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Emissions reduction and greenhouse gas removal from the atmosphere are both necessary to achieve net-zero emissions and limit climate change1. There is thus a need for improved sorbents for the capture of carbon dioxide from the atmosphere, a process known as direct air capture. In particular, low-cost materials that can be regenerated at low temperatures would overcome the limitations of current technologies. In this work, we introduce a new class of designer sorbent materials known as 'charged-sorbents'. These materials are prepared through a battery-like charging process that accumulates ions in the pores of low-cost activated carbons, with the inserted ions then serving as sites for carbon dioxide adsorption. We use our charging process to accumulate reactive hydroxide ions in the pores of a carbon electrode, and find that the resulting sorbent material can rapidly capture carbon dioxide from ambient air by means of (bi)carbonate formation. Unlike traditional bulk carbonates, charged-sorbent regeneration can be achieved at low temperatures (90-100 °C) and the sorbent's conductive nature permits direct Joule heating regeneration2,3 using renewable electricity. Given their highly tailorable pore environments and low cost, we anticipate that charged-sorbents will find numerous potential applications in chemical separations, catalysis and beyond.
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Dióxido de Carbono , Dióxido de Carbono/análise , Dióxido de Carbono/química , Dióxido de Carbono/isolamento & purificação , Adsorção , Eletrodos , Hidróxidos/química , Atmosfera/química , Carbonatos/química , Ar , Temperatura , Carvão Vegetal/química , Porosidade , Carbono/químicaRESUMO
A few ubiquitin ligases have been shown to target Runx2, the key osteogenic transcription factor and thereby regulate bone formation. The regulation of Runx2 expression and function are controlled both at the transcriptional and posttranslational levels. Really interesting new gene (RING) finger ubiquitin ligases of which RNF138 is a member are important players in the ubiquitin-proteasome system, contributing to the regulation of protein turnover and cellular processes. Here, we demonstrated that RNF138 negatively correlated with Runx2 protein levels in osteopenic ovariectomized rats which implied its role in bone loss. Accordingly, RNF138 overexpression potently inhibited osteoblast differentiation of mesenchyme-like C3H10T1/2 as well primary rat calvarial osteoblast (RCO) cells in vitro, whereas overexpression of catalytically inactive mutant RNF138Δ18-58 (lacks RING finger domain) had mild to no effect. Contrarily, RNF138 depletion copiously enhanced endogenous Runx2 levels and augmented osteogenic differentiation of C3H10T1/2 as well as RCOs. Mechanistically, RNF138 physically associates within multiple regions of Runx2 and ubiquitinates it leading to its reduced protein stability in a proteasome-dependent manner. Moreover, catalytically active RNF138 destabilized Runx2 which resulted in inhibition of its transactivation potential and physiological function of promoting osteoblast differentiation leading to bone loss. These findings underscore the functional involvement of RNF138 in bone formation which is primarily achieved through its modulation of Runx2 by stimulating ubiquitin-mediated proteasomal degradation. Thus, our findings indicate that RNF138 could be a promising novel target for therapeutic intervention in postmenopausal osteoporosis.
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Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core , Osteoblastos , Osteogênese , Ubiquitina-Proteína Ligases , Ubiquitinação , Animais , Feminino , Humanos , Camundongos , Ratos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Células HEK293 , Osteoblastos/metabolismo , Ovariectomia , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica , Ratos Sprague-Dawley , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
Runt-related transcription factor 2 (Runx2) is a key regulator of osteoblast differentiation and bone formation. In Runx2-deficient embryos, skeletal development ceases at the cartilage anlage stage. These embryos die of respiratory failure upon birth and display a complete absence of bone and cartilage mineralization. Here, we identified Hakai, a type of E3 ubiquitin ligase as a potential Runx2 interacting partner through affinity pulldown-based proteomic approach. Subsequently, we observed that similar to Runx2, Hakai was downregulated in osteopenic ovariectomized rats, suggesting its involvement in bone formation. Consistent with this observation, Hakai overexpression significantly enhanced osteoblast differentiation in mesenchyme-like C3H10T1/2 as well as primary rat calvaria osteoblast (RCO) cells in vitro. Conversely, overexpression of a catalytically inactive Hakai mutant (C109A) exhibited minimal to no effect, whereas Hakai depletion markedly reduced endogenous Runx2 levels and impaired osteogenic differentiation in both C3H10T1/2 and RCOs. Mechanistically, Hakai physically interacts with Runx2 and enhances its protein turnover by rescuing it from Smad ubiquitination regulatory factor 2 (Smurf2)-mediated proteasome degradation. Wild-type Hakai but not Hakai-C109A inhibited Smurf2 protein levels through proteasome-mediated degradation. These findings underscore Hakai's functional role in bone formation, primarily through its positive modulation of Runx2 protein turnover by protecting it from Smurf2-mediated ubiquitin-proteasomal degradation. Collectively, our results demonstrate Hakai as a promising novel therapeutic target for osteoporosis.
