Cerebral glucose metabolism and cognition in newly diagnosed Parkinson's disease: ICICLE-PD study.

OBJECTIVE: To assess reductions of cerebral glucose metabolism in Parkinson's disease (PD) with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), and their associations with cognitive decline. METHODS: FDG-PET was performed on a cohort of 79 patients with newly diagnosed PD (mean disease duration 8 months) and 20 unrelated controls. PD participants were scanned while on their usual dopaminergic medication. Cognitive testing was performed at baseline, and after 18 months using the Cognitive Drug Research (CDR) and Cambridge Neuropsychological Test Automated Battery (CANTAB) computerised batteries, the Mini-Mental State Examination (MMSE), and the Montreal Cognitive Assessment (MoCA). We used statistical parametric mapping (SPM V.12) software to compare groups and investigate voxelwise correlations between FDG metabolism and cognitive score at baseline. Linear regression was used to evaluate how levels of cortical FDG metabolism were predictive of subsequent cognitive decline rated with the MMSE and MoCA. RESULTS: PD participants showed reduced glucose metabolism in the occipital and inferior parietal lobes relative to controls. Low performance on memory-based tasks was associated with reduced FDG metabolism in posterior parietal and temporal regions, while attentional performance was associated with more frontal deficits. Baseline parietal to cerebellum FDG metabolism ratios predicted MMSE (ß=0.38, p=0.001) and MoCA (ß=0.3, p=0.002) at 18 months controlling for baseline score. CONCLUSIONS: Reductions in cortical FDG metabolism were present in newly diagnosed PD, and correlated with performance on neuropsychological tests. A reduced baseline parietal metabolism is associated with risk of cognitive decline and may represent a potential biomarker for this state and the development of PD dementia.

The synergistic interaction of MEK and PI3K inhibitors is modulated by mTOR inhibition.

BACKGROUND: Combined targeting of MAPK and PI3K signalling pathways may be necessary for optimal therapeutic activity in cancer. This study evaluated the MEK inhibitors AZD6244 and PD0325901, alone and in combination with the dual mTOR/PI3K inhibitor NVP-BEZ235 or the PI3K inhibitor GDC-0941, in three colorectal cancer cell lines. METHODS: Growth inhibition, survival and signal transduction were measured using the Sulforhodamine B assay, clonogenicity and western blotting, respectively, in HCT116, HT29 and DLD1 cell lines. RESULTS: All MEK/PI3K inhibitor combinations exhibited marked synergistic growth inhibition; however, GDC-0941 displayed greater synergy in combination with either MEK inhibitor. NVP-BEZ235 exhibited stronger inhibition of 4EBP1 phosphorylation, and similar inhibition of S6 and AKT phosphorylation, compared with GDC-0941. Both PD0325901 and AZD6244 inhibited ERK phosphorylation, and with MEK/PI3K inhibitor combinations inhibition of S6 phosphorylation was increased. The reduced synergy exhibited by NVP-BEZ235 in combination with MEK inhibitors, compared with GDC-0941, may be due to inhibition of mTOR, and the addition of the mTORC1/2 inhibitor KU0063794 compromised the synergy of GDC-0941:PD0325901 combinations. CONCLUSION: These studies confirm that dual targeting of PI3K and MEK can induce synergistic growth inhibition; however, the combination of specific PI3K inhibitors, rather than dual mTOR/PI3K inhibitors, with MEK inhibitors results in greater synergy.

Rationale for cancer prevention strategies in high-risk ulcerative colitis.

Colorectal cancer (CRC) is the most feared long-term complication in patients with ulcerative colitis (UC) and Crohn's colitis. Surveillance by colonoscopy and serial biopsy is conducted to identify patients most likely to benefit from potentially curative surgery. Within this paradigm, patients with high grade dysplasia or early stage CRC typically undergo colectomy, while patients free of dysplasia continue within surveillance programmes. However, detection of dysplasia in colitis may be difficult. Underdiagnosis and undertreatment of dysplasia may be accompanied by 'interval cancers' after apparently negative colonoscopy, frustrating the goal of cancer prevention. In the absence of a best practice model, surgical decisions for effective cancer prevention and control can be aided by greater understanding of cancer biology, in particular the close relationship between processes of inflammation and neoplastic change. This review will summarise recent knowledge in this area and consider clinical variables of disease duration, severity and anti-inflammatory therapy against stepwise events of neoplastic transformation. Against this background, indications for surveillance and prophylactic colectomy in specific clinical situations will be discussed.

