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Biomedical subjects

J Gauldie

Publications and source records attributed to J Gauldie.

At least 181 records · Page 10Linked to original sources
PubMed1989

Antigen-induced lung solute clearance in rats is dependent on capsaicin-sensitive nerves.

Chemosensitive sensory nerves have an important effector role in the control of vascular permeability in rat airways after neurogenic inflammation. To investigate whether they also have a role in antigen-induced lung inflammation, we have studied the changes in lung solute clearance (LSC) in sensitized rats after aerosol challenge with allergen and the effect of prior capsaicin-induced denervation on these changes. Sprague-Dawley rats were immunized with egg albumin (EA), using aluminum hydroxide and Bordetella pertussis as adjuvants. After 11 days, the animals were challenged for 5 min with aerosolized EA, and the clearance from the lungs of aerosolized 99mTc diethylenetriamine pentaacetic acid (99mTc-DTPA) over 7.5 min (LSC 7.5) was subsequently measured at various times after challenge as an index of epithelial permeability or integrity. Sensitized animals responded to the challenge with immediate respiratory symptoms and with an increased 99mTc-DTPA clearance rate that was detectable at 20 min (mean +/- SE LSC 7.5: baseline, 6 +/- 1%; 20 min, 17 +/- 3%; p less than 0.05), persisted at 4 h (14 +/- 1%; p less than 0.05), and returned to normal values after 24 h. Unsensitized rats exposed to EA and sensitized rats exposed to PBS or to bovine serum albumin did not show any change. Bronchoalveolar lavage failed to show significant changes of cell populations until 24 h, when an increased presence of lymphocytes, PMN, and eosinophils was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1989

Human lung fibroblast-derived granulocyte-macrophage colony stimulating factor (GM-CSF) mediates eosinophil survival in vitro.

Tissue eosinophilia has been reported to occur in pulmonary fibrosis, a disease characterized by chronic inflammation and lung fibroblast proliferation. We have examined the in vitro interaction of these two cell types by determining the in vitro survival of human peripheral blood eosinophils co-cultured with human lung fibroblasts. Survival of eosinophils cultured alone was 10% at day 3 and less than 1% at day 7. In contrast, survival of eosinophils that had been co-cultured with fibroblasts was 98, 90, 73, and 69% at days 3, 7, 10, and 14, respectively. Fibroblast-conditioned medium (CM) elicited a similar result in a dose-dependent fashion. Survival of eosinophils cultured with CM which had been preincubated with a monoclonal-neutralizing antibody to human GM-CSF was inhibited in a dose-dependent manner. Human recombinant-derived GM-CSF supported eosinophil survival in the dose-dependent fashion. Survival at day 7 of eosinophils treated with one single dose of GM-CSF (10 U/ml) was 64%. The effect of fibroblast-CM on eosinophils likely represents true survival since eosinophil proliferation as determined by [3H]thymidine incorporation did not occur. We also report that freshly isolated eosinophils had normal ultrastructural, scanning and transmission electron microscopy characteristics, and were normodense. In contrast, eosinophils co-cultured for 7 days with fibroblasts acquired irregular shapes and became hypodense and partially degranulated. Thus, our results indicate that human lung fibroblast-derived GM-CSF mediates the in vitro survival of human eosinophils.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1989

Hormonal regulation and tissue-specific localization of alpha 2-macroglobulin in rat ovarian follicles and corpora lutea.

