Assessing the capacity for compensatory growth in growth-hormone transgenic coho salmon Oncorhynchus kisutch.

The effect of feed cycling (consisting of periods of starvation followed by periods of refeeding to satiation) on compensatory growth was evaluated in growth hormone transgenic and non-transgenic wild-type coho salmon Oncorhynchus kisutch. The specific growth rate (GSR ) of feed-restricted non-transgenic O. kisutch was not significantly different from the GSR of fully-fed non-transgenic O. kisutch during two refeeding periods, whereas the GSR of feed-restricted transgenic O. kisutch was significantly higher in relation to the GSR of fully-fed transgenic O. kisutch during the second refeeding period, but not during the first, indicating that growth compensation mechanisms are different between non-transgenic and growth-hormone (GH)-transgenic O. kisutch and may depend on life history (i.e. previous starvation). Despite the non-significant growth rate compensation in non-transgenic O. kisutch, these fish showed a level of body mass catch-up growth not displayed by transgenic O. kisutch.

No acute effects of an exposure to 50 ppm methyl methacrylate on the upper airways.

PURPOSE: The German MAK value of methyl methacrylate has been fixed at 50 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 50 ppm methyl methacrylate on the upper airways of human subjects. METHODS: Twenty healthy subjects were exposed to 50 ppm methyl methacrylate and to air (sham) in an exposure chamber for 4 h according to a crossover design. Symptoms were assessed by the SPES questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1ß and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1ß, 6 and 8, tumor necrosis factor α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, obtained after exposure. Possible effects were investigated by semiparametric and parametric crossover analyses. RESULTS: The score of the item "irritation to the nose" was slightly elevated following exposure to methyl methacrylate (p ≤ 0.01). Olfactory functioning was not impaired. Mucociliary transport time did not change. Neither concentrations of interleukins in nasal secretions nor mRNA levels were elevated. CONCLUSION: Only minor irritating effects on the nose were observed. The acute exposure to 50 ppm methyl methacrylate did not cause any adverse effects. However, the results cannot be extrapolated to chronic exposure.

Intoxication with a tropenol ester.

BACKGROUND: While the effects of medicinal products are investigated in depth before approval, often very little is known about the intermediates occurring during synthesis. The pharmacological properties of these intermediates can differ substantially from those of the end product. AIMS: To describe a work accident involving intoxication with such an intermediate, tropenol ester. CASE REPORT: A healthy 40-year-old chemical-technical operative erroneously used a scrubbing brush that had just been used to clear up tropenol ester, contaminating his work clothes. Presumably, contact was made with his skin when removing his work clothes later. Shortly thereafter, he developed signs of anticholinergic intoxication with mydriasis, dry mouth, abnormal coordination and later sleepiness and seizures. The patient received intensive medical treatment. Two weeks later, the anticholinergic symptoms had subsided. Qualitative analysis of a urine sample showed traces of tropenol ester. The substance is a muscarinic acetylcholine receptor antagonist. CONCLUSIONS: The clinical symptoms and biomonitoring suggest that intoxication with tropenol ester had occurred, which, as a tertiary amine, readily passes through the blood-brain barrier. The protracted course suggests high affinity for the receptor. Appropriate safety precautions must be taken when handling research substances and intermediates of unknown toxicity.

[Deficits in medical counseling in olfactory dysfunction]. / Defizite der ärztlichen Beratung bei Riechstörungen.

Olfactory dysfunctions are common with a prevalence of up to 20% in the population. An impaired sense of smell can lead to specific dangers, therefore, counseling and warning of hazardous situations to raise patient awareness is an important medical function. In this study 105 patients presenting to the University of Mainz Medical Centre with dysosmia were evaluated using a questionnaire. For quantification of the olfactory dysfunction a standardized olfactory test (Sniffin' Sticks) was used. Of the patients 46% were hyposmic and 40% were functionally anosmic. The median duration of the olfactory impairment was 10 months and the main causes of dysosmia were upper respiratory tract infections and idiopathic disorders. More than 90% of the patients consulted an otorhinolaryngologist and 60% a general practitioner before presenting to the University of Mainz Medical Center. More than two thirds of the patients conducted a professional activity, 95% of patients reported that they had not received any medical counseling and 6% of the subjects were forced to discontinue their profession because of olfactory dysfunction. In patients with olfactory dysfunctions appropriate diagnostics, including olfactometry should be performed. Furthermore, correct medical counseling concerning necessary additional arrangements (e.g. installation of smoke or gas detectors, precautions while cooking or for hygiene) has to be performed. For patients in a profession an analysis of the hazards at work is crucial.

