Glia conditioned medium protects fetal rat midbrain neurones in culture from L-DOPA toxicity

L-DOPA kills dopamine neurones in culture but is the most effective drug for the treatment of Parkinson's disease, where it exhibits no clear toxicity. While glial cells surround and protect neurones in vivo, neurones are usually cultured in vitro in the absence of glia. We treated fetal midbrain rat neurones with L-DOPA, mesencephalic glia conditioned medium (CM) and L-DOPA + CM. L-DOPA reduced the number of tyrosine hydroxylase-positive (TH+) cells and [3H]DA uptake, and increased quinone levels. L-DOPA + CM restored [3H]DA uptake and quinone levels to normal, and increased the number of TH+ cells and terminals to 170% of control. CM greatly increased the number of TH+ cells and [3H]DA uptake. Mesencephalic glia therefore produced soluble factors which are neurotrophic for dopamine neurones, and which protect these neurones from the toxic effects of L-DOPA.     

Subject Positions and Power Relations in Creative Organizations: Taking a Discursive View on Organizational Creativity

In this paper we take a discursive view on organizational creativity and examine subject positions and power relations produced within a discourse on creativity in two different kinds of creative organizations, an opera house and a games company. In particular, we focus on the ways in which the discourse is practised in creative production processes. The two cases illustrate how the macro‐level discourse on creativity can be enacted in a more micro‐level construction of subjectivities. In the study we identified several subject positions that were shared by both organizations, and examined how they were embedded in the organizations' formal and informal hierarchies. By taking a discursive approach to creativity, we have also been able to explore some unwanted consequences of emphasizing creativity in organizations.     

Defoliation-induced responses in peroxidases,phenolics, and polyamines in scots pine (Pinus sylvestris L.) needles

Effects of artificial defoliation on defensive needle chemistry in Scots pine (Pinus sylvestris L.) were evaluated with particular emphasis on peroxidases, phenolic compounds, soluble sugars, polyamines, and foliar nitrogen levels. The study was carried out on a nutrient-poor Scots pine stand with 8- to 25-year-old trees. Defoliation treatment consisted of repeated defoliation in two successive years with respective control trees. Defoliation was done before needle flushing by removing all mature needles. Guaiacol peroxidase activity increased in the needles after the first defoliation. The difference between treatments diminished towards autumn, and disappeared before the second defoliation in the next summer. After the second defoliation, the activities showed a similar trend. Apparently, peroxidases are involved in inducible chemical changes and recovery reactions that occur in the intact needles shortly after defoliation. After the second defoliation, total nitrogen concentration in the current year needles was about 20% lower, and free putrescine (a polyamine) concentration was 40% lower in the defoliated trees than in control needles. These changes indicate a loss of nitrogen due to defoliation. Specific phenolic compounds such as quercitrin, (+)-catechin, and two catechin derivatives increased in current year needles in response to defoliation. Accumulation of starch and sucrose in the current year needles of repeatedly defoliated trees may imply decreased assimilate transport. The results are indicative that changes in needle phytochemistry in response to defoliation accompany changes in needle nitrogen metabolism.     

Environmental Stimuli Shape Biofilm Formation and the Virulence of Periodontal Pathogens

Periodontitis is a common inflammatory disease affecting the tooth-supporting structures. It is initiated by bacteria growing as a biofilm at the gingival margin, and communication of the biofilms differs in health and disease. The bacterial composition of periodontitis-associated biofilms has been well documented and is under continual investigation. However, the roles of several host response and inflammation driven environmental stimuli on biofilm formation is not well understood. This review article addresses the effects of environmental factors such as pH, temperature, cytokines, hormones, and oxidative stress on periodontal biofilm formation and bacterial virulence.     

Vitamin D Deficiency Induces Chronic Pain and Microglial Phenotypic Changes in Mice

The bioactive form of vitamin D, 1,25-dihydroxyvitamin D (1,25D3), exerts immunomodulatory actions resulting in neuroprotective effects potentially useful against neurodegenerative and autoimmune diseases. In fact, vitamin D deficiency status has been correlated with painful manifestations associated with different pathological conditions. In this study, we have investigated the effects of vitamin D deficiency on microglia cells, as they represent the main immune cells responsible for early defense at central nervous system (CNS), including chronic pain states. For this purpose, we have employed a model of low vitamin D intake during gestation to evaluate possible changes in primary microglia cells obtained from postnatal day(P)2-3 pups. Afterwards, pain measurement and microglia morphological analysis in the spinal cord level and in brain regions involved in the integration of pain perception were performed in the parents subjected to vitamin D restriction. In cultured microglia, we detected a reactive—activated and proliferative—phenotype associated with intracellular reactive oxygen species (ROS) generation. Oxidative stress was closely correlated with the extent of DNA damage and increased β-galactosidase (B-gal) activity. Interestingly, the incubation with 25D3 or 1,25D3 or palmitoylethanolamide, an endogenous ligand of peroxisome proliferator-activated-receptor-alpha (PPAR-α), reduced most of these effects. Morphological analysis of ex-vivo microglia obtained from vitamin-D-deficient adult mice revealed an increased number of activated microglia in the spinal cord, while in the brain microglia appeared in a dystrophic phenotype. Remarkably, activated (spinal) or dystrophic (brain) microglia were detected in a prominent manner in females. Our data indicate that vitamin D deficiency produces profound modifications in microglia, suggesting a possible role of these cells in the sensorial dysfunctions associated with hypovitaminosis D.     

