PubMed Health⌕ Search

Biomedical subjects

Y L Yu

Publications and source records attributed to Y L Yu.

At least 37 records · Page 2Linked to original sources
PubMed1992

Huntington's disease in Chinese: a hypothesis of its origin.

The period prevalence (1984-91) of Huntington's disease (HD) in Hong Kong Chinese was 3.7 per million population. HD patients in Mainland China and Hong Kong showed similar hereditary pattern, clinical and pathological features as in the West. Chinese HD patients were male predominant with a younger age of onset and death. Their ancestral origin could be traced mostly to the coastal provinces of China. It is proposed that Chinese HD patients may have a European origin and share the same gene pool as their white counterparts.

China↗
PubMed1992

Treatment of acute cerebral hemorrhage with intravenous glycerol. A double-blind, placebo-controlled, randomized trial.

BACKGROUND AND PURPOSE: Hitherto, treatment of acute cerebral hemorrhage with intravenous glycerol has not been evaluated in rigorous clinical studies with sufficient patient numbers. METHODS: We undertook a double-blind, stratified and randomized, placebo-controlled clinical trial. Only patients with a first stroke admitted to the hospital within 24 hours after onset of symptoms were recruited, provided computed tomography confirmed hemorrhage and informed consent was obtained. After stratification into alert, semicoma, and coma subgroups using the Glasgow Coma Scale, 107 patients received active treatment (500 ml of 10% glycerol in saline by intravenous infusion over 4 hours on 6 consecutive days) and 109 were given corresponding saline treatment. Using a variety of objective scoring systems, patients were followed up for up to 6 months. RESULTS: At follow-up, all measures of outcome in the treated and control groups were very similar. At 6 months, respective mortality rates were 37 of 107 and 33 of 109. Corresponding mean +/- SD improvements in Scandinavian Stroke Study Group scores were 8.35 +/- 16.9 versus 11.55 +/- 15.6 (long-term) and 0.64 +/- 7.3 versus 2.40 +/- 6.9 (prognostic), and improvements in the Barthel Index ratings were 10.72 +/- 24.7 versus 13.95 +/- 23.3, respectively. Glasgow Coma Scale score improvements in the survivors were 0.81 +/- 1.5 and 1.16 +/- 1.7 in the treated and control groups, respectively. Hemolysis (generally subclinical) was the only adverse effect of glycerol noted. CONCLUSIONS: In the absence of any clinically or statistically significant difference in outcome between the treated and control groups, this trial provides no justification for glycerol therapy following acute cerebral hemorrhage.

Acute Disease↗
PubMed1992

Postinfectious myelitis, encephalitis and encephalomyelitis.

Six cases of post-infectious encephalomyelitis are described. A preceding non-specific viral-like illness occurred 4 to 20 days before the onset of the neurological deficits. The clinical syndromes included transverse myelitis, focal encephalitis and encephalomyelitis (each in one case) and diffuse encephalitis in 3. Magnetic resonance imaging appeared to be the investigation of choice. High dose corticosteroids were given to 4 patients who recovered partially or fully. The patient with focal encephalitis had a spontaneous and complete recovery. The remaining patient with diffuse encephalitis died 3 days after the onset; autopsy showed prominent lymphocytic perivascular cuffing in the white matter and lymphocytic infiltration of the meninges.

Adrenal Cortex Hormones↗
PubMed1992

Effects of thyroidectomy on the hematocrit and blood viscosity in ovariectomized rats.

The hematocrit and blood viscosity were measured in ovariectomized (Ovx) rats following thyroidectomy or sham operation. Rats were thyroidectomized (Tx) or sham Tx immediately after ovariectomy. Three months later, Ovx, Ovx+Tx, and intact rats at proestrus stage were bled. Blood was collected by heart puncture in rats under ether anesthesia and heparinized. One month after the first bleeding, Ovx and Ovx+Tx rats were bled once again. the viscosity of whole blood and plasma was measured at various shear rates at 37 degrees C by means of a Mooney-Ewart viscometer. The hematocrit was determined by a microhematocrit centrifuge. The plasma osmolality was measured by a computerized micro-osmometer. Concentrations of plasma sodium and potassium were measured by a flame photometer. The concentration of plasma thyroid stimulating hormone (TSH) was measured by a radioimmunoassay. In Ovx+Tx rats, the plasma TSH concentration was higher, but the hematocrit and blood viscosity were lower than those in Ovx and proestrus rats. The levels of plasma sodium, osmolality and viscosity were not altered by ovariectomy and thyroidectomy. These results suggest that the lower blood viscosity in thyroidectomized rats is due to a reduction of hematocrit.

