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Biomedical subjects

J R Freeman

Publications and source records attributed to J R Freeman.

11 recordsLinked to original sources
PubMed1990

Effects of intermittent feeding upon body weight and lifespan in inbred mice: interaction of genotype and age.

Beginning at either 1.5, 6 or 10 months of age, male mice from the A/J and C57BL/6J strains and their F1 hybrid, B6AF1/J were fed a diet (4.2 kcal/g) either ad libitum every day or in a restricted fashion by ad libitum feeding every other day. Relative to estimates for ad libitum controls, the body weights of the intermittently-fed restricted C57BL/6J and hybrid mice were reduced and mean and maximum life span were incremented when the every-other-day regimen was initiated at 1.5 or 6 months of age. When every-other-day feeding was introduced at 10 months of age, again both these genotypes lost body weight relative to controls; however, mean life span was not significantly affected although maximum life span was increased. Among A/J mice, intermittent feeding did not reduce body weight relative to ad libitum controls when introduced at 1.5 or 10 months of age; however, this treatment did increase mean and maximum life span when begun at 1.5 months, while it decreased mean and maximum life span when begun at 10 months. When restricted feeding was introduced to this genotype at 6 months of age, body weight reduction compared to control values was apparent at some ages, but the treatment had no significant effects on mean or maximum life span. These results illustrate that the effects of particular regimens of dietary restriction on body weight and life span are greatly dependent upon the genotype and age of initiation. Moreover, when examining the relationship of body weight to life span both between and within the various groups, it was clear that the complexity of this relationship made it difficult to predict that lower body weight would induce life span increment.

Aging↗
PubMed1990

Treatment of comminuted distal radial fractures with preliminary horizontal finger trap traction and a Roger-Anderson external fixation device.

Over a five-year period, 43 patients with comminuted distal radial fractures were treated with a Roger-Anderson external fixation device after the fracture was aligned in Strong's horizontal finger trap traction. Nineteen patients (21 wrists) were available for personal interview and radiographic follow-up. A 0.5-mm loss of radial height and an average loss of 2.4 degrees of palmar angulation presented. Range of motion (ROM) was excellent, stiffness was nonexistent or minimal in 81%, pain was nonexistent or minimal in 86%, and weakness of grasp was nonexistent or minimal in 81%. Complications were minimal; they included three pin tract infections, two of which required pin removal before they resolved. One patient fractured a pin that also required removal. Strong's horizontal finger trap traction and the Roger-Anderson external fixation device simplified the sometimes difficult treatment of this fracture. It seems to be most effective in young athletic individuals who have good bone stock and very comminuted fractures.

Adult↗
PubMed1987

Dietary restriction benefits learning and motor performance of aged mice.

Female C3B10RF1 mice maintained on either a control (approximately 95 kcal/week) or restricted (approximately 55 kcal/week) diet since weaning were tested in a behavioral battery at 11 to 15 or 31 to 35 months of age (middle-aged vs. aged). Age-related declines observed among control groups in tests of motor coordination (rotorod) and learning (complex maze) were prevented by the restriction regime. In addition, diet restriction increased locomotor activity in a runwheel cage among mice of both ages but did not affect exploratory activity in a novel arena.

Aging↗
PubMed1987

Changing patterns in tibial fractures resulting from skiing.

Of the 734 adult tibial fractures treated in Aspen, Colorado, from 1968-1978, follow-up results were obtained on 527 (72%). The fractures were analyzed with regard to rate of healing, age of patient, and location of fractures. There was a statistically significant increase in healing time with increasing age between ages 16-40. The location of tibial fracture (proximal, middle, distal) had no significant influence on rate of healing. The occurrence of open tibial fracture was low (3% of total) and in most instances wounds were benign (Class I). Compartment syndrome is rarely encountered in skiing fracture because of the relatively low energy involved. All tibial fractures occurring between 1982-1984 were reviewed and compared to the earlier series. This comparison confirmed the continual overall decline in rate of tibial fracture from skiing (from 12.9/100,000 skier days in 1968 to 2.9/100,000 skier days in 1983). This decline was primarily in spiral fractures (from 70% of total in 1968 to 50% in 1983). The percent of transverse fractures was unchanged (+/- 15%) while the percent of short oblique fractures increased from 11% to 33%. Properly adjusted and maintained safety equipment afforded reasonable protection from spiral fractures of the tibia, but a conceptual departure from the current release binding design would be required to protect against the benign moments that produced transverse and short oblique fracture. The current treatment philosophy is based on fracture type and the availability or experience with newer treatment modes.

