Predictors of Tumor Dynamics during a 6-Week Course of Chemoradiotherapy for Glioblastoma

PURPOSE/OBJECTIVE(S)

Our prior imaging studies have shown geometrically meaningful inter-fraction tumor dynamics specific to glioblastoma (GBM). We aim to identify predictors associated with tumor dynamics during a 6-week course of concurrent chemoradiotherapy (CRT) for GBM.

MATERIALS/METHODS

Patients enrolled in a prospective serial magnetic resonance imaging (MRI) study were reviewed. All patients were treated with 54-60 Gy in 30 fractions. The gross tumor volume (GTV) included the surgical cavity and T1c enhanced residual tumor; clinical tumor volume (CTV) included GTV with a 15mm isotropic expansion, respecting anatomical boundaries; planning target volume (PTV) was 4mm expansion. MRIs were obtained at RT planning (F0), fraction 10 (F10), and fraction 20 (F20). Tumor dynamic metrics (relative to F0) assessed included the GTV volume (Vrel), Hausdorff distance (dH) and migration distance (dM). dH is the average distance between two datasets in metric space. dM is the maximum linear displacement of the GTV in any direction. Factors to be determined associated with tumor dynamics included: age, sex, corpus callosum (CC) involvement, extent of surgery (gross total resection (GTR), subtotal resection (STR) or biopsy alone (Bx)), MGMT methylation and IDH mutation status.

RESULTS

A total of 129 patients were reviewed. Median GTV was 20.9cc at F0, 17.6cc at F10 (Vrel 0.85), and 16.1cc at F20 (Vrel 0.78). Patients without CC involvement had more marked GTV volume reduction: Vrel 0.82 vs 1.02 with CC involvement at F10 (P = 0.05), and Vrel 0.77 vs 0.88 with CC involvement at F20 (P = 0.03). Patients with GTR (vs STR vs Bx) had more marked GTV volume reduction across all time points: Vrel 0.78, 0.85 and 1.07 respectively at F10 (P = 0.001), and Vrel 0.69, 0.80, 1.04 respectively at F20 (P = 0.001). The median dH was 8.1mm at F10 and 9.2mm at F20. Patients with CC involvement (vs without CC involvement) had a larger dH: 54% vs 25% had dH>10mm respectively at F10 (P = 0.03), and 73% vs 28% had dH>10mm respectively at F20 (P<0.005). Patients with a GTR had smaller dH at both F10 (P = 0.02) and F20 (P = 0.006). At F20, 20%, 47% and 37% of patients with GTR, STR and Bx had dH>10mm (P = 0.04). The median dM were 4.7mm at F10 and 4.7mm at F20. Patients with CC involvement (vs without CC involvement) had larger dM: 41% vs 12% had dM >10mm respectively at F10 (P = 0.01), and 45% vs 9% had dM >10mm respectively at F20 (P<0.001). Patients with GTR had smaller dM at F10 (P = 0.03) and F20 (P0.002). At F20, 0%, 25% and 19% of patients with GTR, STR and Bx had dM>10mm (P = 0.002). Age, sex, MGMT methylation and IDH mutation status were not associated with Vrel, dH and dM at F10 and F20.

CONCLUSION

We identified CC involvement and extent of surgery to be associated with tumor dynamics at F10 and F20 over the course of CRT for GBM. This offers opportunities to better select patients who may benefit from earlier/ more frequent RT replan/ adaptation to ensure adequate tumor coverage, or to reduce RT toxicities.

A Novel Strategy to Enhance Radiotherapy Efficacy: Results from the Prospective Phase I Clinical Trial of MR-Guided Focused Ultrasound-Stimulated Microbubbles (MRgFUS+MB) Treatment for Breast Cancer

PURPOSE/OBJECTIVE(S)

Preclinical in vitro and in vivo studies have demonstrated that tumor cell death can be enhanced 10- to 40-fold when radiotherapy (RT) is combined with focused-ultrasound (FUS)-stimulated microbubbles (MB) treatment. MBs are gas microspheres used as intravascular contrast agents. The acoustic exposure of MBs within the target volume causes bubbles cavitation that induces perturbation of tumor vasculature. This activates apoptotic pathways responsible for the ablative effect of stereotactic body radiotherapy, which would otherwise require high-dose radiotherapy (>8-10 Gy/fraction) to be activated. Subsequent irradiation of an MB-sensitized tumor causes increased anoxic tumor killing, which occurs in addition to canonical RT-induced DNA damage. Given the compelling results of preclinical data, we conducted a phase I clinical trial of magnetic resonance (MR)-guided FUS-stimulated MBs (MRgFUS+MB) treatment for breast cancer patients (pts). We report the safety and efficacy results of this new radio enhancement treatment.

