Potential metabolite markers of schizophrenia

Schizophrenia is a severe mental disorder that affects 0.5-1% of the population worldwide. Current diagnostic methods are based on psychiatric interviews, which are subjective in nature. The lack of disease biomarkers to support objective laboratory tests has been a long-standing bottleneck in the clinical diagnosis and evaluation of schizophrenia. Here we report a global metabolic profiling study involving 112 schizophrenic patients and 110 healthy subjects, who were divided into a training set and a test set, designed to identify metabolite markers. A panel of serum markers consisting of glycerate, eicosenoic acid, β-hydroxybutyrate, pyruvate and cystine was identified as an effective diagnostic tool, achieving an area under the receiver operating characteristic curve (AUC) of 0.945 in the training samples (62 patients and 62 controls) and 0.895 in the test samples (50 patients and 48 controls). Furthermore, a composite panel by the addition of urine β-hydroxybutyrate to the serum panel achieved a more satisfactory accuracy, which reached an AUC of 1 in both the training set and the test set. Multiple fatty acids and ketone bodies were found significantly (P<0.01) elevated in both the serum and urine of patients, suggesting an upregulated fatty acid catabolism, presumably resulting from an insufficiency of glucose supply in the brains of schizophrenia patients.

Transcriptomic profiles of Japanese medaka (Oryzias latipes) in response to alkalinity stress

Oryzias latipes (Adrianichthyidae), known as Japanese medaka or Japanese killifish, is a small 2-4 cm long fish common in rice paddies in coastal Southeast Asia and is also a popular aquarium fish. It has been widely used as a research model because of its small size and because it is very easy to rear. Alkalinity stress is considered to be one of the major stressors on fish in saline-alkaline water. As very little is known about molecular genetic responses of aquatic organisms to alkalinity stress, we examined genome-wide gene expression profiles of Japanese medaka in response to carbonate alkalinity stress. Adult fish were exposed to freshwater and high carbonate alkaline water in the laboratory. We designed a microarray containing 26,429 genes for measuring gene expression change in the gills of the fish exposed to high carbonate alkalinity stress. Among these genes, 512 were up-regulated and 501 were down-regulated in the gills. These differentially expressed genes can be divided into gene groups using gene ontology, including biological processes, cellular components and molecular function. These gene groups are related to acid-base and ion regulation, cellular stress response, metabolism, immune response, and reproduction processes. Biological pathways including amino sugar and nucleotide sugar metabolism, porphyrin and chlorophyll metabolism, metabolism of xenobiotics by cytochrome P450, drug metabolism, aminoacyl-tRNA biosynthesis, glycine, serine and threonine metabolism, ascorbate and aldarate metabolism, pentose and glucuronate interconversions, glutathione metabolism, and fructose and mannose metabolism were significantly up-regulated. Alkalinity stress stimulates the energy and ion regulation pathways, and it also slows down the pathways related to the immune system and reproduction.

A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetes: a replication and meta-analysis of five cohorts

AIMS/HYPOTHESIS

In this study we aimed to replicate the previously reported association between the glycaemic response to metformin and the SNP rs11212617 at a locus that includes the ataxia telangiectasia mutated (ATM) gene in multiple additional populations.

METHODS

Incident users of metformin selected from the Diabetes Care System West-Friesland (DCS, n = 929) and the Rotterdam Study (n = 182) from the Netherlands, and the CARDS Trial (n = 254) from the UK were genotyped for rs11212617 and tested for an association with both HbA(1c) reduction and treatment success, defined as the ability to reach the treatment target of an HbA(1c) ≤ 7 % (53 mmol/mol). Finally, a meta-analysis including data from literature was performed.

RESULTS

In the DCS cohort, we observed an association between rs11212617 genotype and treatment success on metformin (OR 1.27, 95% CI 1.03, 1.58, p = 0.028); in the smaller Rotterdam Study cohort, a numerically similar but non-significant trend was observed (OR 1.45, 95% CI 0.87, 2.39, p = 0.15); while in the CARDS cohort there was no significant association. In meta-analyses of these three cohorts separately or combined with the previously published cohorts, rs11212617 genotype is associated with metformin treatment success (OR 1.24, 95% CI 1.04, 1.49, p = 0.016 and OR 1.25, 95% CI 1.33, 1.38, p = 7.8 × 10(-6), respectively).

CONCLUSIONS/INTERPRETATION

A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetic patients from the Netherlands and the UK. This is the first robustly replicated common susceptibility locus found to be associated with metformin treatment response.

Efficacy and safety of embolization in iatrogenic traumatic uterine vascular malformations

AIM

To retrospectively evaluate the efficacy of embolotherapy in patients with iatrogenic traumatic uterine arteriovenous malformations (AVMs).

