Unseen, unheard: a qualitative analysis of women's experiences of exclusively expressing breast milk.

BACKGROUND: Breast milk feeding has numerous benefits for women and infants. Positive maternal experiences with breast milk feeding impacts exclusivity, duration, and maternal mental health. Most research focuses on women feeding directly at the breast. Some women elect to feed exclusively expressed milk to their healthy, term infants rather than feed directly at the breast. Little is known about what constitutes a positive experience among this population. Therefore, the aim of this study was to explore women's experiences of exclusive expression (EE). METHODS: Interviews were conducted via Microsoft Teams to collect qualitative data from a purposive sample of 21 women practicing EE. Interviews were analyzed for themes. RESULTS: Three themes: Unseen and Unheard, Doing it My Way, and Getting into the Groove, and 8 subthemes: Breast is Best, Missed Opportunities for Healthcare Provider Support, Fighting for it, What Works for Us, A Sense of Control, Preparation, Tricks of the Trade, and Making it Manageable were identified. Despite challenges, including a lack of support from healthcare providers and a lack of acknowledgement as breastfeeding mothers, exclusive expression offered participants a method to continue breast milk feeding in a way that they found to be satisfying. CONCLUSION: This study provides insight into experiences of exclusive expression that clinicians can use to improve their support of breast milk feeding during perinatal encounters. Societal pressure to feed from the breast may have negative emotional consequences for women electing to exclusively express. There is a need for more information and support for breast milk expression from healthcare providers along with a reframing of how breast milk feeding is discussed and promoted.

Nurse practitioner led model of after-hours emergency care in an Australian rural urgent care Centre: health service stakeholder perceptions.

BACKGROUND: The challenges of providing and accessing quality health care in rural regions have long been identified. Innovative solutions are not only required but are also vital if effective, timely and equitable access to sustainable health care in rural communities is to be realised. Despite trial implementation of some alternative models of health care delivery, not all have been evaluated and their impacts are not well understood. The aim of this study was to explore the views of staff and stakeholders of a rural health service in relation to the implementation of an after-hours nurse practitioner model of health care delivery in its Urgent Care Centre. METHODS: This qualitative study included semi-structured individual and group interviews with professional stakeholders of a rural health service in Victoria, Australia and included hospital managers and hospital staff who worked directly or indirectly with the after-hours NPs in addition to local GPs, GP practice nurses, and paramedics. Thematic analysis was used to generate key themes from the data. RESULTS: Four themes emerged from the data analysis: transition to change; acceptance of the after-hours nurse practitioner role; workforce sustainability; and rural context. CONCLUSIONS: This study suggests that the nurse practitioner-led model is valued by rural health practitioners and could reduce the burden of excessive after-hour on-call duties for rural GPs while improving access to quality health care for community members. As pressure on rural urgent care centres further intensifies with the presence of the COVID-19 pandemic, serious consideration of the nurse practitioner-led model is recommended as a desirable and effective alternative.

Laboratory Analysis Techniques for the Perinatal Microbiome: Implications for Studies of Probiotic Interventions.

The microbiome is composed of many organisms and is impacted by an intricate exchange between genetics and environmental factors. The perinatal microbiome influences both the developing fetus and the pregnant person. The purpose of this article is to describe the tests that are currently available for laboratory analysis of the perinatal microbiome in relationship to probiotic interventions. This article focuses on the bacterial component of the microbiome. Although adverse outcomes associated with the perinatal microbiome have been studied, a comprehensive understanding of the physiologic perinatal microbiome is still emerging. Early efforts to influence the perinatal microbiome through probiotics are currently under investigation. Unique terminology is defined, and the microbial composition of perinatal microbiota is summarized. The outcomes of studies of antenatal probiotics are summarized. Microbiome testing and analysis are defined and compared. Implications for perinatal care and probiotics research are presented.

Interpreting Meaningful Change in the Distance Walked in the 10-Metre ISWT in Cardiac Rehabilitation.

