Biochemical analysis of Hyalomma dromedarii salivary glands and gut tissues using SR-FTIR micro-spectroscopy.

Ticks are obligatory voracious blood feeders infesting diverse vertebrate hosts, that have a crucial role in the transmission of diverse pathogens that threaten human and animal health. The continuous emergence of tick-borne diseases due to combined worldwide climatic changes, human activities, and acaricide-resistant tick strains, necessitates the development of novel ameliorative tick control strategies such as vaccines. The synchrotron-based Fourier transform infrared micro-spectroscopy (SR-FTIR) is a bioanalytical microprobe capable of exploring the molecular chemistry within microstructures at a cellular or subcellular level and is considered as a nondestructive analytical approach for biological specimens. In this study, SR-FTIR analysis was able to explore a qualitative and semi-quantitative biochemical composition of gut and salivary glands of Hyalomma dromedarii (H. dromedarii) tick detecting differences in the biochemical composition of both tissues. A notable observation regarding Amide I secondary structure protein profile was the higher ratio of aggregated strands in salivary gland and beta turns in gut tissues. Regarding the lipid profile, there was a higher intensity of lipid regions in gut tissue when compared to salivary glands. This detailed information on the biochemical compositions of tick tissues could assist in selecting vaccine and/or control candidates. Altogether, these findings confirmed SR-FTIR spectroscopy as a tool for detecting differences in the biochemical composition of H. dromedarii salivary glands and gut tissues. This approach could potentially be extended to the analysis of other ticks that are vectors of important diseases such as babesiosis and theileriosis.

The African Light Source: history, context and future.

The African Light Source (AfLS) project is now almost eight years old. This article assesses the history, current context and future of the project. There is by now considerable momentum in building the user community, including deep training, facilitating access to current facilities, growing the scientific output, scientific networks and growing the local laboratory-scale research infrastructure. The Conceptual Design Report for the AfLS is in its final editing stages. This document specifies the socio-economic and scientific rationales and the technical aspects amongst others. The AfLS is supported by many national and Pan-African scientific professional bodies and voluntary associates across many scientific disciplines, and there are stakeholders throughout the continent and beyond. The current roadmap phases have expanded to include national and Pan-African level conversations with policy makers through new Strategic Task Force groups. The document summarizes this progress and discusses the future of the project.

Synchrotron Fourier-Transform Infrared Microspectroscopy: Characterization of in vitro polarized tumor-associated macrophages stimulated by the secretome of inflammatory and non-inflammatory breast cancer cells.

Studies suggested that the pathogenesis of inflammatory breast cancer (IBC) is related to inflammatory manifestations accompanied by specific cellular and molecular mechanisms in the IBC tumor microenvironment (TME). IBC is characterized by significantly higher infiltration of tumor-associated macrophages (TAMs) that contribute to its metastatic process via secreting many cytokines such as TNF, IL-6, IL-8, and IL-10 that enhance invasion and angiogenesis. Thus, there is a need to first understand how IBC-TME modulates the polarization of TAMs to better understand the role of TAMs in IBC. Herein, we used gene expression signature and Synchrotron Fourier-Transform Infrared Microspectroscopy (SR-µFTIR) to study the molecular and biochemical changes, respectively of in vitro polarized TAMs stimulated by the secretome of IBC and non-IBC cells. The gene expression signature showed significant differences in the macrophage's polarization-related genes between stimulated TAMs. FTIR spectra showed absorption bands in the region of 1700-1500 cm-1 attributed to the amide I ν(C=O), & νAS (CN), δ (NH), and amide II ν(CN), δ (NH) proteins bands. Moreover, three peaks of different intensities and areas were detected in the lipid region of the νCH2 and νCH3 stretching modes positioned within the 3000-2800 cm-1 range. The PCA analysis for the second derivative spectra of the amide regions discriminates between stimulated IBC and non-IBC TAMs. This study showed that IBC and non-IBC TMEs differentially modulate the polarization of TAMs and SR-µFTIR can determine these biochemical changes which will help to better understand the potential role of TAMs in IBC.

