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Background: Prion protein gene (PRNP) is widely expressed in a variety of tissues. Although the roles of PRNP in several cancers have been investigated, no pan-cancer analysis has revealed its relationship with tumorigenesis and immunity. Methods: Comprehensive analyses were conducted on The Cancer Genome Atlas (TCGA) Pan-Cancer dataset from the University of California Santa Cruz (UCSC) database to determine the expression of PRNP and its potential prognostic implications. Immune infiltration and enrichment analysis methods were used to ascertain correlations between PRNP expression levels, tumor immunity, and immunotherapy. Additionally, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods were employed to examine possible signaling pathways involving PRNP. In vitro experiments using CCK-8 assay, Wound healing assay, and Transwell assay to detect the effect of Cellular prion protein (PrPC) on proliferation, migration, and invasion in colorectal cancer (CRC) cells. The expression levels of epithelial-mesenchymal transition (EMT)-related proteins (N-cadherin, E-cadherin, Vimentin and Snail) were detected by western blot. Results: Among most cancer types, PRNP is expressed at high levels, which is linked to the prognosis of patients. PRNP expression is strongly associated with immune infiltrating cells, immunosuppressive cell infiltration and immune checkpoint molecules. In addition to tumor mutation burden (TMB), substantial correlations are detected between PRNP expression and microsatellite instability (MSI) in several cancers. In vitro cell studies inferred that PrPC enhanced the proliferation, migration, invasion, and EMT of CRC cells. Conclusion: PRNP serves as an immune-related prognostic marker that holds promise for predicting outcomes related to CRC immunotherapy while simultaneously promoting cell proliferation, migration, and invasion activities. Furthermore, it potentially plays a role in governing EMT regulation within CRC.
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BACKGROUND: The combination of immunotherapy and antiangiogenic therapy has shown potential in the treatment of numerous malignant tumors, but limited evidence was available for soft tissue sarcomas (STS). Therefore, the aim of the present study is to assess the efficacy and safety of immunotherapy in conjunction with antiangiogenic therapy in patients diagnosed with advanced STS (aSTS). METHODS: The study enrolled patients with aSTS from January 2014 to October 2022. Eligible participants had previously received anthracycline-based chemotherapy, presented with an anthracycline-resistant sarcoma subtype, or were ineligible for anthracycline treatment due to medical conditions. Following enrollment, these patients received a combination of immunotherapy and antiangiogenic therapy. The primary endpoints were the objective response rate (ORR) and progression-free survival (PFS), while the secondary endpoints included the disease control rate (DCR), overall survival (OS), and the incidence of adverse events. RESULTS: Fifty-one patients were included in this cohort study. The median duration of follow-up was 15.8 months. The ORR and DCR were 17.6%, and 76.5%, respectively. The median PFS (mPFS) was 5.8 months (95% CI: 4.8-6.8) for all patients, and the median OS had not been reached as of the date cutoff. Multivariate analysis indicated that Eastern Cooperative Oncology Group performance status of 0-1 and ≤ second-line treatment were positive predictors for both PFS and OS. Patients with alveolar soft part sarcoma or clear cell sarcoma had longer mPFS (16.2 months, 95% CI: 7.8-25.6) when compared to those with other subtypes of STS (4.4 months, 95% CI: 1.4-7.5, P < 0.001). Among the observed adverse events, hypertension (23.5%), diarrhea (17.6%), and proteinuria (17.6%) were the most common, with no treatment-related deaths reported. CONCLUSION: The combination of immunotherapy and antiangiogenic agents showed promising efficacy and acceptable toxicity in patients with aSTS, especially those with alveolar soft part sarcoma or clear cell sarcoma.
