acer

Indiana Pacers' first GM, architect of ABA championship teams Mike Storen dies at 84

Mike Storen, the Pacers' first general manager, former ABA commissioner and the father of ESPN broadcaster Hannah Storm, died Thursday. He was 84.

       




acer

Pacers Gaming kicks off NBA 2K League season on ESPN2

Pacers Gaming kicks off NBA 2K League season on ESPN2

       




acer

Indiana Pacers broadcast team nominated for regional Emmys

Indiana Pacers TV announcers Chris Denari and Quinn Buckner are among those up for honors

       




acer

'Last Dance' brings back memories of tough '90s NBA for Pacers coach Nate McMillan

'Last Dance' brings back memories of tough 90's NBA for Pacers coach Nate McMillan

       




acer

Indiana Pacers' first GM, architect of ABA championship teams Mike Storen dies at 84

Mike Storen, the Pacers' first general manager, former ABA commissioner and the father of ESPN broadcaster Hannah Storm, died Thursday. He was 84.

       




acer

'Definitely not the real thing': why eracers can't go from the bedroom to the cockpit

With more and more F1 drivers making the move to esports during the lockdown and doing well, could an expert sim racer easily make the leap the other way?




acer

Quantification of the affinities of CRISPR-Cas9 nucleases for cognate protospacer adȷacent motif (PAM) sequences [Molecular Biophysics]

The CRISPR/Cas9 nucleases have been widely applied for genome editing in various organisms. Cas9 nucleases complexed with a guide RNA (Cas9–gRNA) find their targets by scanning and interrogating the genomic DNA for sequences complementary to the gRNA. Recognition of the DNA target sequence requires a short protospacer adjacent motif (PAM) located outside this sequence. Given that the efficiency of target location may depend on the strength of interactions that promote target recognition, here we sought to compare affinities of different Cas9 nucleases for their cognate PAM sequences. To this end, we measured affinities of Cas9 nucleases from Streptococcus pyogenes, Staphylococcus aureus, and Francisella novicida complexed with guide RNAs (gRNAs) (SpCas9–gRNA, SaCas9–gRNA, and FnCas9–gRNA, respectively) and of three engineered SpCas9–gRNA variants with altered PAM specificities for short, PAM-containing DNA probes. We used a “beacon” assay that measures the relative affinities of DNA probes by determining their ability to competitively affect the rate of Cas9–gRNA binding to fluorescently labeled target DNA derivatives called “Cas9 beacons.” We observed significant differences in the affinities for cognate PAM sequences among the studied Cas9 enzymes. The relative affinities of SpCas9–gRNA and its engineered variants for canonical and suboptimal PAMs correlated with previous findings on the efficiency of these PAM sequences in genome editing. These findings suggest that high affinity of a Cas9 nuclease for its cognate PAM promotes higher genome-editing efficiency.




acer

Quantification of the affinities of CRISPR-Cas9 nucleases for cognate protospacer adȷacent motif (PAM) sequences [Molecular Biophysics]

The CRISPR/Cas9 nucleases have been widely applied for genome editing in various organisms. Cas9 nucleases complexed with a guide RNA (Cas9–gRNA) find their targets by scanning and interrogating the genomic DNA for sequences complementary to the gRNA. Recognition of the DNA target sequence requires a short protospacer adjacent motif (PAM) located outside this sequence. Given that the efficiency of target location may depend on the strength of interactions that promote target recognition, here we sought to compare affinities of different Cas9 nucleases for their cognate PAM sequences. To this end, we measured affinities of Cas9 nucleases from Streptococcus pyogenes, Staphylococcus aureus, and Francisella novicida complexed with guide RNAs (gRNAs) (SpCas9–gRNA, SaCas9–gRNA, and FnCas9–gRNA, respectively) and of three engineered SpCas9–gRNA variants with altered PAM specificities for short, PAM-containing DNA probes. We used a “beacon” assay that measures the relative affinities of DNA probes by determining their ability to competitively affect the rate of Cas9–gRNA binding to fluorescently labeled target DNA derivatives called “Cas9 beacons.” We observed significant differences in the affinities for cognate PAM sequences among the studied Cas9 enzymes. The relative affinities of SpCas9–gRNA and its engineered variants for canonical and suboptimal PAMs correlated with previous findings on the efficiency of these PAM sequences in genome editing. These findings suggest that high affinity of a Cas9 nuclease for its cognate PAM promotes higher genome-editing efficiency.




acer

Positron lymphography via intracervical 18F-FDG injection for pre-surgical lymphatic mapping in cervical and endometrial malignancies

