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Biomedical subjects

M S Ip

Publications and source records attributed to M S Ip.

54 records · Page 3Linked to original sources
PubMed1993

Rheumatoid nodules in the trachea.

We describe the first case of endotracheal rheumatoid nodules in a 45-year-old Chinese man with rheumatoid arthritis. He developed exacerbation of polyarthritis, new subcutaneous nodules and fibrosing alveolitis. At bronchoscopy, four whitish nodules were detected at the tracheal wall, and biopsy showed fibrinoid necrosis, palisaded inflammatory cell infiltrate and vasculitis, consistent with rheumatoid nodules. Both tracheal and subcutaneous nodules regressed with orally administered prednisone.

Arthritis, Rheumatoid↗
PubMed1993

An audit of antiasthmatic drug inhalation technique and understanding.

Inhaled rather than oral antiasthmatic therapy is accepted as more advantageous but depends on patient technique and understanding. In 74 asthmatic outpatients, technique using metered-dose inhaler (MDI) was poor; in 56 patients inhaling beta-agonist, the mean peak expiratory flow rate (PEFR) increase was only 15 L/min (6%) greater than in 18 controls, p < 0.05, 95% confidence intervals 2-27 L/min or 2-11%. Tilting the head back and actuation "stopping" inspiration produced the least favorable PEFR responses; taken together, regression analysis yielded a statistically significant negative correlation with absolute or percentage PEFR change (R2 = 0.15; p < 0.02). Patients were unclear about which drugs to inhale as required or regularly. Among 19 patients reassessed inhaling beta-agonist, only 8 had baseline PEFR values within 10% of each other during both assessments. In the latter, the mean postinhalation PEFR increase was 36 L/min (or 13%) greater than the corresponding increase (or % change) at first assessment, p = 0.05 (0.08), 95% confidence intervals 0-73 L/min (-2 to 29%). Thus, MDI users should avoid tilting the head back, actuation stopping inhalation, and be more aware of prophylactic (steroid) versus symptomatic (beta-agonist) treatment.

Administration, Inhalation↗
PubMed1993

Trends in asthma therapy in Hong Kong, 1987-1992.

To audit the clinical practice in drug treatment of bronchial asthma in Hong Kong, two questionnaire surveys were conducted in 1987 and 1992. The questionnaire was adapted from the 1984 European Audit. The response rate was 40% (248 of 615 mailings) in 1987 and 32% (207 of 652 mailings) in 1992. A total of 86% and 87% of responders were general practitioners (GP), respectively, and the others were chest physicians (CP). For treatment of acute severe asthma in adults, parenteral aminophylline was the first drug used by GP in 1987, whereas inhaled beta-agonist was used in 1992. Parenteral steroid was more often used by both GP and CP in 1992. In children, inhaled beta-agonist was always the first choice and parenteral steroid ranked higher in 1992, overtaking parenteral aminophylline. For maintenance therapy of chronic asthma in adults, inhaled beta-agonist ranked first in both surveys. Inhaled steroid has become much more popular with GP, ranking second in 1992, overtaking oral bronchodilators. With CP, inhaled steroid was already ranking second in 1987, and it was used as the first drug, as frequently as inhaled beta-agonist, in 1992. In children, in 1987, inhaled beta-agonist was the first drug of choice, and prophylactic drugs ranked lower than oral bronchodilators with both GP and CP. In 1992, cromoglycate and inhaled steroids were much more often used, so much so that among CP, inhaled steroid ranked first, just ahead of inhaled beta-agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1992

Myasthenia gravis in Hong Kong Chinese. 1. Epidemiology and adult disease.

A territory-wide study of myasthenia gravis (MG) was conducted in Hong Kong. Two hundred and sixty-two Chinese patients (159 adult and 103 paediatric onset) were identified, corresponding to a point prevalence and period prevalence of 53.5 and 62.2 per million respectively, and an average annual incidence of 4.0 per million population. Nine patients died, 7 from MG, giving a case fatality rate of 0.027. Female predominance was present in the whole group of patients (female to male ratio 1.6:1) and in those with adult disease (ratio 2.1:1), but not in those with onset in childhood (ration 1.1:1). Onset of disease was most common in the first 3 decades of life, and became less common in subsequent decades. Juvenile onset MG occurred in 39.3% of patients and restricted ocular MG in 47.9%. Familial occurrence was found in 5 patients. In the 159 adult onset patients, ocular disease was most common (32.7%), followed by mild generalised (29.6%), moderately severe generalised (24.5%), fulminating (11.9%) and late severe disease (1.3%). The mean age of onset of symptoms was 36.7 years. The symptomatology was similar to that of Caucasoid populations. Autoimmune thyroid disease was the commonest associated disease, and the incidence of thymoma among thymic abnormalities was high at 38%.

