Is suppression of apoptosis a new therapeutic target in sepsis?

Sepsis remains as a leading cause of death in critically ill patients. Unfortunately, there have been very few successful specific therapeutic agents that can significantly reduce the attributable mortality and morbidity of sepsis. Developing novel therapeutic strategies to improve outcomes of sepsis remains an important focus of ongoing research in the field of critical care medicine. Apoptosis has recently been identified as an important mechanism of cell death and evidence suggests that prevention of cell apoptosis can improve survival in animal models of sepsis and endotoxaemia. In this review article, we summarise the critical role of apoptosis of the immune cells in the pathophysiology of sepsis and propose that blocking cell-signaling pathways leading to apoptosis may present a promising specific therapy for sepsis. Various methods to inhibit apoptosis including the cell surface Fas receptor pathway inhibitors, caspase inhibitors, over-expression of anti-apoptotic genes and small interfering ribonucleic acid therapy are discussed.

Variation in UDP glucouronyltransferase (UGT) genes associated with prostate cancer mortality

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Background: We investigated the association of germline genetic variation in hormone biosynthesis and metabolism genes with prostate cancer specific mortality in a cohort of advanced prostate cancer patients.

Methods: We successfully genotyped 852 single nucleotide polymorphisms (SNPs) from 97 genes in a cohort of 267 advanced prostate cancer patients at the time of progression to castration recurrence (CRPC) during on-going androgen ablation. Tagging SNPs with minor allele frequency (MAF) of >5% and r2 ≥0.8 were selected from HapMap, NIEHS and Seattle SNP databases. Medical records were queried for cause of death. The primary endpoint of time to prostate cancer specific mortality (PCSM), was pre-defined as time from development of CRPC to death from prostate cancer progression. Principle components analysis was used for gene-levels tests, and to account for multiple testing, we calculated the false discovery rate (FDR). For SNP level results, hazard ratios (HR) and 95% confidence intervals (CI) were estimated using cox regression.

Results: The median age of the cohort was 72 years at CRPC. 43% had a Gleason score (GS)=8-10, 33% a GS=7, and 24% a GS<7. After a median follow-up of 1.8 years (IQ range: 0.8–3.3 years), 139 patients died, of which 107 were due to prostate cancer progression. In unadjusted gene level analyses, UGT1A7 (p=0.0059; FDR=0.19), UGT1A10 (p=0.0017; FDR=0.17) and UGT1A3 (p=0.0037; FDR=0.18) were associated with PCSM. After adjusting for age and GS, SNPs strongly associated with PCSM are listed in the Table .

Conclusions: Variation in UGT genes involved in hormone metabolism yield prognostic information in CRPC. Further validation is needed to develop these as prognostic biomarkers.

[Table: see text]

No significant financial relationships to disclose.

Use of variation in sex steroid methyl transferases to predict efficacy of androgen-deprivation therapy (ADT) in advanced prostate cancer

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Background: We evaluated the association of germline variation in genes regulating hormonal pathways with duration of treatment response in prostate cancer patients receiving ADT, focusing on genes in the androgen biosynthesis (the C4 Δ; C5 Δ; C21 CYP pathways and the alternate “backdoor pathway”) and metabolism pathways.

Methods: We successfully genotyped 747 single nucleotide polymorphisms (SNPs) from 84 genes in a cohort of 304 patients with advanced prostate cancer who progressed on ADT. Tagging SNPs with a minor allele frequency (MAF) of >5% and r2 ≥0.8 were selected from HapMap, NIEHS and Seattle SNP databases. The primary endpoint was time to ADT failure, and we conducted a gene-level test (principal components), along with individual SNP level tests adjusted for patient age and Gleason score. To account for multiple testing, we calculated the false discovery rate (FDR), and FDRs of 0.10 were considered noteworthy.

Results: The median age of the cohort at ADT failure was 72 years (range 65-78 years), and the overall median time to ADT failure was 3.21 years (IQ [25-75]: 1.54-6.20 years). At the gene level, TRMT11 (tRNA methyltransferase 11 homologue) showed the strongest association with time to ADT failure (p<0.0008; adjusted p-value for FDR-0.068). Two of four TRMT11 tag SNPs were associated with time to ADT failure. The first was the intronic SNP rs1268121 (A>G) with a MAF of 15%, for which there was a positive association of median time to ADT failure with the number of variant alleles (p=0.023): 3.1 years for 0, 4.1 years for 1, and 5.9 years for 2 variant alleles. The second was the SNP rs6900796 (A>G) in the 3' untranscribed region with a MAF of 49%, for which the median time to ADT failure was 2.6 years for 0, 2.5 years for 1, and 3.8 years for 2 variant alleles (p=0.023). Four additional genes showed an association with ADT response at the p<0.10 level, including LOC390956, PRMT3, SLC7A6OS, and WBSCR22, although all FDRs were >0.95.

