bluuebunny/crossref_metadata_2025 huggingface dataset:
Dental Implants with Locking Taper Connection versus Screwed Connection: Microbiologic and Scanning Electron Microscope Study
Authors: Pappalardo S. , Milazzo I. , Nicoletti G. , Baglio O. , Blandino G. , Scalini L. , Mastrangelo F. , Tetè S.
Published: May 2017

The aim of this study is to carry out an analysis of the Fixture-Abutment Interfaces (FAI), comparing different connection systems, to evaluate the role of geometric discrepancy, which is present between the abutment and the fixture, in favoring the permeability to bacterial colonization. Two types of commercially available FAI were studied, 16 screwed FAI (Sweden-Martina Italia) (4 of Ø 3.8 mm, 4 of Ø 4.7 mm, 4 of Ø 5.7 mm and 4 of Ø 6.7 mm) and 4 FAI (Bicon) (Ø 3.5mm). The assays were carried out in vitro, placing the different dental implants in contact with broth culture of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus pyogenes to test the infiltration inside the FAI. Furthermore, scanning electron microscope (SEM) analysis was carried out to evaluate the gap at the fixture-abutment interface. In all the locking taper FAI and in the screwed FAI with a diameter of 3.8 mm there was no trace of bacterial infiltration of the species examined. In the screwed FAI with a diameter of 4.7 mm, 5.7 mm and 6.7 mm there was an increasing level of bacterial infiltration in relationship to the diameter. Therefore, this paper shows that there exists an important correlation between the diameter of the screwed implant and the permeability to microbic infiltration that is directly proportional to the diameter of the implant.
NOS Evaluations in Human Dental Pulp-Capping with MTA and Calcium-Hydroxide
Authors: D'arcangelo C. , Di Nardo-Di Maio F. , Patrono C. , Caputi S.
Published: May 2017

The aim of this study is to compare mineral trioxide aggregate (MTA) with calcium hydroxide when used as pulp-capping material in human teeth. 40 teeth were divided into groups based on clinical diagnosis: healthy and hyperaemic. The teeth were pulp capped with MTA and calcium hydroxide. We localized the eNOS and iNOS by immunohistochemistry, tested their mRNA expression by RT-PCR and protein levels by western blots. The evaluation of the samples was based on the cell inflammatory response and on the pulp tissue organization. In particular, evaluation of eNOS and iNOS differences between the various groups and the cellular evolution after the first 7 days from the treatment, and at a distance of 28 days. Our results suggest that there are differences in localization and expression between eNOS and iNOS in dental pulp. Our study has helped us to better understand the effects that calcium hydroxide and MTA have on pulp tissue.
Bone Microstructure Evaluation near Unloaded Dental Implants Combining Confocal Scanning Laser Microscopy, Circularly Polarized Light Microscopy, and Sem Backscattered Electrons Imaging
Authors: Traini T. , Degidi M. , Murmura G. , Piattelli A. , Caputi S.
Published: May 2017

The aim of this report is to present a new investigative approach to implant dentistry based on the correlation of qualitative and quantitative data reported on the same figure by overlapping different images collected on the specimen with different investigative systems. Six unloaded titanium dental implants retrieved with peri-implant bone from the mandible of 2 patients after a 6 month period were used in this study. Samples of the peri-implant tissues embedded in resin were imaged by scanning electron microscopy using backscattered electrons signal (SEM BSE), confocal scanning laser microscopy (CSLM) and circularly polarized light microscopy (CPLM). The SEM BSE images were used to identify the different levels of mineral density. The CSLM images provided all the information on cells and bone marrow spaces. The CPLM images gave the collagen fibre orientation. To overlap the images we used a program introduced by Alan Boyde, based on a linear transformation matrix which projects one system onto the other. The total bone area investigated was of 695x103 pixels. The low mineral density index was 40.1, with an extension area of 344x103 ± 23x103 pixels (mean ± SD) while the high mineral density index was 54.8 with an extension area of 317x103 ± 22xl03 pixels (mean ± SD). Transverse collagen fibers showed an extension area of 201x103 ± 25x102 pixels (mean ± SD) (28.9%), while the area for longitudinal orientation was 282x103 ± 19x102 pixels (mean ± SD) (40.6%). The marrow spaces showed an extension of 113x103 ± 24x102 pixels (mean ± SD) (16.3%). This method demonstrated that bone near unloaded implants showed almost the same extension for longitudinal and transverse collagen fibre with a predominantly low mineral density index closest to the implant surface.
SEM Analysis of Oral Lichen Planus before and after Treatment with 13 Cis-Retinoic Acid
Authors: Mastrangelo F. , Dolci M. , Stuppìa L. , Paolantonio M. , Salinp L. , Zizzari V. , Tranasi M. , Patrono A. , Tetè S.
Published: May 2017

Cancer of the oral cavity is a frequent worldwide neoplasia, averaging 4% in men and 2% in women. Cancer of the oral cavity is often preceded by particular epithelial lesions, called “precancerous lesions”. The aim of this study is to evaluate, by SEM microscope analysis, before and after treatment with 0.1% 13-cis-retinoic, the morphostructural variation of the surface of the oral mucous affected by lichen planus in respect to healthy oral mucous. Following topical therapy with 0.1% 13-cis-retinoic acid for 8 weeks, a restoration of the physiological morphostructure was observed by SEM, demonstrating the efficaciousness of the treatment and the SEM analysis for identifying the lesions of oral epithelium.
The Performance of Human Periodontal Ligament Mesenchymal Stem Cells on Xenogenic Biomaterials
Authors: Trubiani O. , Scarano A. , Orsini G. , Di Iorio D. , D'arcangelo C. , Piccirilli M. , Sigismundo M. , Caputi S.
Published: May 2017

