This research concerns a design and construction of a bone mineral density (BMD) and bone mineral content (BMC) measurement system based on dual energy X-ray absorptiometry (DEXA). An indirect X-ray detector is designed by optical coupling CMOS sensor with image on the intensifying screen. A dedicated microcontroller X-ray apparatus is used as an X-ray source to capture two energy level X-ray of middle phalanges bone of middle finger. The captured image is processed based on modified Beer-Lambert law to compute bone mineral density. Bone mineral content is also computed by determining the area of the phalanges bone using active contour. The designed bone mineral density (BMD) and bone mineral content (BMC) measurement system is low-cost and hence can be distributed at district hospital for screening purposes of Osteoporosis of the elderly. Compared with BMD measured from commercial model, BMD measurement of our system acquires linear relation with R2 equals 0.969. The mean square error between the normalized BMD value and that of the commercial model is 0.0000981.  Bone is the basic unit of the human skeletal system that provides the framework and bears the weight of the body, protects the vital organs and supports mechanical movement of human body. Bone consists of the protein collagen which is the fiber link with a calcium phosphate salt, a substance that makes bones strong. Calcium salts in bone is accounted for 99 percent with 1 percent is in the blood. Osteoporosis is a condition that causes weakening of the bones because the mineral calcium in the bones decreases. Osteoporosis is a cause of humpback and bone fragility. Osteoporosis is called the “deadly silence” because the symptoms of the disease will move forward all the time without warning before. The patient will know when the bone has broken already. Osteoporosis was found in women than men because women have bone mass less than men. When women are menopausal and hormone estrogen decrease, which helps calcium to hold the bone down.2 of 0.92 is claimed for the linear relation between TTP and BMD. The proposed method of Lee et al. also suffered from bone thickness dependent and X-ray exposure parameter setting dependent. To solve the drawbacks of thickness dependent and X-ray exposure parameter setting dependent, modified Beer-Lambert law using two energy levels of X-ray are used to derive bone-mineral density . The curve can move on the image plane under the influence of two types of forces-internal and the external forces. The former constrains the snake to be smooth while the latter guides the snake to seek desirable image properties, such as edges. The external forces are computed from the image data. Such an active contour model seeks to minimize the following functional ,(14)ESnor force  has beenTo implement GVF active contour, the initial contour, mostly circle, is placed inside the object. Force of GVF computed from edge image is then iteratively drive the initial contour to the edge contour. The process to determine bone mineral density can be divided into 2 processes, i.e., (i) preprocess and (ii) measurement process. Preprocess can be carried out in daily basis while measurement process must do every time when bone mineral density determination is needed. The preprocess is used to derive the detector image of incident X-ray (i)Preprocess for Bone Mineral Density DeterminationStep (i)Turn on X-ray and set tube current at 25 mAStep (ii)Set tube voltage at high kVp. With no object, start X-ray exposure for 40 ms. X-ray detector captures and saves captured image as Step (iii)Set tube voltage at low kVp. With no object, start X-ray exposure for 40 ms. X-ray detector captures and saves captured image as (ii)Measurement Process for Bone Mineral Density DeterminationStep (i)Turn on X-ray and set tube current at 25 mAStep (ii)Set tube voltage at high kVp. With object, start X-ray exposure for 40 ms. X-ray detector captures and saves captured image as high-energy level detector image Step (iii)Set tube voltage at low kVp. Start X-ray exposure for 40 ms. X-ray detector captures and saves captured image as low-energy level detector image, Step (iv)ComputeStep (v)Compute bone mineral density Equation (12)Step (vi)Compute area using GVF active contour and bone mineral content Equation (13)We conducted experiments into 2 categories including X-ray detector calibration experiment and bone mineral density experiment. The objective of X-ray detector calibration experiment is to seek the optimal exposure setting for dual exergy X-ray and to test the characteristics of X-ray detector. The objective of bone mineral density experiment is to test the performance of bone mineral density system both on calcium phantom and on human subject. To test the reliability of the indirect X-ray detector, we perform linearity test, resolution test and repeatability test. Linearity test is to establish the range of tube voltage setting for each tube current setting. The dedicated microcontroller X-ray apparatus can set the tube voltage from 40–100 kVp with an increment of 2 kVp per step. Two tube current can be set which are 25 mA and 50 mA. To perform linearity test, tube volage is set from 46 kVp to 100 kVp for each tube current setting. With no object, X-ray exposure is activated while the X-ray detector captures the image of intensifying screen. Synchonized trigger is used to capture image automatically. Averaged intensity for each setting are plotted against the kVp setting. The result is depicted in The next experiment for X-ray detector calibration is repeatabilty test. To ensure the robustness of our detector, we test the X-ray detector at the same setting for high and low energy level for 10 times. The standard deviation of the averaged intensity is computed. Result is shown in Resolution test is also performed on the X-ray detector. Many factors can affect the resolution of the detector including focal length (filament size) of the X-ray tube, type of image intensifying screen, resoultion of detector, i.e., the CMOS sensor. We have tested resolution of our X-ray detector using flouroscopic quality control test tool model 07-637. The results in 2. 2 of 0.998. Prior to test the proposed bone minereral density measuremenst system with human subject, we have tested the system with calcium phantom. The calcium phatom is created by mixing 40 g of plaster power, 80 mL of water and vairious amount of calcium powder starting from 10 g to 100 g with an increment of 10 g. The dimension of calcium phantom is 4 cm × 14 cm × 0.8 cm (W × L × H) and hence the top surface area of the phantom is 56 cm2 equals 0.969. The BMD measurement of our system can be normalized to the BMD value of the commercaial model using linear equation y = 0.4285 + 0.7482x. The normalized BMD value is plotted against the BMD value of the commercaial model as shown in The proposed bone-mineral density measurement system has been tested with 6 male subjects with age between 25–29 years. The measurement is compared with commercial bone-mineral density measurement apparatus model DSC-600EX ALOKA which is also based on dual-energy X-ray. The results of bone mineral density and bone mineral content using our proposed system is shown in To provide mobility of our system, we have designed a portable bone-mineral density measurement system based on dual energy X-ray proposed by this manuscript as shown in This research concerns the design and construction of low-cost bone mineral density measurement system based on dual energy X-ray. X-ray source used in our research is a dedicated microcontroller X-ray apparatus with is communicated to personal computer using serial communication. X-ray detector is key contribution of this research. An indirect X-ray detector is designed using one or multiple CMOS sensors capturing image on the intensifying screen and transferring the image to personal computer via USB port for further analysis. Despite the promising result when compared with the measurement from the commercial model, there are a number of issues that are needed to be discussed for the completeness of the manuscript.(i)When compared the results of our bone mineral density measurement system with the measurements from the commercial model, our BMD seems to be underestimated. There are factors that may cause the underestimation. One of the factors is the error of the setting kVp X-ray tube voltage from the true value of tube voltage. To compute bone mineral density using modified Beer Lambert law, mass attenuation coefficient of bone and soft tissue are needed. The mass attenuation coefficient is a function of X-ray energy which depends on the kVp supplied to the X-ray tube. Any error of tube voltage could directly result the error in bone mineral density measurement. The other factors may cause by the low sensitivity of our indirect X-ray detector upon compared with the X-ray detector used in the commercial mode which is more sensitive. Despite the measurement error, however, the error related to hardware is consistent and hence compensable through calibration.(ii)Our proposed bone mineral density system aims to be used for screening process at district hospital. The measurement results may inform patient with low risk, moderate risk, and high risk of bone mineral deficiency. For those with medium to high risk will be recommended to have further diagnosis with commercial model of bone mineral density measurement at the center hospital. Our system does not intend to use for osteoporosis diagnosis as the diagnosis requires statistical analysis of bone mineral density data from a large population.(iii)The effective dose of the subject using the proposed bone mineral density system is equivalent to two times the effective dose of extremity radiograph which is about 2 μSv . In mode(iv)The area determination is based on active contour and hence requires the placement of initial contour. The initial contour which is a circular contour with diameter 50 pixel must be placed inside and at the center of the middle phalanges of the middle finger. In the real experiment, the subject hand must be fixed in position so that the X-ray central ray is at the center of the middle phalanges. To convert pixel unit to physical unit, image of a known dimension of square metal object exposed with X-ray is captured with the indirect X-ray detector.