PubMed Health⌕ Search

Biomedical subjects

D Jonas

Publications and source records attributed to D Jonas.

At least 37 records · Page 2Linked to original sources
PubMed2003

Comparison of PCR-based methods for typing Escherichia coli.

OBJECTIVE: To establish a library typing system appropriate for studying cross-transmission of Escherichia coli. METHODS: Eighteen epidemiologically unrelated isolates were genotyped by means of pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), repetitive (rep) PCR, and fluorescent amplified fragment length polymorphism (AFLP). Fingerprints were analyzed either by Pearson correlation or, in the case of AFLP, by Dice coefficients employing the novel 'uncertain band' software tool from GelCompar II. During a nine-month period, 112 isolates taken from 93 patients hospitalized in five intensive care units were analyzed by use of the two most discriminative PCR typing methods. RESULTS: Genotyping by RAPD and rep-PCR revealed insufficient discrimination. Among 18 epidemiologically unrelated strains with 17 different PFGE patterns, IS3 rep-PCR and AFLP distinguished 10 and 18 types, respectively. Comparison of the different methods for analysis of AFLP fingerprints showed that the Dice coefficients, which ignore 'uncertain bands', offered the best concordance with visual interpretation. Consecutive isolates originating from the same patient differed in less than three fragments. CONCLUSIONS: AFLP analysis showed the highest discriminative capacity for PCR typing of E. coli isolates. Analysis of fingerprints employing the Dice coefficients proved the most efficient method for an automated software-based retrieval of visually indistinguishable genotypes in an AFLP fingerprint database.

Bacterial Typing Techniques↗
PubMed2003

[MRI staging of prostate cancer with the combined endorectal body phased-array coil and histologic correlation].

PURPOSE: Evaluation of the diagnostic value of the combined endorectal body-phased array technique regarding the staging of prostate cancers, especially in the differentiation between stages T2 and T3. MATERIALS AND METHODS: Forty-two patients with biopsy-proven or clinically suspected prostate cancer were examined on a 1.5 T scanner (Siemens, Symphony) prior to radical prostatectomy. T (2)-weighted TSE (axial, coronal) and T (2)-weighted FSE (axial) sequences were obtained with and without fat suppression. After application of 0.2 mmol/kg body-weight Gd-DTPA, T (1)-weighted GRE sequences were obtained using dynamic MRI. All images were prospectively interpreted by two observers. The MR images were correlated with the histopathological findings of wide-area sections of prostatectomy specimens. RESULTS: For the detection of extracapsular growth and seminal vesicle infiltration (T2 versus T3) the accuracy was between 94 % and 97 % (sensitivity 100 %, specificity between 87 % and 93 %, observer 1 and 2). In two cases with a histologically proven stadium pT2b, observer 1 had diagnosed stadium pT3a. The results of observer 2 were marginally better in only one case, which was histologically proven to be pT2b and overstaged as pT3a. MRI did not lead to under-staging of a single tumor with regard to the differentiation between T2 and T3. Overall, the staging of the tumor stages (T1 - T4) was correct in 25 of 33 cases (75 %). The dynamic MRI showed no improvement regarding sensitivity (100 %) and specificity (62 %) and achieved a staging accuracy of only 75 %. CONCLUSION: MRI performed with a combination of a pelvic phased-array coil (PPA) and integrated endorectal coil plays a significant role in the preoperative staging of prostate cancer. However, differentiation between capsular infiltration (T2) and penetration (T3) as well as evaluation of the seminal bladder (T3b) seem to be difficult.

Aged↗
PubMed2002

Diversity of Staphylococcus aureus strains isolated from two European regions with different prevalences of methicillin resistance.

The genodiversity of Staphylococcus aureus isolates from the Nottingham region of the United Kingdom was compared with isolates from the Freiburg region of Germany. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) isolates was higher in Nottingham than in Freiburg. In patients from Nottingham hospitals, 80% of MRSA isolates were classical epidemic MRSA-15, but genotypic variants of epidemic MRSA-15 comprised 72% of isolates from Nottingham community-based patients. In contrast, MRSA isolates from Freiburg showed greater diversity, but 47% and 23% of isolates, respectively, belonged to two predominant MRSA genotypes found in isolates from both hospitalised and community-based patients. The results suggest that genodiversity becomes increasingly more confined in settings with a higher frequency and longer duration of MRSA prevalence.

