Dysregulation of secondary bile acid metabolism precedes islet autoimmunity and type 1 diabetes

The gut microbiota is crucial in the regulation of bile acid (BA) metabolism. However, not much is known about the regulation of BAs during progression to type 1 diabetes (T1D). Here, we analyzed serum and stool BAs in longitudinal samples collected at 3, 6, 12, 18, 24, and 36 months of age from children who developed a single islet autoantibody (AAb) (P1Ab; n = 23) or multiple islet AAbs (P2Ab; n = 13) and controls (CTRs; n = 38) who remained AAb negative. We also analyzed the stool microbiome in a subgroup of these children. Factor analysis showed that age had the strongest impact on both BA and microbiome profiles. We found that at an early age, systemic BAs and microbial secondary BA pathways were altered in the P2Ab group compared with the P1Ab and CTR groups. Our findings thus suggest that dysregulated BA metabolism in early life may contribute to the risk and pathogenesis of T1D.

Synthesis and biological evaluation of 4-hydroxy-methylpiperidinyl-N-benzyl-acylarylhydrazone hybrids designed as novel multifunctional drug candidates for Alzheimer's disease

The search for new drug candidates against Alzheimer's disease (AD) remains a complex challenge for medicinal chemists due to its multifactorial pathogenesis and incompletely understood physiopathology. In this context, we have explored the molecular hybridization of pharmacophore structural fragments from known bioactive molecules, aiming to obtain a novel molecular architecture in new chemical entities capable of concomitantly interacting with multiple targets in a so-called multi-target directed ligands (MTDLs) approach. This work describes the synthesis of 4-hydroxymethyl)piperidine-N-benzyl-acyl-hydrazone derivatives 5a-l, designed as novel MTDLs, showing improved multifunctional properties compared to the previously reported parent series of N-benzyl-(3-hydroxy)piperidine-acyl-hydrazone derivatives 4. The new improved derivatives were studied in silico, regarding their mode of interaction with AChE enzyme, and in vitro, for evaluation of their effects on the selective inhibition of cholinesterases, cellular antioxidant, and neuroprotective activities as their cytotoxicity in human neuroblastoma (SH-SY5Y) cells. Overall, compound PQM-181 (5 k) showed the best balanced selective and non-competitive inhibition of AChE (IC₅₀ = 5.9 μM, SI > 5.1), with an additional antioxidant activity (IC₅₀ = 7.45 µM) against neuronal t-BOOH-induced oxidative stress and neuroprotective ability against neurotoxicity elicited by both t-BOOH and OAβ_1-42, and a moderate ability to interfere in Aβ_1-42 aggregates, with low cytotoxicity and good predictive druggability properties, suggesting a multifunctional pharmacological profile suitable for further drug development against AD.

Pre-clinical evaluation of LASSBio-1491: From in vitro pharmacokinetic study to in vivo leishmanicidal activity

Leishmaniasis is a public health issue. It is among the top five parasitic illnesses worldwide and is one of the most neglected diseases. The current treatment disease includes limitations of toxicity, variable efficacy, high costs and inconvenient doses and treatment schedules. LASSBio-1736 was described as antileishmanial drug-candidate to cutaneous leishmaniasis, displaying plasma stability and with no preliminary signals of hepatic or renal toxicity. In this paper, we described the in vitro pharmacokinetic study of LASSBio-1491 (a less lipophilic isostere of LASSBio-1736) and it is in vitro and in vivo leishmanicidal activities. Our results demonstrated that LASSBio-1491 has high permeability, satisfactory aqueous solubility, long plasma and microsomal half-lives and low in vitro systemic clearance, suggesting a pharmacokinetic profile suitable for its use in a single daily dose. The antileishmanial effect of LASSBio-1491 was confirmed in vitro and in vivo. It exhibited no cytotoxic effect to mammalian cells and displayed good in –vivo effect against BALB/c mice infected with Leishmania major LV39 substrain, being 3 times more efficient than glucantime.

