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Biomedical subjects

A Ludwicka

Publications and source records attributed to A Ludwicka.

At least 19 recordsLinked to original sources
PubMed1997

Cytokine concentrations in bronchoalveolar lavage fluid of patients with systemic sclerosis.

OBJECTIVE: The pathophysiology of pulmonary fibrosis in patients with systemic sclerosis (SSc) is poorly understood, but a number of recent studies have demonstrated an inflammatory process involving the lower respiratory tract. The objective of the present study was to determine the concentrations of several cytokines in the bronchoalveolar lavage (BAL) fluid of patients with SSc and to assess whether the enhanced expression of certain cytokines is associated with the presence of alveolitis. METHODS: BAL was performed on patients with SSc (with or without alveolitis) and on normal control subjects. Lyophilized BAL fluid samples were assayed by enzyme-linked immunosorbent assay for tumor necrosis factor alpha (TNF alpha), interleukin-1alpha (IL-1alpha), IL-4, IL-6, IL-8, macrophage inflammatory protein 1alpha (MIP-1alpha), and RANTES. RESULTS: There were significant differences between groups in the BAL fluid concentrations of TNF alpha (P = 0.0005, with levels in SSc patients with alveolitis higher than those in normal controls), IL-8 (P = 0.006, with levels in both SSc groups higher than those in normal controls), MIP-1alpha (P = 0.009, with levels in SSc patients with alveolitis higher than those in SSc patients without alveolitis and than those in normal controls), and RANTES (P = 0.03, with levels in SSc patients without alveolitis higher than those in normal controls). With the exception of RANTES, the highest levels were detected in SSc patients with alveolitis. CONCLUSION: Each of these cytokines, either alone or in combination, may play an important role in the pathogenesis of pulmonary fibrosis in SSc.

Adult↗
PubMed1997

Increased activity of the alpha 1(I) procollagen promoter in skin fibroblasts from patients with chronic eosinophilia-myalgia syndrome.

Eosinophilia-myalgia syndrome (EMS), a novel L-tryptophan-associated disease, which occurred as an epidemic in 1989, is characterized by diffuse fibrosis of the skin. The objective of these studies was to compare the in vitro expression of the gene encoding the human alpha 1(I) procollagen (COL1A1) in dermal fibroblasts derived from patients with long-standing EMS and from healthy controls. Early passage fibroblasts in culture were transiently transfected with a series of progressively 5' deleted human COL1A1 promoter-CAT reporter gene DNA constructs. Resultant CAT activity was assayed in the cytoplasmic extracts. Following transient transfection, COL1A1 promoter activity in 4/5 fibroblast cell lines derived from patients with EMS was two-to threefold greater than in matched normal fibroblasts. Deletion analysis indicated that CAT activity was highest, and displayed the greatest increase in EMS vs normal fibroblasts, with promoter constructs spanning 174 bp upstream from the COL1A1 transcription start site. The study shows increased CAT activity driven by a 174 bp fragment of COL1A1 in transiently transfected skin fibroblasts from patients with EMS even in the chronic stage of disease. These findings expand on previous observations indicating increased type I collagen gene expression in EMS fibroblasts, and suggest that fibrosis in L-tryptophan-induced EMS is associated with transcriptional activation of type I collagen gene expression, which persists even following cessation of L-tryptophan use.

Adult↗
PubMed1996

A contaminant of L-tryptophan enhances expression of dermal collagen in a murine model of eosinophilia myalgia syndrome.

