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Biomedical subjects

L Dow

Publications and source records attributed to L Dow.

30 records · Page 2Linked to original sources
PubMed1992

Respiratory symptoms as predictors of airways lability in an elderly population.

In an attempt to identify patterns of symptoms which might predict treatable airways obstruction in the elderly, we measured respiratory function and airways lability in 296 men and women aged 65 and over. Subjects were selected to represent eight symptom groups as ascertained in a postal survey of patients randomly selected from three general practice lists. Airways obstruction was strongly associated with smoking, but bronchial hyperresponsiveness to methacholine and reversibility of airways obstruction with salbutamol (measured when hyperresponsiveness could not be assessed) were not. There was evidence of bronchial hyperresponsiveness or salbutamol reversibility in 37% of symptomatic non-smokers. This points to a substantial component of obstructive lung disease in the elderly that is characterized by labile airways and unrelated to smoking. Symptoms of the 'bronchial irritability syndrome' were more strongly associated with airways lability than other symptoms, but their predictive value for airways lability (32%) was much lower than has been reported in younger adults.

Aged↗
PubMed1992

The interaction between immunoglobulin E and smoking in airflow obstruction in the elderly.

Airflow obstruction and serum immunoglobulin E (IgE) were assessed in 250 men and women 65 to 91 yr of age who had been selected from a larger general population sample according to reported respiratory symptoms. After allowance for age and sex, serum IgE and smoking interacted synergistically as risk factors for airflow obstruction such that on average an IgE > or = 81 IU/ml in current smokers was associated with a FEV1/FVC ratio 14.4 percentage points (95% CI, 8.8 to 19.9) less than in lifelong nonsmokers with an IgE < or = 10 IU/ml. This synergistic interaction was apparent in subjects who showed no evidence of airway lability (i.e., no hyperresponsiveness to inhaled methacholine or, if bronchial hyperresponsiveness could not be tested, no clear improvement in airflow obstruction after inhalation of salbutamol). The findings suggest that the role of IgE in the pathogenesis of airflow obstruction is not confined to asthmatics.

Age Factors↗
PubMed1991

Expression of embryonic globins by erythroid cells in juvenile chronic myelocytic leukemia.

Juvenile chronic myelocytic leukemia (JCML) is a rare hematopoietic neoplasia of early childhood with distinct hematologic and biochemical features. We studied the biologic properties and the globin synthetic profiles of JCML erythroid cells both in vivo and in vitro from a total of 24 patients. In these cases we observed the exuberant colony-forming unit-macrophage (CFU-M) colony growth, as reported previously. Furthermore, in contrast to previous reports, we found significant erythroid colony growth in most of our cases (average: 1,182 burst-forming unit-erythroid [BFUe] per 10(5) plated cells, range: 40 to 6,927). This growth was by and large erythropoietin-dependent and was not greatly influenced by other added cytokines. By several criteria all erythroid colony growth detected in vitro was derived from JCML progenitors. The globin synthetic profile of JCML erythroid cells showed high levels of fetal hemoglobin both in vivo and in vitro (gamma/gamma + beta: 53% to 94% in reticulocytes, 62% to 98% in BFUe-derived cells). In addition (in seven cases studied) we detected embryonic globins (epsilon and zeta) at the protein and messenger RNA level, a novel finding for primary leukemic cells. We speculate that the transformed erythroid cells in JCML harbor a trans environment supporting expression of developmentally earlier genes (fetal, embryonic). However, in contrast to other acute or subacute leukemias, JCML erythroid cells also have the ability to reach full maturation to the red cell level, thus allowing detection of this primitive program in vivo.

Bone Marrow↗
PubMed1991

A population survey of respiratory symptoms in the elderly.

