Proton Shell Gaps in N=28 Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator

The first complete measurement of the β-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the β-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the β-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.

Maintenance of Certification-The Value to Patients and Physicians

This Viewpoint discusses the ABIM’s continuing efforts to innovate and streamline maintenance of certification, including the recently launched Longitudinal Knowledge Assessment (LKA), to better accommodate physicians’ schedules and desires for flexibility.

Recommended Resting-State fMRI Acquisition and Preprocessing Steps for Preoperative Mapping of Language and Motor and Visual Areas in Adult and Pediatric Patients with Brain Tumors and Epilepsy

Resting-state (rs) fMRI has been shown to be useful for preoperative mapping of functional areas in patients with brain tumors and epilepsy. However, its lack of standardization limits its widespread use and hinders multicenter collaboration. The American Society of Functional Neuroradiology, American Society of Pediatric Neuroradiology, and the American Society of Neuroradiology Functional and Diffusion MR Imaging Study Group recommend specific rs-fMRI acquisition approaches and preprocessing steps that will further support rs-fMRI for future clinical use. A task force with expertise in fMRI from multiple institutions provided recommendations on the rs-fMRI steps needed for mapping of language, motor, and visual areas in adult and pediatric patients with brain tumor and epilepsy. These were based on an extensive literature review and expert consensus.Following rs-fMRI acquisition parameters are recommended: minimum 6-minute acquisition time; scan with eyes open with fixation; obtain rs-fMRI before both task-based fMRI and contrast administration; temporal resolution of ≤2 seconds; scanner field strength of 3T or higher. The following rs-fMRI preprocessing steps and parameters are recommended: motion correction (seed-based correlation analysis [SBC], independent component analysis [ICA]); despiking (SBC); volume censoring (SBC, ICA); nuisance regression of CSF and white matter signals (SBC); head motion regression (SBC, ICA); bandpass filtering (SBC, ICA); and spatial smoothing with a kernel size that is twice the effective voxel size (SBC, ICA).The consensus recommendations put forth for rs-fMRI acquisition and preprocessing steps will aid in standardization of practice and guide rs-fMRI program development across institutions. Standardized rs-fMRI protocols and processing pipelines are essential for multicenter trials and to implement rs-fMRI as part of standard clinical practice.

Exploiting the potential of fabric phase sorptive extraction for forensic food safety: Analysis of food samples in cases of drug facilitated crimes

Drug-facilitated crimes (DFCs) entail the use of a single drug or a mixture of drugs to render a victim unable. Traditionally, biological samples have been gathered from victims and conducting analysis to establish evidence of drug administration. Nevertheless, the rapid metabolism of various drugs and delays in analysis can impede the identification of such substances. For this, the present article describes a rapid, sustainable, highly efficient and miniaturized protocol for the identification and quantification of three sedative-hypnotic drugs namely diazepam, chlordiazepoxide and ketamine in alcoholic beverages and complex food samples (cream of biscuit, flavoured milk, juice, cake, tea, sweets and chocolate). The methodology involves utilizing fabric phase sorptive extraction (FPSE) to extract diazepam (DZ), chlordiazepoxide (CDP), and ketamine (KET), Subsequently, the extracted sample are subjected to analysis using gas chromatography-mass spectrometry (GC-MS). Several parameters, including type of membrane, pH, agitation time and speed, ionic strength, sample volume, elution volume and time, and type of elution solvent, were screened and thoroughly optimized. Sol-gel Carbowax 20M (CW-20M) has demonstrated most effective extraction efficiency for the target analytes among all evaluated membranes. Under optimal conditions, the method displayed linearity within the range of 0.3-10 µg mL-1 (or µg g-1), exhibiting a coefficient of determination (R2) ranging from 0.996 to 0.999. The limits of detection (LODs) and limits of quantification (LOQs) for liquid samples ranging between 0.020 and 0.069 µg mL-1 and 0.066-0.22 µg mL-1, respectively. Correspondingly, the LODs for solid samples ranged from 0.056 to 0.090 µg g-1, while the LOQs ranged from 0.18 to 0.29 µg g-1. Notably, the method showcased better precision, with repeatability and reproducibility both below 5% and 10%, respectively. Furthermore, the FPSE-GC-MS method proved effective in determining diazepam (DZ) in forensic food samples connected to drug-facilitated crimes (DFCs). Additionally, the proposed method underwent evaluation for its whiteness using the RGB12 algorithm.

Fetal cardiovascular changes during open and fetoscopic in-utero spina bifida closure

OBJECTIVE

Laparotomy-assisted fetoscopic closure of spina bifida utilizing heated-humidified carbon dioxide gas has been associated with less maternal morbidity than open in-utero spina bifida closure. Fetal cardiovascular changes during these surgical interventions are not well defined. Our objective was to compare fetal bradycardia (defined as fetal heart rate (FHR)<110 bpm over 10 minutes) and changes in umbilical artery Doppler parameters throughout open in-utero closure with those observed during laparotomy-assisted fetoscopic closure.

METHODS

We conducted a prospective cohort study of 22 open and 46 fetoscopic consecutive in-utero closures between 2019 and 2023. Both cohorts had similar preoperative counseling and clinical management. FHR and umbilical artery velocimetry were systematically obtained during preoperative assessment, every 5 minutes during the intraoperative period, and in the postoperative assessment. FHR, pulsatility indexes and end-diastolic flows were segmented into hourly periods during surgery, and the lowest values were averaged for analysis. Umbilical vein maximum velocities were measured in the fetoscopic cohort. Each fetal heart rate recording time point was correlated to maternal parameters, including heart rate, systolic and diastolic blood pressures.

