Accuracy of Different Rapid Urease Tests in Comparison with Histopathology in Patients with Endoscopic Signs of Gastritis.

BACKGROUND AND AIM: According to several guidelines, both invasive and non-invasive tests can be used to detect Helicobacter pylori (H. pylori). Invasive methods include H. pylori culture, histological staining, rapid urease tests (RUTs) and PCR. Non-invasive methods include urease breath test, stool antigen and serum IgG testing. The aim of our study was to compare all commercially available RUTs and histology in Germany. MATERIAL AND METHODS: One hundred fifty patients were enrolled in our study, irrespective of proton pump inhibitors (PPIs) or antibiotic use. If the results of RUTs and histology were diverging, real-time PCR to detect H. pylori DNA was undertaken. RESULTS: We detected no differences in the sensitivity or specificity between the different RUTs. In PPI and/or antibiotic-treated patients, RUTs seemed to be more sensitive for the detection of H. pylori infection compared to histology. In addition to the cheaper price of RUTs, they are also quicker to process. We show that histological staining in patients with signs of gastritis is expensive and not necessary, if there are no additional histological questions besides H. pylori status. CONCLUSIONS: In conclusion, we consider RUTs to be cheap and fast alternatives to histology in patients with endoscopic signs of gastritis, independently of whether PPIs or antibiotic are used. Histological evaluation is expensive, time consuming and may be unnecessary in some cases.

Mesenchymal stem cells prime proliferating adult neural progenitors toward an oligodendrocyte fate.

Oligodendrogenesis encompasses lineage specification of neural progenitor cells (NPCs) and differentiation into oligodendrocytes that ultimately culminates in the myelination of central nervous system axons. Each individual process must be tightly regulated by extracellular and cell-intrinsic mechanisms, whose identities are barely understood. We had previously demonstrated that soluble factors derived from rat mesenchymal stem cells (MSCs) induce oligodendrogenesis in differentiating adult NPCs under differentiation conditions. However, since lineage specification predominantly occurs in proliferating progenitors and not necessarily during early differentiation, we investigated if soluble factors derived from MSCs are able to prime NPCs to the oligodendroglial fate already under proliferation conditions. Therefore, we analyzed the effects of a 3 weeks stimulation of adult NPCs under proliferation conditions with conditioned media derived from MSCs (MSC-CM) in terms of cell morphology, proliferation, cell-specific marker expression profile, response to growth factor withdrawal (GFW), cell-lineage restriction, and expression of glial fate determinants. While MSC-CM did not affect the proliferation rate of NPCs, it boosted the formation of 2', 3'-cyclic-nucleotide-3'-phosphodieesterase (CNPase)- and myelin basic protein-expressing oligodendrocytes after GFW, even when cells were exposed to an astrogenic milieu. Moreover, it reinforced the proper development of oligodendrocytes, since it ensured a sustained expression of the functional marker CNPase. Finally, the presence of MSC-CM reduced the anti-oligodendrogenic determinant Id2 in proliferating NPCs, thus increasing the relative proportion of the pro-oligodendrogenic factor Olig2 expression. In summary, MSCs prime proliferating progenitors and, thus, reinforce cell fate choice and accelerate differentiation toward the oligodendrocyte lineage. The present findings underscore the potential use of MSCs in cell therapies for remyelination such as in multiple sclerosis and spinal cord injury. Moreover, they urge the identification of the oligodendrogenic activity(ies) derived from MSCs to develop novel molecular therapies for demyelinating diseases.

Identity, fate and potential of cells grown as neurospheres: species matters.

It is commonly accepted that adult neurogenesis and gliogenesis follow the same principles through the mammalian class. However, it has been reported that neurogenesis might differ between species, even from the same order, like in rodents. Currently, it is not known if neural stem/progenitor cells (NSPCs) from various species differ in their cell identity and potential. NSPCs can be expanded ex vivo as neurospheres (NSph), a model widely used to study neurogenesis in vitro. Here we demonstrate that rat (r) and mouse (m) NSph display different cell identities, differentiation fate, electrophysiological function and tumorigenic potential. Adult rNSph consist mainly of oligodendroglial progenitors (OPCs), which after repeated passaging proliferate independent of mitogens, whereas adult mNSph show astroglial precursor-like characteristics and retain their mitogen dependency. Most of the cells in rNSph express OPC markers and spontaneously differentiate into oligodendrocytes after growth factor withdrawal. Electrophysiological analysis confirmed OPC characteristics. mNSph have different electrophysiological properties, they express astrocyte precursor markers and spontaneously differentiate primarily into astrocytes. Furthermore, rNSph have the potential to differentiate into oligodendrocytes and astrocytes, whereas mNSph are restricted to the astrocytic lineage. The phenotypic differences between rNSph and mNSph were not due to a distinct response to species specific derived growth factors and are probably not caused by autocrine mechanisms. Our findings suggest that NSph derived from adult rat and mouse brains display different cell identities. Thus, results urge for caution when data derived from NSph are extrapolated to other species or to the in vivo situation, especially when aimed towards the clinical use of human NSph.