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Biomedical subjects

C Mary

Publications and source records attributed to C Mary.

At least 19 recordsLinked to original sources
PubMed2007

Elevated levels of soluble non-classical major histocompatibility class I molecule human leucocyte antigen (HLA)-G in the blood of HIV-infected patients with or without visceral leishmaniasis.

The non-classical class I major histocompatibility complex molecules human leucocyte antigen (HLA)-G have been shown to play a role in HIV persistence, but no data are available on the expression of the soluble forms HLA-G5 and sHLA-G1 in HIV-infected patients with and without opportunistic infections. The soluble HLA-G isoform was measured with an enzyme-linked immunosorbent assay (ELISA) method in plasma from 94 subjects: 31 HIV-1-seropositive, 17 with visceral leishmaniasis (VL), seven with both VL and HIV-1 infection and 39 healthy HIV-seronegative subjects. Between groups, the frequency of sHLA-G positivity was statistically different: 81% of HIV-infected patients were positive, as were 57% of HIV-Leishmania infantum co-infected patients, 35% of HIV-seronegative patients with VL and 3% of healthy controls. Levels of the soluble forms of the immunomodulatory molecules HLA-G are elevated during HIV infection. In HIV-Leishmania co-infected patients, sHLA-G secretion could contribute to the tolerogenic environment and to Leishmania immune evasion.

AIDS-Related Opportunistic Infections↗
PubMed2004

[A group fever: safari's fever].

INTRODUCTION: Acute schistosomiasis, called safari's fever in Africa and Katayama fever in Japan, is an immunoallergic reaction due to transcutaneous penetration of infective cercaria. We report the collective case of seven young adults spending holidays in Mali. EXEGESIS: An eighteen years-old girl presents fever, headache, diarrhoea and abdominal pains at return from Dogon country (south of Mali). After turned down malaria and with the notion of bathing in fresh water followed by pruritus, we think to safari's fever. So we alarm all other members of the group. All can be treated to avoid chronic schistosomiasis. CONCLUSION: These observations recall that acute schistosomiasis is a real danger for tourists when bathing in fresh water in endemic areas of Africa. Education of travellers is necessary. Occurrence of safari's fever should alert physicians to prevent chronic schistosomiasis.

Adolescent↗
PubMed2003

Contrasting cellular responses in Schistosoma haematobium infected and exposed individuals from areas of high and low transmission in Zimbabwe.

The study compared cytokine profiles of individuals from two areas with different transmission patterns for Schistosoma haematobium. One area was a high transmission (HT) while the other was a low transmission (LT) area for S. haematobium. Observations on cellular immune responses were made on stimulated peripheral blood mononuclear cells (PBMC), which were collected pre-treatment, then at 12 and 18 months post treatment. Stimulation was with schistosome worm and egg antigens and a mitogen, phaetohaemaglutinin (PHA). Observations were made on PBMC proliferation and the profiles of cytokine produced over a 5-day incubation period. The two distinct areas showed significant differences on both levels of proliferation and cytokine production for all the measured classes (IL-4, IL-5, IL-10 and IFN-gamma). PBMC from individuals from the LT area had high levels of proliferation but low cytokine production to both antigen stimulants while PBMC from individuals from the HT area showed low levels of proliferation but high cytokine production levels. Prior to treatment, individuals not excreting schistosome ova in the HT area had higher levels of proliferation to the stimulants, than the infected individuals. However, after treatment re-infected individuals showed high levels of proliferation. Before treatment, both infected and uninfected groups showed low and similar ratios, respectively, of IL-4:IFN-gamma, IL-5:IFN-gamma and IL-10:IFN-gamma, while IFN-gamma was high in the infected individuals. After treatment the non re-infected had higher levels of IL-4, IL-5 and IL-10, with the infected having high levels of IFN-gamma. Th1-like response dominated during infection with the Th2-like responses dominating post treatment and in uninfected individuals. The results indicated that the cytokine balance determines, in part, susceptibility or resistance to S. haematobium infection.

