Abstract P5-05-04: Intraductal delivery of RNAi-based therapeutics to gene targets identified through computational systems modeling

We utilize a computational systems biology approach to identify gene targets with the potential to serve as targets for therapeutic RNAi. Inferred gene regulatory network models were constructed using whole transcriptome expression profiling for progressive stages of mammary tumorigenesis in FVB C3(1)-SV40Tag mice. These computational models predicted key mediator transcription factors that are critical for hyperplasia and ductal filling in the early stages of disease progression. Putative mediator transcription factors were targeted by RNAi first in a mammary spheroid assay. Based on their ability to restore lumen formation and normal apical-basal polarization to mammary tumor cells, two transcription factors, Hoxa1 and Hoxb13, were selected for validation in vivo. siRNA targeting each of these transcription factors was formulated with lipidoid nanoparticles and delivered to the mammary gland via intraductal injection. Silencing Hoxa1 resulted in a significant reduction in tumor incidence in FVB C3(1)-SV40Tag. This represents a novel strategy to achieve localized silencing of a target gene in the mammary epithelium.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-05-04.

Comparison of two selective media for the recovery of Clostridium difficile from environmental surfaces

Two culture media were compared for their ability to isolate Clostridium difficile from environmental sites within a UK hospital. The media were cefoxitin-cycloserine-egg yolk agar plus lysozyme (CCEY/L) and chromID C. difficile. A wide range of environmental surfaces was sampled using sterile sponges (Polywipes) and these were inoculated on to both media. C. difficile was recovered from 105 of 496 sites (21%) using a combination of both media. The sensitivity of chromID C. difficile was 87.6% compared with 26.6% for CCEY/L (P < 0.0001). chromID C. difficile performed significantly better than CCEY/L for the recovery of C. difficile from the environment.

Evaluation of Preoperative Risk Factors for Converting Laparoscopic to Open Cholecystectomy

Performing laparoscopic cholecystectomy (LC) always carries the risk of having to convert from laparoscopic to open cholecystectomy (LOC). Being able to identify these patients preoperatively may allow better preoperative planning and lowering operative cost. All LC and LOC were performed by the Eastern Virginia Medical School Department of Surgery retrospectively identified between January 2008 and December 2009. Preoperative risk factors identified in both groups included: age, gender, body mass index greater than 30 kg/m2, diabetes mellitus, previous upper abdominal surgery, previous abdominal surgery, presence of pericholecystic fluid, gallbladder wall thickness greater than 3 mm, preoperative diagnosis of acute cholecystitis, and pancreatitis. Reasons for conversion in the LOC group were identified from the operative note. A total of 346 LC and LOC were identified. The LOC group had 41 identified with a conversion rate of 11.9 per cent. The LOC group was compared with 100 randomly chosen LC. Risk factors that reached statistical significance for conversion included advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and gallbladder wall thickness greater than 3 mm ( P = 0.0009). Average operative time was higher in LOC compared with open cholecystectomy (123 minutes average vs 109 minutes average). Of the reasons for conversion, the degree of inflammation was the most common (51.2%). Preoperative risk factors that were associated with need for conversion were advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and pericholecystitic fluid. In patients who have all of these risk factors, we recommend starting with an open cholecystectomy. This will save operative time and overall cost.

Evaluation of preoperative risk factors for converting laparoscopic to open cholecystectomy

Performing laparoscopic cholecystectomy (LC) always carries the risk of having to convert from laparoscopic to open cholecystectomy (LOC). Being able to identify these patients preoperatively may allow better preoperative planning and lowering operative cost. All LC and LOC were performed by the Eastern Virginia Medical School Department of Surgery retrospectively identified between January 2008 and December 2009. Preoperative risk factors identified in both groups included: age, gender, body mass index greater than 30 kg/m(2), diabetes mellitus, previous upper abdominal surgery, previous abdominal surgery, presence of pericholecystic fluid, gallbladder wall thickness greater than 3 mm, preoperative diagnosis of acute cholecystitis, and pancreatitis. Reasons for conversion in the LOC group were identified from the operative note. A total of 346 LC and LOC were identified. The LOC group had 41 identified with a conversion rate of 11.9 per cent. The LOC group was compared with 100 randomly chosen LC. Risk factors that reached statistical significance for conversion included advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and gallbladder wall thickness greater than 3 mm (P = 0.0009). Average operative time was higher in LOC compared with open cholecystectomy (123 minutes average vs 109 minutes average). Of the reasons for conversion, the degree of inflammation was the most common (51.2%). Preoperative risk factors that were associated with need for conversion were advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and pericholecystitic fluid. In patients who have all of these risk factors, we recommend starting with an open cholecystectomy. This will save operative time and overall cost.

Homeless in North and West Belfast: an oral health needs assessment

AIM

The aim was to assess the oral health needs of a homeless population residing in North and West Belfast Health and Social Services Trust area, in order to determine levels of unmet need and allow recommendations for service delivery to be made.

