In vivo transtracheal adenovirus-mediated transfer of human interleukin-10 gene to donor lungs ameliorates ischemia-reperfusion injury and improves early posttransplant graft function in the rat

We examined the effect of adenovirus-mediated transtracheal transfer of the human interleukin 10 (hIL-10) gene on lung ischemia-reperfusion (IR) injury, which is the insult due to hypothermic preservation plus graft reperfusion, and posttransplant lung function in Lewis rat lungs. Thirty rats were divided into 6 groups (n = 5). Groups 1 and 4 received 5 x 10(9) PFU of Ad5E1RSVhIL-10, groups 2 and 5 received 5 x 10(9) PFU of Ad5BGL2 ("empty" vector), and groups 3 and 6 received 3% sucrose (diluent). After 24 hr of in vivo transfection, lungs were stored at 4 degrees C (cold ischemic time, CIT) for 6 hr (groups 1-3) or 24 hr (groups 4-6) before transplantation. After 2 hr of reperfusion, lung function was assessed by oxygenation (FIO2, 1.0), airway pressure (AwP), and wet-to-dry (W/D) weight ratios. Rat tumor necrosis factor alpha (rTNF-alpha), interferon gamma (IFN-gamma), IL-10, and hIL-10 were measured in graft tissue and recipient plasma by ELISA and detected by immunohistochemistry (IHC). Partial pressure of oxygen (PaO2) levels in the hIL-10 group (6 hr of CIT) were higher than in empty vector and diluent groups (PaO2, 530 +/- 23 vs. 387 +/- 31 and 439 +/- 27 mmHg, respectively, p < 0.05). IL-10 rats after 24 hr of CIT showed higher PaO2 levels (260 +/- 29 mmHg) than empty vector (96 +/- 24 mmHg) or diluent (133 +/- 10 mmHg) lungs (p < 0.05). AwP and W/D ratios were reduced in hIL10 lungs (p < 0.05) compared with the other groups. rTNF-alpha and INF-gamma were reduced in tissue and plasma in groups 1 and 4 (p < 0.05). rIL-10 was reduced in the tissue of hIL-10 lungs (p < 0.05). IHC showed equal distribution of cytokines in tissue and abundant transgene expression in large and small airway epithelium in hIL-10 lungs.     

Acid cholesteryl ester hydrolase activity of mononuclear leukocyte in type 2 (non-insulin-dependent) diabetic patients

Acid cholesteryl ester hydrolase activity of mononuclear leukocytes was measured in 52 Type 2 (non-insulin-dependent) diabetic patients. Enzyme activity was significantly lower in the diabetic patients than in 14 age-matched control subjects (0.89 +/- 0.08 (mean +/- S.E.) vs. 2.20 +/- 0.17 nmol/mg protein/hr, p less than 0.01). In diabetic patients undergoing diet treatment only, the enzyme activity was significantly lower in poorly controlled patients than in well controlled patients (0.43 +/- 0.03 vs. 1.15 +/- 0.24 nmol/mg protein/hr, p less than 0.01). In the diabetic patients, there was a significant negative correlation between the enzyme activity and serum total cholesterol or low density lipoprotein cholesterol level (r = -0.361, p less than 0.01, n = 52 or r = -0.630, p less than 0.01, n = 28). These results suggest that a low level of acid cholesteryl ester hydrolase activity in mononuclear leukocyte might play an important role in the progression of atherosclerosis in Type 2 diabetes.     

Alterations in Hepatic Gluconeogenesis, Prostanoid, and Intracellular Calcium during Sepsis

