Giant cell arteritis-related aortitis with positive or negative temporal artery biopsy: a French multicentre study.

Objective: To compare the clinical presentation and outcome of giant cell arteritis (GCA)-related aortitis according to the results of temporal artery biopsy (TAB).Method: Patients with GCA-related aortitis diagnosed between 2000 and 2017, who underwent TAB, were retrospectively included from a French multicentre database. They all met at least three American College of Rheumatology criteria for the diagnosis of GCA. Aortitis was defined by aortic wall thickening > 2 mm on computed tomography scan and/or an aortic aneurysm, associated with an inflammatory syndrome. Patients were divided into two groups [positive and negative TAB (TAB+, TAB-)], which were compared regarding aortic imaging characteristics and aortic events, at aortitis diagnosis and during follow-up.Results: We included 56 patients with TAB+ (70%) and 24 with TAB- (30%). At aortitis diagnosis, patients with TAB- were significantly younger than those with TAB+ (67.7 ± 9 vs 72.3 ± 7 years, p = 0.022). Initial clinical signs of GCA, inflammatory parameters, and glucocorticoid therapy were similar in both groups. Coronary artery disease and/or lower limb peripheral arterial disease was more frequent in TAB- patients (25% vs 5.3%, p = 0.018). Aortic wall thickness and type of aortic involvement were not significantly different between groups. Diffuse arterial involvement from the aortic arch was more frequent in TAB- patients (29.1 vs 8.9%, p = 0.03). There were no differences between the groups regarding overall, aneurism-free, relapse-free, and aortic event-free survival.Conclusion: Among patients with GCA-related aortitis, those with TAB- are characterized by younger age and increased frequency of diffuse arterial involvement from the aortic arch compared to those with TAB+, without significant differences in terms of prognosis.

Immunosuppressive activity of a subline of the mouse EL-4 lymphoma. Evidence for minute virus of mice causing the inhibition.

Filtered culture fluids from the early in vitro passages of a subline of the C57BL/6 mouse EL-4 lymphoma, EL-4(G-), were strongly inhibitory for BABL/c vs. C57BL/6 mixed lymphocyte cultures (MLC). The inhibitory activity could be preserved by storage at -75 degrees C or 4 degrees C, thus allowing its further characterization. The inhibitory factor was particulate (nondialyzable, sedimentable at 100,000 g for 1 h), very small (recovered after 0.10 mum filtration), sensitive to UV irradiation, but heat stable (56 degrees C, 1 h) and resistant to chloroform. It was infectious, since later, noninhibitory passages of EL-4(G-) tissue culture cells became strongly inhibitory upon inoculation with the culture fluid. This data was consistent with the inhibitory factor being an infectious virus. Virus analysis by mouse antibody production tests revealed that viruses were indeed present in EL-4(G-) ascites cells and in the culture fluid, and not in a late passage of EL-4(G-) tissue culture cells which were not inhibitory. Neutralization of the inhibitory factor was achieved by pretreatment with ascitic fluid or with the sera raised against those (EL-4(G-)-derived materials which contained viruses. Mouse reference immune sera against minute virus of mice (MVM) completely neutralized the inhibitory factor in the culture fluid or in EL-4(G-) ascites cells. Two prototype MVM strains, and one Kilham rat virus preparation, did not inhibit the mouse MLC. Thus, the possibility exists that a variant of MVM, or an unidentified virus, has been grown and selected for in EL-4(G-) cells and recognized, due to its immunosuppressive characteristics. In any event, immunosuppression by EL-4(G-) cells was not mediated by the tumor cells, their metabolic products, or associated endogenous type C viruses, but by an exogenous virus, most likely a variant MVM with immunosuppressive characteristics. This adds weight to a parallel observation from our laboratory on the immunosuppressive effects of Kilham rat virus in rat lymphocyte cultures.

[Reliability and validity of a workbook for assessment of professional competencies of internal medicine residents]. / Évaluation multicentrique de la reproductibilité et de la validité d'un carnet d'évaluation des compétences professionnelles des internes de médecine interne.

