251
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Barbero JM, Ezpeleta AI, López Gil M, Barroso JL, García-Cosío F. [Severe hypoxemia due to a right-left shunt at the level of the foramen ovale. A complication of right ventricular infarct]. Rev Esp Cardiol 1991; 44:485-7. [PMID: 1759030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A 76-year-old woman with an inferior wall myocardial infarction, with right ventricular involvement, developed severe arterial hypoxemia with neurological involvement. Pulmonary edema or embolism and chronic obstructive pulmonary disease were ruled-out, and a right-to-left shunt was demonstrated by contrast echocardiography at the level of the foramen ovale. After inotropic support and oxygen supplementation, the patient recovered, although with significant neurological sequelae. No focal lesions were detected in the central nervous system by computerized tomography. Hypoxemia improved, coinciding with the disappearance of right-to-left shunt by contrast echocardiography.
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252
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Aparicio Otero O, Romero Gutierrez F, Harris P, Anand I. Echocardiography shows persistent thickness of the wall of the right ventricle in infants at high altitude. CARDIOSCIENCE 1991; 2:63-9. [PMID: 1888881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have applied M-mode and two-dimensional echocardiography to infants living at high altitude in La Paz, Bolivia (3800m) and infants living at low altitude in Santa Cruz, Bolivia (400m). At low altitude, the thickness of the anterior wall of the right ventricle decreases during the first month of extrauterine life to a dimension which remains constant for the rest of infancy. At high altitude, the thickness of the anterior wall of the right ventricle at birth is similar to that found at low altitude but does not decrease in the succeeding twelve months. The ratio of the diameter of the aorta to that of the pulmonary artery was higher at low altitude in all age-groups. The observations are consistent with the persistence of a high pulmonary arterial pressure during infancy at high altitude.
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253
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Hurford WE, Crosby G, Strauss HW, Jones R, Lowenstein E. Ventricular performance and glucose uptake in rats during chronic hypobaric hypoxia. J Nucl Med 1990; 31:1344-51. [PMID: 2384802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To identify changes of ventricular performance and their relationship to myocardial glucose uptake in Sprague-Dawley rats exposed to hypobaric hypoxia, radionuclide angiocardiograms (n = 34) and 2-[14C]deoxyglucose (2-[14C]DG) autoradiography (n = 14) were performed on rats maintained either for two weeks in air at 380 mmHg (hypoxic group), two weeks in hypobaric hypoxia followed by two weeks of air (recovered group), or in air (control group). Right ventricular ejection fraction (RVEF) was 66% +/- 2% (mean +/- s.e.m.) in controls, 40% +/- 3% during hypoxia, and 60% +/- 2% in recovered rats. LVEF remained unchanged. In controls, RV 2-[14C]DG uptake was 77% +/- 3% of LV uptake. During hypoxia, 2-[14C]DG uptake increased. This increase was greater within the RV than the LV and septum (85 +/- 16% versus 51 +/- 10%, p less than 0.005). The alterations of RV 2-[14C]DG uptake correlated with systolic pulmonary artery pressure (r = 0.77, p = 0.002).
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254
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DeVolder AG, Goffinet AM, Bol A, Michel C, de Barsy T, Laterre C. Brain glucose metabolism in postanoxic syndrome. Positron emission tomographic study. ARCHIVES OF NEUROLOGY 1990; 47:197-204. [PMID: 2302091 DOI: 10.1001/archneur.1990.00530020103022] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Thirteen positron emission tomographic studies of cerebral glucose utilization were carried out in 12 patients with postanoxic syndrome due to cardiac arrest. Seven subjects were in a persistent vegetative state. The 5 other subjects were normally conscious, but disclosed focal neurological signs. When compared with normal values, mean cerebral glucose metabolism was drastically decreased (+/- 50%) in vegetative subjects, and to a lesser degree (+/- 25%) in conscious patients. The most consistent regional alterations were found in the parieto-occipital cortex (9 cases), the frontier between vertebral and carotid arterial territories, followed by the frontomesial junction (5 cases), the striatum (3 cases with dystonia), thalamus (2 cases), and visual cortex (2 cases with cortical blindness). These data suggest that brain anoxia can result in global brain hypometabolism, which appears related to the vigilance state, as well as in regional alterations preferentially located in arterial border zones.
