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Biomedical subjects

M Dröge

Publications and source records attributed to M Dröge.

13 recordsLinked to original sources
PubMed2001

The genetic organization and evolution of the broad host range mercury resistance plasmid pSB102 isolated from a microbial population residing in the rhizosphere of alfalfa.

Employing the biparental exogenous plasmid isolation method, conjugative plasmids conferring mercury resistance were isolated from the microbial community of the rhizosphere of field grown alfalfa plants. Five different plasmids were identified, designated pSB101-pSB105. One of the plasmids, pSB102, displayed broad host range (bhr) properties for plasmid replication and transfer unrelated to the known incompatibility (Inc) groups of bhr plasmids IncP-1, IncW, IncN and IncA/C. Nucleotide sequence analysis of plasmid pSB102 revealed a size of 55 578 bp. The transfer region of pSB102 was predicted on the basis of sequence similarity to those of other plasmids and included a putative mating pair formation apparatus most closely related to the type IV secretion system encoded on the chromosome of the mammalian pathogen Brucella sp. The region encoding replication and maintenance functions comprised genes exhibiting different degrees of similarity to RepA, KorA, IncC and KorB of bhr plasmids pSa (IncW), pM3 (IncP-9), R751 (IncP-1beta) and RK2 (IncP-1alpha), respectively. The mercury resistance determinants were located on a transposable element of the Tn5053 family designated Tn5718. No putative functions could be assigned to a quarter of the coding capacity of pSB102 on the basis of comparisons with database entries. The genetic organization of the pSB102 transfer region revealed striking similarities to plasmid pXF51 of the plant pathogen Xylella fastidiosa.

Bacteria↗
PubMed2001

Has blood glucose level measured on admission to hospital in a patient with acute pancreatitis any prognostic value?

BACKGROUND: Early detection of pancreatic necrosis allows better management of the disease. Contrast-enhanced computed tomography (CT) as the gold standard for detecting pancreatic necrosis is expensive. AIM OF THE STUDY: This study was to evaluate for the first time whether blood glucose estimation on hospital admission--a simple, cheap, readily available laboratory parameter--may detect pancreatic necrosis and have prognostic value in acute pancreatitis. METHODS: Single blood glucose estimation upon hospital admission was evaluated prospectively for detecting pancreatic necrosis and as a prognostic indicator. The study included 241 nondiabetic patients with a first attack of acute pancreatitis. All underwent CT within 72 h of admission. RESULTS: High blood glucose (> 125 mg/dl) correlated significantly with complex high clinical and biochemical prognostic scores (Ranson, Imrie), a high Balthazar score, pancreatic pseudocysts, and a long hospital stay, but not with organ failure, indication for artificial ventilation, dialysis, surgery, length of intensive care, and mortality. Pancreatic necrosis detection sensitivity of high blood glucose was 83%, specificity 49%, positive predictive value 28%, and negative predictive value 92%. CONCLUSION: A patient with normal blood glucose on admission is unlikely to have pancreatic necrosis. Contrast-enhanced CT would not be needed unless the patient fails to improve.

Acute Disease↗
PubMed2000

Phenotypic and molecular characterization of conjugative antibiotic resistance plasmids isolated from bacterial communities of activated sludge.

In order to isolate antibiotic resistance plasmids from bacterial communities found in activated sludge, derivatives of the 3-chlorobenzoate-degrading strain Pseudomonas sp. B13, tagged with the green fluorescent protein as an identification marker, were used as recipients in filter crosses. Transconjugants were selected on agar plates containing 3-chlorobenzoate as the sole carbon source and the antibiotic tetracycline, streptomycin or spectinomycin, and were recovered at frequencies in the range of 10(-5) to 10(-8) per recipient. A total of 12 distinct plasmids, designated pB1-pB12, was identified. Their sizes ranged between 41 to 69 kb and they conferred various patterns of antibiotic resistance on their hosts. Two of the plasmids, pB10 and pB11, also mediated resistance to inorganic mercury. Seven of the 12 plasmids were identified as broad-host-range plasmids, displaying extremely high transfer frequencies in filter crosses, ranging from 10(-1) to 10(-2) per recipient cell. Ten of the 12 plasmids belonged to the IncP incompatibility group, based on replicon typing using IncP group-specific PCR primers. DNA sequencing of PCR amplification products further revealed that eight of the 12 plasmids belonged to the IncPbeta subgroup, whereas two plasmids were identified as IncPalpha plasmids. Analysis of the IncP-specific PCR products revealed considerable differences among the IncPbeta plasmids at the DNA sequence level. In order to characterize the gene "load" of the IncP plasmids, restriction fragments were cloned and their DNA sequences established. A remarkable diversity of putative proteins encoded by these fragments was identified. Besides transposases and proteins involved in antibiotic resistance, two putative DNA invertases belonging to the Din family, a methyltransferase of a type I restriction/modification system, a superoxide dismutase, parts of a putative efflux system belonging to the RND family, and proteins of unknown function were identified.

