Grass-Endophyte Interactions and Their Associated Alkaloids as a Potential Management Strategy for Plant Parasitic Nematodes.

Claviceptaceous endophytic fungi in the genus Epichloë mostly form a symbiotic relationship with cool-season grasses. Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes, which protect the host plant from herbivory by animals, insects, and nematodes. The host also benefits from enhanced tolerance to abiotic stresses, such as salt, drought, waterlogging, cold, heavy metals, and low nitrogen stress. The bioactive alkaloids produced can have both direct and indirect effects towards plant parasitic nematodes. Direct interaction with nematodes' motile stages can cause paralysis (nematostatic effect) or death (nematicidal effect). Indirectly, the metabolites may induce host immunity which inhibits feeding and subsequent nematode development. This review highlights the different mechanisms through which this interaction and the metabolites produced have been explored in the suppression of plant parasitic nematodes and also how the specific interactions between different grass genotypes and endophyte strains result in variable suppression of different nematode species. An understanding of the different grass-endophyte interactions and their successes and failures in suppressing various nematode species is essential to enable the proper selection of grass-endophyte combinations to identify the alkaloids produced, concentrations required, and determine which nematodes are sensitive to which specific alkaloids.

Trypanosoma cruzi screening in people living with HIV in the UK.

People living with HIV (PLWH) are at higher risk of reactivation of Chagas disease, a neglected tropical disease, caused by Trypanosoma cruzi. There are no data from UK HIV clinics on the prevalence of T. cruzi. We implemented T. cruzi screening at our clinic as part of routine care for PLWH with epidemiological risk factors. Among 86 patients screened, none had positive serology: one seropositive patient was identified due to increased clinician awareness. Implementing T. cruzi screening as part of routine clinical care was feasible, though labour intensive and identified at-risk individuals.

Screening of Fungicides and Comparison of Selective Media for Isolation of Fusarium graminearum from Soil and Plant Material.

The culture media recommended for the isolation and enumeration of the Fusarium spp. lack selectivity for Fusarium graminearum. Five fungicides-Amistar® (250 g·L-1 azoxystrobin), Filan® (500 g·kg-1 boscalid), Comet® 200 (200 g·L-1 pyraclostrobin), Imtrex® (62.5 g·L-1 fluxapyroxad), Poraz® (450 g·L-1 prochloraz)-were investigated for their potential as selective inhibitors in culture media for the isolation of F. graminearum from soil and plant material. Based on the screening, fluxapyroxad was further tested for selective inhibition for the isolation of F. graminearum from soil. Additionally, selective media were compared for the isolation of F. graminearum from plant material. The fungicides tested did not prove to be effective inhibitors for the development of selective media. For the detection of F. graminearum in plant material, Czapek Dox propiconazole dichloran agar was found to be a better medium than Komada's media, as the former resulted in colonies with darker pigmentation over a shorter incubation time and appeared to have a less inhibitory effect on F. graminearum growth.

Reduced Risk of Oat Grain Contamination with Fusarium langsethiae and HT-2 and T-2 Toxins with Increasing Tillage Intensity.

Frequent occurrences of high levels of Fusarium mycotoxins have been recorded in Norwegian oat grain. To elucidate the influence of tillage operations on the development of Fusarium and mycotoxins in oat grain, we conducted tillage trials with continuous oats at two locations in southeast Norway. We have previously presented the content of Fusarium DNA detected in straw residues and air samples from these fields. Grain harvested from ploughed plots had lower levels of Fusarium langsethiae DNA and HT-2 and T-2 toxins (HT2 + T2) compared to grain from harrowed plots. Our results indicate that the risk of F. langsethiae and HT2 + T2 contamination of oats is reduced with increasing tillage intensity. No distinct influence of tillage on the DNA concentration of Fusarium graminearum and Fusarium avenaceum in the harvested grain was observed. In contrast to F. graminearum and F. avenaceum, only limited contents of F. langsethiae DNA were observed in straw residues and air samples. Still, considerable concentrations of F. langsethiae DNA and HT2 + T2 were recorded in oat grain harvested from these fields. We speculate that the life cycle of F. langsethiae differs from those of F. graminearum and F. avenaceum with regard to survival, inoculum production and dispersal.

Pydiflumetofen Co-Formulated with Prothioconazole: A Novel Fungicide for Fusarium Head Blight and Deoxynivalenol Control.

