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BACKGROUND: Data on mixed mould infection with COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated pulmonary mucormycosis (CAPM) are sparse. OBJECTIVES: To ascertain the prevalence of co-existent CAPA in CAPM (mixed mould infection) and whether mixed mould infection is associated with early mortality (≤7 days of diagnosis). METHODS: We retrospectively analysed the data collected from 25 centres across India on COVID-19-associated mucormycosis. We included only CAPM and excluded subjects with disseminated or rhino-orbital mucormycosis. We defined co-existent CAPA if a respiratory specimen showed septate hyphae on smear, histopathology or culture grew Aspergillus spp. We also compare the demography, predisposing factors, severity of COVID-19, and management of CAPM patients with and without CAPA. Using a case-control design, we assess whether mixed mould infection (primary exposure) were associated with early mortality in CAPM. RESULTS: We included 105 patients with CAPM. The prevalence of mixed mould infection was 20% (21/105). Patients with mixed mould infection experienced early mortality (9/21 [42.9%] vs. 15/84 [17.9%]; p = 0.02) and poorer survival at 6 weeks (7/21 [33.3] vs. 46/77 [59.7%]; p = 0.03) than CAPM alone. On imaging, consolidation was more commonly encountered with mixed mould infections than CAPM. Co-existent CAPA (odds ratio [95% confidence interval], 19.1 [2.62-139.1]) was independently associated with early mortality in CAPM after adjusting for hypoxemia during COVID-19 and other factors. CONCLUSION: Coinfection of CAPA and CAPM was not uncommon in our CAPM patients and portends a worse prognosis. Prospective studies from different countries are required to know the impact of mixed mould infection.
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COVID-19 , Coinfecção , Mucormicose , Humanos , COVID-19/complicações , COVID-19/mortalidade , Mucormicose/mortalidade , Mucormicose/epidemiologia , Mucormicose/complicações , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Prevalência , Coinfecção/mortalidade , Coinfecção/epidemiologia , Coinfecção/microbiologia , Índia/epidemiologia , Adulto , Aspergilose Pulmonar/complicações , Aspergilose Pulmonar/mortalidade , Aspergilose Pulmonar/epidemiologia , SARS-CoV-2 , Idoso , Estudos de Casos e Controles , Pneumopatias Fúngicas/mortalidade , Pneumopatias Fúngicas/complicações , Pneumopatias Fúngicas/epidemiologiaRESUMO
Despite decades of research, glycosaminoglycans (GAGs) have not been known to interact with sialyl transferases (STs). Using our in-house combinatorial virtual library screening (CVLS) technology, we studied seven human isoforms, including ST6GAL1, ST6GAL2, ST3GAL1, ST3GAL3, ST3GAL4, ST3GAL5, and ST3GAL6, and predicted that GAGs, especially heparan sulfate (HS), are likely to differentially bind to STs. Exhaustive CVLS and molecular dynamics studies suggested that the common hexasaccharide sequence of HS preferentially recognized ST6GAL1 in a site overlapping the binding site of the donor substrate CMP-Sia. Interestingly, CVLS did not ascribe any special role for the rare 3-O-sulfate modification of HS in ST6GAL1 recognition. The computational predictions were tested using spectrofluorimetric studies, which confirmed preferential recognition of HS over other GAGs. A classic chain length-dependent binding of GAGs to ST6GAL1 was observed with polymeric HS displaying a tight affinity of ~65 nM. Biophysical studies also confirmed a direct competition between CMP-Sia and an HS oligosaccharide and CS polysaccharide for binding to ST6GAL1. Overall, our novel observation that GAGs bind to ST6GAL1 with high affinity and compete with the donor substrate is likely to be important because modulation of sialylation of glycan substrates on cells has considerable physiological/pathological consequences. Our work also brings forth the possibility of developing GAG-based chemical probes of ST6GAL1.
