A simplified method for measuring helium closing volume.

A simple method for delivering a constant volume of helium for the measurement of airway closing volume is described. Using a standard fiveway valve and PVC plastic irrigation pipe, a device was constructed which permits the delivery of a uniform volume of helium and avoids the troublesome valve change during inspiration. Results obtained when using this device were comparable to those with the use of conventional bag to contain the helium.     

Variability of the closing volume measurement in normal subjects.

The repeatablilty of the measurement of closing volume (nitrogen method) in healthy, normal subjects was investigated. At least 7 consecutive measurements at 5-min intervals were made in each of 22 subjects. The mean coefficient of variation for the absolute volume of phase IV was 36.1 per cent and for the percentage ratio of phase IV to vital capacity, 36.1 per cent. Repeated measurements by the same observer of the same records on various days did not differ significantly (P greater than 0.5). There was a significant difference (P less than 0.05) between 2 observers measuring the same records, but there was no significant difference between the two observers in the variance of the closing variability in the same subject, it may be necessary to perform several closing volume maneuvers in each subject to establish his or her range before changes in the closing volume can be interpreted.     

Effect of beta-adrenergic stimulation on the closing volume in normal subjects (author's transl]

In 12 normal subjets we studies the effects of beta-adrenergic stimulation (Salbutamol, 500 microgram inhaled) on the closing volume (CV) and the closing capacity and on the ratios of these indexes to the vital capacity (VC) and the total lung capacity, respectively. CV and CV/VC % increased in ten subjects wereas it decreased in two subjects. On an average, the changes were small but significant (p less than 0.01) and could be duplicated in four subjects. Similar studies have yielded variable results. The reasons for those variation could be attributed either to technical or/and individual differences in the resulting effect of beta stimulation on respiratory mechanics.     

Heart volume determination with phase synchronization in normal subjects and postinfarct patients.

The authors investigated the influence of the systole-and-dyastole cycle upon the cardiac volume measured radiologically with ECG phase synchronization in prone subjects. Measurements were made in 30 healthy subjects and 27 patients with a history of myocardial infarction, all of them ambulatory. As expected, the mean cardiac volume relative to body surface was greater in postinfarct patients than in normal subjects to a high degree of statistical significance. Conversely, the differences between end-systolic and end-diastolic cardiac volumes fell short of statistical significance both in healthy subjects and in postinfarct patients. Accordingly, radiological measurements of cardiac volume without phase synchronization seem justified in the functional evaluation of postinfarct patients.     

Magnetic resonance imaging: a reliable method for measuring pancreatic volume in Type 1 diabetes.

AIM: To validate magnetic resonance imaging (MRI) for monitoring pancreatic atrophy in Type 1 diabetes. METHODS: Twelve male patients with Type 1 diabetes of duration >or= 10 years (median age 28, range 19-32 years) and 12 healthy controls (median age 30, range 22-36 years) were invited for two abdominal MRI scans, 14 days apart. Four sequences were used: standard T1-weighted; standard T2-weighted; volumetric interpolated breath-hold examination (VIBE); and T1-weighted breath hold with fat suppression (T1BHFS). The pancreas was identified on coded images by one observer and volumes estimated by interpolation. RESULTS: Eleven patients and all controls were scanned twice. Visualization of the pancreas was best with VIBE and T1BHFS, allowing volume estimation from 47 and 46 scans, respectively. The pancreatic volume of patients estimated from these sequences were half those of controls (52.4 ml, +/- 17.1 ml, mean +/- sd) vs. (101 ml, +/- 19.5 ml, P < 0.001) and estimates showed little bias between visits; mean difference 1.1 ml (95% CI; -3.1 to 5.3 ml, P = 0.61) using VIBE and -2.6 ml (-5.8 to 0.6 ml, P = 0.03) using T1BHFS. Both sequences gave similar precision; the standard deviation of the differences in volume estimates between visits was 9.7 ml for VIBE and 7.3 ml for T1BHFS, although mean volumes estimated from T1BHFS were 4.9 ml lower (-8.2 to -1.7 ml, P = 0.005). CONCLUSIONS: Pancreatic volume can be measured reliably using MRI and shows a 48% reduction in long-standing Type 1 diabetes as compared with age-matched normal subjects. MRI should prove useful in determining the natural history of pancreatic atrophy in diabetes.     

