Evaluating femoral graft placement using three-dimensional magnetic resonance imaging in the reconstruction of the anterior cruciate ligament via independent or transtibial drilling techniques: a retrospective cohort study

PURPOSE

Anterior cruciate ligament (ACL) reconstruction is a common surgical procedure, yet failure still largely occurs due to nonanatomically positioned grafts. The purpose of this study was to retrospectively evaluate patients with torn ACLs before and after reconstruction via 3D MRI and thereby assess the accuracy of graft position on the femoral condyle.

METHODS

Forty-one patients with unilateral ACL tears were recruited. Each patient underwent 3D MRI of both knees before and after surgery. The location of the reconstructed femoral footprint relative to the patient's native footprint was compared.

RESULTS

Native ACL anatomical location of the native ACL had a significant impact on graft position. Native ACLs that were previously more anterior yielded grafts that were more posterior (3.70 ± 1.22 mm, P = 0.00018), and native ACL that were previously more proximal yielded grafts that were more distal (3.25 ± 1.09 mm, P = 0.0042). Surgeons using an independent drilling method positioned 76.2% posteriorly relative to the native location, with a mean 0.1 ± 2.8 mm proximal (P = 0.8362) and 1.8 ± 3.0 mm posterior (P = 0.0165). Surgeons using a transtibial method positioned 75% proximal relative to the native location, with a mean 2.2 ± 3.0 mm proximal (P = 0.0042) and 0.2 ± 2.6 mm posterior (P = 0.8007). These two techniques showed a significant difference in magnitude in the distal-proximal axis (P = 0.0332).

CONCLUSION

The femoral footprint position differed between the native and reconstructed ACLs, suggesting that ACL reconstructions are not accurate. Rather, they are converging to a normative reference point that is neither anatomical nor isometric.

Clinical, Radiologic, and Functional Outcomes following Bone Grafting for Metacarpal Non-Unions: A Systematic Review

Objectives: Metacarpal non-unions are complex hand defects that can lead to severe hand impairment. Treatment may require the use of artificial or autologous bone grafts. This systematic review aims to describe the outcomes of bone grafting following metacarpal non-union in an attempt to establish an optimal therapeutic protocol for this complication. Methods: A systematic review was conducted in adherence with PRISMA guidelines. Data collection and analysis were performed in duplicate and confirmed by a third investigator. Our primary outcomes focused on radiological time to bone fusion and rates of non-union. Additionally, functional outcomes and complications were analyzed as means of central tendency. Results: Eighteen studies were included in the systematic review, accounting for a total of 47 patients. The average follow-up time was 12.4 months. Fourteen studies analyzed radiological outcomes, with atrophic non-union representing the most common type. The time to bone fusion, assessed radiologically, following bone graft was an average of 6.9 months (n = 14), with a 100% rate of union in 42 patients. Regarding patient-reported pain improvement, 76% of patients experienced pain relief. Moreover, all patients reported a complete subjective return to baseline hand function. Adverse events, limited to hematoma and seroma, were seen in three patients, representing a complication rate of 11.8% in the examined population. Conclusions: Metacarpal non-union can be treated successfully via vascularized and non-vascularized bone grafting. Based on the available evidence, bone grafts demonstrate favorable union rates, post-operative pain reduction, hand function recovery, earlier bone fusion times, and minimal complications in the context of metacarpal non-union management.

Liquid Chromatographic Determination of Lysine, Methionine, and Threonine in Pure Amino Acids (Feed Grade) and Premixes: Collaborative Study

A total of 17 laboratories (including one author's laboratory) participated in a collaborative study for determination of lysine, methionine, and threonine in trade products or concentrated amino acid premixes. Thirteen samples, 4 pure amino acids and 6 premixes, including 3 Youden matched pairs, were analyzed. The applied liquid chromatographic (LC) method using cation-exchange resin and post-column derivatization with ninhydrin or o-phthaldialdehyde was shown to be accurate and specific for the analytes. Titration procedures, normally used for the assay of pure amino acids, are unspecific and the accuracy of the results can be affected by impurities. Repeatability relative standard deviations, RSDr, ranged from 0.84 to 1.17% for pure amino acids and from 0.50 to 1.68% for premixes; reproducibility relative standard deviations RSDR, ranged from 1.52 to 2.31% for pure amino acids and from 1.48 to 2.59% for premixes. Recoveries were between 97.5 and 102.8% of the expected amino acid assays. The method has been adopted Official First Action status by AOAC INTERNATIONAL.