MATERIALS AND METHODS

A retrospective review of all patients who underwent uterine arterial embolization in Peking Union Medical College Hospital between January 2000 and December 2010 was performed. Forty-two patients were diagnosed with a uterine vascular malformation. All patients had obstetric manipulations before. Serial beta-human chorionic gonadotropin (β-HCG) levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of bilateral uterine arteries. The complications, control of haemorrhage, and outcome of subsequent pregnancies were assessed.

RESULTS

A total of 49 embolization procedures were performed in 42 patients. Seven patients required repeated embolizations for recurrence of bleeding. The technical success rate of embolization was 100%. Bleeding was controlled in 35 of 42 patients (83%) after the first embolization procedures, and bleeding was controlled in another two patients who underwent repeat embolization at a median follow-up of 29 months (range 3 months to 5 years). The overall clinical success rate was 88% (37/42). Thirteen patients subsequently became pregnant and eight of 13 patients had uneventful intrauterine pregnancies carried to term. Seven patients had post-embolization syndrome and no other complication occurred.

CONCLUSION

Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. Future pregnancy is still possible after embolization.

Lag phase of Salmonella enterica under osmotic stress conditions

Salmonella enterica serovar Typhimurium was grown at salt concentrations ranging from 0.5 to 7.5% in minimal medium with and without added osmoprotectant and in a rich medium. In minimal medium, the cells showed an initial decline period, and consequently the definition of the lag time of the resultant log count curve was revised. The model of Baranyi and Roberts (Int. J. Food Microbiol. 23:277-294, 1994) was modified to take into account the initial decline period, based on the assumption that the log count curve of the total population was the sum of a dying and a surviving-then-growing subpopulation. The lag time was defined as the lag of the surviving subpopulation. It was modeled by means of a parameter quantifying the biochemical work the surviving cells carry out during this phase, the "work to be done." The logarithms of the maximum specific growth rates as a function of the water activity in the three media differed only by additive constants, which gave a theoretical basis for bias factors characterizing the relationships between different media. Models for the lag and the "work to be done" as a function of the water activity showed similar properties, but in rich medium above 5% salt concentrations, the data showed a maximum for this work. An accurate description of the lag time is important to avoid food wastage, which is an issue of increasing significance in the food industry, while maintaining food safety standards.

Laplace barriers for electrowetting thresholding and virtual fluid confinement

Reported are Laplace barriers consisting of arrayed posts or ridges that impart ∼100 to 1000 s of N/m(2) Laplace pressure for fluid confinement, but the Laplace pressure is also small enough such that the barriers are porous to electrowetting control. As a result, the barriers are able to provide electrowetting flow thresholding and virtual fluid confinement in noncircular fluid geometries. A simple theoretical model for the barriers and experimental demonstrations validate functionality that may be useful for lab-on-chip, display devices, and passive matrix control, to name a few applications.

Distribution of rDNA in the nucleus ofGiardia lamblia: detection by Ag-I silver stain

Previous investigations have proved that diplomonads have primitive cell nuclei and lack a nucleolus. We determined the distribution of ribosomal DNA (rDNA) in diplomonad nuclei that lacked a nucleolus. Giardia lamblia was used as the experimental organism with Euglena gracilis as the control. The distribution of rDNA was demonstrated indirectly by the modified Ag-I silver technique that can indicate specifically the nucleolus organizing region (NOR) by both light and electron microscopy. In ultrathin sections of silver stained Euglena cells, all silver grains were concentrated in the fibrosa of the nucleolus, while no silver grains were found in the cytoplasm, nucleoplasm, condensed chromosomes or pars granulosa of the nucleus. In the silver stained Giardia cells, no nucleolus was found, but a few silver grains were scattered in the nucleus. This suggests that the rDNA of Giardia does not form an NOR-like structure and that its nucleus is in a primitive state.

Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity

Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the gene. We previously described the importance of a specific haplotype at the 3' end of DAT1, as well as the identification of associated single nucleotide polymorphisms (SNPs) within or close to 5' regulatory sequences. In this study we replicate the association of SNPs at the 5' end of the gene and identify a specific risk haplotype spanning the 5' and 3' markers. These findings indicate the presence of at least two loci associated with ADHD within the DAT1 gene and suggest that either additive or interaction effects of these two loci on the risk for ADHD. Overall these data provide further evidence that genetic variants of the dopamine transporter gene confer an increased risk for ADHD.

Increased ROS generation and SOD activity in heteroplasmic tissues of transmitochondrial mice with A3243G mitochondrial DNA mutation

The mitochondrial A3243G tRNALeu(UUR) mutation associated with a variety of mitochondrial disorders results in a severe respiratory deficiency, an increase in reactive oxygen species (ROS) production and activities of anti-oxidative enzyme in vitro. However, the phenotypic implications of this mutation have not been described in vivo. Here, mitochondria carrying A3243G transition from the peripheral blood of diabetes mellitus patients were microinjected into zygotes. Influence of this mutation on mitochondrial respiratory enzyme activities, ROS generation, and anti-oxidative enzyme activities in the heteroplasmic tissues of transmitochondrial mice was evaluated. The chimeric mice exhibited a subtle impaired oxidative phosphorylation, reduced activity of complex I/IV, increased activity of superoxide dismutase, and in turn, enhanced ROS generation. Our results suggest that mitochondrial A3243G mutation may be responsible for the high ROS production in vivo. Increased generation of ROS caused by mtDNA mutation may also play a role in the pathogenesis of the A3243G mutation-associated diseases.

