A novel quantitative approach for eliminating sample-to-sample variation using a hue saturation value analysis program

An algorithm-based technique for counting mitochondria in cells using immunohistochemical staining of formalin-fixed and paraffin-embedded sections

PURPOSE

Visualizing mitochondria in cancer cells from human pathological specimens may improve our understanding of cancer biology. However, using immunohistochemistry to evaluate mitochondria remains difficult because almost all cells contain mitochondria and the number of mitochondria per cell may have important effects on mitochondrial function. Herein, we established an objective system (Mito-score) for evaluating mitochondria using machine-based processing of hue, saturation, and value color spaces.

METHODS

The Mito-score was defined as the number of COX4 (mitochondrial inner membrane) immunohistochemistry-positive pixels divided by the number of nuclei per cell. The system was validated using four lung cancer cell lines, normal tissues, and lung cancer tissues (199 cases).

RESULTS

The Mito-score correlated with MitoTracker, a fluorescent dye used to selectively label and visualize mitochondria within cells under a microscope (R2 = 0.68) and with the number of mitochondria counted using electron microscopy (R2 = 0.79). Histologically, the Mito-score of small cell carcinoma (57.25) was significantly lower than that of adenocarcinoma (147.5, p < 0.0001), squamous cell carcinoma (120.6, p = 0.0004), and large cell neuroendocrine carcinoma (111.8, p = 0.002).

CONCLUSION

The Mito-score method enables the analysis of the mitochondrial status of human formalin-fixed paraffin-embedded specimens and may provide insights into the metabolic status of cancer.

Quantification of solution-free red blood cell staining by sorption kinetics of Romanowsky stains to agarose gels

The imaging and quantification of stained red blood cells (RBCs) are important for identifying RBCs in hematology and for diagnosing diseased RBCs or parasites in cytopathology. Romanowsky staining has been used traditionally to produce hues in blood cells using a mixture of anionic eosin Y and cationic methylene blue and azure B. While Romanowsky stains have been widely used in cytopathology, end-users have experienced problems with varying results in staining due to the premature precipitation or evaporation of methanol, leading to the inherent inconsistency of solution-based Romanowsky staining. Herein, we demonstrate that the staining and destaining of blood smears are controllable by the contact time of agarose gel stamps. While the extent of staining and destaining is discernable by the hue values of stamped red blood cells in micrographs, the quantification of adsorbed and desorbed Romanowsky dye molecules (in particular, eosin Y, methylene blue and azure B) from and to the agarose gel stamps needs a model that can explain the sorption process. We found predictable sorption of the Romanowsky dye molecules from the pseudo-second-order kinetic model for adsorption and the one phase decay model for desorption. Thus, the method of agarose gel stamping demonstrated here could be an alternative to solution-based Romanowsky staining with the predictable quantity of sorption and timing of contact.

Divergent Forms of Pyroplastic: Lessons Learned from the M/V X-Press Pearl Ship Fire

In late May 2021, the M/V X-Press Pearl container ship caught fire while anchored 18 km off the coast of Colombo, Sri Lanka and spilled upward of 70 billion pieces of plastic or "nurdles" (∼1680 tons), littering the country's coastline. Exposure to combustion, heat, chemicals, and petroleum products led to an apparent continuum of changes from no obvious effects to pieces consistent with previous reports of melted and burned plastic (pyroplastic) found on beaches. At the middle of this continuum, nurdles were discolored but appeared to retain their prefire morphology, resembling nurdles that had been weathered in the environment. We performed a detailed investigation of the physical and surface properties of discolored nurdles collected on a beach 5 days after the ship caught fire and within 24 h of their arrival onshore. The color was the most striking trait of the plastic: white for nurdles with minimal alteration from the accident, orange for nurdles containing antioxidant degradation products formed by exposure to heat, and gray for partially combusted nurdles. Our color analyses indicate that this fraction of the plastic released from the ship was not a continuum but instead diverged into distinct groups. Fire left the gray nurdles scorched, with entrained particles and pools of melted plastic, and covered in soot, representing partial pyroplastics, a new subtype of pyroplastic. Cross sections showed that the heat- and fire-induced changes were superficial, leaving the surfaces more hydrophilic but the interior relatively untouched. These results provide timely and actionable information to responders to reevaluate cleanup end points, monitor the recurrence of these spilled nurdles, gauge short- and long-term effects of the spilled nurdles to the local ecosystem, and manage the recovery of the spill. These findings underscore partially combusted plastic (pyroplastic) as a type of plastic pollution that has yet to be fully explored despite the frequency at which plastic is burned globally.

