scholarly journals Morphological and physiological photon flux influence under in vitro culture of apple shoots

2009 ◽  
Vol 52 (5) ◽  
pp. 1091-1098
Author(s):  
Ilisandra Zanandrea ◽  
Marcos Antonio Bacarin ◽  
Eugenia Jacira Bolacel Braga ◽  
Valmor João Bianchi ◽  
José Antonio Peters
Keyword(s):  
In Vitro Culture ◽  
Growth And Development ◽  
Culture Media ◽  
Sucrose Concentration ◽  
The Other ◽  
Photon Flux ◽  
Apple Rootstock ◽  
Other Hand ◽  
Chloroplastic Pigments

The aim of the present study was to evaluate the growth and development of apple rootstock shoots submitted to different photon flux densities (7, 14, 21 and 60 µmol m-2 s-1) and three culture media. The best photon flux for maximizing growth, number of shoots and leaves was 14 µmol m-2 s-1, which also resulted in the highest values of chloroplastic pigments. On the other hand, the highest photon flux (60 µmol m-2 s-1) decreased significantly these parameters. Medium with reduced sucrose concentration did not affect the analyzed parameters, enabling an efficient multiplication of the cultivar with only 1% of sucrose.

Comparaison de différents milieux utilisés en culture d'anthères in vitro chez le Blé tendre

1980 ◽  
Vol 58 (8) ◽  
pp. 997-1000 ◽  
Author(s):  
Jacques De Buyser ◽  
Yves Henry
Keyword(s):  
Culture Media ◽  
The Other ◽  
Other Hand ◽  
Medium Increase ◽  
Extract Medium ◽  
Potato Extract ◽  
Anther Cultures

Three culture media, including one from potato extracts, have been compared. It is shown that glutamine and the potato extract medium increase the frequency of embryos produced from anther cultures. On the other hand, the extract medium is characterized by (1) the earlier formation of embryos; (2) better embryos which most often have meristematic initials; and (3) an increase in the rate of haploids. [Journal translation]

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Peroxidases from Tulip Bulbs (Tulipa fosteriana, L.) Oxidize Xenobiotics NNitrosodimethylamine and N-Nitroso-N-methylaniline in vitro

1997 ◽  
Vol 62 (11) ◽  
pp. 1804-1814 ◽  
Author(s):  
Marie Stiborová ◽  
Hana Hansíková
Keyword(s):  
Cytochromes P450 ◽  
Kinetic Studies ◽  
The Other ◽  
Maximal Velocity ◽  
Michaelis Constant ◽  
Other Hand ◽  
Plant Peroxidases ◽  
Tulip Bulbs

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A1, A2, A3) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A1) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulip peroxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate were determined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.

scholarly journals Fetal erythropoiesis in steel mutant mice. III. Defect in differentiation from BFU-E to CFU-E during early development

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 539-547 ◽  
Author(s):  
DH Chui ◽  
SK Liao ◽  
K Walker
Keyword(s):  
Progenitor Cells ◽  
Early Development ◽  
The Other ◽  
Mutant Mice ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells ◽  
Other Hand ◽  
Colony Forming Units ◽  
Fetal Erythropoiesis

Abstract Erythroid progenitor cells in +/+ and Sl/Sld fetal livers manifested as burst-forming units-erythroid (BFU-E) and colony-forming units- erythroid (CFU-E) were assayed in vitro during early development. The proportion of BFU-E was higher as mutant than in normal fetal livers. On the other hand, the proportion of CFU-E was less in the mutant than in the normal. These results suggest that the defect in Sl/Sld fetal hepatic erythropoiesis is expressed at the steps of differentiation that effect the transition from BFU-E to CFU-E.

scholarly journals Rheological and Microstructural Features of Plant Culture Media Doped with Biopolymers: Influence on the Growth and Physiological Responses of In Vitro-Grown Shoots of Thymus lotocephalus

2021 ◽  
Vol 2 (2) ◽  
pp. 538-553
Author(s):  
Natacha Coelho ◽  
Alexandra Filipe ◽  
Bruno Medronho ◽  
Solange Magalhães ◽  
Carla Vitorino ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Culture Medium ◽  
Culture Media ◽  
Average Pore Size ◽  
Physiological Responses ◽  
Gum Arabic ◽  
Shoot Elongation ◽  
Hydroxyethyl Cellulose ◽  
Plant Culture

In vitro culture is an important biotechnological tool in plant research and an appropriate culture media is a key for a successful plant development under in vitro conditions. The use of natural compounds to improve culture media has been growing and biopolymers are interesting alternatives to synthetic compounds due to their low toxicity, biodegradability, renewability, and availability. In the present study, different culture media containing one biopolymer (chitosan, gum arabic) or a biopolymer derivative [hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC)], at 100 or 1000 mg L−1, were tested regarding their influence on the growth and physiological responses of Thymus lotocephalus in vitro culture. Cellulose-based biopolymers (HEC and CMC) and gum arabic were used for the first time in plant culture media. The results showed that CMC at 100 mg L−1 significantly improved shoot elongation while chitosan, at the highest concentration, was detrimental to T. lotocephalus. Concerning only the evaluated physiological parameters, all tested biopolymers and biopolymer derivatives are safe to plants as there was no evidence of stress-induced changes on T. lotocephalus. The rheological and microstructural features of the culture media were assessed to understand how the biopolymers and biopolymer derivatives added to the culture medium could influence shoot growth. As expected, all media presented a gel-like behaviour with minor differences in the complex viscosity at the beginning of the culture period. Most media showed increased viscosity overtime. The surface area increased with the addition of biopolymers and biopolymer derivatives to the culture media and the average pore size was considerably lower for CMC at 100 mg L−1. The smaller pores of this medium might be related to a more efficient nutrients and water uptake by T. lotocephalus shoots, leading to a significant improvement in shoot elongation. In short, this study demonstrated that the different types of biopolymers and biopolymer derivatives added to culture medium can modify their microstructure and at the right concentrations, are harmless to T. lotocephalus shoots growing in vitro, and that CMC improves shoot length.

