POS1331 LONG-TERM OUTCOME IN CHILDREN WITH JUVENILE DERMATOMYOSITIS FROM SOUTHERN INDIA

Background:

There is paucity of data regarding long-term outcome and cumulative damage in children with juvenile dermatomyositis (JDM) from the Indian subcontinent.

Objectives:

To assess the long-term outcome and cumulative damage in children with JDM receiving treatment at a tertiary hospital in southern India.

Methods:

Retrospective review of records and cross-sectional assessment of outcome and damage in 29 patients with JDM at a tertiary hospital in Kochi, India. The disease course was categorized as monocyclic, polycyclic and chronic progressive. Cumulative damage was assessed using the IMACS myositis damage index (MDI).

Results:

Twenty-nine patients (male-16) diagnosed with definite or probable juvenile dermatomyositis based on the Bohan and Peter criteria and having a minimum follow-up period of 3 years each were enrolled. Of these, 20 children were diagnosed and initiated on treatment at our institute (inceptional) and 9 were diagnosed elsewhere and referred to our centre for further management (non-inceptional). The mean age at disease onset was 7.01 ± 3.34 years (range 1.0 to 13.5 years). The median interval from onset to diagnosis was 3 months (range- 3 weeks to 8.75 years). Delayed diagnosis defined as interval from onset to diagnosis exceeding 6 months was noted in case of 8 children. Among patients in the non-inceptional group, six were considered to have not received standard of care treatment prior to referral to our centre. Standard of care treatment was defined as initiation of a treatment regimen comprising of a combination of glucocorticoids with an immunosuppressive agent within 4 weeks of diagnosis. A total of 11 children had a delayed diagnosis and/or had not received standard of care treatment prior to referral.

At our centre, all patients received oral steroids and subcutaneous methotrexate as standard therapy. Pulse steroids were used to induce remission in 12 patients and as a rescue for relapses in 2 patients. Intravenous immunoglobulin was used in 10 children with severe myositis, oropharyngeal weakness, refractory cutaneous disease including calcinosis and concomitant infection, where affordable with good results. Hydroxychloroquine was added in 15 patients with dominant cutaneous manifestations. Mycophenolate mofetil, azathioprine and tacrolimus were used in patients refractory or intolerant to methotrexate. Cyclophosphamide and rituximab were used in 4 patients each with refractory disease and extra-muscular manifestations such as interstitial lung disease. Seven patients with refractory calcinosis received pamidronate infusions.

The total follow-up duration was 121.06 patient-years. A monocyclic course was observed in 11/29 (37.9%), chronic progressive course in 16/29 (55.2%) and polycyclic course in 2/29(6.9 %). Nearly half of the patients (14/29) had damage in at least one organ using the MDI (MDI ≥1). 38% of the patients (11/29) had at least one sign of cutaneous damage, the most common being calcinosis (n=11) and lipodystrophy (n=4). This was followed by skeletal damage (n=6, joint contractures-5, osteoporosis with fracture-1), muscle and pulmonary (pulmonary fibrosis) damage in 3 patients each, endocrine damage in 2 patients (diabetes mellitus-1, growth failure and delayed development of secondary sexual characteristics-1) and chronic infection in one patient. All patients with damage in at least one organ had a chronic progressive course, indicating damage accrual. Delayed diagnosis and lack of standard of care treatment prior to referral (i.e., longer duration of untreated/ sub-optimally treated disease) were associated with an increased risk of cumulative damage (p< 0.05).

Conclusion:

Nearly half of the patients had damage in at least one organ using the MDI. Cutaneous damage was the most common, followed by skeletal, muscle, pulmonary and endocrine damage. Longer duration of untreated/ sub-optimally treated disease significantly increases the risk of cumulative damage, highlighting the need for an early diagnosis and referral to pediatric rheumatology services.

Disclosure of Interests:

None declared

COPD-associated miR-145-5p is downregulated in early-decline FEV1 trajectories in childhood asthma

BACKGROUND

Many microRNAs (miRNAs) have been associated with asthma and chronic obstructive pulmonary disease (COPD). Longitudinal lung function growth trajectories of children with asthma-normal growth, reduced growth (RG), early decline (ED), and RG with an ED (RGED)-have been observed, with RG and RGED associated with adverse outcomes, including COPD.

OBJECTIVE

Our aim was to determine whether circulating miRNAs from an early age in children with asthma would be prognostic of reduced lung function growth patterns over the next 16 years.

METHODS

We performed small RNA sequencing on sera from 492 children aged 5 to 12 years with mild-to-moderate asthma from the CAMP clinical trial, who were subsequently followed for 12 to 16 years. miRNAs were assessed for differential expression between previously assigned lung function growth patterns.

