Evaluation of the Expression of Amyloid Precursor Protein and the Ratio of Secreted Amyloid Beta 42 to Amyloid Beta 40 in SH-SY5Y Cells Stably Transfected with Wild-Type,Single-Mutant and Double-Mutant Forms of the APP Gene for the Study of Alzheimer’s Disease Pathology

Neuroblastoma cell lines such as SH-SY5Y are the most frequently utilized models in neurodegenerative research, and their use has advanced the understanding of the pathology of neurodegeneration over the past few decades. In Alzheimer’s disease (AD), several pathogenic mutations have been described, all of which cause elevated levels of pathological hallmarks such as amyloid-beta (Aβ). Although the genetics of Alzheimer’s disease is well known, familial AD only accounts for a small number of cases in the population, with the rest being sporadic AD, which contains no known mutations. Currently, most of the in vitro models used to study AD pathogenesis only examine the level of Aβ42 as a confirmation of successful model generation and only perform comparisons between wild-type APP and single mutants of the APP gene. Recent findings have shown that the Aβ42/40 ratio in cerebrospinal fluid (CSF) is a better diagnostic indicator for AD patients than is Aβ42 alone and that more extensive Aβ formation, such as accumulation of intraneuronal Aβ, Aβ plaques, soluble oligomeric Aβ (oAβ), and insoluble fibrillar Aβ (fAβ) occurs in TgCRND8 mice expressing a double-mutant form (Swedish and Indiana) of APP, later leading to greater progressive impairment of the brain. In this study, we generated SH-SY5Y cells stably transfected separately with wild-type APP, the Swedish mutation of APP, and the Swedish and Indiana mutations of APP and evaluated the APP expression as well as the Aβ42/40 ratio in those cells. The double-mutant form of APP (Swedish/Indiana) expressed markedly high levels of APP protein and showed a high Aβ2/40 ratio compared to wild-type and single-mutant cells.     

A Comparison of Solar Ultraviolet Radiation Exposure in Urban Canyons in Venice,Italy and Johannesburg,South Africa

Urban environments can have high-risk spaces that can provide excess personal sun exposure, such as urban or street canyons, and the spaces between buildings, among others. In these urban spaces, sun exposure can be high or low depending on several factors. Polysulphone film (PSF) was used to assess possible daily solar ultraviolet radiation (UVR) exposure in urban canyons in Venice, Italy and, for the first time in Africa, in Johannesburg, South Africa. The photodegradation of PSF upon solar exposure was monitored at a wavelength of 330 nm by ultraviolet-visible spectrophotometry, and the resultant change was converted to standard erythemal dose (SED) units (1 SED = 100 J m⁻²). Mean daily ambient solar UVR exposure measured for Venice and Johannesburg ranged between 20–28 SED and 33–43 SED, respectively. Canyon-located PSF exposures were lower in Venice (1–9 SED) than those in Johannesburg (9–39 SED), depending mainly on the sky view factor and orientation to the sun. There was large variation in solar UVR exposure levels in different urban canyons. These preliminary results should be bolstered with additional studies for a better understanding of excess personal exposure risk in urban areas, especially in Africa.     

Kinase inhibitory, haemolytic and cytotoxic activity of three deep-water sponges from North Western Australia and their fatty acid composition

The c-AMP dependent protein kinase (PKA) inhibition, haemolytic activity, and cytoxicity of 21 extracts obtained from North Western Australian sponges collected from depths of 84-135 m were investigated. Hexane extracts from Ircinia/Sarcotragus sp. and Geodia sp. displayed PKA inhibitory activities of 100 and 97% respectively (at 100 microg/mL), while aq. methanol extracts from Haliclona sp. exhibited potent haemolytic activity (75%) and hexane extracts from Geodia sp. were highly toxic (88%) to the brine shrimp Artemia franciscana. As the non-polar extracts gave the greatest PKA inhibition, these were further analysed by GC-MS and 29 fatty acids were identified in the highest proportions in Ircinia/Sarcotragus sp. > Haliclona sp. > Geodia sp. In contrast to shallow-water sponges that are dominated by polyunsaturated fatty acids with a high percentage of long chain fatty acids, LCFAs (C24-C30), the deep-sea sponges investigated herein were all found to be rich in saturated fatty acids, in particular C14-C20 fatty acids, including odd and branched chain fatty acids, with only low levels (0-10%) of LCFAs. Screening of the PKA inhibitory activity of a series of commercially available fatty acids identified C14-C18 fatty acids as possessing significant PKA inhibitory activity that may contribute to the activity observed in the sponges studied.     

Effect of Feed Strategy on Methane Production and Performance of an AnSBBR Treating Effluent from Biodiesel Production

The aim of this work was to investigate the effect of different feeding times (2, 4 and 6 h) and applied volumetric organic loads (4.5, 6.0 and 7.5 gCOD L⁻¹ day⁻¹) on the performance of an anaerobic sequencing batch biofilm reactor (AnSBBR) treating effluent from biodiesel production. Polyurethane foam cubes were used as inert support in the reactor, and mixing was accomplished by recirculating the liquid phase. The effect of feeding time on reactor performance showed to be more pronounced at higher values of applied volumetric organic loads (AVOLs). Highest organic material removal efficiencies achieved at AVOL of 4.5 gCOD L⁻¹ day⁻¹ were 87 % at 4-h feeding against 84 % at 2-h and 6-h feeding. At AVOL of 6.0 gCOD L⁻¹ day⁻¹, highest organic material removal efficiencies achieved with 4-h and 6-h feeding were 84 %, against 71 % at 2-h feeding. At AVOL of 7.5 gCOD L⁻¹ day⁻¹, organic material removal efficiency achieved with 4-h feeding was 77 %. Hence, longer feeding times favored minimization of total volatile acids concentration during the cycle as well as in the effluent, guaranteeing process stability and safety.     

