scholarly journals Urolithiasis in children and exposure to melamine: A review of the epidemiological literature

2019 ◽  
Vol 3 ◽  
pp. 239784731986160
Author(s):  
Gerard MH Swaen
Keyword(s):  
Extensive Literature ◽  
Production Volume ◽  
Powdered Milk ◽  
High Production Volume ◽  
Epidemiological Database ◽  
Epidemiology Data ◽  
Adverse Effect Level ◽  
Data Points ◽  
Effect Level ◽  
Epidemiology Studies

Melamine (ME) is a high production volume compound, mainly used for the synthesis of ME-formaldehyde resins. There is an extensive toxicological and epidemiological database on this compound, but the epidemiology has so far not been reviewed. An extensive literature search in PubMed was conducted and relevant ME epidemiology studies were identified and assessed. The epidemiology data nearly entirely consisted of studies on the health effects due to the food tampering catastrophe in China discovered in 2008 where ME was intentionally added to powdered milk products. Most of these studies were aimed at assessing the extent of the catastrophe and the clinical follow-up of affected children. A reliable dose–response relationship could not be derived from the epidemiology studies. However, they do contain several strong data points that can assist in ranging the No Observed Adverse Effect Level (NOAEL) for humans, for children in particular.

scholarly journals Palmitoylethanolamide: Prenatal Developmental Toxicity Study in Rats

2021 ◽  
pp. 109158182098607
Author(s):  
Narendra S. Deshmukh ◽  
Shailesh Gumaste ◽  
Silma Subah ◽  
Nathasha Omal Bogoda
Keyword(s):  
Body Weight ◽  
Developmental Toxicity ◽  
Reproductive Toxicity ◽  
Toxicity Study ◽  
High Dose ◽  
Pregnant Rats ◽  
Human Dose ◽  
Adverse Effect Level ◽  
Female Wistar Rats ◽  
Effect Level

Palmitoylethanolamide (PEA) is an endogenous ethanolamine playing a protective and homeodynamic role in animals and plants. Prenatal developmental toxicity of PEA was tested following oral administration to pregnant female Wistar rats, from days 0 to 19 of gestation, at dosage of 250, 500, or 1,000 mg/kg body weight, according to Organisation for Economic Co-operation and Development Test Guideline No. 414. On gestation day 20, cesarean sections were performed on the dams, followed by examination of their ovaries and uterine contents. The fetuses were further examined for external, visceral, and skeletal abnormalities. Palmitoylethanolamide did not cause any alterations at any of the given dosages in the measured maternal parameters of systemic toxicity (body weight, food consumption, survival, thyroid functions, organ weight, histopathology), reproductive toxicity (preimplantation and postimplantation losses, uterus weight, number of live/dead implants and early/late resorptions, litter size and weights, number of fetuses, their sex ratio), and fetal external, visceral, or skeletal observations. Any alterations that were recorded were “normal variations” or “minor anomalies,” which were unrelated to treatment with PEA. Under the condition of this prenatal study, the no-observed-adverse-effect level of PEA for maternal toxicity, embryotoxicity, fetotoxicity, and teratogenicity in rats was found to be >1,000 mg/kg body weight/d. It indicates that PEA is well tolerated by and is safe to pregnant rats even at a high dose of 1,000 mg/kg body weight/d, equivalent to a human dose of greater than 9.7 g/d. This prenatal developmental toxicity study contributes greatly in building a robust safety profile for PEA.

scholarly journals Estimating the Impact of High-Production-Volume Chemicals on Remote Ecosystems by Toxic Pressure Calculation

2006 ◽  
Vol 40 (5) ◽  
pp. 1573-1580 ◽  
Author(s):  
Jasper V. Harbers ◽  
Mark A. J. Huijbregts ◽  
Leo Posthuma ◽  
Dik van de Meent
Keyword(s):  
Production Volume ◽  
High Production Volume ◽  
Pressure Calculation ◽  
High Production ◽  
The Impact

Ototoxicity of trichloroethylene in concentrations relevant for the working environment

2008 ◽  
Vol 27 (3) ◽  
pp. 195-200 ◽  
Author(s):  
A Vyskocil ◽  
T Leroux ◽  
G Truchon ◽  
F Lemay ◽  
F Gagnon ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Convincing Evidence ◽  
Working Environment ◽  
Exposure Limits ◽  
Additive Interaction ◽  
Animal Data ◽  
Short Term Exposure ◽  
Adverse Effect Level ◽  
Effect Level ◽  
Permissible Exposure Limits

Organic solvents can cause hearing loss themselves or promote noise-induced hearing loss. The objective of this study was to review the literature on the effects of low-level exposure to trichloroethylene on the auditory system and consider its relevance for the occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the Quebec permissible exposure limits: 50 ppm 8-h time-weighed average exposure value (TWAEV) and 200 ppm short-term exposure value (STEV). In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at the STEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. There is no convincing evidence of trichloroethylene-induced hearing losses in workers. In rats, trichloroethylene affects the auditory function mainly in the cochlear mid- to high-frequency range with a lowest observed adverse effect level (LOAEL) of 2000 ppm. No studies on ototoxic interaction after combined exposure to noise and trichloroethylene were identified in humans. In rats, supra-additive interaction was reported. Further studies with sufficient data on the trichloroethylene exposure of workers are necessary to make a definitive conclusion. In the interim, we recommend considering trichloroethylene as an ototoxic agent.

