Enhancing the efficacy of TCR gene therapy

TCR gene therapy allows redirection of the antigen specificity of T cells by the introduction of novel TCR α and β chains by retroviral transduction. These TCR gene modified T cells can be adoptively transferred to target defined tumour antigens. The majority of TCR gene therapy studies has focused on the adoptive transfer of CD8+ T cells but there is increasing recognition of a central role for CD4+ T cells in effective immunotherapy protocols. The use of CD4+ T cells has been limited by the lack of well defined class II restricted TCR and also because the majority of tumours don’t express class II MHC. As a result research has focused on introducing class I restricted TCR into CD4+ T cells. Initial work has demonstrated that class I restricted CD4+ T cells often have reduced functional avidity compared to the parental CD8+ T cell. In particular, CD4+ T cells transduced with CD8 dependent TCRs are often of much lower functional avidity when introduced in the absence of a CD8 co-receptor. In order to improve the functional avidity of class I restricted CD4+ T cells, murine CD4+ T cells were co-transduced with F5 TCR (specific for influenza peptide, NP, in the context of H2-Kb) and additional CD3 molecules. The amount of CD3 within in a cell is rate limiting for the expression of introduced TCR and thus when cells are transduced with additional CD3 it removes this rate limiting step and thus enhances the surface expression of the TCR. TCR surface expression is one of the key determinants of T cell functional avidity. CD4+ T cells co-transduced with F5- TCR and CD3 had increased surface expression of F5-TCR and increased pentamer binding. This translated in vitro into increased functional avidity compared to CD4+ T cells transduced with F5-TCR only. When adoptively transferred in vivo into irradiated tumour bearing syngeneic recipients, F5- TCR + CD3 CD4+ T cells had greater expansion and persistence and trafficked to the tumour site at higher and faster rates than F5-TCR only CD4+ T cells. In addition, F5-CD3 CD4+ T cells demonstrated superior control of tumour growth. Unexpectedly mice that received adoptive transfer of F5-TCR + CD3 CD4+ T cells developed marked lethal toxicity. Further experiments to try to determine the nature of this toxicity suggest a multifactorial cause including mispairing of the introduced TCR α and β chains with the endogenous TCR and development of autoreactive T cells in the presence of additional CD3 mediated either by upregulation of the introduced TCR or the endogenous TCR

The 1983 drought in the West Sahel: a case study

Some drought years over sub-Saharan west Africa (1972, 1977, 1984) have been previously related to a cross-equatorial Atlantic gradient pattern with anomalously warm sea surface temperatures (SSTs) south of 10°N and anomalously cold SSTs north of 10°N. This SST dipole-like pattern was not characteristic of 1983, the third driest summer of the twentieth century in the Sahel. This study presents evidence that the dry conditions that persisted over the west Sahel in 1983 were mainly forced by high Indian Ocean SSTs that were probably remanent from the strong 1982/1983 El Niño event. The synchronous Pacific impact of the 1982/1983 El Niño event on west African rainfall was however, quite weak. Prior studies have mainly suggested that the Indian Ocean SSTs impact the decadal-scale rainfall variability over the west Sahel. This study demonstrates that the Indian Ocean also significantly affects inter-annual rainfall variability over the west Sahel and that it was the main forcing for the drought over the west Sahel in 1983

A Growth Model for North Queensland Rainforests

A model to predict the growth of commercial timber in north Queensland's rainforests is described. More than 100 commercial species and several hundred other tree species are aggregated into about 20 species groups based on growth habit, volume relationships and commercial criteria. Trees are grouped according to species group and tree size into cohorts, which form the basis for simulation. Equations for predicting increment, mortality and recruitment are presented. The implications of the model on rainforest management for timber production are examined. The model has been used in setting the timber harvest from these rainforests, and should provide an objective basis for investigating the impact of rainforest management strategies. The approach should be applicable to other indigenous forests

Human Rhinovirus Infections in Rural Thailand: Epidemiological Evidence for Rhinovirus as Both Pathogen and Bystander

