Improved precision with Hologic Apex software

The precision of Hologic Apex v2.0 analysis software is significantly improved from Hologic Delphi v11.2 software and is comparable to GE Lunar Prodigy v7.5 software. Apex and Delphi precisions were, respectively, 1.0% vs. 1.2% (L1-L4 spine), 1.l % vs. 1.3% (total femur), 1.6% vs. 1.9% (femoral neck), and 0.7% vs. 0.9% (dual total femur).

INTRODUCTION

Precision of bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry (DXA) is known to vary by manufacturer, model, and technologist. This study evaluated the precision of three analysis versions: Apex v2.0 and Delphi v11.2 (Hologic, Inc.), and Prodigy v7.5 (GE Healthcare, Inc.) independent of technologist skill.

METHODS

Duplicate spine and dual hip scans on 90 women were acquired on both Delphi and Prodigy DXA systems at three clinics. BMD measures were converted to standardized BMD (sBMD) units. Precision errors were described as a root-mean-square (RMS) standard deviations and RMS percent coefficients of variation across the population.

RESULTS

Apex and Delphi values were highly correlated (r ranged from 0.90 to 0.99). Excluding the right neck, the Apex precision error was found to be 20% to 25% lower than the Delphi (spine: 1.0% versus 1.2% (p < 0.05), total hip: 1.1% versus 1.3% (p < 0.05), right neck: 2.3% versus 2.6% (p > 0.1)). No statistically significant differences were found in the precision error of the Apex and Prodigy (p > 0.05) except for the right neck (2.3% versus 1.8% respectively, p = 0.03).

CONCLUSION

The Apex software has significantly lower precision error compared to Delphi software with similar mean values, and similar precision to that of the Prodigy.

Molecular characterization, expression and association analysis of the porcine CMYA4 gene with carcass traits

CMYA4 (cardiomyopathy-associated 4) gene plays an important role in thick filament assembly. In this study, we obtained the mRNA sequence including the full coding sequence and the partial 5' untranslated region of the porcine CMYA4 gene by using the rapid amplification of cDNA ends and reverse transcriptase polymerase chain reaction (RT-PCR) and the sequence was deposited in the GenBank nucleotide database (DQ_286571). The human (NM_173167) and mouse (NM_178680) homologues have a 91% and 87% identity with the porcine CMYA4 gene, respectively. The sequence contains an open reading frame encoding 930 amino acid residues, and the amino terminus of the predicted CMYA4 protein contains three tandem repeats belonging to the tetratricopeptide repeat family. Semi-quantitative RT-PCR results showed that the porcine CMYA4 gene is expressed exclusively in striated muscle tissue. An A558G single nucleotide polymorphism in the CMYA4 intron 15 detected as an MspI PCR-restriction fragment length polymorphism showed allele frequency differences among 225 unrelated pigs from six breeds. Association of the genotypes with growth and carcass traits showed that different genotypes of the CMYA4 gene were significantly associated with the backfat thickness of the area between sixth and seventh ribs (p < 0.05) and backfat thickness at the shoulder (p < 0.05).

Creation of nanostructures with poly(methyl methacrylate)-mediated nanotransfer printing

We demonstrate here a PMMA-mediated nanotransfer printing technique for reliably transferring nanoscale building blocks and sequentially building purpose-directed nanostructures. The utilization of PMMA film as a mediator introduced several features to this transfer approach, such as high efficiency, fidelity, universality, controllability, and multilevel transferability. Various nanostructures, such as an SWNTs-on-SAM structure, high-density crossbar array of SWNTs, a hybrid n-ZnO nanowire/p-SWNT cross-junction, a gold nanostructure-SAM-gold sandwich structure, a zigzag array of SWNTs, and gold nanobowl array were generated with this transfer approach. A metallic-semiconducting SWNT cross circuit was built to demonstrate its potential application in fabricating nanoelectronic devices. This technique paves the way to generate various structures with homo- or heterogeneous nanoscale building blocks, which facilitates exploring their fundamental properties and building novel devices.

Molecular characterization and expression pattern of the porcine STARS, a striated muscle-specific expressed gene

STARS (striated muscle activator of Rho signaling) promotes the nuclear localization of MRTFs and mediates SRF transcription, which provides a potential muscle-specific mechanism for linking changes in the actin cytoskeleton structure with muscle gene expression. In this study, the full-length cDNA of the porcine STARS was cloned. The open reading frame of this gene contains 1,155 bp and encodes a protein of 384 amino acids, which is 79, 73, and 77% identical with human, mouse, and rat STARS genes, respectively. RT-PCR revealed that STARS is specifically expressed in heart and skeletal muscles. STARS is also distinctly different in different muscle developmental stages. The result indicates that its expression increased gradually from 33 dpc (days postcoitum) to postnatal muscles, and peaked 28 days postnatal. The porcine STARS was mapped to SSC4p13 using the somatic cell hybrid panel and the radiation hybrid panel IMpRH (LOD score 11.98). The data show that STARS is closely linked to marker SW871. A T/G single nucleotide polymorphism in the coding sequence, detected as Bsh1236I PCR-RFLP, displays allele frequency differences in six pig breeds.