Digital Image Analysis of Picrosirius Red Staining: A Robust Method for Multi-Organ Fibrosis Quantification and Characterization

Current understanding of fibrosis remains incomplete despite the increasing burden of related diseases. Preclinical models are used to dissect the pathogenesis and dynamics of fibrosis, and to evaluate anti-fibrotic therapies. These studies require objective and accurate measurements of fibrosis. Existing histological quantification methods are operator-dependent, organ-specific, and/or need advanced equipment. Therefore, we developed a robust, minimally operator-dependent, and tissue-transposable digital method for fibrosis quantification. The proposed method involves a novel algorithm for more specific and more sensitive detection of collagen fibers stained by picrosirius red (PSR), a computer-assisted segmentation of histological structures, and a new automated morphological classification of fibers according to their compactness. The new algorithm proved more accurate than classical filtering using principal color component (red-green-blue; RGB) for PSR detection. We applied this new method on established mouse models of liver, lung, and kidney fibrosis and demonstrated its validity by evidencing topological collagen accumulation in relevant histological compartments. Our data also showed an overall accumulation of compact fibers concomitant with worsening fibrosis and evidenced topological changes in fiber compactness proper to each model. In conclusion, we describe here a robust digital method for fibrosis analysis allowing accurate quantification, pattern recognition, and multi-organ comparisons useful to understand fibrosis dynamics.

Comparative evaluation of aflatoxin and mineral binding activity of molecular imprinted polymer designed for dummy template using in vitro and in vivo models

The amelioration of aflatoxicosis in ducklings was examined by feeding molecular imprinted polymer (MIP) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule [5, 7-dimethoxycoumarin (DMC)] as a smart and novel toxin binder in comparison to a commercial toxin binder (CTB). MIP was characterized with some techniques, such as scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) that showed morphology and thermal resistance of MIP, respectively. The SEM showed that more pores and big cavities were formed in the network of the MIP. TGA plots of MIP showed dehydration at temperatures of about 31 °C-200 °C and gradual decomposition until 300 °C. The in vitro and in vivo ability of MIP and CTB to adsorb some minerals (Ca, Cu, Mg, P and Zn) was evaluated. The in vivo efficacy of MIP as an aflatoxins (AFs) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 d of age was also compared to that of the CTB. A total of 240 4-d-old ducklings were assigned to experimental diets. Each diet was replicated four times with 10 birds in each pen, and the initial body weight classes were considered as blocks. The experimental treatment diets included: 1- Control (basal diet without any additive or AFs), 2- MIP (5 g/kg diet), 3- CTB (5 g/kg diet), 4- AFs (0.2 mg/kg diet), 5- AFs + MIP (0.2 mg/kg + 5 g/kg diet), and 6- AFs + CTB (0.2 mg/kg + 5 g/kg diet). In vitro study may clearly reflect the possibility of adsorbing minerals by CTB as compared to MIP whilst the results were not confirmed by in vivo study and it seems that reduction in plasma levels of minerals is related to the adverse effects of AFs. Livers showed histopathological alterations, with bile-duct proliferation of all aflatoxin fed ducklings. Macroscopic study indicated liver of birds fed diets containing AFs showed abnormal signs including yellowish, friable and rounded shape without protective effect of MIP and CTB. The results obtained from in vivo study indicate the partial alleviation of the adverse effects of AFs in ducklings by dietary supplementation of MIP and CTB (5 g/kg) on plasma albumin, Zn, Mg and Ca.

Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques

Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification areas. We also show that calcification morphology and the plaque's collagen content-two determinants of atherosclerotic plaque stability-are interlinked.

Quantitative assessment of myocardial fibrosis in an age-related rat model by ex vivo late gadolinium enhancement magnetic resonance imaging with histopathological correlation

Late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) imaging can detect the presence of myocardial infarction from ischemic cardiomyopathies (ICM). However, it is more challenging to detect diffuse myocardial fibrosis from non-ischemic cardiomyopathy (NICM) with this technique due to more subtle and heterogeneous enhancement of the myocardium. This study investigates whether high-resolution LGE CMR can detect age-related myocardial fibrosis using quantitative texture analysis with histological validation. LGE CMR of twenty-four rat hearts (twelve 6-week-old and twelve 2-year-old) was performed using a 7T MRI scanner. Picrosirius red was used as the histopathology reference for collagen staining. Fibrosis in the myocardium was quantified with standard deviation (SD) threshold methods from the LGE CMR images and 3D contrast texture maps that were computed from gray level co-occurrence matrix of the CMR images. There was a significant increase of collagen fibers in the aged compared to the young rat histology slices (2.60±0.27 %LV vs. 1.24±0.29 %LV, p<0.01). Both LGE CMR and texture images showed a significant increase of myocardial fibrosis in the elderly compared to the young rats. Fibrosis in the LGE CMR images correlated strongly with histology with the 3 SD threshold (r=0.84, y=0.99x+0.00). Similarly, fibrosis in the contrast texture maps correlated with the histology using the 4 SD threshold (r=0.89, y=1.01x+0.00). High resolution ex-vivo LGE CMR can detect the presence of diffuse fibrosis that naturally developed in elderly rat hearts. Our results suggest that texture analysis may improve the assessment of myocardial fibrosis in LGE CMR images.

Angiopoietin Like Protein 2 (ANGPTL2) Promotes Adipose Tissue Macrophage and T lymphocyte Accumulation and Leads to Insulin Resistance

OBJECTIVES

Angiopoietin-like protein 2 (ANGPTL2), a recently identified pro-inflammatory cytokine, is mainly secreted from the adipose tissue. This study aimed to explore the role of ANGPTL2 in adipose tissue inflammation and macrophage activation in a mouse model of diabetes.

METHODOLOGY/PRINCIPAL FINDINGS

Adenovirus mediated lacZ (Ad-LacZ) or human ANGPTL2 (Ad-ANGPTL2) was delivered via tail vein in diabetic db/db mice. Ad-ANGPTL2 treatment for 2 weeks impaired both glucose tolerance and insulin sensitivity as compared to Ad-LacZ treatment. Ad-ANGPTL2 treatment significantly induced pro-inflammatory gene expression in white adipose tissue. We also isolated stromal vascular fraction from epididymal fat pad and analyzed adipose tissue macrophage and T lymphocyte populations by flow cytometry. Ad-ANGPTL2 treated mice had more adipose tissue macrophages (F4/80+CD11b+) and a larger M1 macrophage subpopulation (F4/80+CD11b+CD11c+). Moreover, Ad-ANGPTL2 treatment increased a CD8-positive T cell population in adipose tissue, which preceded increased macrophage accumulation. Consistent with our in vivo results, recombinant human ANGPTL2 protein treatment increased mRNA levels of pro-inflammatory gene products and production of TNF-α protein in the human macrophage-like cell line THP-1. Furthermore, Ad-ANGPTL2 treatment induced lipid accumulation and increased fatty acid synthesis, lipid metabolism related gene expression in mouse liver.

CONCLUSION

ANGPTL2 treatment promotes macrophage accumulation and activation. These results suggest potential mechanisms for insulin resistance.