Novel insights into the epidemiology of Clostridium perfringens type A food poisoning

Clostridium perfringens food poisoning ranks among the most common gastrointestinal diseases in developed countries. The disease is caused by C. perfringens enterotoxin (CPE) encoded by cpe and produced by less than 5% of C. perfringens type A strains. Molecular epidemiological research in the past 15 years has focused on the reservoirs and routes of cpe-positive C. perfringens aiming to clarify the role and epidemiology of chromosomal and plasmid-borne cpe-carrying strains. This literature review highlights novel aspects in the epidemiology of CPE-mediated diseases. We suggest that (1) chromosomal and plasmid-borne cpe-carrying C. perfringens strains are genetically and epidemiologically distinct and have adapted to different environments; (2) not only chromosomal but also plasmid-borne cpe-carrying C. perfringens strains cause food poisonings; (3) other CPE-mediated diseases, such as antibiotic-associated and sporadic diarrhea, associated with plasmid-borne cpe-positive strains, may be food-related; (4) the role of animals as the main reservoir of cpe-positive C. perfringens needs to be reconsidered; (5) humans serve as an important reservoir of cpe-positive C. perfringens, introducing a contamination risk into foods through handling; and (6) the current standard procedures to diagnose C. perfringens food poisoning fail to detect and isolate many C. perfringens strains, distorting the epidemiological understanding of C. perfringens food poisoning.     

Enzyme-linked immunosorbent assay quantification of cytokine concentrations in human meningiomas

OBJECTIVE: To gain insight into the network of cytokine gene expression in the brain tumor microenvironment, we investigated the presence of the following cytokines in freshly excised brain tumors: interleukin (IL)-1 beta, IL-2, IL-4, and IL-6. METHODS: Tumor specimens from nine meningiomas were grown as tissue explants. The supernatants from the explants were tested for the presence of the aforementioned cytokines via the enzyme-linked immunosorbent assay method. RESULTS: IL-6, which is thought to stimulate acute protein phase synthesis, neovascularization, and cell proliferation, was found in all of the samples in greater concentrations than the other cytokines tested. IL-1 beta, another stimulatory cytokine thought to be involved in acute protein phase synthesis and cell proliferation, was also found in 100% of the samples tested, in concentrations significantly lower than those of IL-6. As expected, the presence of IL-2 and IL-4 was not detectable in any of the samples. CONCLUSION: This study is the first to clearly determine the relative concentrations of IL-1 beta and IL-6, using enzyme-linked immunosorbent assay quantification. These findings are an important precursor to future studies using antibodies to IL-1 beta and IL-6 and antibodies to IL-6 receptors to modulate neoplastic growth both in vitro and in vivo.     

The microvascularization of the choroid plexus of the lateral ventricles in the goat (Capra hircus)

The goat choroid plexus angioarchitecture of the lateral ventricles was studied under the SEM using the method of "microvascular corrosion casts". The whole plexus is semilunar shaped and directed in an antero-posterior, latero-median fashion. In the plexus the lateral extremity is larger than the median one. All the components of the vascular bed (arteries, veins and capillaries) of the choroid plexus have interesting morpho-structural features. In particular, the capillaries are more developed than the other components and they are variously located on both sides of the plexus. The capillary network has a various organization in different zones of each side of the plexus.     

CD146+ Pericytes Subset Isolated from Human Micro-Fragmented Fat Tissue Display a Strong Interaction with Endothelial Cells: A Potential Cell Target for Therapeutic Angiogenesis

Pericytes (PCs) are mesenchymal stromal cells (MSCs) that function as support cells and play a role in tissue regeneration and, in particular, vascular homeostasis. PCs promote endothelial cells (ECs) survival which is critical for vessel stabilization, maturation, and remodeling. In this study, PCs were isolated from human micro-fragmented adipose tissue (MFAT) obtained from fat lipoaspirate and were characterized as NG2⁺/PDGFRβ⁺/CD105⁺ cells. Here, we tested the fat-derived PCs for the dispensability of the CD146 marker with the aim of better understanding the role of these PC subpopulations on angiogenesis. Cells from both CD146-positive (CD146⁺) and negative (CD146⁻) populations were observed to interact with human umbilical vein ECs (HUVECs). In addition, fat-derived PCs were able to induce angiogenesis of ECs in spheroids assay; and conditioned medium (CM) from both PCs and fat tissue itself led to the proliferation of ECs, thereby marking their role in angiogenesis stimulation. However, we found that CD146⁺ cells were more responsive to PDGF-BB-stimulated migration, adhesion, and angiogenic interaction with ECs, possibly owing to their higher expression of NCAM/CD56 than the corresponding CD146⁻ subpopulation. We conclude that in fat tissue, CD146-expressing cells may represent a more mature pericyte subpopulation that may have higher efficacy in controlling and stimulating vascular regeneration and stabilization than their CD146-negative counterpart.