2,033 research outputs found
Laser force cytology for rapid quantification of viral infectivity
The quantification of viral infectivity is an integral step at multiple stages in the process of virally producing recombinant protein, studying the mechanism of viral infection, and developing vaccines. Accurate measurements of infectivity allow for consistent infection and expansion, maximum yield, and assurance that time or environmental conditions have not degraded product quality. Traditional methods to assess infectivity, including the end-point dilution assay (TCID50) and viral plaque assay, are slow, labor intensive, and can vary depending upon the skill and experience of the user. Application of Laser Force Cytology (LFC) for the rapid detection and quantification of viral infection will be presented and discussed for several viral systems in the context of improving the development and production of vaccines. LumaCyte’s Radiance™ instrument is an automated cell analyzer and sorter that measures the optical force, size, shape, and deformability and captures images of single cells. By measuring the intrinsic properties of single cells, cellular changes due to viral infection can be rapidly and objectively quantitated. LFC is very sensitive to agents that perturb cellular structures or change biochemical composition. High quality viral infectivity measurements can be made in a fraction of the time, labor, and cost of traditional assays such as plaque or endpoint dilution. For in-process automated bioreactor monitoring, infectivity can be measured by Radiance in near real-time throughout the process, allowing critical feedback control and optimization. The measurement speed and data quality of LFC / Radiance serve to enhance vaccine development, process optimization/scale-up, and manufacturing to ultimately improve the delivery of vaccines to patients
Use of echocardiography in the management of congestive heart failure in the community
AbstractObjectives. We evaluated the use and the impact of echocardiography in patients receiving an initial diagnosis of congestive heart failure in Olmsted County, Minnesota, in 1991.Background. The American College of Cardiology/American Heart Association clinical practice guidelines recommend echocardiography in all patients with suspected congestive heart failure. No data are available on use and impact of echocardiography in management of congestive heart failure in a community.Methods. The medical records linkage system of the Rochester Epidemiology Project was used to identify all 216 patients who satisfied the Framingham criteria for congestive heart failure. Of these, 137 (63%) underwent echocardiography within 3 weeks before or after the episode of congestive heart failure (Echo group), and the other 79 patients constitute the No-Echo group.Results. The No-Echo group patients were older (p = 0.022), were more likely to be female (p = 0.072), had milder symptoms (p = 0.001) and were less often hospitalized at diagnosis (p = 0.001). Fewer patients in the No-Echo group were treated with angiotensin-converting enzyme inhibitors (p = 0.001). Advanced age (≥80 years), lower New York Heart Association functional class, absence of a fourth heart sound on examination, absence of cardiomegaly or signs of congestive heart failure on chest radiography and absence of known valve disease were independently related to the decision not to obtain an echocardiogram. Survival after adjustment for age, functional class and gender was lower in the No-Echo group than the Echo group (risk ratio = 0.607, p = 0.017).Conclusions. The underuse of echocardiography appears to be associated with poorer survival and underuse of angiotensin-converting enzyme inhibitor therapy
Effects of memory load and distraction on performance and event-related slow potentials in a visuospatial working memory task
Brain electrical activity related to working memory was recorded at 15 scalp electrodes during a visuospatial delayed response task. Participants (N = 18) touched the remembered position of a target on a computer screen after either a 1 or 8 sec delay. These memory trials were compared to sensory trials in which the target remained present throughout the delay and response periods. Distracter stimuli identical to the target were briefly presented during the delay on 30% of trials. Responses were less accurate in memory than sensory trials, especially after the long delay. During the delay slow potentials developed that were significantly more negative in memory than sensory trials. The difference between memory and sensory trials was greater at anterior than posterior electrodes. On trials with distracters, the slow potentials generated by memory trials showed further enhancement of negativity whereas there were minimal effects on accuracy of performance. The results provide evidence that engagement of visuospatial working memory generates slow wave negativity with a timing and distribution consistent with frontal activation. Enhanced brain activity associated with working memory is required to maintain performance in the presence of distraction. © 1997 by the Massachusetts Institute of Technolog
Development of an index to rank dairy females on expected lifetime profit
