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Biomedical subjects

S McKenzie

Publications and source records attributed to S McKenzie.

At least 73 records · Page 4Linked to original sources

Unsuspected bronchospasm in association with topical timolol--a common problem in elderly people: can we easily identify those affected and do cardioselective agents lead to improvement?

The extent of impairment of respiratory function in a group of 52 elderly, glaucomatous patients receiving topical timolol therapy was investigated. To predict those patients who were likely to benefit from changing therapy, symptoms were elicited by direct questioning, and lung spirometry was measured before and after inhalation of salbutamol. Changing from timolol to either pilocarpine or the cardioselective betaxolol produced improvement in lung function tests. Mean peak flow increased from 278 l/min to 328 l/min (p < 0.001), forced expiratory volume in 1s (FEV1) from 1.66 l to 1.85 l (p < 0.001) and forced vital capacity (FVC) from 2.41 to 2.64 l (p < 0.001). Spirometry in a control group of 20 subjects was unchanged. Nineteen of 47 patients demonstrated a clinically significant (defined as 15% or more) increase in all values of lung function tests. Change to pilocarpine or betaxolol was equally effective in producing improvement but betaxolol had fewer side-effects. The presence of exertional dyspnoea, cough with sputum, raised dyspnoea score and improved lung function tests after salbutamol identified those patients experiencing clinically significant bronchospasm with an 89% specificity and 74% sensitivity.

Aged↗

Molecular diagnosis of the Philadelphia chromosome translocation. A comparison of isotopic and chemiluminescent Southern blotting.

Southern blotting using radiolabeled probes is a well established technique for the detection of the Philadelphia translocation in the diagnosis of chronic myelogenous leukemia (CML). However, the use of radioisotopes in the clinical setting is often problematic. Because of this we investigated the use of a digoxigenin-labeled probe and chemiluminography in the detection of the Philadelphia translocation. In this study DNA was extracted from 19 bone marrow or blood samples from patients with CML or other malignancies and subjected to Southern blotting with a probe specific for the Philadelphia translocation, Phl/bcr3. The probe was labeled with either 32P or digoxigenin to determine the relative sensitivity and specificity of autoradiography and chemiluminography in the molecular diagnosis of the BCR/abl fusion gene. All 19 samples were tested by both methods. All blots were performed and interpreted by individuals blind to the initial patient diagnosis. In addition, 12 samples (6 positive for CML, 6 negative for CML as determined by Southern blotting with 32P-labeled probe) were subjected to triplicate Southern-blot analyses, with three separate lots of digoxigenin-labeled probe to assay batch to batch variability in the efficacy of the probe. Radiolabeled and digoxigenin-labeled probes resulted in identical diagnoses in all cases. All results obtained by molecular analysis correlated perfectly with the clinical diagnoses of the patients from whom the samples had been obtained. Reanalysis of patient samples with different batches of digoxigenin-labeled probe gave highly reproducible results. With digoxigenin-labeled probe, diagnostic results were obtained after exposure times of less than 1 h at room temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗

Chemical and glass thermometers for axillary temperatures: how do they compare?

Axillary temperatures recorded with a disposable chemical thermometer (DCT) measured a mean 0.29 degrees C higher than a mercury in glass thermometer (MGT) but differences could be wide. Differences between the same methods were however also wide. The DCT is safe and easy to use. Provided the higher readings are taken into consideration it is a suitable alternative to the MGT.

Adolescent↗

Improved lung function tests on changing from topical timolol: non-selective beta-blockade impairs lung function tests in elderly patients.

Fifty-two elderly glaucomatous patients, without a history of asthma or obstructive airways disease, who were using topical timolol for control of intraocular pressure were recruited. Their topical therapy was changed to either betaxolol or pilocarpine. The change was associated with improvement in mean peak flow from 278 l/min to 328 l/min (t = 5.73, p < 0.001), mean FEV1 from 1.66 l to 1.85 l (t = 7.09, p < 0.001) and mean FVC from 2.40 l to 2.64 l (t = 5.07, p < 0.001). Change to either betaxolol or pilocarpine was associated with improved lung function tests. Lung function tests in a control group of 20 showed no significant changes. Both drugs maintained control of intraocular pressure but betaxolol had fewer ocular side effects.

Administration, Topical↗

Streptococcal vulvovaginitis in girls.

