Serum Insulin-Like Growth Factor-1 in Parkinson's Disease; Study of Cerebrospinal Fluid Biomarkers and White Matter Microstructure

Background: Growing evidence shows that impaired signaling of Insulin-like Growth Factor-1 (IGF-1) is associated with neurodegenerative disorders, such as Parkinson's disease (PD). However, there is still controversy regarding its proinflammatory or neuroprotective function. In an attempt to elucidate the contribution of IGF-1 in PD, we aimed to discover the relation between serum IGF-1 levels in drug-naïve early PD patients and cerebrospinal fluid (CSF) biomarkers as well as microstructural changes in brain white matter.Methods: The association between quartiles of serum IGF-1 levels and CSF biomarkers (α-synuclein, dopamine, amyloid-β1−42, total tau, and phosphorylated tau) was investigated using adjusted regression models in 404 drug-naïve early PD patients with only mild motor manifestations and 188 age- and sex-matched healthy controls (HC) enrolled in the Parkinson's Progression Markers Initiative (PPMI). By using region of interest analysis and connectometry approach, we tracked the white matter microstructural integrity and diffusivity patterns in a subgroup of study participants with available diffusion MRI data to investigate the association between subcomponents of neural pathways with serum IGF-1 levels.Results: PD patients had higher levels of IGF-1 compared to HC, although not statistically significant (mean difference: 3.60, P = 0.44). However, after adjustment for possible confounders and correction for False Discovery Rate (FDR), IGF-1 was negatively correlated with CSF α-synuclein, total and phosphorylated tau levels only in PD subjects. The imaging analysis proved a significant negative correlation (FDR corrected P-value = 0.013) between continuous levels of serum IGF-1 in patients with PD and the connectivity, but not integrity, in following fibers while controlling for age, sex, body mass index, depressive symptoms, education years, cognitive status and disease duration: middle cerebellar peduncle, cingulum, genu and splenium of the corpus callosum. No significant association was found between brain white matter microstructral measures or CSF markers of healthy controls and levels of IGF-1.Conclusion: Altered connectivity in specific white matter structures, mainly involved in cognitive and motor deterioration, in association with higher serum IGF-1 levels might propose IGF-1 as a potential associate of worse outcome in response to higher burden of α-synucleinopathy and tauopathy in PD

The effect of Noise on blood pressure and heart rate in an automotive industry

Introduction: One of the possible effects of occupational exposure to high noise is high blood pressure and cardiovascular disease. Aim of this study was to investigate the association between noise with blood pressure and heart rate in an automotive industry. Methods: 78 male workers who worked in an automobile factory, were participated. Blood pressure and heart rate were measured in the morning and in the middle of the day. All measurements were performed at three noise levels: 85-95, 75-85 and 65-75 dB. All data were analyzed using SPSS and MATLAB. Results: Post Hoc test showed that noise has the same effect on the average systolic and diastolic blood pressure (p= 0.733) but Box-whisker plot showed that after exposure, the variation range of blood pressure and heart rate are much more than the other groups. However, this project didn’t show any a specific correlation between the increase in noise level with heart rate but variance analysis showed that the noise level increase lead to changes in heart rate (p= 0.049).  Conclusions: Noise level in 75-85dB as same as 85-95 dB caused the changes in blood pressure and heart rate. Due to cardiovascular disease, it is recommended training programs for workers, reduced noise level and periodic monitoring of blood pressure of workers, especially with a history of hypertension

Capturing Bone Signal in MRI of Pelvis, as a Large FOV Region, Using TWIST Sequence and Generating a 5-Class Attenuation Map for Prostate PET/MRI Imaging

Purpose: Prostate imaging is a major application of hybrid positron emission tomography/magnetic resonance imaging (PET/MRI). Currently, MRI-based attenuation correction (MRAC) for whole-body PET/MRI in which the bony structures are ignored is the main obstacle to successful implementation of the hybrid modality in the clinical work flow. Ultrashort echo time sequence captures bone signal but needs specific hardware–software and is challenging in large field of view (FOV) regions, such as pelvis. The main aims of the work are (1) to capture a part of the bone signal in pelvis using short echo time (STE) imaging based on time-resolved angiography with interleaved stochastic trajectories (TWIST) sequence and (2) to consider the bone in pelvis attenuation map (µ-map) to MRAC for PET/MRI systems. Procedures: Time-resolved angiography with interleaved stochastic trajectories, which is routinely used for MR angiography with high temporal and spatial resolution, was employed for fast/STE MR imaging. Data acquisition was performed in a TE of 0.88 milliseconds (STE) and 4.86 milliseconds (long echo time [LTE]) in pelvis region. Region of interest (ROI)-based analysis was used for comparing the signal-to-noise ratio (SNR) of cortical bone in STE and LTE images. A hybrid segmentation protocol, which is comprised of image subtraction, a Fuzzy-based segmentation, and a dedicated morphologic operation, was used for generating a 5-class µ-map consisting of cortical bone, air cavity, fat, soft tissue, and background (µ-map MR-5c ). A MR-based 4-class µ-map (µ-map MR-4c ) that considered soft tissue rather than bone was generated. As such, a bilinear (µ-map CT-ref ), 5 (µ-map CT-5c ), and 4 class µ-map (µ-map CT-4c ) based on computed tomography (CT) images were generated. Finally, simulated PET data were corrected using µ-map MR-5c (PET-MRAC5c), µ-map MR-4c (PET-MRAC4c), µ-map CT-5c (PET-CTAC5c), and µ-map CT-ref (PET-CTAC). Results: The ratio of SNR bone to SNR air cavity in LTE images was 0.8, this factor was increased to 4.4 in STE images. The Dice, Sensitivity, and Accuracy metrics for bone segmentation in proposed method were 72.4% ± 5.5%, 69.6% ± 7.5%, and 96.5% ± 3.5%, respectively, where the segmented CT served as reference. The mean relative error in bone regions in the simulated PET images were −13.98% ± 15%, −35.59% ± 15.41%, and 1.81% ± 12.2%, respectively, in PET-MRAC5c, PET-MRAC4c, and PET-CTAC5c where PET-CTAC served as the reference. Despite poor correlation in the joint histogram of µ-map MR-4c versus µ-map CT-5c (R 2 > 0.78) and PET-MRAC4c versus PET-CTAC5c (R 2 = 0.83), high correlations were observed in µ-map MR-5c versus µ-map CT-5c (R 2 > 0.94) and PET-MRAC5c versus PET-CTAC5c (R 2 > 0.96). Conclusions: According to the SNR STE, pelvic bone , the cortical bone can be separate from air cavity in STE imaging based on TWIST sequence. The proposed method generated an MRI-based µ-map containing bone and air cavity that led to more accurate tracer uptake estimation than MRAC4c. Uptake estimation in hybrid PET/MRI can be improved by employing the proposed method