Serum molybdenum

Yet, apart from raised serum molybdenum levels, these people also had increased XDH activity and uric acid levels in the blood. Symptoms of gout which were associated with higher blood levels of uric acid were identified in the majority of people examined. 

Versieck J, Hoste J, Vanballenberghe L, Barrier F, Cornelis R and Waelput I (1981) Serum molybdenum in diseases of the liver and biliary system. J Lab Clin Med 97 535—544. 

Karring, M., R. Pohjanvirta, T. Rahko, and H. Korpela. 1981. The influence of dietary molybdenum and copper supplementation on the contents of serum uric acid and some trace elements in cocks. Acta Vet. Scand. 22 289-295. 

Molybdenum (0.2 ppm) in serum has been determined by Pierce and Cholak 106) by dry ashing and taking up in water. 

Workers at a molybdenum-roasting plant with time-weighted average (TWA) exposures of approximately 9.5mgMo/m to soluble dusts had increased plasma and urine levels of molybdenum the only adverse biochemical findings were large elevations in serum ceruloplasmin levels and some increase in serum uric acid levels. ... 

Mertz DP, Koschnick R, Wilk G, et al. 1968. [Studies on the metabolism of trace elements in humans. I. Serum values for cobalt, nickel, silver, cadmium, chromium, molybdenum, manganese],... 

The most efficient system of this type is obtained by the reduction of bovine serum albumin in the presence of molybdate. Apparently disulfide links in the peptide are broken and form thiolate groups which then bind molybdenum. In a borate buffer, this system will reduce dinitrogen and acetylene, although not using dithionite as an electron source. The turnover is similar to that of the iron-molybdenum cofactor (see Section XII), and dinitrogen reduction is inhibited by carbon monoxide and stimulated by ATP. The yield of ammonia is linearly dependent upon PN2, and the yield is also depressed in the presence of fumarate and, more surprisingly, succinate. It is calculated that the... 

For suspension cultures, the concentration of calcium and magnesium should be kept low to prevent cell aggregation and adhesion. Other metals, such as iron, manganese, selenium, vanadium, zinc, copper, and molybdenum, are usually added to the culture medium, but at reduced concentrations, and mainly if the medium is not supplemented with animal serum. 

Elevated levels of chromium in blood, serum, urine, and other tissues and organs have been observed in patients with cobalt-chromium knee and hip arthroplasts (Michel et al. 1987 Sunderman et al. 1989). Whether corrosion or wear of the implant can release chromium (or other metal components) into the systemic circulation depends on the nature of the device. In one study, the mean postoperative blood and urine levels of chromium of nine patients with total hip replacements made from a cast cobalt-chromium-molybdenum alloy were 3.9 and 6.2 pg/F, respectively, compared with preoperative blood and urine levels of 1.4 and 0.4 pg/F, respectively. High blood and urinary levels of chromium persisted when measured at intervals over a year or more after surgery. These data suggest significant wear or corrosion... 

Hf, "in, and Mo have been applied to study iron ion and molybdenum ion containing proteins, respectively. Finally, " Cd and " Hg have been used in studies of de novo designed heavy metal ion binding proteins and proteins involved in bacterial heavy metal resistance.Other applications include cadmium and indium binding to bovine serum albumin and DNA, as well as in vivo experiments on bacteria. " ... 

A procedure for the determination of molybdenum in serum, red blood cells, and urine is described. The low concentration of molybdenum in most unexposed individuals requires the sensitivity obtained using atomic absorption spectrophotometry and electrothermal atomization. Spike recovery tests indicate that low temperature ashing is required for accuracy. Severe matrix interferences preclude wet ashing or high-temperature ashing as sample pretreatments. Using the method described, it is possible to distinguish between industrially exposed and unexposed individuals. 

Biological fluids such as serum or plasma, red blood cells, and urine are particularly diflBcult to analyze. The low molybdenum concentrations found in normal human samples are below the detection limit of the thiocyanate colorimetric method (100 ng) and much below conventional flame absorption spectroscopy (1 /xg). Normal blood levels of molybdenum are about 10 /xg/L and sample volume is usually < 1 mL. The low concentration and limited sample size preclude direct analysis or sample preconcentration for analysis by the conventional analytical methods. 

Figure 4, Frequency vs. concentration of molybdenum in serum for 80 individuals. Fifteen individuals above 50 fig/L are not shown.

In summary, a method for the analysis of molybdenum in biological fluids has been presented. The method requires the destruction of the organic materials in the sample by low-temperature ashing. Detection was accomplished by using a graphite furnace—atomic absorption technique and the standard additions method. The method is sufficiently sensitive to distinguish between molybdenum levels in the blood, serum, and urine from exposed and unexposed individuals. 