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255
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Richalet JP, Merlet P, Bourguignon M, Le-Trong JL, Kéromès A, Rathat C, Jouve B, Hot MA, Castaigne A, Syrota A. MIBG scintigraphic assessment of cardiac adrenergic activity in response to altitude hypoxia. J Nucl Med 1990; 31:34-7. [PMID: 2295937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
High altitude hypoxia induces a decrease in the cardiac chronotropic function at maximal exercise or in response to isoproterenol infusion, suggesting an alteration in the cardiac sympathetic activation. Iodine-123 metaiodobenzylguanidine [( 123I]MIBG) was used to map scintigraphically the cardiac sympathetic neuronal function in six male subjects (aged 32 +/- 7 yr) after an exposure to high altitude that created hypoxic conditions. Results obtained just after return to sea level (RSL) were compared with the normal values obtained after 2 or 3 mo of normoxia (N). A static image was created as the sum of the 16-EKG gated images recorded for 10 min in the anterior view of the chest at 20, 60, 120, and 240 min after injection. Regions of interest were located over the heart (H), lungs (L), and mediastinum (M) regions. There was a significant decrease in the H/M and the L/M ratios in RSL compared to N condition. Plasma norepinephrine concentration was elevated during the stay at altitude but not significantly different in RSL compared to N. In conclusion, cardiac [123I]MIBG uptake is reduced after an exposure to altitude hypoxia, supporting the hypothesis of an hypoxia-induced reduction of adrenergic neurotransmitter reserve in the myocardium. Furthermore, the observed significant decrease in pulmonary MIBG uptake suggests an alteration of endothelial cell function after exposure to chronic hypoxia.
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256
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Vock P, Fretz C, Franciolli M, Bärtsch P. High-altitude pulmonary edema: findings at high-altitude chest radiography and physical examination. Radiology 1989; 170:661-6. [PMID: 2916019 DOI: 10.1148/radiology.170.3.2916019] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Twenty-five male volunteers underwent chest radiography at 550 m above sea level (baseline) and at 4,559 m at 6, 18, and 42 hours after arrival. Nine had a history of high-altitude pulmonary edema (HAPE). Starting by 6 hours and independent of the consecutive presence of HAPE, the diameters of the central pulmonary arteries increased by 10%-30% at 4,559 m. At 18 hours and, increasingly, at 42 hours, radiographic evidence of HAPE developed in eight subjects: six with previously documented HAPE and two without. Radiographic signs of HAPE were most severe peripherally, and morphologic characteristics were compatible with permeability and/or overperfusion edema and normal pulmonary venous pressure. Extensive radiographic findings were accompanied by discrete pulmonary rales, and chest radiography proved valuable in detecting HAPE in subjects with normal findings of lung auscultation. This study demonstrates a significant individual susceptibility of lowland residents with a history of HAPE to develop HAPE, resulting in a recurrence rate of 66%.
