The Role of Preoperative Antibiotics in Surgical Site Infection (SSI) Rate after Class I/Clean Gynaecologic Surgery at an Academic Safety Net Hospital.

OBJECTIVES: Examine whether preoperative antibiotics in class I/clean abdominal gynaecologic surgery decrease the incidence of surgical site infections (SSI). METHODS: Retrospective cohort study at academic safety net hospital of patients undergoing class I laparoscopic or open gynaecologic surgery between November 2013 and September 2017. Performance improvement initiative to administer preoperative antibiotics to all surgical patients starting July 2016. RESULTS: In total, 510 patients were included: 283 in the antibiotic group and 227 in the no-antibiotic group. PRIMARY OUTCOME: incidence of SSI. Baseline characteristics were similar between groups once balanced by propensity score method. In unweighted analysis, incidence of SSI decreased from 9.3% (21/227) in the no-antibiotics group to 4.9% (14/283) in antibiotics group, but this was not statistically significant (odds ratio (OR) 0.51 CI 0.25-1.03, P = 0.0598). Following of inverse probability of treatment weighting adjustments in weighted analysis, incidence of SSI was found to be significantly lower in patients who received antibiotics compared to patients who did not receive antibiotics across entry types (4.6% vs. 9.8%, OR 0.45; CI 0.22-0.90, P = 0.023). Weighted analysis demonstrated in the exploratory laparotomy group patients who received antibiotics had a lower incidence of SSI compared to patients who did not receive antibiotics (5.1% vs. 18.7%, OR 0.23; CI 0.08-0.68, P = 0.008). In the laparoscopy group, there was no difference between groups (4.4% vs. 5.4%, OR 0.81; CI 0.3-2.16, P = 0.675). CONCLUSIONS: There is limited literature on SSI prevention/preoperative antibiotic use in class I gynaecologic surgeries. This study demonstrates antibiotics in class I procedures decrease SSI rates, specifically in open procedures. There was a lack of demonstrated benefit in laparoscopy.

MRI Radiogenomics of Pediatric Medulloblastoma: A Multicenter Study.

Background Radiogenomics of pediatric medulloblastoma (MB) offers an opportunity for MB risk stratification, which may aid therapeutic decision making, family counseling, and selection of patient groups suitable for targeted genetic analysis. Purpose To develop machine learning strategies that identify the four clinically significant MB molecular subgroups. Materials and Methods In this retrospective study, consecutive pediatric patients with newly diagnosed MB at MRI at 12 international pediatric sites between July 1997 and May 2020 were identified. There were 1800 features extracted from T2- and contrast-enhanced T1-weighted preoperative MRI scans. A two-stage sequential classifier was designed-one that first identifies non-wingless (WNT) and non-sonic hedgehog (SHH) MB and then differentiates therapeutically relevant WNT from SHH. Further, a classifier that distinguishes high-risk group 3 from group 4 MB was developed. An independent, binary subgroup analysis was conducted to uncover radiomics features unique to infantile versus childhood SHH subgroups. The best-performing models from six candidate classifiers were selected, and performance was measured on holdout test sets. CIs were obtained by bootstrapping the test sets for 2000 random samples. Model accuracy score was compared with the no-information rate using the Wald test. Results The study cohort comprised 263 patients (mean age ± SD at diagnosis, 87 months ± 60; 166 boys). A two-stage classifier outperformed a single-stage multiclass classifier. The combined, sequential classifier achieved a microaveraged F1 score of 88% and a binary F1 score of 95% specifically for WNT. A group 3 versus group 4 classifier achieved an area under the receiver operating characteristic curve of 98%. Of the Image Biomarker Standardization Initiative features, texture and first-order intensity features were most contributory across the molecular subgroups. Conclusion An MRI-based machine learning decision path allowed identification of the four clinically relevant molecular pediatric medulloblastoma subgroups. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Chaudhary and Bapuraj in this issue.

Deep Learning for Automated Classification of Inferior Vena Cava Filter Types on Radiographs.