RESULTS

Fetal bradycardia occurred in 4/22 cases (18.2%) of open in-utero closure and in 21/46 cases (45.7%) of fetoscopic closure. FHR gradually decreased in both cohorts after general anesthesia and decreased further during surgery. FHR were significantly lower after two hours of surgery in the fetoscopic closure than in the open in-utero closure group. In addition, the FHR (BPM) change in the final stages of the fetal surgery from the baseline FHR was significantly lower in the fetoscopic cohort (-32.3 (-35.7, -29.1)) compared to the open cohort (-23.5 (-28.1, -18.8)) (p=0.002). Abnormal end-diastolic flow (defined as absent or reversed end-diastolic flow) in the umbilical artery Doppler velocity occurred in 3/22 (13.6%) of the open closure cohort and in 23/46 (50%) of the fetoscopic closure cohort (p=0.004). There were no differences in umbilical artery end-diastolic flow and pulsatility index between closure techniques during the various stages of assessment.

CONCLUSIONS

We observed a decrease in the FHR and abnormalities in umbilical artery Doppler parameters in both open in-utero and fetoscopic closure groups. Fetal bradycardia was more prominent during fetoscopic closure following heated-humidified carbon dioxide insufflation, but the FHR recovered after cessation of the heated-humidified carbon dioxide. Changes in FHR and umbilical artery Doppler parameters during in-utero spina bifida closure were observed to be transient, no cases required emergency delivery and no fetoscopic closure were converted to open closure. These observations should inform algorithms for perioperative management of fetal bradycardia associated with in-utero spina bifida closure. This article is protected by copyright. All rights reserved.

Early Bone Mineral Density Changes and Endocrinal Dysfunction in Childhood Brain Tumor Patients: A Prospective Study

PURPOSE/OBJECTIVE(S)

Reduced bone mineral density (BMD) and hormonal dysfunction are considered as a late effect of cranial radiation (RT). Only few studies have reported the occurrence of these problems soon after the diagnosis of brain tumor or RT initiation, emphasizing that these are not necessarily the late effects of RT. Thus, we conducted the study to analyze the incidence of low BMD and hormonal dysfunction prior to or within 6 months of RT (early change) in children with brain tumors.

MATERIALS/METHODS

The study was conducted as a part of intramural funding program at a tertiary care center in India. Childhood and adolescent brain tumor patients were advised for dual energy X-ray absorptiometry scan (DXA) and hormonal evaluation prior to RT. In some patients, first DXA was done within 6 months of RT due to logistics. To see the effect of radiation, we have planned to repeat hormonal evaluation after 6 and 12 months and DXA after 12 months of RT.

RESULTS

Twenty-five patients were analyzed. Median age at diagnosis was 11 years with a male to female ratio of 5.2:1. Medulloblastoma was the commonest diagnosis (n = 12), followed by glioma (n = 8), pineal tumors (n = 3) and ependymoma (n = 2). Nineteen and six patients underwent DXA before RT and within 6 months of RT respectively. For BMD assessment, Z score was calculated at hip and lumbar spine. BMD was defined as low (Z score = -1 to-1.99), very low (Z score = -2 to -2.5) and secondary osteoporosis (Z score ≤ -2.5). Median Z score at femur neck and spine was -2 and -1.9 respectively. Overall; 6, 3 and 9 patients had normal, low and very low BMD respectively. Seven patients had secondary osteoporosis (Table 1). Two patients with secondary osteoporosis had low vitamin D levels. None of the patient had compression fracture. On statistical analysis, no correlation was found between BMD changes and age, sex and site of the tumor. Pre RT endocrinal assessment (N = 25) was done by tanner staging and serum hormonal levels (GH, T3/T4/TSH, ACTH, cortisol and prolactin). Gonadal hormonal assessment was done in children with early or delayed puberty. Three patients were found to have endocrinal abnormality before RT (precautious puberty, central hypothyroidism and low sex hormones in 1 patient each). Follow up DXA and hormonal evaluation are awaited to see the effect of RT.

CONCLUSION

The index study is one of the very few studies evaluating the early changes in BMD and hormonal dysfunction soon after brain tumor diagnosis or within 6 months of RT. We observed that a significant proportion of children had reduced BMD and hormonal dysfunction before RT, highlighting the importance of early assessment and referral to the specialist for better quality of life. Table 1: BMD and endocrinal dysfunction before or within 6 months of RT.

An Automated Brain Metastasis Detection and Segmentation System from MRI with a Large Multi-Institutional Dataset

PURPOSE/OBJECTIVE(S)

Developments of automated systems for brain metastasis (BM) detection and segmentation from MRI for assisting early detection and stereotactic radiosurgery (SRS) have been reported but most based upon relatively small datasets from single institutes. This work aims to develop and evaluate a system using a large multi-institutional dataset, and to improve both identification of small/subtle BMs and segmentation accuracy of large BMs.

MATERIALS/METHODS

A 3D U-Net system was trained and evaluated to detect and segment intraparenchymal BMs with a size > 2mm using 1856 MRI volumes from 1791 patients treated with SRS from seven institutions (1539 volumes for training, 183 for validation, and 134 for testing). All patients had 3D post-Gd T1w MRI scans pre-SRS. Gross tumor volumes (GTVs) of BMs for SRS were curated by each institute first. Then, additional efforts were spent to create GTVs for the untreated and/or uncontoured BMs, including central reviews by two radiologists, to improve accuracy of ground truth. The training dataset was augmented with synthetic BMs of 3773 MRIs using a 3D generative pipeline. Our system consists of two U-Nets with one using small 3D patches dedicated for detecting small BMs and another using large 3D patches for segmenting large BMs, and a random-forest based fusion module for combining the two network outputs. The first U-Net was trained with 3D patches containing at least one BM < 0.1 cm3. For detection performance, we measured BM-level sensitivity and case-level false-positive (FP) rate. For segmentation performance, we measured BM-level Dice similarity coefficient (DSC) and 95-percentile Hausdorff distance (HD95). We also stratified performances based upon BM sizes.

RESULTS

For 739 BMs in the 134 testing cases, the overall lesion-level sensitivity was 0.870 with an average case-level FP of 1.34±1.92 (95% CI: 1.02-1.67). The sensitivity was >0.969 for the BMs >0.1 cm3, but dropped to 0.755 for the BMs < 0.1 cm3 (Table 1). The average DSC and HD95 for all detected BMs were 0.786 and 1.35mm. The worse performance for BMs > 20 cm3 was caused by a case with 83 cm3 GTV and artifacts in the MRI volume.

