Diagnosis of Hunter's syndrome carriers; Radioactive sulphate incorporation into fibroblasts in the presence of fructose 1-phosphate

Summary Mutual correction of co-cultivated fibroblasts from patients with Hunter's and Hurler's syndrome could be inhibited by either fructose 1-phosphate or mannose 6-phosphate. In the presence of fructose 1-phosphate a 50% mixture of fibroblasts from a patient with Hunter's syndrome and a normal homozygous individual showed an increased³⁵S-sulphate incorporation into acid mucopolysaccharides. When fibroblast cultures from one obligate and two possible carriers of Hunter's syndrome were tested for³⁵S-sulphate incorporation, the cultures showed either twice the normal³⁵S-sulphate incorporation into acid mucopolysaccharides in the presence of fructose 1-phosphate or an abnormally high incorporation in the presence as well as in the absence of the sugar phosphate.     

Phenylalanine 4-monooxygenase from bovine and rat liver: Some physical and chemical properties

Phenylalanine 4-monooxygenase was purified from bovine liver using a modification of the procedure developed for the rat liver enzyme (Shiman, R., Gray, D. W., and Pater, A. 1979. J. Biol. Chem. 254:11300–11306). The enzyme preparation appeared essentially homogeneous on polyacrylamide gel electrophoresis under non-denaturing conditions. Electrophoresis in the presence of dodecyl sulfate revealed that about 95% of the protein had a mobility, corresponding to M_r=51,000. The remaining 5% was recovered in two minor bands corresponding to M_r of about 35,000 and 15,000 and is likely to result from limited proteolysis of the native enzyme with dissociation of the fragments on denaturation by detergent. The enzyme comigrated with the rat liver enzyme on polyacrylamide gel electrophoresis in both systems studied. No significant difference was observed between the amino acid composition of the bovine and rat liver enzyme, in the reactivity of their sulfhydryl groups or in their iron content (i.e. 1.5–3.0 iron atoms per peptide chain of M_r=50,000). Both enzymes contained less than 0.01 copper atom per peptide chain. The enzymes were inhibited in a similar manner by the chelator bathophenanthroline disulfonate (selective for iron and copper), but not by bathocuproine disulfonate (specific for copper). The results indicate that the bovine and rat liver enzymes are closely similar and that iron, but not copper, is essential for enzyme activity. High performance size-exclusion liquid chromatography revealed that both native enzymes exist in different oligomeric forms, but further studies are required to understand the physicochemical basis for this phenomenon.Abbreviations Bathophenanthroline 4,7-diphenyl-1, 10-phenanthroline - bathocuproine 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline - Hepes N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid - dansyl 1-dimethylaminonaphthalene-5-sulfonyl - DMPH₄ 2-amino-4-hydroxy-6,7-dimethyl-5,6,7,8-tetrahydropteridine - M_r relative molecular mass     

Plasma and Tissue Levels of Trimethoprim in The Rainbow Trout,Salmo Gairdneri,After Absorption From Fresh and Salt Water

This is a comparative study of uptake of trimethoprim from 1) fresh water, 2) salt water after 7 days of adaption and 3) salt water without previous adaptation. The rate and extent of absorption were found to vary significantly. The salt water adapted group reached a plasma concentration of approx. 1 µg/ml after 10 h, the unadapted salt water group after 24 to 48 h and the fresh water group did not reach this concentration. The results are discussed in relation to the non-ionic diffusion theory and to the alterations taking place in euryhaline species of fish during adaptation to salt water.     

Total Thyroxine and Free Thyroxine Index in Plasma of Dairy Cows in Relation To Strength of Heat

Total thyroxine (TT4) and free thyroxine index (FT4I) were measured in peripheral plasma of cows. The samples were collected at the time of insemination from 66 cows showing pronounced signs of the heat and from 56 cows showing weak or silent heat. Neither TT4 or FT4I in plasma differed significantly between the two categories of oestrous cows.     

Abiotic formation of particles from extracellular organic carbon released by phytoplankton

¹⁴C-labeled extracellular organic carbon (EOC) released by the phytoplankton in a Danish Estuary was shown immediately to form particles (>0.2m) when the products were added to a natural water sample. About 14%–20% of the added activity could be recovered as particles. Any bacterial assimilation of the extracellular products was thus masked. The abiotic origin of the particulate EOC was verified, and it was shown that the particle formation was due to some factors present in the estuarine water with a nominal diameter >0.2m. Precaution must be taken to avoid misinterpretations in studies concerning carbon flow from algae to bacteria.     

Anti-immunoglobulin-induced potassium flux in relation to capping and DNA synthesis : An analysis in monoclonal human B lymphoma cell populations

F(ab′)₂ anti-μ, as well as anti-δ and anti-γ heavy chains have been found to induce strong increases in the influx of ⁸⁶Rb⁺ (a potassium analogue) in cell suspensions from a proportion of human lymphomas staining monoclonally for B cells. The specificity of the response corresponded to the surface immunoglobulin (sIg) isotype present on lymphoma cells. Even when carried out under closely analogous conditions, no relationship between capping and ⁸⁶Rb⁺ influx was observed. On the other hand, an association between ⁸⁶Rb⁺ influx and mitogenic response to anti-immunoglobulin (anti-Ig) was observed with concordant results in 19 out of 21 comparisons made. These findings suggest that ⁸⁶Rb⁺ influx, which appears to be associated with mitogenic signals, and capping may arise as independent phenomena even when elicited through the same membrane receptor (sIg).     

Influence of clay minerals on sorption of bacteriolytic enzymes

Myxobacteria presumably produce extracellular bacteriolytic enzymes when they are growing in soil. In order to study their ecological significance, adsorption experiments were performed with lytic enzymes produced byMyxococcus virescens in casitone media. Different soils as well as montmorillonite and kaolinite can rapidly adsorb the bacteriolytic but not the proteolytic enzymes. About 1 gm of montmorillonite per liter of cell-free culture solution is enough for the adsorption of 97% of the bacteriolytic enzymes. The adsorption per unit weight is about 100 times greater on montmorillonite than on kaolinite. About 40% of the adsorbed enzymes can be eluted with solutions of high pH or high ionic strength. The only desorbed bacteriolytic enzyme is the alanyl-∈-N-lysine endopeptidase.