Adolescent↗
PubMed1992

High prevalence of asthma in patients with bronchiectasis in Hong Kong.

Eighty five Chinese patients with diffuse or localized bronchiectasis (non-cystic fibrosis) were studied regarding the prevalence of asthma. Twenty three of the 85 had concomitant asthma, diagnosed by history and reversibility on lung function testing either spontaneously or after bronchodilator. None fulfilled the diagnostic criteria of allergic bronchopulmonary aspergillosis (ABPA). Asthma preceded the onset of bronchiectasis in 13 patients and developed after long duration of bronchiectasis in seven, while the temporal onset could not be differentiated in three patients. Patients with both asthma and bronchiectasis had inferior spirometric values, higher prevalence of bronchial hyperresponsiveness to methacholine, higher prevalence of skin atopy, elevated serum immunoglobulin E (IgE), and more sputum eosinophilia, compared with their non-asthmatic counterparts. Possible mechanisms by which asthma and bronchiectasis predispose to each other include asthmatic obstruction contributing to development of bronchiectasis, and sensitization of airways with increased lability due to microbial colonization of the ectatic bronchial tree.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1991

Effect of phosphatidylcholine on ultrafiltration in patients on continuous ambulatory peritoneal dialysis.

Oral phosphatidylcholine at 900 mg/day was given to 4 patients with high lymph absorption for 8 weeks. Fluid and solute transfer before and after treatment were compared to 4 similar controls given placebo. None of the patients had overt ultrafiltration problems. After treatment, overnight peritoneal effluent phospholipid content did not change significantly. Ultrafiltration as well as solute and glucose transfer remained unchanged at the end of 8 weeks. A controlled trial on patients with overt ultrafiltration problems for a longer duration is required to further elucidate the role of phosphatidylcholine supplementation in patients on continuous ambulatory peritoneal dialysis.

Absorption↗
PubMed1991

1,25-Dihydroxycholecalciferol and peritoneal macrophage chemotaxis in patients on continuous ambulatory peritoneal dialysis.

Single graded doses of 1,25-dihydroxycholecalciferol of 2 and 4 micrograms were added intraperitoneally into the overnight 1.5% glucose dialysate of 6 patients on continuous ambulatory peritoneal dialysis. The effect on peritoneal macrophage chemotaxis and random migration was studied and compared with the baseline when no 1,25-(OH)2D3 was added. No consistent effect on peritoneal macrophage chemotaxis was observed. Random migration was significantly depressed at 4 micrograms when compared with baseline (5.4 +/- 1.9 vs. 12.2 +/- 3.7 cells/high-power field, p less than 0.05). The potential clinical role of 1,25-(OH)2D3 as an immune modulator requires further study.

Adult↗
PubMed1991

Factors affecting lymphatic absorption in Chinese patients on continuous ambulatory peritoneal dialysis (CAPD).

The pathways and physiology of lymph absorption (LA) from the peritoneal cavity are well documented; however, much uncertainty still exists as to the various clinical and demographic factors affecting LA. We studied LA measured by the albumin instillation method, in adult Chinese CAPD patients, and showed that it was independent of age, sex, body surface area, duration of dialysis, intrinsic renal disease, use of intraperitoneal drugs (heparin/antibiotics/deferroxamine) and frequency of past bacterial peritonitis. High lymph absorbers had a relatively higher transcapillary cumulative ultrafiltration than low lymph absorbers. An enhanced LA was associated with a high initial intraperitoneal volume. Assessment of diaphragmatic strength by the decrement in vital capacity on changing from an erect to a supine position failed to distinguish patients with high and low LA.

Diaphragm↗
PubMed1990

Rising asthma mortality in young males in Hong Kong, 1976-85.