No association between two polymorphisms of the serotonin transporter gene and combined type attention deficit hyperactivity disorder

Several independent studies have reported association between serotonin transporter gene (SLC6A4) polymorphisms and attention deficit hyperactivity disorder (ADHD). Five studies found evidence for association between the long-allele of a 44-bp insertion/deletion polymorphism (5-HTTLPR) and ADHD. Another two studies corroborated this finding while a further six studies did not find such an association. For a second polymorphism within the gene, a variable number tandem repeat (VNTR) within intron 2, one study demonstrated that the 12/12 genotype was significantly less frequent in ADHD cases compared to controls, while a second study found that the 12-allele was preferentially transmitted to offspring affected with ADHD. To provide further clarification of the reported associations, we investigated the association of these two markers with ADHD in a sample of 1,020 families with 1,166 combined type ADHD cases for the International Multi-Centre ADHD Genetics project, using the Transmission Disequilibrium Test. Given the large body of work supporting the association of the promoter polymorphism and mood disorders, we further analyzed the group of subjects with ADHD plus mood disorder separately. No association was found between either of the two markers and ADHD in our large multisite study or with depression within the sample of ADHD cases.

A high-density SNP linkage scan with 142 combined subtype ADHD sib pairs identifies linkage regions on chromosomes 9 and 16

As part of the International Multi-centre ADHD Genetics project we completed an affected sibling pair study of 142 narrowly defined Diagnostic and Statistical Manual of Mental Disorders, fourth edition combined type attention deficit hyperactivity disorder (ADHD) proband-sibling pairs. No linkage was observed on the most established ADHD-linked genomic regions of 5p and 17p. We found suggestive linkage signals on chromosomes 9 and 16, respectively, with the highest multipoint nonparametric linkage signal on chromosome 16q23 at 99 cM (log of the odds, LOD=3.1) overlapping data published from the previous UCLA (University of California, Los Angeles) (LOD>1, approximately 95 cM) and Dutch (LOD>1, approximately 100 cM) studies. The second highest peak in this study was on chromosome 9q22 at 90 cM (LOD=2.13); both the previous UCLA and German studies also found some evidence of linkage at almost the same location (UCLA LOD=1.45 at 93 cM; German LOD=0.68 at 100 cM). The overlap of these two main peaks with previous findings suggests that loci linked to ADHD may lie within these regions. Meta-analysis or reanalysis of the raw data of all the available ADHD linkage scan data may help to clarify whether these represent true linked loci.

Co-transmission of conduct problems with attention-deficit/hyperactivity disorder: familial evidence for a distinct disorder

Common disorders of childhood and adolescence are attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD). For one to two cases in three diagnosed with ADHD the disorders may be comorbid. However, whether comorbid conduct problems (CP) represents a separate disorder or a severe form of ADHD remains controversial. We investigated familial recurrence patterns of the pure or comorbid condition in families with at least two children and one definite case of DSM-IV ADHDct (combined-type) as part of the International Multicentre ADHD Genetics Study (IMAGE). Using case diagnoses (PACS, parental account) and symptom ratings (Parent/Teacher Strengths and Difficulties [SDQ], and Conners Questionnaires [CPTRS]) we studied 1009 cases (241 with ADHDonly and 768 with ADHD + CP), and their 1591 siblings. CP was defined as > or =4 on the SDQ conduct-subscale, and T > or = 65, on Conners' oppositional-score. Multinomial logistic regression was used to ascertain recurrence risks of the pure and comorbid conditions in the siblings as predicted by the status of the cases. There was a higher relative risk to develop ADHD + CP for siblings of cases with ADHD + CP (RRR = 4.9; 95%CI: 2.59-9.41); p < 0.001) than with ADHDonly. Rates of ADHDonly in siblings of cases with ADHD + CP were lower but significant (RRR = 2.9; 95%CI: 1.6-5.3, p < 0.001). Children with ADHD + CP scored higher on the Conners ADHDct symptom-scales than those with ADHDonly. Our finding that ADHD + CP can represent a familial distinct subtype possibly with a distinct genetic etiology is consistent with a high risk for cosegregation. Further, ADHD + CP can be a more severe disorder than ADHDonly with symptoms stable from childhood through adolescence. The findings provide partial support for the ICD-10 distinction between hyperkinetic disorder (F90.0) and hyperkinetic conduct disorder (F90.1).

