A multiscale orchestrated computational framework to reveal emergent phenomena in neuroblastoma

Neuroblastoma is a complex and aggressive type of cancer that affects children. Current treatments involve a combination of surgery, chemotherapy, radiotherapy, and stem cell transplantation. However, treatment outcomes vary due to the heterogeneous nature of the disease. Computational models have been used to analyse data, simulate biological processes, and predict disease progression and treatment outcomes. While continuum cancer models capture the overall behaviour of tumours, and agent-based models represent the complex behaviour of individual cells, multiscale models represent interactions at different organisational levels, providing a more comprehensive understanding of the system. In 2018, the PRIMAGE consortium was formed to build a cloud-based decision support system for neuroblastoma, including a multi-scale model for patient-specific simulations of disease progression. In this work we have developed this multi-scale model that includes data such as patient's tumour geometry, cellularity, vascularization, genetics and type of chemotherapy treatment, and integrated it into an online platform that runs the simulations on a high-performance computation cluster using Onedata and Kubernetes technologies. This infrastructure will allow clinicians to optimise treatment regimens and reduce the number of costly and time-consuming clinical trials. This manuscript outlines the challenging framework's model architecture, data workflow, hypothesis, and resources employed in its development.

Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[(18)F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([(11)C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m(-2)·min(-1)) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption (P = 0.04) and perfusion (P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids (P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions (P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups (P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM (P = 0.003). Myocardial work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM.

Relating centromeric topography in fixed human chromosomes to α-satellite DNA and CENP-B distribution

Despite extensive analyses on the centromere and its associated proteins, detailed studies of centromeric DNA structure have provided limited information about its topography in condensed chromatin. We have developed a method with correlative fluorescence light microscopy and atomic force microscopy that investigates the physical and structural organization of α-satellite DNA sequences in the context of its associated protein, CENP-B, on human metaphase chromosome topography. Comparison of centromeric DNA and protein distribution patterns in fixed homologous chromosomes indicates that CENP-B and α-satellite DNA are distributed distinctly from one another and relative to observed centromeric ridge topography. Our approach facilitates correlated studies of multiple chromatin components comprising higher-order structures of human metaphase chromosomes.

Contributions of dysglycaemia, obesity, and insulin resistance to impaired endothelium-dependent vasodilation in humans

BACKGROUND

Individual effects of hyperglycaemia and obesity to impair vascular health are recognized. However, the relative contributions of dysglycaemia versus other obesity-related traits to vascular dysfunction have not been systematically evaluated.

METHODS

We undertook a cross-sectional evaluation of factors contributing to vascular function in 271 consecutive subjects, categorized as non-obese normal glucose tolerant (n = 115), non-obese dysglycaemic (n = 32), obese normal glucose tolerant (n = 57), obese dysglycaemic (n = 38), or type 2 diabetic (n = 29). Vascular function was measured invasively as leg blood flow responses to methacholine chloride, an endothelium-dependent vasodilator. Categorical and continuous analyses were carried out to assess the contributions of hyperglycaemia to vascular dysfunction.

RESULTS

Even among normoglycaemic subjects, obese subjects had impaired vascular function compared to non-obese subjects (p = 0.004). Vascular function was also impaired in non-obese dysglycaemic subjects (p = 0.04 versus non-obese normoglycaemic subjects), to a level comparable to normoglycaemic obese subjects. Within obese subject groups, gradations of dysglycaemia including the presence of diabetes were not associated with further worsening of these vascular responses beyond the effect of obesity alone (p = not significant comparing all obese groups, p < 0.001 versus lean normoglycaemic subjects). After univariate and multivariable modelling analyses we found that effects of glycaemia were less powerful than effects of insulin resistance and obesity on vascular dysfunction.

CONCLUSIONS

Dysglycaemia contributes to impaired vascular function in non-obese subjects, but obesity and insulin resistance are more important determinants of vascular function in obese and diabetic subjects.

