Equilibrium-dialysis studies of the interaction between cholic acid and 100000g-supernatant preparations from the rat liver

1. The binding of cholic acid to 100000g supernatants from rat livers was investigated by equilibrium dialysis and gel-exculsion chromatography. 2. Supernatants were found to contain at least two classes of binding site for cholic acid. 3. These recptor molecules are probably proteins since incubation with proteolytic enzymes resulted in complete loss of cholic acid binding. 4. Supernatants were added to columns of Sephadex G-75, and two groups of fractions were shown to bind cholic acid. One of these contained low-affinity binding sites and the other contained both low- and high-affinity binding sites. 5. Feeding cholestyramine had no effect on cholic acid binding. 6. Increased cholic acid binding occurred after injection of phenobarbitone. There was an increase in the amount of the low-affinity component but no change in the high-affinity component. 7. The dissociation constants of the binding of cholic acid suggest that the binding proteins may be involved in bile acid transport.     

Congenital stricture of male urethra

It was intendet to characterize the isoenzymes of serum alkaline phosphatase in healthy infants. Quantitative estimation of the activity of serum alkaline phosphatase resulted in relatively low values in the newborns and a distinct increase during the first three months of live. As a rule most of the newborns appeared to present one uniform isoenzyme fraction, which was comparable to the isoenzyme of bone origin of the adult. Some of the newborns already exhibited another less marked isoenzyme, the isoenzyme of liver origin. During babyhood this isoenzyme becomes more and more distinct. In most cases this development had become perfect at the end of the first year. Liver tissue of newborns apparently does not synthesize the same liver isoenzyme as liver tissue of adults.     

Choledochal cyst: a review of 19 cases

Nineteen cases of choledochal cyst are reviewed. Two distinct groups of patients were identified. Patients under one year of age, initially diagnosed as having biliary atresia, had a higher mortality rate, a higher incidence of severe cirrhosis with portal hypertension, and associated atresia or stenosis in the biliary tree. The second group, presenting between 3 and 20 years of age with more classic symptoms, had mild cirrhosis without portal hypertension and had associated choledocholithiasis and pancreatitis. It is suggested that the younger patients had a congenital form of cystic bile duct dilatation and that the older patients had an acquired form, perhaps related to a common channel with reflux of pancreatic juice into the common bile duct. Postoperative follow-up supports the current view that choledochocyst-jejunostomy with choleystectomy has a lower rate of long-term complications than does choledochocyst-duodenostomy.     

A method for defining competency in Pediatrics

In 1972 the American Board of Pediatrics (ABP) initiated studies leading to a report which identifies the important components of competency needed in the practice of pediatrics. The development of the report involved a group process engaging ABP board members and examiners. The outcome has been (a) the delineation of a process for establishing definitions of competency in a medical discipline; (b) the development of a framework for specifying the abilities needed to perform the tasks required of pediatricians; (c) an elaboration of samples of pediatric subjects to which these abilities and tasks are relevant; and (d) the development of a basis for choice of methods to use for purposes of certification.     

Laryngeal papillomatosis: immunologic and viral basis for therapy

The distressing nature of laryngeal papillomatosis and lack of clinical progress in its treatment are reviewed. Presently accepted and investigative methods of therapy are reviewed with special attention being given to immune therapy. Support for the concept of a viral etiology is discussed and other etiologic agents considered. Known and possibly significant roles of wart virus antibodies are discussed and the importance of complex interplay between maternal and fetal immune systems explored as a possible explanation for some puzzling aspects of laryngeal papillomatosis. Finally, a proposed experimental design is outlined, the purpose of which is to provide a useful animal model to investigate immune changes in laryngeal papillomatosis, as well as effects of surgical or medical therapy.     

The effects of coronary vasodilatation on cardiac performance during endotoxin shock

Results of studies have suggested that endotoxin and lowered coronary arterial perfusion pressures are detrimental to cardiac performance and lead to failure. Prevention of cardiac failure in the isolated canine heart preparation confronted with endotoxin and decreased coronary perfusion pressure was possible by perfusing these hearts with sodium nitroprusside. Prevention of failure was manifested by a lowered left ventricular endiastolic pressure and was associated with increased coronary flow and decreased coronary resistance with increased oxygen delivery and decreased oxygen extraction. Possible explanations for improved performance by dilator perfusion include increased delivery of oxygen and nutrients to myocardial tissue as well as a reduction of ventricular wall tension by dilating the coronary vascular skeleton. Prevention of extravasation of interstitial fluid into myocardial tissue by reducing overperfusion of potentially damaged coronary vessels could serve to maintain myocardial integrity and ventricular compliance. The potential use of such therapy warrants further study, with emphasis on evaluating the hemodynamics of the intact animal.     

Evaluation of the effects of presentation rate and speaking rate on children's auditory perception of two levels of linguistic material

Twenty-four first- and second-order sentential approximations of four words each were presented auditorily to two groups of eight normal children. Eight first- and eight second-order approximations were spoken at three rates: 90 (slow); 140 (normal); and 175 (fast) words/min. The 48 approximations were randomized and rates altered as necessary so that one group heard the material at a slow rate (90 words/min) of presentation and the other group at a normal rate (140 words/min) of presentation. The results indicated that although presentation rate did not significantly effect auditory perception, speaking rate did. It was concluded that a slow speaking rate can be expected to enhance the perception of low-level linguistic material regardless of the presentation rate, whereas a normal speaking rate would be best for higher level linguistic material.