Grand Challenges at the Interface of Engineering and Medicine

Over the past two decades Biomedical Engineering has emerged as a major discipline that bridges societal needs of human health care with the development of novel technologies. Every medical institution is now equipped at varying degrees of sophistication with the ability to monitor human health in both non-invasive and invasive modes. The multiple scales at which human physiology can be interrogated provide a profound perspective on health and disease. We are at the nexus of creating "avatars" (herein defined as an extension of "digital twins") of human patho/physiology to serve as paradigms for interrogation and potential intervention. Motivated by the emergence of these new capabilities, the IEEE Engineering in Medicine and Biology Society, the Departments of Biomedical Engineering at Johns Hopkins University and Bioengineering at University of California at San Diego sponsored an interdisciplinary workshop to define the grand challenges that face biomedical engineering and the mechanisms to address these challenges. The Workshop identified five grand challenges with cross-cutting themes and provided a roadmap for new technologies, identified new training needs, and defined the types of interdisciplinary teams needed for addressing these challenges. The themes presented in this paper include: 1) accumedicine through creation of avatars of cells, tissues, organs and whole human; 2) development of smart and responsive devices for human function augmentation; 3) exocortical technologies to understand brain function and treat neuropathologies; 4) the development of approaches to harness the human immune system for health and wellness; and 5) new strategies to engineer genomes and cells.

Multi-phase volcanic resurfacing at Loki Patera on Io

The Jovian moon Io hosts the most powerful persistently active volcano in the Solar System, Loki Patera. The interior of this volcanic, caldera-like feature is composed of a warm, dark floor covering 21,500 square kilometres surrounding a much cooler central 'island'. The temperature gradient seen across areas of the patera indicates a systematic resurfacing process, which has been seen to occur typically every one to three years since the 1980s. Analysis of past data has indicated that the resurfacing progressed around the patera in an anti-clockwise direction at a rate of one to two kilometres per day, and that it is caused either by episodic eruptions that emplace voluminous lava flows or by a cyclically overturning lava lake contained within the patera. However, spacecraft and telescope observations have been unable to map the emission from the entire patera floor at sufficient spatial resolution to establish the physical processes at play. Here we report temperature and lava cooling age maps of the entire patera floor at a spatial sampling of about two kilometres, derived from ground-based interferometric imaging of thermal emission from Loki Patera obtained on 8 March 2015 ut as the limb of Europa occulted Io. Our results indicate that Loki Patera is resurfaced by a multi-phase process in which two waves propagate and converge around the central island. The different velocities and start times of the waves indicate a non-uniformity in the lava gas content and/or crust bulk density across the patera.

Abstract B43: Early detection biomarker of pancreatic cancer using a nanoparticle-based methylation assay

Pancreatic cancer is a deadly cancer with an overall 5-year survival rate of less than 5% and no improvements in survival over the last 3 decades. Pancreatic cancer currently ranks as the fourth leading cause of cancer related death in United States with an estimated 42,470 new cases and 35,240 deaths in 2009 and its incidence is rising.

One of the major factors attributed to the dismal prognosis of pancreas cancer is their delayed diagnosis such that only about 10% cases are amenable to potential curative surgical resection. However, long term 5-year survival is attainable in selected patients with early-stage pancreatic cancer who can undergo curative surgical resection. Early detection of pancreatic cancer is, therefore, thought to be the best modality for improving survival in this lethal disease. However, no screening test currently exists for pancreatic cancer.

In recent years, it has become apparent that pancreatic cancer is as much a disease of mis-regulated epigenetics as it is a disease of genetic mutation. In particular, changes in DNA promoter methylation patterns could play a crucial role in tumorigenesis and cancer progression. In order to address the need for both clinical diagnostics as well as therapeutics, many studies have employed DNA methylation of specific genes for application in diagnostics of multiple cancers. Detection of cancer specific, abnormally DNA methylated gene promoter sequences has emerged as one of the leading tumor, biomarker detection strategies.

We have used a genome-wide transcriptome approach to identify new cancer specific DNA methylation alteration in pancreatic carcinoma. We analyzed methylation frequencies of best candidate genes, BNC1 and ADAMTS1, by MSP and qMSP as well as expression analysis by real-time PCR and immunohistochemistry. We use a novel nanoparticle-enabled MOB (Methylation On Beads) technology to detect very early stages of the pancreatic cancers. The biological role of BNC1 gene was examined by colony formation, cell proliferation, and invasion assays in pancreatic cancer cell lines.

