Subclinical enthesopathy of extensor digitorum tendon is highly prevalent and associated with clinical and ultrasound alterations of the adjacent fingernails in patients with psoriatic disease.

BACKGROUND: Nail psoriasis disease is associated with an increased probability of psoriatic arthritis, and its clinical signs may have different correlates with the pathogenesis of adjacent bone destruction and have different prognostic value. Recent publications about psoriasis and nail psoriatic disease describe different ultrasonographic findings but the relationship between these ungueal alterations measured by ultrasonography and the presence of enthesopathy of the extensor digitorum has yet to be discovered. OBJECTIVE: To describe which ultrasonographic characteristics of nail psoriasis are associated with the presence of subclinical enthesopathy in patients with PsO and asymptomatic PsA. METHODS: Patients with psoriasis and asymptomatic psoriatic arthritis were included in the prospective study. Demographic, clinical data and PASI and NAPSI indexes were recorded of all the patients in the assessment visit. The US assessment included Achilles tendon, extensor digitorum tendon and US scan of the nail plate, nail matrix, nail bed and adjacent skin over nail matrix of the five nails of each hand. RESULTS: Forty-eight patients were included in the study; 33 of them presented ultrasound evidence of extensor digitorum tendon enthesopathy. Nails of the patients with subclinical enthesopathy had a higher NAPSI and skin thickness than the nails of the patients without subclinical enthesopathy (P = 0.047). Patients with asymptomatic enthesopathy had significantly thicker proximal nail folds (1.44 ± 0.312 vs. 1.23 ± 0.27, P = 0.023). Nail beds and matrices were also thicker but the differences were not statistically significant (1.77 ± 0.27 vs. 1.74 ± 0.21, P = 0.66, and 1.79 ± 0.28 vs. 1.67 ± 0.19, P = 0.10, respectively). No statistically significant differences in the trilaminar structure were found between both groups. Patients with and without asymptomatic enthesopathy of extensor digitorum tendons did not statistically differ as regards ultrasonographic alterations of the Achilles tendons (60.6% vs. 46.4%, P 0.368). CONCLUSION: Enthesopathy abnormalities can be detected by US in patients with psoriasis without musculoskeletal complaints frequently. There is a close relationship between subclinical enthesopathy of the extensor digitorum tendon and the presence of nail alterations. Further studies are required to research what implications have the presence of these ungual alterations measured by US, and how it affects later development of a PsA.

Genetic study of ICAM1 in clinical malaria in Senegal.

Many genes have been implicated in the risk of severe malaria, generally based on candidate gene studies in case/control populations. Among these genes, there has been conflicting reports for the implication of a variant of the intercellular adhesion molecule 1 (ICAM1), ICAM1(Kilifi), in the risk of severe malaria, while in vitro studies provided independent support for a functional role of this variant. In order to explore the possible implication of ICAM1 in the susceptibility/resistance to malaria and to try to understand its clinical relevance in the disease process, we have conducted linkage and association studies of ICAM1 in two Senegalese villages located in regions of endemic malaria. We explored the full genetic variability of ICAM1, and tested it on several clinical malarial traits which are under genetic control, focusing principally on variables related to the parasite density and the number of malarial attacks. Our study provides no evidence for a role of ICAM1 variability on the malarial phenotypes studied.

Rapid detection of Campylobacter fetus by polymerase chain reaction combined with non-radioactive hybridization using an oligonucleotide covalently bound to microwells.

Campylobacter fetus is recognized as a human and animal pathogen. The isolation and differentiation of C. fetus in diagnostic laboratories is hindered by its relatively slow growth and lack of distinguishing biochemical characteristics. We cloned and sequenced a 1581-bp DNA fragment, IG02, isolated from a C. fetus genomic library. This fragment was used as a probe on DNAs extracted from C. fetus strains and other Campylobacter species: IG02 hybridized only with DNAs from C. fetus strains. A PCR-based test was developed for the detection of C. fetus. A pair of oligonucleotide primers was designed to amplify a 141-bp fragment of IG02. The amplified product was analysed by a non-radioactive sandwich hybridization in microtiter plate using a capture oligonucleotide and a biotin-labelled oligonucleotide for the detection. The combination of PCR and non-radioactive microplate hybridization is a convenient method for the rapid detection of C. fetus.

