The rockefeller university

We developed a first-of-kind dasatinib-derivative imaging agent, F-18-SKI-249380 (F-18-SKI), and validated its use for noninvasive in vivo tyrosine kinase-targeted tumor detection in preclinical models. In this study, we assessed the feasibility of using F-18-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 after injection of F-18-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 after injection and blood-based radioactivity measurements to determine the time course of tracer distribution and facilitate radiation dose estimates. A subset of 3 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 F-18-SKI. In total, 27 tumor lesions were analyzed, with a median SUVpeak of 1.4 (range, 0.7-2.3) and tumor-to-blood ratios of 1.6 (range, 0.8-2.5) at 90 min after injection. The intratumoral drug concentrations calculated for 4 reference lesions ranged from 0.03 to 0.07 nM. In all reference lesions, constant tracer accumulation was observed between 30 and 90 min after injection. A blood radioassay 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 a plateau (n = 2). Like dasatinib, F-18-SKI underwent extensive metabolism after 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 mSv/MBq (SD, 0.0034 mSv/MBq). Conclusion: F-18-SKI demonstrated significant tumor uptake, distinct image contrast despite low injected doses, and rapid clearance from blood.

Background Population-based data on COVID-19 are essential for guiding policies. There are few such studies, particularly from low or middle-income countries. Brazil is currently a hotspot for COVID-19 globally. We aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence by city and according to sex, age, ethnicity group, and socioeconomic status, and compare seroprevalence estimates with official statistics on deaths and cases. Methods In this repeated cross-sectional study, we did two seroprevalence surveys in 133 sentinel cities in all Brazilian states. We randomly selected households and randomly selected one individual from all household members. We excluded children younger than 1 year. Presence of antibodies against SARS-CoV-2 was assessed using a lateral flow point-of-care test, the WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech, Guangzhou, China), using two drops of blood from finger prick samples. This lateral-flow assay detects IgG and IgM isotypes that are specific to the SARS-CoV-2 receptor binding domain of the spike protein. Participants also answered short questionnaires on sociodemographic information (sex, age, education, ethnicity, household size, and household assets) and compliance with physical distancing measures. Findings We included 25 025 participants in the first survey (May 14-21) and 31165 in the second (June 4-7). For the 83 (62%) cities with sample sizes of more than 200 participants in both surveys, the pooled seroprevalence increased from 1.9% (95% CI 1.7-2.1) to 3.1% (2.8-3.4). City-level prevalence ranged from 0% to 25.4% in both surveys. 11(69%) of 16 cities with prevalence above 2.0% in the first survey were located in a stretch along a 2000 km of the Amazon river in the northern region. In the second survey, we found 34 cities with prevalence above 2.0%, which included the same 11 Amazon cities plus 14 from the northeast region, where prevalence was increasing rapidly. Prevalence levels were lower in the south and centre-west, and intermediate in the southeast, where the highest level was found in Rio de Janeiro (7.5% [4.2-12.2]). In the second survey, prevalence was similar in men and women, but an increased prevalence was observed in participants aged 20-59 years and those living in crowded conditions (4.4% [3.5-5.6] for those living with households with six or more people). Prevalence among Indigenous people was 6.4% (4.1-9.4) compared with 1.4% (1.2-1.7) among White people. Prevalence in the poorest socioeconomic quintile was 3.7% (3- 2-4.3) compared with 1.7% (1.4-2-2) in the wealthiest quintile. Interpretation Antibody prevalence was highly heterogeneous by country region, with rapid initial escalation in Brazil's north and northeast. Prevalence is strongly associated with Indigenous ancestry and low socioeconomic status. These population subgroups are unlikely to be protected if the policy response to the pandemic by the national government continues to downplay scientific evidence. Copyright (C) 2020 The Author(s). Published by Elsevier Ltd.

As sensory information moves through the brain, higher-order areas exhibit more complex tuning than lower areas. Though models predict that complexity arises via convergent inputs from neurons with diverse response properties, in most vertebrate systems, convergence has only been inferred rather than tested directly. Here, we measure sensory computations in zebrafish vestibular neurons across multiple axes in vivo. We establish that whole-cell physiological recordings reveal tuning of individual vestibular afferent inputs and their postsynaptic targets. Strong, sparse synaptic inputs can be distinguished by their amplitudes, permitting analysis of afferent convergence in vivo. An independent approach, serial-section electron microscopy, supports the inferred connectivity. We find that afferents with similar or differing preferred directions converge on central vestibular neurons, conferring more simple or complex tuning, respectively. Together, these results provide a direct, quantifiable demonstration of feedforward input convergence in vivo.