Conclusions: Variation in TRMT11 was associated with time to ADT failure. Confirmation of these findings in an independent cohort is needed.

No significant financial relationships to disclose.

Properties of Piezoelectric Pzt Thin Films for Microactuator Applications

The piezoelectric properties of lead zirconate titanate (PZT) thin films deposited on thick silicon substrates and thin silicon membranes were investigated using optical interferometry. The effect of the geometrical constraints and clamping effects on the piezoelectric response is discussed. The study of the dielectric permittivity and the loss as a function of the amplitude of the alternating electric field reveals that extrinsic contributions to the dielectric permittivity become active at large fields. The DC electric field has the effect of freezing out the extrinsic contributions. The influence of the dielectric loss on the piezoelectric properties is discussed.

Ecotoxicity of a brominated flame retardant (tetrabromobisphenol A) and its derivatives to aquatic organisms

The large use of tetrabromobisphenol A (B(4)BPA) in common products (plastics, electric and electronic equipments) has raised concern about its ecotoxicity. Physical and bio-degradations may lead to the formation of tetrabromobisphenol A derivatives like tri- (B(3)BPA), di- (B(2)BPA), monobromobisphenol A (B(1)BPA) and bisphenol A (BPA). However, little is known about the toxicity of these brominated derivatives. An appraisal on the ecotoxicity of B(4)BPA and its derivatives was carried out with several bioassays representing organisms (bacteria, algae, micro-invertebrates and fish) of different taxonomic groups present in aquatic ecosystems. Endpoint values showed that B(4)BPA was significantly less toxic than the other chemicals when tested with the Microtox and algal asssays. A similar trend was observed with other bioassays for BPA. One of the brominated derivatives was particularly toxic: B(2)BPA. The LuminoTox assay and the rainbow trout hepatocytes assay reported the most significant toxicity for this derivative. Its toxicity was also significantly higher than the other compounds barring B(3)BPA when tested with the micro-crustacean test.

Incidence and factors related to flare-ups in a graduate endodontic programme

AIM

To investigate the incidence and factors related to endodontic flare-ups in nonsurgical root canal treatment (NSRCT) cases completed by graduate endodontic residents at University of Pennsylvania, USA.

METHODOLOGY

Residents at University of Pennsylvania enter all clinical patient records into an electronic database called PennEndo database. Analysis of records of 6580 patients treated from September 2000 to July 2005 revealed a total of 26 patients with flare-ups (0.39%). Patients were categorized to have undergone flare-up when they attended for an unscheduled visit and active treatment, and when they suffered from severe pain and or swelling after initiation or continuation of NSRCT. SAS software was used to develop a logistic regression model with flare-up as a dependent variable. Independent variables included in the model were: history of previous pain, one vs. two visit NSRCT, periapical diagnosis, tooth type, rotary versus hand instrumentation, and lateral versus vertical compaction of gutta-percha.

RESULTS

The odds for developing a flare-up in teeth with a periapical radiolucency were 9.64 times greater than teeth without a periapical radiolucency (P = 0.0090). There was no statistically significant difference in flare-ups between one and two visits NSRCT. The odds of developing a flare-up increased 40 fold when NSRCT was completed in three or more visits. However, this result may have been confounded by addition of an unscheduled visit in patients suffering from flare-ups. Other independent variables did not have any statistically significant correlations.

CONCLUSIONS

A low percentage of patients experienced flare-ups during NSRCT procedures. The presence of a periapical lesion was the single most important predictor of flare-ups during NSRCT.

Mandibular canal variant: a case report

The mandibular canal transmits the inferior alveolar artery, vein and the inferior alveolar nerve. From an embryological perspective, there might be three inferior dental nerves innervating three groups of mandibular teeth. During rapid prenatal growth and remodeling in the ramus region there is spread of intramembranous ossification that eventually forms the mandibular canal. Occurrence of bifid/trifid mandibular canals in some patients is secondary to incomplete fusion of these three nerves. Various types of bifid mandibular canals have been classified according to anatomical location and configuration. This case report highlights an unusual variant of the mandibular canal.

