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K Lewandowski

Publications and source records attributed to K Lewandowski.

At least 19 recordsLinked to original sources
PubMed2002

Comparative studies of the Acinetobacter genus and the species identification method based on the recA sequences.

The recA gene is indispensable for a maintaining and diversification of the bacterial genetic material. Given its important role in ensuring cell viability, it is not surprising that the RecA protein is both ubiquitous and well conserved among a range of prokaryotes. Previously, we reported Acinetobacter genomic species identification method based on PCR amplification of an internal fragment of the recA gene with subsequent restriction analysis (RFLP) with HinfI and MboI enzymes. In present study, the PCR products containing the internal fragment of the recA gene, for 25 Acinetobacter strains belonging to all genomic species, were sequenced. Based on the nucleotide sequences the restriction maps and phylogenetic tree were prepared. The restriction maps revealed that Tsp509I restriction enzyme is the most discriminating for RFLP. To verify the computer analysis, the amplified DNAs from all reference genomic species available (43 strains) and 34 clinical strains were digested with each of the three restriction endonucleases mentioned. The results of digestion confirmed the computer analysis. The reconstructed phylogenetic tree showed linkages between genomic species 1 (Acinetobacter calcoaceticus), 2 (Acinetobacter baumannii), 3, 'between 1 and 3', TU13 and 'close to TU13'; genomic species 4, 6, BJ13, BJ14, BJ15, BJ16 and BJ17; genomic species 7 (Acinetobacter johnsonii) and TU14; genomic species 10 and 11; genomic species 8 (Acinetobacter Iwoffii), 9, 12 (Acinetobacter radioresistens) and TU15; and genomic species 5 (Acinetobacter junii). It is interesting that one branch in the phylogenetic tree contains haemolytic species-genomic species 4 (A. haemolyticus), BJ13, BJ14, BJ15, BJ16 and BJ17. The proposed genotypic method clearly revealed that the RFLP profiles obtained with Tsp509I enzyme might be useful for species identification of Acinetobacter strains. In this context, recA/RFLP genotypic method should be seen as an ideal preliminary screening method for large numbers of isolates, with the ultimate confirmatory role reserved for DNA hybridization analysis.

Acinetobacter↗
PubMed2002

[Can lung protective ventilation methods modify outcome?--A critical review].

A large body of experimental and clinical work leaves no room for doubt that mechanical ventilation can contribute to the progression of a lung disease or, in the worst case, produce acute pulmonary damage. The pathophysiological processes involved have been described as barotrauma, volutrauma, atelectrauma and biotrauma. In response, a socalled lung-protective ventilation strategy has been proposed, especially for patients with acute respiratory distress syndrome (ARDS). Such an approach seeks to apply limited airway pressures, small tidal volumes and appropriate levels of positive end-expiratory pressures even if, as a consequence, non-physiological gas exchange values (i.e. elevated PaCO2-levels) need to be tolerated. A recent large prospective randomized trial demonstrated reduced mortality rates using such a strategy. To support lung-protective ventilation in ARDS patients, an array of therapeutic measures has been proposed, including meticulous attention to fluid and transfusion management, prone position, extracorporeal membrane oxygenation (ECMO), inhalation of nitric oxide, implementation of spontaneous breathing, partial liquid ventilation and tracheal gas insufflation. Of these, only prone positioning has become part of routine clinical management, while ECMO is applied in selected cases only. Unfortunately, thus far, none of these measures has passed the litmus test of a randomized controlled trial. Recent large prospective observational studies, however, suggest that only an optimized concert of therapeutic interventions, but not a single measure alone, may improve the outcome of ARDS patients.

Animals↗
PubMed2001

Effects of insulin and glucocorticoids on the leptin system are mediated through free leptin.

