Human parvovirus 4 'PARV4' remains elusive despite a decade of study

Human parvovirus 4 ('PARV4') is a small DNA tetraparvovirus, first reported in 2005. In some populations, PARV4 infection is uncommon, and evidence of exposure is found only in individuals with risk factors for parenteral infection who are infected with other blood-borne viruses. In other settings, seroprevalence studies suggest an endemic, age-associated transmission pattern, independent of any specific risk factors. The clinical impact of PARV4 infection remains uncertain, but reported disease associations include an influenza-like syndrome, encephalitis, acceleration of HIV disease, and foetal hydrops. In this review, we set out to report progress updates from the recent literature, focusing on the investigation of cohorts in different geographical settings, now including insights from Asia, the Middle East, and South America, and discussing whether attributes of viral or host populations underpin the striking differences in epidemiology. We review progress in understanding viral phylogeny and biology, approaches to diagnostics, and insights that might be gained from studies of closely related animal pathogens. Crucial questions about pathogenicity remain unanswered, but we highlight new evidence supporting a possible link between PARV4 and an encephalitis syndrome. The unequivocal evidence that PARV4 is endemic in certain populations should drive ongoing research efforts to understand risk factors and routes of transmission and to gain new insights into the impact of this virus on human health

Synthesis And Behavioral Studies Of Chiral Cyclopropanes As Selective α4β2-Nicotinic Acetylcholine Receptor Partial Agonists Exhibiting An Antidepressant Profile. Part Iii

We report the synthesis and biological characterization of novel derivatives of 3-[(1-methyl-2(S)-pyrrolidinyl)methoxy]-5-cyclopropylpyridine (4a-f and 5) as potent and highly selective α4β2-nicotinic acetylcholine receptor (nAChR) full or partial agonists. A systematic structure-activity study was carried out on the previously described compound 3b, particularly concerning its (2-methoxyethyl)cyclopropyl side-chain, in an effort to improve its metabolic stability while maintaining receptor selectivity. Compound 4d exhibited very similar subnanomolar binding affinity for α4β2- and α4β2∗-nAChRs compared to 3b, and it showed excellent potency in activating high-sensitivity (HS) α4β2-nAChRs with an EC 50 value of 8.2 nM. Testing of 4d in the SmartCube assay revealed that the compound has a combined antidepressant plus antipsychotic signature. In the forced swim test at a dose of 30 mg/kg given intraperitoneally, 4d was found to be as efficacious as sertraline, thus providing evidence of the potential use of the compound as an antidepressant. Additional promise for use of 4d in humans comes from pharmacokinetic studies in mice indicating brain penetration, and additional assays show compound stability in the presence of human microsomes and hepatocytes. Thus, 4d has a very favorable preclinical drug profile

Mucorles-specific T cells emerge in the course of invasive mucormucosis and may be used as a surrogate diagnostic marker in high-risk patients

Mucorales-specific T cells have been investigated in 28 hematologic patients during the course of their treatment. Three developed proven invasive mucormycosis (IM), 17 infections of known etiologies but other than IM, and 8 never showed fever upon the period of observation. The Mucorales-specific T cells may be detected only in patients with IM, at diagnosis and along the entire course of the IM, but neither before nor long time after the resolution of the infection. Such T cells produced predominantly interleukin-4, interferon-gamma (IFN-γ), interleukin-10, and to a lesser extent also interleukin-17, and belonged to either CD4+ or CD8+ subsets. The specific T cells producing IFN-γ were able to directly induce damage of Mucorales hyphae. None of the 25 patients without IM showed Mucorales-specific T cells. Specific T cells contribute to human immune responses against fungi of the order Mucorales and could be evaluated as a surrogate diagnostic marker of IM

Identification and characterization of Aspergillus-specific immune responses to diagnose invasive aspergillosis in high risk patients: a multicenter study

