bluuebunny/crossref_metadata_2025 huggingface dataset:
A Methodology for Assessing Carcinogenic Hazards of Chemicals
Authors: Szejnwald Brown Halina , Bishop Donna R. , West Carol Rowan
Published: September 2013

Assessment of carcinogenic hazards of substances involves evalua tion and classification of qualitative and quantitative data, includ ing the attendant uncertainty,. Recently proposed EPA guidelines represent a significant step towards a uniform carcinogenic risk assessment procedure and its appropriate use. The Methodology for Assessing Carcinogenic Hazards of Chemicals proposed here shares common characteristics with the EPA guidelines but it also focuses on other aspects of carcinogen assessment, not addressed by the guidelines, such as: folding together quantitative and quali tative data into a combined hazard index; classification of limited, incomplete or flawed qualitative data; utilization of quantitative risk estimates based on weak qualitative evidence.

The elements are used to assess carcinogenic hazards of chemicals, qualitative and quantitative. The qualitative assessment consists of stratification into one of five categories of weight-of evidence, whereas quantitative assessment consists of stratification into one of four potency categories on the basis of carcinogenic unit risk estimate. Carcinogenic hazard index, codified in letters A to E, is derived from the quantitative and qualitative elements of assess ment in a two-dimensional matrix. The matrix is designed so that weaker evidence for carcinogenicity requires a correspondingly higher unit risk value for a given score. Assessment of 100 chemicals using our methodology shows a good distribution of scores from A to E. Group B, which can be described as moderately hazardous, is most frequently represented. The methodology represents a mixture of two possible approaches to assessing hazards of carcinogens: one which gives the highest rank to those likely to produce the greatest risk, the other which ranks highest those most likely to produce cancer in humans. By using this com bined approach, it is ensured that a chemical hazardous on either count is not missed. The methodology also makes maximum use of all available data without over-interpreting some highly uncertain procedures such as quantitative risk estimation or extrapolation of animal response to humans.
Results of Peroxisome Induction Studies On Tri(2-Ethylhexyl)Trimellitate and 2-Ethylhexanol
Authors: Hodgson John R.
Published: September 2013

The results of these studies demonstrate that Tris(2-ethylhexyl)trimellitate (TOTM) produces the same spectrum of morphological and biochemical changes in the rat liver as di(2-ethylhexyl)phthalate (DEHP). TOTM, however, was much less potent in its action, witlt a dietary level of 2.0%, causing less peroxisome proliferation and enzyme induction than 0.67% DEHP. Also, these studies show that the level of peroxisome induction in rats given TOTM is less than in those receiving a metabolically equivalent dose of 2-ethylhexanol (2-EH). Furthermore, on a molar basis, effects were lower than with DEHP. A "monoester effect" of the kind attributed to MEHP, a metabolite of DEHP, was not seen with TOTM.
The Respiratory Responses of Subjects With Allergic Rhinitis To Ozone Exposure and Their Relationship To Nonspecific Airway Reactivity
Authors: McDonnell William F. , Horstman Donald H. , Abdul-Salaam Sa'id , Raggio Louis J. , Green James A.
Published: September 2013

Ozone exposure in man produces changes in respiratory function and symptoms. There is a large degree of unexplained intersubject variability in the magnitude of these responses. There is concern that individuals with chronic respiratory diseases may also be more responsive to ozone than normal individuals. The purpose of this study was to describe the responses of subjects with allergic rhinitis to ozone exposure and to compare these responses to those pre viously observed in normal individuals. A further purpose was to measure the association of baseline nonspecific airway reactivity with changes in lung function and respiratory symptoms following ozone exposure. A group of 26 nonasthmatic subjects with allergic rhinitis performed a bronchial inhalation challenge with histamine and subsequently underwent two hour exposures to both clean air and to 0.18 part per million ozone with alternating periods of rest and heavy exercise. The airway reactivity of this group of subjects was no greater than that of a comparable group of subjects without allergic rhinitis. The respiratory responses of these subjects to ozone exposure were similar to those previously reported for sub jects without allergic rhinitis with the exception that the allergic rhinitis subjects appeared to have a modestly increased broncho constrictor response compared to normals. Furthermore, we observed no significant relationships between nonspecific airway reactivity and response to ozone as measured by changes in lung function or the induction of symptoms.
Using the Nematode Caenorhabditis Elegans To Predict Mammalian Acute Lethality To Metallic Salts
Authors: Williams Phillip L. , Dusenbery David B.
Published: September 2013

The acute lethality of the salts of eight metals-HgCl2, BeSO4.4H2O, Al(NO3)3-9H2O, CuCl2-2H2O, ZnCl2, Pb(NO3)2, CdCl2, and Sr(NO3)2-was determined using a type of free-living nematode, Caenorhabditis elegans. The LC50 values were compared to the published mammalian oral LDso values for salts of the same metals. Within this set of chemicals, C. elegans was found to be a predictor of mammalian acute lethality, generating LC50 values parallel to the rat and mouse LD50 values. The total expenses for this testing are about 10% of the cost for mammalian acute lethality testing. The method is considered to have great promise, but further study is needed.
Prolonged Red Blood Cell Glycerol Hemolysis in Mice Inhaling Benzene
Authors: Goldstein Bernard D. , Rozen Michael G. , Snyder Carroll A.
Published: September 2013