(v)2O2S: Tb intensifying screen is 545 nm. The spectral response of the CMOS sensor is not specific at any wavelength but the whole visible light. The efficiency is hence not as good as the commercial where the response of the emitted light and detector is perfectly matched. To improve efficiency, high-sensitive CMOS sensor can be used.The proposed indirect X-ray detector is the main contribution of the research. The cost of construction is very low when compared with commercial detector. This make to overall cost of the proposed bone mineral density system is almost 10 times cheaper than the commercial model. There are two issues of X-ray detector are needed to be addressed. First, our detector used CMOS sensor. Modern CMOS sensor can achieve up to 12 Mega pixels. This makes the proposed X-ray detector upgradable with reasonable cost. Furthermore, by concatenating more CMOS sensors, more pixels covering the same active area, the resolution can be increased. Second, the intensifying screen used in the X-ray detector also affects the performance. Normally, there are two types of intensifying screen which are high resolution and high sensitivity type. For high resolution type, the X-ray phosphor grain size is smaller than that of the sensitive one. However, the resolution type is less sensitive. In our research, we opt to use the sensitive screen by considering the fact that the highly sensitive type requires low effective dose than the high resolution. The efficiency of our X-ray detector however is not as good as the commercial one. The light emitted from Gd(vi)One the important factor in determining dual energy level for DEXA is k-edge effect. At the k edge, X-ray energy drops rapidly due to the photoelectric phenomenon. To avoid k-edge effect, many techniques can be used including using X-ray detector with k-edge filter or setting the two-operating point above the k-edge energy level. The k-edge of calcium in the bone which is considered as high atomic number is about 4 kev. In general, the k-edge of bone is below conventional diagnostic energies, the tail of k-edge does fall into diagnostic energies. As a result, bone absorbs much more of the lower energy X-rays than soft tissues do. Our proposed dual energy X-ray absorption apparatus set the high and low X-ray energy level at 40 kVp and 72 kVp, respectively. The average energy is approximate 1/3 of kVp. The average kev for high and low X-ray energy level are 13 kev and 24 kev, respectively, which is above the k-edge of calcium.This research concerns the design and construction of a low-cost bone mineral density and content based on dual energy X-ray absorption or DEXA. The system consists of two main components: (i) X-ray controller and (ii) X-ray detector. X-ray controller is the dedicated microcontroller 50-mA X-ray apparatus that is interfaced with personal computer via serial communication. Our X-ray detector is designed by using a CMOS sensor capturing image from conventional X-ray intensifying screen. The captured image is transmitted to personal computer for further processing. Bone mineral density system is controlled by inhouse software installed on the personal computer. The inhouse software will control sequence of bone mineral density and content measurement process and the post processing related to digital image processing that uses OpenCV. Bone mineral density and content will measure on the phalanges of the middle finger. To derive bone mineral content, area of phalanges is needed. We exploit the principle of GVF active contour for area computation. The initial circular contour is placed in the middle of phalanges. The GVF external force compute from edge image is then iteratively drive the initial contour to fit the phalanges contour. A number of tests have been performed on the X-ray detector including linearity, repeatability and resolution test with satisfactory result. Performance tests have been conducted on the calcium phantom with known calcium content and on human subjects. Compared with the measurement derived from the commercial DUXA, after being calibrated our bone mineral density measurement system can provide the measurement close to that of the commercial with mean-squared difference of 0.00981%.


These outcomes support potential translation of the patient-specific AM prostheses to reconstruct large bone defects following tumor resection.Design and processing capabilities of additive manufacturing (AM) to fabricate complex geometries continues to drive the adoption of AM for biomedical applications. In this study, a validated design methodology is presented to evaluate AM as an effective fabrication technique for reconstruction of large bone defects after tumor resection in pediatric oncology patients. Implanting off-the-shelf components in pediatric patients is especially challenging because most standard components are sized and shaped for more common adult cases. While currently reported efforts on AM implants are focused on maxillofacial, hip and knee reconstructions, there have been no reported studies on reconstruction of proximal humerus tumors. A case study of a 9-year-old diagnosed with proximal humerus osteosarcoma was used to develop a patient-specific AM prosthesis for the humerus following tumor resection. Commonly used body-centered cubic (BCC) structures were incorporated at the surgical neck and distal interface in order to increase the effective surface area, promote osseointegration, and reduce the implant weight. A patient-specific prosthesis was fabricated using electron beam melting method from biocompatible Ti-6Al-4V. Both computational and biomechanical tests were performed on the prosthesis to evaluate its biomechanical behavior under varying loading conditions. Morphological analysis of the construct using micro-computed tomography was used to compare the as-designed and as-built prosthesis. It was found that the patient-specific prosthesis could withstand physiologically-relevant loading conditions with minimal permanent deformation (82  In recent years, the inherent layer-by-layer characteristic of additive manufacturing (AM), commonly referred to as 3D printing, has provided new opportunities to meet medical needs . One of Osteosarcoma is an invasive bone tumor which primary occurs during the pubertal growth spurt followed by late adulthood (age of 70–85 years) , 7. The Pediatric patients diagnosed with osteosarcoma face a lower survival rate and higher rate of revision surgery when compared to adult patients . A critiOn the other hand, unique design and manufacturing capability of AM offers the potential for a systematic design, fabrication and evaluation of new workflow to produce patient-specific implants for tumor reconstruction. Patient-specific implants could potentially reduce the risk of intra- and post- operative complications. It has been proposed that tailoring surgical options to the patient’s anatomic defects and functional requirement could substantially reduce or eliminate intra- and post- operative complications . PreviouTo the best of the authors’ knowledge, this is the first reported study on the reconstruction of proximal humerus after tumor resection using AM . The aimThis study was approved by CATS IRB—Penn State’s Centralized Application Tracking System for Institutional Review Board applications. This study included the use of pediatric patient image data retrospectively. Additionally, in the associated approved IRB protocol (IRB study #: 005099), waiver of informed consent was requested. IRB-approved magnetic resonance imaging (MRI) data of a 9-year-old patient diagnosed with proximal humerus osteosarcoma was obtained . In the Vp corresponds to the volume of the porous media and Vs is the volume of the replacing solid media. The target porosities of cellular regions in the designed implant were chosen to mimic those of trabecular bone (50–95%) [The geometrical variations in cross-sections were incorporated into the design of the prosthesis shaft . The dis(50–95%) –22 and tThe patient-specific prosthesis was fabricated using an electron beam melting (EBM) machine  which is a powder bed fusion technique . Stereol25.08 mm . Sandbla5 cycles [5 cycles correspond to 8–10 weeks of rehabilitation [The fabricated AM prosthesis was tested under cyclic loading in a universal test frame . A custom-made fixture was prepared to emulate physiologically relevant loading conditions by securing the prosthesis stem in the test frame . Prior t5 cycles . Here, 55 cycles ; therefolitation , 26. StiFEA of the prosthesis under quasi-static loading was performed in Abaqus/CAE v6.13 . Due to limitations in extracting parametric CAD models of highly complex BCC porous structures for computationally efficient finite element modeling (FEM), polygonal surface model  was extracted from ElementPro. An open source program (GMSH)  with DelOver the course of five years during clinical follow-up, patient’s body weight was within the range of 49–54 kg. Hence, 520 N body weight was used to determine loads used in FEAs. In order to predict the performance of the designed prosthesis, three different loading and boundary conditions, based on patient’s body weight, were investigated via FEA  to simulIn the case of S1 which mimics the biomechanical test setup, stem of the prosthesis was kinematically coupled to a Reference Point (Load-RP) that was constrained in five degrees of freedom and only free for translational motion along the z-axis. The rigid body plate (mimicking the machine platen) that contacts the proximal head of the prosthesis was constrained in all six degrees of freedom. Interaction between the head of the prosthesis and the rigid plate was modeled as isotropic coulomb friction with a coefficient of 0.1 .In S2 and S3 FEA, stem of the prosthesis was kinematically coupled to a reference point which was constrained in all degrees of freedom. In these models, Load-RP was located proximally and kinematically coupled to the surface nodes of the proximal