Unveiling and initial characterization of neural crest-like cells in mesenchymal populations from the human periodontal ligament.

OBJECTIVE: To identify cells with neural crest properties in mesenchymal populations isolated from human periodontal ligament. BACKGROUND: Evidence from tracing experiments on animal embryos revealed proof that dental tissues are among the homing sites of craniofacial neural crest migratory cells. In humans, similar migratory cells were found in early embryos, but whether these cells are progeny of oral multipotent stem cells needs to be confirmed. Searching for the cells with neural crest characteristics in periodontal ligament mesenchymal populations can lead to a solution to the problem. MATERIAL AND METHODS: Populations from the human periodontal ligament were cultured in media supplemented with various concentrations of fetal bovine serum (FBS); assays were performed to evaluate the expression of neural crest, mesenchymal and multipotency genes. RESULTS: In periodontal ligament populations cultured in the standard expansion medium containing minimal amounts of FBS (0.5% or 1%) or lacking FBS, growing numbers of epithelial-like cells emerged, co-expressing neural crest-specific (p75, HNK-1, SOX10), the epithelialization (E-cadherin) and mesenchymal (CD73 and CD105) markers. CONCLUSION: The human periodontal ligament contains a subpopulation of dormant neural crest-like cells, which can be highlighted by culturing at FBS concentrations below 2% or in a serum-free medium.

Human dental pulp stem cells respond to cues from the rat retina and differentiate to express the retinal neuronal marker rhodopsin.

Human adult dental pulp stem cells (DPSCs) are self-renewing stem cells that originate from the neural crest during development and remain within the dental pulp niche through adulthood. Due to their multi-lineage differentiation potential and their relative ease of access they represent an exciting alternative for autologous stem cell-based therapies in neurodegenerative diseases. In animal models, DPSCs transplanted into the brain differentiate into functional neurons or astrocytes in response to local environmental cues that appear to influence the fate of the surviving cells. Here we tested the hypothesis that DPSCs might be able to respond to factors present in the retina enabling the regenerative potential of these cells. We evaluated the response of DPSCs to conditioned media from organotypic explants from control and chemically damaged rat retinas. To evaluate cell differentiation, we analyzed the expression of glial fibrillary acidic protein (GFAP), early neuronal and retinal markers (polysialic acid-neural cell adhesion molecule (PSA-NCAM); Pax6; Ascl1; NeuroD1) and the late photoreceptor marker rhodopsin, by immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR). Exposure of DPSC cultures to conditioned media from control retinas induced a 39% reduction on the number of DPSCs that expressed GFAP; the expression of Pax6, Ascl1, PSA-NCAM or NeuroD1 was undetectable or did not change significantly. Expression of rhodopsin was not detectable in control or after exposure of the cultures with retinal conditioned media. By contrast, 44% of DPSCs exposed to conditioned media from damaged retinas were immunopositive to this protein. This response could not be reproduced when conditioned media from Müller-enriched primary cultures was used. Finally, quantitative RT-PCR was performed to compare the relative expression of glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF), ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in DPSC co-cultured with retinal organotypic explants, where BDNF mRNA expression was significantly upregulated in retinal-exposed cultures. Our data demonstrate that DPSC cultures respond to cues from the rat retina and differentiate to express retinal neuronal markers.

Anti-annexin II antibodies in systemic autoimmune diseases and antiphospholipid syndrome.

OBJECTIVES: The objective of this study were (1) to evaluate the prevalence of anti-annexin II antibodies in patients with various autoimmune diseases and antiphospholipid syndrome and (2) to correlate anti-annexin II antibodies with anti-phospholipid antibodies. MATERIALS AND METHODS: Anti-annexin II antibodies and anti-phospholipid were detected, using an enzyme-linked immunosorbent assay, in the serum of patients with primary antiphospholipid syndrome (n = 16), systemic lupus erythematosus (n = 53), primary Sjögren syndrome (n = 71), systemic sclerosis (n = 17), systemic vasculitis (n = 18), and rheumatoid arthritis (n = 119). Healthy blood donors (n = 99) were used as controls. RESULTS: Anti-annexin II antibodies were significantly more prevalent in patients with connective tissue diseases (8.5%), especially antiphospholipid syndrome (14.8%) and rheumatoid arthritis (10%), than in controls (2%). An inverse correlation was observed between anti-annexin II antibodies and antiphospholipid antibodies. CONCLUSION: Annexin II can be recognized by antibodies in serum from patients with systemic autoimmune disorders. Further studies are required to determine the clinical significance of anti-annexin II antibodies in rheumatoid arthritis and to determine their diagnostic value in discriminating clinical subgroups of patients with antiphospholipid syndrome.