CONCLUSION

We achieved excellent detection sensitivity and segmentation accuracy for BMs > 0.1 cm3, and promising performance for small BMs (<0.1cm3) with a controlled FP rate using a large multi-institutional dataset. Clinical utility for assisting early detection and SRS planning will be investigated. Table 1: Per-lesion detection and segmentation performance stratified by individual BM size. N is the number of BMs in each category.

An Analysis of Patients Treated with Stereotactic Body Radiotherapy for Metastatic Urinary Tract Tumors to Identify Predictors of Response

PURPOSE/OBJECTIVE(S)

To identify selection criteria linked to outcomes in patients treated with stereotactic body radiotherapy (SBRT) for metastatic tumors of the urinary tract (UT).

MATERIALS/METHODS

Single institution retrospective analysis of SBRT treated patients for oligometastatic/progressive UT tumors from 2006-2022. Charts were queried for M1 status at diagnosis or during disease course, treatment details (surgery, SBRT, systemic therapy), metabolic status (diabetes [DM], BMI) and outcomes. A linear quadratic formula was used to calculate the biologically effective dose (BED) using an α/β of 10 for tumor. Descriptive statistics portrayed the cohort, and analyses were done at patient and site level. Time-to-event analyses, including overall survival (OS) and progression-free survival (PFS) from SBRT, were assessed by the Kaplan-Meier method. Cox regression was used for univariable (UVA) and multivariable analyses (MVA) to identify predictors of outcomes.

RESULTS

A total of 35 patients were treated at 44 metastatic sites, including: bone (25%), node (36.4%), lung (20.5%), soft tissue (13.6%) and liver (4.5%). Most were male (74.3%) with a median age of 70 (range: 51-89), without DM (60%) having a median BMI of 29.8, and ECOG <2 (97.1%) at time of SBRT. Six (17.1%) patients were M1 at diagnosis. Of the 29 non-M1 patients, 86.2% received definitive local therapy (LT), 58.6% had at least T3/N+ disease, 75.8% received systemic therapy with a median of 2 agents (range: 1-6) prior to SBRT. Sixteen (45.7%) received immunotherapy (IO) with most receiving this before (75%) and after (56.2%) SBRT. Six patients had positive PD-L1 status (n = 10). The median RT dose, fractionation and BED was 40 Gy (range: 14-46), 5 fractions, and 72 (range: 28-132), respectively. At a median follow-up of 34.8, the median OS was 18.4 m (range: 9.3-27.4) with a 2-year OS of 35.9%. At patient level, 62.8% recurred after SBRT. The median PFS after SBRT was 5.3 m (range: 1.8-8.7) with a 2-yr PFS of 29.3%. Patient-level PFS was improved with LT (6.7 vs 1.4 m; p = 0.001) and DM (NR vs 2.9 m; p = 0.015), whereas improved OS was related with LT (18.9 vs 6.6 m; p = 0.03), DM (p = 0.04), ECOG (p = 0.004), and no relapse after SBRT (NR vs 9.8 m; p <0.001). Exposure to < 3 systemic agents prior to SBRT portended better PFS (6.7 vs 2.6 m; p = 0.04) without any impact by IO. At site level, 20.4% of sites had local relapse with 4 being the first event. Site was related with PFS (p = 0.009) with order of increased relapse risk being liver > bone > soft tissue > node > lung. No dosimetric feature was related with recurrence risk. On MVA, both DM (p = 0.02) and LT (p = 0.002) were predictive for PFS. Only recurrence after SBRT predicted for OS on MVA (HR: 6.7, 95% CI: 1.4-31; p = 0.014). In the IO subset, median PFS was 5.3 m and OS was 9.4 m, with no difference seen with IO-SBRT sequence or PDL1 status.

CONCLUSION

Optimized selection criteria for metastasis-directed therapy in patients with UT tumors is unclear, notably with IO. Future studies may benefit by assessing circulating tumor markers prior to SBRT.

Multidisciplinary Management of Primary Urethral Cancer with Radiotherapy

PURPOSE/OBJECTIVE(S)

Primary urethral cancer (PUC) is a rare form of genitourinary malignancy with a paucity of data to guide management. We analyzed PUC patients for clinicopathologic characteristics and treatment approach (radiotherapy [RT] with/without consolidative surgery) to identify predictors of outcome and RT response.

MATERIALS/METHODS

We conducted a single-institution retrospective review of patients treated with RT for PUC between 2002 to 2020. Each patient underwent multidisciplinary evaluation (including cystoscopy) as well as imaging to confirm tumor origin in the urethra. The linear quadratic formula was used to calculate the biologically effective dose (BED) using an α/β of 10 for tumor. Descriptive statistics were used to characterize the cohort. Fisher's Exact test was used to compare groups. Time-to-event analyses was conducted with the Kaplan-Meier method; outcomes included overall survival (OS) and time to recurrence (TTR) from diagnosis. Cox regression analysis assessed predictors of outcomes.

RESULTS

A total of 17 patients were identified for analysis. Median age was 63 years (range: 34-86); the majority were female (76.5%) and white (82.4%). Tumors were localized in the proximal (n = 6) or distal (n = 11) urethra. Histology included urothelial (11.8%), squamous (35.3%), adenocarcinoma (29.4%) and mixed (23.5%). Ten patients (58.8%) had cT3 or higher disease with 10 being cN0 (58.8%), 1 cN1 (5.9%), 5 cN2 (29.4%) and 1 cNx (5.9%). Median tumor size was 4.8 cm (range: 0.5-12 cm). The majority (88.2%) were treated with definitive chemoRT with 70.5% receiving platinum therapy. Median RT dose was 59.4 Gy (range: 39.6-70.2) with a median of 30 fractions. One patient underwent upfront cystourethrectomy and 6 (35.3%) underwent consolidative surgery at a median of 2.3 months after RT. Five patients (29.4%) had a complete response (CR) and 70.6% had a partial response (PR) to RT. Of the 7 patients who underwent surgical resection the final pathology was ypTis (28.5%), ypT1 (14.2%), ypT2 (14.2%), ypT4 (28.5%) and pT2 (14.2%). A median of 16 lymph nodes were removed with 1 patient having pN2 and all others pN0. Four patients (66.6%) were downstaged by chemoRT prior to surgery. At a median follow-up time of 8.4 years, the median OS was 37.9 months (range: 23.2-52.7), which was associated with a 5-year OS of 37.2%. Twelve (70.5%) patients recurred with a median TTR of 6.3 months (range 4.8-7.7). No demographics, staging methods, or tumor characteristics were associated with OS or TTR. Urothelial histology was associated with CR following chemoRT (p = 0.02). RT dose (continuous) was associated with OS (p = 0.018) as well as a BED (HR: 0.90, 95% CI: 0.84-0.97; p = 0.01). A BED > 55 Gy was associated with improved median OS (56.4 vs 9.13 months, p = 0.006).

