Lens differentiation in vitro in the absence of optic vesicle in the epiblast of chick blastoderm under the influence of skin dermis

Development ◽  
1972 ◽  
Vol 28 (1) ◽  
pp. 117-132
Author(s):  
Takeo Mizuno
Keyword(s):  
Neural Retina ◽  
Cephalic Region ◽  
Optic Vesicle ◽  
Dorsal Skin ◽  
Chick Blastoderm ◽  
Tissue Interactions ◽  
Two Factors ◽  
Recombination Experiments ◽  
Specific Influence

1. Dissociation and recombination experiments in vitro were found useful for analysing inductive tissue interactions involved in lens differentiation in the chick.2. When the presumptive cephalic region (epiblast plus hypoblast) of the embryo at predefinitive streak to one-somite stage is cultivated in vitro combined with the dermis isolated either from the dorsal skin of 6·5-day embryo or from the 13·5-day tarsometatarsal skin, a lens with fibres or lentoid is produced in the epiblast. In no case is there an optic vesicle present in the explant. 3. When the presumptive cephalic region (epiblast plus hypoblast) is cultivated without dermis, the lens is no longer formed. 4. If the epiblast alone, dissociated from the hypoblast of the presumptive cephalic region, is recombined with the dermis of the 6·5-day dorsal skin, lenses or lentoids fail to develop. 5. Cultivation of the epiblast alone cannot cause differentiation of the lens or lentoid. 6. The dermis can be replaced by other mesenchymes or embryonic organs: gizzard mesenchyme, mesonephros, sclerotome, liver and neural retina, though they are less effective than the dermis in producing lenses or lentoids in the epiblast. 7. It may therefore be concluded that the lens is induced in vitro by the actions of at least two factors: the epiblast first becomes competent under the specific influence of the hypoblast of the cephalic region. The lens will then differentiate from the competent epiblast by the non-specific action of various tissues such as the skin dermis, mesonephros, or sclerotome. 8. The primary stage of lens induction (action of the hypoblast on the epiblast) seems not yet completed by streak stage.

FGF1 patterns the optic vesicle by directing the placement of the neural retina domain

Development ◽  
1998 ◽  
Vol 125 (5) ◽  
pp. 869-877 ◽  
Author(s):  
J. Hyer ◽  
T. Mima ◽  
T. Mikawa
Keyword(s):  
Neural Retina ◽  
Expression Vectors ◽  
Expression Data ◽  
Optic Vesicle ◽  
Surface Ectoderm ◽  
Pigmented Epithelium ◽  
Optic Vesicles ◽  
Cell Phenotypes

Patterning of the bipotential retinal primordia (the optic vesicles) into neural retina and retinal pigmented epithelium depends on its interaction with overlaying surface ectoderm. The surface ectoderm expresses FGFs and the optic vesicles express FGF receptors. Previous FGF-expression data and in vitro analyses support the hypothesis that FGF signaling plays a significant role in patterning the optic vesicle. To test this hypothesis in vivo we removed surface ectoderm, a rich source of FGFs. This ablation generated retinas in which neural and pigmented cell phenotypes were co-mingled. Two in vivo protocols were used to replace FGF secretion by surface ectoderm: (1) implantation of FGF-secreting fibroblasts, and (2) injection of replication-incompetent FGF retroviral expression vectors. The retinas in such embryos exhibited segregated neural and pigmented epithelial domains. The neural retina domains were always close to a source of FGF secretion. These results indicate that, in the absense of surface ectoderm, cells of the optic vesicles display both neural and pigmented retinal phenotypes, and that positional cues provided by FGF organize the bipotential optic vesicle into specific neural retina and pigmented epithelium domains. We conclude that FGF can mimic one of the earliest functions of surface ectoderm during eye development, namely the demarcation of neural retina from pigmented epithelium.

