Addie Grobbelaar

Differential gene expression in response to transforming growth factor-β1 by fetal and postnatal dermal fibroblasts

The multipotent growth factor transforming growth factor (TGF)‐β1 is consistently linked with fibrosis and scarring. The perfect (scarless) healing of cutaneous wounds in early gestational age fetuses is proposed to be due to this tissues predominance of the TGF‐β3 isoform over the profibrotic TGF‐β1 and 2. Nevertheless, TGF‐β1 is present during wound healing in the early fetus and recently we demonstrated that relevant intracellular signaling pathways are activated (albeit transiently) on TGF‐β1stimulation. This study aimed to determine whether TGF‐β1 has different effects on gene transcription in human fetal (<14 weeks) vs. human postnatal dermal fibroblasts, using real‐time polymerase chain reaction. The regulation pattern of a number of TGF‐β response genes differed dramatically between the two cell sources. The typical autocrine loop of TGF‐β1 autoinduction did not occur in fetal fibroblasts and genes that are normally up‐regulated, connective tissue growth factor and collagen type I were actually down‐regulated. Furthermore, other response genes responded in a delayed fashion (TGF‐β3) compared with that seen in the more developmentally mature postnatal fibroblasts. Finally, genes unaltered by TGF‐β stimulation in postnatal cells, TGF‐β2 and collagen III, were up‐regulated in fetal cells. These developmentally related differences in fibroblast response to TGF‐β1 may influence wound‐healing outcome, i.e., perfect regeneration or fibrosis.

Two‐stage grafting of flexor tendons: results after mobilisation by controlled early active movement

We present the results of two‐stage flexor tendon grafting to the hand followed by early active mobilisation. Twenty‐six digits from 22 patients were assessed over a 10‐year period between 1991 and 2001. Using the LaSalle and Strickland assessment for surgical outcome, we found that 20 digits (77%) achieved excellent or good results. Two ruptured (8%) and one developed adhesions (4%). We think that our results are achieved through meticulous attention to surgical technique with the use of mid‐lateral incisions for surgical access, strong bony fixation of the graft that allows a good interface between tendon and distal phalanx, and a closely supervised early active mobilisation regimen after the repair.

ruby Laser-assisted Hair Removal Success in Relation to Anatomic Factors and Melanin Content of Hair Follicles

Ruby laser-assisted hair removal is thought to work via selective photothermolysis, which relies on light reaching the deeper layers of skin, and the absorption of light by the target chromophore, melanin. It is therefore possible that efficacy of treatment is affected by anatomic factors that determine the amount of light reaching the hair bulbs (i.e., skin color, depth of intracutaneous hair, epidermal thickness and dermal density) and the melanin content of hair. To examine this hypothesis, a prospective study was performed. Forty-eight volunteers were treated with the Chromos 694 Depilation Ruby Laser at a single standard fluence of 11 J/cm2. Treatment efficacy was determined by measuring hair density at 3 and 7 months after treatment. Epidermal depth and dermal density were measured from 2-mm biopsies taken before treatment, and the intracutaneous hair length was determined from plucked hair. Skin color was assessed using a spectrophotometer, and melanin content of dissolved hair was assessed using spectrophotometry. Efficacy of treatment for each patient was compared with the patients age, intracutaneous hair length, epidermal depth, dermal density, skin color, and total melanin content and relative eumelanin content of hair. No correlation was found between the efficacy of treatment and age and the various anatomic factors. Patients with higher eumelanin content in their hair had better long-term results (Spearman rank test, p = 0.00219). The results suggested that the efficacy of treatment did not depend solely on the amount of laser light penetrating the skin but correlated well with the eumelanin content of hair. The clinical implication of this finding is discussed.

The effect of ruby laser light on ex vivo hair follicles: clinical implications.

Several clinical studies on the efficacy of ruby laser-assisted hair removal have reported that regrowth of hair after treatment is common. One of the reasons for the regrowth of hair is the incomplete destruction of germinative hair cells due to the insufficient penetration of the ruby laser in the skin. It was the aim of this study to estimate the extent of damage to the hair follicles after one ruby laser treatment and to determine whether the ruby laser destroyed the bulbs and the bulge regions of hair follicles. The extent of laser damage in hair shafts was determined by serial examination of six specimens of ex vivo scalp skin lasered with the Chromos 694 Depilation Ruby Laser at 14 J per square centimeter and 20 J per square centimeter. Another nine specimens of ex vivo scalp skin were similarly lasered, and monoclonal antibody LP2K was used to identify the bulge regions of the hair follicles using the immunoperoxidase technique. Damage to the bulge region was assessed from consecutive specimens, which were stained with hematoxylin-eosin stain. The mean depth of laser damage sustained by hair follicles was 1.34 mm (14 J per square centimeter) and 1.49 mm (20 J per square centimeter) underneath the skin surface. Most of the laser damage involved the bulge regions but fell short of the hair bulbs. The laser damage did not seem to extend far enough down the hair shafts to result in permanent hair destruction. The clinical implications of this finding are discussed.

