Distribution of 201Tl in the blood

Thallium-201 distribution in the blood was investigated both in vivo and in vitro. Thallium-201 was distributed into the erythrocytes and plasma with the ratio of 1.4 +/- 0.3 to 1.0, immediately after its administration. The uptake of 201Tl into the erythrocytes in vitro were affected by the incubation temperature and the presence of ouabain and KCl; indicating that the 201Tl was uptaken into cells partly through their membranes Na, K-ATPase. Erythrocytes could retain 201Tl in it, whereas 201Tl was present as free ion in the plasma. Thallium-201 was flew out of erythrocytes into the plasma, keeping the ratio of 201Tl in erythrocytes/plasma to be 1.9 +/- 0.2/1.0.     

Distribution of lipids in human brain

The enormous abundance of lipid molecules in the central nervous system (CNS) suggests that their role is not limited to be structural and energetic components of cells. Over the last decades, some lipids in the CNS have been identified as intracellular signalers, while others are known to act as neuromodulators of neurotransmission through binding to specific receptors. Neurotransmitters of lipidic nature, currently known as neurolipids, are synthesized during the metabolism of phospholipid precursors present in cell membranes. Therefore, the anatomical identification of each of the different lipid species in human CNS by imaging mass spectrometry (IMS), in association with other biochemical techniques with spatial resolution, can increase our knowledge on the precise metabolic routes that synthesize these neurolipids and their localization. The present study shows the lipid distribution obtained by MALDI-TOF IMS in human frontal cortex, hippocampus, and striatal area, together with functional autoradiography of cannabinoid and LPA receptors. The combined application of these methods to postmortem human brain samples may be envisioned as critical to further understand neurological diseases, in general, and particularly, the neurodegeneration that accompanies Alzheimer’s disease.     

Distribution of uranium in human lungs

Several human lung samples were dissected into lobes and uranium and silicon contents in each lobe were determined by the fission track method and the inductively coupled plasma-atomic emission spectrometry (ICP-AES), respectively. It was found that both uranium and silicon concentrations were high in the upper lobe compared with those in the lower one. Though the tendency may be mainly interpreted by the deposition way of airborne dust in the lung, the higher U/Si concentration ratio in the upper part than that in the lower part of lungs may suggest the partial removal of uranium deposited in the lower part of the tissue.     

Distribution of uranium in human bones

Uranium and calcium contents in human bones (skull, rib and femur) were determined by the fission track method and the inductively coupled plasma-atomic emission spectroscopic method (ICP-AES), respectively. The U/Ca concentration ratio in the bones was found to decrease in the order of rib greater than femur greater than skull, which is in accordance with the decreasing order of the mean annual replacement percentage of bone components. Several femur bones were cut into several longitudinal segments, and uranium and calcium contents in each segment were determined. Among these, the U/Ca ratio in the epiphysis was higher than those in the diaphysis.     

Distribution of thorium in human tissues

Neutron activation followed by simple radiochemical separation was employed to determine the concentration of thorium (²³²Th) in different human tissues. The median²³²Th concentrations (ng/g) in tissues with ranges given in parentheses are lymph nodes: 64.7 (31.4–85.5), lungs: 9.2 (1.5–16.0), hair: 5.2 (2.9–11.0), kidney: 1.7 (0.9–4.0), liver: 0.9 (0.2–4.9) and blood 0.01 (0.006–0.030). The reliability of analysis was tested by analyzing standard reference material Orchard Leaves (US, NBS).     

Detection of arsenobetaine in human blood

Arsenobetaine was detected and quantified unambiguously in human plasma, serum and red blood cells by the combination of HPLC with ICP MS. Three different column conditions, i.e. two ionpair chromatographies for anionic (LC-1) and cationic (LC-2) compounds and gel-permeation chromatography (LC-3), were employed to confirm the assignment. Arsenobetaine was detected in every sample as a major component of the water-soluble arsenic compounds, with an increasing concentration in plasma < serum < blood cell fractions. It was the sole detectable arsenic compound in LC-1 and LC-2, while a broad peak corresponding to high-molecular-weight compounds was identified in addition to arsenobetaine in LC-3.     

Indirect atomic absorption spectrometric determination of sulfate in human blood serum.

An indirect method for the determination of sulfate by atomic absorption spectrometry (AAS) is described. Sulfate forms a stable ion-association complex, [Cu(neocuproine)2]2+(SO4(2-)), in neutral medium, which can be extracted into isobutyl methyl ketone in the presence of a polar medium (methanol) with an efficiency higher than 98.0% and the extract can be analysed directly for copper (and hence indirectly for sulfate) by AAS. Measurement of the copper atomic absorption signal from the organic phase allows the indirect determination of 0.14-1.12 micrograms ml-1 of sulfate, giving a 450-fold increase in sensitivity over the conventional method of precipitation with barium. The limit of detection (3 sigma) is 3.2 ng ml-1 which is better than that of ion chromatography (0.15 micrograms ml-1). Indirect AAS allows the accurate assay of inorganic sulfate anion in biological fluids and tissues. The sulfate concentration determined by the proposed method in human blood serum (n = 6 in each instance) was 35.4-43.3 micrograms ml-1 in normal persons, 50.3-62.5 micrograms ml-1 in jaundice patients and 83.3-155.6 micrograms ml-1 in diabetic patients. A good correlation between measured sulfate and the sulfate added to blood serum was obtained.     

