The defining biology that distinguishes neutrophil extracellular traps (NETs) from other forms of cell death is unresolved, and techniques which unambiguously identify NETs remain elusive. Raman scattering measurement provides a holistic overview of cell molecular composition based on characteristic bond vibrations in components such as lipids and proteins. We collected Raman spectra from NETs and freeze/thaw necrotic cells using a custom built high-throughput platform which is able to rapidly measure spectra from single cells.
View Article and Find Full Text PDFAnti-neutrophil cytoplasmic Ab (ANCA)-associated vasculitis (AAV) is a life-threatening condition characterized by improper activation of neutrophils and the release of neutrophil extracellular traps (NETs) in small vessels. This study aimed to explain the role of NETs in AAV pathogenesis by investigating a link between adhesion and NET release using human neutrophils. We leveraged an imaging flow cytometry-based assay and three-dimensional culture to demonstrate that neutrophil adhesion is essential for ANCA-induced NET formation.
View Article and Find Full Text PDFHeparin is used extensively as an anticoagulant in a broad range of diseases and procedures; however, its biological effects are not limited to coagulation and remain incompletely understood. Heparin usage can lead to the life-threatening complication known as heparin-induced thrombocytopenia (HIT), caused by the development of antibodies against heparin/PF4 complexes. Here, we demonstrate the ability of heparin to induce neutrophil extracellular traps (NETs).
View Article and Find Full Text PDFInfluenza A virus (IAV) triggers the infected lung to produce IL-1 and recruit neutrophils. Unlike IL-1β, however, little is known about IL-1α in terms of its mechanism of induction, action and physiological relevance to the host immunity against IAV infection. In particular, whether Z-DNA-binding protein 1 (ZBP1), a key molecule for IAV-induced cell death, is involved in the IL-1α induction, neutrophil infiltration and the physiological outcome has not been elucidated.
View Article and Find Full Text PDFNeutrophil extracellular trap (NET) formation involves the release of DNA outside the cell to neutralize pathogens. Techniques such as live microscopy, flow cytometry, and intravital imaging allow the characterization of NETs, but these either cannot be applied in vivo, lack specificity or require invasive procedures. We developed an automated analysis method to rapidly acquire and characterize cells as NETs or NET precursors, as opposed to cells undergoing other forms of cell death, using imaging flow cytometry.
View Article and Find Full Text PDFThe mechanisms that determine patterns of species dispersal are important factors in the production and maintenance of biodiversity. Understanding these mechanisms helps to forecast the responses of species to environmental change. Here, we used a comparative framework and genomewide data obtained through RAD-Seq to compare the patterns of connectivity among breeding colonies for five penguin species with shared ancestry, overlapping distributions and differing ecological niches, allowing an examination of the intrinsic and extrinsic barriers governing dispersal patterns.
View Article and Find Full Text PDFThe malaria parasite hijacks host erythrocytes to shield itself from the immune system and proliferate. Red blood cell abnormalities can provide protection from malaria by impeding parasite invasion and growth within the cell or by compromising the ability of parasites to avoid host clearance. Here, we describe 2 -ethyl--nitrosourea-induced mouse lines, and , containing single-point mutations in the erythrocyte membrane skeleton gene, β spectrin (), which exhibit microcytosis but retain a relatively normal ratio of erythrocyte surface area to volume and are highly resistant to rodent malaria.
View Article and Find Full Text PDFExtracellular histones have been shown to play an important pathogenic role in many diseases, primarily through their cytotoxicity toward nucleated cells and their ability to promote platelet activation with resultant thrombosis and thrombocytopenia. In contrast, little is known about the effect of extracellular histones on erythrocyte function. We demonstrate in this study that histones promote erythrocyte aggregation, sedimentation, and using a novel in vitro shear stress model, we show that histones induce erythrocyte fragility and lysis in a concentration-dependent manner.
View Article and Find Full Text PDFAlthough malaria is a life-threatening disease with severe complications, most people develop partial immunity and suffer from mild symptoms. However, incomplete recovery from infection causes chronic illness, and little is known of the potential outcomes of this chronicity. We found that malaria causes bone loss and growth retardation as a result of chronic bone inflammation induced by products.
View Article and Find Full Text PDFGenetic defects in various red blood cell (RBC) cytoskeletal proteins have been long associated with changes in susceptibility towards malaria infection. In particular, while ankyrin (Ank-1) mutations account for approximately 50% of hereditary spherocytosis (HS) cases, an association with malaria is not well-established, and conflicting evidence has been reported. We describe a novel N-ethyl-N-nitrosourea (ENU)-induced ankyrin mutation MRI61689 that gives rise to two different ankyrin transcripts: one with an introduced splice acceptor site resulting a frameshift, the other with a skipped exon.
