Cell permeability as a rate limiting factor in the microbial reduction of sulfonated azo dyes

1982 ◽  
Vol 15 (2) ◽  
pp. 123-126 ◽  
Author(s):  
K. Mechsner ◽  
K. Wuhrmann
Keyword(s):  
Azo Dyes ◽  
Microbial Reduction ◽  
Cell Permeability ◽  
Limiting Factor ◽  
Rate Limiting ◽  
Sulfonated Azo Dyes

Chick embryo heart as a tool for studying cell permeability and insulin action

1961 ◽  
Vol 201 (5) ◽  
pp. 863-868 ◽  
Author(s):  
Guido Guidotti ◽  
Doris Kanameishi ◽  
Piero P. Foà
Keyword(s):  
Chick Embryo ◽  
Glucose Uptake ◽  
Cell Permeability ◽  
Limiting Factor ◽  
Anaerobic Conditions ◽  
Embryologic Development ◽  
Chick Embryo Heart ◽  
Embryo Heart ◽  
Rate Limiting ◽  
Aerobic And Anaerobic

Glucose uptake by chick embryo hearts at various stages of development was measured in aerobic and anaerobic conditions, with or without the addition of insulin. Glucose uptake per gram of tissue decreases as the age of the embryo increases. Increasing the concentration of glucose in the medium causes an increase in uptake by 5-, 7- and 9-day-old hearts; a plateau is reached only with 5-day-old hearts. Anoxia stimulates glucose uptake at all ages studied; insulin has no effect in 5-day-old hearts, but stimulates glucose uptake in hearts 7 days old or older. The results of these experiments suggest the following conclusions: 1) The 5-day-old chick embryo heart is permeable to glucose and, in this preparation, glucose uptake is limited by the rate of intracellular phosphorylation. 2) During the 7th day of embryologic development, coincident with the first production of beta granules in the pancreas of the embryo, an insulin-sensitive "membrane" regulating glucose uptake begins to develop. In 7-day-old and older hearts, glucose transport becomes the rate-limiting factor of glucose uptake. 3) These and other properties of the chick embryo heart make it a convenient tool for the study of permeability and transport phenomena.

Freezing in Silicon at Large Undercooling

1989 ◽  
Vol 157 ◽  
Author(s):  
P.A. Stolk ◽  
A. Polman ◽  
W.C. Sinke
Keyword(s):  
Interface Temperature ◽  
Limiting Factor ◽  
Time Resolved ◽  
Large Undercooling ◽  
Explosive Crystallization ◽  
Crystallization Speed ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Rate Limiting

ABSTRACTPulsed laser irradiation is used to induce epitaxial explosive crystallization of amorphous silicon layers buried in a (100) oriented crystalline matrix. This process is mediated by a self-propagating liquid layer. Time-resolved determination of the crystallization speed combined with numerical calculation of the interface temperature shows that freezing in silicon saturates at 16 m/s for large undercooling (> 130 K). A comparison between data and different models for melting and freezing indicates that the crystallization behavior at large undercooling can be described correctly if the rate-limiting factor is assumed to be diffusion in liquid Si at the solid/liquid interface.

scholarly journals Recognized and Emerging Features of Erythropoietic and X-Linked Protoporphyria

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 151
Author(s):  
Elena Di Pierro ◽  
Francesca Granata ◽  
Michele De Canio ◽  
Mariateresa Rossi ◽  
Andrea Ricci ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Aminolevulinic Acid ◽  
Protoporphyrin Ix ◽  
Limiting Factor ◽  
Zinc Protoporphyrin ◽  
Complete Understanding ◽  
Inherited Disorders ◽  
Rate Limiting ◽  
Systemic Accumulation ◽  
Made In

Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are inherited disorders resulting from defects in two different enzymes of the heme biosynthetic pathway, i.e., ferrochelatase (FECH) and delta-aminolevulinic acid synthase-2 (ALAS2), respectively. The ubiquitous FECH catalyzes the insertion of iron into the protoporphyrin ring to generate the final product, heme. After hemoglobinization, FECH can utilize other metals like zinc to bind the remainder of the protoporphyrin molecules, leading to the formation of zinc protoporphyrin. Therefore, FECH deficiency in EPP limits the formation of both heme and zinc protoporphyrin molecules. The erythroid-specific ALAS2 catalyses the synthesis of delta-aminolevulinic acid (ALA), from the union of glycine and succinyl-coenzyme A, in the first step of the pathway in the erythron. In XLP, ALAS2 activity increases, resulting in the amplified formation of ALA, and iron becomes the rate-limiting factor for heme synthesis in the erythroid tissue. Both EPP and XLP lead to the systemic accumulation of protoporphyrin IX (PPIX) in blood, erythrocytes, and tissues causing the major symptom of cutaneous photosensitivity and several other less recognized signs that need to be considered. Although significant advances have been made in our understanding of EPP and XLP in recent years, a complete understanding of the factors governing the variability in clinical expression and the severity (progression) of the disease remains elusive. The present review provides an overview of both well-established facts and the latest findings regarding these rare diseases.