Rationale: The presence of metastasis in local lymph nodes (LNs) is a key factor influencing choice of therapy and prognosis in cervical and endometrial cancers; therefore, the exploration of sentinel LNs (SLNs) is highly important. Currently, however, SLN mapping requires LN biopsy for pathologic evaluation, since there are no clinical imaging approaches that can identify tumor-positive LNs in early stages. Staging lymphadenectomy poses risks, such as leg lymphedema or lymphocyst formation. Furthermore, in 80% to 90% of patients, the explored LNs are ultimately tumor free, meaning the vast majority of patients are unnecessarily subjected to lymphadenectomy. Methods: Current lymphoscintigraphy methods only identify the anatomic location of the SLNs but do not provide information on their tumor status. There are no non-invasive methods to reliably identify metastases in LNs before surgery. We have developed positron lymphography (PLG), a method to detect tumor-positive LNs, where 18F-fluoro-2-deoxy-D-glucose (18F-FDG) is injected interstitially into the uterine cervix the day of surgery, and its rapid transport through the lymphatic vessels to the SLN is then visualized with dynamic positron emission tomography/computed tomography (PET/CT). We previously showed that PLG was able to identify metastatic LNs in animal models. Here, we present the first results from our pilot clinical trial (clinical trials identifier NCT02285192) in 23 patients with uterine or cervical cancer. On the morning of surgery, 18F-FDG was injected into the cervix, followed by an immediate dynamic PET/CT scan of the pelvis and a delayed 1-h whole body scan. Results: There were 3 (15%) node-positive cases on final pathologic analysis, and all LNs (including one with a focus of only 80 tumor cells) were identified by PLG except one node with an 11-mm micrometastasis. There were 2 (10%) false-positive cases with PLG, in which final pathology of the corresponding SLNs was negative for tumor. Methods: Current lymphoscintigraphy methods only identify the anatomic location of the SLNs but do not provide information on their tumor status. There are no non-invasive methods to reliably identify metastases in LNs before surgery. We have developed positron lymphography (PLG), a method to detect tumor-positive LNs, where 18F-fluoro-2-deoxy-D-glucose (18F-FDG) is injected interstitially into the uterine cervix the day of surgery, and its rapid transport through the lymphatic vessels to the SLN is then visualized with dynamic positron emission tomography/computed tomography (PET/CT). We previously showed that PLG was able to identify metastatic LNs in animal models. Here, we present the first results from our pilot clinical trial (clinical trials identifier NCT02285192) in 23 patients with uterine or cervical cancer. On the morning of surgery, 18F-FDG was injected into the cervix, followed by an immediate dynamic PET/CT scan of the pelvis and a delayed 1-h whole body scan. Results: There were 3 (15%) node-positive cases on final pathologic analysis, and all LNs (including one with a focus of only 80 tumor cells) were identified by PLG, except for one node with an 11-mm micrometastasis. There were 2 (10%) false-positive cases with PLG, in which final pathology of the corresponding SLNs was negative for tumor. Conclusion: This first-in-human study of PLG in women with uterine and cervical cancer demonstrates its feasibility and its ability to identify patients with nodal metastases, and warrants further evaluation in additional studies.




acer

Clinical Translation of a 68Ga-labeled Integrin {alpha}v{beta}6-targeting Cyclic Radiotracer for PET Imaging of Pancreatic Cancer

The overexpression of integrin αvβ6 in pancreatic cancer makes it a promising target for noninvasive positron emission tomography (PET) imaging. However, currently, most integrin αvβ6-targeting radiotracers are based on linear peptides, which are quickly degraded in the serum by proteinases. Herein, we aimed to develop and assess a 68Ga-labeled integrin αvβ6-targeting cyclic peptide (68Ga-cycratide) for PET imaging of pancreatic cancer. Methods: 68Ga-cycratide was prepared, and its PET imaging profile was compared with that of the linear peptide (68Ga-linear-pep) in an integrin αvβ6-positive BxPC-3 human pancreatic cancer mouse model. Five healthy volunteers (two women and three men) underwent whole-body PET/CT imaging after injection of 68Ga-cycratide, and biodistribution and dosimetry calculations were determined. PET/CT imaging of two patients was performed to investigate the potential role of 68Ga-cycratide in pancreatic cancer diagnosis and treatment monitoring. Results: 68Ga-cycratide exhibited significantly higher tumor uptake than did 68Ga-linear-pep in BxPC-3 tumor-bearing mice, owing—at least in part—to markedly improved in vivo stability. 68Ga-cycratide could sensitively detect the pancreatic cancer lesions in an orthotopic mouse model and was well tolerated in all healthy volunteers. Preliminary PET/CT imaging in patients with pancreatic cancer demonstrated that 68Ga-cycratide was comparable to 18F-fludeoxyglucose for diagnostic imaging and post-surgery tumor relapse monitoring. Conclusion: 68Ga-cycratide is an integrin αvβ6-specific PET radiotracer with favorable pharmacokinetics and dosimetry profile. 68Ga-cycratide is expected to provide an effective noninvasive PET strategy for pancreatic cancer lesion detection and therapy response monitoring.




acer

Development and evaluation of interleukin-2 derived radiotracers for PET imaging of T-cells in mice

Recently, N-(4-18F-fluorobenzoyl)-interleukin-2 (18F-FB-IL2) was introduced as PET tracer for T-cell imaging. However, production is complex and time-consuming. Therefore, we developed two radiolabeled interleukin-2 (IL-2) variants, namely aluminum 18F-fluoride-(restrained complexing agent)-IL-2 (18F-AlF-RESCA-IL2) and 68Ga-gallium-(1,4,7-triazacyclononane-4,7-diacetic acid-1-glutaric acid)-IL-2 (68Ga-Ga-NODAGA-IL2) and compared their in-vitro and in-vivo characteristics with 18F-FB-IL2. Methods: Radiolabeling of 18F-AlF-RESCA-IL2 and 68Ga-Ga-NODAGA-IL2 was optimized and stability was evaluated in human serum. Receptor binding was studied with activated human peripheral blood mononuclear cells (hPBMCs). Ex-vivo tracer biodistribution in immunocompetent BALB/cOlaHsd (BALB/c) mice was performed at 15, 60 and 90 min after tracer injection. In-vivo binding characteristics were studied in severe combined immune-deficient (SCID) mice inoculated with activated hPBMCs in Matrigel. Tracer was injected 15 min after hPBMCs inoculation and a 60-min dynamic PET scan was acquired, followed by ex-vivo biodistribution studies. Specific uptake was determined by co-injection of tracer with unlabeled IL2 and by evaluating uptake in a control group inoculated with Matrigel only. Results: 68Ga-Ga-NODAGA-IL2 and 18F-AlF-RESCA-IL2 were produced with radiochemical purity >95% and radiochemical yield of 13.1±4.7% and 2.4±1.6% within 60 and 90 min, respectively. Both tracers were stable in serum, with >90% being intact tracer after 1h. In-vitro, both tracers displayed preferential binding to activated hPBMCs. Ex-vivo biodistribution studies in BALB/c mice showed higher uptake of 18F-AlF-RESCA-IL2 than 18F-FB-IL2 in liver, kidney, spleen, bone and bone marrow. 68Ga-Ga-NODAGA-IL2 uptake in liver and kidney was higher than 18F-FB-IL2 uptake. In-vivo, all tracers revealed uptake in activated hPBMCs in SCID mice. Low uptake was seen after a blocking dose of IL2 or in the Matrigel control group. In addition, 18F-AlF-RESCA-IL2 yielded highest contrast PET images of target lymph nodes. Conclusion: Production of 18F-AlF-RESCA-IL2 and 68Ga-Ga-NODAGA-IL2 is simpler and faster than 18F-FB-IL2. Both tracers showed good in-vitro and in-vivo characteristics with high uptake in lymphoid tissue and hPBMC xenografts.