alpha 2-Macroglobulin (alpha 2M) is a broad spectrum protease inhibitor associated with inflammatory responses and proposed to be important in tissue remodeling. alpha 2 M also functions as a carrier of specific growth factors and cytokines, including platelet-derived growth factor, transforming growth factor-beta, basic fibroblast growth factor, interleukin-1, interleukin-6. To determine whether alpha 2M is associated with remodeling phenomena in the rat ovary, the expression of alpha 2M mRNA and protein has been analyzed in specific ovarian cell types during ovulation, luteinization, and luteolysis. Before ovulation, alpha 2M mRNA is not detectable in granulosa cells. Twelve hours after injection of an ovulatory dose of hCG a 5.2-kilobase alpha 2M mRNA is detectable in luteinizing follicles, which is increased further by 48 h and maintained in corpora lutea (CL) for up to 96 h. Administration of PRL from 24-96 h results in both inhibition of luteolysis and marked increases in alpha 2M mRNA in CL, but not in residual tissues, of these same ovaries, isolated 48, 72, and 96 h after an ovulatory dose of hCG, alpha 2M mRNA is also induced by PRL in cultures of luteinized granulosa cells. These changes in alpha 2M mRNA in follicles or developing CL do not appear to reflect the amount of alpha 2M protein present: alpha 2M protein (188K monomer) is present (immunoblot and immunofluorescence data) in small antral and preovulatory follicles even though mRNA is not detectable; after an ovulatory dose of hCG the protein level transiently increases by 12 h (approximately 5-fold) and declines thereafter through 96 h; the decrease in alpha 2M protein observed at 48-96 h is delayed but not abolished by treatment with PRL, even though the mRNA levels continue to rise during this same time period. In contrast, changes in alpha 2M mRNA and protein are regulated coordinately in CL of pregnant rats. alpha 2M mRNA is present, but in low concentration, from days 4-11 of gestation, increases markedly between days 11-21, and decreases at parturition, when functional luteolysis occurs. Hysterectomy of day 10 pregnant rats combined with hormone replacement determined that alpha 2M mRNA levels are regulated primarily by PRL through day 12 and by placental lactogens during midgestation (days 12-15). The increase in alpha 2M mRNA during pregnancy precedes the 40-fold increase (peak) in a alpha 2M protein observed on day 15, which remains elevated through day 21.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Leukocyte endogenous mediator fails to alter protein dynamics in a model of liver dysfunction.

This study examines the effect of a purified leukocyte-derived endogenous mediator (LEM) on protein metabolism during liver dysfunction and after sham surgery and the role of a nonsteroidal, antiinflammatory drug (indomethacin sodium trihydrate) in modifying this response. Febrile response, protein kinetics, urinary end products of protein metabolism, and plasma acute phase protein levels were studied in rats given a pyrogenic dose of LEM or saline solution, and these same indicators were studied after the administration of the same dose of LEM plus 2 mg/kg indomethacin 3 weeks after a portacaval shunt (PCS) or sham operation. In both surgical groups given LEM, a maximum of 1.1 degrees C fever was observed. LEM increased protein turnover and urinary excretion of nitrogen and urea in sham-operated rats but not in the PCS animals. Administration of indomethacin decreased the plasma oxidation of L[1-14C]leucine and prevented the increased excretion of total nitrogen and urea in sham-operated animals treated with LEM. PCS animals showed a constant excretion of nitrogen and urea independent of treatment. alpha 1-Acid glycoprotein levels increased significantly in sham-operated animals treated with LEM but not in the PCS group until indomethacin was added. The coadministration of LEM and indomethacin in shams also enhanced the levels of alpha 2-macroglobulin and alpha 1-acid glycoprotein over values found with LEM alone. These findings confirm the catabolic effect of LEM in normal animals and identify the essential role of the liver in the acute phase response. The data also suggest that indomethacin may modify the acute phase response by reducing plasma amino acid oxidation as well as enhancing the levels of some specific acute phase proteins.

Acute-Phase Proteins↗
PubMed1988

An association between schistosomes and contrapsin, a mouse serine protease inhibitor (serpin).

An antigen in homogenates of adult Schistosoma mansoni worms grown in mice, and immunoprecipitated by polyspecific rabbit antiserum, has been identified as contrapsin, a mouse serine protease inhibitor (serpin). In the serum of some mice infected with S. mansoni contrapsin was found with altered immunoelectrophoretic characteristics when compared with contrapsin from uninfected mice.

Animals↗
PubMed1988

Effect of histamine on proliferation of normal human adult lung fibroblasts.

