Additional Dose Research Articles

Systematic study on the influence of inductive chargers on active personal dosemeters

Electromagnetic compatibility testing plays an important role in the type testing of radiation protection dosemeters in view of technical developments and the associated increase in electromagnetic fields. Lately, the use of inductive charging devices has grown as a user-friendly type of charging mobile-phones. In this article, we investigate their impact on active personal dosemeters (APD). The measurements show a substantial additional dose reading of up to several tens of mSv when exposed to the field of an inductive charger for 20 s. According to the widely used Qi standard, the charging devices operate at frequencies of between 87 kHz and 205 kHz for power transfers between 5 W and 30 W. These parameters fall outside the scope of type-testing standards for APD. An update of the standards might therefore be necessary.

Surrogate gating strategies for the Elekta Unity MR-Linac gating system.

MRI-guided adaptive radiotherapy can directly monitor the anatomical positioning of the intended target during treatment with no additional imaging dose. Elekta has recently released its comprehensive motion management (CMM) solution that enables automatic radiation beam-gating on the Unity MR-Linac. Easily visualized targets that are distinct from the surrounding anatomy can be used to drive automatic gating decisions from the MRI cine imaging. However, poorly visualized targets can compromise the tracking and gating capabilities and may require surrogate tracking structures. This work presents strategies to generate robust tracking surrogates for a variety of treatment sites, enabling a wider application of CMM. Surrogate tracking strategies were developed from a cohort of patients treated using the CMM system on the Unity MR-Linac for treatment sites of the lung, pancreas, liver, and prostate. These sites posed challenging visualization or tracking of the primary target thereby compromising the tracking accuracy. Surrogate structures were developed using site-specific strategies to improve the imaging textured detail within the tracking volume while avoiding the dynamic overwhelming hypo- or hyper-intense anatomical structures. These surrogate volumes were applied within the anatomical positioning monitoring system as a proxy that drove the CMM gating decisions on the treatment unit. Robust site-specific surrogate structures were developed. Surrogate tracking structures for centrally located thoracic targets were created by expanding the target peripherally away from the heart and great vessels and into the lung. Pancreas surrogates required a vertically expanded column intersecting with the inferior liver edge. For the liver and prostate, surrogate structures consisted of a uniform expansion of the target, with liver surrogates intersecting the proximal liver edge or diaphragm while avoiding nearby ribs. These surrogate strategies have enabled the gating of complex moving targets among different treatment sites at our institution.

Comparison of antibody responses of heterologous and homologous Covid-19 booster vaccination: an observational study

ObjectivePakistan has been seriously affected by the COVID-19 pandemic, with numerous waves of infection. Using different vaccine and booster doses was a key component to control and combat this pandemic. This study aims to monitor the heterologous and homologous booster vaccination doses that generate immune responses in healthy adults after 9 months of vaccination.MethodsIn this cross-sectional, observational study a total of 173 samples were collected. Participants from both genders (Male and Female) between the ages of 18 to 25 years were enrolled for the study. Participants who had booster shots of homologous Sinopharm BBIBP CorV and heterologous Pfizer-BioNTech vaccines were included only, with the use of a Roche Cobas-e601 analyzer, the antibody titers in the blood serum were quantified by the ECLIA method. IBM SPSS 22 was utilized for descriptive statistical analysis and P< 0.05 was considered significant.ResultsIn this study the IgG antibody levels were measured against the full length of receptor binding domain (RBD) of the spike (S) protein. The mean antibody titer in the Pfizer group was 9764 ± 10976 U/mL and 5762 ± 4302 U/mL in the Sinopharm group. The Mean IgG antibody levels of the Pfizer-vaccinated group were significantly higher than the Sinopharm-vaccinated group (P=0.000, each). Comparing the Sinopharm BBIBP CorV booster dosage to the Pfizer booster, Pfizer BNT162b2demonstrated a stronger immune response. However, there were no immunological gender-specific significant differences. The administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP CorVConclusionThe administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP-CorV is recommended to boost the humoral immune response in the general population while there was no gender-specific difference observed. More effectiveness can be attained by administering additional doses due to the antibody decay.

From Tissue to System: What Constitutes an Appropriate Response to Loading?

