bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhalation Toxicity Study of Methanol, Toluene, and Methanol/Toluene Mixtures in Rats: Effects of 28-Day Exposure
Authors: Poon Raymond , Chu Ih , Bjarnason Stephen , Potvin Marc , Vincent Renaud , Miller Richard B. , Valli Victor E.
Published: September 2013

The inhalation toxicity of methanol and toluene was investigated in rats. Young Sprague Dawley rats of both sexes were exposed to vapors of methanol (300 ppm, 3000 ppm), toluene (30 ppm, 300 ppm) or methanol/toluene (300/30 ppm, 300/300 ppm, 3000/30 ppm, and 3000/300 ppm) six hrs per day, five days/week for four weeks. Control animals inhaled air only. Increased serum alkaline phosphatase activity was observed in males exposed to high-dose toluene, and decreased creatinine was noted in the group exposed to high-dose methanol/toluene. The thyroid gland in females appeared to be a target organ for inhaled methanol, toluene, and methanol/toluene, although the changes were confined to a mild, and occasionally moderate, reduction in follicle size. Histopathological changes of the nasal passages, consisting of subepithelial nonsuppurative inflammation, occurred in higher incidences in rats exposed to methanol/toluene than in those exposed to the individual vapors. Inhalation of methanol, toluene, or methanol/toluene produced no changes in liver weights, hepatic mixed-function oxidases, or serum aspartate transaminase activities, and onlly minimal changes in liver histopathology. The only liver changes were decreased liver weight and increased cytoplasmic density of the periportal areas in females exposed to high-dose methanol/toluene. These data indicated that exposure to methanol, toluene, or a mixture of both produced mild biochemical effects and histological changes in the thyroid and nasal passage. No apparent interactive effects were observed.
Trichloroethylene — a Review of the Literature From a Health Effects Perspective
Authors: Gist Ginger L. , Burg Je Anne R.
Published: September 2013

This report reviews the literature on the impact of exposure to trichloroethylene (TCE) on human health. Special emphasis is given to the health effects reported in excess of national norms by participants in the TCE Subregistry of the Volatile Organic Compounds Registry of the National Exposure Registries — persons with documented exposure to TCE through drinking and use of contaminated water. The health effects reported in excess by some or all of the sex and age groups studied were speech and hearing impairments, effects of stroke, liver problems, anemia and other blood disorders, diabetes, kidney disease, urinary tract disorders, and skin rashes.
Changes in Lung Permeability Correlate With Lung Histology in a Chronic Exposure Model
Authors: Hays Allison M. , Parliman Grace , Pfaff John K. , Lantz R.C. , Tinajero Julieta , Tollinger Brian , Hall Jack N. , Witten Mark L.
Published: September 2013

In a simulated military flight-line exposure protocol, the effects of JP-8 jet fuel exposure on lung epithelial permeability were evaluated in male Fischer 344 rats (F344). Exposures were nose-only and for one hour daily. Groups were exposed for 7, 28, and 56 days. A protocol for administering a low dose (500mg/m3/hr) and a high dose (813-1094mg/m 3 /hr) of JP-8 jet fuel was used. Longitudinal sham-exposure groups (no jet fuel) for 7, 28, and 56 days were included in the protocol. Lung epithelial permeability was measured by clearance of technetium-labeled diethylenetriamine pentaacetate (99mTcDTPA, molecular weight = 492 daltons, physical half-life = 6.02 hours). The percent clearance of 99mTcDTPA per minute was calculated. Alveolar epithelial clearance for JP-8-exposed rats was dependent on both exposure concentration and duration. It was noted that at low-dose exposure concentrations alveolar epithelial clearance of 99mTcDTPA returned to low levels (LD56 = 1.09% per min; LC56 = 0.98% per min), suggesting recovery as evidenced by microscopic exam. The corresponding 56-day high-dose group (n = 10) had a significantly higher (p < 0.05) value of 2.25% per minute. The 28-day low-dose (n = 15) and high-dose (n = 20) groups had clearance values that were significantly increased from their longitudinal control group (n = 17). The alveolar epithelial permeability values were 2.51, 1.95, and 1.20, respectively. The seven-day longitudinal control, low-dose, and high-dose groups had alveolar permeability values of 1.57, 2.16, and 2.07, respectively. The lung histology correlated
Evaluation of Granulation Peripheral Blood Basophils in People Exposed To Industrial Contaminants
Authors: Nied Anna , Dabrowski Zbigniew , Bielawka Stanislaw
Published: September 2013

The effect of industrial contaminants on the cytomorphometry of basophils was studied. A statistically significant difference in the densification of cytoplasmic granules of basophils was observed in people exposed to pollutants compared to people from less contaminated areas. No differences in cell area, nucleus area, or cytoplasm size were found among the tested groups.
Short-Term Inhalation Toxicity of Methanol, Gasoline, and Methanol/Gasoline in the Rat
Authors: Poon Raymond , Chu IH , Bjarnason Stephen , Vincent Renaud , Potvin Marc , Miller Richard B. , Valli Victor E.
Published: September 2013

