Spontaneous formation of complex structures made from elastic membranes in an aluminum-hydroxide-carbonate system

A popular playground for studying chemo-hydrodynamic patterns and instabilities is chemical gardens, also known as silicate gardens. In these systems, complex structures spontaneously form, driven by buoyant forces and either osmotic or mechanical pumps. Here, we report on systems that differ somewhat from classical chemical gardens in that the membranes are much more deformable and soluble. These properties lead to structures that self-construct and evolve in new ways. For example, they exhibit the formation of chemical balloons, a new growth mechanism for tubes, and also the homologous shrinking of these tubes. The stretching mechanism for the membranes is probably different than for other systems by involving membrane "self-healing." Other unusual properties are osmosis that sometimes occurs out of the structure and also small plumes that flow away from the structure, sometimes upwards, and sometimes downwards. Mathematical models are given that explain some of the observed phenomena.

The influence of stabilizers on the production of gold nanoparticles by direct current atmospheric pressure glow microdischarge generated in contact with liquid flowing cathode

Gold nanoparticles (Au NPs) were prepared by direct current atmospheric pressure glow microdischarge (dc-μAPGD) generated between a miniature argon flow microjet and a flowing liquid cathode. The applied discharge system was operated in a continuous flow liquid mode. The influence of various stabilizers added to the solution of the liquid cathode, i.e., gelatin (GEL), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA), as well as the concentration of the Au precursor (chloroauric acid, HAuCl₄) in the solution on the production growth of Au NPs was investigated. Changes in the intensity of the localized surface plasmon resonance (LSPR) band in UV/Vis absorption spectra of solutions treated by dc-μAPGD and their color were observed. The position and the intensity of the LSPR band indicated that relatively small nanoparticles were formed in solutions containing GEL as a capping agent. In these conditions, the maximum of the absorption LSPR band was at 531, 534, and 535 nm, respectively, for 50, 100, and 200 mg L^-1 of Au. Additionally, scanning electron microscopy (SEM) and dynamic light scattering (DLS) were used to analyze the structure and the morphology of obtained Au NPs. The shape of Au NPs was spherical and uniform. Their mean size was ca. 27, 73, and 92 nm, while the polydispersity index was 0.296, 0.348, and 0.456 for Au present in the solution of the flowing liquid cathode at a concentration of 50, 100, and 200 mg L^-1, respectively. The production rate of synthesized Au NPs depended on the precursor concentration with mean values of 2.9, 3.5, and 5.7 mg h^-1, respectively.

Low levels of microbial translocation marker LBP are associated with sustained viral response after anti-HCV treatment in HIV-1/HCV co-infected patients

BACKGROUND

Microbial translocation (MT) contributes to immune activation during HIV and HCV infections. We investigated the kinetics of MT markers during anti-HCV and anti-HIV treatments, and if baseline plasma levels of lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP) and soluble CD14 (sCD14) could predict anti-HCV treatment outcome.

METHODS

Plasma from 78 HIV-infected patients was evaluated for LPS, LBP and sCD14. The patients starting anti-HCV treatment (with ongoing antiretroviral (ART) treatment) were categorized into sustained viral responders (SVR; n = 21) or non-responders (NR; n = 15) based on treatment outcome. ART starting subjects--were categorized into chronically HCV-infected (CH; n = 24) and mono-infected (HIV; n = 18), based on the HCV infection status. Samples were collected before start (at baseline) of pegylated-interferon-alpha/ribavirin (peg-IFN/RBV) or antiretroviral-therapy and two years after treatment start (at follow up). χ2-test, non-parametric statistics and logistic regression were applied to determine the associations with treatment response and changes of the soluble markers.

RESULTS

Plasma levels of LPS and sCD14 were elevated in all subjects before antiviral-treatment but remained unchanged at follow-up. Elevated levels of LBP were present in patients with HIV and HIV/HCV co-infection and were reduced by ART. Additionally, higher levels of LBP were present at baseline in NR vs. SVR. Higher levels of LBP at baseline were associated with non-response to peg-IFN/RBV treatment in both bivariate (OR: 0.19 95% CI: 0.06-0.31, p = 0.004) and multivariate analysis (OR: 1.43, 95% CI: 1.1-1.86, p = 0.07).