Background. The mortality of Invasive Aspergillosis (IA) still affects from 27% to 55% of high risk hematologic patients. The reasons of such a poor outcome also rely on several drawbacks limiting the di- agnostic accuracy of non cultural based diagnostic methods (NCBDM) and hampering the opportunities for an early intervention. Studies in mice model of IA and in healthy subjects have shown that Aspergillus-specific T-cells producing interferon-gamma (IFN- gamma-T1) are protective, while Aspergillus-specific T-cells pro- ducing interleukin-10 (IL-10-T2) are non-protective to IA. Aims. We have investigated whether the identification of Aspergillus-specific IFN-gamma-T1 and/or IL-10-T2 through an ex-vivo enzyme linked immunospot (ELISPOT) assay may be effective in the diagnosis of IA in high risk patients. Furthermore, in the proven IA patients, we have functionally and phenotipically characterized such T cells through the cytokine secretion assay (CSA). Methods. 180 patients (168 hemato- logic and 12 solid organ transplant patients) have been enrolled. They were classified, according the revised EORTC/MSG criteria, as fol- lows: 18 proven, 35 probable, 17 possible IA cases and 110 controls. The control patients were divided in two groups: group 1 included 86 (78.2%) patients with hystological and/or cultural verified infec- tious/inflammatory/neoplastic diseases, but other than IA; group 2 in- cluded 24 (21.8%) patients without clinical and/or microbiological features of IA. ELISPOT has been performed, as described [Potenza et al. Leukemia 2007; 21: 578-81], by using as antigens Aspergillus either conidia or recombinant antigens, namely CRF1p, GEL1p, PEP1p, SOD1p, α1-3 glucan, β1-3 glucan and galactomannan (GM). Results. The patient and sample positivity rates were 94.4%/89.5% in proven, 45.7%/35.3% in probable, 35.3%/50% in possible IA cases and 1.8%/4.5% in the controls, respectively. The sensitivity and speci- ficity of ELISPOT for the diagnosis of IA resulted 94.4% (95% CI, 73%-99%) and 98.2% (95% CI, 93%-99%), respectively. The PPV of the test was 89.5% (95% CI, 67%-99%), the NPV was 99.1% (95% CI, 94%-100%) and the efficiency was 97.6% (95% CI, 92.3%- 99.4%). The positive likelihood ratio (LR) resulted 51.89, the negative LR was 0.06 (Table 1A,B). In proven IA patients, CSA demonstrated that Aspergillus-specific IL-10-T2 were predominantly central memory (CM) CD4+ T cells (median frequency 0.37%/0.22%), while Aspergillus-specific IFN-gamma-T1 were either CD4+ or CD8+ cells of either effector memory (EM) or CM phenotype (median frequen- cies 0.24%/0.20%). Also lower frequencies of Aspergillus-specific ei- ther CD4+ or CD8+ T cells producing IL-4 (0.11%/0.19%) of EM phenotype, and EM CD8+ cells producing IL-17 (0.18%), were de- tected. Moreover, although CRF1p, GEL1p, α1-3 glucan and SOD1p resulted the antigens eliciting the highest number of Aspergillus-spe- cific IFN-gamma-T1, only GEL1p and α1-3 glucan were those most constantly targeted by protective immune responses along the entire course of the IA. Conclusions. Our findings demonstrate the potential of ELISPOT in the diagnosis of IA, suggesting that it may comple- ment the other NCBDM, enabling a more consistent diagnosis of IA. Furthermore, this study describes for the first time the Aspergillus- specific immune responses in patients with proven IA, identifying also the antigens predominantly targeted by protective IFN-gamma- T1, with possible consequences in designing strategies of either adoptive cell infusion or vaccine therapies

Characterization of specific immune responses to different Aspergillus antigens during the course of invasive Aspergillosis in hematologic patients.

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Diagnosis of aspergillosis: Role of proteomics

The expansion of the antifungal armamentarium and the implementation of imaging techniques and new nonculture-based fungal diagnostics (NCBFDs) have improved the survival of patients with invasive aspergillosis (IA). However, mortality rates still remain high, possibly influenced by several pitfalls, affecting NCBFDs and reducing the window of opportunity for earlier treatment. A large body of in vitro and in vivo studies has demonstrated that several fungal proteic components are strongly immunogenic, and both the adaptive immunity and the innate branch are heavily involved in the recognition and clearance of fungal pathogens, resulting, on occasion, in a useful tool for the treatment of IA. By evaluating these studies, this review considers the possibility of exploiting either components of the innate or adaptive immunity to support the rapid and early diagnosis of IA. Copyright © 2009 by Current Medicine Group LLC