Treatment of acute otitis media: a controlled study of 142 children

Results of the use of ampicillin, penicillin G and symptomatic therapy in the treatment of acute otitis media in 142 children were compared. Antibiotic therapy conveyed significant benefit. No major differences were observed between penicillin and ampicillin, except in the age group under 3 years where ampicillin was associated with the best results. Ampicillin appears to be the drug of choice. Its superiority over symptomatic therapy was statistically significant. Long-term sequelae were not observed in any of the three treatment groups. The relative merits of erythromycin and ampicillin require further study.     

Amino acid sequences around the cystine residues in horse growth hormone

The cystine-containing peptides of horse growth hormone were isolated and their amino acid sequences determined. Four unique half-cystine residues occur in two peptides, one containing 11 and the other, at the C-terminus of the protein, 15 amino acids. These sequences are compared with published data on growth hormones from other species.     

Sites of synthesis of plasma proteins in the foetal rat

1. The foetal rat of 16 or more days incorporates ¹⁴C-labelled amino acids into all the demonstrable plasma protein fractions in vivo. 2. Slices of foetal rat liver incubated in vitro incorporate ¹⁴C-labelled amino acids into the main plasma protein fractions, including the foetal-specific `post-albumin'. 3. Slices of placenta are unable to incorporate ¹⁴C-labelled amino acids into plasma proteins in vitro. 4. Liver slices from maternal rats incubated in vitro incorporate ¹⁴C-labelled amino acids into plasma proteins. The presence of post-albumin cannot be demonstrated after incubation. 5. Liver slices from foetal rats, but not from adult rats, contain demonstrable amounts of haemoglobin into which ¹⁴C-labelled amino acids are incorporated.     

Inhibition of glucose phosphate isomerase by metabolic intermediates of fructose

1. Purified rabbit-muscle and -liver glucose phosphate isomerase, free of contaminating enzyme activities that could interfere with the assay procedures, were tested for inhibition by fructose, fructose 1-phosphate and fructose 1,6-diphosphate. 2. Fructose 1-phosphate and fructose 1,6-diphosphate are both competitive with fructose 6-phosphate in the enzymic reaction, the apparent K_i values being 1·37×10⁻³−1·67×10⁻³m for fructose 1-phosphate and 7·2×10⁻³−7·9×10⁻³m for fructose 1,6-diphosphate; fructose and inorganic phosphate were without effect. 3. The apparent K_m values for both liver and muscle enzymes at pH7·4 and 30° were 1·11×10⁻⁴−1·29×10⁻⁴m for fructose 6-phosphate, determined under the conditions in this paper. 4. In the reverse reaction, fructose, fructose 1-phosphate and fructose 1,6-diphosphate did not significantly inhibit the conversion of glucose 6-phosphate into fructose 6-phosphate. 5. The apparent K_m values for glucose 6-phosphate were in the range 5·6×10⁻⁴−8·5×10⁻⁴m. 6. The competitive inhibition of hepatic glucose phosphate isomerase by fructose 1-phosphate is discussed in relation to the mechanism of fructose-induced hypoglycaemia in hereditary fructose intolerance.