Absolute Metabolite Quantification in Individuals with Glioma and Healthy Individuals Using Whole-Brain Three-dimensional MR Spectroscopic and Echo-planar Time-resolved Imaging.

BACKGROUND: MR spectroscopic imaging (MRSI) can be used to quantify an extended brain metabolic profile but is confounded by changes in tissue water levels due to disease. PURPOSE: To develop a fast absolute quantification method for metabolite concentrations combining whole-brain MRSI with echo-planar time-resolved imaging (EPTI) relaxometry in individuals with glioma and healthy individuals. MATERIALS AND METHODS: In this prospective study performed from August 2022 to August 2023, using internal water as concentration reference, the MRSI-EPTI quantification method was compared with the conventional method using population-average literature relaxation values. Healthy participants and participants with mutant IDH1 gliomas underwent imaging at 3 T with a 32-channel coil. Real-time navigated adiabatic spiral three-dimensional MRSI scans were acquired in approximately 8 minutes and reconstructed with a super-resolution pipeline to obtain brain metabolic images at 2.4-mm isotropic resolution. High-spatial-resolution multiparametric EPTI was performed in 3 minutes, with 1-mm isotropic resolution, to correct the relaxation and proton density of the water reference signal. Bland-Altman analysis and the Wilcoxon signed rank test were used to compare absolute quantifications from the proposed and conventional methods. RESULTS: Six healthy participants (four male; mean age, 37 years ± 11 [SD]) and nine participants with glioma (six male; mean age, 41 years ± 15; one with wild-type IDH1 and eight with mutant IDH1) were included. In healthy participants, there was good agreement (+4% bias) between metabolic concentrations derived using the two methods, with a CI of plus or minus 26%. In participants with glioma, there was large disagreement between the two methods (+39% bias) and a CI of plus or minus 55%. The proposed quantification method improved tumor contrast-to-noise ratio (median values) for total N-acetyl-aspartate (EPTI: 0.541 [95% CI: 0.217, 0.910]; conventional: 0.484 [95% CI: 0.199, 0.823]), total choline (EPTI: 1.053 [95% CI: 0.681, 1.713]; conventional: 0.940 [95% CI: 0.617, 1.295]), and total creatine (EPTI: 0.745 [95% CI: 0.628, 0.909]; conventional: 0.553 [95% CI: 0.444, 0.828]) (P = .03 for all). CONCLUSION: The whole-brain MRSI-EPTI method provided fast absolute quantification of metabolic concentrations with individual-specific corrections at 2.4-mm isotropic resolution, yielding concentrations closer to the true value in disease than the conventional literature-based corrections. © RSNA, 2024 Supplemental material is available for this article.

Effects of thyroxin and luteinizing hormone releasing hormone on reproductive physiology of Rohu (Labeo rohita): Insights into spawning performance, oocyte maturation, steroidogenesis, and follicular development genes.

As the global aquaculture industry grows, attention is increasingly turning towards assisted reproductive technologies. In this study, we examined the impact of D-Ala6, Pro9-Net-mGnRH (LHRHa: 0.4 mL/kg) and two doses (1 and 10 µg/kg fish) of thyroxin (T4) administered through a single injection on oocyte maturation, spawning performance, sex steroid hormone levels, as well as the expression of genes related to steroidogenesis and follicle development (ZP2, Cyp19a1a and SF-1) in Rohu (Labeo rohita). The study found that untreated female Rohu did not spawn, while those treated with LHRHa and thyroxin ovulated and spawned across a hormonal gradient. The highest spawning success was observed with a thyroxin dosage of 10 µg/kg (no significant change with a dose of 1 µg/kg), and female latency period decreased with increasing dosage. Additionally, females treated with thyroxin exhibited significantly higher fecundity than other experimental groups. Treatment with LHRHa and two doses of thyroxin significantly increased the gonadal somatic index compared to the control and sham groups. Hormonal treatment also led to increased fertilization success, hatching rate, and larval survival. At 12 h post-injection, females treated with thyroxin exhibited a significant decline in estradiol levels and expression of Zp2, Cyp19a1a, and SF-1 compared to other experimental groups. Levels of DHP significantly increased across the hormonal gradient. Histological analyses supported a steroidogenic shift, where oocyte maturation was accelerated by hormone administration, particularly with both doses of thyroxin. In conclusion, the findings suggest that thyroxin is a recommended treatment for assisted reproduction of Rohu due to its ability to induce spawning, increase fecundity and improve larval survival.

