Stress analysis of carotid atheroma in a transient ischaemic attack patient using the MRI-based fluid-structure interaction method

Rupture of atherosclerotic plaque is a major cause of mortality. Plaque stress analysis, based on patient-specific multisequence in vivo MRI, can provide critical information for the understanding of plaque rupture and could eventually lead to plaque rupture prediction. However, the direct link between stress and plaque rupture is not fully understood. In the present study, the plaque from a patient who recently experienced a transient ischaemic attack (TIA) was studied using a fluid-structure interaction method to quantify stress distribution in the plaque region based on in vivo MR images. The results showed that wall shear stress is generally low in the artery with a slight increase at the plaque throat owing to minor luminal narrowing. The oscillatory shear index is much higher in the proximal part of the plaque. Both local wall stress concentrations and the relative stress variation distribution during a cardiac cycle indicate that the actual plaque rupture site is collocated with the highest rupture risk region in the studied patient.

Complete mitochondrial genome of Cabot's tragopan, Tragopan caboti (Galliformes: Phasianidae)

Cabot's tragopan, Tragopan caboti, is a globally threatened pheasant endemic to southeast China. The complete mitochondrial genome of Cabot's tragopan was sequenced. The circular genome contains 16,727 bp, encoding a standard set of 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, plus the putative control region, a structure very similar to that of other Galliformes. As found in other vertebrates, most of these genes code on the H-strand, except for the NADH dehydrogenase subunit 6 (nad6) and eight tRNA genes (Gln, Ala, Asn, Cys, Tyr, Ser(UCN), Pro, Glu). All protein-coding genes initiated with ATG, except for cox1, which began with GTG, and had a strong skew of C vs G (GC skew = -0.29 to -0.73). One extra 'C' nucleotide was found in the NADH dehydrogenase subunit 3 (nad3). All the tRNA gene sequences have the potential to fold into typical cloverleaf secondary structures. Conserved sequences in three domains were identified within the control region (D-loop). These results provide basic information for phylogenetic analyses among Galliform birds, and especially Tragopan species.

Tanshinone IIA pretreatment protects myocardium against ischaemia/reperfusion injury through the phosphatidylinositol 3-kinase/Akt-dependent pathway in diabetic rats

AIM

Diabetes Mellitus (DM) is widely acknowledged to increase the risk of cardiovascular death, which warrants the use of aggressive primary prevention strategies. The aim of the present study was to investigate the pretreatment effects of tanshinone IIA (TSN), a traditional Chinese medicine, on myocardial infarct size, apoptosis, inflammation and cardiac functional recovery in diabetic rats subjected to myocardial ischaemia/reperfusion (I/R).

METHODS

Streptozocin (STZ) induced diabetic rats (n = 80) were randomized to receive TSN, TSN plus wortmannin [a phosphatidylinositol 3-kinase (PI3K) inhibitor] or saline. They were exposed to a 30-min ischaemia by ligation of the left coronary artery except for the sham group. Haemodynamics, infarct size and myocardial apoptosis were examined 3 h after reperfusion. The effects of TSN on Akt and NF-kappaB phosphorylation and the expression of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in cardiac tissues were examined.

RESULTS

Our results revealed that TSN administration significantly reduced myocardial infarct size (0.252 +/- 0.038 vs. 0.327 +/- 0.027, p < 0.05), improved left ventricular ejection fraction (LVEF) (0.774 +/- 0.058 vs. 0.716 +/- 0.054, p < 0.05), decreased myocardial apoptotic death (0.114 +/- 0.026 vs. 0.191 +/- 0.023, p < 0.05) compared with I/R group. Western blot analysis showed that TSN treatment enhanced Akt phosphorylation and inhibited NF-kappaB phosphorylation in cardiac tissues. Moreover, pretreatment with wortmannin abolished the beneficial effects of TSN: a reduction of infarct size, a decrease in LVEF, inhibition of myocardial apoptosis and Akt phosphorylation, enhancement of NF-kappaB phosphorylation and an increase of cytokine production including TNF-alpha and IL-6 after I/R injury in diabetic rats.

CONCLUSIONS

This study indicates that TSN pretreatment reduces infarct size and improves cardiac dysfunction after I/R injury in diabetic rats. This was accompanied with decreased cardiac apoptosis and inflammation. The possible mechanism responsible for the effects of TSN is associated with the PI3K/Akt-dependent pathway.

