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1.  SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair 
Oncogene  2015;34(46):5699-5708.
Defining mechanisms that generate intratumour heterogeneity and branched evolution may inspire novel therapeutic approaches to limit tumour diversity and adaptation. SETD2 (Su(var), Enhancer of zeste, Trithorax-domain containing 2) trimethylates histone-3 lysine-36 (H3K36me3) at sites of active transcription and is mutated in diverse tumour types, including clear cell renal carcinomas (ccRCCs). Distinct SETD2 mutations have been identified in spatially separated regions in ccRCC, indicative of intratumour heterogeneity. In this study, we have addressed the consequences of SETD2 loss-of-function through an integrated bioinformatics and functional genomics approach. We find that bi-allelic SETD2 aberrations are not associated with microsatellite instability in ccRCC. SETD2 depletion in ccRCC cells revealed aberrant and reduced nucleosome compaction and chromatin association of the key replication proteins minichromosome maintenance complex component (MCM7) and DNA polymerase δ hindering replication fork progression, and failure to load lens epithelium-derived growth factor and the Rad51 homologous recombination repair factor at DNA breaks. Consistent with these data, we observe chromosomal breakpoint locations are biased away from H3K36me3 sites in SETD2 wild-type ccRCCs relative to tumours with bi-allelic SETD2 aberrations and that H3K36me3-negative ccRCCs display elevated DNA damage in vivo. These data suggest a role for SETD2 in maintaining genome integrity through nucleosome stabilization, suppression of replication stress and the coordination of DNA repair.
doi:10.1038/onc.2015.24
PMCID: PMC4660036  PMID: 25728682
2.  Academically led clinical trials: challenges and opportunities 
Annals of Oncology  2015;26(10):2010-2011.
doi:10.1093/annonc/mdv332
PMCID: PMC4576911  PMID: 26240217
3.  Curative surgical management of isolated adrenal recurrence of oesophageal adenocarcinoma 
BMJ Case Reports  2013;2013:bcr2013009657.
Adrenal metastases of oesophageal adenocarcinoma are rarely detected in the clinical setting, more frequently being found as an incidental postmortem finding in the presence of widespread metastases. With improvements in the sensitivity of radiological diagnostic modalities, the incidence of adrenal tumour detection is on the rise. We report herein a particularly rare case of primary operative management by adrenalectomy for an isolated right-sided adrenal metastasis secondary to oesophageal adenocarcinoma, with a long-term survival.
doi:10.1136/bcr-2013-009657
PMCID: PMC3645837  PMID: 23632191
4.  Necrotising pancreatitis presenting as a painful mass in the groin and sepsis 
BMJ Case Reports  2013;2013:bcr2013008726.
Acute pancreatitis is typically associated with classical clinical and radiological features. The sensitivity of CT to diagnose acute pancreatitis depends on the severity of the attack and ranges from 77% to 92% with a specificity approaching 100%. Despite the fact this is a common disease, there are myriad clinical presentations of acute pancreatitis. We report herein an especially rare presentation where severe acute necrotising pancreatitis presented with a tender inguinoscrotal swelling with a normal pancreas on CT imaging.
doi:10.1136/bcr-2013-008726
PMCID: PMC3645122  PMID: 23625666
5.  Efficacy and safety of sunitinib in elderly patients with metastatic renal cell carcinoma 
British Journal of Cancer  2014;110(5):1125-1132.
Background:
We retrospectively analyzed sunitinib outcome as a function of age in metastatic renal cell carcinoma (mRCC) patients.
Methods:
Data were pooled from 1059 patients in six trials. Kaplan–Meier estimates of progression-free survival (PFS) and overall survival (OS) were compared by log-rank test between patients aged <70 (n=857; 81%) and ⩾70 (n=202; 19%) years.
Results:
In first-line patients, median PFS was comparable in younger and older patients, 9.9 vs 11.0 months, respectively (HR, 0.89; 95% CI: 0.73–1.09; P=0.2629), as was median OS, 23.6 vs 25.6 months (HR, 0.93; 95% CI: 0.74–1.18; P=0.5442). Similarly, in cytokine-refractory patients, median PFS was 8.1 vs 8.4 months (HR, 0.79; 95% CI: 0.49–1.28; P=0.3350), while median OS was 20.2 vs 15.8 months (HR, 1.14; 95% CI: 0.73–1.79; P=0.5657). Some treatment-emergent adverse events were significantly less common in younger vs older patients, including fatigue (60% vs 69%), cough (20% vs 29%), peripheral edema (17% vs 27%), anemia (18% vs 25%), decreased appetite (13% vs 29%), and thrombocytopenia (16% vs 25% all P<0.05). Hand–foot syndrome was more common in younger patients (32% vs 24%).