Harnessing paraprobiotics and postbiotics for enhanced immune function in Asian seabass (Lates calcarifer): Insights into pattern recognition receptor signaling.

The Asian seabass, Lates calcarifer, is a key species in Asian aquaculture due to its nutritional value and adaptability. However, disease outbreaks, particularly viral and bacterial infections, pose significant challenges to its production. Immunostimulants offer promising solutions but raise safety concerns. Paraprobiotics and postbiotics (CPP) emerge as safer alternatives, exerting health benefits without live microorganisms. This study investigated the potential of probiotic paraprobiotic and postbiotic supplements derived from Bacillus subtilis to enhance the immune response and antioxidant capacity of Asian seabass and improve their resistance to Streptococcus iniae infection. Analysis of antioxidant activity and lipid peroxidation revealed significant improvements in fish supplemented with CPP, indicating their effectiveness in mitigating oxidative stress. Immunological assays demonstrated enhanced growth performance and serum immunity, including increased alternative complement activity, immunoglobulin levels, and phagocytic activity, in supplemented fish. Furthermore, upregulated expression of proinflammatory cytokines (TNF-α, IL-6, IL-1ß) and pattern recognition receptors (NLRC3, TLR22, MDA5) in immune tissues. Fish supplemented with CPP exhibited higher resistance and survival rates against S. iniae infection challenge compared to control groups. The study elucidates the mechanisms underlying the immunomodulatory effects of CPP, shedding light on their potential applications in aquaculture.

Microencapsulation of Lactobacillus plantarum in the alginate/chitosan improves immunity, disease resistance, and growth of Nile tilapia (Oreochromis niloticus).

This study evaluated the effects of microencapsulation of L. plantarum (as a probiotic) with chitosan/alginate biopolymers (MLCA) on innate immune response, disease resistance, and growth performance of Nile tilapia (Oreochromis niloticus). Four hundred and eighty fish were randomly distributed in glass tanks (150 L) and fed with diets including diet 1: control; diet 2: 10 g kg-1 microcapsules; diet 3: 108 CFU g-1 L. plantarum; and diet 4: 10 g kg-1 MLCA for 60 days. The hematology and biochemical indices, lysozyme activity, alternative complement activities, respiratory burst, serum bactericidal activity, as well as growth performance parameters (specific growth rate, feed conversion ratio) were analyzed. White blood cells, plasma protein and globulin concentration, serum lysozyme, and respiratory burst activities of fish were significantly increased (P < 0.05) in the MLCA diet. A challenge test against Streptococcus agalactiae, at the end of the experiment, showed the highest survival rate of the fish fed with MLCA. Moreover, the fish fed with MLCA showed a significant improvement in SGR (3.12 ± 0.18%) and FCR (1.23 ± 0.20) and had the highest growth performance. These results suggest longer stability of probiotics in the microcapsules, and their immunomodulatory effect can be considered a promising immunostimulant and growth enhancer in the Nile tilapia diet.

Bilateral gradient-echo spectroscopic imaging with correction of frequency variations for measurement of fatty acid composition in mammary adipose tissue.

