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Biomedical subjects

D Halliday

Publications and source records attributed to D Halliday.

At least 19 recordsLinked to original sources
PubMed1979

Site differences in the fatty acid composition of subcutaneous adipose tissue of obese women.

1. Adipose tissue samples were obtained by needle biopsy from three subcutaneous sites (thigh, abdomen and upper arm) in twenty-two obese women. The fatty acid composition was determined using gas-liquid chromatography and the results presented relate to eleven component fatty acids. 2. The fatty acid composition of adipose tissue obtained from the arm and abdomen was remarkably similar, with the exception of the levels of lauric acid. 3. The analyses showed that the majority of the saturated fatty acids were present in smaller proportions whilst the majority of unsaturated fatty acids were present in larger proportions in the thigh than in the two other sites. Highly significant inter-site differences were demonstrated for six of the major fatty acids and also for both the total amounts of saturated and unsaturated fatty acids and their ratios. 4. No marked differences in the fatty acid composition of adipose tissue from obese subjects were revealed during this study when compared with previously reported results obtained from 'normal-weight' subjects.

Abdomen↗
PubMed1979

A new method for measuring the body density of obese adults.

1. A new apparatus is described with which it is possible to measure the volume (and hence density) of obese patients without requiring them to immerse totally in water. Replicate measurements of subjects with 6, 23 and 38 kg body fat had a standard deviation not greater than 0.3 kg fat. 2. In nineteen obese women body fat was measured by density, total body water, and total body potassium at the beginning, and again at the end, of a period of 3--4 weeks on a reducing diet, during which they lost 5.43 (SD 1.83) kg in weight. The composition of weight loss was also estimated both by energy balance and nitrogen balance during the interval between the two measurements of body composition. 3. The estimates of fat content of the ninetten women at the start of the balance period were 45.63 (SD 14.50) kg by density, 48.07 (SD 13.88) kg by K and 47.09 (SD 13.85) kg by water. The correlation coefficient between the density and K estimate was 0.949, and for the density and water estimate it was 0.971. 4. It is concluded that measurement of density by the new method provides a convenient method for estimating body fatness, and change in fat content, which compares favourably with estimates based on total body water or total body K. However, these methods cannot be used to provide an accurate estimate of the composition of a small weight loss in an individual since deviations up to 4 kg fat occur between fat loss based on change in density and those based on the more reliable (but more tedious) energy balance method.

Adipose Tissue↗
PubMed1979

Changes in fat, fat-free mass and body water in human normal pregnancy.

Measurements of body weight, total body water and total body potassium (40K) were made serially on three occasions during pregnancy and once post partum in 27 normal pregnant women. Skinfold thickness and fat cell diameter were also measured. A model of body composition was formulated to permit the estimation of changes in fat, lean tissue and water content of the maternal body. Total maternal body fat increased during pregnancy, reaching a peak towards the end of the second trimester before diminishing. Serial measurements of fat cell diameter showed poor correlation, whilst total body fat calculated from skinfold thickness correlated well with our estimated values for total body fat in pregnancy.

Adipose Tissue↗
PubMed1979

3-Methylhistidine excretion as an index of myofibrillar protein catabolism in neuromuscular disease.

Myofibrillar protein catabolism has been calculated in a variety of neuromuscular diseases from the amount of 3-methylhistidine excreted in the urine. It was found to be significantly raised in Duchenne type muscular dystrophy, motor neurone disease, polymyositis, and thyrotoxic myopathy. In Becker type muscular dystrophy the level was slightly raised. It was normal in scapuloperoneal and limb girdle dystrophy, dystrophia myotonica, extrapyramidal disease, and multiple sclerosis. It was significantly decreased in hypothyroid myopathy.

Histidine↗
PubMed1979

Resting metabolic rate, weight, surface area and body composition in obese women.

Resting metabolic rate was measured in 22 women with varying degrees of obesity. Body composition was estimated from total body potassium and from total body water, and creatinine excretion in urine was measured over a period of three weeks while the patients were on a creatinine and creatine-free reducing diet. Resting metabolic rate was highly significantly correlated with body weight, surface area, creatinine excretion and lean body mass calculated either from potassium or water measurements (P less than 0.001). Correlation with adipose tissue was less strong, and when multiple regression of both fat and lean on metabolic rate was performed, the relationship was seen to depend mostly on the mass of lean rather than adipose tissue. In obese people the water content of fat-free tissue is greater than that in normal subjects, so it is not valid to assume that fat content can be calculated accurately from a measurement of total body water.

Adipose Tissue↗
PubMed1978

Sources of ammonia for mammalian urea synthesis.

The initial rate of incorporation of [15N]alanine into the 6-amino group of the adenine nucleotides in rat hepatocytes was about one-eighteenth of the rate of incorporation into urea. Thus the purine nucleotide cycle cannot provide most of the ammonia needed in urea synthesis for the carbamoyl phosphate synthase reaction (EC 2.7.2.5). On the other hand, contrary to the view expressed by McGivan & Chappell [(1975) FEBS Lett. 52, 1--7], the experiments support the view that hepatic glutamate dehydrogenase can supply the required ammonia.

Adenine Nucleotides↗
PubMed1978

Comparison of human myofibrillar protein catabolic rate derived from 3-methylhistidine excretion with synthetic rate from muscle biopsies during L-[alpha-15N]lysine infusion.

