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PubMed1989

Embryonic expression pattern of a family of Drosophila proteins that interact with a central nervous system regulatory element.

The protein Elf-1 interacts with a cis-acting element that is required specifically for the neuronal expression of the Drosophila dopa decarboxylase gene Ddc. Using protein purified from Drosophila embryos, we raised Elf-1-specific monoclonal antibodies. The expression of Elf-1 during embryogenesis is restricted to nuclei of tissues derived from ectoderm, predominantly the central nervous system (CNS) and the epidermis. Within the CNS, Elf-1 is present in only a small fraction of nuclei, and the pattern of expressing nuclei changes dramatically during development. Elf-1 and Ddc are coexpressed in primary cultures of neural cells. However, we do not detect Elf-1 in Ddc-expressing neurons in vivo, leading to the suggestion that Elf-1 activity is required in vivo for initiation of Ddc expression but not for its maintenance. The antibodies also were used to isolate cDNA clones encoding Elf-1. Alternate forms of Elf-1 mRNA result in at least three protein isoforms.

Amino Acid Sequence↗
PubMed1991

Augmentation of functional prostaglandin E levels on the respiratory epithelial surface by aerosol administration of prostaglandin E.

Prostaglandin E (PGE), a cyclooxygenase metabolite normally present in high concentrations in respiratory epithelial lining fluid (ELF), is capable of suppressing mesenchymal cell proliferation mediated by polypeptide-derived growth factors. Although PGE is normally abundant in respiratory ELF, PGE levels in ELF of individuals with idiopathic pulmonary fibrosis (IPF), a fibrotic lung disorder characterized by intraalveolar mesenchymal cell accumulation and fibrosis, were found to be 50% lower than normal (p less than 0.01): that is, a relative PGE "deficiency" in ELF may enhance intraalveolar mesenchymal cell proliferation in IPF. With this background, it is rational to consider augmenting PGE levels in ELF as a future therapy for IPF. Since systemic administration of PGE is associated with significant adverse effects, in vitro and experimental animal studies were carried out to evaluate whether aerosol PGE administration could augment ELF PGE levels. Greater than 50% of a solution of PGE1 could be placed in droplets less than 3 microns mass median aerodynamic diameter without loss of function. Aerosolization of PGE1 to sheep (n = 14) resulted in a marked augmentation of ELF PGE1 levels (preaerosol 20 +/- 7 nM, 30 min postaerosol 1,150 +/- 210 nM; p less than 0.0 to 0.1). ELF PGE1 levels remained elevated for up to 2 h (p less than 0.05 compared with baseline) and returned to baseline by 3 h (p greater than 0.2). Lung interstitial fluid (lymph) PGE1 levels increased slightly, but to levels far less than ELF levels (preaerosol 7 +/- 1 nM, 30 min postaerosol 13 +/- 2 nM; p less than 0.01), and plasma PGE1 levels did not change (p greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1995

[Biological effects of electromagnetic fields].

Since several epidemiological studies have indicated an elevated risk for certain types of cancer in both living and working environments where exposure to an extremely low-frequency electromagnetic field (ELF) occurs, public concern about ELF has been increasing because it is impossible to imagine life today without electricity. We reviewed studies on biological effects of ELF with respect to their cytological and biochemical effects, including mutagenicity, clastogenicity and carcinogenicity. The studies can be summarized as follow: 1) There is evidence that outer surface of the cell membrane is the primary locus for ELF-induced cellular alterations. 2) ELF modulate the proliferation of normal as well as transformed cells in vivo and in vitro. The magnitude of the proliferative effects depends on ELF intensity, exposure duration and other cellular factors. 3) No studies clearly demonstrate deleterious effects of ELF exposure on mammalian reproduction and development, but several suggest such effects. 4) Reported evidence does not demonstrate that the ELF acts as a cancer initiator. However, it might act as a promoter or affect tumor progression. Further observations and epidemiological studies of ELF must be accompanied by laboratory experiments to evaluate biological and health effects.

Animals↗
PubMed1993

Aerosolization of superoxide dismutase. Augmentation of respiratory epithelial lining fluid antioxidant screen by aerosolization of recombinant human Cu++/Zn++ superoxide dismutase.

