The chemistry of pyrrolic compounds. XLVII. The synthesis of a possible biogenetic precursor of haem a and its relationship to the prosthetic group ofmyeloperoxidase and to cryptoporphyrin a

1981 ◽  
Vol 34 (4) ◽  
pp. 871 ◽  
Author(s):  
PS Clezy ◽  
CJR Fookes
Keyword(s):  
Dimethyl Ester ◽  
Prosthetic Group ◽  
Biogenetic Precursor

The synthesis of 18-demethyl-18-formylprotoporphyrin dimethyl ester is described and the role of this compound as an intermediate in the biosynthesis of haem a is considered. A possible relationship between a compound of this structure and the prosthetic group of myeloperoxidase is discussed. The cryptoporphyrin a fraction of ox heart extracts has been reexamined and shown to consist of a mixture of Spirographis porphyrin and its isomer which presumably arise from the in vitro oxidation of the vinyl groups in protoporphyrin.

scholarly journals Acetyl-Coenzyme A carboxylase. Role of the prosthetic group in enzyme polymerization

1975 ◽  
Vol 145 (3) ◽  
pp. 545-548 ◽  
Author(s):  
A D Landman ◽  
K Darkshinamurti
Keyword(s):  
Adipose Tissue ◽  
Enzyme Activation ◽  
Acetyl Coa Carboxylase ◽  
Prosthetic Group ◽  
Polymeric Form ◽  
Acetyl Coenzyme A ◽  
Rat Adipose Tissue ◽  
Acetyl Coenzyme A Carboxylase

Apo-(acetyl-CoA carboxylase) completely free from the holoenzyme was prepared from biotin-deficient rat adipose tissue by using affinity chromatography. The apoenzyme does not aggregate under conditions favouring the transition of the holoenzyme to the polymeric form. Such transition is possible after the conversion of the apoenzyme into the holoenzyme in vitro, thus demonstrating the requirement of the prosthetic biotinyl group for enzyme activation.

scholarly journals Pterostilbene 4′-β-Glucoside Protects against DSS-Induced Colitis via Induction of Tristetraprolin

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Yingqing Chen ◽  
Jeongmin Park ◽  
Yeonsoo Joe ◽  
Hyeok-Jun Park ◽  
Seung-Joo Jekal ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Dimethyl Ester ◽  
Untranslated Regions ◽  
Colon Tissue ◽  
Proinflammatory Mediators ◽  
Antioxidative Effects ◽  
Anti Inflammatory

Pterostilbene, a dimethyl ester analog of resveratrol, has anti-inflammatory and antioxidative effects and alters cell proliferation. Tristetraprolin (TTP) promotes the degradation of proinflammatory mediators via binding to adenosine and uridine- (AU-) rich elements (ARE) located in the 3′-untranslated regions of mRNAs. Here, we utilized pterostilbene 4′-β-glucoside (4-PG), a compound derived from pterostilbene, to investigate whether it has anti-inflammatory effects on dextran sulfate sodium- (DSS-) induced colitis via TTP enhancement. TTP expression was increased in 4-PG dose- and time-dependent manners in RAW264.7 cells. The production of proinflammatory cytokine, such as TNF-α, was reduced by 4-PG in vitro. To investigate the role of TTP in the anti-inflammatory effects of 4-PG, we used DSS-induced colitis in TTP WT and KO mice as models. The expression levels of TTP and proinflammatory cytokines were determined in serum and colon tissue. 4-PG increased the expression of TTP while suppressing proinflammatory cytokines both in vitro and in vivo. These findings suggest that treatment with 4-PG mediates the anti-inflammatory effects of 4-PG on DSS-induced colitis via enhancing TTP expression.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

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