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Conductive layered metal-organic frameworks (MOFs) have demonstrated promising electrochemical performances as supercapacitor electrode materials. The well-defined chemical structures of these crystalline porous electrodes facilitate structure-performance studies; however, there is a fundamental lack in the molecular-level understanding of charge storage mechanisms in conductive layered MOFs. To address this, we employ solid-state nuclear magnetic resonance (NMR) spectroscopy to study ion adsorption in nickel 2,3,6,7,10,11-hexaiminotriphenylene, Ni3(HITP)2. In this system, we find that separate resonances can be observed for the MOF's in-pore and ex-pore ions. The chemical shift of in-pore electrolyte is found to be dominated by specific chemical interactions with the MOF functional groups, with this result supported by quantum mechanics/molecular mechanics (QM/MM) and density functional theory (DFT) calculations. Quantification of the electrolyte environments by NMR was also found to provide a proxy for electrochemical performance, which could facilitate the rapid screening of synthesized MOF samples. Finally, the charge storage mechanism was explored using a combination of ex-situ NMR and operando electrochemical quartz crystal microbalance (EQCM) experiments. These measurements revealed that cations are the dominant contributors to charge storage in Ni3(HITP)2, with anions contributing only a minor contribution to the charge storage. Overall, this work establishes the methods for studying MOF-electrolyte interactions via NMR spectroscopy. Understanding how these interactions influence the charging storage mechanism will aid the design of MOF-electrolyte combinations to optimize the performance of supercapacitors, as well as other electrochemical devices including electrocatalysts and sensors.
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Tropical ataxic neuropathy (TAN) is characterised by ataxic polyneuropathy, degeneration of the posterior columns and pyramidal tracts, optic atrophy, and sensorineural hearing loss. It has been attributed to nutritional/toxic etiologies, but evidence for the same has been equivocal. TAN shares common clinical features with inherited neuropathies and mitochondrial disorders, it may be hypothesised that genetic abnormalities may underlie the pathophysiology of TAN. This study aimed to establish evidence for mitochondrial dysfunction by adopting an integrated biochemical and multipronged genetic analysis. Patients (n = 65) with chronic progressive ataxic neuropathy with involvement of visual and/or auditory pathways underwent deep phenotyping, genetic studies including mitochondrial DNA (mtDNA) deletion analysis, mtDNA and clinical exome sequencing (CES), and respiratory chain complex (RCC) assay. The phenotypic characteristics included dysfunction of visual (n = 14), auditory (n = 12) and visual + auditory pathways (n = 29). Reduced RCC activity was present in 13 patients. Mitochondrial DNA deletions were noted in five patients. Sequencing of mtDNA (n = 45) identified a homoplasmic variant (MT-ND6) and a heteroplasmic variant (MT-COI) in one patient each. CES (n = 45) revealed 55 variants in nuclear genes that are associated with neuropathy (n = 27), deafness (n = 7), ataxia (n = 4), and mitochondrial phenotypes (n = 5) in 36 patients. This study provides preliminary evidence that TAN is associated with a spectrum of genetic abnormalities, including those associated with mitochondrial dysfunction, which is in contradistinction from the prevailing hypothesis that TAN is related to dietary toxins. Analysing the functional relevance of these genetic variants may improve the understanding of the pathogenesis of TAN.