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Glicosaminoglicanos , Transferases , Humanos , Glicosaminoglicanos/química , Transferases/metabolismo , Heparitina Sulfato/metabolismo , Sítios de Ligação , Simulação de Dinâmica MolecularRESUMO
This study was designed to investigate possible interference of Xenobiotics with SUMOylation in eukaryotic cells. To begin with, we docked 71 chemical structures from PubChem with human SUMO1 and UBC9 protein structures using Auto Dock 4.2 and Hex 6.3 and selected five compounds for binding studies in Surface Plasmon Resonance (SPR) with human SUMO1. In SPR studies, only endosulfan showed binding to SUMO1 (Kd1.313 × 10-4 M). Further, we treated HePG2 and differentiated 3T3-L1 cells with endosulfan/bisphenol A/perfluorooctanoic acid (PFOA) to test induction of oxidative stress and SUMO isoform/UBC9 expression. Treatment with these compounds resulted in higher levels of nitric oxide (NO), NOS2A mRNA, and reactive oxygen species (ROS) associated with decreased NADPH levels. Additionally, treatment with these chemicals resulted in elevated mRNA levels of IL-6 and IL-1ß in 3T3-L1 cells. In HePG2 cells, endosulfan treatment resulted in elevated mRNA levels of SUMO1, 3 and UBC9, whereas, treatment with bisphenol A resulted in increased mRNA of SUMO2, 3 and UBC9. Treatment with PFOA resulted in elevated mRNA levels of SUMO2. Apart from influencing the gene expression, endosulfan caused decrease in SUMO1-Sumoylation of few proteins. We propose that one reason for the severe health consequences of exposure to endosulfan/bisphenol could be due to induction of oxidative stress and modulation in SUMO and UBC9 gene expression.
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Adipócitos/efeitos dos fármacos , Compostos Benzidrílicos/toxicidade , Endossulfano/toxicidade , Hepatócitos/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Fenóis/toxicidade , Proteína SUMO-1/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinas/metabolismo , Células 3T3-L1 , Adipócitos/enzimologia , Adipócitos/patologia , Animais , Compostos Benzidrílicos/metabolismo , Endossulfano/metabolismo , Células Hep G2 , Hepatócitos/enzimologia , Hepatócitos/patologia , Humanos , Camundongos , Simulação de Acoplamento Molecular , Mioblastos Esqueléticos/enzimologia , Mioblastos Esqueléticos/patologia , Estresse Oxidativo/efeitos dos fármacos , Fenóis/metabolismo , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Proteína SUMO-1/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Sumoilação , Enzimas de Conjugação de Ubiquitina/genética , Ubiquitinas/genéticaRESUMO
The RNA-dependent RNA polymerase (RdRp) of sesbania mosaic virus (SeMV) was previously shown to interact with the viral protein P10, which led to enhanced polymerase activity. In the present investigation, the equilibrium dissociation constant for the interaction between the two proteins was determined to be 0.09 µM using surface plasmon resonance, and the disordered C-terminal domain of RdRp was shown to be essential for binding to P10. The association with P10 brought about a change in the oligomeric state of RdRp, resulting in reduced aggregation and increased polymerase activity. Interestingly, unlike the wild-type RdRp, C-terminal deletion mutants (C del 43 and C del 72) were found to exist predominantly as monomers and were as active as the RdRp-P10 complex. Thus, either the deletion of the C-terminal disordered domain or its masking by binding to P10 results in the activation of polymerase activity. Further, deletion of the C-terminal 85 residues of RdRp resulted in complete loss of activity. Mutation of a conserved tyrosine (RdRp Y480) within motif E, located between 72 and 85 residues from the C-terminus of RdRp, rendered the protein inactive, demonstrating the importance of motif E in RNA synthesis in vitro.
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Vírus de Plantas/enzimologia , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Virais/química , Proteínas Virais/metabolismo , Motivos de Aminoácidos , Vírus de Plantas/química , Vírus de Plantas/genética , Ligação Proteica , Domínios Proteicos , RNA Viral/genética , RNA Viral/metabolismo , RNA Polimerase Dependente de RNA/genética , Proteínas Virais/genéticaRESUMO
Commercial drivers, including pilots, suffering from untreated sleep-related disorders endanger many lives. This puts them at risk of increased daytime somnolence. Through this brief communication, we urge the authorities to make the sleep study mandatory for these drivers to diagnose underlying sleep disorders like sleep apnea.
