96 research outputs found
Scanning Electron Microscopic Observations on Differentiation and Maintenance of Photoreceptor Cells in Vitro
Scanning electron microscopy was performed on cell cultures of embryonic and post-hatch chick retinas co-cultured with optic lobe neurons or in medium that had been pre-conditioned with optic lobe cells. The culture medium consisted of Eagles Basal Medium supplemented with glucose, fetal calf serum, glutamine and bicarbonate. Application of colchicine (SÎŒg/ml) to the cultures, encouraged the dissociation of retinal cell rosettes and optic lobe neuron aggregates, thereby allowing us to examine differentiation of isolated photoreceptor cells. Over time, developing photoreceptor cells gradually took on the morphological characteristics of rods and cones in the post-hatch chick: cells were polarized having a single neurite on one end of the cell and inner and outer segment-like structures on the other end. Developing cone cells elaborated an oil droplet and filopodial-like processes at the apical end of the inner segment. The latter may correspond to the calycal processes which normally envelop the basal 1/3 of the outer segment. The sequence of events noted in vitro parallel those previously reported in vivo
Decreasing mortality and changing patterns of causes of death in the Swiss HIV Cohort Study
Mortality among HIV-infected persons is decreasing, and causes of death are changing. Classification of deaths is hampered because of low autopsy rates, frequent deaths outside of hospitals, and shortcomings of International Statistical Classification of Diseases and Related Health Problems (ICD-10) coding
Novel TMC8 splice site mutation in epidermodysplasia verruciformis and review of HPV infections in patients with the disease
Epidermodysplasia verruciformis (EV) is a genodermatosis leading to infections with cutaneous HPV, persistent plane warts and a high rate of non-melanoma skin cancer (NMSC). Biallelic loss-of-function mutations in TMC6 and TMC8 are known to be causative.; The aim of this study was to report EV-causing mutations in four patients with EV and to give an overview of all described patients with EV.; We investigated four patients with classical features of EV from two families. All patients were affected by plane warts with typical EV histology since early childhood, and ÎČ-HPVs were detected on their skin. One patient had recurring cutaneous squamous cell carcinomas (cSCC) and carcinomas in situ (Bowen type). We sequenced both TMC6/8 for disease-causing mutations and quantified levels of gene expression. We also performed a systematic literature review to discuss these patients in the context of previously reported cases, mutations already identified, as well as HPV types.; Three patients of one family carried a homozygous splice site mutation in TMC8 resulting in aberrantly spliced transcripts that were not degraded. By contrast, no TMC6/8 mutation was detected in the patient from the other family. A systematic literature review revealed 501 described patients with EV. Around 40% of patients with EV analysed for genetic alterations carried no mutation in TMC6/8. While ÎČ-HPVs were identified in the majority of cases, α-HPVs were detected in several individuals.; The relatively high proportion of EV patients without mutation in TMC6/8 indicates the existence of EV-causing mutations in additional, presently unknown gene(s). However, a homozygous TMC8 splice site mutation in our patients resulted in aberrant transcripts which cannot retain the healthy phenotype. The literature review revealed that HPV-5 is the most commonly identified HPV in patients with EV, but HPV-3, HPV-14 and HPV-20 were unexpectedly identified more frequently than HPV-8
Tipping points and farmer decision-making in European permanent grassland (PG) agricultural systems
Permanent grasslands (PG) provide multifunctional ecosystem services (ES) in Europe and globally, which are threatened by both increased farming intensity and land use change in marginal areas. Farm management decisions can represent critical thresholds, or behavioural âtipping pointsâ, in the agricultural system. Decisions are influenced by a combination of agronomic, policy and social factors. Transformation of PG systems can be facilitated through positive tipping points and relevant policy implementation to ensure sustainable PG systems. The aim of this research was to understand the drivers of decisions regarding land use changes and management towards critical positive and negative tipping points across five biogeographic zones in Europe. Interview methodology assessed farmersâ preferences and priorities regarding the adoption of sustainable PG systems. Participants were selected from five case study countries, each representing a different biogeographic zone in Europe (Continental/Pannonian: Czech Republic, Boreal: Sweden, Mediterranean: Spain, Alpine: Switzerland, and Atlantic: UK). The sample also covered three farming intensity types within these biogeographic zones: high input/intensive