3 (2) Factorial Design Assisted Crushed Puffed Rice-HPMC-Chitosan based Hydrodynamically Balanced System of Metoprolol Succinate

2020 ◽  
Vol 10 (3) ◽  
pp. 237-249
Author(s):  
Shashank Soni ◽  
Veerma Ram ◽  
Anurag Verma
Keyword(s):  
Drug Release ◽  
Factorial Design ◽  
Hydroxypropyl Methylcellulose ◽  
Batch Size ◽  
Metoprolol Succinate ◽  
Zero Order Kinetics ◽  
Two Factors ◽  
Puffed Rice ◽  
Model Drug

Introduction: Hydrodynamically balanced system (HBS) possesses prolonged and continuous delivery of the drug to the gastrointestinal tract which improves the rate and extent of medications that have a narrow absorption window. The objective of this work was to develop a Hydrodynamically Balanced System (HBS) of Metoprolol Succinate (MS) as a model drug for sustained stomach specific delivery. Materials and Methods: Experimental batches were designed according to 3(2) Taguchi factorial design. A total of 9 batches were prepared for batch size 100 capsules each. Formulations were prepared by physically blending MS with polymers followed by encapsulation into hard gelatin capsule shell of size 0. Polymers used were Low Molecular Weight Chitosan (LMWCH), Crushed Puffed Rice (CPR), and Hydroxypropyl Methylcellulose K15 M (HPMC K15M). Two factors used were buoyancy time (Y1) and time taken for 60% drug release (T60%; Y2). Results: The drug excipient interaction studies were performed by the thermal analysis method which depicts that no drug excipient interaction occurs. In vitro buoyancy studies and drug release studies revealed the efficacy of HBS to remain gastro retentive for a prolonged period and concurrently sustained the release of MS in highly acidic medium. All formulations followed zero-order kinetics. Conclusion: Developed HBS of MS with hydrogel-forming polymers could be an ideal delivery system for sustained stomach specific delivery and would be useful for the cardiac patients where the prolonged therapeutic action is required.

An in vitro analysis of the organization of the eye-forming area in the early chick blastoderm

1940 ◽  
Vol 85 (2) ◽  
pp. 171-209 ◽  
Author(s):  
Nelson T. Spratt
Keyword(s):  
Chick Blastoderm ◽  
Vitro Analysis ◽  
In Vitro Analysis

Basic fibroblast growth factor induces retinal pigment epithelium to generate neural retina in vitro

Development ◽  
1991 ◽  
Vol 113 (2) ◽  
pp. 577-588 ◽  
Author(s):  
C. Pittack ◽  
M. Jones ◽  
T.A. Reh
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Retinal Pigment ◽  
Neural Retina ◽  
Phenotypic Switching ◽  
Surgical Removal ◽  
Fibroblast Growth ◽  
Neuronal Progenitors

During embryogenesis, the cells of the eye primordium are initially capable of giving rise to either neural retina or pigmented epithelium (PE), but become restricted to one of these potential cell fates. However, following surgical removal of the retina in embryonic chicks and larval amphibians, new neural retina is generated by the transdifferentiation, or phenotypic switching, of PE cells into neuronal progenitors. A recent study has shown that basic fibroblast growth factor (bFGF) stimulates this process in chicks in vivo. To characterize further the mechanisms by which this factor regulates the phenotype of retinal tissues, we added bFGF to enzymatically dissociated chick embryo PE. We found that bFGF stimulated proliferation and caused several morphological changes in the PE, including the loss of pigmentation; however, no transdifferentiation to neuronal phenotypes was observed. By contrast, when small sheets of PE were cultured as aggregates on a shaker device, preventing flattening and spreading on the substratum, we found that a large number of retinal progenitor cells were generated from the PE treated with bFGF. These results indicate that bFGF promotes retinal regeneration in vitro, as well as in ovo, and suggest that the ability of chick PE to undergo transdifferentiation to neuronal progenitors appears to be dependent on the physical configuration of the cells.

scholarly journals Rumen fermentation kinetics as impacted by red amaranth (Amaranthus cruentus, L) leaf powder using in vitro gas production technique

2020 ◽  
Author(s):  
Thiwakorn Ampapon ◽  
Bounnaxay Viennasay ◽  
Metha Wanapat
Keyword(s):  
Rumen Fermentation ◽  
Gas Production ◽  
Amaranthus Cruentus ◽  
Randomized Design ◽  
In Vitro Gas Production ◽  
Two Factors ◽  
Dry Matter Degradation ◽  
Leaf Powder ◽  
Completely Randomized Design

