Réexamen du contexte géologique,chrono- et biostratigraphique du site de Moulin Quignon à Abbeville (Vallée de la Somme,France)

The geological context of the discoveries made by Boucher de Perthes at Moulin Quignon in 1863–1864 was examined through the testimonies left by himself, by his detractors, then by geologists and archaeologists who later worked on the alluvial deposits of the Somme at Abbeville. This critical approach has been completed by specific studies, through a restricted excavation performed at Carpentier Quarrya locality known since the end of the 19th century as a sequence analogous to Moulin Quignon, and by a series of new analyses (microvertebrate, malacofauna, dating). The main results of these studies confirm the fluvial nature of the ‘archaeological’ layers at Moulin Quignon that correspond to a high terrace of the Somme River, about 40 m above the current valley incision at Abbeville. Dating results provide an age of 584 ± 48 ka for the fluvial levels at Carpentier Quarry, in good agreement with the available biostratigraphic data, inferred from malacofaunas collected at both Moulin Quignon (Boucher de Perthes collection) and Carpentier Quarry, and from mammals fauna recovered since the end of the 19th century from the white marl at Carpentier Quarry which allow the allocation of these alluvial deposits to an interglacial stage of the second half of the Cromerian, the marine isotopic stage (MIS) 15. From these data and taking into account the identification of the human remains of Moulin Quignon as an anatomically modern man, the contemporaneity of these remains with the alluvial deposits of a high terrace of the Somme River is virtually impossible and supports the hypothesis of a hoax. Besides, it is possible that at least some of the lithic material collected at the time of the discovery by Boucher de Perthes could derive from fluvial levels dated of approximately 600,000 years. They would be then the oldest evidence of a human presence in the Somme Valley.     

The phenotype and genotype of rheumatoid arthritis in the Democratic Republic of Congo

Introduction

Little is known about rheumatoid arthritis in the black, particularly in Congolese, populations. Our objective was to describe the phenotype and genotype of rheumatoid arthritis (RA) in Congolese.

Methods

All consecutive rheumatoid arthritis (RA) patients attending Kinshasa University Hospital in a three-year time period were included. Demographics, clinical features and tobacco consumption were noted. Disease Activity Score (DAS)-28 based on the erythrocyte sedimentation rate (ESR), Health Assessment Questionnaire (HAQ), anti-citrullinated peptide antibodies (CCP) antibodies and rheumatoid factor (RF) were determined. Radiographs were scored according to Sharp-van der Heijde. On a subset of patients and controls HLA-DRB1 typing was performed.

Results

A total of 114 females and 14 males aged 51.2 ± 14.9 were included. Mean duration of symptoms was four years. Moderate tobacco consumption was reported in a minority of patients. DAS-28 at first visit was >5.1 and HAQ ≥0.5 in all patients. X-rays showed joint erosions and/or joint space narrowing, mostly of a moderate grade in 55.8% of patients. Anti-CCP and/or RF were present in 48.6% of patients with available data (n = 72) and in 3.0% of controls (n = 67). Radiographic changes and nodules were more frequent in RF or anti-CCP positive patients. One copy of the shared epitope was found in 13 patients (35.1%) and 3 controls (12.5%). Two copies were found in one patient (2.7%) and in one control (4.2%).

Conclusion

Congolese patients with RA consult long after disease onset. Despite this delay, the majority presents without major damage and is RF, anti-CCP and SE negative. We put forward the hypothesis that besides different environmental factors there is probably also a particular genetic risk profile in Congolese patients, different from the HLA-DRB1 shared epitope.     

Glycosylation sites and site-specific glycosylation in human Tamm- Horsfall glycoprotein

The N-glycosylation sites of human Tamm-Horsfall glycoprotein from one healthy male donor have been characterized, based on an approach using endoproteinase Glu-C (V-8 protease, Staphylococcus aureus ) digestion and a combination of chromatographic techniques, automated Edman sequencing, and fast atom bombardment mass spectrometry. Seven out of the eight potential N-glycosylation sites, namely, Asn52, Asn56, Asn208, Asn251, Asn298, Asn372, and Asn489, turned out to be glycosylated, and the potential glycosylation site at Asn14, being close to the N-terminus, is not used. The carbohydrate microheterogeneity on three of the glycosylation sites was studied in more detail by high-pH anion-exchange chromatographic profiling and 500 MHz1H-NMR spectroscopy. Glycosylation site Asn489 contains mainly di- and tri-charged oligosaccharides which comprise, among others, the GalNAc4 S (beta1-4)GlcNAc terminal sequence. Only glycosylation site Asn251 bears oligomannose-type carbohydrate chains ranging from Man5GlcNAc2to Man8GlcNAc2, in addition to a small amount of complex- type structures. Profiling of the carbohydrate moieties of Asn208 indicates a large heterogeneity, similar to that established for native human Tamm-Horsfall glycoprotein, namely, multiply charged complex-type carbohydrate structures, terminated by sulfate groups, sialic acid residues, and/or the Sda-determinant.