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Inibidores da Angiogênese , Imunoterapia , Sarcoma , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/administração & dosagem , Adulto , Sarcoma/tratamento farmacológico , Sarcoma/terapia , Sarcoma/mortalidade , Sarcoma/patologia , Idoso , Imunoterapia/métodos , Imunoterapia/efeitos adversos , Resultado do Tratamento , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Intervalo Livre de Progressão , Adulto Jovem , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/efeitos adversosRESUMO
Facial action units (AUs) focus on a comprehensive set of atomic facial muscle movements for human expression understanding. Based on supervised learning, discriminative AU representation can be achieved from local patches where the AUs are located. Unfortunately, accurate AU localization and characterization are challenged by the tremendous manual annotations, which limits the performance of AU recognition in realistic scenarios. In this study, we propose an end-to-end self-supervised AU representation learning model (SsupAU) to learn AU representations from unlabeled facial videos. Specifically, the input face is decomposed into six components using autoencoders: five photo-geometric meaningful components, together with 2D flow field AUs. By constructing the canonical neutral face, posed neutral face, and posed expressional face gradually, these components can be disentangled without supervision, therefore the AU representations can be learned. To construct the canonical neutral face without manually labeled ground truth of emotion state or AU intensity, two priori knowledge based assumptions are proposed: 1) identity consistency, which explores the identical albedos and depths of different frames in a face video, and helps to learn the camera color mode as an extra cue for canonical neutral face recovery. 2) average face, which enables the model to discover a 'neutral facial expression' of the canonical neutral face and decouple the AUs in representation learning. To the best of our knowledge, this is the first attempt to design self-supervised AU representation learnging method based on the definition of AUs. Substantial experiments on benchmark datasets have demonstrated the superior performance of the proposed work in comparison to other state-of-the-art approaches, as well as an outstanding capability of decomposing input face into meaningful factors for its reconstruction. The code is made available at https://github.com/Sunner4nwpu/SsupAU.
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Introduction: The unique dormancy of Mycobacterium tuberculosis plays a significant role in the major clinical treatment challenge of tuberculosis, such as its long treatment cycle, antibiotic resistance, immune escape, and high latent infection rate. Methods: To determine the function of MtrA, the only essential response regulator, one strategy was developed to establish its regulatory network according to high-quality genome-wide binding sites. Results and discussion: The complex modulation mechanisms were implied by the strong bias distribution of MtrA binding sites in the noncoding regions, and 32.7% of the binding sites were located inside the target genes. The functions of 288 potential MtrA target genes predicted according to 294 confirmed binding sites were highly diverse, and DNA replication and damage repair, lipid metabolism, cell wall component biosynthesis, cell wall assembly, and cell division were the predominant pathways. Among the 53 pathways shared between dormancy/resuscitation and persistence, which accounted for 81.5% and 93.0% of the total number of pathways, respectively, MtrA regulatory genes were identified not only in 73.6% of their mutual pathways, but also in 75.4% of the pathways related to dormancy/resuscitation and persistence respectively. These results suggested the pivotal roles of MtrA in regulating dormancy/resuscitation and the apparent relationship between dormancy/resuscitation and persistence. Furthermore, the finding that 32.6% of the MtrA regulons were essential in vivo and/or in vitro for M. tuberculosis provided new insight into its indispensability. The findings mentioned above indicated that MtrA is a novel promising therapeutic target for tuberculosis treatment since the crucial function of MtrA may be a point of weakness for M. tuberculosis.
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Hematopoietic stem progenitor cells (HSPCs) are derived from a specialized subset of endothelial cells named hemogenic endothelial cells (HECs) via a process of endothelial-to-hematopoietic transition during embryogenesis. Recently, with the usage of multiple single-cell technologies and advanced genetic lineage tracing techniques, namely, "TIF" approaches that combining transcriptome, immunophenotype and function/fate analyses, massive new insights have been achieved regarding the cellular and molecular evolution underlying the emergence of HSPCs from embryonic vascular beds. In this review, we focus on the most recent advances in the enrichment markers, functional characteristics, developmental paths, molecular controls, and the embryonic site-relevance of the key intermediate cell populations bridging embryonic vascular and hematopoietic systems, namely HECs and pre-hematopoietic stem cells, the immediate progenies of some HECs, in mouse and human embryos. Specifically, using expression analyses at both transcriptional and protein levels and especially efficient functional assays, we propose that the onset of Kit expression is at the HEC stage, which has previously been controversial.
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Excited-ground-state transition and strand slippage of RNA play key roles in transcription and translation of central dogma. Due to limitation of current experimental techniques, the dynamic structure ensembles of RNA remain inadequately understood. Molecular dynamics simulations offer a promising complementary approach, whose accuracy depends on the force field. Here, we develop the new version of RNA base-specific force field (BSFF2) to address underestimation of base pairing stability and artificial backbone conformations. Extensive evaluations on typical RNA systems have comprehensively confirmed the accuracy of BSFF2. Furthermore, BSFF2 demonstrates exceptional efficiency in de novo folding of tetraloops and reproducing base pair reshuffling transition between RNA excited and ground states. Then, we explored the RNA strand slippage mechanism with BSFF2. We conducted a comprehensive three-dimensional structural investigation into the strand slippage of the most complex r(G4C2)9 repeat element and presented the molecular details in the dynamic transition along with the underlying mechanism. Our results of capturing the strand slippage, excited-ground transition, de novo folding, and simulations for various typical RNA motifs indicate that BSFF2 should be one of valuable tools for dynamic conformation research and structure prediction of RNA, and a future contribution to RNA-targeted drug design as well as RNA therapy development.
