Cerebral Venous Thrombosis in COVID-19: A New York Metropolitan Cohort Study

BACKGROUND AND PURPOSE

Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection is associated with hypercoagulability. We sought to evaluate the demographic and clinical characteristics of cerebral venous thrombosis among patients hospitalized for coronavirus disease 2019 (COVID-19) at 6 tertiary care centers in the New York City metropolitan area.

MATERIALS AND METHODS

We conducted a retrospective multicenter cohort study of 13,500 consecutive patients with COVID-19 who were hospitalized between March 1 and May 30, 2020.

RESULTS

Of 13,500 patients with COVID-19, twelve had imaging-proved cerebral venous thrombosis with an incidence of 8.8 per 10,000 during 3 months, which is considerably higher than the reported incidence of cerebral venous thrombosis in the general population of 5 per million annually. There was a male preponderance (8 men, 4 women) and an average age of 49 years (95% CI, 36-62 years; range, 17-95 years). Only 1 patient (8%) had a history of thromboembolic disease. Neurologic symptoms secondary to cerebral venous thrombosis occurred within 24 hours of the onset of the respiratory and constitutional symptoms in 58% of cases, and 75% had venous infarction, hemorrhage, or both on brain imaging. Management consisted of anticoagulation, endovascular thrombectomy, and surgical hematoma evacuation. The mortality rate was 25%.

CONCLUSIONS

Early evidence suggests a higher-than-expected frequency of cerebral venous thrombosis among patients hospitalized for COVID-19. Cerebral venous thrombosis should be included in the differential diagnosis of neurologic syndromes associated with SARS-CoV-2 infection.

Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd_{2}As_{2}

As exemplified by the growing interest in the quantum anomalous Hall effect, the research on topology as an organizing principle of quantum matter is greatly enriched from the interplay with magnetism. In this vein, we present a combined electrical and thermoelectrical transport study on the magnetic Weyl semimetal EuCd_{2}As_{2}. Unconventional contribution to the anomalous Hall and anomalous Nernst effects were observed both above and below the magnetic transition temperature of EuCd_{2}As_{2}, indicating the existence of significant Berry curvature. EuCd_{2}As_{2} represents a rare case in which this unconventional transverse transport emerges both above and below the magnetic transition temperature in the same material. The transport properties evolve with temperature and field in the antiferromagnetic phase in a different manner than in the paramagnetic phase, suggesting different mechanisms to their origin. Our results indicate EuCd_{2}As_{2} is a fertile playground for investigating the interplay between magnetism and topology, and potentially a plethora of topologically nontrivial phases rooted in this interplay.

Cylinder-flat-surface contact mechanics during sliding

Using molecular dynamics we study the dependency of the contact mechanics on the sliding speed when an elastic block (cylinder) with a cos(q_{0}x) surface height profile is sliding in adhesive contact on a rigid flat substrate. The atoms on the block interact with the substrate atoms by Lennard-Jones potentials, and we consider both commensurate and (nearly) incommensurate contacts. For the incommensurate system the friction force fluctuates between positive and negative values, with an amplitude proportional to the sliding speed, but with the average close to zero. For the commensurate system the (time-averaged) friction force is much larger and nearly velocity independent. For both types of systems the width of the contact region is velocity independent even when, for the commensurate case, the frictional shear stress increases from zero (before sliding) to ≈0.1MPa during sliding. This frictional shear stress, and the elastic modulus used, are typical for polydimethylsiloxane rubber sliding on a glass surface, and we conclude that the reduction in the contact area observed in some experiments when increasing the tangential force must be due to effects not included in our model study, such as viscoelasticity or elastic nonlinearity.

Adhesion paradox: Why adhesion is usually not observed for macroscopic solids

The adhesion paradox refers to the observation that for most solid objects no adhesion can be detected when they are separated from a state of molecular contact. The adhesion paradox results from surface roughness, and we present experimental and theoretical results that show that adhesion in most cases is "killed" by the longest-wavelength roughness. In addition, adhesion experiments between a human finger and a clean glass plate were carried out, and for a dry finger no macroscopic adhesion occurred. We suggest that the observed decrease in the contact area with increasing shear force results from nonadhesive finger-glass contact mechanics, involving large deformations of complex layered material.

