Current ecotoxicity testing needs among selected U.S. federal agencies

U.S. regulatory and research agencies use ecotoxicity test data to assess the hazards associated with substances that may be released into the environment, including but not limited to industrial chemicals, pharmaceuticals, pesticides, food additives, and color additives. These data are used to conduct hazard assessments and evaluate potential risks to aquatic life (e.g., invertebrates, fish), birds, wildlife species, or the environment. To identify opportunities for regulatory uses of non-animal replacements for ecotoxicity tests, the needs and uses for data from tests utilizing animals must first be clarified. Accordingly, the objective of this review was to identify the ecotoxicity test data relied upon by U.S. federal agencies. The standards, test guidelines, guidance documents, and/or endpoints that are used to address each of the agencies' regulatory and research needs regarding ecotoxicity testing are described in the context of their application to decision-making. Testing and information use, needs, and/or requirements relevant to the regulatory or programmatic mandates of the agencies taking part in the Interagency Coordinating Committee on the Validation of Alternative Methods Ecotoxicology Workgroup are captured. This information will be useful for coordinating efforts to develop and implement alternative test methods to reduce, refine, or replace animal use in chemical safety evaluations.

The Eco-Exposome Concept: Supporting an Integrated Assessment of Mixtures of Environmental Chemicals

Organisms are exposed to ever-changing complex mixtures of chemicals over the course of their lifetime. The need to more comprehensively describe this exposure and relate it to adverse health effects has led to formulation of the exposome concept in human toxicology. Whether this concept has utility in the context of environmental hazard and risk assessment has not been discussed in detail. In this Critical Perspective, we propose-by analogy to the human exposome-to define the eco-exposome as the totality of the internal exposure (anthropogenic and natural chemicals, their biotransformation products or adducts, and endogenous signaling molecules that may be sensitive to an anthropogenic chemical exposure) over the lifetime of an ecologically relevant organism. We describe how targeted and nontargeted chemical analyses and bioassays can be employed to characterize this exposure and discuss how the adverse outcome pathway concept could be used to link this exposure to adverse effects. Available methods, their limitations, and/or requirement for improvements for practical application of the eco-exposome concept are discussed. Even though analysis of the eco-exposome can be resource-intensive and challenging, new approaches and technologies make this assessment increasingly feasible. Furthermore, an improved understanding of mechanistic relationships between external chemical exposure(s), internal chemical exposure(s), and biological effects could result in the development of proxies, that is, relatively simple chemical and biological measurements that could be used to complement internal exposure assessment or infer the internal exposure when it is difficult to measure. Environ Toxicol Chem 2022;41:30-45. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Reliability of In Vitro Methods Used to Measure Intrinsic Clearance of Hydrophobic Organic Chemicals by Rainbow Trout: Results of an International Ring Trial

In vitro assays are widely employed to obtain intrinsic clearance estimates used in toxicokinetic modeling efforts. However, the reliability of these methods is seldom reported. Here we describe the results of an international ring trial designed to evaluate two in vitro assays used to measure intrinsic clearance in rainbow trout. An important application of these assays is to predict the effect of biotransformation on chemical bioaccumulation. Six laboratories performed substrate depletion experiments with cyclohexyl salicylate, fenthion, 4-n-nonylphenol, deltamethrin, methoxychlor, and pyrene using cryopreserved hepatocytes and liver S9 fractions from trout. Variability within and among laboratories was characterized as the percent coefficient of variation (CV) in measured in vitro intrinsic clearance rates (CLIN VITRO, INT; ml/h/mg protein or 106 cells) for each chemical and test system. Mean intralaboratory CVs for each test chemical averaged 18.9% for hepatocytes and 14.1% for S9 fractions, whereas interlaboratory CVs (all chemicals and all tests) averaged 30.1% for hepatocytes and 22.4% for S9 fractions. When CLIN VITRO, INT values were extrapolated to in vivo intrinsic clearance estimates (CLIN VIVO, INT; l/d/kg fish), both assays yielded similar levels of activity (<4-fold difference for all chemicals). Hepatic clearance rates (CLH; l/d/kg fish) calculated using data from both assays exhibited even better agreement. These findings show that both assays are highly reliable and suggest that either may be used to inform chemical bioaccumulation assessments for fish. This study highlights several issues related to the demonstration of assay reliability and may provide a template for evaluating other in vitro biotransformation assays.

