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Biomedical subjects

W Mann

Publications and source records attributed to W Mann.

At least 19 recordsLinked to original sources
PubMed2001

Factors associated with home environmental problems among community-living older people.

PURPOSE: This paper describes the types of difficulties older people have with their home environments and the factors associated with having such difficulties. METHOD: Data were used from 296 study participants of the University at Buffalo's Consumer Assessments Study that examines the home modification needs and environmental difficulties of older people. A combination of socio-demographic variables, health and functional status indicators and measures of psychosocial well-being were used to predict environmental problems. RESULTS: An average of 13 problems with the environment that posed as a barrier to safe and independent performance was observed in homes. It was found that most difficulties occurred in bathrooms, kitchens, bedrooms and access to entryways and rooms. Hierarchical multiple regression analysis showed that having home environmental problems was most strongly associated with younger age, being female, being of minority status, having pain, and greater physical disability. CONCLUSION: The findings show that a combination of conditions that include demographic and functional conditions place older people at risk for problems with the home environment that impede performance of daily living activities.

Activities of Daily Living↗
PubMed2001

Detection of mitochondrial single nucleotide polymorphisms using a primer elongation reaction on oligonucleotide microarrays.

We have developed a novel allele-specific primer elongation protocol using a DNA polymerase on oligonucleotide chips. Oligonucleotide primers carrying polymorphic sites at their free 3'end were covalently bound to glass slides. The generation of single-stranded targets of genomic DNA containing single nuclotide polymorphisms (SNPs) to be typed was achieved by an asymmetric PCR reaction or exonuclease treatment of phosphothioate (PTO)-modified PCR products. In the presence of DNA polymerase and all four dNTPs, with Cy3-dUTP replacing dTTP, allele-specific extension of the immobilized primers took place along a stretch of target DNA sequence. The yield of elongated products was increased by repeated reaction cycles. We performed multiplexed assays with many small DNA targets, or used single targets of up to 4.4 kb mitochondrial DNA (mtDNA) sequence to detect multiple SNPs in one reaction. The latter approach greatly simplifies preamplification of SNP-containing regions, thereby providing a framework for typing hundreds of mtDNA polymorphisms.

Alleles↗
PubMed2001

X chromosome-specific cDNA arrays: identification of genes that escape from X-inactivation and other applications.

Mutant alleles are frequently characterized by low expression levels. Therefore, cDNA array-based gene expression profiling may be a promising strategy for identifying gene defects underlying monogenic disorders. To study the potential of this approach, we have generated an X chromosome-specific microarray carrying 2423 cloned cDNA fragments, which represent up to 1317 different X-chromosomal genes. As a prelude to testing cell lines from patients with X-linked disorders, this array was used as a hybridization probe to compare gene expression profiles in lymphoblastoid cell lines from normal males, females and individuals with supernumerary X chromosomes. Measurable hybridization signals were obtained for more than half of the genes represented on the chip. A total of 53 genes showed elevated expression levels in cells with multiple X chromosomes and many of these were found to escape X-inactivation. Moreover, the detection of a male-viable deletion encompassing three genes illustrates the utility of this array for the identification of small unbalanced chromosome rearrangements.

Alleles↗
PubMed2001

[Epithelium-stroma interaction in cholesteatoma of the middle ear].

BACKGROUND: Local Infiltration and bony destruction are characteristic features of cholesteatomas. The aim of the study was assessment of cell ploidy, proliferation rates and expression of cell adhesion molecules to analyze the pathogenetic role of matrix (epithelium) in cholesteatoma. The cellbiologic parameters were compared to clinical findings. PATIENTS AND METHOD: Tissue samples from 48 patients with cholesteatomas were analyzed by: routine histology, quantitative DNA-cytometry with the DNA indices: 2cDeviation Index (2cDI) and 5c Exceeding Rate (5c ER), immunhistochemical analysis of proliferation rate (ki67-MIB1 and PCNA), cell adhesion molecules, cell-cell interaction: E-Cadherin, alpha 1 beta 6-Integrin, Inter-Cellular-Adhesion-Molecule (I-CAM), cell-matrix interaction: CD44v4/5, CD 44v6, alpha v-, beta 3-Integrinchains and vascular-Cell-Adhesion-Molecule (V-CAM). Clinical data included patient age, history of ear disease, pre-operative audiometry, intra-operative size and extension of the cholesteatoma, destruction of ossicles and petrous bone. For comparison healthy squamous epithelium was obtained from the external ear canal of 10 patients during stapes surgery. RESULTS: Ossicular destructions were found in 34 cases. Three patients had mesotympanic cholesteatomas, four patients had mesotympanic and epitympanic involvement. In 37 patients cholesteatomas extended into the mastoid and in four patients the perilabyrinth and the petrous apex were reached. DNA-cytometric examination of matrix showed normal diploid values and no aneuploid cells (DNA-content > 5c) in all patients. The proliferation rates of the matrix were increased in comparison to normal epithelium. Cell adhesion molecules for intercellular bindings were expressed in similar pattern in cholesteatomas and in normal epithelium. Cell adhesion molecules for cell matrix bindings showed new or increased expression in cholesteatomas. No significant correlation between proliferation and clinical findings could be established. CONCLUSION: The study confirms previous suggestions that the growth of cholesteatomas is not stimulated by the matrix. The increased proliferation of the matrix is a result of the inflammatory process in the cholesteatoma and is correlated to the size of the cholesteatoma. On a cellular or molecular level no correlation between bone destruction through the cholesteatoma and proliferation rate of the cholesteatomas could be established. These findings support suggestions that the perimatrix of the cholesteatomas is the main pathogenetic factor.