Mesenchymal stem cells from periodontal ligament (PDL-MSCs) hold great promise for bone regeneration. Most studies regarding the osteogenic differentiation of stem cells from periodontal tissue suggest that PDL cells may have many osteoblast-like properties, including the ability to form calcified nodules in vitro. This study investigated the morphological and histochemistry aspects of human PDL-MSCs, induced for osteogenic differentiation and seeded on a xenogenic porcine bone substitute in vitro, at different times of incubation. This biomaterial seems physically identical to human bone, and it has been reported to be osteoconductive. Our results indicated that the cells had a high affinity for the three-dimensional biomaterials; in fact, cellular proliferation and colonization was evident, and after 21 days the adherent cells started to detach themselves from the substrate, and at 30 days of incubation in differentiation medium, the cells completely lost the adhesion to the Petri's disk, englobing all bioparticles. In conclusion, the in vitro behaviour of PDL-MSCs and their relationship with three-dimensional scaffold biomaterials encourage in vivo investigations for their use in dental tissue regeneration.
Demineralizing Action of EGTA in Endodontics
Authors: Tripodi D. , D'ercole S. , De Fazio P. , Spoto G.
Published: May 2017

The demineralization of dentin obtained by treatment with a chelating agent ethylene diamminotetracetic acid (EDTA) or ethylene glycol-bis(β-aminoethyl ether)-N-tetraacetic acid (EGTA), is a dynamic process involving chelation and solubilization. The actions of the EDTA and EGTA on dentin are influenced by the pH. Increasing mM concentrations of EDTA or EGTA the equivalent pH decreases in a similar slope to 80 mM chelator concentration. Increasing the chelator concentration different data were obtained: with EGTA the pH decreases slightly while with EDTA goes back up to the initial values. After 80 mM, EDTA reduces the activity on the dentin, and EGTA continues to work at higher concentrations. We demonstrated that EGTA solubilized more of 60% of dentin while EDTA gives about 20% at the maximal of the solubility.
Formulation de cas dans la psychose débutante : Quels outils pour le travail en équipe?
Authors: Baumann Philipp S. , Elowe Julien , Mebdouhi Nadir , Solida Alessandra , Conus Philippe
Published: May 2017

Nous présentons d’abord brièvement le programme TIPP et les concepts généraux de la prise en charge précoce dans la psychose débutante. Un des objectifs de l’intervention dans la phase précoce des troubles psychotiques est notamment de proposer des soins spécifiques adaptés à cette phase de la maladie. En début de prise en charge, l’équipe de soins et en particulier le gestionnaire de cas (case manager), chef d’orchestre de la prise en charge, sont confrontés à une quantité importante d’information dont il faut dégager les lignes de forces pour mettre en place une prise en charge adaptée. Cet article propose un modèle qui peut constituer un outil de travail précieux pour les équipes travaillant dans l’intervention précoce pour faire émerger une formulation de cas et synthétiser les situations cliniques des patients, en extraire une histoire qui fasse sens et ainsi faciliter la mise en place d’un projet thérapeutique.
Video Communication With Cognitively Intact Nursing Home Residents: A Scoping Review
Authors: Schuster Amy M. , Hunter Elizabeth G.
Published: May 2017

Limited research exists examining video communication among cognitively intact nursing home residents to connect with family. This scoping review evaluated existing literature for video communication usage with nursing home residents, family, and nursing homes. A comprehensive search was completed using PubMed and EBSCOhost (including AgeLine, CINAHL, and PsycINFO) between 1972 and 2016 to locate English-language articles. The analysis identified five eligible studies (four involved an intervention, one assessed family views) meeting inclusion criteria. Findings included, seeing family members separated by distance, seeing other parts of their life, and visually monitoring resident’s health. Participants described frustration with technology limitations, such as video or audio lag. Current literature does not show a comprehensive assessment of video communication usage for residents, family, and nursing homes. Future studies should address the complexity of the intersection of the person, nursing home, and families in terms of potential benefits and capability of video communication use with residents.
Physiological Pharmacokinetic Models: Some Aspects of Theory, Practice and Potential
Authors: D'souza Richard W. , Boxenbaum Harold
Published: May 2017

Models are intellectual constructs that pattern selected relationships among the elements of one system to correspond in some way to elements of a second system. In pharmacokinetics, physiological models provide a clearly articulated, rational, explanatory basis for the integration of empirical data; they do this by partitioning the biological system into relevant components (tissues, organs, etc.) and linking them together through the circulatory system. Unlike conventional mammillary compartment models, there is a clear correspondence between model system elements and physiological entities. By virtue of their high degree of physical and biochemical relevance, these models can help provide deep insight into structure, function and mechanism. Pharmacokinetic (and potentially pharmacodynamic) response-time relationships can thus be understood in terms of interconnections and behavior of constituent subsystems. At their worst, these models provide stale or infertile views of reality and thus frustrate and alienate us with the triviality of their insights. At their best, they allow us to understand the accumulation of thought in pharmacokinetics and pharmacodynamics, and help with the integration of data and improvement of experimental design.
Respiratory Dose-Response Study of Normal and Asthmatic Volunteers Exposed to Sulfuric Acid Aerosol in the Sub-Micrometer Size Range
Authors: Avol Edward L. , Linn William S. , Whynot Jill D. , Anderson Karen R. , Shamoo Deborah A. , Valencia Lupe M. , Little David E. , Hackney Jack D.
Published: May 2017