CONCLUSION

Analysis of PUC patients treated with multimodal therapy found higher rates of CR in patients with urothelial histology and increased OS in patients treated with a BED > 55 Gy. Neoadjuvant chemoRT may downstage disease prior to surgical extirpation.

Long-Term Follow-up of Multinodular and Vacuolating Neuronal Tumors and Implications for Surveillance Imaging

BACKGROUND AND PURPOSE

Most multinodular and vacuolating neuronal tumors (MVNTs) are diagnosed and followed radiologically without any change across time. There are no surveillance guidelines or quantitative volumetric assessments of these tumors. We evaluated MVNT volumes during long follow-up periods using segmentation tools with the aim of quantitative assessment.

MATERIALS AND METHODS

All patients with MVNTs in a brain MR imaging report in our system were reviewed. Patients with only 1 brain MR imaging or in whom MVNT was not clearly the most likely diagnosis were excluded. All MVNTs were manually segmented. For all follow-up examinations, absolute and percentage volume change from immediately prior and initial examinations were calculated.

RESULTS

Forty-eight patients (32 women; median age, 50.5 years at first scanning) underwent 158 brain MRIs. The median duration between the first and last scan was 15.6 months (interquartile range, 5.7-29.6 months; maximum, 6.4 years) and between consecutive scans, it was 6.7 months (interquartile range, 3.3-12.4 months; maximum, 4.9 years). Pearson correlation coefficients between days since immediately prior scan versus absolute and percentage volume change from immediately prior scan were r = 0.05 (P = .60) and r = 0.07 (P = .45), respectively. For the relationship between days since the first scan versus absolute and percentage volume change from the first scan, values were r = -0.06 (P = .53) and r = -0.04 (P = .67), respectively.

CONCLUSIONS

MVNT segmentation across follow-up brain MR imaging examinations did not demonstrate significant volume differences, suggesting that these tumors do not enlarge with time. Hence, frequent surveillance imaging of newly diagnosed MVNTs may not be necessary.

CLINICAL AND OBJECTIVE TEST CHARACTERISTICS OF VESTIBULAR MIGRAINE: IMPLICATIONS FOR DIAGNOSIS AND MANAGEMENT

The research we provided look at a number of factors, such as age, unilateral testing, and squinting both during the ictal and interictal periods to define vestibular migraine. One hundred and ten adults with recurrent spontaneous and positional vertigo participated in the study, which the investigators did. Vestibular migraines (VM) or probable vestibular migraine constituted the two diagnoses given to the patients (n = 29 and n = 76, respectively). The findings revealed those surveyed frequently complained of headache (85.3%), spinning vertigo (76.2%), and Mal de Débarquement (60.2%), with movement hypersensitivity (32.6%). After an episode, 75.2% of individuals having vestibular migraine showed spontaneous squinting, whereas 16.5% did so among assaults, although fixing was forbidden. 27.3% of people had clear spatial squinting after an assault, while 57.3% did so after assaults. In 51.2% of instances, the direction of ictal spontaneous Nystagmus was straight, while in 19.5% of cases, it was vertical. Positional and spontaneously ictal squinting was evaluated at speeds between 0.0 and 59.3 degrees per second and 0.0 and 99.9 levels per minute, respectively. In 92.6% and 25.1% of instances, respectively, the interact spontaneous and positional nystagmus velocities were typically less than 3 degrees/second. When contrasted with the time within assaults, squinting speeds were substantially greater after an assault. According to additional tests, 98.6% of those tested exhibited normal lateral video head impulse test gains, indicating that their vestibule-ocular responses were in place. The calorie test findings were symmetrical in 86.4% of the instances, showing normal vestibular function. In 90.4% and 95.2% of cases misogynic potentials displayed symmetrical magnitudes. In 69.8% and 98.1% of instances, misogynic possibilities were identical. In 89.3% of cases, the audiometer data is generally uniform and age-consistent. In outcome, low-velocity squinting that can be horizontal, vertical, or torsional motions occur throughout a sensory migraines event. The investigation also discovered that patients with vestibular migraine often had acceptable audio vestibular test findings.

Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB

Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-μs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1  μs≤T_{1/2}<1  ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.

Trends in clinical validation and usage of US Food and Drug Administration-cleared artificial intelligence algorithms for medical imaging

AIM

To examine the current landscape of US Food and Drug Administration (FDA)-approved artificial intelligence (AI) medical imaging devices and identify trends in clinical validation strategy.

MATERIALS AND METHODS

A retrospective study was conducted that analysed data extracted from the American College of Radiology (ACR) Data Science Institute AI Central database as of November 2021 to identify trends in FDA clearance of AI products related to medical imaging. Product and clinical validation information of each device was gathered from their respective public 510(k) summary or de novo request submission, depending on their type of authorisation.

RESULTS

Overall, the database included a total of 151 AI algorithms that were cleared by the FDA between 2008 and November 2021. Out of the 151 FDA summaries reviewed, 97 (64.2%) reported the use of clinical data to validate their device, with six (4%) revealing study participant demographics, and eight (5.3%) reporting the specifications of the machines used. A total of 51 (33.8%) AI devices characterised their clinical data as multicentre, three (2%) as single-centre, and the remaining 97 (64.2%) did not specify. The ground truth used for clinical validation was specified in 78 (51.6%) FDA summaries.

