Cardioprotection of exogenous erythropoietin in mice with ligature-induced aortic stenosis: effects on maladaptive cardiac hypertrophy

Pre-operative treatment with recombinant human erythropoietin may improve aortic stenosis patients' condition, including anemia and/or cardiac dysfunction, for subjecting to aortic valve replacement. In this study, we tested this hypothesis in a mouse model of aortic stenosis. Adult male mice were subjected to either aortic stenosis created by aortic ligature or sham operation. Aortic stenosis for 4 weeks caused cardiac hypertrophy, pulmonary congestion and left ventricular dysfunction. It was associated with increased levels of tumor necrosis factor-alpha in serum and myocardium, and reduced levels of interleukin-10 in myocardium but not in serum. Myocyte apoptosis rate, level of cleaved caspase 3, activity of nuclear factor-kappaB and expression of p38-MAPK pathway were also elevated. Erythropoietin treatment increased hematocrit but did not prevent the development of cardiac hypertrophy. It, however, reduced the apoptosis, prevented the increases in tumor necrosis factor-alpha, nuclear factor-kappaB activation and phosphorylation of p38, and attenuated the increases in lung weight, the decreases in LVEF and LVFS, and the increases in LVDd and LVDs. In conclusion recombinant human erythropoietin has cardioprotective effects in maladaptive cardiac hypertrophy by inhibiting nuclear factor-kappaB activation, phosphorylation of p38-MAPK pathway, and production of tumor necrosis factor-alpha, together leading to a reduced apoptosis.

Enhanced electroluminescence from SiN-based multilayer structure by laser crystallization of ultrathin amorphous Si-rich SiN layers

Luminescent SiN-based multilayers were prepared in a plasma enhanced chemical vapor deposition system followed by subsequently laser crystallization of ultrathin amorphous Si-rich SiN sublayers. The cross-sectional TEM analysis reveals that grain size of Si nanocrystals embedded in the Si-rich SiN sublayers is independent of the laser fluence, while the grain density can be well controlled by the laser fluence. The devices containing the laser crystallized multilayers show a low turn-on voltage of 5 V and exhibit strong green light emission under both optical and electrical excitations. Moreover, the device after laser-irradiated at 554 mJ/cm(2) shows a significantly enhanced EL intensity as well as external quantum efficiency compared with the device without laser irradiation. The EL mechanism is suggested from the bipolar recombination of electron-hole pairs at Si nanocrystals. The improved performance of the devices was discussed.

169 EMBRYO TRANSFER OF SEXED/VITRIFIED IVF EMBRYOS IN CATTLE: PREGNANCY COMPARISON AFTER SINGLE AND DOUBLE TRANSFERS

Advancement in sperm sorting technology combined with vitrification of in vitro produced bovine embryos will promote cattle breeding and production. The objective of this study was to evaluate pregnancy and embryo loss after embryo transfer (ET) of sexed/vitrified embryos with one bilaterally (double transfer, 2 embryos) v. ipsilaterally (single transfer, 1 embryo) into the recipient. Bovine oocytes collected from slaughterhouse ovaries or ovum pickup were matured for 20-22 h, then subjected to IVF using Brackett and Oliphant BO procedures with sorted X-sperm, and cultured with our standard culture system. Expanded blastocysts with tight compaction of the inner cell mass (quality 1) were selected on Day 7 for cryopreservation via liquid nitrogen surface vitrification (LNSV; Xu et al. 2006 J. Dairy Sci. 89, 2510-2518). Embryo transfer was performed for 3 replicates in Navasota, Texas, in April 2009. Prior to ET, embryos were warmed and subsequently washed several times in warming, dehydration solution and base medium. Some of sexed/vitrified embryos were cultured for 3 days post-warming to determine the survivability. The treatments were as follows: (1) vitrified-single transfers, 1 embryo was transferred into the horn ipsilateral to CL; (2) vitrified-double transfers, 1 embryo was transferred into each uterine horn by nonsurgical transfer; and (3) fresh-single, 1 fresh embryo was transferred into the horn ipsilateral to CL (control) to a synchronous recipient on Day 7. Pregnancy was determined by ultrasound monitoring on Day 35, and palpation per rectum on Day 75 after transfer. The pregnancy data were analyzed by General Linear Model analysis (SPSS 11.0, SPSS Inc., Chicago, IL, USA). The survival rate of vitrified IVF embryos reached to as high as 97.6% (n = 42) 2 h post-warming, and hatching rate was 85.7% after 3 days culture in vitro. The data (Table 1) showed that there was no difference in Day 35 pregnancy rate among vitrified-double, vitrified-single, and fresh ET control groups. However, on Day 75 post-ET, there was a significantly higher fetal loss found in the vitrified-double transfer group (41.1%) compared to those of vitrified-single transfers (16.6%) and fresh-single group (11.9%) (P < 0.05). The pregnancy rate on Day 75 of 51.4% achieved with vitrified-single transfers was comparable to the 43.3% achieved with the fresh-single control transfers but was significantly higher than the 31.1% of the vitrified-double transfer group. This study demonstrated that double embryo transfers can aggravate high fetal loss and/or abortion when sexed IVF embryos are transferred, and ET with 1 sexed/vitrified embryo per recipient is sufficient to establish satisfactory pregnancy, comparable to that achieved with fresh embryos. Table 1.Pregnancy and fetal loss of sexed/vitrified bovine IVF embryos following single and double transfers Supported by USDA/CSREES-SBIR: 2006-03069 Phase II to F. Du.