Costing Analysis of a Pilot Community Health Worker Program in Rural Nepal

Data from a retrospective costing analysis offers insights and practical considerations for policy makers and locally elected officials for designing and implementing a new community health work cadre as a mechanism to achieve SDG targets in Nepal.

Community health workers (CHWs) are essential to primary health care systems and are a cost-effective strategy to achieve the Sustainable Development Goals (SDGs). Nepal is strongly committed to universal health coverage and the SDGs. In 2017, the Nepal Ministry of Health and Population partnered with the nongovernmental organization Nyaya Health Nepal to pilot a program aligned with the 2018 World Health Organization guidelines for CHWs. The program includes CHWs who: (1) receive regular financial compensation; (2) meet a minimum education level; (3) are well supervised; (4) are continuously trained; (5) are integrated into local primary health care systems; (6) use mobile health tools; (7) have consistent supply chain; (8) live in the communities they serve; and (9) provide service without point-of-care user fees. The pilot model has previously demonstrated improved institutional birth rate, antenatal care completion, and postpartum contraception utilization. Here, we performed a retrospective costing analysis from July 16, 2017 to July 15, 2018, in a catchment area population of 60,000. The average per capita annual cost is US$3.05 (range: US$1.94 to US$4.70 across 24 villages) of which 74% is personnel cost. Service delivery and administrative costs and per beneficiary costs for all services are also described. To address the current discourse among Nepali policy makers at the local and federal levels, we also present 3 alternative implementation scenarios that policy makers may consider. Given the Government of Nepal’s commitment to increase health care spending (US$51.00 per capita) to 7.0% of the 2030 gross domestic product, paired with recent health care systems decentralization leading to expanded fiscal space in municipalities, this CHW program provides a feasible opportunity to make progress toward achieving universal health coverage and the health-related SDGs. This costing analysis offers insights and practical considerations for policy makers and locally elected officials for deploying a CHW cadre as a mechanism to achieve the SDG targets.

Community-based postpartum contraceptive counselling in rural Nepal: a mixed-methods evaluation

Unmet need for postpartum contraception in rural Nepal remains high and expanding access to sexual and reproductive healthcare is essential to achieving universal healthcare. We evaluated the impact of an integrated intervention that employed community health workers aided by mobile technology to deliver patient-centred, home-based antenatal and postnatal counselling on postpartum modern contraceptive use. This was a pre–post-intervention study in seven village wards in a single municipality in rural Nepal. The primary outcome was modern contraceptive use among recently postpartum women. We performed a multivariable logistic regression to examine contraceptive use among postpartum women pre- and one-year post-intervention. We conducted qualitative interviews to explore the implementation process. There were 445 postpartum women in the pre-intervention group and 508 in the post-intervention group. Modern contraceptive use increased from 29% pre-intervention to 46% post-intervention (p < 0.0001). Adjusting for age, caste, and household expenditure, time since delivery and sex of child in the index pregnancy, postpartum women one-year post-intervention had twice the odds (OR 2.3; CI 1.7, 3.1; p < 0.0001) of using a modern contraceptive method as compared to pre-intervention. Factors at the individual, family, and systems level influenced women’s contraceptive decisions. The intervention contributed to increasing contraceptive use through knowledge transfer, demand generation, referrals to healthcare facilities, and follow-up. A community-based, patient-centred contraceptive counselling intervention supported by mobile technology and integrated into longitudinal care delivered by community health workers appears to be an effective strategy for improving uptake of modern contraception among postpartum women in rural Nepal.

Deep Transfer Learning Based Classification Model for COVID-19 Disease

The COVID-19 infection is increasing at a rapid rate, with the availability of limited number of testing kits. Therefore, the development of COVID-19 testing kits is still an open area of research. Recently, many studies have shown that chest Computed Tomography (CT) images can be used for COVID-19 testing, as chest CT images show a bilateral change in COVID-19 infected patients. However, the classification of COVID-19 patients from chest CT images is not an easy task as predicting the bilateral change is defined as an ill-posed problem. Therefore, in this paper, a deep transfer learning technique is used to classify COVID-19 infected patients. Additionally, a top-2 smooth loss function with cost-sensitive attributes is also utilized to handle noisy and imbalanced COVID-19 dataset kind of problems. Experimental results reveal that the proposed deep transfer learning-based COVID-19 classification model provides efficient results as compared to the other supervised learning models.

