Clinical trial experience with prophylactic HPV 6/11/16/18 VLP vaccine in young women from the Asia-Pacific region

OBJECTIVE

To evaluate results of three phase 3 clinical trials of quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women.

METHODS

A total of 814 women from the Asia-Pacific region (aged 16 to 26 years) received vaccine or placebo in 1 of 3 protocols. Descriptive analyses focused on the efficacy, safety, and immunogenicity of the vaccine and the natural history of HPV disease.

RESULTS

Vaccine efficacy against disease caused by HPV types 6, 11, 16, or 18 was 100% for cervical intraepithelial neoplasia (0 vs 12 cases; 95% confidence interval [CI], 63.1%-100%) and 100% for vulvar and vaginal intraepithelial neoplasia or condylomata accuminata (0 vs 5 cases; 95% CI, -11.8% to 100%). The vaccination was highly immunogenic. Vaccine recipients experienced a significantly higher injection site adverse event rate (P=0.002). Compared with other world regions, lower rates of smoking and baseline positivity to 14 HPV types (including the vaccine types) were observed among Asia-Pacific participants.

CONCLUSION

Prophylactic quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women demonstrated high efficacy, safety, and tolerability. Together with an observed low baseline HPV positivity rate, the Asia-pacific population is potentially an important cohort to benefit from vaccination.

The construction of a novel kind of non-viral gene delivery vector based on protein as core backbone

BACKGROUND AND OBJECTIVES

A novel kind of non-viral gene delivery vector based on transferrin (Tf) as the core component was constructed with high transfection efficiency and low toxicity.

MATERIALS AND METHODS

The synthesis vector of Tf-PEI600 was confirmed by different physicochemical methods, including (1)H nuclear magnetic resonance, gel permeation chromatography, X-ray and thermogravimetric analysis. The cytotoxicity and gene delivery efficiency of the synthesized vector were verified by in vitro experiments.

RESULTS

The agarose gel electrophoresis assay indicated that the novel copolymer Tf-PEI600 could efficiently condense plasmid DNA and the condensed nanoparticles exhibited a spherical shape. As the weight ratio of Tf-PEI600 to DNA reached 15.0, the particle size (about 200 nm) and the zeta potential (about 20 mV) of the nanoparticles became optimal for gene delivery. The methylthiazolyl tetrazolium (MTT) assay showed the cytotoxicity of Tf-PEI600 to be similar to that of PEI600 and much lower than that of PEI25kDa. In gene-delivery experiments with COS-7 cells and HepG2 cells, the Tf-PEI600 showed about a 30- to 53-fold higher efficiency than PEI600 and nearly equal to that of PEI25kDa.

CONCLUSIONS

These data suggest that Tf-PEI600, with the advantages of low toxicity and high gene-delivery efficiency, might have great prospects in the practice of gene delivery. The core-shell structure of Tf-PEI600 also provided a novel strategy for the construction of non-viral gene delivery vectors.

Rethinking the role of nodal status in TNM staging of node-positive breast cancer

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Background: Among TNM staging criteria, the number of positive lymph nodes [PNOD] is the strongest predictor of patient outcome. Based on SEER data, Vinh Hung (2004) asserted that the ratio of the number of positive nodes to the number of nodes removed [NODR] may better predict outcome. We evaluated this assertion in patients from 13 node-positive NSABP phase III trials. Methods: The impact of PNOD, its logarithm (LPNOD) and NODR on survival (S) and recurrence free survival (RFS) were assessed via Cox PH models in 19,768 patients with node-positive breast cancer in 13 NSABP clinical trials. The cohort was split into 2 groups: 9 older trials (Protocols B-05, B-07, B-08, B-09, B-10, B-11, B-12, B-15 and B-16) consisting of 9,915 patients and 4 newer trials (B-22, B-25, B-28 and B-31) consisting of 9,853 patients. Only randomized eligible patients with follow-up were considered. Models were fit to the outcomes for the older trials and validated in the newer trials. Results were adjusted for age, protocol and tumor size. We used Wald z-scores, Nagelkerke R2, and residual analyses to assess the strength of the relationship between nodal status and outcomes. Results: Median time on study was 19.8 years in the older trials and 10.6 years in the newer trials. Ten-year models across the protocols revealed that the relative hazard ratio for each of the outcomes studies was logarithmic according to the number of positive nodes for = 30 positive nodes. Using LPNOD and NODR compared to PNOD improved the strength of association but did not greatly improve goodness of fit ( Table 1 1). For all endpoints, the strength of association and goodness of fit associated with nodal status and other TNM factors attenuated in newer protocols. Conclusions: Nodal status and other TNM factors currently used for breast cancer staging continue to be strong indicators of patient prognosis. However, these factors should be augmented to account for new genetic and biological markers.

