Measured proton electromagnetic structure deviates from theoretical predictions.

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities1 that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities2 map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades2. Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

Chronic arsenic poisoning: A sinister cause of peripheral neuropathy in a young couple.

ABSTRACT: Arsenic compounds are colorless and odorless and toxicity can occur either acutely following ingestion of arsenicals with gastrointestinal disturbances or due to chronic exposure usually presenting with dermatologic lesions and peripheral neuropathy. We report a young couple who presented with signs and symptoms of painful sensorimotor peripheral neuropathy in a typical "stocking and glove" pattern. They had raised urinary arsenic levels with normal blood levels and thus, a diagnosis of chronic arsenic poisoning due to contaminated water intake was made after detecting elevated arsenic levels in their home water supply. Both patients underwent chelation therapy with dimercaprol for 14 days and reported subjective and objective improvement in symptoms with the reduction in urinary arsenic levels at the end of therapy.

Utilization of Screening Mammography in Women Before 50: Cross-Sectional Survey Results from the National Health Interview Survey.

OBJECTIVE: While the American College of Radiology recommends annual screening mammography starting at age 40 years, the US Preventive Services Task Force (USPSTF) recommends that screening mammography in women younger than age 50 years should involve shared- decision making (SDM) between clinicians and patients, considering benefits and potential harms in younger women. Using a nationally representative cross-sectional survey, we aimed to evaluate patient-reported reasons and predictors of screening mammography utilization in this age group. METHODS: Respondents aged 40-49 years from the 2018 National Health Interview Survey (NHIS) without a history of breast cancer were included (response rate 64%). Participants reported sociodemographic variables and reasons they did not engage in mammography screening within the last two years. Multiple variable logistic regression analyses were performed to evaluate the association between sociodemographic characteristics and patient-reported screening mammography use, accounting for complex survey sampling design elements. RESULTS: 1,948 women between the ages of 40-49 years were included. Of this group, (758/1948) 46.6% reported receiving a screening mammogram within the last year, and 1196/1948 (61.4%) reported receiving a screening mammogram within the last two years. The most common reasons for not undergoing screening included: "No reason/never thought about it" 744/1948 (38.2%), "Put it off" 343/1948 (17.6%), "Didn't need it" 331/1948 (16.9%), "Doctor didn't order it" 162/1948 (8.3%), and "I'm too young" 63/1948 (5.3%). Multiple variable analyses demonstrated that lack of health insurance was the strongest predictor of mammography non-engagement (p< 0.001). CONCLUSION: Deficits in shared- decision-making in women younger than 50 years related to mammography utilization exist. Radiologists may be key in addressing this issue among ambulatory care providers and patients, educating about the benefits and harms of screening younger women, particularly in racial/ethnic minorities and uninsured patients, who experience additional barriers to care and SDM discussions.

Neuroimaging in the Era of Artificial Intelligence: Current Applications.

Background: Artificial intelligence (AI) in medicine has shown significant promise, particularly in neuroimaging. AI increases efficiency and reduces errors, making it a valuable resource for physicians. With the increasing amount of data processing and image interpretation required, the ability to use AI to augment and aid the radiologist could improve the quality of patient care. Observations: AI can predict patient wait times, which may allow more efficient patient scheduling. Additionally, AI can save time for repeat magnetic resonance neuroimaging and reduce the time spent during imaging. AI has the ability to read computed tomography, magnetic resonance imaging, and positron emission tomography with reduced or without contrast without significant loss in sensitivity for detecting lesions. Neuroimaging does raise important ethical considerations and is subject to bias. It is vital that users understand the practical and ethical considerations of the technology. Conclusions: The demonstrated applications of AI in neuroimaging are numerous and varied, and it is reasonable to assume that its implementation will increase as the technology matures. AI's use for detecting neurologic conditions holds promise in combatting ever increasing imaging volumes and providing timely diagnoses.