Genetic Variation↗
PubMed2002

Designation of the European Working Group on Legionella Infection (EWGLI) amplified fragment length polymorphism types of Legionella pneumophila serogroup 1 and results of intercentre proficiency testing Using a standard protocol.

The utility of amplified fragment length polymorphism (AFLP) analysis as a genotyping method for the epidemiological typing of Legionella pneumophila serogroup 1 has been previously demonstrated. This study (i). reports recommendations for the designation of the European Working Group on Legionella Infections (EWGLI) AFLP types, (ii). describes the EWGLI AFLP types identified for the 130 strains in the EWGLI culture collection, and (iii). reports the results of a newly introduced international programme of proficiency testing. Following preliminary analysis of 20 epidemiologically unrelated isolates, 16 major AFLP types were identified. A coded proficiency panel, comprising 12 additional isolates representing 9 of these 16 AFLP types, was sent to 17 centres in 14 European countries where it was analysed following a previously determined standard protocol. The identity of each coded strain (recorded as AFLP type 001-016 or untypeable) was determined by participants with reference to these 16 AFLP types, either visually or using gel analysis software where available, and reported to the coordinating centre. Nine of the 12 strains, including an epidemiologically related pair and two pairs of unrelated isolates of the same type, were correctly identified to the correct AFLP type by all or all but one of the participants. Seven laboratories correctly identified all 12 isolates, and a further seven laboratories correctly identified 11. Type identification scores ranged from 75% (1 centre), 83% (2 centres), and 92% (7 centres) to 100% (7 centres). The AFLP method as described is robust and rapid and allows the genotypic comparison of isolates of Legionella pneumophila between different testing centres without the need for exchange of the strains studied.

Bacterial Typing Techniques↗
PubMed2002

MRI and color-coded duplex sonography: diagnosis of partial priapism.

A case of partial priapism is reported diagnosed by contrast-enhanced MR imaging and color-coded duplex sonography. Follow-up examinations after 4 weeks and 3 months were performed. According to the results of color-coded duplex sonography and MRI, a partial priapism with development from the subacute stage to a fibrous residuum after spontaneous lysis was diagnosed. There are only very few cases of partial priapism reported in the literature and this is the first case report that demonstrates diagnosis and follow-up both by color-coded duplex sonography and contrast-enhanced MR imaging.

Diagnosis, Differential↗
PubMed2002

[Robot-assisted laparoscopy in urology. Radical prostatectomy and reconstructive retroperitoneal interventions].

Complex reconstructive laparoscopic procedures in the field of urology such as radical prostatectomy and pyeloplasty have attracted increased attention in the past 2 years. However, extensive laparoscopic experience is required to master these procedures. Therefore, it remains questionable whether these techniques, which have been shown to be of profit to the patient in the hands of a specialist, will achieve widespread distribution. We have employed computer technology to bridge the gap between open surgery and laparoscopic access and used the daVinci Surgical System to establish laparoscopic radical prostatectomy as well as pyeloplasty and other retroperitoneal procedures at our institution. With experience of more than 70 procedures, we find that with the assistance of the daVinci Surgical System both radical prostatectomy and retroperiteoneal procedures can be easily translated from open to minimally invasive procedures with a considerably shorter learning curve and without compromising patient safety. We expect that large incisions will be soon a thing of the past in urologic surgery. Computer technology, together with mechanical engineering, will play a major role in enabling us to achieve better results despite minimal invasiveness.

Female↗
PubMed2002

[The Frankfurt concept for health counseling for men].