The Ideal Structure of Semigroups of Linear Transformations with Upper Bounds on Their Nullity or Defect

Suppose V is a vector space with dim V = p ≥ q ≥ ?₀, and let T(V) denote the semigroup (under composition) of all linear transformations of V. For α ∈ T (V), let ker α and ran α denote the “kernel” and the “range” of α, and write n(α) = dim ker α and d(α) = codim ran α. In this article, we study the semigroups AM(p, q) = {α ∈ T(V):n(α) < q} and AE(p, q) = {α ∈ T(V):d(α) < q}. First, we determine whether they belong to the class of all semigroups whose sets of bi-ideals and quasi-ideals coincide. Then, for each semigroup, we describe its maximal regular subsemigroup, and we characterise its Green's relations and (two-sided) ideals. As a precursor to further work in this area,, we also determine all the maximal right simple subsemigroups of AM(p, q).     

Fluorescence Spectroscopy of Porphyrins and Phthalocyanines: Some Insights into Supramolecular Self-Assembly,Microencapsulation, and Imaging Microscopy

The molecular interactions of anionic tetrasulfonate phenyl porphyrin (TPPS) with poly(amido amine) (PAMAM) dendrimers of generation 2.0 and 4.0 (G2 and G4, respectively) forming H- or J-aggregates, as well as with human and bovine serum albumin proteins (HSA and BSA), were reviewed in the context of self-assembly molecular complementarity. The spectroscopic studies were extended to the association of aluminum phthtalocyanine (AlPCS₄) detected with a PAMAM G4 dendrimer with fluorescence studies in both steady state and dynamic state, as well as due to the fluorescence quenching associated to electron-transfer with a distribution of lifetimes. The functionalization of TPPS with peripheral substituents enables the assignment of spontaneous pH-induced aggregates with different and well-defined morphologies. Other work reported in the literature, in particular with soft self-assembly materials, fall in the same area with particular interest for the environment. The microencapsulation of TPPS studies into polyelectrolyte capsules was developed quite recently and aroused much interest, which is well supported and complemented by the extensive data reported on the Imaging Microscopy section of the Luminescence of Porphyrins and Phthalocyanines included in the present review.     

Thallus structure and isidium development in two Parmeliaceae species (lichenized Ascomycota)

(Thallus structure and isidium development in two Parmeliaceae species (lichenized Ascomycota)). Conventional techniques for structural studies under light microscope and scanning electron microscope were employed to describe and compare the histology of thallus and isidia development in Parmotrema tinctorum and Parmelinopsis minarum. Although presenting layers typical of the heteromerous structure of Parmeliaceae lichens, the studied species have very distinct anatomical details including: the type of upper cortex, medulla thickness, hyphal orientation pattern and distinct strata in this layer, variations of crystal shape, color, location and degree of association with medullary hyphae, rhizines thickness and covering by a cortical layer. Isidium formation starts with cortical cell proliferation, which results in a small protuberance on the thallus surface, followed by the photobiont cell proliferation. Medullary hyphal intrusions occur only after the formation of this protuberance. In this stage medullary hyphae grow, ramifying or not inside the protuberance. In a posterior stage, the isidium base becomes constricted, which facilitates its detachment from the thallus.     

(−)-epi-Presilphiperfolan-1-ol, a new triquinane sesquiterpene from the essential oil of Anemia tomentosa var. anthriscifolia (Pteridophyta)

(−)-epi-Presilphiperfolan-1-ol, (1), a new triquinane sesquiterpene, was isolated from the essential oil of Anemia tomentosa var. anthriscifolia by column chromatography. Its structure elucidation was accomplished by extensive 1D- and 2D-NMR analyses, as well as by GC-MS, chiral bidimensional GC, dehydration reactions, and a comparative (GIAO/DFT) theoretical study of the ¹³C NMR chemical shifts of 1 and its known isomers (presilphiperfolan-1-ol (1a), presilphiperfolan-8-ol (3), and presilphiperfolan-9-ol (4)).     

Chromatographic descriptors in QSAR study of barbiturates

Barbiturate derivatives were evaluated for their parameters of biological activity by applying linear regression and two multivariate methods (Cluster analysis and Principal component analysis). The lipophilicity of the studied barbiturates was determined on the modified carriers C18 in mixtures of water and four organic modifiers separately (methanol, n-propanol, acetone and tetrahydrofuran) by performing reversed phase thin layer chromatography and by applying relevant software packages. Chromatographic and computational lipophilicity of the examined barbiturates was correlated with the selected pharmacokinetic and toxicological predictors and good relationships were obtained. More concrete results were obtained by multivariate methods which showed that the polarity of the substituent has the greatest influence, and its electronic effects to a lesser extent on the tested parameters of the barbiturate derivatives. Results obtained by multivariate methods also suggest that the chromatographic retention constant, R_M⁰, shows a greater resemblance to the parameters of lipophilicity. The chromatographic parameter m, exhibits better agreement with the toxicity parameters.