8 resultados para laryngeal mask

em Helda - Digital Repository of University of Helsinki


Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this work was to examine how breathing, swallowing and voicing are affected in different laryngeal disorders. For this purpose, we examined four different patient groups: patients who had undergone total laryngectomy, anterior cervical decompression (ACD), or injection laryngoplasty with autologous fascia (ILAF), and patients with dyspnea during exercise. We studied the problems and benefits related to the automatic speech valve used for the rehabilitation of speech in laryngectomized patients. The device was given to 14 total laryngectomized patients who used the traditional valve especially well. The usefulness of voice and intelligibility of speech were assessed by speech pathologists. The results demonstrated better performance with the traditional valve in both dimensions. Most of the patients considered the automatic valve a helpful additional device but because of heavier breathing and the greater work needed for speech production, it was not suitable as a sole device in speech rehabilitation. Dysphonia and dysphagia are known complications of ACD. These symptoms are caused due to the stretching of tissue needed during the surgery, but the extent and the recovery from them was not well known before our study. We studied two patient groups, an early group with 50 patients who were examined immediately before and after the surgery and a late group with 64 patients who were examined 3 9 months postoperatively. Altogether, 60% reported dysphonia and 69% dysphagia immediately after the operation. Even though dysphagia and dysphonia often appeared after surgery, permanent problems seldom occurred. Six (12 %) cases of transient and two (3 %) permanent vocal cord paresis were detected. In our third study, the long-term results of ILAF in 43 patients with unilateral vocal cord paralysis were examined. The mean follow-up was 5.8 years (range 3 10). Perceptual evaluation demonstrated improved results for voice quality, and videostroboscopy revealed complete or partial glottal closure in 83% of the patients. Fascia showed to be a stable injection material with good vocal results. In our final study we developed a new diagnostic method for exertional laryngeal dyspnea by combining a cardiovascular exercise test with simultaneous fiberoptic observation of the larynx. With this method, it is possible to visualize paradoxal closure of the vocal cords during inspiration, which is a diagnostic criterion for vocal cord dysfunction (VCD). We examined 30 patients referred to our hospital because of suspicion of exercise-induced vocal cord dysfunction (EIVCD). Twenty seven out of thirty patients were able to perform the test. Dyspnea was induced in 15 patients, and of them five had EIVCD and four high suspicion of EIVCD. With our test it is possible to set an accurate diagnosis for exertional laryngeal dyspnea. Moreover, the often seen unnecessary use of asthma drugs among these patients can be avoided.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In epithelial-mesenchymal transition (EMT), epithelial cells acquire traits typical for mesenchymal cells, dissociate their cell-cell junctions and gain the ability to migrate. EMT is essential during embryogenesis, but may also mediate cancer progression. Basement membranes are sheets of extracellular matrix that support epithelial cells. They have a major role in maintaining the epithelial phenotype and, in cancer, preventing cell migration, invasion and metastasis. Laminins are the main components of basement membranes and may actively contribute to malignancy. We first evaluated the differences between cell lines obtained from oral squamous cell carcinoma and its recurrence. As the results indicated a change from epithelial to fibroblastoid morphology, E-cadherin to N-cadherin switch, and change in expression of cytokeratins to vimentin intermediate filaments, we concluded that these cells had undergone EMT. We further induced EMT in primary tumour cells to gain knowledge of the effects of transcription factor Snail in this cell model. The E-cadherin repressors responsible for the EMT in these cells were ZEB-1, ZEB-2 and Snail, and ectopic expression of Snail was able to augment the levels of ZEB-1 and ZEB-2. We produced and characterized two monoclonal antibodies that specifically recognized Snail in cell lines and patient samples. By immunohistochemistry, Snail protein was found in mesenchymal tissues during mouse embryonal development, in fibroblastoid cells of healing skin wounds and in fibromatosis and sarcoma specimens. Furthermore, Snail localized to the stroma and borders of tumour cell islands in colon adenocarcinoma, and in laryngeal and cervical squamous cell carcinomas. Immunofluorescence labellings, immunoprecipitations and Northern and Western blots showed that EMT induced a progressive downregulation of laminin-332 and laminin-511 and, on the other hand, an induction of mesenchymal laminin-411. Chromatin immunoprecipitation revealed that Snail could directly bind upstream to the transcription start sites of both laminin α5 and α4 chain genes, thus regulating their expression. The levels of integrin α6β4, a receptor for laminin-332, as well as the hemidesmosomal complex proteins HD1/plectin and BP180 were downregulated in EMT-experienced cells. The expression of Lutheran glycoprotein, a specific receptor for laminin-511, was diminished, whereas the levels of integrins α6β1 and α1β1 and integrin-linked kinase were increased. In quantitative cell adhesion assays, the cells adhered potently to laminin-511 and fibronectin, but only marginally to laminin-411. Western blots and immunoprecipitations