Point-by-point inscription of first-order fiber Bragg grating for C-band applications

The influence of the fiber geometry on the point-by-point inscription of fiber Bragg gratings using a femtosecond laser is highlighted. Fiber Bragg gratings with high spectral quality and strong first-order Bragg resonances within the C-band are achieved by optimizing the inscription process. Large birefringence (1.2x10(-4)) and high degree of polarization-dependent index modulation are observed in these gratings. Potential applications of these gratings in resonators are further illustrated.

Structure of Dicer and mechanistic implications for RNAi

Dicer is a specialized ribonuclease that processes double-stranded RNA (dsRNA) into small RNA fragments about 25 nucleotides in length during the initiation phase of RNA interference (RNAi). We previously determined the crystal structure of a Dicer enzyme from the diplomonad Giardia intestinalis and proposed a structural model for dsRNA processing. Here, we provide evidence that Dicer is composed of three structurally rigid regions connected by flexible hinges and propose that conformational flexibility facilitates dsRNA binding and processing. We also examine the role of the accessory domains found in Dicers of higher eukaryotes but absent in Giardia Dicer. Finally, we combine the structure of Dicer with published biochemical data to propose a model for the architecture of the RNA-induced silencing complex (RISC)-loading complex.

A retrospective exploratory study of the variability of radiologists’ measurements in a selected subgroup of subjects enrolled in a clinical trial

6523

A retrospective exploratory study of the variability of radiologists’ measurements in a selected subgroup of subjects enrolled in a clinical trial Background: Independent centralized review of imaging studies is an established means of validating data used in support of corporate ‘go-no go‘ decisions, regulatory approval, and post marketing claims. Despite best efforts at standardizing this process using the Response Evaluation Criteria in Solid Tumors (RECIST), there will be inherent differences in radiologic measurements. To define a concise value for the variation between a specific set of radiologists, the following study was performed. Methods: An experienced radiologist and a research intern reviewed digital Computerized Tomographic (CT) scans from 31 subjects to identify 150 primary and metastatic tumors. Tumors were categorized into 4 categories. [Category (Cat.) 1 - Defined Edge/Radially Symmetric, Cat. 2 - Defined Edge/Irregular Shape, Cat. 3 - Blurred Edge/Radially Symmetric, Cat. 4 - Blurred Edge/Irregular Shape] Fifteen radiologists independently measured each tumor. Mixed effects models controlling for different tumors were used to assess the variance. Results Overall, the between reader variations accounted for 4.15% percent of total errors for the length. The respective between reader and the random errors are 0.32 (95% CI: 0.14, 0.77) and 7.51 (95%CI: 7.08, 8.01). The data shows that the variances are smallest for category 1 tumors (total error: 1.45) and largest for category 4 tumors (total error: 20.79). The total error for categories 2 and 3 are listed in Table 1 below. Conclusions The (low reader error) / (total error) verifies that the radiologists were only responsible for a small portion of the total error, and suggests these 15 radiologists measuring a tumor will be comparable to one of these radiologists measuring the tumor many times.

No significant financial relationships to disclose.

[Table: see text]

Inter-observer variability in chemotherapy trials for pancreatic cancer

6522

Background: No studies have examined differences in imaging assessment of drug response for unresectable pancreatic cancer between investigators and independent central review panels. This study reports such discrepancies. Methods: 133 patients in two multi-center, randomized Phase II drug trials had their response assessed by measurement of tumor size or new lesions on serial CT scans. Protocols specified techniques for tumor measurement and defined responses as complete (CR) or partial responses (PR), stable (SD) or progressive disease (PD). Objective responses were confirmed by repeat imaging evaluations after an interval > 4 weeks. Cases of PR or SD withdrawn from the study <8 weeks after enrollment were scored as non-evaluable (NE). The same images were then blindly reviewed by protocol trained radiologists at an Independent Core Lab. Cases of discordance in the interpretation of best response between investigators and reviewers were then blindly re-reviewed by an independent adjudicator. Results: In 50/133 cases (38%), there was sufficient discrepancy between investigators and reviewers to result in a change in overall response. In 10 cases (8%), investigators reported responses inconsistent with protocol standards for their tumor measurements. In 40 cases (30%), reviewers disagreed with the radiological findings of the investigators. In 47 of the 50 cases, the films were available for a second review by the adjudicator who confirmed the reviewers’ assessment of response in 39/47 (83%) of cases. Discrepancies in assessment of response were not randomly distributed. Investigators reported significantly more confirmed objective responses (CR + PR) than reviewers even after investigators’ response coding errors were corrected. As shown in Table 1 , investigators reported favorable responses in 21/133 (16%) cases compared with 6/133 (5%) responses noted by reviewers (p=0.01). Conclusions: The results support the use of independent review of trial data when the endpoint of the trial (response rate) is based on imaging data.

