Hydraulic conductivity of canine parietal pleura in vivo

1990 ◽  
Vol 69 (2) ◽  
pp. 438-442 ◽  
Author(s):  
D. Negrini ◽  
M. I. Townsley ◽  
A. E. Taylor
Keyword(s):  
Hydraulic Conductivity ◽  
Chest Wall ◽  
Body Position ◽  
Linear Regression Analysis ◽  
Isotonic Saline ◽  
Parietal Pleura ◽  
Autologous Plasma ◽  
Anesthetized Dogs ◽  
Spontaneously Breathing

The hydraulic conductivity (Lp) of the parietal pleura was measured in vivo in spontaneously breathing anesthetized dogs in either the supine (n = 8) or the prone (n = 7) position and in an excised portion of the chest wall in which the pleura and its adjacent tissue were intact (n = 3). A capsule was glued to the exposed parietal pleura after the intercostal muscles were removed. The capsule was filled with either autologous plasma or isotonic saline. Transpleural fluid flow (V) was measured at several transpleural hydrostatic pressures (delta P) from the rate of meniscus movement within a graduated pipette connected to the capsule. Delta P was defined as the measured difference between capsule and pleural liquid pressures. The Lp of the parietal pleura was calculated from the slope of the line relating V to delta P by use of linear regression analysis. Lp in vivo averaged 1.36 X 10(-3) +/- 0.45 X 10(-3) (SD) ml.h-1.cmH2O-1.cm-2, regardless of whether the capsule was filled with plasma or saline and irrespective of body position. This value was not significantly different from that measured in the excised chest wall preparation (1.43 X 10(-3) +/- 1.1 X 10(-3) ml.h-1.cmH2O-1.cm-2). The parietal pleura offers little resistance to transpleural protein movement, because there was no observed difference between plasma and saline. We conclude that because the Lp for intact parietal pleura and extrapleural interstitium is approximately 100 times smaller than that previously measured in isolated stripped pleural preparations, removal of parietal pleural results in a damaged preparation.

In vivo regional diaphragm function in dogs

1989 ◽  
Vol 67 (2) ◽  
pp. 655-662 ◽  
Author(s):  
J. Sprung ◽  
C. Deschamps ◽  
R. D. Hubmayr ◽  
B. J. Walters ◽  
J. R. Rodarte
Keyword(s):  
Mechanical Ventilation ◽  
Chest Wall ◽  
Spontaneous Breathing ◽  
Considerable Variability ◽  
Diaphragm Function ◽  
Left Hemidiaphragm ◽  
Anesthetized Dogs ◽  
Abdominal Surface ◽  
Crural Diaphragm

A biplane videofluorographic system was used to track the position of metallic markers affixed to the abdominal surface of the left hemidiaphragm in supine anesthetized dogs. Regional shortening was determined from intermarker distances of rows of markers placed along muscle bundles in the ventral, middle, and dorsal regions of the costal diaphragm and of one row on the crural diaphragm. Considerable variability of regional shortening was seen in a given row, which was reproducible on repeat study in individual dogs but which differed between mechanical ventilation and spontaneous breathing. There were no consistent patterns among dogs. Regional shortening obtained from the change in length of rows extending from chest wall to central tendon showed no consistent differences among dogs during spontaneous breathing. At equal tidal volumes, all regions (except the ventral costal diaphragm) shortened more during spontaneous breathing than during mechanical ventilation.

Permeability of parietal pleura to liquid and proteins

1994 ◽  
Vol 76 (2) ◽  
pp. 627-633 ◽  
Author(s):  
D. Negrini ◽  
D. Venturoli ◽  
M. I. Townsley ◽  
R. K. Reed
Keyword(s):  
Lactate Dehydrogenase ◽  
Hydraulic Conductivity ◽  
Pressure Gradient ◽  
Permeability Coefficient ◽  
Parietal Pleura ◽  
Reflection Coefficients ◽  
Solvent Drag ◽  
Albumin Solution ◽  
Spontaneously Breathing ◽  
Intracapsular Pressure

