Kidney transplantation decreases the level and procoagulant activity of circulating microparticles

Microparticles (MP) are important players in cardiovascular disorders. Renal transplantation significantly improves the survival of hemodialyzed patients, in part because cardiovascular disease (CVD) progression is lessened. We hypothesized that the beneficial effect of renal transplantation on cardiovascular outcome might involve decreased levels of circulating MP. We evaluated the kinetics of MP subpopulations and their procoagulant activity (MP-PCA) in 52 patients before and 3, 6, 9 and 12 months after graft with reference to 50 healthy controls and we evaluated the impact of cardiovascular complications. During the follow-up, the increased levels of MP observed before graft were significantly decreased and reached normal values with different kinetics according to their cellular origin whereas MP-PCA remained significantly higher than in controls. From multivariate analysis, the levels of MP were negatively correlated with renal function. At 12 months, the decrease in MP and MP-PCA was more pronounced in patients without history of CVD than those with. In conclusion, we demonstrated that renal graft is associated with decreased levels of MP levels and MP-PCA, even more pronounced so in patients without history of CVD. Therefore, we suggest that MP lowering could be involved in the vascular dysfunction improvements reported after transplantation.

Impact of immunosuppressive treatment on endothelial biomarkers after kidney transplantation

Endothelial dysfunction occurs in hemodialysis and kidney-transplanted patients and can be enhanced by immunosuppressive therapy. Circulating endothelial cells (CEC), endothelial microparticles (EMP) and sVCAM-1 provide information on endothelium activation and damage. We compared the impact of two immunosuppressive regimens (CsA/Aza vs. Tac/MMF) on the kinetics of CEC, EMP and sVCAM-1 levels in 52 patients, both before graft and 3, 6, 9 and 12 months after graft, in reference to 50 healthy controls. CEC, EMP and sVCAM-1 levels were significantly decreased 1 year after transplantation (M12) as compared to pretransplant values. At M12, CEC and sVCAM-1 levels were significantly higher than those of controls whereas EMP reached normal values. Nine months postgraft, lower CEC and normalized EMP levels were found in patients receiving cyclosporine microemulsion/ azathioprine (CsA/Aza) when compared to patients treated with tacrolimus/ mycophenolate mofetil (Tac/MMF). Multivariate analysis evidenced positive correlations between CEC and history of cardiovascular diseases and between EMP and cytomegalovirus infection at M12. In conclusion, our combined analysis of endothelial injury markers confirms the favorable impact of renal transplantation on endothelium, and show that CEC levels discriminate treatment-associated endothelial toxicity. These results enlighten the potential of these noninvasive blood biomarkers in indexing vascular injury and optimize therapeutic options.

Clinicoepidemiological profile and predictors of severe illness in young infants (< 60 days) reporting to a hospital in North India

OBJECTIVES

To describe the clinical and epidemiological profile of young infants reporting to a hospital and assess previously proposed simple clinical signs for their value in enabling health workers to detect young infants with severe illness warranting hospital admission.

METHODS

Observational study of infants less than 2 months of age presenting consecutively to a large public hospital in South Delhi who were evaluated by a health worker (nurse), on a standardized list of signs and symptoms, and the ability of these were evaluated against the need for hospital admission which was assessed by an independent pediatrician.

