PubMed Health⌕ Search

Biomedical subjects

H T Law

Publications and source records attributed to H T Law.

13 recordsLinked to original sources
PubMed2006

Management of hypertension by private doctors in Hong Kong.

OBJECTIVE: To investigate the management of hypertension by private doctors in Hong Kong. DESIGN: Self-administered questionnaire survey. SETTING: Hong Kong. PARTICIPANTS: Private doctors from all districts in Hong Kong selected by simple random sampling from the website of "The Hong Kong Doctors Homepage" from March to June 2005. MAIN OUTCOME MEASURES: Practice of blood pressure measurement and the treatment prescribed to hypertensive patients. RESULTS: A total of 225 (46%) completed questionnaires were analysed. Only 24.4% of the respondents measured blood pressure in all new patients aged above 18 years. A total of 28.0% of doctors reported that hypertensive status was unknown in over 30% of their patients prior to their first clinic visit when it was consequently diagnosed. Calcium channel blockers (31%), angiotensin-converting enzyme inhibitors (28.5%), diuretics (27.5%), and beta-blockers (21.2%) were the most commonly prescribed antihypertensive medication. Drug efficacy was the reason cited by more than half (56.9%) of doctors for selecting a given drug. Public education about hypertension was considered insufficient by 66.2% of doctors and 32% believed that self-medication would have a very significant effect on drug compliance. CONCLUSIONS: In private clinics, blood pressure measurement should become a routine procedure. There is a need to raise public awareness of hypertension.

Adult↗
PubMed2000

Cranial cruciate stability in the rottweiler and racing greyhound: an in vitro study.

An in vitro biomechanical study of cadaver stifles from rottweilers and racing greyhounds was undertaken to evaluate the contribution of the cranial cruciate ligament to stifle joint stability. This was performed at differing stifle joint angles, first with the joint capsules and ligaments intact and then with all structures removed except for the cranial cruciate ligament. Craniocaudal laxity increased in both breeds as stifle flexion increased. The rottweiler stifle showed greater craniocaudal joint laxity than the racing greyhound at all joint angles between 150 degrees and 110 degrees, but the actual increases in joint laxity between these joint angles were similar for both breeds. Tibial rotation during craniocaudal loading of the stifle increased craniocaudal laxity in both breeds during joint flexion. The relative contribution of the cranial cruciate ligament to cranial stability of the stifle joint increased as the joint flexed and was similar in both breeds.

Animals↗
PubMed2000

Comparison of the biomechanical properties of rottweiler and racing greyhound cranial cruciate ligaments.

An in vitro study of rottweiler and racing greyhound cranial cruciate ligaments revealed that the rottweiler ligaments had a significantly greater cross-sectional area at their distal attachments. Mechanical testing showed that the ultimate load related to body mass was significantly higher in the extended racing greyhound stifle during cranial tibial loading to failure, as were linear stiffness, tensile strength and tangent modulus. During ligament axis loading to failure, the only significant difference in structural and mechanical properties recorded between the two breeds was a greater ultimate strain for the greyhound ligament with the stifle joint flexed. Energy absorbed by the ligament complex at failure during cranial tibial loading was twice that for ligament axis loading for both breeds. The clinical significance is that the rottweiler cranial cruciate ligament is more vulnerable to damage as it requires half the load per unit body mass that the greyhound requires to cause a rupture.

Animals↗
PubMed1993

Temporal and spatial parameters of gait in children. I: Normal control data.

A study of the spatial and temporal parameters of gait was performed on 134 normal children, 68 boys and 66 girls, aged between three and 18 years. Normal gait showed a clear asymmetry; gait was considered to be abnormally asymmetrical if differences between left and right measurements exceeded 8 to 10 per cent. In addition, there was a definite bias comparing left and right sides, which may relate to individual laterality.

Adolescent↗
PubMed1993

Temporal and spatial parameters of gait in children. II: Pathological gait.

