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Zusammenfassung: Keimzelltumoren (KZT) stellen eine heterogene Gruppe von benignen und malignen Tumoren dar. Basierend auf ihren unterschiedlichen biologischen Fähigkeiten und ihrer Herkunft werden KZT in 5 verschiedene Gruppen eingeteilt. Maligne seminomatöse und nichtseminomatöse KZT in beiden Geschlechtern bilden die Gruppe der Typ-II-KZT. Ihre häufigsten Vertreter sind die testikulären malignen KZT. Typ-II-KZT zeigen große Übereinstimmungen mit embryonalen Stammzellen. Die unklassifizierte intratubuläre Keimzellneoplasie (IGCNU), die Vorläuferläsion der KZT Typ II, entwickelt sich aus persistierenden unreifen fetalen Keimzellen, Gonozyten, die sich einem normalen Differenzierungsprozess entziehen. Dabei wird postuliert, dass Exon-17-aktivierende Mutationen der Rezeptortyrosinkinase c-KIT sehr früh während der Keimzellentwicklung auftreten und dass Gonozyten mit aktiviertem c-KIT-Rezeptor in ihrer Differenzierung gehemmt werden und sich dadurch einer normalen Entwicklung entziehen. Neue diagnostische Marker für neoplastische Keimzellen wie OCT3/4 und AP-2γ werden spezifisch in IGCNU, Seminomen und embryonalen Karzinomen detektiert und können helfen, eine Keimzellneoplasie Typ II von anderen malignen Tumoren abzugrenzen.

Dysplasia assessment of Barrett's esophagus biopsies is associated with low observer agreement; guidelines advise expert review. We have developed a web-based review panel for dysplastic Barrett's esophagus biopsies. The purpose of this study was to test if 10 gastrointestinal pathologists working at Dutch Barrett's esophagus expert centres met pre-set benchmark scores for quality criteria. Ten gastrointestinal pathologists twice assessed 60 digitalized Barrett's esophagus cases, enriched for dysplasia; then randomised (7520 assessments). We tested predefined benchmark quality criteria: (a) percentage of ‘indefinite for dysplasia’ diagnoses, benchmark score =14% for all cases, =16% for dysplastic subset, (b) intra-observer agreement; benchmark score =0.66/=0.39, (c) percentage agreement with ‘gold standard diagnosis’; benchmark score =82%/=73%, (d) proportion of cases with high-grade dysplasia underdiagnosed as non-dysplastic Barrett's esophagus; benchmark score =1/78 (=1.28%) assessments for dysplastic subset. Gastrointestinal pathologists had seven years’ Barrett's esophagus-experience, handling seven Barrett's esophagus-cases weekly. Three met stringent benchmark scores; all cases and dysplastic subset, three met extended benchmark scores. Four pathologists lacked one quality criterion to meet benchmark scores. Predefined benchmark scores for expert assessment of Barrett's esophagus dysplasia biopsies are stringent and met by some gastrointestinal pathologists. The majority of assessors however, only showed limited deviation from benchmark scores. We expect further training with group discussions will lead to adherence of all participating gastrointestinal pathologists to quality criteria, and therefore eligible to join the review panel.

