Local Reactions Research Articles

Increased cortical density in popliteal lymphadenopathy as a promising radiological sign to help differentiate adverse local tissue reaction from infections in complications following a knee arthroplasty—three case reports

Increased cortical density in popliteal lymphadenopathy as a promising radiological sign to help differentiate adverse local tissue reaction from infections in complications following a knee arthroplasty—three case reports

Safety and efficacy of placental mesenchymal stromal cells-derived extracellular vesicles in knee osteoarthritis: a randomized, triple-blind, placebo-controlled clinical trial

BackgroundKnee osteoarthritis causes pain and disability in many people worldwide, for which no definitive treatment has yet been proposed. In this study, we investigated the safety and efficacy of placental mesenchymal stromal cells-derived extracellular vesicles in patients with knee osteoarthritis.MethodsThis triple-blind, randomized clinical trial included patients suffering from bilateral knee osteoarthritis with grade 2 or 3. The knees of each patient were randomized to intervention and control. For the intervention knee, 5 cc of placental mesenchymal stromal cells-derived extracellular vesicles were injected, and for the control knee, 5 cc of normal saline was injected. The patients’ symptoms were evaluated before the intervention and 2 and 6 months after the intervention using VAS, WOMAC questionnaire, and Lequesne index. MRI was performed before the intervention and 6 months after the intervention to evaluate retropatellar and tibiofemoral cartilage volume, medial and lateral meniscal disintegrity, ACL injury, and effusion-synovitis.Results62 knees (31 patients) were enrolled in this study. There were 31 knees as intervention and 31 knees as control. Finally, the data of 58 knees (29 patients) were analyzed, including 28 women and 1 man. The mean age of the patients was 55.38 ± 6.07 years. No statistically significant difference was detected between the two groups in clinical outcomes (including VAS, WOMAC, and Lequesne scores) before treatment and 2 and 6 months after treatment. Also, no statistically significant difference was detected between the two groups in MRI findings before treatment and 6 months after treatment. No systemic complications or severe local reactions occurred in the patients.ConclusionA single intra-articular injection of placental mesenchymal stromal cells-derived extracellular vesicles (5 cc, 7 × 109 particles/cc) is safe, but does not improve clinical symptoms or MRI findings in knee osteoarthritis beyond placebo. The protocol of this study was approved on 11 May 2022 with registration number IRCT20210423051054N1.

Comparing the Ground Reaction Forces, Toe Clearances, and Stride Lengths of Young and Older Adults Using a Novel Shoe Sensor System

In this study, we developed a lightweight shoe sensor system equipped with four high-capacity, compact triaxial force sensors and an inertial measurement unit. Remarkably, this system enabled measurements of localized three-directional ground reaction forces (GRFs) at each sensor position (heel, first and fifth metatarsal heads, and toe) and estimations of stride length and toe clearance during walking. Compared to conventional optical motion analysis systems, the developed sensor system provided relatively accurate results for stride length and minimum toe clearance. To test the performance of the system, 15 older and 8 young adults were instructed to walk along a straight line while wearing the system. The results reveal that compared to the young adults, older adults exhibited lower localized GRF contributions from the heel and greater localized GRF contribution from the toe and fifth metatarsal locations. Furthermore, the older adults exhibited greater variability in their stride length and smaller toe clearance with greater variability compared to the young adults. These results underscore the effectiveness of the proposed gait analysis system in distinguishing the gait characteristics of young and older adults, potentially replacing traditional motion capture systems and force plates in gait analysis.

Recent Advances in Electronic Structure Modifications of Layered Double Hydroxide (LDH) for the Water Splitting Application

AbstractElectrocatalytic water splitting is a feasible method for large‐scale hydrogen production. Recently, layered double hydroxides (LDH) have been identified as a possible candidate for accelerating the water splitting process. Nevertheless, certain structural alterations are necessary for immaculate LDH because of their weak electrocatalytic activity. These structural changes alter the local reaction environment by modulating the electronic structure of the metal center present in the LDH. This electronic structure tailoring is accomplished by a variety of processes, including heteroatom doping, single atom inclusion, cationic defect, oxygen vacancy creation, and heterostructure formation. Recently, there has been an uptick of advancement in this field, and it is necessary to summarize these developments. This review provides a concise summary of the current reports on the electronic structure manipulation of layered double hydroxide. The review begins by examining the local environmental changes of LDH resulting from the insertion of single atoms. Subsequently, we explore the charge transfer that occurs at the interface between LDH and other transition metal heterostructures. In addition, we explored the impact on the metal center near the vacancies on the basal plane of LDH. Finally, we presented a future perspective and guidance for advancing this field in electrocatalysis.

