Diagnosis of intrahepatic cholangiocarcinoma by Raman spectroscopy provides high efficiency: A protocol for systematic review and meta-analysis

Background:We aim to evaluate the efficiency of Raman spectroscopy (RS) in diagnosing suspected patients with intrahepatic cholangiocarcinoma (ICC), manifested by diagnostic sensitivity, specificity, and accuracy.Methods:We will research widely the articles concerning the use of RS in ICC through authenticated database including PubMed/Medline, EMBASE, Web of Science, Ovid, Web of Knowledge, Cochrane Library, and CNKI between January 2012 and November 2020, retrieving at least 1500 spectra with strict criteria. This study will be carried out in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We are going to summarize the test performance using random effects models.Results:Based on the pooled sensitivity, specificity, and diagnostic accuracy, we intend to provide the relative diagnostic efficiency in ICC through RS.Conclusion:Through this systematic review and meta-analysis, we intend to provide the pooled sensitivity, specificity and diagnostic accuracy of RS in the diagnosis of suspected ICC. Other parameters like positive likelihood ratios (LR), negative LR, diagnostic odds ratio (DOR), and area under curve (AUC) of the summary receiver operating characteristics (SROC) curve will also be calculated and related figures will be drawn to help illustrate the efficacy of RS in the diagnosis of ICC.     

Cellular mechanisms of hereditary photoreceptor degeneration – Focus on cGMP

The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations.In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca²⁺-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca²⁺-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development.Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.     

Mass-fractal-like microstructure and proton disorder in nanostructured pseudoboehmite: a neutron-scattering study

Boehmite (γ-AlOOH) is often the initial product in sol–gel syntheses of high surface-area alumina powders. Depending on the processing routes, the microstructure of an AlOOH powder can be tailored to exhibit nanometer particle size and complex interfacial OH sites. Neutron small-angle scattering (SANS) and spectroscopy were utilized to characterize the microstructure and hydrogen vibrations of a nanostructured pseudoboehmite and a highly crystallized boehmite powder. The SANS data reveal a mass-fractal-like microstructure in pseudoboehmite. The vibrational bands of hydrogen atoms in pseudoboehmite are broad, which is indicative of a high degree of proton delocalization and disordered OH sites.     

Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties--a comparison between mobile bearing and fixed bearing knees.

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).     

Raman and UV–vis spectroscopic study of polyaniline membranes containing a bulky cationic additive

Electrically conducting soluble polyaniline (PANI), containing different amounts of a bulky lipophilic cationic additive, tridodecylmethylammonium chloride (TDMACl), was studied by Raman (λ_exc=780 nm) and UV–vis spectroscopy. PANI was made simultaneously electrically conducting and soluble with bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphoric acid in dichloromethane. The PANI membranes were prepared by drop casting on glassy carbon or ITO substrates. Raman and UV–vis measurements were carried out in a 0.1 M CaCl₂ solution at potentials between 400 and ?600 mV (vs. SCE) at pH 6, or alternatively at the open circuit potential at pH 10. The results of Raman, UV–vis and cyclic voltammetric measurements confirm that the incorporation of TDMACl into the PANI membrane facilitates the oxidation and reduction of PANI.     

Spectrometric investigations in ocular hypertension and early stages of primary open angle glaucoma and of low tension glaucoma — multisubstance analysis

The approximation of logarithmic difference spectra between the reflectance of the normal fundus and the fundus reflectance in different stages of glaucoma is demonstrated by a model. The influences of fundus pigments like oxihemoglobin, melanin, xanthophyll and rhodopsin as well as the intensity and the exponent of the scattered light are optimized. Glaucomatous alterations in the extinction of these pigments and of the scattering parameters are different in the macula, in the papillo-macular bundle and in the parapapillary region temporal to the optic disc. A lack of oxihemoglobin only in the papillo-macular bundle in first relative losses in the visual field function points to a damaged microcirculation in early POAG. In progressive glaucoma the extinction spectrum of xanthophyll is detectable in the papillo-macular bundle. A decreased intensity of the scattered light and an altered scattering exponent are suggestive of a damage in the nerve fiber layer at early stages of glaucoma.     

Infection dynamics and virus-induced apoptosis in cell culture-based influenza vaccine production—Flow cytometry and mathematical modeling

Cell culture-based influenza vaccine manufacturing is of growing importance. Depending on virus strains, differences in infection dynamics, virus-induced apoptosis, cell lysis and virus yields are observed. Comparatively little is known concerning details of virus–host cell interaction on a cellular level and virus spreading in a population of cells in bioreactors. In this study, the infection of MDCK cells with different influenza A virus strains in lab-scale microcarrier culture was investigated by flow cytometry. Together with the infection status of cells, virus-induced apoptosis was monitored. A mathematical model has been formulated to describe changes in the concentration of uninfected and infected adherent cells, dynamics of virus particle release (infectious virions, hemagglutinin content), and the time course of the percentage composition of the cell population.     