Four- to five-week-old male and female Sprague Dawley rats were exposed to vapors of methanol (2500 ppm), gasoline (3200 ppm), and methanol/gasoline (2500/3200 ppm, 570/3200 ppm) six hours per day, five days per week for four weeks. Control animals were exposed to filtered room air only. Depression in body weight gain and reduced food consumption were observed in male rats, and increased relative liver weight was detected in rats of both sexes exposed to gasoline or methanol/gasoline mixtures. Rats of both sexes exposed to methanol/gasoline mixtures had increased relative kidney weight and females exposed to gasoline and methanol/gasoline mixtures had increased kidney weight. Decreased serum glucose and cholesterol were detected in male rats exposed to gasoline and methanol/gasoline mixtures. Decreased hemoglobin was observed in females inhaling vapors of gasoline and methanol/gasoline at 570/3200 ppm. Urine from rats inhaling gasoline or methanol/gasoline mixtures had up to a fourfold increase in hippuric acid, a biomarker of exposure to the toluene constituent of gasoline, and up to a sixfold elevation in ascorbic acid, a noninvasive biomarker of hepatic response. Hepatic mixed-function oxidase (aniline hydroxylase, aminopyrine N-demethylase and ethoxyresorufin O- deethylase) activities and UDP-glucuronosyltransferase activity were elevated in rats exposed to gasoline and methanol/gasoline mixtures. Histopathologicalchanges were confined to very mild changes in the nasal passages and in the uterus, where decreased incidence or absence of mucosal and myometrial eosinophilia was observed in females inhaling gasoline and methanol/gasoline at 570/3200 ppm. It was concluded that gasoline was largely responsible for the adverse effects, the most significant of which included depression in weight gain in the males, increased liver weight and hepatic microsomal enzyme activities in both sexes, and suppression of uterine eosinophilia. No apparent interactive effects between methanol and gasoline were observed.
Toxicological Investigations in the Semiconductor Industry: IV: Studies On the Subchronic Oral Toxicity and Genotoxicity of Vacuum Pump Oils Contaminated By Waste Products From Aluminum Plasma Etching Processes
Authors: Bauer Siegfried , Wolff Ilona , Werner Nadeshda , Schmidt Reiner , Blume Rudolf , Pelzing Matthias
Published: September 2013

Dry etching processes in semiconductor manufacturing use ionized gases in closed reactors at pressures below 1 torr. Vacuum pump systems that service the reaction chambers are potential sources of exposure to complex mixtures of
Atsdr Evaluation of Health Effects of Chemicals
Authors: Faroon Obaid , Kueberuwa Steven , Smith Lester , Derosa Christopher
Published: September 2013

This document provides public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective of the toxicology of mirex and chlordecone. It contains descriptions and evaluations of toxicological studies and epidemiological investigations and provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health. Additional substances will be profiled in a series of manuscripts to follow.
Polychlorinated Biphenyl (Pcb) and Dichlorodiphenyl Dichloroethylene (Dde) Exposure Among Native American Men From Contaminated Great Lakes Fish and Wildlife
Authors: Fitzgerald Edward F. , Brix Kelley A. , Deres Debra A. , Hwang Syni-An , Bush Brian , Lambert George , Tarbell Alice
Published: September 2013

The New York State Department of Health is performing an investigation of Mohawk men, women, and infants who live at the Akwesasne Reserve along the St. Lawrence River in New York, Ontario, and Quebec. Three large industrial facilities bordering the Akwesasne Reserve have seriously contaminated the soil and the sediments and fish of the adjacent St. Lawrence River with polychlorinated biphenyls (PCBs). The main study goals are to investigate the associations among the consumption of locally caught fish, residential exposure, body burdens of PCBs, and liver enzyme induction. Contamination with PCBs, polychlorinated dibenzofurans, polychlorinated dibenzodioxins, polyaromatic hydrocarbons, dichlorodiphenyl dichloroethylene (DDE) and other chemicals has been documented in locally caught fish, ducks, and other wildlife. The contamination of fish and wildlife is a major concern of the Mohawk people, since their tradition and culture emphasize the interdependence of man and his environment and because many residents formerly depended heavily on local fish and waterfowl for food. The focus of this research from 1986-1992 was on nursing women and infants. The major purpose of the current project is to determine if there are associations between dietary, residential, and occupational exposures to PCBs and DDE and individual body burdens in Mohawk men, specifically the husbands, partners, fathers, brothers, or other male relatives of the women in our other studies. In other fish-eating populations, adult men have tended to demonstrate higher PCB and DDE body burdens than women and children. Exposure estimates based on the reported consumption of locally caught fish and wildlife and residential histories will be correlated with the specific pattern of PCB congeners found in serum, thereby establishing a direct relationship between two potential sources of exposure and body burdens. Liver function will be examined through the caffeine breath test (CBT), a sensitive, noninvasive method of assessment of enzyme induction, one of the earliest detectable biological responses to PCBs in laboratory animals. This test appears promising as a method to detect subtle subclinical effects before the onset of overt clinical symptoms. The project is among the first to explore differences in dietary and other exposures, body burdens, and potential adverse health effects due to specific PCB congeners in men and women from the same source population.
The Great Lakes Information Network: the Region's Internet Information Service
Authors: Ratza Carol A.
Published: September 2013

