Resistance to cymbidium ringspot tombusvirus infection in transgenic Nicotiana benthamiana plants expressing the virus coat protein gene

Transgenic Nicotiana benthamiana plants expressing the coat protein gene of cymbidium ringspot virus (CyRSV) were tested for resistance against infection with CyRSV. Transgenic plants showed resistance to infection only when the purified virions concentration in the inoculum was as low as 0.05 g/ml. No protection was observed in transgenic plants inoculated with virion concentrations of 0.5 and 5.0 g/ml or when the inoculum was in vitro synthesized genomic RNA.     

Detection,characterization, and phytotoxic activity of the nucleoside antibiotics,Blasticidin S and 5-Hydroxylmethyl-Blasticidin S

Screening for herbicidal compounds carried out on culture broths of Streptomyces strains isolated from soil resulted in the detection of potent phytotoxic activity. The active principles were isolated, and identified as the nucleoside antibiotics Blasticidin S (Bl-S) and 5-Hydroxymethyl-Blasticidin S (H-M-Bl-S). Bl-S was more active than H-M-Bl-S on seedling germination in petri dishes and in postemergence greenhouse tests. Moreover both antibiotics were more phytotoxic to dicotyledonous than to monocotyledonous plants. The increased sensitivity of dicots was confirmed in carrot and rice cell cultures. Both compounds also inhibited [¹⁴C]amino acid incorporation into proteins of rice and carrot cell cultures. Protein synthesis was more affected in carrot than rice.     

Biotechnological suitability of Saccharomycodes ludwigii for fermented beverages

Nineteen Saccharomycodes ludwigii strains were tested for the production of secondary products in grape must fermentation. A predominant metabolic pattern characterized by high production of isobutyl alcohol, acetoin and ethyl acetate was obtained. The occurrence of some strains producing enhanced amounts of these compounds suggests a potential utilization of this species for industrial applications. Feijoa juice was inoculated with a selected S'codes ludwigii strain in comparison to a control strain of S. cerevisiae and evaluation of the fermented products was carried out by 30 consumers with respect to the odour, flavour and taste. The sample fermented by S'codes ludwigii was characterized by a fresh odour with a fruity flavour, identified as flavour of apple and kiwi-fruit. This product was compared to apple juice, with a more acid taste. Despite the high concentrations of acetic acid, this beverage might be considered a potential summer refreshing drink, addressed to a target of consumers who prefer fruit drinks that leave a slightly acid and little sugary taste in the mouth.     

Change in renal heme oxygenase expression in cyclosporine A-induced injury.

Cyclosporine A (CsA) is the first immunosuppressant used in allotransplantation. Its use is associated with side effects that include nephrotoxicity. This study explored the anatomic structures involved in CsA nephrotoxicity and the effect of heme oxygenase (HO) in preventing CsA injury. Rats were divided into four groups, which were treated with olive oil, CsA (15 mg/kg/day), CsA plus the HO inhibitor (SnMP; 30 microM/kg/day), and with the HO inducer (CoPP; 5 mg/100 g bw). Renal tissue was treated for morphological, biochemical, and immunohistochemical studies. CsA-treated rats showed degenerative changes with renal fibrosis localized mainly around proximal tubules. Collapsed vessels were sometimes seen in glomeruli. No HO-1 expression and increased expression of endothelin-1 (ET-1) were observed in CsA-treated rats compared with controls. In CsA plus SnMP-treated rats, HO-1 expression was further reduced and the morphology was not changed compared to the CsA group, whereas CsA plus CoPP-treated animals again showed normal morphology and with restoration and an increase in HO-1 levels. HO activity and immunohistochemical data showed similar alterations as HO expression. No changes were observed for HO-2 analysis. The observations indicate that HO-1 downregulation and ET-1 upregulation by CsA might be one mechanism underlying CsA-induced nephrotoxicity. Therefore, attempts to preserve HO levels attenuate CsA nephrotoxicity.     

In vivo evidence that genetic background controls impulse-dependent dopamine release induced by amphetamine in the nucleus accumbens

Amphetamine is known to increase dopamine (DA) release by acting directly on dopamine transporters (DAT), primarily through a mechanism that is independent of impulse flow. We present evidence to show that impulse-dependent increase in DA outflow in the nucleus accumbens (NAc) is produced by amphetamine depending on genetic background. Systemic amphetamine produced higher accumbal DA release in the widely exploited C57BL/6J background than in the DBA/2J. By contrast, intra-accumbens perfusion using increasing doses of amphetamine dramatically increased DA outflow in the DBA/2J background, whereas very low DA outflow was evident in C57BL/6J mice. The fast sodium channel blocker tetrodotoxin infused through the microdialysis probe abolished accumbal DA release induced by systemic amphetamine only in the C57BL/6J background. Finally, medial prefrontal excitotoxic lesion abolished amphetamine-induced mesoaccumbens DA release in C57BL/6J mice, without significantly affecting it in the DBA/2J background. These results represent the first functional evidence in an in vivo study that amphetamine can increase DA release in the NAc mainly through an impulse-dependent mechanism regulated by prefronto-cortical glutamatergic transmission. Moreover, they point to a genetic control of impulse-dependent DA release in the accumbens, providing an exploitable tool to investigate aetiological factors involved in psychopathology and drug addiction.     