Inhalation of benzene produces a prolongation of mouse red blood cell glycerol hemolysis time. This was not observed in red blood cells directly incubated in benzene. Increased resistance to the hemolytic action of glycerol should be explored as a potentially useful biological monitoring procedure in the red blood cells of benzene-exposed humans..
First Generation of a New Science: Risk Assessment in Transition3
Authors: Stara Jerry F.
Published: September 2013

The greatest challenge facing human populations today is that of extraordinary rapid change. Such a change in the society is illus trated by the increasing public awareness of environmental issues, accompanied by continuously expanding scientific investigations of chemical pollution. Our industrial civilization has developed and introduced into the various environmental media many compounds affecting human health individually and as a society. The science of toxicology is the evaluation of the effects of chemical and physical agents in various biological systems. Most chemical compounds cannot be tested in man due to their possible carcinogenic, muta genic, teratogenic, or other long-term toxic potential. Therefore, carefully designed toxicologic studies in other species, especially mammalian, are conducted to provide biological dose-response data, which can be used to predict human response. Toxicologists have the responsibility of providing accurate scientific dose- response data based on experiments employing, among others, "practical" concentrations of pollutants or toxicants. When the toxic effects are considered, the action of these agents in the atmosphere, water, and other environmental vehicles should be considered. There are always interacting events that co-exist in the environment. Multiple causality as a factor of a disease is well established but frequently overlooked. The various issues in envi ronmental health need to be tied together in order to be understood by scientists who are not intimately familiar with risk assessment procedures as they relate to the implementation of environmental laws. Much effort is needed both in the area of improved risk assessment methodology as well as in the area of toxicologic testing and validation of the theoretical approaches. The U.S. EPA is making every reasonable effort to improve its risk assessment approach.
Regulation of Carcinogens in Terms of Life Shortening
Authors: Albert Roy E. , Shukla Rakesh
Published: September 2013

Because of the difficulty in using the results of conventional quan titative risk assessment in the regulation of carcinogens, an approach to setting carcinogen standards is presented based on the reduction of cancer-induced life span shortening to statistically nonsignificant levels. An argument is made that the time of cancer occurrence is more important than the risk of cancer. The rationale is that the objective of carcinogen control is to delay the single-risk time of cancer occurrence. Whether this benefit is associated with a decrease, increase or no change in the risk of dying of cancer depends on concomitant changes in the temporal pattern of other causes of death. For indispensable carcinogens the permissible exposure is the level which shortens the time to background cancer by an amount equal to the uncertainty in the time of background cancer occurrence. This approach is illustrated by the use of the ED01 2-FAA bioassay on mice.
Bioavailability in Vivo of Benzo[a]Pyrene Adsorbed to Diesel Particulate
Authors: Bevan David R. , Ruggio David M.
Published: September 2013

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.
Toxicological Investigations in the Semiconductor Industry: I. Studies on the Acute Oral Toxicity of a Complex Mixture of Waste Products from the Aluminium Plasma Etching Process
Authors: Bauer Siegfried , Wolff Ilona , Werner Nadeshda , Hoffmann Peter , Herzschuh R. , Oemus Kerstin , Rath Friedrich Wilhelm , Voigt Reiner
Published: September 2013

In dry etching processes—one of the sources of potential exposure to toxic wastes in the semiconductor industry—complex mixtures of inorganic and organic compounds arise from reactions between feed stock gases (BCl3/Cl2), top layers (aluminium, photoresist), and the carrier gas (N2). Two different fractions of the complex mixture—one an ethanolic solution (ES) and the other an insoluble liquid residue (LR)—were examined for acute oral toxicity in rats. Analytical data showed that the ethanol soluble fraction contained mainly inorganic compounds, whereas the residue contained various halogenated hydrocarbons. Neither death nor behavioral changes occurred after oral administration and observation up to 23 days. ES caused a lower mean arterial blood pressure in both sexes, increased P-R-intervals in male rats, and caused some mild biochemical and hematological alterations and changes in relative organ weights compared to the control groups. Exposure to LR influenced food and water intake, and caused a significant decrease in body weights, signs of polyurie, as well as changes in various relative organ weights and biochemical and hematological parameters. The blood pressure of the male animals fell and the heart rates of both sexes decreased.
Effects of Hexachloro-1,3-Butadiene and 1,1,2,2-Tetrachloroethylene on Individual Serum Bile Acids
Authors: Bai Cheng-Long , Canfield Paul J. , Stacey Neill H.
Published: September 2013

