A systematic review and meta-analysis of data linkage between motor vehicle crash and hospital-based datasets

Motor vehicle crash data linkage has emerged as a vital tool to better understand the injury outcomes and the factors contributing to crashes. This systematic review and meta-analysis aims to explore the existing knowledge on data linkage between motor vehicle crashes and hospital-based datasets, summarize and highlight the findings of previous studies, and identify gaps in research. A comprehensive and systematic search of the literature yielded 54 studies for a qualitative analysis, and 35 of which were also considered for a quantitative meta-analysis. Findings highlight a range of viable methodologies for linking datasets, including manual, deterministic, probabilistic, and integrative methods. Designing a linkage method that integrates different algorithms and techniques is more likely to result in higher match rate and fewer errors. Examining the results of the meta-analysis reveals that a wide range of linkage rates were reported. There are several factors beyond the approach that affect the linkage rate including the size and coverage of both datasets and the linkage variables. Gender, age, crash type, and roadway geometry at the crash site were likely to be associated with a record's presence in a linked dataset. Linkage rate alone is not the only important metric and when linkage rate is used as a metric in research, both police and hospital rates should be reported. This study also highlights the importance of examining and accounting for population and bias introduced by linking two datasets.

A critical review of municipal solid waste hydraulic conductivity: A mini review

This study is a critical review of municipal solid waste (MSW) hydraulic conductivity that includes investigation of the influence of vertical stress, dry unit weight and degradation. A total of 56 studies were compiled that included laboratory-, pilot- and landfill-scale hydraulic conductivity experiments. Compacting waste and increasing vertical stress reduce MSW hydraulic conductivity via reshaping the pore networks throughout the waste matrix, reducing the void ratio and increasing tortuosity. However, the magnitude of reduction in hydraulic conductivity is dependent on stress, waste composition and decomposition. Solid waste decomposition can have opposing effects on hydraulic conductivity. Some studies have indicated that an increase in MSW decomposition results in particle size reduction and settlement that reduces the void ratio and decreases hydraulic conductivity. Conversely, some studies indicate that waste decomposition reduces the solid mass, which increases the void ratio and creates larger flow paths that increase hydraulic conductivity. The data compilation, observations and key findings from this study are beneficial for solid waste practitioners to improve design, analysis and operation of MSW landfills.

The additive effect of intravitreal dexamethasone combined with bevacizumab in refractory diabetic macular edema

PURPOSE

To evaluate the short-term structural and visual outcomes and side effects associated with intravitreal dexamethasone (IVD) combined with bevacizumab (IVB) in treating patients with diabetic macular edema (DME) and an inadequate response to anti-vascular endothelial growth factor (anti-VEGF) agents.

METHODS

In this prospective interventional case series, a total of 81 eyes of 81 patients with type 2 diabetes mellitus (T2DM) and refractory DME were included and assigned to one of two groups: I) those receiving three monthly intravitreal injections of combined bevacizumab and dexamethasone (IVB+IVD) and II) those receiving three monthly intravitreal injections of bevacizumab alone (IVB). The primary outcome was the inter-group difference in central macular thickness (CMT); secondary outcomes included best-corrected visual acuity (BCVA), baseline optical coherence tomography (OCT) biomarkers, and intraocular pressure (IOP) one month after the last injection.

RESULTS

Reduction in CMT and improvement in BCVA were significantly greater in the IVB+IVD group than the IVB group (109.88±156.25 vs. 43±113.67, respectively, P=0.03; and -0.13±0.23 vs. -0.01±0.17, respectively, P=0.008). Presence of neurosensory retinal detachment (NSD) (P<0.001) and complete inner segment/outer segment junction (IS-OS) disruption (P=0.049) on baseline OCT scans were associated with further CMT reductions in response to IVD. Conversely, identifiable epiretinal membrane (ERM) (P=0.002) and multiple hyperreflective foci (>20) (P=0.049) were associated with smaller reductions in CMT. Vitreomacular traction correlated with worse visual outcomes in the IVB+IVD group (P=0.003). The intergroup IOP difference was not clinically significant.

CONCLUSION

In patients with refractory DME, addition of IVD to the standard IVB regimen can improve visual and structural outcomes without increasing the risk of endophthalmitis, IOP rise, or intraocular inflammation. Patients with NSD are more likely to respond well to IVD. The presence of ERM may predict poor treatment response.

