Expression of lumican in human lungs

The collagen-elastin-proteoglycan (PG) matrix is the key constituent of lung parenchyma and plays a major role in the mechanical behavior of lung tissues. However, the exact composition of the PG matrix in lungs has not yet been fully determined. In the present study we report the expression of leucine-rich repeat PGs in adult human lungs. PG extraction was performed on peripheral lung tissue from patients undergoing therapeutic lung resections. The samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting using antipeptide antisera specific to human lumican, decorin, biglycan, and fibromodulin. Control experiments to verify antiserum reactivity were performed with an extract of adult human articular cartilage, which is known to contain all four PGs. In all lung extracts analyzed, a single component of molecular weight 65 to 90 kD was detected for lumican. Decorin, biglycan, and fibromodulin were either not detected or were barely detectable in the lung extracts, but were readily visualized in the cartilage samples. Immunohistochemistry showed that lumican was diffusely present in peripheral lung tissue, mainly in vessel walls. These results suggest that lumican is a major component of the PG matrix in adult human lungs.

Changes of tissue factor activity on inflammatory stimulus and aging in rat

Tissue factor (TF), a principal initiator of the vertebrate coagulation cascade, is expressed in organ tissues, cells and blood. TF is known to be induced in endothelial cells, monocytes and macrophages by inflammatory stimuli and in many pathologic conditions. By using the modified method for in vivo TF activity assay, we found that turpentine oil injection as an inflammatory stimulus also induced the TF activity in lung and brain tissues of rats. And the age-related increase in TF activity was observed in healthy rat brain tissue.

Endogenous nitric oxide in patients with stable COPD: correlates with severity of disease

BACKGROUND

Increased levels of exhaled nitric oxide (eNO) have been reported in asthmatic subjects but little information is available on eNO in patients with advanced chronic obstructive pulmonary disease (COPD). A study was undertaken to evaluate the levels of eNO in patients with stable COPD of different degrees of severity.

METHODS

Peak and plateau values of eNO (PNO and PLNO, respectively) were evaluated in 53 patients with COPD and analysed according to the level of forced expiratory volume in one second (FEV1) and the presence of cor pulmonale (CP) (group 1, FEV1 < 35% predicted with CP, n = 15; group 2, FEV1 < 35% predicted without CP, n = 15; group 3, FEV1 > 35% predicted, n = 23). Seventeen normal subjects served as controls.

RESULTS

All the patients with COPD had reduced levels of PLNO compared with the controls (mean (SD) 6.3 (3.0) and 9.4 (2.8) ppb, respectively). In groups 1 and 2 PLNO levels were significantly lower than in subjects in group 3 (5.5 (2.9), 5.7 (3.5), and 7.1 (2.7) ppb, respectively; p < 0.01 ANOVA). In all subjects % predicted FEV1 correlated slightly with PLNO but not with PNO.

CONCLUSION

Patients with severe stable COPD have reduced levels of eNO compared with normal subjects. eNO levels are slightly related to the severity of airflow obstruction.

Contribution of reactive oxygen and nitrogen species to particulate-induced lung injury

Recently, a second pathway for the generation of potential oxidants with the reactivity of the hydroxyl radical without the need for metal catalysis has been described. In response to various inflammatory stimuli, lung endothelial, alveolar, and airway epithelial cells, as well as activated alveolar macrophages, produce both nitric oxide (.NO) and superoxide anion radicals (O2.-). .NO regulates pulmonary vascular and airway tone and plays an important role in lung host defense against various bacteria. However, .NO may be cytotoxic by inhibiting critical enzymes such as mitochondrial aconitase and ribonucleotide reductase, by S-nitrosolation of thiol groups, or by binding to their iron-sulfur centers. In addition, .NO reacts with O2.- at a near diffusion-limited rate to form the strong oxidant peroxynitrite (ONOO-), which can nitrate and oxidize key amino acids in various lung proteins such as surfactant protein A, and inhibit their functions. The presence of ONOO- in the lungs of patients with acute respiratory distress syndrome has been demonstrated by measuring levels of nitrotyrosine, the stable product of tyrosine nitration. Various studies have shown that inhalation or intratracheal instillation of various respirable mineral dusts or asbestos fibers increased levels of inducible nitric oxide synthase mRNA. In this presentation, we review the evidence for the upregulation of .NO in the lungs of animals exposed to mineral particulates and assess the contribution of reactive nitrogen species in the pathogenesis of the resultant lung injury.