Group A beta-hemolytic Streptococcus (GAHS) was isolated from 18% of swabs submitted to a district microbiology laboratory from girls with vulvovaginitis, a figure similar to that from a contemporary British study. This suggests that vulvovaginitis is more commonly associated with GAHS than reported previously. This could represent either an increase in frequency of the condition or better recognition of it.

Adolescent↗

Blastomycosis in patients with the acquired immunodeficiency syndrome.

OBJECTIVE: To describe the clinical, demographic, radiographic, diagnostic, and therapeutic aspects of blastomycosis in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: A retrospective survey. SETTING: Ten university medical centers and community hospitals, six in geographic areas endemic for Blastomyces dermatitidis, and four outside the endemic area. PATIENTS: We identified 15 patients with blastomycosis and positive serologic test results for human immunodeficiency virus (HIV). MEASUREMENTS: A diagnosis of blastomycosis was based on a positive culture (14 patients) or typical histopathologic features (one patient) for B. dermatitidis in clinical specimens. RESULTS: Twelve of 15 patients had a previous or concomitant AIDS-defining illness at the time of diagnosis of blastomycosis, and only one patient had a CD4 lymphocyte count of greater than 200 cells/mm3. Two patterns of disease emerged: localized pulmonary involvement (seven patients), and disseminated or extrapulmonary blastomycosis (eight patients). Central nervous system involvement was common (40%). Six patients died within 21 days of presentation with blastomycosis, including four patients with disseminated and two with fulminant pulmonary disease. Among the nine patients who survived longer than 1 month, all received amphotericin B as initial antifungal therapy, and most received subsequent therapy with ketoconazole. Only two of these nine patients died with evidence of progressive blastomycosis. CONCLUSIONS: Blastomycosis is a late and frequently fatal infectious complication in a few patients with AIDS. In these patients, overwhelming disseminated disease including involvement of the central nervous system is common, and it is associated with a high early mortality. Initial therapy with amphotericin B is appropriate in patients with AIDS and presumptive blastomycosis.

Acquired Immunodeficiency Syndrome↗

Phorbol ester-induced hairy cell features on chronic lymphocytic leukemia cells in vitro.

Leukemic cells from eight patients with chronic lymphocytic leukemia were isolated and cultured in the continuous presence of 12-O-tetradecanoylphorbol 13-acetate (TPA) at a concentration of 1.6 x 10(-9) M for 4-10 days. Aliquots of cells were then analyzed at intervals of 24-72 hr for changes in morphology, acid phosphatase staining (AP), and expression of two hairy cell-associated surface antigens, HCL1 (CD22, Leu 14) and HCL3 (CD11c, Leu M5). All cases studied showed typical B-CLL phenotype, and only a small proportion of cells expressed CD22 and CD11c (mean 7% and 4.9%, respectively). TPA treatment induced the coexpression of CD22 (mean 49%) and CD11c (mean 48%) and tartrate-resistant acid phosphatase in seven of eight cases. Morphologically, cells in TPA cultures expressed hairy cell features that were evident in light and electron microscopic studies. Collectively these changes indicate that TPA can induce hairy cell features on CLL cells in vitro, suggesting the later maturational stage of HCL compared with CLL.

Acid Phosphatase↗

Requirements for the internalization of a murine monoclonal antibody directed against the HER-2/neu gene product c-erbB-2.

A murine monoclonal antibody, TA1, is directed against an epitope on the extracellular domain of the HER-2/neu (c-erbB-2) gene product. Requirements for TA1-induced internalization of c-erbB-2 have been studied using the SKBr3 human breast cancer cell line and several rat fibroblast cell lines that express either wild-type or mutant human c-erbB-2. Internalization of TA1 was monitored by assaying protease-resistant uptake of 125I-labeled TA1, by electron microscopy of gold-labeled TA1, and by inhibition of clonogenic growth of cells incubated with TA1 that had been conjugated with blocked ricin. Similar rates of internalization of TA1 were observed in SKBr3 and in rat fibroblasts that expressed human c-erbB-2. The route of endocytosis was the same as that observed with antibodies against other membrane receptors. Anti-c-erbB-2 and anti-transferrin receptor cointernalized through clathrin-coated pits, coated vesicles, endosomes, and multivesicular bodies. Products of mutant c-erbB-2 that lacked a portion of the tyrosine kinase domain or that lacked most of the cytoplasmic domain were endocytosed in the presence of TA1 as promptly as the wild-type c-erbB-2 product. Slightly more rapid internalization of TA1 was observed in rat cells that expressed c-erbB-2 with a single point mutation in the transmembrane domain. Taken together, our data suggest that neither the intracytoplasmic domain nor receptor phosphorylation is required for antibody-mediated endocytosis of c-erbB-2.

