ISRN Toxicology

Safety Evaluation of Engineered Nanomaterials for Health Risk Assessment: An Experimental Tiered Testing Approach Using Pristine and Functionalized Carbon Nanotubes

Teresa Coccini, Luigi Manzo, and Elisa Roda — Wed, 17 Apr 2013 08:47:20 +0000

Increasing application of engineered nanomaterials within occupational, environmental, and consumer settings has raised the levels of public concern regarding possible adverse effects on human health. We applied a tiered testing strategy including (i) a first in vitro stage to investigate general toxicity endpoints, followed by (ii) a focused in vivo experiment. Cytotoxicity of laboratory-made functionalized multiwalled carbon nanotubes (CNTs) (i.e., MW-COOH and MW-NH2), compared to pristine MWCNTs, carbon black, and silica, has been assessed in human A549 pneumocytes by MTT assay and calcein/propidium iodide (PI) staining. Purity and physicochemical properties of the test nanomaterials were also determined. Subsequently, pulmonary toxic effects were assessed in rats, 16 days after MWCNTs i.t. administration (1 mg/kg b.w.), investigating lung histopathology and monitoring several markers of lung toxicity, inflammation, and fibrosis. In vitro data: calcein/PI test indicated no cell viability loss after all CNTs treatment; MTT assay showed false positive cytotoxic response, occurring not dose dependently at exceedingly low CNT concentrations (1 μg/mL). In vivo results demonstrated a general pulmonary toxicity coupled with inflammatory response, without overt signs of fibrosis and granuloma formation, irrespective of nanotube functionalization. This multitiered approach contributed to clarifying the CNT toxicity mechanisms improving the overall understanding of the possible adverse outcomes resulting from CNT exposure.

Ecotoxicity of Nanoparticles

Sachindri Rana and P. T. Kalaichelvan — Sun, 24 Mar 2013 11:51:33 +0000

Nanotechnology is a science of producing and utilizing nanosized particles that are measured in nanometers. The unique size-dependent properties make the nanoparticles superior and indispensable as they show unusual physical, chemical, and properties such as conductivity, heat transfer, melting temperature, optical properties, and magnetization. Taking the advantages of these singular properties in order to develop new products is the main purpose of nanotechnology, and that is why it is regarded as “the next industrial revolution.” Although nanotechnology is quite a recent discipline, there have already high number of publications which discuss this topic. However, the safety of nanomaterials is of high priority. Whereas toxicity focuses on human beings and aims at protecting individuals, ecotoxicity looks at various trophic organism levels and intend to protect populations and ecosystems. Ecotoxicity includes natural uptake mechanisms and the influence of environmental factors on bioavailability (and thereby on toxicity). The present paper focuses on the ecotoxic effects and mechanisms of nanomaterials on microorganisms, plants, and other organisms including humans.

Influence of Mikania laevigata Extract over the Genotoxicity Induced by Alkylating Agents

Tue, 05 Mar 2013 13:20:07 +0000

Medicinal plants are still widely used worldwide; yet for some species, little or no information is available concerning their biological activity, specially their genotoxic and antimutagenic potential. Mikania laevigata (Asteraceae) is a native plant from South America, and its extracts are largely used to treat respiratory complaints. The aim of the present work was then to evaluate, in vivo, the potential biological activity of M. laevigata on the genotoxicity induced by methyl methanesulfonate (MMS) and cyclophosphamide (CP), using the comet assay. Male CF1 mice were divided into groups of 5-6 animals, received by gavage 0.1 mL/10 g body wt of water, Mikania laevigata extract (MLE), MMS, and CP. Results showed that treatment with 200 mg/kg of the MLE previously to MMS and CP administration, respectively, reduced the damage index (DI) in 52% and 60%, when compared to DI at 24 h. Pretreatment also reduced the damage frequency (DF) in 56% (MMS) and 58% (CP), compared to DF at 24 h. MLE administration has been shown to protect mouse DNA from damage induced by alkylating agents; this corroborates to the biological activities of M. laevigata and points towards the need of plant compounds isolation to proceed with further studies.

Genotoxicological Evaluation of NUTRALYS Pea Protein Isolate

Wed, 27 Feb 2013 11:10:33 +0000

NUTRALYS Pea Protein Isolate, a protein supplement, is a high-quality source of protein which is primarily emulsifying functional protein. We evaluated the genotoxic potential of NUTRALYS isolated from dry yellow pea, using three established genotoxicity tests (AMES test in vitro chromosomal aberration test, and in vivo micronucleus test) employing OECD guidelines under GLP conditions. In the bacterial reverse mutation test, NUTRALYS did not show positive responses in strains detecting point and frame shift mutations. In the chromosomal aberration test, NUTRALYS did not induce chromosome aberrations in the presence and absence of metabolic activation. In the bone marrow micronucleus test, NUTRALYS did not induce significant increases of micronucleated immature (polychromatic) erythrocytes in bone marrow of test animals.