Prion distribution in hamster lung and brain following intraperitoneal inoculation

Prion titres were measured in the lungs and brains of Syrian hamsters after intraperitoneal inoculation with sucrose gradient-purified 263K prions (approximately 10(8) LD50). Prions were detected in the lung of one hamster on day 7, but were not detected in the lungs of any other hamster until day 71. Prions were detected in the lungs of all hamsters sampled thereafter but titres remained low through day 127. Prions were first detected in the brain on day 35 and brain titres increased exponentially until day 127 with a doubling time of about 4.5 days. On day 133, titres averaged 10(8.0) LD50/g in brain and 10(5.0) LD50/g in lung. Two out of the five remaining hamsters were clinically normal but prion titres were not significantly different from those in the clinically affected hamsters. Thus, significant prion titres may be found outside the CNS in clinically normal hamsters.

Nitric oxide deficiency in fenfluramine- and dexfenfluramine-induced pulmonary hypertension

Dexfenfluramine and fenfluramine greatly increase the risk of developing pulmonary hypertension (PHT). The mechanism of anorexigen-associated PHT (AA-PHT) and the reason PHT occurs in a minority of people exposed are unknown. Anorexigens are weak pulmonary vasoconstrictors, but they become potent when synthesis of the endogenous vasodilator nitric oxide (NO) is suppressed. We hypothesized NO deficiency predisposes affected individuals to develop AA-PHT. A prospective, case-control, study was performed on consecutive patients with AA-PHT (n = 9). Two sex-matched control groups were selected: patients with primary PHT (P-PHT, n = 8) and normal volunteers (n = 12). Lung NO production (VNO) and systemic plasma oxidation products of NO (NOx) were measured at rest and during exercise. AA-PHT developed 17 +/- 6 mo after a short course of anorexigen (6 +/- 2 mo) and was irreversible. VNO was lower in AA-PHT than in P-PHT and correlated inversely with PVR (p < 0.05). The apparent VNO deficiency may have resulted from increased oxidative inactivation of NO in patients with AA-PHT, as their NOx levels were elevated (p < 0.05) in inverse proportion to VNO (r2 = 0. 55; p < 0.02). In susceptible persons, anorexigens can cause an irreversible syndrome of PHT, hypoxemia, and systemic vascular complications after brief exposures. These patients have a relative NO deficiency years after discontinuing the anorexigen, perhaps explaining their original susceptibility.

Enhancement of nitric oxide production by pulmonary cells following silica exposure

In vivo exposure of rat lungs to crystalline silica either by intratracheal instillation or by inhalation results in an increase in mRNA levels for inducible nitric oxide synthase (iNOS) in bronchoalveolar lavage cells (BALC), elevated nitric oxide (.NO) production by BALC, and an increase in .NO-dependent chemiluminescence (CL) from alveolar macrophages (AM). Induction of iNOS message occurs in both AM and polymorphonuclear leukocytes (PMN) harvested from silica-exposed lungs but is not significantly elevated in lavaged lung tissue. In vitro exposure of AM to silica does not stimulate .NO production or enhance iNOS message. However, treatment of naive AM with conditioned media from BALC harvested from silica-exposed rats does increase iNOS message and .NO production by these AM. The potency of this conditioned medium is dependent on interaction between AM and PMN. In the rat model, a relationship exists between the ability of various dusts to cause PMN recruitment or protein leakage into the alveolar space and the induction of iNOS message in BALC, i.e., silica > coal mine dust > carbonyl iron > titanium dioxide. Similarly, a comparison of BALC from a healthy volunteer, a silica-exposed coal miner with a normal chest radiograph, and a silica-exposed coal miner with an abnormal chest radiograph shows a correlation between pathology and both the level of iNOS message in BALC and the magnitude of .NO-dependent CL from AM. These data suggest that .NO may play a role in silicosis and that human pulmonary phagocytes exhibit enhanced .NO production in response to an inflammatory insult.

