Quantitative relationship between silica exposure and lung cancer mortality in German uranium miners, 1946-2003

Background:

In 1996 and 2009, the International Agency for Research on Cancer classified silica as carcinogenic to humans. The exposure–response relationship between silica and lung cancer risk, however, is still debated. Data from the German uranium miner cohort study were used to further investigate this relationship.

Methods:

The cohort includes 58 677 workers with individual information on occupational exposure to crystalline silica in mg m⁻³-years and the potential confounders radon and arsenic based on a detailed job-exposure matrix. In the follow-up period 1946–2003, 2995 miners died from lung cancer. Internal Poisson regression with stratification by age and calendar year was used to estimate the excess relative risk (ERR) per dust-year. Several models including linear, linear quadratic and spline functions were applied. Detailed adjustment for cumulative radon and arsenic exposure was performed.

Results:

A piecewise linear spline function with a knot at 10 mg m⁻³-years provided the best model fit. After full adjustment for radon and arsenic no increase in risk <10 mg m⁻³-years was observed. Fixing the parameter estimate of the ERR in this range at 0 provided the best model fit with an ERR of 0.061 (95% confidence interval: 0.039, 0.083) >10 mg m⁻³-years.

Conclusion:

The study confirms a positive exposure–response relationship between silica and lung cancer, particularly for high exposures.

An outbreak of Shiga toxin-producing Escherichia coli O104:H4 hemolytic uremic syndrome in Germany: presentation and short-term outcome in children

BACKGROUND

In May and June 2011 the largest known outbreak of hemolytic uremic syndrome (HUS) occurred in northern Germany. Because, quite unusually, a large number of adults was affected and the causative Escherichia coli strain, serotype O104:H4, showed an atypical virulence factor pattern, it was speculated that this outbreak was associated with an aggressive course and an unfavorable prognosis also in children.

METHODS

Retrospective analysis of medical records of 90 children and comparison to previous outbreak and sporadic case series.

RESULTS

Median age was unusually high (11.5 years) compared with that in historical series. Only 1 patient (1.1%) died in the acute phase. Most patients (67/90 [74%]) received supportive care only. Renal replacement therapy was required in 64 of 90 (71%) of the children. Neurological complications, mainly seizures and altered mental stage, were present in 23 of 90 (26%) patients. Ten patients received plasmapheresis, 6 eculizumab, and 7 a combination of both. After a median follow-up of 4 months, renal function normalized in 85 of 90 (94%) patients, whereas 3 patients had chronic kidney disease stage 3 or 4, and 1 patient (1.1%) still requires dialysis. Complete neurological recovery occurred in 18 of 23 patients. Mild to moderate and major residual neurological changes were present in 3 patients and 1 patient, respectively, although all patients were still improving.

CONCLUSIONS

E. coli O104:H4 caused the largest HUS outbreak in children reported in detail to date and most patients received supportive treatment only. Initial morbidity, as well as short-term outcome, due to this pathogen, is comparable to previous pediatric series of Shiga toxin-producing E. coli HUS.

Monitors of the hypnotic component of anesthesia - correlation between bispectral index and cerebral state index

BACKGROUND

The current study examines whether analysis of identical EEG data results in a high correlation coefficient of BIS and CSI values during all anesthetic levels and assesses the concordance of both EEG monitors for displaying the level of anesthesia as defined by the manufacturers.

METHODS

EEG data of 40 patients undergoing elective surgery under general anesthesia with either sevoflurane/remifentanil or propofol/remifentanil were replayed to an EEG player and reanalysed by a BIS A-2000® monitor and a Cerebral State Monitor. Further, research into differences between CSI and BIS index values was performed, e.g., extraction of differences of ≥ 10 and ≥ 20 index points and of the EEG length with differing index values.

RESULTS

The overall correlation coefficient was 0.68 without significant difference between propofol or sevoflurane group. In 51.8% of all recordings, both EEG monitors agreed in their classification of the anesthetic level. The number and length of differing index pairs was influenced by varying time delays of index calculation and different algorithms of index computation.

