[Comparative study of the BACTEC 9000 MB system and Lowenstein Jensen media for mycobacterial culture]. / Etude comparative du système BACTEC 9000 MIB et du milieu de Lowenstein Jensen pour la culture des mycobactéries.

An automated system for mycobacteria culture, BACTEC 9000 MB, was compared with Lowenstein Jensen culture. On a total of 4,484 pulmonary and extrapulmonary human clinical samples, 126 (2.8%) were positive for mycobacteria on Lowenstein Jensen (LJ) medium; 105 (2.34%) were identified as Mycobacterium tuberculosis and 39 (1.10%) as non tuberculosis mycobacteria. The mean time of detection of Mycobacterium tuberculosis on the 131 positive samples was reduced to approximately ten days with BACTEC 9000 MB compared to the LJ (17.6 versus 27.38 days). Through the results of this comparative study, we confirmed that BACTEC 9000 MB is a more efficient system than LJ for culture detection of all mycobacteria from various sites samples.

[Evaluation of reticulocyte count on Cell-Dyn 3500 automate: comparison with a flow cytometry technique]. / Evaluation de la numération des réticulocytes sur automate Cell-Dyn 3500: comparaison avec une technique par cytométrie en flux.

Cell-Dyn 3500 automate (Abbott) provides reticulocyte count using a recent software, after ribosomal RNA colouring with methylene blue reagent. The aim of this study was to evaluate results from Cell-Dyn 3500, and to compare them with the routine laboratory technique by flow cytometry (FacScan, Becton-Dickinson). Cell-Dyn 3500 analytical parameters (inter- and intra-assay precision, sample-to-sample contamination) were good and in accord to manufacturer's specifications. Reticulocyte values from blood samples kept at 4 degrees C during 3 days were unchanged. Usual values in 145 normal patients were found between 71.3 and 78.3 G/l with Cell-Dyn 3500, between 119.3 and 130.2 G/l with FacScan. Both techniques were compared in 87 patients with various anemias: Cell-Dyn 3500 showed more frequently high reticulocyte values in regenerative anemias (hemorrhagic), but was less performant for classification of aregenerative anemias. Reticulocyte count with Cell-Dyn 3500 is a semi automatic, easy to perform and swift technique, using no toxic reagent but unitary test tubes kept at room temperature. The test cost is however high, and Cell-Dyn 3500 cannot be used during the analysis.

[Variability of INR due to thromboplastin. Comparison of two recombinant thromboplastins and one rabbit thromboplastin]. / Variabilité de l'INR en fonction du réactif thromboplastine utilisé. Comparaison de deux thromboplastines recombinantes et d'une thromboplastine de lapin.

We have compared the INR obtained with three different thromboplastin reagents: one rabbit and two recombinant tissue factor thromboplastins using the same coagulometer. A preliminary study has shown that freezing of plasmas at -80 degrees centigrade causes a 6% increase in INR. We did this experiment on 57 plasma samples from patients receiving oral anticoagulant therapy, none of them receiving heparin. Results show that global prothrombin activity expressed in percentage is significantly lower with recombinant tissue factors than with rabbit thromboplastin. ISI of one of the two recombinant thromboplastins did not seem to be appropriate to our coagulometer highpointing the variability of INR due to the coagulation analyzer. This underlines the necessity for each laboratory to assess the ISI value provided by the manufacturer according to its working conditions. This study suggests that the results of prothrombin time should be exclusively expressed in INR for patients treated with oral anticoagulants.

Gel-test: interpretation and value of a new technique for the detection of irregular antibodies.

Here we report on our experience with the use of a 'Gel-Test' (DiaMed-ID Micro Typing System) technique for the detection and identification of irregular antibodies in a general hospital. This easy-to-use, standardized technique poses the question of the impact of its sensitivity on the specificity of the results. Of the 10% of observed positive reactions, 3.7% were irregular antibodies, 3.8% papain auto-antibodies, 1% cold antibodies and 2% not elucidated. Two hundred and eighteen irregular antibodies identified and titred with the 'gel-test' system were tested in parallel by 'tube' method. Sixty-three of these antibodies (29%) were not detected by the 'tube' method. While anti-Kell was always detected by both methods, we found the following false natives with the tube method: 15% anti-D, 32% anti-E, 42% anti-Cw and 58% anti-Lea. 68% of these false negatives had a low titre. The immunoglobulin class of the anti-E was studied; the sensitivity of the 'gel-test' system was associated with IgM in the anti-E. The sensitivity and standardization of the 'gel-test' technique guarantee greater safety in blood transfusion and increase efficiency in the prevention of foeto-maternal stimulation of anti-D.

[Nosocomial Pseudomonas pickettii infection. Danger of the use of ion-exchange resins]. / Infection nosocomiale à Pseudomonas pickettii. Danger de l'utilisation des résines échangeuses d'ions.