[Table: see text]

No significant financial relationships to disclose.

Chemosensitivity and stratification by a five monoclonal antibody IHC test in the NSABP B20 trial

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Background: We previously reported the association between a five monoclonal antibody test staining p53, NDRG1, SLC7A5, CEACAM5 and HTF9C and recurrence-free interval (RFI) in 711 ER+ N- breast cancer patients from Tamoxifen (Tam) arm of the NSABP trials B14 and B20 (SABCS 2006). In this study, we examined interaction between the test and chemotherapy in the B20 trial. Subjects and Methods: Tissue array sections from B20 paraffin blocks were stained using standard IHC protocols (N=457). Pre-defined scoring rules and cut- points were applied. RFI was defined as time from entry to any local, regional or distant recurrence. Log-rank test was applied to assess the effect of chemotherapy for each risk stratum pre-defined by this IHC test. Interaction between risk strata and treatment was assessed by the likelihood ratio test in a Cox model with age and clinical tumor size adjusted. Results: The IHC test identified high and low risk groups that both showed significant improvement upon treatment with cytotoxic chemotherapy. The moderate risk group was poorly populated and showed no significant difference between chemo-treated and Tam-only patients. Conclusion: It appears that five monoclonal antibodies may be able to identify groups of ER+, node negative patients who have greater absolute benefit from adjuvant Chemo compared to un-stratified patient populations. However, the formal test for interaction between Chemo and the risk group was not significant (p- value=0.127). This may be due to small sample size and a lack of statistical power. The results suggest that this test deserves further evaluation as a method for identifying subsets of patients who may receive more benefit from Chemo.

[Table: see text]

No significant financial relationships to disclose.

Menstrual cycle lengths and bone mineral density: a cross-sectional, population-based study in rural Chinese women ages 30-49 years

INTRODUCTION

The menstrual cycle involves periodic fluctuations in estrogen and progesterone levels. Longer cycles have been associated with longer follicular phase, delayed estrogen peak and a lower mean oestradiol level of the entire cycle.

METHODS

We hypothesized that prolonged menstrual cycle length is associated with decreased bone mineral density (BMD) in a population of pre- and perimenopausal women. This population-based cross-sectional study was conducted in rural Anhui province, China. It includes 4,771 women, aged 30 to 49 years, who did not smoke or drink alcohol, and did not use oral contraceptives or breastfeed during the previous year. Dual-energy X-ray absorptionometry (DEXA) BMD measurements were taken at four skeletal sites: whole body, total hip, femoral neck and lumbar spine. Menstrual cycle characteristics (polymenorrhea, short normal, long normal, oligomenorrhea, 90-day amenorrhea, irregular cycle) in the prior year were assessed by questionnaire.

RESULTS

Prolonged menstrual cycle was consistently associated with decreased BMD at whole body, total hip, and femoral neck in both age 30-39, and age 40-49 stratum (p(trend)<0.05). Prolonged menstrual cycle was also associated with decreased lumbar spine BMD for women aged 40-49 (p(trend)<0.05). Among women with normal cycles aged 30-39, menstrual cycle length in the previous year was inversely associated with whole-body BMD (p<0.05). Women with 90-day amenorrhea had significantly lower mean total hip and femoral neck BMD relative to women with short normal cycles in the 30-39 age group; and had significantly lower whole body and total hip BMD relative to short normal cycles in the 40-49 age group. BMD in polymenorrheic women did not differ from BMD in women with short normal cycles at any of the skeletal sites.

CONCLUSIONS

We conclude that prolonged menstrual cycle length is associated with decreased BMD in pre- and perimenopausal women in this population.

