Cobalt accumulation in horses following repeated administration of cobalt chloride.

OBJECTIVE: To monitor cobalt concentrations in urine, red blood cells and plasma after chronic parenteral administration of cobalt chloride evaluate these results against the current International Federation of Horseracing Authorities thresholds for detecting cobalt misuse. DESIGN: Eight mares were randomly assigned to four treatment groups, with two mares in each group: Group 1 - control group, Group 2 - 25 milligrams cobalt intravenously as CoCl2 weekly, Group 3 - 50 milligrams cobalt intravenously as CoCl2 weekly, and Group 4 - 25 milligrams cobalt intravenously mid-week and at the end of the week. Urine and blood samples were collected before each weekly administration so that trough levels were assessed. In the group receiving two doses per week, urine and blood were collected prior to the dose given at the end of each week. Samples were initially collected at time zero then weekly for 10 weeks. Three further collections of urine and blood were made at days 81, 106 and 127. METHODS: Urine creatinine measurements to assess horse hydration status were performed by the Jaffe reaction method. Cobalt determinations in plasma, blood and urine were by inductively coupled plasma-mass spectrometry. Haematocrit concentrations, used to calculate red cell cobalt levels, were performed using a microhematocrit centrifuge. Statistical analyses were conducted in Genstat (v17, VSNi). RESULTS: Marked cobalt accumulation was evident with increasing cobalt concentrations for all sample matrices in specimens collected immediately prior to cobalt administration. Correlation between the sample matrices improved when urine cobalt concentration was adjusted for creatinine level. Red cell cobalt levels remained elevated for at least 12 weeks after cessation of administration, consistent with the lifespan of the red cell. There was no significant change in haematocrit concentrations for the duration of the study. CONCLUSION: The current urine cobalt threshold was only effective at detecting acute cobalt exposure while the plasma cobalt threshold was able to consistently identify chronic high-level cobalt exposure and potential cobalt misuse. The threshold values legislated for urine cobalt do not correlate with those set for plasma. The acute nature of urinary cobalt excretion provides a relatively small window through which cobalt administration is detected. Plasma and red cell cobalt concentrations can provide a clearer picture of potential cobalt misuse.

Cobalt complexes as internal standards for capillary zone electrophoresis-mass spectrometry studies in biological inorganic chemistry.

Run-by-run variations are very common in capillary electrophoretic (CE) separations and cause imprecision in both the migration times and the peak areas. This makes peak and kinetic trend identification difficult and error prone. With the aim to identify suitable standards for CE separations which are compatible with the common detectors UV, ESI-MS, and ICP-MS, the CoIII complexes [Co(en)3]Cl3, [Co(acac)3] and K[Co(EDTA)] were evaluated as internal standards in the reaction of the anticancer drug cisplatin and guanosine 5'-monophosphate as an example of a classical biological inorganic chemistry experiment. These CoIII chelate complexes were considered for their stability, accessibility, and the low detection limit for Co in ICP-MS. Furthermore, the CoIII complexes are positively and negatively charged as well as neutral, allowing the detection in different areas of the electropherograms. The background electrolytes were chosen to cover a wide pH range. The compatibility to the separation conditions was dependent on the ligands attached to the CoIII centers, with only the acetylacetonato (acac) complex being applicable in the pH range 2.8-9.0. Furthermore, because of being charge neutral, this compound could be used as an electroosmotic flow (EOF) marker. In general, employing Co complexes resulted in improved data sets, particularly with regard to the migration times and peak areas, which resulted, for example, in higher linear ranges for the quantification of cisplatin.

Comparison of platinum chromium everolimus-eluting stent with cobalt chromium everolimus-eluting stent in unselected patients undergoing percutaneous coronary intervention.

OBJECTIVE: The recent PLATINUM trial has demonstrated that the use of the new generation platinum chromium everolimus-eluting stents (PtCr-EES) yield clinical outcomes similar to those obtained by the use of cobalt chromium everolimus-eluting stents (CoCr-EES) in selected patients with 1 or 2 de novo coronary artery lesions. This study aimed to compare the safety and efficacy of the PtCr-EES and CoCr-EES in unselected patients from a real-life single-center registry. PATIENTS AND METHODS:   From July 2009 through November 2010, 788 consecutive patients in our institution with symptomatic coronary artery disease who were treated with the CoCr-EES (n = 410) or PtCr-EES (n = 378) were enrolled into this study. The primary endpoint of the study was target-lesion failure (TLF) at 12-month follow-up and the secondary endpoints were major adverse cardiovascular events and stent thrombosis. RESULTS: The prevalence of TLF in the PtCr-EES group (4.5%) was similar to that in the CoCr-EES group (3.9%). In addition, there were no significant differences in the 12-month rates of cardiac death (2.1% vs. 1.5%), myocardial infarction (2.4% vs. 3.9%), ischemia-driven target lesion revascularization (2.4% vs. 2.2%), and definite or probable stent thrombosis (0.5% vs. 1.5%, all p > 0.05). CONCLUSIONS: At 12-month follow-up, the PtCr-EES is comparable in safety and efficacy to the CoCr-EES in unselected patients with coronary artery diseases.