The eosinophilia-myalgia syndrome was associated with the ingestion of L-tryptophan products containing a number of contaminants, one of which has been identified as 1,1'-ethylidene-bis-(L-tryptophan) (EBT), also known as peak E or peak 97. In earlier studies, we demonstrated that EBT induces inflammation and fibrosis in dermal and subcutaneous tissue of C57BL/6 mice. Others have shown EBT to be a potent stimulus for fibroblast activation and collagen synthesis in vitro, and dermal tissue from EMS patients reveals evidence of enhanced collagen gene expression. In the present study using Northern blot analysis and in situ hybridization, we demonstrate enhanced expression of genes for types I, III, and VI collagen in the dermis and subcutis of C57BL/6 mice treated with EBT for 3-21 days. Increased type I procollagen mRNA was noted on day 6 of EBT treatment and was followed by enhanced expression of type III and VI procollagen mRNA at day 21. L-Tryptophan, free of contaminants associated with the eosinophilia-myalgia syndrome epidemic, increased dermal collagen mRNA to a lesser extent than did EBT. Increased procollagen gene expression was accompanied by evidence of enhanced TGF-beta 1 expression in the dermis and subcutis. This animal model provides additional evidence for EBT as a causal agent of the eosinophilia-myalgia syndrome and should prove useful in the study of the pathogenesis of that syndrome.

Animals↗
PubMed1995

Elevated levels of platelet derived growth factor and transforming growth factor-beta 1 in bronchoalveolar lavage fluid from patients with scleroderma.

OBJECTIVE: Systemic sclerosis (scleroderma, SSc) frequently affects the lungs, and interstitial pulmonary fibrosis is one of its major complications. The pathophysiology of SSc lung disease s poorly understood, but recent studies document an inflammatory process resembling that of idiopathic pulmonary fibrosis with increased numbers of activated alveolar macrophages and granulocytes in bronchoalveolar lavage (BAL) fluid). We determined levels of 2 potentially important mediators of fibroproliferative repair in BAL fluid from patients with SSc. METHODS: Using Western blot and ELISA techniques we measured levels of platelet derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta in BAL fluid from patients with SSc and healthy controls. The mitogenic effect of these cytokines on SSc lung myofibroblasts was determined by [3H]thymidine incorporation. RESULTS: SSc BAL fluid contains significantly elevated levels of PDGF-AA and PDGF-BB. Where TGF-beta 1 was significantly elevated in SSc lavage fluid, the amount of TGF-beta 2 was significantly less than that observed in normal lavage fluid. Myofibroblasts cultured from SSc lavage fluid exhibited enhanced [3H]thymidine incorporation upon exposure to the growth factors present in SSc BAL fluid: PDGF and TGF-beta 1. SSc lung myofibroblasts pretreated with TGF-beta 1 exhibited an enhanced mitogenic effect upon stimulation by PDGF, due in part to the induction of the PDGF alpha receptor. CONCLUSION: Our studies support a role for PDGF and TGF-beta 1 in the pathogenesis of SSc lung disease.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Scleroderma bronchoalveolar lavage fluid contains thrombin, a mediator of human lung fibroblast proliferation via induction of platelet-derived growth factor alpha-receptor.

In addition to its procoagulant properties, the serine protease thrombin increases endothelial permeability, stimulates granulocyte adherence, and serves as a fibroblast mitogen. We demonstrate that thrombin is mitogenic for human lung fibroblasts in vitro. The mitogenic effect of thrombin is associated with an increase in the expression of the ligand PDGF-AA and up-regulation of PDGF alpha-receptor. Since scleroderma (systemic sclerosis; SSc) is characterized by widespread microvascular injury and is frequently complicated by pulmonary fibrosis, we sought to determine the level of thrombin activity in bronchoalveolar lavage (BAL) fluid from SSc patients and normal controls. We report a significantly higher level of thrombin activity in BAL fluid from SSc patients compared with normal controls (P < 0.001). Taken together, the high levels of thrombin in BAL fluid and its demonstrated mitogenicity for lung fibroblasts suggest an important role for thrombin in the pathogenesis of SSc and perhaps other fibrotic lung diseases.

Adult↗
PubMed1994

A murine model of the eosinophilia-myalgia syndrome induced by 1,1'-ethylidenebis (L-tryptophan).

