Normal incorporation rates for precursors of collagen and mucopolysaccharide during expression of micromelia induced by 6-aminonicotinamide

Development ◽  
1974 ◽  
Vol 31 (2) ◽  
pp. 305-312
Author(s):  
Robert E. Seegmiller ◽  
Meredith N. Runner
Keyword(s):  
Core Protein ◽  
Limb Bud ◽  
Matrix Proteins ◽  
Synthesis Rate ◽  
Control Groups ◽  
In Ovo ◽  
Limb Buds ◽  
Radioactive Precursor ◽  
Hind Limbs ◽  
And Control

Further delineation of mechanisms by which 6-aminonicotinamide (6-AN) induces micromelia in the chick embryo was investigated by studies on rates of incorporation of thymidine, proline, glucosamine and sulfate as precursors to DNA, collagen and mucopolysaccharide, respectively. Twenty-four hours after in ovo administration of the vitamin antagonist, 6-AN, to day-4 chick embryos, hind limbs from experimental and control groups were excised and incubated for 1 h in medium containing 3 × 10−6m radioactive precursor. Molar incorporation of precursors into the TCA-precipitable fraction showed, in isolated limb buds, (a) that 6-AN enhanced incorporation of thymidine, (b) that 6-AN inhibited utilization of sulfate, and (c) that 6-AN did not significantly alter utilization of glucosamine and proline. Rates of incorporation of thymidine, glucosamine and proline indicate that 6-AN is not cytotoxic to the isolated limb bud. Enhanced incorporation of thymidine suggests expression of compensatory change 24 h after initial effects of 6-AN on DNA synthesis. Rate of incorporation of proline suggests that, under the influence of 6-AN, tropocollagen was synthesized in normal quantities by limb cells. Similarly, rate of incorporation of glucosamine suggests that under the influence of 6-AN normal amounts of hexosamine sugars were being attached to the nascent core-protein of chondroitin. Inhibition of sulfation and failure to complete the chondroitin sulfate molecule seem to account for 6-AN-induced micromelia. This suggests that sulfation depends upon specific NAD-dependent dehydrogenase reactions. As far as can be established by rates of incorporation of labeled precursors, 5-day limb buds, at 24 h after exposure to teratogenic levels of 6-AN, synthesize matrix proteins and hexosamine polysaccharides at normal rates.

scholarly journals Abnormal synthesis of cartilage-characteristic proteoglycan in azaserine-induced micromelial limbs

1989 ◽  
Vol 261 (2) ◽  
pp. 627-635 ◽  
Author(s):  
A Honda ◽  
I Tsuboi ◽  
K Kimata ◽  
Y Hirabayashi ◽  
K Yamada ◽  
...  
Keyword(s):  
Core Protein ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Immunological Methods ◽  
Chick Embryos ◽  
In Ovo ◽  
Hind Limbs ◽  
Limb Morphogenesis ◽  
Indirect Immunofluorescence Technique ◽  
Chain Synthesis

Administration of azaserine (250 micrograms) to day-4 chick embryos in ovo was shown to induce micromelial limbs. In the present study, biosynthesis of cartilage-characteristic proteoglycan H (PG-H) as an index of limb chondrogenesis was examined in normal and micromelial hind limbs from day-7 chick embryos by biochemical and immunological methods. (1) Metabolic labelling of the micromelial limbs with [6-3H]-glucose and [35S]sulphate, followed by analysis of labelled proteoglycans by glycerol-density-gradient centrifugation under dissociative conditions, showed a marked reduction in PG-H synthesis. (2) PG-H synthesized by micromelial limbs differed from that synthesized by normal limbs in possessing a slower sedimenting velocity and much lower amounts of chondroitin sulphates. (3) The amount of PG-H core protein in micromelial limbs was significantly decreased to about 19% on a per limb basis and about 42% on a per DNA basis of that in normal limbs, as determined by e.l.i.s.a. (4) The transition from PG-M to PG-H during limb formation was retarded in micromelial limbs as judged by an indirect immunofluorescence technique using antibodies against PG-M and PG-H. (5) The deficiency of incorporation of labelled glucose into chondroitin sulphate chains of PG-H in micromelial limbs was partially restored by using [6-3H]-glucosamine as a precursor, suggesting that the synthesis of UDP-N-acetylhexosamine, required for chondroitin sulphate chain synthesis of PG-H in micromelial limbs, was decreased. These results suggest that the reduction in the synthesis of PG-H as well as the production of an abnormal form of PG-H during a critical period of limb morphogenesis may be important factors in explaining the micromelia induced by azaserine.

