Project description:Transfusion-related acute lung injury (TRALI) remains a leading cause of transfusion-related deaths. In most cases, anti-leukocyte antibodies in the transfusion product trigger TRALI, but not all anti-leukocyte antibodies cause TRALI. It has been shown that the anti-major histocompatibility complex (MHC) class I antibody 34-1-2S (anti-H-2Kd) causes TRALI in BALB/c mice (MHC class I haplotype H-2Kd), whereas SF1.1.10 (anti-H-2Kd) does not. In C57BL/6 mice (MHC class I haplotype H-2Kb), TRALI only occurs when anti-MHC class I antibody AF6-88.5.5.3 (anti-H-2Kb) is administered together with a high dose of 34-1-2S. It remains unknown which specific antibody characteristics are responsible for eliciting TRALI. We therefore investigated several biological and structural features of 34-1-2S compared with other anti-MHC class I antibodies, which on their own do not cause TRALI: SF1.1.10 and AF6-88.5.5.3. No substantial differences were observed between the TRALI-causing 34-1-2S and the TRALI-resistant SF1.1.10 regarding binding affinity to H-2Kd. Regarding binding affinity to H-2Kb, only AF6-88.5.5.3 potently bound to H-2Kb, whereas 34-1-2S exhibited weak but significant cross-reactivity. Furthermore, the binding affinity to FcγRs as well as the Fc glycan composition seemed to be similar for all antibodies. Similar Fc glycosylation profiles were also observed for human TRALI-causing donor anti-HLA antibodies compared with human anti-HLA antibodies from control donors. 34-1-2S, however, displayed superior complement activation capacity, which was fully Fc dependent and not significantly dependent on Fc glycosylation. We conclude that TRALI induction is not correlated with Fab- and Fc-binding affinities for antigen and FcγRs, respectively, nor with the composition of Fc glycans; but increased Fc-mediated complement activation is correlated with TRALI induction.
Project description:Here we show the bacteriome of wasted chewing gums from five different countries and the microbial successions on wasted gums during three months of outdoors exposure. In addition, a collection of bacterial strains from wasted gums was set, and the biodegradation capability of different gum ingredients by the isolates was tested. Our results reveal that the oral microbiota present in gums after being chewed, characterised by the presence of species such as Streptococcus spp. or Corynebacterium spp., evolves in a few weeks to an environmental bacteriome characterised by the presence of Acinetobacter spp., Sphingomonas spp. and Pseudomonas spp. Wasted chewing gums collected worldwide contain a typical sub-aerial biofilm bacteriome, characterised by species such as Sphingomonas spp., Kocuria spp., Deinococcus spp. and Blastococcus spp. Our findings have implications for a wide range of disciplines, including forensics, contagious disease control, or bioremediation of wasted chewing gum residues.
Project description:Previous studies on chewing frequency across animal species have focused on finding a single universal scaling law. Controversy between the different models has been aroused without elucidating the variations in chewing frequency. In the present study we show that vigorous chewing is limited by the maximum force of muscle, so that the upper chewing frequency scales as the -1/3 power of body mass for large animals and as a constant frequency for small animals. On the other hand, gentle chewing to mix food uniformly without excess of saliva describes the lower limit of chewing frequency, scaling approximately as the -1/6 power of body mass. These physical constraints frame the -1/4 power law classically inferred from allometry of animal metabolic rates. All of our experimental data stay within these physical boundaries over six orders of magnitude of body mass regardless of food types.