OBJECTIVE: The metabolic alterations observed during sepsis may be associated with changes in local concentrations of intracellular calcium (Ca2+) and prostanoid synthesis in the liver. The authors studied hepatocyte intracellular Ca2+ and the release of glucose and prostanoid in an in-vivo murine liver perfusion model. METHODS: Sepsis was induced in anesthetized, fasted rats by cecal ligation and puncture (CLP, n = 42). Hepatic glucose release was studied in control (n = 10) and CLP (n = 10) groups using a non-recirculating liver perfusion model with and without lactate as gluconeogenic substrate. Hepatocyte intracellular Ca2+ (n = 11) was measured using the selective indicator Fura-2 under basal and epinephrine (10(-5) M) stimulated conditions. 6-Keto-prostaglandin F1alpha (6-Keto) and thromboxane B2 (TxB2) were determined from liver perfusate by radioimmunassay (n = 11). Data were analyzed using t-tests and repeated-measures ANOVA. RESULTS: Plasma glucose was significantly lower in CLP groups compared with controls (74.9+/-6.6 vs 115.7+/-4.6 mg/dL, p < 0.05). Plasma lactate was significantly higher in CLP vs controls (3.7+/-0.4 vs 1.4+/-0.1 mM, p < 0.05). Glucose release in isolated perfused livers was significantly lower in CLP vs controls (8.5 vs 16+/-1.2 microM/g/hr, p < 0.001). With the addition of lactate + pyruvate to the perfusate, glucose output in CLP livers was significantly lower following 5 (9.9+/-0.7 vs 17.7+/-1.1 microM/g/hr, p < 0.05) and 10 (11.9+/-1.2 vs 20.6+/-1.3 microM/g/hr, p < 0.001) minutes of perfusion. The basal level of intracellular calcium ([Ca2+]i) in CLP rats (460.1+/-91.6 nM) was significantly higher than in control rats (196.3+/-35.5 nM) (p < 0.05). A significant increase (p < 0.05) in [Ca2+]i occurred after the addition of epinephrine in hepatocytes in control (196.3+/-35.5 vs 331.8+/-41.4 nM) but not CLP (460.1+/-91.6 vs 489.4+/-105 nM) rats. 6-Keto was significantly lower in CLP compared with controls at 30 minutes (25.7+/-3.9 vs 33.4+/-5.5 pg/mL, p < 0.05), whereas TxB2 was not significantly altered (52.1+/-34.7 vs 87.5+/-43.2 pg/mL). CONCLUSION: These results demonstrate that CLP sepsis is associated with an increase in hepatocyte intracellular free Ca2+ concentration along with attenuation of hormone-mediated Ca2+ mobilization and hepatic gluconeogenesis.     

Nitric oxide, lipid peroxides, and uric acid levels in pre-eclampsia and eclampsia

The aim was to study the role of nitric oxide (NO), lipid peroxides (LPX), and uric acid in pre-eclampsia and eclampsia. Plasma levels of NO metabolites (nitrite+nitrate), malonyldialdehyde (MDA), and uric acid and erythrocyte MDA levels were compared between normal pregnant, pre-eclamptic, and eclamptic pregnant women in third trimester. Student's t-test was used for statistical evaluation. Plasma NO metabolites levels were higher in eclamptic group (35.7 +/- 16.5 micromol/liter, p < 0.05) but not in pre-eclamptic group (22.1 +/- 10.8 micromol/liter) than control group (18.8 +/- 6.9 micromol/liter). Plasma MDA and uric acid concentrations were higher in preeclamptic (4.4 +/- 1.7 nmol/ml, p < 0.05; 0.45 +/- 0.11 mmol/liter, p < 0.05, respectively) and eclamptic (5.8 +/- 1.9 nmol/ml, p < 0.05; 0.47 +/- 0.12 mmol/liter, p < 0.05) groups compared with control group (3.0 +/- 1.3 nmol/ml; 0.35 +/- 0.06 mmol/liter). Erythrocytes MDA concentrations were higher only in eclamptic group (174.4 +/- 62 nmol/gHb, p < 0.05) than control group (139.2 +/- 49.5 nmol/gHb). These results suggest that NO, LPX, and uric acid are important factors in the pathogenesis of pre-eclampsia and eclampsia, and that NO production and LPX are directly related to the severity of disease.     

Disposition of drugs in cystic fibrosis. III. Acetaminophen.