Optimal loading involves the prescription of an exercise stimulus that promotes positive tissue adaptation, restoring function in patients undergoing rehabilitation and improving performance in healthy athletes. Implicit in optimal loading is the need to monitor the response to load, but what constitutes a normal response to loading? And does it differ among tissues (e.g., muscle, tendon, bone, cartilage) and systems? In this paper, we discuss the "normal" tissue response to loading schema and demonstrate the complex interaction among training intensity, volume, and frequency, as well as the impact of these training variables on the recovery of specific tissues and systems. Although the response to training stress follows a predictable time course, the recovery of individual tissues to training load (defined herein as the readiness to receive a similar training stimulus without deleterious local and/or systemic effects) varies markedly, with as little as 30min (e.g., cartilage reformation after walking and running) or 72h or longer (e.g., eccentric exercise-induced muscle damage) required between loading sessions of similar magnitude. Hyperhydrated and reactive tendons that have undergone high stretch-shorten cycle activity benefit from a 48-h refractory period before receiving a similar training dose. In contrast, bone cells desensitize quickly to repetitive loading, with almost all mechanosensitivity lost after as few as 20 loading cycles. To optimize loading, an additional dose (≤ 60 loading cycles) of bone-centric exercise (e.g., plyometrics) can be performed following a 4-8h refractory period. Low-stress (i.e., predominantly aerobic) activity can be repeated following a short (≤ 24h) refractory period, while greater recovery is needed (≥ 72h) between repeated doses of high stress (i.e., predominantly anaerobic) activity. The response of specific tissues and systems to training load is complex; at any time, it is possible that practitioners may be optimally loading one tissue or system while suboptimally loading another. The consideration of recovery timeframes of different tissues and systems allows practitioners to determine the "normal" response to load. Importantly, we encourage practitioners to interpret training within an athlete monitoring framework that considers external and internal load, athlete-reported responses, and objective markers, to contextualize load-response data.

The influence of daily imaging and target margin reduction on secondary cancer risk in image-guided and adaptive proton therapy

Objective. Image-guided and adaptive proton therapy rely on daily CBCT or CT imaging, which increases radiation dose and radiation-induced cancer risk. Online adaptation however also reduces setup uncertainty, and the additional risk might be compensated by reducing the setup robustness margin. This work developed a framework to investigate how much this robustness margin should be reduced to offset the secondary cancer risk from additional imaging dose and applied it to proton therapy for head-and-neck cancer.Approach. For five patients with head-and-neck cancer, voxel-wise CT and CBCT imaging doses were estimated with Monte Carlo radiation transport simulations, calibrated with air and PMMA phantom measurements. The total dose of several image-guided and adaptive treatments protocols was calculated by summing the planning CT dose, daily and weekly CBCT or CT dose, and therapy dose, robustly optimized with setup margins between 0 and 4 mm. These were compared to a reference protocol with 4 mm setup margin without daily imaging. All plans further used 3% range robustness. Organ-wise excess absolute risk (EAR) of cancer was calculated with three models to determine at which setup margin the total EAR of image-guided and adaptive treatment protocols was equal to the total EAR of the reference.Results. The difference between the simulated and measured CT and CBCT doses was within 10%. Using the Monte Carlo models, we found that a 1 mm setup margin reduction was sufficient for most patients, treatment protocols, and cancer risk models to compensate the additional risk imposed by daily and weekly imaging. For some protocols, even a smaller reduction sufficed, depending on the imaging frequency and type. The risk reduction by reducing the margin was mainly due to reducing the risk for carcinomas in the brain and, for some patients, the oral cavity.Significance. Our framework allows to compare an increased imaging dose with the reduced treatment dose from margin reductions in terms of radiation-induced cancer risk. It is extendable to different treatment sites, modalities, and imaging protocols, in clinic-specific or even patient-specific assessments.

CTIM-03. IMMUNE CHECKPOINT INHIBITOR NIVOLUMAB IN PEOPLE WITH RECURRENT SELECT RARE CNS CANCERS: RESULTS OF INTERIM ANALYSIS IN A NON-HEAVILY PRETREATED COHORT