Influence of oil and gas exploration and production waste on municipal solid waste hydraulic conductivity

This study evaluated the effects of addition of oil and gas exploration and production wastes (E&PW) on hydraulic behavior of municipal solid waste (MSW). A series of laboratory experiments were conducted to assess the impacts of vertical stress, waste composition, mixture ratio of MSW to E&PW based on total mass (e.g., 20% MSW + 80% E&PW), and mixing methods on hydraulic conductivity. Hydraulic conductivity (k) for MSW-E&PW mixtures with 20% and 40% E&PW contents reduced from 3 × 10^-5 m/s to 10^-7 m/s as vertical stress increased from 0 to 400 kPa. An increase in the mixture ratio above 60% resulted in an additional order-of-magnitude decrease in k to 10^-8 m/s as vertical stress increased above 200 kPa. The addition of E&PW did not impact the available flow path, even though adding E&PW to MSW reduced the void spaces. This indicated that the waste matrix is capable of accepting E&PW while keeping the flow structure within the waste matrix. However, for vertical stress greater than 50 kPa, mixtures of MSW + 80% E&PW were observed to yield hydraulic conductivity < 10^-9 m/s.

Tractable Maximum Likelihood Estimation for Latent Structure Influence Models with Applications to EEG & ECoG processing

Brain signals are nonlinear and nonstationary time series, which provide information about spatiotemporal patterns of electrical activity in the brain. CHMMs are suitable tools for modeling multi-channel time-series dependent on both time and space, but state-space parameters grow exponentially with the number of channels. To cope with this limitation, we consider the influence model as the interaction of hidden Markov chains called Latent Structure Influence Models (LSIMs). LSIMs are capable of detecting nonlinearity and nonstationarity, making them well suited for multi-channel brain signals. We apply LSIMs to capture the spatial and temporal dynamics in multi-channel EEG/ECoG signals. The current manuscript extends the scope of the re-estimation algorithm from HMMs to LSIMs. We prove that the re-estimation algorithm of LSIMs will converge to stationary points corresponding to Kullback-Leibler divergence. We prove convergence by developing a new auxiliary function using the influence model and a mixture of strictly log-concave or elliptically symmetric densities. The theories that support this proof are derived from previous studies by Baum, Liporace, Dempster, and Juang. We then develop a closed-form expression for re-estimation formulas using tractable marginal forward-backward parameters defined in our previous study. Simulated datasets and EEG/ECoG recordings confirm the practical convergence of the derived re-estimation formulas. We also study the use of LSIMs for modeling and classification on simulated and real EEG/ECoG datasets. Based on AIC and BIC, LSIMs perform better than HMMs and CHMMs in modeling embedded Lorenz systems and ECoG recordings. LSIMs are more reliable and better classifiers than HMMs, SVMs and CHMMs in 2-class simulated CHMMs. EEG biometric verification results indicate that the LSIM-based method improves the area under curve (AUC) values by about 6.8% and decreases the standard deviation of AUC values from 5.4% to 3.3% compared to the existing HMM-based method for all conditions on the BED dataset.

Acetazolamide and bevacizumab combination therapy versus bevacizumab monotherapy in macular edema secondary to retinal vein occlusion

PURPOSE

To determine and compare the efficacy of intravitreal bevacizumab (IVB) and oral acetazolamide (OA) combination therapy versus IVB monotherapy in patients with macular edema secondary to retinal vein occlusion (RVO).

METHODS

This randomized clinical trial included 54 eyes of 52 patients with RVO central macular thickness (CMT) of more than 300μm, and best corrected visual acuity (BCVA) between 20/400 and 20/40. Eligible patients were randomly assigned to two groups: (I) IVB and OA (250mg twice daily) combination therapy or (II) IVB monotherapy. Ocular injections were repeated monthly for up to three months; BCVA and CMT were measured monthly.

RESULTS

Both regimens resulted in significant reduction in CMT (534±150μm to 352±90μm in the IVB+OA group, P<0.001; and 580±175μm to 362±90μm in the IVB group, P<0.001); neither showed superiority in this regard. Likewise, BCVA showed significant improvement in both groups (0.87±0.56 to 0.53±0.28 LogMAR in the IVB+OA group, P=0.001; and 0.85±0.62 to 0.46±0.4 LogMAR in the IVB group, P<0.001), with no intergroup difference.

CONCLUSION

Addition of oral acetazolamide to IVB in eyes with macular edema secondary to RVO may not result in additional short-term benefits regarding functional and anatomical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05290948, registered on March 22, 2022. https://clinicaltrials.gov/ct2/show/NCT05290948.

Analysis of Root Cause of the Fatal Occupational Accidents in a Gas Refinery Using the Tripod-Beta Method

Introduction: Most critical accidents in different industries are observable, but their severity is also predictable and can be controlled. Provided that accident analysis is properly managed with a preventive approach and based on correct findings, in a principled and realistic manner, root causes, corrective actions, and safety measures regarding accidents are performed. Material and Methods: The present research was a descriptive-analytic study, and the reported and recorded fatal occupational accidents were analyzed in the onshore section of one of the construction refinery projects in the South Pars Gas Refinery over a decade using the Tripod Beta method and then main risk factors, pre-conditions, and underlying causes, as well as the existing protective barriers, were identified, and an accidents tree was drawn. Results: The analysis of fatal occupational accidents showed that 26 immediate causes, 39 preconditions, and 50 underlying causes were involved in those accidents. Six key risk factors include lack of responsibility/organizational impact (57.8%), training (22.2%), hardware or tools and equipment (6.7%), maintenance management (6.7%), work procedures (4.4%), and Error Enforcing conditions (2.2%) had the largest share of the occurrence of accidents.  Conclusion: More than 80% of fatal occupational accidents can be controlled by modifying the two main factors, responsibility and organization and training. Therefore, implementing the total productive maintenance method, effective monitoring of staff work, hiring staff with sufficient knowledge and skills, and improving training indicators will increase understanding of hazard sources, improve safety and reduce accidents.