The disposition of acetaminophen after oral administration was investigated in adults with cystic fibrosis (n = 5) and in age-matched healthy control subjects (n = 5). The total plasma clearance of acetaminophen was found to be greater (p less than 0.025) in subjects with cystic fibrosis (0.362 +/- 0.081 L/hr/kg) than in control subjects (0.247 +/- 0.022 L/hr/kg). This difference in clearance was found to be primarily attributable to a greater metabolic clearance of acetaminophen to acetaminophen sulfate (0.080 +/- 0.023 L/hr/kg for subjects with cystic fibrosis and 0.045 +/- 0.008 L/hr/kg for control subjects; p less than 0.05) and to a greater metabolic clearance of acetaminophen to acetaminophen glucuronide (0.189 +/- 0.051 L/hr/kg for subjects with cystic fibrosis and 0.114 +/- 0.017 L/hr/kg for control subjects; p less than 0.05) in persons with cystic fibrosis. Of the mechanisms that may be responsible for these differences, the most likely is enhanced activity (in subjects with cystic fibrosis) of the transferases that mediate the metabolism of acetaminophen to acetaminophen sulfate and acetaminophen glucuronide, respectively.     

The maternal serum cortisol levels after onset of labor

We measured maternal cortisol levels after the onset of labor. Blood from 82 primiparas and 48 multiparas were collected 124 times and 60 times, respectively. When duration of labor was within 3 hr, there were no differences in cortisol levels between the primiparous (n = 11, 50.4 +/- 7.0 micrograms/100 ml, mean +/- S.E.) and multiparous (n = 14, 37.8 +/- 4.3 micrograms/100 ml). However, when duration of labor was from 3 to 6 hr, cortisol levels in the primiparas (n = 20, 59.7 +/- 5.1 micrograms/100 ml) were significantly (p less than 0.05) higher than those in the multiparas (n = 22, 46.8 +/- 2.9 micrograms/100 ml). In cases of duration of labor from 6 to 9, cortisol level of the primiparas (n = 24, 64.3 +/- 4.4 micrograms/100 ml) were also significantly (p less than 0.05) higher than those in multiparas (n = 12, 49.4 +/- 4.7 micrograms/100 ml). When duration of labor was more than 9 hr there was no significant difference in cortisol level between the primiparas and multiparas. Maternal cortisol level had a significant (p less than 0.01) negative correlation (n = 166, r = -0.243, Y = -0.09X + 30.47) with unconjugated estriol level. These data suggest that maternal cortisol levels after the onset of labor are slightly different between the primiparous and multiparous, and that maternal unconjugated estriol levels decrease owing to reduction of the feto-placental blood circulation accompanied with uterus contraction during labor.     

Elevated serum and spleen angiotensin converting enzyme and serum lysozyme in Gaucher's disease.

In adult chronic non-neuronopathic (Type 1) Gaucher's disease significant (p less than 0.001) elevations of angiotensin converting enzyme in serum (93.3 +/- 14.8 nmol/min/ml; number elevated, 8/11; normal control 32.2 +/- 1.30, n = 58) and spleen (5.62 +/- 0.35 nmol/min/mg protein, n = 2; control, 0.431 +/- 0.101, n = 4) and serum lysozyme (15.6 +/- 3.37 mug/ml; number elevated, 4/5) were observed. The KM for hippuryl-L-histidyl-L-leucine of Gaucher (1.31 mM) and normal (1.23 mM) serum angiotensin converting enzyme were similar. The increased angiotensin converting enzyme (ACE) in Gaucher's disease may be related to the genetic defect resulting in increased ACE synthesis in Gaucher cells, or perhaps generally, while high lysozyme may reflect an increased body mass of reticuloendothelial cells. These enzyme elevations may be of use in suggesting the possible presence of Gaucher's disease and perhaps in assessing the magnitude of pathologic involvement.     

Effects of mean airway pressure and tidal excursion on lung injury induced by mechanical ventilation in an isolated perfused rabbit lung model.