Genetic polymorphisms of the urea transporter gene are associated with antihypertensive response to nifedipine GITS

Nifedipine GITS has diuretic and natriuretic properties, which may enhance its antihypertensive efficacy. We assessed contributions of polymorphisms in the urea transporter-A gene (SLC14A2) to interindividual variations in blood pressure (BP) response to nifedipine treatment. 405 subjects from a single Chinese county received a single oral dose of 30 mg nifedipine GITS (gastrointestinal therapeutic system) daily for 16 days. We genotyped two SNPs in SLC14A2 and found significant associations for the Val227Ile (rs1123617) and Ala357Thr (rs3745009) polymorphisms with BP response to nifedipine treatment. After treatment, subjects with either Ala357/Thr357 or Thr357/Thr357 genotypes had significantly smaller mean changes in systolic BP (SBP) (beta +/- SE = -2.87 +/- 1.24 mmHg, p = 0.020) and diastolic BP (DBP) (beta +/- SE = -1.69 +/- 0.62 mmHg, p = 0.006) compared to those with the Ala357/Ala357 genotype. Subjects with either Val227/Ile227 or Ile227/Ile227 genotypes had significantly larger mean changes in SBP (beta +/- SE = 3.13 +/- 1.19, p = 0.009) and DBP (beta +/- SE = 1.50 +/- 0.60 mmHg, p = 0.013) compared with those with the Val227/Val227 genotype after treatment. Subjects carrying both the Ala357/Ala357 genotype in the Ala357Thr polymorphism and either Val227/Ile227 or Ile227/Ile227 genotypes in the Val227Ile polymorphism had the highest mean change in SBP and DBP. Our study supports the conclusion that polymorphisms in the SLC14A2 gene can predict the antihypertensive efficacy of nifedipine GITS.

Comparison of microshear bond strengths of four self-etching bonding systems to enamel using two test methods

BACKGROUND

Recent advances in enamel and dentine adhesive technology have resulted in the emergence of many new adhesive systems. Self-etching bonding systems do not require a separate etching step and the newest systems are the "all-in-one" systems which combine etching, priming and bonding into a single application. This study reports laboratory enamel microshear bond strengths of a self-etching priming and three all-in-one systems and also evaluates two different microshear bond test methods.

METHODS

One hundred and nineteen enamel specimens were bonded (0.8 mm diameter) with either Clearfil Protect Bond (Kuraray), Xeno III (Dentsply), G Bond (GC) or One-Up Bond F (Tokuyama) using Palfique Estelite resin composite and stored in 37 degrees Celsius water for seven days. The microshear bond test method used either a blade or wire to apply the shear stress. Results were analysed with one-way ANOVA and post hoc (Tukey) multiple comparison analysis.

RESULTS

Clearfil Protect Bond demonstrated higher and more consistent bond strengths than Xeno III, G Bond or One-Up Bond F. The wire method showed much greater reliability in results, with a coefficient of variation half that of the blade method.

CONCLUSIONS

All-in-one adhesives seem to be less reliable than the two-step self-etching priming adhesive when bonding to enamel. Test method can significantly affect results in the microshear bond test method.

CYP2C9 Ile359Leu polymorphism, plasma irbesartan concentration and acute blood pressure reductions in response to irbesartan treatment in Chinese hypertensive patients

Our previous study demonstrated that the CYP2C9*3 gene variant was significantly associated with elevated plasma irbesartan concentration and blood pressure decline, assessed by a 4-week follow-up and revisit following daily administration of irbesartan. We conducted a further analysis to examine the acute effects of the CYP2C9 polymorphism on plasma concentration and blood pressure through remeasurement 6 h after administration of irbesartan. We used an extreme-sampling approach by selecting individuals from the top and bottom deciles of blood pressure response residuals to irbesartan from the previous study population in Anhui, Taihu, and Dongzhi Counties, in China. A total of 196 subjects were available for the analysis. Pre- and posttreatment systolic and diastolic blood pressures (SBP and DBP), and venous blood samples (0.5, 2, and 6 h following the first treatment) were collected from each individual. Plasma irbesartan concentrations were determined by a standard HPLC/fluorescence method. The observed frequencies were 97.7% for CYP2C9*1 (Ile359) and 2.3% for CYP2C9*3 (Leu359). Subjects with the CYP2C9*1/CYP2C9*3 genotype had significantly higher plasma irbesartan concentrations when compared with those with the CYP2C9*1/CYP2C9*1 genotype (beta +/- SE = 81 +/- 36) and greater DBP response (beta +/- SE = 5.6 +/- 2.5 mmHg) at the 6-h time point after adjusting for important confounders. Our finding suggests that the CYP2C9*3 gene variant significantly alters the plasma concentration and acute DBP response at the 6-h point following irbesartan treatment in Chinese hypertensive patients.

