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PubMedDate not supplied

Minor and trace elemental contents of cancerous breast tissue measured by instrumental and radiochemical neutron activation analysis.

Many minor and trace elements influence the permeability of cell membranes by competing for binding sites, and exert direct or indirect action on the carcinogenic process. Instrumental and radiochemical neutron activation analysis has been employed for the determination of more than 20 elements in normal and cancerous breast tissues of 6 patients. Most trace elements, viz., Zn, Cu, Mn, Co, Se, Br, As, Sb and Cd, are elevated in cancerous tissue, whereas lower levels are observed for Fe, Cs, I, and Sr. Similarly, concentrations of minor constituents, such as Na, K, P, Cl, and Mg, are enhanced compared to normal tissue. Several elements incorporate into the normal cell, change its enzymatic activity, and accelerate the growth of tumor.

Breast↗
PubMedDate not supplied

Vanadium determination at the ultra-trace level in biological reference materials and serum by radiochemical neutron activation analysis.

In order to help resolve present inconsistencies of two orders of magnitude or more in reported levels of vanadium in human serum and blood, a totally postirradiation radiochemical neutron activation analysis (NAA) method was further developed and applied to some pertinent nanogram and subnanogram reference materials. In particular, the second generation human serum reference material of Versieck was found to contain a value of 0.67 +/- 0.05 ng/g dry wt., corresponding to 0.061 +/- 0.005 /4/ ng/mL original fresh serum. Results are also reported for some other appropriate CRMs. Additionally, a small-scale study in 10 normal subjects (5 m, 5 f) revealed levels similar to those in the serum reference material and in agreement with the lowest data reported in the literature. Discussion of pitfalls of vanadium determination and the use of reference materials is included.

Adult↗
PubMed1985

Partition of divalent and total manganese in organs and subcellular organelles of MnCl2-treated rats studied by ESR and neutron activation analysis.

The possibility that Mn2+ is converted to other valency states in vivo was examined by measuring the ratio of Mn2+, determined by ESR, to total manganese, determined by neutron activation analysis combined with chemical separation, in various organs of control rats and rats treated with MnCl2. In control rats, the total manganese content was high in the thyroid, hypophysis, adrenal, pancreas, liver and kidney, but the Mn2+ contents of these organs were low. In rats treated with Mn2+, the total manganese contents of all organs increased, but the Mn2+ contents still remained low. With regard to subcellular distribution, the total manganese content was high in the nuclear and mitochondrial fractions of the liver and kidney, and in the microsomal and supernatant fractions of the pancreas. The ratio of Mn2+ to total manganese was relatively high in the microsomes of the liver and kidney of control rats, and in the nuclear fraction of the pancreas of Mn2+-treated rats. Thus, the distribution and behavior of manganese in the pancreas were different from those in other organs. Purified liver nuclei and mitochondria were demonstrated to contain manganese, indicating that manganese is tightly bound in each cellular compartment.

Animals↗
PubMed1999

Total-body calcium estimated by delayed gamma neutron activation analysis and dual-energy X-ray absorptiometry.

Total body calcium (TBCa) in 270 black and white women age 21-79 years was measured concurrently by delayed gamma neutron activation analysis (DGNA) and dual-energy X-ray absorptiometry (DXA). The mean value for TBCa calculated from DXA was 933 g compared with 730 g for DGNA. By regression, TBCa(DXA(g)) = 1.35 x TBCa(DGNA(g)) -54 (r = 0. 90, r(2) = 81.4%, SEE = 66.9 g). This remarkable difference of 203 g suggests that one or both these methods is not accurate. Adjustment of the regression of DXA versus DGNA for body mass index or trunk thickness explained 8.5-10% of the variability between methods. The unadjusted slope for the DXA values regressed against the DGNA values was 1.35, indicating significant discordance between the methods. There is greater agreement between the two DGNA facilities (Brookhaven National Laboratory and Baylor College of Medicine) and between the various DXA instruments. Either DGNA underestimates TBCa or DXA overestimates total-body bone mineral content. Resolution of these disparate results may possibly be achieved by concurrent measurement of whole human cadavers of different sizes with chemical determination of the calcium content of the ash. In the interim, cross-calibration equations between DGNA and standardized values for DXA for total-body bone mineral content may be used, which will permit reporting of consistent values for TBCa from the two technologies.

