous research reported that workouts increase HSP70 expression. Strenuous exercise is a physical stressor in the body and as a result, adrenocorticotropic hormone(ACTH) is secreted by hypothalamus hypo-physis anterior and triggers the adrenal cortex to produce cortisol. The escalation of cortisol is influenced by the intensity and duration of training that leads to a suppression of the immune system, resulting in a decline of antibody. Cortisol can be a sign that the body encounters a decline in the immune system due to heavy training. Antioxidants can detoxify the lipid peroxide produced during exercise, which can eliminate radicals and reduce the inflammatory response to exercise. Therefore, it can prevent a muscle damage from exercise.During an intense workout, self-defense and self-adaptation depend on the body condition which can be observed from HSP70 protein expression. Increases of HSP70 in muscles indicates a response to protect muscles cells from oxidative stress. HSP70 expression is an adaptation mechanism and a sign of damaging cells caused by oxidative stress. Sources of exogenous antioxidants are Vitamin E, C and also beta-carotene. External antioxidants from food or supplements can help the body to fight an excess of free radicals. In a previous study, proanthocyanidin from grape seed was given to rats for 2 weeks. As a result, it lowered malondialdehyde level and increased the superoxide dismutase and glutathione peroxidase was activated significantly. Furthermore, it reduced fatigue after physical activitie.The body needs exogenous antioxidants to neutralize and prevent chain reactions from free radicals formed from heavy physical trainingsHylocereus polyrhizus) is a unique fruit with a lot of benefits. The fruit is recently popular among Indonesians and appears to be a natural antioxidant. Several in vitro studies have revealed that red-fleshed pitaya extract has the potential to be an antioxidant. This research aimed to investigate the antioxidant potential in red-fleshed pitaya extract on HSP70 and cortisol expression in rats that were subjected to strenuous exercise. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol. Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.Red-fleshed pitaya  in experimental animal cages of the Pharmacy laboratory, University of Sumatera Utara, Indonesia. The cage is made of plastic (30 x 20 x 10 cm) and covered with fine wire mesh. The base of the cage is covered with rice husk as thick as 0.5 - 1 cm and replaced every day during the research. The room light was controlled to be exactly at 12 hours light and 12 hours dark cycle, while the temperature 25–27°C and humidity of the room were adjusted to a normal range and fed with standard rat pellets 551, and drink (tap water) was givenThe research applied a laboratory experiment method with random group posttest-only design. The male rats were obtained from the Pharmacy Laboratory, University of North Sumatra. The experimental animals were simple random sampling divided into four groups: Group 1 was subjected to strenuous exercise and treated with distilled water only; Group 2 was subjected to strenuous exercise and treated with dosage 100 mg/kg body weight of red-fleshed pitaya extract; Group 3 was subjected to strenuous exercise and treated with dosage 200 mg/kg body weight of red-fleshed pitaya extract; Group 4 was subjected to strenuous exercise and treated with dosage 300 mg/kg body weight of red-fleshed pitaya extract.Giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.Red-fleshed pitaya fruit, obtained from farmers, in Indonesia, was peeled, washed, cut into small pieces and then dried in a drying cabinet. After that, the fruit was blended using a blender. The fruit extract was isolated through maceration method by using ethanol 96% which has been distilled as much as 10 times the weight of red-fleshed pitaya powder. Red-fleshed pitaya fruit powder in a container had 96% ethanol added to it , and then was soaked for 3 days then filtered and sealed. The macerates were collected in a container and then processed with rotary evaporator at a temperature of 45°C until the extract was thickened. After that, the same process of were repeated the remaining ethanol 96% for 3 days. The less thickened extract was then evaporated in a water bath until a thick extract was obtained.100 mg red-fleshed pitaya extract was weighed. Then, it was gently ground using a pestle and mortar. After that, carboxy methyl cellulose (CMC) Na 0.5% solution was slowly added and ground until a homogeneous phase was achieved. Finally, the suspension was added to a 10 mL measuring flask until it reached the mark line. The allocation of red-fleshed pitaya extract, dosage of 100 mg/kg body weight, for instance: weight of 200 g, volume taken: 2 ml extract suspension. Dosage of 200 mg/kg body weight, for instance: weight of 200 g, volume taken: 4 ml extract suspension. Dosage of 300 mg/kg body weight, for instance: weight of 200 g, volume taken: 6 ml extract suspension.Strenuous exercise given to all rats was a morning swim between 8–9 am for 20 minutes/day, 3 days a week over 21 days. The equipment used in this research was a 10-cm length and 25-cm diameter bath as a pool. Group 1, the rats received distilled water only; Group 2, the rats received 2 ml red-fleshed pitaya extract suspension; Group 3, the rats received 4 ml red-fleshed pitaya extract suspension; Group 4, the rats received 6 ml red-fleshed pitaya extract suspension. Administration of red-fleshed pitaya extract suspension and water was performed orally once daily for 21 days.Testing for HSP70 and cortisol was conducted two days after the rats had completed a strenuous exercise, 3 days a week over 21 days. During the test, the rats were given a maximum training session by swimming as hard as they could until the rats drowned or showed fatigue symptoms such as the entire body almost dipped into water and limb movements slowed down. After that the rats were sacrificed by placing them in a jar containing cotton which was moistened with 10 ml of