A New Post-Processing Method using Latent Structure Influence Models for Channel Fusion in Automatic Sleep Staging

Human sleep stage dynamics can be adequately represented using Markov chain models, and the accuracy of sleep stage classification can be improved by considering these dynamics. The present study proposes a new post-processing method based on channel fusion using Latent Structure Influence Models (LSIMs). LSIMs can simultaneously model sequences of different channels to have a nonlinear dynamical fusion based on sleep stage dynamics. The proposed method develops and examines two channel-fusion algorithms: the standard LSIM fusion and the integrated LSIM fusion, in which the latter is more efficient and performs better. The proposed LSIM-based method simultaneously incorporates the nonlinear interactions between channels and the sleep stage dynamics. In the first step, existing sleep staging systems process every data channel independently and produce stage score sequences for each channel. These single-channel scores are then projected into belief space using the marginal one-slice parameter of all channels by LSIM fusion algorithms. The logarithms of marginal one-slice parameters are concatenated to obtain log-scale belief state space (LBSS) features in the standard LSIM fusion. In the integrated LSIM fusion, integrated LBSS (ILBSS) features are formed by combining the LBSS features of several LSIMs. Finally, a KNN classifier maps the LBSS and ILBSS features onto the sleep stages. By utilizing four recently developed sleep staging systems, the proposed method is applied to the publicly available SleepEDF-20 database that contains five AASM sleep stages (N1, N2, N3, REM, and W). Compared to single-channel (Fpz-Cz, Pz-Oz, and EOG) results, integrated LSIM fusion results have a statistically significant improvement of 1.5% in 2-channel fusion (Fpz-Cz and Pz-Oz) and 2.5% in 3-channel fusion (Fpz-Cz, Pz-Oz, and EOG). With an overall accuracy of 87.3% for 3-channel post-processing, the integrated LSIM fusion system offers one of the highest overall accuracy rates among existing studies.

Implications of municipal solid waste co-disposal experiments on biodegradation and biochemical compatibility

The objective of this study was to evaluate waste biodegradation and biochemical compatibility for different waste co-disposed with municipal solid waste (MSW). Laboratory-scale reactors were operated with MSW co-disposed with special solid waste, liquid waste, or sludge waste. Early and aggressive addition of liquid wastes during reactor startup did not stimulate anaerobic decomposition of fresh MSW. The majority of the liquid waste reactors were acid stuck and had leachate pH < 6 and chemical oxygen demand in the range of 50,000 mg-O₂/L. The majority of liquid wastes in this study were not observed to be effective anaerobic inoculums and would not be recommended as the sole moisture source for bioreactor landfills. Enhanced early methane production was observed in the MSW reactors co-disposed with sludge (anaerobic and industrial) relative to the landfill leachate control reactors and all other waste combinations evaluated. Methane generation was observed in reactors operated with foundry waste or gypsum board co-disposed with MSW. Despite biochemical methane potential (BMP) results that indicated methane generation would be inhibited with these two waste streams, co-disposing with MSW did not completely inhibit anaerobic degradation. The BMP assays provided methane yield under ideal conditions, but did not capture other benefits of co-disposal (e.g., impacts of moisture addition). A potential co-disposal waste source should not be ruled out by BMP results alone.

Modelling bus-pedestrian crash severity in the state of Victoria, Australia

Understanding the relationship between bus-pedestrian crash severity and factors contributing to such crashes is important. However, there exists a dearth of research on the factors affecting bus-pedestrian crash severity. This study aims to fulfil this gap by investigating the factors affecting the severity of pedestrian injuries. A data set of bus-pedestrian crashes in the State of Victoria, Australia was analysed over the period of 2006 - 2019. Through the results of association rule discovery method, the factors that increase the risk of pedestrian fatality are darkness, pedestrian walking on carriageway with traffic, intersections, high speed zone, old pedestrian, young bus driver and weekend holidays. Furthermore, co-occurrence of factors that increase the risk of a pedestrian fatality were extracted. To reduce the injuries of bus-pedestrian crashes, we recommend improving the light conditions, reducing the jaywalking behaviour of pedestrians, implementing speed bumps in high speed zones and installing pedestrian detection systems on buses.13 years of bus-pedestrian crashes in Victoria, Australia was analyzed.Association rules discovery was used for modeling pedestrian fatality.Darkness, pedestrian movement, zone speed and age effect the rate of fatality.Pattern of pedestrian fatality in collision with bus was extracted.