Conclusions:
Advanced age should not be a deterrent to sunitinib therapy and elderly patients may achieve additional clinical benefit.
doi:10.1038/bjc.2013.832
PMCID: PMC3950861  PMID: 24434434
sunitinib; renal cell carcinoma; metastatic; age; retrospective analysis
6.  Changes in tumour vessel density upon treatment with anti-angiogenic agents: relationship with response and resistance to therapy 
British Journal of Cancer  2013;109(5):1230-1242.
Background:
We examine how changes in a surrogate marker of tumour vessel density correlate with response and resistance to anti-angiogenic therapy.
Methods:
In metastatic renal cancer patients treated with anti-angiogenic tyrosine kinase inhibitors, arterial phase contrast-enhanced computed tomography was used to simultaneously measure changes in: (a) tumour size, and (b) tumour enhancement (a surrogate marker of tumour vessel density) within individual lesions.
Results:
No correlation between baseline tumour enhancement and lesion shrinkage was observed, but a reduction in tumour enhancement on treatment was strongly correlated with reduction in lesion size (r=0.654, P<0.0001). However, close examination of individual metastases revealed different types of response: (1) good vascular response with significant tumour shrinkage, (2) good vascular response with stabilisation of disease, (3) poor vascular response with stabilisation of disease and (4) poor vascular response with progression. Moreover, contrasting responses between different lesions within the same patient were observed. We also assessed rebound vascularisation in tumours that acquired resistance to treatment. The amplitude of rebound vascularisation was greater in lesions that had a better initial response to therapy (P=0.008).
Interpretation:
Changes in a surrogate marker of tumour vessel density correlate with response and resistance to anti-angiogenic therapy. The data provide insight into the mechanisms that underlie response and resistance to this class of agent.
doi:10.1038/bjc.2013.429
PMCID: PMC3778288  PMID: 23922108
angiogenesis; metastasis; tyrosine kinase inhibitor; resistance; renal cell carcinoma
7.  Whole-genome sequencing reveals complex mechanisms of intrinsic resistance to BRAF inhibition 
Annals of Oncology  2014;25(5):959-967.
We used a combination of whole-genome sequencing and in vitro validation to show that mutations that activated at least two pro-growth/survival pathways mediated intrinsic resistance to BRAF inhibition in a melanoma patient. These data demonstrate how in-depth analysis can reveal intrinsic resistance to standard of care, providing an opportunity for alternative therapeutic strategies for patients who are likely to fail first-line treat-575 ment.
Background
BRAF is mutated in ∼42% of human melanomas (COSMIC. http://www.sanger.ac.uk/genetics/CGP/cosmic/) and pharmacological BRAF inhibitors such as vemurafenib and dabrafenib achieve dramatic responses in patients whose tumours harbour BRAFV600 mutations. Objective responses occur in ∼50% of patients and disease stabilisation in a further ∼30%, but ∼20% of patients present primary or innate resistance and do not respond. Here, we investigated the underlying cause of treatment failure in a patient with BRAF mutant melanoma who presented primary resistance.
Methods
We carried out whole-genome sequencing and single nucleotide polymorphism (SNP) array analysis of five metastatic tumours from the patient. We validated mechanisms of resistance in a cell line derived from the patient's tumour.
Results
We observed that the majority of the single-nucleotide variants identified were shared across all tumour sites, but also saw site-specific copy-number alterations in discrete cell populations at different sites. We found that two ubiquitous mutations mediated resistance to BRAF inhibition in these tumours. A mutation in GNAQ sustained mitogen-activated protein kinase (MAPK) signalling, whereas a mutation in PTEN activated the PI3 K/AKT pathway. Inhibition of both pathways synergised to block the growth of the cells.