chloroform. After that, 2–3 ml blood was taken from the heart. Blood samples were collected in micro tubes and centrifuged at 3000 rpm for 15 minutes. The serum was separated and stored at a temperature of 20°C until the analysis process would be carried out. Cortisol was measured with enzyme-linked immune sorbent assay (ELISA); Mouse Cortisol Elisa kit  and UV spectrophotometry at a wavelength of 450 nm. The HSP70 expression was recorded with ELISA; Mouse HSP70 Elisa Kit ; the absorbance was indicated at 405 nm.Data was analyzed using SPSS 22 for Windows and displayed in tables and diagrams. Normality test was conducted through Shapiro-Wilk test (P > 0.05) in order to determine the average of normal distribution of sample data which is presented as mean ± SD. The result of the normality test was used for next analysis; parametric analysis was used for normal distribution, otherwise non-parametric analysis was used. The ANOVA statistical analysis was performed to indicate the effects of treatments for each group. If the significant result is obtained, then the procedure is followed by Least Significance Difference or Bonferroni tests.The research was performed on the animal subjects were in according with the ethical standards by the Animal Research Ethics Committees/AREC, Faculty of Mathematics and Natural Sciences University of Sumatera Utara, Indonesia .All efforts were made to reduce any suffering of the rats was during the experiments by following careful procedures and also by anaesthetizing the animal prior to scarifice to prevent experiencing any pain.A normality test indicated that the data are normally distributed . HSP70 eCortisol expression was also decreased across all groups (119.02 vs 86.11 vs 62.94 vs 40.86 pg/mL). Group 4 had the lowest expression compared with the other groups. An ANOVA test revealed a significant decrease in cortisol expression (p=0.000) between the groups .Based on the results of this research, it is found that strenuous exercise combined with daily red-fleshed pitaya extract consumption contributes to a declining expression of HSP70 and cortisol. The dosage of 300 mg/kg body weight red-fleshed pitaya extract was found to be the optimum amount in decreasing cortisol compared to 100 and 200 mg/kg body weight dosage. However, for both 300 mg/kg body weight and 200 mg/kg body weight dosage of red-fleshed pitaya extract could not provide any difference to HSP70 expression. Therefore, the red-fleshed pitaya extract can be categorized as a potential exogenous antioxidant to eliminate free radicals formed during strenuous exercise.. During strenuous exercise, oxygen consumption rises by 20 times. The excess oxygen triggers the formation of free radicals with electrons released from the respiratory chain. Free radicals production from activity, especially superoxides, increases in the mitochondria. When an imbalance happens due to the excess of free radicals, oxidative stress occurs and damages the DNA. Moreover, proteins will lose their structure and function like enzymes and membrane receptor. Also, there will be damage in the lipid bilayer structure.Free radicals are an element that possesses one or more unpaired electrons in its outermost orbital. Consequently, it is very reactive to cells or cell components in its surroundings. Commonly, a reactive element finds its pair by attacking and binding with adjacent electrons. Then, if this element reacts with another radical element, a new radical element will be formed. This will consistently continue to occur leading to an unavoidable chain reaction. HSP70 is an important protein molecule for cell healing and preventing homeostasis and also increased expression as a cyto-protective effect. The HSP70 is induced strongly due to oxidative stress as cyto-protective to prevent the oxidative damages and heal the broken proteins. The increase of HSP70 expession is aimed to balance between ischemic condition, high temperature and the increased production of free radical. In this research, it is found that HSP70 expression tends to decrease in a group with strenuous exercise combined with red-fleshed pitaya extract.Strenuous exercise triggers the oxidative stress to occur, therefore, the HSP70 expression will elevate and resulting in a decrease of endogenous antioxidant activity. Strenuous exercise is associated with increased HSP70 expression due to oxidative stresset al., (2003) that antioxidant supplementation is proven to be effective to slow down the HSP70 synthesis caused by high intensity exercise. Other researches have also by Petizet al. (2017) which discovered that Vitamin A combined with high intensity acivities could prevent tissue damage and reduce endogenous antioxidant defense regulation in rats, which also suppressed the HSP70 expression.The results of this research is in accordance to a research by Kassaf. This is occured due to the potential of red-fleshed pitaya as an antioxidant that is able to balance the increasing amount of free radicals formed and impairs HSP70 synthesis induced by strenuous exercise. Therefore, the HSP70 expession is lower compared to the groups that are not given by red-fleshed pitaya extract.The red-fleshed pitaya extract combined with strenuous exercise is proven to be able to inhibit the increasing of HSP70 expression. Red-flehed pitaya (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants because that red dragon fruit contains the most polyphenols compared to other species.Physical activity appears to occur concomitantly with up-regulation of endogenous antioxidant systems and heat shock proteins (HSP) in skeletal muscle. While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by strenous exercise. Stress resulted from physical activity like oxidative stress is responded by hypothalamus to secrete corticotrophin realizing hormone (CRH) which then delivers a message to pituitary anterior. The pituitary produced adrenocorticotropic hormone (ACTH) which is useful to activate or affect adrenal cortex where cortisol hormone is secreted. Cortisol conttributes a massive influence to immune responses as a sign that the body is suffering from oxidative stress. In this research, cortisol hormone level tends to decreased in the group with strenuous exercise combined with red-fleshed pitaya extract.Physical training combined with low to medium dosage of red-fleshed pitaya extract were measured based on the ability and lead to immunomodulation effect that affect the body immune system and protect the body from cell damages, resulting in an effective condition to reduce the oxidative stressThis occurs since the red-fleshed pitaya extract is an effective antioxidant to reduce the risk of oxidative stress and is able to decrease the secretion of cortisol by reducing ACTH secretion in the hypothalamus and CRH in the pituitary gland. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase. Provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise programet al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that Hylocereus Polyhizus can reduce cholesterol levels in rats.Red-fleshed pitaya is the cactus fruit of the genus Hylocereus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by WidyaningsihBased on this research, it can be concluded that red-fleshed pitaya extract has the potential to be antioxidant with its anthocyanin content, and is able to eliminate oxidative stress due to strenuous exercise. It can be observed by the decreased pattern of HSP70 and cortisol expression in the strenuous exercise combined with red-fleshed pitaya extract group. Furthermore, we find out the optimum result was shown in potential of red-flehed pitaya as an antioxidant and the dosage of effective dose at 300 mg/kg body weight of red-fleshed pitaya extract. can reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise. given dose at 300 mg/kg body weight of red-fleshed pitaya extract was indicated to be more effective for reducing HSP70 expression.Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats,https://doi.org/10.17605/OSF.IO/MGX4KOpen Science Framework: The effect of red-fleshed pitaya (Creative Commons Zero “No rights reserved” data waiver (CC0 1.0 Public domain dedication).Data are available under the terms of the I have read the details of the author's revision. I decide that I agree with all revisions made by the author. I think this article deserves to be indexed.Is the work clearly and accurately presented and does it cite the current literature?YesIf applicable, is the statistical analysis and its interpretation appropriate?YesAre all the source data underlying the results available to ensure full reproducibility?YesIs the study design appropriate and is the work technically sound?YesAre the conclusions drawn adequately supported by the results?YesAre sufficient details of methods and analysis provided to allow replication by others?YesReviewer Expertise:Medical Physiology: exercise physiology; endocrine and metabolic physiologyI confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. It is an interesting manuscript. However, there are several grammatical issues and some typos that you should check very carefully.My main concern about your manuscript is that you have not mentioned any strengths or limitations in your study.The small number of rats per group is indeed a limitation and should be mentioned and taken into consideration before making conclusions.Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise-induced rats.This is a prospective study on the effect of red-fleshed pitaya .Note: There are some grammatical errors, you should use the proof-read service.Is the work clearly and accurately presented and does it cite the current literature?YesIf applicable, is the statistical analysis and its interpretation appropriate?YesAre all the source data underlying the results available to ensure full reproducibility?YesIs the study design appropriate and is the work technically sound?YesAre the conclusions drawn adequately supported by the results?YesAre sufficient details of methods and analysis provided to allow replication by others?YesReviewer Expertise:Medical Physiology: exercise physiology; endocrine and metabolic physiologyI confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Introduction:1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C . The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content  around 26,457 ppm. Dragon fruit contains flavonoids . Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids . Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms . The results of previous studies ripe dragon fruit contains many organic acids , protein , minerals such as potassium, magnesium, calcium and iron and vitamin C . Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle . Exercise can stimulate an increased concentration of HSP70 in muscles and plasma. Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body . Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion .Methods:1.  Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose. Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.       2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine . From the results of previous studies, ripe dragon fruit contains many organic acids , protein , minerals such as potassium, magnesium, calcium and iron and vitamin C .circadian.3. Explain the time of blood-sampling because cortisol production is influenced byCortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.Discussion:1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress .Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma .Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle . While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise .Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels .Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program . Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase .The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels. Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol . Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise.  So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.


