Vaginal prevention of Candida albicans: synergistic effect of lactobacilli and mannan oligosaccharides (MOS)

Vulvovaginal candidiasis (VVC) affects approximately 30-50% of women at least once during their lifetime, causing uncomfortable symptoms and limitations in their daily quality of life. Antifungal therapy is not very effective, does not prevent recurrencies and usually causes side effects. Therefore, alternative therapies are urgently needed. The goal of this work was to investigate the potential benefits of using mannan oligosaccharides (MOS) extracts together with a Lactobacillus sp. pool, composed by the most significant species present in the vaginal environment, to prevent infections by Candida albicans. Microbial growth of isolated strains of the main vaginal lactobacilli and Candida strains was assessed in the presence of MOS, to screen their impact upon growth. A pool of the lactobacilli was then tested against C. albicans in competition and prophylaxis studies; bacterial and yeast cell numbers were quantified in specific time points, and the above-mentioned studies were assessed in simulated vaginal fluid (SVF). Finally, adhesion to vaginal epithelial cells (HeLa) was also evaluated, once again resorting to simultaneous exposure (competition) or prophylaxis assays, aiming to measure the effect of MOS presence in pathogen adherence. Results demonstrated that MOS extracts have potential to prevent vaginal candidiasis in synergy with vaginal lactobacilli, with improved results than those obtained when using lactobacilli alone. KEY POINTS: Potential benefits of MOS extracts with vaginal lactobacilli to prevent C. albicans infections. MOS impacts on growth of vaginal lactobacilli pool and C. albicans in SVF. MOS extracts in synergy with L. crispatus inhibit C. albicans adhesion in HeLa cells.

Circular economyeast: Saccharomyces cerevisiae as a sustainable source of glucans and its safety for skincare application

Glucans, a polysaccharide naturally present in the yeast cell wall that can be obtained from side streams generated during the fermentation process, have gained increasing attention for their potential as a skin ingredient. Therefore, this study focused on the extraction method to isolate and purify water-insoluble glucans from two different Saccharomyces cerevisiae strains: an engineered strain obtained from spent yeast in an industrial fermentation process and a wild strain produced through lab-scale fermentation. Two water-insoluble extracts with a high glucose content (> 90 %) were achieved and further subjected to a chemical modification using carboxymethylation to improve their water solubility. All the glucans' extracts, water-insoluble and carboxymethylated, were structurally and chemically characterized, showing almost no differences between both yeast-type strains. To ensure their safety for skin application, a broad safety assessment was undertaken, and no cytotoxic effect, immunomodulatory capacity (IL-6 and IL-8 regulation), genotoxicity, skin sensitization, and impact on the skin microbiota were observed. These findings highlight the potential of glucans derived from spent yeast as a sustainable and safe ingredient for cosmetic and skincare formulations, contributing to the sustainability and circular economy.

Structure and properties of Quercus robur acorn starch extracted by pulsed electric field technology

Pulsed electric field (PEF) technology was used to extract starch from Q. robur flours using low-intensity electric fields (0 and 0.1 kV/cm) and study the impact of PEF on the structure and properties of acorn starch concerning commercial starch. PEF technology is an advantageous method for starch extraction than the aqueous steeping from an industrial perspective since reduces extraction time and allows for continuous processing of larger suspension volumes. PEF technology preserved the amylose and amylopectin contents, hydrogen bonds, and diffraction patterns, as well as the starch native properties. Hence, PEF could be used to obtain native starches, but future studies should verify its economic viability. Acorn starches have lower damaged starch content, gelatinization temperatures, enthalpies, improved pseudoplastic behavior, reduced in-vitro digestibility, and lower resistance to deformation compared to commercial corn starch. The higher solubility and swelling power of acorn starches up to 80 °C make them a suitable food additive in fermented yogurt and milk products and thus help to value acorn and acorn starches. Hence, acorns can be used to obtain native starches, a food ingredient with a wide range of food and non-food usage, using PEF.