Ruby laser-assisted hair removal : A preliminary report of the correlation between efficacy of treatment and melanin content of hair and the growth phases of hair at a specific site

An unpredictable response, even in patients with dark hair, often undermines successful ruby laser hair removal. A prospective clinical study was carried out to evaluate the roles of melanin content and growth phases of hair in treatment efficacy. Thirty-six volunteers with white skin and dark hair were recruited for the study, and were all treated using the Chromos 694 Depilation Ruby Laser. The overall efficacy of treatment was assessed at the end of 3 months. The efficacy of laser treatment is not due solely to the proportion of hair in the growing or static phase of the hair cycle. There is a lack of correlation between the melanin content and the overall efficacy of laser hair removal in those treated once, but patients with darker hair responded better after repeated treatments. The proportion of hair in the growth phase and the melanin content of hair do not contribute solely to the efficacy of ruby laser hair removal.

The temperatures reached and the damage caused to hair follicles by the normal-mode ruby laser when used for depilation.

&NA; Although it is proposed that heat is the cause of follicular damage leading to depilation, this has never been proved. This study aims to determine the mode by which depilation is effected and, if heat is the mechanism, what temperatures are reached within treated follicles and if sufficient damage is produced therein. Two excised specimens of hair‐bearing skin from 5 patients undergoing facelifts were dissected to reveal the hair bulbs/shafts on the deep surface. They were placed on a jig, and one pulse from a normal‐mode ruby laser (NMRL) of 15 J per square centimeter was fired on the epidermal surface. A thermal imaging camera recorded dermal temperature changes on the deep surface in real time. Specimens were then examined histologically for the site and extent of cellular damage by immunohistochemical staining for a protein marker of cell damage (p53). The NMRL targeted hair follicles specifically. The most common follicular temperature increase ranged from 5 to 10°C. In specimens from 1 patient the increase was more than 30°C (p < 0.001). Heat dissipation into interfollicular tissue in all specimens occurred 2 seconds after exposure. Evidence of laser‐induced damage to folliclelining cells was found only in those follicles with damaged hair shafts. The changes were found to a greater depth (to the bulb) and greater extent (beyond the bulge) in those follicles reaching higher temperatures. These findings suggest that the NMRL should produce permanent depilation. The variability between follicles and between patients explains, perhaps, the uneven outcome regarding depilation using the NMRL. Success appears to depend on peak follicular temperatures achieved during laser exposure, which may result from the follicular characteristics of the individual patient. Topping A, Gault D, Grobbelaar A, Green C, Sanders R, Linge C. The temperatures reached and the damage caused to hair follicles by the normal‐mode ruby laser when used for depilation. Ann Plast Surg 2000; 44:581‐590

The effect of ruby laser light on cellular proliferation of epidermal cells.

In ruby laser-assisted hair removal, microscopic damage is often seen in the basal epidermal cells, where melanosomes are concentrated. It is not known whether this treatment leads to cellular hyperproliferation. It was the aim of this study to investigate this. Ten white patients were treated with the Chromos 694-nm Depilation Ruby Laser, and biopsies taken before and after treatments to assess the presence of cell hyperproliferation, which normally accompanies epidermal damage, with immunohistochemical staining of keratin 16 and Ki67. No evidence of cell hyperproliferation was seen in all specimens examined after ruby laser irradiation. The authors conclude that despite the possible microscopic damages seen in the basal epidermis after laser hair removal, there is no evidence of cellular hyperproliferation. This is in contrast to ultraviolet-irradiated cell damage, in which increased basal cell turnover is seen.

A review of the ruby laser with reference to hair depilation

&NA; There is a clinical need in the fields of reconstructive and cosmetic plastic surgery for a safe, simple, and effective method of hair depilation. Depilatory clinics have been established throughout the country, commonly using the ruby laser, to treat a cohort of the population, estimated to be between 6% and 10%, recognized as being hirsute. Clinical trials performed to date have not established a protocol that suits the previously mentioned criteria and have been, usually, small in number and short in follow‐up. With the increased use that this form of laser treatment will inevitably undergo, it is the belief of the authors that the only way of ascertaining whether the treatment is safe, simple, and effective is first to establish how the ruby laser works. This review relates the knowledge that is currently available regarding the function of the ruby laser to a number of the clinical studies that have been undertaken, including three that have used other types of laser. Using this information, future areas in which research is required can be defined, ultimately to improve the clinical efficacy of ruby laser‐assisted hair removal while lessening the current side effects (namely, superficial burning, and hypo‐ and hyperpigmentation). Topping A, Linge C, Gault D, Grobbelaar A, Sanders R. A review of the ruby laser with reference to hair depilation. Ann Plast Surg 2000;44:668‐674

Immunohistochemical endothelial localisation: a novel method of vessel delineation in tendon tissue

The mechanism of tendon healing is still not fully understood. A dual source of nutrition for the tendon is important at times of injury either from synovial-type fluid bathing the tendon or its own blood supply. In addition, neovascularisation occurs at the site of injury from the time of the insult. The aim of this study was to develop a method of precise endothelial localisation in archived paraffin tendon sections, therefore facilitating the study of the healing of tendons within different species. The sections had to retain a high degree of cytoarchitecture and the stain be of enough contrast to allow quantitative assessment of tendon vascularity in different sites and different species. Endothelial staining was produced using an antibody to the endothelial cell surface marker CD-31 (Dako, Cambridge, UK). The signal was intensified using the Catalytic Signal Amplification kit (Dako). It resulted in a dark brown staining of the tendon endothelium, which was in sufficient contrast to allow automated image analysis.