[Incidence of cardiovascular events in giant cell arteritis: preliminary results of a prospective double cohort study (GRACG)]. / Incidence des accidents cardiovasculaires au cours de la maladie de Horton: résultats préliminaires de l'étude prospective en double cohorte GRACG.

UNLABELLED: Giant cell arteritis is the most frequent vasculitis. Cardiovascular events such as cerebrovascular accident or ischemic heart disease may occur in patients with giant cell arteritis. However, their real incidence, as well as their relative risk compared to the general population, remains unknown. PURPOSE: To assess in a prospective, double cohort study, the incidence of cardiovascular events in giant cell arteritis patients compared to controls, after controlling for cardiovascular risk factors. PATIENTS AND METHODS: We included on predefined criteria 432 newly diagnosed patients with giant cell arteritis, each assigned to sex- and age-matched controls randomly selected from the general population. Cardiovascular risk factors (high-blood pressure, diabetes, smoking, hypercholesterolemia and preexisting peripheral vascular disease) were collected at inclusion. During the 24-month follow-up, all cardiovascular events were collected. After stratification for cardiovascular risk factors, a log-rank test was performed to compare cases and controls. A parametric survival model was used for multivariate analysis. RESULTS: Cardiovascular events all combined were significantly increased in patients with giant cell arteritis (RR = 2.15 [1.21-3.81], P = 0.009), and were mainly associated with age (P = 0.0001), past history of cardiovascular disease (P = 0.023) but also with giant cell arteritis (P = 0.009). However, each subset of cerebrovascular accident (RR = 2.42 [0.84-7]) or ischemic heart disease (RR = 1.67 [0.72-3.89]) increased but did not significantly. CONCLUSION: Cardiovascular events incidence is increased in patients with giant cell arteritis, and prescription of preventive antiagregant treatment may be discussed.

Takeover of host ribosomes by divergent IRES elements.

The ribosome is the macromolecular machinery in the host cell for which all viruses have to compete. Early in infection, the viral mRNAs have to compete with the host for both the ribosomes and for the limited pool of eukaryotic initiation factors that are needed to facilitate the recruitment of ribosomes to both viral and cellular mRNAs. To circumvent this competition, certain viruses have evolved to recruit ribosomes to IRESs (internal ribosome entry sites), highly specialized RNA elements that are located at the 5'-end of the viral genomes. Here, we discuss how divergent IRES elements can recruit ribosomes and start protein synthesis with only a minimal set of eukaryotic translation initiation factors, and how this mode of translation initiation aids viral gene amplification during early onset of innate immune responses.

[Aetiological spectrum of hyperferritinemia]. / Spectre étiologique des hyperferritinémies.

UNLABELLED: Serum ferritin levels may be increased in many conditions: renal diseases, liver diseases, human immunodeficiency virus infection. The purpose of this study was to assess the aetiological spectrum of high serum ferritin levels in a 1200-bed university hospital, to compare our results with the data already published and to assess a potential association between aetiology and ferritin levels. PATIENTS AND METHODS: Patients with a serum ferritin level higher than 600 microg/l were retrospectively included between 15 November 2003 and 15 January 2004, and their medical records were reviewed. RESULTS: Ninety-eight patients (38 women and 60 men; median age: 59,5 years [19-92]) were recruited in departments of hepatology and gastroenterology (22%), haematology (14%) and internal medicine (18%). Diagnosis performed were: non-HIV systemic infections (23,8%), haematological diseases (16,1%), alcoholism (11,2%) and malignancies (9,8%). Dialysed chronic renal failure, liver diseases, haemochromatosis and systemic inflammatory diseases counted for 4.2 to 5.2% of cases. Serum ferritin level lied between 600 and 1000 microg/l for 50 patients, between 1000 and 1500 microg/l for 24, and over 1500 microg/l for 24. There was no significant difference between the three groups as regards the etiological distribution. DISCUSSION: In our study, chronic renal failure was not a major cause of high ferritin level: this is probably due to the current use of erythropoietin, which has decreased the use of blood transfusions. The two major aetiology of hyperferritinemia were non-HIV infections and malignancies.

