Eric S. Y. Chan

In vivo trial comparing patients' tolerance of Q‐switched Alexandrite (QS Alex) and Q‐switched Neodymium:Yttrium‐Aluminum‐Garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota

Different types of Q‐switched lasers have been found to be effective in the treatment of nevus of Ota. However, a clinical trial involving in vivo comparison of the use of different laser systems has not been performed. The aim of the present study was to compare the patient tolerance of Q‐switched Alexandrite (QS Alex) and Q‐switched neodymium:yttrium‐aluminum‐garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota.

Late complications of nasal augmentation using silicone implants.

Alloplastic nasal augmentation with silicone elastomer (Silastic) is popular in areas of Asia. Although the silicones are bio-inert, they have been implicated in a number of adverse reactions after implantation. We report our experience of three patients who presented with late complications after nasal augmentation using Silastic implants. The mechanisms of implant failure are proposed. It is advised that this material should only be used on an individual basis in carefully selected cases.

Head and neck cancers associated with Madelung's disease.

AbstractBackground: Madelung’s disease is a rare lipodystrophy that presents with multiple fatty masses in the neck, trunk, and upper extremities. The fatty accumulation is considered a benign disease, but compression of the aerodigestive tract may occur in long-standing disease. Methods: Eight Chinese patients with Madelung’s disease were reviewed. All were male, aged 48 to 67 years, with a history of disease ranging from 4 to 20 years. Two of the eight patients developed aerodigestive symptoms and were subsequently found to have head and neck cancers. These two patients are described. Results: The possible mechanism that may account for an increase in malignant tumors of the airway in this group of patients is the synergistic effect of smoking and alcohol abuse as risk factors for both Madelung’s disease and malignant tumors of the airway. Currently it is recommended that these patients should have their fatty lesions removed surgically. The removal of fat facilitates examination of the neck for signs of cervical lymphadenopathy in malignant disease. Conclusions: Patients with Madelung’s disease should be followed regularly. The development of aerodigestive symptoms should be fully investigated with endoscopy and imaging. The cause of symptoms should not be attributed to fatty compression until a carcinoma of the upper airway has been excluded.

Combination of a new composite biocampatible skin graft on the neodermis of artificial skin in an animal model.

Introduction: There have been very limited and inconsistent attempts at combining the cultured epidermal autograft (CEA) with the neodermis of artificial skin (Integra). The reasons for this remain unknown. The basement membrane proteins of conventional CEA sheets are easily damaged by the dispase treatment during the harvesting of the CEA from the culture flask. The damage of the basement membrane proteins may affect the anchorage of CEA onto the neodermis of Integra. A new Composite Biocompatible Skin Graft (CBSG) was recently developed.

A new system for the cultivation of keratinocytes on acellular human dermis with the use of fibrin glue and 3T3 feeder cells

The growth of human keratinocytes on human acellular dermis in 4 different culture systems was compared. Epidermis was completely separated and removed from dermis after skin samples had been soaked in 0.1% trypsin at 4 degrees C for 1 week. Forty pieces of saline-washed dermis, 1 cm2 each, were randomized into 4 groups: in group A, human keratinocytes that had undergone 2 to 3 cell passages were seeded (30 x 10(4) cell/cm2) onto the dermis and sprayed with a thin layer of fibrin glue and proliferative 3T3 feeder cells that had been growing separately on the culture dish; in group B, the dermis was only sprayed with fibrin glue; in group C, the dermis was treated with 3T3 cells only; and in group D, the dermis was not sprayed with anything. The dermis samples in all groups were raised on a grid to provide an air-liquid culture system. Histology results of the composite grafts at 2 weeks were assessed as having either scanty colonies of keratinocytes (SCK), continuous stratified epithelium (CSE), or no observable keratinocyte growth. Eight out of the ten dermis samples (80%) in group A demonstrated CSE, and 30% of the samples in group B showed SCK. There were 10% SCK and 20% CSE in group C, and in group D, 30% SCK and 10% CSE were found. The good results in group A indicated that the fibrin glue facilitated the seeding efficiency of the keratinocytes on the dermis and that the vital factors released from the 3T3 feeder cells enhanced the growth and differentiation of the keratinocytes. This model provides an optimal system for the cultivation of keratinocytes on acellular dermis.

Burn injuries during paint thinner sniffing

Thinner sniffing is popular among school children in Asian countries because it is readily available at low cost. Besides its toxicity to major organs, thinner inhalation is associated with various burn accidents. Four teenagers were admitted to the Burns Unit of the Prince of Wales Hospital over the period of 1996-1997. They sustained 3-25% TBSA flame burn and two of them had inhalation injuries as a result of the ignition of a cigarette during thinner sniffing. None of them had evidence of thinner intoxication as shown by blood tests. In the management of their acute burn injuries, their hidden social and family problems were explored. With the cooperation of different disciplines, early psychosocial intervention was given and their behavioral and psychological disturbances were successfully managed.

Boiling wax burn in mid-autumn festival in Hong Kong

An unusual cause of burn, contact with boiling wax by children and adolescents during the annual mid-autumn festival in Hong Kong is presented. 57 patients who suffered from hot wax burn over the period 1986-1996 were admitted to the Burns Unit of the Prince of Wales Hospital. This special burn should be preventable by public education.

Pediatric burn patients from Vietnamese camps in Hong Kong from 1989 to 1997

Over the 9 years from 1989 to 1997, many children who suffered from scald burns in the Vietnamese camps in the New Territories of Hong Kong were treated. The profile of these children was examined and analyzed.