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.

[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.

Twelve cases of pituitary apoplexy.

In 12 cases of pituitary apoplexy, a preexisting unsuspected adenoma was found. The initial manifestations were sudden onset of headache (12 patients), signs of meningeal irritation (10) with fever (four), altered consciousness (12), and ophthalmologic disturbances (eight). The diagnosis was retrospective in three cases. Radiologic investigations were always suggestive if carefully considered. The plain skull roentgenograms, in particular, showed an enlarged sella turcica in 11 cases. Three patients had prolactin adenomas, and nine had nonfunctional adenomas. Medical treatment was successful in only three patients; surgery was performed in 10 cases by means of a sublabial transseptal microsurgical approach. Postoperative neurologic complications were serious in two cases. Endocrine insufficiencies were common: eight cases of permanent panhypopituitarism, two cases of pluritropic anterior pituitary dysfunction, and three cases of persistent hyperprolactinemia.

[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.

[Primitive Sjögren's syndrome in France and Ecuador. Possible involvement od HTLV 1]. / Syndrome de Sjögren primitif en France et en Equateur. Possible implication de l'HTLV1.

The authors study the possible involvement of retrovirus in Sjögren's syndrome. They report a preliminary study of 20 French and 13 Ecuadorian patients with a primary Sjögren syndrome. A previous epidemiologic study showed a HTLV1 seroprevalence going from 0.04 to 6% on different regions of Ecuador. The results of this study show the presence of anti-HTLV1 antibodies only in 2 Ecuadorian patients and does not allow a final conclusion of the role of HTLV1 virus. Nevertheless other studies continue on the serie using minor salivary gland specimens obtained by biopsy. Recent publications and the notion of an "endogen" retrovirus will may be lighten a new day in this research.

[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.

[Streptococcus pneumoniae bacteremia and HIV infection. Retrospective study of 41 episodes in 30 patients]. / Bactérièmies à Streptococcus pneumoniae et infection par le VIH. Etude rétrospective de 41 épisodes chez 30 malades.

OBJECTIVES: Pulmonary infections and bacteraemia, essentially due to Streptococcus pneumoniae and Haemophilus influenzae, are frequently reported in patients infected with the human immunodeficiency virus (HIV). We retrospectively analyzed episodes of bacteraemia in HIV-infected patients to determine whether supplementary risk factors could be ascertained and whether it would be advisable to propose vaccination. METHODS: From June 1986 to February 1992, 41 episodes of bacteraemia in 30 HIV-infected patients were observed in 7 different wards. Data on age, sex, risk group, Centers for Disease Control classification, CD4 counts and clinical outcome were recorded. RESULTS: There were 18 males and 12 females, mean age 34 years (range 26-67 years) in CDC class II (n = 11), III (n = 5) and IV (n = 16). There were 17 intravenous drug users (56.6%). There were 8 heterosexuals (26%), 3 homosexuals or bisexuals (n = 3) and 2 patients infected after blood transfusions (6%). All the heterosexual patients were of black-African or Carabean ethnic origin. Mean CD4 count was 239 mm3 (range 2-1148) during the episode of bacteraemia which occurred during an upper respiratory tract infection in 96% of the patients. Recurrent episodes were observed in 7 patients. Outcome of the infectious episode was favourable in 35/41 cases after antibiotic therapy. Six patients (all CDC class IV) died during the episode of bacteraemia. CONCLUSIONS: These observations showed that intravenous drug use and black-African ethnic origin are supplementary risk factors for S. pneumoniae infection in HIV-infected patients. The frequency of upper respiratory tract infections in these patients suggests that anti-S. pneumoniae vaccination should be evaluated further.

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.