A Quantitative Method to Determine the Orientation of Collagen Fibers in the Dermis

We have developed a quantitative microscopic method to determine changes in the orientation of collagen fibers in the dermis resulting from mechanical stress. The method is based on the use of picrosirius red-stained cryostat sections of piglet skin in which collagen fibers reflect light strongly when epipolarization microscopy is used. Digital images of sections were converted into binary images that were analyzed quantitatively on the basis of the length of the collagen fibers in the plane of the section as a measure for the orientation of the fibers. The length of the fibers was expressed in pixels and the mean length of the 10 longest fibers in the image was taken as the parameter for the orientation of the fibers. To test the procedure in an experimental setting, we used skin after 0 and 30 min of skin stretching. The orientation of the fibers in sections of control skin differed significantly from the orientation of fibers in sections of skin that was stretched mechanically for 30 min [76 ± 15 ( n = 5) vs 132 ± 36 ( n = 5)]. The method described here is a relatively simple way to determine (changes in) the orientation of individual collagen fibers in connective tissue and can also be applied for analysis of the orientation of any other structural element in tissues so long as a representative binary image can be created.

Download Full-text

Effectiveness of silver nitrate compared to talc slurry as pleural sclerosing agent in rabbits. Influence of concomitant intrapleural lidocaine

Revista do Hospital das Clínicas ◽

10.1590/s0041-87811999000600006 ◽

1999 ◽

Vol 54 (6) ◽

pp. 199-208 ◽

Cited By ~ 5

Author(s):

Francisco S. Vargas ◽

Alipio O. Carmo ◽

Evaldo Marchi ◽

Marcelo A.C. Vaz ◽

Karine P. Ramos ◽

...

Keyword(s):

Silver Nitrate ◽

Rabbit Model ◽

Collagen Fibers ◽

The Past ◽

Ideal Agent ◽

Pleural Fibrosis ◽

The Mean ◽

Picrosirius Red ◽

Better Than ◽

The Ideal

The ideal agent for producing pleurodesis has not been identified. Talc, the most commonly used, poses several problems. Another possibility is silver nitrate, which was widely used in the past. PURPOSE: To determine the influence of the intrapleural instillation of lidocaine in producing a pleurodesis with silver nitrate, to define the effect of lidocaine in the maturation of the collagen fibers, and to confirm that the pleurodesis after silver nitrate is stronger than after talc. METHODS: We studied three groups of 8 rabbits. Two groups received 0.5% silver nitrate; in one we had previously injected 0.5 ml of 2% lidocaine. The third group received 400 mg/kg talc (2 ml). The animals were sacrificed 28 days after the injection, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of inflammation and fibrosis. The total amount of pleural collagen and the distribution of thick and thin collagen fibers were quantified. Collagen was identified using picrosirius red stain. RESULTS: In the two groups that received silver nitrate (without lidocaine: 3.5 + 03 and with lidocaine: 3.2 + 0.3), the macroscopic pleurodesis (scale 0 -- 4) was significantly (p = 0.001) better than that resulting from talc (1.6 + 0.2). The mean degree of pleural fibrosis induced by silver nitrate (3.5 + 0.2) was significantly (p = 0.004) higher than that induced by talc (1.9 + 0.1). The previous instillation of lidocaine resulted in a tendency for decreased amounts of fibrosis (3.1 + 0.4). The mean amount (10³mm²) of pleural collagen was significantly (p = 0.009) greater in the rabbits that received silver nitrate (116.9 + 22.7) than in those that received talc (10.7 + 3.4). The injection of lidocaine slightly reduced the collagen (80.1 + 30.3). The distribution of collagen fibers did not differ among the groups. CONCLUSION: This rabbit model clearly confirms that intrapleural silver nitrate is more effective than talc for producing pleurodesis. The previous intrapleural instillation of lidocaine results in a decreasing trend in the amount of collagen, but does not change the effectiveness of the pleural fusion or modify the process of collagen maturation.