Various human pulmonary diseases are characterized by an increased oxidant burden on the respiratory epithelial surface. As a step toward developing a therapy to augment the antioxidant defenses of respiratory epithelial lining fluid (ELF) of the human lung, we have evaluated the feasibility of aerosolizing a human protein antioxidant to the respiratory epithelial surface of an experimental animal sufficiently large to permit repetitive sampling of ELF. To accomplish this, recombinant human Cu++/Zn++ superoxide dismutase (rSOD) was aerosolized to sheep, and the levels of human superoxide dismutase (SOD) and antisuperoxide anion (O2.-) capacity were quantified in ELF over time. In vitro aerosolization did not alter the specific activity of rSOD (p > 0.5). In vivo aerosolization of rSOD (100 mg) to sheep (n = 7) resulted in peak amounts of human Cu++/Zn++ SOD in ELF of 3.1 +/- 0.6 mumol/L, with a parallel increase in the anti-O2.- capacity of ELF. For the duration of the study (5 h), levels of SOD and anti-O2.- in ELF remained elevated, with a value 50 percent of the peak at 5 h. Aerosolization of phosphate-buffered saline (n = 5) had no effect on SOD or anti-O2.- levels in ELF. In animals receiving rSOD, there was no change in the specific activity of SOD recovered in ELF compared to the starting material (p > 0.4). We conclude that rSOD can be delivered by aerosol to the ELF of a large animal with preservation of specific activity and that a substantial increase in both the amount of SOD and the anti-O2.- capacity can be achieved for a period of time applicable to human therapy, supporting the rationale for evaluation of rSOD aerosol as an antioxidant in human pulmonary disease.

Aerosols↗
PubMed2005

Effect of extremely low frequency of electromagnetic fields on cell proliferation, antioxidative enzyme activities and lipid peroxidation in 3T3-L1 preadipocytes--an in vitro study.

The exposure to extremely low frequency electromagnetic field (ELF-MF, frequencies less than 200-300 Hz) can alter the transcription and translation of genes, influence the cell proliferation rate and affect enzyme activities. Moreover, the hypothesis that ELF-MF increases free oxygen metabolites generation has been proposed. Since recent in vivo studies suggest that electric and magnetic fields are able to affect adipose cells metabolism. The aim of the study was to examine the effects of ELF-MF (frequency of basic impulse 180-195 Hz, induction 120 microT) on cell proliferation, antioxidative enzyme activities and malondialdehyde (MDA) concentration in 3T3-L1 preadipocyte cell culture. We found that ELF-MF application lasting 36 minutes daily failed to influence cell count after 24h and 48 h of incubation. After 24 h, in the ELF-MF treated group, manganese- and copper-zinc-containing superoxide dismutase (MnSOD and Cu/ZnSOD) isoenzymes media activities were decreased, catalase activity was increased, whereas there were no significant differences in glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-Rd) activities in comparison to the control. After 48 h of incubation, all enzyme activities were reduced, except for GSSG-Rd, in which no changes were noticed. MDA concentration at 24 h after incubation with the exposure to ELF-MF was significantly higher in comparison to the control, without ELF-MF. After 48 h of incubation, MDA levels were significantly lower in both groups with no differences between the groups without and with ELF-MF. We conclude that ELF-MF influences antioxidative enzyme activities and increases lipid peroxidation in 3T3-L1 preadipocyte cultures.

3T3-L1 Cells↗
PubMed1993

Gene-specific modulation of RNA synthesis and degradation by extremely low frequency electromagnetic fields.