Rats were exposed to hexachlorobutadiene (HCBD) or tetrachloroethylene (TET) in order to determine which of these chemicals was more likely to be responsible for elevations in individual serum bile acids (SBA) found in workers exposed primarily to these two chemicals. Increases in cholic and taurocholic acids were found on exposure to high doses of HCBD. Elevations of SBA occurred right down to low exposures for TET, however, with cholic, chenodeoxycholic, and glycocholic acids being the most sensitive bile acids. Only at high doses for each chemical was there any indication of liver injury as determined by routinely used parameters such as serum enzymes or bilirubin. The data suggest that TET is likely to play a role in the elevated individual SBA in an exposure situation where both this chemical and HCBD are found.
Methyl-Tertiary-Butyl Ether (MTBE) — a Gasoline Additive — Causes Testicular and Lympho Haematopoietic Cancers in Rats
Authors: Belpoggi Fiorella , Soffritti Morando , Maltoni Cesare
Published: September 2013

In the framework of a series of experiments conducted to evaluate the carcinogenic effects of oxygenated gasoline additives, MTBE was analyzed in an oral lifetime carcinogenicity study using 8-week-old male and female Sprague- Dawley rats. These experiments were part of a large research project on gasoline carcinogenicity performed at the Bentivoglio (BT) Castle Cancer Research Center of the Ramazzini Foundation and of the Bologna Institute of Oncology. MTBE, dissolved in oil, was administered by stomach tube at the doses of 1000, 250, or 0 mg/kg b.w., once daily, four days weekly, for 104 weeks. The animals were maintained until natural death. The last animal died 166 weeks after the start of the experiment, i.e., at 174 weeks of age. Under the tested experimental conditions, MTBE was shown to cause an increase in Leydig interstitial cell tumors of the testes and a dose-related increase in lymphomas and leukemias in female rats.
Reproductive Toxicity Screen of 1,3,5-Trinitrobenzene Administered in the Diet of Sprague-Dawley Rats
Authors: Kinkead E.R. , Wolfe R.E. , Flemming C.D. , Caldwell D.J. , Miller C.R. , Marit G.B.
Published: September 2013

Several Army installations targeted for restoration have measurable quantities of 1,3,5-trinitrobenzene (TNB) in the soil and groundwater. As part of the process of developing environmental and health effects criteria for restoration, a modified Screening Information Data Set (SIDS) reproductive study was performed. Male and female Sprague-Dawley rats received a diet containing approximately 30, 150, or 300 mg TNB/kg diet. Mating occurred following 14 days of treatment. All dams, one-half the males, and representative pups were maintained for a total of 90 days of treatment. No mortality occurred during the study; however, a decrease in mean body weights was noted in both sexes of high-dose rats. A dose-related effect was noted in measurements of sperm function/activity. Sperm depletion and degeneration of the seminiferous tubules were noted histopathologically. Methemoglobinemia and splenic hemosiderosis were common findings in the high- and mid-dose levels of both sexes at necropsy. No adverse effects were noted in mating or fertility indices. No significant treatment-related differences were found in length of gestation, sex ratio, gestation index, or mean number of pups per litter.
A Simple Index for Representing the Discrepancy between Simulations of Physiological Pharmacokinetic Models and Experimental Data
Authors: Krishnan Kannan , Haddad Sami , Pelekis Michael
Published: September 2013

The objective of this study was to develop an index that would provide a quantitative measure of the degree of discrepancy between simulations of physiologically based pharmacokinetic (PBPK) models and experimental data. The approach we developed involves the calculation of the root mean square of the error (representing the difference between the individual simulated and experimental values for each sampling point in a time course curve), and dividing it by the root mean square of the experimental values. The resulting numerical values of discrepancy measures for several data sets (each corresponding to an end point) obtained in a single experimental study are then combined on the basis of a weighting proportional to the number of data points contained in each data set. Such consolidated discrepancy indices obtained from several experiments (e.g., exposure scenarios, doses, routes, species) are averaged to get an overall discrepancy index, referred to as the PBPK index. This empirical index reflects the overall, weighted average percent difference between the a priori PBPK model simulations and experimental data. The proposed methodology is illustrated using previously published experimental and simulated data on dichloromethane pharmacokinetics in humans. The application of this kind of a "quantitative" method should help remove the ambiguity in communicating the degree of concordance or discrepancy between PBPK model simulations and experimental data.
Fish Consumption Advisories and Outreach Programs for Southeast Asian Immigrants
Authors: Shubat Pamela J. , Albright Raatz Kelly , Olson Roberta A.
Published: September 2013