MATERIALS/METHODS

This is a single-center, single-arm, investigator-initiated phase 1 clinical trial (NCT04431674). We included pts with stage I-IV breast cancer with tumor in situ for whom breast or chest wall RT was deemed adequate by a multidisciplinary team. Pts were excluded if they had contraindications for contrast-enhanced MR or MB administration. Pts underwent 2-3 MRgFUS+MB treatments throughout the RT course. We used an MR-coupled FUS-device operating at 500 KHz and 540 kPa peak negative pressure to deliver the treatment. The FUS sonicated intravenously administrated MB within the MR-guided target volume. Pts were monitored for 30-min post-procedure and subsequently treated with RT. The primary outcome was acute toxicity per Common Terminology for Adverse Events V5.0. Secondary outcomes were radiological response at 3 months and local control (LC) at 1 year. Kaplan-Meier method was used to estimate local control. All pts signed a written consent form before study participation.

RESULTS

We enrolled 18 females with 20 primary breast cancer treated with MRgFUS+MB therapy. The median age was 60 years (range, 44-90). The molecular subtypes consisted of basal-like (n = 3/20), luminal (n = 11/20), and HER2-enriched (n = 6/20). The prescribed dose was 20 Gy/5 fractions (n = 8/20), 30-35 Gy/5 fractions (n = 7/20), 30-40 Gy/10 fractions (n = 3/20), and 66 Gy/33 fractions (n = 2/20). The median follow-up was 9 months (range, 0.3-29). All pts completed the planned MRgFUS+MB treatments. The only MRgFUS+MB treatment-related toxicity consisted of Grade 1 allergic reaction (mild cough) 30 minutes after the last MB injection. All worst acute toxicities were radiation dermatitis (Grade 3 = 2/20, Grade 2 = 2/20, Grade 1 = 14/20). At 3 months, 75% had partial (n = 6/20) or complete (n = 9/20) response, with a single progression. The LC rate at 1 year was 86%.

CONCLUSION

MRgFUS+MB was a safe and efficient treatment that provided durable responses.

Implementable Deep Learning for Multi-sequence Proton MRI Lung Segmentation: A Multi-center, Multi-vendor, and Multi-disease Study

BACKGROUND

Recently, deep learning via convolutional neural networks (CNNs) has largely superseded conventional methods for proton (1 H)-MRI lung segmentation. However, previous deep learning studies have utilized single-center data and limited acquisition parameters.

PURPOSE

Develop a generalizable CNN for lung segmentation in 1 H-MRI, robust to pathology, acquisition protocol, vendor, and center.

STUDY TYPE

Retrospective.

POPULATION

A total of 809 1 H-MRI scans from 258 participants with various pulmonary pathologies (median age (range): 57 (6-85); 42% females) and 31 healthy participants (median age (range): 34 (23-76); 34% females) that were split into training (593 scans (74%); 157 participants (55%)), testing (50 scans (6%); 50 participants (17%)) and external validation (164 scans (20%); 82 participants (28%)) sets.

FIELD STRENGTH/SEQUENCE

1.5-T and 3-T/3D spoiled-gradient recalled and ultrashort echo-time 1 H-MRI.

ASSESSMENT

2D and 3D CNNs, trained on single-center, multi-sequence data, and the conventional spatial fuzzy c-means (SFCM) method were compared to manually delineated expert segmentations. Each method was validated on external data originating from several centers. Dice similarity coefficient (DSC), average boundary Hausdorff distance (Average HD), and relative error (XOR) metrics to assess segmentation performance.

STATISTICAL TESTS

Kruskal-Wallis tests assessed significances of differences between acquisitions in the testing set. Friedman tests with post hoc multiple comparisons assessed differences between the 2D CNN, 3D CNN, and SFCM. Bland-Altman analyses assessed agreement with manually derived lung volumes. A P value of <0.05 was considered statistically significant.

RESULTS

The 3D CNN significantly outperformed its 2D analog and SFCM, yielding a median (range) DSC of 0.961 (0.880-0.987), Average HD of 1.63 mm (0.65-5.45) and XOR of 0.079 (0.025-0.240) on the testing set and a DSC of 0.973 (0.866-0.987), Average HD of 1.11 mm (0.47-8.13) and XOR of 0.054 (0.026-0.255) on external validation data.

DATA CONCLUSION

The 3D CNN generated accurate 1 H-MRI lung segmentations on a heterogenous dataset, demonstrating robustness to disease pathology, sequence, vendor, and center.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 1.