BACKGROUND: The interpretability of change in exercise test scores is an important measurement property. This study aimed to provide a framework for the interpretation of individual change scores of the 10metre incremental shuttle walk test (ISWT) in cardiac rehabilitation. METHODS: In a quantitative pre-post design study, 52 patients who were referred to a hospital outpatient department for cardiac rehabilitation participated in this study. Participants completed two ISWTs prior to cardiac rehabilitation. Post cardiac rehabilitation, participants completed a global rating of change score and two ISWTs. Change scores were analysed for smallest detectable change (SDC) and minimum important change (MIC). RESULTS: The SDC for an individual was 47 metres. The predicted MIC for participants to report an improvement ranged from 70 to 92 metres. The predicted MIC for participants who did not report a deterioration in the global rating of change (i.e., those who reported unchanged or improved) ranged from 16 to 42 metres. CONCLUSIONS: The MIC for patients who report any improvement in physical fitness and functional capacity is 70 metres. These results suggest that over an 8-week program, patients would need to improve by at least seven shuttles to perceive an improvement in their physical fitness and functional capacity. Patients with small increases in the 10-metre ISWT distance may still report deterioration in their physical fitness and functional capacity.

Through the Microbial Looking Glass: Premature Labor, Preeclampsia, and Gestational Diabetes: A Scoping Review.

The influence of microbial factors on adverse perinatal outcomes has become the focal point of recent investigations, with particular interest in the role of the microbiome and probiotic interventions. The purpose of this scoping review was to identify and critique the most recent evidence about these factors as they relate to pregnancies complicated by preeclampsia (PEC), preterm birth (PTB), and gestational diabetes mellitus (GDM). Four databases (PubMed, EMBASE, Web of Science, and Cochrane) were searched for articles published in English in the last 10 years with the concepts of the microbiome, probiotics, and PEC, PTB, or GDM. Forty-nine articles were eligible for full-text review. Five articles were excluded, leaving 44 articles that met all the eligibility criteria. The relationships between the microbiome and the risk for PEC, PTB, and GDM are not fully elucidated, although probiotic interventions seem beneficial in decreasing PEC and GDM risk. Probiotic interventions targeting bacterial vaginosis and elimination of infection in women at risk for PTB appear to be beneficial. More research is needed to understand the contributions of the microbiome to adverse perinatal outcomes. Probiotic interventions appear to be effective in reducing risk for select outcomes.

Effectiveness of CenteringPregnancy on Breastfeeding Initiation Among African Americans: A Systematic Review and Meta-analysis.

While breastfeeding initiation rates for African American mothers are low, an innovative model of group prenatal care, CenteringPregnancy, holds promise to increase breastfeeding rates. The aim of this systematic review and meta-analysis was to examine the effects of CenteringPregnancy versus individual prenatal care on breastfeeding initiation among African American mothers. Using a systematic approach and PRISMA guidelines, 4 electronic databases were used to search the literature. English-language studies, comparing CenteringPregnancy and individual prenatal care, including African American participants, and specifying breastfeeding initiation as an outcome were screened for inclusion. Study strength and quality were assessed and 7 studies were systematically reviewed and meta-analyzed. Participation in CenteringPregnancy increased the probability of breastfeeding initiation by 53% (95% confidence interval = 29%-81%) (n = 8047). A subgroup analysis of breastfeeding initiation among only African American participants was performed on 4 studies where data were available. Participation in CenteringPregnancy increased the probability of breastfeeding initiation by 71% (95% confidence interval = 27%-131%) (n = 1458) for African American participants. CenteringPregnancy is an effective intervention to increase breastfeeding initiation for participants, especially for African Americans. To close the racial gap in breastfeeding initiation, high-quality research providing specific outcomes for African American participants in CenteringPregnancy are needed.

Perforin Expression by CD8 T Cells Is Sufficient To Cause Fatal Brain Edema during Experimental Cerebral Malaria.

