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Biomedical subjects

M Walz

Publications and source records attributed to M Walz.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Nonbacterial osteomyelitis of the clavicle].

Osteomyelitis can be subdivided into a bacterial exogenic (post-traumatic/postoperative), bacterial endogenic (hematogenous) and an abacterial type, including the rare group containing primary chronic sclerosing osteomyelitis, which is typically localized in the clavicle. In a review of the literature, the criteria for the various types of chronic sclerosing osteomyelitis are analyzed. Out of a group of 17 patients with osteomyelitis of the clavicle treated between 1978 and 1996, three cases of primary chronic sclerosing osteomyelitis are demonstrated. In the differential diagnosis, primary chronic sclerosing osteomyelitis of the clavicle has to be taken into consideration despite its rareness. After establishing a diagnosis by biopsy, in contrast to the other forms, drug therapy will be the treatment of choice and not an operation.

Adolescent↗
PubMed1998

[CPAP-augmented spontaneous respiration in thoracic trauma. An alternative to intubation].

Intubation and Positive End Expiratory Pressure Ventilation (PEEP) is a well established therapeutic strategy for impaired lung function, particularly following blunt chest trauma. Complications of this regime are however also well known and pose the question why non-invasive forms of respiratory assistance such as Continuous Positive Airway Pressure (CPAP) have only gained minor popularity. In a prospective study, 30 patients who had suffered blunt chest trauma were treated with CPAP administered by mask. The regime consisted of continuous administration of CPAP by a face-mask, with gradually increasing periods of spontaneous breathing. Initially a FiO2 of 0.33 (range 0, 28-0, 33) proved necessary. The initial CPAP level was 7 mbar (range 5-8) with an (Assisted Spontaneous Breathing) ASB of 15 mbar (range 13-8). FiO2 and CPAP/ASB levels were subsequently gradually reduced until no longer necessary. In all patients intubation and ventilation was avoided by this regimen. The treatment was well accepted by all patients and common ventilation associated complications such as pneumonia did not occur. In comparison with the former standard method of treatment the average ICU stay was dramatically reduced, principally due to not having to gradually wean patients from ventilation and sedation. Other positive benefits include normal communication and feeding with active early mobilisation leading to faster recovery, both physical and psychological. We conclude that non-invasive respiratory techniques should be used more frequently and recommend further studies are undertaken to define the indications.

Adult↗
PubMed1998

Teleradiology: results of a questionnaire of German radiologists.

A questionnaire was sent by mail to 4400 radiologists (i.e. to at least 1000 radiological institutions). The response rate was about 5%. The results showed that 47% of respondents felt well informed about teleradiology, 49% not enough and 3% not at all. Image and report transfer as well as interfaces to reference databases, educational applications, technical quality surveillance and product support (maintenance) were considered to be increasingly important areas. Smaller institutions (1-3 doctors) judged expert consultation as more important than bigger institutions. Standardization, system stability and data security were demanded as well as guidelines, for example concerning the linking of report and image, correct documentation and required image quality. Technically most demands can be fulfilled today but this technology is not yet commonly included in teleradiology systems.

Attitude of Health Personnel↗
PubMed1997

[Possible applications of the KAMEDIN teleradiology system with special reference to an economic analysis].

INTRODUCTION: Different concepts and applications of teleradiology systems have been realised. However, their cost-effectiveness is still questionable. Therefore, a cost-benefit analysis of three different scenarios of the new teleradiology system Kamedin (Kooperatives Arbeiten und rechnergestützte Medizinische Diagnostik auf innovativen Netzen der Deutschen Telekom) was performed. METHODS: CT examinations were transmitted from an Advantage Windows (GE) workstation to a Kamedin workstation using DICOM 3 protocol. Afterwards a teleconference was established with a Kamedin workstation in the intensive care unit within the hospital via FDDI/Ethernet, with an external workstation in a radiology department 6 km away via ISDN and with a Kamedin PC located with radiologist on duty 22 km away via ISDN. On average, 36 CT slices per patient were transferred. A break-even analysis was performed with respect to costs of hardware, software, support, use of ISDN and staff, as well as benefits like the decrease in transportation or film documentation costs. RESULTS: Owing to the different reductions in transportation costs, two applications (intensive care unit and external PC) showed a break-even of 1817 and 528 teleconferences/year, respectively. Further optimisation of cost-effectiveness is possible on condition that existing hardware can be used and an automatic data transfer without staff control is available. When all optimisation factors were combined, the break-even decreased to a minimum of 167 and 77 teleconferences/ year, respectively. CONCLUSION: Teleconferences with high image quality can be set up between workstations and PCs using the Kamedin system. Depending on the possible decrease in transportation costs, teleconferencing is cost-effective under certain conditions. Teleradiology has additional advantages, such as the acceleration and optimisation of patient management.

Computer Communication Networks↗
PubMed1997

[Goals, requirements and prerequisites of teleradiology. An assessment of current status].

