Histamine production during the anti-allograft response. Demonstration of a new lymphokine enhancing histamine synthesis

Histamine production is greatly increased during culture of allograft recipient spleen cells in the presence of immunizing cells (secondary mixed leukocyte cultures [MLC]) as compared to that found in primary MLC (i.e., without previous allograft). This phenomenon appears after 24 h of culture and reaches its maximum at 48 h. Optimal increased histamine production is observed when MLC is performed with spleen cells removed from mice during rejection. This increased production of histamine during secondary MLC results from the action of a lymphokine: the histamine-producing cell stimulating factor (HCSF). This factor is released by T lymphocytes. Its production requires specific stimulation of the recipient lymphocytes because increase in histamine production during secondary MLC can be only observed when recipient cells are cultured with stimulating cells bearing at least one homology at K or D loci with immunizing cells. HCSF acts on a cell which is present in bone marrow, spleen, blood, and peritoneal cells but absent in thymus or lymph node cells. This target cell is found in the less-dense layer of a discontinuous Ficoll-gradient of bone marrow cells. HCSF is heat stable, destroyed by trypsin treatment, and has a molecular weight between 50,000 and 100,000. It acts on its target cells by increasing histidine decarboxylase activity

New Russulaceae species in south-east Queensland

Russula species are ectomycorrhizal basidiomycetes common throughout Australian woodlands. Molecular and morphological examination of Russula specimens from various sites in South-east Queensland has uncovered a number of phylogenetically diverse and potentially undescribed specimens. At this stage, most of these remain as individual specimens. However, several specimens have been grouped into project species. In this presentation, two potentially new species of Russula will be described. Both species are widespread on red to black clay soils in the Toowoomba region and appear to be phylogenetically related to each other. Project species 1 has a white stipe which developed a pink flush after collection and red to pink centrally depressed cap with white gills. The spores of this species were subglobose, white and ornamented with amyloid warts connected in short chains. The second species, project species 3, is macroscopically similar, differing with its larger size, purple-pink cap colour, and rougher cap texture. Its spores are globose to subglobose, white and ornamented with small amyloid warts connected in short chains. Continued molecular and morphological studies of the Russula species of South-east Queensland may uncover more novel Australian species

Observational Learning During Simulation-Based Training in Arthroscopy: Is It Useful to Novices?

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.OBJECTIVE: Observing experts constitutes an important and common learning experience for surgical residents before operating under direct guidance. However, studies suggest that exclusively observing experts may induce suboptimal motor learning, and watching errors from non-experts performing simple motor tasks may generate better performance. We investigated whether observational learning is transferrable to arthroscopy learning using virtual reality (VR) simulation. SETTING/DESIGN: In our surgical simulation laboratory, we compared students learning basic skills on a VR arthroscopy simulator after watching an expert video demonstration of VR arthroscopy tasks or a non-expert video demonstration of the same tasks to a Control group without video demonstration. Ninety students in 3 observing groups (expert, non-expert, and Control) subsequently completed the same procedure on a VR arthroscopy simulator. We hypothesized the non-expert-watching group would outperform the expert-watching group, and both groups to outperform the Control group. We examined performance pretest, posttest, and 1 week later. PARTICIPANTS: Participants were recruited from the final year of medical school and the very early first year of surgical residency training programs (orthopaedic surgery, urology, plastic surgery, and general surgery) at Western University (Ontario, Canada). RESULTS: All participants improved their overall performance from pretest to retention (p < 0.001). At initial retention testing, non-expert-watching group outperformed the other groups in camera path length p < 0.05 and time to completion, p < 0.05, and both the expert/non-expert groups surpassed the Control group in camera path length (p < 0.05). CONCLUSION: We suggest that error-observation may contribute to skills improvement in the non-expert-watching group. Allowing novices to observe techniques/errors of other novices may assist internalization of specific movements/skills required for effective motor performances. This study highlights the potential effect of observational learning on surgical skills acquisition and offers preliminary evidence for peer-based practice (combined non-experts and experts) as a complementary surgical motor skills training strategy.This project was supported by a Physicians׳ Services Incorporated (PSI) Foundation, Canada grant. Funds were used to pay for salary and employee benefits (LvE). The PSI Foundation did not play a role in the investigation

Effects of fluoride on primary cultured haemocytes from the marine gastropod Haliotis tuberculata

International audienceAs a consequence of human's activities, fluoride concentration in many aquatic ecosystems is significantly increasing. Nevertheless, little is known about fluoride toxicity to aquatic life. In this study the effect of exposure to different concentrations of sodium fluoride (2, 10, 50, 250 and 1,250 μg mL −1) during 24 h on primary cultured haemocytes of the gastropod Haliotis tuberculata was realized. Results indicate no significant effect of NaF on cell viability, Lysosomal membrane stability, phagocytosis and ROS production at concentrations of 2, 10, 50 and 250 μg mL −1. Nevertheless, lysosomal membrane alterations, a decrease of phagocytosis and morphological changes of H. tuberculata haemocytes were observed at concentration of 1,250 µg mL −1 NaF suggesting a potential impact of NaF at high concentration in the environment

