Differential Cellular Distribution of HIV-1 Drug Resistance in Vivo: Evidence for Infection of CD8+ T Cells during HAART

AbstractThis study presents a detailed analysis of HIV-1 populations isolated from total PBMC, plasma, CD4+ T cells, CD8+ T cells, and monocytes/macrophages in 13 patients receiving HAART. Sequence analysis of the reverse transcriptase and protease genes indicated that viral strains isolated from different blood leukocytes were genetically distinct in each subject. Notably, HIV variants isolated from CD8+ T cells were distantly related to strains derived from other blood cell types, providing evidence for the strain-specific infection of CD8+ T cells in vivo. Compartmentalization of drug resistance mutations in specific blood cell types was observed in approximately 50% of patients. The prevalence of resistance mutations was higher in either CD4+ T cells or monocytes/macrophages in these subjects. However, CD8+ T cells showed markedly lower levels of viral drug resistance in these patients, indicating a lack of viral replication in this compartment. This study is the first to demonstrate the differential distribution of HIV drug resistance in different blood cell types during HAART and provides new insights into the infection of CD8+ T cells in vivo

Licking microstructure and hedonic changes after flavour preference learning in rats

Pairing a neutral flavour conditioned stimulus (CS) with a nutrient reward will create a learned preference for that CS. Prior studies suggest that this is accompanied by an increase in the hedonic value of the CS, although the reliability of this effect is yet to be fully established. Here, flavour CS+s were mixed with either 16% sucrose or maltodextrin (with control CS-s mixed with 2% solutions of the same carbohydrate). While a reliable preference for the CS+ was seen in every case, and there was a learned increase in lick cluster size when all conditions were considered together, this difference was significant in only one experimental condition considered alone. A meta-analysis of these results and similar published licking microstructure analysis studies found that the Cohen’s dav effect size for changes in licking microstructure after flavour preference learning was 0.16. This is far smaller than the effect sizes reported when assessing learned hedonic changes in flavour preference based on other test or training methods. Although this confirms that flavour preference learning produces hedonic changes in the cue flavours, the analysis of licking microstructure with training based on voluntary consumption of CS and unconditioned stimulus (US) compounds may be an insensitive means of assessing such effects

Measurement of Epstein-Barr virus DNA load using a novel quantification standard containing two EBV DNA targets and SYBR Green I dye

BACKGROUND Reactivation of Epstein-Barr virus (EBV) infection may cause serious, life-threatening complications in immunocompromised individuals. EBV DNA is often detected in EBV-associated disease states, with viral load believed to be a reflection of virus activity. Two separate real-time quantitative polymerase chain reaction (QPCR) assays using SYBR Green I dye and a single quantification standard containing two EBV genes, Epstein-Barr nuclear antigen-1 (EBNA-1) and BamHI fragment H rightward open reading frame-1 (BHRF-1), were developed to detect and measure absolute EBV DNA load in patients with various EBV-associated diseases. EBV DNA loads and viral capsid antigen (VCA) IgG antibody titres were also quantified on a population sample. RESULTS EBV DNA was measurable in ethylenediaminetetraacetic acid (EDTA) whole blood, peripheral blood mononuclear cells (PBMCs), plasma and cerebrospinal fluid (CSF) samples. EBV DNA loads were detectable from 8.0 × 10² to 1.3 × 10⁸ copies/ml in post-transplant lymphoproliferative disease (n = 5), 1.5 × 10³ to 2.0 × 10⁵ copies/ml in infectious mononucleosis (n = 7), 7.5 × 10⁴ to 1.1 × 10⁵ copies/ml in EBV-associated haemophagocytic syndrome (n = 1), 2.0 × 10² to 5.6 × 10³ copies/ml in HIV-infected patients (n = 12), and 2.0 × 10² to 9.1 × 10⁴ copies/ml in the population sample (n = 218). EBNA-1 and BHRF-1 DNA were detected in 11.0% and 21.6% of the population sample respectively. There was a modest correlation between VCA IgG antibody titre and BHRF-1 DNA load (rho = 0.13, p = 0.05) but not EBNA-1 DNA load (rho = 0.11, p = 0.11). CONCLUSION Two sensitive and specific real-time PCR assays using SYBR Green I dye and a single quantification standard containing two EBV DNA targets, were developed for the detection and measurement of EBV DNA load in a variety of clinical samples. These assays have application in the investigation of EBV-related illnesses in immunocompromised individuals.The Ausimmune Study is funded by the National Multiple Sclerosis Society of the USA, the National Health & Medical Research Council (Project Grant 316901) and Multiple Sclerosis Research Australia

Using patient-collected clinical samples and sera to detect and quantify the severe acute respiratory syndrome coronavirus (SARS-CoV)

BACKGROUND: Severe acute respiratory syndrome (SARS) caused a large outbreak of pneumonia in Beijing, China, in 2003. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect and quantify SARS-CoV in 934 sera and self-collected throat washes and fecal samples from 271 patients with laboratory-confirmed SARS managed at a single institution. RESULTS: SARS-CoV detection rates in sera were highest in the first 9 days of illness, whereas detection was highest in throat washes 5–14 days after onset of symptoms. The highest SARS-CoV RT-PCR rates (70.4–86.3%) and viral loads (log(10 )4.5–6.1) were seen in fecal samples collected 2–4 weeks after the onset of clinical illness. Fecal samples were frequently SARS-CoV RT-PCR positive beyond 40 days, and occasional sera still had SARS-CoV detected after 3 weeks of illness. CONCLUSION: In the context of an extensive outbreak with major pressure on hospital resources, patient self-collected samples are an alternative to nasopharyngeal aspirates for laboratory confirmation of SARS-CoV infection