acer

Digital Solid-State SPECT/CT Quantitation of Absolute 177Lu-Radiotracer Concentration: In Vivo/In Vitro Validation

The accuracy of lutetium-177 (177Lu) radiotracer concentration measurements using quantitative clinical software was determined by comparing in vivo results for a digital solid-state cadmium-zinc-telluride SPECT/CT (single photon emission computed tomography / x-ray computed tomography) system to in vitro sampling. First, image acquisition parameters were assessed for an International Electrotechnical Commission (IEC) body phantom emulating clinical count rates loaded with a "lung" insert and 6 hot spheres with a 12:1 target-to-background ratio of 177Lu solution. Then, the data of 28 whole-body SPECT/CT scans of 7 patients who underwent 177Lu prostate membrane antigen (177Lu-PSMA) radioligand therapy was retrospectively analyzed. Three users analyzed SPECT/CT images for in vivo urinary bladder radiotracer uptake using quantitative software (Q.Metrix, GE Healthcare). In vitro radiopharmaceutical concentrations were calculated using urine sampling obtained immediately after each scan, scaled to standardized uptake values (SUVs). Any in vivo/in vitro identity relations were determined by linear regression (ideally slope=1, intercept=0), within a 95 % confidence interval (CI). Phantom results demonstrated lower quantitative error for acquisitions using the 113 keV 177Lu energy peak rather than including the 208 keV peak, given that only low-energy collimation was available in this camera configuration. In the clinical study, 24 in vivo/in vitro pairs were eligible for further analysis, having rejected 4 as outliers (via Cook’s distance calculations). All linear regressions (R2 ≥ 0.92, P<0.0001) provided identity in vivo/in vitro relations (95 % CI), with SUV averages from all users giving a slope of 1.03±0.09, an intercept of –0.25±0.64 g/mL, and an average residual difference of 20.4 %. Acquiring with the lower energy 177Lu energy peak, solid-state SPECT/CT imaging provides an accuracy to within ~20 % for in vivo urinary bladder radiotracer concentrations. This non-invasive in vivo quantitation method can potentially improve diagnosis, improve patient management and treatment response assessment, and provide data essential to 177Lu dosimetry.




acer

Kinetic modeling and test-retest reproducibility of 11C-EKAP and 11C-FEKAP, novel agonist radiotracers for PET imaging of the kappa opioid receptor in humans

The kappa opioid receptor (KOR) is implicated in various neuropsychiatric disorders. We previously evaluated an agonist tracer, 11C-GR103545, for PET imaging of KOR in humans. Although 11C-GR103545 showed high brain uptake, good binding specificity, and selectivity to KOR, it displayed slow kinetics and relatively large test-retest variability (TRV) of distribution volume (VT) estimates (15%). Therefore we set out to develop two novel KOR agonist radiotracers, 11C-EKAP and 11C-FEKAP, and in nonhuman primates, both tracers exhibited faster kinetics and comparable binding parameters to 11C-GR103545. The aim of this study was to assess their kinetic and binding properties in humans. Methods: Six healthy subjects underwent 120-min test-retest PET scans with both 11C-EKAP and 11C-FEKAP. Metabolite-corrected arterial input functions were measured. Regional time-activity curves (TACs) were generated for 14 regions of interest. One- and two-tissue compartment models (1TC, 2TC) and the multilinear analysis-1 (MA1) method were applied to the regional TACs to calculate VT. Time-stability of VT values and test-retest reproducibility were evaluated. Levels of specific binding, as measured by the non-displaceable binding potential (BPND) for the three tracers (11C-EKAP, 11C-FEKAP and 11C-GR103545), were compared using a graphical method. Results: For both tracers, regional TACs were fitted well with the 2TC model and MA1 method (t*=20min), but not with the 1TC model. Given unreliably estimated parameters in several fits with the 2TC model and a good match between VT values from MA1 and 2TC, MA1 was chosen as the appropriate model for both tracers. Mean MA1 VT values were highest for 11C-GR103545, followed by 11C-EKAP, then 11C-FEKAP. Minimum scan time for stable VT measurement was 90 and 110min for 11C-EKAP and 11C-FEKAP, respectively, compared with 140min for 11C-GR103545. The mean absolute TRV in MA1 VT estimates was 7% and 18% for 11C-EKAP and 11C-FEKAP, respectively. BPND levels were similar for 11C-FEKAP and 11C-GR103545, but ~25% lower for 11C-EKAP. Conclusion: The two novel KOR agonist tracers showed faster tissue kinetics than 11C-GR103545. Even with slightly lower BPND, 11C-EKAP is judged to be a better tracer for imaging and quantification of KOR in humans, based on the shorter minimum scan time and excellent test-retest.




acer

First-in-Human Trial of Dasatinib-Derivative Tracer for Tumor Kinase-Targeted Positron Emission Tomography

