Search PubMed⌕ Search

Biomedical subjects

F Meyer

Publications and source records attributed to F Meyer.

At least 55 records · Page 3Linked to original sources
PubMed2003

The 79,370-bp conjugative plasmid pB4 consists of an IncP-1beta backbone loaded with a chromate resistance transposon, the strA-strB streptomycin resistance gene pair, the oxacillinase gene bla(NPS-1), and a tripartite antibiotic efflux system of the resistance-nodulation-division family.

Plasmid pB4 is a conjugative antibiotic resistance plasmid, originally isolated from a microbial community growing in activated sludge, by means of an exogenous isolation method with Pseudomonas sp. B13 as recipient. We have determined the complete nucleotide sequence of pB4. The plasmid is 79,370 bp long and contains at least 81 complete coding regions. A suite of coding regions predicted to be involved in plasmid replication, plasmid maintenance, and conjugative transfer revealed significant similarity to the IncP-1beta backbone of R751. Four resistance gene regions comprising mobile genetic elements are inserted in the IncP-1beta backbone of pB4. The modular 'gene load' of pB4 includes (1) the novel transposon Tn 5719 containing genes characteristic of chromate resistance determinants, (2) the transposon Tn 5393c carrying the widespread streptomycin resistance gene pair strA-strB, (3) the beta-lactam antibiotic resistance gene bla(NPS-1) flanked by highly conserved sequences characteristic of integrons, and (4) a tripartite antibiotic resistance determinant comprising an efflux protein of the resistance-nodulation-division (RND) family, a periplasmic membrane fusion protein (MFP), and an outer membrane factor (OMF). The components of the RND-MFP-OMF efflux system showed the highest similarity to the products of the mexCD-oprJ determinant from the Pseudomonas aeruginosa chromosome. Functional analysis of the cloned resistance region from pB4 in Pseudomonas sp. B13 indicated that the RND-MFP-OMF efflux system conferred high-level resistance to erythromycin and roxithromycin resistance on the host strain. This is the first example of an RND-MFP-OMF-type antibiotic resistance determinant to be found in a plasmid genome. The global genetic organization of pB4 implies that its gene load might be disseminated between bacteria in different habitats by the combined action of the conjugation apparatus and the mobility of its component elements.

Bacterial Proteins↗
PubMed2003

Different mRNA expression profile during tumor progression in a well-differentiated liposarcoma--A microdissection approach.

Like malignant fibrous histiocytoma (MFH), dedifferentiated liposarcoma represents a distinct subtype of liposarcoma and is characterized by an abrupt transition from well-differentiated liposarcoma (WDL) to highgrade dedifferentiated liposarcoma (DDL) . In addition, specific cytogenetic aberrations support the close biological relationship between WDL and DDL. Recent observations indicated the significance of cell cycle aberrations in tumor progression from the low-malignant, well differentiated to its dedifferentiated form, the prognosis of which is poor. Thus, alterations of mdm2 and p53 genes belong to the most frequently reported alterations in these two subtypes of liposarcoma. In previous investigations, we reported that loss of heterozygosity at the Rb gene locus, telomerase activity, hTERT, and c-Myc expression were associated with tumor progression in liposarcomas. In this study, we report on a case of a WD/DDL, in which both tumor components were separated using laser microdissection (P.A.L.M.) for the investigation of hTERT mRNA expression on a LightCycler. Macroscopically selected and histologically proven cryosections of low malignant and highly malignant tumor areas were cytogenetically investigated to confirm the diagnosis and to find additional chromosomal alterations with tumor progression.

Aged↗
PubMed2003

Prenatal ultrasonographic diagnosis of a recurrent case of Johanson-Blizzard syndrome.

We report on ultrasonographic prenatal diagnosis of a recurrent case of Johanson-Blizzard syndrome. The pregnancy was terminated at 21 weeks'. This observation highlights the great variability of the expression of this syndrome, including in the same family, and the necessity of collaborating with an experienced geneticist in all antenatal diagnosis of any complex of abnormalities.

Abnormalities, Multiple↗
PubMed2002

[Experiences with ambulatory arteriovenous shunt surgery. A cost-benefit analysis].

