Influence of steel implant surface microtopography on soft and hard tissue integration.

After implantation of an internal fracture fixation device, blood contacts the surface, followed by protein adsorption, resulting in either soft-tissue adhesion or matrix adhesion and mineralization. Without protein adsorption and cell adhesion under the presence of micro-motion, fibrous capsule formation can occur, often surrounding a liquid filled void at the implant-tissue interface. Clinically, fibrous capsule formation is more prevalent with electropolished stainless steel (EPSS) plates than with current commercially pure titanium (cpTi) plates. We hypothesize that this is due to lack of micro-discontinuities on the standard EPSS plates. To test our hypothesis, four EPSS experimental surfaces with varying microtopographies were produced and characterized for morphology using the scanning electron microscope, quantitative roughness analysis using laser profilometry and chemical analysis using X-ray photoelectron spectroscopy. Clinically used EPSS (smooth) and cpTi (microrough) were included as controls. Six plates of each type were randomly implanted, one on both the left and right intact tibia of 18 white New Zealand rabbits for 12 weeks, to allow for a surface interface study. The results demonstrate that the micro-discontinuities on the upper surface of internal steel fixation plates reduced the presence of liquid filled voids within soft-tissue capsules. The micro-discontinuities on the plate under-surface increased bony integration without the presence of fibrous tissue interface. These results support the hypothesis that the fibrous capsule and the liquid filled void formation occurs mainly due to lack of micro-discontinuities on the polished smooth steel plates and that bony integration is increased to surfaces with higher amounts of micro-discontinuities. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 705-715, 2018.

Transfer of the fungicide vinclozolin from treated to untreated plants via volatilization.

Head lettuce plantlets (Lactuca sativa L. var. capitata) were potted, treated with vinclozolin at the six-leaf stage according to application standards and allowed to dry for 24 h. The potted plantlets were then placed in either growth chambers with controlled temperature (20 and 25 degrees C, respectively) or in a greenhouse (approximately 12 degrees C), together with untreated spinach (Spinacia oleracea L.) and standardized grass cultures (Lolium multiflorum Lam. ssp.) While the treated lettuce pots remained in the respective growing compartments until the end of the experiments, spinach and grass were exposed to the compartment air for 24 h and their shoot material was analyzed for vinclozolin by GC-ECD and GC-high resolution mass spectrometry. Exposure and analysis of untreated spinach and grass were carried out at two- or three-day intervals during the course of the experiments. Also, air samples were taken from the compartments at intervals and analyzed for vinclozolin. Maximum vinclozolin concentration in the growth chamber air was about 330 ng m(-3) while vinclozolin contamination of the untreated plants ranged from 50 to 200 microg kg(-1) FW (fresh weight). In the greenhouse atmospheric vinclozolin concentration reached approximately 15 ngm(-3) and maximum contamination of spinach and grass were 30-40 microg kg(-1) FW. Our data clearly show that unintended contamination of plants growing in the vicinity of vinclozolin-treated plants can occur even if the fungicide layer is completely dry. Implications for safety testing and food plants are discussed.

Behaviour and ecotoxicology of aluminium in soil and water--review of the scientific literature.

The scientific literature on chemical and biological behaviour of aluminium products and aluminium compounds following exposure to environmental media is considered. Although many studies have been performed on corrosion of aluminium products, no precise information exists about the amount of aluminium released by dissolution of the protective layer of aluminium products. Since no data are available on the effect caused by introduction of anthropogenic aluminium into the environment a comparison between aluminium released as a result of human activity and geogenic aluminium is only possible by estimating the extent to which anthropogenic aluminium is released using purely theoretical premises. The important results in the literature about the availability and toxicological effects of metallic aluminium and aluminium compounds are presented. Finally, a general assessment of the environmental compatibility of aluminium products is given.

Seasonal covariation of the circadian phases of rectal temperature and slow wave sleep onset.