Pulmonary embolism and transitory anti-beta2-GPI antibodies in an adult with chicken pox.

Anti-beta2-glycoprotein I antibodies are considered as a specific marker for the antiphospholipid syndrome. In contrast to lupus circulating anticoagulant and anticardiolipin (aCL) antibodies, they are usually not found at significant levels in infections. We report a case of pulmonary embolism in an adult with varicella. Transient significant levels of aCL antibodies and of IgM anti-beta2-GPI antibodies were observed. No other prothrombotic factor, including free protein S antigen deficiency, was found. The direct pathogenic role of these transient antibodies on the thrombotic event may then be suspected. They are probably associated with VZV acute infection and are absent two months after varicella.

Microscopic polyangiitis: clinical and laboratory findings in eighty-five patients.

OBJECTIVE: To retrospectively analyze the clinical symptoms, laboratory findings, and outcomes in patients with microscopic polyangiitis (MPA) who were enrolled in various clinical trials conducted by the French Vasculitis Study Group. METHODS: A cohort of 85 patients meeting the Chapel Hill criteria for MPA participated in the study. Seventy-one of them were included in prospective therapeutic trials. Eighty-one diagnoses were biopsy proven. In the other patients, diagnosis was based on clinical findings. RESULTS: Forty-seven men and 38 women, with a mean +/- SD age of 56.8 +/- 14.6 years, met the criteria for MPA. Their main clinical symptoms were renal manifestations (78.8%), weight loss (72.9%), skin involvement (62.4%), fever (55.3%), mononeuritis multiplex (57.6%), arthralgias (50.6%), myalgias (48.2%), hypertension (34.1%), lung involvement (24.7%; alveolar hemorrhage 11.8%), and cardiac failure (17.6%). The mean +/- SD serum creatinine level before treatment was 2.59 +/- 2.96 mg/dl; 47 patients had renal insufficiency (serum creatinine > 1.36 mg/dl). Eight patients underwent dialysis at the time of diagnosis, and long-term dialysis was necessary for 10 patients. Antineutrophil cytoplasmic antibodies (ANCA) were present in 38 of 51 patients (74.5%), of whom 33 had a perinuclear staining pattern (pANCA) and 5 had a cytoplasmic pattern. Antibodies to proteinase 3 were present in 4 patients and antibodies to myeloperoxidase were detected in 31, as determined by enzyme-linked immunosorbent assay. Of the 30 patients who underwent renal and celiac angiography, 4 had microaneurysms. Of the 29 patients (34.1%) who had relapses, 8 died during or after the relapse. During followup, 28 of the 85 patients (32.9%) died. The mean +/- SD duration of followup of the group was 69.9 +/- 60.6 months. Deaths were less frequent when patients had been treated with steroids and immunosuppressive drugs (13 patients [24.1%]) than with steroids alone (15 patients [48.4%]) (P < 0.01). The 5-year survival rate was 74%. CONCLUSION: This study demonstrated that MPA is a multisystemic disease in which renal symptoms are frequent, but the disease is also associated with general symptoms, arthritis, mononeuritis multiplex, and other manifestations that are also seen in various vasculitides. The rarity of abnormal angiogram findings and the high frequency of pANCA are characteristic of MPA. In most cases, the outcome is comparable with those of other systemic vasculitides, but relapses are frequent.

[1977 mortality rate in HIV-infected patients presenting with hepatitis C cirrhosis. Results of the GERMIVC multicenter survey conducted in French departments of internal medicine or infectious disease]. / Mortalité par cirrhose virale C chez les patients infectés par le VIH dans les services de médecine interne et de pathologie infectieuse en 1997. Enquête multicentrique GERMIVIC. (Groupe d'étude sur le virus C). (Société nationale française de médecine interne). (Société de pathologie Infectieuse de langue française).

