Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue.

Conventional visual examination and palpation remains the gold-standard for the identification of oral mucosal lesions. The purpose of this study was to investigate the adjunctive value of a chemiluminescent light source (ViziLite, Zila Pharmaceuticals, Phoenix, Arizona) and application of pharmaceutical grade toluidine blue (TBlue(630), Zila Pharmaceuticals, Phoenix, Arizona) to further assess lesions identified during the conventional oral soft tissue examination. Lesions deemed clinically suspicious by visual examination under incandescent light were further assessed under chemiluminescence and then application of toluidine blue stain. Differences between the conventional visual examination and chemiluminescent examination were noted on four characteristics which may aid in lesion identification. Tissue retention of toluidine blue stain was documented. Each suspicious lesion was biopsied and diagnosed based upon routine histopathology. Both adjunctive exams were evaluated by comparing the histologic diagnosis. The additive value of toluidine blue stain retention was assessed in lesions diagnosed as "serious pathology" defined as severe dysplasia, carcinoma in situ and squamous cell carcinoma. Ninety-seven clinically suspicious lesions in 84 patients were identified. The chemiluminescent exam improved the brightness and/or sharpness of margin in 61.8% of identified lesions. Biopsied lesions with toluidine blue stain retention reduced the false positive rate by 55.26% while maintaining a 100% negative predictive value (NPV). Chemiluminescence was shown to increase the brightness and margins of mucosal lesions in a majority of cases and therefore may assist in identification of mucosal lesions not considered under traditional visual examination. Toluidine blue stain retention was associated with a large reduction in biopsies showing benign histology (false positive biopsy results), while maintaining a 100% NPV for the presence of severe dysplasia or cancer. Practitioners may consider use of these adjuncts in practice, however the results presented are based upon experienced providers in referral centers for mucosal disease or cancer centers and therefore positive findings may be an indication for referral to experienced providers.

Structural and immunohistological modifications in olfactory bulb of the staggerer mutant mouse.

In the present study, we describe the structural and cytological changes observed in staggerer mutant olfactory bulbs, as compared to normal mice. On the basis of photonic and ultrastructural observations we tried to define the alterations induced by the mutation: i.e. a reduction of bulb size, a reduction in the volume of three out of the six architectonic layers (glomerular, external and internal plexiform), a reduction of glomeruli size, a loss of half the mitral cells and a slight decrease in juxtaglomerular interneuron number. In staggerer, an hypertrophy of glial ensheathing cell processes was especially evident at the level of each glomerulus, whereas the density of the astrocyte network was weaker in the granular layer and the nerve layer not apparently impaired. An immunofluorescent labelling study combined with confocal scanning microscopy was performed in order to identify the cellular type and the differentiation degree of the various elements. Antibodies anti-GFAP, a protein present in both ensheathing cells and astrocytes, and anti-OMP, the specific maturation protein of the nerve layer, were used for that purpose. Data confirmed the reality of the gliosis and the persistence of the sensory component in the mutant. All the structural alterations described in staggerer olfactory bulb were in close agreement with the functional troubles previously recorded. Our results are discussed in connection with the present knowledge on embryonal origin, fetal development and adult cellular renewal of the olfactory bulb.

Antibody-coated electrodes for detecting somatic exocytosis of somatostatin-like material in Helix neurones.

Immunoelectrodes have been developed which can be used to detect minute amounts of somatostatin. They were made with electrochemically treated glassy carbon fibres coated with anti-somatostatin antibodies. Calibration and various controls were carried out to ensure that the immunoelectrodes responded specifically to the presence of femtomolar somatostatin. Electrophysiological experiments were performed on anti-somatostatin immunoreactive neurones in the snails Helix aspersa and H. pomatia. Somatostatin-like material was released in response to sustained firing. The release was measured at the soma, which means that it occurred in the extrasynaptic area. The finding that the fluorescent dye FM 1-43 was incorporated into somatic vesicles confirmed that exocytosis actually occurred during sustained neuronal firing.

[Modifications of the olfactory bulb electrocorticogram and trans-glomerular evoked potentials in staggerer mutant mice]. / Modifications de l'électrocorticogramme du bulbe olfactif et des potentiels évoqués transglomérulaires chez la souris mutante cérébelleuse staggerer.