head. In all the FE models, boundary conditions similar to the experiment was implemented; this included constraining the distal about rotation. Joint reaction forces reported by previous in-vivo study  for commμm. Images from the micro-CT revealed the presence of trapped powders in some of the pores. In order to automate the segmentation of voxels with varying grayscale  in Avizo , the Trainable Weka Segmentation (TWS) [The patient-specific prosthesis was scanned using a micro computed tomography (micro-CT) scanner  before and after biomechanical testing. In this study, 300 kV microfocus X-ray was employed to scan the prosthesis before and after cyclic loading with a voxel size of 100 on (TWS)  plugin ion (TWS)  was emplon (TWS) , 37. SegP/AS)), and tortuosity calculation included the presence of trapped powders to evaluate the true morphological parameters of the as-built AM prosthesis.Morphological characterization was performed on the segmented data using the pore-network tool in Avizo. Porosity at both the surgical neck and the distal interface was evaluated before and after biomechanical testing. Pore size was computed from the diameter of the maximum sphere that fits within the pores. Pore connectivity and strut size were analyzed using thickness map function in Avizo. It should be noted that strut size measurements from micro-CT data were performed by excluding the trapped powders in order to isolate the effects of load-carrying solid struts. However, pore size, porosity, increase in surface area , maximum valley depth , maximum surface height , arithmetic mean surface height , and root mean square surface height  were reported in accordance with ISO-25178 and ISO-4287.Surface morphology of the 3D printed prosthesis was evaluated using an optical microscope   . Due to μm permanent deformation of the overall construct (as measured net crosshead displacement throughout the course of testing) through 105 applied cycles  was 14.5% higher than the experimental result (1846 N/mm) which corresponded to the mean stiffness of initial 5–10 cycles AM fabrication and post-cleaning process for the designed prosthesis took less than 24 hours. Micro-CT scans of the prosthesis (after sand blasting) revealed presence of residual trapped powders in the porous regions. These trapped powders had 19.44% of the designed void space at the surgical neck and distal interface of the implant together . MorpholSaand Ra, in this study were within the recommended range of surface roughness for metallic load-bearing implants [Surface morphology analysis  was performed on the patient-specific prosthesis using optical non-contact microscopy . As-builimplants –44 to prIn this study, validated FEA and experimental analysis showed that AM prosthesis, based on the proposed design workflow, can withstand physiologically-relevant loads without experiencing apparent catastrophic failure. In this study, commonly used BCC open-cellular structure  was emplμm which is substantially lower than the accepted upper threshold of micromotion without disturbing the natural bone tissue healing process. From the FE analysis (in the S1 loading condition) highest stresses were located at the medial aspect of the porous surgical neck. This observation is attributed to the bending stress since the medial aspect of the surgical neck also experienced higher strain. In addition, slight increase in the cyclic stiffness was observed which could be attributed to small angulation of the prosthesis and/or compliances in the fixtures during the experiment.The cyclic biomechanical testing of the AM prosthesis resulted in a permanent compressive displacement of 82 In this study, linear elastic isotropic material model was used for the AM Ti-6Al-4V patient-specific prosthesis which may not accurately replicate the material model for AM implants . Additionally, effects of the muscle forces to the biomechanical behavior of the prosthesis were ignored. In order to gain better insights into the biomechanical responses of patient-specific implants, muscle reaction forces need to be integrated into the FEMs. This study was also limited to one sample size, in order to gain statistical power, larger sample size needs to be used.Similar to other investigations –52 into This study provides preliminary evidence supporting patient-specific AM prostheses for the reconstruction of large bone defects in oncology patients, specifically pediatric patients. The proposed patient-specific prosthesis included volumetric porous structures at the surgical neck and distal interface. Large pore size at the surgical neck could potentially facilitate suturing of the tendons into the implant while also allowing for direct tissue ingrowth onto the implant. Similarly, the distal porous interface allows for bone ingrowth since the distal dissection usually carried out to the level of osteotomy to prevent osteonecrosis of the remaining bone segment. Another unique design feature in the studied implant was the somewhat triangular-shape of the stem which would lock the rotational alignment of the implant due to the matching shape with the triangular marrow cavity. Together, porous distal interface and the marrow cavity-shape stem could reduce the risk of future periprosthetic loosening. Although direct clinical application was beyond the scope of this study, the AM patient-specific prosthesis was designed to fit the anatomy without the need for glenoid replacement given the opportunity of suturing the host rotator cuff and capsule to the porous surgical neck. And if the glenoid were to become arthritic in the future, conversion to a total shoulder arthroplasty with glenoid resurfacing could be carried out. It is worth highlighting that the proposed AM prosthesis may only be considered in patients near the end of growth or skeletal maturity in order to avoid any limb length discrepancy issues associated with growth.In this work, EBM process was employed to manufacture the designed patient-specific prosthesis in less than 24 hours. The EBM process was performed at an elevated temperature of 750°C (layer temperature) which results in stress relieved parts (cool-down) with material, mechanical, and chemical properties potentially better than cast and wrought forging . Therefoμm voxel resolution. Large deviation in the calculated morphological parameters (between as-designed and as-built) could be partly attributed to the effects of sandblasting. During the sandblasting process, exterior struts are more prone to undesired material removal when compared to interior cellular structures. This may have caused variation in strut size, interior struts having larger strut diameter with exterior struts showing smaller diameter. Such variations resulted in large pore size deviations across each porous region. This partly explains the higher average pore size values (with relatively large standard deviation) in the 3D reconstructed as-built model as compared to the as-designed values. In addition, ineffectiveness of the sandblasting process in completely removing trapped powders could be associated to line-of-sight limitations that restricts the permeability of sand particles within the pore spaces. Micro-CT analysis of the pre- and post- biomechanical testing of the prosthesis showed minor deviation in the morphological parameters considering that post-process the micro-CT data is a subjective process. Despite that, it should be acknowledged that presence of trapped powder particles in the implant needs to be addressed. Further investigation in establishing an effective post-processing protocol is recommended to eliminate any entrapped powder particles in the implant after vigorous cleaning and sterilization process. Additionally, future studies should further investigate alternative approaches to minimize or eliminate presence of trapped powder particles in such implants, either by replacing beam-based unit cells with surface-based topologies  [Structural and morphological comparisons between as-designed and as-built (using micro-CT) revealed the presence of trapped powders in porous regions which contributed to the observed deviations in the morphological parameters such as pore size, porosity, tortuosity, and effective surface area. Concentration of the trapped powders was small in the surgical neck, when compared to the distal interface porous region, and was only found in pores that were close to solid surfaces . However, due to small pore size in the distal interface compared to the surgical neck, increase in volume of the trapped powders was observed. Reduction in porosity and effective surface area from as-designed to as-built is partly attributable to the presence of trapped powders. When comparing micro-CT data between pre- and post-experiment, negligible variations (<6%) in morphological parameters were found. In addition, no structural deformities or micro-damage was observed in the micro-CT data at 100 urfaces) , 55 or cThis study provides a systematic workflow for the design-fabrication-evaluation of patient-specific prosthesis for reconstruction of the proximal humerus following tumor resection, specifically in pediatric patients. Following conclusions are drawn from the outcomes of this study:Both validated FEA and experimental analysis showed that the proposed patient-specific AM prosthesis provides adequate biomechanical strength under physiologically relevant cyclic loading conditions without experiencing catastrophic or structural failure.Micro-CT evaluation of the AM implants provides comprehensive information on morphological parameters including deviations in morphological parameters between as-designed and as-built implants. Those deviations could be partly attributed to trapped powder inside the porous regions of the prosthesis.Self-intersecting lattice structures (such as BCC) are prone to high stress concentrations at the strut junctions under cyclic loading.Additional clinical studies are required to evaluate the effectiveness of patient-specific AM prostheses to eliminate residual deformities and improve implant fixation. This could be valuable in uniquely challenging cases such as pediatric bone tumor resection.