Burden of disease and costs of exposure to endocrine disrupting chemicals in the European Union: an updated analysis

A previous report documented that endocrine disrupting chemicals contribute substantially to certain forms of disease and disability. In the present analysis, our main objective was to update a range of health and economic costs that can be reasonably attributed to endocrine disrupting chemical exposures in the European Union, leveraging new burden and disease cost estimates of female reproductive conditions from accompanying report. Expert panels evaluated the epidemiologic evidence, using adapted criteria from the WHO Grading of Recommendations Assessment, Development and Evaluation Working Group, and evaluated laboratory and animal evidence of endocrine disruption using definitions recently promulgated by the Danish Environmental Protection Agency. The Delphi method was used to make decisions on the strength of the data. Expert panels consensus was achieved for probable (>20%) endocrine disrupting chemical causation for IQ loss and associated intellectual disability; autism; attention deficit hyperactivity disorder; endometriosis; fibroids; childhood obesity; adult obesity; adult diabetes; cryptorchidism; male infertility, and mortality associated with reduced testosterone. Accounting for probability of causation, and using the midpoint of each range for probability of causation, Monte Carlo simulations produced a median annual cost of €163 billion (1.28% of EU Gross Domestic Product) across 1000 simulations. We conclude that endocrine disrupting chemical exposures in the EU are likely to contribute substantially to disease and dysfunction across the life course with costs in the hundreds of billions of Euros per year. These estimates represent only those endocrine disrupting chemicals with the highest probability of causation; a broader analysis would have produced greater estimates of burden of disease and costs.

Programming of metabolic effects in C57BL/6JxFVB mice by in utero and lactational exposure to perfluorooctanoic acid

Perfluorooctanoic acid (PFOA) is known to cause developmental toxicity and is a suggested endocrine disrupting compound (EDC). Early life exposure to EDCs has been implicated in programming of the developing organism for chronic diseases later in life. Here we study perinatal metabolic programming by PFOA using an experimental design relevant for human exposure. C57BL/6JxFVB hybrid mice were exposed during gestation and lactation via maternal feed to seven low doses of PFOA at and below the NOAEL used for current risk assessment (3-3000 µg/kg body weight/day). After weaning, offspring were followed for 23-25 weeks without further exposure. Offspring showed a dose-dependent decrease in body weight from postnatal day 4 to adulthood. Growth under high fat diet in the last 4-6 weeks of follow-up was increased in male and decreased in female offspring. Both sexes showed increased liver weights, hepatic foci of cellular alterations and nuclear dysmorphology. In females, reductions in perigonadal and perirenal fat pad weights, serum triglycerides and cholesterol were also observed. Endocrine parameters, such as glucose tolerance, serum insulin and leptin, were not affected. In conclusion, our study with perinatal exposure to PFOA in mice produced metabolic effects in adult offspring. This is most likely due to disrupted programming of metabolic homeostasis, but the assayed endpoints did not provide a mechanistic explanation. The BMDL of the programming effects in our study is below the current point of departure used for calculation of the tolerable daily intake.

Bringing obesity to light: Rev-erbα, a central player in light-induced adipogenesis in the zebrafish?

BACKGROUND

Recent studies have led to an expansion of potential factors capable of stimulating obesity. Increasing evidence indicates that environmental factors, including disturbance of circadian rhythms, also contribute to its etiology.

OBJECTIVES

To determine the effects of altered circadian rhythms on adipogenesis and to better understand how circadian and adipogenic regulatory pathways are linked, zebrafish larvae were exposed to various light/dark cycles or hypercaloric feeding (HCF).

METHODS

Clock and adipogenic gene expression was quantitative real time PCR. Adipogenesis was characterized using coherent anti-Stokes Raman scattering microscopy (CARS) and whole-mount lipid composition was analyzed by gas chromatography. The clock protein Rev-erbα and the adipogenesis-regulating protein Pparγ were localized by immunohistochemistry.