In a recent nosocomial outbreak of Pseudomonas pickettii infection at the general hospital of Corbeil-Essonnes, France, two patients were moderately affected, but two others, who were diabetic, died of septicemia. The infection was transmitted by 0.05% aqueous solutions of chlorhexidine, the treatment of water for these solutions being the cause of contamination. The ion-exchange resin in the deionization cartridges allowed the surviving bacteria in the city water supply to grow while the bacteriological filters downstream only lowered the contamination level. The 0.05% chlorhexidine aqueous solutions failed to prevent growth up to 4 X 10(6) bacteria/ml. P. pickettii is resistant to aminoglycosides and colistine.

[Pulmonary infection caused by a rare mycobacterium, Mycobacterium malmoënse]. / Infection pulmonaire due à une mycobactérie rare Mycobacterium malmoënse.

The present case report is on a patient treated for tubercle in 1949 by an artificial pneumothorax. Thirty three years after the initial illness some radiological changes occurred suggesting a recurrence, especially as a bacteriological examination showed the presence of acid-alcohol fast bacilli on direct smear. Triple therapy (Isoniazid, Rifampicin, Streptomycin) was then prescribed, and was followed by a radiological improvement, even though the sputum remained positive. After multiple seedings, it was possible to isolate from 11 tubes and 2 expectorations a rare strain of mycobacterium: mycobacterium malmoense. The present observation seems to be the first indisputable French case of infection by this bacterium. From the opportunity presented by this observation the bacteriological characteristic of this mycobacterium, as well as the clinic aspects of the infection are discussed.

[Viral type particles in the germinal centers during a lymphadenopathic syndrome related to AIDS]. / Mise en évidence de particules de type viral dans les centres germinatifs au cours d'une syndrome lymphadénopathique relié au SIDA.

The identification of virus-like particles in the germinal centers of an AIDS-related lymph node with histological findings of group IA is reported. A 23 year-old man, intravenous drug user, presents an inversion of T helper/T suppressor cell ratio and a peripheral generalized lymphadenopathy, suggesting a diagnosis of ARC. Lymph node biopsy shows follicular hyperplasia and features consistent with group IA of AIDS-related lymphadenopathy. Immunohistochemical study reveals an increase of intrafollicular T8+ lymphocytes. Electronmicroscopic examination of follicles demonstrates the presence of particles showing features of viral nucleocapsids; these particles are seen between the cytoplasmic processes of follicular dendritic cells. Pathologic findings associated with lymphoid follicular hyperplasia in AIDS prodromal period are examined. The importance of lymph node biopsy with histological, immunohistochemical and ultrastructural studies, in patients at high risk for AIDS, is demonstrated. The detection of type D viral particles suggestive of retrovirus is in accordance with results of virologic studies which indicate the involvement of a retrovirus (called LAV or HTLV III) in the etiology of the disease.

[Effect of 2-mercaptoethanol on immunoglobulin M in toxoplasmosis and rubella]. / Action du 2 mercapto-éthanol sur les immunoglobulines M de la toxoplasmose et de la rubéole.

2 mercapto-ethanol (2 M-E) can be used to demonstrate IgM immunoglobulins to both toxoplasmosis and to measles, but while the action of this reagent is easily confirmed in the course of agglutination reactions with toxoplasma, it is only straightforward in certain circumstances in the course of the inhibition of haemagglutination reaction with measles virus. The agglutination reaction is very sensitive for this group of immunoglobulins: the depolymerization of toxoplasmosis IgM by 2 M-E is well demonstrated in total serum. The inhibition of haemagglutination reaction is sensitive for IgM and IgG, but the much higher concentration of IgG often masks the immunological activity of the IgM; the depolymerization of measles IgM by 2 M-E is only barely demonstrated on the IgM fraction. The use of 2 M-E is also a valuable means of confirming the fractionation obtained by filtration chromatography.

[Lymphadenopathy caused by hemophagocytic sinus histiocytosis (Destombes-Rosai-Dorfman syndrome). Immunologic and histopathologic study of a new case]. / Lymphadénopathie par histiocytose sinusale hémophagocytaire (syndrome de Destombes-Rosai-Dorfman). Etude immunologique et histo-pathologique d'un nouveau cas

The case reported is one of lymphadenopathy due to haemophagocytic sinusal histiocytosis which had progressed for more than 10 years before resulting in death at the age of 58 years. In this advanced form, all superficial and deep nodes were involved. In addition to histiocytic hyperplasia, with haemophagocytosis and lipid overload, there was plasmocytic hyperplasia, i.e. B-lymphocytes, with polyclonal hypergamma-globulinaemia and an increase in the levels of many antibodies, in particular against rubella and the Epstein-Barr virus. The aetiopathological significance is discussed, in particular the role of an infection due to the EB virus.