A review of the development and implementation of a 4-year medical student integrated ultrasound curriculum is presented. Multiple teaching and assessment modalities are discussed as well as results from testing and student surveys. Lessons learned while establishing the curriculum are summarized. It is concluded that ultrasound is a well received, valuable teaching tool across all 4 years of medical school, and students learn ultrasound well, and they feel their ultrasound experience enhances their medical education.

Objective microRNA-155 (miR155) plays a critical role in immunity and macrophage inflammation. We aim to investigate the role of miR155 in atherogenesis. Approach and Results Quantitative real-time PCR showed that miR155 was expressed in mouse and human atherosclerotic lesions. miR155 expression in macrophages was positively correlated with proinflammatory cytokine expression. Lentivirus-mediated overexpression of miR155 in macrophages enhanced their inflammatory response to LPS through targeting SOCS-1, and impaired cholesterol efflux from acetylated LDL-loaded macrophages, whereas deficiency of miR155 blunted macrophage inflammatory responses, and enhanced cholesterol efflux possibly via enhancing lipid loading-induced macrophage autophagy. We next examined the atherogenesis in apoE−/− and miR155−/−/apoE−/− (DKO) mice fed a western diet. Compared with apoE−/− mice, the DKO mice developed less atherosclerosis lesion in aortic root, with reduced neutral lipid content and macrophages. Flow cytometric analysis showed that there were increased number of regulatory T cells, and reduced numbers of Th17 cells and CD11b+/Ly6Chigh cells in the spleen of DKO mice. Peritoneal macrophages from the DKO mice had significantly reduced pro-inflammatory cytokine expression and secretion both in the absence and presence of LPS stimulation. To determine whether miR155 in leukocytes contributes to atherosclerosis, we performed bone marrow transplantation study. Deficiency of miR155 in bone marrow-derived cells suppressed atherogenesis in apoE−/− mice, demonstrating that hematopoietic cell-derived miR155 plays a critical role. Conclusion miR155 deficiency attenuates atherogenesis in apoE−/− mice by reducing inflammatory responses of macrophages, enhancing macrophage cholesterol efflux and resulting in an anti-atherogenic leukocyte profile. Targeting miR155 may be a promising strategy to halt atherogenesis.

Colorectal cancer risk is increased in shift workers with presumed circadian disruption. Intestinal epithelial cell proliferation is gated throughout each day by the circadian clock. Period 2 (Per2) is a key circadian clock gene. Per2 mutant (Per2m/m) mice show an increase in lymphomas and deregulated expression of cyclin D and c-Myc genes that are key to proliferation control. We asked whether Per2 clock gene inactivation would accelerate intestinal and colonic tumorigenesis. The effects of PER2 on cell proliferation and β-catenin were studied in colon cancer cell lines by its down-regulation following RNA interference. The effects of Per2 inactivation in vivo on β-catenin and on intestinal and colonic polyp formation were studied in mice with Per2 mutation alone and in combination with an Apc mutation using polyp-prone ApcMin/+ mice. Down-regulation of PER2 in colon cell lines (HCT116 and SW480) increases β-catenin, cyclin D, and cell proliferation. Down-regulation of β-catenin along with Per2 blocks the increase in cyclin D and cell proliferation. Per2m/m mice develop colonic polyps and show an increase in small intestinal mucosa β-catenin and cyclin D protein levels compared with wild-type mice. ApcMin/+Per2m/m mice develop twice the number of small intestinal and colonic polyps, with more severe anemia and splenomegaly, compared with ApcMin/+ mice. These data suggest that Per2 gene product suppresses tumorigenesis in the small intestine and colon by down-regulation of β-catenin and β-catenin target genes, and this circadian core clock gene may represent a novel target for colorectal cancer prevention and control.