[Table: see text]

Competing relaxation mechanisms in a disclinated nanowire: temperature and size effects

This Letter reports a molecular dynamics study of the temperature and size dependence of disclination relaxation in a bicrystalline titanium nanowire. The simulations show that an unstable disclination may relax via crack nucleation and/or structural transformation. The critical disclination strength to nucleate a crack decreases with the nanowire diameter at 0 K, but an inverse relation may exist at higher temperatures. Similar relaxation mechanisms are operative in other hcp materials. The results suggest that grain boundaries in nanostructured materials can be disordered through disclinations which relax via amorphization.

The analysis of 51 genes in DSM-IV combined type attention deficit hyperactivity disorder: association signals in DRD4, DAT1 and 16 other genes

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, starting in early childhood and persisting into adulthood in the majority of cases. Family and twin studies have demonstrated the importance of genetic factors and candidate gene association studies have identified several loci that exert small but significant effects on ADHD. To provide further clarification of reported associations and identify novel associated genes, we examined 1,038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes. Analysis used within family tests of association in a sample of 776 DSM-IV ADHD combined type cases ascertained for the International Multi-centre ADHD Gene project. We found nominal significance with one or more SNPs in 18 genes, including the two most replicated findings in the literature: DRD4 and DAT1. Gene-wide tests, adjusted for the number of SNPs analysed in each gene, identified associations with TPH2, ARRB2, SYP, DAT1, ADRB2, HES1, MAOA and PNMT. Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples.

Microchannels in conventional single-mode fibers

Microchannels are fabricated into conventional single-mode fibers by femtosecond laser processing and chemical etching. Fabrication limitations imposed by the fiber geometry are highlighted and resolved through a simple technique without compromising fabrication flexibility. A microfluidic fiber device consisting of a 4 microm wide microchannel that intersects the fiber core for refractive index sensing is further demonstrated.

Phase III adjuvant trial of concurrent epirubicin/taxane vs. sequential epirubicin/cyclophosphamide followed by taxane for node positive breast cancer

573

Background: This study evaluates whether concurrent epirubicin/taxane (ET) improves disease-free survival (DFS) at 3 yrs compared to the sequential combination of epirubicin/cyclophosphamide followed by a taxane (EC>T) in pts with operable node (+) breast cancer. Methods: Eligible pts were randomized to receive either ET (E 75 mg/m 2) for 8 cycles q21 days or EC>T (E 90 mg/m 2, C 600 mg/m2) for 4 cycles, followed by 4 cycles of a taxane q21 days. Choice of T (paclitaxel 175 mg/m2 or docetaxel 75 mg/m 2) was at the physician’s discretion. The primary endpoint is DFS. A 0.10 increase in the probability of DFS at 3 yrs for the ET arm would be considered clinically relevant. To detect 82 events, 300 subjects per arm are required to provide 90% power at 5% significance level. Results: 617 pts were enrolled from Nov 2000 to June 2003; 308 pts received ET and 309 pts received EC>T. Both treatment arms were well balanced with respect to age, nodal+, ER status, Her-2+ and PS; median age 52.5 (42%<50 years old); 70% ER+; 61% LN (1–3); 16% Her-2+; 87% PS 0. Total of 2206 cycles of treatment were given to ET compared 2314 cycles of treatment to EC>T. At 30 months of median follow-up there were DFS 102 events occurred; 47 events in ET arm (16%) and 55 events in EC>T arm (18%); 63 total deaths; 29 deaths in ET arm and 34 deaths in EC>T arm. The most common toxicities include alopecia (50%), fatigue (31%), nausea and vomiting (30%), dyspepsia (27%), febrile neutropenia (15%), constipation (12%), diarrhea (10%), arthralgia (11%), stomatitis (10%). In cardiac safety f/u, only one pt in ET arm remained LVEF drop >15. Conclusions: Epirubicin can be combined with taxanes in both sequential and concurrent therapies and both regimens are effective and well tolerated. The study is sponsored by Pfizer Inc.

No significant financial relationships to disclose.

Sequence variation and gene duplication at MHC DQB loci of baiji (Lipotes vexillifer), a Chinese river dolphin

