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1.  Botulinum toxin for cerebral palsy; where are we now? 
Archives of Disease in Childhood  2004;89(12):1133-1137.
PMCID: PMC1719754  PMID: 15557051
2.  Human ventilatory response to washed and unwashed cottons from different growing areas. 
Thirty volunteer subjects were exposed to controlled amounts of respirable dust generated by the carding of cotton in an experimental cardroom. Eighteen exposures each lasting six hours were performed while carding unwashed and washed cottons from the three major growing regions of the United States. Elutriated dust was analysed gravimetrically and was comparable (0.59 mg/m3 +/- 0.04) for all exposures. Spirometry was recorded before and after each exposure. California cotton resulted in a significantly smaller fall in FEV1 than cotton of the same grade from Texas or Mississippi. All washed cottons resulted in reduced declines when compared with unwashed cottons. For 17 subjects breathing zone personal total dust samples were analysed for airborne endotoxin and compared with the individual's pulmonary function response. A significant correlation between endotoxin exposure and acute decrease in FEV1 was seen. The effect on FEV1 per nanogram of airborne endotoxin was greater for Mississippi cotton than for cotton from the other regions. Airborne endotoxin appears to be an important determinant of acute pulmonary effects of cotton dust. Water washing of cotton results in reduced airborne endotoxin and less bronchoconstriction.
PMCID: PMC1007630  PMID: 3947581
3.  Acute lung function response to cotton dust in atopic and non-atopic individuals. 
Acute spirometric responses to inhaled cotton dust were examined in a population of 226 healthy, non-asthmatic adults whose atopic status had been evaluated by skin prick tests to 10 common environmental allergens. Exposure to cotton dust occurred in model cardrooms where elutriated dust levels were carefully controlled (1.02 mg/m3). Atopy, defined as positive prick tests to at least two allergens, was observed in 26% of subjects. Significant forced expiratory volume in one second (FEV1) decrements occurred after exposure to cotton dust independent of atopic status (p less than 0.001). The mean FEV1 decline in atopic subjects, however, was significantly greater than in non-atopic subjects (p less than 0.05). Degree of atopy, as measured by number of positive skin tests, also exhibited a significant association with cotton induced decrements in FEV1 (p less than 0.05). These data suggest that atopy may be an important determinant of the magnitude of the acute pulmonary response to cotton dust. This may reflect the non-specific airways hyperresponsiveness that has been described in non-asthmatic, atopic individuals.
PMCID: PMC1009374  PMID: 6498112
4.  Cotton induced bronchoconstriction detected by a forced random noise oscillator. 
Lung function responses to inhaled cotton dust were evaluated in a group of 58 healthy subjects by spirometry (MEFV curves) and forced random noise impedance parameters. Twenty-one of these subjects were also examined by body plethysmography to assess changes in airway resistance (Raw). For the study group as a whole, alterations in lung mechanical function after exposure to cotton dust were detected by maximal expiratory volumes and flows (p less than 0.001) and impedance parameters (p less than 0.01) but not by Raw. Subjects showing responses in MEFV curves also showed increases in Thevenin or effective resistance at low frequencies (R1, R5-9, R5-9/R20-24), suggesting that the limitation of flow occurred predominantly in the peripheral airways. By contrast, non-responders on MEFV measurements were found to have significant increases in effective resistance both at low and at high frequencies (R1, R5-9, R20-24), suggesting a central airways effect. MEFV curve non-responders also exhibited a significantly lower baseline effective resistance profile than MEFV curve responders. The data indicate that under the conditions of the experiment measures of the Thevenin resistance (real part of impedence) by the forced random noise method are reliable indicators of cotton induced bronchoconstriction. Measurement variability, however, suggests that, at present, these are more appropriate for group studies and should remain adjuncts to standard tests of lung function such as spirometry.
PMCID: PMC1009373  PMID: 6498111
6.  Scope of surgery for intracranial aneurysm in the elderly: a preliminary report. 
British Medical Journal  1978;2(6132):246-247.
Thirty-two elderly patients were reviewed six months to six years after intracranial surgery for subarachnoid haemorrhage. Out of 24 patients whose surgical outcome had been satisfactory, one had died from an unrelated illness and the remainder were well and leading normal lives. Eight patients had a poor outcome, which in some cases was due to factors other than age. In only three could a poor outcome be attributed to early surgery and advanced age. The results confirm that in at least three-quarters of patients aged 60-65 the risk of further haemorrhage can be removed by surgery without causing a major neurological deficit.
