Syndactyly induced by Janus Green B in the embryonic chick leg bud: a reexamination

Development ◽  
1984 ◽  
Vol 84 (1) ◽  
pp. 159-175
Author(s):  
M. A. Fernandez-Teran ◽  
J. M. Hurle
Keyword(s):  
Vital Staining ◽  
Inhibitory Effect ◽  
Neutral Red ◽  
Epithelial Tissue ◽  
Structural Modifications ◽  
Janus Green ◽  
Mesenchymal Tissue ◽  
Whole Mount ◽  
Direct Inhibitory Effect ◽  
Interdigital Cell Death

In an attempt to clarify the mechanism of production of the syndactyly induced by Janus Green B (JGB) we have studied the morphology and structural modifications of the chick embryo leg bud after JGB administration by means of (1) neutral red vital staining, (2) whole-mount cartilage staining and (3) light microscopy and transmission and scanning electron microscopy. The results show that the well-known inhibition of interdigital cell death is accompanied by a precocious alteration of the epithelial tissue and especially of the epithelial-mesenchymal interface. 24 h after JGB administration the cells of the AER reduce the number of junctions and the basal ectodermal cells are detached into the mesenchymal tissue in zones in which the basal lamina undergoes disruption. In addition the interdigital mesenchymal cells diverted from the dying program are able to undergo a rapid differentiation into cartilage. It is proposed that the mechanism of production of JGB-induced syndactyly might be due to an alteration of the normal epithelial—mesenchymal interactions rather than to a direct inhibitory effect of the JGB on the dying program.

Interdigital tissue chondrogenesis induced by surgical removal of the ectoderm in the embryonic chick leg bud

Development ◽  
1986 ◽  
Vol 94 (1) ◽  
pp. 231-244
Author(s):  
J. M. Hurle ◽  
Y. Gañan
Keyword(s):  
Cell Death ◽  
Vital Staining ◽  
Mesenchymal Cell ◽  
Neutral Red ◽  
Surgical Removal ◽  
Experimental Conditions ◽  
Local Inhibition ◽  
Dorsal Ectoderm ◽  
Interdigital Cell Death ◽  
Proximal Zone

In the present work, we have analysed the possible involvement of ectodermal tissue in the control of interdigital mesenchymal cell death. Two types of experiments were performed in the stages previous to the onset of interdigital cell death: (i) removal of the AER of the interdigit; (ii) removal of the dorsal ectoderm of the interdigit. After the operation embryos were sacrificed at 10–12h intervals and the leg buds were studied by whole-mount cartilage staining, vital staining with neutral red and scanning electron microscopy. Between stages 27 and 30, ridge removal caused a local inhibition of the growth of the interdigit. In a high percentage of the cases, ridge removal at these stages was followed 30–40 h later by the formation of ectopic nodules of cartilage in the interdigit. The incidence of ectopic cartilage formation was maximum at stage 29 (60%). In all cases, cell death took place on schedule although the intensity and extent of necrosis appeared diminished in relation to the intensity of inhibition of interdigital growth and to the presence of interdigital cartilages. Ridge removal at stage 31 did not cause inhibition of the growth of the interdigit and ectopic chondrogenesis was only detected in 3 out of 35 operated embryos. Dorsal ectoderm removal from the proximal zone of the interdigit at stage 29 caused the chondrogenesis of the proximal interdigital mesenchyme in 6 out of 18 operated embryos. The pattern of neutral red vital staining was consistent with these results revealing a partial inhibition of interdigital cell death in the proximal zone of the interdigit. It is proposed that under the present experimental conditions the mesenchymal cells are diverted from the death programme by a primary transformation into cartilage.

Further Observations on the Secretory Cells in the Optic Tentacles of Helix, with Special Reference to the Results of Vital Staining

1964 ◽  
Vol s3-105 (69) ◽  
pp. 61-71
Author(s):  
NANCY J. LANE
Keyword(s):  
Special Reference ◽  
Calcium Salt ◽  
Vital Staining ◽  
Neutral Red ◽  
Nuclear Bodies ◽  
Secretory Cells ◽  
Oval Cells ◽  
Epithelial Surface ◽  
Janus Green ◽  
Inner Surface