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Pareamento de Bases , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico , RNA , RNA/químicaRESUMO
Host specificity plays important roles in expanding the host range of rhizobia, while the genetic information responsible for host specificity remains largely unexplored. In this report, the roots of four symbiotic systems with notable different symbiotic phenotypes and the control were studied at four different post-inoculation time points by RNA sequencning (RNA-seq). The differentially expressed genes (DEGs) were divided into "found only in soybean or Lotus," "only expressed in soybean or Lotus," and "expressed in both hosts" according to the comparative genomic analysis. The distributions of enriched function ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways vary significantly in different symbiotic systems. Host specific genes account for the majority of the DEGs involved in response to stimulus, associated with plant-pathogen interaction pathways, and encoding resistance (R) proteins, the symbiotic nitrogen fixation (SNF) proteins and the target proteins in the SNF-related modules. Our findings provided molecular candidates for better understanding the mechanisms of symbiotic host-specificity.
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In the process of searching for anti-breast cancer agents, five sesquiterpene lactones (1-5), including two previously undescribed ones, yjaponica B-C (1-2), were isolated from the herb of Youngia japonica. Their structures were elucidated by spectroscopic data analyses and Marfey's method. Cytotoxic activities of all compounds against A549, U87, and 4T1â cell lines were tested using the CCK8 assay. The result showed that compound 3 possessed the highest cytotoxic activity against 4T1 cells with an IC50 value of 10.60â µM. Furthermore, compound 3 distinctly induced apoptosis, inhibited immigration, and blocked the cell cycle of 4T1 cells. In addition, compound 3 induced the production of reactive oxygen species. Further anticancer mechanism studies showed that compound 3 significantly upregulated expression of the cleaved caspase 3 and PARP, whereas it downregulated the expression of Bcl-2, cyclin D1, cyclin A2, CDK4, and CDK2. Taken together, our results demonstrate that compound 3 has a high potential of being used as a leading compound for the discovery of new anti-breast cancer agent.
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The potential for secondary stroke prevention, which can significantly reduce the risk of recurrent strokes by almost 90%, underscores its critical importance. N-butylphthalide (NBP) has emerged as a promising treatment for acute cerebral ischemia, yet its efficacy for secondary stroke prevention is hindered by inadequate pharmacokinetic properties. This study, driven by a comprehensive structural analysis, the iterative process of structure optimization culminated in the identification of compound B4, which demonstrated exceptional neuroprotective efficacy and remarkable oral exposure and oral bioavailability. Notably, in an in vivo transient middle cerebral artery occlusion (tMCAO) model, B4 substantially attenuated infarct volumes, surpassing the effectiveness of NBP. While oral treatment with B4 exhibited stronger prevention potency than NBP in photothrombotic (PT) model. In summary, compound B4, with its impressive oral bioavailability and potent neuroprotective effects, offers promise for both acute ischemic stroke treatment and secondary stroke prevention.