We developed a first-of-kind dasatinib-derivative imaging agent, 18F-SKI-249380 (18F-SKI), and validated its use for noninvasive in vivo tyrosine kinase-targeted tumor detection in preclinical models. In this study, we assess the feasibility of using 18F-SKI for PET imaging in patients with malignancies. Methods: Five patients with a prior diagnosis of breast cancer, renal cell cancer, or leukemia underwent whole-body PET/CT imaging 90 min post-injection of 18F-SKI (mean: 241.24 ± 116.36 MBq) as part of a prospective study. In addition, patients underwent either a 30-min dynamic scan of the upper abdomen including, at least partly, cardiac left ventricle, liver, spleen, and kidney (n = 2) or three 10-min whole-body PET/CT scans (n = 3) immediately post-injection and blood-based radioactivity measurements to determine the time course of tracer distribution and facilitate radiation dose estimates. A subset of three patients had a delayed whole-body PET/CT scan at 180 min. Biodistribution, dosimetry, and tumor uptake were quantified. Absorbed doses were calculated using OLINDA/EXM 1.0. Results: No adverse events occurred after injection of 18F-SKI. A total of 27 tumor lesions were analyzed with median SUVpeak 1.4 (range, 0.7–2.3) and tumor-to-blood ratios of 1.6 (range, 0.8–2.5) at 90 min post-injection. Intratumoral drug concentrations calculated for four reference lesions ranged from 0.03–0.07 nM. In all reference lesions, constant tracer accumulation was observed between 30–90 min post-injection. Blood radio-assay indicated that radiotracer clearance from blood and plasma was initially rapid (blood half-time 1.31 ± 0.81 min, plasma 1.07 ± 0.66 min; n = 4), followed variably by either a prolonged terminal phase (blood half-time 285 ± 148.49 min, plasma 240 ± 84.85 min; n = 2) or a small rise to plateau (n = 2). Like dasatinib, 18F-SKI underwent extensive metabolism post-administration, as evidenced by metabolite analysis. Radioactivity was predominantly cleared via the hepatobiliary route. The highest absorbed dose estimates (mGy/MBq) in normal tissues were to the right colon (0.167 ± 0.04) and small intestine (0.153 ± 0.03). The effective dose was 0.0258 (SD 0.0034) mSv/MBq. Conclusion: 18F-SKI demonstrated significant tumor uptake, distinct image contrast despite low injected doses, and rapid clearance from blood.




acer

Design and development of 99mTc labeled FAPI-tracers for SPECT-imaging and 188Re therapy.

The majority of epithelial tumors recruits fibroblasts and other non-malignant cells and activates them into cancer-associated fibroblasts. This often leads to overexpression of the membrane serine protease fibroblast-activating protein (FAP). It has already been shown that DOTA-bearing FAP inhibitors (FAPIs) generate high contrast images with PET/CT scans. Since SPECT is a lower cost and more widely available alternative to PET, 99mTc-labeled FAPIs represent attractive tracers for imaging applicable in a larger number of patients. Furthermore, the chemically homologous nuclide 188Re is available from generators, which allows FAP-targeted endoradiotherapy. Methods: For the preparation of 99mTc tricarbonyl complexes, a chelator was selected whose carboxylic acids can easily be converted into various derivatives in the finished product. This enabled a platform strategy based on the original tracer. The obtained 99mTc complexes were investigated in vitro by binding and competition experiments on FAP-transfected HT-1080 (HT-1080-FAP) and/or on mouse FAP expressing (HEK-muFAP) and CD26-expressing (HEKCD26) HEK cells and characterized by planar scintigraphy and organ distribution studies in tumor-bearing mice. Furthermore, a first-in-man application was done in two patients with ovarian and pancreatic cancer, respectively. Results: 99mTc-FAPI-19 showed specific binding to recombinant FAP-expressing cells with high affinity. Unfortunately, liver accumulation, biliary excretion and no tumor uptake were observed in the planar scintigraphy of a HT-1080-FAP xenotranplanted mouse. To improve the pharmacokinetic properties hydrophilic amino acids were attached to the chelator moiety of the compound. The resulting 99mTc-labeled FAPI tracers revealed excellent binding properties (up to 45 % binding; above 95 % internalization), high affinity (IC50 = 6.4 nM to 12.7 nM), and significant tumor uptake (up to 5.4 %ID/g) in biodistribution studies. The lead candidate 99mTc-FAPI-34 was applied for diagnostic scintigraphy and SPECT of patients with metastasized ovarian and pancreatic cancer for follow-up to therapy with 90Y-FAPI-46. 99mTc-FAPI-34 accumulated in the tumor lesions also shown in PET/CT imaging using 68Ga-FAPI-46. Conclusion: 99mTc-FAPI-34 represents a powerful tracer for diagnostic scintigraphy, especially in cases where PET imaging is not available. Additionally, the chelator used in this compound allows labeling with the therapeutic nuclide 188Re which is planned for the near future.




acer

11C-PABA as a Novel PET Radiotracer for Functional Renal Imaging: Preclinical and First-in-Human Studies

para-Aminobenzoic acid (PABA) has been previously used as an exogenous marker to verify completion of 24-hour urine sampling. Therefore, we hypothesized that radiolabeled PABA with 11C could allow high-quality dynamic PET of the kidneys while reducing the radiation exposure due to its short biological and physical half-lives. We evaluated if 11C-PABA could visualize renal anatomy and quantify function in healthy rats, rabbits, and first-in-human studies in healthy volunteers. Methods: Healthy rats and rabbits were injected with 11C-PABA intravenously. Subsequently, a dynamic PET was performed, followed by post-mortem tissue biodistribution studies. 11C-PABA PET was directly compared with the current standard, 99mTc-MAG3 in rats. Three healthy human subjects also underwent dynamic PET after intravenous injection of 11C-PABA. Results: In healthy rats and rabbits, dynamic PET demonstrated a rapid accumulation of 11C-PABA in the renal cortex, followed by rapid excretion through the pelvicalyceal system. In humans, 11C-PABA PET was safe and well tolerated. There were no adverse or clinically detectable pharmacologic effects in any subject. The cortex was delineated on PET, and the activity gradually transited to the medulla and then renal pelvis with high spatiotemporal resolution. Conclusion: 11C-PABA demonstrated fast renal excretion with very low background signal in animals and humans. These results suggest that 11C-PABA could be used as a novel radiotracer for functional renal imaging, providing high-quality spatiotemporal images with low radiation exposure.




