41 research outputs found

    Recombinant antibodies against Clostridium difficile toxin A

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    The carboxy-terminal region of Clostridium difficile Toxin A was expressed as a recombinant protein (ToxinA-CT), purified, and shown to behave as would be expected of the receptor-binding domain. ToxinA-CT was then used to isolate scFv antibodies from a phage display library using conventional bio-panning methods. Progressive enrichment of ToxinA-CT-specific scFvs through 3 rounds of selection was observed. Those scFvs that showed strongest reaction with ToxinA-CT in ELISA were sequenced, expressed as soluble antibodies and purified. A panel of diverse scFvs was established that appeared to bind to non-overlapping epitopes on ToxinA-CT. To assay for protective activity, scFvs were mixed with native Toxin A, added to cells in culture, and the response monitored over a 2 hour period. The scFvs were added to consistently delay the cytopathic activity of Toxin A but were unable to match the neutralizing activity of a polyclonal serum or its Fab derivatives. The epitopes recognised by the scFvs were localized using a sub-cloning strategy. Defined parts of the ToxinA-CT reading frame were recovered by PCR and fusions created with maltose binding protein. scFvs were tested for recognition of the maltose binding fusion proteins. In one instance, a scFv reacted with multiple fusion proteins suggesting recognition of a repeated peptide motif. A maltose binding protein fusion carrying a candidate sequence was successfully recognised by this scFv. Overall, phage display enabled assembly of a panel of scFv antibodies against epitopes in the carboxy-terminal domain of Toxin A. The inability of these antibodies to block the activity of Toxin A may be due to the multivalent interaction between the toxin and its receptor. Alternatively, the ToxinA-CT used in scFv isolated may lack functions that are crucial for receptor interaction and hence potential targets for antibody-mediated inhibition

    Optimising Wound Closure Following a Fasciotomy: A narrative review

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    Compartment syndrome is a surgical emergency that could be resolved by a fasciotomy. However, performing substantial skin incisions may lead to life-threatening complications. This narrative review aimed to present the available methods of wound closure and preferential factors for using each technique. Viable and noninfected wounds were most often treated by gradual approximation techniques, such as the simple or modified shoelace technique, the prepositioned intracutaneous suture or several commercially-available mechanical devices. In addition, applying negative pressure therapy was found to be feasible, particularly when combined with approximation techniques. Skin grafting was reserved for severely-dehiscent wounds while other non-invasive approaches were considered for other subsets of patients with inadvisable surgical interventions. Treatment decision should be made in view of the patient’s condition, ease of application, availability of resources, cost of treatment and aesthetic outcomes.Keywords: Compartment Syndrome; Fasciotomy; Wound Closure Techniques; Negative-Pressure Wound Therapy

    The Effectiveness of Ga Percent on the Electrical Characteristics of Al/CuIn1-xGaxSe2/ITO Schottky Junctions

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    The electrodeposition method has been employed to deposit our quaternary semiconductor thin films CuIn1-xGaxSe2 (CIGS) which is deposited on Indium Tin Oxide (ITO) substrates with different Gallium ratios (x=0, 0.2, 0.4, 0.6, 0.8 and 1). The structural and optical characteristics variation of the films with altering Ga percent has been studied. The impact of changing the Ga/(In+Ga) atomic ratio on the electrical transport characteristics of electrodeposited CIGS thin films has been investigated using I-V and C-V measurements. All junctions have revealed the Schottky behavior. The energy gap of the studied compositions has increased with increasing Ga content. This lowered the values of charge mobility in the investigated films. Besides, the optimum Ga/(In+Ga) atomic proportion in the view of the obtained results is achieved by adding Ga with 20 %. Also, this finding approves the validation of our proposed criterion in expecting the most efficient photovoltaic junctions. The obtained results could improve our current knowledge of the quaternary photovoltaic solar cells

    Integrated Pangenome Analysis and Pharmacophore Modeling Revealed Potential Novel Inhibitors against Enterobacter xiangfangensis

