Characterization of Thinopyrum distichum chromosomes using double fluorescence in situ hybridization, RFLP analysis of 5S and 26S rRNA, and C-banding of parents and addition lines

Diagnostic markers for eight Thinopyrum distichum addition chromosomes in Triticum turgidum were established using C-banding, in situ hybridization, and restriction fragment length polymorphism analysis. The C-band karyotype conclusively identified individual Th. distichum chromosomes and distinguished them from chromosomes of T. turgidum. Also, TaqI and BamHI restriction fragments containing 5S and 18S-5.8S-26S rRNA sequences were identified as positive markers specific to Th. distichum chromosomes. Simultaneous fluorescence in situ hybridization showed both 5S and 18S-5.8S-26S ribosomal RNA genes to be located on chromosome IV. Thinopyrum distichum chromosome VII carried only a 18S-5.8S-26S rRNA locus and chromosome pair II carried only a 5S rRNA locus. The arrangement of these loci on Th. distichum chromosome IV was different from that on wheat chromosome pair 1B. Two other unidentified Th. distichum chromosome pairs also carried 5S rRNA loci. The homoeologous relationship between Th. distichum chromosomes IV and VII and chromosomes of other members of the Triticeae was discussed by comparing results obtained using these physical and molecular markers.

Effect of the anticoagulant ethylenediamine tetra-acetic acid (EDTA) on the estimation of pharmacokinetic parameters: A case study with tigecycline and ciprofloxacin

Tigecycline and ciprofloxacin were employed as the model compounds to study the effect of the anticoagulant ethylenediamine tetra-acetic acid (EDTA), which is used during plasma sample preparations, on the determination of pharmacokinetic parameters. The pharmacokinetic parameters were determined in rats following intravenous infusion with blood samples collected in serum separators, with either EDTA- or heparin-coated tubes. The blood-to-plasma (B:P) partition ratio and plasma protein binding were determined in vitro in rat or human blood collected in either EDTA- or heparin-coated tubes. Drug concentrations were quantified by liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) analysis. In tigecycline-treated rats drug concentrations were twofold lower in EDTA plasma, leading to a twofold lower area under plasma concentration-time curve (AUC) and twofold higher plasma clearance values as compared with those obtained from heparin plasma. No differences were noted in the pharmacokinetic parameters obtained from heparin-treated plasma versus serum. The B:P partition ratio and unbound fraction for tigecycline were significantly higher in EDTA-treated blood. When normalized to the B:P partition ratios, the tigecycline blood clearance values were identical between samples collected in EDTA- or heparin-coated tubes. Similar but smaller differences were observed for ciprofloxacin. It was concluded that EDTA might compete with tigecycline and ciprofloxacin for chelating metal ions and thus affect drug partition between blood and plasma compartments, leading to inaccurate measurement of pharmacokinetic parameters in plasma.

432. How do antiphospholipid antibodies contribute to preeclampsia?

Preeclampsia is characterised by elevated maternal blood pressure which is preceded by endothelial activation. The cause of this endothelial cell dysfunction is unclear but it appears to be triggered by a placental factor. One of the risk factors for developing preeclampsia is the presence of antiphospholipid antibodies (aPL) in the maternal blood but exactly how aPL predispose women to developing preeclampsia is unclear. A second feature known to be associated with preeclampsia is excessive shedding and deportation of dead trophoblasts. We have previously shown that shed trophoblasts are phagocytosed by endothelial cells and that phagocytosis of necrotic trophoblasts leads to endothelial cell activation1. In this study we examined the hypothesis that aPL alter the number or nature of trophoblasts shed from the placenta resulting in endothelial cell activation. Using our published model of trophoblast shedding 2 human first trimester placental explants were treated with monoclonal aPL, IIC5 or ID2, or control antibody CD45 for 72 h. Shed trophoblasts then were harvested and counted using a Cellometer AutoT4 automated cell counter. The activity of caspases 3&7 was analysed in all treated shed trophoblasts using a FLICA™ kit. The treated shed trophoblasts also were exposed to the endothelial cell line HMEC-1 for 24 h. The level of ICAM-1 by HMEC-1 was determined by cell-based ELISA. The number of trophoblasts shed from placental explants was increased 2 fold following aPL treatment whereas, treatment with CD45 resulted in only a 1.3 fold increase in shedding. Trophoblasts shed from aPL-treated explants contained less active caspases 3 & 7 compared with control shed trophoblasts. Moreover, phagocytosis of trophoblasts shed from aPL-treated explants induced significantly increased expression of ICAM-1 compared with controls. aPL treatment affected the number and nature of trophoblasts shed from placentae in such a way that phagocytosing endothelium become activated. These findings suggest that aPL treatment may have shifted the type of cell death that shed trophoblasts are undergoing from apoptosis to a more necrotic or aponecrotic mechanism. This type of shedding of trophoblasts in vivo might contribute to the endothelial cell activation which is a hallmark feature of preeclampsia. (1) Chen Q, Stone PR, McCowan LM et al. Phagocytosis of necrotic but not apoptotic trophoblasts induces endothelial cell activation. Hypertension. 2006;47:116–121. (2) Abumaree MH, Stone PR, Chamley LW. An in vitro model of human placental trophoblast deportation/shedding. Mol Hum Reprod. 2006;12:687–694.

