Polyethylenimine-mediated expression of transgenes in the acinar cells of rats salivary glands in vivo

Non viral-mediated transfection of plasmid DNA provides a fast and reliable way to express various transgenes in selected cell populations in live animals. Here, we show an improvement of a previously published method that is based on injecting plasmid DNA into the ductal system of the salivary glands in live rats. Specifically, using complexes between plasmid DNA and polyethyleneimine (PEI) we show that the expression of the transgenes is directed selectively to the salivary acinar cells. PEI does not affect the ability of cells to undergo regulated exocytosis, which was one of the main drawbacks of the previous methods. Moreover PEI does not affect the proper localization and targeting of transfected proteins, as shown for the apical plasma membrane water channel aquaporin 5 (AQP5). Overall, this approach, coupled with the use of intravital microscopy, permits to conduct localization and functional studies under physiological conditions, in a rapid, reliable, and affordable fashion

Moral Reasoning in Psychopaths

Patienten mit der psychischen Störung „Psychopathie“ zeigen ein Muster von emotionaler Abgestumpftheit, Impulsivität und unmoralischem Verhalten. Zur Untersuchung moralischen Urteilens wurden in der vorliegenden Studie alltagsrelevante Konflikte mit moralischem bzw. neutralem Inhalt entwickelt und 12 „psychopathischen“ forensischen Patienten sowie 12 nicht-psychopathischen forensischen Patienten präsentiert. „Psychopathische“ im Vergleich zu nicht-psychopathischen Patienten berichteten signifikant positivere Gefühle bei unmoralischen Entscheidungen als Nicht-Psychopathen. Außerdem wurden in der Gruppe der „Psychopathen“ im Vergleich zu den Nicht-Psychopathen signifikant häufiger unmoralische Entscheidungen auf moralische Konflikte getroffen. Diese Befunde deuten darauf hin, dass eine Störung der Emotionsverarbeitung ursächlich für dissoziales Verhalten bei „Psychopathen“ sein könnte.Psychopathic patients show a behavioral pattern that is characterized by indifference, impulsivity and antisocial behavior. To investigate moral reasoning we developed conflicts of everyday life with either moral or neutral content. These conflicts were then presented to a group of 12 psychopathic forensic patients as well as to a group of 12 non-psychopathic forensic patients.Psychopathic compared to non-psychopathic patients reported significantly higher positive feelings when choosing an immoral response alternative than non-psychopaths. Furthermore, psychopaths picked significantly more often an immoral response alternative in the conflicts with moral content than did the non-psychopaths. These results indicate that impairment in emotional processing abilities may be at the core of antisocial behavior in psychopathy

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Expression of plasmid DNA in the salivary gland epithelium: novel approaches to study dynamic cellular processes in live animals

The ability to dynamically image cellular and subcellular structures in a live animal and to target genes to a specific cell population in a living tissue provides a unique tool to address many biological questions in the proper physiological context. Here, we describe a powerful approach that is based on the use of rat submandibular salivary glands, which offer the possibility to easily perform intravital imaging and deliver molecules from the oral cavity, and plasmid DNA, which offers the advantage of rapid manipulations. We show that, under different experimental conditions, a reporter molecule can be rapidly expressed in specific compartments of the glands: 1) in the intercalated ducts, when plasmid DNA is administered alone, and 2) in granular ducts, striated ducts, and, to a lesser extent, acini, when plasmid DNA is mixed with replication-deficient adenovirus subtype 5 particles. Remarkably, we also found that gene expression can be directed to acinar cells when plasmid DNA is administered during isoproterenol-stimulated exocytosis, suggesting a novel mechanism of plasmid internalization regulated by compensatory endocytosis. Finally, as a practical application of these strategies, we show how the expression of fluorescently tagged molecules enables the study of the dynamics of various organelles in live animals at a resolution comparable to that achieved in cell cultures

A case of human poisoning by grayanotoxins following honey ingestion: elucidation of the toxin profile by mass spectrometry

<div><p>High-resolution mass spectrometry (HRMS) was applied for the detection of grayanotoxins (GrTx) in a contaminated honey sample. This sample was provided by a hospital due to a suspicion of intoxication after a patient had shown the typical symptoms of GrTx poisoning. Subsequent analysis proved the contamination with high amounts of GrTx and other toxins belonging to grayanane-type diterpenoids. This group of natural toxins is synthesised by the plant family Ericaceae and comprises more than 60 individual toxins, but only one compound is available as a reference standard. We applied a screening approach that easily confirms the presence or absence of GrTx without access to standards. By searching for predictable mass spectrometric fragment ions, including typical in-source fragments arising from collision-induced dissociation during electrospray ionisation, the complete toxin profile was screened and allowed the mass spectrometric identification of 15 individual GrTx. The potential of this approach is especially demonstrated by the fact that at least two of these toxins have not been previously described in the literature. A semi-quantitative estimation indicated a total toxin concentration of 358 mg kg⁻¹. An investigation of 49 honeys from the German retail market did not reveal the presence of GrTx.</p></div

Correction: Increasing Live Birth Rate by Preimplantation Genetic Screening of Pooled Polar Bodies Using Array Comparative Genomic Hybridization.

[This corrects the article DOI: 10.1371/journal.pone.0128317.]

Determination of pyrrolizidine alkaloids in tea, herbal drugs and honey

<div><p>Honey was previously considered to be one of the main food sources of human pyrrolizidine alkaloid (PA) exposure in Europe. However, comprehensive analyses of honey and tea sampled in the Berlin retail market revealed unexpected high PA amounts in teas. This study comprised the analysis of 87 honey as well as 274 tea samples including black, green, rooibos, melissa, peppermint, chamomile, fennel, nettle, and mixed herbal tea or fruit tea. Total PA concentrations in tea ranged from < LOD to 5647 µg kg⁻¹, while a mean value of about 10 µg kg⁻¹ was found in honey samples. Additionally, herbal drugs were investigated to identify the source of PA in teas. Results suggest that PA in tea samples are most likely a contamination caused by co-harvesting of PA-producing plants. In some cases such as fennel, anise or caraway, it cannot be excluded that these plants are able to produce PA themselves.</p></div