Abstract BACKGROUND There is a paucity of salvage therapies for patients with rare CNS tumors. Nivolumab (PD-1 inhibitor) is approved for a variety of systemic cancers. We developed a multisite basket Phase II trial to evaluate Nivolumab for patients with recurrence of one of 12 selected rare CNS cancers. Efficacy is measured by Disease Control Rate (DCR; confirmed CR/PR or durable SD for ≥ 6 months) in 2 cohorts: heavily and non-heavily pretreated (≥ 3 prior therapies, vs. ≤ 2; including radiation and/or standard or experimental drugs). Cohort 1 has been completed. We report efficacy results and safety data of a preplanned interim analysis in Cohort 2 (non-heavily pretreated). METHODS In addition to progressive disease, eligibility includes available tumor tissue; age ≥ 18; KPS ≥ 70; no steroids at trial entry. Planned accrual: 75 in each cohort. Nivolumab dose: 240 mg IV every 2 weeks (4 doses), followed by 480 mg every 4 weeks (14 additional doses). Interim analysis was planned when the sample size reached 32 in each cohort. RESULTS As of December 1, 2023, among 27 evaluable patients treated in the non-heavily pretreated cohort, 10 achieved SD ≥ 6 months (DCR 37%; 95% CI 19.4%,57.6%) – 6 high-grade meningiomas; 1 each: myxopapillary ependymoma with lung metastases; solitary fibrous tumor, gliomatosis (astrocytoma IDH mutant WHO grade 2), chordoma. A total of 56 Grade 3-5 AEs occurred; 13 (Grade 3-4) related to nivolumab, including Grade 3 gait disturbance (3); cerebral edema, cognitive disturbance, colitis, headache, hypotension, hypoxia, lymphopenia, pain, and pruritus (1 each), and one Grade 4 cerebral edema. The three Grade 5 AEs were disease-related. CONCLUSION Preliminary efficacy analysis exceeded the “go” boundary (i.e., > 5 responders) in the non-heavily pretreated cohort. Nivolumab showed an acceptable safety profile. Cohort 2 will continue to complete a planned accrual of 75 patients.

CTNI-76. A PHASE 1/2 DOSE ESCALATION AND EXPANSION STUDY OF SONODYNAMIC THERAPY WITH SONALA-001 IN COMBINATION WITH NON-ABLATIVE MR-GUIDED FOCUSED ULTRASOUND IN SUBJECTS WITH PROGRESSIVE OR RECURRENT GLIOBLASTOMA

Abstract Recurrent glioblastoma (rGBM) is a lethal brain tumor with no effective standard of care option and an extremely poor prognosis (median survival 6 to 8 months after first recurrence). Sonodynamic therapy (SDT) is a non-invasive combination therapy that utilizes a drug, aminolevulinic acid HCL (SONALA-001, ALA), and a device, the Exablate 4000 Type 2.0 to deliver MR-guided focused ultrasound (MRgFUS). Preclinical studies have shown that SDT activates protoporphyrin IX (PpIX) to generate reactive oxygen species that lead to tumor cell death and improved survival in animal glioma models. A first-in-human Phase 0 trial (NCT04559685) indicated that ALA SDT was well-tolerated and not associated with off-target cellular or radiographic effects and provided direct evidence of reactive oxygen species formation and targeted tumor cell death in recurrent high-grade glioma (rHGG). SDT-202 is a Phase 1/2 multicenter, open-label, dose escalation and expansion study (NCT05370508) of iv SONALA-001 (ALA) in combination with MRgFUS for SDT in patients with progressive or recurrent GBM. Dose escalation will include an initial drug and energy dose escalation of ALA SDT utilizing an accelerated titration design with single subject cohorts for dose level cohorts 1 and 2, followed by cohort 3 with 3 + 3 design for additional dose escalation. SONALA-001 is administered 6 to 9 hours prior to MRgFUS treatment. Once the RP2D is determined, Phase 2 dose expansion will enroll approximately 36 additional subjects to assess safety and efficacy of repeated cycles of ALA SDT at the optimized RP2D. Endpoints of this study are safety evaluation, maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and determination of pharmacokinetic (PK) parameters. The Phase 2 portion will further characterize safety of RP2D along with evaluation of efficacy with PFS6 (mRANO), ORR, CBR, DOR, DOCR, TTR, and OS. Preliminary PK and safety results will be presented.