The eosinophilia-myalgia syndrome (EMS) is a recently described disease that has been associated with the ingestion of L-tryptophan containing trace amounts of several impurities. The first such contaminant to be identified and linked epidemiologically to the EMS epidemic was 1,1'-ethylidenebis(L-tryptophan) (EBT), but its role in the etiology and pathogenesis of the syndrome has been controversial. We report the development of inflammation and fibrosis affecting the dermis and subcutis, including the fascia and perimyseal tissues, after the daily intraperitoneal administration of EBT to female C57BL/6 mice. Such changes are accompanied by increased numbers of mast cells, many of which appear to be degranulating. Plasma levels of quinolinic acid, a metabolic product of L-tryptophan via the kynurenine pathway, are reduced initially, and then become elevated when inflammation and fibrosis are more pronounced. The nature and location of the inflammatory cell infiltrate and fibrosis, as well as the presence of mast cells and alterations of L-tryptophan metabolism, are consistent with findings reported in patients with EMS. This murine model suggests that EBT may have been one of the mediators of EMS and should facilitate studies of the pathogenesis of EMS.

Animals↗
PubMed1992

Growth and characterization of fibroblasts obtained from bronchoalveolar lavage of patients with scleroderma.

We describe the detection and the growth of fibroblasts with human smooth muscle cell differentiation features from bronchoalveolar lavage (BAL) fluid of 53% of patients with scleroderma, but not from healthy controls. The binding of alpha-actin, vimentin and desmin antibodies by scleroderma lung fibroblasts exceeded that of normal adult lung fibroblasts, indicating that scleroderma lung fibroblasts express some markers of human smooth muscle cell differentiation (myofibroblasts), which may account for differences in biological behavior. A mesenchymal cell phenotype was documented by mRNA analysis, showing high expression of collagen type I and fibronectin in these cells. Fibronectin is also released in significantly higher amounts by scleroderma alveolar macrophages than by macrophages from healthy donors.

Actins↗
PubMed1991

[Nephrotoxicity of aminoglycosides. I: Preventive intraperitoneal calcium administration].

UNLABELLED: The effect was studied of intraperitoneal intake of calcium on gentamicin nephrotoxicity in the rats. Two groups of Wistar were studied: G--in the first group gentamicin was injected in single daily dose 100 mg/kg b.w. subcutaneously, GCa--in the second group gentamicin was given s.c. and calcium intraperitoneal in single daily dose 45 mg Ca++/kg b.w. Results were evaluated after 3, 7, and 10 days of gentamicin injections and after ten days of gentamicin removal, Mean creatinine level after ten days of gentamicin administration was in G group 4.52 +/- 0.77 mg%, GCa--1.87 +/- 0.21 mg%, p less than 0.02, mean urea 192. 62 +/- 21.88 mg%, 77.09 +/- 8.68 mg%, p less than 0.01, serum calcium 8.39 +/- 0.15 mg%, 9.96 +/- 0.21 mg%, p less than 0.001, gentamicin in the renal cortex 384.68 +/- 67.62 micrograms/g tissue, 327.38 +/- 81.89 micrograms/g tissue p less than 0.05. Urinary calcium excretion was higher in the GCa group than in the group of control rats. Statistical differences were significant after 3 and 7 days of gentamicin intake. Differences were found also in the light and electron microscopic examination. CONCLUSION: Intraperitoneal calcium loading significantly reduced the gentamicin nephrotoxicity in the rats and lowered gentamicin level in the renal cortex of the rats.

Animals↗
PubMed1991

[Nephrotoxicity of aminoglycosides. II. Preventive studies with oral administration of verapamil].