Treating and Preventing Influenza in Aged Care Facilities: A Cluster Randomised Controlled Trial

PMCID: PMC3474842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

HIV-1 gp120 N-linked glycosylation differs between plasma and leukocyte compartments

<p>Abstract</p> <p>Background</p> <p>N-linked glycosylation is a major mechanism for minimizing virus neutralizing antibody response and is present on the Human Immunodeficiency Virus (HIV) envelope glycoprotein. Although it is known that glycosylation changes can dramatically influence virus recognition by the host antibody, the actual contribution of compartmental differences in N-linked glycosylation patterns remains unclear.</p> <p>Methodology and Principal Findings</p> <p>We amplified the <it>env </it>gp120 C2-V5 region and analyzed 305 clones derived from plasma and other compartments from 15 HIV-1 patients. Bioinformatics and Bayesian network analyses were used to examine N-linked glycosylation differences between compartments. We found evidence for cellspecific single amino acid changes particular to monocytes, and significant variation was found in the total number of N-linked glycosylation sites between patients. Further, significant differences in the number of glycosylation sites were observed between plasma and cellular compartments. Bayesian network analyses showed an interdependency between N-linked glycosylation sites found in our study, which may have immense functional relevance.</p> <p>Conclusion</p> <p>Our analyses have identified single cell/compartment-specific amino acid changes and differences in N-linked glycosylation patterns between plasma and diverse blood leukocytes. Bayesian network analyses showed associations inferring alternative glycosylation pathways. We believe that these studies will provide crucial insights into the host immune response and its ability in controlling HIV replication <it>in vivo</it>. These findings could also have relevance in shielding and evasion of HIV-1 from neutralizing antibodies.</p

A Critical Role for the Hippocampus and Perirhinal Cortex in Perceptual Learning of Scenes and Faces: Complementary Findings from Amnesia and fMRI

It is debated whether subregions within the medial temporal lobe (MTL), in particular the hippocampus (HC) and perirhinal cortex (PrC), play domain-sensitive roles in learning. In the present study, two patients with differing degrees of MTL damage were first exposed to pairs of highly similar scenes, faces, and dot patterns and then asked to make repeated same/different decisions to preexposed and nonexposed (novel) pairs from the three categories (Experiment 1). We measured whether patients would show a benefit of prior exposure (preexposed > nonexposed) and whether repetition of nonexposed (and preexposed) pairs at test would benefit discrimination accuracy. Although selective HC damage impaired learning of scenes, but not faces and dot patterns, broader MTL damage involving the HC and PrC compromised discrimination learning of scenes and faces but left dot pattern learning unaffected. In Experiment 2, a similar task was run in healthy young participants in the MRI scanner. Functional region-of-interest analyses revealed that posterior HC and posterior parahippocampal gyrus showed greater activity during scene pattern learning, but not face and dot pattern learning, whereas PrC, anterior HC, and posterior fusiform gyrus were recruited during discrimination learning for faces, but not scenes and dot pattern learning. Critically, activity in posterior HC and PrC, but not the other functional region-of-interest analyses, was modulated by accuracy (correct > incorrect within a preferred category). Therefore, both approaches revealed a key role for the HC and PrC in discrimination learning, which is consistent with representational accounts in which subregions in these MTL structures store complex spatial and object representations, respectively

Influenza vaccination among Australian Hajj pilgrims: uptake, attitudes, and barriers

Background: Hajj is the largest annual mass gathering where the risk of respiratory infection is high. Although the Saudi Arabian authority recommends influenza vaccination for Hajj pilgrims, the uptake is variable. Influenza vaccine uptake data among Australian Hajj pilgrims is not readily available. Therefore, we aimed to estimate the influenza vaccination uptake rate and identify both attitudes and barriers to vaccine uptake from two consecutives surveys at Hajj in 2011 and 2012. Methods: Using an anonymous self‐administered questionnaire, surveys were conducted in Mecca, Saudi Arabia, among Hajj pilgrims from Australia in 2011 and 2012. Pilgrims staying in “Australian” tents were recruited serially. Results: In 2011, 431 Australian pilgrims completed the survey—median age was 42 (range 7–86) years, 55% were male; 65% reported receiving influenza vaccine. In 2012, 535 pilgrims of median age 43 (range 12–83) years completed the survey, 62% were male; 89% reported receiving the vaccine. Both in 2011 and 2012, common reasons for not receiving the vaccine were the pilgrims' reliance on their “natural immunity” (33 and 26%, respectively, p = 0.4) and believing that they would rarely catch influenza or come in contact with influenza patients (18 and 29%, respectively, p = 0.1). In 2012, when asked why they had received the vaccine, 65% pilgrims responded that it was because of the tour group leaders' recommendation. Conclusion: Influenza vaccine uptake among Australian Hajj pilgrims seems satisfactory and increasing but could be better because many pilgrims have misconceptions about vaccines. Tour operators may play a greater role in promoting vaccination