The discussion on the difference between the sexes received significant impulses from the formation of feminist theory. Masculinity was interpreted in a rather morally negative manner. Masculinity continuously endeavors to achieve reproduction and self-confirmation. Competitive pursuit of hegemony is the preeminent pattern by which masculine identity is formed. Male socialization leads to externalization, which impedes the development of communicative skills. Males tend to lead a high-risk life-style, which instrumentalizes their body. Symptoms are less often interpreted as warning signals, reflected in a significantly reduced life expectancy in comparison to females. In view of the specific male socialization, the Frankfurt concept of "men's health counseling" attempts to create a professional atmosphere in which men seeking advice are offered the opportunity to consult a specialist on all topics of men's health anonymously and, for the moment, free of charge.

Gender Identity↗
PubMed2002

[LaMedica. The medical education academy on the internet].

At present, "modern media" are still a novelty in medical education. The "LaMedica Project"--a program supported by the Federal Ministry for Education and Research--intends to provide an Internet-based education and training system for the entire field of medicine, using all available media resources. This online educational program will provide subjects for medical laypersons as well as medical experts. Various styles of learning and different learning requests will be promoted. The project presented mirrors the cutting edge of database technology, computer-based training and media didactics, critical content processing as well as supplying individual subjects. This report summarizes our 10 months of experience with this program at the Department for Urology and Pediatric Urology of the Johann Wolfgang Goethe University of Frankfurt Main.

Computer-Assisted Instruction↗
PubMed2002

Effect of skin disinfection with octenidine dihydrochloride on insertion site colonization of intravascular catheters.

BACKGROUND: We investigated the efficacy of two commercially available, alcohol-based antiseptic solutions in decontaminating the insertion site of central lines. One solution contained the bispyridine octenidine dihydrochloride. PATIENTS AND METHODS: Inpatients receiving either a central venous catheter (CVC) or a peripherally inserted central catheter (PICC) were alternately assigned to different skin disinfection regimens at the insertion site: (A) 0.1% octendine dihydrochloride with 30% 1-propanol and 45% 2-propanol, (B) 74% ethanol with 10% 2-propanol. Quantitative skin cultures were obtained from the insertion site at predetermined intervals. RESULTS: A total of 60 patients received 12 CVCs and 47 PICCs (no significant difference with respect to gender, age and catheter type). In total, 90 cultures were assessed in each group. The median colony-forming unit (cfu) counts per 24 cm(2) (group A vs B) were 2,270 vs 2,950 before, 20 vs 40 following and 860 vs 1,210 24 h after catheter insertion, respectively. A statistically significant difference in the efficacy of skin decontamination was seen between groups in culture set (3) and in the difference between culture sets (2) and (3) (Wilcoxon rank sum test). CONCLUSION: Octenidine/propanol appears to be more effective than alcohol (ethanol/propanol) alone in reducing microflora of the skin at the PICC/CVC insertion site over a 24-h period.

1-Propanol↗
PubMed2001

Reversal of multidrug resistance and increase in plasma membrane fluidity in CHO cells with R-verapamil and bile salts.

Studies with multidrug resistance modifiers indicate that perturbations of the cell membrane structure may influence P-glycoprotein (P-gp)-mediated drug transport. We describe studies of plasma membrane order using electron-paramagnetic resonance (EPR) in resistant (CH(R)C5) and sensitive (AUXB1) chinese hamster ovary cells treated with R-verapamil and bile salts. Cell growth rates were determined in presence of doxorubicin mitomycin and cisplatin. The plasma membrane order in untreated resistant cells was higher than in the sensitive cells. Both the bile salt taurochenodeoxycholate (TCDC; 0.2-1.6 mM) and R-verapamil (1-3 microM) lowered the membrane order in the CH(R)C5 cells to that in the sensitive cells and reversed the resistance to doxorubicin and mitomycin. The bile salt tauroursodeoxycholate (TUDC; 0.2-3 mM) did not lower membrane order and did not sensitise CH(R)C5 cells. Neither R-verapamil, TCDC nor TUDC reduced the membrane order of the sensitive cells AUXB1 cells. These results support the view that changes in multidrug resistance in Chinese hamster ovary cells and P-gp function are associated with alterations in the fluidity of the plasma membrane.

Animals↗
PubMed2001

Panhypopituitarism associated with severe retroperitoneal fibrosis.

