368 research outputs found
Dendritic cell-mediated HIV-1 transmission to T cells of LAD-1 patients is impaired due to the defect in LFA-1
BACKGROUND: Dendritic cells (DC) have been proposed to mediate sexual HIV-1 transmission by capturing the virus in the mucosa and subsequently presenting it to CD4(+ )T cells. We have demonstrated before that DC subsets expressing higher levels of intercellular adhesion molecule-1 (ICAM-1) are better HIV-1 transmitters. ICAM-1 binds leukocyte function-associated molecule-1 (LFA-1) on T cells, an integrin responsible for adhesion and signaling at the immunological synapse. To corroborate the importance of the ICAM-1— LFA-1 interaction, we performed transmission experiments to LFA-1 negative leukocytes from Leukocyte Adhesion Deficiency type 1 (LAD-1) patients. RESULTS: We clearly show that DC-mediated HIV-1 transmission to LAD-1 T cells is impaired in comparison to healthy controls. Furthermore, HIV-1 transmission to T cells from a unique LAD-1 patient with a well characterized LFA-1 activation defect was impaired as well, demonstrating that activation of LFA-1 is crucial for efficient transmission. Decreased cell adhesion between DC and LAD-1 T cells could also be illustrated by significantly smaller DC-T cell clusters after HIV-1 transmission. CONCLUSION: By making use of LFA-1 defect cells from unique patients, this study provides more insight into the mechanism of HIV-1 transmission by DC. This may offer new treatment options to reduce sexual transmission of HIV-1
How to improve newly qualified midwives' transition-into-practice:A Delphi study
BACKGROUND: In the Netherlands, newly qualified midwives start work as registered midwives without any formal transition support. Research shows that newly qualified midwives do not feel sufficiently confident and competent in their work during the period following graduation. This could impact the quality of care provided by newly registered midwives. The aim of this study is to seek consensus with stakeholders concerning viable components of support for newly qualified midwives working in midwifery care in the Netherlands.METHODS: A Delphi study was conducted among maternity care stakeholders in the Netherlands. During two rounds, sixteen statements derived from a theoretical framework of organizational socialization theory and previous studies were assessed (round 1, n = 56; round 2, n = 52). Stakeholders (N = 61) were invited and completed an online questionnaire that included spaces for opinions and remarks.RESULTS: Stakeholders agreed about an introductory support period for newly qualified midwives, involving performance feedback and regional-level backup from fellow midwives during shifts. They further agreed on the responsibilities of established professionals that they should support newcomers in practice and provide mentoring or group coaching, although they face organizational barriers for supporting newcomers.CONCLUSIONS: Stakeholders found consensus upon several components of support at the workplace. In addition, a stable work environment seemed less important in their opinion while previous research suggests otherwise. Practice organisations need to improve the employment conditions and support for newly qualified midwives to ensure the quality of midwifery care is guaranteed.</p
The initiation of Dutch newly qualified hospital-based midwives in practice, a qualitative study
In the Netherlands, a percentage of newly qualified midwives start work in maternity care as a hospital-based midwife, although prepared particularly for working autonomously in the community. Aim: This study aimed to explore newly qualified Dutch midwives' perceptions of their job demands and resources during their initiation to hospital-based practice. Design: We conducted a qualitative study with semi structured interviews using the Job Demands-Resources model as theoretical framework. Methods: Twenty-one newly qualified midwives working as hospital-based midwives in the Netherlands were interviewed individually between January and July 2018. Transcripts were analyzed using thematic content analysis. Findings: High workload, becoming a team member, learning additional medical procedures and job insecurity were perceived demands. Participants experienced the variety of the work, the teamwork, social support, working with women, and employment conditions as job resources. Openness for new experiences, sociability, calmness and accuracy were experienced as personal resources, and perfectionism, self-criticism, and fear of failure as personal demands. Conclusion: Initiation to hospital-based practice requires from newly qualified midwives adaptation to new tasks: working with women in medium and high-risk care, managing tasks, as well as often receiving training in additional medical skills. Sociability helps newly qualified midwives in becoming a member of a multidisciplinary team; neuroticism and perfectionism hinders them in their work. Clear expectations and a settling-in period may help newly qualified midwives to adapt to practice. The initiation phase could be better supported by preparing student midwives for working in a hospital setting and helping manage expectations about the settling-in period