Background Dysplasia assessment of Barrett’s esophagus biopsies is associated with low observer agreement; guidelines advise expert review. We have developed a web-based review panel for dysplastic Barrett’s esophagus biopsies.Objective The purpose of this study was to test if 10 gastrointestinal pathologists working at Dutch Barrett’s esophagus expert centres met pre-set benchmark scores for quality criteria.Methods Ten gastrointestinal pathologists twice assessed 60 digitalized Barrett’s esophagus cases, enriched for dysplasia; then randomised (7520 assessments). We tested predefined benchmark quality criteria: (a) percentage of ‘indefinite for dysplasia’ diagnoses, benchmark score ≤14% for all cases, ≤16% for dysplastic subset, (b) intra-observer agreement; benchmark score ≥0.66/≥0.39, (c) percentage agreement with ‘gold standard diagnosis’; benchmark score ≥82%/≥73%, (d) proportion of cases with high-grade dysplasia underdiagnosed as non-dysplastic Barrett’s esophagus; benchmark score ≤1/78 (≤1.28%) assessments for dysplastic subset.Results Gastrointestinal pathologists had seven years’ Barrett’s esophagus-experience, handling seven Barrett’s esophagus-cases weekly. Three met stringent benchmark scores; all cases and dysplastic subset, three met extended benchmark scores. Four pathologists lacked one quality criterion to meet benchmark scores.Conclusion Predefined benchmark scores for expert assessment of Barrett’s esophagus dysplasia biopsies are stringent and met by some gastrointestinal pathologists. The majority of assessors however, only showed limited deviation from benchmark scores. We expect further training with group discussions will lead to adherence of all participating gastrointestinal pathologists to quality criteria, and therefore eligible to join the review panel.

Objectives:Sessile serrated polyps (SSPs) are suggested to be the precursors of 15–30% of all colorectal cancers (CRCs). Therefore, CRC screening modalities should also be designed to detect high-risk SSPs. We compared computed tomography colonography (CTC) with colonoscopy-based screening for the detection of high-risk SSPs in average-risk individuals.Methods:Data from a randomized controlled trial that compared CTC with colonoscopy for population screening were used for the analysis. Individuals diagnosed at CTC with a lesion ≥10 mm in size were referred for colonoscopy. Individuals with only 6–9 mm lesions were offered surveillance CTC. This surveillance CTC was followed by a colonoscopy when a lesion ≥6 mm was detected. Yield of both was accumulated to mimic current American College of Radiology CTC referral strategy (referral of individuals with any lesion ≥6 mm). Per participant detection of ≥1 high-risk (dysplastic and/or ≥10 mm) SSP was compared with colonoscopy using multiple logistic regression analysis.Results:In total, 8,844 individuals were invited to participate (in 2:1 allocation), of which 1,276 colonoscopy and 982 CTC invitees participated in the study. In the colonoscopy arm, 4.3% of individuals were diagnosed with ≥1 high-risk SSP, compared with 0.8% in the CTC arm (odds ratio (OR) 5.5; 95% confidence interval (CI) 2.6–11.6; P<0.001). In total, 3.1% of individuals in the colonoscopy arm were diagnosed with high-risk SSPs as most advanced lesion, compared with 0.4% in the CTC arm (OR 7.7; 95% CI 2.7–21.6; P<0.001). The current CTC strategy showed a marked lower detection for especially flat high-risk SSPs (17 vs. 0), high-risk SSP located in the proximal colon (32 vs. 1), and SSPs with dysplasia (30 vs. 1).Conclusions:In a randomized controlled setting, the detection rate of high-risk SSPs was significantly higher with colonoscopy than CTC. These results might have implications for CTC as a CRC modality for opportunistic screening in average-risk adults.

The B–B bond of bis(trisyl)oxadiborirane OB2R2(R = C(SiMe3)3) is opened by amides R′CO(NHR″) to give the dioxaazadiboracyclohexanes [–BR–O–BR–NR″–CHR′–O–] (R′/R″ = H/H, H/Me, H/Et, Me/H: 5 a–d). The amide MeCO(NHMe) yields 5 e(R′/R″ = Me/Me), when an excess of the amide is applied for 24 h, but yields an isomeric 1 : 1 adduct (6 e), when a stoichiometric amount of the amide is applied for 15 h; upon refluxing this isomer in hexane, it is transformed into 5 e.

We demonstrate the electrical generation of GHz surface acoustic waves (SAWs) on silicon chips using a process entirely compatible with standard CMOS fabrication. In this process, the interdigitated acoustic transducers are embedded in a silicon dioxide layer, which is subsequently coated with a piezoelectric ZnO film. We show that delay lines with sub-um wavelength fabricated using this process reach resonance frequencies approaching 4 GHz.