Cellular distribution of tumour suppressor protein p53 and high-risk human papillomavirus (HPV)-18 E6 fusion protein in wild-type p53 cell lines

Human papillomaviruses (HPVs) are very important pathogens that can be classified as high- and low-risk types based on the lesions they cause. Mucosal high-risk HPV E6 can target and degrade the tumour suppressor p53, hence it is recognized as the major cause of cervical cancer, however, due to a lack of reliable anti-E6 antibodies, the distribution of high-risk HPV E6 protein remains elusive. The present study, therefore, used a mammalian green fluorescent protein (GFP) expression system to express GFP-18 E6 fusion proteins in wild-type p53 cells, SMMC-7721 and HCT116, in order to trace the location and expression of HPV E6 and p53 protein. Following transfection, expression of GFP-18 E6 was found to be located in the nucleus, and endogenous wild-type p53 was also located there with GFP-18 E6.

Association between nucleotide excision repair gene polymorphisms and chromosomal damage in coke-oven workers

The associations between several genetic polymorphisms of nucleotide excision repair genes (NER) and chromosome damage level were studied among 140 coke-oven workers exposed to a high level of polyaromatic hydrocarbons (PAHs) and 66 non-exposed workers. Seven polymorphisms with functional potential in five NER genes (ERCC1, ERCC2, ERCC4, ERCC5 and ERCC6) were genotyped in the 206 study subjects. Multivariate analysis of covariance revealed that coke-oven workers with the ERCC1 19007 CC genotype had significantly higher cytokinesis-block micronucleus frequency (CBMN) (10.5 +/- 6.8 per thousand) than those with CT (8.1 +/- 6.6 per thousand, p = 0.01) or TT (6.6 +/- 3.7-/ per thousand p = 0.05) or CT+TT genotypes (7.5 +/- 6.3 per thousand, p = 0.004). The ERCC6 A3368G polymorphism was also associated with CBMN frequency among coke-oven workers. Subjects with the AA genotype have a significantly higher CBMN frequency (10.0 +/- 6.9 per thousand) than those with AG (6.7 +/- 4.2 per thousand, p = 0.05) or AG+GG genotypes (6.6 +/- 4.1 per thousand, p = 0.02). Stratification analysis revealed the significant associations between ERCC1 C19007T and ERCC6 A3368G, and the CBMN frequencies were only found among older workers. In addition, a significant association between ERCC2 G23591A polymorphism and CBMN frequencies was also found among older coke-oven workers. The results suggest that polymorphisms of ERCC1 C19007T, ERCC6 A3368G and ERCC2 G23591A are associated with the CBMN frequencies among coke-oven workers.

Beam loading in the nonlinear regime of plasma-based acceleration

A theory that describes how to load negative charge into a nonlinear, three-dimensional plasma wakefield is presented. In this regime, a laser or an electron beam blows out the plasma electrons and creates a nearly spherical ion channel, which is modified by the presence of the beam load. Analytical solutions for the fields and the shape of the ion channel are derived. It is shown that very high beam-loading efficiency can be achieved, while the energy spread of the bunch is conserved. The theoretical results are verified with the particle-in-cell code OSIRIS.

Predicting atrazine levels in water utility intake water for MCL compliance

To protect human health, atrazine concentrations in finished municipal drinking water must not exceed a maximum contaminant level (MCL) of 3 microg/L, as determined by a specific monitoring regime mandated by the United States Environmental Protection Agency. Atrazine levels were monitored along tile-fed drainage ditches draining to a major drinking water source and used to predict MCL exceedance frequencies of intake and finished drinking water. Water samples were collected daily at eight monitoring sites located at the outlets of subbasins draining 298-19 341 ha (736-47 794 ac). Flow-weighted average (FWA) atrazine concentrations ranged from 0.9 to 9.8 microg/L, and were above 3 microg/L for the majority of sites, including the largest site, which represents water quality at the intake of the local municipal water treatment plant. However, a relatively low percentage of samples near the water utility intake exceeding 3 microg/L atrazine (10.4%) made this problem difficult to detect. In order to have a 95% probability of detecting any intake sample exceeding 3 microg/L atrazine in a drainage system exceeding 3 microg/L atrazine on a FWA basis, sampling frequency would need to be every 7 days or more often during the second quarter when the potentials for field atrazine losses and temporal variability of atrazine concentrations are highest.

Halo formation and emittance growth of positron beams in plasmas

An ultrarelativistic 28.5 GeV, 700-microm-long positron bunch is focused near the entrance of a 1.4-m-long plasma with a density n(e) between approximately equal to 10(13) and approximately equal to 5 x 10(14) cm(-3). Partial neutralization of the bunch space charge by the mobile plasma electrons results in a reduction in transverse size by a factor of approximately equal to 3 in the high emittance plane of the beam approximately equal to 1 m downstream from the plasma exit. As n(e) increases, the formation of a beam halo containing approximately 40% of the total charge is observed, indicating that the plasma focusing force is nonlinear. Numerical simulations confirm these observations. The bunch with an incoming transverse size ratio of approximately 3 and emittance ratio of approximately 5 suffers emittance growth and exits the plasma with approximately equal sizes and emittances.

