Growth rate of perivascular cuffs in liquid-inflated dog lung lobes

1986 ◽  
Vol 61 (2) ◽  
pp. 647-653 ◽  
Author(s):  
R. L. Conhaim
Keyword(s):  
Cross Sections ◽  
Time Course ◽  
Inflation Pressure ◽  
Cuff Volume ◽  
Edema Formation ◽  
Lung Capacity ◽  
A Value ◽  
Liquid Storage ◽  
Additional Lobes ◽  
Lung Lobes

In the early stages of pulmonary edema, excess liquid leaving the pulmonary exchange vessels accumulates in the peribronchovascular interstitium where it forms large peribronchovascular cuffs. The peribronchovascular interstitium therefore acts as a reservoir to protect the air spaces from alveolar flooding. The rate of liquid accumulation and the liquid storage capacity of the cuffs determine how quickly alveolar flooding is likely to follow once edema formation has begun. To measure the rate and capacity of interstitial filling we inflated 11 isolated degassed dog lung lobes with liquid to an inflation pressure of 14 cmH2O (total lung capacity) for 1–300 min, then froze the lobes in liquid N2. We made photographs of 20 randomly selected 12 X 8-mm cross sections from each lobe and measured cuff volume from the photographs by point-counting. We found that cuff volume increased from 2.2% of air-space volume after 1 min of inflation to 9.3% after 300 min. To measure the driving pressure responsible for cuff formation we used micropipettes to measure subpleural interstitial liquid pressure at the hilum of three additional lobes. With liquid inflation pressure set to 14 cmH2O interstitial pressure rose exponentially to 11.5 cmH2O. Interstitial compliance calculated from our volume and pressure measurements equaled 0.09 ml X cmH2O–1 X g wet wt-1, a value similar to that measured in air-inflated lungs. Goldberg [Am. J. Physiol. 239 (Heart Circ. Physiol. 8): H189-H198, 1980] has likened interstitial filling to the charging of a capacitor, a process that follows a monoexponential time course.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of lung inflation on alveolar-airway barrier protein permeability in dog lung

1983 ◽  
Vol 55 (4) ◽  
pp. 1249-1256 ◽  
Author(s):  
R. L. Conhaim ◽  
M. A. Gropper ◽  
N. C. Staub
Keyword(s):  
Evans Blue ◽  
Protein Concentration ◽  
Blue Dye ◽  
Cuff Volume ◽  
Lung Volumes ◽  
Lung Inflation ◽  
Evans Blue Dye ◽  
Liquid Storage ◽  
Lung Expansion ◽  
Lung Lobes

To determine the leakiness to protein of the barrier that separates the air space and interstitial compartment of the lung, we measured perivascular interstitial fluid cuff protein concentration and volume in 10 isolated and 9 intact closed-chest dog lung lobes, which we degassed and inflated to 25, 50, 75, or 100% of capacity with 5% bovine serum albumin labeled with Evans blue dye. After 1 h we froze the lobes in liquid N2 and made color transparencies of 20 randomly selected frozen samples of each lobe. We measured Evans blue dye-albumin concentrations from absorption by cuff images of a 50-micron-diam red (lambda = 620 nm) microspot. We measured absolute cuff volume (ml/g dry lung) by point counting on the transparencies. Using specific Evans blue-albumin fluorescence we determined that the dye was protein bound in airways and cuffs. Cuff protein concentration averaged 37% of instillate concentration and did not vary with inflation volume or between isolated and intact lobes. Cuff volume was 3.4 ml/g dry lung at total lung capacity in both isolated and intact lobes. We conclude that at some point the barrier is permeable to albumin as well as liquid at all lung volumes in dogs and that the protein sieving properties of the barrier do not change with lung expansion over the range examined. The liquid storage capacity of the cuffs can increase as much as 20-fold between low and high lung volumes.