Increased volume and decreased emptying of the gallbladder in large (morbidly obese, tall normal, and muscular normal) people

Impaired gallbladder emptying has been suggested as a possible factor in the pathogenesis of gallstones. Obese people have an increased incidence of gallstones, but there is no evidence of this in nonobese large people. This study was undertaken to determine if abnormal gallbladder motility is present in obese people. Fasting gallbladder volumes were determined using real-time ultrasound in 18 morbidly obese subjects whose weights were in a steady state [45 kg (100 lb) over ideal weight or twice expected weight for age and height; 9 males, 9 females], 18 age- and sex-matched volunteers of average size, and 18 nonobese large normal males (9 tall, 9 muscular). Gallbladder emptying studies with 99mtechnetium-diisopropyliminodiacetic acid were performed using 200 ml of 10% cream as a stimulus. The small-volume liquid fatty meal contained 113indium-diethylenetriaminepentaacetic acid to control for differences in gastric emptying in obesity. The gallbladder emptying rate in large people, both obese and nonobese, was less than that in normals of average size (p = 0.05). Fasting gallbladder volumes in large people were: obese, 41 ml (37-66 ml) (median; 95% confidence limits); nonobese large normal, 40 ml (27-43 ml). These values were greater than in normals of average size [17 ml (14-21 ml) (p = 0.03)]. Postprandial gallbladder volumes were also greater in large people: obese, 15 ml (8-23 ml); nonobese large normal, 20 ml (13-23 ml) compared with 2 ml (1-5 ml) in normals of average size (p less than 0.05). There were no differences between obese and nonobese large people. There were no differences in gastric emptying rates or in cholecystokinin, gastrin, motilin, and secretin release between obese and normal subjects. Gallbladder volume is crudely proportional to body size. Although fasting and postprandial volumes are greater in obesity, this is also present in nonobese, relatively size-matched controls. These data do not support a role for impaired gallbladder emptying in gallstone formation in obese patients whose weights are in a steady state.     

Determination of the closing volume and its value in the early detection of chronic obstructive lung disease]

The determination of the closing volume appears as a good test for the early detection of obstructive lung diseases and of disorders in the ventilation distribution. Easy to perform, its use should become extensive. To make use of this investigation under the better possible conditions, it is strictly necessary to respect methodologic norms and an excellent technology and to be aware of some morphologic anomalies in the curves.     

Effectiveness of the fold plication method in lung volume reduction surgery

OBJECT: The fold plication method is a new operative procedure for lung volume reduction surgery whereby the target area is obliterated by plicating the folded tissue using a knifeless stapler, without the use of bovine pericardium. The effectiveness of this new method was evaluated in patients with advanced pulmonary emphysema. PATIENTS AND METHODS: Two weeks before and 6 months after surgery, pulmonary function, static lung compliance, maximal esophageal pressure, maximal inspiratory and expiratory mouth pressures, 6-min walking distance and the Borg scale were determined in twenty consecutive patients who underwent video-assisted thoracoscopic unilateral surgery. RESULTS: There was an increase in forced expiratory volume in one second (31%), forced vital capacity, peak expiratory flow rate and maximal voluntary ventilation, and a decrease in functional residual capacity (-16%) measured by plethysmograph. Static lung compliance decreased, and maximal esophageal pressure, and maximal inspiratory and expiratory mouth pressures increased. The 6-min walking distance increased (20%) and the Borg scale decreased (5.9 to 3.5). CONCLUSION: The results compare favorably with those obtained with other methods. Thus, the fold plication method could be considered an alternative procedure for lung volume reduction surgery.     

Relationship between lung volume, maximal expiratory flow, forced expiratory volume in one second, and tracheal area in normal men and women

Tracheal area at different lung volumes was measured using acoustic reflection technique, flow-volume curves, and lung volumes by body plethysmography in 24 healthy adults (14 men, 10 women) in order to study the relationship between tracheal area and lung volume, and between tracheal area and maximal expiratory flow rates. Each individual tracheal area was greatest at TLC and lowest at RV; this lung volume dependence was significantly greater in men than in women. When tracheal areas versus absolute lung volumes were plotted for the entire group and the linear regression analysis on the data was performed, no significant correlation between lung volume and tracheal area in men was found, but a highly significant correlation was found in women. Using the analysis proposed by Mead (Am Rev Respir Dis 1980; 121:339-42) in his assessment of dysanapsis, the ratio of tracheal area/lung volume versus lung volume was plotted and the slope was found to be negative (and close to -1) in men and positive in women. Therefore it was concluded that the relationship between tracheal area and lung volume is consistent with the hypothesis that in men and women lung parenchyma grows independently of the airways; furthermore, in women the airways grow faster than the lung parenchyma. In addition, in women there was good correlation between tracheal area and FEV1, as well as maximal expiratory flow rates at 50 and 25% of VC. For men, these correlations were less consistent and depended on the lung volume at which tracheal area was measured.     