Lung cancer is the leading cause of cancer-related deaths with current chemotherapies lacking adequate specificity and efficacy. β-Lapachone (β-lap) is a novel anticancer drug that is bioactivated by NAD(P)H:quinone oxidoreductase 1, an enzyme found specifically overexpressed in non-small cell lung cancer (NSCLC). Herein, we report a nanotherapeutic strategy that targets NSCLC tumors in two ways: (a) pharmacodynamically through the use of a bioactivatable agent, β-lap, and (b) pharmacokinetically by using a biocompatible nanocarrier, polymeric micelles, to achieve drug stability, bioavailability, and targeted delivery. β-Lap micelles produced by a film sonication technique were small (∼30 nm), displayed core-shell architecture, and possessed favorable release kinetics. Pharmacokinetic analyses in mice bearing subcutaneous A549 lung tumors showed prolonged blood circulation (t 1/2 , ∼28 h) and increased accumulation in tumors. Antitumor efficacy analyses in mice bearing subcutaneous A549 lung tumors and orthotopic Lewis lung carcinoma models showed significant tumor growth delay and increased survival. In summary, we have established a clinically viable β-lap nanomedicine platform with enhanced safety, pharmacokinetics, and antitumor efficacy for the specific treatment of NSCLC tumors. Cancer Res; 70(10); 3896-904. ©2010 AACR.

We examined the effects of three high‐fat diets differing in the percentage of total calories from saturated fat (SF) (6%, 12%, and 24%), but identical in total fat (40%), on body composition, macrophage behavior, inflammation, and metabolic dysfunction in mice. Diets were administered for 16 weeks. Body composition and metabolism (glucose, insulin, triglycerides, LDL‐C, HDL‐C, total cholesterol) were examined monthly. Adipose tissue (AT) expression of marker genes for M1 and M2 macrophages and inflammatory mediators (TLR‐2, TLR‐4, MCP‐1, TNF‐α, IL‐6, IL‐10, SOCS1, IFN‐γ) was measured along with activation of NFκB, JNK and p38‐MAPK. AT macrophage infiltration was examined using immunohistochemistry. Circulating MCP‐1, IL‐6, adiponectin, and leptin were also measured. SF content, independent of total fat, can profoundly affect adiposity, macrophage behavior, inflammation, and metabolic dysfunction. In general, the 12%‐SF diet, most closely mimicking the standard American diet, led to the greatest adiposity, macrophage infiltration, and insulin resistance (IR), whereas the 6%‐SF and 24%‐SF diets produced lower levels of these variables with the 24%‐SF diet resulting in the least degree of IR and the highest TC/HDL‐C ratio. Macrophage behavior, inflammation and IR following HFDs are heavily influenced by dietary SF content, however, these responses are not necessarily proportional to the SF%. This work was supported by an ASPIRE (Advanced Support Programs for Innovative Research Excellence) grant from the University of South Carolina to E.A.M. Grant Funding Source: ASPIRE

Tumor-associated macrophages are associated with poor prognosis in certain cancers. Monocyte chemoattractant protein 1 (MCP-1) is thought to be the most important chemokine for recruitment of macrophages to the tumor microenvironment. However, its role on tumorigenesis in a genetic mouse model of colon cancer has not been explored. We examined the role of MCP-1 on tumor-associated macrophages, inflammation, and intestinal tumorigenesis. Male Apc Min/+, Apc Min/+/MCP-1−/− or wild-type mice were euthanized at 18 wk of age and intestines were analyzed for polyp burden, apoptosis, proliferation, β-catenin, macrophage number and phenotype, markers for cytotoxic T lymphocytes and regulatory T cells, and inflammatory mediators. MCP-1 deficiency decreased overall polyp number by 20% and specifically large polyp number by 45% ( P < 0.05). This was consistent with an increase in apoptotic cells ( P < 0.05), but there was no change detected in proliferation or β-catenin. MCP-1 deficiency decreased F4/80-positive cells in both the polyp tissue and surrounding intestinal tissue ( P < 0.05) as well as expression of markers associated with M1 (IL-12 and IL-23) and M2 macrophages (IL-13, CD206, TGF-β, and CCL17) ( P < 0.05). MCP-1 knockout was also associated with increased cytotoxic T lymphocytes and decreased regulatory T cells ( P < 0.05). In addition, MCP-1−/− offset the increased mRNA expression of IL-1β and IL-6 in intestinal tissue and IL-1β and TNF-α in polyp tissue ( P < 0.05), and prevented the decrease in SOCS1 expression ( P < 0.05). We demonstrate that MCP-1 is an important mediator of tumor growth and immune regulation that may serve as an important biomarker and/or therapeutic target in colon cancer.

