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Biomedical subjects

D Brown

Publications and source records attributed to D Brown.

1,193 records · Page 67Linked to original sources
PubMedDate not supplied

The disposition and cerebrospinal fluid penetration of morphine and its two major glucuronidated metabolites in adults undergoing lumbar myelogram.

STUDY OBJECTIVE: To determine the pharmacokinetic disposition of morphine and its two major glucuronidated metabolites, morphine-6-glucuronide (M6G) and morphine-3-glucuronide (M3G), in serum and their penetration into cerebrospinal fluid (CSF). DESIGN: A single-dose, open-label pharmacokinetic study. SETTING: The Memphis Neurosciences Center at Methodist Hospital. PATIENTS: Twenty patients undergoing a diagnostic lumbar myelogram. INTERVENTIONS: All patients received morphine sulfate 10 mg intramuscularly approximately 1.5 hours before the procedure. MEASUREMENTS AND MAIN RESULTS: Three blood samples were drawn after the dose and a CSF sample was drawn immediately after lumbar puncture. The mean +/- standard deviation for the half-life of morphine was 2.8 +/- 1.4 hours. The apparent half-lives of M6G and M3G were 5.7 +/- 3.1 and 6.3 +/- 2.2 hours, respectively, and were inversely related to the estimated creatinine clearance (r = -0.61, p < 0.007 and r = -0.69, p < 0.002, respectively). The mean concentrations of morphine, M6G, and M3G in the CSF (collection time 1.5 +/- 0.32 hrs, n = 19) were 3.1 +/- 3.7, 12.5 +/- 17.6, and 19.6 +/- 16.1 nmol/L, respectively. CONCLUSIONS: Elderly patients and patients with renal dysfunction receiving morphine may experience prolonged analgesic and adverse effects secondary to a decrease in the clearance of M6G.

Adult↗
PubMedDate not supplied

The status of indirect restorative dental materials.

The ideal restorative material should enable restoration of teeth that have either suffered trauma or have been prepared during the removal of caries to their original function and appearance. At the same time a seal should develop between the material and the tooth to prevent bacteria-laden fluids from permeating the dentine and reaching the pulp. Few, if any, of the available materials fulfil these requirements. This, the second of a short series, considers the status of indirect restorative materials as the millennium approaches. In this review indirect restorative materials are regarded as those which call not only upon the dexterity and judgement of the dental practitioner, but also upon the skills of the dental technician and techniques of construction that are suitable for use only in a laboratory. Included in this group are the dental casting and bonding alloys, dental ceramics and those resin composites that are shaped, cured and finished in the laboratory.

Composite Resins↗
PubMedDate not supplied

Ophthalmoplegic migraine: reversible enhancement and thickening of the cisternal segment of the oculomotor nerve on contrast-enhanced MR images.

BACKGROUND AND PURPOSE: Ophthalmoplegic migraine is a rare condition characterized by the association of headaches and an oculomotor nerve palsy. We report six patients with typical clinical features of this disorder in whom enhancement of the cisternal segment of the oculomotor nerve developed during the acute phase, followed by resolution of enhancement over several weeks as the symptoms resolved. METHODS: Six patients, ages 3 to 27 years, underwent MR imaging during the acute phase of ophthalmoplegic migraine and at the time of recovery several weeks later. The MR studies, performed on a 1.5-T MR unit, included noncontrast and contrast-enhanced axial and coronal T1-weighted sequences. Sagittal images were obtained in two patients, with and without contrast enhancement. RESULTS: Enhancement of the cisternal segment of the oculomotor nerve was seen in all patients at initial presentation. Contrast-enhanced studies also showed focal thickening at the exit of the nerve in the interpeduncular cistern in five of six patients. No patient had enhancement of the cavernous sinus or adjacent dura. Enhancement was almost completely resolved on follow-up studies 7 to 9 weeks later. CONCLUSION: Our findings confirm an intrinsic transient abnormality in the cisternal segment of the third nerve in patients with a typical clinical presentation of ophthalmoplegic migraine.

Adolescent↗