Twenty-one healthy and 21 asthmatic volunteers were exposed to respirable sulfuric acid aerosol (mass median particle diameter approximately 0.9 pm, geometric standard deviation 2.5) in a chamber at 21° and 50% relative humidity. Measured sulfuric acid concentrations averaged 0, 380, 1060, and 1520 μg/m3 (in the occupational range, higher than concentrations observed in ambient air pollution). Exposures to different concentrations occurred in randomized order 1 week apart. They lasted 1 hr and included three 10-min periods of heavy exercise. Healthy volunteers showed no statistically significant changes in pulmonary function. airway reactivity to inhaled methacholine, or overall reporting of irritant symptoms which could be attributed to acid exposure. They did show a slight statistically significant (P <. 01) increase in cough with increasing acid concentration. At the two highest acid concentrations, asthmatics showed significant increases in irritant symptoms and decrements in pulmonary function, without significant changes in airway reactivity. Their function decrements appeared to increase with time during exposure. Previous studies in fog (10°, median particle diameter approximately 10 urn) with similar concentrations of sulfuric acid showed more symptoms but less pulmonary function change, perhaps reflecting different sites of particle deposition in airways and/or different degrees of neutralization by airway ammonia. This and earlier evidence predicts little, if any, acute irritant response in short-term (1 hr or less) exposures to sulfuric acid at concentrations found in ambient air pollution.
The Statistical Analysis of a Carcinogen Mixture Experiment. Ii. Carcinogens with Different Target Organs, N-Methyl-N'-Nitro-N-Nitrosoguanidine, N-Butyl-N-(4-Hydroxybutyl)Nitrosamine, Dipentylnitrosamine, and Nitrilotriacetic Acid
Authors: Fears Thomas R. , Elashoff Robert M. , Schneiderman Marvin A.
Published: May 2017

This paper describes factorial experiments designed to determine whether two carcinogens that act on different organ systems act synergistically to produce cancers in Fischer 344 rats. Four carcinogens, N-methyl-N'-nitrosoguanidine (MNNG), N-butanol-N-butylnitrosamine (NBBN), nitrilotriacetic acid (NTA), and dipentylnitrosamine (DPN) were studied in pairwise combinations. Each of the six possible pairs was studied by means of a 4 × 4 factorial experiment, each agent being fed at zero and at three non-zero doses. Methods of analysis designed explicitly for this study were derived to study interaction. These methods were supplemented by standard statistical methods appropriate for single agent studies. Antagonism was demonstrated in some chemical mixtures containing NTA. Other chemical mixtures did not interact. Findings for male and female animals were generally, but not always, in agreement.
Regulation of Pesticides in Canada
Authors: Ritter Leonard , Curry Patricia B.
Published: May 2017

Pesticides are registered in Canada under the authority of the Pest Control Products Act (PCP), administered by the Department of Agriculture. The Department of Agriculture calls upon various federal departments, including Health & Welfare Canada, to provide expert advice on hazards which may be associated with the use of the product.

The Department of Health and Welfare requires and reviews a range of toxicological studies to assess potential health hazards which may be associated with exposure to the chemical. Studies required include acute, sub-acute, chronic, reproduction, teratology and metabolism. In addition, exposure studies are also required to provide estimates of anticipated human exposure during typical field use of the chemical

In summary, the various steps involved in the registration of pesticides will be discussed and the relationship between the predictive toxicology as determined through animal testing and exposure estimates for estimating hazard will be shown.
Behavior as an Early Indicator of Pesticide Toxicity
Authors: Weiss Bernard
Published: May 2017

Adverse behavioral effects are now a recognized outcome of exposure to many industrial and environmental chemicals. Pesticides occupy a special role, however, because so many of them, particularly insecticides, are designed specifically to act on neural tissue. The evaluation of behavioral toxicity is a new kind of challenge to pesticide toxicology because of the enormous structural and chemical heterogeneity of the nervous system and the even greater complexity of behavior. Determining that a particular agent is neurotoxic is not an overwhelming problem; even elementary screens are capable of detecting nervous system activity. The greater challenge is to evaluate toxicity in the context of risk assessment, which requires techniques and experimental protocols capable of detecting the subtle manifestations that tend to appear early in the course of a toxic process. A combination of advanced behavioral methods, coupled with an emphasis on tracing the responses of individual organisms, is often optimal for achieving such a goal.
Biochemical and Morphological Validation of a Rodent Model of Organophosphorus-Induced Delayed Neuropathy
Authors: Padilla Stephanie , Veronesi Bellina
Published: May 2017

