Radiation dose in coronary artery angiography with 320-detector row CT and its diagnostic accuracy: comparison with 64-detector row CT

AIM

The aim of this study was the comparison of image quality, diagnostic accuracy and radiation dose of ECG-gated volume scan mode of 320-detector row CT with 64-detector row CT.

METHODS

A hundred and twenty patients receiving coronary artery CT angiography (CTA) were divided into two groups. Sixty patients in Group A underwent 64-detector row CTA; for the remainder, Group B, 320-detector row CT was used. Conventional coronary angiography was then performed in all patients. In Group B, patients with a pulse <65 beat/min underwent a prospective ECG-gated volume scan using a 70-80% R-R phase window and 1-beat, whereas a 30-80% R-R phase window, 2-beat CT was performed in patients with a pulse >65 beat/min.

RESULTS

In Group A, 247 vessels and 920 segments were assessed; in Group B, 242 and 906. In 320-detector row CTA, the coronary stenosis diagnosis' specificities were 98%, 96%, and 95% at the segmental, vessel, and patient levels, respectively (98%, 94%, and 92% in 64-detector row CTA); the negative predictive values were 99%, 98%, and 100% (98%, 97%, and 95% in 64-detector row CTA). There was no significant difference in specificity or negative predictive values between the groups. The average effective radiation dose in Group B was lower than in Group A (P<0.001). In Group B, the dose for 48 patients with 70-80% R-R phase window, 1-beat scan, was lower than for the remaining 12 patients (30-80% R-R phase window, 2-beat) (P<0.001).

CONCLUSION

The 320-detector CT reduces the radiation exposure by approximately 80% compared with 64-detector CT, with similar diagnostic accuracy and image quality.

Collisional transfer of population and orientation in NaK

Collisional satellite lines with |ΔJ| ≤ 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb(2) molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ΔJ that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)(1)Σ(+)(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ΔJ = even. Conversely, collisions with potassium atoms do not show this ΔJ = even propensity, but do show a propensity for ΔJ = positive compared to ΔJ = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured rate coefficients for broadening of NaK 3(1)Π ← 2(A)(1)Σ(+)spectral lines due to collisions with argon and potassium atoms. Additional broadening, due to velocity changes occurring in rotationally inelastic collisions, has also been observed.

Pharmacokinetics of dexmedetomidine in Chinese post-surgical intensive care unit patients

BACKGROUND

Dexmedetomidine is a rather new drug in China. We sought to describe the pharmacokinetics of dexmedetomidine in patients requiring post-operative sedation and ventilation in our surgical intensive care unit.

METHODS

Twenty-two patients received post-operative infusions of dexmedetomidine at 6 μg/kg/h for 10 min, followed by 0.4 μg/kg/h for 350 min. Venous blood samples were drawn and assayed for plasma concentration. The pharmacokinetics were analysed using a nonlinear mixed-effect model with an interindividual and intraindividual error model. An initial estimation was performed to determine which of the one-, two- or three-compartment models is best to describe the concentration-time data. The covariates age, gender, weight, height, lean body mass (LBM), body surface area (BSA) and body mass index (BMI) were tested for significant effects on parameters using a stepwise forward addition and backward elimination approach. Covariate effects were judged based on changes in the objective function value (OFV).

RESULTS

The pharmacokinetics of dexmedetomidine were best described by a three-compartment model. The model was further improved when height was a covariate of systemic clearance (Cl1), with a decrease in OFV by -13.56 (P<0.01). From the heights of 155-178 cm, Cl1 increased by approximately 143%. The final pharmacokinetic parameter values were as follows: V1 =63.4 l, V2=41.3 l, V3 =284.3 l, Cl1=0.47×(height/160 cm)(6.42) l/min, Cl2=2.43 l/min and Cl3=0.086 l/min.

CONCLUSIONS

This study identified (i) the effect of height on the pharmacokinetics of dexmedetomidine; (ii) that there is no influence of age, gender, weight, LBM, BSA and BMI on pharmacokinetic parameters; and (iii) it established a preliminary population pharmacokinetic model for Chinese patients.

