A protein complex network of Drosophila melanogaster.

Determining the composition of protein complexes is an essential step toward understanding the cell as an integrated system. Using coaffinity purification coupled to mass spectrometry analysis, we examined protein associations involving nearly 5,000 individual, FLAG-HA epitope-tagged Drosophila proteins. Stringent analysis of these data, based on a statistical framework designed to define individual protein-protein interactions, led to the generation of a Drosophila protein interaction map (DPiM) encompassing 556 protein complexes. The high quality of the DPiM and its usefulness as a paradigm for metazoan proteomes are apparent from the recovery of many known complexes, significant enrichment for shared functional attributes, and validation in human cells. The DPiM defines potential novel members for several important protein complexes and assigns functional links to 586 protein-coding genes lacking previous experimental annotation. The DPiM represents, to our knowledge, the largest metazoan protein complex map and provides a valuable resource for analysis of protein complex evolution.

Loss of expression of MLH1 in non-dysplastic crypts is a harbinger of neoplastic progression in sessile serrated adenomas/polyps.

AIMS: Dysplasia in colonic sessile serrated adenomas (SSAs)/sessile serrated polyps often shows loss of MLH1 expression as determined with immunohistochemistry, but the significance of loss of MLH1 expression in non-dysplastic crypts in these polyps is less well studied. The purpose of this study was to evaluate the prevalence of loss of MLH1 expression in non-dysplastic crypts in SSAs, and to evaluate its significance with regard to progression of these polyps. METHODS AND RESULTS: Four hundred SSAs, including 158 SSAs without dysplasia, 219 SSAs with dysplasia (SSAD), and 23 SSAs with invasive adenocarcinoma (SSAC), were evaluated immunohistochemically for loss of MLH1 expression in both non-dysplastic and dysplastic portions of the polyps. Seventy-one of 400 (18%) SSAs showed loss of MLH1 expression in non-dysplastic crypts. The prevalence of MLH1-deficient non-dysplastic crypts was higher in polyps with dysplasia or carcinoma (7%, 22%, and 52% in SSAs, SSADs, and SSACs, respectively; P < 0.0001). When SSAs with MLH1-deficient dysplasia and those with MLH-1-proficient dysplasia were compared, those with MLH1-deficient dysplasia were more likely to have MLH1-deficient non-dysplastic crypts (66% versus 8.1%, P < 0.0001) and a greater number of discrete foci (3.6 foci versus 1.1 foci, P = 0.008). Also, non-dysplastic crypts with loss of MLH1 expression were more likely to be contiguous with the dysplasia when the dysplasia also showed loss of MLH1 expression (26% versus 0%, P = 0.02). CONCLUSIONS: Our results suggest that loss of MLH1 expression in non-dysplastic crypts in SSAs precedes the development of MLH1-deficient dysplasia and adenocarcinoma, and may be a biomarker of an advanced serrated polyp even in the absence of dysplasia.

Clinicopathologic and outcome study of sessile serrated adenomas/polyps with serrated versus intestinal dysplasia.

It is believed that sessile serrated adenomas/polyps lead to the development of microsatellite unstable cancer via a dysplasia-carcinoma sequence. Little is known regarding the morphologic and biologic features, and outcome of sessile serrated adenomas/polyps with dysplasia, or of its specific dysplasia subtypes (intestinal versus serrated). The aims of this study were to analyze and compare the clinical, pathologic, and outcome characteristics of sessile serrated adenomas/polyps with serrated versus intestinal dysplasia. The study included 86 patients with sessile serrated adenomas/polyps with dysplasia (50 serrated dysplasia, 22 intestinal dysplasia, 14 mixed serrated and intestinal dysplasia). The clinical and pathologic features, and the prevalence rate of prior, concurrent, and future neoplastic lesions, were compared between sessile serrated adenomas/polyps with intestinal versus serrated dysplasia and with matched control patients with ≥1 conventional adenoma. The mean age of the patients, polyp size, and prevalence of adenocarcinoma within the polyps were significantly higher in sessile serrated adenomas/polyps with high versus low-grade dysplasia. Sessile serrated adenomas/polyps with intestinal dysplasia showed a significantly higher rate of adenocarcinoma (23%) compared with those with serrated dysplasia (6%, P=0.05), and the high-grade lesions occurred at a significantly younger age in the former compared with the latter (65 versus 76 years, P=0.05). Compared with patients with conventional adenomas, patients with sessile serrated adenomas/polyps with dysplasia showed a significantly higher rate of invasive carcinoma within the polyps (12 versus 0%, P=0.01) and a significantly lower association with prior or future conventional adenomas. Sessile serrated adenomas/polyps with dysplasia should be considered high-risk neoplastic precursor lesions, particularly those with intestinal dysplasia. Cancer may develop from sessile serrated adenomas/polyps with either type of dysplasia.