Harvesting the Power of Green Synthesis: Gold Nanoparticles Tailored for Prostate Cancer Therapy

Biosynthetic gold nanoparticles (bAuNPs) present a promising avenue for enhancing bio-compatibility and offering an economically and environmentally responsible alternative to traditional production methods, achieved through a reduction in the use of hazardous chemicals. While the potential of bAuNPs as anticancer agents has been explored, there is a limited body of research focusing on the crucial physicochemical conditions influencing bAuNP production. In this study, we aim to identify the optimal growth phase of Pseudomonas aeruginosa cultures that maximizes the redox potential and coordinates the formation of bAuNPs with increased efficiency. The investigation employs 2,6-dichlorophenolindophenol (DCIP) as a redox indicator. Simultaneously, we explore the impact of temperature, pH, and incubation duration on the biosynthesis of bAuNPs, with a specific emphasis on their potential application as antitumor agents. Characterization of the resulting bAuNPs is conducted using ATR-FT-IR, TEM, and UV-Vis spectroscopy. To gain insights into the anticancer potential of bAuNPs, an experimental model is employed, utilizing both non-neoplastic (HPEpiC) and neoplastic (PC3) epithelial cell lines. Notably, P. aeruginosa cultures at 9 h/OD600 = 1, combined with biosynthesis at pH 9.0 for 24 h at 58 °C, produce bAuNPs that exhibit smaller, more spherical, and less aggregated characteristics. Crucially, these nanoparticles demonstrate negligible effects on HPEpiC cells while significantly impacting PC3 cells, resulting in reduced viability, migration, and lower IL-6 levels. This research lays the groundwork for the development of more specialized, economical, and ecologically friendly treatment modalities.

Biological Potential and Bioaccessibility of Encapsulated Curcumin into Cetyltrimethylammonium Bromide Modified Cellulose Nanocrystals

Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.

Modification of Acorn Starch Structure and Properties by High Hydrostatic Pressure

Despite being rich in starch, over half of acorn production is undervalued. High hydrostatic pressure was used to modify the properties of Q. pyrenaica (0.1 and 460 MPa for 20 min) and Q. robur (0.1 and 333 MPa for 17.4 min) acorn starches to obtain high-valued ingredients. Pressure significantly altered the span distribution and heterogeneity of the acorn starch granules depending on the species, but their morphology was unaffected. Pressurization increased the amylose/amylopectin ratio and damaged starch contents, but the effect was more prominent in Q. pyrenaica than in Q. robur. However, the polymorphism, relative crystallinity, gelatinization temperatures, and enthalpies were preserved. The pressure effect on the starch properties depended on the property and species. The solubility, swelling power, and acorn gels' resistance towards deformation for both species decreased after pressurization. For Q. pyrenaica starch, the in vitro digestibility increased, but the pseudoplastic behavior decreased after pressurization. No differences were seen for Q. robur. Regarding the commercial starch, acorn starches had lower gelatinization temperatures and enthalpies, lower in vitro digestibility, lower resistance towards deformation, superior pseudoplastic behavior, and overall higher solubility and swelling power until 80 °C. This encourages the usage of acorn starches as a new food ingredient.

Effect of drying technology in Saccharomyces cerevisiae mannans: Structural, physicochemical, and functional properties

Mannans are polysaccharides whose physicochemical and biological properties render them commercialization in several products. Since these properties are strongly dependent on production conditions, the present study aims to assess the impact of different drying technologies - freeze (FDM) and spray drying (SDM) - on the structural, physicochemical, and biological properties of mannans from Saccharomyces cerevisiae. Structural analysis was assessed by FT-IR, PXRD and SEM, whereas physicochemical properties were evaluated based on sugars, protein, ash and water contents, solubility, and molecular weight distribution. Thermal behaviour was analysed by DSC, and antioxidant activity by DPPH and ABTS assays. The parameters which revealed major differences, in terms of structural and physicochemical properties regarded morphology (SEM), physical appearance (colour), moisture (3.6 ± 0.1 % and 11.9 ± 0.6 % for FDM and SDM, respectively) and solubility (1 mg/mL for FDM and 25 mg/mL for SDM). Nevertheless, these differences were not translated into the antioxidant capacity.

Effect of Mannan Oligosaccharides Extracts in Uropathogenic Escherichia coli Adhesion in Human Bladder Cells

Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.

Carboxymethyl Cellulose as a Food Emulsifier: Are Its Days Numbered?

