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IgG fractions from patients with antiphospholipid syndrome and systemic lupus erythematosus bind to platelets, but do not affect collagen-induced platelet activation
No full textAnti-beta-2 glycoprotein 1 (anti-β2GP1) is an antiphospholipid antibody found in patients with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). Its presence commonly is associated with thrombosis; however, the mechanisms of interaction of anti-β2GP1 antibodies and platelets remain unclear. We investigated the effects of APS and SLE patient-derived IgG fractions on collagen-mediated platelet aggregation and examined the binding of patient-derived IgG to platelets before and after activation by collagen. IgG fractions, 150, 200, 300 or 350 µg/ml, isolated from 11 patients with APS and SLE were incubated with two sets of platelet-rich plasma (PRP) in the incubation wells of an aggregometer. The first set was activated by collagen and the other set was incubated for an additional 10 min. All platelets were collected by centrifugation and fixed in cell blocks. We assessed binding of IgG to platelets using immunocytochemistry (ICC). Patient-derived IgG fractions did not affect collagen-induced platelet aggregation. ICC staining using anti-human IgG antibodies demonstrated that patient-derived IgG fractions had greater affinity for non-activated platelets than those activated by 0.75 µg/ml collagen. Patient-derived IgG fractions bound to the surface of platelets and potentially could be internalized by platelets. IgG fractions from APS and SLE patients may sensitize non-activated platelets, which could increase platelet reactivity and thrombotic risk in patients. We did not detect secondary effects of patient-derived IgG fractions
Dispersal of hydrogen in the retina — A three-layer model
No full textTwo simple mathematical models of advection and diffusion of hydrogen within the retina are discussed. The work is motivated by the hydrogen clearance technique, which is used to estimate blood flow in the retina. The first model assumes that the retina consists of three, well-mixed layers with different thickness, and the second is a two-dimensional model consisting of three regions that represent the layers in the retina. Diffusion between the layers and leakage through the outer edges are considered. Solutions to the governing equations are obtained by employing Fourier series and finite difference methods for the two models, respectively. The effect of important parameters on the hydrogen concentration is examined and discussed. The results contribute to understanding the dispersal of hydrogen in the retina and in particular the effect of flow in the vascular retina. It is shown that the predominant features of the process are captured by the simpler model
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: A review
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Negative potassium (K) balances on farmlands globally are widespread because fertiliser K input is often less than losses (leaching) and removal of K in hay, straw and grain, which leads to a rundown of plant-available K. When soil K reserves are not large and the plant-available K pools are not well buffered, the risk of K rundown in soils is high. In the south-west of Western Australia, soil K rundown, particularly by continuous cropping or in systems where a large portion of crop biomass is removed, is increasing the prevalence of crop K deficiency even on soils where K was not previously a limiting factor for crop yields. While fertiliser K is required for adequate supply of plant-available K, maximising K use efficiency is also important for cropping profitability and sustainability in dryland agriculture. Plant K uptake and use efficiency can be affected by soil types, crop species and sequences, seasonal conditions, and K management. In water-limited environments, crop K nutrition, especially root access to subsoil K, plays a crucial role in promoting root growth, regulating plant water relations and alleviating biotic and abiotic stresses. Optimised use of both soil and fertiliser K is increasingly necessary to sustain crop yields under stressed conditions in the context of K rundown in soils
Pressure pain thresholds in a real-world chiropractic setting: Topography, changes after treatment, and clinical relevance?
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Changes in pain sensitivity are a commonly suggested mechanism for the clinical effect of spinal manipulative therapy (SMT). Most research has examined pressure pain thresholds (PPT) and has primarily been conducted in controlled experimental setups and on asymptomatic populations. Many important factors are likely to differ between research and clinical settings, which may affect PPT changes following SMT. Therefore, we planned to investigate PPT before and after clinical chiropractic care and investigate relationships with various potentially clinically-relevant factors.
Methods
We recruited participants from four Danish chiropractic clinics between May and August 2021. A total of 129 participants (72% of the invited) were included. We measured PPT at eight pre-determined test sites (six spinal and two extra-spinal) immediately before (pre-session) and immediately after (post-session) the chiropractic consultation.
We used regression analyses to investigate PPT changes, including the following factors: (i) vertebral distance to the nearest SMT site, (ii) rapid clinical response, (iii) baseline PPT, (iv) number of SMTs performed, (v) at the region of clinical pain compared to other regions, and (vi) if other non-SMT treatment was provided. We also performed topographic mapping of pre-session PPTs.
Results
After the consultation, there was a non-significant mean increase in PPT of 0.14 kg (95% CIs = − 0.01 to 0.29 kg). No significant associations were found with the distance between the PPT test site and nearest SMT site, the clinical response of participants to treatment, the pre-session PPT, the total number of SMTs performed, or the region/s of clinical pain. A small increase was observed if myofascial treatment was also provided. Topographic mapping found greater pre-session PPTs in a caudal direction, not affected by the region/s of clinical pain.