A benefit of high temperature: increased effectiveness of a rice bacterial blight disease resistance gene

*Continuous planting of crops containing single disease resistance (R) genes imposes a strong selection for virulence in pathogen populations, often rendering the R gene ineffective. Increasing environmental temperatures may complicate R-gene-mediated disease control because high temperatures often promote disease development and reduce R gene effectiveness. Here, performance of one rice bacterial blight disease R gene was assessed in field and growth chamber studies to determine the influence of temperature on R gene effectiveness and durability. *Disease severity and virulence of Xanthomonas oryzae pv. oryzae (Xoo) populations were monitored in field plots planted to rice with and without the bacterial blight R gene Xa7 over 11 yr. The performance of Xa7 was determined in high- and low-temperature regimes in growth chambers. *Rice with Xa7 exhibited less disease than lines without Xa7 over 11 yr, even though virulence of Xoo field populations increased. Xa7 restricted disease more effectively at high than at low temperatures. Other R genes were less effective at high temperatures. *We propose that Xa7 restricts disease and Xoo population size more efficiently in high temperature cropping seasons compared with cool seasons creating fluctuating selection, thereby positively impacting durability of Xa7.

JWA regulates melanoma metastasis by integrin alphaVbeta3 signaling

JWA, a newly identified novel microtubule-associated protein (MAP), was recently demonstrated to be indispensable for the rearrangement of actin cytoskeleton and activation of MAPK cascades induced by arsenic trioxide (As(2)O(3)) and phorbol ester (PMA). JWA depletion blocked the inhibitory effect of As(2)O(3) on HeLa cell migration, but enhanced cell migration after PMA treatment. As cancer cell migration is a hallmark of tumor metastasis and the functional role of JWA in cancer metastasis is not understood, here we show that JWA has an important role in melanoma metastasis. Our data demonstrated that JWA knockdown increased the adhesion and invasion abilities of melanoma cells. Furthermore, JWA knockdown in B16-F10 and A375 melanoma cells significantly promoted the formation and growth of metastatic colonies in vivo. Moreover, in the tumor biopsies from human melanoma patients, JWA expression was significantly decreased in malignant melanoma compared with normal nevi. In addition, we found that JWA knockdown could intensify tumor integrin alpha(V)beta(3) signaling by regulating nuclear factor Sp1. These findings suggest that JWA suppresses melanoma metastasis and may serve a potential therapeutic target for human melanoma.

PTPN22 allele polymorphisms in 15 Chinese populations

Protein tyrosine phosphatase non-receptor 22 (PTPN22) is involved in the negative regulation of T-cell responsiveness. Recently, it has been reported that a single nucleotide polymorphism (SNP), C1858T, in the gene PTPN22, encoding Arg620Trp in the lymphoid protein tyrosine phosphatase (LYP), is associated with an increased risk of a number of autoimmune diseases. To study the mutant frequency and polymorphism of PTPN22 in Chinese populations, 1085 individuals from 15 Chinese populations distributing widely from north to south were collected. The genotypes of PTPN22-C1858T were determined by polymerase chain reaction-restriction fragment length polymorphism with the digestion of restriction endonuclease RsaI. Of the 1085 individuals, 31 of whom were heterozygote (PTPN22-1858C/T), the frequency of PTPN22-1858T allele in those tested individuals was 1.43%. Moreover, the frequencies of PTPN22-1858T had significant variance in 15 populations of China (chi(2) = 74.1650, P < 0.01).

The obstetric and neonatal performance of teenage mothers in an Australian community

A cohort of 7191 single births in Liverpool Hospital, New South Wales was studied to examine whether an association between young age and adverse obstetric and neonatal outcomes can be supported, and what factors if any could be related to poor outcomes. Women were classified into four groups according to their confinement age, under the age of 18 years, between 18 and 19 years, between 20 and 34 years and 35 years or over. Teenage mothers in this community, especially under the age of 18 years, were very much disadvantaged in terms of socioeconomic status. The overall obstetric performance of teenage mothers was comparable with that of adult mothers. The neonatal outcomes were found to be poor in some aspects. However, the reasons for the adverse neonatal outcomes among teenagers are not due to the young age itself, but other contributing factors, such as maternal smoking, parity, and unmarried status.

Characterisation of fibronectin-mediated FAK signalling pathways in lung cancer cell migration and invasion

Background:

Focal adhesion kinase (FAK) is overexpressed in a variety of cancers, such as breast, colon, prostate, ovary, and lung cancers. However, the mechanism by which extracellular matrix fibronectin stimulates lung cancer cell migration and invasion through FAK remains to be investigated.