PURPOSE: To demonstrate the feasibility and evaluate the performance of a deep-learning convolutional neural network (CNN) classification model for automated identification of different types of inferior vena cava (IVC) filters on radiographs. MATERIALS AND METHODS: In total, 1,375 cropped radiographic images of 14 types of IVC filters were collected from patients enrolled in a single-center IVC filter registry, with 139 images withheld as a test set and the remainder used to train and validate the classification model. Image brightness, contrast, intensity, and rotation were varied to augment the training set. A 50-layer ResNet architecture with fixed pre-trained weights was trained using a soft margin loss over 50 epochs. The final model was evaluated on the test set. RESULTS: The CNN classification model achieved a F1 score of 0.97 (0.92-0.99) for the test set overall and of 1.00 for 10 of 14 individual filter types. Of the 139 test set images, 4 (2.9%) were misidentified, all mistaken for other filter types that appear highly similar. Heat maps elucidated salient features for each filter type that the model used for class prediction. CONCLUSIONS: A CNN classification model was successfully developed to identify 14 types of IVC filters on radiographs and demonstrated high performance. Further refinement and testing of the model is necessary before potential real-world application.

Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy.

BACKGROUND AND PURPOSE: Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin-labeling (ASL) perfusion magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective study was performed in 23 children with biopsy-proven LCH. Analysis was performed on routine brain MRI obtained before or after therapy. Region of interest (ROI) methodology was used to determine ASL cerebral blood flow (CBF) (mL/100 g/min) in the following bilateral regions: angular gyrus, anterior prefrontal cortex, orbitofrontal cortex, dorsal anterior cingulate cortex, and hippocampus. Quantile (median) regression was performed for each ROI location. CBF patterns were compared between pre- and posttreatment LCH patients as well as with age-matched healthy controls. RESULTS: Significantly reduced CBF was seen in posttreatment children with LCH compared to age-matched controls in angular gyrus (P = .046), anterior prefrontal cortex (P = .039), and dorsal anterior cingulate cortex (P = .023). Further analysis revealed dominant perfusion abnormalities in the right hemisphere. No significant perfusion differences were observed in the hippocampus or orbitofrontal cortex. CONCLUSION: Perfusion in specific cerebral regions may be consistently reduced in children with LCH, and may represent effects of underlying disease physiology and/or sequelae of chemotherapy. Studies that combine a formal cognitive assessment and hemodynamic data may further provide insight into perfusion deficits associated with the disease and the potential neurotoxic effects in children treated by chemotherapy.

Speech processing and plasticity in the right hemisphere predict variation in adult foreign language learning.

Foreign language learning in adulthood often takes place in classrooms where learning outcomes vary widely among students, for both initial learning and long-term retention. Despite the fundamental role of speech perception in first language acquisition, its role in foreign language learning outcomes remains unknown. Using a speech discrimination functional magnetic resonance imaging (fMRI) task and resting-state fMRI before and after an intensive, classroom-based, Mandarin Chinese course, we examined how variations in pre-training organization and pre-to-post reorganization of brain functions predicted successful language learning in male and female native English-speakers. Greater pre-training activation in right inferior frontal gyrus (IFG) to Mandarin speech was associated with better Mandarin attainment at the end of the course. After four weeks of class, learners showed overall increased activation in left IFG and left superior parietal lobule (SPL) to Mandarin speech, but in neither region was variation related to learning outcomes. Immediate attainment was associated with greater pre-to-post reduction of right IFG activation to Mandarin speech but also greater enhancement of resting-state connectivity between this region and both left IFG and left SPL. Long-term retention of Mandarin skills measured three months later was more accurately predicted by models using features of neural preparedness (pre-training activation) and neural plasticity (pre-to-post activation change) than models using behavior preparedness and plasticity features (pre-training speech discrimination accuracy and Mandarin attainment, respectively). These findings suggest that successful holistic foreign language acquisition in human adulthood requires right IFG engagement during initial learning but right IFG disengagement for long-term retention of language skills.

Evaluation of a Mobile Application for Pelvic Floor Exercises.