Exposure to certain organophosphates (OPs) produces a delayed degeneration of the longest and largest nerve fibers (OPIDN). Until recently, investigators have used the chicken as the primary experimental model of OPIDN. Although the chicken is extremely sensitive to the ataxia associated with this neuropathy, it lacks an extensive biochemical, electrophysiological and pathological data-base. Because of this we set out to develop a rodent model of OPIDN with morphological and biochemical correlates similar to those seen in the chicken. Historically the rat had been labeled insensitive to OPIDN because of its lack of demonstrable ataxia in response to the neuropathic OPs. This paper describes the validation of a rodent model with biochemical and morphological endpoints similar to those described in the clinical and experimental literature for other models of OPIDN.
Evaluation of Pesticide Immunotoxicity
Authors: Sharma R.P.
Published: May 2017

Immunotoxicologic effects have been reported for a number of pesticides. Since pesticides represent a large range of chemical classes, different types of chemicals may affect the complex immune system by a variety of mechanisms. A preliminary evaluation of pesticides for immunotoxicologic potential can best be incorporated in general subacute and chronic toxicity testing, with additional groups assigned for initial host-sensitivity assays. For chemicals that are possible candidates for immunotoxicity in preliminary assays, a comprehensive immunotoxicity screening has been suggested. Finally, emphasis should be given to mechanistic investigations to objectively assess the immunotoxicity of a new chemical and possible extrapolation to man. Animal models need to be developed for detecting the autoimmunologic potential of pesticides. This paper provides a brief listing of various approaches currently employed in the evaluation of immunotoxicity.
Evolution of Motor Activity Tests into a Screening Reality
Authors: Mullenix Phyllis J.
Published: May 2017

Measures of activity have changed in ways that their utility in screening for neurotoxicity has vastly improved. New computer pattern recognition systems now provide rapid, objective tools for identifying animal behavior. Advances in data analysis procedures have replaced the percent change in overall activity level with measures of initiations, total time and temporal structure for multiple behaviors and sequences. These advances can distinguish hyperactivities induced by different mechanisms and rank their neurotoxic potential, a feat not possible with photocell devices generally used in laboratories today. With the recent technological improvements, it is possible that a measure of activity will become one of the best predictors of malfunction in the central nervous system.
Applications of Electrophysiology in a Neurotoxicity Battery
Authors: Ross Joseph F.
Published: May 2017

Electrophysiology encompasses a multifaceted group of diagnostic tests which have been validated through clinical use. These evaluate not only CNS and PNS function, but also the function of the cardiovascular system, which affects the nervous system indirectly. As the many positive attributes of these tests become more widely recognized, it seems likely that the use of electrophysiologic tests will expand in the future.
Inhalation Toxicity of High Flash Aromatic Naphtha
Authors: Clark David G. , Butterworth Steven T. , Martin John G. , Roderick Howell R. , Bird Michael G.
Published: May 2017

A petroleum distillate—a high aromatic naphtha—consisting of a 50/50 blended mixture of equivalent products. SHELLSOL A* and SOLVESSO 100**, containing C9 isomers (75 percent)particularly trimethyl benzenes, was examined for systemic toxicity in rats by inhalation exposure. A preliminary 13-week inhalation study with SHELLSOL A had resulted in liver and kidney weight increases in female rats at the high (7400 mg/m3) and medium (3700 mg/m3) exposure levels, and a low grade anaemia in females at all exposure levels (7400, 3700 and 1800 mg/m3).

The follow-up 12-month inhalation study in rats described here used atmospheres generated from the SHELLSOL A/SOLVESSO 100 blend of 1800, 900 and 450 mg/m3. Initial reduction in body weight gain occurred in both male and female rats at the higher exposures. Various statistically significant haematological changes were transiently seen in males up to six months, but were not considered biologically significant. High exposure male liver and kidney weights were increased at 6 and 12 months but, in the absence of histopathological changes, were considered to be physiological adaptive responses. No treatment-related histopathological abnormalities were found. It is concluded that chronic exposure to this high aromatic naphtha is without systemic toxicity in rats under the conditions of these studies.
Health Effects of Oil Mists: A Brief Review
Authors: Mackerer Carl R.
Published: May 2017

Metal cutting/grinding fluids are of three basic types: straight oil (insoluble), oil-in-water emulsions (soluble) and synthetic/semi-synthetic. All contain a variety of additives to improve performance. Human exposure occurs primarily by direct skin contact with the liquid or by skin and respiratory contact after fluid misting.

Dermatitis caused by primary or direct skin irritation is the most prevalent health effect of exposure to cutting fluids. Occasionally allergic dermatitis is seen which is related to the development of sensitization to one or more of the additive components. Recent studies indicate that long-term exposure to cutting fluids does not result in increased incidences of lung cancer, urinary bladder cancer, gastrointestinal cancer, or death from non-malignant respiratory diseases. Long-term exposure to certain cutting fluids, however, is believed to have resulted in certain types of skin cancer, especially scrotal cancer. It is likely that these carcinogenic responses were caused by contact with polycyclic aromatic compounds (PCA) of 3–7 rings. Modern base oils which are severely refined have very low levels of PCA, are not carcinogenic in animal bioassays, and are unlikely to be carcinogenic in man. This is not necessarily true for re-refined oils which may contain significant levels of PCA and polychlorinated biphenyls derived from coming-ling used cutting oils with used engine oils and transformer oils. Cutting oils, themselves, generally do not accumulate significant levels of carcinogenic PCA during use.

