388 OPTIMIZATION OF INDUCED PLURIPOTENT STEM CELL GENERATION FROM BOVINE FIBROBLASTS

Difficulties associated with isolation and culturing bovine embryonic stem (ES) cells has led to the exploration of alternative methods for generating pluripotent stem cells. The viral delivery of reprogramming factors Oct4, Sox2, cMyc, and Klf4 has resulted in generation of induced pluripotent stem cells (iPS) in rodent, human, rhesus monkey, and pig somatic cells. In the current study, we improved the efficiency of retroviral transduction of bovine adult fibroblasts (BAF) for the generation of bovine iPS cells. Bovine adult fibroblasts were transduced with 4 human factors: Oct 4, Sox 2, cMyc, and Klf4. To determine transfection efficiency, pMXs-GFP was used as a reporter. The effect of change in cell density of the Platinum A retroviral packaging cell line (Plat A), cell densities of the target BAF, and infection regimes on the transfection rates was examined. A reduction in Plat A cell density from 8 × 106 to 2 × 106 did not alter transfection rates. Reduced target cell density from 4 × 105 to 4 × 104 (10-fold) improved the transfection rates from 0.31 to 7.06%, P < 0.001 (n = 3). Subjecting the BAF to 2 sequential rounds of viral transduction further improved the transfection rates to 13.88%, P < 0.001 (n = 3). These preliminary results suggest that optimizing the density of target cells can greatly improve transduction outcomes. Following viral induction with the 4 reprogramming factors, putative bovine iPS colonies were observed when the transfection rate was >1%. The putative bovine iPS cells were cultured in alpha-minimal essential medium supplemented with 20% FCS and 10 ng mL-1 human leukemia inhibitory factor. These putative bovine iPS colonies had mouse ES-like morphology, were multilayered, and had high nucleus-to-cytoplasmic ratio. They stained positive for alkaline phosphatase activity. The colonies were manually passaged onto mitomycin C-inactivated mouse embryonic fibroblasts every 5 to 7 days but could only be expanded for a limited number of passages. Other strategies are currently being explored to improve stable reprogramming of BAF such as epigenetic modification of cells, lentivirus-mediated transduction, and investigation of media suitable to maintain putative bovine iPS colonies for further characterization including RT-PCR or immunohistochemical detection for pluripotent markers and in vivo differentiation ability. Acknowledgments are given to Dairy Australia.

Central mucoepidermoid carcinoma of the maxilla: a case report

BACKGROUND AND OBJECTIVE

Primary mucoepidermoid carcinoma of the jaw is a rare lesion, comprising 2-3% of all mucoepidermoid carcinomas reported in literature. Central mucoepidermoid carcinoma of the maxilla is rarer, comprising only 8% of the mucoepidermoid carcinomas found in the jaw.

METHODOLOGY

A 52-year-old man suffered from central mucoepidermoid carcinoma of the right maxilla with cervical metastasis, and underwent partial maxillectomy and neck dissection in our hospital. The diagnosis was confirmed by histopathology, dental orthopantomography, CT, and PET/CT scans.

RESULT

The man was followed-up regularly and was disease free after 21 months.

CONCLUSION

Primary central mucoepidermoid carcinoma of the jaw is a rare lesion and radical surgical resection is the preferred treatment.

Endovascular treatment of wide-neck middle cerebral artery aneurysms with stents: a review of 16 cases

BACKGROUND AND PURPOSE

MCA aneurysms are common and often pose technical challenges to interventionalists. Intracranial stents are widely used in treating wide-neck aneurysms in other locations. To evaluate the feasibility, effectiveness, and safety of stent placement in MCA aneurysms, we performed this retrospective study.

