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Biomedical subjects

G A Harrison

Publications and source records attributed to G A Harrison.

At least 199 records · Page 11Linked to original sources
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Isolation and comparison of the IgM heavy chain constant regions from Australian (Trichosurus vulpecula) and American (Monodelphis domestica) marsupials.

cDNAs encoding IgM heavy chain constant region (Cmu) were isolated from two metatherians (marsupials)--the Australian common brushtail possum (Trichosurus vulpecula) and the South American grey short-tailed opossum (Monodelphis domestica). Analysis of the sequences suggested that they correspond to the secreted form of Cmu in both species. The domain size and structure of the marsupial Cmu sequences were compared with other Cmu sequences and a high degree of conservation throughout vertebrate evolution was observed. Amino acid sequence comparisons revealed a marked level of sequence similarity between the two marsupial sequences (79%), relatively high similarity between the marsupials and eutherians (63%), and lower similarities between marsupials and birds (45%), marsupials and amphibians (47%), marsupials and reptiles (45%) and marsupials and fish (37%). These data allow the incorporation of metatherians into the study of mammalian IgM evolution.

Amino Acid Sequence↗
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Association between smoking and drinking and sleep duration.

In a study of lifestyles and health of the adult population of some Oxfordshire villages, data were collected upon the usual sleep duration and quality, smoking and drinking habits of 725 men and 759 women. A strong negative association has been found between cigarette smoking and sleep duration on both sexes, and between alcohol consumption and sleep duration in men. There is no equivalent association between drinking or smoking and reported poor quality sleep. While these findings do not prove a causal relationship, the absence of complaints of poor quality sleep among the smokers and drinkers suggests that these habits are not simply the correlates of underlying psychological problems leading to insomnia.

Adolescent↗
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Catecholamine excretion rates in relation to life-styles in the male population of Otmoor, Oxfordshire.

The paper gives the results of the number of analyses of aspects of life-style and dietary patterns of members of the Otmoor population, in relation to their catecholamine excretion rates. The data reported here are restricted to males. Feelings of boredom were associated with low adrenaline excretion rates. Reported physical tiredness was associated with low adrenaline levels, while mental tiredness seems to be related to high adrenaline levels. People who regarded themselves as having a competitive personality, as being faced by a large number of life challenges, as having to meet self-set deadlines, as choosing to focus on more than one task at the same time, or as being under time pressure had high rates. Cigarette smoking and coffee consumption were related to high adrenaline excretion rates. Taken together these variables can explain 16-20% of variance in adrenaline excretion. Smoking and coffee consumption are of primary importance. The results of similar analyses of noradrenaline are reported.

Boredom↗
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Inter-population comparisons of urinary catecholamines: a pilot study.

Urinary catecholamine excretion rates, previously shown to be related to lifestyles and environmental influences, were investigated in three traditional-living populations and in an English population. Significant inter-population differences in excretion rates and in creatinine-related excretion were observed. These included high daytime levels of adrenaline output in the traditional groups relative to the English group. Methodological problems are discussed.

Adult↗
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Urinary hormone levels: a population study of associations between steroid and catecholamine excretion rates.

Urinary levels of steroid metabolites (17-hydroxycorticosteroids and 17-oxosteroids) were measured in 408 males at two times during the normal working day. Hormone levels are expressed both as rates of excretion and as creatinine ratios and are compared with the values for adrenaline and noradrenaline previously measured in the same samples. Strong associations are found between catecholamines and steroids. Generally the greatest correlation is with hormones of the same biochemical class, although the 17-hydroxycorticosteroid level is more strongly correlated with the adrenaline level than is the level of noradrenaline.

17-Hydroxycorticosteroids↗
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Associations between anthropometric variables and reproductive performance in a Papua New Guinea highland population.

Associations between anthropometric variation and reproductive performance have important ecological and evolutionary implications. Bivariate associations between measures of reproductive performance (live births and offspring still living at the time of interview) and 24 anthropometric variables were examined in 150 females, aged 21-44 years, from the Eastern Highlands district of Papua New Guinea. Where significant linear or curvilinear associations with age existed, the reproductive and anthropometric variables were age-corrected. Linear, quadratic and cubic regressions were computed for each bivariate regression of age-corrected reproductive variable on age-corrected anthropometric trait. Positive linear regressions were found in the cases of body weight, triceps skinfold and head breadth. Positive cubic regressions were found in the cases of upper arm circumference, calf circumference, bicondylar femur and wrist breadth. It is suggested that these associations may reflect important ecological factors which influence both anthropometric and reproductive variation. U-shaped associations were found in the cases of wrist breadth and bicondylar femur. Inverted U-shaped associations were found for stature, sitting height, bizygomatic diameter and morphological face height. These curvilinear associations may be interpreted in terms of natural selection, and suggest that stature and sitting height may be undergoing stabilizing selection in this population.

