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Biomedical subjects

E Lang

Publications and source records attributed to E Lang.

At least 19 recordsLinked to original sources

Powered instrumentation in obstructing laryngeal tumours.

Traditionally, debulking of obstructing laryngeal tumours has been performed with cold steel instruments or CO2 lasers. With recent technological advances and increased availability of microdebriders, powered instrumentation for debulking laryngeal tumours has become a viable option. We describe the use of the Xomed laryngeal Tricut blade in re-establishing the airways in four patients with obstructing laryngeal tumours. In all cases a tracheostomy was avoided, thus allowing adequate time to stage each patient and tailor surgery to the individual.

Aged↗

Epifluorescence, confocal and total internal reflection microscopy for single-molecule experiments: a quantitative comparison.

Epifluorescence, confocal and total internal reflection microscopy are the most widely used techniques for optical single-molecule experiments. Employing these methods, we recorded the emission intensity of the same single molecule as a function of the excitation rate under otherwise identical experimental conditions. Evaluation of these data provides a quantitative comparison of the signal-to-background ratios that can be achieved for the three microscopic techniques.

Journal Article↗

Bioinformatics and its impact on clinical research methods. Findings from the Section on Bioinformatics.

OBJECTIVES: To summarize current excellent research in the field of bioinformatics. METHOD: Synopsis of the articles selected for the IMIA Yearbook 2006. RESULTS: Current research in the field of bioinformatics clearly shows ongoing unification of experimental findings and clinical outcomes. Microarray data, gene sequences and clinical data are more and more perceived as different but related facets of one entity. Significant work is done in the area of text and data mining in order to bring together patient data and biochemical phenomena by means of ontologies. A strong trend in the clinical field is performance of exhaustive studies on DNA material derived from patients that suffer from diseases that are already known to be inherited. Examination of appropriate methods covers data and text mining, ontologies as well as machine learning and classification. CONCLUSIONS: The best paper selection of articles on bioinformatics shows examples of excellent research on methods used for studying inherited diseases and their underlying genetic dispositions. Clinical studies, inclusion of experimental findings like microarray data, and of knowledge representation formats all lead to a better understanding the linkage between gene sequences, biological functions and clinical findings in the form of healthy state or physiological disorders.

Awards and Prizes↗

Radiation therapy induced modulation of wound healing at experimental vein graft anastomoses.

OBJECTIVES: The aim of this study was to investigate if radiation therapy (RT) favorably modulates wound healing at vein graft anastomoses. MATERIALS AND METHODS: Jugular vein grafts were sewn into carotid arteries in 32 rats which were randomly divided into two groups: RT (gamma source, 14 Gray, n=16) and control (C, sham irradiation, n=16). Grafts and adjacent arteries were analyzed at 2 (n=8) and 8 weeks (n=8) by histology, immunohistochemistry, and morphometry. RESULTS: Although, RT did not reduce the overall occurrence of intimal hyperplasia, the distribution differed. RT led to a reduction of intimal hyperplasia in arterial segments (median: C: 41.873 microm2; RT: 6.452 microm2, p < 0.0007). In contrast, RT augmented intimal hyperplasia in vein grafts (median: C: 30.287 microm2; RT: 90.455 microm2, p < 0.014). Vein graft diameters after RT were enlarged (median: C: 2.098 microm; RT: 3.381, p < 0.031). Over 80% of the cells were of mesenchymal origin in both groups. CONCLUSIONS: RT reduced intimal hyperplasia in arterial segments. However, RT led to graft dilatation and increased intimal hyperplasia in vein grafts. RT did not favorably modulate the vascular wound healing response in this model.

Anastomosis, Surgical↗

Neurovascular relationship at the trigeminal root entry zone in persistent idiopathic facial pain: findings from MRI 3D visualisation.