Carboxymethyl cellulose use in industry is ubiquitous. Though it is recognized as safe by the EFSA and FDA, newer works have raised concerns related to its safety, as in vivo studies showed evidence of gut dysbiosis associated with CMC's presence. Herein lies the question, is CMC a gut pro-inflammatory compound? As no work addressed this question, we sought to understand whether CMC was pro-inflammatory through the immunomodulation of GI tract epithelial cells. The results showed that while CMC was not cytotoxic up to 25 mg/mL towards Caco-2, HT29-MTX and Hep G2 cells, it had an overall pro-inflammatory behavior. In a Caco-2 monolayer, CMC by itself increased IL-6, IL-8 and TNF-α secretion, with the latter increasing by 1924%, and with these increases being 9.7 times superior to the one obtained for the IL-1β pro-inflammation control. In co-culture models, an increase in secretion in the apical side, particularly for IL-6 (692% increase), was observed, and when RAW 264.7 was added, data showed a more complex scenario as stimulation of pro-inflammatory (IL-6, MCP-1 and TNF-α) and anti-inflammatory (IL-10 and IFN-β) cytokines in the basal side was observed. Considering these results, CMC may exert a pro-inflammatory effect in the intestinal lumen, and despite more studies being required, the incorporation of CMC in foodstuffs must be carefully considered in the future to minimize potential GI tract dysbiosis.

Spent Yeast Waste Streams as a Sustainable Source of Bioactive Peptides for Skin Applications

Spent yeast waste streams are a byproduct obtained from fermentation process and have been shown to be a rich secondary source of bioactive compounds such as phenolic compounds and peptides. The latter are of particular interest for skin care and cosmetics as they have been shown to be safe and hypoallergenic while simultaneously being able to exert various effects upon the epidermis modulating immune response and targeting skin metabolites, such as collagen production. As the potential of spent yeast's peptides has been mainly explored for food-related applications, this work sought to understand if peptide fractions previously extracted from fermentation engineered spent yeast (Saccharomyces cerevisiae) waste streams possess biological potential for skin-related applications. To that end, cytotoxic effects on HaCat and HDFa cells and whether they were capable of exerting a positive effect upon the production of skin metabolites relevant for skin health, such as collagen, hyaluronic acid, fibronectin and elastin, were evaluated. The results showed that the peptide fractions assayed were not cytotoxic up to the highest concentration tested (500 µg/mL) for both cell lines tested. Furthermore, all peptide fractions showed a capacity to modulate the various target metabolites production with an overall positive effect being observed for the four fractions over the six selected targets (pro-collagen IαI, hyaluronic acid, fibronectin, cytokeratin-14, elastin, and aquaporin-9). Concerning the evaluated fractions, the overall best performance (Gpep > 1 kDa) was of an average promotion of 41.25% over the six metabolites and two cell lines assessed at a concentration of 100 µg/mL. These results showed that the peptide fractions assayed in this work have potential for future applications in skin-related products at relatively low concentrations, thus providing an alternative solution for one of the fermentation industry's waste streams and creating a novel and highly valuable bioactive ingredient with encompassing activity to be applied in future skin care formulations.

Valorization of Sugarcane By-Products through Synthesis of Biogenic Amorphous Silica Microspheres for Sustainable Cosmetics

Ashes from sugarcane by-product incineration were used to synthesize silica powders through alkaline hot extraction, followed by ethanol/acid precipitation or the sol-gel method. Both production methods allowed amorphous spherical silica microparticles with sizes ranging from 1-15 μm and 97% purity to be obtained. Water absorption ranged from 135-155 mL/100 g and 150-250 mL/100 g for precipitated silica and silica gel, respectively, while oil absorption ranged from 305 to 390 and from 250 to 350 mL/100 g. The precipitation with ethanol allowed the recovery of 178 g silica/kg ash, with a lab process cost of EUR 28.95/kg, while the sol-gel process showed a yield of 198 g silica/kg ash with a cost of EUR 10.89/kg. The experimental data suggest that ash from sugarcane by-products is a promising source to be converted into a competitive value-added product, minimizing the environmental impact of disposal problems.

Comparative Analysis of Mannans Extraction Processes from Spent Yeast Saccharomyces cerevisiae

Mannans are outstanding polysaccharides that have gained exponential interest over the years. These polysaccharides may be extracted from the cell wall of Saccharomyces cerevisiae, and recovered from the brewing or synthetic biology industries, among others. In this work, several extraction processes-physical, chemical and enzymatic-were studied, all aiming to obtain mannans from spent yeast S. cerevisiae. Their performance was evaluated in terms of yield, mannose content and cost. The resultant extracts were characterized in terms of their structure (FT-IR, PXRD and SEM), physicochemical properties (color, molecular weight distribution, sugars, protein, ash and water content) and thermal stability (DSC). The biological properties were assessed through the screening of prebiotic activity in Lactobacillus plantarum and Bifidobacterium animalis. The highest yield (58.82%) was achieved by using an alkaline thermal process, though the correspondent mannose content was low. The extract obtained by autolysis followed by a hydrothermal step resulted in the highest mannose content (59.19%). On the other hand, the extract obtained through the enzymatic hydrolysis displayed the highest prebiotic activity. This comparative study is expected to lay the scientific foundation for the obtention of well-characterized mannans from yeast, which will pave the way for their application in various fields.