OBJECTIVE: To study the relative contributions of mean airway pressure (mPaw) and tidal excursion (V(T)) to ventilator-induced lung injury under constant perfusion conditions. DESIGN: Prospective, randomized study. SETTING: Experimental animal laboratory. SUBJECTS: Fifteen sets of isolated rabbit lungs. INTERVENTIONS: Rabbit lungs were perfused (constant flow, 500 mL/min; capillary pressure, 10 mm Hg) and randomized to be ventilated at identical peak transpulmonary pressure (pressure control ventilation [30 cm H2O and frequency of 20/min]) with three different ventilatory patterns that differed from each other by either mPaw or V(T): group A (low mPaw [13.4+/-0.2 cm H2O]/large V(T) [55+/-8 mL], n = 5); group B (high mPaw [21.2+/-0.2 cm H2O]/small V(T) [18+/-1 mL], n = 5); and group C (high mPaw [21.8+/-0.5 cm H2O]/large V(T) [53+/-5 mL], n = 5). MEASUREMENTS AND MAIN RESULTS: Continuous weight gain (edema formation), change in ultrafiltration coefficient (deltaKf, vascular permeability index), and histology (lung hemorrhage) were examined. In group A, deltaKf (0.08+/-0.08 g/min/cm H2O/100 g) was less than in group B (0.28+/-0.19 g/min/cm H2O/100 g) or group C (0.41+/-0.29 g/min/cm H2O/100 g) (p = .05). Group A experienced significantly less hemorrhage (histologic score, 5.4+/-2.2) than groups B (10.3+/-2.1) and C (11.1+/-3.0) (p < .05). A similar trend was observed for weight gain. In contrast to tidal excursion, mPaw was found to be a significant factor for lung hemorrhage and increased Kf (two-way analysis of variance; p < .05). Weight gain (r2 = .54, p = .04) and lung hemorrhage (r2 = .65, p = .01) correlated with the mean pulmonary artery pressure changes that resulted from the implementation of the ventilatory strategies. The difference between the changes in mPaw and mean pulmonary artery pressure linearly predicted deltaKf (p = .005 and .05, respectively, r2 = 0.73). CONCLUSIONS: Under these experimental conditions, mPaw contributes more than tidal excursion to lung hemorrhage and permeability alterations induced by mechanical ventilation.     

Elastic recoil pressure arising from surface tension in hamster lungs treated with intratracheal bleomycin

Lung elastic recoil pressure arising from surface tension (Ps) was evaluated in normal and bleomycin-treated lungs. Twenty two male golden hamsters were separated into a control group (group A, n = 10) and a bleomycin group (group B, n = 12). Group B was given a single intratracheal instillation of bleomycin and group A was given normal saline as a control. Thirty days after instillation, three cycles of static air -and saline-filled pressure-volume curves (P-V curve) were measured. Ps was graphically derived from air- and saline-filled P-V curves. The Ps of groups A and B were compared at the same lung volumes. Mean body weight and nose-to-tail length of the two groups did not differ significantly. Total lung capacity, defined as lung air volume at a transpulmonary pressure of 25 cmH2O, was significantly smaller in group B (mean +/- S.E. was 4.08 +/- 0.20 ml) than in group A (mean +/- S.E. was 5.23 +/- 0.12 ml) (p less than 0.01). The Ps of group B was significantly larger than that of group A at all lung volumes studied (p less than 0.01-0.05). These results indicate that the lung elastic recoil pressure component due to the surface tension was increased by intratracheal instillation of bleomycin in hamsters.     

Inhibition of ischemia-induced phospholipase activation by quinacrine protects jeopardized myocardium in rats with coronary artery occlusion

Phospholipase activation has been proposed as one relevant biochemical step toward irreversible myocardial injury during ischemia. Accordingly, after coronary artery occlusion, the time course of myocardial phospholipid degradation was studied in 83 control rats and 84 rats treated with quinacrine (75 mg/kg s.c. every 8 hr), a phospholipase inhibitor. Animals were sacrificed at different times ranging from 2 to 48 hr postocclusion. In controls a rapid fall in left ventricular phospholipid concentration (from 1.33 +/- 0.12 to 0.67 +/- 0.05 micrograms of P/mg of protein) and creatinkinase (CK) activity (from 9.84 +/- 0.49 to 6.93 +/- 0.60 I.U./mg of protein) was observed within 4 hr postocclusion. In quinacrine-treated animals phospholipids and CK also fell initially; however, 24 and 48 hr after occlusion they were higher than in controls (phospholipids: 0.99 +/- 0.05 vs. 0.62 +/- 0.04 micrograms of P/mg of protein, P less than .001; CK: 7.76 +/- 0.54 vs. 4.99 +/- 0.37 I.U./mg of protein, P less than .001, at 48 hr). Additional rats surviving coronary occlusion were divided randomly into a control (n = 14) and three treated groups receiving quinacrine every 8 hr at the dose of 5 (n = 13), 20 (n = 13) or 75 mg/kg (n = 15); 13 rats were sham-operated. Forty-eight hours postocclusion myocardial phospholipids were measured and infarct size calculated by CK depletion. Infarct size was significantly smaller in high dose quinacrine-treated than in control rats (16.6 +/- 5.7 vs. 42.1 +/- 4.4% of left ventricle, P less than .001). In treated animals, myocardial phospholipid concentration was also significantly higher.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma adrenaline and noradrenaline during orthostasis in man: the importance of arterial sampling

