Biomedical subjects

R Braunschweig

Publications and source records attributed to R Braunschweig.

At least 19 recordsLinked to original sources

PubMed2006

Alterations of the Wnt signaling pathway during the neoplastic progression of Barrett's esophagus.

Aberrant activation of the Wnt signaling pathway has been reported during neoplastic progression in Barrett's esophagus (BE). However, mutations in APC and CTNNB1 genes were rarely observed. In this study, expression pattern of Wnt ligands, Frizzled receptors and APC, as well as the methylation status of the APC, SFRP1 and SFRP2 promoter genes were investigated in normal esophageal mucosa and in preneoplastic and neoplastic lesions of BE patients. Promoter methylation of APC was found in all BE samples and in 95% of esophageal adenocarcinomas (EAC). Full methylation of APC correlated with lack of expression. In EAC, nuclear translocation of beta-catenin was observed regardless of the expression of APC. WNT2 expression was higher in dysplasia and EAC than in BE, with 20/26 (77%) of the EAC showing high expression of WNT2. SFRP1 methylation occurred in all BE samples and in 96% of EAC, while SFRP2 was methylated in 73% of the normal squamous esophageal mucosa samples. In conclusion, (1) alterations of key regulators of the Wnt signaling are frequent in the pathogenesis of BE; (2) the APC and SFRP1 genes are inactivated by promoter methylation in BE; (3) the WNT2 gene is upregulated along the progression from low-grade dysplasia to EAC.

Adenocarcinoma↗

PubMed2005

[Comments on the standards for acceptance and consistency testing of systems for digital radiography].

Due to German regulations, acceptance and consistency tests have to be obtained by 12.31.2005 for all equipment used for computed radiography according to special standards published in DIN 6868. This article familiarizes all users with the most important aspects of these standards. In addition, explanatory and background information for establishing these regulations are provided.

Artifacts↗

PubMed2005

[Emergency room management of multiple injured patients. A multislice computed tomography orientated treatment algorithm].

INTRODUCTION: In the treatment of the seriously injured patient, time is crucial. Clarke et al. showed that in the hypotensive patient with blunt abdominal trauma and bleeding a delay in the surgical treatment over 90 min increases mortality of 1 % every 3 minutes. So called trauma algorithms are used as systematic approach to the seriously injured patient that can be easily reviewed and practiced. One impact of this algorithm is to shorten time in the emergency room and may improve outcome of the patient. The patient outcome is directly related to the length of time between the injury and the beginning to proper definitive care. OBJECTIVE: Are improvements still necessary and possible in the care of the seriously injured patient? New technical developments like multislice-CT are able to shorten time until definitive care. The practicability of an multislice-CT orientated treatment algorithm was evaluated. METHODS: After integration of an multislice-CT into the emergency room the treatment of the seriously injured patient (ISS >16) was changed. Therefore an algorithm which puts the CT diagnostics in the first minutes of the clinical care was developed. RESULTS: 50 patients were treated following the new algorithm. The time in the emergency room decreased from 87 min to 36 min. CONCLUSION: This algorithm requires a differing from previous surgical standards, but it proved to be timesaving, effective and practicable. It makes the beginning of the definitive care possible within the first 40 min after patient arrival in the emergency room.

Algorithms↗

PubMed2005

Digital image DNA cytometry: a useful tool for the evaluation of malignancy in biliary strictures.

BACKGROUND: Cytologic evaluation of the biliary tract strictures is nowadays widely used for distinguishing between benign and malignant lesions but remains a challenge for some problematic cases. Digital Image cytometry (DNA-cytometry) helps cytopathologists to resolve some unclear situations. METHODS: We have analysed 41 specimens of bile duct brushings obtained from patients during ERCP (11 benign cases, 7 suspicious for malignancy cases and 23 malignant cases) by DNA-cytometry and correlated them with the histological biopsy counterpart. RESULTS: All eleven cytological and histological benign cases were DNA-diploid and among 22 patients with malignant cytological and histological diagnosis 21 were DNA-aneuploid. One case considered malignant by the cytopathologist revealed DNA-aneuploid but malignancy could not be confirmed by histology. The analysis of the suspicious for malignancy cases revealed that all DNA-aneuploid cases were malignant and all DNA-diploid cases were benign referring to the follow-up of the patients. The comparison between cytology alone and cytology combined with DNA-cytometry related to the histological diagnosis (gold standard) resulted in a sensitivity of 100% and a specificity of 79% for cytology alone; a specificity of 94% and a sensitivity 92% for DNA-cytometry and a specificity of 93% and a sensitivity of 100% with combined analyses. The positive predictive value was 90% for cytology, 96% for DNA-cytometry and for both analyses. The negative predictive value showed 100% for cytology, 89% for DNA-cytometry and 100% for combined studies. CONCLUSIONS: Despite the limited number of patients involved in the study, the results obtained indicate an increased of specificity and of positive predictive value using DNA-cytometry. These results confirm the pertinence of these method for challenging cases, in conjunction with other available diagnostic tools.