Conclusions
Our analyses show that the five metastases arose from a common progenitor and acquired additional alterations after disease dissemination. We demonstrate that a distinct combination of mutations mediated primary resistance to BRAF inhibition in this patient. These mutations were present in all five tumours and in a tumour sample taken before BRAF inhibitor treatment was administered. Inhibition of both pathways was required to block tumour cell growth, suggesting that combined targeting of these pathways could have been a valid therapeutic approach for this patient.
doi:10.1093/annonc/mdu049
PMCID: PMC3999800  PMID: 24504448
BRAF; melanoma; mechanisms of resistance; intra-tumour heterogeneity; tumour evolution
8.  Targeted therapeutics in melanoma 
British Journal of Cancer  2012;107(9):1663.
doi:10.1038/bjc.2012.454
PMCID: PMC3493784
9.  Melanoma epidemiology, biology and prognosis 
EJC Supplements  2013;11(2):81-91.
doi:10.1016/j.ejcsup.2013.07.012
PMCID: PMC4041476
10.  A phase I study of the safety and tolerability of olaparib (AZD2281, KU0059436) and dacarbazine in patients with advanced solid tumours 
British Journal of Cancer  2011;104(5):750-755.
Background:
Poly adenosine diphosphate (ADP)-ribose polymerase (PARP) is essential in cellular processing of DNA damage via the base excision repair pathway (BER). The PARP inhibition can be directly cytotoxic to tumour cells and augments the anti-tumour effects of DNA-damaging agents. This study evaluated the optimally tolerated dose of olaparib (4-(3--4-fluorophenyl) methyl-1(2H)-one; AZD2281, KU0059436), a potent PARP inhibitor, with dacarbazine and assessed safety, toxicity, clinical pharmacokinetics and efficacy of combination treatment.
Patients and methods:
Patients with advanced cancer received olaparib (20–200 mg PO) on days 1–7 with dacarbazine (600–800 mg m−2 IV) on day 1 (cycle 2, day 2) of a 21-day cycle. An expansion cohort of chemonaive melanoma patients was treated at an optimally tolerated dose. The BER enzyme, methylpurine-DNA glycosylase and its substrate 7-methylguanine were quantified in peripheral blood mononuclear cells.
Results:
The optimal combination to proceed to phase II was defined as 100 mg bd olaparib with 600 mg m−2 dacarbazine. Dose-limiting toxicities were neutropaenia and thrombocytopaenia. There were two partial responses, both in patients with melanoma.
Conclusion:
This study defined a tolerable dose of olaparib in combination with dacarbazine, but there were no responses in chemonaive melanoma patients, demonstrating no clinical advantage over single-agent dacarbazine at these doses.
doi:10.1038/bjc.2011.8
PMCID: PMC3048218  PMID: 21326243
chemotherapy; dacarbazine; melanoma; PARP; resistance
11.  A prospective study of chemotherapy-induced febrile neutropenia in the South West London Cancer Network. Interpretation of study results in light of NCAG/NCEPOD findings 
British Journal of Cancer  2010;104(3):407-412.
Background:
Chemotherapy-induced febrile neutropenia is a medical emergency complicating the treatment of many cancer patients. It is associated with considerable morbidity and mortality, as well as impacting on healthcare resources.
Methods:
A prospective study of all cases of chemotherapy-induced febrile neutropenia in the South West London Cancer Network was conducted over a 4-month period. Factors including demographics, treatment history, management of febrile neutropenia and outcome were recorded.
Results and conclusi:
Our results reflect those of the recent National Chemotherapy Advisory Group (NCEPOD, 2008)/National Confidential Enquiry into Patient Outcomes and Death reports (NCAG, 2009) and highlight the need for network-wide clinical care pathways to improve outcomes in this area.
doi:10.1038/sj.bjc.6606059
PMCID: PMC3049562  PMID: 21179036
neutropenic sepsis; chemotherapy; infection; febrile neutropenia
12.  Challenges and opportunities for converting renal cell carcinoma into a chronic disease with targeted therapies 
British Journal of Cancer  2011;104(3):399-406.