RESULTS

Zebrafish larvae exposed to continuous light (LL) had a sevenfold higher prevalence of adipocytes compared with control fish under a 14 h light and 10 h dark cycle. It was also significantly higher compared with that in HCF larvae with control light/dark cycle, which showed a 5.5-fold increase compared with control animals. Although total fatty acid content was unaffected, adipocyte lipid composition was altered in LL zebrafish. In contrast, shifting the onset and duration of the light periods did not affect adipogenesis or total fatty acid content. Gene expression analysis revealed effects of LL and HCF on circadian cyclicity, with increased expression of the clock gene period2 and altered circadian rev-erbα expression in LL larvae. Immunostaining revealed for the first time that Rev-erbα and Pparγ colocalize in adipocytes, which together with the gene expression analysis suggests interplay between Rev-erbα and Ppar isoforms.

CONCLUSIONS

The amount of light, but not shifted light/dark cycles, affected adipogenesis and lipid composition, possibly due to increased period2 expression, which, in turn, enhances Rev-erbα-regulated gene expression. As the pparβδ promoter includes three Rev-erbα binding sites, we hypothesize that pparβδ may be a direct target that ultimately activates Pparγ.

Comparability of behavioural assays using zebrafish larvae to assess neurotoxicity

Testing of compounds for neurotoxicity has become increasingly important in recent years. It has been shown that neurological disorders like autism may be related to chemical exposures, which may play a crucial role in the progression of these diseases. Special attention has been be given to the substances causing developmental neurotoxicity as the developing nervous system is more vulnerable to impacts by chemicals than the adult nervous system. The zebrafish (Danio rerio) is a well-established model species in developmental biology and an emerging model in behavioural and neurological studies. Zebrafish larvae display numerous behavioural patterns highly similar to rodents and humans. Their physical characteristics make them well suited for automated high-throughput screening. In the last years, the number of behavioural studies conducted with zebrafish larvae has increased notably. The goal of this review is to provide an overview of behavioural assays commonly used to test substances for developmental neurotoxicity. Literature from 1995 to 2014 was reviewed and focussed on assays performed with zebrafish larvae younger than 7 days post fertilization (dpf). The behavioural tests were scrutinized, and parameters describing the different experimental setups were defined. In the next step, we investigated if differences in the experimental parameters alter the outcome of the test. In order to test the comparability of behavioural assays, we analysed several studies using ethanol, valproate and pentylenetetrazole as model substances. Based on our findings, we provide recommendations which could help improve future behavioural studies performed with zebrafish larvae.

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10-10,000 pg/kg body weight/day; PCB 153: 0.09-1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes.

Neurodevelopmental retardation, as assessed clinically and with magnetoencephalography and electroencephalography, associated with perinatal dioxin exposure

In 1980s Western Europe, human perinatal exposure to background levels of dioxins was rather high. We therefore evaluated the neurodevelopment of our cohort during the prepubertal period and in adolescence. At prepubertal age (7-12 years) 41 children were tested. Both neuromotor functioning and psychological testing were performed (Dutch version of the Wechsler Intelligence Scale for Children (WISC-R) and the Dutch version of the Child Behavior Checklist for ages 4-18 years (CBCL 4-18) and the Teacher Report Form (TRF)). Neurophysiological tests were performed using magnetoencephalography and electroencephalography. In adolescence (14-18 years) the behavior of 33 children was studied again (CBCL and TRF). And the levels of dioxins and dioxin-like PCBs (dl-PCBs) were measured in serum.

RESULTS

At prepubertal age no association was found between perinatal dioxin exposure and verbal, performal and total IQ or with the Touwen's test for neuromotor development. There were behavioral problems associated with both prenatal and postnatal dioxin exposure. In adolescence there were problems associated with the current dioxin levels and dioxin-like-PCBs. Neurophysiological tests revealed clear negative dysfunction. An increase in latency time after a motion stimulus (N2b) of 13 ms (= a delay of 10%) is associated with the higher prenatal dioxin exposure. A similar delay was measured in testing cognitive ability by analyzing the odd ball measurements, N200 and P300, together with an amplitude decrease of 12 %. The delay is indicative of a defective myelinisation and the decrease in amplitude of a loss of neurons.

CONCLUSION

We found effects on behavior in association with the perinatal dioxin exposure and in adolescence in association with the current dioxin levels. Neurophysiological testing is instrumental in the detection of effects of perinatal background levels of chemicals on brain development in normal, healthy children. The clinical, neurological and psychological tests commonly used are not sensitive enough to detect important effects.

