Improved immunogenicity of recombinant Mycobacterium bovis bacillus Calmette-Guérin strains expressing fusion protein Ag85A-ESAT-6 of Mycobacterium tuberculosis

Early secretory antigen target 6 (ESAT-6) is a dominant target for cell-mediated immunity in the early phase of tuberculosis (TB) in patients with TB, causing T-cell proliferation and gamma interferon (IFN-γ) production, which has been considered to be a protective antigen that can be used for future vaccine development. Ag85A is the most essential component for bacterial survival within macrophages and has been used in numerous vaccine preparations, which can induce strong cellular immune responses. In this study, we constructed a new recombinant bacilli Calmette-Guérin (BCG) strain (rBCG-AE) that could express fusion protein Ag85A-ESAT-6 of Mycobacterium tuberculosis and evaluated its immunogenicity in BALB/c mice. There was no evidence for increased virulence of this rBCG. Our experiments illustrated that the rBCG-AE was able to induce higher titer of antibody and elicit more long-lasting and stronger Th1 type cellular immune responses than the parental BCG strain, or rBCG-A (expressing Ag85A) strain, or rBCG-E (expressing ESAT-6) strain, which are characterized by the strong antibody response, the proliferation rate of splenocytes, the ratio of CD4(+) T and CD8(+) T cells stimulated by tuberculin-purified protein derivative and elevated levels of IFN-γ in antigen-stimulated splenocyte cultures. The results show that rBCG-AE is an improved TB vaccine for further study.

Concomitant increases in spectrum and level of drug resistance in Mycobacterium tuberculosis isolates

OBJECTIVE

To determine the drug resistance spectrum and resistance levels of extensively drug-resistant (XDR-) and multidrug-resistant tuberculosis (MDR-TB) and TB resistant to either rifampicin (RMP, R) or isoniazid (INH, H; R/H-DR).

DESIGN

Of 142 drug-resistant clinical isolates examined, 13 were XDR-TB, 66 were MDR-TB and 63 were R/H-DR. The drug resistance spectrum was tested by the absolute two-concentration method. Minimum inhibitory concentrations (MICs) were determined for the strains by agar dilution method on Löwenstein-Jensen slants.

RESULTS

The drug resistance spectrum of XDR-TB, MDR-TB and R/H-DR TB isolates ranged from 4 to 9, 2 to 6 and 1 to 5 drugs, respectively. Over half of all XDR-TB (53.8%), MDR-TB (66.7%) and R/H-DR (54.0%) isolates were resistant to two other anti-tuberculosis drugs; 38.5% of XDR-TB, 24.2% of MDR-TB and 28.6% of R/H-DR TB isolates were resistant to ≥ 3 additional anti-tuberculosis drugs in addition to those originally defined, demonstrating that the MIC values and the proportions of strains with higher MICs followed a trend of XDR-TB > MDR-TB > R/H-DR for INH, RMP, ofloxacin and ethambutol.

CONCLUSION

XDR-TB, MDR-TB and R/H-DR TB isolates exhibited both increasingly broader resistance spectra and a higher percentage of strains with high MICs to more frequently resistant drugs, which might be related to patterns of TB chemotherapy.

The Effect of Platelet-rich Plasma with Mineralized Collagen-based Scaffold on Mandible Defect Repair in Rabbits

The effect of platelet-rich plasma (PRP) on a porous scaffold of nano-hydroxyapatite/collagen/poly(lactic-acid) (nHAC/PLA) to repair a mandible defect in a rabbit model was evaluated. A 10 × 8 mm2 perforated defect roughly 5 mm thick was made in the right mandible of each animal, preserving the periosteum in situ. The defects were treated using nHAC/PLA grafts with or without autologous PRP. The results of X-ray, dual energy X-ray measurements of bone mineral density, scanning electron microscopy, histology, and newly formed bony area evaluated by ANOVA showed that PRP significantly shorten recovery time and accelerate defect repair, especially in the first month. The incorporation of PRP appears to be an effective approach for improving bone repair.

Low-energy (<10 meV) feature in the nodal electron self-energy and strong temperature dependence of the Fermi velocity in Bi{2}Sr{2}CaCu{2}O{8+δ}

Using low photon energy angle-resolved photoemission, we study the low-energy dispersion along the nodal (π,π) direction in Bi{2}Sr{2}CaCu{2}O{8+δ} as a function of temperature. Less than 10 meV below the Fermi energy, the high-resolution data reveal a novel "kinklike" feature in the electron self-energy that is distinct from the larger well-known kink roughly 70 meV below E{F}. This new kink is strongest below the superconducting critical temperature and weakens substantially at higher temperatures. A corollary of this finding is that the Fermi velocity v{F}, as measured in this low-energy range, varies rapidly with temperature-increasing by almost 30% from 70 to 110 K. The behavior of v{F}(T) appears to shift as a function of doping, suggesting a departure from simple "universality" in the nodal Fermi velocity of cuprates.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Sun-induced changes in stratum corneum function are gender and dose dependent in a Chinese population

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18-50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure.