Alpha and beta glucocorticoid receptor mRNA expression in skeletal muscle

The aim of the present study was to investigate the occurrence and autoregulation of both glucocorticoid receptor mRNAs in rat gastrocnemius muscle. The expression of both receptor forms was studied 1, 4 or 12 hours after intra-tracheal instillation of a high dose (100 micrograms) of budesonide; muscular expression was compared with glucocorticoid receptor expression in lung tissue. After Northern blot analysis, hybridization was performed with glucocorticoid receptor, glyceraldehyde-3-phosphate dehydrogenase and glutamine synthetase probes. In the gastrocnemius muscle, both the alpha and beta glucocorticoid receptor mRNA forms were detected and found to be downregulated four hours after the budesonide instillation. alpha/beta glucocorticoid receptor ratios were lower in the gastrocnemius (1.1 +/- 0.2) than in the lungs (2.6 +/- 0.6). In the lungs, at all time points, the average alpha glucocorticoid receptor mRNA levels did not differ from controls, although glutamine synthetase mRNA levels were upregulated. The beta glucocorticoid receptor mRNA was slightly reduced at 1 and 4 hours. In conclusion, after intra-tracheal instillation of budesonide, both alpha and beta glucocorticoid receptor forms were downregulated in muscle tissue. The difference in alpha/beta glucocorticoid receptor mRNA ratios and concentrations between lung and gastrocnemius muscle supports the hypothesis of differential gene regulation by glucocorticoids in different cell types.

Gut-derived mesenteric lymph but not portal blood increases endothelial cell permeability and promotes lung injury after hemorrhagic shock

OBJECTIVE

To determine whether gut-derived factors leading to organ injury and increased endothelial cell permeability would be present in the mesenteric lymph at higher levels than in the portal blood of rats subjected to hemorrhagic shock. This hypothesis was tested by examining the effect of portal blood plasma and mesenteric lymph on endothelial cell monolayers and the interruption of mesenteric lymph flow on shock-induced lung injury.

SUMMARY BACKGROUND DATA

The absence of detectable bacteremia or endotoxemia in the portal blood of trauma victims casts doubt on the role of the gut in the generation of multiple organ failure. Nevertheless, previous experimental work has clearly documented the connection between shock and gut injury as well as the concept of gut-induced sepsis and distant organ failure. One explanation for this apparent paradox would be that gut-derived inflammatory factors are reaching the lung and systemic circulation via the gut lymphatics rather than the portal circulation.

METHODS

Human umbilical vein endothelial cell monolayers, grown in two-compartment systems, were exposed to media, sham-shock, or postshock portal blood plasma or lymph, and permeability to rhodamine (10K) was measured. Sprague-Dawley rats were subjected to 90 minutes of sham or actual shock and shock plus lymphatic division (before and after shock). Lung permeability, pulmonary myeloperoxidase levels, alveolar apoptosis, and bronchoalveolar fluid protein content were used to quantitate lung injury.

RESULTS

Postshock lymph increased endothelial cell monolayer permeability but not postshock plasma, sham-shock lymph/plasma, or medium. Lymphatic division before hemorrhagic shock prevented shock-induced increases in lung permeability to Evans blue dye and alveolar apoptosis and reduced pulmonary MPO levels. In contrast, division of the mesenteric lymphatics at the end of the shock period but before reperfusion ameliorated but failed to prevent increased lung permeability, alveolar apoptosis, and MPO accumulation.

