Safety and immunogenicity of a recombinant Plasmodium falciparum AMA1-DiCo malaria vaccine adjuvanted with GLA-SE or Alhydrogel® in European and African adults: A phase 1a/1b, randomized, double-blind multi-centre trial.

BACKGROUND: Plasmodium falciparum Apical Membrane Antigen 1 Diversity Covering (PfAMA1-DiCo) candidate vaccine is a formulation of three recombinant variants of AMA1 designed to provide broader protection against parasites with varying AMA1 sequences. METHODS: In this staggered phase Ia/Ib randomized, double blind trial, healthy French adults received AMA1-DiCo with either Alhydrogel® (n=15) or GLA-SE (n=15). Following a safety assessment in French volunteers, GLA-SE was chosen for the phase Ib trial where healthy Burkinabe adults received either AMA1-DiCo/GLA-SE (n=18) or placebo (n=18). AMA1-DiCo (50µg) was administered intramuscularly at baseline, Week 4 and 26. RESULTS: AMAI-DiCo was safe, well tolerated either with Alhydrogel® or GLA-SE. In European volunteers, the ratios of IgG increase from baseline were about 100 fold in Alhydrogel® group and 200-300 fold in GLA-SE group for the three antigens. In African volunteers, immunization resulted in IgG levels exceeding those observed for the European volunteers with a 4-fold increase. DiCo-specific IgG remained higher 26weeks after the third immunization than at baseline in both European and African volunteers. Induced antibodies were reactive against whole parasite derived from different strains. CONCLUSION: AMA1-DiCo vaccine was safe and immunogenic whatever the adjuvant although GLA-SE appeared more potent than Alhydrogel® at inducing IgG responses. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov NCT02014727; PACTR201402000719423.

Evaluation of the interlaboratory concordance in quantification of human immunodeficiency virus-specific T cells with a gamma interferon enzyme-linked immunospot assay.

The gamma interferon (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay is a reference method for the ex vivo monitoring of antigen-specific T cells and a primary tool for assessing clinical trials of human immunodeficiency virus (HIV) or cancer vaccines. Four experienced laboratories in Paris compared their results with this method by exchanging frozen blood samples from eight HIV-seronegative and eight HIV-seropositive subjects. Each laboratory measured the IFN-gamma-producing cells specific for HIV, Epstein-Barr virus, cytomegalovirus, and influenza using the same set of peptides and the same ELISPOT reader but its own ELISPOT technique. The cutoff values for positive responses (50 or 100 spot-forming cells/10(6) peripheral blood mononuclear cells over background) were consistent with the binomial statistic criterion. The global qualitative concordance, as assessed by the kappa index, ranged from 0.38 to 0.92, that is, moderate to excellent, and was better for non-HIV 9-mer peptide pools than for HIV 15-mer peptide pools. The interlaboratory coefficient of variation for the frequency of virus-specific T cells was 18.7% (data are expressed on a log scale). Clustering analysis of HIV-positive subjects showed qualitative agreement for ELISPOT results from all four laboratories. Overall, the good interlaboratory qualitative concordance of IFN-gamma ELISPOT assays with only the peptide source and ELISPOT reader in common suggests that a qualitative comparison of interlaboratory findings is feasible. Nonetheless, a single set of standard operating procedures should be used in multicenter trials to improve standardization.

CD4 T cell recovery is slower in patients experiencing viral load rebounds during HAART.