Tissue contaminants and wild fish health in the St. Clair River Area of Concern - Part 2: Spatial trends and temporal declines in organics.

We explored tissue concentrations of polychlorinated biphenyls (PCBs), chlorinated pesticides, and relevant organochlorines and fish health in the following adult wild fish in the St. Clair River Area of Concern (Ontario, Canada): shorthead redhorse (Moxostoma macrolepidotum), yellow perch (Perca flavescens), and emerald shiner (Notropis atherinoides). We collected adult fish from sites within the river's industrial zone (Stag Island), a downstream site adjacent to Walpole Island (Chenal Écarte), and an upstream reference site in Lake Huron in 2002/2003 and 2014. We tested for trends in tissue concentrations of organic contaminants across sites and over time; we assessed the potential effects of contaminants on morphological indicators of fish health across sites by year. Over the 12-year period, the tissue concentrations of most PCBs declined at the river sites, except for some non-legacy PCBs (PCB11 and 185), which increased in yellow perch at Stag Island, a new observation for fish in the St. Clair River AOC. There was little difference between the concentrations of calculated toxic equivalents (TEQs) of the Lake Huron and the St. Clair River fish in 2014, except for emerald shiners from Stag Island which had elevated ΣPCB and TEQs. Each fish species at all sites exceeded the Canadian tissue residue guideline for PCBs for the protection of mammalian wildlife consumers of aquatic biota, but fish-derived TEQs indicated little potential health risk to fish. Over time, hexachlorobutadiene and hexachlorobenzene concentrations increased in some fish at Stag Island by about 8- and 4-fold, respectively, whereas they decreased at other sampling locations. Principal Component Analysis followed by Linear Discriminant Analysis of the 2014 SHRH data suggested that although the fish separated by site, tissue concentrations of PCB and organochlorine contaminants did not have consistent relationships to the morphological health indicators, including egg production in females, which implied the absence of causative relationships.

Effects of an acute exposure to toluene on the DNA repair activity of the human 8-oxoguanine DNA glycosylase 1 (hOGG1) in healthy subjects.

The structure and previous studies on the biotransformation of toluene lead to the suspicion that metabolites may be formed which preferentially react with strongly nucleophilic partners such as sulfhydryl groups of cysteines in proteins. Human 8-oxoguanine DNA glycosylase 1 removes the major oxidative DNA damage and possesses eight cysteines. Its potential inactivation may lead to accumulation of DNA damage by reactive oxygen species formed by exogenous agents or by ubiquitous endogenous processes. The goal of the present investigation was to study the in vivo effect in humans of an acute toluene exposure on hOGG1 activity. Twenty healthy, non-smoking males were exposed to 50 ppm toluene and to filtered air in an exposure chamber for 270 min, using a cross-over design. Before and 30 min after the end of exposure, blood samples were taken and toluene concentrations and the hOGG1 activity were measured. hOGG1 activity was determined in peripheral mononuclear blood cells. Thirty minutes after exposure to toluene, we found a median blood concentration of 0.25 mg toluene/l. Compared with the activity before exposure, upon exposure to toluene a statistically insignificant median increase of hOGG1 activity by +0.4% and upon exposure to air by +2.3% was determined. Thus, no reduction of the hOGG1 repair activity after acute exposure to 50 ppm toluene was observed.

No acute effects of an exposure to 50 ppm acetaldehyde on the upper airways.