OBJECTIVE: Insulin and glucocorticoids are known to increase total leptin levels. However, the effects of insulin and glucocorticoids on the components of the leptin system - free leptin (FL), bound leptin (BL) and soluble leptin receptor (SR) - have not been elucidated. The aim of this study was to determine if there is a differential effect of insulin and glucocorticoids on the leptin system. MATERIAL AND METHODS: In the first of two studies (study 1), we measured free leptin (FL), bound leptin (BL), a soluble leptin receptor (SR) and insulin, by specific RIA methods, in six healthy subjects on a control day, and subsequently during a hyperinsulinaemic euglycaemic clamp study. In the second study (study 2) we measured the same parameters in six healthy subjects, before (day 1) and during administration of dexamethasone over 3 consecutive days. RESULTS: In study 1, on the control day FL levels rose over the 16 h monitoring period (P = 0.057) and SR levels declined (P < 0.001), but there was no change of BL levels. Even after accounting for diurnal variation, FL levels increased even more substantially over 12 h of insulin infusion than observed on the control day (P < 0.001). In study 2, mean FL concentration doubled from day 1 to day 2 (P = 0.01) and remained elevated subsequently. In contrast to FL, BL and SR levels remained unchanged during the study. Fasting insulin levels (pmol/l) increased from day 1 to day 2, but this rise only approached significance on day 4 (P = 0.05). CONCLUSION: We conclude that insulin and dexamethasone increase free leptin levels, but do not change the concentrations of bound leptin and soluble leptin receptor. Furthermore, the dexamethasone-induced rise in leptin levels is (at least partially) independent of the effects of glucocorticoid-induced hyperinsulinaemia.

Adult↗
PubMed2001

Creation of an additional glycosylation site as a mechanism for type I antithrombin deficiency.

We report the identification of a new mutation resulting in type I antithrombin (AT) deficiency and the mechanism by which the deficiency arose. The single base substitution of G to A at nucleotide 2709 was identified in a proband with a family history of venous thrombosis. The mutation results in a substitution of 82 Ser by Asn, creating a new glycosylation site. Expression studies were then carried out, to confirm Asn-linked glycosylation occurred at this consensus site and that this resulted in the AT deficient phenotype. Cell-free translations using rabbit reticulocyte lysate in the presence of microsomes demonstrated that the 82 Asn variant was post-translationally processed efficiently. The 82 Asn variant protein was of a higher molecular weight than normal AT. consistent with the addition of a fifth glycan chain. Incubation of translation product with endoglycosidase H, confirmed that the higher molecular weight product had resulted from additional carbohydrate. Expression of the 82 Asn variant in COS-7 cells resulted in intracellular accumulation, with a low level of secretion of the protein into culture supernatant, consistent with type I AT deficiency. The addition of an extra carbohydrate side chain to residue 82 of antithrombin may block post-translational folding. trapping the variant intracellulary.

Adolescent↗
PubMed2001

Significance of molecular identification of hepatitis C virus RNA in diagnosis of cryptogenic hepatitis in children.

Viral etiology of hepatitis is routinely proved by standard immunological tests detecting specific antibodies. However, identification of specific antibodies cannot always be conclusive. Since specific hepatitis C virus (HCV) antibodies may appear after some months of the infection, identification of HCV RNA and/or hepatitis G virus (HGV) RNA should clarify the etiology of hepatitis. The aim of this study was to diagnose etiologically unknown hepatitis by a reverse transcription-polymerase chain reaction (RT-PCR) testing of the presence of HCV RNA and HGV RNA. The study involved 33 children with histologically proved hepatitis. The presence of HCV and any signs of autoimmune disease were not observed at the beginning of the follow-up study. During 2.5 years of the follow-up HCV-RNA was found in the blood and liver biopsies in 17 patients. Eight of them became HCV antibodies-positive during the follow-up. None of them eliminated the virus from the blood during the follow-up. In two other patients HCV-RNA was found only in the liver. HGV infection in all cryptogenic patients was excluded by PCR testing. Identification of HCV RNA RT-PCR allowed to diagnose 19 out of 33 (57.6%) patients with cryptogenic hepatitis. The etiology of the hepatitis in remaining 12 patients has to be established.

Child↗
PubMed2001

Hepatitis G virus co-infection may affect the elimination of hepatitis C virus RNA from the peripheral blood of hemodialysis patients.