Investigation of Lpin1 as a candidate gene for fat deposition in pigs

Lpin1 deficiency prevents normal adipose tissue development and remarkably reduces adipose tissue mass, while overexpression of the Lpin1 gene in either skeletal muscle or adipose tissue promotes adiposity in mice. However, little is known about the porcine Lpin1 gene. In the present study, a 5,559-bp cDNA sequence of the porcine Lpin1 gene was obtained by RT-PCR and 3'RACE. The sequence consisted of a 111-bp 5'UTR, a 2,685-bp open reading frame encoding a protein of 894 amino acids and a 2,763-bp 3'UTR. Semi-quantitative RT-PCR analysis revealed that Lpin1 had a high level of expression in the liver, spleen, skeletal muscle and fat, a low level of expression in the heart, lung and kidney. The porcine Lpin1 gene was assigned to 3q21-27 by using the somatic cell hybrid panel (SCHP) and the radiation hybrid (IMpRH) panel. One C93T single nucleotide polymorphism (SNP) was identified and genotyped using the TaqI PCR-RFLP method. Association analysis between the genotypes and fat deposition traits suggested that different genotypes of the Lpin1 gene were associated with percentage of leaf fat and intramuscular fat.

Assignment of solute carrier family 2 (facilitated glucose transporter), members <i>SLC2A2</i>, <i>SLC2A3</i>, <i>SLC2A5</i>, <i>SLC2A8</i> and <i>SLC2A12</i> to porcine chromosomes by somatic cell and radiation hybrid panel mapping (Brief report)

Abstract. The transport of glucose plays an important role in cellular glucose homeostasis and metabolism [1]. Due to the hydrophilic character of glucose, the transport of glucose in and out of cells requires specific carrier proteins. The mammalian facilitative glucose transport family, which contains the energy-independent transporters (gene symbol SLC2A, protein symbol GLUT), catalyzes the entry of glucose into mammalian cells by facilitative diffusion down a concentration gradient. Thirteen members of mammalian GLUT family have been now characterized [1]. In swine, the chromosomal locations for the five genes (SLC2A2, SLC2A3, SLC2A5, SLC2A8 and SLC2A12) have not yet been determined. In this study, as the first step to better understand of the roles of these GLUTs in pigs which could subsequently be beneficial for pig production, we report the mapping of the five genes using both porcine somatic cell hybrid panel (INRA-SCHP) and radiation hybrid panel (IMpRH).

Morphometric study of the apical anatomy of C-shaped root canal systems in mandibular second molars

AIM

To investigate the apical anatomy of C-shaped canal systems in mandibular second molars by micro-computerized tomography (microCT) and stereomicroscopy.

METHODOLOGY

Forty-four permanent mandibular second molars with a C-shaped root canal systems from a native Chinese population were scanned at 100 microm intervals by microCT at a resolution of 30 x 30 microm. The apical 5 mm of each tooth was reconstructed three-dimensionally for visualization and classification of the canal configuration using Vertucci's criteria. The main and auxiliary (accessory) foramina were examined under a stereomicroscope.

RESULTS

Type IV and VIII canal configurations were most often found in the apical 5 mm of these canal systems. The prevalence of accessory canals, lateral canals, inter-canal communications and apical delta were 41%, 25%, 27% and 11%, respectively. Approximately 80% of C-shaped canals had 1-3 apical foramina; the prevalence of accessory foramina was about 48%. The mean distance between the main foramen and the anatomic root apex was 0.84 mm, and that between the accessory foramen and the apex was 1.61 mm. The mean (shortest and longest) diameters of major and accessory foramina were 0.19 - 0.32 mm and 0.07 - 0.10 mm, with a mean form factor of 0.73 and 0.82, respectively.

CONCLUSION

The apical anatomy of C-shaped root canal systems in mandibular second molars is extremely complex with many anatomical variations.

Immunogenicity and persistence of a targeted anti-caries DNA vaccine

We have previously reported that a targeted anti-caries DNA vaccine, pGJA-P, induced accelerated and increased antibody responses compared with a non-targeted anti-caries DNA vaccine. Recently, pGJA-P/VAX, a new targeted anti-caries DNA vaccine for human trials, was constructed by replacing the pCI vector used in the construction of pGJA-P with pVAX1, the only vector authorized by the US Food and Drug Administration in clinical trials. Here, we report on our exploration of the kinetics of the antibody responses generated following pGJA-P/VAX immunization and the persistence of pGJA-P/VAX at both the inoculation site and the draining lymph nodes. Intranasal vaccination of mice with pGJA-P/VAX induced strong antibody responses that lasted for more than 6 months. Furthermore, pGJA-P/VAX could still be detected at both the inoculation site and the draining cervical lymph nodes 6 months after immunization. Thus, the persistent immune responses are likely due to the DNA depot in the host, which acts as a booster immunization.

