3,003 research outputs found
Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations
Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment. \ud
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Reliability of perceptions of voice quality: evidence from a problem asthma clinic population
<p>Introduction: Methods of perceptual voice evaluation have yet to achieve satisfactory consistency; complete acceptance of a recognised clinical protocol is still some way off.</p>
<p>Materials and methods: Three speech and language therapists rated the voices of 43 patients attending the problem asthma clinic of a teaching hospital, according to the grade-roughness-breathiness-asthenicity-strain (GRBAS) scale and other perceptual categories.</p>
<p>Results and analysis: Use of the GRBAS scale achieved only a 64.7 per cent inter-rater reliability and a 69.6 per cent intra-rater reliability for the grade component. One rater achieved a higher degree of consistency. Improved concordance on the GRBAS scale was observed for subjects with laryngeal abnormalities. Raters failed to reach any useful level of agreement in the other categories employed, except for perceived gender.</p>
<p>Discussion: These results should sound a note of caution regarding routine adoption of the GRBAS scale for characterising voice quality for clinical purposes. The importance of training and the use of perceptual anchors for reliable perceptual rating need to be further investigated.</p>
Laryngeal preneoplastic lesions and cancer: challenging diagnosis. Qualitative literature review and meta-analysis
Background: The treatment of laryngeal cancer and its precursor lesions has a great impact on important laryngeal basic functions, thus, early detection and preoperative assessment are important for a curative and function-preserving therapy. Furthermore, delayed diagnosis, leads to loco-regional failure and a high incidence of second primary tumor, reasons for poor outcome. In this setting, there are two basic clinical problems in the management of premalignant and malignant laryngeal lesions. First, small and thin lesions are difficult to evaluate by the histopathologic examination and initial biopsies are often not sufficient for a conclusive diagnosis. Second, margins of the specimens from surgical excisions are difficult to evaluate due to tissue damage from the device, leaving us in doubt whether the excision is radical or not.
From these observations, it is obvious that an instrument offering the possibility to detect pre-cancerous-early cancerous lesions, and satellite foci or second primaries would be the key to improving the survival rate in head and neck cancer. But, despite the high number of more advanced diagnostic techniques and methods, unfortunately, it is not uncommon for different clinicians to use different nomenclature or to identify different stage for the same laryngeal lesion.
Object. Different modalities of diagnostic techniques of laryngeal lesions exist. Rather than difference between benign and obvious malignant diseases, more difficult is to detect the presence of precancerous epithelial alterations. Not all tests achieve the same diagnostic accuracy and that all tests must be considered against a gold standard, hence this meta-analysis of literature aimed to synthesise the validity of each single diagnostic technique in identifying and staging laryngeal diseases.
Methods: A systematic review of literature was led searching for articles mentioning the following terms including their various combinations to maximize the yield: larynx, laryngeal cancer, white light (WL) endoscopy, contact endoscopy (CE), stroboscopy, autofluorescence (AF), ultrasound (US), narrow band imaging (NBI), computers assail tomography (CAT), magnetic resonance imaging (MRI), positron emission tomography (PET). A quantitative analysis was carried on for paper published after 2005 onward, reporting a minumun series of 10 patients each study, declaring sensitivity and specificity of each diagnostic system.
Results: The search identified 7215 publications, of which 3616 published after 2005, with a final results of a total of 214 articles stratified and included by our selection criteria. 58 out of 214 articles were selected for quantitative synthesis. 35 out of 58 studies had a quality score of â„ 6 (good), 15 presented a score between 4 and 5 (fair), the remaining 8 had a score between 2 and 3 (poor). While objections can be raised about the pooling of different diagnostic procedures under the same group and the high level of heterogeneity in the meta-analyses, the inclusion of over 2500 patients makes the results fairly robust.
Conclusions: A comprehensive overview of the most recent advances in laryngeal imaging technology combined with all of the information needed to interpret findings and successfully manage patients with voice disorders can be found herein. With these data, clinicians can risk-stratify patients and select proper examination modalities in order to provide appropriate care. Moreover, study limitations, together with possible clinical and research implications have been counted, as well
A study of activation antigens involved in the pathological mechanisms and pathways of cutaneous malignant disease with particular emphasis on cutaneous T cell lymphoma and malignant melanoma
The investigation of dermatological conditions embraces the concept of a clinicopathological correlation. The studies into cutaneous T cell lymphoma (CTCL) and
malignant melanoma (MM), presented here involved predominantly
immunocytochemical procedures and relate to the investigations into AP-1
protein expression in CTCL and melanocyte activation antigens in MM.