Estimating the long-term impact of a prophylactic human papillomavirus 16/18 vaccine on the burden of cervical cancer in the UK

To predict the public health impact on cervical disease by introducing human papillomavirus (HPV) vaccination in the United Kingdom, we developed a mathematical model that can be used to reflect the impact of vaccination in different countries with existing screening programmes. Its use is discussed in the context of the United Kingdom. The model was calibrated with published data. The impact of vaccination on cervical cancer and deaths, precancerous lesions and screening outcomes were estimated for a vaccinated cohort of 12-year-old girls, among which it is estimated that there would be a reduction of 66% in the prevalence of high-grade precancerous lesions and a 76% reduction in cervical cancer deaths. Estimates for various other measures of the population effects of vaccination are also presented. We concluded that it is feasible to forecast the potential effects of HPV vaccination in the context of an existing national screening programme. Results suggest a sizable reduction in the incidence of cervical cancer and related deaths. Areas for future research include investigation of the beneficial effects of HPV vaccination on infection transmission and epidemic dynamics, as well as HPV-related neoplasms in other sites.

A phase II report of longitudinal bone marker time trends in racially diverse prostate cancer patients receiving zoledronic acid with androgen deprivation

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Background: Evidence for preventing androgen deprivation (AD) induced osteoporosis with bisphosphonate therapy in prostate cancer patients has emerged largely from trials conducted in caucasian patients. Osteoporosis related skeletal event incidence in African Americans (AA) receiving AD is significantly lower than caucasians and the effect of bisphosphonates therapy uncertain. We conducted a prospective study to evaluate the efficacy of zoledronic acid in preventing osteoporosis in racially diverse population receiving AD. Methods: Asymptomatic, prostate cancer patients (16 caucasians and 6 AA) with normal renal function undergoing AD, started within the last 9 months were randomized to receive (Arm A) CaCO3/vitamin D (500 mg/200U TID) or (Arm B) CaCO3/vitamin D and zoledronic acid (4 mg IV every 3 months for a year). Bone turnover markers including urine N-telopeptide, serum osteocalcin, serum bone specific alkaline phosphatase(BsAP) were serially measured every 3 months and bone mineral density (BMD) measured by DXA at hip, femur, spine and ward’s triangle at 0, 6 and 15 month intervals. Primary endpoint was to obtain BMD changes and bone turnover rates for each treatment arm. Nonparametric methods for analyzing longitudinal data were used to compare DXA-derived BMD measures and bone turnover rate markers in patients receiving zoledronic acid to the control group. Results: Data is presented for 16/22 patients who have completed 15- month follow up. Time trend analysis of bone formation (BsAP, osteocalcin) and resorption (N-telopeptide) markers and DXA measurements of BMD (spine and hip) are shown in the table. Conclusions: This study suggests that zoledronic acid preserves BMD at spine in racially diverse patients and, likewise provides preliminary estimates of BMD changes that occur over 15 months in patients receiving zoledronic acid and placebo. Larger AA cohorts are needed for prospective validation of the observed effect with zoledronic acid. [Table: see text]

[Table: see text]

Cellular localization of thrombin in prostate: Implications for thrombin targeted therapy in prostate cancer

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Background: Tumor and coagulation interaction is complex and heterogeneous. Expression of an intact repertoire of coagulation proteins is not detected in all tumor types. Thrombin, a key coagulation protein, which has been observed to promote tumorigenesis in experimental models, is not expressed on breast, colon and squamous lung cancer cells, but has been detected on small cell lung, melanoma and renal cancer epithelium. In prostate cancer, expression of its receptor, protease activated receptor-1 (PAR-1) has been previously reported but thrombin expression on epithelium not determined. Therefore, we evaluated thrombin and prothrombin expression in prostate specimens. Methods: Quantitative real-time PCR was performed for (pro)thrombin mRNA expression in fresh prostate cancer tissue lysates obtained from localized disease (n = 9 prostatectomy specimens) and advanced disease (n = 7 channel trans-urethral prostate resection specimens). Prothrombin and thrombin protein immunohistochemistry was performed on anonymized prostate tissue micro arrays which included benign (n = 117), prostate intra-epithelial neoplasia (PIN; n = 26) and prostate cancer (n = 112) cores. Results: (Pro)thrombin mRNA expression (normalized to 18s mRNA) was detected in all cancer tissue lysates. Mean intensity of expression in advanced cancer specimens was 20.3 compared to 14.0 for local stage specimens (p = 0.09; Wilcoxon rank sum test). Spatially, expression of thrombin was detected in stroma, benign and malignant epithelium (see Table) and on vascular endothelium. Prothrombin localization was similar to thrombin expression. Conclusions: Thrombin’s tumorigenic effects via PAR-1 activation provide novel therapeutic targets in tumors expressing thrombin-PAR1 axis. The current study confirms thrombin expression on prostate epithelium and taken with previous results of PAR1 epithelial expression, provides a rationale for exploring specific thrombin inhibitors and/or PAR inhibitors in prostate cancer. [Table: see text]

No significant financial relationships to disclose.