Human cerebral malaria (HCM) is a serious complication of Plasmodium falciparum infection. The most severe outcomes for patients include coma, permanent neurological deficits, and death. Recently, a large-scale magnetic resonance imaging (MRI) study in humans identified brain swelling as the most prominent predictor of fatal HCM. Therefore, in this study, we sought to define the mechanism controlling brain edema through the use of the murine experimental cerebral malaria (ECM) model. Specifically, we investigated the ability of CD8 T cells to initiate brain edema during ECM. We determined that areas of blood-brain barrier (BBB) permeability colocalized with a reduction of the cerebral endothelial cell tight-junction proteins claudin-5 and occludin. Furthermore, through small-animal MRI, we analyzed edema and vascular leakage. Using gadolinium-enhanced T1-weighted MRI, we determined that vascular permeability is not homogeneous but rather confined to specific regions of the brain. Our findings show that BBB permeability was localized within the brainstem, olfactory bulb, and lateral ventricle. Concurrently with the initiation of vascular permeability, T2-weighted MRI revealed edema and brain swelling. Importantly, ablation of the cytolytic effector molecule perforin fully protected against vascular permeability and edema. Furthermore, perforin production specifically by CD8 T cells was required to cause fatal edema during ECM. We propose that CD8 T cells initiate BBB breakdown through perforin-mediated disruption of tight junctions. In turn, leakage from the vasculature into the parenchyma causes brain swelling and edema. This results in a breakdown of homeostatic maintenance that likely contributes to ECM pathology.

CD8 T cell-initiated blood-brain barrier disruption is independent of neutrophil support.

Blood-brain barrier (BBB) disruption is a common feature of numerous neurologic disorders. A fundamental question in these diseases is the extent inflammatory immune cells contribute to CNS vascular permeability. We have previously shown that CD8 T cells play a critical role in initiating BBB disruption in the peptide-induced fatal syndrome model developed by our laboratory. However, myelomonocytic cells such as neutrophils have also been implicated in promoting CNS vascular permeability and functional deficit in murine models of neuroinflammatory disease. For this reason, we evaluated neutrophil depletion in a murine model of CD8 T cell-initiated BBB disruption by employing traditionally used anti-granulocyte receptor-1 mAb RB6-8C5 and Ly-6G-specific mAb 1A8. We report that CNS-infiltrating antiviral CD8 T cells express high levels of granulocyte receptor-1 protein and are depleted by treatment with RB6-8C5. Mice treated with RB6-8C5, but not 1A8, display: 1) intact BBB tight junction proteins; 2) reduced CNS vascular permeability visible by gadolinium-enhanced T1-weighted magnetic resonance imaging; and 3) preservation of motor function. These studies demonstrate that traditional methods of neutrophil depletion with RB6-8C5 are broadly immune ablating. Our data also provide evidence that CD8 T cells initiate disruption of BBB tight junction proteins and CNS vascular permeability in the absence of neutrophil support.

Labor down or bear down: a strategy to translate second-stage labor evidence to perinatal practice.

Scientific evidence supports spontaneous physiologic approaches to second-stage labor care; however, most women in US hospitals continue to receive direction from nurses and birth attendants to use prolonged Valsalva bearing-down efforts as soon as the cervix is completely dilated. Delaying maternal bearing-down efforts during second-stage labor until a woman feels an urge to push (laboring down) results in optimal use of maternal energy, has no detrimental maternal effects, and results in improved fetal oxygenation. Although most commonly used with women who are undergoing epidural anesthesia, laboring down is just one component of physiologic second-stage labor care that can be used to achieve optimal maternal and neonatal outcomes for women with or without an epidural. Prior efforts to translate evidence regarding second-stage labor care to practice have not been successful. In this article, the scientific evidence for second-stage labor care and previous efforts at clinical translation are reviewed. The Ottawa Hospital Second Stage Protocol is presented as a model with potential to allow translation of evidence to practice. Recommendations to enhance widespread adoption of evidence-based practice are provided, including improved collaboration between nurses and birth attendants.

Vaginal and Rectal microbiome changes following administration of a multi-species antenatal probiotic: A randomized control trial.

The gut and vaginal microbiome undergo changes during pregnancy which may be protective or harmful to the birthing person. Probiotics have been found to cause protective changes to the gut and vaginal microbiomes, with the potential to improve perinatal outcomes. This randomized control trial compares the vaginal and rectal microbiomes before and after an antenatal probiotic or placebo intervention, with a diverse group of pregnant people and a special focus on racial disparities. The vaginal and rectal microbiomes reveal non-significant increased Lactobacillus in the probiotics group, with a greater increase in participants who identified as Black. Potential implications and future study are discussed.