Synchrotron-Radiation-Based Fourier Transform Infrared Microspectroscopy as a Tool for the Differentiation between Staphylococcal Small Colony Variants.

Small colony variants (SCVs) are clinically significant and linked to persistent infections. In this study, synchrotron-radiation-based Fourier transform infrared (SR-FTIR) is used to investigate the microspectroscopic differences between the SCVs of Staphylococcus aureus (S. aureus) and diabetic foot Staphylococcus epidermidis (S. epidermidis) in two main IR spectral regions: (3050-2800 cm-1), corresponding to the distribution of lipids, and (1855-1500 cm-1), corresponding to the distribution of protein amide I and amide II and carbonyl vibrations. SR-FTIR successfully discriminated between the two staphylococcal species and between the SCV and the non-SCV strains within the two IR spectral regions. Combined S. aureus SCVs (SCVhMu) showed a higher protein content relative to the non-SCV wild type. Complemented S. aureus SCV showed distinguishable differences from the SCVhMu and the wild type, including a higher content of unsaturated fatty acids. An increase in the CH2/CH3 ratio was detected in S. epidermidis SCV samples compared to the standard control. Protein secondary structure in standard S. epidermidis and SCVs consisted mainly of an α-helix; however, a new shoulder at 1635 cm-1, assigned to ß-sheets, was evident in the SCV. In conclusion, SR-FTIR is a powerful method that can discriminate between staphylococci species and to differentiate between SCVs and their corresponding natural strains.

Plasma drop and thin-film revealed distinguished molecular structure in pre-eclampsia: An investigation using synchrotron Fourier-transform infrared microspectroscopy.

Pre-eclampsia (PE) is a serious pregnancy-related disorder and the leading cause of maternal and fetal mortality and morbidity worldwide. The etiology of PE is poorly understood and a definitive diagnosis is still lacking. Herein, we used synchrotron-FTIR microspectroscopy as a new analytical tool to investigate the molecular changes in the structure and intensity of lipids (spectral range 3050-2800 cm-1) and protein-carbonyl (spectral range 1855-1485 cm-1) components of the plasma and link them to the pathogenesis of the disease. In the lipid region, an increase in the CH2 and CH3 peaks intensity was noticed in PE group compared to normotensive pregnancy reflecting abnormalities in the lipid profile and a high level of LDL. Increased CH2/CH3 ratio and red shifts were observed in the lipid region in PE highlighting structural variations of lipids and transformation of conformation of lipid tails. In the protein-carbonyl region, a decrease in the amide I and II absorption signals in the plasma of PE compared to normotensive controls was evident, and a red shift was noticed in the amide I region reflecting conformational changes and rearrangement in the α-helix secondary structure of the protein. Moreover, malondialdehyde level and lipid carbonyl peak at 1743 cm-1 were higher and more intense in PE due to the oxidative stress condition in PE. Spectral analysis of plasma drop from PE revealed that lipid and protein components tend to concentrate more in the central region of the drop, and that the most intense wavenumber values for the lipid and amide I region in the plasma drop were very comparable to their analogous in plasma film. Taken together, the current work provides evidence of the promising role of synchrotron-FTIR microspectroscopy in providing a better understanding of the pathophysiology of PE.

Investigating the molecular structure of plasma in type 2 diabetes mellitus and diabetic nephropathy by synchrotron Fourier-transform infrared microspectroscopy.