acer

Molecular imaging of PD-L1 expression and dynamics with the adnectin-based PET tracer 18F-BMS-986192

18F-BMS-986192, an adnectin-based human programmed cell death ligand 1 (PD-L1) tracer, was developed to non-invasively determine whole-body PD-L1 expression by positron emission tomography (PET). We evaluated usability of 18F-BMS-986192 PET to detect different PD-L1 expression levels and therapy-induced changes of PD-L1 expression in tumors. Methods: In vitro binding assays with 18F-BMS-986192 were performed in human tumor cell lines with different total cellular and membrane PD-L1 protein expression levels. Subsequently, PET imaging was executed in immunodeficient mice xenografted with these cell lines. Mice were treated with interferon gamma (IFN) intraperitoneally for 3 days or with the mitogen-activated protein kinase kinase (MEK1/2) inhibitor selumetinib by oral gavage for 24 hours. Thereafter 18F-BMS-986192 was administered intravenously, followed by a 60-minute dynamic PET scan. Tracer uptake was expressed as percentage injected dose per gram tissue (%ID/g). Tissues were collected to evaluate ex vivo tracer biodistribution and to perform flow cytometric, Western blot, and immunohistochemical tumor analyses. Results: 18F-BMS-986192 uptake reflected PD-L1 membrane levels in tumor cell lines, and tumor tracer uptake in mice was associated with PD-L1 expression measured immunohistochemically. In vitro IFN treatment increased PD-L1 expression in the tumor cell lines and caused up to 12-fold increase in tracer binding. In vivo, IFN did neither affect PD-L1 tumor expression measured immunohistochemically nor 18F-BMS-986192 tumor uptake. In vitro, selumetinib downregulated cellular and membrane levels of PD-L1 of tumor cells by 50% as measured by Western blotting and flow cytometry. In mice, selumetinib lowered cellular, but not membrane PD-L1 levels of tumors and consequently no treatment-induced change in 18F-BMS-986192 tumor uptake was observed. Conclusion: 18F-BMS-986192 PET imaging allows detection of membrane-expressed PD-L1, as soon as 60 minutes after tracer injection. The tracer can discriminate a range of tumor cell PD-L1 membrane expression levels.




acer

The effects of monosodium glutamate on PSMA radiotracer uptake in men with recurrent prostate cancer: a prospective, randomized, double-blind, placebo-controlled intra-individual imaging study.

The prostate-specific membrane antigen (PSMA) is an excellent target for theranostic applications in prostate cancer (PCa). However, PSMA-targeted radioligand therapy can cause undesirable effects due to high accumulation of PSMA radiotracers in salivary glands and kidneys. This study assessed orally administered monosodium glutamate (MSG) as a potential means of reducing kidney and salivary gland radiation exposure using a PSMA targeting radiotracer. Methods: This prospective, double-blind, placebo-controlled study enrolled 10 biochemically recurrent PCa patients. Each subject served as his own control. [18F]DCFPyl PET/CT imaging sessions were performed 3 – 7 days apart, following oral administration of either 12.7 g of MSG or placebo. Data from the two sets of images were analyzed by placing regions of interest on lacrimal, parotid and submandibular glands, left ventricle, liver, spleen, kidneys, bowel, urinary bladder, gluteus muscle and malignant lesions. The results from MSG and placebo scans were compared by paired analysis of the ROI data. Results: A total of 142 pathological lesions along with normal tissues were analyzed. As hypothesized a priori, there was a significant decrease in maximal standardized uptake values corrected for lean body mass (SULmax) on images obtained following MSG administration in the parotids (24 ± 14%, P = 0.001), submandibular glands (35 ± 11%, P<0.001) and kidneys (23 ± 26%, P = 0.014). Significant decreases were also observed in lacrimal glands (49 ± 13%, P<0.001), liver (15 ± 6%, P<0.001), spleen (28 ± 13%, P = 0.001) and bowel (44 ± 13%, P<0.001). Mildly lower blood pool SULmean was observed after MSG administration (decrease of 11 ± 13%, P = 0.021). However, significantly lower radiotracer uptake in terms of SULmean, SULpeak, and SULmax was observed in malignant lesions on scans performed after MSG administration compared to the placebo studies (SULmax median decrease 33%, range -1 to 75%, P<0.001). No significant adverse events occurred and vital signs were stable following placebo or MSG administration. Conclusion: Orally administered MSG significantly decreased salivary gland, kidney and other normal organ PSMA radiotracer uptake in human subjects, using [18F]DCFPyL as an exemplar. However, MSG caused a corresponding reduction in tumor uptake, which may limit the benefits of this approach for diagnostic and therapeutic applications.




acer

Branched-Chain Amino Acids Exacerbate Obesity-Related Hepatic Glucose and Lipid Metabolic Disorders via Attenuating Akt2 Signaling

Branched chain amino acids (BCAAs) are associated with the progression of obesity-related metabolic disorders, including T2DM and non-alcoholic fatty liver disease. However, whether BCAAs disrupt the homeostasis of hepatic glucose and lipid metabolism remains unknown. In this study, we observed that BCAAs supplementation significantly reduced high-fat (HF) diet-induced hepatic lipid accumulation while increasing the plasma lipid levels and promoting muscular and renal lipid accumulation. Further studies demonstrated that BCAAs supplementation significantly increased hepatic gluconeogenesis and suppressed hepatic lipogenesis in HF diet-induced obese (DIO) mice. These phenotypes resulted from severe attenuation of Akt2 signaling via mTORC1- and mTORC2-dependent pathways. BCAAs/branched-chain α-keto acids (BCKAs) chronically suppressed Akt2 activation through mTORC1 and mTORC2 signaling and promoted Akt2 ubiquitin-proteasome-dependent degradation through the mTORC2 pathway. Moreover, the E3 ligase Mul1 played an essential role in BCAAs/BCKAs-mTORC2-induced Akt2 ubiquitin-dependent degradation. We also demonstrated that BCAAs inhibited hepatic lipogenesis by blocking Akt2/SREBP1/INSIG2a signaling and increased hepatic glycogenesis by regulating Akt2/Foxo1 signaling. Collectively, these data demonstrate that in DIO mice, BCAAs supplementation resulted in serious hepatic metabolic disorder and severe liver insulin resistance: insulin failed to not only suppress gluconeogenesis but also activate lipogenesis. Intervening BCAA metabolism is a potential therapeutic target for severe insulin-resistant disease.