RESULTS

We had 448 samples and 259 miRNAs for differential analysis. In a comparison of the normal and the most severe group (ie, normal growth compared with RGED), we found 1 strongly dysregulated miRNA, hsa-miR-145-5p (P < 8.01E-05). This miR was downregulated in both ED groups (ie, ED and RGED). We verified that miR-145-5p was strongly associated with airway smooth muscle cell growth in vitro.

CONCLUSION

Our results showed that miR-145-5p is associated with the ED patterns of lung function growth leading to COPD in children with asthma and additionally increases airway smooth muscle cell proliferation. This represents a significant extension of our understanding of the role of miR-145-5p in COPD and suggests that reduced expression of miR-145-5p is a risk factor for ED of long-term lung function.

Should COVID-19 patients >75 years be Ventilated? An Outcome Study

BACKGROUND

Elderly patients with COVID-19 disease are at increased risk for adverse outcomes. Current data regarding disease characteristics and outcomes in this population are limited.

AIM

To delineate the adverse factors associated with outcomes of COVID-19 patients ≥75 years of age.

DESIGN

Retrospective cohort study.

METHODS

Patients were classified into mild/moderate, severe/very severe and critical disease (intubated) based on oxygen requirements. The primary outcome was in-hospital mortality.

RESULTS

A total of 355 patients aged ≥75 years hospitalized with COVID-19 between 19 March and 25 April 2020 were included.Mean age was 84.3 years. One-third of the patients developed critical disease. Mean length of stay was 7.10 days. Vasopressors were required in 27%, with the highest frequency in the critical disease group (74.1%). Overall mortality was 57.2%, with a significant difference between severity groups (mild/moderate disease: 17.4%, severe/very severe disease: 71.3%, critical disease: 94.9%, P < 0.001).Increased age, dementia, and severe/very severe and critical disease groups were independently associated with increased odds for mortality while diarrhea was associated with decreased odds for mortality (OR: 0.12, 95% CI: 0.02-0.60, P < 0.05). None of the cardiovascular comorbidities were significantly associated with mortality.

CONCLUSION

Age and dementia are associated with increased odds for mortality in patients ≥75 years of age hospitalized with COVID-19. Those who require intubation have the greatest odds for mortality. Diarrhea as a presenting symptom was associated with lower odds for mortality.

POS1262 A COHORT STUDY OF COVID-19 RELATED MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN AND ADOLESCENTS FROM MULTIPLE TERTIARY CARE CENTRES IN SOUTH INDIA

Background:

After the peak of COVID 19 pandemic, a surge of cases with multi-system involvement and hyperinflammatory state was reported in children, at multiple tertiary care centers across the world. (1) This COVID-19 associated multisystem inflammatory syndrome in children and adolescents is also known as multisystem inflammatory syndrome in children (MIS-C). There is a paucity of literature of clinical profile of MIS-C patients from India.

Objectives:

To study the clinical manifestations and treatment outcomes of COVID-19 related multisystem inflammatory syndrome in children (MIS-C) and adolescents.

Methods:

It was a cohort study including cases defnied as per the case definitions of MIS-C by World Health Organisation (WHO) or Centre for Disease Control and Prevention(CDC).(2)The clinical parameters, laboratory parameters (including inflammatory markers, D dimer and NT ProBNP), electrocardiogram, 2D echocardiogram, course in hospital, and immediate outcomes were noted.

Results:

Twenty five patients (male-14) with a mean age of 6.22 ±4.25 years and a mean body mass index of 16.21 ±3.36 kg/m2 were enrolled on the study. Average length of hospital stay was 8.12±5.76 days. Associated comorbidities were present in 4 of our patients (16%). Figure 1 shows the frequency of clinical features in our study patients. Table 1 shows the clinical, laboratory, imaging findings, disease course and outcomes.

Figure 1.

Frequency of clinical features in our MIS-C cohort patients

Table 1.

Clinical characteristics of MIS-C patients (n)=25

Clinical Phenotypes:Incomplete/ Atypical Kawasaki Disease (KD)18 (72%)Macrophage activation syndrome (MAS)11 (44%)Unexplained Shock13 (52%)Fever with gastrointestinal symptoms17 (68%)Fever with neurological symptoms9 (36%)Fever with respiratory symptoms5 (20%)COVID chronology:MISC with acute COVID 19 with MAS1 (4%)MISC with acute COVID 19 with incomplete/atypical KD1 (4%)COVID 19 tests:COVID 19 RTPCR positive2 (8%)COVID 19 RTPCR negative23 (92%)COVID 19 IgG positive20 (80%)COVID 19 IgM positive6 (24%)COVID 19 IgG and IgM both positive2 (8%)COVID 19 IgG and IgM not done4 (16%)Other laboratory investigations(Peak/ trough values):Anaemia20 (80%)Leukopenia2 (8%)Thrombocytopenia6 (24%)Pancytopenia2 (8%)Positive CRP23 (92%)High Procalcitonin9 (36%)High ferritin10 (40%)High D- dimer17 (68%)High NT ProBNP23 (92%)Hypoalbuminemia14 (56%)Sterile pyuria7 (28%)Proteinuria4 (16%)Cardiac assessment:Abnormal Electrocardiogram (ECG)5 (20%)Abnormal Echocardiography15 (60%)Coronary dilation/prominence/non-tapering9 (36%)Coronary aneurysm1 (4%)LAD Z score (Mean±SD)2.12 ± 1.11Decreased Ejection fraction (EF)5 (20%)Systolic Dysfunction5 (20%)Pericardial effusion9 (36%)Global/septal hypokinesia4 (16%)Mitral Valve regurgitation3 (12%)Complete heart block1 (4%)