Neotropical mustelids: fecal metabolome diversity and its potential for taxonomic discrimination

Chemical profiles of non-invasive biological material, such as feces, have great potential to study elusive animals or those with low population densities. Here, we use a metabolomic approach to evaluate Neotropical mustelids as a biological model to describe the diversity of the metabolites present in fecal samples, as well as to evaluate the potential of chemical profiles for taxonomic discrimination. We collected fecal samples from captive individuals of five species of mustelids occurring in Brazil and analyzed them by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Over 200 compounds have been annotated; "bile acids, alcohols and derivatives" was the most expressive class in the metabolome of all the species. We successfully discriminated three taxonomic groups: 1 - Tayra (Eira barbara); 2 - otters (Lontra longicaudis and Pteronura brasiliensis; 1); and 3 - grisons (Galictis vittata and Galictis cuja). Several compounds seemed to be associated with food intake and the digestive process, while others were found for the first time in Neotropical mustelids. We concluded that mustelids show high metabolome diversity and that species-specific identification through metabolomic profiles is possible, thus contributing to the development and implementation of additional non-invasive approaches in the study of mustelids. This article is protected by copyright. All rights reserved.

Quantitative genome-scale metabolic modeling of human CD4+ T cell differentiation reveals subset-specific regulation of glycosphingolipid pathways

T cell activation, proliferation, and differentiation involve metabolic reprogramming resulting from the interplay of genes, proteins, and metabolites. Here, we aim to understand the metabolic pathways involved in the activation and functional differentiation of human CD4⁺ T cell subsets (T helper [Th]1, Th2, Th17, and induced regulatory T [iTreg] cells). Here, we combine genome-scale metabolic modeling, gene expression data, and targeted and non-targeted lipidomics experiments, together with in vitro gene knockdown experiments, and show that human CD4⁺ T cells undergo specific metabolic changes during activation and functional differentiation. In addition, we confirm the importance of ceramide and glycosphingolipid biosynthesis pathways in Th17 differentiation and effector functions. Through in vitro gene knockdown experiments, we substantiate the requirement of serine palmitoyltransferase (SPT), a de novo sphingolipid pathway in the expression of proinflammatory cytokines (interleukin [IL]-17A and IL17F) by Th17 cells. Our findings provide a comprehensive resource for selective manipulation of CD4⁺ T cells under disease conditions characterized by an imbalance of Th17/natural Treg (nTreg) cells.

Linking Gut Microbiome and Lipid Metabolism: Moving beyond Associations

Various studies aiming to elucidate the role of the gut microbiome-metabolome co-axis in health and disease have primarily focused on water-soluble polar metabolites, whilst non-polar microbial lipids have received less attention. The concept of microbiota-dependent lipid biotransformation is over a century old. However, only recently, several studies have shown how microbial lipids alter intestinal and circulating lipid concentrations in the host, thus impacting human lipid homeostasis. There is emerging evidence that gut microbial communities play a particularly significant role in the regulation of host cholesterol and sphingolipid homeostasis. Here, we review and discuss recent research focusing on microbe-host-lipid co-metabolism. We also discuss the interplay of human gut microbiota and molecular lipids entering host systemic circulation, and its role in health and disease.

Systems biology approaches to study lipidomes in health and disease

Lipids have many important biological roles, such as energy storage sources, structural components of plasma membranes and as intermediates in metabolic and signaling pathways. Lipid metabolism is under tight homeostatic control, exhibiting spatial and dynamic complexity at multiple levels. Consequently, lipid-related disturbances play important roles in the pathogenesis of most of the common diseases. Lipidomics, defined as the study of lipidomes in biological systems, has emerged as a rapidly-growing field. Due to the chemical and functional diversity of lipids, the application of a systems biology approach is essential if one is to address lipid functionality at different physiological levels. In parallel with analytical advances to measure lipids in biological matrices, the field of computational lipidomics has been rapidly advancing, enabling modeling of lipidomes in their pathway, spatial and dynamic contexts. This review focuses on recent progress in systems biology approaches to study lipids in health and disease, with specific emphasis on methodological advances and biomedical applications.