Adult↗

PubMed2001

Detection of malignant effusions: comparison of a telomerase assay and cytologic examination.

Telomerase is inactive in most somatic cells, but has been found to be reactivated in a majority of cancers. Our principal goal was to test whether the presence of telomerase activity concurred with positive cytology, and was thus of potential use in detecting cancer cells in effusions. The telomeric repeat amplification protocol (TRAP) assay and cytological examination were performed in a blinded fashion on 91 unselected effusions, for which laboratory processing was done according to standard procedures. In our series, 30% (27/91) of samples were found to be malignant by cytology. Of these, 19 (70%) were also positive in the TRAP assay. Of the 8 telomerase-negative cytology-positive samples, RNA integrity was generally poor, indicating suboptimal sample conservation for molecular analysis. Negative cytology in the presence of telomerase activity was observed in 17 effusions. Of these, 11 were from patients with advanced cancer, and thus a diagnosis of malignant effusion should be suspected. The TRAP assay for telomerase activity holds promise in the analysis of effusions, but its routine use as an adjunct to cytology awaits further confirmation of its positive predictive value.

Adolescent↗

PubMed2001

Pitfalls in TRAP assay in routine detection of malignancy in effusions.

Telomerase has been found to be reactivated in a majority of cancers but is inactive in most somatic cells. Our principal goal was to determine the potential use of the telomeric repeat amplification protocol (TRAP) assay as marker for malignancy in cytological effusions. The simple selection criterion was the cytological diagnosis, and routine samples were classified into malignant (58 samples) and nonmalignant (233 samples). Of the malignant samples, 44/58 (76%) were positive by TRAP assay. Of the 14 telomerase-negative cytology-positive samples, RNA integrity was poor in 9, indicating suboptimal sample conservation for molecular analysis. In 3 of the remaining 5 samples with a negative TRAP assay, a high number of malignant cells was observed, and these cells might have been telomerase-negative. Thus, the sensitivity of TRAP assay for the presence of malignant cells was about 76%. In the cytologically nonmalignant effusions, the presence of telomerase activity was observed in 24% (55/233). Of these, 6% were highly suspicious for malignancy, 9% were doubtful, and 9% were cytologically nonmalignant effusions confirmed by a follow-up of 12 mo or more. According to these data, the specificity of the TRAP assay to detect tumor cells in effusions ranged only between 82-91%. Our results indicate that, although the TRAP assay is positive in 6-15% of putative malignant effusions, the relatively high number of TRAP false-negative and false-positive cases renders this test unsuitable for routine diagnostic purposes.

Adolescent↗

PubMed1999

[Kidney spiral CT. Indication, method, results].

The introduction on spiral computed tomography (spiral CT) has vastly enriched the methodological diversity of computer-tomographic scans. It allows for the recording of different perfusion or excretion stages of the kidney parenchyma of the urine draining paths by carrying out long-distance, phase-identical multiple examinations of the retroperitoneum. The description of the findings which are characterized by their local and contrasts behavior is possible. The following report describes the indications and technological process of kidney spiral CT using kidney-typical intravenous contrast media. Special emphasis is put on the advantages and limits of multiple phase spiral CT. Decisive preconditions are: 1. specific clinical query, 2. selection of the corresponding phase contrasts of the kidneys and uretra or bladder, 3. exact technical and temporal adjustment of the acquisition parameters. Scanning times are in the range of seconds. The overall examination can be carried out quick and without any major strain on the part of the patient. A sound proof and a general differentiation of focal kidney lesions can be derived from the acquired data. This is also true for kidneys and ureters findings. Bladder findings can be localized and differentiated according to stage. More than two "spiral acquisitions" should be carried out with re-straint taking exposure to radiation into account. Due to the sound registration of focal lesions, its capability of reproduction and its short-time examination, the spiral CT of the kidneys can be said to be the most effective current scanning method of the retroperitoneum following clinical examinations and sonography.

Female↗

PubMed1999

Assessment of gastric cancer: value of breathhold technique and two-phase spiral CT.

