scholarly journals Vertical Distributions of Pulmonary Diffusing Capacity and Capillary Blood Flow in Man

1973 ◽  
Vol 52 (2) ◽  
pp. 359-369 ◽  
Author(s):  
Edward D. Michaelson ◽  
Marvin A. Sackner ◽  
Robert L. Johnson
1965 ◽  
Vol 20 (6) ◽  
pp. 1199-1204 ◽  
Author(s):  
Gordon G. Power ◽  
Richard W. Hyde ◽  
Raymond J. Sever ◽  
Frederic G. Hoppin ◽  
Jean R. Nairn

We studied possible causes of the decreased arterial oxygen saturation seen when a subject is accelerated in a centrifuge by measuring simultaneously the pulmonary diffusing capacity, DlCO, and the effective pulmonary capillary blood flow, Qc, using breath-holding techniques with carbon monoxide and acetylene. After 1 min of forward ("eyeballs in") acceleration at eight times normal gravity, 8 G, average Dl decreased 35% from an initial control of 33.7 to 21.5 ml/(min x mm Hg) in four subjects. Although this decrease was statistically significant, the values observed were not low enough to indicate that impaired diffusion was a prime cause of arterial unsaturation. Average Qc decreased 35% during acceleration from an initial control value of 12.9 to 8.2 liters/min, also a significant change. These values may have indicated that total pulmonary blood flow was reduced, but a more likely explanation is that a large portion of pulmonary flow perfused nonventilated regions. Dl and Qc returned toward initial control levels within 8 min after acceleration in most instances. lung volume during acceleration Submitted on March 1, 1965


1965 ◽  
Vol 44 (10) ◽  
pp. 1591-1599 ◽  
Author(s):  
J R Nairn ◽  
G G Power ◽  
R W Hyde ◽  
R E Forster ◽  
C J Lambertsen ◽  
...  

2019 ◽  
Vol 89 (1-2) ◽  
pp. 5-12
Author(s):  
Alon Harris ◽  
Brent Siesky ◽  
Amelia Huang ◽  
Thai Do ◽  
Sunu Mathew ◽  
...  

Abstract. Introduction: To investigate the effects of a lutein complex supplementation on ocular blood flow in healthy subjects. Materials and Methods: Sixteen healthy female patients (mean age 36.8 ± 12.1 years) were enrolled in this randomized, placebo-controlled, double-blinded, two-period crossover study. Subjects received daily an oral dose of the lutein with synergistic phytochemicals complex (lutein (10 mg), ascorbic acid (500 mg), tocopherols (364 mg), carnosic acid (2.5 mg), zeaxanthin (2 mg), copper (2 mg), with synergistic effects in reducing pro-inflammatory mediators and cytokines when administered together in combination) and placebo during administration periods. Measurements were taken before and after three-week supplementation periods, with crossover visits separated by a three-week washout period. Data analysis included blood pressure, heart rate, intraocular pressure, visual acuity, contrast sensitivity detection, ocular perfusion pressure, confocal scanning laser Doppler imaging of retinal capillary blood flow, and Doppler imaging of the retrobulbar blood vessels. Results: Lutein complex supplementation produced a statistically significant increase in mean superior retinal capillary blood flow, measured in arbitrary units (60, p = 0.0466) and a decrease in the percentage of avascular area in the superior (−0.029, p = 0.0491) and inferior (−0.023, p = 0.0477) retina, as well as reduced systolic (−4.06, p = 0.0295) and diastolic (−3.69, p = 0.0441) blood pressure measured in mmHg from baseline. Data comparison between the two supplement groups revealed a significant decrease in systemic diastolic blood pressure (change from pre- to post-treatment with lutein supplement (mean (SE)): −3.69 (1.68); change from pre- to post-treatment with placebo: 0.31 (2.57); p = 0.0357) and a significant increase in the peak systolic velocity (measured in cm/sec) in the central retinal artery (change from pre- to post-treatment with lutein supplement: 0.36 (0.19); change from pre- to post-treatment with placebo: −0.33 (0.21); p = 0.0384) with lutein complex supplement; data analyses from the placebo group were all non-significant. Discussion: In healthy participants, oral administration of a lutein phytochemicals complex for three weeks produced increased ocular blood flow biomarkers within retinal vascular beds and reduced diastolic blood pressure compared to placebo.


2020 ◽  
pp. 53-59
Author(s):  
N. O. Shushliapina ◽  
O. Ye. Cherniakova

The investigation of the vascular microcirculation system is important for diagnosis, assessment of the severity and nature of pathological processes in human body, monitoring the effectiveness of treatment. Monitoring the state of microcirculation in impaired respiratory function of the nose helps to study the subtle mechanisms of regulation of vascular−tissue relations. To do this, there were used the biomicroscopic methods to study capillary blood flow, one of the most relevant and promising is optical capillaroscopy of the nail bed. This method makes it possible to identify at the evidence level the peculiarities of the functioning of the peripheral circulatory system by the state of the capillary system and to evaluate the effectiveness of treatment by the rheological properties of blood in hematological practice. There were examined 145 patients by means of computer capillaroscopy to study the rate of capillary circulation in the patients with pathology of intranasal structures and nasal breathing disorders. All patients underwent a complete clinical examination, routine instrumental examinations, and computer capillaroscopy using a video capillaroscope with a visual magnification of up to 550 times. The obtained images were stored and processed according to a special software. During the characterization of the capillaroscopic picture there were evaluated: pathological tortuosity, change in the caliber of arterioles and venules, disorganization of the capillary network, the number of functioning capillaries. Changes in the speed and nature of capillary blood flow (accelerated, slow, stasis) were observed. The optical capillaroscopy method allows not only to visually assess the condition of microvessels, but also to determine such an important parameter as blood circulation, actually, it can replace the study of laser Doppler. Such data will be important in the diagnosis of respiratory and olfactory disorders and the formation of adequate tactics for their treatment. Key words: microcirculation, microcirculatory tract, capillary circulation, nasal obstruction, nasal breathing disorders, pathology of intranasal structures, computer capillaroscopy.


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