Genetic polymorphism in Methylenetetrahydrofolate Reductase chloride transport protein 6 (MTHFR CLCN6) gene is associated with keratinocyte skin cancer in a cohort of renal transplant recipients

Background

Renal transplant recipients (RTRs) are at increased risk of keratinocyte cancer (KC), especially cutaneous squamous cell carcinoma (cSCC). Previous studies identified a genetic variant of the Methylenetetrahydrofolate Reductase (MTHFR) gene, C677T, which conferred a risk for diagnosis of cSCC in Irish RTRs.

Objective

We sought to find further genetic variation in MTHFR and overlap genes that may be associated with a diagnosis of KC in RTRs.

Methods

Genotyping of a combined RTR population (n = 821) from two centres, Ireland (n = 546) and the USA (n = 275), was performed. This included 290 RTRs with KC and 444 without. Eleven single nucleotide polymorphisms (SNPs) in the MTHFR gene and seven in the overlap gene MTHFR Chloride transport protein 6 (CLCN6) were evaluated and association explored by time to event analysis (from transplant to first KC) using Cox proportional hazards model.

Results

Polymorphism at MTHFR CLCN6 (rs9651118) was significantly associated with KC in RTRs (HR 1.50, 95% CI 1.17–1.91, p < 0.00061) and cSCC (HR 1.63, 95% CI 1.14–2.34, p = 0.007). A separate SNP, MTHFR C677T, was also significantly associated with KC in the Irish population (HR 1.31, 95% CI 1.05–1.63, p = 0.016), but not American RTRs.

Conclusions

We report the association of a SNP in the MTHFR overlap gene, CLCN6 and KC in a combined RTR population. While the exact function of CLCN6 is not known, it is proposed to be involved in folate availability. Future applications could include incorporation in a polygenic risk score for KC in RTRs to help identify those at increased risk beyond traditional risk factor assessment.

MATTHEW-WOOD SYNDROME: A CASE WITH DEXTROCARDIA AND STREAK GONADS

Matthew-Wood syndrome (MWS), also termed Microphthalmia, syndrome 9 (MCOPS9, MIM 601186), Spear syndrome, or pulmonary hypoplasia, diaphragmatic hernia, anophthalmia and cardiac defects syndrome (PDAC syndrome), is an autosomal recessive disorder characterised by ocular, respiratory and cardiac abnormalities. Mutations in retinoic acid 6 gene (STRA6) have been reported in clinically diagnosed patients with MWS. Here we presented a case with MWS, who has characteristic findings of the syndrome as well as dextrocardia as an undescribed feature, and bilateral streak gonads which was described only in one patient previously. Molecular analysis showed a homozygous exonic missense mutation in the STRA6 gene.

Missed Carotid Artery Cannulation: A Line Crossed and Lessons Learnt

We report a case of an infusion of intra-aortic propofol after the missed inadvertent placement of a centra venous catheter into the right common carotid artery. Radiological imaging revealed bilateral ischaemic infarct in the posterior fossa and right cerebral artery territories consistent with an embolic source. The potential cause of the neurological injuries sustained in this case are explored. Discussion focuses on the sequelae, managemen and prevention of an iatrogenic carotid artery injury from a central venous catheter insertion. Finally, we propose an algorithm for management of iatrogenic carotid artery cannulation.

Comparison of coagulation and MIEX pre-treatment processes for bacterial and turbidity removal, utilizing real-time optical monitoring techniques

Jar testing and flow cytometry were used in conjunction with photometric dispersion analysis (PDA) to assess conventional alum coagulation with and without magnetic ion exchange (MIEX) pre-treatment for turbidity and bacterial removal capacity. Treatment assessment included powdered activated carbon (PAC) and pre-chlorination of the MIEX-treated raw water. Floc particles were subjected to shear forces after settling and re-suspended to gauge bacterial release potential, floc breakage and re-aggregation. MIEX in conjunction with alum coagulation achieved improved coagulation as measured by PDA but did not increase bacterial log removal value (LRV) in comparison with conventional coagulation. Pre-chlorination and PAC addition were seen to improve bacterial removal and coagulation, respectively, but were less effective for bacterial LRVs when they were used in conjunction during coagulation.

Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: use of pH reduction, zeolite, biomass and humic acid

High free ammonia released during anaerobic digestion of livestock wastes is widely known to inhibit methanogenic microorganisms and result in low methane production. This was encountered during our earlier thermophilic semi-continuously fed continuously-stirred tank reactor (CSTR) treatment of piggery wastewater. This study explored chemical and biological means to mitigate ammonia inhibition on thermophilic anaerobic treatment of piggery wastewater with the aim to increase organic volatile carbon reduction and methane production. A series of thermophilic anaerobic batch experiments were conducted on the digested piggery effluent to investigate the effects of pH reduction (pH 8.3 to 7.5, 7.0 and 6.5) and additions of biomass (10% v/v and 19% v/v anaerobic digested piggery biomass and aerobic-anaerobic digested municipal biomass), natural zeolite (10, 15 and 20 g/L) and humic acid (1, 5 and 10 g/L) on methane production at 55 °C for 9-11 days. Reduction of the wastewater pH from its initial pH of 8.3 to 6.5 produced the greatest stimulation of methane production (3.4 fold) coupled with reductions in free ammonia (38 fold) and total volatile fatty acids (58% TVFA), particularly acetate and propionate. Addition of 10-20 g/L zeolite to piggery wastewater with and without pH reduction to 6.5 further enhanced total VFA reduction and methane production over their respective controls, with 20 g/L zeolite producing the highest enhancement effect despite the ammonia-nitrogen concentrations of the treated wastewaters remaining high. Without pH reduction, zeolite concentration up to 20 g/L was required to achieve comparable methane enhancement as the pH-reduced wastewater at pH 6.5. Although biomass (10% v/v piggery and municipal wastes) and low humic acid (1 and 5 g/L) additions enhanced total VFA reduction and methane production, they elevated the residual effluent total COD concentrations over the control wastewaters (pH-unadjusted and pH-reduced) unlike zeolite treatment. The outcomes from these batch experiments support the use of pH reduction to 6.5 and zeolite treatment (10-20 g/L) as effective strategies to mitigate ammonia inhibition of the thermophilic anaerobic treatment of piggery wastewater.

Impaired antioxidant defence and accumulation of oxidative stress in caspase-2-deficient mice

Caspase-2 has been implicated in apoptosis and in non-apoptotic processes such as cell cycle regulation, tumor suppression and ageing. Using caspase-2 knockout (casp2(-/-)) mice, we show here that the putative anti-ageing role of this caspase is due in part to its involvement in the stress response pathway. The old casp2(-/-) mice show increased cellular levels of oxidized proteins, lipid peroxides and DNA damage, suggesting enhanced oxidative stress. Furthermore, murine embryonic fibroblasts from casp2(-/-) mice showed increased reactive oxygen species generation when challenged with pro-oxidants. Reduced activities of antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were observed in the old casp2(-/-) mice. Interestingly, in the old casp2(-/-) animals expression of FoxO1 and FoxO3a was significantly reduced, whereas p21 levels and the number of senescent hepatocytes were elevated. In contrast to young wild-type mice, the casp2(-/-) animals fed an on ethanol-based diet failed to show enhanced GSH-Px and SOD activities. Thus, caspase-2, most likely via FoxO transcription factors, regulates the oxidative stress response in vivo.

Case report of treatment resistant schizophreniaresponding to high dose quetiapine following clozapine withdrawal due to neutropenia

Introduction

Patients suffering from treatment-resistant schizophrenia pose a difficult therapeutic challenge. Although Clozapine is a well-established treatment in such cases, there is a significant proportion of patients who have to discontinue Clozapine due to life-threatening side-effects, despite achieving good therapeutic response. There is very limited literature on the therapeutic alternatives to Clozapine in the treatment of resistant schizophrenia.

Objective

To report a case of resistant schizophrenia responding to high dose Quetiapine, following discontinuation of Clozapine due to neutropenia.

Clinical details of the case: We are presenting a case of a forty-two year old female patient with treatment resistant schizophrenia who achieved remission following treatment with Clozapine, but had to discontinue treatment due to neutropenia, which occurred on two occasions. Clozapine discontinuation resulted in rapid and severe relapse in her condition and re-admission to hospital. Quetiapine was initiated as this stage, but only partial improvement was noted at the manufacturer's stated maximum daily dose of 800 mg/day. Since the drug was being well tolerated the dose was gradually further increased.

Results

The dose of Quetiapine was eventually increased up to 1400 mg/day, which produced significant response and the patient was discharged from hospital. Quetiapine at this dose was well tolerated with minimal side effects.

Conclusion

The above report indicates that high-dose Quetiapine is a viable alternative to Clozapine in treating refractory schizophrenia. The findings from this report support further investigation of this approach in the form of larger scale clinical trials.