Pulse-labeling studies from our laboratory and others have shown that extremely low frequency (ELF) electromagnetic fields can produce a transient increase in gene transcription. In this study, the synthesis, degradation and processing, and steady state levels of specific RNA species during exposure to ELF radiation were determined in human leukemia HL-60 cells. The overall steady state RNA levels, assessed by continuous and equilibrium labeling with 3H-uridine, were not affected by ELF exposure. Northern blot analysis using probes specific for c-myc, beta-actin, and 45S ribosomal RNA gene products revealed that ELF did not alter the steady state levels of these RNAs. Examination of gene-specific transcription by a novel nuclease protection assay revealed that while ELF did not substantially alter the transcription rates for c-myc and beta-actin, transcription of the 45S ribosomal RNA gene was increased by 40-50%. To explain the observed increase in the synthesis of 45S ribosomal RNA without an associated increase in its steady state level, the degradation and processing of the ribosomal gene transcript in the presence and absence of an ELF field were followed by pulse-chase 3H-uridine labeling. This revealed that ELF radiation accelerated both the processing and degradation of the ribosomal RNA transcript. During ELF exposure, the half-life of the 45S ribosomal RNA was decreased from 115 min. to 85 min. These results show that ELF can selectively affect RNA levels by modulating either the transcription rate and/or RNA post-transcriptional processing and turnover.

Actins↗
PubMed1996

Translational regulation of vascular permeability factor by eukaryotic initiation factor 4E: implications for tumor angiogenesis.

Studies aimed at elucidating the function of the protein synthesis factor eukaryotic initiation factor 4E (elF-4E) have demonstrated that overexpression of this protein results in marked cell phenotypic and proliferative changes, including neoplastic transformation of cells. These data suggest that elF-4E may somehow participate in the development and progression of tumors in vivo. In order to determine how elF-4E exerts its transforming effects, we examined vascular permeability factor (VPF) levels in cells transfected with an elF-4E vector. Cells overexpressing elF-4E showed an increase in intracellular, and an average 130-fold increase in secreted VPF protein levels (CHO 0.13+/-0.12 ng/ml; CHO-4E 20.5+/-12.5 ng/ml) over control cells. HUVEC growth induction revealed these VPF levels to be biologically active. Northern analysis revealed no difference in VPF transcript between the 2 cell lines. Polysome analysis showed that the VPF message in elF-4E-transfected cells was associated with the heavy polysomal regions, whereas the VPF message was associated with light polysomes in control cells. These data strongly suggest that enhanced VPF expression is achieved through translational regulation rather than transcriptional regulation in cells overexpressing elF-4E. This indicates that elF-4E-induced VPF expression may be an important factor in some forms of tumor angiogenesis and development.

Animals↗
PubMed1997

Soluble HLA class I in epithelial lining fluid of lung transplants: associations with graft outcome.

We hypothesized that the small amounts of donor HLA-A and HLA-B proteins detected in the serum during organ allograft rejection are indicative of higher local releases within the graft itself. We determined the concentrations of total HLA class I (HLA-I) and, in selected cases, specific donor and host HLA-A and HLA-B proteins, in the epithelial lining fluid (ELF) sampled by bronchoalveolar lavage (BAL) of lung transplant recipients (n = 37) and of normal controls (n = 25). We found that 1) HLA-I proteins were enriched in the lung ELF relative to other proteins; 2) the concentration of HLA-I in the ELF of well-functioning transplants was similar to that in normal lungs; 3) HLA-I proteins and total proteins were elevated in the ELF of patients who developed chronic rejection or refractory acute rejection; 4) the concentration of HLA-I was correlated with the percentage of neutrophils but not with the percentage of lymphocytes in the ELF of transplanted lungs; and 5) only the percentage of lymphocytes was elevated in the ELF of transplant patients with active CMV infections. Total HLA-I from the ELF was found to contain a mixture of both donor- and recipient-type HLA-A and HLA-B proteins and the donor-type HLA-A2 was found to be highly enriched in the ELF relative to serum.

Acute Disease↗
PubMed1999

Impact of extremely low frequency electromagnetic fields on CD4 expression in peripheral blood mononuclear cells.