indicated that laminin-411 bound to fibronectin and could compromise cell adhesion to fibronectin in a dose-dependent manner. EMT induced a highly migratory and invasive tendency in oral squamous carcinoma cells. Actin-based adhesion and invasion structures, podosomes and invadopodia, were detected in the basal cell membranes of primary tumour and spontaneously transformed cancer cells, respectively. Immunofluorescence labellings showed marked differences in their morphology, as podosomes organized a ring structure with HD1/plectin, αII-spectrin, talin, focal adhesion kinase and pacsin 2 around the core filled with actin, cortactin, vinculin and filamin A. Invadopodia had no division between ring and core and failed to organize the ring proteins, but instead assembled tail-like, narrow actin cables that showed a talin-tensin switch. Time-lapse live-cell imaging indicated that both podosomes and invadopodia were long-lived entities, but the tails of invadopodia vigorously propelled in the cytoplasm and were occasionally released from the cell membrane. Invadopodia could also be externalized outside the cytoplasm, where they still retained the ability to degrade matrix. In 3D confocal imaging combined with in situ gelatin zymography, the podosomes of primary tumour cells were large, cylindrical structures that increased in time, whereas the invadopodia in EMT-driven cells were smaller, but more numerous and degraded the underlying matrix in significantly larger amounts. Fluorescence recovery after photobleaching revealed that the substructures of podosomes were replenished more rapidly with new molecules than those of invadopodia. Overall, our results indicate that EMT has a major effect on the transcription and synthesis of both intra- and extracellular proteins, including laminins and their receptors, and on the structure and dynamics of oral squamous carcinoma cells.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Microarrays have a wide range of applications in the biomedical field. From the beginning, arrays have mostly been utilized in cancer research, including classification of tumors into different subgroups and identification of clinical associations. In the microarray format, a collection of small features, such as different oligonucleotides, is attached to a solid support. The advantage of microarray technology is the ability to simultaneously measure changes in the levels of multiple biomolecules. Because many diseases, including cancer, are complex, involving an interplay between various genes and environmental factors, the detection of only a single marker molecule is usually insufficient for determining disease status. Thus, a technique that simultaneously collects information on multiple molecules allows better insights into a complex disease. Since microarrays can be custom-manufactured or obtained from a number of commercial providers, understanding data quality and comparability between different platforms is important to enable the use of the technology to areas beyond basic research. When standardized, integrated array data could ultimately help to offer a complete profile of the disease, illuminating mechanisms and genes behind disorders as well as facilitating disease diagnostics. In the first part of this work, we aimed to elucidate the comparability of gene expression measurements from different oligonucleotide and cDNA microarray platforms. We compared three different gene expression microarrays; one was a commercial oligonucleotide microarray and the others commercial and custom-made cDNA microarrays. The filtered gene expression data from the commercial platforms correlated better across experiments (r=0.78-0.86) than the expression data between the custom-made and either of the two commercial platforms (r=0.62-0.76). Although the results from different platforms correlated reasonably well, combining and comparing the measurements were not straightforward. The clone errors on the custom-made array and annotation and technical differences between the platforms introduced variability in the data. In conclusion, the different gene expression microarray platforms provided results sufficiently concordant for the research setting, but the variability represents a challenge for developing diagnostic applications for the microarrays. In the second part of the work, we performed an integrated high-resolution microarray analysis of gene copy number and expression in 38 laryngeal and oral tongue squamous cell carcinoma cell lines and primary tumors. Our aim was to pinpoint genes for which expression was impacted by changes in copy number. The data revealed that especially amplifications had a clear impact on gene expression. Across the genome, 14-32% of genes in the highly amplified regions (copy number ratio >2.5) had associated overexpression. The impact of decreased copy number on gene underexpression was less clear. Using statistical analysis across the samples, we systematically identified hundreds of genes for which an increased copy number was associated with increased expression. For example, our data implied that FADD and PPFIA1 were frequently overexpressed at the 11q13 amplicon in HNSCC. The 11q13 amplicon, including known oncogenes such as CCND1 and CTTN, is well-characterized in different type of cancers, but the roles of FADD and PPFIA1 remain obscure. Taken together, the integrated microarray analysis revealed a number of known as well as novel target genes in altered regions in HNSCC. The identified genes provide a basis for functional validation and may eventually lead to the identification of novel candidates for targeted therapy in HNSCC.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