INTRODUCTION: Though several assessment tools for resident professional skills based on workplace direct observation have been validated, they remain scarcely used in France. The objective of this study was to evaluate the reliability and the validity of a workbook including several assessment forms for different components of the professional competency. METHODS: Three assessment forms have been tested over a period of 6 months in a multicentric study including 12 French internal medicine departments: the French version of the mini-CEX, an interpersonal skills assessment form (OD_CR) and the multisource feedback form (E_360). Reliability has been assess using the intra-class correlation coefficient (ICC) and the Cronbach alpha coefficient. Arguments for validity have been provided looking at the ability of the forms to detect an increase in the scores over time and according to the level of experience of the resident. RESULTS: Twenty-five residents have been included. The Cronbach alpha was of 0.90 (n=70) with the mini-CEX, 0.89 with the OD_CR (n=62) and 0.77 with the E_360 (n=86). ICC showed a wide variation according to the items of the mini-CEX and the OD-CR probably due to the poor number of observations performed by residents. The scores of most of the items of these two forms increased between M1 and M6. The scores of the E_360 were high: 7.3±0.8 to 8.3±2.4 (maximum 9) and did not vary according to the level of experience. CONCLUSION: This study suggest that it would be difficult to ensure a sufficient reliability for professional skills assessment using these tools given our available current human and material resources. However, these assessment forms could be added to the resident portfolio as supports for the debriefing in order to document their progression during their formation.

Cytochrome c biogenesis in mitochondria.

As part of the respiratory chain, c-type cytochromes are essential electron transporters. They are characterized by the covalent attachment of a heme prosthetic group. The biogenesis of these proteins includes all the processes leading to this fixation. Yeast and animals have evolved a comparatively simple mechanism relying on cytochrome c heme lyases. In contrast, plant mitochondria have kept a maturation pathway inherited from their prokaryote ancestor. It involves Ccm proteins encoded in both the nuclear and the mitochondrial genomes of plants. These proteins compose a heme delivery pathway, include an ABC transporter, a redox protein and a putative heme lyase.

[Massive rhabdomyolysis revealing a McArdle disease]. / Rhabdomyolyse massive révélant une maladie de McArdle.

INTRODUCTION: McArdle's disease is an autosomal recessive glycogenosis caused by deficiency of muscle glycogen phosphorylase resulting in glycogen accumulation in the skeletal muscle. Typically, McArdle's disease is characterized by exercise intolerance with muscle cramps and myoglobinuria. CASE REPORT: We report a 20-year-old woman with massive rhabdomyolysis and acute renal failure revealing a McArdle's disease. DISCUSSION: Although muscle impairment is constant in McArdle's disease, massive rhabdomyolysis with severe acute renal failure has been rarely reported as a presenting feature. The mechanisms and therapeutic implications of renal injury are discussed.

Clinical effects of infusions into chimpanzees of primed autologous cultured T-cells.

As a model to study the possible early side effects of cultured T-cells (CTC) as a potential for adoptive cellular immunotherapy of human tumors, chimpanzees received iv infusions of 10(9) autologous, mixed lymphocyte culture-primed CTC. Complete blood counts, urinalyses, chest X-rays, blood chemistries, and serum immunoelectrophoresis were normal, and serologic studies were negative throughout the 3 weeks of observation. Serial transaminase levels were followed in 2 chimps, and mild increases in serum glutamic-oxaloacetic transaminase were seen in both and serum glutamic-pyruvic transaminase in 1 at 24 hours following each CTC infusion, but the levels returned to normal within 7 days. A liver biopsy specimen was normal. Fluorescence-activated cell sorter analysis of cells incubated with day 28 serum revealed weak labeling of only phytohemagglutinin (PHA)-stimulated lymphoblasts and of CTC, suggesting that a weak anti-PHA antibody was generated. These studies indicate that infusions of autologous, in vitro-primed CTC are accompanied by little clinical toxicity in the chimp model but that they may be weakly immunogenic.

Interferon and prostaglandins: effects on human natural and lectin-induced cytotoxicity.

Effects of interferons (IFN) and E-series prostaglandins (PGE) were evaluated on subpopulations of human peripheral blood mononuclear lymphocytes (PBL) that mediate natural killer (NK) activity, antibody-dependent cell-mediated cytotoxicity (ADCC), or lectin-induced cellular cytotoxicity (LICC). When PBL were separated into subpopulations depending on the presence or absence of receptors for sheep erythrocytes (E+ or E-, respectively) or for the Fc gamma receptor (Fc gamma R+ or Fc gamma R-, respectively), LICC was mainly associated with the E+Fc gamma R- cells and to a considerably lesser extent with E+Fc gamma R+ cells. In contrast, NK activity and ADCC were associated with the E+ and E- subpopulations that had Fc gamma R. IFN treatment had stronger effects on the Fc gamma R+ subpopulations. Boosting of LICC occurred maximally in the E+Fc gamma R+ subpopulation, and the activity of the E+Fc gamma R- cells increased only modestly. IFN had a greater augmenting effect on the NK activity and ADCC of E+Fc gamma R+ cells than on E-Fc gamma R+ cells. PGE strongly inhibited all three types of cell-mediated cytotoxicity and was effective on IFN-boosted cells as well as on untreated cells.