There is increasing evidence suggesting that extremely low frequency electromagnetic fields (ELF-EMF) may influence several cell functions. Here the effects of ELF-EMF were studied on the expression of CD4+ cell surface receptors of human peripheral blood mononuclear cells (PBMC) using fluorescence-activated cell sorter (FACScan). The expression of CD4+ in ELF-EMF exposed (24, 48 and 72 h) and not exposed PBMC were not statistically significant. In addition, a flow cytometric analysis was determined by using a fluorescent labeled antibody, at 24 and 72 h incubations. The amount of bound antibody was distributed with a slight difference in the ELF-EMF-exposed PBMC compared to the not exposed cells. Moreover, DNA CD4+ expression in PBMC strongly increased in exposed cells, resting and activated with Phytohaemaglutinin (PHA). When polymerase chain reaction was performed on CD4+ mRNA of PBMC an increase of CD4+ mRNA expression was found after the resting cells were exposed to ELF-EMF at 24 h compared to not exposed cells, while at 48 and 72 h no difference was found. In the cell cycle progression analysis, the PBMC exposed to ELF-EMF presented a significant increase of percentage expression of cell cycle progression in the S phase compared to not exposed cells; while in G1 and G2 phases, there were no differences. Our results provide new evidence that ELF-EMF can affect CD4+ expression in PBMC and describe an additional biological activity for ELF-EMF affecting CD4+ transcription and translation protein and the increase of the percentage expression of the cell cycle progression of the S phase.

Blotting, Western↗
PubMed2006

Critical interactions between TGF-beta signaling/ELF, and E-cadherin/beta-catenin mediated tumor suppression.

Inactivation of the transforming growth factor-beta (TGF-beta) pathway occurs often in malignancies of the gastrointestinal (GI) system. However, only a fraction of sporadic GI tumors exhibit inactivating mutations in early stages of cancer formation, suggesting that other mechanisms play a critical role in the inactivation of this pathway. Here, we show a wide range of GI tumors, including those of the stomach, liver and colon in elf+/- and elf+/- / Smad4+/- mutant mice. We found that embryonic liver fodrin (ELF), a beta-Spectrin originally identified in endodermal stem/progenitor cells committed to foregut lineage, possesses potent antioncogenic activity and is frequently inactivated in GI cancers. Specifically, E-cadherin accumulation at cell-cell contacts and E-cadherin-beta-catenin-dependent epithelial cell-cell adhesion is disrupted in elf+/- / Smad4+/- mutant gastric epithelial cells, and could be rescued by ectopic expression of full-length elf, but not Smad3 or Smad4. Subcellular fractionation revealed that E-cadherin is expressed mainly at the cell membrane after TGF-beta stimulation. In contrast, elf+/- / Smad4+/- mutant tissues showed abnormal distribution of E-cadherin that could be rescued by overexpression of ELF but not Smad3 or Smad4. Our results identify a group of common lethal malignancies in which inactivation of TGF-beta signaling, which is essential for tumor suppression, is disrupted by inactivation of the ELF adaptor protein.

Animals↗
PubMed1998

Concentration of enrofloxacin and its active metabolite in alveolar macrophages and pulmonary epithelial lining fluid of dogs.

The purpose of this study was to determine the concentration of enrofloxacin and its active metabolite, ciprofloxacin, in alveolar macrophages (AM) and epithelial lining fluid (ELF) of the lungs in comparison to plasma concentrations in healthy dogs. Eleven dogs were given a single oral dose (5 mg/kg) of enrofloxacin. Four hours later, plasma and bronchoalveolar lavage (BAL) fluid were collected. Cells were separated from the BAL fluid and lysed for determination of drug concentrations within AM. Supernatant was used to determine concentrations of drugs in ELF. Drug assays were performed by high-performance liquid chromatography. The concentration of enrofloxacin (mean +/- SD) was 0.33 +/- 0.14 microgram/mL in plasma, 3.34 +/- 2.4 micrograms/mL in AM and 4.79 +/- 5.0 micrograms/mL in ELF. The concentration of ciprofloxacin was 0.42 +/- 0.26 microgram/mL in plasma, 1.15 +/- 1.03 micrograms/mL in AM and 0.26 +/- 0.26 microgram/mL in ELF. Mean concentrations of both drugs in AM were greater than in plasma (AM to plasma ratio, 10.3 for enrofloxacin and 4.7 for ciprofloxacin). Mean concentrations of enrofloxacin, but not ciprofloxacin, in ELF were greater than in plasma (ELF to plasma ratio, 13.5 for enrofloxacin and 0.52 for ciprofloxacin). Enrofloxacin concentrations in AM and ELF largely exceeded the MICs of the major bacterial pathogens and surpassed by about two times the breakpoint MIC of that drug, and ciprofloxacin concentrations in AM surpassed the MIC of many susceptible organisms. These results suggest that sufficient antimicrobial activity is present in AM and ELF of dogs following oral administration of enrofloxacin to be effective in the treatment of lower respiratory tract infections involving susceptible organisms.