Optimization of the Touchscreen-Based Visuomotor Conditional Learning Task in Mice

The translational gap between animal models and clinical trials is a longstanding, yet largely unresolved, limitation in the study of cognition. This discrepancy is largely due to the differences in how cognition is assessed in animal models compared to those in clinical populations. In the stimulus-response (S-R) learning literature, for example, the techniques used to assess the acquisition of habitual behaviour differ greatly across species, leading to poor cross-species translation and often conflicting results. As a result, we set out to optimize a S-R learning task in mice using the touchscreen-based operant technologies. Similar to human studies, this touchscreen technique encourages animals to respond to visual stimuli displayed on a touchscreen according to a specific rule. Allowing for very similar, if not identical, cognitive assays in mice and men, this technique promotes high translational potential and a high degree of standardisation. Originally developed for rats, the Visuomotor Conditional Learning (VMCL) task encourages animals to learn arbitrary associations between visual stimuli and motor responses. In naïve C57BL/6 mice, we sought to optimize VMCL task parameters to promote better and more efficient responding, identifying the length of inter-trial intervals and the limited hold period as two potential candidates. The validation of this task will provide a novel means through which to study the neural correlates of S-R learning, and its use in conjunction with fiber photometry recordings may be provided

Molecular identification of fungal endophytes in Dipodium roseum roots

Dipodium or hyacinth orchids are large, fleshy, terrestrial orchids commonly seen in summer in Australian woodlands. Most species have limited chlorophyll, appear to be non-photosynthetic and rely on mycorrhizal fungi for their nutrition. Previous molecular investigations of the endophytic fungi of roots of Dipodium variegatum and Dipodium hamiltonianum have shown that the orchids are largely colonised by members of the ectomycorrhizal basidiomycete family, the Russulaceae. The fact that these plants consistently grew close to the base of Eucalyptus and Callitris trees suggested that the orchids acquire carbon and minerals from the tree host via an ectomycorrhizal connection. In the current project the fungal endophytes of Dipodium roseum were investigated for the first time. Orchid roots were sampled from multiple sites over two seasons in southern Queensland, Australia. DNA was extracted from colonised roots and isolated pelotons of the orchid. PCR amplification was conducted using ITS1F and ITS4 primers and following DNA purification, sent for Sanger sequencing at the Australian Genome Research Facility. BLAST searches of returned sequences against the GenBank database revealed a variety of fungi colonising the roots of D. roseum. This included a number of fungi not previously found as root endophytes of Orchidaceae species

Setting an International Research Agenda for Fear of Cancer Recurrence: an online delphi consensus study

This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permissionBackground: Fear of cancer recurrence (FCR) is common amongst cancer survivors. There is rapidly growing research interest in FCR but a need to prioritise research to address the most pressing clinical issues and reduce duplication and fragmentation of effort. This study aimed to establish international consensus among clinical and academic FCR experts regarding priorities for FCR research. Methods: Members of the International Psycho-oncology Society (IPOS) Fear of Cancer Recurrence Special Interest Group (FORwards) were invited to participate in an online Delphi study. Research domains identified in Round 1 were presented and discussed at a focus group (Round 2) to consolidate the domains and items prior to presentation in further survey rounds (Round 3) aimed at gaining consensus on research priorities of international significance. Results: Thirty four research items were identified in Round 1 and 33 of the items were consolidated into 6 overarching themes through a focus group discussion with FCR experts. The 33 research items were presented in subsequent rounds of the delphi technique. Twenty one participants contributed to delphi round 1, 16 in round 2 and 25 and 29 participants for subsequent delphi rounds. Consensus was reached for 27 items in round 3.1. A further 4 research items were identified by panellists and included in round 3.2. After round 3.2, 35 individual research items were ratified by the panellists. Given the high levels of consensus and stability between rounds no further rounds were conducted. Overall intervention research was considered the most important focus for FCR research. Panellists identified models of care that facilitate greater access to FCR treatment and evaluation of the effectiveness of FCR interventions in real world settings as the two research items of highest priority. Defining the mechanisms of action and active components across FCR/P interventions, was the third highest priority identified. Conclusions: The findings of this study outline a research agenda for international FCR research. Intervention research to identify models of care that increase access to treatment, are based on a flexible approach based on symptom severity and can be delivered within routine clinical care, were identified as research areas to prioritise. Greater understanding of the active components and mechanisms of action of existing FCR interventions will facilitate increased tailoring of interventions to meet patient need