Image analysis of the human eye has provided new insight into ocular disorders and has the potential to assist in their automated diagnosis. We herein report results from analysis of the processed fundus (retina) images from a) healthy subjects and patients diagnosed with b) diabetic retinopathy or c) glaucoma, by means of image fractal analysis and image invariant moments, and linear discriminant analysis (LDA) for classification. Using the fractal dimension and Hu's invariant moments, LDA achieved classification accuracy of 99.2% for the three conditions.
Raman Spectroscopy provides a non-invasive approach to study cells and tissues, and its ability to provide biochemical composition information of samples shows great importance for the research, diagnosis and treatment of cancer. However, conventional Raman Spectroscopy suffers from weak signal strength observed in many biological samples. Surface-Enhanced Resonance Raman Spectroscopy (SERRS) can overcome this disadvantage with the presence of roughened nano-dimensional noble-metal surfaces. In order to study the role of integrins in breast cancer invasiveness, gold nanostars were conjugated with cyclo-RGDf/k peptide for targeting integrins on breast cancer cells and high-speed Raman mapping was employed to assess the samples. Due to the high dimensionality of the datasets collected through SERRS, we have proposed a semisupervised framework combining feature selection and classification techniques for nanostars detection and tested our method on a breast cancer cells. The results show the advantage of our framework over other data mining technique and potentially provide a new method for evaluating the role of integrins in tumor development. Also, the features selected can possibly be used for further studies on compositional changes observed during the process of breast cancer progression and metastasis.
We assessed the regional variations in density and shear strength within the human thoracic vertebral body using donated cadaveric tissues. Shear strength was significantly lower in the anterior than in the lateral region. From the inferior to the superior endplates, shear strength and maximum load to failure decreased by 23% and 33%, respectively. Trabecular bone maximum load carrying capacity was 5 times higher in the lateral and 4.5 times higher in the central than in the anterior regions. Mechanical strength positively correlated with ash density and most closely with material density.
Accumulation of beta amyloid peptide, including Aβ1-42, is a hallmark of Alzheimer's disease (AD). In the early stages of AD, neuronal death is observed in the septum and the hippocampus of the brain. This neuronal death causes memory and cognitive dysfunction which are clinical manifestations of AD. A newly-discovered neurotransmitter receptor subtype, the α7β2 nicotinic acetylcholine receptor (α7β2-nAChR) is expressed in the septum and the hippocampus of the rodent and human brain. This pentameric receptor has similar functional characteristics to α7-nAChR, a more prevalent subtype. It has been shown that α7-nAChRs mediate internalization of Aβ1-42. Others have shown that Aβ1-42 internalization may cause neuronal dysfunction and death. The aims of the present study are to determine if α7β2-nAChR mediates internalization of Aβ1-42, if this is toxic to the cells, and if it affects intracellular calcium activity. We have used multiphoton microscopy to show internalization of the peptide in SH-EP1 cells expressing α7β2-nAChR and α7-nAChR, and live/dead assays for measuring cell death. Epi-fluorescence microscopy and calcium dyes are being used to compare calcium activity of cells expressing these receptors. These are preliminary steps toward determining the pathogenic molecular mechanisms of neuronal dysfunction and cell death in early stages of AD.
Rickettsial diseases (RD) are widely distributed in the world and account for seasonal outbreaks and epidemics. The greatest challenge to clinicians is diagnosing RD at early phases when antibiotic therapy is most effective. This burgeoning problem is further compounded by the unavailability of rapid point-of-care (POC) diagnostics for RD. The focus of this poster will be development and optimization of dielectrophoresis-enhanced microfluidic impedance biosensing (DEP-e-MIB) assay to detect the pathogenic cells in sera. In DEP-e-MIB assays, pathogens are labeled with a DEP label (polystyrene beads) and then injected into the DEP-e-MIB chip for capture of the labeled pathogens and reading impedance changes at the interdigitated electrodes. We have seen detection down to 10^5 cells. However, minor reduction in nonspecific binding can lead to large increment in signal to noise ratio. Specifically, we show how to reduce in the non-specific binding of immunobeads to the electrodes through the choice of bead surface chemistry (epoxy, carboxylate, and aldehyde), and the co-immobilization of polyethylene glycol with antibodies at the electrodes and the beads. Further we also show how this non-specific binding is affected by the use of DEP.
