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Biomedical subjects

B L Bennett

Publications and source records attributed to B L Bennett.

7 recordsLinked to original sources
PubMed1991

Whey proteins of the common brushtail possum (Trichosurus vulpecula): isolation, characterization and changes in concentration in milk during lactation of transferrin, alpha-lactalbumin and serum albumin.

1. Transferrin and serum albumin were purified from both whey and serum and alpha-lactalbumin was purified from whey from the common brushtail possum (Trichosurus vulpecula). 2. The N-terminal amino acid sequences for transferrin and serum albumin were identical for the proteins from both whey and serum and showed homologies with transferrin or serum albumin from other species. 3. N- and C-terminal regions of possum alpha-lactalbumin were also sequenced and have been compared with wallaby alpha-lactalbumin and several eutherian alpha-lactalbumins. 4. Antisera raised to each of the three proteins were species specific and Western blots further confirmed the identity of the serum and whey transferrins and serum and whey serum albumins. 5. The concentration of transferrin increased ten-fold between days 110 and 130 of lactation, whereas no significant changes in the concentration of alpha-lactalbumin could be detected after day 60.

Amino Acid Sequence↗
PubMed1987

Physical fitness in a submarine community as determined by the U.S. Navy Health and Physical Readiness Test.

This study was conducted to test the hypothesis that personnel assigned to submarine duty would display less physical fitness as compared to shore-based personnel. A message was submitted to all naval activities at a Naval Submarine Base requesting individual test scores from the annual Health and Physical Readiness (H&PR) Test. The results from the statistical analysis showed that the majority of personnel in both populations were classified as "good," which is an average level of physical fitness as determined by the Navy's fitness classification table. In both populations, 1% were classified as "outstanding," while approximately 10% failed to meet the minimum physical fitness requirements. A body fat value greater than 22% was the cause for the majority of test failures. In conclusion, the results of the analysis of H&PR data do not support the widely held belief that submarine personnel are less physically fit than their shore-based counterparts.

Adolescent↗
PubMed1985

Cardiorespiratory fitness and cognitive performance before and after confinement in a nuclear submarine.

The aim of this study was to further document physiological deconditioning from occupational exposure to submarines as described in a small number of reports and determine whether cognitive performance parallels the physiological changes associated with physical training and deconditioning. We examined cardiorespiratory fitness and cognitive performance in 14 male subjects during 70 d of confinement in a nuclear submarine. Maximal oxygen consumption (VO2max) and anaerobic threshold (AT) were assessed before and after confinement. Six exercising subjects (ES) cycled 4-7 times per week for 20 min at 75% max heart rate for 8 weeks. Eight control subjects (CS) did no exercise. Every 14 d of the patrol, cognitive performance was evaluated in both groups by administering a mental arithmetic and choice reaction time tests before cycling, during cycling, and post cycling. The cycle bout consisted of exercising at 75% VO2max for 15 min. After confinement, VO2max remained constant for ES but declined 7% statistically nonsignificant for the CS. AT expressed as a percentage of VO2max increased 15% (p less than 0.05) in the ES and decreased 20% (p less than 0.05) in the CS. The only significant effect in the cognitive tests was that both groups responded faster in the choice reaction time test during the exercise session. In conclusion, these data demonstrate a training effect for AT in the ES and a deconditioning response for AT and a statistically nonsignificant reduction in VO2max in the CS. Under the conditions of this experiment we could find no effects of physical training and deconditioning on the cognitive performance test employed here, although some trends suggest that exercisers out-performed the control group.

Adult↗
PubMed1982

Is there a probenecid sensitive transport system for monoamine catabolites at the level of the brain capillary plexus?

Probenecid inhibits the transport of the small monocarboxylic acids lactate and propionate from blood to brain but does not affect the transport of 5HIAA or HVA. Neither lactate, 5HIAA, HVA, nor probenecid itself inhibits probenecid uptake into brain from blood and neither lactate nor 5HIAA itself inhibits 5HIAA uptake. These results indicate first that probenecid inhibits the lactate carrier but is itself not transported by that carrier and second that 5HIAA and probenecid are independently transported from blood to brain by a low affinity system, probably by diffusion. Preloading animals with both tryptophan and probenecid increased the apparent transport of lactate, probenecid and 5HIAA but not the transport of glucose. This indicates that the transport of 5HIAA, lactate and probenecid from brain to blood involves a common, saturable carrier. These two sets of data indicate that either the brain capillary transport system is asymmetric or that probenecid-inhibited transport of monoamine catabolites from brain occurs at sites other than the capillary transport system of the blood-brain barrier.

Animals↗