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.     

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.     

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.     

Morphology and ultrastructure of the antennal chemoreceptors and mechanoreceptors of worker Coptotermes formosanus Shiraki

Data on respiratory symptoms and smoking for 2749 white American high school students from two linked surveys, separated by a one year lapse, are presented. There was a significantly higher likelihood of smoking at second survey among those who had initial symptoms. (There had been no educational efforts linking smoking and respiratory symptoms in the interim.) This difference was almost entirely contributed by those who had been ex-smokers and light (less than or equal to four cigarettes/day) smokers at first survey. Initial ex-smokers and light smokers also had, overall, least fixed smoking habits. Whatever the initial smoking or symptom status, symptoms at second survey were far more likely with current smoking. Controlling for initial symptom and smoking status, the gradient of symptoms between current smokers and non-smokers was over two and a half fold, except among those who had had symptoms and had not been smoking, and whose initial symptoms presumably arose from causes other than current cigarette smoking. Even among that group, symptoms at second survey were half as likely again among those who reported having become smokers (p less than-001). There were also strong linear trends of increased likelihood of symptoms with increased numbers of cigarettes smoked. Symptom rates at second survey of those who had symptoms a year earlier, and who stopped smoking during the year, were not as low as for those who also stopped smoking, but who had not had initial symptoms, suggesting that symptoms associated with smoking were not completely reversible in the time interval of this study. The difference, however, was not significant.     

Women's attitudes to mastectomy for breast cancer

One hundred patients who had been subjected to mastectomy for carcinoma were interviewed retrospectively to gauge their attitudes to any physical and/or emotional disabilities relating to their operation or disease. It was found that 40% of the patients had delayed for longer than a month after the onset of symptoms before seeking medical advice, but the reasons for this were not readily forthcoming. However, fear of mastectomy was not a common cause. Anxiety and embarassment due to an absent breast occurred in about one-third of patients, and did not diminish with time. Knowledge and the use of mammary prostheses was far from universal, and disturbingly only two-thirds were counselled in these matters by their medical advisers. Physical complications were common, particularly lymphoedema of the arm, and as expected this was closely related to the type and extent of treatment undertaken.