During the last 10-15 years interest in mouse behavioural analysis has evolved considerably. The driving force is development in molecular biological techniques that allow manipulation of the mouse genome by changing the expression of genes. Therefore, with some limitations it is possible to study how genes participate in regulation of physiological functions and to create models explaining genetic contribution to various pathological conditions. The first aim of our study was to establish a framework for behavioural phenotyping of genetically modified mice. We established comprehensive battery of tests for the initial screening of mutant mice. These included tests for exploratory and locomotor activity, emotional behaviour, sensory functions, and cognitive performance. Our interest was in the behavioural patterns of common background strains used for genetic manipulations in mice. Additionally we studied the behavioural effect of sex differences, test history, and individual housing. Our findings highlight the importance of careful consideration of genetic background for analysis of mutant mice. It was evident that some backgrounds may mask or modify the behavioural phenotype of mutants and thereby lead to false positive or negative findings. Moreover, there is no universal strain that is equally suitable for all tests, and using different backgrounds allows one to address possible phenotype modifying factors. We discovered that previous experience affected performance in several tasks. The most sensitive traits were the exploratory and emotional behaviour, as well as motor and nociceptive functions. Therefore, it may be essential to repeat some of the tests in naïve animals for assuring the phenotype. Social isolation for a long time period had strong effects on exploratory behaviour, but also on learning and memory. All experiments revealed significant interactions between strain and environmental factors (test history or housing condition) indicating genotype-dependent effects of environmental manipulations. Several mutant line analyses utilize this information. For example, we studied mice overexpressing as well as those lacking extracellular matrix protein heparin-binding growth-associated molecule (HB-GAM), and mice lacking N-syndecan (a receptor for HB-GAM). All mutant mice appeared to be fertile and healthy, without any apparent neurological or sensory defects. The lack of HB-GAM and N-syndecan, however, significantly reduced the learning capacity of the mice. On the other hand, overexpression of HB-GAM resulted in facilitated learning. Moreover, HB-GAM knockout mice displayed higher anxiety-like behaviour, whereas anxiety was reduced in HB-GAM overexpressing mice. Changes in hippocampal plasticity accompanied the behavioural phenotypes. We conclude that HB-GAM and N-syndecan are involved in the modulation of synaptic plasticity in hippocampus and play a role in regulation of anxiety- and learning-related behaviour.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Well-known risk factors include tobacco smoking and alcohol consumption. Overall survival has improved, but is still low especially in developing countries. One reason for this is the often advanced stage of the disease at the time of diagnosis, but also lack of reliable prognostic tools to enable individualized patient treatment to improve outcome. To date, the TNM classification still serves as the best disease evaluation criterion, although it does not take into account the molecular basis of the tumor. The need for surrogate molecular markers for more accurate disease prediction has increased research interests in this field. We investigated the prevalence, physical status, and viral load of human papillomavirus (HPV) in HNSCC to determine the impact of HPV on head and neck carcinogenesis. The prevalence and genotyping of HPV were assessed with an SPF10 PCR microtiter plate-based hybridization assay (DEIA), followed by a line probe-based genotyping assay. More than half of the patients had HPV DNA in their tumor specimens. Oncogenic HPV-16 was the most common type, and coinfections with other oncogenic and benign associated types also existed. HPV-16 viral load was unevenly distributed among different tumor sites; the tonsils harbored significantly greater amounts of virus than other sites. Episomal location of HPV-16 was associated with large tumors, and both integrated and mixed forms of viral DNA were detected. In this series, we could not show that the presence of HPV DNA correlated with survival. In addition, we investigated the prevalence and genotype of HPV in laryngeal carcinoma patients in a prospective Nordic multicenter study based on fresh-frozen laryngeal tumor samples to determine whether the tumors were HPV-associated. These patients were also examined and interviewed at diagnosis for known risk factors, such as tobacco smoking and alcohol consumption, and for several other habituations to elucidate their effects on patient survival. HPV analysis was performed with the same protocols as in the first study. Only 4% of the specimens harbored HPV DNA. Heavy drinking was associated with poor survival. Heavy drinking patients were also younger than nonheavy drinkers and had a more advanced stage of disease at diagnosis. Heavy drinkers had worse oral hygiene than nonheavy drinkers; however, poor oral hygiene did not have prognostic significance. History of chronic laryngitis, gastroesophageal reflux disease, and orogenital sex contacts were rare in this series. To clarify why vocal cord carcinomas seldom metastasize, we determined tumor lymph vessel (LVD) and blood vessel (BVD) densities in HNSCC patients. We used a novel lymphatic vessel endothelial marker (LYVE-1 antibody) to locate the lymphatic vessels in HNSCC samples and CD31 to detect the blood