Protective role of Portuguese natural mineral waters on skin aging: in vitro evaluation of anti-senescence and anti-oxidant properties

Natural mineral waters (NMWs) emerge from the earth as springs and their beneficial therapeutic effect has been empirically recognized in different countries. Portugal has diverse NMW resources that are sought for the relief of different afflictions including dermatological complications. However, there is a lack of scientific validation supporting this empiric knowledge. In this study, we aimed to screen the in vitro bioactivity of Portuguese NMWs with different chemical profiles, namely sulfurous/bicarbonate/sodic (SBS), bicarbonate/magnesium, sulfated/calcic, sulfurous/chlorinated/sodic, sulfurous/bicarbonate/fluoridated/sodic, and chlorinated/sodic, focusing on aging-related skin alterations. Mouse skin fibroblasts and macrophages were exposed to culture medium prepared in different NMWs. Cellular viability was evaluated by MTT assay and etoposide-induced senescence was analyzed through the beta-galactosidase staining kit. Wound healing was investigated by the scratch assay, and phototoxicity/photoprotection after UVA irradiation was evaluated using a neutral red solution. ROS production was quantified using the 2'7'-dichlorofluorescin diacetate dye, and the activity of superoxide dismutase (SOD) was analyzed by a commercial kit after lipopolysaccharide exposure. NMWs within the SBS profile demonstrated anti-senescence activity in skin fibroblasts, along with a variable effect on cellular viability. Among the tested NMWs, two decreased cellular senescence and preserved cell viability and were therefore selected for subsequent studies, together with a SBS NMW with therapeutic indications for dermatologic diseases. Overall, the selected NMW promoted wound healing in skin fibroblasts and activated SOD in macrophages, thus suggesting an anti-oxidant effect. None of the NMWs prevented phototoxicity after UV irradiation. Our results shed a light on the anti-aging potential of Portuguese NMW, supporting their putative application in cosmetic or medical products.

Mannans and mannan oligosaccharides (MOS) from Saccharomyces cerevisiae - A sustainable source of functional ingredients

Sustainable industry practices and circular economy concepts encourage the transformation of production waste into by-products. Saccharomyces cerevisiae is widely used in fermentation industry worldwide, generating large amounts of spent yeast which is mainly directed to animal feed or discarded as waste. Instead of becoming and environmental problem, spent yeast can be directed to the extraction of valuable compounds such as mannans and mannan oligosaccharides (MOS). This review presents a compilation of the studies up to date regarding the different chemical, enzymatic, mechanical or physical processes addressed for mannans extraction and MOS production. Additionally, the existing studies on the chemical modification of mannans aimed to improve specific characteristics are also discussed. Finally, the more relevant bioactivities and potential applications of mannans, MOS and mannose are presented, together with products on the market containing these compounds.

Novel Micro- and Nanocellulose-Based Delivery Systems for Liposoluble Compounds

Poor aqueous solubility of bioactive compounds is becoming a pronounced challenge in the development of bioactive formulations. Numerous liposoluble compounds have very interesting biological activities, but their low water solubility, stability, and bioavailability restrict their applications. To overcome these limitations there is a need to use enabling delivering strategies, which often demand new carrier materials. Cellulose and its micro- and nanostructures are promising carriers with unique features. In this context, this review describes the fast-growing field of micro- and nanocellulose based delivery systems with a focus on the release of liposoluble bioactive compounds. The state of research on this field is reviewed in this article, which also covers the chemistry, preparation, properties, and applications of micro- and nanocellulose based delivery systems. Although there are promising perspectives for introducing these materials into various fields, aspects of safety and toxicity must be revealed and are discussed in this review. The impact of gastrointestinal conditions on the systems and on the bioavailability of the bioactive compounds are also addressed in this review. This article helps to unveil the whole panorama of micro- and nanocellulose as delivery systems for liposoluble compounds, showing that these represent a great promise in a wide range of applications.