OBJECTIVE: German MAK value of acetaldehyde has been fixed at 50 ppm to prevent from irritating effects. The threshold value is mainly based on animal experiments. The aim of this study was to evaluate acute effects of an exposure to 50 ppm acetaldehyde on the upper airways of human subjects. METHODS: Twenty subjects were exposed to 50 ppm acetaldehyde and to air in an exposure chamber for 4 h according to a crossover design. Subjective symptoms were assessed by questionnaire. Olfactory threshold for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1beta and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1beta, 6 and 8, tumour necrosis factor alpha, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, gained after exposure. Possible effects were investigated by semiparametric and parametric crossover analyses. RESULTS: Exposure to acetaldehyde did not cause any subjective irritating symptoms. Olfactory threshold did not change. Mucociliary transport time increased insignificantly after exposure to acetaldehyde. Neither concentrations of interleukins in nasal secretions nor mRNA levels of inflammatory factors were higher after exposure to acetaldehyde. CONCLUSION: An acute exposure to 50 ppm acetaldehyde did not cause any adverse effects in test subjects.

Immunologic findings in workers formerly exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its congeners.

One hundred ninety-two workers in a German pesticide factory who were exposed to polychlorinated dibenzodioxins and -furans (PCDD/PCDF) were investigated for former and present diseases and laboratory changes of the immune system. Moreover, in a subgroup of 29 highly exposed and 28 control persons, proliferation studies were performed. In addition to assays such as blood count, immunoglobulins, serum electrophoresis, monoclonal bands, surface markers, autoantibodies, and lymphocyte proliferation, two new methods, the rise of tetanus antibody concentration after vaccination and the in vitro resistance of lymphocytes to chromate, were used to diagnose the morphologic and functional state of the immune system. There was no stringent correlation of actual PCDD/PCDF concentrations with the occurrence of infections or with one of the immune parameters. In addition, outcomes of the tetanus vaccination and the chromate resistance test were not correlated with PCDD/PCDF. However, the chromate resistance of lymphocytes stimulated by phytohemagglutinin of highly exposed persons was significantly lower than that for the control group. These findings indicate that the function of lymphocytes can be stressed and possibly impaired by high exposure to PCDD/PCDF.

Effects of high doses of toluene on color vision.

High exposure to toluene may cause optic neuropathy and retinopathy, both associated with dyschromatopsia. Another solvent, ethanol, is known to induce acute blue-yellow dyschromatopsia. This study investigated the acute effects of high doses of toluene on color vision. Eight male printshop workers were examined before and after cleaning printing containers with pure toluene. After cleaning, concentrations of toluene in blood were between 3.61 and 7.37 mg/l. Color vision was tested with the Farnsworth panel D-15 test, the Lanthony desaturated panel D-15 test, and the Standard Pseudoisochromatic Plates part 2. For control of possible acute effects, eight workers of a metal-working factory without any neurotoxic exposure were tested according to the same procedure. Acute exposure to toluene did not cause impairment of color vision. However, statistical power is limited due to the small number of exposed subjects. Color vision of the printshop workers tested before cleaning was slightly impaired (statistically not significant) when compared with unexposed subjects.

Saliva as an alternate for blood to measure concentrations of acetone under exposure to isopropanol.

OBJECTIVES: In occupational medicine, blood concentrations are often measured to judge the internal burden of workers at work-place during exposure to a potentially hazardous substance. However, blood-withdrawals are invasive and can often not be taken at work-place due to hygienic reasons. Sampling of saliva is non-invasive and easy to perform even at workplace. In order to substitute blood analysis, analysis of saliva has to be as specific and sensitive as blood investigations. Therefore acetone-concentrations in blood and in saliva during exposure to isopropanol were compared. METHODS: 18 healthy non-smokers were exposed to 360 ppm isopropanol in an exposure chamber over 4 h. Once an hour during exposure and 30 min after, blood and saliva were sampled. Saliva was collected by a cotton plug over 10 minutes and stored in an airtight closed headspace tube. Concentrations of the metabolite acetone were measured by gas chromatography. - RESULTS: The concentrations of acetone in blood and saliva rose continually during exposure and dropped after exposure-cessation. High correlations between concentrations of acetone in blood and saliva were found for each individual and the entire group (entire group: r = 0.8568, p <0.0001, y = 0.8374x - 0.4404). CONCLUSIONS: Acetone-measurement in saliva is a non-invasive, easily conductable and reliable method for estimating the internal burden of isopropanol-exposure. Further studies for the standardization and validation are necessary to impose a threshold limit value on work-place isopropanol-exposure.

Acute effects of 200 ppm 1,1,1-trichloroethane on the human EEG.