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Ataxia , DNA Mitocondrial , Humanos , Masculino , Feminino , DNA Mitocondrial/genética , Adulto , Pessoa de Meia-Idade , Ataxia/genética , Adolescente , Doenças Mitocondriais/genética , Adulto Jovem , Mitocôndrias/genética , Criança , Idoso , Sequenciamento do Exoma , FenótipoRESUMO
Vascular dysfunction contributes to the development of osteopenia in hypertensive patients, as decreased blood supply to bones results in tissue damage and dysfunction. The effect of anti-hypertensive medicines on bone mass in hypertensive individuals is inconclusive because of the varied mechanism of their action, and suggests that reducing blood pressure (BP) alone is insufficient to enhance bone mass in hypertension. Pentoxifylline (PTX), a hemorheological drug, improves blood flow by reducing blood viscosity and angiogenesis, also has an osteogenic effect. We hypothesized that improving vascular function is critical to increasing bone mass in hypertension. To test this, we screened various anti-hypertensive drugs for their in vitro osteogenic effect, from which timolol and hydralazine were selected. In adult female spontaneously hypertensive rats (SHRs), timolol and hydralazine did not improve vascular function and bone mass, but PTX improved both. In female SHR animals, PTX restored bone mass, strength and mineralization, up to the level of normotensive control rats. In addition, we observed lower blood vasculature in the femur of adult SHR animals, and PTX restored them. PTX also restored the bone vascular and angiogenesis parameters that had been impaired in OVX SHR compared to sham SHR. This study demonstrates the importance of vascular function in addition to increased bone mass for improving bone health as achieved by PTX without affecting BP, and suggests a promising treatment option for osteoporosis in hypertensive patients, particularly at-risk postmenopausal women.
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Hipertensão , Pentoxifilina , Humanos , Ratos , Feminino , Animais , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Densidade Óssea , Timolol/farmacologia , Timolol/uso terapêutico , Hipertensão/tratamento farmacológico , Ratos Endogâmicos SHR , Pentoxifilina/farmacologia , Hidralazina/farmacologia , Hidralazina/uso terapêutico , Pressão SanguíneaRESUMO
The current study was aimed for the generation of Pleurotus extracellular extract-mediated selenium and zinc-oxide nanoparticles (NPs). The Pleurotus djamor (PD) and Pleurotus sajor-caju (PSC) extracts were incubated with different concentrations of sodium selenate and zinc acetate to yield BioSeNPs and BioZnONPs. The NPs formation led to visual color change (brick-red and white for Se and Zn nanosols, respectively). The synthesized NPs were spherical with size of 124 and 68 nm and 84 and 91 nm for PD and PSC BioSeNPs and BioZnONPs respectively. The UV absorbance peaks were recorded at 293.2 and 292.2 nm and 365.9 and 325.5 nm for BioSeNPs and BioZnONPs derived from PD and PSC respectively. FT-IR spectroscopy indicated specific functional group adoration on metal-based NPs. On supplementation in straw, these NPs improved the fruit body yield besides enhancing their protein and Se/ Zn contents. These biofortified mushrooms could be potential dietary supplement/ nutraceutical.
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Essential oils are highly complex volatile chemical compounds utilized for food preservation. The present study compares the antibacterial, and antibiofilm activities of essential oils (EOs) and their blends. Three EOs-basil, clove, and lemongrass-and their blends were evaluated against five food-borne bacterial pathogens. A concentration-dependent effect with maximum inhibition at minimum inhibitory concentration values was recorded while no synergistic activity was observed on blending of EOs. The mechanism of antibacterial action was identified as ROS burst, leakage of cytoplasmic content, and DNA degradation through fluorescence microscopy, electrical conductivity, and DNA cleavage studies. The role of EOs on biofilm growth was deciphered with lemongrass EO being most effective as it curbed biofilm formation on the surface of corn-starch packaging films. This work highlights the antibacterial action mechanism of EOs and their potential role in curtailing biofilm growth on food-grade packaging material.
