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Biomedical subjects

K M Chan

Publications and source records attributed to K M Chan.

At least 253 records · Page 14Linked to original sources
PubMed1985

Inaccurate values for direct bilirubin with some commonly used direct bilirubin procedures.

We compared five methods for the determination of total and direct bilirubins in serum samples from normal controls, subjects with Gilbert's syndrome, and serum pools containing about 50 and 150 mg of total bilirubin per liter. The Kodak Ektachem method and a diazotized sulfanilic acid method with 0.15 mmol/L sodium nitrite concentrations are the only methods that gave accurate direct bilirubin values, as judged by liquid-chromatographic results. The aca method that involved p-nitrobenzene diazonium tetrafluoroborate and another diazotized sulfanilic acid method with a higher concentration of sodium nitrite (0.8 mmol/L) yielded falsely high values for direct bilirubin, which could lead to clinical confusion. The more recently introduced diazotized sulfanilic acid method of the aca gave substantially better results than the p-nitrobenzene diazonium tetrafluoroborate method but was still inaccurate. Systematic investigation of these procedures revealed that the overestimation of direct bilirubin by the diazotized sulfanilic acid method was related to the amount of unconjugated bilirubin present and its ability to react as direct bilirubin in the presence of higher concentrations of sodium nitrite. Inherent properties of p-nitrobenzene diazonium tetrafluoroborate appeared to be responsible for inaccuracies in that method, which could not be corrected by varying reagent concentration or the reaction conditions.

Adult↗
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

Closed medullary nailing for fractured shaft of the femur--a comparison between the Küntscher and the AO techniques.

A retrospective review was made of 97 cases of fractured shaft of the femur treated with closed medullary nailing. A comparison was made between the Küntscher and the AO techniques with respect to union of the fracture, rehabilitation, complication and functional results. Patients treated with AO nails enjoyed more rapid recovery: 88 per cent of the fractures united in 12 weeks, 62 per cent walked with full weight bearing in 8 weeks and 78 per cent returned to work within 6 months. However, the functional results in both groups were comparable. The special technical considerations and complications in each group are discussed.

Adolescent↗
PubMed1984

The Krukenberg procedure: a method of treatment for unilateral anomalies of the upper limb in Chinese children.

Eight Chinese patients with congenital absence of the hand were treated with the Krukenberg procedure to provide a pinching function of the forearm bones. The rehabilitation program was simple and the functional results were satisfactory. We have selected three cases to illustrate the Krukenberg procedure and the indications for this operation, a procedure that is particularly suitable for the Chinese who are culturally adapted to chopstick functions.

Activities of Daily Living↗
PubMed1984

Polydactyly of the thumb: a surgical plan based on ninety-five cases.

Preaxial polydactyly constitutes the most common group of congenital anomalies of the hand among the Chinese population of Hong Kong. Ninety-five cases from the Orthopaedic/Plastic and Reconstructive Surgery Unit, Princess Margaret Hospital, Hong Kong (March 1976 to March 1981), were reviewed. The cases were classified according to Wassel's classification (1969) into seven types. The most common category was type IV followed by types II, V, III, VII, I, and VI. The treatment of each type was analyzed. Bilhaut's procedure was satisfactory for type I, and a modified technique was used for types II and III. A method of shaving the incongruous articular cartilage was used in type IV. Removal of the extra digit and osteotomy of the metacarpal usually were required for type V. The experience with types VI and VII was too limited for assessment. Short-term results (1 to 6 years) have been satisfactory, but follow-up until skeletal maturity to assess the ultimate functional and cosmetic results is necessary.

Adult↗
PubMed1984

Sports injuries survey on university students in Hong Kong.

A sports injuries survey was conducted among 1714 students of the Chinese University of Hong Kong. The common sports involved in injuries were Soccer (26%), Basketball (18%), Cycling (11%), Track and field athletics (11%) and Swimming (10%). The lower limb usually took the brunt of the injuries (67%) followed by the upper limb (28%) and spinal injuries were relatively uncommon (3%). The majority of the injuries were mild to moderate and the commonest ones were abrasion (37%), contusion (21%), cramp (20%), sprains (9%), and strains (7%). Of the injuries 80% recovered in less than 10 days and 50% of them were self-treated. However, a significant group of more severe injuries was recorded: fracture, concussion and heat stroke which demanded special medical attention and longer period for recovery. The pattern of treatment was also unique in that traditional Chinese methods of treatment were sought more frequently than special orthopaedic advice. The preventive aspects of sports injuries was not well recognised with only 40% of the students regularly practising warm-up exercises, 18% stretching exercises and 4% using protective aids. More educational programmes and studies were indicated. The set up of a sports injury clinic is recommended with the utilisation of a sports injury reporting system.

