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Biomedical subjects

T B Chan

Publications and source records attributed to T B Chan.

26 records · Page 2Linked to original sources
PubMed1986

[Effect of buspirone and diazepam on cGMP level in the rat cerebellum].

Diazepam at a dose of 5 and 10 mg/kg significantly decreases (by 50 and 60%, respectively) cGMP content 30 min following intraperitoneal injection to rats. Buspirone, at a dose of 2.5-25 mg/kg produced a nonsignificant (up to 18%) and at a dose of 50 mg/kg a statistically significant (p less than 0.05) 30% decrease in cerebellum cGMP content. Taking into account the identical anxiolytic effects of diazepam and buspirone, it is suggested that pharmacological effects of buspirone are not linked to the activation of GABA-ergic system.

Animals↗
PubMed1985

Effects of histamine on lung permeability in normal and asthmatic subjects.

The permeability of respiratory mucosa, as measured by clearance of diethylenetriamine penta-acetate (DTPA) labelled with technetium 99m, was similar in seven normal and nine asthmatic subjects. Histamine induced bronchoconstriction was associated with a 50% increase in permeability in both groups of subjects. In normal subjects inhaled salbutamol, given as 1 mg acutely or as 200 micrograms four times daily for two weeks, had no effect on pulmonary permeability. Salbutamol, given before histamine challenge, prevented bronchoconstriction, but did not affect the increase in permeability seen in normal subjects. Low doses of histamine, sufficient to cause bronchoconstriction in the asthmatic subjects, produced little bronchoconstriction in normal subjects but caused increases in lung permeability similar to those seen in asthmatic subjects. These studies suggest that these two effects of inhaled histamine, bronchoconstriction and increased permeability, are independent.

Adult↗
PubMed1985

Pulmonary epithelial permeability in normal individuals and asthmatic patients.

It has been suggested that an increase in lung permeability is the cause for bronchial hyperreactivity in asthma. A method for measuring pulmonary epithelial permeability (PEP) has been developed recently. PEP is estimated by calculating the half-time clearance of inhaled diethylene triamine penta-acetate, labelled with 99m-technetium, with a scintillation counter over the right upper lobe of the lung. Seven normal subjects and 7 patients with stable bronchial asthma had PEP determined. Mean half-time clearance of 99m TC-DTPA in normals and asthmatics were 52.4 minutes and 52.7 minutes respectively. There was no significant difference (p less than 0.5) between these baseline values. Therefore, in patients with stable asthma there is no increase in lung permeability compared with normal subjects.

Aged↗
PubMed1985

Spontaneous pneumothorax in medical practice in a general hospital.

Eighty patients with spontaneous pneumothoraces treated in the University Department of Medicine, Singapore General Hospital from January 1981 to March 1983 were reviewed. There were 75 males and 5 females. Their ages ranged from 15 to 92 years. Dyspnea was the chief representing symptom in 59 patients (74%) followed by chest pain in 47 patients (59%). One patient was admitted with loss of consciousness. Pneumothorax with no discernable associated disease was present in 36 patients (45%) whereas 34 (43%) had chronic obstructive airways disease. Of the remaining 10 patients, active pulmonary tuberculosis was present in 5, bronchogenic carcinoma in 2, bronchial asthma in 2 and bronchopneumonia in 1 percent. Pneumothorax occurred equally on both sides. Single episode of pneumothorax was present in 64 patients (80%). Recurrent pneumothoraces were only present in 16 patients (20%). 57 patients (71%) required chest tube insertion while 14 patients (18%) in addition required either medical or surgical pleurodesis. Death occurred in 6 patients (7.5%) mainly in those with chronic obstructive airways disease. In this study the majority of pneumothoraces occurred in patients with either no underlying pulmonary disease or those with chronic obstructive bronchitis and emphysema. A bimodal age presentation was noted, with the younger patients having no underlying respiratory disorders.

Adolescent↗