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Biomedical subjects

R Eberhardt

Publications and source records attributed to R Eberhardt.

At least 19 recordsLinked to original sources
PubMed2007

Actual role of endobronchial ultrasound (EBUS).

Many pathologies of the airway involve the bronchial wall and the parabronchial structures. The view of the endoscopist, however, is limited to the lumen and the internal surface of the airway. Processes within the airway wall and outside the airway can only be assessed by indirect signs. Especially in malignancies, this can be of decisive importance for the fate of the patient. Therefore, expanding the endoscopist's view beyond the airway is essential. Endobronchial ultrasound (EBUS) and endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) are new diagnostic tools that are available on the market. They have great potential for diagnosis of mediastinal processes and staging of lung cancer. After discovering a lung cancer without extrathoracic metastases, the preoperative mediastinal check-up is of great importance in determining operability. The investigation of a suspected malignant adenopathy justifies a complete examination by mediastinoscopy or mediastinotomy, which are considered gold standards. EBUS-TBNA constitutes the recent evolution of TBNA, a method known for 20 years now but underused. The aim of this review is to highlight to the different techniques and to discuss the results of published trials.

Biopsy, Fine-Needle↗
PubMed2006

Endobronchial ultrasound-guided transbronchial needle aspiration of lymph nodes in the radiologically normal mediastinum.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can sample enlarged mediastinal lymph nodes in patients with nonsmall cell lung cancer (NSCLC). To date, EBUS-TBNA has only been used to sample nodes visible on computed tomography (CT). The aim of the present study was to determine the accuracy of EBUS-TBNA in sampling nodes 1 cm) in the mediastinum underwent EBUS-TBNA. Identifiable lymph nodes at locations 2r, 2l, 4r, 4l, 7, 10r, 10l, 11r and 11l were aspirated. All patients underwent subsequent surgical staging. Diagnoses based on aspiration results were compared with those based on surgical results. In 100 patients (mean age 58.9 yrs; 68 males), 119 lymph nodes ranging 5-10 mm in size were detected and sampled. Malignancy was detected in 19 patients but missed in two; all diagnoses were confirmed by surgical findings. The mean diameter of the punctured lymph nodes was 8.1 mm. The sensitivity of EBUS-TBNA for detecting malignancy was 92.3%, specificity was 100%, and the negative predictive value was 96.3%. No complications occurred. In conclusion, endobronchial ultrasound-guided transbronchial needle aspiration can accurately sample even small mediastinal nodes, therefore avoiding unnecessary surgical exploration in one out of six patients who have no computed tomography evidence of mediastinal disease. Potentially operable patients with no signs of mediastinal involvement on computed tomography may benefit from pre-surgical endobronchial ultrasound-guided transbronchial needle aspiration and staging.

Biopsy, Fine-Needle↗
PubMed2006

Real-time endobronchial ultrasound guided transbronchial needle aspiration for sampling mediastinal lymph nodes.

BACKGROUND: Transbronchial needle aspiration (TBNA) is an established method for sampling mediastinal lymph nodes to aid in diagnosing lymphadenopathy and in staging lung cancers. Real-time endobronchial ultrasound (EBUS) guidance is a new method of TBNA that may increase the ability to sample these nodes and hence to determine a diagnosis. A descriptive study was conducted to test this new method. METHODS: Consecutive patients referred for TBNA of mediastinal lymph nodes were included in the trial. When a node was detected, a puncture was performed under real-time ultrasound control. The primary end point was the number of successful biopsy specimens. Diagnostic results from the biopsies were compared with operative findings. Lymph node stations were classified according to the recently adopted American Thoracic Society scheme. RESULTS: From 502 patients (316 men) of mean age 59 years (range 24-82), 572 lymph nodes were punctured and 535 (94%) resulted in a diagnosis. Biopsy specimens were taken from lymph nodes in region 2L (40 nodes), 2R (53 nodes), 3 (35 nodes), 4R (86 nodes), 4L (77 nodes), 7 (127 nodes), 10R (38 nodes), 10L (43 nodes), 11R (40 nodes) and 11L (33 nodes). The mean (SD) diameter of the nodes was 1.6 (0.36) cm and the range was 0.8-3.2 cm (SD range 0.8-4.3). Sensitivity was 94%, specificity 100%, and the positive predictive value was 100% calculated per patient. No complications occurred. CONCLUSION: EBUS-TBNA is a promising new method for sampling mediastinal lymph nodes. It appears to permit more and smaller nodes to be sampled than conventional TBNA, and it is safe.