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257
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Shelton ME, Dence CS, Hwang DR, Welch MJ, Bergmann SR. Myocardial kinetics of fluorine-18 misonidazole: a marker of hypoxic myocardium. J Nucl Med 1989; 30:351-8. [PMID: 2738664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Fluoromisonidazole, a member of a class of compounds referred to as "hypoxic sensitizers," accumulates in hypoxic, viable tumor cells. We hypothesized that it might therefore accumulate also in ischemic, but non-necrotic myocardium potentially salvageable by interventional therapy. To evaluate the myocardial kinetics of [18F]fluoromisonidazole (FM), 20 isolated perfused rabbit hearts were used to characterize the uptake and binding of tracer under control conditions (n = 6), or with ischemia (flow 10% of control, n = 5), hypoxia without low flow (control flow rates with hypoxic medium, n = 5), or with reperfusion (n = 4). Myocardial retention of tracer detected externally with gamma scintillation probes after 20 min of constant [18F]FM infusion followed by 20 min of washout with nonradioactive buffer was 41 +/- 7% and 46 +/- 8% of peak activity in hearts subjected to ischemia or hypoxia, respectively, and significantly higher than in hearts subjected to either control perfusion or to ischemia followed by reperfusion (18 +/- 6 and 16 +/- 5% of peak activity, respectively, p less than 0.01). The biologic half-time of retained tracer was 40 hr in all hearts indicating essentially irreversible binding. Based on these findings, we measured uptake of [18F]FM using positron emission tomography in five dogs subjected to acute coronary occlusion. Five to thirteen millicuries of tracer were injected within 3 hr of occlusion. Within 30 min after administration of tracer, 18F accumulation in ischemic myocardium was greater than that observed in normal myocardium. The results indicate that [18F]FM accumulates in ischemic myocardium in relation to diminished tissue oxygen content and not simply because of diminished flow. Thus, this class of compounds may be potentially useful to help identify hypoxic myocardium.
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258
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Smith DE, McLuckie A, Wyatt J, Gazzard B. Severe exercise hypoxaemia with normal or near normal X-rays: a feature of Pneumocystis carinii infection. Lancet 1988; 2:1049-51. [PMID: 2903279 DOI: 10.1016/s0140-6736(88)90066-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To find out whether Pneumocystis carinii pneumonia (PCP) can be detected while still in an early phase by the degree of exercise-induced oxygen desaturation, arterial oxygen saturation was measured by continuous pulse oximetry in patients positive for antibody to the human immunodeficiency virus and clinically suspected of having PCP, in patients with other chest diseases, and in controls. Among patients with proven PCP 94% of those with low arterial oxygen pressures (PaO2) showed desaturation on exercise oximetry, as did 80% of those with a normal oxygen pressure at rest, whereas only 10% of patients with other chest disorders and HIV disease showed significant desaturation.
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259
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Levine SJ, White DA, Fels AO. An abnormal chest radiograph in a patient with recurring high altitude pulmonary edema. Chest 1988; 94:627-8. [PMID: 3409746 DOI: 10.1378/chest.94.3.627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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260
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Rasey JS, Grunbaum Z, Magee S, Nelson NJ, Olive PL, Durand RE, Krohn KA. Characterization of radiolabeled fluoromisonidazole as a probe for hypoxic cells. Radiat Res 1987; 111:292-304. [PMID: 3628717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Radiolabeled fluoromisonidazole has been characterized as a probe for hypoxic cells in vitro and in vivo. The uptake and retention of [3H]fluoromisonidazole and [3H]misonidazole were compared in V-79 cell monolayers and spheroids by varying incubation time and O2 levels in contact with the medium. The two labeled drugs were retained similarly in cell populations isolated from different depths in spheroids, and the amount of each drug bound in cells at the spheroid periphery increased with decreasing O2 level. The labeling patterns in autoradiographs were similar for spheroids incubated with the two labeled drugs, with most silver grains located over a zone of viable and presumed hypoxic cells intermediate between the necrotic center and the periphery of the spheroid. Biodistribution of the two tritiated drugs was compared in C3H mice bearing KHT tumors with 15% radiobiologically hypoxic cells. Tumor:blood and tumor:muscle ratios greater than 5.0 were achieved in mice sacrificed 4 h after the last of three injections of 5 or 20 mumol/kg of [3H]fluoromisonidazole. These ratios are compatible with imaging and are higher than those obtained with 50 mumol/kg misonidazole in a similar administration protocol. TLC analysis of plasma from mice injected with [3H]fluoromisonidazole indicated that the drug was stable in vivo for up to 2 h and that the metabolites formed were too polar to be dehalogenation products. Fluoromisonidazole labeled with 18F at the end of the alkyl side chain would retain the label on metabolites that bind in hypoxic cells in vivo. Fluoromisonidazole binds stably in the same populations of hypoxic cells as does misonidazole, and we conclude that [18F]fluromisonidazole has potential use as a hypoxia imaging agent in vivo.
