Glycinebetaine content of halophytes: Improved analysis by liquid chromatography and interpretations of results

The glycinebetaine content of plants can be determined by simple isocratic high performance liquid chromatography. The method is applicable to extracts from a wide range of species and, in most cases, is suitably rapid and specific to be preferable to other methods of analysis. The chromatographic system employed permits accurate and sensitive ultraviolet detection, free of most interferences. Because the principle plant carbohydrates elute well before glycine betaine, preparative ion exchange procedures can be simplified. Twenty-seven species, mostly inland halophytes, were screened by these methods and 13 were found to be glycinebetaine accumulators. On a dry weight basis, the glycinebetaine content of Salicornia europaea L. actually declined with exposure to progressively higher levels of NaCl. When expressed as a proportion of plant organic matter, however, patterns were more typical (up to 7.7% at higher salt concentrations).     

Alpha-melanotropin in the frog brain: regional distribution, quantification and subcellular distribution

The distribution of alpha-MSH containing neurons was studied by immunofluorescence in the brain of the frog Rana ridibunda. Most immunoreactive cell bodies were found in the ventral hypothalamic area. A rich network of fluorescent fibers was observed in the ventral infundibular region, coursing towards the preoptic area and the ventral telencephalon. Some fibers, directed backwards, project into median eminence. By means of a specific radioimmunoassay, the concentrations of alpha-MSH immunoreactive material has been determined in 10 different regions of the brain. The highest concentrations were observed in the infundibular and the preoptic regions. Using the immunogold technique, electron microscopy showed that immunostaining was restricted to 70-100 nm dense core vesicles in positive cell bodies and fibers. These results suggest that, in addition to well known hormonal (melanotropic) activity, alpha-MSH could play the role of a neurotransmitter in the frog brain.     

Structural investigation of the capsular polysaccharide produced by a novel Klebsiella serotype (SK1). Location of O-acetyl substituents using NMR and MS techniques

The capsular polysaccharide of Klebsiella SK1 was investigated by methylation analysis, Smith degradation, and ¹H NMR spectroscopy. The oligosaccharides (P1 and P2) obtained by bacteriophage ΦSK1 degradation of the polymer were studied by methylation analysis, and 1D- and 2D-NMR spectroscopy. The resulting data showed that the patent repeating unit is a branched pentasaccharide having a structure identical to the revised structure recently proposed for Klebsiella serotype K8 capsular polysaccharide.

The 2D-NMR data showed that one third of the glucuronic acid residues in the SK1 polymer are acetylated at O-2, O-3, or O-4. FABMS studies confirmed the presence of monoacetylated glucuronic acid residues. Thus, the relationship between the Klebsiella K8 and SK1 polymers is akin to that found for Klebsiella polysaccharides K30 and K33, which have been typed as serologically distinct yet their structures differ only in the degree of acetylation.     

A new procedure for the synthesis of polyethylene glycol-protein adducts; effects on function, receptor recognition, and clearance of superoxide dismutase, lactoferrin, and alpha 2-macroglobulin

A new, simplified technique for the synthesis of polyethylene glycol (PEG) derivatives of proteins utilizing 1,1'-carbonyldiimidazole for PEG activation, is described. PEG derivatives of superoxide dismutase, alpha 2-macroglobulin, alpha 2-macroglobulin-trypsin, and lactoferrin were prepared and studied. Superoxide dismutase coupled to PEG preserved 95% of its original activity while its plasma half-life increased from 3.5 min to 9 or more hours depending on the PEG derivative studied. PEG-derivatized alpha 2-macroglobulin showed decreased protease binding activity but PEG derivatives of performed alpha 2-macroglobulin-trypsin demonstrated no loss of activity. The plasma clearance of PEG-alpha 2-macroglobulin-trypsin was prolonged significantly compared to native alpha 2-macroglobulin-trypsin, particularly when a high-molecular-weight PEG was coupled to the protease inhibitor complex. The plasma clearance half-life of lactoferrin was increased 5- to 20-fold by this modification. Trinitrobenzenesulfonic acid titration studies demonstrated that epsilon-amino groups of lysine residues are modified by the coupling of carbonyldiimidazole-activated PEG to proteins.     