Download Full-text

Combination of histochemical analyses and micro-MRI reveals regional changes of the murine cervix in preparation for labor

Scientific Reports ◽

10.1038/s41598-021-84036-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Antara Chatterjee ◽

Rojan Saghian ◽

Anna Dorogin ◽

Lindsay S. Cahill ◽

John G. Sled ◽

...

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Diffusion Tensor ◽

Ex Vivo ◽

Muscle Cells ◽

Pregnant Mouse ◽

Collagen Fibers ◽

Muscular Layer ◽

Tissue Organization ◽

Picrosirius Red

AbstractThe cervix is responsible for maintaining pregnancy, and its timely remodeling is essential for the proper delivery of a baby. Cervical insufficiency, or “weakness”, may lead to preterm birth, which causes infant morbidities and mortalities worldwide. We used a mouse model of pregnancy and term labor, to examine the cervical structure by histology (Masson Trichome and Picrosirius Red staining), immunohistochemistry (Hyaluronic Acid Binding Protein/HABP), and ex-vivo MRI (T2-weighted and diffusion tensor imaging), focusing on two regions of the cervix (i.e., endocervix and ectocervix). Our results show that mouse endocervix has a higher proportion of smooth muscle cells and collagen fibers per area, with more compact tissue structure, than the ectocervix. With advanced gestation, endocervical changes, indicative of impending delivery, are manifested in fewer smooth muscle cells, expansion of the extracellular space, and lower presence of collagen fibers. MRI detected three distinctive zones in pregnant mouse endocervix: (1) inner collagenous layer, (2) middle circular muscular layer, and (3) outer longitudinal muscular layer. Diffusion MRI images detected changes in tissue organization as gestation progressed suggesting the potential application of this technique to non-invasively monitor cervical changes that precede the onset of labor in women at risk for preterm delivery.

Download Full-text

EFFECTS OF PHYSICAL TRAINING ON THE MYOCARDIUM OF FEMALE LDL KNOCKOUT OVARIECTOMIZED MICE

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-869220172306160084 ◽

2017 ◽

Vol 23 (6) ◽

pp. 441-445

Author(s):

Ledimar Brianezi ◽

Mara Rubia Marques ◽

Clever Gomes Cardoso ◽

Maria Luiza de Jesus Miranda ◽

Fernando Luiz Affonso Fonseca ◽

...

Keyword(s):

Physical Training ◽

Volume Density ◽

Collagen Fibers ◽

Nuclear Volume ◽

Control Group ◽

Cross Sectional ◽

Training Time ◽

Aerobic Activity ◽

Ovariectomized Mice ◽

The Mean

ABSTRACT Introduction: The emergence of coronary heart disease increases with menopause, physical inactivity and with dyslipidemia. It is known that physical training promotes the improvement of cardiovascular functions. Objective: The purpose of this study was to investigate the effects of aerobic physical training on the left ventricle in female LDL knockout ovariectomized mice. Methods: Thirty animals were divided into 6 groups (n=5), namely, sedentary non-ovariectomized control; sedentary ovariectomized control; trained ovariectomized control; sedentary non-ovariectomized; sedentary ovariectomized; and trained ovariectomized. We analyzed the mean nuclear volume parameters, the cross sectional area of the myocytes, the apparent density of the capillaries, interstitium, myocytes and collagen fibers. Results: The results show that for the density of the number of nuclei, the physical activity decreased to values close to the ovariectomized control group. Regarding the mean nuclear volume and the average area of myocytes, training and ovariectomy promoted the elevation of these values but hypercholesterolemia was lower. the volume density of myocytes, hypercholesterolemia showed an increase of these values as well as the training. There was no change in the volumetric density of the capillaries and the density of collagen fibers. The training caused the decrease in the density of the interstitial volume, and the hypercholesterolemia changed to a smaller one than the control group. Conclusion: We concluded that the moderate aerobic activity or the training time used in our study were not sufficient to generate significant alterations in the hypercholesterolemic group.