The permselectivity of the parietal pleura was determined in spontaneously breathing anesthetized rabbits and dogs. In rabbits, we injected intrapleurally 5 ml of 1-g/dl albumin solution containing 100 microCi of 131I-labeled albumin plus 100 microCi of either lactate dehydrogenase (LDH) or alpha 2–125I-macroglobulin. Dogs received 100 ml of 1-g/dl albumin solution containing 100 microCi of 131I-albumin plus 100 microCi of alpha 2–125I-macroglobulin. A transpleural pressure gradient was set, lowering the intracapsular pressure to -30 cmH2O. The solvent drag reflection coefficients (sigma f) were calculated as the ratio between tracer concentrations in capsular and pleural liquid collected at 60–180 min. In rabbits sigma f was 0.44 +/- 0.2 (SD) for albumin, 0.84 +/- 0.1 for LDH, and 0.93 +/- 0.05 for alpha 2-macroglobulin. In dogs sigma f was 0.30 +/- 0.19 for albumin and 0.53 +/- 0.15 for alpha 2-macroglobulin. The hydraulic conductivity of the parietal pleura was 2.18 +/- 1.54 microliters.h-1.cmH2O-1.cm-2 in rabbits and 1.22 +/- 1.13 microliters.h-1.cmH2O-1.cm-2 in dogs. The parietal pleura could be modeled by two pore populations with radii of 83–89 and 156-222 A. The permeability coefficient averaged 0.08–0.21 x 10(-6) cm/s for albumin, 0.06–0.09 x 10(-6) cm/s for LDH, and 0.01-0.03 x 10(-6) cm/s for alpha 2-macroglobulin.

Noninvasive determination of hemoglobin saturation in dogs by derivative near-infrared spectroscopy

1989 ◽  
Vol 256 (5) ◽  
pp. H1493-H1499 ◽  
Author(s):  
M. Ferrari ◽  
D. A. Wilson ◽  
D. F. Hanley ◽  
J. F. Hartmann ◽  
M. C. Rogers ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Sagittal Sinus ◽  
Hemoglobin Saturation ◽  
Wide Range ◽  
Anesthetized Dogs ◽  
Predicted Values

An in vivo method utilizing derivative near-infrared spectroscopy was developed to noninvasively determine cerebral venous hemoglobin O2 saturation (SVO2). The method was tested on eight pentobarbital-anesthetized dogs ventilated with differing inspired O2 mixtures to force changes in SVO2 over a wide range. Spectral data obtained by transilluminating the tissues surrounding the superior sagittal sinus (SS) were transformed into first derivative units for correlation with SVO2 data measured from the SS. Linear regression analysis was applied to data obtained from five dogs and used to build a three-wavelength algorithm for predicting brain SVO2. In three dogs, SVO2 was varied to test this equation ability to predict SVO2. The standard deviation of differences between measured SVO2 and SVO2 predicted from 31 separate spectra was 3.2%. These predicted values, when regressed against the sampled SVO2, yielded an r value of 0.97. The results demonstrate that during hypoxic hypoxia (HH) it is possible to noninvasively quantify SVO2 with the use of infrared spectroscopy.

Active and passive respiratory mechanics in anesthetized dogs

1986 ◽  
Vol 61 (5) ◽  
pp. 1647-1655 ◽  
Author(s):  
W. A. Zin ◽  
A. Boddener ◽  
P. R. Silva ◽  
T. M. Pinto ◽  
J. Milic-Emili
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Power Functions ◽  
Intrinsic Resistance ◽  
Pressure Losses ◽  
Inspiratory Muscles ◽  
Anesthetized Dogs ◽  
Force Velocity ◽  
Spontaneously Breathing ◽  
Active Impedance