Conclusions
This study of real-world chiropractic patients failed to demonstrate a substantial local or generalized increase in PPT following a clinical encounter that included SMT. This runs counter to prior laboratory research and questions the generalizability of highly experimental setups investigating the effect of SMT on PPT to clinical practice
Asymmetry of the pupillary light reflex during a cold pressor test
No full textPupillary light reflexes were monitored in 20 healthy participants while they immersed one foot in painfully cold water (the cold pressor test) or in warm water for 1 min. Pupillary dilatation was greater during the cold pressor test than during the warm-water immersion. In addition, during the cold pressor test, re-dilation after exposure to bright light proceeded more rapidly for the ipsilateral than contralateral pupil. These findings suggest that sympathetic pupillary drive is greater ipsilateral than contralateral to pain
A new genus of Australian orb-weaving spider with extreme sexual size dimorphism (Araneae, Araneidae)
No full textThe new Australian orb-weaving spider genus Mangrovia in the family Araneidae Clerck, 1757 is described. It is characterised by extreme sexual size-dimorphism (eSSD) with females (total length 8–10 mm) ca. 3 to 5 times larger than males (2.5–3 mm). Whilst Mangrovia shares with the informal Australian ‘backobourkiine’ clade a single seta on the male pedipalp patella, the genus is probably more closely related to the ‘zealaraneines’ or associated genera. In addition to eSSD and the single patellar spine, the genus is characterised by a distinct subterminal embolus branch in males. The new genus includes two species: the type species Mangrovia albida (L. Koch, 1871) comb. nov. (= Epeira fastidiosa Keyserling, 1887, new syn.) from Queensland and Mangrovia occidentalis sp. nov. from Western Australia. Both species are apparently coastal and occur in mangroves, but also in riparian woodland. Spiders were found resting in rolled-up leaves adjacent to their orb-web
Genetic variation in CaTIFY4b contributes to drought adaptation in chickpea
Get PDFChickpea production is vulnerable to drought stress. Identifying the genetic components underlying drought adaptation is crucial for enhancing chickpea productivity. Here, we present the fine mapping and characterization of ‘QTL-hotspot’, a genomic region controlling chickpea growth with positive consequences on crop production under drought. We report that a non-synonymous substitution in the transcription factor CaTIFY4b regulates seed weight and organ size in chickpea. Ectopic expression of CaTIFY4b in Medicago truncatula enhances root growth under water deficit. Our results suggest that allelic variation in ‘QTL-hotspot’ improves pre-anthesis water use, transpiration efficiency, root architecture and canopy development, enabling high-yield performance under terminal drought conditions. Gene expression analysis indicated that CaTIFY4b may regulate organ size under water deficit by modulating the expression of GRF-INTERACTING FACTOR1 (GIF1), a transcriptional co-activator of Growth-Regulating Factors. Taken together, our study offers new insights into the role of CaTIFY4b and on diverse physiological and molecular mechanisms underpinning chickpea growth and production under specific drought scenarios
The sea urchin Centrostephanus tenuispinus (Clark, 1914) is an important bio-eroder on a high latitude (32° S) coral reef
No full textSea urchins are keystone herbivores in many marine benthic habitats and can significantly influence coral-algae phase shifts and reef carbonate budgets. Hall Bank Reef in Western Australia is a unique high latitude reef with high hermatypic coral cover but lacking macroalgae and soft corals. Since the reef status is thought to result from grazing of the urchin Centrostephanus tenuispinus, this study was focused on evaluating bio-erosion by C. tenuispinus with respect to size structure and seasonality. Monthly samples of urchins were collected during 2014–2016 and gut composition was analysed. Gut evacuation rates were calculated using urchins dissected at time intervals up to 96 h. Reworked CaCO3 was calculated using caged urchins in a nearby seagrass bed. Mean percentages of organic, CaCO3, and siliceous components in C. tenuispinus gut contents were 86.3 ± 3.2, 10.3 ± 2.8, and 3.4 ± 1.5%, respectively. Gut evacuation rates for autumn, winter, spring, and summer were 0.70, 0.24, 0.48, and 0.72 day −1. Bio-erosion rates were significantly higher in summer (3.5 g CaCO3 m−2 day−1) than in winter (1.3 g CaCO3 m−2 day−1) and higher rates recorded for large urchins. Urchin bio-erosion was 1 kg CaCO3 m−2 annum−1. Variation in food ingestion rates in response to seawater temperature changes was found to be the main driver for differences in seasonal bio-erosion rates, which likely contribute to the absence of macroalgae and the maintenance of high coral cover on Hall Bank Reef. This study provides baseline data on bio-erosion by a sea urchin at Hall Bank Reef, which will be essential in monitoring and managing reefs in this region, especially under current trends in climate change
Fatal disseminated toxoplasmosis in a feline immunodeficiency virus‐positive cat receiving oclacitinib for feline atopic skin syndrome
Get PDFToxoplasma gondii is a ubiquitous protozoan, for which felids are the definitive host. Immunocompromised individuals are susceptible to recrudescent toxoplasmosis. This case describes a 6-year-old, feline immunodeficiency virus-positive domestic short hair cat with feline atopic skin syndrome that developed fatal toxoplasmosis after treatment with oclacitinib for five months