Optimum efficacy is the primary goal for any cancer therapy, and entails controlling tumour growth and prolonging survival as far as possible. The prognosis for patients with metastatic renal cell carcinoma (mRCC) has greatly improved with the introduction of targeted therapies. This review examines the development and efficacy of targeted agents for the management of mRCC, the challenges offered by their rapid emergence, and discusses how mRCC treatment may evolve in the future. Improvements in progression-free survival and overall survival rates, observed with targeted agents, indicate that it may now be possible to change mRCC from a rapidly fatal and largely untreatable condition into a chronic disease. The major challenges to further advances in targeted therapy for mRCC include overcoming drug resistance, identifying the most effective sequence or combination of targeted agents, optimising clinical trial design and managing the cost of treatment.
doi:10.1038/sj.bjc.6606084
PMCID: PMC3049574  PMID: 21285971
chronic disease; combinatorial therapy; renal cell carcinoma; sequential therapy; sunitinib malate; targeted agents
13.  A phase I/II trial of sorafenib and infliximab in advanced renal cell carcinoma 
British Journal of Cancer  2010;103(8):1149-1153.
There is clinical evidence to suggest that tumour necrosis factor-α (TNF-α) may be a therapeutic target in renal cell carcinoma (RCC). Multi-targeted kinase inhibitors, such as sorafenib and sunitinib, have become standard of care in advanced RCC. The anti-TNF-α monoclonal antibody infliximab and sorafenib have differing cellular mechanisms of action. We conducted a phase I/II trial to determine the safety and efficacy of infliximab in combination with sorafenib in patients with advanced RCC.
Eligible patients were systemic treatment-naive or had received previous cytokine therapy only. Sorafenib and infliximab were administered according to standard schedules. The study had two phases: in phase I, the safety and toxicity of the combination of full-dose sorafenib and two dose levels of infliximab were evaluated in three and three patients, respectively, and in phase II, further safety, toxicity and efficacy data were collected in an expanded patient population.
Acceptable safety was reported for the first three patients (infliximab 5 mg kg−1) in phase 1. Sorafenib 400 mg twice daily and infliximab 10 mg kg−1 were administered to a total of 13 patients (three in phase 1 and 10 in phase 2). Adverse events included grade 3 hand–foot syndrome (31%), rash (25%), fatigue (19%) and infection (19%). Although manageable, toxicity resulted in 75% of the patients requiring at least one dose reduction and 81% requiring at least one dose delay of sorafenib. Four patients were progression-free at 6 months (PFS6 31%); median PFS and overall survival were 6 and 14 months, respectively.
Sorafenib and infliximab can be administered in combination, but a significant increase in the numbers of adverse events requiring dose adjustments of sorafenib was observed. There was no evidence of increased efficacy compared with sorafenib alone in advanced RCC. The combination of sorafenib and infliximab does not warrant further evaluation in patients with advanced RCC.
doi:10.1038/sj.bjc.6605889
PMCID: PMC2967062  PMID: 20842130
renal cell carcinoma; sorafenib; infliximab
14.  Successful removal of a giant intrathoracic lipoma: a case report and review of the literature 
Cases Journal  2008;1:87.
We report a case of a 44-year old female who presented to her physician complaining of mild dyspnea. A follow-up chest X-ray and chest computed tomography scan revealed a giant bilateral intrathoracic mass, filling the right thoracic cavity and extending across the anterior mediastinum into the left chest cavity. This large mass caused a marked shift in the midline structures, displacing the heart to the left hemi-thorax. The patient underwent surgical removal of the thoracic and breast mass, with histologic examination confirming the diagnosis of a giant intrathoracic lipoma, weighing 4,320 grams and measured 34 × 28 × 11 cm. It is the largest intrathoracic lipoma documented in the modern literature.
doi:10.1186/1757-1626-1-87
PMCID: PMC2526070  PMID: 18700019
15.  A Phase I/II study of lomustine and temozolomide in patients with cerebral metastases from malignant melanoma 
British Journal of Cancer  2006;96(1):44-48.
