No abstract

1.The percentage of human plasma tryptophan in the free state (ultrafilterable) was positively and significantly correlated with plasma non-esterified fatty acid (NEFA) concentration.2. Results obtained either by adding tryptophan to plasma in vitro or from plasma taken during tryptophan infusion indicate one tryptophan binding site per albumin molecule and an inverse relationship between binding constants and NEFA concentration.3. A single normal subject was atypical as the apparent number of binding sites varied between one and two per albumin molecule (1.54rt0.49 SD, four experiments).4. Spontaneous increases of plasma NEFA during tryptophan infusion were associated with increased free tryptophan. Also addition in uitro of linoleic acid, oleic acid and palmitic acid to plasma caused free tryptophan to increase. 5. The possible significance of NEFA changes on plasma tryptophan binding in various pathological circumstances is discussed.

The effects of intravenous infusion of L‐tryptophan at doses of 75 and 100 mg/kg were compared with that of normal saline in healthy volunteers by means of a series of psychological and physiological measures. The 100 mg/kg infusion produced a 40 fold increase in free tryptophan and an 8 fold increase in the bound form. Few of the objective tests showed any differences. The electroencephalogram showed a significant increase in slow‐wave activity (4.0 to 7.5 Hz) and a trend toward decreased fast‐wave activity (13.5 to 26.0 Hz). Some impairment of a motor speed task was also noted. Reduction of arousal and increased drowsiness (but no euphoria) were shown by the subjective ratings.

1 The metabolism of a standard oral dose of levodopa was studied in forty-two patients with Parkinsonism. Plasma levodopa and 3-o-methyldopa concentrations were estimated at intervals for 8 h after ingestion and the concentration of homovanillic acid (HVA) in the lumbar cerebrospinal fluid (CSF) was measured at 8 hours. Clinical responses 3 months after the test were compared with these findings. 2 Although therapeutic benefit correlated significantly with calculated estimates of both plasma levodopa concentration and CSF HVA at optimal levodopa dose, individual values were widely scattered. There was no significant correlation between toxic effects and plasma levodopa or CSF HVA; and 3-o-methyldopa concentrations similarly did not show a significant correlation with either toxic or therapeutic effects. 3 Blood and CSF levels of levodopa or the metabolites measured in this study were not significantly altered by concurrent treatment with either anticholinergic drugs or amantadine nor by previous treatment with levodopa.

The ability of the newborn kidney to reabsorp filtered bicarbonate seems to be limited when compared to that of the adult kidney. This may be due to renal or extrarenal factors which are still ill-defined. Bicarbonate handling during acute acid-base changes was studied in newborn rabbits before the end of nephrogenesis. Fourty anesthetized mechanically-ventilated rabbits aged 5-12 days were studied during hypercapnic acidosis, metabolic acidosis or metabolic alkalosis. Inulin was used as a marker of glomerular filtration rate. Control newborn rabbits were in a state of hypochloremic metabolic alkalosis (blood pH 7.49, HCO, 31 mmol/l, CI 83 mmol/l) which was not present in adult rabbits (pH 7.41, HCO, 19.5, CI 100 Various enzymes of which the deficiency causes a type of glycogenoses have been investigated in 20 control samplings of chorionic villi (CVS) between 8 and 12 weeks of gestation. Except glucose 6-phosphatase which is either not expressed or not yet developed, the activity of seven enzymes were well measurable in cvs. The glycogen content was 0.2-0.8 g per 100 g CVS; the activity of 1 ,4-~-glucosidase (4G), 3.0-16.0 nmol/min/mg protein (U); amyloglucosidase (6G), 0.12-0.56 U; brancher, 0.40-0.95 U; phosphorylase (PL), 0.2-1.5 U (a form) or 3.0-15.0 U (total); phosphorylase kinase (PK), 1.3-7.0~mol/min/mg protein; phosphofructokinase (PF), 1.8-8.5 U; glycogen synthase, 0.1-0.3 U (I-form) or 0.4 -3.0 U (D-form). Prenatal diagnosis of M.Pompe was performed in a pregnancy at risk by chorionic biopsy at the 8th week as well as by amnioscentesis at the 17th week. The 4G activity in CVS and in amniotic cells was in the range of heterozygotes, as was in leucocytes of cord blood at birth. Glyocgenosis type III can also' be diagnosed prenatally by direct assay of 6G in CVS. Investigation of PL, PK and PF was done by isoelectrofocusing and kinetic studies in order to explore diagnostic ways of severe forms of respective deficiencies. Three variants of phosphorylase kinase (PK) deficiency have been described, differing from one another by their genetic mode of inheritance and their organ involvement. The present report describes two additional variants for GSD IX: The first, in which the PK deficiency was reduced in muscle only (activity was 0.3 as compared to 2.6±1.5 U phosphorylase a/mg prot/min), with no indication of liver,erythrocyte or leukocyte involvement. The second variant presented in a 2-year-old boy with hepatomegaly and a slight tendency to fasting hypoglycemia. Blood cell PK activities were measured and are summarised in the Spontaneously breathing pre term infants 48 h old, of 32 weeks gestation or less, were assigned randomly to receive caffeine citrate (loading dose 20 mg/kg,' maintenance dose 10 mg/kg/day) or placebo (NaCI 0.9%). To demonstrate a reduction from 50% to 25% in the proportion of infants with >6 hypoxaemias (decrease in tcPo, of 20% within 20 sec)/12 h required a sample size of 25 per group (50% power, 5% type I error). tcPo, was recorded continuously for 50 hand analised by computer....