CONCLUSION

A wide breadth of AI algorithms has been developed for medical imaging. Most of the FDA summaries of the devices mention their use of clinical data and patient cases for device validation; however, few devices revealed the patient demographics or machine specifications used in their clinical studies, which may lead some consumers to question their external validation.

Simple determination of dichlorvos in cases of fatal intoxication by gas Chromatography-Mass spectrometry

Dichlorvos (DDVP) is an organophosphorous insecticide which is classified as "highly hazardous" Class 1B chemical by World Health Organization (WHO) and largely misused for the purpose of self-poisoning in developing countries. Forensic toxicology laboratories are routinely encountering cases of pesticide poisoning due to their fatal intoxication. Herein; a method is described based on vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) for the determination of an organophosphorous insecticide; dichlorvos (DDVP) in human autopsy samples (blood, stomach content and liver). Under the optimum conditions, the method was found to be linear in the range of 0.5-10 µg mL^-1 and 1.5-10 µg g^-1 for blood and tissue samples, respectively. Limit of quantification was set at 0.55 µg mL^-1 and 1.1 µg g^-1 for blood and tissue samples, respectively. Intraday and inter-day precisions were less than 8 and 12 %, respectively. Good recoveries in the range of 86-95 % were obtained for the proposed procedure. The method has been satisfactorily applied for the determination of DDVP in autopsy samples from two different cases received in our laboratory. In comparison to previous methods; the proposed method is relatively short, high sample throughput, inexpensive and adheres to the principles of green analytical chemistry (GAC) for determination of DDVP in human autopsy samples. The method can be adopted in forensic toxicological laboratories for analysis of DDVP in autopsy samples. In addition, the green character of the proposed method was evaluated using ComplexGAPI procedure.

Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB

New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.

Patients not taking a previously prescribed bone active medication now prescribed medication through Ontario FLS

In an Ontario fracture liaison service (FLS), we compared medication prescription rates among patients not taking a previously prescribed bone active medication to those with no previous prescription. Prescription rates were similar between these two groups of patients. The FLS provided a secondary opportunity for patients to initiate bone active medication.

PURPOSE

We compared bone active medication prescription rates among patients presenting to an Ontario fracture liaison service (FLS) who reported not taking a previously prescribed bone active medication to those with no history of prescription.

METHODS

Eligible patients were those screened in 39 fracture clinics between July 1, 2017, and September 15, 2019, who were not taking bone active medication at the time of screening and classified as high risk for future fracture based on CAROC or FRAX. Sociodemographic and clinical risk factor variables were assessed at screening. Bone active medication prescription rate was assessed within 6 months of screening and defined as having received a prescription for the medication from either a specialist or primary care provider. In cases where a specialist report was not available, patient self-reported data were collected. The chi-square test of independence was used to assess differences in prescription rates.

RESULTS

Of 17,575 patients screened, eligible patients were 350 with a previous prescription and 2644 without a previous prescription. Compared with patients who reported no previous prescription, those who had a previous prescription were older, more likely to be female and to report a previous fracture, and less likely to smoke. There was no statistically significant difference between the medication prescription rate of patients with a previous prescription (73.7%) compared to patients with no previous prescription (70.7%) (p = 0.157).

CONCLUSION

A large jurisdiction-wide FLS approach provided a secondary opportunity to patients who were not taking a previously prescribed bone active medication to initiate that medication.

Rapid Determination of Non-Steroidal Anti-Inflammatory Drugs in Urine Samples after In-Matrix Derivatization and Fabric Phase Sorptive Extraction-Gas Chromatography-Mass Spectrometry Analysis

Fabric phase sorptive extraction (FPSE) has become a popular sorptive-based microextraction technique for the rapid analysis of a wide variety of analytes in complex matrices. The present study describes a simple and green analytical protocol based on in-matrix methyl chloroformate (MCF) derivatization of non-steroidal anti-inflammatory (NSAID) drugs in urine samples followed by FPSE and gas chromatography-mass spectrometry (GC-MS) analysis. Use of MCF as derivatizing reagent saves substantial amounts of time, reagent and energy, and can be directly performed in aqueous samples without any sample pre-treatment. The derivatized analytes were extracted using sol−gel Carbowax 20M coated FPSE membrane and eluted in 0.5 mL of MeOH for GC-MS analysis. A chemometric design of experiment-based approach was utilized comprising a Placket−Burman design (PBD) and central composite design (CCD) for screening and optimization of significant variables of derivatization and FPSE protocol, respectively. Under optimized conditions, the proposed FPSE-GC-MS method exhibited good linearity in the range of 0.1−10 µg mL−1 with coefficients of determination (R2) in the range of 0.998−0.999. The intra-day and inter-day precisions for the proposed method were lower than <7% and <10%, respectively. The developed method has been successfully applied to the determination of NSAIDs in urine samples of patients under their medication. Finally, the green character of the proposed method was evaluated using ComplexGAPI tool. The proposed method will pave the way for simper analysis of polar drugs by FPSE-GC-MS.

Spatial Relationship of Maxillary Posterior Teeth with Maxillary Sinus Floor in Sagittal, Coronal and Axial Planes by Using Cone-Beam Computed Tomography in a Subpopulation of Central India

Inadvertent perforation of the root apex during endodontic procedure in maxillary posterior teeth may unnecessarily invite the complications of sinusitis or inflammatory responses. This becomes even more important when performing endodontic surgical procedures. Thus, it is mandatory to have the precise knowledge of anatomic structures which are in close proximity to the apex of roots and its variations among different geographic area. This retrospective observational study was performed in the Central India to assess the spatial relationships between the maxillary second pre-molar (sPM), maxillary first molar (M1), maxillary second molar (M2) with the maxillary sinus floor using cone beam computed tomography (CBCT) in all three axial, sagittal and coronal sections from year 2016 to 2021. Three hundred and sixty teeth were examined through sixty full volumes CBCT scans of the patients in between year 2016-2021 in Indore, (MP, India). The Distances (D) between the examined roots and the sinus floor, were evaluated using CBCT in all three sections, and grouped in 7 classes. To simplify, Class 1 and 2 were grouped as Negative Configuration where apices are protruding into sinus floor, Class 3 as Zero and Class 4-7 as Positive configuration. The data were analyzed statistically using SPSS system. The prevalence of class 1 and 2 (negative configuration) was the highest for the Palatal of M1 (16.67%) followed by Distobuccal of M1 (13.34%). The prevalence of class 3 that is Zero configuration was the highest for the Mesiobuccal of M2 (63.33%). The results suggested all the three teeth roots showed closed proximity with sinus floor, closest relationship with the sinus floor was seen in palatal of M1 in this study.