Amebic appendicitis: a case report.

Changing the paradigm of treatment of acute appendicitis to non-operative management can miss unusual etiologies that can only be diagnosed on pathologic analysis. Presented is a case of amebic appendicitis in which antibiotic management was dictated by post-operative pathology findings.

Evidence for continuity of interstitial spaces across tissue and organ boundaries in humans.

Bodies have continuous reticular networks, comprising collagens, elastin, glycosaminoglycans, and other extracellular matrix components, through all tissues and organs. Fibrous coverings of nerves and blood vessels create structural continuity beyond organ boundaries. We recently validated fluid flow through human fibrous tissues, though whether these interstitial spaces are continuous through the body or discontinuous, confined within individual organs, remains unclear. Here we show evidence for continuity of interstitial spaces using two approaches. Non-biological particles (tattoo pigment, colloidal silver) were tracked within colon and skin interstitial spaces and into adjacent fascia. Hyaluronic acid, a macromolecular component of interstitial spaces, was also visualized. Both techniques demonstrate interstitial continuity within and between organs including within perineurium and vascular adventitia traversing organs and the spaces between them. We suggest that there is a body-wide network of fluid-filled interstitial spaces that has significant implications for molecular signaling, cell trafficking, and the spread of malignant and infectious disease.

Intragastric Balloons: An Emerging Therapy for Nonalcoholic Steatohepatitis and Fibrosis?

Weight loss through lifestyle intervention remains the mainstay treatment for nonalcoholic steatohepatitis (NASH). Nevertheless, only a minority of patients undergoing lifestyle intervention are able to achieve the weight loss threshold that reverses NASH histologic features. This case report demonstrates a minimally invasive method of treating NASH using an intragastric balloon. With endoscopic ultrasound-guided liver biopsy at the time of intragastric balloon removal, we demonstrate a significant improvement in NASH histologic features including steatosis, ballooning, lobular inflammation, and fibrosis. This endoscopic method may offer an alternative solution to patients with NASH who fail lifestyle intervention.

Detection of ERBB2 Amplification by Next-Generation Sequencing Predicts HER2 Expression in Colorectal Carcinoma.

OBJECTIVES: ERBB2 (human epidermal growth factor receptor 2 [HER2]) amplification/overexpression in colorectal carcinomas (CRCs) may predict response to HER2 inhibitors. We correlated ERBB2 amplification by next-generation sequencing (NGS) with HER2 overexpression by immunohistochemistry. METHODS: NGS was performed on specimens containing 20% or more tumor. HER2 immunohistochemistry (clone SP3) was scored semiquantitatively by H-score. ERBB2 fluorescence in situ hybridization (FISH) was performed to examine copy alterations in one HER2-heterogeneous tumor. RESULTS: ERBB2 amplification was detected in 2% of 1,300 CRCs analyzed by NGS. HER2 immunohistochemistry was examined in 15 cases with ERBB2 amplification (six or more copies), 10 with low gain (three to five copies), and 77 copy neutral. ERBB2 amplification and HER2 immunohistochemistry showed perfect concordance at an H-score of 105 or more. FISH confirmed homogeneous ERBB2 amplification in a tumor showing HER2 protein expression heterogeneity. ERBB2 amplification anticorrelated with RAS/RAF mutations (P = .0001). No ERBB2-amplified cases showed mismatch repair deficiency. CONCLUSIONS: NGS-detected ERBB2 amplification highly correlates with HER2 overexpression in CRC, but immunohistochemistry is required to capture protein-level heterogeneity.