Download Full-text

Collagen and elastin fibers in human pulmonary alveolar walls

Journal of Applied Physiology ◽

10.1152/jappl.1988.64.4.1659 ◽

1988 ◽

Vol 64 (4) ◽

pp. 1659-1675 ◽

Cited By ~ 52

Author(s):

S. S. Sobin ◽

Y. C. Fung ◽

H. M. Tremer

Keyword(s):

Transpulmonary Pressure ◽

Collagen Fibers ◽

Capillary Blood ◽

Fiber Bundles ◽

Cube Root ◽

Inflation Pressure ◽

Frequency Distributions ◽

Normal Distributions ◽

Statistical Frequency ◽

The Mean

The morphology and morphometric data of collagen and elastin fibers in the pulmonary alveolar walls are presented. Specimens were obtained from postmortem lungs quick-frozen at specified transpulmonary pressures. Collagen was stained by silver, and elastin was stained by orcein. Photomicrographs were composed by computer. Young lungs typically show small collagen fibers that radiate from the "posts," whereas larger fiber bundles traverse the septum irrespective of capillary blood vessels. In older lungs, rings of collagen around the posts appear enlarged. Elastin bundles do not show obvious variation in pattern with age and inflation pressure. Statistical frequency distributions of the fiber width and curvature are both skewed, but the square root of the width and the cube root of the curvature have approximate normal distributions. Typically, for young lungs at transpulmonary pressure of 4 cmH2O, the mean of (width)1/2 (in micron1/2) for collagen fibers is 0.952 +/- 0.242 (SD), that of (curvature)1/3 (in micron-1/3) is 0.349 +/- 0.094. The corresponding values for elastin are 0.986 +/- 0.255 and 0.395 +/- 0.094.

Download Full-text

Morphoquantitative study of the submucous plexus (of Meissner) of the jejunum-ileum of young and old guinea pigs

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2011000100017 ◽

2011 ◽

Vol 69 (1) ◽

pp. 85-90 ◽

Cited By ~ 4

Author(s):

Marcelo César Zanesco ◽

Romeu Rodrigues de Souza

Keyword(s):

Small Intestine ◽

Guinea Pigs ◽

Age Groups ◽

Collagen Fibers ◽

Submucous Plexus ◽

The Mean ◽

Electronic Microscope

OBJECTIVE: To study the aging of submucous plexus of the small intestine (jejunum-ileum) of the guinea pigs from the quantitative, structural and ultrastructural perspective. METHOD: Chemical preparations of membrane of the jejunum-ileum of old and young animals with the use of light and electronic microscope. RESULTS: The ganglia of young animals presented between 1 and 56 neurons and the old animals presented from 1 to 30 neurons. The mean density of the ganglia by cm² in the young jejunum-ileum was of 551±36.89 and in the old one 413±11.86. The density of the neurons was 5011±291.11 neurons/cm² average in young animals and 2918±120.70 neurons/cm² in the old ones. The size of the neurons varied in both age groups. The collagen fibers in the ganglia of old animals they were condensed. Degenerated mitochondrias in the interior of the cell were frequent in the old animals. CONCLUSION: In submucous plexus of the jejunum-ileum there is a loss of 38% of the neurons with aging.

