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Biomedical subjects

C MacArthur

Publications and source records attributed to C MacArthur.

51 records · Page 3Linked to original sources
PubMed1990

A modified bronchoalveolar lavage procedure that allows measurement of lung epithelial lining fluid volume.

We replaced the standard serial bronchoalveolar lavage technique with a new "rewash" lavage procedure to allow estimation of the volume and protein concentration of the epithelial lining fluid (ELF) in anesthetized sheep. A bronchoscope 6.0 mm in diameter wedged in an airway was used to lavage a segment of lung with four cycles of instillation and aspiration of the lavage solution containing a radioactive tracer (technetium pertechnetate, 99mTcO4-). Errors caused by the fall in concentration of the tracer during the lavage were minimized by extrapolating the tracer concentration back to time zero when the lavage solution had mixed with the ELF, but had not had time to be affected by loss of the tracer or influx of fluid from the interstitium. In control sheep, the ELF of these lavaged segments had a mean volume of 1.6 +/- 1.0 ml and a mean protein concentration that was 26 +/- 19% of the protein concentration measured in the plasma. Increasing the left atrial pressure 19 +/- 5 cm H2O to cause "cardiac lung edema" had no significant effect on the ELF volume, but it increased the mean protein concentration to 57 +/- 30% of the plasma value (p less than 0.01). Lung injury caused by intravenous oleic acid caused lung edema, increased the mean ELF volume to 6.8 +/- 2.2 ml, and increased the mean ELF protein concentration to 86 +/- 26% of the plasma value (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Smoking in pregnancy: effects of stopping at different stages.

Of 4341 pregnant women, 3106 were non-smokers and 1235 were smokers at the start of pregnancy. Eighty-five had stopped smoking before 6 weeks gestation, 119 between 6 and 16 weeks, and 56 stopped after 16 weeks. A further 51 stopped temporarily and 924 smoked throughout pregnancy. The mean birthweight of the groups differed. There were also social and biological differences such as might partly explain birthweight variations so comparisons were repeated after allowing for these factors. Standardized mean birthweights were greater for all groups who stopped than for persistent smokers. Those who stopped before 6 weeks and between 6 and 16 weeks gestation had infants 217 and 213 g, respectively, heavier than the persistent smokers and similar to the non-smokers. Babies born to those who stopped after 16 weeks, or temporarily, were intermediate in weight. Appropriate advice is that stopping any time before 16 weeks is best, but stopping after this is still beneficial.

Adult↗
PubMed1988

A peptide from alveolar macrophages that releases neutrophil enzymes into the lungs in patients with the adult respiratory distress syndrome.

A monoclonal antibody has been made to a peptide that is released by human alveolar macrophages. This enzyme-releasing peptide (ERP) causes neutrophils to secrete azurophilic granule enzymes. Normal subjects, patients with pulmonary fibrosis, and patients with sarcoidosis had similar concentrations of this peptide in their bronchoalveolar lavage fluids. However, patients with the adult respiratory distress syndrome (ARDS) had about 2.7 times higher concentrations in their lavage fluids. The enzyme-releasing activity in the lavage fluids was significantly correlated with 2 indices of the severity of the clinical illness in patients with ARDS, the APACHE score, and the chest radiograph score. The correlation was diminished or ablated by removing the peptide with the monoclonal antibody bound to staphylococcal Sepharose 4B. This peptide accounted for 62.08% (SD = 15.88%) of the enzyme-releasing activity in fluids from lungs of patients with ARDS and 86.39% (SD = 24.46%) of the activity in fluids from lungs of normal control subjects. Therefore, ERP is the major neutrophil enzyme-releasing agent in the bronchoalveolar lavage fluid from patients with ARDS and from normal persons. There was a significant correlation between the neutrophil enzyme-releasing activity and the ERP concentrations in BAL of patients with ARDS. These observations suggest that modulation of neutrophil function by ERP significantly controls the protease and peroxidase loads in the lungs of patients with ARDS.

