CXCR4 Cardiac Specific Knockout Mice Develop a Progressive Cardiomyopathy.

Activation of multiple pathways is associated with cardiac hypertrophy and heart failure. We previously published that CXCR4 negatively regulates ß-adrenergic receptor (ß-AR) signaling and ultimately limits ß-adrenergic diastolic (Ca2+) accumulation in cardiac myocytes. In isolated adult rat cardiac myocytes; CXCL12 treatment prevented isoproterenol-induced hypertrophy and interrupted the calcineurin/NFAT pathway. Moreover; cardiac specific CXCR4 knockout mice show significant hypertrophy and develop cardiac dysfunction in response to chronic catecholamine exposure in an isoproterenol-induced (ISO) heart failure model. We set this study to determine the structural and functional consequences of CXCR4 myocardial knockout in the absence of exogenous stress. Cardiac phenotype and function were examined using (1) gated cardiac magnetic resonance imaging (MRI); (2) terminal cardiac catheterization with in vivo hemodynamics; (3) histological analysis of left ventricular (LV) cardiomyocyte dimension; fibrosis; and; (4) transition electron microscopy at 2-; 6- and 12-months of age to determine the regulatory role of CXCR4 in cardiomyopathy. Cardiomyocyte specific-CXCR4 knockout (CXCR4 cKO) mice demonstrate a progressive cardiac dysfunction leading to cardiac failure by 12-months of age. Histological assessments of CXCR4 cKO at 6-months of age revealed significant tissue fibrosis in knockout mice versus wild-type. The expression of atrial naturietic factor (ANF); a marker of cardiac hypertrophy; was also increased with a subsequent increase in gross heart weights. Furthermore, there were derangements in both the number and the size of the mitochondria within CXCR4 cKO hearts. Moreover, CXCR4 cKO mice were more sensitive to catocholamines, their response to ß-AR agonist challenge via acute isoproterenol (ISO) infusion demonstrated a greater increase in ejection fraction, dp/dtmax, and contractility index. Interestingly, prior to ISO infusion, there were significant differences in baseline hemodynamics between the CXCR4 cKO compared to littermate controls. However, upon administering ISO, the CXCR4 cKO responded in a robust manner overcoming the baseline hemodynamic deficits reaching WT values supporting our previous data that CXCR4 negatively regulates ß-AR signaling. This further supports that, in the absence of the physiologic negative modulation, there is an overactivation of down-stream pathways, which contribute to the development and progression of contractile dysfunction. Our results demonstrated that CXCR4 plays a non-developmental role in regulating cardiac function and that CXCR4 cKO mice develop a progressive cardiomyopathy leading to clinical heart failure.

Acute Renal Failure in Different Malignant Tumors.

Acute renal failure (ARF) represents a severe complication of malignancies, that causes significant morbidity and mortality. ARF is a common part of multiple organ dysfunction in critically ill patients with cancer with reported mortality rates from 72% to 85% in patients who need renal replacement therapy. The pathways leading to ARF in cancer patients are common to the development of ARF in other conditions. However, certain factors leading to the development of ARF may be associated to the tumor or to the tumor therapy. The purpose of this review is to give specific aspects of renal disease in critically ill cancer patients (CICPs), to overview the causes of ARF in CICPs and to describe recent progress in the management of these complications, including treatment toxicity and bone marrow transplantation (BMT). The prevention of ARF is obligatory and therefore the possible treatments of ARF in CICPs are also discussed.

Clear cell odontogenic carcinoma: report of a case and analysis of the literature.

BACKGROUND: Clear cell odontogenic carcinoma (CCOC), which has been described within the past 2 decades, is a rare odontogenic tumor that tends to occur in the mandible of older adults, with a predilection for women. It is potentially aggressive and capable of multiple local recurrences and locoregional and distant metastases. OBJECTIVES: To report the clinicopathologic findings and follow-up of a case of CCOC and to review the literature. DESIGN: Case report and literature review. MAIN OUTCOME MEASUREMENTS: Findings from histologic analysis, immunohistochemistry, and electron microscopy. RESULTS: An 81-year-old woman experienced 3 locoregional recurrences within 21 months of initial therapy. She is presently disease free, 4.5 years after initial resection, having received multiple resections and adjuvant radiotherapy. CONCLUSIONS: The diagnosis of CCOC must be considered in the differential diagnosis of jaw tumors with a clear cell component. For these tumors, resection with negative margins is the treatment of choice because more conservative surgery (eg, curettage) inevitably results in recurrence and/or metastasis. Adjuvant radiotherapy is a rational option for tumors that have eroded cortex.