MATERIALS AND METHODS

Between October 2003 and May 2009, 16 patients with 16 wide-neck MCA aneurysms were treated with stents at our institution. We retrospectively collected and analyzed the data for these patients, including demographics, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

Seventeen stents, including 12 Neuroform, 4 LEO, and 1 Enterprise, were successfully deployed in this series. Of the 13 aneurysms treated with stent-assisted embolization, complete occlusion was achieved in 9 aneurysms; residual neck remained in 1, and residual aneurysm was present in 3. Contrast stasis in the aneurysm sac was observed in the other 3 aneurysms treated with stent alone. Procedure-related complication occurred in 1 patient, leading to no permanent effect. The mRS score at discharge was 0-2 in 14 patients and 3-6 in 2. The angiographic follow-up results of 9 patients (mean, 5.6 months) showed that all aneurysms remained stable or improved; there was no in-stent stenosis, recurrence, or retreatment. The clinical follow-up (mean, 20.1 months) demonstrated no neurologic deterioration or rebleeding.

CONCLUSIONS

Our preliminary experience demonstrates that stent placement for the treatment of selected wide-neck MCA aneurysms is feasible. However, its safety and efficacy should be further evaluated by larger case series and more adequate follow-up.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Activity identification of chimeric anti-caspase-3 mRNA hammerhead ribozyme in vitro and in vivo

To study the expression activity of various vectors containing anti-caspase-3 ribozyme cassettes in vivo, and to further study the role of caspas-3 in the apoptotic pathway, we constructed anti-caspase-3 hammerhead ribozyme embedded into the human snRNA U6, and detected the activity of the ribozyme in vitro and in vivo. Meanwhile we compared it with the self-cleaving hammerhead ribozymes that we previously studied, and with the general ribozyme, cloned into RNA polymerase II expression systems. The results showed that the three ribozymes, p1.5RZ107, pRZ107 and pU6RZ107 had the correct structure, and that they could cleave caspase-3 mRNA exactly to produce two fragments: 143nt/553nt. p1.5RZ107 has the highest cleavage efficiency in vitro, almost 80%. However, the U6 chimeric ribozyme, pU6RZ107, has the highest cleavage activity in vivo, almost to 65%, though it has lower cleavage activity in vitro. The cleavage results demonstrated that the pU6RZ107, the U6 chimeric ribozyme, could more efficiently express and downregulate the level of caspase-3 in vivo, and the ribozyme could provide an alternative approach to the research into the mechanism of apoptosis and human gene therapy also.

Exon structure requirements for yeast tRNA ligase

Different nucleotides were introduced into nucleotides 32, 37 and 38 of yeast tRNA(Phe) precursors via oligonucleotide directed mutations. Pre-tRNAs were prepared using T7-transcription in vitro and spliced with the purified yeast tRNA endonuclease and tRNA ligase. It is demonstrated that tRNA ligase activities will be inhibited by the 5'-double-stranded end of 3'-halves.

CYP11A1 Is a Predictor of Mammographic Breast Density

Mammographic density (MD) is a strong predictor of breast cancer risk and is highly correlated with the hormone exposure profiles of women. It is also a highly heritable risk factor (heritable component ∼67%). As such, many efforts have been made to identify underlying genetic determinants of MD within pathways related to steroid hormone biosynthesis and metabolism. Several associations with genetic polymorphisms in genes involved in estrogen metabolism have been previously described (e.g. COMT and HSD3B1). Still, there is controversy among the conclusions of these studies. In addition, only a few candidate genes have been interrogated at a time. In this study, we assess associations of genetic variants with MD using the most extensive estrogen metabolic pathway coverage to date.Materials and methods:Cases were 891 Swedish-born women who were 50-74 years of age at diagnosis and diagnosed with breast cancer between October 1993 and March 1995. 840 controls were population and frequency matched to the expected age distribution of the cases.MD was measured using a computer-assisted technique (Cumulus, University of Toronto, Canada) and evaluated by comparing the dense area by the total breast area.Genotyping was performed on a total of 239 SNPs in 34 estrogen metabolic genes using the Sequenom (San Diego, California) primer extension-based assay. SNPs with a call rate &lt;85%, minor allele frequency &lt;1% or out of Hardy-Weinberg Equilibrium (p&lt;0.05/239) were excluded from further analysis.The Cochran-Armitage trend test was carried out for all SNPs with adjustments for age, body mass index, menopausal status and hormone replacement therapy usage.Results:We report a novel association finding between MD and the gene CYP11A1. 5 out of 6 SNPs within the gene were found to be significant after adjustment. The average increase in MD attributed to these SNPs is 5.4%. Other genes with significant associations include HSD17B3, STS, and NQO1.Discussion:A high level of endogenous estrogen is well-known to be correlated with an increased risk of breast cancer. CYP11A1 encodes a member of the cytochrome P450 superfamily of enzymes and is of interest as it represents is the first as well as a rate-limiting step in steroid hormone biosynthesis.In addition, a role for CYP11A1 in the metabolism of vitamin D3 has been reported recently. High vitamin D levels have been associated with a decrease in both breast cancer risk and MD. Although the active compound most commonly implicated is 1,25-dihydroxyvitamin D3 derived from a more extensively studied pathway, new studies have shown that a by-product of CYP11A1 exhibits similar functions in the regulation of cell proliferation and differentiation.Although CYP11A1 has been previously reported to be associated with breast cancer, it has never been studied in relation to MD. This novel finding suggests that CYP11A1 exerts an influence on MD through two different pathways linked to breast cancer and affirms MD as an intermediate phenotype for the disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5161.