DNA Restriction Enzymes↗
PubMed1998

Horizontal gene transfer as a biosafety issue: a natural phenomenon of public concern.

The transfer of genetic information between distantly or even unrelated organisms during evolution had been inferred from nucleotide sequence comparisons. These studies provided circumstantial evidence that in rare cases genes had been laterally transmitted amongst organisms of the domains bacteria, archaea and eukarya. Laboratory-based studies confirmed that the gene pools of the various domains of organisms are linked. Amongst the bacterial gene exchange mechanisms transduction, transformation and conjugation, the latter was identified as the mechanism with potentially the broadest host range of transfer. Previously, the issue of horizontal gene transfer has become important in the context of biosafety. Gene transfer studies carried out under more natural conditions such as in model ecosystems or in the environment established that all gene transfer mechanisms worked under these conditions. Moreover, environmental hot-spots were identified where favourable conditions such as nutrient enrichment increased the probability of genetic exchange among bacteria. In particular, the phytosphere was shown to provide conducive conditions for conjugative gene exchange. Concern has been expressed that transfer of recombinant DNA (e.g. antibiotic resistance genes) from genetically modified organisms (GMOs) such as transgenic plants to phytosphere bacteria may occur and thus contribute to the undesirable spread of antibiotic resistance determinants. Studies which were performed to address this issue clearly showed that such a transfer occurs, if at all, at extremely low frequency.

Biological Evolution↗
PubMed1998

Intergeneric transfer of conjugative and mobilizable plasmids harbored by Escherichia coli in the gut of the soil microarthropod Folsomia candida (Collembola).

The gut of the soil microarthropod Folsomia candida provides a habitat for a high density of bacterial cells (T. Thimm, A. Hoffmann, H. Borkott, J. C. Munch, and C. C. Tebbe, Appl. Environ. Microbiol. 64:2660-2669, 1998). We investigated whether these gut bacteria act as recipients for plasmids from Escherichia coli. Filter mating with E. coli donor cells and collected feces of F. candida revealed that the broad-host-range conjugative plasmid pRP4-luc (pRP4 with a luciferase marker gene) transferred to fecal bacteria at estimated frequencies of 5.4 x 10(-1) transconjugants per donor. The mobilizable plasmid pSUP104-luc was transferred from the IncQ mobilizing strain E. coli S17-1 and less efficiently from the IncF1 mobilizing strain NM522 but not from the nonmobilizing strain HB101. When S17-1 donor strains were fed to F. candida, transconjugants of pRP4-luc and pSUP104-luc were isolated from feces. Additionally, the narrow-host-range plasmid pSUP202-luc was transferred to indigenous bacteria, which, however, could not maintain this plasmid. Inhibition experiments with nalidixic acid indicated that pRP4-luc plasmid transfer took place in the gut rather than in the feces. A remarkable diversity of transconjugants was isolated in this study: from a total of 264 transconjugants, 15 strains belonging to the alpha, beta, or gamma subclass of the class Proteobacteria were identified by DNA sequencing of the PCR-amplified 16S rRNA genes and substrate utilization assays (Biolog). Except for Alcaligenes faecalis, which was identified by the Biolog assay, none of the isolates was identical to reference strains from data banks. This study indicates the importance of the microarthropod gut for enhanced conjugative gene transfer in soil microbial communities.

Animals↗
PubMed1996

Pulmonary infiltrations. Sign of severe acute pancreatitis.

CONCLUSION: Pleural infiltrates are indicative of severe acute pancreatitis and a negative prognostic parameter for the course of the disease. BACKGROUND: The purpose of this study was to determine the frequency of pulmonary infiltrates in acute pancreatitis and their importance for evaluating the severity of the disease. METHODS: Incidence and localization of pulmonary infiltrates were evaluated in 140 patients with acute pancreatitis. Chest X-ray was obtained within 24 h, and a contrast-enhanced computed tomography within 72 h after admission. Ranson's prognostic parameters were estimated within the first 48 h. RESULTS: Patients with pulmonary infiltrates (n = 36, 26%) had a significantly higher Ranson's score and pancreatic necroses more frequently than patients without this complication, plus a higher mortality rate.

Acute Disease↗
PubMed1996

Diagnostic intervals for recognizing celiac disease.

