scholarly journals Combination of µCT and light microscopy for generation-specific stereological analysis of pulmonary arterial branches: a proof-of-concept study

2020 ◽  
Author(s):  
Roman Grothausmann ◽  
Jonas Labode ◽  
Pablo Hernandez-Cerdan ◽  
David Haberthür ◽  
Ruslan Hlushchuk ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Volume Fraction ◽  
Pulmonary Vasculature ◽  
Chronic Obstructive ◽  
Micro Computed Tomography ◽  
Vascular Perfusion ◽  
Arterial Tree ◽  
Color Code ◽  
Rabbit Lung ◽  
Stereological Analysis

AbstractVarious lung diseases, including pulmonary hypertension, chronic obstructive pulmonary disease or bronchopulmonary dysplasia, are associated with structural and architectural alterations of the pulmonary vasculature. The light microscopic (LM) analysis of the blood vessels is limited by the fact that it is impossible to identify which generation of the arterial tree an arterial profile within a LM microscopic section belongs to. Therefore, we established a workflow that allows for the generation-specific quantitative (stereological) analysis of pulmonary blood vessels. A whole left rabbit lung was fixed by vascular perfusion, embedded in glycol methacrylate and imaged by micro-computed tomography (µCT). The lung was then exhaustively sectioned and 20 consecutive sections were collected every 100 µm to obtain a systematic uniform random sample of the whole lung. The digital processing involved segmentation of the arterial tree, generation analysis, registration of LM sections with the µCT data as well as registration of the segmentation and the LM images. The present study demonstrates that it is feasible to identify arterial profiles according to their generation based on a generation-specific color code. Stereological analysis for the first three arterial generations of the monopodial branching of the vasculature included volume fraction, total volume, lumen-to-wall ratio and wall thickness for each arterial generation. In conclusion, the correlative image analysis of µCT and LM-based datasets is an innovative method to assess the pulmonary vasculature quantitatively.

scholarly journals Stereology and three-dimensional reconstructions to analyze the pulmonary vasculature

2021 ◽  
Author(s):  
Christian Mühlfeld
Keyword(s):  
Blood Vessels ◽  
Lung Diseases ◽  
Imaging Techniques ◽  
Research Work ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Pulmonary Vasculature ◽  
Chronic Obstructive ◽  
Micro Computed Tomography ◽  
Arterial Tree

AbstractThe pulmonary vasculature consists of a large arterial and venous tree with a vast alveolar capillary network (ACN) in between. Both conducting blood vessels and the gas-exchanging capillaries are part of important human lung diseases, including bronchopulmonary dysplasia, pulmonary hypertension and chronic obstructive pulmonary disease. Morphological tools to investigate the different parts of the pulmonary vasculature quantitatively and in three dimensions are crucial for a better understanding of the contribution of the blood vessels to the pathophysiology and effects of lung diseases. In recent years, new stereological methods and imaging techniques have expanded the analytical tool box and therefore the conclusive power of morphological analyses of the pulmonary vasculature. Three of these developments are presented and discussed in this review article, namely (1) stereological quantification of the number of capillary loops, (2) serial block-face scanning electron microscopy of the ACN and (3) labeling of branching generations in light microscopic sections based on arterial tree segmentations of micro-computed tomography data sets of whole lungs. The implementation of these approaches in research work requires expertise in lung preparation, multimodal imaging at different scales, an advanced IT infrastructure and expertise in image analysis. However, they are expected to provide important data that cannot be obtained by previously existing methodology.

scholarly journals COPD beyond proximal bronchial obstruction: phenotyping and related tools at the bedside