The purpose of this study was to evaluate the capabilities of subsecond spiral CT in detecting and staging of gastric cancer. Our study included 40 patients with endoscopically detected gastric carcinomas. Two-phase spiral CT was performed within one breathhold each. Distension of the stomach was achieved by intravenous application of scopolamine and drinking of 500 ml water. After bolus injection of contrast medium, scanning was performed in the arterial and venous phase. Gastric tumour extention and lymph node involvement was assessed. Gastric cancer was detected in 39 of 40 cases (sensitivity 97.5%). Location of the tumour was correctly assessed in all cases. In 31 of the 39 cases (79.4%) CT staging was accordant with pathological staging. One hundred two (70%) of 145 nodes infiltrated by tumour tissue were detected and 144 (42.8%) of 336 nodes free of metastatic involvement were found. The predictive values of positive and negative results for the detection of lymph node metastases were 67.1 and 75%, respectively. Spiral CT is recommended for staging of gastric cancer.

Adenocarcinoma↗

PubMed1999

Evaluation of spiral CT in staging of colon and rectum carcinoma.

The purpose of our study was to evaluate the capability of a subsecond spiral-CT scanner using two contrast medium phases in staging of colorectal cancer. In our study we included 37 patients with proven rectum or colon carcinoma. Spiral CT was performed following tap-water enema of the colon in the arterial and venous phases of contrast medium enhancement. Our results were compared with the findings of pathological examination after surgery. The tumor's size and extension were evaluated in the arterial and venous phases, the lymph nodes in the venous phase of the CT scan. The tumor was in the rectum (n = 14), sigma (n = 11), descending colon (n = 6), and cecum (n = 6). Two-phase spiral CT had a sensitivity of 97.2% in the arterial phase and 89.1% in the venous phase in detecting the carcinoma. The staging results were in the arterial phase in 30 of 37 cases (81.0%) and in the venous phase in 24 of 37 cases (64.8%) according to pathology. In 27 of 32 patients (84.3%) lymph nodes were detected. The correct classification of the N-stage was possible in 23 of 34 cases (67.6%). The combined use of arterial and venous phases in staging of colorectal cancer can improve the T- and N-stage classification in comparison with using only one contrast medium phase. The arterial phase is superior compared with the venous phase for local tumor staging and the venous phase is used for lymph node assessment.

Adult↗

PubMed1999

Diffuse metastatic infiltration of a carcinoma into skeletal muscle.

Skeletal muscle is one of the most unusual sites of metastasis from any malignancy. We report a patient with rapidly progressive contractures due to metastatic infiltration of a carcinoma of unknown origin into the skeletal muscle. This 61-year-old man presented with a 1-month history of rapidly evolving, painful restriction of mobility of his right arm and his legs. Computed tomography showed diffuse metastatic nodules in all muscles, particularly in the hip abductors. Muscle biopsy revealed extensive infiltration of the muscle with carcinoma cells.

Biopsy↗

PubMed1997

Digital radiography.Results of a survey (part A) and a consensus conference (part B)

Digital imaging (digital image intensifier radiography, storage phosphor/selenium radiography) is increasingly becoming commonplace in radiology departments for diagnostic purposes. Despite 10 years of experience, the advantages and disadvantages of those methods are still heavily discussed among users, financiers and prescribers. This paper is to offer additional arguments for a thorough and objective discussion. No further comments or interpretations have been added to this paper. This paper consists of two main parts, A and B. The first part deals with the results of a user survey, the other part presents the results, i. e. statements, of a consensus conference.

Journal Article↗

PubMed1997

[Digital radiography--results of a user survey (A) and consensus conference (B)].

Digital radiography is increasingly replacing conventional radiography in imaging. For some years now, the pros and cons of this new method have been subject to intense discussions. For further discussion, the present article describes the results of an inquiry among users and of a consensus conference held in March 1996 in Munich. Comments and interpretations have been omitted on purpose.

Attitude of Health Personnel↗

PubMed1997

Digital radiography. Results of a survey (part A) and a consensus conference (part B).

Humans↗

PubMed1996

[Digital radiography. Cost-benefit analysis].

Due to its high dynamic range and contrast discernibility, digital radiography offers substantial advantages compared with conventional film-screen systems. Moreover, further advantages can be assumed for radiation protection. Digital radiography also allows conventional image data to be included in PACS (Picture Archiving Communication System). These well-known advantages are faced with legal questions which are not yet settled. Cost effectiveness in using systems of digital radiography and PACS are also under discussion. By means of examining economic efficiency and cost analysis of digital radiography systems, economic effectiveness was assessed. This was also compared with conventional alternatives. As a result, it may be assumed that amortization is reached in three to four years. Based on lower costs for films, digital systems are more cost effective than conventional systems after this period.

Cost-Benefit Analysis↗

PubMed1996

Effects of varying filter kernel sizes on the image quality of interstitial lung diseases.