CONCLUSION

In contrast to previous studies, our current approach combines the following conditions: analysis on basis of identical underlying EEG data from deep to light anesthesia, no guidance of anesthetic administration by one of the EEG-based monitors, avoidance of simultaneous EEG readings and the use of two different anesthetic regimens. Though the result of EEG analysis during anesthesia is similar with both monitors, CSI performance during propofol anesthesia was superior to sevoflurane anesthesia. Consequently, a lower agreement of classification of anesthetic levels between BIS and CSI was reached with the use of sevoflurane. Thus, CSI calculation seems not to be independent from anesthetic agent.

Modification of milk fatty acid composition by feeding forages and agro-industrial byproducts from dry areas to Awassi sheep

The study tested the hypothesis that certain underused forages and agro-industrial byproducts available in dry areas may positively influence fatty acid (FA) composition and antioxidative properties of milk by their contents of residual oil or phenolic compounds or both. Sixty multiparous fat-tailed Awassi ewes were allocated to 6 groups in a completely randomized block design. During 50 d, the ewes were group-fed 2.5 kg of dry matter/d per ewe 1 of 6 isonitrogenous and isoenergetic diets (forage:concentrate, 0.3:0.7). The test feeds, comprising 30% of the diets, replaced either barley straw [lentil straw, olive leaves, and Atriplex (saltbush) leaves, rich in phenolic compounds or electrolytes] or conventional concentrate ingredients (olive cake and tomato pomace; ∼10% lipids) from the control diet. The diets containing olive cake and tomato pomace were rich in oleic acid (18:1 cis-9; 27% of total dietary FA) and linoleic acid (18:2 cis-9,cis-12; 37%), respectively. Profiles of FA were determined in individual milk samples drawn on d 0 and in wk 1, 3, 5 and 7. Data was analyzed by repeated measurement analysis. No consistent treatment effects on yield and gross nutrient composition of the milk were observed, although some differences occurred. Milk resulting from the Atriplex leaf diet expressed the highest antiradical activity, which was low with control and olive leaves. Feeding the tomato pomace and olive cake diets decreased the proportions of short- and medium-chain FA, whereas oleic acid clearly increased in proportion to total FA. Olive leaves most effectively increased rumenic acid (18:2 cis-9,trans-11) and α-linolenic acid (18:3 cis-9,cis-12,cis-15) in milk fat. This also resulted in the highest α-linolenic acid transfer rate from feed to milk and suggests that olive leaves affect ruminal biohydrogenation at several steps. Several alternative feeds exist with an added value, as they enhance FA with potential health benefits and the stability of the milk with higher antioxidative activity, even though responses to test feeds differed largely. It remains to be investigated whether combinations of these feeds would be complementary in these beneficial effects.

Occupational dust and radiation exposure and mortality from stomach cancer among German uranium miners, 1946-2003

OBJECTIVES

'Dusty occupations' and exposure to low-dose radiation have been suggested as potential risk factors for stomach cancer. Data from the German uranium miner cohort study are used to further evaluate this topic.

METHODS

The cohort includes 58 677 miners with complete information on occupational exposure to dust, arsenic and radiation dose based on a detailed job-exposure matrix. A total of 592 stomach cancer deaths occurred in the follow-up period from 1946 to 2003. A Poisson regression model stratified by age and calendar year was used to calculate the excess relative risk (ERR) per unit of cumulative exposure to fine dust or from cumulative absorbed dose to stomach from α or low-LET (low linear energy transfer) radiation. For arsenic exposure, a binary quadratic model was applied.

RESULTS

After adjustment for each of the three other variables, a statistically non-significant linear relationship was observed for absorbed dose from low-LET radiation (ERR/Gy=0.30, 95% CI -1.26 to 1.87), α radiation (ERR/Gy=22.5, 95% CI -26.5 to 71.5) and fine dust (ERR/dust-year=0.0012, 95% CI -0.0020 to 0.0043). The relationship between stomach cancer and arsenic exposure was non-linear with a 2.1-fold higher RR (95% CI 0.9 to 3.3) in the exposure category above 500 compared with 0 dust-years.

