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Biomedical subjects

G Berry

Publications and source records attributed to G Berry.

At least 181 records · Page 10Linked to original sources
PubMed1978

Pulmonary function in coal workers with Caplan's syndrome and non-rheumatoid complicated pneumosoniosis.

This retrospective study compares the pulmonary function of 24 coal workers with Caplan's syndrome with that of 36 subjects with non-rheumatoid progressive massive fibrosis (PMF). Allowing for differences in radiographical category, age, years worked underground, and smoking, obstruction to air flow as reflected in the one-second forced expiratory volume, the vital capacity, and the ratio of residual volume to total lung capacity, was significantly less in subjects with Caplan's syndrome. No significant differences in transfer factor were found. These findings may be explained by the different pathological features of the two entities. Selection bias does not appear to be responsible for the differences observed between the groups, but studies designed to eliminate this would be desirable.

Age Factors↗
PubMed1977

The biological effects of magnesium-leached chrysotile asbestos.

Chrysotile asbestos was leached in N hydrochloric acid for varying times to produce a range of magnesium-depleted samples. The protein adsorptive capacity, the haemolytic activity, and the capacity to cause selective release of acid hydrolases from macrophages were measured for the various samples in vitro. The carcinogenicity of the same materials was determined following intrapleural inoculation in rats. The adsorptive capacity for albumin decreased linearly with magnesium removal. The haemolytic activity also declined until about half the magnesium had been removed, after which there was little further change. The selective release of acid hydrolases from macrophages in culture increased up to the point at which half the magnesium had been removed but by 90% depletion had declined rapidly. The carcinogenicity of 50% -depleted chrysotile was similar to that of intact, but at 90% depletion the incidence of mesothelial tumours had fallen considerably. There was no evidence that the leached samples fragmented more than the unleached in vivo.

Adsorption↗
PubMed1976

Effect of age at inoculation of asbestos on occurrence of mesotheliomas in rats.

An experiment in which rats were injected intrapleurally with asbestos, the injection taking place at an age of either 2 or 10 months, is reported. In the former group 19 out of 48 rats developed a mesothelioma compared with 17 out of 90 in the latter group. However, by considering the two groups at equal times after injection, eliminating the effects of natural mortality and also taking into account that not all of the mesotheliomas were the cause of death, it was shown that the incidence rate of mesotheliomas was significantly higher (p less than 0.01) in the rats injected at age 10 months and the relative rate was estimated as about 4, with 95% confidence limits of 1.5 and 12. An alternative explanation that the mesotheliomas occurred in the two groups at similar rates, except that in the group injected at age 10 months they occurred on average 4 months sooner after injection, is discussed. Two other groups were also injected, one at age 17 months and the other at 22 months. In the former group two early mesotheliomas were observed, 10 and 74 days after injection, but the next was not observed until over a year later. No explanation of this finding could be suggested other than the possibility that these two tumours were not associated with the asbestos treatment.

Age Factors↗
PubMed1976

Predictions of mortality from mesothelial tumours in asbestos factory workers.

Using the accumulated data on deaths from mesothelial tumours among cohorts of male and female factory workers at a London asbestos textile factory, the mortality from this cause up to the year 2000 AD has been predicted. The limitations of the methods used are pointed out, but it is estimated that for men the mortality due to mesothelial tumours will be between 7% and 11% of the total mortality and somewhat higher for women. The highest number of deaths from mesothelial tumours will occur during the 1980s, thereafter the numbers will decline because of the decreasing size of the cohort resulting from general mortality.

Asbestos↗
PubMed1975

Animal experiments with talc.

Italian talc has been tested on rats using three routes, intra-pleural inoculation, inhalation and ingestion. Groups exposed to superfine chrysotile asbestos and untreated controls were included for comparison. In all the experiments animals were allowed to live out their lives. The intra-pleural inoculation of talc produced no mesotheliomas in contrast to eighteen produced by the chrysotile asbestos. After ingestion, one leiomyosarcoma occurred with Italian talc and one with chrysotile asbestos. Whether these tumours are a consequence of the feeding is uncertain. The inhalation studies demonstrated that with equal dosage, talc can produce a similar amount of fibrosis as asbestos. However, the chrysotile exposed rats developed lung adenomas, adenomatosis and an adenocarcinoma, whereas the only lung tumour seen in animals exposed to talc was a small adenoma, which may have been an incidental finding.

Animals↗
PubMed1974

The effects of the inhalation of asbestos in rats.

Two experiments in which SPF Wistar rats were exposed by inhalation to dust clouds of the UICC standard reference samples for periods of between one day and 2 years are described. All the samples of asbestos produced asbestosis which continued to progress after removal from exposure but only a little fibrosis was observed in control rats. Lung tumours, ranging in severity from adenomata to squamous carcinomata, were produced by all samples but in the controls there were only a few adenomata and none of the more serious tumours. Of the 20 tumours which metastasized, 16 occurred after exposure to one or other of the 2 chrysotile samples. In addition, a total of 11 mesotheliomata occurred, 4 of which were with crocidolite and 4 with Canadian chrysotile. Two of the mesotheliomata occurred with only one day's exposure to asbestos. There was a positive association between asbestosis and lung tumours.

Adenocarcinoma↗
PubMed1973

Mesotheliomata in rats after inoculation with asbestos and other materials.

Four experiments in which SPF Wistar rats were inoculated intrapleurally with asbestos or other materials are described. Mesotheliomata were observed in a considerable proportion of animals with all the samples of asbestos used and with a sample of brucite. A few were produced with synthetic aluminium silicate fibres and single ones with barium sulphate, glass powder and aluminium oxide. The risk of developing a mesothelioma at a given time after injection was approximately proportional to the dose. Of the UICC standard reference samples, crocidolite was the most carcinogenic and removal of the oils by benzene extraction did not alter the carcinogenicity of these samples. Chemical properties also seem unlikely to be the main factor producing mesotheliomata but the results support the hypothesis that the finer fibres are the more carcinogenic, and this is additional to the known aerodynamic advantage which the finer fibres have in penetrating to the periphery of the lung.

Aluminum↗