Intertribal somatic hybrids between Brassica napus and Thlaspi perfoliatum with high content of the T. perfoliatum-specific nervonic acid

Protoplast fusions were performed between hypocotyl protoplasts of Brassica napus and mesophyll protoplasts of Thlaspi perfoliatum. The two species are members of the Lepidieae and Brassiceae tribes, respectively, in the family of Brassicaceae. Seeds of T. perfoliatum are rich in the fatty acid C₂₄₁ (nervonic acid), an oil valuable for technical purposes. In the search for renewable oils to replace the mineral oils, plant breeders have been trying to develop oil crops with a high content of long-chain fatty acids. After fusion of B. napus protoplasts with non-irradiated as well as irradiated protoplasts of T. perfoliatum selection was carried out by flow cytometry and cell sorting. Of the shoots regenerated from different calli 27 were verified as hybrids or partial hybrids using the isoenzyme phosphoglucose isomerase (PGI) as a marker. Another 6 plants were identified as partial hybrids using a T. perfoliatum-specific repetitive DNA sequence. Slot blot experiments were performed to estimate the copy number of the repetitive DNA sequence in the parental species and in the hybrids. In T. perfoliatum there were approximately 10⁵ copies per haploid genome, and the range in the hybrids was 1–37% of the value in T. perfoliatum. When the nuclear DNA content of the regenerated shoots was analysed we found partial as well as symmetric hybrids. Even though the rooting and establishment of hybrid shoots in the greenhouse were difficult, resulting in the death of many plants, 19 plants were cultured to full maturity. Seeds obtained from 15 plants were analysed to determine whether they contained nervonic acid, and 5 of the hybrids were found to contain significantly greater amounts of nervonic acid than B. napus.     

A high frequency of intergenomic mitochondrial recombination and an overall biased segregation of B. campestris or recombined B. campestris mitochondria were found in somatic hybrids made within Brassicaceae

Mitochondrial segregation and rearrangements were studied in regenerated somatic hybrids from seven different species combinations produced using reproducible and uniform methods. The interspecific hybridizations were made between closely or more distantly related species within the Brassicaceae and were exemplified by three intrageneric, two intergeneric and two intertribal species combinations. The intrageneric combinations were represented by Brassica campestris (+) B. oleracea, B. napus (+) B. nigra and B. napus (+) B. juncea (tournefortii) hybrids, the intergeneric combinations by B. napus (+) Raphanus sativus and B. napus (+) Eruca sativa hybrids, and the intertribal combinations by B. napus (+) Thlaspi perfoliatum and B. napus (+) Arabidopsis thaliana hybrids. In each species combination, one of the two mitochondrial genotypes was B. campestris since the B. napus cultivar used in the fusions contained this cytoplasm. Mitochondrial DNA (mtDNA) analyses were performed using DNA hybridization with nine different mitochondrial genes as probes. Among the various species combinations, 43–95% of the hybrids demonstrated mtDNA rearrangements. All examined B. campestris mtDNA regions could undergo intergenomic recombination since hybrid-specific fragments were found for all of the mtDNA probes analysed. Furthermore, hybrids with identical hybrid-specific fragments were found for all probes except cox II and rrn18/rrn5, supporting the suggestion that intergenomic recombination can involve specific sequences. A strong bias of hybrids having new atp A-or atp9-associated fragments observed in the intra- and intergeneric combinations could imply that these regions contain sequences that have a high reiteration number, which gives them a higher probability of recombining. A biased segregation of B. campestris-or B. campestris-like mitochondria was found in all combinations. A different degree of phylogenetic relatedness between the fusion partners did not have a significant influence on mitochondrial segregation in the hybrids in this study.     

Plasma estriol levels after intramuscular injection of estriol and two of its esters

Twelve female volunteers from Berlin and 9 from Stockholm, all using a contraceptive pill (30 micrograms ethinyl estradiol and 150 micrograms levonorgestrel), received an intramuscular injection of estriol (E3; 1 mg in oil) on day 5 of withdrawal bleeding. Blood samples were collected at increasing time intervals during 4 weeks. Three months later, on day 5 of their withdrawal bleeding, 6 women were given intramuscularly (in oil) estriol 3,17-dipropionate (E3-prop) and 15 women estriol 3,17-dihexanoate (E3-hex). The doses were equivalent to 5 mg of estriol, i.e. 6.94 and 8.90 mg, respectively. Blood samples were collected during a period of 9 weeks. Estriol was analyzed by radioimmunoassay in all plasma samples. The average half-life of E3 ranged from 1.5 to 5.3 h after the administration of E3. It was 12.7 h and between 187 and 221 h after the administration of E3-prop and E3-hex, respectively. The average areas under the curve (in nmol.l-1.h) of E3 were between 82.5 and 161 after the administration of E3-prop or E3-hex, and between 27.1 and 37.9 when E3 had been given. As E3 was administered in a 5-fold lower dose than the esters, the areas under curve appeared to be comparable. Thus, the total exposure to E3 seemed to be almost independent of the type of E3 derivatization, while the time and intensity of exposure were very different.     