Expression and bioactivity of recombinant human lysozyme in the milk of transgenic mice

Human milk lysozyme is an important protein for innate immunity, but human breast milk is a fairly poor source for commercial production of this enzyme. Research on the expression of recombinant human lysozyme (rHlys) is therefore potentially valuable to the dairy industry. In this study, 2 different kinds of transgenic mice, PBC-hLY and PBC-sighLY, were generated and used as system models to express rHlys. Six lines of PBC-hLY transgenic mice with human lysozyme genomic DNA-based constructs were generated, and a maximum expression level of rHlys approaching 0.154 mg/mL was achieved. Antibacterial activity of the whey from PBC-hLY female transgenic mice was determined by a turbidimetric assay. Results showed that antibacterial activity of the whey was strongly enhanced, and confirmed that rHlys retained full activity. For rHlys to be secreted efficiently into the milk of transgenic mice, 5 lines of mice were also generated, in which the signal peptide DNA of bovine beta-casein was substituted for that of lysozyme in PBC-hLY transgenic mice. Compared with PBC-hLY transgenic mice, both the expression levels of rHlys and the antibacterial activity of the whey were much higher in the PBC-sighLY transgenic mice. The concentration of rHlys in one of these mice amounted to 1.405 mg/mL-3 times higher than the level in human whey. The antibacterial activity of the whey was also 3 times higher than that of human whey. The rHlys from both PBC-hLY and PBC-sighLY transgenic mice had the same antibacterial activity as human milk lysozyme. The effect of the signal peptide and copy numbers of the transgene on expression of rHlys was also evaluated. This work will certainly permit a better understanding of how mammary gland bioreactor systems can be applied to produce rHlys in other mammals, such as cattle.

Partial molecular characterization, polymorphism and chromosomal localization of the porcine PSMD4 gene

The complete coding sequence of porcine PSMD4 gene encoding proteasome 26S non-ATPase subunit 4 was obtained by the reverse transcriptase-polymerase chain reaction (RT-PCR) and deposited in GenBank nucleotide database (AY704418). The nucleotide sequence and the predicted protein sequence shared the high sequence identity with their mammalian counterparts. A G/A single nucleotide polymorphism in intron 9 detected as Hin6I PCR-restriction fragment length polymorphism (PCR-RFLP) shows allele frequency differences between Meishan, Erhualian, Tibetan, Large White and Duroc breeds. Analyses of somatic cell hybrid panel (SCHP) and radiation hybrid (IMpRH) panel revealed that PSMD4 gene maps to SSC 4q21-q23 and closely linked the SW512 (14 cR, LOD = 19.47).

Cooperative antitumor activity between the retinoid X receptor (RXR)-selective agonist bexarotene and EGFR-tyrosine kinase inhibitors in preclinical models of NSCLC

17073

Background: Gefitinib and erlotinib, small molecule inhibitors of the EGFR-tyrosine kinase (EGFR-TKI), can have antitumor activity in patients with advanced NSCLC. However, analysis of clinical samples and in vitro characterization of NSCLC cell lines has revealed EGFR mutations that correlate with the clinical responses. While EGFR-mutant cell lines are hypersensitive to EGFR-TKI-mediated growth inhibition and have a greater tendency to undergo apoptosis in response to EGFR inhibition, wild-type EGFR cell lines undergo growth inhibition only at high concentrations, and are resistant to apoptosis induction. Bexarotene (Targretin) is a RXR modulator with clinical activity enhancing survival in a subset of NSCLC patients. We have shown that bexarotene can suppress the growth of epithelial tumors by modulating the expression and function of the EGFR pathway. This study examined the effect of bexarotene/EGFR-TKI combinations in preclinical models of NSCLC, and evaluated the possible molecular mechanisms for cooperative antitumor activity between these agents. Results: Bexarotene enhanced the activity of gefitinib in most of the cell lines tested, and did so regardless of their EGFR mutation status or intrinsic sensitivity to gefitinib alone. Resistant lines were sensitized by the combination, which decreased gefitinib IC50s to clinically achievable concentrations. Bexarotene increased the pro-apoptotic activity of both gefitinib and erlotinib, an effect which was paralleled by enhanced repression of p-Akt and p-Her2 levels by the combinations. In ex vivo cultures of human NSCLC explant tissue, the addition of bexarotene enhanced the growth inhibitory activity of both gefitinib and erlotinib. Finally, combinations of bexarotene and EGFR-TKI produced growth inhibition of TKI-resistant A427 NSCLC xenograft tumors that was superior to either agent alone. Conclusions: These results indicate that bexarotene can sensitize NSCLC cells which are unresponsive to the effects of EGFR-TKIs, resulting in cooperative growth inhibition and apoptosis induction. Combination therapy using bexarotene in conjunction with EGFR-TKIs may provide a powerful new therapeutic strategy.

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