In situ revascularisation with silver-coated polyester prostheses and arterial homografts in patients with aortic graft infection--a prospective, comparative, single-centre study.

OBJECTIVE: The aim of our study was to evaluate the effectiveness of in situ revascularisation with the use of arterial homografts and silver-coated prostheses in the treatment of aortic graft infection. MATERIALS: A total of 77 consecutive patients (74 males, three females, mean age: 58 years), hospitalised between 2001 and 2008, were enrolled into the study. Patients were assigned to three groups: group 1 (n = 24)--fresh arterial homograft with subsequent immunosuppression, group 2 (n = 26)--fresh arterial homograft without immunosuppression and group 3 (n = 27)--silver-coated prosthesis. METHODS: The course of infection was assessed by scintigraphy with (99m)Technetium-labelled leucocytes, Duplex-Doppler ultrasound, angio-computed tomography (CT) and microbiological examination. RESULTS: The mean follow-up was 22.8 (±10.1) months. There was a significant decrease in leucocyte accumulation around the graft among all groups (group 1: p = 0.012, group 2: p = 0.006 and group 3: p = 0.021). The postoperative mortality rate in groups 1,2 and 3 was 8%, 23% and 11%, respectively. The postoperative morbidity was 35% in group 2, 16% in group 1 and 7% in group 3. CONCLUSION: Our study suggests that silver-coated prostheses can be as effective as arterial allografts in the treatment of infections of vascular prostheses.

Inhalations of 5-ALA in photodynamic diagnosis of bronchial cancer.

BACKGROUND: Photodynamic bronchoscopy (PDD) allows for early detection of bronchial cancer. Adverse effects and high costs, partly related to general application of photosensitisers, are important limitations of the method. The local application of a photosensitiser could help to minimize these problems. In this study the validity and safety of inhaled 5-ALA have been tested. METHODS: We examined 49 patients (age 59 +/- 11, cigarette consumption 36 +/- 17 pack-years) with present or past respiratory neoplasms and other with increased risk of bronchial cancer by photodynamic bronchoscopy (Storz-D-light) after inhaled 5-ALA. Biopsies were taken from the fluorescence-positive and negative foci (control). Symptoms and pre-/post-inhalation spirometry were analysed. RESULTS: The overall sensitivity was 82%, specificity 62%, positive predicted value (PPV) 45% and negative predictive value (NPV) 90%. Specificity decreased to 53% and PPV to 15% when visible tumours were excluded. PDD, when added to white light bronchoscopy increased sensitivity by 2.1% and NPV by 6%, but decreased specificity by 35.4% and PPV by 53.1%. In a group of actual or past tumours the sensitivity increased by 22% and NPV by 34%, whereas specificity decreased by 26% and PPV by 35%. In 2 cases a drop in FEV1 above 10% of pre-inhalation value was observed but no clinically relevant symptoms were reported. CONCLUSIONS: Photodynamic bronchoscopy with inhalation of 5-ALA is a relatively safe diagnostic method. The main disadvantage is high percentage of false positive results. Nevertheless, we believe, that it may be a useful adjunct to conventional diagnostic modes, especially in the detection of early lesions in patients operated due to cancer (stump control and detection of metachronous lesions) and those prepared for operation (synchronous lesions and detection of infiltration margins). However all suspected lesions must be verified by histo-pathological examination.

Release of hydrogen peroxide by rat type II pneumocytes in the prolonged culture.

Type II pneumocytes (T II pneumocytes) produce hydrogen peroxide (H(2)O(2)), which may be potentially dangerous for the lung. These cells in culture differentiate to type I-like pneumocytes and it may reflect the differentiation which follows the injury of alveolar epithelium. This work was undertaken to estimate the H(2)O(2) release by T II pneumocytes, freshly isolated and cultured up to 8 days. The light and electron microscopy evaluation confirmed the differentiation of T II pneumocytes to type I-like cells. The release of H(2)O(2), estimated spectrofluorimetrically as homovanillic acid oxidation product obtained in the presence of horseradish peroxidase, was significantly higher at day 4 (0.63+/-0. 68nmol/mg protein/min, P

Cellular sources of oxidants in the lung.

Reactive oxygen species (ROS) are important causative factors of many lung diseases, for instance pulmonary emphysema, adult respiratory distress syndrome (ARDS), lung fibrosis or rejection of transplanted lung. Moreover, recent data show that these molecules also play some physiological roles including signal transduction which regulates such important functions as cell growth and apoptosis. This review describes various cellular sources of ROS in the lung. Special attention was paid to neutrophils, eosinophils, alveolar macrophages and cells of alveolar epithelium. A possible contribution of ROS released by these cells to various lung diseases is discussed.