Communication is the cornerstone of ecosystem protection and sustainable development efforts in the binational Great Lakes region of North America. Great Lakes environmental protection, remediation, and pollution prevention efforts bring together individuals from across the public sector, business and industry, citizens groups, and academia. The region is now working to enhance communications between these groups and the rest of the world, through the Internet-based Great Lakes Information Network (GLIN). Diverse regional data, information, and human resources located at key agencies and organizations are accessible via GLIN. These online resources span environmental quality, human health effects and other research, resource management, transportation, demographic, and economic data, as well as other resources in the Great Lakes region of the United States and Canada. Federal, state, provincial, and regional agencies and a range of citizen, business, and research organizations are cooperating with the lead agency, the Great Lakes Commission, in developing GLIN into the region's shared Internet resource. GLIN resources are accessible to users of ubiquitous Internet research tools including World Wide Web and Gopher. Statistical information on usage and the region's response to ongoing efforts to build the GLIN system and solicit contributions of data and information indicate that we can continue to build GLIN into a truly regional resource which enhances communication among researchers, policy makers, students, and the general public.
Relationship of Hemoglobin To Occupational Exposure To Motor Vehicle Exhaust
Authors: Potula Vijayalakshmi , Hu Howard
Published: September 2013

Objective: To study the relationship of hemoglobin to exposure to motor vehicle exhaust. Design: Survey. Participants: Traffic police, bus drivers, and auto-shop workers (all exposed to auto exhaust in Madras, India) and unexposed office workers. Main Outcome Measures: We measured levels of blood lead (by graphite furnace atomic absorption spectrophotometry), and hemoglobin. Information also was collected on age, employment duration, smoking status, alcohol ingestion, and diet type (vegetarian or nonvegetarian). Results: Increasing exposure to motor vehicle exhaust, as reflected by job category, was significantly associated with lower levels of hemoglobin (p < 0.01). A final multivariate regression model was constructed that began with indicator variables for each job (with office workers as the reference category) and included age, duration of employment, blood lead level, alcohol ingestion, dietary type, and smoking status. After a backward- elimination procedure, employment duration as an auto-shop worker or bus driver remained as significant correlates of lower hemoglobin level and current smoking and long employment duration as significant correlates of higher hemoglobin level. Conclusions: Occupational exposure to automobile exhaust may be a risk factor for decreased hemoglobin level in Madras. This effect appears to be independent of blood lead level and may represent hematopoietic suppression incurred by benzene or accumulated lead burden (which is not well reflected by blood lead levels). Smoking probably increased hemoglobin level through the chronic effects of exposure to carbon monoxide. In this study, a long employment duration may have served as a proxy for better socioeconomic, and therefore, better nutritional status.
An in Vitro Model for Toxicological Investigations of Environmental Neurotoxins in Primary Neuronal Cell Cultures
Authors: Schmuck Gabriele , Schlüter Gerhard
Published: September 2013

Currently, most neurotoxicological investigations are still conducted using various animal models (e.g. chickens, rodents). In this report, alternative strategies of testing were examined to detect the neurotoxic potency of foreign compounds. Primary neuronal cell cultures from fetal rats are already an accepted model for mechanistic and pharmacological studies in drug research. Their suitability for neurotoxicological studies was examined by using industrial model compounds, which are well-known inductors of neuropathies: acrylamide, hexachlorophene, paraquat, n-hexane, and its neurotoxic metabolites acetylaceton and 2,5-hexandione. As a control compound, the nonneurotoxic solvent n-heptane was used. General cytotoxicity and the intracellular content of glial fibrillary acid protein, neuron-specific enolase, and neurofilaments were measured.

n-Heptane induced an acute cytotoxicity and acrylamide and 2,5-hexandione produced a delayed cytotoxicity in primary neuronal cells, whereas the others showed no cytotoxic potency in the tested concentration range. These results were in agreement with the quantification of neurons by neuron-specific enolase. In contrast, with the exception of acetylaceton, glia cells were significantly affected by all neurotoxins at the later time. Signs of axonopathies were demonstrated for acrylamide, n-hexane and its metabolites, as well as for hexachlorophene and paraquat in vitro, by determining the intracellular neurofilament level. Therefore, the determination of cell-specific end points is necessary to detect the neurotoxic potency and quality of a compound, whereas the cytotoxicity assay limited the tested concentration range.
Sperm Chromatin Structure Is Altered in Cynomolgus Monkeys With Environmentally Relevant Blood Lead Levels
Authors: Foster Warren G. , McMahon Avril , Rice Deborah C.
Published: September 2013

Exposure to lead has been associated with a variety of adverse reproductive outcomes such as spontaneous abortion, impaired fecundity, and sterility. Although decreased sperm counts and serum testosterone levels have been found in men with occupational lead exposure, animal experiments suggest that fertility may be impaired at blood lead levels that have no apparent effect on reproductive hormone levels or sperm concentration. Consequently, this study investigated the effect of chronic lead treatment on semen quality in healthy cynomolgus monkeys aged 15- 20 years with mean (± SD) blood lead levels of 10 ± 3 μg/dL (range 6-20 μg/dL, n = 4) and 56 ± 49 μg/dL (range 22-148 μg/dL, n = 7) compared to a reference group with blood lead levels <1.0 μg/dL (n = 8). Blood and semen samples were collected once from each monkey in five different months. Serum testosterone levels were determined by radioimmunoassay, and lead effects on chromatin structure were analyzed by flow cytometry. There were no effects of treatment on circulating levels of testosterone or parameters of semen quality such as sperm count, viability, motility, and morphology. However, significant (p < 0.03) treatment-related effects were seen on SD αt values in the treated vs control animals. Group comparisons also revealed that the effects of chronic lead exposure were significant (p < 0.05)
Short-Term Exposure To Jp-8 Jet Fuel Results in Longterm Immunotoxicity
Authors: Harris David T. , Sakiestewa Debbie , Robledo Raymond F. , Wittent Mark
Published: September 2013