CONCLUSION

In HIV/HCV co-infected patients high baseline LBP levels are associated with non-response to peg-IFN/RBV therapy. Plasma LBP (decreased by ART) may be a more relevant MT marker than LPS and sCD14.

Towards multifunctional MOFs – transforming a side reaction into a post-synthetic protection/deprotection method

Controlled formylation/deformylation of the important amino-substituted metal–organic framework UiO-66-NH₂ allowed for the first successful post-synthetic protection–modification–deprotection sequences in MOFs.

An allosteric receptor by simultaneous "casting" and "molding" in a dynamic combinatorial library

Allosteric synthetic receptors are difficult to access by design. Herein we report a dynamic combinatorial strategy towards such systems based on the simultaneous use of two different templates. Through a process of simultaneous casting (the assembly of a library member around a template) and molding (the assembly of a library member inside the binding pocket of a template), a Russian-doll-like termolecular complex was obtained with remarkable selectivity. Analysis of the stepwise formation of the complex indicates that binding of the two partners by the central macrocycle exhibits significant positive cooperativity. Such allosteric systems represent hubs that may have considerable potential in systems chemistry.

Addition of strawberries to the usual diet decreases resting chemiluminescence of fasting blood in healthy subjects-possible health-promoting effect of these fruits consumption

OBJECTIVE

Regular strawberry consumption augmented plasma antioxidant activity and decreased lipid peroxidation suggests preventive potential of these fruits against oxidative stress-dependent disorders. Blood phagocytes are important source of oxidants that may contribute to systemic oxidative stress. We examined the effect of strawberry consumption on the luminol enhanced whole blood chemiluminescence (LBCL) reflecting oxidants generation by circulating phagocytes in healthy subjects.

METHODS

Thirty-one healthy subjects (being on their usual diet) consumed 500 g of strawberry pulp daily (between 11.00-14.00) for 30 days (1st strawberry course) and after 10 day wash-out the cycle was repeated (2nd strawberry course). Fasting blood and spot morning urine samples were collected before and after each strawberry course for measuring resting and agonist (fMLP)-induced LBCL, various phenolics and plasma antioxidant activity. Twenty subjects served as a control in respect to LBCL changes over the study period.

RESULTS

Strawberry consumption decreased median resting LBCL and this effect was more evident after the 1st course (by 38.2%, p < 0.05) than after the the 2nd one (18.7%), while fMLP-induced LBCL was constant. No changes in LBCL were noted in controls. Strawberries increased fasting plasma levels of caffeic acid and homovanillic acid as well as urolithin A and 4-hydroxyhippuric acid in spot urine. Plasma antioxidant activity and the number of circulating phagocytes did not change over the study period. Resting LBCL correlated positively with the number of circulating polymorphonuclear leukocytes at all occasions and negative correlation with plasma 4-hydroxyhippuric acid was noted especially after the first strawberry course (r = -0.46, p < 0.05).

CONCLUSIONS

The decrease in resting LBCL suggests that regular strawberry consumption may suppress baseline formation of oxidants by circulating phagocytes. This may decrease the risk of systemic imbalance between oxidants and anti-oxidants and be one of mechanisms of health-promoting effect of these fruits consumption.

Emergence of complex behavior in chemical cells: the system AlCl₃-NaOH

Chemical cells that spontaneously form in simple inorganic systems are presented. The cells are surrounded by semipermeable membranes that allow water and some ions to diffuse through. These cells exhibit dynamical behaviors that are typically associated with biological entities. These behaviors may be used to perform tasks such as rotation or linear translation in the vertical and horizontal directions. Yet another system builds "curtains". Behaviors are controlled by a complex network of physical and chemical processes that are organized in space and time. The type of dynamical behavior is determined by the chemical composition of the cell and the environment. By studying these systems we may learn general rules for the growth of living entities, or at least about the spontaneous growth of complex chemical structures. Understanding and mastering the synthesis of these systems may lead to new technologies where complex structures are grown rather than assembled.

