scholarly journals Fractal analysis of concurrently prepared latex rubber casts of the bronchial and vascular systems of the human lung

Open Biology ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 190249
Author(s):  
Montanna Essey ◽  
John N. Maina
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Vein ◽  
Human Lung ◽  
Vascular System ◽  
Structural Complexity ◽  
Fractal Dimensions ◽  
Fractal Structures ◽  
Pulmonary Capillary Blood ◽  
Bronchial System ◽  
Latex Rubber

Fractal geometry (FG) is a branch of mathematics that instructively characterizes structural complexity. Branched structures are ubiquitous in both the physical and the biological realms. Fractility has therefore been termed nature's design. The fractal properties of the bronchial (airway) system, the pulmonary artery and the pulmonary vein of the human lung generates large respiratory surface area that is crammed in the lung. Also, it permits the inhaled air to intimately approximate the pulmonary capillary blood across a very thin blood–gas barrier through which gas exchange to occur by diffusion. Here, the bronchial (airway) and vascular systems were simultaneously cast with latex rubber. After corrosion, the bronchial and vascular system casts were physically separated and cleared to expose the branches. The morphogenetic (Weibel's) ordering method was used to categorize the branches on which the diameters and the lengths, as well as the angles of bifurcation, were measured. The fractal dimensions ( D F ) were determined by plotting the total branch measurements against the mean branch diameters on double logarithmic coordinates (axes). The diameter-determined D F values were 2.714 for the bronchial system, 2.882 for the pulmonary artery and 2.334 for the pulmonary vein while the respective values from lengths were 3.098, 3.916 and 4.041. The diameters yielded D F values that were consistent with the properties of fractal structures (i.e. self-similarity and space-filling). The data obtained here compellingly suggest that the design of the bronchial system, the pulmonary artery and the pulmonary vein of the human lung functionally comply with the Hess–Murray law or ‘the principle of minimum work’.

scholarly journals Fractal Structure and Fractal Measurement of Pulmonary Vascular Systems

2021 ◽  
Vol 07 (12) ◽  
Author(s):  
Jamoliddin Jabbarov ◽  
Keyword(s):  
Fractal Structure ◽  
Human Lung ◽  
Vascular System ◽  
Fractal Dimensions ◽  
Body Parts ◽  
Vascular Networks ◽  
Practical Application ◽  
Mathematical Methods ◽  
Mathematical Formulas ◽  
Fractal Size

This article is devoted to determining the fractal structure and fractal size of organs. There is a detailed description of the various mathematical methods for determining the size of fractal organs, and an analysis of errors in determining the fractal size of organs. In the article, the fractal structure, fractal size, properties of human organs were determined using the Mandelbrot-Richardson scale (or cell method). The fractal structure of the human lung was also studied by comparing the fractal structure of tree branches. In particular, tree branches, vascular systems in the human retina, and fractal measurements of the lungs were calculated. In determining the fractal scale, changes in human body parts were not taken into account. Most articles have used fractal measurement only in relation to geometric shapes. In this article, the fractal structure of human organisms is studied on the basis of mathematical formulas and special methods are used to calculate fractal dimensions, as well as the results of an appropriate number of experiments. In addition, based on these measurements, fractal measurements of the pulmonary vascular system of patients have been evaluated in several studies, widely used to describe vascular networks in various diseases, and data on their practical application have been provided.

scholarly journals The prevalence of pulmonary hypertension assessed using the pulmonary vein‐to‐right pulmonary artery ratio and its association with survival in West Highland white terriers with canine idiopathic pulmonary fibrosis

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Elodie Roels ◽  
Aline Fastrès ◽  
Anne-Christine Merveille ◽  
Géraldine Bolen ◽  
Erik Teske ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Pulmonary Artery ◽  
Pulmonary Vein ◽  
Survival Data ◽  
Study Objective ◽  
Time Motion ◽  
Co Morbidity ◽  
Right Pulmonary Artery

Abstract Background Pulmonary hypertension (PH) is a known co-morbidity in West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF). The pulmonary vein-to-right pulmonary artery ratio (PV/PA) has recently been described for the detection of pre-capillary PH in dogs. The objective of the present study was to estimate the prevalence of PH at diagnostic, in WHWTs affected with CIPF, by using PV/PA, in comparison with a group of healthy breed-matched controls (CTRLs). Additional study objective was to explore whether the presence of PH at initial diagnosis of CIPF impacted survival time in dogs treated with sildenafil. Results Twenty-five client-owned WHWTs presented with CIPF and 19 CTRLs were included in the study. PV/PA in either two-dimensional mode (2D) or time-motion mode or both were measured from cineloops in each dog. Dogs were classified according to PV/PA value into non/mild PH (PV/PA measured in 2D ≥ 0.7) or moderate/severe PH (PV/PA < 0.7). Survival data of WHWTs affected with CIPF were extracted from medical record to assess association between presence of PH at diagnosis and outcome. 60 % overall prevalence for moderate/severe PH was estimated in this cohort of WHWTs presented with CIPF vs. 5 % in CTRLS (P = 0.0002). The presence of moderate/severe PH at initial presentation was not associated with survival. Conclusions Results of the present study confirm a high prevalence of PH at diagnosis in WHWTs affected with CIPF and highlight the utility of PV/PA as a non-invasive surrogate for assessment of PH in this population.