Ab initio molecular dynamics simulation reveals the influence of entropy effect on Co@BEA zeolite-catalyzed dehydrogenation of ethane

The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate. To understand the impact of entropy, we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures. AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased. Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction. The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels. We provided explanations consistent with the principles of thermodynamics and statistical physics. The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

A systematic review of lithium biology and pharmacology and toxicological evaluation of new organic lithium salts

Objective: to systematize scientific data on biomedical studies investigating trace element lithium over the past 70 years; evaluate toxic properties of lithium ascorbate (LiAsc) as an important promising candidate molecule.Material and methods. An analysis of 49,959 publications on lithium biomedical research retrieved from PubMed/MEDLINE database was carried out using modern data mining methods developed within the framework of topological approach to recognizing (Yu.I. Zhuravlev scientific school). Publications found by experts and not indexed in PubMed/MEDLINE were used in discussing the results of a systematic analysis of publications array retrieved from PubMed/MEDLINE. An experimental study of chronic 180 day-long LiAsc (at doses of 5, 50 and 150 mg/kg) toxicity was performed on 36 “Soviet chinchilla” rabbits by assessing local irritant action. Intoxication clinical picture, body weight dynamics, water and food intake as well as physiological, hematological and biochemical parameters were analyzed.Results. Classification and systematization of all currently available publications on lithium biology and medicine were performed. It was shown that pharmacological applications of lithium salts in mental disorders as well as lithium effects on simple sugars metabolism, lipid metabolism, blood pressure regulation, hematopoiesis, inflammation and tumor growth inhibition, neurotransmitter homeostasis, neurotrophic and neuroprotective molecular mechanisms as well as homeostasis of other electrolytes comprised promising fields of lithium drug research. The prospects for using organic lithium salts, particularly LiAsc, for various therapeutic goals were also discussed. 180-day-long oral administration of LiAsc at doses of 5, 50, 150 mg/kg resulted in no macroscopic signs of local inflammatory reaction while examining its local irritant effect.Conclusion. The lithium-ion effect on neurotransmitters promotes neuroprotection and reduces a risk of addiction. The antihypertensive, antiatherosclerotic, antidiabetic, antitumor and neurotrophic effects related to organic lithium salts may be beneficial in various therapeutic applications.

Interfacial Conductor-Modulated Low-Triggered Potential Electrochemiluminescence from Conjugated Polymers for Bioanalysis.

Polyfluorene and its derivatives (PFs) are extremely appealing electrochemiluminescence (ECL) illuminants thanks to their easy modification, high quantum yield, excellent photostability, and nontoxicity, exhibiting great application potential in ECL sensing and imaging. Unfortunately, most reported PFs-based ECL bioanalysis generally exhibited high triggering potential (>1.0 V vs Ag/AgCl), which introduced undesirable electrochemical interference to adversely affect the sensitivity and accuracy of biological analysis. This work innovatively exploited poly(3,4-ethylenedioxythiophene) (PEDOT) as an interfacial conductor to modulate the low ECL triggering potential of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadazole)] (PFBT) nanoparticles (NPs). The unique conductivity of in situ electrodeposited PEDOT promoted electron transfer between PFBT NPs and coreactant tripropylamine (TPrA), negatively shifting the ECL triggering potential of PFBT NPs from +1.22 to +0.78 V. The PFBT NPs/PEDOT coupled the localized hybridization chain reaction (LHCR) circuits to achieve a specific and sensitive ECL detection of malathion (MAL), and a low limit of detection (LOD) of 22 fg/mL was obtained. The interfacial conductor provides inspiration for creating the low ECL triggering potential. PFBT NPs-coupled PEDOT builds a low ECL triggering potential of the PFs-based platform for pesticide residue analysis with low interference and high sensitivity.