The Gene Ontology (GO) database and informatics resource

The Gene Ontology (GO) project (http://www. geneontology.org/) provides structured, controlled vocabularies and classifications that cover several domains of molecular and cellular biology and are freely available for community use in the annotation of genes, gene products and sequences. Many model organism databases and genome annotation groups use the GO and contribute their annotation sets to the GO resource. The GO database integrates the vocabularies and contributed annotations and provides full access to this information in several formats. Members of the GO Consortium continually work collectively, involving outside experts as needed, to expand and update the GO vocabularies. The GO Web resource also provides access to extensive documentation about the GO project and links to applications that use GO data for functional analyses.

Percutaneous mitral valve dilatation with the Multi-Track System

We developed the Multi-Track System for percutaneous mitral valvotomy and described the preliminary results in 1995. Here we report the first 100 consecutive cases after the original publication. Two separate balloon catheters are positioned on a single guidewire. The first catheter, with only a distal guidewire lumen, is introduced into the vein and then advanced into the mitral orifice. Subsequently, a rapid exchange balloon catheter running on the same guidewire is inserted and lined up with the first catheter so the two are positioned side by side. Both balloons are then inflated simultaneously. Age of the patients was 31 +/- 12.8 years and weight 50 +/- 14 kg. Valve area increased 0.75 +/- 0.22 cm(2) to 2.00 +/- 0.32 cm(2)and mean left atrial pressure dropped from 27 +/- 8 to 11 +/- 5 mm Hg. One patient had significant mitral insufficiency after dilatation, which did not require surgery. The Multi-Track System is a valid alternative to the existing procedures for the treatment of mitral stenosis and uses simpler and less costly catheters. Cathet. Cardiovasc. Intervent. 48:178-183, 1999.

Cancer incidence rate and mortality rate in sickle cell disease patients at Howard University Hospital: 1986-1995

The incidence of cancer in patients with sickle cell disease (SCD) is not known. The 10-year follow-up data on 696 patients with SCD was analyzed at our institution in order to determine the cancer incidence and cancer mortality rates. The age range was 18 to 79 years, with a mean age of 28.8 years. There were 377 females and 319 males. The median follow-up was 3 years. Five patients developed cancer during this period. The cancer incidence rate was 5/2,864 or 1.74 per 1,000 patient years. The 95% CI was 0.64 to 4.32 per 1,000 patient years. There were 68 deaths with 3 being due to cancer. The cancer mortality rate was 3/2,873 or 1.04 cases per 1,000 patient years. Our data represent the first published paper that the authors are aware of, where the cancer incidence and mortality rates have been calculated for any group of patients with SCD.

Effect of intracoronary saline infusion on dissection during excimer laser coronary angioplasty: a randomized trial. The Percutaneous Excimer Laser Coronary Angioplasty (PELCA) Investigators

OBJECTIVES

We sought to evaluate whether intracoronary saline infusion during excimer laser coronary angioplasty decreases the incidence of significant laser-induced coronary artery dissections.

BACKGROUND

Despite procedural success rates > 90%, coronary artery dissections occur in 17% to 27% of excimer laser coronary angioplasty procedures. Excimer laser irradiation of blood results in vapor bubble formation and acoustomechanical trauma to the vessel wall. Saline infusion into a coronary artery may minimize blood irradiation and consequent arterial wall damage.

METHODS

In this prospective, randomized, controlled study, consecutive patients undergoing excimer laser coronary angioplasty were randomly assigned to conventional laser irradiation in a blood medium or to laser irradiation with blood displacement by intracoronary saline infusion. In the patients randomized to intracoronary saline infusion, prewarmed normal saline was injected through the coronary artery guide catheter at a rate of 1 to 2 ml/s using a power injector. The incidence and severity of dissection after excimer laser ablation were evaluated in a core laboratory by angiographers with no knowledge of treatment assignment. The severity of coronary artery dissection was rated on an ordinal scale of 1 to 5. Dissections of grade 2 or higher were considered significant.