The trend in asthma mortality in Hong Kong was estimated from published statistics for the years 1976-85. To avoid coding errors in death certifications, only asthma deaths in the age group 5-34 years were analysed. Mortality rose annually by an average of 10.5% in male (P less than 0.02), but not female asthmatics. Such an increase was not due to a change in coding as a result of the revision of the International Classification of Diseases in 1979, or an exchange of diagnostic labelling from other respiratory diseases. The exact causes for the increase in asthma mortality have yet to be determined.

Adolescent↗
PubMed1990

Specific A/G-to-C.G mismatch repair in Salmonella typhimurium LT2 requires the mutB gene product.

An assay has been developed that permits analysis of repair of A/G mismatches to C.G base pairs in cell extracts of Salmonella typhimurium LT2. This A/G mismatch repair is independent of ATP, dam methylation, and mutS gene function. The gene product of mutB has been shown to be involved in the dam-independent pathway through the in vitro assay. Moreover, specific DNA-protein complexes and an endonuclease can be detected in S. typhimurium extracts by using DNA fragments containing an A/G mismatch. These activities are not observed with substrates which have a T/G mismatch or no mismatch. The S. typhimurium endonuclease, like the A/G endonuclease found in Escherichia coli (A-L. Lu and D.-Y. Chang, Cell 54:805-812, 1988), makes incisions at the first phosphodiester bond 3' to and the the second phosphodiester bond 5' to the dA of the A/G mismatch. No incision site was detected on the other DNA strand. Extracts prepared from mutB mutants cannot form A/G mismatch-specific DNA-protein complexes and do not contain the A/G endonuclease activity. Thus the A/G mismatch specific binding and nicking activities are probably involved in the A/G mismatch repair pathway. Preliminary analysis of the mutational spectrum of the mutB strain has indicated that this mutator allele causes an increase in C.G-to-A.T transversions without affecting the frequencies of other transversion or transition events. In addition, the mutB gene has been mapped to the 64-min region of the S. typhimurium chromosome. Together, this biochemical and genetic evidence suggests that the mutB gene product of S. typhimurium is the homolog of the E. coli micA (and/or mutY) gene product.

Adenine↗
PubMed1989

High incidence of pulmonary tuberculosis in the non-HIV infected immunocompromised patients in Hong Kong.

In areas where tuberculosis is endemic, clinicians managing immunocompromised patients (ICP) are confronted with the possibility of Mycobacterium tuberculosis as a pathogen. To determine the incidence and clinical pattern of, the diagnostic approach to, and potential therapeutic implications of pulmonary tuberculosis in this patient population, we reviewed 62 non-HIV infected ICP in Hong Kong who had bronchoscopy because of pulmonary infiltrates. Pulmonary tuberculosis was the second most common cause after bacterial infections. Clinical and radiographic presentations of 12 patients with tuberculosis were nonspecific. Flexible bronchoscopy for tuberculosis carried a diagnostic sensitivity of 91.7 percent. We conclude that for the non-HIV infected ICP from areas where tuberculosis is endemic: M tuberculosis should be suspected as the pathogen; radiographic findings are diagnostically not helpful; FB is a sensitive diagnostic test for tuberculosis and in smear-negative cases where tuberculosis is suspected, initiation of empiric anti-tuberculosis therapy should be considered while awaiting culture results.

Adult↗
PubMed1989

Possible evidence for a variant of myasthenia gravis based on HLA and acetylcholine receptor antibody in Chinese patients.

A comprehensive study of 194 Chinese patients with myasthenia gravis in Hong Kong has shown distinct differences from the patterns of disease seen in Caucasians. Restricted ocular myasthenia is the predominant disease type in patients presenting in the first two decades of life and is associated with absence or low titres of acetylcholine receptor antibody. Predisposition to this type of disease is strongly associated with HLA-DRw9. Generalized myasthenia gravis occurs predominantly in patients presenting after the age of 20 years and is accompanied by high titres of acetylcholine receptor antibody but is less strongly associated with HLA-DRw9. It is suggested that myasthenia gravis occurring within the first two decades of life and characterized by affected ocular muscles and absence or low titre of acetylcholine receptor antibody is a genetically determined variant of the disease which occurs commonly in Orientals.