Chronic exposure to jet fuel has been shown to have adverse effects on human liver function, to cause emotional dysfunction, to cause abnormal electroencephalograms, to cause shortened attention spans, and to decrease sensorimotor speed. Due to the decision by the United States Air Force to implement the widespread use of JP-8 jet fuel in its operations, a thorough understanding of its potential effects upon exposed personnel is both critical and necessary. Exposure to potential environmental toxicants such as JP-8 may have significant effects on host systems beyond those readily visible (i.e., physiology, cardiology, respiratory, etc.); e.g., the immune system. Previous studies have shown that short-term, low concentration JP-8 exposure had significant effects on the immune system, which should have serious consequences for the exposed host in terms of susceptibility to infectious agents. If these alterations in immune function were long-lasting, it might also result in an increased likelihood of development and/or progression of cancer, as well as autoimmune disease.

In the current study, mice were exposed for 1 hlday for 7 days to a moderate (1000 mg/m 3) and a high (2500 mg/m3) concentration of aerosolized JP-8 jet fuel to simulate occupational exposures. One to 28 days after the last exposure the mice were analyzed for effects of the exposure on their immune systems. It was observed that decreases in viable immune cell numbers and immune organ weights found at 24 h after exposure persisted for extended periods of time. Further, JP-8 exposure resulted in significantly decreased immune function, as analyzed by mitogenesis assays, which persisted for up to 4 weeks post-exposure. Thus, short-term exposure of mice to JP-8 jet fuel caused significant toxicological effects on the immune system, which were long-lasting and persistent. It appears that the immune system may be the most sensitive indicator of toxicological damage due to JP-8 exposure. Such long-term changes in immune status may have significant effects on the health of the exposed individual.
The Effects of Carcinogenic Methylcholanthrene on Carbohydrate Residues of Nk Cells
Authors: Ghoneum Mamdooh , Vojdani Aristo , Banionis Arunas , Oppenheimer Steven , Lagos Nestor , Gill Gus
Published: September 2013

The present study examines the effect of methylcholanthrene (MCA), a carcinogenic polycylic hydrocarbon, on the carbohydrate receptor determinants (RD) on natural killer (NK) cell surface using the bead-coupled lectin assay. Murine NK cells exhibited different degrees of preferential binding to the specific lectins tested. Of the ten lectins tested, five exhibited a positive binding affinity while the remaining five exhibited no or insignificant binding. NK cells bind to beads derivatized with mannose specific lectins: Concanavalin A (Con A), Lens culinaris, and Pisum sativum. NK cells also bind to other lectin beads such as Triticum vulgaris (GalNac) and Vicia villosa (D-G1cNAc). All these lectin beads exhibited greater than 90% adhesion. The underivatized control beads exhibited no NK binding. The NK cells that were exposed to MCA for 2 h demonstrated a significant decrease in lectin bead-cell coupling in a dose dependent manner. MCA (10μg/mL) caused a 17.8%, 40% and 4.7% decrease in binding affinity when introduced to the mannose specific lectins; Con A, L. culinaris and P. sativum beads, respectively. The binding of T. vulgaris and V. villosa to NK cells was inhibited (23.4% and 28%) by MCA treatment. An increase in the dose to 20μg/mL resulted in a greater inhibition in binding affinity towards lectin beads, Con A, 35.3%, L. culinaris, 62.6%, P. sativum, 30.9%, T. vulgaris, 44.2% and V. villosa, 46.2%. The effect of MCA on the synthesis of NK polyphosphoinositides such as phosphatidylinositol 4-phosphate (PIP), phosphotidylinositol 4, 5- biphosphate (PIP2) was examined. The results showed lower phosphate 32 (32P)-labeling of PIP and PIP2 of MCA-treated NK cells as compared to untreated cells. Both of these MCA-induced cellular events (carbohydrate RD, PIP, and PIP2) may be interrelated at the level of transmembrane signal transduction, and may represent important steps in the inhibition of NK mediated cytotoxicity by this carcinogen.
Changes in Thyroid Hormone Economy Following Consumption of Environmentally Contaminated Great Lakes Fish
Authors: Leatherland John F.
Published: September 2013

