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M Joussemet

Publications and source records attributed to M Joussemet.

At least 19 recordsLinked to original sources
PubMed2006

[One case report of anti-JK1 antibody undetected on plasma sample].

The sensitivity of the detection of irregular antibodies (DIA) is one of the fundamental bases of transfusion safety. Its implementation is specified in accordance with a very specific framework that allows the use of serum or plasma. The case reported here points out a failure to detect irregular antibodies in plasma sample. Thus a low intensity anti-JK1 antibody detected and identified in serum slipped through unnoticed in plasma. The difficulties to detect and identify this antibody, well-known as a deceptive and dangerous one, are being discussed in order to better assess the limitations of DIA.

Aged, 80 and over↗
PubMed2006

CD127 expression and regulation are altered in the memory CD8 T cells of HIV-infected patients--reversal by highly active anti-retroviral therapy (HAART).

HIV infection activates abnormally the immune system and the chronic phase is accompanied by marked alterations in the CD8 compartment. The expression of CD127 (IL-7R alpha chain) by memory CD8 T lymphocytes in HIV-infected patients is analysed and reported. The memory CD8 T cell subset was characterized by expression of CD45RA and CD27 markers, and CD127 cell surface expression was measured ex vivo by four-colour flow cytometry. HIV infection was associated with a fall in the proportion of CD127(+) cells among memory CD8 lymphocytes that resulted in a higher CD127(-) CD45RA(-)CD27(+) CD8 T cell count in HIV-infected patients. Diminished CD127 cell surface expression [mean fluorescence intensity (MFI)] by positive cells was also observed in this subset. The data suggest that these defects were reversed by highly active anti-retroviral therapy (HAART). The regulation of CD127 expression was also studied in vitro. Down-regulation of CD127 by interleukin (IL)-7 was observed in memory CD8 lymphocytes from healthy donors and HAART patients. Expression of CD127 by memory CD8 lymphocytes cultured in the absence of IL-7 confirmed that IL-7R regulation is altered in viraemic patients. Under the same experimental conditions, memory CD8 lymphocytes from HAART patients were shown to express CD127 at levels comparable to cells from healthy individuals. Altered CD127 cell surface expression and defective CD127 regulation in the memory CD8 T lymphocytes of HIV-infected patients are potential mechanisms by which these cells may be impeded in their physiological response to endogenous IL-7 stimulatory signals. Our data suggest that these defects are reversed during the immune reconstitution that follows HAART.

Antiretroviral Therapy, Highly Active↗
PubMed2004

[French training program for medical students in transfusion medicine. Transfusion Medicine Teachers' College].

In France, transfusion medicine training program has been updated. A national committee of professors in transfusion medicine propose a series of 13 items which represent the minimum knowledge that general practitioners should possess. This overview of transfusion medicine is far below the level that specialists should reach and they will need an additional specialized training. Several French universities have set up their own training program which is quite similar to the work of the committee of professors. The following recommendations are not strict guidelines but is a common basis which will be improved in 2005 according to new evidence based transfusion medicine.

Accidents, Occupational↗
PubMed2003

Quality assessment of seven types of fresh-frozen plasma leucoreduced by specific plasma filtration.

BACKGROUND AND OBJECTIVES: A study was undertaken to determine plasma quality after specific filtration. MATERIALS AND METHODS: Seven types of plasma were tested, after filtration of plasma from filtered or non-filtered whole blood. Leucocyte counting was carried out after a 30-fold concentration of the sample. Twenty-nine parameters (including coagulation testing, proteins, coagulation factors and activation markers) were measured before and after filtration, and after 6 months of storage. RESULTS: After specific plasma filtration, the average residual leucocyte counts were less than 2250/l. In spite of small statistically significant changes in proteins, coagulation factors and complement activation, this study showed that plasma filtration did not alter plasma quality. After 6 months of storage at -30 degrees C, factor VIII recovery varied between 91 and 109%. Haemostasis parameters and activation markers remained within the normal range. CONCLUSIONS: Specific plasma filtration reduced the leucocyte number to < 104 leucocytes/l. The quality of plasma was not altered by the additional step of specific plasma filtration.