New Leishmania donovani nucleoside hydrolase inhibitors from Brazilian flora

This study presents new inhibitors of the nucleoside hydrolase from Leishmania donovani (LdNH) with in vitro leishmanicidal activity. Biological screening of 214 Brazilian plant extracts was performed to select plants with enzyme inhibitory activity. Two plants were selected for their results, and for their lack of prior phytochemical description: Leandra amplexicaulis DC. (Melastomataceae) and Urvillea rufescens Cambess (Sapindaceae). Three flavonoids were isolated by bioguided fractionation of the hydroethanolic extracts: kaempferol 3-O-α-l-rhamnopyranoside (1) and kaempferol 3-O-β-d-xylopyranosyl-(1→2)-α-l-rhamnopyranoside (2) from L. amplexicaulis, as well as tricetin-4′-O-methyl flavone (3) from U. rufescens. These flavonoids showed inhibitory activities (IC₅₀) of 197.4 μM (1), 74.7 μM (2) and 1.1 μM (3) on the LdNH. Their binding mode was proposed based on molecular docking with LdNH and by NMR Saturation Transfer Difference studies. Kinetic studies demonstrate that the most potent inhibitor (3) acts by uncompetitive inhibition. This study reports for the first time the inhibition of LdNH by naturally sourced flavonoids.

This study presents flavonoids as new inhibitors of the nucleoside hydrolase from Leishmania donovani (LdNH) and the first uncompetitive inhibitor described for LdNH.

Theoretical and experimental characterization of 1,4-N⋯S σ-hole intramolecular interactions in bioactive N-acylhydrazone derivatives

Sigma-hole (σ-hole) bonds are interactions that are gaining special attention in medicinal chemistry.

Microfluidic converging/diverging channels optimised for homogeneous extensional deformation

In this work, we optimise microfluidic converging/diverging geometries in order to produce constant strain-rates along the centreline of the flow, for performing studies under homogeneous extension. The design is examined for both two-dimensional and three-dimensional flows where the effects of aspect ratio and dimensionless contraction length are investigated. Initially, pressure driven flows of Newtonian fluids under creeping flow conditions are considered, which is a reasonable approximation in microfluidics, and the limits of the applicability of the design in terms of Reynolds numbers are investigated. The optimised geometry is then used for studying the flow of viscoelastic fluids and the practical limitations in terms of Weissenberg number are reported. Furthermore, the optimisation strategy is also applied for electro-osmotic driven flows, where the development of a plug-like velocity profile allows for a wider region of homogeneous extensional deformation in the flow field.

Purely elastic flow instabilities in microscale cross-slot devices

We present an experimental investigation of viscoelastic fluid flow in a cross-slot microgeometry under low Reynolds number flow conditions. By using several viscoelastic fluids, we investigate the effects of the microchannel bounding walls and the polymer solution concentration on the flow patterns. We demonstrate that for concentrated polymer solutions, the flow undergoes a bifurcation above a critical Weissenberg number (Wi) at which the flow becomes asymmetric but remains steady. The appearance of this elastic instability depends on the channel aspect ratio, defined as the ratio between the depth and the width of the channels. At high aspect ratios, when bounding wall effects are reduced, two types of elastic instabilities were observed, one in which the flow becomes asymmetric and steady, followed by a second instability at higher Wi, in which the flow becomes time-dependent. When the aspect ratio decreases, the bounding walls have a stabilizing effect, preventing the occurrence of steady asymmetric flow and postponing the transition to unsteady flow to higher Wi. For less concentrated solutions, the first elastic instability to steady asymmetric flow is absent and only the time-dependent flow instability is observed.

Simple HPLC-UV for the quantification of a new leishmanicidal candidate (E)-1-4(trifluoromethyl) benzylidene)-5-(2-4-dichlorozoyl) carbonylhydrazine (LASSBio-1736) in rat plasma for pharmacokinetics assessment