Plasma adrenaline and noradrenaline were measured in arterial blood and in forearm venous blood during supine rest and after 30 min standing in normotensive, healthy 50-year-old men (n = 16). After 30 min standing, venous noradrenaline had increased from 1.61 +/- 0.11 to 4.22 +/- 0.30 nmol/l and arterial from 1.43 +/- 0.06 to 2.93 +/- 0.15 nmol/l. Orthostasis induced a seven-fold increment in the forearm arterial-venous difference of noradrenaline from -0.18 +/- 0.08 to -1.29 +/- 0.25 nmol/l (p less than 0.001). Orthostasis more than doubled the forearm arterial-venous difference of adrenaline from 0.15 +/- 0.03 to 0.31 +/- 0.05 nmol/l (p less than 0.001) since arterial adrenaline increased from 0.31 +/- 0.03 to 0.53 +/- 0.05 nmol/l and venous from 0.16 +/- 0.02 to 0.22 +/- 0.02 nmol/l. Arterial adrenaline correlated significantly with venous in the supine (r = 0.64, p less than 0.01) but not in the standing position (r = 0.34, NS). The results indicate that arterial concentrations of adrenaline are a much better indicator of sympatho-adrenal activity during orthostasis than peripheral venous concentrations. For noradrenaline, measurements of arterial concentrations during the orthostatic manoeuvre seem to provide information about the total noradrenergic sympathetic reactivity, while the corresponding measurements in peripheral venous blood represent the forearm locally.     

Pharmacokinetics of amiodarone in the isolated rat lung

In these studies we examined the kinetics of amiodarone (Am) uptake and efflux in/from the lung, and the influence of other amphiphilics on these processes. We used single-pass perfused isolated lungs from rats. Medium containing Am (30 microM + 1 microCi of [14C]Am) was perfused through the lung for 20 min (uptake), followed by 20 min of perfusion with drug-free medium (efflux). Lack of metabolism enabled us to follow Am by measuring the amount of radioactivity in perfusate and lung. Other concentrations of Am (3, 60 and 120 microM; n = 2-4 each) were also examined. Inhibited uptake and accelerated efflux of Am were attempted with the pneumophilic amphiphilics chlorimipramine, chlorphentermine, chlorpromazine, verapamil and with the main metabolite of Am: desethylamiodarone (60 and/or 240 microM; n = 3-4 lungs each). Lung extracted Am extensively during uptake. The amount of Am accumulated at 20 min (inflowing concentration: 30 microM) averaged 1307 +/- 109 (S.E.) nmol/g, corresponding to a tissue to medium ratio of 43.3 +/- 1.6. Spontaneous efflux of Am was incomplete. At 40 min, 862 +/- 105 nmol of Am remained bound per g of lung, suggesting sequestration of Am in a slowly effluxable pool in which calculations show that more than 50% of the drug will ultimately persist. Uptake and efflux rates obey biexponential kinetics, indicating storage into two pools. Uptake rate and the amount of Am accumulated in lung at 20 min increased in proportion to inflowing concentration up to 60 microM. At 120 microM the increase was less. Neither amphiphilic was capable of inhibiting Am uptake, whereas only chlorphentermine significantly accelerated Am efflux.(ABSTRACT TRUNCATED AT 250 WORDS)     