Temporal and spatial parameters of gait were measured in 72 children with anomalous walking patterns as a result of neuromuscular impairment, 21 with childhood hemiplegia, 27 with congenital paraplegia and 24 with miscellaneous neuromotor disorders. Measurements were compared with those for a group of normal children. In all three groups, step length, average maximum foot-velocity and walking speed were reduced, double support time was increased, while cadence deviated from normal in both directions. Hemiplegic children varied considerably in their measured side-to-side gait asymmetries, suggesting a range of gait abnormalities not specified by subjective means alone. Measured gait parameters were significantly related to Hoffer grade of functional mobility in paraplegic children. Objective gait analysis using established temporal and spatial measurements is of clinical value in the management of childhood neuromuscular disorders.

Adolescent↗
PubMed1987

Microcomputer-based low-cost method for measurement of spatial and temporal parameters of gait.

The instantaneous velocity of the forward-going foot is measured throughout the swing phase during several successive gait cycles using punched paper tapes attached to the feet. The velocity profiles thus obtained show clearly any asymmetry or departure from the normal walking pattern. The data are processed to provide the spatial and temporal parameters of gait, i.e. step lengths, stride times, double-support times, cadence and walking speed. The equipment is low-cost, easy to set up and use, and the results, which are presented on the VDU or as hard copy, are readily interpreted and related to the underlying pathology.

Biomechanical Phenomena↗
PubMed1986

In vitro measurement and computer modelling of the diffusion of antibiotic in bone cement.

The diffusion coefficient for a particular antibiotic (benzyl penicillin) in various types of bone cement has been calculated from direct measurement of the passage of radio-labelled penicillin through thin sections of cement at intervals over a period of 90 days, assuming the transport processes to be Fickian. Since the concentration gradient across the test sample is not uniform in the earlier stages of the experiment, a finite-difference approximation to the diffusion equation was used to take account of the transient behaviour in determining the coefficient. This method of analysis may also be used to predict the release, as a function of time, from the surface of antibiotic-loaded bone cement and from implanted pre-loaded PMMA beads used to provide antibiotic cover following bone or joint surgery. Our computer-generated predictions appear to agree very well with previously published figures arising from in vivo and in vitro studies and we conclude therefore, that Fick's Law accurately describes the process, even when the cement mix is inhomogeneous. We have by this means a reliable method by which the diffusion coefficients for various combinations of cement, antibiotic and other additives may be retrospectively determined and compared.

Anti-Bacterial Agents↗
PubMed1985

The effect of induced electric currents on bone after experimental osteotomy in sheep.

We have investigated the effect of currents induced by electromagnetic fields on the healing of the tibia of sheep after osteotomy, using objective and quantifiable criteria wherever possible. A battery-powered, induction apparatus was developed and was enclosed within the cast applied to the limb, so that the treated fractures received pulsed magnetic fields for 24 hours a day while the animals were freely mobile. In all, 13 sheep were treated and 13 were used as controls. The response was assessed by radiography of the limb and of the excised bone, by histology, including measurement of the areas of callus, fibrocallus and cortical bone, and by measurement of the uptake and extraction of bone-seeking mineral. All the bones healed and no statistically significant differences between the treated animals and the controls were discovered except (at only P less than 0.05) in the uptake of bone-seeking mineral; this increased more rapidly in treated animals over the two to three weeks after osteotomy, although at six weeks the uptake in both groups was the same.

Animals↗
PubMedDate not supplied

Assessment of abnormalities of gait in children from measurements of the instantaneous foot velocities during the swing phase.

A new gait analysis system is described which is microcomputer-based, of low cost and both suitable for and acceptable to children with neurological motor disorders. A variety of different gait abnormalities and neurological conditions have been analysed and quantitative gait information is illustrated from this equipment which provides, after a short walk, an immediate profile of the objective measurements of the main spatial and temporal parameters of the gait cycle, i.e. step length, stride time, double support time, cadence, average walking speed and maximum velocity of the foot during the swing phase.

Adolescent↗