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Introduction Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has cast a gloom spell on healthcare worldwide, infecting millions of people. Objective The aim of the present study is to determine the prevalence and review the contributing comorbidities and the precipitating factors leading to the emergence of the fungal infections in COVID-19-affected patients. To assess the utility of different laboratory techniques for confirmation of fungal infections. To assess the strengths and limitations of the diagnostic methods. Methods We have studied 252 clinical samples obtained from 121 COVID-positive patients. Results Among the 121 patients clinically diagnosed with fungal infections, 88 had diabetes and were given steroids for treatment ( p -value = 0.001). Ninety-five patients (78.5%) had a positive laboratory diagnosis (either culture positive, potassium hydroxide [KOH]-positive or positive histopathology report). Fungal culture was positive in 75 (61.9%) patients and histopathology report was positive in 62 (51.2%). Histopathology was positive in 7 (5.8%) patients in whom culture and KOH were negative. Conclusion Aggressive treatment methods, administration of immune suppressants, and antibiotics, with an intention to salvage, have made patients susceptible to the benign fungus, causing it to evade the host immunity, thus leading to invasive infections. Applying different laboratory modalities would not only aid in providing fast and valuable information but also help in understanding the pathology which would assist the clinician in selecting the correct treatment for the patient.
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OBJECTIVES: To compare COVID-19-associated pulmonary mucormycosis (CAPM) with COVID-19-associated rhino-orbital mucormycosis (CAROM), ascertain factors associated with CAPM among patients with COVID-19, and identify factors associated with 12-week mortality in CAPM. METHODS: We performed a retrospective multicentre cohort study. All study participants had COVID-19. We enrolled CAPM, CAROM, and COVID-19 subjects without mucormycosis (controls; age-matched). We collected information on demography, predisposing factors, and details of COVID-19 illness. Univariable analysis was used to compare CAPM and CAROM. We used multivariable logistic regression to evaluate factors associated with CAPM (with hypoxemia during COVID-19 as the primary exposure) and at 12-week mortality. RESULTS: We included 1724 cases (CAPM [n = 122], CAROM [n = 1602]) and 3911 controls. Male sex, renal transplantation, multimorbidity, neutrophil-lymphocyte ratio, intensive care admission, and cumulative glucocorticoid dose for COVID-19 were significantly higher in CAPM than in CAROM. On multivariable analysis, COVID-19-related hypoxemia (aOR, 2.384; 95% CI, 1.209-4.700), male sex, rural residence, diabetes mellitus, serum C-reactive protein, glucocorticoid, and zinc use during COVID-19 were independently associated with CAPM. CAPM reported a higher 12-week mortality than CAROM (56 of the 107 [52.3%] vs. 413 of the 1356 [30.5%]; p = 0.0001). Hypoxemia during COVID-19 (aOR [95% CI], 3.70 [1.34-10.25]) and Aspergillus co-infection (aOR [95% CI], 5.40 [1.23-23.64]) were independently associated with mortality in CAPM, whereas surgery was associated with better survival. DISCUSSION: CAPM is a distinct entity with a higher mortality than CAROM. Hypoxemia during COVID-19 illness is associated with CAPM. COVID-19 hypoxemia and Aspergillus co-infection were associated with higher mortality in CAPM.
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Aspergilose , COVID-19 , Coinfecção , Mucormicose , Humanos , Masculino , Mucormicose/complicações , Mucormicose/epidemiologia , Estudos Retrospectivos , Estudos de Coortes , Glucocorticoides , COVID-19/complicações , COVID-19/terapia , Fatores de Risco , Índia/epidemiologia , Hipóxia/complicaçõesRESUMO
A low molecular weight anti-platelet peptide (6.9 kDa) has been purified from Naja kaouthia venom and was named KT-6.9. MALDI-TOF/TOF mass spectrometry analysis revealed the homology of KT-6.9 peptide sequence with many three finger toxin family members. KT-6.9 inhibited human platelet aggregation process in a dose dependent manner. It has inhibited ADP, thrombin and arachidonic acid induced platelet aggregation process in dose dependent manner, but did not inhibit collagen and ristocetin induced platelet aggregation. Strong inhibition (70%) of the ADP induced platelet aggregation by KT-6.9 suggests competition with ADP for its receptors on platelet surface. Anti-platelet activity of KT-6.9 was found to be 25 times stronger than that of anti-platelet drug clopidogrel. Binding of KT-6.9 to platelet surface was confirmed by surface plasma resonance analysis using BIAcore X100. Binding was also observed by a modified sandwich ELISA method using anti-KT-6.9 antibodies. KT-6.9 is probably the first 3 FTx from Indian monocled cobra venom reported as a platelet aggregation inhibitor.