OBJECTIVES: Even low concentrations of organic solvents used at work may cause acute effects on the human central nervous system. We investigated the acute effects of 200 ppm 1,1,1-trichloroethane on the human EEG. METHODS: 12 healthy subjects were exposed for 4 hours to 200 ppm and to 20 ppm (control) in an exposure chamber in a cross-over design. EEG was recorded before (reference) and at the end of each exposure with eyes closed and open and during the Color Word Stress test. Spectral power was calculated by Fast Fourier transformation and related to reference values (per cent of baseline). Subjective symptoms and effects of blinding with 20 ppm 1, 1,1-trichloroethane were assessed by questionnaire. RESULTS: Blinding was not effective because of the strong smell of 1,1, 1-trichloroethane. The score for tiredness increased slightly during and after exposure to 200 ppm. In the closed eye condition, the median percentage of spectral power increased at all electrodes of the delta -band, significantly at temporo-occipital leads. In the theta-band, the percentage of the median spectral power was elevated at most of the electrodes but the parietal and some temporal ones. As to the alpha subset1-band, the percentage of the median spectral power was lower at the temporo-parieto-occipital electrodes, yielding significance at T subset4. In the alpha subset2-band, the percentage of the median spectral power was lower at all electrodes, significantly at T subset4 and T subset5. The percentage of the median spectral power of the temporo-parieto-occipital electrodes of the beta subset1 -band was lower during exposure to 200 ppm. There were no clear-cut changes in the beta subset2 -band, in the open eye condition and during the Color Word Stress test. CONCLUSION: The changes in EEG and the increased score for tiredness indicate a slight sedative effect of 200 ppm 1,1,1-trichloroethane.

Lessons learned from Sphingomonas species that degrade abietane triterpenoids.

Abietane terpenoid-degrading organisms include Sphingomonas spp which inhabit natural environments and biological treatment systems. An isolate from the high Arctic indicates that these organisms occur far from trees which synthesize abietanes and suggests that some of these organisms can occupy a niche in hydrocarbon-degrading soil communities. Abietane-degrading Sphingomonas spp provide additional evidence that the phylogeny of this genus is independent of the catabolic capabilities of its members. Studies of Sphingomonas sp DhA-33 demonstrate that biological treatment systems for pulp mill effluents have the potential to mineralize abietane resin acids. On the other hand, these studies indicate that some chlorinated dehydroabietic acids are quite recalcitrant. Strain DhA-33 grows relatively well on some chlorinated dehydroabietic acids but transforms others to stable metabolites. Using strain DhA-33, a novel method was developed to measure the metabolic activity of an individual population within a complex microbial community. Oligonucleotide hybridization probes were used to assay the 16S rRNA:rDNA ratio of DhA-33 as it grew in an activated sludge community. However, this method proved not to be sufficiently sensitive to measure naturally occurring resin acid-degrading populations. We propose that the same approach can be modified to use more sensitive assays.

Acute changes in the EEG of workers exposed to mixtures of organic solvents.

In a pilot study, 11 workers were exposed to mixtures of organic solvents during the cleaning of printing rolls. The exposure was considered as low to moderate. The "electroencephalogram (EEG)" was recorded before and after the cleaning. The spectral power was calculated by Fast Fourier Transformation in six frequency bands. After exposure the spectral power in particular increased in the alpha-1 band and in the temporooccipital leads of the delta band in the closed-eye condition.

Effect of subacute occupational exposure to toluene on color vision.

The subacute effect of toluene on color vision was examined in 59 rotogravure workers exposed to toluene. Toluene and ethanol were determined in blood and color vision testing was performed on Monday before shift and on Friday after shift. The battery included the Ishihara plates, the Velhagen plates, the Standard Pseudoisochromatic Plates part 2, the Farnsworth panel D-15 test, and the Lanthony desaturated panel D-15 test. The concentrations of toluene in blood ranged from < 0.22 to 7.37 mg/l. No effect of toluene on color vision could be observed even in a subgroup of highly exposed workers. So their ability to judge colored products was not impaired.

In vivo ozone exposure does not increase DNA single-strand breaks in human peripheral lymphocytes.

