We determined serum cobalt levels in 55 patients by atomic absorption spectrophotometry before and after implantation of uncemented total hip arthroplasties. In a randomised, prospective trial 27 wrought Co-28Cr-6Mo-0.2C metal-on-metal articulations were compared with 28 ceramic-on-polyethylene hips which did not contain cobalt. Other sources of iatrogenic cobalt loading were excluded. The meta...

The distribution and adverse effects, especially to optic and acoustic nerves, of cobalt released from a hip arthroplasty and its association with albumin were studied. The analysis of cobalt was performed in plasma, whole blood, urine, and cerebrospinal fluid by inductively coupled plasma mass spectrometry (ICP-MS). The fraction of albumin binding the metal was determined by colorimetric assay...

Two separate experiments were conducted with sheep‘ grazing Pangola grass pastures. In the first experiment, eight groups of pregnant ewes (six ewes/group) were used. Each group received one of the following supplements, no supplement (control), phosphorus, sodium, iodine, cobalt, mineral mixture, sorghum grain and sorghum grain plus urea. Ewes supplemented with cobalt lost less weight during l...

Long titanium aneurysm clips have recently been released. In the present study, comparative study of long titanium and cobalt alloy clips was performed. Two kinds of Sugita long clips (straight clips of 25- and 35-mm blade length) made of titanium and cobalt alloys were tested by measuring the closing force, the anti-scissoring torque, and the maximum opening width. There were some differences ...

Reaction of pyridinobromocobalt(llI) aetioporphyrin I with a variety of alkyland aryl-magnesium bromides gives the corresponding alkyland aryl-cobalt(lIl) derivatives. In an alternative synthesis, the cobalt(l) derivative of aetioporphyrin J reacts with alkyl or acyl halides to give the alkylor acyl-cobalt(llI) compounds. The latter approach has also been used for the preparation of hydroxyalky...

A sensitive and selective procedure is presented for the voltammetric determination of cobalt. The procedure involves an adsorptive accumulation of cobalt Pyrogallol Red (PGR) complex on a stationary mercury drop electrode, followed by cathodic stripping voltammetry measurement of the reduction current of the adsorbed complex at –1.17 V (vs. Ag/AgCl). The optimum conditions for the determinatio...

A selective spectrophotometric method has been developed for the determination of cobalt after extraction of its 2-methoxyethyl xanthate complex into molten naphthalene. Cobalt reacts with this xanthate in the ratio of 1 : 2 (metal : ligand ratio) in a pH range of 3.5-9.2 and over an acid range of 2.5-7.0 M. It absorbs strongly at 355 nm. Beer's law is obeyed over the concentration range of 2.5...

This paper focuses on how the surface chemical groups of sheep manure affect the adsorption capacity of cobalt ions. Improvement in cobalt ions uptake onto sheep manure was achieved successfully by introducing more carboxylic functional groups into its surface due to citric acid treatment. According to Langmuir model, cobalt ions uptake was increased from 22.88 mg/g for dried sheep manure (D-SM...

Cobalt chloride administration to rats stimulates erythropoesis but inhibits the synthesis of hepatic microsomal P-450 and ethylmorphine N-dealkylase activity by hepatic microsomes. No effect on NADPHcytochrome c reductase activity was observed. Phenobarbital induction of P-450 and ethylmorphine N-demethylation are prevented by simultaneous administration of cobalt chloride but phenobarbital in...

Assimilation of ionic cobalt by axenic cultures of four species of anaerobic rumen bacteria was measured using 6oCo as cobalt (II) chloride. Uptake could be measured in all four species but may not represent active accumulation in the case of Lactobacillus casei and Propionibacterium acnes. Significant uptake (89.5% of 6oCo present) was demonstrated by Selenomonas ruminantium from media contain...