Adolescent↗
PubMed2001

The expression of cathepsins in osteoclast-like giant cells of an anaplastic thyroid carcinoma with tracheal perforation.

Anaplastic carcinoma of the thyroid gland (ACT) is a rapidly growing neoplasm with a very poor prognosis. In this study, we examined an ACT with osteoclast-like giant cells expressing matrix--degrading cysteine proteinases and their endogeneous inhibitor cystatin C. Bronchoscopic evaluation of a 50-year-old man suffering from hoarseness, dysphagia, and dyspnea revealed an irregular tumor mass infiltrating into the trachea and the cricothyroid ligament region. On histological examination, a necrotizing undifferentiated anaplastic carcinoma with osteoclast-like giant cells was detected. An immunohistochemical study of the tumor tissue was performed using a panel of 15 antibodies, including double labeling techniques. Most of the osteoclast-like multinucleated giant cells (MGC) expressed CD68 and cathepsin K. Colocalization of cathepsin B and its endogenous inhibitor cystatin C occurred in the majority of MGC. Mononuclear cells (MC) were positive for cathepsin B, cystatin C, and CD 68, but only faintly for cathepsin K. Expression of cathepsins B and K in the MGC of the ACT might contribute to the invasive behavior of this tumor, thus promoting metastatic ability and destruction of the cartilagenous trachea.

Biomarkers, Tumor↗
PubMed2000

Immuno-electron microscopic localization of the alpha(1) and beta(1)-subunits of soluble guanylyl cyclase in the guinea pig organ of corti.

Guanylyl cyclases (GC) catalyze the formation of the intracellular signal molecule cyclic GMP from GTP. For some years it has been known that the heme-containing soluble guanylyl cyclase (sGC) is stimulated by NO and NO-containing compounds. The sGC enzyme consists of two subunits (alpha(1) and beta(1)). In the present study, the alpha(1) and beta(1)-subunits were identified in the guinea pig cochlea at the electron microscopic level using a post-embedding immuno-labeling procedure. Ultrathin sections of LR White embedded specimens were incubated with various concentrations of two rabbit polyclonal antibodies to the alpha(1)- and beta(1)-subunit, respectively. The immunoreactivity was visualized by a gold-labeled secondary antibody in an energy-filtering transmission electron microscope (EFTEM). Marked immunoreactivity for both antibodies was found in the inner and outer hair cells, with numerous gold particles at the border of the cuticular plates, associated with the cell nuclei or attached to electron-dense parts of the cytoplasm. In the pillar cells and apical Deiters cells, soluble guanylyl cyclase immunoreactivity was located at the rim of the cuticular plates and between the microtubuli bundles. Together with the recently identified nitric oxide synthase isoforms [Eur. Arch. Otorhinolaryngol. 254 (1997) 396; Eur. Arch. Otorhinolaryngol. 255 (1998) 483], the soluble guanylyl cyclase may be involved in signalling processes in the organ of Corti.

Animals↗
PubMed2000

[Vascular origin of cerebellopontine angle syndrome].

INTRODUCTION: The seventh and eighth cranial nerves course toward the internal auditory canal within the cerebellopontine angle. Lesions in this region are usually related to malfunctions of these cranial nerves. Although an acoustic schwannoma is one of the main etiologies of cerebellopontine angle pathology, various inflammatory processes and vascular anomalies even though rare must be considered. PATIENTS/METHODS: We describe 5 cases with vascular loops of the basilar or vertebral arteries as a possible cause for hearing loss, vertigo and pulsatile tinnitus. In two cases the vascular lesion was confirmed at surgery, in which a decompression procedure was performed. The work-up for each patient included an auditory test battery and electronystagmography. Imaging studies included MRI and angiography in two cases. RESULTS/CONCLUSIONS: Our experiences show that while the cerebellopontine angle syndrome is mostly caused by benign tumors an abnormal vascular loop has to be considered in any differential diagnosis.

Adult↗
PubMed2000

Virtual endoscopy of the inner ear and the auditory canal.