A novel measure for analysis of multivariate signals in the time-frequency-space domain, the normalized Gabor entropy (NGE), is introduced and applied to multichannel intracranial EEG (iEEG) recordings hours prior to seizures onset in two patients with focal epilepsy. NGE profiles showed a statistically significant progressive decrease of NGE values at epileptogenic focus-related channels as time for seizures occurrence approached. This result implies the progressive appearance of dominant Gabor atoms in the EEG tens of minutes prior to seizures, the detection and monitoring of which could further assist with improvement of the performance of seizure prediction algorithms.
Technology has solutions to almost every health problem and if it doesn't have one yet, it will. We are fast approaching the possibility of replacing every part of our body including parts of our brain. Ground breaking technology is helping the blind to see with an interface between artificial vision systems and the retina. We may even be able to alter our personality. We are looking at the possibility of correcting disease states at the genetic level. Eventually, we will not only have the ability to conquer deficits and illness but we will be able to transform ourselves genetically to improve capacity intellectually and physically, thus changing the trajectory of our evolution. We may even be able to extend human life indefinitely. Bioengineers along with society are at a crossroads of possibilities, some of which are exciting and some of which may even be dangerous. How will limits on undesirable technology be imposed in a world that fails to unite around climate change or weapons of mass destruction? As bioengineers get appropriate training in ethics, they will be better prepared to address the ethical challenges that they might face during their professional life. In the end, it's our values, principles, and beliefs that make us human.
Applications of Medical imaging in clinical diagnostics and image-guided surgery have been increasing at rapid rates. This contributes greater demand for BME graduates including the ones at undergraduate level. It appears medical imaging is not taught at the undergraduate level at many BME programs, thus triggering the need to consider developing an appropriate undergraduate medical imaging and optics course. Teaching undergraduate level medical imaging and optics is more challenging compared to the one at the graduate level due to unavailability of proper level textbooks, lab modules and equipment accessibility. This paper features the theoretical segments taught in such a course and highlights the pedagogy and techniques used to teach a medical imaging and optics course in undergraduate BME programs, as well as the interesting projects and other course requirements associated with it.
Paper microfluidics is an emerging technology that offers a simple and inexpensive alternative to traditional microfluidics. Paper is an attractive medium for microfluidic devices because of its inherent hydrophilicity and low cost. Hydrophobic materials including wax and photoresist are used to pattern the paper. The most common method for making paper microfluidic analytical devices (μPAD) is wax printing, however, this method requires an expensive and specialized printer that is limited to printing documents and channel designs. Our method uses inexpensive materials and tools accessible to most research labs in the US. We utilize 3D printers, a common tool available in many universities because of their versatility. Poly(dimethylsiloxane) (PDMS) wax stamps are used to deposit wax onto paper, forming microfluidic channels. The PDMS stamps are produced with ABS 3D printed molds designed in CAD software. A PDMS stamp is dipped into melted wax and then pressed onto paper much like the process of using a rubber stamp and ink. Once the wax is deposited, the paper is heated, letting the wax penetrate the paper and form hydrophilic channels. This rapid and simple procedure allows researchers to easily produce μPADs with the flexibility of CAD software and 3D printers.