scholarly journals Neutrophil Extracellular Traps-DNase Balance and Autoimmunity

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2667
Author(s):  
Andrea Angeletti ◽  
Stefano Volpi ◽  
Maurizio Bruschi ◽  
Francesca Lugani ◽  
Augusto Vaglio ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Causative Factor ◽  
Neutrophil Extracellular Traps ◽  
Limiting Factor ◽  
Systemic Lupus ◽  
Extracellular Traps ◽  
Number Of Patients ◽  
Selective Depletion ◽  
Dna Antibodies ◽  
Rate Limiting

Neutrophil extracellular traps (NETs) are macromolecular structures programmed to trap circulating bacteria and viruses. The accumulation of NETs in the circulation correlates with the formation of anti-double-stranded (ds) DNA antibodies and is considered a causative factor for systemic lupus erythematosus (SLE). The digestion of DNA by DNase1 and DNases1L3 is the rate- limiting factor for NET accumulation. Mutations occurring in one of these two DNASE genes determine anti-DNA formation and are associated with severe Lupus-like syndromes and lupus nephritis (LN). A second mechanism that may lead to DNase functional impairment is the presence of circulating DNase inhibitors in patients with low DNase activity, or the generation of anti-DNase antibodies. This phenomenon has been described in a relevant number of patients with SLE and may represent an important mechanism determining autoimmunity flares. On the basis of the reviewed studies, it is tempting to suppose that the blockade or selective depletion of anti-DNase autoantibodies could represent a potential novel therapeutic approach to prevent or halt SLE and LN. In general, strategies aimed at reducing NET formation might have a similar impact on the progression of SLE and LN.

scholarly journals Glypican-1 drives unconventional secretion of Fibroblast Growth Factor 2

2021 ◽  
Author(s):  
Carola Sparn ◽  
Eleni Dimou ◽  
Annalena Meyer ◽  
Roberto Saleppico ◽  
Sabine Wegehingel ◽  
...  
Keyword(s):  
Growth Factor ◽  
Heparan Sulfate ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Structural Basis ◽  
Limiting Factor ◽  
Fibroblast Growth ◽  
Unconventional Secretion ◽  
Rate Limiting

Fibroblast Growth Factor 2 (FGF2) is a tumor cell survival factor that is transported into the extracellular space by an unconventional secretory mechanism. Cell surface heparan sulfate proteoglycans are known to play an essential role in this process. Unexpectedly, we found that among the diverse sub-classes consisting of syndecans, perlecans, glypicans and others, Glypican-1 (GPC1) is both the principle and rate-limiting factor that drives unconventional secretion of FGF2. By contrast, we demonstrate GPC1 to be dispensable for FGF2 signaling into cells. We provide first insights into the structural basis for GPC1-dependent FGF2 secretion, identifying disaccharides with N-linked sulfate groups to be enriched in the heparan sulfate chains of GPC1 to which FGF2 binds with high affinity. Our findings have broad implications for the role of GPC1 as a key molecule in tumor progression.

Availability of Cosubstrates as a Rate-Limiting Factor

2020 ◽  
pp. 119-178
Author(s):  
Gerard J. Mulder ◽  
Klaas R. Krijgsheld
Keyword(s):  
Limiting Factor ◽  
Rate Limiting

scholarly journals Dependence upon Bile Volume of the Biliary Excretion of Bromocresol Green and Amaranth in the Anaesthetized Rat

1975 ◽  
Vol 28 (4) ◽  
pp. 339 ◽  
Author(s):  
Alan G Clark ◽  
KarI M Rogers
Keyword(s):  
Biliary Excretion ◽  
Biliary Tree ◽  
Bulk Flow ◽  
Rate Equations ◽  
Bromocresol Green ◽  
Limiting Factor ◽  
Cumulative Volume ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Anaesthetized Rat

The kinetics of the biliary excretion of both bromocresol green and amaranth are better described in terms of rate equations that are functions of the cumulative volume of bile excreted rather than of time. The rate of disappearance of bromocresol green from the liver also appears to depend on the volume of bile excreted rather than on time. It is proposed that bromocresol green, and probably also amaranth, rapidly equilibrates between the hepatic and biliary compartments as a result of reabsorption from the biliary tree and that the rate-limiting factor in the biliary excretion of these dyes is the removal of dye from the biliary tree by bulk flow.

Molecular evolution of autophagy rate-limiting factor LAMP2 in placental mammals

Gene ◽  
2020 ◽  
Vol 727 ◽  
pp. 144231
Author(s):  
Zahra Jalali ◽  
Najmeh Parvaz
Keyword(s):  
Molecular Evolution ◽  
Limiting Factor ◽  
Rate Limiting
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