The objective of this work is to develop a fusion artificial intelligence (AI) model that combines patient electronic medical record (EMR) and physiological sensor data to accurately predict early risk of sepsis. The fusion AI model has two components—an on-chip AI model that continuously analyzes patient electrocardiogram (ECG) data and a cloud AI model that combines EMR and prediction scores from on-chip AI model to predict fusion sepsis onset score. The on-chip AI model is designed using analog circuits for sepsis prediction with high energy efficiency for integration with resource constrained wearable device. Combination of EMR and sensor physiological data improves prediction performance compared to EMR or physiological data alone, and the late fusion model has an accuracy of 93% in predicting sepsis 4 h before onset. The key differentiation of this work over existing sepsis prediction literature is the use of single modality patient vital (ECG) and simple demographic information, instead of comprehensive laboratory test results and multiple vital signs. Such simple configuration and high accuracy makes our solution favorable for real-time, at-home use for self-monitoring. Real-time, continuous at-home health surveillance leveraging AI can significantly improve outcomes for sepsis by providing early alert to patients and allowing them to seek timely medical intervention which may significantly reduce the mortality rate.The USA has one of the highest healthcare costs in the world even though it lags behind peer nations in health outcomes. Advances in artificial intelligence (AI) and continuous health surveillance technologies can alleviate some of the healthcare burden through early detection of health issues. Our objective is to develop on-chip AI circuit that will continuously monitor physiological signals and build a fusion model to predict early risk of clinically adverse event to increase the management time and prevent adverse outcome see Fig. . In this2, have demonstrated the utility of wearable device for continuous health monitoring, there are several challenges and limitations associated with the current technologies - 1. existing wearable devices lack the ability to integrate electronic medical record (EMR) with sensor data in real-time, even though EMR is known to have a strong influence on health abnormality detection6; 2. most wearable devices do not have automated inference capability and depend on telemetry and medical experts for actionable inference; 3. the current framework of performing AI analysis in the cloud increases risks of breach in patient data during transmission over the network8. The proposed work addresses these challenges through a two-step fusion AI framework—an AI circuit that can be integrated with wearable device for performing in-situ analysis of continuous sensor data, and a cloud AI model that performs fusion of demographic data and scores from embedded AI circuit for real-time risk prediction of sepsis onset. Raw patient data collected through wearable device is not transmitted to the cloud; rather only prediction scores of the embedded AI circuit is sent to the cloud for fusion which improves robustness against eavesdropping attacks on the patient’s sensor data.While recent clinical trials, such as the Apple Heart Studyfusion AI solution partitions the data analysis into ECG and EMR data models  have been shown in Table Experiments in the study were carried out following the World Medical Association (WMA) developed ethical protocol for conducting ethical medical research. The model was trained and tested on 965 unique patients (514 sepsis and 451 non-sepsis) from Emory Healthcare system and the sepsis onset time is defined by Sepsis-3 definitionsetting 1: late fusion was performed using demographic, and ECG data; setting 2: late fusion was performed using demographic, co-morbidity, and ECG data. Late fusion was performed for 1 h to 6 h before the sepsis onset time. Figure In order to improve the accuracy for early prediction, we developed a late fusion model where we trained a meta-learner on the prediction scores of on-chip ECG model and EMR models to integrate the information from two data sources. Table Fusion models in general improved the baseline EMR model performance from 76 to 93% for 1 h and 86% for 6 h prediction before the sepsis onset. The baseline EMR model’s AUROC values also improved from 0.79 to 0.99 for 4 h prediction task Fig. . An inteWe designed a graphical mobile application for easy adaptability from the user view-point Fig. . After iIn this study, we developed an innovative fusion AI solution for sepsis prediction and demonstrate the performance on varying prediction time-points. Core novelty of this work is—(1) the first on-chip ECG model with fusion AI achieved state-of-the-art accuracy for sepsis prediction; (2) analog in-memory computing (IMC) for high energy efficiency AI model in the ECG wearable. In order to support our novelty claim, we compared our solution with the existing literature in both AI and analog domain in the following subsections.15 has higher accuracy, but requires 26 different laboratory test results and 8 different patient vital signs. The work by16 uses a fusion technique to combine EMR and patient vitals, but requires 11 laboratory test results, 18 culture tests, 6 vital signs and 30 co-morbidities which is only feasible in a hospital setting. None of the existing AI models are implemented within the ECG sensor attached to the patient body for real-time risk inference while preserving the data privacy.Table 30.Energy efficiency of traditional AI computing systems are limited by communication costs of bringing together many input activations, and neuron weights, and distributing output activations in Von-Neumann architectures with separate memory and computing units. Wearable sensors have low energy budget which cannot accommodate conventional AI computing systems. IMC can break the Von-Neumann bottleneck by massively parallelizing computations and drastically reducing communication costs by performing computations using memory units. In this work, we perform analog IMC by using the capacitors that store the ANN weights to perform vector matrix multiplication. The complete vector matrix multiplications across all the neurons in each layer are performed simultaneously, and the results are stored locally in charge-domain on the shared top-plate of the capacitors. Vector matrix multiplication using capacitive IMC has high accuracy since arithmetic computation through passive charge sharing/redistribution is highly linear, and is less sensitive to random variations introduced during chip fabrication. Thanks to the analog IMC, the complete on-chip AI circuit consumes 7.4nJ/inference which is at least one order-of-magnitude lower than state-of-the-art medical ML ICs that consume hundreds of nJ to few 31. From the high-level overview, we found that many groups, specially for predictions 1 h before sepsis onset, did not have equal or statistical parity, e.g. white population has low FPR disparity compared to black population, and patients aged over 61 have high FPR disparity compared to patients in the 41-60 age group. The disparity trend is similar but moderate for prediction 4 h before sepsis onset. This disparity is primarily caused due to proportional disparity in the Emory ICU population.Our study has several limitations. First, the proposed architecture is only validated retrospectively on the dataset from a single institution - Emory University Hospital with high number of elderly patients (ICU records 2014-2018). Model trained on a single institution data may contain heavy bias towards the training population. We performed a race, gender, ethnicity and age based disparity analysis to understand the effect of bias using disparity measure of false positive rate (FPR) which is the fraction of false positives within labeled negatives of the group, and is critical for clinical event prediction , the de-identified sepsis dataset is obtained from Emory University Hospital (EUH). Since we used only de-identified data and no patient communication has been made during the study, the need of informed consent is waived by Emory IRB. All methods were carried out in accordance with relevant guidelines and regulations (Declaration of Helsinki). The cohort consisted of 965 patients admitted to the ICUs at two hospitals within the Emory Healthcare system in Atlanta, Georgia from 2014 to 2018. For each patient, there is at least 8 h of ECG signal recordings from the time of admission in the ICU, with the ECG signals sampled at 300Hz. Table 14, criterion was used to assign sepsis onset time (tsepsis-3) when two conditions were simultaneously satisfied: (1) there was a clinical suspicion of infection (tsuspicion) and; (2) there was a two point increase in SOFA score (tSOFA). According to Sepsis-3 definition, the cohort consisted of a total of 965 patients, 514 of whom met the Sepsis-3 criterion.The Third International Consensus Definition of Sepsis (Sepsis-3)The ECG AI model is completely integrated within the analog sensor device. We designed a feature generation block that pre-processes the sensed signal by removing baseline wander, and then extract the pre-defined features. In the second stage, the extracted features are analyzed by the on-chip Artificial Neural Network (ANN) for the sepsis risk prediction.ECG signal pre-processing and feature extraction are all performed on-chip, and hence, needs to be low-power without sacrificing accuracy. The ECG signal is normalized between  before digital pre-processing and feature extraction. To remove baseline wander, we calculate median value of the ECG signal window and subtract it from all the samples in that window. For feature extraction, we consider only time-domain features based on first-order statistics of R-R peaks. While feature extraction in the literature is performed in both time-domain and frequency-domain, we choose only time-domain features since they are easy to compute on-chip at low power, compared to frequency-domain features which requires computation of frequency transform of the ECG signal. Frequency transform using fast fourier transform (FFT) is computationally expensive and consumes orders-of-magnitude higher power than time-domain features. We extract 14 time-domain features on 9000 samples ECG segments (30 s window). The extracted features are summarized in Fig. Figure 35, the proposed approach reduces transistor count, and hence, area. The proposed activation circuits use transistors biased in saturation region to minimize mismatch and noise. This is in contrast to existing analog techniques which bias transistors in sub-threshold to exploit exponential relation between drain current and gate voltage of transistors to implement tanh/sigmoid activation functions. Biasing transistors in sub-threshold region increases mismatch and reduces signal-to-noise ratio (SNR) compared to biasing in saturation region. Figure 30.Analog circuits are used to realize the ANN model in hardware. The digital features from the feature extractor are converted to analog form through 4-bit switched-capacitor digital-to-analog converters (DACs) before feeding to the analog ANN. The ANN performs multiply-and-accumulate (MAC) using switched-capacitors, and uses common-source differential amplifiers to realize tanh and sigmoid activations by leveraging intrinsic nonlinearity of transistors. The switched-capacitor MAC circuit intrinsically ensures that the input to the activation functions is bounded between . Figure 37 we developed an error-aware hardware-software co-design interface in which SPICE simulations are used to characterize a unit activation function, and the characterization data is imported into Matlab for training the ANN  10th revision. In order to maintain standardization and easy at-home use, we obtained mapping between disease names and ICD10 codes, and integrated the capability in the end-system to automatically map the disease name to the nearest ICD10 code. EMR data obtained underwent a series of pre-processing steps prior to formal analysis and model development.Given the wide range of ICD10 codes , we leverage the ICD10 disease description as string to obtained the embeddings of multiple comorbidities. The EMR data elements were both categorical  and textual (ICD10 code descriptions) datatype. As the first data pre-processing step, we applied standard data cleaning steps, including removing empty cells, special characters. For the conversion of categorical features to numerical quantities, we use the label encoding technique. As per this technique, each value in a column is converted to a specific number.38. A word t in the j-th ICD10 code is represented in the following vector formatt. We trained the TF-IDF tokenizer using our training dataset and obtained The vectorization of ICD10 code descriptions was performed using Term Frequency- Inverse Document Frequency (TF-IDF) algorithmFinally the numeric representation of the categorical features and TF-IDF representation of the co-morbidities are combined using linear concatenation. We standardized features by removing the mean and scaling to unit variance. Centering and scaling happen independently on each feature by computing the relevant statistics on the samples in the training set. The mean (SD) is then used on later data , using the same transformation function. The details of the patient characteristics have been shown in Table In order to perform a comprehensive analysis, we experimented with multiple parametric  and non-parametric  machine learning models. Given the static nature of this data, temporal sepsis onset prediction was not relevant and we only design a single prediction model for distinguishing sepsis vs non-sepsis data points using only EMR data. The optimal value of the hyperparameters is derived by analyzing the coefficient of the features computed by the 10-fold cross validation on the training data.We hypothesize that an efficient combination of demographics along with co-morbidities, and multi-modal physiological signal data measured by our sensors will provide a more comprehensive view of a patient’s clinical status compared to an individual modality. We designed a prediction model that considers the feature vectors derived from continuous ECG data and integrate with patient demographics, commodities and baseline vitals. However the challenge was to integrate the static EMR features with the temporal physiological signal data in the same model.We designed a Late fusion model which performed a decision level fusion by leveraging predictions from multiple models (ECG model and EMR model) to make a final decision Fig. . In ordeSupplementary Information 1.


