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Biomedical subjects

A B Murray

Publications and source records attributed to A B Murray.

At least 73 records · Page 4Linked to original sources
PubMed1981

Airway responsiveness to histamine as a test for overall severity of asthma in children.

Seventy-eight children who had a history of asthma were studied while they were symptom-free. There was a highly significant correlation between the dose of aerosolized histamine that produced a decrease in FEV1 of 20% and each of the features in the history that indicated severity of asthma. The correlation was strengthened by the combination of these features into a weighted asthma history score. None of the subjects with mildly increased bronchial reactivity had a history score of severe asthma, and none with markedly increased bronchial reactivity had mild asthma. There was also a highly significant correlation between histamine dose and the results of spirometric tests for airway obstruction. However, the correlation between asthma history score and provocative histamine dose was highly significant even in the 21 subjects who were apparently free of airway obstruction at the time of testing. Furthermore, the correlation between asthma history score and histamine dose was stronger than that between asthma score and any spirometric test, indicating that the histamine test more accurately assessed the overall severity of the asthma. Measurement of bronchial responsiveness to histamine is a useful adjunct to history in determining the severity of asthma in an individual and should be considered as an objective way of grading subjects according to severity of asthma in a clinical study.

Adolescent↗
PubMed1981

A comparison of spirometric measurements in allergen bronchial challenge testing.

We compared the usefulness of several spirometric measurements in detecting asthmatic reactions after allergen bronchial challenge in fourteen asthmatic children. All of the children had a history suggesting mite-induced asthma and eleven had a 3 mm or larger diameter weal on prick testing with Dermatophagoides farinae extract. On bronchial challenge testing with dilutions of this extract twelve children had an early asthmatic reaction and nine had a late asthmatic reaction. In decreasing order of sensitivity for detecting the early asthmatic reaction the tests ranked as follows: FEV1, FEF50%, FEF25-75%, PEFR and FVC. For the late asthmatic reaction the order was FEF50%, FEV1, FEF25-75%, PEFR and FVC. No single test identified all the early or all the late reactions but the FEV1, a test useful for indicating large airways obstruction, when combined with the FEF25-75%, a test influenced by small airways obstruction, detected all early and late asthmatic reactions. The FEF50% was a sensitive test but was the only one to become falsely positive. It became falsely positive in four patients. Although the FEV1 was the most useful single test the results suggest that it is, by itself, an inadequate indicator of the asthmatic reaction and that it should be used with the FEF25-75% to ensure the detection of all asthmatic reactions induced by allergen bronchial challenge testing.

Adolescent↗
PubMed1981

Ultrastructural changes in rat hepatocytes after partial hepatectomy, and comparison with biochemical results.

Ultrastructural changes in rat hepatocytes in the first 24 h following partial hepatectomy (p.h.), i.e. in the premitotic phase of liver regeneration, were studied using electron microscopic morphometry. Livers were investigated 1/2, 1, 4, 8, 12, 20 and 24 h after p.h. and 1/2, 8, 20 and 24 h after a sham operation. Two effects appear to be associated specifically with the regeneration process: (1) an increase in the volume density of lysosomes to a peak between 4 and 8 h after p.h.; and (2) a doubling in the number of mitochondria per cell by 24 h without any associated increase in the total mitochondrial volume. Two further changes were observed only after p.h.: (1) a massive accumulation of lipid in the form of lipid droplets by 24 h; and (2) the appearance of 'protein droplets' (very large lysosomal-like structures) at various stages. Both these changes appear to be secondary effects associated with the stimulation for, but not necessary to, cell division. The loss of glycogen observed immediately after both p.h. and a sham operation is a non-specific effect probably resulting from operation-induced stress. The results are discussed with reference to the changes observed in the biochemical composition of blood plasma. Glucagon appears to play an important role in the stimulation of some of the ultrastructural changes observed.

Animals↗
PubMed1980

Molluscum contagiosum and herpes simplex in Maasai pastoralists; refeeding activation of virus infection following famine?

An epidemic of molluscum contagiosum and oro-genital herpes simplex was observed in Maasai pastoralists of the Rift Valley. It coincided with a period of refeeding following famine, when the relief diet was different from normal milk fare. We propose that refeeding may be an important mechanism for activation of certain viral infections previously suppressed by famine.

Adolescent↗
PubMed1980

An ecological interdependence of diet and disease? A study of infection in one tribe consuming two different diets.

