Macromolecular contaminants

Gimenez-Gallego, G. Rivas, L. and Ramifrez, J.M. 1985. Macromolecular contaminants in preparations of native and proteolyzed Rhodospirillum rubram reaction centers. Physiol. Veg., 23, 571-581. 

Walsh WE, Markowitz H, Jones JD, Gleich GJ (1971) Macromolecular contaminants in penicillin and cephalosporin antibiotics. J Allergy 47 159-169 Weidenmuller HL, Ziegler W (1970) On the proteinaceous impurity of penicillin. Arzneim Forsch 20 585-586... 

Anaphylactoid reactions to sugars, amino acids, and fat emulsions are rare. With regard to sugars, the causal role of macromolecular contaminants in eliciting such reactions has been demonstrated in some cases. No anaphylactic shock due to amino acid mixtures has apparently been reported in the literature, but flush and urticaria may occur occasionally. For fat emulsions adverse reactions are dependent on their composition. Some emulsifiers may give rise to antibody formation and subsequently be responsible for development of allergic reactions. 

Results strongly indicate a causal role for macromolecular contaminants as elicitors of anaphylactoid reactions to invertose solutions (Richter et al. 1976). 

Richter AW, Granath K, Ostling G (1976) Anaphylactoid reactions in connection with infusion of invert sugar solutions are due to macromolecular contaminants. Int Arch Allergy Appl Immunol 50 606-612... 

GC requires low molecular weight molecules, and the macromolecular nature of proteinaceous materials (made up of 21 amino acids covalently condensed) means that they are typically too large to be readily identifiable and time consuming pretreatments of the sample are required. In order to free the amino acids, hydrolysis is required. Subsequent steps of purification to eliminate pigment interferences are also often necessary. Consequently sample pretreatments must be carefully carried out to reduce the risk of loss and/or contamination of the sample. 

In this article we propose a homogenized form of the modified convection-diffusion equations to describe contaminant transport in expansive clays char-acaterized by three disparate length scales and two levels of porosity. The microscale consists of macromolecular structures saturated by an electrolye... 

Enfield CG, Bengtsson G. 1988. Macromolecular transport of hydrophobic contaminants in aqueous environments. Groundwater 26 64-70. 

A stable emulsion is considered to be one in which the dispersed droplets retain their initial character and remain uniformly distributed throughout the continuous phase for the desired shelf life. There should be no phase changes or microbial contamination on storage, and the emulsion should maintain elegance with respect to odor, color, and consistency. Instabilities of both chemical and physical origins can occur in emulsion formulations. Chemical instabilities, such as the development of rancidity in natural oils due to oxidation by atmospheric oxygen, the depolymerization of macromolecular emulsifiers by hydrolysis, or... 

Since granulocytes prepared by centrifugation are markedly contaminated with erythrocytes, the ABO compatibility between donor and recipient will be important unless the erythrocytes can be removed before use. Some reactions, particularly allergic and febrile complications, are associated with the presence of macromolecular agents (hydroxyethyl starch, modified gelatin, dextran), used to increase the yield of centrifugal techniques. ABO incompatibility does not alter the in vivo fate of granulocytes (39). 

When proteinoids were heated in buffer at pH 6.2 or 6.8, loss of catalytic activity was observed. The extent of loss ranged from 95 to 11% (Table II). Those proteinoids that initially showed higher levels of activity relative to histidine were the most affected by the heat treatment. After heating, the level of activity was comparable to that of the equivalent amount of histidine, or to that of mineral acid hydrolysates of the polymer. Under similar conditions, a-chymotrypsin was 97% inactivated. The fact that the control tests on L-histidine or A -carbo-benzoxy-L-histidine showed no effect is consistent with the inference that inactivation is due to disruption of a macromolecular conformation. Copolymers prepared from only aspartic acid and histidine were also active on NPA and were inactivated by the heat treatment. The percentages of inactivation ranged from 62 to 19. Polymers prepared and processed under aseptic conditions were both catalytically active and subject to inactivation by heat. These experiments were performed as routine verification that the respective phenomena do not result from the presence, and subsequent denaturation, of contaminating microbial enzymes. 

Macromolecules are intricate physical-chemical systems whose properties vary as a function of environmental influences such as temperature, pH, ionic strength, contaminants, and solvent composition, to name only a few. They are structurally dynamic, often microhetero-geneous, aggregating systems, and they change conformation in the presence of ligands. Superimposed on this is the limited nature of our current understanding of macromolecular crystallization phenomena and the forces that promote and maintain protein and nucleic acid crystals. 

Nevertheless, it is surprising how often one refers to elemental analysis to confirm the presence of a humic or fulvic acid. It is useful in determining whether a brown, macromolecular acidic material is from a coal, soil, marine sediment, or kerogen. It is most useful in characterizing structural trends in a specific environment, such as in sediments or soil profiles. Atomic ratios, especially 0/C ratios, are the simplest way to display elemental composition of humates. They also help one devise hypothetical structures for humates. As a guide in the synthesis of artificial humic substances, they are invaluable. In addition, atomic ratios help the investigator identify nonhumate contaminants. 

Hydrolysis and RUO4 oxidation affected the interactions of the associated substances with the macromolecular organic matter and the alteration of the macromolecular matrix on a very similar mode, despite the different selectivity and reactivity of the degradation agents. The BBr3 treatment affected the incorporation of organic contaminants in a rather different way. 

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