The influence of moisture enhancement on solid waste biodegradation

The objective of this study was to assess the influence of moisture enhancement strategies on biodegradation of municipal solid waste (MSW) in laboratory-scale reactors. Moisture enhancement strategies were varied with respect to dose volume (40, 80, 160, and 320 L/Mg-MSW) and dose frequency (dosing every ½, 1, 2, and 4 weeks). Biodegradation was evaluated based on methane generation to assess (i) the lag-time between the start of liquid dosing and onset of methane generation and (ii) the first-order decay rate for methane generation. In general, the decay rate increased with an increase in dose volume for a given dose frequency. In addition, trends of increasing decay rate and decreasing lag-time were observed for an increase in dose frequency for reactors operated with dose volumes of 40, 80, and 160 L/Mg-MSW. A key conclusion from this study was that reactors with more aggressive moisture enhancement attained more rapid methane generation that initiated at shorter elapsed times following the onset of dosing. An assessment of liquid dosing per month indicated that there were more pronounced impacts of increasing decay rate and decreasing lag-time as moisture enhancement increased from 40 L/Mg-MSW/month to 320 L/Mg-MSW/month as compared to the impact on both variables for an increase in liquid dosing above 320 L/Mg-MSW/month.

Investigating the Effective Factors on Family Physicians’ prescriptions

Introduction

The physicians are responsible for prescribing medicine rationally. Physician's awareness of prescribing guidelines can lead to the selection of the most effective, appropriate and effective measures to the improved prescription. This study aim is to determine the factors influencing drug prescribing behaviour in family physicians.

Methods

This cross-sectional study was conducted in 2016 on a case study including 150 family physicians from Shiraz City who were selected by systematic random sampling method. A questionnaire related to the behaviour of prescribing physicians was used based on the theory of planned behaviour to collect data. The validity of the questionnaire was confirmed by the experts' opinion and its reliability was confirmed by calculating the Cronbach's alpha. The data were analyzed using structural equation modelling (SEM) by SPSS and Smart PLS software.

Results

It was specified that 39.3% of Shiraz family physicians have prescribed medicines for their most patients (61-70%) during the last month. Furthermore, 60% of physicians have prescribed for about 20% of their patients without any examination. In addition, 63% of doctors have repeated prescription for about 20% of patients with chronic disease. Based on the obtained results of the Research Structural Equation Model, none of the four considered variables explains changes in physicians' behaviour regarding prescribing. Although, “mental and perceived behavioural control” explain 30.2% of the changes in the intention of prescribing medication of family physicians in Shiraz.

Conclusions

The family physicians' behaviour in prescribing medicine shows the impact of factors such as the patient's request, as well as the role of the patients and colleagues pressure for prescribing medicine as a quality criterion for their practice. norms of mental and perceived behavioural control are effective in explaining the purpose of prescribing.

Key messages

Policymakers should implement policies to develop physicians’ behavior and logical prescription by education, financial incentives; consequently. Mental and perceived behavioral control are effective in explaining the purpose of prescribing.

Evaluation of Th17 associated antigen in Old World Cutaneous Leishmaniasis: A comparative study in acute versus chronic human cutaneous Leishmaniasis using immunohistochemistry

There are little information about Th17 cells and cutaneous Leishmaniasis (CL), due to an important effect of Th17 cells on immune response, it is worth to explore the role of Th17 on CL. The purpose of this study was to assess Th17 population in patients with acute vs. chronic CL lesions in comparison with skin samples collected from healthy volunteers in an endemic region of Old World CL. A total of 49 patients with clinical manifestations of chronic (n=16) and acute (n=33) CL lesions were recruited. The clinical diagnosis of CL was confirmed by direct smear or PCR. Biopsy specimens from prelesional skin of non-infectious lesions of 30 healthy individuals were used as control. Tissue sections of 3µm thickness were prepared and used for immunohistochemistry (IHC) analysis with primary antibody specific for Th17 associated antigen (CD161). For IHC, Envision+ (DakoCytomation) system was used and developed by using diaminobenzidine (DakoCytomation). The mean age of 33 patients with acute CL and the mean age of 16 patients with chronic CL were accordingly 45.24±16.43 and 33.56±15.87. In acute and chronic CL the mean (±standard deviation) and median (±interquartile range) were accordingly 2.92±2.21, 2.56±2.9 and 2.1±1.99, 1.54±2.81. In healthy controls the mean (±standard deviation) and median (±interquartile range) were 0.72±0.41 and 0.61±0.58 respectively. With pairwise comparison of acute, chronic and control groups, there were significant difference between acute and control (P value < 0.001), chronic and control (P value = 0.043). The results showed that there was an increasing cellular response of Th17 in both acute and chronic CL patients. Th17 was significantly higher in patients with acute and chronic CL lesions in comparison with healthy control group. However, there was no significant difference between acute and chronic infection concerning to Th17 cells.

