PubMed Health⌕ Search

Biomedical subjects

D McLellan

Publications and source records attributed to D McLellan.

At least 19 recordsLinked to original sources
PubMed2004

Inferior turbinate reduction in children using Holmium YAG laser-a clinical and histological study.

BACKGROUND AND OBJECTIVES: To compare the efficacy and safety of inferior turbinate reduction in children using Holmium:YAG (Ho:Yag) laser and diathermy. Histological effects of these treatments on turbinate tissue are also studied. STUDY DESIGN/MATERIALS AND METHODS: A retrospective review and structured telephone interview of paediatric cases treated with Ho:Yag laser and diathermy to inferior turbinates. The complications, morbidity and efficacy were quantified. Histological sections of inferior turbinates treated with diathermy (surface and submucosal) and laser were compared. RESULTS: Efficacy in the laser (n = 8) and diathermy group (n = 11) was similar. The complication/morbidity score was lower in the laser group, 1.92 versus 3.48, (P = 0.04, CI: 0.01, 2). Long-term benefit was 50 and 36% in the laser and diathermy group respectively. Histology showed very limited tissue damage in all methods of treatment. CONCLUSIONS: Ho:Yag laser treatment is equally efficacious, but causes less complications and morbidity compared to surface diathermy. Both treatment methods have poor long-term efficacy, which may be related to limited tissue damage.

Adolescent↗
PubMed2004

Use and limitations of imatinib mesylate (Glivec), a selective inhibitor of the tyrosine kinase Abl transcript in the treatment of chronic myeloid leukaemia.

Chronic myeloid leukaemia is associated with a specific translocation between chromosomes 9 and 22 that results in the formation of a chimaeric gene. This gene, when transcribed, produces the BCR-Abl oncoprotein which has tyrosine kinase activity and the ability to prevent apoptosis, but has no effect on cellular proliferation. Imatinib mesylate, an inhibitor of the BCR-Abl transcript modelled on the ATP binding pocket of the Abl oncoprotein, prevents phosphorylation of effector molecules and induces apoptosis. Imatinib has limited effectiveness when BCR-Abl cells are in the quiescent cell-cycle state of G0. A life-long regimen of imatinib should reduce the risk of relapse from cells leaving G0. Up-regulation of BCR-Abl expression, ATP binding pocket mutations, up-regulation of MDR1 and over-expression of Pgp are all thought to limit the effectiveness of imatinib. Advanced BCR-Abl positivity is associated with complex mutations, which are thought to have a cumulative effect on the BCR-Abl oncoprotein in disrupting normal signal transduction, making these cells refractory to monotherapy alone. Combination therapy is thought to overcome this. Research studies have identified imatinib as a potential treatment option for a diverse range of malignancies associated with BCR-Abl, platelet-derived growth factor receptor (PDGFr) and c-Kit pathways. This may extend the application of this special therapy in the future.

Antineoplastic Agents↗
PubMed2004

Assessing and intervening on OSH programmes: effectiveness evaluation of the Wellworks-2 intervention in 15 manufacturing worksites.

AIMS: (1) To develop a transparent and broadly applicable method for assessing occupational safety and health (OSH) programmes or management systems; (2) to assess OSH programmes in a sample of manufacturing worksites; and (3) to determine whether a management focused occupational health intervention results in greater improvement in OSH programmes compared to minimal intervention controls. METHODS: OSH programmes were assessed using an adaptation of the US Occupational Safety & Health Administration's 1995 Program Evaluation Profile. Scores were generated from 91 binary indicator variables grouped under four "Essential Elements". Essential Element scores were weighted to contribute to an overall programme score on a 100 point scale. Seventeen large manufacturing worksites were assessed at baseline; 15 sites completed the 16 month intervention and follow up assessments. RESULTS: There was considerable variation in Essential Element scores across sites at baseline as judged by our instrument, particularly in "management commitment and employee participation" and "workplace analysis". Most sites scored highly on "hazard prevention and control" and "training and education". For overall OSH programme scores, most sites scored in the 60-80% range at baseline, with four sites scoring below 60%, suggesting weak programmes. Intervention sites showed greater improvements than controls in the four programme elements and in overall programme scores, with significantly greater improvements in "management commitment and employee participation". CONCLUSIONS: The OSH programme assessment method used is broadly applicable to manufacturing work settings, and baseline profiles suggest needs for improvement in OSH programmes in most such worksites. Despite a small sample size, results showed that sustained management focused intervention can result in improvement in these OSH programme measures.

Community Participation↗
PubMed2001

Organized labor, public health, and tobacco control policy: a dialogue toward action.

An action-oriented conference, Organized Labor, Public Health, and Tobacco Control Policy, was held in September 2000 in Boston, Massachusetts. Labor union leaders, tobacco control and public health activists, researchers, and practitioners met for two days to: 1) learn about existing labor-based tobacco control initiatives; 2) educate one another about resources, barriers, and opportunities for labor-public health joint action on tobacco policy; 3) and identify where agendas overlap and form the basis for specific next steps in collaborative efforts in tobacco-related research, training, and advocacy. This report summarizes presentations and participant discussions to inform readers of the information exchanged and of the enthusiasm shared by conference participants translated into a set of joint recommendations for increased labor-based and joint labor-public health action to reduce the burden of tobacco on working people.

Journal Article↗
PubMed2000

Human immune response to streptococcal inhibitor of complement, a serotype M1 group A Streptococcus extracellular protein involved in epidemics.