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    Enterobacter xiangfangensis is a novel, multidrug-resistant pathogen belonging to the Enterobacter genus and has the ability to acquire resistance to multiple antibiotic classes. However, there is currently no registered E. xiangfangensis drug on the market that has been shown to be effective. Hence, there is an urgent need to identify novel therapeutic targets and effective treatments for E. xiangfangensis. In the current study, a bacterial pan genome analysis and subtractive proteomics approach was employed to the core proteomes of six strains of E. xiangfangensis using several bioinformatic tools, software, and servers. However, 2611 nonredundant proteins were predicted from the 21,720 core proteins of core proteome. Out of 2611 nonredundant proteins, 372 were obtained from Geptop2.0 as essential proteins. After the subtractive proteomics and subcellular localization analysis, only 133 proteins were found in cytoplasm. All cytoplasmic proteins were examined using BLASTp against the virulence factor database, which classifies 20 therapeutic targets as virulent. Out of these 20, 3 cytoplasmic proteins: ferric iron uptake transcriptional regulator (FUR), UDP-2,3diacylglucosamine diphosphatase (UDP), and lipid-A-disaccharide synthase (lpxB) were chosen as potential drug targets. These drug targets are important for bacterial survival, virulence, and growth and could be used as therapeutic targets. More than 2500 plant chemicals were used to molecularly dock these proteins. Furthermore, the lowest-binding energetic docked compounds were found. The top five hit compounds, Adenine, Mollugin, Xanthohumol C, Sakuranetin, and Toosendanin demonstrated optimum binding against all three target proteins. Furthermore, molecular dynamics simulations and MM/GBSA analyses validated the stability of ligand–protein complexes and revealed that these compounds could serve as potential E. xiangfangensis replication inhibitors. Consequently, this study marks a significant step forward in the creation of new and powerful drugs against E. xiangfangensis. Future studies should validate these targets experimentally to prove their function in E. xiangfangensis survival and virulence

    Impact of Aspiration in the Assessing Process of Pediatric Lung Disease

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    This study aimed at analyzing the impact of Aspiration in the assessing process of pediatric lung disease, as the affected children will frequently encounter a situation where swallowing is insecure and aspiration is likely. Besides analyzing the Aspiration of foreign matter into the airways and lungs that can cause a wide spectrum of pulmonary disorders with various presentations. And discussing the type of syndrome resulting from aspiration depends on the quantity and nature of the aspirated material, the chronicity, and the host responses. Considering that Aspiration is most likely to occur in subjects with a decreased level of consciousness, compromised airway defense mechanisms, dysphagia, gastroesophageal reflux, and recurrent vomiting

    Association Between Race/Ethnicity and Survival of Melanoma Patients in the United States Over 3 Decades

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    Melanoma is a treatable and preventable skin cancer. It is responsible for 75% of deaths among all skin cancers. Previous studies have found that race/ethnicity may play a role in survival among melanoma patients. However, there are no studies that cover 30 years and take race into account for the U.S. population. This study is a secondary analysis of the National Cancer Institute\u27s Surveillance, Epidemiology, and End Result (SEER) Program. Adults with primary cutaneous melanoma from 1982 to 2011 were included; the final sample size was 185,219. The outcome was survival; both cause-specific and all-cause mortality were examined. The main exposure was race/ethnicity. Kaplan?Meier survival analysis was used to estimate overall survival. Cox proportional hazards regression was used to estimate unadjusted and adjusted hazard ratios (HRs). A P-value less than 0.05 was considered statistically significant. More than 50% of patients in all races/ethnicities were diagnosed at the in situ or localized stage. Non-Hispanic White patients were more frequently diagnosed at the in situ stage. Overall, more men were diagnosed than women. The majority of cases among all races were men. Non-Hispanic Black females represented the smallest percentage of melanoma cases among all races. The smallest number of diagnoses across all races/ethnicities was made from 1982 to 1991. Median follow-up was 81 months and no collinearity was observed in the adjusted models. When examining cause-specific mortality and controlling for site and stage at diagnosis, gender, age and decade of diagnosis, the HR for non-Hispanic Black patients was lower than that for non-Hispanic White patients (HR 0.7; 95% confidence interval (CI): 0.6?0.8). However, when examining all-cause mortality, this difference disappeared (HR 1.1; 95% CI: 1.0?1.2). Stage at diagnosis impacted HR; patients diagnosed with distant metastases had significantly worse survival. When taking cause-specific mortality into consideration and after controlling for stage and site at diagnosis, gender, and age and decade of diagnosis, non-Hispanic Black patients had a lower HR compared to non-Hispanic White patients. However, this difference disappeared when examining all-cause mortality. Further research is needed to explore this finding and to determine what factors may be associated with late-stage melanoma diagnosis

    Comparison of Generalized Anxiety and Sleep Disturbance among Frontline and Second-Line Healthcare Workers during the COVID-19 Pandemic

