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Biomedical subjects

A Weber

Publications and source records attributed to A Weber.

At least 55 records · Page 3Linked to original sources

[Guidelines and their practical application in congenital hearing loss].

BACKGROUND: Permanent congenital hearing loss in children does not only influence speech acquisition but also has a severe impact on the entire intellectual and psychological development, and thus social integration is handicapped. However, at least partial compensation can be achieved by complex rehabilitative measures. One of the first medical therapies in children with congenital hearing loss is to equip them with hearing aids. As part of quality management the purpose of this study is to discuss pedaudiological aspects and results of hearing - impaired children equipped with hearing aids against the background of guidelines from Germany and the US. METHODS: Data of 107 children equipped with hearing aids from 1997 to 1999 were analysed referring to the relevant German and US guideline. RESULTS: In 53 girls and 54 boys, 45% were suffering from at least severe, 45% from moderate and 10% from mild hearing loss. 93 children presented sensory hearing loss, 8 combined and 2 conductive hearing loss. 2 children had unilateral hearing loss, one a combined on one ear and a sensory hearing loss on the other and one child had a central auditory processing disorder. The age when the hearing loss was diagnosed depended on its grade and correlated with adverse environmental aspects. 34 children suffered from a syndrome or multiple handicaps, in these cases, the hearing loss was diagnosed at a later date than in children suffering from hearing loss only. In cases with near deafness audiological results with hearing aids were not sufficient; in these cases, cochlea implantation had to be discussed as an alternative measure. CONCLUSION: The data obtained from this study underline the need for universal hearing screening. Discussing the data against the relevant German and US guidelines clearly shows that German benchmarks are not as strict as the American ones. This has to be taken into account for further guideline development in Germany. As permanent hearing loss in children with syndromes and multiple handicaps and children with adverse environment is diagnosed at a later date than in other children public, measures have to be taken to improve this situation.

Adolescent↗

Complete sequencing shows a role for MSX1 in non-syndromic cleft lip and palate.

MSX1 has been proposed as a gene in which mutations may contribute to non-syndromic forms of cleft lip and/or cleft palate. Support for this comes from human linkage and linkage disequilibrium studies, chromosomal deletions resulting in haploinsufficiency, a large family with a stop codon mutation that includes clefting as a phenotype, and the Msx1 phenotype in a knockout mouse. This report describes a population based scan for mutations encompassing the sense and antisense transcribed sequence of MSX1 (two exons, one intron). We compare the completed genomic sequence of MSX1 to the mouse Msx1 sequence to identify non-coding homology regions, and sequence highly conserved elements. The samples studied were drawn from a panethnic collection including people of European, Asian, and native South American ancestry. The gene was sequenced in 917 people and potentially aetiological mutations were identified in 16. These included missense mutations in conserved amino acids and point mutations in conserved regions not identified in any of 500 controls sequenced. Five different missense mutations in seven unrelated subjects with clefting are described. Evolutionary sequence comparisons of all known Msx1 orthologues placed the amino acid substitutions in context. Four rare mutations were found in non-coding regions that are highly conserved and disrupt probable regulatory regions. In addition, a panel of 18 population specific polymorphic variants were identified that will be useful in future haplotype analyses of MSX1. MSX1 mutations are found in 2% of cases of clefting and should be considered for genetic counselling implications, particularly in those families in which autosomal dominant inheritance patterns or dental anomalies appear to be cosegregating with the clefting phenotype.

Amino Acid Sequence↗

[The "classical" macrophage marker CD68 is strongly expressed in primary human fibroblasts].

AIM: Monoclonal antibodies against the human homologue of mouse macrosialin, CD68, are generally commercialized as markers for human monocytes and macrophages. Indeed, CD68 is considered as a selective marker for human myeloid cells, although several previous immunohistochemical studies indicate that some antibody clones also react with other hematopoietic and non-hematopoietic cell types. The aim of our study was to verify these observations and to evaluate the reliability of CD68 as a macrophage marker. METHODS: We investigated protein and RNA expression of CD68 in various fibroblast types and carcinoma cell lines as compared to monocytes and macrophages using immunohistochemistry, flow cytometry, and specific RT-PCR. Different monoclonal antibody clones against CD68 were applied including KP-1 and EBM11. RESULTS: As expected, the intensity of immunohistochemical and flow cytometric CD68 staining was dependent on both the antibody clone and the fixation procedure. However, fibroblasts isolated from normal skin, normal breast, breast tumor tissue, and osteoarthritis synovia clearly expressed CD68 protein at levels comparable to macrophages. The specificity of CD68 expression in fibroblasts was verified by RT-PCR which also showed some tumor cell types to express CD68 mRNA. CONCLUSION: Our findings clearly demonstrate that the expression of CD68 is not restricted to the macrophage lineage. This is highly relevant for experimental and diagnostic purposes, since anti CD68 antibodies cannot be accepted without reservations for the discrimination of myeloid cells and fibroblasts even in paraffin sections after formalin fixation.