Animals↗
PubMed2001

Enzyme activities, protein content and cellular variables in the pulmonary epithelial lining fluid in selected healthy pigs.

Reference values of cellular and non-cellular components in the bronchoalveolar lavage fluid (BALF) were established from the BALF specimens obtained from 52 healthy pigs. Using urea as an endogenous marker of dilution, the reference values in the epithelial lining fluid (ELF) were calculated: total cell count 2.71 x 10(9) - 56.49 x 10(9) litre(-1) ELF, alveolar macrophages 2.02 x 10(9) - 49.91 x 10(9) litre(-1) ELF, lymphocytes 0.10 x 10(9) - 4.74 x 10(9) litre(-1) ELF, polymorphonuclear neutrophils 0.01 x 10(9) - 3.48 x 10(9) litre(-1) ELF, protein 0.10 - 13.13 g litre(-1) ELF, lactate dehydrogenase 127-1843 Units litre(-1) ELF, and alkaline phosphatase 86-994 Units litre(-1) ELF. The problems of quantification of BALF components are discussed and a standardized lavage protocol in swine is described, which is essential for the interpretation of diagnostic findings and for the comparison of different BALF specimens.

Animals↗
PubMed1990

Augmentation of glutathione in the fluid lining the epithelium of the lower respiratory tract by directly administering glutathione aerosol.

Glutathione (GSH), a cysteine-containing tripeptide, functions as an antioxidant, provides cells with cysteine, and is required for optimal function of the immune system. Because the epithelial-lining fluid (ELF) of the lower respiratory tract normally contains high GSH levels and lung ELF GSH deficiency states can exist, we evaluated the feasibility of augmenting lung ELF GSH levels by (i) administering GSH to sheep i.v. and by direct aerosolization and then (ii) measuring the GSH levels in lung ELF, lung lymph, venous plasma, and urine. When GSH (600 mg) was administered i.v. (n = 11), GSH levels in venous plasma, lung lymph, and ELF rose, but only transiently, suggesting the i.v. route would not deliver adequate GSH to the alveolar epithelial surface. For directly administering GSH to the lung by the aerosol route, in vitro studies were first conducted to show that greater than 50% of a GSH solution could be converted to droplets less than 3 microns in aerodynamic diameter without oxidizing the GSH. To target functional GSH to the lower respiratory tract, an aerosolized solution of GSH (600 mg) was administered to sheep (n = 12). Significantly, the GSH level in ELF increased 7-fold at 30 min (preaerosol, 45.7 +/- 10 microM; 30-min postaerosol, 337 +/- 64 microM; P less than 0.001). The ELF GSH levels remained above baseline at 1 hr (P less than 0.01), returning toward baseline over a 2-hr period. In contrast, GSH levels in lung lymph, venous plasma, and urine were not significantly increased during the period--i.e., aerosol therapy selectively augmented the GSH levels only at the lung epithelial surface. Thus, functional GSH can be delivered by aerosol to directly augment the ELF GSH levels of the lower respiratory tract. Such an approach may prove useful in treating a variety of lung disorders.

Aerosols↗
PubMed2001

Review of safety in endoscopic laser foraminoplasty for the management of back pain.

