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PubMed1992

Isotope lung imaging.

The contribution of isotope imaging to the investigation of respiratory disease has been primarily limited to the detection of ventilation and perfusion abnormalities and the investigation of inflammation or cancer. In recent years, there has been a growing interest in the metabolic function of the lung and in measurements of alveolar capillary permeability in a variety of conditions. This review will deal with these newer applications of isotope techniques in the lung in addition to developments in ventilation-perfusion imaging.

Capillary Permeability↗
PubMed1987

Leukotriene D4 increases extravascular lung water in the dog.

The peptide leukotrienes have been detected in animals that have received endotoxin injections and also have been associated with patients suffering from the adult respiratory distress syndrome (ARDS). The ability of leukotriene D4 (LTD4) to cause pulmonary capillary permeability changes was investigated in ten anesthetized mongrel dogs. Four dogs were used as controls and six dogs received intravenous LTD4 (0.25 microgram/kg). There was a variable response in that two treated animals showed no apparent effect of LTD4. Analysis of the results from the remaining four treated animals demonstrated a significant increase in extravascular lung water (EVLW) that peaked 3 hr after LTD4 from 5.4 +/- 0.6 to 10.3 +/- 0.5 ml/kg (P less than .01). In these four dogs, EVLW increased before slight, but statistically significant, rises in pulmonary artery wedge pressure (4 +/- 1 to 9 +/- 1 mm Hg, P less than .01) and mean pulmonary artery pressure (13 +/- 1 to 17 +/- 1 mm Hg, P less than .01) occurred. During the same period, cardiac output decreased 56 +/- 7% (P less than .01), but no change in airway resistance was observed. This study is the first in vivo demonstration that LTD4 directly alters pulmonary fluid balance in the dog. We conclude LTD4 can cause increases in EVLW and may be an important mediator of the permeability changes observed in various clinical events that lead to the adult respiratory distress syndrome.

Animals↗
PubMedDate not supplied

[Mechanisms of acute pulmonary edema during meningococcal shock in children (author's transl)].

Meningococcic shocks may induce fatal acute pulmonary edemas. Ten children, who died in this condition, have been compared to 19 others, who during the treatment of the shock, developed right heart failure, without acute pulmonary edema (8 deaths, 11 survivals). The three groups of children could not be differentiated regarding their clinical status on admission, during the shock phase, or the treatments administered. Composition, volume and speed of administration of fluids were similar in the three groups. An increase in pulmonary capillary permeability could have occurred, and lead to the development of acute pulmonary failure, as presented by the children of the first group.

Acute Disease↗
PubMed1976

[Cell enzymes in lymph. Distribution and transport of cell enzymes within the extracellular space. II (author's transl)].

Enzyme patterns were measured in the lymph of the thoracic duct of the dog and in the intestinal lymph of the rat. Those patterns were compared to the corresponding activities in blood plasma. From the results it is concluded that under physiological conditions cell enzymes are released into the interstitial space and from there are transported via the lymph into the intravascular space. Only enzymes with a low molecular weight such as myokinase are able to penetrate the capillary membrane, thereby reaching the plasma without being transported exclusively by the lymph. There is a close relationship between the molecular weight of enzymes and their plasma/lymph ratios. In the rat the enzyme patterns in mesenteric lymph nodes and in intestinal mucosa and muscularis (duodenum as well as ileum) were also determined. No direct correlation between those intracellular patterns and the enzyme patterns in the intestinal lymph could be established. The significance of lymph and lymph flow for clinical enzymology is discussed with respect to physiological and pathological conditions. High sensitivity of diagnosis by means of enzyme measurements in plasma can be achieved only if the capillary permeability in the injured organ is high and/or the lymph flow from the organ is not restricted by the injury.

Animals↗
PubMed1990

Capillary filtration and ankle edema in patients with venous hypertension treated with TTFCA.