Antigens, CD↗

[Illness related early pensioning of high school teachers].

The problem of premature unfitness for work of (grammar school) teachers is of great social and social-medical interest. The possible causes and suitable measures of intervention remain a subject of controversy. The aim of this study was, on the basis of a random sample of a large number of cases, to gain a differentiated overview of the extent and type of early retirement due to illness of grammar school teachers, in order to be able to develop evidence-based strategies for prevention and intervention. In a prospective evaluation, all the assessments of illness-related unfitness for work drawn up for civil servants and teachers between 1.1.1996 and 31.12.1999 in Bavaria were first of all systematically evaluated. In addition, from the total collective a subgroup was formed of grammar school teachers and this was analysed separately. The answers given in a standardized, anonymous questionnaire provided the database. The evaluation included e.g. socio-demographic and occupational factors, the morbidity spectrum, medical judgement, medical rehabilitation and evaluation of performance. The medical diagnoses of the main and accompanying illnesses were classified according to ICD 10 in organ-related groups. Evaluation was carried out by means of descriptive statistics. Of the 655 grammar school teachers assessed, 65% (n = 429) were men, 35% (n = 226) women. The median age for male teachers was 58 years old (range: 30-64 years old), for female teachers 55 years old (range: 32-63 years old). Previous conflicts at the school workplace were reported in 12% of the cases. Among the main medical diagnoses, psychic/psychosomatic complaints (41%) predominated over muscular/skeletal illnesses (14%) and cardio-vascular diseases (12%). 80% of those examined were judged unfit for work. 56% of the grammar school teachers had participated in at least one medical rehabilitation measure before the proceedings for determining unfitness for work were instigated. Psychic and psychosomatic illnesses took first place among the decisive complaints leading to early retirement, and made up 45% of these. Further differentiation revealed the predominance of depressive illnesses and exhaustion (burnout). The main somatic complaints were far less common: muscular/skeletal illnesses (13%), cardio-vascular diseases (12%) and malignant growths (8%). The performance of 70% of the grammar school teachers judged unfit for work was regarded as so severely reduced that even activity outside of the teaching profession was no longer feasible. In this first representative evaluation of illness-related early retirement in grammar school teachers, the high prevalence and great social-medical importance of psychic and psychosomatic illnesses is noteworthy. In Bavaria, almost every second grammar school teacher therefore becomes unfit for work as a result of such complaints long before they reach the normal retiring age. From a social-medical and occupational-medical point of view, there is urgent need for further research into potential illness-inducing occupational and non-occupational stress factors and the development and implementation of effective and efficient strategies for prevention and intervention.

Adult↗

Coordination-number dependence of magnetic hyperfine fields at (111)Cd on Ni surfaces.

Ferromagnetic Ni surfaces were investigated on an atomic scale using the perturbed angular correlation spectroscopy probe (111)Cd. A comprehensive set of data for magnetic hyperfine fields (B(hf)) at various probe sites is presented. A field variation from -7 T in Ni bulk to the surprisingly large value of 16 T at the adatom position on Ni(111) is observed. A continuous nonlinear dependence is found, correlating the experimental B(hf) values with the number of their nearest Ni neighbors. The data are discussed on the basis of recent calculations on B(hf) values at sp-element impurities on ferromagnetic surfaces.

Journal Article↗

[Parapharyngeal space-occupying lesions. Differential diagnosis based on case examples].