The major histocompatibility complex (MHC) is a fundamental part of the vertebrate immune system, and the high variability in many MHC genes is thought to play an important role in the recognition of parasites. Baiji (Lipotes vexillifer) is one of the most endangered species in the world. Its wild population has declined to fewer than 100 individuals and has a very high risk of becoming extinct in the near future. In this study we present a first step in the molecular characterization of a DQB-like locus of baiji by nucleotide sequence analysis of the polymorphic exon 2 segments. In the examined 172 bp sequences from a group of 18 incidentally captured or stranded individuals, 48 variable sites were determined and 43 alleles were identified, many of which were represented by only one clone. Three to seven alleles were found in each individual, suggesting gene duplications. No deletion, insertion, or exceptional stop codon was detected, suggesting these alleles function in vivo. Phylogenetic reconstruction using neighbor joining grouped the 43 alleles into two distinct lineages, differing by seven nucleotides and four amino acids. Substitutions of amino acids tend to be clustered around sites postulated to be responsible for selective peptide recognition. In the peptide-binding region (PBR) of the DQB locus, the average number of nonsynonymous substitutions per site is greater than that of synonymous substitutions per site (0.1962 versus 0.0256, respectively). Nucleotide and amino acid sequences both showed a relatively high level of similarity (nucleotides 90.6%; amino acids 80.6%) to those of beluga whale (Delphinapterus leucas) and narwhal (Monodon monoceros). The high level of baiji MHC polymorphism revealed in the present study has not been reported in other cetaceans and could be a consequence of the small baiji population adapting to freshwater with a relatively high level of pathogens.

Linkage Disequilibrium and Haplotype Architecture for two ABC Transporter Genes (ABCC1 and ABCG2) in Chinese Population: Implications for Pharmacogenomic Association Studies

Information about linkage disequilibrium (LD) patterns and haplotype structures for candidate genes is instructive for the design and analysis of genetic association studies for complex diseases and drug response. ABCC1 and ABCG2 are genes coding for two multidrug resistance (MDR) associated transporters; they are also related to some pathophysiological traits. To pinpoint the LD profiles of these MDR genes in Chinese, we systemically screened 27 unrelated individuals for single nucleotide polymorphisms (SNPs) in the coding and regulatory regions of these genes, and thereby characterized their haplotype structures. Despite marked variations in haplotype diversity, LD pattern and intragenic recombination intensity between the two genes, both loci could be partitioned into several LD blocks, in which a modest number of haplotypes accounted for a high fraction of the sampled chromosomes. We concluded that each locus has its own genomic LD profile, but that they still share a common segmental LD architecture with low haplotype diversity. Our data will benefit genetic association studies of complex traits and drug response possibly related to these genes.

[Molecular genetic marker identification of traditional Chinese drug hippocampus]

Ancient DNA technique was used to extract DNA from 5 species of Chinese traditional drugs Hippocampus. The 12S rRNA gene fragment and cytochrome b gene fragment were amplified from DNA extract using Polymerase Chain Reaction (PCR) method. Restriction Fragment Length Polymorphism (RFLP) analysis and DNA sequence analysis were performed. The RFLP analysis method can identify 2 species of Hippocampus. The molecular genetic markers produced by DNA sequence method can identify all 5 species of Hippocampus. This method will be valuable for the identification of other animal drugs.

[Molecular identification of the Chinese drug turtle shells]

This paper reports a new method to identify the Chinese drug turtle shells using PCR product direct sequencing method. DNA was extracted from tissues of the Chinese three-keeled pond turtle Chinemys reevesii and 20 other species of turtles occurring in China and Southeast Asian countries. One hundred and ten base pairs of mitochondrial 12S rRNA gene fragment were amplified from the extract using PCR technique and obtained sequences. These sequences were used to construct 12S rRNA gene fragment sequence database for the 21 turtle species. Comparison of these sequences indicated that the sequence from the Chinese three-keeled pond turtle is different from that of all the other 20 turtle species. The sequence divergence is 3.7-15.7%. DNA was extracted from 0.1-0.5 g of shell from 19 turtle shells provided by the Jiangsu Institute for Drug Control and 12S rRNA gene fragment was amplified and sequenced. Comparison of the sequences from the 19 turtle shells and 12S rRNA gene fragment sequence database indicated that only 3 samples are shells of the Chinese three-keeled pond turtle specified in the Phamacopoeia of the People's Republic of China and the others are substitutes. The technique used in the present paper was found to be effective and reliable for the identification of turtle shells.

SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in met astasis of hepatocellular carcinoma (HCC).

METHODS: SF/HGF and c-met transcri ption and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve.

RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HG F autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P < 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P < 0.05).

CONCLUSION: The system of SF/HGF-c- met autocrine and paracrine played an important role in development and metastas is potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

[Expression of the artificial cecropin CMIV-like gene of Chinese silkworm Bombyx mori in Laphygma exigua larvae]

The synthesized CMIV-like Gene was linked with the signal peptide gene of nature silkworm antibacterial peptide and was inserted into baculovirus expression vector pFastBac 1, construcing a recombinant transposing vector. The vector was transformed into DH10Bac competent E. coli cells. The recombinant Bacmid was obtained. The recombinant Bacmid was transfected into sf21 cells to get the recombinant virus. Laphygma exigua larvae were infected with the recombinant virus to express the antibacterial peptide. The hemolymph were tested to have antibacterial activity. The active antibacterial peptide was purified by acid polyacrylamide electrophoresis. The specific expression of mRNA of CMIV-like Gene was tested using Northern blotting.