Confronting implicit bias toward patients: a scoping review of post-graduate physician curricula

BACKGROUND

Physicians' behavior may unknowingly be impacted by prejudice and thereby contribute to healthcare inequities. Despite increasingly robust data demonstrating physician implicit bias (The Office of Minority Health. Minority Population Profiles, 2021; COVID-19 Shines Light on Health Disparities, National Conference of State Legislatures 2021), the evidence behind how to change this with training programs remains unclear. This scoping review therefore reports on the implementation, outcomes, and characteristics of post-graduate physician implicit bias curricula.

METHODS

The authors conducted a literature review using scoping review methodology. They searched 7 databases in February and November 2020 for English-language academic and gray literature on implicit bias curricula for physicians at all levels of post-graduate training. Ten reviewers screened studies for eligibility independently, then extracted data from these studies and compiled it into a chart and analytical summary.

RESULTS

Of the 4,599 articles screened, this review identified 90 articles on implicit bias interventions for post-graduate physicians. Inductive data analysis revealed a spectrum of educational approaches, which were categorized int o 4 educational models called Competence, Skills-Based, Social Contact, and Critical Models. The most commonly reported strength was the interactive nature of the curricula (26%), and the most frequently identified challenges were related to time and resources available (53%). Half of the interventions discussed facilitator preparation, and the majority (62%) evaluated outcomes using pre and post self-assessments.

CONCLUSIONS

This review provides a comprehensive synthesis of the literature on physician implicit bias curricula. It is our goal that this supports medical educators in applying and improving aspects of these interventions in their own programs.

Fragility fracture patients with a history of prior fractures more likely to present with multiple risk factors: findings from a province-wide fracture liaison service

We examined the demographic characteristics and risk factors of FLS fragility fracture patients who had sustained prior fragility fracture(s) and found that this is an important high-risk subgroup that warrants further attention within FLS priority pathways in order to disrupt their fragility fracture cycle.

PURPOSE

Our primary objective was to examine whether fragility fracture patients presenting to a provincial fracture liaison service (FLS) having a history of prior fractures, versus those without, differ in demographic characteristics and risk factors for future fracture. A secondary objective was to understand if those who report two or more prior fractures differ from those reporting one prior fracture.

METHODS

This cohort study included fragility fracture patients aged 50 + enrolled in the Ontario FLS between July 2017 and September 2019. Patients with versus those without prior fractures were compared on age, sex, index fracture site, biological parents' history of hip fracture, current fracture due to a fall, history of feeling unsteady when walking, history of falls in the past year, smoking, oral steroid use, and comorbid chronic conditions. Pearson's chi-square, Fischer's exact, and analysis of variance tests were used to assess differences.

RESULTS

Among 14,454 patients, 16.8% (n = 2428) reported a history of one or more prior fractures after the age of 40. They were significantly more likely to be older, female, with a higher number of comorbidities, with greater incidence of falls, and feel unsteady when walking. Compared to those with one prior fracture, patients with greater than one prior fracture were more likely to report falls in the past year and feel unsteady when walking.

CONCLUSION

Findings suggest that FLS fragility fracture patients who had sustained prior fragility fracture are an important high-risk subgroup that warrants further attention within FLS priority pathways in order to disrupt their fragility fracture cycle.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Evidence of a Near-Threshold Resonance in ^{11}B Relevant to the β-Delayed Proton Emission of ^{11}Be

A narrow near-threshold proton-emitting resonance (E_{x}=11.4  MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4  keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the β-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11  keV) emission channels.

A cross sectional survey on physical fitness, mental health and associated factors in mothers of children with special needs

Mothers are the primary caregivers of a child. While caring for a special needs child, workload of caring increases by manifold and taking care of these children increases physical & mental overload. There is a dearth of studies that have objectively evaluated mental health and fitness of this group. To study status of physical fitness, mental health and associated factors in mothers of special needs children a cross-sectional survey done on 100 mothers of special needs children from special schools in the Gurugram District, Haryana, India. The Harvard Step test was used to evaluate cardiac fitness. Standard tests were used to evaluate different components of musculoskeletal fitness. Depression was assessed by Beck Depression Inventory. Descriptive statistics were used for data analysis. The Karl Pearson correlation test was used to identify correlations between mental health and fitness components and sociodemographic characteristics. Mean age and body mass index of mothers was 36.15±2.56 years and 27.4±3.25 kg/m2, respectively. 50% of the subjects were overweight, 89% scored poor in cardiopulmonary fitness, 63% had very poor muscle endurance, and 69% had average muscular flexibility. 81% of the mothers had symptoms of clinical depression. Inverse and significant correlation was present between depression and cardiorespiratory fitness (r=-0.197), strength (r=-0.242), and endurance (r=0.209). Income, total number of children and duration of care giving were inversely correlated with depression. Positive correlation was found between type of disability and depression. There was an overall decrement in cardiorespiratory and musculoskeletal fitness. Mental health was found to be poor with a large percentage of participants showing symptoms of depression.

Safety assessment of Streptococcus salivarius M18 a probiotic for oral health

The development of probiotics targeting non-intestinal body sites continues to generate interest amongst researchers, biotech companies and consumers alike. A key consideration for any bacterial strain to be developed into a probiotic is a robust assessment of its safety profile. Streptococcus salivarius strain M18 was originally isolated from a healthy adult and evaluated for its probiotic capabilities targeted to dental and oral health applications. This publication presents the safety characterisation of strain M18. Application of a diverse range of techniques showed that strain M18 can be specifically distinguished from other S. salivarius using a variety of molecular and phenotypic methodologies and that it lacks any relevant antibiotic resistance or virulence determinants. Direct comparison of the strain M18 safety profile with that of the prototype S. salivarius probiotic, S. salivarius strain K12, supports the proposition that strain M18 is indeed safe for probiotic application in humans.