View Article and Find Full Text PDFBackground: Major, long-term environmental changes are projected in the Southern Ocean and these are likely to have impacts for marine predators such as the Adélie penguin (Pygoscelis adeliae). Decadal monitoring studies have provided insight into the short-term environmental sensitivities of Adélie penguin populations, particularly to sea ice changes. However, given the long-term nature of projected climate change, it is also prudent to consider the responses of populations to environmental change over longer time scales.
View Article and Find Full Text PDFThe treatment of iron deficiency in areas of high malaria transmission is complicated by evidence which suggests that iron deficiency anemia protects against malaria, while iron supplementation increases malaria risk. Iron deficiency anemia results in an array of pathologies, including reduced systemic iron bioavailability and abnormal erythrocyte physiology; however, the mechanisms by which these pathologies influence malaria infection are not well defined. In the present study, the response to malaria infection was examined in a mutant mouse line, Tfrc(MRI24910), identified during an N-ethyl-N-nitrosourea (ENU) screen.
View Article and Find Full Text PDFAs parasites, Plasmodium species depend upon their host for survival. During the blood stage of their life-cycle parasites invade and reside within erythrocytes, commandeering host proteins and resources towards their own ends, and dramatically transforming the host cell. Parasites aptly avoid immune detection by minimizing the exposure of parasite proteins and removing themselves from circulation through cytoadherence.
View Article and Find Full Text PDFDuring blood stage infection, malaria parasites invade, mature, and replicate within red blood cells (RBCs). This results in a regular growth cycle and an exponential increase in the proportion of malaria infected RBCs, known as parasitemia. We describe a flow cytometry based protocol which utilizes a combination of the DNA dye Hoechst, and the mitochondrial membrane potential dye, JC-1, to identify RBCs which contain parasites and therefore the parasitemia, of in vivo blood samples from Plasmodium chabaudi adami DS infected mice.
View Article and Find Full Text PDFBackground: Malaria treatments are becoming less effective due to the rapid spread of drug resistant parasites. Increased understanding of the host/parasite interaction is crucial in order to develop treatments that will be less prone to resistance. Parasite invasion of the red blood cell (RBC) is a critical aspect of the parasite life cycle and is, therefore, a promising target for the development of malaria treatments.
View Article and Find Full Text PDFBackground: The EU currently lacks reliable data on the prevalence and incidence of mental disorders in older people. Despite the availability of several national and international epidemiological studies, the size and burden of mental disorders in the elderly remain unclear due to various reasons. Therefore, the aims of the MentDis_ICF65+ study are (1) to adapt existing assessment instruments, and (2) to collect data on the prevalence, the incidence, and the natural course and prognosis of mental disorders in the elderly.
View Article and Find Full Text PDFSoc Psychiatry Psychiatr Epidemiol
April 2013
Purpose: Partial or non-adherence is common in people taking antipsychotic medication. A good therapeutic alliance is thought by psychiatrists to encourage engagement with a service and improve adherence. This paper aims to examine how psychiatrists and patients communicate in outpatient consultations about partial or non-adherence to antipsychotic prescribing.
View Article and Find Full Text PDFThe professional identity of psychiatry depends on it being regarded as one amongst many medical specialties and sharing ideals of good practice with other specialties, an important marker of which is the achievement of shared decision-making and avoiding a reputation for being purely agents of social control. Yet the interactions involved in trying to achieve shared decision-making are relatively unexplored in psychiatry. This study analyses audiotapes of 92 outpatient consultations involving nine consultant psychiatrists focusing on how pressure is applied in shared decisions about antipsychotic medication.
View Article and Find Full Text PDFOver the past ten years, the National Health Service in England has introduced home treatment teams throughout the country. Despite this, and the fact that England now has the fourth lowest number of beds per capita in Europe, no mental health service has been able to dispense with acute admission beds altogether. One unintended consequence of new investment in community alternatives to inpatient care is that the threshold for admission has risen and acute wards now accommodate a patient group that is more severe with regard to levels of disturbance and social disadvantage.
View Article and Find Full Text PDFMental illness is now the leading cause of both sickness absence and incapacity benefits in most high-income countries. The rising economic and social costs make health and work an increasing priority for policy makers. We discuss the findings from Dame Carol Black's recent review of the health of Britain's working-age population and examine how her recommendations may impact and challenge mental health services.
View Article and Find Full Text PDFBackground: Expert clinical judgement combines technical proficiency with humanistic qualities.
Aims: To test the psychometric properties of questionnaires to assess the humanistic qualities of working with colleagues and relating to patients using multisource feedback.
Method: Analysis of self-ratings by 347 consultant psychiatrists and ratings by 4422 colleagues and 6657 patients.
Background: In England, rates of involuntary admissions increased in subgroups of patients. It is unknown whether this is true in other European countries.
Aims: To establish whether the increase in emergency commitments was uniform across subgroups of patients and dangerousness criteria used to justify commitment in The Netherlands.