Integrated membrane systems incorporating coagulation, activated carbon and ultrafiltration for the removal of toxic cyanobacterial metabolites from Anabaena circinalis

The use of integrated membrane systems (a train of treatment processes incorporating one or more membranes) is increasing globally as the technology is very effective for the production of high quality drinking water. In this investigation a laboratory scale integrated membrane system (IMS) featuring coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of an Australian strain of the cyanobacteria Anabaena circinalis and the cyanotoxin it produced. Three coagulants were compared, aluminium chlorohydrate (ACH), aluminium sulphate (alum) and an engineered aluminium coagulant referred to as high performance aluminium chlorohydrate (HPAC). PAC (Acticarb PS1000) was tested to determine adsorption of extracellular saxitoxin. Removal of A. circinalis cells was 100% by UF alone and the removal of cells prior to the membrane by coagulation reduced fouling attributed to algogenic organic material. Alum was the least efficient coagulant for removal of cells while ACH and HPAC were similar. Saxitoxin removal reached a maximum of 80% using ACH and PAC. The UF-IMS was challenged using a natural bloom of A. circinalis that occurred in the Myponga Reservoir in South Australia.

Nanofiltration for the removal of algal metabolites and the effects of fouling

Nanofiltration (NF) has been shown to be an effective way of removing organic micropollutants from drinking water due to its size exclusion properties. A rapid bench scale membrane test unit was utilised to trial six NF membranes to remove the algal metabolites, microcystin, cylindrospermopsin, 2-methylisoborneol (MIB) and geosmin (GSM). Membrane fouling due to the algal metabolites was observed for both charged and neutral metabolites. MIB and GSM were removed effectively by low molecular weight cut-off (MWCO) membranes but less effectively by a higher MWCO membrane. Removal of MIB and GSM by the higher MWCO membrane was improved as the membrane fouled. Microcystin was initially removed to above 90% by tight NF membranes but fouling of several membranes caused decreased percent removals over time. Tight NF membranes afforded removals of 90-100% for cylindrospermopsin, while removal by the higher MWCO membrane was lower but improved with time due to fouling.

Influence of high gas production during thermophilic anaerobic digestion in pilot-scale and lab-scale reactors on survival of the thermotolerant pathogens Clostridium perfringens and Campylobacter jejuni in piggery wastewater

Safe reuse of animal wastes to capture energy and nutrients, through anaerobic digestion processes, is becoming an increasingly desirable solution to environmental pollution. Pathogen decay is the most important safety consideration and is in general, improved at elevated temperatures and longer hydraulic residence times. During routine sampling to assess pathogen decay in thermophilic digestion, an inversely proportional relationship between levels of Clostridium perfringens and gas production was observed. Further samples were collected from pilot-scale, bench-scale thermophilic reactors and batch scale vials to assess whether gas production (predominantly methane) could be a useful indicator of decay of the thermotolerant pathogens C. perfringens and Campylobacter jejuni. Pathogen levels did appear to be lower where gas production and levels of methanogens were higher. This was evident at each operating temperature (50, 57, 65 degrees C) in the pilot-scale thermophilic digesters, although higher temperatures also reduced the numbers of pathogens detected. When methane production was higher, either when feed rate was increased, or pH was lowered from 8.2 (piggery wastewater) to 6.5, lower numbers of pathogens were detected. Although a number of related factors are known to influence the amount and rate of methane production, it may be a useful indicator of the removal of the pathogens C. perfringens and C. jejuni.

Dose-response of the cultured bovine lens to butyl, methyl and propyl parabens

Pre-screening of cosmetic ingredients is vital for consumer safety. Previous in vivo techniques, such as the Draize test, have proved to be unreliable in predicting ocular irritancy and therefore there is a need for alternate testing methodologies. One such test is the scanning laser in vitro assay system which quantifies irritancy based on the focusing ability of the cultured bovine lens. In combination with confocal microscopy, a more thorough documentation of ocular irritancy can be achieved. This study investigates the response of cultured bovine lenses over time to butyl, methyl and propyl parabens, which are common antimicrobial agents found in cosmetic and ophthalmic products. The focusing ability of the lens was measured with an automated laser scanner over a period of 96 h. At 120 h post-treatment, the lenses were analysed by using a confocal laser scanning microscope to determine the characteristics of nuclei, and the morphology and distribution of mitochondria within the lenses. Irritancy to the three parabens was investigated at both an optical and cellular level. Each of the parabens was tested at 0.002% and 0.2%, where the 0.2% butyl paraben was found to be the most irritating.