Placement of arteriovenous (av) fistulas has been executed at the reporting surgical department for 3 years. Calculation of the reimbursement by the insurance companies is based on the so-called "Unique Evaluation Table" (Einheitlicher Bewertungsmassstab). The aim of the study was to evaluate the efficiency of the placement of av fistulas in an out-patient setting and the acceptance of this approach in the patients. The costs based on an average of the duration of the intervention and treatment at the out-patient clinic per time unit for surgeon, nurse and operating room, as well as costs for use of specific materials were listed, summarized, and compared with the amount of money which was reimbursed by the insurance companies according to the "Unique Evaluation Table". During the 3-year time period, 67 patients underwent 70 placements of av fistulas in an out-patient setting (in total, 532 interventions). Patients answered a questionnaire, and procedures were evaluated for average costs. Based on the table-dependent reimbursement of DM 274.00 (according to the "Unique Evaluation Table"), costs of DM 497.94 (DM 445.50 for 54 min of mean duration of surgical procedure plus DM 52.44 for materials) were determined, indicating that no full reimbursement was found despite the fact that there was only a minimal rate of early complications (thrombosis, n = 2 [3%]) (infection, n = 1 [1.5%]). The expenses were 81.7% on average above the level of the reimbursement. In conclusion, despite high acceptance of an out-patient setting for placement of av fistulas in patients (82%), it is not efficient from an economic point of view and can be only provided for specifically selected cases. Therefore, it is not advisable at present to place av fistulas at German out-patient clinics with no following admission of the patients, to avoid financial disadvantages for the surgical department. New negotiations between the medical profession and the insurance companies are urgently needed to ensure an improved financial outcome for the clinics.

Ambulatory Surgical Procedures↗
PubMed2002

[Pneumoperitoneum as occasional finding in chronic dialysis patients--laparotomy or conservative non-operative approach?].

Free air of unknown origin within the abdominal cavity is a serious problem, which in the majority of cases indicates the perforation of a hollow organ. In two cases, we report on i) detection of free air subdiaphragmatically by coincidence during follow-up investigation of an interstitial pulmonary disease (chest X-ray) in a 67-year old patient with chronic renal insufficiency, and ii) diagnostic of pneumoperitoneum (3 times as primary diagnosis) in a 63-year old multimorbid female (with chronic renal insufficiency) with recurrent, but unspecific epigastric symptoms over a time period of 5 years. The following investigations such as endoscopy, contrast enema, and abdominal ultrasound did not detect a perforation as most likely cause. The first patient was discharged after clinical observation, laboratory and ultrasound follow-up for 5 days. In the second case, neither explorative laparoscopy during the second clinical observation period nor laparotomy for required cholecystectomy because of cholecystitis could appropriately clarify the origin. In conclusion, the detection of a pneumoperitoneum in asymptomatic patients or subjects with unspecific abdominal symptoms requires always clinical monitoring and instrumental diagnostic, consisting of endoscopy in the upper gastrointestinal tract, contrast enema of the colon and abdominal and/or thoracal computed tomography, to definitely exclude perforation. In addition, ultrasound as third column detects early low amounts of fluid and is the suitable method for short-term follow-up. The cause of pneumoperitoneum, particularly in asymptomatic patients, can not be found in every case. Under these circumstances, non-operative treatment is favored.

Aged↗
PubMed2002

[Fistula Banding - Success-promoting Approach in Peripheral Steal Syndrome].

AIM: Evaluation of the diagnostic and therapeutic management of peripheral steal syndrome after placement of an autologous arteriovenous (av-) fistula and presentation of treatment results after its surgical correction. METHODS: During a time period from 1994 to 1999, 1 253 av-fistulas for hemodialysis were placed in our surgical department. Twenty-one patients (1.68 %) underwent service operations because of considerable lower perfusion of the hand. In 14 patients the av-fistula was ligated, whereas in 7 patients, a polytetrafluorethylene (PTFE) sleeve was implanted at the venous site for fistula "banding" to diminish blood flow. In addition to the clinical finding, pre-, intra- and postoperative blood flow rates were determined using Duplex ultrasonography. RESULTS: In patients showing flow rates of < 250 ml (carefully disclosed empiric value) ligation was chosen, whereas in cases with distinctly increased flow rates, banding of the arterialized vein was performed (authors' individually selected borderline flow). The extension of the banding was specified according to the intraoperatively determined flow rates. Recurrent steal syndrome was not observed over the entire postoperative observation period of 1-3 years. CONCLUSION: Arterial steal syndrome is a rare complication after placement of an av-fistula. In the majority of cases, surgical therapy is necessary. Pre- and intraoperative analysis of flow rates using Duplex ultrasonography may help to select the appropriate surgical approach and may, thus, determine the success rate of service operation.

Adult↗
PubMed2002

Immunomodulation by perioperative administration of n-3 fatty acids.