Absorptiometry, Photon↗
PubMed1987

Intracellular ion content of skeletal muscle measured by instrumental neutron activation analysis.

The intracellular contents of sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), and chloride (Cl-) in rat hindlimb muscles (soleus, plantaris, white and red gastrocnemii) were measured by instrumental neutron activation analysis (INAA) and atomic absorption spectrophotometry (AAS). Muscle extracellular fluid volume (ECFV) was determined using [3H]mannitol, [14C]mannitol, [3H]polyethylene glycol (PEG, mol wt 900, PEG-900) or the chloride (Cl) method and intracellular fluid volume (ICFV) calculated. Rats were anesthetized with pentobarbital sodium. The muscles were biopsied, frozen in liquid nitrogen, freeze-dried, weighed, and transferred to vials for analysis. For a given muscle, ion contents measured by the two methods showed a consistent small difference which could not be explained. The PEG-900 space and the Cl method yielded a larger ECFV than did mannitol; it is concluded that PEG-900 and Cl overestimate ECFV. There were significant differences in total tissue water (TTW), ECFV, ICFV, and intracellular ion contents between the different muscle types. The fast glycolytic muscles (white gastrocnemius, plantaris) had lower TTW (758 ml/kg wet wt) and ECFV (6.5-8.5% TTW) but the highest ICFV; the soleus (slow oxidative fibers) had the highest TTW (766 ml/kg wet wt) and ECFV (10-15% TTW) but the lowest ICFV. The fast-twitch white gastrocnemius and plantaris muscles have a higher intracellular content of K+ and lower Na+ and Cl- than the slow-twitch soleus muscle. The technique of INAA provides a rapid and accurate means of determining intramuscular ion content in small samples of tissue.

Animals↗
PubMed1999

Accumulated experience with prenatal diagnosis of Menkes disease by neutron activation analysis of chorionic villi specimens.

Since 1983, prenatal diagnosis of Menkes disease has been carried out by determining Cu in samples of chorionic villi from the fetus by means of radiochemical neutron activation analysis. Concentrations of Cu in chorionic villi from male fetuses later confirmed to have Menkes disease were invariably higher than previously reported values for normal controls. Out of 240 samples analyzed in the period 1983-1998, there were 71 from female fetuses that could be carriers of the Menkes genetic defect without suffering from the disease. Increased concentrations of Cu in these samples could not be attributed to the presence of this genetic defect, but might result from sporadic contamination of the samples before analysis. Such contamination also may occur in samples from male fetuses and thus raise the level of Cu in small, but normal specimens into the range characteristic of Menkes disease. In spite of a strict protocol for taking samples without contamination, a total of four false positives were reported during the period of investigation; no false negatives have occurred.

Chorionic Villi Sampling↗
PubMed1996

Total body calcium and bone mineral content: comparison of dual-energy X-ray absorptiometry with neutron activation analysis.

The aim of this study was to compare the dual-energy X-ray absorptiometry (DXA) measurement of bone mass with an independent measure of body calcium obtained by neutron activation analysis (NAA). Total body bone mineral content (BMC) was measured using DXA in 46 subjects in the age range 5-47 years (17 children, 28 young women, and 1 adult male). Total body calcium (TBCa) was measured in the same subjects by in vivo NAA. The correlation between the two measures of bone mass was highly significant (BMC[g] = 3.22 x TBCa[g] - 51.4, r > 0.98, p < 0.0001, SEEBMC = 122.7 g). When BMC was the independent parameter, the SEETBCa was 37.5 g. Bland-Altman analysis indicated a mean difference of 2.8 g with a standard error +/- 4.7 g for TBCaNAA versus TBCaDXA when the BMC values were converted to TBCa. The relative change in bone mass (delta TBCa/delta BMC) for DXA was higher than that reported for dual-photon absorptiometry versus NAA. The findings presented in this study provide translational equations among the DXA and NAA measurements and for the conversion of total body BMC to TBCa in children and young adults.

Absorptiometry, Photon↗
PubMedDate not supplied

Multielement determination in rice, wheat, and barley by instrumental neutron activation analysis.

