Volume displaced by diaphragm motion in emphysema.

To examine the effect of hyperinflation on the volume displaced by diaphragm motion (DeltaVdi), we compared nine subjects with emphysema and severe hyperinflation [residual volume (RV)/total lung capacity (TLC) 0.65 +/- 0.08; mean +/- SD] with 10 healthy controls. Posteroanterior and lateral chest X rays at RV, functional residual capacity, one-half inspiratory capacity, and TLC were used to measure the length of diaphragm apposed to ribcage (Lap), cross-sectional area of the pulmonary ribcage, DeltaVdi, and volume beneath the lung-apposed dome of the diaphragm. Emphysema subjects, relative to controls, had increased Lap at comparable lung volumes (4.3 vs. 1.0 cm near predicted TLC, 95% confidence interval 3.4-5.2 vs. 0-2.1), pulmonary rib cage cross-sectional area (emphysema/controls 1.22 +/- 0.03, P < 0.001 at functional residual capacity), and DeltaVdi/DeltaLap (0.25 vs. 0.14 liters/cm, P < 0.05). During a vital capacity inspiration, relative to controls, DeltaVdi was normal in five (1.94 +/- 0.51 liters) and decreased in four (0.51 +/- 0.40 liters) emphysema subjects, and volume beneath the dome did not increase in emphysema (0 +/- 0.36 vs. 0.82 +/- 0.80 liters, P < 0.05). We conclude that DeltaVdi can be normal in emphysema because 1) hyperinflation is shared between ribcage and diaphragm, preserving Lap, and 2) the diaphragm remains flat during inspiration.     

Relationship between axial motion and volume displacement of the diaphragm during VC maneuvers.

During semistatic inspiratory and expiratory vital capacity (VC) maneuvers, axial motion of the diaphragm was measured by lateral fluoroscopy and was compared with diaphragmatic volume displacement. Axial motion was measured at the anterior, middle, and posterior parts of the diaphragm, and the mean of these measurements was used. The volume displacement was calculated in two ways: first, from respiratory inductive plethysmograph-(Respitrace) derived cross-sectional area changes of rib cage and abdomen (Vdi,RIP) by means of a theoretical analysis described by Mead and Loring (J. Appl. Physiol. 53: 750-755, 1982) and, second, from fluoroscopically measured changes in position and anteroposterior surface of the diaphragm (Vdi,F). A very good linear relationship was found between Vdi,RIP and Vdi,F during inspiration as well as expiration (r greater than 0.95), indicating that the analysis of Mead and Loring was valid in the conditions of the present study. The diaphragmatic volume displacement (active or passive) accounted for 50-60% of VC. A very good linear relationship was also found between mean axial motion and volume displacement of the diaphragm measured with both methods during inspiration and expiration (r greater than 0.98). Our data suggest that, over the VC range, diaphragmatic displacement functionally can be represented by a pistonlike model, although topographically and anatomically it does not behave as a piston.     

Determinants of diaphragm motion in unilateral diaphragmatic paralysis.

Cranial displacement of a hemidiaphragm during sniffs is a cardinal sign of unilateral diaphragmatic paralysis in clinical practice. However, we have recently observed that isolated stimulation of one phrenic nerve in dogs causes the contralateral (inactive) hemidiaphragm to move caudally. In the present study, therefore, we tested the idea that, in unilateral diaphragmatic paralysis, the pattern of inspiratory muscle contraction plays a major role in determining the motion of the inactive hemidiaphragm. We induced a hemidiaphragmatic paralysis in six anesthetized dogs and assessed the contour of the diaphragm during isolated unilateral phrenic nerve stimulation and during spontaneous inspiratory efforts. Whereas the inactive hemidiaphragm moved caudally in the first instance, it moved cranially in the second. The parasternal intercostal muscles were then severed to reduce the contribution of the rib cage muscles to inspiratory efforts and to enhance the force generated by the intact hemidiaphragm. Although the change in pleural pressure (DeltaPpl) was unaltered, the cranial displacement of the paralyzed hemidiaphragm was consistently reduced. A pneumothorax was finally induced to eliminate DeltaPpl during unilateral phrenic nerve stimulation, and this enhanced the caudal displacement of the inactive hemidiaphragm. These observations indicate that, in unilateral diaphragmatic paralysis, the motion of the inactive hemidiaphragm is largely determined by the balance between the force related to DeltaPpl and the force generated by the intact hemidiaphragm.     