When the collar cells or the lateral cells in the tentacles of Helix aspersa are stained with neutral red and other vital dyes, uptake of the dyes occurs chiefly in the lipoidal β-bodies. Janus green B and dahlia are taken up by the mitochondria. In vitally-coloured preparations, no ‘peri-nuclear bodies’ are present in the collar and lateral oval cells, such as were previously found in these cells after post-osmication for 14 days. Fixed preparations of similar cells, post-osmicated for different periods, indicate that the peri-nuclear dictyosomes are artifacts due to over-impregnation with osmium. In addition to the lateral oval and lateral processed cells, which lie at intervals along the inner surface of the dermo-muscular sheath in Helix, unicellular calcium glands are found, lying immediately beneath the epithelial surface; these are far more numerous in H. pomatia than in H. aspersa. They contain granules of a calcium salt suspended in a matrix of mucopolysaccharide, and apparently produce the whitish mucoid secretion that is extruded on to the surface of the tentacles when the animal is disturbed. There is no evidence to suggest that the lateral cells are concerned in the production of this mucoid secretion.

Effects of oestradiol benzoate (OeB) and human chorionic gonadotrophin (hCG) on the testes and accessory sex glands of the rat

1981 ◽  
Vol 96 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Mridula Chowdhury ◽  
Robert Tcholakian ◽  
Emil Steinberger
Keyword(s):  
Treated Group ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Control Group ◽  
Intact Male ◽  
Intact Control ◽  
Testosterone Levels ◽  
Oestradiol Benzoate ◽  
Direct Inhibitory Effect

Abstract. It has been suggested that treatment of intact male rats with oestradiol benzoate (OeB) causes an interference with testosterone (T) production by the testes by a direct inhibitory effect on steroidogenesis. To test this hypothesis, different doses (5, 10 or 25 IU) of hCG were administered concomitantly with 50 μg of OeB to adult intact or hypophysectomized male rats. The testicular and plasma testosterone, and serum hCG levels were determined. The sex accessory weights were recorded. In the intact OeB-treated group of animals, hCG stimulated both the secondary sex organs and plasma testosterone levels above the intact control group. However, in hypophysectomized animals, although plasma testosterone levels increased above that of intact controls, their secondary sex organ weights did not. Moreover, inspite of high circulating hCG levels, the testicular testosterone content and concentration remained suppressed in OeB-treated animals. The reason for such dichotomy of hCG action on OeB-treated animals is not clear at present.

scholarly journals A novel radiolytic rotenone derivative, rotenoisin A, displays potent anticarcinogenic activity in breast cancer cells

2021 ◽  
Author(s):  
Dong-ho Bak ◽  
Seong Hee Kang ◽  
Chul-hong Park ◽  
Byung Yeoup Chung ◽  
Hyoung-Woo Bai
Keyword(s):  
Breast Cancer ◽  
Adverse Effects ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Parent Compound ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Epidermal Keratinocytes ◽  
Functional Changes ◽  
Structural Modifications

Abstract Chemotherapy for cancer treatment has therapeutic limitations, such as drug resistance, excessive toxic effects and undesirable adverse effects. Therefore, efforts to improve the safety and efficacy of chemotherapeutic agents are essential. Ionizing radiation can improve physiological and pharmacological properties by transforming structural modifications of the drug. In this study, in order to reduce the adverse effects of rotenone and increase anticancer activity, a new radiolytic rotenone derivative called rotenoisin A was generated through radiolytic transformation. Our findings showed that rotenoisin A inhibited the proliferation of breast cancer cells and increased the rate of apoptosis, whereas it had no inhibitory effect on primary epidermal keratinocytes compared with rotenone. Moreover, rotenoisin A-induced DNA damage by increasing reactive oxygen species (ROS) accumulation. It was also confirmed not only to alter the composition ratio of mitochondrial proteins, but also to result in structural and functional changes. The anticancer effect and molecular signalling mechanisms of rotenoisin A were consistent with those of rotenone, as previously reported. Our study suggests that radiolytic transformation of highly toxic compounds may be an alternative strategy for maintaining anticancer effects and reducing the toxicity of the parent compound.

scholarly journals Mechanism of Transforming Growth Factor β–induced Inhibition of T Helper Type 1 Differentiation

2002 ◽  
Vol 195 (11) ◽  
pp. 1499-1505 ◽  
Author(s):  
Leonid Gorelik ◽  
Stephanie Constant ◽  
Richard A. Flavell
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Inhibitory Effect ◽  
Interleukin 12 ◽  
T Helper ◽  
Retroviral Transduction ◽  
Cell Functions ◽  
Proliferation And Differentiation ◽  
Direct Inhibitory Effect