Programming of metabolic effects in C57BL/6JxFVB mice by exposure to bisphenol A during gestation and lactation

The global rise in prevalence of obesity is not fully explained by genetics or life style factors. The developmental origins of health and disease paradigm suggests that environmental factors during early life could play a role. In this perspective, perinatal exposure to bisphenol A (BPA) has been indicated as a programming factor for obesity and related metabolic disorders later in life. Here we study early life programming by BPA using an experimental design that is relevant for human exposure. C57BL/6JxFVB hybrid mice were exposed during gestation and lactation via maternal feed to 8 non-toxic doses (0-3000 μg/kg body weight/day (μg/kg bw/d)) of BPA. After weaning, offspring were followed for 20 weeks without further exposure. Adult male offspring showed dose-dependent increases of body and liver weights, no effects on fat pad weights and a dose-dependent decrease in circulating glucagon. Female offspring showed a dose-dependent decrease in body weight, liver, muscle and fat pad weights, adipocyte size, serum lipids, serum leptin and adiponectin. Physical activity was decreased in exposed males and suggested to be increased in exposed females. Brown adipose tissue showed slightly increased lipid accumulation in males and lipid depletion in females, and ucp1 expression was dose-dependently increased in females. The effects in females were more reliable and robust than in males due to wide confidence intervals and potential confounding by litter size for male data. The lowest derived BMDL (lower bound of the (two-sided) 90%-confidence interval for the benchmark dose) of 233 μg/kg bw/d (for interscapular weight in females) was below the proposed BMDL of 3633 μg/kg bw/d as a basis for tolerable daily intake. Although these results suggest that BPA can program for an altered metabolic phenotype, the sexual dimorphism of effects and diversity of outcomes among studies similar in design as the present study do not mark BPA as a specific obesogen. The consistency within the complex of observed metabolic effects suggests that upstream key element(s) in energy homeostasis are modified. Sex-dependent factors contribute to the final phenotypic outcome.

Recombinational micro-evolution of functionally different metallothionein promoter alleles from Orchesella cincta

Background

Metallothionein (mt) transcription is elevated in heavy metal tolerant field populations of Orchesella cincta (Collembola). This suggests that natural selection acts on transcriptional regulation of mt in springtails at sites where cadmium (Cd) levels in soil reach toxic values This study investigates the nature and the evolutionary origin of polymorphisms in the metallothionein promoter (pmt) and their functional significance for mt expression.

Results

We sequenced approximately 1600 bp upstream the mt coding region by genome walking. Nine pmt alleles were discovered in NW-European populations. They differ in the number of some indels, consensus transcription factor binding sites and core promoter elements. Extensive recombination events between some of the alleles can be inferred from the alignment. A deviation from neutral expectations was detected in a cadmium tolerant population, pointing towards balancing selection on some promoter stretches. Luciferase constructs were made from the most abundant alleles, and responses to Cd, paraquat (oxidative stress inducer) and moulting hormone were studied in cell lines. By using paraquat we were able to dissect the effect of oxidative stress from the Cd specific effect, and extensive differences in mt induction levels between these two stressors were observed.

Conclusion

The pmt alleles evolved by a number of recombination events, and exhibited differential inducibilities by Cd, paraquat and molting hormone. In a tolerant population from a metal contaminated site, promoter allele frequencies differed significantly from a reference site and nucleotide polymorphisms in some promoter stretches deviated from neutral expectations, revealing a signature of balancing selection. Our results suggest that the structural differences in the Orchesella cincta metallothionein promoter alleles contribute to the metallothionein -over-expresser phenotype in cadmium tolerant populations.

In vitro biomonitoring in polar extracts of solid phase matrices reveals the presence of unknown compounds with estrogenic activity

Determination of estrogenic activity has so far mainly concentrated on the assessment of compounds in surface water and effluent. This study is one of the first to biomonitor (xeno-)estrogens in sediment, suspended particulate matter and aquatic organisms. The relatively polar acetone extracts from these solid phase matrices do not contain the well-known estrogenic compounds such as hormones, alkylphenols and phthalates. An in vitro 'estrogen receptor-mediated chemical activated luciferase gene expression' (ER-CALUX) assay was applied to samples from various locations in the Netherlands. Estrogenic activity measured in polar fractions of particulate matter and sediment extracts ranged from below detection limit to up to 4.5 pmol estradiol equivalents (EEQ)/g dry weight. Estrogenic activity in freshwater river sediments was up to five times higher compared to sediments from large lakes and coastal locations. Tissue extracts EEQs were determined in bream (Abramis brama), flounder (Platichthysflesus), freshwater mussels (Dreissena polymorpha) and marine mussels (Mytilus edulis). The highest biota EEQ levels were found in the freshwater zebra mussel (30 pmol EEQ/g lipid). One sample site showed greatly elevated EEQs in sediment and biota, which correlated with effects found in the wild populations of bream. The EEQ activity of the unknown compounds in the polar fraction mostly was much higher than the calculated EEQ levels based on known estrogens in the non-polar fraction (previously published data).