Animals↗

Results of a randomized trial comparing idarubicin and cytosine arabinoside with daunorubicin and cytosine arabinoside in adult patients with newly diagnosed acute myelogenous leukemia.

4'-Demethoxydaunorubicin (idarubicin [IDR]) is a new anthracycline that differs from its parent compound by the deletion of a methoxy group at position 4 of the chromophore ring. This minor structural modification results in a more lipophilic compound with a unique metabolite that has a prolonged plasma half-life as well as in vitro and in vivo antileukemia activity. To determine its activity in acute myelogenous leukemia (AML), 130 consecutive adult patients between the ages of 16 and 60 with newly diagnosed disease were randomized in a single institution study to receive either IDR in combination with cytosine arabinoside (Ara-C) or standard therapy with daunorubicin (DNR) and Ara-C. The trial was analyzed using the O'Brien-Fleming multiple testing design that allowed for periodic inspection of the data at specific patient accession points. After accrual of 60 patients per arm, analysis showed that patients who received IDR/Ara-C had a superior response compared with those who received standard therapy: 48 of 60 patients (80%) achieved complete remission on the former arm compared with 35 of 60 patients on the latter (58%, P = .005). Logistic regression analysis of factors associated with complete response indicated that treatment with IDR/Ara-C offered a significant advantage to patients who presented with a high initial white blood cell count compared with treatment with DNR/Ara-C. The degree of marrow aplasia was approximately the same on each arm as was nonhematologic toxicity. Overall survival for patients on the IDR/Ara-C arm was 19.5 months compared with 13.5 months on the DNR/Ara-C arm (P = .025) at a median follow-up of 2.5 years. We conclude that IDR/Ara-C can effectively replace standard therapy with DNR/Ara-C in adult patients less than age 60 with newly diagnosed AML.

Adult↗

Case report: fatal pulmonary toxoplasmosis following chemotherapy.

A 41-year-old woman with acute myelomonocytic leukemia in remission died of a rapidly progressive necrotizing pneumonia while in the recovery phase following consolidation chemotherapy. Autopsy revealed disseminated toxoplasmosis. Although this syndrome has been well described to present as a neurologic complication in certain immunocompromised patients, it is rare in acute leukemia, and non-neurologic presentations are even more unusual. This case emphasizes the need to be suspicious of toxoplasmosis in immunocompromised patients even in the absence of neurologic signs or symptoms.

Adult↗

Troublesome crying in infants: effect of advice to reduce stimulation.

The observation that babies with troublesome crying improve quickly in hospital suggested that, if true, a common, quickly reversible, factor may operate. Histories from parents of such babies suggest that much work goes into trying to console them. It is hypothesised that this may lead to excessive stimulation and the improvement seen in hospital reflects a reduction in stimulation. Two studies were undertaken. (1) Carers were asked to agree to randomisation of their infants to hospital or home management. Those at home were advised to reduce stimulation. A 10 point questionnaire was used to describe distress in mothers of subjects and age matched controls. (2) A randomised controlled study compared advice to reduce stimulation with an empathic interview using a +5 to -5 scale to chart change. In the first study too few subjects agreed to randomisation and thus a rigorous study to validate the observation could not proceed. There was good evidence, however, that crying improved. Results from the home group justified the second study. The median distress score for subjects was 7/10 and for controls 3/10 (p less than 0.001). In the second study at seven days, 18/22 subjects given advice scored +2 or better on the change chart for crying, compared with 7/20 of those who did not receive advice (p less than 0.01). After the latter received advice 79% improved (95% confidence interval 61 to 97%). For babies under 12 weeks, the customary upper limit for a diagnosis of colic, 14/15 subjects advised improved compared with 6/12 who were not advised (p less than 0.02). These studies have shown that infants with troublesome crying admitted to hospital seem to improve quickly as do those whose carers are advised to reduce stimulation.

Crying↗