Manifold aspects of specificity in a nematode-bacterium mutualism.

Coevolution in mutualistic symbiosis can yield, because the interacting partners share common interests, to coadaptation: hosts perform better when associated with symbionts of their own locality than with others coming from more distant places. However, as the two partners of a symbiosis might also experience conflicts over part of their life cycle, coadaptation might not occur for all life-history traits. We investigated this issue in symbiotic systems where nematodes (Steinernema) and bacteria (Xenorhabdus) reproduce in insects they have both contributed to kill. Newborn infective juveniles (IJs) that carry bacteria in their intestine then disperse from the insect cadaver in search of a new host to infect. We ran experiments where nematodes coinfect insects with bacteria that differ from their native symbiont. In both Steinernema carpocapsae/Xenorhabdus nematophila and Steinernema feltiae/Xenorhabdus bovienii symbioses, we detected an overall specificity which favours the hypothesis of a fine-tuned co-adaptation process. However, we also found that the life-history traits involved in specificity strongly differ between the two model systems: when associated with strains that differ too much from their native symbionts, S. carpocapsae has low parasitic success, whereas S. feltiae has low survival in dispersal stage.

On the origin of the invasive olives (Olea europaea L., Oleaceae).

The olive tree (Olea europaea) has successfully invaded several regions in Australia and Pacific islands. Two olive subspecies (subspp. europaea and cuspidata) were first introduced in these areas during the nineteenth century. In the present study, we determine the origin of invasive olives and investigate the importance of historical effects on the genetic diversity of populations. Four invasive populations from Australia and Hawaii were characterized using eight nuclear DNA microsatellites, plastid DNA markers as well as ITS-1 sequences. Based on these data, their genetic similarity with native populations was investigated, and it was determined that East Australian and Hawaiian populations (subsp. cuspidata) have originated from southern Africa while South Australian populations (subsp. europaea) have mostly derived from western or central Mediterranean cultivars. Invasive populations of subsp. cuspidata showed significant loss of genetic diversity in comparison to a putative source population, and a recent bottleneck was evidenced in Hawaii. Conversely, invasive populations of subsp. europaea did not display significant loss of genetic diversity in comparison to a native Mediterranean population. Different histories of invasion were inferred for these two taxa with multiple cultivars introduced restoring gene diversity for europaea and a single successful founder event and sequential introductions to East Australia and then Hawaii for cuspidata. Furthermore, one hybrid (cuspidata x europaea) was identified in East Australia. The importance of hybridizations in the future evolution of the olive invasiveness remains to be investigated.

[Bronchial presentation of stage IVB Hodgkins disease]. / Localisation bronchique révélatrice d'une maladie de Hodgkin.

INTRODUCTION: Bronchial localisation of Hodgkins disease has been described only rarely and it is exceptional as the presenting feature. More frequently the clinical presentation is extrinsic bronchial compression. OBSERVATION: Mr B.C., 34 years old, had a past history of cured alcoholism and abuse of cannabis and buprenorphine. In February 2001 he presented with generalised pruritus, weight loss of 8 kg in one year, a 1 cm node above the right clavicle, hypereosinophilia, and CT evidence of non-obstructive mediastinal adenopathy and interstitial lesions in the right lower lobe. Five months later he was admitted to hospital with a febrile illness. The right supraclavicular node had disappeared but there was gross mediastinal adenopathy, associated with a right perihilar soft tIssue mass encircling the upper, middle and lower lobe bronchi and multiple peripheral parenchymal nodules. Bronchoscopy revealed complete stenosis of the right upper lobe bronchus and bronchial histology confirmed Hodgkins disease. CONCLUSIONS: Bronchoscopy is an effective investigation for the detection of endobronchial Hodgkins disease, often overlooked because parenchymal abnormalities are attributed to extrinsic compression. In order to determine the disease stage more precisely we advise immediate bronchoscopy when there is suspicion that Hodgkins disease may be the cause of clinical.

A integracao escolar de criancas deficientes mentais: estudo historico e questoes atuais

Os autores tecem, em primeiro lugar, uma historia da integracao escolar de criancas deficientes mentais na Franca. Em seguida, discutem algumas questoes atuais. Concluem que os processos nesse dominio so serao possiveis se acompanhados por uma situacao terapeutica fundada na transferencia.

Enzyme-linked oligosorbent assay for detection of polymerase chain reaction-amplified human immunodeficiency virus type 1.

An enzyme-linked oligosorbent assay (ELOSA) was developed for the detection on microtiter plates of polymerase chain reaction (PCR)-amplified human immunodeficiency virus type 1 (HIV-1) DNA. The denatured PCR product was hybridized with a passively adsorbed oligonucleotide capture probe and a horseradish peroxidase-labeled oligonucleotide detection probe. The sensitivity and specificity of the PCR-ELOSA technique depended to some extent on the nucleotide sequences of the oligonucleotide primer and probe quartet used in the amplification and detection. We evaluated five oligonucleotide quartets located in the gag, pol, vpr, env, and nef regions of HIV-1. DNAs from 39 HIV-1-seropositive individuals and 27 healthy HIV-1-seronegative controls were amplified by the PCR procedure, and the products were detected by ELOSA. Ten copies of HIV-1 DNA against a background of 1 microgram of human DNA were specifically detected by PCR-ELOSA. Specificities and sensitivities were, respectively, 100 and 95% for the gag system, 100 and 97% for the pol system, 100 and 85% for the vpr system, 96 and 95% for the env system, and 100 and 95% for the nef system. The simplicity of ELOSA makes it suitable for automation and applicable to genetic testing and detection of viral and bacterial DNAs or RNAs in most routine laboratories.

[Kidney transplantation in hyperimmunized patients ignoring the cross-match performed with historic sera]. / Transplantation rénale chez des malades hyperimmunisés en ignorant le cross-match réalisé avec les sérums historiques.

To ignore the positivity of renal pretransplantation cross-match performed with peak sera remains a controversial practice. The present study concerns 11 renal transplantations after positive cross-match with peak sera and negative cross-match with current sera. The clinical results of these transplantations lead to the assumption that peak sera contained HLA antibodies not specific to the graft and non HLA antibodies responsible for the positivity of the cross-match.

[Drash syndrome]. / Syndrome de Drash.

The authors report one case of Drash syndrome: association of Wilms' tumor, nephropathy and genital abnormalities. The definition, prognosis and origin of this triad are discussed.

[Immunologic diagnosis of rheumatoid polyarthritis using a new micromethod of quantitative hemagglutination of the rheumatoid factor: the polyartiter]. / Diagnostic immunologique de la polyarthrite rhumatoïde a l'aide d'une nouvelle microméthode d'hémagglutination quantitative du facteur rhumatoïde: le polyartitre.

A new micromethod of quantitative haemagglutination of the rheumatoid factor (class IgM) "polyartitre" was studied and compared with the classical Waaler-Rose reaction to the polyartest and to the rheumalatex using sera from 40 patients with rheumatoid arthritis, confirmed both radiologically and clinically. Thirty controls were selected from among the blood donors and 29 subjects with viral infections, hepatic or systematic illnesses or metabolic troubles. This method presents an excellent concordance with other methods. It is quantitatively more sensitive as the rheumatoid factor titres are higher than those obtained with the classical Waaler-Rose reaction. The polyartitre is simple to perform, easy to read, specific and reproducible, and the results are expressed in international units.