P268 Anomalies of pulmonary arteries in Tetralogy of Fallot in developing countries: study of 100 cases in indian population

Introduction

Right ventricular outflow tract (RVOT) obstruction in some or other form is one of the major components of Tetralogy of Fallot. It can occur at any level, isolated or in combination, from Infundibulum (most common), Pulmonary valve, Main pulmonary artery, Right and Left pulmonary arteries and up to their segmental branches. Incidence of pulmonary artery anomalies are reported between 15-20%, though some reported as high as 40%. 

Purpose

 The objective of this retrospective  observational study is to determine the presence and degree of pulmonary artery  abnormalities and associated cardiac defects in patients with Tetralogy of Fallot and to  define the pulmonary arterial anatomy to guide the further surgical management.

Method

A total of 100 newly diagnosed or follow up cases of TOF irrespective of age (range 5 days- 32 years) and gender (32 female, 68 male) who were planned for surgical management and referred for evaluation of pulmonary artery anatomy. All patient underwent non-ECG gated CT pulmonary Angiography in Toshiba 64 slice CT scanner.  CT data was analyzed retrospectively to look for cardiac and pulmonary artery anatomy by one independent observer having experience in cardiac radiology.

Results

92 patient had infundibular and valvular stenosis and 8 patients has atretic pulmonary valve with additional supravalvar pulmonary stenosis in 17% patient. Out of total 100 patients, 35% had pulmonary artery abnormalities. This included 19 patient (19%) with isolated main pulmonary artery (MPA) abnormality, 6 % had isolated left pulmonary artery (LPA) abnormality, 2 had isolated right pulmonary artery abnormality, 4% had  combined MPA and LPA  abnormality, 2% had combined MPA and RPA abnormalities and 1% patient had all 3 (MPA,LPA,RPA) involvement in form of stenosis or hypoplasia. As TOF is commonly associated with other cardiac structural anomalies, we encountered following associations in our study – aortopulmonary collaterals (37%), Patent ductus arteriosus (29%), right sided aortic arch (19%), bilateral superior vena cava (10%), bovine arch (3%), double aortic arch (2%), d malposition of great vessels (2%), l malposition of great vessels (1%), situs inversus (1%), dextrocardia (1%), annuloaortic ectasia (1%) aortopulmonary window (1%) and cardiac totally anomalous pulmonary venous connection (1%).

Conclusions

Anomalies of pulmonary arteries are important determinant of surgical outcome of TOF patients. CT angiography is now established modality to delineate pulmonary artery and other anatomical details in TOF patient. Pulmonary artery anomaly can range from isolated branch pulmonary stenosis to diffuse hypoplasia of pulmonary vasculature, based on which management can differ from complete correction to palliative or medical management only. Our study emphasize the importance of pulmonary artery evaluation and its variation among patients of TOF.

Abstract P268 Figure.

Accurate calculation of zero point energy from molecular dynamics simulations of liquids and their mixtures

The two-phase thermodynamic (2PT) method is used to compute the zero point energy (ZPE) of several liquids and their mixtures. The 2PT method uses the density of states (DoS), which is computed from the velocity autocorrelation (VAC) function obtained from a short classical molecular dynamics trajectory. By partitioning the VAC and the DoS of a fluid into solid and gaslike components, quantum mechanical corrections to thermodynamical properties can be computed. The ZPE is obtained by combining the partition function of the quantum harmonic oscillator with the vibrational part of the solidlike DoS. The resulting ZPE is found to be in excellent agreement with both experimental and ab initio results. Solvent effects such as hydrogen bonding and polarization can be included by the utilization of ab initio density functional theory based molecular dynamics simulations. It is found that these effects significantly influence the DoS of water molecules. The obtained results demonstrate that the 2PT model is a powerful method for efficient ZPE calculations, in particular, to account for solvent effects and polarization.