Role of Calcium Channels in Heavy Metal Toxicity

Carla Marchetti — Wed, 30 Jan 2013 10:37:06 +0000

The role of voltage-dependent Ca channels (VDCC) in the membrane permeation of two toxic metals, lead (Pb) and cadmium (Cd), was studied in mammalian cells. Both metals interact with Ca-binding sites, but, while Cd influx appears to occur mainly through the same pathways as Ca, Pb is also rapidly taken up by different passive transport systems. Furthermore, I compared the effect of Cd in two Chinese hamster ovary (CHO) cell lines, a wild-type and a modified cell line, which were permanently transfected with an L-type VDCC. When cultures were subjected to a brief (30–60 min) exposure to 50–100 μM Cd, apoptotic features, metal accumulation, and death were comparable in both cell lines although, in transfected cells, the effect of Cd treatment was partially prevented by nimodipine (VDCC antagonist) and enhanced by BayK8644 (VDCC agonist). Thus, expression of L-type Ca channels is not sufficient to modify Cd accumulation and sensitivity to a toxicological significant extent and while both Cd and Pb can take advantage of VDCC to permeate the membrane, these transport proteins are not the only, and frequently not the most important, pathways of permeation.

Cadmium Transport in a Model of Neonatal Intestinal Cells Correlates to MRP1 and Not DMT1 or FPN1

Sun, 27 Jan 2013 13:05:23 +0000

Newborns have a higher gastrointestinal uptake of cadmium than adults. In adults, the iron transporters DMT1 and FPN1 are involved in the intestinal absorption of cadmium, while in neonates, the mechanisms for cadmium absorption are unknown. We have investigated possible cadmium transporters in the neonatal intestine by applying a model of immature human intestinal epithelial Caco-2 cells. To mimic the continuous cadmium exposure via diet in neonates, cells were allowed to differentiate for 7 days in medium containing 1 μM CdCl2. A dramatic upregulation of the MT1 gene expression followed cadmium pretreatment, indicating a high sensitivity of the immature cells to cadmium. Cadmium pretreatment increased the basolateral efflux of 109Cd, without causing any effects on the passive diffusion of mannitol or the transepithelial electrical resistance. The augmented transport of cadmium was correlated to an upregulation of MRP1 gene expression and increased activity of the efflux protein MRP1. No effects were observed on gene expression of the efflux proteins MRP2 and P-gp or the iron transporters DMT1, DMT1-IRE and FPN1. In conclusion, our data indicate that continuous cadmium exposure increases the absorption of the metal in immature intestinal cells and that MRP1 is involved in the intestinal cadmium absorption in newborns.

Antinociceptive Activity and Redox Profile of the Monoterpenes (+)-Camphene, p-Cymene, and Geranyl Acetate in Experimental Models

Mon, 14 Jan 2013 13:46:01 +0000

Objective. To evaluate antinocicpetive and redox properties of the monoterpenes (+)-camphene, p-cymene, and geranyl acetate in in vivo and in vitro experimental models. Methods. Evaluation of the in vitro antioxidant activity of (+)-camphene, p-cymene, and geranyl acetate using different free radical-generating systems and evaluation of antinociceptive actions by acetic acid-induced writhing and formalin-induced nociception tests in mice. Results. p-Cymene has the strongest antinociceptive effect, but (+)-camphene and geranyl acetate also present significant activity at high doses (200 mg/kg). (+)-Camphene had the strongest antioxidant effect in vitro at TBARS and TRAP/TAR assays and also had the highest scavenging activities against different free radicals, such as hydroxyl and superoxide radicals. Sodium nitroprussiate-derived NO production was enhanced by (+)-camphene. Geranyl acetate and p-cymene also presented some antioxidant effects, but with a varying profile according the free radical-generating system studied. Conclusion. (+)-Camphene, p-cymene, and geranyl acetate may present pharmacological properties related to inflammation and pain-related processes, being potentially useful for development of new therapeutic strategies, with limited possibilities for p-cymene and geranyl acetate.

