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N Dourov

Publications and source records attributed to N Dourov.

124 records · Page 7Linked to original sources
PubMedDate not supplied

Correlation of HSP110 expression with all-trans retinoic acid-induced apoptosis.

In a previous study, we observed the strong expression of a stress protein of the HSP100/Clp family (HSP110) in apoptotic mesectodermal cells during early mouse facial development. In the present study, we describe the strong expression of the same HSP110 in mesectodermal cells undergoing apoptosis after all-trans retinoic acid (RA) administration. We used a teratological model known to increase cell deaths mainly in the first and second branchial arches during mammalian cephalogenesis: the treatment of E9 mouse embryos with all-trans RA, which results in craniofacial malformations comparable to those that characterize mandibulofacial dysostosis in man. Pregnant NMRI mice were treated with 60 mg/kg body weight of all-trans RA, given orally on day 9 of gestation; embryos were taken 4, 12 or 24 hr after RA administration. The apoptotic pattern of RA-induced cell deaths was confirmed using the dUTP biotin nick-end labeling (TUNEL) method and transmission electron microscopy (TEM). HSP110 expression was detected using an immunohistochemical approach. The increase in the number of TUNEL-positive cells and HSP110-positive cells after all-trans RA administration was quantified in the first branchial arch using a computerized method. Twelve hours after RA administration, the increase in the number of HSP110-positive cells is greater than the increase in the number of TUNEL-positive cells. Twenty-four hours after RA administration, only TUNEL-positive cells remain strong in number. We suggest that HSP110 expression could represent a biochemical event of apoptotic cell death induced by RA, associated with early stages of the apoptotic process. In order to find out if HSP110 expression resulted from neosynthesis, we performed in situ hybridization, which demonstrated that the expression of HSP110 occurred at the level of mRNA.

Animals↗
PubMedDate not supplied

[Obliterating parietal hemodissection of the intracranial vessels in young patients. Anatomo-pathologic study and review of the literature].

On the occasion of a new case of intraparietal hematoma of the basilar artery in a 22-year-old male the authors connect this lesion with an anatomoclinical entity which may be called "obliterating parietal hemodissection". It occurs in the cerebral vessels (sylvian or basilar artery) free from any alteration type athero-sclerosis, syphilis or medianecrosis. The anomaly of the elastic fibers risks to fail to be recognized if it is not systematically serchead for in all cases of apparently primary thrombosis occuring in the cerebral vessels.

Adolescent↗
PubMedDate not supplied

[The demonstration of a system of elastic fibers in a study of fibromatous lesions of the oral mucosa].

The elastic fibers system, as visualised by orcein after potassium peroxymonosulfate oxidation in fibromatous lesions of the oral mucosa, is generally sparse. Rich orcein + fibers network was observed in only 5 of our 20 cases of reactive fibromas. Orcein + fibers are absent in the inflammatory areas. These observations rise the problem of the elastogenesis by the fibroblast in healing and neoplasia, and confirm the role played by the proteolytic enzymes during inflammation.

Biopsy↗
PubMedDate not supplied

[The surface status of polished restoration biomaterials after the use of a sodium bicarbonate spray: scanning electron microscopy].

The effects of an air-abrasive system on polished surfaces of restorative materials have been studied using scanning electron microscopy, metrology and profilography. Polished surfaces of composite resin, of amalgam and gold alloy show different alteration types in microtopography, in profile tracings and significant increased surface roughness after air-abrasive spraying; but ceramic and non-precious alloy surfaces are not affected. The composite resin surfaces should be repolished and amalgam and gold alloy surfaces made glossy after use of an air-abrasive system.

Bicarbonates↗
PubMedDate not supplied

Langerhans cells in odontogenic cysts. A retrospective study based on 142 cases.

Dendritic cells with the ultrastructural and immunocytochemical characteristics of Langerhans cells are commonly identified in lymphoid organs and in keratinized and non-keratinized epithelia, such as oral mucosa. These types of cells were previously described in the epithelial wall of periapical odontogenic cysts. S-100 protein positive cells were demonstrated immunocytochemically in all of our 142 cases of odontogenic cysts (32 developmental cysts; 110 inflammatory cysts). Their tropism for squamous epithelia may explain their presence in the epithelial wall of odontogenic cysts. Their number is not always correlated with an inflammatory condition.

Epithelium↗