Margret Schlumpf

Catecholamines in mutant mouse cerebellum. Fluorescence microscopic and chemical studies.

Catecholamine-containing fibers have been examined in the cerebella of normal and hypocerebellar mutant mice using Falck-Hillarp and glyoxylic acid histofluorescence techniques. The amounts of norepinephrine and dopamine were also determined chemically in the same mutants. Green fluorescent fibers in cerebella of normal mice are similar in size and distribution to those described in the rat. Weanling and adult weaver, reeler and staggerer mice all manifest greatly increased specific catecholamine fluorescence per unit area in cerebellar cortex, but the patterns of fluorescent fibers are distinctive. In weaver, the fibers are of normal diameter, surround Purkinje cell bodies and appear to climb along major dendrites. In reeler, similar fibers form a plexus around cortical and non-cortical Purkinje cells; relatively normal fluorescent fiber patterns are present in well-organized cortical regions, while stouter disoriented fibers course through the shallow molecular layer in disorganized regions. Staggerer cerebellar cortex exhibits the greatest fluorescence with most terminals appearing as matted tangles adjacent cell bodies. Clearly defined fibers, however, can be distinguished in the molecular layer running perpendicular to the pia or for long distances in the coronal plane parallel to the pia. The major catecholamine determined chemically is norepinephrine. Reeler cerebella contain normal absolute levels and a doubled concentration of norepinephrine. In contrast, and despite the fluorescence findings, the total norepinephrine content of weaver and staggerer cerebella is significantly reduced and concentrations are not significantly different from normal.

Estrogen Sensitivity of Target Genes and Expression of Nuclear Receptor Co-Regulators in Rat Prostate after Pre- and Postnatal Exposure to the Ultraviolet Filter 4-Methylbenzylidene Camphor

BACKGROUND AND OBJECTIVES In previous studies, we found that the ultraviolet filter 4-methyl-benzylidene camphor (4-MBC) exhibits estrogenic activity, is a preferential estrogen receptor (ER)-beta ligand, and interferes with development of female reproductive organs and brain of both sexes in rats. Here, we report effects on male development. METHODS 4-MBC (0.7, 7, 24, 47 mg/kg/day) was administered in chow to the parent generation before mating, during gestation and lactation, and to offspring until adulthood. mRNA was determined in prostate lobes by real-time reverse transcription-polymerase chain reaction and protein was determined by Western blot analysis. RESULTS 4-MBC delayed male puberty, decreased adult prostate weight, and slightly increased testis weight. Androgen receptor (AR), insulin-like growth factor-1 (IGF-1), ER-alpha, and ER-beta expression in prostate were altered at mRNA and protein levels, with stronger effects in dorsolateral than ventral prostate. To assess sensitivity of target genes to estrogens, offspring were castrated on postnatal day 70, injected with 17beta-estradiol (E(2); 10 or 50 microg/kg, sc) or vehicle on postnatal day 84, and sacrificed 6 hr later. Acute repression of AR and IGF-1 mRNAs by E(2), studied in ventral prostate, was reduced by 4-MBC exposure. This was accompanied by reduced co-repressor N-CoR (nuclear receptor co-repressor) protein in ventral and dorsolateral prostate, whereas steroid receptor coactivator-1 (SRC-1) protein levels were unaffected. CONCLUSIONS Our data indicate that 4-MBC affects development of male reproductive functions and organs, with a lowest observed adverse effect level of 0.7 mg/kg. Nuclear receptor coregulators were revealed as targets for endocrine disruptors, as shown for N-CoR in prostate and SRC-1 in uterus. This may have widespread effects on gene regulation.

Region-specific growth effects in the developing rat prostate following fetal exposure to estrogenic ultraviolet filters.

Background and objectives Exposure to environmental endocrine disruptors is a potential risk factor for humans. Many of these chemicals have been shown to exhibit disruption of normal cellular and developmental processes in animal models. Ultraviolet (UV) filters used as sunscreens in cosmetics have previously been shown to exhibit estrogenic activity in in vitro and in vivo assays. We examined the effects of two UV filters, 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor (3-BC), in the developing prostate of the fetal rat. Methods Pregnant Long Evans rats were fed diets containing doses of 4-MBC and 3-BC that resulted in average daily intakes of these chemicals corresponding to the lowest observed adverse effects level (LOAEL) and the no observed adverse effects level (NOAEL) doses in prior developmental toxicity studies. Using digital photographs of serial sections from postnatal day 1 animals, we identified, contoured, and aligned the epithelial ducts from specific regions of the developing prostate, plus the accessory sex glands and calculated the total volume for each region from three-dimensional, surface-rendered models. Results Fetal exposure to 4-MBC (7.0 mg/kg body weight/day) resulted in a significant increase (p < 0.05) in tissue volume in the prostate and accessory sex glands. Treated males exhibited a 62% increase in the number of ducts in the caudal dorsal prostate. Increased distal branching morphogenesis appears to be a consequence of exposure in the ventral region, resulting in a 106% increase in ductal volume. Conclusions 4-MBC exposure during development of the male reproductive accessory sex glands exhibited classical growth effects associated with estrogenic endocrine disruptors. The different regional responses suggest that the two developmental processes of ductal outgrowth and branching morphogenesis are affected independently by exposure to the environmental chemicals.