During the past decade the mortality and morbidity due to pulmonary diseases ranked number 2 or 3, the current data projection suggests that COPD (Chronic Obstructive Pulmonary Disease) alone will be the third cause of death worldwide by 2020. Before a respiratory disorder can be treated, it has to be diagnosed. Currently a variety of respiratory diagnostic devices/systems exists. Spirometer is the most common and frequently used respiratory diagnostic device, whereas plethysmograph (Bodybox) and Impulse Oscillometer (IOS) are more sophisticated systems. We have developed a simple, portable, and inexpensive respiratory diagnostic device, Airflow Perturbation Device (APD), that can evaluate the respiratory resistance noninvasively and effortlessly. It is based on normal breathing with no effort from the subject beyond simple breathing into the APD for less than one minute. APD measures the respiratory pressure (in mmHg) and flow (Liter per second), the ratio of the respiratory pressure over respiratory flow is the resistance of the respiratory system (mmHg/L/s). APD has been favorably compared with spirometer, plethysmograph, and IOS. The respiratory resistance value is highly age dependent, it is fairly high for children and infants (60 - 3 mmHg/L/s) and assumes low values in adulthood (2.5-2 mmHg/L/s). We have evaluated the respiratory resistance values for over 3,000 normal subjects and those with a variety of pulmonary disorders such as asthma, COPD, Vocal Fold Dysfunction, etc. Since APD is an effortless and noninvasive pulmonary diagnostic device, it is in particular very attractive for young children and infants unable to do spirometry.
Deep brain stimulation (DBS) surgery involves placing an electrode in the subthalamic nucleus to suppress the motor symptoms, such as tremor, of patients with Parkinson's disease (PD). Currently physicians use the standard Unified Parkinson's Disease Rating Scale (UPDRS) to describe the tremor intraoperatively and post operatively. This scale involves subjective anchor-based observations by the clinical expert.In this study, a wireless accelerometer system is presented that was built from off the shelf components to objectively quantify tremor scores. The system consists of a Teensy 3.1 microcontroller and two 3-axis accelerometers. It wirelessly transmits the readings through a Bluetooth module. The data is received by a custom C++ program that parses and transmits the data.The system is used to record data from patients with PD during and after DBS surgery. We show example data recorded from several PD patients and study the correlation of sensor readings with the DBS ON and OFF states. We provide initial data showing that such a system can be effectively used in the clinic for the objective quantification of motor symptoms of PD patients.
Summary form only given. Anterior cervical discectomy and fusion (ACDF) is commonly performed with cancellous screws placed a 30o convergence. However, there is no consensus on the relationship between regional variation in vertebral body bone mineral density (BMD) and screw orientation for optimal stability and fusion. Twelve cervical (C6 and C7) and thoracic (T6 and T7) vertebrae were harvested from two fresh human cadavers (40- year-old male and 32-year-old female). BMD was measured using dual energy x-ray absorptiometry (DEXA), computerized tomography (CT), and Faxitron X-ray. Each vertebra was casted in epoxy resin and two self-tapping (4.2 mm diameter) cancellous screws of the same length were implanted for side-by-side comparison. One screw was placed at 30o convergence and another at 10o divergence. The screw length was measured to be 85% of the vertebral antero-posterior diameter. The insertion torque was measured using a torque dynamometer. The specimens were then mounted on a mechanical testing machine (Instron) for pullout testing. The central region of the cervical vertebrae was 14% less dense than the lateral region. Cervical convergent screws mean insertion torque, pullout strength, and stiffness were 58 N.cm, 1094 N, and 654 N/mm, respectively. Cervical divergent screws showed an increase in torque (32%), pullout strength (2%), and stiffness (10%). However, the center was denser and mechanically stronger than the periphery at the thoracic level. These preliminary data showed regional variations in biomechanical properties within the vertebral bodies of young adults. The lateral region of the cervical vertebrae was denser and stronger than the central one.