Genotypic diversity of oral Actinomyces naeslundii genospecies 1 and 2 in caries-active preschool children

A total of 991 isolates of Actinomyces naeslundii were obtained from sound approximal tooth sites in either caries-active (n = 35) or caries-free (n = 20) preschool children. From this group of isolates, 101 strains were chosen to study the genotypic diversity of A. naeslundii genospecies 1 (n = 30), catalase-positive (n = 30), and catalase-negative genospecies 2 (n = 41). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), with a pair of primers targeting the 16S ribosome RNA gene (16S rDNA), and MnlI digestion together with randomly amplified polymorphic DNA (RAPD) with eight arbitrary, single 10-mer primers were performed to generate genetic profiles of selected Actinomyces isolates. The hierarchic relationships of genetic profiles were finally analyzed using computerized dendrograms. There was no significant difference in the prevalence rates and proportions of either genospecies 1 or 2 between the caries-free and caries-active groups, although a higher prevalence of genospecies 2 was noted in the total population. Dendrogram analyses of the 16S rDNA PCR-RFLP profiles revealed that all strains belonging to A. naeslundii genospecies 1 could be subgrouped into three genotypes (T7, T18, and T19), with a single predominant genotype, T18 (27/30). Catalase-positive strains for genospecies 2 fell into three subtypes (T4, T7, and T17), whereas the catalase-negative counterparts were distributed amongst 16 subtypes. No specific genotype was significantly associated with caries activity. We conclude that heterogeneous subgroups of A. naeslundii genospecies 1 and 2, particularly the latter, are the constituent flora of dental plaque in children and may contribute to the pathogenesis of childhood caries.

Molecular evaluation of residual endodontic microorganisms after instrumentation, irrigation and medication with either calcium hydroxide or Septomixine

BACKGROUND AND OBJECTIVE

The correct choice of antimicrobial agents as inter-appointment medicaments is as important as the instrumentation and irrigation to remove pathogens from infected root canals. Calcium hydroxide [Ca(OH)2] and framycetin sulfate (Septomixine) are common endodontic medicaments. Therefore, we evaluated the efficacy of either calcium hydroxide or Septomixine in eliminating residual intra-canal bacteria, particularly Actinomyces spp., during inter-appointment interval in endodontic therapy using molecular methods.

METHODS

A total of 31 single-rooted teeth with primary root canal infections were studied immediately after opening the canals and subsequently after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 25) or Septomixine (n = 6). Whole bacterial genomic DNA was isolated directly from samples and PCR with universal primers performed to detect total intra-canal bacteria. The variable regions of 16S rDNA of bacteria were amplified and labeled with digoxigenin for further hybridization to detect Actinomyces spp. A total of seven oligonucleotide probes specific for A. bovis, A. gerencseriae, A. israelii, A. meyeri, catalase-negative A. naeslundii (genospecies 1 and 2), catalase-positive A. naeslundii genospecies 2 and A. odontolyticus were used to detect Actinomyces spp. in 22 of 31 medicated root canals [Ca(OH)2: n = 17; Septomixine: n = 5].

RESULTS

The PCR results showed that 25 of 31 examined canals were positively detected with residual microorganisms after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 20) or Septomixine (n = 5). Thus, only six canals [Ca(OH)2: n = 5, Septomixine: n = 1] were aseptic after treatment. Hybridization results showed higher detection frequency of both A. odontolyticus and A. gerencseriae after treatment. Significant correlation was found between exposed pulp before treatment and positive detection of Actinomyces spp., particularly A. odontolyticus on the second visit (P < 0.05).

CONCLUSION

The conventional, 1-week medication of either Ca(OH)2 or Septomixine in endodontic therapy may not effectively inhibit residual bacterial growth in all root canals during inter-appointment intervals. Further investigations using, for instance quantitative real-time PCR analyses, are required to substantiate the present findings.