Bioperformance of chitosan/fluoride-doped diopside nanocomposite coatings deposited on medical stainless steel

This work focuses on the structure, bioactivity, corrosion, and biocompatibility characteristics of chitosan-matrix composites reinforced with various amounts of fluoride-doped diopside nanoparticles (at 20, 40, 60, and 80 wt%) deposited on stainless steel 316 L. Bioactivity studies reveal that the presence of the nanoparticles in the coatings induces apatite-forming ability to the surfaces. Based on electrochemical impedance spectroscopy and polarization experiments, the in vitro corrosion resistance of the substrate was enhanced by increasing the level of the nanoparticles in the coating. The sample containing 60% of the nanoparticles presented the highest osteoblast-like MG63 cell viability, in comparison to the other prepared and even control samples. Also, the cell attachment on the surfaces was improved with increasing the amount of the nanoparticles in the coatings. It is eventually concluded that the application of chitosan/fluoride-doped diopside nanocomposite coatings improves the bioperformance of metallic implants.

Differentiating Atypical Hemangiomas and Metastatic Vertebral Lesions: The Role of T1-Weighted Dynamic Contrast-Enhanced MRI

BACKGROUND AND PURPOSE

Vertebral hemangiomas are benign vascular lesions that are almost always incidentally found in the spine. Their classic typical hyperintense appearance on T1- and T2-weighted MR images is diagnostic. Unfortunately, not all hemangiomas have the typical appearance, and they can mimic metastases on routine MR imaging. These are generally referred to as atypical hemangiomas and can result in misdiagnosis and ultimately additional imaging, biopsy, and unnecessary costs. Our objective was to assess the utility of dynamic contrast-enhanced MR imaging perfusion in distinguishing vertebral atypical hemangiomas and malignant vertebral metastases. We hypothesized that permeability and vascular density will be increased in metastases compared with atypical hemangiomas.

MATERIALS AND METHODS

Consecutive patients from 2011 to 2015 with confirmed diagnoses of atypical hemangiomas and spinal metastases from breast and lung carcinomas with available dynamic contrast-enhanced MR imaging were analyzed. Time-intensity curves were qualitatively compared among the groups. Perfusion parameters, plasma volume, and permeability constant were quantified using an extended Tofts 2-compartment pharmacokinetic model. Statistical significance was tested using the Mann-Whitney U test.

RESULTS

Qualitative inspection of dynamic contrast-enhanced MR imaging time-intensity curves demonstrated differences in signal intensity and morphology between metastases and atypical hemangiomas. Quantitative analysis of plasma volume and permeability constant perfusion parameters showed significantly higher values in metastatic lesions compared with atypical hemangiomas (P < .001).

CONCLUSIONS

Our data demonstrate that plasma volume and permeability constant perfusion parameters and qualitative inspection of contrast-enhancement curves can be used to differentiate atypical hemangiomas from vertebral metastatic lesions. This work highlights the benefits of adding perfusion maps to conventional sequences to improve diagnostic accuracy.

Variation in bacterial endosymbionts associated with the date palm hopper, Ommatissus lybicus populations

The date palm hopper, Ommatissus lybicus, is a key pest of the date palm, which is expected to be comprised of many allopatric populations. The current study was carried out to determine bacterial endosymbiont diversity in the different populations of this pest. Ten date palm hopper populations were collected from the main date palm growing regions in Iran and an additional four samples from Pakistan, Oman, Egypt and Tunisia for detection of primary and secondary endosymbionts using polymerase chain reaction (PCR) assay with their specific primers. The PCR products were directly sequenced and edited using SeqMan software. The consensus sequences were subjected to a BLAST similarity search. The results revealed the presence of 'Candidatus Sulcia muelleri' (primary endosymbiont) and Wolbachia, Arsenophonus and Enterobacter (secondary endosymbionts) in all populations. This assay failed to detect 'Candidatus Nasuia deltocephalinicola' and Serratia in these populations. 'Ca. S. muelleri' exhibited a 100% infection frequency in populations and Wolbachia, Arsenophonus and Enterobacter demonstrated 100, 93.04 and 97.39% infection frequencies, respectively. The infection rate of Arsenophonus and Enterobacter ranged from 75 to 100% and 62.5 to 100%, respectively, in different populations of the insect. The results demonstrated multiple infections by 'Ca. Sulcia muelleri', Wolbachia, Arsenophonus and Enterobacter in the populations and may suggest significant roles for these endosymbionts on date palm hopper population fitness. This study provides an insight to endosymbiont variation in the date palm hopper populations; however, further investigation is needed to examine how these endosymbionts may affect host fitness.

