Changes in the Distribution of Cadmium and Lead in Human and Bovine Milk Induced by Heating or Freezing

The percentage of cadmium or lead present in the fat fraction of bovine milk is not affected by heating or freezing. In human skimmed milk, cadmium is mainly associated with a fraction with molecular weight lower than 10,000. Storage at −20°C for 10 days does not have any effect on the distribution of cadmium when milk is incubated with this metal before freezing. This treatment causes only a small increase in the amount of cadmium associated with the low molecular weight fraction when the metal is added after freezing. In bovine milk, 64% of cadmium is associated with a fraction with molecular weight above 70,000. Freezing causes a 37% decrease of the cadmium present in this fraction when the metal is added after thawing. When bovine milk was incubated with cadmium before freezing there was not a marked change in its distribution as when added after thawing. Heating at 63°C for 30 min caused a slight decrease in the amount of cadmium present in the casein fraction. The distribution change of cadmium after freezing or heating is probably due to the formation of complexes between the whey proteins and the metal, or to the disaggregation of the cadmium bound to casein micelles. Lead is mainly associated with caseins in bovine and human milk. No significant changes were caused by freezing or heating in the distribution of lead in human and bovine milk.

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The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk

Journal of Dairy Science ◽

10.3168/jds.2015-9461 ◽

2015 ◽

Vol 98 (8) ◽

pp. 5155-5163 ◽

Cited By ~ 13

Author(s):

M. Cheema ◽

M.S. Mohan ◽

S.R. Campagna ◽

J.L. Jurat-Fuentes ◽

F.M. Harte

Keyword(s):

Molecular Weight ◽

Bovine Milk ◽

Low Molecular Weight ◽

Casein Micelles ◽

Hydrophobic Compounds

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Distribution of Added Lead and Cadmium in Human and Bovine Milk

Journal of Food Protection ◽

10.4315/0362-028x-58.3.305 ◽

1995 ◽

Vol 58 (3) ◽

pp. 305-309 ◽

Cited By ~ 5

Author(s):

LUIS MATA ◽

M. DOLORES PEREZ ◽

PILAR PUYOL ◽

MIGUEL CALVO

Keyword(s):

Molecular Weight ◽

Human Milk ◽

Bovine Milk ◽

Gel Filtration ◽

Weight Fraction ◽

Acid Precipitation ◽

Low Molecular Weight ◽

Lead And Cadmium ◽

Skimmed Milk ◽

Enzymatic Coagulation

Distribution of added lead and cadmium to bovine and human milk and whey has been studied. In bovine milk, about 97 and 89% of lead and cadmium, respectively, were recovered in the casein fraction obtained by enzymatic coagulation. However, only 6% of lead and 41% of cadmium were found in the same fraction separated by acid precipitation, indicating that the distribution of both metals is very different depending on the method used for milk fractionation. Moreover, gel filtration of bovine and human skimmed milk and whey after addition of lead and cadmium was carried out. Most of the lead was associated to the casein fraction after gel filtration of skimmed milk, whereas in the chromatography of whey, lead was eluted with the low molecular weight fraction in both species. However, a different pattern in the distribution of cadmium has been observed in the two species studied. In contrast to the binding of cadmium to the low molecular weight fraction in human skimmed milk and whey, it was mainly associated to a component of a molecular weight around 70,000 in bovine skimmed milk. This component was not present in bovine whey indicating that it is separated with casein during fractionation.

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In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653429 ◽

1981 ◽

Vol 46 (03) ◽

pp. 612-616 ◽

Cited By ~ 18

Author(s):

U Schmitz-Huebner ◽

L Balleisen ◽

F Asbeck ◽

J van de Loo

Keyword(s):

Molecular Weight ◽

Day Treatment ◽

Gel Filtration ◽

Weight Fraction ◽

In Vivo Studies ◽

Low Molecular Weight ◽

High Molecular Weight Fraction ◽

Platelet Factor ◽

Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

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Candidate markers for the detection of hepatocellular carcinoma in low-molecular weight fraction of serum

Carcinogenesis ◽

10.1093/carcin/bgm177 ◽

2007 ◽

Vol 28 (10) ◽

pp. 2149-2153 ◽

Cited By ~ 29

Author(s):

Radoslav Goldman ◽

Habtom W. Ressom ◽

Mohamed Abdel-Hamid ◽

Lenka Goldman ◽

Antai Wang ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Molecular Weight ◽

Weight Fraction ◽

Low Molecular Weight

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ChemInform Abstract: The Binding of Metal Ions by Mercaptoacids. Part 2. Formation Constants for the Complexes of Mercaptosuccinate with Cd(II) and Computer Simulation of Its Ability to Mobilize the Low Molecular Weight Fraction of Cd(II) in Blood Plasma.

ChemInform ◽

10.1002/chin.198741077 ◽

1987 ◽

Vol 18 (41) ◽

Author(s):

M. FILELLA ◽

E. CASASSAS ◽

D. R. WILLIAMS

Keyword(s):

Molecular Weight ◽

Computer Simulation ◽

Metal Ions ◽

Blood Plasma ◽

Weight Fraction ◽

Formation Constants ◽

Low Molecular Weight ◽

In Blood Plasma

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Anti-Inflammatory Activity in the Low Molecular Weight Fraction of Commercial Human Serum Albumin (LMWF5A)

Journal of Immunoassay and Immunochemistry ◽

10.1080/15321819.2015.1047516 ◽

2015 ◽

Vol 37 (1) ◽

pp. 55-67 ◽

Cited By ~ 10

Author(s):

Gregory W. Thomas ◽

Leonard T. Rael ◽

Charles W. Mains ◽

Denetta Slone ◽

Matthew M. Carrick ◽

...

Keyword(s):

Molecular Weight ◽

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Weight Fraction ◽

Inflammatory Activity ◽

Low Molecular Weight ◽

Anti Inflammatory

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Characterization of Sol and Gel in Hevea Natural Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3538454 ◽

1997 ◽

Vol 70 (5) ◽

pp. 707-713 ◽

Cited By ~ 60

Author(s):

Jitladda Tangpakdee ◽

Yasukuki Tanaka

Keyword(s):

Molecular Weight ◽

Weight Fraction ◽

Toluene Solution ◽

Low Molecular Weight ◽

Branch Points ◽

Gel Content ◽

High Ammonia ◽

Linear Molecules ◽

Cis And Trans

Abstract The gel content of rubber from high-ammonia latex (HA-latex) decreased significantly after deproteinization with proteolytic enzyme. The addition of 1–2% ethanol in toluene solution reduced the gel content of rubbers from HA-latex, deproteinized HA-latex (HA-DP) and pale crepe. Transesterification of the rubber in toluene solution with sodium methoxide dissolved the gel fraction. The gel fractions solubilized after transesterification showed molecular weight distribution rich in low molecular-weight fraction. The Huggins k′ constant of the fractionated rubbers from solubilized-gels was in the range of 0.42–0.45, lower than that of the fractionated HA-DP of 0.5–0.8. This indicates that all the branch-points were decomposed by transesterification to form linear molecules. The Mn values of rubber chains assembling the gel was 5.5−8.3×105 by 13C-NMR measurements of the ratio between cis- and trans-isoprene units, which were comparable to the molecular weight between crosslinks, Mc, of 7−11×105 by swelling measurements. These findings suggest that the branching and crosslinks are composed of two types of branch-points, i. e. one by association or aggregation of proteins or oligopeptides at the initiating end and the other by ester linkages including phosphoric ester at the terminal end.

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