Biomedical subjects

E M Berger

Publications and source records attributed to E M Berger.

At least 37 records · Page 2Linked to original sources

PubMed1989

Dimethylthiourea prevents hydrogen peroxide and neutrophil mediated damage to lung endothelial cells in vitro and disappears in the process.

Dimethylthiourea (DMTU) progressively disappeared following reaction with increasing amounts of hydrogen peroxide (H2O2) in vitro. DMTU disappearance following reaction with H2O2 was inhibited by addition of catalase, but not aminotriazole-inactivated catalase (AMT-catalase), superoxide dismutase (SOD), mannitol, benzoate or dimethyl sulfoxide (DMSO) in vitro. By comparison, DMTU disappearance did not occur following addition of histamine, oleic acid, elastase, trypsin or leukotrienes in vitro. Addition of DMTU also decreased H2O2-mediated injury to bovine pulmonary artery endothelial cells (as reflected by LDH release) and DMTU disappeared according to both added amounts of H2O2 and corresponding degrees of injury. DMTU disappearance was also relatively specific for reaction with H2O2 in suspensions of endothelial cells where it was prevented by addition of catalase, but not AMT-catalase or SOD and did not occur following sonication or treatment with elastase, trypsin or leukotrienes. Addition of washed human erythrocytes (RBC) also prevented both H2O2 mediated injury and corresponding DMTU decreases in suspensions of endothelial cells. In addition, phorbol myristate acetate (PMA) and normal neutrophils, but not O2 metabolite deficient neutrophils from patients with chronic granulomatous disease (CGD), caused DMTU disappearance in vitro which was decreased by simultaneous addition of catalase, but not SOD, sodium benzoate or DMSO. Finally, addition of normal neutrophils (but not CGD neutrophils) and PMA caused DMTU disappearance and increased the concentrations of the stable prostacyclin derivative (PGF1 alpha) in supernatants of endothelial cell suspensions. In parallel, DMTU also decreased PMA and neutrophil-mediated PGF1 alpha increases in supernatants from endothelial cell monolayers. Our results indicate that DMTU can decrease H2O2 or neutrophil mediated injury to endothelial cells and that simultaneous measurement of DMTU disappearance can be used to improve assessment of the presence and toxicity of H2O2 as well as the H2O2 inactivating ability of scavengers, such as RBC, in biological systems.

Animals↗

PubMed1989

Polyethylene glycol-attached antioxidant enzymes decrease pulmonary oxygen toxicity in rats.

When exposed continuously to hyperoxia (100% O2, 760 Torr barometric pressure), rats pretreated with polyethylene glycol (PEG)-attached superoxide dismutase and catalase (PEG-SOD + PEG-CAT) lived longer (79.1 + 7.6 h) than rats pretreated with saline (60.7 +/- 2.1 h) or PEG-inactivated-SOD + PEG-inactivated-CAT (62.3 +/- 1.6 h). Rats pretreated with PEG-SOD + PEG-CAT also had less hyperoxia-induced acute oxidative edematous lung injury, as assessed by increases in lung oxidized glutathione (GSSG) contents, pleural effusions, and lung lavage albumin concentrations than saline-pretreated rats. Rats pretreated with the long-lived conjugates PEG-inactivated-SOD + PEG-inactivated-CAT or PEG-albumin also had decreased acute oxidative edematous lung injury compared with rats pretreated with PEG, SOD + CAT + PEG, SOD + CAT, or saline. In vitro studies suggested that PEG itself may have contributed to protection by scavenging hydroxyl radical (.OH) but not superoxide (O2-.) or H2O2. Compared with more effective endogenous (via preexposure to hypoxia) or exogenous (via liposomes) means for increasing lung antioxidant enzymes, PEG enzymes are less protective against lung injury from continuous hyperoxia.

Animals↗

PubMed1989

Blood sulfhydryl level increases during hyperoxia: a marker of oxidant lung injury.