Detection of oestrogenic activity of steroids present during mammalian gestation using oestrogen receptor alpha- and oestrogen receptor beta-specific in vitro assays

Numerous steroid hormones are present in the foetus but their potential to activate oestrogen receptor (ER) alpha and/or beta is largely unknown. In this study, in vitro assays were developed to rapidly and specifically detect ERalpha or ERbeta activation by these steroid hormones. Our results showed that several oestrogen precursors and androgens are able to activate both ERalpha and ERbeta. Of special interest is that some of these precursors are able to activate ERalpha and ERbeta at concentrations that are present during human gestation. Moreover, some precursors (dehydroepiandrosterone (DHEA) and 17-hydroxylated pregnenolone sulphate) and androgens (5-androsten-3beta,16alpha,17beta-triol and testosterone) showed a more than 100-fold relative preference for ERbeta transactivation over ERalpha transactivation when compared with 17beta-oestradiol. Due to their relatively high levels, the precursor steroids DHEA and pregnenolone may be of particular importance in the regulation of ERbeta activity in vivo. To obtain information about the oestrogenic activity of the total pool of steroid hormones present during mammalian gestation, steroids were extracted from mouse embryos at different prenatal stages and assayed for oestrogenic activity in the established in vitro assays. Oestrogenic activity was detected in steroid extracts from all stages tested. This study has demonstrated that oestrogen receptor agonists are present in the murine embryo and that oestrogen precursors may contribute to the total pool of agonists during foetal life.

Health outcomes after prostatectomy or radiotherapy for prostate cancer: results from the Prostate Cancer Outcomes Study

BACKGROUND

Radical prostatectomy and external beam radiotherapy are the two major therapeutic options for treating clinically localized prostate cancer. Because survival is often favorable regardless of therapy, treatment decisions may depend on other therapy-specific health outcomes. In this study, we compared the effects of two treatments on urinary, bowel, and sexual functions and on general health-related quality-of-life outcomes over a 2-year period following initial treatment.

METHODS

A diverse cohort of patients aged 55-74 years who were newly diagnosed with clinically localized prostate cancer and received either radical prostatectomy (n = 1156) or external beam radiotherapy (n = 435) were included in this study. A propensity score was used to balance the two treatment groups because they differed in some baseline characteristics. This score was used in multivariable cross-sectional and longitudinal regression analyses comparing the treatment groups. All statistical tests were two-sided.

RESULTS

Almost 2 years after treatment, men receiving radical prostatectomy were more likely than men receiving radiotherapy to be incontinent (9.6% versus 3.5%; P:<.001) and to have higher rates of impotence (79.6% versus 61.5%; P:<.001), although large, statistically significant declines in sexual function were observed in both treatment groups. In contrast, men receiving radiotherapy reported greater declines in bowel function than did men receiving radical prostatectomy. All of these differences remained after adjustments for propensity score. The treatment groups were similar in terms of general health-related quality of life.

CONCLUSIONS

There are important differences in urinary, bowel, and sexual functions over 2 years after different treatments for clinically localized prostate cancer. In contrast to previous reports, these outcome differences reflect treatment delivered to a heterogeneous group of patients in diverse health care settings. These results provide comprehensive and representative information about long-term treatment complications to help guide and inform patients and clinicians about prostate cancer treatment decisions.

Validation study of retrospective recall of disease-targeted function: results from the prostate cancer outcomes study

OBJECTIVES

This was an ancillary methodological study within the Prostate Cancer Outcomes Study (PCOS) to assess the validity of 6-month retrospective recall of prediagnostic disease-targeted function among men diagnosed with prostate cancer.