81 THE EFFECT OF FOLLICULAR AND OVIDUCT OOCYTES ON THE DEVELOPMENT OF RABBIT NUCLEAR TRANSFERRED EMBRYOS IN VITRO

This study was designed to examine the effect of rabbit oocytes collected from oviducts v. follicles on the developmental potential of nuclear transplant (NT) embryos. Rabbit oocytes were flushed from the oviducts (oviduct oocytes) or collected from the ovarian Graafian follicles(follicular oocytes) of superovulated does at 12 h post-hCG injection (hpi). Cumulus cells were then removed from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in TCM-199 +10% fetal bovine serum (FBS) and confirmed under fluorescent microscopy. Skin fibroblasts from an adult rabbit were prepared and cultured to passage 8 to 10 before use as nuclear donors. A donor cell with a diameter of approximately 15 to 19 μm was transferred into the perivitelline space of an enucleated oocyte and subsequently fused with the recipient oocyte by applying 3 direct current pulses at 3.2 kV cm-1 for 20 μs per pulse. Fused oocytes were activated by the same electrical stimulation described above, and then cultured in TCM-199 + 10% FBS containing 2.0 mM 6-DMAP and 5 μg mL-1 cycloheximide for 1 h. Cloned embryos were cultured in 2.5% FBS B2 medium in 5% CO2 and 95% humidified air at 38.5°C for 3 d. Embryo development to cleavage (2- to 4-cell), 8-cell, and morula/blastocyst (Mor/BL) stages was evaluated. The data were analyzed by the General Linear Model procedure (SPSS 11.0, SPSS Inc., Chicago, IL, USA).The total number of oocytes collected per animal was 27.6 ± 1.3, with 47.8% from oviducts, and 52.2% from follicles. The percentage of oviduct oocytes that showed the first polar body was 98.3% (n = 150) at the time of collection, whereas follicular oocytes only had 54.8% at collection (n = 93), but it reached 92.4% when immature follicular oocytes were cultured for 3 h in vitro. The enucleation rates were similar between the follicular (82.7%) and the oviduct (79.1%) groups. Table 1 shows that a significantly higher fusion rate was found in follicular oocytes compared with that in the oviduct group (90.8 v. 63.4%; P < 0.05). There was no difference in the cleavage rate and Mor/BL development between the 2 groups, although the 8-cell(78.4 v. 63.9%; P = 0.11) and the overall efficiencies (30.6% v. 17.9%; P = 0.14) appeared higher in the follicular group. These results demonstrated that rabbit follicular oocytes at 12 hpi have potential equivalent or maybe better (fusion) than that with oviduct oocytes for promoting the preimplantational development of NT embryos. Table 1.The effect of follicular and oviduct oocytes on the development of rabbit NT embryos Supported by NIH1R43 RR023774-01A1 and 5R44HL091605-03.