This study investigates conventional delivery of thymoquinone (TQ) and epigallocatechin -3 -gallate (EGCG) when applied to Caov-3 and SK-OV-3 ovarian like cell lines. Culturing the cells and assessment of functional activities were conducted following standard lab protocols. The results revealed: (1) an increase in the SK-OV-3 cell protein levels following treatment with TQ+EGCG which was statistically different (p<0.05) at 24 and 48 hours; (2) nitric oxide levels were statistically different (p<0.05) following the administration of EGCG and TQ+EGCG at 24 and 48 hours for Caov-3 and TQ at 72 hours for SK-OV-3; and (3) glutathione levels were statistically different (p<0.05) following the administration of TQ and EGCG to the SK-OV-3 cell line at 72 hours. Overall conclusion of this study demonstrates that exposure of potent herbal based anti-oxidant extracts may potentially interfere with the functional and mitotic activity of ovarian cancer cells.
Motor imagery and motor movement are two distinct tasks with underlying similar neurological mechanisms. We sought to identify the electroencephalographic (EEG) differences between real and imaginary hand movements. Phase Locking Value (PLV) was employed to estimate brain's connectivity and create a network that was then studied on the basis of brain region centrality. We observed that the frontal/prefrontal cortex exhibits higher centrality in the ? band during motor movement than motor imagery tasks. Additionally, difference between left and right hand tasks was observed in the µ band at the somatosensory association cortex post-tasks' completion. These preliminary results indicate that, by proper EEG analysis, it may be possible to distinguish between motor imagery and motor movement.
Summary form only given. Mediterranean diet (MD) is considered one of the most health promoting diets adopted initially by the Mediterranean population. Recent studies showed a link between MD and lowering the incidence of mild cognitive impairment and Alzheimer's disease (AD). Clinical and preclinical studies have suggested several health promoting effects for the dietary consumption of extra-virgin olive oil (EVOO), a major component of MD, that could protect and decrease the risk of developing AD. Moreover, recent studies have linked this protective effect to oleocanthal, a phenolic secoiridoid component of EVOO. Here we provide evidence to support the role of EVOO and oleocanthal in enhancing the clearance of amyloid-beta (Aβ), a major pathological hallmark in AD, and reducing the overall inflammatory burden on the brain. In our study, both EVOO and oleocanthal treatment significantly decreased Aβ load in the hippocampal parenchyma and microvessels. Furthermore, our mechanistic studies demonstrated an effect on increasing the expression of important amyloid clearance proteins at the blood-brain barrier (BBB) including P-glycoprotein (P-gp) and low density lipoprotein receptor-related protein 1 (LRP1), and to activate the ApoE-dependent amyloid clearance pathway in the mice brains. Additionally, oleocanthal was able to reduce astrocytes activation and IL-1β levels. The reduction in Aβ levels and microvessels deposition could be explained, at least in part, to the enhanced Aβ clearance across the BBB and by ApoE-dependent pathway. In addition, oleocanthal demonstrated an anti-inflammatory effect by reducing astrocytes activation and IL-1β brain levels, which emphasize the importance of considering EVOO and oleocanthal as a potential therapeutic interventions in AD.
The blood-brain barrier (BBB) controls the content of brain interstitial fluid due to the presence of high-resistance tight junction proteins between the endothelial cells of brain capillaries. Several models using different cell-lines were developed to study the BBB biology, these models were complex and their use for high-throughput screening (HTS) has proven to be challenging. Therefore, we developed an in-vitro BBB model that is practical and reliable for HTS. The mouse brain endothelial cells (bEnd3) grown on 96-well plate inserts were upgraded and optimized for HTS assay. Using Lucifer Yellow (LY) permeation assay, 3 different compounds libraries that include 3000 compounds were screened for hits that have the potential to modulate the BBB model integrity. To evaluate the model ability to identify compounds that increase LY permeation, mannitol was used as a positive control for disruptors. The model performance in this assay was high with Z' factor above 0.5 and high S/N and S/B ratios. Alternatively, hydrocortisone was used as a positive control for compounds that enhance the barrier function as it is known to improve endothelium tightness. The Z' factor determined with hydrocortisone was 0.3 with lower S/N and S/B ratios compared to mannitol .The primary screen has identified several hundred of modulators. The secondary screen could identify 13 compounds as potent enhancers of the monolayer integrity with EC50 values less than 10 μM. In conclusion, an HTS-BBB model was developed and used for compounds screening to identify compelling hits for further evaluation for their effect on the BBB.
