Acute heart failure caused by a giant hepatocellular metastatic tumor of the right atrium

We present a symptomatic 40-year-old cirrhotic man who presented with sudden onsets of syncope. Echocardiography revealed right ventricular outflow track obstruction caused by a huge right atrial mass. The tumor was surgically excised under cardiopulmonary bypass. Although no primary cancerous lesion in the liver was detected, histopathology revealed that the mass was a metastatic hepatocellular carcinoma. The aim of this report is to show the value of urgent preoperative computed tomography and its contribution in the operative strategy. The importance of urgent surgical treatment with tricuspid valve sparing tumor resection is emphasized even though the prognosis for such patients is dismal. We also discuss the further management options of such rare case

Prognostic impact of reduced connexin43 expression and gap junction coupling of neoplastic stromal cells in giant cell tumor of bone

Missense mutations of the GJA1 gene encoding the gap junction channel protein connexin43 (Cx43) cause bone malformations resulting in oculodentodigital dysplasia (ODDD), while GJA1 null and ODDD mutant mice develop osteopenia. In this study we investigated Cx43 expression and channel functions in giant cell tumor of bone (GCTB), a locally aggressive osteolytic lesion with uncertain progression. Cx43 protein levels assessed by immunohistochemistry were correlated with GCTB cell types, clinico-radiological stages and progression free survival in tissue microarrays of 89 primary and 34 recurrent GCTB cases. Cx43 expression, phosphorylation, subcellular distribution and gap junction coupling was also investigated and compared between cultured neoplastic GCTB stromal cells and bone marow stromal cells or HDFa fibroblasts as a control. In GCTB tissues, most Cx43 was produced by CD163 negative neoplastic stromal cells and less by CD163 positive reactive monocytes/macrophages or by giant cells. Significantly less Cx43 was detected in alpha-smooth muscle actin positive than alpha-smooth muscle actin negative stromal cells and in osteoclast-rich tumor nests than in the adjacent reactive stroma. Progressively reduced Cx43 production in GCTB was significantly linked to advanced clinico-radiological stages and worse progression free survival. In neoplastic GCTB stromal cell cultures most Cx43 protein was localized in the paranuclear-Golgi region, while it was concentrated in the cell membranes both in bone marrow stromal cells and HDFa fibroblasts. In Western blots, alkaline phosphatase sensitive bands, linked to serine residues (Ser369, Ser372 or Ser373) detected in control cells, were missing in GCTB stromal cells. Defective cell membrane localization of Cx43 channels was in line with the significantly reduced transfer of the 622 Da fluorescing calcein dye between GCTB stromal cells. Our results show that significant downregulation of Cx43 expression and gap junction coupling in neoplastic stromal cells are associated with the clinical progression and worse prognosis in GCTB

Clinical importance of aspirin and clopidogrel resistance

Aspirin and clopidogrel are important components of medical therapy for patients with acute coronary syndromes, for those who received coronary artery stents and in the secondary prevention of ischaemic stroke. Despite their use, a significant number of patients experience recurrent adverse ischaemic events. Interindividual variability of platelet aggregation in response to these antiplatelet agents may be an explanation for some of these recurrent events, and small trials have linked “aspirin and/or clopidogrel resistance”, as measured by platelet function tests, to adverse events. We systematically reviewed all available evidence on the prevalence of aspirin/clopidogrel resistance, their possible risk factors and their association with clinical outcomes. We also identified articles showing possible treatments. After analyzing the data on different laboratory methods, we found that aspirin/clopidogrel resistance seems to be associated with poor clinical outcomes and there is currently no standardized or widely accepted definition of clopidogrel resistance. Therefore, we conclude that specific treatment recommendations are not established for patients who exhibit high platelet reactivity during aspirin/clopidogrel therapy or who have poor platelet inhibition by clopidogrel

Examples of numerical chromosomal and telomeric alterations in GCTB stromal cells of male patients.