To determine whether viral load rebounds during HAART impact on CD4+ T cell recovery and immune reconstitution, we studied a prospective cohort of 355 antiretroviral naive patients enrolled to be randomized in a trial of three strategies of induction/maintenance HAART. The extent of immune reconstitution in blood through 72 weeks of antiretroviral treatment was evaluated. Lymphocyte subset markers (CD4, CD8, CD45RA, CD62L, CD16, CD19), activation markers (HLA-DR, CD38, CD25) were performed by cytometry analysis. Our results showed that plasma HIV-1 RNA was suppressed to below 500 copies per ml through week 72 in 240 patients (group 1) while the remaining 115 patients experienced at least one viral rebound (group 2). At baseline, CD4 cell count was higher and HIV-1 RNA was lower in group 1 than in group 2. Over 72 weeks, mean increase in CD4+ T cell count was 0.32 cell/mm3/day in group 1 and only 0.14 cell/mm3/day in group 2 (P < 0.0001). However, the patterns of changes in CD4+ and CD8+ T cell subsets during therapy were very similar across the two groups with only subtle and very limited differences. We conclude that permanent control of HIV replication could be necessary for faster immune reconstitution.

Assessment of the virulence of Listeria monocytogenes: agreement between a plaque-forming assay with HT-29 cells and infection of immunocompetent mice.

Some Listeria monocytogenes strains not related to clinical cases have been found to exhibit a low virulence level in mice as well as in an in vitro test using Caco-2 cells. The purpose of this study was to validate a new in vitro test of virulence based on a plaque-forming assay (PFA) using a HT-29 cell monolayer with 118 Listeria strains. The use of HT-29 cells in 96-well tissue culture plates allowed the testing of 30 strains per day and providing results in 24 h. In addition. statistical analyses demonstrated the reproducibility and repeatability of the PFA. No quantitative relationship was observed between the virulence of the strains and the hemolytic titer or the cytotoxic effects on HT-29 cells. In contrast, good agreement was observed between virulence assessed after subcutaneous (SC) infection and virulence obtained by PFA. Three groups of L. monocytogenes strains (avirulent, hypovirulent and fully virulent) were established by comparison of the clinical origin of the strains, the number of immunocompetent contaminated mice and the numbers of Listeria strains recovered in the spleen after SC infection. With one exception, i.e. a clinical case of L. seeligeri (sensitivity 0.98), the PFA successfully detected the virulent strains only (specificity 1). Decision-tree algorithms performed by SAS and S-Plus demonstrated that this tissue culture assay discriminated between the avirulent and hypovirulent strains and the virulent strains. This test could therefore be an alternative to in vivo tests, allowing grading of virulence.

Microbial thiamin metabolism in the rumen simulating fermenter (RUSITEC): the effect of acidogenic conditions, a high sulfur level and added thiamin.

The effects of acidogenic conditions, a high S level and the addition of thiamin on the rumen microbial metabolism of thiamin were investigated in vitro in a semi-continuous fermenter (RUSITEC), using a factorial design. Acidogenic conditions were obtained by simultaneously increasing the starch: cellulose ratio and the amount of solid substrate fed, and by decreasing the buffering capacity of the liquid phase of the fermenter. S in the form of sulfate was supplied at two levels, one corresponding to a control amount of S (2 g/kg dietary DM), the second to an excess (5 g/kg DM) which is sufficient to trigger cerebrocortical necrosis (CCN) when used in vivo. Acidogenic conditions decreased the pH of the fermenters, CH4 production and cellulose digestibility, increased the short-chain fatty acid production, but had no effect on thiamin production. The high S level enhanced the production of sulfide considerably, had no effect ont he microbial metabolism of energy and N, and decreased thiamin production (326 v. 266 nmol/d). The added thiamin was rapidly converted into phosphorylated compounds which largely decreased the apparent synthesis of this vitamin by the rumen microflora. The total thiamin flow was increased by added thiamin. In no case was thiaminase activity in the fermenter liquid phase significantly modified. The high level of S induced only a limited decrease of total thiamin flow. Consequently, it is unlikely that the investigated factors could be considered to be high risk factors for the thiamin-dependent CCN.

Somatotropin treatment does not affect nonesterified fatty acid response to adrenergic injections in underfed or overfed nonlactating cows.