Reversible airways obstruction is not uncommon in the elderly, but may be overlooked because of the high prevalence of other disorders with a similar presentation. In a search for patterns of symptoms which might predict treatable airways obstruction, we carried out a survey of men and women aged 65 yrs and over. Postal questionnaires were completed by 2,161 subjects selected at random from the lists of three general practices. Almost 60% of the sample complained of one or more respiratory symptoms. Smoking was a more important risk factor than age, sex or social class, and was associated particularly with wheeze, morning phlegm and chest tightness on waking. Several groups of symptoms tended to cluster in the same individuals. The two most closely related were chest tightness and breathlessness in response to animals, dust and feathers. Responses to irritants tended to cluster according to the symptom produced (cough, breathlessness or wheeze) rather than the provoking stimulus (smoke, cold air, household chemicals or traffic fumes). There was no evidence for the existence of the "bronchial irritability syndrome" which has been linked with asthma in younger adults. The relationship of symptoms to respiratory function and bronchial reactivity will be reported in a further publication.

Age Factors↗
PubMed1982

Blood creatine kinase isoenzyme BB in boxers.

Creatine kinase isoenzyme BB (CK-BB) is found in high concentrations in the brain. Normally concentrations in blood are undetectable or low. Blood concentrations of CK-BB were measured in 16 boxers before and after a fight and in 16 track cyclists before and after a race. Blood CK-BB rose to significantly higher concentrations in the boxers than in the cyclists. The number of blows received to the head was estimated in half the boxers and correlated significantly with the rise in CK-BB. This increase in blood CK-BB may indicate disruption of the blood-brain barrier. This may be one of the mechanisms accounting for brain damage in boxers.

Adolescent↗
PubMed1982

Pharmacokinetics of Teniposide (VM26) and etoposide (VP16-213) in children with cancer.

The clinical pharmacokinetics of VM26 and VP16-213 were assessed in 15 children (median age 10 years) with acute leukemia, using a new high-performance liquid chromatography-electrochemical assay. Pharmacokinetic parameters were calculated by both model-dependent and compartment model-independent methods. These studies demonstrated substantial differences in the central volumes of distribution (VDc), steady-state volumes of distribution (VDss) and systemic clearances (Cls) of VM26 and VP16-213; with the VDc, VDss, and Cls all being smaller for VM26, Systemic clearances determined by model-independent methods were 5.2 +/- 1.0 ml/min/m2 (mean +/- SD) for VM26 and 17.8 +/- 11.2 ml/min/m2 for VP16-213. The major metabolites. detected in serum and urine were the hydroxy acids. Low levels of the picro-lactone isomers were detected in some patients while the aglycones were not detected in the serum or urine of any patients.

Biotransformation↗
PubMedDate not supplied

Is grasping impaired in hemispatial neglect?

Patients with right unilateral cerebral stroke, four of which showed acute hemispatial neglect, and healthy aged-matched controls were tested for their ability to grasp objects located in either right or left space at near or far distances. Reaches were performed either in free vision or without visual feedback from the hand or target object. It was found that the patient group showed normal grasp kinematics with respect to maximum grip aperture, grip orientation, and the time taken to reach the maximum grip aperture. Analysis of hand path curvature showed that control subjects produced straighter right hand reaches when vision was available compared to when it was not. The right hemisphere lesioned patients, however, showed similar levels of curvature in each of these conditions. No behavioural differences, though, could be found between right hemisphere lesioned patients with or without hemispatial neglect on either grasp parameters, path deviation or temporal kinematics.

Aged↗
PubMedDate not supplied

The epidemiology and therapy of airflow limitation in the elderly.

Airways disease is a frequent problem poorly recognised in older people. Many have reversible airway limitation and do not receive appropriate therapy. As in younger patients, pulmonary function tests are essential as a baseline and in relation to formal trials of treatment in both the diagnosis and management. Preferably, the assessment of all patients with airflow limitation should include a corticosteroid trial to correctly identify all patients who need long term prophylactic therapy. Many older patients have difficulty using the metered dose inhalers and the addition of volume spacer devices, though cumbersome, has many further advantages. In some patients, airflow limitation may be complicated by the presence of cardiac failure, arrhythmias and arterial hypoxia, and these problems also need to be reviewed.

Age Factors↗