peer-reviewedThe objective of this study was to develop an index to rank dairy females on expected profit for the remainder of their lifetime, taking cognizance of both additive and nonadditive genetic merit, permanent environmental effects, and current states of the animal including the most recent calving date and cow parity. The cow own worth (COW) index is intended to be used for culling the expected least profitable females in a herd, as well as inform purchase and pricing decisions for trading of females. The framework of the COW index consisted of the profit accruing from (1) the current lactation, (2) future lactations, and (3) net replacement cost differential. The COW index was generated from estimated performance values (sum of additive genetic merit, nonadditive genetic merit, and permanent environmental effects) of traits, their respective net margin values, and transition probability matrices for month of calving, survival, and somatic cell count; the transition matrices were to account for predicted change in a cow’s state in the future. Transition matrices were generated from 3,156,109 lactation records from the Irish national database between the years 2010 and 2013. Phenotypic performance records for 162,981 cows in the year 2012 were used to validate the COW index. Genetic and permanent environmental effects (where applicable) were available for these cows from the 2011 national genetic evaluations and used to calculate the COW index and their national breeding index values (includes only additive genetic effects). Cows were stratified per quartile within herd, based on their COW index value and national breeding index value. The correlation between individual animal COW index value and national breeding index value was 0.65. Month of calving of the cow in her current lactation explained 18% of the variation in the COW index, with the parity of the cow explaining an additional 3 percentage units of the variance in the COW index. Females ranking higher on the COW index yielded more milk and milk solids and calved earlier in the calving season than their lower ranking contemporaries. The difference in phenotypic performance between the best and worst quartiles was larger for cows ranked on COW index than cows ranked on the national breeding index. The COW index is useful to rank females before culling or purchasing decisions on expected profit and is complementary to the national breeding index, which identifies the most suitable females for breeding replacements
Non-typeable Haemophilus influenzae associated early pregnancy loss : an emerging neonatal and maternal pathogen
Objectives There is increasing evidence indicating an association between invasive non-typeable Haemophilus influenzae (NTHi) infection in pregnancy and early pregnancy loss. As the diagnosis relies on microbiological investigation of post-mortem placental and foetal samples, a significant proportion of NTHi-related pregnancy loss remains unrecognised. To better characterise NTHi in septic abortion, we report NTHi cases associated with early pregnancy loss. Methods We reviewed all post-mortems at <24 weeks gestation with histologically proven acute chorioamnionitis on placental histology and enrolled cases with at least one matched foetal and placental sample culture positive for NTHi. The study was approved by the NHS Lothian Caldicott Guardian. Results In our cohort, invasive NTHi has accounted for 20% of infections associated with early pregnancy loss prior to 24 weeks gestation. All patients were young and healthy pregnant women at < 20 weeks' gestation who presented with abdominal pain, PV bleed /discharge and were septic at the time of presentation. One patient with previous history of miscarriage who presented with cervical incompetence had more severe pathology suggestive of early intrauterine pneumonia. Conclusion The burden of invasive NTHi disease in early pregnancy loss is likely to be much larger than currently recognised. NTHi should be considered in pregnant women presenting with abdominal pain and PV bleed/discharge in whom clinical signs of sepsis are present. Active surveillance should be considered in this patient group including septic abortion to capture the true prevalence of this emerging pathogen to inform preventative and therapeutic approaches.Publisher PDFPeer reviewe
Major epidemiological changes in sudden infant death syndrome : a 20-year population-based study in the UK
Background
Results of case-control studies in the past 5 years suggest that the epidemiology of sudden infant death syndrome (SIDS) has changed since the 1991 UK Back to Sleep campaign. The campaign's advice that parents put babies on their back to sleep led to a fall in death rates. We used a longitudinal dataset to assess these potential changes.
Methods
Population-based data from home visits have been collected for 369 consecutive unexpected infant deaths (300 SIDS and 69 explained deaths) in Avon over 20 years (1984—2003). Data obtained between 1993 and 1996 from 1300 controls with a chosen “reference” sleep before interview have been used for comparison.
Findings
Over the past 20 years, the proportion of children who died from SIDS while co-sleeping with their parents, has risen from 12% to 50% (p<0·0001), but the actual number of SIDS deaths in the parental bed has halved (p=0·01). The proportion seems to have increased partly because the Back to Sleep campaign led to fewer deaths in infants sleeping alone—rather than because of a rise in deaths of infants who bed-shared, and partly because of an increase in the number of deaths in infants sleeping with their parents on a sofa. The proportion of deaths in families from deprived socioeconomic backgrounds has risen from 47% to 74% (p=0·003), the prevalence of maternal smoking during pregnancy from 57% to 86% (p=0·0004), and the proportion of pre-term infants from 12% to 34% (p=0·0001). Although many SIDS infants come from large families, first-born infants are now the largest group. The age of infants who bed-share is significantly smaller than that before the campaign, and fewer are breastfed.