Assessment of Polycyclic Aromatic Hydrocarbon Contamination of Breeding Pools Utilized by the Puerto Rican Crested Toad, Peltophryne lemur

Jenessa Gjeltema, Michael Stoskopf, Damian Shea, and Ryan De Voe — Sun, 16 Dec 2012 13:12:55 +0000

Habitat preservation and management may play an important role in the conservation of the Puerto Rican crested toad, Peltophryne lemur, due to this species’ small geographic range and declining native wild population. Bioavailable water concentrations of Polycyclic Aromatic Hydrocarbon (PAH) contaminants within breeding pools at 3 sites were established using Passive Sampling Devices (PSDs) and gas chromatography-mass spectrometry (GC/MS). A more diverse population of PAH analytes were found in higher concentrations at the breeding site that allowed direct vehicular access, but calculated risk quotients indicated low risk to toad reproduction associated with the current PAH analyte levels.

In Vitro-In Vivo Correlation Evaluation of Generic Alfuzosin Modified Release Tablets

Utpal Kumar Sanki and Badal Kumar Mandal — Tue, 20 Nov 2012 11:04:48 +0000

Alfuzosin, a selective alpha-1a antagonistis is the most recently approved AARAS, with limited cardiac toxicity and exclusively used for lower urinary tract syndromes (LUTS). In order to reduce pill burden and better patient compliance modified release (MR) formulations have been developed. Alfuzosin MR tablet was developed by the use of hot-melt granulation techniques using mono- and diglycerides as rate controlling membranes to minimize health care cost and uses of costly excipients. The other purpose of the study was to evaluate in vitro-in vivo performance of the scale up batch in healthy human subjects for commercialization. The blend uniformity (mean ± RSD%), assay, cumulative percent dissolution at 24 h, hardness, and friability of the biobatch were 100.2 ± 0.05%, 100.43 ± 0.023%, 93.98%, 4.5 kg, 5 min, and 0.08%, respectively. The in vivo pharmacokinetic parameters under fasting conditions between test and reference formulations (Uroxatral 10 mg extended release tablets) were comparable. The 90% CI, geometric mean ratio (%) and power of , AUCT, and AUCI of the fasting study for the test and reference formulation were 99.03% to 122.78%, 109%, 0.998; 92.94% to 116.71%, 104%, 1; 98.17% to 124.01%, 110% 1, respectively. The scale up biobatch showed negligible difference in in vitro properties with respect to the pilot batch. The formulation developed with these agents was safe to use as there were no serious adverse events developed during the conduction of the clinical trial on the healthy subjects. Furthermore, the developed formulation was bioequivalent with respect to rate and extends of absorption to the reference formulation.

Nitric Oxide Synthase Gene Transfer Overcomes the Inhibition of Wound Healing by Sulfur Mustard in a Human Keratinocyte In Vitro Model

Wed, 14 Nov 2012 13:22:02 +0000

Sulfur mustard (SM) is a chemical warfare agent that causes extensive skin injury. Previously we reported that SM exposure resulted in suppression of inducible nitric oxide synthase (iNOS) expression to inhibit the healing of scratch wounds in a cultured normal human epidermal keratinocyte (NHEK) model. Based on this finding, the present study was to use adenovirus-mediated gene transfer of iNOS to restore the nitric oxide (NO) supply depleted by exposure to SM and to evaluate the effect of NO on wound healing inhibited by SM in NHEKs. The effect of the iNOS gene transfer on iNOS protein expression and NO generation were monitored by Western blot and flow cytometry, respectively. Wound healing with or without the iNOS gene transfer after SM exposure was assessed by light and confocal microscopy. The iNOS gene transfer via adenovirus resulted in overexpression of the iNOS and an increase in NO production regardless of SM exposure in the NHEK model. The gene transfer was also effective in overcoming the inhibition of wound healing due to SM exposure leading to the promotion of wound closure. The findings in this study suggest that the iNOS gene transfer is a promising therapeutic strategy for SM-induced skin injury.

Toxicity Assessment of Expired Pesticides to Green Algae Pseudokirchneriella subcapitata

Wed, 14 Nov 2012 09:47:41 +0000

In order to investigate the effect of expired pesticides on the yield and growth rate of green algae Pseudokirchneriella subcapitata, a study was conducted as per the Organisation for Economic Cooperation and Development (OECD) guideline number 201. Fifteen expired pesticide formulations, most commonly used in Indian agriculture, were tested in comparison with their unexpired counterparts. The expired pesticide formulations studied belonged to various class and functional groups: organophosphate, pyrethroid-based insecticides; azole-based fungicides; acetamide, propionate, acetic acid-based herbicides; fungicides mixtures containing two actives—azole and dithiocarbamate. The toxicity endpoints of yield (C50: 0–72 h) and growth rate (C50: 0–72 h) of Pseudokirchneriella subcapitata for each pesticide formulation (both expired and unexpired pesticides) were determined statistically using TOXSTAT 3.5 version software. The results pointed out that some expired pesticide formulations exhibited higher toxicity to tested algal species, as compared to the corresponding unexpired pesticides. These data thus stress the need for greater care to dispose expired pesticides to water bodies, to avoid the effects on aquatic ecospecies tested.