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Plaquetas/efeitos dos fármacos , Venenos Elapídicos/química , Venenos Elapídicos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Difosfato de Adenosina/farmacologia , Ácido Araquidônico/antagonistas & inibidores , Ácido Araquidônico/farmacologia , Células Cultivadas , Clopidogrel , Venenos Elapídicos/isolamento & purificação , Humanos , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Trombina/antagonistas & inibidores , Trombina/farmacologia , Ticlopidina/análogos & derivados , Ticlopidina/farmacologiaRESUMO
Multifunctional bioactive peptides have a wider role in modulating physiological functions and possess multiple biological activities. Peptides from bovine milk with sequences QKALNEINQF [p10] and TKKTKLTEEEKNRL [p14] from α-S2 casein f (79-88) and α-S2 casein f (148-161) were identified to be having multifunctional biological activities and were synthesized. These synthesized peptides show various biological activities like angiotensin-converting enzyme inhibition, prolyl endopeptidase inhibition, antioxidant, and antimicrobial activities. The mode of antimicrobial mechanism was studied and p10 shows depolarization of cell membrane, whereas p14 was found to display DNA-binding activity. Structural studies envisaged backbone flexibility, for differences in their mode of action. Peptide structure function studies were correlated to understand their multifunctional biological activity.
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Inibidores da Enzima Conversora de Angiotensina , Peptídeos Catiônicos Antimicrobianos/metabolismo , Caseínas/metabolismo , Leite/metabolismo , Serina Endopeptidases/metabolismo , Animais , Antioxidantes , Bacillus cereus/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Helicobacter pylori/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Prolil Oligopeptidases , Estrutura Secundária de Proteína , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Objectives: The aim of the study was to evaluate the magnetic resonance imaging (MRI) features of acute invasive fungal rhinosinusitis (AIFRS) at presentation and on follow-up imaging when patients receive treatment with systemic antifungal therapy and surgical debridement. Material and Methods: This is a retrospective analysis of imaging data from a cohort of patients diagnosed with AIFRS during the second wave of COVID-19 in single tertiary referral hospital in South India between March 2021 and May 2021 (n = 68). Final diagnosis was made using a composite reference standard which included a combination of MRI findings, clinical presentation, nasal endoscopy and intraoperative findings, and laboratory proof of invasive fungal infection. Analysis included 62 patients with "Definite AIFRS" findings on MRI and another six patients with "Possible AIFRS" findings on MRI and laboratory proof of invasive fungal infection. Follow-up imaging was available in 41 patients. Results: The most frequent MRI finding was T2 hypointensity in the sinonasal mucosa (94%) followed by mucosal necrosis/loss of contrast-enhancement (92.6%). Extrasinosal inflammation with or without necrosis in the pre-antral fat, retroantral fat, pterygopalatine fossa, and masticator space was seen in 91.1% of the cases. Extrasinosal spread was identified on MRI even when the computed tomography (CT) showed intact bone with normal extrasinosal density. Orbital involvement (72%) was in the form of contiguous spread from either the ethmoid or maxillary sinuses; the most frequent presentation being orbital cellulitis and necrosis, with some cases showing extension to the orbital apex (41%) and inflammation of the optic nerve (32%). A total of 22 patients showed involvement of the cavernous sinuses out of which 10 had sinus thrombosis and five patients had cavernous internal carotid artery involvement. Intracranial extension was seen both in the form of contiguous spread to the pachymeninges over the frontal and temporal lobes (25%) and intra-axial involvement in the form of cerebritis, abscesses, and infarcts (8.8%). Areas of blooming on SWI were noted within the areas of cerebritis and infarcts. Perineural spread of inflammation was seen along the mandibular nerves across foramen ovale in five patients and from the cisternal segment of trigeminal nerve to the root exit zone in pons in three patients. During follow-up, patients with disease progression showed involvement of the bones of skull base, osteomyelitis of the palate, alveolar process of maxilla, and zygoma. Persistent hyperenhancement in the post-operative bed after surgical debridement and resection was noted even in patients with stable disease. Conclusion: Contrast-enhanced MRI must be performed in all patients with suspected AIFRS as non-contrast MRI fails to demonstrate tissue necrosis and CT fails to demonstrate extrasinosal disease across intact bony walls. Orbital apex, pterygopalatine fossa, and the cavernous sinuses form important pathways for disease spread to the skull base and intracranial compartment. While cerebritis, intracranial abscesses, and infarcts can be seen early in the disease due to the angioinvasive nature, perineural spread and skull base infiltration are seen 3-4 weeks after disease onset. Exaggerated soft-tissue enhancement in the post-operative bed after debridement can be a normal finding and must not be interpreted as disease progression.