2019 ◽  
Vol 28 (152) ◽  
pp. 190010 ◽  
Author(s):  
Thibaut Capron ◽  
Arnaud Bourdin ◽  
Thierry Perez ◽  
Pascal Chanez
Keyword(s):  
Secretory Protein ◽  
Pulmonary Vasculature ◽  
Minor Role ◽  
Chronic Obstructive ◽  
Bronchial Obstruction ◽  
Forced Oscillation Technique ◽  
Small Airways ◽  
Micro Computed Tomography ◽  
New Paradigm ◽  
Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterised by nonreversible proximal bronchial obstruction leading to major respiratory disability. However, patient phenotypes better capture the heterogeneously reported complaints and symptoms of COPD. Recent studies provided evidence that classical bronchial obstruction does not properly reflect respiratory disability, and symptoms now form the new paradigm for assessment of disease severity and guidance of therapeutic strategies. The aim of this review was to explore pathways addressing COPD pathogenesis beyond proximal bronchial obstruction and to highlight innovative and promising tools for phenotyping and bedside assessment. Distal small airways imaging allows quantitative characterisation of emphysema and functional air trapping. Micro-computed tomography and parametric response mapping suggest small airways disease precedes emphysema destruction. Small airways can be assessed functionally using nitrogen washout, probing ventilation at conductive or acinar levels, and forced oscillation technique. These tests may better correlate with respiratory symptoms and may well capture bronchodilation effects beyond proximal obstruction.Knowledge of inflammation-based processes has not provided well-identified targets so far, and eosinophils probably play a minor role. Adaptative immunity or specific small airways secretory protein may provide new therapeutic targets. Pulmonary vasculature is involved in emphysema through capillary loss, microvascular lesions or hypoxia-induced remodelling, thereby impacting respiratory disability.

Pulmonary Hypertension Associated With Myocardial Amyloid Degeneration: a Case Report

2021 ◽  
Author(s):  
Lu Yan ◽  
Qixian Zeng ◽  
Changming Xiong ◽  
Zhihui Zhao ◽  
Qing Zhao ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Blood Vessels ◽  
Amyloid Fibrils ◽  
Right Heart Failure ◽  
Pulmonary Artery Hypertension ◽  
Pulmonary Vasculature ◽  
Vascular Involvement ◽  
Right Heart ◽  
Protein Deposits

Abstract Background: There is very little literature on Pulmonary hypertension associated with myocardial amyloid degeneration. At present, only 10 cases pulmonary hypertension cased by amyloid protein deposits in the pulmonary blood vessels have been reported by Eder et al. We reported a case that the patient was pulmonary artery hypertension combined with myocardial amyloid change. It’s aim to claims that pulmonary hypertension is most likely caused by amyloid fibrin deposition in pulmonary blood vessels.Case presentation: We report a case of a 65-year-old male patient with with AL and ATTR combined type amyloidosis who developed right heart failure because of severe pulmonary hypertension. Pulmonary hypertension due to deposition of amyloid in the pulmonary vasculature is an uncommon finding; however, it should be considered in cases of unexplained pulmonary hypertension in patients with amyloidosis.Conclusion: we present a men with amyloidosis who developed dyspnea and right heart failure and was diagnosed with pulmonary hypertension, most probably secondary to pulmonary vascular involvement by amyloid fibrils.

scholarly journals Trabecular bone patterning in the hominoid distal femur

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5156 ◽  
Author(s):  
Leoni Georgiou ◽  
Tracy L. Kivell ◽  
Dieter H. Pahr ◽  
Matthew M. Skinner
Keyword(s):  
Trabecular Bone ◽  
Distal Femur ◽  
Volume Fraction ◽  
Reaction Force ◽  
Intraspecific Variability ◽  
Trabecular Structure ◽  
Trabecular Architecture ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Distal Epiphysis

BackgroundIn addition to external bone shape and cortical bone thickness and distribution, the distribution and orientation of internal trabecular bone across individuals and species has yielded important functional information on how bone adapts in response to load. In particular, trabecular bone analysis has played a key role in studies of human and nonhuman primate locomotion and has shown that species with different locomotor repertoires display distinct trabecular architecture in various regions of the skeleton. In this study, we analyse trabecular structure throughout the distal femur of extant hominoids and test for differences due to locomotor loading regime.MethodsMicro-computed tomography scans ofHomo sapiens(n= 11),Pan troglodytes(n= 18),Gorilla gorilla(n= 14) andPongosp. (n= 7) were used to investigate trabecular structure throughout the distal epiphysis of the femur. We predicted that bone volume fraction (BV/TV) in the medial and lateral condyles inHomowould be distally concentrated and more anisotropic due to a habitual extended knee posture at the point of peak ground reaction force during bipedal locomotion, whereas great apes would show more posteriorly concentrated BV/TV and greater isotropy due to a flexed knee posture and more variable hindlimb use during locomotion.ResultsResults indicate some significant differences between taxa, with the most prominent being higher BV/TV in the posterosuperior region of the condyles inPanand higher BV/TV and anisotropy in the posteroinferior region inHomo. Furthermore, trabecular number, spacing and thickness differ significantly, mainly separatingGorillafrom the other apes.DiscussionThe trabecular architecture of the distal femur holds a functional signal linked to habitual behaviour; however, there was more similarity across taxa and greater intraspecific variability than expected. Specifically, there was a large degree of overlap in trabecular structure across the sample, andHomowas not as distinct as predicted. Nonetheless, this study offers a comparative sample of trabecular structure in the hominoid distal femur and can contribute to future studies of locomotion in extinct taxa.