A case report of carcinoma of uterine cervix throwing heterochronous metastasis to the skin, spleen, and pancreas: the role of multimodality treatment approach

BACKGROUND

Cancer of cervix often fails locally and/or within the pelvis. One to two percent of cervical squamous cell carcinoma patients have lung metastases at presentation, and 5-35% develop pulmonary metastases later on. Common sites of metastases are the liver, bone, and bowel. We report a rare case presentation of cervical squamous cell cancer where heterochronous metastasis occurred in the skin, spleen, and pancreas without loco-regional recurrence and skipping of visceral organs such as the lung, liver, and brain.

CASE PRESENTATION

A 55-year-old, postmenopausal lady presented with a complaint of bleeding of the vagina for 2 months duration. Cervical biopsy revealed squamous cell carcinoma of the cervix, and she was staged as a case of FIGO stage IIIB. She received external beam-beam radiotherapy of 50 Gy in 25 fractions along with concurrent weekly cisplatin at 35 mg/m² followed by 3 fractions of intracavitary brachytherapy of 6 Gy each. After 30 months of follow-up, she presented with a skin lesion of 6 × 5 cm² in the infrascapular region for 2 months duration. Biopsy revealed metastatic squamous cell carcinoma. Her metastatic work-up revealed no other lesions. Palliative radiotherapy to local site of 8 Gy in single fraction was delivered. The lesion disappeared within 4 weeks. She was given 6 cycles of cisplatin and paclitaxel salvage chemotherapy. After 30 months of follow-up, she presented with a skin lesion of 6 × 5 cm² in the infrascapular region. Biopsy revealed metastatic squamous cell carcinoma. Her metastatic work-up revealed no other lesions. Palliative radiotherapy to the local site was planned, and a dose of 8 Gy in a single fraction was delivered. The lesion disappeared within 4 weeks. She was given 6 cycles of cisplatin and paclitaxel salvage chemotherapy. Six months after the completion of salvage therapy, she reported with the complaints of recurrent bouts of hematemesis and melena. Her CECT scan revealed 2 × 1.5 cm² growth in the body of the pancreas and a subcentric splenic hilum node. She underwent open splenectomy with distal pancreatectomy. Histopathology report showed metastatic infiltration in pancreatic tissue by squamous cell carcinoma and one metastatic node in the splenic hilum. Post-treatment, 6 months, the patient was asymptomatic with no recurrence.

CONCLUSIONS

This is a rare heterochronous metastatic presentation of cervical cancer without loco-regional recurrence and visceral organs such as the lung, liver, and brain. The optimal treatment remains undefined for these patients. Multimodality treatment is necessary to manage the patients.

Physics of suction cups

We have developed a theory of air leakage at interfaces between two elastic solids with application to suction cups in contact with randomly rough surfaces. We present an equation for the airflow in narrow constrictions which interpolates between the diffusive and ballistic (Knudsen) air-flow limits. To test the theory, we performed experiments using two different suction cups, made from soft polyvinylchloride (PVC), in contact with sandblasted polymethylmethacrylate (PMMA) plates. We found that the measured time to detach (lifetime) of the suction cups was in good agreement with theory, except for surfaces with a root-mean-square (rms) roughness below ≈1 μm, where diffusion of plasticizer from the PVC to the PMMA surface caused blockage of critical constrictions. The suction cup volume, stiffness, and elastic modulus have a huge influence on the air leakage and hence the failure time of the cups. Based on our research we propose an improved biomimetic design of suction cups that could show improved failure times with varying degrees of roughness under dry and wet environments.

Rolling friction of elastomers: role of strain softening

We study the temperature and velocity dependency of rolling friction. Steel and PMMA cylinders are rolled on sheets of nitrile butadiene rubber (NBR), with and without filler, and fluoroelastomer (FKM) with filler. Measurements of the rolling friction are performed for temperatures between -40 °C and 20 °C, and for velocities between 5 μm s^-1 and 0.5 cm s^-1. For the unfilled NBR, a smooth rolling friction master curve is obtained using the bulk viscoelastic frequency-temperature shift factor a_T. For the filled rubber compounds, a small deviation from the bulk viscoelastic shift factor is observed at low temperatures. The experimental data are analyzed using an analytical theory of rolling friction. For the filled compounds, good agreement with theory is obtained when strain softening is included, which increases the rolling friction by a factor ∼2 for the filled FKM and ∼3 for the filled NBR compounds. For the unfilled NBR, the maximum of the rolling friction occurs at higher sliding speeds than predicted by the theory. We discuss the role of the adhesive (crack-opening) contribution to the rolling friction, and the role of frozen-in elastic deformations as the rubber is cooled down below the rubber glass transition temperature.