BACKGROUND: Patients with atypical neuralgia or atypical facial pain have been surgically treated with microvascular decompression (MVD) of the trigeminal root entry zone (TREZ). There are no data regarding the sensitivity and specificity of a vessel-TREZ relationship as a cause of pain in patients with persistent idiopathic facial pain (PIFP) according to the definition given by the International Headache Society (IHS). METHODS: The TREZ was visualised by 3D CISS MRI in 12 patients with unilateral PIFP according to the IHS criteria. RESULTS: The frequency of artery-TREZ, vein-TREZ, or vessel (artery/vein)-TREZ contacts on the symptomatic and asymptomatic sides did not differ significantly. On the symptomatic side, vessel-TREZ contact was found in 58% of patients (sensitivity). On the asymptomatic side, vessel-TREZ contact was absent in 33% of patients (specificity). CONCLUSIONS: On the basis of the low sensitivity and specificity found in the present study, PIFP cannot be attributed to a vessel-TREZ contact, and therefore, pain relief after MVD cannot be expected.

Aged↗

The challenge of ubiquitous computing in health care: technology, concepts and solutions. Findings from the IMIA Yearbook of Medical Informatics 2005.

OBJECTIVES: To review recent research efforts in the field of ubiquitous computing in health care. To identify current research trends and further challenges for medical informatics. METHODS: Analysis of the contents of the Yearbook on Medical Informatics 2005 of the International Medical Informatics Association (IMIA). RESULTS: The Yearbook of Medical Informatics 2005 includes 34 original papers selected from 22 peer-reviewed scientific journals related to several distinct research areas: health and clinical management, patient records, health information systems, medical signal processing and biomedical imaging, decision support, knowledge representation and management, education and consumer informatics as well as bioinformatics. A special section on ubiquitous health care systems is devoted to recent developments in the application of ubiquitous computing in health care. Besides additional synoptical reviews of each of the sections the Yearbook includes invited reviews concerning E-Health strategies, primary care informatics and wearable healthcare. CONCLUSIONS: Several publications demonstrate the potential of ubiquitous computing to enhance effectiveness of health services delivery and organization. But ubiquitous computing is also a societal challenge, caused by the surrounding but unobtrusive character of this technology. Contributions from nearly all of the established sub-disciplines of medical informatics are demanded to turn the visions of this promising new research field into reality.

Biomedical Technology↗

Study of clinical features of amyloid angiopathy hemorrhage and hypertensive intracerebral hemorrhage.

OBJECTIVE: The purpose of this study was to differentiate between cerebral amyloid angiopathy (CAA) and hypertension (HTN) based on hemorrhage pattern interpretation. METHODS: From June 1994 to Oct., 2000, 83 patients admitted to our service with acute intracerebral hemorrhage (ICH) were investigated retrospectively; 41 patients with histologically proven diagnosis of cerebral amyloid angiography and 42 patients with clear history of hypertension were investigated. RESULTS: Patients with a CAA-related ICH were significantly older than patients with a HTN-related ICH (74.0 years vs 66.5 years, P < 0.05). There was a significantly higher number of hematomas > or = 30 ml in CAA (85.3%) when compared with HTN (59.5%). No basal ganglional hemorrhage was seen in CAA, but in 40.5% in HTN. In CAA-related ICH, subarachnoid hemorrhage (SAH) was seen in 26 patients (63.4%) compared to only 11 patients (26.2%) in HTN-related ICH. Intraventricular hemorrhage was seen in 24.4% in CAA, and in 26.2% in HTN. Typical features of CAA-related ICH included lobar distribution affecting mainly the lobar superficial areas, lobulated appearance, rupture into the subarachnoid space, and secondary IVH from the lobar hemorrhage. More specifically, multiplicity of hemorrhage, bilaterality, and repeated episodes also strongly suggest the diagnosis of CAA. Multiple hemorrhages, defined as 2 or more separate hematomas in multiple lobes, accounted for 17.1% in CAA-related ICH. CONCLUSION: There are certain features in CAA on CT and MRI and in clinical settings. To some extent, these features may contribute to distinguishing CAA from HTN related ICH.

Adult↗

Towards clinical bioinformatics: advancing genomic medicine with informatics methods and tools.