Twenty patients (80%) had severe illness requiring intensive care. Fourteen patients (56%) required inotropic support, 8 patients (32%) required supplemental oxygen, 5 patients (20%) required mechanical ventilation and 2 patients (8%) expired. A total of 23 patients (92%) received pulse steroids followed by oral/iv steroids, 22 patients (88%) received IVIG (2g/kg) and 3 patients (12%) required anticoagulation.

Conclusion:

Our MIS-C cohort had varied clinical manifestations ranging from the mild cutaneous and gastrointestinal symptoms to fatal multiorgan dysfunctions. In contrast to western cohorts, our study cohort had higher number of patients from younger age group and lower BMI.

References:

[1]Ahmed M, Advani S, Moreira A, Zoretic S, Martinez J, Chorath K et al. Multisystem inflammatory syndrome in children: A systematic review. EClinicalMedicine. 2020;26:100527.

[2]Jiang L, Tang K, Levin M, Irfan O, Morris S, Wilson K et al. COVID-19 and multisystem inflammatory syndrome in children and adolescents. The Lancet Infectious Diseases. 2020;20(11):e276-e288.

Disclosure of Interests:

None declared

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.

Circulating MicroRNA: Incident Asthma Prediction and Vitamin D Effect Modification

Of children with recurrent wheezing in early childhood, approximately half go on to develop asthma. MicroRNAs have been described as excellent non-invasive biomarkers due to their prognostic utility. We hypothesized that circulating microRNAs can predict incident asthma and that that prediction might be modified by vitamin D. We selected 75 participants with recurrent wheezing at 3 years old from the Vitamin D Antenatal Asthma Reduction Trial (VDAART). Plasma samples were collected at age 3 and sequenced for small RNA-Seq. The read counts were normalized and filtered by depth and coverage. Logistic regression was employed to associate miRNAs at age 3 with asthma status at age 5. While the overall effect of miRNA on asthma occurrence was weak, we identified 38 miRNAs with a significant interaction effect with vitamin D and 32 miRNAs with a significant main effect in the high vitamin D treatment group in VDAART. We validated the VDAART results in Project Viva for both the main effect and interaction effect. Meta-analysis was performed on both cohorts to obtain the combined effect and a logistic regression model was used to predict incident asthma at age 7 in Project Viva. Of the 23 overlapped miRNAs in the stratified and interaction analysis above, 9 miRNAs were replicated in Project Viva with strong effect size and remained in the meta-analysis of the two populations. The target genes of the 9 miRNAs were enriched for asthma-related Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. Using logistic regression, microRNA hsa-miR-574-5p had a good prognostic ability for incident asthma prognosis with an area under the receiver operating characteristic (AUROC) of 0.83. In conclusion, miRNAs appear to be good biomarkers of incident asthma, but only when vitamin D level is considered.

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.

CASTER: Cross-Sectional Asthma STEroid Response Measurement

Asthma patient response to inhaled corticosteroids (ICS) is variable and difficult to quantify. We aimed to define a measure of steroid response suitable for pharmacogenetic research in longitudinal and cross-sectional cohorts. Using longitudinal data from the Childhood Asthma Management Program (CAMP) asthma cohort, we defined the Cross-sectional Asthma STEroid Response (CASTER) measure in cross-sectional data. We then applied this to cross-sectional slices of four independent asthma cohorts: The Improving Asthma Control Trial (IMPACT), the Salmeterol or Corticosteroids Study (SOCS), the Pediatric Asthma Controller Trial (PACT), and the Genetics of Asthma in Costa Rica Study (GACRS). CASTER achieved high accuracy on the childhood asthma cohorts: GACRS, PACT, and also on cross-sectional data from CAMP (AUCs 82%, 71%, 63%, respectively). This demonstrates that select cross-sectional clinical information is sufficient to identify good and poor responders to ICS treatment in childhood asthma. Thus, CASTER represents a major improvement in the usability and applicability of steroid response measures in asthma research.

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.