Saturation Mutagenesis of Human Interleukin-3 (∗) Olins, Peter O.; Bauer, S. Christopher; Braford-Goldberg, Sarah ...
Journal of biological chemistry/The Journal of biological chemistry,
10/1995, Letnik:
270, Številka:
40
Journal Article
Recenzirano
Odprti dostop
A deletion variant of human interleukin-3, hIL-315-125, was produced in the periplasmic space of Escherichia coli and had full activity in an AML193.1.3 cell proliferation assay. Libraries of random ...single-amino acid substitutions were constructed at each of 105 positions in the gene for hIL-315-125. Approximately eight single-site substitutions at each position were produced in osmotic shock fractions and screened for activity. 15 mutants were found with bioactivity of 5-26-fold greater than that of native hIL-3. The majority of amino acids in hIL-315-125 could be substituted without substantial loss of activity. Substitution of residues predicted to be in the hydrophobic core of the protein often resulted in reduced activity and/or low accumulation levels. Only five residues predicted to be on the surface of the protein were intolerant of substitution and hence are candidates for sites of interaction with the receptor. We therefore propose that the majority of residues in hIL-3 serve a structural role and permit the display of a few key residues in the correct configuration for recognition by the receptor.
Abstract Background Immediate reconstruction of perineal defects secondary to abdominoperineal resection (APR) or pelvic exenteration with pedicled flaps decreases post-operative wound complications ...when compared with direct closure in high-risk patients. While prior authors have been proponents of abdominal-based flaps, here we evaluate the role for thigh-based flaps founded on acceptable outcomes and low morbidity. Study Design Consecutive patients referred to a single surgeon between January 2012 and August 2015 who underwent perineal reconstruction with a pedicled gracilis flap were identified. Patients were evaluated for routine pre-operative variables and outcome data analyzed, including time to healing and abdominal and perineal complications. Results Forty patients were included in the study, with a mean follow-up period of 2 years. There was no 30-day mortality and 37 patients (92.5%) were alive at the last follow-up. Five patients (12.5%) experienced donor-site complications while 16 patients (40%) had recipient-site complications, including hematoma, seroma, or dehiscence. Minor complications were seen in 10 (25%) patients while 7 (17.5%) patients had major complications. Obesity (OR 7.5, p=0.01), and active smoking status (OR 9.3, p=0.01) were significantly associated with minor complications; while a history of neo-adjuvant chemoradiation (OR 21.4, p=0.04) was a significant risk factor for any complication. Conclusion The overall complication rate with this technique is comparable to the more commonly used VRAM flap but the potential for, and severity of, donor site complications is reduced with this technique. As such, gracilis flaps may be considered an acceptable alternative to abdominal flaps for selected perineal wounds.
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