Carbogen breathing increases prostate cancer oxygenation: a translational MRI study in murine xenografts and humans.

Hypoxia has been associated with poor local tumour control and relapse in many cancer sites, including carcinoma of the prostate. This translational study tests whether breathing carbogen gas improves the oxygenation of human prostate carcinoma xenografts in mice and in human patients with prostate cancer. A total of 23 DU145 tumour-bearing mice, 17 PC3 tumour-bearing mice and 17 human patients with prostate cancer were investigated. Intrinsic susceptibility-weighted MRI was performed before and during a period of carbogen gas breathing. Quantitative R(2)* pixel maps were produced for each tumour and at each time point and changes in R(2)* induced by carbogen were determined. There was a mean reduction in R(2)* of 6.4% (P=0.003) for DU145 xenografts and 5.8% (P=0.007) for PC3 xenografts. In all, 14 human subjects were evaluable; 64% had reductions in tumour R(2)* during carbogen inhalation with a mean reduction of 21.6% (P=0.0005). Decreases in prostate tumour R(2)* in both animal models and human patients as a result of carbogen inhalation suggests the presence of significant hypoxia. The finding that carbogen gas breathing improves prostate tumour oxygenation provides a rationale for testing the radiosensitising effects of combining carbogen gas breathing with radiotherapy in prostate cancer patients.

The assessment of antiangiogenic and antivascular therapies in early-stage clinical trials using magnetic resonance imaging: issues and recommendations.

Vascular and angiogenic processes provide an important target for novel cancer therapeutics. Dynamic contrast-enhanced magnetic resonance imaging is being used increasingly to noninvasively monitor the action of these therapeutics in early-stage clinical trials. This publication reports the outcome of a workshop that considered the methodology and design of magnetic resonance studies, recommending how this new tool might best be used.

Colonic malignancy arising in colitis - a single unit experience.

OBJECTIVES: Colorectal malignancy complicating inflammatory bowel disease constitutes 1% of all colorectal malignancies. Although its overall numbers are low it represents the greatest cause of colitis related mortality in these patients. This paper describes the management of 24 patients presenting to a single unit over a period of 10 years. METHODS: The names of patients were collected prospectively when they presented with malignancy. Clinical details were collected by retrospective review of charts. RESULTS: In all, 24 patients with 27 malignancies were identified. The median age of presentation with malignancy was 56 years. Most patients were treated with proctocolectomy. Other patients were treated with segmental colectomy. In these patients the surgical procedure was dictated by the stage of the cancer, the age and comorbid state of the patient and the severity of ongoing colitis. CONCLUSIONS: Malignancy arising in colitis will constitute only a small part of a colorectal practice. The optimum method for detecting early, and potentially curable, disease has not been defined. Surgery should be tailored to the individual needs of the patient.

Effect of changing tumor oxygenation on glycolytic metabolism in a murine C3H mammary carcinoma assessed by in vivo nuclear magnetic resonance spectroscopy.

The rate of conversion of D-[1-(13)C]glucose into [3-(13)C]lactate (apparent glycolytic rate) has been determined in C3H murine mammary carcinomas in vivo using tumor-selective (13)C nuclear magnetic resonance spectroscopy with (1)H-(13)C cross-polarization. Under conditions of acute hypoxia induced by breathing carbon monoxide at 660 ppm, the apparent glycolytic rate was 0.0239 +/- 0.0019 min(-1). The proportion of (13)C label incorporated into [4-(13)C]glutamate (measured in tumor extracts) was 25-fold lower than that incorporated into [3-(13)C]lactate, reflecting a very limited oxidative metabolism during this hypoxic episode. For animals breathing air or carbogen (95% O(2) + 5% CO(2)), the calculated glycolytic rates were correspondingly lower (0.0160 +/- 0.0021 min(-1) and 0.0050 +/- 0.0011 min(-1), respectively). Although (13)C labeling of glutamate at C4 was still an order of magnitude lower than that for lactate at C3 (11-fold for air and 9-fold for carbogen), these ratios did show a greater degree of oxidative metabolism than that seen in animals breathing carbon monoxide at 660 ppm. The marked difference in apparent glycolytic rate for this tumor model between well-oxygenated and hypoxic conditions demonstrates a substantial Pasteur effect (inhibition of glycolysis by oxygen). Dynamic (13)C nuclear magnetic resonance spectroscopy provides a noninvasive estimate of tumor glycolysis that can be used to evaluate the relationship between oxygenation and energy metabolism, and this has potential consequences for the sensitivity of hypoxic cells to treatment and their ability to promote angiogenesis.