Cloning of a gene from Mycobacterium tuberculosis coding for a hypothetical 27 kDa protein and its use for the specific PCR identification of these mycobacteria.

PCR targeting the IS 6110 has been considered specific for identification of Mycobacterium tuberculosis and is frequently applied to confirm the presence of this organism directly in biological specimens. However, several authors found that some M. tuberculosis strains failed to hybridize with the IS 6110 probe and other authors found that false-positive results may be obtained for clinical samples when some methods based on IS 6110 are used. In the present study, the p27 gene isolated from a cosmid library was found to be highly specific for M. tuberculosis complex strains and allowed us to develop a PCR-based assay for rapid detection and identification of this mycobacterium. One pair of primers and two oligonucleotide probes were successfully used to amplify and to detect the DNA of strains belonging to the M. tuberculosis complex. These primers and probes did not hybridize with DNA from any of the 21 other mycobacterial species tested. It is worth noting that the chosen primers and probes hybridize with DNA from the M. tuberculosis strain with no IS 6110, furthermore no strain without p27 was found among the 410 strains tested in the present study.

A simple and reliable method for the detection of the 30delG mutation of the CX26 gene.

Mutations in the CX26 gene (GJB2), encoding the gap-junction protein Connexin-26, have been shown to be the major cause of non-syndromic recessive deafness. Among these mutations, the deletion of a guanine within the stretch of six G between nucleotide positions +30 and +35 of the CX26 cDNA (30delG) accounts for the majority of this kind of deafness. Molecular detection of the 30delG mutation is usually performed by direct sequencing analysis of PCR products or by SSCP. To detect this mutation we developed an easy and reliable method, based on PCR, followed by a non-radioactive sandwich hybridization on microtiter plates. We tested 188 individuals recruited from the genetic counseling service for deaf people at the Pasteur Hospital and at the Armand-Trousseau Children's Hospital, Paris, France between April 1997 and September 1998. Our screening method is simple, uses stable and safe reagents, and employs inexpensive equipment. As such, it is suitable for widespread use in genetic diagnosis.

Cloning of a sapB homologue (sapB2) encoding a putative 112-kDa Campylobacter fetus S-layer protein and its use for identification and molecular genotyping.

A sap gene encoding a surface layer protein was isolated from a Campylobacter fetus ssp. fetus CIP 53.96T cosmid library. This sap gene, which shows significant homology with the sapB conserved region, was named sapB2. The complete ORF of 3339 nucleotides encodes a 1112-amino acid polypeptide with a calculated molecular mass of 112 kDa. High homology with the sapB gene was found in a region beginning 67 bp before the ORF and proceeding 546 bp into the ORF. Similarly, 98% homology with the sapA2 gene was observed in a 2038-bp region beginning 540 bp after the initiation codon. In the present study, we show that this sapB2 gene has two main interesting features: the 5' end of the region which presents high homology with the sapA2 homologue was found to be present in every C. fetus strain, and the fragment (IG01) comprising the region which presents homology with the sapB conserved region and the 5' end of the sapA2 homologue region, when used as a probe, can reveal genomic polymorphism among C. fetus strains. We exploited these features to develop a PCR assay for the specific detection of C. fetus and to set up a method for typing C. fetus isolates. The PCR assay was found to be species-specific. Oligonucleotide primers derived from the 5' end of sapA2 homologue region were used in a polymerase chain reaction test on genomic DNA extracted from 101 Campylobacter fetus, 18 Campylobacter non-fetus and seven non-Campylobacter strains. A 220-bp fragment was amplified only when C. fetus DNA was used as a target. In Southern blot analysis, the IG01 probe was found to hybridize only with DNA extracted from C. fetus strains. Moreover, IG01 hybridized with several fragments of HindIII-digested DNA, giving a specific pattern for each strain.