Unusual swimming mechanism in Calycopsis borchgrevinki (Hydrozoa)

Calycopsis borchgrevinki (Browne, 1910) from Antarctic waterswas studied histologically. The entire bell is enclosed in achitin-like skin, supported by chitin-like rods in the radialmesogleal fibres. In the tentacles a thick mesogloea is presentwithout chitinous structures. The gonads are embedded in thestomach folds. It is postulated that these characters are adaptationsto ecological conditions in Antarctic waters.     

Peptides and multiple antigen peptides from Schistosoma mansoni glyceraldehyde 3-phosphate dehydrogenase: preparation, immunogenicity and immunoprotective capacity in C57BL/6 mice.

Four monoepitopic MAPs (MAP A, B, C and E) and one bis-diepitopic MAP B-E derived fromthe primary sequence of Schistosoma mansoni glyceraldehyde 3-phosphate dehydrogenase, previously tested in BALB/c mice, were examined for their immunogenicity and protective capacity in C57BL/6 mice. Despite multimerization into MAPs, MAP Aand MAP C were poorly immunogenic. In contrast toBALB/c mice, MAP E was non-immunogenic in C57BL/6 mice. Peptide B in the form of MAP B orbis-diepitopic MAPB-E elicited immune responses in C57BL/6 mice that were associated with a significant decrease in worm burden. The MAPs were prepared by the stepwise solid-phase peptide synthesis using Boc/Bzl chemistry, successfully purified on the RP-HPLC column and characterized by RP-HPLC, HPCE and MALDI-TOF MS techniques. A general strategy for MAPs purification is discussed here and the purification of MAP Band MAP E is documented in detail.     

Comparative radionuclide and thermodilution determinations of cardiac output and stroke volume in the baboon (Papio ursinus)

Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy were performed in ten healthy chacma baboons (Papio ursinus). The correlation was moderately good between both the radionuclide and thermodilution stroke volume (r = 0.58, SEE = 3 ml; SVth = 0.78SVr + 15.6 ml) as well as the cardiac output (r = 0.72, SEE = 0.2 liter/min; COth = 0.56 Cor + 2.1 liter/min). The attenuation depth dr as determined by radionuclide techniques was found to correlate well with the radiologically determined values dx (r = 0.8, SEE = 0.4 cm; dx = 0.87dr + 0.72 cm) which validated the depth values used in the calculations.     

Transformation of sensory organs by mutations of the cut locus of D. melanogaster

The identities of two types of sensory organs in the body wall of Drosophila, namely the external sensory organs and the chordotonal organs, are under genetic control. Embryonic lethal mutations in the cut gene complex transform the external sensory organs into chordotonal organs. The neurons, as well as the support cells forming the external sensory structures, change their morphological and antigenic characteristics to those of chordotonal organs, providing genetic evidence that these two types of sensory organs are homologous. Similar transformations of external sensory organs are observed in adult mosaic flies. Analysis of mosaic larvae and flies suggests that the cut gene function is required either in or near external sensory organs in order for them to acquire their correct identity.     

The role of bacterial cell wall hydrophobicity in adhesion

In this study, the adhesion of bacteria differing in surface hydrophobicity was investigated. Cell wall hydrophobicity was measured as the contact angle of water on a bacterial layer collected on a microfilter. The contact angles ranged from 15 to 70 degrees. This method was compared with procedures based upon adhesion to hexadecane and with the partition of cells in a polyethylene glycol-dextran two-phase system. The results obtained with these three methods agreed reasonably well. The adhesion of 16 bacterial strains was measured on sulfated polystyrene as the solid phase. These experiments showed that hydrophobic cells adhered to a greater extent than hydrophilic cells. The extent of adhesion correlated well with the measured contact angles (linear regression coefficient, 0.8).     

Reductive dechlorination of 2,4-dichlorobenzoate to 4-chlorobenzoate and hydrolytic dehalogenation of 4-chloro-, 4-bromo-, and 4-iodobenzoate by Alcaligenes denitrificans NTB-1

Alcaligenes denitrificans NTB-1, previously isolated on 4-chlorobenzoate, also utilized 4-bromo-, 4-iodo-, and 2,4-dichlorobenzoate but not 4-fluorobenzoate as a sole carbon and energy source. During growth, stoichiometric amounts of halide were released. Experiments with whole cells and cell extracts revealed that 4-bromo- and 4-iodobenzoate were metabolized like 4-chlorobenzoate, involving an initial hydrolytic dehalogenation yielding 4-hydroxybenzoate, which in turn was hydroxylated to 3,4-dihydroxybenzoate. The initial step in the metabolism of 2,4-dichlorobenzoate was catalyzed by a novel type of reaction for aerobic organisms, involving inducible reductive dechlorination to 4-chlorobenzoate. Under conditions of low and controlled oxygen concentrations, A. denitrificans NTB-1 converted all 4-halobenzoates and 2,4-dichlorobenzoate almost quantitatively to 4-hydroxybenzoate.     

Plasmids in Leuconostoc oenos

A new procedure was used to isolate 11 plasmids from eight Leuconostoc oenos strains. Plasmid DNA was not detected in 34 other strains of this species. Plasmid sizes ranged from 2.47 to 4.61 kilobase pairs. This is the first report of extrachromosomal elements in L. oenos.     

The oxidation product of molybdenum cofactor from milk xanthine oxidase

In extracts of acid treated molybdenum cofactor containing xanthine oxidase, fluorescence is maximally developed upon a three hours incubation. Analysis by means of reversed phase HPLC revealed the presence of several fluorescent compounds, the main one being a blue fluorescent compound with an emission maximum of 465 nm when maximal excited at 395 nm at a neutral pH. Definite proof is presented that this compound is the oxidation product of the molybdenum cofactor. The remaining fluorescent products are shown to be pterin-derivatives, yielding predominantly pterin-6-carboxylic acid upon permanganate oxidation. Purified oxidation product of molybdenum cofactor however, didn's yield a fluorescent derivative at all upon treatment with permanganate.