Participant Personal Characteristics and Adherence to Oral Capsules: A Secondary Analysis of a Randomized Placebo-Controlled Trial of Antenatal Probiotics.

BACKGROUND: Adherence to study interventions is critical to the conduct of randomized controlled trials (RCTs). The relationships between participant characteristics and intervention adherence are understudied in pregnant populations. The purpose of this study was to conduct a secondary analysis of adherence to study capsules in a double-masked, placebo-controlled RCT of a probiotic intervention to reduce antenatal Group B Streptococcus colonization, in relationship to participant characteristics. METHODS: We analyzed the relationship between capsule adherence rates and demographic characteristics among 81 RCT participants. Categorical variables were reported using counts and percentages, and continuous variables were expressed as means along with their standard deviations. For the univariate analyses, we compared demographic variables with adherence scores. A multivariate linear regression model was used to identify predictors of adherence. RESULTS: Average adherence was similar for control and probiotic group participants (P = .86) Univariate analysis showed that average adherence increased directly with age, education, and income. Participants who were partnered or living with others had higher average adherence compared with those who were single and living alone. Asian and White participants had the highest and Black participants had the lowest average, and there was no difference based on Hispanic ethnicity. Adjusting for all the variables in the regression, participants who identified as Black were significantly less likely to adhere to capsules than White participants, and those who were married or living with partners were more likely to adhere than the single participants. DISCUSSION: Diverse participants are critically important to RCTs. This secondary analysis provides evidence that participant characteristics and the social determinants of health play an important role in adherence to self-administered interventions in RCTs, although more research is needed. Our findings suggest that intentional consideration of RCT participant characteristics may allow for the development and tailoring of strategies to enhance intervention adherence. The study was registered on ClinicalTrials.gov (NCT03696953) on January 10, 2018.

The effect of manual therapy on ankle dorsiflexion range of motion: A pilot crossover randomized trial.

INTRODUCTION: Restricted ankle dorsiflexion is common after lower limb injury. The aim of this pilot study was to investigate the effect of passive ankle joint mobilization and calf muscle massage on ankle dorsiflexion range of motion in adults with residual restricted dorsiflexion. The secondary aim was to assess the methodology of the pilot study to inform a larger clinical trial. METHOD: The study design was a randomized crossover trial with assessor blinding. Twenty-five healthy participants with a history of lower limb injury were included in the study. Ankle joint mobilization and calf muscle massage were applied for 5 min in a random order, one to two weeks apart. Ankle dorsiflexion was measured by using the weight-bearing lunge pre- and post-intervention (cm). Paired t-tests were used to analyze the effect of the manual therapy interventions on restricted ankles. A minimal detectable difference 95% (MMD95) was calculated. The pilot study was analyzed for suitability of inclusion criteria, blinding of assessors and the manual therapist, and the washout period. RESULTS: A significant increase in dorsiflexion was demonstrated for ankle joint mobilization (change score = 0.51 ± 0.76, p = 0.003) and calf muscle soft tissue massage (change score = 0.91 ± 1.07, p < 0.001). There was no difference in change scores between manual therapy techniques (mobilization 0.51 ± 0.76, massage 0.91 ± 1.07, p = 0.12). Evaluation of the pilot study revealed limitations to be modified in future studies. CONCLUSION: These preliminary data indicate ankle joint mobilization and calf muscle soft tissue massage had similar effects on increasing ankle dorsiflexion range of motion in ankles with residual dorsiflexion restriction.

Quantitative trait loci analysis reveals candidate genes implicated in regulating functional deficit and CNS vascular permeability in CD8 T cell-initiated blood-brain barrier disruption.