BACKGROUND: Pelvic floor exercises are effective in improving muscle strength and urinary incontinence symptoms. Increasingly popular mobile applications can be effective in teaching patients these exercises. INTRODUCTION: A mobile application, Bwom©, aims to educate women about pelvic floor exercises with individually tailored plans relevant to the user's risk factors. The objective of this study is to assess the understandability and actionability of Bwom. MATERIALS AND METHODS: This is a cross-sectional survey of patients and providers at an academic medical center. The survey utilized the Patient Education Material Assessment Tool (PEMAT) validated by the U.S. Department of Health Services, which provides scores on understandability and actionability. Participants completed an initial demographic survey, used Bwom for 2 weeks, and then completed the PEMAT tool. RESULTS: Twenty five patients and 22 providers participated in the study, for a total of 47 participants. Providers included gynecology residents and faculty (91%), pelvic floor physical therapists (5%), and other healthcare professionals (5%). The majority of patients were age 31-40 (70%) and Caucasian (55%). Thirty nine percent had not yet tried pelvic floor exercises on their own before the study. The mean understandability score was 93.8% (±11.7) and the mean actionability score was 91.7% (±16.3). DISCUSSION: This study paves the way for future investigations into the effectiveness of this app in decreasing symptoms of pelvic floor weakness and incontinence. CONCLUSIONS: This study demonstrates that Bwom shows promise as a mobile application to educate women about pelvic floor exercises by providing user-friendly actions in an understandable way.

Clinical Trials for Ductal Carcinoma In Situ of the Breast.

Ductal carcinoma in situ (DCIS) of the breast is a non-obligatory precursor to invasive breast carcinoma, with a variable natural history and biological potential for progression to invasive disease. Over the past 30 years, clinical trials have applied the therapeutic principles used for invasive carcinoma to treat DCIS (surgery, with or without breast radiotherapy, and post-operative endocrine therapy), with excellent survival outcomes, and in-breast recurrence rates that range from 0.5 to 1% annually. However, half of such recurrences are again in-situ lesions, and intensive therapy is likely not necessary for all patients. Current clinical research is focused on a better characterization of the potential of individual lesions to progress to invasive disease, and to identify women who would do well with lesser treatment. Three ongoing trials in the United States and Europe randomize women to active surveillance (with or without endocrine therapy) versus usual treatment with surgery and radiotherapy. The use of pre-operative endocrine therapy has been evaluated in a recently completed trial of letrozole use in postmenopausal women with DCIS; and in on-going trials of tamoxifen, used either orally, or as a 4-hydroxytamoxifen gel formulation for application to the breast skin. This review summaries the major past and current clinical trials of DCIS, and the likely trajectories of DCIS management in the near future.

Impaired Frontal-Limbic White Matter Maturation in Children at Risk for Major Depression.

Depression is among the most common neuropsychiatric disorders. It remains unclear whether brain abnormalities associated with depression reflect the pathological state of the disease or neurobiological traits predisposing individuals to depression. Parental history of depression is a risk factor that more than triples the risk of depression. We compared white matter (WM) microstructure cross-sectionally in 40 children ages 8-14 with versus without parental history of depression (At-Risk vs. Control). There were significant differences in age-related changes of fractional anisotropy (FA) between the groups, localized in the anterior fronto-limbic WM pathways, including the anterior cingulum and the genu of the corpus callosum. Control children exhibited typical increasing FA with age, whereas At-Risk children exhibited atypical decreasing FA with age in these fronto-limbic regions. Furthermore, dorsal cingulate FA significantly correlated with depressive symptoms for At-Risk children. The results suggest maturational WM microstructure differences in mood-regulatory neurocircuitry that may contribute to neurodevelopmental risk for depression. The study provides new insights into neurodevelopmental susceptibility to depression and related disabilities that may promote early preventive intervention approaches.

Irrigation after Laparoscopic Power Morcellation and the Dispersal of Leiomyoma Cells: A Pilot Study.

