A novel antimicrobial peptide S24 combats serious wound infections caused by Pseudomonas aeruginosa and Acinetobacter baumannii.

OBJECTIVES: Pseudomonas aeruginosa and Acinetobacter baumannii are ranked as top-priority organisms by WHO. Antimicrobial peptides (AMPs) are promising antimicrobial agents that are highly effective against serious bacterial infections. METHODS: In our previous study, a series of α-helical AMPs were screened using a novel multiple-descriptor strategy. The current research suggested that S24 exhibited strong antimicrobial activity against major pathogenic bacteria, and displayed minimal haemolysis, good serum stability and maintained salt resistance. RESULTS: We found that S24 exerted an antimicrobial effect by destroying outer membrane permeability and producing a strong binding effect on bacterial genomic DNA that inhibits genomic DNA migration. Furthermore, S24 exerted a strong ability to promote healing in wound infected by P. aeruginosa, A. baumannii and mixed strains in a mouse model. CONCLUSIONS: Overall, S24 showed good stability under physiological conditions and excellent antimicrobial activity, suggesting it may be a potential candidate for the development of serious bacterial infection treatment.

Hyperbranched polymers with thermoresponsive property highly sensitive to ions.

The salt effects on the water solubility of thermoresponsive hyperbranched polyethylenimine and polyamidoamine possessing large amounts of isobutyramide terminal groups (HPEI-IBAm and HPAMAM-IBAm) were studied systematically. Eight anions with sodium as the counterion and ten cations with chloride as the counterion were used to measure the anion and cation effects on the cloud point temperature (T(cp)) of these dendritic polymers in water. It was found that the T(cp) of these dendritic polymers was much more sensitive to the addition of salts than that of the traditional thermoresponsive linear polymers. At low anion concentration, the electrostatic interaction between anions and the positively charged groups of these polymers was dominant, resulting in the unusual anion effect on the T(cp) of these polymers in water, including (1) T(cp) of these dendritic polymers decreasing nonlinearly with the increase of kosmotropic anion concentration; (2) the chaotropic anions showing abnormal salting-out property at low salt concentration and the stronger chaotropes having much pronounced salting-out ability; (3) anti-Hofmeister ordering at low salt concentration. At moderate to high salt concentration, the specific ranking of these anions in reducing the T(cp) of HPEI-IBAm and HPAMAM-IBAm polymers was PO(4)(3-) > CO(3)(2-) > SO(4)(2-) > S(2)O(3)(2-) > F(-) > Cl(-) > Br(-) > I(-), in accordance with the well-known Hofmeister series. At moderate to high salt concentration, the specific ranking order of inorganic cations in reducing the T(cp) of HPEI-IBAm polymer was Sr(2+) ≈ Ba(2+) > Na(+) ≈ K(+) ≈ Rb(+) > Cs(+) > NH(4)(+) ≈ Ca(2+) > Li(+) ≈ Mg(2+). This sequence was only partially similar to the typical Hofmeister cation series, whereas at low salt concentration the cation effect on T(cp) of the dendritic polymer was insignificant and no obvious specific ranking order could be found.

The [3+2] Annulation of CF3-Ketimines by Re Catalysis: Access to CF3-Containing Amino Heterocycles and Polyamides.

Transition metal catalyzed [3 + 2] annulation of imines with double bonds via directed C-H activation offers a direct access to amino cyclic motifs. However, owing to weak coordination and steric hindrance, trifluoromethylated ketimines have been an unaddressed challenge for TM-catalyzed annulations. Here, a rhenium-catalyzed [3 + 2] annulation of trifluoromethylated ketimines with isocyanates via C(sp2)-H activation has been disclosed. This approach provides an efficient platform for rapid access to a privileged library of CF3-containing iminoisoindolinones and polyamides by utilizing challenging CF3-ketimines as the annulation component. The capability of gram scale synthesis, the post-functionalization of the cyclization adduct, the derivation of complex natural molecules and the facile synthesis of polyamides highlight a diversity of synthetic potential of the current methodology.

[Oil content of Pyracantha seeds and its relations to soil nutrients in northwestern Hunan Province].