Mitochondria, endoplasmic reticulum and innate immune dysfunction in mood disorders: Do Mitochondria-Associated Membranes (MAMs) play a role?

Mood disorders like major depression and bipolar disorder (BD) are among the most prevalent forms of mental illness. Current knowledge of the neurobiology and pathophysiology of these disorders is still modest and clear biological markers are still missing. Thus, a better understanding of the underlying pathophysiological mechanisms to identify potential therapeutic targets is a prerequisite for the design of new drugs as well as to develop biomarkers that help in a more accurate and earlier diagnosis. Multiple pieces of evidence including genetic and neuro-imaging studies suggest that mood disorders are associated with abnormalities in endoplasmic-reticulum (ER)-related stress responses, mitochondrial function and calcium signalling. Furthermore, deregulation of the innate immune response has been described in patients diagnosed with mood disorders, including depression and BD. These disease-related events are associated with functions localized to a subdomain of the ER, known as Mitochondria-Associated Membranes (MAMs), which are lipid rafts-like domains that connect mitochondria and ER, both physically and biochemically. This review will outline the current understanding of the role of mitochondria and ER dysfunction under pathological brain conditions, particularly in major depressive disorder (MDD) and BD, that support the hypothesis that MAMs can act in these mood disorders as the link connecting ER-related stress response and mitochondrial impairment, as well as a mechanisms behind sterile inflammation arising from deregulation of innate immune responses. The role of MAMs in the pathophysiology of these pathologies and its potential relevance as a potential therapeutic target will be discussed.

Bifunctional Porphyrin-Based Nano-Metal-Organic Frameworks: Catalytic and Chemosensing Studies

The use of 5,10,15,20-tetrakis( p-phenylphosphonic acid)porphyrin (H₁₀TPPA) as a linker in the preparation of porphyrin-based metal-organic frameworks (Por-MOFs) through coordination to lanthanides cations is reported. The resulting unprecedented materials, formulated as [M(H₉TPPA)(H₂O) _x]Cl₂· yH₂O [ x + y = 7; M³⁺ = La³⁺ (1), Yb³⁺ (2), and Y³⁺ (3)], prepared using hydrothermal synthesis, were extensively characterized in the solid-state, for both their structure and thermal robustness, using a myriad of solid-state advanced techniques. Materials were evaluated as heterogeneous catalysts in the oxidation of thioanisole by H₂O₂ and as chemosensors for detection of nitroaromatic compounds (NACs). Nano-Por-MOFs 1-3 proved to be effective as heterogeneous catalysts in the sulfoxidation of thioanisole, with Por-MOF 1 exhibiting the best catalytic performance with a conversion of thioanisole of 89% in the first cycle and with a high selectivity for the sulfoxide derivative (90%). The catalyst maintained its activity roughly constant in three consecutive runs. Por-MOFs 1-3 can be employed as chemosensors because of a measured fluorescence quenching up to 70% for nitrobenzene, 1,4-dinitrobenzene, 4-nitrophenol, and phenol, with 2,4,6-trinitrophenol exhibiting a peculiar fluorescence profile.

Porphyrin-Based Metal-Organic Frameworks as Heterogeneous Catalysts in Oxidation Reactions

Porphyrin-based Metal-Organic Frameworks (Por-MOFs) constitute a special branch of the wide MOF family that has proven its own value and high potential in different applications. In this mini-review the application of these materials as catalysts in oxidation reactions is highlighted.

Phosphonate appended porphyrins as versatile chemosensors for selective detection of trinitrotoluene

Fluorescent molecular probes based on phosphonate-functionalized porphyrin derivatives have been designed for selective detection of nitroaromatics. It is shown that molecular recognition is based on cooperative hydrogen bonding and π-π stacking interactions with electron-deficient molecules (nitroaromatic compounds, NACs), displaying superior detection toward trinitrotoluene (TNT). The P═O functional groups decrease the lowest unoccupied molecular orbital (LUMO) energy level of the porphyrins and, consequently, facilitate the electron inoculation to TNT through a photoinduced electron transfer (PET) process. The hydroxyl groups of the phosphonates and pyrrole -NH protons are further engaged in donor-acceptor interactions with TNT by strong intermolecular hydrogen bonding interactions (as evidenced by single crystal X-ray, NMR, and density functional theory (DFT)) showing turn off fluorescence behavior. The nonplanarity of the porphyrins induced by protonation at the central core of the porphyrin H4TPPA(2+) undergoes additional interactions, furnishing an anomalous increase in the selectivity of TNT at nanomolar levels in solution (limit of detection, LOD ∼ 5 nM). Porphyrin-doped hybrid PMMA [poly(methyl methacrylate)] polymer films demonstrate the reversibility of the fluorescence behavior and exhibit high photostability. The formation of discrete molecular aggregates on the surface of hybrid films and efficient diffusion of TNT vapors (10 ppb) displayed high selectivity in the solid state. The hybrid films are further used to demonstrate the detection of NACs in the aqueous medium, ultimately providing a platform for a practical strategy and implementation for the detection of toxic NACs.

