Biodiversity loss is a major environmental challenge, and limited resources require conservation actions to be strategically prioritized. Buenos Aires Province, Argentina, is one of the most transformed, with over 60% of its territory altered by agriculture and urbanization and only 5% formally protected. This study identifies priority areas for the conservation of terrestrial and freshwater vertebrates in the province. We compiled extent of occurrence maps for all native vertebrate species using IUCN assessments, national red lists, field surveys, and biodiversity databases. Distributions were mapped across the 135 districts that serve as administrative units. To estimate conservation importance, species were weighted by threat status and endemism, and potential ranges were delineated under the precautionary principle. The province hosts 708 vertebrate species: birds (55%), freshwater fish (22%), mammals (11%), reptiles (8%), and amphibians (4%). Ten are strict endemics, and many are threatened. We identified 18 districts with high species richness and 15 with the highest conservation priority, concentrated in the Paran & aacute; Delta, the Atlantic coast, and the Ventania and Tandilia highlands. Our results provide an updated, province-wide assessment to support decision makers in developing conservation strategies. Strengthening connectivity, safeguarding freshwater ecosystems, and fostering science-policy-community strategies will be crucial.
Abstract Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy of proteins in aqueous solution is often limited by water absorption and other optical artifacts. To overcome these limitations, we evaluated the structural features and hydrogen-deuterium exchange (HDX) kinetics of the α -helical protein GCN4 in both hydrated (wet) and vacuum-dried (dry) states. While solvent heavily mask the second-derivative spectra of wet samples, vacuum drying yielded a thin, protein-rich film on the ATR crystal, significantly enhancing the signal-to-noise ratio and resolving the protein features without altering the native structure. Dry-state analysis clearly resolved the Amide I, Amide II, and deuterium-shifted Amide II’ (1450 cm −1 ) bands. Notably, second-derivative analysis of the dry spectra of the HDX samples revealed a bimodal Amide I distribution consisting of a stationary band at 1653 cm −1 from the solvent-inaccessible regions and an isotopically sensitive band shifting from 1648 cm −1 to 1644 cm −1 from solvent-accessible regions. These results demonstrate that vacuum-dried ATR-FTIR spectroscopy effectively eliminates solvent masking, providing the spectral clarity required to resolve discrete α -helical sub-populations after deuteration.
Rationale: Poly(ADP-ribose) polymerase-1 (PARP1) is a central mediator of DNA damage response and is upregulated in glioma, supporting it as a molecular imaging biomarker. However, quantitative PET assessment of PARP1 in infiltrative tumors with a preserved blood-brain barrier remains an unmet need. In this study, we evaluated if [18F]Itareparib, a brain-penetrant, non-trapping, PARP1-selective radioligand with reversible kinetics, could improve brain tumor diagnosis and enable target occupancy studies in neurooncology. Methods: [18F]Itareparib was synthesized and evaluated in an orthotopic rat model of BT142 IDH1-mutant gliomas. Dynamic PET scans were performed with or without the administration of the PARP1-selective inhibitor AZD9574. Standardized uptake value ratios (SUVRs) for tumors were calculated using the contralateral region as reference and compared with distribution volume ratios (DVRs) calculated using kinetic modeling. PARP1-specific binding and tracer stability were assessed using autoradiography, immunofluorescence, biodistribution, and radiometabolite analysis. Brain kinetics of [18F]Itareparib were evaluated in a healthy nonhuman primate (NHP) at baseline and blocking conditions. Results: [18F]Itareparib rapidly entered the rat brains and showed 4-fold higher uptake in BT142 tumors than in the contralateral brain. AZD9574 reduced tumor uptake by 77%, supporting the PARP1-specific binding of [18F]Itareparib in the tumors. SUVR(30-60 min) showed the closest agreement with DVR. Autoradiographic tumor-to-reference mean ratio was 7.3, and AZD9574 reduced the tumor-to-reference ratio by 56%. PARP1 immunofluorescence was higher in tumor than the rest of the brain and correlated with autoradiographic results. In rats, the parent fraction of [18F]Itareparib exceeded 99% in brain through 60 min post tracer injection (p.i.) and was approximately 88% in plasma at 60 min p.i. In the NHP, [18F]Itareparib showed rapid brain uptake, and VT decreased by 21+/-6 % after blocking with AZD9574. Conclusion: [18F]Itareparib showed brain penetration, high in vivo metabolic stability, reversible binding kinetics, and PARP1-specific tumor uptake. These findings support further development of [18F]Itareparib for the quantitative PET imaging of PARP1 in brain tumors. ### Competing Interest Statement The authors have declared no competing interest.
BACKGROUND:Barrett's esophagus (BE) is a pre-cancerous condition with an increased risk of esophageal adenocarcinoma (EAC). Current surveillance involves white light endoscopy with random biopsies (Seattle Protocol, SP) but has limitations. This study explores high-resolution virtual chromoendoscopy (HRMC) as a potential alternative. METHODS:This controlled trial will enroll 110 patients with Barrett's esophagus (BE) across 15 gastroenterology departments in France. Each patient will undergo both HRMC and SP examinations during the same endoscopic procedure. Although the trial is non-randomized, it is important to highlight that the two endoscopists performing either the HRMC or the SP will be blinded to each other's results. Therefore, each patient will serve as their own control. Biopsy decisions will be based on both methods, with any visible lesions resected. The primary objective is to compare the detection rate of HGD and EAC lesions using HRMC with targeted biopsies versus SP with random biopsies. Secondary objectives include comparing detection rates of LGD lesions, procedure time, missed lesions, and cost-effectiveness. DISCUSSION:If HRMC proves superior to SP for detecting HGD and EAC, it could lead to more accurate, efficient, and cost-effective BE surveillance strategies, improving patient outcomes and resource utilization. TRIAL REGISTRATION:ClinicalTrials.gov NCT05229783 - First Submitted 2021-12-07.