This experiment was conducted to determine the respective effects of bovine somatotropin (bST) and energy balance on the in vivo responses of plasma nonesterified fatty acids and glucose to isoproterenol (a nonselective beta-agonist) or epinephrine injection in nonlactating nonpregnant cows. Two groups of adult Holstein cows were either underfed (n = 4) at 75%, or overfed (n = 5) at 150% of maintenance energy requirement, respectively. Cows received or did not receive a subcutaneous injection of Sometribove (500 mg) during two experimental periods (cross-over design). Adrenergic or placebo injections (4 nmol/kg body weight of epinephrine or isoproterenol or 4 mL of sterile saline) were administered intravenously on d 7-9 after bovine somatotropin injection, 1 h before 3.5 h after feeding for under- or overfed cows, respectively. Glucose and nonesterified fatty acid responses to each challenge were calculated as area under the response curve and above the base line, from the time of challenge until 60 min postchallenge. Basal plasma nonesterified fatty acids and their response to adrenergic injections were enhanced by underfeeding. Responses of nonesterified fatty acids to isoproterenol injection were higher than they were to epinephrine injection. Basal plasma glucose was enhanced by bovine somatotropin treatment, which increased the glucose response at 5 min after adrenergic injections. Response of plasma glucose was higher after epinephrine than after isoproterenol injection. Treatment with bovine somatotropin did not change plasma nonesterified fatty acid responses to epinephrine or isoproterenol injection in under- or overfed cows, at constant energy intake, whereas underfeeding modified these responses markedly.

Use of a semi-continuous culture system (RUSITEC) to study the effect of pH on microbial metabolism of thiamin (Vitamin B1).

Polioencephalomalacia (P.E.M.) in ruminants is often associated with high concentrate diets and rumen acidosis; this syndrome is classically related to a disturbance of the rumen metabolism of thiamin. An in vitro model using a semicontinuous system (RUSITEC) was used to investigate the effect of pH on microbial metabolism and on production of thiamin in the rumen. These effects were tested using either a natural diet (hay/wheat) or a semi-synthetic one. Lowering the pH decreased total volatile fatty acids, methane and microbial nitrogen production. Molar proportions of VFA were modified by an increase in butyric, valeric and caproic acids. Microbial production of thiamin was comparable to in vivo synthesis but decreased when the diet was enriched with thiamin. The diet of the donors of inoculum had no effect on this metabolism. For all diets, lowering of pH did not reduce microbial production of thiamin. Thiaminase activity in the liquid phase of fermentors was very low and was not modified by pH. Thus lowering of pH in vitro, had no deleterious effect on microbial production of thiamin. Therefore, lowering of the rumen pH in acidotic conditions may not be a factor which promotes P.E.M.

Effect of undernutrition on the ability of the sheep rumen to absorb volatile fatty acids.

The ability of the rumen to absorb the same quantity of VFA with 4 animals previously fed with 2 levels of intake was tested. Animals received maintenance (P1) and half maintenance (P2) energy and nitrogen requirements successively. Absorption was measured with the empty washed rumen technique. Three litres of a solution buffered at pH 6.30 containing VFA (C2:57.1, C3:49.2 and C4:7.4 mM or C2:79.8, C3:23.5 and C4:11.5 mM) and CoEDTA (7.1 mg Co/l) were introduced in the rumen and regularly sampled for 3 h. VFA absorption was linear during the trials. Rates of absorption were expressed as mmol/h or percentage of initial quantity/h for the comparison between VFA. The order of absorption rate (%/h) was C4 > C3 > C2. Water absorption was not significantly different between the periods whereas VFA absorption rates (mmol/h) were significantly reduced after undernutrition. Composition of the solution had no significant effect on VFA absorption rate (%/h).

Effect of kairomones from egg and female adult stages ofOstrinia nubilalis (Hübner) (Lepidoptera, Pyralidae) onTrichogramma brassicae Bezdenko (Hymenoptera, Trichogrammatidae) female kinesis.