We identified 2 novel genes BNC1 (91.8%) and ADAMTS1 (66.7%) that showed a high frequency of methylation in pancreas cancer tissues (n=143). BNC1 was frequently methylated in the earliest stages of pancreas carcinogenesis including carcinoma in situ or pancreatic intraepithelial neoplasia PanIN3 (100%) and Stage 1 invasive cancers (97.4%). Using the ultrasensitive nanoparticle-enabled MOB assay, these alterations could be detected in serum samples from patients with pancreas cancer, with a sensitivity for BNC1 of 79% (95% CI: 0.6–0.8) and for ADAMTS1 of 48% (95% CI: 0.3–0.6) (n=42 cancers, Stages 1–4), while specificity was 88% for BNC1 (95% CI: 0.6–0.9) and 92% for ADAMTS1 (95% CI: 0.7–0.9) among 26 individuals without cancer. BNC1 overexpresstion in pancreatic cancer cell lines showed suppressive effect by colony formation, cell proliferation but not invasion.

Both BNC1 and ADAMTS1 had high sensitivity for the earliest stages of pancreas cancers. Notably, BNC1 and ADAMTS1 show the potential power of using circulating DNA for early detection of cancer, especially in high risk individuals. Moreover, BNC1 is a candidate tumor suppressor gene in pancreatic cancer which is inactivated by promoter DNA methylation.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B43.

Nanoparticle-enabled highly sensitive detection of DNA methylation in single tube

Background: One of the often occurred epigenetic events associated to cancer is inheritable transcriptional silencing of the tumor suppressor genes by aberrant methylation of cytosines at the promoter regions. Current approaches to detect promoter DNA methylation commonly involve three separate independent processes, including DNA extraction, bisulfite conversion and methylation detection through PCR amplification, such as methylation specific PCR (MSP). This method includes many disconnected steps with loss of genetic materials, potentially reducing the sensitivity required for analysis of challenging clinical samples.

Methods and Results: To address this problem, we developed a new technique named Methylation-on-Beads (MOB). MOB uses the silica superparamagnetic nanobeads (SSB) to combine DNA extraction, bisulfite treatment (Bst) and PCR into a single tube. The single-tube scheme minimizes the DNA loss during the tube transfers and improves the analytical sensitivity for methylation detection. Further enhancement in sensitivity is achieved by combining MOB with quantum dot-enhanced MSP detection.

The pre-PCR DNA yields using MOB were compared with those carried out with conventional organic solvent extraction and ethanol precipitation (PC). 15 serum samples from lung cancer patients (7 Stage I, 3 Stage II, 5 Stage III) were analyzed using both MOB and PC. The DNA recovery using MOB was higher than PC for each patient serum sample with a median increase of 6.61 fold. To demonstrate the versatile applicability of the new method, we further analyzed 10 samples to include fresh tissue and paraffin embedded tissue from normal patients, fresh tumors from cancer patients and sputum samples. Median DNA yield increase of 7.8, 5.3, 6.4 and 7.5 respectively was determined using MOB when compared to the conventional method. We examined the outcome of bisulfite conversion in the presence of SSBs using real-time methylation specific PCR (MSP) to analyze p16INK4a promoter methylation. A set of triplicate reactions were examined with bisulfite-treated DNA of varying treatment durations (0h, 1h, 3h, 4h, 8h), and compared to the control using 16 hrs of conventional bisulfite treatment. Results indicated that 4h of bisulfite treatment was sufficient for conversion, and that the presence of beads did not alter the conversion process.

