Comparison of nutritional quality between Chinese indica rice with sck and cry1Ac genes and its nontransgenic counterpart

Nutritional assessment of transgenic crops used for human food and animal feed is an important aspect of safety evaluations. An insect-resistant rice (IRR) was generated by the stable insertion of sck, a modified cowpea trypsin inhibitor gene, and cry1Ac, encoding a crystal protein from Bacillus thuringiensis into the genome of a common variety of Chinese indica rice. The composition of the brown and milled rice grain from the resulted IRR line designated Liangyou Kefeng No. 6 was compared with that of the parental rice cultivar Liangyou 2186. Nutrients, including the proximates, amino acids, fatty acids, minerals, and vitamins, were measured. The antinutritive components such as phytic acid, lectin, and trypsin inhibitors were also examined. The data demonstrated that the nutritional quality of both the brown and milled rice grains from the transgenic line was substantially equivalent to that of the nontransgenic counterpart, and measured amounts of nutritional components fell within the range of values reported for other commercial lines.

Clinical studies of hemodialysis access through formaldehyde-fixed arterial allografts

Efficient hemodialysis requires establishing a permanent stable vascular access. Our study was designed to evaluate formaldehyde-fixed arterial allografts as hemodialysis access for end-stage renal disease. Various parameters were determined for 68 formaldehyde-fixed, cadaver-derived allografts transplanted into 43 hemodialysis patients. The sources of the allografts were determined to be free of cytomegalovirus, hepatitis B and hepatitis C, and HIV infections. These allografts were monitored for rejection, blood flow, patency rates, and complications. Overall, antigenicity of the allografts was reduced after formaldehyde fixation with no acute rejection. The mean access blood flow was 696+/-282 ml with reasonable primary and secondary patency rates even after 3 years. Allograft intimal hyperplasia, determined by immunohistochemistry, was evident as the proliferation of smooth muscle-like cells expressing actin but cells not expressing the endothelial markers von Willebrand factor or CD34. The incidence of thrombus formation was about 37% after allograft transplant with other limited complications of pseudoaneurysms and local infection. Our results support the clinical use of formaldehyde-fixed arterial allografts for hemodialysis access.

Noise pre-filtering techniques in fluorescence-enhanced optical tomography

In this contribution, different measurement noise pre-filtering techniques were developed using frequency-domain fluorescence measurements of homogeneous breast phantoms. We demonstrated that implementing noise pre-filtering, based on modulation depth and measurement error in amplitude, can improve model match between experimental and simulated data under varying experimental conditions (target depths, 1-3 cm and fluorescence optical contrast, 1:0 and 100:1). Noise pre-filtering also improves the qualitative estimation of target(s) location in reconstructed images in deep target(s) when there was fluorescence in the background. Interestingly, decreases in model mismatch did not necessarily correlate with increases in reconstructed target accuracy. In addition, it was observed that pre-filtering measurement noise using different criteria can help differentiate target(s) from artifacts, thus possibly minimizing the false-positive cases in a clinical environment.

Inhibition of tumorigenesis by intratumoral delivery of the circadian gene mPer2 in C57BL/6 mice

Biological clocks are intrinsic time-keeping systems that regulate behavior and physiological functions in most living organisms. Previous works suggested a possible link between the endogenous circadian clock and cell cycle regulation. The mammalian Period-2 gene (mPer2), an important component of the circadian clock mechanism, is recently demonstrated to play an important role in repressing tumor growth. In this study, we found that polyethylenimine-mediated intratumoral Per2 gene delivery had significant antitumor effects in C57BL/6 mice transplanted with Lewis lung carcinoma. Our data illustrated that the Per2 gene delivery inhibited PCNA expression and induced apoptosis. Our results support the emerging role of the circadian clock in critical aspects of tumorigenesis. These findings underscore the potential use of Per2 gene delivery as a novel therapeutic intervention for the treatment of malignant tumors.

Comparative proteomic analysis for the detection of biomarkers in pancreatic ductal adenocarcinomas

AIMS

To search for novel potential protein biomarkers for the early detection and better intervention of pancreatic ductal adenocarcinoma (PDAC).