Volatile chemicals emanating from the different developmental stages ofOstrinia nubilalis Hübner (Lepidoptera, Pyralidae) increase the mobility ofTrichogramma brassicae Bezdenko (Hymenoptera, Trichogrammatidae) in a linear airflow olfactometer. In this paper, we have demonstrated that airborne chemicals from egg masses and virgin females during calling activity stimulate an intensive search behavior byTrichogramma females. On the other hand, emanations from mated females with extruded abdominal tips do not incite the parasitoid's movement. For the moment we cannot elucidate, with these bioassays, the real role of these kairomones as attractants, guides, stimulants, or retainers.

The influence of physiological state and dietary nitrogen supply on digestion in the dairy cow.

The effects of N supply on digestion were compared in cows in late pregnancy vs early lactation. Two groups of four and one group of three dairy cows received, during a digestion trial, corn silage-concentrate diets (65:35) differing in N supply. Concentrates were formulated so that diets were either insufficient (Diet 1) or sufficient (Diets 2 and 3) in ruminally fermented N and either insufficient (Diets 1 and 2) or sufficient (Diet 3) in protein digestible in the intestines. Experimental periods were 3 wk before and 3 wk after parturition. Organic matter digestibilities were 69.8, 73.1 and 72.5% in late pregnancy vs 64.9, 69.8 and 70.8% in early lactation for Diets 1, 2 and 3, respectively. Digestibility was higher (P less than .05) in late pregnancy than in early lactation. Differences between physiological states were attributed to differences in ruminal digestibility and in fiber digestibility. These differences were not explained by a reduction in large particle retention time, but in situ DM disappearance was reduced in early lactation. Ruminal protozoa concentration and the acetate: propionate ratio decreased between pregnancy and lactation. The duodenal non-ammonia N:N intake ratio was higher for Diet 1 than for Diets 2 and 3, 1.20, .97 and .94, respectively, but it did not vary between physiological states. In conclusion, some of the negative consequences of a shortage in degraded N are more dramatic in early lactation than in late pregnancy.

[A case of very destructive dorsal spondylodiscopathy surgically treated in ankylosing spondylitis complicated by amyloidosis]. / Un cas de spondylodiscopathie dorsale très destructrice et traitée chirurgicalement au cours d'une spondylarthrite ankylosante compliquée d'une amyloïdose.

An ankylosing spondylarthritis was complicated by a D9-D10 spondylo-discopathy, with severe destructive alterations. After strict immobilization for three months, when the lesions partly regressed, non-steroid anti-inflammatory (NSAI) drugs were unable to cause a cure. An excellent result was obtained with a surgical arthrodesis after 5 years. The vertebral location was filed with fibrous tissue. The patient died from an amyloid disease with renal insufficiency. The presence of amyloid tissue in the vertebral location did not prevent a good healing of the vertebral arthrodesis.

[Spinal cord compression in multiple myeloma. Study of 10 cases]. / Les compressions médullaires du myélome. Etude de 10 observations.

Ten cases of multiple myeloma with spinal cord compression are reported. The compression was located in the thoracic spine in 9 cases and in the cervical spine in 1 case. It led to the discovery of the myeloma in 4 cases. Three patients suffered, during several months, from local pain aggravated by activity and from slight and slowly progressive neurologic symptoms resembling intermittent claudication. At the time of diagnosis, sphincter dysfunction was observed only in patients with low thoracic cord compressions. In 4 cases, lesions were first treated by radiotherapy which did not produce regression of the compression. Tumor excision surgery was carried out seven times, once after failure of radiotherapy. In 6 cases an definite and steady regression of the neurological symptoms was achieved. Survival varied from 10 months to 7.5 years after identification of spinal cord compression. Survival was equal to or more than 3 years in 4 patients and will probably reach 3 years in another. Thus spinal cord compression is not by itself a sign indicating a poor short term prognosis in multiple myeloma. It should be treated by excision surgery, then by chemotherapy as in multiple myeloma at other sites.