If a pediatric recipient has a live donor (LD) kidney option available, should they opt for this transplant first or opt for a deceased donor (DD) transplant first and save the LD option for later if required?In this decision analytical model, opting for an LD transplant first most often provides more remaining life-years. However, opting for a DD transplant first and saving an LD for retransplant after the DD transplant fails may result in a similar number of remaining life-years for recipients aged 10 to 14 years while the LD remains available.With the contemporary trend of proportionately fewer LD kidney transplants for pediatric recipients, programs should promote LD kidney transplant as the first option for pediatric recipients. This decision analytical model assesses conditions that favor a deceased donor transplant followed by a live donor transplant sequence or vice versa in pediatric patients with kidney failure. In the US, live donor (LD) kidney transplant rates have decreased in pediatric recipients. Pediatric patients with kidney failure will likely need more than 1 kidney transplant during their lifetime, but the optimal sequence of transplant  is not known.To determine whether pediatric recipients should first receive a DD allograft followed by an LD allograft (DD-LD sequence) or an LD allograft followed by a DD allograft (LD-DD sequence).This decision analytical model examined US pediatric patients with kidney failure included in the US Renal Data System 2019 Report who were waiting for a kidney transplant, received a transplant, or experienced graft failure.Kidney transplant sequences of LD-DD vs DD-LD.Difference in projected life-years between the 2 sequence options.Among patients included in the analysis, the LD-DD sequence provided more net life-years in those 5 years of age  and 20 years of age  compared with the DD-LD sequence. The net outcomes in patients 10 years of age  and 15 years of age  were not significantly different. However, for those aged 10 years, an LD-DD sequence was favored if eligibility for a second transplant was low  or if the LD was no longer available . For those aged 15 years, the LD-DD sequence was favored if the eligibility for a second transplant was low  or if the LD was no longer available . Access to multiple DD transplants did not compensate for missing the LD opportunity.These findings suggest that the decreased use of LD kidney transplants in pediatric recipients during the past 2 decades should be scrutinized. Given the uncertainty of future recipient eligibility for retransplant and future availability of an LD transplant, the LD-DD sequence is likely the better option. This strategy of an LD transplant first would not only benefit pediatric recipients but allow DD kidneys to be used by others who do not have an LD option. Live donor transplant has decreased by 27% in recipients aged 18 to 34 years but increased by 21% in recipients older than 50 years.2 The reasons underlying this change are unclear.During the past 2 decades, live donor (LD) kidney transplant rates in the US have decreased, but of greater concern, the decrease has been uneven.2 Furthermore, some DD kidneys may be of higher quality than LD kidneys,3 and the ready availability of high-quality kidneys may be influencing the decision to opt for a DD kidney now to save an LD transplant for later.4 This strategy may have some benefit, given the longer waiting-list time and potential for lower-quality kidneys for those with a failed LD transplant who are wait-listed again in adulthood. In contrast, the potential LD allograft may no longer be available , leading to a lost opportunity for transplant.There are potential explanations for this decrease in pediatric LD transplants. Deceased donor kidney allocation algorithms heavily prioritize pediatric transplant. At present, pediatric DD transplant rates are 40 per 100 patient wait-years compared with 15 per 100 patient waiting list–years in adults. Pediatric recipients also receive high-quality kidneys (75% receive a kidney with a kidney donor profile index of <20 and 95% with a kidney donor profile index of <35).It is not clear whether the sequence of DD followed by LD (DD-LD) transplant is better than the sequence of LD followed by DD (LD-DD) transplant for long-term patient survival. However, both a lower availability of LD kidneys and deferred LD transplant rates may have considerable negative consequences for outcomes of pediatric patients with kidney disease. Therefore, the purpose of this medical decision analysis was to explore the conditions that would favor one sequence over the other.CHEERS) Checklist.5Research ethics approval and informed consent were waived by the Nova Scotia Health Authority Research Ethics Board for use of retrospective publicly available data. Reporting followed the Consolidated Health Economic Evaluation Reporting Standards , patients received an LD transplant without waiting. If this failed, they had the possibility of returning to the waiting list and obtaining a DD transplant A. In opt6 Annual rates of graft loss were calculated from 5-year probabilities of graft failure for LD and DD kidney transplants  after a failed first transplant were 20% for an LD and 15% for a DD transplant.11 At baseline, we assumed 10% of LD kidneys would not be available in the DD-LD sequence. We assumed the third transplant would not be preemptive. A detailed list of assumptions is outlined in eTable 4 in the The model assumed a high probability (100%) of candidacy  until 30 years of age. Thereafter, the probability of candidacy fell to 80% by 50 years of age, to 30% by 60 years of age, to 5% by 70 years of age, and to 0 (no option for a transplant) by 80 years of age (eTable 3 in the 6), and (6) having rates of LD graft loss 50% lower than the corresponding rates of DD graft loss for those aged 10 to 24 years  different probabilities regarding the availability of the LD transplant (DD-LD sequence), (2) different rates of DD transplant, (3) different probabilities of being a candidate for a second transplant, (4) different probabilities of receiving the second transplant preemptively, (5) lowering waiting-list mortality for patients aged 3 to 9 years . The cycle length was yearly. Uncertainty in the net difference between options was examined by Monte Carlo microsimulation  to calculate 95% CIs.6 who were waiting for a kidney transplant, received a transplant, or experienced graft failure. Data were analyzed from November 6, 2020, to June 1, 2021. The study population included US pediatric patients with kidney failure in the US Renal Data System 2019 ReportAs shown in Additional sensitivity analyses are shown in eTable 6 in the Differences in the overall numbers of DD kidneys projected to be transplanted between the 2 sequences was also estimated. From 3 to 25 years of age, 0.45 to 0.55 more DD kidneys were used per recipient in the DD-LD group, assuming that an LD kidney was always available . If the Under most reasonable circumstances, the LD-first option maximizes recipient life-years. Nonetheless, using the