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Biomedical subjects

C S Ho

Publications and source records attributed to C S Ho.

At least 55 records · Page 3Linked to original sources
PubMed1999

Considerations regarding real time off-site monitoring.

This article presents a discussion of some issues that require special design consideration involving real time off-site monitoring. "Off-site" refers to a patient monitored away from the location of a health care professional (HCP) responsible for the patient's care. "Real time" refers to a minuscule delay between sensing, recording and transmitting a signal to a distant site. With the current health care climate it is foreseen that more patients are and will be monitored in real time and off-site (e.g. home, long term care). Special considerations are given to issues of signal robustness, false alarms, procedures to respond to an alarm, and appropriate response time. Each of these issues is discussed, as is the proposed approach, based on common sense and knowledge available in the public domain. To maximize patient safety, this approach includes carefully selected indications and target population, back-up communication equipment, and identification of an emergency response process.

Electrocardiography, Ambulatory↗
PubMed1998

Cerebral perfusion in children with Alice in Wonderland syndrome.

Alice in Wonderland syndrome (AIWS) is characterized by visual hallucinations and bizarre perceptual distortions. Technetium-99m hexamethylpropyleneamine tomography (SPECT) brain scans were performed in four patients during the acute stage of AIWS. Two patients were demonstrated to have Epstein-Barr virus infections. One had abnormal (EEG) findings. The visual-evoked potential, cranial CT, and MRI findings were negative. The decreased cerebral perfusion areas in all patients were near the visual tract and visual cortex. All involved some regions of the temporal lobe. In most patients with AIWS, the EEG, CT, and MRI are unable to determine the precise pathologic areas. However, a SPECT brain scan may demonstrate abnormal perfusion areas and explain the clinical presentations.

Cerebrovascular Circulation↗
PubMed1998

Kartagener's syndrome: a re-visit with Chinese perspectives.

The objective of this study was to evaluate the clinical, radiological investigation profiles, and ciliary function and ultrastructure in Chinese patients with Kartagener's syndrome (presence of dextrocardia, sinusitis and bronchiectasis). All patients with dextrocardia were assessed for the presence of sinusitis and bronchiectasis in our hospital network. Patients identified with Kartagener's were assessed when they were at steady state for their bronchiectasis. Seven cases (4 males; mean age 34.9 years) were identified and systematically reviewed. The mean 24 h sputum volume was 26.6 +/- 32.77 mL/day and the patients suffered from a mean of 2.9 exacerbations/year. Nasal symptoms (anosmia in one, obstruction in six and persistent discharge in three patients) were common. Only two cases (1 M) were married and both had normal fertility. Lung function assessment showed a mean FEV1/FVC of 83.3 +/- 38.78/86.5 +/- 36.72 (% predicted) with little reversibility. High resolution computerized tomography (HRCT) revealed bronchiectactic involvement of the lower lobes in seven and middle lobe/lingula in four cases. Assessment of alpha-1-anti-trypsin, aspergillus precipitins, auto-antibodies and serology for Pseudomonas pseudomallei was normal. Sputum culture yielded Pseudomonas aeruginosa in three, Haemophilus influenzae in three and commensals in one case. Phase contrast microscopy assessment of respiratory cilia, obtained by brushing the inferior turbinate, revealed that most of the mucosa was unciliated. The mean ciliary beat frequency was 5.2 +/- 6.76 Hz (range 0-13.7; normal range 12-18 Hz). Four patients had immotile cilia whilst the rest had normal ciliary movement. Transmission electron microscopy showed the absence of dynein arms in four patients. The results of this study show that patients with Kartagener's syndrome may have normal ciliary ultrastructure and the absence of dynein arms is not necessarily associated with ciliary immotility. The presence of ciliary immotility might have prognostic value as these patients appear to have more active bronchiectasis. Our experience on this series should help clinicians in the investigation and management of these patients.