The variation of capillary filtration rate (CFR), ankle circumference (AC), and ankle edema (AE) was evaluated in three groups of patients with venous hypertension (ambulatory venous pressure greater than 42 mmHg) and in a group of normal subjects before and after treatment for four weeks with Total Triterpenic fraction of Centella Asiatica (TTFCA), a venoactive drug acting on the microcirculation and on capillary permeability. Group A (20 patients) was treated with TTFCA 60 mg tid; Group B (20 patients) was treated with 30 mg tid; Group C (12 patients) was treated with placebo; and Group D (10 normal subjects) was treated with TTFCA 60 mg tid in an open study. Capillary filtration rate was assessed by venous occlusion plethysmography, ankle edema by a new system called AECT (Ankle edema coin tester). Subjective symptoms of venous hypertension were assessed by an analogue scale line considering four symptoms: swelling sensation, restless lower extremity, pain and cramps, and tiredness. CFR, AC, and AE were significantly higher in patients in comparison with normal subjects. After four weeks of TTFCA treatment there was a significant decrease of the abnormally increased CFR, AC, and AECT time in patients. This was also greater in the higher dose group. No significant change was observed in the placebo group and in normal subjects treated with TTFCA. Symptoms were also significantly improved in the two groups treated with the active drug according to the dose. No significant changes were observed in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Pericytes augment the capillary barrier in in vitro cocultures.

UNLABELLED: Most in vitro studies of capillary permeability focus on endothelial cell (MVEC) monolayers and ignore the second cell that forms the capillary wall: the microvascular pericyte (PC). We describe a model to study the permeability characteristics of MVEC, PC, and MVEC:PC cocultures. METHODS: Semipermeable culture inserts were coated with collagen and then plated with early passage bovine pulmonary MVEC. On Day 3, bovine pulmonary PC were added at concentrations to approximate MVEC:PC ratios of 1:1, 5:1, and 10:1. Electrical resistance was measured on subsequent days and fluorescently labeled (FITC) albumin was used in a permeability assay to calculate an albumin clearance for each culture. RESULTS: The results for electrical resistance measurements and albumin assays showed a similar pattern. Resistance for endothelial cell monolayers was significantly higher and albumin permeability was significantly lower than that of controls. Addition of pericytes at a 10:1 and 5:1 ratios increased the permeability barrier compared to endothelial cells alone, although these cultures were not significantly different from one another. Cocultures at a 1:1 ratio had the best barrier, significantly better than all other cultures. CONCLUSIONS: Endothelial cell monolayers are an inadequate model of the microcirculation. As PC form a key component of the capillary wall in vivo and as addition of PC to MVEC monolayers in vitro, optimally at a 1:1 ratio, increase their barrier effect to large and small molecules, we believe it is necessary to include both cells in future in vitro studies.

Albumins↗
PubMed1998

Angiotensin-converting enzyme inhibition does not correct early defects in renal and vascular permeability in diabetes mellitus.

1. In diabetes mellitus a selective increase in the excretion of albumin generally precedes the occurrence of demonstrable loss of glomerular size-selectivity. However, even in this (microalbuminuric) phase of diabetic nephropathy a defect in glomerular barrier function can be demonstrated during infusion of atrial natriuretic peptide. 2. The aim of this study was to investigate whether angiotensin-converting enzyme inhibition could prevent the proteinuric response to atrial natriuretic peptide in these patients. We performed infusions of atrial natriuretic peptide (0.01 microgram min-1 kg-1) in 10 patients with insulin-dependent diabetes mellitus and microalbuminuria (urinary albumin excretion 90 +/- 44 mg/day), both before and after 1 month of treatment with enalapril (20 mg once daily). 3. Despite a 40% reduction in proteinuria, angiotensin-converting enzyme inhibition did not prevent the atrial natriuretic peptide-induced increase in protein excretion. Both before and during angiotensin-converting enzyme inhibition, atrial natriuretic peptide infusion resulted in a significant increase in the fractional excretion of large dextran molecules, which is compatible with an increase in flow through large unrestrictive 'shunt' pores. Atrial natriuretic peptide infusion also induced an increase in the transcapillary escape rate of albumin and angiotensin-converting enzyme inhibition also failed to prevent this effect of atrial natriuretic peptide on peripheral capillary permeability. 4. We conclude that angiotensin-converting enzyme inhibition during 1 month does not correct the capillary barrier function defect in patients with diabetes mellitus and microalbuminuria that is unmasked by atrial natriuretic peptide infusion.

Albuminuria↗
PubMed1984

Effects of histamine, serotonin, and norepinephrine on circulation of dog lungs.