RESULTS

Of the 1624 young infants triaged, 878 were enrolled into the study. Of these 100 (11%) were below 7 days of age, for whom the common reasons for seeking care were jaundice (52%), not feeding well (6%) and fever (5%). The remaining 778 (89%) were 7-59 days of age with respiratory symptoms as the main presenting complaints (29.1%). The primary clinical diagnoses in infants with serious illness needing admission to hospital in the age group <7 days (n = 66) were hyperbilirubinemia (56%) and sepsis (21%). In those between 7-27 days of age (n = 60), primary diagnoses were sepsis (27%), pneumonia (13%), diarrhea, dysentery or dehydration (10%), while in the age group 28-59 days of age (n = 47) pneumonia (40%), sepsis (19%) and diarrhea or dehydration (13%) were the common primary diagnoses. Signs that had at least a prevalence of 5% and were strong predictors for all the age categories studied were history of difficult feeding (OR 6.8 for 0-6 days, 15.1 for 2-27 days and 6.2 for 28-59 days age groups), not feeding well on observation (OR 13.7, 27.6 and 20.9 respectively for the 3 age groups), temperature > 37.5C (OR 21.8, 14.6 and 30.0 respectively for the 3 age groups) and respiratory rate > 60 per minute (OR 6.8, 15.1 and 21.0 respectively for the 3 age groups). Additional strong predictors with > 5% prevalence were history of convulsions (OR 7.9, only in 0-6 day age group), lethargy (OR 26.1, only in 7-27 day age group), and history of diarrhea (OR 3.0 for 2-27 days and 2.2 for 28-59 days age groups).

CONCLUSIONS

Simple clinical signs are useful in hands of health worker for identifying neonates with serious illness warranting hospital admission. These will be of use in the further development of clinical algorithms for the national integrated management of childhood illnesses.

Species and cultural conservation in New Zealand: maori traditional ecological knowledge of tuatara

Traditional ecological knowledge can be highly informative and integrated with complementary scientific knowledge to improve species management. This is especially true for abundant species with which indigenous peoples have frequent interactions (e.g., through harvest), but has been studied less frequently in isolated or declining species. We examined Maori traditional ecological knowledge of tuatara (Sphenodon spp., reptiles that resemble lizards but are the last living representatives of the order Sphenodontia) through semidirected interviews of elders of Te Atiawa, Ngati Koata, and Ngati Wai Iwi (similar to tribes), the guardians of several islands currently inhabited by tuatara. Maori are indigenous to New Zealand, having settled 800 to 1000 years ago. Tuatara are endemic to New Zealand, have declined in numbers since human settlement, and are now restricted to 37 offshore islands. The detail and volume of tuatara traditional ecological knowledge were less than that recorded in studies of more abundant or accessible species. In addition, traditional knowledge of the cultural significance of tuatara was more common and detailed among the elders than traditional knowledge of tuatara biology or ecology. The traditional knowledge collected, however, provided the first evidence of seven former sites of tuatara occupation, suggested five additional sites tuatara may currently occupy, contained novel hypotheses for scientific testing, and described tuatara cultural roles that have not been reported previously. We conclude that, in at least some cases, traditional ecological knowledge may persist as species decline and may serve as a valuable source of ecological information for conservation.

Les cellules natural killer : acquisitions récentes et implication en pathologie humaine

INTRODUCTION

Natural killer cells are cytotoxic lymphocytes of innate immunity. These last ten years our knowledge about the mechanisms that regulates NK cell function has greatly improved. Our purpose is to present a review of these new acquisitions and their potential implications in human disease.

CURRENT KNOWLEDGE AND KEY POINTS

NK cell function is regulated by a repertoire of NK cell receptors and is diversified by recognition of MHC class I by a multigenic and multi-allelic family of NK receptors. Analysis of NK cell repertoire has been used to investigate features that characterize NK cells in pathological situations. Apart from their direct cytotoxic potential to eliminate target cells, recently identification of mechanisms that control NK cell mediated cytokine production and cross talk with dendritic cells emphasize the role of NK cells in the regulation of acquired immune response.

FUTURE PROSPECTS AND PROJECTS

These findings have lead to a better knowledge of the importance of the NK cells in several human diseases. It has been shown that NK cells are actors of the immunosurveillance of tumoral and infectious challenges. Allo or auto reactivity of the NK cell compartment have also been suggested in autoimmune diseases, infertility or foetal loss and transplantation. Ongoing research on NK cells in the fields of human diseases is increasing and will clarify the utility of the evaluation of the NK cell compartment and their receptors in clinical practice.