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Aims to evaluate quality of life in paediatric SDB due to adenotonsillar hypertrophy and efficacy of treatment modalities (medical and surgical) by using OSA-18 questionnaire. Prospective study, conducted from April 2019 to June 2019, including 42 patients with clinical features suggestive of SDB due to adenotonsillar hypertrophy, in age group of 3-15 years. Nasopharyngoscopy was done to grade adenoid hypertrophy. OSA-18 QOL questionnaire was recorded in all patients and depending upon the severity of impact of QOL and grades of adenoid hypertrophy, patients were categorized into two groups. Group 1 received medical treatment and group 2 underwent adenotonsillectomy. Questionnaire was again recorded after 4 weeks. Pretreatment and post-treatment total mean and individual domain scores were compared. Paired t tests was used to evaluate results. Group 1 included 16 children with mild to moderate impact and received medical management. Pretreatment mean OSA-18 score of 70.31 was improved to 33.5. Group 2 enrolled 26 patients with severe impact, were subjected to adenotonsillectomy. Pretreatment and post-treatment mean score were 95.88 and 24.92 respectively. Both groups showed statistically significant improvement in all individual domains and total mean OSA-18 scores indicating improvement in QOL after treatment and efficacy of medical management for mild-moderate SDB and surgery for severe cases. OSA-18 questionnaire is self-administered and disease specific screening tool for early diagnosis and evaluation of QOL before and after treatment. It also helps to categorize patients for advocating appropriate treatment and to evaluate efficacy of treatment modalities.
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This study reports a novel bio-layer interferometry (BLI)-based SELEX for generation of high affinity aptamers against patulin. Unlike conventional SELEX, the present method enabled real-time monitoring of increasing affinity of the oligonucleotides to the toxin. After seven rounds of selection cycles, the enriched pool of aptamers was characterized by cloning and sequencing and clustered into two families based on similarity. Two sequences, PAT C3 and PAT C4, each belonging to different clades, were further evaluated for their binding affinity. SPR studies determined the dissociation constants (KD) of 8.2 × 10-8 and 1.9 × 10-7 M for aptamer PAT C3 and PAT C4, respectively. The highest affinity PAT C3 aptamer was used to develop a patulin BLI aptasensor, which indicated a linear detection range from 0.045 to 100 ng/mL [limit of detection (LOD) = 0.173 ng/mL; limit of quantification (LOQ) = 0.526 ng/mL]. The aptasensor displayed no cross-reactivity with its structural analogue isopatulin or any of the other mycotoxin groups tested. Spiking studies in simulated apple juice samples showed recoveries in the range of 82.11 to 100.23%, indicating good sensor performance. The study is the first report of BLI-based SELEX for a non-protein toxin, which resulted in the generation of high affinity aptamers and development of an aptasensor which can have wide application in the food industry for high throughput screening of samples for patulin contamination within a short span of time.
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Aptâmeros de Nucleotídeos , Malus , Patulina , Aptâmeros de Nucleotídeos/química , Humanos , Interferometria , Limite de Detecção , Malus/química , Técnica de Seleção de AptâmerosRESUMO
Background: Opportunistic cases of rhino-orbito-cerebral mucormycosis (ROCM) have increased in India during the coronavirus disease 2019 (COVID-19) pandemic. Aim: To study laboratory parameters, histopathological features of sinus mucosal biopsies and exenterated orbit specimens, and clinical aspects of patients with ROCM. Materials and methods: Retrospective analysis of nasal and sinus debridement biopsies and orbital exenteration specimens of 30 patients was undertaken, along with analysis of laboratory parameters, clinical history of predisposing conditions, and medication history during COVID-19. Results: All patients were either in recovery following COVID-19 or had ongoing infection. Most patients were diabetic with increased glycosylated haemoglobin, and most patients received steroids and antibiotics for COVID-19. Thirty sinonasal mucosal debridement specimens from various sites, nine orbital exenteration specimens and one frontal decompression craniectomy specimen were examined. Mucor spp. were observed in necrotic tissue, and the presence of vessel and nerve invasion was documented. There were four deaths. Conclusion: ROCM is a life-threatening disease. A high index of suspicion with prompt aggressive surgical and medical management by a multi-disciplinary team can be life saving. Efforts to maintain an optimal glycaemic index is likely to be helpful in preventing ROCM. Judicious use of steroids is mandatory to control the collateral epidemic of ROCM in India.
