Precocious development of glucuronidating and hydroxylating enzymes in chick embryos treated with pituitary grafts

1. Initiation of precocious development of UDP-glucuronyltransferase by an endogenous factor is reported for the first time. 2. This development occurs in chick embryo liver and kidney after grafting of the cephalic lobe of chicken pars-distalis pituitary tissue on to the chorioallantoic membrane, and in liver results in a rise in the enzyme activity from virtually zero to ;adult' values. Aniline hydroxylase also precociously develops in the liver of grafted embryos, its activity rising from one-third to the full adult value. Specific activities of glucose 6-phosphatase, cytochrome P-450 and NADPH-cytochrome c reductase did not significantly change. 3. The response of the transferase does not require the presence of host pituitary gland nor, apart from 1 day's necessary initiation, the presence of the graft itself. 4. The host becomes competent to respond on the 14th day of incubation; response continues for at least 3 days after removal of the graft, and for 2 days in the isolated liver. Grafting of embryonic pars distalis younger than 17 days does not evoke a response in the host liver. 5. Secretion of the pituitary factor increases suddenly some 24-48h before the naturally developing surge in liver UDP-glucuronyltransferase activity and may be responsible for initiating this rise in vivo. 6. The factor is probably not a growth or luteinizing hormone; its nature and the likelihood of a secondary hormone acting directly on the liver are discussed.     

Studies on Alternaria allergens. II. Measurement of the relative potency of commercial Alternaria extracts by the direct RAST and by RAST inhibition

We investigated 104 cases of infantile convulsions which occurred before two years of age. These cases had no detectable signs of acute brain disorders, and they had normal psychomotor development and normal EEG findings at onset. (1) Sex ratio was 1:1. (2) A positive family history of various types of convulsions was obtained in 30.8% (Febrile convulsion: 65.7%) (3) The incidence of perinatal anoxic brain damage was higher than that in the control group. This was probably related to the incidence of infantile convulsion. (4) More than half the cases (66.3%) had the first convulsion between three and eight months of age, and 95.6% of prospectively follow-up cases were shown free from attacks before two years of age. (5) Precipitating factors to convulsion were found in 45.1% of all cases. These factors were bathing and non-febrile infection. (6) The most common form of infantile convulsion is generalized tonic and/or clonic convulsion (78.8%) within 5 min. (82.7%). This convulsion reccurs frequently in a relatively short period. (7) The incidence of subsequent epilepsy seems to have been found among patients who had had an initial attack between three and five months of age, and had then experienced convulsion more than six times or in a prolonged state.     

Randomly branched styrene/divinylbenzene copolymers. II. Solution properties and structure

The [η] of randomly branched PSty/DVB continually decreases from linear polystyrene with increasing conversion. On the other hand, the relation of the 〈S²〉 to M of both low and high conversion series is equivalent, although the actual size is smaller than that of linear polystyrene of the same M. This fact, in conjunction with the previously published reactivity ratios, allows the following interpretation of the mechanism of copolymerization: namely, that branched molecules are formed in which the center core is higher in DVB content than is the periphery. Only about 1/7 of the available DVB units act as effective tetrafunctional branch points. An analysis of GPC data correlated with light scattering and viscosity dimensions allows the g value to be determined in the lightly and highly branched fractions. The viscosity ration is related to g^x, where x is 0.65 for low conversion fractions (A series) and becomes 1.41 for high conversion fractions (B series). This change in exponent is postulated to arise from an increase in branching density as conversion increases. The ratio of the hydrodynamic radius to the radius of gyration is higher for branched than for linear polymers. The theta temperature (θ) in cyclohexane for randomly branched polystyrene compared to linear polystyrene is always higher and can be as much as 2° higher.     

