Does surface anodisation of titanium implants change osseointegration and make their extraction from bone any easier?

Objectives: Titanium implants have a tendency for high bone-implant bonding, and, in comparison to stainless steel implants are more difficult to remove. The current study was carried out to evaluate, i) the release strength of three selected anodized titanium surfaces with increased nanohardness and low roughness, and ii) bone-implant bonding in vivo. These modified surfaces were intended to give improved anchorage while facilitating easier removal of temporary implants. Material and methods: The new surfaces were referenced to a stainless steel implant and a standard titanium implant surface (TiMAX™). In a sheep limb model, healing period was 3 months. Bone-implant bonding was evaluated either biomechanically or histologically. Results: The new surface anodized screws demonstrated similar or slightly higher bone-implantcontact (BIC) and torque release forces than the titanium reference. The BIC of the stainless steel implants was significant lower than two of the anodized surfaces (p=0.04), but differences between stainless steel and all titanium implants in torque release forces were not significant (p=0.06). Conclusion: The new anodized titanium surfaces showed good bone-implant bonding despite a smooth surface and increased nanohardness. However, they failed to facilitate implant removal at 3 months.

Die Bestimmung von Rhenium und Osmium in Eisenmeteoriten durch Neutronenaktivierung

Die Spurenelemente Rhenium und Osmium wurden in 10 Eisenmeteoriten durch Neutronenaktivierung bestimmt. Die Verteilung beider Elemente erwies sich als weitgehend homogen in den einzelnen Meteoriten. — Während die Osmium-Konzentrationen 1-3 ppm betrugen, lagen die Gehalte des natürlichen β-Strahlers Rhenium nur in der Größenordnung von 0,2 ppm. Eine Abweichung dieser Werte um ca. 2 Zehnerpotenzen wurde beim Meteoriten Sichote-Alin festgestellt. Die durchschnittliche Häufigkeit der Elemente Re und Os in Eisenmeteoriten ergab sich für Rhenium zu 0,071 pro 106 Fe-Atome und für Osmium zu 0,64 pro 106 Fe-Atome.

Induction chemotherapy with capecitabine and oxaliplatin followed by chemoradiotherapy before total mesorectal excision in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiation in patients with locally advanced rectal cancer has no impact on overall survival (OS) and distant recurrences. The aim of the study was to evaluate local downstaging, toxicity and long-term outcome in patients with locally advanced rectal cancer after induction therapy with capecitabine and oxaliplatin (CAPEOX) followed by radiotherapy concomitant with capecitabine [chemoradiotherapy (CRT)] before total mesorectal excision (TME).

PATIENTS AND METHODS

Patients with T4 tumors, all T3N+ tumors or T3 tumors involving or with a distance ≤1 mm to the mesorectal fascia were included. Patients were planned for two cycles of CAPEOX followed by radiotherapy concomitant with capecitabine. TME was carried out 6 weeks after the completion of CRT.

RESULTS

Of 84 consecutively admitted patients starting induction CAPEOX, 77 patients underwent surgery. R0 resection was seen in 94% and T downstaging in 69%. In the intention-to-treat group, pathological complete response was seen in 23%. Five-year disease-free survival (DFS) and OS were 63% [95% confidence interval (CI), 52.2% to 73.7%] and 67% (95% CI, 56.1% to 77.3%), respectively. Grade 3/4 toxicity was seen in 18%, and four deaths occurred within 2 months of therapy.

CONCLUSION

Induction chemotherapy before CRT and surgery showed a high local control rate and promising long-term outcome as OS and DFS.

Adsorption of polycyclic aromatic hydrocarbons (PAHs) by soil particles: influence on biodegradability and biotoxicity

Polycyclic aromatic hydrocarbon (PAH) biodegradation was investigated in contaminated soils from two different industrial sites under simulated land treatment conditions. Soil samples from a former impregnation plant (soil A) showed high degradation rates of PAHs by the autochthonous microorganisms, whereas PAHs in material of a closed-down coking plant (soil B) were not degraded even after inoculation with bacteria known to effectively degrade PAHs. As rapid PAH biodegradation in soil B was observed after PAHs were extracted and restored into the extracted soil material, the kind of PAH binding in soil B appears to completely prevent biodegradation. Sorption of PAHs onto extracted material of soil B follows a two-phase process (fast and slow); the latter is discussed in terms of migration of PAHs into soil organic matter, representing less accessible sites within the soil matrix. Such sorbed PAHs are suggested to be non-bioavailable and thus non-biodegradable. By eluting soil B with water, no biotoxicity, assayed as inhibition of bioluminescence, was detected in the aqueous phase. When treating soil A analogously, a distinct toxicity was observed, which was reduced relative to the amount of activated carbon added to the soil material. The data suggest that sorption of organic pollutants onto soil organic matter significantly affects biodegradability as well as biotoxicity.