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Biomedical subjects

J C Cheng

Publications and source records attributed to J C Cheng.

At least 127 records · Page 7Linked to original sources
PubMed1990

An analysis of 1704 burn injuries in Hong Kong children.

Over a 12-month period, 1704 children less than 15 years old with burn injuries seen in the accident and emergency departments of seven major regional hospitals in Hong Kong were analysed with respect to their epidemiological data. The age group with the highest risk for injury was 0-4 years (57 per cent) and with a maximum at 1-2 years of age. Boys showed a significantly higher incidence of burns than girls at any age. Ninety-three per cent of the accidents occurred at home and 92 per cent were scalds caused by hot water and other fluids. In the great majority of patients the total body area of burn did not exceed 5 per cent. Younger children had a higher incidence of burns involving the head, face and anterior trunk, 39 per cent of the 0-4 year age group required hospital admission. During the winter months, the children tended to suffer from deeper burns.

Accidents, Home↗
PubMed1990

Frequent inactivation of the retinoblastoma anti-oncogene is restricted to a subset of human tumor cells.

We have used polyclonal anti-synthetic peptide serum to study the role of retinoblastoma gene (RB) inactivation in a variety of human tumor cell lines. Our analysis indicates that inactivation of the RB protein, p105-Rb, is universal in retinoblastoma cells, vindicating the predictions of the Knudson "two-hit" hypothesis. In addition, our analysis has shown that inactivations of the RB gene are nearly as frequent in a more common human tumor, small cell lung carcinoma. One-third of bladder carcinomas surveyed also carry altered or absent p105-Rb. Other human tumors by contrast demonstrate only infrequent inactivation of the RB gene. These results suggest that inactivation of the RB gene is a critical step in the pathogenesis of a subset of human tumors.

Base Sequence↗
PubMed1989

Glutaraldehyde-treated bioprosthetic substitute for rabbit Achilles tendon.

The biomechanical properties and histocompatibility of a glutaraldehyde-treated xenograft were examined after implanting it in 27 rabbits. This xenograft was used as an Achilles tendon substitute placed in vivo for 2 to 48 wk. The specimens were then subjected to mechanical strength testing using a specially constructed tensioning device. The contralateral Achilles tendon was used as the reference baseline. Mechanical testing showed that the strength of the implanted graft increased to 33.5% of the normal side at week 10 and to 79.5% at week 14. The host generated a fibrous cord around the xenograft, linking the two ends of the Achilles tendon. Light and electron microscopic examination showed fibroblastic infiltration of varying magnitude in all specimens but no statistical correlation between degree of infiltration and duration of implantation was found. Also, there was no histological evidence of immunological rejection within the 48 wk of study.

Achilles Tendon↗
PubMed1988

Primary malignant lymphoma of the deep tissues of the hand.

A 39-year-old tailor was seen initially with primary extranodal malignant lymphoma of the deep soft tissues of the right hand. The diagnosis was confirmed by immunocytochemical staining technique on the biopsy material. Review of the literature showed that this is a rare presentation. The prognosis is related to histologic grading. The patient received radiotherapy and the lesion responded rapidly. He was free of the disease 1 year later.

Adult↗
PubMed1987

Mechanical characterisation of human postburn hypertrophic skin during pressure therapy.

Postburn hypertrophic scar commonly occurs among the Chinese resulting from serious burn injuries. A non-invasive method of preventing and controlling such scars is using pressure therapy. Its mechanical properties are used as a quantitative indicator for scar assessment and maturation. The non-linear properties of the skin tissue are characterised in this study by a modulus of elasticity and a percentage extension (strain) at load intensities of 20, 40 and 100 g. The latter is a measure of the scar extensibility while the former the scar stiffness. A correlation is obtained between the clinical scar grading and these mechanical properties. Altogether 300 individual measurements were made on fifteen Chinese patients of ages ranging from 18 to 44 with burn injuries of superficial to whole skin thickness burns which necessitated surgical graft procedures. This in vivo study of the mechanical properties of hypertrophic scar tissue lasted 2 yr.

Adolescent↗
PubMed1987

Classification of 578 cases of congenital upper limb anomalies with the IFSSH system--a 10 years' experience.