INNV-25. POST-OPERATIVE LOW DOSE VERSUS STANDARD DOSE DEXAMETHASONE FOR MANAGEMENT OF CEREBRAL EDEMA: A RANDOMIZED, DOUBLE-BLINDED FEASIBILITY STUDY IN PATIENTS WITH PRIMARY OR METASTATIC BRAIN TUMORS UNDERGOING CRANIOTOMY FOR TUMOR RESECTION

Abstract INTRODUCTION Although dexamethasone is effective for controlling cerebral edema during the peri-operative period, its immunosuppressive properties can inhibit responses to immunotherapy. We hypothesized that patients with mild to moderate cerebral edema could be safely managed post-operatively with lower doses of dexamethasone. METHODS Eligible patients with brain tumors who had less than 10 mm of midline shift on their pre-operative brain MRIs were randomized 1:1 to the standard or low dose dexamethasone arm, each tapering double blinded through post-op day 8. The double blind was maintained using equivalent volumes for IV doses and capsules containing dexamethasone or placebo. By post-op day 9, participants received the same dose of dexamethasone and continued tapering to off by day 14. Additional doses of dexamethasone were allowed if needed, based on specified symptom criteria. Lack of feasibility was defined as a participant requiring 18 mg or more of dexamethasone in addition to the planned total dose of dexamethasone (low dose: 49 mg; standard dose: 112 mg). Brain MRIs were performed on post-operative days 1, 3, and 8 to evaluate changes in cerebral edema. Manual segmentation and computer-assisted techniques were used to quantitatively measure cerebral edema volume. RESULTS Twenty-six patients were randomized and treated within tumor type strata (primary versus metastatic), of which 25 were evaluable. None of the participants on the low dose dexamethasone arm met the criteria for lack of feasibility. The quantitative assessment of differences in cerebral edema between the arms is ongoing and will be presented. CONCLUSIONS Administration of lower doses of dexamethasone post-operatively to brain tumor patients with mild to moderate cerebral edema is feasible. Treatment with lower doses of dexamethasone post-operatively should be considered in this patient population when peri-operative administration of immunotherapy is planned.

Assessing the efficacy of sugammadex based on ideal body weight for reversal of moderate neuromuscular blockade in obstetric patients across different BMI categories: A prospective study

Background: This investigation aimed to evaluate the effectiveness of administering 2 mg/kg intravenous (IV) sugammadex, dosed according to the ideal body weight (IBW) of obstetric patients across three different BMI groups, for the reversal of neuromuscular blockade caused by rocuronium.Materials and Method: A total of ninety female patients, who were categorized as American Society of Anesthesiologists (ASA) II and were 18 years or older, participated in this study. These patients were all scheduled to undergo elective cesarean sections under general anesthesia, providing a well-defined cohort for our investigation. Participants were separated into three groups according to their BMI: Group 1 (n=30) consisted of patients with a BMI less than 30 kg/m², Group 2 (n=30) included those with a BMI ranging from 30 to 39.9 kg/m², and Group 3 (n=30) comprised patients with a BMI over 40 kg/m². At the end of the surgery, each patient received intravenous sugammadex at 2 mg/kg based on ideal body weight, with additional doses as needed, while recording the total amount administered and the times for extubation, motor responses, and first breastfeeding.Results: The total sugammadex dose was found to be notably higher in Group 3 (p=0.002). The time required to reach a Train of Four (TOF) ratio greater than 90% was similar across the groups (p=0.120). However, the recorded durations between sugammadex administration and extubation, accurate motor response, and the time to first breastfeeding significantly differed between the groups.Conclusions: We found that IV sugammadex 2 mg/kg, administered according to the IBW of patients, was effective for reversing moderate neuromuscular blockade in patients of weight categories. However, administering a sugammadex dose of IBW+25% appears to be safer for class III obese patients.

Comparative analysis of fetal dose sparing between a C-arm linac and an O-ring linac in a SIB-VMAT sarcoma treatment for a pregnant patient: A technical note and case report.

To compare the effect of two linacs designs on fetal dose sparing on a pregnant patient, including estimation of the fetal dose, and the effect of a lead apron. A patient with a high-grade sarcoma located in the right knee/lower thigh was prescribed 51Gy (1.7Gy/Fx) with a simultaneous-integrated-boost (SIB) of 60Gy to a smaller volume, starting in the 26thgestational week. Volumetric modulated radiation therapy (VMAT) plans with 6MV-FFF were developed using identical dosimetric constraints on a Varian Truebeam Edge with HD-MLC and a Varian Halcyon with double-stacked MLC. Based on patient dimension measurements, an anthropomorphic phantom was constructed using a Rando phantom and saline bags in the patient's Vac-Lok bag. Phantom measurements were performed using OSLDs and TLDs placed at three different planes, corresponding to the pubis, the umbilicus, and the fundus based on patient measurements and projected gestational age, to estimate the fetal dose. Three experimental scenarios were measured, each with CBCT-based image guidance for an accurate, reproducible setup: Edge, Halcyon, and Halcyon with a tri-folded lead apron (0.5mm×3=1.5mmPb) over the phantom abdomen. Plan quality and total MUs are comparable between the Edge and Halcyon plans. The OSLD-measured whole-course dose to the pubis, umbilicus, and fundus were 18.8, 13.1, and 11.7 cGy, respectively, on Halcyon, on average 27.8% lower than Edge. The repeatability within either dosimeter was good, although TLD showed systematically lower doses. Importantly, both dosimetry systems showed a lower measured fetal dose for the Halcyon plan compared with the Edge plan. Adding a tri-folded lead apron over the abdomen did not meaningfully lower the measured dose. In this case study, Halcyon demonstrated a better sparing of out-of-field fetal dose compared to TrueBeam Edge. It was shown that lead aprons do not provide additional fetal dose sparing.

