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Regulatory Toxicology and Pharmacology: RTP

Sara Najimi, Mojtaba Shakibaie, Elham Jafari, Atefeh Ameri, Nazanin Rahimi, Hamid Forootanfar, Mahnaz Yazdanpanah, Hamid Reza Rahimi
The current study was performed to evaluate the acute and subacute toxicities of biogenic tellurium nanorods (Te NRs). The Te NRs were prepared using Pseudomonas pseudoalcaligenes strain Te in a culture medium containing K2TeO3 (1 mM) and their physiochemical properties were investigated using TEM, EDX and XRD. The median lethal dose (LD50) of Te NRs and potassium tellurite (K2TeO3) were determined in mice and the subacute toxicity was also evaluated. The experimental design involved certain general toxicological, haematological, serum and histopathological investigations...
September 15, 2017: Regulatory Toxicology and Pharmacology: RTP
Katy Taylor, David J Andrew
A previous retrospective analysis of substances in the ECHA CHEM database concluded that, for industrial chemicals with a 'low (sub)acute toxicity profile', further testing in the 90-day study is unlikely to change this profile (Taylor et al., 2014). We have further tested this hypothesis by assessing the outcome of substances with testing proposals for which a prediction was made in that paper that the NOAEL based on the 90-day study would be 1000 mg/kg bw/d. Indeed, for seven out of ten substances for which data was available, the profile was shown to be held...
September 15, 2017: Regulatory Toxicology and Pharmacology: RTP
Yoshimi Niwano, Kazunori Konno, Takeshi Matayoshi, Keisuke Nakamura, Taro Kanno, Keiichi Sasaki
We conducted an oral mucosal irritation study in hamsters to evaluate a therapeutic apparatus using hydrogen peroxide (H2O2) photolysis for periodontitis treatment (ISO 10993-Part 10, Annex B.3). The cheek pouches in 15 male hamsters were allocated to one of six groups. Group 1 received pure water treatment (control group). Group 2 received laser irradiation at 80 mW. Group 3 received 3% H2O2. Groups 4-6 received laser irradiation of 3% H2O2 at 80, 40, and 20 mW, respectively. The total treatment time was set at 7 min and treatment was repeated three times at approximately 1-h intervals...
September 14, 2017: Regulatory Toxicology and Pharmacology: RTP
Melissa J Vincent, Ann Parker, Andrew Maier
Research indicates a correlative relationship between asthma and use of consumer cleaning products. We conduct a systematic review of epidemiological literature on persons who use or are exposed to cleaning products, both in occupational and domestic settings, and risk of asthma or asthma-like symptoms to improve understanding of the causal relationship between exposure and asthma. A scoring method for assessing study reliability is presented. Although research indicates an association between asthma and the use of cleaning products, no study robustly investigates exposure to cleaning products or ingredients along with asthma risk...
September 13, 2017: Regulatory Toxicology and Pharmacology: RTP
Kristie M Sullivan, Manoj Aggarwal, Jonathan M Akins, Eric Fabian, Jon R Heylings, Hans Raabe, P V Shah, Christiane Wiemann, Richard Peffer
Although an internationally-adopted in vitro dermal absorption test guideline is available (OECD Test Guideline 428), the replacement of the in vivo approach in North America for pesticide formulations has not occurred due to concern over the reliability and consistency of the in vitro results. A 2012 workshop convened a panel of experts in the conduct of in vitro studies used for pesticide risk assessment, together with North American regulators, to examine techniques for in vitro dermal absorption testing...
September 12, 2017: Regulatory Toxicology and Pharmacology: RTP
Susan P Felter, Andrew N Carr, Tingting Zhu, Taryn Kirsch, Gloria Niu
Diaper rash can adversely impact the barrier properties of skin, with potential implications for increased absorption of chemicals through the skin, and this should be accounted for in any exposure assessment used in the safety evaluation of consumer products used in the diaper ("nappy") area. In the absence of a quantitative evaluation of the potential impact of diaper rash, a default assumption of 100% dermal penetration is often made for substances applied in the diaper area. We consider here the extent, duration and severity of diaper rash and make a recommendation for conservative assumptions to incorporate into exposure assessments...
September 12, 2017: Regulatory Toxicology and Pharmacology: RTP
Gunnar Damgaard Nielsen, Peder Wolkoff
Sensory irritation of eyes and upper airways is an important endpoint for setting occupational exposure limits (OELs) and indoor air guidelines. Sensory irritants cause a painful burning, stinging and itching sensation. Controlled chamber studies are the "golden standard" for evaluations. Well conducted workplace studies offer another possibility. For generalization, the number of participants and their age, smoking, gender, and prior exposure, experience and mood has to be considered. Exposure assessments have to be reliable and exposure duration sufficiently long to establish time-response relationships...