Unusual presentation of chondroblastoma mimicking Trevor's disease

Chondroblastoma is a benign bone tumor, represents 1%–2% of all primary bone tumors, typically seen in patients 10–25-year-old and more common in males. It occurs most frequently in the distal femur, proximal tibia, and proximal humerus. Soft tissue extension is extremely rare. Adjacent joints may develop effusions, but the tumor mass protruding into the joint has never been seen in case of chondroblastoma. We report a rare case of intra-articular chondroblastoma arising from proximal tibia in a 16-year-old boy and growing into the knee joint mimicking an intra-articular osteochondroma.

Vitamins for Cancer Prevention and Treatment: An Insight

Over a few decades a strong interlink between oxidative damage and cancer has been investigated by various scientists across the world on the basis of epidemiological observations of the effects of fruits and vegetables used in the diet for cancer patients. Primarily, Vitamin C, Vitamin D and Vitamin E are reported to be involved in the amelioration of side effects which occur in chemotherapy and radiation therapy of lungs, stomach, prostate, colorectal, gastric head and neck cancers. The vitamins acting as antioxidant adjuvants are found to have apoptotic and antiangiogenesis potential as well as inhibitory effects against metastasis in cancer cells. This chapter explicitly discusses the key aspects concerned with the vitamins in relation to cancer prevention and treatment. It describes vitamins and their natural resources, role of vitamins in the body, and vitamins as prime ingredients in the diet and their effects on cancer biology with reference to recent research reports. Moreover, this paper also includes the emerging potential of pharmaceutical advances to enhance bioavailability of the vitamins to cancer patients with improved safety and efficacy. Clinicians and researchers must mull over the nutritional requirements of individual cancer patient so as to treat cancer and increase life expectancy.

Transition to active learning in rural Nepal: an adaptable and scalable curriculum development model

BACKGROUND

Traditional medical education in much of the world has historically relied on passive learning. Although active learning has been in the medical education literature for decades, its incorporation into practice has been inconsistent. We describe and analyze the implementation of a multidisciplinary continuing medical education curriculum in a rural Nepali district hospital, for which a core objective was an organizational shift towards active learning.

METHODS

The intervention occurred in a district hospital in remote Nepal, staffed primarily by mid-level providers. Before the intervention, education sessions included traditional didactics. We conducted a mixed-methods needs assessment to determine the content and educational strategies for a revised curriculum. Our goal was to develop an effective, relevant, and acceptable curriculum, which could facilitate active learning. As part of the intervention, physicians acted as both learners and teachers by creating and delivering lectures. Presenters used lecture templates to prioritize clarity, relevance, and audience engagement, including discussion questions and clinical cases. Two 6-month curricular cycles were completed during the study period. Daily lecture evaluations assessed ease of understanding, relevance, clinical practice change, and participation. Periodic lecture audits recorded learner talk-time, the proportion of lecture time during which learners were talking, as a surrogate for active learning. Feedback from evaluation and audit results was provided to presenters, and pre- and post-curriculum knowledge assessment exams were conducted.

RESULTS

Lecture audits showed a significant increase in learner talk-time, from 14% at baseline to 30% between months 3-6, maintained at 31% through months 6-12. Lecture evaluations demonstrated satisfaction with the curriculum. Pre- and post-curriculum knowledge assessment scores improved from 50 to 64% (difference 13.3% ± 4.5%, p = 0.006). As an outcome for the measure of organizational change, the curriculum was replicated at an additional clinical site.

CONCLUSION

We demonstrate that active learning can be facilitated by implementing a new educational strategy. Lecture audits proved useful for internal program improvement. The components of the intervention which are transferable to other rural settings include the use of learners as teachers, lecture templates, and provision of immediate feedback. This curricular model could be adapted to similar settings in Nepal, and globally.