Efficacy and safety of topical glycopyrronium bromide in treating axillary hyperhidrosis: systematic review and meta-analysis

BackgroundHyperhidrosis (HH), characterized by excessive sweating, poses a significant challenge to patients’ quality of life. This meta-analysis evaluates the safety and efficacy of topical glycopyrronium bromide (GBP) in treating primary hyperhidrosis, a chronic condition affecting various body regions. Despite its prevalence, primary axillary hyperhidrosis is often undertreated due to a lack of awareness and social stigma.MethodsFollowing PRISMA guidelines, we conducted a systematic review and meta-analysis of randomized controlled trials comparing GBP to a placebo in primary hyperhidrosis patients. Eligibility criteria included outcomes related to perspiration suppression and symptom improvement.ResultsFour RCTs involving 1401 patients were included. GBP significantly increased Hyperhidrosis Disease Severity Scale (HDSS) responders (RR = 2.33, 95% CI [1.99 to 2.74], p < 0.00001) and Axillary Sweating Daily Diary (ASDD/ASDD-C) responders (MD = 3.07, 95% CI [2.32 to 4.06], p < 0.002) without significantly causing adverse events. Dermatology life quality index was also significantly improved in the GBP group (MD = -2.32, 95% CI [-3.09, -1.55], P < 0.00001).ConclusionGBP demonstrated effectiveness in reducing sweat production while improving HDSS and DLQI scores. Adverse events included dry mouth and anticholinergic effects. Dry eye and local skin reactions were not significant, which makes GBP promising in managing primary hyperhidrosis, offering improvements in symptoms and quality of life. While adverse events should be considered, further research with larger sample sizes and long-term follow-up is warranted for comprehensive clinical integration.

Safety Evaluation of the Novel Cocktail of Monoclonal Antibodies for Postexposure Prophylaxis in Category III Animal Exposures

Abstract Introduction: Rabies monoclonal antibody (mAb) is a life-saving immune-biological for postexposure prophylaxis (PEP) in all Category III animal exposures. A novel cocktail of mAbs derived using recombinant DNA technology is presently available for usage. The WHO recommends monitoring the clinical use and outcomes of mAb products. Methods: An open-label, postmarketing study was conducted at the anti-rabies clinic in the southern part of India. PEP was provided to all the study participants per the national guidelines. All the subjects were assessed for any adverse events (AEs) following PEP up to 35 days; if any, were treated free of cost at the study center. Results: The present study included 309 subjects across all age groups, 59.2% were adults, 33.3% of children, and 7.5% elderly. Majority of the patients were exposed to dogs (89.6%) and most of them had lacerations (86.3%) in different parts of their body. A total of 19 (6.2%) AEs were reported. All the AEs were local reactions, namely pain (2.6%), erythema (1.4%), tenderness (1%), induration (0.6%), and swelling (0.6%). All reported AEs were mild (Grade 1 severity) and resolved completely with symptomatic treatment. Conclusion: The novel cocktail of mAbs was safe for PEP in Category III animal exposures across all the age groups and supports its continued and improved usage for Universal Health Coverage to prevent rabies.

The Ambivalence of Post COVID-19 Vaccination Responses in Humans.

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has prompted a massive global vaccination campaign, leading to the rapid development and deployment of several vaccines. Various COVID-19 vaccines are under different phases of clinical trials and include the whole virus or its parts like DNA, mRNA, or protein subunits administered directly or through vectors. Beginning in 2020, a few mRNA (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) and adenovirus-based (AstraZeneca ChAdOx1-S and the Janssen Ad26.COV2.S) vaccines were recommended by WHO for emergency use before the completion of the phase 3 and 4 trials. These vaccines were mostly administered in two or three doses at a defined frequency between the two doses. While these vaccines, mainly based on viral nucleic acids or protein conferred protection against the progression of SARS-CoV-2 infection into severe COVID-19, and prevented death due to the disease, their use has also been accompanied by a plethora of side effects. Common side effects include localized reactions such as pain at the injection site, as well as systemic reactions like fever, fatigue, and headache. These symptoms are generally mild to moderate and resolve within a few days. However, rare but more serious side effects have been reported, including allergic reactions such as anaphylaxis and, in some cases, myocarditis or pericarditis, particularly in younger males. Ongoing surveillance and research efforts continue to refine the understanding of these adverse effects, providing critical insights into the risk-benefit profile of COVID-19 vaccines. Nonetheless, the overall safety profile supports the continued use of these vaccines in combating the pandemic, with regulatory agencies and health organizations emphasizing the importance of vaccination in preventing COVID-19's severe outcomes. In this review, we describe different types of COVID-19 vaccines and summarize various adverse effects due to autoimmune and inflammatory response(s) manifesting predominantly as cardiac, hematological, neurological, and psychological dysfunctions. The incidence, clinical presentation, risk factors, diagnosis, and management of different adverse effects and possible mechanisms contributing to these effects are discussed. The review highlights the potential ambivalence of human response post-COVID-19 vaccination and necessitates the need to mitigate the adverse side effects.