It has been increasingly reported that administration of n-3 fatty acids is beneficial in patients with inflammatory processes. This effect is most likely caused by different biological characteristics, including an immunomodulating effect of the products derived from n-3 fatty acids through eicosanoid metabolism. The aim of this study was to investigate the effect of perioperative administration of n-3 fatty acids on inflammatory and immune responses as well as on the postoperative course of patients with extended surgical interventions of the abdomen. In particular, the effect of n-3 fatty acids on interleukin-6 release and on granulocyte/monocyte function (HLA-DR expression) was studied. There was a downregulation of the inflammatory response, and, simultaneously, a smaller postoperative immune suppression in the n-3 fatty acid group. In addition, we observed shorter postoperative periods in the intensive care unit and on the regular medical wards as well as lower rates of severe infections. The results suggest that perioperative administration of n-3 fatty acids may have a favourable effect on outcome in patients with severe surgical interventions by lowering the magnitude of inflammatory response and by modulating the immune response.

Abdomen↗
PubMed2002

Clinical findings in patients presenting with sore throat. A study on inter-observer reliability.

BACKGROUND: Several clinical prediction scores have been developed to help practitioners assess the probability of streptococcal throat infection. Prior to this study, it was not known how reliably doctors assess the signs that contribute to these decision aids. OBJECTIVE: The aim of this study was to measure the inter-observer reliability of clinical findings related to sore throat. METHODS: Consecutive patients presenting with sore throat in five primary care practices in Germany took part (n = 126). Each patient was assessed independently by two doctors with regard to lymph nodes, pharynx, soft palate and tonsils. RESULTS: Agreement among practitioners was not satisfactory. CONCLUSIONS: Results suggest that the performance of clinical scoring systems can be improved by training on how to elicit relevant clinical signs. Our findings cast some doubt on the effectiveness of under- and post-graduate training in this area.

Child, Preschool↗
PubMed2001

Extremely bent cyanide coordination at a preorganized dinickel site and assembly of a starlike nonanuclear complex from the constrained dinickel building blocks.

An extremely bent cyanide coordination at a dinickel scaffold is reported. Preorganization of two nickel ions is achieved by means of a compartmental dinucleating pyrazolate ligand L(-), setting up a bimetallic coordination pocket with constrained metal-metal separation. The mixed-spin dinickel(II) complex [LNi2(CN)(MeCN)](ClO4)2 (1) has been characterized by X-ray diffraction. The MeCN bound to the high-spin nickel(II) ion can be removed or replaced by other ligands, e.g., by the cyanide ligand of a tetracyanonickelate(II) moiety to give the starlike nonanuclear complex ([LNi2(CN)]4[Ni(CN)4])(ClO4)6 (2) that contains four of the constrained pyrazolate-based dinickel(II) fragments grouped around a central tetracyanonickelate(II) unit, as revealed by X-ray crystallography. Spectral and electrochemical properties of 1 and 2 are reported, and the formation of reduced mixed-valent Ni(I)Ni(II) species is investigated by IR and UV/vis spectroelectrochemistry.

Journal Article↗
PubMed2001

Expression of p21 predicts PSA failure in locally advanced prostate cancer treated by prostatectomy.

The management of prostate cancer is based on several clinicopathological criteria. The ability to determine the tumor's biological potential is one goal of tumor markers in order to identify patients who may require more intensive treatment strategies. The purpose of our study was to determine if p21/(WAF1/CIP1) expression can predict biochemical failure in patients with locally advanced prostate cancer treated by radical retropubic prostatectomy (RRP). We used immunohistochemistry to analyze patterns of p21 expression in a population of 296 patients with locally advanced (pT3) prostate cancer treated by RRP. Results were correlated with clinicopathological parameters and time to PSA failure. For the entire cohort of 296 patients, after adjustment for prognostic factors, p21 expression was associated with an increased risk of PSA failure (relative risk [RR] = 1.48) of statistical significance at a median follow-up of 54.5 months. Other parameters that independently predicted the risk of PSA failure included lymph node metastasis and seminal vesicle involvement. Because neoadjuvant hormonal therapy (NHT) is known to lead to involutional changes in prostatic carcinoma, we performed multivariate analyses after stratifying for NHT prior to surgery. Among the 172 patients treated by RRP alone, p21 expression was an independent predictor of PSA failure (RR = 2.30), as were lymph node metastases (RR = 3.19) and pathological grade 5-7 and 8-10 (RR = 2.87 and 3.50, respectively). p21 over-expression is an independent predictor of PSA failure in pT3 patients treated by radical prostatectomy, especially if they did not receive NHT. This tumor marker may help clinicians identify patients who may require adjuvant treatment strategies following radical prostatectomy.