STUDY OBJECTIVE: To evaluate if copious irrigation and suctioning after electromechanical power morcellation will reduce myoma cell dissemination and if there is a difference between sterile water and normal saline. DESIGN: Prospective single-center cohort pilot study (Canadian Task Force classification II-2). SETTING: Academic tertiary referral center. PATIENTS: Sixteen women undergoing laparoscopic myomectomy with 1 surgeon between January 1, 2017 and August 31, 2017. INTERVENTIONS: Peritoneal washings were collected 3 specific times during surgery: after dissection of myoma(s) and hysterotomy repair but before morcellation, after morcellation, and after irrigation with 3 L normal saline or sterile water. The primary outcome was the detection of benign spindle cells (BSCs) in peritoneal washings. MEASUREMENTS AND MAIN RESULTS: Sixteen patients were enrolled in the study. Eight were randomized to the normal saline group and 8 to the sterile water group. In the normal saline group BSCs were detected in 3 of 8 patients (37.5%) after closure of the hysterotomy but before morcellation, in 3 of 8 (37.5%) after morcellation, and in 0 of 8 (0%) after irrigation and suctioning of the peritoneal cavity with 3 L normal saline. In the sterile water group BSCs were detected in 3 of 8 patients (37.5%) after closure of the hysterotomy but before morcellation, 2 of 8 (25%) after morcellation, and in 0 of 8 (0%) after irrigation and suctioning with 3 L sterile water. Thus, no differences were found between the normal saline and sterile water groups. CONCLUSION: In this pilot study myoma cells were disseminated before electromechanical morcellation. Irrigation and suctioning with 3 L normal saline or sterile water after morcellation may reduce myoma cell dissemination.

Pseudoamniotic Band Syndrome Post Fetal Thoracoamniotic Shunting for Bilateral Hydrothorax.

INTRODUCTION: Pseudoamniotic band syndrome (PABS) occurs iatrogenically after fetal surgery or amniocentesis due to chorioamniotic membrane separation. Separation of the amnion from the chorion can expand to form fibrous amniotic bands that can envelope fetal limbs or the umbilical cord, with consequences ranging from limb constriction to fetal demise. CASE REPORT: We report a case of bilateral fetal pleural effusions at 27 weeks' gestation treated by bilateral thoracoamniotic shunts. Following shunt placement, the hydrothorax resolved. However, chorioamniotic membrane separation developed resulting in PABS with subsequent umbilical cord strangulation and fetal demise at 32 weeks' gestation. CONCLUSION: PABS has been previously described in the literature following various fetal interventions. This is the first reported case of pseudoamniotic band syndrome after placement of fetal thoracoamniotic shunts. A high index of suspicion is required to diagnose PABS via postoperative ultrasound. Post intervention chorioamniotic membrane separation warrants close surveillance for sonographic evidence of PABS.

24-h multichannel intraluminal impedance-pH monitoring may be an inadequate test for detecting gastroesophageal reflux in patients with mixed typical and atypical symptoms.

BACKGROUND: The detection of gastroesophageal reflux (GERD) via pH testing is the key component of the evaluation of patients considered for antireflux surgery. Two common pH testing systems exist, a multichannel, intraluminal impedance-pH monitoring (MII-pH) catheter, and wireless (Bravo(®)) capsule; however, discrepancies between the two systems exist. In patients with atypical symptoms, MII-pH catheter is often used preferentially. We aimed to elucidate the magnitude of this discrepancy and to assess the diagnostic value of MII-pH and the Bravo wireless capsule in a population of patients with mixed respiratory and typical symptoms. METHODS: The study population consisted of 66 patients tested with MII-pH and Bravo pH testing within 90 days between July 2009 and 2013. All patients presented with laryngo-pharyngo-respiratory (LPR) symptoms. Patient demographics, symptomatology, manometric and endoscopic findings, and pH monitoring parameters were analyzed. Patients were divided into four comparison groups: both pH tests positive, MII-pH negative/Bravo positive, MII-pH positive/Bravo negative, and both pH tests negative. RESULTS: Nearly half of the patients (44%) had discordant pH test results. Of these, 90% (26/29) had a negative MII-pH but positive Bravo study. In this group, the difference in the DeMeester score was large, a median of 29.3. These patients had a higher BMI (28.5 vs. 26.1, p = 0.0357), were more likely to complain of heartburn (50 vs. 23%, p = 0.0110), to have a hiatal hernia, (85 vs. 53%, p = 0.0075) and a structurally defective lower esophageal sphincter (LES, 85 vs. 58%, p = 0.0208). CONCLUSIONS: In patients with LPR symptoms, we found a high prevalence of discordant esophageal pH results, most commonly a negative MII-pH catheter and positive Bravo. As these patients exhibited characteristics consistent with GERD (heartburn, defective LES, hiatal hernia), the Bravo results are likely true. A 24-h MII-pH catheter study may be inadequate to diagnose GERD in this patient population.