scholarly journals Predictors of co-morbidities in chronic obstructive pulmonary disease patients at a tertiary care centre in north India

2019 ◽  
Vol 7 (11) ◽  
pp. 4154
Author(s):  
Kaushlendra Pratap Narayan ◽  
S. K. Verma ◽  
Surya Kant ◽  
R. A. S. Kushwaha ◽  
Santosh Kumar ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Inflammatory Process ◽  
Tertiary Care ◽  
Airflow Limitation ◽  
Pulmonary Vasculature ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Co Morbidity

Background: Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation. COPD is characterised by an intense inflammatory process in the airways, parenchyma, and pulmonary vasculature. It is possible in some cases that the inflammatory process may overflow into the systemic circulation, promoting a generalised inflammatory reaction. Patient with COPD often have concomitant chronic illness (co-morbidities). The aim of this study is to know the pattern of co-morbidities in COPD patients.Methods: This study was a cross sectional observational study conducted on 172 COPD patients (IPD and OPD) diagnosed on the basis of GOLD guideline 2017. Co morbidities were diagnosed as per standard defined criteria laid down in the respective guidelines.Results: 55.3% of the patients with COPD had co morbidities. 18/88(20.5%) patients presented with multiple co-morbidities. 49/88, 55.7% COPD patients were affected with cardiac (either only cardiac or had multiple organs affected besides cardiac), the commonest co-morbidity. Amongst cardiac, hypertension and congestive heart failure (CHF) was the commonest (n=19/49, 38.8% each) followed by CAD/CSA/IWMI/IHD/AF. Others were metabolic (n=14/88, 15.9%), GERD (n=13/88, 14.8%), Depression (n=11/88, 12.5%). Less prevalent co-morbidities were Osteoporosis (n=8/88, 9.1%), Lung cancer (n=6/88, 6.8%), Bronchiectasis (n=5/88, 5.6%) and OSA (n=3/88, 3.4%).Conclusions: Urban indwelling, advancing age and duration of illness, presentation with low mood, loss of pleasure/ interest, appetite disturbances and heart burn with relief on taking proton pump inhibitor can be predictors of co-morbidities in COPD patients. Chance of finding co-morbidities may be multifactorial. Thus, it is important to look out for co morbidities in each and every COPD patients.

Quantitative micro-computed tomography analysis and rheological investigation of Nitrile rubber/Rockwool composites

2021 ◽  
pp. 002199832110338
Author(s):  
Elisson BD da Rocha ◽  
Ana Maria F de Sousa ◽  
Ana Lúcia N da Silva ◽  
Cristina RG Furtado ◽  
Marcos V Colaço ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Elastic Modulus ◽  
Aspect Ratio ◽  
Volume Fraction ◽  
Nitrile Rubber ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Rubber Composites ◽  
Ratio Data ◽  
Ct Analysis

This study reports the reinforcement degree investigation of two types of rockwool fibers (F1 and F2), in nitrile rubber composites. The micro-computed tomography (micro-CT) 3D images showed that both fibers were well-dispersed in the NBR matrix, without a preferential orientation. The micro-CT analysis also allowed quantifying volume fraction, inter-fiber distance, and aspect ratio. Those morphometric parameters were used for supporting the composites rheological behavior assessment. Changes in the elastic modulus and phase angle followed the same trend of the inter-fiber distance values, regardless the type of fiber. Both volume fraction and aspect ratio data from the micro-CT analysis were used to predict theoretical values of elastic modulus using the Guth-Gold and modified Guth-Gold equations, and the results obtained were compared to the rheological experimental data. This analysis was helpful to better understand the rockwool fibers reinforcement degree differences in the production of the nitrile rubber composites.