Probiotics as adjuvants to mitigate adverse reactions and enhance effectiveness in Food Allergy Immunotherapy.

In the past decades, food allergies became increasingly dominant since early childhood, leading to a lower quality of life and to increasing costs addressed by the health care system. Beside standard avoidance of specific allergens and drug treatments following allergen exposure, a great deal of research has lately focused on Food Allergy Allergen Immunotherapy (FA-AIT). SCIT and EPIT (Subcutaneous and Epicutaneous Immunotherapy), OIT (Oral Immunotherapy), and SLIT (Sublingual Immunotherapy) consist in gradual exposure to allergens to desensitize and achieve tolerance once therapy has ended. Although promising, FA-AIT may bring acute local and systemic adverse reactions. To enhance efficacy, safety and convenience of AIT, the quest of potential adjuvants to mitigate the adverse reactions becomes crucial. Immunomodulatory activities, such as that of increasing the regulatory T cells and decreasing the IgE, have been observed in specific probiotics' strains and multiple studies elucidated the role of gut microbiota as a major interplayer among the host and its immune system. In this review, the microbiome modulation is shown as potential AIT adjuvant, nevertheless the need of more clinical studies in the near future is pivotal to assess the efficacy of targeted bacterial therapies and faecal microbiota transplantation.

Numerical simulation for investigating crevice corrosion of carbon steel in neutral/alkaline concrete construction

Purpose This study aims to investigate the crevice corrosion behavior of carbon steel in neutral/alkaline environments utilizing a transient multi-physics field model. Design/methodology/approach The crevice corrosion of carbon steel with different solution pH and crevice width was modeled, incorporating mass transfer, homogeneous phase and localized electrochemical reactions. The extent of crevice corrosion was evaluated by the geometric deformation of the model mesh. The hydro-chemical state inside the crevice was discussed through the Cl− concentration and potential distribution of the solution. Findings Results revealed that the formation of pitting corrosion near the crevice mouth was accelerated in a neutral solution. When pH = 8 and pH = 9, the carbon steel matrix was dissolved and the Cl− content within the solution was significantly reduced due to the higher concentration of hydroxide ions (OH−). Originality/value The crevice corrosion behavior of carbon steel in neutral/alkaline environments is closely associated with solution pH rather than the crevice width. The inhibition of crevice corrosion in alkaline environments was proved by finite element simulation. These findings provide valuable insights that can be applied in engineering applications to prevent and mitigate crevice corrosion in neutral/alkaline environments.

Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: APilot Study on Swine.

Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene.

Epidermal Growth Factor Intralesional Delivery in Chronic Wounds: The Pioneer and Standalone Technique for Reversing Wound Chronicity and Promoting Sustainable Healing.

The early expectations about growth factors' (GFs') discovery as an undisputed therapeutic solution for chronic wounds progressively eclipsed when they failed to accelerate acute wound closure and restore the healing trajectory of stagnant ulcers. Critical knowledge about chronic wound biology and GF pharmacology was a conundrum at that time. Diabetes undermines keratinocytes' and fibroblasts' physiology, impairing skin healing abilities. Diabetic ulcers, as other chronic wounds, are characterized by hyperinflammation, unbalanced proteolytic activity, catabolism, and free radical cytotoxicity. This hostile scenario for the chemical stability, integrity, and functionality of GFs led to the conclusion that topical administration may jeopardize GFs' clinical effectiveness. Epidermal growth factor (EGF) has a proximal position in tissues homeostasis by activating survival and mitogenic pathways from embryonic life to adulthood. Seminal experiments disclosed unprecedented pharmacological bounties of parenterally administered EGF. Accordingly, the experience accumulated for more than 20 years of EGF intralesional infiltration of diabetic wound bottoms and edges has translated into sustained healing responses, such as low recurrences and amputation rates. This delivery route, in addition to being safe and tolerated, has shown to restore a variety of circulating biochemical markers ordinarily disturbed in diabetic conditions. EGF infiltration triggers a cascade of local fibroblast reactions, supporting its molecular integrity, prolonged mean residence time, and ultimately eliciting its receptor trafficking and nuclear translocation. The intralesional delivery route seems to warrant that EGF reaches wound fibroblasts' epigenetic core, mitigating the consequences of metabolic memory imprinting.