Modeling healthy male white matter and myelin development: 3 through 60months of age.

An emerging hypothesis in developmental and behavioral disorders is that they arise from disorganized brain messaging or reduced connectivity. Given the importance of myelin to efficient brain communication, characterization of myelin development in infancy and childhood may provide salient information related to early connectivity deficits. In this work, we investigate regional and whole brain growth trajectories of the myelin water fraction, a quantitative magnetic resonance imaging measure sensitive and specific to myelin content, in data acquired from 122 healthy male children from 3 to 60months of age. We examine common growth functions to find the most representative model of myelin maturation and subsequently use the best of these models to develop a continuous population-averaged, four-dimensional model of normative myelination. Through comparisons with an independent sample of 63 male children across the same age span, we show that the developed model is representative of this population. This work contributes to understanding the trajectory of myelination in healthy infants and toddlers, furthering our knowledge of early brain development, and provides a model that may be useful for identifying developmental abnormalities.

Identification of cyclic GMP-activated nonselective Ca2+-permeable cation channels and associated CNGC5 and CNGC6 genes in Arabidopsis guard cells.

Cytosolic Ca(2+) in guard cells plays an important role in stomatal movement responses to environmental stimuli. These cytosolic Ca(2+) increases result from Ca(2+) influx through Ca(2+)-permeable channels in the plasma membrane and Ca(2+) release from intracellular organelles in guard cells. However, the genes encoding defined plasma membrane Ca(2+)-permeable channel activity remain unknown in guard cells and, with some exceptions, largely unknown in higher plant cells. Here, we report the identification of two Arabidopsis (Arabidopsis thaliana) cation channel genes, CNGC5 and CNGC6, that are highly expressed in guard cells. Cytosolic application of cyclic GMP (cGMP) and extracellularly applied membrane-permeable 8-Bromoguanosine 3',5'-cyclic monophosphate-cGMP both activated hyperpolarization-induced inward-conducting currents in wild-type guard cells using Mg(2+) as the main charge carrier. The cGMP-activated currents were strongly blocked by lanthanum and gadolinium and also conducted Ba(2+), Ca(2+), and Na(+) ions. cngc5 cngc6 double mutant guard cells exhibited dramatically impaired cGMP-activated currents. In contrast, mutations in CNGC1, CNGC2, and CNGC20 did not disrupt these cGMP-activated currents. The yellow fluorescent protein-CNGC5 and yellow fluorescent protein-CNGC6 proteins localize in the cell periphery. Cyclic AMP activated modest inward currents in both wild-type and cngc5cngc6 mutant guard cells. Moreover, cngc5 cngc6 double mutant guard cells exhibited functional abscisic acid (ABA)-activated hyperpolarization-dependent Ca(2+)-permeable cation channel currents, intact ABA-induced stomatal closing responses, and whole-plant stomatal conductance responses to darkness and changes in CO2 concentration. Furthermore, cGMP-activated currents remained intact in the growth controlled by abscisic acid2 and abscisic acid insensitive1 mutants. This research demonstrates that the CNGC5 and CNGC6 genes encode unique cGMP-activated nonselective Ca(2+)-permeable cation channels in the plasma membrane of Arabidopsis guard cells.

Obesity and contraception.

Utilizing contraception is critical in preventing unintended pregnancies among obese women. However, clinicians and obese patients may be unclear about which contraceptive methods are optimal. This review discusses the literature on any weight gain associated with contraceptive use, contraceptive efficacy among obese women, and special considerations for contraceptive method selection for women after bariatric surgery. The review also covers new findings on oral emergency contraception and obesity.

Pediatric neuroimaging using magnetic resonance imaging during non-sedated sleep.

