Optical properties of fresh and frozen tissues of rat heart, kidney, brain, liver, and muscle were measured in the 450- to 700-nm range. The total reflectance and transmittance were measured using a ...well-calibrated integral sphere set-up. Absorption coefficient μa and reduced scattering coefficient μ′s were derived from the experimental measurements using the inverse adding doubling technique. The influence of cryogenic processing on optical properties was studied. Interindividual and intraindividual variations were assessed. These new data aim at filling the lack of validated optical properties in the visible range especially in the blue-green region of particular interest for fluorescence and optogenetics preclinical studies. Furthermore, we provide a unique comparison of the optical properties of different organs obtained using the same measurement set-up for fresh and frozen tissues as well as an estimate of the intraindividual and interindividual variability.
Purpose
The aim of this work was to demonstrate the pharmacokinetic potential of a wireless pixelated β
+
-sensitive probe (PIXSIC).
Procedures
The binding of 2′-methoxyphenyl-(
N
-2′-pyridinyl)-p-
...18
Ffluoro-benzamidoethylpiperazine (
18
FMPPF), a 5-HT
1A
serotonin receptor radiopharmaceutical, was measured in anesthetized rats and compared to microPET data. The effects of a 5-HT
1A
antagonist injection on
in vivo
18
FMPPF binding were monitored by PIXSIC.
Results
PIXSIC allowed differentiating the radioactive kinetics according to the location of its pixels in the hippocampus, cortex, corpus callosum, and cerebellum. The device accurately detected the changes in
18
FMPPF binding, after 5-HT
1A
antagonist blockade. The time–activity curves were reproducible and consistent with kinetics obtained simultaneously with a microPET camera.
Conclusions
These results demonstrate the ability of the PIXSIC device to record reliably the binding of PET ligands, with a high spatiotemporal resolution in anesthetized rodents. These first
in vivo
results are a key stage on the path to its implementation in awake freely moving animals.
Congenital erythropoietic porphyria (CEP) is due to a deficiency in the enzymatic activity of uroporphyrinogen III synthase (UROS); such a deficiency leads to porphyrin accumulation and results in ...skin lesions and hemolytic anemia. CEP is a candidate for retrolentivirus-mediated gene therapy, but recent reports of insertional leukemogenesis underscore the need for safer methods. The discovery of induced pluripotent stem cells (iPSCs) has opened up new horizons in gene therapy because it might overcome the difficulty of obtaining sufficient amounts of autologous hematopoietic stem cells for transplantation and the risk of genotoxicity. In this study, we isolated keratinocytes from a CEP-affected individual and generated iPSCs with two excisable lentiviral vectors. Gene correction of CEP-derived iPSCs was obtained by lentiviral transduction of a therapeutic vector containing UROS cDNA under the control of an erythroid-specific promoter shielded by insulators. One iPSC clone, free of reprogramming genes, was obtained with a single proviral integration of the therapeutic vector in a genomic safe region. Metabolic correction of erythroblasts derived from iPSC clones was demonstrated by the disappearance of fluorocytes. This study reports the feasibility of porphyria gene therapy with the use of iPSCs.
The investigation of neurophysiological mechanisms underlying the functional specificity of brain regions requires the development of technologies that are well adjusted to in vivo studies in small ...animals. An exciting challenge remains the combination of brain imaging and behavioural studies, which associates molecular processes of neuronal communications to their related actions. A pixelated intracerebral probe (PIXSIC) presents a novel strategy using a submillimetric probe for beta+ radiotracer detection based on a pixelated silicon diode that can be stereotaxically implanted in the brain region of interest. This fully autonomous detection system permits time-resolved high sensitivity measurements of radiotracers with additional imaging features in freely moving rats. An application-specific integrated circuit (ASIC) allows for parallel signal processing of each pixel and enables the wireless operation. All components of the detector were tested and characterized. The beta+ sensitivity of the system was determined with the probe dipped into radiotracer solutions. Monte Carlo simulations served to validate the experimental values and assess the contribution of gamma noise. Preliminary implantation tests on anaesthetized rats proved PIXSIC's functionality in brain tissue. High spatial resolution allows for the visualization of radiotracer concentration in different brain regions with high temporal resolution.