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Iron, an essential trace element exhibits detrimental effects on human health when present at higher or lower concentration than the required. Therefore, there is a pressing demand for sensitive and selective detection of Fe3+ in water, food etc. Unfortunately, in several instances, the traditional approaches suffer from a number of shortcomings like complicated procedures, limited sensitivity, poor selectivity and more expensive and time consuming. The scope of optical tuning and excellent photophysical properties of carbon- based nanomaterials like carbon dots (C-dots) and graphene dots (g-dots) have made them promising optical sensors of metal ions. Moreover, high surface area, superior stability of such materials contributes towards the fruitful development of sensors. The present review offered critical information on the fabrication and fluorimetric applications of these functional nanomaterials for sensitive and selective detection of Fe3+. An in-depth discussion on fluorescent C-dots made from naturally occurring materials and chemical techniques were presented. Effect of doping in C-dots was also highlighted in terms of improved fluorescence response and selectivity. In a similar approach g-dots were also discussed. Many of these sensors exhibited great selectivity, superior sensitivity, high quantum yield, robust chemical and photochemical stability and real-time applicability. Further improvement in these factors can be targeted to develop new sensors.
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Macrofungi commonly referred to as Mushrooms are distributed worldwide and well known for their nutritional, medicinal, and organoleptic properties. Strain improvement in mushrooms is lagging due to paucity of efficient genome modification techniques. Thus, for advanced developments in research and commercial or economical viability and benefit, CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9) emerged as an efficient genome editing tool. The higher efficiency and precision of the desired genetic modification(s) are the most valuable attributes of this recent technology. The present review comprehensively summarizes various conventional methods utilized for strain improvement in mushrooms including hybridization, protoplast fusion, and di-mon mating. Furthermore, the problems associated with these techniques have been discussed besides providing the potential recluses. The significance of CRISPR/Cas9 strategies employed for improvement in various mushroom genera has been deliberated, as these strategies will paves the way forward for obtaining improved strain and effective cultivation methods for enhancing the yield and quality of the fruit bodies.
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Agaricales , Sistemas CRISPR-Cas , Edição de Genes , Genoma Fúngico , Edição de Genes/métodos , Sistemas CRISPR-Cas/genética , Agaricales/genéticaRESUMO
BACKGROUND: Neuropsychological Rehabilitation (NR) helps manage cognitive deficits in epilepsy. As internationally developed programs have limited applicability to resource-limited countries, we developed a program to bridge this gap. This 6-week caregiver-assisted, culturally suitable program has components of (1) psychoeducation, (2) compensatory training, and, (3) cognitive retraining and is called EMPOWER (Indigenized Home Based Attention and Memory Rehabilitation Program for Adult Patients with Drug Refractory Epilepsy). Its efficacy needs to be determined. METHODS: We carried out an open-label parallel randomized controlled trial. Adults aged 18-45 years with Drug Refractory Epilepsy (DRE), fluency in Hindi and or English, with impaired attention or memory (n = 28) were randomized to Intervention Group (IG) and Control Group (CG). The primary outcomes were objective memory (Auditory Verbal Learning Test), patient and caregiver reported everyday memory difficulties (Everyday Memory Questionnaire-Revised), number of memory aids in use, depression (Hamilton Depression Rating Scale), anxiety (Hamilton Anxiety Rating Scale) and quality of life (Quality of Life in Epilepsy-31). Intention to treat was carried out for group analysis. In the absence of norms necessary for computing Reliable Change Indices (RCIs), a cut-off of +1.0 Standard Deviation (SD) was utilized to identify clinically meaningful changes in the individual analysis of objective memory. A cut-off of 11.8 points was used for quality of life. Feedback and program evaluation responses were noted. RESULTS: The majority of the sample comprised DRE patients with temporal lobe epilepsy who had undergone epilepsy surgery. Group analysis indicated improved learning (p = 0.013), immediate recall (p = 0.001), delayed recall (p < 0.001), long-term retention (p = 0.031), patient-reported everyday memory (p < 0.001), caregiver-reported everyday memory (p < 0.001), anxiety (p = 0.039) and total quality of life (p < 0.001). Individual analysis showed improvement in 50 %, 64 %, 71 %, 57 %, and 64 % of patients on learning, immediate recall, delayed recall, long-term retention, and total quality of life respectively. Despite improvements, themes indicative of a lack of awareness and understanding of cognitive deficits were identified. Overall, the program was rated favorably by patients and caregivers alike. CONCLUSION: NR shows promise for patients with DRE, however larger studies are warranted. The role of cognition in epilepsy needs to be introduced at the time of diagnosis to help lay the foundation for education and acceptance.
