Association of Fcγ receptor IIIA variant with a subset of anti-topoisomerase I-positive patients in systemic sclerosis: a descriptive pilot study.

Hypothesizing a pathophysiological role of anti-topoisomerase I antibodies (anti-topo I) through autoantibody-dependent cell-mediated cytotoxicity (ADCC) and cytotoxic effectors expressing receptors for the Fc portion of IgG in systemic sclerosis (SSc), 267 SSc patients (56 with anti-topo I and 102 with anti-centromere antibodies (ACA)) were genotyped for the functional FCGR3A-V158F polymorphism. A descriptive analysis of patients according to their clinical and immunological status and FCGR3A-158 V/F genotypes was performed using multiple correspondence analysis. This descriptive analysis revealed an association between the FCGR3A-158 VV genotype and the presence of anti-topo I. By contrast, no relationship was found between FCGR3A polymorphism and the presence of ACA. SSc patients with anti-topo I appear to be more frequently homozygous for the high-affinity FcγRIIIA-coding allele, suggesting that some autoantibodies may be pathogenic through ADCC.

First assessment of sophrology for the treatment of subjective tinnitus.

OBJECTIVES: To assess (without comparison versus controls) the efficacy of a sophrology protocol adapted to disabling subjective tinnitus, in diminishing the handicap induced by perception of tinnitus. MATERIALS AND METHODS: One hundred and forty consecutive patients, aged 18-83 years, underwent a protocol comprising 6-8 sessions of sophrology over a 2-4 month period. Impact was assessed on pre- to post-treatment progression on the Tinnitus Handicap Inventory (THI), a validated questionnaire measuring handicap induced by tinnitus. RESULTS: Mean THI scores improved, by >20 points in 59.2% of cases (i.e., clinically significant decrease). Improvement was independent of tinnitus duration (>versus<6 months) and origin (acoustic trauma versus emotional shock), and concerned all 3 THI subscales (functional, catastrophic and emotional). CONCLUSION: The present sophrology protocol, dedicated to subjective tinnitus, reduced intrusiveness. Further studies with a control group are needed to confirm efficacy as compared to waiting list or other validated treatments such as cognitive behavioral therapies.

Neutrophil role in in vivo anti-lymphoma activity of rituximab: FCGR3B-NA1/NA2 polymorphism does not influence response and survival after rituximab treatment.

BACKGROUND: Neutrophils could play an important role in in vivo rituximab anti-lymphoma activity. FcgammaRIIIb is expressed only by neutrophils and FcgammaRIIIb-neutrophil antigen (NA)1/NA2 polymorphism influenced phagocytosis of immunoglobulin G1-opsonized particles. We formulated the hypothesis that if neutrophils are critical cells for in vivo rituximab activity, FcgammaRIIIb-NA1/NA2 polymorphism could influence the response to rituximab. PATIENTS AND METHODS: FCGR3B-NA1/NA2 genotypes were determined in 46 patients having received rituximab for a previously untreated, follicular, non-Hodgkin's lymphoma. The clinical response and the disappearance of the BCL2-JH gene rearrangement in both peripheral blood and bone marrow were evaluated at 2 months (M2) and each year during 7 years. RESULTS: They were 13% homozygous for FCGR3B-NA1, 61% homozygous for FCGR3B-NA1/NA2 and 26% heterozygous. The objective response rates at M2 were 67% in homozygous FCGR3B-NA1 patients compared with 75% in homozygous FCGR3B-NA2 and 75% in heterozygous patients (not significant). We found no difference for progression-free and overall survival by FCGR3B-NA1/NA2 genotypes. CONCLUSION: These results indicate no association between FCGR3B-NA1/NA2 polymorphism and response to rituximab indicating no significant role of phagocytosis mediated by neutrophils in in vivo mechanism of rituximab activity.

Matrix Gla protein in Xenopus laevis: molecular cloning, tissue distribution, and evolutionary considerations.