OBJECTIVE: The purpose of this study was to analyze the incidence and gravity of reported complications that arise in spinal surgery and assess the comparative safety, or otherwise, of endoscopic laser foraminoplasty (ELF). BACKGROUND DATA: Chemonucleolysis, decompression, discectomy, and fusion have long been cited as treatments for chronic low back pain. Over recent years newer, less invasive surgical techniques have become available, one such being ELF. Although minimally invasive, the beneficial outcome must be interpreted in relation to concerns regarding the safety of the procedure and its risks relative to those of other forms of spinal surgery. The Spinal Foundation, Rochdale has performed 958 ELFs and has collated a comprehensive database of the results of all these operations. These prospective records provided the basis for a comparison of the safety of ELF to that reported with other spinal surgical techniques. METHODS: A total of 958 procedures have been performed on 716 patients. Complications that arose during the operation and the postoperative phase of 6 weeks following the procedure were elicited from patient records. These data were correlated and compared to a meta-analysis of randomized controlled clinical trial data of complications arising during and after conventional spinal surgery. The SPSS (statistical package for social sciences) and CIA (confidence interval analysis) statistical packages were used to draw conclusions regarding the safety of ELF. RESULTS: The cohort integrity of operation and outpatient review records at 6 weeks after surgery was 100%. In 958 ELFs performed, 24 complications occurred in 23 patients. There were 9 cases of discitis (1 infective, 8 aseptic) (0.9%), 1 dural tear (0.1%), 1 deep wound infection (0.1%), 2 patients suffered a foot drop (1 transient) (0.2%), 1 myocardial infarction (0.1%), 1 erectile dysfunction (0.1%), and 1 patient who developed panic attacks post-operatively (0.1%). This amounts to an overall surgical complication rate of 1.6%. Magnetic resonance imaging (MRI) follow up of clinically symptomatic patients highlighted 8 residual disc herniations (0.8%). Meta-analysis of randomized controlled trials of conventional spinal surgery for adult onset degenerative disc disease and/or sciatic pain reported overall complication rates for fusion (11.8%), decompression (7.6%), discectomy (6.0%), and chemonucleolysis (9.6%). CONCLUSIONS: The complication rate of ELF is shown to be significantly lower than that reported following conventional spinal surgery (p < 0.01). From these results, we conclude that ELF as a treatment for chronic low back pain and sciatica presents less risk to a patient than conventional methods of spinal surgery.

Chronic Disease↗
PubMed1987

Protein synthesis in Drosophila melanogaster embryos. Purification and characterization of polypeptide chain-initiation factor 2.

Eukaryotic initiation factor 2 (elF-2) was purified from the high-salt wash fraction of Drosophila melanogaster embryos. This factor, with a molecular mass of about 90 kDa, consists of two subunits of 47 kDa and 39 kDa on dodecylsulfate/polyacrylamide gel electrophoresis. The 39-kDa subunit is phosphorylated by the hemin-controlled inhibitor of rabbit reticulocytes in a terminal fragment which can be cleaved by mild treatment with trypsin. Drosophila elF-2 is not a substrate for protein kinases capable of phosphorylating the beta subunit of elF-2 from rabbit reticulocytes. It is also shown that Drosophila elF-2 can form a ternary complex with GTP and Met-tRNAi, which can be efficiently transferred to 40S ribosomes in the presence of AUG and Mg2+. This factor is able to form a binary complex with GDP. Furthermore, purified elF-2 contains about 0.3 mol bound GDP/mol suggesting a high affinity of the factor for this nucleotide. Data supporting the notion that this affinity is increased in the presence of Mg2+, which impairs the GDP/GTP exchange on elF-2, are presented. The properties of Drosophila elF-2 suggest that this factor may be susceptible to regulation by a mechanism like that operating on rabbit reticulocyte elF-2.

Animals↗
PubMed1999

Phosphate stress in cultures and field populations of the dinoflagellate prorocentrum minimum detected by a single-cell alkaline phosphatase assay

Alkaline phosphatase activity is a common marker of phosphate stress in many phytoplankton, but it has been difficult to attribute alkaline phosphatase activity to specific organisms or groups of phytoplankton in the field with traditional biochemical procedures. A new alkaline phosphatase substrate, ELF-97 (enzyme-labeled fluorescence), shows promise in this regard. When a phosphate group is cleaved from the ELF-97 reagent, the remaining molecule precipitates near the site of enzyme activity, thus fluorescently tagging cells with alkaline phosphatase activity. We characterized ELF-97 labeling in axenic cultures of a common dinoflagellate, Prorocentrum minimum, in order to understand ELF-97 labeling dynamics when phosphate nutrition varies. Enzyme activity, as detected by ELF-97 labeling, appears to be induced in late-log- or early-stationary-phase cultures if cells are grown in low-phosphate media and is lost when phosphate-stressed cells are refed with phosphate. ELF-97 appears to label an inducible intracellular alkaline phosphatase in P. minimum based on confocal microscopy studies. This may limit the use of this reagent to organisms that lack high levels of constitutive intracellular phosphatases. After laboratory cultures were characterized, ELF-97 was used to assay field populations of P. minimum in Narragansett Bay during two 1-week periods, and 12 to 100% of the P. minimum cells were labeled. The level of cell labeling was reduced by 3 days of incubation with added inorganic phosphate. Our results indicate that ELF-97 is an excellent new tool for monitoring phytoplankton phosphate stress in the environment when the data are supported by appropriate laboratory studies.

