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Biomedical subjects

S H Liew

Publications and source records attributed to S H Liew.

At least 19 recordsLinked to original sources
PubMed2005

Long-term results of primary syndactyly correction by the trilobed flap technique.

This paper describes the long term results of a surgical technique used for correction of syndactyly. This technique has been practised by the senior author since 1987 and was published in 1990. The technique involves the use of a dorsal trilobed flap for the reconstruction of the commissure and zig-zag incisions for the fingers. This technique does not require the use of skin grafts. This technique has been used in 62 webs in 44 patients. In this total group, there were 30 patients of primary hand syndactyly with 40 webs. Seventeen patients of primary syndactyly with 25 webs were followed up. The follow-up of these patients ranged from 2 years to 12 years. The long term results reveal a simple, effective technique which does not require the use of skin grafts, and is associated with good functional and far superior cosmetic results.

Child↗
PubMed2004

Microcystic adnexal carcinoma of the eyebrow.

PURPOSE: To describe a case of the largest reported microcystic adnexal carcinoma of the eyebrow in an 89-year-old woman and to review the literature regarding the periorbital occurrence of this tumor. METHODS: Case report and literature review. RESULTS: This case was treated with primary excision and radiotherapy, with no clinical signs of recurrence in the past 6 months. CONCLUSIONS: Microcystic adnexal carcinoma is a rare tumor; however, because of its aggressive local infiltration, ophthalmologists should consider this diagnosis and complete surgical excision. Long-term data are needed to establish outcomes from the different treatment options.

Aged↗
PubMed2002

Prophylactic treatment of deep dermal burn scar to prevent hypertrophic scarring using the pulsed dye laser: a preliminary study.

The pulsed dye laser, by selectively targeting blood vessels, has been used to treat established hypertrophic scars with good effect. This prospective clinical study aims to assess the feasibility of treating deep dermal burn wounds prophylactically before the formation of hypertrophic scars. Patients with burn wounds that took longer than 2 weeks to heal were primarily recruited. Each patient's burn area was divided into a treated area and a negative control. The area was laser treated with the pulsed dye laser (Chromos 585; SLS, Wales) twice at 6 weekly intervals. The appearance of the wound at both sites was inspected visually and scored at 6 weeks, and at 3, 6, and 9 months. Five patients with six burn sites (forearm, arm, and back) were treated. Treated areas achieved better scarring at 6 weeks ( = 0.04, paired -test) and at 3 months ( = 0.003, paired -test). The difference, however, became insignificant at 6 and 9 months. No notable side effects were seen in all patients. Prophylactic treatment of burn wounds with the pulsed dye laser is effective in hastening the resolution of scarring. In the authors' opinion, this treatment may revolutionize the traditional method of hypertrophic burn scar prevention, and should be considered early, especially for patients who are prone to hypertrophic scarring, and in areas where hypertrophic scarring are common.

Adult↗
PubMed2001

The use of ADCON-T/N after repair of zone II flexor tendons.

This double-blinded randomised clinical trial investigated whether application of ADCON-T/N to zone II tendon repairs improved their outcome. Fifty-nine patients were randomised into control or ADCON-T/N treated groups and all followed an early mobilisation regime following tendon repair. Tendon rupture rates were comparable between the control and ADCON-T/N treated patients. At six months follow-up, the ADCON-T/N treated group had better proximal interphalangeal motion.

Adult↗
PubMed1999

Hair removal using the ruby laser: clinical efficacy in Fitzpatrick skin types I-V and histological changes in epidermal melanocytes.

The ruby laser is effective in removing unwanted body hair. The occurrence of cutaneous side-effects such as blistering, hypopigmentation and hyperpigmentation, however, remains problematic. These side-effects are more commonly seen in patients with dark coloured skin, which partly explains the relative scarcity of information on the efficacy of ruby laser hair removal in such patients. The mechanisms of the occurrence of these side-effects are also not known. It was the aim of this study to evaluate the efficacy of ruby laser-assisted hair removal in patients with Fitzpatrick skin type V in a retrospective clinical study and to evaluate the mechanism of post-treatment pigmentary change in a prospective clinical study. The percentage reduction in hair density in patients with skin type V was assessed after a variable period following treatment with the Chromos 694 Depilation Ruby Laser, and was compared with the results of those with skin types I-IV. To study the pigmentary change and melanocyte numbers after laser irradiation, ex-vivo scalp skin and serial patient biopsies were taken and stained with S-100, dopa oxidase and Masson-Fontana methods. Laser treatment reduced melanocyte numbers as measured by DOPA stain but not by S100. Laser treatment resulted in the clearance of pigment from the epidermis on histology. Ruby laser was shown to be effective in removing unwanted hair from patients with dark coloured skin, but with a higher incidence of cutaneous side-effects. The occurrence of hypopigmentation after laser irradiation was thought to be due to the suppression of melanogenesis in the epidermis rather than to destruction of the melanocytes.

Analysis of Variance↗
PubMed1999

Unwanted body hair and its removal: a review.

Despite widespread demand for efficient, reliable methods of eliminating unwanted hair from the face and body, available options were limited until the recent development of laser-assisted hair removal systems. This is a review of the various types of hair removal methods available today with an emphasis on laser-assisted hair removal.