Quantifying T2-FLAIR Mismatch Using Geographically Weighted Regression and Predicting Molecular Status in Lower-Grade Gliomas

BACKGROUND AND PURPOSE

The T2-FLAIR mismatch sign is a validated imaging sign of isocitrate dehydrogenase-mutant 1p/19q noncodeleted gliomas. It is identified by radiologists through visual inspection of preoperative MR imaging scans and has been shown to identify isocitrate dehydrogenase-mutant 1p/19q noncodeleted gliomas with a high positive predictive value. We have developed an approach to quantify the T2-FLAIR mismatch signature and use it to predict the molecular status of lower-grade gliomas.

MATERIALS AND METHODS

We used multiparametric MR imaging scans and segmentation labels of 108 preoperative lower-grade glioma tumors from The Cancer Imaging Archive. Clinical information and T2-FLAIR mismatch sign labels were obtained from supplementary material of relevant publications. We adopted an objective analytic approach to estimate this sign through a geographically weighted regression and used the residuals for each case to construct a probability density function (serving as a residual signature). These functions were then analyzed using an appropriate statistical framework.

RESULTS

We observed statistically significant (P value = .05) differences between the averages of residual signatures for an isocitrate dehydrogenase-mutant 1p/19q noncodeleted class of tumors versus other categories. Our classifier predicts these cases with area under the curve of 0.98 and high specificity and sensitivity. It also predicts the T2-FLAIR mismatch sign within these cases with an under the curve of 0.93.

CONCLUSIONS

On the basis of this retrospective study, we show that geographically weighted regression-based residual signatures are highly informative of the T2-FLAIR mismatch sign and can identify isocitrate dehydrogenase-mutation and 1p/19q codeletion status with high predictive power. The utility of the proposed quantification of the T2-FLAIR mismatch sign can be potentially validated through a prospective multi-institutional study.

Frequency of metastasis to the gastrointestinal tract determined by endoscopy in a community-based gastroenterology practice

Metastasis to the gastrointestinal tract is rare. We performed a retrospective analysis to identify patients with metastatic disease to the gastrointestinal tract using two databases containing pathology results from all endoscopic procedures conducted by nearly 200 gastroenterologists in a community setting over a 14-year period. Forty-nine patients were diagnosed with metastasis to the gastrointestinal tract by endoscopy during the study period. Most were women (71%). The most common metastases to the gastrointestinal tract identified by endoscopy were breast cancers (n = 18), followed by melanomas (n = 12), ovarian cancers (n = 7), kidney cancers (n = 5), prostate cancers (n = 2), lung cancer (n = 1), and pancreatic cancer (n = 1). Three patients had unknown primary sites. Among women, the three leading known primary tumor sites were breast, ovary, and melanoma. Among men, the three leading primary tumor sites were melanoma, kidney, and prostate. The stomach was the most common portion of the gastrointestinal tract involved by metastases. Most affected women and were most frequently encountered in the stomach.

Serious health threats of novel adulterants of the street heroin: a report from India during the COVID-19 pandemic

The COVID-19 pandemic and a consequent nationwide lockdown in India for several weeks had restricted the access to street heroin and treatment for substance abuse. Use of cutting agents to increase the volume or psychoactive effect has been widely practised under such circumstances. Our patient with opioid use disorder chased heroin with an unknown cutting agent to enhance psychoactive effect from the limited quantities of heroin. He suffered from an abrupt onset sedation, weakness, postural imbalance, slurred speech, cognitive dysfunctions and disinhibited behaviour. Symptoms rapidly reversed following abstinence and initiation of buprenorphine–naloxone. Gas chromatography-mass spectrometric analysis of the adulterant revealed high concentrations of benzodiazepines and barbiturates, alongside the usual cutting agents—caffeine and acetaminophen. Abrupt reduction in availability of ‘street drugs’ in conjunction with poor healthcare access can lead to the use of novel adulterants with potentially serious clinical and public health implications.

P–280 Changes in oolemma height during ICSI injection on day 0 is associated with day 5–6 blastocyst formation

Study question

Does the oolemma response to ICSI injection on day 0 affect blastocyst formation on day 5–6 (d5/6)?

Summary answer

A large change in oolemma height during ICSI injection on day 0 is associated with lower blastocyst formation rates on d5/6.

What is known already

The oolemma changes in all dimensions (i.e. height, width and depth) and can exhibit different reactions in ICSI during needle injection. This is seen as instant rupture or with little needle pressure, normal rupture with the needle pushed approximately halfway through, or difficult rupture with repeated attempts or the needle passing 3/4 of the oocyte width. Previous studies have shown that these responses can affect degeneration and fertilisation rates on day 1, however, there is little research on its effect on blastocyst formation rates. Furthermore, most previous studies have used qualitative methods to assess oolemma response.

Study design, size, duration

This is a retrospective study using ICSI procedure videos conducted by four embryologists in a private clinic from 2013–2015. All videos of procedures which did not result in 2PN or in which the oocyte was not fully visible were excluded. Six operators categorised 455 videos (by majority vote) into four groups based on the oolemma response: oolemma breakage within 1/4, between 1/4 and 1/2, between 1/2 and 3/4 and beyond 3/4 of the oocyte’s width.

Participants/materials, setting, methods

A U-Net neural network model was trained to extract the frame of maximum oolemma indent from each video which were validated by a human operator; any in which maximum indent occured after breaking of the oolemma were excluded. The ratio of starting to maximal indent width/height were calculated automatically and human-validated. Chi-squared tests were performed for each ratio vs d5/6 blastocyst formation. These results were compared with those obtained from purely human annotations.