Sequence of perivascular liquid accumulation in liquid-inflated dog lung lobes

1986 ◽  
Vol 60 (2) ◽  
pp. 513-520 ◽  
Author(s):  
R. L. Conhaim ◽  
S. J. Lai-Fook ◽  
N. C. Staub
Keyword(s):  
Time Course ◽  
Total Lung Capacity ◽  
Maximum Size ◽  
Potential Space ◽  
Interstitial Flow ◽  
Lung Capacity ◽  
Vessel Area ◽  
Maximum Value ◽  
Arteries And Veins ◽  
Lung Lobes

The peribronchovascular interstitium of the lung is a potential space that expands in pulmonary edema with the formation of large liquid cuffs. To study the time course of cuff formation we inflated nine isolated dog lung lobes with liquid to total lung capacity, rapidly froze them in liquid N2 after inflation periods of 1–300 min, then photographed 20 blocks of each lobe at X3 magnification. From the photographs we measured the ratio of cuff area to vessel area for arteries and veins of 0.05–8 mm diam. We found that the cuff-to-vessel area ratio attained a maximum value of 3–4, which was independent of vessel size. However, the first cuffs to reach maximum size were those around vessels of 0.1–0.5 mm diam, whereas cuffs around larger vessels filled more slowly. No cuffs were visible around vessels smaller than 0.1 mm diam. After 45 min cuffs had formed around 99% of all vessels larger than 0.5 mm diam but had formed around only 38% of veins and 91% of arteries of smaller diameter. We simulated the observed rate and pattern of cuff growth using electrical analog models. The filling pattern and model analyses suggest that liquid entered the interstitium from an air space site associated with arteries of approximately 0.1–1.0 mm diam, spread to adjacent sites, and eventually reached the lobe hilum. The estimated perivascular interstitial flow resistance decreased approximately 100-fold with cuff expansion.

Reduction of paw edema and liver oxidative stress in carrageenan-induced acute inflammation by Lobaria pulmonaria and Parmelia caperata, lichen species, in mice

2019 ◽  
pp. 1-9
Author(s):  
Samira Salem ◽  
Essaid Leghouchi ◽  
Rachid Soulimani ◽  
Jaouad Bouayed
Keyword(s):  
Time Course ◽  
Acute Inflammation ◽  
Lichen Species ◽  
Paw Edema ◽  
Sod Activity ◽  
Edema Formation ◽  
Lobaria Pulmonaria ◽  
Anti Inflammatory ◽  
Endogenous Antioxidant ◽  
Inflammatory Effect

Abstract. Paw edema volume reduction is a useful marker in determining the anti-inflammatory effect of drugs and plant extracts in carrageenan-induced acute inflammation. In this study, the anti-inflammatory effect of Lobaria pulmonaria (LP) and Parmelia caperata (PC), two lichen species, was examined in carrageenan-induced mouse paw edema test. Compared to the controls in carrageenan-induced inflammation (n = 5/group), our results showed that pretreatment by single oral doses with PC extract (50–500 mg/kg) gives better results than LP extract (50–500 mg/kg) in terms of anti-edematous activity, as after 4 h of carrageenan subplantar injection, paw edema formation was inhibited at 82–99% by PC while at 35–49% by LP. The higher anti-inflammatory effect of PC, at all doses, was also observed on the time-course of carrageenan-induced paw edema, displaying profile closely similar to that obtained with diclofenac (25 mg/kg), an anti-inflammatory drug reference (all p < 0.001). Both LP and PC, at all doses, significantly ameliorated liver catalase (CAT) activity (all p < 0.05). However, superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity and glutathione (GSH) levels were found increased in liver of PC- compared to LP-carrageenan-injected mice. Our findings demonstrated on one hand higher preventive effects of PC compared to LP in a mouse carrageenan-induced inflammatory model and suggested, on the other hand, that anti-inflammatory effects elicited by the two lichens were closely associated with the amelioration in the endogenous antioxidant status of liver.

Mechanisms leading to lung edema in pulmonary embolization

1960 ◽  
Vol 198 (3) ◽  
pp. 543-546 ◽  
Author(s):  
S. A. Kabins ◽  
J. Fridman ◽  
J. Neustadt ◽  
G. Espinosa ◽  
L. N. Katz
Keyword(s):  
Pulmonary Edema ◽  
Capillary Permeability ◽  
Lysergic Acid ◽  
Lung Edema ◽  
Pulmonary Infarction ◽  
Edema Formation ◽  
Lung Lobe ◽  
Pulmonary Embolization ◽  
Sympathetic Nervous ◽  
Lung Lobes