Combretastatins novel vascular targeting drugs for improving anti-cancer therapy. Combretastatins and conventional therapy.

Combretastatins are a new class of compounds that appear to have anti-tumour activity as a result of specifically targeting the vasculature of tumours. The aim of this study was to investigate the potential of combretastatin A-4 disodium phosphate (CA4DP) to induce vascular effects in a C3H mouse mammary carcinoma, and to see if the anti-tumour response could be improved by combining the drug with conventional anti-cancer therapies. It was found that CA4DP (250 mg/kg) significantly decreased tumour perfusion within 30 minutes after injection and maintained this decrease for several hours, although there was a return to normal by 24 hours. Similar changes were seen in the tumours bioenergetic and oxygenation status. The drug also significantly increased tumour necrosis and had a small inhibitory effect on tumour growth. It was also able to enhance the tumour response to radiation and hyperthermia, when given at the same time or 30 minutes after the radiation and hyperthermia, respectively. Giving the drug 1 hour after cisplatin injection only resulted in a tumour response that was no greater than additive. These results confirm the anti-vascular effects of CA4DP and demonstrate its potential to enhance the anti-tumour activity of conventional therapy.

Applications of magnetic resonance in model systems: cancer therapeutics.

The lack of information regarding the metabolism and pathophysiology of individual tumors limits, in part, both the development of new anti-cancer therapies and the optimal implementation of currently available treatments. Magnetic resonance [MR, including magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and electron paramagnetic resonance (EPR)] provides a powerful tool to assess many aspects of tumor metabolism and pathophysiology. Moreover, since this information can be obtained nondestructively, pre-clinical results from cellular or animal models are often easily translated into the clinic. This review presents selected examples of how MR has been used to identify metabolic changes associated with apoptosis, detect therapeutic response prior to a change in tumor volume, optimize the combination of metabolic inhibitors with chemotherapy and/or radiation, characterize and exploit the influence of tumor pH on the effectiveness of chemotherapy, characterize tumor reoxygenation and the effects of modifiers of tumor oxygenation in individual tumors, image transgene expression and assess the efficacy of gene therapy. These examples provide an overview of several of the areas in which cellular and animal model studies using MR have contributed to our understanding of the effects of treatment on tumor metabolism and pathophysiology and the importance of tumor metabolism and pathophysiology as determinants of therapeutic response.

Non-invasive tumour blood perfusion measurement by 2H magnetic resonance.

Deuterium uptake into foot-implanted C3H murine mammary carcinomas was measured non-invasively by 2H NMR spectroscopy at 46 MHz after i.v. injection. The arterial input function (AIF) was estimated from 2H NMR measurements with a second radiofrequency coil externally located over the heart. Tumour and heart data were acquired over the same time period by means of a switch automatically activated every 1.6-3.2 s. Although the AIF data were, in general, partly contaminated by signals from adjacent tissue, a mathematical fitting procedure involving simultaneous fitting of the AIF and the tumour kinetics gave robust results for tumour blood perfusion (TBP): up to four repeat TBP measurements were made in 14 out of 20 untreated animals and TBP could be measured before and after treatment in 14 out of 15 animals. The ability of this technique to measure changes in blood perfusion was assessed using hydralazine, which decreased TBP from 91 to 29 ml 100 g(-1) min(-1) and this was comparable to a 70% reduction in relative TBP measured by laser Doppler flowmetry.

Systemic vasculitis and aneurysm formation in the Wiskott-Aldrich syndrome.

A 24 year old male who suffered from the Wiskott-Aldrich syndrome developed intra-abdominal bleeding on two occasions. Radiological investigations showed aneurysmal dilatation of branches of the hepatic and superior mesenteric arteries. The second abdominal bleed necessitated laparotomy and the bleeding was localised to the kidneys. Right nephrectomy was performed and histological examination showed a necrotising vasculitis, mainly involving medium and small sized renal blood vessels. Steroids, immunosuppressive treatment, and control of blood pressure resulted in resolution of the vasculitic process and prevented further haemorrhage. Vasculitis and aneurysm formation are rarely described complications of Wiskott-Aldrich syndrome and may account for the life threatening haemorrhage which occurs in this condition.

Determination of sarafloxacin residues in fortified and incurred eggs using on-line microdialysis and HPLC/programmable fluorescence detection.