CONCLUSIONS

Gut barrier failure after hemorrhagic shock may be involved in the pathogenesis of shock-induced distant organ injury via gut-derived factors carried in the mesenteric lymph rather than the portal circulation.

Prognostic significance of HER-2/neu overexpression in stage I adenocarcinoma of lung

BACKGROUND

Even with early diagnosis and adequate resection, the 5-year survival rate for stage I lung cancer patients is around 60% to 70%. Overexpression of HER-2/neu protein is associated with poor prognosis in lung cancers. In this study, we evaluated the expression of HER-2/neu in cancer cells of lung and assessed their clinicopathologic and prognostic significance.

METHODS

From 1986 to 1995, clinical data on 42 consecutive patients who underwent complete surgical resection for stage I lung adenocarcinoma were collected. Expression of HER-2/neu in paraffin-embedded tumor samples was determined by immunohistochemistry and scored with a semiquantitative method.

RESULTS

Twenty-one of 42 patients were positive for HER-2/neu overexpression in tumor. Compared with patients with low HER-2/neu expression, patients with HER-2/neu overexpression had a significantly higher incidence of early tumor recurrence (p = 0.014). Survival was also significantly better in patients without HER-2/neu overexpression than in those with HER-2/neu overexpression (p = 0.0047). By univariate analysis, HER-2/neu overexpression and poor cell differentiation are two important factors correlated with poor prognosis.

CONCLUSIONS

Expression of HER-2/neu oncoprotein in stage I lung adenocarcinoma can predict the tumor's aggressiveness. Early tumor recurrence was frequently detected in patients with HER-2/neu overexpression. We recommend an individualized therapeutic strategy based on the level of HER-2/neu oncoprotein in the tumor cells.

Modulation of mitochondrial gene expression in pulmonary epithelial cells exposed to oxidants

Oxidants are important in the regulation of signal transduction and gene expression. Multiple classes of genes are transcriptionally activated by oxidants and are implicated in different phenotypic responses. In the present study, we performed differential mRNA display to elucidate genes that are induced or repressed after exposure of rat lung epithelial (RLE) cells to H2O2 or crocidolite asbestos, a pathogenic mineral that generates oxidants. After 8 or 24 hr of exposure, RNA was extracted, reverse transcribed, and amplified by polymerase chain reaction with degenerate primers to visualize alterations in gene expression. The seven clones obtained were sequenced and encoded the mitochondrial genes, NADH dehydrogenase subunits ND5 and ND6, and 16S ribosomal RNA. Evaluation of their expression by Northern blot analysis revealed increased expression of 16S rRNA after 1 or 2 hr of exposure to H2O2. At later time periods (4 and 24 hr), mRNA levels of 16S rRNA and NADH dehydrogenase were decreased in H2O2-treated RLE cells when compared to sham controls. Crocidolite asbestos caused increases in 16S rRNA levels after 8 hr of exposure, whereas after 24 hr of exposure to asbestos, 16S rRNA levels were decreased in comparison to sham controls. In addition to these oxidants, the nitric oxide generator spermine NONOate caused similar decreases in NADH dehydrogenase mRNA levels after 4 hr of exposure. The present data and previous studies demonstrated that all oxidants examined resulted in apoptosis in RLE cells during the time frame where alterations of mitochondrial gene expression were observed. As the mitochondrion is a major organelle that controls apoptosis, alterations in expression of mitochondrial genes may be involved in the regulation of apoptosis.

Roles of histamine receptor in a guinea pig asthma model

Histamine plays an important role in bronchoconstriction mediated by histamine receptors which provoke bronchial asthma attack. In this study, we measured H1 and H2 receptors in the guinea pig lung membrane fraction and obtained the following results. The maximum binding (Bmax) of H1 receptors in the guinea pig lung membrane fraction was significantly higher in the OA-sensitized group than that in the non-sensitized group, but affinity (Kd) did not differ between the groups. Otherwise, the maximum binding (Bmax) of H2 receptors in the guinea pig lung membrane fraction was significantly lower in the OA-sensitized group than that in the non-sensitized group. But affinity (Kd) did not differ between the groups. These findings suggest a close association of Histamine receptors both H1 and H2 in the pathology of asthma.