Heparin and suramin alter plitidepsin uptake via inhibition of GPCR coupled signaling

Plitidepsin (Aplidin) is a novel antitumor agent, derived from the mediterranean tunicate Aplidium albicans, and is currently in phase ii clinical trials with evidence of activity in heavily pretreated multiple myeloma, renal cell carcinoma, melanoma and neuroblastoma patients. As compared to its parental compound didemnin B, plitidepsin has shown a better therapeutic index with less bone marrow toxicity, cardiotoxicity and neurotoxicity in patients and a more potent cytotoxic effect in several tumor cell lines. As sensitivity to the drug varies between cell lines and fresh leukemia samples, we performed studies on transport of plitidepsin in leukemia and lymphoma cell lines to determine the mechanism of uptake. The drug is taken up by an active transport process, i.e. the process is temperature and energy dependent, and has a high-affinity binding site with Kt =212 nM and Vmax = 15 pmoles/min. Importantly, once inside the cell, efflux of plitidepsin is minimum, suggesting that the drug is bound to intracellular macromolecules. Further work showed that plitidepsin binds to G-Protein Coupled Receptors (GPCRs), since GPCR and GRK (GPCR kinases) inhibitors suramin and heparin respectively, markedly reduce the drug uptake and its cytotoxic activity. Signaling via Jak/Stat pathway is inhibited by pharmacological concentrations of plitidepsin, further confirming the relationship between plitidepsin and GPCRs.

Soluble Factors and Circulating Tumor Cells in Inflammatory Breast Cancer

Background: Inflammatory breast cancer (IBC) is an insidious form of breast cancer. Cytokines and chemokines direct the metastatic potential of disease and serve as biomarkers for disease progression. Circulating tumor cells (CTC) are an independent prognostic factor in metastatic disease. Further, TGF-β is involved in the induction of the epithelial-mesenchymal transition (EMT) which regulates the metastatic ability of IBC. As prognostic factors of aggressive disease, we measured serum cytokines and leukocyte phenotypes, and correlated the values with known CTC results of IBC and non-IBC patients.Methods: Peripheral blood (PB) from 35 IBC patients (18 non-metastatic and 17 metastatic) and 19 non-IBC patients (7 LABC, 12 MBC) was collected prior to starting a new therapy to measure a panel of 33 cytokines, chemokines, and growth factors in serum by Luminex; CTC by CellSearch™; and PB leukocyte immunophenotype by FACS. The Kruskal-Wallis and Mann-Whitney U tests determined the differences in cytokine levels between IBC, non-IBC and healthy donors (HD) and presence of CTCs.Results: There were no differences in serum cytokine, chemokine or growth factor levels between IBC and non-IBC patients. EGF, IP-10, MIG, Eotaxin, MCP-1 and TNF-RI were significantly elevated in breast cancer patients compared to HD. TNF-RI, EGF, HGF, IP-10, MIG, Eotaxin, MCP-1 and interleukin (IL)-10 were higher in IBC patients than in HD. Compared to IBC patients, non-IBC patients had fewer dysregulated cytokines relative to HD including higher EGF, Eotaxin, MCP-1 and IL-8.Perhaps counter-intuitively, non-metastatic IBC patients had higher plasma levels of IL-2, -2R, -4, -5, -10, -12p70, -15, -17, FGF-b, IFN-γ, GM-CSF, and MIP1-α than metastatic IBC patients. Moreover, these differences were not observed between LABC and MBC patients. Furthermore, compared to HD, metastatic IBC had lower IL-4, -7, -17, -12p70, IFN-γ, RANTES, but higher levels of IP-10, Eotaxin, MCP-1, and TNF-RI. These data suggest that non-metastatic IBC patients are more immune competent than metastatic IBC patients. Finally, there were differences in the immunophenotype as well as cytokine levels between IBC patients with and without CTCs. IBC patients with CTC had a lower %T-cells (p=0.003) and higher %B-cells (p=0.008) and TNF-RI (p=0.01) than IBC patients without CTCs which may lead to a decrease in cellular immunity. Cell-mediated immunity may be further compromised by the elevated levels of serum TGF-β (p= 0.064) that can also promote EMT and metastatic progression.Conclusion: We report a comprehensive analysis of the serum cytokine and chemokine profiles in IBC patients. More importantly, this is the first report of potential interactions between soluble factors, CTC, and immune parameters in IBC patients. Non-metastatic IBC patients are more immune competent than metastatic IBC patients as evidenced by the high levels of pro- and anti-inflammatory factors; however, the presence of CTC in IBC tends to shift the immune response to a TH2 polarization with a decrease in T-cells, and a concomitant increase in B-cells and serum TGF-β and TNF-RI levels. Additional studies are needed to determine the role of soluble factors in the pathogenesis and progression of IBC and the impact on clinical outcome.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2135.