Adolescent↗
PubMed1998

Clinical profiles of Chinese patients with diffuse panbronchiolitis.

BACKGROUND: Diffuse panbronchiolitis (DPB), characterised by progressive sinobronchial sepsis, is well characterised in Japanese subjects but not in other ethnic groups. The experience with DPB in seven Chinese patients is described and the clinical profiles compared with those of Japanese subjects. METHODS: Seven Chinese patients (three women; mean (SD) age 48(18.6) years, all never smokers) who attended a teaching hospital centre and fulfilled the diagnostic criteria for DPB were assessed prospectively for clinical, radiological, lung function, microbiological, and other "characteristic" laboratory parameters. RESULTS: Lung function assessment showed a typical obstructive pattern (n = 5) and air trapping (n = 7). Typical bronchiolar infiltration by lymphocytes and plasma cells and accumulation of foamy macrophages in the intraluminal tissue were detected in open lung biopsy specimens (n = 2). Chest radiographs and high resolution computed tomographic scans revealed hyperinflation, diffuse nodules, bronchial thickening and dilatation, peripheral hypoattenuation, and bronchiolectasis. Radiological improvement, manifest as a reduction in nodular density and bronchial thickening, and persistence of other abnormalities such as air trapping were not accurately depicted by the classical Nakata or Akira classifications. The other "characteristic" features such as HLA-B54, IgG subclass deficiency, raised CD4/CD8 T lymphocyte ratio, cold haemagglutinaemia, raised IgA, IgG, and rheumatoid factor were not present. Treatment with erythromycin led to excellent responses in symptoms, lung function indices, and the radiological picture. A review of the non-Japanese cases in the literature reveals that this absence of typical "additional features" in DPB might also be applicable to non-Japanese patients. CONCLUSIONS: We report the only series of non-Japanese Mongoloid patients with well characterised DPB who had uncharacteristic investigation profiles. This experience should help other clinicians in the investigation and management of DPB in non-Japanese patients.

Adult↗
PubMed1998

Inhaled fluticasone reduces sputum inflammatory indices in severe bronchiectasis.

Although corticosteroid therapy might be clinically beneficial for bronchiectasis, very little is known of its effects on the inflammatory and infective markers in bronchiectasis. We have therefore performed a double-blind, placebo-controlled study to evaluate the effects of a 4-wk administration of inhaled fluticasone in bronchiectasis. Twenty-four patients (12 female; mean age 51 yr) were randomized into receiving either inhaled fluticasone (500 microgram twice daily) via the Accuhaler device (n = 12) or placebo. At each visit, spirometry, 24-h sputum volume, sputum leukocyte density, bacterial densities, and concentrations of interleukin (IL)-1beta, IL-8, tumor necrosis factor-alpha (TNF-alpha), and leukotriene B4 (LTB4) were determined. There was a significant (p < 0.05) decrease in sputum leukocyte density and IL-1beta, IL-8, and LTB4 after fluticasone treatment. The fluticasone group had one and the placebo group three episodes of exacerbation. There were no significant changes in spirometry (p > 0.05) or any reported adverse reactions in either group. The results of this study show that high-dose fluticasone is effective in reducing the sputum inflammatory indices in bronchiectasis. Large-scale and long-term studies are indicated to evaluate the effects of inhaled steroid therapy on the inflammatory components in bronchiectasis.

Administration, Inhalation↗
PubMed1998

Pleural fluid pseudouridine in malignant and benign pleural effusions.