BACKGROUND: Blood-brain barrier (BBB) disruption is an integral feature of numerous neurological disorders. However, there is a relative lack of knowledge regarding the underlying molecular mechanisms of immune-mediated BBB disruption. We have previously shown that CD8 T cells and perforin play critical roles in initiating altered permeability of the BBB in the peptide-induced fatal syndrome (PIFS) model developed by our laboratory. Additionally, despite having indistinguishable CD8 T cell responses, C57BL/6J (B6) mice are highly susceptible to PIFS, exhibiting functional motor deficits, increased astrocyte activation, and severe CNS vascular permeability, while 129S1/SvImJ (129S1) mice remain resistant. Therefore, to investigate the potential role of genetic factors, we performed a comprehensive genetic analysis of (B6 x 129S1) F2 progeny to define quantitative trait loci (QTL) linked to the phenotypic characteristics stated above that mediate CD8 T cell-initiated BBB disruption. RESULTS: Using single nucleotide polymorphism (SNP) markers and a 95% confidence interval, we identified one QTL (PIFS1) on chromosome 12 linked to deficits in motor function (SNP markers rs6292954, rs13481303, rs3655057, and rs13481324, LOD score = 3.3). In addition we identified a second QTL (PIFS2) on chromosome 17 linked to changes in CNS vascular permeability (SNP markers rs6196216 and rs3672065, LOD score = 3.7). CONCLUSIONS: The QTL critical intervals discovered have allowed for compilation of a list of candidate genes implicated in regulating functional deficit and CNS vascular permeability. These genes encode for factors that may be potential targets for therapeutic approaches to treat disorders characterized by CD8 T cell-mediated BBB disruption.

Perinatal outcomes of prenatal probiotic and prebiotic administration: an integrative review.

The purpose of this integrative review was to identify, critique, and synthesize the maternal and neonatal evidence on the prenatal use of probiotics and prebiotics to inform perinatal health professionals. A comprehensive literature search resulted in 37 studies of prenatal probiotics and 1 on antepartal prebiotics published from 1990 through 2011 that reported maternal, fetal, and/or neonatal outcomes. The methodologic quality of the studies reviewed was high, although investigators used different probiotic combinations and inconsistently reported perinatal clinical outcomes. The extraction of perinatal outcome variables resulted in identification of 9 maternal and 5 neonatal categories. Prenatal probiotics significantly reduced the incidence of bacterial vaginosis, increased colonization with vaginal Lactobacillus and intestinal Lactobacillus rhamnosus, altered immune markers in serum and breast milk, improved maternal glucose metabolism, and reduced the incidence of gestational diabetes and preeclampsia. Antepartally, probiotics were associated with significantly higher counts of Bifidobacterium and Lactococcus lactis (healthy intestinal flora) in neonatal stool. Prenatal prebiotics significantly increased maternal intestinal Bifidobacterium. No adverse events were reported and there was evidence of safety and tolerance of prenatal probiotics and prebiotics in the scientific investigations reviewed. It is recommended that in future investigations of prenatal probiotics researchers explicitly report maternal and neonatal outcomes.

Comparing Experiences of Women Who Were Direct Breastfeeding and Women Who Used Expressed Breast Milk to Feed Their Infants.

PURPOSE: To provide understanding about feeding experiences of women who provide breast milk through direct breastfeeding and exclusive expression and to compare these experiences. STUDY DESIGN AND METHODS: A qualitative study was conducted to gather experiences from the perspectives of women who had given birth to a healthy, term infant within the past 12 months and exclusively fed breast milk for at least 2 weeks. The sample was recruited from motherhood and breastfeeding support groups on Facebook. Groups had state- or national-based memberships. Interviews were examined for themes that were compared between feeding groups using thematic analysis. RESULTS: Fifteen new mothers participated. Under the primary themes of Similarities and Differences, seven subthemes were identified: Fatigue, Importance of Support, Finding Joy in a Common Goal, Mixed Feelings, Trusting versus Tracking, Latching versus Body Failure, and Pumping in Isolation. CLINICAL IMPLICATIONS: Mothers who provide breast milk share common experiences and feelings of satisfaction. Expressed breast milk feeding offers some mothers a way to provide the benefits of breast milk while preserving a balance between maternal and infant physical and mental health needs. Understanding the different ways in which women manage breast milk feeding while balancing maternal and infant needs can prepare nurses to discuss various methods of breast milk feeding and provide individualized support.

Comparison of telehealth and supervised phase III cardiac rehabilitation in regional Australia: protocol for a non-inferiority trial.

