Development of embryonic rat eyes in organ culture

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 407-414
Author(s):  
R. Christy Armstrong ◽  
Joel J. Elias
Keyword(s):  
Organ Culture ◽  
Culture Medium ◽  
Folic Acid Deficiency ◽  
Experimental Conditions ◽  
Acid Deficiency ◽  
Series Of Experiments ◽  
Development In Vitro ◽  
Ocular System

Abnormalities of the ocular system which appear in organ culture in Waymouth's medium with freshly added glutamine (Armstrong & Elias, 1968) resemble those caused by transitory pteryolglutamic acid (PGA or folic acid) deficiency in vivo (Armstrong & Monie, 1966). The configurations of such malformations as lens herniations, retinal diverticula, and rosette-like formations of the retina are remarkably similar in both cases. The experiments reported in this paper were undertaken in an effort to understand the mechanisms involved in the production of similar abnormalities by two very different experimental conditions: the addition of glutamine in vitro and the transitory deficiency of PGA in vivo. One series of experiments involved the effects of manipulation of the PGA and glutamine content of the culture medium on eye development in vitro. Parallel studies on PGA-deficiency in vivo were undertaken in conjunction with organ-culture experiments in order to compare the effects on abnormal eye morphogenesis.

CORRELATION BETWEEN THE EFFECTS OF HORMONES ON THE SYNTHESIS OF DNA IN EXPLANTS FROM INDUCED RAT MAMMARY TUMOURS AND THE GROWTH OF THE TUMOURS

1974 ◽  
Vol 62 (2) ◽  
pp. 225-240 ◽  
Author(s):  
D. LEWIS ◽  
R. C. HALLOWES
Keyword(s):  
Organ Culture ◽  
Dna Synthesis ◽  
Culture Medium ◽  
Mammary Glands ◽  
Sprague Dawley ◽  
Culture Techniques ◽  
Mammary Tumours ◽  
Sprague Dawley Rats

SUMMARY Explants from 32 mammary tumours induced in Sprague—Dawley rats by 9,10-dimethyl-1,2-benzanthracene (DMBA) were maintained in organ culture for up to 48 h. Insulin, corticosterone, prolactin, growth hormone and oestradiol were added to the culture medium in various combinations and their effects on the DNA synthesis of the explants was studied. DNA synthesis was stimulated by insulin in explants from 30 out of the 32 tumours examined and this group of 30 responsive tumours could be further subdivided. Explants from 16 tumours showed a greater rate of DNA synthesis in medium containing insulin plus corticosterone plus prolactin than in medium containing insulin alone and this higher rate was decreased by oestradiol; this group is referred to as 'prolactin-responsive'. Explants from the remaining 14 tumours did not show a greater rate of DNA synthesis in medium that contained insulin plus corticosterone plus prolactin than in medium containing insulin alone and neither rate was decreased by oestradiol; this group is referred to as 'insulin-responsive'. Explants from two tumours were not stimulated by insulin and these tumours are referred to as 'non-responsive'. After oophorectomy or administration of ergocryptine to tumour-bearing rats, the prolactin-responsive tumours regressed whereas the non-responsive tumours continued to grow. Explants taken from prolactin-responsive tumours 2 weeks after either oophorectomy or administration of ergocryptine were still prolactin-responsive but those taken from insulin-responsive tumours 2 weeks after the same treatment were now also prolactin-responsive. The non-responsive tumours remained non-responsive. The effects of hormones on the DNA synthesis in vitro of explants from growing DMBA-induced tumours were thus different from those on explants of mammary glands from virgin or pregnant Sprague—Dawley rats. It was concluded that it was possible to predict by organ culture techniques the response in vivo of growing mammary tumours to oophorectomy and ergocryptine administration.

scholarly journals Collagen metabolism in folic acid deficiency

1974 ◽  
Vol 32 (2) ◽  
pp. 457-469 ◽  
Author(s):  
J. G. A. J. Hautvast ◽  
M. J. Barnes
Keyword(s):  
Ascorbic Acid ◽  
Protein Synthesis ◽  
Folic Acid ◽  
Growth Characteristic ◽  
Male Rats ◽  
Folic Acid Deficiency ◽  
Collagen Formation ◽  
Acid Deficiency