Blood acid-soluble sulfhydryl, but not glutathione (GSH), levels increased during the development of acute edematous lung injury in rats exposed to normobaric hyperoxia for 48 h or more. A relationship between increases in blood sulfhydryl levels, lung injury, and O2 metabolite generation during exposure to hyperoxia was suggested by two observations. First, increases in blood sulfhydryl levels occurred simultaneously with increases in lung oxidized glutathione (GSSG) levels and lung GSSG-to-GSH ratios (GSSG/GSH). Second, hyperoxia-induced increases in blood sulfhydryl levels, blood hematocrits, pleural effusion volumes, lung GSSG levels, and lung GSSG/GSH were decreased by pretreating rats with dimethylthiourea (DMTU), an O2 metabolite scavenger. Our findings indicate that exposure of rats to hyperoxia increases blood acid-soluble sulfhydryl levels in vivo and that increases in blood sulfhydryl levels may provide an accessible marker of increased oxidant exposure and/or oxidant-mediated lung injury.

Animals↗

PubMed1988

Small increases in pH decrease uptake of Escherichia coli by human neutrophils in vitro.

Increases in pH from 7.4 to 7.8 decreased the ability of human neutrophils in serum to ingest and kill Escherichia coli ATCC 29552 in vitro. In contrast, similar increases in pH did not decrease the bactericidal activity of neutrophils in serum against Staphylococcus aureus 502A. Increases in pH did not alter opsonization of E. coli by serum or the growth of E. coli but rather appeared to alter neutrophil uptake of bacteria by a direct effect on the neutrophil.

Escherichia coli↗

PubMed1988

Variable effect of toxic shock toxins from different sources on neutrophil function in vitro.

Toxic shock syndrome toxins (TSST) are 23-30 kD proteins that have been isolated from incubation media of strains of Staphylococcus aureus cultured from patients with toxic shock syndrome (TSS). Injection of TSST into animals produces many of the symptoms that characterize TSS including shock, fever, and multiple organ failure. We found that addition of increasing concentrations of TSST-1-VP1035-16A, but not TSST-PEC, TSST-SEC, staphylococcal enterotoxin A or B, progressively decreased human neutrophil bactericidal activity against S. aureus, 502A in vitro. TSST-1-VP1035-16A, but not the other toxins, also decreased superoxide anion and hydrogen peroxide concentrations in mixtures containing neutrophils and phorbol myristate acetate (PMA) in vitro. The results indicate that various preparations of TSST have different effects on neutrophil function in vitro and, accordingly, may have different effects in other in vitro and in vivo models of TSS.

Bacterial Toxins↗

PubMed1988

Thiourea and dimethylthiourea decrease human neutrophil bactericidal function in vitro.

Addition of thiourea (TU) or dimethylthiourea (DMTU) decreased killing of Staphylococcus aureus, 502A, and decreased concentrations of hydrogen peroxide (H2O2), and hydroxyl radical (.OH), but not superoxide anion (O2-.) or lysozyme concentrations, in mixtures containing human neutrophils in vitro. Addition of TU or DMTU also decreased concentrations of H2O2, .OH, or hypochlorous acid (HOCl) in neutrophil-free mixtures exposed to beta-D-glucose and glucose oxidase, gamma irradiation, or HOCl, respectively. Our results suggest that TU or DMTU can decrease neutrophil-mediated killing of bacteria by inhibiting O2 metabolite-dependent bactericidal mechanisms.

Blood Bactericidal Activity↗

PubMed1988

Xanthine oxidase-derived hydrogen peroxide contributes to ischemia reperfusion-induced edema in gerbil brains.

The contribution of toxic O2 metabolites to cerebral ischemia reperfusion injury has not been determined. We found that gerbils subjected to temporary unilateral carotid artery occlusion (ischemia) consistently developed neurologic deficits during ischemia with severities that correlated with increasing degrees of brain edema and brain H2O2 levels after reperfusion. In contrast, gerbils treated just before reperfusion (after ischemia) with dimethylthiourea (DMTU), but not urea, had decreased brain edema and brain H2O2 levels. In addition, gerbils fed a tungsten-rich diet for 4, 5, or 6 wk developed progressive decreases in brain xanthine oxidase (XO) and brain XO + xanthine dehydrogenase (XD) activities, brain edema, and brain H2O2 levels after temporary unilateral carotid artery occlusion and reperfusion. In contrast to tungsten-treated gerbils, allopurinol-treated gerbils did not have statistically significant decreases in brain XO or XO + XD levels, and reduced brain edema and brain H2O2 levels occurred only in gerbils developing mild but not severe neurologic deficits during ischemia. Finally, gerbils treated with DMTU or tungsten all survived, while greater than 60% of gerbils treated with urea, allopurinol, or saline died by 48 h after temporary unilateral carotid artery occlusion and reperfusion. Our findings indicate that H2O2 from XO contributes to reperfusion-induced edema in brains subjected to temporary ischemia.