Paradoxical vocal cord dysfunction: when a wheeze is not asthma

Vocal cord dysfunction (VCD) is an uncommon condition which often mimics asthma in presentation and severity. We present nine- and 11-year-old female siblings with vocal cord dysfunction, which is a dysfunction of the larynx involving unintentional paradoxical adduction of the vocal cords during inspiration. We evaluated the use of exercise testing in conjunction with pulmonary function testing in suspected vocal cord dysfunction. Although normal pulmonology function tests were elicited with the patient at rest, exercise testing revealed blunting of the expiratory loop with attenuation of the inspiratory loop unique to VCD. The child underwent video laryngoscopy in the specialised voice clinic, which confirmed vocal cord dysfunction. Exercise testing is a rapid and noninvasive means of diagnosing vocal cord dysfunction in a small subset of patients, but video laryngoscopy, with training manoeuvres to elicit paradoxical vocal cord movements in VCD, remains the gold standard of diagnosis of VCD.

Calamine lotion: mimicking intramammary calcifications

Detection of microcalcifications is important in detecting early breast cancer. We present a case of screening mammogram in which calamine lotion mimics intramammary calcifications.

Phase I/II trial of docetaxel plus oxaliplatin and 5-fluorouracil (D-FOX) in patients with untreated, advanced gastric or gastroesophageal cancer

4612

Background: Docetaxel combined with cisplatin/5-fluouracil resulted in significantly longer time-to-progression and survival but also 30% rate of complicated neutropenia (JCO 2006; 24:4991). To improve the safety profile of docetaxel-based therapy, we studied docetaxel with oxaliplatin/5-fluorouracil (D-FOX) to establish the first-cycle MTD (phase II trial to follow). Methods: Patients with histologic proof of gastric or gastroesophageal adenocarcinoma with untreated stage IV cancer were eligible. ECOG PS of <2, near-normal organ function, and written consent were other eligibility criteria. The initial doses of oxaliplatin (85mg/m2) and 5-fluorouracil (2.2g/m2 as 48-hour infusion), given every 2 weeks, were kept constant. Docetaxel was started at 20mg/m2 (Level 1) every 2 weeks in a typical 3x3 phase I design. Subsequent levels (+5mg/m2 every 4 weeks) were added. Fatigue, incompletely treated nausea, and oxaliplatin/5-flurouracil-related toxicities were excluded to determine the MTD. Results: A total of 36 patients have been treated. Currently, docetaxel dose is 47.5mg/m2 every 2 weeks (Level 11). MTD was not reached at Level 10. Overall, grade 3 or 4 first-cycle toxicities have occurred in <5% of patients and without complicated neutropenia. Fifteen of 34 patients have had a confirmed partial response, 13 had stability, and 6 patients had progression. Conclusions: The MTD of D-FOX has not yet been established but its safety profile (D-FOX with 45mg/m2 of docetaxel every 2 weeks) is excellent and the regimen is quite active against untreated gastric or gastoresophageal cancer. Translation studies and additional clinical data will be presented. Supported in part by sanofi-aventis pharma.

[Table: see text]

The expression of FHIT, PCNA and EGFR in benign and malignant breast lesions

Immunohistochemical staining for FHIT and PCNA proteins was carried out in 451 breast lesions showing nonproliferative benign breast disease (BBD) (n=263), proliferative BBD without atypia (n=128), proliferative BBD with atypia (n=11), carcinoma in situ (n=15) or invasive carcinoma (n=34) and for EGFR protein in a subset of 71 of these cases. FHIT underexpression was not detected in nonproliferative lesions, but occurred in 2% of proliferative BBD without atypia, 10% proliferative BBD with atypia, 27% of carcinoma in situ and 41% of invasive carcinoma, which suggests that it could be useful in assessing those carcinoma in situ lesions (ductal, DCIS and lobular, LCIS) that are more likely to progress to malignancy. Preliminary microarray comparisons on DCIS and invasive carcinoma samples dissected from formalin-fixed paraffin sections showed a consistent downregulation of two previously identified FHIT-related genes, caspase 1 and BRCA1 in lesions underexpressing FHIT.

Cooperative biodegradation of geosmin by a consortium comprising three gram-negative bacteria isolated from the biofilm of a sand filter column

AIMS

To isolate and identify bacteria from a sand filter column capable of degrading the taste and odour compound, geosmin. In doing so, to investigate if these organisms degrade geosmin either individually or if an alternative mechanism is utilized.

METHODS AND RESULTS

Geosmin-degrading bacteria from a biologically active sand filter column were enriched by their growth in a minimal medium supplemented with geosmin as the sole carbon source. By day 51, 21.7 mg l(-1) of geosmin had been degraded as determined by solid-phase microextraction gas chromatography/mass spectrometry, and was accompanied by a 2.12 log(10) increase in active bacterial numbers as measured using the BacLight(TM) bacterial viability kit and flow cytometric enumeration. During the onset of geosmin degradation, the predominance of three bacteria, most similar to previously cultured species of Sphingopyxis alaskensis, Novosphingobium stygiae and Pseudomonas veronii based on 16S rRNA gene sequences was detected by denaturing gradient gel electrophoresis. Subsequent isolation of these organisms revealed that degradation of geosmin, when present as either the sole carbon source (ranging from 40 ng l(-1) to 20 mg l(-1)) or when spiked into sterile reservoir water (37 and 131 ng l(-1)), occurred only when all three isolates were present. None of the isolates was shown to be capable of degrading geosmin either individually or in any combination of two.