Safety and Feasibility of Interventional Hybrid Fluoroscopy and Nuclear Imaging in the Work-up Procedure of Hepatic Radioembolization.

Purpose To evaluate the safety and feasibility of a novel hybrid nuclear and fluoroscopy C-arm scanner to be used during the work-up procedure of hepatic radioembolization. Materials and Methods In this prospective first-in-human clinical study, 12 participants (median age, 67 years [range: 37-78 years]; nine [75%] male, three [25%] female) with liver tumors undergoing work-up for yttrium 90 radioembolization were included (ClinicalTrials.gov NCT06013774). Work-up angiography and technetium 99m-macroaggregated albumin injection were performed in an angiography suite equipped with a hybrid C-arm that could simultaneously perform fluoroscopy and planar nuclear imaging. Technetium 99m-macroaggregated albumin was injected under real-time hybrid imaging, followed by in-room SPECT imaging. Safety and feasibility were studied by assessing adverse events, technical performance, additional x-ray radiation dose, and questionnaires completed by radiologists and technologists. Results No adverse events were attributed to the hybrid C-arm scanner. The additional x-ray radiation dose was low (median, 19 Gy · cm2; minimum: 12 Gy · cm2; maximum: 21 Gy · cm2 for participants who completed all imaging steps). The interventional personnel considered use of the hybrid C-arm scanner safe and feasible, although the additional time spent in the intervention room was considered long (median, 64 minutes; minimum: 55 minutes; maximum: 77 minutes for participants who completed all imaging steps). Conclusion Use of the hybrid C-arm scanner during the work-up procedure of hepatic radioembolization was found to be safe and feasible in this first-in-human clinical study. Keywords: Angiography, Fluoroscopy, Interventional-Vascular, Radionuclide Studies, Radiosurgery, Gamma Knife, Cyberknife, SPECT, Instrumentation, Physics, Technical Aspects, Technology Assessment Supplemental material is available for this article. Published under a CC BY 4.0 license. Clinical trial registration no. NCT06013774.

Heterologous Versus Homologous COVID-19 Boosters: Immune Response Outcomes in Renal Transplant Recipients.

We aimed to investigate the immune responses to homologous and heterologous COVID-19 booster vaccinations in renal transplant recipients (RTRs) and to identify factors affecting these responses. In this prospective multicenter observational study, we measured the antibody kinetics of 90 RTRs using the chemiluminescent microparticle immunoassay method. The mean age of participants was 45.2 ± 11.4 years, with 35.6% being female. On the 42nd day after the first vaccine dose, the median antibody level was 16.7 (IQR 2.5-249.5) AU/mL, and the seropositivity rate was 60% (n = 36). Mycophenolic acid (MFA) (OR: 0.087, 95% CI: 0.024-0.311) and ACE inhibitor use (OR: 0.203, 95% CI: 0.052-0.794) were identified as independent factors affecting seropositivity. Patients who received the Pfizer/BioNTech booster had significantly higher antibody levels compared to those who received the CoronaVac/Sinovac booster (p = 0.021). Additionally, a significantly higher rate of COVID-19 positivity was observed among patients who received the CoronaVac/Sinovac booster (p = 0.031). Heterologous COVID-19 booster vaccination is significantly more effective than homologous inactivated booster vaccination in enhancing immune responses and preventing new infections in RTRs. MFA and ACE inhibitor usage were independent factors affecting seropositivity. Additional COVID-19 vaccine doses are needed in this patient group.

