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Biomedical subjects

D R Davis

Publications and source records attributed to D R Davis.

At least 145 records · Page 8Linked to original sources
PubMed1979

Impaired fertility in the jaundiced female (Gunn) rat.

The hyperbilirubinemic female Gunn rat has been reported to have impaired fertility. A total of 267 jaundiced (j/j) and 91 nonjaundiced (+/j) female Gunn rats were used in a series of experiments to characterize the nature of this reduced fertility. Sixteen percent of the jaundiced females mated and delivered litters which were characteristically small in number (4.5 pups). A comparison of the gross observations at necropsy of jaundiced and nonjaundiced pregnant rats indicated that the number of implantation sites and live fetuses were significantly lower in the jaundiced females. The number of fetal resorptions in these rats were significantly higher; whereas, the number of corpra lutea was similar for both genotypes. The significantly lower plasma bilirubin levels in the pregnant jaundiced rats compared to the nonpregnant suggested that the observed effect on fertility was related to the concentration of plasma bilirubin.

Animals↗
PubMed1978

Diet and retarded growth.

The diets of 36 children below the third centile for height but with no organic disease were compared with the diets of a control group. In most cases retarded growth was associated with a long-continued deficiency in calorie intake. When the diets were reassessed about a year later the shortfall in calorie intake was significantly reduced. This improvement, which tended to be followed by an increase in the rate of growth in height, might have been due to alteration in the child's circumstances or improvement in the family attitudes and feeding habits or both. Advice given at the clinic is thought to have played a part in bringing these changes about.

Adolescent↗
PubMed1977

Effects of bilirubin on glucuronidation of p-nitrophenol and morphine.

Addition of bilirubin in vitro to hepatic microsomes or 9,333 g supernatant activated UDP glucuronyltransferase activity (UDPGT) for p-nitrophenol of livers from Sprague-Dawley rats, Wistar rats, icteric Gunn rats and nonicteric Gunn rats. However, injection of bilirubin at subtoxic doses using a variety of regimens failed to produce detectable activation of UDPGT in intact or bile duct-ligated rats. Pretreatment with intraperitoneal injections of bilirubin increased the rate of morphine glucuronide excretion in both Sprague-Dawley and icteric Gunn rats. Sulfadimethoxine did not affect morphin e excretion in Gunn rats. The data suggest that activation of UDPGT is of little, if any, significance in hyperbilirubinemia although the basis for increased excretion of morphine following bilirubin pretreatment has not been established.

Animals↗
PubMed1977

Measurement of drug displacement of protein-bound bilirubin using gel filtration.

Gel filtration was used to measure drug interaction with protein-bound bilirubin in 0.5 ml samples of Gunn rat serum, human serum and fraction V human serum albumin. Using sulfadimethoxine as a prototype differences in displacement were found in all 3 sera. The differences between human and rat serum were related to the binding characteristics of sulfadimethoxine whereas the differences between human serum and fraction V human serum albumin were attributed to displacement of bilirubin from albumin to other proteins in serum. Gel filtration permitted the use of small samples with bilirubin-albumin ratios less than 1.0 and provided data that were used for analysis of drug displacement of bilirubin using principles of drug-receptor theory. Ten of 14 drugs found to alter serum bilirubin concentrations in icteric Gunn rats had measurable effects on protein binding of bilirubin.

Animals↗
PubMed1976

Potentially useful criteria for judging nutritional adequacy.

Four different diets designed to be of differing quality were fed to large groups of male weanling rats. These diets were: diet C consisting of commercial Rat Chow: diet CG, the same diet diluted with 70% glucose calories, diet A, a simulated "American" diet made up of 25 widely used foods, diet AS, the same diet supplemented with small amounts of 25 vitamins and minerals. The rats on these four diets were observed for 69 days under different circumstances and treatments to ascertain the existence of hitherto unused criteria which might advantageously be applied in nutritional studies. Among the less traditional criteria found to be significantly affected by the diet were: 1) voluntary consumption of food, 2) sleeping time after anesthesia, 3) weight gains after surgery, 4) healing time after surgery, 5) hair growth after clipping, 6) voluntary sugar consumption, and 7) recovery time after cyanide poisoning. These findings suggest that there are probably many other unexplored criteria which could be used advantageously in nutritional experimentation.

Anesthesia, Intravenous↗
PubMed1976

Forearm fractures in children: pitfalls and complications.

Five hundred fourty-seven consecutive forearm fractures in children were studied, with special emphasis on complications encountered. The most important apparent conclusion reached from this study is that greenstick and complete fractures are different, and that some of the pitfalls and complications seen following these injuries can be avoided if different methods of reduction are used for each. Greenstick fractures should be reduced by manipulating them into the correct proper plane of rotation; i.e., maximum pronation for distal third fractures, neutral for middle third fractures, and supination for proximal third fractures. Application of this familiar "rule of thirds" to complete fractures, however, may result in ratational deformity at the fracture site. Completer fractures should be reduced by finger trap traction, allowing the fracture to seek its own level of rotation. Several other observations were also noted. Angulation into radial deviation was found to remodel and equally as well as volar angulation, and remodeling may contine for as long as two years after injury. Growth disturbance following fractures through the distal radial epiphyseal plate is uncommon, but premature closure of the epiphysis did occur in one patient with a typical Type II fracture. Six concomitant nerve injuries were seen; all recovered spontaneously within 3 weeks.

Adolescent↗
PubMed1975

Effects of sulfadimethoxine on tissue distribution of (14C)bilirubin in the newborn and adult hyperbilirubinemic Gunn rate.

Sulfadimethoxine significantly reduced plasma bilirubin levels and altered the tissue bilirubin distribution in both the newborn and the adult Gunn rat. The majority of the unbound bilirubin appeared to distribute perferentially to the intestine and liver in the newborn, whereas in the adult the unbound bilirubin was taken up primarily by the liver. The bilirubin content of brain tissue from both age groups was significantly higher after sulfadimethoxine treatment.

Animals↗
PubMed1975

Bilirubin binding to hepatic Y and Z protein (ligandin): tissue bilirubin concentrations in phenobarbital treated Gunn rats (38466).

NaP treatment significantly reduced plasma bilirubin levels in the (jj) Gunn rat. It is suggested that NaP significantly increased extravascular bilirubin binding in the liver by induction of the synthesis of Y anion binding protein. The changes in bilirubin concentration of blood and other tissues subsequent to NaP treatment were consistent with the establishment of a new tissue bilirubin equilibrium.

Adipose Tissue↗