Salbutamol exhibits androgenic activity in vitro

Background: Salbutamol has been shown to mediate anabolic effects after intravenous administration. However, the mechanism responsible for the anabolic actions of salbutamol remains unknown. Aim: To investigate the potential mechanism by which salbutamol mediates anabolic effects in vitro. Methods: The potential androgenic activity of salbutamol was investigated in vitro by the A-Screen assay that measures androgen-dependent inhibition of proliferation of the androgen receptor (AR)-positive human mammary carcinoma cell line, MCF7-AR1. Results: The assay was validated with three known androgens; methyltrienolone (R1881), 5α-dihydrotestosterone (DHT) and danazol. IC50 values of R1881, DHT and danazol, 4.41×10−11, 4.44×10−11 and 1.08×10−8 M, respectively, were in the ranges known from earlier studies. Our results demonstrate that salbutamol exhibits androgenic activity, with an IC50 value of 8.93×10−6 M. Anti-estrogenic or cytotoxic effects, which might have interfered with the assay, were excluded by additional experiments on wild-type MCF7 and MCF7-AR1 cells, respectively. Conclusion: These data indicate that salbutamol exerts anabolic effects through androgen receptor agonistic activity in vitro.

Permanent alteration of peptide feedback on dopamine neurons after injection of α-melanotropin antiserum at a critical period of postnatal development

Tonic inhibition of alpha-MSH secretion by the tubero-hypophyseal dopamine (DA) neurons of the rat starts at the end of the first postnatal week, after a peak in plasma MSH at days 5 and 6. In order to obtain information on the maturation of central control, we studied the development of alpha-MSH feedback on DA neurons and the possible role of circulating peptide. The characteristic response of these DA neurons to i.p. alpha-MSH, i.e., an acute rise in cellular fluorescence intensity as determined by microfluorimetry, was not yet detected at day 4 but present at day 8. When rats were injected i.v. with antiserum to alpha-MSH on days 5 and 6 and tested as adults, their DA neurons failed to react to i.p. alpha-MSH (2-100 micrograms/kg), but they were still responsive to prolactin (600 micrograms/kg). The DA system was already unresponsive to alpha-MSH at postnatal day 8. Antiserum injection on days 11 and 12, when plasma MSH is low, did not affect the reaction of DA neurons to alpha-MSH on day 14. These developmental processes were analogous in both sexes. Injections of control serum were ineffective. Our observations indicate that the feedback reaction of DA neurons to alpha-MSH develops in conjunction with the onset of inhibitory control of MSH release. The presence of alpha-MSH during a critical period appears to be necessary for the development of the responsiveness of DA neurons to the peptide hormone.

Fundamental questions to sun protection: A continuous education symposium on vitamin D, immune system and sun protection at the University of Zürich.

Since exposure to sunlight is a main factor in the development of non-melanoma skin cancer and there are associations between malignant melanoma and short-term intense ultraviolet (UV) exposure, particularly burning in childhood, strict protection from UV-radiation is recommended. However, up to 90% of all requisite vitamin-D has to be formed within the skin through the action of the sun - a serious problem, for a connection between vitamin-D deficiency, demonstrated in epidemiological studies, and various types of cancer and other diseases has been confirmed. A UVB-triggered skin autonomous vitamin D3 synthesis pathway has recently been described, producing the active Vitamin D metabolite calcitriol. This cutaneous vitamin D3 pathway is unique. Keratinocytes and dendritic cells can convert vitamin D to calcitriol. Cutaneous T cells activated in the presence of calcitriol express the chemokine receptor CCR10 attracting them to the chemokine CCL27 that keratinocytes express selectively in the epidermis, and migrate from dermal layers of the skin to the epidermis under UV radiation. Thus, calcitriol has endocrine roles beyond its calciotropic action, including cell growth and cancer prevention. Therefore, strict sun protection procedures to prevent skin cancer may induce the risk of vitamin-D deficiency. As there is evidence that the protective effect of less intense solar radiation can outweigh its mutagenic effect, better balanced approaches to sun protection should be sought.

