A MODEL TO PREDICT DIAGNOSIS OF PANCREATIC NEUROENDOCRINE TUMORS BASED ON EUS IMAGING FEATURES.

Background: This study aimed to determine predictive clinical and endoscopic ultrasound (EUS) features for pancreatic neuroendocrine tumor (PNET) diagnosis, utilizing EUS-guided tissue acquisition. Methods: A prospective study from 2018-2022 included patients with pancreatic masses undergoing EUS with elastography. Univariate binomial logistic regression followed by multiple logistic regression with significant predictors was employed. A forward selection algorithm identified optimal models based on predictor numbers. Variables encompassed EUS tumor characteristics (e.g., location, size, margins, echogenicity, vascularity on Doppler, main pancreatic duct dilation, elastography appearance, vascular invasion, and hypoechoic rim), alongside demographic and risk factors (smoking, alcohol, diabetes). Results: We evaluated 165 patients (24 PNETs). EUS features significantly linked with PNET diagnosis were well-defined margins (79% vs. 26%, p < 0.001), blue elastography appearance (46% vs. 9.9%, p < 0.001), vascularization (67% vs. 25%, p < 0.001), hypoechoic rim (46% vs. 10%, p < 0.001). The top-performing model, with 89.1% accuracy, included two predictors: a homogeneous lesion (OR, 95% CI) and a hypoechoic rim (OR, 95% CI). Conclusions: EUS appearance can differentiate PNETs from non-PNETs, with the hypoechoic rim being an independent predictor of PNET diagnosis. The most effective predictive model for PNETs combined the homogeneous lesion and presence of the hypoechoic rim.

Analysis of proteins expressed at the time of murine organogenesis.

Two-dimensional electrophoretograms were prepared from wild-type C57BL/6J embryos from day 7.5 through day 9.0 of development. This time period encompasses a critical window of development as the embryo traverses from an egg cylinder through major organogenesis. Consequently, we term this resource MOPED (for mouse organogenesis protein electrophoresis database). By resolving and analyzing the behavior of approximately 1,000 polypeptides per time point, we were able to track many of these polypeptides through this time period in development. Of special note was a burst of induced protein synthesis that was observed in mouse embryos development. Polypeptides observed in mouse embryos that match those identified previously in mouse fibroblasts were noted. Two of them (the intermediate filament-associated protein and tropomyosin-4) were significantly altered in 8.5 day embryos. As more polypeptides are designated, it will be possible to expand the known proteins in the database. MOPED establishes the patterns of synthesis of a large number of polypeptides during a crucial period of development. Thus MOPED is designed to analyze proteins relevant to mouse embryogenesis in the future.

Situs inversus in the developing mouse: proteins affected by the iv mutation (genocopy) and the teratogen retinoic acid (phenocopy).

To decipher genes that are important in the determination of laterality, we compared two-dimensional protein gels from wild-type C57BL/6J mice and C57BL/6J mice that carried the iv mutation, which confers random determination of visceral situs. To span the time period(s) during which laterality determination occurs, we compared computer-analyzed two-dimensional protein gels from wild-type mouse embryos and iv/iv mouse embryos at 7.5, 8.0, and 8.5 days post-coitum. One polypeptide that was expressed only on day 8.0 of development and only in wild-type embryos represents a particular candidate for determination of laterality. Day 8.5 postcoitum represents the earliest time in murine development that laterality is manifest. Two-dimensional gels were compared from 8.5 day embryos that were C57BL/6J wild-type, C57BL/6J iv/iv, or C57BL/6J wild-type and exposed to the teratogen retinoic acid late on day 7. Reproducible alterations of protein synthesis were observed in both the iv genocopy and retinoic acid phenocopy, yielding abnormal laterality determination. The intersection of these peptide changes identifies a protein likely to play a role in the determination of laterality.

Analysis of proteins synthesized by 9.5 day mouse embryos: determination of cardiac and noncardiac proteins.

To catalog polypeptides that were specific to developing hearts, we separated 35S-methionine-labeled 9.5 day mouse embryos into cardiac and noncardiac (carcass) components. Two-dimensional gels were then used to analyze the polypeptides synthesized in these two fractions. As a result, we were able to distinguish polypeptides that were specific to or increased in the heart as well as those polypeptides that were specific to or increased in the embryo minus the dissected heart. Using this analysis, there were two polypeptides that were cardiac-specific and 17 that were expressed at increased levels by at least twofold in the heart. The cardiac-specific polypeptides may be used in further studies to identify early cardiac tissue. Conversely, there were 26 polypeptides unique to noncardiac structures and an additional 15 that were increased in the carcass more than twofold relative to the heart. The noncardiac-specific polypeptides may be used to define contamination of putative cardiac tissue with noncardiac material. Two of the polypeptides expressed more abundantly in the carcass appeared to correspond to known proteins in the mouse fibroblast database, cyclin and tropomyosin 4. Thus the heart at 9.5 days of murine development can be distinguished readily from the remainder of the embryonic mouse both macroscopically and on two-dimensional gels.

Developmental appearance of proteins identified by two-dimensional gel electrophoresis in mouse gonadal tissue.

Gonadal protein patterns of the mouse were studied during fetal development by two-dimensional gel electrophoresis. Fetal mice at days 8.5, 10.5, 12.5, and 14.5 post-coitum were analyzed for male or female specific proteins. Although no sex specific proteins were found, several proteins were found which were expressed in significantly different amounts in the two sexes at about the time of gonadal differentiation. Hence, quantitative differences, rather than qualitative ones, could be related to the initiation of testis or ovary development.