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Biomedical subjects

R W Morris

Publications and source records attributed to R W Morris.

At least 199 records · Page 11Linked to original sources
PubMed1967

Piezoelectric property of otoliths.

Otoliths of two species of bony fishes have been found to be piezoelectric. Hence, in theory, they constitute a mechanism for depth perception or frequency analysis of sound waves, or both.

Animals↗
PubMed1967

Circadian periodicity in susceptibility to lidocaine hydrochloride.

Separate groups of mice standardized in an alternating 12-hour-light,12-hour-dark regimen were treated with lidocaine hydrochloride every 3 hours over a 24-hour period. The results indicate a quantitative circadian periodicity with maximal convulsant activity at 2100 hours which was approximately a fourteen fold increase over the values observed at 1500 hours.

Animals↗
PubMedDate not supplied

Standard of weight-for-height for English children from age 5.0 to 11.0 years.

Analysis of data from the National Study of Health and Growth confirms the need to take age into account when assessing weight-for-height of children aged 5+ to 10+. The method described by Cole leads to errors in the assessment of English and Scottish children, in particular of those tall for their age. This is mainly because the method employs a log(weight)-log(height) rather than a log(weight)-height relationship. Using the latter, weight-for-height centiles are calculated using data for 7157 English boys and girls. It is shown that age last birthday is a precise enough measure of age for the assessment of prepubertal children. Charts of weight-for-height standards are given in an appendix.

Age Factors↗
PubMedDate not supplied

National study of health and growth: social and family factors and overweight in English and Scottish parents.

Lower social class, several children, and overweight partner and increasing age were factors significantly associated with overweight in parents aged 20-55 years in England and Scotland. These associations were greater for women than men in both countries. These results support the contention that social circumstances contribute to overweight in adults. However, both the magnitude of the explained variation and the relative risk of each factor for overweight were low. We conclude that the selection of families for preventive health measures using the above risk factors would exclude a large proportion of the population who will become obese.

Adult↗
PubMedDate not supplied

Monitoring the developmental examination schedule in an inner city health district.

Returns of scheduled school entry examinations, from 838 primary school children in West Lambeth Health Authority, were analysed to assess the possible association of a child's home language background, age, sex, behaviour, and examiner with the results of the developmental examination. To allow for variation in social characteristics between participating schools, a ward index of deprivation based on the 1981 census was assigned to all the children in the schools of each ward. Variables representing development were most consistently associated with the child's behaviour during the examination and with the examiner. A child's home language background was associated only with the auditory memory test. The child's ability to concentrate during the test situation was closely related to his performance. With respect to the examiners, it is suggested that community health services need to consider schemes of ongoing in-service training and careful calibration of the tests.

Child Language↗
PubMedDate not supplied

Serum lipids and lipoproteins in insulin-dependent diabetic patients with persistent microalbuminuria.

Serum lipid and lipoprotein concentrations were measured in 18 insulin-dependent diabetic patients with persistent microalbuminuria and an equal number with persistently normal albumin excretion. The groups were matched for sex, age, duration of diabetes, body mass index, insulin dose, and glycosylated haemoglobin. Diabetic patients with persistent microalbuminuria were found to have a significantly lower high density lipoprotein (HDL) cholesterol concentration (difference 0.29, 95% Cl 0.12 to 0.46, mmol l-1, p less than 0.01) and a higher low density lipoprotein (LDL) cholesterol:HDL cholesterol ratio (difference 0.97, 95% Cl 0.29 to 1.65, p less than 0.01) than patients with normal albumin excretion. No significant differences were found in total cholesterol, triglycerides, LDL cholesterol, apolipoprotein (apo) A-I and apo B concentrations. Compared to an age and sex-matched group of non-diabetic subjects with normal albumin excretion, diabetic patients with persistent microalbuminuria had significantly higher concentrations of total cholesterol (p less than 0.05), LDL cholesterol (p less than 0.05) and apo B (p less than 0.01), but a lower concentration of HDL cholesterol (p less than 0.05). No significant differences were found in serum lipids and lipoproteins between diabetic patients with normal albumin excretion and non-diabetic subjects.

Albuminuria↗
PubMedDate not supplied

Spontaneous neoplasm incidences in Fischer 344 rats and B6C3F1 mice in two-year carcinogenicity studies: a National Toxicology Program update.