As mouse imaging has become more challenging in preclinical research, efforts have been made to develop dedicated PET systems. Although these systems are currently used for the study of ...physiopathologic murine models, they present some drawbacks for brain studies, including a low temporal resolution that limits the pharmacokinetic study of radiotracers. The aim of this study was to demonstrate the ability of a radiosensitive intracerebral probe to measure the binding of a radiotracer in the mouse brain in vivo. Methods: The potential of a probe 0.25 mm in diameter for pharmacokinetic studies was assessed. First, Monte Carlo simulations followed by experimental studies were used to evaluate the detection volume and sensitivity of the probe and its adequacy for the size of loci in the mouse brain. second, ex vivo autoradiography of 5-hydroxytryptamine receptor 1A (5-HT^sub 1A^) receptors in the mouse brain was performed with the PET radiotracer 2'-methoxyphenyl-(N-2'-pyridinyl)-p-^sup 18^F-fluorobenzamidoethylpiperazine (^sup 18^F-MPPF). Finally, the binding kinetics of ^sup 18^F-MPPF were measured in vivo in both the hippocampus and the cerebellum of mice. Results: Both the simulations and the experimental studies demonstrated the feasibility of using small probes to measure radioactive concentrations in specific regions of the mouse brain. Ex vivo autoradiography showed a heterogeneous distribution of ^sup 18^F-MPPF consistent with the known distribution of 5-HT^sub 1A^ in the mouse brain. Finally, the time-activity curves obtained in vivo were reproducible and validated the capacity of the new probe to accurately measure ^sup 18^F-MPPF kinetics in the mouse hippocampus. Conclusion: Our results demonstrate the ability of the tested radiosensitive intracerebral probe to monitor binding of PET radiotracers in anesthetized mice in vivo, with high temporal resolution suited for compartmental modeling. PUBLICATION ABSTRACT
As mouse imaging has become more challenging in preclinical research, efforts have been made to develop dedicated PET systems. Although these systems are currently used for the study of ...physiopathologic murine models, they present some drawbacks for brain studies, including a low temporal resolution that limits the pharmacokinetic study of radiotracers. The aim of this study was to demonstrate the ability of a radiosensitive intracerebral probe to measure the binding of a radiotracer in the mouse brain in vivo.
The potential of a probe 0.25 mm in diameter for pharmacokinetic studies was assessed. First, Monte Carlo simulations followed by experimental studies were used to evaluate the detection volume and sensitivity of the probe and its adequacy for the size of loci in the mouse brain. Second, ex vivo autoradiography of 5-hydroxytryptamine receptor 1A (5-HT(1A)) receptors in the mouse brain was performed with the PET radiotracer 2'-methoxyphenyl-(N-2'-pyridinyl)-p-(18)F-fluorobenzamidoethylpiperazine ((18)F-MPPF). Finally, the binding kinetics of (18)F-MPPF were measured in vivo in both the hippocampus and the cerebellum of mice.
Both the simulations and the experimental studies demonstrated the feasibility of using small probes to measure radioactive concentrations in specific regions of the mouse brain. Ex vivo autoradiography showed a heterogeneous distribution of (18)F-MPPF consistent with the known distribution of 5-HT(1A) in the mouse brain. Finally, the time-activity curves obtained in vivo were reproducible and validated the capacity of the new probe to accurately measure (18)F-MPPF kinetics in the mouse hippocampus.
Our results demonstrate the ability of the tested radiosensitive intracerebral probe to monitor binding of PET radiotracers in anesthetized mice in vivo, with high temporal resolution suited for compartmental modeling.
Abstract only
64
Background: Tumour immune response plays a critical role in progression and prognosis of EOC, however patterns of TILs and PD-L1 expression in primary and metastatic disease remain ...poorly described. Methods: Patients treated with neoadjuvant chemotherapy (NACT) for advanced EOC, between 2002-2014, and available sequential tumours (pre-NACT, post-NACT, or relapse) were retrospectively identified. Stromal TILs (sTILs) were evaluated according to the International TILs Working Group 2014 (Salgado 2015) on whole sections, and scored as a percentage of stromal area. Immune cell PD-L1 expression was evaluated by immunohistochemistry (E1L3N clone, Cell Signaling) in a smaller number of tumours. Cutoffs for analysis were: high sTILs ≥50%, PD-L1 positivity ≥5% membranous staining. Results: Among a total of 236 tumour samples from 150 patients (110 pre-NACT, 111 post-NACT, and 15 relapse tumours) median sTILs levels was significantly higher in metastatic tumours ( n=151) compared with primary tumours ( n=85) (median 30, IQR 10-50 vs. 15, IQR 5-30, p=0.0004). Among diagnostic samples, median sTILs level was 20 (IQR 10-45, n=85) in metastatic tumours compared with 10 (IQR 5-20, n =25) in primary tumours ( p=0064). Similarly in post-NACT samples, median sTILs level was 40 (IQR 15-60, n=51) in metastatic tumours compared with 20 (IQR 6.25-30, n=60) in primary tumours ( p=0026). Among relapse samples median sTILs level was 30 (IQR 10-50, n=15). Among all available samples ( n=97) PD-L1 positivity was detected in 33% (9/30) of primary and 50% (34/68) of metastatic tumours (Fisher’s exact test OR 2.3, 95%CI 0.94-5.4, p =0.08). Conclusions: In patients with EOC there is increased lymphocytic infiltration in both synchronous metastatic disease at diagnosis, and metachronous metastatic disease at relapse, compared with the primary tumour. This suggests increased immunogenicity as disease progresses. Furthermore, there is a trend towards upregulation of the PD-L1 immune checkpoint with disease progression.
A wastewater treatment system including a screen, a vermifilter, macrophytes ponds, and constructed wetlands has been built after a pig housing on slatted-floor. The aims were, all at once, to ...recycle water for excretion washing and to produce, from the nutrients contained in the effluent, organic matter and plants that can be either sold or reused on the farm to reduce inputs. Analyses, made on the effluent at different steps of the treatment plant, show that the concentrations of the nitrogen, microorganisms and endocrine disruptors are drastically reduced, while the phosphorus and potassium removal go through the byproducts harvesting.
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