[Effects of clinical application of free anterolateral thigh perforator lobulated flap in repair of electrical burn wounds on head based on the concept of donor site protection].

Objective: To explore the effects of clinical application of free anterolateral thigh perforator lobulated flap in repair of electrical burn wounds on head based on the concept of donor site protection. Methods: A retrospective observational study was conducted. Eight patients with electrical burns with huge scalp defects and exposed skulls were admitted to the First Affiliated Hospital of Zhengzhou University, from May 2017 to December 2019, who were all males, aged 21-57 (39±13) years, sustaining multiple deep partial thickness to full-thickness electrical burns to 5%-14% total body surface area. Among the scalp burn sites of the patients, 1 case was posterior occipital, 2 cases were parietal occipital, 4 cases were parietal temporal, and 1 case was frontotemporal. After debridement, the defect area was 10 cm×9 cm-16 cm×14 cm. The incision area of the free anterolateral thigh perforator lobulated flap was 22 cm×6 cm-30 cm×9 cm. The artery and vein of flap were anastomosed with superficial temporal artery and vein or facial artery and vein, and the other vein of skin flap was anastomosed with superficial vein of recipient area. The donor site of skin flap was closed by layer interrupted tension-reducing suture. After the operation, the survival of flop, donor site wound healing and complications were observed. The flap appearance, wound healing of donor sites, long-term complications and functional recovery of donor sites were observed on follow-up. Results: After the operation, the flaps of 8 patients survived completely without vascular crisis. The donor sites of flaps in all the patients healed well with no osteofascial compartment syndrome. Seven patients were followed up for 3 to 12 months, and 1 case was lost to follow up. During follow-up, the flaps of the patients' heads were in good appearance but with alopecia. The donor sites showed linear scars, which were well hidden. There were no significant differences in sensory and motor functions between the two sides, and no complications were found such as muscle hernia. Conclusions: Free anterolateral thigh perforator lobulated flap has a good clinical effect in the early repair of electrical burn wounds with huge scalp defect and skull exposure on head, and the donor wounds can be directly closed and sutured, greatly reducing the damage to the donor area.

[Meta-analysis of the effects of triamcinolone acetonide alone and in combination with 5-fluorouracil for treating keloids].

Objective: To compare the efficacy and safety of triamcinolone acetonide (TA) alone and in combination with 5-fluorouracil (5-FU) for treating keloids using meta-analysis. Methods: Databases including PubMed, Embase, and Cochrane Library were retrieved with the search terms of " triamcinolone acetonide, 5-fluorouracil, glucocorticoid, fluorouracil, keloid, scar, TAC, 5-FU, hypertrophic scar " and databases including Chinese Journal Full-Text Database, Chinese Biomedical Database, and Wanfang Data were retrieved with the search terms of ",, 5-,," in Chinese to obtain the publicly published randomized controlled trials about the effects of TA alone and in combination with 5-fluorouracil for treating keloids from the establishment of each database to august 2019. The outcome indexes included effective proportion of treatment, incidence proportion of adverse reactions, and recurrence proportion of keloids. RevMan 5.3 and Stata 14.0 statistical software were used to conduct a meta-analysis of eligible studies. Results: A total of 1 326 patients with keloids were included in 14 studies, including 668 patients in TA+ 5-fluorouracil group whose keloids were injected with TA and 5-fluorouracil and 658 patients in TA alone group whose keloids were injected with TA alone. A total of 7 articles achieved 1 to 3 points in modified Jadad score, while 7 articles achieved 4 to 7 points in modified Jadad score. Patients in TA+ 5-fluorouracil group had a higher effective proportion of treatment than that of TA alone group (relative risk=1.28, 95% confidence interval=1.16-1.41, P<0.01). Subgroup analysis showed that the quality of the included literature and ethnic factors might be the source of heterogeneity in effective proportion of treatment. Patients in TA+ 5-fluorouracil group had a lower incidence proportion of adverse reactions than that of TA alone group (relative risk=0.44, 95% confidence interval=0.25-0.75, P<0.01). Patients in TA+ 5-fluorouracil group had a lower recurrence proportion of keloids than that of TA alone group (relative risk=0.25, 95% confidence interval=0.14-0.44, P<0.01). There was no publication bias in incidence proportion of adverse reactions (P>0.05), while the effective proportion of treatment and recurrence proportion of keloids had publication bias (P<0.05). Conclusions: TA combined with 5-fluorouracil is more effective than TA alone for treating keloids, with less incidence of adverse reactions and recurrence.

[Clinical effects of superior gluteal artery perforator " buddy flap" in repairing pressure ulcer in sacrococcygeal region].

