Correlation between Nonlinear Optical Effects and Structural Features of Aurone-Based Methacrylic Polymeric Thin Films

In this study, new photonics architectures and aurone-based methacrylic polymers were designed and synthesized for their optical and nonlinear optical properties. The studied polymeric thin films were deposited by spin coating method. SHG and THG effects were measured via Maker fringe technique in transmission mode and determined using theoretical models. Investigations involved the theoretical quantum chemical calculation of dipole moments, frontier molecular orbital HOMO and LUMO energies, and first (β) and second (γ) hyperpolarizabilities. We determined the impact of the substitution in the para position of the phenyl ring and at the dipole moment of the chromophore on the nonlinear optical properties of the investigated polymers. The presented theoretical and experimental studies provide important information with respect to the design of methacrylic-based polymeric thin film devices and supplement existing knowledge with respect to their nonlinear behaviour.     

Efficacy of Tocilizumab Therapy in Different Subtypes of COVID-19 Cytokine Storm Syndrome

Background: Cytokine storm in COVID-19 is heterogenous. There are at least three subtypes: cytokine release syndrome (CRS), macrophage activation syndrome (MAS), and sepsis. Methods: A retrospective study comprising 276 patients with SARS-CoV-2 pneumonia. All patients were tested for ferritin, interleukin-6, D-Dimer, fibrinogen, calcitonin, and C-reactive protein. According to the diagnostic criteria, three groups of patients with different subtypes of cytokine storm syndrome were identified: MAS, CRS or sepsis. In the MAS and CRS groups, treatment results were assessed depending on whether or not tocilizumab was used. Results: MAS was diagnosed in 9.1% of the patients examined, CRS in 81.8%, and sepsis in 9.1%. Median serum ferritin in patients with MAS was significantly higher (5894 vs. 984 vs. 957 ng/mL, p < 0.001) than in those with CRS or sepsis. Hypofibrinogenemia and pancytopenia were also observed in MAS patients. In CRS patients, a higher mortality rate was observed among those who received tocilizumab, 21 vs. 10 patients (p = 0.043), RR = 2.1 (95% CI 1.0–4.3). In MAS patients, tocilizumab decreased the mortality, 13 vs. 6 patients (p = 0.013), RR = 0.50 (95% CI 0.25–0.99). Conclusions: Tocilizumab therapy in patients with COVID-19 and CRS was associated with increased mortality, while in MAS patients, it contributed to reduced mortality.     

Agglutination of Pseudomonas aeruginosa by surfactant protein D

Surfactant protein D (SP-D) is part of the innate host defense system, and may bind and agglutinate invading microorganisms to enhance their removal. The ability of bronchoalveolar lavage (BAL) fluid to agglutinate bacteria and the relationship to its SP-D content are of interest and not yet known. A micromethod on slides was used to assess the agglutination of Pseudomonas aeruginosa by recombinant SP-D and native human BAL fluid. The SP-D-induced agglutination was blocked by calcium depletion, alkaline pH, or the presence of maltose. Twenty-three of 30 BAL fluids from outpatients carrying a chronic tracheostoma clearly agglutinated P. aeruginosa, which was completely inhibited by maltose. The extent of the agglutination correlated weakly to the concentration of SP-D in the BAL fluid, but not to that of SP-A. The functional property, i.e., the agglutination of P. aeruginosa by BAL fluid, was characterized and appeared related in part to the concentration of SP-D. Additional factors, such as the multimeric organization of SP-D, are likely to contribute to the agglutination of microorganisms by BAL or other body fluids. The assay presented will allow the systematic evaluation of small-volume samples for SP-D agglutinating ability from subjects with various lung diseases.     

Inhibition of microglial inflammatory responses by norepinephrine: effects on nitric oxide and interleukin-1beta production

BACKGROUND: Under pathological conditions, microglia produce proinflammatory mediators which contribute to neurologic damage, and whose levels can be modulated by endogenous factors including neurotransmitters such as norepinephrine (NE). We investigated the ability of NE to suppress microglial activation, in particular its effects on induction and activity of the inducible form of nitric oxide synthase (NOS2) and the possible role that IL-1beta plays in that response. METHODS: Rat cortical microglia were stimulated with bacterial lipopolysaccharide (LPS) to induce NOS2 expression (assessed by nitrite and nitrate accumulation, NO production, and NOS2 mRNA levels) and IL-1beta release (assessed by ELISA). Effects of NE were examined by co-incubating cells with different concentrations of NE, adrenergic receptor agonists and antagonists, cAMP analogs, and protein kinase (PK) A and adenylate cyclase (AC) inhibitors. Effects on the NFkappaB:IkappaB pathway were examined by using selective a NFkappaB inhibitor and measuring IkappaBalpha protein levels by western blots. A role for IL-1beta in NOS2 induction was tested by examining effects of caspase-1 inhibitors and using caspase-1 deficient cells. RESULTS: LPS caused a time-dependent increase in NOS2 mRNA levels and NO production; which was blocked by a selective NFkappaB inhibitor. NE dose-dependently reduced NOS2 expression and NO generation, via activation of beta2-adrenergic receptors (beta2-ARs), and reduced loss of inhibitory IkBalpha protein. NE effects were replicated by dibutyryl-cyclic AMP. However, co-incubation with either PKA or AC inhibitors did not reverse suppressive effects of NE, but instead reduced nitrite production. A role for IL-1beta was suggested since NE potently blocked microglial IL-1beta production. However, incubation with a caspase-1 inhibitor, which reduced IL-1beta levels, had no effect on NO production; incubation with IL-receptor antagonist had biphasic effects on nitrite production; and NE inhibited nitrite production in caspase-1 deficient microglia. CONCLUSIONS: NE reduces microglial NOS2 expression and IL-1beta production, however IL-1beta does not play a critical role in NOS2 induction nor in mediating NE suppressive effects. Changes in magnitude or kinetics of cAMP may modulate NOS2 induction as well as suppression by NE. These results suggest that dysregulation of the central cathecolaminergic system may contribute to detrimental inflammatory responses and brain damage in neurological disease or trauma.     

