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Biomedical subjects

J M Norton

Publications and source records attributed to J M Norton.

At least 37 records · Page 2Linked to original sources
PubMed1981

Decreased deformability of erythrocytes from smokers.

The deformability of erythrocytes from smoking and non-smoking human subjects was examined by filtration through 3-mu pores and capillary viscometry of cell suspensions. In both cases, small but significant differences were found between the two groups that are consistent with a reduction in the surface area-to-volume ratio and/or a diminished membrane flexibility in erythrocyte from smokers. Additional evidence suggests that these findings represent a chronic rather than an acute effect of smoking on erythrocyte deformability.

Animals↗
PubMed1980

A relationship between erythrocyte volume and concentration in humans and other mammals.

In 33 male and female human blood samples, red cell count decreased in a highly significant (p < 0.01) non-linear fashion as MCV increased. An identical, equally significant relationship was obtained using published hematologic values for 20 other mammalian species. These findings suggest a hyperbolic relationship between RCC and MCV, with the latter as the independent variable.

Animals↗
PubMed1980

In vitro actions of glucocorticoids on murine macrophages: effects on glucose transport and metabolism, growth in culture, and protein synthesis.

In vitro exposure of homogeneous monolayer cultures of thioglycollate-elicited mouse peritoneal macrophages to glucocorticoid hormones for up to 96 hr produced a progressive, dose-related inhibition of cell growth and protein synthesis. The reductions in cell protein, incorporation of radiolabeled leucine, and intracellular water space were specific to steroids with glucocorticoid action, with half-maximal inhibition occurring at about 10(-9) M for dexamethasone. Similar dose-related, glucocorticoid-specific decreases in net glucose uptake, lactate production, and 14CO2 production were observed that were only partially explained by the decrease in cell mass. A decrease in the monosaccharide transport system Vmax was also noted but could be completely accounted for by the reduction in cell surface area and the resulting proportional loss in transport sites. No effect on transport system affinity could be demonstrated. The suggestion was made that such long-term culture of macrophages in the presence of glucocorticoids reverses the biochemical and functional changes that comprise the "activated" state of mononuclear phagocytes.

Animals↗
PubMed1975

Effects of shifts in hemoglobin-oxygen affinity during hypoxia.

To investigate the possibility that the influence of hemoglobin-oxygen affinity on tissue oxygenation may be reversed in severe hypoxia, 16 anesthetized rabbits with chronically-implanted tissue oxygen electrodes were ventilated with 12% oxygen and subjected to 100 ml exchange transfusions with high, low, or normal affinity rabbit blood. Despite the widely divergent in vivo P50 values produced, significant differences in tissue oxygen levels were not observed among the three groups following exchange transfusions. During subsequent normoxia, more complete recovery of tissue oxygen was apparent in the low affinity group. This study emphasizes the need for further definition of the influence of hemoglobin-oxygen affinity on the functions of individual organs.

Animals↗
PubMedDate not supplied

Dental health of Louisiana residents based on the ten-state nutrition survey.

The dental health status of 4,006 residents of Louisiana was analyzed, based on data in the 1968-70 Ten-State Nutrition Survey funded by the U.S. Government. These data were based on examinations of census districts in which the average per capita income was in the lowest quartile for the nation. A considerable variation in the prevalence of dental diseases was found among the Louisiana residents according to age. The females examined had a slightly higher DMF (decayed, missing, and filled permanent teeth) score, a lower OHI (oral hygiene index) score, and a slightly lower PI (periodontal index) score than did the males. The dental caries attack rate did not vary much by race, but the whites examined had received a much greater amount of dental care than had their black counterparts. The OHI scores of the blacks were higher than those for the whites in both the debris and calculus components. The PI scores were higher for the blacks than for the whites. More white persons than blacks were edentulous; this result, however, tends to confirm the observation of increased dental care in white persons. The percentages of persons with periodontal disease and periodontal pockets were considerably higher among persons with incomes below the poverty level, and a greater percentage of blacks had incomes below that level. The data thus apparently indicate that the major determinants of dental health status in Lousiana are age and level of income; race appears to be the major determinant of the amount of dental care received.

Adolescent↗