During early embryonic development both the rapid increase in cell number and the expression of genes that control developmental decisions are tightly regulated. Accumulating evidence has indicated that these two seemingly independent processes are mechanistically intertwined. The picture that emerges from studies on the cell cycle of embryonic stem cells is one in which proteins that promote cell cycle progression prevent differentiation and vice versa. Here, we review which transcription factors and signalling pathways play a role in both maintenance of pluripotency as well as cell cycle progression. We will not only describe the mechanism behind their function but also discuss the role of these regulators in different states of mouse pluripotency. Finally, we elaborate on how canonical cell cycle regulators impact on the molecular networks that control the maintenance of pluripotency and lineage specification. Embryonic stem cells (ESCs) are the subject of intense research. These cells derived from the inner cell mass (ICM) of the early blastocyst can be propagated indefinitely in vitro while retaining the transcriptional and epigenetic properties of their in vivo counterparts. As a result, these in vitro cultured cells maintain the ability differentiate into all cells of the fully developed body plan (termed “pluripotent”). Unlimited in vitro expansion allows scaling necessary for molecular analysis and has facilitated unraveling the molecular mechanisms that dictate maintenance of pluripotency and differentiation. The transcriptional network that ensures the pluripotent phenotype of embryonic stem cells is at the core controlled by three Transcription Factors (TFs), OCT4, SOX2 and NANOG. These TFs have overlapping genomic binding sites and uphold a transcriptional network that favors the expression of pluripotency genes and inhibits lineage specifying genes . Cell tyThe identification of pathways that initiate differentiation has also resulted in distinct culture methods that allow self-renew and maintenance of pluripotency. Up to almost one decade ago mouse ESCs were cultured in conditions that included serum components or Bone Morphogenetic Proteins (BMPs) to prevent differentiation. The realization that the BMP acts through the inhibition of fibroblast growth factor (FGF)/extracellular signal-regulated kinase (ERK) signaling paved the way for the development of a serum-free condition that includes two small molecule inhibitors (2i) to support in vitro propagation of pluripotent mouse ESCs . TranscrDuring embryonic development lineage specification is paralleled by a steady increase in cell number. In between mitotic cell division proliferating cells pass consecutively through Gap1 (G1)-phase, Synthesis (S)- phase and G2-phase. Pluripotent cells from the ICM are characterized by extremely short gap-phases that lengthen upon lineage specification during the time of implantation (reviewed by ). StudieThe G1-phase of cells both from the ICM as well as from in vitro cultured naive mouse ESCs is extremely short. If differentiation associated with chromatin remodeling is indeed specifically initiated during G1-phase this characteristic short G1-phase of ESCs could potentially serve as a barrier to prevent differentiation. Although elongation of G1-phase correlates well with differentiation and delaying S-phase entry has been shown to induce differentiation in some cases , 17 fastAccumulating evidence indicates that signaling pathways and transcriptions factors of the core pluripotency network impact the cell cycle. In this communication, we will review how the pluripotency network impacts on the cell cycle, mainly focusing on OCT4, SOX2, and NANOG. Most of the studies on cell cycle regulation in ESCs so far have been performed, however, using naive ESCs. Although the number of reports on cell cycle control in ground state ESCs is still limited they have revealed some striking differences regarding the cell cycle when compared to naive ESCs. Throughout the review, we will also discuss these differences and elaborate on their implications. Finally, we will discuss how cell cycle regulators modulate pluripotency and differentiation.The characteristic of classically cultured naive ESCs is that they lack the control mechanisms that prevent S-phase entry. The canonical pathway that regulates G1-phase progression culminates in E2F activity that drives progression into S-phase. The E2F transcription factors are inhibited by the pocket protein family—consisting of RB, P107, and P130- that in turn are inhibited by CDK/cyclin-mediated phosphorylation. Two families of CDK-inhibitors exist, the CIP/KIP and the INK4/ARF that can inhibit CDK/cyclin complex formation. One of the first observations that explained the characteristic fast ESC cell cycle was the absence of hypo-phosphorylated RB in naive ESCs . SubsequOne possible explanation is that in naive ESCs not only the relative amount of hypo-phosphorylated active RB but also the total RB protein level is low in naive ESCs compared to Mouse Embryonic Fibroblasts (MEFs) . Low RB Although this characteristic ESC-specific cell cycle is fundamentally different from the somatic cell cycle the exact molecular mechanism underlying remained elusive for more than three decades. Below we will discuss how certain signaling pathways and TFs of the core pluripotency network impact on the cell cycle of naive and ground state ESCs.The FGF/ERK-pathway is involved in primitive endoderm formation and germline specification in the early embryo and its inhibition allows to maintain ESCs in ground state pluripotency , 33. ActBesides ERK signaling, the activity of cell cycle regulators is also affected by Wnt signaling which is a crucial mediator of pluripotency . PositivThe differences in cell cycle between naive and ground state ESCs are therefor at least in part the result of lowered CYCLIN D and elevated CDKi expression mediated by FGF/ERK inhibition and stimulation of Wnt signaling, respectively. The addition of the 2i inhibitors to naive ESCs had however a less pronounced effect on the cell cycle when compared to the adaptation to ground state serum-free conditions . In grouSeveral lines of evidence have indicated that members of the pluripotency network employ multiple mechanisms to modulate progression through the G1-phase. Firstly, both OCT4 and SOX2 directly control the expression of long intergenic noncoding RNAs (lincRNAs)  and ESC-Secondly, CDK/Cyclin-mediated phosphorylation of RB is promoted by both SOX2 and NANOG. SOX2 can stimulate cell proliferation either directly as a transcriptional activator of several cyclins –48 or asAlthough MYC is not considered to be part of the core pluripotency network, the MYC family of TFs has a well-established role in stem cell maintenance as well as cell cycle regulation (reviewed by ). MYC isTogether, these results suggest that the abrogated G1-phase in naive ESCs is the result of high FGF/ERK activity and low Wnt signaling. Activation of Wnt signaling leads to transcription of the INK4/ARF locus and P16/P19-mediated elongation of G1-phase. Although inhibition of FGF/ERK induces the expression of P21 and P27 and reinstates the RB/E2F-mediated G1-checkpoint its exact molecular mechanism has not been deciphered yet. Possibly the lowered MYC expression in the ground state compared to naive ESCs contributes to the reinstatement of the G1-checkpoint  cells inspired many to combine this method with genome-wide knockdown or overexpression screens to identify genes that modulate the pluripotency network. Amongst others, many cell cycle regulators were frequently identified to improve reprogramming , 61. AltAlthough there is a general consensus that the main function of CYCLIN D and E is to drive progression through G1-phase, the cell cycle of ground state mouse ESCs does not depend on either one of them. Surprisingly, the combined depletion of Cyclin E1-2 and D1-3 does neither abrogate G1-phase progression nor successful S-phase entry in ground state ESCs . InteresNot only the cyclins but also their catalytically active partners have been functionally linked to regulation of gene expression in embryonic stem cells and during lineage specification. Similar to CYCLIN D and E the CDKs that promote progression through the G1-phase, CDK2 and CDK4, are dispensable during embryonic development until midgestation indicating that they are not required for the cell cycle of undifferentiated cells of the ICM. The loss of CDK1 on the other hand abrogates the first cell division upon conception and is considered to be the only CDK essential for undifferentiated cells to proliferate (reviewed in ). The faSox2 gene resulting in differentiation of ESCs [Considering the role of CDKs in ESCs it seems evident that their naturally occurring counterparts have the opposite function. This assumption is underscored by a large body of literature that indicates that CDKi’s are upregulated upon differentiation (reviewed by ). Apart  of ESCs –87. PresAlthough these results imply that the expression of CDKi’s correlates with differentiation, two recent reports show that the picture is more complex and context dependent. Active Wnt signaling via TCF1 controls the expression of the Cdkn1a tumor suppressor locus, that encodes the cell cycle inhibitors P15, P16 and P19 resulting in decreased cell proliferation while leaving the expression of pluripotency genes unchanged . In a re−/− cells show diminished differentiation potential . These iewed by . In mouscolonies . On the colonies . These rcolonies , 88. Furcolonies . Notablycolonies . It remacolonies , 87. Whecolonies . Like thcolonies . How thecolonies . Only a colonies .−/− mice are viable and a debate on the role of P53 in embryonic development is still ongoing [If cells suffer from stressful conditions progression through the cell cycle can be temporarily halted during G1-phase. The pathways that are responsible for G1-arrest not only act in response to stress but have also been shown to mediate developmentally programmed cell senescence . P53is a ongoing . A large ongoing ). Upon D ongoing . Moreove ongoing . Moreove ongoing , 104 and ongoing . Recentl ongoing . These r ongoing .In contrast to the above-mentioned literature, a few studies have shown that P53 can also inhibit lineage commitment and contribute to an undifferentiated phenotype. Stress-induced P53 activity was shown to mediate the transcription of Wnt ligands that contribute to an undifferentiated phenotype . MoreoveEarly studies on ESC derived from the inner cell mass revealed an unusual short cell cycle structure that was subject to dramatic changes during cell fate specification , 110. ThOver the past decades, the unusual short G1-phase of in vitro cultured ESCs has been the subject of intense investigation. Although this has led to an increasing understanding of how pluripotency and the cell cycle are intertwined, the cell cycle dynamics, and in particular the duration of the G1-phase, during embryonic development in vivo has remained largely unexplored. As outlined above, the short G1-phase of in vitro cultured ESCs is driven by several signaling pathways that play pivotal roles in embryonic development. Whether these signaling pathways responsible for the rapid increase in cell number during the cleavage stage as well, and whether this is through shortening of the G1-phase, is yet to be determined. Future studies combining genetic engineering and live cell cycle reporters could address these fundamental questions in developmental biology.Besides the role of the shortened G1-phase during in vivo embryonic development the effect of the extremely short G1-phase on the genomic integrity of in vitro cultured ESCs remains another interesting avenue for future research. Several studies have indicated that the short G1-phase in ESCs cultured in serum-rich conditions compromises the G1-specific DNA damage checkpoints. The absence of such checkpoints may in turn affect the genomic integrity of in vitro cultured ESCs. Whether the abbreviated G1-phase impairs DNA damage repair in ESCs in vitro, and whether this results in the elevated accumulation of DNA damage is not entirely clear. In this light it would be interesting to assess whether ESCs grown in serum-free conditions, that have an elongated G1-phase, cope differently with DNA damage during G1-phase. These studies will shed light on how different culture conditions affect the accumulation of DNA damage and the genomic integrity of ESCs. The results might have important implications for the clinical application of ESCs, such as therapies aimed at using stem cells-derived cells to replace damaged tissue.