Animals↗
PubMed1991

Relative quantification of collagen mRNA in fibroblasts by a radioactive polymerase chain reaction technique.

A radioactive polymerase chain reaction (PCR) method has been developed for the relative quantification of the human alpha-2 chain of type I collagen [hu alpha-2(I)] in cells. cDNAs generated by reverse transcription from the total pool of cytoplasmic RNA serve as a template for polymerase chain reaction amplification of a hu alpha-2(I) cDNA primed by two sequence-specific synthetic oligonucleotides. The distinctive 390 bp hu alpha-2(I) cDNA and two Aval fragments of 220 and 170 bp are identified by agarose gel electrophoresis. alpha-32P-dCTP of defined specific activity is included in the PCR reaction and the 390 bp cDNA is excised from the electrophoresis gel to permit direct radioactive quantification of hu alpha-2(I) mRNA. The amount of hu alpha-2(I) mRNA expressed in as few as 111 fibroblasts was determined reliably. In contrast, the hu alpha-2(I) mRNA from at least 5 x 10(5) fibroblasts was required for detection by Northern blot analysis developed with the same cDNA probe radiolabelled with alpha-32P-dCTP by random priming. Human bronchoalveolar lavage (BAL) fluids of six patients with fibrosing lung diseases stimulated the level of expression of hu alpha-2(I) mRNA in cultured human fibroblasts as determined by this technique. The radioactive PCR method thus quantifies hu alpha-2(I) mRNA in fibroblasts with sufficient sensitivity to study fibroblast activation in vitro and detect fibroblast stimuli in human clinical samples.

Autoradiography↗
PubMed1991

Cerebral haemorrhage in anticoagulated patients with non-septic mechanical valvular prosthesis.

Cerebral haemorrhage in anticoagulated patients with mechanical valvular prosthesis poses an uncommon but difficult management problem. Four such patients are presented: one patient had delayed haemorrhagic transformation of a preexisting cerebral infarct, one probably had de novo haemorrhage complicating hypertension and in two patients cerebral haemorrhage was associated with excessive anticoagulation. Conservative management including the use of fresh frozen plasma, delayed heparinisation and warfarinisation was used. Both patients with anticoagulant overdose died as a result of extensive haemorrhage despite the drainage of cerebellar haematoma in one patient. The remaining two patients survived with minimal neurological deficits. Diagnosis of the underlying cause of cerebral haemorrhage, and the timing of heparinisation and anticoagulation are discussed.

Adult↗
PubMed1991

High prevalence of undiagnosed diabetes among Chinese patients with ischaemic stroke.

We reviewed the prevalence of diabetes mellitus, hypertension and cigarette smoking in 176 Chinese patients with acute stroke, classified, on computed tomographic findings, as intracerebral haemorrhage or cerebral infarction. In all patients with no known history of diabetes, a 75 g OGTT was done 3-6 months after ictus and interpreted using WHO criteria. The overall prevalence of diabetes and impaired glucose tolerance (IGT) was 33.5% and 21.0%, respectively, with a higher prevalence being found in patients with cerebral infarction (P less than 0.05). Forty percent of those with diabetes were previously undiagnosed - all but 2 had ischaemic stroke. Compared to reported findings in the general population, an increased prevalence of hypertension, and possibly also cigarette smoking was found in patients with both stroke categories. On the other hand, significant hypercholesterolaemia was not found in patients of either category. In view of the high prevalence of undiagnosed diabetes among these stroke patients and the increased morbidity and mortality associated with diabetes mellitus, screening for diabetes is recommended especially in those with ischaemic stroke. If a fasting plasma glucose of greater than or equal to 6 mmol/l was used for the initial screening of undiagnosed diabetes in this group of patients, the sensitivity and specificity values would have been 78% and 94%, respectively. Whether this cut-off value can be cost-effectively employed for mass screening remains to be confirmed by studies involving larger numbers of stroke patients.

Blood Glucose↗
PubMed1991

A multimodal neurophysiological assessment in terminal renal failure.

A prospective multimodal neurophysiological study was conducted on 36 patients with end-stage renal failure, 16 of whom subsequently underwent renal transplantation (TR). Nerve conduction study and somatosensory evoked potentials revealed that peripheral conduction deficit, often subclinical, was the commonest abnormality, and TR resulted in substantial improvement. Visual evoked potentials demonstrated subclinical impairment, which did not improve after TR. The brainstem auditory evoked potentials were essentially normal and unaffected by TR.