Complex temporal decay: a complete analysis

Relaxation dynamics is universal in science and engineering; its study serves to parameterize a system's response and to help identify a microscopic model of the processes involved. When measured data for a phenomenon cannot be fitted using one exponential, the choice of an alternative function to describe the decay becomes nontrivial. Here, we contrast two different, but fundamentally related approaches to fitting nontrivial decay curves; exponential decomposition and the gamma probability density function. Copyright © 2013 John Wiley & Sons, Ltd.     

Cortical potential imaging using L-curve and GCV method to choose the regularisation parameter

Background

The electroencephalography (EEG) is an attractive and a simple technique to measure the brain activity. It is attractive due its excellent temporal resolution and simple due to its non-invasiveness and sensor design. However, the spatial resolution of EEG is reduced due to the low conducting skull. In this paper, we compute the potential distribution over the closed surface covering the brain (cortex) from the EEG scalp potential. We compare two methods – L-curve and generalised cross validation (GCV) used to obtain the regularisation parameter and also investigate the feasibility in applying such techniques to N170 component of the visually evoked potential (VEP) data.

Methods

Using the image data set of the visible human man (VHM), a finite difference method (FDM) model of the head was constructed. The EEG dataset (256-channel) used was the N170 component of the VEP. A forward transfer matrix relating the cortical potential to the scalp potential was obtained. Using Tikhonov regularisation, the potential distribution over the cortex was obtained.

Results

The cortical potential distribution for three subjects was solved using both L-curve and GCV method. A total of 18 cortical potential distributions were obtained (3 subjects with three stimuli each – fearful face, neutral face, control objects).

Conclusions

The GCV method is a more robust method compared to L-curve to find the optimal regularisation parameter. Cortical potential imaging is a reliable method to obtain the potential distribution over cortex for VEP data.

     

Decreased binding capacity (B max) of muscarinic acetylcholine receptors in fibroblasts from boys with attention-deficit/hyperactivity disorder (ADHD)

Monoaminergic dysregulation is implicated in attention-deficit/hyperactivity disorder (ADHD), and methylphenidate and amphetamines are the most frequently prescribed pharmacological agents for treating ADHD. However, it has recently been proposed that the core symptoms of the disorder might be due to an imbalance between monoaminergic and cholinergic systems. In this study, we used fibroblast cell homogenates from boys with and without ADHD as an extraneural cell model to examine the cholinergic receptor density, that is, muscarinic acetylcholine receptors (mAChRs). We found that the binding capacity (B _max) of [³H] Quinuclidinyl benzilate (³H-QNB) to mAChRs was decreased by almost 50 % in the children with ADHD (mean = 30.6 fmol/mg protein, SD = 25.6) in comparison with controls [mean = 63.1 fmol/mg protein, SD = 20.5, p ≤ 0.01 (Student’s unpaired t test)]. The decreased B _max indicates a reduced cholinergic receptor density, which might constitute a biomarker for ADHD. However, these preliminary findings need to be replicated in larger ADHD and comparison cohorts.     

Symbiotic influence of endophytic Bacillus pumilus on growth promotion and probiotic potential of the medicinal plant Ocimum sanctum

Bacillus pumilus was isolated from surface-sterilized tissues of the medicinal plant Ocimum sanctum. Scanning electron microscopic (SEM) imaging confirmed the presence of a rod shaped bacterium within the plant tissues. The bacterium was identified as B. pumilus by biochemical analyses and 16S rRNA gene sequencing. In vitro analyses indicate that the isolated strain of B. pumilus was endowed with multiple plant growth promotion (PGP) traits such as phosphate solubilization and the production of indole acetic acid (IAA), siderophore and hydrogen cyanide (HCN). Phosphate solubilization (37.3 μg ml^?1) and IAA production (36.7 μg ml^?1) by the isolate was found to reach a maximum after 60 h of incubation. Siderophore mediated iron sequestration by B. pumilus may confer a competitive advantage to the host with respect to pathogen inhibition. Siderophore produced by the isolate was found to be of a trihydroxamate type with hexadentate nature. The B. pumilus isolate also exhibited cellulolytic, proteolytic and chitinolytic activity. Cell free supernatant, culture filtrates of the isolate were found to suppress the growth of fungal phytopathogens. The culture filtrate retained its antifungal activity even after exposure to heat. In addition to PGP, the isolate exhibited probiotic properties such as acid tolerance (pH2), bile salt tolerance (2 %), auto-aggregation, antibiotic resistance and the absence of haemolytic activity. These finding suggest the possibility of utilizing this endophytic strain of B. pumilus as a bioinoculant to enhance plant growth and also as a probiotic.     