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261
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Arshad M, Braun SR, Sunderrajan EV. Severe hypoxemia in farmer's lung disease with normal findings on chest roentgenogram. Chest 1987; 91:274-5. [PMID: 3802943 DOI: 10.1378/chest.91.2.274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A 33-year-old woman farmer developed an acute episode of fever, cough, and shaking chills with persistent shortness of breath. Her PaO2 was 51 with a restrictive pattern on pulmonary function. Her diffusion capacity was 36 percent of predicted. In spite of these abnormalities, she always had normal chest roentgenographic findings. Further studies, including a lung biopsy, led to the diagnosis of farmer's lung disease.
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262
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Grunbaum Z, Freauff SJ, Krohn KA, Wilbur DS, Magee S, Rasey JS. Synthesis and characterization of congeners of misonidazole for imaging hypoxia. J Nucl Med 1987; 28:68-75. [PMID: 3794812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Misonidazole is a known hypoxic cell sensitizer that binds covalently in hypoxic cells. Its congeners labeled with 77Br, 75Br, or 18F, are likely candidates for imaging hypoxia. We have synthesized and tested [82Br]-4-bromomisonidazole, [3H]-4-bromomisonidazole, [3H]fluoromisonidazole and [3H]misonidazole as prototype radiopharmaceuticals and have compared their uptake in normal and malignant tissues. The higher lipophilicity of brominated misonidazole increased its concentration in the hypoxic portion of tumors at 2 hr, but high blood levels contributed to excessive background, incompatible with imaging. Hydrogen-3-fluoromisonidazole diffused into tumors at a slower rate than misonidazole but it also cleared from normal tissues so that after 2 hr tumor-to-blood ratios favorable for imaging were achieved. In the compounds that were studied, fluorine at the end of the alkyl chain is more stable in vivo than bromine on the imidazole ring. Our results indicate that [18F] fluoromisonidazole may be a useful tracer for imaging hypoxia at approximately 4 hr after injection.
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263
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Maini CL, Antonelli Incalzi RA, Bonetti MG, Valle G. The effects of chronic hypoxia on left ventricular peak filling rate evaluated by equilibrium radionuclide angiocardiography. Nucl Med Commun 1986; 7:705-11. [PMID: 3774264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Left ventricular peak filling rate (PFR) was measured by equilibrium radionuclide angiocardiography (ERNA) in 15 patients with Stage II stabilized chronic respiratory failure (CRF) without evidence of coexisting heart diseases and in 18 patients with coronary artery disease (CAD) without myocardial infarction. The study was designed to assess the effects of severe hypoxia and of ischaemia on the calcium-dependent early diastolic filling. PFR was found to be impaired in both groups of patients (mean = 1.72 EDVs-1 and S.E.M. = 0.07 in CAD; mean = 2.35 EDVs-1 and S.E.M. = 0.14 in CRF) but significantly less (p less than 0.001) in CRF patients while the left ventricular ejection fraction (LVEF) values were not significantly different between the two groups (mean = 60.0% and S.E.M. = 1.4 in CAD; mean = 62.0% and S.E.M. = 1.6 in CRF). As PFR is known to be a sensitive index of left ventricular performance the results obtained in this human model are consistent with findings obtained in animal models suggesting that hypoxia is less efficient than ischaemia in depressing left ventricular function.