Breath-by-breath assessment of alveolar gas stores and exchange.

The volume of O(2) exchanged at the mouth during a breath (Vo(2,m)) is equal to that taken up by pulmonary capillaries (Vo(2,A)) only if lung O(2) stores are constant. The latter change if either end-expiratory lung volume (EELV), or alveolar O(2) fraction (Fa(O(2))) change. Measuring this requires breath-by-breath (BbB) measurement of absolute EELV, for which we used optoelectronic plethysmography combined with measurement of O(2) fraction at the mouth to measure Vo(2,A) = Vo(2,m) - (DeltaEELV x Fa(O(2)) + EELV x DeltaFa(O(2))), and divided by respiratory cycle time to obtain BbB O(2) consumption (Vo(2)) in seven healthy men during incremental exercise and recovery. To synchronize O(2) and volume signals, we measured gas transit time from mouthpiece to O(2) meter and compared Vo(2) measured during steady-state exercise by using expired gas collection with the mean BbB measurement over the same time period. In one subject, we adjusted the instrumental response time by 20-ms increments to maximize the agreement between the two Vo(2) measurements. We then applied the same total time delay (transit time plus instrumental delay = 660 ms) to all other subjects. The comparison of pooled data from all subjects revealed r(2) = 0.990, percent error = 0.039 +/- 1.61 SE, and slope = 1.02 +/- 0.015 (SE). During recovery, increases in EELV introduced systematic errors in Vo(2) if measured without taking DeltaEELV x Ca(O(2))+EELV x DeltaFa(O(2)) into account. We conclude that optoelectronic plethysmography can be used to measure BbB Vo(2) accurately when studying BbB gas exchange in conditions when EELV changes, as during on- and off-transients.     

Fiber capillarization relative to mitochondrial volume in diaphragm of shrew.

The objective was to examine fiber capillarization in relation to fiber mitochondrial volume in the highly aerobic diaphragm of the shrew, the smallest mammal. The diaphragms of four common shrews [Sorex araneus; body mass, 8.2 +/- 1.3 (SE) g] and four lesser shrews (Sorex minutus, 2.6 +/- 0.1 g) were perfusion fixed in situ, processed for electron microscopy, and analyzed by morphometry. Capillary length per fiber volume was extremely high, at values of 8,008 +/- 1,054 and 12,332 +/- 625 mm(-2) in S. araneus and S. minutus, respectively (P = 0.012), with no difference in capillary geometry between the two species. Fiber mitochondrial volume density was 28.5 +/- 2.3% (S. araneus) and 36.5 +/- 1.4% (S. minutus; P = 0.025), yielding capillary length per milliliter mitochondria values (S. araneus, 27.8 +/- 1.5 km; S. minutus, 33.9 +/- 2.2 km; P = 0.06) as high as in the flight muscle of the hummingbird and small bats. The size of the capillary-fiber interface (i.e., capillary surface per fiber surface ratio) per fiber mitochondrial volume in shrew diaphragm was also as high as in bird and bat flight muscles, and it was about two times greater than in rat hindlimb muscle. Thus, whereas fiber capillary and mitochondrial volume densities decreased with increased body mass in S. araneus compared with S. minutus Soricinae shrews, fiber capillarization per milliliter mitochondria in both species was much higher than previously reported for shrew diaphragm, and it matched that of the intensely aerobic flight muscles of birds and mammals.     

The measurement of volume change by capillary dilatometry

Capillary dilatometry enables direct measurement of changes in volume, an extensive thermodynamic property. The results provide insight into the changes in hydration that occur upon protein folding, ligand binding, and the interactions of proteins with nucleic acids and other cellular components. Often the entropy change arising from release of hydrating solvent provides the main driving force of a binding reaction. For technical reasons, though, capillary dilatometry has not been as widely used in protein biochemistry and biophysics as other methods such as calorimetry. Described here are simple apparatus and simple methods, which bring the technique within the capacity of any laboratory. Even very simple results are shown to have implications for macromolecular‐based phenomena. Protein examples are described.     