Fibrotic lung tissue shows increased connective tissue deposition and fibroblast proliferation and in addition a substantial increase in mast cell numbers in and around the fibrotic area. To elucidate the question of whether products of mast cells affect the proliferative behaviour of structural cells in the lung and thereby contribute to fibrogenesis, the effect of histamine, a prominent mast cell derived mediator, on the in vitro proliferation of primary cultures of normal adult human lung fibroblasts was studied. Histamine enhanced fibroblast proliferation in a dose dependent manner, with an optimum effect at a physiological concentration of 10(-7) mol/l. This effect occurred when cells were exposed to histamine at restricted times during cell growth and was shown to depend in part on the stage of the cell cycle reached by the fibroblasts. The histamine induced proliferation was mediated through an H2 histamine receptor on the fibroblast, being inhibited by cimetidine, an H2 antagonist, and not by pyrilamine maleate, an antagonist of the H1 receptor. Mast cell products such as histamine may interact with and promote the increased fibroblast proliferation found in pulmonary fibrosis.

Adult↗
PubMed1988

Heterogeneous proliferative characteristics of human adult lung fibroblast lines and clonally derived fibroblasts from control and fibrotic tissue.

Pulmonary fibrosis results from an altered deposition of collagen within the lung parenchyma. This alteration is likely the result of both increased fibroblast proliferation and abnormalities in fibroblast collagen metabolism. Although the development of pulmonary fibrosis is preceded by inflammatory events in the lung, it is unclear whether altered fibroblast behavior requires continuous exposure to inflammatory mediators or alternatively results from the emergence in the lung of fibroblast populations possessing characteristics such as to explain the abnormalities seen in pulmonary fibrosis. To examine the latter hypothesis, we have established a number of fibroblast cell lines from control (C) lung tissue as well as from tissue from patients with active pulmonary fibrosis (PF), and have examined their in vitro proliferative characteristics. Our data show that PF fibroblasts proliferate significantly faster compared to C fibroblasts under standard culture conditions. We have also examined the in vitro proliferative characteristics of a substantial number of clonally derived fibroblasts. We report that a marked heterogeneity exists in terms of proliferation and also that a small but significant number of fast-growing clones are present in panels of clones derived from fibrotic tissue. These data suggest that there exists in fibrotic tissue, clones of fibroblasts with intrinsic growth characteristics which could in itself explain the increased fibroblast proliferation seen in pulmonary fibrosis. The fibrotic clones may emerge as dominant in the fibrotic lung under conditions of injury and repair likely to favor the expansion of this phenotype.

Adult↗
PubMed1988

Spontaneous in vitro release of alveolar-macrophage cytokines after the intratracheal instillation of bleomycin in rats. Characterization and kinetic studies.

The intratracheal administration of bleomycin in rats elicits an acute inflammatory response in the lung followed by the development of pulmonary fibrosis. The alveolar macrophage (AM) is a key effector cell involved in this process because of its potential to release a variety of hormonelike molecules (cytokines) that can modulate systemic responses as well as the local response of other lung cells including the interstitial fibroblast. In this report, we have documented the chronology of the in vitro spontaneous release of AM cytokines after a single instillation of bleomycin. We show that supernatants from AM harvested after the administration of bleomycin but not after saline contain lymphocyte-activating factor (interleukin-1) activity. Maximal activity was detected between 6 and 12 h and was barely detectable by Day 7 after bleomycin. In addition, supernatants showing interleukin-1 (IL-1) activity also inhibited the proliferation of log-phase normal rat lung fibroblasts. Fractionation of supernatants from AM harvested 6 h after bleomycin demonstrated that both lymphocyte-activating factor and fibroblast modulatory activity coelute in the same 18-kDa region, suggesting that IL-1 may demonstrate both activities. We also report here the spontaneous release of a second AM cytokine, hepatocyte-stimulating factor, which we have recently shown in humans to be identical to interferon beta 2 and which initiates the hepatic acute-phase protein response. The release of this 30-kDa cytokine from AM of rats exposed to bleomycin has a different chronology than does IL-1, showing a steady increase over time, with maximal activity at Day 28 after bleomycin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Solute movement across the alveolar-capillary membrane after intratracheally administered bleomycin in rats.