Monocyte chemoattractant protein 1 (MCP-1) has an important influence on monocyte migration into sites of inflammation. Our understanding of the signal transduction pathways involved in the response of monocytes to MCP-1 is quite limited yet potentially significant for understanding and manipulating the inflammatory response. Prior studies have demonstrated a crucial regulatory role for cytosolic phospholipase A2 (cPLA2) in monocyte chemotaxis to MCP-1. In these studies we investigated the role for another PLA2, calcium-independent PLA2 (iPLA2) in comparison to cPLA2. Pharmacological inhibitors of PLA2 were found to substantially inhibit chemotaxis. Using antisense oligodeoxyribonucleotide treatment we found that iPLA2 expression is required for monocyte migration to MCP-1. Complete blocking of the chemotactic response was observed with inhibition of either iPLA2 or cPLA2 expression by their respective antisense oligodeoxyribonucleotide. In reconstitution experiments, lysophosphatidic acid completely restored MCP-1-stimulated migration in iPLA2-deficient monocytes, whereas lysophosphatidic acid was without effect in restoring migration in cPLA2-deficient monocytes. To the contrary, arachidonic acid fully restored migration of cPLA2-deficient monocytes while having no effect on the iPLA2-deficient monocytes. Additional studies revealed that neither enzyme appears to be upstream of the other indicating that iPLA2 and cPLA2 represent parallel regulatory pathways. These data demonstrate novel and distinct roles for these two phospholipases in this critical step in inflammation.

A novel approach to treat ischemic tissues by using gene therapy has recently been introduced on the basis of the angiogenic potential of certain growth factors. The authors investigated the effect of adenovirus-mediated gene therapy with vascular endothelial growth factor (VEGF) delivered into the subdermal space to treat compromised skin flaps. For this purpose, the epigastric skin flap model in rats, based solely on the right inferior epigastric vessels, was used. Thirty male Sprague-Dawley rats were divided into five groups of six rats each. Viral transfection with 108 plaque-forming units was performed 2 days before the epigastric flap elevation. Rats received subdermal injections of adenovirus encoding VEGF (Ad-VEGF) or green fluorescent protein (Ad-GFP) as treatment control. Another set of animals (n = 6) received no injections and were designated as control. To determine whether site of injection had an impact on flap viability, injections were given into the predicted local ischemic area (Ad-VEGF local, n = 6; Ad-GFP local, n = 6) and into the midline of the flap (Ad-VEGF midline, n = 6; Ad-GFP midline, n = 6). A flap measuring 8 x 8 cm was outlined on the abdominal skin extending from the xiphoid process proximally and the pubic region distally, to the anterior axillary lines bilaterally. Then, the epigastric flap was elevated as an island on the right inferior epigastric vessels and sutured back to its bed. Flap viability was evaluated at 7 and 14 days after the first operation. The epigastric flaps were scanned to the computer and areas of hypoxic and/or necrotic zones relative to total flap surface area were measured and expressed as percentages by using Image Pro Plus software. Specimens were taken for histologic evaluation at day 14 before the animals were killed. Combined area of necrotic and hypoxic zones as well as necrotic zone were decreased to 9.7 +/- 1.4 percent and 1.4 +/- 0.9 percent in Ad-VEGF local, and 11.8 +/- 1.9 percent and 3.5 +/- 1.64 percent in Ad-VEGF midline compared with the control and Ad-GFP treatment groups (control, 23 +/- 3.6 percent and 20.1 +/- 3.3 percent; Ad-GFP local, 24.8 +/- 4.8 percent and 16.2 +/- 5.9 percent; and Ad-GFP midline, 23.4 +/- 6.9 percent and 19.5 +/- 7.7 percent; p < 0.05). Histologic evaluation by light microscopy failed to demonstrate any quantitative difference in vascularity of skin flaps between the treatment groups. In this study, the authors demonstrated that adenovirus-mediated gene therapy using VEGF enhanced epigastric skin flap survival, as confirmed by the significant reduction in combined area of necrotic and hypoxic zones of the flap. Compared with the control, both local and midline subdermal injections of Ad-VEGF showed improvement in overall flap survival by 57.9 and 48.7 percent, respectively. The results of this study raise the possibility of using adenovirus-mediated therapeutic angiogenesis for safer flap surgery in high-risk patients.