Diabetes mellitus (DM) is associated with a high incidence of morbidity and mortality which, in many cases, is derived from the progressive kidney dysfunction due to diabetic nephropathy (DN). In this study, synchrotron-Fourier-transform infrared (SR-FTIR) microspectroscopy was used to identify molecular changes in the lipid and protein regions in the plasma of patients with different stages of DN (mild, moderate, severe and end-stage), and patients with type 2 diabetes mellitus (T2DM) without DN. Our results revealed different conformational changes in the proteins secondary structure between DN stages, and between DN and T2DM groups illustrated by peak shifts and intensity alterations. End-stage DN showed the highest CH2/CH3 ratio and intensity of the carbonyl group in protein-carbonyl region compared to other DN stages indicating high level of unsaturation and lipid peroxidation and oxidation conditions. Moreover, end-stage DN group was characterized by a decrease in amide I and amide II absorption signals which reflected a sign of hypoalbuminemia. When compared to T2DM, DN group demonstrated a higher oxidation state as confirmed via the high intensity of the carbonyl group and the high level of malondialdehyde. The current study highlights the promising role of SR-FTIR microspectroscopy as a new sensitive analytical approach that can be used to provide better understanding of the pathophysiology of DN, and guide the development of new preventive therapies and treatments.

The first infrared beamline at the Middle East SESAME synchrotron facility.

SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) is the only synchrotron light facility in the Middle East and neighboring regions, officially opened in 2017. Among the identification and construction of the first operational beamlines, infrared spectromicroscopy was selected as one of the two beamlines to be opened to the general users' program (the so-called Day-1 beamlines). Being one of the most demanded techniques by various scientific communities in the Middle East, the beamline has been designed and implemented in the framework of a collaboration agreement with the French synchrotron facility, SOLEIL. The design, construction and initial performances of the IR beamline (D02-IR), nowadays operational, are reported.

Mummified embalmed head skin: SR-FTIR microspectroscopic exploration.

This case report details the examination of the skin of an Egyptian mummified head with a possible skin disorder. The head, thought to be dated in the first half of the 18th Dynasty, New Kingdom (1570-1400 BCE) belongs to the Museum of Forensic Anthropology, University of Madrid. Initial histological examination demonstrated evidence of chronic inflammation, which was confirmed by immunohistochemistry and Transmission Electron Microscopy (TEM). However, confirmation of pathology could be confounded by both the age of the specimen and the process of preservation by mummification. In this case report, Synchrotron Radiation Fourier Transform Microspectroscopy (SR-µFTIR) was used to add novel insights into embalmed mummified tissue. More precisely, FTIR is used for the first time on the specific specimens, while no other similar studies have been performed on these samples priorly. Additionally, modern skin tissue was examined too, in order to compare the amount of degradation to the mummified one. Whilst the FTIR results confirmed the results from the initial histological study, they also showed a biochemical modification of the mummified skin that could be indicative of tissue degradation. The latter was supported by comparing it to FTIR results of the modern tissue used.

Synchrotron Fourier transform infrared microspectroscopy (sFTIRM) analysis of unfolding behavior of electrospun collagen nanofibers.

Collagen nanofibers are popular extracellular matrix (ECM) materials in regenerative medicine. Electrospinning of collagen dissolved in organic solvents is widely used for fabricating anisotropic collagen nanofibers; however, such fibers are water-soluble and require cross-linking before use as scaffolds for cell culture. Herein, in-situ crosslinking during electrospinning process is suggested by using different chemical agents, namely genipin and glutaraldehyde, and physical crosslinking method (UV light). sFTIRM; Synchrotron Fourier-Transform Infrared Microspectroscopy is a powerful tool that sheds light on the molecular structure of collagen nanofibers. Applied extraction methods caused shifts on protein band positions. Electrospinning process prevents self-assembly of collagen molecules and obtained electrospun collagen nanofibers have lower band positions. Crosslinkers have effect on the secondary structure of collagen molecules. Among different crosslinkers, genipin in-situ crosslinking process perform better in preserving the native structure of electrospun collagen nanofibers than the physical crosslinking method (UV).

Synchrotron Fourier transform infrared microspectroscopy (sFTIRM) analysis of Al-induced Alzheimer's disease in rat brain cortical tissue.