Efficiency control of dietary pesticide intake reduction by human biomonitoring

In spite of food safety controls for pesticide residues, a conventional diet still leads to a noticeable exposure of the general population to several pesticides. In a pilot study the response of exposure reduction by organic diet intervention on the urinary levels of pesticide metabolites was investigated. In the study two adult individuals were kept on a conventional diet for 11days and morning urine voids were collected at the last four days of the period. Afterwards, the participants switched to exclusively organic food intake for 18days and likewise morning urine samples were collected at the last four days of this period. In the urine samples six pyrethroid metabolites, six dialkylphosphates, four phenolic parameter for organophosphate pesticides and carbamates, 6-chloronicotinic acid (ClNA) as parameter for neonicotinoid insecticides, seven phenoxy herbicides, glyphosate and its metabolite AMPA were quantified using gas chromatographic mass spectrometric methods. Generally, the comparative analyses revealed greater shares as well as higher levels of the parameters in the samples taken during the common diet period compared to the organic diet period. Considerable decrease of the levels was found for almost all pyrethroid metabolites, dialkyphosphates and phenoxy herbicids, as well as for the phenolic metabolites 4-nitrophenol and 3,5,6-trichloropyridinol. In contrast, higher values were found for the organic diet period for ClNA and the metabolite of coumaphos in one of the volunteers. The present study confirms the results of former studies which indicated that an organic diet intervention results in considerable lower exposure to organophosphate pesticides and pyrethroids. It also verifies the former experience that monitoring of urinary parameters for non-persistent pesticides permits a reliable efficiency control of short-time effects by dietary interventions. Additionally to former studies, the results of the present study highlight the need of an extension of the parameter spectrum to all prominent pesticide groups.

Hormonaktive Xenobiotika: Störungen von Fortpflanzungs- und Entwicklungsprozessen

ZusammenfassungFortpflanzungs- und Entwicklungsprozesse reagieren am empfindlichsten auf toxische Wirkungen von Umweltchemikalien. Als speziell besorgniserregend gilt die Störung der Wirkung von Hormonen durch verschiedene Gruppen von Pestiziden und Industriechemikalien. Grund zur Sorge geben der in Europa beobachtete Trend zur Verminderung der Spermienproduktion und weitere Reproduktionsstörungen beim Mann und bei der Frau, aber auch die alarmierende Zunahme von Reproduktions- und Entwicklungsstörungen bei Tieren in der freien Wildbahn. Bei der Frau und bei verschiedenen Tierarten ist ein Zusammenhang mit der Belastung durch hormonaktive Umweltchemikalien nachgewiesen worden.Neuere Studien zeigen deutlich, wie wichtig der Zeitpunkt der Einwirkung von Fremdsubstanzen für die Auswirkung auf den Organismus ist. Im Erwachsenenalter üben Hormone eine aktivierende Wirkung aus, d.h. sie stimulieren oder hemmen Organfunktionen vorübergehend. In der frühen Entwicklung dagegen üben Hormone organisierende Wirkungen aus. Sie steuern bestimmte Entwicklungsprozesse und bewirken dadurch permanente Veränderungen in Struktur und Funktion von Organen. Interagieren Fremdstoffe während der Entwicklung mit Wirkungen von Hormonen, kann es zu bleibenden Funktionsstörungen von Organen kommen.AbstractDevelopmental and reproductive processes are most sensitive to the toxic effects of environmental chemicals. Especially alarming is the fact that many groups of industrial chemicals and pesticides are capable of disrupting the endocrine system in man and animals. Of great concern is the reduction in the sperm count in Europe, but also the worldwide increase in a great number of reproductive and developmental disturbances observed in both man and wildlife. A correlation to a high chemical burden has been demonstrated for many different animal species as well as for women.An important consideration in assessing the potential effects of environmental chemicals on the endocrine system is the time at which such an exposure occurs. In the adult organism, hormones initiate functional processes; these effects are usually transient. In early life, hormones control developmental processes and are capable of producing permanent changes in organ structure and function (organizational effects). Therefore, chemical disruption of hormonal functions during development can result in permanent functional changes of the afflicted organ.