维生素C对脂多糖急性肺损伤大鼠的保护作用

目的 观察维生素C对大鼠脂多糖性急性肺损伤的保护作用及其机制。方法 健康成年Sprague—Dawley（SD）大鼠24只,雌雄不拘,体重180—200g,随机分成三组：0．9％氯化钠注射液组（NS组）、脂多糖组（LPS组）和维生素C治疗组（VitC组）,每组8只大鼠。三组大鼠分别在脂多糖或0．9％氯化钠注射液注入后4h放血处死,测定肺组织丙二醛含量、髓过氧化物酶活性（myeloperoxiase,MPO）及肺湿干重比值（W／D）,留少许肺标本固定切片观察病理变化。结果 与NS组比较,LPS组肺组织MDA含量显著增加、MPO活性显著升高,W／D显著增加（t分别=0．01、6．54、6．19,P均〈0．05）;与LPS组比较,VitC组肺组织MDA含量减少、MPO活性明显降低、W／D显著下降（t分别=0．02、7．73、4．61,P均〈0．05）。LPS组肺组织病理切片可见明显急性肺损伤病理改变,维生素C治疗组显示损伤较轻。讨论 大剂量维生素C对脂多糖所致的大鼠急性肺损伤具有保护作用。     

百草枯中毒致大鼠肺组织损伤时氨溴索对肺组织Bcl-2/Bax的表达及细胞凋亡的影响

目的 探讨在百草枯(PQ)中毒所致大鼠急性肺损伤时氨溴索(AM)对肺组织Bcl-2/Bax的表达及细胞凋亡的影响.方法 44只大鼠随机分为4组:正常对照组(C组)6只、AM对照组(AM组)6只、急性肺损伤组(PQ组)16只和急性肺损伤+AM治疗组(PQ+AM组)16只.取肺组织苏木精-伊红(HE)染色来评价肺组织损伤情况;检测血清中肿瘤坏死因子α(TNF-α)水平;蛋白质印迹方法检测肺组织p38丝裂酶原激活蛋白激酶(MAPK)表达;肺组织Bcl-2、Bax免疫组化分析;TUNEL检测肺组织细胞凋亡.结果 C组和AM组大鼠的肺组织结构基本完整,PQ组肺组织损伤程度加重,PQ+AM组肺组织损伤程度较PQ组减轻.PQ组血清TNF-α水平、p38 MAPK和Bax蛋白表达、肺组织细胞凋亡均较C组和AM组显著增加(P＜0.05),PQ+AM组较PQ组均有降低(P＜0.05),而抗凋亡基因Bcl-2在AM干预后较PQ组升高(P＜0.05).结论 百草枯中毒导致了大鼠急性肺损伤,经氨溴索治疗后,通过调节p38 MAPK、Bcl-2和Bax蛋白的表达从而使肺组织细胞凋亡减少,从而有效地减轻了百草枯中毒所致的大鼠急性肺损伤.     

Biochemical evidence for an increased and progressive deposition of collagen in lungs of patients with pulmonary fibrosis

To assess the role of changes in lung collagen in pulmonary fibrosis, the content of this protein was measured in biopsy and autopsy lung from patients with cryptogenic fibrosing alveolitis (CFA), a fibrotic lung disorder of unknown cause. The collagen concentration was measured in lung samples from 21 patients with CFA (14 autopsy and seven open-lung biopsy) and 17 normal subjects; total lung collagen was determined in the right lung of 10 patients who died from CFA and the results were compared with those from 10 normal lungs. There was a wide variation in the collagen concentrations but the mean value (+/- SEM) for patients with CFA (217 +/- 13 mg/g dry weight) was significantly higher (P less than 0.02) than that of the controls (155 +/- 15 mg/g dry weight). The mean collagen concentration of the autopsy samples (243 +/- 20 mg/g dry weight) was significantly higher (P less than 0.05) than that of the biopsy samples (165 +/- 24 mg/g dry weight). The mean total collagen was markedly raised (P less than 0.001) in right lungs of patients with CFA (32.5 +/- 4.3 g) compared with normal lungs (14.0 +/- 1.1 g). When corrected for the predicted lung volume this difference in total lung collagen remained statistically significant (P less than 0.01, mean for patients 4.7 +/- 0.7 mg/ml, controls 2.3 +/- 0.2 mg/ml). These results demonstrate an increased deposition of lung collagen in this form of pulmonary fibrosis. They also suggest that there is a greater collagen concentration in lungs of patients with later disease, indicating a progressive deposition of collagen during the course of the disease.     