A localized pulmonary infarction was produced by injecting a starch suspension into the pulmonary artery wedge position of one lung lobe in pentobarbitalized dogs, and the effect of three so-called antiserotonins on the ensuing pulmonary edema was determined. Edema was inhibited in the nonembolized lung lobes in 88% of the B.A.S. (1-benzyl-2-methyl-5-methoxytryptamine HCl), 45% of the DHE (dihydroergotamine), and 12% of the BOL (2-brom- d-lysergic acid diethylamide) dogs. Reasons are given for assuming that the actions of B.A.S. and DHE are due to their antiadrenergic rather than to any antiserotonin properties which they may have. Serotonin, therefore, at most has a slight role in the pulmonary edema formation caused by starch emboli. It is postulated that the emboli by producing an infarct and setting up a reflex mediated through the sympathetic nervous system, cause the release in turn of catecholamines and of histamine, the latter being immediately responsible for the capillary permeability change leading to pulmonary edema.

Interaction of inhaled LTC4 with histamine and PGD2 on airway caliber in asthma

1989 ◽  
Vol 66 (1) ◽  
pp. 304-312 ◽  
Author(s):  
G. D. Phillips ◽  
S. T. Holgate
Keyword(s):  
Time Course ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Forced Expiratory Volume ◽  
Maximal Flow ◽  
Lung Capacity ◽  
Airway Caliber ◽  
Relevant Interaction

To investigate possible mediator interaction in asthma, the effect of inhaled leukotriene (LT) C4 on bronchoconstriction provoked by histamine and prostaglandin (PG) D2 was studied in nine asthmatic subjects. The provocation doses of histamine, PGD2, and LTC4 required to produce a 12.5% decrease in baseline forced expiratory volume in 1 s (FEV1, PD12.5) and to further this fall to 25% (PD25–12.5) were determined. On three subsequent occasions, subjects inhaled either the PD12.5 LTC4 plus vehicle or vehicle plus the PD25–12.5 of either histamine or PGD2, and FEV1 and maximal flow at 70% of vital capacity below total lung capacity after a forced partial expiratory maneuver (Vp30) followed for 45 min. From these results, predicted time-course curves for LTC4 with histamine and LTC4 with PGD2 were calculated. On two final occasions, airway caliber was followed for 45 min after inhalation of the PD12.5 LTC4 followed by the PD25–12.5 of either histamine or PGD2. During the first 9 min after LTC4-histamine and LTC4-PGD2, the decreases in airway caliber were greater than the calculated predicted response. This interaction, although small, was significant with LTC4-PGD2 for both FEV1 (P = 0.01) and Vp30 (P less than 0.05) and with LTC4-histamine for Vp30 (P less than 0.05) but not for FEV1 (P less than 0.05). We conclude that inhaled LTC4 interacts synergistically with histamine and PGD2 and that this effect, although small, may be a relevant interaction in asthma.

Neuromuscular regeneration by buccal motoneuron B15 after peripheral nerve crush in Aplysia californica

1994 ◽  
Vol 72 (4) ◽  
pp. 1897-1910 ◽  
Author(s):  
T. L. Ross ◽  
C. K. Govind ◽  
M. D. Kirk
Keyword(s):  
Cross Sections ◽  
Time Course ◽  
Light And Electron Microscopy ◽  
Distal Stump ◽  
Nerve Crush ◽  
Neuromuscular Synapses ◽  
Electrophysiological Recordings ◽  
Cellular Debris ◽  
Proximal Stump ◽  
Ultrathin Sections

