Identification of aspartame-induced haematopoietic and lymphoid tumours in rats after lifetime treatment.

Lymphomas and leukaemias involving the lung have in some cases been hard to distinguish from respiratory tract infection in Sprague-Dawley (SD) rats from long-term bioassays. In order to differentiate between tumours and immune cell infiltrates, updated pathological criteria and nomenclature were used and immunohistochemistry (IHC) was applied to haematopoietic and lymphoid tissue tumours (HLTs) in the original prenatal long-term Aspartame (APM) study performed by the Ramazzini Institute (RI). All 78 cases of HLTs from treated and control groups were re-examined based on light microscopic morphological characteristics and subjected to a panel of IHC markers including Ki67, CD3, PAX5, CD20, CD68, TdT, CD45, CD14 and CD33. The analysis confirmed the diagnoses of HLTs in 72 cases, identified 3 cases of preneoplastic lesions (lymphoid hyperplasia), and categorized 3 cases as inflammatory lesions. A statistically significant increase in total HLTs (p = 0.006), total lymphomas (p = 0.032) and total leukaemias (p = 0.031) in treated female rats was confirmed (high dose vs control), and a statistically significant linear trend for each HLT type was also observed. After the HLT cases re-evaluation, the results obtained are consistent with those reported in the previous RI publication and reinforce the hypothesis that APM has a leukaemogenic and lymphomatogenic effect.

The Ramazzini Institute 13-week pilot study glyphosate-based herbicides administered at human-equivalent dose to Sprague Dawley rats: effects on development and endocrine system.

BACKGROUND: Glyphosate-based herbicides (GBHs) are broad-spectrum herbicides that act on the shikimate pathway in bacteria, fungi, and plants. The possible effects of GBHs on human health are the subject of an intense public debate for both its potential carcinogenic and non-carcinogenic effects, including potential effects on the endocrine system The present pilot study examine whether exposure to GBHs at the dose of glyphosate considered to be "safe" (the US Acceptable Daily Intake - ADI - of 1.75 mg/kg bw/day), starting from in utero life, affect the development and endocrine system across different life stages in Sprague Dawley (SD) rats. METHODS: Glyphosate alone and Roundup Bioflow, a commercial brand of GBHs, were administered in drinking water at 1.75 mg/kg bw/day to F0 dams starting from the gestational day (GD) 6 (in utero) up to postnatal day (PND) 120. After weaning, offspring were randomly distributed in two cohorts: 8 M + 8F/group animals belonging to the 6-week cohort were sacrificed after puberty at PND 73 ± 2; 10 M + 10F/group animals belonging to the 13-week cohort were sacrificed at adulthood at PND 125 ± 2. Effects of glyphosate or Roundup exposure were assessed on developmental landmarks and sexual characteristics of pups. RESULTS: In pups, anogenital distance (AGD) at PND 4 was statistically significantly increased both in Roundup-treated males and females and in glyphosate-treated males. Age at first estrous (FE) was significantly delayed in the Roundup-exposed group and serum testosterone concentration significantly increased in Roundup-treated female offspring from the 13-week cohort compared to control animals. A statistically significant increase in plasma TSH concentration was observed in glyphosate-treated males compared with control animals as well as a statistically significant decrease in DHT and increase in BDNF in Roundup-treated males. Hormonal status imbalances were more pronounced in Roundup-treated rats after prolonged exposure. CONCLUSIONS: The present pilot study demonstrate that GBHs exposure, from prenatal period to adulthood, induced endocrine effects and altered reproductive developmental parameters in male and female SD rats. In particular, it was associated with androgen-like effects, including a statistically significant increase of AGDs in both males and females, delay of FE and increased testosterone in female.

Erratum: "An Integrated Experimental Design for the Assessment of Multiple Toxicological End Points in Rat Bioassays".

[This corrects the article DOI: 10.1289/EHP419.].

An Integrated Experimental Design for the Assessment of Multiple Toxicological End Points in Rat Bioassays.