Hemodialysis patients are at risk for hepatitis C virus (HCV) and hepatitis G virus (HGV) infection. The aim of this study was to investigate the possible influence of HGV co-infection on HCV RNA elimination from the peripheral blood of hemodialysis patients. The study involved 144 persons, all with HCV antibodies and HCV RNA. Among 144 patients 24 (16.7%) were positive for HGV RNA. After 2.5 years of observation 80 patients (55.6%) were still HCV RNA-positive. In the latter group 18 patients were co-infected with HGV and 62 were HGV RNA-negative. During 2.5 years of the follow-up study 64 patients eliminated HCV RNA from the serum. In this group only 6 patients were HGV co-infected. None of the HGV-positive patients eliminated HGV RNA from the serum. The higher incidence of HGV co-infection in the group of patients who remained HCV RNA-positive (18/80, 22.5%), in comparison to the group of HCV antibodies-positive patients who lost HCV in the blood (6/64, 9.4%, P < 0.0001) suggests, that the co-infection with HGV may delay the spontaneous elimination of HCV RNA from the blood.

Adult↗
PubMed2000

Extracorporeal membrane oxygenation for severe acute respiratory failure.

Extracorporeal membrane oxygenation (ECMO) is a technique for providing life support, in case the natural lungs are failing and are not able to maintain a sufficient oxygenation of the body's organ systems. ECMO technique was an adaptation of conventional cardiopulmonary bypass techniques and introduced into treatment of severe acute respiratory distress syndrome (ARDS) in the 1970s. The initial reports of the use of ECMO in ARDS patients were quite enthusiastic, however, in the following years it became clear that ECMO was only of benefit in newborns with acute respiratory failure. In neonates treated with ECMO, survival rates of 80% could be achieved. In adult patients with ARDS, two large randomized controlled trials (RCTs) published in 1979 and 1994 failed to show an advantage of ECMO over conventional treatment; survival rates were only 10% and 33%, respectively, in the ECMO groups. Since then, ECMO technology as well as conventional treatment of adult ARDS have undergone further improvements. In conventional treatment lung-protective ventilation strategies were introduced and ECMO was made safer by applying heparin-coated equipment, membranes and tubings. Many ECMO centres now use these advanced ECMO technology and report survival rates in excess of 50% in uncontrolled data collections. The question, however, of whether the improved ECMO can really challenge the advanced conventional treatment of adult ARDS is unanswered and will need evaluation by a future RCT.

Acute Disease↗
PubMed2000

Nasal, pulmonary and autoinhaled nitric oxide at rest and during moderate exercise.

OBJECTIVE: To investigate nasal nitric oxide (NO) excretion, pulmonary NO excretion, and autoinhalation of nasally released NO at rest compared with that during moderate exercise in smokers and non-smokers. DESIGN: Prospective observational study. SETTING: University laboratory. PARTICIPANTS: Fourteen healthy adult volunteers. INTERVENTIONS: Breathing of NO-purified air supplied via a tube system at rest and during a bicycle-ergometer workload of 60 Watt over a time of 10 min. MEASUREMENT AND RESULTS: We examined nasal and pulmonary NO excretion in smoking (n = 7) and non-smoking (n = 7) adult human volunteers. At rest, we measured constant nasal NO excretion rates of 311 +/- 89 nl/min for non-smokers and 261 +/- 142 nl/min for smokers (mean +/- SD, n.s.). During 60 W exercise, nasal NO release remained unchanged, while pulmonary NO excretion doubled compared with the rates at rest (non-smokers: 40 +/- 21 nl/min versus 23 +/- 14 nl/min, p < 0.05; smokers: 41 +/- 8 nl/min versus 22 +/- 8 nl/min, p < 0.05). The differences between smokers and non-smokers in nasal or pulmonary NO excretion were not significant. To determine the autoinhaled amount of nasally released NO, we also measured the NO concentration within the nasopharynx of five volunteers during nasal breathing. The average inhaled NO concentration was 17.8 +/- 3.1 ppb at rest and this decreased to 9.3 +/- 1.8 ppb during exercise of 60 W, while minute ventilation approximately doubled from 9 +/- 2 to 21 +/- 3 l/min. CONCLUSION: Our results demonstrate that moderate exercise increased exclusively pulmonary NO excretion. Nasal NO release, which is 10 times higher at rest, was not changed. The decrease in autoinhaled NO concentration during exercise results from dilution of the continuous nasal release by the increased respiratory gas flow. The individual NO release allows no conclusion about smoking habits.