Pseudouridine in urine and plasma has been proved to be a useful tumour marker in many malignant conditions. We studied its usefulness in pleural fluid for distinguishing malignant from non-malignant pleural effusions. Pleural fluid pseudouridine concentrations in different groups of patients with pleural effusion (31 malignant, 29 benign, 16 unknown, 1 double pathology) was measured and compared. Its usefulness in distinguishing malignant from non-malignant pleural effusions was analysed by receiver-operating characteristic (ROC) curve analysis. Pseudouridine concentrations in the malignant group were significantly higher than the non-malignant group (P < 0.017, Bonferroni adjustment) with values overlapping extensively at the lower end. The area-under-the curve (AUC) value in the ROC curve analysis was 0.675 (P < 0.05). We conclude that the pleural fluid pseudouridine is of limited clinical value in distinguishing malignant from non-malignant pleural effusion due to its extensive overlap. However, it is useful when the concentration is higher than 65 mumol/L, which indicates malignancy.

Area Under Curve↗
PubMed1998

The effect of Pseudomonas aeruginosa infection on clinical parameters in steady-state bronchiectasis.

STUDY OBJECTIVE: To investigate the effect of Pseudomonas aeruginosa infection on clinical parameters in Chinese patients with noncystic fibrosis and steady-state bronchiectasis. DESIGN: Prospective, cross-sectional clinicomicrobiological study with informed consent. SETTING: Consecutive outpatient recruitment from a specialist bronchiectasis respiratory clinic. PATIENTS: Outpatients (n = 100; 62 women; 55.1+/-16.7 years old; FEV1/FVC 1.4+/-0.7/2.1+/-0.9 L), who had stable respiratory symptoms for more than 3 weeks. MEASUREMENTS AND RESULTS: Respiratory pathogens isolated from the sputum were: Pseudomonas aeruginosa (33), Haemophilus influenzae (10), Moraxella catarrhalis (2), other Gram-negative bacilli (5), Streptococcus pneumoniae (6), Staphylococcus aureus (5), mycobacteria (3), and yeast (1). Clinical parameters in patients with positive isolation of P aeruginosa were compared with those without the organism in the sputum culture (non-P aeruginosa). In the P aeruginosa group, the FEV1/FVC ratio and sputum volume were lower (p < 0.005) and higher (p < 0.0001), respectively, than those of the non-P aeruginosa group. The FEV1/FVC ratio (< 60%) and sputum volume (grading > 5) were independently associated with a positive sputum isolation of P aeruginosa with odds ratios of 3.1 (confidence interval [CI] 1.2 to 8.4; p < 0.01) and 4.7 (CI 1.6 to 13.3; p < 0.001), respectively. CONCLUSIONS: P aeruginosa is the predominant respiratory pathogen isolated in the sputum of Chinese patients with steady-state bronchiectasis, and its isolation is associated with high sputum output (> or = 75th quartile) and moderately severe airflow obstruction (FEV1/FVC < 60%).

Adult↗
PubMed1998

Effect of head-out water immersion on serum sodium transport inhibitor and urinary nonadrenaline excretion in pre-menopausal women.

The effect of head out water immersion on the excretion of catecholamines and serum sodium transport inhibitor (STI) was studied in healthy young women during the follicular and leuteal phases. Two way ANOVA showed that menstrual cycle had no effect on the excretion of noradrenaline (NA), dopamine (DA) or serum STI. Analysis of pooled data from follicular and leuteal phases showed that immersion caused a significant increase in sodium excretion and serum STI and a significant decrease in urinary NA excretion in healthy young women. After immersion, sodium excretion, DA excretion and serum STI decreased and NA increased.

Adolescent↗
PubMed1997

Pleiotropic effects of a disrupted K+ channel gene: reduced body weight, impaired motor skill and muscle contraction, but no seizures.

To investigate the roles of K+ channels in the regulation and fine-tuning of cellular excitability, we generated a mutant mouse carrying a disrupted gene for the fast activating, voltage-gated K+ channel Kv3.1. Kv3.1-/- mice are viable and fertile but have significantly reduced body weights compared with their Kv3.1+/- littermates. Wild-type, heterozygous, and homozygous Kv3.1 channel-deficient mice exhibit similar spontaneous locomotor and exploratory activity. In a test for coordinated motor skill, however, homozygous Kv3.1-/- mice perform significantly worse than their heterozygous Kv3.1+/- or wild-type littermates. Both fast and slow skeletal muscles of Kv3.1-/- mice are slower to reach peak force and to relax after contraction, consequently leading to tetanic responses at lower stimulation frequencies. Both mutant muscles generate significantly smaller contractile forces during a single twitch and during tetanic conditions. Although Kv3.1-/- mutants exhibit a normal auditory frequency range, they show significant differences in their acoustic startle responses. Contrary to expectation, homozygous Kv3.1-/- mice do not have increased spontaneous seizure activity.