Objective: To investigate the clinical effects of superior gluteal artery perforator " buddy flap" in repairing pressure ulcer in sacrococcygeal region. Methods: From January 2017 to December 2018, 13 patients (8 males and 5 females) aged 24-79 years with stage 4 pressure ulcers in sacrococcygeal region were admitted to the First Affiliated Hospital of Zhengzhou University, with wound area from 5 cm×4 cm to 12 cm×10 cm. After thorough debridement and vacuum sealing drainage, the superior gluteal artery perforator " buddy flap" was designed to repair the pressure ulcer in sacrococcygeal region. The pressure ulcer was repaired by the main flap with area from 7.0 cm×5.0 cm to 18.0 cm×12.0 cm; the main flap's donor area was covered by the auxiliary flap with area from 5.0 cm×3.0 cm to 11.0 cm×7.0 cm; the auxiliary flap's donor area was covered by the connecting flap between the main flap and the auxiliary flap. The remaining wound without covering was directly closed by suturing. The postoperative flap survival and complications were observed. The appearance and function of flaps and the recurrence of pressure ulcer were followed up. Results: The flaps of 12 patients survived after operation without complications of infection, fat liquefaction, or poor flap survival. A small area of superficial necrotic skin at the distal end of flap was observed in one case, which was healed after dressing change. All the patients were followed up for 6 months without recurrence of pressure ulcer, and the operation area was naturally full in appearance, which was pressure and wear resistant. Conclusions: Superior gluteal artery perforator " buddy flap" is an effective method for the treatment of pressure ulcer in sacrococcygeal region. The effect of tension-free repair of the pressure ulcer and main flap donor area can be achieved in one operation. The operation is simple, the curative effect is accurate, and it has certain clinical value.

Structure of chymotrypsin-trifluoromethyl ketone inhibitor complexes: comparison of slowly and rapidly equilibrating inhibitors.

The peptidyl trifluoromethyl ketones Ac-Phe-CF3 (1) and Ac-Leu-Phe-CF3 (2) are inhibitors of chymotrypsin. They differ in Ki (20 and 2 microM, respectively) as well as in their kinetics of association with chymotrypsin in that 1 is rapidly equilibrating, with an association rate too fast to be observed by steady-state techniques, while 2 is "slow binding", as defined by Morrison and Walsh [Morrison, J. F., & Walsh, C. T. (1988) Adv. Enzymol. Relat. Areas Mol. Biol. 61, 202], with a second-order association rate constant of 750 M-1 s-1 at pH 7.0 [Imperiali, B., & Abeles, R. (1986) Biochemistry 25, 3760]. The crystallographic structures of the complexes of gamma-chymotrypsin with inhibitors 1 and 2 have been determined in order to establish whether structural or conformational differences can be found which account for different kinetic and thermodynamic properties of the two inhibitors. In both complexes, the active-site Ser 195 hydroxyl forms a covalent hemiketal adduct with the trifluoromethyl ketone moiety of the inhibitor. In both complexes, the trifluoromethyl group is partially immobilized, but differences are observed in the degree of interaction of fluorine atoms with the active-site His 57 imidazole ring, with amide nitrogen NH 193, and with other portions of the inhibitor molecule. The enhanced potency of Ac-Leu-Phe-CF3 relative to Ac-Phe-CF3 is accounted for by van der Waals interactions of the leucine side chain of the inhibitor with His 57 and Ile 99 side chains and by a hydrogen bond of the acetyl terminus with amide NH 216 of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

The refined 2.3 A crystal structure of human leukocyte elastase in a complex with a valine chloromethyl ketone inhibitor.

The stoichiometric complex formed between human leukocyte elastase and a synthetic MeO-Suc-Ala-Ala-Pro-Val chloromethyl ketone inhibitor was co-crystallized and its X-ray structure determined, using Patterson search methods. Its structure has been crystallographically refined to a final R value of 0.145 (8.0 and 2.3 A). The enzyme structure is very similar to that recently observed in a complex formed with the ovomucoid third domain from turkey [(1986) EMBO J. 5,2453-2458]. The rms deviation of all alpha-carbon atoms is 0.32 A. The peptidic inhibitor is bound in a similar overall conformation as the ovomucoid binding segment. Covalent bonds are formed between Val-P1 of the inhibitor and His-57 NE2 and Ser-195 OG of the enzyme. The carbonyl carbon is tetrahedrally deformed to a hemiketal. The valine side chain is arranged in the S1 pocket in the g-conformation.

X-ray crystal structure of the complex of human leukocyte elastase (PMN elastase) and the third domain of the turkey ovomucoid inhibitor.

Orthorhombic crystals diffracting beyond 1.7 A resolution, have been grown from the stoichiometric complex formed between human leukocyte elastase (HLE) and the third domain of turkey ovomucoid inhibitor (OMTKY3). The crystal and molecular structure has been determined with the multiple isomorphous replacement technique. The complex has been modeled using the known structure of OMTKY3 and partial sequence information for HLE, and has been refined. The current crystallographic R-value is 0.21 for reflections from 25 to 1.8 A resolution. HLE shows the characteristic polypeptide fold of trypsin-like serine proteinases and consists of 218 amino acid residues. However, several loop segments, mainly arranged around the substrate binding site, have unique conformations. The largest deviations from the other vertebrate proteinases of known spatial structure are around Cys168. The specificity pocket is constricted by Val190, Val216 and Asp226 to preferentially accommodate medium sized hydrophobic amino acids at P1. Seven residues of the OMTKY3-binding segment are in specific contact with HLE. This interaction and geometry around the reactive site are similar as observed in other complexes. It is the first serine proteinase glycoprotein analysed, having two sugar chains attached to Asn159 and to residue 109.