Sensing prothymosin alpha origin,mutations and conformation with monoclonal antibodies

To overcome poor immunogenicity of prothymosin alpha, a small and highly acidic nuclear protein involved in cell proliferation, production of anti-prothymosin alpha antibodies in mice immunized with free human prothymosin alpha, with prothymosin alpha coupled to different carriers and with prothymosin alpha fused to green fluorescent protein was assessed. Fusing prothymosin alpha to green fluorescent protein turned out to be the superior approach resulting in production of high titer anti-prothymosin alpha antibodies. From these studies, two highly specific anti-prothymosin alpha monoclonal antibodies recognizing epitopes within the amino terminal (2F11) and middle (4F4) portions of the human prothymosin alpha molecule were obtained and characterized. As expected, the 2F11 antibody displayed broad species specificity, whereas the 4F4 antibody appeared to be species-specific permitting discrimination of human versus rat protein. Furthermore, a combination of point mutations in prothymosin alpha that alter the properties of the protein precluded recognition by the 4F4 antibody. Intramolecular masking of the 4F4 epitope in prothymosin alpha fused to the Tat transduction peptide of human immunodeficiency virus type 1 was observed. The anti-prothymosin alpha antibodies obtained were suitable for precipitation of human prothymosin alpha from HeLa cell lysates and for immunolocalization of the endogenous prothymosin alpha within the cells. Fusion with green fluorescent protein may thus be helpful in raising antibodies against 'problematic' proteins.     

Tombusvirus genome may encode the sixth small protein near its 3′ terminus

A short open reading frame (ORF), ORF6, potentially encoding a polypeptide (pX) of 32–69 amino acids, was revealed upon computer translation of the 3 terminal regions of tomato bushy stunt, cymbidium ringspot, cucumber necrosis, and artichoke mottled crinkle tombusviruses. ORF6 has an initiating AUG codon in a favorable context and is evaluated as expressible, judging the distribution of guanosine residues within the codons. Inspection of the alignment of the four putative products encoded by ORF6 shows statistically significant sequence conservation over 11 SD above the random expectation. Secondary structure predictions based on the Garnier method demonstrate strict conservation of a loop between two -strands, thus suggesting functional conservation of pXs. It is suggested that pX is not involved in tombusvirus genome replication and encapsidation incis.     

Doxorubicin sensitizes human tumor cells to NK cell‐ and T‐cell‐mediated killing by augmented TRAIL receptor signaling

Doxorubicin (DOX) is an anthracycline antibiotic that is widely used to treat different types of malignancy. In this study, it was studied whether DOX could be used to render tumor cells susceptible to apoptosis by NK and T cells. Pretreatment with subapoptotic doses of DOX sensitized tumor cell lines of various histotypes to both NK and T cells resulting in a 3.7 to 32.7% increase in lysis (2.5 mean fold increase, p < 0.0001) and a 2.9 to 14.2% increase in lysis (3.0 mean‐fold increase, p < 0.05), respectively. The sensitizing effect of the drug was primarily dependent on the tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL)/TRAIL‐receptor signaling, but not on Fas‐ligand, perforin, NKG2D or DNAM‐1. The central role of the TRAIL signaling pathway was further supported by an increased expression of TRAIL‐R2 on DOX‐treated tumor cells and by downregulation of cellular FLICE inhibitory protein, the inhibitors of death receptor‐mediated apoptosis. Compared to untreated cells, pretreatment of tumor cells with DOX showed increased processing and activation of caspase‐8 on coculture with NK or T cells. The significance of this treatment strategy was confirmed using a xenogeneic tumor‐bearing mouse model. Tumor progression was delayed in mice that received either NK cells (p < 0.05) or T cells (p < 0.0001) following DOX treatment compared to mice receiving either cell type alone. Moreover, combined infusion of both NK and T cells following DOX treatment not only delayed tumor progression but also significantly improved the long‐term survival (p < 0.01). Based on these findings, it was proposed that DOX can be used to improve the efficacy of adoptive cell therapy in patients with cancer.