Evidence for cometabolic transformation of weathered toxaphene under aerobic conditions using camphor as a co-substrate

AIMS

Toxaphene is a persistent organic pollutant, composed of approximately 1000 highly chlorinated bicyclic terpenes. The purpose of this study was to evaluate if camphor, a structural analogue of toxaphene, could stimulate aerobic biotransformation of weathered toxaphene.

METHODS AND RESULTS

Two enrichment cultures that degrade camphor as the sole carbon source were established from contaminated soil and biosolids. These cultures were used to evaluate aerobic transformation of weathered toxaphene. Only the biosolids culture could transform compounds of technical toxaphene (CTTs) in the presence of camphor, while no transformation was observed in the presence of glucose or with toxaphene as a sole carbon source. The transformed toxaphene had lower concentration of CTTs with longer retention times, and higher concentration of compounds with lower retention times. Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) showed that aerobic biotransformation mainly occurred with Cl₈ - and Cl₉ -CTTs compounds. The patterns of Cl₆ - and Cl₇ -CTTs were also simplified albeit to a much lesser extent. Seven camphor-degrading bacteria were isolated from the enrichment culture but none of them could degrade toxaphene.

CONCLUSION

Camphor degrading culture can aerobically transform CCTs via reductive pathway probably by co-metabolism using camphor as a co-substrate.

SIGNIFICANCE AND IMPACT OF THE STUDY

Since camphor is naturally produced by different plants, this study suggests that stimulation of aerobic transformation of toxaphene may occur in nature. Moreover plants, which produce camphor or similar compounds, might be used in bioremediation of contaminated soils.

Chlorinated paraffins (CPs) in salmon sold in southern Germany: Concentrations, homologue patterns and relation to other persistent organic pollutants

Chlorinated paraffins (CPs) are complex mixtures of persistent contaminants present throughout the aquatic food web. In this study 122 farmed and 11 wild salmon samples were collected over the course of four years (2014-2017). The ratio of short-chain CP and medium-chain CP and the corresponding homologue patterns were determined by means of gas chromatography (GC) with high resolution, accurate mass Orbitrap mass spectrometry (MS) technology. Characteristic patterns were observed, enabling differentiation between European and non-European (Chilean) samples. Concentration ranges of short-chain CPs (0.97-170 ng/g ww) and medium-chain CPs (1.1-79 ng/g ww) were similarly widespread over three orders of magnitude. Yet, both the mean and median concentrations of MCCPs were usually higher than those of the SCCP. CP levels were generally higher than those of marker polychlorinated biphenyls (PCBs) and hexabromocyclododecanes (HBCDDs). An age- and gender-dependent estimated intake range of 4.6-35 ng/kg bw/week for short and medium-chain CPs via the consumption of salmon was calculated for adults in Germany.

Occurrence of halogenated natural products in highly consumed fish from polluted and unpolluted tropical bays in SE Brazil

Natural compounds from the metabolism of marine organisms have been detected at high concentrations in environmental samples which are not the producers of these compounds. These natural substances are known as halogenated natural products (HNPs). HNPs are possibly toxic halogenated compounds analogous to POPs that may bioaccumulate and biomagnify along the food web and pose a further risk to human and environmental health. The present study analyzed the occurrence of HNPs in the edible muscle of the three most consumed commercial fish species in the state of Rio de Janeiro: sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri) and mullet (Mugil liza) from the highly polluted Guanabara Bay (GB) and the less polluted Ilha Grande Bay (IGB). The analytical steps included Soxhlet extraction, clean-up step and injection in a gas chromatography system coupled to a mass spectrometer operated in the electron-capture negative ion mode (GC/ECNI-MS). The compounds 2,4,6-TBP, 2,4,6-TBA, MHC-1, Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 were found in the analyzed fish from both studied areas. Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 showed the highest concentrations in samples. Q1 concentrations in the sardines from IGB were higher than the sardines from GB (p < 0.05) and higher than the other IGB species (p < 0.05). The differences found among the species may be related to their characteristic habitat and diet. It is noteworthy that most of these compounds do not have any toxicological reference value. Moreover, the HNPs are being detected in species of low trophic level and since this study has worked only with commercial species, these fish may be considered as a source for human exposure to these natural compounds.