[Study on relationship between the reflux laryngitis and gastroesophageal reflux disease]

OBJECTIVE

To investigate the relationship between reflux laryngitis and gastroesophageal reflux disease (GRED).

METHOD

130 Patients of refractory chronic laryngitis with upper endoscopy and ambulatory 24-hr esophageal pH-metry. The patients of gastroesophageal reflux disease were divided into two groups. Group A was treated with antacids and motile medications. Group B was control.

RESULT

45 (34.6%) gastroesophageal reflux disease were found in 130 cases. 21 cases(91.3%) were healed in group A. 3 of 22 cases (13.6%) were healed in control (P < 0.01).

CONCLUSION

The gastroesophageal reflux disease was an important cause of the reflux laryngitis which symptoms and signs can be healed by antacids and motile medications.

Antioxidant properties of phenolic diterpenes from Rosmarinus officinalis

AIM

To investigate the inhibition capacities of carnosol, rosmanol, and epirosmanol, which are phenolic diterpenes from Rosmarinus officinalis, to oxidized low-density lipoprotein (LDL) formation in human blood and detect their scavenging activities to lipid free radical and superoxide anion in vitro.

METHODS

The antioxidant activities which were expressed with the inhibilities to lipid free radicals in the membrane lipid of cell and oxidized LDL formation were evaluated by TBARS assay and ESR method. The inhibition on the Cu2+-mediated oxidization of apo B formation in LDL was investigated by fluorescence spectroscopy.

RESULTS

Carnosol, rosmanol, and epirosmanol had an inhibitory activity to lipid peroxidation and oxidized apo B formation in human bloods LDL. The IC50 were 7-10 micromol/L. The antioxidant mechanism was related to the scavenging activities to lipid free radical.

CONCLUSION

carnosol, rosmanol, and epirosmanol showed the activity in inhibiting LDL oxidation.

Direct pK(a) measurement of the active-site cytosine in a genomic hepatitis delta virus ribozyme

Hepatitis delta virus ribozymes have been proposed to perform self-cleavage via a general acid/base mechanism involving an active-site cytosine, based on evidence from both a crystal structure of the cleavage product and kinetic measurements. To determine whether this cytosine (C75) in the genomic ribozyme has an altered pK(a) consistent with its role as a general acid or base, we used (13)C NMR to determine its microscopic pK(a) in the product form of the ribozyme. The measured pK(a) is moderately shifted from that of a free nucleoside or a base-paired cytosine and has the same divalent metal ion dependence as the apparent reaction pK(a)'s measured kinetically. However, under all conditions tested, the microscopic pK(a) is lower than the apparent reaction pK(a), supporting a model in which C75 is deprotonated in the product form of the ribozyme at physiological pH. While additional results suggest that the pK(a) is not shifted in the reactant state of the ribozyme, these data cannot rule out elevation of the C75 pK(a) in an intermediate state of the transesterification reaction.

[Comparison of enhancement patterns of multi-phase scan of dynamic MRI and dynamic CT in small hepatocellular carcinoma]

OBJECTIVE

To study prospectively the enhancement features of multi-phase scan of dynamic MRI and spiral CT in the diagnosis of small hepatocellular carcinoma (SHCC) and to discuss the cause of dynamic MRI being superior to spiral CT.

METHODS

Multi-phase contrast scanning of dynamic MR and spiral CT were done in 53 SHCC patients. The lesions were proved by surgery and pathology. The arterial-phase, portal venous-phase and delayed phase scan of spiral CT were carried out after the pre-contrast scanning of the entire liver. MRI was performed with SE sequence and FMPSPGR sequence dynamic multi-phase contrast scans.

RESULTS

Seventy-six lesions were found in 53 patients. Sixty-nine lesions and 54 lesions were enhanced obviously in MR and spiral CT arterial-phase scans. The typical enhancement patterns of SHCC in the arterial-phase, portal venous-phase and delayed phase scan of MRI and spiral CT were hyper-hypo-hypointense (dense) and hyperintense (hyperdense), -isointense (isodense) and -hypointense (hypodense). Atypical enhancement patterns were hyperintense (hyperdense), -hyperintense (hyperdense), -hyperintense (hyperdense), -hyperintense (hyperdense), -isointense (isodense), -isointense (isodense) and -hypointense- (hypodense), -hypointense (hypodense) and -hypointense (hypodense).

CONCLUSION

Both dynamic MRI and spiral CT multi-phase contrast scanning are able to demonstrate the enhancement features of SHCC, with arterial-phase scan of MRI being superior to spiral CT in reflecting the hypervascular characterization of SHCC. Combined with SE sequence in characterizing the SHCC, MRI is better than spiral CT.