Temozolomide is an alkylating agent with activity in the treatment of melanoma metastatic to the brain. Lomustine is a nitrosurea that crosses the blood brain barrier and there is evidence to suggest that temozolomide may reverse resistance to lomustine. A multicentre phase I/II study was conducted to assess the maximum-tolerated dose (MTD), safety and efficacy of the combination of temozolomide and lomustine in melanoma metastatic to the brain. Increasing doses of temozolomide and lomustine were administered in phase I of the study to determine the MTD. Patients were treated at the MTD in phase II of the study to six cycles, disease progression or unacceptable toxicity. Twenty-six patients were enrolled in the study. In phase I of the study, the MTD was defined as temozolomide 150 mg m−2 days 1–5 every 28 days and lomustine 60 mg m–2 on day 5 every 56 days. Dose-limiting neutropaenia and thrombocytopaenia were observed at higher doses. Twenty patients were treated at this dose in phase II of the study. No responses to therapy were observed. Median survival from starting chemotherapy was 2 months. The combination of temozolomide and lomustine in patients with brain metastases from melanoma does not demonstrate activity. The further evaluation of this combination therefore is not warranted.
doi:10.1038/sj.bjc.6603503
PMCID: PMC2360201  PMID: 17146474
cerebral metastases; melanoma; chemotherapy; lomustine; temozolomide
16.  Low dose prednisolone for treatment of RA 
Annals of the Rheumatic Diseases  2004;63(11):1533-1534.
PMCID: PMC1754805  PMID: 15479919
17.  High prevalence of low plasma thiamine concentration in diabetes linked to a marker of vascular disease 
Diabetologia  2007;50(10):2164-2170.
Aims/hypothesis
To assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction.
Methods
Diabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined.
Results
Plasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5–69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5–19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0–9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = −0.531, p < 0.001) and fractional excretion of thiamine (r = −0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = −0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = −0.246, p < 0.05, and −0.311, p < 0.01, respectively).
Conclusions/interpretation
Low plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.
doi:10.1007/s00125-007-0771-4
PMCID: PMC1998885  PMID: 17676306
Adhesion molecules; Microalbuminuria; Thiamine; Type 1 diabetes; Type 2 diabetes
18.  Lack of radiological and clinical benefit over two years of low dose prednisolone for rheumatoid arthritis: results of a randomised controlled trial 
Annals of the Rheumatic Diseases  2004;63(7):797-803.
Background: Evidence for disease modifying activity of low dose corticosteroid treatment in rheumatoid arthritis is contradictory. Studies showing radiological benefit suggest that continued treatment is required to sustain the effect.
Objective: To evaluate the effect of low dose oral prednisolone in early rheumatoid arthritis on disease activity over two years.
Design: Double blind placebo controlled trial.
Methods: Patients with rheumatoid arthritis, duration <3 years (n = 167), were started on a disease modifying antirheumatic drug (DMARD; sulphasalazine) and allocated by stratified randomisation to prednisolone 7 mg/day or placebo. Primary outcome measure was radiological damage, assessed by the modified Sharp method. Clinical benefit was a secondary outcome. A proactive approach to identifying and treating corticosteroid adverse events was adopted. Patients who discontinued sulphasalazine were offered an alternative DMARD.
Results: 90 of 257 patients eligible for the study refused to participate (more women than men). Of those enrolled, 84% were seropositive for rheumatoid factor, median age 56 years, median disease duration 12 months, female to male ratio 1.8:1. Prednisolone was given to 84 patients; of these 73% continued prednisolone and 70% sulphasalazine at 2 years. Of the 83 patients on placebo, 80% continued placebo and 64% sulphasalazine at 2 years. There were no significant differences in radiological score or clinical and laboratory measures at 0 and 2 years.
Conclusions: Low dose prednisolone conferred no radiological or clinical benefit on patients maintained on a DMARD over two years. Low dose corticosteroids have no role in the routine management of rheumatoid arthritis treated with conventional disease modifying drugs.
doi:10.1136/ard.2003.014050
PMCID: PMC1755058  PMID: 15194574
19.  Ethanol-induced retention of nascent proteins in rat hepatocytes is accompanied by altered distribution of the small GTP-binding protein rab2. 
Journal of Clinical Investigation  1996;98(9):2146-2157.