Micro-computed tomography analysis of natural fiber and bio-matrix tubular-braided composites

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4003-4013 ◽  
Author(s):  
Brianna M Bruni-Bossio ◽  
Garrett W Melenka ◽  
Cagri Ayranci ◽  
Jason P Carey
Keyword(s):  
Computed Tomography ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Void Content ◽  
Micro Computed Tomography ◽  
Braided Composites ◽  
Fiber Volume ◽  
Increasing Demand ◽  
Materials Used ◽  
Curing Method

There is an increasing demand for the use of “green”-based materials as reinforcement and matrix materials in composites. However, the ability of these natural-based materials to perform as consistently and reliably as conventional materials is still relatively unknown. A key importance in the viability of these materials is the evaluation of the content of voids and imperfections, which may affect the properties of the entire composite. In this study, the microstructure of tubular-braided composites manufactured from cellulose fibers and a partially bio-derived resin was studied with the use of micro-computed tomography. These methods were used to determine the effect of modifying braid angle, resin type, and curing method on fiber volume fraction, void volume, and void distribution. It was determined that the void content increased with the increase in braid angle, and vacuum-bagging reduced the total void content. The sample with the smallest braid angle produced with vacuum-bagged curing contained a void fraction of 1.5%. The results of this study proved that the materials used could be viable for further testing and development and that micro-computed tomography imaging is valuable for identifying how to improve consistency and minimize imperfections to create more accurate and reliable natural fiber-braided composites.

scholarly journals Homogenization of cortical bone reveals that the organization and shape of pores marginally affect elasticity

2019 ◽  
Vol 16 (151) ◽  
pp. 20180911 ◽  
Author(s):  
Xiran Cai ◽  
Renald Brenner ◽  
Laura Peralta ◽  
Cécile Olivier ◽  
Pierre-Jean Gouttenoire ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Volume Fraction ◽  
Transversely Isotropic ◽  
Pore Network ◽  
Anisotropic Elasticity ◽  
Homogenization Method ◽  
Femoral Diaphysis ◽  
Micro Computed Tomography ◽  
Architectural Features ◽  
Resonant Ultrasound

With ageing and various diseases, the vascular pore volume fraction (porosity) in cortical bone increases, and the morphology of the pore network is altered. Cortical bone elasticity is known to decrease with increasing porosity, but the effect of the microstructure is largely unknown, while it has been thoroughly studied for trabecular bone. Also, popular micromechanical models have disregarded several micro-architectural features, idealizing pores as cylinders aligned with the axis of the diaphysis. The aim of this paper is to quantify the relative effects on cortical bone anisotropic elasticity of porosity and other descriptors of the pore network micro-architecture associated with pore number, size and shape. The five stiffness constants of bone assumed to be a transversely isotropic material were measured with resonant ultrasound spectroscopy in 55 specimens from the femoral diaphysis of 29 donors. The pore network, imaged with synchrotron radiation X-ray micro-computed tomography, was used to derive the pore descriptors and to build a homogenization model using the fast Fourier transform (FFT) method. The model was calibrated using experimental elasticity. A detailed analysis of the computed effective elasticity revealed in particular that porosity explains most of the variations of the five stiffness constants and that the effects of other micro-architectural features are small compared to usual experimental errors. We also have evidence that modelling the pore network as an ensemble of cylinders yields biased elasticity values compared to predictions based on the real micro-architecture. The FFT homogenization method is shown to be particularly efficient to model cortical bone.

scholarly journals Targeted ablation of the PTH/PTHrP receptor in osteocytes impairs bone structure and homeostatic calcemic responses

2011 ◽  
Vol 209 (1) ◽  
pp. 21-32 ◽  
Author(s):  
William F Powell ◽  
Kevin J Barry ◽  
Irena Tulum ◽  
Tatsuya Kobayashi ◽  
Stephen E Harris ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Bone Structure ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Blood Calcium ◽  
Low Calcium Diet ◽  
Exon 1 ◽  
Skeletal Homeostasis ◽  
Pthrp Receptor