Cerebrospinal Fluid Cytology and Clinical Analysis of 34 Cases with Leptomeningeal Carcinomatosis

The clinical characteristics and cerebrospinal fluid (CSF) cytological features of 34 hospitalized patients with leptomeningeal carcinomatosis (LC) were studied. Most patients presented with signs of meningeal irritation (19 cases) and intra-cranial hypertension (23 cases). Computed tomography (CT) and/or magnetic resonance imaging (MRI) revealed brain parenchymal lesions, hydrocephalus and leptomeningeal enhancement (nine, six and eight cases, respectively). The CSF changes included high opening pressure (21 cases), increased white blood cell count (23 cases), elevated protein levels (25 cases) and low glucose levels (17 cases). Malignant cells were found in all CSF specimens and 32 cases had malignant cells in their initial CSF examinations. High serum levels of carcinoembryonic antigen (CEA) occurred in 11 patients. Signs of meningeal irritation and intra-cranial hypertension were common. It is concluded that serum CEA measurement along with CT and MRI scanning are helpful in the diagnosis of LC. Crucially, however, CSF cytology could be the most important technique for the diagnosis of LC.

Electron attachment and electron ionization of acetic acid clusters embedded in helium nanodroplets

The effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic products ejected into the gas phase are detected by mass spectrometry. The cation chemistry (induced by electron ionization at 100 eV) is dominated by production of protonated acetic acid (Ac) clusters, Ac(n)H(+), although some fragmentation is also observed. In the case of anion production (at 2.8 eV electron energy) there is a clear distinction between the monomer and the clusters. For the monomer the dominant product is the dehydrogenated species, [Ac-H](-), whereas for the clusters both the parent anion, Ac(n)(-), and the dehydrogenated species, [Ac(n)-H](-), have similar abundances. A particularly intriguing contrast between the monomer and cluster anions is that helium atoms are seen attached to the latter whereas no evidence of helium atom attachment is found for the monomer. This surprising observation is attributed to the formation of acyclic (head-to-tail) acetic acid clusters in helium nanodroplets, which have more favourable electronic properties for binding helium atoms. The acyclic clusters represent a local minimum on the potential energy surface and in the case of the dimer this is distinct from the cyclic isomer (the global minimum) identified in gas phase experiments.

Genome sequence, comparative analysis, and population genetics of the domestic horse

We report a high-quality draft sequence of the genome of the horse (Equus caballus). The genome is relatively repetitive but has little segmental duplication. Chromosomes appear to have undergone few historical rearrangements: 53% of equine chromosomes show conserved synteny to a single human chromosome. Equine chromosome 11 is shown to have an evolutionary new centromere devoid of centromeric satellite DNA, suggesting that centromeric function may arise before satellite repeat accumulation. Linkage disequilibrium, showing the influences of early domestication of large herds of female horses, is intermediate in length between dog and human, and there is long-range haplotype sharing among breeds.

