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Biomedical subjects

K K Fung

Publications and source records attributed to K K Fung.

14 recordsLinked to original sources
PubMed2006

Rapidly progressive necrotising fasciitis following a stonefish sting: a report of two cases.

Two patients developed rapidly progressive necrotising fasciitis after being stung by a stonefish. Both were given a hot-water bath for pain relief. The hot water may have accelerated bacterial growth and the consequent development of necrotising fasciitis. Vibrio vulnificus was cultured from one patient. It is recommended that patients should receive high dose of oral and intravenous antibiotic prophylaxis for vibrio prevention. Antibiotics should be given before or during, not after, a hot-water bath, and the patient's condition should be monitored closely.

Adult↗
PubMed2004

TEM study of the structural dependence of the epitaxial passive oxide films on crystal facets in polyhedral nanoparticles of chromium.

Nanocubes and partially truncated rhombic dodecahedral nanoparticles of Cr have been studied by electron diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. It is found that the nanoparticles of Cr are enclosed by the epitaxial passive oxide films. The oxide films on 100% truncated nanocubes of Cr with only one kind of facets, (100) facets, are face-centered cubic (fcc) structured Cr(2)O(3) with a lattice constant of 0.407nm. There are two kinds of oxide films in partially truncated nanoparticles of Cr with two kinds of crystallographic facets, (100) and (110). The same fcc Cr(2)O(3) is found on the (100) facets while the rhombohedral [Formula: see text] -Cr(2)O(3) is found on the (110) facets. This is similar to the two kinds of oxides, fcc and rhombohedral Fe(2)O(3), which have also been observed in polyhedral nanoparticles of Fe. These passive Cr(2)O(3), found in nanoparticles of Cr which have remained unchanged in water for four years, may have important implications for protective oxide films involving Cr.

Journal Article↗
PubMed2001

The effect of beam tube potential variation on gonad dose to patients during chest radiography investigated using high sensitivity LiF:Mg,Cu,P thermoluminescent dosemeters.

Optimization of X-ray beam tube potential (kVp) in radiological examinations can minimize patient dose. This research aims to investigate the effect of tube potential variation on gonad doses to patients during posteroanterior (PA) chest radiography examinations. This study was carried out using a Toshiba general purpose X-ray unit and a Rando phantom. Dose measuring equipment included an ion chamber system, a dose-area product (DAP) meter and a thermoluminescent dosemeter (TLD) reader system with high sensitivity TLD pellets of LiF:Mg,Cu,P for low level gonad dose measurement. PA chest exposures of the phantom to produce a constant exit dose were made using a standard low tube potential (range 60-100 kVp) non-grid technique and a high tube potential (range 95-150 kVp) grid technique. Entrance surface doses (ESDs) and DAPs were also included in the measurements. Effective doses (EDs) were computed from ESD and DAP measurements using NRPB-SR262 and Xdose software. Results show that with the low tube potential technique both ovary dose and testes dose increase with increasing tube potential; statistically significant correlations of r = 0.994 (p = 0.0006) and r = 0.998 (p = 0.001), respectively, were found. For both organs, doses increase at a rate of approximately 2% per kVp. With the high tube potential technique there is insignificant correlation between gonad doses and tube potential. When comparing patient doses from typical exposures made at 70 kVp (low tube potential non-grid technique) with doses from exposures made at 120 kVp (high tube potential grid technique), the high tube potential technique delivers significantly higher values for ESD, and ovary, testes and effective doses by factors of 1.7, 5.2, 5.5 and 2.7, respectively.

Dose-Response Relationship, Radiation↗
PubMed2001

Necrotising fasciitis of a limb.

Between January 1992 and December 1998, we treated 24 patients with necrotising fasciitis of a limb. There were 15 men and nine women with a mean age of 59.8 years (5 to 86). The infection was usually confused with cellulitis. Exquisite pain and early systemic toxicity were the most consistent clinical features. Diabetes mellitus and hepatic cirrhosis were the most commonly associated medical diseases. One third of the patients died. Those with involvement of the limbs above the knee or elbow on admission had a significantly higher rate of mortality than those with distal lesions (Fisher's exact test, p = 0.027). There was no correlation between mortality and advanced age (Student's t-test, p = 0.22) or between amputation and survival (Fisher's exact test, p = 0.39).

Adolescent↗
PubMed2000

"Anode heel effect" on patient dose in lumbar spine radiography.

Appropriate use of the "anode heel effect" of the output beam from an X-ray tube can reduce the effective dose to patients in some common radiological examinations. We investigated the variation in radiation intensity across the X-ray beam caused by the anode heel effect, and quantified the difference in absorbed dose to critical organs resulting from lumbar spine X-ray projections carried out with the two possible orientations of the patient along the tube axis (cathode to anode). A Rando phantom and some high sensitivity thermoluminescent dosemeters (TLDs) (LiF:Mg,Cu,P) were used. With the tube axis horizontal, radiation intensity profiles, parallel and perpendicular to the axis, were measured. Lumbar spine radiographs were recorded using the Rando phantom in the standard anteroposterior (AP) and lateral projections. TLD pellets were used to measure the absorbed radiation dose at various sites corresponding to critical organ tissues (ovaries, testes, breasts, thyroid and lens). Each set of projections was recorded in two phantom orientations, first with the phantom head placed towards the cathode end of the X-ray tube, and then in the reverse direction. From the radiation intensity profile of the incident X-ray beam, the "cathode end" to "anode end" air dose ratio was found to be 1.8. In lumbar spine radiography, with the phantom head placed towards the anode end of the X-ray tube, the ovaries and testes received an average dose 17% and 12% higher, respectively, in the lateral projection, and 16% and 27% higher, respectively, in the AP projection, than those obtained in the reverse "patient" orientation. These results indicate that patients (particularly females) should always be positioned with the head placed towards the cathode end of the X-ray tube for lumbar spine radiography to achieve significant dose reductions.