Aged↗
PubMed2001

[Value of cytokeratin and Ca 19-9 antigen in immunohistological detection of disseminated tumor cells in lymph nodes in pancreas carcinoma].

INTRODUCTION: Based on the fact that pancreatic carcinoma is still associated with poor outcome, the aim of the study was to determine frequency of early tumor cell dissemination using immunohistology in lymph nodes classified as tumor-free by conventional histopathology. METHODS: Fifteen patients with ductal pancreatic carcinoma and 10 patients with carcinoma of the papilla of Vater underwent radical tumor resection (resection status R0, tumor staging pTxpN0M0). In total, 229 lymph nodes classified as tumor-free by histopathology were investigated for disseminated tumor cells using antibodies against cytokeratin and CA19-9. As control, 81 lymph nodes obtained from patients with chronic pancreatitis were analyzed. RESULTS: In 55 of 229 lymph nodes (26.3%), cytokeratin-positive, disseminated tumor cells were detected. Cytokeratin-positive cells were found in at least one resected lymph node of each patient with ductal carcinoma of the pancreatic head (100%), whereas in patients with carcinoma of the papilla of Vater, no disseminated tumor cells were detected using the antibody against cytokeratin. Similarly, there was no detection of tumor cells (false-positive) in patients with chronic pancreatitis. In contrast, CA19-9 antigen was detectable in resected lymph nodes of each of the 25 carcinoma patients (pancreatic carcinoma and carcinoma of the papilla of Vater). Interestingly, 52 of 81 lymph nodes (64.2%) from the control group (chronic pancreatitis) were false-positive. CONCLUSION: Detection of disseminated tumor cells in lymph nodes using an antibody against cytokeratin is specific and suitable while use of an antibody against CA19-9 is not recommendable because of the high rate of false-positive results. The results may indicate that ductal pancreatic carcinoma generates early dissemination of tumor cells into lymph nodes. This may be one explanation for the poor outcome of this carcinoma compared with that of the carcinoma of the papilla of Vater (14 versus 48 months P < 0.05).

Adenocarcinoma↗
PubMed2001

Ectopic vascularization of the right kidney by a contralateral origin of the main renal artery from the left common iliac artery: report of a case.

In daily practice, an atypical renal blood supply is a rare finding. An ectopic origin of the right main renal artery from the contralateral common iliac artery was observed when angiography was performed to diagnose irregularities in perfusion of the lower extremities and to determine the necessity for vascular surgical intervention in a 66-year-old man. Conservative treatment was successful in this patient, who suffered from intermittent claudication because of an obstruction of the superficial femoral arteries. The diagnostic approach with angiography is considered to be essential for revealing such anomalies. Conventional vascular surgical reconstruction would have threatened the perfusion of the right kidney in this case.

Aged↗
PubMed2001

Duration of neoadjuvant androgen deprivation therapy before radical prostatectomy and disease-free survival in men with prostate cancer.

There is little evidence that neoadjuvant androgen deprivation therapy (ADT) of 3 months' duration before radical prostatectomy (RP) favorably influences disease-free survival. However, recent data suggest that prolonged treatment may improve outcome. We conducted a prospective cohort study to determine whether ADT of either standard or prolonged duration before RP influences the risk of prostate-specific antigen (PSA) failure. We followed 756 men treated for prostate cancer by RP between 1991 and 1998 in Quebec City. Of these, 240 received combined neoadjuvant ADT for either </=92 days (129 men) or >/=93 days (111 men), and 516 were treated by RP alone. Multivariate Cox regression was used to estimate the hazard ratios (HR) of PSA failure (>0.3 ng/mL) associated with treatment regimen controlling for age, clinical stage, grade, and initial PSA level. The median duration of follow-up was 4 years. Compared with men treated by RP alone, those who received neoadjuvant ADT for >/=93 days had an HR of PSA failure of 0.60. The inverse association with the risk of PSA failure became statistically significant from the third year on, reached its greatest magnitude after 4 years, and was still present 8 years after RP. No association was observed for ADT of </=92 days. These results suggest that neoadjuvant ADT before RP has a real, delayed, and persistent effect on disease-free survival, if and only if ADT is prolonged beyond 3 months.

Androgen Antagonists↗