Adult↗
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Sleep latency and lifestyle in Oxfordshire villages.

Sleep latency, the usual delay in falling asleep, was estimated in 689 male and 757 female residents of a group of Oxfordshire villages by means of a sleep questionnaire. Sleep latency is analysed in relation to 59 descriptive elements of lifestyle and reported feelings. The pattern of association is broadly similar in the two sexes, and multivariate analysis identifies boredom and insufficient to do, mild morbidity, and use of sleeping tablets and tranquillizers as important correlates of long sleep latency in both sexes. These data are compared with a similar analysis of the correlates of sleep duration and sleep quality. It is concluded that sleep latency represents an important measure of well-being.

Adolescent↗
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Migration and the structure of the Otmoor villages.

Patterns of variation in I.Q., personality and stature are examined in the Otmoor region of Oxfordshire according to village of residence and whether people were born locally or not. It is shown that the locally born do not vary by village in I.Q., but that immigrants do and this is not solely due to social-class associations. Immigrants also have substantially higher I.Qs than those born locally. The findings are discussed in terms of the selectiveness of in-and-out migration.

Body Height↗
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Inter-population comparisons of catecholamine excretion.

Twenty-four hour urines were obtained from groups of male and female volunteers recruited from urban populations in developed and developing countries (UK, USA, Japan and Nigeria) an from agriculture-based Polynesian population (Tokelau Islands). The urines were collected on typical working days, with minimal disturbance to subjects' normal routines. High-performance liquid chromatography was used to determine catecholamine concentrations in each urine, providing a basis for calculation of total 24-hour excretion. Mean 24-hour excretion of noradrenaline and adrenaline was low in the Polynesians compared to the modern, urban groups, and low in women compared to men. Discussion of the results includes assessment of the possible influences of artefact, physical characteristics of the population samples, physical environment and social and psychological factors.

Age Factors↗
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Patterns in the within-population variability of stature and weight.

An analysis has been undertaken of the comparative magnitudes of the within-population variability in stature and body weight as reported in the recent literature. The distributions of the variability have been investigated for patterns related to latitude, altitude, 'affluence' and the mean value of the measurements. It is shown that differences in stature variability are substantially explained by differences in mean stature only. This however, is not the case with weight variability where, in addition to the mean, there is evidence of independent effects of affluence, altitude, and especially latitude. In most populations the weight of females is more variable than that of males. This is considered to be due to their greater amounts of fat, and differing levels of fat may also explain much of the geographical patterns in weight variability.

Altitude↗
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Variability in stature growth.

An analysis of longitudinal data shows that there are marked changes in the variability of stature and stature velocity during growth in stature, as measured by the coefficient of variation. Variability in stature velocity tends to rise after birth but from age 2 years it gradually declines until the end of adolescence, once variation in the timing of adolescence is taken into account. Comparison of velocity variation in an affluent western society (UK) with velocity variation in two poorer societies (India and Thailand) shows the former to be systematically smaller.

Adolescent↗
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Parotid gland enlargement and female reproductive performance in a Papua New Guinea highland population.

Swelling of the parotid salivary glands is commonly observed among males and females of highland Papua New Guinea. Evidence suggests that the condition is related to the highlanders' high starch consumption in the form of sweet potato. In this paper we regard parotid enlargement as an indicator of high energy intake and test its association with two measures of reproductive performance, the number of live births and living offspring, in a sample of 274 women from Lufa in the Eastern Highlands District of Papua New Guinea. Multiple regression analysis including maternal age showed that parotid enlargement is positively correlated with both measures of reproductive performance. Given that parotid gland enlargement in this population is due to persistent starch consumption, and that the condition represents above average energy intake, these results suggest that increases in energy intake relate to increases in reproductive performance in this sample of highland females.

Adult↗
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On correlations between adjacent velocities and accelerations in longitudinal growth data.

Correlations are examined between adjacent velocity and acceleration growth in stature, weight and skinfold thickness in a group of adolescent boys measured approximately quarterly. It is concluded that some substantial component of the variability behaves rather like measurement error, and this is likely to represent negative feedback homeostasis.

Acceleration↗
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Short-term variations in stature growth in Ethiopian and English children.

Two groups of young children, one in Addis Ababa and one in Oxford, were measured every calendar month for 6 months. Changes in their stature variability, as evidenced by increasing measurement interval length, are here compared. There is evidence for substantially greater variability in the Addis Ababa children. When the variability is expressed as coefficients of variation both groups show a marked decline with interval length, presumably as constant and additive components of variation become proportionally less important as the mean increases. One constant element is identified in the Addis Ababa children, since a single subtraction from all interval coefficients greater than two months produces the same CV. It is concluded that this probably represents the homeostatic cycle of catch-up growth in this group of children.

Body Height↗