Breast↗
PubMed1997

Oxidation behavior of surface-modified titanium for titanium-ceramic restorations.

STATEMENT OF PROBLEM: Titanium-ceramic bonding is an unsolved problem for the current use of titanium-ceramic restorations. PURPOSE: The purpose of the study was to characterize oxide formation on titanium surfaces at porcelain sintering temperatures and to determine the effect of chromium coating methods on titanium oxide formation. MATERIAL AND METHODS: Sputter coating and electroplating methods of chromium application were compared and combined. RESULTS: Porous, weak titanium oxide formation on uncoated samples was demonstrated at porcelain sintering temperatures. Groups with chromium coating as an oxygen diffusion barrier exhibited lower oxidation rates, except samples coated by sputtering alone. Temperature effect was found to have the greatest significance on titanium oxidation rate. The overall lowest oxidation rate was located in the group that had chromium coating by the combined coating method and was oxidized at 750 degrees C. CONCLUSION: The electroplating method requires further investigation and development so that a uniform chromium layer can be deposited on titanium.

Analysis of Variance↗
PubMed1994

Gingival absorption of triclosan following topical mouthrinse application.

This study assessed the gingival uptake and urinary excretion of triclosan in dogs following topical applications of a mouthrinse containing 0.03% of triclosan. Five different phases were conducted to define the time course of plasma concentration. The effect of plaque on gingival absorption was also measured. Phase I: Animals' teeth were cleaned of plaque via scraping. Blood sampling time was 0-2 hours. Phase II: Plaque was not removed from the animals' teeth. Blood sampling time was 0-2 hours. Phase III: Plaque was not removed from the animals' teeth. Blood sampling time was 0-6 hours. Phase IV: Plaque was not removed from the animals' teeth. Blood sampling time was 0-12 hours. Phase V: Animals' teeth were cleaned of plaque via scraping. Blood sampling time was 0-12 hours. The test substance was administered to 1 male and 1 female dog in Phases I, II, IV and V, and to 1 male dog in Phase III. The same animals were used in each phase. On the first day of each phase, the animals were treated with distilled water for a 15-minute period. The animals were exposed daily to the test material for a 15-minute period during the remaining 7 days of each phase. The test material was administered using custom-made acrylic applicator trays to enclose the maxillar premolars and molars and gingiva of one-half of the upper jaw. A leak-proof seal along the mucogingival junction and palatal mucosa was established and maintained during the exposure period.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

Wealth transfer through voluntary death.

Today, the hopelessly ill who are insured must choose between futile treatment and prolonged morbidity. Legalizing physician-assisted death for the hopelessly ill would broaden patient choice and conserve scarce resources. To ensure that the saved resources will not be re-channeled to more futile treatments for other hopelessly ill patients, those who choose dignified passage should be allowed to determine how the saving from their refusal to a prolonged death is to be re-deployed. Converting projected entitlements into death benefits at a discount would not only reduce health-care and retirements costs but improve allocation of scarce resources.

Cost Savings↗
PubMed1986

Single dose ofloxacin in treatment of uncomplicated gonorrhoea.

78 patients (66 male and 12 female) suffering from uncomplicated gonorrhoea were randomly selected to receive a single oral dose of either 400 mg or 600 mg ofloxacin. Of the 59 patients completely followed up penicillinase-producing Neisseria gonorrhoeae strains were cultured in 15 (25.4%) and the overall cure rate was 100%. Both groups showed excellent clinical effectiveness in over 80% and adverse reactions were uncommon and transient. We conclude that a single oral dose of ofloxacin in the studied dosage regimens was highly effective and safe in the treatment of uncomplicated gonorrhoea.

Adult↗
PubMed1976

Rapid GLC determination of fusaric acid in biological fluids.

A simple, sensitive GLC assay was developed for fusaric acid, the active metabolite of bupicomide, to follow the disposition of this investigational antihypertensive agent in patients undergoing therapy. Fusaric acid is efficiently extracted from biological samples, derivatized by on-column methylation, and chromatographed using flame-ionization detection. An internal standard is utilized to quantitate results. The procedure is rapid and specific for fusaric acid, and has a lower limit of sensitivity of 0.1 mug/ml. The method is suitable for supporting pharmacokinetic studies of bupicomide following therapeutic doses in animals and humans.

Body Fluids↗
PubMed1972

Phospholipid of the rat glomerular basement membrane in experimental nephrosis.

Phospholipids were found to be a constant component of rat glomerular basement-membrane preparations. The concentration fell during preparation of basement membrane by sonication of whole glomeruli, but then remained constant despite continued sonication. The proportions of the individual phospholipids were different from those of whole renal tissue or of isolated glomeruli. The basement-membrane preparations had no (Na(+)+K(+))-activated adenosine triphosphatase activity, an enzyme that is bound to plasma membranes. The concentration of lipid P was decreased on exposure in vivo or in vitro to antiserum against basement membrane; 7 days after injection of antiserum there was a change in the phospholipid composition, with a relative increase in phosphatidylcholine and a decrease in sphingomyelin content. The metabolic turnover rate of the lipid P remaining in the membrane was normal, as determined by (32)P incorporation. The loss of phospholipid was associated with decreases in the relative concentrations of hydroxyproline, hydroxylysine and glycine, and relative increases in proline, lysine, serine, threonine and valine. Administration of aminonucleoside and daunomycin produced proteinuria but did not cause a decrease in lipid P. Anticollagen and anti-lymphocyte sera that attached to the basement membrane but failed to produce proteinuria, also failed to affect the phospholipid content.

Adenosine Triphosphatases↗