Ultrastructural Features of Defective in Vitro Keratinization of Chick Embryonic Skin

1970 ◽  
Vol 6 (2) ◽  
pp. 485-509
Author(s):  
H. M. JENSEN ◽  
N. K. MOTTET
Keyword(s):  
Hind Limb ◽  
Epidermal Differentiation ◽  
Limb Bud ◽  
Basal Cells ◽  
In Ovo ◽  
Electron Microscopic ◽  
Embryonic Skin ◽  
And Control ◽  
Chick Embryonic Skin

Thirty-four explants of epithelium and subjacent mesenchyme from the hind limb buds of 5-day chick embryos were cultured for 1 to 14 days. Controls consisted of a series of in ovo limb bud specimens from 5 day's incubation to hatching. Both experimental and control specimens were examined by similar electron-microscopic methods. Differentiation of epidermis was precocious and that of dermis extremely retarded in vitro, contrasting with the events in ovo where epidermal differentiation occurred later and differentiation of dermis was early and vigorous. The two types of epidermal cells developed to a different degree in vitro. Pericytes and their derivatives at times developed precociously and reached full maturity, although their pattern of differentiation was asynchronous compared with that in ovo. Basal cells and their derivatives produced filaments precociously but mature keratinized cells were not found. Absence of keratohyaline granules in the epithelial cells appeared to be the initial defect in the keratinization process. Hyperplasia of mitochondria in basal and parabasal cells was also noted. The underlying mesenchyme, which in ovo begins to produce large amounts of collagen at an exponentially accelerating rate at 5 days, synthesized only scant collagen under the in vitro conditions employed. The hypothesis is presented that the mesenchyme alters epithelial differentiation by affecting keratohyaline synthesis which in turn controls keratinization.

scholarly journals Effect of combined therapeutical methods on healing of intrabony defects in regenerative periodontal surgery

2009 ◽  
Vol 150 (11) ◽  
pp. 517-522 ◽  
Author(s):  
Ferenc Dőri
Keyword(s):  
Platelet Rich Plasma ◽  
Matrix Proteins ◽  
Clinical Variable ◽  
Enamel Matrix ◽  
Control Groups ◽  
Intrabony Defects ◽  
Enamel Matrix Proteins ◽  
Pocket Depth ◽  
Periodontal Tissues ◽  
And Control

Several methods are available to enhance the healing and regeneration of periodontal tissues after surgical therapy of intrabony defects. The main indications for the use of combined regenerative procedures are the extent and morphology of the osseous lesions. The six studies of the present dissertation focused on the clinical effect of different barrier techniques, bone substitutes, enamel matrix derivatives and a growth factors containing adjuvant used in various combinations on the healing of severe periodontal intrabony impairments. Synthetic, xenogenetic and autologous materials were used in these randomized clinical studies. Mechanical barriers (polytetrafluoroethylene and collagen membranes) for GTR, biological barriers/enamel matrix proteins (EMD), synthetic (β-TCP) and xenogeneic (NBM) bone grafts and autologous platelet-rich plasma (PRP) were combined in the test and control groups of the trials. The main clinical variable was the clinical attachment level (CAL) and the subsidiary one was the probing pocket depth (PPD), estimated at baseline and after one year. The summation of the results after the statistical analysis takes cognizance of the followings: a) Each of the eleven regenerative methods evaluated (ten combined procedures) leads to significant CAL gain and PPD decrease. b) Using β-TCP or NBM with EMD or with PRP + GTR and GTR’s, the difference between the parameters of the test and control groups were not statistically significant. c) It was confirmed in four studies that the addition of PRP to graft materials has not increased significantly the positive outcomes independent of the type of barrier or graft. d) Adding platelet-rich plasma to natural bone mineral, no benefit was observed from the point of view of the clinical variables. e) The polypeptide proteins of the platelet-rich plasma do not enhance the clinical regenerative effect of enamel matrix proteins. In conclusion, the option of the periodontal surgeons between these methods depends mainly on the defect morphology, the patient’s approach to the different types of materials, the medical concept of the physician, the technical possibilities and the clinical experience of the periodontist.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

Conjugated Linoleic Acid Causes a Marked Increase in Liver α-Tocopherol and Liver α-Tocopherol Transfer Protein in C57BL/6 J Mice

2010 ◽  
Vol 80 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pei-Min Chao ◽  
Wan-Hsuan Chen ◽  
Chun-Huei Liao ◽  
Huey-Mei Shaw
Keyword(s):  
Antioxidant Enzymes ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Thiobarbituric Acid ◽  
Control Group ◽  
Thiobarbituric Acid Reactive Substances ◽  
Control Groups ◽  
Protein Levels ◽  
Transfer Protein ◽  
And Control

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.