Fusarium head blight (FHB) is an important disease of small grain cereals worldwide, resulting in reduced yield and quality as well as the contamination of harvested grains with mycotoxins. The key mycotoxin of concern is deoxynivalenol (DON), which has legislative and advisory limits in numerous countries. Cereal growers have a number of control options for FHB including rotation, cultivation, and varietal resistance; however, growers are still reliant on fungicides applied at flowering as part of an IPM program. Fungicides currently available to control FHB are largely restricted to triazole chemistry. This study conducted three field experiments to compare a new co-formulation of pydiflumetofen (a succinate dehydrogenase inhibitor (SDHI) with the tradename ADEPIDYN™) and prothioconazole (a triazole) against current standard fungicides at various timings (flag leaf fully emerged, mid-head emergence, early flowering, and late flowering) for the control of FHB and DON. Overall, the co-formulation showed greater efficacy compared to either pydiflumetofen alone or current fungicide chemistry. This greater activity was demonstrated over a wide range of spray timings (flag leaf fully emerged to late flowering). The availability of an SDHI with good activity against FHB and the resulting DON contamination of harvested grain will give growers an additional tool within an IPM program that will provide a greater flexibility of spray application windows and reduce fungicide resistance selection pressure.

Weather Patterns Associated with DON Levels in Norwegian Spring Oat Grain: A Functional Data Approach.

Fusarium graminearum is regarded as the main deoxynivalenol (DON) producer in Norwegian oats, and high levels of DON are occasionally recorded in oat grains. Weather conditions in the period around flowering are reported to have a high impact on the development of Fusarium head blight (FHB) and DON in cereal grains. Thus, it would be advantageous if the risk of DON contamination of oat grains could be predicted based on weather data. We conducted a functional data analysis of weather-based time series data linked to DON content in order to identify weather patterns associated with increased DON levels. Since flowering date was not recorded in our dataset, a mathematical model was developed to predict phenological growth stages in Norwegian spring oats. Through functional data analysis, weather patterns associated with DON content in the harvested grain were revealed mainly from about three weeks pre-flowering onwards. Oat fields with elevated DON levels generally had warmer weather around sowing, and lower temperatures and higher relative humidity or rain prior to flowering onwards, compared to fields with low DON levels. Our results are in line with results from similar studies presented for FHB epidemics in wheat. Functional data analysis was found to be a useful tool to reveal weather patterns of importance for DON development in oats.

Evidence for HIV-1 cure after CCR5Δ32/Δ32 allogeneic haemopoietic stem-cell transplantation 30 months post analytical treatment interruption: a case report.

BACKGROUND: The London patient (participant 36 in the IciStem cohort) underwent allogeneic stem-cell transplantation with cells that did not express CCR5 (CCR5Δ32/Δ32); remission was reported at 18 months after analytical treatment interruption (ATI). Here, we present longer term data for this patient (up to 30 months after ATI), including sampling from diverse HIV-1 reservoir sites. METHODS: We used ultrasensitive viral load assays of plasma, semen, and cerebrospinal fluid (CSF) samples to detect HIV-1 RNA. In gut biopsy samples and lymph-node tissue, cell-copy number and total HIV-1 DNA levels were quantified in multiple replicates, using droplet digital PCR (ddPCR) and quantitative real-time PCR. We also analysed the presence of intact proviral DNA using multiplex ddPCR targeting the packaging signal (ψ) and envelope (env). We did intracellular cytokine staining to measure HIV-1-specific T-cell responses. We used low-sensitive and low-avidity antibody assays to measure the humoral response to HIV-1. We predicted the probability of rebound using a mathematical model and inference approach. FINDINGS: HIV-1 viral load in plasma remained undetectable in the London patient up to 30 months (last tested on March 4, 2020), using an assay with a detection limit of 1 copy per mL. The patient's CD4 count was 430 cells per µL (23·5% of total T cells) at 28 months. A very low-level positive signal for HIV-1 DNA was recorded in peripheral CD4 memory cells at 28 months. The viral load in semen was undetectable in both plasma (lower limit of detection [LLD] <12 copies per mL) and cells (LLD 10 copies per 106 cells) at 21 months. CSF was within normal parameters at 25 months, with HIV-1 RNA below the detection limit (LLD 1 copy per mL). HIV-1 DNA by ddPCR was negative in rectum, caecum, and sigmoid colon and terminal ileum tissue samples at 22 months. Lymph-node tissue from axilla was positive for the long-terminal repeat (33 copies per 106 cells) and env (26·1 copies per 106 cells), negative for ψ and integrase, and negative by the intact proviral DNA assay, at 27 months. HIV-1-specific CD4 and CD8 T-cell responses have remained absent at 27 months. Low-avidity Env antibodies have continued to decline. Mathematical modelling suggests that the probability of remission for life (cure) is 98% in the context of 80% donor chimerism in total HIV target cells and greater than 99% probability of remission for life with 90% donor chimerism. INTERPRETATION: The London patient has been in HIV-1 remission for 30 months with no detectable replication-competent virus in blood, CSF, intestinal tissue, or lymphoid tissue. Donor chimerism has been maintained at 99% in peripheral T cells. We propose that these findings represent HIV-1 cure. FUNDING: Wellcome Trust and amfAR (American Foundation for AIDS Research).