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AVC Isquêmico , Fármacos Neuroprotetores , Prevenção Secundária , Sais de Tetrazólio , Animais , Humanos , Masculino , Camundongos , Ratos , Administração Oral , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Descoberta de Drogas , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/prevenção & controle , AVC Isquêmico/prevenção & controle , AVC Isquêmico/tratamento farmacológico , Camundongos Endogâmicos C57BL , Estrutura Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/síntese química , Relação Estrutura-Atividade , Sais de Tetrazólio/administração & dosagem , Sais de Tetrazólio/farmacocinética , Sais de Tetrazólio/farmacologia , Ratos Sprague-Dawley , FemininoRESUMO
Applications of zinc-air batteries are partially limited by the slow kinetics of oxygen reduction reaction (ORR); Thus, developing effective strategies to address the compatibility issue between performance and stability is crucial, yet it remains a significant challenge. Here, we propose an in situ gas etching-thermal assembly strategy with an in situ-grown graphene-like shell that will favor Mn anchoring. Gas etching allows for the simultaneous creation of mesopore-dominated carbon cores and ultrathin carbon layer shells adorned entirely with highly dispersed Mn-N4 single-atom sites. This approach effectively resolves the compatibility issue between activity and stability in a single step. The unique core-shell structure allows for the full exposure of active sites and effectively prevents the agglomerations and dissolution of Mn-N4 sites in cores. The corresponding half-wave potential for ORR is up to 0.875 V (vs. reversible hydrogen electrode (RHE)) in 0.1 M KOH. The gained catalyst (Mn-N@Gra-L)-assembled zinc-air battery has a high peak power density (242 mW cm-2) and a durability of â¼ 115 h. Furthermore, replacing the zinc anode achieved a stable cyclic discharge platform of â¼ 20 h at varying current densities. Forming more fully exposed and stable existing Mn-N4 sites is a governing factor for improving the electrocatalytic ORR activity, significantly cycling durability, and reversibility of zinc-air batteries.
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The development of minimally invasive surgery has greatly advanced precision tumor surgery, but sometime suffers from restricted visualization of the surgical field, especially during the removal of abdominal tumors. A 3-D inspection of tumors could be achieved by intravenously injecting tumor-selective fluorescent probes, whereas most of which are unable to instantly distinguish tumors via in situ spraying, which is urgently needed in the process of surgery in a convenient manner. In this study, this work has designed an injectable and sprayable fluorescent nanoprobe, termed Poly-g-BAT, to realize rapid tumor imaging in freshly dissected human colorectal tumors and animal models. Mechanistically, the incorporation of γ-glutamyl group facilitates the rapid internalization of Poly-g-BAT, and these internalized nanoprobes can be subsequently activated by intracellular NAD(P)H: quinone oxidoreductase-1 to release near-infrared fluorophores. As a result, Poly-g-BAT can achieve a superior tumor-to-normal ratio (TNR) up to 12.3 and enable a fast visualization (3 min after in situ spraying) of tumor boundaries in the xenograft tumor models, Apcmin/+ mice models and fresh human tumor tissues. In addition, Poly-g-BAT is capable of identifying minimal premalignant lesions via intravenous injection.
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Background: Only two Otacilia Thorell, 1897 species with troglobitic characteristics have been recorded from Laos and no records of troglobitic Otacilia species from China. New information: A new troglobitic species is reported from Guangxi, China: Otaciliakhezu Lin & Li, sp. nov. (ââ). Photos and morphological descriptions of the new species are presented; the type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS), Beijing.
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Recent studies have shifted the spotlight from adult disease to gametogenesis and embryo developmental events, and these are greatly affected by various environmental chemicals, such as drugs, metabolites, pollutants, and others. Growing research has highlighted the critical importance of identifying and understanding the roles of chemicals in reproductive biology. However, the functions and mechanisms of chemicals in reproductive processes remain incomplete. We developed a comprehensive database called the Reproductive Chemical Database (RCDB) ( https://yu.life.sjtu.edu.cn/ChenLab/RCDB ) to facilitate research on chemicals in reproductive biology. This resource is founded on rigorous manual literature extraction and precise protein target prediction methodologies. This database focuses on the delineation of chemicals associated with phenotypes, diseases, or endpoints intricately associated with four important reproductive processes: female and male gamete generation, fertilization, and embryo development in human and mouse. The RCDB encompasses 93 sub-GO processes, and it revealed 1447 intricate chemical-biological process interactions. To date, the RCDB has meticulously cataloged and annotated 830 distinct chemicals, while also predicting 614 target proteins from a selection of 3800 potential candidates. Additionally, the RCDB offers an online predictive tool that empowers researchers to ascertain whether specific chemicals play discernible functional roles in these reproductive processes. The RCDB is an exhaustive, cross-platform, manually curated database, which provides a user-friendly interface to search, browse, and use reproductive processes modulators and their comprehensive related information. The RCDB will help researchers to understand the whole reproductive process and related diseases and it has the potential to promote reproduction research in the pharmacological and pathophysiological areas.
