Protein and energy relationships in the diet of the American alligator (Alligator mississippiensis)

First-year alligators (Alligator mississippiensis) averaging 377-857 g body weight were fed diets containing various levels of protein, fat and carbohydrate. In experiment 1, nine diets arranged in a centrally rotatable composite design contained 0-36% extruded corn and 4-20% total fat. Response surface analysis predicted maximum responses in performance criteria at 6.3-18.8% corn and 15.8-27.4% fat. Corn inclusion at up to 27-36% of diet resulted in equal or improved performance compared to carbohydrate-free diets of equal fat content. Energy digestibility averaged 84.3%. Protein digestibility averaged 86.7%. Maximum responses in performance criteria were predicted at 42.5-48.7% digestible protein and 4367-4421 kcal/kg digestible energy. In two additional experiments, alligators were either fasted or fed for various numbers of days/week. Carbohydrate-supplementation of high protein diets led to equal or significantly improved performances. Performance was maximized by feeding the alligators 5-6 d/w. Regression of body weight changes against energy and protein intake yielded estimates of daily maintenance requirements of 5.7-8.4 kcal and 0.49-0.89 g protein/kg live body weight. Dietary fat and carbohydrate in the forms and amounts fed to young alligators were well-utilized. Optimal digestible energy:crude protein ratios (8.2-10.9:1 kcal/g protein) were similar to those of other aquatic ectotherms of equal size.     

Preoperative superselective arteriolar embolization: a new approach to enhance resectability of spinal tumors

The extent of surgical resection of spinal tumors is frequently limited by blood loss and technical difficulty associated with the vascularity of the tumors. We report here the use of superselective percutaneous arterial embolization to reduce the rate of blood loss at the time of surgical resection and enhance resectability. The types of tumors treated were metastatic renal carcinoma, metastatic thyroid carcinoma, metastatic melanoma, and giant cell tumor of the sacrum. Two of the patients required repeated embolization and surgery for recurrent symptoms. The estimated blood loss in seven of nine procedures performed on the six patients ranged from 300 to 800 ml, after which no transfusion was required. In two procedures, extensive resection of very large tumors resulted in larger losses of blood, and postoperative transfusion was necessary. No significant complications of embolization or surgery occurred. A key factor in our embolization technique is the use of microfibrillar collagen, which allows occlusion of tumor vessels as small as 20 microns and may prevent reconstitution of the embolized vessels by collateral flow. We conclude that preoperative arterial embolization enhances the resectability of a variety of spinal tumors by reducing intraoperative blood loss. This may provide an additional benefit by reducing the risk related to postoperative transfusion. By permitting a more aggressive surgical approach, the use of preoperative embolization also has the potential to improve outcome in patients with spinal tumors.     

COMMERCE OR CON: YOUNG PEOPLE AND CIGARETTE ADVERTISING

One thousand two hundred and fifty-four adolescents in Hamilton, New Zealand, ranging in age from 10 to 16, were questioned on their awareness of, and attitudes towards, cigarette advertising, and on their image of the young smoker. Most of the respondents felt that tobacco companies advertise to encourage people to buy their brands. Smokers were less likely than non-smokers to feel that cigarette companies advertise to encourage young people to take up smoking. They were also more likely to agree that cigarette companies are generous, public spirited people. Non-smokers were more likely to feel that cigarette advertising was effective in encouraging young people to smoke. Winfield, the most popular brand among smokers, was also the most well known. Smokers had a more positive image than non-smokers of the young person who smokes.     

Retinopathy of prematurity in infants less than 29 weeks' gestation at birth

From January 1986 to December 1991 we examined the eyes of 206 infants born at Westmead Hospital, Neonatal Intensive Care Unit who were less than 29 weeks' gestation at birth to determine the incidence of retinopathy of prematurity. Eighty-five infants (41.3%) had no retinopathy of prematurity (ROP) in either eye, 82 infants had stages 1 or 2 ROP (39.8%), 29 had stage 3 ROP (14.1%) and 11 had stage 4 ROP (5.3%). Of these, cryotherapy was performed in 18; six now have bilateral retinal detachment and are blind The more severe stages of ROP were significantly associated with an increase in the number of days of oxygen supplementation, an increase in the number of days of mechanical ventilation and the presence of patent ductus arteriosus. Infants receiving steroids for mechanical ventilator dependence had a significantly greater chance of requiring cryotherapy (11 or 22 receiving steroids versus seven of 43 without steroids; P < 0.01).     

Induction of collagenase synthesis in chondrocytes by a factor synthesized by inflamed synovial tissue

Rabbit inflamed synovial tissue grown in culture synthesizes a factor that induces collagenase synthesis in chondrocytes and in cartilage. Synthesis of this factor by the synovial tissue is inhibited by cycloheximide but not by indomethacin. The factor has an apparent molecular weight of 30,000, is stable to heat and to trypsin treatment but is inactivated by acid. Induction of collagenase synthesis in chondrocytes occurs after a lag period of 6 hours.