Bmoo FIBMP-I: A New Fibrinogenolytic Metalloproteinase from Bothrops moojeni Snake Venom

Sun, 04 Nov 2012 13:47:02 +0000

A new fibrinogenolytic metalloproteinase (Bmoo FIBMP-I) was purified from Bothrops moojeni snake venom. This enzyme was isolated through a combination of three chromatographic steps (ion-exchange, molecular exclusion, and affinity chromatography). Analyses by reverse phase chromatography, followed by mass spectrometry, showed the presence of enzyme isoforms with average molecular mass of 22.8 kDa. The SDS-PAGE analyses showed a single chain of 27.6 kDa, in the presence and absence of reducing agent. The protein has a blocked N-terminal. One of the peptides obtained by enzymatic digestion of a reduced and S-alkylated isoform was completely sequenced by mass spectrometry (MS/MS). Bmoo FIBMP-I showed similarity with hemorrhagic factor and several metalloproteinases (MP). This enzyme degraded A-chain faster than the B-chain and did not affect the -chain of bovine fibrinogen. The absence of proteolytic activity after treatment with EDTA, together with the observed molecular mass, led us to suggest that Bmoo FIBMP-I is a member of the P-I class of the snake venom MP family. Bmoo FIBMP-I showed pH-dependent proteolytic activity on azocasein, but was devoid of coagulant, defibrinating, or hemorrhagic activities. The kinetic parameters of proteolytic activity in azocasein were determined ( and ).

In Vitro Effects of Herbicides and Insecticides on Human Breast Cells

Jessica D. Rich, Seth M. Gabriel, and Jennifer R. Schultz-Norton — Sun, 14 Oct 2012 18:44:32 +0000

Numerous studies have indicated that the pesticides and herbicides used in agricultural processes in the United States and Europe may have detrimental effects upon human health. Many of these compounds have been indicated as potential endocrine and reproductive disruptors, although the studies have examined supraphysiological levels well above the US EPA safe levels for drinking water and have often examined these effects in “model” cell lines such as Chinese hamster ovary cells. We have now examined the cytotoxicity of more environmentally relevant concentrations of four herbicides, acetochlor, atrazine, cyanazine, and simazine, and two insecticides, chlorpyrifos and resmethrin, in three human breast cell lines. Interestingly, cytotoxicity was not observed in the estrogen-dependent MCF-7 mammary epithelial carcinoma cells; rather increases in cell viability were seen for some of the compounds at select concentrations. These results vary greatly from what was observed in the estrogen independent MDA-MB-231 breast cancer cells and the non-cancerous MCF-10A breast cells. This gives insight into how different tumors may respond to pesticide exposure and allows us to make more accurate conclusions about the potential cytotoxicity or, at times, stimulatory actions of these pesticides.

Heavy Metal Quantification in Renal Tissue of Patients in the State of Yucatan and Its Association with Urolithiasis

Thu, 27 Sep 2012 18:57:28 +0000

A possible cause associated with urinary lithiasis (UL) is the bioaccumulation of heavy metals in the kidney. The aim of this study was to evaluate the content of Cu, Pb, and Cd in kidney tissues removed from patients with nephrological problems and associate it with UL. Samples of 50 kidney sections from patients were analyzed. Results were statistically analyzed using a fixed effects model including the overall mean, the effect of the health status of patients (with or without UL), gender (male and female), the interaction between both factors and the random error . Cu level was mg/kg (mean DS) and 25.5% of samples had levels above normal. Lead content in 97.9% of the samples ( mg/kg) was above normal. All results of Cd ( mg/kg) were below the maximum permissible limits. There was no difference in the amount of heavy metals on patients with or without UL () nor depending on the gender (). It was concluded that there is no apparent relationship between a very elevated level of Cu or Pb in the kidney on the development of UL.