HIV-1 remission following CCR5Δ32/Δ32 haematopoietic stem-cell transplantation.

A cure for HIV-1 remains unattainable as only one case has been reported, a decade ago1,2. The individual-who is known as the 'Berlin patient'-underwent two allogeneic haematopoietic stem-cell transplantation (HSCT) procedures using a donor with a homozygous mutation in the HIV coreceptor CCR5 (CCR5Δ32/Δ32) to treat his acute myeloid leukaemia. Total body irradiation was given with each HSCT. Notably, it is unclear which treatment or patient parameters contributed to this case of long-term HIV remission. Here we show that HIV-1 remission may be possible with a less aggressive and toxic approach. An adult infected with HIV-1 underwent allogeneic HSCT for Hodgkin's lymphoma using cells from a CCR5Δ32/Δ32 donor. He experienced mild gut graft-versus-host disease. Antiretroviral therapy was interrupted 16 months after transplantation. HIV-1 remission has been maintained over a further 18 months. Plasma HIV-1 RNA has been undetectable at less than one copy per millilitre along with undetectable HIV-1 DNA in peripheral CD4 T lymphocytes. Quantitative viral outgrowth assays from peripheral CD4 T lymphocytes show no reactivatable virus using a total of 24 million resting CD4 T cells. CCR5-tropic, but not CXCR4-tropic, viruses were identified in HIV-1 DNA from CD4 T cells of the patient before the transplant. CD4 T cells isolated from peripheral blood after transplantation did not express CCR5 and were susceptible only to CXCR4-tropic virus ex vivo. HIV-1 Gag-specific CD4 and CD8 T cell responses were lost after transplantation, whereas cytomegalovirus-specific responses were detectable. Similarly, HIV-1-specific antibodies and avidities fell to levels comparable to those in the Berlin patient following transplantation. Although at 18 months after the interruption of treatment it is premature to conclude that this patient has been cured, these data suggest that a single allogeneic HSCT with homozygous CCR5Δ32 donor cells may be sufficient to achieve HIV-1 remission with reduced intensity conditioning and no irradiation, and the findings provide further support for the development of HIV-1 remission strategies based on preventing CCR5 expression.

Impact of agronomic factors on fusarium mycotoxins in harvested wheat.

The aim of this study was to model fusarium mycotoxins against agronomic factors in order to identify those that have the greatest impact on mycotoxin levels in harvested wheat. To achieve this, fusarium mycotoxins levels were monitored, and associated agronomic data collected, in approximately 150 English wheat fields/year between 2006 and 2013. Results showed large seasonal variation in fusarium mycotoxin levels, with high levels in 2008 (13% and 29% exceeding legal limit for unprocessed soft wheat intended for human consumption for deoxynivalenol (DON) and zearalenone (ZON), respectively) and 2012 (10% and 15% exceeding legal limit for unprocessed soft wheat intended for human consumption for DON and ZON, respectively) and low levels in 2006 and 2011 (no samples exceeding legal limits for unprocessed soft wheat intended for human consumption for DON or ZON). Analysis of agronomic factors identified previous crop, cultivation and variety as the greatest risk factors. The greatest risk of mycotoxin development in grain was following maize as a previous crop and minimum tillage. The combined effect of these factors gave respective average DON and ZON levels 20 and 14 times higher than other previous crop and cultivation combinations. A newly quantified risk factor was harvest date. A 1-month delay in harvest resulted in a 10 and 25 times greater mean DON and ZON concentration, respectively, when compared to crops harvested around the long-term regional average harvest date. These results highlight the highly seasonal variation in fusarium mycotoxins in wheat and the agronomic factors that should be avoided to minimise fusarium mycotoxin levels in harvested wheat.