BRI2 ectodomain affects Aβ42 fibrillation and tau truncation in human neuroblastoma cells

Alzheimer's disease (AD) is pathologically characterized by the presence of misfolded proteins such as amyloid beta (Aβ) in senile plaques, and hyperphosphorylated tau and truncated tau in neurofibrillary tangles (NFT). The BRI2 protein inhibits Aβ aggregation via its BRICHOS domain and regulates critical proteins involved in initiating the amyloid cascade, which has been hypothesized to be central in AD pathogenesis. We recently detected the deposition of BRI2 ectodomain associated with Aβ plaques and concomitant changes in its processing enzymes in early stages of AD. Here, we aimed to investigate the effects of recombinant BRI2 ectodomain (rBRI276-266) on Aβ aggregation and on important molecular pathways involved in early stages of AD, including the unfolded protein response (UPR), phosphorylation and truncation of tau, as well as apoptosis. We found that rBRI276-266 delays Aβ fibril formation, although less efficiently than the BRI2 BRICHOS domain (BRI2 residues 113-231). In human neuroblastoma SH-SY5Y cells, rBRI276-266 slightly decreased cell viability and increased up to two-fold the Bax/Bcl-2 ratio and the subsequent activity of caspases 3 and 9, indicating activation of apoptosis. rBRI276-266 upregulated the chaperone BiP but did not modify the mRNA expression of other UPR markers (CHOP and Xbp-1). Strikingly, rBRI276-266 induced the activation of GSK3β but not the phosphorylation of tau. However, exposure to rBRI276-266 significantly induced the truncation of tau, indicating that BRI2 ectodomain can contribute to NFT formation. Since BRI2 can also regulate the metabolism of Aβ, the current data suggests that BRI2 ectodomain is a potential nexus between Aβ, tau pathology and neurodegeneration.

5-[4-(Diethoxyphosphoryl)-2,3,5,6-tetrafluorophenyl]-10,15,20-tris(pentafluorophenyl)porphyrin

The title compound, C48H20F19N4O3P, prepared by the nucleophilic attack of triethyl phosphite on one of the 4-fluoro atoms of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin, contains a single molecule in the asymmetric unit. The porphyrin unit is almost planar [largest non-H atom deviation = 0.174 (6) Å], and has the planes of the neighbouring benzene rings oriented at angles ranging from 64.3 (2) to 89.6 (3)° relative to the porphyrin core. The P=O group is almost coplanar with the attached benzene ring, subtending an angle of 4.0 (3)°. Several weak supramolecular interactions, namely C—H...π, C—F...π, P=O...π, C—H...(O,F) and F...F contacts, contribute to the crystal packing.

Mitochondrial control of autophagic lysosomal pathway in Alzheimer's disease

When first described by Alois Alzheimer in 1907, AD was seen as a disorder that causes dementia and characterized by two defining neuropathological lesions, later associated with all forms of AD. While the etiology of AD remains largely unclear, there is accumulating evidence suggesting that mitochondrial dysfunction occurs prior to the onset of symptoms in AD. Mitochondria are exceptionally poised to play a crucial role in neuronal cell survival or death because they are regulators of both energy metabolism and apoptotic pathways. This review is mainly focused in the discussion of evidence suggesting a clear association between mitochondrial dysfunction, autophagy impairment and amyloid-beta accumulation in Alzheimer's disease pathophysiology. The knowledge that autophagic insufficiency may compromise the cellular degradation mechanisms that may culminate in the progressive accumulation of dysfunctional mitochondria, aberrant protein aggregates buildup and lysossomal burden shield new insights to the way we address Alzheimer's disease. In line with this knowledge an innovative window for new therapeutic strategies aimed to activate or ameliorate macroautophagy may be opened.

