Biomedical subjects

L D Anderson

Publications and source records attributed to L D Anderson.

At least 73 records · Page 4Linked to original sources

PubMed1977

Hormonal regulation of the number and activity of ribosomes in mammary gland explants of mice.

Possible effects of insulin, hydrocortisone and prolactin on the number and activity of ribosomes enganged in protein biosynthesis in mammary gland explants were explored. The rate and extent of [3H]-puromycin attachment to nascent peptides was used to assess, respectively, the activity and number of ribosomes engaged in protein biosynthesis. None of the hormones altered the number of ribosomes engaged in protein biosynthesis. In addition, of the hormones tested, only insulin appeared to accelerate the rate at which ribosomes carried out the translocation process. The early (1 hr) effect of insulin on protein biosynthesis in the mammary gland would therefore appear to occur via an activation of ribosomal activity. In contrast, the early (6 hr.) effect of prolactin on protein biosynthesis would appear to be exclusively via an RNA-DNA dependent mechanism.

Animals↗

PubMed1976

Effects of hormones on protein and amino acid metabolism in mammary-gland explants of mice.

The effects of insulin, cortisol and prolactin on amino acid uptake and protein biosynthesis were determined in mammary-gland explants from mid-pregnant mice. Insulin stimulated [3H]leucine incorporation into protein within 15 min of adding insulin to the incubation medium. Insulin also had a rapid stimulatory effect on the rate of aminoiso[14C]butyric acid uptake, but it had no effect on the intracellular accumulation of [3H]leucine. Cortisol inhibited the rate of [3H]leucine incorporation into protein during the initial 4h of incubation, but it had no effect at subsequent times. [3H]Leucine uptake was unaffected by cortisol, but amino[14C]isobutyric acid uptake was inhibited after a 4h exposure period to this hormone. Prolactin stimulated the rate of [3H]leucine incorporation into protein when tissues were exposed to this hormone for 4h or more; up to 4h, however, no effect of prolactin was detected. At all times tested, prolactin had no effect on the uptake of either amino[14C]isobutyric acid or [3H]leucine. Incubation with actinomycin D abolished the prolactin stimulation of protein biosynthesis, but this antibiotic did not affect the insulin response. A distinct difference in the mechanism of action of these hormones on protein biosynthesis in the mammary gland is thus apparent.

Aminoisobutyric Acids↗

PubMed1976

Phospholipases and the effect of prolactin on uridine incorporation into RNA in mammary gland explants of mice.

The possible effects of phospholipase A and phospholipase C on the rate of uridine incorporation into RNA in mammary gland explants of mice were tested. Phospholipase C had no effect on the rate of uridine incorporation, but it did suppress the action of prolactin on this metabolic parameter. In contrast, phospholipase A was found to stimulate the rate of uridine incorporation into RNA in a manner similar to that of prolactin. The time-courses for the onset of the prolactin and phospholipase A effects were the same. Also, the phospholipase A effect was nonadditive to the effect produced by a maximally stimulatory concentration of prolactin. Finally it was observed that, like the prolactin effect, the phospholipase A effect was abolished by incubation with dibutyryl cyclic AMP, theophylline, quinine, indomethacin and prostaglandin E1. Further, the phospholipase A effect was nonadditive to the prolactin-like effects produced by the cyclic GMP, prostaglandin F2alpha or arachidonic acid. These data therefore suggest that prolactin and phospholipase A stimulate RNA synthesis in mammary gland explants via similar processes.

Animals↗

PubMed1976

Rapid interaction of prolactin with mouse mammary gland explants.

Exposure of mouse mammary gland explants to prolactin at 0 degrees C, for periods as brief as 10 seconds, caused a stimulation of labeled uridine incorporation into RNA during a subsequent incubation for 4 h at 37 degrees C. Furthermore, a 2-h wash of the prolactin-exposed explants in media at 0 degrees C did not attenuate the hormonal effect. A similar exposure of explants to insulin, followed by a 2-h wash at 0 degrees C, caused the abolition of the insulin stimulation of labeled uridine incorporation into RNA. The results suggest that there is a rapid and relatively stable interaction of prolactin with the mammary gland, while the interaction of insulin with this tissue would appear to be less stable.

Animals↗

PubMed1975

Urinary incontinence due to ectopic ureter in a male dog.

Urinary incontinence was associated with an ectopic ureter in a 5-month-old, male Wire Fox Terrier. The dog regained urinary continence after transplantation of the ureter from the urethra into the urinary bladder. Of the 3 reported cases of extopic ureters in male dogs, 2 have been associated with urinary incontinence. These observations do not support the hypothesis that ectopic ureters are more frequently recognized in female than in male dogs because urinary incontinence is more commonly associated with the disorder in female dogs.

Animals↗

PubMed1975

Primary prosthetic replacement for femoral neck fractures.

Treatment of displaced femoral neck fractures remains a problem. Routine prosthetic replacement is controversial. Review of 100 patients treated at the Campbell Clinic from 1957 to 1966 suggests that 60% long-term good results can be anticipated at a cost of 5% mortality and 25% morbidity. We believe prosthetic replacement probably should be restricted to (1) those patients admitted for treatment late or those in whom previous internal fixation has failed, (2) elderly patients whose fracture cannot be reduced closed, and (3) patients with special circumstances such as pathologic fractures, seizure disorders, Parkinsonism, and so on.

Age Factors↗

PubMed1975

Compression-plate fixation in acute diaphyseal fractures of the radius and ulna.

At the Campbell Clinic and City of Memphis Hospital from 1960 to 1970, 244 patients (216 with closed and twenty-eight with open fractures) had 330 acute diaphyseal fractures of the radius and ulna which were treated with ASIF compression plates and followed for from four months to nine years. One hundred and twelve patients had fractures of both bones of the forearm; fifty, single fractures of the ulna; and eighty-two, single fractures of the radius. In all, 193 fractures of the radius and 137 fractures of the ulna were treated by compression plating. Sixty-three patients (25.9 per cent) with severely comminuted fractures also had iliac-bone grafts. The over-all rate of union for the radius was 97.9 per cent and for the ulna, 96.3 per cent. ASIF compression plates, therefore, provided a successful method for obtaining union and restoring optimum function after acute diaphyseal fractures of the forearm.

Acute Disease↗

PubMed1974