In six spontaneously breathing anesthetized dogs (pentobarbital sodium, 30 mg/kg) airflow, volume, and tracheal and esophageal pressures were measured. The active and passive mechanical properties of the total respiratory system, lung, and chest wall were calculated. The average passive values of respiratory system, lung, and chest wall elastances amounted to, respectively, 50.1, 32.3, and 17.7 cmH2O X l-1. Resistive pressure-vs.-flow relationships for the relaxed respiratory system, lung, and chest wall were also determined; a linear relationship was found for the former (the total passive intrinsic resistance averaged 4.1 cmH2O X l-1 X s), whereas power functions best described the others: the pulmonary pressure-flow relationship exhibited an upward concavity, which for the chest wall presented an upward convexity. The average active elastance and resistance of the respiratory system were, respectively, 64.0 cmH2O X l-1 and 5.4 cmH2O X l-1 X s. The greater active impedance reflects pressure losses due to force-length and force-velocity properties of the inspiratory muscles and those due to distortion of the respiratory system from its relaxed configuration.

Regional blood flow to canine parietal pleura and internal intercostal muscle

1991 ◽  
Vol 70 (1) ◽  
pp. 97-102 ◽  
Author(s):  
M. I. Townsley ◽  
D. Negrini ◽  
J. L. Ardell
Keyword(s):  
Blood Flow ◽  
Chest Wall ◽  
Regional Blood Flow ◽  
Body Position ◽  
Parietal Peritoneum ◽  
Parietal Pleura ◽  
Intercostal Muscle ◽  
Order Of Magnitude ◽  
Lateral Decubitus ◽  
Mediastinal Pleura

Transcapillary Starling forces in the parietal pleura and the underlying interstitium may potentially contribute to the exchange of fluid across this barrier. However, the extent of blood flow to the parietal pleura has not been measured. Thus, using standard microsphere techniques, we compared blood flow to the parietal pleura, including the subpleural interstitium, with blood flow to the adjacent internal intercostal muscle, as well as with flows to other serous tissues, including mediastinal pleura, pericardium, and parietal peritoneum, in anesthetized dogs that were either breathing spontaneously (n = 9) or ventilated to control arterial PCO2 (n = 5). Blood flow (ml.min-1.g-1) was measured after 20 min of equilibration in four successive body positions: right lateral decubitus, supine, left lateral decubitus, and prone. Overall, flow to parietal pleura was not different in spontaneous [1.07 +/- 0.14 (SE)] and mechanically ventilated animals (0.74 +/- 0.11). Flow to the internal intercostal muscle was significantly less than pleural blood flow, averaging 0.24 +/- 0.03 and 0.16 +/- 0.03 in the same groups, although again there was no effect of ventilation mode. Blood flow to other serous tissues in the thoracic cavity, specifically the mediastinal pleura (0.67 +/- 0.14) and pericardium (0.88 +/- 0.22), was similar to parietal pleural flow, whereas that to the parietal peritoneum was an order of magnitude lower (0.09 +/- 0.02, P less than 0.05). Changing body position had no effect on blood flow to any of the sampled tissues. Blood flow to the dorsal aspect of the chest wall muscle in spontaneously breathing animals tended to be greater than that to lateral or ventral portions of the chest wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation of a Viable Population of Indium-111- Labelled Human Blood Platelets

1979 ◽  
Vol 42 (05) ◽  
pp. 1473-1482 ◽  
Author(s):  
A Dup Heyns ◽  
P N Badenhorst ◽  
H Pieters ◽  
M G Lötter ◽  
P C Minnaar ◽  
...  
Keyword(s):  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Kinetic Studies ◽  
Physiological Saline ◽  
Human Platelets ◽  
Autologous Plasma ◽  
Platelet Suspension ◽  
Viable Population ◽  
Indium 111

SummaryFactors influencing labelling of human platelets with 111Indium-8-hydroxyquinoline ([111In]-oxine) in a physiological saline medium were investigated. The efficiency of labelling is influenced by time of incubation, concentration of oxine, and pH of the incubating medium. It was found that a viable platelet population could be labelled under the following conditions: (1) centrifugation of platelet rich plasma in polystyrene conical tubes at 800 g for 15 min; (2) resuspension of the platelet pellet in saline, pH 5.5; (3) incubating for 30 min at 22°C with [111In]-oxine at a concentration of 6.25 mg oxine/litre platelet suspension; (4) washing once with platelet poor autologous plasma (PPP); and (5) finally resuspending the platelets in PPP. The labelled platelets aggregated normally with collagen and ADP. Electron microscopy, done immediately after labelling, showed internal organelle reorganization characteristic of activated platelets. These ultrastructural features were reversible on incubation in PPP at 37°C for 30 min. The 111In is not released from aggregated platelets and the label does not elute from incubated platelets for at least five hr. We conclude that human platelets thus labelled are suitable for in vivo kinetic studies.

