1,881 research outputs found
The effect of ownership and competitive pressure on firm performance in transition countries. Micro evidence from Bulgaria, Romania and Poland.
Country; Firm performance; Ownership; Performance;
Role for nitric oxide in the development of the ferret retinogeniculate projection
Journal ArticleThe ferret retinogeniculate projection segregates into eye-specific layers during the first postnatal week and into ON/OFF sublaminae, which receive inputs from either on-center or off-center retinal ganglion cells, during the third and fourth postnatal weeks. The restriction of retinogeniculate axon arbors into eye-specific layers appears to depend on action potential activity () but does not require activation of NMDA receptors (). The formation of ON/OFF sublaminae is also activity-dependent and is disrupted by in vivo blockade of NMDA receptors (). To investigate a possible mechanism whereby blockade of postsynaptic NMDA receptors in the lateral geniculate nucleus (LGN) results in changes in the size and position of presynaptic axon arbors, we tested the role of the diffusible messenger nitric oxide (NO) in the development of the retinogeniculate pathway. We found previously that NO synthase (NOS) is transiently expressed in LGN cells during the refinement of retinogeniculate projections (). In this study, treatment with NG-nitro-L-arginine (L-NoArg), an arginine analog that inhibits NOS, during the third and fourth postnatal weeks resulted in an overall pattern of sublamination that was significantly reduced compared with normal and control animals. Single retinogeniculate axon arbors were located in the middle of eye-specific layers rather than toward the inner or outer half as in normal or control animals. The effect of NOS inhibition was not a consequence of the hypertensive effect of L-NoArg. In contrast to the effect of L-NoArg on the formation of ON/OFF sublaminae, treatment with L-NoArg during the first postnatal week did not disrupt the formation of eye-specific layers. Biochemical assays indicated significant inhibition of NOS during both treatment periods. These data suggest that NO acts together with NMDA receptors in activity-dependent refinement of connections during a specific phase of retinogeniculate development
A Scoping Review on Wearable Devices for Environmental Monitoring and Their Application for Health and Wellness
This scoping review is focused on wearable devices for environmental monitoring. First, the main pollutants are presented, followed by sensing technologies that are used for the parameters of interest. Selected examples of wearables and portables are divided into commercially available and research-level projects. While many commercial products are in fact portable, there is an increasing interest in using a completely wearable technology. This allows us to correlate the pollution level to other personal information (performed activity, position, and respiratory parameters) and thus to estimate personal exposure to given pollutants. The fact that there are no univocal indices to estimate outdoor or indoor air quality is also an open problem. Finally, applications of wearables for environmental monitoring are discussed. Combining environmental monitoring with other devices would permit better choices of where to perform sports activities, especially in highly polluted areas, and provide detailed information on the living conditions of individuals
Extracellular vesicles. New endogenous shuttles for mirnas in cancer diagnosis and therapy?
Extracellular Vesicles (EVs) represent a heterogeneous population of membranous cell-derived structures, including cargo-oriented exosomes and microvesicles. EVs are functionally associated with intercellular communication and play an essential role in multiple physiopathological conditions. Shedding of EVs is frequently increased in malignancies and their content, including proteins and nucleic acids, altered during carcinogenesis and cancer progression. EVs-mediated intercellular communication between tumor cells and between tumor and stromal cells can modulate, through cargo miRNA, the survival, progression, and drug resistance in cancer conditions. These consolidated suggestions and EVs’ stability in bodily fluids have led to extensive investigations on the potential employment of circulating EVs-derived miRNAs as tumor biomarkers and potential therapeutic vehicles. In this review, we highlight the current knowledge about circulating EVs-miRNAs in human cancer and the application limits of these tools, discussing their clinical utility and challenges in functions such as in biomarkers and instruments for diagnosis, prognosis, and therapy
Src family kinases as therapeutic targets in advanced solid tumors. What we have learned so far