Missed opportunities for tuberculosis prevention among patients accessing a UK HIV service.

United Kingdom guidelines recommend screening for and treatment of latent tuberculosis infection (LTBI) in HIV-positive patients at high risk of active tuberculosis (TB) disease, but implementation is suboptimal. We investigated potential missed opportunities to identify and treat LTBI among HIV-positive patients accessing a large HIV outpatient service in London. Case records of all adult patients attending our service for HIV care diagnosed with active TB between 2011 and 2015 were reviewed to determine whether they met criteria for LTBI screening and whether screening was undertaken. Twenty-five patients were treated for TB. Of 15 (60%) patients who started TB treatment ≥6 months after HIV diagnosis, 14 (93%) met UK guideline-recommended criteria for LTBI screening and treatment; only one (7%) had been screened for LTBI. Eight of these 15 (53%) patients had additional risk factors for TB which are not reflected in current UK guidelines. Of 15 patients treated for TB ≥6 months after diagnosis of HIV, 14 (93%) had not been screened for LTBI, suggesting missed opportunities for TB prevention. People living with HIV may benefit from a broader approach to LTBI screening which takes into account additional recognised TB risk factors and ongoing TB exposure.

Impact of agronomic and climatic factors on the mycotoxin content of harvested oats in the United Kingdom.

A survey was conducted to determine the concentration of Fusarium mycotoxins in UK oats over three seasons (2006-8). One hundred oat samples were collected each year at harvest, together with agronomic details, and analysed for 10 Fusarium mycotoxins. The incidence and concentration of most Fusarium mycotoxins, including deoxynivalenol and zearalenone, were relatively low in oats compared with values previously reported for wheat. HT-2 toxin (HT2) and T-2 toxin (T2) levels were relatively high with an overall combined (HT2+T2) mean of 450 µg kg-1 for 2006-8. Data were combined with a previous dataset collected from 2002-5 to determine the effects of agronomic practices and climate. There was a negative relationship with late summer rainfall, indicating that drier conditions in July and August resulted in increased HT2 and T2 in UK oats. Agronomic factors that impacted upon HT2 and T2 in harvested oats were previous crop, cultivation, and variety. Analysis of the previous cropping history showed there was a stepwise increase in HT2+T2 as the cereal intensity of the rotation increased. Variety was an important factor, with higher levels and a wider range detected on winter versus spring varieties. Indicative levels for HT2 and T2 in cereals and cereal products were introduced by the EC in 2013. The indicative level for unprocessed oats for human consumption is a combined concentration (HT2+T2) of 1000 µg kg-1. From 2002 to 2008, between 1% and 30% of samples exceeded 1000 µg kg-1 HT2+T2 each year (overall mean, 16%). The introduction of European legislation on HT2 and T2 mycotoxins could have serious implications for UK oat production and oat-processing industries based on the levels detected within these studies.

Diffuse White Matter Signal Abnormalities on Magnetic Resonance Imaging Are Associated With Human Immunodeficiency Virus Type 1 Viral Escape in the Central Nervous System Among Patients With Neurological Symptoms.

Background: Human immunodeficiency virus type 1 (HIV-1) can replicate independently in extravascular compartments such as the central nervous system, resulting in either cerebrospinal fluid (CSF) discordance (viral load [VL] in CSF 0.5 log10 copies HIV-1 RNA greater than plasma VL) or escape (detection of HIV VL >50 copies/mL in CSF in patients with suppressed plasma VL <50 copies/mL). Both discordance and escape may be associated with neurological symptoms. We explored risk factors for CSF discordance and escape in patients presenting with diverse neurological problems. Methods: HIV-infected adult patients undergoing diagnostic lumbar puncture (LP) at a single center between 2011 and 2015 were included in the analysis. Clinical and neuroimaging variables associated with CSF discordance/escape were identified using multivariate logistic regression. Results: One hundred forty-six patients with a median age of 45.3 (interquartile range [IQR], 39.6-51.5) years underwent 163 LPs. Median CD4 count was 430 (IQR, 190-620) cells/µL. Twenty-four (14.7%) LPs in 22 patients showed CSF discordance, of which 10 (6.1%) LPs in 9 patients represented CSF escape. In multivariate analysis, both CSF discordance and escape were associated with diffuse white matter signal abnormalities (DWMSAs) on cranial magnetic resonance imaging (adjusted odds ratio, 10.3 [95% confidence interval {CI}, 2.3-45.0], P = .007 and 56.9 [95% CI, 4.0-882.8], P = .01, respectively). All 7 patients with CSF escape (10 LPs) had been diagnosed with HIV >7 years prior to LP, and 6 of 6 patients with resistance data had documented evidence of drug-resistant virus in plasma. Conclusions: Among patients presenting with diverse neurological problems, CSF discordance or escape was observed in 15%, with treatment-experienced patients dominating the escape group. DWMSAs in HIV-infected individuals presenting with neurological problems should raise suspicion of possible CSF discordance/escape.