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Mass Spectrometric Imaging (MSI) is a molecular imaging technique that allows the generation of 2D ion density maps for a large complement of the active molecules present in cells and sectioned tissues. Automatic segmentation of such maps according to patterns of co-expression of individual molecules can be used for discovery of novel molecular signatures (molecules that are specifically expressed in particular spatial regions). However, current segmentation techniques are biased toward the discovery of higher abundance molecules and large segments; they allow limited opportunity for user interaction, and validation is usually performed by similarity to known anatomical features. We describe here a novel method, AMASS (Algorithm for MSI Analysis by Semi-supervised Segmentation). AMASS relies on the discriminating power of a molecular signal instead of its intensity as a key feature, uses an internal consistency measure for validation, and allows significant user interaction and supervision as options. An automated segmentation of entire leech embryo data images resulted in segmentation domains congruent with many known organs, including heart, CNS ganglia, nephridia, nephridiopores, and lateral and ventral regions, each with a distinct molecular signature. Likewise, segmentation of a rat brain MSI slice data set yielded known brain features and provided interesting examples of co-expression between distinct brain regions. AMASS represents a new approach for the discovery of peptide masses with distinct spatial features of expression. Software source code and installation and usage guide are available at http://bix.ucsd.edu/AMASS/ .
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Regulação da Expressão Gênica , Espectrometria de Massas/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Algoritmos , Animais , Encéfalo/metabolismo , Análise por Conglomerados , Biologia Computacional/métodos , Processamento Eletrônico de Dados , Regulação da Expressão Gênica no Desenvolvimento , Processamento de Imagem Assistida por Computador/métodos , Sanguessugas , Peptídeos/química , RatosRESUMO
MSI is a molecular imaging technique that allows for the generation of topographic 2D maps for various endogenous and some exogenous molecules without prior specification of the molecule. In this paper, we start with the premise that a region of interest (ROI) is given to us based on preselected morphological criteria. Given an ROI, we develop a pipeline, first to determine mass values with distinct expression signatures, localized to the ROI, and second to identify the peptides corresponding to these mass values. To identify spatially differentiated masses, we implement a statistic that allows us to estimate, for each spectral peak, the probability that it is over- or under-expressed within the ROI versus outside. To identify peptides corresponding to these masses, we apply LC-MS/MS to fragment endogenous (nonprotease digested) peptides. A novel pipeline based on constructing sequence tags de novo from both original and decharged spectra and a subsequent database search is used to identify peptides. As the MSI signal and the identified peptide are only related by a single mass value, we isolate the corresponding transcript and perform a second validation via in situ hybridization of the transcript. We tested our approach, MSI-Query, on a number of ROIs in the medicinal leech, Hirudo medicinalis, including the central nervous system (CNS). The Hirudo CNS is capable of regenerating itself after injury, thus forming an important model system for neuropeptide identification. The pipeline helps identify a number of novel peptides. Specifically, we identify a gene that we name HmIF4, which is a member of the intermediate filament family involved in neural development and a second novel, uncharacterized peptide. A third peptide, derived from the histone H2B, is also identified, in agreement with the previously suggested role of histone H2B in axon targeting.
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Processamento de Imagem Assistida por Computador/métodos , Espectrometria de Massas/métodos , Peptídeos/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sequência de Aminoácidos , Animais , Cromatografia Líquida/métodos , Bases de Dados de Proteínas , Hirudo medicinalis/anatomia & histologia , Hirudo medicinalis/química , Dados de Sequência Molecular , Peso MolecularRESUMO
We studied the kinetics of NADPH-dependent reduction of human CYP3A4 incorporated into Nanodiscs (CYP3A4-ND) and proteoliposomes in order to probe the effect of P450 oligomerization on its reduction. The flavin domain of cytochrome P450-BM3 (BMR) was used as a model electron donor partner. Unlike CYP3A4 oligomers, where only 50% of the enzyme was shown to be reducible by BMR, CYP3A4-ND could be reduced almost completely. High reducibility was also observed in proteoliposomes with a high lipid-to-protein ratio (L/P=910), where the oligomerization equilibrium is displaced towards monomers. In contrast, the reducibililty in proteoliposomes with L/P=76 did not exceed 55+/-6%. The effect of the surface density of CYP3A4 in proteoliposomes on the oligomerization equilibrium was confirmed with a FRET-based assay employing a cysteine-depleted mutant labeled on Cys-468 with BODIPY iodoacetamide. These results confirm a pivotal role of CYP3A4 oligomerization in its functional heterogeneity. Furthermore, the investigation of the initial phase of the kinetics of CYP3A4 reduction showed that the addition of NADPH causes a rapid low-to-high-spin transition in the CYP3A4-BMR complex, which is followed by a partial slower reversal. This observation reveals a mechanism whereby the CYP3A4 spin equilibrium is modulated by the redox state of the bound flavoprotein.
