Zebrafish Oatp-mediated transport of microcystin congeners

Microcystins (MC), representing >100 congeners being produced by cyanobacteria, are a hazard for aquatic species. As MC congeners vary in their toxicity, the congener composition of a bloom primarily dictates the severity of adverse effects and appears primarily to be governed by toxicokinetics, i.e., whether transport of MCs occurs via organic anion-transporting polypeptides (Oatps). Differences in observed MC toxicity in various fish species suggest differential expression of Oatp subtypes leading to varying tissue distribution of the very same MC congener within different species. The objectives of this study were the functional characterization and analysis of the tissue distribution of Oatp subtypes in zebrafish (Danio rerio) as a surrogate model for cyprinid fish. Zebrafish Oatps (zfOatps) were cloned, and the organ distribution was determined at the mRNA level. zfOatps were transiently expressed in HEK293 cells for functional characterization using the Oatp substrates estrone-3-sulfate, taurocholate and methotrexate and specific MC congeners (MC-LR, MC-RR, MC-LF and MC-LW). Novel zfOatp isoforms were isolated. Among these isoforms, the organ-specific expression of zfOatp1d1 and of members of the zfOatp1f subfamily was identified. At the functional level, zfOatp1d1, zfOatp1f2, zfOatp1f3 and zfOatp1f4 transported at least one of the Oatp substrates, and zfOatp1d1, zfOatp1f2 and zfOatp1f4 were shown to transport MC congeners. MC-LF and MC-LW were generally transported faster than MC-LR and MC-RR. The subtype-specific expression of zfOatp1d1 and of members of the zfOatp1f subfamily as well as differences in the transport of MC congeners could explain the MC congener-dependent differences in toxicity in cyprinids.

Principles of Pharmacology and Toxicology Also Govern Effects of Chemicals on the Endocrine System

The present debate on chemicals with Hormonal activity, often termed 'endocrine disruptors', is highly controversial and includes challenges of the present paradigms used in toxicology and in hazard identification and risk characterization. In our opinion, chemicals with hormonal activity can be subjected to the well-evaluated health risk characterization approach used for many years including adverse outcome pathways. Many of the points arguing for a specific approach for risk characterization of chemicals with hormonal activity are based on highly speculative conclusions. These conclusions are not well supported when evaluating the available information.

Bevacizumab continuation versus no continuation after first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer: a randomized phase III non-inferiority trial (SAKK 41/06)

BACKGROUND

Chemotherapy plus bevacizumab is a standard option for first-line treatment in metastatic colorectal cancer (mCRC) patients. We assessed whether no continuation is non-inferior to continuation of bevacizumab after completing first-line chemotherapy.

PATIENTS AND METHODS

In an open-label, phase III multicentre trial, patients with mCRC without disease progression after 4-6 months of standard first-line chemotherapy plus bevacizumab were randomly assigned to continuing bevacizumab at a standard dose or no treatment. CT scans were done every 6 weeks until disease progression. The primary end point was time to progression (TTP). A non-inferiority limit for hazard ratio (HR) of 0.727 was chosen to detect a difference in TTP of 6 weeks or less, with a one-sided significance level of 10% and a statistical power of 85%.

RESULTS

The intention-to-treat population comprised 262 patients: median follow-up was 36.7 months. The median TTP was 4.1 [95% confidence interval (CI) 3.1-5.4] months for bevacizumab continuation versus 2.9 (95% CI 2.8-3.8) months for no continuation; HR 0.74 (95% CI 0.58-0.96). Non-inferiority could not be demonstrated. The median overall survival was 25.4 months for bevacizumab continuation versus 23.8 months (HR 0.83; 95% CI 0.63-1.1; P = 0.2) for no continuation. Severe adverse events were uncommon in the bevacizumab continuation arm. Costs for bevacizumab continuation were estimated to be ∼30,000 USD per patient.

CONCLUSIONS

Non-inferiority could not be demonstrated for treatment holidays versus continuing bevacizumab monotheray, after 4-6 months of standard first-line chemotherapy plus bevacizumab. Based on no impact on overall survival and increased treatment costs, bevacizumab as a single agent is of no meaningful therapeutic value. More efficient treatment approaches are needed to maintain control of stabilized disease following induction therapy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, number NCT00544700.