Methods:

The signalling pathways in fibronectin-mediated lung cancer cell migration and invasion were examined using western blotting. The metastasis function was detected by wound healing, migration and invasion assays. Further, RNA interference and kinase inhibitors were also used to study the downstream signals.

Results:

In this study, we examined the FAK signalling pathways in relation to calpain-2 and RhoA in fibronectin-mediated lung cancer cell migration and invasion. We found that A549 lung epithelial cells stimulated by fibronectin showed increased phosphorylation of FAK and its downstream targets, Src, ERK1/2, phosphatidylinositol 3′-kinase (PI3K), and Akt. Consistent with this observation, depletion of FAK by siRNA resulted in the inhibition of Src, ERK1/2, PI3K, and Akt activity. In addition, the Src inhibitor, PP2, blocked the phosphorylation of FAK, ERK1/2, PI3K, and Akt. Conversely, inhibition of MEK1/2 using PD98059 reduced the expression of matrix metalloproteinase-9 (MMP9) and calpain-2. The PI3K inhibitor, LY294002, further blocked the expression of MMP9 and RhoA. Inhibition of both MEK1/2 and PI3K caused reduced cell migration and invasion.

Conclusion:

Our data suggest that fibronectin-mediated activation of FAK that leads to lung cancer metastasis could occur through ERK or PI3K/Akt regulation of MMP9/calpain-2 or MMP9/RhoA activity, respectively.

Association of MIF promoter polymorphisms with childhood asthma in a northeastern Chinese population

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays an important role in pathogenesis of asthma. A high level of MIF has been detected in bronchoalveolar lavage fluid, serum and sputum in asthma. Polymorphisms associated with inflammatory diseases exist in the promoter region of MIF, which alter its expression. The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and childhood asthma in a northeastern Chinese population. The study consisted of a set of 41 trios and an independent sample set of 189 childhood asthma patients and 261 healthy controls. We genotyped MIF-173G/C using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Additionally, MIF-794CATT(5-8) microsatellite polymorphism was genotyped by polyacrylamide gel electrophoresis (PAGE). A statistically significant difference in the distribution of the MIF-173C allele between patients and controls [P = 0.01, odds ratio (OR) = 1.55, 95% confidence interval (CI) = 1.13-2.18] was observed. In addition, the frequency of the MIF-173CC genotype was higher in asthmatic children (P < 0.01, OR = 3.37, 95% CI = 1.27-8.93). No difference in the distribution of CATT(5-8) was found between patients and healthy controls. Haplotype analysis showed that only the MIFCATT(7)-173C haplotype was associated with greater susceptibility to childhood asthma (P = 0.03, OR = 1.54, 95% CI 1.03-2.28). However, the transmission disequilibrium test confirmed a positive association between MIF-173G/C and childhood asthma (P = 0.005), and the absence of an association between the MIF-794CATT(5-8) and the disease. These preliminary results suggest an association between the MIF-173C allele and childhood asthma.

Effect of DNA methylation on protein-DNA interaction of HL-60 cells

HL-60 cells have been induced with differentiation index 16% by S-adenosyl-L-methionine (SAM) as inducer in the presence of optimum concentration of 10 pmol/L. The methylation level of genome DNA determined by HPLC is increased during cell differentiation. When restriction endonucleaseHae III,Sma I,Sal I,XhoI andHind III which are sensitive to 5-methyicytoside were used to cleave the genome DNA, a resistance effect was found. The interaction between DNA and DNA binding proteins is changed by using gel retarding test.

The effects of the spatial influence function on orthotropic femur remodelling

The morphology and internal structure of bone are modulated by the mechanical stimulus. The osteocytes can sense the stimulus signals from the adjacent regions and respond to them through bone growth or bone absorption. This mechanism can be modelled as the spatial influence function (SIF) in bone adaptation algorithm. In this paper, the remodelling process was simulated in human femurs using an adaptation algorithm with and without SIF, and the trabecular bone was assumed to be orthotropic. A different influence radius and weighting factor were adopted to study the effects of the SIF on the bone density distribution and trabecular alignment. The results have shown that the mean density and L—T ratio (the ratio of longitudinal modulus to transverse modulus) had an excellent linear relationship with the weighting factor when the influence radius was small. The characteristics of density distribution and L—T ratio accorded with the actual observation or measurement when a small weighting factor was used. The large influence radius and weighting factor led to unrealistic results. In contrast, the SIF hardly affected the trabecular alignment, as the mean variation angles of principal axes were less than 1.0 degree for any influence radius and weighting factor