1. The effect of folic acid deficiency on collagen formation, with respect to the level of collagen-protein synthesis and the extent of collagen-proline hydroxylation, has been studied. A folic acid-free diet containing 10 g sulphasuxidine/kg was used to induce folate deficiency in young male rats. Animals were judged folic acid-deficient on the grounds of retardation of growth, characteristic haematological changes and the urinary excretion of formimino-L-glutamic acid.2. From isotope incorporation studies it was found that folic acid deficiency caused a marked impairment in collagen synthesis. It was shown, however, from the use of pair-fed control animals, that this was due in part to a reduced food intake accompanying the vitamin deficiency. The further reduction in synthesis in addition to that attributable to inanition was considered to arise from an involvement of folic acid in general protein synthesis, since it was found that the synthesis of elastin and non-collagenous skin proteins was similarly impaired.3. Reduced synthesis of collagen was not considered attributable to lack of hydroxylation of peptidyl proline that may occur in ascorbic acid deficiency. Hydroxylation of collagen- and elastin-proline was only very slightly impaired in folic acid deficiency. It was concluded that, at least when ascorbic acid is present, folic acid is not directly essential for the hydroxylation, in vivo, of peptidyl proline. The results support the view that ascorbic acid participates direct, in vivo, in this hydroxylation rather than indirect by simply maintaining an adequate level of reduced folates. They do not, however, exclude the possibility, arising from the known ability of tetrahydrofolate to participate in the hydroxylation of collagen proline in vitro, that when both ascorbate and folate are present, the latter may, in some measure, share in the role of reducing agent in the hydroxylation of peptidyl proline in vivo.

scholarly journals On the variation in the growth of mammalian tissue in vitro according to the age of the animal

1915 ◽  
Vol 88 (606) ◽  
pp. 476-482
Keyword(s):  
Culture Medium ◽  
Embryonic Tissue ◽  
Mammalian Tissue ◽  
Adult Tissue ◽  
Suitable Medium ◽  
Previous Communication ◽  
Series Of Experiments

In a previous communication it was shown that there was considerable variation in the value, as a culture medium, of plasmata taken from different animals of the same species; that these plasmata did not vary as to whether they were homogenous or autogenous, but that some plasmata were good media and some were bad. During this investigation certain evidence arose that this difference might in part be due to the age of the animal. In the present investigation a series of experiments was carried out to show what was the effect, if any, of the age of the animal upon the plasma as culture medium, and upon the tissues as regards the power of growth. Carrel, Burrows, Harrison, and Ingebrigtsen have shown in several papers that embryonic tissue tends to grow more rapidly and more vigorously than adult tissue. There appears to have been, however, no work conducted on the characters of the plasma, although it has been frequently assumed that the plasma of the young or embryonic animals makes a more suitable medium than that of adults; nevertheless it was permissible to believe that the reverse might in fact be true, and that the plasma of young animals is a less suitable medium. It would appear important that this point should be settled, that thereby evidence might be gained as to the controlling influences on the growth of young tissue in vivo .

THE OVARIAN FOLLICLE OF THE SHEEPINHIBITION OF OESTROGEN SECRETION BY LUTEINIZING HORMONE

1974 ◽  
Vol 61 (3) ◽  
pp. 455-463 ◽  
Author(s):  
R. M. MOOR
Keyword(s):  
Luteinizing Hormone ◽  
Organ Culture ◽  
Culture Medium ◽  
Ovarian Follicle ◽  
Corpora Lutea ◽  
In Vitro Techniques ◽  
Progesterone Secretion ◽  
Experimental Approaches

SUMMARY The object of this study was to test the hypothesis that levels of luteinizing hormone (LH), comparable to those circulating at oestrus, inhibit oestrogen secretion from Graafian follicles of sheep. Three experimental approaches were used. Follicles maintained in organ culture secreted high levels of oestrogen into the medium throughout a 7-day culture period; almost no progesterone was secreted under such conditions. By contrast, oestrogen secretion declined precipitously and progesterone secretion increased rapidly after the addition of LH (0·25 μg–10 μg NIH-LH-S 17/ml) to the culture medium. In experiments combining in-vivo and in-vitro techniques, follicles were obtained from sheep from which the corpora lutea had been removed 24 h previously. The large follicles explanted from these sheep secreted high levels of oestrogen throughout the 7 days in culture. Insignificant amounts of oestrogen were, however, secreted in culture by large follicles that had been explanted from sheep in which 1 mg LH had been infused between 18 and 24 h after removal of the corpus luteum. Experiments carried out entirely in vivo showed that intravenous infusion of 1 mg LH into sheep from which the corpora lutea had been removed 18 h previously prevented the ovaries from secreting, during the ensuing 22 h, the large amounts of oestrogen they would otherwise have produced. The results demonstrate that oestrogen secretion by large Graafian follicles is terminated both in vitro and in vivo by an amount of LH corresponding to that released at oestrus.

