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Biomedical subjects

L Chin

Publications and source records attributed to L Chin.

107 records · Page 6Linked to original sources
PubMed1966

Liquid water in frozen tissue: study by nuclear magnetic resonance.

Nuclear magnetic resonance (NMR) spectroscopy was used to examine the behavior and extent of liquid water in postrigor-frozen tissue of cod at temperatures below 0 degrees C. A liquid-water phase persists in the tissue down to about -70 degrees C; the extent of the phase decreases rapidly between 0 degrees and -10 degrees C and slowly at lower temperatures. That the NMR absorption peak of the liquid water increases in width, with decreasing temperature, suggests loss of mobility or structuring of the phase. A technique for introducing geometrically uniform cores of muscle into the probe of the high-resolution spectrometer permits quantitative determinations of liquid water.

Animals↗
PubMedDate not supplied

A transformed human epithelial cell line that retains tight junctions post crisis.

The successful establishment of a postcrisis SV-40 T antigen transformed epithelial cell line, 1HAEo-, which retains tight junctions and vectorial ion transport, is described. Immunocytochemical analysis of 1HAEo- cells shows a defined pattern of cytokeratin staining and a characteristic pericellular localization of the adhesion molecule cellCAM 120/80, indicating the presence of junctional complexes. The presence of both tight junctions and desmosomes has been confirmed by electron microscopy. Cell monolayers have good transepithelial resistance measured in Ussing chambers. Cells increase chloride ion transport in response to addition of agents that raise either intracellular cAMP or calcium, measured either by 36Cl- efflux or whole-cell patch clamp. An increase in short-circuit current, in response to these agents, can be measured in Ussing chambers. The presence of a depolarization-induced outwardly rectifying 45 pS chloride channel has been demonstrated in single cell detached membrane patches. In addition, the cells have been found to express mucin mRNA. These cells therefore demonstrate that it is possible to select transformed cell clones with particular morphologic characteristics, i.e. the presence of tight junctions and cell polarity, which also retain useful epithelial cell-specific functions, including vectorial ion transport. They also provide a major resource for the study of the structure and function of human epithelia.

Base Sequence↗
PubMedDate not supplied

Delta-9-tetrahydrocannabinol, EEG and behavior:the importance of adaptation to the testing milieu.

Delta-9-Tetrahydrocannabinol (delta-9-THC) in doses of 0.01, 0.05, 0.1, 0.5, and 1.0 mg/kg, i.v. was administered to adult rabbits previously adapted to the testing chamber. Additionally, a group of rabbits not adapted to any part of the testing regimen was administered 1.0 mg/kg delta-9-THC. Cortical and hippocampal electroencephalographs as well as postural and activity behaviors of the unrestrained animals were recorded. In the adapted rabbits, there were dose-related increased in cortical voltage output, disruption of hippocampal theta rhythm and cortical polyspike bursts. Behaviorally, there was a dose-related tendency for standing and exploration to decrease, and at 0.5 and 1.0 mg/lh, delta-9-THC produced sprawling. In the nonadapted rabbits, administration of 1.0 mg/kh of the drug caused EEG and behavioral stimulation followed by depression of both, The results suggest that the bahavioral actions of cannabinols are largely dependent upon the animal's existing state of arousal.

Adaptation, Physiological↗
PubMedDate not supplied

Breast self-examination: the effects of prescribed frequency on adherence, accuracy, and detection ability.

The purpose of our study was to determine the effects of prescribed rates of breast self-examination (BSE) on reported frequency of BSE per year. Fifty-one women were divided at random into three groups: a weekly prescription, every-two-weeks prescription, and monthly prescription. All women were trained to competence prior to receiving their prescription for BSE. A repeated-measures ANOVA showed that all three groups of women significantly increased (p less than .05) the number of BSE steps performed after training. Significant (p less than .05) differences among groups were observed for reported BSE frequency. The women who were prescribed weekly exams averaged over 14 a year, the two-week group averaged over 11 a year, and the monthly group averaged over seven a year. It was concluded that BSE frequency could be enhanced by a more frequent prescription (e.g., weekly). These results require confirmation with more representative (i.e., older) women prior to generalization.

Adolescent↗