Effect of 2-mercaptoethanol and cysteine supplementation during in vitro maturation on the developmental competence of oocytes from hormone-stimulated lambs

The objective was to determine the effect of 2-mercaptoethanol and cysteine on in vitro developmental competence of oocytes from lambs (4-8-week old) stimulated with eCG and pFSH. Oocytes were matured in medium (TCM199) with no supplement (Control group) or with 100 microM 2-mercaptoethanol and 600 microM cysteine (GSH group). Oocytes from adult sheep were also included (Adult group). The addition of 2-mercaptoethanol and cysteine did not improve nuclear maturation or microtubule configuration 12, 15, 18, or 24 h after placement in maturation medium. Sperm head decondensation and male pronucleus formation were evaluated at 6, 12, and 18 h after commencement of IVF; sperm decondensation appeared earlier in the GSH group (6h after the start of IVF). There were differences (P<0.05) between the Control group and the GSH and Adult groups for: fertilization rate at both 12 h (55.4, 77.0, and 80.6%, respectively) and 18 h (67.9, 86.9, and 88.7%); parthenogenesis rate at both 12 h (25.0, 10.8, and 5.6%) and 18 h (28.3, 9.8, and 4.5%); and polyspermy rate at 18 h (26.4, 4.9, and 5.7%). Blastocyst rate at 7d was higher in the GSH group than the Control group (23.9% vs. 14.9%, P<0.05), but both were lower (P<0.05) than the Adult group (38.3%). The addition of 2-mercaptoethanol and cysteine improved sperm decondensation and rates of fertilization and the blastocyst development to 7d, with no effect on blastocyst rate at 9 d.

Human Gastric Adenocarcinoma Allelotype on Chromosomes 17 and 18

Allelic losses of multiple chromosome loci in gastric adenocarcinoma suggest that inactivation of tumour suppressor genes in these regions may be important for tumourigenesis. To define deletion intervals and find candidate tumour suppressor genes involved in gastric adenocarcinoma pathogenesis, a genome-wide search for loss of heterozygosity (LOH) was conducted in 45 patients with primary gastric adenocarcinoma. Investigations using 29 microsatellite markers spanning chromosomes 17 and 18 showed allelic deletion in 29 (64%) specimens at one or more loci. Five LOH overlap regions, three newly identified as deletion regions, were defined: RI, D17S831–D17S921 at 17p12-13.3; RII, D17S1868–D17S787 at 17q21.3-22; RIII, D17S785–D17S928 at 17q25.3; RIV, D18S61–D18S1161 at 18q22; and RV, D18S462–D18S70 at 18q22-q23. Eleven (24%) patients with chromosome 17 allelic loss also showed LOH on 18q, with at least one region of overlapping. LOH mapping showed allelic losses were widespread on both chromosomes and suggests the possibility that multiple tumour suppressor genes, including one or more that are unknown, might be inactivated in the aetiology of gastric adenocarcinoma.

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.

Gene expression patterns in near isogenic lines for wheat rust resistance gene lr34/yr18

ABSTRACT The Lr34/Yr18 resistance gene provides durable, adult-plant, slow rusting resistance to leaf rust, yellow rust, and several other diseases of wheat. Flag leaves may exhibit spontaneous leaf tip necrosis and tips are more resistant than leaf bases. Despite the importance of this gene, the mechanism of resistance is unknown. Patterns of expression for 55,052 transcripts were examined by microarray analysis in mock-inoculated flag leaves of two pairs of wheat near isogenic lines for Lr34/Yr18 (Jupateco 73S/Jupateco 73R and Thatcher/Thatcher-Lr34). The Thatcher isolines were also examined for patterns of expression after inoculation with leaf rust. Mock-inoculated leaf tips of resistant plants showed up-regulation of 57 transcripts generally associated with ABA inducibility, osmotic stress, cold stress, and/or seed maturation. Several transcripts may be useful as expression markers for Lr34/Yr18. Five transcripts were also up-regulated in resistant leaf bases. The possible role of these transcripts in resistance is discussed. In mock-inoculated plants, pathogenesis-related (PR) proteins were not up-regulated in resistant flag leaves compared with that in susceptible flag leaves. In inoculated plants, the same set of PR proteins was up-regulated in both resistant and susceptible flag leaves. However, expression was often higher in resistant plants, suggesting a possible role for Lr34/Yr18 in priming of defense responses.