Matrix Gla protein (MGP) belongs to the family of vitamin K-dependent, Gla-containing proteins and in higher vertebrates, is found in the extracellular matrix of mineralized tissues and soft tissues. MGP synthesis is highly regulated at the transcription and posttranscription levels and is now known to be involved in the regulation of extracellular matrix calcification and maintenance of cartilage and soft tissue integrity during growth and development. However, its mode of action at the molecular level remains unknown. Because there is a large degree of conservation between amino acid sequences of shark and human MGP, the function of MGP probably has been conserved throughout evolution. Given the complexity of the mammalian system, the study of MGP in a lower vertebrate might be advantageous to relate the onset of MGP expression with specific events during development. Toward this goal, MGP was purified from Xenopus long bones and its N-terminal amino acid sequence was determined and used to clone the Xenopus MGP complementary DNA (cDNA) by a mixture of reverse-transcription (RT)- and 5'- rapid amplification of cDNA ends (RACE)-polymerase chain reaction (PCR). MGP messenger RNA (mRNA) was present in all tissues analyzed although predominantly expressed in Xenopus bone and heart and its presence was detected early in development at the onset of chondrocranium development and long before the appearance of the first calcified structures and metamorphosis. These results show that in this system, as in mammals, MGP may be required to delay or prevent mineralization of cartilage and soft tissues during the early stages of development and indicate that Xenopus is an adequate model organism to further study MGP function during growth and development.

Sequence analysis and transcriptional mapping of the orf-2 gene of Autographa californica nuclear polyhedrosis virus.

Sequencing of the dnapol promoter region of Autographa californica nuclear polyhedrosis virus (AcNPV) revealed an overlapping open reading frame (ORF) in an antisense orientation, referred to as ORF-2. Analysis of the ORF-2 deduced amino-acid sequence revealed two short regions of homology with a similar ORF from Lymantria dispar nuclear polyhedrosis virus (LdNPV). Two 3' processing signals of this gene, expressed late during infection, were shown to be located on the orf-2 stop codon and 162 nucleotides further downstream.

Cloning of the bone Gla protein gene from the teleost fish Sparus aurata. Evidence for overall conservation in gene organization and bone-specific expression from fish to man.

Bone Gla protein (BGP, Osteocalcin) is a bone-specific vitamin K-dependent protein which has been intensively studied in mammals. Although BGP is the most abundant non-collagenous protein of bone, its mode of action at the molecular level remains unclear. From an evolutionary point of view, the appearance of BGP seems to parallel the appearance of hydroxyapatite-containing bone structures since it has never been found in elasmobranchs, whose skeleton is composed of calcified cartilage. Accordingly, recent work indicates that, in mammalian bone, BGP is required for adequate maturation of the hydroxyapatite crystal. Taken together, these data suggest that teleost fishes, presumably the first vertebrates to develop a BGP-containing skeleton, may be a useful model to further investigate BGP function. In addition, fish offer several advantages over mammalian models, due to a large progeny, external embryonic development and transparency of larvae. In the present work, the BGP cDNA and gene were cloned from a teleost fish, Sparus aurata, and its tissue distribution, pattern of developmental expression and evolutionary pathways analyzed. The molecular organization of the Sparus BGP (spBGP) gene is similar to mammalian BGP genes, and its expression throughout development follows the onset of calcification. The spBGP gene encodes a pre-propeptide of 97 amino acid residues, expressed only in bone and showing extensive homology to its mammalian homologs. Phylogenetic analysis of the available BGP sequences supports the hypothesis that all BGPs have a single origin and share a common ancestor with a related vitamin K-dependent protein (Matrix Gla protein).

Maturational and degenerative processes in the organ of Corti after neonatal hypothyroidism.

In order to study the long-term effects of neonatal hypothyroidism on the organ of Corti, rats were given propylthiouracil (PTU) during the first 30 days after birth. Cochlear changes occurring after the cessation of antithyroid treatment were studied by both physiological (brainstem auditory evoked responses: BAERs, electrocochleography) and morphological techniques (transmission and scanning electron microscopy). The first appearance of BAERs was noted between days 37 and 45. Maturation of auditory potentials was achieved within 10-15 days but was incomplete since the animals definitely demonstrated elevated thresholds around 60-70 dB SPL. Morphological results indicated that some structures, like the inner sulcus epithelium, were able to restart maturational processes that had been interrupted during the period of hypothyroidism. However, these maturational changes were considerably limited and rapidLy accompanied by severe degenerative changes involving almost all cochlear structures. Degenerative changes included the deposition of an amorphous substance within the organ of Corti, severe alterations in pillar cells (absence of formation of the tunnel of Corti, distortion of microtubules), severe outer hair cell losses with abnormalities in their innervation (absence of development of efferents and loss of afferent dendrites).