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264
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Shirai M, Sada K, Ninomiya I. Effects of regional alveolar hypoxia and hypercapnia on small pulmonary vessels in cats. J Appl Physiol (1985) 1986; 61:440-8. [PMID: 3091565 DOI: 10.1152/jappl.1986.61.2.440] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Using an X-ray TV system, we analyzed responses in the internal diameter (ID), flow velocity, and volume flow in small pulmonary vessels (100-600 microns ID) during unilobar hypoxia and hypercapnia in cats. In the hypoxic and hypercapnic lobes, the ID reduced in proportion to the degree of hypoxia and hypercapnia, respectively. The ID reduction was larger in the arteries than in the veins for a given stimulus. In the arteries, the ID reduced nonuniformly in the series-arranged vessels in response to both stimuli. The percentage ID reduction was maximal in the arteries of 200-300 microns ID, in which it was 21, 26, 28, and 36% with 5% O2, 0% O2, 5% CO2, and 10% CO2 inhalations, respectively. On the other hand, in the veins, uniform ID reduction occurred for a given stimulus. In the contralateral normoxic lobe, the ID did not change significantly. In both hypoxic and hypercapnic lobes, the flow velocity and volume flow of the small arteries decreased, with 5% O2, by 18 and 40%, respectively, and, with 5% CO2, by 23 and 50%, respectively. In contrast, in the normoxic lobe, they increased significantly during 5% O2 and 5% CO2 inhalations. We concluded that regional alveolar hypoxia and hypercapnia induced a local vasoconstriction particularly in the small arteries of 200-300 microns ID and decreased the flow velocity and volume flow in the same lung region.
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265
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Schuster DP, Marklin GF. The effect of regional lung injury or alveolar hypoxia on pulmonary blood flow and lung water measured by positron emission tomography. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1986; 133:1037-42. [PMID: 3487264 DOI: 10.1164/arrd.1986.133.6.1037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We measured regional pulmonary blood flow (rPBF) and extravascular lung water (rEVLW) with positron emission tomography (PET) before and after a lobar lung injury induced by oleic acid in dogs. Changes in rPBF after injury were also compared with those observed after alveolar hypoxia limited to a similar volume of lung. Positron emission tomography techniques for measuring rPBF correlated well with microsphere methods, even in areas of low blood flow (R2 = 0.88). After lung injury, rPBF decreased by 54% from its control value, compared with a 36% decrease in response to alveolar hypoxia. This difference was significant (p less than 0.05). Changes in oxygenation after injury correlated significantly with residual blood flow in the injured area (R2 = 0.69) but not with rEVLW. These data suggest that mechanisms other than hypoxic vasoconstriction may affect rPBF after lung injury, and that individual variation in rPBF to the injured area will have an important influence on oxygenation.
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266
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Finlay M, Barer GR, Suggett AJ. Quantitative changes in the rat pulmonary vasculature in chronic hypoxia--relation to haemodynamic changes. QUARTERLY JOURNAL OF EXPERIMENTAL PHYSIOLOGY (CAMBRIDGE, ENGLAND) 1986; 71:151-63. [PMID: 3714956 DOI: 10.1113/expphysiol.1986.sp002975] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The anatomical basis of resistance and compliance changes of the pulmonary arterial bed was studied in rats exposed to chronic hypoxia (10% O2, 3 weeks) and the findings were compared with those of normoxic rats. The lungs were perfused with a Ba-gelatine mixture at different pressures and studied by radiology and histology. The diameter of the pulmonary arteries (greater than 0.5 mm), measured from X-rays, was less in chronically hypoxic than normoxic rats when filled at the same perfusion pressure. Diameters increased in both groups with increasing perfusion pressure but at a given pressure those of chronically hypoxic rats were always smaller than those of normoxic rats. We found evidence that arterial length was increased in chronically hypoxic rats. Arterioles of 50 micron or less in diameter adjacent to gas exchange units were of similar external diameter in normoxic and chronically hypoxic rats, but most of the latter had developed a muscular coat and a second elastic lamina internal to the single elastic lamina of control arterioles. These changes reduced the lumen by an estimated 10-14% and would increase pulmonary arteriolar resistance in chronically hypoxic rats, resulting in a changed pressure profile. We found no evidence of arteriolar loss in chronically hypoxic rats although at a given pressure, the Ba-gelatine mixture penetrated less far for reasons which are discussed.