Appraisal of a new test: Between-technician variation in the measurement of closing volume.

To determine the between-technician variation in the measurement of closing volume, 24 subjects were divided into 3 blocks of 8 subjects each. Each block was then tested by a pair of technicians. Each of the 3 technicians involved in the study tested 16 subjects. It was later necessary to reject the tracings of 2 subjects in one of the 3 blocks, leaving 22 for analysis. The N2 method of determining closing volume was used. The statistical analysis was performed separately on the following measures derived from the tracings: expired vital capacity, planimetry of the area under the curve, total lung capacity, closing volume as a per cent of expired vital capacity, and closing capacity as a per cent of total lung capacity. All tracings were assessed by each technician. Two separate analyses of variance were then carried out to determine, respectively, the components of variance in the administration of the test and in the interpretation of the tracings. Because different persons were able to administer the test the same way, it seems that closing volume poses no problem in administration, provided that instructions as to how to perform the test are closely followed. In the interpretation of the tracings, significant differences were found for all measures, except planimetry; however, not all of these have the same practical implications. Some tracings were found "difficult" to interpret and contributed more to the over-all variation than did others. When making use of a new test in a population study, the between-technician variation should be determined before the study is begun.     

Fast-CT evaluation of the effect of lung volume on upper airway size and function in normal men.

The present study was performed to evaluate the regional changes in pharyngeal cross-sectional area (CSA) that occur with changes in lung volume in normal men. Fast-CT and genioglossal electromyogram (EMGgg) were used to study upper airway (UA) size and dilator muscle activity at TLC, lung volume at end-tidal inspiration (VTei), FRC, and residual volume (RV) in 30 men with a mean age of 46 +/- 3 yr and no significant sleep-disordered breathing, mean AHI = 4 +/- 1 per hour. Compared with values at FRC, minimum CSA (Amin) increased 154 +/- 31% at TLC (p = 0.0001), 19 +/- 10% at VTei (p = 0.03), and there was a trend toward a decrease of 31 +/- 12% at RV (p = 0.07). Similar but smaller changes were observed in mean CSA (Amean), with an increase of 69 +/- 14% at TLC (p = 0.0001), 8 +/- 5% at VTei (p = 0.01), and a decrease of 17 +/- 7% at RV (p = 0.01). Both the velopharyngeal (VP) and orohypopharyngeal (OHP) segments of the UA increased in size with increasing lung volume. Both Amin and Amean of the OHP segment at TLC were larger (55 +/- 19 and 38 +/- 14%, respectively) than the respective measurements in the VP segment. EMGgg activity doubled from 12 +/- 1 microV at FRC to 25 +/- 1 microV at TLC (p = 0.006). There was no change in EMGgg with tidal ventilation or with exhalation to RV. Changes in CSA directly paralleled changes in lung volume in this group of normal awake nonobese men.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of the DMO method for measuring intracellular pH.

Intracellular pH in single muscle fibres from Balanus nubilus was determined, both by the weak acid distribution method (using 5,5-dimethyl-2,4-oxazolidine dione) and by means of a glass pH microelectrode, following prolonged equilibrations in normal, acid or alkaline Ringer solutions. In the DMO method [3H]inulin was combined with [14C]DMO so that an extracellular space could be calculated for each 'DMO space' on each fibre. Less than ideal uptake curves were obtained both for [14C]DMO and [3H]inulin, yet the calculated pHi compared favourably with the microelectrode pHi, especially when the DMO-pHi was calculated from [14C]DMO and [3H]inulin values obtained by extrapolating the 'plateaus' of the uptake curves to time zero. The Waddell and Butler equation was examined to determine why acceptable pHi values should be forthcoming from less than ideal uptake data.     

改良的LCAT测定及其在肾脏疾病中的临床意义

用改良Ｓｐｅｒｒｙ自身底物法分别测定了３４例正常人及１５８例肾脏病患者的血清ＬＣＡＴ活性，此法简便、重复性好。联合ＨＤＬ－亚组份检测不失为一种观察各种疾病所致脂质代谢异常的敏感指标。本文测定结果表明，肾脏病患者的血清ＬＣＡＴ活性较正常组显著降低，差异非常显著，证实肾脏疾患时伴有脂酶活性障碍。而且还发现尿黄症、肾炎患者存在低ＨＤＬ血症，尤以ＨＤＬ３降低为明显，而肾病组ＨＤＬ升高，但无统计学意义。唯Ｈ