Risk of progression to hypertension in a rural Chinese women population with prehypertension and normal blood pressure

BACKGROUND

To determine the incidence of hypertension and its risk factors among rural Chinese women with prehypertension and normotension.

METHODS

A population-based sample of 12,060 rural Chinese women aged > or = 35 years and free from hypertension at baseline were followed from 2004-2006 to 2008. Incident hypertension was defined as systolic blood pressure (SBP) > or = 140 mm Hg, diastolic blood pressure (DBP) > or = 90 mm Hg, or current use of antihypertensive medication.

RESULTS

Over a median follow-up of 28 months (range, 14-47 months), 23.4% of women developed hypertension. The age-adjusted incidence rate was higher in prehypertension than in normotension (11.2/100 person-years vs. 7.9/100 person-years, P < 0.05). Among women with prehypertension, independent predictors of incident hypertension were baseline age, Mongolian ethnicity, low physical activity, baseline body mass index (BMI), baseline salt intake and family history of hypertension. Among women with normal blood pressure (BP), independent predictors were baseline age, low physical activity, baseline BMI and baseline salt intake. The awareness, treatment, and control rates for newly developed hypertension were 33.2, 23.0, and 2.1%, respectively.

CONCLUSIONS

These data indicate that the incidence of hypertension is high among rural Chinese women and it is associated with many risk factors, and the data also suggest that most newly developed hypertension cases are not treated. This high incidence of hypertension may be related to rapid social changes in our country and may apply to other areas of the developing world. These results call for urgent improvements in hypertension prevention, detection and treatment.

Is utilisation of computed tomography justified in clinical practice? Part IV: applications of paediatric computed tomography

Computed tomography (CT) has been recognised as the most widely used imaging technique in both adults and children, owing to technological developments, especially with the recent innovations in multislice CT. This has resulted in an increase in the use of CT examinations in children younger than 15 years of age in developed countries. The increasing use of paediatric CT in clinical practice has raised concerns regarding the potential risk of radiation-induced malignancy. This is because CT examinations deliver a much higher radiation dose than conventional radiographic techniques. Children are more sensitive to radiation exposure than adults and have a longer time ahead of them to manifest radiation-induced effects and injuries. Therefore, it is of paramount importance to reduce or minimise the radiation dose to children when choosing CT as the major imaging modality for diagnostic purposes. This article reviews the clinical applications of paediatric CT with regard to the adjustment of imaging protocols in routine clinical practice and in the emergency department, the justification of CT use in paediatric imaging, clinical awareness of CT-associated radiation risk and strategies to minimise radiation exposure to children.

Genetic variation in glutathione metabolism and DNA repair genes predicts survival of small-cell lung cancer patients

BACKGROUND

Small-cell lung cancer (SCLC) carries the worst prognosis among lung cancer diagnoses. Combined radiation and chemotherapy is the standard of care; however, treatment outcomes vary. Variability in the rate at which chemotherapy agents are metabolized and in the capacity of repairing DNA damage has been hypothesized to be partly responsible for the treatment response variation. Genes in the glutathione metabolism and DNA repair pathways were tested through tag single-nucleotide polymorphisms (SNPs) to assess their association with survival in SCLC.

PATIENTS AND METHODS

Blood DNA from 248 patients with primary SCLC was genotyped for 419 tag SNPs from 49 genes in the glutathione and DNA repair pathways. Association analyses with patient survival were carried out at single-SNP, whole-gene, and haplotype levels after adjusting for age, gender, tumor stage, treatment modalities, and smoking history.

RESULTS

Among the 375 SNPs successfully genotyped, 21 SNPs, located on 11 genes, showed significant association with survival. Whole-gene analyses confirmed 3 of the 11 genes: GSS, ABCC2, and XRCC1. Haplotype analyses of these three genes identified haplotype combinations and genomic locations underlying the observed SNP associations.

CONCLUSION

Genetic variations in genes involved in the glutathione and DNA repair pathways are associated with SCLC survival.

