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Biomedical subjects

P A Bradley

Publications and source records attributed to P A Bradley.

15 recordsLinked to original sources
PubMed1999

N-Substituted (2,3-dihydro-1,4-benzodioxin-2-yl)methylamine derivatives as D(2) antagonists/5-HT(1A) partial agonists with potential as atypical antipsychotic agents.

A series of N-substituted 1-(2,3-dihydro-1, 4-benzodioxin-2-yl)methylamine derivatives with D(2) antagonist/5-HT(1A) partial agonist activity has been prepared as potential atypical antipsychotic agents. Optimization of in vitro receptor binding activity and in vivo activity in rodent models of psychosis has led to compound 24, which showed good affinities for human D(2), D(3), and 5-HT(1A) receptors but significantly less affinity for human alpha(1) adrenoceptors and rat H(1) and muscarinic receptors. In rodents, 24 showed functional D(2)-like antagonism and 5-HT(1A) partial agonism. After oral dosing, 24 showed good activity in rodent antipsychotic tests and very little potential to cause extrapyramidal side effects (EPS), as measured by its ability to induce catalepsy in rats only at very high doses. In the light of this promising profile of activity, 24 has been selected for clinical investigation as a novel antipsychotic agent with a predicted low propensity to cause EPS.

Animals↗
PubMed1996

Uvulopalatopharyngoplasty may compromise nasal CPAP therapy in sleep apnea syndrome.

Uvulopalatopharyngoplasty (U3P) has been advocated for treatment of snoring and sleep apnea/hypopnea syndrome (SAHS), but often it does not effect a cure, so that other therapy (CPAP) is often required. We hypothesized that patients with U3P will have increased mouth air leak during CPAP because of loss of the soft palatal seal. This may result in decreased tolerance and compliance if CPAP therapy is required after U3P. We have therefore compared CPAP tolerance in 13 awake normal male subjects, 13 male patients with SAHS and 13 male patients treated with U3P, all naive to CPAP and matched for age and body mass index. All normal subjects and patients with SAHS were able to tolerate pressures of at least 20 cm H2O without mouth air leak or appreciable discomfort. In contrast male U3P patients started to leak air via the mouth at a mean CPAP pressure of 6.8 (SD, 2.4) cm H2O and were able to tolerate a mean maximal pressure of only 14.5 (SD, 2.6) cm H2O, which was significantly less than that in the other two groups (p < 0.001). We also examined nasal CPAP compliance (machine run time) in eight patients with SAHS who had previous U3P compared with 16 patients with SAHS without U3P. Both groups were matched for age, body mass index, and apnea/hypopnea index. Patients with U3P had significantly lower compliance (mean, 3.5 h/night) compared with patients without U3P (mean, 5.7 h/night), p = 0.01. We conclude that U3P may compromise nasal CPAP therapy by increasing mouth air leak and reducing the maximal level of pressure that can be tolerated.

Humans↗
PubMed1995

Comparison of polysomnography with ResCare Autoset in the diagnosis of the sleep apnoea/hypopnoea syndrome.

BACKGROUND: Increasing referral numbers make the development of simplified accurate methods of diagnosing the sleep apnoea/hypopnoea syndrome highly desirable. The accuracy of one such system--the ResCare Autoset--has been examined. METHODS: Thirty one consecutive patients assessed by polysomnography had simultaneous monitoring of their respiratory pattern using the Autoset system. The Autoset detects episodes of flattening of the flow/time profile using nasal cannulae. RESULTS: There was a good correlation (r = 0.85) between the number of apnoeas+hypopnoeas/hour in bed recorded using polysomnography and the Autoset system. The median difference in such events was 3.1 (95% confidence interval 8.4 to -1.6)/hour in bed. In two patients the Autoset scored 70 apnoeas+hypopnoeas/hour in bed compared with 34 apnoeas+hypopnoeas with 35 arousals/hour in bed by polysomnography; however, this did not alter the diagnostic category of either patient. Autoset gave a sensitivity of 100%, specificity of 92%, positive predictive value of 92%, and negative predictive value of 100%, which was better than oximetry alone. A sleep study using the Autoset system costs 14 pounds compared with 126 pounds for polysomnography. CONCLUSIONS: The Autoset is clinically useful for diagnosing the sleep apnoea/hypopnoea syndrome.

Costs and Cost Analysis↗
PubMed1976

The respiratory tract immune system in the pig. I. Distribution of immunoglobulin-containing cells in the respiratory tract mucosa.

The number of cells containing immunoglobulins A, G and M in the respiratory tract mucosa of pigs from birth to maturity was assessed using the immunoperoxidase technique. Immunoglobulin-containing cells first appeared at 6-7 days of age and rose rapidly to reach levels at 3-4 weeks similar to those in the adult. IgA-containing cells predominated at all sites in all age groups, although there were significant proportions of cells containing IgM and IgG. Our findings suggest that IgA is transported into secretions via the mixed mucoserous glands of the nasal and tracheobronchial mucosa, and that this route is also operative for colostral IgA absorbed from the gut in the baby pig.

Animals↗
PubMed1976

The respiratory tract immune system in the pig. II. associated lymphoid tissues.

The distribution of immunoglobulins A, G and M were assessed in the bronchial lymph node and palantine tonsil of pigs from birth to maturity, using the immunoperoxidase technique. Immunoglobulin-containing cells appeared earlier in the tonsil than in the lymph node; this probably reflects the exposure of the tonsil to environmental antigens. IgG-containing cells predominated after the first 3 weeks of life, but the IgA:IgG ratio was much higher in the tonsil than in the lymph node. Extracellular, reticular staining was visible in the central region of some follicles in addition to a few immunoglobulin-containing cells that resembled large lymphocytes or blast cells.

Animals↗