Affinity and Matrix Effects in Measuring Fish Plasma Vitellogenin Using Immunosorbent Assays: Considerations for Aquatic Toxicologists

Stephen E. Bartell and Heiko L. Schoenfuss — Tue, 18 Sep 2012 14:46:41 +0000

Enzyme-linked immunosorbent assays (ELISAs) are important tools in aquatic toxicology and have become crucial in assessing exposure concentrations in the aquatic environment and acute physiological responses in exposed organisms. These assays utilize the inherent properties of antibodies to recognize and selectively bind a target molecule, while largely ignoring other molecules to provide semiquantitative values. A variety of methodologies to measure plasma vitellogenin using ELISAs have generated widely divergent data. Limitations of the ELISA method are known in the wider immunology field, though aquatic toxicologists may be less familiar with these limitations. We evaluated several mechanisms contributing to the divergent vitellogenin data in the literature. Antibody affinities and the matrix in which standard curves are constructed are possible error generators. These errors can be amplified by large sample dilutions necessary to fall within the standard curve. It is important for the aquatic toxicology research community to realize the limitations and understand the pitfalls of absolute plasma vitellogenin data in their studies.

Determination of Aflatoxin in Milk by ELISA Technique in Mashad (Northeast of Iran)

Ali Mohamadi Sani, Mohamad Khezri, and Halime Moradnia — Tue, 11 Sep 2012 14:35:06 +0000

The aim of this study was to detect the amount of aflatoxin M1 (AFM1) in pasteurized milk samples in Mashad in northeast of Iran. For this purpose, 42 milk samples were collected from retail stores during fall 2011 and analyzed for AFM1 by enzyme-linked immunosorbent assay (ELISA) technique. All the analyses were done twice. Results showed presence of AFM1 in 97.6% of the examined milk samples by average concentration of 23 ± 16 ppt and contamination level ranging between 6 and 71 ppt. The concentration of AFM1 in all the samples was lower than the Iranian national standard and Food and Drug Administration limits (500 ppt), and, only in 3 (1.6%) samples, AFM1 concentration was more than the maximum tolerance limit (50 ppt) accepted by European Union and Codex Alimentarius Commission. According to our findings and previous studies, AFM1 contamination of milk is not a concern in this region, and the regional standard of AFM1 contamination in milk might be changed to lower than 100 ppt.

A Review of Use of Enantiomers in Homeopathy

R. M. Kuzeff — Wed, 15 Aug 2012 10:32:23 +0000

This paper reviews publications of laboratory experiments using pairs of enantiomers in homeopathy. Many molecules in nature have geometry which enables them to exist as nonsuperimposable mirror images or enantiomers. Modulation of toxicity of such molecules provides possibility for therapeutics, since they target multiple points in biochemical pathways. It was hypothesized that toxicity of a chemical agent could be counteracted by a homeopathic preparation of the enantiomer of the chemical agent (patents applied for: PCT/AU2003/000219-PCT/AU2008/001611). A diverse body of data, including controlled laboratory studies, supports the conclusion that toxicity of optical isomers may be inhibited by homeopathic enantiomer preparations. These data were obtained with minimal or no pretesting to determine optimal test solutions. Inhibition of the excitotoxic neurotransmitter L-glutamic acid with homeopathic preparations of D-glutamic acid indicates the latter may be of use for amelioration of symptoms of disturbances of mood. Similarly, homeopathic preparation of (+)-nicotine may be of use for inhibition of effects of nicotine in tobacco.

Developmental Neurotoxicity: Some Old and New Issues

Gennaro Giordano and Lucio G. Costa — Sun, 24 Jun 2012 09:32:36 +0000

The developing central nervous system is often more vulnerable to injury than the adult one. Of the almost 200 chemicals known to be neurotoxic, many are developmental neurotoxicants. Exposure to these compounds in utero or during childhood can contribute to a variety of neurodevelopmental and neurological disorders. Two established developmental neurotoxicants, methylmercury and lead, and two classes of chemicals, the polybrominated diphenyl ether flame retardants and the organophosphorus insecticides, which are emerging as potential developmental neurotoxicants, are discussed in this paper. Developmental neurotoxicants may also cause silent damage, which would manifest itself only as the individual ages, and may contribute to neurodegenerative diseases such as Parkinson’s or Alzheimer’s diseases. Guidelines for developmental neurotoxicity testing have been implemented, but there is still room for their improvement and for searching and validating alternative testing approaches.