Hydraulic input impedance to aorta and pulmonary artery in dogs

1963 ◽  
Vol 18 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Dali J. Patel ◽  
Flavio M. deFreitas ◽  
Donald L. Fry
Keyword(s):  
Pulmonary Artery ◽  
Physical Properties ◽  
Input Impedance ◽  
Vascular System ◽  
Electrical Networks ◽  
Pressure Flow ◽  
Logical Basis ◽  
Vascular Bed ◽  
Hydraulic Load ◽  
Complex Ratio

Pressure-flow relationships were studied at the root of the aorta and the pulmonary artery in 18 dogs. The hydraulic input impedance to the vascular bed was calculated as a complex ratio of the corresponding pressure and flow harmonics. Results indicate: a) The predominant features of the load against which the heart is pumping consists of an impedance with a magnitude that initially decreases rapidly with frequency and then increases gradually with frequency. In general, pressure tends to lag behind flow for all harmonics. b) The input impedance versus frequency patterns provided a logical basis for choosing various simple electrical networks which can be used to characterize in a compact manner the general features of the hydraulic load presented to the ventricles. c) The hazards of using such simple networks to define the physical properties of the vascular system are pointed out. Submitted on July 5, 1962 Submitted on July 30, 1962

scholarly journals Asymptomatic Pulmonary Vein Stenosis: Hemodynamic Adaptation and Successful Ablation

2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
John J. Lee ◽  
Denis Weinberg ◽  
Rishi Anand
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Artery ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
Lung Perfusion ◽  
Atrial Fibrillation Ablation ◽  
Clinical Severity ◽  
Pulmonary Vein Stenosis ◽  
Multiple Imaging ◽  
Vein Stenosis

Pulmonary vein stenosis is a well-established possible complication following an atrial fibrillation ablation of pulmonary veins. Symptoms of pulmonary vein stenosis range from asymptomatic to severe exertional dyspnea. The number of asymptomatic patients with pulmonary vein stenosis is greater than originally estimated; moreover, only about 22% of severe pulmonary vein stenosis requires intervention. We present a patient with severe postatrial fibrillation (AF) ablation pulmonary vein (PV) stenosis, which was seen on multiple imaging modalities including cardiac computed tomography (CT) angiogram, lung perfusion scan, and pulmonary angiogram. This patient did not have any pulmonary symptoms. Hemodynamic changes within a stenosed pulmonary vein might not reflect the clinical severity of the obstruction if redistribution of pulmonary artery flow occurs. Our patient had an abnormal lung perfusion and ventilation (V/Q) scan, suggesting pulmonary artery blood flow redistribution. The patient ultimately underwent safe repeat atrial fibrillation ablation with successful elimination of arrhythmia.

THE HAMMAN-RICH SYNDROME IN CHILDHOOD

PEDIATRICS ◽  
1958 ◽  
Vol 22 (2) ◽  
pp. 279-288
Author(s):  
Israel Diamond
Keyword(s):  
Pulmonary Artery ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Clinical Picture ◽  
Lung Biopsy ◽  
Progressive Dyspnea ◽  
Fibrotic Process ◽  
Persistent Cough ◽  
Right Pulmonary Artery ◽  
The Right

The Hamman-Rich syndrome is described in a 4-year-old Negro male. The clinical picture was that of persistent cough and progressive dyspnea beginning at 4 months of age. Diagnosis was made ante mortem by lung biopsy. The fibrotic process and arteriolosclerosis were more marked in the right lung. The disease may have been initiated by a bout of aspiration. There was accompanying stenosis of the right pulmonary artery and vein and occlusion of the lumen of the right pulmonary vein at its entrance to the left atrium. The hilar vascular findings are believed to be secondary to hilar areolar inflammation.

