Design,synthesis and antimicrobial properties of non-hemolytic cationic α-cyclopeptoids

The synthesis and screening of neutral and cationic, linear and cyclic peptoids (N-alkylglycine peptidomimetics) is described. Structure–activity relationship studies show that the in vitro activities of the tested peptoids depend on both cyclization and decoration with cationic groups. The most powerful N-lysine cyclopeptoid derivatives showed good antifungal activity against Candida albicans (ATCC90029 and L21) and Candida famata (SA550, Amph B-resistant) and low hemolytic activity. The effects of the cyclic peptoids on membrane permeabilization were evaluated by the propidium iodide exclusion assay.     

Rootstock genotype succession influences apple replant disease and root-zone microbial community composition in an orchard soil

Apple replant disease (ARD) is a soil-borne disease complex that affects young apple trees in replanted orchards, resulting in stunted growth and reduced yields. Newly developed rootstock genotypes with tolerance to ARD may help to control this disease. We determined the effects of rootstock genotype rotations during orchard renovation, by investigating root-zone soil microbial consortia and the relative severity of ARD on seven rootstock genotypes (M.9, M.26, G.30, G.41, G.65, G.935, and CG.6210) planted in soil where trees on four of those same rootstocks (M.9, M.26, G.30 and CG.6210) had grown for the previous 15 years. Rootstock genotyping indicated that genetic distances among rootstocks were loosely correlated with their differential responses to ARD. Root-zone fungal and bacterial community composition, assessed by DNA fingerprinting (T-RFLP), differed between M.26 and CG.6210. Soil bacterial communities were influenced most by which rootstock had grown in the soil previously, while fungal communities were influenced more by the current replanted rootstock. In a clone library of bacteria from M.26 and CG.6210 root-zone soil, β-Proteobacteria was the most abundant phylum (25% of sequences). Sequences representing the Burkholderia cepacia complex were obtained only from CG.6210 soil. Rootstock genotypes that were grown in the orchard soil previously affected subsequent ARD severity, but replanting with the same or closely related rootstocks did not necessarily exacerbate this disease problem. Our results suggest that genotype-specific interactions with soil microbial consortia are linked with apple rootstock tolerance or susceptibility to ARD.     

Influence of production process design on inclusion bodies protein: the case of an Antarctic flavohemoglobin

Background  

Protein over-production in Escherichia coli often results in formation of inclusion bodies (IBs). Some recent reports have shown that the aggregation into IBs does not necessarily mean that the target protein is inactivated and that IBs may contain a high proportion of correctly folded protein. This proportion is variable depending on the protein itself, the genetic background of the producing cells and the expression temperature. In this paper we have evaluated the influence of other production process parameters on the quality of an inclusion bodies protein.     

Effect of hypophysectomy and growth hormone replacement on hypothalamic GHRH

Long-term (7 and 14 days) hypophysectomy resulted in a striking decrease in growth hormone releasing hormone-like immunoreactivity (GHRH-LI) in the median eminence (ME) of adult male rats, evaluated by both radioimmunoassay and immunohistochemistry. Treatment with human GH (125 μg/rat, twice daily IP for 14 days) prevented, though partially, depletion of GHRH-LI from the ME, as assessed by both methods. These results demonstrate that circulating GH levels regulate the function of GHRH-producing structures, via a feedback mechanism.     

Karyological evolution and systematics of Malagasy microhylid frogs

Microhylid frogs are a group of largely unresolved phylogeny, and diverse data sets are needed to improve the evolutionary understanding of these amphibians. We here report karyological data for 22 species of this family, belonging to the Malagasy genera Anodonthyla, Cophyla, Platypelis, Plethodontohyla, Rhombophryne, and Stumpffia (Cophylinae); Scaphiophryne and Paradoxophyla (Scaphiophryninae); and Dyscophus (Dyscophinae); and the Asian genera Calluella and Ramanella (Microhylinae). All species studied have 2n=26 chromosomes, most of which are metacentric or submetacentric. Chromosome morphology, banding pattern, and position of the nucleolar organizer regions (NORs) provide relevant characters for the understanding of the phylogeny and systematics of these frogs. The species of the Cophylinae are characterized by a subtelocentric or telocentric fourth chromosome pair (submetacentric only in Anodonthyla), which can be seen as a synapomorphy for this subfamily. Shifts in NOR position within the Cophylinae are frequent and agree with recent mitochondrial DNA data, corroborating the non-monophyly of the genus Plethodontohyla. Changes of NOR position and chromosome morphology (i.e., occurrence of subtelocentric and telocentric elements) were also common in this subfamily, possibly being related to their faster mitochondrial substitution rate and high species diversity. The ninth chromosome pair of the examined specimens of Dyscophus guineti, all juveniles, is heteromorphic. In this pair, one of the two chromosomes is longer due to the addition of two heterochromatic segments, raising the possibility that one chromosome of this pair may be a sex chromosome.     

Helper-dependent adenovirus for the gene therapy of proliferative retinopathies: stable gene transfer, regulated gene expression and therapeutic efficacy

BACKGROUND: Ocular neovascular disorders, such as diabetic retinopathy and age-related macular degeneration, are the principal causes of blindness in developed countries. Current treatments are of limited efficacy, whereas a therapy based on intraocular gene transfer of angiostatic factors represents a promising alternative. For the first time we have explored the potential of helper-dependent adenovirus (HD-Ad), the last generation of Ad vectors, in the therapy of retinal neovascularization. METHODS: We first analyzed efficiency and stability of intraretinal gene transfer following intravitreous injection in mice. A HD-Ad vector expressing green fluorescent protein (GFP) under the control of the cytomegalovirus (CMV) promoter (HD-Ad/GFP) was compared with a first-generation (E1/E3-deleted) Ad vector carrying an identical GFP expression cassette (FG-Ad/GFP). We also constructed HD-Ad vectors expressing a soluble form of the VEGF receptor (sFlt-1) in a constitutive (HD-Ad/sFlt-1) or doxycycline (dox)-inducible (HD-Ad/S-M2/sFlt-1) manner and tested their therapeutic efficacy upon intravitreous delivery in a rat model of oxygen-induced retinopathy (OIR). RESULTS: HD-Ad/GFP promoted long-lasting (up to 1 year) transgene expression in retinal Müller cells, in marked contrast with the short-term expression observed with FG-Ad/GFP. Intravitreous injection of HD-Ad vectors expressing sFlt-1 resulted in detectable levels of sFlt-1 and inhibited retinal neovascularization by more than 60% in a rat model of OIR. Notably, the therapeutic efficacy of the inducible vector HD-Ad/S-M2/sFlt-1 was strictly dox-dependent. CONCLUSIONS: HD-Ad vectors enable stable gene transfer and regulated expression of angiostatic factors following intravitreous injection and thus are attractive vehicles for the gene therapy of neovascular diseases of the retina.