Dynamics of ablation plume particles generated during excimer laser corneal ablation

Background and Objective: Although the empirical characteristics of ArF excimer laser corneal ablation have been well documented, the exact ablation mechanisms are not well understood. The present paper reports a quantitative analysis of corneal ablation plumes using in situ time resolved laser light scattering and Raman spectroscopy. Study Design/Materials and Methods: Bovine corneas were used as the ArF excimer laser ablation targets. Light scattering data were recorded from the ablation plume as a function of height above the tissue surface and as function of delay time with respect to the ablative ArF laser pulse. Results: Raman spectra of the ablation plume allow identification of the particles as water. Mean plume particle diameters are found to decrease with height, while the particle volume fractions are relatively constant. The total volume of plume particles correlates well with the total volume of water in the ablated corneal tissue. Conclusion: The finding of a non-evolving plume composed of water spherules, combined with the excellent agreement between total volume of water in the plume and the content of water in the ablated corneal tissue, support the concept of photodecomposition or “cold ablation” for corneal tissue during ArF excimer laser ablation. © 1995 Wiley-Liss, Inc.     

A small angle light scattering device for planar connective tissue microstructural analysis

The planar fibrous connective tissues of the body are composed of a dense extracellular network of collagen and elastin fibers embedded in a ground matrix, and thus can be thought of as biocomposites. Thus, the quantification of fiber architecture is an important step in developing an understanding of the mechanics of planar tissues in health and disease. We have used small angle light scattering (SALS) to map the gross fiber orientation of several soft membrane connective tissues. However, the device and analysis methods used in these studies required extensive manual intervention and were unsuitable for largescale fiber architectural mapping studies. We have developed an improved SALS device that allows for rapid data acquisition, automated high spatial resolution specimen positioning, and new analysis methods suitable for large-scale mapping studies. Extensive validation experiments revealed that the SALS device can accurately measure fiber orientation for up to a tissue thickness of at least 500 μm to an angular resolution of∼1^o and a spatial resolution of±254 μm. To demonstrate the new device’s capabilities, structural measurements from porcine aortic valve leaflets are presented. Results indicate that the new SALS device provides an accurate method for rapid quantification of the gross fiber structure of planar connective tissues.     

Synergistic renal protection by combining alkaline-diuresis with lipid peroxidation inhibitors in rhabdomyolysis: possible interaction between oxidant and non-oxidant mechanisms

BACKGROUND AND PURPOSE.: Heme-proteins, besides causing renal tubular obstruction, maycontribute to rhabdomyolysis-induced renal injury through aheme-iron-mediated lipid peroxidation process. In the presentstudy, we compared the combined therapy of a lipid peroxidationinhibitor, 21-aminosteroid (21-AS) and fluid-alkaline-mannitol(FAM) diuresis with either of them alone to determine the efficacyof the combination therapy and to delineate the roles of lipidperoxidation and cast formation. METHODS AND RESULTS.: Employing Raman spectroscopy, we confirmed in vitro the abilityof 21-AS to inhibit iron-induced fatty acid peroxidation. 21-ASwas then administered to rats developing renal failure fromglycerol-induced rhabdomyolysis. Although 21-AS inhibited rhabdomyolysis-inducedplasma and renal lipid peroxidation, renal protection was incomplete.Administration of FAM to inhibit cast formation afforded a betterrenal protection. However, when these therapies were combinedto inhibit both lipid peroxidation and cast formation, therewas a synergistic renal functional protection. This was accompaniedby a maximum inhibition of renal and plasma lipid peroxidation,as well as, renal tubular necrosis and cast formation. Comparedto combination therapy, FAM therapy alone, despite identicalvolume, was accompanied by a higher tubular necrosis and castformation. CONCLUSIONS.: That combining a lipid peroxidation inhibitor with fluid-alkalinediuresis in rhabdomyolysis further lowers renal lipid peroxidation,tubular necrosis and cast formation and synergistically limitsrenal dysfunction (i) supports a role for lipid peroxidationin the pathophysiology of rhabdomyolysis ARF, (ii) underscoresthe role of intratubular heme retention, a cause for tubularobstruction as well a source for prodigious amount of iron,likely involved in the lipid peroxidation, and (iii) raisesthe possibility of interactions between non-oxidant and oxidantmechanisms.