LD-second option appears to be justified in recipients aged 10 to 14 years if an LD is always available and a transplant can always be performed preemptively or if recipients reside in a region with very low rates of adult transplant. Most importantly, this study found that a pediatric cohort with access to multiple DD kidneys would not, on average, outperform a cohort that also has access to LD kidneys.This study also demonstrates the importance of the very high pediatric DD transplant rate. If pediatric rates of DD transplant were the same as in adults, then the benefit of a DD-LD sequence would always be inferior to the LD-DD scenario. Prioritization of DD kidney transplant for pediatric recipients has greatly improved patient survival but may have inadvertently reduced LD rates and remaining life-years.13 The benefit of an LD-first sequence was negated if the mortality rates in the cohort of patients aged 3 to 9 years were reduced. The reasons for this finding are not clear, but this younger cohort may be more vulnerable to the rigors of dialysis; regardless, this finding requires further study. If this younger cohort is truly more vulnerable to dialysis, then even greater access to LD transplant through enhanced family support or even higher priority for DDs is needed. Some parents with very young children might have fewer supports to participate as LDs while being the primary caregiver for their child. The DD waiting list may be the only option. It may be that the overall trend for lower LD rates is a consequence of stricter eligibility criteria for LDs, particularly because donation is associated with an increased risk of kidney failure.14 Because parents may be having children at a later age, they may have more comorbidities that preclude donation. However, the registry data show that parent-to-child donation has fallen 46%, from 1823 transplants in 2001 through 2005 to 987 in 2015 through 2019, whereas parent-to–adult offspring donation has fallen only 30%, from 2377 to 1656 transplants.1This analysis also demonstrates the importance of waiting-list mortality. The benefit of a DD-first sequence is almost entirely realized by patients aged 10 to 14 years, because this is the group with the lowest waiting-list mortality. In contrast, the analysis shows that because of the relatively high waiting-list mortality of patients younger than 10 years, they are better served with an LD-first sequence. It is interesting to note that mortality rates for the general population and individuals with a functioning transplant tend to be lower from 5 to 9 years of age compared with individuals aged 10 to 13 years.16 In general, rates of graft failure are higher for DD compared with LD transplants for all patient ages; however, the rates are disproportionate at different ages.6 The rates of graft loss seem relatively high in LD compared with DD transplants during adolescence. High rates of graft loss could be associated with greater nonadherence to medication, poor transition from pediatric to adult care, physiologic stresses associated with development during adolescence, or recurrent disease.18 Smaller differences could be from the better-quality DD organs relative to LD kidneys in this age group, but that would not be consistent with the higher rates of graft loss and the disproportional differences seen in the younger pediatric cohorts. Interestingly, higher rates of graft loss during these years are not observed with liver transplants.17 Livers may tolerate lapses in immunosuppression due to nonadherence or may be better able to respond to the growing metabolic demands of adolescence than kidneys. Nonetheless, deferring the LD transplant to a time when outcomes are better is conceptually similar to deferring spending to a time of better purchasing power. Overall, the effect was smaller than we might have expected and benefits patients aged 3 to 13 years more than patients older than 14 years.We examined the high rate of graft failure during adolescence to determine whether there were any associations between adolescence and the different sequences.19 However, information on the probability of a patient being medically eligible for retransplant is not well studied.22 Any reduction in later candidacy will affect the DD-LD sequence more than the LD-DD sequence.One of the more important unknowns is whether a pediatric patient will be eligible for a second transplant years later. The trend has been to refer, wait-list, and provide transplants to older recipients.11 Studies also show greater sensitization and lower rates of transplant in patients who undergo transplant with a DD kidney first compared with an LD kidney first, which further supports an LD-first sequence.11 Delays may be unavoidable . For recipients who have developed HLA antibodies to their LD transplant, entering a paired exchange registry or desensitization are options. However, desensitization may be associated with inferior outcomes.23 On the other hand, an LD who was not available at the time of incident kidney failure may become available when the patient is older . Having an LD allograft first also opens the possibility of an LD-LD sequence, which would provide even better outcomes  at a rate that is not very different from those less sensitized.2 We did not explore HLA mismatch effects. For example, recipients of HLA identical kidneys will likely have better survival and less subsequent sensitization if the graft fails regardless of when used.There are limitations to our study. We assumed for the base case that 10% of the time an LD would not be available for the second transplant. Because the actual percentage is unknown and not easily predicted, we examined the entire range of possibilities. We assumed an LD would always be available sooner compared with a DD from the waiting list. This may not be true if the LD workup is delayed or prolonged. We used aggregate data by age groups ; therefore, whether age 8 or 9 or 10 years is a better threshold for a change in option superiority is not certain. We also did not examine the effect of individual donor and recipient characteristics on outcomes.Understanding the relative benefits of one kidney transplant sequence compared with another is a complex combination of time-varying mortality for the different health states, rates of graft failure that differ by organ source, kidney transplant rates, candidacy for a second or third transplant, and probability that an LD available now will be suitable years later. Opting for an LD kidney first provides more net life-years under most scenarios; opting for a DD kidney first and delaying the LD to be a backup in a pediatric recipient is preferred only under a few narrow conditions. The novel aspect of this decision analytical model is that it allowed us to identify, isolate, and quantify the variables associated with this choice. Regardless, the reduction in LDs in this population during the last 20 years has and will have a significant negative effect on patient outcomes. Preemptive LD transplant should be vigorously pursued for all age groups.


