Presence of gas in left ventricle due to infective endocarditis.

Gas in myocardium is a rare manifestation of infective endocarditis caused by gas producing bacteria. We present a case of infective endocarditis caused by Citrobacter Koseri initially diagnosed by computed tomography and confirmed with transesophageal echocardiogram.

Liver lesions in children and adolescents: cytopathologic analysis and clinical correlates in 44 cases.

The role of fine needle aspiration (FNA) as a first-line diagnostic modality is well-established for neoplastic and nonneoplastic liver masses in adults. However, cytopathologic analysis of such lesions in children and adolescents has not been well studied. An 18-year retrospective review of the cytopathology archives at The Johns Hopkins Hospital identified 44 cases of hepatic FNA in children and adolescents (i.e., 21 years and younger). The cytopathologic material was reviewed and correlated with subsequent surgical pathology diagnoses and/or clinical follow-up. Among the 44 FNAs studied, 40 (90.9%) were deemed diagnostic for evaluation and 4 (9.1%) were nondiagnostic. Twenty four (60%) of the diagnostic FNAs were neoplasms, 10 (25%) were nonneoplastic lesions, and 6 (15%) were "atypical" or "suspicious." There were 21 (87.5%) malignant and 3 (12.5%) benign tumors. Among the malignant cases, metastases/secondary tumors accounted for 12 (54.5%) followed by hepatocellular carcinoma (HCC)--7 (38.1%). The types of metastatic/secondary neoplasms were Wilms tumor (2), germ cell tumor (2), acute leukemias (2), and miscellaneous others (6). Among the nonneoplastic lesions focal nodular hyperplasia was most common--4 (40%). Among the "atypical" cases, 4 (66.6%) turned out to be benign on follow-up, 2 were HCC, and 1 was Hodgkin lymphoma. Immunoperoxidase (IPOX) studies were done in 20 (45.5%) cases to confirm the cytopathologic diagnoses. Overall, FNA showed a sensitivity of 95.2% and a specificity of 100% for a malignant diagnosis.

Continuous requirement of ErbB2 kinase activity for loss of cell polarity and lumen formation in a novel ErbB2/Neu-driven murine cell line model of metastatic breast cancer.

BACKGROUND: Well over a quarter of human breast cancers are ErbB2-driven and constitute a distinct subtype with substantially poorer prognosis. Yet, there are substantial gaps in our understanding of how ErbB2 tyrosine kinase activity unleashes a coordinated program of cellular and extracellular alterations that culminate in aggressive breast cancers. Cellular models that exhibit ErbB2 kinase dependency and can induce metastatic breast cancer in immune competent hosts are likely to help bridge this gap. MATERIALS AND METHODS: Here, we derived and characterized a cell line model obtained from a transgenic ErbB2/Neu-driven mouse mammary adenocarcinoma. RESULTS: The MPPS1 cell line produces metastatic breast cancers when implanted in the mammary fat pads of immune-compromised as well as syngeneic immune-competent hosts. MPPS1 cells maintain high ErbB2 overexpression when propagated in DFCI-1 or related media, and their growth is ErbB2-dependent, as demonstrated by concentration-dependent inhibition of proliferation with the ErbB kinase inhibitor Lapatinib. When grown in 3-dimensional (3-D) culture on Matrigel, MPPS1 cells predominantly form large irregular cystic and solid structures. Remarkably, low concentrations of Lapatinib led to a switch to regular acinar growth on Matrigel. Immunofluorescence staining of control vs. Lapatinib-treated acini for markers of epithelial polarity revealed that inhibition of ErbB2 signaling led to rapid resumption of normal mammary epithelium-like cell polarity. CONCLUSIONS: The strict dependence of the MPPS1 cell system on ErbB2 signals for proliferation and alterations in cell polarity should allow its use to dissect ErbB2 kinase-dependent signaling pathways that promote loss of cell polarity, a key component of the epithelial mesenchymal transition and aggressiveness of ErbB2-driven breast cancers.