Bioprosthetic valve thrombosis and degeneration following transcatheter aortic valve implantation (TAVI).

Bioprosthetic valve thrombosis (BPVT) is a recognised complication of prosthetic aortic valves and can be found in up to 13% of patients after transcatheter implantation. The mechanism of BPVT is not well known, abnormal flow conditions in the new and native sinuses and lack of functional endothelialisation are suspected causes. BPVT may result in valve dysfunction, possibly related to degeneration, and recurrence of patient symptoms, or remain subclinical. BPVT is best diagnosed at multiphase gated computed tomography (CT) angiography as the presence of reduced leaflet motion (RELM) and hypoattenuating aortic leaflet thickening (HALT). Although CT is used to exclude BPVT in symptomatic patients and those with increased valve gradients, the value of screening and prophylactic anticoagulation is debatable.

Factors associated with maternal death from direct pregnancy complications: a UK national case-control study.

OBJECTIVE: To investigate the factors associated with maternal death from direct pregnancy complications in the UK. DESIGN: Unmatched case-control analysis. SETTING: All hospitals caring for pregnant women in the UK. POPULATION: A total of 135 women who died (cases) between 2009 and 2012 from eclampsia, pulmonary embolism, severe sepsis, amniotic fluid embolism, and peripartum haemorrhage, using data from the Confidential Enquiry into Maternal Death, and another 1661 women who survived severe complications (controls) caused by these conditions (2005-2013), using data from the UK Obstetric Surveillance System. METHODS: Multivariable regression analyses were undertaken to identify the factors that were associated with maternal deaths and to estimate the additive odds associated with the presence of one or more of these factors. MAIN OUTCOME MEASURES: Odds ratios associated with maternal death and population-attributable fractions, with 95% confidence intervals. Incremental risk of death associated with the factors using a 'risk factors' score. RESULTS: Six factors were independently associated with maternal death: inadequate use of antenatal care (adjusted odds ratio, aOR 15.87, 95% CI 6.73-37.41); substance misuse (aOR 10.16, 95% CI 1.81-57.04); medical comorbidities (aOR 4.82, 95% CI 3.14-7.40); previous pregnancy problems (aOR 2.21, 95% CI 1.34-3.62); hypertensive disorders of pregnancy (aOR 2.44, 95% CI 1.31-4.52); and Indian ethnicity (aOR 2.70, 95% CI 1.14-6.43). Of the increased risk associated with maternal death, 70% (95% CI 66-73%) could be attributed to these factors. Odds associated with maternal death increased by three and a half times per unit increase in the 'risk factor' score (aOR 3.59, 95% CI 2.83-4.56). CONCLUSIONS: This study shows that medical comorbidities are importantly associated with direct (obstetric) deaths. Further studies are required to understand whether specific aspects of care could be improved to reduce maternal deaths among women with medical comorbidities in the UK.

The management and outcomes of placenta accreta, increta, and percreta in the UK: a population-based descriptive study.

OBJECTIVE: To describe the management and outcomes of placenta accreta, increta, and percreta in the UK. DESIGN: A population-based descriptive study using the UK Obstetric Surveillance System (UKOSS). SETTING: All 221 UK hospitals with obstetrician-led maternity units. POPULATION: All women diagnosed with placenta accreta, increta, and percreta in the UK between May 2010 and April 2011. METHODS: Prospective case identification through the monthly mailing of UKOSS. MAIN OUTCOME MEASURES: Median estimated blood loss, transfusion requirements. RESULTS: A cohort of 134 women were identified with placenta accreta, increta, or percreta: 50% (66/133) were suspected to have this condition antenatally. In women with a final diagnosis of placenta increta or percreta, antenatal diagnosis was associated with reduced levels of haemorrhage (median estimated blood loss 2750 versus 6100 ml, P = 0.008) and a reduced need for blood transfusion (59 versus 94%, P = 0.014), possibly because antenatally diagnosed women were more likely to have preventative therapies for haemorrhage (74 versus 52%, P = 0.007), and were less likely to have an attempt made to remove their placenta (59 versus 93%, P < 0.001). Making no attempt to remove any of the placenta, in an attempt to conserve the uterus or prior to hysterectomy, was associated with reduced levels of haemorrhage (median estimated blood loss 1750 versus 3700 ml, P = 0.001) and a reduced need for blood transfusion (57 versus 86%, P < 0.001). CONCLUSIONS: Women with placenta accreta, increta, or percreta who have no attempt to remove any of their placenta, with the aim of conserving their uterus, or prior to hysterectomy, have reduced levels of haemorrhage and a reduced need for blood transfusion, supporting the recommendation of this practice.