Additives, in theory, can cause a variety of health effects either directly or through the generation of reaction products such as nitrosamines. In actual use, adverse health effects appear to be limited to occasional instances of allergic contact dermatitis. Nitrosamines are extremely carcinogenic in test animals; although no human cancer cases directly attributable to nitrosamine contamination have been observed, nitrosating agents and amines should not be combined in cutting fluid formulations.

It is difficult to anticipate or predict the potential toxicity of a particular cutting fluid formulation because of the presence of variable amounts of proprietary additives which, themselves, are often complex reaction mixtures. Thus, each additive and final formulation must be evaluated on a case by case basis to appropriately assess potential health hazards.
Pulmonary Function Responses of Young and Older Adults to Mixtures of O3, NO2 and Pan
Authors: Drechsler-Parks Deborah M. , Bedi John F. , Horvath Steven M.
Published: May 2017

The pulmonary function of 32 nonsmokers (eight men and eight women, 18–26 years of age; eight men and eight women, 51–76 years of age) was measured before and after two-hour exposures to (1) filtered air (FA), (2) 0.45 ppm ozone (O3), (3) 0.13 ppm peroxyacetyl nitrate + 0.45 ppm O3 (PAN/O3), (4) 0.60 ppm nitrogen dioxide + 0.45 ppm Os (NO2/O3), and (5) 0.13 ppm PAN + 0.60 ppm NO2 + 0.45 ppm O3 (PAN/NO2/O3). Subjects alternated 20-minute periods of rest and exercise (ventilation = 25 L/min). Forced vital capacity (FVC) was measured pre-exposure and five-minutes after each exercise period. Forced expiratory volume in one sec (FEV1.0) and forced expiratory flow between 25 and 75 percent of FVC (FEF25–75%) were calculated from the FVC tests. Data were analyzed by 4-factor analysis of variance (sex, age, time period, exposure). The responses of men and women were similar. FA exposure induced no effects. The young subjects' decrements in FVC, FEV10 and FEF25–75% became significant (P < 0.01) after the second exercise period of the O3, NO2/O3 and PAN/NO2/O3 exposures, while the PAN/O3 decrements were significant (P < 0.01) after the first exercise period. Although PAN/O3 induced significant decrements earlier than the other conditions including O3, the mean pre- to post-exposure decrements for the four conditions including O3 were similar. In contrast, the older subjects had smaller and fewer significant decrements in pulmonary functions. They had significant mean decrements in FVC following the third exercise period of the NO2/O3 and PAN/NO2/O3 exposures, in FEV1.0 after the third exercise period of the PAN/O3 and NO2/O3 exposures, and in FEF25–75% beginning after the second exercise period of the NO2/O3 exposure. The results suggest that older men and women are less responsive to O3 and mixtures of O3, NO2 and PAN than young men and women, and that O3 is responsible for the decrements observed in pulmonary function.
The Role of Enzyme Induction on Metabolite Formation of Bis(2-Methoxyethyl) Ether in the Rat
Authors: Cheever K. L. , Richards D. E. , Weigel W. W. , Begley K. B.
Published: May 2017

The effect of enzyme induction on the metabolism of the reproductive toxicant bis (2-methoxyethyl) ether (diglyme) was studied in male Sprague-Dawley rats. Rats were given either daily doses of diglyme at 5.1 mmol/kg body wt. by gavage or 0.1% (w/v)phenobarbital (PB) in the drinking water for 22 consecutive days. In one study, a significant reduction in the hexobarbital sleeping time was determined for rats pretreated with diglyme or PB in comparison with that determined for naive rats. In a second study, naive and pretreated rats given single oral doses of14C-diglyme at 5.1 mmol/kg body wt. showed similar urinary 14C excretion patterns. Urinary metabolites were separated and quantified by hplc to evaluate the influence of pretreatment with either diglyme or PB on the 14C-diglyme urinary metabolite profile. The amount of (2-methoxyethoxy) acetic acid, the principal metabolite, was similar for rats given no pretreatment and for rats pretreated with either diglyme or PB. However, both pretreatments resulted in significant increases in the formation of methoxyacetic acid, a recognized reproductive toxicant.
A Study of Mortality in Workers Engaged in the Mining, Smelting, and Refining of Nickel: Ii: Mortality from Cancer of the Respiratory Tract and Kidney
Authors: Roberts Robin S. , Julian James A. , Muir David C.F. , Shannon Harry S.
Published: May 2017

This paper describes observed and expected mortality from cancers of the lung, larynx, nose, and kidney in a cohort of 54,509 nickel workers followed for 35 years. For analysis purposes the cohort was subdivided into men with and without service in one of the three high nickel dust areas of the operation: the Sinter Plants at Copper Cliff and Coniston, and the Leaching, Calcining and Sintering (LC&S) department at Port Colborne. At Copper Cliff Sinter Plant workers experienced three times the expected number of lung cancer deaths; the SMR rose steeply with increasing duration of service peaking at 943 with 10 to 15 years. A similar overall excess risk of lung cancer was seen in the smaller Coniston Sinter Plant again with an indication of an exposure risk gradient. Men in the LC&S department at Port Colborne also experienced a dose related excess risk of lung cancer death that rose to an SMR of 806 with 20 to 25 years of service. Nasal cancer deaths were increased at both the Copper Cliff Sinter Plant (6 deaths) and the LC&S department at Port Colborne (19 deaths), representing SMRs of 3,704 and 7,755, respectively, for this rare cancer. Laryngeal cancer and kidney cancer, both previously associated with nickel, were not in excess in these high risk groups. A further exploration of death from these causes in the lower exposure remainder of the cohort revealed an epidemiologically modest elevation in lung cancer death in miners (probably not nickel related) and parts of the Copper Refinery. No evidence of laryngeal cancer excess was found. Kidney cancer death was slightly increased in miners but as a whole was reasonably in line with expected. The results are consistent with either nickel subsulphide or nickel oxide, or both, being carcinogens.
The Effect of Ozone and Simulated High Altitude on Murine Lung Elastin: Quantitation by Image Analysis
Authors: Damji Karim S. , Sherwin Russell P.
Published: May 2017

