Rate of 59Fe Uptake into Brain and Cerebrospinal Fluid and the Influence Thereon of Antibodies Against the Transferrin Receptor

Abstract: Uptake of ⁵⁹Fe from blood into brains of anaesthetized rats and mice has been studied by intravenous infusion of [⁵⁹Fe]ferrous ascorbate or of ⁵⁹Fe-transferrin, the results not being significantly different. Uptakes in the rat were linear with time, but increased at longer times in the mouse. Transfer constants, K _in (in ml/g/h × 10³), for cerebral hemispheres were 5.2 in the adult rat and 5.6 in the mouse. These K _in values corresponded to ⁵⁹Fe influxes of 145 and 322 pmol/g/h, respectively. ⁵⁹Fe uptake into the mouse brain occurred in the following order: cerebellum > brainstem > frontal cerebral cortex > parietal cortex > occipital cortex > hippocampus > caudate nucleus. In genetically hypotransferrinaemic mice, ⁵⁹Fe uptake into brain was 80–95 times greater than in To strain mice. Pretreatment of young rats and mice with monoclonal antibodies to transferrin receptors, i.e., the anti-rat immunoglobulin G OX 26 and the anti-mouse immunoglobulin M RI7 208, inhibited ⁵⁹Fe uptake into spleen by 94% and 98%, respectively, indicating saturation of receptors. The antibodies reduced ⁵⁹Fe uptake into rat brain by 35–60% and that into mouse brain by 65–85%. Although a major portion of iron transport across the blood-brain barrier is normally transferrin-mediated, non-transferrin-bound iron readily crosses it at low serum transferrin levels.     

Cytomorphology of induced octoploid Chili pepper (Capsicum annuum L.)

Summary Octoploidy was induced in Chili pepper (Capsicum annuum cultivar cerasiformis) through the application of colchicine and the cytomorphological features of two octoploid plants were described. In general, the octoploids did not exhibit gigas characters when compared to the tetraploids; on the contrary they were less vigorous, suggesting that the optimum and desirable ploidy level for Capsicum is probably tetraploid. Chromosome associations such as octovalents and hexavalents, in addition to IVs, IIIs, IIs and Is, were recorded at diakinesis and metaphase I. Meiosis was highly irregular and the pollen and seed fertility was very low. Cytological features of octoploid Chili peppers are compared with octoploids of Physalis and Petunia.     

Habituation to acid in Escherichia coli: conditions for habituation and its effects on plasmid transfer

Induction of acid resistance (habituation) in Escherichia coli at pH 5·0 took ca 5 min in broth at 37°C and 30–60 min in minimal medium. Induction occurred at a range of pH values from 4·0 to 6·0; it was dependent on continuing protein and RNA synthesis but substantial acid resistance appeared in the presence of nalidixic acid. Acid resistance was long-lasting; organisms grown at pH 5·0 retained most of their resistance after 2 h growth at pH 7·0. Organisms grown at pH 5·0 showed increased synthesis of a number of cytoplasmic proteins compared with the level in cells grown at pH 7·0. DNA repair-deficient strains carrying recA, uvrA or polAl mutations were more acid-sensitive than the repair-proficient parents but were able to habituate at pH 5·0. Organisms grown at pH 5·0 transferred the ColV plasmid much more effectively at acid pH than did those grown at pH 7·0 and habituated recipients appeared better able to repair incoming acid-damaged plasmid DNA than did those that were non-habituated. Induction of acid resistance at pH 5·0 may be significant for the survival of organisms exposed to periodic discharges of acid effluent in the aquatic environment and habituation may also allow plasmid transfer and repair of acid-damaged plasmid DNA during or after such exposure.     

