Polyaspartate, a biodegradable chelant that improves the phytoremediation potential of poplar in a highly metal-contaminated agricultural soil.

Phytoremediation is a cost-effective and environment friendly in situ technique for the reclamation of heavy metal-polluted soils. The efficacy of this technique, which relies on tolerant plant species, can be improved by the use of chelating agents. A pot experiment was carried out to evaluate the phytoextraction and phytostabilisation capacities of a white poplar (Populus alba L.) clone named AL35 previously selected for its marked tolerance to copper (Cu) and zinc (Zn). Cuttings were grown on agricultural soil highly contaminated with Cu and Zn, in the presence or not (controls) of a chelant mixture (EDTA/EDDS) known to enhance metal bioavailability and, hence, uptake by plant roots, or the not yet investigated synthetic, highly biodegradable polyaspartic acid (PASP). Both chelant treatments improved the phytostabilisation of Cu and Zn in AL35 plants, whilst the phytoextraction capacity was enhanced only in the case of Cu. Considering that the effectiveness of PASP as phytostabilizer was comparable or better than that of EDTA/EDDS, the low cost of its large-scale chemical synthesis and its biodegradability makes it a good candidate for chelant-enhanced metal phytoextraction from soil while avoiding the toxic side-effects previously described for both EDTA and EDDS.

Computed tomographic colonography in subjects with positive faecal occult blood test refusing optical colonoscopy.

BACKGROUND: Refusal of colonoscopy is a drawback of colorectal cancer screening programmes based on faecal occult blood test. Computed-tomographic-colonography is generally more accepted than colonoscopy. AIM: To compare adherence to computed-tomographic-colonography and second-invitation colonoscopy in subjects with positive faecal test refusing colonoscopy. METHODS: We performed a prospective study in 198 subjects with positive faecal test who refused first referral to colonoscopy in one endoscopy service of the Florence screening programme. Subjects were randomly invited to computed-tomographic-colonography (n = 100) or re-invited to colonoscopy (n = 98). Mail invitation was followed by a questionnaire administered by phone. Computed-tomographic-colonography findings were verified with colonoscopy. RESULTS: 32 subjects could not be reached, 71 (35.9%) had undergone colonoscopy on their own; 4 were excluded for contraindications; 30/48 (62.5%) in the computed-tomographic-colonography arm and 11/43 (25.6%) in the colonoscopy arm accepted the proposed examinations (p < 0.001). Four advanced adenomas and 1 cancer were found in the 28 subjects who ultimately underwent computed-tomographic-colonography and 2 advanced adenomas and 2 cancers in the 9 subjects who ultimately underwent second-invitation colonoscopy. CONCLUSION: Subjects with positive faecal occult blood test refusing colonoscopy show a higher adherence to computed-tomographic-colonography than to second invitation colonoscopy.

Two-step autologous grafting using HYAFF scaffolds in treating difficult diabetic foot ulcers: results of a multicenter, randomized controlled clinical trial with long-term follow-up.

This study evaluated the efficacy and tolerability of an autologous tissue-engineered graft--a 2-step HYAFF autograft--in the treatment of diabetic foot ulcers compared with standard care. In all, 180 patients with dorsal or plantar diabetic foot ulcers (unhealed for ≥1 month) were randomized to receive Hyalograft-3D autograft first and then Laserskin autograft after 2 weeks (n = 90; treatment group) or nonadherent paraffin gauze (n = 90; control group). Efficacy and adverse events were assessed weekly for 12 weeks, at 20 weeks, and at 18 months. The primary efficacy outcome was complete ulcer healing at 12 weeks. Wound debridement, adequate pressure relief, and infection control were provided to both groups. At 12 weeks, complete ulcer healing was similar in both groups (24% of treated vs 21% controls). A 50% reduction in ulcer area was achieved significantly faster in the treatment group (mean 40 vs 50 days; P = .018). Weekly percentage ulcer reduction was consistently higher in the treatment group. At 20 weeks, ulcer healing was achieved in 50% of the treated group as compared with 43% of controls. Dorsal ulcers had a 2.17-fold better chance of wound healing per unit time following autograft treatment (P = .047). In a subgroup with hard-to-heal ulcers, there was a 3.65-fold better chance of wound healing following autograft treatment of dorsal ulcers (P = .035). Adverse events were similar in both groups. The study results demonstrated the potential of this bioengineered substitutes to manage hard-to-heal dorsal foot ulcers.