BACKGROUND: For nearly five decades long-term studies in rodents have been the accepted benchmark for assessing chronic long-term toxic effects, particularly carcinogenicity, of chemicals. The European Food Safety Authority (EFSA) and the World Health Organization (WHO) have pointed out that the current set of internationally utilized test methods capture only some of the potential adverse effects associated with exposures to these agents over the lifetime. OBJECTIVES: In this paper, we propose the adaption of the carcinogenicity bioassay to integrate additional protocols for comprehensive long-term toxicity assessment that includes developmental exposures and long-term outcomes, capable of generating information on a broad spectrum of different end points. DISCUSSION: An integrated study design based on a stepwise process is described that includes the priority end points of the Economic Co-operation and Development and the National Toxicology Program guidelines on carcinogenicity and chronic toxicity and developmental and reproductive toxicity. Integrating a comprehensive set of relevant toxicological end points in a single protocol represents an opportunity to optimize animal use in accordance with the 3Rs (replacement, reduction and refinement). This strategy has the potential to provide sufficient data on multiple windows of susceptibility of specific interest for risk assessments and public health decision-making by including prenatal, lactational, neonatal exposures and evaluating outcomes over the lifespan. CONCLUSION: This integrated study design is efficient in that the same generational cohort of rats used for evaluating long-term outcomes can be monitored in satellite parallel experiments to measure biomarkers and other parameters related to system-specific responses including metabolic alterations and endocrine disturbances. Citation: Manservisi F, Babot Marquillas C, Buscaroli A, Huff J, Lauriola M, Mandrioli D, Manservigi M, Panzacchi S, Silbergeld EK, Belpoggi F. 2017. An integrated experimental design for the assessment of multiple toxicological end points in rat bioassays. Environ Health Perspect 125:289-295; http://dx.doi.org/10.1289/EHP419.

Synergism between sinusoidal-50 Hz magnetic field and formaldehyde in triggering carcinogenic effects in male Sprague-Dawley rats.

BACKGROUND: Experimental rodent bioassays performed up to now have failed to provide conclusive confirmation of the carcinogenicity of extremely low frequency magnetic fields (ELFMF). OBJECTIVES: To evaluate the potential synergistic carcinogenic effects of concurrent exposure to ELFMF and formaldehyde in four groups of male and female Sprague-Dawley rats. METHODS: One group was exposed from prenatal life until natural death to S-50 Hz MF and to formaldehyde in drinking water from 6 weeks of age for 104 weeks, two groups were treated only with formaldehyde or only with MF and one group served as untreated control. RESULTS: Compared to untreated controls, exposure to MF and formaldehyde causes in males a statistically significant increased incidence of malignant tumors (P ≤ 0.01), thyroid C-cell carcinomas (P ≤ 0.01), and hemolymphoreticular neoplasias (P ≤ 0.05). No statistically significant differences were observed among female groups. CONCLUSIONS: Life-span exposure to MF and formaldehyde induces statistically significant carcinogenic effects in male rats. Am. J. Ind. Med. 59:509-521, 2016. © 2016 Wiley Periodicals, Inc.

Life-span exposure to sinusoidal-50 Hz magnetic field and acute low-dose γ radiation induce carcinogenic effects in Sprague-Dawley rats.

Background In 2002 the International Agency for Research on Cancer classified extremely low frequency magnetic fields (ELFMF) as a possible carcinogen on the basis of epidemiological evidence. Experimental bioassays on rats and mice performed up to now on ELFMF alone or in association with known carcinogens have failed to provide conclusive confirmation. Objectives To study the carcinogenic effects of combined exposure to sinusoidal-50 Hz (S-50 Hz) magnetic fields and acute γ radiation in Sprague-Dawley rats. Methods We studied groups of male and female Sprague-Dawley rats exposed from prenatal life until natural death to 20 or 1000 µT S-50 Hz MF and also to 0.1 Gy γ radiation delivered as a single acute exposure at 6 weeks of age. Results The results of the study showed significant carcinogenic effects for the mammary gland in males and females and a significant increased incidence of malignant schwannomas of the heart as well as increased incidence of lymphomas/leukemias in males. Conclusions These results call for a re-evaluation of the safety of non-ionizing radiation.

Life-span carcinogenicity studies on Sprague-Dawley rats exposed to γ-radiation: design of the project and report on the tumor occurrence after post-natal radiation exposure (6 weeks of age) delivered in a single acute exposure.

BACKGROUND: Experimental long-term carcinogenicity bioassays conducted on rats and mice proved that ionizing radiation can induce a variety of tumor types. However few studies have been conducted on rats. METHODS: This report deals with the effects of γ-radiation in groups of 416-1,051 6-weeks old Sprague-Dawley rats exposed to 0, 0.1, 1, or 3 Gy of γ-radiation delivered in a single acute exposure. The experiment lasted for the animals' lifespan and all were necropsied and underwent full histopathological evaluation. RESULTS: The results confirm the dose-related carcinogenic effects of γ-radiation for several organs and tissues. Moreover they indicate that exposure to 0.1 Gy induces a statistically significant increased incidence in Zymbal gland carcinomas and pancreas islet cell carcinomas in females. CONCLUSIONS: Our data show that exposure to γ-radiation induces carcinogenic effects at all tested doses.