A roadmap for hazard monitoring and risk assessment of marine biotoxins on the basis of chemical and biological test systems

Aquatic food accounts for over 40% of global animal food products, and the potential contamination with toxins of algal origin--marine biotoxins--poses a health threat for consumers. The gold standards to assess toxins in aquatic food have traditionally been in vivo methods, i.e., the mouse as well as the rat bioassay. Besides ethical concerns, there is also a need for more reliable test methods because of low inter-species comparability, high intra-species variability, the high number of false positive and negative results as well as questionable extrapolation of quantitative risk to humans. For this reason, a transatlantic group of experts in the field of marine biotoxins was convened from academia and regulatory safety authorities to discuss future approaches to marine biotoxin testing. In this report they provide a background on the toxin classes, on their chemical characterization, the epidemiology, on risk assessment and management, as well as on their assumed mode of action. Most importantly, physiological functional assays such as in vitro bioassays and also analytical techniques, e.g., liquid chromatography coupled mass spectrometry (LC-MS), as substitutes for the rodent bioassay are reviewed. This forms the basis for recommendations on methodologies for hazard monitoring and risk assessment, establishment of causality of intoxications in human cases, a roadmap for research and development of human-relevant functional assays, as well as new approaches for a consumer directed safety concept.

Prevention of palmar-plantar erythrodysesthesia with an antiperspirant in breast cancer patients treated with pegylated liposomal doxorubicin (SAKK 92/08)

BACKGROUND

Elevated concentrations of doxorubicin are found in eccrine sweat glands of the palms and soles. We therefore evaluated an antiperspirant as preventive treatment for palmar-plantar erythrodysesthesia (hand-foot syndrome) in patients with metastatic breast cancer treated with pegylated liposomal doxorubicin.

PATIENTS AND METHODS

An antiperspirant containing aluminum chlorohydrate or placebo cream was applied to the left or right hand and foot in a double-blinded manner (intra-patient randomization). The primary endpoint was the rate of grade 2 or 3 palmar-plantar erythrodysesthesia. A secondary endpoint was the patient-reported symptom burden (tingling, numbness, pain, or skin problems). Using McNemar's matched pairs design, 53 patients were needed to detect a 20% difference between the treatment and placebo sides with a significance level of 5% and power of 90%.

RESULTS

Grade 2 or 3 PPE occurred in 30 (58%) of 52 evaluable patients; in six patients adverse effects occurred on the placebo side but not on the treatment side, whereas one patient developed palmar-plantar erythrodysesthesia on the treatment side only (P = 0.07). Four patients developed grade 2 or 3 palmar-plantar erythrodysesthesia on their foot on the placebo side but not on the treatment side (P = 0.05). In the cohort with grade 2 or 3 palmar-plantar erythrodysesthesia there was a trend towards fewer dermatologic symptomatologies with the active treatment (P = 0.05), and no difference for other adverse events.

CONCLUSION

Using topical aluminum chlorohydrate as an antiperspirant appears to reduce the incidence of grade 2 or 3 palmar-plantar erythrodysesthesia following pegylated liposomal doxorubicin chemotherapy for metastatic breast cancer.

Clinical benefit response in pancreatic cancer trials revisited

OBJECTIVES

Clinical benefit response (CBR), based on changes in pain, Karnofsky performance status, and weight, is an established palliative endpoint in trials for advanced gastrointestinal cancer. We investigated whether CBR is associated with survival, and whether CBR reflects a wide-enough range of domains to adequately capture patients' perception.

METHODS

CBR was prospectively evaluated in an international phase III chemotherapy trial in patients with advanced pancreatic cancer (n = 311) in parallel with patient-reported outcomes (PROs).

RESULTS

The median time to treatment failure was 3.4 months (range: 0-6). The majority of the CBRs (n = 39) were noted in patients who received chemotherapy for at least 5 months. Patients with CBR (n = 62) had longer survival than non-responders (n = 182) (hazard ratio = 0.69; 95% confidence interval: 0.51-0.94; p = 0.013). CBR was predicted with a sensitivity and specificity of 77-80% by various combinations of 3 mainly physical PROs. A comparison between the duration of CBR (n = 62, median = 8 months, range = 4-31) and clinically meaningful improvements in the PROs (n = 100-116; medians = 9-11 months, range = 4-24) showed similar intervals.