Breaking the mold: nontraditional approaches to allergen immunotherapy for environmental allergens.

Allergen immunotherapy is a disease-modifying treatment for allergic diseases. The predominant traditional immunotherapy is through subcutaneous administration of allergens to gradually desensitize allergic individuals. While effective, traditional allergen immunotherapy approaches are often lengthy, time consuming for patients and can result in local or systemic adverse reactions. Nontraditional immunotherapies are emerging as promising alternatives, offering potentially more convenient, safe and efficacious treatment options. This review sought to comprehensively examine the safety, efficacy and performance of various nontraditional immunotherapies for environmental allergens. Nontraditional immunotherapy approaches covered in this review include sublingual, local nasal, intralymphatic rush and ultra-rush immunotherapy, allergoid, microbial and anti-IgE immunotherapies. Nontraditional immunotherapies show significant promise in addressing the limitations of traditional subcutaneous immunotherapy. Methods like intralymphatic and rush immunotherapy offer shorter treatment regimens, enhancing patient adherence and convenience. The co-administration of probiotics or monoclonal antibodies, like omalizumab, with AIT appears to improve treatment efficacy and safety. Despite these advancements, further large-scale, long-term studies are needed to establish standardized protocols, dosing and validate long-term effects of these nontraditional immunotherapies. Standardizing outcome measurements across studies is crucial for accurate comparisons of nontraditional immunotherapies prior to widespread clinical adoption of these innovative techniques.

The developing immune system in preterm born infants: From contributor to potential solution for respiratory tract infections and wheezing.

Moderate-late preterm-born infants experience more frequent and severe respiratory tract infections and wheezing compared to term-born infants. Decreasing the risk on respiratory tract infections and wheezing in this group is vital to improve quality of life and reduce medical consumption during infancy, but also to reduce the risk on asthma and COPD later in life. Until now, moderate-late preterm infants are underrepresented in research and mechanisms underlying their morbidity are largely unknown, although they represent 80% of all preterm-born infants. In order to protect these infants effectively, it is essential to understand the role of the immune system in early life respiratory health and to identify strategies to optimize immune development and respiratory health. This review elaborates on risk factors and preventative measures concerning respiratory tract infections and wheezing in preterm-born infants, exploring their impact on the immune system and microbiome. Factors discussed are early life antibiotic use, birth mode, feeding type and living environment. Further, differences in adaptive and innate immune maturation between term and preterm infants are discussed, as well as differences in local immune reactions in the lungs. Finally, preventative strategies are being explored, including microbiota transplantation, immune modulation (through pre-, pro-, syn- and postbiotics, bacterial lysates, vaccinations, and monoclonal antibodies) and antibiotic prophylaxis.

Role of oxidative stress in the occurrence of periodontitis in the background of metabolically associated diseases

Oxidative stress is an important component of slow pathological inflammation in metabolic diseases and chronic periodontitis. Periodontal diseases are interrelated with somatic pathology. This results in both local and systemic inflammatory reactions, which increases the risk of the onset and progression of somatic diseases. Psychological stress associated with oxidative stress with increased production of oxidants and oxidative damage is an important factor in the etiology of both periodontitis and metabolic disorders. Objective — to analyze the possible bond between chronic periodontitis, 8‑hydroxydeoxyguanosine (8‑OHdG), as a biomarker of oxidative stress, and cortisol in persons with metabolic‑associated diseases. Materials and methods. 68 people were surveyed, of which 47 had metabolically ‑associated diseases that were diagnosed according to domestic and international criteria. The control group consisted of systematically healthy people, representative by age and article that did not receive dental therapeutic and preventive measures for the last 6 months. The diagnosis of «chronic periodontitis» was carried out in accordance with existing recommendations provided at World Workshop on the Classification of Periodontal and Peri­Implant Diseases and Conditions (2017). The concentration of 8‑OHdG in plasma and the level of saliva cortisol were measured by the immunoenzyme method according to the manufacturer’s instructions. The arithmetic mean, standard error, and Student’s t‑test were calculated to compare the characteristics. Pearson’s correlation test was used to identify the relationship between the indicators. Results. Each of the groups had patients who had a healthy periodontium and those who had chronic periodontitis. The 8‑OHdG level in the main group was much higher (p&lt;0.001) than in the control group, and the difference in the concentration of 8‑OHdG was also observed between those patients who had periodontal disease and those who had a healthy periodontium. The level of salivary cortisol in patients with chronic periodontitis was much higher compared to patients with clinically healthy periodontium (p=0.00). A correlation was found between cortisol levels and the presence of periodontal disease (r=0.619; p=0.00), between plasma 8OHdG levels and the epithelial attachment loss index (r=0.537; p=0.00), the hygiene index (r=0.599; p=0.00), and between 8OHdG levels and salivary cortisol concentrations (r=0.292; p=0.036). Conclusions. Oxidative stress plays an important role in delayed pathological inflammation in both metabolic diseases and chronic periodontitis. 8‑OHdG is a key and universal biomarker for the evaluation of DNA oxidative damage. There is a positive relationship between the oxidative marker, periodontitis and cortisol.