Primary central nervous system posttransplantation lymphoproliferative disorder after heart and lung transplantation

Primary central nervous system posttransplantation lymphoproliferative disorder (PCNS-PTLD) is uncommon, especially after heart or lung transplantation. Database analysis from a single heart and lung transplantation centre and a literature review pertaining to PCNS-PTLD was performed. In this study, the prevalence of PCNS-PTLD was 0.18% after heart and/or lung transplants. Of 1674 transplants, three cases of PCNS-PTLD developed 14 months, 9 years and 17 years posttransplant, and all were Epstein-Barr virus driven malignancies. Literature review of the topic revealed predominantly retrospective studies, with most reported cases after renal transplantation. The overall survival is poor, and it may be improved by early diagnosis and treatment. There are no published guidelines on the management of PCNS-PTLD; immune-chemotherapy in conjunction with reduction of immune suppression is preferred based on available evidence.

Hepatosplenic T-cell lymphoma, immunosuppressive agents and biologicals: what are the risks?

We present three cases of the rare hepatosplenic T-cell lymphoma (HSTCL); two patients suffering from Crohn disease who developed HSTCL on azathioprine without exposure to biologicals, and a third patient who had psoriasis treated using etanercept, cyclosporine and methotrexate. The evidence for an association between HSTCL and immunosuppressive drugs and biologicals is reviewed. We argue for improved pharmacovigilance processes to help determine the benefit to risk ratios for the use of these and other new agents.

Acute effects of prostaglandin E1 and E2 on vascular reactivity and blood flow in situ in the chick chorioallantoic membrane

The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE(1&2) for vascular effects and signaling in the CAM. Application of PGE(1&2) induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP(2-4), and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP(3) and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo.

The association between sports participation and athletic identity with eating pathology among college-aged males and females

The current study examined associations among sports participation (SP), athletic identity (AI), weight status, and eating pathology, and whether these relations differed by gender. Data come from male and female first-year college students who participated in the Tufts Longitudinal Health Study (TLHS) between 1999-2007 (N=712). Relations among SP, AI, actual and perceived weight statuses, Eating Disorders Inventory (EDI) subscale scores, and indices of body shape concern and restrictive eating were examined with hierarchical ordinary least squares (OLS) regression. Associations between SP and eating pathology among females were moderated by perceived weight status. By contrast, relations between males' EDI subscales scores and SP were moderated by ethnicity, as well as by actual weight status. Our findings support that sports participation alone neither promotes nor protects against eating pathology among males and females.

Allogeneic hematopoietic SCT as treatment option for patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE): a consensus conference proposal for a standardized approach

Allogeneic hematopoietic SCT (HSCT) has been proposed as a treatment for patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). HSCT has been performed in nine patients using different protocols with varying success. Based on this preliminary experience, participants of the first consensus conference propose a common approach to allogeneic HSCT in MNGIE. Standardization of the transplant protocol and the clinical and biochemical assessments will allow evaluation of the safety and efficacy of HSCT as well as optimization of therapy for patients with MNGIE.

Upregulation of calcium-sensing receptor and mitogen-activated protein kinase signalling in the regulation of growth and differentiation in colon carcinoma

In the present study, we demonstrate that Ca²⁺-induced growth inhibition and induction of differentiation in a line of human colon carcinoma cells (CBS) is dependent on mitogen-activated protein (MAP) kinase signaling and is associated with upregulation of extracellular calcium-sensing receptor (CaSR) expression. When CBS cells were grown in Ca²⁺-free medium and then switched to medium supplemented with 1.4 mM Ca²⁺, proliferation was reduced and morphologic features of differentiation were expressed. E-cadherin, which was minimally expressed in nonsupplemented medium, was rapidly induced in response to Ca²⁺ stimulation. Sustained activation of the extracellular signal-regulated kinase (ERK) occured in Ca²⁺-supplemented medium. When an inhibitor of ERK activation (10 μM U0126) was included in the Ca²⁺-supplemented culture medium, ERK-activation did not occur. Concomitantly, E-cadherin was not induced, cell proliferation remained high and differentiation was not observed. The same level of Ca²⁺ supplementation that induced MAP kinase activation also stimulated CaSR upregulation in CBS cells. A clonal isolate of the CBS line that did not upregulate CaSR expression in response to extracellular Ca²⁺ was isolated from the parent cells. This isolate failed to produce E-cadherin or undergo growth inhibition/induction of differentiation when exposed to Ca²⁺ in the culture medium. However, ERK-activation occurred as efficiently in this isolate as in parent CBS cells or in a cloned isolate that underwent growth reduction and differentiation in response to Ca²⁺ stimulation. Together, these data indicate that CaSR upregulation and MAP kinase signalling are both intermediates in the control of colon carcinoma cell growth and differentiation. They appear to function, at least in part, independently of one another.