Download Full-text

MILES FORMULAE FOR BOOLEAN MODELS OBSERVED ON LATTICES

Image Analysis & Stereology ◽

10.5566/ias.v28.p77-92 ◽

2011 ◽

Vol 28 (2) ◽

pp. 77 ◽

Cited By ~ 19

Author(s):

Joachim Ohser ◽

Werner Nagel ◽

Katja Schladitz

Keyword(s):

Mean Curvature ◽

Surface Density ◽

Euler Number ◽

Volume Density ◽

Random Sets ◽

Boolean Models ◽

Intrinsic Volumes ◽

Binary Images ◽

Density Surface ◽

The Mean

The densities of the intrinsic volumes – in 3D the volume density, surface density, the density of the integral of the mean curvature and the density of the Euler number – are a very useful collection of geometric characteristics of random sets. Combining integral and digital geometry we develop a method for efficient and simultaneous calculation of the intrinsic volumes of random sets observed in binary images in arbitrary dimensions. We consider isotropic and reflection invariant Boolean models sampled on homogeneous lattices and compute the expectations of the estimators of the intrinsic volumes. It turns out that the estimator for the surface density is proved to be asymptotically unbiased and thusmultigrid convergent for Boolean models with convex grains. The asymptotic bias of the estimators for the densities of the integral of the mean curvature and of the Euler number is assessed for Boolean models of balls of random diameters. Miles formulae with corresponding correction terms are derived for the 3D case.

Download Full-text

Investigations on the execution and evaluation of the Pummel test for polyvinyl butyral based interlayers

Glass Structures & Engineering ◽

10.1007/s40940-020-00120-y ◽

2020 ◽

Vol 5 (3) ◽

pp. 371-396

Author(s):

Miriam Schuster ◽

Jens Schneider ◽

Tuong An Nguyen

Keyword(s):

Film Surface ◽

Polyvinyl Butyral ◽

Test Method ◽

Structural Element ◽

Binary Images ◽

Free Film ◽

Safety Glass ◽

High Adhesion ◽

Adhesion Level ◽

Pull Tests

Abstract Laminated safety glass (LSG) is increasingly used as structural element in buildings. Of central importance for safety are the adhesion and the residual load-bearing capacity in the post fractured state. In literature a large number of tests to assess adhesion is mentioned. These include, e.g. peel tests, through-cracked-tensile/-bending tests, VW-pull tests and compressive shear tests. However, especially in industry, the Pummel test is widespread for determining the quality of adhesion in LSG with polyvinyl butyral based interlayers. This test method proves to be simple and quick to carry out: The laminate is stored at − 18 °C and then completely destroyed at room temperature with hammer blows. The adhesion level (0–10) is determined by visually comparing the adhering glass fragments with reference pictures or with the help of diagrams and tables which indicate the Pummel value as a function of the free film surface. Pummel value 0 is to be interpreted as no adhesion and Pummel value 10 as very high adhesion. Due to the lack of standardization, the execution and evaluation is very much dependent on the test institution and executive person. This paper shows different Pummel classifications that can currently be found on the market. Subsequently, approaches to the automatization and standardization of the execution and especially the evaluation of the Pummel test are shown. Three image evaluation methods in Matlab are presented, discussed and compared: (1) analysis of binary images, (2) statistical evaluation of the greyscale images and (3) texture analysis using co-occurrence matrices.

Download Full-text

On the Symmetry of the Bone Structure Density over the Nasopalatine Foramen via Accurate Fractal Dimension Analysis

Symmetry ◽

10.3390/sym11020202 ◽

2019 ◽

Vol 11 (2) ◽

pp. 202 ◽

Cited By ~ 3

Author(s):

Michael Bornstein ◽

Manuel Fernández-Martínez ◽

Juan Guirao ◽

Francisco Gómez-García ◽

Yolanda Guerrero-Sánchez ◽

...

Keyword(s):