The metabolic clearance rates and interconversion of cortisol and cortisone in pregnant and nonpregnant baboons

Pregnancy alters the pattern of maternal cortisol (F) metabolism and increases the maternal serum cortisol-binding capacity (CBC) of baboons. To determine whether these changes are associated with alterations in F clearance,the metabolic clearance rate (MCR) and interconversion (p) of F and cortisone (E) were measured by continuous infusion of (3H)F and (14C)E in 9 regularly menstruating and 7 pregnant baboons (Papio papio). In nonpregnant animals, the values (X +/- SE) for MCR-E (488 +/- 48 1/day) were greater (P less than 0.001) than those for MCR-F (214 +/- 22 1/day). The p value for the conversion of E leads to F (62.8 +/- 4.7%) was greater (P less than 0.001) than that for the reaction F leads to E (41.6 +/- 3.7%), indicating that F formation is favored. Consistent with MCR-E greater than MCR-F, the per cent of F bound to proteins other than albumin (75 +/- 2) was greater (P less than 0.001) than the per cent of E bound (52 +/-3). The production rate (MCR x peripheral concentration; mug/min) of F (55.1 +/- 7.9) was greater (P less than 0.001) than that of E (28.5 +/-3.9) with essentially all of the F being secreted directly (secretion rate 51.2 +/- 7.9 mug/min). Essentially all of the E produced was derived from circulating F, vitually none being secreted directly (secretion rate 4.6 +/- 3.9 mug/min). Pregnancy did not alter the MCR-F (190 +/- 23 1/day), MCR-E 525+/- 51 1/day), per cent of F (79 +/- 3), or per cent of E (49 +/-3) bound,or F (57.2 +/- 9.2 mug/min) or E (35.5 +/- 4.9 mug/min) production rates. CBC (mug F/100 ml) was significantly (P less than 0.01) elevated (25.3 +/- 2.3, nonpregnant vs 35.1 +/- u.6, pregnant). In addition, p E leads to F was increased (75.5 +/- 1.8%) as was p F leads to E (54.3 +/- 3.7%; P less than 0.01). We have concluded that the MCR-F during pregnancy is more dependent on alterations in maternal metabolism than on the increased serum CBC characteristic of gestation. We suggest that the latter factor may be important in regulating the physiologic levels of the other steroids which bind to it.     

Isolation and partial characterization of a major basic protein from rat eosinophil granules

The rat eosinophil granule possesses a major basic protein (MBP) similar to that previously isolated from human and guinea pig eosinophils. This conclusion is based on demonstration that the major protein of the rat eosinophil granule is a low molecular weight, highly basic material with an amino acid composition similar to that of the human and guinea pig MBP.     

On the pathogenesis of Bartter's syndrome: report of studies in a patient with this disorder

A 25 year old male with features typical of Bartter's syndrome is described. Studies were performed to evaluate the pathogenesis of this disorder. In response to oral water loading the subject excreted free water normally. Normal renal sodium conservation was documented. Autonomy of the reninangiotensin-aldosterone system was excluded by demonstrating appropriate directional changes in plasma renin activity and aldosterone excretion in response to alterations in sodium and potassium intake. During aminoglutethimide inhibition of aldosterone synthesis the subject was able to maintain potassium balance at a normal serum potassium concentration on a potassium intake of 130 mEq/day which suggests that aldosterone is the major cause of the potassium wasting. Decreased vascular responses to intra-arterial infusions of angiotensin II and norepinephrine were documented in the absence of extracellular volume depletion. These findings argue against tachyphylaxis as the explanation for the vascular insensitivity and implicate a defect at some step in the sequence between agonist-receptor interaction and the contractile response. It is proposed that the vascular defect plays a primary role in the pathogenesis of the hyperreninemia by interrupting pressure-mediated inhibition of renin secretion and/or impairing direct feedback inhibition of renin secretion by angiotensin II. A unique finding in our case was the lack of a postural influence on plasma renin activity and plasma aldosterone. An accentuated plasma aldosterone circadian rhythm was observed independent of plasma renin activity and plasma potassium concentration. Dexamethasone suppression of ACTH reduced but did not abolish the circadian rhythm. Thus some factor in addition to plasma renin activity, potassium and ACTH appears to influence aldosterone secretion in this patient.