METHODS

Eight pairs of matched PDAC and non-cancerous pancreas tissues were profiled with two-dimensional electrophoresis; differentially expressed proteins were identified by mass spectrometry. Expression patterns of TBX4 (T-box transcription factor TBX4) and HSP60 (60 KDa heat shock protein) were studied with immunohistochemistry using tissue microarrays.

RESULTS

A total of 48 differentially expressed proteins were identified; 30 of them are novel potential biomarkers. Immunohistochemistry showed that TBX4 expression could be seen in both centroacinar cells and small ducts in normal pancreas and tumour cells in 5/5 (100%) well differentiated, 35/38 (92.1%) moderately differentiated, and 11/18 (61.1%) poorly differentiated PDAC tissues with different staining intensity. However, in normal acinar cells and tumour cells in the other 3/38 (7.9%) moderately differentiated and 7/18 (38.9%) poorly differentiated PDAC tissues, there was no visible TBX4 expression. The expression difference of TBX4 between moderately differentiated and poorly differentiated PDAC tissues was statistically significant (p<0.01). In addition, there was obvious morphology difference between TBX4 negatively stained and positively stained tumour cells, which suggests different cellular origins. Strong expression of HSP60 could be seen in both acinar cells and small ducts in normal pancreas tissues and tumour cells in PDAC tissues except for islets and tumour stoma; no correlation was found between HSP60 expression and differentiation of PDAC tissues.

CONCLUSIONS

30 novel potential biomarkers differentially expressed in PDAC tissues were identified. TBX4 may be a differentiation related protein; its prognostic value for PDAC deserves further study.

Identification of a diagnostic antibody-binding region on the immunogenic protein EpC1 from Echinococcus granulosus and its application in population screening for cystic echinococcosis

An Echinococcus granulosus cDNA sequence coding for EpC1, a proven serodiagnostic marker for cystic echinococcosis (CE, hydatid disease), has high amino acid sequence identity to a paralogue from Taenia solium, the cause of neurocysticercosis (NCC). To determine diagnostic antibody-binding regions on EpC1 recognized specifically by CE sera, 10 truncated regions (P1-10) of the immunogenic protein were expressed in Escherichia coli and subjected to immunoblotting. One peptide, designated peptide 5 [P5, fused with glutathione-S-transferase (GST)] was positively recognized by sera from mice experimentally infected with oncospheres of E. granulosus and sera from surgically confirmed CE patients. Sera from NCC patients did not react with any of the peptides used. There are four amino acid substitutions in P5 compared with the T. solium sequence and these may form part of the epitope inducing CE-specific antibody. Ninety-seven per cent (58 of 60) of sera from confirmed CE patients recognized P5-GST, which was higher than the parent EpC1 fused with GST which reacted with 92% (55 of 60) of the sera. A population screening survey showed that 424 human sera collected from communities in Xinjiang, an area in China endemic for CE, exhibited 4.5% and 3.3% positivity in immunoblotting analysis to EpC1 and P5, respectively; 19.8% of these sera reacted positively against hydatid cyst fluid (HCF) antigen B. Low numbers of surgical CE cases have been reported from this population, suggesting that HCF-based serology lacks specificity and that EpC1 or its contained P5 peptide may prove more accurate for seroepidemiological surveys of CE.

Nanocrystalline silicon-based oligonucleotide chips

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).

Chimaeric Protein Improved Immunogenicity Compared with Fusion Protein of Ag85B and ESAT-6 Antigens of Mycobacterium tuberculosis

Antigen 85B (Ag85B) and ESAT-6 are important immunodominant antigens of Mycobacterium tuberculosis, and both are very promising vaccine candidate molecules. In this study, we relied on the T-cell epitopes of Ag85B and ESAT-6 to design a chimaeric protein by inserting ESAT-6 into Ag85B from the amino acids 167-182. We found the ratio of IgG2b/IgG1 and the secretion of interferon (IFN)-gamma in the mice vaccinated with the new protein with adjuvant MPL and TDM were higher than the mice immunized with fusion protein Ag85B-ESAT-6, which have been reported and could induce levels of protective immunity similar to BCG in the mouse model of tuberculosis (TB) infection. These results suggest that the chimaeric protein Ag85B(N)-ESAT-6-Ag85B(C) is a strong candidate for further study and the T-cell epitopes of the antigens should be considered when we design the subunit vaccine.