Electrophysiological observations have been made on normal C57-BL/6J and staggerer mutant mice. Morphological observations have given evidence it existed various neurones modifications which affected the olfactory bulb in the mutant mice. Olfactory bulb electrocorticograms (ECoG) of mutant have shown rare bursts of potentials of longer time duration than in normal mice. These bursts were less affected by odor stimulations (ammonia and urine of opposite sexes) than in the normal mice and never varied under urine odor influence in female mutant. Evoked potential induced by the odors had long latency and long duration (up to 50 ms vs 30 ms). In a large amount of them, the late phases and the late oscillatory potentials, which generally followed the evoked potential, were absent. All these results improved the idea that staggerer mutation, which mainly affected the N-CAM gene, not only induced cerebellar diseases, but also functionally affects the olfactory bulb.

In vitro effects of methionine-enkephalin, somatostatin and insulin on cultured gonadal cells of the snail Helix aspersa.

Isolated snail gonadal cells were cultured in the presence of synthetic neuropeptides in order to determine the subsequent effect of these substances on gonadal synthetic activities. Gonadal cells were incubated for 24 h in concentrations of methionine-enkephalin, somatostatin and insulin ranging from 10(-4) M to 10(-9) M, in medium 199 supplemented with 6% Ultroser G. Synthesis of DNA and protein by the cultured cells were simultaneously estimated by measuring incorporation of 3H thymidine and 35S methionine. The rate of labelled precursor incorporation was measured using the liquid scintillation technique. All substances tested exerted a dose-dependent effect. The synthetic activity of the cultured cells was highest when the concentration of the peptides added to the medium approximated the physiological levels. Methionine-enkephalin, somatostatin and insulin at 2 x 10(-8) M significantly increased 3H thymidine incorporation, by 62%, 69% and 69% respectively, and protein synthesis by 42%, 57% and 57%, respectively. In the case of juvenile gonadal cultured cells, a similar increase in 3H and 35S incorporation was registered for a 10(-7) M peptide concentration. Both lower and higher peptide concentrations inhibited 3H thymidine and 35S methionine incorporation. Pharmacological studies suggest the existence of methionine-enkephalin and somatostatin-like receptors on snail gonadal cells. These results indicate that our gonadal cell culture model provides a useful tool for the study of the neuroendocrinological control of the activity of snail gonadal cells.

The synthesis of vitellogenins by the digestive gland of Helix aspersa: evidence from cell-free translation of mRNA.

All the RNAs were extracted separately from the gonads and digestive glands of the garden snail Helix aspersa. After separation by oligo-dT-cellulose chromatography, the mRNA were evaluated using optical density measurements and agarose gel electrophoretic analysis and then used in a cell-free translation system: a rabbit reticulocyte lysate added with 35S methionine. The in vitro synthesized proteins were characterized by immunoprecipitation with polyclonal antibodies which were raised against mature oocyte proteins. The proteins were then evaluated quantitatively using liquid scintillation counting and qualitatively using SDS polyacrylamide gel electrophoresis and fluorography. The results demonstrated that the digestive gland of the garden snail is a vitellogenin synthesis site.

[Development of a bioassay from gonadal cellular cultures of the snail Helix aspersa: influence of nerve ganglion extracts on the synthetic activity of the target cells]. / Réalisation d'un bioessai à l'aide de cultures cellulaires gonadiques d'escargot: influence d'extraits de ganglions nerveux sur l'activite synthetique des cellules cibles.

To realize bioassays a primary culture method was carried out with dissociated cells from the garden snail gonads. ADN and protein syntheses of gonadal cells were estimated using the liquid scintillation method. The gonadal cells were obtained from either adults of Petits Gris and Gros Gris, or young Gros Gris. The results were remarkably homogeneous. The brain extracts added to the culture medium had an inhibitory dose dependent effect on the synthetic activity of gonadal cells. The effected bioassays permit quantitative estimation on the variations of the brain extracts effect in relation to the physiological states of the snail and on the evolution of target cells' receptors during the growth of Gros Gris.

Localization of yolk proteins and their possible precursors using polyclonal and monoclonal antibodies, in Helix aspersa.