A 43-year-old man, with a history of central diabetes insipidus diagnosed 3 years previously, complained about reduced libido. An MRI scan showed a suprasellar lesion just below the supraoptic recess of the third ventricle. A stereotactically guided biopsy revealed fibrous glia, but no other specific tissue and no inflammatory cells. Two months later the patient presented with fatigue and muscular weakness. Tertiary adrenal failure and hypothyroidism were diagnosed by endocrine function tests and therapy with levothyroxine and hydrocortisone was started. Another 2 months later the patient was admitted with giddiness, nausea, peripheral oedema and oliguria. Radiological imaging and an open transperitoneal kidney exploration showed severe fibrosis around both ureters. Histological examination confirmed the diagnosis of idiopathic retroperitoneal fibrosis. Presumably the suprasellar tumour was the first manifestation of retroperitoneal fibrosis. Once the diagnosis 'idiopathic retroperitoneal fibrosis' is confirmed, fibrotic manifestations and complications involving extra-retroperitoneal tissues including the endocrine system, should be sought.

Adult↗
PubMed2001

Efficacy of moxifloxacin, trovafloxacin, clinafloxacin and levofloxacin against intracellular Legionella pneumophila.

This study compares the in vitro activity of novel fluoroquinolones against clinical Legionella pneumophila isolates. We determined both the MICs and intracellular efficacy of moxifloxacin, trovafloxacin, clinafloxacin and levofloxacin in the Mono Mac 6 infection model. Six legionella strains were tested and all proved highly susceptible to the fluoroquinolones. Clinafloxacin and trovafloxacin were found to have the lowest MICs (0.004 mg/L) followed by levofloxacin and moxifloxacin (0.015-0.03 mg/L). In the Mono Mac 6 infection model, inhibition of L. pneumophila was achieved at concentrations four times below the respective in vitro MICs. Concentrations as low as 0.015 mg/L of moxifloxacin and levofloxacin, 0.004 mg/L of trovafloxacin and 0.002 mg/L of clinafloxacin markedly decreased viable intracellular bacterial counts. These data strongly support further clinical evaluation of new fluoroquinolones for empirical treatment of lower respiratory tract infection including atypical pneumonia caused by L. pneumophila.

Anti-Infective Agents↗
PubMed2000

Correlation between quantitative EMG and muscle MRI in patients with axonal neuropathy.

The aim of the study was to investigate whether there are correlations between electromyography (EMG) data and findings in muscle magnetic resonance imaging (MRI). Quantitative EMG data and the amount of pathologic spontaneous activity (PSA) were compared with MRI signal intensities of the tibialis anterior muscles of 20 patients with axonal polyneuropathy and 14 healthy subjects. Using hierarchical regression analysis, the mean motor unit action potential (MUAP) size index (SI) and the amount of PSA were accurate predictors of T1-weighted signal intensity in MRI, an expression of fatty degeneration. The MUAP SI was superior to MUAP amplitude in explaining the variance of T1 signal intensity. Age was not a relevant factor. A high correlation was found between the amount of PSA and the T2-weighted signal intensity in short tau inversion recovery sequence. Magnetic resonance imaging demonstrates the structural changes and thus visualizes the outcome of the functional changes of denervation and reinnervation detected by EMG.

Action Potentials↗
PubMed2000

The effect of azithromycin on intracellular Legionella pneumophila in the Mono Mac 6 cell line at serum concentrations attainable in vivo.