Immune Profile of Inflammatory Breast Cancer Patients

Background: Inflammatory breast cancer (IBC) is characterized by an acute inflammation of the skin of the affected breast due to blockage of the dermal lymphatics by tumor emboli. Cytokines and chemokines affect the migration of tumor cells and immune cell function that regulates the pathogenesis of IBC. Preliminary data suggest that sera of IBC patients contain several inflammatory cytokines and chemokines capable of regulating innate and adaptive cellular immune responses. Since there is a paucity of data on the characteristics and function of immune cells of IBC patients, we determined the immunophenotype and cytokine production by T cells and dendritic cells.Methods: From October 2008 through May 2009, peripheral blood (PB) from 34 IBC patients (18 non-metastatic and 16 metastatic), 18 non-IBC patients and 24 healthy donors (HD) were analyzed to determine the immunophenotype of T-cell subsets, activated and regulatory T-cells, B-cells, natural killer cell subsets (NKC), and dendritic cell (DC) subsets. Additionally, we assessed the ability of T-cells and DCs to synthesize cytokines following activation through the T-cell receptor (TCR) and toll-like receptors (TLR), respectively. The Kruskal-Wallis and Mann-Whitney U tests determined the differences between IBC patients, non-IBC patients, and HD.Results: IBC and non-IBC patients were well-matched in terms of ER, PR, Her2, high-grade tumor, tumor size, and menopause status. Both IBC and non-IBC patients had significantly fewer lymphocytes, total T-cells (CD3+), T-helper (CD4+), T-cytotoxic/suppressor (CD8+), and B (CD19+) than HD (all p &lt; 0.01). Non-IBC patients had a significantly lower CD4/CD8 ratio than HD (p = 0.016) while IBC patients had significantly fewer T-regulatory (CD4+CD25hiCD127-) cells than HD (p = 0.02) and non-IBC patients (p &lt; 0.05). With respect to innate immunity markers, IBC patients also had significantly lower percentages of ADCC/NK (CD16+CD56+, p = 0.034) and non-exhaustive NK (CD56+CD57+, p = 0.02) than HD and a significantly higher percentage of non-ADCC/NK cells than non-IBC patients (p = 0.03). Non-IBC patients and HD had similar innate immunity markers. Even though all groups had similar percentages of myeloid (mDC) and plasmacytoid (pDC) dendritic cells, mDC of IBC patients displayed a higher level of constitutive activation than non-IBC with increased expression of CD40 and CD80, and decreased CCR5 expression. IBC patients had more mDC that constitutively produced TNF-a (p 0.041) and IL-10 (p = 0.029) than HD, and more mDC than non-IBC patients that produced IL-10 (p = 0.028).Conclusion: The immune profile of patients with breast cancer suggests multiple abnormalities involving T-, B-, NK- and dendritic cells. Furthermore, IBC patients exhibited constitutive immune activation as measured by increased expression of co-stimulatory receptors (CD80, CD40) and constitutive production of TNF-a and IL-10 by mDC as well as fewer T-regulatory cells. Taken together, these preliminary data suggest that IBC patients are more likely than non-IBC patients to have a dysregulated immune function. Additional studies on T-cell activation and function are warranted to better understand factors associated with host defense mechanisms of IBC patients and possible therapeutic strategies to restore immune function.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4129.

Down-Regulation of SHH/BMP4 Signalling in Human Anorectal Malformations

The sonic hedgehog homologue (SHH)/bone morphogenetic protein 4 (BMP4) signalling pathway is involved in the morphogenesis of many organ systems. This study was designed to investigate the expression of SHH/BMP4 pathway components in human anorectal malformations (ARMs) and the relationship between expression of their genes and the occurrence of ARMs. Expression of SHH, GLI family zinc finger 2 (GLI2) and BMP4 mRNA in the posterior wall of the terminal rectum in 40 patients with ARMs (15 high-type and 25 low-type) and 10 normal controls was assessed by reverse transcription-polymerase chain reaction. Levels of SHH, GLI2 and BMP4 proteins were assessed by immunohistochemistry and Western blotting. The expressions of SHH, GLI2 and BMP4 were significantly lower in patients with high-type compared with those with low-type anomalies and controls. Patients with low-type ARMs differed from controls only in the expression of GLI2 mRNA. It is concluded that down-regulation of the SHH/BMP4 signalling pathway may be related to the occurrence of high-type ARMs, but the mechanism responsible for low-type ARMs remains unclear.

New measurements of the European Muon Collaboration effect in very light nuclei

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.