INTRODUCTION: Parapharyngeal tumors account for only 0.8% of all head and neck tumors which often presents the problem of preoperative diagnosis. Up to 80% of parapharyngeal tumors are benign. PATIENTS: Starting November 1995 to March 2001, 16 patients with parapharyngeal tumors and 1 retropharyngeal abscess were treated. The median age was 54 years. Only 2 patients demonstrated peripheral nerve lesions preoperatively. RESULTS: 17 tumors and the retropharyngeal abscess were excised via transcervical approach, with an extension by parotidectomy and temporary mandibular split in 1 case. Histological entities were pleomorphic adenomas in 5 cases, a ganglioneurinoma, neurinoma of the vagal nerve and metastasis of a squamous cell carcinoma in 2 patients each, furthermore neuroblastoma, extramedullary plasmocytoma, T-cell lymphoma, and hemangioma in 1 patient each. CONCLUSIONS: We demonstrate the differential diagnosis of parapharyngeal tumors as well as their diagnostic and therapeutic management. The tumors should be excised by a transcervical approach to protect cervical vessels and nerves, which is limited by a transoral approach.

Adolescent↗

Magnetic resonance imaging following fat obliteration of the frontal sinus.

The paper describes the evaluation of magnetic resonance imaging (MRI) following osteoplastic flap procedure with fat obliteration. MRI scans performed in patients after surgery between 1st January 1986 and 31st December 1997 were evaluated. Outcome parameters were time-dependent changes in the distribution of adipose or connective tissue, development of necroses or oil cysts, recurrences, inflammatory complications, or mucocoeles. Eighty-six postoperative MRI scans from 51 operations were evaluated. In 19 cases between two and five MRI scans were available. Time between surgery and the last MRI scan was 24.1 months on average. We found five mucocoeles. The amount of adipose tissue depictable on the last scan was less than 20% in the majority of cases (53%) and more than 60% in only 18% of cases. Statistical tests and modelling showed a significant decrease of adipose tissue with time, with a median half-life of 15.4 months in a subgroup with at least two MRIs. MRI is at times the most valuable diagnostic tool after frontal sinus obliteration using adipose tissue. The method has some limitations with regard to detection of small (recurrences of) mucocoeles and differentiation between vital adipose tissue and fat necroses in the form of oil cysts. In difficult cases long-term MRI follow-up is necessary for definitive evaluation.

Adipose Tissue↗

[Prognostic factors in head-neck carcinomas].

Squamous cell carcinoma of the head and neck is one of the most common human cancers with an unchanged high rate of mortality despite improved diagnostic and therapeutic methods of the past twenty years. Latest advances of molecular biological methods contributed to the understanding of the multistep process of carcinogenesis. Genetic instability, dysregulation of cell cycle and apoptosis as well as changes of oncogenes and tumor suppressor genes are involved in carcinogenesis. So far, molecular markers do not fulfill the desired requirement of clinical relevance concerning early detection of cancer, estimation of prognosis and individualized therapy regimens in potential risk patients. With the establishment of the UICC TNM staging system first prognostic statements were made possible, which showed a positive correlation between tumor stage and prognosis. There is, however, a need of clinical and/or molecular parameters that reliably predict individual prognosis and results of individualized therapy. We discuss parameters that have been associated with prognosis of head and neck squamous cell carcinoma so far.

Biomarkers, Tumor↗

Long-term assessment of the wet precipitation chemistry in Austria (1984-1999).

The aim of the present study was to determine the long-time trends in concentrations and depositions of major ions in wet precipitation samples collected at 11 sampling sites from the Austrian precipitation chemistry network in the period 1984-1999. The analytical results were treated by the use of least square linear regression method. It is shown that a serious decrease of sulfate (between 30% and 60% for the period) and hydrogen ion (between 60% and 102% for the period) concentrations and depositions is achieved at almost all sampling sites and in most of these cases the linear trend proves to be statistically significant. Nitrogen containing ions and base cations do not reveal a distinct trend of changing and in the majority of the sites the linear models are not adequate. In principle, an overall slight concentration and deposition decrease for these major ions is observed (up to 30% for the period of observation) but some substantial exceptions are also found (site Haunsberg or site Lobau). The changes in chloride concentration and deposition, too, do not indicate significant linear trend and, in general, are decreasing for the period of monitoring. In order to give some explanation of the exceptional behaviour of some of the major ions in several sites, an additional comparison with Austrian emission data (sulfur dioxide, nitrogen oxides, ammonium) and with data from five EMEP sites from neighbouring countries is performed. A significant West-East trend of acidity increase is found as well as a good correlation with the emission trends. Therefore, both transboundary and specific local factors could be substantial factors in the wet precipitation chemistry in the region.