Assessment of methylation in serum or plasma can be a useful tool for early detection of cancer. However, extending the DNA methylation analysis to clinically usable serum/ blood-based tests has been limited by the lack of sensitivity of conventional methods. In order to address whether improving DNA yields could enhance methylation detection, we compared methylation of p16INK4a promoter in 49 patient serum samples (18 normal and 31 cancer) in a blinded study using both MOB and PC/Bst/MSP. The 31 tumor samples were pre-selected from patients diagnosed with lung cancer who were also methylated for p16INK4a promoter in corresponding tumors. While p16INK4a methylation was detected in 14/31 patients with lung cancer using conventional approach; using MOB, we were able to detect p16INK4a methylation in 23/31of these patients. When samples used for methylation analysis contained large amounts of DNA (cell lines, tumors etc), a single-tube analysis of entire input amount may be unnecessary. Instead, multiple reactions in parallel were feasible by directly splitting the SSB into several different tubes.

Conclusion: MOB successfully combined three processes required for DNA methylation analysis into a single-tube using SSB thereby allowing for ease in handling and increased throughput in detection. Increased pre-PCR yield in MOB allowed for efficient, diagnostically sensitive methylation detection.

DNA methylation analysis on a droplet-in-oil PCR array

We performed on-chip DNA methylation analysis using methylation-specific PCR (MSP) within an arrayed micro droplet-in-oil platform that is designed for more practical application of microfluidic droplet technologies in clinical applications. Unique features of this ready-to-use device include arrayed primers that are pre-deposited into open micro-reaction chambers and use of the oil phase as a companion fluid for both sample actuation and compartmentalization. These technical advantages allow for infusion of minute amounts of sample for arrayed MSP analysis, without the added complexities inherent in microfluidic droplet-based studies. Ease of use of this micro device is exemplified by analysis of two tumor suppressor promoters, p15 and TMS1 using an on-chip methylation assay. These results were consistent with standard MSP protocols, yet the simplicity of the droplet-in-oil microfluidic PCR platform provides an easy and efficient tool for DNA methylation analysis in a large-scale arrayed manner.

Determination of phytoestrogens in dietary supplements by LC-MS/MS

Labelling data quantifying the exact content of individual phytoestrogen analytes in dietary supplements are generally poor. As these products are commonly used in the management of menopause symptoms, any clinical benefits would be dependent on the exact dosage of isoflavones received. Well-established extraction procedures and updated isotope dilution mass spectrometry liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) have been used to accurately quantify the concentrations of ten common isoflavones in 35 dietary supplement samples on sale in the UK, Canada and Italy. Concentration-specific ionization suppression is described for biochanin A and formononetin. All supplements contained phytoestrogens. The soya isoflavones (genistein, daidzein, glycitein) were present in all products and the majority also contained the red clover isoflavones (biochanin A, formononetin) and some the Kudzu isoflavones (daidzein, puerarin). The content of total isoflavones per dose ranged from <1 to 53 mg. Trace amounts of coumestrol were found in six products. Other less common analytes, the prenylnaringenins (6-prenylnaringenin, 8-prenylnaringenin, 6,8-diprenylnaringenin) were not found in any of the products. Only 14 of 35 supplements were found to deliver more than or equal to 40 mg day(-1) of aglycone isoflavones, a consensus dose value recognized as delivering therapeutic benefit. Eleven did not match label claims. Six delivered less than 10 mg day (-1) of isoflavones. There has been little improvement in the overall quality of industry labelling in the five years since this was last investigated. Consequently, the public, retailers and healthcare professionals should consider using standardized isoflavone supplements, which are supported by analytical measurements.

The Strengths and Difficulties Questionnaire: a pilot study on the validity of the self-report version

The self-report version of the Strengths and Difficulties Questionnaire (SDQ) was administered to two samples of 11-16 year olds: 83 young people in the community and 116 young people attending a mental health clinic. The questionnaire discriminated satisfactorily between the two samples. For example, the clinic mean for the total difficulties score was 1.4 standard deviations above the community mean, with clinic cases being over six times more likely to have a score in the abnormal range. The correlations between self-report SDQ scores and teacher--or parent rated SDQ scores--compared favourably with the average cross informant correlations in previous studies of a range of measures. The self-report SDQ appears promising and warrants further evaluation.