The role of the proto-oncogene ETS2 in acute megakaryocytic leukemia biology and therapy

Acute myeloid leukemia (AML) in Down syndrome (DS) children has several unique features including a predominance of the acute megakaryocytic leukemia (AMkL) phenotype, higher event-free survivals compared to non-DS children using cytosine arabinoside (ara-C)/anthracycline-based protocols and a uniform presence of somatic mutations in the X-linked transcription factor gene, GATA1. Several chromosome 21-localized transcription factor oncogenes including ETS2 may contribute to the unique features of DS AMkL. ETS2 transcripts measured by real-time RT-PCR were 1.8- and 4.1-fold, respectively, higher in DS and non-DS megakaryoblasts than those in non-DS myeloblasts. In a doxycycline-inducible erythroleukemia cell line, K562pTet-on/ETS2, induction of ETS2 resulted in an erythroid to megakaryocytic phenotypic switch independent of GATA1 levels. Microarray analysis of doxycycline-induced and doxycycline-uninduced cells revealed an upregulation by ETS2 of cytokines (for example, interleukin 1 and CSF2) and transcription factors (for example, TAL1), which are key regulators of megakaryocytic differentiation. In the K562pTet-on/ETS2 cells, ETS2 induction conferred differences in sensitivities to ara-C and daunorubicin, depending on GATA1 levels. These results suggest that ETS2 expression is linked to the biology of AMkL in both DS and non-DS children, and that ETS2 acts by regulating expression of hematopoietic lineage and transcription factor genes involved in erythropoiesis and megakaryopoiesis, and in chemotherapy sensitivities.

Gene expression profiles in HPV-infected head and neck cancer

Epidemiological and laboratory evidence indicate that, in addition to tobacco and alcohol, human papillomaviruses (HPV) play an important aetiological role in a subset of head and neck squamous cell carcinoma (HNSCC). To evaluate the molecular pathogenesis of HPV-infected HNSCC, we compared gene expression patterns between HPV-positive and -negative HNSCC tumours using cDNA microarrays. Tumour tissue was collected from 42 histologically confirmed HNSCC patients from an inner-city area of New York. Total DNA and RNA were extracted and purified from frozen tumour samples and gene expression levels were compared to a universal human reference RNA standard using a 27 323 cDNA microarray chip. HPV detection and genotyping were performed using an MY09/11-PCR system and RT-PCR. HPV was detected in 29% of HNSCC tumours. Most harboured only HPV16 and expressed the HPV16-E6 oncogene. HPV prevalence was highest in pharyngeal tumours (45%). Gene expression patterns that differentiated HPV-positive from negative tumours were compared by supervised classification analysis, and a multiple-gene signature was found to predict HPV16 prevalence in primary HNSCC with a false discovery rate < 0.2. Focusing on never-smokers, we further identified a distinct subset of 123 genes that were specifically dysregulated in HPV16-positive HNSCC. Overexpressed genes in HPV-positive HNSCC tumours included the retinoblastoma-binding protein (p18), replication factor-C gene, and an E2F-dimerization partner transcription factor (TFDP2) that have also been found to be overexpressed in cervical cancer. An additional subset of genes involved in viral defence and immune response, including interleukins and interferon-induced proteins, was found to be down-regulated in HPV-positive tumours, supporting a characteristic and unique transcriptional profile in HPV-induced HNSCC.

Identification of contaminant sources in enclosed spaces by a single sensor

To protect occupants from infectious diseases or possible chemical/biological agents released by a terrorist in an enclosed space, such as an airliner cabin, it is critical to identify gaseous contaminant source locations and strengths. This paper identified the source locations and strengths by solving inverse contaminant transport with the quasi-reversibility (QR) and pseudo-reversibility (PR) methods. The QR method replaces the second-order diffusion term in the contaminant transport equation with a fourth-order stabilization term. By using the airflow pattern calculated by computational fluid dynamics (CFD) and the time when the peak contaminant concentration was measured by a sensor in downstream, the QR method solves the backward probability density function (PDF) of contaminant source location. The PR method reverses the airflow calculated by CFD and solves the PDF in the same manner as the QR method. The position with the highest PDF is the location of the contaminant source. The source strength can be further determined by scaling the nominal contaminant concentration computed by CFD with the concentration measured by the sensor. By using a two-dimensional and a three-dimensional aircraft cabin as examples of enclosed spaces, the two methods can identify contaminant source locations and strengths in the cabins if the sensors are placed in the downstream location of the sources. The QR method performed slightly better than the PR method but with a longer computing time.

PRACTICAL IMPLICATIONS

The paper presents a method that can be used to find a gaseous contaminant source location and determine its strength in enclosed spaces with the data of contaminant concentration measured by one sensor. The method can be a very useful tool to find where, what, and how the contamination has happened. The method is also useful for optimally placing sensors in enclosed spaces. The results can be applied to develop appropriate measures to protect occupants in enclosed environments from infectious diseases or chemical/biological warfare agents released by a terrorist.