Characterization of a new HLA-C allele: Cw*0719

We describe a new human leukocyte antigen (HLA)-Cw*07 allele that differs from Cw*0718 by a single-coding nucleotide. DNA-based genotyping identified a clinical sample from a Black African-American patient that differed from known Cw alleles. The allele was amplified independently with a haplo-specific primer and sequenced in its entirety.

Monocyte enrichment from leukapharesis products for the generation of DCs by plastic adherence, or by positive or negative selection

BACKGROUND

DCs for use in immunotherapy are frequently generated from peripheral blood monocytes. However, there are different approaches to monocyte enrichment.

METHOD

Plastic adherence is a widely used method for the enrichment of monocytes collected in a leukapheresis procedure. Alternatively,monocytes may be enriched by positive selection using magnetic beads coupled to CD14 Abs, or by cell depletion using beads coupled to Abs against CD2 and CD19 to remove non-monocytes.

RESULTS

Positive selection resulted in the highest purity of immature DCs (97 +/- 1%), but in a low yield (8 +/- 3%). In contrast, depletion of non-monocytes gave a good yield (21 +/- 6%), but insufficient purity (42 +/- 10%). Conventional adherence procedures resulted in a good yield (25 +/- 5%) and reasonable purity (72 +/- 4%). All three monocyte enrichment procedures resulted in DCs that underwent maturation upon exposure to a combination of lipopolysaccharide and IFN-gamma. These DCs had a typical immune phenotype, they released similar amounts of IL-12, and had the capacity to support MLR.

CONCLUSION

Our data provide a basis to choose a monocyte enrichment procedure that favors high purity or a high yield. However, if a manual open system suffices, plastic adherence is a reasonable alternative.

The effect of iron therapy on the growth of iron-replete and iron-deplete children

This prospective, double-blind, placebo-controlled trial was designed to study the effect of iron therapy on the growth of iron-replete and iron-deficient children, and to study the change in iron status in iron-deficient children with iron therapy. One hundred and fifty children (aged 6-24 months) were included in the study. After an informed written consent, 100 healthy children, who were iron replete (group I) according to preset criteria, were randomly allocated to receive iron supplements 2 ng/kg/day (group IA) or placebo (group IB). Fifty iron-deficient children (group II) were administered iron syrup 6 mg/kg/day. Growth parameters (weight, length and head-circumference) and hematological parameters were studied for 4 months. Iron therapy, as compared with placebo, produced a significant improvement of mean monthly weight gain (p < 0.001) and linear growth (p < 0.001) in the iron-deficient children. However, it significantly decreased the weight gain (p < 0.001) and linear growth (p < 0.001) of iron-replete children. Caution should therefore be exercised while supplementing iron to children with apparently normal growth and when the iron status of the child is not known.

[General practitioners' practices and attitudes in regard to suicidal behavior]

As demonstrated at the recent Consensus Conference on the "suicidal crisis" held by the French Psychiatry Union and the National Agency for the Accreditation and the Evaluation of Care, suicide is recognised as a current public health problem. The general practitioner's role is situated on two levels: in a preliminary stage, the early identification of risk, and in a secondary stage, the provision of care at the time of a suicide attempt and then the provision of on-going follow-up care in partnership with other special services. The study aimed at evaluating general practitioners' practices when encountered with suicidal patients and assessing their management of suicidal behaviour, as well as difficulties met and their expectations. Responses to a questionnaire were received from 290 general practitioners in one regional department in France. The results revealed that two-thirds of the respondents considered the identification of suicidal tendencies as being difficult, in particular with regard to the detection of young people at risk. General hospitals are the most common structures where patients are referred to in the event of a suicide attempt, as a facility that is permanently open and capable of delivering ambulatory care. A majority of the general practitioners expressed the need for training which was focused on methods for the early identification of risk as well as the development of listening skills.