Environmental flow requirements in arid zone rivers--a case study from the Lake Eyre Basin, central Australia

The ARIDFLO project takes a multi-disciplinary approach to the collection and analysis of data required to formulate appropriate environmental flow requirements for rivers in the Lake Eyre Basin. The key drivers of the ecological processes underpinning the health of these rivers are identified by modelling whole-of-ecosystem biological responses to hydrological events over a range of spatial and temporal scales. First, the hydrology of these poorly gauged (often ungauged) rivers needs to be modelled and validated to mimic real flow and inundation patterns at the catchment, reach and waterbody scale. Modelled and actual discharge data are then used to provide a suite of hydrological predictor variables which, in conjunction with other environmental variables, are used to model observed biotic responses. The key hydrologic and environmental drivers identified by the statistical models need to be taken into account when determining environmental flow requirements for these river systems. Further work is required to assess the predictive power of the models in the highly variable, complex systems of the Lake Eyre Basin rivers.

HLA-DRB3*0101 is associated with Graves' disease in Jamaicans

OBJECTIVES

Graves' disease is associated with different human leucocyte antigen (HLA) genes in different populations. This studywasdesigned to examinethe HLA class II associations with Graves' disease in Jamaicans.

PATIENTS

One hundred and six Jamaicans with Graves' disease and 104 controls.

DESIGN

Oligotyping for HLA-DRB1, DRB3, DQA1 and DQB1 alleles was performed using the polymerase chain reaction sequence specific oligonucleotide probe (PCR-SSOP) technique. RESULTS The frequency of HLA-DRB3 *0101 was increased significantly in the patients compared to controls (38.7% vs. 19.2%; RR = 2.72; Pc < 0.015). The protective alleles for Graves' disease were DRB1 *0901 (0.9% vs. 20.2%; RR = 0.04; Pc < 0.001), DRB1*1001 (0.0% vs. 11%; RR = 0.0%; Pc < 0.01) and DRB4 *0101 (0.0% vs. 12.5%; RR = 0.0; Pc < 0.05). A high female to male ratio of Graves' disease, 25 :1, was observed. Other associated autoimmune diseases were rare and no significant HLA class II associations were found with clinical markers of disease.

CONCLUSIONS

Jamaican patients with Graves' disease share the DRB3 *0101 susceptible allele and the DRB4 *01 protective allele but not the susceptible haplotype DRB1 *0301, DRB3*0101, DQA1*0501 with Caucasians.

The Strengths and Difficulties Questionnaire: a pilot study on the validity of the self-report version

The self-report version of the Strengths and Difficulties Questionnaire (SDQ) was administered to two samples of 11-16 year olds: 83 young people in the community and 116 young people attending a mental health clinic. The questionnaire discriminated satisfactorily between the two samples. For example, the clinic mean for the total difficulties score was 1.4 standard deviations above the community mean, with clinic cases being over six times more likely to have a score in the abnormal range. The correlations between self-report SDQ scores and teacher- or parent-rated SDQ scores compared favourably with the average cross-informant correlations in previous studies of a range of measures. The self-report SDQ appears promising and warrants further evaluation.

Children's consent to psychiatric treatment: all or nothing?

An adolescent with a history of attempted suicide who refused to involve his father in the treatment plan is presented. Issues surrounding consent to psychiatric treatment in childhood are discussed and the assessment process outlined. Contributions by primary healthcare professionals are emphasised.

Verbal and nonverbal communication of events in learning-disability subtypes

This study compared a group of nondisabled children (ND) with groups of learning-disabled children who were primarily impaired in reading and arithmetic skills (Reading-Arithmetic Disabled; RAD) and arithmetic but not reading (Arithmetic Disabled; AD) on a set of tasks involving comprehension and production of verbally and nonverbally presented events. Children viewed videotaped scenarios presented in verbal (narrative) and nonverbal (puppet actors) formats and were asked to describe or enact with puppets the events depicted in the stories. Rourke (1978, 1982) has shown that RAD children have problems with verbal skills, whereas AD children have problems with nonverbal skills. Consequently, it was hypothesized that children's performance in comprehending and reproducing stories would be related to the type of learning disability. Results showed that RAD children made more errors than AD children with verbal presentations and describe-responses, whereas AD children made more errors than RAD children with nonverbal presentations and enact-responses. In addition, learning disabled children were more likely than controls to misinterpret affect and motivation depicted in the stories. These results show that learning disabled children have problems with social communication skills, but that the nature of these problems varies with the type of learning disability.