Gas Tensions in the Lungs and Major Blood Vessels of the Urodele Amphibian, Amphiuma Tridactylum

1971 ◽  
Vol 55 (1) ◽  
pp. 47-61
Author(s):  
DANIEL P. TOEWS ◽  
G. SHELTON ◽  
D. J. RANDALL
Keyword(s):  
Carbon Dioxide ◽  
Pulmonary Artery ◽  
Inferior Vena Cava ◽  
Blood Vessels ◽  
Pulmonary Vein ◽  
Oxygen Tension ◽  
Inferior Vena ◽  
Vena Cava ◽  
Dorsal Aorta ◽  
Oxygen Tensions

1. Oxygen and carbon dioxide tensions were determined in the lungs and in blood from the dorsal aorta, pulmonary vein, pulmonary artery and inferior vena cava in the intact, free swimming, Amphiuma. At 15° C this animal was submerged for a large part of the time and surfaced briefly to breathe at variable time intervals, the mean period being 45 min. 2. Oxygen tensions in the lungs and in all blood vessels oscillated with the breathing cycles, falling gradually during the period of submersion and rising rapidly after the animal breathed. The absolute level of oxygen tension did not appear to constitute the effective signal beginning or ending a series of breathing movements. 3. A small oxygen gradient existed between lungs and blood in the pulmonary vein immediately after a breath. The gradient increased in size as an animal remained submerged due, it is suggested, to lung vasoconstriction increasing the transfer factor. 4. Blood in the dorsal aorta had a lower oxygen tension than that in the pulmonary vein. A right-to-left shunt occurred as blood moved through the heart. The degree of shunting increased as the animal remained submerged and pulmonary vasoconstriction occurred. Left-to-right shunt was relatively insignificant since oxygen tensions in the inferior vena cava and pulmonary artery were very similar. 5. Carbon dioxide tensions were relatively constant during the breathing-diving cycle since Amphiuma removed almost all of this gas through the skin.

Morphogenesis of the bone marrow: fractal structures and diffusion- limited growth

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5027-5031 ◽  
Author(s):  
F Naeim ◽  
F Moatamed ◽  
M Sahimi
Keyword(s):  
Bone Marrow ◽  
Spatial Organization ◽  
Fractal Dimensions ◽  
Fractal Structures ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Morphometric Analyses ◽  
Cellular Area ◽  
Pathologic Processes

Bone marrow (BM) provides a particular spatial organization that allows interaction between its various components. Characterization of the spatial patterns in the BM and understanding the mechanisms that give rise to them may play a role in better understanding of the BM pathologic processes. Morphometric analyses were performed in BM biopsy samples from 30 patients (16 men and 14 women) with an average age of 46 years, ranging from 17 to 77 years. The biopsies were obtained during the course of patient care to rule out BM involvement in a variety of hematologic disorders before or after therapy. Three different, but structurally interrelated, parameters were measured: (A) cellular area, (B) nuclear area, and (C) cell numbers. All three methods, in all cases, showed that the spatial structure of the BM is fractal. The average values of the fractal dimensions (Df) were 1.7 +/- 0.08, 1.64 +/- 0.1, and 1.69 +/- 0.04 for categories A, B, and C, respectively. The overall value of Df for the cellularity in the range of 40% to 60% was about 1.67 +/- 0.09. Fractal dimensions of 1.6 to 1.7 represent configurations that correspond to two-dimensional diffusion limited aggregation structures, suggesting that the structural configuration of hematopoietic cells is dependent on the diffusion of regulatory cytokines in the BM.

Microvascular injury distal to unilateral pulmonary artery occlusion

1981 ◽  
Vol 51 (4) ◽  
pp. 845-851 ◽  
Author(s):  
R. L. Johnson ◽  
S. S. Cassidy ◽  
M. Haynes ◽  
R. L. Reynolds ◽  
W. Schulz
Keyword(s):  
Pulmonary Artery ◽  
Left Lung ◽  
Left Pulmonary Artery ◽  
Artery Occlusion ◽  
Diffusing Capacity ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Pulmonary Capillary Blood ◽  
Rebreathing Method ◽  
Unilateral Pulmonary Artery Occlusion

We explored three questions: 1) does edema fluid accumulate distal to temporary unilateral pulmonary artery occlusion (TUPAO); 2) if so how rapidly does it accumulate; and 3) how is it affected by positive end-expiratory pressure (PEEP)? Using a tracheal divider we measured pulmonary capillary blood flow (Qc), tissue volume (Vt), and diffusing capacity (DLCO) in each lung with a rebreathing method. After control measurements in 12 dogs, the left pulmonary artery was occluded and measurements were repeated at intervals during 4 h of occlusion and 30 min after release of the occlusion. Six of the dogs were ventilated with 10 cmH2O PEEP. Finally the lungs were removed, weighed, and fixed for histology. TUPAO caused a 29% increase in Vt of the left lung without PEEP and a 59% increase with PEEP. After release of the occlusion, Qc and DLCO in the left lung returned to control levels within 30 min in dogs not on PEEP but remained depressed in dogs ventilated with PEEP even though PEEP was removed. At postmortem the left lung weighed more than expected in both groups of dogs but was significantly heavier in those on PEEP. Histology confirmed bronchovascular cuffing with edema and hemorrhage.

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