acer

Diagnostic Accuracy of PET Tracers for the Differentiation of Tumor Progression from Treatment-Related Changes in High-Grade Glioma: A Systematic Review and Metaanalysis

Posttreatment high-grade gliomas are usually monitored with contrast-enhanced MRI, but its diagnostic accuracy is limited as it cannot adequately distinguish between true tumor progression and treatment-related changes. According to recent Response Assessment in Neuro-Oncology recommendations, PET overcomes this limitation. However, it is currently unknown which tracer yields the best results. Therefore, a systematic review and metaanalysis were performed to compare the diagnostic accuracy of the different PET tracers in differentiating tumor progression from treatment-related changes in high-grade glioma patients. Methods: PubMed, Web of Science, and Embase were searched systematically. Study selection, data extraction, and quality assessment were performed independently by 2 authors. Metaanalysis was performed using a bivariate random-effects model when at least 5 studies were included. Results: The systematic review included 39 studies (11 tracers). 18F-FDG (12 studies, 171 lesions) showed a pooled sensitivity and specificity of 84% (95% confidence interval, 72%–92%) and 84% (95% confidence interval, 69%–93%), respectively. O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) (7 studies, 172 lesions) demonstrated a sensitivity of 90% (95% confidence interval, 81%–95%) and specificity of 85% (95% confidence interval, 71%–93%). For S-11C-methyl)-l-methionine (11C-MET) (8 studies, 151 lesions), sensitivity was 93% (95% confidence interval, 80%–98%) and specificity was 82% (95% confidence interval, 68%–91%). The numbers of included studies for the other tracers were too low to combine, but sensitivity and specificity ranged between 93%–100% and 0%–100%, respectively, for 18F-FLT; 85%–100% and 72%–100%, respectively, for 3,4-dihydroxy-6-18F-fluoro-l-phenylalanine (18F-FDOPA); and 100% and 70%–88%, respectively, for 11C-choline. Conclusion: 18F-FET and 11C-MET, both amino-acid tracers, showed a comparably higher sensitivity than 18F-FDG in the differentiation between tumor progression and treatment-related changes in high-grade glioma patients. The evidence for other tracers is limited; thus, 18F-FET and 11C-MET are preferred when available. Our results support the incorporation of amino-acid PET tracers for the treatment evaluation of high-grade gliomas.




acer

Secessions Exacerbate Segregation, Study Finds

Court-ordered school desegregation has been more successful in the South than in any other region of the country, but researchers have noted a new threat: the growing number of communities that are seceding from larger school districts to form their own.




acer

Secessions Exacerbate Segregation, Study Finds

Court-ordered school desegregation has been more successful in the South than in any other region of the country, but researchers have noted a new threat: the growing number of communities that are seceding from larger school districts to form their own.




acer

Striatal Nurr1 Facilitates the Dyskinetic State and Exacerbates Levodopa-Induced Dyskinesia in a Rat Model of Parkinson's Disease

The transcription factor Nurr1 has been identified to be ectopically induced in the striatum of rodents expressing l-DOPA-induced dyskinesia (LID). In the present study, we sought to characterize Nurr1 as a causative factor in LID expression. We used rAAV2/5 to overexpress Nurr1 or GFP in the parkinsonian striatum of LID-resistant Lewis or LID-prone Fischer-344 (F344) male rats. In a second cohort, rats received the Nurr1 agonist amodiaquine (AQ) together with l-DOPA or ropinirole. All rats received a chronic DA agonist and were evaluated for LID severity. Finally, we performed single-unit recordings and dendritic spine analyses on striatal medium spiny neurons (MSNs) in drug-naïve rAAV-injected male parkinsonian rats. rAAV-GFP injected LID-resistant hemi-parkinsonian Lewis rats displayed mild LID and no induction of striatal Nurr1 despite receiving a high dose of l-DOPA. However, Lewis rats overexpressing Nurr1 developed severe LID. Nurr1 agonism with AQ exacerbated LID in F344 rats. We additionally determined that in l-DOPA-naïve rats striatal rAAV-Nurr1 overexpression (1) increased cortically-evoked firing in a subpopulation of identified striatonigral MSNs, and (2) altered spine density and thin-spine morphology on striatal MSNs; both phenomena mimicking changes seen in dyskinetic rats. Finally, we provide postmortem evidence of Nurr1 expression in striatal neurons of l-DOPA-treated PD patients. Our data demonstrate that ectopic induction of striatal Nurr1 is capable of inducing LID behavior and associated neuropathology, even in resistant subjects. These data support a direct role of Nurr1 in aberrant neuronal plasticity and LID induction, providing a potential novel target for therapeutic development.