PURPOSE: To develop a simultaneous dual-slab three-dimensional gradient-echo spectroscopic imaging (GSI) technique with frequency drift compensation for rapid (<6 min) bilateral measurement of fatty acid composition (FAC) in mammary adipose tissue. METHODS: A bilateral GSI sequence was developed using a simultaneous dual-slab excitation followed by 128 monopolar echoes. A short train of navigator echoes without phase or partition encoding was included at the beginning of each pulse repetition time period to correct for frequency variation caused by respiration and heating of the cryostat. Voxel-wise spectral fitting was applied to measure the areas of the lipid spectral peaks to estimate the number of double-bond (ndb), number of methylene-interrupted double-bond (nmidb), and chain length (cl). The proposed method was tested in an oil phantom and 10 postmenopausal women to assess the influence of the frequency variation on FAC estimation. RESULTS: The frequency drift observed over 5:27 min during the phantom scan was about 10 Hz. Phase correction based on the navigator reduced the median error of ndb, nmidb, and cl from 9.7%, 17.6%, and 3.2% to 2.1%, 9.5%, and 2.8%, respectively. The in vivo data showed a mean ± standard deviation frequency drift of 17.4 ± 2.5 Hz, with ripples at 0.3 ± 0.1 Hz. Our reconstruction algorithm successfully separated signals from the left and right breasts with negligible residual aliasing. Phase correction reduced the interquartile range within each subject's adipose tissue of ndb, nmidb, and cl by 18.4 ± 10.6%, 18.5 ± 13.9%, and 18.4 ± 10.6%, respectively. CONCLUSION: This study shows the feasibility of obtaining bilateral spectroscopic imaging data in the breast and that incorporation of a frequency navigator improves the estimation of FAC.

Evaluation of metronomic chemotherapy response using diffusion and dynamic contrast-enhanced MRI.

PURPOSE: To investigate the feasibility of using diffusion MRI (dMRI) and dynamic contrast-enhanced (DCE) MRI to evaluate the treatment response of metronomic chemotherapy (MCT) in the 4T1 mammary tumor model of locally advanced breast cancer. METHODS: Twelve Balb/c mice with metastatic breast cancer were divided into treated and untreated (control) groups. The treated group (n = 6) received five treatments of anti-metabolite agent 5-Fluorouracil (5FU) in the span of two weeks. dMRI and DCE-MRI were acquired for both treated and control groups before and after MCT. Immunohistochemically staining and measurements were performed after the post-MRI measurements for comparison. RESULTS: The control mice had significantly (p<0.005) larger tumors than the MCT treated mice. The DCE-MRI analysis showed a decrease in contrast enhancement for the control group, whereas the MCT mice had a more stable enhancement between the pre-chemo and post-chemo time points. This confirms the antiangiogenic effects of 5FU treatment. Comparing amplitude of enhancement revealed a significantly (p<0.05) higher enhancement in the MCT tumors than in the controls. Moreover, the MCT uptake rate was significantly (p<0.001) slower than the controls. dMRI analysis showed the MCT ADC values were significantly larger than the control group at the post-scan time point. CONCLUSION: dMRI and DCE-MRI can be used as potential biomarkers for assessing the treatment response of MCT. The MRI and pathology observations suggested that in addition to the cytotoxic effect of cell kills, the MCT with a cytotoxic drug, 5FU, induced changes in the tumor vasculature similar to the anti-angiogenic effect.

Assessment of tumor treatment response using active contrast encoding (ACE)-MRI: Comparison with conventional DCE-MRI.

PURPOSE: To investigate the validity of contrast kinetic parameter estimates from Active Contrast Encoding (ACE)-MRI against those from conventional Dynamic Contrast-Enhanced (DCE)-MRI for evaluation of tumor treatment response in mouse tumor models. METHODS: The ACE-MRI method that incorporates measurement of T1 and B1 into the enhancement curve washout region, was implemented on a 7T MRI scanner to measure tracer kinetic model parameters of 4T1 and GL261 tumors with treatment using bevacizumab and 5FU. A portion of the same ACE-MRI data was used for conventional DCE-MRI data analysis with a separately measured pre-contrast T1 map. Tracer kinetic model parameters, such as Ktrans (permeability area surface product) and ve (extracellular space volume fraction), estimated from ACE-MRI were compared with those from DCE-MRI, in terms of correlation and Bland-Altman analyses. RESULTS: A three-fold increase of the median Ktrans by treatment was observed in the flank 4T1 tumors by both ACE-MRI and DCE-MRI. In contrast, the brain tumors did not show a significant change by the treatment in either ACE-MRI or DCE-MRI. Ktrans and ve values of the tumors from ACE-MRI were strongly correlated with those from DCE-MRI methods with correlation coefficients of 0.92 and 0.78, respectively, for the median values of 17 tumors. The Bland-Altman plot analysis showed a mean difference of -0.01 min-1 for Ktrans with the 95% limits of agreement of -0.12 min-1 to 0.09 min-1, and -0.05 with -0.37 to 0.26 for ve. CONCLUSION: The tracer kinetic model parameters estimated from ACE-MRI and their changes by treatment closely matched those of DCE-MRI, which suggests that ACE-MRI can be used in place of conventional DCE-MRI for tumor progression monitoring and treatment response evaluation with a reduced scan time.