Epizootics of thyroid lesions in fish and piscivorous birds that are resident in the Great Lakes region of North America suggest that there are environmental factors present in the Great Lakes ecosystem that act as potent endocrine disruptors, and that they are transferred along the food chain. This paper examines the results of wildlife studies, as well as related studies onfish-eating human populations in the region. It also re-examines the results of experimental studies of the effects of Great Lakes fish diets on the thyroid physiology of rodents and shows that the thyroid responses of fish-fed rats and mice were essentially similar to those found in rats that had been administered specific polyhalogenated aromatic hydrocarbon (PHAH) congeners or commercial polychlorinated biphenyl mixtures. However, the responses to the Great Lakes fish diets were found at PHAH exposure levels that were commonly several orders of magnitude lower than those applied in the classical toxicology studies. These findings, together with the results of the Great Lakes piscivorous bird studies and one in which captive common seals were fed "environmentally contaminated" fish, suggest that the "environmental" PHAH mixtures accumulated in fish represent a significant threat to the thyroid hormone economy, and the effects are greater than could be predicted by virtue of the known levels of active congeners in this naturally bioaccumulated PHAH mix.
Resistance To Thyroid Hormone: Implications for Neurodevelopmental Research On the Effects of Thyroid Hormone Disruptors
Authors: Hauser Peter , McMillin J. Michael , Bhatara Vinod S.
Published: September 2013

Thyroid hormones are essential for normal behavioral, intellectual, and neurological development. Congenital hypothyroidism, if not treated, can result in irreversible mental retardation, whereas thyroid diseases with more moderate impairment of thyroid function, such as resistance to thyroid hormone, cause less severe intellectual and behavioral abnormalities, including attention deficit hyperactivity disorder. There is increasing evidence that exposure to certain synthetic compounds, including dioxins and polychlorinated biphenyls (PCBs), during the perinatal period can also impair learning, memory, and attentional processes in offspring. Animal and human studies suggest that exposure to these environmental toxicants impair normal thyroidfunction. Although the precise mechanisms of action of the adverse effects these toxicants have on neurodevelopment have not yet been elucidated, it is possible that they are partially or predominantly mediated by alterations in hormone binding to the thyroid hormone receptor. The convergence of studies that examine the neurodevelopmental consequences of moderate impairment of thyroid function, such as is found in resistance to thyroid hormone, with those studies that demonstrate the adverse behavioral and cognitive effectsof perinatal exposure to dioxins and PCBs serves to generate new hypotheses to test in a research setting. Such studies may provide new insights into the basic pathogenesis of developmental neurotoxicity following exposure to thyroid-disrupting synthetic compounds.
Effects of Pesticides and Toxic Substances On Behavioral and Morphological Reproductive Development: Endocrine Versus Nonendocrine Mechanisms
Authors: Gray Leon Earl , Ostby Joseph
Published: September 2013

Exposure to toxic substances or pesticides during critical perinatal developmental periods can alter reproductive and central nervous system (CNS)function in a manner that does not compromise the growth and viability of the fetus but causes functional alterations that become apparent later in life. While some "CNS/behavioral teratogens" are mutagenic or alter cell division, other chemicals produce alterations of CNS development via endocrine-mediated mechanisms. The following discussion will focus on studies conducted primarily in our laboratory that describe how pesticides and toxic substances alter development of the reproductive and central nervous systems as a consequence of organizational or activational exposures. Abnormal behavior and morphology can result from exposure to endocrine-disrupting toxicants by altering organization of the CNS during critical stages of life or activation of behavior after puberty. Some of the toxicants that alter rodent sexual differentiation include xenoestrogens, antiandrogenic pesticides, and dioxin-like toxic substances. Chemicals that alter sex-linked nonreproductive and reproductive CNS development via nonhormonal mechanisms are also discussed in order to demonstrate that multiple mechanisms of action are involved in the development of behavioral abnormalities in pre- and perinatally exposed offspring. The fact that reproductive function (behavioral, biochemical, and morphological) can be altered via such a wide variety of mechanisms indicates that hazard identification in this area cannot rely solely on the detection of endocrine activity.
Hormonal Interactions in the Effects of Halogenated Aromatic Hydrocarbons On the Developing Brain
Authors: Maclusky Neil J. , Brown Theodore J. , Schantz Susan , Byung Woun Seo  , Peterson Richard E.
Published: September 2013

Halogenated arylhydrocarbons (HAHs) exert a wide range of effects on the developing brain. These effects result in altered patterns of neuroendocrine function and behavior in adulthood, as well as changes in cognitive function. The underlying mechanisms have not yet been clearly defined. This paper briefly reviews the effects of HAHs on brain development, and proposes the hypothesis that interactions between different hormone-sensitive systems may contribute to the broad spectrum of responses observed after fetal or early postnatal HAH exposure. Physiological interactions between the effects of sex steroids, corticosteroids, and thyroid hormone are known to influence the development of the central nervous system (CNS). Since the biosynthesis and/or action of each of these hormones is sensitive to developmental HAH exposure, it is suggested that convergent effects of HAHs on different endocrine pathways may underlie some of the disruptive effects of these chemicals on CNS differentiation. Data are presented indicating that the disruptive effects of low dose dioxin exposure on sexual differentiation of the rat brain are probably not mediated through blockade of estrogen responses, butmay instead involve subtle developmental changes in other endocrine systems, perhaps also affecting the feedback control of adrenocortical function. The potential for interactive endocrine effects illustrates the need for a fuller understanding of the range of biological activities of HAHs in the brain, so that the potential risks of low dose developmental exposure to these environmental toxicants can be predicted with greater certainty.
Methodological Analysis in Behavioral Toxicology: an Ethotoxicological Approach
Authors: Alleva Enrico , Rankin Judith , Santucci Daniela
Published: September 2013