Hepatitis B virus protein preS2 potentially promotes HCC development via its transcriptional activation of hTERT

BACKGROUNDS AND AIMS

Telomerase is significantly reactivated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). Our previous studies showed that the transactivation unit of HBV surface (S) gene, preS2, could upregulate human telomerase reverse transcriptase (hTERT) expression and telomerase activity of HepG2 cells. Here, we aim to explore the functions, and the underlying mechanisms, of this preS2-mediated hTERT upregulation during HCC development.

METHODS

An antisense blocking assay was performed on HBV-integrated HepG2.2.15 cells. The expression of hTERT was examined in clinical samples to test the role of the preS2-mediated hTERT upregulation in HCC development in vivo. In order to explore the mechanisms of preS2-mediated hTERT upregulation, co-transfection, reporter assays and electrophoretic mobility shift assays (EMSA) were performed.

RESULTS

Blocking preS2 expression reduced hTERT expression, telomerase activity, cell proliferation and tumorigenicity of HepG2.2.15. A region located between -349 and -329 bp upstream of the transcription initiation site of hTERT was identified as responsible for the preS2-mediated effect. preS2 interacted with the preS2-responsible region (PRR) and activated the hTERT promoter. Importantly, hTERT was also highly expressed in preS2-positive human HCC samples. All these findings strongly suggest that preS2 may promote HCC development via hTERT activation.

CONCLUSIONS

HBV protein preS2 upregulates hTERT via the PRR element in promoting HCC development.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

Use of short echo time two-dimensional 1H-magnetic resonance spectroscopy in temporal lobe epilepsy with negative magnetic resonance imaging findings

We evaluated short echo time two-dimensional 1H magnetic resonance spectroscopy (2D-1HMRS) with the point-resolved spatial selection (PRESS) protocol in temporal lobe epilepsy (TLE) patients with negative magnetic resonance imaging (MRI) findings and described the characteristics of 2D-(1)HMRS in the epileptic focus. Thirty-eight TLE patients with negative conventional MRI findings and 10 healthy controls were studied by 2D-1HMRS. A 128-channel prolonged video-electroencephalographic (EEG) method was used as the standard for epileptogenic focus localization to evaluate N-acetyl aspartate/(choline + creatine + phosphocreatine) (NAA/[Cho + Cr-PCr]), glutamate + glutamine/creatine (Glx/Cr-PCr) and myo-inositol/Cr-PCr ratios in patients with negative MRI findings. The 2D-1HMRS showed that 32/38 patients and all healthy controls had stable baselines and good signal-to-noise ratios. Compared with the healthy controls, 32 patients showed abnormal NAA/(Cho + Cr-PCr) ratios in the hippocampus and, in 25 of these patients, focus lateralization agreed with the EEG. It is concluded that short echo time 2D-1HMRS with the PRESS protocol can help find abnormalities in lateralization of temporal epilepsy in patients with negative MRI findings.

The relationship between Chinese construction workers' HIV/AIDS-related knowledge, attitudes and behaviour: a structural equation model

This study explored the relationship between human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS)-related knowledge, attitudes and behaviour in migrant urban construction workers using structural equation modelling (SEM). A cross-sectional study was conducted among 428 male subjects on three building sites in Shenyang City. The SEM model of HIV/AIDS-related knowledge, attitudes and behaviour was built using LISREL version 8.5 and it fitted the data well, as shown by an adjusted goodness of fit index of 0.82 and a root mean square error of approximation of 0.094. Knowledge of HIV/AIDS was closely correlated with attitudes and behaviour. Age was an important factor affecting HIV/AIDS-related knowledge, attitudes and behaviour. These findings suggest that increasing HIV/AIDS-related knowledge could improve the attitude and behaviour of migrant urban construction workers, enabling them to avoid high-risk behaviour that increases the spread of HIV/AIDS. Any intervention used will need to take the important factor of age into consideration.