PubMed Health⌕ Search

Biomedical subjects

D Hewitt

Publications and source records attributed to D Hewitt.

34 records · Page 2Linked to original sources
PubMed1977

Normative standards of plasma cholesterol and triglyceride concentrations in Canadians of working age.

Fasting plasma cholesterol and triglyceride concentrations were determined for 6407 working Canadian adults aged 20 to 69 years in Toronto and Hamilton. Means, medians and 5th and 95th percentiles were ascertained from the data for men, women taking oral contraceptives or estrogen preparations, and women not taking such medication. Mean plasma cholesterol values (mg/dL) ranged in men from 168.3 at ages 20 to 24 years to 211.5 at ages 45 to 49 years, and in women using hormone preparations from 180.3 at ages 20 to 24 years to 224.2 at ages 50 to 54 years; corresponding values in women not using these preparations were 164.9 and 220.6. Plasma triglyceride means (mg/dL) ranged in men from 108.7 at ages 20 to 24 years to 166.7 at ages 40 to 44 years, in women using hormone preparations from 115.4 at ages 20 to 24 years to 145.3 at ages 45 to 59 years, and in women not using these preparations from 77.5 at ages 20 to 24 years to 112.4 at ages 50 to 54 years.

Adult↗
PubMed1976

The role of the gut microflora in the utilization of dietary urea by the chick.

1. In a preliminary experiment, growth of conventional chicks given a basal diet containing adequate amounts of all the essential but none of the non-essential amino acids was improved by supplements of 10-3 g urea or 50-4 g glutamic acid/kg diet or both. 2. In the main study the effects of supplementing the basal diet with 20-6 g urea/kg were compared in groups of sixteen germ-free and conventional chicks. 3. The germ-free chicks did not benefit from the urea supplement whereas the conventional birds showed improved food conversion efficiency and significantly better growth. 4. In both environments nitrogen retention ((mg N intake-mg N excreted)divideg food intake) was higher in the birds given urea, but N utilization ((mg N intake-mg N excreted)dividemg N intake) was reduced. This reduction was greater in the germ-free birds. 5. There was a small increase in plasma ammonia concentration in the germ-free birds given urea but a significantly greater increase in the corresponding conventional group. 6. Plasma uric acid concentrations were variable in both groups, and much lower than the normal range. They followed a similar pattern to the plasma ammonia values. 7. More insoluble N was excreted by the conventional chicks given urea than by the corresponding germ-free group, or by either group given the basal diet. 8. It was concluded that the gut micro-organisms are responsible for the growth-promoting effect of urea, presumably through release of ammonia by bacterial ureas (EC 3.5.1.5) and its consequent incorporation into amino acids.

Amino Acids, Essential↗
PubMed1975

Chronic obstructive pulmonary disease in two cities of contrasting air quality.

Spirometric tests of 3280 Ottawa residents in 1969-71 and 2208 Sudbury residents in 1972-73 showed that the mean ratio of forced vital capacity to forced expiratory volume in 1 second was lower in Sudbury, where sulfur dioxide concentrations in the air tend to be appreciably higher than in Ottawa. This difference was significant for both males and females considered separately, and held true when age and smoking habits were taken into account. The prevalence of symptomatic chronic bronchitis was significantly higher in Sudbury males than in Ottawa males, but no such difference could be detected in females.

Adolescent↗
PubMed1975

Heterodox practitioners and the availability of specialist advice.

The characteristics of the principal categories of more professional heterodox practice are examined. It is concluded that rheumatic diseases are one of the likeliest fields for conflcit between orthodox and fringe medicine. The distribution of manpower engaged in alternative systems of health care is compared with that of orthodox medical services. The limited data on utilization of unorthodox remedies are reviewed. Far from conflict ensuing, it is argued that dialogue must develop in order to submit procedures like manipulation to satisfactory clinical trial.

Acupuncture Therapy↗
PubMed1975

Inequality of the services received by individuals: a suggested index and an illustrative application.

Population groups that are homogeneous with respect to such factors as insurance status, income level, and proximity to sources of care can still exhibit great internal inequality in the amount of care received by individuals. A statistical measure of this inequality is proposed and its application illustrated on employee groups living in two underdoctored areas. Utilization of physician services in these areas was found to be significantly less equal (as well as lower) than in comparable groups who live in areas with higher ratio of physicians to total population.

Adult↗
PubMed1975

Protein quality of feeding-stuffs. 7. Collaborative studies on the microbiological assay of available amino acids.

1. Twenty-two samples of high-protein feeding-stuffs, sixteen of them fish meals, were used in a collaborative study of the precision and the limits of discrimination of the Streptococcus zymogenes assay procedure, as applied to the estimation of available methionine, tryptophan and isoleucine contents. 2. All the participating laboratories ranked the test samples in much the same sequence with respect to content for all three amino acids. There were apparently systematic differences between laboratories which impaired the precision of some of the estimates, and these were greatly reduced by including common reference sample in the tests as an auxilliary standard. 3. Values for available methionine content for eleven test samples were highly correlated (r 0.86) and quantitatively similar to those obtained for chick growth assays, but those for available tryptophan content were markedly lower and were probably in error.

Amino Acids↗