Role of 3D Printing and Modeling to Aid in Neuroradiology Education for Medical Trainees.

BACKGROUND: Applications of 3-dimensional (3D) printing in medical imaging and health care are expanding. Currently, primary uses involve presurgical planning and patient and medical trainee education. Neuroradiology is a complex subdiscipline of radiology that requires further training beyond radiology residency. This review seeks to explore the clinical value of 3D printing and modeling specifically in enhancing neuroradiology education for radiology physician residents and medical trainees. METHODS: A brief review summarizing the key steps from radiologic image to 3D printed model is provided, including storage of computed tomography and magnetic resonance imaging data as digital imaging and communications in medicine files; conversion to standard tessellation language (STL) format; manipulation of STL files in interactive medical image control system software (Materialise) to create 3D models; and 3D printing using various resins via a Formlabs 2 printer. RESULTS: For the purposes of demonstration and proof of concept, neuroanatomy models deemed crucial in early radiology education were created via open-source hardware designs under free or open licenses. 3D-printed objects included a sphenoid bone, cerebellum, skull base, middle ear labyrinth and ossicles, mandible, circle of Willis, carotid aneurysm, and lumbar spine using a combination of clear, white, and elastic resins. CONCLUSIONS: Based on this single-institution experience, 3D-printed complex neuroanatomical structures seem feasible and may enhance resident education and patient safety. These same steps and principles may be applied to other subspecialties of radiology. Artificial intelligence also has the potential to advance the 3D process.

Artificial Intelligence: Review of Current and Future Applications in Medicine.

BACKGROUND: The role of artificial intelligence (AI) in health care is expanding rapidly. Currently, there are at least 29 US Food and Drug Administration-approved AI health care devices that apply to numerous medical specialties and many more are in development. OBSERVATIONS: With increasing expectations for all health care sectors to deliver timely, fiscally-responsible, high-quality health care, AI has potential utility in numerous areas, such as image analysis, improved workflow and efficiency, public health, and epidemiology, to aid in processing large volumes of patient and medical data. In this review, we describe basic terminology, principles, and general AI applications relating to health care. We then discuss current and future applications for a variety of medical specialties. Finally, we discuss the future potential of AI along with the potential risks and limitations of current AI technology. CONCLUSIONS: AI can improve diagnostic accuracy, increase patient safety, assist with patient triage, monitor disease progression, and assist with treatment decisions.

Using Artificial Intelligence for COVID-19 Chest X-ray Diagnosis.

BACKGROUND: Coronavirus disease-19 (COVID-19), caused by a novel member of the coronavirus family, is a respiratory disease that rapidly reached pandemic proportions with high morbidity and mortality. In only a few months, it has had a dramatic impact on society and world economies. COVID-19 has presented numerous challenges to all aspects of health care, including reliable methods for diagnosis, treatment, and prevention. Initial efforts to contain the spread of the virus were hampered by the time required to develop reliable diagnostic methods. Artificial intelligence (AI) is a rapidly growing field of computer science with many applications for health care. Machine learning is a subset of AI that uses deep learning with neural network algorithms. It can recognize patterns and achieve complex computational tasks often far quicker and with increased precision than can humans. METHODS: In this article, we explore the potential for the simple and widely available chest X-ray (CXR) to be used with AI to diagnose COVID-19 reliably. Microsoft CustomVision is an automated image classification and object detection system that is a part of Microsoft Azure Cognitive Services. We utilized publicly available CXR images for patients with COVID-19 pneumonia, pneumonia from other etiologies, and normal CXRs as a dataset to train Microsoft CustomVision. RESULTS: Our trained model overall demonstrated 92.9% sensitivity (recall) and positive predictive value (precision), with results for each label showing sensitivity and positive predictive value at 94.8% and 98.9% for COVID-19 pneumonia, 89% and 91.8% for non-COVID-19 pneumonia, 95% and 88.8% for normal lung. We then validated the program using CXRs of patients from our institution with confirmed COVID-19 diagnoses along with non-COVID-19 pneumonia and normal CXRs. Our model performed with 100% sensitivity, 95% specificity, 97% accuracy, 91% positive predictive value, and 100% negative predictive value. CONCLUSIONS: We have used a readily available, commercial platform to demonstrate the potential of AI to assist in the successful diagnosis of COVID-19 pneumonia on CXR images. The findings have implications for screening and triage, initial diagnosis, monitoring disease progression, and identifying patients at increased risk of morbidity and mortality. Based on the data, a website was created to demonstrate how such technologies could be shared and distributed to others to combat entities such as COVID-19 moving forward.