Aluminium (Al) is reported to promote beta amyloid (Aß) aggregation, free radical production and disturb acetylcholine metabolism leading to cognitive dysfunction that are strongly associated with Alzheimer's disease (AD). Here we utilized synchrotron Fourier transform infrared microspectroscopy (sFTIRM) to analyse the fine structure of proteins and lipids in the rat cortical brain tissues in response to AlCl3 toxicity and Lepidium sativum (LS) treatment after 42 and 65 days. For statistical analysis, we used principal component analysis (PCA). Our results showed profusion of gauche rotomers form in membrane lipid acyl chains that increases the membrane fluidity and disorder only in AD group indicated by the detected sνCH2 band shift to higher frequency. All half bands width (HBW) values of the decomposed amide I band showed marked decrease in AD group compared to the other tested groups, together with an increase in the amounts of ß-sheets (1641 cm-1) protein and random coil structure (1654 cm-1). These were indicated by a drastic increase in the percentage areas ratios of (1638 cm-1/1654 cm-1) and (1641 cm-1/1654 cm-1) that may be attributed to a stronger the hydrogen bonds that stabilize the protein conformational structure and/or the increase of the ß-strand length due to misfolded Aß formation in response to Al toxicity through transit phase/phases dominated by random coil structure. In curative group, LS treatment reversed these changes and restored the protein and lipid integrities. To conclude, sFTIRM is a powerful tool that shed light on the biomolecular structure of AD-like cortical brain tissue and considered the therapeutic potential of LS as a promising natural AD treatment.

Investigating the molecular structure of placenta and plasma in pre-eclampsia by infrared microspectroscopy.

Pre-eclampsia (PE) is a serious hypertensive disorder with unclear etiology and lack of reliable diagnostic tests. In this study, IR microspectroscopy was applied to identify molecular changes associated with the pathogenesis of PE in placental tissues and plasma samples from pre-eclamptic women and normotensive matched controls. The obtained spectra were analyzed by multivariate analysis in the spectral ranges of 3050-2800 cm-1 and 1855-1485 cm-1 corresponding to lipid and protein-carbonyl components, respectively. In the lipid region, an increase in CH2/CH3 ratio was noticed and higher level of unsaturation index in placenta was evident. New lipid species emerged as a consequence of oxidative stress. The more intense peak at 1740 cm-1 in PE reflected higher level of LDL and VLDL. In the protein region, a decrease in the α-helix structure associated with gain in ß-sheet and ß-turn structures was detected. Our results revealed significant conformational changes in the protein secondary structure in PE illustrated by peak shifts and intensity alterations, particularly in amide I component. Variations in lipid order, membrane integrity, fatty acid saturation and plasma lipid profile were also detected in PE. The ROC curve generated from plasma samples yielded AUC values of 98.4% and 99.9% for lipid and protein-carbonyl regions, respectively. The current study shed light on the promising role of IR microspectroscopy as a new analytical tool that can aid in providing better diagnosis and understanding of the pathophysiology of PE.

Monosialoganglioside-GM1 triggers binding of the amyloid-protein salmon calcitonin to a Langmuir membrane model mimicking the occurrence of lipid-rafts.

GM1 ganglioside is known to be involved in the amyloid-associated diseases and it is a crucial factor for the assembly of amyloid proteins on lipid-rafts, which are lipid structures located on the synaptic plasma membranes. Due to its slow aggregation rate, we employed salmon calcitonin (sCT) as a suitable probe representative of amyloid proteins, to study the interaction between this class of proteins and a membrane model. Here, we prepared a neuronal membrane model by depositing onto mica two Langmuir-Blodgett films in liquid-condensed phase: the outer monolayer was characterized by high content of GM1 (50%) and minority parts of cholesterol and POPC (25-25%), while the inner one by plain POPC. To deeply investigate the interaction of sCT with this model and the role-played by GM1, we prepared the outer leaflet adding sCT at a concentration such that the number of proteins equals that of GM1. Atomic Force Microscopy revealed the occurrence of two distinct kinds of flat surfaces, with globular aggregates localized exclusively on top of the highest one. To unravel the nature of the interaction, we studied by ζ-potential technique liposomes composed as the outer leaflet of the model. Results demonstrated that an electrostatic interaction sCT-GM1 occurred. Finally, to investigate the interaction thermodynamics between sCT and the outer leaflet, Langmuir films as the outer monolayer and containing increasing content of sCT were studied by compression isotherms and Brewster Angle Microscopy experiments. Based on the all body of results we propose an interaction model where GM1 plays a pivotal role.

