Assessment of infant gonadal dose irradiated from urine-contaminated diapers during diuretic renal scintigraphy.

OBJECTIVE: To estimate the gonadal doses irradiated from urine- contaminated diapers during diuretic renal scintigraphy. METHODS: Images of 31 patients (18 males and 13 females) with urine-contaminated diapers during 99m Tc-MAG3 renal scintigraphy were analyzed. The count rate of the diapers was converted into a time-activity curve based on the calibrated factor of the gamma camera system. The cumulative activity was determined from the area under the curve. By incorporating dose per unit cumulative activity pre-calculated from Monte Carlo simulation with 0-year phantom, the gonadal dose irradiated from diaper was calculated. To assess the degree of this additionally introduced dose from diapers, the calculated gonadal dose was compared to the internal gonadal dose from injected radiotracer activity. RESULTS: The cumulative activities irradiated from urine-contaminated diapers were 1.12 E04 ±â€…1.29E04 MBq.s in male infants, which was nearly half of the 1.94 E04 ±â€…1.80E04 MBq.s ( P  = 0.15) in female infants. However, the absorbed doses for testes in male infants were 7.37E-01 ±â€…8.50E-01 mGy, which was approximately 10 times the 6.38E-02 ±â€…5.94E-02 mGy for ovaries in female infants ( P  < 0.01). The diaper-introduced dose for testes and ovaries was 91.7% and 3.9% of the gonadal doses from the injected activity in patients with normal renal function, and 99.0% and 4.3% of those in patients with abnormal renal function. CONCLUSION: Urine-contaminated diapers introduced additional radiation doses to infant patients during 99m Tc-MAG3 renal scintigraphy. The gonadal doses were of significance in male infants who had nearly double the absorbed dose for the testes.

Left Ventricular Mass Index in End-Stage Renal Disease Patients during Hemodialysis and Continuous Ambulatory Peritoneal Dialysis.

Background: One of the primary reasons for high mortality in end-stage renal disease (ESRD) is cardiovascular disease in patients with renal replacement therapy (RRT). Left ventricular hypertrophy (LVH) significantly predicts mortality and cardiovascular events. Objectives: We assess the left ventricular mass index change in two dialysis methods: hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). The factors associated with increased left ventricular mass index (LVMI). Materials and Methods: We recruit more than 50 HD patients and 45 CAPD patients with LVH of similar age, gender, dialysis duration, and LVMI for one-year follow-up. Results: The LVMI in the group of HD patients after one year increased from 180.28 ± 45.32 g/m2 to 212.58 ± 66.22 g/m2 (p = 0.001), while the LVMI in the group of patients with CAPD increased from 190.16 ± 66.01 g/m2 to 197.42 ± 78 g/m2 (p = 0.32). Multivariable logistic regression analysis, we demonstrated that dialysis by HD (ß = -1,167, 95% CI: 0.104-0.938, p = 0.036) and anemia treatment lower the goals (ß = 1.9566, 95% CI: 1.466-34.094, p = 0.015) were two factors associated with the progression of the LVMI. Conclusion: The LVH of end-stage renal disease patients with HD treatment is worse than CAPD treatment after a follow-up in one year. Dialysis by periodic hemodialysis and anemia treatment that fails to achieve the goal are risk factors associated with increased progression of LVMI in patients with ESRD.

Accuracy of Subthalamic Nucleus Electrode Implantation in Deep Brain Stimulation Surgery for Parkinson's Disease Treatment and Affecting Factors: Outcomes at Two Centers in Vietnam.

BACKGROUND: Deep brain stimulation (DBS) surgery for Parkinson's Disease (PD) has become more and more popular in Vietnam. However, the accuracy of implantation and affecting factors are under investigation. The objective of this study is to evaluate the accuracy of the subthalamic nucleus (STN)-DBS electrode implantation technique for treatment PD at Nguyen Tri Phuong Hospital and University Medical Center. To investigate factors related to accuracy. METHODS: We carried out a retrospective analysis of 58 patients with advanced PD who underwent STN-DBS surgery at Nguyen Tri Phuong Hospital and University Medical Center in Ho Chi Minh City, Viet Nam between June 2014 and July 2021 (115 leads total). All patients underwent the procedure with standard frame-based techniques under local anesthesia with microelectrode recording and macrostimuation test. RESULTS: Twenty-six female (44.8%) and thirty-two male (55.2%) patients with a mean age of 60.4 ± 8.3 years old (40-76 years) were included. Of total of 115 electrodes implanted, the mean target error (ΔT), radial error (ΔR), angle error (Δθ) were 1.94 ± 0.73 mm; 1.16 ± 0.69 mm; 2.22 ± 4.24 degrees, respectively. Vector error on each coordinate axis ΔX, ΔY, ΔZ were -0.35 ± 1.02 mm, +0.99 ± 0.82 mm, +0.73 ± 0.99 mm, respectively. There was a statistically significant correlation between subdural air volume, cortical shift, intracranial electrode bending, and accuracy. CONCLUSIONS: The current STN-DBS electrode implantation technique applied in our centers was quite accurate with acceptable error. More clinical trials are necessary to directly compare affecting factors to the accuracy of electrode implantation.