CONCLUSIONS

This study has reported, for the first time, the cooperative degradation of geosmin by a consortium comprising three gram-negative bacteria isolated from a biologically active sand filter column.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results are important for researchers currently employing molecular-based approaches to further understand the biodegradation of geosmin by bacteria, as such studies may be complicated by the discovery of geosmin degradation occurring by a consortium. This study also advances the knowledge surrounding the types of bacteria capable of degrading the taste and odour compound, as investigations to date regarding this are limited.

Quinine-induced renal failure as a result of rhabdomyolysis, haemolytic uraemic syndrome and disseminated intravascular coagulation

This report describes a case of quinine-induced acute renal failure as a result of a combination of haemolytic uraemic syndrome and rhabdomyolysis with disseminated intravascular coagulation. The abrupt onset of symptoms occurred after ingestion of 300 mg of quinine along with atorvastatin. The patient recovered with supportive management, suggesting that plasma exchange may not be necessary in this situation. The possibility of a drug interaction contributing to rhabdomyolysis is raised. The proposed mechanism is through quinine inhibition of the cytochrome P450 isoenzyme 3A4, which may increase systemic levels of atorvastatin by reducing its first-pass metabolism.

Elevated multidrug resistance-associated protein 4 (MRP4) expression in localized prostate cancer—A potential androgen regulated protein

20022

Background: MRP4 is an ATP-binding cassette transporter and amphipathic anion efflux pump which transports prostaglandins, nucleoside analogues, glutamate and phosphate analogues. High MRP4 expression is prognostic of poor outcome in neuroblastoma and also correlates with MYCN amplification, suggesting regulation by this oncogene. Although MRP4 is known to be expressed in normal prostate epithelium, its expression in prostate cancer (PC) is undefined. This study aimed to define the pattern of expression of MRP4 in normal and malignant prostate tissue and assess the association with androgen exposure. Methods: 84 radical prostatectomy specimens from patients with clinically localized PC (22 neoadjuvant androgen ablation therapy, 62 no neoadjuvant treatment), 42 specimens of hyperplasia adjacent to PC and 16 cases of advanced PC were assessed for MRP4 expression using in situ hybridisation and immunohistochemistry. PC cell lines were assessed by immunoblotting. Results: There were significantly higher levels of MRP4 mRNA and protein expression in localized PC compared to hyperplasia (p=0.006). Conversely, MRP4 protein levels were significantly decreased in PCs treated with neoadjuvant androgen ablation therapy compared to cancers exposed to normal testosterone levels (p < 0.0001). There was also a trend towards decreased MRP4 expression in advanced PCs. Furthermore, immunoblotting revealed that MRP4 protein was more highly expressed in androgen-dependent (LNCaP) compared to androgen-independent (PC3/DU145) cell lines. In addition, in a panel of 14 normal human tissues only kidney and prostate tissue expressed MRP4 protein suggesting limited expression of MRP4 in human tissues. Discussion: Elevated MRP4 expression is found in malignant compared to benign prostate tissue while lower MRP4 expression is seen after androgen ablation suggesting that MRP4 may be an androgen-regulated gene. In addition, there is relatively little expression of MRP4 in normal tissues. These data suggest that MRP4 is important in the progression to PC and that it may be a potential therapeutic target.

No significant financial relationships to disclose.

Neoadjuvant chemotherapy improves outcomes of chemoradiation therapy for locally advanced pancreatic cancer