An essential mechanism for severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection begins with the viral spike protein binding to the human receptor protein angiotensinconverting enzyme II (ACE2). Here, we describe a stepwise engineering approach to generate a set of affinity optimized, enzymatically inactivated ACE2 variants that potently block SARSCoV-2 infection of cells. These optimized receptor traps tightly bind the receptor binding domain (RBD) of the viral spike protein and prevent entry into host cells. We first computationally designed the ACE2-RBD interface using a two-stage flexible protein backbone design process that improved affinity for the RBD by up to 12-fold. These designed receptor variants were affinity matured an additional 14-fold by random mutagenesis and selection using yeast surface display. The highest-affinity variant contained seven amino acid changes and bound to the RBD 170-fold more tightly than wild-type ACE2. With the addition of the natural ACE2 collectrin domain and fusion to a human immunoglobulin crystallizable fragment (Fc) domain for increased stabilization and avidity, the most optimal ACE2 receptor traps neutralized SARS-CoV-2-pseudotyped lentivirus and authentic SARS-CoV-2 virus with half-maximal inhibitory concentrations (IC50s) in the 10- to 100-ng/mL range. Engineered ACE2 receptor traps offer a promising route to fighting infections by SARS-CoV-2 and other ACE2-using coronaviruses, with the key advantage that viral resistance would also likely impair viral entry. Moreover, such traps can be predesigned for viruses with known entry receptors for faster therapeutic response without the need for neutralizing antibodies isolated from convalescent patients.

Polo-like kinases (PLKs) play widely conserved roles in orchestrating meiotic chromosome dynamics. However, how PLKs are targeted to distinct subcellular localizations during meiotic progression remains poorly understood. Here, we demonstrate that the cyan-dependent kinase CDK-1 primes the recruitment of PLK-2 to the synaptonemal complex (SC) through phosphorylation of SYP-1 in C. elegans. SYP-1 phosphorylation by CDK-1 occurs just before meiotic onset. However, PLK-2 docking to the SC is prevented by the nucleoplasmic HAL-2/3 complex until crossover designation, which constrains PLK-2 to special chromosomal regions known as pairing centers to ensure proper homologue pairing and synapsis. PLK-2 is targeted to crossover sites primed by CDK-1 and spreads along the SC by reinforcing SYP-1 phosphorylation on one side of each crossover only when threshold levels of crossovers are generated. Thus, the integration of chromosome-autonomous signaling and a nucleus-wide crossover-counting mechanism partitions holocentric chromosomes relative to the crossover site, which ultimately defines the pattern of chromosome segregation during meiosis I.

Severe cellular sensitivity and aberrant chromosomal rearrangements in response to DNA interstrand crosslink (ICL) inducing agents are hallmarks of Fanconi anemia (FA) deficient cells. These phenotypes have previously been ascribed to inappropriate activity of non-homologous end joining (NHEJ) rather than a direct consequence of DNA ICL repair defects. Here we used chemical inhibitors, RNAi, and Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-Cas9 to inactivate various components of NHEJ in cells from FA patients. We show that suppression of DNA-PKcs, DNA Ligase IV, and 53BP1 is not capable of rescuing ICL-induced proliferation defects and only53BP1knockout partially suppresses the chromosomal abnormalities of FA patient cells.

Bladder cancer prognosis is closely linked to the underlying differentiation state of the tumor, ranging from the less aggressive and most-differentiated luminal tumors to the more aggressive and least-differentiated basal tumors. Sequencing of bladder cancer has revealed that loss-of-function mutations in chromatin regulators and mutations that activate receptor tyrosine kinase (RTK) signaling frequently occur in bladder cancer. However, little is known as to whether and how these two types of mutations functionally interact or cooperate to regulate tumor growth and differentiation state. Here, we focus on loss of the histone demethylase UTX (also known as KDM6A) and activation of the RTK FGFR3, two events that commonly cooccur in muscle invasive bladder tumors. We show that UTX loss and FGFR3 activation cooperate to disrupt the balance of luminal and basal gene expression in bladder cells. UTX localized to enhancers surrounding many genes that are important for luminal cell fate, and supported the transcription of these genes in a catalytic-independent manner. In contrast to UTX, FGFR3 activation was associated with lower expression of luminal genes in tumors and FGFR inhibition increased transcription of these same genes in cell culture models. This suggests an antagonistic relationship between UTX and FGFR3. In support of this model, UTX loss-of-function potentiated FGFR3-dependent transcriptional effects and the presence of UTX blocked an FGFR3-mediated increase in the colony formation of bladder cells. Taken together, our study reveals how mutations in UTX and FGFR3 converge to disrupt bladder differentiation programs that could serve as a therapeutic target.

Trigeminal neuralgia (TN) is a common, debilitating neuropathic face pain syndrome often resistant to therapy. The familial clustering of TN cases suggests that genetic factors play a role in disease pathogenesis. However, no unbiased, large-scale genomic study of TN has been performed to date. Analysis of 290 whole exome-sequenced TN probands, including 20 multiplex kindreds and 70 parent-offspring trios, revealed enrichment of rare, damaging variants in GABA receptor-binding genes in cases. Mice engineered with a TN-associated de novo mutation (p.Cys188Trp) in the GABA(A) receptor Cl- channel gamma-1 subunit (GABRG1) exhibited trigeminal mechanical allodynia and face pain behavior. Other TN probands harbored rare damaging variants in Na+ and Ca+ channels, including a significant variant burden in the alpha-1H subunit of the voltage-gated Ca2+ channel Cav3.2 (CACNA1H). These results provide exome-level insight into TN and implicate genetically encoded impairment of GABA signaling and neuronal ion transport in TN pathogenesis.