Herbicide Metolachlor Causes Changes in Reproductive Endocrinology of Male Wistar Rats

Wed, 18 Apr 2012 15:26:49 +0000

S-metolachlor is a chloroacetanilide herbicide widely used in the agriculture to control weeds and was demonstrated that it increases the activity of the aromatase enzyme in cell cultures, which may culminate as endocrine disruption action in vivo. To investigate this hypothesis, prepubertal Wistar male rats were exposed to metolachlor (5 or 50 mg/kg/day, NOEL for reproductive toxicity: 23.5–26.0 mg/kg/day) from PND23 (postnatal day) to PND53. During this period, the growth of the animals and the age and weight at puberty were recorded. In PND53, tissues were collected and the analysis of LH, FSH, testosterone, dihydrotestosterone (DHT), estradiol serum concentrations, morphometric evaluation of the seminiferous epithelium, and weight of the testes and the seminal vesicle (undrained and drained) was performed (Statistical difference: 𝑃<0.05). Metolachlor caused an increase in serum concentrations of testosterone, estradiol, and FSH and a reduction in DHT but did not alter the LH. There were also observed a higher amount of fluid in the seminal vesicles, precocious puberty, and changes in morphology of the seminiferous epithelium of treated animals. We demonstrated in this paper that prepubertal exposure to S-metolachlor caused changes in reproductive endocrinology of male rats.

Evaluation of Eye Irritation Potential of Aqueous Leaf Extract of Achyranthes aspera by In Vitro and In Vivo Method

Tue, 31 Jan 2012 10:01:38 +0000

The present paper is an attempt to investigate the eye irritation potential of aqueous leaf extract of Achyranthes aspera by in vitro, Hen's Egg Chorioallantoic Membrane Test (HET-CAM) and in vivo acute eye irritation test in rabbits. The irritation score (IS) obtained after treatment of the extract on HET-CAM is 0.07 and that of in rabbits is 0.55, Which does not comes under either category 1 or 2 as per the harmonized integrated classification system. The aqueous extract of Achyranthes aspera showed no eye irritation properties both in vitro and in vivo methods when compared with negative control whereas positive controls showed eye irritation potential.

Tissue Distribution and Associated Toxicological Effects of Decabrominated Diphenyl Ether in Subchronically Exposed Male Rats

Fuxin Wang, Jianshe Wang, Guocheng Hu, Xiaojun Luo, Bixian Mai, and Jiayin Dai — Thu, 12 Jan 2012 12:39:28 +0000

Concerns about decabrominated diphenyl ether (BDE-209) have arisen recently due to its increasing concentrations in the environment. We investigated the tissue concentration, distribution, and the debromination of BDE-209 after oral exposure, using rats as a model. Three groups of male rats were administrated by oral gavage with corn oil containing 0, 10, or 50 mg/kg bw/day of BDE-209 over 90 days. After exposure, BDE-209 and its metabolites levels in the liver, kidney, and adipose of the rats were measured. The mRNA expression levels of cytochrome P450 (CYP) enzymes in liver, serum thyroid hormone levels, and open-field tests were also measured. BDE-209 and several octa- and nona-BDE congeners were detected in the tissues of the dosed rats, indicating that BDE-209 was bioavailable and biotransformative in male rats. BDE-209 and its debrominated congeners had no mRNA level effect on selective genes from the CYP family in the liver or on the spontaneous behavior of adult male rats. Conversely, the level of thyroid hormone, total triiodothyronine (T3) in rats from the dosed treatments increased significantly compared to the control group.

Synergistic Cytotoxic Stress and DNA Damage in Clover (Trifolium repens) Exposed to Heavy Metal Soil from Automobile Refining Shops in Kashmir-Himalaya

Towseef Mohsin Bhat, M. Y. K. Ansari, Sana Choudhary, Rumana Aslam, and Alka — Thu, 05 Jan 2012 12:08:04 +0000

Coexposure to heavy metals occurs in many occupational settings, such as automobile refining shops, pigment, and batteries production. Heavy metals around automobile refining shops were tested for their ability to induce synergistic cytogenetic effects in Trifolium repens L. by using the chromosomal aberrasions (CAs), micronucleus (MN) and comet assay. A significant increase in micronucleus (MN), chromosomal abrations (CAs), percentage of nuclei with comet tails (NCTs), the relative comet tail length (CTL), comet tail DNA (CT, DNA), and tail moment (TM) were observed with increased concentration of three heavy metals, like Cd, Pb, Hg. The present result indicate that exposure of T. repens to soils contaminated by heavy metals around automobile refining shops shows clastogenicity, cytotoxicity, and DNA damage at higher concentrations.