Spontaneous neoplasm rates were determined for control Fischer 344 (F344) rats and B6C3F1 mice from 2-yr rodent carcinogenicity studies carried out by the National Toxicology Program (NTP). The most frequently occurring neoplasms in untreated male F344 rats were testicular adenoma (89.1%), mononuclear cell leukemia (50.5%), adrenal gland pheochromocytoma (31.9%), and pituitary gland neoplasms (30.4%). For untreated female F344 rats, the most frequently occurring neoplasms were pituitary gland neoplasms (54.2%), mammary gland fibroadenoma (41.2%), and mononuclear cell leukemia (28.1%). The most frequently occurring neoplasms in untreated male B6C3F1 mice were liver adenoma/carcinoma (42.2%), lung adenoma/carcinoma (20.5%), and malignant lymphoma (8.3%). For untreated female B6C3F1 mice, the most frequently occurring neoplasms were liver adenoma/carcinoma (23.6%), malignant lymphoma (20.9%), and pituitary gland adenoma/carcinoma (14.8%). The tumor rates observed in feeding study (untreated) and inhalation study (chamber) control rats were generally similar. The major exceptions were pituitary gland tumors and testicular adenoma in male F344 rats. The overall incidence of testicular adenoma was much lower in chamber controls (69.4%) than in feeding study controls (89.1%), whereas pituitary gland neoplasm showed the opposite trend (60.7% vs 30.4%). The most likely explanation for this difference is related to the individual housing of chamber controls and the group housing of feeding study controls. Differences in diagnostic criteria may influence reported tumor rates. To ensure consistency and comparability of tumor diagnosis from study to study, the NTP uses rigorous histopathology quality assurance and peer review procedures. Biological factors such as body weight may also affect tumor incidence. For example, increased body weights are associated with increased incidences of certain site-specific neoplasms, especially pituitary gland and mammary gland neoplasms in rats and liver tumors in mice. The presence of Helicobacter hepaticus has been associated with an increased incidence of liver neoplasms in male B6C3F1 mice. Other factors that may produce differences in control tumor rates from study to study include diet, environmental factors, genetic drift, study duration, and survival differences. The NTP database provides historical control data that may be useful in the evaluation of possible chemically related changes in tumor incidence. However, it is essential that the study being evaluated be comparable to those in the NTP database with respect to those factors that are known to influence tumor occurrence.

Animals↗
PubMedDate not supplied

Urinary N-acetyl-beta-D-glucosaminidase excretion in insulin-dependent diabetes mellitus: relation to microalbuminuria, retinopathy and glycaemic control.

N-Acetyl-beta-D-glucosaminidase (NAG) excretion was measured in early morning urine samples from 133 Albustix-negative, normotensive insulin-dependent diabetic patients and 89 non-diabetic controls. Urinary NAG activity was determined using a chromogenic substrate, 2 methoxy-4-(2'-nitrovinyl)-phenyl 2-acetamido-3-deoxy-beta-D-glucopyranoside, and expressed as mumol MNP released/hour/mmol of creatinine. Overall, diabetic patients were found to have a significantly elevated mean urinary NAG activity (p less than 0.01) compared to controls. Within the diabetic patients urinary NAG activity was significantly elevated in patients with either microalbuminuria (p less than 0.001) or "poor" glycaemic control (p less than 0.001), but not in those with retinopathy (p = 0.117). Three-way analysis of variance revealed that the relationship of raised urinary NAG to microalbuminuria and "poor" glycaemic control were statistically independent. Elevated urinary NAG excretion in insulin-dependent diabetes mellitus appears to be associated with early diabetic nephropathy and poor long-term glycaemic control.

Acetylglucosaminidase↗
PubMedDate not supplied

The effects of selected fungicides and insecticides on growth and thebaine production of Papaver bracteatum.

The fungicides benlate, maneb, and captan depressed plant growth, thebaine concentration, and thebaine yield per plant when administered chronically to Papaver bracteatum. The chronic administration of dicofol inhibited plant growth and thebaine yield per plant, but did not affect thebaine concentration. Malathion and pyrethrins had no adverse effects on either plant growth or thebaine content.

Fungicides, Industrial↗