Altered HLA-G transcription in pre-eclampsia is associated with allele specific inheritance: possible role of the HLA-G gene in susceptibility to the disease

Pre-eclampsia is a disorder of human pregnancy occurring in 5-10% of all births, and represents the leading cause of infant morbidity and mortality and maternal death. In pre-eclampsia, invasion of fetal trophoblasts into maternal arteries during early pregnancy is shallow or absent. Here we examined the hypothesis that HLA-G, a non-classical class I HLA expressed in cytotrophoblasts, may act as a key gene in pre-eclampsia. We analysed HLA-G at the level of transcription and genotyped a silent CAC-CAT polymorphism in exon 3 and a 14-bp insertion/deletion in the 3' untranslated region. A deficit in levels of the HLA-G3 transcript was observed in mild pre-eclampsia compared to normal placentas. The distribution of HLA-G polymorphisms was different between normal and pre-eclampsia samples. A correlation between the alteration in transcription of the HLA-G gene and certain HLA-G genotypes was also observed. Thus we provide the first evidence for a possible role of HLA-G in genetic susceptibility to, and pathogenesis of pre-eclampsia.

Knowledge of epidemiology and statistics for an ophthalmic practitioner

Ophthalmologists are frequently confronted with treatment options that claim to be better than those currently in use. Statistically significant P values are invariably provided by way of proof. For many ophthalmologists a simple look at this revered P value is enough evidence that a statistically significant result has indeed been obtained. Unfortunately, traditional interpretation of a study based on the P value at an arbitrary cut-off (P<0.05 or any other value) limits the ability to fully appreciate clinical implications. In this article the authors introduce the reader to and illustrate the use of "confidence intervals" as opposed to P values in examining the applicability of study results. Further, what is statistically significant may not necessarily be clinically significant; perhaps not enough for the practitioner to change from the currently preferred method of treatment. To resolve this, the authors have also used common ophthalmic examples to introduce the "number needed to treat", as a simple clinical approach for the practising ophthalmologist wishing to assess the clinical significance of treatment options.

Tumor-specific up-regulation of the nonclassical class I HLA-G antigen expression in renal carcinoma

HLA-G is a nonclassical class I antigen mainly expressed at the maternofetal interface during pregnancy where it is thought to down-modulate maternal immune response against the semiallogeneic fetus. Recent studies indicate that ectopic up-regulation of HLA-G expression on melanoma cells may also favor their escape from antitumor immune response. HLA-G expression was here investigated on paraffin-embedded tumor and adjacent normal renal tissues of 18 renal cell carcinoma (RCC) patients. We provide evidence that HLA-G antigen is differentially expressed in carcinoma and normal renal cells and that up-regulation of this antigen in the tumor cells is more frequent than alterations of other MHC class I or class II antigens. We also demonstrated that HLA-G cell surface expression and secretion is maintained in a tumor cell line (DM) established from an HLA-G-positive RCC lesion. Furthermore, we show that type I (alpha and beta) and, in particular, type II (gamma) IFN treatment enhances steady-state mRNA levels and cell surface expression of HLA-G in the DM cell line. As several studies suggest that HLA-G displays various functional features that allow down-modulation of immune response in vitro, we propose that selective in vivo expression of HLA-G may participate in the impairment of antitumor immunity in RCC.

Activation of p53 transcriptional activity requires ATM's kinase domain and multiple N-terminal serine residues of p53

The ATM protein kinase regulates the cell's response to DNA damage by regulating cell cycle checkpoints and DNA repair. ATM phosphorylates several proteins involved in the DNA-damage response, including p53. We have examined the mechanism by which ATM regulates p53's transcriptional activity. Here, we demonstrate that reintroduction of ATM into AT cells restores the activation of p53 by the radio-mimetic agent bleomycin. Further, p53 activation is lost when a kinase inactive ATM is used, or if the N-terminal of ATM is deleted. In addition, AT cells stably expressing ATM showed decreased sensitivity to Ionizing Radiation-induced cell killing, whereas cells expressing kinase inactive ATM or N-terminally deleted ATM were indistinguishable from AT cells. Finally, single point-mutations of serines 15, 20, 33 or 37 did not individually block the ATM-dependent activation of p53 transcriptional activity by bleomycin. However, double mutations of either serines 15 and 20 or serines 33 and 37 blocked the ability of ATM to activate p53. Our results indicate that the N-terminal of ATM and ATM's kinase activity are required for activation of p53's transcriptional activity and restoration of normal sensitivity to DNA damage. In addition, activation of p53 by ATM requires multiple serine residues in p53's transactivation domain.