4036

Background: Two-thirds of all pancreatic cancer patients have radiographically detectable metastatic disease at the time of diagnosis. Most of the remaining patients have locally advanced, unresectable disease that is typically treated with either chemoradiation or chemotherapy alone. We explored the possible benefit of the use of consolidative chemoradiation after induction chemotherapy. Methods: Between December 1993 and October 2005, 318 patients with locally advanced, non-metastatic, pancreatic cancer were treated at our institution with concurrent chemoradiation therapy. All patients underwent CT staging and biopsy confirmed adenocarcinoma. 245 patients received chemoradiation (CR) as initial treatment while 73 patients received a median of 2.5 months of induction chemotherapy prior to chemoradiation (CCR). Radiosensitizers included 5FU (42%), gemcitabine (39%) and capecitabine (19%) and most patients (88%) received 30 Gy of radiation therapy. The most common induction chemotherapy regimens were gemcitabine and cisplatin (73%) and gemcitabine alone (15%). Results: All statistics are actuarial and calculated from date of initial treatment. Median follow-up was 5.5 months (range 1–63 months). For all patients, overall survival was 9.0 months and 2-year survival was 8%. Age, gender, histology, grade, radiation fractionation and concurrent chemotherapy regimen had no impact on outcomes on univariate analysis. However, overall survival was 8.5 months in the CR group and 11.9 months in the CCR group (p = 0.0004). Median time to local progression was 6.0 months in the CR group and 8.4 in the CCR group (p = 0.0055). Median time to distant progression was 5.8 months in the CR group and 9.5 months in the CCR group (p=0.0136). Conclusions: In one of the largest series of locally advanced pancreatic cancer patients, the use of induction chemotherapy followed by chemoradiation seems to prolong median survival over initial treatment with chemoradiation. By excluding patients who progress rapidly during induction chemotherapy, this approach presumably selects patients most likely to benefit from a local treatment modality. This strategy merits prospective evaluation.

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Identification of potential CSF biomarkers in ALS

BACKGROUND

The clinical diagnosis of ALS is based entirely on clinical features. Identification of biomarkers for ALS would be important for diagnosis and might also provide clues to pathogenesis.

OBJECTIVE

To determine if there is a specific protein profile in the CSF that distinguishes patients with ALS from those with purely motor peripheral neuropathy (PN) and healthy control subjects.

METHODS

CSF obtained from patients with ALS, disease controls (patients with other neurologic disorders), and normal controls were analyzed using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry proteomics technique. Biomarker sensitivity and specificity was calculated with receiver operating characteristic curve methodology. ALS biomarkers were purified and sequence identified by mass spectrometry-directed peptide sequencing.

RESULTS

In initial proteomic discovery studies, three protein species (4.8-, 6.7-, and 13.4-kDa) that were significantly lower in concentration in the CSF from patients with ALS (n = 36) than in normal controls (n = 21) were identified. A combination of three protein species (the "three-protein" model) correctly identified patients with ALS with 95% accuracy, 91% sensitivity, and 97% specificity from the controls. Independent validation studies using separate cohorts of ALS (n = 13), healthy control (n = 25), and PN (n = 7) subjects confirmed the ability of the three CSF protein species to separate patients with ALS from other diseases. Protein sequence analysis identified the 13.4-kDa protein species as cystatin C and the 4.8-kDa protein species as a peptic fragment of the neurosecretory protein VGF.

CONCLUSION

Additional application of a "three-protein" biomarker model to current diagnostic criteria may provide an objective biomarker pattern to help identify patients with ALS.

Inhibition of cyclooxygenase as potential novel therapeutic strategy in N141I presenilin-2 familial Alzheimer's disease

The present study was designed to further explore the potential cause/effect relationship between the expression of both the N141I presenilin (PS)2 mutant familial Alzheimer's disease (FAD) gene and cyclooxgenase (COX) in respect to the mechanism associated with programmed cell death in Alzheimer's disease (AD). We found that expression of mutant N141I PS2 resulting in apoptotic cell death in H4 neuronal cells coincided with >4-fold induction in the expression of the inducible form of COX-2, but not the constitutive COX-1. Moreover, we found that the expression of the N141I PS2 FAD gene strongly promoted (>2-fold) glycogen synthase kinase (GSK)-3beta activity coincidental with a reduction in the level of beta-catenin translocated from the cytoplasmic to the nuclear compartment. Most interestingly, we found that inhibition of COX-2-mediated generation of prostaglandin (PG)-E2 in H4 neuronal cells with the preferential COX-2 inhibitor nimesulide protects against N141I PS2-mediated apoptotic cell death coincidental with an inhibition of GSK-3beta activity and subsequent normalization of beta-catenin cellular distribution. The clinical relevance of this finding was confirmed by the evidence that COX-2 protein and PG-E2 concentrations were selectively increased >2-fold in the cerebral cortex of subjects harboring the N141I PS2 FAD mutation relative to wild-type PS2 AD cases. This study demonstrates for the first time that COX-2 may be a downstream effector of mutant N141I PS2-mediated apoptotic cell death and that inhibition of COX-2 may neuroprotect in AD through modulation of a GSK-3beta-beta-catenin-mediated response. The study provides support for the potential pharmacogenomic identification of N141I PS2 FAD cases that might preferentially benefit from inhibition of COX-2 during the progression of clinical dementia.