Pyracantha seeds were collected from five habitats in the Karst region of northwestern Hunan Province, and the oil content and its components were determined, with their relations to soil nutrients studied. The results showed that soil total P had positive correlation with the linolic acid in P. fortuneana seed oil, while other soil nutrients had no correlations with the fat acids in the oil. The vitamin E in seed oil had significant positive correlations with soil total Ca and total Mg. The P. fortuneana seeds in test region had the maximum oil content of 5.9%, and the average vitamin E content of 9.9 g x kg(-1). The relative contents of linolic acid, oleic acid and palmic acid were 63.7%, 20.8% and 13.2%, respectively.

[Clinical applications of the neurocutaneous axial flap pedicled with perforating vessels].

OBJECTIVE: To report the operative technique and clinical results of the neurocutaneous vascular axial flap with perforating vessels as its pedicle. METHODS: An axial skin flap was designed along the axis of small paraneural vessels that was close to a concomitant cutaneous nerve. The cutaneous perforating branches of major arteries were used as the pedicle, which provided a rotation arc for the flap to cover the defects in the distal site of extremities. 43 neurocutaneous vascular axial flaps were transferred, including 13 sural neurocutaneous axial flaps (30 cm x 12 cm to 16 cm x 8 cm) supplied by perforating branches of the peroneal vessel; 9 saphenous neurocutaneous axial flaps (15 cm x 8 cm to 5 cm x 4 cm) with posterior tibial perforators as the pedicle; 8 posterior antebrachial neurocutaneous axial flaps (16 cm x 6 cm to 10 cm x 4 cm) based on the dorsal branch of the anterior interossea vessel and 13 reversed neurocutaneous axial flaps (6.0 cm x 3.5 cm to 2.5 cm x 1.5 cm) on the dorsal hand pedicled with the perforators at the interdigital web space. RESULTS: 42 flaps survived completely. One flap underwent venous congestion with necrosis on the distal one fourth of the flap. The color and texture of the flaps were good. The appearance and functional results were satisfactory as revealed by follow-up for 6 to 24 months. CONCLUSIONS: The modified operation combines the advantages of both the perforator flap and the neurocutaneous axial flap, enlarges the size of the flap and extends the scope of reconstruction. The flap is characterized with delicate designation, easy dissection and reliable blood supply. It is a good method in repairing the skin defects of the extremities.

Clinical applications of the neurocutaneous axial flap pedicled with perforating vessels / 中华整形外科杂志

<p><b>OBJECTIVE</b>To report the operative technique and clinical results of the neurocutaneous vascular axial flap with perforating vessels as its pedicle.</p><p><b>METHODS</b>An axial skin flap was designed along the axis of small paraneural vessels that was close to a concomitant cutaneous nerve. The cutaneous perforating branches of major arteries were used as the pedicle, which provided a rotation arc for the flap to cover the defects in the distal site of extremities. 43 neurocutaneous vascular axial flaps were transferred, including 13 sural neurocutaneous axial flaps (30 cm x 12 cm to 16 cm x 8 cm) supplied by perforating branches of the peroneal vessel; 9 saphenous neurocutaneous axial flaps (15 cm x 8 cm to 5 cm x 4 cm) with posterior tibial perforators as the pedicle; 8 posterior antebrachial neurocutaneous axial flaps (16 cm x 6 cm to 10 cm x 4 cm) based on the dorsal branch of the anterior interossea vessel and 13 reversed neurocutaneous axial flaps (6.0 cm x 3.5 cm to 2.5 cm x 1.5 cm) on the dorsal hand pedicled with the perforators at the interdigital web space.</p><p><b>RESULTS</b>42 flaps survived completely. One flap underwent venous congestion with necrosis on the distal one fourth of the flap. The color and texture of the flaps were good. The appearance and functional results were satisfactory as revealed by follow-up for 6 to 24 months.</p><p><b>CONCLUSIONS</b>The modified operation combines the advantages of both the perforator flap and the neurocutaneous axial flap, enlarges the size of the flap and extends the scope of reconstruction. The flap is characterized with delicate designation, easy dissection and reliable blood supply. It is a good method in repairing the skin defects of the extremities.</p>