The evaluation of lung function with PET

In many ways, the lung is an ideal organ for study with positron emission tomography (PET). First, structure-function relations are homogeneous over larger areas than in other organs (reducing problems associated with otherwise relatively poor spatial resolution and partial-volume averaging). Second, many physiologic and metabolic processes can be studied, including pulmonary blood flow, ventilation, vascular permeability, endothelial receptor and enzyme function, among others. A variety of radiotracers have been used to evaluate pulmonary blood flow with PET, including 68Ga- or 11C-albumin microspheres administered intravenously, H2 15O administered by i.v. infusion, and 13N-N2 administered by inhalation. Pulmonary ventilation has been evaluated with both 13N-N2 and 19Ne gas, also administered by inhalation. In general, the relative advantage of one approach over another depends on site-specific cyclotron capacity and experience, and on the nature and timing of concomitant studies with other positron-emitting radiopharmaceuticals. The various blood flow methods have been used primarily in studies of pulmonary gas exchange, in both experimental animals and in humans. Acute lung injury is usually defined by both an increase in extravascular water (pulmonary edema) and an increase in the permeability of the pulmonary endothelium to protein. Both processes can easily be evaluated with PET. Extravascular water is measured by a combination of scans with i.v. H2 15O and C15O. The latter is administered by inhalation to label the blood pool (to calculate intravascular water concentrations). Pulmonary vascular permeability has been evaluated with dynamic sequential imaging after either 68Ga-transferrin or 11C-methylalbumin infusions. The rate of uptake of either tracer into the pulmonary extravascular space is an index of "leakiness" of the pulmonary endothelium, and is quantified as the pulmonary transcapillary escape rate, or PTCER. PTCER appears to be a highly sensitive index of acute lung injury. Two receptor/ enzyme systems that have been evaluated include the beta-adrenergic receptor system (using 11CGP-12177 as the ligand) and angiotensin converting enzyme (using 18F-fluorocaptopril). In each case, the object is to measure Bmax, or the maximum binding-capacity for the ligand in question. Changes in Bmax can be used to infer changes in protein expression of the receptor or enzyme, or can be used to quantify adequacy of therapy with inhibitor drugs. Given the highly active nature of the pulmonary endothelium, it is likely that many other pulmonary receptor or enzyme systems can be studied in a similar fashion.

Human surfactant proteins A1 and A2 are differentially regulated during development and by soluble factors

An RT-PCR method for the relative quantitation of the mRNAs for human surfactant protein (SP) A1 and SP-A2 was developed, verified, and then utilized to determine the relative levels of these mRNAs in fetal and adult lung samples in vivo, as well as in cultured human fetal lung explants and H441 cells. For the cultured tissue and cells, we assessed the effects of a variety of soluble factors known to modulate total SP-A. Comprehensive analysis revealed many significant findings, including the following: both mRNAs were expressed as early as 15 wk of gestation; throughout midgestation, SP-A1 was present at higher levels than SP-A2, with an average ratio of 30:1. In the adult lung, SP-A1 mRNA was present at lower levels than SP-A2, with a ratio of 0.4:1, whereas in H441 cells, the ratio was 0.85:1. In fetal lung cultured for 4 days, both mRNAs increased, with a greater increase in SP-A2 (97-fold) than in SP-A1 (15-fold), resulting in a final ratio of 4:1. Differential regulation was demonstrated for 8-(4-chlorophenylthio)-cAMP, interferon (IFN)-gamma, tumor necrosis factor-alpha, and transforming growth factor (TGF)-beta in the human fetal lung explant system, with SP-A2 being more affected, and for IFN-gamma and TGF-beta in the H441 cells, where SP-A1 showed greater regulation. Of the soluble factors tested, IFN-gamma and TGF-beta had the most potent and consistent effects in both systems.