Chronic ethanol consumption induces hepatocellular retention of nascent proteins leading to hepatomegaly. While the molecular mechanisms behind this impairment are undefined, it has been predicted that protein retention results from a disruption of vesicle-mediated secretory processes. Small GTP-binding proteins (rab proteins) have recently been implicated in the regulation of vesicular trafficking in eukaryotic cells. Our objectives were to identify intracellular sites of ethanol-induced protein retention and to determine whether the distribution of secretory rab proteins was altered by ethanol. Transport of hepatic proteins along the secretory pathway in livers from control and ethanol-fed rats was analyzed using subcellular fractionation and immunoprecipitation in the context of in vivo pulse-chase experiments. We show that pre-Golgi and Golgi compartments, as well as secretory vesicles, are sites of ethanol-induced retention of nascent soluble and transmembrane secretory proteins. These results are supported by immunofluorescence localization of hepatic proteins on liver sections. Further, immunoblot analyses of hepatic subcellular fractions from ethanol-damaged livers indicate a dramatic reduction in the association of rab2 with a Golgi compartment as compared with controls. In contrast, rab6 and alpha-mannosidase II, Golgi marker proteins, appear unchanged. These studies provide a detailed analysis of the intracellular site of ethanol-induced protein retention in the hepatocyte and lend novel insight into a potential mechanism behind this impairment. The effects of ethanol exposure on rab proteins and Golgi function are discussed.
PMCID: PMC507660  PMID: 8903335
20.  Breathing, sleep state, and rectal temperature oscillations. 
Archives of Disease in Childhood  1996;74(5):427-431.
Overheating may cause terminal apnoea and cot death. Rectal temperature and breathing patterns were examined in normal infants at home during the first 6 months of life. Twenty one infants had continuous overnight rectal temperature and breathing recordings for 429 nights (mean 20.4 nights, range 7-30) spaced over the first six months of life. Periods when breathing was 'regular' were directly marked on single night records. Sleep state was determined from respiratory variables. 'Regular' breathing was a reliable marker of 'quiet' sleep (specificity 93%). The duration of 'quiet' sleep increased from 6 to 22 minutes from two weeks to three months of age and then remained static, as did the proportion of sleep spent in the quiet phase (9% to 34%). Rectal temperature fell during 66% of quiet sleep and usually rose during rapid eye movement (REM) sleep. The drop in rectal temperature was maximal at the start of quiet sleep, whereas the maximum rise during REM sleep was reached after 10 to 15 minutes. Oscillations in rectal temperature are associated with changes in sleep and breathing state. The maturation of rectal temperature patterns during the first six months of life are closely related to a maturation of sleep state and breathing patterns.
PMCID: PMC1511530  PMID: 8669959
21.  Peripheral benzodiazepine receptors in platelets of epileptic patients. 
Tolerance to the anticonvulsant effect of benzodiazepines is likely to involve changes at the central benzodiazepine-GABA receptor complex. Peripheral benzodiazepine receptors (pBZRs), which can be measured in platelets, may also be involved. Using a binding assay with [3H]-PK 11195 as radioligand, pBZRs were assayed in platelets of patients taking a variety of antiepileptic drugs (AEDs). Comparisons were made with untreated patients. pBZR receptor density (mean +/- s.e. mean) was increased vs controls (8083 +/- 557 fmol mg-1 protein) in the platelets of patients taking a polypharmacy regime including the benzodiazepine clobazam (12661 +/- 1011 fmol mg-1 protein, P < 0.005) and also in those receiving sodium valproate as monotherapy (15003 +/- 1756 fmol mg-1 protein, P < 0.01). The significance of these findings is unclear, but the use of a specific pBZR antagonist may be a promising avenue for investigating the mechanism of BZ tolerance and its prevention.
PMCID: PMC1364558  PMID: 8396957
22.  Dietary omega-3 polyunsaturated fatty acids inhibit phosphoinositide formation and chemotaxis in neutrophils. 
Journal of Clinical Investigation  1993;91(2):651-660.