To evaluate the efficacy of a barrier shield in reducing droplet transmission and its effect on image quality and radiation dose in an interventional suite.A human cough droplet visualisation model in a supine position was developed to assess efficacy of barrier shield in reducing environmental contamination. Its effect on image quality (resolution and contrast) was evaluated via image quality test phantom. Changes in the radiation dose to patient post-shield utilisation was measured.Use of the shield prevented escape of visible fluorescent cough droplets from the containment area. No subjective change in line-pair resolution was observed. No significant difference in contrast-to-noise ratio was measured. Radiation dosage to patient was increased; this is predominantly attributed to the increased air gap and not the physical properties of the shield.Use of the barrier shield provided an effective added layer of personal protection in the interventional radiology theatre for aerosol generating procedures.This is the first time a human supine cough droplet visualisation has been developed. While multiple types of barrier shields have been described, this is the first systematic practical evaluation of a barrier shield designed for use in the interventional radiology theatre. A barrier shield which we have named Safety in Interventional Radiology (SIR) Aerosol Generating Procedure (AGP) Shield was developed rapidly together with the UK Manufacturing Technology Centre engineers, working in collaboration with Rolls-Royce2 to reduce the risk of regional droplet spread from aerosol generating procedures.With the outlook of the COVID-19 pandemic stretching into the foreseeable future and multiple waves with new variants of concern occurring around the world, hospitals need to adapt to the “new normal”.3 It is a polygonal box with partially overlapping silicone flaps access on two sides of the box to facilitate access and dexterity for procedures with a silicone curtain on the patient side .We undertook this study to evaluate the effectiveness of the Shield in reducing droplet transmission, its effect on image quality, and radiation dose to the patient.Edible fluorescent fluid was derived by dissolving vitamin B complex  in quinine-based soda . Marking sheets were laid out in a 10 × 10m square and taped to the ground. Healthy volunteers gargled and ingested 20 ml of fluid, and coughed three times with their head centred within the square in a closed room. Droplets were allowed to settle for 30 min prior to evaluation. Three researchers assessed the splatter pattern and droplet range under ultraviolet-A light. Droplets were only included if there was consensus among all assessors.® Sporicidal Wipes  and 70% isopropyl alcohol wipes. To simulate repeated clinical use, each section was wiped once, left to dry and repeated 200 times. All sections were cleaned using a microfiber cloth before and after wiping prior to evaluation.A polycarbonate test plate  was separated into sections and subjected to repeated cleaning using surface disinfecting products: Ammonia-based Mikrozid Sensitive wipes , Virusolve+A light transmission test was carried out using a calibrated light detector . Each section of each test plate was inserted between a light box and the detector, and corresponding light intensity measurements were recorded. This process was performed 10 times to obtain ten sets of reference and intensity readings, before and after 200 cycles of cleaning.Slabs of 25 × 25 mm polymethyl methacrylate (PMMA) to a total thickness of 128 mm were placed on the couch of a Siemens Artis Zee Biplane system to simulate an adult patient. An image quality test phantom consisting of spatial resolution line-pairs ranging from 0.50 to 6.00 line-pairs per mm and 24 contrast dots was placed atop the PMMA slabs.The limiting spatial resolution was evaluated subjectively with 12 readers evaluating 10 blinded images of the phantom taken in five different settings with and without the Shield with the X-ray tube and the image intensifier in the same position. Images were exported and attached onto a PowerPoint slide show to standardise viewing and restrict image manipulation.U test was carried out to investigate the impact of the SIR shield on image contrast.Image contrast was evaluated by calculating the contrast-to-noise (CNR) ratio using the ImageJ software . The Mann–Whitney A calibrated solid-state dosemeter  was placed under the PMMA slabs, positioned at the edge of the field-of-view, and oriented perpendicular to the anode-cathode axis of the tube. Three positioning protocols were defined: native, elevated without Shield, and elevated with Shield. Native positioning simulated a routine exam by setting the table height to 98 cm and the detector height to 124 cm. Elevated positionings simulated use of the Shield with table and detector heights of 82 cm and 143 cm without and with the Shield in place.In single plane AP mode, five exposures were made based on machine default medium-sized patient settings to simulate clinical use: (A) 60 s fluoroscopy, (B) 20 s Digital Subtraction Angiography (DSA) on two frames per second (FPS), (C) 20 s DSA on 3 FPS, (D) 20 s DSA on 6 FPS and (E) single shot acquisition.a,i (Incident Air Kerma) readings from the dosemeter, and all Ka,r  and PKA (Kerma–Area