scholarly journals Determination of the Factors Controlling Crystallography Non-Conformance in Single Crystal Turbine Blade Production on an Industrial Scale

2007 ◽  
Vol 558-559 ◽  
pp. 695-700
Author(s):  
J. Cameron ◽  
P.W. Shelton
Keyword(s):  
Single Crystal ◽  
Physical And Mechanical Properties ◽  
Structure Design ◽  
Grain Structure ◽  
Industrial Scale ◽  
Optimum Process ◽  
Production Volume ◽  
Single Crystal Turbine Blade ◽  
High Production Volume ◽  
Input Variables

The arduous conditions to which hot section turbine components are subjected in service, dictate the superior physical and mechanical properties demanded of them. The demand for both high temperature and creep resistance, and anisotropic property requirements of the components has lead to developments in alloy composition, component geometry and single, oriented grain structure design. The slim tolerances and high quality standards imposed on such design features, combined with the high production volume in industry means that component non-conformances to the customer specifications occur. The input variables contributing to crystallography non-conformance in single crystal production have been investigated with a view to defining optimum process parameters for the successful manufacture of single crystal investment cast components on an industrial scale.

scholarly journals Animal Use and Lessons Learned in the U.S. High Production Volume Chemicals Challenge Program

2012 ◽  
Vol 120 (12) ◽  
pp. 1631-1639 ◽  
Author(s):  
Patricia L. Bishop ◽  
Joseph R. Manuppello ◽  
Catherine E. Willett ◽  
Jessica T. Sandler
Keyword(s):  
Lessons Learned ◽  
Production Volume ◽  
High Production Volume ◽  
Animal Use ◽  
High Production ◽  
The U.S

Field Assisted Sintering Technology (FAST) Model for Prediction of Final Properties

2010 ◽  
Author(s):  
Rajiv Paul ◽  
Anil K. Kulkarni ◽  
Jogender Singh
Keyword(s):  
Electrical Breakdown ◽  
Extensive Literature ◽  
Heating Rates ◽  
Predictive Tool ◽  
Simultaneous Application ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Data Points ◽  
Field Assisted Sintering ◽  
The Relationship

Sintering is the process of making materials from powder form by heating the powder below its melting point until the particles fuse to each other. Field assisted sintering technology (FAST), also sometimes known as spark plasma sintering (SPS), uses a pulsed and/or continuous electric current along with the simultaneous application of compressive pressure which leads to extremely high heating rates and short processing durations. A high relative density and small grain size promote superior properties such as greater hardness and electrical breakdown. Hence, selection of the proper sintering parameters is of paramount importance and a predictive model would be extremely useful in narrowing the range of experimental parameters. This will drastically reduce the number of extra attempts at obtaining certain properties in a material and save experimentation time, effort and material to name a few. Four of the most important FAST parameters: target temperature, holding time, heating rate and initial particle size, have been reviewed to assess their effect on the densification, hardening and grain growth of Alumina, Copper, Silicon Carbide, Tungsten and Tungsten Carbide through extensive literature survey. The relationship between each has been incorporated in a Microsoft Excel program which acts as a predictive tool to determine an estimate of the final properties based on the initial parameters chosen. This is done by curve fitting a polynomial onto the existing data points as closely as possible and using the polynomial to obtain final properties as a function of the initial parameters. The model was verified against an existing paper which sought to obtain the optimum sintering parameters for Copper. While the actual experimentation range was 400°C to 800°C, the program would have suggested a much narrower range from 650°C to 800°C and hence saved unnecessary additional efforts.

Safety of a novel galacto-oligosaccharide: Genotoxicity and repeated oral dose studies

2009 ◽  
Vol 28 (10) ◽  
pp. 619-630 ◽  
Author(s):  
T. Kobayashi ◽  
N. Yasutake ◽  
K. Uchida ◽  
W. Ohyama ◽  
K. Kaneko ◽  
...  
Keyword(s):  
Oral Dose ◽  
Kluyveromyces Lactis ◽  
Clinical Signs ◽  
Chinese Hamster ◽  
Metabolic Activation ◽  
Blood Chemistry ◽  
Control Group ◽  
Sprague Dawley ◽  
Adverse Effect Level ◽  
Effect Level

A series of safety tests were undertaken on a novel galacto-oligosaccharide (GOS) produced from lactose by a two-step enzymatic process involving Sporobolomyces singularis and Kluyveromyces lactis. Bacterial reverse mutation and chromosomal aberration tests, with or without metabolic activation, were performed. These tests showed no mutagenesis in the Ames assay or in Escherichia coli WP2uvrA, and no chromosomal aberrations in cultured fibroblast cells from Chinese hamster lungs (CHL/IU). Micronuclei were not induced in the reticulocytes of mouse peripheral blood following oral administration of GOS. In a 90-day repeated oral dose toxicity study in rats, GOS was administered at 0, 500, 1000 and 2000 mg/kg to male and female Sprague-Dawley rats. There were no GOS-related changes in clinical signs, body weight, water intake, feed intake, urinalysis, ophthalmology, haematology, blood chemistry, organ weights, gross pathology or histopathology in any of the treatment groups compared to the control group. The no observed adverse effect level (NOAEL) of GOS was at least 2000 mg/kg/day in both males and females.

The High Production Volume Challenge Program

2006 ◽  
pp. 1-19
Author(s):  
Richard Hefter ◽  
Barbara Leczynski ◽  
Charles Auer
Keyword(s):  
Production Volume ◽  
High Production Volume ◽  
High Production ◽  
Volume Challenge
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