The effect was studied of oral verapamil administration in two different doses on gentamicin nephrotoxicity. Three groups of Wistar male rats were studied: 1) treated with gentamicin 100 mg/kg b.w. subcutaneously, 2) treated with gentamicin s.c. and verapamil 5 mg/100 ml given in drinking water, 3) treated with gentamicin s.c. and verapamil 20 mg/100 ml. The examinations were performed after 3, 7 and 10 days of gentamicin administration and after 10 days of gentamicin removal. Oral verapamil administration in these doses did not prevent the renal functional and histological damage after gentamicin administration. Renal cortex content of gentamicin was lower only after 3 days of gentamicin administration (statistically significantly) in the verapamil groups.

Administration, Oral↗
PubMed1991

[Nephrotoxicity of aminoglycosides. III. Preventive studies with subcutaneous administration of converting enzyme inhibitor, captopril].

The effect was studied of the converting enzyme inhibitor (captopril) on the gentamicin nephrotoxicity in rats. Captopril 25 mg/kg b.w. and gentamicin 100 mg/kg b.w. were injected subcutaneously in a single daily dose. Three groups of Wistar male rats were studied: 1) treated with gentamicin 3 and 7 days, 2) treated with gentamicin and captopril, 3) treated with captopril. The mean serum creatinine and urea levels and proteinuria in the second group were significantly higher than in the first one. Light and electron microscopy examinations demonstrated increased renal cortex damage in the second group. There were not differences between mean urea and creatinine levels in the third examined group and normal rats. Mechanism of gentamicin nephrotoxicity enhancement in the second group is unknown.

Animals↗
PubMed1990

Cryoprecipitate of intermediate purity produced in a closed thaw-siphon system from DDAVP stimulated blood donor plasma.

The effects of intravenous administration of DDAVP to blood donors and the use of DDAVP plasma for the production of cryoprecipitate in the closed thaw-siphon system were evaluated. DDAVP treatment produced on the average a 3.2-fold rise in plasma levels of factor VIII. Von Willebrand factor antigen increased to a lesser extent. Cryoprecipitate prepared from 220-280 ml aliquots of DDAVP stimulated donor plasma contained 472 +/- 210 units of factor VIII and 276 +/- 130 units of von Willebrand factor antigen. The average yield of factor VIII was 57% of that in the prefrozen plasma. The specific activity of factor VIII in cryoprecipitate was 0.77 +/- 0.44 U/mg protein, comparable to that for intermediate purity concentrates. Thus, by the use of DDAVP and the thaw-siphon technique it is possible to produce cryoprecipitate 4-7 times as potent as conventionally manufactured preparations.

Blood Donors↗
PubMed1985

Anticoagulant properties of extracellular slime substance produced by Staphylococcus epidermidis.

Slime produced by S. epidermidis strain KH 11 was extracted with phenol-saline. The saline phase was fractionated on a DEAE-Sepharose CL-6B column. The crude slime solution and its phenol-saline fraction were found to possess anticoagulant properties. They inhibited the coagulation of human plasma by thrombin, prolonged the activated partial thromboplastin time, but did not change the rate of plasma coagulation by reptilase. The anticoagulant effect of slime could be neutralized by rather high concentrations of protamine sulphate. In the presence of plasma, the staphylococcal slime also inhibited in a concentration dependent fashion the amidolytic activity of thrombin and factor Xa against synthetic chromogenic substrates. Both antithrombin III (AT III) and other plasma component(s), presumably heparin cofactor II, were required for the full expression of the slime effect. The anticoagulant action of slime was markedly less AT III dependent than that of heparin. The activity was resistant to heating (100 degrees C, 30 min). Slime and its fractions were stronger inhibitors of thrombin than of factor Xa. Fraction IV separated by DEAE-Sepharose chromatography and particularly rich in galactose and glucuronic acid had the highest inhibitory potency. It is conceivable that slime component(s) similar to glycosaminoglycans from other sources can carry the anticoagulant activity.

Anticoagulants↗
PubMed1984

Attachment of staphylococci to various synthetic polymers.