Antagonism of Epidermal Growth Factor Receptor Tyrosine Kinase Ameliorates the Psoriatic Phenotype in Organ-Cultured Skin

Psoriatic plaque skin incubated for eight days in organ culture in the presence of a potent epidermal growth factor (EGF) receptor tyrosine kinase (RTK) antagonist reverted to a more normal histological appearance, while untreated psoriatic plaque skin retained histological features associated with the psoriatic phenotype. In concomitant studies it was shown that the EGF-RTK antagonist had no significant effect on histological features of non-psoriatic skin and no effect on dermal function, i.e. elaboration of both type I procollagen and matrix metalloproteinase-1 (MMP-1; interstitial collagenase). When human epidermal keratinocytes were treated with the EGF-RTK antagonist in monolayer culture, growth inhibition was seen (ED(50) = approximately 0.06 microM). When dermal fibroblasts were exposed to the EGF-RTK antagonist in monolayer culture, proliferation, MMP-1 and type I procollagen production were essentially unaffected at concentrations which interfered with keratinocyte growth (up to 1 microM). The capacity of the EGF-RTK antagonist to modulate the histological features of psoriatic skin in organ culture under conditions in which normal skin architecture and dermal function are largely unaffected suggests a potential for anti-psoriatic therapy.

Statistical parameters in behavioral tasks and implications for sample size of C57BL/6J:129S6/SvEvTac mixed strain mice

Most mixed strain progeny from gene-knockout experiments typically originate from C57BL/6J and one of the 129 substrains, frequently 129S6/SvEvTac. The results of this behavioral survey suggest that C57BL/6J:129S6/SvEvTac mixed strain mice are amenable to behavioral testing. The variability in behavioral tasks for subjects arising from this mixed strain genetic background does not preclude screening with a battery of behavioral tests. With clues provided by a screen of mixed strain subjects, follow-up analyses with isogenic, congenic, or F1 hybrid animals may be targeted to specific behavioral themes.

Prenatal diagnosis of congenital myotonic dystrophy and counseling of the pregnant mother: case report and literature review

The molecular basis of the myotonic dystrophy (MD) kinase gene is expansion of the CTG repeat at the 3'-untranslated region of the MD gene. Variability of the CTG repeat size in different tissues of affected individuals has been demonstrated. The objective of this report was to examine and review the feasibility of prenatal diagnosis of congenital myotonic dystrophy (CMD) in pregnant women with MD using CTG repeat sizes in amniocytes or villi. We present a case of a pregnant woman with MD who underwent prenatal diagnosis of MD using amniocytes. The repeat size in the amniocytes was smaller than the repeat size in the maternal leukocytes and smaller than the repeat size in the infant blood. The infant had CMD. We also reviewed the literature for reports on MD cases that were prenatally tested for CTG repeat size using amniocytes or chorionic villi. Data were tabulated based on the number of maternal CTG repeats, prenatal procedure [amniocentesis or chorionic villus sampling (CVS)], CTG repeat size in fetal tissue, fetal/infant blood, and pregnancy outcome. Twenty-seven pregnancies at risk for MD that underwent prenatal diagnosis were reported. Eleven (40.7%) of the 27 pregnancies underwent amniocentesis, and 16 (59.3%) underwent CVS. Fourteen patients (61%) demonstrated an increase in CTG repeat size in the amniocytes or villi compared with the maternal repeat size. Nine (33%) of the 27 pregnancies were terminated because of CMD risk. The outcomes of 11 (40.7%) pregnancies were consistent with diagnosis of CMD. CMD was diagnosed in fetuses demonstrating expansion or contraction of the CTG mutation in the amniocytes. Prenatal diagnosis of MD is possible by using mutation analysis on maternal and fetal DNA and detection of the CTG repeat expansion. Prenatal diagnosis of CMD is more complex. The possible lack of correlation between CTG repeat size in amniocytes, villi, and other fetal tissues is a potential limitation in prenatal diagnosis and counseling of CMD using CTG repeat size. Thus, prenatal diagnosis of CMD should be based on a combination of factors, including maternal pregnancy history, clinical findings, and cautious interpretation of maternal and fetal DNA analysis.

