Accurate staging of non-metastatic colon cancer with CT: the importance of training and practice for experienced radiologists and analysis of incorrectly staged cases.

PURPOSE: To investigate whether locoregional staging of colon cancer by experienced radiologists can be improved by training and feedback to minimize the risk of over-staging into the context of patient selection for neoadjuvant therapy and to identify potential pitfalls of CT staging by characterizing pathologic traits of tumors that remain challenging for radiologists. METHODS: Forty-five cases of stage I-III colon cancer were included in this retrospective study. Five experienced radiologists evaluated the CTs; 5 baseline scans followed by 4 sequential batches of 10 scans. All radiologists were trained after baseline scoring and 2 radiologists received feedback. The learning curve, diagnostic performance, reader confidence, and reading time were evaluated with pathologic staging as reference. Pathology reports and H&E slides of challenging cases were reviewed to identify potential pitfalls. RESULTS: Diagnostic performance in distinguishing T1-2 vs. T3-4 improved significantly after training and with increasing number of reviewed cases. Inaccurate staging was more frequently related to under-staging rather than over-staging. Risk of over-staging was minimized to 7% in batch 3-4. N-staging remained unreliable with an overall accuracy of 61%. Pathologic review identified two tumor characteristics causing under-staging for T-stage in 5/7 cases: (1) very limited invasive part beyond the muscularis propria and (2) mucinous composition of the invading part. CONCLUSION: The high accuracy and specificity of T-staging reached in our study indicate that sufficient training and practice of experienced radiologists can ensure high validity for CT staging in colon cancer to safely use neoadjuvant therapy without significant risk of over-treatment, while N-staging remained unreliable.

Predicting local tumour progression after ablation for colorectal liver metastases: CT-based radiomics of the ablation zone.

PURPOSE: To assess whether CT-based radiomics of the ablation zone (AZ) can predict local tumour progression (LTP) after thermal ablation for colorectal liver metastases (CRLM). MATERIALS AND METHODS: Eighty-two patients with 127 CRLM were included. Radiomics features (with different filters) were extracted from the AZ and a 10 mm periablational rim (PAR)on portal-venous-phase CT up to 8 weeks after ablation. Multivariable stepwise Cox regression analyses were used to predict LTP based on clinical and radiomics features. Performance (concordance [c]-statistics) of the different models was compared and performance in an 'independent' dataset was approximated with bootstrapped leave-one-out-cross-validation (LOOCV). RESULTS: Thirty-three lesions (26 %) developed LTP. Median follow-up was 21 months (range 6-115). The combined model, a combination of clinical and radiomics features, included chemotherapy (HR 0.50, p = 0.024), cT-stage (HR 10.13, p = 0.016), lesion size (HR 1.11, p = <0.001), AZ_Skewness (HR 1.58, p = 0.016), AZ_Uniformity (HR 0.45, p = 0.002), PAR_Mean (HR 0.52, p = 0.008), PAR_Skewness (HR 1.67, p = 0.019) and PAR_Uniformity (HR 3.35, p < 0.001) as relevant predictors for LTP. The predictive performance of the combined model (after LOOCV) yielded a c-statistic of 0.78 (95 %CI 0.65-0.87), compared to the clinical or radiomics models only (c-statistic 0.74 (95 %CI 0.58-0.84) and 0.65 (95 %CI 0.52-0.83), respectively). CONCLUSION: Combining radiomics features with clinical features yielded a better performing prediction of LTP than radiomics only. CT-based radiomics of the AZ and PAR may have potential to aid in the prediction of LTP during follow-up in patients with CRLM.

The characterization of the soybean polygalacturonase-inhibiting proteins (Pgip) gene family reveals that a single member is responsible for the activity detected in soybean tissues.

Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) proteins that inhibit fungal endopolygalacturonases (PGs). They are encoded by multigene families whose members show functional redundancy and subfunctionalization for recognition of fungal PGs. In order to expand the information on the structure and functional features of legume PGIP, we have isolated and characterized four members of the soybean Pgip gene family and determined the properties of the encoded protein products. Sequence analysis showed that these genes form two clusters: one cluster of about 5 kbp containing Gmpgip1 and Gmpgip2, and the other containing Gmpgip3 and Gmpgip4 within a 60 kb fragment of a separate BAC clone. Sequence diversification of the four members resides mainly in the xxLxLxx region that includes residues forming the beta-sheet B1. When compared with other legume Pgip genes, Gmpgip3 groups with the bean genes Pvpgip1 and Pvpgip2, suggesting that these genes are closer to the ancestral gene. At the protein level, only GmPGIP3 shows the capability to inhibit fungal PGs. The spectrum of inhibition of GmPGIP3 against eight different fungal PGs mirrors that of the PGIP purified from soybean tissues and is similar to that of the bean PvPGIP2, one of the most efficient inhibitors so far characterized. We also report that the four Gmpgip genes are differentially regulated after wounding or during infection with the fungal pathogen Sclerotinia sclerotiorum. Following fungal infection Gmpgip3 is up regulated promptly, while Gmpgip2 is delayed.

Interactions of ganglioside GM1 with human and fetal calf sera. Formation of ganglioside-serum albumin complexes.

The interactions of ganglioside GM1 with human and fetal calf sera were studied, the following main results being obtained: (a) GM1, upon incubation with both sera gave origin to two GM1-protein complexes, which also occurred after interaction of GM1 with the albumin fractions prepared from the same sera. Instead no complex formation occurred using the albumin-free fractions. Therefore GM1 appeared to specifically bind serum albumin and to form GM1-albumin complexes. (b) GM1 binding to serum albumin started at ganglioside concentrations surely micellar (above 10(-6) M), was time and concentration dependent, and resulted in a relevant degree of GM1 complexation (up to 80% of total GM1 in human serum and up to 18% in fetal calf serum). (c) the binding kinetics appeared, in both serum and the correspondent albumin fraction, to be biphasic: in the first phase, occurring till about 2 . 10(-4) M GM1, the ratio between bound and total GM1 increased linearly with increasing GM1 concentration; in the second phase, occurring above 2 . 10(-4) M, the ratio remained practically constant. After these findings it should be expected that GM1, when present in serum containing systems, forms complexes with albumin. This should be approximately considered when studying the effects of exogeneous GM1 in in vivo and in vitro (tissue cultures) systems.

Quantitative evaluation of two pathways for ethanolamine phosphoglyceride biosynthesis in rat brain in vivo.

[3H]Ethanolamine and [32P]orthophosphate were injected intraventricularly into adult female rats. At varying time intervals after the injection (1--10 min), the animals were killed by means of a microwave apparatus, and phosphorylethanolamine and ethanolamine phosphoglycerides were extracted from the brains and counted after separation. The kinetic constants for phosphorylethanolamine incorporation into ethanolamine lipids were calculated both from 3H data and from 32P data. From our results, it seems that base exchange reactions for ethanolamine incorporation into ethanolamine lipids are a pathway active in brain in vivo.