Southeast Asian immigrants and refugees, in particular the Hmong people of Laos, have settled in large numbers in metropolitan areas of Minnesota. These communities, accustomed to hunting and fishing for food in Laos, now fish in some of the most contaminated waters of Minnesota. Fishing and fish- preparation customs of their homeland emphasize using all fish caught and discarding very little waste. These practices result in a potentially high exposure to PCBs and mercury. Educational outreach efforts to inform this population of the potential health hazards from consuming the fish are hindered by language and cultural barriers. While most Hmong anglers welcome information about contaminants and fishing, the typical press releases and mailings that convey fish advisory information to the public do not reach this community. The Minnesota Department of Health and the Minnesota Department of Natural Resources collaborated to determine the health messages and communication methods that would best meet the needs of these communities. Using the results of interviews and a behavioral survey, the Minnesota Department of Health has tailored fish consumption advisories to meet the unique needs of Southeast Asian anglers. Over the past four years, educational programs involving specialized advisories, translations, signs, a Hmong language video, and workshops have been used to inform Hmong anglers and other Southeast Asians about fish contaminants.
Dangerous and Cancer-Causing Properties of Products and Chemicals in the Oil-Refining and Petrochemical Industry—Part Xxii: Health Hazards From Exposure To Gasoline Containing Methyl Tertiary Butyl Ether: Study of New Jersey Residents
Authors: Mehlman Myron A.
Published: September 2013

Methyl tertiary butyl ether has caused the following cancers in rats and mice: kidney, testicular, liver, lymphomas, and leukemias. Thus, in the absence of adequate data on humans, it is biologically plausible and prudent to regard methyl tertiary butyl ether —for which there is sufficient evidence of carcinogenicity in experimental animals — as a probable human carcinogen. This means that some humans are at extreme risk of contracting cancers resulting from their exposure to oxygenated gasoline containing methyl tertiary butyl ether.

Immediately after the introduction of methyl tertiary butyl ether into gasoline, many consumers of this product in New Jersey, New York, Alaska, Maine, Pennsylvania, Colorado, Arizona, Montana, Massachusetts, California, and other areas, experienced a variety of neurotoxic, allergic, and respiratory illnesses. These illnesses were similar to those suffered by refinery workers from the Oil, Chemical, and Atomic Workers Union who mixed methyl tertiary butyl ether with gasoline. Additionally, these illnesses occurredfollowing exposure to extremely low levels of methyl tertiary butyl ether in gasoline, particularly when compared to the adverse health effects that occurred only after exposure to very high levels of conventional gasoline. Thus, gasoline containing methyl tertiary butyl ether exhibited substantially more toxicity in humans than gasoline without this additive.

A number of oil industry-sponsored or influenced reports alleged that these illnesses were either unrelated to exposure to reformulated gasoline or were characteristic of some yet-to-be-identified communicable disease. These studies further alleged that the widespread concern was not about illness, but was merely a reaction to the odor and the five cent increase in the price of gasoline.

To clarify the significance of this issue, it is important to note that consumers have been using gasoline for many decades, with complaints only occurring following exposure to high levels at 100s ppm or higher. After the introduction of methyl tertiary butyl ether gasoline there were thousands of human health complaints. The sudden increase in widespread illnesses from which many thousands of individuals throughout the United States began to suffer immediately following the introduction of methyl tertiary butyl ether into gasoline provides strong and unquestionable evidence that gasoline containing methyl tertiary butyl ether is associated with human illnesses. When considering the severity of the illnesses in humans, it is prudent that this highly dangerous chemical be promptly removed from gasoline and comprehensive studies be conducted to assess the long-term effects that human may experience in the future from past and current exposure.
Atsdr Evaluation of Health Effects of Chemicals. Iv. Polycyclic Aromatic Hydrocarbons (PAHs): Understanding a Complex Problem
Authors: Mumtaz M.M. , George J.D. , Gold K.W. , Cibulas W. , Derosa C.T.
Published: September 2013

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 PAHs. PAHs generally occur as complex mixtures (for example, as part of products such as soot), not as single compounds. PAHs are found throughout the environment in the air, water, and soil. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals, including PAHs (ATSDR, 1995), found atfacilities on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) and which pose the most significant potential threat to human health, as determined by ATSDR and the Environmental Protection Agency (EPA). These profiles include information on health effects of chemicals from different routes and durations of exposure, their potential for exposure, regulations and advisories, and the adequacy of the existing database. Assessing the health effects of PAHs is a major challenge because environmental exposures to these chemicals are usually to complex mixtures of PAHs with other chemicals. The biological consequences of human exposure to mixtures of PAHs depend on the toxicity, carcinogenic and noncarcinogenic, of the individual components of the mixture, the types of interactions among them, and confounding factors that are not thoroughly understood. Also identified are components of exposure and health effects research needed on PAHs that will allow estimation of realistic human health risks posed by exposures to PAHs. The exposure assessmentcomponent of research should focus on (1 ) development of reliable analytical methods for the determination of bioavailable PAHs following ingestion, (2) estimation of bioavailable PAHs from environmental media, particularly the determination of particle-bound PAHs, (3) data on ambient levels of PAHs metabolites in tissueslfluids of control populations, and (4) the need for a critical evaluation of current levels of PAHs found in environmental media including data from hazardous waste sites. The health effects component should focus on obtaining information on (1) the health effects of mixtures of PAHs particularly their noncarcinogenic effects in humans, and (2) their toxicokinetics. This report provides excerpts from the toxicological profile of PAHs (ATSDR, 1995) that contains more detailed information.
Determination of the Distribution of Malathion in Rats Following Various Routes of Administration by Whole-Body Electronic Autoradiography
Authors: Saleh Mahmoud A. , Ahmed Ahmed E. , Kamel Alaa , Dary Curtis
Published: September 2013