Second-order susceptibility spectra for δ-BiB3O6 polymer nanocomposites deposited on the chalcogenide crystals.

The optimized conditions for the enhancement of the second harmonic generation in the composites of the orthorhombic δ-BiB3O6:Pr(3+) nanoparticles embedded in polyvinyl alcohol films and deposited on the AgGaGe2Se6, AgGaGe2.7Si0.3Se8 (90 mol.% AgGaGe3Se8 - 10 mol.% AgGaSi3Se8), and AgGaGe3Se8:Cu substrates were established. The highest second-order susceptibility was achieved during the Ag-Ga-Ge-Se crystalline substrates photo-illumination by nanosecond laser pulses of about 2900 nm wavelength. The effect was found to be completely reversible after the interruption of the photo-inducing stimulation. Complementary studies of Atomic Force Microscopy, AFM, X-ray Diffraction, XRD, and Fourier-Transform Infrared Spectroscopy, and DFT simulations of spectral dependences of the corresponding second-order nonlinear optical susceptibilities, were performed.

Design and synthesis of some 3-substituted-2-[(2,4-dichlorophenoxy)-methyl]quinazolin-4(3H)-one derivatives as potential anticonvulsant agents.

Series of 2,3-disubstituted quinazolinone derivatives and a [1,2,4]triazino[2,3-c]quinazolinone featuring the pharmacophoric elements of anticonvulsant drugs were designed and synthesized. Target compounds were screened for their anticonvulsant activity using the subcutaneous pentylenetetrazole (s.c. PTZ) and maximal electroshock (MES) models. The s.c. PTZ test showed that the most active compound was the amide derivative 9c having a protective dose 50 (PD50) of 200.53 µmol/kg (PD50 of phenobarbitone=62.18 µmol/kg); nevertheless, this low potency is outweighed by the much higher safety profile of 9c (LD50 >3000 mg/kg). In the MES screening, seven compounds were equal to or more active than phenytoin; some of these compounds were less neurotoxic than phenytoin. Few compounds such as 9c and 10 were effective in both models. LD50 for the most active compounds was calculated.

New quinazolinone-pyrimidine hybrids: synthesis, anti-inflammatory, and ulcerogenicity studies.

Two groups of hybrid compounds: the quinazolinone-dihydropyrimidines and quinazolinone-pyrimidines, were synthesized. The starting derivative 3 was reacted with chloroacetyl chloride to give intermediate 5 which was condensed with the 2-mercaptopyrimidines 4a-c affording compounds 6a-c. These latter compounds underwent hydrolysis and N-alkylation reactions to give the dihydropyrimidine derivatives 7a-c and 8a-f, respectively. The chloro derivatives 9a-c subsequently reacted with various anilines furnishing compounds 10a-i. The anti-inflammatory activity of the synthesized compounds were evaluated using the carrageenan-induced rat paw oedema model and ulcer indices for the most active compounds were calculated. Five compounds were found more active and less ulcerogenic than diclofenac particularly compound 10 g (IC(50) = 116.73 µmol/kg; ulcer index = 11.38). Compound 10 g was also 2-fold more selective inhibitor of COX-2 than COX-1.

Minimally resolution biased electron-density maps.

Electron-density maps are calculated by Fourier syntheses with coefficients based on structure factors. Diffraction experiments provide intensities up to a limited resolution; as a consequence, the Fourier syntheses always show series-termination errors. The worse the resolution, the less accurate is the Fourier representation of the electron density. In general, each atomic peak is shifted from the correct position, shows a deformed (with respect to the true distribution of the electrons in the atomic domain) profile, and is surrounded by a series of negative and positive ripples of gradually decreasing amplitude. An algorithm is described which is able to reduce the resolution bias by relocating the peaks in more correct positions and by modifying the peak profile to better fit the real atomic electron densities. Some experimental tests are performed showing the usefulness of the procedure.