Lenograstim administration to HLA-identical donor-recipient pairs to accelerate marrow recovery post-transplant

In an attempt to accelerate marrow recovery after HLA-identical sibling bone marrow transplantation, the donors of 12 patients with haematological malignancy were given recombinant human granulocyte colony-stimulating factor (rHuG-CSF; lenograstim; Granocyte) 5 micrograms/kg/day for seven doses prior to marrow harvest. All 12 recipients also received lenograstim 5 micrograms/kg/day from the day of transplant until their neutrophil count was 1.0 x 10(9)/1. In addition to lenograstim post-transplant and lenograstim-stimulated donor bone marrow the first six recipients also received donor peripheral blood stem cells that had been enriched for CD34+ stem/progenitor cells and T cell depleted on an immune absorption column (cohort 1). The second six patients (cohort 2) received lenograstim post-transplant and lenograstim-stimulated donor marrow only. All 12 patients showed a marked elevation of their circulating white blood cell count (predominantly neutrophils) on day 1 post-transplant. Compared to carefully matched historical control patients the rate of neutrophil engraftment was significantly accelerated in both patient cohorts and platelet engraftment was accelerated in cohort 2.

[What can family physicians contribute to health promotion in schools?]

Although several German schools have developed and tested concepts of a goal-directed health education, a stable and continuous implementation is missing. In this field free-practising physicians can support public health efforts. In the area Bruchsal/Ostringen it is demonstrated, that especially those primary care physicians, who work according to the "Three-Level-Concept of Free-Practising Physicians", can successfully use their geographical and social proximity to schools in their neighbourhood for a log-lasting implementation of recurring health-related activities. Within ten years 1389 students in schools, further ca. 500 outside schools, were directly included in interactive learning in the framework of preventive measures, e.g. during school health days. 10 physicians (4 of them continuously) cooperated in these activities, which had been planned in close collaboration with teachers and parents, considering the different age groups. From the very beginning--although sometimes limited in scale--each activity was evaluated. Pupils in the age group 10-12 years generally showed the highest interest in health-related diet, 17-26% were physically more active. Promising are the results with respect to smoking: one fifth of the smoking students intended to quit as a consequence of the health activities in their schools.

Autologous blood stem cell transplantation for haematological malignancy: treatment-related mortality of 2%

BACKGROUND

Lengthy remission or cure has remained elusive for patients with many of the common haematological malignancies. Thus high dose chemotherapy followed by autologous haemopoietic stem cell transplantation is being increasingly utilised in these diseases.

AIM

To assess the safety of high dose chemotherapy and autologous stem cell transplantation in haematological malignancy.

METHODS

Forty-eight patients with haematological malignancy were given high dose chemotherapy followed by an infusion of previously cryopreserved autologous peripheral blood stem cells with (patients with acute myeloid leukaemia [AML]) or without (patients with acute lymphoblastic leukaemia [ALL], chronic myeloid leukaemia, non-Hodgkin's lymphoma, Hodgkin's disease and myeloma) autologous bone marrow.

RESULTS

All patients except one had sustained engraftment. The median (range) number of days to attain a neutrophil count of 0.5 x 10(9)/L was 12 (10-42) and a platelet count of 20 x 10(9)/L unsupported by platelet transfusions was 15 (eight to 155). Other than oropharyngeal mucositis and febrile neutropenia, morbidity was low. Two patients had haemorrhagic cystitis, one hepatic veno-occlusive disease and one interstitial pneumonitis; all resolved. The treatment-related mortality was 2%--a single patient with AML died of failure of sustained engraftment.

CONCLUSIONS

Autologous blood stem cell transplantation to support high dose chemotherapy is a relatively safe procedure and its efficacy is currently being explored in a wide range of haematological malignancies.