Adolescent↗
PubMed2001

T cell clones from Schistosoma haematobium infected and exposed individuals lacking distinct cytokine profiles for Th1/Th2 polarisation.

T cell clones were derived from peripheral blood mononuclear cells of Schistosoma haematobium infected and uninfected individuals living in an endemic area. The clones were stimulated with S. haematobium worm and egg antigens and purified protein derivative. Attempts were made to classify the T cell clones according to production of the cytokines IL-4, IL-5 and IFN-gamma. All the T cell clones derived were observed to produce cytokines used as markers for the classification of Th1/Th2 subsets. However, the 'signature' cytokines marking each subset were produced at different levels. The classification depended on the dominating cytokine type, which was having either Th0/1 or Th0/2 subsets. The results indicated that no distinct cytokine profiles for polarisation of Th1/Th2 subsets were detected in these S. haematobium infected humans. The balance in the profiles of cytokines marking each subset were related to infection and re-infection status after treatment with praziquantel. In the present study, as judged by the changes in infection status with time, the T cell responses appeared to be less stable and more dynamic, suggesting that small quantitative changes in the balance of the cytokines response could result in either susceptibility or resistant to S. haematobium infection.

Animals↗
PubMed2000

Dysregulated expression of the Cd22 gene as a result of a short interspersed nucleotide element insertion in Cd22a lupus-prone mice.

The Cd22 gene encodes a B cell-specific adhesion molecule that modulates B cell Ag receptor-mediated signal transduction, and is allelic to a lupus-susceptibility locus in New Zealand White (NZW) mice. In this study, we show that, in addition to the wild-type transcripts, NZW (Cd22a) mice synthesize aberrant CD22 mRNAs that contain approximately 20-120 nucleotide insertions upstream of the coding region between exons 2 and 3, and/or approximately 100-190 nucleotide deletions of exon 4. Sequence analysis revealed that these aberrant mRNA species arose by alternative splicing due to the presence in the NZW strain of a 794-bp sequence insertion in the second intron, containing a cluster of short interspersed nucleotide elements. Both the presence of sequence insertion and aberrantly spliced mRNAs were specific to mice bearing the Cd22a and Cd22c alleles. Up-regulation of CD22 expression after LPS activation appeared impaired in Cd22a spleen cells (twice lower than in Cd22b B cells). Furthermore, we show that partial CD22 deficiency, i.e., heterozygous level of CD22 expression, markedly promotes the production of IgG anti-DNA autoantibodies in C57BL/6 (Cd22b) mice bearing the Y chromosome-linked autoimmune acceleration gene, Yaa. Taken together, these results suggest that a lower up-regulation of CD22 on activated B cells (resulting from Cd22 gene anomaly in Cd22a mice or from CD22 heterozygosity in mutants obtained by gene targeting) is implicated in autoantibody production, providing support for Cd22a as a possible candidate allele contributing to lupus susceptibility.

5' Untranslated Regions↗
PubMed1999

Control of Leishmania infantum infection is associated with CD8(+) and gamma interferon- and interleukin-5-producing CD4(+) antigen-specific T cells.

Visceral leishmaniasis is a severe and lethal disease caused by the protozoan parasites of the genus Leishmania. In areas where leishmaniasis is endemic, most infected individuals control the infection and remain asymptomatic; chemotherapy of visceral leishmaniasis restores some immunity which protects against relapses. In the present study, Leishmania-specific T-cell clones were established from six asymptomatic and five cured patients. Cytokines production by these clones was analyzed. A large fraction of the parasite-specific T-cell clones from asymptomatic patients were CD8(+) and produced high amounts of gamma interferon (IFN-gamma). Most CD4(+) T-cell clones from two asymptomatic subjects exhibited an unusual phenotype: production of high levels of IFN-gamma low levels of interleukin-4, (IL-4), but high levels of IL-5. In contrast, only few parasite-specific CD8(+) T-cell clones were obtained from cured patients after chemotherapy; moreover, CD4(+) T-cell clones from these patients exhibited an heterogeneous profile of cytokines from Th1-like to Th2-like phenotypes. These results point to CD8(+) T cells and to IL-5- and IFN-gamma-producing CD4(+) T cells as possible contributors to human resistance to Leishmania infection. They should stimulate new immunological approaches in the control of this disease.