Single dose vs prolonged antibiotic prophylaxis of fosfomycin for transrectal prostate biopsy: a single-center prospective, randomized, controlled trial

BackgroundTransrectal prostate biopsy is a commonly performed urological procedure in which antibiotic prophylaxis is recommended. Fluoroquinolone-type antibiotics are no longer acceptable in the EU. Fosfomycin-trometamol may be used, but there is no evidence regarding its ideal dose and administration time. MethodsPatients who underwent prostate biopsy between 2021 and 2023 were evaluated prospectively. 204 patients were randomized into two arms: 102 patients (Arm A) received a single dose of fosfomycin-trometamol one hour before surgery, and 102 patients (Arm B) received one additional dose of fosfomycin-trometamol 48 hours after the first dose. Urine tests and questionnaires were administered during the postoperative period and the subsequent four weeks to identify any symptoms, infectious, or other complications. ResultsThere was no statistical difference in the rate of asymptomatic bacteriuria (4.90% (5) vs 8.82% (9), p = 0.27) symptomatic UTI (0% (0) vs 1.96% (2), p = 0.50), or febrile UTI (0% (0) vs 0.98% (1), p = 1) between the groups. Only haematuria was significantly more common in Arm B (6.86% (7) vs 16.67% (17), p = 0.03), whereas other complications did not differ significantly. There was no statistical difference in hospitalization (0.98% (1) vs 2.94 (3), p = 0.62) or mortality rate (0 % (0) vs 0.98% (1), p = 1). Sub-group analysis of previous antibiotic users showed no difference in terms of complications. ConclusionThere is no significant difference in infectious complications between single dose and prolonged prophylaxis of fosfomycin-trometamol for transrectal prostate biopsy. A single dose of fosfomycin one hour before biopsy is an ideal choice with a better ecological impact compared with prolonged antibiotic prophylaxis for transrectal prostate biopsy.

Bispectral Index-Monitored Anesthesia Induction in Older Adults Undergoing Elective Surgery: Comparing Ciprofol and Propofol in a Prospective, Single-Center, Double-Blind, Randomized Controlled Study.

Ciprofol, a new sedative anesthetic developed in China, offers rapid onset and recovery, reduced injection pain, and stable circulation. However, its effect on blood pressure during anesthesia induction in older adults remains unclear. To compare the effects of propofol and ciprofol on hypotension induced by general anesthesia in older adults. This prospective, single-center, double-blind, randomized, controlled clinical study enrolled 117 older adults undergoing surgery. Patients in the ciprofol group (group C) received an intravenous injection of ciprofol (0.3 mg/kg, n=57), while the propofol group (group P) received an intravenous injection of propofol (1.5 mg/kg, n=58). The primary outcome was the incidence of hypotension (mean arterial pressure (MAP) decreased by > 30% from baseline or MAP< 65mmHg). Secondary outcomes included induction success rate (bispectral index (BIS) value ≤60 and Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) score ≤1), injection pain, number of drug additions, time to BIS 60, time to eyelash reflex disappearance, blood pressure changes, incidence of hypertension, tachycardia and BIS values before and after administration. The incidence of induced hypotension was 26.3% (15/57) in group C and 48.3% (28/58) in group P (OR=0.383, 95% CI:175-0.837, P =0.015). Group C had significantly lower injection pain incidence (5.3% vs 20.7%, OR=0.213, 95% CI: 0.057-0.801, p=0.014). Both groups had a 100% induction success rate, with no significant difference in the number of additional doses. Post-intubation hypertension and tachycardia incidence were not significantly different. Group C showed less blood pressure decrease during induction and a deeper anesthesia level. Compared to propofol, ciprofol reduces the incidence of induced hypotension in older adults and maintains more stable blood pressure during induction. Additionally, ciprofol reduces injection pain and provides a good depth of anesthesia, making it a safe and effective option for anesthesia induction in older adults. ChiCTR2200066053.

Thermal stability of the bleachable and unbleachable components of the ESR signals in sedimentary quartz

The thermal stability of the bleachable and unbleachable components of the electron spin resonance signals in quartz grains from modern fluvial sediments were investigated. It was found that the unbleachable Al center is thermally more stable than the bleachable component, hence the unbleachable component can be extracted by heating. Protocols for equivalent dose evaluation with preheating are proposed, in which the procedure of bleaching is replaced by “partial annealing” (heating at 280 °C for 15 minutes) for the Al center and by “annealing” (heating at 400 °C for 1 hour) for the Ti-Li and Ti-H centers. The dose recovery test confirmed that the proposed protocol works practically, and that the regenerative protocol is better than the additive dose protocol in the aspect of the statistical errors. Appropriate partial annealing conditions to extract the unbleachable Al centers may need to be investigated for each sample.