Ischemic preconditioning enhances donor lung preservation in canine lung transplantation

OBJECTIVE

To prove the protective effect of lung ischemic preconditioning on enhancing the canine lung preservation and reducing allograft lung dysfunction after transplantation.

METHODS

Ten pairs of adult canines underwent left lung allotransplantation. Five donors were treated with ischemic preconditioning [their left hilus was clamped for 10 minutes and released for 15 minutes (Group IP)], and five donors were not treated with ischemic preconditioning (Group C). The donor lungs were flushed with 4 degrees C Euro-Collin's solution (ECS) and stored in the same solution for two and a half hour, then transplanted to the recipient canines, who were observed for one to two hours after transplantation. The lung venous blood of the recipient and the donor lung tissue were collected just after thoracotomy and one hour after reperfusion of the transplanted lung in both groups.

RESULTS

The number of polymorphonuclear (PMN) was significantly higher in Group IP than in Group C (P < 0.05). However, the number of PMN in lung interstitium under microscope was less in Group IP than in Group C. The thromboxane (TXB2), malondialdehyde (MDA) and mean pulmonary artery pressure (MPAP) contents were significantly lower in Group IP than in Group C (P < 0.05). The superoxide dismutase (SOD) and the lung venous blood oxygen tension (PvO2) contents were significantly higher in Group IP than in Group C (P < 0.05). Histological findings showed less damages in Group IP than in Group C.

CONCLUSIONS

The protective effect of ischemic preconditioning together with ECS flush and storage is superior to using ECS alone. The possible mechanisms may be that ischemic preconditioning inhibits the accumulation and activation of PMN in lung tissue and reduces the production of oxygen free radicals.

[Effect of TNF-alpha monoclonal antibody on tissue lipopolysaccharide-binding protein mRNA expression in rats after thermal injury]

OBJECTIVE

To explore the effects of tumor necrosis factor-alpha (TNF-alpha) monoclonal antibody (MAb) on tissue TNF-alpha and lipopolysaccharide-binding protein (LBP) mRNA expression, and multiple organ dysfunction in rats after thermal injury.

METHOD

24 male Wistar rats were subjected to a 35% total body surface area full-thickness thermal injury.

RESULT

The tissue TNF-alpha and LBP mRNA expressions of liver, lung, intestine, and kidney were markedly increased (P < 0.05 approximately equal 0.01) after thermal injury. Treatment with TNF-alpha MAb could significantly lower TNF-alpha mRNA expression of lung, intestine and kidney, but had no effect on liver TNF-alpha mRNA expression (P > 0.05). Similarly, the tissue LBP mRNA expression also decreased significantly (36.0% - 72.9%), and returned to normal in lung, intestine and kidney. In addition, biochemical parameters including GPT, TBiL, BUN, CK-MB, and LDH were markedly elevated after thermal injury, and decreased significantly after treatment with TNF-alpha MAb.

CONCLUSION

The increase of tissue TNF-alpha gene expression caused by thermal injury might be associated with a marked elevation of tissue LBP mRNA expression, which could contribute to the development of multiple organ dysfunction. The early use of TNF-alpha MAb seems to be effective in inhibiting significant LBP mRNA expression in various tissues and ameliorating multiple organ damage after major thermal injury.

Altered insulin-like growth factor I mRNA expression in human hypoplastic lung in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Insulin-like growth factor I (IGF-I) is a peptide growth factor that is synthesized in many organs during human development and plays a role in the growth and differentiation of tissue. IGF-I has been shown to be produced in rat and human fetal lung and to be an important mitogen involved in lung growth and development. The cells responsible for the synthesis of IGF-I in lung in vivo have been demonstrated to be type II pneumocytes, alveolar macrophages, and mesenchymal cells. Recent studies have shown that IGF-I mRNA expression in the lung is predominant during fetal life and decreases before birth, becoming barely detectable in the neonatal lung. The aim of this study was to investigate IGF-I mRNA expression in CDH lung to understand the basis of pulmonary hypoplasia in newborns with CDH.