Main results and the role of chance

From the purely human annotations, the percentages of oocytes in groups 1–4 respectively were: 3.3%, 85.3%, 11.4% and 0%. This variation in oolemma response may be due to the arrangement of thick and thin microfilaments or cortical granules in the cytoskeleton. When analysed with d5/6 blastocyst formation, these showed no significant result (p = 0.12) which is consistent with findings using the model.

The artificial intelligence (AI) model processed 26 frames per second. During human validation of the ratios calculated at maximal indentation, 36% of width ratios and 31% of height ratios were rejected.

The proportion of blastocysts formed in the upper and lower quartile for each ratio was analysed. Both the upper (0.49) and lower (0.41) quartiles of the width ratios were not significant for d5/6 blastocyst formation. The lower (1.12) quartile of height ratios showed no significance, however there were significantly fewer blastocysts formed on d5/6 for the upper (1.18) quartile of height ratios (p &lt; 0.025). This subtle change in the height ratio, which was significant for d5/6 blastocyst formation was not taken into account when grouping oocytes any previous literature (and our human labelling).

Limitations, reasons for caution

This study was conducted at a single clinic so variations between clinics were not captured in the study and would need further collaborations to confirm the proportion of oocytes responses. Due to the small sample size, this study also did not identify any group 4 oocytes cultured until d5/6.

Wider implications of the findings: The grouping criteria in this study were more quantitative than previous work yet indicated no correlation between the oolemma group and d5/6 blastocyst formation. However, changes in the height which are hard to assess in real-time (and which have been neglected in previous literature) were seen to be significant.

Trial registration number

NA

Seroprevalence of SARS-CoV-2 among potential convalescent plasma donors and analysis of their deferral pattern: Experience from tertiary care hospital in western India

Background and objectives

Seroprevalence estimation of COVID-19 is quite necessary for controlling the transmission of SARS-CoV-2 infection. Seroprevalence rate in recovered COVID-19 patients help us to identify individual with anti-SARS-CoV-2 antibodies and its protective nature. The objective of present study was to evaluate seroprevalence of SARS-CoV-2 among potential convalescent plasma donors and analysis of their deferral reasons.

Materials and methods

A total 400 potential convalescent plasma donors were enrolled over five-month period for this prospective study. Inclusion criteria were lab confirmed COVID-19 recovered patients and 14 days of symptoms free period. All prospective plasmapheresis donors were tested for IgG SARS-CoV-2 antibody through chemiluminescent microparticle immunoassay, CBC, serum protein, blood grouping along with other required test for normal blood donation as per Drugs & Cosmetics Act. After pre donation testing and medical examination if donor was found to be ineligible for plasmapheresis was deferred. Seroprevalence rate was calculated by positive IgG antibody test results among the potential plasma donors.

Results

Seroprevalence rate was 87% for IgG SARS-CoV-2 antibodies in prospective convalescent plasma donors (recovered COVID-19 patients). There was no significant difference in seroprevalence rate between different sub-groups with respect to gender, age, blood groups, Rh factor, mode of treatment, day of Ab testing and repeat plasma donation. Most common reason for their deferral was absent IgG SARS-CoV-2 antibodies (13%) followed by absenteeism of eligible screen donors (6.7%), low Hb (1.7%) and poor veins for plasmapheresis (1.7%). Till five-month study period none of the plasmapheresis develop symptoms of reinfection with COVID-19.

Conclusion

In all, 13% recovered patients did not develop IgG antibodies after SARS-CoV-2 infection. SARS-CoV-2 IgG antibodies persist for quite some time and are protective against reinfection. More long-term serology studies are needed to understand better antibody response kinetics and duration of persistence of IgG antibodies.

Patients 80 + have similar medication initiation rates to those aged 50-79 in Ontario FLS

Among individuals presenting to an Ontario FLS, we compared bone active medication initiation rates of patients 80 years and older with those 50-79 years old. After accounting for fracture risk status, there was no statistically significant difference in medication initiation rates between the two age groups INTRODUCTION: A Fracture Liaison Service (FLS) offers post-fracture services to individuals over the age of 50 years and could potentially address age inequities in pharmacotherapy often observed for older adults. Among individuals presenting to an Ontario FLS and classified as being at high risk for future fracture, our objective was to compare bone active medication initiation rates of patients 80 years and older with those 50-79 years old.

METHODS

In 39 FLS fracture clinics across Ontario, Canada, fracture prevention coordinators identified, assessed, and facilitated the referral of eligible patients for bone densitometry, fracture risk assessment, and implementation of pharmacotherapy in patients classified as high risk for future fracture. Variables assessed at baseline included age, sex, marital status, living location, fracture location, history of previous fracture, parent's history of hip fracture, history of falls, and fracture risk status. At 6 months, bone active medication initiation was assessed in patients classified as high risk for future fracture. The Chi-square test of independence was used to compare medication initiation rates between patients 80 + and those 50-79 years old.

RESULTS

Our sample size consisted of 808 patients aged 50-79 years and 346 aged 80 + years. After accounting for fracture risk status, there was no statistically significant difference in medication initiation rates of patients 50-79 and 80 + years old (76.9% versus 73.7%, p = 0.251).

CONCLUSION

A systematic approach to identifying patients at high risk for future fracture and tailoring treatment recommendations to these patients appeared to eliminate differences in treatment initiation rates based on older age.

Intriguing role of novel ionic liquids in stochastic degradation of chitosan

Green technique for hydrolysis of chitosan was developed using novel Brønsted Acidic Ionic Liquids (BAILs) as homogenous reusable catalysts. Efficiency of BAILs in controlling stochastic and irregular breakdown of chitosan was compared with that of mineral acids. Structural elucidation of the novel BAILs was performed using H¹-NMR evaluation and supplemented using mass spectroscopy. Additionally, thermal characterization was conducted using TGA-DTA analysis, while acidity was estimated by deriving the Hammet acidity function. BAILs investigated in this work enabled consistent production of LMWCS variants, with minimum formation of residual impurities. Around 80 % reduction in molecular weight was noted as compared to original under extreme conditions employed. Further, Box-Behnken Design (BBD) was implemented to optimize effect of processing parameters for conversion of chitosan to low molecular weight congeners.