Intranasal immunization in mice with non-ionic surfactants vesicles containing HSV immunogens: a preliminary study as possible vaccine against genital herpes.

The purpose of this study was to investigate the potential of intranasal immunization with non-ionic surfactant vesicles (NISV) containing either the secretory recombinant form of glycoprotein B (gBs) of herpes simplex virus type 1 or a related polylysine reach peptides (DTK) for induction of protective immunity against genital herpes infection in mice. NISV were prepared by lipid film hydration method. The mean diameter of vesicles was around 390 nm for DTK-containing NISV (DTK-NISV) and 320 nm for gB1s-containing NISV (gB1s-NISV). The encapsulation efficiency of the molecules was comprised between 57% and 70%. After 7-14 day NISV maintained stable dimensions and a drug encapsulation higher than 48%. We showed that intranasal immunization with gB1s-NISV induces gB-specific IgG antibody and lymphoproliferative responses, whereas vaccination with DTK-NISV was not able to generate a gB-specific immune response. Our results indicate that vaccination of BALB/c mice with gB1s-NISV induced Th1 responses, as characterized by increased titre of IG2a in plasma and IFN-production in CD4+ splenic cells. Intranasal immunization with gB1s-NISV could elicit 90% (almost complete) protection against a heterologous lethal vaginal challenge with herpes simplex virus type 2. These data may have implications for the development of a mucosal vaccine against genital herpes.

Aspartame administered in feed, beginning prenatally through life span, induces cancers of the liver and lung in male Swiss mice.

BACKGROUND: Aspartame (APM) is a well-known intense artificial sweetener used in more than 6,000 products. Among the major users of aspartame are children and women of childbearing age. In previous lifespan experiments conducted on Sprague-Dawley rats we have shown that APM is a carcinogenic agent in multiple sites and that its effects are increased when exposure starts from prenatal life. OBJECTIVE: The aim of this study is to evaluate the potential of APM to induce carcinogenic effects in mice. METHODS: Six groups of 62-122 male and female Swiss mice were treated with APM in feed at doses of 32,000, 16,000, 8,000, 2,000, or 0 ppm from prenatal life (12 days of gestation) until death. At death each animal underwent complete necropsy and all tissues and organs of all animals in the experiment were microscopically examined. RESULTS: APM in our experimental conditions induces in males a significant dose-related increased incidence of hepatocellular carcinomas (P < 0.01), and a significant increase at the dose levels of 32,000 ppm (P < 0.01) and 16,000 ppm (P < 0.05). Moreover, the results show a significant dose-related increased incidence of alveolar/bronchiolar carcinomas in males (P < 0.05), and a significant increase at 32,000 ppm (P < 0.05). CONCLUSIONS: The results of the present study confirm that APM is a carcinogenic agent in multiple sites in rodents, and that this effect is induced in two species, rats (males and females) and mice (males). No carcinogenic effects were observed in female mice. Am. J. Ind. Med. 53:1197-1206, 2010. © 2010 Wiley-Liss, Inc.

Eudragit microparticles as a possible tool for ophthalmic administration of acyclovir.

This paper describes the production and characterization of polyacrylic polymer (Eudragit RL, RS and NE) microparticles by spray drying method. Microparticles were designed for ophthalmic administration of acyclovir. Microparticle morphology was characterized by optical and electron microscopy. The release kinetics of the drug from microspheres were determined by a dialysis method. The spray drying method described allows the production of microparticles with acceptable encapsulation efficiency and appropriate dimensional characteristics for ophthalmic administration. Release profile data indicate that acyclovir is released from microparticles in a controlled manner. In addition the release pattern of the drug is influenced by the type of Eudragit used for microparticle production. Moreover the plaque reduction efficiency of acyclovir containing microparticles (except for RS/NE microspheres) is comparable to that displayed by the free drug. Finally our results suggest that acyclovir containing microparticles could represent an interesting system for the release of this antiviral drug at the eye site.

Stem cells and nervous tissue repair: from in vitro to in vivo.

Recent development in stem cell biology has indicated a new possible approach for the treatment of neurological diseases. However, in spite of tremendous hope generated, we are still on the way to understand if the use of stem cells to repair mature brain and spinal cord is a reliable possibility. In particular, we know very little on the in situ regulation of adult neural stem, and this also negatively impact on cell transplant possibilities. In this chapter we will discuss issues concerning the role and function of stem cells in neurological diseases, with regard to the impact of features of degenerating neurons and glial cells on in situ stem cells. Stem cell location and biology in the adult brain, brain host reaction to transplantation, neural stem cell reaction to experimental injuries and possibilities for exogenous regulation are the main topics discussed.