A constraint in the development of laboratory animal models of human disease conditions is their applicability to the natural environment in which a given animal species evolved. The range of behavioral patterns that can be carefully assessed and quantified in the laboratory is sometimes limited. Although field studies reflect behavioral responses in natural settings, they may also have methodological limitations. Laboratory techniques are not applicable to wild species since natural conditions cannot be brought into a laboratory in an inexpensive or reliable way. However, it is possible to create near-natural settings which may not fulfill all the criteria of the actual context of evolution, but which can be controlled by the experimenter. We recommend an integrative style of approach considering laboratory constraints and, at the same time, the ecological niche in which a given behavioral pattern evolved. This type of ethological assessment may be useful when carrying out toxicological studies on both wild and laboratory mammals.
Health Effects Classification and Its Role in the Derivation of Minimal Risk Levels: Neurological Effects
Authors: Chou C-H Selene Jen , Williams-Johnson Mildred
Published: September 2013

The Agency for Toxic Substances and Disease Registry (ATSDR) uses substance-specific minimal risk levels (MRLs) to assist in evaluating public health risks associated with exposure to hazardous substances. By definition, "MRLs are estimates of daily human exposure to a chemical that are likely to be without an appreciable risk of adverse noncancer health effects over a specified duration of exposure. " MRLs serve as screening levels for health assessors to identify contaminants and potential health effects that may be of concern for population living near hazardous waste sites and chemical releases. MRLs for each substance are derived for acute (1-14 days), intermediate (15-364 days), and chronic (365 days and longer) exposure durations, and for the oral and inhalation routes of exposure. The MRLs are derived from data compiled from a current comprehensive literature search and are presented in ATSDR's toxicological profile for that substance. In this paper we outline ATSDR's guidance for evaluating the neurological end point as discussed in the agency's toxicological profiles. Ranking neurological effects into less serious and serious categories and applying this procedure to the derivation of health guidance values or MRLs are also described. Specific examples of ATSDR MRLs based on neurological effects are presented.
ATSDR Evaluation of Health Effects of Chemicals. V. Xylenes: Health Effects, Toxicokinetics, Human Exposure, and Environmental Fate
Authors: Fay Mike , Eisenmann Carol , Diwan Sanjivani , De Rosa Christopher
Published: September 2013

Xylenes, or dimethylbenzenes, are among the highest-volume chemicals in production. Common uses are for gasoline blending, as a solvent or component in a wide variety of products from paints to printing ink, and in the production of phthalates and polyester. They are often encountered as a mixture of the three dimethyl isomers, together with ethylbenzene. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals found at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) sites that are of greatest concern for public health purposes. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of the bulk of this profile (ATSDR, 1995) into the mainstream scientific literature. An extensive listing of known human and animal health effects, organized by route, duration, and end point, is presented. Toxicological information on toxicokinetics, biomarkers, interactions, sensitive subpopulations, reducing toxicity after exposure, and relevance to public health is also included. Environmental information encompasses physical properties, production and use, environmental fate, levels seen in the environment, analytical methods, and a listing of regulations. ATSDR, as mandated by CERCLA (or Superfund), prepares these profiles to inform and assist the public.
Considering Dialect in Survey Research
Authors: Renschler Isabelle , Kleiner Brian
Published: September 2013

This paper describes ways in which dialect variation may have important effects on the implementation and results of surveys in particular linguistic settings. Specifically, such differences of speech across populations within countries may significantly interfere with survey cooperation and with normal processes of understanding and responding to survey questions. The Swiss context is presented as a case study of how complications in survey implementation due to language and dialect variation may jeopardise data quality. Greater awareness among researchers of the potential impact of dialect variation on survey participation and responding is needed. Also, there is a need for more research internationally on the nature and scope of potential problems due to dialect, and on how to develop targeted strategies and remedies.
Flax and Breast Cancer
Authors: Flower Gillian , Fritz Heidi , Balneaves Lynda G. , Verma Shailendra , Skidmore Becky , Fernandes Rochelle , Kennedy Deborah , Cooley Kieran , Wong Raimond , Sagar Stephen , Fergusson Dean , Seely Dugald
Published: September 2013

Background. Flax is a food and dietary supplement commonly used for menopausal symptoms. Flax is known for its lignan, α-linolenic acid, and fiber content, components that may possess phytogestrogenic, anti-inflammatory, and hormone modulating effects, respectively. We conducted a systematic review of flax for efficacy in improving menopausal symptoms in women living with breast cancer and for potential impact on risk of breast cancer incidence or recurrence. Methods. We searched MEDLINE, Embase, the Cochrane Library, and AMED from inception to January 2013 for human interventional or observational data pertaining to flax and breast cancer. Results. Of 1892 records, we included a total of 10 studies: 2 randomized controlled trials, 2 uncontrolled trials, 1 biomarker study, and 5 observational studies. Nonsignificant (NS) decreases in hot flash symptomatology were seen with flax ingestion (7.5 g/d). Flax (25 g/d) increased tumor apoptotic index ( P < .05) and decreased HER2 expression ( P < .05) and cell proliferation (Ki-67 index; NS) among newly diagnosed breast cancer patients when compared with placebo. Uncontrolled and biomarker studies suggest beneficial effects on hot flashes, cell proliferation, atypical cytomorphology, and mammographic density, as well as possible anti-angiogenic activity at doses of 25 g ground flax or 50 mg secoisolariciresinol diglycoside daily. Observational data suggests associations between flax and decreased risk of primary breast cancer (adjusted odds ratio [AOR] = 0.82; 95% confidence interval [CI] = 0.69-0.97), better mental health (AOR = 1.76; 95% CI = 1.05-2.94), and lower mortality (multivariate hazard ratio = 0.69; 95% CI = 0.50-0.95) among breast cancer patients. Conclusions. Current evidence suggests that flax may be associated with decreased risk of breast cancer. Flax demonstrates antiproliferative effects in breast tissue of women at risk of breast cancer and may protect against primary breast cancer. Mortality risk may also be reduced among those living with breast cancer.
Outcomes and complication rates of different bone grafting modalities in long bone fracture nonunions: a retrospective cohort study in 182 patients
Authors: Flierl Michael A , Smith Wade R , Mauffrey Cyril , Irgit Kaan , Williams Allison E , Ross Erin , Peacher Gabrielle , Hak David J , Stahel Philip F
Published: September 2013