Wheat mitochondria ccmB encodes the membrane domain of a putative ABC transporter involved in cytochrome c biogenesis.

Assembly of cytochromes c is mediated by different proteins depending on the organism and organelle considered. In land plants, mitochondria follow a pathway distinct from that of yeast and animal mitochondria, more similar to that described for alpha- and gamma-proteobacteria. Indeed, in plant mitochondria, four genes were identified based on the similarities of their products with bacterial proteins involved in c-type cytochrome maturation. We report the characterisation of one of these mitochondrial genes in Triticum aestivum, TaccmB, which is proposed to encode a subunit of an ABC transporter. The transcript extremities were mapped and cDNA sequencing revealed 42 C to U editing positions in the 618 nucleotide long coding region. This high editing rate affects the identity of 32 amino acids out of 206. Antibodies directed against wheat CcmB recognise a 28 kDa protein in an enriched inner mitochondrial membrane protein fraction, a location which is in agreement with the high hydrophobicity of the protein and its function as a putative transmembrane domain of an ABC transporter involved in cytochrome c and c1 biogenesis in plant mitochondria.

Transcription initiation and RNA processing in the mitochondria of the red alga Chondrus crispus: convergence in the evolution of transcription mechanisms in mitochondria.

The mitochondrial DNA (mt DNA) of the red alga Chondrus crispus is shown to be transcribed into two large RNA molecules. These primary transcripts are cleaved once, at the level of a tRNA, then the resulting products are processed via multiple maturation events into either mono- or poly-cistronic RNAs. Transcripts were detected for all genes and open reading frames, except for rps11 and orf172. For both transcription units the initiation of transcription was mapped by in vitro RNA capping and primer extension experiments within inverse repeated sequences at the north pole of the molecule. Consistent with primer extension mapping, putative promoter motifs sharing significant similarities with both chicken and Xenopus mitochondrial promoters were found in the C. crispus mitochondrial genome. Altogether C. crispus mitochondrial DNA appears to be transcribed as animal mtDNA is, suggesting that transcription mechanisms in mitochondria are dependent on the overall organization of the mitochondrial genome irrespective of the eukaryotic phylogeny.

Complete sequence of the mitochondrial DNA of the rhodophyte Chondrus crispus (Gigartinales). Gene content and genome organization.

The complete nucleotide sequence of the circular mitochondrial (mt) DNA from the red alga Chondrus crispus was determined (25,836 nucleotides, A+T content 72.1%). Fifty one genes were identified. They include genes encoding three subunits of the cytochrome oxidase (cox1 to 3), apocytochrome b (cob), seven subunits of the NADH dehydrogenase complex (nad1 to 6, nad4L), two ATPase subunits (atp6 and atp9), three ribosomal RNAs (rrn5, srn and lrn), 23 tRNAs and four ribosomal proteins (rps3, rps11, rps12 and rpl16). Two subunits of the succinate dehydrogenase complex (sdhB and sdhC), usually found on nuclear genomes, are also located on the mtDNA of C. crispus. One group IIb intron is inserted in the tRNAIle gene. Six potentially functional open reading frames were identified, four of them having counterparts among green plant mtDNAs. The use of a modified genetic code and the absence of RNA editing, previously reported for the cox3 gene, appears as a general characteristic of this molecule. Mitochondrial genes are encoded on both DNA strands, in two opposite major transcriptional directions, suggesting the existence of two main transcriptional units. Two long and stable stem-loops were identified in intergenic regions, which are believed to be involved with transcription and replication. The main structural features of this genome are compared with the overall organization of mtDNAs and are discussed in view of the evolution of mitochondria.

[A case of alcohol-induced ketoacidosis?]. / Une acidocétose alcoolique?

We report a case of severe ketoacidosis. Initially the patient showed metabolic acidosis, the anion gap was positive and there was neither hyperlactatemia nor intoxication with acid substances. As the rate of glycemia was high (17.8 mmol/L), the diagnosis of diabetic ketoacidosis was proposed. Under treatment with continuous IV injection of insulin, hypoglycemia (1.8 mmol/L) appeared rapidly, while urine bioreactive test was positive for ketonuria, but negative for glycosuria. We finally concluded that it was an alcoholic ketoacidosis. The history of the patient confirmed the diagnosis : chronic alcoholism with recent increased of alcohol intake which provoked vomiting and fasting. This case report shows the difficulty in distinguishing between alcoholic ketoacidosis and diabetic ketoacidosis. We discuss the diagnostic strategy and particularly biologic data in the light of pathophysiologic mechanism of alcoholic ketoacidosis.