Four subgroups of a colony of 50 mice were housed in environmental chambers supplied by particle- and pollutant-filtered air. The animals were exposed to 0.35 ppm ozone and / or simulated high altitude (380 mm Hg) for four weeks, with exposure 41/2 hours / day and 5 days/week. Lung elastin area and alveolar wall area were quantitated by computer assisted image analysis of paraffin embedded sections stained with aldehyde fuchsin and metanil yellow. Compared to the controls, the combination of ozone and simulated high altitude resulted in a 54.5% increase in lung elastin area (p < 0.005), and simulated high altitude by itself increased elastin area by 19.6% (p < 0.05). Simulated high altitude with and without ozone exposure also increased alveolar wall area (24.8%, p < 0.01; and 9.7%, NS, respectively). Ozone exposure alone had a reverse effect: a 16.1% decrease in elastin area (p < 0.1), and a 6.5% decrease in alveolar wall area (NS). Since an intact lung scaffolding is required for full restoration of injured alveolar epithelium and since intact lung elastin is critical for proper lung compliance, the results suggest that ozone exposure at high altitude is most likely to have an adverse effect on lung structure and function.
Comparative Acute Toxicity of Shale and Petroleum Derived Distillates
Authors: Clark Charles R. , Ferguson Paul W. , Katchen Mark A. , Dennis Michael W. , Craig Douglas K.
Published: May 2017

In anticipation of the commercialization of its shale oil retorting and upgrading process, Unocal Corp. conducted a testing program aimed at better defining potential health impacts of a shale industry. Acute toxicity studies using rats and rabbits compared the effects of naphtha, Jet-A, JP-4, diesel and “residual” distillate fractions of both petroleum derived crude oils and hydrotreated shale oil. No differences in the acute oral (> 5 g/kg LD50) and dermal (> 2 g/kg LD50) toxicities were noted between the shale and petroleum derived distillates and none of the samples were more than mildly irritating to the eyes. Shale and petroleum products caused similar degrees of mild to moderate skin irritation. None of the materials produced sensitization reactions. The LC50 after acute inhalation exposure to Jet-A, shale naphtha, (> 5 mg/L) and JP-4 distillate fractions of petroleum and shale oils was greater than 5 mg/L. The LC50 of petroleum naphtha (> 4.8 mg/L) and raw shale oil (> 3.95 mg/L) also indicated low toxicity. Results demonstrate that shale oil products are of low acute toxicity, mild to moderately irritating and similar to their petroleum counterparts. The results further demonstrate that hydrotreatment reduces the irritancy of raw shale oil.
Preface
Authors: Williams Gary M.
Published: May 2017

Under the aegis of the Food and Nutrition Council and the Environmental Health Safety Council, the American Health Foundation convened the International Conference on Antioxidants, October 8-10, 1991 in Tarrytown, New York.
Effect of Small Doses of Ethylene Glycol Monomethyl Ether on the Acetylcholinesterase and A-Aminolevulinic Acid Dehydratase Activity in Erythrocytes, Blood and Bone Marrow of Rats
Authors: Lazewska M. , Tabarowski Z. , Dabrowski Z.
Published: May 2017

The effect of small doses of ethylene glycol monomethyl ether (EGMME) on the activity of acetylcholinesterase (ACHE) in erythrocytes and whole blood as well as on the Δ-aminolevulinic acid dehydratase (ALA-D) in blood and bone marrow was studied in Wistar rats. Significant reduction in the activity of both enzymes was noted three days after ip administration of 200 mg/kg b.w. EGMME whereas seven days later the activity of both enzymes returned to the control levels. Activity of ALA-D in blood appeared to be most sensitive to EGMME, and reacted even to the lowest dose, which did not significantly alter activity of ACHE or ALA-D in bone marrow. Haematological parameters in all treated groups remained unaltered.
Effects of Acute and Subchronic Exposure of Topically Applied Fullerene Extracts on the Mouse Skin
Authors: Nelson Mark A. , Domann Frederick E. , Bowden G. Tim , Hooser Stephen B. , Fernando Quintus , Carter Dean E.
Published: May 2017