Effect of hyperbaric oxygen on endotoxin-induced lung injury in rats

Oxygen therapy remains the main component of the ventilation strategy for treatment of patients with acute lung injury. Hyperbaric oxygen therapy (HBO(2)) is the intermittent administration of 100% oxygen at pressure greater than sea level and has been applied widely to alleviate a variety of hypoxia-related tissue injuries. The purpose of this study was to evaluate the effect of hyperbaric oxygen on acute lung injury induced by intratracheal spraying of lipopolysaccharide (LPS) in rats. Male Sprague-Dawley rats underwent implantation of a carotid artery catheter under general anesthesia. Aerosolized LPS was delivered twice into the lungs via intratracheal puncture. Animals were either breathing room air (n = 27) or subjected to hyperbaric oxygen (HBO(2)) exposure (n = 27) 1 h after LPS spraying. Acute lung injury was evaluated 5 h and 24 h later. Compared with the control group, intratracheal spraying of LPS caused profound hypoxemia, greater wet/dry weight ratio (W/D) of the lung (5.67 +/- 0.22 vs. 4.98 +/- 0.19), and higher protein concentration (1706 +/- 168 vs. 200 +/- 90 mg/L) and LDH activity (129 +/- 30 vs. 46 +/- 15, mAbs/min) in bronchoalveolar lavage (BAL) fluid. Intratracheal spraying of LPS also caused significant WBC sequestration in the lung tissue. HBO2 treatment significantly reverted hypoxemia, reduced lung injury measures evaluated at 5 and 24 h, and enhanced 24-h animal survival rate (chi = 5.08, P = 0.024). The malondialdehyde (MDA) concentrations in lung tissue and serum were both increased after LPS spraying. Neither single HBO(2) therapy nor five sequential daily treatments enhanced MDA production in lung tissue or serum. Our results suggested that hyperbaric oxygen might reduce acute lung injury caused by intratracheal spraying of LPS in rats. This treatment modality is not associated with enhancement of oxidative stress to the lung.     

Regional blood volume changes during acute pericardial tamponade

Using radionuclide blood pool imaging, we evaluated sequential changes in heart, lung, liver, and spleen intravascular volumes were evaluated before and during acute pericardial tamponade in 9 anesthetized dogs. Tamponade resulted in an abrupt (less than 1 min) decline in mean right heart (-30 +/- 5%, p less than 0.001 vs control) and left heart volumes (-27 +/- 4%, p less than 0.001 vs control), with a concomitant reduction in pulmonary volume (-17 +/- 3%, p less than 0.01 vs control). Within this short time frame, both hepatic (+19 +/- 3%) and splenic (+16 +/- 4%, both p less than 0.01 vs control) volumes rose. Five min after the production of tamponade, right and left heart volumes were still significantly reduced (-28 +/- 4, p less than 0.005 vs control and -23 +/- 2%, p less than 0.005 vs control), though pulmonary (+2 +/- 5%, p = NS vs control), hepatic (+7 +/- 3%, p less than 0.05 vs control) and splenic (+9 +/- 3%, p less than 0.05 vs control) volumes had returned toward baseline values. These volume changes were similar at 20 min after tamponade. Thus, tamponade resulted in a sudden shunting of blood from the central to the peripheral circulation, initially from both the lungs and heart. After 5 min pulmonary volumes returned to baseline values, while splenic and hepatic volumes remained slightly, though significantly elevated.     