Adolescent↗
PubMed1998

Linkage of a major quantitative trait locus to Yaa gene-induced lupus-like nephritis in (NZW x C57BL/6)F1 mice.

In the present study, we mapped the major quantitative trait loci (QTL) differing between the NZW and C57BL/6 inbred strains of mice by making use of (NZW x C57BL/6.Yaa)F1 mice, a model in which the lupus-like autoimmune syndrome observed in male mice is associated with the presence of an as yet unidentified Y chromosome-linked autoimmune acceleration gene, Yaa. Linkage analysis of 126 C57BL/6 x (NZW x C57BL/6.Yaa)F1 backcross males provided evidence for a major QTL on chromosome 7 controlling both the severity of glomerulonephritis and the production of IgG anti-DNA autoantibody and retroviral gp70-anti-gp70 immune complexes. Two additional QTL of C57BL/6 origin on chromosome 17 had no apparent individual effects, but showed strong epistatic interaction with chromosome 7 QTL for disease severity and anti-DNA autoantibody production. Our data also identified on chromosome 13 a QTL of NZW origin with a major effect on the level of gp70, and showing an additive effect with the chromosome 7 QTL on the level of gp70 immune complexes. Our study thus provides a model to dissect the complex genetic interactions that result in manifestations of murine lupus-like disease.

Animals↗
PubMed1997

In vitro and in vivo studies of a polyester arterial prosthesis with a warp-knitted sharkskin structure.

The present study was undertaken to assess the performance of a new knitted and gelatin-sealed polyester vascular graft that is believed to have greater dimensional stability than current commercial devices. Samples of the uncrimped, crimped, and sealed prosthesis were submitted to a series of in vitro and in vivo trials. Four commercial polyester knitted devices were included as controls for the in vitro tests, which included measurements of the textile and yarn structure and physical, chemical, and thermal properties of the graft, such as water permeability, dilatation, suture retention strength, melting point, and crystallinity index. The in vivo evaluation involved implanting the prototype device as a canine thoraco-abdominal bypass for periods ranging from 4 h to 1 year and assessing the biocompatibility, biofunctionality, and biostability of the explanted specimens. The warp-knitted structure of the prototype device has a unique sharkskin stitch that confers a superior dilatation resistance and suture retention strength to the prosthesis. The animal trial demonstrated that the gelatin ensures initial hemostasis without preclotting. The gelatin is bioresorbed during the first 2 weeks of implantation, which generates a temporary, moderate, acute inflammatory response. An external capsule of granulomatous tissue and an internal collagen capsule are formed between the first and third month. Analysis of the textile and physical properties of the explanted prostheses confirmed there was neither dilatation nor significant changes in structure or mechanical performance during implantation, thus confirming the biostability of this new prototype device and opening the way for clinical trials.

Anastomosis, Surgical↗
PubMed1996

Canine leishmaniasis: identification of asymptomatic carriers by polymerase chain reaction and immunoblotting.