September 11, 2017: Regulatory Toxicology and Pharmacology: RTP
Bhanuramya Mangalampalli, Naresh Dumala, Paramjit Grover
Advancements in nanotechnology have led to the development of the nanomedicine, which involves nanodevices for diagnostic and therapeutic purposes. A key requirement for the successful use of the nanoparticles (NPs) in biomedical applications is their good dispensability, colloidal stability in biological media, internalization efficiency, and low toxicity. Therefore, toxicological profiling is necessary to understand the mechanism of NPs and microparticles (MPs). MgO NPs have attracted wide scientific interest due to ease of synthesis, chemical stability and unique properties...
September 9, 2017: Regulatory Toxicology and Pharmacology: RTP
Assis Ecker, Carla Giane Loss, Stephen A Adefegha, Aline Augusti Boligon, Silvane Souza Roman
Maytenus ilicifolia Mart. ex Reissek is a plant commonly used in folklore medicine in the management of gastric diseases in South America. This study explores the effects of a supratherapeutic dose of aqueous and ethanol extracts of M. ilicifolia (1360 mg/kg) on fertility and neurobehavioral status in male and pregnant rats. A battery of sensory-motor developmental endpoints was carried out to assess impairments on pups of dams orally treated with the aqueous extract of M. ilicifolia during the organogenesis period of pregnancy (GD 9 through GD 14)...
September 7, 2017: Regulatory Toxicology and Pharmacology: RTP
Caroline Hall, Ian Grayson
MYOLUTION(®), which consists of a mixture of the branched chain keto acids, keto-leucine, keto-isoleucine and keto-valine, as their calcium salts, may potentially be used as a food ingredient based on the reported contributions of these compounds to muscle health and exercise performance. Tests on genotoxicity and sub-chronic toxicity were performed to evaluate the safety of branched chain keto acids. No genotoxic effects were observed in the bacterial mutation assay or the in vitro micronucleus assay in human lymphocytes...
September 6, 2017: Regulatory Toxicology and Pharmacology: RTP
Zhiwei Liu, Amanda Wasniewski, Sara Lamperti, Katia Mainolfi, Appavu Chandrasekaran
For agrochemicals tested in a carcinogenicity rodent study, it is often not possible to use the same high dose to achieve maximum tolerated dose (MTDs) without overdosing or insufficiently challenging one gender if significant gender differences are known. Toxicokinetic (TK) data for pesticide FR from a 28-day rat study showed that males required a 3-fold higher external dose compared to females to produce similar internal exposure levels of the parent compound. In the 90-day study, 8%/17% (M/F) decrease in bodyweight gain (BWG) and 15%/15% (M/F) increase in relative liver weights were observed in the 6000 ppm males and 2000 ppm females, respectively...
September 6, 2017: Regulatory Toxicology and Pharmacology: RTP
Mineo Matsumoto, Shin-Ichi Komatsu, Takanori Ikeda, Kazuhiro Shimomura, Kazuto Watanabe, Keiji Hirabayadi, Jun-Ichi Sawada, Kazushige Maki, Kazutoshi Shinoda, Osamu Fueki, Hiroshi Onodera
In an attempt to understand the unique toxicity of adjuvanted vaccines, we studied how toxicity develops over time following vaccine administration. In addition to on- and off-target toxicity typically observed with general pharmaceuticals, we observed toxicity associated with both the generation and the broad action of effectors (antibodies and/or cytotoxic T lymphocytes, CTLs). The impact on effector generation appears to be related to local tolerance specific to the adjuvant. The vaccine immune response by effectors serves to demonstrate species relevance as outlined in the recent WHO guideline on the nonclinical evaluation of adjuvanted vaccines...
September 6, 2017: Regulatory Toxicology and Pharmacology: RTP
Haleh Saber, Pedro Del Valle, Tiffany K Ricks, John K Leighton
We retrospectively examined the nonclinical studies conducted with 17 CD3 bispecific constructs in support of first-in-human (FIH) trials in oncology. We also collected information on the design of dose-finding clinical trials. Sponsors have used different MABEL approaches for FIH dose selection. To better assess acceptable approaches, FIH doses were computed from nonclinical studies and compared to the maximum tolerated doses (MTDs) in patients, to the highest human doses (HHDs) when an MTD was not identified, or to the recommended human dose (RHD) for blinatumomab...
September 5, 2017: Regulatory Toxicology and Pharmacology: RTP
Ian Kimber
Bisphenol A (BPA) is used in the manufacture of polycarbonate and epoxy resin plastics. There has been interest in the possibility that BPA has immunotoxic properties, and a variety of investigations have explored this. Among the approaches taken have been human observational and cross-sectional studies, investigations using experimental animals, and in vitro studies, some of which have been reviewed previously by the European Food Safety Authority (EFSA). This commentary aims to provide a focused review of data regarding the ability of BPA to perturb the immune system, including the developing immune system, and to cause related adverse health effects...
