Image Analysis or Stereology

Marcos, Ricardo; Bragança, Bruno; Fontes-Sousa, Ana Patrícia

doi:10.1369/0022155415592180

Cited by 10 publications

(7 citation statements)

References 13 publications

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“…Most studies investigating penile fibrotic disorders evaluated fibrosis histopathologically using Masson's trichrome staining followed by quantitative image analysis. However, this method introduces potential biases [162][163][164] . First, and perhaps most importantly, Masson's trichrome staining is often evaluated by calculating the ratio of areas stained red to areas stained blue, assuming the red pigment stains only smooth muscle whereas the blue pigment stains only collagen.…”

Section: Limitations Of Preclinical Studiesmentioning

confidence: 99%

“…First, and perhaps most importantly, Masson's trichrome staining is often evaluated by calculating the ratio of areas stained red to areas stained blue, assuming the red pigment stains only smooth muscle whereas the blue pigment stains only collagen. However, this assumption is erroneous given that all cells contain the intermediate filament keratin -including residual red blood cells, endothelial cells and platelets in the sinusoids -and will, therefore, stain red [162][163][164] . Ideally, Masson's trichrome staining should be combined with more quantitative techniques to detect fibrosis; depending on the type of tissue, such techniques include either quantitative PCR (qPCR) or western blotting for typical profibrotic genes and proteins, respectively, such as TGFβ1, α-smooth muscle actin (αSMA), collagen (type I and III), elastin and iNOS.…”

Section: Limitations Of Preclinical Studiesmentioning

confidence: 99%

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The mechanisms and potential of stem cell therapy for penile fibrosis

2018

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| Fibrosis is often caused by chronic tissue injury leading to a persisting inflammatory response with excessive accumulation of extracellular connective tissue proteins. Peyronie's disease, urethral stricture and penile (corpora cavernosa) fibrosis are localized fibrotic disorders of the penile connective tissues that can substantially impair a patient's quality of life. Research over the past few decades has revealed the ability of stem cells to secrete a wide range of paracrine factors, a characteristic that could be exploited therapeutically to prevent and treat several inflammatory and fibrotic diseases. In preclinical studies, mesenchymal stem cells (MSCs) have proven to be the most effective and readily available type of stem cells for therapeutic use. An important advantage of MSCs is their ability to circumvent the immune system and function as immunomodulatory 'drug stores' to influence multiple cell types simultaneously. Many studies using stem cells have been applied exclusively to corpora cavernosa fibrosis owing to its well-established disease models. A plethora of preclinical data suggest the benefit of stem cells for use in penile fibrosis. However, their exact mechanism of action and optimal timing and mode of administration must be determined before clinical translation.

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Section: Limitations Of Preclinical Studiesmentioning

confidence: 99%

Section: Limitations Of Preclinical Studiesmentioning

confidence: 99%

The mechanisms and potential of stem cell therapy for penile fibrosis

2018

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“…Fifty muscle fibers per animal (3–4 rats per group) were analyzed only considering nuclei-centered cells for the analysis of cardiomyocyte dimensions. Photomicrographs of longitudinal sections of the RV stained with Picro-Sirius Red were assessed using the ImageJ software® (version 1.8.0, U.S. National Institutes of Health, MD, USA) for automated analysis of collagen content, as previously described [ 17 , 18 ]. Images were captured with a monochrome charge-coupled device camera using a 20× magnification objective.…”

Section: Methodsmentioning

confidence: 99%

“…Observations were performed and analyzed using a laser-scanning confocal microscope (Olympus Fluo View, FV1000, Tokyo, Japan). The relative amount of vimentin-positive fibroblasts per RV tissue slice was assessed using the ImageJ software® (version 1.8.0, U.S. National Institutes of Health, MD, USA) with a similar strategy to that used for collagen quantification [ 17 , 18 ]. A minimum of two separate images, captured from different (non-overlapping) regions of the RV, were obtained per tissue section using a 20× magnification objective.…”

Section: Methodsmentioning

confidence: 99%

Blockage of the adenosine A2B receptor prevents cardiac fibroblasts overgrowth in rats with pulmonary arterial hypertension