Allopurinol↗

PubMed1987

Neutrophil-derived oxygen metabolites stimulate thromboxane release, pulmonary artery pressure increases, and weight gains in isolated perfused rat lungs.

Addition of normal human neutrophils and the neutrophil stimulant, phorbol myristate acetate (PMA), caused perfusate thromboxane (TXB2) elevations, pulmonary artery pressure (PAP) increases, and lung weight gains in isolated perfused rat lungs. Addition of PMA and neutrophils that do not generate O2 metabolites from a patient with chronic granulomatous disease (CGD) - or addition of PMA and normal neutrophils with the purported O2 metabolite scavenger, dimethylthiourea (DMTU) - also caused PAP increases but did not cause perfusate TXB2 elevations or lung weight gains in isolated lungs. In parallel, mixtures of normal neutrophils and PMA made hydrogen peroxide (H2O2) concentrations in vitro which exceeded concentrations found in mixtures containing PMA and CGD neutrophils or mixtures containing PMA, normal neutrophils, and DMTU. TXB2 levels were not detectable in mixtures containing normal neutrophils and PMA in vitro. Our results indicate that neutrophil-derived O2 metabolites contribute to perfusate TXB2 elevations and lung weight gains but not PAP increases in isolated perfused rat lungs.

Animals↗

PubMed1986

Deletion polymorphism in a Drosophila melanogaster heat shock gene.

We have continued the transcriptional analysis of the region of cytological locus 67B that contains the four small heat shock genes and other genes. Transcription from one of the heat shock genes in the region, hsp 26, takes place during high temperature treatment and at certain developmental stages, without heat shock, in several tissues, such as imaginal discs and adult ovaries. Observations of unexpected products after nuclease protection experiments provided the first indication of what genomic blot experiments showed to be small deletions. The alleles containing the deletion are expressed at the same level as the wild type allele. The deletion shortens the protein product, implying that it is in the coding region. Furthermore, flies homozygous for one of the deletion alleles are viable.

Alleles↗

PubMed1986

Persistent bactericidal defect in neutrophils from a young woman who recovered from toxic shock syndrome.

We have previously found transient menstruation-associated abnormalities in the in vitro bactericidal function of neutrophils from females who have recovered from toxic shock syndrome (TSS). We now report the case of a young woman who has also recovered from TSS, but who has a persistent, non-menstruation-associated defect in the ability of her neutrophils to kill Staphylococcus aureus in vitro.

Adolescent↗

PubMed1986

Increased incidence of menstruation-associated bactericidal defects in neutrophils from women who have recovered from toxic shock syndrome.

There is a growing suspicion that a host abnormality may contribute to the pathogenesis of toxic shock syndrome (TSS). We found that females (5 of 5) who had recovered from TSS had transient, menstruation-associated decreases (greater than or equal to 9%) in the ability of their neutrophils to kill Staphylococcus aureus. 502A in vitro more often (P = 0.040 by Fisher's exact test) than non-TSS-affected control subjects (5 of 12). In addition, the average decrease in bactericidal activity in neutrophils obtained during menstruation from recovered TSS patients was 30 +/- 9% compared to 7 +/- 7% for neutrophils from non-TSS-affected control subjects. The results are consistent with the possibility that transient menstruation-associated decreases in neutrophil bactericidal function may indicate susceptibility and/or contribute to the development of TSS.

Adult↗

PubMed1986

Natural and synthetic heat shock protein gene promoters assayed in Drosophila cells.