In the last decade, treatment for castration-resistant prostate cancer has changed markedly, impacting symptom control and longevity for patients. However, a large proportion of cases progress despite androgen deprivation therapy and chemotherapy, while still being fit enough for several more lines of treatment. Overstimulation of the androgen receptor (AR) activity is the main driver of this cancer. Targeting biological functions of the AR or its co-regulators has proven very effective in this disease and led to the development of several highly effective drugs targeting the AR signalling axis. Drugs such as enzalutamide demonstrated that the improvement in anti-tumour efficacy is closely correlated with an affinity for the AR and its activity and have established the paradigm that AR remains activity in aggressive disease. However, as importantly, key insights into mechanisms of resistance are guiding the development of the next generation of AR-targeted drugs. This review outlines the historical development of these highly specific agents, their mechanism of action in the context of defective AR activity, and explores the potential for the upcoming next-generation AR inhibitors (ARI) for prostate cancer by targeting the alternative domains of AR, rather than by the conventional ligand-binding domain approach. There is huge potential in these approaches to develop new drugs with high clinical activity and further improve the outlook for patients. Prostate cancer (PCa) is the most common cancer in men in the United Kingdom. It continues to be a highly significant issue and health burden affecting one in every six men during their lifetime, with around 50,000 new cases of the disease per year in total The main driver of the aggressive disease is the AR and its overstimulated, often constitutively active oncogenic signalling . Normal Three-dimensional crystal structures of the LBD and DBD of the AR protein have been solved, however the structure of the NTD is unknown, it is recognised to be intrinsically disordered, with its size and sequence varying greatly between nuclear hormone receptors. The NTD is primarily responsible for transcriptional activation functions and harbours activation function-1 (AF-1), which can be activated independently of the LBD. Within the AF-1 are two transactivation units (TAU), TAU-1 and TAU-5 that drive AR-dependent transcriptional activation. The DBD allows the AR to interact with DNA. It contains P-box and D-box structures that have two zinc finger motifs required for a stable interaction with specific DNA sites known as androgen response elements (AREs) within the chromatin. The DBD is highly conserved across nuclear hormone receptors, where alignment studies suggest a high overlap (at least 76%) between the AR-DBD and those of other nuclear hormone receptors Patients will follow a certain treatment pathway as the disease progresses. If the tumour is localised at diagnosis, surgical intervention is commonly used to remove the tumour mass or patients may be treated with radiation therapy to destroy the tumour, which may be more suitable for frailer patients. High intensity ultrasound (HIFU) and cryotherapy are also options. Patients with advanced disease extending outside of the prostatic capsule are often treated with androgen deprivation therapy (ADT) employing castration by either surgery While this hormone blockade is initially effective, many patients eventually progress to ARIs non-responsive disease termed castration-resistant prostate cancer (CRPC) characterised by individual or a combination of rising serum PSA levels and symptomatic/radiographic progression such as the formation of bone metastases. Despite the failure of ARI, most CRPC still relies on AR signalling as evident from the success of the next-generation of ARIs th Helical structure occurs within the LBD, and thus the AF-2 site is distorted. Consequently, interferences with transcriptional co-factor binding can occur, leading to transcriptional inhibition ARIs that target the LBD are the predominant form of anti-androgen therapy given to CRPC patients. They are competitive inhibitors of androgens that occupy the ligand-binding pocket and therefore block androgens from binding and activating the AR. X-ray crystal structures of AR-antagonist complexes suggest displacement of the 12Steroidal ARIs such as cyproterone acetate (CPA) , Nilutamide and Flutamide (Hydroxyflutamide is its active form) are first-generation, non-steroidal ARIs and competitive inhibitors of the AR , Apalutamide (ARN-509) and Darolutamide (ODM-201)  are more potent than first-generation inhibitors as they display greater binding affinity for the AR, less off-target effects and have additional novel mechanisms of blocking AR action. As well as blocking the binding of androgens to the LBD of the AR, these drugs inhibit nuclear translocation of the AR whilst also impairing its chromatin binding Enzalutamide showed such palpable results in the phase III AFFIRM trial, that the trial was stopped early since interim analysis determined that it was able to prolong survival of CRPC patients for five months compared to placebo. This trial determined the efficacy of Enzalutamide and safety in patients who had castrate levels of testosterone, failed with chemotherapy and had a progressive disease A new ARI Darolutamide was developed more recently to combat resistance mechanisms and other clinical manifestations that patients encountered with Enzalutamide and Apalutamide A receptors in the brain causing seizures and other central nervous system issues in some patients. Darolutamide has a low brain:plasma ratio in vivo and therefore is much less likely to cross the blood-brain-barrier A common problem with several previous ARIs is that the drugs can cross the blood-brain-barrier and inhibit the GABA5, 3β-hydroxyl moiety, which is also present in some testosterone derivatives , and therefore it is metabolised by the enzyme 3βHSD to Δ5A (D4A) 50 values vs Abiraterone. This therefore reduces ligand-activated AR signalling whilst also competitively antagonising the AR with comparable potency to Enzalutamide. D4A contains a 3-keto structure, similar to testosterone and DHT that allows for a modest affinity to the AR. These properties suggest that D4A is more potent than Abiraterone in vitro and in vivo and has potential as a promising clinical agent LBD-targeting ARIs dominate currently in the clinic intending to reduce AR signalling and thus curbing disease progression, but other approaches are also being exploited to curb the mechanisms of resistance to ARIs. Although not a direct ARI, Abiraterone acetate is commonly used in the clinic as a second-generation drug to reduce androgen levels in the blood, with Abiraterone being its active metabolite. Clinical trials involving Abiraterone administration in combination with second-generation LBD-antagonists or with ADT has also been assessed AR allow for the continued and overstimulated firing of the oncogenic AR signalling pathway.Following prolonged treatment with ARIs, oncogenic mutations in AR gene emerge allowing the AR to become activated despite ARIs based therapies. These “cis” resistance mechanisms such as AR LBD point mutations, AR gene/enhancer amplification and the formation of AR variants are summarised in AR gene sequence and therefore codons corresponding to amino acids can change Point mutations within the LBD of the AR often emerge due to treatment-induced selection pressure and are therefore uncommon in treatment-naive