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Biomedical subjects

G R Kelman

Publications and source records attributed to G R Kelman.

At least 19 recordsLinked to original sources
PubMed1986

Effects of human exposure to atmospheric epsilon-caprolactam.

There is little published information on the human toxicology of epsilon-caprolactam, the monomer precursor of nylon 6. This paper reports an investigation of a group of eight workers who had been chronically exposed to atmospheric caprolactam levels of around 70 times the current ACGIH threshold limit value (TLV). No evidence of systemic toxicity was found, although all workers showed a greater or lesser degree of skin change in the form of peeling and/or fissuring.

Adult↗
PubMed1986

Choice reaction time in workers exposed to styrene vapour.

Behavioural effects of occupational exposure to vapour from styrene-based resin were investigated in 10 female workers with a portable test of choice reaction time. Testing was carried out both at the beginning and end of the day's shift. Uptake and metabolism of styrene were assessed by monitoring post-shift urinary mandelic acid excretion rates. By using these data workers were allocated to three groups reflecting zero, low or high exposure. After exposure slowing of reaction times was found in those with the highest mandelic acid excretion rates, whereas a slight improvement or no change was found in those with low or zero exposure. Subsequent improvements in extraction and ventilation in the workroom were shown to be associated with both decreased mandelic acid excretion and absence of long reaction times in those previously most heavily exposed.

Air Pollutants, Occupational↗
PubMed1986

Cadmium metabolism in man.

The time course of the fall in blood cadmium concentrations after cessation of exposure has been measured in nine workmen exposed to cadmium. When the initial blood cadmium concentration was below 180 nmol/l (six subjects) it declined smoothly and roughly exponentially, with a mean half-life of 20.4 months and a final asymptote of 70 nmol/l; in the remaining three subjects (initial blood cadmium concentration above 180 nmol/l) the decay was less regular and more prolonged (mean half-life 31.4 months, final asymptote 92 nmol/l). The significance of these results in relation to occupational cadmium exposure is discussed.

Adult↗
PubMed1984

Diurnal variations in urinary mercury excretion.

A consistent diurnal variation of urinary mercury concentration (expressed as nmol of mercury/mmol of creatinine) has been demonstrated in 36 occupationally exposed workers, the concentration being highest in the morning and lowest in the late evening. This variation is partly intrinsic and partly an artifact because creatinine excretion also varies diurnally, but in the opposite direction. The implications of these findings in relation to the biological monitoring of mercury workers is discussed.

Circadian Rhythm↗
PubMed1982

Theoretical basis of alveolar sampling.

The conditions under which the partial pressure of a solvent in the alveolar gas is likely to provide a valid index of its partial pressure in the mixed venous blood, and thus of whole-body exposure, is explored on a theoretical basis. Under steady-state conditions, providing the solvent's blood/gas partition coefficient exceeds 10, its mixed venous and alveolar pressures will agree within 10% and become virtually identical during the prolonged expiration necessary to obtain an alveolar sample. With less soluble solvents, however, this is not necessarily so, and when the partition coefficient is less than three alveolar sampling is unlikely to provide a valid index of mixed venous levels. Abnormalities of pulmonary function, particularly ventilation/perfusion imbalance, are unlikely to alter these conclusions significantly.

Gases↗
PubMed1979

Carboxyhaemoglobin levels in workers in Leicestershire garages.

Blood carboxyhaemoglobin (HbCO%) levels were measured in 61 workers in 35 garages in Leicester and Leicestershire. Of 26 workers in large garages in winter, 44% of the non-smokers and 20% of the smokers had increased CO absorption, the highest HbCO% being 26.0 in a non-smoker. Of 35 workers in 24 smaller, randomly chosen garages visited throughout the year (two per month) the corresponding figures were 43% and 14%, the highest HbCO% being 21.0. The possible relevance of these findings to coronary heart disease in garage workers is discussed.

Carbon Monoxide↗
PubMed1977

Arterial blood gases in pre-eclampsia.

Arterial blood gases, physiological dead space and percentage pulmonary venous admixture (physiological shunt) were measured in 31 patients with proteinuric pre-eclampsia. There was no difference in pulmonary function in 22 patients with moderate pre-eclampsia when compared with normal pregnancy, but in 9 patients with severe pre-eclampsia, there was a significant increase in alveolar-to-arterial PO2 difference and physiological shunt, indicating a degree of pulmonary ventilation/perfusion imbalance. There was no accompanying hypoxaemia, suggesting that the impairment was of no clinical importance.

Arteries↗
PubMed1976

Maternal blood-gases, PAo2--Pao2), hysiological shunt and VD/VT in normal pregnancy.

Serial measurements of maternal blood-gases, alveolar-to-arterial oxygen tension difference (PAO2--PaO), calculated pulmonary venous admixture (physiological shunt), deadspace/tidal volume ratio (VD/VT), and respiratory minute volume have been made in a carefully selected group of normal pregnant patients at 12, 24, 32 and 38 weeks of gestation and 5 weeks after delivery. All measurements were made in the semi-recumbent position with a left lateral pelvic tilt. Mean arterial PO2 was consistently greater than 100 mm Hg throughout pregnancy, although the value decreased from 106.4 mm Hg at 12 weeks of gestation to 101.8 mm Hg at the 38th week. Despite this decrease there was no change in (PAO2--PaO2) VD/VT, or percentage shunt with increasing gestation; nor did these values differ significantly from non-pregnant values in the same patients.

Adult↗
PubMed1975

Pulmonary function in asthmatic patients in remission.

Thirty-five asthmatic patients (average age 28 years) who attended a pulmonary function laboratory when their mean ratio of forced expiratory volume in one second: forced vital capacity was 81 per cent (within the normal range for their age group) had arterial hypoxaemia and hypocapnia. These were probably secondary to lung hyperinflation and pulmonary ventilation/perfusion imbalance. The pulmonary abnormalities of bronchial asthma are not always detected by simple spirometric tests and the results of such tests should be interpreted cautiously.

Adult↗