PURPOSE: Hepatitis C (HCV) has a high prevalence (10-30%) among human immunodeficiency virus (HIV)-infected patients. However, little information is available regarding the impact of hepatitis C on survival. The objective of our study was to determine the incidence of hepatitis C-related deaths in HIV-HCV co-infected patients. METHODS: The study was a retrospective (1-year), multicenter cohort survey conducted in 63 departments of either internal medicine or infectious diseases in France. It included 26,497 HIV-infected patients, of whom 4,465 (16.8%) presented coinfection due to the hepatitis C virus. The following parameters were studied for the year 1997: total number of deaths, number of deaths related to either AIDS, cirrhosis, hepatocellular carcinoma, or other causes. RESULTS: Among the 26,497 patients, 543 deaths (incidence: 2%) were observed in 1997; 543 deaths were due to AIDS (incidence: 1.7%), 36 to cirrhosis and/or hepatocellular carcinoma (incidence: 0.13%), and 48 (incidence: 0.18%) to another cause. In the subgroup including 4,465 HIV-HCV-coinfected patients, 29 deaths (incidence: 0.64%) were due to either HCV-related cirrhosis or hepatocellular carcinoma. These results were compared with those of a previous similar survey conducted in 1995, before the era of highly active antiretroviral therapy. The only significant difference is the dramatic regression of deaths due to AIDS. CONCLUSION: The impact of hepatitis C virus on the mortality among HIV-infected patients whose follow-up took place in departments of either internal medicine or infectious diseases in France was very low in 1997. The expected increase in the life span in these patients could modify these results in the future, due to recent improvements in the HIV infection treatment.

Treatment of glomerulonephritis in microscopic polyangiitis and Churg-Strauss syndrome. Indications of plasma exchanges, Meta-analysis of 2 randomized studies on 140 patients, 32 with glomerulonephritis.

UNLABELLED: Although plasma exchanges (PE) have no added benefit in the treatment of vasculitides of the polyarteritis nodosa (PAN) group with steroids (CS) +/- cyclophosphamide (CY), this has not been demonstrated in patients presenting with glomerulonephritis (GN). We therefore reanalyzed the records of microscopic polyangiitis (MPA) or Churg-Strauss syndrome (CSS) patients presenting with GN. PATIENTS AND METHODS: Patients were included consecutively in 2 randomized trials: a) comparing CS vs CS + PE (n = 78) and b) comparing CS + pulse CY +/- PE in PAN and CSS with factors of poor prognosis (n = 62); 9-12 PE/patient were performed. RESULTS: 32 patients, 18 men and 14 women, presented with GN, 28 MPA and 4 CSS, mean age 53.2 +/- 17 years. Clinical/biological manifestations before treatment were comparable in both groups: weight loss 84.4%, fever 62.5%, mononeuritis multiplex 62.5%, purpura 28.1%, GI tract involvement 43.8%, arthritis 37.5%, asthma 12.5%, CNS manifestations 9.4%; cardiac involvement 9.4%; mean creatininemia was 303 +/- 286 mumol/l, proteinuria > 0.5 g/l or 1g/d was found in every case, microscopic hematuria in 20/32 patients, leukocyturia in 12/32. Eight out of/16 were ANCA-positive, ELISA detected anti-MPO antibodies in 5 and anti-PR3 in 3. HBV infection was never observed. After 1 year of treatment, creatininemia decreased from 374.4 +/- 352 to 290 +/- 352 mumol/l in the PE group and from 287 +/- 292 to 170 +/- 67 in the non PE group (NS). Six patients of the PE group and 2 of the non-PE group were dialyzed at onset of treatment. Four of the 6 PE patients and 1 of the 2 not treated with PE were off dialysis 1 year later. In addition 1 patient from the PE group developed a flare with renal failure and required chronic dialysis. The 5-year survival was higher in the PE group (4 deaths/19) than in the non PE group (7/13). The survival curve was 74% in the PE group vs 54% in the non-PE group (NS). CONCLUSION: This study confirms that PE have no added benefit in the treatment of GN in MPA and CSS.