patients . NucleotAn example of this would be the mutation W742L, where the amino acid, tryptophan is changed to leucine at position 742  since its side chain is more flexible than the side chain of phenylalanine and thus the LBD can form an agonist conformation with Enzalutamide The treatment-emergent point mutations can also lead to AR promiscuity whereby the AR is activated by other non-androgenic ligands . The T87AR gene. The increased copy number of the AR gene leads to AR overexpression and increased AR protein levels  have emerged that can circumvent AR inhibition by conventional LBD-targeting ARIs. These AR-Vs lack some or all the LBD, with carboxy-terminal extensions replacing the LBD that are encoded by unique transcripts . The NTDOver 20 AR variants (AR-Vs) have been identified to co-express with wild-type AR in human prostate cancer cell lines, xenografts or clinical specimens AR. Alternative splicing occurs such that a different pre-mRNA sequence is included in the mature mRNA compared to the intended sequences  associates with the splicing factor SF2 but MALAT1 is regulated by suppressive androgen response element in the promoter and therefore AR antagonism  will increase MALAT1 expression and thus the SF2 splicing factor These truncated AR-Vs form due to alternative splicing and/or structural gene rearrangements of the equences  due to dequences  .AR that is commonly seen is a tandem duplication that causes the formation of variants (present in CWR22Rv1 cell line) AR exons and consequently synthesis of these cryptic exons is increased  have not only been linked to increased androgen synthesis but opposes Abiraterone suppression by Abiraterone, suggesting an important role of this enzyme as a key driver of CRPC progression In addition to the several “cis” mechanisms that cause gain-of-function mutations in the AR gene, it is now well established that the AR pathway can be stimulated within the tumours by the upregulation of androgen synthesis. 3β hydroxysteroid dehydrogenase (3βHSD1) an AR regulated enzyme, which catalyses the formation of extragonadal androgens within the tumours from adrenal precursors thus fuelling cancer progression Degradation of proteins is a natural manifestation, often directed at misfolded or unfolded proteins, but is also vital for the maintenance of cellular function. This is usually carried out via the process of ubiquitination of the protein in question and consequent degradation by the proteasome Niclosamide  is an FDA-approved anthelmintic drug, used to treat tapeworm infections that have recently shown to mediate solely AR-V7 protein degradation via the proteasome-dependent pathway (the exact mechanism has not been reported) Two-Phase I clinical trials are currently ongoing to assess dosing and tolerability of Niclosamide treatment when in combination with Enzalutamide for CRPC patients in vitro and in vivoASC-J9 or Dimethylcurcumin in vitro and in vivo, reducing the proliferation of cells and growth of tumours UT-34  was namein vitro has demonstrated efficient degradation of the AR protein by 95% and can inhibit cell viability with 100 times more potency than AR LBD antagonists. Furthermore, single doses of the compound were able to reduce AR protein levels in vivo .Proteolysis targeting chimaeras (PROTACs) are a promising, new agent class that can be employed to degrade the AR. PROTACs are hetero-bifunctional small molecules and structurally are made up of an AR binder/antagonist joined to an E3 ubiquitin ligase ligand via a linker With the NTD being critical for the transcriptional activity of the AR, inhibiting this part of the AR protein would be predicted to block AR activity regardless of the presence or absence of the LBD, and thus such inhibitors will have the potential to treat all AR-Vs since all functional AR isoforms rely on a functional NTD. It remains a challenge to create specific inhibitors for the NTD because of its intrinsically disordered nature and thus undetermined 3D structure and therefore current NTD inhibitors are often discovered using compound screening libraries.In vitro studies have shown EPI reduces the chromatin binding of AR thus decreasing transactivation, leading to growth inhibition. Furthermore, it has also shown to block the N/C interdomain interaction of the full-length AR and disrupt protein-protein interactions of the AR with factors that aid the stabilisation of the N/C interaction. However, it does not competitively prevent ligands binding to the LBD as it solely interacts with the NTD. Moreover, it blocks interactions between the AR and transcriptional cofactors such as CREB-binding protein and RAP74 Epoxide based EPI-001  and its Data first suggested that EPI interacts with the AF-1 domain of the NTD by direct binding and creating conformational change in the AR polypeptide. Further studies then showed that EPI reversibly interacted with TAU-5, in which EPI forms a reversible complex with a precise conformation of AF-1 which allows for nucleophilic attack by a protein side-chain on the C-Cl bond of EPI, thus forming an adduct incapable of activating transcription 50 to Bicalutamide and Darolutamide so can be administered at similar doses. EPI-7386 has shown to be effective in prostate tumour models driven by wild-type, mutant and AR-Vs and continues to inhibit transactivation EPI-001 showed to be non-specific to the AR, however, where it inhibited the growth of AR-negative prostate cancer cell lines as well as in a breast carcinoma cell line where it modulated both oestrogen and progesterone receptors Dysidea sp. family that antagonise and uniquely bind the AF-1 domain of the NTD Sintokamides  are polyin vitro and in vivo models that are driven by full-length AR and AR-Vs significantly better than EPI-001 A recent study showed QW-07 to be another compound that blocks the transcriptional activity of the NTD . It can in vitroin vivo remains be determined.Another approach in targeting the NTD is the use of monoclonal antibodies. These antibodies are often used to bind cell surface antigens or extracellular molecules since they cannot penetrate the cell membrane and flag them for degradation by the immune system. mAb 3E10, derived from an anti-DNA autoantibody from lupus nephritis-infected mice, however, can penetrate mammalian cells rapidly and its uptake is dependent on ENT2, a nucleotide salvage receptor. Bispecific antibodies to target the NTD were developed using 3E10 as a scaffold and combining single-chain variable fragments (scFv) additions joined by linkers. AR441  , a cyaniFurther results suggest that PP only interacts with the AR DBD once the AR is bound to DNA. While PP does not stop the AR nuclear localisation or binding to DNA, it can prevent RNA polymerase II recruitment causing transcriptional repression in vitro models of CRPC leading to suppression of growth in vivo CRPC model, VPC-14449 treatment reduced tumour size and repressed PSA synthesis FASN, FKBP5 and TSC2), whilst it was only able to block recruitment for FASN and FKBP5, but not the TSC2 gene in an AR-V model in vivo however, demonstrated that a higher dose of VPC was required to elicit an effect and therefore metabolic stability needs to be further explored A group of compounds were discovered to be solely selective to the AR DBD (as opposed to other NRs) such that AR signalling is inhibited. VPC compounds , and a Prostate Cancer Foundation (USA) young investigator Award (M.A).Not applicableNot applicableAll authors declared that there are no conflicts of interest.