The rate of absorption across the alveolar-capillary membrane of inhaled 99mTc-DTPA and the concentration of albumin in the bronchoalveolar lavage (BAL) fluid were characterized in a rat model of bleomycin-induced pulmonary fibrosis. Adult male Lewis rats were studied from 1 h to 120 days after a single intratracheal instillation of bleomycin (0.5 to 0.6 U/100 g body weight). The retention of 99mTc-DTPA in the lungs, expressed as a percentage of the baseline radioactivity, was determined at 15 min (%R15) after delivery of the tracer. The %R15 was 83.7 +/- 6.0 for normal untreated rats and 84.3 +/- 3.7 for saline-treated animals. The rate of absorption of 99mTc-DTPA began to increase 24 h after bleomycin, reaching a maximum at Day 7, with %R15 = 56.0 +/- 6.5 (p less than 0.0001). Resolution to control values occurred by Day 34 after bleomycin. At Day 45 after bleomycin, the rate of absorption of 99mTc-DTPA was slower than sham (control), with %R15 = 89.2 +/- 1.9 (p less than 0.5). However, from Day 63 onwards, removal was not different from control. The concentration of albumin in the BAL fluid began to increase 48 h after bleomycin, was 10-fold greater than control by Day 7 (150 +/- 38 versus 16 +/- 3 micrograms/ml), and returned to control values by Day 28. The percentage of neutrophils in the BAL increased at 12 h, reached a plateau of 33 +/- 9% between 4 and 7 days, and then returned to control values by Day 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1988

Inhibitory effect of human recombinant interferon gamma on synthesis of acute phase proteins in human hepatoma Hep G2 cells stimulated by leukocyte cytokines, TNF alpha and IFN-beta 2/BSF-2/IL-6.

Supernatants from endotoxin-stimulated human leukemic cells and human recombinant interferon-beta 2 similarly enhance synthesis of alpha 1-antichymotrypsin and haptoglobin but suppress synthesis of albumin in cultured Hep G2 cells. Human recombinant tumor necrosis factor only slightly affects production of alpha 1-antichymotrypsin and albumin in a similar manner as leukocyte cytokines. In distinction, recombinant human interferon-gamma profoundly inhibits synthesis of alpha 1-antichymotrypsin, and especially of haptoglobin, but stimulates production of alpha 2-macroglobulin thus modulating the acute phase response of these cells.

Acute-Phase Proteins↗
PubMed1988

The cascade of inflammatory cytokines regulating synthesis of acute phase proteins.

The acute phase cytokines: interleukin 1, tumor necrosis factor alpha (cachectin) and beta (lymphotoxin), hepatocyte stimulating factor and several interferons, all belong to the family of endotoxin-inducible, low molecular weight proteins. Their synthesis in macrophages, fibroblasts, lymphocytes, epithelial and some tumor cells is enhanced by the same cytokines, often in the autocrine manner, and suppressed by dexamethasone. The principal hepatocyte stimulating factor (HSF) regulating synthesis of acute phase proteins is probably identical with IFN-beta 2/BSF-2/IL-6, but other inflammatory cytokines (IL-1, TNF alpha, IFN-gamma) are able to induce distinct sets of acute phase proteins, or to modulate the final response pattern. The effect of hrIFN-gamma on production of acute phase proteins by human hepatoma Hep G2 cells is discussed in detail. It is concluded that the cascades of inflammatory cytokines in different tissues represent amplification and regulatory pathways controlling the development of acute phase response in vivo.

Acute-Phase Proteins↗
PubMed1988

A novel monoclonal antibody based diagnostic test for alpha-thalassemia-1 carriers due to the (-SEA/) deletion.

