Deacylated lipopolysaccharide inhibits plasminogen activator inhibitor-1, prostacyclin, and prostaglandin E2 induction by lipopolysaccharide but not by tumor necrosis factor-alpha

Bacterial LPS and TNF induce vascular endothelial cells to express a variety of response molecules. LPS that is partially deacylated (dLPS) by a human neutrophil enzyme blocks the ability of LPS, but not TNF, to augment one of these responses, the expression of endothelial cell surface molecules that promote neutrophil adherence (J. Exp. Med. 1987; 165:1393-1402). We show that dLPS can inhibit the ability of LPS, but not TNF, to elicit the expression of plasminogen activator inhibitor-1 (PAI-1), prostacyclin, and PGE2 by human umbilical vein endothelial cells. dLPS also prevented the accumulation of specific PAI-1 mRNA in response to LPS, but not to TNF. Neither the LPS- or TNF-induced expression of PAI-1 nor the dLPS inhibition of the LPS response was mediated by prostanoids. These results indicate that dLPS can specifically block a variety of endothelial cell responses to LPS and provide support for the hypotheses 1) that dLPS and LPS may interact with a common target molecule on or in endothelial cells, and 2) that dLPS, produced by enzymatic deacylation of LPS in vivo, could inhibit endothelial cell stimulation by LPS and thereby limit the host inflammatory response to invasive gram-negative bacteria.     

Species distribution modeling and molecular markers suggest longitudinal range shifts and cryptic northern refugia of the typical calcareous grassland species Hippocrepis comosa (horseshoe vetch)

Calcareous grasslands belong to the most diverse, endangered habitats in Europe, but there is still insufficient information about the origin of the plant species related to these grasslands. In order to illuminate this question, we chose for our study the representative grassland species Hippocrepis comosa (Horseshoe vetch). Based on species distribution modeling and molecular markers, we identified the glacial refugia and the postglacial migration routes of the species to Central Europe. We clearly demonstrate that H. comosa followed a latitudinal and due to its oceanity also a longitudinal gradient during the last glacial maximum (LGM), restricting the species to southern refugia situated on the Peninsulas of Iberia, the Balkans, and Italy during the last glaciation. However, we also found evidence for cryptic northern refugia in the UK, the Alps, and Central Germany. Both species distribution modeling and molecular markers underline that refugia of temperate, oceanic species such as H. comosa must not be exclusively located in southern but also in western of parts of Europe. The analysis showed a distinct separation of the southern refugia into a western cluster embracing Iberia and an eastern group including the Balkans and Italy, which determined the postglacial recolonization of Central Europe. At the end of the LGM, H. comosa seems to have expanded from the Iberian refugium, to Central and Northern Europe, including the UK, Belgium, and Germany.     

Soil seed bank contributes significantly to genetic variation of Hypericum sinaicum in a changing environment

The contribution of soil seed bank of a desert endemic plant species in maintaining genetic diversity has been addressed in this paper through investigating the differences in genetic diversity and structure (using AFLP markers) between plants grown from soil seed bank and standing crop plants within and among five populations of H. sinaicum growing at St. Katherine Protectorate, southern Sinai, Egypt. Standard genetic diversity measures showed that the molecular variation within and among populations was highly significantly different between standing crop and soil seed bank. While soil seed bank had lower genetic diversity than standing crop populations, pooling soil seed bank with standing crop samples resulted in higher diversity. The results revealed also that soil seed bank had lower differentiation (7 %) than among populations of the standing crop (18 %). Results of neighbor-joining, Bayesian clustering and principal coordinate analysis showed that soil seed banks had a separate gene pool different from standing crop. The study came to the conclusion that the genetic variation of the soil seed bank contributes significantly to the genetic variation of the species. This also stresses the importance of elucidating the genetic diversity and structure of the soil seed bank for any sound and long-term conservation efforts for desert species. These have been growing in small-size populations for a long time that any estimates gained only from aboveground sampling of populations may be ambiguous.     

A simple and efficient method for DNA extraction from grapevine cultivars andVitis species

A quick, simple, and reliable method for the extraction of DNA from grapevine species, hybrids, andAmpelopsis brevipedunculata (Vitaceae) has been developed. This method, based on that of Doyle and Doyle (1990), is a CTBA-based extraction procedure modified by the use of NaCl to remove polysaccharides and PVP to eliminate polyphenols during DNA purification. The method has also been used successfully for extraction of total DNA from other fruit species such as apple (Malus domestica), apricot (Prunus armeniaca), cherry (Prunus avium), peach (Prunus persica), plum (Prunus domestica), and raspberry (Rubus idaeus). DNA yield from this procedure is high (up to 1 mg/g of leaf tissue). DNA is completely digestible with restriction endonucleases and amplifiable in the polymerase chain reaction (PCR), indicating freedom from common contaminating compounds.     

Issues in using whole slide imaging for diagnostic pathology: “routine” stains,immunohistochemistry and predictive markers

The traditional microscope, together with the “routine” hematoxylin and eosin (H & E) stain, remains the “gold standard” for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of “stains” available. Because of the need for specific identification and even measurement of “biomarkers,” immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.     

Buchbesprechungen

Ohne Zusammenfassung     

Flavonoids from Flindersia australis

Dihydrokaempferol, dihydrokaempferol 3-O-rhamnoside (engeletin) and kaempferol were isolated from the stem bark of Flindersia australis. This is the first report of the occurrence of these flavonoids in Flindersia.     

Identification of DNA sequence variation in Campylobacter jejuni strains associated with the Guillain-Barré syndrome by high-throughput AFLP analysis

Background  

Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barré (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular.     

Habitat matters – Strong genetic and epigenetic differentiation in Linum catharticum from dry and wet grasslands

Plant species differ in their ecological amplitude, with some species occurring in very different habitats under strongly differentiated environmental conditions. We were interested in to what extent the occurrence of Linum catharticum in dry calcareous grasslands (Bromion) and wet litter meadows (Molinion), two habitats on opposing ends concerning, for example, moisture level, is reflected on the genetic and epigenetic level. Using AFLP (amplified fragment length polymorphisms) and MSAP (methylation sensitive amplification polymorphisms) analyses, we studied the genetic and epigenetic variation of L. catharticum from calcareous grasslands and litter meadows. From each habitat, we included five study sites with 16 individuals per sampling location. We observed lower genetic than epigenetic diversity, but considerable differentiation among habitats, which was stronger on the genetic than the epigenetic level. Additionally, we observed a strong correlation of genetic and epigenetic distance, irrespective of geographic distance. The dataset included a large portion of fragments exclusively found in individuals from one or the other habitat. Some epigenetic fragments even occurred in different methylation states depending on the habitat. We conclude that environmental effects act on both the genetic and epigenetic level, producing the clear differentiation among plant individuals from calcareous grasslands and litter meadows. These results may also point into the direction of ecotype formation in this species.