The distribution of [14C]-malathion, an organophosphorus pesticide, in rats after intravenous, oral and dermal administration was carried out using electronic autoradiography of whole body sections of treated animals. The study indicated that a major difference in the disposition of [14C]-malathion occurred following various routes of administration to rats. Following intravenous administration, the liver and kidney accumulated extremely high levels of the chemical. After oral administration, [14C]-malathion absorption from the stomach was slow and its excretion followed mostly the fecal route. Dermal application of [14C]-malathion may represent a high risk for exposure to the organophosphorus pesticide where the entire skin, not only the site of application, may act as reservoir for the compound.
Impact of Pcbs On Thyroid Hormone Directed Brain Development
Authors: Porterfield Susan P. , Hendry Lawrence B.
Published: September 2013

Thyroid hormones regulate neuronal proliferation, migration, process outgrowth, synaptic development, and myelin formation in specific brain regions. Because brain development occurs during discrete windows of time, inappropriate levels of thyroid hormones in definitive periods can produce permanent damage, the nature of which depends upon the timing and magnitude of the insult. Thyroid hormones cross the placenta and enter the brain primarily as thyroxine (T4); therefore, conditions selectively lowering serum T4 levels alter brain hormone availability. Triiodothyronine (T3) is the predominant form of the hormone that binds to the receptor. T3 is produced from T4 in the brain by the enzyme type II, 5'-deiodinase. Polychlorinated biphenyls (PCBs) are synthetic environmental toxicants that bear a striking structural resemblance to the active thyroid hormones and can, depending upon the species, dosage, and congener used, act as agonists, antagonists, and partial agonists to thyroid hormones.
Phytoestrogens: Potential Endocrine Disruptors in Males
Authors: Santti Risto , Mäkelä Sari , Strauss Leena , Korkman Johanna , Kostian Marja-Lsa
Published: September 2013

Exposure to diethylstilbestrol (DES) induces persistent structural and functional alterations in the developing reproductive tract of males. It is possible that xenoestrogens other than DES alter sexual differentiation in males and account for the increasing incidence of developmental disorders of the reproductive tract in men and wild animals. Phytoestrogens (coumestans, isoflavonoids, flavonoids, and lignans) present in numerous edible plants are quantitatively the most important environmental estrogens when their hormonal potency is assessed in vitro. They exert their estrogenic activity by interacting with estrogen receptors (ERs) in vitro. They may also act as antiestrogens by competing for the binding sites of estrogen receptors or the active site of the estrogen biosynthesizing and metabolizing enzymes, such as aromatase and estrogen-specific 17β-hydroxysteroid oxidoreductase (type 1). In theory, phytoestrogens and structurally related compounds could harm the reproductive health of males also by acting as antiestrogens.

There are very little data on effects of phytoestrogens in males. Estrogenic effects in wildlife have been described but the evidence for the role of phytoestrogens is indirect and seen under conditions of excessive exposure. In doses comparable to the daily intake from soy- based feed, isoflavonoids such as genistein were estrogen agonists in the prostate of adult laboratory rodents. When given neonatally, no persistent effects were observed. In contrast, the central nervous system (CNS)-gonadal axis and the male sexual behavior of the rat appear to be sensitive to phytoestrogens during development. The changes were similar but not identical to those seen after neonatal treatment with DES, but higher doses of phytoestrogens were needed.There are no data on effects of phytoestrogens given as pure compounds to humans, and all evidence currently available is indirect and based on experiments with phytoestrogen- rich diets. The hormonal effects have so far been marginal. It is known that the intake of phytoestrogens is higher in countries where the incidence rates of clinical conditions linked to estrogen exposure, such as hypospadia or testicular and prostatic cancers, are low. This makes it unlikely that phytoestrogens, or structurally related compounds in amounts present in Asian diets, would have DES-like actions. This does not exclude possibilities that they influence concentrations of endogenous sex hormones and interact with the ER, and that through these mechanisms they alter male sex differentiation, and consequently increase the risks of male genital tract tumors or developmental disorders, particularly in doses exceeding the daily intake of phytoestrogens in Asian diets.
A Physiologically Based Approach To the Study of Bisphenol a and Other Estrogenic Chemicals On the Size of Reproductive Organs, Daily Sperm Production, and Behavior
Authors: Vom Saal Frederick S. , Cooke Paul S. , Buchanan David L. , Palanza Paola , Thayer Kristina A. , Nagel Susan C. , Parmigiani Stefano , Welshons Wade V.
Published: September 2013