INAA has been used for the determination of Na, Mg, Al, Cl, K, Sc, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Br, Rb, Sr, Mo, and W in grains of rice, wheat, and barley, which were collected from different plant fields in Iraq. Samples and standards were irradiated in the IRT-5000 reactor, at neutron fluxes of 2 x 10(13) cm-2.s-1 and 3.2 x 10(11) cm-2.s-1. Interferences of photopeaks with each other were considered, and reaction interferences were calculated and determined experimentally. Accuracy of our method was assessed by the analysis of IAEA standards Wheat Flour and Bovine liver. A good agreement has been achieved between the present results and recommended values. The precision and detection limit were determined for all elements in all types of grain.

Edible Grain↗
PubMed1994

Determination of tin in biological materials by atomic absorption spectrophotometry and neutron activation analysis.

Concentrations of Tin (Sn) were determined in botanical, dietary and biological reference materials (RMs), and in human livers from Japanese and American subjects using atomic absorption spectrophotometry (AAS) and neutron activation analysis (NAA), either in the instrumental mode (INAA) or in the radiochemical mode (RNAA). The mean Sn concentrations (+/- 1 S.D.) found in various RMs are: total diet (NIST SRM-1548) 3.57 +/- 0.52 and 3.61 +/- 0.52 microgram/g by AAS and INAA, respectively; non-fat milk powder (NIST SRM-1549) 2.5 +/- 1.4 ng/g and 1.9 +/- 0.3 ng/g; bovine liver (NBS SRM-1577) 18 +/- 2 and 20 +/- 0.3 ng/g; and citrus leaves (NIST SRM-1542) 0.25 +/- 0.02 and 0.243 +/- 0.006 microgram/g by AAS and RNAA, respectively. These comparisons demonstrate good agreement between the two methods. In apple leaves (NIST SRM-1515) and peach leaves (NIST SRM-1547), the measured concentrations by AAS were 77.1 +/- 20 and 85 +/- 15 ng/g; interferences by 160Tb did not permit an accurate assessment by INAA at this concentration. The Sn results obtained for the American human liver specimens by RNAA ranged from 0.135-0.712 microgram/g wet weight, and the Sn concentrations in Japanese human liver specimens determined by AAS ranged from 0.078-1.122 microgram/g wet weight in 23 individuals. The results from this study show that it is feasible to use INAA/RNAA and AAS in combination to establish recommended values in RMs.

Animals↗
PubMed2003

Advantages and limitations of thermal and epithermal neutron activation analysis of bulk samples.

Systematic investigations have been carried out to extend the thermal neutron activation method for elemental analysis of bulk samples. A new method developed for the determination of the flux perturbation factor renders the thermal and epithermal neutron activation analyses of bulky samples of unknown compositions possible both in hydrogenous and in graphite moderators. The flux perturbation, F, depression, H, and self-absorption, G, factors are given for different samples. The limitation of the epithermal neutron activation analysis for hydrogenous bulky samples is also discussed.

Journal Article↗
PubMed2001

Characterization of ophiolites from northern Havana-Matanzas petroleum fields using instrumental neutron activation analysis.

Concentrations of 16 elements from 14 serpentinitic samples from Basilio and Cantel petroleum fields were obtained by instrumental neutron activation analysis (INAA): Cr, Co, Ni, La, Nd, Sm, Eu, Gd, Tb, Ce Yb, Lu, Rb, Cs, Hf and Th. Relative INAA was performed using certified reference materials and laboratory standards. Average elemental concentrations showed that the ophiolites have a basic character, suggesting the use of a well-logging method designed for volcano-sedimentary petroleum fields.

Journal Article↗
PubMed1981

Total body bone mineral and lean body mass by dual-photon absorptiometry. II. Comparison with total body calcium by neutron activation analysis.

Total body bone mineral (TBBM) was measured in vivo using dual-photon absorptiometry (DPA) in 10 subjects. The total body calcium (TBCa) was measured in the same subjects using neutron activation analysis. The correlation between the two methods was very high (r greater than 0.99) and the standard error of estimate was low. The TBCa relative to TBBM was about 39%. The two noninvasive methods provided nearly identical indications of skeletal mass, but the radiation exposure with DPA was 500 to 5000 times smaller (0.6 mrem vs 300 to 3000 mrem). The radius shaft bone mineral content was highly correlated with the TBBM (0.97) and the TBCa (0.98) and could be used to estimate the latter variables with errors (1 SEE) of 9% and 6%, respectively.

Body Composition↗
PubMed1983

Increased manganese level in spinal cords of amyotrophic lateral sclerosis determined by radiochemical neutron activation analysis.