BACKGROUND: Etiological studies of many neurological and psychiatric disorders are increasingly turning toward longitudinal investigations of infant brain development in order to discern predisposing structural and/or functional differences prior to the onset of overt clinical symptoms. While MRI provides a noninvasive window into the developing brain, MRI of infants and toddlers is challenging due to the modality's extreme motion sensitivity and children's difficulty in remaining still during image acquisition. OBJECTIVE: Here, we outline a broad research protocol for successful MRI of children under 4 years of age during natural, non-sedated sleep. MATERIALS AND METHODS: All children were imaged during natural, non-sedated sleep. Active and passive measures to reduce acoustic noise were implemented to reduce the likelihood of the children waking up during acquisition. Foam cushions and vacuum immobilizers were used to limit intra-scan motion artifacts. RESULTS: More than 380 MRI datasets have been successfully acquired from 220 children younger than 4 years of age within the past 39 months. Implemented measures permitted children to remain asleep for the duration of the scan and allowed the data to be acquired with an overall 97% success rate. CONCLUSION: The proposed method greatly advances current pediatric imaging techniques and may be readily implemented in other research and clinical settings to facilitate and further improve pediatric neuroimaging.

Laparoscopic management of short-interval interstitial pregnancy after recent tubal ectopic pregnancy: A case report.

A 24-year-old woman, G6P2032, initially presented with a right-sided ruptured tubal ectopic pregnancy. Salpingectomy was performed with care to completely remove the fallopian tube. The patient then presented with ipsilateral interstitial pregnancy 11 weeks later and initially underwent systemic methotrexate injection, which failed to resolve the pregnancy. She then underwent laparoscopic cornuostomy and dilation and curettage. Cornuostomy was performed with injection of dilute vasopressin around the gestational sac to help minimize blood loss, followed by hydrodissection and sharp dissection to remove the pregnancy. Judicial electrocautery was used and the myometrium and serosa were closed in layers. Attention was given to preserve uterine myometrial tissue integrity at the cornua. The patient recovered and was discharged. Her beta-hCG level trended from 11,902 mIU/mL pre-surgery to 7726 on postoperative day 0, and 289 on postoperative day 7. Pathology from the interstitial region showed fragments of chorionic villi, and the dilation and curettage pathology demonstrated decidualized secretory endometrium. Short-interval interstitial ectopic pregnancies after prior salpingectomy for tubal ectopic pregnancy are extremely rare. This case demonstrated successful management with a minimally invasive laparoscopic cornuostomy. This case also displays that ipsilateral interstitial pregnancy can occur after salpingectomy even after care is taken to remove all visible portions of the fallopian tube. Thus, patients should be counseled carefully about the risks of short-interval pregnancy after a recent tubal ectopic pregnancy.

Disease characteristics, treatments, and outcomes of patients with pulmonary arterial hypertension treated with selexipag in real-world settings from the SPHERE registry (SelexiPag: tHe usErs dRug rEgistry).

BACKGROUND: Selexipag is an oral prostacyclin receptor agonist, indicated for pulmonary arterial hypertension to delay disease progression and reduce the risk of pulmonary arterial hypertension-related hospitalization. SelexiPag: tHe usErs dRug rEgistry (NCT03278002) was a US-based, prospective, real-world registry of selexipag-treated patients. METHODS: Adults with pulmonary hypertension (enrolled 2016-2020) prescribed selexipag were followed for ≤18 months, with data collected at routine clinic visits. Patients were defined as newly or previously initiated if they had started selexipag ≤60 days or >60 days, respectively, before enrollment. RESULTS: The registry included 829 patients (430 newly initiated, 399 previously initiated; 759 with pulmonary arterial hypertension), of whom 55.6% were World Health Organization functional class (FC) 3/4; 57.3% were intermediate or high risk per Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0. In patients with pulmonary arterial hypertension, 18-month discontinuation rates for adverse events were 22.0%, 32.0%, and 11.9%, and 18-month survival rates were 89.4%, 84.2%, and 94.5% in the overall, newly, and previously initiated patient populations, respectively. From baseline to month 18, most patients had stable or improved FC and stable or improved REVEAL 2.0 risk category status. Discontinuation for adverse events, hospitalization, and survival were similar regardless of patients' individually tolerated selexipag maintenance dose. No new safety signals were identified. CONCLUSIONS: In this real-world analysis of patients initiating selexipag, most patients had stable or improved FC and REVEAL 2.0 risk category. Similar to the GRIPHON trial, outcomes with selexipag in this real-world study were comparable across maintenance dose strata, with no new safety signals.

