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Biomedical subjects

C J Henry

Publications and source records attributed to C J Henry.

At least 37 records · Page 2Linked to original sources
PubMed1998

Accuracy of fluorocrit in determination of blood perflubron concentration.

Previous studies examining the radiosensitizing effects of perfluorochemical emulsions have based dose recommendations on a measurement known as fluorocrit. The fluorocrit is the proportion of blood volume occupied by perfluorochemicals and is measured using standard hematocrit procedures. This measurement is inherently crude and subject to error and variability between different individuals measuring the same sample. Furthermore, the fluorocrit method has not been compared to other quantitative methods to determine its reliability. The purpose of this study was to compare fluorocrit measurements to those obtained by gas chromatographic analysis. A 90% w/v perflubron emulsion was administered to six normal dogs once weekly for four weeks and peripheral blood samples were obtained at specified time points for analysis. A total of 123 blood samples were analyzed by both methods. The relationship between blood fluorocrit and plasma perflubron concentration measured by gas chromatography was examined using regression models. Based on the modest predictive value (r2 = 0.3683) of the derived statistical model, we conclude that fluorocrit measurement is an inaccurate method of estimation of blood perflubron concentration. Caution must, therefore, be exercised when extrapolating data and dose recommendations from reports of studies using flurocrit as the only estimate of blood perflubron concentration.

Animals↗
PubMed1997

Gingival vascular hamartoma with associated paraneoplastic hyperglycemia in a kitten.

A 4-month-old domestic shorthair cat was examined because of a maxillary gingival mass that had regrown following excisional biopsy. The kitten also had a history of persistently high blood glucose concentrations, despite 2 weeks of insulin treatment. Radiography revealed maxillary alveolar bone lysis and displacement of multiple teeth. Partial maxillectomy was performed to remove the mass, which histologically was a gingival vascular hamartoma. Hyperglycemia permanently resolved < 24 hours after mass removal. On the basis of the temporal relationship between mass removal and resolution of hyperglycemia, as well as the lack of evidence of any concurrent disease, hyperglycemia in this cat was considered to be a paraneoplastic syndrome.

Animals↗
PubMed1997

Relationship between tissue mobilization and storage in the rat.

The amount of energy mobilized or stored as protein, expressed as a proportion of the total energy stored or mobilized (defined as the P ratio, Payne & Dugdale, 1977), was investigated in the young male (rapid growth) and adult female (slow growth) rat. Energy mobilization was induced by a 3 d fast and the changes in body content of fat and lean tissues were used to estimate the fasting P ratio (Pfast). Tissue storage was subsequently effected by 17 d of refeeding and the corresponding ratio (P(refed)) was calculated from the amounts of lean and fat tissue regained. The same experimental protocol was used for measuring Pfast and P(refed) in weanling (30 d) and adult (130 d) rats. Weight-matched individuals were assigned to three groups. All animals in group 1 were killed at the beginning of the experiment. Animals in group 2 were fasted for 3 d and then killed. Group 3 animals were first fasted for 3 d, then had free access to a stock diet for a further 17 d before being killed. During fasting, a close linear relationship was found between weight change and body energy changes (r 0.985, and r 0.92, P < 0.001 for weanlings and adult rats respectively) and between carcass N loss and urinary N loss (r 0.933, P < 0.001). These relationships were used to estimate the body energy and N content of each animal at the end of the initial fasting period. Hence, both Pfast and P(refed) values could be calculated for all individuals at both ages. When Pfast and P(refed) were calculated for adult rats, the mean values were similar (0.138 (SE 0.002) and 0.130 (SE 0.006) respectively). Individually, the Pfast and P(refed) values were correlated (r 0.54, P = 0.058). In weanling rats, the mean P(refed) value was about 2.5 times the Pfast (0.421 (SE 0.0113) v. 0.156 (SE 0.004)). Despite the differences in Pfast and p(refed), the individual values were again correlated (r 0.668, P < 0.05). These results support the suggestion made by Payne & Dugdale (1977), that particular P. ratio values are characteristic of individuals and describe the extent to which protein is mobilized or stored during fasting or refeeding. These observations are discussed in relations to the predictions made by the Payne-Dugdale model.

Animals↗
PubMed1996

Acute lymphoblastic leukemia, hypercalcemia, and pseudohyperkalemia in a dog.