METHODS

Lung tissue samples were obtained during autopsy from 13 patients with CDH. Nine were full-term newborns (mean age, 3.8 days), and four were stillborns. Normal lung tissue from eight sudden infant death syndrome infants (mean age, 15.3 days) acted as controls. In situ hybridization was performed on frozen sections using IGF-I-specific and digoxigenin-labeled oligonucleotide probe and visualized by nitro blue tetrazolium staining.

RESULTS

In control lung, IGF-I mRNA expression was absent or weak in type II pneumocytes and alveolar macrophages. In contrast, there was strong IGF-I mRNA expression in type II pneumocytes and alveolar macrophages in hypoplastic CDH lung in newborns as well as stillborns.

CONCLUSION

The findings of strong IGF-I mRNA expression in the hypoplastic lung suggest that lung hypoplasia in CDH is a persistence of fetal stage of lung development.

Filtration of diaspirin crosslinked hemoglobin into lung and soft tissue lymph

Diaspirin crosslinked hemoglobin (DCHb) is a new blood substitute manufactured from human blood. To evaluate its microvascular filtration properties, we infused DCLHb into unanesthetized sheep (10%, 20 ml/kg) and measured the flow and composition of lung and soft tissue lymph. For comparison, we also infused human serum albumin (HSA; 10%, 20 ml/kg). DCLHb raised systemic and pulmonary arterial pressures from baseline values of 83 +/- 7 and 13 +/- 2 mm Hg, respectively, to peak values of 113 +/- 9 and 26 +/- 3 mm Hg (p < 0.05 versus baseline). These increases were significantly greater than those associated with HSA, which raised systemic and pulmonary arterial pressures from baseline values of 86 +/- 4 and 13 +/- 2 mm Hg, respectively, to peak values of 97 +/- 3 and 21 +/- 7 mm Hg (p <= 0.05 versus baseline and versus DCLHb). These differences reflect the known pressor properties of DCLHb. Accordingly, DCLHb raised lung and soft tissue lymph flows to peak values of 12.2 +/- 3.8 and 1.6 +/- 0.7 ml/30 min, respectively, while HSA raised lung and soft tissue lymph flows to peak values of 7.5 +/- 4.8 and 4.6 +/- 1.9 ml/30 min, respectively (p <= 0.05 versus DCLHb). The half-times of DCLHb equilibration from plasma into lung and soft tissue lymph of 1. 0 +/- 0.3 and 2.1 +/- 1.1 h, respectively, were significantly faster than HSA equilibration half-times of 3.1 +/- 0.2 and 3.8 +/- 0.9 h. Filtration differences between DCLHb and HSA appear to be due to the pressor properties DCLHb.

Distinct tumor necrosis factor-alpha responses in alveolar and peritoneal macrophages are associated with local levels of endotoxin

Tumor necrosis factor alpha (TNF-alpha) responses of alveolar macrophages (AMs) and peritoneal macrophages (PMs) were studied in rats after intravenous injection of lipopolysaccharide (LPS). High levels of plasma TNF-alpha, increased pulmonary myeloperoxidase activity, and leukopenia occurred within 2 h after LPS injection. Alveolar spaces exhibited a strict compartment property, as manifested by only slightly increased LPS and TNF-alpha levels in alveolar lavage fluid and an unchanged capacity of AMs to produce TNF-alpha. By contrast, the peritoneal cavity had greatly increased local LPS and TNF-alpha levels and a diminished PMs TNF-alpha response to LPS. The amount of LPS in the alveolar spaces was less than 0.2% of the level in peritoneal fluid. These results indicate that activation of resident macrophages is dependent on the amounts of local LPS and, in addition, suggest that resident AMs neither participate in the plasma TNF-alpha response nor contribute to neutrophil sequestration in the lung during the early stages of endotoxemia.