Adult↗
PubMed2006

[MRI in staging of lung cancer].

PURPOSE: Overview of magnetic resonance imaging (MRI) in staging of lung cancer. MATERIAL AND METHODS: Currently available methods of imaging lung cancer, lymph node and distant metastases by MRI are explained. At present, MRI is mainly used in the detection of cerebral metastases and assessment of infiltration of the thoracic wall and of the mediastinum. The capabilities of T2-weighted single-shot TSE (HASTE) and T1-weighted 3D gradient echo techniques (VIBE) are demonstrated. RESULTS: With the advent of new fast sequences like HASTE and VIBE the spatial resolution comes close to that of computed tomography but with an outstanding soft tissue contrast and without radiation exposure. The introduction of lymph node specific contrast media will improve sensitivity and specificity in N staging. Additionally, whole-body MRI is capable of detecting distant metastases, in particular in the organs at risk, i.e. brain, upper abdomen and musculoskeletal system. CONCLUSION: MRI is gaining importance as part of a multimodal imaging approach for staging of lung cancer.

Humans↗
PubMed2006

[Endosonography in diagnosis and staging of lung cancer].

Today endosonography in form of endobronchial (EBUS) and endoesophageal ultrasound (EUS) is a routine adjunct to endoscopy in many pulmonary centers. Three different techniques are available and can improve the diagnosing and staging in patients with lung cancer. The clinical application and the diagnostic benefit have been established in a lot of studies compared with conventional radiologic methods and other diagnostic procedures. The role of endosonography is expected to grow in the near future as an important tool. Especially the approaches with EUS-fine needle aspiration (EUS-FNA) and/or EBUS controlled transbronchial needle aspiration (EBUS-TBNA) may be able to replace more invasive methods like mediastinoscopy for evaluating patients with lung cancer.

Echocardiography, Transesophageal↗
PubMed2006

Endobronchial ultrasound-guided transbronchial lung biopsy in fluoroscopically invisible solitary pulmonary nodules: a prospective trial.

STUDY OBJECTIVES: Transbronchial biopsy (TBBX) for solitary pulmonary nodules (SPNs) is usually performed under fluoroscopic guidance, but the diagnostic yield depends on lesion size and varies widely. Nodules < 3 cm frequently cannot be visualized fluoroscopically. An alternative guidance technique, endobronchial ultrasound (EBUS), also allows visualization of pulmonary nodules. This study assessed the diagnostic yield of EBUS-guided TBBX in fluoroscopically invisible SPNs. DESIGN: The study was a prospective trial using a crossover design. PATIENTS AND METHODS: All patients with SPNs and indications for bronchoscopy were included in the study. An EBUS-guided examination was performed in patients with fluoroscopically invisible nodules. The EBUS probe was introduced through a guide catheter into the presumed segment. If a typical ultrasonic picture of solid tissue could be seen, the probe was removed and the catheter left in place. The biopsy forceps were introduced and specimens taken. RESULTS: One hundred thirty-eight consecutive patients with SPNs were examined. Of those, 54 patients presented with SPNs that could not be visualized with fluoroscopy. The mean diameter of the nodules was 2.2 cm. In 48 patients (89%), the lesion was localized with EBUS, and in 38 patients (70%) the biopsy established the diagnosis. The 16 patients with undiagnosed SPNs were referred for surgical biopsy; 10 of those lesions were malignant and 6 were benign. The diagnosis in nine patients (17%) saved the patients from having to undergo a surgical procedure. The only complication was a pneumothorax in one patient. CONCLUSIONS: EBUS-guided TBBX is a safe and very effective method for SPNs that cannot be visualized by fluoroscopy. The procedure may increase the yield of endoscopic biopsy in patients with these nodules and avert the need for surgical procedures.

Adult↗
PubMed2005

[Therapy for overactive detrusor using propiverine].