Adolescent↗
PubMed1984

The effect of streptozocin-induced diabetes on the plasma membrane calcium uptake activity of rat liver.

The effect of streptozocin (STZ)-induced diabetes on the plasma membrane calcium uptake of rat liver was investigated. Plasma membrane preparations from diabetic rats showed a 2-3-fold increase in calcium uptake activity over controls 3-4 wk after the initial injections. Such an increase can be either reversed or blocked by treating the diabetic rats with exogenous insulin or administering nicotinamide 15 min before and 3 h after the STZ injection, respectively. The activity of 5'-nucleotidase and the [3H]ouabain binding to the plasma membranes were similar in samples from both the control and diabetic rats. These findings made it unlikely that preferential enrichment of plasma membranes or increased proportion of inside-out vesicles was the cause of the enhanced calcium uptake activity in membranes from diabetic animals. In addition, the effect of diabetes on the calcium uptake activity did not diminish even when the assay was performed in the presence of 2.5 microM ruthenium red, an inhibitor of calcium uptake by mitochondria, or when oxalate was omitted from the assay, suggesting that the effect was specifically on the plasma membrane pump. The enhanced calcium uptake activity was a result of an increase in the Vmax (58.8 versus 113.1 pmol calcium/mg protein/min for control and diabetic rats, respectively). No significant change in Km for calcium was detected.

Adenosine Triphosphate↗
PubMed1984

A 24 year survey of amputees in Hong Kong.

A 24-year retrospective study of amputees was conducted at the Prosthetic and Orthotic Unit of the Kowloon Rehabilitation Centre, the first and largest rehabilitation centre in Hong Kong. A review was made of 1821 patients and a rising trend of amputee population was demonstrated probably related to the population growth. The ratio of lower limb to upper limb amputees was 1.83 to 1. The mean age of the amputees was 39 years. The commonest cause of upper limb amputation was trauma (89%) and of lower limb amputation was infection (35%). Vascular diseases were not as common in Chinese as in Caucasian communities. These patterns of amputee population indicate the demand for prosthetic service and provide guide-lines for future development.

Adolescent↗
PubMed1984

Post-traumatic fat embolism--its clinical and subclinical presentations.

A prospective study of post-traumatic fat embolism among a group of Chinese patients suffering from fractures demonstrated an incidence of 8.75% in fracture patients with overt clinical features and a mortality rate of 2.5%. In a multiple-fracture group the incidence of fat embolism was 35%. The significant findings of 64% of the patients with a low arterial pO2 and 52% with positive cryostat tests for fat globules suggested a high incidence of subclinical presentation. The presence of large vacuoles in the cryostat sections is demonstrated and its significance discussed. The 'iceberg' phenomenon of fat embolism syndrome should be well recognized, particularly in patients with multiple fractures.

Adolescent↗
PubMed1984

Effects of azotemia on results of the boronate-agarose affinity and ion-exchange methods for glycated hemoglobin.

We evaluated the effect of azotemia on results for glycated hemoglobin as measured by a boronate-agarose affinity method and an ion-exchange chromatographic procedure with saline preincubation and found a good correlation. However, values for glycated hemoglobin in samples from nondiabetic patients with various degrees of azotemia were consistently higher with the ion-exchange column procedure (mean, 8.5%) than with the boronate affinity method (mean, 6.2%). The latter method may thus be preferred for monitoring glycated hemoglobin in diabetic patients with impaired renal function.

Boronic Acids↗
PubMed1983

Calcium transport and phosphorylated intermediate of (Ca2+ + Mg2+)-ATPase in plasma membranes of rat liver.