The nature and incidence of infections were studied in two groups of Turkana living in the same area but eating different diets; one consumed milk only and the other a combination of fish and milk. The only apparent and significant nutritional difference between the two groups was mild iron deficiency in the milk drinkers. Episodes of fever, symptomatic infection with malaria and brucellosis, molluscum contagiosum and common warts, episodes of diarrhea, and serological evidence of infection with Entamoeba histolytica were significantly increased in Turkana eating fish. We suggest that this phenomenon may result from a disruption of a long-standing ecological compromise between the all-milk diet of the Turkana and the pathogenic organisms.

Adolescent↗
PubMed1980

Changes in hepatocyte volume and liver weight in rats in the early phase after partial hepatectomy.

The weight of the liver remaining at various times after 2/3 partial hepatectomy (p.h.) was determined as a percentage of its weight at the time of operation, calculated from the known weight and percentage of liver removed. The percentage change in liver weight was shown to correlate closely to the percentage change in average "mononuclear" hepatocyte cell volume as determined by light microscope morphometry. Average hepatocyte volume remains within 10% of the initial value for the first 14 h after p.h. therefore increasing to 130% of initial volume at 24 h after p.h. Average hepatocyte volume in sham operated animals is reduced to 68% of initial volume by 0.5 h after operation, returning to normal by 24 h after operation. A similar decrease was observed in the average hepatocyte volume of animals starved for 19 h.

Animals↗
PubMed1979

The seasonal variation in a population of house dust mites in a North American city.

Mattress dust collected at monthly intervals for 2 1/2 yr was examined for mites. Both Dermatophagoides pteronyssinus and D. farinae were found. There was a significant association between the presence of live mites and the relative humidity (RH): Live mites were seen only when the RH had been greater than or equal to 50% for at least part of every day during the month of collection. There was a seasonal variation in that live mites were found only in the warmer months and not in the winter. However, the peak in the mite population was consistent neither for month nor for numbers: In 1977 a slight peak in mite numbers occurred in October, while in 1978 the peak was higher and occurred in July. Use of data from previously published studies to preduct mite levels may therefore be misleading.

Animals↗
PubMed1979

Anorexia of infection as a mechanism of host defense.

The role of anorexia of infection as a mechanism of host defense was studied by force-feeding infected mice to a normal energy intake. Their mortality and survival times were then compared with those of infected mice feeding ad libitum. Mortality was increased and survival time shortened in force fed animals. Our observations suggest that anorexia, by reducing energy intake, has a significant role in the early defense of the host.

Animals↗
PubMed1979

Three-dimensional reconstruction of the chromatin bodies in the nuclei of mature erythrocytes from the newt Triturus cristatus: the number of nuclear envelope-attachment sites.

The arrangement of the chromatin bodies in the interphase nuclei of 6 erythrocytes has been investigated by means of 3-dimensional reconstruction from electron micrographs of serial sections. When the borders of chromatin bodies are marked on the surface of each model, discrete areas of chromatin in contact with the nuclear envelope are revealed. The number of these areas in approximately equal to the number of chromosomes in the diploid set. The data suggest that each chromatin body corresponds to a condensed interphase chromosome and that each chromosome is attached to one discrete site on the nuclear envelope. The data are insufficient to show whether or not the condensed chromosomes are arranged in any orderly pattern in these nuclei.

Animals↗
PubMed1978

The adverse effect of iron repletion on the course of certain infections.

The incidence of infections was studied in 137 iron-deficient Somali nomads, 67 of whom were treated with placebo and 71 with iron. Seven episodes of infection occurred in the placebo group and 36 in the group treated with iron; these 36 episodes included activation of pre-existing malaria, brucellosis, and tuberculosis. This difference suggested that host defence against these infections was better during iron deficiency than during iron repletion. Iron deficiency among Somali nomads may be part of an ecological compromise, permitting optimum co-survival of host and infecting agent.

Adolescent↗
PubMed1978

Serum cholesterol, triglycerides and heart disease of nomadic and sedentary tribesmen consuming isoenergetic diets of high and low fat content.

1. The effects were examined of two approximately isoenergetic diets differing widely in saturated fat content on the levels of serum cholesterol and triglycerides of nomads and non-nomads in eastern Niger. Each person was also examined for clinical and electrocardiographic evidence of heart disease. 2. No significant differences could be found between serum cholesterol and triglyceride levels of 297 Anagamba nomad men consuming 73% energy as fat and 303 Kanouri sedentary men consuming 9% energy as fat. 3. Rheumatic heart disease was common in nomads and four possible cases of ischaemic heart disease were found in sedentary men only.

Adolescent↗