Hybrid genes containing mRNA encoding sequences for herpes virus thymidine kinase (tk), chloramphenicol acetyltransferase (CAT), or Drosophila alcohol dehydrogenase (Adh), ligated to truncated Drosophila melanogaster heat-shock protein 70 (hsp 70) gene promoters or to synthetic sequences containing one or several copies of a previously defined heat-shock consensus sequence, were transfected into cultured Drosophila line S3 cells. Each construction was then assayed for gene expression at 25 degrees C and 37 degrees C, using a CAT enzyme assay, slot blot hybridization, or S1 nuclease protection analysis. In the Drosophila cell transient expression assay system, we found that deletions extending beyond position -97, or synthetic constructions containing a single heat shock consensus sequence, were not induced by high-temperature shock. In constructions containing deletions extending to position -186, -130, or -97, in the hsp 70 promoter, and in synthetic constructions containing tandemly spaced heat-shock consensus sequences mRNA transcription was greatly induced by high temperature.

Animals↗

PubMed1986

Dimethylthiourea decreases acute lung edema in phorbol myristate acetate-treated rabbits.

Treatment with dimethylthiourea (DMTU), a potent O2 metabolite scavenger, prevented neutrophil-mediated acute edema in lungs of rabbits given phorbol myristate acetate (PMA) and in isolated rabbit lungs perfused with neutrophils and PMA. DMTU-treated rabbits given PMA did not increase their lung weight-to-total body weight ratios (5.0 +/- 0.3) or lung lavage albumin concentrations (14 +/- 4.6 mg/dl) in comparison to untreated rabbits given PMA (6.6 +/- 0.5 and 60 +/- 10 mg/dl, respectively). Similarly, DMTU-treated isolated rabbit lungs perfused with neutrophils and PMA did not gain weight (0 g) or increase their lavage albumin concentrations (82 +/- 17 mg/dl) in comparison to untreated lungs perfused with neutrophils and PMA (71 +/- 3.1 g and 1,299 +/- 47 mg/dl, respectively). DMTU did not appear to decrease edema by preventing increases in pulmonary arterial pressures (PAP). First, treatment with DMTU did not decrease initial PAP increases in rabbits given PMA. Second, even though addition of DMTU attenuated PAP increases in isolated lungs perfused with neutrophils and PMA, DMTU-treated isolated lungs did not develop acute edema when subjected to mechanical increases in venous outflow pressures. The mechanism by which DMTU decreases lung edema is unclear but may involve scavenging of toxic O2 metabolites, since DMTU also decreased hydrogen peroxide (H2O2) and hydroxyl radical (OH) concentrations in in vitro mixtures containing neutrophils and PMA.

Acute Disease↗

PubMed1986

O2 metabolites and neutrophil elastase synergistically cause edematous injury in isolated rat lungs.

Addition of glucose oxidase (GO) increased H2O2 concentrations and decreased antielastolytic activities of beta-D-glucose containing perfusates of isolated rat lungs. Pretreatment with GO also caused acute edematous injury (increased lung weight gains, increased recovery of Ficoll in lung lavages, and increased pulmonary arterial pressures) in isolated lungs perfused with purified human neutrophil elastase (NE). Acute edematous injury in isolated lungs pretreated with GO and then NE exceeded levels found in lungs following addition of GO or NE alone or NE before GO. Simultaneous addition of catalase (an H2O2 scavenger) or methoxy-succinyl-L-alanyl-L-alanyl-prolyl-L-valine-chloromethyl ketone (an NE inhibitor, but not aminotriazole-inactivated catalase, N-tosyl-L-phenyl-alanine chloromethyl ketone (a chymotrypsin inhibitor) or N-alpha-p-tosyl-L-lysine chloromethyl ketone (a trypsin inhibitor), prevented acute edematous injury in isolated lungs perfused with both GO and NE. This observation indicated that injury was dependent on both H2O2 and NE, especially since the relative inactivating specificities of the inhibitors for H2O2 or NE, respectively, were confirmed under similar conditions in vitro. The synergistic nature of the interaction between H2O2 and NE-mediated injury was further clarified when GO- and NE-induced lung injury was prevented by addition of an oxidant-resistant NE inhibitor (Eglin-C), but not an oxidant-sensitive NE inhibitor (human alpha 1-protease inhibitor, alpha 1PI). Moreover, treatment with H2O2 also decreased the ability of alpha 1PI but not Eglin-C to decrease NE activity in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Natural mycobacteriostatic activity in human monocyte-derived adherent cells.