BACKGROUND: Our aim was to evaluate the efficacy and tolerability of propiverine hydrochloride (propiverine) in daily practice and to check the risk-benefit relation using previously collected data on 4,390 patients. PATIENTS AND METHODS: A total of 2,932 patients with symptoms of overactive bladder were treated with propiverine over a period of 12 weeks using a multicentre post marketing surveillance. At three visits (inclusion, after 4 weeks, after 12 weeks), parameters from the micturition diary (incontinence episodes, frequency of micturition, micturition volume) were recorded. RESULTS: The number of incontinence episodes during daytime decreased during therapy from 3.6+/-3.8 to 1.2+/-2.3. The number of episodes at night decreased from 1.5+/-2.1 to 0.4+/-0.8 (both P<0.001). The mean volume per micturition improved during therapy (from 142.7 ml to 213.3 ml; +49.5%; P<0.0001). Some 85% of the investigators judged the efficacy of propiverine to be good or very good, 2.1% as not sufficient. The most frequent adverse event was dry mouth (17.3% of the patients after 12 weeks) mostly with low severity. More than 70% of the patients reported good or very good tolerability. Only 0.6% of the patients reported insufficient tolerability.

Adolescent↗
PubMed2004

[Endobronchial ultrasound in bronchial carcinoma].

Conventional imaging procedures proved to be insufficient for staging of lung cancer especially with respect of N-stage, infiltration of mediastinal structures and early lung cancer. As also the view of the endoscopist is restricted we developed the new method of endobronchial ultrasonography (EBUS) as adjunct to conventional bronchoscopy. The initial technical problems were solved by development of a balloon catheter for application of miniaturized 20 MHz probes. EBUS is a new technology that can be easily applied and is well tolerated. It improves the results of bronchoscopy in addition to conventional diagnostic procedures. Further developments will be made in future to improve the application of ultrasound in chest medicine.

Carcinoma, Bronchogenic↗
PubMed2002

Traceability of pH measurements by glass electrode cells: performance characteristic of pH electrodes by multi-point calibration.

Routine pH measurements are carried out with pH meter-glass electrode assemblies. In most cases the glass and reference electrodes are thereby fashioned into a single probe, the so-called 'combination electrode' or simply 'the pH electrode'. The use of these electrodes is subject to various effects, described below, producing uncertainties of unknown magnitude. Therefore, the measurement of pH of a sample requires a suitable calibration by certified standard buffer solutions (CRMs) traceable to primary pH standards. The procedures in use are based on calibrations at one point, at two points bracketing the sample pH and at a series of points, the so-called multi-point calibration. The multi-point calibration (MPC) is recommended if minimum uncertainty and maximum consistency are required over a wide range of unknown pH values. Details of uncertainty computations for the two-point and MPC procedure are given. Furthermore, the multi-point calibration is a useful tool to characterise the performance of pH electrodes. This is demonstrated with different commercial pH electrodes. ELECTRONIC SUPPLEMENTARY MATERIAL is available if you access this article at http://dx.doi.org/10.1007/s00216-002-1506-5. On that page (frame on the left side), a link takes you directly to the supplementary material.

Journal Article↗
PubMed2000

Polymer production by two newly isolated extremely halophilic archaea: application of a novel corrosion-resistant bioreactor.

A novel corrosion-resistant bioreactor composed of polyetherether ketone (PEEK), tech glass and silicium nitrite ceramics was constructed and applied for the cultivation of two newly isolated, extremely halophilic archaea producing poly(gamma-glutamic acid) (PGA), or poly(beta-hydroxy butyric acid) (PHB), respectively. These bacteria were isolated from hypersaline soil close to Aswan (Egypt). The isolate strain 40, which is related to the genus Natrialba, produced large amounts of PGA when cultivated on solid medium. Culture conditions were optimised applying the corrosion-resistant bioreactor. PGA production was dependent on NaCl concentration and occurred about at 20% (w/v) NaCl in the medium. A maximum cell density of about 1.6 g cell dry matter/l was obtained when the bioreactor was stirred and aerated in a batch fermentation process using proteose-peptone medium. The supernatant was monitored with respect to PGA formation, and after 90 h a maximum of 470 mg/l culture volume was detected by HPLC analysis. Culture conditions were optimized for the isolate 56, which accumulated PHB as intracellular granules. Batch fermentations in the stirred and aerated bioreactor applying acetate and n-butyric acid as carbon sources led to cell density of 2.28 g cell dry matter/l and a maximum PHB accumulation contributing to about 53% of cellular dry weight. About 4.6 g PHB were isolated from 10.6 g dried cells of strain 56, which exhibited a weight average molar mass of 2.3 x 10(5) g mol(-1) and a polydispersity of about 1.4.