BACKGROUND: We describe human rhinovirus (HRV) detections in SaKaeo province, Thailand. METHODS: From September 1, 2003-August 31, 2005, we tested hospitalized patients with acute lower respiratory illness and outpatient controls without fever or respiratory symptoms for HRVs with polymerase chain reaction and molecularly-typed select HRVs. We compared HRV detection among hospitalized patients and controls and estimated enrollment adjusted incidence. RESULTS: HRVs were detected in 315 (16%) of 1919 hospitalized patients and 27 (9.6%) of 280 controls. Children had the highest frequency of HRV detections (hospitalized: <1 year: 29%, 1-4 year: 29%, ≥ 65 years: 9%; controls: <1 year: 24%, 1-4 year: 14%, ≥ 65 years: 2.8%). Enrollment adjusted hospitalized HRV detection rates were highest among persons aged <1 year (1038/100,000 persons/year), 1-4 years (457), and ≥ 65 years (71). All three HRV species were identified, HRV-A was the most common species in most age groups including children aged <1 year (61%) and all adult age groups. HRV-C was the most common species in the 1-4 year (51%) and 5-19 year age groups (54%). Compared to controls, hospitalized adults (≥ 19 years) and children were more likely to have HRV detections (odds ratio [OR]: 4.8, 95% confidence interval [CI]: 1.5, 15.8; OR: 2.0, CI: 1.2, 3.3, respectively) and hospitalized children were more likely to have HRV-A (OR 1.7, CI: 0.8, 3.5) or HVR-C (OR 2.7, CI: 1.2, 5.9) detection. CONCLUSIONS: HRV rates were high among hospitalized children and the elderly but asymptomatic children also had substantial HRV detection. HRV (all species), and HRV-A and HRV-C detections were epidemiologically-associated with hospitalized illness. Treatment or prevention modalities effective against HRV could reduce hospitalizations due to HRV in Thailand

A reference frame for blood volume in children and adolescents

BACKGROUND: Our primary purpose was to determine the normal range and variability of blood volume (BV) in healthy children, in order to provide reference values during childhood and adolescence. Our secondary aim was to correlate these vascular volumes to body size parameters and pubertal stages, in order to determine the best normalisation parameter. METHODS: Plasma volume (PV) and red cell volume (RCV) were measured and F-cell ratio was calculated in 77 children with idiopathic nephrotic syndrome in drug-free remission (mean age, 9.8 ± 4.6 y). BV was calculated as the sum of PV and RCV. Due to the dependence of these values on age, size and sex, all data were normalised for body size parameters. RESULTS: BV normalised for lean body mass (LBM) did not differ significantly by sex (p < 0.376) or pubertal stage (p < 0.180), in contrast to normalisation for the other anthropometric parameters. There was no significant difference between reference values for children and adults. CONCLUSION: LBM was the anthropometric index most closely correlated to vascular fluid volumes, independent of age, gender and pubertal stage

Early and extensive CD55 loss from red blood cells supports a causal role in malarial anaemia

BACKGROUND\ud \ud Levels of complement regulatory proteins (CrP) on the surface of red blood cells (RBC) decrease during severe malarial anaemia and as part of cell ageing process. It remains unclear whether CrP changes seen during malaria contribute to the development of anaemia, or result from an altered RBC age distribution due to suppressive effects of malaria on erythropoiesis.\ud \ud METHODS\ud \ud A cross sectional study was conducted in the north-east coast of Tanzania to investigate whether the changes in glycosylphosphatidylinositol (GPI)-anchored complement regulatory proteins (CD55 and CD59) contributes to malaria anaemia. Blood samples were collected from a cohort of children under intensive surveillance for Plasmodium falciparum parasitaemia and illness. Levels of CD55 and CD59 were measured by flow cytometer and compared between anaemic (8.08 g/dl) and non- anaemic children (11.42 g/dl).\ud \ud RESULTS\ud \ud Levels of CD55 and CD59 decreased with increased RBC age. CD55 levels were lower in anaemic children and the difference was seen in RBC of all ages. Levels of CD59 were lower in anaemic children, but these differences were not significant. CD55, but not CD59, levels correlated positively with the level of haemoglobin in anaemic children.\ud \ud CONCLUSION\ud \ud The extent of CD55 loss from RBC of all ages early in the course of malarial anaemia and the correlation of CD55 with haemoglobin levels support the hypothesis that CD55 may play a causal role in this disorder