T1-Weighted Dynamic Contrast-Enhanced MR Perfusion Imaging Characterizes Tumor Response to Radiation Therapy in Chordoma

BACKGROUND AND PURPOSE

Chordomas notoriously demonstrate a paucity of changes following radiation therapy on conventional MR imaging. We hypothesized that dynamic contrast-enhanced MR perfusion imaging parameters of chordomas would change significantly following radiation therapy.

MATERIALS AND METHODS

Eleven patients with pathology-proved chordoma who completed dynamic contrast-enhanced MR perfusion imaging pre- and postradiation therapy were enrolled. Quantitative tumor measurements were obtained by 2 attending neuroradiologists. ROIs were used to calculate vascular permeability and plasma volume and generate dynamic contrast-enhancement curves. Quantitative analysis was performed to determine mean and maximum plasma volume and vascular permeability values, while semiquantitative analysis on averaged concentration curves was used to determine the area under the curve. A Mann-Whitney U test at a significance level of P < .05 was used to assess differences of the above parameters between pre- and postradiation therapy.

RESULTS

Plasma volume mean (pretreatment mean = 0.82; posttreatment mean = 0.42), plasma volume maximum (pretreatment mean = 3.56; posttreatment mean = 2.27), and vascular permeability mean (pretreatment mean = 0.046; posttreatment mean = 0.028) in the ROIs significantly decreased after radiation therapy (P < .05); this change thereby demonstrated the potential for assessing tumor response. Area under the curve values also demonstrated significant differences (P < .05).

CONCLUSIONS

Plasma volume and vascular permeability decreased after radiation therapy, suggesting that these dynamic contrast-enhanced MR perfusion parameters may be useful for monitoring chordoma growth and response to radiation therapy. Additionally, the characteristic dynamic MR signal intensity-time curve of chordoma may provide a radiographic means of distinguishing chordoma from other spinal lesions.

The Long-term Outcome of Pediatric Kidney Transplantation in Iran: Results of a 25-year Single-Center Cohort Study

BACKGROUND

Kidney transplantation is the optimal treatment for end-stage renal disease in children. However, long-term graft survival has not significantly improved among pediatric patients.

OBJECTIVE

To investigate the determinants of long-term graft survival among Iranian pediatric recipients of kidney transplantation.

METHODS

In a single-center cohort study, we studied 314 pediatric kidney transplantations performed from 1989 to 2013 at Dr. Shariati Hospital, Tehran, Iran. Different variables were collected for each patient and graft survival rates were calculated.

RESULTS

After a mean±SD follow-up period of 15.8±4.0 years, the mean±SD graft survival rate was 14.5±0.5 years; the 1-, 5-, 10-, and 20-year mean graft survival rates were 90%, 81%, 62%, and 62%, respectively. The corresponding patient survival rates were 100%, 99.4%, 97.8%, and 96.5%, respectively. Pre-emptive transplantation (p=0.006), and living graft donation (p=0.002) led to higher graft survival, while acute rejection (p=0.002), and primary disease of primary hyperoxaluria (p=0.001) led to lower graft survival. Chronic rejection was the most frequent cause of graft loss.

CONCLUSION

Short-term graft survival still outpaces the long-term outcome. Modifying the mentioned determinants, with more intense immunosuppression for greater prevention of acute and chronic rejection, and increased rate of pre-emptive transplantation and living donor transplantation, long-term graft survival may significantly improve in future.

Heart Rate monitoring during physical exercise using wrist-type photoplethysmographic (PPG) signals

Heart rate monitoring using wrist-type using photoplethysmographic (PPG) signals during subjects' intensive exercises is a challenging problem, since signals are strongly affected by motion artifacts caused by unexpected movements. This paper presents a method that uses both time and frequency characteristics of signals; using sparse signal reconstruction for high-resolution spectrum estimation. Experimental results on type data sets recorded from 12 subjects during fast running at peak speed of 15 km/hour. The results have a performance with the average absolute error being 1.80 beat per minute.

Effect of Operating Parameters on Ethanol–Water Vacuum Separation in an Ethanol Dehydration Apparatus and Process Modeling with ANN

Bioethanol has been found to be a suitable substitute for gasoline in internal combustion engines. It could be used either in an undiluted form or blended with gasoline. To blend the ethanol and gasoline, the water content of ethanol should reach 0.5% or less. In the present research work, 3A Zeolite was used as an absorbent with vacuum distillation. The effects of the operating parameters such as temperature, vacuum pressure and vapor flow rate on ethanol–water separation were investigated. Final ethanol concentration was obtained at the end of every run as well as the concentration of outlet ethanol. Both linear regression and ANN design were used to determine the best fit for two final parameters. The optimum condition was obtained at 0.4 bar vacuum pressure and 20 l/min ethanol–water vapor flow rate. ANN model is more qualified to the simulation of outspread data while the linear regression is not. L10L10 mode and L5T10 mode provide the best results for final concentration and total time, respectively. The Trainlm Algorithm like the previous research training algorithm is the best.