Fractal Dimension ◽

Bone Structure ◽

Treatment Needs ◽

Anthropometric Measures ◽

Binary Images ◽

Anterior Nasal Spine ◽

Dimension Analysis ◽

Fractal Dimension Analysis ◽

The Mean ◽

Structure Density

The objective of the present paper is to describe all the anatomical considerations surrounding the nasopalatine foramen by relating them to the study of bone structure density via an accurate fractal dimension analysis in that area. We consecutively selected a sample of 130 patients, all of them with cone beam computed tomography (CBCT) images performed for treatment needs. We chose a specific window (ROI), which coincides with an axial cut at the level of the anterior nasal spine. Different anthropometric measurements were analyzed and a novel fractal dimension analysis was performed. Our sample consisted of 130 patients and was divided into two groups: group one (consisting of 65 subjects without loss of teeth) and group two (consisting of 65 patients with the absence of some teeth). In the sample, 52.31% were women (68 people). Mann–Whitney tests were applied to obtain the statistical results. The mean age of the patients in that sample was 53 . 67 years with a standard deviation of 8 . 20 years. We conclude that fractal dimension, a mathematical invariant, behaves symmetrically for binary images from the CBCT scanners of each subject of our sample of study. We also conclude that there were no significant differences between all the anthropometric measures used neither in the subjects themselves nor in the different groups. Therefore, some patterns of symmetry were appreciated at a complete range of levels.

Download Full-text

Estimation of Structural Reliability Under Random Fatigue Conditions

9th Biennial Conference on Reliability, Stress Analysis, and Failure Prevention ◽

10.1115/detc1991-0007 ◽

1991 ◽

Author(s):

J. D. Baldwin ◽

J. G. Thacker ◽

T. T. Baber

Keyword(s):

Standard Deviation ◽

Structural Reliability ◽

Endurance Limit ◽

Narrow Band ◽

Fatigue Behavior ◽

Fatigue Reliability ◽

Structural Element ◽

Gaussian Random Process ◽

The Mean ◽

Random Fatigue

Abstract A procedure for determining the reliability of a structural element or machine part is presented. The solution assumes that the stress history in the part can be described by a narrow band, stationary, Gaussian random process and that the fatigue behavior of the part is governed by the classical S-N curve. Endurance limit modifications are discussed and a procedure is presented for determining the mean and standard deviation of the static stresses acting throughout a structure. A numerical example is presented showing the method applied to estimate the fatigue reliability of a power wheelchair frame.

Download Full-text

Polynomial relation between mean shoot area and mean shoot weight for vigour calculation on cv. Touriga Nacional

OENO One ◽

10.20870/oeno-one.2012.46.4.1526 ◽

2012 ◽

Vol 46 (4) ◽

pp. 275

Author(s):

Paula Cristina Oliveira ◽

Joao Paulo Moura ◽

Maria José Correia ◽

Luis Filipe Sanches Fernandes ◽

Ana Alexandra Oliveira

Keyword(s):

Image Processing ◽

Digital Image Processing ◽

Digital Image ◽

Digital Photography ◽

Reliable Estimate ◽

Binary Images ◽

Rgb Images ◽

The Mean ◽

Shoot Weight ◽

Number Of Shoots

Aim: To develop a new methodology for determining vine vigour based on a polynomial relation between mean shoot area and mean shoot weight.Methods and results: Thirty grapevines (cv. Touriga Nacional) characterized by low, medium and high vigour were selected for a threeyear study. Vine vigour was determined each year by using the traditional “mean shoot weight” methodology. At the same time, the mean shoot area of each vine was determined by using digital image processing, where RGB images (Red Green Blue) were converted to HSV images (Hue Saturation Value) and then to binary images based on the saturation values with a threshold set to 0.15. Finally, we established a polynomial relation between mean shoot area and mean shoot weight, given by the equation f(x) = 0.0047x2 + 0.2254x + 0.0474, where f(x) corresponds to the mean shoot weight (vine vigour estimation) and x corresponds to the mean shoot area.Conclusions: The proposed method for calculating vine vigour based on a digital image of a vine and a polynomial relation between mean shoot area and mean shoot weight provides a highly reliable estimate of the actual vigour. Correlation for the 30 grapevines with three-year average of 99.8%.Significance and impact of the study: With this new methodology, it is unnecessary to determine the pruning weight and the number of shoots per plant in the vineyard. Its implementation is simple, based on a digital photography of the vine under study, and independent of the plot pruning date.

Download Full-text