Interactions of human immunodeficiency virus-1 proteins with neurons: possible role in the development of human immunodeficiency virus-1-associated dementia

Human immunodeficiency virus-1 (HIV-1)-associated dementia is a severe neurological complication of HIV-1 infection that affects 15-20% of the patients in the late stages of acquired immunodeficiency syndrome. HIV-1-associated dementia is most probably a consequence of HIV-1 infection of the brain rather than of an opportunistic pathogen. The exact mechanism by which the virus causes this disorder, however, is not completely understood. A number of HIV-1 proteins have been shown to be released from HIV-1-infected cells and/or to be present in the extracellular milieu in the HIV-1-infected brain. Moreover, these proteins have been shown to possess neurotoxic and/or neuromodulatory features in vitro. This review describes the possible direct interactions of the HIV-1 proteins gp120, gp41, vpr, tat, rev, vpu and nef with neurons, which might play a role in the development of HIV-1-associated dementia in vivo.

Utilization of zeolites synthesized from coal fly ash for the purification of acid mine waters

Two pilot plant products containing 65 and 45% NaP1 zeolite were obtained from two Spanish coal fly ashes (Narcea and Teruel Power Station, respectively). The zeolitic product obtained showed a cation exchange capacity (CEC) of 2.7 and 2.0 mequiv/g, respectively. Decontamination tests of three acid mine waters from southwestern Spain were carried out using the zeolite derived from fly ash and commercial synthetic zeolite. The results demonstrate that the zeolitic material could be employed for heavy metal uptake in the water purification process. Doses of 5-30 g of zeolite/L have been applied according on the zeolite species and the heavy metal levels. Moreover, the application of zeolites increases the pH. This causes metal-bearing solid phases to precipitate and enhances the efficiency of the decontamination process.

Enhanced expression of fractalkine in HIV-1 associated dementia

The CX(3)C chemokine fractalkine was found to be up-regulated in the brain during inflammatory processes. In this study, we tried to assess the role of fractalkine in HIV-1-associated dementia. Fractalkine expression is up-regulated in the brains of AIDS patients with HAD. Fractalkine immunoreactivity was mainly detected in astrocytes. In addition, fractalkine expression was found to be up-regulated in cocultures of astrocytes and HIV-infected macrophages. This up-regulation was dependent on cell-cell contact. We propose that fractalkine produced during interactions between astrocytes and HIV-infected macrophages plays a role in HAD by regulating the trafficking of monocytic cells in the brain parenchyma.

Solidification/stabilization of electric arc furnace dust using coal fly ash. Analysis of the stabilization process

In this paper, the stabilization of electric arc furnace (EAF) dust containing hazardous metals such as Pb, Cd, Cr or Zn is described. The treatment involves a waste solidification/stabilization (S/S) process, using coal fly ash as the fundamental raw material and main binder. The article also contains a brief review of the most important recent publications related to the use of fly ash as S/S agents. The efficacy of the process has been evaluated mainly through leaching tests on the solidified products and compliance with some imposed leachate limits. The concentration of metals leaching from the S/S products was strongly leachate pH dependent; thus, the final pH of the leachate is the most important variable in reaching the limits and, therefore, in meeting the stabilization goals. In this study, the dependence relationship between the leachate pH and the concentrations of metals in the leachate are analyzed; in some cases, this allows us to estimate the speciation of contaminants in the S/S solids and to understand the mechanism responsible for reduced leachability of heavy metals from solidified wastes.

Rotavirus strains bearing genotype G9 or P[9] recovered from Brazilian children with diarrhea from 1997 to 1999

Human rotavirus strains belonging to genotype G9 or P[9] were detected in a collection of stool specimens from children with diarrhea in two cities of the state of Rio de Janeiro, Brazil, between March 1997 and December 1999. G9 strains were first detected in April 1997 and remained prevalent until the end of the study, at a frequency of 15.9% (n = 157). A high percentage of VP7 nucleotide (99.0 to 99.5%) and deduced amino acid identity (98.6 to 99.1%) was found between three randomly selected Brazilian G9 strains and the American G9 strain US1205. A novel G9:P[4] genotype combination was detected in addition to G9:P[8] and G9:P[6], demonstrating that this G genotype may undergo constant genetic reassortment in nature. The P[9] rotavirus strains constituted 10.2%, the majority of which were detected between April and July 1997. The RNA electrophoretic migration pattern of the G3:P[9] strains resembled that of AU-1 virus (G3:P3[9]), suggesting a genetic similarity between the Brazilian G3:P[9] strains and the Japanese virus, which is similar to a feline rotavirus genetically.