The manganese distribution in the cross-section of the cervical, thoracic and lumbar portion of the spinal cords from 7 autopsied cases with amyotrophic lateral sclerosis (ALS) and 6 control subjects were determined by radiochemical neutron activation analysis. It was possible to determine 1 ng levels of manganese content accurately in the small tissues about 1 mg of dried weight using wet ashing and chemical separation after neutron activation. The dried weight of spinal cord was about 1/3 of the wet weight. Manganese concentration in the wet tissue was calculated from the ratio of dried to wet weight. In the anterior horn of the cervical cords of ALS, manganese concentration was the highest; 1.75 +/- 0.39 ng/mg of dried weight and 0.59 +/- 0.09 ng/mg of wet weight, respectively. These were significantly higher (P less than 0.01) compared to those in controls; 1.02 +/- 0.12 ng/mg of dried weight and 0.35 +/- 0.04 ng/mg of wet weight, respectively. The elevation of manganese level in the spinal cords of ALS was more prominent in the anterior horn and lateral column than in the posterior column both in dried and wet tissues. Since manganese inhibits neuronal transmission, it is likely that neurological degenerative changes occur as a result of local disturbances of manganese metabolism in the spinal cord of ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1975

Measurement of liver-cadmium concentrations in patients and industrial workers by neutron-activation analysis.

A new, rapid, non-invasive technique for measuring tissue-cadmium concentrations in patients and industrial workers has been designed and developed with a view to studying the cadmium content of the liver. The method utilises the principle of neutron-activation analysis whereby the specific changes produced by the inter action of nuclei and neutrons are analysed. Liver-cadmium content has been studied in cadavers and in four men with known of suspected cadmium poisoning. The patients all showed very high liver-cadmium levels of between 35 and 200 p.p.m. compared with under 1.0 p.p.m. in non-exposed subjects. The dose of radiation used in clinical studies was 0.4-1.0 rem and the detection limit of cadmium was 1.0 p.p.m.

Adult↗
PubMed1997

Determination of various nutrients and toxic elements in different Brazilian regional diets by neutron activation analysis.

The concentration of 19 elements (As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Rb, Sb, Sc, Se and Zn) was evaluated in some diets taken from different regions of Brazil by Instrumental and Radiochemical Neutron Activation Analysis. Several populations with different socio-economic living conditions and inhabiting in different regions of Brazil were studied in order to estimate and to detect the variability of the mineral and toxic element content among Brazilian populational groups. The data obtained showed a significant difference between the contents of these elements in the diets from the regions studied. The general conclusions from the data obtained in this study were: 1) regarding the daily amounts of essential elements (Ca, Cl, Co, Fe, Mn, Na, K, Fe, Se and Zn), the Santa Catarina 2 diet showed the closest values when compared to the recommended values of RDA (Recommended Dietary Allowance) and/or WHO (World Health Organization). The Santa Catarina 1(low income groups) showed the lowest when compared to the same values. 2) The intake of toxic elements (As, Br, Cd, Hg, Sb) among the diets does not seem to be a major problem when compared to PTWI (Provisional Tolerable Weekly Intake, WHO), except for Hg intakes in regions near gold mining activities, like Manaus and Mato Grosso, where the values found were near the upper limit set by WHO.

Adolescent↗
PubMed1986

Studies on the interaction between SeO2 and sulfur compounds and distribution of Rb, Zn, Co, Fe and Hg in mice by instrumental neutron activation analysis.

Content of Se, Rb, Zn, Co, Fe and Hg in liver, kidneys, spleen, brain and blood of SAS/4 mice were determined after i.p. injection with SeO2, gluthathione, cysteine, cysteamine or methionine. Instrumental neutron activation analysis (INAA) was applied as the analytical method. Se was incorporated in all the examined organs, the the efficiency of the incorporation depended upon the sulfur compounds injected. Injection with above compounds affects the contents of the other elements in all mice organs.

Animals↗
PubMed1976

The influence of seasonal changes in the determination of selenium in liver of various animals by neutron activation analysis and high-resolution spectrometry.

Selenium levels in the liver of animals living in the Umfolozi Game Reserve in Natal and in the Sabi Sand Nature Reserve in the Eastern Transvaal were studied by instrumental neutron activation analysis. The distribution of the selenium content was followed for about 16 months and attempts have been made to explain seasonal fluctuations of the selenium level.

Animals↗