Regulation by transforming growth factor (TGF)-β plays an important role in immune homeostasis. TGF-β inhibits T cell functions by blocking both proliferation and differentiation. Here we show that TGF-β blocks Th1 differentiation by inhibiting the expression of T-bet, the apparent masterregulator of T helper (Th)1 differentiation. Restoration of T-bet expression through retroviral transduction of T-bet into developing Th1 cells abrogated the inhibitory effect of TGF-β. In addition, we show that, contrary to prior suggestions, downregulation of interleukin 12 receptor β2 chain is not key to the TGF-β–mediated effect. Furthermore, we show that the direct inhibitory effect of TGF-β on T cells is responsible, at least in part, for the inability of BALB/c mice to mount a Leishmania-specific Th1 response and to clear Leishmanial infection.

Human kidney 11β-hydroxysteroid dehydrogenase: regulation by adrenocorticotropin?

1996 ◽  
Vol 134 (3) ◽  
pp. 301-307 ◽  
Author(s):  
S Diederich ◽  
M Quinkler ◽  
K Miller ◽  
P Heilmann ◽  
M Schöneshöfer ◽  
...  
Keyword(s):  
Human Kidney ◽  
Kinetic Studies ◽  
Hydroxysteroid Dehydrogenase ◽  
Inhibitory Effect ◽  
Benjamin Franklin ◽  
Dependent Inhibition ◽  
Direct Inhibitory Effect ◽  
Dose Dependent Inhibition ◽  
Endogenous Substrates ◽  
Radioactive Detection

Diederich S, Quinkler M, Miller K, Heilmann P, Schöneshöfer M, Oelkers W. Human kidney 11βhydroxysteroid dehydrogenase: regulation by adrenocorticotropin? Eur J Endocrinol 1996;134:301–7. ISSN 0804–4643 In ectopic adrenocorticotropin (ACTH) syndrome (EAS) with higher ACTH levels than in pituitary Cushing's syndrome and during ACTH infusion, the ratio of cortisol to cortisone in plasma and urine is increased, suggesting inhibition of renal 11β-hydroxysteroid dehydrogenase (11β-HSD) by ACTH or by ACTH-dependent steroids. Measuring the conversion of cortisol to cortisone by human kidney slices under different conditions, we tested the possibility of 11β-HSD regulation by ACTH and corticosteroids. Slices prepared from unaffected parts of kidneys removed because of renal cell carcinoma were incubated with unlabeled or labeled cortisol, and cortisol and cortisone were quantitated after HPLC separation by UV or radioactive detection. The 11β-HSD activity was not influenced by incubation with increasing concentrations (10−12–10−9 mol/l) of ACTH (1–24 or 1–39) for 1 h. Among 12 ACTH-dependent steroids tested (10−9–10−6 mol/l), only corticosterone (IC50 = 2 × 10−7 mol/l), 18-OH-corticosterone and 11βOH-androstenedione showed a significant dose-dependent inhibition of 11β-HSD activity. The percentage conversion rate of cortisol to cortisone was concentration dependent over the whole range of cortisol concentrations tested (10−8–10−5 mol/l). A direct inhibitory effect of ACTH on 11β-HSD is, therefore, unlikely. The only steroids inhibiting the conversion of cortisol to cortisone are natural substrates for 11β-HSD Kinetic studies show a saturation of the enzyme at high cortisol concentrations. Thus, the reduced percentage renal cortisol inactivation in EAS seems to be due mainly to overload of the enzyme with endogenous substrates (cortisol, corticosterone and others) rather than to direct inhibition of 11β-HSD by ACTH or ACTHdependent steroids, not being substrates of 11β-HSD. S Diederich, Department of Endocrinology, Klinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin, Germany

The DaXa-inhibition assay: A concept for a readily available, universal aXa assay that measures the direct inhibitory effect of all anti-Xa drugs

2018 ◽  
Vol 168 ◽  
pp. 63-66 ◽  
Author(s):  
L.Joost van Pelt ◽  
Michaël V. Lukens ◽  
Sophie Testa ◽  
Bernard Chatelain ◽  
Jonathan Douxfils ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Inhibition Assay ◽  
Direct Inhibitory Effect

scholarly journals Direct Inhibitory Effect of Fluoxetine on TREK-2 Channel

2012 ◽  
Vol 102 (3) ◽  
pp. 680a ◽  
Author(s):  
Dawon Kang ◽  
Eun-Jin Kim ◽  
Jaehee Han
Keyword(s):  
Inhibitory Effect ◽  
Direct Inhibitory Effect
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