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Epilepsia Resistente a Medicamentos , Epilepsia , Adulto , Humanos , Qualidade de Vida/psicologia , Testes Neuropsicológicos , Epilepsia/psicologia , Memória de Curto PrazoRESUMO
Introduction: Efficient care by labour monitoring tools manages labour, identifies the abnormalities and avoids the fatalities. Various studies are being undertaken by the researchers to understand the limited use of these therapeutic tools. The present study aimed to develop a novel labour monitoring instrument after understanding the barriers and enablers of the currently used tools and using it in the health setting for improving clinical outcomes. Materials and Methods: Methodological research design was adopted to develop the novel tool. Item pool was generated by literature review, focus group discussions and retrospective observations of the partographs. Developed tool was evaluated by various experts by undergoing three rounds and was found to be reliable in terms of stability and equivalency. After undergoing pilot runs by researcher and nurses, tool was found to be feasible and understandable. The developed novel labour monitoring tool was used on 200 intranatal women. Results: Focus group discussions revealed various barriers in the current labour tools, such as lack of clarity, complexity, staff shortage, workload etc. Retrospective observation of filled partographs revealed the incomplete recording of the components of the partograph. The prepared first draft underwent rigorous review by the experts. The prepared novel tool, after being used on 200 intranatal women resulted in 90% of normal vaginal deliveries. Duration of 1st stage of labour was around 5 hours. Conclusion: A novel labour monitoring tool was developed after methodological approach resulting in adequate monitoring and improved labour outcomes.
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BACKGROUND: Pleurotus has a remarkable nutritional and nutraceutical profile due to mineral mobilization and accumulation abilities from the substrate. The present study aimed to observe the effect of single and dual supplementations Se and Zn on biochemical parameters of P. florida, P. sajor caju and P. djamor. Also, the bioaccumulation of the trace elements in fortified mushrooms was estimated. METHODS: Biomass production and radial growth rate were observed on Se and Zn supplemented broth and agar based medium. Furthermore, the influence of Se and Zn supplementation was recorded on the fruit body yield. The colorimetric assays were employed to estimate total soluble protein, total phenol and total flavonoid contents. The antioxidant activity was assayed as DPPH radical scavenging test. While, ICP-AES was performed to estimate the variation in the Zn and Se content of the fruit bodies. RESULTS: The Se supplementation at low rate resulted in improvement in the radial growth rate and biomass production for P. sajor caju. For solid-state fermentation, a better yield was obtained with inorganic salt supplementation in comparison to organically enriched Se straw. The maximum total soluble protein content and total flavonoid content were observed in fruit bodies of P. sajor caju at 4 mg L -1 of Se and Se-Zn respectively. Pleurotus djamor exhibited the highest total phenolic content on Zn supplementation (10 mg L-1). Improved antioxidant potential was recorded with dual supplementations. Salt supplementations caused shrinkage, distortion of the fungal hyphae, and decreased basidiospores with significant amelioration in elemental composition in fortified mushrooms. CONCLUSION: The inorganic salt supplementation increased the biochemical potential of Pleurotus spp. in comparison to organically enriched substrate which could further be used for the development of dietary supplements.