Proliferation and differentiation of mesenchymal stem cells on scaffolds containing chitosan, calcium polyphosphate and pigeonite for bone tissue engineering.

OBJECTIVES: Treatment of critical-sized bone defects with cells and biomaterials offers an efficient alternative to traditional bone grafts. Chitosan (CS) is a natural biopolymer that acts as a scaffold in bone tissue engineering (BTE). Polyphosphate (PolyP), recently identified as an inorganic polymer, acts as a potential bone morphogenetic material, whereas pigeonite (Pg) is a novel iron-containing ceramic. In this study, we prepared and characterized scaffolds containing CS, calcium polyphosphate (CaPP) and Pg particles for bone formation in vitro and in vivo. MATERIALS AND METHODS: Chitosan/CaPP scaffolds and CS/CaPP scaffolds containing varied concentrations of Pg particles (0.25%, 0.5%, 0.75% and 1%) were prepared and characterized by SEM, XRD, EDAX, FT-IR, degradation, protein adsorption, mechanical strength and biomineralization studies. The cytocompatibility of these scaffolds with mouse mesenchymal stem cells (mMSCs, C3H10T1/2) was determined by MTT assay and fluorescence staining. Cell proliferation on scaffolds was assessed using MUSE™ (Merck-Millipore, Germany) cell analyser. The effect of scaffolds on osteoblast differentiation at the cellular level was evaluated by Alizarin red (AR) and alkaline phosphatase (ALP) staining. At the molecular level, the expression of osteoblast differentiation marker genes such as Runt-related transcription factor-2 (Runx2), ALP, type I collagen-1 (Col-I) and osteocalcin (OC) was determined by real-time reverse transcriptase (RT-PCR) analysis. Bone regeneration was assessed by X-ray radiographs, SEM and EDAX analyses, and histological staining such as haematoxylin and eosin staining and Masson's trichrome staining (MTS) in a rat critical-sized tibial defect model system. RESULTS: The inclusion of iron-containing Pg particles at 0.25% concentration in CS/CaPP scaffolds showed enhanced bioactivity by protein adsorption and biomineralization, compared with that shown by CS/CaPP scaffolds alone. Increased proliferation of mMSCs was observed with CS/CaPP/Pg scaffolds compared with control and CS/CaPP scaffolds. Increase in cell proliferation was accompanied by G0/G1 to G2/M phase transition with increased levels of cyclin(s) A, B and C. Pg particles in CS/CaPP scaffolds enhanced osteoblast differentiation at the cellular and molecular levels, as evidenced by increased calcium deposits, ALP activity and expression of osteoblast marker genes. In vivo implantation of scaffolds in rat critical-sized tibial defects displayed accelerated bone formation after 8 weeks. CONCLUSION: The current findings indicate that CS/CaPP scaffolds containing iron-containing Pg particles serve as an appropriate template to support proliferation and differentiation of MSCs to osteoblasts in vitro and bone formation in vivo and thus support their candidature for BTE applications.

A Case Report on Varenicline Induced Delirium in an Alcohol and Nicotine Dependent Patient.