To assess the role of virtual endoscopy (VE) in the examination of intracisternal structures and of the inner ear, we studied the anatomy of the labyrinth and internal auditory canal using the original CT slices and VE on the unaffected side in three female and three male patients, age range 3-46 years, with contralateral retrocochlear hearing loss. We also examined seven patients with different pathological findings. VE was performed using an advanced postprocessing program with high-resolution 3D data sets of CT (1-1.5 mm thickness, pitch 1.25) and MRI-CISS-3D (constructive interference in steady state) images of the basal cisterns (1.5 T, slice thickness 0.7-1 mm). VE provides an endoscopic-like view from a given point within the basal cisterns of vessels and nerves (on MRI) or of the structures of the inner ear (on CT). The complex anatomy and pathological changes in the inner ear can be faithfully shown. The main advantage is not basic diagnostic information but demonstration of topographically complex situations, such as the canalicular system of the inner ear, for discussion, preoperative planning and teaching.

Adolescent↗
PubMed2000

[Self-expanding nitinol stents in proximal tracheal stenosis].

UNLABELLED: The use of silicone- or metal stents in stenosis of the distal trachea and the bronchial system is a customary procedure [1-4], for example after tumor invasion or cicatricial stenosis after transplantation. In the proximal part of the trachea, on smaller, short and soft strictures we try to stabilise the trachea by the implantation of rings. Other methods are tracheal plasty or transverse tracheal resectomy [5-7]. In the case of longer or nearer subglottal stenoses the positioning of self-expanding nitinol stents has proven a simple, gentle and well-tolerated alternative procedure even in very serious disorders [1, 8, 9]. METHOD: These stents can be placed in short narcosis under endoscopic control without great strain on the patient. RESULTS: We placed nitinol-stents in the proximal part of the trachea in eleven cases. In five cases dyspnoea caused by a tracheal collapse improved. In two further cases a tracheal stenosis with massive granulation tissue and cicatricial pull under an inlaid tracheal cannula was removed and the tracheostoma was closed. In four cases a solid, scarred and cartilaginous stenosis in the area of the cricoid and the upper tracheal rings was widened with laser and later on stented. CONCLUSION: Over an observation time of two years no complications showed safe one case in which a directly postoperative dislocation was repositioned quickly. The patients live without restrictions through the tracheal stenosis or a tracheostoma. In the best possible case epithelialization over the metal meshes develops so that a nearly normal mucus transportation is possible [1, 10-12].

Adult↗
PubMed2000

[Therapy of hyperacusis in patients with tinnitus].

BACKGROUND: Patients with tinnitus very often suffer from hyperacusis also. METHODS AND PATIENTS: In the present study a possible treatment for patients with bilateral hyperacusis is introduced and the therapeutical results of 41 patients suffering from bilateral hyperacusis combined with a uni- or bilateral tinnitus are discussed. Twenty-one of them also had a cochlear hearing loss. By means of white noise generators or hearing aids and a specific acoustic training the auditory input to the central nervous system was increased. All patients were taught a method to reduce stress (Progressive muscle relaxation according to Jacobson). Uncomfortable loudness levels were analysed before as well as 3 weeks and 6 months after beginning of the treatment. RESULTS: By the time of 3 weeks the discomfort from ordinary sounds was distinctly reduced and the reduction progressed further after 6 months of treatment. In more than 50% of the participants the uncomfortable loudness levels could be raised to a normal range. Interestingly the improvement of hyperacusis was independent of an existing hearing loss. CONCLUSIONS: The described method of treatment seems to be helpful for patients with hyperacusis and will be compared to other therapeutical regimes.

Acoustics↗
PubMed1999

Influence of resin-based restoration materials on cytotoxicity in gingival fibroblasts.

Tooth-colored resin-based restoration materials have gained enormous significance in recent decades. Since the composites presently available still evidence various weaknesses, intensive research continues concerning them. In this study we tested the biocompatibility of six resin-based materials (Charisma, Solitaire, Definite, Tetric ceram, Ariston pHc and Compoglass) by means of cultured human gingival fibroblasts. Over a period of 9 days the cured resin-based materials were incubated with the fibroblasts. Cell growth, cell viability, and protein content was measured. The release of prostaglandin (PGE subset2) was also determined. There was a reduction of cell functions, related to the different resin-based materials. Protein content of the fibroblasts was significantly reduced (Kruskal Wallis test; p = 0.0001), depending on the material tested. Definite induced only minimal irritation, and there was correspondingly little contrast to the protein content of the controls. Solitaire induced the highest levels of irritation and the greatest reduction in protein content. Lactate production of fibroblasts also showed some significant reduction in contact with particular materials (p = 0.005). There were only small differences among the tested materials as concerns measured PGE subset2 release of the fibroblasts. The data suggest that the methods here employed may be quite useful in testing the cytotoxic potential of newly developed resin-based materials

Cell Division↗
PubMed1999

Optic nerve decompression in trauma and tumor patients.

