Bacterial pathogens are known to pester Mankind from times immemorial; even though significant efforts in getting rid of these harmful microbes have been made the results are very faint with only few organisms that have been eradicated, such as Small pox virus. But the efforts to eradicate bacterial diseases have shown no passable results as in case of viruses. This is due to the exceptional adaptation and transformation abilities of bacteria to varying environmental Conditions. Though a large number of antibiotics are being used from decades now, there are no affirmative solutions available due to resistance developed towards antibiotics by these bacteria. This resistance developed by the bacteria calls for dire necessity to discover new drugs which can at least reduce the hazards posed by these microbes if not eradication. Hence in this study we have focused on bio prospecting of Clerodendrum paniculatum and Saraca asoka against the highly virulent and extremely adaptable organisms E. coli and K. pneumoniae which currently pose a severe threat to humans due to their acquired resistance to large number of antibiotics.
This study explores the molecular structuring of salmon gelatin (SG) with controlled molecular weight produced from salmon skin, and its relationship with its thermal and rheological properties. SG was produced under different pH conditions to produce samples with well-defined high (SGH), medium (SGM), and low (SGL) molecular weight. These samples were characterized in terms of their molecular weight (MW, capillary viscometry), molecular weight distribution (electrophoresis), amino acid profile, and Raman spectroscopy. These results were correlated with thermal (gelation energy) and rheological properties. SGH presented the higher MW (173 kDa) whereas SGL showed shorter gelatin polymer chains (MW < 65 kDa). Raman spectra and gelation energy suggest that amount of helical structures in gelatin is dependent on the molecular weight, which was well reflected by the higher viscosity and G′ values for SGH. Interestingly, for all the molecular weight and molecular configuration tested, SG behaved as a strong gel (tan δ < 1), despite its low viscosity and low gelation temperature (3–10 °C). Hence, the molecular structuring of SG reflected directly on the thermal and viscosity properties, but not in terms of the viscoelastic strength of gelatin produced. These results give new insights about the relationship among structural features and macromolecular properties (thermal and rheological), which is relevant to design a low viscosity biomaterial with tailored properties for specific applications.
The Pfizer-BioNTech COVID-19 vaccine has been authorized by the U.S. Food and Drug Administration as it demonstrated 95% effectiveness against the SARS-CoV-2 virus. Although the initial vaccine trials showed a favorable side effect profile, there have been concerns regarding activation of aberrant immune responses, triggering autoimmunity. This is a case report of a 68-year-old woman without history of autoimmune conditions, who presented to our emergency department 7 days after receiving the Pfizer-BioNTech COVID-19 vaccine. Her initial symptoms were suggestive of polymyalgia rheumatica, and she had nearly complete response to steroids. Interestingly, she later met criteria for classified systemic lupus erythematous given the development of inflammatory arthritis, positive ANA, and positive dsDNA. The temporal relationship of her symptoms that started 2 days after vaccine administration could suggest a possible association between the Pfizer-BioNTech COVID-19 and the development of systemic lupus erythematous.
Among the mechanisms of suppression that T regulatory (Treg) cells exert to control the immune responses, the secretion of small extracellular vesicles (sEV) has been recently proposed as a novel contact‐independent immunomodulatory mechanism. Previous studies have demonstrated that Treg cells produce sEV, including exosomes, able to modulate the effector function of CD4+ T cells, and antigen presenting cells (APCs) such as dendritic cells (DCs) through the transfer of microRNA, cytokines, the production of adenosine, among others. Previously, we have demonstrated that Neuropilin‐1 (Nrp1) is required for Tregs‐mediated immunosuppression mainly by impacting on the phenotype and function of effector CD4+ T cells. Here, we show that Foxp3+ Treg cells secrete sEV, which bear Nrp1 in their membrane. These sEV modulate effector CD4+ T cell phenotype and proliferation in vitro in a Nrp1‐dependent manner. Proteomic analysis indicated that sEV obtained from wild type (wt) and Nrp1KO Treg cells differed in proteins related to immune tolerance, finding less representation of CD73 and Granzyme B in sEV obtained from Nrp1KO Treg cells. Likewise, we show that Nrp1 is required in Treg cell‐derived sEV for inducing skin transplantation tolerance, since a reduction in graft survival and an increase on M1/M2 ratio were found in animals treated with Nrp1KO Treg cell‐derived sEV. Altogether, this study describes for the first time that Treg cells secrete sEV containing Nrp1 and that this protein, among others, is necessary to promote transplantation tolerance in vivo via sEV local administration.
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