157 AGGREGATION AND DEVELOPMENT OF RABBIT CLONED EMBRYOS WITH ZYGOTIC, TETRAPLOID, AND PARTHENOGENETIC EMBRYO IN VITRO

The rabbit compared to other domestic animals, such as cattle and sheep, was a relatively more difficult species to clone. One of the major reasons may be attributed to the low cell number in cloned embryo before implantation. This study was designed to aggregate 2 nuclear transfer (NT) embryos and one with a different origin, determine their developmental potential in vitro, and finally examine the cell number of aggregated embryos. NT was performed with our standard procedure using in vivo derived oocytes and donor cells from adult skin fibroblasts. Zygotes (ZY) were collected from does at 18 h post-hCG and mating. Parthenogenetic (PA) embryos were generated from oocytes with activation protocol, whereas tetraploid embryos (4N) were prepared by fusing fertilized embryos at 2-celled stage into 1-celled stage by electrical pulse. All of the embryos were cultured for 20-24 h into 4-/8-celled stage prior to aggregation. Zona pellucida was then removed and 2 NT embryos were aggregated with 1 embryo originated from ZY, PA, and 4N groups in a depressed droplet containing culture medium. Aggregated embryos were cultured for another 48 h (total 3 days, initiation of activation = Day 0) before being fixed for cell counting. Both single embryo from NT, ZY, PA, and 4N and 3 embryo aggregates (3X) from the same category were used as controls for NT aggregation. The results of 3-day embryo culture in vitro showed that the development of aggregated embryos to blastocyst (BL) stage was 2 NT + ZY, 68.6% (n = 35); 2 NT + 4N, 91.7% (n = 36); and 2 NT+PA, 37.5% (n = 24), whereas 3X aggregates developed to BL at a rate of ZY, 100% (n = 24); 4N, 100% (n = 19); and PA, 100% (n = 14). The BL rates of single embryo control developed into early BL were ZY, 100% (n = 34) and 4N, 93% (n = 36); however, NT and PA developed slower, only 45.4% NT (n = 187) and 79.2% PA (n = 72) to compacted morula/early BL stage. Cell counting data (Table 1) showed that there was no difference in cell number per embryo between NT and PA, whereas ZY and 4N possessed significantly higher cell number than NT and PA (128-162 v. 52-61, P < 0.05) for single embryo category. In the 3X aggregation group, significantly higher cell number per aggregated embryo was found in ZY and 4N compared to that in PA (549-564 v. 196, P < 0.05). More importantly, there was significantly higher cell number found in 2 NT + 4N embryo than that in single 4N (293 v. 162, P < 0.05). This result demonstrated that 2 cloned embryos had propagated and incorporated into 1 tetraploid embryo during pre-implantational development. The next step is to study how NT embryos successfully interact within the aggregated embryo during further development and differentiation, in order to increase the birth rate of clones. Table 1.The cell number of aggragated rabbit embryos between NT and other embryos of different origin after 3 days of culture in vitro Supported by NIH 5R44HL091605-03.

Inflammation, innate immunity and blood coagulation

Inflammation drives arterial, venous and microvascular thrombosis. Chronic inflammation contributes to arterial thrombotic complications, whereas acute inflammation drives venous thrombosis and microvascular thrombosis. Mechanistically, inflammation modulates thrombotic responses by upregulating procoagulants, downregulating anticoagulants and suppressing fibrinolysis. The inflammatory response can also result in cell apoptosis or necrosis. Products released from the dead cells, particularly histones, propagate further inflammation, tissue death and organ failure. Inhibition of histone mediated cytotoxicity appears to be a new mechanism for protecting against this deadly cascade.