Results: Findings indicate that expression of AP-1 proteins differs not only
according to type of CTCL but also according to stages of tumour progression. In MM activation antigen expression varies with tumour metastasis.
Consideration of the role of techniques in terms of sensitivity and specificity form a pivitol component in the evaluation of tumour antigen expression
Evaluation of Elastographic techniques generated by means of external vibration
Breast cancer is one of the greatest problems of national and international public health, whose incidence
among women population shows an increasing trend. Nowadays there are several elastographic
techniques, which seek to characterize the tissue, that is, to analyze the response produced by the application
of a perturbation in the medium, to describe its mechanical properties. Among the modalities
used are ultrasound, nuclear magnetic resonance and optical coherence tomography. On the other hand,
among the types of disturbance used are low frequency mechanical waves, a uniform compression force
or acoustic radiation force.
In this thesis work, ultrasound was used due to its low economical cost in comparison to the other
modalities. In addition, the type of perturbation selected was the external mechanical vibration, as it
ensures the achievement of quantitative results, there is no risk of temperature rise in the analyzed area
and allows the repeatability of the results obtained. Hence, two elastographic techniques were the axes
of the present work: vibro-elastography and normal vibration holography. For the first, a calibrated
phantom and a gelatin-based phantom were used, in order to characterize and validate the technique
over a wide range of excitation frequencies. Posteriorly, 18 patients were analyzed prior biopsy exam,
obtaining elastograms and contrasting them with the respective biopsy results. The results suggest that
the technique is able to identify the presence of benign or malignant cancer, and the elasticity estimated
agree with values reported in the literature. The second technique is proposed in the elastography field
for the first time. Based on holography, its experimental scheme is established, and the mathematical
expression for shear speed estimation is presented. Results from simulation and experiments performed
on homogeneous and heterogeneous phantoms are presented, and the estimates are compared with
previously obtained reference values. The results suggest that the estimates are close to the reference
values for all media tested, and the technique must be studied in depth to revert artifacts formation.Tesi
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Patterns of injury and violence in Yaoundé Cameroon: an analysis of hospital data.
BackgroundInjuries are quickly becoming a leading cause of death globally, disproportionately affecting sub-Saharan Africa, where reports on the epidemiology of injuries are extremely limited. Reports on the patterns and frequency of injuries are available from Cameroon are also scarce. This study explores the patterns of trauma seen at the emergency ward of the busiest trauma center in Cameroon's capital city.Materials and methodsAdministrative records from January 1, 2007, through December 31, 2007, were retrospectively reviewed; information on age, gender, mechanism of injury, and outcome was abstracted for all trauma patients presenting to the emergency ward. Univariate analysis was performed to assess patterns of injuries in terms of mechanism, date, age, and gender. Bivariate analysis was used to explore potential relationships between demographic variables and mechanism of injury.ResultsA total of 6,234 injured people were seen at the Central Hospital of Yaoundé's emergency ward during the year 2007. Males comprised 71% of those injured, and the mean age of injured patients was 29 years (SD = 14.9). Nearly 60% of the injuries were due to road traffic accidents, 46% of which involved a pedestrian. Intentional injuries were the second most common mechanism of injury (22.5%), 55% of which involved unarmed assault. Patients injured in falls were more likely to be admitted to the hospital (p < 0.001), whereas patients suffering intentional injuries and bites were less likely to be hospitalized (p < 0.001). Males were significantly more likely to be admitted than females (p < 0.001)DiscussionPatterns in terms of age, gender, and mechanism of injury are similar to reports from other countries from the same geographic region, but the magnitude of cases reported is high for a single institution in an African city the size of Yaoundé. As the burden of disease is predicted to increase dramatically in sub-Saharan Africa, immediate efforts in prevention and treatment in Cameroon are strongly warranted
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