Novel Understanding of the Formation and Protectiveness of Corrosion Product Film on Ca–Sb–Cr Weathering Steel

The addition of Ca and Sb in Cr‐bearing steel presents improved corrosion resistance during the field exposure test in a marine atmosphere environment. Through local hydrolysis reactions, Ca and Sb can form CaO, Sb2O3, and Sb2O5 to prevent the intrusion Cl− into the corrosion product film, which improves the protectiveness of the corrosion product film and reduces the corrosion rate. The formation of CaCl2 decreases the relative content of β‐FeOOH and makes the corrosion product film more stable. Due to the inhibition of Sb on the local acidification of corrosion product film, Ca and Cr are able to bond with more hydroxide for generating the corresponding oxides and improving the corrosion resistance of Cr‐bearing steel.

9224 Evaluation of Safety and Efficacy of Administration of Estradiol by Subcutaneous Injection in Transgender Women

Abstract Disclosure: H. Perkins: None. H. Moreau: None. J. LaBudde: None. W. Craig: None. D.I. Spratt: None. Background: Off-label use of subcutaneous (SC) estradiol (E2) by transgender women for gender-affirming hormone therapy is becoming increasingly widespread, despite a lack of published data regarding its efficacy and safety. Methods: This retrospective cohort study used manual data extraction from electronic medical records for patients ages 18-79 years, currently or previously receiving oral (PO) 17-beta E2 or SC E2 valerate therapy at Maine Medical Center Reproductive Endocrinology and Infertility and Gender Clinics between 5/30/14-5/30/23, who completed E2 dose adjustments aimed at obtaining a serum E2 of 75-250 pg/mL. SC E2 was administered weekly and PO E2 daily. Serum testosterone (T), estrone (E1), and sex hormone binding globulin (SHBG) levels were recorded if drawn within 90 days of E2 measurement on an optimized dose. In a subset of patients receiving SC E2, serum E2 levels were drawn 1-2 days post- and pre-injection. All patient-reported local or systemic reactions were recorded. Data are expressed as median (full range) or mean ± standard deviation (full range). Results: 45 patients were included with no significant differences in demographics between PO (n=20) and SC (n=25) groups. Both groups achieved therapeutic E2 levels after dose adjustment without statistical difference in mean serum E2 (pg/mL) between SC and PO groups: 148.7 ± 41.0 (78-226) vs. 151.6 ± 31.7 (97-208); p=0.79 by t-test. In patients without orchiectomy, both SC and PO groups had T (ng/dL) suppressed to normal adult female range (10-55) in 11/12 SC patients and in 17/17 PO patients; median T was 14.0 (7.7-86) for SC vs. 20.6 (3.4-42) for PO; p=0.98 by Mann-Whitney U test. Median E2 dose (mg/week) in the SC group was 3.0 (1.4-6.0) and in the PO group was 42.0 (28-84). Median serum E1 (pg/mL) was lower in the SC group than the PO group: 73.5 (29-115), n=12 vs. 907 (596-1601), n=5, p&amp;lt;0.001 by Mann-Whitney U test. E1/E2 ratio was lower in the SC group than the PO group: 0.4 ± 0.1 vs. 8.0 ± 2.9; p&amp;lt;0.001 by t-test. There was no significant difference in median serum SHBG (nmol/L) between SC and PO groups: 71.7 (19.3-146.7), n=15 vs. 73.4 (51.0-187.4), n=14; p=0.20 by Mann-Whitney U test. Mean post- and pre-dose serum E2 levels in 5 patients were 138.0 ± 24.0 and 88.0 ± 57.6, respectively. There was one transient local reaction and no systemic allergic or inflammatory reactions in the SC group with no systemic reactions in the PO group. Conclusion: These results demonstrate that SC E2 at doses of 1.4-6 mg/week can be administered safely to achieve therapeutic serum E2 levels and suppress serum T levels to within the normal female range. Our preliminary data reveal lower serum E1 levels in the SC group than in the PO group suggesting reduced hepatic first-pass metabolism with SC administration; this pattern was not seen with serum SHBG levels. Post- and pre-dose serum E2 levels revealed only a mild decline in E2 levels between injections. Presentation: 6/3/2024