Advanced glycation end products inhibit production and activity of matrix metalloproteinase-2 in human umbilical vein endothelial cells

The aim of this study was to investigate the effects of advanced glycation end products (AGEs) on the expression and activity of matrix metalloproteinases-2 (MMP-2) in human umbilical vein endothelial cells (HUVECs). Cultured HUVECs were incubated with various concentrations of AGEs-modified albumin or unmodified albumin for different time periods. Protein and gene expression of MMP-2 and the receptor for AGEs (RAGE) were measured by Western blot and reverse transcription-polymerase chain reaction, respectively. The activity of MMP-2 in the conditioned medium was measured by gelatin zymography. The AGE-modified albumin inhibited MMP-2 but increased RAGE protein and gene expression in HUVECs in a concentration- and time-dependent manner. An inhibition of MMP-2 activity was also detected in the conditioned medium of HUVECs incubated with AGEs-modified albumin. In conclusion, AGEs inhibited the expression and activity of MMP-2 in HUVECs; this may be mediated through upregulation of RAGE.

Interleukin-18 gene polymorphisms and haplotypes in patients with oral lichen planus: a study in an ethnic Chinese cohort

Interleukin (IL)-18, a proinflammatory cytokine, induces T-helper 1 differentiation and cytotoxic T-lymphocyte functions, both of which have been proposed in the pathogenesis of oral lichen planus (OLP) - an oral disease resembles oral mucosal graft-versus-host disease (GVHD) both clinically and histologically. The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) in the IL18 gene on the chromosome 11q22 in patients with OLP. Four SNPs of the IL18 gene at positions -137G/C (rs187238), -607C/A (rs1946518), -656G/T (rs1946519), and 1248A/G (rs189667) were analyzed in 151 patients with OLP and 143 normal controls using polymerase chain reaction-sequence-specific primers method, and the serum level of IL-18 protein was determined by enzyme-linked immunosorbent assay (ELISA). The data revealed that there is a significant difference in IL18-607 genotype distributions between the patient group and the control group (P < 0.001), and the polymorphism -137G/C also appears to be statistically associated with the more severe erosive subtype (eOLP) (P = 0.023). The identified polymorphisms at the IL-18 promoter region (i.e. -137GG) are likely to exert positive effect on the production of IL-18 protein in OLP, as detected by ELISA. Using phase software, four haplotypes were deduced from the two polymorphisms -607C/A and -137G/C, named haplotypes I to IV, and the haplotypes I, II, and IV are significantly associated with OLP (P < 0.001). Our data suggest that the identified IL18 polymorphisms may be associated with the pathogenesis of OLP in this Chinese cohort by upregulation of IL-18 production in vivo.

Theoretical and numerical studies of coupling multizone and CFD models for building air distribution simulations

Multizone network models employ several assumptions, such as uniform temperature and pressure and quiescent air inside a zone, which may lead to inaccurate results in flow calculations. These assumptions can be eliminated in the zones, where the assumptions are inappropriate, by coupling a multizone network program with a computational fluid dynamics (CFD) program. Through theoretical analysis, this paper proves that the solution of air distribution by using the coupled program exists and is unique. Three possible coupling methods have been discussed in the paper. The best method is pressure-pressure coupling that exchanges pressure between the multizone and CFD because it is most stable and can always lead to a converged solution. Numerical tests were further performed to verify the theory and it demonstrated that the coupled program is able to effectively improve the accuracy of the results.

PRACTICAL IMPLICATIONS

The results of this paper provide a theoretical basis for improving the accuracy for modeling airflow and contaminant distributions in buildings. The coupled multizone and computational fluid dynamics can give high fidelity results, so field measurements may not be needed in the future. Designers of indoor environment in the future can use such a tool to evaluate different alternatives in design and identify the best solution for a building that can provide a healthy indoor environment.

Pharmacokinetics and lung-targeting characterization of a newly formulated enrofloxacin preparation

A new lung-targeting and controlled releasing preparation, enrofloxacin microsphere, was formulated and its physical properties, stability, pharmacokinetics and lung-targeting characteristics were tested in this study. The enrofloxacin microsphere prepared was demonstrated round and regular, which was easy to be dispersed and stable in both light stability test and heat stability test. Following intravenous administration of a single dose in dog, the drug concentration-time data in the lung were fitted most suitably with three-compartment open model. Compared with enrofloxacin injection (Baytril, half-life of distribution phase in the lung was shortened from 0.72 to 0.16 h, half-life of elimination phase in the lung was prolonged from 5.15 to 33.86 h and clearance of drug concentration in the lung was decreased from 0.603 to 0.267 L/h/kg. Lung-targeting parameters, including the relative intake rate (Re), targeting efficacy (Te) and the ratio of peak concentration (Ce), were calculated according to the pharmacokinetic parameters. The results showed that Re (2.48) and Ce (4.27) of the lung was much greater than that of other tissues and the ratio of Te(microsphere) to Te(Baytril) increased by a factor of 1.77 (compared with liver) to 3.51 (compared with spleen). Therefore, the enrofloxacin microsphere prepared in this study had controlled releasing and lung-targeting effects in dog.