CONCLUSION

CBR is associated with survival and mainly reflects physical domains. Within phase III chemotherapy trials for advanced gastrointestinal cancer, CBR can be replaced by a PRO evaluation, without losing substantial information but gaining complementary information.

Cardioprotective and anti-hypertensive effects of Prosopis glandulosa in rat models of pre-diabetes

Aim

Obesity and type 2 diabetes present with two debilitating complications, namely, hypertension and heart disease. The dried and ground pods of Prosopis glandulosa (commonly known as the Honey mesquite tree) which is part of the Fabaceae (or legume) family are currently marketed in South Africa as a food supplement with blood glucose-stabilising and anti-hypertensive properties. We previously determined its hypoglycaemic effects, and in the current study we determined the efficacy of P glandulosa as anti-hypertensive agent and its myocardial protective ability.

Methods

Male Wistar rats were rendered either pre-diabetic (diet-induced obesity: DIO) or hypertensive (high-fat diet: HFD). DIO animals were treated with P glandulosa (100 mg/kg/day for the last eight weeks of a 16-week period) and compared to age-matched controls. Hearts were perfused ex vivo to determine infarct size. Biometric parameters were determined at the time of sacrifice. Cardiac-specific insulin receptor knock-out (CIRKO) mice were similarly treated with P glandulosa and infarct size was determined. HFD animals were treated with P glandulosa from the onset of the diet or from weeks 12–16, using captopril (50 mg/kg/day) as the positive control. Blood pressure was monitored weekly.

Results

DIO rats and CIRKO mice: P glandulosa ingestion significantly reduced infarct size after ischaemia–reperfusion. Proteins of the PI-3-kinase/PKB/Akt survival pathway were affected in a manner supporting cardioprotection. HFD model: P glandulosa treatment both prevented and corrected the development of hypertension, which was also reflected in alleviation of water retention.

Conclusion

P glandulosa was cardioprotective and infarct sparing as well as anti-hypertensive without affecting the body weight or the intra-peritoneal fat depots of the animals. Changes in the PI-3-kinase/PKB/Akt pathway may be causal to protection. Results indicated water retention, possibly coupled to vasoconstriction in the HFD animals, while ingestion of P glandulosa alleviated both. We concluded that treatment of pre-diabetes, type 2 diabetes or hypertension with P glandulosa poses possible beneficial health effects.

Endocrine disruption: fact or urban legend?

Endocrine disruptors (EDs) are substances that cause adverse health effects via endocrine-mediated mechanisms in an intact organism or its progeny or (sub) populations. Purported EDCs in personal care products include 4-MBC (UV filter) or parabens that showed oestrogenic activity in screening tests, although regulatory toxicity studies showed no adverse effects on reproductive endpoints. Hormonal potency is the key issue of the safety of EDCs. Oestrogen-based drugs, e.g. the contraceptive pill or the synthetic oestrogen DES, possess potencies up to 7 orders of magnitude higher than those of PCP ingredients; yet, in utero exposure to these drugs did not adversely affect fertility or sexual organ development of offspring unless exposed to extreme doses. Additive effects of EDs are unlikely due to the multitude of mechanisms how substances may produce a hormone-like activity; even after uptake of different substances with a similar mode of action, the possibility of additive effects is reduced by different absorption, metabolism and kinetics. This is supported by a number of studies on mixtures of chemical EDCs. Overall, despite of 20 years of research a human health risk from exposure to low concentrations of exogenous chemical substances with weak hormone-like activities remains an unproven and unlikely hypothesis.