Abstract Background A need for research searching for alternative rumen enhancers warrants immediate attention. The in vitro fermentation experiment was conducted using factorial arrangement of two factors of roughage to concentrate and seven level of red amaranth leaf powder percentage of total substrate in a Completely randomized design (CRD). Two factors, namely Factor A was two ratio of roughage (R) to concentrate (C) at 60:40 and 40:60 and Factor B was level of red amaranth (Amaranthus cruentus, L) leaf powder (RALP) supplementation at 0, 2, 4, 6, 8, 10, and 12% of total dietary substrate. Results Red amaranth leaf powder (RALP) contained phytonutrients both condensed tannins and saponins in addition with high macro minerals (Ca, K, and Mg). This experiment revealed innovations of the RALP supplementation by enhancing rumen propionate (C3) production, reducing acetate (C2) to (C3) ratio, reducing protozoal population and mitigating methane (CH4) production. Furthermore, rumen dry matter degradation percentages were remarkably enhanced (P < 0.001) by increasing RALP supplementation. Conclusion Plants rich in phytonutrients and minerals such as red amaranth leaf powder (RALP) have a vital and promising role in modulating rumen fermentation, mitigating methane production, as well as increasing substrate degradability.

scholarly journals THE ADDITION OF COCONUT WATER AND THIAMINE TOWARDS CHRYSSANTHENUM MICRO CUTTINGS (Dendranthema grandiflora Tzvelev) IN VITRO

Agrivet ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 39
Author(s):  
Salma Nabila ◽  
Endah Budi Irawati ◽  
Rina Srilestari
Keyword(s):  
Water Concentration ◽  
Coconut Water ◽  
Fresh Weight ◽  
Randomized Design ◽  
Two Factors ◽  
Completely Randomized Design ◽  
Range Test ◽  
Growing Shoot

Chryssanthenum is ornamental plant with variety of shape and color which are unique and appealing. So that, it is in great demand in the community. The production of Chrissanthenum conventionally hampered by availability and quality of seeds. Thus, it needs research through tissue culture. The aim of this research is to know interaction between coconut water and thiamine and to determine the best coconut water and thiamine concentration toward Chryssanthenum micro cuttings. This research used laboratory experimental method by using completely randomized design with two factor. The 1st factor was coconut water concentration consisted of three level which were 5%, 10% and 15%. The 2nd factor was thiamine concentration consisted of three level which were 1mg/L, 2 mg/L and 3 mg/L. From the two factors, those were found that, there were nine combination of treatments and repeated 3 times. The variety  of data was analyzed by using Analysis of Variance (ANOVA) with level of α=5%, and continued by examining Duncan’s Multiple Range Test (DMRT) with level of α=5%. The result indicated that the interaction of coconut water concentration was 5% and thiamine was 1 mg/L on the parameters when growing shoot. There was also interaction on coconut water concentration which was 10 % and thiamine was 1 mg/L on the parameters in the number of shoots. interaction of coconut water combination was 15% and thiamine was 2 mg/L on  fresh weight. The addition of 10% coconut water and 1 mg/L thiamine showed the best result on shoot length.

Effect of α-melanocyte-stimulating hormone on tyrosinase activity in hair follicular and epidermal melanocytes of the mouse

1988 ◽  
Vol 119 (3) ◽  
pp. 517-522 ◽  
Author(s):  
P. Seechurn ◽  
S. A. Burchill ◽  
A. J. Thody
Keyword(s):  
Tyrosinase Activity ◽  
In Vitro Experiments ◽  
Dorsal Skin ◽  
Wild Type ◽  
Melanocyte Stimulating Hormone ◽  
Tyrosinase Expression ◽  
In Vivo Administration ◽  
Agouti Gene