Product) measurements from the Artis system were recorded.All KFour male volunteers (aged 35–41) took part in the cough visualisation experiment. There was good visualisation of the fluorescent droplets with three-person consensus on the localised and measurable droplets . MajoritWith the introduction of the AGP barrier shield, no fluorescent droplets were visualised on the marking sheets outside the containment area of the Shield.U test was carried out at the 5% level of significance. No significant difference was found between the light transmissions, both before and after using the disinfection agents  was demonstrated with and without use of the Shield.Contrast dots 1–6 show negative contrast attenuation and were therefore not clinically relevant to our analysis. The CNR of the remaining 18 dots were plotted with the x-axis showing increasing contrast for the five exposure protocols both with and without the Shield . Each coa,r and PKA.The collected dosimetry, and dosemeter recorded kV and exposure time, are shown below in A comparison of native and elevated position with shield demonstrated that the use of the Shield was associated with an increase in dose of 4.00, 3.98, 4.83, and 1.93 times for DSA 2FPS, DSA 3FPS, DSA 6FPS, and single shot acquisition respectively.Comparing elevated positions with and without the shield demonstrates the effect of the AGP shield to the increase in dose of 1.26, 1.10, 1.13, and 1.30 times for DSA 2FPS, DSA 3FPS, DSA 6FPS, and single shot acquisition respectively.The SIR AGP Shield has been evaluated by the UK Medicine and Healthcare products Regulatory Authority (MHRA) and the British Standards Institution (BSI), and is suitable for use as an adjunct to currently available personal protective equipment.4 Use of the Shield together with the hospital wall vacuum would provide a minimum equivalent rate of air exchange rate of a new negative pressure room to reduce chance of contamination to frontline workers.Existing Centers for Disease Control and Prevention (CDC) air exchange guidelines for negative pressure environment is 12 ACH for new rooms.5 demonstrated their potential utility in reducing large droplet spread.6 Our human fluorescent droplet visualisation model allows for direct visual confirmation that the large droplets can be retained within the confines of the box reducing risk to operators on splash exposure of infectious droplets. While there have been many studies on cough and sneezing simulation for droplet spread especially in the context of COVID-19,7–9 as far as we are aware, this is the first time that droplet spread from coughing has been assessed from supine position. This is more physiologically representative of the working conditions of the interventional radiology theatre, where the greatest risk is likely to be from the patient coughing directly beside the operator during aerosol generating procedures. For smaller non-visible micro-aerosols generated during coughing, a flow dynamics study10 utilising the same barrier shield has estimated greater than 99% reduction of airborne particulates in the 1–500 µm range.Early models of barrier shieldsAfter 200 cycles of cleaning utilising commonly available hospital disinfectants, the material used for the shield did not demonstrate any significant drop in optical clarity. The maintenance of the optical clarity is important for visualisation of the airway structures during procedures.Among the 60 paired subjective examinations of line-pair resolution, only one paired exam on acquisition was noted to have a one-step decrease in line-pair suggesting that the addition of the Shield is unlikely to have a significant impact on day-to-day fine resolution requirements. 10 out of 12 reviewers were also unable to discern any difference in spatial or contrast resolution with and without the use of the Shield. The minor differences observed by the two outlying observers may be of doubtful significance in routine use. There was no statistical evidence to show that overall CNR decreases with the use of the Shield.11 to reduce radiation dose and increase ACH rates when access to airway is no longer required. For procedures involving the lower thorax, abdomen or lower limbs, the use of the barrier shield should not result in any clinical change of the positioning of the image intensifier and therefore should not result in any change in radiation dose.The Shield itself does minimally contribute to the increase in radiation dose; however, the predominant cause of dose increase arises from the increased air gap between object and detector distance rather than the addition of the Shield. An option to reduce radiation dosage to patients would be to utilise the Shield for the initial intervention and subsequently switching to a smaller barrier shield like SIR HELMET12 By incorporating the use of a negative pressure barrier shield into routine practice on high-risk patients would provide an additional layer of protection to frontline healthcare workers against airborne/aerosolised pathogens and reduce environmental contamination. This would enable healthcare workers to perform their duties with greater peace of mind and reduced cognitive-load stress.Previous studies have documented extensive air, surface environmental and personal protective equipment contamination by symptomatic COVID-19 patients.