Two chemicals previously shown to have estrogenic activity, bisphenol A and octylphenol, were examined for their effects on accessory reproductive organs and daily sperm production in male offspring of mice fed these chemicals during pregnancy. These chemicals are used in the manufacture of plastics and other products, and have been detected in food and water consumed by animals and people. From gestation day 11-17 female mice were fed an average concentration (dissolved in oil) of bisphenol A or octylphenol of 2 ng/g body weight (2 ppb) and 20 ng/g (20 ppb). The 2 ppb dose of bisphenol A is lower than the amount reported to be swallowed during the first hour after application of a plastic dental sealant (up to 931 μg; 13.3 ppb in a 70 kg adult). We found that the 2 ng/g dose of bisphenol A permanently increased the size of the preputial glands, but reduced the size of the epididymides; these organs develop from different embryonic tissues. At 20 ng/g, bisphenol A significantly decreased efficiency of sperm production (daily sperm production per g testis) by 20% relative to control males. The only significant effect of octylphenol was a reduction in daily sperm production and efficiency of sperm production at the 2 ng/g dose. A new approach to studying physiologically relevant doses of environmental endocrine disruptors is discussed, particularly with regard to the development of the reproductive organs, the brain, and behavior.
Biomarkers as Diagnostic and Prognostic Tools for Wildlife Risk Assessment: Integrating Endocrine-Disrupting Chemicals
Authors: Fossi Maria Cristina
Published: September 2013

The state of art of the biomarker approach in ecotoxicology is reviewed with particular reference to its use in the assessment of exposure to endocrine-disrupting chemicals in wildlife. The following topics are discussed: the theoretical basis of the biomarker approach; the advantages of biomarker strategies in biomonitoring programs; application of biomarker strategies in an ecotoxicological context; the main biomarker techniques; interpretation of the results; and the development and validation of nondestructive biomarkers.
Effects of Cadmium On Liver Function in Diabetic Rats
Authors: Rana Suresh V.S. , Rastogi Nidhi
Published: September 2013

Hepato-toxicity of cadmium in alloxan induced diabetic rats has been studied by estimating a few enzymes viz serum glutamic oxalacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase and γ-glutamyltranspeptidase. Present results suggest that cadmium manifests difterent effects in normal and diabetic rats. Insulin therapy helps in restoring the liver function. It is suggested that an isozyme of cytochrome P450 that appears in diabetic rats might be responsible for altered toxicity of cadmium.
Empirical Data and Theory Construction
Authors: Cipriani Roberto
Published: September 2013

The classical approach in sociology, as much as in other scientific fields, consists in the use of hypotheses and hypothesis testing processes to determine what, if any, effects can be attributed to particular factors in the case being studied. Other scholars however propose another procedure that eliminates the presence of previous hypotheses and privileges an interpretive – as opposed to a hypothetic-deductive – approach to data analysis. However, in the latter approach crucial questions appear for the researcher: how does one approach the data and data analyses to ensure the credibility of findings? Blumer's suggestion of “sensitizing concepts” seems to be appropriate in order to reach not only reliable interpretations of data but also to retain the possibility of “building theory”. This process could be supported by computer-assisted research.
L'analyse des réseaux sociaux - Un survol à travers quelques jalons
Authors: Degenne Alain
Published: September 2013

The Social Network Analysis - An Overview via Certain Milestones: Social network analysis has multidisciplinary origins (anthropology, social psychology, sociology, mathematics). It brings with it to sociology a point of view based on the study of social circles, on one hand, and relations between persons, on the other. Social cohesion, social roles, mediation, diffusion of innovations and ideas, small world, social capital, etc. are among the topics to which social network analysis has provided interesting insights. This text is based on the keynote presentation at the 15-20 September 2008 CNRS Summer School on social networks in Cargèse, Corsica.
Validation of the Adult Manifest Anxiety Scale–College Version Scores in a Sample of U.S. College Students
Authors: Lowe Patricia A.
Published: September 2013

Two studies examined the psychometric properties of the Adult Manifest Anxiety Scale–College Version (AMAS-C) scores among U.S. college students. In Study 1, 300 college students were administered the AMAS-C. Confirmatory factor analyses (CFAs) indicated that the five-factor model (four anxiety factors and one lie factor) with a higher order factor provided the best fit to the data. In Study 2, 177 college students were administered the AMAS-C and external measures and correlational analyses indicated support for the convergent and discriminant validity of the AMAS-C scores. Implications of the findings of the studies for mental health professionals who work with college students are discussed.
Towards a better understanding of Rift Valley fever epidemiology in the south-west of the Indian Ocean
Authors: Balenghien Thomas , Cardinale Eric , Chevalier Véronique , Elissa Nohal , Failloux Anna-Bella , Jean Jose Nipomichene Thiery Nirina , Nicolas Gaelle , Rakotoharinome Vincent Michel , Roger Matthieu , Zumbo Betty
Published: September 2013

