PubMed Health⌕ Search

Biomedical subjects

E Mok

Publications and source records attributed to E Mok.

25 records · Page 2Linked to original sources

High resolution proton magnetic resonance spectroscopy of human brain and liver.

Water-suppressed and slice-selective proton spectra of live human brain exhibited several resonances that were tentatively assigned to metabolites such as N-acetylaspartate, glutamate, phosphocreatine and creatine, choline derivatives, and taurine. In the liver spectrum of a healthy volunteer, the major resonance was tentatively assigned to a fatty acyl methylene and the minor resonances to protons in carnitine, taurine, glutamate, and glutamine. In the spectrum of a cancerous liver, resonances in addition to those present in the normal liver were seen. Protein degradation in the liver with cancer was indicated by resonances from urea and from the ring protons in tryptophan, tyrosine, and phenylalanine. Furthermore, increased nucleic acid synthesis was indicated by resonances from nucleotide protons.

Brain↗

Effect of diet textural characteristics on the temporal rhythms of feeding in rats.

To examine whether the diurnal rhythms of protein-rich and carbohydrate-rich diet ingestion can be altered by presenting the diets in different textural forms, adult male Wistar rats were assigned to two dietary groups. One group received a two-way choice between high-protein powder and high-carbohydrate granular (HPP-HCG) diets. In the other group the textures were reversed [high-protein granular and high-carbohydrate powder (HPG-HCP) diets]. Rats fed HPP-HCG diets selected significantly less protein (kcal) vs. rats fed HPG-HCP diets, during the 24-h and 12-h dark phase and during the 4-h early and late dark phases. Carbohydrate intakes of the two dietary groups were not significantly different. Total caloric intake for the HPG-HCP dietary group was significantly higher than that of the HPP-HCG dietary group during the 24-h and 12-h dark phase. Body weight was significantly lower in rats fed HPP-HCG diets. In conclusion, macronutrient-rich diets presented in different textural forms alter protein-rich diet ingestion and total energy intake.

Animal Feed↗

Serotonin infusion in the SCN reduces casein ingestion in rats.

To compare food and water intakes, adult male Wistar rats were infused during 7 days with serotonin (5-HT, 2.5 nmol/24 h) or artificial cerebrospinal fluid (CSF) in the suprachiasmatic nucleus (SCN) in a three-way selection of macronutrient-rich diets. Nocturnal energy intake from the casein-rich diet was significantly lower during infusion of 5-HT than before infusion. Decrease in nocturnal casein consumption was significant in the middle dark phase. Within the infusion period, water intake was reduced by 5-HT infusion during the early, middle and late light phase. The present results reinforce the hypothesis of a serotonergic control of water intake and provide evidence for SCN 5-HT involvement in casein-specific dietary selection.

Animals↗

A photon dose distribution model employing convolution calculations.

A three-dimensional photon beam calculation is described which models the primary, first-scatter, and multiple-scatter dose components from first principles. Three key features of the model are (1) a multiple-scatter calculation based on diffusion theory, (2) the demonstration of the modulation transfer function of the radiation dose transport process, and (3) the use of the finite fast Fourier transform to perform the required convolutions. The results of calculations for cobalt-60 in a homogeneous phantom are used to verify the accuracy of the model.

Fourier Analysis↗