Early detection in head and neck cancer - current state and future perspectives

Survival and quality of life in head and neck cancer are directly linked to the size of the primary tumor at first detection. In order to achieve substantial gain at these issues, both, primary prevention and secondary prevention, which is early detection of malignant lesions at a small size, have to be improved. So far, there is not only a lack in the necessary infrastructure not only in Germany, but rather worldwide, but additionally the techniques developed so far for early detection have a significance and specificity too low as to warrant safe implementation for screening programs. However, the advancements recently achieved in endoscopy and in quantitative analysis of hypocellular specimens open new perspectives for secondary prevention. Chromoendoscopy and narrow band imaging (NBI) pinpoint suspicious lesions more easily, confocal endomicroscopy and optical coherence tomography obtain optical sections through those lesions, and hyperspectral imaging classifies lesions according to characteristic spectral signatures. These techniques therefore obtain optical biopsies. Once a "bloody" biopsy has been taken, the plethora of parameters that can be quantified objectively has been increased and could be the basis for an objective and quantitative classification of epithelial lesions (multiparametric cytometry, quantitative histology). Finally, cytomics and proteomics approaches, and lab-on-the-chip technology might help to identify patients at high-risk. Sensitivity and specificity of these approaches have to be validated, yet, and some techniques have to be adapted for the specific conditions for early detection of head and neck cancer. On this background it has to be stated that it is still a long way to go until a population based screening for head and neck cancer is available. The recent results of screening for cancer of the prostate and breast highlight the difficulties implemented in such a task

Krebsfrüherkennung unter Nutzung des hyperspektralen Imagings - Evaluation nach Fehlerkorrektur in Bilderstellung und Auswertung

Hintergrund: Krebsfrüherkennung stellt einen immensen Faktor in der Prognose von Krebserkrankungen dar. Bei rein visueller Inspektion wird auch bei gut einsehbaren Schleimhäuten (Mundhöhle, Oropharynx) die Verdachtsdiagnose oft zu spät bei dann bereits fortgeschrittenem Stadium gestellt. Hyperspektrales Imaging könnte entscheidend zur nicht invasiven Krebsfrüherkennung unter Nutzung üblicher Endoskope beitragen.Material und Methoden: Bei 85 Pat. wurde im Rahmen einer geplanten Endoskopie ein hyperspektrales Imaging mittels eines starren 0°-Endoskops, eines Monochromators und einer Hyperspektralkamera in der Mundhöhle bzw. im Oropharynx durchgeführt. Klinisch suspekt imponierende Läsionen sowie gesunde Schleimhautareale wurden händisch in den erstellten Bildstapeln markiert und mittels einer speziellen Software einer Klassifikation unterzogen. Die Ergebnisse wurden ohne Übertragung (innerhalb desselben Pat.) sowie mit Übertragung (auf einen anderen Pat.) miteinander korreliert.Ergebnisse: Es zeigten sich mehrere Fehlerquellen, wie z.B. Bewegungsartefakte, Spiegelungen und Fehler in der Datenspeicherung, die eine Auswertung der Bildstapel erschwerten. Unter Weiterentwicklung der Software konnten diese Fehler größtenteils behoben werden. Die Korrelation der Klassifikation ergab ohne Übertragung eine Sensitivität von 88-100% sowie eine Spezifität von 81-100%, mit Übertragung eine Sensitivität von 47-96% sowie eine Spezifität von 87-99%.Schlussfolgerung: Diese Studie konnte erneut zeigen, dass hyperspektrales Imaging ein hohes Potential hat, unter Nutzung üblicher Endoskope zur nicht invasiven Krebsfrüherkennung beizutragen. Weitere Studien zur Validierung sowie die Fortentwicklung der Software zur suffizienten automatisierten Fehlerkorrektur sind allerdings notwendig.Unterstützt durch: Deutsche KrebshilfeDer Erstautor gibt keinen Interessenkonflikt an

Laser scanning cytometry: understanding the immune system in situ

Flow cytometry allows quantitative analysis of the identity and effector function of individual cells. However, it cannot provide information on cellular responses that occur within physiological tissue microenvironments. Laser scanning cytometry is an emerging technology that allows imaging and quantitative analysis of individual cells in tissues in situ. This article describes the technology and its potential for delineating the molecular and cellular events underpinning the immune response in health and disease

Some southern African plant species used to treat helminth infections in ethnoveterinary medicine have excellent antifungal activities

<p>Abstract</p> <p>Background</p> <p>Diseases caused by microorganisms and parasites remain a major challenge globally and particularly in sub-Saharan Africa to man and livestock. Resistance to available antimicrobials and the high cost or unavailability of antimicrobials complicates matters. Many rural people use plants to treat these infections. Because some anthelmintics e.g. benzimidazoles also have good antifungal activity we examined the antifungal activity of extracts of 13 plant species used in southern Africa to treat gastrointestinal helminth infections in livestock and in man.</p> <p>Methods</p> <p>Antifungal activity of acetone leaf extracts was determined by serial microdilution with tetrazolium violet as growth indicator against <it>Aspergillus fumigatus, Cryptococcus neoformans</it> and <it>Candida albicans</it>. These pathogens play an important role in opportunistic infections of immune compromised patients. Cytotoxicity was determined by MTT cellular assay. Therapeutic indices were calculated and selectivity for different pathogens determined. We proposed a method to calculate the relation between microbicidal and microbistatic activities. Total activities for different plant species were calculated.</p> <p>Results</p> <p>On the whole, all 13 extracts had good antifungal activities with MIC values as low as 0.02 mg/mL for extracts of <it>Clausena anisata</it> against <it>Aspergillus fumigatus a</it>nd 0.04 mg/mL for extracts of <it>Zanthoxylum capense, Clerodendrum glabrum,</it> and <it>Milletia grandis</it>, against <it>A. fumigatus. Clausena anisata</it> extracts had the lowest cytotoxicity (LC₅₀) of 0.17 mg/mL, a reasonable therapeutic index (2.65) against <it>A. fumigatus</it>. It also had selective activity against <it>A. fumigatus</it>, an overall fungicidal activity of 98% and a total activity of 3395 mL/g against <it>A. fumigatus</it>. This means that 1 g of acetone leaf extract can be diluted to 3.4 litres and it would still inhibit the growth. <it>Clerodendrum glabrum, Zanthoxylum capense</it> and <it>Milletia grandis</it> extracts also yielded promising results.</p> <p>Conclusions</p> <p>Some plant extracts used for treatment of parasitic infections also have good antifungal activity. Because it is much easier to isolate antifungal compounds by bioassay guided fractionation, this approach may facilitate the isolation of anthelmintic compounds from active plant extracts. The viability of this approach can be tested by isolating the antifungal compounds and then determining its anthelmintic activity. Some of these plant extracts may also be useful in combating fungal infections.</p

Listening to learners working with ROBOTS

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