Bidirectional scatter measurements of a guided-mode resonant filter photonic crystal structure.

This work investigates the Bidirectional Scatter Distribution Function (BSDF) at incident angles other than normal and at 544-nm wavelength of a Guided Mode Resonance Filter (GMRF) Photonic Crystal (PC) structure designed for normally incident light at 532 nm. Strong out-coupling of PC diffraction orders into both the transmitted and reflected hemispheres was observed specifically at a 25.7° incidence angle, which we attribute to this incident angle/wavelength pair being a good match to the ( ± 1, 0) PC grating mode. BSDF measurements at incident angles of 15° and 35° also displayed some out-coupled diffraction, though much lower in magnitude, and are also attributed to being a weaker match to the ( ± 1, 0) PC grating mode. Three-dimensional finite-difference time-domain Maxwell's equation simulations demonstrate that since this GMRF was designed for complete destructive interference of the transmitted light upon normal incidence, stronger out-coupling of the diffraction is expected for modal solutions as the angle of incidence increases.

British HIV Association and Children's HIV Association position statement on infant feeding in the UK 2011.

To prevent the transmission of HIV infection during the postpartum period, the British HIV Association and Children's HIV Association (BHIVA/CHIVA) continue to recommend the complete avoidance of breast feeding for infants born to HIV-infected mothers, regardless of maternal disease status, viral load or treatment.

Generalized diffusion equation for anisotropic anomalous diffusion.

Motivated by studies of comblike structures, we present a generalization of the classical diffusion equation to model anisotropic, anomalous diffusion. We assume that the diffusive flux is given by a diffusion tensor acting on the gradient of the probability density, where each component of the diffusion tensor can have its own scaling law. We also assume scaling laws that have an explicit power-law dependence on space and time. Solutions of the proposed generalized diffusion equation are consistent with previously derived asymptotic results for the probability density on comblike structures.

Why is there a modifying effect of gestational age on risk factors for cerebral palsy?

OBJECTIVE: To investigate risk factors for cerebral palsy in relation to gestational age. DESIGN: Three case-control studies within a geographically defined cohort. SETTING: The former Oxfordshire Health Authority. PARTICIPANTS: A total of 235 singleton children with cerebral palsy not of postnatal origin, born between 1984 and 1993, identified from the Oxford Register of Early Childhood Impairment; 646 controls matched for gestation in three bands: or=37 weeks. RESULTS: Markers of intrapartum hypoxia and infection were associated with an increased risk of cerebral palsy in term and preterm infants. The odds ratio (OR) for hypoxia was 12.2 (95% confidence interval 1.2 to 119) at or=37 weeks. Corresponding ORs for neonatal sepsis were 3.1 (1.8 to 5.4) and 10.6 (2.1 to 51.9). In contrast, pre-eclampsia carried an increased risk of cerebral palsy at >or=37 weeks (OR 5.1 (2.2 to 12.0)) but a decreased risk at

Analysis of origin and optimization of expansion and transduction of circulating peripheral blood endothelial progenitor cells in the rhesus macaque model.