Research note: recurrent headaches and stomachaches in preschool children

Data are presented on headaches and stomachaches in a sample of 189 3-year-old children obtained as part of community based study. These data provide a partial replication of an earlier study on a separate sample of children [Zuckerman, B., Stevenson, J. and Bailey, V. (1987). Stomachaches and headaches in a community sample of preschool children. Pediatrics, 79, 677-682]. The results supported the previous findings of a link between family factors and recurrent stomachache, and a less strong association with headaches. The conclusions reinforce the notion that these two somatic symptoms should be considered separately in preschool children.

Sleep problems in early childhood: continuities, predictive factors, and behavioral correlates

A longitudinal study, based on interviews with 308 middle-class, preponderantly white mothers, provided an opportunity to evaluate the continuity, predictive factors, and behavioral correlates of sleep problems in young children. When their children were 8 months old, 10% of the mothers reported that their babies woke three or more times per night, 8% reported that the babies took an hour or more to settle after waking, 5% complained that their own sleep was severely disrupted by the child, and 18% reported at least one of these problems. At 3 years of age, 29% of the children had difficulty getting to bed and/or falling asleep or staying asleep. Of children with a sleep problem at 8 months of age, 41% still had a problem at 3 years of age, whereas only 26% of children without a problem at 8 months of age had a problem at 3 years of age (P less than .001). Among children with sleep problems at 8 months of age, mothers' depressed feelings were the only measured demographic or psychosocial factor associated with persistent sleep problems (P = .02). A separate analysis indicated that these depressed feelings did not appear to be a consequence of the child's sleep problem. Future studies should evaluate how maternal depression interacts with other factors to result in persistent sleep problems. Children with persistent sleep problems were more likely to have behavior problems, especially tantrums (P less than .02) and behavior management problems (P less than .01), than were children without persistent sleep problems (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Stomachaches and headaches in a community sample of preschool children

The epidemiology of recurrent stomachache and headache was studied in a community sample of 308 preschool children, most of whom were white. When the children were 3 years old, interviews with their mothers indicated that 3% had recurrent headaches and 9% had recurrent stomachaches. Children with recurrent stomachaches were more likely than those without recurrent stomachaches to have mothers who were emotionally depressed (P less than .01), had marital problems (P less than .05), and perceived their own health as poor (P less than .05). When maternal poor health was controlled, depression was still associated with their children having stomachaches (P less than .05). Prospectively collected data demonstrate that children with recurrent stomachaches did not have bowel difficulties when they were infants. Other psychosocial stresses and demographic factors were not associated with stomachaches. The only variable associated with recurrent headache was maternal depression. Children with recurrent headaches or stomachaches were more likely to have behavior problems, as measured by the Behavior Screening Questionnaire, than were children without these symptoms. The analysis presents new data on these common symptoms of childhood.

Field replication of classwide peer tutoring

We conducted a large-scale field replication study of classwide peer tutoring applied to spelling instruction (Greenwood, Delquadri, & Hall, 1984). Two hundred and eleven inner-city students in four schools participated during their first- and second-grade school years. The effects of classwide peer tutoring were compared to teacher instructional procedures and pretest probes using a group replication design (Barlow, Hayes, & Nelson, 1984). Analysis of group and individual results indicated that (a) both teacher instructional procedures and classwide peer tutoring were effective in increasing spelling performance above pretest levels, (b) peer tutoring produced statistically greater gains relative to the teachers' procedures for both low and high student groups formed on pretest levels, (c) these outcomes were representative of groups, classes, individuals, and years during the project, and (d) participant satisfaction with the program was generally high. A separate analysis of the social importance of treatment outcome revealed differential findings for low and high groups related to pretest levels. Implications of these findings are discussed.

How much child psychiatry does a general practitioner do?

Eleven general practitioners recorded information on relevant psychological and social factors on 1,127 consecutive attendances of children and adolescents under the age of 18 years. The proportion of 'pure' psychological problems was low (3.5 per cent of all attendances), but in 25.7 per cent of attendances a psychological component to the presenting problem existed. Non-specific 'emotional' problems were the most frequent psychological symptoms noted, but management problems in infancy and early childhood were also common. There were significant differences between practitioners in the proportion of 'purely physical' diagnoses made and in action taken at the time of attendance. The findings suggest that paediatric training of general practitioners should contain a considerable child psychiatric component.