Superoxide, Xanthine Oxidase and Platelet Reactions: Further Studies on Mechanisms by which Oxidants Influence Platelets

1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Xanthine Oxidase ◽  
Direct Effect ◽  
Platelet Function ◽  
Experimental Conditions ◽  
Release Reaction

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.

Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Platelet Adhesion ◽  
Umbilical Vein ◽  
Procoagulant Activity ◽  
Experimental Conditions ◽  
Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

Reprogrammed M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 extends lifespan of mice with experimental carcinoma

2017 ◽  
pp. 4-9
Author(s):  
С.В. Калиш ◽  
С.В. Лямина ◽  
А.А. Раецкая ◽  
И.Ю. Малышев
Keyword(s):  
Tumor Growth ◽  
Culture Medium ◽  
Ehrlich Carcinoma ◽  
Macrophage Phenotype ◽  
M1 Macrophages ◽  
M1 Macrophage ◽  
Ec Cells ◽  
Experimental Carcinoma

Цель исследования. Репрограммирование М1 фенотипа макрофагов с ингибированными факторами транскрипции М2 фенотипа STAT3, STAТ6 и SMAD и оценка их влияния на развитие карциномы Эрлиха (КЭ) in vitro и in vivo. Методика. Рост опухоли иницировали in vitro путем добавления клеток КЭ в среду культивирования RPMI-1640 и in vivo путем внутрибрюшинной инъекции клеток КЭ мышам. Результаты. Установлено, что M1макрофаги и in vitro, и in vivo оказывают выраженный противоопухолевый эффект, который превосходит антиопухолевые эффекты М1, M1, M1 макрофагов и цисплатина. Заключение. М1 макрофаги с ингибированными STAT3, STAT6 и/или SMAD3 эффективно ограничивают рост опухоли. Полученные данные обосновывают разработку новой технологии противоопухолевой клеточной терапии. Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo . Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1 macrophages have a pronounced anti-tumor effect in vitro , and in vivo , which was greater than anti-tumor effects of M1, M1, M1 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.

Applicability of Instability Index for In vitro Protein Stability Prediction

2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell
Keyword(s):  
Protein Stability ◽  
Caulobacter Crescentus ◽  
Effect Of Temperature ◽  
Instability Index ◽  
Dipeptide Composition ◽  
Experimental Conditions ◽  
The Stability ◽  
Vitro Protein

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.

Differentiation of mesenchymal stem cells from humans and animals into insulin-producing cells: An overview in vitro induction forms

2020 ◽  
Vol 16 ◽  
Author(s):  
Bruna O. S. Câmara ◽  
Bruno M. Bertassoli ◽  
Natália M. Ocarino ◽  
Rogéria Serakides
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Culture Medium ◽  
Adipogenic Differentiation ◽  
Medium Composition ◽  
Cell Therapies ◽  
Insulin Producing Cells ◽  
Msc Differentiation

The use of stem cells in cell therapies has shown promising results in the treatment of several diseases, including diabetes mellitus, in both humans and animals. Mesenchymal stem cells (MSCs) can be isolated from various locations, including bone marrow, adipose tissues, synovia, muscles, dental pulp, umbilical cords, and the placenta. In vitro, by manipulating the composition of the culture medium or transfection, MSCs can differentiate into several cell lineages, including insulin-producing cells (IPCs). Unlike osteogenic, chondrogenic, and adipogenic differentiation, for which the culture medium and time are similar between studies, studies involving the induction of MSC differentiation in IPCs differ greatly. This divergence is usually evident in relation to the differentiation technique used, the composition of the culture medium, the cultivation time, which can vary from a few hours to several months, and the number of steps to complete differentiation. However, although there is no “gold standard” differentiation medium composition, most prominent studies mention the use of nicotinamide, exedin-4, ß-mercaptoethanol, fibroblast growth factor b (FGFb), and glucose in the culture medium to promote the differentiation of MSCs into IPCs. Therefore, the purpose of this review is to investigate the stages of MSC differentiation into IPCs both in vivo and in vitro, as well as address differentiation techniques and molecular actions and mechanisms by which some substances, such as nicotinamide, exedin-4, ßmercaptoethanol, FGFb, and glucose, participate in the differentiation process.

Sign in / Sign up

Export Citation Format

Share Document