High rate of lymphoma among a UK cohort of adolescents with vertically acquired HIV-1 infection transitioning to adult care in the era of antiretroviral therapy.

Among an inner London UK cohort of 147 adolescents transitioning from paediatric into adult care between 2007 and 2015, a new diagnosis of lymphoma was made in five patients; incidence rate = 0.425/100 person-years (95% confidence interval = 0.424-0.426). Previously described risk factors, including low nadir CD4 cell count and ongoing HIV-1 viraemia, appeared to be important. These data suggest that careful surveillance and a low threshold for investigating relevant symptoms continue to be essential for such patients.

Impact of post-anthesis rainfall, fungicide and harvesting time on the concentration of deoxynivalenol and zearalenone in wheat.

Field experiments were conducted to identify the impact of post-anthesis rainfall on the concentration of deoxynivalenol (DON) and zearalenone (ZON) in harvested wheat grain. Winter wheat plots were inoculated with Fusarium graminearum at stem extension (GS31) and prothioconazole was applied at mid-anthesis (GS65) to split plots and plots were subsequently mist irrigated for 5 days. Plots were either covered by polytunnels, irrigated by sprinklers or left as non-irrigated uncovered control plots after medium-milk (GS75). Plots were harvested either when ripe (GS92; early harvest) or three weeks later (late harvest). Fusarium head blight (FHB) was assessed each week from inoculation. At harvest, yield and grain quality was measured and grains were analysed for DON and ZON. Differences in rainfall resulted in contrasting disease pressure in the two experiments, with low FHB in the first experiment and high FHB in the second. Difference in FHB resulted in large differences in grain yield, quality and mycotoxin content. DON concentration was significantly (P < 0.05) higher in irrigated compared to covered and control plots in the first experiment, whereas in the second experiment, DON was significantly (P < 0.05) higher in the covered plots compared to the control and irrigated plots. ZON concentration was significantly (P < 0.05) higher in irrigated plots in both experiments. Later harvesting resulted in an approximate fivefold increase in ZON in the first experiment, but was not significantly different in the second experiment. Prothioconazole significantly (P < 0.05) reduced DON in both experiments, but gave inconsistent reductions to ZON. This is the first report to show that the post-anthesis rainfall can significantly increase ZON in wheat, which can increase further with a delayed harvest but may be significantly reduced with the application of prothioconazole. Importantly, in the absence of moisture late season, ZON remains at very low concentrations even when wheat is severely affected by FHB.

Genetic analysis reveals diversity and genetic relationship among Trichoderma isolates from potting media, cultivated soil and uncultivated soil.

BACKGROUND: Trichoderma is one of the most common fungi in soil. However, little information is available concerning the diversity of Trichoderma in soil with no previous history of cultivation. This study was conducted to investigate the most common species and the level of genetic relatedness of Trichoderma species from uncultivated soil in relation to cultivated soil and potting media. RESULTS: A total of 24, 15 and 13 Trichoderma isolates were recovered from 84 potting media samples, 45 cultivated soil samples and 65 uncultivated soil samples, respectively. Analysis based on the internal transcribed spacer region of the ribosomal RNA (rRNA) and the translation elongation factor gene (EF1) indicated the presence of 9 Trichoderma species: T. harzianum (16 isolates), T. asperellum (13), T. citrinoviride (9), T. orientalis (3), T. ghanense (3), T. hamatum (3), T. longibrachiatum (2), T. atroviride (2), and T. viride (1). All species were found to occur in potting media samples, while five Trichoderma species were recovered from the cultivated soils and four from the uncultivated soils. AFLP analysis of the 52 Trichoderma isolates produced 52 genotypes and 993 polymorphic loci. Low to moderate levels of genetic diversity were found within populations of Trichoderma species (H = 0.0780 to 0.2208). Analysis of Molecular Variance indicated the presence of very low levels of genetic differentiation (Fst = 0.0002 to 0.0139) among populations of the same Trichoderma species obtained from the potting media, cultivated soil and uncultivated soil. CONCLUSION: The study provides evidence for occurrence of Trichoderma isolates in soil with no previous history of cultivation. The lack of genetic differentiation among Trichoderma populations from potting media, cultivated soil and uncultivated soil suggests that some factors could have been responsible for moving Trichoderma propagules among the three substrates. The study reports for the first time the presence of 4 Trichoderma species in Oman: T. asperellum, T. ghanense, T. longibrachiatum and T. orientalis.