We have identified and characterized calcium transport and the phosphorylated intermediate of the (Ca2+ + Mg2+)-ATPase in plasma membrane vesicles prepared from rat liver. The calcium transport did not absolutely require the presence of oxalate and was completely inhibited by 1 microM of ionophore A23187. Oxalate, which serves as a trapping agent in calcium uptake of skeletal muscle and liver microsomes, was not absolutely required to maintain the net accumulation of calcium. The Vmax and Km for calcium uptake were 35.2 +/- 10.1 pmol of calcium/mg of protein/min, and 17.6 +/- 2.5 nM of free calcium, respectively. Ten mM magnesium was required for the maximal accumulation of calcium. Substitution of 5 and 10 mM ADP, CTP, GTP, and UTP for ATP could not support calcium uptake. The calcium uptake was not affected by 0.5 mM ouabain, 20 mM azide, or 2 micrograms/ml of oligomycin but was inhibited in a dose-dependent fashion by vanadate, with a Ki of approximately 20 microM for vanadate. The substrate affinities and specificities of this calcium-transport activity suggest that it is closely associated with the (Ca2+ + Mg2+)-ATPase reported in the plasma membranes of liver (Lotersztajn, S., Hanoune, J., and Pecker, F. (1981) J. Biol. Chem. 256, 11209-11215). A calcium-stimulated and magnesium-dependent phosphoprotein was also demonstrated in the same membrane vesicles. The free calcium concentration at which its phosphorylation was half-maximal was 15.5 +/- 5.6 nM. Sodium fluoride, ouabain, sodium azide, oligomycin, adriamycin, and N,N'-dicyclohexylcarbodiimide did not affect its formation while vanadate at 100 microM inhibited the calcium-dependent phosphorylation by approximately 60%. The properties of this phosphoprotein suggest that it may be the phosphorylated intermediate of the (Ca2+ + Mg2+)-ATPase in the plasma membranes of rat liver.

Animals↗
PubMed1983

Surgical reconstruction of the upper limb in traumatic tetraplegia. A review of 41 patients.

A review is presented of 41 patients with traumatic tetraplegia on whom reconstructive surgery of the upper limb was carried out. Twelve patients were followed up for more than 10 years after operation and the average period overall was seven and a half years. Tendon transfers were made with the aim of providing extension of the elbow or restoring a useful grasp or a combination of both. The assessment was carried out on four main aspects: the function of the elbow, the function of the hand, the ability to carry out the activities of daily living and the effect of the surgical reconstruction on the personal and social achievement of the patient.

Accidents, Traffic↗
PubMed1983

Triphalangeal thumb and five-fingered hand.

A plea is made for greater recognition of the differences between triphalangeal thumb and five-fingered hand. Both conditions can benefit from surgical management but the methods required are entirely different.

Fingers↗
PubMed1983

Interference by hemolysis with various methods for total calcium and its correction by trichloroacetic acid precipitation.

We evaluated the influence of hemolysis on total serum calcium as determined with the Du Pont aca, SMA 12/60, Ektachem 400, Corning 940 EGTA titrator, and the Beckman Astra 8, comparing results with those obtained by atomic absorption spectroscopy. We find that hemoglobin does not influence calcium measurements with the SMA 12/60, Ektachem 400, or Beckman Astra 8. The presence of hemoglobin exceeding 2 to 3 g/L caused falsely high results with the aca and falsely low results with the Corning 940 titrator. Similar interferences may be observed with other titrating or colorimetric procedures that involve direct reaction of the sample with o-cresolphthalein complexone or calcein. Upon removal of the hemoglobin by precipitation with trichloroacetic acid, the values obtained with the aca and the Corning 940 EGTA titrator were similar to those measured by atomic absorption. With nonhemolyzed serum samples the acid treatment had little or no effect on the aca procedure but resulted in a positive bias of approximately 10% with the EGTA procedure. Thus we recommend this trichloroacetic acid procedure for measuring calcium in hemolyzed samples with the aca and, with certain reservations, with the EGTA titrator.

Autoanalysis↗
PubMed1982

Treatment of trochanteric fractures with Ender's nailing in Chinese patients.

A prospective series of 100 Chinese patients with trochanteric fractures treated by Ender's nailing is reported. The average age of the patients was 79 years (range from 57 to 105 years). The follow-up period ranged from 4 to 18 months, with an average of 81/2 months. The mortality rate was 6 per cent. There was no incidence of non-union, delayed union or deep wound infection. Some special procedures in the operative technique to prevent complications are discussed. Weight-bearing walking could be started in the first week after operation in 63 per cent of the patients. The functional result at 6 months was good in 73 per cent. This method of limited operative trauma gave good functional results to patients, limited the blood loss during operation and reduced the operative time. The suitability of the currently available nails to the Chinese patients are discussed.

Aged↗