对胸腹部膨胀体积法测量小鼠潮气量可行性的评价

目的：探讨利用双体描箱法对胸腹部膨胀体积测量小鼠潮气量的可行性。方法：选用6只呼吸频率在90～120h／min的小鼠,通过双体描箱法进行潮气量和胸腹部膨胀体积的同步测量。结果：小鼠胸腹部膨胀体积为（0.369±0.014）ml,潮气量为（0.356±0.012）ml,前者显著高于后者（P〈0.01）。结论：目前常用的以胸腹部膨胀体积代替潮气量的测量方法不能准确测定潮气量。     

Ultrasonographic measurement of the thyroid volume

According to the published data, endemic goiter was until recently, still present in some regions in Croatia. In this study the thyroid volume in grown-up, student population was measured. It was also analyzed which of the several traditional physiological attributes (body weight, body height, and body surface area (BSA)) were best correlated with the thyroid volume. Fifty one randomly selected female students from University of Zagreb Medical School were studied. Mean age of our subjects was 22 (range 20-38). All of them were healthy and with normal thyroid hormonal status. The mean thyroid volume was 10.68+/-2.83 mL (range 5.71-17.09 mL). The results show that thyroid volume was best correlated with body height (r=0.37; p=0.001), followed with body surface area (r=0.28; p=0.017). The thyroid volume was found normal in all our subjects.     

Uptake of liposome-entrapped mannitol by diaphragm.

Tissue uptake of liposome-entrapped radioactive mannitol was examined in rats and mice after both intravenous and intraperitoneal injection. In accord with results from other laboratories, liver and spleen effectively accumulated liposomes. Diaphragm also took up significant amounts of label. In nearly all cases the radioactive content of perfused tissues was less than tissues which were not perfused but this was statistically significant in only a few comparisons.     

Unity of measurement and motion

Issues addressed in H.H. Pattee's origin of life laboratory in the 1960s and their connection to the physics–evolution–language problematic are indicated. The problem of quantum measurement played a central role. The problem is herein examined in the light of the fluctuon model; in particular, as the model applies to gravity. The main conclusion is that measurement and motion are a unitary process. All accelerations are accompanied by a cycle involving the annihilation and creation of superpositions. Gravitational collapse is also a cyclic process in the fluctuon model. By a suitable transformation, it can be seen that interactions underlying superpositional collapse are the same as those operative in gravitational collapse. Implications for the origin of cellular life and the development of symbolic systems are considered.     

Method of evaluating respiratory induced organ motion by vector volume histogram

PurposePublished organ motion data have been collected from measurements of a limited number of points within the organ, the centroid, or the edge of the organ. These are derived from the spatial characteristics of respiratory induced motion; however, this approach does not consider non-rigid organ deformation. We propose a novel quantitative method for evaluating respiratory induced organ motion using Deformable Image Registration (DIR).MethodTwo phases from a 4-dimensional computed tomography (4D CT) dataset at maximum inspiration and expiration were each taken from five patients. The left and right lungs, esophagus, stomach, spinal cord, and liver were manually contoured in the end-expiration phase. The hybrid deformable registration algorithm of the RayStation treatment planning system (TPS) was used to deform the end-expiration phase to the end-inspiration phase. From this, the deformation vector field (DVF) was calculated. DVFs consist of DVF_LR (left-right), DVF_AP (anterior-posterior), and DVF_SI (superior-inferior) as separate files. We calculated the vector volume histogram (VVH) and L_max (maximum absolute vector of the organ) to evaluate every vector for each individual organ. We also measured respiratory organ motion from the position of the organ centroid in two phases.ResultsVVH enabled us to find the absolute distance and volume of the organ contributing to motion points on the curve. Organ motion using the centroid method was smaller than L_max using VVH. Using the centroid method, it is difficult to evaluate the deformable organ motion.ConclusionVVH may be a useful technique in evaluating organ volumetric change during respiratory organ motion.