METHOD

A sample of single homeless people was gathered using a snowballing sampling technique. Fourteen hostels located in North and West Belfast were visited in tandem with the homeless health care coordinator. All consenting participants were asked to complete a detailed medical history questionnaire and a questionnaire to assess their health and psycho-social needs, dental anxiety and oral health related quality of life. All participants received an oral examination.

RESULTS

Three hundred and seventeen homeless people consented to take part. Two hundred and sixty-seven (84%) were male. Thirty three percent of participants had mental health problems including psychotic illness, depression and anxiety. Forty-three percent of the sample stated they were addicted to alcohol and 3% were registered injecting drug users. Five percent (16) of the sample had soft tissue swellings of which two were found to be oral cancer. The participants had a mean D(3cv)MFT of 16.16 (95% CI: 15.71, 17.46). Seventy-fi ve percent of the sample had bleeding gums and calculus; however only 4%had pocket depths of 6 mm or more. Dental anxiety status was related to dental disease experience which impacted negatively on quality of life. Forty-seven percent of the participants felt at least occasionally self-conscious and/or felt ashamed by the appearance of their teeth.

CONCLUSIONS

Health and psychosocial factors associated with being homeless must be incorporated into the delivery of context-sensitive oral healthcare for this socially excluded population.

Epidemiological survey of Clostridium difficile ribotypes in the North East of England during an 18-month period

During an 18-month period, 1606 stool specimens from laboratory-confirmed cases of Clostridium difficile infection in the North East of England were ribotyped using unrestricted polymerase chain reaction. Of these, 87.6% grew C. difficile on culture; 70% had one of 10 recognizable ribotypes of which 001, 106 and 027 were the most prevalent. The proportions of ribotypes 002 and 015 declined during the study period, whereas ribotypes 016 and 023 increased. Ribotype 005 was significantly more numerous in males and ribotype 027 was associated with significantly higher mean age. Our findings differ from national data derived from more selective testing.

Computational strategy for tuning spectral properties of red fluorescent proteins

Computational methods of quantum chemistry are used to characterize structures and vertical excitation energies of the S(0)-S(1) optical transitions in the chromophore binding pockets of the red fluorescent proteins DsRed and of its artificial mutant mCherry. As previously shown, optimizing the equilibrium geometry configurations with B3LYP density functional theory, followed by ZINDO calculations of the electronic excitations, yields positions of the optical bands in good agreement with experimental data. These large scale quantum calculations elucidate the role of the hydrogen bonded network as well as point mutations in the absorption spectra of the DsRed and mCherry proteins. The effect of an external electric field applied to the fluorescent protein chromophores is examined and shows that such fields may result in large shifts in spectral bands. These strategies can be applied for rational design of the fluorescent proteins by site-directed mutagenesis.

Successful treatment of ventilator dependent emphysema with Chartis treatment planning and endobronchial valves

INTRODUCTION

Emphysema is a leading cause of disability and death. Patients who require ventilator support as a result of respiratory failure have limited treatment options. We report a successful outcome for a ventilator dependent patient in whom endobronchial valves were inserted into lobes assessed as being without collateral ventilation.

PRESENTATION OF CASE

A 54 year old male patient had been ventilator dependent for two months due to respiratory insufficiency from emphysema. Prior to admission, FEV(1) was 0.89L (25% predicted) and RV was 4.5L (205% predicted). CT scan showed destruction of right lower and middle lobes and left lower lobe. Chartis assessment showed the absence of collateral ventilation. Zephyr endobronchial valves were placed in left and right lower lobes. Lung volume reduction bilaterally was confirmed on chest X-ray and CT scan the following day. On day three, ventilator support was discontinued and there was no requirement for supplementary oxygen. At 30 days post procedure, the RV reduced to 3.2L (142% predicted) and the FEV(1) increased to 1.32L (38% predicted).

DISCUSSION

Hyperinflation in emphysema compromises lung function. For this ventilator dependent patient, there were no other treatment options. Endoscopic lung volume reduction was successfully achieved by bilateral lower lobe placement of Zephyr endobronchial valves with a prior assessment using Chartis to determine the absence of collateral flow in the targeted lobes. The patient achieved an impressive 48% improvement in FEV(1) and a 29% reduction in RV.

CONCLUSION

Endoscopic lung volume reduction assisted by Chartis to plan treatment resulted in a clinical and a health-economic benefit.