conventional farms (â„1.0 LU /ha); low input/extensive conventional farms (<1.0 LU/ha); and certified organic farms. In total, 373 farm interviews were obtained from the case study countries between October 2020 and October 2021. The analysis focuses on drivers of change and considers tipping points across these countries, considering case studies of land use changes (specifically land abandonment) and land management practices (specifically changes in stocking rates). The most common reasons for PG management changes towards either intensification or extensification were economic. Farmers require policy support to increase provision of non-market ES, while rebalancing subsidies can deliver environmental ES at scale through abandonment (e.g., through the creation of specific habitats that support some threatened species). Agri-environment schemes (AES)and subsidies could be more flexible to allow farmers to better adapt grassland management to local production conditions and unpredictable circumstances such as droughts, floods, or market shocks. To maintain PG that delivers more goods and services, financial compensation for ES delivery was perceived to be the most significant support mechanism needed, while easier access to ES provision expertise through extension or consultancy services is considered important factor
Orexin-A and Orexin-B During the Postnatal Development of the Rat Brain
Orexin-A and orexin-B are hypothalamic neuropeptides isolated from a small group of neurons in the hypothalamus, which project their axons to all major parts of the central nervous system. Despite the extensive information about orexin expression and function at different parts of the nervous system in adults, data about the development and maturation of the orexin system in the brain are a bit contradictory and insufficient. A previous study has found expression of orexins in the hypothalamus after postnatal day 15 only, while others report orexins detection at embryonic stages of brain formation. In the present study, we investigated the distribution of orexin-A and orexin-B neuronal cell bodies and fibers in the brain at three different postnatal stages: 1-week-, 2-week-old and adult rats. By means of immunohistochemical techniques, we demonstrated that a small subset of cells in the lateral hypothalamus, and the perifornical and periventricular areas were orexin-A and orexin-B positive not only in 2-week-old and adult rats but also in 1-week-old animals. In addition, orexin-A and orexin-B expressing neuronal varicosities were found in many other brain regions. These results suggest that orexin-A and orexin-B play an important role in the early postnatal brain development. The widespread distribution of orexinergic projections through all these stages may imply an involvement of the two neurotransmitters in a large variety of physiological and behavioral processes also including higher brain functions like learning and memory
Hidden politics of power and governmentality in transitional justice and peacebuilding:The problem of âbringing the local back inâ
This paper examines âthe localâ in peacebuilding by examining how âlocalâ transitional justice projects can become spaces of power inequalities. The paper argues that focusing on how âthe localâ contests or interacts with âthe internationalâ in peacebuilding and post-conflict contexts obscures contestations and power relations amongst different local actors, and how inequalities and power asymmetries can be entrenched and reproduced through internationally funded local projects. The paper argues that externally funded projects aimed at emancipating âlocalsâ entrench inequalities and create local elites that become complicit in governing the conduct and participation of other less empowered âlocalsâ. The paper thus proposes that specific local actorsâoften those in charge of externally funded peacebuilding projectsâshould also be conceptualised as governing agents: able to discipline and regulate other local actorsâ voices and their agency, and thus (re)construct ideas about what âthe localâ is, or is not
Neurotrophin-3 upregulates NGF receptors in a central nervous system glial cell line
The low-affinity nerve growth factor (NGF) receptor (LNGFR) binds the neurotrophins NGF, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) with similar affinities. Here we report on the ability of NT-3 to regulate the expression of the LNGFR in C6 glioma cells. LNGFR-like immunoreactivity (LNGFR-IR) was examined in C6 cells treated for 16 h with NT-3 and exposed to the antibody 192-IgG followed by immunoglobulins conjugated with colloidal gold by means of ultrastructural morphometric analysis. Untreated C6 cells exhibited some positive LNGFR-IR, while C6 cells treated with NT-3 displayed significantly increased (2.3 fold) LNGFR-IR. The increase in LNGFR protein was accompanied by a greater quantity of LNGFR mRNA in NT-3-treated cells. Thus, LNGFR can be upregulated by the structurally related neurotrophin NT-
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