Adolescent↗
PubMed1987

Acute surgical repair of the skier's thumb.

Complete ulnar collateral ligament tears incurred during the period fall 1977 through spring 1979 were treated under regional anesthesia by a single group of surgeons in an identical fashion as outpatients. Of 123 thumbs repaired, 69 (59%) were available for follow-up examination. There were 34 women and 35 men with an average age of 34.5 years (range, 16-61 years). The follow-up period averaged 31.6 months (range, 16-46 months). Weakness of pinch was described as none or mild in 66 (96%) and significant in only three (4%). Stiffness was described as none or mild in 66 (96%), moderate in two (3%), and severe in one (1%). Pain was described as none or mild in 68 (99%) and moderate in one (1%). Sixty-two patients (90%) preferred outpatient surgery with regional anesthesia whereas only seven (10%) did not. Forty-five (65%) of the 69 patients who required surgery had used traditional poles with straps, suggesting the pole as the causative factor. However, only 20% of noninjured skiers during the 1981-1982 season were using traditional poles with straps, and the total number of complete ulnar collateral ligament repairs did not decrease with the same number of skiers. Therefore, the change in pole design has not decreased the incidence of total ulnar collateral ligament tears. The results of acute surgical repair as an outpatient with regional anesthesia are excellent; 96% of the patients were pleased with the results. If the lesion is overlooked, the results of secondary construction are not nearly as good.

Adolescent↗
PubMed1985

Primary knee ligament repair--revisited.

There were 4710 knee sprains resulting from skiing in the four Aspen ski areas between 1976 and 1979. Twenty percent of the patients (942) had complete tears. Of these, 302 elected to remain in Aspen for treatment. All were treated by primary ligament repair without augmentation. These cases were evaluated an average of 42 months after injury. Patients with isolated tears of the medial collateral ligament were found to be doing well; virtually all of them had returned to preinjury activity levels. Thirty-six percent of the isolated anterior cruciate repairs were rated failures, and 43% of the combination ACL-MCL injuries had failed because of anterior cruciate deficiency. Twenty-nine percent of the ACL and ACL-MCL injuries had meniscal tears. Cases that included meniscectomy had a failure rate twice as great as those in which the meniscus was preserved. The results following repair of anterior cruciate tears were not acceptable, and augmentation was indicated. Primary repair of medial collateral ligament tears produced excellent results. Meniscal tears were frequent in association with ligament disruption. Ligament repairs were less satisfactory when meniscectomy was performed at the time of the repair.

Athletic Injuries↗
PubMed1983

Effects of intermittent feeding upon growth, activity, and lifespan in rats allowed voluntary exercise.

From weaning until death, male Wistar rats were housed in activity-wheel cages with one group maintained on an ad libitum (AL) diet and another provided the diet every-other-day (EOD). EOD-fed rats had a mean lifespan of 124 weeks compared to 103 weeks for AL-fed rats. While post-weaning body weight and growth rates were reduced among the EOD-fed animals compared to AL-fed animals, there was no significant difference in growth duration. Positive correlations were observed between lifespan and estimates of growth rate and duration in the AL group but not in the EOD group; thus, little evidence was produced to support the hypothesis that growth rate is inversely related to longevity. While the EOD feeding regimen resulted in higher activity levels later in life, wheel activity levels were actually lower in this group in early life compared to the AL group. The observation of reduced wheel activity among young rats fed EOD was replicated in a second experiment. Thus, little support was obtained for the hypothesis that increased activity mediates the beneficial effects of dietary restriction on longevity, unless this mechanism is active late in the lifespan.

Animals↗
PubMed1983

Differential effects of intermittent feeding and voluntary exercise on body weight and lifespan in adult rats.

Male wistar rats were housed in laboratory cages or activity-wheel cages at eight 10.5 or 18 months of age. Part of each cage group continued to be fed ad libitum, whereas the remaining animals were fed every other day. Compared with the ad libitum condition, intermittent feeding decreased body weight and increased lifespan at both ages in both caging conditions. Compared with the caged condition, voluntary exercise in activity wheels reduced body weight only in the 10.5-month-old group fed ad libitum but produced no effect on survival of either age group. The results suggest that intermittent feeding can enhance survival in mature rats even beyond ages at which body weight growth usually ceases, whereas voluntary exercise appears to have an early threshold beyond which increases in longevity are not observed.

Animals↗
PubMed1970

Systems engineering.

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