Heparin-Coated Left Heart Bypass: Renal Function and Hormonal Response

The effect of partial (50 mI/min/kg) left heart bypass (LHBP) on renal function, plasma renin activity (PRA), aldosterone, arginine vasopressin and atrial natriuretic peptide (ANP) response was studied in ten anesthetized, open-chested mongrel dogs (weight 23-50 kg) over a period of 6 h. Standard equipment with systemic heparinization (control), initially 300 IU/kg, was employed in five dogs, and heparin-coated equipment without additional heparin in the other five (heparin coated). Urine was continuously collected through a transurethral catheter. Urine samples and pulmonary artery blood samples for hormonal assays were taken at preset intervals before and during LHBP. The results in each group were summarized as median (25th-75th) and compared using the Mann-Whitney U test. In the control group higher blood loss required higher volume substitution. Urine output was maintained in heparin coated and slightly decreased at 3-4 h in control LHBP. Creatinine clearance at 3-5 h and free-water clearance at 3-6 h were significantly higher with heparin-coated LHBP. PRA, aldosterone and vasopressin peaked at 1-2 h of LHBP similarly in both groups, not exceeding the values before perfusion. PRA and aldosterone response was sustained during 6 h and the percentage changes corrected for hemodilution indicated a stronger response with standard equipment. Vasopressin concentrations were slightly but significantly higher in the control group at 1 and 6 h of perfusion. Corrected for hemodilution, vasopressin percentage changes were not different in the two groups. ANP, despite atrial unloading, rose similarly in both groups. There was a tendency to poorly sustained ANP response (control > heparin-coated) after 6 h of perfusion. In conclusion, preserved renal function and attenuated hormonal response during canine partial LHBP are results of better hemostasis and circulatory integrity of perfusion without systemic heparinization.

131I-Metaiodobenzylguanidine – A New Agent for Scintigraphic Imaging and Treatment of Pheochromocytoma

In 91 patients with a suspicion of pheochromocytoma 96 scintigraphies with 131I-metaiodobenzylguanidine were performed. The distribution of this radiopharmaceutical agent was studied. In about 71% we found uptake in the liver, in about 20% in the spleen and in about 6% in the gastrointestinal tract. In 13% of our patients a normal tracer uptake in the adrenal medulla was observed. In 23 patients adrenal or extra-adrenal lesion (s) were localized correctly, whereas one false-positive and one false-negative scintigramme was obtained. The 131I-MIBG imaging of adrenal and extra-adrenal, benign and malignant pheochromocytomas and adrenomedullary hyperplasia is highly specific. In the treatment of pheochromocytomas more experience is needed to present final results, but especially in malignant pheochromocytomas 131I-MIBG therapy may be useful.

Halogenated Natural Products in Dolphins: Brain-Blubber Distribution and Comparison with Halogenated Flame Retardants

Halogenated natural products (MHC-1, TriBHD, TetraBHD, MeO-PBDEs, Q1, and related PMBPs) and halogenated flame retardants (PBDEs, HBB, Dec 602, Dec 603, and DP) in blubber and brain are reported from five Alboran Sea delphinids (Spain). Both HNPs and HFRs were detected in brain, implying that they are able to surpass the blood-brain barrier and reach the brain, which represents a new finding for some compounds, such as Q1 and PMBPs, MHC-1, TriBHD, TetraBHD, or Dec 603. Moreover, some compounds (TetraBHD, BDE-153, or HBB) presented higher levels in brain than in blubber. This study evidence the high concentrations of HNPs in the marine environment, especially in top predators. It shows the importance of further monitoring these natural compounds and evaluating their potential toxicity, when most studies focus on anthropogenic compounds only. While no bioaccumulation was found for ∑HNPs, ∑HFRs increased significantly with body size for both common and striped dolphins. Studies evaluating BBB permeation mechanisms of these compounds together with their potential neurotoxic effects in dolphins are recommended.