Development of recombinant adeno-associated virus and adenovirus cocktail system for efficient hTERTC27 polypeptide-mediated cancer gene therapy

The low in vivo transduction efficiency of recombinant adeno-associated virus (rAAV) and the undesirably strong immunogenicity of adenovirus (rAdv) have limited their clinical utilization in cancer gene therapy. We have previously demonstrated that intratumoral injection of rAAV expressing a C-terminal polypeptide of human telomerase reverse transcriptase (rAAV-hTERTC27) effectively inhibits the growth of glioblastoma xenografts in nude mice. To further improve its efficacy, we combined rAAV-hTERTC27 with rAdv and investigated the efficiency of the cocktail vectors in vivo. At a nontherapeutic dose (1 x 10(8) plaque-forming units (PFUs)), rAdv-null and rAdv-hTERTC27 were equipotent in enhancing the therapeutic efficacy of rAAV-hTERTC27 (1.5 x 10(11) v.g.), and complete tumor regression was achieved in 25% of the treated animals. Importantly, the combination of rAAV-hTERTC27 and a therapeutic dose (2.5 x 10(9) PFU) of rAdv-hTERTC27 significantly augmented the therapeutic effects and led to a 38% complete tumor regression rate. In vivo optical imaging also showed that rAAV-luc/rAdv-luc cocktail vectors could synergistically enhance the early transient and latent sustained expression of luciferase, as compared to rAdv-luc and rAAV-luc alone. These findings suggest that the combination of rAAV-hTERTC27 and a therapeutic dose of rAdv-hTERTC27 is potentially a promising treatment for glioblastoma, and the rAAV/rAdv cocktail vector system warrants further development for cancer gene therapy.

Effect of amiodarone on Kv1.4 channel C-type inactivation: comparison of its effects with those induced by propafenone and verapamil

As the major component of I(to) (slow), Kv1.4 channel plays an important role in repolarization of cardiac myocytes. C-type inactivation is one of Kv1.4 inactivation and can be affected by open channel blockers. We used the two-electrode voltage clamp technique to observe the effect of amiodarone on Kv1.4 C-type inactivation and compare amiodarone's effects on Kv1.4 with propafenone and verapamil. Our data show that those three antiarrhythmic drugs blocked fKv1.4 delta N (N-terminal deleted Kv1.4 channel from ferret heart) in voltage- and frequent-dependent manners. The amiodarone's IC50 was 489.23 +/- 4.72 microM, higher than that of propafenone (98.97 +/- 1.13 microM) and verapamil (263.26 +/- 6.89 microM) for fKv1.4 delta N channel (+50 mV). After application of amiodarone, propafenone and verapamil, fKv1.4 delta N inactivation becomes bi-exponential: the faster portion of inactivation (drug-induced inactivation) and the slower portion of inactivation (C-type inactivation). Amiodarone and verapamil fastened C-type inactivation in fKv1.4 delta N, but propafenone did not. Unlike propafenone that had no effect on fKv1.4 delta N recovery, amiodarone and verapamil slowed recovery in fKv1.4 delta N.

Effect of pre-freezing conditions on semen cryopreservation in rhesus monkeys

Although sperm cryopreservation has been studied in at least 17 non-human primate species, systematic factor optimization for any single species is lacking. Gene banking of non-human primate sperm is still in its infancy. The objective of the present study was to initiate a systematic approach to optimize the process of sperm cryopreservation for rhesus macaques, specifically, factors related to pre-freezing conditions (e.g., straw freezing position, sperm concentration, sperm washing, equilibration methods, and equilibration time periods). Straw position had no effect on post-thaw motility (P=0.193). Sperm concentration was tested in a range from 5 x 10(6)mL(-1) to 5 x 10(8)mL(-1); post-thaw motility of sperm samples frozen at 5 x 10(7)cell mL(-1) (51.0+/-10.6%; mean+/-S.D.) and 5 x 10(8)cell mL(-1) (48.1+/-7.3%) were higher than samples frozen at 5 x 10(6)cells mL(-1) (33.0+/-12.0%, P=0.003). Comparison of motility immediately after thawing between samples with (51.2+/-6.2%) and without washing (53.9+/-6.8%) revealed no differences (P>0.05). However, washing improved sperm forward progression within 1h after thawing, whereas unwashed sperm retained higher post-thaw motility and progression during extended incubation (4h) after thawing (P<0.05). Equilibration methods (with or without pre-cooling) made no difference on post-thaw motility (P>0.05), and the most effective equilibration time was the duration required for samples to acclimate to 4 degrees C prior to freezing. Evaluation and optimization of these pre-freezing conditions will help to minimize sources of injury, maximize survival, and contribute to the development of an optimized cryopreservation protocol for rhesus macaque sperm.

