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Biomedical subjects

M O'Doherty

Publications and source records attributed to M O'Doherty.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of positron emission tomography scanning and sentinel node biopsy in the detection of micrometastases of primary cutaneous malignant melanoma.

PURPOSE: Sentinel node biopsy (SNB) is a surgical technique for detecting micrometastatic disease in the regional draining nodes. 2-fluorine-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) scanning is an imaging technique that can detect clinically undetectable metastases. This prospective study was undertaken to compare the sensitivity of FDG-PET scanning with SNB in the detection of micromatastatic malignant melanoma. PATIENTS AND METHODS: Fifty consecutive patients (23 women, 27 men; mean age, 53 years) with primary melanoma >1 mm thick or lymphatic invasion were recruited (mean, 2.41 mm). Primary lesions had been narrowly excised (<1 cm). Patients underwent PET scanning followed by SNB, using a dual technique. Preoperative lymphoscintigraphy was used to identify the draining basin. Lymph nodes were examined histologically and immunostained for S100 and HMB 45. RESULTS: The sentinel node (SN) was identified in all patients. Fourteen patients (28%) had positive SNBs, including eight patients with melanoma <1.5 mm thick. In none of these 14 patients did PET scans identify metastatic disease in the SN or draining basin. In seven patients, the PET scans were positive in other locations, and in four cases, this was suspicious of metastatic disease. However, no patient has developed recurrent melanoma (mean follow-up, 15 months). All patients with positive SNBs underwent therapeutic lymph node dissection. Further lymph node involvement was found in two patients (primary lesions, 1.3 mm and 3.5 mm thick). CONCLUSION: This study demonstrates the limitations of FDG-PET scanning in staging patients with primary melanoma. SNB is the only reliable method for identifying micrometastatic disease in the regional draining node.

Adult↗
PubMed1999

Salus populi - the endeavours of Edward Dillon Mapother (1835-1908).

Edward Dillon Mapother had an impressive career as surgeon, dermatologist, author, professor and President of the Royal College of Surgeons in Ireland and first Medical Officer of health for Dublin in 1864. Considered an authority on eczema, gout and the curative powers of spa waters, Mapother returned to the full-time practice of dermatology, moving to London in 1888. He died at his London home on the 3rd of March 1908.

Dermatology↗
PubMed1998

Cost-saving implant training aids.

This article describes a simple step-by-step procedure that uses inexpensive materials to enable those who wish to learn procedures used in the construction of a screw-type implant overdenture to practice these procedures before they use expensive precious metal components. The use of this procedure will result in considerable savings in training costs and affords a greater opportunity to provide practical experience before making this type of an overdenture for patients. It could also provide for a rapid expansion in the number of trained personnel who could make this form of treatment available to a larger number of patients.

Dental Alloys↗
PubMed1998

Reactor-produced radioisotopes from ORNL for bone pain palliation.

The treatment of painful skeletal metastases is a common clinical problem, and the use of therapeutic radionuclides which localize at metastatic sites has been found to be an effective method for treatment of pain, especially for multiple sites for which the use of external beam irradiation is impractical. There are currently several metastatic-targeted agents radiolabeled with various therapeutic radionuclides which are in various stages of clinical investigation. Since neutron-rich radionuclides are produced in research reactors and often decay by emission of beta- particles, most radionuclides used for bone pain palliation are reactor-produced. Key examples of radionuclides produced by single neutron capture of enriched targets include rhenium-186 and samarium-153. In addition, generator systems are also of interest which provide therapeutic daughter radionuclides from the decay of reactor-produced parent radionuclides. One important example is rhenium-188, available from generators via decay of reactor-produced tungsten-188. Tin-117m is an example of a reactor-produced radionuclide which decays with the emission of low-energy conversion electrons rather than by beta- decay. Each of these agents and/or radionuclides has specific advantages and disadvantages, however, the ideal agent for bone pain palliation has not yet been identified. The goal of this paper is to briefly review the production and use of several reactor-produced radionuclides for bone pain palliation, and to discuss the role of the ORNL High Flux Isotope Reactor (HFIR) for the production of many of these radionuclides.

Bone Neoplasms↗
PubMed1996

Technetium-99m sestamibi parathyroid localization is accurate enough for scan-directed unilateral neck exploration.

A retrospective study was conducted into technetium-99m sestamibi imaging of primary hyperparathyroidism to determine the accuracy of identification and localization of parathyroid pathology. Of 56 patients studied, 48 had full preoperative scan data, operative data and pathological results analysed. Overall scan accuracy was 96 per cent. For single gland pathology (adenoma) imaging had a sensitivity of 97 per cent, a specificity of 100 per cent and a positive predictive value of 100 per cent. For single gland disease the side was correctly identified in 100 per cent of cases and the site in 94 per cent, but the respective values were only 82 and 79 per cent for multiple gland pathology. Technetium-99m sestamibi imaging is highly sensitive and accurate for primary hyperparathyroidism, with sufficient positive predictive value and accuracy in single gland disease to allow scan-directed unilateral neck exploration.

