Sex hormone changes induced by the parasite lead to feminization of the male host in murine Taenia crassiceps cysticercosis

Female mice are more susceptible to Taenia crassiceps (TC) infection than males. However, after a month parasite load increases massively in both genders reaching thousands of parasites per host. The possibility of hormonal changes in the infected mice was envisaged. Sex hormones levels were assayed after different periods of infection, the parasites present in the peritoneal cavity were collected and gonads, uterus and seminal vesicles were weighed. In male mice, serum estradiol increased to levels 200 times their normal values whilst those of testosterone decreased 90% relative to controls. The weight of seminal vesicles was significantly diminished. Infected female mice also showed a slight increase in estrogen blood levels after 8 weeks of infection and the weight of the uterus was significantly increased relative to controls. Serum estradiol and testosterone were almost undetectable after gonadectomy. Cytokines such as IL-6 are capable of stimulating aromatase activity and we found that splenocytes from infected mice produced amounts of IL-6 higher than control as measured by ELISA. In conclusion T. crassiceps infection triggers a feminization process in the infected hosts. The gonads are required for the parasite to induce higher estrogen synthesis. IL-6 could be involved in the immunoendocrine mechanism used by the parasite to maintain a highly permissive environment for its rapid growth.     

Cellulase production by Rhizobium

Summary The production of cellulase byRhizobium species was studied.Rhizobium trifolii cellulase was induced by a variety of polysaccharides, including celluloses and hemicelluloses. Cellobiose and myo-inositol also allowed enzyme expression but mannitol prevented it at concentrations higher than 0.25%. Both soluble and insoluble plant root substances moderately stimulated cellulase production byRhizobium trifolii.Most substances tested did not induce the production of cellulases by the slow-growing, cowpea type rhizobia strain CIAT 79. Effective inducers were carboxymethylcellulose, gluconate and myo-inositol.Cellulase production was very low under all conditions tested. In most cases the enzyme activity was loosely bound to the capsular material. The enzyme in fast-growers is an 1,4--D-glucan-4-glucanohydrolase (endo-glucanase EC 3.2.1.4) with specificity for high molecular weight polysaccharides.There was no correlation between infectiveness ofRhizobium trifolii strains and cellulase production. One strain, which lacks the nodulation plasmid, produced cellulase at the same rate as its parental infective strain.     

Vanadate inhibition of the Ca-ATPase from human red cell membranes

1. (1) VO₃⁻ combines with high affinity to the Ca²⁺-ATPase and fully inhibits Ca²⁺-ATPase and Ca²⁺-phosphatase activities. Inhibition is associated with a parallel decrease in the steady-state level of the Ca²⁺-dependent phosphoenzyme.

2. (2) VO₃⁻ blocks hydrolysis of ATP at the catalytic site. The sites for VO₃⁻ also exhibit negative interactions in affinity with the regulatory sites for ATP of the Ca²⁺-ATPase.

3. (3) The sites for VO₃⁻ show positive interactions in affinity with sites for Mg²⁺ and K⁺. This accounts for the dependence on Mg²⁺ and K⁺ of the inhibition by VO₃⁻. Although, with less effectiveness, Na⁺ substitutes for K⁺ whereas Li⁺ does not. The apparent affinities for Mg²⁺ and K⁺ for inhibition by VO₃⁻ seem to be less than those for activation of the Ca²⁺-ATPase.

4. (4) Inhibition by VO₃⁻ is independent of Ca²⁺ at concentrations up to 50 μM. Higher concentrations of Ca²⁺ lead to a progressive release of the inhibitory effect of VO₃⁻.

New form of adrenoleukodystrophy

Summary Male and female siblings demonstrated similar facial features and had seizures from birth. Neurologic development, which was delayed, began to deteriorate at 1 year. Sudden death occurred at 2 8/12 and 2 3/12 years of age associated with respiratory infections. Tanning of the skin was noted 2 months before death in the first child. In the second child, blood cortisol levels failed to increase after intravenous ACTH administration, and computerized axial tomography (CAT) scans were normal.At autopsy both patients demonstrated adrenal atrophy and degenerative changes of the white matter throughout the neuraxis. We propose that these siblings have a new form of adrenoleukodystrophy that can be distinguished from the X-linked form by onset at birth, clinical appearance, and pattern of inheritance.A comparison of these cases with a second disorder, Zellweger's syndrome, suggests that a distinctive phenotype is associated with intrauterine degeneration of white matter.     