There were 578 patients with more than 728 congenital anomalies of the upper limb seen in our center over a 10-year period. All anomalies were classified with the system recommended by the International Federation of Societies for Surgery of the Hand (IFSSH). Our results differ from other reported series with group III duplication anomalies being most common (35.9%) followed by group II (31.3%); group I (12.2%); group VII (9.3%), group VI (6.5%), group V (4.3%), and group IV (0.5%). Variations among different ethnic groups are significant although some apparent differences can also result from different patient referral patterns and method of classification. The classification adopted by the IFSSH was found to be practical in the majority of cases. However, difficulties were encountered in the classification of multiple anomalies; group VII cases and the complex spectrum of atypical cleft hand, brachysyndactyly, and transverse arrests. In addition, many common anomalies had not been included in the classification.

Abnormalities, Multiple↗
PubMed1987

Involvement of renal allograft by Fabry's disease.

A man with Fabry's disease received a renal allograft from a heterozygous sister. Renal allograft dysfunction necessitated an allograft biopsy 5.5 years after transplantation. Extensive accumulation of Fabry's disease deposits in the glomeruli, tubules, blood vessels and interstitium was noted.

Adult↗
PubMed1986

An unusual cause of wrist pain.

A young man with painful swelling over the dorsum of his wrist was found to be caused by an anomalous extensor indicis proprius muscle.

Adult↗
PubMed1986

Use of bioprosthetic tendon in digital pulley reconstruction--an experimental study.

The potential clinical application of Glutaraldehyde treated bioprosthetic material in the hand as implants to substitute for damaged pulley, tendon or ligament has not been fully explored. This study tries to evaluate the efficacy and safety of the proposed bioprosthetic pulley in an experimental model. One of the digital flexor pulleys of the rabbit's foot was excised and replaced by a bioprosthetic pulley using a standardized technique. Autogenous tendon graft was used as the control on the opposite foot. Altogether twenty rabbits (40 feet) were included in the study and they were sacrificed at different time intervals up to one year. The retrievals were analysed for flexor tendon adhesions and rupture of the pulley macroscopically. Histological and Electron Microscopy study of the 'pulley' and 'pulley-bone' junction were also carried out. Results show consistently the progressive creeping substitution of the bioprosthetic material by the rabbit's own tissue without significant inflammatory reactions. Neither adhesions nor breakage of the pulley were detected, the results comparing favourably with the control group using autografts except for the longer time taken for the substitution process.

Animals↗
PubMed1986

Burn contractures of the foot.

Four different types of post-burn contractures of the foot, mild, moderate, severe, and mutilated, are described. The varying degrees of involvement require different methods of treatment, which are described in detail.

Burns↗
PubMed1985

The place of the dynamic compression plate in femoral shaft fractures.

A retrospective study of 32 adult patients with fractures of the femoral shaft treated with the AO dynamic compression plate in one centre was carried out. Pathological fractures, transverse and short oblique fractures in the middle third of the femur were excluded from this study. The average follow-up was 3.5 years. The complications were failure of the implant in 6.3 per cent of cases, loosened screws in 3 per cent, refracture in 3 per cent and non-union in 3 per cent. No instance of deep infection was encountered. The average time taken for union was 5.5 months. The overall objective assessment showed excellent or good results in 90.6 per cent of cases. There is a definite place for the AO dynamic compression plate in well-selected cases of fracture of the femoral shaft, provided that close attention to technical details is observed. Timing of the operation and the postoperative care also affect the results.

Adolescent↗
PubMed1985

Psychosocial adjustment of victims of occupational hand injuries.

A group of hand injury patients was followed up 2-3 years after their injury. Compared to a non-patient control group hand injury patients were more externally oriented, and reported more psychological symptoms. Based on their General Health Questionnaire scores, the patients were divided into a low score and a high score group. High GHQ scores were associated with external locus of control, less social activities, and dissatisfaction with social life. The medical rating of loss of earning capacity was not predictive of overall occupational or psychosocial adjustment. Suggestions are made for future research into determinants of occupational adjustment of these patients.

Accidents, Occupational↗
PubMed1985

8-Substituted guanosine and 2'-deoxyguanosine derivatives as potential inducers of the differentiation of Friend erythroleukemia cells.