Adult marrow-derived cells have been shown to contribute to various nonhematologic tissues and, conversely, primitive cells isolated from nonhematopoietic tissues have been shown to reconstitute hematopoiesis. Circulating endothelial progenitor cells (EPCs) have been reported to be at least partially donor derived after allogeneic bone marrow transplantation, and shown to contribute to neovascularization in murine ischemia models. However, it is unknown whether these EPCs are actually clonally derived from the same population of stem and progenitor cells that reconstitute hematopoiesis, or from another cell population found in the marrow or mobilized blood that is transferred during transplantation. To approach this question, we characterized circulating EPCs and also endothelial cells from large vessels harvested at autopsy from rhesus macaques previously transplanted with retrovirally transduced autologous CD34-enriched peripheral blood stem cells (PBSCs). Endothelial cells were grown in culture for 21-28 days and were characterized as CD31(+) CD14(-) via flow cytometry, as acLDL(+) UEA-1(+) via immunohistochemistry, and as Flk-1(+) by reverse transcriptase-polymerase chain reaction (RT-PCR). Animals had stable vector marking in hematopoietic lineages of 2-15%. Neither cultured circulating EPCs collected in steady state (n = 3), nor endothelial cells grown from large vessels (n = 2), had detectable retroviral marking. EPCs were CD34(+) and could be mobilized into the circulation with granulocyte colony-stimulating factor. Under ex vivo culture conditions, in which CD34(+) cells were optimized to transduce hematopoietic progenitor and stem cells, there was a marked depletion of EPCs. Transduction of EPCs was much more efficient under conditions supporting endothelial cell growth. Further elucidation of the origin and in vivo behavior of EPCs may be possible, using optimized transduction conditions and a vascular injury model.

In vivo persistence of retrovirally transduced murine long-term repopulating cells is not limited by expression of foreign gene products in the fully or minimally myeloablated setting.

Many nonmalignant hematologic disorders could potentially be treated by genetic correction of as few as 5-10% of target lineage cells. However, immune system clearance of cells expressing gene products perceived as foreign could be limiting. There is evidence that tolerance to foreign proteins can result when myeloablative conditioning is used, but this limits the overall applicability of such techniques. Therefore, we sought to evaluate the engraftment of hematopoietic stem cells carrying a foreign transgene after low-dose irradiation by comparing in vivo survival of murine long-term repopulating cells (LTRC) transduced with either a retroviral vector expressing the bacterial neomycin phosphotransferase gene (neo) or a vector containing neo gene sequences but modified to prevent protein expression (nonexpression). First, marrow cells from congenic donors were transduced with either vector and transplanted into recipients treated with standard dose irradiation of 800 rads. High-level engraftment and gene marking resulted, without differences in the marking levels or pattern of persistence of the cells between cells transduced with either vector. Low-dose irradiation at 100 rads was tested using higher cell doses. Marking levels as high as 10% overall were obtained, again with no differences between mice receiving cells transduced with the neo versus the nonexpression vectors. To investigate a potentially more immunogenic protein, marrow cells were transduced with a vector containing the green fluorescent protein (GFP) gene, and their persistence was studied in recipient mice receiving 100 rads. Stable GFP expression in 5-10% of circulating cells was observed long term. We conclude that even with very low dose conditioning, engraftment by genetically modified LTRC cells at clinically significant levels can be achieved without evidence for clearance of cells known to be expressing immunogenic proteins.

Avoidance of stimulation improves engraftment of cultured and retrovirally transduced hematopoietic cells in primates.

Recent reports suggest that cells in active cell cycle have an engraftment defect compared with quiescent cells. We used nonhuman primates to investigate this finding, which has direct implications for clinical transplantation and gene therapy applications. Transfer of rhesus CD34(+) cells to culture in stem cell factor (SCF) on the CH-296 fibronectin fragment (FN) after 4 days of culture in stimulatory cytokines maintained cell viability but decreased cycling. Using retroviral marking with two different gene transfer vectors, we compared the engraftment potential of cytokine-stimulated cells versus those transferred to nonstimulatory conditions (SCF on FN alone) before reinfusion. In vivo competitive repopulation studies showed that the level of marking originating from the cells continued in culture for 2 days with SCF on FN following a 4-day stimulatory transduction was significantly higher than the level of marking coming from cells transduced for 4 days and reinfused without the 2-day culture under nonstimulatory conditions. We observed stable in vivo overall gene marking levels of up to 29%. This approach may allow more efficient engraftment of transduced or ex vivo expanded cells by avoiding active cell cycling at the time of reinfusion.

Dry powders of stable protein formulations from aqueous solutions prepared using supercritical CO(2)-assisted aerosolization.