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267
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Jerabek PA, Patrick TB, Kilbourn MR, Dischino DD, Welch MJ. Synthesis and biodistribution of 18F-labeled fluoronitroimidazoles: potential in vivo markers of hypoxic tissue. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART A, APPLIED RADIATION AND ISOTOPES 1986; 37:599-605. [PMID: 3021662 DOI: 10.1016/0883-2889(86)90079-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Three 18F labeled fluoronitroimidazoles have been prepared as potential in vivo markers of hypoxic cells in tumors, and ischemic areas of the heart and brain. 1-(2-Nitroimidazolyl)-3-[18F]fluoro-2-hydroxypropanol (18F]fluoro-normethoxymisonidazole) 4, 1-(2-[18F]fluoroethyl)-2-nitroimidazole 7, and 1-(2-[18F]-fluoroethyl)-2-methyl-5-nitroimidazole ([18F]fluoro-norhydroxymetronidazole) 10 were prepared in average radiochemical yields of less than 1%, 23% and 15-43% (8% at the no carrier-added level) respectively at end-of-synthesis. The in vivo biodistribution in rats was determined for each of the 18F labeled fluoronitroimidazoles. At 1 and 3 h after administration, the tissue distribution of each of the 18F labeled nitroimidzaoles was quite uniform and consistent with that of nitroimidazoles previously studied. These results suggest the need for a suitable animal model to evaluate their potential as in vivo markers of hypoxic tissue in the brain.
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268
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Sibbald WJ, Short AI, Driedger AA, Wells GA. The immediate effects of isosorbide dinitrate on right ventricular function in patients with acute hypoxemic respiratory failure. A combined invasive and radionuclide study. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1985; 131:862-8. [PMID: 4003937 DOI: 10.1164/arrd.1985.131.6.862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We administered 20 mg of isosorbide dinitrate sublingually to 16 patients with acute hypoxemic respiratory failure (ARF) complicated by pulmonary artery hypertension (PAH) and evaluated its effects 20 to 30 min later using a combination of invasively measured pressures and flows and ECG-gated cardiac scintigraphy. We measured the right and left ventricular ejection fractions and a simultaneous thermodilution stroke volume index; we then calculated respective end-diastolic (EDVI) and end-systolic (ESVI) volume indexes. An initially depressed mean right ventricular ejection fraction (RVEF) increased modestly after the administration of isosorbide dinitrate (35 +/- 10 to 41 +/- 10%; p less than 0.02), whereas both the mean right ventricular end-diastolic (-27 +/- 50 ml/M2; p less than 0.04) and end-systolic (-27 +/- 44 ml/M2; p less than 0.03) volume indexes fell. The RVEF increased in 11 of 16 patients: within this subgroup, a decrease in the RVEDVI and RVESVI was associated with a decrease in both cardiac index (delta 0.3 L/min/M2) and LVEDVI (delta -15 +/- 21 ml/M2; p less than 0.01); hence, O2 delivery also fell (delta -36 +/- 56 ml/min/M2; p less than 0.05). In some patients with ARF complicated by PAH, sublingually administered nitrates may improve right ventricular systolic function when globally depressed. However, left ventricular "pump" function appears to be depressed when a concurrent depression in right ventricular "pump" function ensues.
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269
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Semple PD, Macpherson P. Radiological pituitary fossa changes in chronic bronchitis. Thorax 1982; 37:512-5. [PMID: 7135292 PMCID: PMC459357 DOI: 10.1136/thx.37.7.512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Fourteen male patients with chronic bronchitis and hypoxia had a lateral radiograph of the pituitary fossa. Nine of the 14 had definite or probable abnormalities, a significantly higher frequency (p less than or equal to 0.01) than is represented by the two out of 14 age-matched men from a control group with head injuries. The most common change was thinning or erosion of the lamina dura. Patients with hypercapnia were no more prone to such abnormalities than were those with normocapnia, a finding that conflicts with a previous paper. We confirm that radiological pituitary fossa changes do occur in chronic bronchitis, that they are unrelated to steroid treatment, and that they are probably not solely due to the chronically raised intracranial pressure associated with hypercapnia. Other possible mechanisms are discussed--in particular hypoxia, which might produce changes on account of the increased cerebral blood flow and engorged intracranial blood vessels.