Specific radiological requirements have to be considered for the realization of telemedicine. In this article the goals and requirements for an extensive introduction of teleradiology will be defined from the radiological user's point of view. Necessary medical, legal and professional prerequisites for teleradiology are presented. Essential requirements, such as data security, maintenance of personal rights and standardization, must be realized. Application-specific requirements, e.g. quality and extent of teleradiological functions, as well as technological alternatives, are discussed. Each project must be carefully planned in relation to one's own needs, extent of functions and system selection. Topics, such as acknowledgement of electronic documentation, reimbursement of teleradiology and liability, must be clarified. Legal advice and the observance of quality guidelines are recommended.

Forecasting↗
PubMed1996

The Use of Rare-Cutting Endonucleases in Electrophoretic Karyotyping of Fungal Genomes

A method for the fast and reliable restriction analysis of intact fungal chromosomes is presented. For this purpose rare-cutting restriction enzymes of pro- and eukaryotic origin were used. Restriction fragments were separated on pulsed-field gels. Complete inactivation of proteinases remaining from chromosome preparations was crucial in this attempt. Rare-cutting restriction enzymes were employed to demonstrate the applicability of this procedure to the analysis of complex fungal genomes. This includes the localization of genes on discrete chromosomal fragments,the identification of telomeric restriction fragments, and the analysis of fungal transformants.

Journal Article↗
PubMed1996

Arthroscopic diagnosis of posttraumatic disorders of the wrist.

Arthroscopy of the wrist is a helpful diagnostic procedure in cases of painful problems that cannot be diagnosed by clinical and radiological examination. Arthroscopy of the wrist was done in 32 patients, who could not be diagnosed by clinical and radiological examination. During arthroscopy, lesions of the fibrocartilaginous disc and of the cartilage, synovitis of the joint capsule, scaphoid-lunate dissociations and a loose body were detected. As a result of arthroscopic findings, 10 operative procedures were necessary. Resection of a torn disc, local synovectomy, reconstruction of the torn scaphoid-lunate ligament and removal of a loose body were done by open arthrotomy (8 patients). In 2 patients shaving of chondral ulcers on the radial joint surface was performed, which obviated the need for an explorative arthrotomy. Arthroscopy is a simple method that enables new diagnostic possibilities in rare but difficult cases of posttraumatic pain of the wrist.

Adult↗
PubMed1996

Post-transcriptional regulation associated with control of human CD8A expression of CD4+ T cells.

Lack of expression of a cell surface protein can occur by means of transcriptional and/or post-transcriptional mechanisms. Expression of the CD8A gene has been shown to be regulated by post-transcriptional mechanisms when 1) CD4(-)CD8(lo) thymocytes are blocked from differentiating into CD4(+)CD8(+) cells by TCR crosslinking and 2) upon activation of mature CD8(+) T cells. We demonstrate in this paper that there is also post-transcriptional regulation of CD8A expression in a CD4(+)CD8(-) T-cell line Jurkat. On the basis of northern blotting, mRNA for CD8A was not seen to be present in the Jurkat cells, but the gene was observed to be transcriptionally active in nuclear run-on analysis. In addition, we provide evidence that post-transcriptional mechanisms also contribute to the regulation of CD8A expression in mature CD4(+)CD8(-) T cells, challenging the assumption that the regulation is due solely to transcriptional mechanisms.

Animals↗
PubMed1996

[Development of a clinical-radiological CD-ROM database for focal lesions of the liver].

PURPOSE: The development of a CD-ROM database for continuous acquisition and archiving of interesting radiologic cases is described. As a pilot study radiologic images of focal lesions of the liver were collected. METHODS: The database runs on a PC (80486 DX2, 66 MHz, 16 MB RAM), which is connected to the clinic network, a high quality x-ray scanner and a CD-ROM writer. Radiologic images can be inserted into the database either by scanner or by image transfer via network. The database is designed using Access 2.0. Well documented cases were chosen retrospectively, manipulated and archived. RESULTS: 308 images of 12 focal lesions with a capacity of 802 MB were stored on CD-ROM. Per case a storage capacity of 40-75 MB is necessary for image raw material, 15-25 MB are necessary for the postprocessed data. Spatial resolution is 190 dpi (3000 pixel/40 cm). Clinical data, radiological diagnosis coded by modified ACR index and a compressed icon of the images are stored on PC, the image data are stored on CD-ROM. 2.5 hours per case are needed for the complete acquisition, manipulation and archiving procedure, but improved hardware configuration can reduce the time significantly. CONCLUSION: The described database allows continuous archiving of interesting radiologic cases on PC. ACR index is suited for a quick search of a specific combination of radiologic images and diagnosis from different modalities.

Angiography↗
PubMed1996

[Radiologic medical desktop conferences--clinical evaluation of the KAMEDIN teleradiology system in routine practice of a radiologic institute].