Isolation of sarafloxacin (SAR) from fortified and incurred chicken eggs was done by a combination of liquid-liquid extraction and aqueous on-line microdialysis performed on an automated trace enrichment of dialysates (ASTED) system. The ASTED system coupled a sample cleanup procedure with HPLC and programmable fluorescence detection. Overall recoveries of 87-102% for SAR were obtained from samples fortified over a range of 1-100 ng/g. The relative standard deviation values ranged from 22 to 26% for samples fortified between 1 and 5 ng/g and from 2 to 12% for samples fortified between 10 and 100 ng/g. The limits of detection and quantitation were 0.2 and 1 ng/g, respectively. Eggs containing incurred SAR, which were collected over a 3-day dosing period and for 5 consecutive days thereafter, also were analyzed by using this technique. Because the method is automated, 35 samples can be processed within a 24-h period, which enables large data sets to be acquired over a short time period.

A comparison of DNA damage in testicular and proximal epididymal spermatozoa in obstructive azoospermia.

Testicular and epididymal spermatozoa are used routinely for intracytoplasmic sperm injection (ICSI) to treat men with obstructive azoospermia. Little is known of the effects of obstruction and stasis on the DNA of these spermatozoa, particularly in the epididymis where spermatozoa have been retained for long periods. Surgical epididymal aspiration for ICSI could provide spermatozoa that are senescent or dying. Using the Comet assay, the percentage of undamaged DNA of testicular spermatozoa from 20 men with obstructive azoospermia was significantly better (83.0 +/- 1. 2%) than from proximal epididymal spermatozoa (75.4 +/- 2.3%; P < 0. 05). There was no difference between the percentage of undamaged DNA of testicular spermatozoa from 39 men with obstructive azoospermia (84.0 +/- 0.9) or from 10 fertile men at vasectomy (86.8 +/- 1.8) or from ejaculated spermatozoa from five of the controls (78.9 +/- 3.9; P > 0.05). In nine subjects, a second biopsy was carried out 6 months later. There was no significant difference in undamaged DNA on these two occasions (83.5 +/- 5.6 and 84.1 +/- 4.2; P > 0.05). This confirms the reproducibility of the Comet assay for non-ejaculated spermatozoa. Our data suggest that testicular sperm DNA appears to be significantly less damaged than epididymal sperm DNA, and so testicular spermatozoa should be used in preference for ICSI to treat men with obstructive azoospermia.

Localized in vivo 1H NMR spectroscopy of murine tumours: effect of blood flow reduction.

Single voxel 1H localized spectroscopy (PRESS at 300 MHz) was used to monitor physiological and biochemical changes induced by hydralazine (5 mg/kg, i.p.) in murine C3H mammary tumours. In addition to a significant increase (by 52%, maximal at 30 min) in the intensity of the 1.32 ppm signal (predominantly from lactate, consistent with a selective reduction in tumour blood supply by hydralazine), downfield shifts in the resonance frequencies of 1H signals were observed. In particular, the signal initially at 3.24 ppm (total choline, tCho) shifted by 0.050 ppm (maximal at 13 min), whereas water shifted by 0.086 ppm. Lactate intensity and water and tCho resonance frequencies returned to control values at approximately 100 min after treatment. No significant changes in the resonance frequencies of water or tCho were observed over this time period in the tumours of mice given saline. In vitro studies showed that, while the resonance frequency of water was temperature dependent, the main components of the tCho signal (choline, phosphorylcholine and glycerophosphorylcholine) were more than 30-fold less sensitive to temperature. It was concluded that the shift in the water resonance frequency was due to the combined effects of tumour temperature reduction and a paramagnetic shift from increased deoxyhaemoglobin levels, whereas the tCho signal was only affected by the paramagnetic shifts.

Supercritical fluid extraction of methyltestosterone, nortestosterone and testosterone at low ppb levels from fortified bovine urine.