The presence of minute amounts of embryonic zeta-globin chains in adult hemolysates is a marker for carriers of alpha-thalassemia-1 resulting from (--SEA/) deletion. Recently, we developed a murine monoclonal antihuman embryonic zeta-globin chain antibody, 8E8. By using this antibody, we have now established a slot-blot immunobinding assay for the rapid detection of zeta-globin chains in adult hemolysates. zeta-globin chains were found to be present in 30 blood samples obtained from individuals who were carriers of alpha-thalassemia-1. In another 30 blood samples from individuals who were not carriers of the (--SEA/) deletion, zeta-globin chains were not detected. This simple diagnostic test can be used in appropriate populations to identify those couples at risk of conceiving fetuses afflicted with the Hb Bart's hydrops fetalis syndrome due to homozygous alpha-thalassemia.

Antibodies, Monoclonal↗
PubMed1987

Interaction among hepatocyte-stimulating factors, interleukin 1, and glucocorticoids for regulation of acute phase plasma proteins in human hepatoma (HepG2) cells.

Human hepatoma (HepG2) cells respond to unfractionated conditioned media of human squamous carcinoma (COLO-16) cells and lipopolysaccharide-stimulated human peripheral blood monocytes by increasing the synthesis of alpha 1-acid glycoprotein, haptoglobin, complement C3, alpha 1-antichymotrypsin, alpha 1-antitrypsin, and fibrinogen, while decreasing the synthesis of albumin. The regulation of the acute phase proteins is mediated by hepatocyte-stimulating factors (HSF) and interleukin 1 (IL-1) present in the conditioned medium. Purified HSF-I from COLO-16 cells stimulates preferentially alpha 1-acid glycoprotein synthesis, whereas COLO-HSF-II stimulates preferentially the synthesis of haptoglobin, fibrinogen, and alpha 1-antitrypsin. HSF from monocytes, which has been identified as interferon-beta 2 (B cell stimulating factor-2), displayed the same activity as COLO-HSF-II. Dexamethasone alone had no effect on acute phase plasma protein synthesis but enhanced the response to various HSF severalfold. IL-1 had a relatively low stimulatory activity on the synthesis of alpha 1-acid glycoprotein, haptoglobin, and alpha 1-antichymotrypsin but strongly reduced the basal expression of fibrinogen. The only synergistic action between IL-1 and HSF (or interferon-beta 2) was noted for the synthesis of alpha 1-acid glycoprotein. Tumor necrosis factor active on other hepatic cells failed to modulate significantly the expression of any plasma proteins in HepG2 cells. These studies showed that for an optimal HepG2-cell response a combination of HSF (or interferon-beta 2), IL-1, and dexamethasone is needed. This finding might indicate the identity of some of those hormones involved in regulation of the hepatic acute phase response in vivo.

Acute-Phase Proteins↗
PubMed1987

Distinct sets of acute phase plasma proteins are stimulated by separate human hepatocyte-stimulating factors and monokines in rat hepatoma cells.

A subline of the rat hepatoma (H-35) cells has been identified which responds to hepatocyte-stimulating factors (HSFs) of human squamous carcinoma cells by increased synthesis of all major rat acute phase plasma proteins. The regulation occurs at the level of mRNA. Two HSFs (HSF-I and HSF-II) have been purified from conditioned medium of the squamous carcinoma cells. HSF-I is a protein with an Mr = 18,000 and pI 5.5, and HSF-II is a glycoprotein with an Mr = 34,000 and a broad, neutral to basic charge. In H-35 cells, HSF-I predominantly stimulates the synthesis of complement C3 and haptoglobin and acts synergistically with dexamethasone to stimulate alpha 1-acid glycoprotein. HSF-II stimulates cysteine protease inhibitor, alpha 1-antichymotrypsin, alpha 1-antitrypsin, fibrinogen, and hemopexin, and acts synergistically with dexamethasone to stimulate alpha 2-macroglobulin. Each HSF is between 10 and 100 times less effective in regulating proteins of the other set. Human tumor necrosis factor and interleukin-1 increase complement C3, haptoglobin, and alpha 1-acid glycoprotein, as does HSF-I, but are unable to modulate any of the other acute phase proteins. The monokines differ from HSF-I is their low activity in HepG2 cells and rat hepatocytes.

Acute-Phase Proteins↗