Determinants of protective humoral response to mRNA-1273 and BNT162b2 vaccines in peritoneal dialysis patients: a prospective cohort study

Patients with chronic kidney disease (CKD) on dialysis have a higher mortality rate associated with SARS-CoV-2 infection. Although vaccines are now available, the protective response rates and determinants of humoral response to the vaccine are poorly described in patients on peritoneal dialysis. This was a prospective observational study describing the response rates of detectable and standardized protective antibody titers one month after each mRNA vaccine dose in a cohort of 88 patients on peritoneal dialysis. We found that the vast majority of patients produced protective levels of antibodies (73%) one month after the second vaccine dose. In the multivariate analysis, the single determinant for an adequate humoral response was the weekly Kt/V, a surrogate of dialysis dose. The response rate was higher, but not significantly, with the mRNA-1273 than with the BNT162b2 vaccine one month after the second dose (78.7 vs. 46.2%, respectively, p = 0.02). We found that patients on peritoneal dialysis had a satisfactory humoral response rate, which was much higher than in transplant recipients. PD patients with a poor humoral response, particularly those with a low wKT/V, may benefit from an additional dose of vaccine.

Impact of Treatment on Rate of Biphasic Reaction in Children with Anaphylaxis

Objective: Our goal was to characterize a large group of children presenting to the emergency department (ED) with acute anaphylaxis, treated with intramuscular epinephrine (IM EPI) and a corticosteroid (CS), and to determine the impact of pharmacologic intervention on the rate and timing of biphasic reactions (BPR). Methods: We reviewed consecutive children diagnosed with acute anaphylaxis managed in three EDs during a six-year period. All received IM EPI and CS, followed by monitoring for 4–6 hours post-treatment. We analyzed the rate and timing of BPR, comparing the intervals of 0–4vs4–48 hours after initiating therapy. Results: During the study period, there were 371 cases of anaphylaxis, of which 357 (94%) received both IM EPI and CS. Of these, 49 (14%) manifested BPR [84% had received prehospital IM EPI] requiring at least one additional dose of IM EPI [14% required ≥2 additional doses]. All BPR episodes occurred within the 0–4 hour interval after initiating therapy, whereas no patient manifested a BPR requiring an additional dose of IM EPI during the 4–48 hours after initiating therapy (P =&amp;lt;0.001, 95% CI 0–1.3%). No patient returned to the ED with recurrence of anaphylaxis symptoms within 48 hours after discharge. Conclusion: Approximately 1 in 7 children with anaphylaxis experience a biphasic reaction after receiving intramuscular epinephrine. Children with anaphylaxis who exhibit symptomatic resolution four hours following initiation of therapy have a low risk for subsequently developing BPR. Most BPR cases required only one additional dose of IM EPI to effect resolution. The rate of BPR in those receiving IM EPI and a corticosteroid is significantly lower &amp;gt;4 hours vs &amp;lt;4 hours after initiating therapy.

Biochar affects soil properties over 1 m depth in an alkaline soil of north China Plain

Biochar has been shown to enhance soil quality and agricultural yields. Previous studies about biochar's effect on soil properties mainly concentrated on the top 30 cm layer but less on the subsoils. Given the subsoil's active role in climate change mitigation and its significance for nutrient cycling and crop productivity, understanding biochar's effects at depth is crucial. This study explored the responses of soil organic carbon (SOC), total nitrogen, available potassium, available phosphorus, pH, and electrical conductivity to different doses of biochar addition (0, 10, 20, and 30 Mg/ha) over the 1 m depth of alkaline soil. Additionally, the impact of biochar on soil microbial community was assessed in the top 20 cm. Results demonstrated that biochar addition can increase SOC and improve soil properties in deep soil horizons. Specifically, a 30 Mg/ha biochar addition increased SOC by 1.2–10.1 Mg C/ha in the 10–40 cm layer and by 3 Mg C/ha in the 60–80 cm depth over two years. Additionally, biochar addition at this rate increased total nitrogen by 0.2–0.3 g N/kg in the 10–40 cm depth and elevated available potassium across the 1 m profile, with a maximum increment of 313 mg/kg in the surface 10 cm and a minimum of 97 mg/kg in the 40–60 cm depth. While biochar application did not increase available phosphorus, it resulted in a minor decrease in soil pH (<0.7 units) and a slight increase in electrical conductivity. Moreover, biochar addition did not significantly alter the soil microbial community. Our findings underscore the importance of considering subsoils when evaluating biochar's impact on soil properties. We suggest that subsoils should be considered when estimating the potential of cropland management for increasing soil carbon sequestration and improving soil conditions.