Earlier studies demonstrated that dietary omega-3 polyunsaturated fatty acid (PUFA) supplementation attenuates the chemotactic response of neutrophils and the generation of leukotriene (LT) B4 by neutrophils stimulated with calcium ionophore; however, the mechanisms and relationship of these effects were not examined. Neutrophils and monocytes from eight healthy individuals were examined before and after 3 and 10 wk of dietary supplementation with 20 g SuperEPA daily, which provides 9.4 g eicosapentaenoic acid (EPA) and 5 g docosahexaenoic acid. The maximal neutrophil chemotactic response to LTB4, assessed in Boyden microchambers, decreased by 69% after 3 wk and by 93% after 10 wk from prediet values. The formation of [3H]inositol tris-phosphate (IP3) by [3H]inositol-labeled neutrophils stimulated by LTB4 decreased by 71% after 3 wk (0.033 +/- 0.013% [3H] release, mean +/- SEM) and by 90% after 10 wk (0.011 +/- 0.011%) from predict values (0.114 +/- 0.030%) as quantitated by beta-scintillation counting after resolution on HPLC. LTB4-stimulated neutrophil chemotaxis and IP3 formation correlated significantly (P < 0.0001); each response correlated closely and negatively with the EPA content of the neutrophil phosphatidylinositol (PI) pool (P = 0.0003 and P = 0.0005, respectively). Neither the affinities and densities of the high and low affinity LTB4 receptors on neutrophils nor LTB4-mediated diglyceride formation changed appreciably during the study. Similar results were observed in neutrophils activated with platelet-activating factor (PAF). The summed formation of LTB4 plus LTB5 was selectively inhibited in calcium ionophore-stimulated neutrophils and was also inhibited in zymosan-stimulated neutrophils. The inhibition of the summed formation of LTB4 plus LTB5 in calcium ionophore-stimulated neutrophils and in zymosan-stimulated neutrophils did not correlate significantly with the EPA content of the PI pool. The data indicate that dietary omega-3 PUFA supplementation inhibits the autoamplification of the neutrophil inflammatory response by decreasing LTB4 formation through the inactivation of the LTA epoxide hydrolase and independently by inhibiting LTB4- (and PAF) stimulated chemotaxis by attenuating the formation of IP3 by the PI-selective phospholipase C. This is the initial demonstration that dietary omega-3 PUFA supplementation can suppress signal transduction at the level of the PI-specific phospholipase C in humans.
Images
PMCID: PMC288002  PMID: 8381824
23.  Rapid tolerance to acute psychomotor impairment with carbamazepine in epileptic patients. 
Thirteen patients with newly diagnosed epilepsy performed a battery of psychomotor function tests before and during the first 12 weeks of carbamazepine (CBZ) therapy. Movement time (P less than 0.025), total choice reaction time (P less than 0.025), finger tapping rate (P less than 0.005) and number cancellation (P less than 0.05) were all significantly impaired after 1 week's treatment, but had returned to baseline by 4 weeks. Mean (+/- s.d.) serum CBZ concentrations and those of its active metabolite CBZ 10,11 epoxide (CBZ-E) were comparable at 1 (CBZ: 8.5 +/- 2.1 mg l-1, CBZ-E: 1.1 +/- 0.68 mg l-1) and 4 weeks (CBZ: 8.1 +/- 4.4 mg l-1, CBZ-E: 0.93 +/- 0.27 mg l-1). These results suggest the rapid development of tolerance to the acute deleterious psychomotor effects of CBZ.
PMCID: PMC1381208  PMID: 1540481
24.  Lack of enzyme induction with oxcarbazepine (600 mg daily) in healthy subjects. 
1. Oxcarbazepine (OXC), the 10-keto analogue of carbamazepine (CBZ), has similar anticonvulsant efficacy and possibly improved patient tolerability. Unlike CBZ, it is metabolised by reduction and may not induce hepatic monooxygenase enzymes. 2. Serum concentrations of OXC and its active metabolite 10-OH-carbazepine (10-OH-CZ) were followed after a single 300 mg dose and during and after 300 mg OXC twice daily for 29 doses in eight healthy male volunteers. 3. Antipyrine metabolism, urinary 6-beta-hydroxycortisol excretion, sex hormone binding globulin (SHBG) levels and circulating androgens were measured as indices of hepatic enzyme induction before, during and after treatment with OXC. 4. Elimination half-lives (mean +/- s.e. mean) of 10-OH-CZ were unaltered by 2 weeks' therapy with OXC (before 11.3 +/- 1.1 h; after 13.9 +/- 3 h). Trough plasma concentrations of 10-OH-CZ at steady-state (31 +/- 2.2 mumol l-1) were higher than predicted (16.5 +/- 4 mumol l-1). 5. Antipyrine metabolism, urinary 6-beta-hydroxycortisol excretion, SHBG levels and circulating androgens were unaltered by treatment with OXC. 6. OXC (600 mg daily) does not induce hepatic monooxygenase enzymes and so is likely to have more predictable dose-concentration relationships and to produce fewer physiological and pharmacological interactions than CBZ.
PMCID: PMC1368413  PMID: 2015172

Results 1-25 (36)