Time course of alterations in lung lymph and bronchial blood flows after inhalation injury

The effects of inhalation injury on the pulmonary microvascular fluid flux and bronchial blood flow were examined in a long-term study of sheep (N = 13). They were insufflated with either 48 breaths of cotton smoke (n = 8) or air (n = 5) while they were deeply anesthetized with halothane. After injury, anesthesia was discontinued and the animals were mechanically ventilated throughout the experimental period (24 hours). Bronchial blood flow increased significantly at all time points recorded and reached its peak 20 minutes after the inhalation trauma (11 +/- 1 ml/hr to 106 +/- 18 ml/hr; p less than 0.05). Thereafter, bronchial blood flow decreased to a value that was six to eight times above the baseline measurement for the remainder of the study period. With these changes in blood flow, there was a concomitant increase in lung lymph flow. This variable gradually increased and was 633% of the baseline value (6 +/- 1 ml/hr to 44 +/- 8 ml/hr) 24 hours after the challenge with smoke. The control animals showed little or no change in cardiopulmonary function during the experimental period. There is no correlation between the increase in bronchial blood flow and lung lymph flow patterns after cotton smoke inhalation injury.     

Dose optimization of a doxorubicin prodrug (HMR 1826) in isolated perfused human lungs: low tumor pH promotes prodrug activation by beta-glucuronidase

HMR 1826 (N-[4-beta-Glucuronyl-3-nitrobenzyl-oxycarbonyl]doxorubicin) is a nontoxic glucuronide prodrug from which active doxorubicin is released by beta-glucuronidase. Preclinical studies aimed at dose optimization of HMR 1826, based on intratumoral pharmacokinetics, are important to design clinical studies. Using an isolated perfused human lung model, the uptake of doxorubicin into normal tissue and tumors after perfusion with 133 microg/ml (n = 6), 400 microg/ml (n = 10), and 1200 microg/ml (n = 6) HMR 1826 was compared. Extracellular tissue pH was measured, and enzyme kinetic studies were performed in vitro to investigate the effect of pH on the formation of doxorubicin. Extracellular pH was lower in tumors than in healthy tissue (6.46 +/- 0.35, n = 8 versus 7.30 +/- 0.33, n = 10; p < 0.001). In vitro, beta-glucuronidase activity was 10 times higher at pH 6.0 than at neutral pH. After perfusion with HMR 1826, there was a linear relationship between HMR 1826 concentrations in perfusate and normal lung tissue. After perfusion with 133, 400, and 1200 microg/ml HMR 1826, the final doxorubicin concentrations in normal and tumor tissue were 2.7 +/- 0.9, 11.1 +/- 5.4, and 21.8 +/- 8.4 microg/g (p < 0.05 for all comparisons), and 0.7 +/- 0.3, 8.6 +/- 2.0 microg/g (p < 0.01 versus 133 microg/g), and 8.7 +/- 4.9 microg/g, respectively. This agrees with the enzyme kinetic observations of saturation of beta-glucuronidase at 400 microg/ml HMR 1826 in the acidic environment of the tumor. Therefore, the escalation of the HMR 1826 dose most likely results in higher circulating concentrations than 400 microg/ml but does not increase the uptake of doxorubicin into tumors and, subsequently, antitumor efficacy. The isolated perfused human lung is an excellent model for preclinical investigations aimed at optimization of tissue pharmacokinetics of tumor-selective prodrugs.     

Vascular distribution of plasma catecholamines--pulmonary extraction, arterio-venous differences and effect of age

In 19 normotensive patients undergoing cardiac catheterization, plasma samples were simultaneously collected from five different sites for measuring adrenaline and noradrenaline concentrations. Mean levels (+/- SEM) in pulmonary artery and aorta were 1.70 +/- 0.13 and 1.76 +/- 0.12 nmol/l for noradrenaline and 0.35 +/- 0.05 and 0.36 +/- 0.05 nmol/l for adrenaline, respectively. Thus, no pulmonary uptake of either catecholamine was demonstrated; this was independent of ventilatory lung function. Significant peripheral extraction was only found for adrenaline, and not for noradrenaline, so we found no evidence for the necessity of arterial blood sampling for noradrenaline determinations in this static study. Finally, a significant positive correlation of venous (r = 0.56; p less than 0.01), but not arterial noradrenaline concentration with age was found, as was a negative correlation of both arterial (r = -0.55; p less than 0.01) and venous (r = -0.62; p less than 0.005) adrenaline concentrations with age. The release of adrenaline by the adrenal glands proved to be significantly decreasing with increasing age (r = -0.53; p less than 0.02).