Mesenchymal Stromal Cells Facilitate Tip Cell Fusion Downstream of BMP-Mediated Venous Angiogenesis-Brief Report.

BACKGROUND: The goal of this study was to identify and characterize cell-cell interactions that facilitate endothelial tip cell fusion downstream of BMP (bone morphogenic protein)-mediated venous plexus formation. METHODS: High resolution and time-lapse imaging of transgenic reporter lines and loss-of-function studies were carried out to study the involvement of mesenchymal stromal cells during venous angiogenesis. RESULTS: BMP-responsive stromal cells facilitate timely and precise fusion of venous tip cells during developmental angiogenesis. CONCLUSIONS: Stromal cells are required for anastomosis of venous tip cells in the embryonic caudal hematopoietic tissue.

Does High-Intensity Exercise Cause Acute Liver Injury in Patients with Fontan Circulation? A Prospective Pilot Study.

The Fontan procedure results in chronic hepatic congestion and Fontan-associated liver disease (FALD) characterized by progressive liver fibrosis and cirrhosis. Exercise is recommended in this population, but may accelerate the progression of FALD from abrupt elevations in central venous pressure. The aim of this study was to assess if acute liver injury occurs after high-intensity exercise in patients with Fontan physiology. Ten patients were enrolled. Nine had normal systolic ventricular function and one had an ejection fraction < 40%. During cardiopulmonary exercise testing, patients had near-infrared spectroscopy (NIRS) to measure oxygen saturation of multiple organs, including the liver, and underwent pre- and post-exercise testing with liver elastography, laboratory markers, and cytokines to assess liver injury. The hepatic and renal NIRS showed a statistically significant decrease in oxygenation during exercise, and the hepatic NIRS had the slowest recovery compared to renal, cerebral, and peripheral muscle NIRS. A clinically significant increase in shear wave velocity occurred after exercise testing only in the one patient with systolic dysfunction. There was a statistically significant, albeit trivial, increase in ALT and GGT after exercise. Fibrogenic cytokines traditionally associated with FALD did not increase significantly in our cohort; however, pro-inflammatory cytokines that predispose to fibrogenesis did significantly rise during exercise. Although patients with Fontan circulation demonstrated a significant reduction in hepatic tissue oxygenation based on NIRS saturations during exercise, there was no clinical evidence of acute increase in liver congestion or acute liver injury following high-intensity exercise.

BeCaked: An Explainable Artificial Intelligence Model for COVID-19 Forecasting.

From the end of 2019, one of the most serious and largest spread pandemics occurred in Wuhan (China) named Coronavirus (COVID-19). As reported by the World Health Organization, there are currently more than 100 million infectious cases with an average mortality rate of about five percent all over the world. To avoid serious consequences on people's lives and the economy, policies and actions need to be suitably made in time. To do that, the authorities need to know the future trend in the development process of this pandemic. This is the reason why forecasting models play an important role in controlling the pandemic situation. However, the behavior of this pandemic is extremely complicated and difficult to be analyzed, so that an effective model is not only considered on accurate forecasting results but also the explainable capability for human experts to take action pro-actively. With the recent advancement of Artificial Intelligence (AI) techniques, the emerging Deep Learning (DL) models have been proving highly effective when forecasting this pandemic future from the huge historical data. However, the main weakness of DL models is lacking the explanation capabilities. To overcome this limitation, we introduce a novel combination of the Susceptible-Infectious-Recovered-Deceased (SIRD) compartmental model and Variational Autoencoder (VAE) neural network known as BeCaked. With pandemic data provided by the Johns Hopkins University Center for Systems Science and Engineering, our model achieves 0.98 [Formula: see text] and 0.012 MAPE at world level with 31-step forecast and up to 0.99 [Formula: see text] and 0.0026 MAPE at country level with 15-step forecast on predicting daily infectious cases. Not only enjoying high accuracy, but BeCaked also offers useful justifications for its results based on the parameters of the SIRD model. Therefore, BeCaked can be used as a reference for authorities or medical experts to make on time right decisions.