Bevacizumab continuation versus no continuation after first-line chemo-bevacizumab therapy in patients with metastatic colorectal cancer: A randomized phase III noninferiority trial (SAKK 41/06)

3503

Background: Chemotherapy plus bevacizumab is a standard option for first-line treatment in metastatic colorectal cancer patients. We assessed whether no continuation is non-inferior to continuation of bevacizumab after stop of first-line chemotherapy. Methods: In an open-label, phase 3 multicenter study conducted in Switzerland, patients with unresectable metastatic colorectal cancer having non-progressive disease after 4-6 months of standard first-line chemotherapy plus bevacizumab were randomly assigned in a 1:1 ratio to continuing bevacizumab (7.5 mg/kg every 3 weeks) or no treatment. CT scans were done every 6 weeks between randomization and disease progression. The primary endpoint was time to progression (TTP). A non-inferiority limit for hazard ratio (HR) of 0.727 was chosen to detect a difference in TTP of 6 weeks or less, with a one-sided significant level of 10% and a statistical power of 85%. Results: The per-protocol population comprised 262 patients. Median follow-up is 28.6 months (range, 0.6-54.9 months). Median TTP was 17.9 weeks (95% CI 13.3-23.4) for bevacizumab continuation and 12.6 weeks (95% CI 12.0-16.4) for no continuation; HR 0.72 (95% CI 0.56-0.92). Median progression free-survival and overall survival, both measured from start of first-line treatment, was 9.5 months and 24.9 months for bevacizumab continuation and 8.5 months (HR 0.73 (95% CI 0.57 - 0.94)) and 22.8 months (HR 0.87 (95% CI 0.64 – 1.18)) for no continuation. Median time from randomization to second-line treatment was 5.9 months for bevacizumab and 4.8 for no continuation. Grade 3-4 adverse events in the bevacizumab continuation arm were uncommon. Conclusions: Non-inferiority could not be demonstrated. The 95% confidence intervals for the TTP HR indicate superiority of bevacizumab continuation after stop of first-line chemotherapy. The median differences in TTP and in time between randomization and start of second-line treatment were of moderate magnitude being less than 6 weeks. The results of an accompanying cost analysis will be presented at the meeting. Clinical trial information: NCT00544700.

Adult fathead minnow, Pimephales promelas, partial life-cycle reproductive and gonadal histopathology study with bisphenol A

Bisphenol A (BPA) is an intermediate used to produce epoxy resins and polycarbonate plastics. Although BPA degrades rapidly in the environment with aquatic half-lives from 0.5 to 6 d, it can be found in aquatic systems because of widespread use. To evaluate potential effects from chronic exposure, fathead minnows were exposed for 164 d to nominal concentrations of 1, 16, 64, 160, and 640 µg/L BPA. Population-level endpoints of survival, growth, and reproduction were assessed with supplemental endpoints (e.g., vitellogenin, gonad histology), including gonad cell type assessment and quantification. No statistically significant changes in growth, gonad weight, gonadosomatic index, or reproduction variables (e.g., number of eggs and spawns, hatchability) were observed; however, there was a significant impact on male survival at 640 µg/L. Vitellogenin increased in both sexes at 64 µg/L or higher. Gonad cell type frequencies were significantly different from controls at 160 µg/L or higher in males with a slight decrease in spermatocytes compared with less mature cell types, and at 640 µg/L in females with a slight decrease in early vitellogenic cells compared with less mature cells. The decrease in spermatocytes did not correspond to a decrease in the most mature sex cell type (spermatozoa) and did not impair male fertility, as hatchability was not impacted. Overall, marginal shifts in gametogenic cell maturation were not associated with any statistically significant effects on population-relevant reproductive endpoints (growth, fecundity, and hatchability) at any concentration tested.

Total hip arthroplasty: leg length inequality impairs functional outcomes and patient satisfaction

BACKGROUND

Leg length inequality (LLI) was identified as a problem of total hip arthroplasty soon after its introduction. Leg lengthening is the most common form of LLI. Possible consequences are limping, neuronal dysfunction and aseptic component loosening. LLI can result in an increased strain both on the contralateral hip joint and on the abductor muscles. We assessed the influence of leg lengthening and shortening on walking capacity, hip pain, limping and patient satisfaction at 2-year follow-up.

METHODS

478 cases with postoperative lengthening and 275 with shortening were identified, and matched with three controls each. Rigorous adjustment for potential differences in baseline patient characteristics was performed by propensity-score matching of covariates. The arbitrarily defined desired outcomes were a walking capacity >60 minutes, no hip pain, no limping, and excellent patient satisfaction. Differences in not achieving the desired outcomes between the groups were expressed as odds ratios.