In this study, a sensitive HPLC-UV assay was developed and validated for the determination of LASSBio-1736 in rat plasma with sodium diclofenac as internal standard (IS). Liquid-liquid extraction using acetonitrile was employed to extract LASSBio-1736 and IS from 100 μL of plasma previously basified with NaOH 0.1 M. Chromatographic separation was carried on Waters Spherisorb(®) S5 ODS2 C18 column (150 × 4.6 mm, 5 μm) using an isocratic mobile phase composed by water with triethylamine 0.3% (pH 4), methanol and acetonitrile grade (45:15:40, v/v/v) at a flow rate of 1 mL/min. Both LASSBio-1736 and IS were eluted at 4.2 and 5 min, respectively, with a total run time of 8 min only. The lower limit of quantification was 0.2 μg/mL and linearity between 0.2 and 4 μg/mL was obtained, with an R(2)  > 0.99. The accuracy of the method was >90.5%. The relative standard deviations intra and interday were <6.19 and <7.83%, respectively. The method showed the sensitivity, linearity, precision, accuracy and selectivity required to quantify LASSBio-1736 in preclinical pharmacokinetic studies according to the criteria established by the US Food and Drug Administration and European Medicines Agency. Copyright © 2016 John Wiley & Sons, Ltd.

3-Aminothiophene-2-acylhydrazones: non-toxic, analgesic and anti-inflammatory lead-candidates

Different chemotypes are described as anti-inflammatory. Among them the N-acylhydrazones (NAH) are highlighted by their privileged structure nature, being present in several anti-inflammatory drug-candidates. In this paper a series of functionalized 3-aminothiophene-2-acylhydrazone derivatives 5a-i were designed, synthesized and bioassayed. These new derivatives showed great anti-inflammatory and analgesic potency and efficacy. Compounds 5a and 5d stand out in this respect, and were also active in CFA-induced arthritis in rats. After daily treatment for seven days with 5a and 5d (50 µmol/Kg), by oral administration, these compounds were not renal or hepatotoxic nor immunosuppressive. Compounds 5a and 5d also displayed good drug-scores and low risk toxicity calculated in silico using the program OSIRIS Property Explorer.

Extensional flow of hyaluronic acid solutions in an optimized microfluidic cross-slot device

We utilize a recently developed microfluidic device, the Optimized Shape Cross-slot Extensional Rheometer (OSCER), to study the elongational flow behavior and rheological properties of hyaluronic acid (HA) solutions representative of the synovial fluid (SF) found in the knee joint. The OSCER geometry is a stagnation point device that imposes a planar extensional flow with a homogenous extension rate over a significant length of the inlet and outlet channel axes. Due to the compressive nature of the flow generated along the inlet channels, and the planar elongational flow along the outlet channels, the flow field in the OSCER device can also be considered as representative of the flow field that arises between compressing articular cartilage layers of the knee joints during running or jumping movements. Full-field birefringence microscopy measurements demonstrate a high degree of localized macromolecular orientation along streamlines passing close to the stagnation point of the OSCER device, while micro-particle image velocimetry is used to quantify the flow kinematics. The stress-optical rule is used to assess the local extensional viscosity in the elongating fluid elements as a function of the measured deformation rate. The large limiting values of the dimensionless Trouton ratio, Tr ∼ O(50), demonstrate that these fluids are highly extensional-thickening, providing a clear mechanism for the load-dampening properties of SF. The results also indicate the potential for utilizing the OSCER in screening of physiological SF samples, which will lead to improved understanding of, and therapies for, disease progression in arthritis sufferers.

Experimental characterisation of a novel viscoelastic rectifier design

A planar microfluidic system with contractions and obstacles is characterized in terms of anisotropic flow resistance due to viscoelastic effects. The working mechanism is illustrated using streak photography, while the diodicity performance is quantified by pressure drop measurements. The point of maximum performance is found to occur at relatively low elasticity levels, with diodicity around 3.5. Based on a previously published numerical work [Ejlebjerg et al., Appl. Phys. Lett. 100, 234102 (2012)], 2D simulations of the FENE-CR differential constitutive model are also presented, but limited reproducibility and uncertainties of the experimental data prevent a direct comparison at low elasticity, where the flow is essentially two-dimensional.