1. We studied regeneration of neuromuscular connections by identified buccal motoneuron B15 after axotomy produced by crushing nerve 4; the intact contralateral nerve 4 served as control. Electrophysiological recordings, intracellular dye injections, and light and electron microscopy were used to characterize the nature and time course of neuromuscular reinnervation as well as the fate of the isolated distal stump of the motor axon. 2. Axonal outgrowth or sprouting in the form of numerous “regenerites” occurred from the proximal stump of the transected B15 axon, and these regenerites projected through the crush site along the length of the nerve to innervate target muscles at the periphery. 3. Reinnervation of one of the target muscles, the accessory radula closer (I5), was first detected 3 wk after nerve crush. Neuromuscular excitatory postsynaptic potentials measured in individual I5 muscle fibers were initially small and approached control amplitudes by 8 wk postlesion. Newly regenerated neuromuscular synapses displayed facilitation and depression to repeated B15 stimulation with properties similar to those of control synapses, even at early times postlesion. 4. Reinnervation of other buccal muscles by B15, such as I4, appeared slightly delayed relative to that observed for I5. No evidence of abnormal or enlarged fields of innervation were observed, and as in control preparations, regenerated neuromuscular connections were strictly limited to muscles ipsilateral to the B15 cell body. 5. Physiological evidence suggested that the distal axon stumps of B15, although isolated from their cell bodies, survive for several weeks after axotomy. In addition, several large axon profiles indicative of motor axons were seen in cross-sections of nerve 4 taken close to the muscle and distal to the crush site, indicating survival of distal axon stumps. 6. When B15 was selectively stimulated, the newly formed regenerites failed to fire the distal axon stump of B15, demonstrating that the regenerites do not reinnervate the distal stump. 7. Degeneration of axons in nerve 4 distal to the crush site was observed in cross-sections of the nerve at 8 wk postlesion; using ultrathin sections we found cellular debris in individual axon profiles as well as large acellular masses within nerve 4, the latter likely representing the concretion of many axons. Additional evidence for such degenerative changes appeared in the form of autofluorescing spherical bodies or “spheroids” both in individual axons and the nerve distal to the crush site.(ABSTRACT TRUNCATED AT 400 WORDS)

Sequence of interstitial liquid accumulation in liquid-inflated sheep lung lobes

1989 ◽  
Vol 66 (6) ◽  
pp. 2659-2666 ◽  
Author(s):  
R. L. Conhaim ◽  
S. J. Lai-Fook ◽  
A. Eaton
Keyword(s):  
Species Differences ◽  
Lung Parenchyma ◽  
Cuff Volume ◽  
Analogue Model ◽  
Maximum Value ◽  
Cuff Size ◽  
Mechanical Linkage ◽  
Perivascular Cuff ◽  
Lung Lobes ◽  
Space Volume

In the initial stages of pulmonary edema, liquid accumulates in the lung interstitium and appears as cuffs around pulmonary vessels. To determine the pattern, rate, and magnitude of cuff formation, we inflated sheep lungs to capacity with liquid (inflation pressure 19 cmH2O) for 3–300 min. After freezing the lobes in liquid N2, we measured perivascular cuff size and total perivascular volume in frozen blocks of each lobe and compared the results with previous measurements in dog lungs. Total cuff volume in sheep lungs reached a maximum value of 5% of air space volume, compared with 9% in dog lungs. In sheep lungs 94% of vessels greater than or equal to 0.5 mm diam and 16% of smaller vessels were surrounded by cuffs. In dog lungs these values were 99 and 47%, respectively. The ratio of cuff area to vessel area reached a maximum of 2.3 in sheep lungs and 3.4 in dog lungs. In an electrical analogue model designed to simulate cuff growth, estimated interstitial resistance to liquid flow was 6–15 times higher than similar estimates in dog lungs. These species differences might be the result of differences in the composition of the interstitial gel or to differences in the mechanical linkage between the lung parenchyma and vessel wall.

Brain edema after intracerebral hemorrhage in rats: the role of iron overload and aquaporin 4

2009 ◽  
Vol 110 (3) ◽  
pp. 462-468 ◽  
Author(s):  
Wang Gai Qing ◽  
Yang Qi Dong ◽  
Tang Qing Ping ◽  
Li Guang Lai ◽  
Li Dong Fang ◽  
...  
Keyword(s):  
Iron Overload ◽  
Water Content ◽  
Brain Edema ◽  
Time Course ◽  
Iron Chelator ◽  
Brain Water Content ◽  
Edema Formation ◽  
Aqp4 Expression ◽  
The Right ◽  
Brain Water