SIGNIFICANCE STATEMENT The transcription factor Nurr1 is ectopically induced in striatal neurons of rats exhibiting levodopa-induced dyskinesia [LID; a side-effect to dopamine replacement strategies in Parkinson's disease (PD)]. Here we asked whether Nurr1 is causing LID. Indeed, rAAV-mediated expression of Nurr1 in striatal neurons was sufficient to overcome LID-resistance, and Nurr1 agonism exacerbated LID severity in dyskinetic rats. Moreover, we found that expression of Nurr1 in l-DOPA naïve hemi-parkinsonian rats resulted in the formation of morphologic and electrophysiological signatures of maladaptive neuronal plasticity; a phenomenon associated with LID. Finally, we determined that ectopic Nurr1 expression can be found in the putamen of l-DOPA-treated PD patients. These data suggest that striatal Nurr1 is an important mediator of the formation of LID.




acer

Queda mucho por hacer para detener el declive de Zimbabue

Un año después de la victoria en las elecciones de la Unión Nacional Africana de Zimbabue- Frente Patriótico (ZANU-PF, en sus siglas en inglés) y de la formación de un nuevo gobierno, la política y la economía de Zimbabue son cada vez más precarias. Las perspectivas inmediatas de una recuperación sostenida siguen siendo malas, empeoradas por el alarmante declive económico, los fracasos endémicos en materia de gobernanza y la tensión generada por la sucesión en el partido en el poder.




acer

Secessions Exacerbate Segregation, Study Finds

Court-ordered school desegregation has been more successful in the South than in any other region of the country, but researchers have noted a new threat: the growing number of communities that are seceding from larger school districts to form their own.




acer

Correlation of Care Process Measures With Childhood Asthma Exacerbations

Asthma is a common focus of pediatric quality improvement efforts. Various processes of care have been postulated as markers of high-quality pediatric asthma care, but it is not clear which processes correlate with a lower risk of asthma exacerbations.

This study analyzed the correlation of processes of care identifiable through administrative data with asthma exacerbations. The use of 0 vs ≥1 controller medications and the asthma medication ratio had the strongest correlation with asthma exacerbations. (Read the full article)




acer

Medical Home Quality and Readmission Risk for Children Hospitalized With Asthma Exacerbations

The medical home likely plays a positive role in outpatient health outcomes. Asthma is a common and frequent reason for pediatric hospitalization. It is unknown whether having a quality medical home can prevent readmission in children hospitalized for asthma exacerbations.

Poor access to a medical home was associated with increased readmission for asthma, whereas other measured aspects of medical home were not. Children with private insurance and good access to care had the lowest rates of readmission within a year. (Read the full article)




acer

Deals: Acer Computers, Blink XT2, 65-Inch Vizio P-Series Quantum X

Amazon is offering up to 30 percent off Acer laptops, desktops, and monitors. Plus, you can save $930 on the 65-inch Vizio P-Series Quantum X 4K TV.




acer

Acer Predator CG437K

While Acer's Predator CG437K aims for the stars with its impressive feature set, this gaming monitor's achievements aren't as lofty as its goals. Some gamers may be willing to sacrifice picture quality for its size, but others should save their money and look at alternatives.




acer

Acer Aspire TC-885-UA92

The Acer Aspire TC-885-UA92 is our top pick among budget desktops for its excellent value, delivering speedy performance and a solid feature set at a very reasonable price.




acer

Flipped Classrooms May Exacerbate Student Achievement Gaps. Here's How

Flipped classrooms have been getting attention as a way for teachers to find more time for activities and individual support during the regular school day, but a new study cautions that the model could trade short-term gains for wider achievement gaps.




acer

Royal Enfield Continental GT 650 custom built as ’90s endurance racer in just six weeks




acer

Now hiring: New York looking for thousands of contact tracers to slow COVID-19 spread

New York has embarked on a program to use thousands of 'contact tracers' to track the spread of the novel coronavirus and contain its reach. ......




acer

Coronavirus exacerbating ''disordered world'' warns EU's top diplomat

Coronavirus exacerbating ''disordered world'' warns EU's top diplomat




acer

What is it like to be a covid-19 contact tracer and what do they do?

Covid-19 contact tracers are part healthcare worker, part detective and part call centre operative. But what is the job really like? New Scientist spoke to one in Ireland to find out




acer

UK sets new target to recruit 18,000 contact tracers by mid-May

The UK government has set a new target of recruiting an army of 18,000 coronavirus contact tracers by the middle of May, to be in place for the launch of the NHS contact tracing app




acer

UK government won't say how many covid-19 contact tracers it has hired

The UK government has refused to say how many covid-19 contact tracers it has employed, with less than three weeks to go until its target of recruiting 18,000 of them by mid-May




acer

Quantification of the affinities of CRISPR-Cas9 nucleases for cognate protospacer ad&#x0237;acent motif (PAM) sequences [Molecular Biophysics]

The CRISPR/Cas9 nucleases have been widely applied for genome editing in various organisms. Cas9 nucleases complexed with a guide RNA (Cas9–gRNA) find their targets by scanning and interrogating the genomic DNA for sequences complementary to the gRNA. Recognition of the DNA target sequence requires a short protospacer adjacent motif (PAM) located outside this sequence. Given that the efficiency of target location may depend on the strength of interactions that promote target recognition, here we sought to compare affinities of different Cas9 nucleases for their cognate PAM sequences. To this end, we measured affinities of Cas9 nucleases from Streptococcus pyogenes, Staphylococcus aureus, and Francisella novicida complexed with guide RNAs (gRNAs) (SpCas9–gRNA, SaCas9–gRNA, and FnCas9–gRNA, respectively) and of three engineered SpCas9–gRNA variants with altered PAM specificities for short, PAM-containing DNA probes. We used a “beacon” assay that measures the relative affinities of DNA probes by determining their ability to competitively affect the rate of Cas9–gRNA binding to fluorescently labeled target DNA derivatives called “Cas9 beacons.” We observed significant differences in the affinities for cognate PAM sequences among the studied Cas9 enzymes. The relative affinities of SpCas9–gRNA and its engineered variants for canonical and suboptimal PAMs correlated with previous findings on the efficiency of these PAM sequences in genome editing. These findings suggest that high affinity of a Cas9 nuclease for its cognate PAM promotes higher genome-editing efficiency.




acer

Radiohybrid Ligands: A Novel Tracer Concept Exemplified by 18F- or 68Ga-Labeled rhPSMA Inhibitors