Brain Stem↗
PubMed1991

Neurological manifestations of systemic lupus erythematosus: a prospective study.

A prospective study of the neurological manifestations in all patients with systemic lupus erythematous (SLE) was conducted between February 1985 to January 1989. Excluding herpes zoster infection of peripheral or cranial nerves, post-herpetic neuralgia and migraine, 36 neurological episodes occurred in 33 patients. The presenting symptoms were mental confusion (10), psychosis (five), seizures (six), focal neurological deficit (three), coma (two), headache (five), blurring of vision (three), neuropathy (one) and myelopathy (one). Of these manifestations, only eight episodes were due to primary involvement by SLE: psychosis (two), seizure (two), multiple cerebral infarcts (one), papillitis (one), neuropathy (one) and myelopathy (one). Infection was the most common secondary cause of neurological episodes: all 10 episodes of mental confusion (fungal seven, pyogenic two, tuberculous one, nocardial one); two of six seizures (tuberculous one, pyogenic one); all five headaches (tuberculous meningitis three, cryptococcal meningitis two). The other secondary causes included steroid psychosis (two), hypertensive encephalopathy with seizure (one) and hypertensive retinopathy (one). Three of five cases of focal neurological deficit were due to macrovascular disease rather than to vasculitic infarction. We concluded that cerebral psychosis was a relatively rare presentation in our patients with SLE. In patients who presented with a neurological problem, especially mental confusion, efforts should be made to ascertain the underlying cause, especially if this may be an infection.

Adult↗
PubMed1991

Pattern of memory deficits in a controlled psychometric study of thalamic haemorrhage.

Twelve patients with unilateral thalamic haemorrhages were assessed psychometrically. The results were compared with control subjects matched for sex, age and years of education. The pattern of deficits and preserved abilities cannot be explained in terms of semantic/episodic distinction, but could be interpreted as manifestations of disconnection between the frontal and temporal systems.

Aged↗
PubMed1990

Investigation of intravascular haemolysis during treatment of acute stroke with intravenous glycerol.

1. In patients with acute strokes entering a large ongoing randomised double-blind controlled trial of intravenous glycerol therapy, the extent and pathogenesis of any ensuing haemolysis were evaluated using standard clinical investigations and in vitro techniques. 2. Twenty patients received 10% glycerol in saline (500 ml over 4 h on 6 consecutive days) and 15 received corresponding control treatment with saline. 3. Intravascular haemolysis was evident after the first infusion; compared with the controls the glycerol group had i) a greater mean reduction in serum haptoglobin concentration (P less than .05), and ii) a greater proportion exhibiting haemoglobinaemia (P = 0.03). 4. After 6 days of glycerol treatment, the mean reduction in haemoglobin concentration was only 0.8 g more than in controls; this difference being neither clinically nor statistically significant. 5. Glycerol therapy was not associated with haemoglobinuria, renal insufficiency or disseminated intravascular coagulation. 6. Exposure of red blood cells to 1-10% glycerol in vitro did not induce haemolysis per se; on re-exposure to lower concentrations lysis ensued provided a minimum osmotic gradient was present. 7. Whilst taking standard dosage regimes of glycerol, the stroke patients we studied manifested a degree of intravascular haemolysis but its consequences were not clinically significant; lysis probably ensued after venous blood acquiring high glycerol concentrations mixed with blood containing little or no glycerol.

Acute Disease↗
PubMed1990

Cerebrovascular disease in Hong Kong Chinese.

Our prospective study of cerebrovascular disease in Hong Kong confirms a previous clinical impression that stroke in the Chinese has a pattern different from that in Caucasians. We studied 540 patients (aged 20-70 years) with stroke. Computed tomography or autopsy was obtained in 86.1% and showed an increase in the proportion with lacunar infarction, striatocapsular infarction, and parenchymal hemorrhage relative to the frequencies in Caucasians. This increase in the incidence of cerebral hemorrhage occurs not only in semicomatose and comatose patients but also in alert patients (16.9%) and those with a lacunar syndrome (12.5%). Our findings suggest that cerebrovascular disease in the Chinese selectively affects small vessels, causing lacunes and hemorrhages. In future community studies on stroke prevalence, researchers should be cautious about interpreting similar prevalence rates as reflecting similar risk factors or pathologies.

Adult↗
PubMed1990

Cerebral thrombosis in beta-thalassemia/hemoglobin E disease.

We describe two Chinese patients with beta-thalassemia/hemoglobin E disease who developed cerebral infarction due to occlusion or stenosis of their extracranial carotid arteries. The roles of platelet abnormalities and other factors in this condition are discussed.

Adult↗