We report on the use of a new supercritical carbon dioxide-assisted aerosolization coupled with bubble drying technology to prepare stabilized, dry, finely divided powders from aqueous protein formulations. In this study, the feasibility of this new technology was tested using two model proteins, lysozyme and lactate dehydrogenase (LDH). In the absence of excipients, lysozyme was observed to undergo perturbations of secondary structure observed by solid-state infrared spectroscopy. In the presence of sucrose, this unfolding was minimized. Lysozyme did not, however, undergo irreversible loss of activity, as all lysozyme powders generated by supercritical CO(2)-assisted aerosolization (with or without excipients) regained almost complete activity on reconstitution. The more labile LDH suffered irrecoverable loss of activity on reconstituting after supercritical CO(2)-assisted aerosolization and bubble drying in the absence of carbohydrate stabilizers. LDH could be stabilized throughout the nebulization, drying, and rehydration processes with the addition of sucrose, and almost complete preservation of activity was achieved with the further addition of a surface active agent, such as Tween 20, to the aqueous formulation prior to processing.

The effects of SCF/G-CSF prestimulation on radiation sensitivity and engraftment in nonmyeloablated murine hosts.

OBJECTIVE: Previous studies have shown improved engraftment in a murine model when granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) were administered for 5 days prior to irradiation, with significant levels of engraftment in the growth factor-preconditioned group even at very low radiation doses. We sought to explore the mechanisms behind this effect. METHODS: The radiation sensitivity of mice with or without 5 days of prestimulation with G-CSF (200 microg/kg/d) and SCF (50 microg/kg/d) was compared. To further evaluate whether growth factor prestimulation enhances engraftment by mobilization of hematopoietic progenitors into peripheral blood, thus creating less endogenous competition within the marrow compartment, female mice were pretreated with 5 days of G-CSF/SCF or control diluent. Engraftment of 40 x 10(6) peripheral blood stem cells (PBSCs) harvested from G-CSF/SCF-mobilized male mice was compared in the two recipient groups. RESULTS: There was no difference in survival between the pretreated and control mice at the radiation doses tested. Additionally, there was no significant difference in the recovery of blood counts, bone marrow cellularity, colony-forming unit (CFU) content, or stem cell numbers assessed 4 months later in a competitive repopulation model. Engraftment levels of male cells did not differ between G-CSF/SCF-pretreated and control recipients, and could be detected in 30% of recipients at 20-24 weeks (4/12 in each group) at overall levels of 0.1-1%. CONCLUSIONS: The enhanced engraftment in cytokine pretreated recipients is unlikely to be due to increased endogenous stem-cell killing or to the creation of endogenous marrow "space" by egress of endogenous stem cells after cytokine prestimulation.

Low-dose fluticasone propionate compared with montelukast for first-line treatment of persistent asthma: a randomized clinical trial.

BACKGROUND: Both inhaled corticosteroids and leukotriene modifiers are used in the maintenance treatment of persistent asthma. OBJECTIVE: The goal was to compare the efficacy and safety of low-dose fluticasone propionate (FP) and montelukast as first-line maintenance therapy in symptomatic patients by using short-acting beta2-agonists alone to treat persistent asthma. METHODS: In this multicenter, randomized, double-blind, double-dummy, parallel-group study, 533 patients (>15 years old) with persistent asthma who remained symptomatic while taking short-acting beta2-agonists alone were treated with FP (88 microg [2 puffs of 44 microg] twice daily) or montelukast (10 mg once daily) for 24 weeks. RESULTS: Compared with treatment with montelukast, treatment with FP resulted in significantly greater improvements at endpoint in morning predose FEV(1) (22.9% vs 14.5%, P <.001), forced midexpiratory flow (0.66 vs 0.41 L/sec, P <.001), forced vital capacity (0.42 vs 0.29 L, P =.002), morning peak expiratory flow (PEF) (68.5 vs 34.1 L/min, P <.001), and evening PEF (53.9 vs 28.7 L/min, P <.001). Similar improvements in PEF were observed in patients with milder asthma (>70%-80% predicted FEV(1)). At endpoint, FP was more effective than montelukast at decreasing rescue albuterol use (3.1 puffs/day vs 2.3 puffs/day, P <.001), asthma symptom scores (-0.85 [48.6% decrease] vs -0.60 [30.5%], P <.001), and nighttime awakenings due to asthma (-0.64 awakenings/night [62% decrease] vs -0.48 awakenings/night [47.5%], P =.023), and FP increased the percentage of symptom-free days (32.0% vs 18.4% of days, P <.001) compared with montelukast. The adverse event and asthma exacerbation profiles for FP and montelukast were similar. CONCLUSIONS: Low-dose FP is more effective than montelukast as first-line maintenance therapy for patients with persistent asthma who are undertreated and remain symptomatic while taking short-acting beta2-agonists alone.