The recent discovery that fullerenes (C60) can be produced in macroscopic quantities has sparked much interest in the chemistry of this unusual molecule. Concerns have also arose about the potential carcinogenic effects of this molecule. We have addressed the potential acute and subchronic toxic effects of fullerenes applied in benzene on the mouse skin. The acute toxic effects measured in this study included epidermal DNA synthesis and the induction of ornithine decarboxylase activity in the epidermis. At the topical dose of fullerenes used in these studies (i.e., 200 ug), we found no effect on either DNA synthesis or ornithine decarboxylase activity over a 72 hour time course after treatment. The subchronic effects of the fullerenes as a mouse skin tumor promoter was assessed by repeatedly applying the chemical to the skin after initiation with the polycyclic aromatic hydrocarbon, 7,12-dimethlybenz-anthracene (DMBA). Repeated administration of the fullerenes for up to 24 weeks post-initiation did not result in either benign or malignant skin tumor formation, whereas promotion with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in the formation of benign skin tumors. Our data indicate that fullerenes applied in benzene at a likely industrial exposure level do not cause acute toxic effects on the mouse skin epidermis.
Equity in Environmental Health: Data Collection and Interpretation Issues
Authors: Wagener Diane K. , Williams David R. , Wilson Patrick M.
Published: May 2017

In order to assess the issue of inequity in exposure to environmental hazards, researchers must identify subgroups whose exposure is disproportionately greater than the average exposure experienced by the remainder of the population. The general population is a complex mixture of subgroups, each consisting of individuals who experience a wide range of exposures and whose ability to cope with the consequences of those exposures is equally varied. Therefore, large efforts are needed to collect data that will enable researchers to determine compreliensively which subgroups are highly exposed and which subgroups have disproportionately greater health effects as a result of exposures to environmental hazards. The interpretation of findings is more of an art than a science, especially when two population subgroups are being contrasted. Addressing environmental equity requires explicit comparisons between groups, and racial and ethnic contrasts will be prominent. It is often difficult to identify the underlying mechanisms that produce particular patterns of results. However, researchers and policy makers must understand the dynamics that may have produced a particular pattern of results so they can separate those factors that are amenable to change from those that are not.
Air Pollution Health Risks: Do Class and Race Matter?
Authors: Sexton Ken , Gong Henry, , Bailar John C., , Ford Jean G. , Gold Diane R. , Lambert William E. , Utell Mark J.
Published: May 2017

Air pollution is not spread evenly across demographic groups. Exposures and associated health risks appear to fall disproportionately on populations that are poor and nonwhite. Although scientific evidence documenting disparities in air pollution exposures, doses, and health effects is scant, the available data strongly support the contention that disadvantaged groups, many of whom are ethnic and racial minorities, routinely encounter levels of air pollution that are higher than average. The extent to which exposure differentials contribute to observed differences in health status by class and race is unknown, but worthy of further investigation. We recommend several steps, all of them feasible and most of them relatively inexpensive, to improve our understanding and ability to address environmental health disparities.
The Agency for Toxic Substances and Disease Registry's Role in Development and Application of Biomarkers in Public Health Practice
Authors: Derosa Christopher T. , Stevens Yee-Wan , Wilson Jewell D. , Ademoyero Adedamola A. , Buchanan Sharunda D. , Cibulas William , Duerksen-Hughes Penny J. , Mumtaz Moiz M. , Neft Robin E. , Pohl Hana R. , Williams-Johnson Mildred M.
Published: May 2017

717 An overview of the Agency for Toxic Substances and Disease Registry's (ATSDR) biomarker program is presented in the context of the paradigm for biomarkers developed by the National Research Council (NRC, 1987, 1991). The status and projected utility of four biomarker studies conducted by NRC and sponsored by ATSDR, the Environmental Protection Agency (EPA), and the National Institute of Environmental Health Sciences (NIEHS) are discussed. These studies include a review of relevant research on biomarkers for specific toxicologic end points, including reproductive toxicology, pulmonary toxicology, neurotoxicology, and immunotoxicology. Also, the scope of related research on exposure characterization being conducted by the ATSDR-sponsored research program at Rutgers University is reviewed. The potential impact of biomarkers on public health assessments and on the range of ATSDR programs is described. Specifically, the role of biomarkers in dose reconstruction, in ATSDR's health studies program, and in the emerging field of molecular epidemiology is reviewed. In addition, future directions and research needs are addressed.
A Neurotoxicity Assessment of High Flash Aromatic Naphtha
Authors: Douglas J. Fielding , Mckee Richard H. , Cagen Stuart Z. , Schmitt Susan L. , Beatty Patrick W. , Swanson Mark S. , Schreiner Ceinwen A. , Ulrich Charles E. , Cockrell Beverly Y.
Published: May 2017

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide-boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 Aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent also known as High Flash Aromatic Naphtha (HFAN). A program was initiated to assess the toxicological properties of HFAN since there may be human exposure, especially in the workplace. The current study was conducted to assess the potential for neurotoxicity in the rat.