Extensional flow of blood analog solutions in microfluidic devices

In this study, we show the importance of extensional rheology, in addition to the shear rheology, in the choice of blood analog solutions intended to be used in vitro for mimicking the microcirculatory system. For this purpose, we compare the flow of a Newtonian fluid and two well-established viscoelastic blood analog polymer solutions through microfluidic channels containing both hyperbolic and abrupt contractions∕expansions. The hyperbolic shape was selected in order to impose a nearly constant strain rate at the centerline of the microchannels and achieve a quasihomogeneous and strong extensional flow often found in features of the human microcirculatory system such as stenoses. The two blood analog fluids used are aqueous solutions of a polyacrylamide (125 ppm w∕w) and of a xanthan gum (500 ppm w∕w), which were characterized rheologically in steady-shear flow using a rotational rheometer and in extension using a capillary breakup extensional rheometer (CaBER). Both blood analogs exhibit a shear-thinning behavior similar to that of whole human blood, but their relaxation times, obtained from CaBER experiments, are substantially different (by one order of magnitude). Visualizations of the flow patterns using streak photography, measurements of the velocity field using microparticle image velocimetry, and pressure-drop measurements were carried out experimentally for a wide range of flow rates. The experimental results were also compared with the numerical simulations of the flow of a Newtonian fluid and a generalized Newtonian fluid with shear-thinning behavior. Our results show that the flow patterns of the two blood analog solutions are considerably different, despite their similar shear rheology. Furthermore, we demonstrate that the elastic properties of the fluid have a major impact on the flow characteristics, with the polyacrylamide solution exhibiting a much stronger elastic character. As such, these properties must be taken into account in the choice or development of analog fluids that are adequate to replicate blood behavior at the microscale.

Purely elastic flow asymmetries

Using a numerical technique we demonstrate that the flow of the simplest differential viscoelastic fluid model (i.e., the upper-convected Maxwell model) goes through a bifurcation to a steady asymmetric state when flowing in a perfectly symmetric "cross-slot" geometry. We show that this asymmetry is purely elastic in nature and that the effect of inertia is a stabilizing one. Our results are in qualitative agreement with very recent experimental visualizations of a similar flow in the microfluidic apparatus of Arratia et al.

The Drosophila serido speciation puzzle: putting new pieces together

The D. serido superspecies is a complex mosaic of populations distributed over a vast part of South America and showing various degrees of genetical divergence. We have analyzed its chromosomal constitution in 16 new localities of southeastern and southern Brazil. Both the metaphase and salivary gland chromosomes show a sharp split of these populations in two groups. Four populations, fixed for inversion 2e8 and showing the type I karyotype, represent the southwestern limit of D. serido type B, which inhabits the Cerrado in central-western Brazil. The remaining populations are homozygous for 2x7, an inversion also fixed in the Caatinga populations of northeastern Brazil. However, their karyotype, in those populations analyzed, belong to a different type (V) from that of the Caatinga populations. Populations in this second group are polymorphic for five inversions on chromosome 2 plus another on chromosome 5 and show considerable interpopulation differentiation. The breakpoints of chromosome 2 inversions are described and the inversion loops of several heterokaryotypes are presented. Biogeographical information suggests that there are clear ecological differences between the two groups of populations as well as among the populations within the second group. Thepossible role of host plants in promoting the genetic divergence among the D. serido populations is discussed.

Diffractive structures holographically recorded in amorphous hydrogenated carbon (a-C:H) films

We propose and demonstrate the direct recording of submicrometer relief gratings in amorphous hydrogenated carbon (a -C:H) films by reactive ion etching (RIE) for use as diffractive optical components. The high refractive index of this film and its transparency in the IR make such structures promising candidates for IR-transmission diffractive optical components. The structures are holographically recorded in photoresist and then transferred to a thin aluminum layer that is used as a mask for RIE of the a -C:H films. The diffraction measurements of the structures recorded in these films demonstrated the feasibility of using the materials as diffractive optical components.

Breast reduction: shortening scars with liposuction

The authors describe a mammaplasty reduction technique they believe is safe due to modern cutaneous resection and adequate areolar nourishment. It is made possible by maintaining a large pedicule which is also versatile since it can be used on all kinds of breasts. Good results can be reproduced by other surgeons.