Determination of aromatic hydrocarbons and their metabolites in human blood and urine.

Methods for the biological monitoring of aromatic hydrocarbons and their metabolites in the human blood and urine are reviewed. For the determination of the unchanged aromatic hydrocarbon in blood, gas chromatographic head-space analysis is recommended. The metabolites can be monitored by photometric, thin-layer chromatographic, high-performance liquid chromatographic and gas chromatographic methods. For the assessment of health risks caused by aromatic hydrocarbons, reference values and occupational limit values, expressed as biological tolerance values and biological exposure indices, have to be considered.     

Quantitative analysis of disulfiram and its metabolites in human blood by gas-liquid chromatography.

A simple method is described that permits the direct quantitative determination of carbon disulphide, free diethyldithiocarbamate and disulphides derived from disulfiram in 1 ml of a patient's blood. It is based on a gas chromatographic determination of carbon disulphide produced from diethyldithiocarbamate and disulfiram using the head-space technique and a flame-photometric detector. The method is compared with a recently described spectrophotometric method.     

Evaluation of diabetic ketoacidosis-related ionic metabolites in human blood serum by capillary electrophoresis.

Three methodologies are presented to contemplate the analysis of sodium, potassium, chloride, bicarbonate, lactate, acetoacetate, and beta-hydroxybutyrate in blood serum samples of diabetic patients using free solution capillary electrophoresis with indirect detection (214 nm for cations and 254 nm for anions). The cations were analyzed in less than 6 min in an electrolyte comprised of 15 mmol x L(-1) imidazole, 5 mmol x L(-1) lactate and 1 mmol x L(-1) 18-crown-6-ether, adjusted to pH 4.5. Chloride and bicarbonate were analyzed in 2 min in a 5 mmol x L(-1) chromate, 0.1 mmol.L(-1) cetyltrimethylammonium bromide (CTAB), pH 9.0 electrolyte solution. Ketoacids and lactate were analyzed in less than 11 min in an electrolyte composed of 15 mmol x L(-1) 3,5-dinitrobenzoate, 0.1 mmol x L(-1) CTAB, at pH 3.5. All methodologies were validated with respect to linearity, selectivity, sensitivity, precision and accuracy performing adequately for clinical purposes.     

Isotopic analysis of Fe in human red blood cells by multiple collector-ICP-mass spectrometry.

Precise 56Fe/54Fe and 57Fe/54Fe isotopic ratios on human red blood cell (RBC) samples have been measured using multiple collector-ICP-mass spectrometry (MC-ICPMS). The mass spectrometric interferences on Fe isotopes (e.g., 56ArO+ and 57ArOH+) were successfully minimized by a dry plasma condition achieved by a desolvating nebulizer sample-introduction technique. In order to eliminate possible variations in the measured isotopic ratios due to non-mass spectrometric interferences, Fe was separated from remaining organic compounds and major co-existing elements using an ion chromatographic technique. The resulting precisions of the 56Fe/54Fe and 57Fe/54Fe ratio measurements were 0.12 per thousand and 0.20 per thousand, respectively, which were high enough to detect the isotopic variation of Fe in nature. For an interlaboratory comparison, all of the Fe isotopic ratio data were normalized by the ratios for the IRMM-014 international isotopic standard. A series of 12 RBC samples were collected from one person through monthly-based sampling over a period of one year. These were analyzed to test possible seasonal changes in the 56Fe/54Fe and 57Fe/54Fe ratios. Moreover, in order to test possible variations in the 56Fe/54Fe and 57Fe/54Fe ratios among different people, RBC samples were collected from five volunteers (four males and one female). The 56Fe/54Fe and 57Fe/54Fe ratios for a series of 12 RBC samples collected over a one-year period show 3.06 per thousand and 4.51 per thousand lower than the values of IRMM-014, and no significant seasonal change could be found in the ratios. The lack in seasonal changes in the Fe isotopic ratios could be explained by a small contribution of the daily net-intake of Fe (1 - 2 mg/day) onto the total amount of Fe in the human body (2 - 4 g). The 56Fe/54Fe and 57Fe/54Fe ratios for RBC samples collected from four male samples did not vary measurably, whereas the Fe isotopic ratios for a female RBC were 0.3 per thousand/amu heavier than the mean value of four male samples. This difference in Fe isotopes among the individuals can be the result of a difference in uptake efficiency of the Fe through a dietary process from the digestive tract. The data obtained here demonstrate that the isotopic ratios of trace metals can provide new information about metabolic efficiencies of the metallic elements.     