Varenicline is a smoking cessation agent. Varenicline acts as a partial agonist of α4ß2 neuronal nicotinic acetylcholine receptor and prevents nicotine binding to the same. It also causes dopamine (DA) stimulation that decreases craving and symptoms of dependence. A 40-year-old male diagnosed with alcohol and nicotine dependence syndrome was treated with 1 mg of varenicline for 3 days. Patient developed episodes of transient delirium within 15-30 min after administration of varenicline. Patient was disoriented and did not respond relevantly. Patient would have disorientation and would respond irrelevantly and was unable to recall the event completely. There were no features suggestive of seizures. The episodes resolved after the medication was stopped. Varenicline, with its partial agonistic effect on nicotinergic receptors, stimulates the release of multiple neurotransmitters including DA. DA dysregulation is probably responsible for the development of neuropsychiatric adverse reactions due to varenicline. This is the first case report to the best of our knowledge reporting varenicline induced dilirium. In this case, the adverse event was found in an alcohol and nicotine dependent patient undergoing treatment. It is essential to monitor uncommon adverse effects as this can cause significant morbidity.

Prediction of digoxin treatment failure in infants with supraventricular tachycardia: role of transesophageal pacing.

Transesophageal atrial pacing was used to initiate and terminate tachycardia in 24 infants (seven female and 17 male, aged 1 to 34 days) with ECG documentation of supraventricular tachycardia. Six infants received no chronic treatment, and chronic oral digoxin prophylaxis was administered to 18 infants in an effort to prevent recurrences of tachycardia. In these 18 infants, the effectiveness of digoxin therapy in preventing the initiation of tachycardia by transesophageal pacing was compared with its ability to prevent spontaneous recurrences of supraventricular tachycardia. While receiving chronic oral digoxin therapy, tachycardia could be reinitiated in 15/18 (83%) infants. In these infants, the cycle length of tachycardia and the atrioventricular interval were the same before and during chronic digoxin treatment. Three infants in whom tachycardia could not be initiated during chronic digoxin therapy had no spontaneous recurrences during 6 months of follow-up, whereas 10/15 (67%) infants in whom tachycardia could be reinitiated had clinically significant recurrences in spite of chronic digoxin therapy. Six infants who received no chronic drug treatment had no documented recurrences during 6 months of follow-up. This study demonstrates that digoxin was effective in preventing significant spontaneous recurrences of supraventricular tachycardia in only 8/18 (44%) infants treated with digoxin. The ability to initiate supraventricular tachycardia with transesophageal pacing may be useful in determining which digoxin-treated infants are at risk for recurrence. Finally, not all infants with supraventricular tachycardia require chronic prophylaxis; six of the untreated infants had no documented recurrences.

Frequent hypomethylation in Wilms tumors of pericentromeric DNA in chromosomes 1 and 16.

Rearrangements in the pericentromeric heterochromatin of chromosome 1 or 16 are often found in many types of cancers, including Wilms tumors, and have been suggested to contribute to oncogenesis or tumor progression. The oncogenic potential of these rearrangements has been ascribed to the resulting chromosome arm imbalances affecting the dosage of tumor suppressor genes or protooncogenes. Because DNA hypomethylation has been linked to rearrangements in the pericentromeric regions of chromosome 1 and 16 in two types of non-cancer cell populations, we examined methylation of normally highly methylated satellite DNA sequences in these regions in Wilms tumors. Hypomethylation was found to be frequent in juxtacentromeric (satellite 2) sequences and, especially, in centromeric (satellite alpha) sequences of chromosome 1. Hypomethylation of satellite 2 DNA of chromosome 16 showed a high degree of concordance with that of satellite 2 DNA of chromosome 1. We discuss the relationship of this satellite DNA hypomethylation in Wilms tumors to chromosome aberrations, as determined by assays for loss of heterozygosity.

Satellite DNA hypomethylation vs. overall genomic hypomethylation in ovarian epithelial tumors of different malignant potential.

