Influence de la Papaïne sur le Tibia Embryonnaire de Poulet cultivé in Vitro

Development ◽  
1962 ◽  
Vol 10 (3) ◽  
pp. 231-247
Author(s):  
par Henri Girard
Keyword(s):  
Cette Action

L'action de la papaïne sur le cartilage a été beaucoup étudiée depuis l'expérience spectaculaire réalisée par Thomas (1956): l'injection intraveineuse d'une solution de papaïne chez le lapin provoqua l'affaissement des oreilles par suite de la disparition de la matrice interstitielle (ou substance fondamentale) du cartilage. Le phénomène est temporaire: le cartilage revient à l'état normal et les oreilles reprennent leur fermeté quelques jours plus tard. Spicer & Bryant (1957), Bryant, Leder & Stetten (1958) apportèrent quelques précisions histologiques. McCluskey & Thomas (1958) décelèrent le facteur actif de cette action: une protéase, qui fut isolée cristallisée à partir de la papaïne. Tsaltas (1958 a, b), Bryant et al. (1958) vérifièrent que l'injection de papaïne provoque la libération de mucopolysaccharides dans le sang. Ces expériences furent menées sur des individus adultes ou jeunes (lapins, souris). Fell & Thomas (1960) les étendirent à l'embryon de poulet en comparant l'action de la papaïne à celle de la vitamine A.

Observations sur la différenciation in vitro des cellules myéloïdes d'embryons de poulet

Development ◽  
1968 ◽  
Vol 19 (2) ◽  
pp. 145-155
Author(s):  
Par Germano Salvatorelli ◽  
Carlo Callegarini ◽  
Anna Maria Gulinati ◽  
Giuseppe Gardenghi
Keyword(s):  
Cette Action

L'association de fragments de foie embryonnaire à des cultures organotypiques de moelle osseuse d'embryons de poulet s'est montrée tràs favorable au maintien, pendant une période de culture de 15 jours, d'une activité érythropoïétique comparable à celle qui se déroule in vivo (Salvatorelli, 1966, 1967b). Ce résultat expérimental nous a permis de conclure, comme hypothèse de travail, que le foie embryonnaire du poulet est le lieu de production d'un ou de plusieurs facteurs érythropoïétiques qui stimulent, soit la prolifération des hémocytoblastes, soit leur différenciation en élements de la série rouge. Il nous a été ensuite possible de démontrer que ce ou ces facteurs érythropoïétiques hypothétiques présents dans le foie embryonnaire sont capables d'expliquer aussi leur action sur d'autres organes érythropoïétiques embryonnaires telle la rate de poulet (Salvatorelli & Gulinati, 1967). Même l'adjonction d'extraits acellulaires de foie au milieu de culture a montré une action favorable au maintien de l'érythropoïèse et cette action est tout à fait comparable à celle qui est produite par le foie vivant.

Action de la vitamine et de l'antivitamine B6 sur le myocarde d'embryon de poulet cultivé in vitro

Development ◽  
1965 ◽  
Vol 14 (1) ◽  
pp. 53-61
Author(s):  
par G. Conti ◽  
G. Milio
Keyword(s):  
Nous Avons ◽  
Cette Action

Nous avons essayé les effets de la vitamine (PX) et de l'antivitamine B6 (DPX) sur des organes d'embryons de poulet cultivés in vitro; et cela dans le but de voirsi l'action inhibitrice de la DPX se manifestait sur la croissance in vitro des organes et si cette action inhibitrice éventuelle pouvait être annulée, ou du moins partiellement empêchée, par l'adjonction simultanée de la vitamine B6 au milieu de culture. On a réalisé 512 explants de coeur d'embryons de poulet de 9 jours; le matériel à explanter a toujours été prélevé sur le ventricule gauche. Les explants ont été cultivés sur le milieu de culture mis au point par Wolff et Haffen en 1952 (milieu standard). La DPX et la PX ont été dissoutes dans du liquide de Tyrode et ajoutées à différentes doses au milieu de culture. Les cultures ont été maintenues à l'étuve, à 38° C., et contrôlées tous les jours au stéréomicroscope.

Mise en évidence du rôle inducteur de l'encéphale dans l'ostéogenèse du crâne embryonnaire du poulet

Development ◽  
1968 ◽  
Vol 19 (1) ◽  
pp. 83-94
Author(s):  
Par Jean Schowing
Keyword(s):  
Nous Avons ◽  
Cette Action

Nos expériences d'excision des différents territoires encéphaliques (Schowing, 1959, 1961, 1967) mettent en évidence l'importance du rôle des structures nerveuses dans la différentiation du squelette cranien. Le mécanisme de cette action inductrice, ainsi que la nature de l'inducteur, est mal connu. Nous avons tenté de confirmer le rôle inducteur de l'encéphale par des expériences in vitro. Strudel (1959, 1962) a obtenu du cartilage à partir de somites d'embryons de poulet cultivés sur le milieu standard de Wolff & Haffen (1952) contenant un extrait de tube nerveux, tandis que Benoît (1960), greffant un fragment de tube nerveux à la place de la placode otique, a observé l'apparition d'un cartilage surnuméraire dans le mésenchyme de l'oreille. Il semble done qu'il existe un facteur inducteur de la chondrogenèse dans le tube nerveux. De même, existe-t-il un facteur de l'ostéogenèse dans l'encéphale embryonnaire? Ce facteur inducteur est-il spécifique, comme son homologue chondrogène?

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Immunoenzymatic demonstration of the simultaneous presence of transferrin, hemopexin and albumin in a same hepatocyte and their ultrastructural localization

1978 ◽  
Vol 36 (2) ◽  
pp. 88-89
Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau
Keyword(s):  
Plasma Proteins ◽  
Rat Hepatocytes ◽  
Ultrastructural Localization ◽  
Carrier Proteins ◽  
Normal Cells ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Monospecific Antisera ◽  
Different Levels

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

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