Background

Novel bone substitutes have challenged the notion of autologous bone grafting as the ‘gold standard’ for the surgical treatment of fracture nonunions. The present study was designed to test the hypothesis that autologous bone grafting is equivalent to other bone grafting modalities in the management of fracture nonunions of the long bones.

Methods

A retrospective review of patients with fracture nonunions included in two prospective databases was performed at two US level 1 trauma centers from January 1, 1998 (center 1) or January 1, 2004 (center 2), respectively, until December 31, 2010 (n = 574). Of these, 182 patients required adjunctive bone grafting and were stratified into the following cohorts: autograft (n = 105), allograft (n = 38), allograft and autograft combined (n = 16), and recombinant human bone morphogenetic protein-2 (rhBMP-2) with or without adjunctive bone grafting (n = 23). The primary outcome parameter was time to union. Secondary outcome parameters consisted of complication rates and the rate of revision procedures and revision bone grafting.

Results

The autograft cohort had a statistically significant shorter time to union (198 ± 172–225 days) compared to allograft (416 ± 290–543 days) and exhibited a trend towards earlier union when compared to allograft/autograft combined (389 ± 159–619 days) or rhBMP-2 (217 ± 158–277 days). Furthermore, the autograft cohort had the lowest rate of surgical revisions (17%) and revision bone grafting (9%), compared to allograft (47% and 32%), allograft/autograft combined (25% and 31%), or rhBMP-2 (27% and 17%). The overall new-onset postoperative infection rate was significantly lower in the autograft group (12.4%), compared to the allograft cohort (26.3%) (P < 0.05).

Conclusion

Autologous bone grafting appears to represent the bone grafting modality of choice with regard to safety and efficiency in the surgical management of long bone fracture nonunions.
Arginine improves peroxisome functioning in cells from patients with a mild peroxisome biogenesis disorder
Authors: Berendse Kevin , Ebberink Merel S , IJlst Lodewijk , Poll-The Bwee Tien , Wanders RonaldJ A , Waterham Hans R
Published: September 2013

Background

Zellweger spectrum disorders (ZSDs) are multisystem genetic disorders caused by a lack of functional peroxisomes, due to mutations in one of the PEX genes, encoding proteins involved in peroxisome biogenesis. The phenotypic spectrum of ZSDs ranges from an early lethal form to much milder presentations. In cultured skin fibroblasts from mildly affected patients, peroxisome biogenesis can be partially impaired which results in a mosaic catalase immunofluorescence pattern. This peroxisomal mosaicism has been described for specific missense mutations in various PEX genes. In cell lines displaying peroxisomal mosaicism, peroxisome biogenesis can be improved when these are cultured at 30°C. This suggests that these missense mutations affect the folding and/or stability of the encoded protein. We have studied if the function of mutant PEX1, PEX6 and PEX12 can be improved by promoting protein folding using the chemical chaperone arginine.

Methods

Fibroblasts from three PEX1 patients, one PEX6 and one PEX12 patient were cultured in the presence of different concentrations of arginine. To determine the effect on peroxisome biogenesis we studied the following parameters: number of peroxisome-positive cells, levels of PEX1 protein and processed thiolase, and the capacity to β-oxidize very long chain fatty acids and pristanic acid.

Results

Peroxisome biogenesis and function in fibroblasts with mild missense mutations in PEX1, 6 and 12 can be improved by arginine.