Gene expression profiling in human fetal liver and identification of tissue- and developmental-stage-specific genes through compiled expression profiles and efficient cloning of full-length cDNAs

Fetal liver intriguingly consists of hepatic parenchymal cells and hematopoietic stem/progenitor cells. Human fetal liver aged 22 wk of gestation (HFL22w) corresponds to the turning point between immigration and emigration of the hematopoietic system. To gain further molecular insight into its developmental and functional characteristics, HFL22w was studied by generating expressed sequence tags (ESTs) and by analyzing the compiled expression profiles of liver at different developmental stages. A total of 13,077 ESTs were sequenced from a 3'-directed cDNA library of HFL22w, and classified as follows: 5819 (44.5%) matched to known genes; 5460 (41.8%) exhibited no significant homology to known genes; and the remaining 1798 (13.7%) were genomic sequences of unknown function, mitochondrial genomic sequences, or repetitive sequences. Integration of ESTs of known human genes generated a profile including 1660 genes that could be divided into 15 gene categories according to their functions. Genes related to general housekeeping, ESTs associated with hematopoiesis, and liver-specific genes were highly expressed. Genes for signal transduction and those associated with diseases, abnormalities, or transcription regulation were also noticeably active. By comparing the expression profiles, we identified six gene groups that were associated with different developmental stages of human fetal liver, tumorigenesis, different physiological functions of Itoh cells against the other types of hepatic cells, and fetal hematopoiesis. The gene expression profile therefore reflected the unique functional characteristics of HFL22w remarkably. Meanwhile, 110 full-length cDNAs of novel genes were cloned and sequenced. These novel genes might contribute to our understanding of the unique functional characteristics of the human fetal liver at 22 wk.

Lack of correlation of vacA genotype, cagA gene of Helicobacter pylori and their expression products with various gastroduodenal diseases

OBJECTIVE

To investigate the correlation among vacA genotypes, cagA gene, VacA, serum CagA antibodies of Helicobacter pylori (H. pylori) and gastroduodenal diseases.

METHODS

vacA genotypes and cagA gene of 62 H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were tested by polymerase chain reaction, and Hela cell assay for VacA activity in vitro. Serum CagA antibodies were measured by EIA method in the same patients.

RESULTS

All 62 H. pylori strains possessed the vacA gene and vacA genotypes of all strains were type s1a/m2. Total positive rate of cagA gene was 56.45%; the positive rates of cagA gene of H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were 55.56%, 54.17% and 63.64%, respectively (P > 0.05). The total positive rate of VacA was 37.10%; the positive rates of VacA produced by H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were 33.33%, 29.17% and 63.64%, respectively (P > 0.05). The positive rates of CagA antibodies in patients with chronic gastritis, peptic ulcer and gastric cancer were 70.37%, 79.17% and 40.00%, respectively (P > 0.05). The total positive rate of CagA antibodies was 68.85%.

CONCLUSION

There was no correlation among cagA gene and vacA genotypes of H. pylori, VacA, serum CagA antibodies and various gastroduodenal diseases.

[Mitochondrial mechanisms of CPT-induced apoptosis in nasopharyngeal carcinoma cells]

OBJECTIVE

To understand whether CPT-induced apoptosis is related to the alteration of mitochondrial transmembrane potentials (delta psi m).

METHOD

A low differentiation human nasopharyngeal carcinoma (NPC) cell line of CNE-2Z cells were used as in vitro model. After treatment with 2 mumol/L CPT for 24 h, the delta psi m was detected by the staining of rhodamine 123 (Rh123), while apoptosis was confirmed by sub-G1 cell content and the double staining of hoechst33258 and propidium iodide (PI).

RESULT

CPT induced delta psi m collapse and apoptosis. With 2 mumol/L CPT treatment for 24 h, delta psi mlow cell was increased to (19.0 +/- 3.0)%, while in the DMSO control, delta psi mlow was (7.0 +/- 1.4)% P < 0.05.

CONCLUSION

The disruption of the delta psi m may be one of the mechanisms of CPT-induced apoptosis in CNE-2Z cells.

Overexpression, biophysical characterization, and crystallization of ribonuclease I from Escherichia coli, a broad-specificity enzyme in the RNase T2 family

We have constructed a strain that overproduces ribonuclease I of Escherichia coli and we have purified large quantities of the enzyme. Data from fluorescence, CD, and DSC measurements showed that it was a very stable protein. The conformation energy determined from urea and guanidine hydrochloride denaturation experiments was 11.5 kcal mol(-1) at pH 7.5. Thermal denaturation studies indicated that it had a T(m) of 64 degrees C at pH 4.0. RNase I belongs to the RNase T2/S-RNase group of endoribonucleases, but near the amino terminus it has an unusually long hydrophilic segment. Part of this was removed in the deletion construct, RNase I Delta(26-38). We have obtained crystals of both RNase I and of an enzyme-G2'p5'G complex in the P2(1) space group and oligonucleotide complexes with both wild type and mutant enzymes. The current study lays the groundwork for extensive investigation into the structure, function, and physical properties of this widely distributed group of ribonucleases.