scholarly journals Location of 64K collagen producer chondrocytes in developing chicken embryo tibiae.

1984 ◽  
Vol 4 (6) ◽  
pp. 1163-1168 ◽  
Author(s):  
O Capasso ◽  
G Tajana ◽  
R Cancedda
Keyword(s):  
Molecular Weight ◽  
Developmental Stage ◽  
Bone Tissue ◽  
Chicken Embryo ◽  
Cartilage Matrix ◽  
Low Molecular Weight ◽  
Specific Developmental Stage ◽  
Cell Biol

The synthesis of a new low-molecular-weight collagen by cultured chicken embryo chondrocytes has been recently demonstrated (Capasso et al., Exp. Cell Res. 142:197-206, 1982; Gibson et al., J. Cell Biol. 93:767-774, 1982; Schmid and Conrad, J. Biol. Chem. 257:12444-12450, 1982). In this paper we report results on the location of chondrocytes synthesizing this new collagen (64K collagen) in the developing chicken embryo. The 64K collagen is synthesized in very large amounts by cells concentrated at the diaphysis of 9-day-old and at the epiphysis of 17-day-old embryo tibiae. These regions are characterized by a remodeling of the cartilage matrix leading to the replacement of the cartilage with bone tissue; therefore, this collagen appears to be a marker of a specific developmental stage of chondrocytes. The origin of cells competent for the synthesis of the 64K collagen is also discussed.

Location of 64K collagen producer chondrocytes in developing chicken embryo tibiae

1984 ◽  
Vol 4 (6) ◽  
pp. 1163-1168
Author(s):  
O Capasso ◽  
G Tajana ◽  
R Cancedda
Keyword(s):  
Molecular Weight ◽  
Developmental Stage ◽  
Bone Tissue ◽  
Chicken Embryo ◽  
Cartilage Matrix ◽  
Low Molecular Weight ◽  
Specific Developmental Stage ◽  
Cell Biol

The synthesis of a new low-molecular-weight collagen by cultured chicken embryo chondrocytes has been recently demonstrated (Capasso et al., Exp. Cell Res. 142:197-206, 1982; Gibson et al., J. Cell Biol. 93:767-774, 1982; Schmid and Conrad, J. Biol. Chem. 257:12444-12450, 1982). In this paper we report results on the location of chondrocytes synthesizing this new collagen (64K collagen) in the developing chicken embryo. The 64K collagen is synthesized in very large amounts by cells concentrated at the diaphysis of 9-day-old and at the epiphysis of 17-day-old embryo tibiae. These regions are characterized by a remodeling of the cartilage matrix leading to the replacement of the cartilage with bone tissue; therefore, this collagen appears to be a marker of a specific developmental stage of chondrocytes. The origin of cells competent for the synthesis of the 64K collagen is also discussed.

Iron, lipocalin, and kidney epithelia

2003 ◽  
Vol 285 (1) ◽  
pp. F9-F18 ◽  
Author(s):  
Jun Yang ◽  
Kiyoshi Mori ◽  
Jau Yi Li ◽  
Jonathan Barasch
Keyword(s):  
Gene Expression ◽  
Molecular Weight ◽  
Iron Metabolism ◽  
Iron Transport ◽  
Chemical Signals ◽  
Low Molecular Weight ◽  
Control Of Gene Expression ◽  
Iron Trafficking ◽  
Cell Biol ◽  
Neutrophil Gelatinase

Brilliant new discoveries in the field of iron metabolism have revealed novel transmembrane iron transporters, novel hormones that regulate iron traffic, and iron's control of gene expression. An important role for iron in the embryonic kidney was first identified by Ekblom, who studied transferrin (Landschulz W and Ekblom P. J Biol Chem 260: 15580–15584, 1985; Landschulz W, Thesleff I, and Ekblom P. J Cell Biol 98: 596–601, 1984; Thesleff I, Partanen AM, Landschulz W, Trowbridge IS, and Ekblom P. Differentiation 30: 152– 158, 1985). Nevertheless, how iron traffics to developing organs remains obscure. This review discusses a member of the lipocalin superfamily, 24p3 or neutrophil gelatinase-associated lipocalcin (NGAL), which induces the formation of kidney epithelia. We review the data showing that lipocalins transport low-molecular-weight chemical signals and data indicating that 24p3/NGAL transports iron. We compare 24p3/NGAL to transferrin and a variety of other iron trafficking pathways and suggest specific roles for each in iron transport.

scholarly journals Developmental Stage- and Genotype-Dependent Regulation of Specialized Metabolite Accumulation in Fruit Tissues of Different Citrus Varieties

2019 ◽  
Vol 20 (5) ◽  
pp. 1245 ◽  
Author(s):  
Roya Nadi ◽  
Behrouz Golein ◽  
Aurelio Gómez-Cadenas ◽  
Vicent Arbona
Keyword(s):  
Molecular Weight ◽  
Developmental Stage ◽  
Low Molecular Weight ◽  
Developmental Level ◽  
Metabolite Profiles ◽  
Depletion Rate ◽  
Metabolite Accumulation ◽  
Polymethoxylated Flavones ◽  
Ripe Stage ◽  
Citrus Varieties

Flavor traits in citrus are the result of a blend of low molecular weight metabolites including sugars, acids, flavonoids and limonoids, these latter being mainly responsible for the characteristic bitter flavor in citrus. In this work, the genotype- and developmental stage-dependent accumulation of flavonoids and limonoids is addressed. To fulfill this goal, three models for citrus bitterness: bitter Duncan grapefruit, bittersweet Thomson orange and sweet Wase mandarin were selected from a total of eight different varieties. Compounds were annotated from LC/ESI-QqTOF-MS non-targeted metabolite profiles from albedo and pulp tissues. Results indicated that the specific blend of compounds providing the characteristic flavor trait is genotype-specific and hence under genetic control, but it is also regulated at the developmental level. Metabolite profiles in albedo mirrored those found in pulp, the edible part of the fruit, despite differences in the concentration and accumulation/depletion rates being found. This is particularly relevant for polymethoxylated flavones and glycosylated limonoids that showed a clear partitioning towards albedo and pulp tissues, respectively. Fruit ripening was characterized by a reduction in flavonoids and the accumulation of limonoid glycosides. However, bitter grapefruit showed higher levels of limonin A-ring lactone and naringin in contrast to sweeter orange and mandarin. Data indicated that the accumulation profile was compound class-specific and conserved among the studied varieties despite differing in the respective accumulation and/or depletion rate, leading to different specialized metabolite concentration at the full ripe stage, consistent with the flavor trait output.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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