Archaea↗
PubMed2000

Radiographic findings in osteoarthritis of the knee joint are not correlated with cartilage histomorphology or immunohistochemistry.

The purpose of this study was to investigate whether radiographic joint space narrowing (JSN) of the lateral knee compartment predicts the histomorphological or immunhistochemical grading in cases of osteoarthritis of the knee joint. The lateral joint space was measured on weight-bearing radiographs. Femoral osteochondral plugs of 29 patients undergoing total knee replacement were obtained from lateral condyles. All these patients had severe osteoarthritis of the medial compartment, with the lateral compartment showing different stages of osteoarthritis. The specimens were histomorphologically evaluated with the Mankin score, and the expression of the cartilage-degrading enzymes MMP1 and MMP3 was measured. There was no correlation between the joint space and histomorphological or immunohistochemical data, whereas the enzyme expression was correlated with histomorphological grading. We conclude that radiographic assessment alone is not sufficient to evaluate the cartilage damage of the lateral condyle.

Arthroplasty, Replacement, Knee↗
PubMed2000

Expression of stromelysin and urokinase type plasminogen activator protein in resection specimens and biopsies at different stages of osteoarthritis of the knee.

This study aimed at assessing the possible diagnostic value of cartilage biopsies as a convenient marker for cartilage matrix degradation. We therefore examined cartilage specimens from 56 patients with primary osteoarthritis (OA) of the knee. Resection and biopsy cartilage specimens obtained during joint replacement surgery were used for this study. In addition to histomorphology, immunohistochemistry (ICH) was performed to determine the expression levels and distribution patterns of stromelysin and u-PA protein. The latter data were compared with the degree of histomorphological changes in osteoarthritic cartilage samples, based on a modified version of Mankin's grading score. Compared to the cartilage resection specimens, the biopsies showed comparable expression patterns for both proteinases: the strongest signals were noted in the superficial zone and, as matrix destruction increased, also in the chondrocytes of the transition and deep zones. The strongest signals were ascertained in cell clusters beneath deep matrix fissures. At the immunohistochemical level, we found a direct correlation in the expression of MMP-3 and u-PA between resection specimens and biopsies. Furthermore, in both types of cartilage samples, we noticed a positive relationship between the expression of both proteins and the Mankin score. Analysis of the expression levels revealed significant differences between deep, transition and superficial zones. Histomorphological and immunohistochemical examinations of MMP-3 and u-PA in biopsies of osteoarthritic cartilage turned out to be useful for estimating the pathological changes within osteoarthritic knee joints. Therefore, in future, cartilage biopsies from osteoarthritic knee joints might serve as a diagnostic tool and thus have an influence on further therapeutic strategies.

Biopsy↗
PubMed1999

[Deterioration of sensory joint innervation as an enabling factor for development of arthrosis. An animal experiment study of the rat model].

In the present study we investigated the influence of an altered sensible joint innervation on the development of knee osteoarthritis in a wistar rat model of osteoarthritis. Capsaicin (8-methyl-N-vanillyl-6-noneamide) mediated partial sensible knee joint denervation was performed in a group of 16 male wistar rats. Twelve rats without alterations of the sensible knee joint innervation served as controls. In both groups, half of the rats underwent strenuous running exercises (total running load of 20 km) in a running wheel by intracranial self-stimulation, while the other half did not have any running load. In rats without running, there were no histological sings of knee osteoarthritis according to the Mankin score. In contrast, in rats running a total of 20 km significant osteoarthritis changes were observed. Hereby, in rats without altered sensible knee joint innervation, osteoarthritis was mostly classified as mild or moderate, while severe osteoarthritis was the predominant finding in the knee joints of the rats with partial sensible knee joint denervation. In conclusion, our study gives strong evidence for the hypothesis that an altered sensible joint innervation works as a contributing factor in the development of osteoarthritis.