A variety of 8-substituted guanosine and 2'-deoxyguanosine derivatives were synthesized and tested as inducers of the differentiation of Friend murine erythroleukemia cells in culture. The most active agents in the guanosine series were 8-substituted-N(CH3)2, -NHCH3, -NH2, -OH, and -SO2CH3, which caused 68, 42, 34, 33, and 30% of erythroleukemia cells to attain benzidine positivity, a functional measure of maturation, at concentrations of 5, 1, 0.4, 5, and 5 mM, respectively. The 8-OH derivative of the 2'-deoxyguanosine series produced comparable activity, causing 62% benzidine-positive cells at a level of 0.2 mM. These findings indicate that 8-substituted analogues of guanosine and 2'-deoxyguanosine have the potential to terminate leukemia cell proliferation through conversion to end-stage differentiated cells.

Animals↗
PubMed1985

Purine and 8-substituted purine arabinofuranosyl and ribofuranosyl nucleoside derivatives as potential inducers of the differentiation of the Friend erythroleukemia.

Several antimetabolites have been demonstrated to have the capacity to initiate differentiation in vitro of a variety of leukemic cell lines. To explore the structural requirements for this activity, a series of purine and 8-substituted purine arabinofuranosyl and ribofuranosyl nucleoside derivatives were synthesized and tested as inducers of the differentiation of Friend murine erythroleukemia cells. 9-(beta-D-Arabinofuranosyl)hypoxanthine and 6-(hydroxyamino)-9-(beta-D-arabinofuranosyl)purine were effective inducers of maturation, producing 82% and 74% benzidine-positive cells, a measure of the number of cells synthesizing hemoglobin. 6-Mercapto-9-(beta-D-ribofuranosyl)purine and 6-(methylmercapto)-9-(beta-D-ribofuranosyl)purine and their corresponding beta-D-arabinofuranosyl derivatives were also effective initiators of maturation, causing approximately 50% of the cell population to assume a differentiated phenotype.

Animals↗
PubMed1984

The management of type III open tibial fractures.

In extensive type III open tibial fractures, limb salvage is considered worthwhile when there is good distal circulation and nerve function. The use of the external fixator has revolutionized the management of skin and soft tissues. However, the subsequent morbidity is still high. A retrospective study of 17 cases is analysed: the amputation rate was 6 per cent, delayed union 60 per cent, infected non-union 30 per cent and mal-union 40 per cent. The final functional result was good in 13 per cent of cases, satisfactory in 30 per cent, fair in 30 per cent and poor in 27 per cent. All patients preferred a functional limb to a prosthesis. The technique of using external fixation and the subsequent management are discussed. To improve the result, we recommend perfect alignment, fixation of the fracture with semi-rigid external fixation and early cancellous bone grafting for comminuted fractures and bone loss. Secondary internal fixation using implants is not advisable. A radical approach is necessary in infected ununited fractures. This includes excision of dead and contaminated tissue and the insertion of gentamicin methyl methacrylate bead implants. Although the complication rate is high and the rehabilitation period is prolonged, the main aims of limb salvage, viz. to retain a functional leg, are largely fulfilled.

Adolescent↗
PubMed1984

Pressure therapy in the treatment of post-burn hypertrophic scar--a critical look into its usefulness and fallacies by pressure monitoring.

Pressure therapy is generally accepted as the best noninvasive means of preventing and controlling hypertrophic scarring after burn injury. Most studies in the past have failed to correlate clinical response with magnitude of the garment-scar interface pressure. This study looked critically at our usual techniques of pressure therapy using pressure 'sensors' manufactured locally and based on electro-pneumatic principles. Many pitfalls, such as large variations of pressure at different geometric sites on the body, elastic deterioration in garments, problems of garment manufacture, and the unfavourable properties of the Lycra garments, were observed. Recommendations on pressure treatment were made based on our experiences, to improve the present technique of pressure therapy. These included the standardization of measurement techniques and garment tailoring, the regular checking of pressure at the garment-scar interface using pressure transducers, the appropriate garment adjustments, a strict regimen for garment wearing, and the intelligent use of pressure-padding and reinforcement. Areas of further research are also discussed.

Burns↗