Dendritic cells internalize staphylococcus aureus more efficiently than staphylococcus epidermidis, but do not differ in induction of antigen-specific t cell proliferation
Staphylococcus aureus and Staphylococcus epidermidis are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation of anti-staphylococcal T cell responses. Therefore, we aimed to compare the ability of S. aureus and S. epidermidis to influence the essential steps in human DC activation and subsequent antigen-specific CD4+ T cell proliferation, and to investigate the underlying mechanisms. Using multiple strains of both species, we observed that S. aureus was internalized more effectively than S. epidermidis by DCs but that both species were equally potent in activating these host cells, as evidenced by similar induction of DC maturation marker expression and antigen loading onto MHC-II molecules. The DCs stimulated by S. aureus strains not harboring superantigen (SAg) genes or by any of the S. epidermidis strains, induced low, likely physiological levels of T cell proliferation. Only DCs stimulated with S. aureus strains harboring SAg genes induced high levels of T cell proliferation. Taken together, S. aureus and S. epidermidis do not differently affect DC activation and ensuing antigen-specific T cell proliferation, unless a strain has the capacity to produce SAgs
Determinants of use of care provided by complementary and alternative health care practitioners to pregnant women in primary midwifery care:A prospective cohort study
Background: Pregnant women visit complementary/alternative health care practitioners in addition to regular maternal health care practitioners. A wide variation has been reported with regard to rates and determinants of use of complementary/alternative medicine (CAM), which may be due to heterogeneous populations. The aim of this study was to examine the prevalence and determinants of use of CAM practitioners by a homogeneous population of low-risk pregnant women in the Netherlands. Methods: Data from the population-based DELIVER study was used, concerning 1500 clients from twenty midwifery practices across the Netherlands in 2009 and 2010. CAM use was measured based on patient reports. Potential determinants were derived from Andersen's behavioural model of health care utilization. Results: The prevalence of CAM practitioner use by low-risk pregnant women was 9.4 %. Women were more likely to use CAM if they had supplementary health care insurance (OR 3.11; CI 1.41-6.85), rated their health as 'bad/fair' (OR 2.63; CI 1.65-4.21), reported a chronic illness or handicap (OR 1.93; CI 1.14-3.27), smoked during pregnancy (OR 1.88; CI 1.06-3.33), or used alcohol during pregnancy (OR 2.30; CI 1.46-3.63). Conclusions: CAM is relatively frequently used by low-risk pregnant women. Determinants revealed in this study diverge from other studies using heterogeneous populations. Maternal health care practitioners must be aware of CAM use by low-risk pregnant women and incorporate this knowledge into daily practice by actively discussing this subject with pregnant women
Is disturbed clearance of apoptotic keratinocytes responsible for UVB-induced inflammatory skin lesions in systemic lupus erythematosus?
Apoptotic cells are thought to play an essential role in the pathogenesis of systemic lupus erythematosus (SLE). We hypothesise that delayed or altered clearance of apoptotic cells after UV irradiation will lead to inflammation in the skin of SLE patients. Fifteen SLE patients and 13 controls were irradiated with two minimal erythemal doses (MEDs) of ultraviolet B light (UVB). Subsequently, skin biopsies were analysed (immuno)histologically, over 10 days, for numbers of apoptotic cells, T cells, macrophages, and deposition of immunoglobulin and complement. Additionally, to compare results with cutaneous lesions of SLE patients, 20 biopsies of lupus erythematosus (LE) skin lesions were analysed morphologically for apoptotic cells and infiltrate. Clearance rate of apoptotic cells after irradiation did not differ between patients and controls. Influx of macrophages in dermal and epidermal layers was significantly increased in patients compared with controls. Five out of 15 patients developed a dermal infiltrate that was associated with increased epidermal influx of T cells and macrophages but not with numbers of apoptotic cells or epidermal deposition of immunoglobulins. Macrophages were ingesting multiple apoptotic bodies. Inflammatory lesions in these patients were localised near accumulations of apoptotic keratinocytes similar as was seen in the majority of LE skin lesions. In vivo clearance rate of apoptotic cells is comparable between SLE patients and controls. However, the presence of inflammatory lesions in the vicinity of apoptotic cells, as observed both in UVB-induced and in LE skin lesions in SLE patients, suggests that these lesions result from an inflammatory clearance of apoptotic cells
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