Cryopreserved human cultured T cells as responder cells for the quantitative measurement of interleukin-2: improvement of the assay.

Large batches of human cultured T cells (CTC) were cryopreserved for later use as responder cells in a proliferation assay for measurement of interleukin (IL)-2 activity. Cryopreservation of CTC could be carried out without considerable loss in viability and cryopreserved and fresh cells showed equally good responses to IL-2. The conditions of IL-2-dependent CTC growth were analyzed, which led to a better evaluation of test results, and had important implications for the calculation of relative IL-2 activity. The repeated use of the same batch of cryopreserved CTC reduced test variability and provided an assay system that allows reliable and reproducible measurement of human IL-2 activity.

Suppression of mixed lymphocyte response in mice bearing primary tumors induced by murine sarcoma virus.

Mixed lymphocyte culture (MLC) responses of spleen cells from mice bearing tumors induced by murine sarcoma virus of the Moloney type (MSV) against allogeneic spleen cells were found to be markedly depressed, as estimated by three parameters: lymphoblast counts, 3H-thymidine incorporation (TI), and cell-mediated lysis (CML). While all three parameters were definitely depressed in comparison to the normal controls, TI was depressed to a greater degree than lymphoblast counts and CML. MSV spleen cells also had a suppressive effect on the MLC responses of normal spleen cells in third party type of experiments. The cells mediating this effect were radioresistant non-T cells, which were removed by adherence columns and were inactivated by carrageenan. These data suggested that the supressor cells were macrophages. Serum from MSV tumor-bearing mice had a greater suppressive effect than did normal mouse serum. Both the suppressor cells and the suppressive serum factors may play an important role in the immunosuppression observed in tumor-bearing hosts.

Effect of cyclosporin A on the early activation of human T helper lymphocytes: inhibition of RNA-synthesis and modification of the expression of activation antigens.

The ability of cyclosporin A (CS-A) to inhibit induced lymphocyte activation and to modify expression of membrane receptors was assessed on human T helper cells. Flow cytometric cell cycle analyses of acridine orange-stained cells showed that CS-A (0.5 micrograms/ml) inhibits the G0-G1 activation process of a substantial proportion of PHA- and Con A-stimulated lymphocytes. The expression of Tac, OKT9 and 4F2 antigens (previously shown to be expressed or increased on activated cells) was investigated by immunofluorescence. Fewer cells expressed the Tac and OKT9 antigens after activation in presence of CS-A, but the percentage of 4F2-positive cells remained unchanged. Analyses of receptor densities measured by fluorescence intensity revealed for all three investigated antigens a decreased receptor density on positive cells in presence of CS-A. Thus, CS-A not only inhibited cell activation (G0-G1 transition) and the expression of Tac, OKT9 and 4F2 antigens, but it also diminished the number of Tac, OKT9 and 4F2 antigens per cell. Assessing specifically the activation of OKT4 (helper) and OKT8 (cytotoxic) cells after 24 h, either by double-fluorescence or by cell fractionation with anti-OKT4 or anti-OKT8 antibodies plus complement, showed that preferentially OKT4 cell activation as well as expression of Tac and OKT9 antigens on those cells was inhibited in the presence of CS-A.

Cultured T cells from patients with T cell chronic lymphocytic leukemia demonstrate a normal phenotype.

Peripheral blood mononuclear cells from eight patients with the rare T-cell form of chronic lymphocytic leukemia were isolated and cultured with Interleukin-2 (IL-2). In all but one case, cultured T-cells (CTC) were established. Various culture conditions were tested for their effectiveness; feeder layers proved valuable for expanding the cultures to large volumes. The CTC remained IL-2 dependent. Analysis of surface determinants on these CTC showed a polyclonal proliferation of T-cells. The distribution of subset markers in the patients' CTC population had completely changed in comparison to the "fresh" peripheral blood cell population but was similar to CTC initiated from healthy donors. Our data suggest that the patients' few contaminating normal T-lymphocytes expanded in culture, while the malignant cells were unresponsive to IL-2. This conclusion is supported by growth characteristics and morphology of the CTC.