Interpretation
Factors that contribute to SIDS have changed in their importance over the past 20 years. Although the reasons for the rise in deaths when a parent sleeps with their infant on a sofa are still unclear, we strongly recommend that parents avoid this sleeping environment. Most SIDS deaths now occur in deprived families. To better understand contributory factors and plan preventive measures we need control data from similarly deprived families, and particularly, infant sleep environments
Preterm birth is associated with immune dysregulation which persists in infants exposed to histologic chorioamnionitis
IntroductionPreterm infants are at increased risk of exposure to histologic chorioamnionitis (HCA) when compared to term-born controls, and this is associated with several neonatal morbidities involving brain, lungs and gut. Preterm infants could benefit from immunomodulatory therapies in the perinatal period, but development of rational treatment strategies requires improved characterization of the perinatal response to HCA. We had two objectives: The first, to characterize the umbilical cord blood immune profile in preterm infants compared to term-born controls; the second, to investigate the postnatal immune response in preterm infants exposed to HCA versus those who were not.PopulationFor objective one 59 term infants [mean gestational age (GA) 39+4 (37+3 to 42+0)] and 55 preterm infants [mean GA29+0(23+3 to 32+0)] with umbilical cord samples available were included; for objective two we studied 96 preterm infants [mean GA29+1(23+2 to 32+0)] for whom placental histology and postnatal blood samples were available.MethodsPlacental histopathology was used to identify reaction patterns indicative of HCA, and a customized immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group.ResultsThe umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242x10-14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 8 immune proteins on postnatal day 5 (BDNF, C3, C5a, C9, IL-8, MCP-1, MIP-1β and MMP-9) when compared to preterm infants who were not exposed.ConclusionPreterm birth is associated with a distinct immune profile in umbilical cord blood and preterm infants exposed to HCA with evidence of a fetal inflammatory response have specific alterations in immune function that are apparent on day 5 of postnatal life
Christian Counsellors' Views on Working with Gay and Lesbian Clients:Integrating Religious Beliefs with Counselling Ethics
Thirty-one counsellors who identified themselves as practising, committed Christians, returned completed questionnaires that investigated how they integrate their Christian beliefs with their professional ethical code when counselling gay and lesbian clients. It was found that although most respondents believed that they were able to accept gay and lesbian clients, a minority demonstrated incongruence in relation to members of this client group, and were judgmental about perceived gay/lesbian behavious. Counsellors who took a rational stance in their understanding of the Bible and Christianity expressed more open and accepting views. Counsellors with a literalist approach to the Bible appeared to be lacking in acceptance and were unaware that they may not be offering the core condition of respect to their gay or lesbian clients. These findings are discussed in terms of their implications for supervision, research and practice
Association between preterm brain injury and exposure to chorioamnionitis during fetal life
Preterm infants are susceptible to inflammation-induced white matter injury but the exposures that lead to this are uncertain. Histologic chorioamnionitis (HCA) reflects intrauterine inflammation, can trigger a fetal inflammatory response, and is closely associated with premature birth. In a cohort of 90 preterm infants with detailed placental histology and neonatal brain magnetic resonance imaging (MRI) data at term equivalent age, we used Tract-based Spatial Statistics (TBSS) to perform voxel-wise statistical comparison of fractional anisotropy (FA) data and computational morphometry analysis to compute the volumes of whole brain, tissue compartments and cerebrospinal fluid, to test the hypothesis that HCA is an independent antenatal risk factor for preterm brain injury. Twenty-six (29%) infants had HCA and this was associated with decreased FA in the genu, cingulum cingulate gyri, centrum semiovale, inferior longitudinal fasciculi, limbs of the internal capsule, external capsule and cerebellum (p < 0.05, corrected), independent of degree of prematurity, bronchopulmonary dysplasia and postnatal sepsis. This suggests that diffuse white matter injury begins in utero for a significant proportion of preterm infants, which focuses attention on the development of methods for detecting fetuses and placentas at risk as a means of reducing preterm brain injury
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