PURPOSE: The aim of the study was to optimize the postprocessing of digital luminescence radiographs of interstitial infiltrates of the lung. MATERIAL AND METHODS: Ninety-seven patients with established diseases of the lung parenchyma were examined: 514 pathological details were investigated, using a 200-speed screen-film system and a storage phosphor plate. In digital postprocessing, the size of the filter kernel (S) varied between S 5 and S 70. Based upon 32896 individual evaluations, the image quality was evaluated in multifactorial variance analyses. RESULTS: The digital standards were significantly inferior to the tested screen-film system. The large filter kernel S 70 and the small filter kernels S 5 and S 10, as well as an algorithm for edge enhancement, showed selective advantages in the depiction of nodular or small linear structures. For micronodular and linear structures, kernel sizes of S 20 and S 40 produced equally good results (p > 0.05). CONCLUSION: Whenever optimized postprocessing is involved, storage phosphor radiography is equal to a modern screen-film system and can be substituted for the latter without any loss of image quality; this is especially valid for the imaging of interstitial infiltrates of the lung.

Female↗

PubMed1995

[Quantification of variations in arm perfusion after plexus anesthesia with color doppler sonography].

The axillary brachial plexus block is a well-known technique for intra- and postoperative analgesia and sympathetic blockade in hand and microsurgery. The aim of this study was to show the influence of the axillary brachial plexus block on the blood flow as a side effect. METHODS. We used a colour-coded sonography unit (Toshiba) with a 7.5-MHz transducer. A total of 12 patients with no clinical signs of vascular diseases were enrolled in this study. We measured the peak blood flow velocity and the peak flow at the bifurcation of the brachial artery and vein and the proximal and distal radial artery before and after the plexus block. In addition, we were able to take the morphological aspects of the analysed vessels into consideration as we also used conventional sonography. This was done to detect any early signs of vascular malformation or arteriosclerosis, either of which might have affected the measurements. RESULTS. The average arterial peak blood flow after the plexus block was 1.9 times that before. On the venous side, the block effect caused an average increase of the blood flow to 8.6 times than before the block. In general, an additional and immediate effect of the block was a significant rise in blood flow velocity with an increase in cross-section area. CONCLUSIONS. The brachial plexus block combines two advantages: pain relief and pain management plus temporary sympathectomy. In conclusion, it prevents vasospasms and improves the circulation of the hand in patients undergoing reimplantation of limbs and those with nutritional disorders.

Adolescent↗

PubMed1995

[Double-contrast arthro-CT in diagnosis of shoulder instability].

Timeless and lesion-related treatment are important in the different shoulder instabilities in order to get a good functional result. Within the step-by-step programme of diagnostic possibilities the double contrast computerised arthrotomography is particularly indicated in recurrent posttraumatic and habitual dislocations, in subluxations as well as for clarification of causes of postoperative recurrence. Besides the documentation of skeletal changes (Hill-Sachs-lesion, Bankart defect), double-contrast arthro-CT offers the possibility to identify detachments of the joint capsule or labral tears. Between 11/90 and 9/93 we performed 38 double contrast arthro-CTs for recurrent shoulder instabilities. 35 men and 3 women were examined. The mean age of the sportive patients were 29 years. Preoperatively we diagnosed in 21 cases a recurrent posttraumatic, in 7 cases a habitual shoulder instability. Apart from one multidirectional and three posterior instabilities we found two cases of subluxation. In the meantime 24 patients were treated with an open stabilising operation of the shoulder. The operative findings were compared with the results of double contrast arthro-CT. In a total of 38 performed arthro-CTs we found labral tears in 4 cases, 14 labral dissections, and 10 times a complete labral discontinuity. 8 of 9 labrum dissections found intraoperatively were correctly identified on CT. One dissection was not even seen retrospectively on arthro-CT. Six of nine complete labrum discontinuities were seen on arthro-CT, three described as a dissection. All capsular detachments and bony Bankart lesions found on CT were confirmed intraoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Transvenous sonography of the peripheral arterial vessels. The initial clinical results].

Intravascular ultrasound with 20 MHz/6.2-French transducer systems was used for arterial imaging via a transvenous approach. In 20 patients suffering from chronic arterial occlusive disease, 15 iliac arteries were evaluated during diagnostic angiography and 5 femoropopliteal arteries during balloon angioplasty (n = 3) and laser-assisted angioplasty (n = 2), respectively. Transvenous sonography did not allow differentiation of arterial wall layers and determination of vessel diameters as is usually possible during intraarterial sonography. Visualisation of iliac arteries was incomplete. In femoropopliteal vessels, guide wires could be detected within the arterial lumen but not in complete occlusions. Delivery of pulsed laser energy induced bright echoes near the catheter tip within a distance of 1-2 cm. Transvenous sonography is insufficient for monitoring of peripheral angioplasty; however, improved imaging quality might be possible at lower frequencies.

Aged↗