Menstrual cycle-related changes in plasma oxytocin are relevant to normal sexual function in healthy women

Circulating levels of the neuro-hypophysial nonapeptide oxytocin increase during sexual arousal and orgasm in both men and women. A few studies have evaluated the effect of the menstrual cycle on plasma oxytocin in normally cycling, sexually active, healthy fertile women using or not using contraceptive pills. In 20 ovulating women and 10 women taking an oral contraceptive (group 1 and group 2, respectively), sexual function, hormonal profile, and plasma oxytocin (OT) were evaluated throughout the menstrual cycle. In group 1, plasma OT was significantly lower during the luteal phase in comparison with both the follicular and ovulatory phases. Plasma oxytocin was significantly correlated with the lubrication domain of the Female Sexual Function Index (FSFI) during the luteal phase and showed a trend towards statistical significance during the follicular phase. In group 2, plasma OT did not show any significant fluctuation throughout the menstrual cycle, even though a significant correlation was evident with both the arousal and the lubrication domain of the FSFI during the assumption of the contraceptive pill. These findings suggest that plasma OT fluctuates throughout the menstrual cycle in normally cycling healthy fertile women with adequate sexual activity but not taking any oral contraceptive pill. Moreover, plasma OT levels significantly relates to the genital lubrication in both women taking and not taking oral contraceptive pill apparently confirming its role in peripheral activation of sexual function.     

A possible flip-flop genetic mechanism for reciprocal gene expression

Innexins are a family of transmembrane proteins involved in the formation of gap junctions, specific intercellular channels, in invertebrates. Analyses of the entire innexin family during Drosophila melanogaster embryonic development shows the occurrence of complex and specific patterns of expression of the different genes. Innexins inx-2 and inx-7, in general, do not appear to exhibit extensive co-expression in different D. melanogaster cellular compartments. We propose here a new and robust mechanism, based on our analysis of the genomic organization of inx-2 and inx-7, that structurally justifies the reciprocal expression of genes.     

A new susceptibility locus for migraine with aura in the 15q11-q13 genomic region containing three GABA-A receptor genes

Migraine is the most common type of chronic episodic headache. Several population-based family studies have suggested a strong genetic predisposition to migraine, especially migraine with aura (MA). Although several susceptibility loci have been identified, none of the numerous studies performed to date have led to the identification of a gene responsible for the more common forms of migraine. GABA-A receptors and their modulator sites seem to be involved in the pathophysiological events that underlie migraine. We report on clinical and molecular data from a total of 10 families with MA, in which MA segregates as an autosomal dominant trait and presents with homogeneous clinical features. After excluding linkage with the known candidate loci, we used a functional candidate approach and genotyped these families with markers from the 15q11-q13 genomic region, which contains the genes encoding GABA-A receptor subunits. Evidence of linkage was obtained with a parametric two-point linkage analysis (maximum LOD score of 5.56 at a recombination fraction of 0.001 for marker GABRB3) and was supported by multipoint analysis (maximum LOD score of 6.54 between markers D15S113 and D15S1019). The critical region spanned 3.6 Mb. These results provide the basis for further investigation of the hypothesized relationship between a GABA-A receptor dysfunction and migraine.     

Effect of nitric oxide on the growth of Chlamydophila pneumoniae

Chlamydophila pneumoniae is an important human intracellular pathogen; however, the pathogenesis of C. pneumoniae infection is poorly understood and the immune control mechanism versus host cells is not completely known. The role of the nitric oxide (NO) synthase pathway in inhibiting the ability of C. pneumoniae to infect macrophage J774 cells and the ability of NO to damage isolated C. pneumoniae were investigated. Exposure of infected cultures to recombinant murine gamma interferon (MurIFN-gamma) resulted in increased production of NO and reduced viability. Addition of 2-(N,N-diethylamino)-diazenolase-2-oxide before infection of J774 cells or during chlamydial cultivation released NO, both resulting in a reduction in the viability of C. pneumoniae in a dose-dependent way. These results indicate that immune control of chlamydial growth in murine macrophage cells may trigger a mechanism that includes NO release with effects on the multiplication of the microorganism, thus suggesting that NO may play a role in preventing the systemic spread of Chlamydia.