Estimation of human blood plasma 5-hydroxyindoleacetic acid and homovanillic acid.

A method for simultaneous quantification of plasma homovanillic acid and 5-hydroxyindoleacetic acid has been developed, permitting more efficient neurochemical examinations of these often interrelated biogenic amine systems. Zinc sulphate and sodium hydroxide solutions were used for precipitating the protein in plasma prior to injection on the column. This technique allows for cleaner chromatography, greater sensitivity and high precision. The method uses high performance liquid chromatographic separations of these compounds on C18 reversed phase columns with electrochemical detection. The detailed results from controls and untreated parasuicide patients are given.     

Voltammetric determination of cholesterol in human blood serum

Cholesterol has a number of important functions in a human body. The disorders of cholesterol biosynthesis increase the risk of the development of cardiovascular diseases and worsens the function of the immune system. This study is devoted to the development of a method for determining the concentration of cholesterol in blood serum using voltammetry. We selected the following working conditions for the determination of cholesterol: a phosphate buffer solution with pH 6.86 was a supporting electrolyte; potential sweep rate was W = 30 mV/s; and recording was carried out in the constant-current mode. An organomodified electrode was used as a working electrode. The peak was observed at +0.98 V. The dependence of the electrooxidation current of cholesterol on its concentration was linear in the range of 0.1–50 μM with a limit of detection of 0.01 μM. The results of the determination of cholesterol in blood serum by voltammetry were compared to those obtained by the fluorimetric method.     

DTPA complexation of bismuth in human blood serum

The in vivo(212)Pb/(212)Bi generator is promising for application in targeted alpha therapy (TAT) of cancer. One main limitation of its therapeutic application is due to potential release of (212)Bi from the radioconjugate upon radioactive decay of the mother nuclide (212)Pb, potentially leading to irradiation of healthy tissue. The objective of the present work is to assess whether the chelate CHX-A'-DTPA (N-(2-aminoethyl)-trans-1,2-diaminocyclohexane-N,N',N'-pentaacetic acid) bound to a biological carrier molecule may be able to re-complex released (212)Bi under in vivo conditions to limit its translocation from the target site. CHX-A'-DTPA was bound to bovine gamma globulin (BGG) to mimic a model conjugate and the stability of the Bi-CHX-A'-DTPA-BGG conjugate was studied in blood serum by ultrafiltration. TRLFS experiments using Cm(III) as a fluorescent probe demonstrated that linking CHX-A'-DTPA to BGG does not affect the coordination properties of the ligand. Furthermore, comparable stability constants were observed between Bi(III) and free CHX-A'-DTPA, BGG-bound CHX-A'-DTPA and DTPA. The complexation constants determined between Bi(III) and the chelate molecules are sufficiently high to allow ultra trace amounts of the ligand to efficiently compete with serum transferrin controlling Bi(III) speciation in blood plasma conditions. Nevertheless, CHX-A'-DTPA is not able to complex Bi(III) generated in blood serum because of the strong competition between Bi(III) and Fe(II) for the ligand. In other words, CHX-A'-DTPA is not "selective" enough to limit Bi(iii) release in the body when applying the (212)Pb/(212)Bi in vivo generator.     

Determination of 4-methyl-cis-hexahydrophthalic anhydride in human blood by gas chromatography with electron-capture detection.

A gas-chromatographic technique using 63Ni electron-capture detection was applied to the determination of 4-methyl-cis-hexahydrophthalic anhydride in the blood of workers occupationally exposed to this airborne agent. The detection limit was 0.24 nmol ml-1. For occupational exposure to between 0.14 and 0.31 mg m-3 of the anhydride, the anhydride concentration in the workers' blood samples ranged from 3.4 to 10.7 nmol ml-1. The results are consistent with earlier findings in animal exposure experiments and support the view that the hydrolysis of the anhydride in a biological medium is not spontaneous, but might be an enzyme-catalysed reaction. The resulting dicarboxylic acid is excreted by the kidneys without further conjugation reactions.     

Cytokine production after helium-neon laser irradiation in cultures of human peripheral blood mononuclear cells.

The effects of laser light on the immune system have not been extensively characterized. Low-power laser sources, such as the helium-neon (He-Ne) laser with a wavelength of 632.8 nm, have been found to produce photobiological effects with evidence of interference with immunological functions. We have investigated the effects of He-Ne laser irradiation on Ficoll-Hypaque-isolated human peripheral blood mononuclear cells (PBMC). Cultured cells were irradiated for various times at two selected intensities and then stimulated with different mitogens. The rate of incorporation of 3H-thymidine into the DNA of stimulated cells decreased with increasing energy density. The levels of interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in supernatants of the cultures were determined (irradiated either before or after stimulation). When stimulating cells after irradiation, significantly increased levels of all cytokines were detected after 30 min of irradiation (18.9 J cm-2), whereas after 60 min of irradiation (37.8 J cm-2) cytokine levels were found to be significantly decreased.