RESULTS

The mean (+/- SE) dissection grade after laser angioplasty in patients treated with intracoronary saline infusion was 0.43 +/- 0.13 compared with 0.91 +/- 0.26 in patients undergoing laser angioplasty in a blood medium. The incidence of significant dissection was 7% in saline-treated patients compared with 24% in conventionally treated patients (p < 0.05). No significant complications were associated with saline infusion.

CONCLUSIONS

Intracoronary saline infusion should be incorporated into all excimer laser coronary angioplasty procedures.

Dysphagia due to secondary achalasia as an early manifestation of squamous cell carcinoma

A 59-year-old man, a smoker, presented with features of airflow obstruction due to squamous cell carcinoma of central airways mimicking chronic obstructive airways disease. He also had pronounced dysphagia. Computed tomographic and magnetic resonance imaging scans showed mediastinal tumour invasion but no direct oesophageal involvement. Oesophageal manometry studies revealed that dysphagia was due to the oesophageal motility disorder, secondary achalasia.

Mechanisms and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty. North American Inoue Balloon Investigators

OBJECTIVES

The purpose of this study was to assess the incidence, mechanism and outcome of severe mitral regurgitation after treatment of mitral stenosis with percutaneous mitral valvuloplasty using the Inoue balloon.

BACKGROUND

Severe mitral regurgitation occurs in up to 15% of percutaneous balloon valvuloplasty procedures for acquired mitral stenosis. The incidence and mechanism of production of mitral regurgitation with the recently introduced single-balloon Inoue technique have not been characterized.

METHODS

We examined the incidence, mechanism, predictors and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty in 280 patients in the North American multicenter registry. Twenty-one patients who developed either clinically significant or angiographically severe regurgitation were identified, and their echocardiograms were reviewed to determine the mechanism of regurgitation. These patients were then compared with the remaining patients without severe regurgitation to identify predictors of this outcome.

RESULTS

The incidence of severe regurgitation in this study was 7.5%, and the mean grade of angiographic regurgitation in these patients increased from 0.9 +/- 1.0 to 2.8 +/- 0.7 (p < 0.05). The most common cause of regurgitation (43%) was rupture of chordae tendineae to the anterior or posterior mitral leaflet. Tearing of a leaflet (usually the posterior one) occurred in 30% of patients; and no recognizable structural abnormality, with wide splitting of the commissures and a central regurgitant jet, was present in five patients (26%). All patients with definite posterior leaflet tears had heavily calcified leaflets. Patients who developed severe regurgitation had fewer balloon inflations and a higher grade of preexisting mitral regurgitation but were otherwise similar to the remaining patients without severe regurgitation. During 6-month follow-up, 71% of the patients with severe regurgitation were treated surgically; the grade of regurgitation decreased in four patients (19%), and five patients (24%) have not required mitral valve replacement during 18 +/- 5 months of follow-up.

CONCLUSIONS

Severe mitral regurgitation is a relatively infrequent complication of Inoue balloon valvuloplasty and results from disruption of the valve integrity, including chordal rupture and leaflet tearing. Careful balloon positioning may help avoid chordal rupture, and heavily calcified posterior leaflets may be at greater risk of tearing. Most patients who develop severe regurgitation will require nonemergency mitral valve replacement.

Ultrasound features of low power interstitial laser hyperthermia

Low power interstitial laser hyperthermia (ILH) is a reliable means of producing in situ thermal necrosis. Ultrasonic studies have been carried out of the changes that occur in canine liver during ILH performed at laparotomy. With a single fibre delivering Nd-YAG laser at 1-1.5 W for 670 s an hyperechoic region developed at the fibre tip measuring 5-6 mm in diameter; around this developed an area of hypoechoic change (up to 500s) giving a total area of changed echogenicity of 14-16 mm. With a multiple fibre system using 4 laser fibres simultaneously the sonographic changes were a summation of the changes seen with a single fibre, the hypoechoic areas overlapping. With this four fibre system the creation of large (3.5 x 2.8 cm) areas of thermal necrosis was possible. There was good correlation between the sonographic and pathological measurements of the region of thermal change. The sonographic studies showed the extension and overlap of regions of thermal necrosis and allowed visualization and accurate measurement of the area undergoing change. The same combined technique has been successfully applied in a small number of clinical cases and may be of use in the treatment of tumours in solid organs.