Optic nerve decompression is a procedure that is now receiving increasing clinical attention. However, there are currently no standardized treatment protocols in the therapy of traumatic or pressure insults to the nerve. The present retrospective study was designed to report our experience with microscopic endonasal transethmoid-sphenoid optic nerve decompression in 24 unilateral trauma cases and 11 unilateral skull base tumor patients. In general preoperative visual acuities in the trauma patients were worse than in the tumor patients. Following surgery, 9 of 11 tumor patients (82%) had at least some improvement of their vision, including 5 complete recoveries. In the group with traumatic visual impairment, 16 of the patients had no light perception preoperatively. Postoperatively, 13 patients (54%) had at least some improvement, with 4 patients regaining normal or near normal vision. Compared to other techniques and approaches, our technique is a minimally invasive procedure for optic nerve decompression, reducing unnecessary operative trauma to nasal structures, skin incisions or even craniotomy and frontal lobe retraction.

Adult↗
PubMed1999

The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions.

OBJECTIVES: Irritating effects of organic solvents have usually been measured by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating effects. METHODS: Twelve healthy, non-smoking students were exposed to 200 ppm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a crossover design. The amounts of interleukins (IL)-1beta, IL-6 and IL-8 and prostaglandin E(2) (PGE(2)) in nasal secretions were measured. Mucociliary transport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast microscopy. Subjective symptoms were assessed by questionnaire. RESULTS: Concentrations of ILs were significantly elevated after exposure to 200 ppm 1,1,1-trichloroethane (IL-1beta 82.4 vs. 28.8 pg/ml (medians), P=0.003; IL-6 12.2 vs. 7.2 pg/ml, P=0. 01; IL-8 549 vs. 424 pg/ml, P=0.007), whereas the other parameters remained unchanged. CONCLUSION: The interleukins measured proved to be sensitive indicators of irritating effects of 1,1, 1-trichloroethane. The German threshold limit (MAK value) of 200 ppm 1,1,1-trichloroethane does not prevent the subclinical inflammation of nasal mucosa.

Adult↗
PubMed1999

The effect of short-term immunotherapy with molecular standardized grass and rye allergens on eosinophil cationic protein and tryptase in nasal secretions.

BACKGROUND: Activation of mast cells and eosinophils under pollen exposure can be inhibited by specific immunotherapy. OBJECTIVE: The effect of short-term immunotherapy with 7 preseasonal injections of molecular standardized allergens from grass and rye pollen on eosinophil cationic protein (ECP) and tryptase levels in nasal secretions has been compared with symptomatic drug treatment in an open, randomized study with 48 patients. METHODS: Nasal reactivity and mediator levels in nasal secretions were measured at baseline, before season, in season, and after season. RESULTS: Symptom scores in the immunotherapy group were 134.5 (95% CI, 65 to 336) versus 386. 0 (95% CI, 185 to 563), significantly lower as in the drug-treated group. ECP and tryptase levels increased significantly during natural allergen exposition. The seasonal levels in the immunotherapy group were significantly lower than in the drug-treated group with 272.1 ng/mL (252.0 to 293.9 ng/mL; immunotherapy) versus 470.4 ng/mL (SEM, 435.6 to 508.0 ng/mL; drugs) for ECP and with 8.73 ng/mL (SEM, 8.20 to 9.29 ng/mL) versus 17.47 ng/mL (16.42 to 18.60 ng/mL) for tryptase (all, P <.001). The ECP level induced by nasal provocation was 105.6 ng/mL (99.0 to 112.6 ng/mL) versus 180.4 ng/mL (169.2 to 192.4 ng/mL), significantly lower (P <.001) in the immunotherapy group, as was the tryptase level with 12.12 ng/mL (11.53 to 12.75 ng/mL) versus 8.19 ng/mL (7. 79 to 8.62 ng/mL; P <.001) at the after-season visit. CONCLUSION: Short-term immunotherapy is able to reduce tryptase and ECP in nasal secretions more effectively than drug treatment in patients with allergic rhinitis.

Adolescent↗
PubMed1999

Neuroradiological diagnosis in thyroid-associated orbitopathy.

No renunciation can be made of modern imaging techniques in primary diagnosis as well as in the course of endocrine orbitopathy. Even in times of cost reduction of the public health and although expansive CT and MR play a constant role in the interdisciplinary challenge, concerning the treatment of these patients. Both methods show the actual objective morphological findings, MR giving additional information concerning the acuteness (T2 relaxation time) or chronicity (fatty degeneration), which is of great importance for the chosen therapy. CT and MR is mandatory for the control of the clinical course after conservative, surgical and/or radiotherapeutic therapy.

Graves Disease↗