Multiparametric bioinformatics distinguish the CD4/CD8 ratio as a suitable laboratory predictor of combined T cell pathogenesis in HIV infection

HIV disease progression is characterized by numerous pathological changes of the cellular immune system. Still, the CD4 cell count and viral load represent the laboratory parameters that are most commonly used in the clinic to determine the disease progression. In this study, we conducted an interdisciplinary investigation to determine which laboratory parameters (viral load, CD4 count, CD8 count, CD4 %, CD8 %, CD4/CD8) are most strongly associated with pathological changes of the immune system. Multiparametric flow cytometry was used to assess markers of CD4(+) and CD8(+) T cell activation (CD38, HLA-DR), exhaustion (PD-1, Tim-3), senescence (CD28, CD57), and memory differentiation (CD45RO, CD27) in a cohort of 47 untreated HIV-infected individuals. Using bioinformatical methods, we identified 139 unique populations, representing the "combined T cell pathogenesis," which significantly differed between the HIV-infected individuals and healthy control subjects. CD38, HLA-DR, and PD-1 were particularly expressed within these unique T cell populations. The CD4/CD8 ratio was correlated with more pathological T cell populations (n = 10) and had a significantly higher average correlation coefficient than any other laboratory parameters. We also reduced the dimensionalities of the 139-unique populations by Z-transformations and principal component analysis, which still identified the CD4/CD8 ratio as the preeminent surrogate of combined T cell pathogenesis. Importantly, the CD4/CD8 ratio at baseline was shown to be significantly associated with CD4 recovery 2 y after therapy initiation. These results indicate that the CD4/CD8 ratio would be a suitable laboratory predictor in future clinical and therapeutic settings to monitor pathological T cell events in HIV infection.

Catenanes from catenanes: quantitative assessment of cooperativity in dynamic combinatorial catenation

A series of dynamic combinatorial [2] and [3]catenanes have been prepared. Formation of the [3]catenanes occurs with positive or negative cooperativity, depending on the cyclodextrin homologue. Systems level analysis allows cooperativity to be quantified and MD simulations reveal that cooperativity derives from the extents to which hydrophobic surface area is exposed to the aqueous surroundings.

Thrombin inhibitory activity of some polyphenolic compounds

Thrombin, also known as an active plasma coagulation factor II, belongs to the family of serine proteases and plays a crucial role in blood coagulation process. The process of thrombin generation is the central event of the hemostatic process and regulates blood coagulant activity. For this reason, thrombin inhibition is key to successful novel antithrombotic pharmacotherapy. The aim of our present study was to examine the effects of the well-known polyphenolic compounds on the activity of thrombin, by characterization of its interaction with selected polyphenols using different biochemical methods and biosensor BIAcore analyses. Only six compounds, cyanidin, quercetin, silybin, cyanin, (+)-catechin and (-)-epicatechin, of all examined in this study polyphenols caused the inhibition of thrombin amidolytic activity. But only three of the six compounds (cyanidin, quercetin and silybin) changed thrombin proteolytic activity. BIAcore analyses demonstrated that cyanidin and quercetin caused a strong response in the interaction with immobilized thrombin, while cyanin and (-)-epicatechin induced a low response. Lineweaver-Burk curves show that used polyphenol aglycones act as competitive thrombin inhibitors. Our results suggest that polyphenolic compounds might be potential structural bases and source to find and project nature-based, safe, orally bioavailable direct thrombin inhibitors.