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High expression of ubiquitin-specific protease 10 (USP10) promote the proliferation of hepatocellular carcinoma (HCC), thus the development of USP10 inhibitors holds promise as a novel therapeutic approach for HCC treatment. However, the development of selective USP10 inhibitor is still limited. In this study, we developed a novel USP10 inhibitor for investigating the feasibility of targeting USP10 for the treatment of HCC. Due to high USP10 inhibition potency and prominent selectivity, compound D1 bearing quinolin-4(1H)-one scaffold was identified as a lead compound. Subsequent research revealed that D1 significantly inhibits cell proliferation and clone formation in HCC cells. Mechanistic insights indicated that D1 targets the ubiquitin pathway, facilitating the degradation of YAP (Yes-associated protein), thereby triggering the downregulation of p53 and its downstream protein p21. Ultimately, this cascade leads to S-phase arrest in HCC cells, followed by cell apoptosis. Collectively, our findings highlight D1 as a promising starting point for USP10-positive HCC treatment, underscoring its potential as a vital tool for unraveling the functional intricacies of USP10.
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Proteínas Adaptadoras de Transdução de Sinal , Antineoplásicos , Carcinoma Hepatocelular , Proliferação de Células , Descoberta de Drogas , Neoplasias Hepáticas , Fatores de Transcrição , Ubiquitina Tiolesterase , Proteínas de Sinalização YAP , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Proliferação de Células/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitina Tiolesterase/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Relação Estrutura-Atividade , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas de Sinalização YAP/metabolismo , Estrutura Molecular , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Apoptose/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/síntese química , Linhagem Celular TumoralRESUMO
Wastewater surveillance has emerged as a crucial public health tool for population-level pathogen surveillance. Supported by funding from the American Rescue Plan Act of 2021, the FDA's genomic epidemiology program, GenomeTrakr, was leveraged to sequence SARS-CoV-2 from wastewater sites across the United States. This initiative required the evaluation, optimization, development, and publication of new methods and analytical tools spanning sample collection through variant analyses. Version-controlled protocols for each step of the process were developed and published on protocols.io. A custom data analysis tool and a publicly accessible dashboard were built to facilitate real-time visualization of the collected data, focusing on the relative abundance of SARS-CoV-2 variants and sub-lineages across different samples and sites throughout the project. From September 2021 through June 2023, a total of 3,389 wastewater samples were collected, with 2,517 undergoing sequencing and submission to NCBI under the umbrella BioProject, PRJNA757291. Sequence data were released with explicit quality control (QC) tags on all sequence records, communicating our confidence in the quality of data. Variant analysis revealed wide circulation of Delta in the fall of 2021 and captured the sweep of Omicron and subsequent diversification of this lineage through the end of the sampling period. This project successfully achieved two important goals for the FDA's GenomeTrakr program: first, contributing timely genomic data for the SARS-CoV-2 pandemic response, and second, establishing both capacity and best practices for culture-independent, population-level environmental surveillance for other pathogens of interest to the FDA. IMPORTANCE: This paper serves two primary objectives. First, it summarizes the genomic and contextual data collected during a Covid-19 pandemic response project, which utilized the FDA's laboratory network, traditionally employed for sequencing foodborne pathogens, for sequencing SARS-CoV-2 from wastewater samples. Second, it outlines best practices for gathering and organizing population-level next generation sequencing (NGS) data collected for culture-free, surveillance of pathogens sourced from environmental samples.
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COVID-19 , SARS-CoV-2 , United States Food and Drug Administration , Águas Residuárias , SARS-CoV-2/genética , Estados Unidos/epidemiologia , Águas Residuárias/virologia , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/prevenção & controle , COVID-19/virologia , Humanos , Pandemias/prevenção & controle , Genoma Viral/genética , Vigilância Epidemiológica Baseada em Águas ResiduáriasRESUMO
Protein design is central to nearly all protein engineering problems, as it can enable the creation of proteins with new biological functions, such as improving the catalytic efficiency of enzymes. One key facet of protein design, fixed-backbone protein sequence design, seeks to design new sequences that will conform to a prescribed protein backbone structure. Nonetheless, existing sequence design methods present limitations, such as low sequence diversity and shortcomings in experimental validation of the designed functional proteins. These inadequacies obstruct the goal of functional protein design. To improve these limitations, we initially developed the Graphormer-based Protein Design (GPD) model. This model utilizes the Transformer on a graph-based representation of three-dimensional protein structures and incorporates Gaussian noise and a sequence random masks to node features, thereby enhancing sequence recovery and diversity. The performance of the GPD model was significantly better than that of the state-of-the-art ProteinMPNN model on multiple independent tests, especially for sequence diversity. We employed GPD to design CalB hydrolase and generated nine artificially designed CalB proteins. The results show a 1.7-fold increase in catalytic activity compared to that of the wild-type CalB and strong substrate selectivity on p-nitrophenyl acetate with different carbon chain lengths (C2-C16). Thus, the GPD method could be used for the de novo design of industrial enzymes and protein drugs. The code was released at https://github.com/decodermu/GPD.