Concentration of three branched-chain fatty acids in adipose tissue does not affect meat sensory traits in crossbred and purebred German "Merinolandschaf" lambs

Abstract. Intense sheep odour and flavour in lamb is often associated with lower consumer acceptance. Branched-chain fatty acids (BCFAs) are suggested as possible reasons. Therefore, muscle and subcutaneous adipose tissue samples of 98 lamb chops were analysed for three BCFAs (4-methyloctanoic, 4-ethyloctanoic and 4-methylnonanoic fatty acid). Samples were derived from a previous study, in which lambs were raised and fattened under intensive conditions and tested for sensory quality. BCFA contents of fat extracts from muscle tissue were very low and quantification was not possible. In subcutaneous adipose tissue different concentrations of BCFA and differences between crosses were detected. The sex of lambs had a significant influence. The BCFA correlations were significant, while correlations between BCFA of adipose tissue and sensory traits were not significant. Therefore, it seems likely that BCFA concentrations were too low and/or other substances are involved in causing the lamb flavour detected through sensory analysis.

Persistent organohalogen contaminant burdens in Antarctic krill (Euphausia superba) from the eastern Antarctic sector: a baseline study

A baseline for persistent organohalogen compound (POC) accumulation in the Antarctic keystone species, Antarctic krill (Euphausia superba) has been established for a 50 degrees longitudinal range of the eastern Antarctic sector. Samples of adult krill, caught from 12 sites distributed between 30 degrees and 80 degrees E (60-70 degrees S), were analysed for >100 organohalogen compounds including chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated organic compounds and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). Organochlorine pesticides dominated measured krill contaminant burdens with hexachlorobenzene (HCB) as the single most abundant compound quantified. Krill HCB concentrations were comparable to those detected at this trophic level in both the Arctic and temperate northwest Atlantic, lending support for the hypothesis that HCB will approach global equilibrium at a faster rate than other POCs. Para, para'-dichlorodiphenylethene (p,p'-DDE) was detected at notable concentrations. Measurements of DDT and its degradation products provide an important baseline for monitoring the temporal and geographical influence of renewed, DDT usage for malaria-control in affected southern hemisphere countries. In contrast to the Arctic, PCBs did not feature prominently in contaminant burdens of Antarctic krill. The major commercial polybrominated diphenyl ether (PBDE) congeners -99 and -47 were quantified at low background levels with clear concentration spikes observed at around 70 degrees E , in the vicinity of modern, active research stations. The likelihood that local anthropogenic activities are supplementing low PBDE levels, delivered otherwise primarily via long range environmental transport, is discussed. The suspected naturally occurring brominated organic compound, 2,4,6-tribromoanisole (TBA), was a ubiquitous contaminant in all samples whereas the only PCDD/Fs quantifiable were trace levels of octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,7,8/1,2,3,4,7,9-hexachlorodibenzofuran (HxCDF). With the aims of; i) Generating a robust and broadly applicable POC auditing platform for the scarcely studied eastern Antarctic sector; ii) Determining the compounds accumulating in Antarctic krill for further toxicity evaluation studies and iii) Establishing a baseline for Antarctic predator exposure to POCs, this study represents one of the most comprehensive reports of POC contamination of the Antarctic food web to date.

[Prevalence of overweight and obesity in Swiss adolescents]