Three major yolk proteins of 140, 100, 80 KD and a faint band of 440 KD were determined by gradient gel electrophoresis in the mature eggs of Helix aspersa. Polyclonal and monoclonal antibodies were raised against mature oocyte extracts. The binding sites of these rabbit and hybridoma antibodies with the different yolk protein components were identified with a combination of WESTERN blotting, ELISA, immunofluorescence and immunogold staining. All these techniques demonstrated materials immunologically similar to vitellins in the hemolymph and in the glandular cells of the digestive gland. The data suggest that, for its vitellogenesis, the garden-snail utilizes a heterosynthetic mechanism similar to that known in oviparous animals. The vitellogenins would be produced by the digestive gland.

[Electrophoresis of native cardiac myosin in Anura amphibians]. / Electrophorèse de myosine native de coeurs d'Amphibiens Anoures.

Electrophoresis in non dissociating conditions of native cardiac myosin was adapted to the study of Amphibian myosin. Utilization of potassium ion has allowed to obtain a good separation of myosin isoenzymes. An evolution of isoenzymic composition of cardiac myosin during metamorphosis and aging in Xenopus laevis (Daudin) was observed.

[Detection of collagen by immunofluorescence during development of Xenopus (Xenopus laevis Daud.)]. / Mise en évidence du collagène par immunofluorescence au cours du développement du Xénope (Xenopus laevis Daud.).

Appearance of the different collagen types was studied during the clawed toad development from hatching to metamorphosis, using indirect immunofluorescence techniques. Type-like IV collagen of basement membranes was first seen in the notochord streath. Type I, type II were detected at the same time, followed by type III. Developmental sequence and distribution of the four collagen types indicate the different stages of organogenesis.

[Effects of alpha-amanitin on the development of Xenopus (Xenopus laevis Daud.) heart in vitro]. / Effets de l'alpha-amantine sur le développement du coeur de Xénope (Xenopus laevis Daud.) in vitro.

The differentiation of Xenopus heart is studied in vitro, in the presence of alpha-amanitin. The results obtained depend on the concentration of the inhibitor, the length of treatment and the stage of primordium. The mRNA pool assures the differentiation of explants, removed from young stages, for 12 hours. This time is half for the primordia removed from stages greater than 3,5 mm.

[Differentiation of the prostate in the snail Helix aspersa Müll]. / Différenciation de la prostate chez l'escargot Helix aspersa Müll.

The differentiation of the snail Helix aspersa prostate gland is studied in animals from one to six months old. After the presentation of organogenesis the primary stage of secretion (3 months) and a stage where the prostate gland shows abundant secretions (6 months) were described; but the oviduct is still indifferentiated. The ultrastructural analysis shows the formation of secretory and ciliated cells in epithelioid prostatic tubes.

[Ulstrastructure of Xenopus heart primordia, differentiated in culture in the presence of actinomycin D]. / Etude ultrastructurale des ébauches cardiaques de Xénope, différenciées en culture en présence d'actinomycine D

The cellular differentiation of Xenopus laevis cardiac primordia, developed in vitro with actinomycin D, was studied in fine structure. The ultrastructural changes appeared in mitochondria, and in nucleus, which showed a nucleolar characteristic segregation.

[Influence of actinomycin D on Xenopus heart differentiation in organ culture]. / Influence de l'actinomycine D sur la differenciation cardiaque du xénope en culture organotypique

The cardiac differentiation of the African clawed Toad was studied in culture with Actinomycin D. In terms of drug amounts used and the duration of treatment, a limit coefficient was defined, beyond which the heart did not again differentiate. The results were interpreted by the existence of a threshold in the inhibition of ARNr synthesis, whose total turn-over seemed to be 24 hours.

[Development of heart innervation in Xenopux tadpole and relationship with organ function]. / Etablissement de l'innervation dans le coeur du têtard de Xénope et ses répercussions sur le fonctionnement de l'organe

Cardial innervation is studied through specific techniques. It is set up in 9 to 18 mm tadpoles. The rhythm of the aneural heart progressively increases. The initial automatic working is of ventricular type. The ventricular action potential acquires its typical form after the establishment of innervation. At the same time, cardial rhythm settles down at 110 beatings/minute.

Yes, you can teach clinical skills in the classroom!

This paper describes the use of videotaped interviews with volunteer patients as a method of teaching interviewing skills to first and second year occupational therapy students. It is hoped that this experience will enable students to conduct interviews in clinical or community settings with greater confidence and effectiveness.