Halloysite clay is a naturally occurring clay nanomaterial which with length of approximately 1000 nm, a diameter of 50nm and a lumen of 15nm. Traditionally, halloysite is used for ceramics and as an inorganic reinforcing material for polymers. The 15 nm lumen can be loaded with bioactive molecules such as antibiotics and proteins. By doping loaded halloysite into polymers one can achieve a controlled sustained release of the desired molecule into the matrix. The differing chemistries inside and outside the lumen present avenues to modulate the loading and release patterns and attributing smart properties to halloysite-polymer composites. Typically, the addition of 5-8 % wt. halloysite synergistically increases polymer strength by 30-70 %, enhances composite adhesiveness and adds new functions due to release of the bioactive molecules. Halloysites are regarded as environmentally safe and biocompatible as demonstrated by experiments with cell cultures, microworms and small animals. This enables the application of halloysites as slow and sustained release vehicles of antibiotics for bone implants and dental composites. Bioactive molecules like dexamethasone, furosemide and resveratrol were released from the halloysite lumen over 20 - 30 hours.
The World Health Organization (WHO) warns neurodegenerative diseases (ND) in our aging population will sharply increase over the coming decades. Developing biological tools is paramount in the search for novel therapies to stop the onset or halt the progression of ND. We have developed a novel genetic method MACT (Mosaicism with AAV mediated Conditional Transgenesis) for single neuron analysis. MACT integrates the retrograde labelling capability of AAV and a conditional genetic reporter mouse model for sparse genetic labelling to reveal detailed morphology of different cellular types. As proof of principle, we subsequently subjected MACT mice to a middle cerebral artery occlusion (MCAO) leading to extensive neurodegeneration. Using two-photon imaging and 3-D reconstruction, we have illustrated the robust neurodegeneration of cortex pyramidal neuron, striatal medium spiny neuron and caught in action the engulfment of neurons and blood vessels by microglia. Moreover, we've documented dramatic axon degradation consistent with Wallerian pathology while the cell bodies remain intact ("dying back"), opening the possibility of therapeutic intervention. We also observed unexpected Tyrosine Hydroxylase (TH) positive cell bodies in the striatum, suggesting the brain responds to neurodegeneration by expressing these TH cells in an attempt to compensate for dopaminergic denervation. Most notably, we've developed a novel genetic method to visualize neuron morphology and gain a more accurate understanding of the cellular mechanisms underlying neurodegeneration. MACT represents a powerful genetics method to explore therapeutic interventions, including opto-and chemo-genetics in neurodegenerative diseases in vivo.
The measurement of cellular metabolism involves observation of multiple metabolites. Chemical reaction pathways which occur within the cell may be measured in the extracellular matrix. A fluorophore/polymer based portable sensor was developed which does not consume metabolites, is noninvasive, improves sensor measurements and may be used in standard 24-well plates. The sensor rapidly detects physiological changes without contaminating cell cultures with fluorescent dyes. The sensor uses an oxygen sensitive fluorophore, platinum octaethylporphyrin, embedded in a polymer matrix to measure extracellular O-2 concentration changes in response to an external physiological antagonist. The sensor design was able to acquire real-time measurement of metabolite concentration changes in the extracellular matrix.
The measure of Generalized Partial Directed Coherence (GPDC) and surrogate data analysis of intracranial electroencephalographic (iEEG) signals can be used to determine the functional connections between brain sites. Characteristics of the nodes of the thus derived network during seizures from 9 patients with temporal lobe epilepsy were studied using centrality measures (Degree, Eigenvector, Katz, PageRank, and Betweenness). The electrode sites with maximum Katz and degree centralities showed close association with the epileptogenic focus during seizures. These results indicate that connectivity analysis of the EEG can contribute to the accurate localization of the epileptogenic focus in patients with focal epilepsy.