Reverse transcriptase polymerase chain reaction (RT-PCR) detection of HLP gene expression in Candida glabrata and its possible role in in vitro haemolysin production

Although haemolysins are known to be putative virulence factors contributing to pathogenicity in Candida species, the haemolytic activity of Candida glabrata and its genetic expression is ill understood at present. Thus, we studied a total of 34 Candida glabrata isolates for their in vitro haemolytic activity using a previously described plate assay system. The mRNA expression of HLP, a putative haemolysin gene, of these isolates was also evaluated using a semi-quantitative, non-competitive RT-PCR assay. All 34 C. glabrata isolates exhibited both partial (alpha) and complete (beta) haemolytic activity to varying degrees. In parallel with the haemolytic activity, all isolates were also positive for HLP mRNA expression. The expression levels of HLP mRNA (as relative units) ranged from 1.01 to 1.82, with a mean value of 1.32. On regression analysis of latter values and the haemolytic activity (in terms of the dimension of the haemolytic zone in the plate assay) of the C. glabrata isolates a highly significant positive correlation was noted (r=0.759, p<0.0001). Taken together, our data illustrate not only the phenotypic characteristics of haemolysin(s) and HLP expression of a battery of C. glabrata clinical isolates, but also, for the first time, evidence for a role of HLP in haemolysis.

Actinomyces spp. in supragingival plaque of ethnic Chinese preschool children with and without active dental caries

Very limited molecular epidemiological data are available on the role of Actinomyces spp. in the pathogenesis of caries in the primary dentition. Therefore, we investigated their distribution in supragingival plaque of ethnic Chinese preschool children from Singapore and Hong Kong, either with or without active caries. Plaque samples were taken from intact interproximal enamel areas using dental floss. Bacterial genomic DNA of each sample was extracted and variable regions of 16S ribosomal DNA amplified and labelled with digoxigenin. Oligonucleotide probes specific for Actinomyces bovis, Actinomyces gerencseriae, Actinomyces israelii, Actinomyces meyeri, Actinomyces odontolyticus, catalase-negative Actinomyces naeslundii (genospecies 1 and 2) and catalase-positive Actinomyces naeslundii genospecies 2 (previously Actinomyces viscosus serotype II) were used to detect these species using Southern hybridization with a Minislot and Miniblotter system. A. odontolyticus, A. gerencseriae and A. meyeri were detected with similar frequency in both Singapore and Hong Kong samples or in those with and without active caries. However, the prevalence of A. naeslundii was significantly different in the two locales (p<0.05). A. odontolyticus (88.7%), A. gerencseriae (56.6%) and A. naeslundii (50.9%) were detected in a majority of the samples and the positive hybridization signals of A. gerencseriae in the caries-active group were stronger than from the caries-free group. A. bovis and A. israelii were undetectable in any of the samples. These data imply that A. odontolyticus, A. naeslundii and A. gerencseriae may play an important role in supragingival plaque formation on primary teeth in ethnic Chinese, with others such as A. meyeri contributing.

Development of novel oligonucleotide probes for seven Actinomyces species and their utility in supragingival plaque analysis

OBJECTIVE

The traditional, biochemical and enzymatic methods of identifying Actinomyces species are frequently confounded by the similar phenotypic characteristics shared by the different members of this genus. Therefore, we developed novel species-specific oligonucleotide probes to accurately speciate seven pathogenic Actinomyces species, namely, Actinomyces bovis, A. gerencseriae, A. israelii, A. meyeri, A. naeslundii, A. odontolyticus and A. viscosus.

METHODS

A pair of universal primers and seven 15- to 19-base oligonucleotide probes with a tail of 20 thymidines on the 5' end were developed. The variable regions of 16S ribosomal DNA of 36 strains of Actinomyces belonging to the above species were amplified and labeled with digoxigenin, and an oligonucleotide-DNA hybridization assay was performed to examine the specificity and sensitivity of these probes.

RESULTS

All seven, newly developed probes were specific and sensitive, and accurately detected 36 reference and wild type strains belonging to Actinomyces species, without cross-reactions. The probe for A. naeslundii detected all strains belonging to the genospecies 1 (12 strains) and catalase-negative genospecies 2 (four strains); it failed to detect catalase-positive A. naeslundii genospecies 2 (previous A. viscosus serotype II) (two strains). However, the latter strains of catalase-positive A. naeslundii genospecies 2 were correctly detected by the probe developed for A. viscosus. The new probes were then field tested using supragingival plaque samples from 28 healthy preschool children. Whilst A. odontolyticus was detected in almost all samples (96.4%), A. gerencseriae, A. meyeri, catalase-negative A. naeslundii and catalase-positive A. naeslundii genospecies 2 were detected in < 50% samples.

CONCLUSION

We conclude that the developed oligonucleotide probes, complementary to the variable regions of 16S rDNA, would be of potential value for differentiating Actinomyces spp. in clinical samples from the oral cavity and other ecosystems where such species may abound.