98 EIGHT-CELL STAGE DELINEATES CRYOTOLERANCE OF VITRIFIED RABBIT EMBRYOS

A number of groups have successfully vitrified rabbit embryos at morula or blastocyst (BL) stage. For earlier stages (1- to 8-celled), however, there are very limited studies and the results are generally unsatisfactory. In this study, we examined the survival and developmental competence of rabbit embryos vitrified at different preimplantational stages. Sexually matured female New Zealand White (NZW) rabbits were superovulated with our standard protocols, followed by mating with NZW males. At 18h post-hCG treatment, viable fertilized embryos were collected and cultured in 2.5% FBS B2 medium (Laboratories CCD, Paris, France) in 5% CO2 with humidified air at 38.5°C. A total of 691 rabbit embryos at pronuclear, 2-celled, 4-celled, 8-celled, and morula/early blastocyst (BL; Day 3) stages were vitrified by the open pulled straw (OPS) method in HEPES buffered TCM-199 medium containing 20% fetal calf serum, ethylene glycol, and dimethyl sulfoxide. After stored in liquid nitrogen for at least 1 month, embryos were sequentially warmed, rehydrated, and washed before culture in B2 culture medium. Survival and developmental rates were analyzed by general linear model analysis (SPSS 11.0, SPSS Inc., Chicago, IL, USA). Embryos vitrified at 8-celled stage or beyond showed greater survival, and expanded BL and hatching rates than those at pronuclear, 2-celled and 4-celled embryos (Table 1). In particular, the expanded and hatched BL rates were significantly higher in the 8-celled group than those in 4-celled group, suggesting that the 8-celled is the threshold stage to tolerate the vitrification procedure in rabbit embryos. In addition, the rates of expanded and hatched blastocysts in morula/BL group were still significantly higher than those in the 8-celled group. Our results may provide the proper timing of cryopreserving fertilized, transgenic, and/or cloned rabbit embryos at early stages for biomedical research. Table 1.Survival and developmental competence of rabbit embryos vitrified at different stages after thawing This study was supported by NIH1R43 RR023774-01A1 and 5R44HL091605-03.

Differential near-field scanning optical microscopy with THz quantum cascade laser sources

We have realized a differential Near-field Scanning Optical Microscope (NSOM) working with subwavelength resolution in the THz spectral region. The system employs a quantum cascade laser emitting at lambda approximately 105 microm as source, and the method, differently from conventional NSOM, involves diffracting apertures with size comparable to the wavelength. This concept ensures a higher signal-to-noise level at the expense of an additional computational step. In the implementation here reported lambda/10 resolution has been achieved; present limiting factors are investigated through finite difference time domain simulations.

A Single Nucleotide Polymorphism in Steroid Receptor Coactivator-1 Diminishes the Coactivation of ERα

Estrogen signaling is critical in the progression of a large fraction of breast cancers as well as in the maintenance of bone mineral density. Generally speaking, Tamoxifen, a selective estrogen receptor modulator (SERM), blocks estrogen signaling in the breast by acting as an antagonist at the same time as promoting estrogen signaling in the bone by acting as an agonist. This tissue specific action characteristic of SERMs is thought to be maintained by the balance of levels and/or activities of estrogen receptor (ER) coregulators. Because of this critical role, single nucleotide polymorphisms (SNPs) in ER coregulators could have a dramatic effect on tamoxifen action.Previous studies have implicated steroid receptor coactivator-1 (SRC-1) as a critical coregulator for the mixed antagonist-agonist specificity of tamoxifen. By using an ERE-Tk-Luciferase transient transfection assay, we have shown that a SNP causing the amino acid change P1272S in SRC-1 dramatically reduces its ability to coactivate ERα.To assess the impact of this SNP on tamoxifen action in breast cancer we decided to genotype the SRC-1 P1272S SNP in a breast tumor DNA bank. This bank was generated from archived tumors from individuals either exclusively receiving adjuvant tamoxifen or not receiving any adjuvant therapy following surgical resection. Currently, the bank is composed of 1000 samples divided equally among the two groups. Genotyping for the SRC-1 P1272S SNP is currently underway.Since SRC-1 has also been shown to be important in proper maintenance of bone mineral density (BMD) and in the agonist action of tamoxifen in certain tissues, we also assessed the impact of the P1272S SNP in bone following tamoxifen therapy. We genotyped breast cancer patients exclusively receiving tamoxifen therapy (i.e. no chemotherapy, no radiation) who had lumbar (n=113) and/or hip (n=108) BMD scans before and after 12 months of tamoxifen therapy. We observed a significant association between the SNP and bone loss; women harboring the P1272S SNP lost 6.4% of their lumbar BMD, while women with the WT version lost only 1.3% of their lumbar BMD.These findings illustrate the critical role of SRC-1 in tamoxifen action in bone, and potentially other hormone responsive tissues. Studies are ongoing to decipher the mechanism for decreased coactivation activity of the SNP, and also to extend the clinical association studies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 66.