Overweight and obesity are the most important modulators in the development of chronic diseases. Body weight status in adulthood is often already determined in childhood and adolescence. In this study we evaluate possible threats and the prevalence of overweight and obesity among students of the Kantonsschule Burggraben in St.Gallen. Different anthropometric parameters (e.g. size, weight, circumference of waist and hip, body composition by BIA) were assessed among 552 students and different life-style factors as well as risk factors were assessed with a self-administered questionnaire. Using the IOTF-definitions between 6.12-8.18% of students were overweight and 1.08-2.23% were obese. Male students with the highest media consumption (MC) (around 4 h/d) had a higher BMI (kg/m2) than students with lower MC (around 2 h/d) or the lowest level of MC (approximately 1 h/d) (22.83 +/- 0.46 kg/m2 vs. 21.51 +/- 0.21 kg/m2 and 21.60 +/- 0.39 kg/m2; ANOVA p = 0.008). Similarly body composition was affected: students with the highest media consumption had the highest amount of body-fat mass: 12.69 +/- 0.66% vs. 11.05 +/- 0.34% and 10.69 +/- 0.62% (ANOVA p = 0.026) compared to medium and low MC, respectively. There was no correlation between the BMI, the body fat mass and the MC among female students. According to the level of activity male students with a high level showed a significant lower BMI than students with a lower level of physical activity (21.70 +/- 0.21 kg/m2 vs. 22.05 +/- 0.33 kg/m2; p = 0.016). The body fat mass was also lower for higher levels of physical activity (9.57 +/- 0.65% vs. 12.69 +/- 0.86%). Among female students the level of physical activity modulated the body fat mass (high level 20.66 +/- 0.52% vs. low level 23.53 +/- 0.58; p = 0.005) but had no effect on the BMI. Risk factors for obesity such as physical activity patterns are established in childhood and early adolescence. Preventive strategies have to be implemented as early as possible.

[Epidemiology of over- and underweight in Swiss college students]

Overweight and obesity rates are increasing worldwide. In this study 409 adolescents and young adults (age range 15-22 years) in a Swiss college were studied. The prevalence of overweight was 6.13% in the girls and 5.95% in the boys. 9.52% of the boys and 16.51% of the girls were underweight (BMI < 18.5 kg/m2). 16.98% of the girls had a fat mass > 30%. 2.98% of the boys had a fat mass of > 20%. Male adolescents with a fat mass > 15% judged their physical activity on a visual analogue scale (VAS) significantly lower than male adolescents with a fat mass of < 15% (mean +/- SD VAS score: 4.49 +/- 2.08 vs. 6.00 +/- 2.08, p = 0.03). The same was found in female adolescents: girls with a fat mass > 30% reported a lower physical activity level than females with a fat mass < 30% (mean +/- SD VAS score: 4.84 +/- 1.74 vs. 5.68 +/- 1.82, p = 0.04). Obesity and fatness, but also underweight, is a serious problem in Swiss adolescents. Well chosen public health strategies to address both sides of the energy balance equation are strongly needed.

TNF-alpha -308G>A polymorphism modulates cytokine serum concentrations and macrovascular complications in diabetic patients on aspirin

BACKGROUND

Tumor necrosis factor (TNF)-alpha has pleiotropic effects in cytokine-mediated inflammation underlying atherogenesis. Activation of this inflammatory process is assumed to be different in diabetic and non-diabetic individuals. Previous studies in non-diabetic subjects showed no association between TNF-alpha -308G>A polymorphism and coronary artery disease.

METHODS

Vascular complications and cytokine serum concentrations were assessed as a function of the TNF-alpha -308G>A polymorphism in 76 diabetic patients on low-dose aspirin.

RESULTS

Of 76 adult diabetic patients, 18 (24%) carried the TNF-alpha -308A allele (17 AG, 1 AA) and 58 (76%) carried wild-type alleles (GG). Prevalence of macrovascular complications was 33% in TNF-alpha -308A allele carriers (AG+AA) and 78% in wild-type allele carriers (GG) (p<0.001). In contrast, prevalence of microvascular complications was 78% and 84%, respectively, and did not significantly differ between the study groups. TNF-alpha -308A allele carriers (AG+AA) compared to wild-type allele carriers (GG) had significantly lower median serum concentrations of hs-C-reactive protein (1.5 vs 2.9 mg/L, p=0.030), interleukin 1-beta (0.9 vs 1.2 ng/L, p=0.046), and interleukin-6 (3.6 vs 4.9 ng/L, p=0.023). In multiple regression analysis, the prevalence of macrovascular diabetic complications was significantly associated with TNF-alpha -308G>A polymorphism (p<0.001) and serum concentrations of HDL-cholesterol (p=0.007) while confounding effects of further variables were excluded.