Austria↗

Investigation of bax, bcl-2, bcl-x and p53 gene polymorphisms in multiple sclerosis.

Clinical course, outcome, radiological features, severity, and histopathology are heterogenous in multiple sclerosis (MS). Since MS is considered to be a polygenic disease, the genetic background may at least partly be responsible for this variability. Some MS cases are histopathologically characterized by a dramatic oligodendrocyte loss that is in part caused by apoptosis. A dysregulated apoptotic elimination of self-reactive T cells may also contribute to disease susceptibility. To analyze genetic differences in the apoptosis regulating factors bcl-2, bax, bcl-x and p53 we investigated polymorphisms of these genes in 105 patients with a relapsing remitting disease course and 99 controls by PCR-SSCP and direct sequencing. We identified so far unpublished sequence alterations in the promotor region of the bxl-x gene, in exon 7 of the p53 gene, and in exon 1 of the bax gene. No differences were observed between MS patients and controls. Additional known polymorphisms were found in intron 3 of the bax gene and in exon 6 of the p53 gene. No significant differences in the frequency of gene sequence variations were found between MS patients and controls. The apoptosis genes studied here therefore appear less likely to be important effector genes in MS.

Apoptosis↗

An implementation of the HACCP system in the production of food-packaging material.

The Hazard Analysis Critical Control Point (HACCP) system according to the Codex Alimentarius model was applied to the processes of five paper and paperboard mills and four plants further converting paper or board intended for contact with foodstuffs. The generalised flow diagrams of the processes are presented. Each of the overall processes contained 40-150 process steps. Normally three to five sessions with HACCP teams and additional private negotiations were needed for each mill or plant. Hazards leading to critical control points (CCPs) were microbiological (handling/storage, circulation water, starch, process environment) and physical (process environment) in mills, and microbiological (storage, lacquers or glues, packaging and process environment), chemical (printing) and physical (storage of products, packaging and process environment) in plants. Specifications, critical limits (e.g., based on different kinds of reports and instructions), monitoring methods (microbiological and visual) and frequency, responsibilities and corrective actions of the processes are presented. Most of the improvements focused on improving the process environment. In five cases, hygiene training was included in the implementation of the HACCP system.

Food Packaging↗

Structure and on-site formation of biofilms in paper machine water flow.

Paper machine biofilms formed in situ on stainless steel surfaces were studied. A robust flow cell was fitted to side stream (1.8 m s(-1)) of the spray water circuit of a paper machine. This on-site tool allowed for assessing the efficacy of antifoulants and the adequacy of steel polishing under mill conditions. A rapid fluorescence-based assay was developed to quantify the biomass of shallow biofilms on machine steel. The fluorescence matched the ATP content measured for the same biofilms. Electrolytic polishing reduced the tendency of biofouling of 500 grit surface steel. Biofilm grew under machine conditions as clusters on the steels, showing uniformly coccoid, filaments or short rods; only one cell type in each cluster. The biofilm clusters excluded latex beads of 0.02 microm with hydrophilic or with hydrophobic surfaces from penetrating more than three to four layers of cells. Under the high hydraulic flow at the machine (1.8 m s(-1)), the biofilm grew in 7 days 6-10 microm thick. The high flow rate guided the shape of the biofilm clusters emerging after the primary attachment of cells. Adhered individual bacteria were the platform on steel to which solids such as paper machine fines then accumulated.

Bacterial Adhesion↗

[Reconstruction of hypopharynx after pharyngolaryngectomy with U-shaped radial forearm flap].

BACKGROUND: After pharyngolaryngectomy reconstructive procedures of the upper digestive tract are necessary. Since the introduction of microvascular tissue transplantation jejunal loops proved to be a versatile transplant. Nevertheless it has some disadvantages as i. e. the increased donor morbidity, a rather high sensitivity to hypoxia and the tendency of shrinkage and formation of stenosis. METHOD: We perform the reconstruction of the hypopharynx with the radial forearm flap. The fasciocutaneous flap is harvested on the radial artery in a size of 12 x 6 cm in average and is sutured U-shaped paramedian to the prevertebral fascia. In addition the posterior wall of the oesophagus and the oropharynx have to be adapted to the prevertebral fascia. RESULTS: Between 1997 and 2001 we performed these reconstructions in 20 patients. In one case we found a complete flap necrosis, which required secondary reconstruction with a pectoralis major flap. In 2 patients we saw a stenosis at the junction to the oesophagus, which was treated by revision surgery and bougienage. In 18 patients swallowing was regular. 6 patients were able to learn oesophageal speech. CONCLUSION: The radial forearm flap in its U-shaped transposition to the prevertebral fascia represents a functionally good reconstructive procedure for the hypopharynx.