A 5-month-old sexually intact male Chesapeake Bay Retriever was evaluated for lameness of 2 weeks' duration and lymphocytosis. Acute lymphoblastic leukemia was diagnosed on the basis of results of cytologic and cytochemical evaluation of a bone marrow aspirate. Serum biochemical abnormalities included hypercalcemia and hyperkalemia. Hypercalcemia was likely paraneoplastic; hyperkalemia was believed to be a result of release of potassium from large numbers of lymphocytes in vitro (pseudohyperkalemia). The dog was euthanatized, and necropsy revealed infiltration of the hepatic vasculature and sinusoids, renal parenchyma, mesenteric and peripheral lymph nodes, bone marrow, and iridial tissue with neoplastic cells. Unique features of this case include the young age of the dog and the hypercalcemia and hyperkalemia associated with acute lymphoblastic anemia.

Animals↗
PubMed1996

Protein utilization, growth and survival in essential-fatty-acid-deficient rats.

The relationship between essential fatty acids (EFA) deficiency and the utilization of dietary protein, growth rate and survival of offspring was investigated in rats during development and reproduction. EFA deficiency was induced by feeding a 200 g casein/kg-based diet containing 70 g hydrogenated coconut oil (HCO)/kg as the only source of fat. The conversion efficiency of dietary protein was assessed as net protein utilization (NPU), using a 10 d comparative carcass technique. Consumption of the deficient diet during the 10 d assay period induced biochemical changes characteristic of mild EFA deficiency in humans (triene:tetraene 0.27 (SD 0.04) compared with 0.026 (SD 0.004) for non-deficient controls), but there were no significant changes in growth rate or protein utilization. These variables were also unchanged when the deficient diet was fed for an additional 7 d before the assay, although triene:tetraene increased to 0.8 (SD 0.02). Feeding the deficient diet for 63 d before assay produced severe EFA deficiency (triene:tetraene 1.4 (SD 0.3) v. 0.036 (SD 0.005) for controls), a fall in growth rate (25% during assay period), and NPU (31.5 (SD 0.63) v. 39.0 (SD 0.93) for controls). These severely-EFA-deficient animals had a 30% higher fasting-resting rate of energy metabolism than that of age-matched controls. However, there was no change in the rate of endogenous N loss. Voluntary energy consumption was increased in animals fed on deficient diets, either with 200 g protein/kg, or protein free. The reduced efficiency of protein utilization could be entirely accounted for by the restricted amount of energy available for growth and protein deposition. Consumption of an EFA-deficient diet during pregnancy and lactation resulted in high mortality (11% survival rate at weaning compared with 79% for controls) and retarded growth in the preweaning offspring. It is concluded that animals are particularly sensitive to EFA deficiency during reproduction and pre- and post-natal stages of development. However, after weaning only severe EFA deficiency retarded growth, primarily through changes in energy balance.

Animals↗
PubMed1996

Basal metabolic rate of women on the contraceptive pill.

OBJECTIVE: To investigate the variability in basal metabolic rate (BMR) of women taking the contraceptive pill, through sequential measurement over the course of one menstrual cycle. DESIGN: Randomised. SETTING: Metabolic room, School of Biological and Molecular Sciences, Oxford Brookes University. SUBJECTS AND MEASUREMENTS: BMR of five weight-stable women taking the contraceptive pill, was measured three to four times each week for a period of five consecutive weeks, BMR was measured using a Douglas bag. RESULTS: The pattern of variation in BMR was random for individual subjects throughout the period of measurement. The level of intraindividual variation indicated by the coefficient of variation (CV) ranged from 2.4 to 4.87%. CONCLUSIONS: Women taking the contraceptive pill did not exhibit the cyclicity or variation in BMR observed in some normally ovulating subjects. BMR in women taking the contraceptive pill could therefore be considered a 'biological constant'.

Adult↗
PubMed1996

The relationship between arm-span measurement and height with special reference to gender and ethnicity.

OBJECTIVE: The relationship between height and arm-span measurement in both sexes and different ethnic groups was studied in order to assess the use of the arm-span measurement as a suitable proxy indicator for height. SETTING: School of Biological and Molecular Sciences, Oxford Brookes University. SUBJECTS: Five hundred and fifty-three subjects (272 male and 281 female) aged 23.3 years (s.d. 5.5). RESULTS: Correlation coefficients (r = 0.73-0.89) indicated a clear association between arm-span measurements and height in all groups. However, arm-span was found to be significantly different (P < 0.01) from height in two ethnic groups, the Afro-Caribbean's of both sexes and Asian males. This suggests that arm-span measurements may be an inappropriate proxy for height in certain populations. CONCLUSION: The arm-span measurement and height relationship is significantly different in Afro-Caribbean and Asian males. This suggests that any future studies attempting to use arm-span measurement as a proxy for height must consider these ethnic differences.

Adult↗