The legacy of pesticides and POPs stockpiles—a threat to health and the environment

The unsustainable life cycle management of pesticides in the last 70 years has created large pesticide stockpiles. The two major working areas of the International HCH & Pesticides Association (IHPA; www.ihpa.info) partly address these legacies: (1) assess and support the management of the world’s single largest persistent organic pollutants (POPs) stockpile: the 4 to 7 million tonnes (t) of hexachlorocyclohexane (HCH) wastes dumped globally from lindane production (Vijgen et al. 2011; Vijgen et al. 2013) and (2) support the management of the ~ 240,000 t of obsolete pesticides legacy in Eastern Europe, the Caucasus and Central Asia (EECCA) countries, where these pesticides are stored without adequate safety control, posing huge risks to the environment and human health (Vijgen et al. 2013). As a major part of its approach, the IHPA organizes of the biannual BInternational HCH and Pesticides Forum^ bringing together researchers, policymakers, government institutions, industry, civil society, and donors from different parts of the world for discussion on issues related to pesticide/POPs pollution and related solutions. This special issue of Environmental Science Pollution Research includes selected papers from the 13th HCH and Pesticides Forum held in Zaragoza, Spain, as well as selected contemporary case studies on POPs. The 13th Forum was organized in Zaragoza to draw international attention to the enormous environmental and financial problems in the region of Aragon (Spain) due to the former production of Lindane by Inquinosa and the unregulated dumping of more than 100,000 t of HCH-waste around Sabiñánigo and the Gállego River (Fernandez et al. 2013; De La Torre et al. 2018). From 2014 to 2016, a total of 65,000 t of HCH solid waste and 342,000 t of polluted soil were transferred to a new sanitary landfill with isolating measures beyond the Spanish legal requirements (De La Torre et al. 2018). The Forum agenda included disseminating the Aragon authorities’ experiences with addressing this problem and transferring this knowledge to the EECCA countries and other interested countries with similar HCH-waste problems (Vijgen et al. 2011; IHPA 2015a, b). Assessing the pollution situation, the relevance to human exposure, and possible improvements using available management and scientific measures remains a key challenge for developing and transition economies. In this special issue, three contributions (Toichuev et al. 2017a,b; Doolotkeldieva et al. 2017) document in detail the situation of POPs pesticide legacy in the Kyrgyz Republic. Toichuev (academy of science), together with the NGO Green Cross and TAUW company, describes the preliminary assessment and activities to secure the largest and most hazardous POPs pesticides dumping sites in Kyrgyzstan, where cattle died and the local population has high pesticide levels in blood, breastmilk, and placenta (Toichuev et al. 2017a). This study also reports on practical risk reduction measures carried out within a UN project and provides further recommendations on monitoring and assessment, including the suggestion to consider the findings of the study in the National Implementation Plan of Kyrgyzstan (Toichuev et al. 2017a). Toichuev and colleagues from the National Academy of Sciences of the Kyrgyz Republic analyzed organochlorine pesticides (OCPs) in 241 placentas from cotton-growing regions, 121 placentas from an urban area (city of Osh), and 146 placentas from unpolluted mountain regions of Kyrgyzstan. The relative risk of health problems in both, mothers and newborns increased significantly, in a concentrationdependent manner, with increasing levels of total OCPs Responsible editor: Philippe Garrigues

Fundamental questions to sun protection

Since exposure to sunlight is a main factor in the development of non-melanoma skin cancer and there are associations between malignant melanoma and short-term intense ultraviolet (UV) exposure, particularly burning in childhood, strict protection from UV-radiation is recommended. However, up to 90% of all requisite vitamin-D has to be formed within the skin through the action of the sun - a serious problem, for a connection between vitamin-D deficiency, demonstrated in epidemiological studies, and various types of cancer and other diseases has been confirmed. A UVB-triggered skin autonomous vitamin D3 synthesis pathway has recently been described, producing the active Vitamin D metabolite calcitriol. This cutaneous vitamin D3 pathway is unique. Keratinocytes and dendritic cells can convert vitamin D to calcitriol. Cutaneous T cells activated in the presence of calcitriol express the chemokine receptor CCR10 attracting them to the chemokine CCL27 that keratinocytes express selectively in the epidermis, and migrate from dermal layers of the skin to the epidermis under UV radiation. Thus, calcitriol has endocrine roles beyond its calciotropic action, including cell growth and cancer prevention. Therefore, strict sun protection procedures to prevent skin cancer may induce the risk of vitamin-D deficiency. As there is evidence that the protective effect of less intense solar radiation can outweigh its mutagenic effect, better balanced approaches to sun protection should be sought.