The liver can be affected to varying degrees by excessive intake of molybdenum. Significantly elevated levels of serum bilirubin were observed in dogs receiving 20 mg kg of ammonium molybdate in... 

There is about 0.5 p,g Mo per L (5nmol/L) in plasma or serum and about l Llg Mo per L (lOnmol/L) in whole blood. Urine molybdenum values determined by ICP-MS vary from 40 to 60 pg/L, the amount determined being influenced by recent dietary intake. ... 

Dimyristoylphosphatidylethanolamine (DMPE), biotinyl-N-hydroxysuccinimide ester (BNHS), triethylamine, myoglobin, bovine serum albumin (BSA), lysozyme, guanidinium chloride, dimethylamino-cinnamaldehyde, acrylamide, ammonium persulfate, sodium dodecyl sulfate (SDS), and molybdenum blue reagent were all obtained from Sigma Chemicals and used without further purification as received. The compounds N, N, N, N -tetramethylethylenediamine (TEMED), N, N -methylene-bis-acrylamide, and Coomassie Brilliant Blue R-250 were from BioRad Laboratories. Avidin was obtained from Vector Laboratories with a quoted activity of 14 units/mg. All solvents were from Fisher Scientific. Water was passed through a Barnstead Nanopure system. 

Copper was determined with cuproine in silicate rocks, biological materials, and sea water [112,113], in environmental samples [113], steel and cast iron [114]. Neocuproine was used for determination of copper in biological materials [12,115], foods [116], sea water [117], beryllium [118], arsenic and gallium [119], tungsten [120], aluminium alloys [117], plutonium [121], tellurium [122], and fertilisers [123]. Bathocuproine was applied in determinations of copper in blood serum [124,125], water [126,127], niobium, tantalum, molybdenum, and tungsten [128], lead and nickel [129], cast iron and steel [66]. 

Although trace element abnormalities occur in chronic renal failure, few symptoms have been attributed to them in nondialyzed patients. In dialysis patients these disturbances appear to be qualitatively similar but more severe (T7). They have been extensively reviewed by Alfrey (A5). Total body zinc (except in erythrocytes), strontium, aluminum, and tin are generally increased, whereas total body rubidium is decreased. Iron stores tend to be increased in the spleen and liver in dialyzed patients, especially after ferrous sulfate therapy. Copper is increased in lung tissue and decreased in heart tissue and erythrocytes. Molybdenum and cadmium are decreased in renal tissue but increased in liver tissue of dialyzed and nondialyzed patients. Total body zinc content is significantly increased (A5), but hypozincemia, frequently observed in dialysis patients, has been blamed for taste impairment and impotence and there is conflicting evidence on whether zinc repletion corrects these abnormalities (K4, Ml2). Nickel is also increased in the serum of uremic patients, but this does not appear to be associated with a corresponding increase in tissues (S5). It cannot be concluded that trace element retention in renal failure is of no clinical importance, as shown by the problem of aluminum intoxication, to be discussed later. In addition, trace elements such as rubidium and bromine, which are rapidly depleted in uremic patients on maintenance dialysis (A5), may prove to be essential in normal metabolism. Thus the clinical importance of these element alterations remains unclear. 

To summarize, molybdenum toxicity in animals includes anemia, anorexia, profound diarrhea, joint abnormalities, osteoporosis, hair discoloration, reduced sexual activity, and death (Table 18.10). Diets which are low in sulfate and copper enhance the toxicity of molybdenum. A high molybdenum intake also decreased feed intake by cattle and pigs, while molybdenum levels in the serum, hair, ribs, kidneys, and cerebrum reflect significant intake of the... 

Versieck J, Hoste J, Barrier F, Vanballen-BERGHE L, De Rudder J and Cornelis R (1978) Determination of molybdenum in human serum by neutron activation analysis. Clin Chim Acta 67 135-140. 

This does not mean that all the analytical problems have been solved. Far from it. Evidence from various sources shows that the results of trace element analyses, as currently reported by typical laboratories around the world, may be subject to very large errors indeed. For example, the ratios of highest to lowest laboratory mean values for human blood plasma or serum reported by Versieck and Cornells (1980, see also Ver-sieck, 1985) are 392 (No. of lab. means = 17) for aluminium, 178 (7) for arsenic, 1321 (30) for chromium, 1352 (14) for cobalt 3.2 (36) for copper, 64 (19) for manganese, 7.6 (6) for mercury, 443 (10) for molybdenum, 138 (21) for nickel, 4.5 (19) for selenium, 3.4 (3) for tin, approx. 12.000 for vanadium, and 5.1 (36) for zinc. The authors conclude that many of the disparities between the values reported by different investigators are due to inadequate sampling and sample handling, or to defective analysis. 

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