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Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/metabolismo , Flavinas/metabolismo , NADPH-Ferri-Hemoproteína Redutase/química , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Compostos de Boro , Citocromo P-450 CYP3A/genética , Transporte de Elétrons , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Humanos , Cinética , Mutação/genética , NADP/metabolismo , Nanotecnologia , Oxirredução , Proteolipídeos/metabolismo , Especificidade por SubstratoRESUMO
This study reports the selection of DNA aptamer for the detection of 20 Methyl Spirolide G (SPXG). After 10 rounds of selection, theenriched pool of aptamers specific to SPXGwas cloned, sequenced and clustered into seven families based onsimilarity. Three sequences SPX1, SPX2 and SPX7, each belonging to different clades were further evaluated for their binding affinity. Surface plasmonresonancestudies determined the highest affinity KDof 0.0345x10-8 M for aptamer SPX7. A label-free microscale thermophoresis-based aptasensing using SPX7 with highest affinity, indicated a linear detection range from 1.9 to 125000 pg/mL (LOD = 0.39 pg/mL; LOQ = 1.17 pg/mL). Spiking studies in simulated contaminated samples of mussel and scallop indicated recoveries in the range of 86 to 108%. Results of this study indicate the successful development of an aptamer for detection of SPXG at picogram levels. It also opens up avenues to develop other sensing platforms for detection of SPXG using the reported aptamer.
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Aptâmeros de Nucleotídeos , Compostos de Espiro , Humanos , Toxinas Marinhas , Técnica de Seleção de AptâmerosRESUMO
Coronavirus disease-associated mucormycosis (CAM) is an established clinical entity in India. In the past 4 months, there has been a sharp upsurge in the number of CAM cases in most parts of the country. Early diagnosis can be lifesaving. Magnetic resonance imaging (MRI) imaging remains the corner stone of management in patients with ROCM. This review discussed the utility of MRI imaging in ROCM with an emphasis on the ideal MRI protocol in a suspected case of ROCM, the pathways of spread of infection, the classic diagnostic features, MRI for staging of the disease, MRI for prognostication, MRI for follow up, and imaging features of common differentials in ROCM. The pit falls of MRI imaging and a comparison of CT and MRI imaging in ROCM are discussed. The clinical interpretation of areas of contrast uptake and those of necrosis and its relevance to treatment are discussed. This review aims to familiarize every member of the multidisciplinary team involved in managing these patients to be able to interpret the findings on MRI in ROCM.
Assuntos
Mucormicose , Doenças Nasais , Doenças Orbitárias , Antifúngicos/uso terapêutico , Humanos , Índia , Imageamento por Ressonância Magnética , Mucormicose/diagnóstico por imagem , Doenças Nasais/tratamento farmacológico , Doenças Orbitárias/diagnóstico por imagem , Doenças Orbitárias/tratamento farmacológicoRESUMO
There is a unique microbial community in the female lower genital tract known as the vaginal microbiota, which varies in composition and density and provides significant benefits during pregnancy, reproductive cyclicity, healthy newborn delivery, protection from preterm birth, infections such as UTIs, bacterial vaginosis, and so on, and improves the efficacy of treatments for vaginal cancers. Methods: It is necessary to know how the vaginal microbiome is composed in order to make an accurate diagnosis of the diseases listed above. A microbiome's members are difficult to classify, and the way microbial communities function and influence host-pathogen interactions are difficult to understand. More and more metagenomic studies are able to unravel such complexities due to advances in high-throughput sequencing and bioinformatics. When it comes to vaginal microbiota research, we'll be looking at the use of modern techniques and strategies that can be used to investigate variations in vaginal microbiota in order to detect diseases earlier, better treat vaginal disorders, and boost women's health. Discussion: The discussed techniques and strategies may improve the treatment of vaginal disorders and may be beneficial for women's overall health.