Minimal ProtoHox cluster inferred from bilaterian and cnidarian Hox complements

Bilaterian animals have a Hox gene cluster essential for patterning the main body axis, and a ParaHox gene cluster. Comparison of Hox and ParaHox genes has led workers to postulate that both clusters originated from the duplication of an ancient cluster named ProtoHox, which contained up to four genes with at least the precursors of anterior and posterior Hox/ParaHox genes. However, the way in which genes diversified within the ProtoHox, Hox and ParaHox clusters remains unclear because no systematic study of non-bilaterian animals exists. Here we characterize the full Hox/ParaHox gene complements and genomic organization in two cnidarian species (Nematostella vectensis and Hydra magnipapillata), and suggest a ProtoHox cluster simpler than originally thought on the basis of three arguments. First, both species possess bilaterian-like anterior Hox genes, but their non-anterior genes do not appear as counterparts of either bilaterian central or posterior genes; second, two clustered ParaHox genes, Gsx and a gene related to Xlox and Cdx, are found in Nematostella vectensis; and third, we do not find clear phylogenetic support for a common origin of bilaterian Cdx and posterior genes, which might therefore have appeared after the ProtoHox cluster duplication. Consequently, the ProtoHox cluster might have consisted of only two anterior genes. Non-anterior genes could have appeared independently in the Hox and ParaHox clusters, possibly after the separation of bilaterians and cnidarians.

Construction of a medium-density horse gene map

A medium-density map of the horse genome (Equus caballus) was constructed using genes evenly distributed over the human genome. Three hundred and twenty-three exonic primer pairs were used to screen the INRA and the CHORI-241 equine BAC libraries by polymerase chain reaction and by filter hybridization respectively. Two hundred and thirty-seven BACs containing equine gene orthologues, confirmed by sequencing, were isolated. The BACs were localized to horse chromosomes by fluorescent in situ hybridization (FISH). Overall, 165 genes were assigned to the equine genomic map by radiation hybrid (RH) (using an equine RH(5000) panel) and/or by FISH mapping. A comparison of localizations of 713 genes mapped on the horse genome and on the human genome revealed 59 homologous segments and 131 conserved segments. Two of these homologies (ECA27/HSA8 and ECA12p/HSA11p) had not been previously identified. An enhanced resolution of conserved and rearranged chromosomal segments presented in this study provides clarification of chromosome evolution history.

In silico comparison of gene expression levels in ten human tumor types reveals candidate genes associated with carcinogenesis

Most human cancers are characterized by genomic instability. Changes associated with such may result in altered expression of numerous genes. The sequence information available in the public databases can be used to identify transcripts differentially expressed in cancers. Determining cancer-related genes that are commonly deregulated in different tumor types may facilitate identification of targets for cancer diagnoses and therapeutic treatments. Using a data-mining tool named Digital Differential Display (DDD) from the UniGene database at the NCBI web site, gene expression levels of ten different tumor types and their counterpart normal tissues were analyzed. Unigenes which showed transcriptional regulation in more than five tumor types with > or =2-fold differences from normal tissues were identified. The expression data of selected Unigenes were subjected to clustering analysis. 127 commonly up-regulated genes and 92 commonly down-regulated genes were identified. Clustering analysis using these genes showed that most tumor types can be clustered into a separate branch from most normal tissues. Nineteen genes that have been shown to be involved in carcinogenesis by experimental evidence were also identified. Present computational analyses revealed 219 candidate cancer-related genes that are commonly deregulated in ten human tumor types which may contribute to the progress of carcinogenesis.