Clinical utility of a commercial ligase chain reaction kit for the diagnosis of smear-negative pulmonary tuberculosis.

SETTING: In paucibacillary forms of smear-negative tuberculosis it is very difficult to establish a correct and rapid diagnosis, as several weeks are usually required to obtain positive results from culture. In the last few years new rapid techniques based on molecular biology for the detection of Mycobacterium tuberculosis have been introduced. OBJECTIVE: The aim of this study was to evaluate the utility of the ligase chain reaction method (LCx, Abbott) for the diagnosis of smear-negative pulmonary tuberculosis. DESIGN: Thirty smear-negative patients with radiographic changes and clinical signs consistent with TB participated in the study. Sputum and bronchial aspirate were assessed according to traditional methods on Löwenstein-Jensen medium, and bronchoalveolar lavage (BAL) was assessed by the LCx test and the Bactec 460 system. Another 30 patients with non-tuberculous infections were included in the study as controls. RESULTS: Of the 30 patients suspected of tuberculosis, 19 had active disease on clinical, bacteriological and radiographic grounds, nine inactive tuberculosis and two had lung cancer. Bacteriological confirmation was obtained in 12 of the 19 (63.2%) patients with active tuberculosis. The sensitivity of sputum culture was 42.1% and bronchial aspirate culture 47.4%. BAL fluid revealed positive results in 57.9% using both LCx and Bactec. The results of the LCx assay can be obtained in 5 hours as opposed to several weeks using other methods. CONCLUSION: The LCx test may be useful in the diagnosis of smear-negative pulmonary tuberculosis and may be recommended in these clinical situations.

Combination of methotrexate and prednizone decreases circulating concentrations of interleukin 1 beta and Interleukin 6 in patients with rheumatoid arthritis. Poor correlation of cytokine suppression with clinical improvement.

OBJECTIVE: To evaluate the effect of methotrexate (MTX) in combination with prednizone on cytokine levels, acute phase proteins and thiobarbituric acid reactive substances (TBAR--an indicator of peroxidative damage to tissue lipids) in the blood of rheumatoid arthritis (RA) patients and to investigate their associations with clinical disease activity. METHODS: We measured blood concentrations of interleukin-1 beta (IL-1 beta), interleukin- 6 (IL-6), TBARs and classical clinical and laboratory indices of disease activity in 36 RA subjects before and after 3 and 6 month treatment with MTX and prednizone. Only RA subjects who stopped any disease-modifying anti rheumatic drugs treatment for last 3 months were included in the study. Baseline cytokine and TBARs levels were compared with those obtained with 20 healthy controls. RESULTS: Compared to controls RA subjects had elevated levels of circulating IL-1 beta (63.3 +/- 47.6 vs 13.7 +/- 7.8 pg/ml, p<0.01), IL-6 (147.2 +/- 76.5 vs 15.9 +/- 13.3 pg/ml, p<0.001) and TBARs (3.11 +/- 0.42 vs 1.34 +/- 0.45 nmol/1, p<0.001) concentrations. MTX in combination with prednizone improved patient clinical status that was accompanied by 1.96-, 1.25-, and 1.35-fold decrease in IL-1 beta, IL-6 and TBARs after 6 month treatment (p<0.001), respectively. Although, IL-1 and IL-6 revealed a few correlations with classical indices of disease activity no association was found between patient clinical status improvement and cytokine changes over 6 month treatment. CONCLUSIONS: MTX in combination with prednizone decreases blood levels of IL-1 beta and IL-6 and inhibits the intensity of free radical- mediated processes in RA subjects. Monitoring of plasma concentrations of these cytokines could not predict the treatment efficacy.

Effect of paraquat intoxication and ambroxol treatment on hydrogen peroxide production and lipid peroxidation in selected organs of rat.