RESULTS

In the lengthened case group, the odds ratio for not being able to walk for an hour was 1.70 (95% CI 1.28-2.26) for cases compared to controls, and the odds ratio for having hip pain at follow-up was 1.13 (95% CI 0.78-1.64). The odds ratio for limping was 2.08 (95% CI 1.55-2.80). The odds ratio for not achieving excellent patient satisfaction was 1.67 (95% CI 1.23-2.28). In the shortening case group, the odds ratio for not being able to walk for an hour was 1.23 (95% CI 0.84-1.81), and the odds ratio for having hip pain at follow-up was 1.60 (95% CI 1.05-2.44). The odds ratio for limping for cases was 2.61 (95% CI 1.78-3.21). The odds ratio for not achieving excellent patient satisfaction was 2.15 (95% CI 1.44-3.21).

CONCLUSIONS

Walking capacity, limping and patient satisfaction were all significantly associated with leg lengthening, whereas pain alleviation was not. In contrast, hip pain, limping and patient satisfaction were all significantly associated with leg shortening, whereas walking capacity was not.

Dasatinib first-line treatment in gastrointestinal stromal tumors: A multicenter phase II trial of the SAKK (SAKK 56/07)

10033

Background: First line imatinib has improved the outcome of patients (pts) with gastrointestinal stromal tumor (GIST), but primary and secondary resistance remain a problem. Dasatinib is a second generation tyrosine kinase inhibitor (TKI) and inhibits the activity of bcr-abl, src-family kinases along with a number of other oncogenic kinases including kit. In vitro, dasatinib has shown activity against imatinib-resistant cell lines. Routinely, pts diagnosed with GIST and treated with TKIs are monitored by computed tomography (CT). 18F-fluorodeoxyglucose positron-emission-tomography (FDG-PET) measures tumor metabolic activity for early response assessment, which might be of particular use in the clinical trial setting. Methods: This two-stage phase II trial investigated dasatinib in pts with TKI-naïve GIST. Dasatinib starting dose was 2x70mg/day in pts with histologically proven, FDG-PET positive GIST. Response evaluation was done by serial CT and FDG-PET using EORTC PET response criteria (Young et al. 1999). Elective surgery was allowed after 6 months of trial treatment. Primary endpoint was response (CR+PR) by FDG-PET after one month of dasatinib. Results: 47 of planned 52 pts have been enrolled from December 2007 to November 2011, when the trial was terminated due to slow accrual. 43 pts were eligible. Median age was 61 years, 24 pts were male, 19 female and 41 had a performance status of 0 or 1. At a median follow-up of 11.9 months, 20 pts were still on treatment. Pts went off trial for elective surgery (n=6), progression (n=11), toxicity (n=3), and three patients died (one on-drug). 5% of pts experienced G4, and 38% of pts G3 toxicity, which were most often gastrointestinal or pulmonary. 28% had their dose reduced or interrupted. The primary endpoint, FDG-PET response rate (CR+PR) at 4 weeks was 67% (13 CR, 16 PR, 7 SD, 3 PD, 4 not evaluable). Median progression-free survival is 11.1 months and median overall survival not yet reached. Conclusions: Dasatinib shows promising efficacy in TKI-naïve pts with FDG-PET positive GIST. Mutational data will be presented at the meeting.

Ageing Challenges the Results of any Outcome Study: How to Address the Effects of Ageing on Activities of Daily Living

OBJECTIVES: Clinical study results might be substantially biased by the effects of ageing, resulting in considerable underestimation of treatment efficacy, especially when assessing activities of daily living (ADL) in elderly people. This study aimed to define age- and comorbidity-related normative values in ADL. METHODS: In cross-sectional sampling, 23 763 German-speaking Swiss individuals were contacted. Valid questionnaires from 16 191 (68%) eligible individuals ≥ 18 years of age were included in the study. Age-related ADL reference values were calculated using questionnaire data. RESULTS: The sample was representative of the German-speaking Swiss population as determined by 2003 census data. Age- and pain-related ADL reference values were plotted and confirmed that disability increased with increasing age. CONCLUSIONS: The use of ADL scales that provide age- and comorbidity-related reference values for outcome studies or studies focusing on the elderly is recommended in order to reduce the effect of bias.