We investigated the antimicrobial efficacy of clinically meaningful, low concentrations of azithromycin against intracellular growth of two clinical isolates of Legionella pneumophila. The mature monocytic cell line Mono Mac 6 was used as a model to investigate the effects of antimicrobial agents on L. pneumophila. Extracellular susceptibility was determined by microdilution susceptibility testing in BYEalpha broth after 48 h of incubation. Mono Mac 6 cells infected with L. pneumophila were incubated with various concentrations of azithromycin. After 2 days of incubation, intracellular bacteria were released from the phagocytes and plated on to BCYEalpha agar. Addition of the intracellular-acting antibiotics azithromycin or ciprofloxacin at their MICs (0.5 and 0. 015 mg/L, respectively) resulted in a significant decrease in cfu, of up to approximately 1 log(10) after 48 h of incubation. In contrast, incubation of intraphagocytic L. pneumophila in the presence of antibiotics without intracellular activity (ceftizoxime, imipenem or amoxycillin-clavulanic acid) did not have any effect. Azithromycin inhibited intracellular replication at concentrations as low as 0.125 mg/L, approximately one-quarter of the extracellular MIC. The Mono Mac 6 cell line is a useful infection model for investigating the intracellular activity of antimicrobial agents in vitro. In accordance with clinical data and animal experiments, azithromycin and ciprofloxacin inhibited the intraphagocytic replication of L. pneumophila. In particular, azithromycin killed ingested legionellae in vitro at concentrations below the peak serum concentrations and below the MIC.

Anti-Bacterial Agents↗
PubMed2000

Multicenter evaluation of epidemiological typing of methicillin-resistant Staphylococcus aureus strains by repetitive-element PCR analysis. The European Study Group on Epidemiological Markers of the ESCMID.

Rapid and efficient epidemiologic typing systems would be useful to monitor transmission of methicillin-resistant Staphylococcus aureus (MRSA) at both local and interregional levels. To evaluate the intralaboratory performance and interlaboratory reproducibility of three recently developed repeat-element PCR (rep-PCR) methods for the typing of MRSA, 50 MRSA strains characterized by pulsed-field gel electrophoresis (PFGE) (SmaI) analysis and epidemiological data were blindly typed by inter-IS256, 16S-23S ribosomal DNA (rDNA), and MP3 PCR in 12 laboratories in eight countries using standard reagents and protocols. Performance of typing was defined by reproducibility (R), discriminatory power (D), and agreement with PFGE analysis. Interlaboratory reproducibility of pattern and type classification was assessed visually and using gel analysis software. Each typing method showed a different performance level in each center. In the center performing best with each method, inter-IS256 PCR typing achieved R = 100% and D = 100%; 16S-23S rDNA PCR, R = 100% and D = 82%; and MP3 PCR, R = 80% and D = 83%. Concordance between rep-PCR type and PFGE type ranged by center: 70 to 90% for inter-IS256 PCR, 44 to 57% for 16S-23S rDNA PCR, and 53 to 54% for MP3 PCR analysis. In conclusion, the performance of inter-IS256 PCR typing was similar to that of PFGE analysis in some but not all centers, whereas other rep-PCR protocols showed lower discrimination and intralaboratory reproducibility. None of these assays, however, was sufficiently reproducible for interlaboratory exchange of data.

Bacterial Typing Techniques↗
PubMed2000

Comparative evaluation of three different genotyping methods for investigation of nosocomial outbreaks of Legionnaires' disease in hospitals.

The increased incidence of nosocomial Legionnaires' disease in two hospitals prompted investigation of possible environmental sources. In the search for an effective DNA-typing technique for use in hospital epidemiology, the performance and convenience of three methods-SfiI macrorestriction analysis (MRA), amplified fragment length polymorphism (AFLP), and arbitrarily primed PCR (AP-PCR)-were compared. Twenty-nine outbreak-associated and eight nonassociated strains of Legionella pneumophila with 13 MRA types and subtypes were investigated. These strains comprised isolates from bronchoalveolar lavages, from environmental, patient-related sources, and type strains. All three typing methods detected one predominant genotype associated with the outbreaks in both hospitals. All of them correctly assigned epidemiologically associated, environmental isolates to their respective patient specimens. AP-PCR was the least discriminating and least reproducible technique. In contrast, AFLP was demonstrated as being the method with the best interassay reproducibility (90%) and concordance (94%) in comparison to the genotyping standard of MRA and the epidemiological data. Analysis of AFLP fragments revealed 12 different types and subtypes. Because of its simplicity and reproducibility, AFLP proved to be the most effective technique in outbreak investigation.

Bacterial Typing Techniques↗