The Prospects and Risks Connected with Increasing the Level of Self-Organisation in Students

2020 ◽  
pp. 75-81
Author(s):  
Svetlana Alexandrovna Kosareva ◽  
Keyword(s):  
Higher Education ◽  
Professional Competence ◽  
Initial Level ◽  
Education Institution ◽  
Diagnostic Methods ◽  
Study Guide ◽  
Learning Approaches ◽  
Control Groups ◽  
Self Organisation ◽  
And Control

The paper describes the method for increasing the level of self-organisation in students which has been developed by the author. It also contains the method testing results and presents the prospects and risks teachers could face while applying the method in a higher education institution. The purpose of this study is to find out the prospects and risks of applying the method for increasing the level of self-organisation in students and to determine the ways of reducing the risks. Methodology. The author points out the learning approaches which were the basis of developing the method and describes diagnostic methods for determining students’ self-organisation levels. The work focused on increasing each student’s initial level consists of a theoretical and a practical part and includes project activities on creating a study guide. The results of the study. The method developed proved to be effective. It was established by diagnosing the final level of self-organisation in students in the experimental and control groups. The paper considers the advantages of the method among which there is universal character, flexibility, improvements to teacher’s and students’ professional competence, etc. At the same time it is necessary to be aware of the risks due to the increased amount of teacher’s work and the fact that students’ work within the project tends to be monotonous. In conclusion, the prospects of the method for increasing the level of self-organisation in students are related to its advantages and the final results of the work. The risks of its use can be reduced with the help of the measures proposed in the paper.

Sri Lankan Cleft Lip and Palate Study Model Analysis: Clefts of the Secondary Palate

1993 ◽  
Vol 30 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Andrew Mccance ◽  
David Roberts-Harry ◽  
Martyn Sherriff ◽  
Michael Mars ◽  
William J.B. Houston
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Model Analysis ◽  
Control Group ◽  
Tooth Size ◽  
Sri Lankan ◽  
Control Groups ◽  
Secondary Palate ◽  
Comparable Control ◽  
And Control

The study models of a group of adult Sri Lankan patients with clefts of the secondary palate were investigated. Tooth-size and arch-dimension comparisons were made with a comparable control group. Significant differences were found between the cleft and control groups in tooth sizes, chord lengths, and arch widths. The cleft group dimensions were generally smaller than those of the control group. Overjets were larger in the cleft group.

THE EFFECT OF APPLYING ANIMAL CARTOON PICTURES ON STUDENTS’ ACHIEVEMENT IN WRITING NARRATIVE TEXT

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Hasanul Arifin Zul And Masitowarni Siregar
Keyword(s):  
T Test ◽  
Narrative Text ◽  
Control Group ◽  
First Year ◽  
Writing Achievement ◽  
Control Groups ◽  
Post Test ◽  
Written Test ◽  
And Control ◽  
Experimental Group

This thesis is focused on the investigation of the effect of applying animal cartoon pictures on students’ achievement in writing narrative text. This study aims to find whether applying animal cartoon pictures significantly affect the students’ writing achievement or not. The data in this study were obtained by administering a written test. The population was the 2015/2016 first year (grade XI) of SMA Swasta Nusantara Lubuk Pakam and 66 students were taken as the sample by using random sampling. The sample was divided into two groups, experimental and control groups. The experimental group was taught by applying animal cartoon pictures while the control group without animal cartoon pictures (x = lecturing). The data were taken the scores from the pre-test and post-test to both experimental and control groups. These data were analyzed by using t-test. The result of computing the t-test obviously showed that t-observed is higher than t-table (5.21 >1,67) with the degree of freedom 64 (df =N-2) at the level significance 0,05 one tail test. It showed that the application of animal cartoon pictures significantly affected the students of SMA Swasta Nusantara Lubuk Pakam achievement in writing narrative text.

THE EFFECT OF APPLYING DEMONSTRATION METHOD ON STUDENTS’ ACHIEVEMENT IN SPEAKING SKILL AT THE THIRD GRADE OF SMK PAB 3 MEDAN ESTATE

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Meryanti Napitupulu And Anni Holila Pulungan
Keyword(s):  
High School ◽  
Control Group ◽  
Vocational High School ◽  
Control Groups ◽  
Speaking Test ◽  
The Third ◽  
Speaking Skill ◽  
The Subject ◽  
And Control ◽  
Experimental Group

This study was conducted as an attempt to discover the effect of applying Demonstration Method on students’ achievement in speaking skill. It was an experimental research. The subject was students of Grade XII, Vocational High School (Sekolah Menengah Kejuruan: SMK), which consisted of 79 students. The research was divided into two groups: experimental and control groups. The instrument used to collect the data was speaking test. To obtain the reliability of the test, the writer applied Kuder Richardson 21 formula. The result of the reliability was 0.7, and it was found that the test was reliable. The data were analyzed by using t-test formula. The analysis showed that the scores of the students in the experimental group were significantly higher than the scores of the students in the control group at the level of significant m = 0.05 with the degree of freedom (df) 77, t-observed value 8.9 > t-table value 1.99. The findings indicate that using Demonstration Method significantly affected the students’ achievement in speaking skill. So, English teachers are suggested to use Demonstration Method in order to improve students’ achievement in speaking skill.

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