6961 Evaluation of Safety and Efficacy of Administration of Estradiol by Subcutaneous Injection in Transgender Women

Abstract Disclosure: H. Perkins: None. H. Moreau: None. J. LaBudde: None. W. Craig: None. D.I. Spratt: None. Background: Off-label use of subcutaneous (SC) estradiol (E2) by transgender women for gender-affirming hormone therapy is becoming increasingly widespread, despite a lack of published data regarding its efficacy and safety. Methods: This retrospective cohort study used manual data extraction from electronic medical records for patients ages 18-79 years, currently or previously receiving oral (PO) 17-beta E2 or SC E2 valerate therapy at Maine Medical Center Reproductive Endocrinology and Infertility and Gender Clinics between 5/30/14-5/30/23, who completed E2 dose adjustments aimed at obtaining a serum E2 of 75-250 pg/mL. SC E2 was administered weekly and PO E2 daily. Serum testosterone (T), estrone (E1), and sex hormone binding globulin (SHBG) levels were recorded if drawn within 90 days of E2 measurement on an optimized dose. In a subset of patients receiving SC E2, serum E2 levels were drawn 1-2 days post- and pre-injection. All patient-reported local or systemic reactions were recorded. Data are expressed as median (full range) or mean ± standard deviation (full range). Results: 45 patients were included with no significant differences in demographics between PO (n=20) and SC (n=25) groups. Both groups achieved therapeutic E2 levels after dose adjustment without statistical difference in mean serum E2 (pg/mL) between SC and PO groups: 148.7 ± 41.0 (78-226) vs. 151.6 ± 31.7 (97-208); p=0.79 by t-test. In patients without orchiectomy, both SC and PO groups had T (ng/dL) suppressed to normal adult female range (10-55) in 11/12 SC patients and in 17/17 PO patients; median T was 14.0 (7.7-86) for SC vs. 20.6 (3.4-42) for PO; p=0.98 by Mann-Whitney U test. Median E2 dose (mg/week) in the SC group was 3.0 (1.4-6.0) and in the PO group was 42.0 (28-84). Median serum E1 (pg/mL) was lower in the SC group than the PO group: 73.5 (29-115), n=12 vs. 907 (596-1601), n=5, p&amp;lt;0.001 by Mann-Whitney U test. E1/E2 ratio was lower in the SC group than the PO group: 0.4 ± 0.1 vs. 8.0 ± 2.9; p&amp;lt;0.001 by t-test. There was no significant difference in median serum SHBG (nmol/L) between SC and PO groups: 71.7 (19.3-146.7), n=15 vs. 73.4 (51.0-187.4), n=14; p=0.20 by Mann-Whitney U test. Mean post- and pre-dose serum E2 levels in 5 patients were 138.0 ± 24.0 and 88.0 ± 57.6, respectively. There was one transient local reaction and no systemic allergic or inflammatory reactions in the SC group with no systemic reactions in the PO group. Conclusion: These results demonstrate that SC E2 at doses of 1.4-6 mg/week can be administered safely to achieve therapeutic serum E2 levels and suppress serum T levels to within the normal female range. Our preliminary data reveal lower serum E1 levels in the SC group than in the PO group suggesting reduced hepatic first-pass metabolism with SC administration; this pattern was not seen with serum SHBG levels. Post- and pre-dose serum E2 levels revealed only a mild decline in E2 levels between injections. Presentation: 6/3/2024