Multimodality imaging of primary CNS lymphoma in immunocompetent patients

Primary central nervous system lymphoma (PCNSL) belongs to the group of extranodal non-Hodgkin's lymphoma, and the management of the disease is radically different from other central nervous system neoplasms. Owing to its varied appearance on imaging, diagnosis of PCNSL can be challenging. The purpose of this pictorial review is to depict the brain findings of PCNSL during initial diagnosis in immunocompetent individuals. Multimodal imaging integrating advanced sequences can facilitate differentiation of PCNSL from other CNS neoplasms.

The effect of MDMA-induced anxiety on neuronal apoptosis in adult male rats' hippocampus

Ecstasy or MDMA as a psychoactive drug and hallucinogen is considered one of the most commonly used drugs in the world. This psychotropic substance is discussed both as sexually stimulating and reducing fear and anxiety. Amphetamines also destroy neurons in some brain areas. The aim of this study was to investigate the effects of MDMA on anxiety and apoptosis of hippocampal neurons. Forty-two male Wistar rats of mean weight 200-220 g were used and distributed into six groups [control, control-saline, and experimental groups (1.25, 2.5, 5, 10 mg/kg)]. Rats in experimental groups received MDMA at different doses for seven days by intraperitoneal injection and the control-saline group received saline (1 ml/kg); anxiety was then investigated by plus-maze test. Forty-eight hours after behavioural testing brains were taken from animals and fixed, and after tissue processing, slices were stained with TUNEL kit for apoptotic cells. The area densities of apoptotic neurons were measured throughout the hippocampus and compared in all groups (P < 0.05). Physiological studies showed that 1.25 mg/kg and 2.5 mg/kg doses caused anti-anxiety behaviour and 5 and 10 mg/kg doses of MDMA caused anxietylike behaviour. Moreover, our histological study showed that ecstasy increased apoptotic cell numbers and the highest increase was observed with the 10 mg/kg dose of MDMA. We concluded that MDMA can cause different responses of anxiety-like behaviour in different doses. This phenomenon causes a different ratio of apoptosis in hippocampal formation. Reduction of anxiety-like behaviour induced by the 2.5 mg/kg dose of MDMA can control apoptosis.

Clinical standardized fMRI reveals altered language lateralization in patients with brain tumor

BACKGROUND AND PURPOSE

Brain tumors affecting language-relevant areas may influence language lateralization. The purpose of this study was to systematically investigate language lateralization in brain tumor patients using clinical language fMRI, comparing the results with a group of healthy volunteers.

MATERIALS AND METHODS

Fifty-seven strictly right-handed patients with left-hemispheric-space intracranial masses (mainly neoplastic) affecting either the Broca area (n = 19) or Wernicke area (n = 38) were prospectively enrolled in this study. Fourteen healthy volunteers served as a control group. Standardized clinical language fMRI, using visually triggered sentence- and word-generation paradigms, was performed on a 1.5T MR scanner. Semiautomated analyses of all functional data were conducted on an individual basis using BrainVoyager. A regional lateralization index was calculated for Broca and Wernicke areas separately versus their corresponding right-hemisphere homologs.

RESULTS

In masses affecting the Broca area, a significant decrease in the lateralization index was found when performing word generation (P = .0017), whereas when applying sentence generation, the decrease did not reach statistical significance (P = .851). Masses affecting the Wernicke area induced a significant decrease of the lateralization index when performing sentence generation (P = .0007), whereas when applying word generation, the decrease was not statistically significant (P = .310).

CONCLUSIONS

Clinical language fMRI was feasible for patients with brain tumors and provided relevant presurgical information by localizing essential language areas and determining language dominance. A significant effect of the brain masses on language lateralization was observed, with a shift toward the contralesional, nondominant hemisphere. This may reflect compensatory mechanisms of the brain to maintain communicative abilities.

Characterizing hypervascular and hypovascular metastases and normal bone marrow of the spine using dynamic contrast-enhanced MR imaging

BACKGROUND AND PURPOSE

The role of DCE-MR imaging in the study of bone marrow perfusion is only partially developed, though potential applications for routine use in the clinical setting are beginning to be described. We hypothesize that DCE-MR imaging can be used to discriminate between hypervascular and hypovascular metastases based on measured perfusion variables.

MATERIALS AND METHODS

We conducted a retrospective study of 26 patients using conventional MR imaging and DCE-MR imaging. Patients were assigned to a hypervascular or hypovascular group based on tumor pathology. ROIs were drawn around normal-appearing bone marrow (internal controls) and enhancing tumor areas. Average wash-in enhancement slope, average peak enhancement signal percentage change, and average peak enhancement signal percentage change in areas of highest wash-in enhancement slope were calculated. Indices were compared among control, hypervascular, and hypovascular groups. Conventional imaging was assessed by calculating pre- to postgadolinium signal percentage changes in hypervascular and hypovascular lesions.