Biomarkers↗
PubMed2003

[Comparison of techniques used to screen blood donations for malaria antibodies].

In France all but one of the serological tests used to screen blood donations rely on ELISA-based techniques. The exception is malaria antibody detection that is performed by the indirect fluorescent antibody technique using commercially available kits. The reagent kit used at the French Army Blood Bank (FABB) is Falciparum-Spot IF (bioMerieux). However since the antigens in this kit are obtained from group A1 red blood cell cultures, false positive results can occur due to binding of natural antiglobulins. Over a 10-month period at the FABB, we disqualified a total of 55 donations (5.02% of total donations) because of positive Falciparum-Spot IF@1000 test results. Most disqualified donations (84%) involved donations with group O red blood cells. In the present retrospective study, these 55 disqualified donations were used to compare the specificity of three other serological tests used for detection of malaria antibodies: Falciparum-SpotIF after elimination of natural antiglobulins by absorption and neutralization with Witebski reagent and Paludix (Diagast). Use of all three techniques provided a specificity gain of over 87% but elimination using Witebski reagent led to a loss of sensitivity. At the FABB we have been using the Falciparum-Spot IF kit after elimination of natural antiglobulins since April 2001. Only 1.62% of donations tested have been disqualified due to the presence of malaria antibodies including 52% with group O red blood cells.

Antibodies, Protozoan↗
PubMed2002

[Transfusional record and blood grouping methods: essential factors of transfusion safety].

The clinical and biological control of the whole transfusion process is a major preoccupation for everyone dealing with blood transfusion. Specially when the patient is a female recipient or belongs to a group with a high prevalence of alloimmunisation. This case report points out the outstanding importance of the immune compatibility, which must be strongly maintained to prevent any harmful consequences. The transfusional record transmission and a simple and sensitive blood grouping test are essential to increase transfusion safety.

Blood Group Antigens↗
PubMed1999

[Fall in the seroprevalence of hepatitis A in French youth].

OBJECTIVE: An anti-hepatitis A virus seroprevalence survey was performed in 1997 in 1052 French army recruits (mean age: 21.2 years). To describe epidemiological trends, the current pattern was compared to previous results obtained by similar methods in 1985, 1990 and 1993. RESULTS: In 1997, overall anti-hepatitis A virus seroprevalence was 11.5%. The greatest risk factor of hepatitis A infection was related to travel in intermediate or highly endemic areas for hepatitis A virus: 46% of overseas residents (odds ratio = 10.3), 28% of recruits who had travelled in developing countries (odds ratio = 3.7) and 7.65% of French living in industrialised countries are anti-hepatitis A virus antibody positive. Moreover, seroprevalence was higher in subjects with a history of icteria (adjusted odds ratio = 3.5) and families with at least 3 children (adjusted odds ratio = 3). No association was found with drinking water, socioeconomic status such as baccalaureat degree, or parents profession. The seroepidemiological shift of hepatitis A, as assessed in three previous studies, shows a marked decrease of 20% in 12 years from 30.4% in 1985, to 21.3% in 1990, to 16.3% in 1993, and to 11.5% in 1997. The decrease in the prevalence of anti-hepatitis A virus was more marked in young adults who had never travelled in endemic countries (decrease of 20%) than those who had visited or lived in developing countries (decrease of 10%). CONCLUSION: Although France is not highly endemic for hepatitis A thanks to improved hygiene and housing conditions over the past 20 years, a pattern of intermediate endemicity was seen in French overseas areas in which the risk of outbreaks of hepatitis A was higher. The decrease in anti-hepatitis A virus seroprevalence in French youth can be used to draft a public health policy for hepatitis A control.

Adolescent↗
PubMed1998

Regulatory dysfunction of the interleukin-2 receptor during HIV infection and the impact of triple combination therapy.