Rapid semi-automated quantitative multiplex tandem PCR (MT-PCR) assays for the differential diagnosis of influenza-like illness

<p>Abstract</p> <p>Background</p> <p>Influenza A, including avian influenza, is a major public health threat in developed and developing countries. Rapid and accurate detection is a key component of strategies to contain spread of infection, and the efficient diagnosis of influenza-like-illness is essential to protect health infrastructure in the event of a major influenza outbreak.</p> <p>Methods</p> <p>We developed a multiplexed PCR (MT-PCR) assay for the simultaneous diagnosis of respiratory viruses causing influenza-like illness, including the specific recognition of influenza A haemagglutinin subtypes H1, H3, and H5. We tested several hundred clinical specimens in two diagnostic reference laboratories and compared the results with standard techniques.</p> <p>Results</p> <p>The sensitivity and specificity of these assays was higher than individual assays based on direct antigen detection and standard PCR against a range of control templates and in several hundred clinical specimens. The MT-PCR assays provided differential diagnoses as well as potentially useful quantitation of virus in clinical samples.</p> <p>Conclusions</p> <p>MT-PCR is a potentially powerful tool for the differential diagnosis of influenza-like illness in the clinical diagnostic laboratory.</p

Can I cut it? Medical students' perceptions of surgeons and surgical careers

Abstract Background Recent years have seen a significant drop in applications to surgical residencies. Existing research has yet to explain how medical students make career decisions. This qualitative study explores students' perceptions of surgery and surgeons, and the influence of stereotypes on career decisions. Methods Exploratory questionnaires captured students' perceptions of surgeons and surgery. Questionnaire data informed individual interviews, exploring students' perceptions in depth. Rigorous qualitative interrogation of interviews identified emergent themes from which a cohesive analysis was synthesized. Results Respondents held uniform stereotypes of surgeons as self-confident and intimidating; surgery was competitive, masculine, and required sacrifice. To succeed in surgery, students felt they must fit these stereotypes, excluding those unwilling, or who felt unable, to conform. Deviating from the stereotypes required displaying such characteristics to a level exceptional even for surgery; consequently, surgery was neither an attractive nor realistic career option. Conclusions Strong stereotypes of surgery deterred students from a surgical career. As a field, surgery must actively engage medical students to encourage participation and dispel negative stereotypes that are damaging recruitment into surgery

1H-NMR-Based Metabolic Profiling of Maternal and Umbilical Cord Blood Indicates Altered Materno-Foetal Nutrient Exchange in Preterm Infants

Background: Adequate foetal growth is primarily determined by nutrient availability, which is dependent on placental nutrient transport and foetal metabolism. We have used 1H nuclear magnetic resonance (NMR) spectroscopy to probe the metabolic adaptations associated with premature birth. Methodology: The metabolic profile in 1H NMR spectra of plasma taken immediately after birth from umbilical vein, umbilical artery and maternal blood were recorded for mothers delivering very-low-birth-weight (VLBW) or normo-ponderal full-term (FT) neonates. Principal Findings: Clear distinctions between maternal and cord plasma of all samples were observed by principal component analysis (PCA). Levels of amino acids, glucose, and albumin-lysyl in cord plasma exceeded those in maternal plasma, whereas lipoproteins (notably low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) and lipid levels were lower in cord plasma from both VLBW and FT neonates. The metabolic signature of mothers delivering VLBW infants included decreased levels of acetate and increased levels of lipids, pyruvate, glutamine, valine and threonine. Decreased levels of lipoproteins glucose, pyruvate and albumin-lysyl and increased levels of glutamine were characteristic of cord blood (both arterial and venous) from VLBW infants, along with a decrease in levels of several amino acids in arterial cord blood. Conclusion: These results show that, because of its characteristics and simple non-invasive mode of collection, cord plasma is particularly suited for metabolomic analysis even in VLBW infants and provides new insights into the materno-foetal nutrient exchange in preterm infants