Adult male Sprague-Dawley rats of approximately 300 grams body weight, in groups of twenty, were exposed by inhalation to HFAN for 90 days at concentrations of 0, 100, 500, and 1500 ppm. During this period the animals were tested monthly for motor activity and in afunctional observation battery. After three months of exposure, for 6 hours/day, 5 days/week, 10 animals/group/sex were sacrificed and selected nervous system tissue was examined histopathologically. No signs of neurotoxicity were seen in any of the evaluated parameters, nor was there evidence of pathologic changes in any of the examined tissues.
Effects of Ammonium Dinitramide on Preimplantation Embryos in Sprague-Dawley RATS
Authors: Graeter Linda J. , Wolfe Robin E. , Kinkead Edwin R. , Flemming Carlyle D.
Published: May 2017

Ammonium dinitramide (ADN) is a class 1.1 oxidizer that may be used in rocket propellants and explosives. Previous studies have shown that ADN is a female reproductive toxicant, causing implantation failure in Sprague–Dawley rats when it is administered during the preimplantation period of gestation. The purpose of this follow-up study was to identify the mechanism(s) associated with implantation failure following exposure to ADN. Mated female rats were treated with 2.0 grams per liter (g l-1) ADN in their drinking water for 24, 48, 72, or 96 h before preimplantation embryos were harvested from the oviducts or uterine horns. On gestation day 1 (GD-1), comparable numbers of morphologically normal two-cell embryos were harvested from the oviducts of the treatment and control groups. On GD-2, the development of the embryos harvested from the treated animals was either slowed or halted when compared to the control embryos. By GD-4, 98% of the embryos harvested from the control group had developed to the morula or blastocyst stage; these were collected from the uterine horns. On GD-4 in the treated group, 41% of the harvested embryos remained at the two- to six-cell stage and 59% were degenerate; 82% of these embryos were collected from the oviducts. These data suggest that the implantation failure seen in animals treated with ADN is due to embryolethality.
Building-Related Illness and Employee Lost Time following Application of Hot Asphalt Roof: A Call for Prevention
Authors: Lynch Richard M. , Kipen Howard
Published: May 2017

Industrial hygiene sampling within an office building during and following a roof renovation revealed low-level exposure to high-boiling organic compounds, associated with complaints of eye and upper respiratory tract irritation among building occupants. Health complaints continued substantially beyond the time frame of the renovation completion, despite a lack of objective industrial hygiene findings for volatile organic compounds (VOCs) and microbiological contamination, and a lack of consistent medical findings among employees evaluated by an occupational physician. An analysis of employee attendance records suggests lost attendance and reduced productivity costs. Preventive strategies include proper planning and scheduling of building renovations to prevent employee exposure to asphalt roof emissions.
Adult Learning through Participation in Rural Community Groups
Authors: Whitmore Elizabeth , Sappington Harry W. , Compton J. Lin , Green Jennifer C.
Published: May 2017

This exploratory study investigates what adults learn through participation in community groups. An iterative content analysis was conducted on transcripts from ten in-depth interviews with active members of community groups throughout upstate New York. This process yielded 259 learning statements which were then classified into 8 learning categories. Here we present a rich description of what people learn in the context of local group activities. Understanding the learning that occurs in community group contexts has implications for adult educators and extension workers, as well as for the development of theoretical models of adult learning.
Boards of Directors in Nonprofit Organizations: Composition, Activities, and Organizational Outcomes
Authors: Miller Lynn E. , Weiss Richard M. , Macleod Bruce V.
Published: May 2017

Analyses of survey responses from the executive directors of 184 human service organizations examined the relationships of board characteristics to board activities, and of board activities to organizational outcomes. Results indicated that board characteristics most predictive of board activities were the numbers of board members who were representatives of the client population, who had expertise in marketing, who were trained in the types of service provided by the agency, and who regularly performed volunteer work for the agency. Although in general board activities had few statistical relationships with agency outcomes, the board's involvement in working to enhance the agency's image in the community was related to a number of outcome measures.
Effect of stitching on the flexure after impact behavior of thin laminated composites
Authors: Francesconi L , Aymerich F
Published: May 2017

The paper investigates the effect of stitching on the post-impact flexural performance of two classes of thin carbon/epoxy laminates. Unstitched and stitched laminated samples were first impacted with energies ranging between 1 J and 8 J by an instrumented drop-weight testing machine. The residual flexural properties of impacted samples were then assessed by three-point bending tests. The damage induced by impact and by post-impact bending was characterized in detail by visual inspection and penetrant-enhanced X-radiography. The results of the experimental analyses are illustrated and discussed to highlight the correlation between the residual flexural properties and the key fracture modes occurring in the laminates. The study shows that even though stitching is capable of improving the delamination resistance of the laminates, it may also drastically reduce their flexural strength. It is also seen that the residual post-impact flexural properties, which are controlled by the peculiar impact damage mechanisms of stitched and unstitched laminates, may be greatly degraded by impacts with energy above a critical threshold value.
The Road to Language Learning Is Not Entirely Iconic: Iconicity, Neighborhood Density, and Frequency Facilitate Acquisition of Sign Language
Authors: Caselli Naomi K. , Pyers Jennie E.
Published: May 2017

Iconic mappings between words and their meanings are far more prevalent than once estimated and seem to support children’s acquisition of new words, spoken or signed. We asked whether iconicity’s prevalence in sign language overshadows two other factors known to support the acquisition of spoken vocabulary: neighborhood density (the number of lexical items phonologically similar to the target) and lexical frequency. Using mixed-effects logistic regressions, we reanalyzed 58 parental reports of native-signing deaf children’s productive acquisition of 332 signs in American Sign Language (ASL; Anderson & Reilly, 2002) and found that iconicity, neighborhood density, and lexical frequency independently facilitated vocabulary acquisition. Despite differences in iconicity and phonological structure between signed and spoken language, signing children, like children learning a spoken language, track statistical information about lexical items and their phonological properties and leverage this information to expand their vocabulary.