Metabolic abnormalities associated with mild cognitive impairment in Parkinson disease

OBJECTIVE

To use (18)F-fluorodeoxyglucose (FDG) and PET to investigate changes in regional metabolism associated with mild cognitive impairment (MCI) in Parkinson disease (PD). Cognitive abnormalities are common in PD. However, little is known about the functional abnormalities that underlie the manifestations of MCI in this disorder.

METHODS

We used FDG PET to measure regional glucose metabolism in patients with PD with multiple-domain MCI (MD-MCI; n = 18), with single-domain MCI (SD-MCI; n = 15), and without MCI (N-MCI; n = 18). These patients were matched for age, education, disease duration, and motor disability. Maps of regional metabolism in the three groups were compared using statistical parametric mapping (SPM). We also computed the expression of a previously validated cognition-related spatial covariance pattern (PDCP) in the patient groups and in an age-matched healthy control cohort (n = 15). PDCP expression was compared across groups using analysis of variance.

RESULTS

SPM revealed decreased prefrontal and parietal metabolism (p < 0.001) in MD-MCI relative to N-MCI, as well as an increase in brainstem/cerebellar metabolism (p < 0.001) in this group. In these regions, SD-MCI occupied an intermediate position between the two other groups. PDCP expression was abnormally elevated in the N-, SD-, and MD-MCI groups (p < 0.05), increasing stepwise with worsening cognitive impairment (p < 0.01).

CONCLUSIONS

Early cognitive decline in Parkinson disease as defined by mild cognitive impairment is associated with discrete regional changes and abnormal metabolic network activity. The quantification of these alterations with (18)F-fluorodeoxyglucose PET may allow for the objective assessment of the progression and treatment of this disease manifestation.

Far-field imaging of the electromagnetic local density of optical states

We introduce a new experimental method to measure the local electromagnetic density of states (LDOS) by integrating the differential scattering cross section. The signal detected essentially reflects the intrinsic scattering response of the photonic structures and renders the partial LDOS dominated by evanescent modes. We give a theoretical understanding of the LDOS image formation and show a qualitative agreement between experimental images and theoretical maps. This approach can be practically applied to the direct measurement of an optical antenna's scattering efficiency and can provide valuable information for designing optimum structures utilized in radiative decay engineering.

Microtia: ear reconstruction using tissue expander and autogenous costal cartilage

Ear reconstruction is one of the most challenging surgeries faced by the reconstructive surgeon. Currently, the use of autogenous costal cartilage is still best practice for microtia reconstruction. However, the relative deficiency of thin skin for coverage of the cartilage framework remains a limiting factor. Since 1994, we have used tissue expander in the mastoid area and innovated a technique to fabricate cartilage framework. All these innovations may solve the deficiency of the skin and improve cartilaginous framework definition. In conclusion, tissue expander offers a non-hairbearing, thin, well-vascularised skin to envelope an erect, contour-accentuated framework. Most patients with microtia are satisfied with their ear reconstruction.

CNTO 530: molecular pharmacology in human UT-7EPO cells and pharmacokinetics and pharmacodynamics in mice

CNTO 530 is a 58 kD antibody Fc domain fusion protein, created using Centocor's MIMETIBODY platform, that contains two EMP1 sequences as a pharmacophore. CNTO 530 has no sequence homology with EPO but acts as a novel erythropoietin receptor agonist. In UT-7(EPO) cells, CNTO 530 caused protein phosporylation of the erythropoietin receptor associated signaling pathway (Jak2, STAT5, AKT and ERK1/2). CNTO 530 also rescued these cells from apoptosis and mediated proliferation. In mice, pharmacokinetic analysis showed that CNTO 530 was slowly cleared from circulation with a t(1/2) approximately 40 h. Pharmacodynamic analysis in mice showed that a single sc dose of CNTO 530 caused a long-lived stimulation of erythropoiesis that translated into increases in red blood cell counts and hemoglobin values that were maintained for at least 28 d. In conclusion, CNTO 530 is a long-lived EPO-R agonist that stimulates erythropoiesis in a manner similar to epoetin-alpha. These data suggest that CNTO 530 may be an effective treatment of anemia in humans.

Hosing instability in the blow-out regime for plasma-wakefield acceleration

The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al. [in Phys. Rev. Lett. 96, 165002 (2006)10.1103/PhysRevLett.96.165002]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al. [Phys. Rev. Lett. 67, 991 (1991)10.1103/PhysRevLett.67.991] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.