Conclusion

Arginine may be an interesting compound to promote peroxisome function in patients with a mild peroxisome biogenesis disorder.
Teacher-Student Relationships
Authors: Schiewer Tana
Published: September 2013

In this article, Schiewer examines the idea of hospitality in the classroom, which she notes has garnered a little more attention in recent scholarship. Though some of these examinations are quite complex, Schiewer offers a simplified approach marked by three principal ideas: provide simple instruction, build community while maintaining authority, and “befriend” students. To illustrate how this might be accomplished in the classroom, Schiewer reviews ideas put forth by Jerry Farber and Marshall Gregory, who promote being fully present and engaged with students. Schiewer concludes that by actively engaging students and knowing how to fairly balance critique, the hospitable classroom is ultimately a productive one.
“Say Rawr!”
Authors: Vallee Mickey
Published: September 2013

Jean-François Lyotard argued repeatedly that the biggest challenge a musician or composer faces is emancipating sound from the tyranny of grand narratives. They labor not in the service of expression but in the exploration of radical methods that constitute what Lyotard terms the “musical act”: a supervening decomposition of subjectivity through a sonic fold in space-time-sound. Thus composers work through and against musical customs to render audible what was once inaudible (or, simply, to render musical what was once noise). With varying degrees of exception, Lyotard's musical theory is conducive to Gilles Deleuze and Félix Guattari's assertion that music “deterritorializes the refrain.” In A Thousand Plateaus, Deleuze and Guattari argue that music enacts a becoming-minority that is, by its expressive deterritorializations, subversive to conventions of the categorical imperative. Music's essential building block, according to Deleuze and Guattari, is the nonmusical refrain. However, whereas Deleuze and Guattari diagnosed music's radical becoming as an expressive deterritorialization, Lyotard considered music as a political act by virtue of its nonexpressive desubjectivation. Had Lyotard abandoned his own straw man of romantic expressionism and instead adopted a Deleuzean expressionist aesthetic, his prescriptions for the political/musical act might have spanned beyond the domain of the European composers who remained virtually his only musical reference point. The solely unfortunate aspect regarding each thinker is precisely this myopic reliance on European high art music to illustrate their respective concepts. My elucidation of Lyotard's and Deleuze and Guattari's musical philosophy will contend that other composers located in the historical discourse of “popular music” would serve the concepts under discussion with more efficacy. Specifically, the music of Wesley Willis executes such a political/musical act through deterritorializing refrains that are expressed directly through the profane repetitions of musical technology.
Long term delivery of pulsed magnetic fields does not improve learning or alter dendritic spine density in the mouse hippocampus
Authors: Sykes Matthew , Makowiecki Kalina , Rodger Jennifer
Published: September 2013

Repetitive transcranial magnetic stimulation (rTMS) is thought to facilitate brain plasticity. However, few studies address anatomical changes following rTMS in relation to behaviour. We delivered 5 weeks of daily pulsed rTMS stimulation to ephrin-A2-/- and wildtype mice (n=10 per genotype) undergoing a visual learning task and analysed learning performance, as well as spine density, in the dentate gyrus molecular and CA1 pyramidal cell layers in Golgi-stained brain sections. We found that neither learning behaviour, nor hippocampal spine density was affected by long term rTMS. Our negative results highlight the lack of deleterious side effects in normal subjects and are consistent with previous studies suggesting that rTMS has a bigger effect on abnormal or injured brain substrates than on normal/control structures.
INFLUENCE OF GEOMETRY AND COOLING RATE ON PROPERTIES OF SINTER-HARDENED STEELS
Authors: Forno Ilaria , Actis Grande Marco
Published: September 2013

The aim of this paper is to deepen the understanding of the influence of the cooling step on the final properties of sinter-hardened components, mainly focusing on part geometry (through the definition of an A/M ratio) and cooling rate. A commercial Distaloy DH powder has been uniaxially pressed in different shapes, identified in terms of area/mass index, at three different compacting pressures (500, 600 and 800 MPa). During the sinter-hardening process, conducted in a belt-furnace, temperature profiles and atmosphere have been sampled and analysed. Particular attention has been paid to the cooling step, carried out at different furnace settings (10 to 80% of the maximum cooling capability in terms of fan speed). Sintered samples have been analysed in terms of carbon and oxygen content, hardness and microstructure. The considered properties have then been compared with dilatometer data, derived from literature. Matching these properties, a correlation between furnace setting, shape and microstructure has been drawn.
The emergency spine: part 2 – causes and diagnosis
Authors: Lowrie Mark
Published: September 2013

The vertebra column is a complex series of bones designed to protect the spinal cord; to allow movement and transmit propulsive forces; and provide support for the rest of the skeleton. As a consequence of these functions, it is very liable to injury and to degenerative changes, with diseases of the spinal column being far more common than diseases of the spinal cord. Despite the focus of this article being on diseases resulting in an emergency spinal presentation, it is worth remembering that any chronic compressive spinal cord disease can present acutely due to ongoing vascular and contusive injuries to the spinal cord. This article will focus only on the common diseases requiring emergency management.
Synthesis, Cytotoxicity and Antileishmanial Activity of Aza-stilbene derivatives
Authors: De Paula Daniela T. S. , De Carvalho Gustavo S. G. , Almeida Ayla C. , Lourenco Mariana , Da Silva Adilson D. , Coimbra Elaine S.
Published: September 2013

Stilbenes are compounds found in numerous medicinal plants and food products with some known biological and even antileishmanial activity. This paper describes the preparation of Aza-stilbene derivatives and their in vitro biological activities against Leishmania species. Most of the compounds with hydroxyl groups (2a, 2b, 2d, 2e and 2f) showed interesting results against three Leishmania species tested. Compound 2f showed the best activity against intracellular forms of L. amazonensis, with IC50 of 7.48 Î¼M, very similar when compared to reference drug Miltefosine. It not possible associate NO production with leishmanicidal activity for all aza-stilbene derivatives. It is noteworthy that none of compounds tested showed cytotoxicity against macrophages.