A major substrate of maturation promoting factor identified as elongation factor 1 beta gamma delta in Xenopus laevis

Protein synthesis is believed to be under control of the cell cycle during meiosis and mitosis. Any relationship between substrates for cdc2 kinase and components of the protein synthetic apparatus would therefore be of prime importance. During meiosis of Xenopus laevis oocytes one of the substrates for this kinase is a p47 protein, which is complexed to two other proteins, P36 and P30. Judged from partial amino acid sequence data on P47 and P30, the P30 and P47 proteins were reported to resemble the protein synthetic elongation factors (EF) 1 beta and 1 gamma from Artemia salina (Bellé, R., Derancourt, J., Poulhe, R., Capony, J.P., Ozon, R., and Mulner-Lorillon, O. (1989) FEBS Lett. 255, 101-104). This paper shows that the complex composed of P30, P47, and P36 from Xenopus is identical to the complex of EF-1 beta, EF-1 gamma, and EF-1 delta from Artemia according to two criteria. 1) Both stimulate elongation factor 1 alpha-mediated transfer RNA binding to ribosomes and exchange of guanine nucleotides on elongation factor 1 alpha to a comparable degree. 2) Each of the three subunits of the protein complex P30.P47.P36 from Xenopus shows a structural homology with one of the corresponding subunits of EF-1 beta gamma delta from Artemia. Presumably the phosphorylation of EF-1 gamma, which associates with tubulin at least in vitro, is important in processes following the onset of meiosis which is accompanied by a rise of protein synthesis.     

The influence of ionic composition on the distribution of nematode species in springs of the province of Granada (Spain)

The ionic composition of 38 mineral springs in the province of Granada (Spain), and the distribution of 45 species of nematodes belonging to orders Monhysterida, Araeolaimida, Chromadorida and Enoplida were examined. Water chemistry is used to make two diagrams representing anionic and cationic composition. Diagrams for anionic composition (given the greater variance seen in the springs considered) are used to illustrate the distribution of individual species. The results obtained from species distribution and the correlation between species made it possible to group species which could be associated with springs where each of the anions considered predominated. A greater number of species groups was found to inhabit springs in which chloride concentrations was less than 50% of the total concentration of anions.     

Structure-activity relationships for unsaturated dialdehydes. 6. The mutagenic activity of 11 compounds in the V79/HGPRT assay.

The mutagenic activity of 11 sesquiterpenoid unsaturated dialdehydes in the V79/HGPRT assay has been determined, and is compared with previously published data on the mutagenicity of the same compounds towards Ames Salmonella strains. One compound, isovelleral, is a potent mutagen in both assays, while six compounds, which are positive in the Ames Salmonella/microsome assay, show no significant activity in this study. One compound, acetylmerulidial, is negative in the Ames Salmonella/microsome assay but significantly although weakly mutagenic in the V79/HGPRT assay. The remaining three compounds are inactive in both assays. The study is part of a general investigation of quantitative structure-activity relationships for unsaturated dialdehydes, a class of natural occurring compounds known for their potent and numerous biological activities.     

Evaluation in Drosophila melanogaster of the mutagenic potential of furfural in the mei-9a test for chromosome loss in germ-line cells and the wing spot test for mutational activity in somatic cells.

The mutagenic potential of furfural was evaluated by means of the chromosome loss test in germ cells and the wing spot test in somatic cells of Drosophila melanogaster. The chromosome loss test was carried out employing repair-proficient as well as repair-deficient females. Males carried the compound Y chromosome, BSYy+. Two routes of administration were used: injection and feeding of adult males. Genetic damage was demonstrable after matings of treated males with females carrying the excision repair-deficient mutant mei-9a. The somatic mutation and recombination test was carried out treating 72-h transheterozygous mwh+/+flr3 larvae. Acute treatment of larvae was chosen as the method of exposure. Evidence indicates that furfural induces somatic damage as measured in the wing spot test.     

Cloning and expression of hepatitis B surface antigen in the yeastKluyveromyces lactis

Summary The gene coding for the major surface antigen of the hepatitis B virus was integrated into the genome ofKluyveromyces lactis and expressed up to levels of 0.4% of the total soluble protein.