Vascular endothelial growth factor is more important than basic fibroblastic growth factor during ischemic wound healing

OBJECTIVES

To test the influence of vascular endothelial growth factor (VEGF) on normal and ischemic wounds in a noncontractive dermal ulcer standardized model in the rabbit ear and to assay the levels of both VEGF and basic fibroblastic growth factor messenger RNA levels in normal and ischemic wounds at different intervals during the healing process.

DESIGN AND INTERVENTIONS

Dermal ulcers were created in the normal and ischemic ears of 20 anesthetized young female New Zealand white rabbits. Either VEGF 121, VEGF 165 (30 microg per wound), or buffered saline solution alone was applied to each wound and covered. Wounds were harvested at day 7 or 10 and evaluated histologically. Twenty-four similar rabbits were wounded in the same manner and their untreated wounds were harvested at 1, 3, 7, and 10 days after wounding. The wounds were analyzed with reverse transcriptase polymerase chain reaction.

MAIN OUTCOME MEASURES

Histologic specimens were measured for amount of new epithelium and granulation tissue. Reverse transcriptase polymerase chain reaction was used to determine basic fibroblastic growth factor and VEGF messenger RNA expression.

RESULTS

Both isoforms of VEGF improved granulation tissue formation in both normal and ischemic wounds with a magnitude similar to other vulnerary agents tested in the past. Vascular endothelial growth factor application had no effect on new epithelium formation. In contrast to basic fibroblastic growth factor, VEGF messenger RNA levels were induced 4 fold by ischemia alone and 6 fold by wounding in both ischemic and normal wounds.

CONCLUSION

Vascular endothelial growth factor seems to be more important than basic fibroblastic growth factor during ischemic wound healing. Treatment of ischemic wounds with VEGF improves the deficit in wound healing produced by ischemia.

Augmented inflammatory responses and altered wound healing in cathepsin G-deficient mice

BACKGROUND

Cathepsin G is a neutral serine proteinase that exists primarily in azurophilic granules of neutrophils, but also as a proteolytically active membrane-bound form. While the specificity and many in vitro biological activities have been described for cathepsin G, little is known about the role of this enzyme in neutrophil function in vivo, particularly as it applies to the wound-healing process.

OBJECTIVE

To determine the role of cathepsin G in cutaneous tissue repair by examination of full-thickness incisional wound healing in mice with a null mutation for cathepsin G.

METHODS

Paired, full-thickness linear incisions were made on the backs of cathepsin G +/+ and cathepsin G -/- mice, and wound tissue was harvested at days 1, 2, 3, 5, 7, 10, and 14 after wounding. Neutrophil influx, myeloperoxidase activity, and migration were examined using light microscopy, the myeloperoxidase assay, and modified Boyden chamber technique, respectively. Wound-breaking strength was measured using tensiometry.

RESULTS

The absence of cathepsin G led to a 42% decrease in wound-breaking strength at day 7 after wounding (n=28; P<.002), which returned to the level of control mice by day 10 after wounding. Wound tissue sections in mice lacking cathepsin G also showed a 26% increase in neutrophil myeloperoxidase activity (n=12; P=.001) and an 18% increase in neutrophil influx (n=14; P=.002) at day 3 after wounding. Wound fluid collected on day 5 after wounding from cathepsin G-deficient mice attracted 58% more neutrophils than wound fluid collected from control mice (n=4; P<.05).

CONCLUSIONS

Neutrophil cathepsin G is important during the early inflammatory stage of wound healing. Cathepsin G may be involved in processing 1 (or more) soluble mediator(s) in the wound milieu that is responsible for neutrophil chemotaxis. Our findings suggest that tight regulation of inflammation is necessary to prevent impaired healing during early tissue repair.

Controversy in breast reconstruction

We have discussed the major controversies in the reconstruction of the breast. As trends in cancer ablative surgery have shifted toward breast conservation techniques, the reconstructive choices available to the plastic surgeon have evolved. Advances in oncology, adjuvant therapy, and surgical techniques have changed the defects left following ablative surgery. Patient preferences have also changed, with a greater number of patients presenting to the reconstructive surgeon having already decided the timing and type of reconstruction they prefer. We must continually remind ourselves that the best and least controversial option is the one reached through appropriate consultation among patient, oncologist, and surgeons.

Soft tissue reconstructive choices for craniofacial reconstruction

The extensive blood supply to the scalp enables the use of local flaps based mainly on the superficial temporal artery: these include skin, temporoparietal fascia, subgaleal fascia, and temporal fascia. Also, the temporalis muscle provides flaps based upon the temporal branches of the internal maxillary artery. On top of the skull, scalp flaps, galeal flaps, and pericranial flaps can be used as random flaps or as axial flaps based on the problems or anatomic reasons that would preclude microvascular reconstruction. The pectoralis, latissimus, splenius capitis, and trapezius muscle flaps can dependably reach the base of the skull. The increasing reliability and versatility of microvascular reconstruction render their use standard for craniofacial reconstruction.