Follow-Up Studies↗
PubMed1994

Effect on patient management of a weekend 'on-call' nuclear medicine service.

The Nuclear Medicine Department at Kent and Canterbury Hospital operates a limited weekend on-call service staffed on a rota basis by a technician, a nurse and a doctor. Following a review of the service over a 2-year period, a prospective study was carried out to analyse the workload of the on-call service from August 1991 to July 1992. The aim was to assess the impact of the service on patient management and examine the cost implications. Sixty-two scans were performed during the year (38 Saturday, 22 Sunday, 2 Bank Holiday) of which 52 were ventilation/perfusion (V/Q) lung scans. The study examined the reports on the scans and the subsequent course of treatment and changes in patient management. For V/Q lung scans, anticoagulation therapy was changed in 13 cases as a result of the scan report. Of the lung scans showing low probability of pulmonary emboli, four patients were discharged on the day of the scan and a further eight within 48 h. The total cost of the on-call service (staff and consumables) was 6020 pounds, i.e. less than 100 pounds per patient and less than 2% of the departmental budget. The low cost and high number of changes in patient management indicate a reasonable cost-benefit ratio.

Cost-Benefit Analysis↗
PubMed1991

Fluconazole for oropharyngeal candidiasis in anti-HIV positive haemophiliacs.

Candidiasis of the oropharynx and oesophagus is one of the most common problems encountered in patients with HIV disease. Fluconazole is a bis-triazole antifungal agent with a long serum half-life. Sixteen anti-HIV positive patients (15 haemophiliacs and one blood transfusion recipient) with a clinical diagnosis of oropharyngeal candidiasis were treated with 50 mg fluconazole daily for 14-28 days and then either 150 mg fluconazole or placebo weekly for 6 months in a prophylactic phase. Clinical cure occurred in all patients, and mycological cure occurred in 13/16 (81%) patients. In the prophylactic phase, there were 2/5 (40%) relapses in the placebo arm compared with 1/8 (12.5%) in the fluconazole arm, but this was not statistically significant by Fisher's one-sided exact test (P = 0.31). It is concluded that fluconazole is an effective treatment of oropharyngeal candidiasis and has potential for prophylactic use.

Adolescent↗
PubMed1990

Pulmonary deposition of nebulised pentamidine isethionate: effect of nebuliser type, dose, and volume of fill.

An estimate of the absolute pulmonary deposition of nebulised pentamidine isethionate was obtained in nine patients with AIDS. Two nebuliser systems were compared, System 22 Mizer (Medic-Aid) and Respirgard II (Marquest), with 50 and 150 mg doses of pentamidine in a 3 ml solution driven by an air flow of 6 l/min with the patient in the sitting position. The 50 mg pentamidine dose was repeated with a 6 ml fill with both devices. The nebuliser cloud was labelled with technetium-99m human serum albumin (Ventocol) and lung deposition was measured with a gamma camera. Of the two nebulisers studied, System 22 Mizer delivered more drug to the lungs as a whole and to each individual lung region, including the peripheral and upper zones. For the 50 mg dose the mean (SEM) total pulmonary deposition with the 3 and the 6 ml fill respectively was 2.63 (0.34) and 3.71 (0.41) mg for the System 22 Mizer and 1.37 (0.26) and 1.45 (0.18) mg for the Respirgard II. For the 150 mg dose the System 22 Mizer delivered 7.16 (1.02) mg and the Respirgard II 4.34 (0.57) mg. Increasing the volume of fill from 3 to 6 ml increased pulmonary deposition with System 22 Mizer, and this was related to an increase in nebuliser output. Neither pulmonary deposition nor nebuliser output was increased by using a 6 ml solution in the Respirgard II. Increasing the volume of fill prolonged the time required for nebulisation with both nebulisers. The System 22 Mizer produced more nonpulmonary (gastric and oropharyngeal) deposition of drug, more frequent local adverse effects (cough, burning in the throat, and a metallic taste), and small reductions in lung function, particularly with the 150 mg pentamidine dose. Thus nebuliser type, volume of fill, and nebuliser dose affect the pulmonary deposition of pentamidine. A 300 mg dose of pentamidine via a Respirgard II is generally recommended as providing effective prophylaxis; our results suggest that similar pulmonary deposition can be produced with System 22 Mizer and 150 mg pentamidine. A clinical trial would be needed to show whether this regimen provides similar prophylactic benefit.

Acquired Immunodeficiency Syndrome↗