CONCLUSION

Positive statistically non-significant relationships between stomach cancer and arsenic dust, fine dust and absorbed dose from α and low-LET radiation were found. Overall, low statistical power due to low doses from radiation and dust are of concern.

Stable carbon isotope composition of perirenal adipose tissue fatty acids from Engadine sheep grazing either mountain or lowland pasture

To provide further insights into ruminant lipid digestion and metabolism, and into cis-9,trans-11 18:2 synthesis, 12 growing Engadine lambs grazing either mountain pasture (2,250 m above sea level; n = 6) or lowland pasture (400 m above sea level; n = 6) were studied. Both pastures consisted exclusively of C(3) plants. Before the experiment, all animals grazed a common pasture for 6 wk. Grasses and perirenal adipose tissues of the sheep were analyzed for fatty acids by gas chromatography. Stable C-isotope ratios (δ(13)C values in ‰ vs. the Vienna Pee Dee Belemnite standard) were determined in the composite samples by elemental analysis-isotope ratio mass spectrometry. The δ(13)C of the individual fatty acids were measured by gas chromatography-combustion-isotope ratio mass spectrometry. The δ(13)C value of the entire mountain pasture grass was -27.5‰ (SD 0.31), whereas that of the lowland pasture grass was -30.0‰ (SD 0.07). This difference was reflected in the perirenal adipose tissues of the corresponding sheep (P < 0.05), even though the δ(13)C values were less in the animals than in the grass. The δ(13)C values for cis-9 16:1 and cis-9 18:1 in perirenal fat differed between mountain and lowland lambs (P < 0.05). The 16:0 in the adipose tissue was enriched in (13)C by 5‰ compared with the dietary 16:0, likely as a result of partly endogenous synthesis. The δ(13)C values of cis-9,trans-11 18:2 (cis-9,trans-11 CLA) in the adipose tissue were smaller than those of its dietary precursors, cis-9,cis-12 18:2 and cis-9,cis-12,cis-15 18:3; conversely, the δ(13)C values of trans-11 18:1 were not, suggesting that large proportions of perirenal cis-9,trans-11 18:2 were of endogenous origin and discrimination against (13)C occurred during Δ(9)-desaturation. The same discrimination was indicated by the isotopic shift between 16:0 and cis-9 16:1 in the mountain grazing group. Furthermore, the δ(13)C values of cis-9,trans-11 18:2 were smaller relative to the precursor fatty acids in the mountain lambs compared with the lowland group. This result suggests a reduced extent of biohydrogenation in lambs grazing on mountain grass in comparison with those grazing on lowland grass. This was supported by the smaller cis-9,trans-11 18:2 concentrations in total fatty acids found in the adipose tissues of the lowland lambs (P < 0.001). The results of this study demonstrate that natural differences between δ(13)C values of swards from different pastures and the adipose tissue fatty acids could be used as tracers in studies of lipid metabolism in ruminants.

Influence of high-altitude grazing on bone metabolism of growing sheep

The objective of this study was to identify the effect of high alpine grazing, associated with varying pasture grass qualities and more pronounced exercise on typically steep slopes, on bone metabolism by improving bone density and enhancing bone turnover in growing sheep. Twenty-four 5-month-old sheep were randomly assigned to two groups. One group was kept at high altitude (HA; 2000-2200 m a.s.l.) for 3 months, and the other group (C; control) remained in the lowlands (400 m a.s.l.). Both groups were kept in grazing pastures with access to good-quality swards. Before the start of the experiment, blood samples were taken, the sheep were weighed, and the left metatarsus of each animal was analysed by quantitative computer tomography. After 1 month, blood samples were taken and body weight was measured, followed by biweekly sampling. Finally, the animals were slaughtered, and the bones were collected for analysis of various bone parameters. Body weight development did not differ between the groups. Concentrations of 25-OH-Vitamin D, carboxy-terminal telopeptide of type I collagen and activities of bone-specific alkaline phosphatase were always higher in the HA group than in the C group, except on the last two sampling dates. Bone mineral content and density increased in both groups during the experiment, but more intensively in the HA group. In addition, the cortical thickness of the HA group increased. The present study demonstrates an increase in bone turnover and mineral content of the bones of the growing sheep grazing in high alpine pastures. The factors associated with HA grazing, therefore, clearly seem to improve bone composition.