Rearrangements in heterochromatin in the vicinity of the centromeres of chromosomes 1 and 16 are frequent in many types of cancer, including ovarian epithelial carcinomas. Satellite 2 DNA is the main sequence in the unusually long heterochromatin region adjacent to the centromere of each of these chromosomes. Rearrangements in these regions and hypomethylation of satellite 2 DNA are a characteristic feature of patients with a rare recessive genetic disease, ICF (immunodeficiency, centromeric region instability, and facial anomalies). In all normal tissues of postnatal somatic origin, satellite 2 DNA is highly methylated. We examined satellite 2 DNA methylation in ovarian tumors of different malignant potential, namely, ovarian cystadenomas, low malignant potential (LMP) tumors, and epithelial carcinomas. Most of the carcinomas and LMP tumors exhibited hypomethylation in satellite 2 DNA of both chromosomes 1 and 16. A comparison of methylation of these sequences in the three types of ovarian neoplasms demonstrated that there was a statistically significant correlation between the extent of this satellite DNA hypomethylation and the degree of malignancy (P<0.01). Also, there was a statistically significant association (P<0.005) between genome-wide hypomethylation and undermethylation of satellite 2 DNA among these 17 tumors. In addition, we found abnormal hypomethylation of satellite alpha DNA in the centromere of chromosome 1 in many of these tumors. Our findings are consistent with the hypothesis that one of the ways that genome-wide hypomethylation facilitates tumor development is that it often includes satellite hypomethylation which might predispose cells to structural and numerical chromosomal aberrations. Several of the proteins that bind to pericentromeric heterochromatin are known to be sensitive to the methylation status of their target sequences and so could be among the sensors for detecting abnormal demethylation and mediating effects on chromosome structure and stability.

Hypersensitivity to radiation-induced non-apoptotic and apoptotic death in cell lines from patients with the ICF chromosome instability syndrome.

Immunodeficiency, centromeric region instability, and facial anomalies (ICF), a rare recessive chromosome instability syndrome, involves the loss of DNA methyltransferase 3B activity and the consequent hypomethylation of a small portion of the genome. We demonstrate for the first time that ICF cells are strongly hypersensitive to a genotoxic agent, namely, ionizing radiation. However, unlike cell lines from patients with ataxia telangiectasia or Nijmegen breakage syndrome, chromosome instability syndromes also associated with unusual sensitivity to ionizing radiation, ICF cells did not show any deficiencies in their cell cycle checkpoints. ICF lymphoblastoid cell lines demonstrated increased apoptosis, long-term cell cycle arrest, and loss of viability in clonogenicity assays after irradiation compared to analogous normal cell lines. Also, the ICF cell lines were subject to high frequencies of rapid non-apoptotic cell death upon irradiation but not to abnormally high levels of radiation-induced, cytogenetically detectable chromosome abnormalities. ICF-associated undermethylation of some regulatory gene(s) might lead to an exaggerated response to radiation-induced breaks in DNA yielding increased rates of cell death and irreversible cell cycle arrest. As a defense against their frequent spontaneous breaks in chromosomes 1 and 16, ICF patients may be abnormally prone to chromosome break-induced apoptosis, non-apoptotic cell death, and permanent cell cycle arrest so as to minimize the number of cycling cells with spontaneous rearrangements. A similarly increased cell death and cycle-arrest response to chromosome breaks due to cancer-linked DNA hypomethylation might occur during carcinogenesis.

Expanded polytetra fluoroethylene (PTFE) graft in hemodialysis.

Currently, PTFE grafts are regarded to be the alternative method of choice for patients with failed conventional fistulae. Observation over a longer period is necessary to assess the long term patency rate. Our experience in the use of PTFE grafts in providing vascular access for selected patients is reviewed. Thirty grafts were implanted in twenty-six patients over a sixteen-month period. Complications noted were thrombosis (six patients) and infection (two). Twenty patients were successfully hemodialysed without complications. Two additional patients had access provided for long term parenteral therapy or transfusion.