OBJECTIVES: To summarize the challenges facing clinical applications in the light of growing research results in genomic medicine and bioinformatics. METHODS: Analysis of the contents of the Yearbook of Medical Informatics 2004 of the International Medical Informatics Association (IMIA). RESULTS: The Yearbook of Medical Informatics 2004 includes 32 articles selected from 22 peer-reviewed scientific journals. A special section on clinical bioinformatics highlights recent developments in this field. Several guest editors review the promises and limitations of available methods and resources from biomedical informatics that are relevant to clinical medicine. Integrated data and knowledge resources are generally regarded to be central and key issues for clinical bioinformatics. Further review papers deal with public health implications of bioinformatics, knowledge management and trends in health care education. The Yearbook includes for the first time a section on the history of medical informatics, where the significant impact of the Reisensburg protocol 1973 on international health and medical informatics education is examined. CONCLUSIONS: Close collaboration between bioinformatics and medical informatics researchers can contribute to new insights in genomic medicine and contribute towards the more efficient and effective use of genomic data to advance clinical care.

Computational Biology↗

[Interventions for improvement of primary care in patients with low back pain: how effective are advice to primary care physicians on therapies and a multimodal therapy program arising out of cooperation of outpatient health care structures?].

BACKGROUND: Treatment for chronic low back pain in primary care has a poor-quality outcome. There is evidence that multimodal therapy is the most successful approach to its management. We tried to evaluate whether giving primary care physicians evidence-based recommendations on therapy of chronic back pain or directly implementing a multimodal program would improve the outcome of patients with low back pain treated in primary care. METHODS: In the first phase, physicians were asked to document the course of patients suffering from low back pain of at least 4 weeks' duration with no decrease in intensity, noting pain intensity before and after 6 months of conventional, nonsurgical treatments. In the present, second, phase of the study, recommendations issued by the Medicines Committee of the German Medical Profession and the U.S. Agency for Health Care Policy and Research for the management of back pain were presented to doctors in printed form and at conferences. In parallel with this, a multimodal program for the treatment of chronic low back pain (4 h/day for 20 days: medical training therapy, cognitive-behavioral therapy, physiotherapy, and patient education) was organized in a private health-oriented sports center in cooperation with three private physiotherapy practices, and a psychologist and a pain specialist from the outpatient pain clinic at the University Hospital in Erlangen. We examined how physicians changed the therapy and how effective it was, the latter as reflected in the mean sum value of the percent pre- to posttreatment changes in pain intensity, how much pain interfered with daily living, depressivity, and quality of life. Data after interventions were compared with baseline data from the first phase. RESULTS: Data relating to 36 patients following treatment by 14 primary care physicians who had been given information about therapy recommendations and to 51 patients who had participated in the multimodal therapy program were compared with baseline data recorded in 157 patients. Recommendations changed neither the therapy preferred by primary care physicians nor the quality of outcome of conventional treatment. In contrast, the multimodal program of therapy for chronic low back pain improved the outcome significantly more than conventional therapy (mean improvement in general outcome score 22 vs. 7%, respectively, compared with baseline data; P<0.001). CONCLUSIONS: Giving primary care physicians information on the therapy recommended for treatment of low back pain does not lead to any change in physicians' preferred therapy. Multimodal programs for treatment of chronic low back pain should be organized locally, with existing health care providers joining forces to improve the quality of outcome in chronic low back pain managed in primary care.

Adult↗

LINUCS: linear notation for unique description of carbohydrate sequences.

The use of proteomics databases has become indispensable for daily work of molecular biologists, but this situation has not yet been achieved for carbohydrate applications. One obvious reason is that existing data collections are only rarely annotated and no cross-linking to other resources exists. The existence of a generally accepted linear, canonical description for carbohydrates which can be readily processed by computers will enable efficient automatic cross-linking of distributed carbohydrate data collections by serving as a unique and unambiguous database access key. Various possibilities to derive a canonical notation are discussed. They can be divided into attempts that require structure description alone and alternatives that profit from the fact that a preferred graph direction (non-reducing to reducing end) exists within the structure. To open a fruitful discussion among glycoscientists a possible solution is presented where the reducing monosaccharide unit is selected as graph root and linkage information is used to define the priority of the various branches. A Web interface (http://www.dkfz.de/spec/linucs/) has been created that directly converts the commonly used extended representation of complex carbohydrates into the preferred canonical description or into its inverted form.

Algorithms↗

Randomised controlled trial of specialist nurse intervention in heart failure.