A multi-residue supercritical fluid extraction (SFE) method is proposed for the isolation of nortestosterone, testosterone and methyltestosterone from bovine urine. Prior to SFE, bovine urine was hydrolyzed and then fortified with the three steroids at 100 ng/ml and 50 ng/ml each for HPLC analysis and 25 ng/ml and 12.5 ng/ml each for GC-MS analysis. The samples then were mixed with an adsorbent material, placed in an SFE extraction vessel prepacked with a 3-ml SPE column containing neutral alumina and the testosterones were extracted from the urine matrix using unmodified supercritical CO2 at 27.2 MPa and 40 degrees C. The steroids were retained in-line on the neutral alumina sorbent in the SPE column while co-extracted artifactial material was trapped off-line after CO2 decompression. After SFE, the SPE column was removed from the extraction vessel, and the trapped steroids were eluted from the neutral alumina sorbent with 3 ml of a methanol-water mixture. Eluates were used directly without post-SFE clean-up either for HPLC analysis (detection limit 50 ng/ml) or for GC-MS analysis (detection limit 5 ng/ml after steroid derivatization). The multi-residue SFE recoveries (n=6) for nortestosterone, testosterone and methyltestosterone from hydrolyzed bovine urine by GC-MS analysis were 90.8+/-6%, 93.9+/-3% and 92.5+/-5%, respectively for each steroid at the 12.5 ng fortification level.

Automated multi-residue isolation of fluoroquinolone antimicrobials from fortified and incurred chicken liver using on-line microdialysis and high-performance liquid chromatography with programmable fluorescence detection.

Isolation of the quinolones, sarafloxacin (SAR), oxolinic acid (OXA), and flumequine (FMQ), from fortified chicken liver tissues, and SAR incurred chicken liver tissues was achieved by combined liquid-liquid extraction and aqueous on-line microdialysis using the automated trace enrichment of dialysates (ASTED) system. Analysis of tissue isolates after ASTED clean-up was performed using reversed-phase HPLC and programmable fluorescence detection. Overall recoveries of SAR, OXA and FMQ from samples fortified over a concentrations range of 1-100 ppb were 94, 97 and 87% with overall inter-assay variability of 4.2, 4.1 and 3.6%, respectively. Chicken liver samples incurred with SAR at three concentration levels also were tested by the ASTED method. The method exhibited high peak resolution (3.4-4.2 on average), a high signal-to-noise ratio, and demonstrated good precision. The ASTED-HPLC method overall had a lower limit of detection (LOD) of 0.2 ppb, and a limit of quantitation (LOQ) of 1 ppb.

Effects of combretastatin on murine tumours monitored by 31P MRS, 1H MRS and 1H MRI.

PURPOSE: Combretastatins have tubulin-binding activity and are being investigated for their toxicity against tumour vasculature. We report the use of 31P and 'H magnetic resonance (MR) spectroscopy and 1H MR imaging for monitoring the effects of combretastatin A-4 prodrug (100mg/kg, i.p.) on energy metabolism and necrosis, respectively, in the C3H murine mammary tumour. MATERIALS AND METHODS: The tumours (volume ca. 200mm3) were grown in the hind foot of mice. MR examinations were performed without anaesthesia within a 7.1 Tesla magnet. 31P MRS (TR = 6 s) was performed before treatment and at 1-, 2-, 3-, and 24-h after injection of drug or saline via an i.p. line. 1H MRS (PRESS; 24microl voxel; TR = 2 s; TE = 135 ms) and both T1-weighted (TR = 0.2 s; TE = 0.02 s) and T2-weighted (TR = 2 s; TE = 0.20 s) 1H MRI were performed before treatment and 2.5 and 24 h afterwards. RESULTS: The ratio beta-nucleotide triphosphate/inorganic phosphate fell by 33% within 1 h of treatment and remained constant for a further 2 h. A small but significant fall in pH (by 0.11 units) was observed at 1 h. Although an increase in the 1H MR spectroscopy signal at about 1.32 ppm (predominantly from lactate) was observed in some tumours following combretastatin treatment, this effect was not seen consistently. No changes in the intensity of T2-weighted 1H MR images or in tumour necrosis (measured histologically) were detected within 3 h of treatment. CONCLUSIONS: The reduction in tumour energetics and pH was consistent with a reduction in tumour blood flow but this occurred before any significant incidence of haemorrhagic necrosis was detected. The combretastatin dose used to achieve these effects was less than one tenth of the maximum tolerated dose in mice.

Multiresidue supercritical fluid extraction method for the recovery at low ppb levels of three sulfonamides from fortified chicken liver.

A supercritical fluid extraction (SFE) method is proposed for the recovery of three sulfonamides from chicken liver. Samples were extracted at 680 bar and 40 degrees C using unmodified carbon dioxide and were collected free of co-extracted artifactual material on an in-line neutral alumina sorbent bed. High recoveries of sulfamethazine (SMZ), sulfadimethoxine (SDM) and sulfaquinoxaline (SQX) were obtained from chicken liver samples fortified at levels from 1000 to 50 ppm.