Bud formation precedes the appearance of differential cell proliferation during branching morphogenesis of mouse lung epithelium in vitro

Cell proliferation is an essential requirement for epithelial expansion and tubular branching; however, little is known of how these events are coupled during morphogenesis. We have previously shown that, in the absence of mesenchyme, fibroblast growth factor 1 (FGF-1) elicits budding of the mouse lung epithelium cultured in a basement membrane matrix. Although bud formation seems to be the manifestation of a localized response of lung epithelial cells to FGF-1, it is unclear whether budding results from induction of differential rates of cell proliferation within the epithelium. We performed continuous labeling and pulse-chase experiments in FGF-1-treated mesenchyme-free lung epithelial cultures at distinct stages of bud induction using bromodeoxyuridine (BrdU), to determine when and to what extent cell proliferation contributes to bud formation. When explants were incubated with BrdU either before bud induction (0-18 hr in culture) or at the onset of budding (24-30 hr), labeled nuclei were found distributed throughout the entire explant. In contrast, BrdU incubation after the onset of budding (30-48 hr) resulted in labeling concentrated in the budding areas, and a decrease of labeling toward the proximal region of the explant, between buds. These results demonstrate that differential rates of cell proliferation between bud and nonbud areas do not appear until when buds are almost completely formed. Thus, in the developing lung epithelium in vitro, bud outgrowth is not triggered by induction of localized cell proliferation.

[Effect of tetrandrine on the collagen contents of lungs in rats with chronic hypoxia]

OBJECTIVE

To investigate the effect of tetrandrine (Tet) on the collagen contents of lung tissues in rats with chronic hypoxic pulmonary hypertension.

METHOD

Using colorimetric method after oxidized by chloramine T to determine hydroxyproline contents of lung tissues and extrapulmonary arteries, using Masson method, image pattern analysis technique and gray scale scanning to observe the changes of collagen distribution in extrapulmonary arteries and lung tissues in rats with hypoxia and the effect of treatment with Tet.

RESULT

Tet could remarkably reduce the mean pulmonary arterial pressure and pulmonary vascular resistance in rats with hypoxic pulmonary hypertension and could inhibit the increase of collagen contents in lung tissues and extrapulmonary arterial wall.

CONCLUSION

Tet may be used as one of the main drugs in the treatment of chronic hypoxic pulmonary hypertension due to its action of reducing mPAP and collagen contents.

Regulation of extracellular matrix synthesis by TNF-alpha and TGF-beta1 in type II cells exposed to coal dust

Type II pulmonary epithelial cells respond to anthracite coal dust PSOC 867 with increased synthesis of extracellular matrix (ECM) components. Alveolar macrophages modulate this response by pathways that may involve soluble mediators, including tumor necrosis factor-alpha (TNF-alpha) or transforming growth factor-beta1 (TGF-beta1). The effects of TNF-alpha (10 ng/ml) and/or TGF-beta1 (2 ng/ml) were thus investigated in dust-exposed primary type II cell cultures. In control day 1 or day 3 cultures, TNF-alpha and/or TGF-beta1 had little or no effect on the synthesis of type II cellular proteins, independent of whether the cells were exposed to dust. With PSOC 867 exposure, where ECM protein synthesis is elevated, TNF-alpha and TGF-beta1 further increased both the absolute and relative rates of ECM synthesis on day 3 but had little effect on day 1. Each mediator increased expression of fibronectin mRNA, as well as of ECM fibronectin content, in a manner qualitatively similar to their effects on synthesis. Thus TNF-alpha and TGF-beta1 modulate both ECM synthesis and fibronectin content in coal dust-exposed type II cell cultures.