Biomedical subjects

B Hicks

Publications and source records attributed to B Hicks.

25 records · Page 2Linked to original sources

PubMed1978

Flash photolysis of human serum albumin: characterization of the indole triplet absorption spectrum and decay at ambient temperature.

The method of flash photolysis was used to identify the transient absorption spectrum and to characterize the decay kinetics of the indole triplet of human serum albumin. This protein was studied because it contains a single indole side chain which is deeply buried in an expandable oily region and because the phosphorescence of the homologous indole in bovine serum albumin could not be detected at ambient temperatures. The transient was identified on the following basis: (i) its triplet-triplet absorption spectrum was similar to those previously reported for indole and tryptophan; (ii) it was quenched by small quantities of oxygen; and (iii) it was photobleached by 370- to 700-nm light. In a nitrogen-saturated solution at room temperature, the indole triplet decays exponentially for more than a factor of 10 with a lifetime of 0.5 msec. These observations suggest that, because of its exponential decay and relatively long lifetime, the triplet will be more valuable than the indole singlet as an intrinsic reporter group for the study of the structure and dynamics of proteins in solution.

Humans↗

PubMed1978

Influence of dietary biotin level on growth, metabolism and pathology of rainbow trout.

Supplementation of a dry diet containing herring and soybean meals with D biotin had no effect on the feed comsumption, growth or mortality of rainbow trout in a 28 week experiment. In a second experiment two series of diets were used: practical, based upon herring and soybean meals, and purified, based upon casein and gelatin. The basal levels of biotin in the two series of diets were: 0.51 and 0 mg/kg, respectively. There were four treatment groups in each of the two diet series: the practical diets were either supplemented with 0.5 mg D biotin/kg or 10% of either raw or heated egg white was added to the diet. The purified diets were supplemented with graded levels of D biotin (0, 0.25 0.5, or 1.0 mg/kg). Raw egg white (1%) was added to the biotin unsupplemented diet. Feeding these diets to rainbow trout for 24 weeks showed that both the practical diet containing egg white, and the unsupplemented, purified diet were biotin deficient, all the other diets contained adequate amounts of biotin to support growth and prevent mortality. Neither supplementation of the practical diet nor adding more than 0.25 mg D biotin/kg to the purified diet resulted in any improvement in growth however the biotin levels in the livers were greater for the fish which had received the higher levels of dietary biotin, but these increased levels of biotin did not influence the activity of acetyl CoA carboxylase. The biotin deficient fish were anorexic, and exhibited degeneration of the gills: shortening and thickening of the lamellae and hypertrophy and hyperplasia of the heterogenous epithelial cells of the lamellae.

Acetyl-CoA Carboxylase↗

PubMed1977

Cost-effectiveness analysis and alternative health care programs for the elderly.

A generalized cost-effectiveness technique for comparing alternative health care programs is described, and an example is given of its use in evaluating programs for care of the elderly. The analytical method requires setting criteria and standards for each outcome and cost dimension and assessing the relationship between these standards and patient status. The relative effectiveness and costs of each setting are examined in a simple tabular display that allows comparison of each program's attainments on each criterion so that alternatives may be ranked according to the extent to which they meet standards and incur costs.

Aged↗

PubMed1974

Effects of lactulose and other laxatives on ileal and colonic pH as measured by a radiotelemetry device.

Using a pH-sensitive radiotelemetering device the effect of lactulose on luminal pH in the ileum, colon, and rectum has been compared with that of two other laxative agents. Lactulose produced marked acidification of proximal colonic contents but this effect was not consistently maintained into the distal colon. Sodium sulphate acidified distal rather than proximal colonic contents. However, for a similar degree of laxation it was not possible to produce a significantly more uniform reduction of pH along the length of the colon by combining these laxatives compared with lactulose alone. Magnesium sulphate had little effect upon luminal pH except in the rectum where a significant rise occurred. These results are discussed in relation to both normal colonic physiology and to their possible relevance to the treatment of chronic hepatic encephalopathy by colonic acidification.

Adult↗

PubMed1970

Steroids.

Explore the source record for details and available documents.

Adrenal Cortex Hormones↗

PubMedDate not supplied

A controlled study of the effect of computer-aided analysis of home blood glucose monitoring on blood glucose control.

A 6-month study of the effects on blood glucose control of computer-aided analysis of glucose self-monitoring results was performed. Eighteen clinically insulin-dependent patients were ranked in order of haemoglobin A1 and randomly allocated in consecutive pairs to either a conventional group, using diaries to record self-monitoring meter-read results, or a memory group using meters with inbuilt memories which were linked to a computer at each visit for the analysis of self-monitoring results. There was a significant decline in haemoglobin A1 (p less than 0.001) and fructosamine (p = 0.002) over the 6-month period in the whole population but there was no difference between the study groups. The absolute or percentage changes in haemoglobin A1 and fructosamine did not correlate significantly with any of the patient characteristics examined. The memory system was popular with the patients. At present no benefit in terms of blood glucose control from such systems has been demonstrated.

Adult↗

PubMedDate not supplied

The diabetic rat as an impaired wound healing model: stimulatory effects of transforming growth factor-beta and basic fibroblast growth factor.

Two models of wound repair compared the effect of defined, recombinant growth factors on the rate of wound repair in both normal and streptozotocin-induced diabetic rats: subcutaneous implantation of polyvinyl alcohol sponges and incisional wounding. Transverse incisional wounds were made on the dorsal surface of rats and closed with steel sutures. Three days postwounding the rats received a single injection of either transforming growth factor-beta or vehicle alone directly into the wound site. Animals were sacrificed 7, 14, and 21 days postwounding, and fresh and formalin-fixed wound tensile strength were measured. Diabetic rats had expected defects in wound repair, including decreased granulation tissue and reduced amounts of collagen, protein, and DNA. Fresh tensile strength of the diabetic incisions was 53% of normal on Day 7 (p < or = .01) and 29% of normal on Day 21. Fixed tensile strength was 41% of normal on Day 7 (p < or = .01) and fell to 78% of normal by Day 21 (p < or = .01), suggesting that collagen concentrations of diabetic wounds increased towards normal but did not undergo maturation. TGF beta produced a moderate increase in tensile strength of fresh and fixed wounds of diabetic rats, but not to the levels of wounds in untreated normal rats. Sponges fill with granulation tissue, their reproducible rate of organization being measured by histological and biochemical methods. A single injection into sponges 3 days postimplantation of basic fibroblast growth factor, transforming growth factor-beta, or vehicle only, was evaluated at 7 and 9 days postimplantation. In the sponge model, bFGF and TGF beta were each able to induce significant increases in the accumulation of granulation tissue in both diabetic and normal rats. TGF beta increased the collagen content of sponges by 136% in sponges from diabetic animals (p < or = .001), thereby raising the collagen content to that of normal control wounds, while stimulating a 49% (p < or = .02) increase in sponges from normal animals on Day 9. By contrast, the response to bFGF was predominantly an increase in the protein and DNA content of the sponges. These results emphasize the differential effects of the two cytokines in accelerating healing under conditions of defective wound repair.

Animals↗