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Biomedical subjects

M K Li

Publications and source records attributed to M K Li.

7 recordsLinked to original sources
PubMed1992

The dual effect of urinary macromolecules on the crystallization of calcium oxalate endogenous in urine.

The nucleation-promoting and growth-inhibiting activities of urinary macromolecules on the crystallization of calcium oxalate endogenous in urine of stoneformers and normal controls were studied by freezing the ultrafiltrate and retenate fractions of concentrated whole urine (pH 5.3, 1,250 mosmol/kg). Among the normal controls, macromolecules nominally of 10-20 kDa showed nucleation-promoting and growth-inhibiting activities; the 5-10 kDa population was incapable of such effects but did cooperate with molecules greater than 10 kDa in enhancing the effect. In the case of stone-formers, molecules in the nominal ranges of 5-10 kDa and 10-20 kDa when considered separately were not active in the aspects studied but collectively could cooperate to produce pronounced effects. Application of the test to urine ultrafiltrate reconstituted with polyanionic macromolecules recovered from urine indicated that molecules from stoneformers were more powerful than those from normal controls in bringing about promotion of nucleation and inhibition of growth of crystals from urinary calcium oxalate.

Adult↗
PubMed1992

Laparoscopy-guided percutaneous cholecystolithotomy: an evolving technique.

Gall-bladder conservation therapy has been evolving during the past decade. Popular techniques of conservative therapy are extracorporeal shock wave lithotripsy (ESWL) and medical dissolution therapy. The limitations of these procedures have prompted a search for alternative techniques, particularly in relation to percutaneous stone extraction. The cases of four patients with symptomatic gallstones who underwent percutaneous cholecystolithotomy under laparoscopic guidance are reported. The gall-bladder was punctured with a long needle and the tract dilated so that a nephroscope could be introduced. Three cases required stone fragmentation by an ultrasonic lithotripter before removal. Postoperative recovery was uneventful in all cases.

Adult↗
PubMed1992

Tracheal rupture from incorrect positioning of endotracheal tube.

Significant ischaemic tracheal damage from endotracheal intubation is uncommon when the lateral wall pressure exerted by the cuff does not exceed the mean capillary perfusion pressure of the mucosa. This is facilitated by the modern endotracheal tubes with high-volume-low-pressure cuffs. We report a case of tracheal rupture due to an incorrectly positioned softcuffed tube. The need to review tube position radiologically and to make immediate adjustment cannot be overemphasised.

Aged↗
PubMed1992

Preliminary experience in ileal neobladder reconstruction.

In the treatment of transitional cell carcinoma of the bladder, the recent trend is towards radiation or chemotherapy which can be either regional or systemic. There have also been good results with giving Mitomycin or Bacillus Calmette Guerin instillation into the bladder for superficial tumours. There are occasions where patients present with large bulky tumours which cannot be controlled by endoscopic measures, invasion involving multiple sites and carcinoma in-situ which progresses to invasion. In these occasions, we have to resort to surgical clearance of the tumour. If it is possible, all patients would not like to wear a urinary bag for the rest of their lives. A bladder replacement if ever possible is always welcomed because the patient can pass urine from the natural passage. Due to the magnitude of a radical cystectomy and status of the urethra, it is not always technically possible to reconstruct the bladder. With improvement of operative techniques and suture materials, there has been a recent development of a method of bladder reconstruction that uses an ileal pouch. We report our early experience with this operation.

Aged↗
PubMed1990

Demonstration of Lipiodol in paraffin sections using a modified silver impregnation technique.

To demonstrate postangiographic Lipiodol (LIP) in hepatocellular carcinoma (HCC) in paraffin sections, direct impregnation of formalin-fixed tissue blocks with silver nitrate (AgNO3) was followed by routine processing. LIP appeared as black globules in the sinusoids. Ninety-four tissue blocks from 13 postangiographic LIP HCCs and 69 from 8 non-LIP HCCs and 4 fatty livers were studied. Seventy-two of 73 negative controls and all positive blocks as seen on soft tissue radiographs (STRs) were correctly coded (specificity 98.6%, sensitivity 100%). Twenty-six of the 44 LIP-negative areas on STRs from LIP cases contained scanty globules of less than 10 microns in diameter. Fatty change gave no positive readings. Thus, modified AgNO3 impregnation is a simple, accurate means of detecting LIP in high-quality paraffin sections suitable for tumor diagnosis and, if applied to postangiographic LIP, ultrasonographically guided liver biopsy, can verify that a biopsy has reached a suspected tumor focus.

Biopsy↗
PubMed1990

Newcastle bone disease in Hong Kong: a study of aluminum associated osteomalacia.

We measured serum aluminum concentrations in 104 haemodialysis patients from 3 centres in Hong Kong. We found that the 52 patients dialyzed in unit A had much higher mean aluminium levels (100 micrograms/L) than those from the other two units (61 and 39 micrograms/L respectively). In unit A, where water treatment by reverse osmosis had been introduced only recently, 30.8% of patients had fractures/looser zones, 46.2% had rugger-jersey spine and 28.8% had skeletal erosions. When these patients were divided into two groups according to whether their serum aluminium concentration was below or above 100 micrograms/l, the latter patients had significantly lower alkaline phosphatase, serum phosphate, and higher total prescribed dose of aluminium hydroxide. It was concluded that both dialysate aluminium and oral aluminium intake seemed to have contributed to the high incidence of osteomalacic fractures among Unit A patients. In eight of these patients serum aluminium increased by more than 150 micrograms/L after four weeks of receiving 1.5 g desferrioxamine twice weekly. Serial X-rays showed that the mean time after dialysis for the appearance of fractures/Looser zones was 72 months. Three patients developed fractures/Looser zones after successful renal transplantation; and it was postulated that the prompt excretion of aluminium permitted increased osteoclastic activity, resulting in fractures in these patients.

Adult↗