The action of histamine (H), serotonin (5-HT), and norepinephrine (NE) on the lung vasculature was evaluated in isolated blood-perfused dog lung lobes using isogravimetric techniques. Pre- and postcapillary resistances, isogravimetric capillary pressure (Pc,i), capillary filtration pressure (Pc,f), capillary filtration coefficient (Kf,c), and vascular pressure-volume relationships were measured. For constant-flow conditions, all drugs induced marked increases in both pre- and postcapillary resistances and increased Pc,f. The rise in Pc,f was most pronounced for H and least marked for NE and 5-HT. For constant-pressure perfusion, Pc,f increased slightly for H but not for NE and 5-HT, while total vascular resistance increased 4-5 times for all drugs. Vascular distensibility and volumes decreased markedly for NE and 5-HT but only slightly for H. None of the drugs appeared to alter capillary permeability because Kf,c and Pc,i measured during the infusions were not different from control.

Animals↗
PubMed1999

Evidence of a central role for p38 map kinase induction of tumor necrosis factor alpha in pancreatitis-associated pulmonary injury.

BACKGROUND: Tumor necrosis factor alpha (TNF alpha) has been implicated as an important mediator in acute pancreatitis-associated adult respiratory distress syndrome, but the precise pathogenesis remains unclear. The purpose of this work was to clarify the role of TNF alpha that is produced within the lung parenchyma in the inducement of pancreatitis-related pulmonary injury and to examine 1 of the potential pathways leading to the production of pulmonary TNF alpha. METHODS: Bile salt pancreatitis was induced in rats (n = 40) that were randomized to receive a p38 mitogen-activated protein (MAP) kinase inhibitor or vehicle. A separate group (n = 16) underwent sham operation. Pulmonary capillary permeability was determined with fluorescein isothiocyanate-labeled albumin and Evans blue dye, and lung histologic analysis was performed. TNF alpha protein was measured in bronchoalveolar lavage fluid, and p38 MAP kinase was activity determined by Western blot analysis. RESULTS: The induction of pancreatitis resulted in increased pulmonary capillary leakage and worsened histologic condition (P < .01 vs sham). Effective inhibition of p38 MAP kinase-induced TNF alpha production completely prevented pancreatitis-associated pulmonary injury (P < .01 vs vehicle). CONCLUSIONS: p38 MAP kinase-induced TNF alpha production plays a central role in the development of pulmonary dysfunction, which accompanies severe acute pancreatitis in this rodent model.

Acute Disease↗
PubMed1987

[Effect of treatment with trental on indicators of peripheral hemodynamics and blood lipid level in patients with arteriosclerosis of the lower extremities].

Rheovasographic parameters of lower-limb regional blood flow, and lipid metabolism were assessed in 35 trental-treated patients with lower-limb arterial atherosclerosis and in 40 normal subjects. Blood volume increased, and vascular tonicity and elasticity improved in the affected limbs following treatment. Activated transcapillary metabolism is reflected in increased capillary permeability and lymph microflow rate, accompanied with a transition of plasma cholesterol ethers from liquid crystalline to isotropic state.

Arteriosclerosis↗
PubMed1981

[Unilateral pulmonary oedema after re-expansion (author's transl)].

The authors report three cases of unilateral pulmonary oedema following the re-expansion of a spontaneous pneumothorax. The importance of the duration of the pneumothorax and the use of too negative pressure while re-expanding the lung were both underlined. The different physiopathological hypotheses responsible for the appearance of pulmonary oedema were discussed, notably altered mechanical properties of the lung and alveolar-capillary permeability. The numerous precautions to take to avoid the appearance of oedema, as well as the therapeutic measures to adopt for severe pulmonary oedema were reviewed.

Adult↗
PubMed1987

Interstitial fluid of isolated perfused rat hearts: glucose and lactate concentration.

Interstitial fluid (IF) emerging at the ventricular surface of isolated perfused rat hearts was collected and assayed for rate of production, protein content, glucose and lactate concentration. The influence of four perfusion media was investigated during an experimental period of 150 min: Krebs-Henseleit solution (KH) containing glucose (5.5 mM); KH containing glucose and pyruvate (2 mM); Hypoxic KH (20% O2), substrates as 2; KH containing isoprenaline (8 X 10(-9) M), substrates as 2. Interstitial fluid was produced at a rate of 20 to 100 microliters/min/gww and contained proteins (0.5 to 3 g/l). Interstitial glucose concentration was lower than venous concentration by up to 50%. Interstitial lactate concentration was higher by up to 600%. Permeability X surface area products of glucose calculated from transcapillary concentration differences and transfer rates were different depending on experimental conditions, but were within the rather large range of P X S values for molecules of similar size obtained by other authors. Those of lactate were higher by a factor of 3 to 9 and can be interpreted to be influenced by the metabolic activity of the endothelium. The results demonstrate that interstitial substrate concentration can differ very markedly from intravascular concentration and cannot be estimated reliably without assay of the interstitial fluid. Capillary permeability seems to be variable under the experimental conditions of this study.