There is a scarcity of well-controlled studies of the seasonal variation in circadian rhythmicity. In the present study, the circadian phase of rectal temperature and the onset of slow wave sleep were studied in a series of twelve 24-h experiments, one each month of the year, for six healthy subjects under controlled conditions in a climatic chamber. In winter, as compared with summer, the average circadian rhythm of rectal temperature was phase delayed by 45 min, and the average onset of slow wave sleep was phase delayed by 40 min. The temporal relationship between the circadian phase of rectal temperature and the timing of slow wave sleep was maintained throughout the year. Habitual rising and retiring times covaried as well. Furthermore, the circadian rhythm of rectal temperature followed the timing of the photoperiod across the year, but had a much smaller range of seasonal variation. Apparently, the seasonal variation in the photoperiodic zeitgeber is largely compensated for by the stabilizing influence of secondary zeitgebers. However, in healthy subjects some effect of photoperiodic variation can still be observed.

Differentiation of Al3+ and Al species in environmental samples by isotachophoresis.

An isotachophoretic method for the determination of free [Al(H2O)6]3+ ions in different aluminium salt solutions was developed. The electrolyte system consists of 0.01 M sodium acetate (leading system) and 0.01 M tris(hydroxymethyl)amino-methane (terminating system). Separation was effected with a precapillary tube (diameter 0.05 cm) followed by a main capillary tube of length 20 cm and of smaller cross-section. The detection limit for [Al(H2O)6]3+ ions was 0.05 mg/l. The method was applied to the determination of free Al3+ ions ([Al(H2O)6]3+) in soil leachates and aqueous soil extracts.

Carcinogenicity of sodium dichromate and chromium (VI/III) oxide aerosols inhaled by male Wistar rats.

In inhalation chambers, male Wistar rats of the strain TNO-W74 were continuously exposed to submicron aerosols of sodium dichromate and to a pyrolyzed Cr(VI)/Cr(III) (3:2) oxide mixture. The sodium dichromate (Na2Cr2O7) aerosol had the chromium concentrations of 25, 50 and 100 micrograms/m3, the chromium oxide mixture (Cr5O12) had the chromium concentration of 100 micrograms/m3. After 18 months of inhalation the rats were held under conventional conditions for a further year. The experimental groups consisted of 20 rats and the control group of 40 rats. More than 90% of the rats in each group reached 2 years. At the end of the study the mortality rates amounted to 35%, 45% and 25% in the 3 sodium dichromate aerosol groups, respectively, and 50% in the chromium oxide mixture aerosol group, which was not significantly different from that of the controls (42.5%), living under the same conditions in filtered fresh air. In all sodium dichromate exposed groups significant effects were neither found clinically nor from hematology and clinical chemistry compared to the controls. In the chromium oxide mixture group, however, there was a number of significant findings. Elevated white and red blood cell counts and serum cholesterol as well as decreased serum total immunoglobulin levels at different stages of the study were observed together with few local lung effects determined histopathologically in this group. We assume that these effects are mainly due to the increased chromium lung burden of the rats. At the end of the study the lung chromium retention was about 10 times higher for the rats exposed to chromium oxide versus sodium dichromate at an aerosol Cr-concentration of 100 micrograms/m3, while the kidney chromium retention was measured to be nearly equal in both groups. Three primary lung tumors (2 adenomas and 1 adenocarcinoma) and 1 malign tumor of the pharynx were found at the highest Cr-concentration (100 micrograms/m3) of the sodium dichromate aerosol, 1 primary adenoma of the lung was in the chromium oxide mixture group exposed also to a Cr-concentration of 100 micrograms/m3. No primary lung tumors were observed in the other experimental and control groups. These results indicate a weak carcinogenicity at 100 micrograms/m3 for the rats continuously exposed to submicron Na2Cr2O7 and Cr5O12 aerosols. Thus, there may be a small carcinogenic risk from occupational relevant chromium air levels. However, results have to be confirmed with larger animal populations.

Bioavailability indicators of inhaled cadmium compounds.

In a thirty-day inhalation study male Wistar rats were continuously exposed to submicron aerosols of three different cadmium compounds. The cadmium chloride (CdCl2) and cadmium oxide (CdO) aerosol concentrations were 0.1 mg/m3 Cd. Because of its lower solubility the cadmium sulfide (CdS) level was 1 mg/m3 Cd. For CdCl2 and CdO, most of the cadmium was found in the lung cytosolic compartment, but for CdS only 30% of the cadmium was retrieved from the lung cytosols. This was observed both at the end of the inhalation and also after an additional 2-month period in fresh air. The cadmium contents of the lung homogenates, cytosols, and the lung cytosolic metallothionein were found to be twice as much for exposure to CdO than for exposure to CdCl2. For exposure to CdS at cadmium concentrations 10 times higher the same cadmium levels were found as for CdO. These results are confirmed by results from alveolar lavage analysis indicating that in the lung-inhaled CdO is even more available to lung tissue than the very soluble CdCl2, and CdO has an availability 10 times as much as CdS. This study proved that lung compartmental cadmium and metallothionein contents as well as lung lavage analysis can describe the bioavailability of inhaled cadmium.