Review of a three-year meticillin-resistant Staphylococcus aureus screening programme

The Newcastle upon Tyne Hospitals NHS Foundation Trust (NuTH) implemented a seek and destroy (S&D) programme in 2006 to minimise meticillin-resistant Staphylococcus aureus (MRSA) colonisation and/or infection of patients. Using a phased introduction, all patient specialties were included in the scheme by September 2008, well in advance of the mandatory Department of Health, England (DoH) requirement for all patients to be screened. NuTH screens nose, throat and perineum samples from approximately 15,000 patients per month using a chromogenic culture method, showing a mean MRSA prevalence of 2.4%. Provision of seven-day microbiology and infection control services ensured that the turnaround time to prescribing decolonisation therapy was <24 h. Analysis of 168,073 results identified the necessity for inclusion of all three screening sites to maximise recovery of MRSA. Appraisal of the S&D policy demonstrated that MRSA detection rates did not increase despite an exponential increase in workload owing to mandatory inclusion of low risk areas in the screening programme. Review of data during a typical one-month period indicated that only seven day-case patients would not have been identified as MRSA carriers using our targeted S&D approach compared with the DoH universal screening. Detection of these additional patients incurred total laboratory costs of £20,000 and generated a further 4200 associated negative screens in one month alone. Our study indicates that a screening strategy based upon clinical risk is more pragmatic and more cost-effective than the universal programme currently required in England.

Long-term results of International Breast Cancer Study Group Trial VIII: adjuvant chemotherapy plus goserelin compared with either therapy alone for premenopausal patients with node-negative breast cancer

BACKGROUND

The International Breast Cancer Study Group Trial VIII compared long-term efficacy of endocrine therapy (goserelin), chemotherapy [cyclophosphamide, methotrexate and fluorouracil (CMF)], and chemoendocrine therapy (CMF followed by goserelin) for pre/perimenopausal women with lymph-node-negative breast cancer.

PATIENTS AND METHODS

From 1990 to 1999, 1063 patients were randomized to receive (i) goserelin for 24 months (n = 346), (ii) six courses of 'classical' CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy (n = 360), or (iii) six courses of CMF plus 18 months goserelin (CMF→ goserelin; n = 357). Tumors were classified as estrogen receptor (ER) negative (19%), ER positive (80%), or ER unknown (1%); 19% of patients were younger than 40. Median follow-up was 12.1 years.

RESULTS

For the ER-positive cohort, sequential therapy provided a statistically significant benefit in disease-free survival (DFS) (12-year DFS = 77%) compared with CMF alone (69%) and goserelin alone (68%) (P = 0.04 for each comparison), due largely to the effect in younger patients. Patients with ER-negative tumors whose treatment included CMF had similar DFS (12-year DFS CMF = 67%; 12-year DFS CMF→ goserelin = 69%) compared with goserelin alone (12-year DFS = 61%, P= NS).

CONCLUSIONS

For pre/perimenopausal women with lymph-node-negative ER-positive breast cancer, CMF followed by goserelin improved DFS in comparison with either modality alone. The improvement was the most pronounced in those aged below 40, suggesting an endocrine effect of prolonged CMF-induced amenorrhea.

Luminescence and decay properties of the 1D2 level of Pr3+-doped YPO4

This investigation reports on the spectroscopic properties of trivalent Pr in YPO4. In particular, we show how the luminescence from the 1D2 level depends on the polarization of the emission and on the temperature of the sample. We also report on the decay kinetics of the 1D2 level, which show the lifetime decreasing as temperature is increased. Our observed lifetime of 440 µs is at low temperature and is significantly longer than that reported by other workers. We explain the temperature dependence of the 1D2 emission by considering the population redistribution in the 1D2 level, without invoking the existence of multiphonon relaxation. Finally, we estimate the radiative decay rates of individual crystal field levels within the 1D2 manifold.

Gene expression and mutation assessment provide clues of genetic and epigenetic mechanisms in liver tumors of oxazepam-exposed mice

Liver tumors from a previous National Toxicology Program study were examined using global gene expression and mutation analysis to define the mechanisms of carcinogenesis in mice exposed to oxazepam. Five hepatocellular adenomas and 5 hepatocellular carcinomas from male B6C3F1 mice exposed to 5000 ppm oxazepam and 6 histologically normal liver samples from control animals were examined. One of the major findings in the study was upregulation of the Wnt/β-catenin signaling pathway. Genes that activate β-catenin, such as Sox4, were upregulated, whereas genes that inhibit Wnt signaling, such as APC and Crebbp, were downregulated. In addition, liver tumors from oxazepam-exposed mice displayed β-catenin mutations and increased protein expression of glutamine synthetase, a downstream target in the Wnt signaling pathway. Another important finding in this study was the altered expression of oxidative stress-related genes, specifically increased expression of cytochrome p450 genes, including Cyp1a2 and Cyp2b10, and decreased expression of genes that protect against oxidative stress, such as Sod2 and Cat. Increased oxidative stress was confirmed by measuring isoprostane expression using mass spectrometry. Furthermore, global gene expression identified altered expression of genes that are associated with epigenetic mechanisms of cancer. There was decreased expression of genes that are hypermethylated in human liver cancer, including tumor suppressors APC and Pten. Oxazepam-induced tumors also exhibited decreased expression of genes involved in DNA methylation (Crebbp, Dnmt3b) and histone modification (Sirt1). These data suggest that formation of hepatocellular adenomas and carcinomas in oxazepam-exposed mice involves alteration of the Wnt signaling pathway, oxidative stress, and potential epigenetic alterations.