Fluorogenic detection of primary amines in plant histochemistry with fluorescamine: a comparative study on the effects of coagulant and non-coagulant fixatives.

The new highly sensitive method of fluorescamine reaction for the topochemical detection of primary amino groups was studied as a substitude of ninhydrin-Schiff's reaction for the localisation of total proteins in plant tissues. The influence of various coagulant and non-coagulant fixatives on the induction of fluorescamine fluorescence was examined: ethanol, formaldehyde gas and solution, glutaraldehyde, acrolein, osmium tetroxide, Bouin, Rossman, Clarke and Zenker's fluids and FMA were employed. It was found that the use of the fluorogenic method is conditioned by the fixative ability to keep the amino groups disposable and by its capability to reduce the natural autofluorescence of plant material. A detailed account of the fixation methodology demonstrated that non-coagulant acrolein and coagulant mercuric chloride are the most promising fixatives for the use of the fluorescamine reaction in plant histochemistry.     

The effect of laser radiations on human ceruloplasmin. Absorption, circular dichroism and electron paramagnetic resonance study.

Laser radiations at wavelengths ranging from 514.5 to 360.0 nm decolorize human ceruloplasmin. Kinetic behavior of the two chromophores absorbing at 610 nm, as measured by absorption and circular dichroism data, indicate different quantum yields of the two type I copper ions, whose maximum lies approximatively at 400 nm. Furthermore, as Electron Paramagnetic Resonance measurements demonstrate, the photochemical process involves reduction of the two type I copper ions leaving type II copper unchanged.     

LTR retrotransposon dynamics in the evolution of the olive (Olea europaea) genome

Improved knowledge of genome composition, especially of its repetitive component, generates important information for both theoretical and applied research. The olive repetitive component is made up of two main classes of sequences: tandem repeats and retrotransposons (REs). In this study, we provide characterization of a sample of 254 unique full-length long terminal repeat (LTR) REs. In the sample, Ty1-Copia elements were more numerous than Ty3-Gypsy elements. Mapping a large set of Illumina whole-genome shotgun reads onto the identified retroelement set revealed that Gypsy elements are more redundant than Copia elements. The insertion time of intact retroelements was estimated based on sister LTR’s divergence. Although some elements inserted relatively recently, the mean insertion age of the isolated retroelements is around 18 million yrs. Gypsy and Copia retroelements showed different waves of transposition, with Gypsy elements especially active between 10 and 25 million yrs ago and nearly inactive in the last 7 million yrs. The occurrence of numerous solo-LTRs related to isolated full-length retroelements was ascertained for two Gypsy elements and one Copia element. Overall, the results reported in this study show that RE activity (both retrotransposition and DNA loss) has impacted the olive genome structure in more ancient times than in other angiosperms.     

Oocyst shedding in cats vaccinated by the nasal and rectal routes with crude rhoptry proteins of Toxoplasma gondii

During this study, cats were immunized by the intranasal and rectal routes with crude rhoptry proteins of Toxoplasma gondii admixed with Quil-A. Twenty-five domestic short hair cats divided into five groups (n=5) were used during this evaluation: G1 and G3 cats received 200 μg of the rhoptry proteins with Quil-A (20 μg) by the intranasal and rectal routes, respectively; G2 and G4 cats received bovine serum albumin (BSA, 200 μg/dose) with Quil-A (20 μg); and G5 animals served as unvaccinated controls. All treatments were performed at days 0, 21, 42, and 63. The challenge was done with 800 cysts of the ME49 of T. gondii strain at day 70 (challenge day). The serum IgG, IgM, IgA, and fecal IgA antibody levels were evaluated by using the indirect enzyme-linked immunosorbent assay (ELISA). Some animals produced antibody levels beyond cut-off; however, two animals from G1 (OD(mean)=0.308, OD(cut-off)=0.200) and three from G3 (OD(mean)=0.254) demonstrated IgG levels on being challenged, with similar results occurring in two cats from G1 to IgM (OD(mean)=0.279, OD(cut-off)=0.200). Fecal IgA levels were detected in all G1 cats (OD(mean)=0.330, OD(cut-off)=0.065), and in one cat from G3 (OD(mean)=0.167). The serum and fecal humoral immune responses did not correlate with oocyst shedding. Oocyst shedding varied from 98.4% (G1), 87.5% (G2), 53.0% (G3), to 58% (G4), and was lower than that of G5 cats. The prepatent period of cats vaccinated intranasally (G1) was reduced from 6-9.6 to 2.8 days, suggesting protection of environmental contamination, considering cats as the primary source of contamination. The intranasally and rectally administered rhoptry vaccines were able to partially protect cats against T. gondii cysts on being challenged; however, the intranasal method of vaccination yielded better results relative to the rectal route.     

Influence of irradiance on in vitro growth and proliferation of Vaccinium corymbosum (highbush blueberry) and subsequent rooting in vivo

The effects of light on in vitro proliferation and subsequent in vivo rooting and acclimatisation of Vaccinium corymbosum were investigated. The shoots were exposed in vitro to different irradiances (total radiation ranging from 55 to 240 μmol m⁻² s⁻¹) for 7 to 60 days. In vitro growth and proliferation and the possible consequences on in vivo rooting were observed.
As compared to the control treatment (55 μmol m⁻² s⁻¹), higher irradiances improved proliferation and rooting ratios only with short applications (7 days). Short but high (210 μmol m⁻² s⁻¹) exposures applied at the end of the proliferation phase increased in vivo growth and rooting of the shoots. The shoots treated with strong light for longer times (14 and 28 days) showed both inhibition of growth and red colour of leaves and sprouts, and were less vigorous when transferred in vivo.     

Effects of peptidyl-prolyl isomerase 1 depletion in animal models of prion diseases

Pin1 is a peptidyl-prolyl isomerase that induces the cis-trans conversion of specific Ser/Thr-Pro peptide bonds in phosphorylated proteins, leading to conformational changes through which Pin1 regulates protein stability and activity. Since down-regulation of Pin1 has been described in several neurodegenerative disorders, including Alzheimer's Disease (AD), Parkinson's Disease (PD) and Huntington's Disease (HD), we investigated its potential role in prion diseases. Animals generated on wild-type (Pin1^+/+), hemizygous (Pin1^+/?) or knock-out (Pin1^?/?) background for Pin1 were experimentally infected with RML prions. The study indicates that, neither the total depletion nor reduced levels of Pin1 significantly altered the clinical and neuropathological features of the disease.