KAMEDIN is a teleradiology project of "Deutsche Telekom". ISDN based image transfer, visualisation and online-presentation of digital radiological images is performed. In this study the suitability of the KAMEDIN-system has been tested in a clinical environment. The software has been adapted to the requirements of radiological image visualisation. During 6 months over 50 conferences took place with an average of 36 CT-slices per patient. The amount of time was approximately 10 min for conference preparation, 20 min for image transfer and 8 min for conferencing. Software problems occurred and were solved. Image quality on the monitor as well as online presentation including "simultaneous cursors" showed high performance and achieved high acceptance by the clinicians. Thus KAMEDIN is a useful teleradiology system, especially if the system is adapted to the requirements of radiology departments.

Computer Systems↗
PubMed1996

[Development of minimal requirements for site assessment and monitoring to estimate exposure in environmental medicine--the Hamburg approach].

As a further step towards quality management in environmental medicine the Hamburg Association of Panel Physicians and the Hamburg Department of Labour, Health and Welfare developed a consensus paper concerning the handling of indoor related problems. It focuses on the cooperation between environmental physicians and engineers. A critical point in the process of environmental health risk assessment is the selection of either human biomonitoring or environmental monitoring. Further well-known problems are quality of measures and process documentation. Accurate, reliable measures of individual exposure are an essential need for physicians who have to judge the potential impact of environmental contaminants on human health. The approach proposed in this paper was chosen to enable the patient and the physician to benefit from the special knowledge of environmental engineers on indoor related problems. The procedure and criteria might help to reduce misclassifications of diseases and the amount of measures with no medical relevance and to establish scientifically valid associations between health outcomes and exposures to environmental contaminants.

Air Pollution, Indoor↗
PubMed1995

Transformation of Sordaria macrospora to hygromycin B resistance: characterization of transformants by electrophoretic karyotyping and tetrad analysis.

The ascomycete Sordaria macrospora was transformed using different plasmid molecules containing the bacterial hygromycin B resistance gene (hph) under the control of different expression signals. The highest transformation frequency was obtained with vector pMW1. On this plasmid molecule, expression of the hph gene is directed by the upstream region of the isopenicillin N synthetase gene (pcbC) from the deuteromycete Acremonium chrysogenum. Southern analysis suggests that the vector copies are integrated as tandem repeats into the S. macrospora chromosomes and that duplicated sequences are most probably not inactivated by methylation during meiosis. Furthermore, the hygromycin B resistance (hygR) is not correlated with the number of integrated vector molecules. Electrophoretic karyotyping was used to further characterize S. macrospora transformants. Five chromosomal bands were separated by pulsed-field gel electrophoresis (PFGE) representing seven chromosomes with a total genome size of 39.5Mb. Hybridization analysis revealed ectopic integration of vector DNA into different chromosomes. In a few transformants, major rearrangements were detected. Transformants were sexually propagated to analyze the fate of the heterologous vector DNA. Although the hygR phenotype is stably maintained during mitosis, about a third of all lines tested showed loss of the resistance marker gene after meiosis. However, as was concluded from electrophoretic karyotyping, the resistant spores showed a Mendelian segregation of the integrated vector molecules in at least three consecutive generations. Our data indicate that heterologous marker genes can be used for transformation tagging, or the molecular mapping of chromosomal loci in S. macrospora.

Ascomycota↗
PubMed1995

[Long-term results of cemented total endoprostheses of the hip joint].

211 Müller-Charnley resp. Müller-Straight-Stem prostheses have been implanted from 1974 to 1984 in our Department for Trauma-Surgery. They were evaluated 11.8 years after implantation by clinical and radiological examination. 24 (12.8%) prostheses have been replaced because of aseptic loosening. Patients have been further evaluated by means of a new score, which emphasizes the mobility of the patients after total hip replacement. Mobility decreases significantly in patients over 70 years.

Activities of Daily Living↗
PubMed1995

[Control of disordered wound healing using sonography based on postoperative follow-up after TEP implantation].

Clinical diagnosis of early postoperative complications remains a major issue in patients undergoing total hip replacement. Early diagnosis is essential because (clinical) signs of inflammations as fever or elevated white blood count already reflecting late complications. The goal of our study was to evaluate postoperative monitoring for early detection and treatment of hematoma and abscess following total hip replacement. 308 patients undergoing total hip replacement were postoperatively monitored for the development of hematoma and abscess, comparing routine ultrasound to on demand ultrasound in case of clinical signs of infection. The diagnostic puncture was 6.5% (10/154) in group A (on demand ultrasound) versus 11.7% (18/154) in group B (routine ultrasound). Infections were seen in 5.2% (8/154) of patients in group A compared to 0.6% (1/154) in group B, leading to surgical intervention in 3.3% (5/154) group A, respectively 0.6% (1/154) in group B.

Abscess↗