Esophageal Neoplasms↗

[Teachers' health - a challenge for an interdisciplinary prevention concept].

The early retirement of teachers because of illness is presently a great social and sociomedical problem. In Bavaria, currently more than every second case of early retirement in the profession is the result of psychic or psychosomatic illness. The aim of all preventive measures must therefore be first of all the preservation or restoration of psychic health of teachers. With an underlying comprehensive biopsychosocial understanding of health and performance, preventive measures should take into consideration both circumstances and behaviour, as well as pathogenetic and salutogenetic aspects of the disease. The preventive concept developed under these premises is characterised by the terms interdisciplinary, multidimensional, integrative and institutionalised. Interdisciplinary means the concerted effort of all disciplines involved in the health of teachers. Multidimensional implies action at all levels of disease prevention and includes therapy and rehabilitation. Integrative stands for the formation of networks for optimising processes and the linking of interfaces in the sense of case/disability management. Institutionalised means the creation of structures for co-ordinating and controlling. In addition, potential areas of activity for those involved in prevention, in particular also occupational medicine, are described, resulting in an appeal that the insights gained may be translated into practical reality.

Germany↗

[Correlation of different types of emphysema in high-resolution computed tomography (HR-CT) with the ILO-classification of coal workers pneumoconiosis].

PURPOSE: The complaints of patients suffering from pneumoconiosis and the decrease in cardio-respiratory function tests are related to the major complications, emphysema or bronchitis, resp. to a lesser degree the complaints are directly influenced by the silicotic process itself. Up to now, no large study has analysed the correlation of different types and severity of emphysema with the ILO-classification of pneumoconiosis in miners. MATERIAL AND METHODS: In 104 miners the severity of pneumoconiosis was classified by ILO. By HR-CT the type and severity of emphysema was analysed using a 4-point-scale. The correlation of emphysema with the ILO-classification was tested with Pearson-correlation. RESULTS: The centrolobular emphysema was the dominant type with 59 %, but there was no dependence on the severity of pneumoconiosis. Only the paracicatricial emphysema had a significant correlation (p < 0.05) with the degree of large opacities. On the other hand, the paracicatricial emphysema was only detected in 32 %; under quantitative aspects it was seen to be less common than the centrolobular, the parapleural and the paraseptal emphysema (46 %). There was no significant correlation with the size and distribution of the small opacities and the different types of emphysema. CONCLUSIONS: Only the large opacities had a significant correlation with the appearance of paracicatricial emphysema. The other types of emphysema, especially, the dominant centrolobular type had no obvious association with pneumoconiosis. The multifactoral genesis of emphysema has to be taken into account.

Adult↗

Epinephrine and clonidine do not improve intrathecal sufentanil analgesia after total hip replacement.

BACKGROUND: We compared analgesia after intrathecal sufentanil alone, sufentanil with epinephrine 200 microg and sufentanil with clonidine 30 microg in patients after total hip replacement, the endpoints being onset and duration of action. METHODS: We performed a randomized double-blind study of 45 patients for elective total hip arthroplasty using continuous spinal anaesthesia. As soon as a pain score higher than 3 on a 10 cm visual analogue scale was reported, sufentanil 7.5 microg alone, sufentanil 7.5 microg + epinephrine 200 microg or sufentanil 7.5 microg + clonidine 30 micro g in 2 ml normal saline was given intrathecally. Pain scores, rescue analgesia (diclofenac and morphine) and adverse effects (respiratory depression, postoperative nausea and vomiting, itching) were observed for 24 h after surgery. RESULTS: Time to a pain score of <3 [6 (SD 1) vs 6 (1) vs 5 (1) min], time to the lowest pain score [7 (2) vs 8 (2) vs 8 (2) min] and time to the first dose of systemic analgesic for a pain score >3 [281 (36) vs 288 (23) vs 305 (30) min] were similar in all three groups. Adverse effects and analgesic requirements during the first 24 h were also similar. CONCLUSION: After total hip replacement, all three analgesic regimens gave good analgesia with comparable onset and duration of action, and minor adverse effects.

Aged↗