Proof-of-Principle for Immune Control of Global HIV-1 Reactivation In Vivo.

BACKGROUND: Emerging data relating to human immunodeficiency virus type 1 (HIV-1) cure suggest that vaccination to stimulate the host immune response, particularly cytotoxic cells, may be critical to clearing of reactivated HIV-1-infected cells. However, evidence for this approach in humans is lacking, and parameters required for a vaccine are unknown because opportunities to study HIV-1 reactivation are rare. METHODS: We present observations from a HIV-1 elite controller, not treated with combination antiretroviral therapy, who experienced viral reactivation following treatment for myeloma with melphalan and autologous stem cell transplantation. Mathematical modeling was performed using a standard viral dynamic model. Enzyme-linked immunospot, intracellular cytokine staining, and tetramer staining were performed on peripheral blood mononuclear cells; in vitro CD8 T-cell-mediated control of virion production by autologous CD4 T cells was quantified; and neutralizing antibody titers were measured. RESULTS: Viral rebound was measured at 28,000 copies/mL on day 13 post-transplant before rapid decay to <50 copies/mL in 2 distinct phases with t1/2 of 0.71 days and 4.1 days. These kinetics were consistent with an expansion of cytotoxic effector cells and killing of productively infected CD4 T cells. Following transplantation, innate immune cells, including natural killer cells, recovered with virus rebound. However, most striking was the expansion of highly functional HIV-1-specific cytotoxic CD8 T cells, at numbers consistent with those applied in modeling, as virus control was regained. CONCLUSIONS: These observations provide evidence that the human immune response is capable of controlling coordinated global HIV-1 reactivation, remarkably with potency equivalent to combination antiretroviral therapy. These data will inform design of vaccines for use in HIV-1 curative interventions.

A framework to determine the effectiveness of dietary exposure mitigation to chemical contaminants.

In order to ensure the food safety, risk managers may implement measures to reduce human exposure to contaminants via food consumption. The evaluation of the effect of a measure is often an overlooked step in risk analysis process. The aim of this study was to develop a systematic approach for determining the effectiveness of mitigation measures to reduce dietary exposure to chemical contaminants. Based on expert opinion, a general framework for evaluation of the effectiveness of measures to reduce human exposure to food contaminants was developed. The general outline was refined by application to three different cases: 1) methyl mercury in fish and fish products, 2) deoxynivalenol in cereal grains, and 3) furan in heated products. It was found that many uncertainties and natural variations exist, which make it difficult to assess the impact of the mitigation measure. Whenever possible, quantitative methods should be used to describe the current variation and uncertainty. Additional data should be collected to cover natural variability and reduce uncertainty. For the time being, it is always better for the risk manager to have access to all available information, including an assessment of uncertainty; however, the proposed methodology provides a conceptual framework for addressing these systematically.

A declining CD4 count and diagnosis of HIV-associated Hodgkin lymphoma: do prior clinical symptoms and laboratory abnormalities aid diagnosis?