Streptococcal inhibitor of complement (Sic) is a highly polymorphic extracellular protein made by serotype M1 group A Streptococcus strains that contributes to bacterial persistence in the mammalian upper respiratory tract. New variants of the Sic protein arise very rapidly by positive selection in human populations during M1 epidemics. The human antibody response to Sic was analyzed. Of 636 persons living in diverse localities, 43% had anti-Sic serum antibodies, but only 16.4% had anti-M1 protein serum antibody. Anti-Sic antibody was also present in nasal wash specimens in high frequency. Linear B cell epitope mapping showed that serum antibodies recognized epitopes located in structurally variable regions of Sic and the amino terminal hypervariable region of the M1 protein. Phage display analyses confirmed that the polymorphic regions of Sic are primary targets of host antibodies. These results support the hypothesis that selection of Sic variants occurs on mucosal surfaces by a mechanism that involves acquired host antibody.

Adolescent↗
PubMed2000

Pediatric genitourinary tumors.

Advances in our knowledge of pediatric genitourinary tumors are being made at both the basic science and clinical levels. The molecular mechanisms underlying these pediatric malignancies are being uncovered and will aid in uncovering novel treatments. Because of the high success rate in treating these tumors, treatment options are being modified to decrease both short- and long-term morbidity, while maintaining the improved survival.

Adolescent↗
PubMed1997

Improving transfusion practices in a busy teaching hospital.

A retrospective audit of blood transfusions was carried out in Cardiff Royal Infirmary (CRI) to investigate how efficiently blood was requested and used by the various clinical directorates. Excessive crossmatch/transfusion (C/T) ratios were found for a number of operations. In an attempt to improve practices, a pilot study was carried out between the Department of Haematology and the largest single requesting group, the Orthopaedic Directorate. As a result of a preliminary retrospective audit, crossmatch guidelines were revised, with more reliance on the group and antibody screen (G & S) for low-risk operations. A subsequent prospective audit showed major reductions in crossmatch requests and a general decrease in C/T ratios to very efficient levels without any patient morbidity. Blood was freed for urgent use elsewhere, and significant cost improvements resulted. This study, using the orthopaedic surgery department as a model, shows the value of inter-departmental audit and supports the experience of other centres using similar methods to make considerable savings in the amount of blood crossmatched unnecessarily.

Blood Banks↗
PubMed1995

Spurious rise in total carbon dioxide and chloride with negative anion gap after cystogram.

We report a case of spurious hyperchloraemia, elevated total carbon dioxide and negative anion gap 9 days following a voiding cystourethrogram (VCU) in a patient with bladder exstrophy and obstructive uropathy. We believe that the spurious laboratory results were due to analytical interference of the absorbed iodine with the method of bicarbonate and chloride measurement. The absorbed iodine was retained in the circulation for an extended period because of associated renal impairment. Our patient was also on piperacillin which might have interfered with iodine clearance. Physicians and laboratory pathologists should be aware of this effect when interpreting laboratory results of patients who have undergone a VCU in association with obstructive uropathy and impaired renal function.

Acid-Base Equilibrium↗
PubMed1990

Hodgkin's disease at the optic chiasm.

In a case of visual loss due to infiltration of the optic chiasm by Hodgkin's lymphoma in a 44-year-old man the diagnosis was supported by histology of the optic chiasm, an axillary lymph node, and bone marrow at presentation. This appears to be only the third histologically proven reported case of Hodgkin's disease in this location, and the first diagnosed during life.

Adult↗
PubMed1987

Haemoglobinopathy screening in a 'low-risk' area of the United Kingdom: South Glamorgan, Wales.

Figures collected over 2 1/2 years of screening of women attending the antenatal clinics of South Glamorgan, Wales, showed that the percentage of women identified as a risk for haemoglobinopathy trait (7.4%) was almost twice that estimated from the 1981 Census data (4.1%) and that the incidence of a thalassaemia trait in these women (0.38% beta; 0.68% alpha) was similar to that of an area of supposedly greater risk in London (0.46% beta; 0.42% alpha). Figures from one laboratory showed that without a scrutiny of all antenatal clinic blood counts for thalassaemic indices some thalassaemia traits will be missed. The apparent incidence of the HbS trait was 0.13%, and reasons for this being an underestimate are given.

Female↗
PubMed1986

Perspectives on occult bacteremia in children.

Bacteremia in young children seen in the outpatient clinic is a reasonably frequent occurrence with occasionally serious sequelae; most patients, however, do quite well. The problem is more perplexing in infants and young children with high fever and no apparent focus of infection. Laboratory tests and clinical observations help to determine which children are at low risk of occult bacteremia and need not have blood cultured; testing and assessment are much less predictive of the child who does have occult bacteremia. Currently, it is unclear whether treating all patients at risk is warranted. In any case, very close follow-up of the patient who is sent home from the outpatient department with high fever is desirable. The prevalence of serious infections caused by pneumococcus, Hib, and meningococcus warrants continued research on the development of vaccines that effectively prevent these infections.

Anti-Bacterial Agents↗
PubMed1984

Subselective preoperative embolization for meningiomas. A radiological and pathological assessment.

Over a 2-year period the authors have studied the effects of preoperative subselective embolization of meningiomas. Thirty-six consecutive patients shown by computerized tomography (CT) to have a meningioma underwent selective internal and external carotid artery angiography, and any significant external carotid artery feeders were embolized (27 cases). It was found that CT and dynamic radioisotope scan findings were unable to predict the degree of vascularity of the tumor or its suitability for embolization. Furthermore, these tests, repeated after embolization, were unreliable in detecting either the extent of necrosis or reduction in blood flow. The effects of embolization upon surgery were recorded, and the excised tumor specimen examined for evidence of thrombosis and infarction. Subselective embolization was determined to be a simple, safe, and effective method of producing tumor necrosis and intraoperative hemostasis in selected patients.

Adult↗