Rift Valley fever virus (Phlebovirus, Bunyaviridae) is an arbovirus causing intermittent epizootics and sporadic epidemics primarily in East Africa. Infection causes severe and often fatal illness in young sheep, goats and cattle. Domestic animals and humans can be contaminated by close contact with infectious tissues or through mosquito infectious bites. Rift Valley fever virus was historically restricted to sub-Saharan countries. The probability of Rift Valley fever emerging in virgin areas is likely to be increasing. Its geographical range has extended over the past years. As a recent example, autochthonous cases of Rift Valley fever were recorded in 2007–2008 in Mayotte in the Indian Ocean. It has been proposed that a single infected animal that enters a naive country is sufficient to initiate a major outbreak before Rift Valley fever virus would ever be detected. Unless vaccines are available and widely used to limit its expansion, Rift Valley fever will continue to be a critical issue for human and animal health in the region of the Indian Ocean.
Air ions and respiratory function outcomes: a comprehensive review
Authors: Alexander Dominik D , Bailey William H , Perez Vanessa , Mitchell Meghan E , Su Steave
Published: September 2013

Background

From a mechanistic or physical perspective there is no basis to suspect that electric charges on clusters of air molecules (air ions) would have beneficial or deleterious effects on respiratory function. Yet, there is a large lay and scientific literature spanning 80 years that asserts exposure to air ions affects the respiratory system and has other biological effects.

Aims

This review evaluates the scientific evidence in published human experimental studies regarding the effects of exposure to air ions on respiratory performance and symptoms.

Methods

We identified 23 studies (published 1933–1993) that met our inclusion criteria. Relevant data pertaining to study population characteristics, study design, experimental methods, statistical techniques, and study results were assessed. Where relevant, random effects meta-analysis models were utilized to quantify similar exposure and outcome groupings.

Results

The included studies examined the therapeutic benefits of exposure to negative air ions on respiratory outcomes, such as ventilatory function and asthmatic symptoms. Study specific sample sizes ranged between 7 and 23, and studies varied considerably by subject characteristics (e.g., infants with asthma, adults with emphysema), experimental method, outcomes measured (e.g., subjective symptoms, sensitivity, clinical pulmonary function), analytical design, and statistical reporting.

Conclusions

Despite numerous experimental and analytical differences across studies, the literature does not clearly support a beneficial role in exposure to negative air ions and respiratory function or asthmatic symptom alleviation. Further, collectively, the human experimental studies do not indicate a significant detrimental effect of exposure to positive air ions on respiratory measures. Exposure to negative or positive air ions does not appear to play an appreciable role in respiratory function.
Therapeutic effect and tolerability of gelatin sponge particle-mediated chemoembolization for colorectal liver metastases: a retrospective study
Authors: Li Chuang , Zhang Yuewei , Zhou Jun , Zhao Guangsheng , Tang Shunxiong
Published: September 2013

Background

Colorectal cancer (CRC) is one of the most common cancers worldwide. The majority (approximately 60%) of patients with CRC will eventually develop liver metastases, which remain the most common cause of mortality in these patients. This study aimed to evaluate the therapeutic effect and tolerability of gelatin sponge particle (GSP)-mediated chemoembolization in the treatment of colorectal liver metastases after systemic chemotherapy failure.

Methods

This was a single-center retrospective study of 15 patients with colorectal liver metastases, who underwent GSP-mediated chemoembolization with 50 mg of lobaplatin during the period December 2009 to December 2010 in the Department of Interventional Radiology, Affiliated Zhongshan Hospital of Dalian University. Clinical data were retrieved, and the therapeutic effect and tolerability of the treatment were evaluated.

Results

All 15 patients with colorectal liver metastases completed the GSP-mediated chemoembolization. The therapeutic effect and tolerability were evaluated 3 months after the initial procedure. The tumor lesions in all patients showed various levels of necrosis and shrinkage. According to the Response Evaluation Criteria in Solid Tumors (RECIST), one patient achieved complete response (CR), eleven patients achieved partial response (PR), and three patients achieved stable disease (SD). The overall response rate (CR + PR) was 80%.

Conclusions

GSP-mediated chemoembolization is well tolerated and has a good short-term response rate (80%) in the treatment of colorectal liver metastases after systemic chemotherapy failure. Collectively, further study of the long-term effect of GSP-mediated chemoembolization in colorectal liver metastasis in a large cohort is warranted.
Who Are You Calling “Coddled”?
Authors: Risse Marielle
Published: September 2013

The article discusses the necessary compromises inherent in choosing interesting, authentic, and appropriate texts for Middle Eastern classrooms. With nine years’ experience teaching literature in the Arabian Peninsula, Risse argues that the choice of texts and the methods of teaching should reflect local culture instead of transplanting Western syllabi.
Thirteen Ways of Looking at an Essay
Authors: Hogue Bev
Published: September 2013