<p>Centromeric 3 (red), 4 (green), 6 (yellow) and X (light blue) signals show different levels of polysomy. Chromosome 4 trisomy in a cell disomic for the rest (3,6 and X) of the tested centrosomes (b) and chromosome 11 subtelomeric loss and tetrasomy in a cell of another case (c). Scale bar on <u>a</u> represents 5 μm; and 2.5 μm on <u>b</u> and <u>c</u>.</p

Kaplan-Meier plots of univariate Cox regression analysis of Cx43 immunoscores in giant cell tumor of bone.

<p>An increased hazard of progression (reduced PFS) is linked to scores 1–3 vs 4–8 (arrow) separating patient number around the median, N_score1-3 = 60 (48.8%), N_score4-8 = 63 (51.2%) (a). Log-rank test proves significantly reduced progression free survival (PFS) in tumors presenting low (scores 1–3) vs high (scores 4–8) Cx43 protein levels (b).</p

Dye coupling test for measuring potential communication through gap junctions with flow cytometry.

<p>Scheme on the principle of the technique (a). Unlabelled cell are mixed with double dye labelled cells (orange) of the same kind at a ratio of 10:1 (a-b). Calcein (Mw:622 Da, green), after esterase cleavage becomes hydrophylic and can pass into adjacent cells through gap junctions, while the larger lypophylic DiI (red) is trapped within donor cell membranes (b). The proportion of single calcein labelled cells measured with flow cytometry (B+-, lower right box) indicating dye coupling, is significantly higher (p<0.001) in the control cell cultures (c) than in GCTB stromal cell cultures (d). Diagram showing the mean ± standard deviation of dye transfer in 3 independent experiments using stromal cells isolated from 3 patients (e). Scale bar on <u>b</u> represents 20 μm.</p

Immunoperoxidase (a-c) and immunofluorescence (d-e) detection in osteoclast rich areas and surrounding stroma (f and g), and clinicopathological correlations of Cx43 protein levels (h and i) in giant cell tumor of bone.

<p>Examples of tumors with moderate (a; score 3) and high (b; score 8) Cx43 levels in mononuclear cells. Strong Cx43 reaction in the preexisting osteoblast layer around bone spicules and in osteocytes (arrowhead) (c). A tumor nest and adjacent ring of reactive stroma are annotated separately for counting Cx43 (Alexa564, red) plaques (d; OC-osteoclasts). Higher power of (d) with osteoclasts encircled (e). Digital image segmentation highlights Cx43 plaques in orange for automated counting (f). Both the Cx43 positive area fraction (g) and the number of Cx43 positive plaques (h) are significantly reduced within tumor nests (p<0.01). Cx43 levels are also significantly reduced in aggressive vs active and in aggressive vs latent clinicoradiological tumor stages (i). Scale bar on (a) represents 30 μm on <u>a</u>, <u>b</u> and <u>c</u>; 80 μm on <u>d</u>, 30 μm on <u>e</u> and 15 μm on <u>f</u>.</p

Immunofluorescence detection of Cx43 (red; a-e) along with CD163 (green; a-c) or α-smooth muscle actin (α-SMA, green; d) for defining Cx43 positive cell fractions (f and g) in giant cell tumor of bone.

<p>Cx43 positive mononuclear cells rarely co-localize with the monocyte/marcophage marker CD163 (a). Automated image segmentation (HistoQuant) highlights Cx43 in orange and CD163 in greeen in separate layers (b) and a 3^rd layer is used to count red Cx43 signals in green cells (arrowheads) (c). Cx43 signals (see double and single labeled insets) are more frequent in α-SMA deficient (upper panel), than in strongly α-SMA positive cells (d; lower panel, non-specific signals in red blood cells are encircled). Cx43 plaques are linked to mononuclear cells-some are partly engulfed by an osteoclasts (arrow)- and not directly to giant cells (e). Diagrams showing significant differences in Cx43 positive mononuclear cell fractions counted using HistoQuant image analysis (f and g). Cell nuclei are stained blue using Hoescht. Scale bar on <u>a</u> represents 30 μm on <u>a</u>, <u>b</u> and <u>d</u>; and 15 μm on <u>c</u> and <u>e</u>.</p