METHODS

A convenience sample of 133 prostate cancer cases were administered a baseline questionnaire shortly after diagnosis that asked about prediagnostic urinary, sexual, and bowel function. They were surveyed again concerning the same items 6 months later and asked to recall their prediagnostic function. Reports of prediagnostic function obtained at baseline and 6 months are compared, as are measures of change derived from these reports. Percent agreement and weighted kappas are calculated to measure the extent of agreement.

RESULTS

Over 70% of the men reported prediagnostic functioning at the highest level on 12 of 17 survey items. For each of these items, recall at 6 months was identical to the baseline survey response for > or =69% of the men. The values of the weighted kappas for changes computed with baseline reports (prospective) and changes computed with 6-month recall (retrospective) ranged from 0.396 to 0.919 for the 17 individual items. Intraclass correlations for the retrospective versus prospective changes in the multi-item function scores were 0.828 for urinary, 0.618 for bowel, and 0.692 for sexual function.

CONCLUSIONS

At baseline, men recently diagnosed with prostate cancer report few disease-related problems before diagnosis, and a high percentage of men recall this accurately 6 months later. There is reasonably high agreement between baseline and 6-month estimates of prediagnostic function and between prospective and retrospective measures of change over 6 months.

Development of a stably transfected estrogen receptor-mediated luciferase reporter gene assay in the human T47D breast cancer cell line

Development of an estrogen receptor-mediated, chemical-activated luciferase reporter gene-expression (ER-CALUX) assay was attempted by stable transfection of luciferase reporter genes in a number of cell lines. Stable transfection of the chimeric Gal4 estrogen receptor and luciferase gene constructs in MCF-7 breast cancer and Hepa.1c1c7 mouse hepatoma cell lines, as well as transfection of a newly constructed luciferase reporter gene pEREtata-Luc in the ECC-1 human endometrial cell line, resulted in constitutive, non-estradiol-inducible clones. Stable transfection of pEREtata-Luc in the T47D breast cancer cell line, however, resulted in an extremely sensitive, highly responsive cell line. Following a 24-h exposure to estradiol (E2), stably transfected T47D.Luc cells demonstrated a detection limit of 0.5 pM, an EC50 of 6 pM, and a maximum induction of 100-fold relative to solvent controls. No clear reduction in responsiveness has been found over extended culture periods (50 passages). Anti-estrogens ICI 182,780, TCDD, and tamoxifen inhibited the estradiol-mediated luciferase induction. Genistein, nonylphenol, and o,p'DDT were the most potent (pseudo-)estrogens tested in this system (EC50 100, 260, and 660 nM, respectively). Determination of interactive effects of the (pseudo-)estrogens nonylphenol, o,p'DDT, chlordane, endosulfan, dieldrin, and methoxychlor revealed that, in combination with 3 pM E2, (pseudo-)estrogens were additive. Slightly more than additive effects (less than 2-fold) were found for combinations of dieldrin and endosulfan tested in the range of 3 to 6 microM. At these concentrations, the combination of endosulfan and chlordane demonstrated additive interaction. The ER-CALUX assay with T47D cells can provide a sensitive, responsive, and rapid in vitro system to detect and measure substances with potential (anti-)estrogenic activity.

Environmental health assessment of the benthic habitat adjacent to a pulp mill discharge. I. Acute and chronic toxicity of sediments to benthic macroinvertebrates

In this study, we assessed the acute and chronic toxicity of sediments contaminated by bleached kraft pulp mill effluent (BKME). Sediments were collected in August 1991 and 1992, and May 1993 from eight stations exposed directly to the effluent and from four reference sites.Acute toxicity was determined for five macroinvertebrates (Hyalella azteca, Daphnia magna, Chironomus riparius, Hexagenia spp., and Tubifex tubifex) using pore water, elutriate, and bulk sediment exposures. Chronic toxicity was assessed using C. tentans and H. azteca (growth and survival) and D. magna and T. tubifex (reproduction) in bulk sediment exposures. Mortality declined with decreasing proximity to the outfall; acute toxicity (>20% mortality after 48 h)was observed at the two stations closest to the outfall (300 and 400 m). At 300 m, pore water was consistently more toxic than elutriate or bulk sediment phases, resulting in 100% mortality for all invertebrates except T. tubifex (23%). Elutriate exposures were toxic to C. riparius (88%), D. magna (54%), and Hexagenia (47%), but not H. azteca. Bulk sediments were toxic to Hexagenia (100%) and D. magna(88%), but not to C. riparius or H. azteca. In chronic tests, mortality in H. azteca and T. tubifex was highest at 300 and 400 m, indicating that toxicity observed in the short-term aqueous exposures adequately predicted long-term toxicity in bulk sediments. In both acute and chronic tests, mortality was significantly correlated with the concentration of extractable organic chlorines (EOCl) in the sediment, with LC50 values ranging from 4500 to 5500 mg EOCl/kg organic carbon. Growth of C. tentans larvae was depressed at 300 and 400 m in August 91 but enhanced in May 93 relative to the reference sites. Growth of H.azteca also declined near the outfall in August 91 sediments and was approximately one half that observed in 92/93 sediments; however, growth did not differ among stations in 92 or 93. Reproductive output in D. magna (neonates) and T. tubifex (cocoons) was highest at 300 and 400 m. In T. tubifex, the number of hatched young was lowest at these stations. This study provides evidence that toxicity may occur in sediments exposed to BKME, and emphasizes the need to incorporate sediment toxicity bioassessment as part of efforts directed toward remedial action in the pulp and paper industry.