Src is the prototypal member of Src Family tyrosine Kinases (SFKs), a large non-receptor kinase class that controls multiple signaling pathways in animal cells. SFKs activation is necessary for the mitogenic signal from many growth factors, but also for the acquisition of migratory and invasive phenotype. Indeed, oncogenic activation of SFKs has been demonstrated to play an important role in solid cancers; promoting tumor growth and formation of distant metastases. Several drugs targeting SFKs have been developed and tested in preclinical models and many of them have successfully reached clinical use in hematologic cancers. Although in solid tumors SFKs inhibitors have consistently confirmed their ability in blocking cancer cell progression in several experimental models; their utilization in clinical trials has unveiled unexpected complications against an effective utilization in patients. In this review, we summarize basic molecular mechanisms involving SFKs in cancer spreading and metastasization; and discuss preclinical and clinical data highlighting the main challenges for their future application as therapeutic targets in solid cancer progression
Tau oligomers accumulation sensitizes prostate cancer cells to docetaxel treatment
Purpose: Human tau is a highly dynamic, multifunctional protein expressed in different isoforms and conformers, known to modulate microtubule turnover. Tau oligomers are considered pathologic forms of the protein able to initiate specific protein accumulation diseases, called tauopathies. In our study, we investigated the potential association between autophagy and tau oligomers accumulation and its role in the response of prostate cancer cells to docetaxel. Methods: We evaluated in vitro the expression of tau oligomers in prostate cancer cell lines, PC3 and DU145, in presence of autophagy inhibitors and investigated the role of tau oligomers accumulation in resistance to docetaxel treatment. Results: Tau protein was basally expressed in prostate cancer lines as several monomeric and oligomeric forms. The pharmacologic inhibition of autophagy induced in cancer cells the accumulation of tau protein, with a prevalent expression of oligomeric forms. Immunofluorescence analysis of untreated cells revealed that tau was visible mainly in dividing cells where it was localized on the mitotic spindle. Inhibition of autophagy determined an evident upregulation of tau signal in dividing cells and the presence of aberrant monoastral mitotic spindles. The accumulation of tau oligomers was associated with DNA DSB and increased cytotoxic effect by docetaxel. Conclusions: Our data indicate that autophagy could exert a promoting role in cancer growth and during chemotherapy facilitating degradation of tau protein and thus blocking the antimitotic effect of accumulated tau oligomers. Thus, therapeutic strategies aimed at stimulating tau oligomers formation, such as autophagy inhibition, could be an effective adjuvant in cancer therapy
Hole dynamics in a quantum antiferromagnet beyond the retraceable path approximation
The one-hole spectral weight for two chains and two dimensional lattices is
studied numerically using a new method of analysis of the spectral function
within the Lanczos iteration scheme: the Lanczos spectra decoding method. This
technique is applied to the model for , directly in the
infinite size lattice. By a careful investigation of the first 13 Lanczos steps
and the first 26 ones for the two dimensional and the two chain cases
respectively, we get several new features of the one-hole spectral weight. A
sharp incoherent peak with a clear momentum dispersion is identified, together
with a second broad peak at higher energy. The spectral weight is finite up to
the Nagaoka energy where it vanishes in a non-analytic way. Thus the lowest
energy of one hole in a quantum antiferromagnet is degenerate with the Nagaoka
energy in the thermodynamic limit.Comment: RevTeX 3.0, SISSA preprint 156/93/CM/MB, 10 pages + postscript file
appended, contains more accurate calculations in Fig.
Detection of Helicobacter pylori by PCR on gastric biopsy specimens taken for CP test: comparison with histopathological analysis.
The aims of the present study were: (i) to assess whether H. pylori could be succesfully detected by PCR from the same biopsy sample used for CPtest; and ii) to evaluate CPtest comparatively to both PCR and histology for detection of H. pylori infection in dyspeptic patients. Three antral gastric biopsies were collected from each of 80 consecutive dyspeptic patients undergoing oesophagogastroduodenoscopy. Two biopsies were for histology (gold standard), one for CPtest, scored at 20min, 1h and 24h for the presence of urease activity. Gastric biopsy was then removed from CPtest and used for ureC-targeted PCR. Fifty-five (68.7%) patients were positive for H. pylori infection by histology. CPtest yielded an overall diagnostic accuracy of 93.8% (95% CI: 91–96.4%), regardless of observation period. No erroneous categorization of H. pylori status occurred using PCR, yielding sensitivity, specificity, positive and negative predictive values, and overall diagnostic accuracy of 100%. Our results suggest that H. pylori can be detected by PCR in gastric biopsies previously taken for CPtest, so reducing the workload of the endoscopist by saving additional biopsies for culture analysis and susceptibility tests
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