Adolescent↗
PubMed1987

Effect of anti-smoking health education on infant size at birth: a randomized controlled trial.

The effects of anti-smoking health education during pregnancy on smoking behaviour and the subsequent infant's size at birth were investigated in a controlled trial. It was found that the planned educational intervention was incompletely carried out and was given more effectively to primigravidae in whom subsequent reduction of smoking was more evident. The effects of educative intervention on size at birth were therefore analysed for first and later pregnancies separately. The differences in birthweight and length between the intervention and control groups were concentrated almost entirely among the first born infants who were 68 g heavier and 0.75 cm longer in the intervention group than the first born infants in the control group.

Anthropometry↗
PubMed1985

Treatment delay in patients with bladder tumours.

Previous work has shown that the hospitals are the most important source of delay in treatment of bladder cancer rather than the patient or the general practitioner. We have studied referral of patients for investigation and treatment in the North West Region using data from the cancer registry. Delay in treatment for this disease is appreciably longer than for the other common cancers we have studied. Various factors associated with speed of treatment are discussed.

Adult↗
PubMed1984

Factors associated with speed of diagnosis, referral, and treatment in colorectal cancer.

Delay in the presentation of symptoms and in referral of patients for surgical opinion remains an important problem in colorectal cancer. Factors influencing patients to consult early include advice from close family or other associates and abdominal pain or vomiting, or both, as one of the early symptoms. More localised rectal symptoms and loss of weight are often associated with long delay. The "classic" symptom pictures are not often seen in the early stages of the disease. Few identifiable factors were associated with delay in referral for surgical opinion. Doctors who examine their patients (rectally or otherwise) refer them sooner. In the districts studied delay in instituting definitive treatment after consultant referral does not seem to be a major problem. There is some evidence that delay is associated with stage of the disease at presentation.

Colonic Neoplasms↗
PubMed1983

Delay in the diagnosis of colorectal cancer.

Investigation of factors affecting the speed of diagnosis, referral and treatment of 113 patients with colorectal cancer shows that failure to examine the patient was significantly associated with delay. Patients who were not given a rectal or abdominal examination at their first medical consultation experienced considerably more delay in being referred for specialist opinion. Factors affecting the decision to examine are described.

Colonic Neoplasms↗
PubMed1977

Health norms in pregnancy.

A study was conducted on a sample of pregnant women. The study had two aims: to develop a method of measuring social expectations (norms) and to find out how far women conform in their behaviour to these norms. The areas of behaviour were smoking, exercise, diet, alcohol, and medication. Pregnancy was found to be appropriate for this study because of the high degree of formalisation that this state enjoys in our society. The methods used for measuring norms in this study are an improvement on earlier methods, but further refinements are needed. The findings show that women generally do conform to the social expectations and that their behaviour is in accordance with three types of norms--that is, general, specific, and transitional. The implications for health education interventions are discussed.

Alcohol Drinking↗
PubMed1975

Collision behavior of young drivers. Impact of the change in the age of majority.

A comparison of the number of collisions experienced by young male drivers in London, Ontario, before and after the reduction in the legal age for drinking and purchasing alcoholic beverages from 21 to 18, indicated that the change in the law led to an increase in the collision involvement of young drivers.

Accidents, Traffic↗
PubMed1975

Hematologic responses to prolonged extracorporeal circulation (ECC) with microporous membrane devices.

Twenty-four to 48 hr veno-arterial bypass with microporous membrane oxygenators causes moderate progressive thrombocytopenia associated with decreased platelet function, no significant change in clotting factors, fibrinogen, or the fibrinolytic system, and minimal change in white blood count, differential, and plasma hemoglobin. These effects are identical to those seen in previous studies following the same protocol with solid silicone rubber membrane oxygenators. Microporous membrane is suitable for prolonged extracorporeal support systems. This study suggests that the deleterious effects of a direct blood gas interface are caused by continuous renewal of the surface rather than the nature of the interface itself.

Adenosine Diphosphate↗