Advances in Diffusion and Perfusion MRI for Quantitative Cancer Imaging.

PURPOSE OF REVIEW: This article is to review recent technical developments and their clinical applications in cancer imaging quantitative measurement of cellular and vascular properties of the tumors. RECENT FINDINGS: Rapid development of fast Magnetic Resonance Imaging (MRI) technologies over last decade brought new opportunities in quantitative MRI methods to measure both cellular and vascular properties of tumors simultaneously. SUMMARY: Diffusion MRI (dMRI) and dynamic contrast enhanced (DCE)-MRI have become widely used to assess the tissue structural and vascular properties, respectively. However, the ultimate potential of these advanced imaging modalities has not been fully exploited. The dependency of dMRI on the diffusion weighting gradient strength and diffusion time can be utilized to measure tumor perfusion, cellular structure, and cellular membrane permeability. Similarly, DCE-MRI can be used to measure vascular and cellular membrane permeability along with cellular compartment volume fractions. To facilitate the understanding of these potentially important methods for quantitative cancer imaging, we discuss the basic concepts and recent developments, as well as future directions for further development.

Robust time-shifted spoke pulse design in the presence of large B0 variations with simultaneous reduction of through-plane dephasing, B1+ effects, and the specific absorption rate using parallel transmission.

PURPOSE: To design parallel transmission spokes pulses with time-shifted profiles for joint mitigation of intensity variations due to B1+ effects, signal loss due to through-plane dephasing, and the specific absorption rate (SAR) at 7T. METHODS: We derived a slice-averaged small tip angle (SA-STA) approximation of the magnetization signal at echo time that depends on the B1+ transmit profiles, the through-slice B0 gradient and the amplitude and time-shifts of the spoke waveforms. We minimize a magnitude least-squares objective based on this signal equation using a fast interior-point approach with analytical expressions of the Jacobian and Hessian. RESULTS: Our algorithm runs in less than three minutes for the design of two-spoke pulses subject to hundreds of local SAR constraints. On a B0/B1+ head phantom, joint optimization of the channel-dependent time-shifts and spoke amplitudes allowed signal recovery in high-B0 regions at no increase of SAR. Although the method creates uniform magnetization profiles (ie, uniform intensity), the flip angle varies across the image, which makes it ill-suited to T1-weighted applications. CONCLUSIONS: The SA-STA approach presented in this study is best suited to T2*-weighted applications with long echo times that require signal recovery around high B0 regions. Magn Reson Med 76:540-554, 2016. © 2015 Wiley Periodicals, Inc.

Mercury concentrations in common carp (Cyprinus carpio) tissues, sediment and water from fish farm along the Karoun River in Iran.