Journal Article↗
PubMed1997

Gelatinases in epithelial lining fluid of patients with adult respiratory distress syndrome.

Gelatinases A and B are matrix metalloproteinases secreted as inactive pro forms and are capable of degrading basement membrane components after activation in the extracellular environment. To determine whether the presence of gelatinases A (noninflammatory cells) and B (inflammatory cells) in epithelial lining fluid (ELF) is associated with the adult respiratory distress syndrome (ARDS), we studied 28 patients divided into four groups based on the presence of ARDS and/or multiple organ failure (MOF). Gelatinase activities were quantified in ELF using zymography. ARDS patients had larger ELF volumes than non-ARDS patients: 9.2 +/- 8.5 ml/100 ml recovered lavage fluid (n = 18) vs. 1.9 +/- 1.7 ml/100 ml (n = 11), respectively (P < 0.001). The presence of activated gelatinase A in ELF was a sensitive (16 out of 18 ARDS patients, 89%) and specific (0 out of 11 non-ARDS patients with or without MOF) marker for ARDS. Activated gelatinase (A + B) activities per microliter ELF were correlated with albumin concentrations in ELF (P < 0.01), and activated gelatinase activities in ELF were correlated with the volume of ELF (P < 0.0005). This could suggest an involvement of these gelatinases in alveolar-capillary permeability increase.

Adult↗
PubMed1997

Changes in gamma-glutamyltransferase activity in rat lung tissue, BAL, and type II cells after hyperoxia.

The effect of hyperoxia on gamma-glutamyltransferase (gamma-GT), an important enzyme for the uptake of precursor molecules for intracellular synthesis of glutathione (GSH), has not been established. Our aim was to investigate the effects of prolonged subtoxic levels of hyperoxia on gamma-GT activity and GSH levels in lung tissue, epithelial lining fluid (ELF), and isolated rat type II cells immediately after their isolation and 48 h later when kept in culture in normoxia. Seventeen male Wistar rats were divided in three groups (n = 5-7) and were exposed to air or to 60 or 85% O2 for 7 days. Pulmonary gamma-GT activity increased in the 60 and 85% O2-exposed animals (1.6- and 3.2-fold, respectively), and tissue GSH levels increased only in the 60% O2 group (1.3-fold). In isolated type II cells from 60 and 85% O2-exposed animals, gamma-GT activity decreased by -70 and -88%, respectively, which was supported by cytochemical staining. Type II cell gamma-GT mRNA expression tended only to decrease after 85% O2. Type II cell gamma-GT activity strongly correlated with ELF gamma-GT (r = 0.60, P < 0.001), and ELF gamma-GT strongly correlated with ELF GSH (r = 0.75, P < 0.0001). When in culture, type II cell gamma-GT activity and GSH levels remained, respectively, 2.5- and 1.9-fold lower in the 60% O2-exposed group, but, in the 85% O2-exposed group, gamma-GT activity increased 2.1-fold, and GSH levels dropped to the levels of the control cells. Hyperoxia led to a concentration-dependent decrease in gamma-GT activity in rat type II cells, possibly by direct inactivation, but led to an increase in whole lung tissue gamma-GT. There seemed to be a negative feedback between intracellular GSH levels and type II cell gamma-GT activity. gamma-GT levels in the ELF were correlated with type II cell gamma-GT activity, but ELF gamma-GT did not seem to play an active role in the regulation of the ELF GSH pool. Hyperoxia decreased ELF GSH levels, possibly by increased degradation of GSH in the parenchymal lung tissue as a result of the increased gamma-GT activity.

Alkaline Phosphatase↗