Parathyroid hormone (PTH) is a major physiologic regulator of calcium, phosphorous, and skeletal homeostasis. Cells of the osteoblastic lineage are key targets of PTH action in bone, and recent evidence suggests that osteocytes might be important in the anabolic effects of PTH. To understand the role of PTH signaling through the PTH/PTHrP receptors (PPR) in osteocytes and to determine the role(s) of these cells in mediating the effects of the hormone, we have generated mice in which PPR expression is specifically ablated in osteocytes. Transgenic mice in which the 10 kb-Dmp1 promoter drives a tamoxifen-inducible Cre-recombinase were mated with animals in which exon 1 of PPR is flanked by lox-P sites. In these animals, osteocyte-selective PPR knockout (Ocy-PPRcKO mice) could be induced by administration of tamoxifen. Histological analysis revealed a reduction in trabecular bone and mild osteopenia in Ocy-PPRcKO mice. Reduction of trabeculae number and thickness was also detected by micro-computed tomography analysis whereas bone volume fraction (BV/TV%) was unchanged. These findings were associated with an increase in Sost and sclerostin expression. When Ocy-PPRcKO mice were subjected to a low-calcium diet to induce secondary hyperparathyroidism, their blood calcium levels were significantly lower than littermate controls. Moreover, PTH was unable to suppress Sost and sclerostin expression in the Ocy-PPRcKO animals, suggesting an important role of PTH signaling in osteocytes for proper bone remodeling and calcium homeostasis.

scholarly journals Vascular changes in the retina in patients with chronic respiratory insufficiency

2014 ◽  
Vol 71 (12) ◽  
pp. 1132-1137
Author(s):  
Antoaneta Adzic-Zecevic ◽  
Biljana Milojko ◽  
Mirjana Janicijevic-Petrovic
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Respiratory Failure ◽  
Blood Vessels ◽  
Pulmonary Disease ◽  
Bronchial Asthma ◽  
Respiratory Insufficiency ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Retinal Blood Vessels ◽  
Chronic Respiratory Insufficiency

Background/Aim. Chronic respiratory insufficiency is a pathological state which occurs as a result of respiratory system inability to maintain normal gas exchange between the outside air and circulating blood. For the purposes of human organism?s proper functioning, it is necessary that a certain amount of air in the lungs comes into contact with a certain amount of blood within a unit of time, so that an adequate hemoglobin oxygenation could be achieved. Then, hemoglobin from erythrocytes in the blood supply delivers oxygen to all the tissues and cells of the body including the eye. Direct impact of hypoxemia and hypercapnia on the wall of arterioles, venules and capillaries results in a severe vasodilatation along with the increased permeability of the walls causing clinically evident changes in the retina. The aim of this study was to determine the degree of ocular changes in retina with patients suffering from chronic respiratory insufficiency. Methods. A prospective study was conducted on 80 patients, 40 patients with respiratory failure and 40 patients with chronic obstructive pulmonary disease an and bronchial asthma (the control group). In all the patients direct and indirect ophthalmoscopy and fluoresceine angiography was performed. Clinically visible fundus and retina changes in patients suffering from chronic respiratory failure were categorized as mild (dilatation and retinal veins and arteries tortosion up to the mid-periphery), moderate (retinal hemorrhage) and severe (optic nerve edema, macular edema, superficial and deep retinal hemorrhages and venous occlusion). Results. In the patients suffering from respiratory insufficiency the changes in retinal blood vessels were found [in 18 (45%) mild, in 13 (32.5%) moderate, and in 9 (22%) severe], while in the patients with chronic obstructive pulmonary disease and bronchial asthma (without respiratory insufficiency) no changes were recognized. Conclusion. The results of this study indicate the need for ophthalmologic examination in patients with chronic respiratory insufficiency. It is important to recognize, identify and quantify the changes on retinal blood vessels which are clinically significant. It is necessary to provide their monitoring and to prescribe proper therapeutic treatment in order to preserve visual functions.

Sign in / Sign up

Export Citation Format

Share Document