INTRODUCTION: Exercise-based cardiac rehabilitation programmes (ExCRP) promote recovery and secondary prevention for individuals with cardiovascular disease (CVD). Despite this, enrolment and adherence to ExCRP in rural locations is low. Telehealth programmes provide a convenient, home-based intervention, but concerns remain about compliance to exercise prescription. This paper presents the rationale and protocol design to determine if telehealth delivered ExCRP is not inferior to supervised ExCRP for improving cardiovascular function and exercise fidelity. METHOD AND ANALYSIS: A non-inferiority, parallel (1:1), single-blinded randomised clinical trial will be conducted. Fifty patients with CVD will be recruited from a rural phase II ExCRP. Participants will be randomly assigned to telehealth or supervised ExCRP and prescribed three weekly exercise sessions for 6 weeks. Exercise sessions will include a 10 min warm up, up to 30 min of continuous aerobic exercise at a workload equivalent to the ventilatory anaerobic threshold and a 10 min cool down. The primary outcome will be change in cardiorespiratory fitness as measured by cardiopulmonary exercise test. Secondary outcome measures will include change in blood lipid profile, heart rate variability, pulse wave velocity, actigraphy measured sleep quality and training fidelity. Non-inferiority will be confirmed if intention-to-treat and per-protocol analyses conclude the same outcome following independent samples t-test with p<0.025. ETHICS AND DISSEMINATION: Research ethics committees at La Trobe University, St John of God Health Care and Bendigo Health approved the study protocol and informed consent. Findings will be published in peer-reviewed journals and disseminated among stakeholders. TRIAL REGISTRATION NUMBER: ACTRN12622000872730p; pre-results.

A randomized controlled trial of an oral probiotic to reduce antepartum group B Streptococcus colonization and gastrointestinal symptoms.

BACKGROUND: Probiotics have been suggested as a strategy to reduce antenatal group B Streptococcus colonization. Although probiotics are known to improve gastrointestinal symptoms, this has not been studied during pregnancy. OBJECTIVE: This study aimed to evaluate the efficacy of a probiotic to reduce: (1) standard-of-care antenatal group B Streptococcus colonization and colony counts and (2) gastrointestinal symptoms of pregnancy. STUDY DESIGN: In a double-blind fashion, 109 healthy adult pregnant people were randomized to Florajen3 probiotic or placebo capsules once daily from 28 weeks' gestation until labor onset. Baseline vaginal and rectal study swabs for group B Streptococcus colony-forming units and microbiome analysis were collected at 28 and 36 weeks' gestation. Standard-of-care vaginal to rectal group B Streptococcus swabs were collected from all participants at 36 weeks' gestation and determined the need for intrapartum antibiotic prophylaxis. Data collection included solicitation of adverse events, demographic information, Antepartum Gastrointestinal Symptom Assessment score, yogurt ingestion, sexual activity, and vaginal cleaning practices. RESULTS: A total of 83 participants completed the study to 36 weeks' gestation with no adverse events. Standard-of-care group B Streptococcus colonization was 20.4% in the control group and 15.4% in probiotic group participants (-5%; P=.73). The relative risk for positive standard-of-care vaginal-rectal group B Streptococcus colonization was 1.33 (95% confidence interval, 0.5-3.40) times higher in the control group than in the probiotic group (P=.55). There were no differences in median vaginal (P=.16) or rectal (P=.20) group B streptococcus colony-forming units at baseline or at 36 weeks (vaginal P>.999; rectal P=.56). Antepartum Gastrointestinal Symptom Assessment scores were similar at baseline (P=.19), but significantly decreased in probiotic group participants at 36 weeks (P=.02). No covariates significantly altered group B Streptococcus colonization. Significantly more Florajen3 bacteria components were recovered from the vaginal-rectal samples of probiotic group participants (32%; P=.04) compared with controls. CONCLUSION: The findings of this study provided insufficient evidence for the clinical application of the Florajen3 probiotic intervention to reduce standard-of-care vaginal-rectal group B Streptococcus colonization. The prevalence of group B Streptococcus was lower than expected in the study population, and intervention adherence was poor. Probiotic bacteria colonization of the genitourinary tract occurred more in intervention group participants than in controls and significantly reduced gastrointestinal symptoms of pregnancy.