The effect of paternal heat stress on protein profiles of pre-implantation embryos in the mouse

The study was undertaken to compare the protein profiles of [35S]-methionine-labelled control-sired embryos with heat-sired embryos at 7, 14 or 21 days after mature fertile B6CBF F1 male mice were kept at 36 +/- 0.3 degrees C and 62 +/- 2.7% relative humidity for 24 h. One-dimensional gel electrophoresis and autoradiographs were used to examine the protein profiles between the two-cell embryos and the blastocysts. The results obtained demonstrate that paternal heat stress 7 or 14 days earlier did not apparently affect protein patterns of two-cell embryos, four-cell to eight-cell embryos, morulae or blastocysts. However, 21 days earlier, there were changes in protein patterns of two-cell embryos and abnormal embryos, but not the morulae. To further support and extend these results, two-dimensional gel electrophoresis and phosphorimaging were employed and the results obtained show that paternal heat stress 21 days before mating affected protein profiles of two-cell embryos and morulae in the mouse. Together, these findings have indicated that paternal heat stress affects most but not all protein patterns of pre-implantation embryos, which strongly supports our previous results demonstrating that paternal heat stress significantly reduced the developmental proportion of pre-implantation embryos in the mouse.

Single nucleotide polymorphisms and haplotypes of histamine N-methyltransferase in patients with gastric ulcer

INTRODUCTION

Histamine plays a crucial role in the regulation of gastric acid secretion, which is involved in the pathogenesis of peptic ulcer. Histamine N-methyltransferase (HNMT) is the major metabolizing enzyme for histamine inactivation in human stomach.

OBJECTIVE

This study aims to determine whether there exists a relationship between HNMT gene polymorphisms and the risk for gastric ulcer (GU).

METHODS

118 GU patients and 154 ethnically matched control subjects were enrolled and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays were developed to genotype all these subjects for the T-1637C, C-411T, C314T and A1097T point mutations in HNMT gene. Haplotypes were reconstructed from the genotype data.

RESULTS

Frequencies of the variant alleles in cases and controls were 0.398 vs 0.396 for T-1637C, 0.144 vs 0.110 for C-411T, 0.034 vs 0.042 for C314T, and 0.242 vs 0.273 for A1097T, respectively, with no significant difference for any locus between the two groups (all P > 0.05). Also the frequencies of genotypes, haplotypes and haplotype pairs based on these polymorphisms did not differ significantly between cases and controls.

CONCLUSION

This study provided no evidence for the involvement of HNMT polymorphisms in the susceptibility to GU.

Effect of paternal heat stress on the development in vitro of preimplantation embryos in the mouse

This study was conducted to investigate the effects of paternal heat stress on the development in vitro of preimplantation embryos in the mouse. Female C57/CBA mice were superovulated using eCG/hCG and mated either to an untreated (control) male mouse or to one that had been exposed for 24 h to an ambient temperature of 36 +/- 0.1 degrees C and 62 +/- 0.4% relative humidity, between 3 and 42 days previously. Putative zygotes were collected from the oviducts of mated mice, 25-28 h after hCG injection, and cultured in vitro. Embryo development was evaluated at 24-h intervals for up to 120 h. Paternal heat stress significantly reduced the proportion of embryos that developed normally during 24-120 h of in vitro culture, when zygotes were sired by males which had been heat stressed between 7 and 35 days prior to mating. Maximum impairment to development (including nondevelopment, abnormal and dying/dead embryos) occurred in those embryos sired by males at days 14 and 21 after heating. Embryo development returned to control levels by day 42 after heat stress. Furthermore, whilst all stages of embryo development were affected by paternal heat stress, the proportion of embryos at the two-cell stage appeared to be most severely affected. Four-cell to morula stages and the morula to blastocyst stage also demonstrated impairment at days 14, 21, 28 and 35 after heating. These results demonstrate that a single episode of paternal heat stress significantly reduces the development of preimplantation embryos, and this is not recovered until day 42 after heating. The present results also support previous work demonstrating that sperm from the epididymis as well as germ cells in the testis are susceptible to damage by heat stress, with both spermatids and spermatocytes being the most vulnerable.