The ring-stage of Plasmodium falciparum observed in RBCs of hospitalized malaria patients

Raman spectra of the blood samples obtained directly from hospitalized malaria patients with Plasmodium falciparum (P. falciparum) in the ring-stage were analyzed. Changes observed in the Raman band intensities of the infected patients compared to healthy volunteers are the result of parasite activity inside red blood cells. The obtained spectra were discussed by analyzing differences in particular spectral regions by evaluating changes in the band intensity ratios as well as using PCA analysis. The alterations of erythrocyte membranes caused by parasite penetration are visible by a reduced I1130/I1075 intensity ratio expressing the lowering of the amount of domains arranged in trans conformation. The I2930/I2850 ratio, which is a measure of modifications in structures of membrane proteins and lipids, in infected red blood cells increases, which is caused by malaria protein export to the erythrocyte membrane and expresses the membrane disarrangement. In the pyrrole ring vibration region, the ν4 band marker of the oxygenated-Hb shows at 1371 cm(-1) whereas the ν4 band at 1353 cm(-1) related to the deoxygenated-Hb is observed for malaria patients and is characterized by a higher intensity in infected erythrocytes. The amide I analysis shows the modifications in the secondary structure composition in the infected RBCs. We found that the P. falciparum infection leads to a decrease in the α-helical content and a concurrent increase in undefined (random-coil) structures. It was observed that the Raman spectra changes are also the result of the hemozoin formation process. In the pyrrole ring stretching vibration region, the increase of 1220 cm(-1) (deoxyHb) as against 1248 cm(-1) (oxyHb) may be considered as a signal of hemozoin formation in the RBCs. Relatively intense band patterns at 1560 cm(-1) and also at 1570 cm(-1) and 1552 cm(-1) may be due to the hemozoin that is formed according to parasite activity. The results of medical diagnostic tests had not presented changes in patient RBC parameters. A significant reduction in WBC count was noticed along with a decrease in neutrophil and platelet count when compared with the control group. Although no change is observed in the overall picture of the erythrocytes, pathological changes are evident in the Raman spectrum.

Template-Triggered Emergence of a Self-Replicator from a Dynamic Combinatorial Library

Self-assembly of a specific member of a dynamic combinatorial library (DCL) may lead to self-replication of this molecule. However, if the concentration of the potential replicator in the DCL fails to exceed its critical aggregation concentration (CAC), then self-replication will not occur. We now show how addition of a template can raise the concentration of a library member-template complex beyond its CAC, leading to the onset of self-replication. Once in existence, the replicator aggregates promote further replication also in the absence of the template that induced the initial emergence of the replicator.

Effects of Co-Trimoxazole on Microbial Translocation in HIV-1-Infected Patients Initiating Antiretroviral Therapy

Microbial translocation (MT) contributes to immune activation during HIV-1 infection, and persists after initiation of antiretroviral therapy (ART). We investigated whether levels of MT markers are influenced by the use of co-trimoxazole (TMP-SMX) in HIV-1 patients. Plasma samples were obtained from HIV-1-infected patients initiating ART with (n=13) or without (n=13) TMP-SMX prophylaxis. Markers of MT [lipopolysaccharide-binding protein (LBP), lipopolysaccharide (LPS), soluble CD14 (sCD14), and intestinal fatty acid binding protein (I-FABP)] were assessed at baseline (BL), at 1 month, and at 1 year by the Limulus Amebocyte Lysate Assay or ELISA. BL levels of LBP were elevated in both categories of patients; they were highest in patients starting ART and TMP-SMX (median, μg/ml: 36.7 vs. 4.3, respectively, p=0.001) and correlated inversely with CD4(+) T cell counts (ρ=-0.65; p=0.005). Patients receiving ART and TMP-SMX had a significant reduction in LBP between BL and 1 year (median, μg/ml: 36.7 vs. 11.1; p=0.003). In contrast, levels of LPS at BL were lower in patients starting ART and TMP-SMX compared to those without TMP-SMX (median, pg/ml: 221 vs. 303 respectively; p=0.002) and did not change at 1 year. The increased BL levels of sCD14 had declined in both groups at 1 year. No difference in I-FABP levels was found between BL and 1 year. Concomitant use of ART and TMP-SMX reduces microbial translocation markers LBP and sCD14, probably due to its impact on the gut microbiota. Effective ART for 1 year does not restore gut-blood barrier dysfunction.

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.