Parkinson’s disease (PD) is primarily defined by motor symptoms and is associated with alterations of sensorimotor areas. Evidence for network changes of the sensorimotor network (SMN) in PD is inconsistent and a systematic evaluation of SMN in PD yet missing. We investigate functional connectivity changes of the SMN in PD, both, within the network, and to other large-scale connectivity networks.Resting-state fMRI was assessed in 38 PD patients under long-term dopaminergic treatment and 43 matched healthy controls (HC). Independent component analysis (ICA) into 20 components was conducted and the SMN was identified within the resulting networks. Functional connectivity within the SMN was analyzed using a dual regression approach. Connectivity between the SMN and the other networks from group ICA was investigated with FSLNets. We investigated for functional connectivity changes between patients and controls as well as between medication states (OFF vs. ON) in PD and for correlations with clinical parameters.There was decreased functional connectivity within the SMN in left inferior parietal and primary somatosensory cortex in PD OFF. Across networks, connectivity between SMN and two motor networks as well as two visual networks was diminished in PD OFF. All connectivity decreases partially normalized in PD ON.PD is accompanied by functional connectivity losses of the SMN, both, within the network and in interaction to other networks. The connectivity changes in short- and long-range connections are probably related to impaired sensory integration for motor function in PD. SMN decoupling can be partially compensated by dopaminergic therapy.The online version contains supplementary material available at 10.1007/s00234-021-02731-w. Parkinson’s disease (PD) is one of the most common neurodegenerative diseases and is primarily defined by its motor symptoms comprising the classical clinical triad of bradykinesia, rigidity, and tremor. Loss of dopaminergic neurons within the substantia nigra pars compacta is regarded as the primary pathological hallmark of the disease and the resulting destabilization of basal ganglia circuits following nigrostriatal dopamine depletion is thought to be the main cause of deficits in motor control in PD. However, pathophysiological changes in PD clearly exceed the level of the basal ganglia yielding extensive alterations of cortico-striatal and cortico-cortical connections as a consequence of complex neurochemical imbalances , 2.In recent years, advanced neuroimaging techniques could strongly contribute to capture these changes in functional connections associated with PD and promoted a rapid progress in the deeper understanding of the disease . One of Research on FC has highlighted that the brain is intrinsically organized into distinct large-scale connectivity networks, which facilitate human brain function by their dynamic interplay , 7. EachThe SMN integrates primary sensorimotor, premotor and supplementary motor areas (SMA) to facilitate voluntary movements Fig. . Its intThe current study investigates the within- and across-network connectivity of the SMN in PD patients under long-term dopaminergic treatment based on independent component analysis (ICA) of resting-state fMRI and tests for disease-related connectivity changes as well as the effect of dopaminergic medication.2-test for gender, all p > 0.1). All patients were examined by an experienced movement disorders specialist. Diagnosis of idiopathic PD was based on the UK Parkinson’s Disease Society Brain Bank Clinical Diagnostic Criteria [Thirty-eight patients from the Center for Movement Disorders and Neuromodulation at the University Hospital Düsseldorf diagnosed with idiopathic PD and 43 healthy controls (HC) without any record of neurological or psychiatric disorders were included in the current analysis. PD patients and HC were matched for age, gender, and within-scanner head movement. Subjects were selected from an existing pool of 82 PD patients and 78 HC by determining the largest subsample from all subjects with complete and sufficient imaging data and no exclusion criteria, so that age, gender, and motion parameters from EPI motion correction did not differ significantly between patients and HC  were excluded prior to the matching procedure.Demographic and clinical characteristics of the sample are given in Table 2 axial plane, slices = 36, voxel size = 3.1 × 3.1 × 3.1 mm3). Patients were instructed to keep their eyes closed and let their mind flow without thinking at anything particular. T1-weighted structural MRI scans were acquired using a three-dimensional magnetization prepared rapid gradient-echo sequence .Resting-state fMRI was acquired using an echo-planar imaging (EPI) sequence covering the whole brain over a time period of 11 min on a 3 T Siemens Trio  to obtain blood oxygen level-dependent (BOLD) time series  Software Library (FSL) version 5.0 .The first five images of fMRI time series were discarded to account for magnetic saturation effects. EPI volumes were then motion corrected and slice timing correction was conducted. The six rigid-body parameter time series yielded from motion correction were used for later EPI signal denoising, and mean relative RMS displacement was used for group matching (see above). Motion-corrected fMRI volumes as well as structural MRIs were then brain extracted with FMRIB’s Brain Extraction Tool . EPIs weIntrinsic connectivity networks were derived from probabilistic ICA of the fMRI data of healthy controls using FMRIB’s Multivariate Exploratory Linear Optimized Decomposition into Independent Components (MELODIC) . For thiFC alterations between PD patients and HC within the SMN were evaluated using a dual regression approach , 26. In Brain regions resulting from intra-network connectivity analyses were anatomically allocated to probabilistic cytoarchitectonic maps using JuBrain, the Jülich brain Atlas , as implhttps://fsl.fmrib.ox.ac.uk/fsl/fslwiki/FSLNets) in MATLAB . For this, the normalized subject-specific time series obtained from the first step of dual regression for the SMN and the 17 remaining components resulting from group ICA were used as input for FSLNets. For all subjects, Pearson correlation coefficients between the time series of the SMN and each of the other 17 networks were calculated and transformed into Fisher’s z-scores. Group comparisons and correlation analyses were performed on these connectivity z-scores using the same GLM designs as for the intra-network analyses (see above) and applying permutation testing (5000 permutations). Resulting inter-network correlations were considered significant at a p < 0.05 threshold, FWE corrected for multiple comparisons.Inter-network FC alterations of the SMN, i.e., connectivity changes between the SMN and other intrinsic connectivity networks, were analyzed using the FSLNets package  as well as to the early visual network (IC14) was also found for PD ON compared to HC. Furthermore, there was a significantly lower FC between SMN and the dorsal visual/superior parietal network (IC9) in PD OFF compared to PD ON.When quantifying the SMN inter-network FC of these altered networks, the decreased connectivity in PD OFF (compared to HC) increased in PD ON for all four networks without reaching the FC strength of HC.There was a significant negative correlation of disease duration with connectivity between SMN and the motor/prefrontal network (IC7) in PD OFF. For PD ON, disease duration showed a significant negative correlation with SMN connectivity with the dorsal visual/superior parietal network (IC9), the right fronto-parietal network (IC4), a language associated network (IC15), and a component consisting of the salience, basal ganglia, and auditory networks (IC3). We found significant negative correlation for UPDRS-III improvement with SMN connectivity with the right fronto-parietal network (IC4) and for UPDRS-III score determined in medical OFF with SMN connectivity with the motor/prefrontal network (IC7) for patients in medical ON. There were no further significant correlations with SMN inter-network connectivity.The current study investigates sensorimotor FC changes related to PD in a sample of patients under long-term dopaminergic treatment using a network-based resting-state fMRI approach. Our results indicate that the SMN is affected by the disease showing alterations, both, within the network and in interaction with other large-scale connectivity networks. All connectivity changes within the SMN and across networks observed in the medical OFF condition of PD patients partially normalized in medical ON pointing to a direct alleviating effect of dopaminergic treatment on PD-related impairment of SMN network integrity.Dysfunction of sensorimotor regions is typically ascribed to denervation along the cortico-striatal pathway following nigrostriatal dopaminergic loss , 39. AmoOur findings highlight the importance of impaired network connections in the pathophysiology of PD. Within- and across-network alterations revealed by our study indicate that the disease clearly manifests and advances on a network basis and affects, both, the short-range and long-range connections of cortical sensorimotor areas. Overall, the changes observed between the SMN and other intrinsic connectivity networks are more pronounced than the within-network connectivity changes in our study. This is in line with previous studies investigating within-network as well as network-to-network connections in PD . ImpairmThe SMN comprises the primary sensorimotor cortex as well as areas involved in motor task preparation, such as the premotor cortex and the SMA, and is activated in tasks of voluntary movements , 11. DecThe main targets of within-network connectivity alterations found by our study are the left IPL and primary somatosensory cortex showing significant group differences. The IPL is implicated in several neurocognitive functions such as motor control, particularly of visually guided movements, (visuo-) spatial and non-spatial attention –55. The Area OP1 of the parietal operculum represents the secondary somatosensory cortex in humans and also facilitates somatosensory integration for motor function , 61. TheBeside the two motor-related networks, across-network connectivity analysis revealed disconnections of the SMN from networks of the visual system, i.e., from an early visual network and a dorsal visual/superior parietal network. The first network comprises visual areas of the ventral and dorsal visual stream , where tOur results are consistent with existing literature, which in the majority show decreased FC of the SMN. Using a graph-theoretical approach on resting-state FC data of non-demented PD patients, Gratton et al. showed that among all tested networks the SMN showed the greatest alterations between PD patients and controls . LikewisThe current study entails some limitations. First, the included sample of PD patients is rather heterogeneous in regard to disease stage, duration, and symptom severity. It would be conceivable that functional connectivity changes of the SMN vary across the course of the disease or show distinctions between different motor types. However, we would argue that the heterogeneity in our sample increases the variability of connectivity alterations across the whole spectrum of the disease within the patient group and thereby should make the observability of significant effects less probable. This makes the observed changes in our study more robust and generalizable. Nevertheless, the current results may provide a substantial basis for further investigations on more selected samples of PD patients and to reproduce the current findings in different populations.Likewise, medication schemes varied across included patients, as each patient received an individual dopaminergic medication plan resulting from individual optimization of treatment. Again, in our eyes, this diversity in medication protocols increases variability across the sample and makes the observed connectivity alterations and dopaminergic effects more robust and independent of specific drugs. In order to make antiparkinsonian treatment plans comparable, we calculated the LED according to Tomlinson et al.  and usedWe examined PD patients in a medication OFF phase at least 12 h after withdrawal of all dopaminergic drugs. This approach is quite common to investigate patients under long-term medical treatment in a “drug-free” condition. However, we cannot exclude that residual medication effects from dopamine agonists or long-acting forms of dopamine remain after 12 h. Furthermore, FC alterations seen in medical OFF and medical ON may possibly be not attributable to disease-specific effects alone, but could in part be induced by long-term effects of dopaminergic treatment.Patients were not systematically counterbalanced regarding the sequence of their scans, i.e., if they first underwent MRI examination in medical ON or OFF. We would not assume that the order of scans affects functional connectivity, but cannot rule out a sequence bias effect.The choice to split the fMRI signal into 20 independent components in ICA is quite arbitrary. We applied elaborate preprocessing of the fMRI data including an ICA-based signal denoising method (FSL FIX), which makes the resulting preprocessed fMRI signal very clean from residual noise. Parcellations resulting from group-level ICA on such data almost exclusively entail components with neuronal signal and no noise components , and theIn summary, PD is associated with extensive network changes of the SMN affecting its short- and long-range connections. These decouplings are probably associated with impaired sensorimotor integration in the disease. Several inter-network changes of the SMN are progressing with disease duration but seem rather independent of motor severity. Dopaminergic therapy can partially restore functional connections within the SMN and across networks, which may probably contribute to alleviation of neurological symptoms.ESM 1(PNG 600 kb)High Resolution (TIF 1441 kb)