Firearms are common in the households of persons with Alzheimer disease and related dementias (ADRD). Safety in Dementia (SiD) is a free web-based decision aid that was developed to support ADRD caregivers in addressing firearm access.We aimed to evaluate the feasibility and acceptability of SiD among a web-based sample of ADRD caregivers.SiD was tested in 2 phases by using participants who were recruited from a web-based convenience sample . In phase 1, caregivers were randomized to view either the intervention (SiD) or the control , and the blinding of participants to the study arms was conducted. In phase 2, caregivers of individuals with ADRD and firearm access were recruited; all of these participants viewed the firearm section of SiD. In both phases, participants viewed SiD independently for as long as they wanted. Measures for evaluating decision-making and SiD acceptability were used, and these were assessed via a self-administered web-based questionnaire.Participants were recruited for phases 1 (n=203) and 2 (n=54). Although it was feasible to collect the study outcome data in a web-based format, in phase 1, there were no significant differences between SiD and the control in terms of decision-making and self-efficacy. The majority  of phase 1 participants spent between 5 and 10 minutes reviewing the resources. In phase 2, 61% (33/54) of participants spent 5 to 10 minutes viewing the firearm section, and 31% (17/54) spent 10 to 20 minutes viewing this section. Usability and acceptability were high across the phases.SiD represents a new resource for promoting safety among people with dementia, and high acceptability was achieved in a pilot trial. In this sample, SiD performed similarly to Alzheimer’s Association materials in supporting decision-making and self-efficacy. Most firearm deaths among older adults are the result of suicide, but memory and behavior changes resulting from Alzheimer disease and related dementias (ADRD) have raised safety concerns among care partners and others. Dementia safety guidelines ,2 recommWe previously created the web-based Safety in Dementia (SiD) decision aid ,7 to supHerein, we describe a pilot study for assessing the feasibility and acceptability of SiD among a web-based sample of caregivers. We sought to examine the feasibility of collecting outcome data and the acceptability of the tool in preparation for a future full-scale randomized trial. Although SiD situates firearm access within the context of other safety considerations  , we focuWe evaluated SiD in a 2-phase study by using samples from the Amazon Mechanical Turk (MTurk) platform . MTurk iIn phase 1, participants were randomized (1:1) to view either the intervention (SiD) or control . ParticAfter exceeding the target recruitment size for the pilot randomized trial (phase 1), we adjusted the eligibility criteria to specify that the person with ADRD must have access to at least 1 firearm (phase 2). This change was made to allow for the collection of additional focused feedback on the firearm section, and all caregiver participants in phase 2 were directed to view the firearm section of the SiD website. The SiD website content was frozen during this study, and no changes were made until after this study was completed. This study was approved by the Colorado Multiple Institutional Review Board, which waived the need for written informed consent.Web-based, self-administered questionnaires in Qualtrics  were used to assess the characteristics of participants and the people with dementia for whom they provided care.We assessed the feasibility of collecting data on key efficacy outcome measures from the Ottawa Decision Support Framework , which aTo analyze tool acceptability, we used the Ottawa Acceptability Scale  to assest tests for continuous variables and Fisher exact tests for categorical variables due to the small sample sizes in some groups. All phase 1 comparisons were conducted based on the intention-to-treat assignment to each study arm.Quantitative survey data were analyzed by using descriptive statistics. Continuous variables were summarized with means and SDs (or with medians and quartiles when a group had a sample size of <10). Categorical variables were summarized with frequencies and percentages. Differences in measures between the control and SiD arms in phase 1 and between the phase 1 and phase 2 cohorts were tested with 2-sample two-tailed Between March and August 2020, 257 MTurk individuals participated in this study; we excluded 6 individuals who did not complete the questionnaires. In phase 1, caregivers were randomized to view either the SiD (n=98) or the control (n=105); there were no significant differences in the characteristics of participants or people with dementia . The medIn phase 2, 54 participants were enrolled. Compared to those in phase 1, phase 2 participants were more likely to be male, people of color, and Hispanic and care for individuals with less severe dementia . In phasOverall, in phase 1, participants’ reported preparedness for decision-making and decision self-efficacy were both high, with no significant differences between the SiD and control groups . The medUsability and acceptability were high across groups, including both the SiD and control groups. The majority  of participants spent between 5 and 10 minutes reviewing the resources. Among those in phase 2, 61% (33/54) spent 5 to 10 minutes viewing the firearm section, and 31% (17/54) spent 10 to 20 minutes viewing the firearm section. A participant wrote:I think that the firearm material was very informative and thorough. It gave good examples of real-life situations and how to handle decisions base[d] upon many different perspectives (ex who owns gun) within the household. I felt like it was a very good resource to be able to rely on.With regard to the firearm section, 51% (36/71) of those who viewed it reported that it had the right amount of information, 83% (59/71) reported that most or all things were clear, 73% (52/71) reported that it was somewhat or very helpful, and 82% (58/71) reported that they would probably or definitely recommend it to others facing similar decisions or questions.SiD represents the first publicly available decision aid that addresses firearm access among people with dementia . This trThe Veterans Health Administration has created guidance memoranda for clinicians on when and how to counsel veterans with dementia (and their caregivers) about safe firearm practices . Some ADQuantitative and qualitative feedback resulted in the refinement of SiD. To make resources more accessible, we added a downloadable summary in each section. We revised the language to normalize the idea that solutions can take time and effort to enact. Further improvements to website navigation and flow  were made via consultations with a web developer.The limitations of this pilot study include the fact that participants were predominantly non-Hispanic, White individuals. Existing data indicate that firearm ownership and suicide are more common among White individuals than among other racial and ethnic groups , but morOur pilot trial results suggest that SiD represents a practical, interactive tool that is usable and acceptable among ADRD caregivers. SiD seeks to frame critical decision points and present information in clear and digestible segments to make decisions more manageable and, consequently, more likely to be enacted . Additio