Technical note: Evaluation of a V-Net autosegmentation algorithm for pediatric CT scans: Performance, generalizability, and application to patient-specific CT dosimetry.

PURPOSE: This study developed and evaluated a fully convolutional network (FCN) for pediatric CT organ segmentation and investigated the generalizability of the FCN across image heterogeneities such as CT scanner model protocols and patient age. We also evaluated the autosegmentation models as part of a software tool for patient-specific CT dose estimation. METHODS: A collection of 359 pediatric CT datasets with expert organ contours were used for model development and evaluation. Autosegmentation models were trained for each organ using a modified FCN 3D V-Net. An independent test set of 60 patients was withheld for testing. To evaluate the impact of CT scanner model protocol and patient age heterogeneities, separate models were trained using a subset of scanner model protocols and pediatric age groups. Train and test sets were split to answer questions about the generalizability of pediatric FCN autosegmentation models to unseen age groups and scanner model protocols, as well as the merit of scanner model protocol or age-group-specific models. Finally, the organ contours resulting from the autosegmentation models were applied to patient-specific dose maps to evaluate the impact of segmentation errors on organ dose estimation. RESULTS: Results demonstrate that the autosegmentation models generalize to CT scanner acquisition and reconstruction methods which were not present in the training dataset. While models are not equally generalizable across age groups, age-group-specific models do not hold any advantage over combining heterogeneous age groups into a single training set. Dice similarity coefficient (DSC) and mean surface distance results are presented for 19 organ structures, for example, median DSC of 0.52 (duodenum), 0.74 (pancreas), 0.92 (stomach), and 0.96 (heart). The FCN models achieve a mean dose error within 5% of expert segmentations for all 19 organs except for the spinal canal, where the mean error was 6.31%. CONCLUSIONS: Overall, these results are promising for the adoption of FCN autosegmentation models for pediatric CT, including applications for patient-specific CT dose estimation.

Pediatric chest-abdomen-pelvis and abdomen-pelvis CT images with expert organ contours.

PURPOSE: Organ autosegmentation efforts to date have largely been focused on adult populations, due to limited availability of pediatric training data. Pediatric patients may present additional challenges for organ segmentation. This paper describes a dataset of 359 pediatric chest-abdomen-pelvis and abdomen-pelvis Computed Tomography (CT) images with expert contours of up to 29 anatomical organ structures to aid in the evaluation and development of autosegmentation algorithms for pediatric CT imaging. ACQUISITION AND VALIDATION METHODS: The dataset collection consists of axial CT images in Digital Imaging and Communications in Medicine (DICOM) format of 180 male and 179 female pediatric chest-abdomen-pelvis or abdomen-pelvis exams acquired from one of three CT scanners at Children's Wisconsin. The datasets represent random pediatric cases based upon routine clinical indications. Subjects ranged in age from 5 days to 16 years, with a mean age of 7 years. The CT acquisition, contrast, and reconstruction protocols varied across the scanner models and patients, with specifications available in the DICOM headers. Expert contours were manually labeled for up to 29 organ structures per subject. Not all contours are available for all subjects, due to limited field of view or unreliable contouring due to high noise. DATA FORMAT AND USAGE NOTES: The data are available on The Cancer Imaging Archive (TCIA_ (https://www.cancerimagingarchive.net/) under the collection Pediatric-CT-SEG. The axial CT image slices for each subject are available in DICOM format. The expert contours are stored in a single DICOM RTSTRUCT file for each subject. The contour names are listed in Table 2. POTENTIAL APPLICATIONS: This dataset will enable the evaluation and development of organ autosegmentation algorithms for pediatric populations, which exhibit variations in organ shape and size across age. Automated organ segmentation from CT images has numerous applications including radiation therapy, diagnostic tasks, surgical planning, and patient-specific organ dose estimation.

Nonuniqueness of hydrodynamic dispersion revealed using fast 4D synchrotron x-ray imaging.