Aneurysm or occlusive disease--factors determining the clinical course of atherosclerosis of the infrarenal aorta

Atherosclerosis of the infrarenal aorta results in distinct clinical entities--aortoiliac occlusive disease (AOD) and abdominal aortic aneurysm (AAA). Although loss of collagen has been implicated in AAA, collagen accumulation plays a role in AOD. In vivo collagen-gene expression can be assessed using complementary DNA for collagen types I and III alpha-chains. The purpose of this study is to compare total collagen (type I + III) and collagen types I and III messenger RNA in AAA, AOD and normal aorta. Specimens were collected from the infrarenal aorta during operation for AOD (n = 7), AAA (n = 7), autopsy, or organ procurement (normal; n = 7). Northern transfer analysis of total RNA was used to compare mRNA levels for type I and III collagen. After preliminary extraction, specimens were hydrolyzed for hydroxyproline analysis used to calculate total collagen (type I + III). Relative levels of type I (pro-a1[1]) mRNA were greater in both AOD (0.77 +/- 0.35) and AAA tissue (0.94 +/- 0.24; p = 0.6) than in normal aorta (0.02 +/- 0.03). Type III (pro-a1[III]) mRNA levels were also greater in AOD (2.52 +/- 0.19; p = 0.09) and AAA tissue (3.15 +/- 1.3) than in normals (0.97 +/- 0.47). Total collagen concentration was increased in AOD (45.6% +/- 3.1% dry weight; p less than 0.05) but not AAA tissue (27.8% +/- 4%) when compared to normal aorta (34.7% +/- 2.3%). Collagen type I and III gene expression is greater in older, diseased aorta, yet collagen accumulated only in AOD. This implies a similar synthetic response in both AOD and AAA. Thus, proteolytic degradation in AAA appears to determine collagen content and possibly the clinical course of the atherosclerotic process.

Assessment of a single lumbar spine radiograph in low back pain

The lumbosacral spine radiographs of 200 patients with unexplained low back pain and without neurological signs were reviewed. The purpose of the study was to determine whether significant diagnostic information would be lost by replacing the standard three film series with a single radiograph, either in the lateral or antero-posterior projection. The contribution of the coned lumbosacral junction view was also assessed. The results show that a single lateral radiograph is diagnostically satisfactory and would have the added advantages of reducing patient radiation dose and radiographic workload.

A clinical comparison of atracurium and vecuronium in women undergoing laparoscopy

In a double-blind, prospective, randomised trial in 30 women undergoing laparoscopy, atracurium and vecuronium were compared in equipotent (2 X ED95) doses. In the atracurium group, first twitch depression was significantly greater at one minute, and degree of fade significantly greater at one and two minutes, but thereafter neuromuscular monitoring showed no significant difference between the groups. Clinically there was no significant difference between the drugs. Mild intraoperative hypotension was equally common in both groups as was sinus bradycardia. Reversal and recovery were comparable in the two groups. Neostigmine was required in all patients and in three (one atracurium, two vecuronium) a second dose was required in all patients and in three (one atracurium, two vecuronium) a second dose was administered on clinical grounds. Antagonism of the neuromuscular block is required with surgery of this duration despite the intermediate duration of action of the relaxant drugs.

Intrahepatic bile duct dilatation shown by computed tomography--predilection for the left lobe?

Dilated biliary duct radicles were most obvious within the left lobe of the liver in 30 out of 42 patients with obstructive jaundice in whom intrahepatic duct dilatation was satisfactorily demonstrated by computed tomography. In 19 of these 30 patients the level of obstruction was at the lower end of the common bile duct. Recognition of this finding may prevent the erroneous diagnosis of intrahepatic or multiple obstructing lesions.