An international study presenting a federated learning AI platform for pediatric brain tumors.

While multiple factors impact disease, artificial intelligence (AI) studies in medicine often use small, non-diverse patient cohorts due to data sharing and privacy issues. Federated learning (FL) has emerged as a solution, enabling training across hospitals without direct data sharing. Here, we present FL-PedBrain, an FL platform for pediatric posterior fossa brain tumors, and evaluate its performance on a diverse, realistic, multi-center cohort. Pediatric brain tumors were targeted due to the scarcity of such datasets, even in tertiary care hospitals. Our platform orchestrates federated training for joint tumor classification and segmentation across 19 international sites. FL-PedBrain exhibits less than a 1.5% decrease in classification and a 3% reduction in segmentation performance compared to centralized data training. FL boosts segmentation performance by 20 to 30% on three external, out-of-network sites. Finally, we explore the sources of data heterogeneity and examine FL robustness in real-world scenarios with data imbalances.

Breastfeeding and early white matter development: A cross-sectional study.

Does breastfeeding alter early brain development? The prevailing consensus from large epidemiological studies posits that early exclusive breastfeeding is associated with improved measures of IQ and cognitive functioning in later childhood and adolescence. Prior morphometric brain imaging studies support these findings, revealing increased white matter and sub-cortical gray matter volume, and parietal lobe cortical thickness, associated with IQ, in adolescents who were breastfed as infants compared to those who were exclusively formula-fed. Yet it remains unknown when these structural differences first manifest and when developmental differences that predict later performance improvements can be detected. In this study, we used quiet magnetic resonance imaging (MRI) scans to compare measures of white matter microstructure (mcDESPOT measures of myelin water fraction) in 133 healthy children from 10 months through 4 years of age, who were either exclusively breastfed a minimum of 3 months; exclusively formula-fed; or received a mixture of breast milk and formula. We also examined the relationship between breastfeeding duration and white matter microstructure. Breastfed children exhibited increased white matter development in later maturing frontal and association brain regions. Positive relationships between white matter microstructure and breastfeeding duration are also exhibited in several brain regions, that are anatomically consistent with observed improvements in cognitive and behavioral performance measures. While the mechanisms underlying these structural differences remains unclear, our findings provide new insight into the earliest developmental advantages associated with breastfeeding, and support the hypothesis that breast milk constituents promote healthy neural growth and white matter development.

Use of a point-of-care test to rapidly assess levels of SARS-CoV-2 nasal neutralising antibodies in vaccines and breakthrough infected individuals.

Despite SARS-CoV-2 vaccines eliciting systemic neutralising antibodies (nAbs), breakthrough infections still regularly occur. Infection helps to generate mucosal immunity, possibly reducing disease transmission. Monitoring mucosal nAbs is predominantly restricted to lab-based assays, which have limited application to the public. In this multi-site study, we used lateral-flow surrogate neutralisation tests to measure mucosal and systemic nAbs in vaccinated and breakthrough infected individuals in Australia and Singapore. Using three lateral flow assays to detect SARS-CoV-2 nAbs, we demonstrated that nasal mucosal nAbs were present in 71.4 (95% CI 56.3-82.9%) to 85.7% (95% CI 71.8-93.7%) of individuals with breakthrough infection (positivity rate was dependent upon the type of test), whereas only 20.7 (95% CI 17.1-49.4%) to 34.5% (95% CI 19.8-52.7%) of vaccinated individuals without breakthrough infection had detectible nasal mucosal nAbs. Of the individuals with breakthrough infection, collective mucosal anti-S antibody detection in confirmatory assays was 92.9% (95% CI 80.3-98.2%) of samples, while 72.4% (95% CI 54.1-85.5%) of the vaccinated individuals who had not experienced a breakthrough infection were positive to anti-S antibody. All breakthrough infected individuals produced systemic anti-N antibodies; however, these antibodies were not detected in the nasal cavity. Mucosal immunity is likely to play a role in limiting the transmission of SARS-CoV-2 and lateral flow neutralisation tests provide a rapid readout of mucosal nAbs at the point-of-care.