PMCID: PMC1606364  PMID: 678887
7.  Carotid-ophthalmic aneurysms. 
Thirty-two cases of carotid-ophthalmic aneurysms are reviewed. As with intracranial aneurysms in other positions they present mainly with subarachnoid haemorrhage but, in spite of their close proximity to the optic nerve, visual involvement is infrequent. They are more common in women, more frequent on the left side, and more prone to multiplicity. In cases of multiple aneurysms a carotid-ophthalmic aneurysm is usually an incidental finding. Detailed angiographic studies employing various projections are required before treatment can be planned. Yet angiography does not always disclose some of the technical difficulties that may be encountered during surgery. Different methods of treating these aneurysms are discussed and suggestions for safe direct surgery made.
PMCID: PMC492471  PMID: 993805
8.  Pilot study of closing volume in byssinosis. 
A study of the relative sensitivities of forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMF), and closing volume (CV) in the detection of subjects with byssinosis was carried out in a North Carolina cotton mill. Altogether 35 workers participated in the study. Of these, nine showed a decline in FEV1 of 10% or more during the first work shift that followed the weekend break. Twelve subjects showed a decrease in MMF of 15% or more. In contrast only six workers exhibited a 10% increase in closing capacity, while ten showed a 10% increase in CV. Recent evidence of the magnitude of variability in closing volume manoeuvres suggests that our chosen level of change was too low, A 40% change in CV would have identified only five subjects. CV is a more complex manoeuvre for the subject being tested and for the technician to perform, is more time consuming, and is subject to greater variation. To have any advantage over spirometry, CV would have to be appreciably more sensitive. Our study suggests that it is not. However, the MMF may prove to be more sensitive than the FEV1 in the detection of byssinosis.
PMCID: PMC1008065  PMID: 1156572
9.  Variability in the size of airspaces in normal human lungs as estimated by aerosols. 
Thorax  1975;30(3):293-299.
Measurement of persistence, expressed as half-life (t1/2), of a monodisperse aerosol during breath holding was interpreted as an indirect estimate of the size of intrapulmonary airspaces in healthy subjects. Within subject variation of t1/2 measured over a period of nearly two years was small (coefficient of variation 7-7 to 11-5%). Mean effective airspace diameters were calculated from the aerosol t1/2 values using the settling term from the equation of Landahl (1950). Calculated mean airspace diameters ranged from 0-30 to 0-79 mm for 36 males and from 0-40 to 0-62 mm for 12 females. Airspace diameters correlated poorly with age, height, weight, and lung volumes. These results suggest marked differences in airways geometry in subjects with similar heights and lung volumes.
PMCID: PMC470281  PMID: 1145534
11.  Surgery of the dyskinesias. 
PMCID: PMC1645413  PMID: 4281485
15.  Age- and size-related reference ranges: A case study of spirometry through childhood and adulthood 
Statistics in Medicine  2009;28(5):880-898.
Age-related reference ranges are useful for assessing growth in children. The LMS method is a popular technique for constructing growth charts that model the age-changing distribution of the measurement in terms of the median, coefficient of variation and skewness. Here the methodology is extended to references that depend on body size as well as age, by exploiting the flexibility of the generalised additive models for location, scale and shape (GAMLSS) technique. GAMLSS offers general linear predictors for each moment parameter and a choice of error distributions, which can handle kurtosis as well as skewness. A key question with such references is the nature of the age-size adjustment, additive or multiplicative, which is explored by comparing the identity link and log link for the median predictor.
There are several measurements whose reference ranges depend on both body size and age. As an example, models are developed here for the first four moments of the lung function variables forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC in terms of height and age, in a data set of 3598 children and adults aged 4 to 80 years. The results show a strong multiplicative association between spirometry, height and age, with a large and nonlinear age effect across the age range. Variability also depends nonlinearly on age and to a lesser extent on height. FEV1 and FVC are close to normally distributed, while FEV1/FVC is appreciably skew to the left. GAMLSS is a powerful technique for the construction of such references, which should be useful in clinical medicine. Copyright © 2008 John Wiley & Sons, Ltd.
PMCID: PMC2798072  PMID: 19065626
age-related reference ranges; GAMLSS; LMS method; skewness; spirometry; height; weight; allometry

Results 1-15 (15)