Ant community composition and functional traits in new grassland strips within agricultural landscapes

1. Ongoing intensification and fragmentation of European agricultural landscapes dramatically reduce biodiversity and associated functions. Enhancing perennial noncrop areas holds great potential to support ecosystem services such as ant‐mediated pest control.
2. To study the potential of newly established grassland strips to enhance ant diversity and associated functions, we used hand collection data and predation experiments to investigate differences in (a) ant community composition and (b) biocontrol‐related functional traits, and (c) natural pest control across habitats in cereal fields, old grasslands, and new grassland transects of three years of age.
3. Ant species diversity was similar between new and old grasslands, but significantly higher in new grasslands than in surrounding cereal fields. Contrary, ant community composition of new grasslands was more similar to cereal fields and distinct from the species pool of old grasslands. The functional trait space covered by the ant communities showed the same distribution between old and new grasslands. Pest control did not differ significantly between habitat types and therefore could not be linked to the prevalence of functional ant traits related to biocontrol services in new grasslands.
4. Our findings not only show trends of convergence between old and new grasslands, but also indicate that enhancing ant diversity through new grasslands takes longer than three years to provide comparable biodiversity and functionality.
5. Synthesis and applications: Newly established grasslands can increase ant species richness and abundance and provide a consistent amount of biocontrol services in agroecosystems. However, three years after their establishment, new grasslands were still dominated by common agrobiont ant species and lacked habitat specialists present in old grasslands, which require a constant supply of food resources and long colony establishment times. New grasslands represent a promising measure for enhancing agricultural landscapes but must be preserved in the longer term to promote biodiversity and resilience of associated ecosystem services.

     

A Lagrangian Gamma Distribution of the Second Kind

The distribution of the time T for the occurrence of the rth event is derived in a linear function Poisson process, which belongs to a recently introduced family of distributions (JANARDAN and RAO, 1981), called Lagrangian distributions of the second kind (LD₂). In analogy with the ordinary Poisson process, the distribution of the random variable T has been termed the Lagrangian Gamma distribution of the second kind (LG₂); several of its properties and special cases are studied. The frequency function is graphed for some parameter values.     

Design and Synthesis of 1-Substituted-4-(4-Nitrophenyl)-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-ones as a New Class of Antihistaminic Agents

Russian Journal of Bioorganic Chemistry - Some new 1-substituted-4-(4-nitrophenyl)-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-ones were synthesized and screened for their H1-antihistaminic activity....     

Foliar Concentrations of Selected Elements,Assessment of Oxidative Stress Markers and Role of Antioxidant Defense System is Associated with Fly Ash Stress Tolerance in Withania somnifera

Journal of Plant Growth Regulation - Increased dependence on thermal power has resulted in a significant increase in the generation of fly ash (FA), which exacerbates environmental...     

Mice with dysfunctional TGF-β signaling develop altered intestinal microbiome and colorectal cancer resistant to 5FU

Emerging data show a rise in colorectal cancer (CRC) incidence in young men and women that is often chemoresistant. One potential risk factor is an alteration in the microbiome. Here, we investigated the role of TGF-β signaling on the intestinal microbiome and the efficacy of chemotherapy for CRC induced by azoxymethane and dextran sodium sulfate in mice. We used two genotypes of TGF-β-signaling-deficient mice (Smad4^+/? and Smad4^+/?Sptbn1^+/?), which developed CRC with similar phenotypes and had similar alterations in the intestinal microbiome. Using these mice, we evaluated the intestinal microbiome and determined the effect of dysfunctional TGF-β signaling on the response to the chemotherapeutic agent 5-Fluoro-uracil (5FU) after induction of CRC. Using shotgun metagenomic sequencing, we determined gut microbiota composition in mice with CRC and found reduced amounts of beneficial species of Bacteroides and Parabacteroides in the mutants compared to the wild-type (WT) mice. Furthermore, the mutant mice with CRC were resistant to 5FU. Whereas the abundances of E. boltae, B.dorei, Lachnoclostridium sp., and Mordavella sp. were significantly reduced in mice with CRC, these species only recovered to basal amounts after 5FU treatment in WT mice, suggesting that the alterations in the intestinal microbiome resulting from compromised TGF-β signaling impaired the response to 5FU. These findings could have implications for inhibiting the TGF-β pathway in the treatment of CRC or other cancers.