ABSTRACT In this study, the effect of α-MSH on tyrosinase activity was compared in epidermal and hair follicular melanocytes of mice. It had no effect on epidermal tyrosinase activity in dorsal skin from neonatal non-agouti black mice (C57BL/6J) in both in-vivo and in-vitro experiments. Theophylline and 8-bromocyclic (c)AMP were similarly without effect in in-vitro experiments. In-vivo administration of α-MSH and theophylline for 7 days was also without effect on epidermal tyrosinase activity in ear skin of adult non-agouti mice, and the same was true for α-MSH in wild-type agouti mice. Activation of the epidermal melanocytes in the non-agouti and wild-type agouti mice with ultraviolet radiation also failed to bring about a response to α-MSH and to theophylline in the case of the former. No tyrosinase activity was detected in the epidermis of viable yellow mice (C3H-HeAvy), but, as shown previously, tyrosinase activity was present in the hair follicle when the hair was actively growing and was increased in those mice given either α-MSH or theophylline. α-MSH and theophylline had no such effects on hair follicular tyrosinase activity in the non-agouti mice. The present results suggest that α-MSH- and cAMP-dependent mechanisms have little or no importance in the regulation of tyrosinase expression in mouse epidermal melanocytes. α-MSH may, however, regulate tyrosinase expression in hair follicular melanocytes, but even in these melanocytes its action may be restricted to mice that express the agouti gene. J. Endocr. (1988) 119, 517–522

scholarly journals The Effect of Processing and Cooling Methods on Coleus tuberosus in vitro Starch Digestibility

2021 ◽  
Vol 41 (3) ◽  
pp. 238
Author(s):  
Jhauharotul Muchlisyiyah ◽  
Tri Dewanti Widyaningsih ◽  
Retno Wulansari ◽  
Hera Sisca Prasmita
Keyword(s):  
Resistant Starch ◽  
Room Temperature ◽  
Potato Starch ◽  
Block Design ◽  
In Vitro Digestibility ◽  
Randomized Block Design ◽  
Two Factors ◽  
Cooling Methods ◽  
Total Starch

Coleus tuberosus, also known as black potato, is one of the Indonesian local tubers consumed as a carbohydrate substituent. Therefore, this study aimed to examine the effect of processing and cooling methods on the in vitro digestibility of black potato starch. Furthermore, two factors Randomized Block Design with a 2x3 experimental design was used, which consisted of processing methods (boiling, roasting, and microwave) and cooling at room temperature and 4 °C for 24 hours with 3 repetitions. Black potato flour was compared with the raw form, by assessing some parameters, namely Resistant Starch (RS), Slowly Digestible Starch (SDS), Rapidly Digestible Starch (RDS), and Glycemic Index (GI). Also, the analysis of total starch, moisture, and color was performed, hence raw black potatoes generally have 10% resistant starch (%wb). Different treatments of cooking and cooling had a significant effect (α = 0.05) on moisture content, total starch, RS, RDS, SDS, GI, brightness (L), and yellowness (b). Black potatoes subjected to the processing method followed by cooling had lower RDS and increased RS content. Furthermore, refrigeration at 4°C for 24 hours reduced the digestibility of black potato starch more than cooling at room temperature. Contrarily, microwaved black potato cooled at room temperature showed a higher digestion rate compared to the raw counterpart. Conclusively, processing followed by cooling reduces the GI and increases the RS content of Coleus tuberosus.

Permissive and directive interactions in lens induction

Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 167-179
Author(s):  
Marketta Karkinen-Jääskeläinen
Keyword(s):  
Culture Conditions ◽  
Chick Embryos ◽  
Optic Vesicle ◽  
Lens Proteins ◽  
Lens Formation

The interactive events leading to lens formation and the developmental potentialities of the presumptive lens ectoderm were examined in vitro. The presumptivelens ectoderm of both mouse and chick embryos was capable of forming a lens even when isolated from the optic vesicle before the two tissues reach the stage of close association.This lens-forming bias can be released with favourable culture conditions and by various heterotypic mesenchymes. The same permissive, unspecific conditions or heterotypic tissues failed to trigger lens formation in trunk ectoderm. The directive effect of the optic vesicle was demonstrated in experiments where it was grown in contact with the trunk ectoderm. The latter developed distinct lentoid bodies synthesizing lens proteins. The origin of the lentoid was confirmed in interspecies combination of chick and quail tissues. Itis concluded that lens formation is governed by a series of interactive events consisting of both directive and permissive influences.

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