Induction of cyclooxygenase-2 expression during HIV-1-infected monocyte-derived macrophage and human brain microvascular endothelial cell interactions

Human immunodeficiency virus type-1 (HIV-1)-associated dementia (HAD) is a neurodegenerative disease characterized by HIV infection and replication in brain tissue. HIV-1-infected monocytes overexpress inflammatory molecules that facilitate their entry into the brain. Prostanoids are lipid mediators of inflammation that result from cyclooxygenase-2 (COX-2) activity. Because COX-2 is normally induced during inflammatory processes, the aim of this study was to investigate whether COX-2 expression is up-regulated during monocyte-brain endothelium interactions. In vitro cocultures of HIV-infected macrophages and brain endothelium showed an up-regulation of COX-2 expression by both cell types. This up-regulation occurs via an interleukin-1beta (IL1beta)-dependent mechanism in macrophages and via an IL-1beta-independent mechanism in endothelial cells. Thus, interactions between HIV-infected monocytes and brain endothelium result in COX-2 expression and, as such, might contribute to the neuropathogenesis of HIV infection.

Oxidative glutamate toxicity involves mitochondrial dysfunction and perturbation of intracellular Ca2+ homeostasis

Glutamate toxicity on PC12 cells is mediated by oxidative stress as a consequence of the inhibition of a cystine uptake system with depletion of GSH. In this study we report that glutamate decreases PC12 cell viability, inhibiting the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). This decrease was prevented by the antioxidants vitamin E, idebenone and L-deprenyl, which were also shown to be effective in reducing the accumulation of reactive oxygen species (ROS) in cells exposed to glutamate, decreasing the fluorescence of 2',7'-dichlorofluorescein (DCF). Incubation of PC12 cells with high glutamate concentrations induced mitochondrial dysfunction, leading to the loss of mitochondrial transmembrane potential, evaluated as a decrease in rhodamine 123 (Rh123) retention by mitochondria, and to the decrease of intracellular ATP levels. The mitochondrial dysfunction, induced by glutamate, can be involved in the observed increase of [Ca2+]i. The elevation of [Ca2+]i occurred after GSH depletion, suggesting that oxidative stress is involved in the disturbances of intracellular calcium homeostasis. In conclusion, our data indicate that glutamate, at concentrations which block cystine uptake in PC12 cells leading to GSH depletion and inducing oxidative stress, increases ROS accumulation and decreases cell survival by a mechanism involving mitochondrial dysfunction and impairment of Ca2+ homeostasis.

Role of macrophage activation in the pathogenesis of Alzheimer's disease and human immunodeficiency virus type 1-associated dementia

The structure and function of neurons are changed not only during development of the central nervous system but also in certain neurological disorders, such as Alzheimer's disease and human immunodeficiency virus type 1 (HIV-1) -associated dementia. Immunological activation and altered production of neurotoxins and neurotrophins by brain macrophages are thought to play an important role in neuronal structure and function. This review describes the clinical and pathological features of both Alzheimer's disease and HIV-1-associated dementia and tries to interpret the role of the macrophage and astrocytes therein. The consequences of activation of macrophages by amyloid-beta in Alzheimer's disease and HIV infection of macrophages in HIV-1-associated dementia and the similarities between these diseases will be discussed. Although the neuropathology of Alzheimer's disease and HIV-1-associated dementia differs, Alzheimer's disease is a cortical dementia and HIV-1-associated dementia is a subcortical dementia, the process of macrophage activation and the resulting pathways leading to neurotoxicity seem very similar. In both Alzheimer's disease and HIV-1-associated dementia, interaction of macrophages and astrocytes appear to play an important role.

Detection of rotavirus types G8 and G10 among Brazilian children with diarrhea

Characterization of 49 rotavirus-positive stool specimens from children with diarrhea in the state of Rio de Janeiro, Brazil, in 1996 and 1997 revealed a great diversity of rotavirus G types. Conventional types G1 and G3 accounted for 27 and 12% of the infections, respectively, whereas 60% of the infections were caused by unconventional types G5 (25%), G10 (16%), and G8 (4%) and mixed G types (16%).