Hair Removal↗
PubMed1999

Ruby laser-assisted hair removal reduces the coarseness of regrowing hairs: fallacy or fact?

There have been anecdotal reports that hairs that regrow after ruby laser-assisted hair removal are finer in appearance. If true, this phenomenon adds to the improved aesthetic effect of laser treatment of unwanted hair. It is the aim of this study to determine whether this phenomenon indeed occurs, and if so, assess its permanence and its mode of action. In this prospective clinical study, 71 patients with 94 treatment sites were treated with the Chromos 694 Depilation Ruby Laser. Hair diameter was measured pre-treatment, and at 3 and 7 months post-treatment. In addition, ex vivo scalp skin was used to assess if the ruby laser selectively damaged coarser hairs. Laser-treated and matched untreated skin samples were histologically assessed and the diameters of hair shafts (normal or obviously damaged) were measured. Results of this study were analysed using Kruskal-Wallis one-way analysis. There was no statistically significant difference between the hair diameter of non-lasered specimens and the hair diameter of the normal hair in lasered specimens. However, a statistically significant difference was seen between the hair diameter of non-lasered specimens and diameters of damaged hair in lasered specimens (P < 0.05). There was a statistically significant difference (P < 0.05) between pre-treatment and 3 month hair diameters, but no statistically significant difference was found between pre-treatment and 7 month hair diameters. In conclusion, ruby laser-assisted hair removal results in a temporary reduction in hair diameter of regrowing hair. This is not due to the selective targeting of larger hair follicles.

Adolescent↗
PubMed1999

The removal of unwanted hair using a ruby laser.

A ruby laser has been developed to remove unwanted hair. Melanin within the hair is used as a natural chromophore. It is postulated that photothermal damage destroys the hair itself and also key cells surrounding the hair follicle to prevent regrowth. A prospective study of laser depilation in 116 patients or 175 sites was performed over a period of 18 months. All the patients had tried other methods of hair removal and found them to be unsatisfactory. Hair counts (follicles/cm2) were used to judge the outcome. The mean follow-up time was 23.25 weeks (range 12-76 weeks). After a mean number of treatments of 1.92 (range 1-20) there was a 56.4% reduction in hair density. Comparing pre- and post-treatment hair density, there was a highly significant reduction (paired t-test: P < 0.00001). Laser removal of hair is now a realistic treatment option.

Adolescent↗
PubMed1999

Ruby laser-assisted hair removal: an ultrastructural evaluation of cutaneous damage.

Ruby laser-assisted hair removal is thought to act via selective photothermolysis of melanin in the hair follicles. Although initial clinical trials of permanent hair removal using ruby lasers are promising, the exact mechanisms of hair destruction and the potential damage to other structures of skin are not known. The aim of this study was to evaluate the cutaneous ultrastructural changes following ruby laser hair removal. Nineteen healthy Caucasian patients with dark (brown/black) hair were treated with the ruby laser and biopsies taken after 0, 2, 3, 5, 7, 14 and 21 days. Specimens were examined by light and electron microscopy. Laser-treated specimens showed widespread coagulation and charring of subcutaneous hair shafts. These obviously damaged follicles were randomly dispersed amongst intact follicles within the same treatment sites. Microscopic changes were also seen in the basal epidermis where melanin was concentrated, irrespective of any obvious macroscopic damage. A low level of inflammatory response seen up to 2 weeks after treatment always followed laser treatment. Suprabasal epidermal necrosis was only seen in patients with blister formation after treatment. Ruby laser irradiation results in selective damage to the hair follicles, with microscopic changes to the basal epidermis. The damage is probably compounded by the inflammatory response to the damaged hair. The normal appearance and distribution of collagen in the dermal layer supported the clinical evidence that laser-assisted hair removal, if performed correctly, does not lead to scar formation.

Biopsy↗
PubMed1999

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.

Hair Follicle↗
PubMed1999

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.

Hair↗
PubMed1999

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.

Cell Division↗
PubMed1999

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 patient's 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.

Adolescent↗
PubMed1997

Splenic conservation in the management of large splenic cysts: case report and literature review.

The majority of splenic cysts occur as a result of parasitic infection, most commonly in countries where hydatid disease is endemic. In the Western world however, their occurrence is extremely rare and aetiology less clear. Approximately 800 cases of non-parasitic splenic cysts have been reported in the world literature to date. Their presentation ranges from that of an incidental finding on abdominal examination to catastrophic intraperitoneal haemorrhage. The methods of treatment of splenic cysts are protean with no universally accepted policy. We report a case of a massive splenic cyst in an adolescent female treated by partial splenectomy. We also present a review of the pertinent literature on this subject paying special attention to the role of conservative surgery with preservation of normal splenic tissue.

Adolescent↗
PubMed1992

Retro-pharyngeal liposarcoma.

We present a case of extensive recurrence of a retro-pharyngeal liposarcoma following surgical removal 18 years previously. The surgery and pathology are discussed, and management strategies of head and neck liposarcomas are reviewed.

Aged↗