HLA-G2, -G3, and -G4 isoforms expressed as nonmature cell surface glycoproteins inhibit NK and antigen-specific CTL cytolysis

HLA-G is a nonclassical MHC class I molecule that plays a major role in maternal-fetal tolerance. Four membrane-bound (HLA-G1 to -G4) and two soluble (HLA-G5, and -G6) proteins are generated by alternative splicing. Only HLA-G1 has been extensively studied in terms of both expression and function. We provide evidence here that HLA-G2, -G3, and -G4 truncated isoforms reach the cell surface of transfected cells, as endoglycosidase H-sensitive glycoproteins, after a 2-h chase period. Moreover, cytotoxicity experiments show that these transfected cells are protected from the lytic activity of both innate (NK cells) and acquired (CTL) effectors. These findings highlight the immunomodulatory role that HLA-G2, -G3, and -G4 proteins will assume during physiologic or pathologic processes in which HLA-G1 expression is altered.

Resolution of cis-trans ambiguities between HLA-DRB1 alleles using single-strand conformation polymorphisms and sequencing

DNA-based typing of HLA alleles occasionally results in the inability to assign a specific allele because of ambiguity in associating two or more polymorphisms to the same or to alternate homologs (cis/trans ambiguity). Since most individuals are heterozygous at a given HLA locus, the highest level of confidence in definition is obtained when the alleles are tested in isolation. By using single-strand conformation polymorphisms (SSCP) to separate heterozygous HLA-DRB1 alleles, followed by sequencing of separated conformers, we have achieved resolution of previously ambiguous assignments without the need for additional probes or primers.

A specific interferon (IFN)-stimulated response element of the distal HLA-G promoter binds IFN-regulatory factor 1 and mediates enhancement of this nonclassical class I gene by IFN-beta

Type I interferons display a broad range of immunomodulatory functions. Interferon beta increases gene expression at the transcriptional level through binding of factors to the interferon-stimulated response element (ISRE) within the promoters of interferon-inducible genes, such as HLA class I. Despite mutation of the class I ISRE sequence within the nonclassical HLA-G class I gene promoter, we show that interferon beta enhances both transcription and cell surface expression of HLA-G in trophoblasts and amniotic and thymic epithelial cells that selectively express it in vivo. Deletion and mutagenesis analysis of a putative interferon-regulatory factor (IRF)-1 binding site within the HLA-G promoter show that HLA-G transactivation is mediated through an ISRE sequence 746 base pairs upstream from ATG, which is distinct from the interferon-responsive element described within proximal classical class I gene promoters. Electrophoretic mobility shift analysis and supershift analysis further demonstrate that interferon-responsive transcription factors, including IRF-1, specifically bind to the HLA-G ISRE. Our results provide evidence that IRF-1 binding to a functional ISRE within the HLA-G promoter mediates interferon beta-induced expression of the HLA-G gene. These observations are of general interest considering the implication of HLA-G in mechanisms of immune escape involved in fetal-maternal tolerance and other immune privilege situations.

A comparison of concurrent and retrospective verbal protocol analysis

In verbal protocol analysis, verbalization can occur either during decision making (concurrent data) or after (retrospective data). Although both methods have advantages and disadvantages, no empirical research has focused on a direct comparison. This study compared the effectiveness of concurrent and retrospective data for revealing the human decision making process. In general, the concurrent protocol analysis method outperformed the retrospective method. Not only was the number of concurrent protocol segments elicited higher than that of retrospective protocol segments, but concurrent data provided more insights into the decision-making steps occurring between stimulus introduction and the final choice outcome. However, retrospective protocols offer an interesting advantage: More statements about the final choice are provided in retrospective protocols than in concurrent protocols.