Paraquat (Pq) is a herbicide which is very toxic to all animals and to man. It generates free radicals and leads to acute or chronic lung injury and usually to death. So far, the role of lipid peroxidation of cell membranes in the mechanism of its toxicity has not been proved satisfactorily and therefore in the present study we examined the concentration of hydrogen peroxide (H2O2) and various lipid peroxidation products (LPP) such as conjugated dienes (CD), lipid hydroperoxides (LH), malonyldialdehyde (MDA) and Schiff bases in selected organs of the rat given a single intraperitoneal dose 35 mg kg-1 Pq. We also evaluated the influence of a mucolytic and probably antioxidant drug, ambroxol, on Pq-induced changes in the concentration of H2O2 and LPP. Paraquat increased the hepatic concentration of H2O2, CD, LH and MDA by approximately fourfold. Though the dose of Pq was nearly twice the LD50 dose, we did not notice any changes in the concentration of these substances in the critical organ, lung or heart and kidney. Ambroxol alleviated the increase of H2O2 in the liver but did not reduce the concentration of LPP. Moreover, the drug administered alone induced lipid peroxidation in the liver. Our results indicate that Pq dose not induce H2O2 production and lipid peroxidation in the lung but it increases the concentration of H2O2 and LPP in the liver. Ambroxol inhibits the Pq-induced increase in the concentration of H2O2 in the liver without protecting it against lipid peroxidation. Moreover, the drug alone may act as a pro-oxidant.

Analysis of constitutive and noninducible mutations of the PUT3 transcriptional activator.

The Saccharomyces cerevisiae PUT3 gene encodes a transcriptional activator that binds to DNA sequences in the promoters of the proline utilization genes and is required for the basal and induced expression of the enzymes of this pathway. The sequence of the wild-type PUT3 gene revealed the presence of one large open reading frame capable of encoding a 979-amino-acid protein. The protein contains amino-terminal basic and cysteine-rich domains homologous to the DNA-binding motifs of other yeast transcriptional activators. Adjacent to these domains is an acidic domain with a net charge of -17. A second acidic domain with a net charge of -29 is located at the carboxy terminus. The midsection of the PUT3 protein has homology to other activators including GAL4, LAC9, PPR1, and PDR1. Mutations in PUT3 causing aberrant (either constitutive or noninducible) expression of target genes in this system have been analyzed. One activator-defective and seven activator-constitutive PUT3 alleles have been retrieved from the genome and sequenced to determine the nucleotide changes responsible for the altered function of the protein. The activator-defective mutation is a single nucleotide change within codon 409, replacing glycine with aspartic acid. One activator-constitutive mutation is a nucleotide change at codon 683, substituting phenylalanine for serine. The remaining constitutive mutations resulted in amino acid substitutions or truncations of the protein within the carboxy-terminal 76 codons. Mechanisms for regulating the activation function of the PUT3 protein are discussed.

Isolation of constitutive mutations affecting the proline utilization pathway in Saccharomyces cerevisiae and molecular analysis of the PUT3 transcriptional activator.

The enzymes of the proline utilization pathway (the products of the PUT1 and PUT2 genes) in Saccharomyces cerevisiae are coordinately regulated by proline and the PUT3 transcriptional activator. To learn more about the control of this pathway, constitutive mutations in PUT3 as well as in other regulators were sought. A scheme using a gene fusion between PUT1 (S. cerevisiae proline oxidase) and galK (Escherichia coli galactokinase) was developed to select directly for constitutive mutations affecting the PUT1 promoter. These mutations were secondarily screened for their effects in trans on the promoter of the PUT2 (delta 1-pyrroline-5-carboxylate dehydrogenase) gene by using a PUT2-lacZ (E. coli beta-galactosidase) gene fusion. Three different classes of mutations were isolated. The major class consisted of semidominant constitutive PUT3 mutations that caused PUT2-lacZ expression to vary from 2 to 22 times the uninduced level. A single dominant mutation in a new locus called PUT5 resulted in low-level constitutive expression of PUT2-lacZ; this mutation was epistatic to the recessive, noninducible put3-75 allele. Recessive constitutive mutations were isolated that had pleiotropic growth defects; it is possible that these mutations are not specific to the proline utilization pathway but may be in genes that control several pathways. Since the PUT3 gene appears to have a major role in the regulation of this pathway, a molecular analysis was undertaken. This gene was cloned by functional complementation of the put3-75 mutation. Strains carrying a complete deletion of this gene are viable, proline nonutilizing, and indistinguishable in phenotype from the original put3-75 allele. The PUT3 gene encodes a 2.8-kilobase-pair transcript that is not regulated by proline at the level of RNA accumulation. The presence of the gene on a high-copy-number plasmid did not alter the regulation of one of its target genes, PUT2-lacZ, suggesting that the PUT3 gene product is not limiting and that a titratable repressor is not involved in the regulation of this pathway.