Age Factors↗
PubMed1997

Effect of high salt intake on plasma and tissue concentration of endogenous ouabain-like substance in the rat.

The effect of high salt intake on serum concentration and tissue distribution of ouabain-like substance (OLS) was examined in rats. Sprague-Dawley rats (n=8) were placed on a high salt diet by the inclusion of 1.8% sodium chloride in drinking water for 7 days and a 'control' group (n=8) was maintained on normal drinking water during the study period. Serum and tissue OLS was measured by radioimmunoassay after solid phase extraction. High salt intake significantly increased serum OLS concentration (1.43 +/- 0.06 vs 1.14 +/- 0.05 nmol/L; mean +/- SEM, P=0.002). In both groups, the adrenal showed significantly (p < 0.001) higher OLS content compared to liver, kidney, heart and brain. HPLC of rat serum extract resolved a major peak with a retention time identical to that of standard ouabain, further confirming the nature of OLS. We conclude that high salt intake increases endogenous production of OLS, which appears to originate from the adrenal gland in the rat.

Animals↗
PubMed1997

Development of phonological awareness of Chinese children in Hong Kong.

Three studies were conducted in Hong Kong to examine the development of phonological awareness of Chinese children from the ages of 3 to 8. Like English-speaking children, Chinese children were found to be able to detect relatively large sound segments (e.g., partial homophones) at the beginning and gradually progress to smaller sound segments (e.g., rhymes and tones). Tasks detecting onsets and rhymes in a "similarity format" were found to be easier for Chinese children than those in an "oddity format." In addition, cross-linguistic comparisons indicated that Chinese children develop an awareness of initial consonants and rhymes later than their English counterparts. The possible impact from differences in the oral and written languages between Chinese and English are also discussed.

Age Factors↗
PubMed1997

Phonological skills are important in learning to read Chinese.

A 4-year longitudinal study was conducted to examine the relationship between Chinese children's phonological skills and their success in reading. Initially, 100 Hong Kong Chinese children were tested on visual and phonological skills at the age of 3, before they could read. The findings showed that prereading phonological skills significantly predicted the children's reading performance in Chinese 2 and 3 years later, even after controlling for the effects of age, IQ, and mother's education. The main reason for this relationship is that phonological knowledge helps children to use the phonetic component in Chinese characters.

Child↗
PubMed1997

Effect of carbidopa on the excretion of sodium, dopamine, and ouabain-like substance in the rat.

The effect of carbidopa, a competitive inhibitor of dopamine synthesis on the excretion of sodium, dopamine (DA), and endogenous sodium transport inhibitor (ESTI), was examined in rats on normal and high salt diets for 7 days. ESTI activity was measured (1) as ouabain-like substance (OLS) by radioimmunoassay using an antibody raised against ouabain, (2) by inhibition of purified Na+,K+-ATPase activity (ATPI), and (3) as digoxin-like substance (DLS) using a commercial digoxin assay. The OLS immunoassay was validated against rubidium transport studies. High salt diet caused an increase in OLS and ATPI but not DLS. Sodium excretion in rats on normal sodium intake was not affected by carbidopa treatment but was significantly lower in the high sodium diet group during the first 5 days of the study. In the low salt group, carbidopa treatment caused significant increases in OLS. We conclude that ESTI (measured as OLS) and DA are important in the natriuresis of salt loading.

Analysis of Variance↗