OBJECTIVES: To determine whether specialist nurse intervention improves outcome in patients with chronic heart failure. DESIGN: Randomised controlled trial. SETTING: Acute medical admissions unit in a teaching hospital. PARTICIPANTS: 165 patients admitted with heart failure due to left ventricular systolic dysfunction. The intervention started before discharge and continued thereafter with home visits for up to 1 year. MAIN OUTCOME MEASURES: Time to first event analysis of death from all causes or readmission to hospital with worsening heart failure. RESULTS: 31 patients (37%) in the intervention group died or were readmitted with heart failure compared with 45 (53%) in the usual care group (hazard ratio=0.61, 95% confidence interval 0.33 to 0.96). Compared with usual care, patients in the intervention group had fewer readmissions for any reason (86 v 114, P=0.018), fewer admissions for heart failure (19 v 45, P<0.001) and spent fewer days in hospital for heart failure (mean 3.43 v 7.46 days, P=0.0051). CONCLUSIONS: Specially trained nurses can improve the outcome of patients admitted to hospital with heart failure.

Aged↗

[Calcified plaque of the extracranial carotid arteries in comparison with traditional risk factors as a predictor for relevant coronary artery stenoses].

BACKGROUND: Intima-media thickness (IMT) of carotid arteries, measured by vascular ultrasound, has widely been used as a surrogate marker for coronary atherosclerosis. As recent studies showed significant but only weak correlation between IMT and coronary artery stenoses, this study evaluated calcified plaques in the extracranial carotid arteries as a reasonable marker for coronary artery disease. PATIENTS AND METHOD: 139 patients underwent cardiac catheterization with selective coronary angiography and ultrasound examination (B-mode, standard Doppler, color Doppler) of the carotid arteries. In case of calcified plaques number and distribution among the extracranial cerebral arteries were determined (Figure 1). Coronary angiograms were analyzed for disease severity and extent (number of main vessels with > 50% stenosis). Besides the traditional vascular risk factors hypertension, diabetes, smoking and hypercholesterolemia as well as body mass index, age and sex were analyzed. RESULTS: Calcified plaques of carotid arteries were significantly correlated (r = 0.502, p < 0.001) with coronary artery stenoses as well as hypercholesterolemia (r = 0.410, p < 0.001), increasing age (r = 0.406, p < 0.001) and diabetes (r = 0.290, p < 0.001) in contrast to hypertension (r = 0.125, p = 0.075), smoking status (r = -0.043, p = 0.311), body mass index (r = -0.122, p = 0.083) and male sex (r = -0.103, p = 0.114) (Table 1). The number of calcified plaques was significantly correlated (r = 0.568, p < 0.001) with severity and extent of coronary artery disease, too (Figure 2). For two and more calcified plaques sensitivity concerning coronary artery stenoses was 80%, specificity 75%, positive predictive value 83%, negative predictive value 73% (Table 2). Multiple stepwise regression analysis was performed for all eight variables (calcified plaques, hypercholestrolemia, diabetes, hypertension, smoking status, age, sex, body mass index). Including calcified plaques the predictive value of all factors was higher (r = 0.644 to r = 0.607). CONCLUSIONS: Determination of calcified carotid plaques by ultrasound is useful to improve the predictive value of risk factor-based multivariate models based on traditional risk factors.

Adult↗

[Radiotherapy for basal cell carcinoma. Local control and cosmetic outcome].

BACKGROUND: The basal cell carcinoma which is often occurring in the elderly can be well treated by surgery. For large and recurrent lesions and in cosmetically difficult locations external beam radiotherapy provides an equally effective treatment alternative. PATIENTS AND METHODS: From 1986 to 1999, 60 females and 39 males received primary radiotherapy for a total of 127 histologically verified basal cell carcinoma lesions. Tumors were mostly localized in the face at the temple, nose and forehead. Radiotherapy was applied with orthovoltage equipment and energies of up to 100 kV. Single doses ranged from 2 to 5 Gy related to the 80%-isodose depth. Weekly doses ranged from 8 to 25 Gy and total doses from 25 to 60 Gy. The mean follow-up period was 36 +/- 21 months. The acute sequelae were scored according to CTC criteria. Radiogenic late effects as single events were related to the radiation portal. RESULTS: 3 months after treatment all besides one patient (99%) experienced complete tumor remission (CR). In all cases, acute radiation reaction occurred within the radiation portal: CTC Grade 1 in 100%, CTC Grade 2 in 54% and CTC Grade 3 in 30% of the cases. All side effects regressed under simple local measures without further complications. Late sequelae were observed in three cases. Overall cosmetic outcome was good to excellent in almost all patients (98%). In two cases (2%) a local recurrence was observed 6 and 20 months after radiotherapy. CONCLUSION: External beam (orthovoltage) radiotherapy is very effective and yields high tumor control rates and good cosmetic results in long-term follow-up. Former dermatological treatment concepts should be replaced by an ICRU-based radiophysical dose prescription and should respect the newer radiobiological fractionation principles.