Animals↗
PubMed1993

Idiopathic capillary leak syndrome complicated by massive rhabdomyolysis.

Idiopathic systemic capillary leak syndrome (Clarkson's disease) is characterized by recurring attacks of increased capillary permeability, resulting in severe hypovolemic shock due to plasma extravasation. Additional laboratory features include association with a monoclonal gammopathy, extreme hemoconcentration, and hypoalbuminemia. Rare manifestations of this syndrome are renal damage and rhabdomyolysis due to increased compartment pressure and ischemic myonecrosis. We present the findings in two patients with capillary leak syndrome complicated by severe rhabdomyolysis, in one case leading to acute renal failure. We review therapeutic aspects of this rare syndrome and emphasize the importance of early diagnosis and of prompt and aggressive fluid replacement.

Acute Kidney Injury↗
PubMed1989

Diagnostic criteria for adult respiratory distress syndrome: time for reappraisal.

To assess whether current diagnostic criteria for the adult respiratory distress syndrome (ARDS) may limit research to patients with a range of severity of respiratory failure and risk factors for ARDS were studied. In 28 patients ARDS did not develop; in 9 it did; and the other 13 met the diagnostic criteria at their first assessment. Plasma concentration of neutrophil elastase-alpha 1-antitrypsin complex was higher in all groups than in controls. For all patients, plasma elastase-complex was related to worsening hypoxia and to increased bronchoalveolar lavage protein content. Elastase-complex was present in all bronchoalveolar lavage samples and was related to protein content and differential neutrophil counts. Patients at risk of or with ARDS had a spectrum of respiratory failure to which intravascular and intra-alveolar neutrophil elastase release and capillary permeability were related. This suggests that the state recognised as ARDS is not a distinct pathophysiological entity.

Adult↗
PubMed2001

Treatment of edema and increased capillary filtration in venous hypertension with total triterpenic fraction of Centella asiatica: a clinical, prospective, placebo-controlled, randomized, dose-ranging trial.

The variation of capillary filtration rate (CFR), ankle circumference (AC), and ankle edema (AE) was evaluated in three groups of patients with venous hypertension (ambulatory venous pressure >42 mm Hg) and in a group of normal subjects before and after treatment for 4 weeks with total triterpenic fraction of Centella asiatica (TTFCA), a venoactive drug acting on the microcirculation and on capillary permeability. Group A (20 patients)was treated with TTFCA 60 mg thrice daily, group B (20 patients) was treated with 30 mg thrice daily; group C (12 patients) was treated with placebo; and group D (10 normal subjects) was treated with TTFCA 60 mg thrice daily in a randomized study. Capillary filtration rate was assessed by venous occlusion plethysmography, ankle edema by a new system called AET (ankle edema tester). Subjective symptoms of venous hypertension were assessed by an analogue scale line considering four symptoms: swelling sensation, restless lower extremity, pain and cramps, and tiredness. CFR, AC, and AE were significantly higher in patients in comparison with normal subjects. After 4 weeks of TTFCA treatment, there was a significant decrease of CFR, AC, and AET time in patients. This was also greater in the higher dose group. No significant change was observed in the placebo group and in normal subjects treated with TTFCA. Symptoms were also significantly improved in the two groups treated with the active drug according to the dose. No significant changes were observed in the placebo group. In conclusion, the improvement of signs and symptoms by TTFCA observed in patients with venous hypertension was well correlated with the improvement of CFR and ankle edema. Dose ranging showed that 180 mg/day is more effective in improving symptoms and CFR.

Adult↗
PubMed2003

Very early expression of vascular endothelial growth factor in brain oedema tissue associated with brain contusion.

BACKGROUND: Brain oedema associated with cerebral contusion can be life-threatening. Mechanisms of the development of brain oedema are still unclear. METHOD: We investigated the expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 (KDR/Flk-1) in the contusional brain tissue obtained during neurosurgery from 5 patients. FINDINGS: VEGF is expressed in some but not all the astrocytes, and KDR/Flk-1 is expressed in vascular endothelial cells in the con-tusional tissue as early as 3 hours after onset. CONCLUSION: The results suggested that the VEGF is induced in the contusional tissue in the very early period after onset, and that it increases capillary permeability via KDR/Flk-1 resulting in vasogenic type brain oedema.

Adolescent↗