RESULTS

Hypervascular and hypovascular tumors differed significantly with regard to wash-in enhancement slope (P < .01; hypervascular 95% CI, 22.5-26.5 AU/s; hypovascular 95% CI, 14.1-20.9 AU/s) and peak enhancement signal percentage change in areas of highest wash-in enhancement slope (P < .01; hypervascular 95% CI, 174.1-323.3%; hypovascular 95% CI, 39.5-150.5%). Peak enhancement signal percentage change over all voxels was not significant (P = .62). Areas of normal-appearing marrow showed no appreciable contrast enhancement. Conventional contrast-enhanced MR imaging was unable to differentiate between hypervascular and hypovascular tumors (P = .58).

CONCLUSIONS

Our data demonstrate that, unlike conventional MR imaging sequences, DCE-MR imaging may be a more accurate technique in discriminating hypervascular from hypovascular spinal metastases.

Primary anaplastic large cell lymphoma of trachea with subcutaneous emphysema and progressive dyspnea

Primary anaplastic large cell lymphoma of the trachea is a rare tumor. Common complaints are dyspnea and cough that could mimic a partially refractory asthma in some cases. We report a 16-year-old female with an anaplastic large cell lymphoma (null cell type) in which tracheal involvement was presented with life-threatening airway obstruction and subcutaneous emphysema. After debulking the tumor by endobronchial curettage, the patient was treated with chemotherapy followed by local radiotherapy. She had no evidence of local or distant recurrence after 25 months. Primary anaplastic large cell lymphoma of the trachea is a rare life-threatening disease. Nevertheless, this condition has a good prognosis if diagnosed immediately and treated with chemotherapy and radiotherapy.

IL-2-inducible T-cell kinase deficiency with pulmonary manifestations due to disseminated Epstein-Barr virus infection

IL-2-inducible T-cell kinase (ITK) deficiency is a rare inherited immunodeficiency disease characterized by homozygous mutations in the ITK gene and the inability to control Epstein-Barr virus (EBV) infection leading to EBV-associated lymphoproliferative disorders of B cell origin. Many aspects of its clinical presentation and immunologic phenotype are still unclear to clinicians. We report on a 14-year-old female patient with complaints of an 8-month history of cough and fever. Imaging studies revealed diffuse pulmonary nodules and mediastinal lymphadenopathy. Transbronchial lung biopsy showed nonmalignant polyclonal B cell proliferation. High titers of EBV DNA were detected by PCR analysis in bronchoalveolar lavage fluid, bone marrow, and blood. Genomic analysis revealed a homozygous single base pair deletion in exon 5 of the ITK gene (c.468delT) in this patient. Treatment with rituximab (anti-CD20 mab) resulted in complete clinical remission with resolution of pulmonary lesions and a negative EBV titer in serum. All patients with EBV-associated lymphoproliferative disorders should be analyzed for mutations in ITK.

Isolated diffusion restriction precedes the development of enhancing tumor in a subset of patients with glioblastoma

BACKGROUND AND PURPOSE

Most response criteria for patients with glioblastoma rely on increases in the contrast enhancing abnormality to determine tumor progression. Our aim was to determine retrospectively in patients with glioblastoma whether diffusion restriction can predict the development of new enhancing mass lesions.

MATERIALS AND METHODS

We reviewed the brain MR imaging scans (including DWI and ADC maps) of 208 patients with glioblastoma. Patients with restricted diffusion in or adjacent to the tumor were identified, with further analysis only performed on those patients with low-ADC lesions without enhancement. These patients were followed to determine if new concordant enhancement developed at the site of the low-ADC lesion. A Wilcoxon signed rank test, competing risk analysis, and Kaplan-Meier curves were used to compare the mean drop in ADC values, assess enhancement-free survival, and determine overall survival, respectively.

RESULTS

In 67 of the 208 patients (32.2%), visibly detectable restricted diffusion was seen during treatment. The study cohort was formed by the 27 patients with low-ADC lesions and no corresponding enhancement. Twenty-three (85.2%) patients developed gadolinium-enhancing tumor at the site of restricted diffusion a median of 3.0 months later (95% CI, 2.6-4.1 months). The mean decrease in ADC was 22.9% from baseline (P < .001). The 3-month enhancement-free survival probability was 0.481 (95% CI, 0.288-0.675). The 12-month overall survival probability was 0.521 (95% CI, 0.345-0.788). Restricted diffusion predicted enhancement regardless of antiangiogenic therapy with bevacizumab.

CONCLUSIONS

In a subset of patients with glioblastoma, development of a new focus of restricted diffusion during treatment may precede the development of new enhancing tumor.