Animals↗
PubMed1999

[New findings in orthopedic pathology].

The term orthopedic pathology refers to bone- and joint-affecting diseases which are important for the orthopedic surgeon. In the report presented here, emphasis is placed on the membrane-associated proteolysis, which is essential for the degradation of the extracellular matrix. Matrix-degrading processes play a role not only in arthrosis but also in rheumatoid arthritis. Moreover, they are strongly associated with the problem of loosening of protheses, which is of utmost importance for the orthopedic surgeon. In these processes, major roles are played by the plasminogen activator system, plasmin, different matrix metalloproteinases, including the membrane type matrix metalloproteases and different cathepsins. A deeper insight into the function of these proteins and their influence on the matrix degradation in joint diseases will open the way for new diagnostic and therapeutic strategies. Investigations into a large number of chondrosarcomas have shown that for this type of bone lesions, urokinase plasminogen activator and cathepsin B are prognostic parameters that are independent of the differentiation grade. Also, in this context, investigations into the membrane-bound proteases will be of great practical and diagnostic value.

Arthroplasty, Replacement↗
PubMed1998

Ceramic coagulation tip for interstitial thermoablation of the prostate: first experiments.

A direct electrically heated ceramic coagulation tip for interstitial thermoablation has been developed. Both the coagulation tip and a laser system (Medilas 4060) were tested in vitro to compare their efficacies. We have obtained coagulation necroses of similar sizes. The electrical coagulation tip as opposed to laser coagulation is a new therapeutic option for the therapy of high risk patients with symptomatic benign prostatic hyperplasia. Because of the materials used and the principle of heating involved, certain economic and safety advantages over the laser system are offered.

Animals↗
PubMed1998

Development of osteoarthritis in the knee joints of Wistar rats after strenuous running exercise in a running wheel by intracranial self-stimulation.

The influence of excessive running load on the development of knee osteoarthritis (OA) was investigated in male Wistar rats. Running exercises were performed in a running wheel using intracranial self-stimulation to motivate Wistar rats to run daily distances of 500 m at 5 days/week. Hereby, ten rats ran a distance of 15 km within three weeks while a further ten rats run a total of 30 km within six weeks. Thirteen Wistar rats without running exercises served as controls. Complete knee joint sections of all rats were evaluated histologically using MANKINs grading system with categorization of the findings into non, mild moderate, and severe osteoarthritis. In addition, immunoreactivity of the chondrocytes to MMP-3 as an important cartilage degrading enzyme in OA was assessed by immunostaining with monoclonal MMP-3 IgG antibodies. Histological assessment of the knee joint sections revealed a significant increase in osteoarthritic changes with higher running load. While in rats with 15 km running all but two knee joints showed mild OA, moderate OA was the predominant finding in rats with 30 km running. In contrast, no OA was found in the controls. Immunostaining for MMP-3 revealed a significant increase in immunoreactivity of the chondrocytes to MMP-3 with higher running load, indicating a running load-depending production of this cartilage-degrading enzyme in the course of increasing OA. Compared to 47.4% immunoreactive chondrocytes to MMP-3 in the controls, this ratio rose to 70.4% in rats with 15 km running and even up to 89.9% in rats with 30 km running. In conclusion, in Wistar rats, excessive running load leads to marked, running distance-depending osteoarthritic changes which are caused, at least in part, by an increase in MMP-3 production rising with greater running distance. Within this exercise model of OA, intracranial self-stimulation is an effective method to motivate Wistar rats to extremely excessive running in a running wheel. This model offers a wide range of further approaches to studying different processes of the development of OA.

Animals↗
PubMed1997

Treatment of osteochondritis dissecans of the talus: use of the mosaicplasty technique--a preliminary report.

A one-stage autogenous osteochondral grafting technique for the treatment of talar dome osteochondritis dissecans is described. Eleven patients with osteochondritis dissecans lesions, 10 mm or greater in diameter, were operated on using the mosaicplasty autogenous osteochondral transplantation technique. Osteochondral cylindrical grafts from the ipsilateral knee were delivered into the talar defect using specially designed tube chisels. These procedures were done by arthrotomy. With follow-up of 12 to 28 months (mean, 16 months), the patients returned to full activities and the results, using the Hannover scoring system, have been excellent.

Adolescent↗