scholarly journals Poor Mitochondrial Health and Systemic Inflammation? Testing of a Classical Hypothesis

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 126-127
Author(s):  
Marta Zampino ◽  
Luigi Ferrucci ◽  
Richard Spencer ◽  
Kenneth Fishbein ◽  
Eleanor Simonsick ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Fat Body ◽  
Reference Group ◽  
Linear Regression Analysis ◽  
Oxidative Capacity ◽  
Conclusive Evidence ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Severe Impairment

Abstract Chronic low-grade inflammation often occurs with aging and has been associated with negative health outcomes. Despite extensive research on the origins of “inflammaging”, the causative mechanisms remain unclear. However, a connection between poor mitochondrial health and chronic inflammation has been hypothesized, with decreasing mitochondrial function occurring with age and precipitating an increase in reactive oxygen species and other pro-inflammatory macromolecules such as mitochondrial DNA. We tested this hypothesis on a population of 619 subjects from the Baltimore Longitudinal Study of Aging, measuring muscle mitochondrial oxidative capacity in vivo by phosphorus magnetic resonance spectroscopy (P-MRS), and plasma interleukin (IL)-6, the most widely used biomarker of inflammaging. The P-MRS-derived post-exercise phosphocreatine recovery time constant tau-PCr, a measure of oxidative capacity, was expressed as a categorical variable through assignment to quintiles. Participants in the first quintile of tau-PCr (best mitochondrial function) were taken as reference and compared to the others using linear regression analysis adjusted for sex, age, lean and fat body mass, and physical activity. Those participants with the lowest oxidative capacity had significantly higher log(IL-6) levels as compared to the reference group. However, data from the other quintiles was not significantly different from the reference values. In conclusion, severe impairment of oxidative capacity is associated with increased inflammation. This study design does not provide conclusive evidence of whether increased inflammation and impaired bioenergetic recovery are both caused by underlying poor health status, or whether mitochondrial deficits lead directly to the observed inflammation; we anticipate addressing this important question with longitudinal studies.

scholarly journals Performance of microvascular anastomosis with a new robotic visualization system: proof of concept

2021 ◽  
Author(s):  
F. Boehm ◽  
P. J. Schuler ◽  
R. Riepl ◽  
L. Schild ◽  
T. K. Hoffmann ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Body Position ◽  
Head Movements ◽  
Camera System ◽  
Visualization System ◽  
Head Mounted Display ◽  
General Evaluation ◽  
Surgical Field ◽  
Technical Instructions

AbstractMicrovascular procedures require visual magnification of the surgical field, e.g. by a microscope. This can be accompanied by an unergonomic posture with musculoskeletal pain or long-term degenerative changes as the eye is bound to the ocular throughout the whole procedure. The presented study describes the advantages and drawbacks of a 3D exoscope camera system. The RoboticScope®-system (BHS Technologies®, Innsbruck, Austria) features a high-resolution 3D-camera that is placed over the surgical field and a head-mounted-display (HMD) that the camera pictures are transferred to. A motion sensor in the HMD allows for hands-free change of the exoscope position via head movements. For general evaluation of the system functions coronary artery anastomoses of ex-vivo pig hearts were performed. Second, the system was evaluated for anastomosis of a radial-forearm-free-flap in a clinical setting/in vivo. The system positioning was possible entirely hands-free using head movements. Camera control was intuitive; visualization of the operation site was adequate and independent from head or body position. Besides technical instructions of the providing company, there was no special surgical training of the surgeons or involved staff upfront performing the procedures necessary. An ergonomic assessment questionnaire showed a favorable ergonomic position in comparison to surgery with a microscope. The outcome of the operated patient was good. There were no intra- or postoperative complications. The exoscope facilitates a change of head and body position without losing focus of the operation site and an ergonomic working position. Repeated applications have to clarify if the system benefits in clinical routine.