Microbial translocation contribute to febrile episodes in adults with chemotherapy-induced neutropenia

In this study we sought to determine the contribution of microbial translocation to febrile episodes with no attributable microbiological cause (Fever of Unknown Origin, FUO) in an adult febrile neutropaenic cohort. Endotoxin concentrations were measured with the chromogenic Limulus Amoebocyte Assay and used as a direct measure of bacterial products whilst soluble CD14 (sCD14), measured with ELISA was selected as an indicator of the early host response to endotoxins. Endotoxin concentrations in this cohort were generally elevated but did not differ with the presentation of fever. Further stratification of the febrile episodes based on the microbiological findings revealed significantly (p = 0.0077) elevated endotoxin concentrations in FUO episodes compared with episodes with documented bacterial and viral findings. sCD14 concentrations were however, elevated in febrile episodes (p = 0.0066) and no association was observed between sCD14 concentration and microbiological findings. However, FUO episodes and episodes with Gram-negative bacteraemia were associated with higher median sCD14 concentrations than episodes with Gram-positive bacteraemia (p = 0.030). In conclusion, our findings suggest that in the absence of microbiological findings, microbial translocation could contribute to febrile episodes in an adult neutropaenic cohort. We further observed an association between prophylactic antibiotic use and increased plasma endotoxin concentrations (p = 0.0212).

Evaluation of etravirine resistance in clinical samples by a simple phenotypic test

Drug resistance testing is an important tool in the management of HIV-1 infection. As access to genotypic resistance assays is limited in low- and middle-income settings, alternatives are warranted. The aim of the study was to adapt a phenotypic drug susceptibility assay, ExaVir Drug, for detection of resistance to the second generation non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine (ETR). Five NNRTI resistant mutant forms of RT were produced (L100I, K103N, L100I/K103N, Y181C, V179D) in order to validate the assay for ETR. Furthermore, HIV-1 RT was purified from plasma samples (n = 28) obtained from treatment naïve and experienced HIV-1 infected patients, and ETR drug susceptibility (IC(50)) was estimated. The direct sequencing of the pol gene was performed. The recombinant RT mutants had the expected changes in drug sensitivity patterns. The RTs isolated from plasma of therapy naïve individuals showed low IC(50) for ETR. In the plasma virus from treatment experienced patients with Y181C, A98G, V108I, and/or K101E mutations in the pol gene, higher IC(50) values were found in line with reduced susceptibility data for ETR. This study demonstrates that ExaVir® Drug, a simple enzymatic phenotypic assay, can be used for detection of ETR resistance, including cross-resistance to other NNRTIs, in clinical samples. A further evaluation is needed to define clinical cut-offs; however the assay is an alternative to more costly HIV drug resistance tests, especially in low-income countries.

Kinetics of microbial translocation markers in patients on efavirenz or lopinavir/r based antiretroviral therapy

Objectives

We investigated whether there are differences in the effects on microbial translocation (MT) and enterocyte damage by different antiretroviral therapy (ART) regimens after 1.5 years and whether antibiotic use has impact on MT. In a randomized clinical trial (NCT01445223) on first line ART, patients started either lopinavir/r (LPV/r) (n = 34) or efavirenz (EFV) containing ART (n = 37). Lipopolysaccharide (LPS), sCD14, anti-flagellin antibodies and intestinal fatty acid binding protein (I-FABP) levels were determined in plasma at baseline (BL) and week 72 (w72).

Results

The levels of LPS and sCD14 were reduced from BL to w72 (157.5 pg/ml vs. 140.0 pg/ml, p = 0.0003; 3.13 ug/ml vs. 2.85 ug/ml, p = 0.005, respectively). The levels of anti-flagellin antibodies had decreased at w72 (0.35 vs 0.31 [OD]; p<0.0004), although significantly only in the LPV/r arm. I-FABP levels increased at w72 (2.26 ng/ml vs 3.13 ng/ml; p<0.0001), although significantly in EFV treated patients only. Patients given antibiotics at BL had lower sCD14 levels at w72 as revealed by ANCOVA compared to those who did not receive (Δ = −0.47 µg/ml; p = 0.015).

Conclusions

Markers of MT and enterocyte damage are elevated in untreated HIV-1 infected patients. Long-term ART reduces the levels, except for I-FABP which role as a marker of MT is questionable in ART-experienced patients. Why the enterocyte damage seems to persist remains to be established. Also antibiotic usage may influence the kinetics of the markers of MT.

Trial Registration

ClinicalTrials.gov NCT01445223