The effects of human monocyte maturity on the replication of virulent Mycobacterium tuberculosis were examined. Mycobacteria grew readily in freshly isolated, adherent peripheral blood monocytes and in monocyte-derived macrophages obtained after 7 days in culture, as measured by counts of acid-fast bacilli and colony-forming units. Monocytes cultured for only 3 days before infection, however, were less permissive for the mycobacteria than either uncultured or 7-day cells. The association between the low permissiveness of 3-day cells and superoxide production was examined. Mycobacteria induced only a slight increase in superoxide production during the first 60 min of infection in uncultured and in 3-day cells, and no increase in cells cultured for 7 days before infection. Freshly isolated adherent cells produced small amounts of superoxide in response to phorbol myristate acetate (PMA) stimulation, but PMA-induced superoxide production increased steadily for 7 days. Mycobacteria had no effect on superoxide production by PMA-stimulated adherent cells. These results suggest that the suppressive activity of the 3-day cells is not associated with the production of increased amounts of reactive oxygen species.

Cell Survival↗

PubMed1986

Erythrocytes from cigarette smokers contain more glutathione and catalase and protect endothelial cells from hydrogen peroxide better than do erythrocytes from nonsmokers.

Recent observations regarding the ability of intracellular erythrocyte (RBC) antioxidants to decrease O2 metabolite-mediated injury to lung tissues has prompted interest in the RBC antioxidants of patients with lung disease. We found that RBC from 14 healthy, age- and gender-matched cigarette smokers contained more (p less than 0.05) glutathione (6.3 +/- 0.4 microM/g Hgb versus 5.0 +/- 0.3 microM/g Hgb) and catalase (249,533 +/- 8,307 units/g Hgb versus 222,617 +/- 7,180 units/g Hgb) than did RBC from nonsmokers. In contrast, RBC from cigarette smokers and nonsmokers contained the same activities of glutathione peroxidase (21.4 +/- 1.2 units/g Hgb versus 20.4 +/- 5.5 units/g Hgb). RBC from cigarette smokers also protected bovine pulmonary artery endothelial cells in culture from hydrogen peroxide (H2O2) better (p less than 0.005) than did RBC from nonsmokers (52.1 +/- 6.1% protection versus 31.9 +/- 5.7% protection). The results suggest that alterations in RBC antioxidants may reflect exposure and/or affect susceptibility to oxidant-induced injury.

Animals↗

PubMed1985

Transcript length heterogeneity at the small heat shock protein genes of Drosophila.

Expression of the small heat shock protein (hsp) genes can be induced in cultured Drosophila cells by high temperature shock and by exposure to physiological doses of the insect molting hormone ecdysterone. Northern blot analysis was performed in order to compare the size of small hsp transcripts synthesized in response to these two stimuli. Transcripts from several other genes were also examined. Two types of length heterogeneity were observed for the small hsp gene transcripts. One involved the synthesis of what are designated as long form transcripts during heat shock; small hsp messenger RNAs extended at the 3' end by some 1.5 X 10(3) base-pairs. The second type of size heterogeneity observed is based on differences in the length of the poly(A) tail. The results of S1 nuclease protection analysis provided evidence that different initiation sites are not used for hsp 22 mRNA transcription in response to the two stimuli.

Animals↗

PubMed1985

Expression of Drosophila hsp 70-CAT hybrid gene in Aedes cells induced by heat shock.

DNA-mediated transfer of a Drosophila hsp 70-CAT hybrid gene into Drosophila S3 cells leads to the appearance of heat shock (37 degrees C)-inducible chloramphenicol acetyltransferase (CAT) activity. When this hybrid gene construction was transfected into cultured Aedes, Plodia, or Manduca cells, only trace levels of heat-inducible CAT activity were observed. Induction could be somewhat improved by using Schneider's Drosophila medium for transfection. In the case of Aedes cells, levels of CAT induction comparable to that seen using Drosophila cells could be achieved by raising the heat-shock temperature to 41 degrees C, a treatment which is lethal to Drosophila.

Acetyltransferases↗