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Pleurotus , Selênio , Selênio/farmacologia , Selênio/metabolismo , Pleurotus/química , Pleurotus/metabolismo , Zinco/metabolismo , Fermentação , Biofortificação , Antioxidantes/metabolismo , Flavonoides/metabolismoRESUMO
We present a temporary keyword search over sensitive and confidential health data in a cloud environment. The cloud constitutes a semi-trusted domain, making it necessary for data owners to secure their data before outsourcing it through techniques like encryption. Attribute-based keyword search techniques tend to perform a search operation using a search token generated by an authorized user. These search tokens can lead to serious privacy threats, as they can extract all ciphertexts that may have been generated along with their keyword. Therefore, restricting search tokens to extract ciphertexts generated within a time interval is a more promising solution. In this paper, we present a novel ciphertext policy fine-grained temporary keyword that prevents the misuse of these search tokens. Further, it mitigates the risk of insider threats within healthcare organizations by limiting the window of opportunity for unauthorized access to minimum. To assess the security, our proposed scheme is formally proven to be secure against Selectively Chosen Keyword Attacks in the generic bilinear group model. Additionally, we demonstrate that the encryption algorithm's complexity is linear in relation to the number of attributes. Our scheme's significance and practicality are revealed by the performance evaluation.
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We outline the presentation of a 68-year-old woman who received a chest radiograph due to her insurance requirements, resulting in the discovery of a left-sided pleural effusion. The effusion was further characterized as loculated on subsequent imaging. Thoracentesis yielded exudative fluid, leading to the patient undergoing video-assisted thoracoscopic surgery (VATS). During this procedure, a cystic mass was visualized, with the conversion of the operation to an open thoracotomy and left lower lobe lobectomy. Pathology was positive for spindle cell sarcoma. A thorough history of the patient revealed a decades-long occupational exposure to asbestos. The significance of this report is to illustrate the clinical presentation, immunohistochemical characteristics, and management of a rare spindle cell malignancy. Our case also raises the importance of screening patients on an individualized, shared decision-making basis.
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Membranous nephropathy (MN) is an autoimmune condition that is a common cause of nephrotic syndrome in nondiabetic adults. In this study, we highlight a case of a 22-year-old male with a past medical history of arthrogryposis multiplex congenita (AMC) who initially presented with right flank pain and hematuria. Subsequent workup revealed significant proteinuria with biopsy-proven primary MN. Early detection of the disease is critical to establish treatment promptly and prevent complications such as those resulting from a hypercoagulable state.
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BACKGROUND Coagulopathies can manifest on a spectrum, from minor mucosal bleeding to life-threatening hemorrhage. Minor cases can be discovered in the setting of known risk factors, such as malignancy, old age, immunosuppression. However, acquired hemophilia A diagnosed after a snake bite is of lesser-known incidence and can present in a more acute, potentially life- or limb-threatening fashion. To properly diagnose this coagulopathy, one must be familiar with the related signs, symptoms, and laboratory findings so that swift diagnosis can follow. Diagnosis is key for early proper management, as displayed in the following case. CASE REPORT Our case report details a male patient presenting with diffuse bruising after a snake bite. Initially, on presentation to outside facilities, the diagnosis of acquired hemophilia A was not found. However, upon worsening of bruising in the setting of previous treatments initiated for the patient, he presented to our facility, where he subsequently received a diagnosis with acquired hemophilia A. He developed compartment syndrome due to excessive bleeding, requiring surgical intervention. With proper diagnosis, his bleeding diathesis was corrected with multiple rounds of repletion of factors and immunosuppression. His follow-up laboratory test results and examinations have shown continued resolution of his symptoms. CONCLUSIONS As acquired hemophilia A is less often linked with snake bites, this case highlights the importance of considering this disease process as a differential in patients with bleeding diathesis after a snake bite. The coagulation dysfunction can be severe, and, as such, early identification of this diagnosis leads to more targeted and effective therapy.