The influence of low donor age, living related donation and pre-emptive transplantation on end-organ damage based on arterial hypertension after paediatric kidney transplantation

BACKGROUND

To date, no study has described the pre-transplant and transplant risk factors for end-organ damage based on arterial hypertension in children after kidney transplantation (KTX).

METHODS

A retrospective chart review was performed of 206 children with KTX between 1991 and 2007. Patients<120 cm were excluded as no validated percentiles for 24-h ambulant blood pressure monitoring (ABPM) exist. Complete data sets were available for 116 patients. Data were recorded at 12, 24 and 36 months post- KTX. We analysed the influence of donor age, age at transplantation, pre-emptive transplantation, living or deceased transplantation and glomerular filtration rate (GFR) on the presence of end-organ damage, ABPM, ABPM standard deviation score and the numbers of anti-hypertensives used.

RESULTS

Lower donor age and the decade of transplantation were associated with less detection of end-organ damage (P=0.001). A lower need for anti-hypertensive medication (P=0.001) was detected in children who received organs from living donors and from deceased donors with a donor age<35 years and who were transplanted pre-emptively. Low recipient age was the only factor associated with lower ABPM (P=0.001). In our study, the type of immunosuppressive regimen and the GFR had no influence on the blood pressure.

CONCLUSIONS

It may be speculated that the risk of arterial hypertension and associated end-organ damage in children after KTX could be reduced by using organs from young donors with an advantage for living related and pre-emptive donation.

BioRef: a versatile time-of-flight reflectometer for soft matter applications at Helmholtz-Zentrum Berlin

BioRef is a versatile novel time-of-flight reflectometer featuring a sample environment for in situ infrared spectroscopy at the reactor neutron source BER II of the Helmholtz Zentrum Berlin für Materialien und Energie (HZB). After two years of design and construction phase the instrument has recently undergone commissioning and is now available for specular and off-specular neutron reflectivity measurements. BioRef is especially dedicated to the investigation of soft matter systems and studies at the solid-liquid interface. Due to flexible resolution modes and variable addressable wavelength bands that allow for focusing onto a selected scattering vector range, BioRef enables a broad range of surface and interface investigations and even kinetic studies with subsecond time resolution. The instrumental settings can be tailored to the specific requirements of a wide range of applications. The performance is demonstrated by several reference measurements, and the unique option of in situ on-board infrared spectroscopy is illustrated by the example of a phase transition study in a lipid multilayer film.

In vitro evidence for the importance of cultivation conditions on the effects of Calliandra tannins on ruminal escape of soybean protein and its post-ruminal degradability

Purified condensed tannins (CT) extracted from the legume Calliandra calothyrsus (var. San Ramón CIAT 22310), harvested in the dry and the rainy season and cultivated with low or high level of fertilization were added to soybean meal in a ratio of 600 mg/g of the incubated crude protein (CP). Effects on degradation either in ruminal fluid only, or in ruminal fluid followed by incubation in HCl/pepsin, were evaluated using a modified two-step in vitro method. Season was found to have larger effects on in vitro ruminal and post-ruminal CP degradation than fertilization. Condensed tannins from the rainy season harvest reduced ruminal CP degradation less than that from the dry season harvest. They had also less negative effects on the degradability of rumen escape protein and enhanced the proportion of post-ruminally degraded CP more than CT from the dry season harvest. An increase in level of fertilization reduced ruminal CP degradation in CT from the rainy season plants but this was not associated with effects on post-ruminal degradation. The study demonstrated the importance of environmental factors for the efficiency of CT in modifying ruminal and post-ruminal CP degradation.