The effect of multidrug-resistance 1 gene versus neo transduction on ex vivo and in vivo expansion of rhesus macaque hematopoietic repopulating cells.

Transduction of murine stem cells with a multidrug-resistance 1 gene (MDR1) retrovirus results in dramatic ex vivo and in vivo expansion of repopulating cells accompanied by a myeloproliferative disorder. Given the use of MDR1-containing vectors in human trials, investigations have been extended to nonhuman primates. Peripheral blood stem cells from 2 rhesus monkeys were collected, CD34-enriched, split into 2 portions, and transduced with either MDR1 vectors or neo vectors and continued in culture for a total of 10 days before reinfusion. At engraftment, the copy number in granulocytes was extremely high from both MDR vectors and neo vectors, but the copy number fell to 0.01 to 0.05 for both. There were no perturbations of the leukocyte count or differential noted. After 3 cycles of stem cell factor/granulocyte colony-stimulating factor, there were no changes in the levels of MDR1 vector- or neo vector-containing cells. There was no evidence for expansion of MDR1 vector-transduced cells. Long-term engraftment with MDR1 vector- and neo vector-transduced cells occurred despite prolonged culture.

The spiritual care meanings of adults residing in the midwest.

Only limited nursing knowledge exists as theoretical guidance for nurses in providing spiritual care. Using Leininger's theory of culture care diversity and universality, the purpose of this ethnonursing research study was to discover the embedded spiritual care meanings, expressions, lived experiences, and practices of adults residing in the Midwest and their perceptions of spiritual nursing care. Data were collected through interviews of 6 key and 12 general informants. Five universal spiritual themes were supported by the findings. Culture care modes were used to explicate spiritual knowledge that can be integrated into nursing practice.

Prolonged high-level detection of retrovirally marked hematopoietic cells in nonhuman primates after transduction of CD34+ progenitors using clinically feasible methods.

Low-level retroviral transduction and engraftment of hematopoietic long-term repopulating cells in large animals and humans remain primary obstacles to the successful application of hematopoietic stem cell (HSC) gene transfer in humans. Recent studies have reported improved efficiency by including stromal cells (STR), or the fibronectin fragment CH-296 (FN), and various cytokines such as flt3 ligand (FLT) during ex vivo culture and transduction in nonhuman primates. In this work, we extend our studies using the rhesus competitive repopulation model to further explore optimal and clinically feasible peripheral blood (PB) progenitor cell transduction methods. First, we compared transduction in the presence of either preformed autologous STR or immobilized FN. Long-term clinically relevant gene marking levels in multiple hematopoietic lineages from both conditions were demonstrated in vivo by semiquantitative PCR, colony PCR, and genomic Southern blotting, suggesting that FN could replace STR in ex vivo transduction protocols. Second, we compared transduction on FN in the presence of IL-3, IL-6, stem cell factor (SCF), and FLT (our best cytokine combination in prior studies) with a combination of megakaryocyte growth and development factor (MGDF), SCF, and FLT. Gene marking levels were equivalent in these animals, with no significant effect on retroviral gene transfer efficiency assessed in vivo by the replacement of IL-3 and IL-6 with MGDF. Our results indicate that SCF/G-CSF-mobilized PB CD34+ cells are transduced with equivalent efficiency in the presence of either STR or FN, with stable long-term marking of multiple lineages at levels of 10-15% and transient marking as high as 54%. These results represent an advance in the field of HSC gene transfer using methods easily applied in the clinical setting.

Introduction of a xenogeneic gene via hematopoietic stem cells leads to specific tolerance in a rhesus monkey model.