Project description:BackgroundTransfusion-related acute lung injury (TRALI) is a rare but potentially fatal transfusion reaction. An effective haemovigilance programme is important in implementing successful and targeted risk reduction strategies. We aim to provide a summary of TRALI cases referred for investigation in Queensland (QLD) Australia from 1999 to 2019, describing the epidemiological and laboratory features of local TRALI cases.Materials and methodsA retrospective audit evaluated all cases reported to the QLD Australian Red Cross Lifeblood over the 20-year study period. Cases were categorised according to the 2004 Canadian consensus criteria.ResultsOf the 91 cases referred for investigation, expert review confirmed 30 of TRALI and 18 of possible TRALI. A total of 238 donors and 110 blood products were assessed in confirmed cases. TRALI affected patients of all ages. Most patients had underlying haematological malignancies (25%), surgery (15%) or liver disease (13%). TRALI incidence was measured at 1 in 130,000 per issued product in QLD. Red cells were transfused in 32 cases, platelets in 18 and plasma products in 21, with 16 cases involving multiple products. Following laboratory assessment, 23% of cases had findings supportive of antibody mediated TRALI and 21% as likely non-antibody mediated. Possible TRALI was identified in 37.5% of cases of which 25% were antibody mediated and 12.5% non-antibody mediated. Nine (18.5%) cases were uncategorised due to insufficient immunologic investigations.DiscussionRates of TRALI incidence measured are lower than those seen in many international studies. A reduction in confirmed cases has been noted over recent years, supporting the implementation of risk-reduction strategies. We report a relatively higher proportion of non-antibody mediated TRALI and possible TRALI cases in more recent years, suggesting the need to further understand the role of product age and biological risk modifiers.
Project description:There is some evidence to suggest that chewing gum reduces chronic stress. However, it remains controversial how the taste and odour properties of chewing gum influence stress. The present study was designed to investigate this issue in human subjects. Using an enzyme-linked immunosorbent assay, we tested salivary cortisol concentration, which is thought to be a stress marker, in 96 adults who chewed gum with different combinations of taste and odour. Subjects could discriminate between the types of gum without prior information. Salivary cortisol concentrations were highest and lowest for the subjects who chewed the most flavourful gum and the least flavourful gum, respectively. These findings suggest that the salivary cortisol level during gum chewing is not a marker of negative emotions (i.e., stressful conditions) as traditionally considered but, rather, an index of positive emotions that can facilitate biological responses to overcome stressful conditions.
Project description:Visually induced motion sickness (VIMS) is a common side-effect of exposure to virtual reality (VR). Its unpleasant symptoms may limit the acceptance of VR technologies for training or clinical purposes. Mechanical stimulation of the mastoid and diverting attention to pleasant stimuli-like odors or music have been found to ameliorate VIMS. Chewing gum combines both in an easy-to-administer fashion and should thus be an effective countermeasure against VIMS. Our study investigated whether gustatory-motor stimulation by chewing gum leads to a reduction of VIMS symptoms. 77 subjects were assigned to three experimental groups (control, peppermint gum, and ginger gum) and completed a 15-min virtual helicopter flight, using a VR head-mounted display. Before and after VR exposure, we assessed VIMS with the Simulator Sickness Questionnaire (SSQ), and during the virtual flight once every minute with the Fast Motion Sickness Scale (FMS). Chewing gum (peppermint gum: M = 2.44, SD = 2.67; ginger gum: M = 2.57, SD = 3.30) reduced the peak FMS scores by 2.05 (SE = 0.76) points as compared with the control group (M = 4.56, SD = 3.52), p < 0.01, d = 0.65. Additionally, taste ratings correlated slightly negatively with both the SSQ and the peak FMS scores, suggesting that pleasant taste of the chewing gum is associated with less VIMS. Thus, chewing gum may be useful as an affordable, accepted, and easy-to-access way to mitigate VIMS in numerous applications like education or training. Possible mechanisms behind the effect are discussed.
Project description:BackgroundAlthough quantitative evidence is lacking, it is generally believed that the majority of cases of transfusion-related acute lung injury (TRALI) are caused by female blood donors. We aimed to examine the relation between female donors and the occurrence of TRALI.Study design and methodsWe performed an international, multicenter case-referent study. TRALI patients who were diagnosed clinically, independent of serology or donor sex, and had received transfusions either only from male donors or only from female donors (unisex cases) were selected. The observed sex distribution among the donors of these TRALI patients was compared to the expected sex distribution, based on the relevant donor populations.ResultsEighty-three clinical TRALI cases were included; 67 cases received only red blood cells (RBCs), 13 only plasma-rich products, and three both. Among RBC recipients the relative risk (RR) of TRALI after a transfusion from a female donor was 1.2 (95% confidence interval [CI], 0.69-2.1) and among plasma-rich product recipients the RR was 19 (95% CI, 1.9-191). The p value for the difference between RBCs and plasma was 0.023.ConclusionOur data support the notion that plasma from female donors is associated with an increased risk of TRALI, while RBCs from female donors are not.