Postoperative magnetic resonance imaging artifact with cobalt-chromium versus titanium spinal instrumentation: presented at the 2013 Joint Spine Section Meeting. Clinical article.

OBJECT: Cobalt-chromium alloy (CoCr) rods haves some preferred biomechanical properties over titanium rods for spinal fixation. The use of CoCr rods in spinal fusion is relatively new, and there is no study in the existing world literature assessing the artifact caused by these rods in patients undergoing postoperative MRI. The purpose of this study is to compare the amount of imaging artifact caused by these implants and to assess its impact on the visualization of neighboring neural structures. METHODS: This study investigated MR images in patients who underwent implantation of thoracolumbar instrumentation using 5.5-mm-diameter CoCr rods between November 2009 and March 2011 and images obtained in a comparison group of patients who had 5.5-mm titanium rods implanted during the same time period. Axial measurements of the artifact created by the rods between the screw heads were compared between the groups. Two blinded board-certified radiologists performed the measurements independently. They scored the visualization of the spinal canal using a subjective scoring system of 1-3, with 1 representing very good visualization and 2 and 3 representing reduced (good or suboptimal, respectively) visualization as a result of rod-related artifact. All measurements and scores were independently provided for T1-weighted and T2-weighted fast spin echo sequences (1.5-T magnet, 5-mm slice thickness). RESULTS: A total of 40 levels from the CoCr group (6 patients) and 30 levels from the titanium group (9 patients) were included in the analysis. Visualization of the canal at all levels was rated a score of 1 (very good) by both evaluators for both the CoCr and titanium groups. The average artifact on T1-weighted images measured 11.8 ± 1.8 mm for the CoCr group and 8.5 ± 1.2 mm for the titanium group (p < 0.01). The corresponding measurements on T2-weighted images were 11.0 ± 2.3 mm and 8.3 ± 1.7 mm (p < 0.01), respectively. In a mixed regression model, the mean artifact measurement for the CoCr group was, on average, 3.5 mm larger than for the control group. There was no significant difference between the measurements of the 2 evaluators (p = 0.99). CONCLUSIONS: The artifact caused by CoCr rods is approximately 3.5 mm larger than that caused by titanium rods on axial T1- and T2-weighted MRI. However, artifact from either CoCr or titanium was not found to interfere with the evaluation of the spinal canal and surrounding neural elements.

Defining reference values of trace elements in the tear film: diagnostic methods and possible applications.

The study has been performed on tears of apparently healthy subjects who live and work in urban and rural areas, respectively. After the collection the following elements were investigated: chromium (Cr); arsenic (As); copper (Cu); zinc (Zn); selenium (Se); rubidium (Rb); barium (Ba); lead (Pb) and cobalt (Co). Significantly higher values of As were found in subjects living and working in rural areas as compared to those found in urban area residents (0.290 vs. 0.025; p<0.001). Conversely, Ba and Pb were significantly lower in rural area residents (1.10 vs. 2.50, p=0.027 and 1.70 vs. 1.10, p=0.057, respectively). Our data show that trace elements analysis in tears is possible; further studies could define if it could be a reliable biomarker in persons exposed to high concentration of trace elements due to working or environmental reasons.

Patch test reactivity to metal allergens following regulatory interventions: a 33-year retrospective study.

BACKGROUND: Contact allergy epidemics to chromate and nickel were addressed in Denmark in 1983 and 1990 by regulatory interventions. OBJECTIVES: To evaluate whether regulatory interventions on nickel and chromate exposure have reduced the proportion of strong patch test reactions. METHODS: 22 506 patients with dermatitis aged 4-99 years were patch tested with nickel sulfate, potassium dichromate, or cobalt chloride between 1977 and 2009. RESULTS: The proportion of 3+ reactions to nickel sulfate was reduced and almost disappeared after the mid- and late 1980s (P-trend = 0.001). Today, 1+ and 2+ nickel reactions occur equally frequent. Cobalt chloride patch test reactivity reflected the nickel development to some degree. The proportion of 3+ reactions to potassium dichromate was reduced during the 1980s (P-trend = 0.13), whereas the proportion of 2+ reactions to potassium dichromate have increased in recent years. CONCLUSIONS: The decrease in nickel sulfate and cobalt chloride 3+ patch test reactivity began long before the Danish nickel regulation came into effect. This could be because of research activity at the time as well as political attention in Northern Europe. The chromate content in cement regulation may have changed the epidemiology of patch test reactivity; however, in recent years, 2+ reactions to chromate have increased markedly, a development that should be carefully followed.