A hematopoietic contribution to microhemorrhage formation during antiviral CD8 T cell-initiated blood-brain barrier disruption.

BACKGROUND: The extent to which susceptibility to brain hemorrhage is derived from blood-derived factors or stromal tissue remains largely unknown. We have developed an inducible model of CD8 T cell-initiated blood-brain barrier (BBB) disruption using a variation of the Theiler's murine encephalomyelitis virus (TMEV) model of multiple sclerosis. This peptide-induced fatal syndrome (PIFS) model results in severe central nervous system (CNS) vascular permeability and death in the C57BL/6 mouse strain, but not in the 129 SvIm mouse strain, despite the two strains' having indistinguishable CD8 T-cell responses. Therefore, we hypothesize that hematopoietic factors contribute to susceptibility to brain hemorrhage, CNS vascular permeability and death following induction of PIFS. METHODS: PIFS was induced by intravenous injection of VP2121-130 peptide at 7 days post-TMEV infection. We then investigated brain inflammation, astrocyte activation, vascular permeability, functional deficit and microhemorrhage formation using T2*-weighted magnetic resonance imaging (MRI) in C57BL/6 and 129 SvIm mice. To investigate the contribution of hematopoietic cells in this model, hemorrhage-resistant 129 SvIm mice were reconstituted with C57BL/6 or autologous 129 SvIm bone marrow. Gadolinium-enhanced, T1-weighted MRI was used to visualize the extent of CNS vascular permeability after bone marrow transfer. RESULTS: C57BL/6 and 129 SvIm mice had similar inflammation in the CNS during acute infection. After administration of VP2121-130 peptide, however, C57BL/6 mice had increased astrocyte activation, CNS vascular permeability, microhemorrhage formation and functional deficits compared to 129 SvIm mice. The 129 SvIm mice reconstituted with C57BL/6 but not autologous bone marrow had increased microhemorrhage formation as measured by T2*-weighted MRI, exhibited a profound increase in CNS vascular permeability as measured by three-dimensional volumetric analysis of gadolinium-enhanced, T1-weighted MRI, and became moribund in this model system. CONCLUSION: C57BL/6 mice are highly susceptible to microhemorrhage formation, severe CNS vascular permeability and morbidity compared to the 129 SvIm mouse. This susceptibility is transferable with the bone marrow compartment, demonstrating that hematopoietic factors are responsible for the onset of brain microhemorrhage and vascular permeability in immune-mediated fatal BBB disruption.

Immunosuppressive effects of red blood cells on monocytes are related to both storage time and storage solution.

BACKGROUND: Reduced monocyte function is associated with adverse outcomes from critical illness. Red blood cells (RBCs) are thought to impair monocyte function but relationships between RBC storage solution and monocyte suppression are unknown. This study was designed to test the hypothesis that immunosuppressive effects of RBCs on monocytes are related to both storage time and preservative solution. STUDY DESIGN AND METHODS: Monocytes from healthy adult donors were co-cultured with RBCs that had been stored in AS-1, AS-3, or CPD only for 7, 14, or 21 days. Cells were then stimulated with lipopolysaccharide (LPS) and their supernatants assayed for tumor necrosis factor (TNF)-α and interleukin (IL)-10. Transwell experiments were performed to evaluate the role of cell-to-cell contact. Monocyte mRNA expression was quantified by real-time-polymerase chain reaction. RESULTS: LPS-induced TNF-α production capacity was reduced compared to controls for all groups, but CPD-only RBCs suppressed monocyte function more than RBCs stored in AS-1 (p = 0.007) and AS-3 (p = 0.006). IL-10 production was preserved or augmented in all groups. A longer storage time was associated with reduced TNF-α production capacity for AS-1 and AS-3 groups but not CPD. Preventing cell-to-cell contact did not eliminate the inhibitory effect of RBCs on monocyte responsiveness. RBC exposure was associated with decreased LPS-induced TNFA mRNA expression (p < 0.05 for all groups). CONCLUSIONS: CPD-only RBCs suppressed monocyte function more than RBCs stored with additive solutions. TNF-α production was reduced even in the absence of cell-to-cell contact and was impaired at the mRNA level. Further work is needed to understand the role of preservative solutions in this process.