Prehospital seizure management protocols need standardized guidelines. A descriptive study from Norway

BackgroundPatients with convulsive seizures constitute a significant group in acute neurology. No common European clinical practice guidelines on prehospital seizure management exist, and today most patients are brought to hospital for seizure treatment, with great variation in which prehospital treatment is provided. Only 33 % of status epilepticus patients receive a benzodiazepine as first anti-seizure medication (ASM). The aim of this study is to assess the prehospital seizure control protocols in the Emergency Medical Services (EMS) in Norway, and compare these with current evidence for acute management. MethodWe performed a descriptive analysis of the 18 regional EMS protocols in Norway and compared the findings with recent evidence on prehospital treatment. We analysed recommended drug and dosage, route of medication administration, number of additional rescue doses permitted, requirements for registration of type of seizures and seizure duration. ResultsThe protocols vary in terms of preferred medication, administration method, dosage and recommendations regarding first- and second-line therapies. 33 % of protocols explicitly define status epilepticus according to contemporary guidelines, and 16.7 % have an operational definition of when to administer benzodiazepines. All protocols showed variations in dosing and administration instructions and only 28 % had a clearly stated first line treatment. ConclusionThere are disparities in the prehospital seizure management protocols within the Norwegian healthcare system, a system comparable to other European countries. To improve seizure management there is a need for standardised guidelines for prehospital treatment.

11 Is emergency department transfer always required following anaphylaxis and epinephrine use?

Abstract Background Patients known for anaphylaxis are advised to always carry 2 epinephrine auto-injectors (EAI) with them. With epinephrine being the first-line treatment for anaphylaxis, current guidelines recommend prompt EAI administration, followed by observation in the emergency department (ED) for 4 hours. Data supporting transfer to the ED in all cases after epinephrine are sparse. Recent North American allergy guidelines no longer suggest that ED presentation after EAI use is required for all cases of anaphylaxis. Objectives We aimed to describe the need for additional ED treatment in children known for food-triggered anaphylaxis who received at least 1 EAI pre-hospital. Design/Methods Data on children under 18 years with food-induced anaphylaxis who received at least one dose of pre-hospital epinephrine was collected from the Cross-Canada Anaphylaxis REgistry (C-CARE) from seven hospitals. A standardized questionnaire obtained information on symptoms, allergens, comorbidities, and pre-hospital and in-hospital management. Multivariable logistic regression was performed to identify factors associated with ED management, among children who received 1, 2 or 3 or more doses of epinephrine pre-hospital. Results From 2011 to 2023, 1054 children with known food-triggered anaphylaxis and who used one or more EAIs pre-hospital were enrolled in C-CARE. The mean age at reaction was 8.2 (standard deviation [SD] 5.3) years, 648 (60.8%) were male and 82 (7.8%) of reactions were severe (defined as loss of bowel control, cyanosis, respiratory arrest, hypotension and/or circulatory collapse, dysrhythmia, severe bradycardia and/or cardiac arrest, confusion, and loss of consciousness). Primary triggers included peanuts (n=280; 26.6%) followed by tree nuts (n=173; 16.4%). 193 patients (18.3%) had known asthma and 201 received additional dose(s) of epinephrine in the ED, the majority of whom (177, 88.1%) received one dose. Only 2.9% of patients required admission. Among all patients, reactions to egg were less likely to require additional epinephrine (aOR 0.90; 95% CI 0.83, 0.99), and more likely with severe reactions (aOR 1.24; 95% CI 1.14-1.35). Among patients who received only one EAI pre-hospital, severe reactions (adjusted odds ratio [aOR] 1.19; 95% confidence interval [CI] 1.08-1.31) and reactions to tree nuts (aOR 1.12; 95% CI 1.04-1.20) were associated with increased odds of an additional dose of epinephrine in hospital. Conclusion One-fifth of anaphylaxis cases that used EAI require an additional dose of epinephrine in ED. Children with severe reactions and reactions to tree nuts are more likely to require additional doses; these cases should be considered for ED transfer and treatment following pre-hospital EAI use.