A Preliminary Report on a Combined Gram-Pappen-Heim Stain for Formalin Fixed Tissues

Although the color of indigo is strongly dependent on its environment, it is blue in most commonly encountered situations. Indigo's absorption at such long wavelengths for such a small molecule is unique, and I provide here an overview of the concepts advanced to account for this feature. A traditional valence–bond approach may be used to provide a reasonable qualitative explanation. A more rigorous, quantitative explanation is provided by molecular orbital methods of varying degrees of sophistication and several explanations have been proposed based on these models. Commonly, it is suggested that the important structural unit in determining color is based on the cross-conjugated “H-chromophore” concept. A second closely related explanation describes it as two symmetrically coupled merocyanine chains. Another proposal suggests that the basic chromophore may be interpreted as the aza analogue of two coupled anti aromatic-cyclopentadienyl ions. PiSYSTEM, a commercially available quantum mechanics program, has been used to provide a successful quantitative account of the colors of indigo and indirubin, a red isomer.     

The ghrelin signalling system is involved in the consumption of sweets

The gastric-derived orexigenic peptide ghrelin affects brain circuits involved in energy balance as well as in reward. Indeed, ghrelin activates an important reward circuit involved in natural- as well as drug-induced reward, the cholinergic-dopaminergic reward link. It has been hypothesized that there is a common reward mechanism for alcohol and sweet substances in both animals and humans. Alcohol dependent individuals have higher craving for sweets than do healthy controls and the hedonic response to sweet taste may, at least in part, depend on genetic factors. Rat selectively bred for high sucrose intake have higher alcohol consumption than non-sucrose preferring rats and vice versa. In the present study a group of alcohol-consuming individuals selected from a population cohort was investigated for genetic variants of the ghrelin signalling system in relation to both their alcohol and sucrose consumption. Moreover, the effects of GHS-R1A antagonism on voluntary sucrose-intake and operant self-administration, as well as saccharin intake were investigated in preclinical studies using rodents. The effects of peripheral grelin administration on sucrose intake were also examined. Here we found associations with the ghrelin gene haplotypes and increased sucrose consumption, and a trend for the same association was seen in the high alcohol consumers. The preclinical data show that a GHS-R1A antagonist reduces the intake and self-administration of sucrose in rats as well as saccharin intake in mice. Further, ghrelin increases the intake of sucrose in rats. Collectively, our data provide a clear indication that the GHS-R1A antagonists reduces and ghrelin increases the intake of rewarding substances and hence, the central ghrelin signalling system provides a novel target for the development of drug strategies to treat addictive behaviours.     

Fatty acids in ADHD: plasma profiles in a placebo-controlled study of Omega 3/6 fatty acids in children and adolescents

The aim of this study was to assess baseline levels and changes in plasma fatty acid profiles in children and adolescents with ADHD, in a placebo-controlled study with Omega 3/6 supplementation, and to compare with treatment response. Seventy-five children and adolescents aged 8?C18?years with DSM-IV ADHD were randomized to 3?months of Omega 3/6 (Equazen eye q) or placebo, followed by 3?months of open phase Omega 3/6 for all. n-3, n-6, n-6/n-3 ratio, EPA and DHA in plasma were measured at baseline, 3 and 6?months. Subjects with more than 25?% reduction in ADHD symptoms were classified as responders. At baseline, no significant differences in mean fatty acid levels were seen across active/placebo groups or responder/non-responder groups. The 0?C3?month changes in all parameters were significantly greater in the active group (p?<?0.01). Compared to non-responders, the 6-month responders had significantly greater n-3 increase at 3?months and decrease in n-6/n-3 ratio at 3 and 6?months (p?<?0.05). Omega 3/6 supplementation had a clear impact on fatty acid composition of plasma phosphatidyl choline in active versus placebo group, and the fatty acid changes appear to be associated with treatment response. The most pronounced and long-lasting changes for treatment responders compared to non-responders were in the n-6/n-3 ratio.