Respiratory response to partial paralysis in anesthetized dogs

1984 ◽  
Vol 56 (6) ◽  
pp. 1583-1588 ◽  
Author(s):  
A. Oliven ◽  
E. C. Deal ◽  
S. G. Kelsen ◽  
N. S. Cherniack
Keyword(s):  
Motor Activity ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Peak Activity ◽  
Inspiratory Time ◽  
Muscle Paralysis ◽  
Anesthetized Dogs ◽  
Spontaneously Breathing ◽  
Partial Paralysis

The ability to maintain alveolar ventilation is compromised by respiratory muscle weakness. To examine the independent role of reflexly mediated neural mechanisms to decreases in the strength of contraction of respiratory muscles, we studied the effects of partial paralysis on the level and pattern of phrenic motor activity in 22 anesthetized spontaneously breathing dogs. Graded weakness induced with succinylcholine decreased tidal volume and prolonged both inspiratory and expiratory time causing hypoventilation and hypercapnia. Phrenic peak activity as well as the rate of rise of the integrated phrenic neurogram increased. However, when studied under isocapnic conditions, increases in the severity of paralysis, as assessed from the ratio of peak diaphragm electromyogram to peak phrenic activity, produced progressive increases in inspiratory time and phrenic peak activity but did not affect its rate of rise. After vagotomy, partial paralysis induced in 11 dogs with succinylcholine also prolonged the inspiratory burst of phrenic activity, indicating that vagal reflexes were not solely responsible for the alterations in respiratory timing. Muscle paresis was also induced with gallamine or dantrolene, causing similar responses of phrenic activity and respiratory timing. Thus, at constant levels of arterial CO2 in anesthetized dogs, respiratory muscle partial paralysis results in a decrease in breathing rate without changing the rate of rise of respiratory motor activity. This is not dependent solely on vagally mediated reflexes and occurs regardless of the pharmacological agent used. These observations in the anesthetized state are qualitatively different from the response to respiratory muscle paralysis or weakness observed in awake subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Contraction of dog trachealis muscle in vivo: role of alpha-adrenergic receptors

1980 ◽  
Vol 48 (2) ◽  
pp. 329-336 ◽  
Author(s):  
W. H. Beinfield ◽  
J. Seifter
Keyword(s):  
Adrenergic Receptors ◽  
Beta Blockers ◽  
Systemic Arterial Pressure ◽  
Alpha Adrenergic Receptors ◽  
Bilateral Vagotomy ◽  
Cervical Trachea ◽  
Spontaneously Breathing ◽  
Trachealis Muscle

Contraction, relaxation, and longitudinal tension were recorded by isometric strain gauge arches attached to cervical tracheal muscle (CTM) in 60 spontaneously breathing dogs anesthetized with pentobarbital. Intravenous norepinephrine (NE) (3 X 10(-9), 6 X 10(-9), 1.2 X 10(-8), and 2.4 x 10(-8) mol/kg) increased spontaneous mechanical activities (SMA) and caused dose related contraction of CTM in all dogs even though there was no pretreatment with beta-blockers. These activities were first potentiated by propranolol and then prevented by phentolamine. NE briefly decreased SMA and induced CTM relaxation prior to the onset of contraction in one-third of dogs. Propranolol prevented this initial relaxation. CTM responses induced by NE were 1) not significantly altered by atropine, tripelennamine, bilateral vagotomy, curarization, and complete tracheal transection below transducer sites; 2) unrelated to passive constriction of cervical trachea associated with airway elongation; and 3) independent of reflexes initiated by elevations of systemic arterial pressure. The moles per kilogram doses of acetylcholine were found to exceed those of NE when their intravenous administration caused equal CTM contractions in the same dog. These findings are consistent with the existence of alpha-adrenergic receptors in CTM.

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