1. Urine was collected in five healthy men over 10--14 days, with fasting blood samples on days 1, 5 and 10, whilst they consumed a standard creatine-free diet, which was quantitatively related to their body surface area. 2. The urinary excretion of 3-methylhistidine fell to a plateau by day 5 in all subjects. Myofibrillar protein catabolic rate calculated from the mean value of 3-methylhistidine excretion from day 5 to day 10 averaged 1.21 g day-1 kg-1 body weight. The average turnover of muscle myofibrillar protein was calculated to be 2.16%/day. 3. From a previous study using continuous intravenous infusion of L-[alpha-15N]lysine with serial muscle biopsies on the same subjects, the mean myofibrillar protein synthetic rate was calculated to be 0.82 g day-1 kg-1 body weight, and the mean turnover rate was 1.47%/day of total muscle myofibrillar protein. 4. The estimations of myofibrillar protein turnover rate derived from the two methods are compared and the differences discussed.

Adult↗
PubMed1978

Metabolic studies with keto acid diets.

Five patients with chronic renal failure taking a diet containing approximately 5 g N throughout were studied during two periods of 1 month each. Nitrogen balance, urea metabolism, and incorporation of 15N from urea into albumin on diet alone or with a keto acid/essential amino acid supplement were measured. Keto acids produced a reduction of plasma urea, urea synthesis, and urea excretion and an improvement in nitrogen balance. In patients who demonstrated the greatest change on ketoacids, 15N incorporation also increased, but their total incorporation of urea nitrogen was not nearly sufficient to account for the improvement in nitrogen balance. The role of keto acids in protein anabolism is not solely or even mainly explained by promotion of nonprotein nitrogen reutilization.

Aged↗
PubMed1978

Anabolic role of urea in renal failure.

The amount of urea nitrogen released and the amount reincorporated into albumin has been measured in healthy and uremic individuals on both normal and low-protein diets. The albumin synthesis rate was measured simultaneously. Gut urea breakdown was only 50% higher in renal failure than in health, but the efficiency of utilization of the nitrogen thus released was increased more than 6-fold in renal failure and was higher on a low protein than on a normal protein diet. The lower the albumin synthetic rate, the greater was the efficiency of incorporation of urea nitrogen into albumin. The rate of urea nitrogen incorporation into albumin increased on average 14-fold in chronic renal failure. The absolute rate of utilization (84 mumole/hr) was, however, small and comprised on average only 2.4% of the nitrogen used in albumin synthesis. These findings suggest that although some urea derived nitrogen is incorporated into albumin, the amount is not nutritionally significant even under conditions of protein deprivation and high urea availability.

Albumins↗
PubMed1978

Detection of intracellular immunoglobulin in nodular lymphomas.

In lymph node tissue sections, six of 11 human cases of nodular lymphoma showed immunoglobulin within malignant nodules, and seven of nine cases of benign follicular hyperplasia showed immunoglobulin within follicles. In addition, distributions of lymphocyte cell membrane markers for T cells and B cells were determined in ten of 11 cases of nodular lymphoma. Lymphocyte suspensions in five cases contained monoclonal immunoglobulins and in three cases neoplastic cells showed a lack of surface membrane immunoglobulins. In two cases, the distribution of lymphocyte surface markers could not be distinguished from cells of benign lymph nodes. Combined data from intracytoplasmic immunoglobulin studies and lymphocyte surface marker assays indicated that eight of ten cases are of B cell lineage. Thus, the detection of intracellular immunoglobulin is not helpful in differentiating benign follicular hyperplasia from nodular lymphoma, but is complementary to lymphocyte surface marker assays in the determination of the origin of neoplastic cells in lymphoreticular malignancies.

Antibodies↗
PubMed1977

Direct evidence for synthesis of valine in man.

Plasma valine and 13C-valine concentrations were measured in 2 healthy volunteers and 2 uraemic patients during and after a 3-hour intravenous infusion of the 13-c-labelled alpha-keto-acid analogue of valine. Plasma-valine increased by 23-43%. 13C-valine accounted for most of the early increase, but for less than 30% of the increase 1 hour after infusion. It was concluded that valine had increased by 2 mechanisms with different time courses. Initially, transamination of the infused ketoacid predominated, confirming directly for the first time that the essential aminoacid valine can be synthesised in-vivo both in health and uraemia. The previously unsuspected second mechanism was quantitatively more important but slower in ooperation; it may prove to be the key to understanding the metabolic effects of essential aminoacid precursors.

Adult↗
PubMed1977

Increased myofibrillar protein catabolism in Duchenne muscular dystrophy measured by 3-methylhistidine excretion in the urine.

Myofibrillar protein catabolic rate was calculated in seven patients with Duchenne muscular dystrophy from the amount of 3-methylhistidine excreted in the urine, and found to be over three times that found in a control series when expresses as the percentage of myofibrillar protein catabolised per day. It is suggested that measurement of myofibrillar protein catabolic rate may add a useful parameter in the study of muscle disorders.

Adolescent↗
PubMed1977

Identification of intracellular immunoglobulin in extramedullary myeloma.

We describe a patient with multiple myeloma characterized by clinically evident extramedullary metastasis and marked anaplastic alterations of neoplastic cells. We describe the technique that detected the presence of intracytoplasmic immunoglobulin IgGk in mature plasma cells from paraffin-fixed tissue obtained from an iliac lesion and in anaplastic tumor cells infiltrating a lymph node from which a biopsy specimen was taken three years later. These data confirm that both tissues were composed of a cell with identical origin. In addition, the immunohistochemical technique is applicable for the identification of other antigens present in paraffin-embedded tissue.

Aged↗