Le lymphosarcome folliculaire: La maladie de Brill-Symmers

From a survey of the literature on follicular lymphoma it appears that the lesion of Brill-Symmers disease may be considered to be a form of neoplasm. The authors have reviewed a series of 18 cases seen at the Hôtel-Dieu of Québec between 1950 and 1960 and have adopted Rappaport''s classification published in 1956, but leaving out the “Hodgkin” Type 5 which they propose to examine more fully in another paper.There appears to be a degree of positive correlation between the histologic type and the course of the disease, the well differentiated cell Type 1 being associated with a protracted course. This neoplasm should not be mistaken for benign follicular hyperplasia.     

Measurement by HPLC of Desferrioxamine-Available Iron in Rabbit Kidneys to Assess the Effect of Ischaemia on the Distribution of Iron Within the Total Pool

A method for the determination of desferrioxamine-available iron in tissue fractions is described which involves incubation with desferrioxamine, extraction of desferrioxamine and its iron-bound form, ferrioxamine, and quantitation of these two forms of the drug by reversed-phase hplc analysis. Chelatable iron levels in the 1-10µMolar region could be accurately and reproducibly measured using this technique.

The desferrioxamine-available iron levels in both the cortex and medulla of rabbit kidneys were significantly elevated (up to 2-fold) after the organs had been subjected to 2 hours warm ischaemia or 24 hours cold storage at 0°C In hypertonic citrate solution. There was no change in the total iron content of the tissues under these circumstances and thus a redistribution of intracellular iron to more available pools had presumably taken place as a result of ischaemia. This redistribution of iron may be an important factor in the initiation of peroxidative damage to cell membranes upon reperfusion of the organ with oxygen.     

Acquisition of a lysosomal enzyme by myoblasts in tissue culture

Skeletal muscle myoblasts from different sources acquired high levels of the lysosomal enzyme beta-glucuronidase, when they were cultured together with mitogen-activated lymphocytes. Immunofluorescent staining, thermal stability, and electrophoretic mobility showed that the increase in enzyme activity in the myoblasts was due to the presence of the lymphocyte form of the enzyme. Although myoblasts were able to take up exogenous beta-glucuronidase from the culture medium by mannose 6-phosphate receptor-mediated endocytosis, enzyme acquisition during co-culture with lymphocytes was independent of this pathway. Enzyme transfer from the lymphocytes was found to require direct cell-cell contact with the muscle cells, and was accompanied by an increase in beta-glucuronidase activity in the lymphocytes themselves. Since this additional activity was also due to the presence of the lymphocyte form of the enzyme, these results indicate that interaction with the muscle cells induced the de novo synthesis of beta-glucuronidase in the lymphocytes.     

Plasmid-mediated resistance to fosfomycin in Staphylococcus epidermidis

Staphylococcus epidermidis strain BM2641, isolated from a patient, was resistant to penicillin G, methicillin, aminoglycosides, chloramphenicol, macrolide, lincosamide and streptogramin B-type (MLS) antibiotics, and to high levels of fosmycin. Resistance to forsfomycin and/or to MLS was lost at low frequencies either spontaneously or after curing with novobiocin. The plasmid DNA from BM2641 and its cured derivatives was purified, analyzed by agarose gel electrophoresis and transferred to a nitrocellulose sheet. Comparative analysis of the resistance phenotypes with the plasmid content of the strains indicated that fosfomycin and MLS resistance were encoded by plasmids pIP1842 (2.5 kb) and pIP1843 (2.6 kb), respectively. Southern hybridization with a probe specific for gene fosA of Serratia marcescens showed that the fosfomycin resistance determinant in Staphylococcus is not homologous to that of Gram-negative bacteria.