CONCLUSION

TNF-alpha -308G>A polymorphism modulates cytokine serum concentrations and macrovascular complications in diabetic patients on aspirin. Diabetic carriers of the TNF-alpha -308A allele might benefit more from a prophylaxis with low dose aspirin than non-carriers.

[Every step counts: what is the physical activity level of our patients? A pedometer study]

The prevalence of obesity is increaseing worldwide and thus enhancing the development of the chronic diseases. Physical activity represents not only an important modulator of the energy balance but physical exercise represents a key feature for chronic disease risk reduction independently from body weight. In this study we assessed physical activity by counting the steps with the help of a pedometer in 49 consecutive patients (33 women and 16 men) of the obesity- and hypertension clinic at the Medical Policlinic at the University Hospital in Zurich. 29 of the patients were obese (mean +/- SD BMI 35.3 +/- 5.5 kg/m(2)), eleven overweight (27.6 +/- 1.1 kg/m(2)) and eight of normal body weight (22.7 +/- 1.5 kg/m(2)) according to the WHO-classification. The mean +/- SD steps per week of the whole population was 67917 +/- 33856. Patients with a normal weight had more steps per week, but the difference did not reach significance as compared to the overweight or obese subjects. Only on Sunday the normal weighted patients had significantly more steps than the other groups. The data suggest that strategies to enhance physical activity on the weekend should be encouraged in all subjects, especially however in those with an increased body weight.

[Body weight and physical activity: how much is too little? How much is enough?--a study in recreational cyclists]

Body weight and body mass index (BMI) were studied in non professional cyclists. BMI increased from 22.2 +/- 2.3 kg/m2 (20 to 29 y) to 23.8 +/- 1.7 kg/m2 (55 to 77 y) (mean +/- SD). The mean increase per decade was 0.5 kg/m2, markedly less than in the general Swiss population (0.8 to 1.0 kg/m2). Overweight (BMI 25.1-29.9 kg/m2) prevalence increased from 7.4% (20 to 29 y) to 25.5% (55 to 77 y) and obesity (BMI +/- 30.0 kg/m2) was rare (0.2%, n = 1). The amount of sport correlated negatively with BMI change. A high amount of moderate to heavy physical activity (five hours weekly) was required to avoid an increase in BMI. This amount is to high for the general population. Thus, control of energy intake should be advised together with physical activity.

Patient education in asthma: a survey of physicians' knowledge of the principles and implementation of self management in practice

BACKGROUND

Therapeutic patient education, particularly when including written instructions in self-management, improves outcomes in asthma. The education of patients in self-management requires specific knowledge and skills, which are not generally taught in under- or postgraduate training programmes.

PURPOSE

To investigate physicians' knowledge of the principles and implementation of self-management in asthma care.

METHOD

A 14-item questionnaire was developed, piloted and subsequently sent to 1039 general physicians (general practitioners and internists) and pulmonologists registered as members of the Medical Society of Zurich.

RESULTS

368 (35%) of the physicians returned the questionnaire. 352 (96%) stated that they care for patients with asthma, 312 (87%) provided asthma education, 264 (75%) gave information about the mechanisms of illness, 272 (77%) provided instructions on how to use inhalers although only 212 (60%) checked inhaler technique. 170 (48%) instructed patients in home measurement of peak flow recordings (PEFR). 21% of general physicians and 52% of pulmonologists provided written action plans outlining what actions to take if PEFR or symptoms deteriorated. The majority of physicians were aware of positive benefits of patient education and over 80% stated that all asthmatic patients should be offered education. Only 32% felt that they should personally be educating the patients whilst two-thirds expressed a preference for the education to be provided by a specialist centre. 66% of the physicians expressed a desire to undertake further training in effective patient education.

CONCLUSION

Whilst most physicians in this study state to be aware of the benefits of patient education in asthma, only 24% actually provide their patients with asthma self-management plans. With a low response rate, our study is likely to be biased towards those physicians with a greater interest in asthma; hence actual use of self-management plans is likely be lower than in our sample.