Low level chromium (VI) inhalation effects on alveolar macrophages and immune functions in Wistar rats.

In inhalation chambers, 5-week-old male Wistar rats of the strain TNO-W-74 were continuously exposed to submicron aerosols of sodium dichromate in concentrations from 25 (low level) to 200 micrograms/m3 Cr (high level). Subacute exposure (28 days) to 25 and 50 micrograms/m3 Cr resulted in "activated" alveolar macrophages with stimulated phagocytic activities, and significantly elevated antibody responses to injected SRBC's. After subchronic (90 days) low level exposure there was a more pronounced effect on activation of the alveolar macrophages, with increased phagocytic activities. However, at high Cr (VI) exposure level (200 microgram/m3), inhibited phagocytic function of the alveolar macrophages was seen. In rats which were exposed to this chromium aerosol concentration for 42 days, the lung clearance of inert iron oxide was reduced significantly. The humoral immune system was still stimulated at subchronic low chromium aerosol concentrations of 100 micrograms/m3, but significantly depressed at 200 micrograms/m3 Cr. These results show that respiratory defence and immunologic functions were stimulated or inhibited depending on dose and time of chromium (VI) inhalation.

[Metabolism of carbromal during detoxication with combined hemoperfusion and hemodialysis (author's transl)]. / Metabolismus von Carbromal unter der Entgiftung mittels kombinierter Hämoperfusion und Hämodialyse.

Combined charcoal hemoperfusion and hemodialysis was performed on three occasions in two patients with severe carbromal intoxication. The concentration of carbromal, its organic metabolites and of bromide was determined in arterial blood before and after passage of the charcoal column and behind the dialyzer cartridge. Results show a rapid metabolic degradation of carbromal including cleavage of bromide. Besides carbromal and its main metabolite 2-brome-2-ethylbutyramide (=carbromide) debromised organic metabolites appear to be responsible for the severity of the intoxication. Bromide plays no role in the pathogenesis of acute intoxication. Carbromal and its organic metabolites are eliminated through a large surface dialyzer almost as effectively as with charcoal hemoperfusion. The effectivity of detoxication is enhanced by the combination of both procedures. Free bromide is not adsorbed at charcoal but is readily dialyzable. Values of carbromal, calculated out of bromide levels, do not correspond to directly measured blood levels. Treatment of carbromal intoxication with combined hemoperfusion-hemodialysis should be performed early in all severe, risky or otherwise complicated cases until the patients awakens.

[Disorder of porphyrin metabolism in thallium intoxication (author's transl)]. / Störung des Porphyrinstoffwechsels bei der Thalliumvergiftung.

A 19-year old male ingested in suicidal attempt 750 mg of thallium. He developed the characteristic symptoms of thallium intoxication. During the acute phase the urinary excretion of porphyrins and porphyrin precursors was largely increased. The percentage distribution of the individual metabolites of heme synthesis revealed a preponderance of kopro- and uroporphyrin. This constellation (kopro- greater than uro- greater than tricarboxylic porphyrin) differs appreciably from that one in lead intoxication. The observation of increased urinary excretion of porphyrins and their precursors in a possibly particular spectrum in thallium intoxication is of special interest for differential-diagnostic reasoning. In each case of a toxic disorder of porphyrin metabolism thallium intoxication ought to be considered a possible cause.

[Haemodialysis of acute renal poisoning (author's transl)]. / Hämodialyse einer akuten Nitritvergiftung

A 16-year-old laboratory technician ingested 30 g of sodium nitrite (NaNO2) in a suicidal attempt. Within a short time severe cyanosis and distressing dyspnoea developed. The conservative therapeutic approach with redox substances showed little success. However, haemodialysis resulted in rapid improvement of all signs. After three hours of dialysis the patient was symptom-free and could be discharged after two days without damage due to the intoxication. Additional experimental investigations showed NaNO2 to be easily dialysable. There is, however, no binding to active charcoal.