Myofibroblasts in healing laser excision wounds.

Background And Objective: The lack of myofibroblasts, cells responsible for wound contraction, has been suggested to be the underlying factor to the clinically observed minimal contraction in CO2 laser wounds. However, the histologic background to this phenomenon in laser excisions has not been thoroughly clarified. Therefore, we analyzed the expression of myofibroblasts in healing laser excisions and control excisions made by scalpel.

Re-establishment of the atomic composition and the oxide structure of contaminated titanium surfaces by means of carbon dioxide laser and hydrogen peroxide: an in vitro study.

Background: In clinical situations with peri-implant bone resorption, re-integration of the exposed implant surface is sometimes preferable, which requires a clean surface. Previous investigations have shown that cleaning of contaminated titanium surfaces using chemical and abrasive methods is difficult.

Purpose: The aim of this investigation was to evaluate the efficacy of different combinations of chemical and physical methods (citric acid, hydrogen peroxide, and carbon dioxide [CO2] laser irradiation) for removal of contaminants and subsequent reconstruction of the surface oxide of intraorally contaminated titanium foils.

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.

Craniofacial abnormalities induced by retinoic acid: a preliminary histological and scanning electron microscopic (SEM) study.

Exogenous retinoic acid has been found to be teratogenic in animals and man. Craniofacial defects induced by retinoic acid have stimulated considerable research interest. The present report deals with scanning electron microscopical observations of the craniofacial region concurrent with histological examination of craniofacial dysmorphism induced in rat embryos following maternal treatment treated with varying dosages of all-trans-retinoic acid (tretinoin).

Chaperones in the parotid gland: localization of heat shock proteins in human adult salivary glands.

Heat shock proteins (HSPs) are expressed or increased in response to various biological stresses. Moreover, these 'stress proteins' seem to be expressed by some cells living in physiological conditions. From then on, they could play an important physiological role in normal cell functioning.

[Expression of heat shock proteins in salivary gland tumors. Immunohistochemical study of HSP27, HSP70, HSP90, and HSP110: apropos of 50 cases].

Heat shock proteins (HSPs) are known to be increased in response to biological stress. Recently some authors described their presence in tumors. Our immunohistochemical investigations revealed the expression of HSP27, HSP70, HSP90 and HSP110 in most of benign tumors of salivary glands (33 cases).

Immunocytochemical investigations of heat shock proteins expression during thymic apoptosis induced by glucocorticoids.

The aim of our study was to investigate a possible expression of different HSPs in rat's thymuses after hydrocortisone administration. The thymuses of 41 young rats (25 to 45 days age old) were studied immunocytochemically: 12 rats were not injected, 8 received an injection of physiological serum, and 21 received HC (125 mg/kg). HSP27, 70 and 110 expression was investigated following the PAP method.

An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants.

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals.

Cytochemical identification of HSP110 during early mouse facial development.

Apoptotic cell death constitutes a common phenomenon observed during development. This process plays an important role in the regulation of cell populations and in early differentiation of embryonic organs. Several teratologic situations are considered as resulting in a dramatic increase of the apoptotic process.

Analysis of titanium dental implants after failure of osseointegration: combined histological, electron microscopy, and X-ray photoelectron spectroscopy approach.

A multitechnique approach has been used to characterize the surface of nonosseointegrated titanium implants and the surrounding biological tissues. Five pure titanium dental implants were used as reference, and 25 removed implants were studied. Surface and in-depth chemical compositions of the implants (from a total of 16 patients) were investigated by X-ray photoelectron spectroscopy (XPS).

Granulomatous vulvitis, granulomatous cheilitis: a single diagnosis?

We report two cases of labial swelling (oral and vulvar) with a granulomatous histology in patients with a history of Crohn's disease. The differential diagnosis of granulomatous vulvitis and cheilitis, as well as the symptomatology and treatment of vulvar and oral Crohn's disease are further discussed. To our knowledge, reported cases of vulvar and oral Crohn's disease are quite scarce in the literature, but the disease might be underdiagnosed.