scholarly journals THE PATHOLOGIC EFFECTS OF STREPTOCOCCI FROM CASES OF POLIOMYELITIS AND OTHER SOURCES

1917 ◽  
Vol 25 (4) ◽  
pp. 557-580 ◽  
Author(s):  
Carroll G. Bull
Keyword(s):  
Spinal Cord ◽  
Guinea Pigs ◽  
The Other ◽  
Laboratory Animals ◽  
Histological Changes ◽  
Other Hand ◽  
Brain And Spinal Cord ◽  
The Brain

Streptococci cultivated from the tonsils of thirty-two cases of poliomyelitis were used to inoculate various laboratory animals. In no case was a condition induced resembling poliomyelitis clinically or pathologically in guinea pigs, dogs, cats, rabbits, or monkeys. On the other hand, a considerable percentage of the rabbits and a smaller percentage of some of the other animals developed lesions due to streptococci. These lesions consisted of meningitis, meningo-encephalitis, abscess of the brain, arthritis, tenosynovitis, myositis, abscess of the kidney, endocarditis, pericarditis, and neuritis. No distinction in the character or frequency of the lesions could be determined between the streptococci derived from poliomyelitic patients and from other sources. Streptococci isolated from the poliomyelitic brain and spinal cord of monkeys which succumbed to inoculation with the filtered virus failed to induce in monkeys any paralysis or the characteristic histological changes of poliomyelitis. These streptococci are regarded as secondary bacterial invaders of the nervous organs. Monkeys which have recovered from infection with streptococci derived from cases of poliomyelitis are not protected from infection with the filtered virus, and their blood does not neutralize the filtered virus in vitro. We have failed to detect any etiologic or pathologic relationship between streptococci and epidemic poliomyelitis in man or true experimental poliomyelitis in the monkey.

In vitro insulin-mimetic activity and in vivo metallokinetic feature of oxovanadium(IV)porphyrin complexes in healthy rats

2012 ◽  
Vol 16 (01) ◽  
pp. 114-121 ◽  
Author(s):  
Tapan K. Saha ◽  
Yutaka Yoshikawa ◽  
Hirouki Yasui ◽  
Hiromu Sakurai
Keyword(s):  
The Other ◽  
Insulin Mimetic ◽  
Other Hand ◽  
Better Than

We prepared [meso-tetrakis(4-carboxylatophenyl)porphyrinato]oxovanadium(IV) tetrasodium, ([VO(tcpp)]Na4), and investigated its in vitro insulin-mimetic activity and in vivo metallokinetic feature in healthy rats. The results were compared with those of previously proposed insulin-mimetic oxovanadium(IV)porphyrin complexes and oxovanadium(IV) sulphate. The in vitro insulin-mimetic activity and bioavailability of [VO(tcpp)]Na4 were considerably better than those of [meso-tetrakis (1-methylpyridinium-4-yl)porphyrinato]oxovanadium(IV)(4+) tetraperchlorate ([VO(tmpyp)](ClO4)4) and oxovanadium(IV) sulphate. On the other hand, [VO(tcpp)]Na4 and [meso-tetrakis(4-sulfonatophenyl) porphyrinato]oxidovanadate(IV)(4-)([VO(tpps)]) showed very similar in vitro insulin-mimetic activity and in vivo metallokinetic feature in healthy rats. In particular, the order of in vitro insulin-mimetic activity of the complexes was determined to be: [VO(tcpp)]Na4 ≈ [VO(tpps)] > ([VO(tmpyp)](ClO4)4 > oxovanadium(IV) sulphate.

scholarly journals Pancreatic plasma membranes: promiscuous partners in membrane fusion

1994 ◽  
Vol 298 (3) ◽  
pp. 599-604 ◽  
Author(s):  
E G Lee ◽  
S J Marciniak ◽  
C M MacLean ◽  
J M Edwardson
Keyword(s):  
Membrane Fusion ◽  
Plasma Membranes ◽  
Secretory Granules ◽  
The Other ◽  
Zymogen Granules ◽  
Other Hand

We have developed a system in which the fusion of pancreatic plasma membranes with zymogen granules can be studied in vitro. We show here that pancreatic plasma membranes fuse not only with pancreatic zymogen granules but also with parotid secretory granules. In contrast, parotid membranes fuse only with parotid granules and not with pancreatic granules. The extent of fusion is insensitive to Ca2+ for all combinations of plasma membranes and granules. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]), on the other hand, stimulates fusion of pancreatic membranes with both pancreatic granules and parotid granules, but inhibits fusion between parotid membranes and parotid granules.

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