A major limitation to the study of the epidemiology of canine visceral leishmaniasis is the inability to identify and count asymptomatic carriers because classic diagnositc tests are insufficiently sensitive. We investigated the capacity of the polymerase chain reaction (PCR) to detect the parasite and immunoblotting to detect specific antibodies in samples from dogs living in an endemic area without any symptoms of leishmaniasis. Results of classic serologic tests (immunofluorescence and enzyme-linked immunosorbent assay) were negative. Two independent PCR assays detected the parasite in skin and conjunctival samples from 80% of the dogs. We found specific antibodies by immunoblot in 66% and 56% of the dogs had both specific antibodies and parasite DNA. As controls, samples from dogs with clinical manifestations of the disease before and after treatment were assayed. The frequency of positive PCR samples decreased after treatment, and although antibody levels decreased with cure of the disease, they remained detectable by immunoblot. Results showed that most of the dogs living in an endemic area had been exposed to Leishmania. Both PCR and immunoblot are sensitive enough to detect asyptomatic infection and could be valuable tools for studies monitoring the transmission of the disease and vaccination trials.

Animals↗
PubMed1995

Continuous RT-PCR using AMV-RT and Taq DNA polymerase: characterization and comparison to uncoupled procedures.

A continuous reverse transcription polymerase chain reaction (RT-PCR) procedure was designed with all reaction components included in a single tube prior to thermal cycling. This procedure was compared to uncoupled RT-PCR procedures wherein the addition of reagents was separated. In the latter, in particular, conditions for reverse-primer annealing and cDNA synthesis were investigated. The two RT-PCR approaches were compared in the detection of singly spliced and multiply spliced human immunodeficiency virus type 1 (HIV-1) mRNs. The avian myeloblastosis virus reverse transcriptase and Taq DNA Polymerase were used in the continuous procedure under the compromised condition wherein the two enzymes were active in the same buffer. Reverse transcription was carried out at an elevated temperature of 50 degrees C to overcome problems of mRNA secondary structures that could inhibit the reaction. The continuous procedure was found to be as specific and efficient as the best uncoupled procedure. The procedure was shown to be reliable and to have the sensitivity to detect one HTLV-IIIB-infected H9 cell in a million uninfected H9 cells.

Avian Myeloblastosis Virus↗
PubMed1994

Quantitative and discriminative detection of individual HIV-1 mRNA subspecies by an RNAse mapping assay.

HIV-1 genes are expressed through the complex splicing of a single mRNA precursor leading to three mRNA classes: unspliced, singly-spliced and multiply-spliced. Each class may include several mRNA species specifically encoding one or two HIV-1 proteins. Northern blotting and RT-PCR are the techniques currently used to analyse HIV-1 mRNA expression. Northern blotting allows quantitative detection of these three classes of viral RNA but does not discriminate between individual RNA species. RT-PCR allows discrimination between different species but does not provide a quantitative analysis. Here, we describe an application of an RNAse mapping assay which gives both quantitative and discriminative HIV-1 RNA detection. A radiolabeled probe overlapping the major splicing sites of HIV-1 used for the generation of HIV-1 mRNA subspecies was synthesized. This probe protects differential sizes of these species, allowing discrimination between them. We investigated the RNA expression pattern in high titer HIV-1 producing cells. The HIV-1-specific probe allowed the detection of multiply-spliced vpr, rev and nef mRNAs, singly-spliced env mRNA and unspliced genomic RNA. With its discriminative and quantitative properties, this application is particularly convenient for the investigation of HIV-1 mRNA expression during the course of HIV-1 infections.

Base Sequence↗
PubMed1994

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

Lung toxoplasmosis after HLA mismatched bone marrow transplantation.

We report a clinically isolated toxoplasma pneumonitis in a child treated by HLA haplo-mismatched BMT. Conditioning consisted of TBI, cytarabine and melphalan. The BM graft was T-depleted and the boy received iv moAb antiLFA1 and antiCD2. The clinical course of pneumonitis was characterised by an early onset (day 28) and a rapidly overwhelming course. Donor and recipient had pre-graft IgG Ab against toxoplasma without IgM. These Abs had completely disappeared from the serum of the patient at the time of pneumonitis. PCR amplification detected the B1 gene of Toxoplasma gondii in the patient's PBMC from day 28.

Animals↗