Tissue reaction to implants of different metals: a study using guide wires in cannulated screws.

Cannulated screws, along with guide wires, are typically used for surgical fracture treatment in cancellous bone. Breakage or bending deformation of the guide wire is a clinical concern. Mechanically superior guide wires made of Co-Cr alloys such as MP35N and L605 may reduce the occurrence of mechanical failures when used in combination with conventional (316L stainless steel) cannulated screws. However the possibility of galvanic or crevice corrosion and adverse tissue reaction, exists when using dissimilar materials, particularly in the event that a guide wire breaks, and remains in situ. Therefore, we designed an experiment to determine the tissue reaction to such an in vivo environment. Implant devices were designed to replicate a clinical situation where dissimilar metals can form a galvanic couple. Histological and SEM analyses were used to evaluate tissue response and corrosion of the implants. In this experiment, no adverse in vivo effects were detected from the use of dissimilar materials in a model of a broken guide wire in a cannulated screw.

[Toxicological characteristics and standardization of various poly-metallic oxides]. / Toksikologicheskaia kharakteristika i reglamentatsiia riada polimetallicheskikh oksidov.

Acute toxicity, functional cumulative and local effects of the four ++poly-metallic oxides YBa2Cu3O7, Bi4Sr3O16, Tl2Ca2Cu3O10, Lao,7Sro,3CoO3, were studied in laboratory animals. Parallel experiments on assessment toxicity of the regular oxides of the studied metals in mice were carried out. The major dissolution of metals was shown to occur in acid medium. Thallium-barium-calcium cuprite turned out to be the most toxic and cumulative; it induced the most severe morphologic changes in the liver and kidneys. The least severe disorders caused by this substance were in the rat gastric mucosa and in rabbit eye after a conjunctival injection. Yttrium-barium cuprite induced the most severe changes at the site of injection, lanthanum-strontium cobaltite ranks second here. All copper-containing polymetallic oxides show resorptive toxicity when applied to the skin. Different types of combined toxicity are possible, that is why MACs for the regular oxides can not be used for setting the normal concentrations of ++poly-metallic oxides in air. Estimated toxicometric parameters helped to score the concentrations, which may serve as tentative safe levels of the studies substances.

Energy-dispersive X-ray microanalysis of air-dried microdroplets containing a macromolecular solute.

In the preparation of microdroplets of biological fluids for X-ray microanalysis, we have found that incorporation of a macromolecular solute, dextran, to a final concentration of 1.5-2.5% retards crystal formation and produces sufficiently uniform deposits on thin films to allow droplets to be analysed without prior freeze-drying. Analyses have been carried out at 20 kV in a scanning electron microscope, using energy-dispersive spectrometry. Absorption of Na X-rays by the added solute can be significant but its effect is minimized by preparing droplets as thin as possible, and by using standards of similar composition. The minimum detectable concentrations are increased because of the extra background contribution, and for a single determination are about 6 mM for Na and 2 mM for Cl and K. These concentrations can be further reduced by measuring replicates. The reproducibility of analysis is significantly improved (to less than 5% for Na and K) over the use of calibration curves by calculating the element concentrations from a known element in the sample, chlorine. Under our analytical conditions loss of Cl did not occur. This method requires that the Cl is measured separately by microcoulometry, but eliminates the need for a range of standard droplets on the grid, and determination of the unknowns is then independent of droplet volume, beam current, counting time and magnification. We have compared, with biological samples, the results from using Cl as an internal standard with those obtained using an added standard element, cobalt. The reproducibility using Cl was approximately two-times better than that obtained with Co, probably because of unavoidable volumetric errors when the Co is pipetted separately.

Cobaltoterapia en Sucre evaluación del primer año de trabajo

1.La Cobaltoterapia en Cáncer de cuello uterino es más beneficiosa cuando la dosis tumor oscila entre 3.500 y 4.500 rads cuando el grado histologico del tumor muestra nenor diferenciación y cuanto más temprano se la utiliza, Concluimos que es ideal para el tratamiento de ésta localización del cáncer, 2.-La Cobaltoterapia en el Cáncer de Mama es excelente en los grados iniciales y con dosis tumor fluctuantes entre 5.000 y 8.000 rds. 3.-La Cobaltoterapia siempre tiene efecto en todos los tipos de cáncer cuando la dosis tumor es suficiente y el tumor no este en estado muy avanzado, 4.-La Cobaltoterapia tiene muy poco efecto en los sarcomas, 5.-La cobaltoterapia tiene excelentes resultados en los Linfomas malignos, 6.-El porcentaje de 54,73 por ciento de resultados buenos es mayor debido a que el 66,98 por ciento de los pacientes vienen en estados avanzados, 7.-Los resultados mediatos buenos de la Cobaltoterapia son mayores que los buenos inmediatos