Adult↗
PubMed2000

Cladribine with or without prednisone in the treatment of previously treated and untreated B-cell chronic lymphocytic leukaemia - updated results of the multicentre study of 378 patients.

Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were also treated with prednisone. A total of 194 patients were previously untreated, and 184 had relapsed or refractory disease after previous other therapy. Complete response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138 (36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were achieved more frequently in patients in whom 2-CdA was a first-line treatment (45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4% respectively) (P < 0.0001). The median duration of OR for previously untreated patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The median survival evaluated from the beginning of 2-CdA treatment was shorter in the pretreated group (16.3 months) than in the untreated group (19.4 months) (P < 0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63 (32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P) and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4). In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2-CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in 91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most frequent toxic effects. Our results indicate that 2-CdA is an effective, relatively well-tolerated drug, especially in previously untreated CLL.

2-Chloroadenosine↗
PubMed1999

On-bead combinatorial approach to the design of chiral stationary phases for HPLC.

A library of 36 L-amino acid anilides, which are potential selectors for chiral HPLC, was synthesized in solution and attached to functionalized macroporous polymer beads. The best selector from the library was identified by a deconvolution process using the HPLC separation of several racemic N-(3,5-dinitrobenzoyl)-alpha-amino acid alkylamides as a probe. In each deconvolution step, a series of chiral stationary phases (CSPs) containing a subset of the amino acid anilide selector library was screened for enantioselectivity. After the best CSP was chosen, the library was further deconvoluted until the single best selector was found. The highest selectivity was obtained with a L-proline-1-indananilide that exhibited alpha values up to 23 under normal-phase HPLC conditions. In addition, six CSPs were prepared using individual selectors from the library, and screening results indicate that the deconvolution process indeed led to the most selective receptor.

Amino Acids↗
PubMed1999

A combinatorial approach to recognition of chirality: preparation of highly enantioselective aryl-dihydropyrimidine selectors for chiral HPLC.

A parallel library of 108 4-aryl-1,4-dihydropyrimidine (DHPM) enantiomers, which are potential selectors for chiral HPLC separations, was synthesized using the single-step Biginelli multicomponent condensation. The individual compounds were screened by observing the enantioselectivity for resolution on a "brush-type" L-(3,5-dinitrobenzoyl)leucine-based chiral stationary phase, and separation factors alpha up to 12 were achieved. The best candidates from the library contained an ortho-substituted aromatic group at C4 carbon atom of the pyrimidine ring and an alkyl substituent at N1 nitrogen atom. Resolution of the enantiomers of the lead compound, 4-(9-phenanthryl)-DHPM 8, using semipreparative chiral HPLC followed by attachment to monodisperse macroporous aminomethacrylate beads, provided the novel polymer based chiral stationary phase with good enantioselectivities in the resolution of several pi-acidic aryl-dihydropyrimidines and derivatized profens. In addition, 3,5-dinitrobenzamido derivatives of alpha-amino acids could be resolved under normal phase HPLC conditions with separation factors up to 8.

Chromatography, High Pressure Liquid↗
PubMed1999

[Knowledge-based diagnosis and therapeutic recommendations with fuzzy-set theory methods in patients with acute lung failure (ARDS)].

OBJECTIVE: Since the treatment of patients with severe ARDS using the extracorporal lung assist (ECLA) methods remains a cost intensive and speculative procedure, a knowledge based computer system should be created and evaluated in order to support clinical decisions. METHODS: The model was based on the fuzzy set theory and therefore able to give decisions between yes and no, that means that a criterion could also be fulfilled to 35% or 80% for example. The development of this computer program consists of two steps: first, the entry criteria for the ECLA therapy were established within a framework of an international evaluation of clinical data from 3 centres (Berlin, Marburg, Vienna). Here, inherent vagueness, uncertainty of the occurrence and limited availability of medical data are to be considered to establish a useful tool. Secondly, this was done by grouping and weighting of parameters by the system and the status of each patient or patient group was assigned by the percentage of fulfillment of the criterion. RESULTS: By using a mixed sample of patients from these three centres, the fulfillment of entry criteria according either to definitions of Berlin or to definition of Marburg was different (68% versus 36%). Other differences (36% vs. 22% and 68% vs. 60%) were found between the fuzzy based score and the crisp score which represents the usually performed method. CONCLUSIONS: This now preevaluated minimal data set to describe severe ARDS patients based on the fuzzy set theory may be useful to evaluate patients for ECLA therapy or for another controlled ARDS-therapy.