Use of a global test for multiple outcomes in stroke trials with application to the National Institute of Neurological Disorders and Stroke t-PA Stroke Trial

BACKGROUND

The National Institute of Neurological Disorders and Stroke (NINDS) held a workshop on statistical approaches to analysis of acute stroke trials that have multiple pre-specified outcomes. An objective was to plan for statistical analysis of the NINDS t-PA Stroke Trial, a randomized, double-blind, placebo-controlled trial of recombinant tissue plasminogen activator (rt-PA) for patients with acute ischemic stroke. Treatment success was defined as a "consistent and persuasive difference" in the proportion of patients achieving favorable outcomes on the Barthel Index, Modified Rankin Scale, Glasgow Outcome Scale, and National Institutes of Health Stroke Scale. The Data and Safety Monitoring Committee for the trial recommended this outcome because the committee did not believe that a positive result for a single outcome would provide sufficient evidence of efficacy.

SUMMARY OF COMMENT

Workshop participants accepted the global test as a viable approach to testing the primary trial hypothesis. Clinician participants advocated categorizing outcomes as favorable/unfavorable, outcomes more clinically meaningful than continuous outcomes for evaluating a drug with potentially serious side effects. They agreed that a global test was appropriate for ischemic stroke when no single outcome is accepted. Hypothetical, special-case examples illustrate that highly correlated outcomes diminish the power of the global test. NINDS t-PA Stroke Trial data demonstrate the clinical interpretability of the global test.

CONCLUSIONS

Workshop participants concluded that a global statistic should be used to test the trial's primary hypothesis accompanied by secondary tests of individual outcomes. Workshop participants recommended familiarizing the clinical/scientific community with the global approach.

Chemical-activated luciferase gene expression (CALUX): a novel in vitro bioassay for Ah receptor active compounds in sediments and pore water

This study demonstrates that the novel in vitro CALUX (chemical-activated luciferase expression) assay is a rapid, sensitive assay for assessing the toxic potency of (mixtures of) aryl hydrocarbon receptor (AhR)-active compounds in sediments and pore waters. A rat hepatoma (H4IIE) cell line, stably transfected with a construct containing the dioxin-responsive element (DRE) sequence and the luciferase reporter gene, was used to determine the relative potency or the total activities of AhR-active compounds in sediment and pore water extracts. This novel CALUX assay had a detection limit of 0.5 fmol of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The sensitivity and linear working range was slightly better than for the ethoxyresorufin O-deethylase (EROD) assay in H4IIE wild type cells. The primary improvement of the CALUX assay compared to the EROD assay, however, is that the CALUX assay is insensitive to substrate inhibition. The CALUX activity induced by organic extracts from 450-mg aliquots of sediment or 250-microl aliquots of pore water corresponded with the instrumentally analyzed degree of pollution of the sediment. Using pore water, only a simple and rapid extraction procedure was needed, without additional clean-up to prevent cell death. The response from pore water samples in an 8-day early life stage test with zebra fish (Branchydanio rerio) corresponded with the CALUX induction, although the correlation was sometimes disturbed by heavy metals. Two polychlorinated terphenyl mixtures, the PCB-substitute Ugilec 141, polybrominated diphenylethers, and the PCB-mixture Clophen A50 were tested in the CALUX assay and had induction potencies that were 10(-4)-10(-7) compared to TCDD.