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Engenharia de Proteínas , Proteínas , Proteínas/química , Sequência de Aminoácidos , Engenharia de Proteínas/métodosRESUMO
Capillary hemangiomas, usually found in skin and mucosal tissues, are rarely encountered within the spinal cord, presenting a significant diagnostic challenge. We report a rare case of intradural extramedullary capillary hemangioma at the conus medullaris in a 66-year-old female patient. Our initial diagnosis leaned towards a cystic hemangioblastoma based on MRI findings due to the presence of cystic formation with an enhanced mural nodule. However, surgical exploration and subsequent pathological examination revealed the lesion as a capillary hemangioma. To the authors' knowledge, this case may represent the first documented instance of a spinal capillary hemangioma that mimics a cystic hemangioblastoma.
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Disordered proteins are conformationally flexible proteins that are biologically important and have been implicated in devastating diseases such as Alzheimer's disease and cancer. Unlike stably folded structured proteins, disordered proteins sample a range of different conformations that needs to be accounted for. Here, we treat disordered proteins as polymer chains, and compute a dimensionless quantity called instantaneous shape ratio (Rs), as Rs = Ree2/Rg2, where Ree is end-to-end distance and Rg is radius of gyration. Extended protein conformations tend to have high Ree compared with Rg, and thus have high Rs values, whereas compact conformations have smaller Rs values. We use a scatter plot of Rs (representing shape) against Rg (representing size) as a simple map of conformational landscapes. We first examine the conformational landscape of simple polymer models such as Random Walk, Self-Avoiding Walk, and Gaussian Walk (GW), and we notice that all protein/polymer maps lie within the boundaries of the GW map. We thus use the GW map as a reference and, to assess conformational diversity, we compute the fraction of the GW conformations (fC) covered by each protein/polymer. Disordered proteins all have high fC scores, consistent with their disordered nature. Each disordered protein accesses a different region of the reference map, revealing differences in their conformational ensembles. We additionally examine the conformational maps of the nonviral gene delivery vector polyethyleneimine at various protonation states, and find that they resemble disordered proteins, with coverage of the reference map decreasing with increasing protonation state, indicating decreasing conformational diversity. We propose that our method of combining Rs and Rg in a scatter plot generates a simple, meaningful map of the conformational landscape of a disordered protein, which in turn can be used to assess conformational diversity of disordered proteins.
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Proteínas Intrinsicamente Desordenadas , Conformação Proteica , Proteínas Intrinsicamente Desordenadas/química , Modelos Moleculares , Polímeros/químicaRESUMO
PURPOSE: To evaluate changes in retinal microvascular density and choroidal vascularity in patients with retinoblastoma (RB) after intra-arterial chemotherapy (IAC). DESIGN: Retrospective clinical cohort study. METHODS: This study included 12 unilateral RB eyes treated with IAC (RB tumor), 12 contralateral normal eyes (RB fellow), and 12 healthy controls. The macular retinal thickness and retinal microvascular structure, including the foveal avascular zone (FAZ) area, macular and peripapillary superficial vessel density (SVD), and deep vessel density (DVD), were measured by optical coherence tomography angiography (OCTA). The choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI), were measured by spectral-domain optical coherence tomography (SD-OCT). A comparison among the 3 groups was conducted, and the correlations among the parameters were analyzed. RESULTS: Among the 3 cohorts, the foveal retinal thickness, SVD, DVD, ChT, TCA, LA, SA, and CVI were significantly lower in RB tumor compared to RB fellow and the control eyes (all P < .01). There were no significant differences in the parameters between the contralateral and control eyes. The correlation analyses indicated a significant negative correlation between the total melphalan dose and foveal and parafoveal DVD, ChT, and LA. CONCLUSIONS: The retinal microvascular density and choroidal vascularity were lower in unilateral RB treated with IAC, and seemed to be related to the total melphalan dose. There were no measurable changes in the contralateral eyes.