Adult↗
PubMed1986

HLA antigens and acetylcholine receptor antibody in the subclassification of myasthenia gravis in Hong Kong Chinese.

Thirty seven Chinese adults and 23 children in Hong Kong with myasthenia gravis were tested for HLA-A and -B antigens and acetylcholine receptor (AChR) antibody. HLA BW46 had a significantly increased prevalence in patients with juvenile onset ocular myasthenia gravis. Only one third of the juvenile ocular patients had AChR antibodies and the titres were generally low. In the adult patients taken as a whole there was a non-significant increase in the prevalence of HLA B5 and HLA B15. HLA BW46 was more prevalent in adult patients without AChR antibody and less prevalent in patients with AChR antibody but the findings were not statistically significant. It is suggested that ocular myasthenia gravis is determined by a pathological mechanism for which susceptibility is determined by HLA BW46. There was a strong correlation between ocular myasthenia gravis and Graves' disease in the adult patients. The possibility that ocular myasthenia gravis is accentuated by a BW46-associated predisposition to ocular Graves' disease is considered.

Adolescent↗
PubMed1986

Thymectomy in myasthenia gravis during pregnancy.

A 24 year old woman with myasthenia gravis suffered an antepartum exacerbation which failed to respond to increasing dosages of pyridostigmine. Thymectomy performed in the second trimester was followed by clinical improvement and full term vaginal delivery with no puerperal deterioration.

Adult↗
PubMed1986

Endobronchial tuberculosis revisited.

Analysis was made of 20 patients with endobronchial tuberculosis proven by fiberoptic bronchoscopy and bronchial biopsy. Unlike prechemotherapy reports, the disease affects the older age group and more men. Only one half of the patients had fever, and the characteristic localized wheeze was found in 15 percent of cases. Chest roentgenogram showed typical collapse-consolidation in most cases; however, it was clear in 20 percent of patients. Sputum/smear was negative for AFB in 85 percent of patients. When the gelatinous granulation tissue was not found during bronchoscopy, a diagnosis of bronchogenic carcinoma was made incorrectly in 30 percent of patients. At a mean period of 27 months postchemotherapy, all 12 patients recalled for study developed bronchostenosis proven by bronchoscopy/bronchography except one. Noninvasive methods such as chest roentgenogram and flow-volume loops were insensitive for detection of stenosis. Steroid therapy probably did not influence outcome of tuberculous endobronchitis.

Adolescent↗
PubMed1985

Respiratory problems in myasthenia gravis.

We evaluated our experience involving 27 patients with myasthenia gravis with particular reference to the various respiratory problems encountered. These included restriction of ventilation, respiratory tract infections, aspiration due to bulbar weakness, respiratory failure requiring mechanical ventilation, and post-thymectomy pulmonary complications.

Acute Disease↗
PubMedDate not supplied

Coagulation and cytokine profile after major hepatobiliary surgery in Chinese patients.

BACKGROUND/AIMS: Hypercoagulability and increased circulating cytokine levels have been separately reported after surgical operations. We investigated whether the cytokine level and postoperative coagulation profile would change similarly in Chinese patients undergoing major hepatobiliary surgery. METHODOLOGY: Serial serum levels of IL-6, IL-1 beta and TNF-alpha were measured by colorimetric ELISA. Serial coagulation profile was measured by thrombelastography. Hemoglobin and white cell counts were also measured serially. RESULTS: Only mild hypercoagulability was found at the 12th and 144th hours, evidenced by shortening of r-time and k-time on thrombelastography (P < 0.05). IL-6 and IL-1 beta levels were significantly raised from the 12th hour (P < 0.01) while TNF-alpha level was unchanged. From the 3rd hour to the 48th hour, there was negative correlation between IL-6 levels and various thrombelastographic parameters such as coagulation index (r = -0.777, P < 0.001); k-time (r = 0.478, P < 0.05); maximum amplitude (r = -0.688, P < 0.01) and angle (r = -0.665, P < 0.01). CONCLUSIONS: We observed a much milder degree of hypercoagulability in Chinese patients after major hepatobiliary surgery as compared to those reported in other operations in non-Chinese patients. Unlike in sepsis where a close link between increased cytokine levels and hypercoagulability has been reported, increase in IL-6 was associated with less hypercoagulability in Chinese patients after major hepatobiliary surgery.

Adult↗