Acute Disease↗
PubMed1999

Effect of a 2-hour infusion of 2-chlorodeoxyadenosine in the treatment of refractory or previously untreated Waldenström's macroglobulinemia.

2-Chlorodeoxyadenosine (2-CdA) is a new purine analogue active in indolent lymphoid malignancies. In this retrospective study 22 patients with Waldenström's macroglobulinemia (MW) were treated with 2-CdA given in 2-h intravenous infusions. Nine of them were untreated and 13 relapsed or were refractory to previous therapeutic modalities with chlorambucil/prednisone (11 patients) or COP (2 patients). The patients were given 1-11 (median 4) courses of 2-CdA at the dose of 0.14 mg/kg daily in 2-h intravenous infusion for 5 consecutive days. The courses were repeated every 28-35 d. If severe myelosuppression or infection developed, 2-CdA therapy was stopped until the haematological parameters increased. The effectiveness of the treatment was evaluated after the 3 cycles and after completion of therapy. None of the patients has achieved complete response (CR) after 3 courses of treatment and only one (4.5%) has obtained CR after 5 courses. Partial response (PR) was achieved in 8 (36.4%) patients, giving an overall response rate of 40.9%. Ten further patients (45.4%) responded to the treatment with less than 50% decrease in monoclonal protein (defined as stabilisation). There was no significant difference between the response rate in previously pretreated (38.5%) and untreated (44.4%) patients (p>0.05). Mean observed decrease in monoclonal protein was 41%. In the group of 9 patients responding to 2-CdA treatment mean duration of response was 12 months (range 3-34). Myelosuppression was the most prominent side-effect. Neutropenia was present in 17 (77.3%) and thrombocytopenia in 7 (31.8%) patients. In 6 patients myelosuppression was the reason for treatment discontinuation after 1 or 2 courses without significant therapeutic effect. Seven patients died, including 4 from the responding group and all three non-responding patients. Treatment-related thrombocytopenia and fatal haemorrhage was the course of death in 1 patient. In conclusion, the results of our study show that 2-CdA given in 2-h infusions is an effective agent in WM and may be given on an outpatient basis. However, myelosuppression is frequent and the drug must be administered with caution.

Adult↗
PubMed1999

Childhood asthma: exhaled nitric oxide in relation to clinical symptoms.

Bronchial asthma is associated with increased levels of exhaled nitric oxide which are suppressible by glucocorticosteroid inhalation. Children with bronchial asthma were studied to elucidate the relation between endogenous NO release and recent symptoms of bronchial obstruction. Twenty-five children with atopic asthma and 11 healthy control subjects were enrolled and exhaled NO was studied using chemiluminescence analysis. The subjects breathed purified air (<0.5 parts per billion (ppb) NO) exclusively through their mouths. Orally expired NO was measured during continuous nasal aspiration (1.3 L x min(-1)) to remove nasally produced NO. Nasal NO concentration was determined within the aspirated gas. Orally expired NO concentration was 2.5+/-0.3 ppb (mean +/-SEM) in healthy control subjects, 3.19+/-0.88 ppb (NS) in symptom-free children, and 8.28+/-0.81 ppb (p< or =0.01) in children with bronchial asthma who had had recent symptoms of bronchial obstruction. Similarly, in the subgroup of children treated regularly with inhaled glucocorticosteroids those with recent symptoms had significantly higher orally exhaled NO concentrations than healthy control subjects (9.5+/-1.5 ppb, p<0.05). The nasal NO concentration was 152.8+/-12.7 ppb in healthy control subjects and not significantly different in asthmatic children. In this group of asthmatic children, recent symptoms of bronchial obstruction were linked to significantly higher concentrations of NO in orally exhaled gas and to increased oral NO excretion rates. If substantiated by further studies, measurement of orally exhaled NO during nasal aspiration may become useful to monitor disease control in asthmatic children.

Asthma↗