Bessa-Gonçalves

Bragança

Martins-Dias

et al. 2023

Purinergic Signalling

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Sustained pressure overload and fibrosis of the right ventricle (RV) are the leading causes of mortality in pulmonary arterial hypertension (PAH). Although the role of adenosine in PAH has been attributed to the control of pulmonary vascular tone, cardiac reserve, and inflammatory processes, the involvement of the nucleoside in RV remodelling remains poorly understood. Conflicting results exist on targeting the low-affinity adenosine A2B receptor (A2BAR) for the treatment of PAH mostly because it displays dual roles in acute vs. chronic lung diseases. Herein, we investigated the role of the A2BAR in the viability/proliferation and collagen production by cardiac fibroblasts (CFs) isolated from RVs of rats with monocrotaline (MCT)-induced PAH. CFs from MCT-treated rats display higher cell viability/proliferation capacity and overexpress A2BAR compared to the cells from healthy littermates. The enzymatically stable adenosine analogue, 5′-N-ethylcarboxamidoadenosine (NECA, 1–30 μM), concentration-dependently increased growth, and type I collagen production by CFs originated from control and PAH rats, but its effects were more prominent in cells from rats with PAH. Blockage of the A2BAR with PSB603 (100 nM), but not of the A2AAR with SCH442416 (100 nM), attenuated the proliferative effect of NECA in CFs from PAH rats. The A2AAR agonist, CGS21680 (3 and 10 nM), was virtually devoid of effect. Overall, data suggest that adenosine signalling via A2BAR may contribute to RV overgrowth secondary to PAH. Therefore, blockage of the A2AAR may be a valuable therapeutic alternative to mitigate cardiac remodelling and prevent right heart failure in PAH patients.

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“…The unstandardized and biased methodology of the LCT quantifications also spans research in other animal models, and significant differences in the mean amount of LCT can also be found in studies of healthy mice (mean amount of LCT 0% to 7%) [67][68][69][70], hamsters (mean amount of LCT 0.13% to 5%) [71,72], rabbits (mean amount of LCT 0.03% to 6.23%) [73,74] and cows (mean amount of LCT 0% to 6.17%) [75,76]. On the other hand, to date, we have found only six studies of laboratory animals that fulfill the criteria of unbiased sampling and, hence, provided us with an objective measure of the amount of LCT in healthy individuals [77][78][79][80][81][82] (Table 4). Even though we also found differences among these studies, we were not able to assess their significance due to the missing measure of variability (standard deviation or error) in most of them.…”

Section: Biased Sampling and Quantification Of Rat Liver Connective T...mentioning

confidence: 99%

Biased Quantification of Rat Liver Fibrosis—Meta-Analysis with Practical Recommendations and Clinical Implications

Mik,

Barannikava,

Surkova

2023

JCM

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For liver fibrosis assessment, the liver biopsy is usually stained with Masson’s trichrome (MT) or picrosirius red (PSR) to quantify liver connective tissue (LCT) for fibrosis scoring. However, several concerns of such semiquantitative assessments have been raised, and when searching for data on the amount of LCT in healthy rats, the results vastly differ. Regarding the ongoing reproducibility crisis in science, it is necessary to inspect the results and methods, and to design an unbiased and reproducible method of LCT assessment. We searched the Medline database using search terms related to liver fibrosis, LCT and collagen, rat strains, and staining methods. Our search identified 74 eligible rat groups in 57 studies. We found up to 170-fold differences in the amount of LCT among healthy Wistar and Sprague–Dawley rats, with significant differences even within individual studies. Biased sampling and quantification probably caused the observed differences. In addition, we also found incorrect handling of liver fibrosis scoring. Assessment of LCT using stereological sampling methods (such as systematic uniform sampling) would provide us with unbiased data. Such data could eventually be used not only for the objective assessment of liver fibrosis but also for validation of noninvasive methods of the assessment of early stages of liver fibrosis.

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Image Analysis or Stereology

Cited by 10 publications

References 13 publications

The mechanisms and potential of stem cell therapy for penile fibrosis

The mechanisms and potential of stem cell therapy for penile fibrosis

Blockage of the adenosine A2B receptor prevents cardiac fibroblasts overgrowth in rats with pulmonary arterial hypertension

Biased Quantification of Rat Liver Fibrosis—Meta-Analysis with Practical Recommendations and Clinical Implications

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