Effects of hypothyroidism on the structural development of the organ of Corti in the rat.

The structural development of the organ of Corti was studied in 30 rat pups rendered hypothyroid by daily administration of propylthiouracil during the first 35 days after birth. Cochlear changes were observed by light microscopy and electronmicroscopy. Hypothyroid rat pups were found to have severe abnormalities in the organ of Corti. There was an abnormally prolonged persistence of Kölliker's organ and striking distortion of the tectorial membrane. The sensory epithelium exhibited marked signs of immaturity: the tunnel of Corti has not opened yet in animals 35 days old, sensory and supporting cells presented immature characteristics with abnormal persistence of the kinocilium. It is suggested that hypothyroidism results in an overall retardation of the maturation of cochlear structures and ultrastructural changes that appear to be significant enough to account for the hearing loss.

[Posturography should be included in the vertigo test]. / La posturographie doit être incluse dans l'examen du vertigineux.

After a brief review of different systems involved in postural control, we describe a method of posturography for exploring vestibulospinal pathways, in which postural oscillations of subject standing on a platform are recorded with eyes open then with eyes closed, and in different head and gaze positions. In normals, only closing of eyes interferes significantly with balance. Posturography is important in vertigo examinations, because it can show: vestibuloocular and vestibulospinal pathway lesions, associated or not; whether there is compensation for imbalance by visual input; cervical origin of vertigo, if any; and, in acute vestibular deficit, that good test results suggest a favorable prognosis.

[Neurinomas with normal brain stem auditory evoked potentials]. / Les neurinomes à BERA normaux.

Of 145 neurinomas operated upon, 2% had normal brain stem auditory evoked potentials (BERA). Potentials were obtained by means of a special technique allowing extraction every 600 ms and its follow up with time (brain stem temporal dynamic). This score of 2% was also that reported by some American authors who associate electrocochleography with BERA. The latter provide an accurate diagnosis in 96% of cases of all types of tumors taken together and in 91% of cases of small tumors. Furthermore, the performance of conventional scan imaging is accurate in only 25% of small tumors whereas gas meatocysternography detects more than 95% of cases. The latter method is therefore the most sensitive one but it possesses the disadvantage of being invasive and of costing much more than BERA, which remains therefore the least invasive examination providing the best and earliest diagnosis.

[Implications of receptors for the Fc portion of IgG (FcgammaRs) in mechanism of action of therapeutic antibodies]. / Rôle des récepteurs à la portion Fc des IgG (FcgammaRs) dans l'activité des anticorps thérapeutiques.

From several years ago, recombinant monoclonal antibodies have allowed a revolution in therapeutic approach of cancer patients. Whereas the clinical efficacy of many antibodies is now demonstrated, their mechanism of action in patients remains elusive. For antibodies targeting membrane antigens, they particularly resort to cytotoxic effectors, which expressed receptors for Fc portion of IgG (FcgammaRs). This review analyses different functions depending of FcgammaR and their potential role in mechanism of action of therapeutic antibodies. A better knowledge of these functions should allow in the next future the optimisation of these treatments.

Intron-length polymorphism at the actin gene locus mac-1: a genetic marker for population studies in the marine mussels Mytilus galloprovincialis Lmk. and M. edulis L.

A novel intron-length polymorphism at the actin gene locus mac-1 is here reported and used as a genetic marker for population studies in mussels of the genus Mytilus. Two closely related genes subsequently identified as alleles, mac-1a1 and mac-1b1, from a genomic library of M. galloprovincialis were partially cloned and sequenced. They mainly differed from each other by a 65-bp insertion within their first intron. Polymerase chain reaction (PCR) primers were designed outside the insertion. The PCR analysis of 166 individual mussels from M. galloprovincialis and M. edulis populations revealed three size-classes of alleles or allelomorphs, two of which were of the expected sizes for mac1a1 and mac-1b1. One allelomorph was absent from M. edulis samples, although it was present at substantial frequencies in M. galloprovincialis populations. The frequencies of the two other allelomorphs significantly differed between M. galloprovincialis and M. edulis populations. The comparison of six mac-1 intron sequences over 277 bp showed at once that allelomorphs encompassed alleles differing from one another by substantial numbers of mutations, and that identical alleles were present in both M. galloprovincialis and M. edulis individuals, a probable result of the recent introgression between the two species.

