A Perspective on the Toxicity of Low Concentrations of Petroleum-Derived Polycyclic Aromatic Hydrocarbons to Early Life Stages of Herring and Salmon

This article presents a critical review of two groups of studies that reported adverse effects to salmon and herring eggs and fry from exposure to 1 μg/L or less of aqueous total polycyclic aromatic hydrocarbons (TPAH), as weathered oil, and a more toxic aqueous extract of “very weathered oil.” Exposure media were prepared by continuously flowing water up through vertical columns containing gravel oiled at different concentrations of Prudhoe Bay crude oil. Uncontrolled variables associated with the use of the oiled gravel columns included time- and treatment-dependent variations in the PAH concentration and composition in the exposure water, unexplored toxicity from other oil constituents/degradation products, potential toxicity from bacterial and fungal activity, oil droplets as a potential contaminant source, inherent differences between control and exposed embryo populations, and water flow rate differences. Based on a review of the evidence from published project reports, peer-reviewed publications, chemistry data in a public database, and unpublished reports and laboratory records, the reviewed studies did not establish consistent dose (concentration) response or causality and thus do not demonstrate that dissolved PAH alone from the weathered oil resulted in the claimed effects on fish embryos at low μg/L TPAH concentrations. Accordingly, these studies should not be relied on for management decision-making, when assessing the risk of very low–level PAH exposures to early life stages of fish

9. Management of captive animals

Husbandry interventions for captive breeding amphibians Expert assessors Kay Bradfield, Perth Zoo, Australia Jeff Dawson, Durrell Wildlife Conservation Trust, UK Devin Edmonds, Association Mitsinjo, Madagascar Jonathan Kolby, Honduras Amphibian Rescue and Conservation Center, Honduras Stephanie Jayson, Veterinary Department, Zoological Society of London, UK Daniel Nicholson, Queen Mary University of London, UK Silviu O. Petrovan, Cambridge University, UK and Froglife Trust, UK Jay Redbond, Wi..

Use of horseradish peroxidase for gene-directed enzyme prodrug therapy with paracetamol

Gene therapy is a potential method of treating cancer with a greater degree of targeting than conventional therapies. In addition, therapy can be directed towards cells within the tumour population that are traditionally resistant to current treatment schedules. Horseradish peroxidase (HRP) can oxidise paracetamol to N-acetyl-p-benzoquinoneimine via a one-electron pathway. Incubation of human cells expressing HRP with 0.5–10 mm paracetamol reduced clonogenic survival, but had little effect on control cells. A small increase in apoptosis was seen and a decrease in the number of cells undergoing mitosis, consistent with reports in hepatocytes using higher paracetamol concentrations. The cytotoxicity was also seen under conditions of severe hypoxia (catalyst induced anoxia), indicating that the HRP/paracetamol combination may be suitable for hypoxia-targeted gene therapy

Nanogrids and Beehive-Like Nanostructures Formed by Plasma Etching the Self-Organized SiGe Islands

A lithography-free method for fabricating the nanogrids and quasi-beehive nanostructures on Si substrates is developed. It combines sequential treatments of thermal annealing with reactive ion etching (RIE) on SiGe thin films grown on (100)-Si substrates. The SiGe thin films deposited by ultrahigh vacuum chemical vapor deposition form self-assembled nanoislands via the strain-induced surface roughening (Asaro-Tiller-Grinfeld instability) during thermal annealing, which, in turn, serve as patterned sacrifice regions for subsequent RIE process carried out for fabricating nanogrids and beehive-like nanostructures on Si substrates. The scanning electron microscopy and atomic force microscopy observations confirmed that the resultant pattern of the obtained structures can be manipulated by tuning the treatment conditions, suggesting an interesting alternative route of producing self-organized nanostructures

Altered Metabolism of Growth Hormone Receptor Mutant Mice: A Combined NMR Metabonomics and Microarray Study

Growth hormone is an important regulator of post-natal growth and metabolism. We have investigated the metabolic consequences of altered growth hormone signaling in mutant mice that have truncations at position 569 and 391 of the intracellular domain of the growth hormone receptor, and thus exhibit either low (around 30% maximum) or no growth hormone-dependent STATS signaling respectively. These mutants result in altered liver metabolism, obesity and insulin resistance

Human Health Risk Assessment For Arsenic: A Critical Review

Millions of people are exposed to arsenic resulting in a range of health implications.This paper provides an up-to-date review of the different sources of arsenic (water, soil and food), indicators of human exposure (biomarker assessment of hair, nail, urine and blood), epidemiological and toxicological studies on carcinogenic and non-carcinogenic health outcomes, and risk assessment approaches. The review demonstrates a need for more work evaluating the risks of different arsenic species such as; arsenate, arsenite monomethylarsonic acid, monomethylarsonous acid, dimethylarsinic acid and dimethylarsinous acid as well as a need to better integrate the different exposure sources in risk assessments

Dinamika funkcije pluća kod azbestne bolesti

As a rule, asbestosis is a disease of workers who are occupationally exposed to inhalation of asbestos dust, leaving permanent alterations on the lung parenchyma or pleura. In our ten-year study, we investigated 318 workers with pleural asbestosis from whom we took medical history which included occupational exposure to asbestos, radiological examinations and lung function, which is mandatory for the diagnosis and the follow up of the disease. We analysed functional parameters such as forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) and intermediate forced expiratory flow at 25 % to 75 % (FEF25 %-75 %). In addition, we investigated the predicted values of functional parameters according to smoking and non-smoking habits. We found a significant reduction in vital capacity, particularly in smokers after 25 years of exposure to asbestos. During the first 15 years, values of vital capacity on the group basis remained inside the 80 % of the normal values and were not significant for assessing the dynamics of the lung function. To better assess the effects of occupational asbestos exposure, it is necessary to interpret lung function data not only on the group basis, but also for each subject individually.Azbestoza je bolest izazvana udisanjem azbestnih čestica koje ostavljaju trajne promjene na parenhimu pluća i/ili pleuri. Dijagnoza se postavlja na osnovi anamnestičkih podataka, uvidom u profesionalnu izloženost azbestu i radiološkom obradom te patohistološkom potvrdom promjena na plućima i/ili pleuri. Funkcionalna obrada pluća obavezna je u postavljanju dijagnoze i praćenju bolesti. Tijekom desetogodišnjeg istraživanja funkcionalno smo obradili 318 osoba profesionalno izloženih azbestu s dokazanom azbestozom pleure. Analizirane su vrijednosti funkcionalnih parametara, i to forsiranoga vitalnog kapaciteta (FVC), forsiranoga ekspiracijskog volumena u prvoj sekundi (FEV1) i srednjega ekspiracijskog protoka (FEF25 %-75 %). Dokazan je statistički signifikantan pad vrijednosti FVC i FEV1. Dodatno smo istražili vrijednosti funkcionalnih parametara kod naših ispitanika s navikom pušenja i nepušača. U obje skupine prisutno je značajno sniženje vrijednosti vitalnog kapaciteta tijekom istraživanja, s tim da nakon 25 godina izloženosti azbestu kod pušača dolazi do naglog pada vrijednosti vitalnog kapaciteta u odnosu na nepušače. Bitno je uočiti da tijekom prvih 15 godina vrijednosti vitalnog kapaciteta ostaju unutar 80 % normalnih vrijednosti te nemaju značenja za praćenje dinamike funkcije pluća kod azbestne bolesti. Individualnim praćenjem profesionalno izloženih radnika ostvaruje se bolji uvid u dinamiku funkcije pluća kod azbestne bolesti