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Biomedical subjects

S U Rahman

Publications and source records attributed to S U Rahman.

11 recordsLinked to original sources

The glossopharyngeal nerve as a novel pathway in immune-to-brain communication: relevance to neuroimmune surveillance of the oral cavity.

Glossopharyngeal afferents may be the neural channel by which immune challenge of the posterior oral cavity conveys information to the brain. If this is the case, then bilateral transection of the glossopharyngeal nerves (GLOx) should disrupt this communication. Injection of lipopolysaccharide (LPS) or interleukin (IL)-1beta into the soft palate (ISP) of sham-operated rats induced a dose-related febrile response. GLOx significantly attenuated the febrile response induced by ISP injection of both LPS and IL-1beta. In contrast, GLOx did not affect the febrile response when LPS or IL-1beta were injected intraperitoneally, indicating that the effect of GLOx is not systemic. These results provide experimental evidence for a novel neural pathway for immune-to-brain communication.

Afferent Pathways↗

Pulmonary and cardiac beta-adrenoceptor density in vivo in asthmatic subjects.

To examine whether there is a primary deficit in beta-adrenoceptor density in asthma, pulmonary and cardiac beta-receptor density was determined in vivo with positron emission tomography (PET) in 10 male asthmatic subjects (36 +/- 8 yr of age) and compared with that in 30 age-matched normal male subjects (36 +/- 8 yr of age). Pulmonary beta-receptor density was 10.3 +/- 1.8 pmol/g tissue for the asthmatic group and 10.9 +/- 1.9 for the normal group. Cardiac beta-receptor density was 9.1 +/- 3.3 pmol/g for the asthmatic group and 8.8 +/- 2.3 pmol/g for the normal group. There was no difference in either pulmonary or cardiac beta-receptor density between the two groups. In addition, an inverse relationship was observed between FEV1 % predicted and pulmonary beta-receptor density in asthmatic subjects. In conclusion, beta-receptor numbers are normal in untreated asthmatic subjects.

Adult↗

In vivo quantification of human pulmonary beta-adrenoceptors: effect of beta-agonist therapy.

In human subjects, chronic beta2-agonist dosing reduces mononuclear leukocyte (MNL) beta-adrenoceptor numbers. The aim of this study was to investigate whether this downregulation also occurs in the lung. Seven healthy male subjects were treated for 2 wk with oral (up to 16 mg/d) and inhaled (up to 1.6 mg/d) albuterol (salbutamol in Europe). Pulmonary maximal beta-adrenoceptor binding capacity (Bmax) was determined in vivo using positron emission tomography (PET) and the beta-receptor antagonist ligand, 11C-labeled CGP-12177, before and after the 2-wk chronic dosing. MNL Bmax was also measured, using a radioligand binding assay and 3H-labeled CGP-12177. Bronchodilator responses to the beta2-agonist were determined after each PET scan by measuring the change in specific airway conductance (SGaw) after increasing doses of inhaled albuterol. Pulmonary and MNL Bmax fell by 22% +/- 14% (p < 0.05) and 42% +/- 19% (p < 0.05) respectively. The changes in pulmonary and MNL Bmax were correlated (r = 0.9, p < 0.05). There was also a reduction in the bronchodilator response to inhaled albuterol. In a further six subjects, pulmonary and MNL Bmax did not change during an acute infusion of albuterol (2 to 4 microg/kg/h). The reduction in pulmonary beta-adrenoceptor numbers after chronic albuterol dosing may be predictable from the changes observed in circulating MNL cells.

Administration, Inhalation↗

Hepatic haematoma following blunt injury: non-operative management.

Four patients with multiple injuries including suspected closed hepatic injury are described, all of whom needed resuscitation in the Intensive Care Unit. All 4 had local signs suggesting hepatic injuries, but no evidence of generalized intraperitoneal bleeding. They were carefully monitored clinically, and the suspected diagnosis of hepatic haematoma was confirmed by ultrasound scanning and follow-up with repeated scans until complete resolution occurred. All made a satisfactory recovery and are well and asymptomatic, except for one patient who has residual orthopaedic disabilities.

Adolescent↗

Effect of long-term beta2-agonist dosing on human cardiac beta-adrenoceptor expression in vivo: comparison with changes in lung and mononuclear leukocyte beta-receptors.

BACKGROUND: Tachyphylaxis to the cardiac effects of beta-adrenoceptor stimulation after long-term beta2-agonist administration is well recognized, but the influence on global cardiac beta-adrenoceptor density has not been previously investigated in vivo. Positron emission tomography (PET) has made possible the noninvasive quantification of regional receptor density. This study assesses the effect of long-term beta2-agonist dosing on cardiac beta-adrenoceptors. METHODS AND RESULTS: Beta-adrenoceptors in the hearts of 29 healthy male subjects aged 35 +/- 8 years were imaged and quantified in vivo by means of PET and compared with the receptor density in the same subjects' lung tissue. Mononuclear leukocyte (MNL) beta-receptor density was determined in vitro by means of a radioligand binding assay. Beta-receptor density was 8.41 +/- 2.03 pmol/gm tissue in heart, 10.81 +/- 1.91 pmol/gm tissue in lung, and 38.0 +/- 17.5 fmol/mg protein on MNLs. There was a weak relationship between cardiac and pulmonary beta-receptor densities (r = 0.45, p < 0.02) but not between cardiac and MNL receptor density. In seven subjects, the measurements were repeated after 2 weeks of albuterol treatment (4 mg orally twice daily and 200 microg inhaled four times daily in the first week, with doubling of the dose during the second week). After the albuterol treatment, beta-receptor density fell on average by 19% (p < 0.05) in the heart compared with 22% (p < 0.05) in the lung and 42% (p < 0.05) in MNLs. Correlations were found between the percentage changes in receptor density in heart and lung (r = 0.98, p < 0.001) and in heart and MNLs (r = 0.99, p < 0.002). CONCLUSIONS: Two weeks of high-dose albuterol results in equivalent downregulation of beta-receptors in vivo, both in the lung and in the heart.

Adrenergic beta-2 Receptor Agonists↗