Object Brain edema formation following intracerebral hemorrhage (ICH) appears to be partly related to erythrocyte lysis and hemoglobin release. An increase of brain water content was associated with an increase of brain iron, which is an erythrocyte degradation product. Expression of AQP4 is highly modified in several brain disorders, and it can play a key role in cerebral edema formation. However, the question whether AQP4 is regulated by drugs lacks reliable evidence, and the interacting roles of iron overload and AQP4 in brain edema after ICH are unknown. The goal of this study was to clarify the relationship between iron overload and AQP4 expression and to characterize the effects of the iron chelator deferoxamine (DFO) on delayed brain edema after experimental ICH. Methods A total of 144 Sprague-Dawley rats weighing between 250 and 300 g were used in this work. The animals were randomly divided into 4 groups. The ICH models (Group C) were generated by injecting 100 μl autologous blood stereotactically into the right caudate nucleus; surgical control rats (Group B) were generated in a similar fashion, by injecting 100 μl saline into the right caudate nucleus. Intervention models (Group D) were established by intraperitoneal injection of DFO into rats in the ICH group. Healthy rats (Group A) were used for normal control models. Brain water content, iron deposition, and AQP4 in perihematomal brain tissue were evaluated over the time course of the study (1, 3, 7, and 14 days) in each group. Results Iron deposition was found in the perihematomal zone as early as the 1st day after ICH, reaching a peak after 7 days and remaining at a high level thereafter for at least 14 days following ICH. Rat brain water content around the hematoma increased progressively over the time course, reached its peak at Day 3, and still was evident at Day 7 post-ICH. Immunohistochemical analysis showed that AQP4 was richly expressed over glial cell processes surrounding microvessels in the rat brain; there was upregulation of the AQP4 expression in perihematomal brain during the observation period, and it reached maximum at 3 to 7 days after ICH. The changes of brain water content were accompanied by an alteration of AQP4. The application of the iron chelator DFO significantly reduced iron overload, brain water content, and AQP4 level in the perihematomal area compared with the control group. Conclusions Iron overload and AQP4 may play a critical role in the formation of brain edema after ICH. In addition, AQP4 expression was affected by iron concentration. Importantly, treatment with DFO significantly reduced brain edema in rats and inhibited the AQP4 upregulation after ICH. Deferoxamine may be a potential therapeutic agent for treating ICH.

Exercise-induced satellite cell activation in growing and mature skeletal muscle

1987 ◽  
Vol 63 (5) ◽  
pp. 1816-1821 ◽  
Author(s):  
K. C. Darr ◽  
E. Schultz
Keyword(s):  
Satellite Cell ◽  
Cross Sections ◽  
Time Course ◽  
Cell Activation ◽  
Treadmill Running ◽  
Rapid Decline ◽  
Fiber Damage ◽  
Single Bout ◽  
Satellite Cell Activation ◽  
Exercise Induced

The time course and extent of satellite cell activation were studied in the soleus (m-SOL) and extensor digitorum longus (m-EDL) muscles of untrained growing and mature rats after a single bout of prolonged eccentric treadmill running. At 24, 48, 72, and 120 h postexercise, satellite cell mitotic activity was quantitated in autoradiographs of whole-fiber segments after injection of [3H]thymidine. Fiber damage and localization of labeled cells were also examined in muscle cross sections. Labeling in growing muscles progressively increased to peak levels (approximately 250% of control) at 72 h postexercise, whereas mature muscles exhibited an earlier peak (approximately 250% of control) at 24 (m-SOL) and 48 (m-EDL) h, followed by a more rapid decline to control levels by 120 h postexercise. In all exercised muscles the calculated satellite cell activation was far greater than required to repair the small number (less than 3.0%) of necrotic fibers identified at the light-microscopic level. These results suggest that satellite cells were activated not only on fibers exhibiting overt necrosis but also on those with lesions not discernible with light microscopy.

Numerical Simulation of Localized Bulging in an Inflated Hyperelastic Tube with Fixed Ends

2020 ◽  
pp. 2050118
Author(s):  
Zehui Lin ◽  
Linan Li ◽  
Yang Ye
Keyword(s):  
Axial Stress ◽  
Necessary Condition ◽  
Theoretical Studies ◽  
Inflation Pressure ◽  
Material Models ◽  
Rubber Material ◽  
Bifurcation Phenomenon ◽  
A Value ◽  
Pressure Maximum ◽  
Almost All

When a hyperelastic tube is inflated, the inflation pressure has a maximum for almost all rubber material models, but has no maximum for commonly used arterial models. It is generally believed that the pressure having a maximum is a necessary condition for localized bulging to occur, and therefore aneurysms cannot be modeled as a mechanical bifurcation phenomenon. However, recent theoretical studies have shown that if the axial stretch is fixed during inflation, localized bulging may still occur even if a pressure maximum does not exist in uniform inflation. In this paper, numerical simulations are conducted to confirm this theoretical prediction. It is also demonstrated that if the axial pre-stretch is not sufficiently large, unloading near the two ends can reduce the axial stress to a value close to zero and Euler-type buckling then occurs.

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