In Vivo Effects of Antiviral Protein Kinase C Modulators on Zebrafish Development and Survival

Richard V. Davis, Lisa N. McKernan, Jennifer Rhodes, and Joseph Kulkosky — Tue, 20 Dec 2011 12:49:54 +0000

Clinical interventions using protein kinase C (PKC) modulators have been proposed for eradication of HIV-1-infected cellular reservoirs which persist in patients despite prolonged antiretroviral therapy. The effects of some of these agents have not been assessed in a developing vertebrate model. This study examines the developmental and toxicological effects of these compounds on zebrafish embryos and larvae. Treatment of zebrafish through the first week of development with various PKC pathway modulators did not elicit gross physical defects or elevated incidences of death at lower doses. Higher concentrations resulted in rapid death for both later-stage embryos and larvae. Each compound had a threshold dose for lethality. The defined nonlethal doses may be useful toward assessing the effects of modulating PKC activity on zebrafish development. They may further provide some guidance for the potential dosing of PKC modulators in clinical trials toward the goal of HIV-1 reservoir eradication.

Tetrodotoxin Poisoning Due to Pufferfish and Gastropods, and Their Intoxication Mechanism

Tamao Noguchi, Kazue Onuki, and Osamu Arakawa — Wed, 30 Nov 2011 15:06:10 +0000

Marine pufferfish generally contain a large amount of tetrodotoxin (TTX) in their skin and viscera, and have caused many incidences of food poisoning, especially in Japan. Edible species and body tissues of pufferfish, as well as their allowable fishing areas, are therefore clearly stipulated in Japan, but still 2 to 3 people die every year due to pufferfish poisoning. TTX is originally produced by marine bacteria, and pufferfish are intoxicated through the food chain that starts with the bacteria. Pufferfish become nontoxic when fed TTX-free diets in a closed environment in which there is no possible invasion of TTX-bearing organisms. On the other hand, TTX poisoning due to marine snails has recently spread through Japan, China, Taiwan, and Europe. In addition, TTX poisoning of dogs due to the ingestion of sea slugs was recently reported in New Zealand. TTX in these gastropods also seems to be exogenous; carnivorous large snails are intoxicated by eating toxic starfish, and necrophagous small-to-medium snails, the viscera of dead pufferfish after spawning. Close attention must be paid to the geographic expansion and/or diversification of TTX-bearing organisms, and to the sudden occurrence of other forms of TTX poisoning due to their ingestion.

Mad Honey Intoxication: A Case Series of 21 Patients

Hasan Demir, Arzu Denizbasi, and Ozge Onur — Wed, 26 Oct 2011 13:44:32 +0000

Background. The “grayanotoxin (mad honey)” poisoning is not known commonly, there are some case series and case reports in the medical literature about it, especially in Turkey. The aim of this study was to describe the presentation of 21 natural honey intoxication cases and to review the literature. Material and Method. This study is retrospective analysis of twenty one patients who were admitted to the emergency department due to honey poisoning. Results. Median age of 21 patients was 55. The mean length of delay after consumption is 3.4 hrs. Dizziness, weakness, excessive perspiration, nausea-vomiting, and low blood pressure were the most observed symptoms. Mean pulse rate was 56/min. Mean systolic blood pressure was 102 mmHg. The mean length of hospital stay is 14.7 hrs. Patient rhytms on arrival were as follows: 10 patients were in normal sinus rhytm, 7 sinus bradycardia, 3 nodal rhytm, 1 atrial fibrillation. Atropine was given to 18 patients. None of our patients died and all were discharged home without any complication. Discussion. In the emergency setting, poisoning is a clinical state which is very hard to identify. We have to keep in mind that drugs and toxins may cause lethal dysrhythmias.

Toxicology Evaluation of Realgar-Containing Niu-Huang-Jie-Du Pian as Compared to Arsenicals in Cell Cultures and in Mice

Jia-Wei Miao, Shi-Xia Liang, Qin Wu, Jie Liu, and An-Sheng Sun — Thu, 13 Oct 2011 13:12:41 +0000

Niu-Huang-Jie-Du Pian (NHJD) is a widely used traditional Chinese medicine containing realgar (As4S4). Realgar has been included in many traditional medicines, but is often taken as arsenite for risk assessment. To evaluate true risk of realgar and realgar-containing NHJD, their toxicity was compared with common arsenicals. In cultured cells, the LC50 for NHJD (1200 μM) and realgar (2000 μM) was much higher than arsenite(35 μM), arsenic trioxide (280 μM), and arsenate (400 μM). Acute toxicity in mice showed more severe liver and kidney injury after arsenite or arsenate, but was mild after realgar and NHJD, corresponding to cellular and tissue arsenic accumulation. The expressions of arsenic-sensitive stress gene metallothionein-1 were increased 3–7-folds after arsenite or arsenate, but were unaltered after NHJD and realgar. Thus, realgar and NHJD are much less toxic than arsenite and arsenate. The use of total arsenic to evaluate the safety of realgar and realgar-containing NHJD is inappropriate.