Experimental and field studies reported a significant discrepancy between the cleanup and contamination time scales, while its cause is not yet addressed. Using high-resolution fast synchrotron x-ray computed tomography, we characterized the solute transport in a fully saturated sand packing for both contamination and cleanup processes at similar hydrodynamic conditions. The discrepancy in the time scales has been demonstrated by the nonuniqueness of hydrodynamic dispersion coefficient versus injection rate (Péclet number). Observations show that in the mixed advection-diffusion regime, the hydrodynamic dispersion coefficient of cleanup is significantly larger than that of the contamination process. This nonuniqueness has been attributed to the concentration-dependent diffusion coefficient during the cocurrent and countercurrent advection and diffusion, present in contamination and cleanup processes. The new findings enhance our fundamental understanding of transport processes and improve our capability to estimate the transport time scales of chemicals or pollution in geological and engineering systems.

Development of Fe3O4 core-TiO2 shell nanocomposites and nanoconjugates as a foundation for neuroblastoma radiosensitization.

BACKGROUND: Neuroblastoma is the most common extracranial solid malignancy in childhood which, despite the current progress in radiotherapy and chemotherapy protocols, still has a high mortality rate in high risk tumors. Nanomedicine offers exciting and unexploited opportunities to overcome the shortcomings of conventional medicine. The photocatalytic properties of Fe3O4 core-TiO2 shell nanocomposites and their potential for cell specific targeting suggest that nanoconstructs produced using Fe3O4 core-TiO2 shell nanocomposites could be used to enhance radiation effects in neuroblastoma. In this study, we evaluated bare, metaiodobenzylguanidine (MIBG) and 3,4-Dihydroxyphenylacetic acid (DOPAC) coated Fe3O4@TiO2 as potential radiosensitizers for neuroblastoma in vitro. RESULTS: The uptake of bare and MIBG coated nanocomposites modestly sensitized neuroblastoma cells to ionizing radiation. Conversely, cells exposed to DOPAC coated nanocomposites exhibited a five-fold enhanced sensitivity to radiation, increased numbers of radiation induced DNA double-strand breaks, and apoptotic cell death. The addition of a peptide mimic of the epidermal growth factor (EGF) to nanoconjugates coated with MIBG altered their intracellular distribution. Cryo X-ray fluorescence microscopy tomography of frozen hydrated cells treated with these nanoconjugates revealed cytoplasmic as well as nuclear distribution of the nanoconstructs. CONCLUSIONS: The intracellular distribution pattern of different nanoconjugates used in this study was different for different nanoconjugate surface molecules. Cells exposed to DOPAC covered nanoconjugates showed the smallest nanoconjugate uptake, with the most prominent pattern of large intracellular aggregates. Interestingly, cells treated with this nanoconjugate also showed the most pronounced radiosensitization effect in combination with the external beam x-ray irradiation. Further studies are necessary to evaluate mechanistic basis for this increased radiosensitization effect. Preliminary studies with the nanoparticles carrying an EGF mimicking peptide showed that this approach to targeting could perhaps be combined with a different approach to radiosensitization - use of nanoconjugates in combination with the radioactive iodine. Much additional work will be necessary in order to evaluate possible benefits of targeted nanoconjugates carrying radionuclides. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12645-021-00081-z.

Data processing methods and data acquisition for samples larger than the field of view in parallel-beam tomography.

Parallel-beam tomography systems at synchrotron facilities have limited field of view (FOV) determined by the available beam size and detector system coverage. Scanning the full size of samples bigger than the FOV requires various data acquisition schemes such as grid scan, 360-degree scan with offset center-of-rotation (COR), helical scan, or combinations of these schemes. Though straightforward to implement, these scanning techniques have not often been used due to the lack of software and methods to process such types of data in an easy and automated fashion. The ease of use and automation is critical at synchrotron facilities where using visual inspection in data processing steps such as image stitching, COR determination, or helical data conversion is impractical due to the large size of datasets. Here, we provide methods and their implementations in a Python package, named Algotom, for not only processing such data types but also with the highest quality possible. The efficiency and ease of use of these tools can help to extend applications of parallel-beam tomography systems.

Preliminary paleohistological observations of the StW 573 ('Little Foot') skull.