The aim of this retrospective study was to determine the time intervals between the onset of symptoms and diagnosis of celiac disease on the basis of a questionnaire that was published in the journal of the German Celiac Society (Verbandszeitschrift der Deutschen Zöliakie-Gesellschaft). 408 adult patients in whom the diagnosis of celiac disease was made after the age of 15 responded to the questionnaire. The time interval between the onset of symptoms and diagnosis (total diagnostic interval) was 5.4 (median) and 10.1 +/- 12.3 (mean +/- SD) years, interval-1 (time interval between the onset of symptoms and the first visit to a doctor) was 0.4 (median) and 2.2 +/- 6.6 (mean +/- SD) years, and interval-2 (time interval between the first visit to a doctor and the diagnosis) was 3.9 (median) and 8.0 +/- 10.4 (mean +/- SD) years. The time intervals shortened only a little over the years. At all times, interval-2 was significantly longer than interval-1. There were no differences between female (n = 328) and male (n = 80) patients and between the age groups. Furthermore, none of the gastrointestinal and non-gastrointestinal symptoms had had a distinct influence on all diagnostic intervals and also the fact that other family members having the disease did not shorten any of the intervals. In summary, the diagnostic intervals for recognizing celiac disease are still unacceptably long. More public awareness work has to be done so that patients can recognize their symptoms and doctors especially can suspect celiac disease sooner and perform the necessary diagnostic procedures when patients present with suggestive symptoms.

Adolescent↗
PubMed1995

Drug induced acute pancreatitis: incidence and severity.

To determine the incidence and severity of drug induced acute pancreatitis, data from 45 German centres of gastroenterology were evaluated. Among 1613 patients treated for acute pancreatitis in 1993, drug induced acute pancreatitis was diagnosed in 22 patients (incidence 1.4%). Drugs held responsible were azathioprine, mesalazine/sulfasalazine, 2',3'-dideoxyinosine (ddI), oestrogens, frusemide, hydrochlorothiazide, and rifampicin. Pancreatic necrosis not exceeding 33% of the organ was found on ultrasonography or computed tomography, or both, in three patients (14%). Pancreatic pseudocysts did not occur. A decrease of arterial PO2 reflecting respiratory insufficiency, and an increase of serum creatinine, reflecting renal insufficiency as complications of acute pancreatitis were seen in two (9%) and four (18%) patients, respectively. Artificial ventilation was not needed, and dialysis was necessary in only one (5%) case. Two patients (9%) died of AIDS and tuberculosis, respectively; pancreatitis did not seem to have contributed materially to their death. In conclusion, drugs rarely cause acute pancreatitis, and drug induced acute pancreatitis usually runs a benign course.

Acute Disease↗
PubMed1994

Pleural effusions: a new negative prognostic parameter for acute pancreatitis.

OBJECTIVE: To evaluate the incidence, localization, and size of pleural effusions in 133 patients with acute pancreatitis. METHODS: A contrast-enhanced computed tomographic scan was prospectively obtained within 72 h after admission. RESULTS: Patients with pleural effusions (66 = 50%) had significantly more severe morphological changes of the pancreas and necroses (independent of the size and localization of the effusions and etiology of the acute pancreatitis), more often had a pancreatic pseudocyst, and had a higher mortality rate than patients without this complication. CONCLUSION: Pleural effusions are indicative of severe acute pancreatitis and are a negative prognostic parameter for the course of the disease.

Acute Disease↗
PubMed1990

Preservation of the porcine pancreas with HTK and Euro-Collins solution: studies in a reperfusion system.

The present study compares the preservation of the porcine pancreas by the standard Euro-Collins solution or the cardioplegic histidine-tryptophan-ketoglutarate solution (HTK). The explanted pancreas was stored at 4 degrees C for 6 and 24 h respectively, following which organ quality was assessed in a reperfusion chamber measuring physiological and biomedical parameters. After 6 h ischaemia, the amount of lactate was significantly lower when HTK was used for protection. Other parameters like insulin release, amylase release, vascular resistance and oxygen consumption of the pancreas did not indicate a significant difference. Protection with HTK significantly improved pancreas preservation after 24 h ischaemia: lactate content in the reperfusate was lower (HTK: 64.0 +/- 7.2 mumol 50 ml-1 n = 8, v. EC: 114.2 +/- 1.7 mumol 50 ml-1, n = 6), the arteriovenous flow rate was higher (HTK: 5.7 +/- 0.91 ml min-1 v. EC: 3.0 +/- 0.26 ml min-1), and the pancreatic oxygen consumption was increased (HTK: 2.15 +/- 0.22 microliter O2 min-1 g-1 v. 0.47 +/- 0.08 microliter O2 min-1 g-1). We conclude that pancreas preservation can be improved in vitro by protection with HTK solution.

Amylases↗