Temporal regulation of a complex and unconventional promoter by viral products.

The DNA polymerase (dnapol) gene of Autographa californica nuclear polyhedrosis virus presents a complex promoter organization. It lacks the usual TATA box and start site, and its RNA accumulation initially increases and then decreases dramatically during infection. We investigated dnapol temporal regulation. Transiently expressed dnapol gene was transcribed at a low level from minor start sites. Coexpression with ie0 and/or ie1 immediate-early genes dramatically enhanced dnapol transcription, specifically from a new start site. Moreover, the ie1 transactivation required little or no information in front of this nonconventional proximal promoter. We showed that IE0 and IE1 proteins were stably expressed during infection and that the dnapol mRNA level decrease was not a consequence of the disappearance of these proteins. The dnapol promoter region contains a putative overlapping open reading frame (ORF) in the opposite direction. We showed that ORF-2 was indeed highly expressed late, when the dnapol mRNA level decreased, and that during that time, dnapol mRNA stability was not significantly altered, excluding a destabilizing antisense effect. Additionally, we showed that the dnapol promoter was inhibited late but not early during the infection of cells transiently expressing constructs carrying either the intact or the altered ORF-2 promoter. Therefore, ORF-2 initiation of transcription and dnapol promoter inhibition are two coincidental nonrelated phenomena. Finally, we showed that both IE1 transactivation and late inhibition occurred in the same limited region around the dnapol promoter.

Expression of the arylsulphatase reporter gene under the control of the nit1 promoter in Chlamydomonas reinhardtii.

In Chlamydomonas reinhardtii, the expression of the nit1 gene encoding nitrate reductase is dependent on the nature of the nitrogen source and on other environmental factors. We have fused the nit1 promoter region to the arylsulphatase (ars) reporter gene lacking its own promoter and introduced this chimeric construction (nit1/ars) into a wall-less strain of C. reinhardtii. A new and sensitive method, based on the use of alpha-naphthylsulphate as a substrate and a diazonium salt as a chromogenic post-coupling agent, was developed to detect the activity of arylsulphatase (an enzyme which is almost completely secreted in the culture medium) both in vitro and in agar plates. The transformants carrying nit1/ars did not express arylsulphatase when grown in ammonium-sufficient medium but readily accumulated the enzyme in ammonium-free medium either supplemented, or not supplemented, with nitrate or nitrite. The nit1/ars construct, however, was not expressed in the nit2 mutant lacking a specific transcription regulator controlling the expression of nit1. These results, together with the observation that the transcription of nit1/ars is initiated at the same sites as the nit1 endogenous gene, confirms the hypothesis that the regulation of nit1 expression takes place mainly at the transcriptional level. The expression of the ars gene from the nit1 promoter was high enough to allow direct measurements of arylsulphatase activities in pools of transformants without prior isolation of nit1/ars clones. This original procedure has permitted the analysis of the effects of nested deletions in the nit1 promoter region on the expression of the reporter gene. The results indicate that the -282 to -198 sequence is required for transcription to occur and that the -751 to -282 region contains several elements mediating nit1 expression.

Computer-assisted ABR interpretation using the automatic construction of the latency-intensity curve.

In this paper, we present a new computerised technique for the automatic construction of the latency intensity curve (LI curve). We take a pattern recognition approach determined by a priori information. We use knowledge gained from the audiogram and from physiological considerations. Therefore, we consider all recordings at different intensities as well as results from the extraction of a single auditory brainstem response (ABR) at a given stimulus intensity. We tested our method successfully: it allows us to prevent misrecognition errors in response detection or in latency measurements. Automatic recognition of the waves and recognition by the ear, nose and throat (ENT) specialist coincided in at least 90 per cent of cases. For wave V, the average deviation between the response thresholds given by our automatic recognition algorithm and those given by the ENT specialist was 5 dB, and the average deviation of the latencies was 0.05 ms.

[Human Scarpa ganglion cell sheath]. / Sur la gaine des cellules ganglionnaires de Scarpa chez l'homme

The ganglion vestibulare (Scarpa) has been studied with the electron microscope on thirteen operative specimens (neurectomy for Meniere's vertigo) and two random autopsy specimens. Neuroganglionar cell bodies are enclosed in a Schwann sheath, without any myelin. This observation is at variance with previous descriptions in various vertebrate forms.