BACKGROUND: The incidence of Hodgkin lymphoma (HL) among HIV-infected individuals remains unchanged since the introduction of combination antiretroviral therapy (cART). Recent epidemiological data suggest that CD4 count decline over a year is associated with subsequent diagnosis of HL. In an era of economic austerity monitoring the efficacy of cART by CD4 counts may no longer be required where CD4 count>350 cells/µl and viral load is suppressed (<50 copies/ml). METHODS: We sought to establish among our HIV outpatient cohort whether a CD4 count decline prior to diagnosis of HL, whether any decline was greater than in patients without the diagnosis, and also whether other clinical or biochemical indices were reliably associated with the diagnosis. RESULTS: Twenty-nine patients with a diagnosis of HL were identified. Among 15 individuals on cART with viral load <50 copies/ml the change in CD4 over 12 months preceding diagnosis of HL was -82 cells/µl (95% CI -163 to -3; p = 0.04). Among 18 matched controls the mean change was +5 cells/µl, 95% CI -70 to 80, p = 0.89). The decline in CD4 over the previous 6-12 months was somewhat greater in cases than controls (mean difference in change -55 cells/µl, 95% CI -151 to 39; p = 0.25). In 26 (90%) patients B symptoms had been present for a median of three months (range one-12) before diagnosis of HL. CONCLUSIONS: The CD4 count decline in the 12 months prior to diagnosis of Hodgkin lymphoma among HIV-infected individuals with VL<50 copies/ml on cART was not significantly different from that seen in other fully virologically suppressed individuals in receipt of cART and who did not develop HL. All those who developed HL had B symptoms and/or new palpable lymphadenopathy, suggesting that CD4 count monitoring if performed less frequently, or not at all, among those virologically suppressed individuals with CD4 counts >350 may not have delayed diagnosis.

Modeling the effects of environmental conditions on HT2 and T2 toxin accumulation in field oat grains.

Fusarium head blight (FHB) of wheat and barley has been extensively researched worldwide; in contrast, there is limited information on the effects of environmental conditions on Fusarium toxin accumulation in oat grains. More than 300 samples of oat grain from various regions of the United Kingdom from 2006 to 2008 were analyzed for mycotoxin contamination due to infection by Fusarium spp. HT2 and T2 toxins were the two most commonly detected, and their concentrations in individual samples were highly correlated. Hourly weather data were obtained from meteorological recording stations near most of the sampling sites. Statistical modeling was applied to both the original toxin (HT2 plus T2) data and the toxin data adjusted for oat cultivars and number of cereal crops in the previous four seasons. Accumulation of HT2 and T2 toxin was positively correlated with warm and wet conditions during early May and dry conditions thereafter. Using a collection of 51 environmental variables summarized over three lengths (10, 15, and 20 days) of time periods encompassing early May, late May, and early July, all-subsets regression showed that many models, consisting of three to six predictor variables, could be identified with similar explanatory strength for the effect of environmental conditions on toxin accumulation. Most important predictor variables were related to wet conditions during the early-May period, which was before anthesis. These results suggest that the predominant period for Fusarium langsethiae infection of oat is likely to be before rather than during anthesis, as for other head blight pathogens. These empirical models may be further improved by using quantified pathogen biomass within the grains and weather predictor variables summarized in relation to plant growth stages (instead of calendar times).

Prevalence of vitamin D deficiency in HIV-positive, antiretroviral treatment-naïve patients in a single centre study.

The objective of this study was to describe the prevalence of vitamin D deficiency among antiretroviral treatment-naïve, HIV-positive individuals. We reviewed records of consecutive antiretroviral treatment-naïve patients, registering for care for the first time at a London clinic from 01 January 2008 to 31 December 2009. During this period, serum 25-hydroxycholecalciferol was measured routinely for all new patients. 25-hydroxycholecalciferol deficiency and severe deficiency were defined as ≤50 and ≤25 nmol/L, respectively. Among 253 patients (82% men, median age 36 years, 64% white ethnicity), 148 (58.5%) were 25-hydroxycholecalciferol-deficient, including 32 (12.6%) who were severely deficient. In all, 73.5% (61/83) patients of non-white ethnicity were 25-hydroxycholecalciferol-deficient compared with 50.7% (76/150) of those reporting white ethnicity (p < 0.001). Seven of eight (87.5%) patients with hypocalcaemia (<2.12 nmol/L) were 25-hydroxycholecalciferol-deficient. The prevalence of 25-hydroxycholecalciferol-deficiency was higher in winter and spring vs. summer and autumn (89/129 [69.0%] vs. 59/124 [47.6%],p < 0.001). Serum 25-hydroxycholecalciferol deficiency was not associated with gender, CD4 count, HIV viral load or clinical stage. Serum 25-hydroxycholecalciferol deficiency was common among antiretroviral treatment-naïve patients, with those of non-white ethnicity at highest risk. CD4 count, HIV viral load and HIV clinical staging do not help to identify those at risk, but low serum calcium should prompt investigation of 25-hydroxycholecalciferol levels.