Respiratory assistance with a non-invasive ventilator (Bipap) in MND/ALS patients: survival rates in a controlled trial

Noninvasive ventilatory assistance, in ALS patients, with the bilevel intermittent positive air pressure (Bipap) was studied, in a prospective and controlled trial, by the authors. Twenty ALS bulbar patients, fulfilling El Escorial criteria for probable or definite disease, were selected. For the follow-up all patients were submitted to evaluation with the Norris scale, modified Barthel score and an analog scale of life satisfaction, every 3 months. All patients were also submitted to respiratory functional testing (RFT). Ten of these patients were treated with palliative management (group I), the remaining ten patients received Bipap support (group II). Clinical evolution curves and clinical parameters were not statistically different in both groups, except for the percentage of actual predicted value of vital capacity (p < 0.03), showing a more advanced disease in group II patients. Analog scale of life satisfaction showed improvement in the group II, even after the beginning of respiratory insufficiency, though without significance probably due to the small sample size (p < 0.1). Since 6 patients in group II are still alive survival rates were compared with log rank test considering cumulative survivals with Kaplan-Meier estimates. Total survival and survival from diurnal abnormalities in gas exchange (survival 1) were significantly longer for group II (p < 0.006 and p < 0.0004, respectively). In spite of the small number of patients, preliminary results strongly support the importance of BIPAP in ALS patients, though further studies must go on in order to optimize the best time for introducing Bipap.

[Nephrotic syndrome caused by membranous glomerulonephritis associated with chronic myeloid leukemia]

A patient developed nephrotic syndrome four years after diagnosed chronic myelogenous leukemia. Renal histology showed characteristic changes of membranous glomerulopathy. To our knowledge, this is the first reported case of membranous glomerulopathy associated with chronic myelogenous leukemia.

Characterization of circulating immune complexes detected by monoclonal rheumatoid factor and conglutinin radioimmunoassays in SLE nephritis

By utilizing a monoclonal rheumatoid factor (mRF) and bovine conglutinin (K) in radioimmunoassays, ICs detected in sera of patients with lupus nephritis were partially characterized. The mRF-RIA detected high levels of ICs in 86.9% of patients with active SLE and in only 22.7% of patients with inactive disease. Positive association was observed with clinical scores and significant negative correlation was found with serum levels of C1q, C3 and C4. The mRF-reactive ICs were shown to be cryoprecipitable and analysis by gel filtration through Sephacryl S-300 disclosed a material eluting between IgM and IgG, being dissociated in acidic pH. On the other hand, no association could be demonstrated between levels of ICs detected by K-RIA and clinical activity. Positivity in this assay was only 8.7% and 31.8% for active and inactive groups. Differently from the ICs detected by mRF-RIA, the K-reactive material was not precipitated by 3.5% PEG, nor by centrifugation in the cold, and EDTA did not reduce the binding of IgG to K in positive sera. The reactive IgG in Sephacryl S-300 chromatography eluted in the same position as monomeric IgG both in neutral and dissociating conditions. No C3 could be detected in ICs reactive in both assays.

Gastrointestinal involvement in neurofibromatosis: angiographic presentation

A large neurofibroma associated with gastrointestinal hemorrhage was demonstrated by visceral arteriography. The findings are correlated with those of resected pathologic specimen.

Treatment of portal vein obstruction by percutaneous transhepatic angioplasty

A case of extrahepatic portal hypertension and gastric variceal bleeding due to portal vein occlusion, most probably secondary to chronic pancreatitis, was treated by percutaneous transhepatic angioplasty. After the portal angioplasty there was marked clinical improvement, with control of the variceal bleeding and significant reduction of the pressure gradient within the portal system.

Development of DNA puffs and patterns of polypeptide synthesis in the salivary glands of Bradysia hygida

In the three salivary gland regions of Bradysia hygida (Diptera, Sciaridae) the patterns of polypeptide synthesis, as revealed by electrophoresis and fluorography, are very stable during the fourth larval instar until about 30 h before the pupal molt. At this age the patterns of polypeptide synthesis start to undergo marked changes. The striking correlations between these changes and the development of two distinct groups of DNA puffs support the proposal that DNA puffs are causally related to the synthesis of specific proteins in the salivary glands.