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    Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection, also known as COVID-19, has developed into an alarming situation around the world. Healthcare workers are playing the role of frontline defense to safeguard the lives of everyone during the COVID-19 pandemic. The present study aimed to investigate the anxiety levels and sleep quality among frontline and second-line healthcare workers during the COVID-19 pandemic. In this cross-sectional study, a validated, self-administered, electronic questionnaire was distributed through email to healthcare workers. The selection of 1678 healthcare workers was based on a convenience sampling technique. The General Anxiety Disorder-7 (GAD-7) and Pittsburgh Sleep Quality Index (PSQI) instrument scales were used to assess healthcare workers’ anxiety levels and sleep quality during the COVID-19 pandemic. Out of 1678 respondents, 1200 (71.5%) were frontline healthcare workers, while 478 (28.5%) were second-line healthcare workers. Among all the healthcare workers, 435 (25.92%) were experiencing moderate to severe anxiety. Among them, 713 (59.4%) frontline healthcare workers were experiencing anxiety in comparison with 277 (57.9%) second-line healthcare workers. Severe anxiety symptoms were seen in 137 (11.41%) frontline healthcare workers compared to 44 (9.20%) second-line healthcare workers. In total, 1376 (82.0%) healthcare workers were found to have poor sleep quality; 975 (58.10%) were frontline, and 407 (23.89%) were second-line healthcare workers. The highest poor sleep quality levels were found among 642 (84.6%) of the healthcare workers who work in frontline areas (emergency departments, intensive care units, and wards) compared to 734 (79.9%) of the healthcare workers who work in second-line areas. These findings provide a substantial contribution to the consolidation of evidence concerning the negative impact of the pandemic on the mental health of healthcare workers (HCWs). These results have established an association that the COVID-19 pandemic causes larger negative psychological symptoms in frontline healthcare workers, such as severe anxiety and poor sleep quality. Preventive measures to minimize anxiety levels and maintain sleep quality, addressing this issue nationally and globally, are essential to support the healthcare workers who are sacrificing their mental health for the future of our nations

    Covalent Organic Framework (C6N6) as a Drug Delivery Platform for Fluorouracil to Treat Cancerous Cells: A DFT Study

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    Continuous studies are being carried out to explore new methods and carrier surfaces for target drug delivery. Herein, we report the covalent triazine framework C6N6 as a drug delivery carrier for fluorouracil (FU) and nitrosourea (NU) anti-cancer drugs. FU and NU are physiosorbed on C6N6 with adsorption energies of −28.14 kcal/mol and −27.54 kcal/mol, respectively. The outcomes of the non-covalent index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses reveal that the FU@C6N6 and NU@C6N6 complexes were stabilized through van der Waals interactions. Natural bond order (NBO) and electron density difference (EDD) analyses show an appreciable charge transfer from the drug and carrier. The FU@C6N6 complex had a higher charge transfer (−0.16 e−) compared to the NU@C6N6 complex (−0.02 e−). Frontier molecular orbital (FMO) analysis reveals that the adsorption of FU on C6N6 caused a more pronounced decrease in the HOMO-LUMO gap (EH-L) compared to that of NU. The results of the FMO analysis are consistent with the NBO and EDD analyses. The drug release mechanism was studied through dipole moments and pH effects. The highest decrease in adsorption energy was observed for the FU@C6N6 complex in an acidic medium, which indicates that FU can easily be off-loaded from the carrier (C6N6) to a target site because the cancerous cells have a low pH compared to a normal cell. Thus, it may be concluded that C6N6 possesses the therapeutic potential to act as a nanocarrier for FU to treat cancer. Furthermore, the current study will also provide motivation to the scientific community to explore new surfaces for drug delivery applications

    Correlating Orbital Composition and Activity of LaMnxNi1-xO3 Nanostructures Towards Oxygen Electrocatalysis

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    The atomistic rationalization of the activity of transition metal oxides towards oxygen electrocatalysis is one of the most complex challenges in the field of electrochemical energy conversion. Transition metal oxides exhibit a wide range of structural and electronic properties, which are acutely dependent on composition and crystal structure. So far, identifying one or several properties of transition metal oxides as descriptors for oxygen electrocatalysis remains elusive. In this work, we performed a detailed experimental and computational study of LaMnxNi1-xO3 perovskites nanostructures, establishing an unprecedented correlation between electrocatalytic activity and orbital composition. The composition and structure of the single-phase rhombohedral oxide nanostructures are characterized by a variety of techniques, including X-ray diffraction, X-ray absorption spectroscopy, X-ray photoelectron spectroscopy and electron microscopy. Systematic electrochemical analysis of pseudocapacitive responses in the potential region relevant to oxygen electrocatalysis shows the evolution of Mn and Ni d-orbitals as a function of the perovskite composition. We rationalize these observations on the basis of electronic structure calculations employing DFT with HSE06 hybrid functional. Our analysis clearly shows a linear correlation between the OER kinetics and the integrated density of states (DOS) associated with Ni and Mn 3d states in the energy range relevant to operational conditions. On the other hand, the ORR kinetics exhibits a second-order reaction with respect to the electron density in Mn and Ni 3d states. For the first time, our study identifies the relevant DOS dominating both reactions and the importance of understanding orbital occupancy under operational conditions
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