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Hemofilia A , Mordeduras de Serpentes , Humanos , Masculino , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/diagnóstico , Hemofilia A/complicações , Hemofilia A/diagnóstico , Pessoa de Meia-Idade , Doença AgudaRESUMO
Ribosome hibernation is a key survival strategy bacteria adopt under environmental stress, where a protein, hibernation promotion factor (HPF), transitorily inactivates the ribosome. Mycobacterium tuberculosis encounters hypoxia (low oxygen) as a major stress in the host macrophages, and upregulates the expression of RafH protein, which is crucial for its survival. The RafH, a dual domain HPF, an orthologue of bacterial long HPF (HPFlong), hibernates ribosome in 70S monosome form, whereas in other bacteria, the HPFlong induces 70S ribosome dimerization and hibernates its ribosome in 100S disome form. Here, we report the cryo- EM structure of M. smegmatis, a close homolog of M. tuberculosis, 70S ribosome in complex with the RafH factor at an overall 2.8 Å resolution. The N- terminus domain (NTD) of RafH binds to the decoding center, similarly to HPFlong NTD. In contrast, the C- terminus domain (CTD) of RafH, which is larger than the HPFlong CTD, binds to a distinct site at the platform binding center of the ribosomal small subunit. The two domain-connecting linker regions, which remain mostly disordered in earlier reported HPFlong structures, interact mainly with the anti-Shine Dalgarno sequence of the 16S rRNA.
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Mycobacterium tuberculosis , Proteínas Ribossômicas , Proteínas Ribossômicas/metabolismo , Proteínas de Bactérias/química , RNA Ribossômico 16S/metabolismo , Ribossomos/metabolismo , Mycobacterium tuberculosis/metabolismoRESUMO
Chitinases and ecdysteroid hormones are vital for insect development. Crosstalk between chitin and ecdysteroid metabolism regulation is enigmatic. Here, we examined chitinase inhibition effect on Spodoptera frugiperda ecdysteroid metabolism. In vitro studies suggested that berberine inhibits S. frugiperda chitinase 5 (SfCht5). The Berberine feeding resulted in defective S. frugiperda development. Berberine-fed insects showed higher SfCht5 and Chitinase 7 expression and cumulative chitinase activity. Chitinase inhibition led to overexpression of chitinases, ecdysteroid biosynthesis, and responsive genes. SfCht5 silencing and overexpression resulted in ecdysone receptor deregulation. Transcription factors, like Broad Complex Z4, regulate the ecdysteroid metabolism and showed high expression upon berberine ingestion. Broad Complex Z4 binding in 5' UTR of Ecdysone receptor, SfCht5, Chitinase 7, Phantom, Neverland, and other ecdysteroid biosynthesis genes might lead to their upregulation in berberine-fed insects. As a result, berberine-fed insects showed ecdysone overaccumulation. These findings underscore chitinase activity's impact on ecdysone biosynthesis and its transcriptional crosstalk.
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Protein tyrosine phosphatase 1B (PTP1B) plays important roles in cellular homeostasis and is a highly validated therapeutic target for multiple human ailments, including diabetes, obesity and breast cancer. However, much remains to be learned about how conformational changes may convey information through the structure of PTP1B to enable allosteric regulation by ligands or functional responses to mutations. High-resolution X-ray crystallography can offer unique windows into protein conformational ensembles, but comparison of even high-resolution structures is often complicated by differences between data sets, including non-isomorphism. Here, the highest resolution crystal structure of apo wild-type (WT) PTP1B to date is presented out of a total of â¼350 PTP1B structures in the PDB. This structure is in a crystal form that is rare for PTP1B, with two unique copies of the protein that exhibit distinct patterns of conformational heterogeneity, allowing a controlled comparison of local disorder across the two chains within the same asymmetric unit. The conformational differences between these chains are interrogated in the apo structure and between several recently reported high-resolution ligand-bound structures. Electron-density maps in a high-resolution structure of a recently reported activating double mutant are also examined, and unmodeled alternate conformations in the mutant structure are discovered that coincide with regions of enhanced conformational heterogeneity in the new WT structure. These results validate the notion that these mutations operate by enhancing local dynamics, and suggest a latent susceptibility to such changes in the WT enzyme. Together, these new data and analysis provide a detailed view of the conformational ensemble of PTP1B and highlight the utility of high-resolution crystallography for elucidating conformational heterogeneity with potential relevance for function.