The Karoun River is major source of water for warm|water fish culture industry in southwest of Iran. The aim of the present study was to investigate the distribution of mercury in tissues of marketable common carp and in bottom sediments of fish farms in Khouzestan province. This study was carried out on 45 fish farms that are located on the bank of the Karoun River in Khouzestan province, south-west Iran. Concentration of mercury (Hg) was determined using spectrophotometery in three tissues (muscles, liver and gills) of farmed common carp (Cyprinus carpio), water and bottom sediments of fish farms collected from three regions (North, center and south) of the Karoun River, in Khouzestan province, Iran. The concentrations of Hg in muscle tissue (2.71 mg kg(-1) dry matter) of fish from the south were significantly higher (p < 0.05) than from the other two sites. In the center and south sampling zones, Hg concentration in muscle was found to be above the maximum tolerable values provided by Food and Drug Administration standards. The Hg concentration of fish farm sediment and water samples were ranged as 0.46 to 0.48 mg kg(-1) dry matter and 3.10 to 4.11 µg Hg L(-1), respectively. Finally, Hg concentrations at downstream site were higher than upstream site.

Considerations for integration of a physiological radar monitoring system with gold standard clinical sleep monitoring systems.

A design for a physiological radar monitoring system (PRMS) that can be integrated with clinical sleep monitoring systems is presented. The PRMS uses two radar systems at 2.45 GHz and 24 GHz to achieve both high sensitivity and high resolution. The system can acquire data, perform digital processing and output appropriate conventional analog outputs with a latency of 130 ms, which can be recorded and displayed by a gold standard sleep monitoring system, along with other standard sensor measurements.

Determination of lead, mercury and cadmium in wild and farmed Barbus sharpeyi from Shadegan Wetland and Azadegan Aquaculture Site, South of Iran.

Lead, mercury and cadmium concentrations were measured in muscle, liver and gill in wild and farmed Barbus sharpeyi from Shadegan Wetland (SW) and Azadegan Aquaculture Site (AAS). Significant variation in metal values were evaluated in Students' tests at p > 0.05. Results showed: In B. sharpeyi high levels of cadmium, lead, and mercury were measured in gill (0.34, 0.68, and 0.06 mg kg(-1) dw). The concentration of metals was not significantly different (p ≥ 0.05) in the muscle between SW (Cd, 0.24; Pb, 0.49 and Hg, 0.04) and AAS (Cd, 0.23; Pb, 0.49 and Hg, 0.04). Lead concentration was higher than cadmium and mercury in different organs (p > 0.05). Cadmium, mercury and lead in different tissues of SW were higher than AAS and there was no significant difference between them (p ≥ 0.05). Metal levels in different tissues were higher than WHO standard.

Respiration-rate estimation of a moving target using impulse-based ultra wideband radars.

Recently, Ultra-wide band signals have become attractive for their particular advantage of having high spatial resolution and good penetration ability which makes them suitable in medical applications. One of these applications is wireless detection of heart rate and respiration rate. Two hypothesis of static environment and fixed patient are considered in the method presented in previous literatures which are not valid for long term monitoring of ambulant patients. In this article, a new method to detect the respiration rate of a moving target is presented. The first algorithm is applied to the simulated and experimental data for detecting respiration rate of a fixed target. Then, the second algorithm is developed to detect respiration rate of a moving target. The proposed algorithm uses correlation for body movement cancellation, and then detects the respiration rate based on energy in frequency domain. The results of algorithm prove an accuracy of 98.4 and 97% in simulated and experimental data, respectively.

Parametric study of antennas for long range Doppler radar heart rate detection.

This research presents results obtained from long range measurements of physiological motion pertaining to human cardiac and respiration activity. A pulse pressure sensor was used as reference to verify the results from radar signals. A motion detection and grading algorithm was used to detect the presence of heart rate. In addition to showing that human heart rate and respiration can be measured at distances of 21 and 69 meters respectively, the effect of antenna size, radiation pattern and gain on the range of the radar has also been studied.

A new algorithm for detection of heart and respiration rate with UWB signals.

Proposed is a detection algorithm for physiological monitoring with Ultra Wide Band (UWB) radar. This new algorithm is based on detection of movement energy in a specified band of frequency using wavelet and filter banks. One of the advantages of this algorithm is its ability to detect heart and respiration rates of a subject in an environment containing other motion. The heart movement is detected with the accuracy of 95% and respiration with the 100%. This algorithm has a repeatability of 93% which is a significant characteristic of the method.