September 1, 2017: Regulatory Toxicology and Pharmacology: RTP
Alicia Paini, Jeremy A Leonard, Tomas Kliment, Yu-Mei Tan, Andrew Worth
Physiologically based kinetic (PBK) models are used widely throughout a number of working sectors, including academia and industry, to provide insight into the dosimetry related to observed adverse health effects in humans and other species. Use of these models has increased over the last several decades, especially in conjunction with emerging alternative methods to animal testing, such as in vitro studies and data-driven in silico quantitative-structure-activity-relationship (QSAR) predictions. Experimental information derived from these new approach methods can be used as input for model parameters and allows for increased confidence in models for chemicals that did not have in vivo data for model calibration...
September 1, 2017: Regulatory Toxicology and Pharmacology: RTP
Yi-Mei Wang, Zhou Yu, Zeng-Ming Zhao, Li Jia, Hai-Qin Fang, Ting-Fen Zhang, Xiao-Yan Yuan, Yu-Lei Shu, Jun He, Hui Peng, Li-Zhong Li, Jun Zhao, Xu-Dong Jia, Shuang-Qing Peng
Concerns regarding the adverse effects of long-term exposure to low levels of rare earth elements (REEs) from foods on human health have arisen in recent years. Nevertheless, no official acceptable daily intake (ADI) has yet been proposed for either total REEs or individual REE. In accordance with the Organization for Economic Co-operation and Development (OECD) testing guideline, the present study was undertaken to evaluate the subchronic toxicity of yttrium, a representative heavy REE with higher contaminated level in foods in China, to achieve a no observed adverse effect level (NOAEL) which is a critical basis for the establishment of an ADI...
September 1, 2017: Regulatory Toxicology and Pharmacology: RTP
Melissa J Vincent, Jonathan A Bernstein, David Basketter, Judy S LaKind, G Scott Dotson, Andrew Maier
Uncertainties in understanding all potential modes-of-action for asthma induction and elicitation hinders design of hazard characterization and risk assessment methods that adequately screen and protect against hazardous chemical exposures. To address this challenge and identify current research needs, the University of Cincinnati and the American Cleaning Institute hosted a webinar series to discuss the current state-of-science regarding chemical-induced asthma. The general consensus is that the available database, comprised of data collected from routine clinical and validated toxicological tests, is inadequate for predicting or determining causal relationships between exposures and asthma induction for most allergens...
September 1, 2017: Regulatory Toxicology and Pharmacology: RTP
Richard A Becker, David A Dreier, Mary K Manibusan, Louis A Tony Cox, Ted W Simon, James S Bus
IARC has begun using ToxCast/Tox21 data in efforts to represent key characteristics of carcinogens to organize and weigh mechanistic evidence in cancer hazard determinations; and this implicit inference approach also is being considered by USEPA. To determine how well ToxCast/Tox21 data can explicitly predict cancer hazard, this approach was evaluated with statistical analyses and machine learning prediction algorithms. Substances USEPA previously classified as having cancer hazard potential were designated as positives and substances not posing a carcinogenic hazard were designated as negatives...
August 30, 2017: Regulatory Toxicology and Pharmacology: RTP
Blanca Arguello, Teresa M Salgado, Gert Laekeman, Fernando Fernandez-Llimos
The aim of this study was to create a standard set of essential drug information items as a tool to assess the completeness of any type of drug information source, regardless of its length, using a Delphi consensus panel of European health care professionals. A compilation of drug-related information items was performed by searching several resources for health care professionals and a final list of 162 items was obtained. Fifty-seven experts in drug information from 23 different European countries were invited to participate in a three-round Delphi technique to obtain consensus on items considered essential and non-essential content of information...
August 26, 2017: Regulatory Toxicology and Pharmacology: RTP
Mikaela P Pinz, Angélica S Reis, Renata Leivas de Oliveira, Guilherme T Voss, Ane G Vogt, Manoela do Sacramento, Juliano A Roehrs, Diego Alves, Cristiane Luchese, Ethel A Wilhelm
The present study was designed to examine the antinociceptive and anti-inflammatory effects of 7-chloro-4-phenylsulfonyl quinoline (PSOQ). Mice were orally (p.o) pretreated with PSOQ (0.01-10 mg/kg), meloxicam (10 mg/kg), 30 min prior to the acetic acid, hot-plate and open field tests. PSOQ reduced abdominal writhing induced by acetic acid, while meloxicam presented no effect. The latency time in the hot-plate test and locomotor/exploratory activities in the open field test were not altered by treatments...
August 23, 2017: Regulatory Toxicology and Pharmacology: RTP
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