A Review of the Predictive Role of Plasma D-Lactate Level in Acute Appendicitis: A Myth or Truth?

Pinar Unverir and Ozgur Karcioglu — Wed, 12 Oct 2011 08:37:19 +0000

Acute appendicitis (AA) is a common condition which warrants emergency surgery. Detailed history, physical exam, and laboratory findings are often nonspecific in suspected patients. There is substantial evidence to indicate that plasma levels of D-lactate were useful to establish a diagnosis of AA in the medical literature. It has been suggested that it is useful for patients with abdominal pain, especially patients with perforated AA. This paper is designed to highlight the value of D-lactate biomarker in establishing a diagnosis of AA. Based on the literature, it is not helpful for a decision of operation in patients with AA. According to the results of the studies, laboratory involvement was observed between plasma D-lactate level and the final diagnosis of AA, particularly in perforated appendices. It can be considered for routine use in patients with undifferentiated abdominal pain in the emergency department setting.

Can Diabetes I and Early Blindness Be Prevented Using a Tylenol Combination Which Inhibits Oxidative and Nitrosative Stress?

Wed, 05 Oct 2011 09:38:51 +0000

Since oxidative/nitrosative stress cause diabetes, can we prevent this chemistry generating the disease? Streptozotocin causes diabetes by entering the pancreatic beta cell generating excessive nitric oxide which reacts with oxygen creating a toxin possibly peroxynitrite, dinitrogen trioxide, dinitrogen tetraoxide and so forth. The toxic compounds damage the DNA causing beta cell death. This prevents insulin synthesis, storage and release. By using antioxidant substances that destroy the nitric-oxide-based toxins (e.g., carboxy-PTIO (oxidizes nitric oxide), polyphenolic-quercetin and monophenolic acetaminophen (Tylenol)) which are oxidation and nitration targets can the diabetes I causing toxins in animals be destroyed? Will this tri-drug combination completely prevent the deleterious effects of diabetes namely poor blood glucose control and blindness from cataracts for the entire length of the experiment (one year). These disease reversal experiments were accomplished in rats where the streptozotocin-diabetic effects were completely thwarted. In vitro experiments were accomplished to provide the scientific basis for the experimental results in animals.

Analysis of Ammonia Toxicity in Landfill Leachates

Wed, 28 Sep 2011 13:41:13 +0000

Toxicity identification evaluation (TIE) phase I manipulations and toxicity test with D. magna were conducted on leachates from an industrial waste landfill site in Japan. Physicochemical analysis detected heavy metals at concentrations insufficient to account for the observed acute toxicity. The graduated pH and aeration manipulations identified the prominent toxicity of ammonia. Based on joint toxicity with additive effects of unionized ammonia and ammonium ions, the unionized ammonia toxicity (LC50,NH3(aq)) was calculated as 3.3 ppm, and the toxicity of ammonium ions (LC50,NH4+) was calculated as 222 ppm. Then, the contribution of ammonia toxicity in the landfill leachate toxicity was calculated as 58.7 vol% of the total toxicity in the landfill leachate. Other specific toxicants masked by ammonia's toxicity were detected. Contribution rate of the toxicants other than by ammonia was 41.3 vol% of the total toxicity of the landfill leachate.

Speciation of Chromium in Soil and Sludge in the Surrounding Tannery Region, Ranipet, Tamil Nadu

Badal Kumar Mandal, Raviraj Vankayala, and L. Uday Kumar — Wed, 28 Sep 2011 11:58:16 +0000

The distribution and mobility of chromium in the soils and sludge surrounding a tannery waste dumping area was investigated to evaluate its vertical and lateral movement of operational speciation which was determined in six steps to fractionate the material in the soil and sludge into (i) water soluble, (ii) exchangeable, (iii) carbonate bound, (iv) reducible, (v) oxidizable, and (vi) residual phases. The present study shows that about 63.7% of total chromium is mobilisable, and 36.3% of total chromium is nonbioavailable in soil, whereas about 30.2% of total chromium is mobilisable, and 69.8% of total chromium is non-bioavailable in sludge. In contaminated sites the concentration of chromium was found to be higher in the reducible phase in soils (31.3%) and oxidisable phases in sludge (56.3%) which act as the scavenger of chromium in polluted soils. These results also indicate that iron and manganese rich soil can hold chromium that will be bioavailable to plants and biota. Thus, results of this study can indicate the status of bioavailable of chromium in this area, using sequential extraction technique. So a suitable and proper management of handling tannery sludge in the said area will be urgently needed to the surrounding environment as well as ecosystems.