The interleukin-2 (IL-2)/IL-2 receptor (IL-2R) system is the main regulatory determinant of T cell reactivity. Although it is well known that IL-2 secretion is impaired during HIV infection, up to now IL-2R expression has not been extensively studied in HIV-infected patients despite the use of IL-2 in clinical therapy trials. We show here that IL-2R expression in HIV patients with high viral load (group 1 in the study) is greatly enhanced on B lymphocytes, CD8 T lymphocytes, and monocytes, but not on CD4 T lymphocytes, compared with noninfected individuals. Paradoxically, this modified IL-2R expression does not lead to increased IL-2 responsiveness, except for B lymphocytes. In patients receiving triple combination therapy (TCT, two reverse transcriptase inhibitors and one protease inhibitor) that has triggered a drastic reduction in plasma viral load and an increase in CD4 counts (group 2 patients), IL-2R expression is significantly lower than in group 1 patients. Moreover, cells involved in cellular immunity and CD4 T lymphocytes have the capacity to respond to IL-2 after TCT. These results allow us to anticipate a beneficial role of IL-2 immunotherapy in combination with TCT.

B-Lymphocytes↗
PubMed1998

Further analysis of interleukin-2 receptor subunit expression on the different human peripheral blood mononuclear cell subsets.

We have investigated the expression of the three components of the interleukin-2 receptor (IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma) on the surface of the various peripheral blood mononuclear cell (PBMC) subsets by flow cytometry analysis. The PBMC were immediately isolated (ficoll) from blood collected on heparin as anticoagulant. The three IL-2R components are absent or only marginally detectable on CD4 T lymphocytes. No expression of the IL-2R chains is found for the B lymphocytes. In most donors, the three chains are not detectable on CD8 T lymphocytes, but for a few of them, IL-2Rbeta or IL-2Rgamma are clearly expressed. CD56 high (IL-2Ralpha+) and CD56 low (IL-2Ralpha-) natural killer (NK) cells express IL-2Rbeta, but not IL-2Rgamma. IL-2Rgamma is expressed by monocytes of all donors although with variable intensity. When blood is collected on other anticoagulants or when cells are isolated 1 day after collection, IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma are largely expressed on the surface of most PBMC. This observation provides a possible explanation for divergent data previously reported on IL-2R expression. Finally, we show that IL-2Rgamma, which is not detectable on the cell surface of lymphocytes, is nevertheless expressed and stored as an intracellular component. This result is in agreement with the constitutive expression of the IL-2Rgamma gene and suggests a specific regulatory mechanism for IL-2Rgamma membrane translocation.

Anticoagulants↗
PubMed1997

[Consequences for labile blood products of leukocyte depletion by whole blood filtration using the Leucoflex LST1 in-line filter. Evaluation of the Leucoflex LST1 filter].

The aim of this study is to evaluate the effects of whole blood filtration after a storage time of 20-24 hours at laboratory temperature using the in line filter Leucoflex LST1. The study concerns 49 blood donations in which we studied leukocyte depletion, proteins (IgG, IgA, IgM, haptoglobin, C3, C4), coagulation factors (fibrinogen, factors XII, XI, IX, VIII, V, proteins S and C, plasminogen, tPA, D-Dimers, PDF) at day 1, the parameters of conservation (ATP, 2-3 DPG, extra cellular potassium, haemolysis, pH) of red blood cell concentrates (RCCs) and bacteriological sterility at day 1 and 42. Despite a correct leukocyte depletion (mean depletion of 3.96 log), a 10 fold higher mean level of residual leukocytes/unit than with buffy coat poor RCC filtration (0.514.10(6) vs 0.051.10(6)) is observed. Moreover a lot of concentrates are not in accordance with French regulations (7/42 with more than 1.10(6) leukocytes/unit). The variation of the rates of IgG, IgA, IgM, haptoglobin, C4 and protein C is not significant. For the others there is a slight decrease with a mean level remaining in a physiological range. No sign of activation is noted. The sterility assays remain negative and the RCC conservation is not altered. In conclusion, even if the quality of the leukocyte depletion is not satisfactory in our study and has to be stated more precisely by multicenter studies, the whole blood filtration does not alter the quality of the derived components and allows us obtain RCC in a bigger volume and containing more haemoglobin than with the classical procedure after removing the buffy-coat [10].