Aged↗

Organotypical engineering of differentiated composite-skin equivalents of human keratinocytes in a collagen-GAG matrix (INTEGRA Artificial Skin) in a perfusion culture system.

BACKGROUND: The production of autologous composite skin equivalents for the treatment of full-thickness skin defects in burns is time consuming and costly because of laboratory procedures which have to be performed manually. In the present study keratinocytes were seeded into INTEGRA Artificial Skin and placed in a perfusion culture system in order to evaluate the possibility of producing composite grafts in an automated system with the aim of establishing a cost-effective method of industrial production. METHODS: Composite grafts of INTEGRA and human keratinocytes were raised in perfusion culture and grafted onto athymic mice to evaluate their potential to reconstitute a full-thickness skin substitute in vivo compared to grafts from standard stagnant cultures. RESULTS: Cultured composites from perfusion cultures showed no significant histological differences compared to those from stagnant cultures; however, a tendency of improved cell growth and a more surface-oriented localization was observed. Cell proliferation and surface-bound differentiation were not impaired by the use of carbonate-independent buffering (HEPES), which is necessary for perfusion culture. The composite grafts from perfusion culture exhibited identical wound adherence and complete healing and histologically represented a multi-layered, keratinizing human epidermis. CONCLUSION: Engineering of differentiated composite skin equivalents is possible in a perfusion culture system, which offers technical and procedural and possibly even biological advantages compared to standard stagnant culture methods. The development of automated perfusion culture systems for the production of composite grafts in sizes required clinically (scale-up) will be the next step in the cost-effective engineering of large-scale composite skin equivalents.

Animals↗

[Effects of recommendations and patient seminars on effectivity of outpatient treatment for headache].

BACKGROUND: Treatment of patients suffering from migraine and/or tension-type headache in primary care needs to be improved. To this purpose we tested two strategies for implementation of evidence-based recommendations for treatment of headaches: first, communication of recommendations to the primary care physicians and, second, standardized communication and discussion of these recommendations with patients in combination with exercising of progressive muscle relaxation during patient seminars. METHODS: Patients with at least 2 migraine attacks/month or 8 days of tension-type headache/month were included in the study. Evidence-based pharmacological and non-pharmacological recommendations of the Medicines Committee of the German Medical Profession for treatment of migraine and tension-type headache have been offered to primary care physicians by printed material and during conferences. Patient seminars at 10 days for 2 hours were organized by the outpatient pain facility of the neurological department of the university of Erlangen. During seminars the patients were informed about these recommendations and learned progressive muscle relaxation. Agreed therapy between physician and patient was documented by physicians and patients during a 6 months treatment interval and compared with the recommended therapy. Effectivity of treatment was assessed by pre-post changes of days of headache/month, attack frequency/month, headache intensity (visual analogue scale), pain related impairment (German version of the Brief Pain Inventory), and health related quality of life (German Version of the SF-36). 51 patients were documented by 24 primary care physicians after communication of recommendations and 46 patients completed the patient seminar. Data of both groups were compared with those of 80 patients from primary care physicians before interventions. RESULTS: Communication of recommendations for headache therapy to primary care physicians did not improve conformity of the agreed therapy with the recommended. Contrary conformity of the agreed therapy for pharmacological treatment of migraine attacks and interval therapy of migraine by progressive muscle relaxation with the recommended therapy improved significantly. However, interventions did not significantly improve the outcome quality of outpatient treatment as compared to the therapy of primary care physicians before interventions. CONCLUSION: Effectivity of headache treatment in primary health care could not be improved by communication of evidence-based recommended therapy to primary care physicians nor by direct information of patients about these recommendations in combination with provided availability to learn progressive muscle relaxation.

Adult↗