When we critically assess the reason for the current dominance of 68Ga-labeled peptides and peptide-like ligands in radiopharmacy and nuclear medicine, we have to conclude that the major advantage of such radiopharmaceuticals is the apparent lack of suitable 18F-labeling technologies with proven clinical relevance. To prepare and to subsequently perform a clinical proof-of-concept study on the general suitability of silicon-fluoride-acceptor (SiFA)–conjugated radiopharmaceuticals, we developed inhibitors of the prostate-specific membrane antigen (PSMA) that are labeled by isotopic exchange (IE). To compensate for the pronounced lipophilicity of the SiFA unit, we used metal chelates, conjugated in close proximity to SiFA. Six different radiohybrid PSMA ligands (rhPSMA ligands) were evaluated and compared with the commonly used 18F-PSMA inhibitors 18F-DCFPyL and 18F-PSMA-1007. Methods: All inhibitors were synthesized by solid-phase peptide synthesis. Human serum albumin binding was measured by affinity high-performance liquid chromatography, whereas the lipophilicity of each tracer was determined by the n-octanol/buffer method. In vitro studies (IC50, internalization) were performed on LNCaP cells. Biodistribution studies were conducted on LNCaP tumor–bearing male CB-17 SCID mice. Results: On the laboratory scale (starting activities, 0.2–9.0 GBq), labeling of 18F-rhPSMA-5 to -10 by IE was completed in < 20 min (radiochemical yields, 58% ± 9%; radiochemical purity, >97%) with molar activities of 12–60 GBq/μmol. All rhPSMAs showed low nanomolar affinity and high internalization by PSMA-expressing cells when compared with the reference radiopharmaceuticals, medium-to-low lipophilicity, and high human serum albumin binding. Biodistribution studies in LNCaP tumor–bearing mice revealed high tumor uptake, sufficiently fast clearance kinetics from blood, low hepatobiliary excretion, fast renal excretion, and very low uptake of 18F activity in bone. Conclusion: The novel 18F-rhPSMA radiopharmaceuticals developed under the radiohybrid concept show equal or better targeting characteristics than the established 18F-PSMA tracers 18F-DCFPyL and 18F-PSMA-1007. The unparalleled simplicity of production, the possibility to produce the identical 68Ga-labeled 19F-68Ga-rhPSMA tracers, and the possibility to extend this concept to true theranostic radiohybrid radiopharmaceuticals, such as F-Lu-rhPSMA, are unique features of these radiopharmaceuticals.




acer

Imaging Responses to Immunotherapy with Novel PET Tracers




acer

Management of acute COPD exacerbations in Australia: do we follow the guidelines?

Objective

We aimed to assess adherence to the Australian national guideline (COPD-X) against audited practice, and to document the outcomes of patients hospitalised with an acute exacerbation of chronic obstructive pulmonary disease (COPD) at discharge and 28 days after.

Methods

A prospective clinical audit of COPD hospital admission from five tertiary care hospitals in five states of Australia was conducted. Post-discharge follow-up was conducted via telephone to assess for readmission and health status.

Results

There were 207 admissions for acute exacerbation (171 patients; mean 70.2 years old; 50.3% males). Readmission rates at 28 days were 25.4%, with one (0.6%) death during admission and eight (6.1%) post-discharge within 28 days. Concordance to the COPD-X guidance was variable; 22.7% performed spirometry, 81.1% had blood gases collected when forced expiratory volume in 1 s was <1 L, 99.5% had chest radiography performed, 95.1% were prescribed systemic corticosteroids and 95% were prescribed antibiotic therapy. There were 89.1% given oxygen therapy and 92.6% when arterial oxygen tension was <80 mmHg; 65.6% were given ventilatory assistance when pH was <7.35. Only 32.4% were referred to pulmonary rehabilitation but 76.8% had general practitioner follow-up arranged.

Conclusion

When compared against clinical practice guidelines, we found important gaps in management of patients admitted with COPD throughout tertiary care centres in Australia. Strategies to improve guideline uptake are needed to optimise care.




acer

What is it like to be a covid-19 contact tracer and what do they do?

Covid-19 contact tracers are part healthcare worker, part detective and part call centre operative. But what is the job really like? New Scientist spoke to one in Ireland to find out




acer

UK sets new target to recruit 18,000 contact tracers by mid-May

The UK government has set a new target of recruiting an army of 18,000 coronavirus contact tracers by the middle of May, to be in place for the launch of the NHS contact tracing app




acer

UK government won't say how many covid-19 contact tracers it has hired

The UK government has refused to say how many covid-19 contact tracers it has employed, with less than three weeks to go until its target of recruiting 18,000 of them by mid-May




acer

Acer gaming laptops add RTX Super graphics and 10th-gen Intel CPUs

Acer is joining a flurry of PC makers in adopting the next wave of NVIDIA and Intel chips inside its laptops. It's updating its 15.6-inch Predator Triton 500 (above) and Nitro 5 (below) gaming portables to use NVIDIA's new GeForce RTX Super laptop GPUs as well as Intel's 10th-generation Core H-series processors. As you might guess, the premium Predator series is the highlight. It comes with up to a GeForce RTX 2080 Super Max-Q to deliver speedier and more efficient graphics, and mates that with a 300Hz, 3ms response IPS display and per-key RGB keyboard lighting.




acer

'A tracing army': As they reopen, states look to contact tracers in COVID-19 fight

As more states reopen, an army of contact tracers will have to be enlisted to join the effort to stop the coronavirus.




acer

Real-time observation of CRISPR spacer acquisition by Cas1–Cas2 integrase




acer

What is it like to be a covid-19 contact tracer and what do they do?

Covid-19 contact tracers are part healthcare worker, part detective and part call centre operative. But what is the job really like? New Scientist spoke to one in Ireland to find out




acer

UK sets new target to recruit 18,000 contact tracers by mid-May

The UK government has set a new target of recruiting an army of 18,000 coronavirus contact tracers by the middle of May, to be in place for the launch of the NHS contact tracing app




acer

UK government won't say how many covid-19 contact tracers it has hired

The UK government has refused to say how many covid-19 contact tracers it has employed, with less than three weeks to go until its target of recruiting 18,000 of them by mid-May