[Stress proteins: expression of a universal phenomenon of cell defense].

Heat shock proteins or stress proteins play a role in adaptative thermotolerance. All cells, procaryotic and eucaryotic, are able to respond to different cellular aggressions by the synthesis of these stress proteins. In normal physiological conditions, they are considered as "molecular chaperones" Their actual role in pathology is still unknown; some of these heat shock proteins may be correlated with the degree of aggressiveness of some tumors.

[The role of apoptosis during craniofacial development: concepts and importance in pathology].

Apoptosis is an essential common final pathway in numerous pathological conditions such as malignant tumors, HIV-related CD4 lymphocytes degeneration, neurodegenerative disorders, and in programmed cell death events during normal embryogenesis. Some teratogenic substances for man and laboratory mammals induce an increase of the apoptotic phenomenon, responsible for the occurrence of some precise cranio-maxillo-facial malformations. The study of cell death during normal or teratogenic embryonic development allows to analyse the cellular mechanisms implied in the control of the apoptotic phenomenon, together with its dysregulation ending in pathological processes.

Myxomatous odontogenic tumor of the maxilla. An unusual case with squamous and mucoproducing epithelial component.

A tumor attached to the amelo-cemental junction of a third molar impacted in the maxillary tuberosity, consisted histologically of a myxomatous stroma, in which multicystic cavities lined by a columnar epithelium and mucoproducing cells, together with an aggressive squamous epithelial component were present. Although the diagnosis of polyp of the maxillary sinus cannot be excluded, this lesion most likely constitutes an unusual presentation for an odontogenic myxoma of the maxilla, in which an aggressive squamous epithelial component is present, along with a mucosecreting glandular component.

Strong expression of heat shock proteins in growth plate cartilage, an immunohistochemical study of HSP28, HSP70 and HSP110.

Heat shock proteins (HSPs) are known to be increased in response to stresses. Our immunohistochemical investigations revealed the strong expression of a wide range of HSPs in the chondrocytes of the tibial growth plate cartilage from young rats. HSP28 and HSP70 are expressed in the upper part of the hypertrophic zone of the growth plate cartilage.

Scanning electron microscopic and immunocytochemical studies of contraction during secondary CO2 laser wound healing in rat tongue mucosa.

An experimental model was established in which the decrease in surface area of CO2 laser wounds on rat tongues was measured during the healing process. Scanning electron microscopy was used to measure and delineate the outlines of the initial wounds and those of the residual wounds. A 50% decrease in the surface area of the wounds was observed 10 days after surgery during the healing process.

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).

Histopathology and ultrastructure of the thymus in OP/OP rats with special focus on thymic macrophages. Effect of bone marrow transplantation.

The thymi of op/op rats were investigated before and after bone marrow graft. Normal littermates were used as controls. The thymic involution and atrophy in non-treated op/op rats was characterized by the presence of pyknotic thymocytes (apoptosis) and numerous lipid-laden macrophages containing pleiomorphic lysosomes.

[Sebaceous carcinoma. Apropos of an extra-ocular location].

Sebaceous carcinomas of the skin are rare tumors. They most often occur on the skin of the head and neck. Their clinical diagnosis is difficult and the evolution is unpredictable.

Experimental odontomas in osteopetrotic op/op rats.

Osteopetrosis is an autosomal recessive disease in several mammalian species. Osteopetrotic op/op rats suffer from complete failure of tooth eruption related to reduced bone resorption. In our earlier studies, op/op rats grafted with bone marrow cells 3 days after birth were cured of the disease and their molar eruption was restored.

Immune cell defects affect bone remodelling in osteopetrotic op/op mice.

The aim of the present work was to further characterize immunological defects in osteopetrosis. The op/op mutant mouse is of particular interest since a marrow cavity develops spontaneously in older animals. The interleukin production (IL-1, IL-2, IL-3, IL-4, IL-6), the presence of macrophage differentiation antigens and the evolution of the bone lesions were studied in osteopetrotic and normal mice.