Multislice CT angiography in cardiac imaging. Part III: radiation risk and dose reduction

With the introduction of 64- or more-slice computed tomography (CT) technology, multislice CT angiography has been increasingly used as a non-invasive modality for the diagnosis of coronary artery disease. Despite its potential advantages and promising clinical results, multislice CT angiography suffers from high radiation dose which contributes to radiation-induced malignancy in patients undergoing cardiac CT examinations. This has raised serious concerns in clinical practice. A number of strategies have been recommended and implemented to reduce the radiation dose associated with multislice CT angiography in cardiac imaging. The aim of this review is to present an overview of the various approaches used for radiation dose reduction. Future directions of multislice CT angiography with regard to the judicious use of this promising technique and increased awareness of the radiation risk are highlighted.

Multislice CT angiography in cardiac imaging. Part II: clinical applications in coronary artery disease

Multislice computed tomography (CT) angiography represents a technological evolution in cardiac imaging due to improved spatial and temporal resolution. Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a viable and effective alternative to invasive coronary angiography in selected patients. Multislice CT angiography has demonstrated high sensitivity and specificity, and in particular, a very high negative predictive value, which makes it a valuable imaging modality for screening patients suspected of coronary artery disease. In addition, multislice CT angiography demonstrates accuracy in the detection and characterisation of coronary plaques, and it has been reported to play an important role in predicting disease progression and cardiac events. The aim of this review was to present an overview of the clinical applications of multislice CT angiography in coronary artery disease, with regard to its diagnostic accuracy and predictive value in coronary artery disease. Emerging areas of multislice CT, including dual-energy CT and CT myocardial perfusion, are also discussed. Limitations of multislice CT angiography and future directions of cardiac multislice CT are highlighted.

Identification of two auto-cleavage products of nonstructural protein 1 (nsp1) in porcine reproductive and respiratory syndrome virus infected cells: nsp1 function as interferon antagonist

The porcine reproductive and respiratory syndrome virus nsp1 is predicted to be auto-cleaved from the replicase polyprotein into nsp1alpha and nsp1beta subunits. In infected cells, we detected the actual existence of nsp1alpha and nsp1beta. Cleavage sites between nsp1alpha/nsp1beta and nsp1beta/nsp2 were identified by protein microsequencing analysis. Time course study showed that nsp1alpha and nsp1beta mainly localize into the cell nucleus after 10 h post infection. Further analysis revealed that both proteins dramatically inhibited IFN-beta expression. The nsp1beta was observed to significantly inhibit expression from an interferon-stimulated response element promoter after Sendai virus infection or interferon treatment. It was further determined to inhibit nuclear translocation of STAT1 in the JAK-STAT signaling pathway. These results demonstrated that nsp1beta has ability to inhibit both interferon synthesis and signaling, while nsp1alpha alone strongly inhibits interferon synthesis. These findings provide important insights into mechanisms of nsp1 in PRRSV pathogenesis and its impact in vaccine development.

Is utilisation of computed tomography justified in clinical practice? Part I: application in the emergency department

Computed tomography (CT) is currently a widely available imaging technique in clinical practice. Technical developments of CT imaging, especially the emergence of multislice CT, with increased scanning speed and volume as well as higher spatial and temporal resolution, have significantly enhanced the diagnostic value of CT in many clinical applications. CT has become an important diagnostic imaging modality in the emergency department, with high diagnostic accuracy and efficacy in both traumatic and non-traumatic conditions. There is, however, a growing concern about the risk of associated radiation exposure in the population exposed to CT examination. Justification of the application of CT is one of the main principles that physicians need to be aware of when choosing CT as the first-line technique for diagnosis. This article reviews the clinical applications of CT imaging in the emergency department, with a focus on patients presenting with headache, repeat and multiple CT imaging and whole body screening for trauma patients, and explores whether the applications are clinically justified.

Apatite reduces amelogenin proteolysis by MMP-20 and KLK4 in vitro

Two enamel proteases, matrix metalloproteinase-20 (MMP-20) and kallikrein 4 (KLK4), are known to cleave amelogenin and are necessary for proper enamel formation. However, the effect of hydroxyapatite (HAP) on the proteolytic activity of these enzymes remains unclear. To investigate whether apatite affects normal amelogenin proteolysis, we used 2 different isoforms of amelogenin combined with the appropriate enzymes to analyze proteolytic processing rates in the presence or absence of synthetic hydroxyapatite (HAP) crystals (N = 3). We found a distinct dose-dependent relationship between the amount of HAP present in the proteolysis mixture and the rate of rP172 degradation by rpMMP-20, whereas the effect of HAP on proteolysis of either rP172 or rP148 by rhKLK4 was less prominent.