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Biomedical subjects

R J Lawrence

Publications and source records attributed to R J Lawrence.

13 recordsLinked to original sources
PubMed1996

Wanted: designs for health in the urban environment.

Lessons have to be learnt from the mistakes and oversights for which planners have been responsible as urban populations have escalated during the latter half of the 20th century. For people living in densely populated cities the best possible health can only be achieved if due consideration is given to the creation of a broadly favourable environment. The causes of urban deprivation and ill health, and the approaches needed to tackling them, are discussed below, with special reference to conditions in European cities.

Adolescent↗
PubMed1984

Hypocalcaemia associated with high dose rates of zinc oxide to lactating dairy cows.

Clinical hypocalcaemia was associated with single doses of three oi more days; supply of zinc oxide to dairy cows for facial eczema control. Experimental hand dosing of a single dose of zinc oxide (40 and 120 mg Zn/kg b wt) to Jersey cows caused a significant drop in serum calcium concentration at 24 h followed by a rise to concentrations higher than controls at subsequent samplings over four days. At the highest zinc dose rate, 78% of serum calcium values were equal to or lower than the lowest control value at 24 h post dosing. Serum magnesium concentrations had a reciprocal relationship to the calcium levels at all samplings. Serum zinc concentrations were most elevated over the 48 h post dosing, returning to normal levels at the fifth day. Following the highest zinc dose milk yields were reduced by approximately 1.5 kg milk/cow/day for 48 h. Similar results were obtained when cows grazed pasture on which large amounts of zinc oxide had been sprayed.

Journal Article↗
PubMed1984

Natural history of carotid artery disease on the side contralateral to endarterectomy.

The natural history of the nonoperated carotid artery opposite an endarterectomy was examined in 134 patients by means of ultrasonic duplex scanning over a period extending to 48 months. None of the nine deaths that occurred during follow-up was stroke related. A total of 22 arteries showed progression of disease over this period. By life-table analysis the mean annual rate of progression for all categories of disease was 12.6% and 7.4% for progression to a diameter reduction greater than 50%. Disease progression was more rapid in patients under 65 years of age. Symptoms occurred in 13 patients for an overall incidence of 10% and a mean annual rate estimated at 5%. All symptoms indicated transient ischemic attacks; there were no strokes. There was a strong relationship between the development of symptoms and stenoses greater than 80% either at the initial examination or secondary to progression. No correlation was found between the presence of bruits or their change over time and the progression or appearance of symptoms. Conservative management of nonoperated vessels opposite an endarterectomy appears appropriate until symptoms develop or a lesion greater than 80% is detected.

Adult↗
PubMed1980

Trials with the Auditory Response Cradle. II--The neonatal respiratory response to an auditory stimulus.

The respiratory response of the neonate to an acoustic stimulus is analysed. It is shown that a response may be indicated by (i) a change in the mean cycle time, (ii) a change in the variability of cycle times, (iii) short or long cycles in the sound-on-period following a regular sequence prior to the stimulus. Responses were found to be independent of the pre-stimulus mean cycle time and variability subject to certain restriction. Decision rules are formulated and applied to the Auditory Response Cradle test results. Good agreement is found between statistical and visual methods of trace analysis.

Acoustic Stimulation↗
PubMedDate not supplied

Urban health: an ecological perspective.

At the Second European Conference on Environment and Health held in Helsinki in June 1994, urban health was attributed a high priority. This decision by the Ministers of Environment and Health from European countries reflects and reinforces a growing worldwide concern in the 1990s about the health status of residents of urban areas in all continents. The reasons for this concern include the rapid rate of urbanization and the increasing number of environmental, economic, and social problems, which have a negative impact on health and well-being in cities. This review presents a theoretical and methodological framework for the study of this vast and complex subject area. The paper proposes and illustrates an ecological perspective by discussing housing conditions and homelessness, as well as the concentration of poverty and deprivation in precise neighborhoods. To promote health and well-being more effectively, the ecological perspective presented in this paper can be applied by public health officers, by urban planners, and by policy decision-makers at national and local levels to promote our understanding of the multi-dimensional nature of health disorders of citizens. This approach should be a high priority for the beginning of the 21st century.

Ecosystem↗
PubMedDate not supplied

Liquid chromatographic determination of vitamin K1 in infant formulas and milk.

Vitamin K1 in infant formulas and milk products is determined by reversed-phase liquid chromatography (LC) with UV detection. The sample is hydrolyzed enzymatically, and the vitamin is extracted with hexane. Fractionation by normal-phase semi-preparative LC is followed by analytical LC, with quantitation by the internal standard technique. Recovery of the analyte was 97.4 +/- 2.8%. Linearity was established between 0.05 and 4.0 micrograms/mL. The limit of quantitation is 0.5 microgram/100 g for milk powder, which allows the method to quantitate endogenous levels of vitamin K1.

Animals↗