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270
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Langer R, Langer M, Schumacher KA. [Visualization of intrapulmonary arteriovenous shunts particularly via chest CT (author's transl)]. ROFO-FORTSCHR RONTG 1982; 136:563-6. [PMID: 6212504 DOI: 10.1055/s-2008-1056102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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271
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Nelson MD, Thompson JR, Hinshaw DB, Hasso AN. Radiodense dural sinuses: new CT sign in patients at risk for hypoxemic insult. AJNR Am J Neuroradiol 1981; 2:545-8. [PMID: 6797279 PMCID: PMC8335254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The observation of apparent dural sinus opacification in a polycythemic patient with cerebral infarction prompted a review of 300 computed tomographic scans for the significance of dense dural sinuses. Fifteen patients including 11 neonates, were identified; each of them had dense dural sinuses and elevated hematocrit or red blood cell indices or both. With only one exception, computed tomography also showed various low attenuation parenchymal abnormalities. A typical cerebral infarction pattern was seen in six and parenchymal hemorrhage in one. Nonthrombotic dural sinus opacification is a sign of increased blood viscosity in patients with congenital heart disease, hemoconcentration states, polycythemia of the newborn, and polycythemia rubra vera. These patients are at high risk for hypoxemic cerebral insult, which can be detected by cranial computed tomography.
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272
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Allison DJ, Stanbrook HS. 1979 George Simon Memorial Fellowsip Award. A radiologic and physiologic investigation into hypoxic pulmonary vasoconstriction in the dog. Invest Radiol 1980; 15:178-90. [PMID: 7399842 DOI: 10.1097/00004424-198005000-00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We examined the site and mechanism of hypoxic vasoconstriction in a single lobe of the dog lung. In anesthetized dogs pulmonary arteriography in an exteriorized lung lobe showed vasoconstriction during hypoxia. The vasoconstriction was maximal in the smallest vessels studied (300-micrometer diameter), in which a 19% reduction in diameter was observed during hypoxia; no significant change in caliber occurred in vessels exceeding 2 mm in diameter. Reversal of the vascular response occurred upon withdrawal of the hypoxic stimulus. In a second study using the same model, saralasin acetate, a specific competitive antagonist of angiotensin II, failed to modify the constrictor response to hypoxia. It is concluded from these studies that the site of the increased pulmonary vascular resistance evoked by alveolar hypoxia is located predominantly in the small pulmonary arteries, and that angiotensin II plays no significant role in the mediation of the response.
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273
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Henry E, Bomsel F. Refractory hypoxia in full-term neonates; value of radiological examinations. ANNALES DE RADIOLOGIE 1980; 23:175-85. [PMID: 7369682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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274
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Grant JL, Naylor RW, Crandell WB. Bronchial adenoma resection with relief of hypoxic pulmonary vasoconstriction. Chest 1980; 77:446-9. [PMID: 7357953 DOI: 10.1378/chest.77.3.446] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Experimental airway obstruction is known to cause reflex pulmonary artery constriction, but clinical documentation of reversible bronchial obstruction and vasoconstriction is rare. A soft bronchial adenoma obstructed the left main bronchus, and scans showed minimal ventilation and perfusion on the left. Gas aspirated from beyond the tumor was hypoxic. The adenoma was removed and the lung left intact by means of a skin graft in the bronchial wall. Four months later, pulmonary function was normal, and both ventilation and perfusion of the left lung were normal. Reflex pulmonary vasoconstriction resulting from alveolar hypoxia minimizes systemic hypoxemia and also minimizes alveolar tissue hypoxia in the lung itself. The reflex is seen most frequently in perfusion scans in patients with chronic airways disease. This case in important in that it documents reversal of vasoconstriction after ventilation was restored.
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Yu MY. [X-ray analysis of 40 cases of high altitude heart disease of adult (comparative analysis of 40 cases of chronic cor pulmonale) (author's transl)]. ZHONGHUA FANG SHE XUE ZA ZHI CHINESE JOURNAL OF RADIOLOGY 1980; 14:21-5. [PMID: 6451373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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