microvessels. We found carcinomas of the vocal cords to harbor less lymphatic and blood microvessels than carcinomas arising from sites other than vocal cords. The lymphatic and blood microvessel densities did not correlate with tumor size. High BVD was strongly correlated with high LVD. Neither BVD nor LVD showed any association with survival in our series. The immune system plays an important role in tumorigenesis, as neoplastic cells have to escape the cytotoxic lymphocytes in order to survive. Several candidate HLA class II alleles have been reported to be prognostic in cervical carcinomas, an epithelial malignancy resembling HNSCC. These alleles may have an impact on head and neck carcinomas as well. We determined HLA-DRB1* and -DQB1* alleles in HNSCC patients. Healthy organ donors served as controls. The Inno-LiPA reverse dot-blot kit was used to identify alleles in patient samples. No single haplotype was found to be predictive of either the risk for head and neck cancer, or the clinical course of the disease. However, alleles observed to be prognostic in cervical carcinomas showed a similar tendency in our series. DRB1*03 was associated with node-negative disease at diagnosis. DRB1*08 and DRB1*13 were associated with early-stage disease; DRB1*04 had a lower risk for tumor relapse; and DQB1*03 and DQB1*0502 were more frequent in controls than in patients. However, these associations reached only borderline significance in our HNSCC patients.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In meteorology, observations and forecasts of a wide range of phenomena for example, snow, clouds, hail, fog, and tornados can be categorical, that is, they can only have discrete values (e.g., "snow" and "no snow"). Concentrating on satellite-based snow and cloud analyses, this thesis explores methods that have been developed for evaluation of categorical products and analyses. Different algorithms for satellite products generate different results; sometimes the differences are subtle, sometimes all too visible. In addition to differences between algorithms, the satellite products are influenced by physical processes and conditions, such as diurnal and seasonal variation in solar radiation, topography, and land use. The analysis of satellite-based snow cover analyses from NOAA, NASA, and EUMETSAT, and snow analyses for numerical weather prediction models from FMI and ECMWF was complicated by the fact that we did not have the true knowledge of snow extent, and we were forced simply to measure the agreement between different products. The Sammon mapping, a multidimensional scaling method, was then used to visualize the differences between different products. The trustworthiness of the results for cloud analyses [EUMETSAT Meteorological Products Extraction Facility cloud mask (MPEF), together with the Nowcasting Satellite Application Facility (SAFNWC) cloud masks provided by Météo-France (SAFNWC/MSG) and the Swedish Meteorological and Hydrological Institute (SAFNWC/PPS)] compared with ceilometers of the Helsinki Testbed was estimated by constructing confidence intervals (CIs). Bootstrapping, a statistical resampling method, was used to construct CIs, especially in the presence of spatial and temporal correlation. The reference data for validation are constantly in short supply. In general, the needs of a particular project drive the requirements for evaluation, for example, for the accuracy and the timeliness of the particular data and methods. In this vein, we discuss tentatively how data provided by general public, e.g., photos shared on the Internet photo-sharing service Flickr, can be used as a new source for validation. Results show that they are of reasonable quality and their use for case studies can be warmly recommended. Last, the use of cluster analysis on meteorological in-situ measurements was explored. The Autoclass algorithm was used to construct compact representations of synoptic conditions of fog at Finnish airports.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Atomic layer deposition (ALD) is a method to deposit thin films from gaseous precursors to the substrate layer-by-layer so that the film thickness can be tailored with atomic layer accuracy. Film tailoring is even further emphasized with selective-area ALD which enables the film growth to be controlled also on the substrate surface. Selective-area ALD allows the decrease of a process steps in preparing thin film devices. This can be of a great technological importance when the ALD films become into wider use in different applications. Selective-area ALD can be achieved by passivation or activation of a surface. In this work ALD growth was prevented by octadecyltrimethoxysilane, octadecyltrichlorosilane and 1-dodecanethiol SAMs, and by PMMA (polymethyl methacrylate) and PVP (poly(vinyl pyrrolidone) polymer films. SAMs were prepared from vapor phase and by microcontact printing, and polymer films were spin coated. Microcontact printing created patterned SAMs at once. The SAMs prepared from vapor phase and the polymer mask layers were patterned by UV lithography or lift-off process so that after preparation of a continuous mask layer selected areas of them were removed. On these areas the ALD film was deposited selectively. SAMs and polymer films prevented the growth in several ALD processes such as iridium, ruthenium, platinum, TiO2 and polyimide so that the ALD films did grow only on areas without SAM or polymer mask layer. PMMA and PVP films also protected the surface against Al2O3 and ZrO2 growth. Activation of the surface for ALD of ruthenium was achieved by preparing a RuOX layer by microcontact printing. At low temperatures the RuCp2-O2 process nucleated only on this oxidative activation layer but not on bare silicon.