In this randomized parallel study, we examined whether an acute ozone (O3) exposure leads to increased DNA strand breaks in human lymphocytes. The groups were exposed to 0.21 ppm O3 or filtered air for two hours. 30min and 4.5 h after exposure, DNA damage was determined in isolated lymphocytes using the Fast Micromethod. There was no detectable effect after O3 exposure. We conclude that an acute O3 exposure at the tested concentration does not lead to persistent DNA damage.

[Raynaud's phenomenon in occupational vibration exposure]. / Raynaud-Phänomen bei einer beruflichen Vibrationsbelastung.

HISTORY AND ADMISSION FINDINGS: A 34-year-old female stonemason was referred for expert opinion. The question at issue was, whether she suffered from vibration-induced white finger disease. She was exposed to high-frequency hand-arm vibrations for many years. She reported white finger attacks at the long fingers, which were associated with cold weather. Until this point, physical findings were normal. INVESTIGATIONS: The cold water provocation test showed a slight delay of the rewarming for the long fingers of the right hand. The nailfold capillary microscopy was normal. DIAGNOSIS AND COURSE: The slight Raynaud's phenomenon was recognized as an occupational disease with a diagnosis of vibration-induced white finger disease. About three years later, the symptoms of the Raynaud's phenomenon had deteriorated, although the patient had finished working with vibrating tools. The cold water provocation test confirmed the deterioration. At this time, the patient had inflamed swellings of some joints caused by rheumatoid arthritis. CONCLUSION: The differential diagnosis of a Raynaud's phenomenon should include occupational causes. Occupational history is diagnostically indicative. If an occupational disease is assumed, a report must be filed. With respect to German social law, the deterioration of the Raynaud's phenomenon was caused by the rheumatoid arthritis, which is regarded as independent from the job.

Acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects.

The German MAK value of 1-methoxypropanol-2 has been fixed at 100 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects. Twenty subjects were exposed in a crossover design to 100 ppm 1-methoxypropanol-2 and to air in an exposure chamber for 4h. Subjective symptoms were assessed by questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1ß and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1ß, 6 and 8, tumor necrosis factor α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, obtained after exposure. Possible effects were investigated by semiparametric and parametric cross-over analyses. Subjects did not have any subjective irritating symptoms. The olfactory threshold was slightly elevated following exposure to 1-methoxypropanol-2. Mucociliary transport time did not change. Neither concentrations of interleukins in nasal secretions nor mRNA levels except for interleukin 1ß were higher after exposure to 1-methoxypropanol-2. In conclusion, the acute exposure to 100 ppm 1-methoxypropanol-2 did not cause clear-cut adverse effects in test subjects.

Comparison of subjective olfaction ratings in patients with and without olfactory disorders.

OBJECTIVE: Olfactory dysfunction is common. The reliability of self-assessment tools for smell testing is still controversial. This study aimed to provide new data about the accuracy of olfactory self-assessment compared with a standardised smell test. DESIGN: Prospective, controlled, cohort study of patients with olfactory disorders and healthy controls. SUBJECTS: Ninety-six patients with a smell deficit and 71 controls were asked to rate their sense of smell on a visual analogue scale. Their olfactory abilities were also evaluated with the Sniffin' Sticks tests. RESULTS: The whole cohort showed a significant correlation between visual analogue scale smell scores and Sniffin' Sticks total scores. This correlation was also significant in the patient group, but not in the control group. These results were independent of olfactory deficit aetiology and subject age. CONCLUSION: Self-assessment of olfaction is only a reliable indicator in smell-impaired patients, not in healthy controls. For an accurate assessment of olfaction, reliable, standardised tests are needed.

[Toxic anosmia and rhinitis due to occupational solvent exposure]. / Anosmie und Rhinitis durch eine berufliche Lösungsmittelexposition.

A patient's case report documents the development of anosmia and rhinitis caused by occupational exposure to organic solvents, including tetrahydrofuran, cyclohexanone, acetone and other ketones. Physicians should inquire about possible mucosal irritation or prenarcotic symptoms during exposure. If an occupational disease is assumed, notification must be sent to the Institution for Statutory Accident Insurance and Prevention (Berufsgenossenschaft). Some diseases, for example olfactory disorders due to chemical mixtures, are not included in the German list of occupational diseases. In this case, a special law (Sozialgesetzbuch VII) regulates compensation.