Computerized Histologic Image-Based Risk Score (IbRiS) Classifier for ER+ Breast Cancer

Background: Measurement of estrogen receptor (ER) expression is a routine part of clinical evaluation of individual breast cancers and is used to guide treatment. However not all ER+ breast cancers show equal benefit from hormonal or other treatment. The RT-PCR based Oncotype Dx assay, has been recently shown to robustly stratify early stage ER+ breast cancer and identify those tumors that will have low recurrence rates when treated with adjuvant hormonal therapy alone. Interestingly, standard pathologic grading, based on visual analysis of tumor morphology by trained pathologists, has a strong correlation with Oncotype Dx recurrence scores; low recurrence tumors are mostly low grade, and high recurrence tumors are mostly high grade. However, a major problem with use of pathologist-assigned histologic grade as a prognostic tool is the lack of reproducibility of histological grading between different pathologists. Computer aided image analysis and machine learning techniques offer a way to obtain highly reproducible image-based classification of ER+ breast cancer. These analyses can be performed on digital images of routinely obtained breast cancer histology and be incorporated into a prognostic assay.Materials and Methods: High resolution digital images were obtained for a series of ER+ breast cancers for which associated Oncotype Dx Assay results were available. Regions of invasive breast cancer were identified and then processed by computer-assisted image analysis methods. An automated nuclear detection scheme based on Expectation Maximization algorithm was used to identify cancer cell nuclei, followed by graph-based feature extraction using the Voronoi graph, Delaunay Triangulation and Minimum Spanning Trees, and dimensionality reduction using Graph Embedding with Support Vector Machine based classification. The final manifold generated by GE was unwrapped into a linear space and a Euclidean distance metric was used to generate a single score (Image Based Risk Score- (IbRiS)) for each sample. Correlations between IbRS, clinical features such as grade, and Oncotype Dx Recurrance Score were determined.Results: Unsupervised analysis of image-based features of high resolution digital images of ER+ breast cancer histology leads to natural separation of tumors, with low grade tumors separating from high grade tumors. There is also a robust separation of tumors with high Oncotype Dx Recurrance Scores from tumors with low Recurrance Scores.Discussion: Unsupervised analysis of high resolution image-based features can stratify ER+ breast cancers in a fashion that correlates well with a gene-expression based prognostic assay, Oncotype Dx. These data suggest that tumors with distinct gene-expression profiles also have distinct image-based features that can be measured by computer-aided image analysis and used to build prognostic and predictive assays.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3046.

Comparison of risk factors associated with hypertension subtypes by classification tree method in Tongshan County of Jiangsu Province, China

BACKGROUND

There are only a very limited number of studies relating to risk factors for hypertension in rural populations in China. There are even fewer studies comparing various hypertension subtypes.

METHODS

A cross-sectional investigation was carried out in a representative sample of 20,390 subjects drawn from among 1,180,000 adult residents of Tongshan County of Jiangsu Province, China. The impact of risk factors including demographic, socioeconomic, dietary, and behavioral, on three hypertension subtypes, namely, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH), was analyzed by applying statistical tests and a classification tree.

RESULTS

ISH was the predominant untreated hypertension subtype (13.68 +/- 0.24%) in the adults of Tongshan County, followed by SDH (11.70 +/- 0.23%) and IDH (6.24 +/- 0.17%). Age, number of cigarettes smoked daily, and the types of vitamins taken varied among the ISH, IDH, and SDH classification trees. Low socioeconomic status was associated with an increased risk for ISH and SDH. Light alcohol intake was associated with higher risk for ISH, but with lower risks for IDH and SDH. Light cigarette smoking was associated with higher ISH risk but lower SDH risk. The intake of appropriate amounts of fish, shrimp, or meat lowered the risks for ISH and IDH. The intake of appropriate amounts of seafood, eggs, milk, or fruit lowered the risks for all hypertension subtypes. Interestingly, an excessive preference for sweet or salty foods was associated with a higher risk for all the subtypes.

CONCLUSIONS

In Tongshan County, there was a considerable prevalence of hypertension of various subtypes, each associated with distinctive and complex risk factors. This suggests that there is a need for testing more diverse prevention measures, tailored to specific subtypes.