Attachment of staphylococci to different synthetic polymers used for medical purposes was studied in applying the bioluminescent technique. The number of attached bacterial cells was determined by measuring the light emission resulting from the reaction between firefly luciferase and ATP present in adhered staphylococcal cells. It was shown that staphylococci attach to synthetic polymers within a few minutes, although one hour incubation is required to reach a constant maximum value of attached cells. Ten different synthetic polymers and five Staphyloccocus epidermidis strains were investigated in our study. The relationship between surface properties of polymers and bacterial attachment was studied. Various physicochemical parameters of synthetic polymers and bacteria were determined (contact angle, surface tension). It was demonstrated that bacterial attachment decreases with decreasing contact angle and with increasing surface tension of synthetic materials. Modifications of surface charge and hydrophobicity of solid materials were also investigated. It could be proved that especially negatively charged and hydrophilic synthetic polymers show very decreased staphylococcal attachment.

Catheters, Indwelling↗
PubMed1984

Investigation on extracellular slime substance produced by Staphylococcus epidermidis.

The extracellular slime substance produced by Staphylococcus epidermidis was investigated. Slime production was assessed by bacterial agglutination in the presence of concanavalin A (Con A) or poly-L-lysine and by bacterial adherence to polyethylene. Media for slime production was optimized using these criteria. A phenol-saline extract of crude slime was separated into four fractions on a DEAE-sepharose column. Total protein and sugar content and the monosaccharide constituents were determined. Crude slime and the phenol-saline extract showed a strong precipitation reaction with Con A and poly-L-lysine (double diffusion). Fractions I and II containing mannose as the most abundant sugar reacted with Con A and two other mannose-specific lectins (Lens culinaris, Pisum sativum). This reaction could be inhibited by mannose. Fractions III and IV were precipitated by poly-L-lysine, probably due to a reaction with glucuronic acid which was only present in these fractions. Precoating of polyethylene with crude slime, phenol-saline extract and fractions III and IV resulted in a marked inhibition of attachment of staphylococcal cells. Production of the extracellular slime substance was completely inhibited by subinhibitory concentrations of the glycosylation inhibitor tunicamycin, whereas penicillin had no influence. Extracellular slime substance produced by S. epidermidis seems to be a complex of glycoconjugate character and plays an important role in the attachment to synthetic polymers. The production of slime by staphylococci can be easily determined using mannose specific lectins and poly-L-lysine.

Adhesiveness↗
PubMed1983

Microbial colonization of prosthetic devices. V. attachment of coagulase-negative staphylococci and "slime"-production on chemically pure synthetic polymers.

On 12 different, chemically pure polymers attachment and "slime"-production of the coagulase-negative staphylococcal strain KH 11 were studied. According to their behaviour the polymers investigated could be arranged into three groups: Group 1 with good attachment of staphylococci, but missing "slime"-production; group 2 with good attachment and moderate "slime"-production; group 3 with both properties strongly developed. According to the results presented, attachment of staphylococci and "slime"-production seem to be independent of the presence of organic additives in biomaterials.

Adhesiveness↗
PubMed1978

Characterization of group A streptococcal T-12 protein purified by ion-exchange column chromatography.

The aim of the present study was to describe the physicochemical characteristics of streptococcal T antigen. T protein isolated from Streptococcus pyogenes type 12 (R53/1077, Colindale) and purified by ion-exchange column chromatography resulted in a preparation that was homogeneous when tested electrophoretically (in two systems, in presence and in absence of sodium dodecyl sulfate) and by gel filtration on Sephadex G-100. The purified T antigen was resistant to enzymatic degradation by trypsin and pepsin. It formed a single precipitin line with standard T-12 antiserum and was not contaminated with group A carbohydrate and M protein. The molecular weight of protein T, determined by means of polyacrylamide gel electrophoresis and calculated from its amino acid composition, was about 39,000. The molecular weight of this protein, determined by means of high-speed sedimentation equilibrium, ranged between 80,000 and 120,000. Glutamic and asparatic acids, lysine, alanine, and leucine were the predominant amino acids.

Amino Acids↗