Blood↗
PubMed1997

[Results of ultrasonographic and cytologic follow-up of 311 initially non-suspicious thyroid nodules].

The follow-up of initially non suspect thyroid nodules after fine needle biopsy is not completely worked out. Since 1985, we have entered upon a prospective study concerning the followup of thyroid nodules supposed to be benign after initial evaluation. What are the nature and the frequency of means to be used for their follow-up? Three hundred and eleven nodules are followed up on a mean duration of 2.44 years. The follow-up of 65 of them is 4 years or more. The follow-up of 120 others is 3 to 4 years; 197 nodules are followed up during 2 to 3 years. A physical examination, an ultrasonography completed with a fine needle biopsy or an ultrasonically guided fine needle biopsy are worked out every year. Twenty-three per cent of initial biopsies are non significant and 90% of them are ultrasonically guided biopsies. At the end of the study, the repeating biopsies reduce to 6% the non significant biopsies ratio. Four histological thyroid cancers are detected in three female patients 1 year, 2 years and 5 years after the initial evaluation. Ultrasound alterations of nodules are observed in case of very suspect biopsies. Ninety-six per cent of the followed up thyroid nodules remain not cytologically suspect. These findings allow us to propose the following guidelines for the assessment of a non suspect thyroid nodule: half-yearly or yearly physical examination, yearly or biennial ultrasonography, repeat biopsy after 2 or 3 years when clinical or ultrasound suspect modification is wanting.

Adolescent↗
PubMed1995

Risk factors for hepatitis A infection in France: drinking tap water may be of importance.

The prevalence of serologic markers for hepatitis A was investigated in 936 French male military recruits from October 1992 to June 1993. Data were collected in order to assess the evolution of seroprevalence level according to the decline observed for several years and to appreciate the importance of potential risk factors. The overall prevalence of antibody against hepatitis A virus was 16.3%. The prevalence was higher among those with high number of siblings and whose Father's occupation falls into low professional class categories. Multivariate analysis found that high level of seroprevalence was also associated with tap water consumption (odd ratio (OR) = 1.56; p < 0.04), overseas travels (OR = 2.26; p < 0.001) and was higher for recruits reporting an history of clinical jaundice (OR = 2.27; p < 0.01). Together with more anticipated factors, tap water consumption may be of importance in France and this study points out the potential part taken by chlorinated water.

Adolescent↗
PubMed1995

[Erythrocyte concentrated and air transport: evaluation of quality].

The available supply of blood products determines the resuscitation capabilities after natural disasters or armed conflicts. Air flight reduces transport delay. The purpose of the present study was to assess the quality of red blood cell concentrates (RCC) immediately after air transport (j0) and after preservation (j30). We exposed RCC to a real air flight (P) or to low pressure (V) corresponding to an air transport in experimental conditions. The quality of RCC was altered immediately after only the real air flight (hemolysis P = 0.11% versus 0.04% for witness (T)). These alterations were not observed immediately after the simulated flight (hemolysis V = 0.02%). After preservation, the RCC was altered both for those exposed to an air flight or to a low pressure (hemolysis: P = 1.09%, V = 0.78%, T = 0.25%). Other biological alterations (pH, K+, hemoglobin level) suggested that pressure variations are not the only one responsible constraint. Other studies are necessary to point the mechanism and the optimal life of conservation after flight. Exposure of preserved red blood cells to air transport alters their therapeutic properties during aging. However, the therapeutic use of RCC thus transported is not questioned.

Air Pressure↗