Numerous aspects of early hominin biology remain debated or simply unknown. However, recent developments in high-resolution imaging techniques have opened new avenues in the field of paleoanthropology. More specifically, X-ray synchrotron-based analytical imaging techniques have the potential to provide crucial details on the ontogeny, physiology, biomechanics, and biological identity of fossil specimens. Here we present preliminary results of our X-ray synchrotron-based investigation of the skull of the 3.67-million-year-old Australopithecus specimen StW 573 ('Little Foot') at the I12 beamline of the Diamond Light Source (United Kingdom). Besides showing fine details of the enamel (i.e., hypoplasias) and cementum (i.e., incremental lines), as well as of the cranial bone microarchitecture (e.g., diploic channels), our synchrotron-based investigation reveals for the first time the 3D spatial organization of the Haversian systems in the mandibular symphysis of an early hominin.

RhoA activation-mediated vascular permeability in capillary malformation-arteriovenous malformation syndrome: a hypothesis.

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a class of capillary anomalies that are associated with arteriovenous malformations and arteriovenous fistulas, which carry a risk of hemorrhages. There are no broadly effective pharmacological therapies currently available. Most CM-AVMs are associated with a loss of RASA1, resulting in constitutive activation of RAS signaling. However, protein interaction analysis revealed that RASA1 forms a complex with Rho GTPase-activating protein (RhoGAP), a negative regulator of RhoA signaling. Herein, we propose that loss of RASA1 function results in constitutive activation of RhoA signaling in endothelial cells, resulting in enhanced vascular permeability. Therefore, strategies aimed at curtailing RhoA activity should be tested as an adjunctive therapeutic approach in cell culture studies and animal models of RASA1 deficiency.

α-Conidendrin inhibits the expression of intercellular adhesion molecule-1 induced by tumor necrosis factor-α in human lung adenocarcinoma A549 cells.

α-Conidendrin is a lignan isolated from Taxus wallichiana and other species. In the present study, we demonstrated that α-conidendrin inhibited the cell-surface expression of intercellular adhesion molecule-1 (ICAM-1) induced by tumor necrosis factor-α (TNF-α) at an IC50 value of 40-60 µM in human lung adenocarcinoma A549 cells. α-Conidendrin decreased ICAM-1 protein and mRNA expression levels at concentrations of 40-100 µM in TNF-α-stimulated A549 cells. The TNF-α-induced mRNA expression of vascular cell adhesion molecule-1, E-selectin, and cyclooxygenase-2 was also reduced by α-conidendrin. In the TNF-α-induced nuclear factor κB (NF-κB) signaling pathway, α-conidendrin did not influence the translocation of the NF-κB subunit RelA from the cytoplasm to the nucleus at concentrations up to 100 µM. A chromatin immunoprecipitation assay revealed that α-conidendrin at 100 µM reduced the binding of RelA to the ICAM-1 promoter in response to a stimulation with TNF-α. Collectively, these results indicated that α-conidendrin interfered with the DNA binding of RelA to the ICAM-1 promoter, thereby reducing ICAM-1 transcription.

Clinical utilization of whole-body PET/MRI in childhood sarcoma.

Hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI) has emerged as a useful tool that combines the superior tissue contrast of MRI with the targeted functional imaging of PET. In the assessment of sarcomas in children, PET/MRI has the potential to serve as a single point of service, allowing superior anatomical imaging and evaluation of metabolic uptake during one imaging session. In this pictorial essay, we review our preliminary experience with PET/MRI in the evaluation of pediatric sarcoma. The limitations and contraindications of PET/MRI are also discussed.

Congenital right internal mammary artery to portal vein arteriovenous malformation.

Neonatal cases of systemic artery to portal venous system arteriovenous malformations (AVMs) can present unique challenges in terms of diagnosis, management, and treatment. Prompt identification of these AVMs is necessary for minimizing long-term sequelae and optimizing prognosis. Our report describes the diagnosis and successful endovascular coil embolization of a congenital right internal mammary artery (IMA) to portal vein AVM in a young infant initially presenting during routine fetal screening with an incidentally discovered congenital thoracic vascular abnormality.

Direct characterization of solute transport in unsaturated porous media using fast X-ray synchrotron microtomography.

Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 µm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (>50 TB) was produced, while imaging the evolution of the solute concentration with time at any given point within the field of view. We show that the fluids' topology has a critical signature on the non-Fickian transport, which yet needs to be included in the Darcy-scale solute transport models. The three-dimensional (3D) results show that the fully mixing assumption at the pore scale is not valid, and even after injection of several pore volumes the concentration field at the pore scale is not uniform. Additionally, results demonstrate that dispersivity is changing with saturation, being twofold larger at the saturation of 0.52 compared to that at the fully saturated domain.