Host immune responses against foreign transgenes may be a major obstacle to successful gene therapy. To clarify the impact of an immune response to foreign transgene products on the survival of genetically modified cells, we studied the in vivo persistence of cells transduced with a vector expressing a foreign transgene compared to cells transduced with a nonexpressing vector in the clinically predictive rhesus macaque model. We constructed retroviral vectors containing the neomycin phosphotransferase gene (neo) sequences modified to prevent protein expression (nonexpressing vectors). Rhesus monkey lymphocytes or hematopoietic stem cells (HSCs) were transduced with nonexpressing and neo-expressing vectors followed by reinfusion, and their in vivo persistence was studied. While lymphocytes transduced with a nonexpressing vector could be detected for more than 1 year, lymphocytes transduced with a neo-expressing vector were no longer detectable within several weeks of infusion. However, five of six animals transplanted with HSCs transduced with nonexpression or neo-expression vectors, and progeny lymphocytes marked with either vector persisted for more than 2 years. Furthermore, in recipients of transduced HSCs, infusion of mature lymphocytes transduced with a second neo-expressing vector did not result in elimination of the transduced lymphocytes. Our data show that introduction of a xenogeneic gene via HSCs induces tolerance to the foreign gene products. HSC gene therapy is therefore suitable for clinical applications where long-term expression of a therapeutic or foreign gene is required.

Many multipotential gene-marked progenitor or stem cell clones contribute to hematopoiesis in nonhuman primates.

Retroviral insertion site analysis was used to track the contribution of retrovirally transduced primitive progenitors to hematopoiesis after autologous transplantation in the rhesus macaque model. CD34-enriched mobilized peripheral blood cells were transduced with retroviral marking vectors containing the neo gene and were reinfused after total body irradiation. High-level gene transfer efficiency allowed insertion site analysis of individual myeloid and erythroid colony-forming units (CFU) and of highly purified B- and T-lymphoid populations in 2 animals. At multiple time points up to 1 year after transplantation, retroviral insertion sites were identified by performing inverse polymerase chain reaction and sequencing vector-containing CFU or more than 99% pure T- and B-cell populations. Forty-eight unique insertion sequences were detected in the first animal and also in the second animal, and multiple clones contributed to hematopoiesis at 2 or more time points. Multipotential clones contributing to myeloid and lymphoid lineages were identified. These results support the concept that hematopoiesis in large animals is polyclonal and that individual multipotential stem or progenitor cells can contribute to hematopoiesis for prolonged periods. Gene transfer to long-lived, multipotent clones is shown and is encouraging for human gene therapy applications.

Cytomegalovirus urinary excretion and long term outcome in children with congenital cytomegalovirus infection. Congenital CMV Longitudinal Study Group.

BACKGROUND: Cytomegalovirus (CMV) is the most frequent cause of congenital infection, and both symptomatic and asymptomatic infants may have long term sequelae. Children with congenital CMV infection are chronically infected and excrete CMV in the urine for prolonged periods. However, the effect of prolonged viral replication on the long term outcome of these children is unknown. OBJECTIVE: To determine whether duration of CMV excretion is associated with outcome at 6 years of life in symptomatic and asymptomatic congenitally infected children. METHODS: Longitudinal cohort study. Children congenitally infected with CMV were identified at birth and followed prospectively in a study of long term effects of congenital CMV infection. The relationship between duration of CMV urinary excretion and growth, neurodevelopment and presence and progression of sensorineural hearing loss (SNHL) at 6 years of age was determined. RESULTS: There was no significant difference in the duration of viral urinary excretion between children born with asymptomatic (median, 4.55 years) and symptomatic (median, 2.97 years) congenital CMV infection (P = 0.11). Furthermore there was no association between long term growth or cognitive outcome and duration of viral excretion. However, a significantly greater proportion of children who excreted CMV for <4 years had SNHL and progressive SNHL compared with children with CMV excretion >4 years (P = 0.019, P = 0.009, respectively). CONCLUSIONS: Children congenitally infected with CMV are chronically infected for years, but the duration of CMV urinary excretion is not associated with abnormalities of growth, or neurodevelopmental deficits. However, SNHL and progressive SNHL were associated with a shorter duration of CMV excretion.