Why would an English professor enroll in an upper-level biology class? This article describes an experiment in interdisciplinarity: an English professor takes a class titled Scientific Imaging in order to enhance her teaching of nature writing. The author outlines thirteen specific lessons imparted by her experience as a student in a class devoted to photographing elements of the natural world and creating images suitable for scientific presentation, and then she explains how she adapted the principles from Scientific Imaging for use in a creative nonfiction class focusing on nature writing. The article concludes with a discussion of the results of this interdisciplinary experiment and suggestions for promoting interdisciplinary learning as a mode of faculty development.
EFFECT OF ALLOYING ELEMENTS ON PROPERTIES OF PM Ti-Al-Si ALLOYS
Authors: Novák Pavel , Kříž Jan , Michalcová Alena , Vojtěch Dalibor
Published: September 2013

This work was devoted to the description of the effect of alloying by transition metals (Cr, Cu, Fe) on the structure and properties of TiAl15Si15 alloy. Alloying elements does not form separate phases, being dissolved in titanium silicide or aluminide. Cu was found predominantly in aluminide phase, while iron was found to bethe silicide-former. Chromium dissolved in both aluminide and silicide in almost comparable amounts. All applied alloying elements increased the wear resistance, but reduced the room-temperature compression strength. The addition of iron and chromium strongly increase the thermal stability at 1000°C by stabilizing the silicide phase.
Preparation and Characterization of NaA Zeolite Membranes and its Application for Removal of Heavy Metals
Authors: Tijani Najib , Ahlafi Hammou , Smaihi Monique , El Mansouri Abdeslam
Published: September 2013

In this work, the characteristics of low cost NaA zeolite membranes for heavy metal removal from synthesised solutions are presented. These membranes were elaborated on a clay macroporous support which were prepared and characterized by XRD, SEM and N2 permeation. The effects of synthesis parameters such as temperature T and time t on the proprieties of the NaA zeolite membranes were investigated. The best experimental conditions for synthezised membranes are obtained for T = 60 Â°C, t = 24 h and 117 L m-2 h-1 bar-1 for a water flux of membrane.The tests for the removal of Pb(II), Zn(II) and Cr(VI), conducted on these NaA zeolite membranes, show respectively the rejection reached 99%, 99% and 12% after 1 hour of filtration at 7 bars of N2 and at ambient temperature.
Fluorescence quenching of uric acid solubilized in bicontinuous microemulsion by nitrobenzene
Authors: O. Iwunze Maurice
Published: September 2013

Uric Acid is known to be practically insoluble in aqueous and alcoholic media. However, it exhibits a reasonable solubility in a Bicontinuous Microemulsion system â€“ a 15-fold or more increase in solubility in thisÂ system compared to its solubility in water. The bicontinuous microemulsion is made up of three components â€“Dodecane-Surfactant-water. Uric acid solubilized in this system is quenched by nitrobenzene. The obtainedÂ fluorescence data do not obey the Stern-Volmer equation when plotted accordingly. Therefore, the modified Stern-Volmer equation was used to analyze the data. It was observed that only one third (1/3) of uric acid isÂ accessible to quenching in this medium and the reaction is diffusion-limited. The Stern-Volmer quenching constant, KSV, was calculated to be 130 M-1 and the fluorescence lifetime, 00, the quantum yield,ï¦, and theÂ bimolecular quenching rate constant, kq, were calculated as 10.6 nanoseconds, 0.06 and 1.23ï‚´1010 M-1s-1, respectively.
Animal Diversity Web as a Teaching & Learning Tool to Improve Research & Writing Skills in College Biology Courses
Authors: Yahnke Christopher J. , Dewey Tanya , Myers Phil
Published: September 2013

Most teachers agree that writing is an important skill for students to master, yet not all teachers incorporate writing assignments in their courses. Employers agree that written communication is important for college graduates, yet in a survey, less than 10% of employers thought that colleges did a good job preparing students for work. Writing an animal species account for Animal Diversity Web (http://animaldiversity.org) provides students with a real-world example of writing skills and provides resources to instructors who want to incorporate writing in their classes.
Circling Back: Reconstituting Ethnic Community Networks among Aging Filipino Americans
Authors: Tiamzon Trisha J.
Published: September 2013

Although there is an expansive literature on the assimilation and transnational experiences of middle-aged immigrants and their second-generation children, little work examines the experiences of immigrant elderly, particularly Asian Americans. Existing scholarship on segmented assimilation has generally assumed that elderly immigrant experiences continue the trajectories of middle age. Drawing on in-depth interviews with elderly Filipino American immigrants, the author finds a shift from the white middle-class mainstream path to an ethnic networks path of incorporation. Although middle-class immigrants may exhibit patterns and living situations similar to native whites throughout most of their lives, their experiences as racialized Americans may prompt desires to reconnect with ethnic networks in later life. This pattern, in which groups that have ostensibly assimilated throughout their life course recreate ethnic communities near the end of it, is rendered visible through a framework the author terms life course assimilation, which emphasizes the need to study assimilation processes at all life stages.