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PubMed2003

Influence of lanthanum on the uptake of trace elements in cucumber plant.

The effects of La3+ on the uptake of trace elements (Se, Co, V, and Tc) in cucumber plants were studied by a radioactive multitracer technique. It was observed that the uptake and distribution of these trace elements in roots, stems, and leaves are different under different La3+ treatments. Furthermore, in the control, the plant accumulates 75Se, 56Co, and 48V all in the order roots>leaves>stems, whereas 95mTc was in the order leaves>stems>roots. The accumulations of 75Se and 95mTc in plants treated with different La3+ concentration were in the same order as those in the control, but the uptakes percentages of other kinds of element changed differently. The results indicate that lanthanum treatments to a growing cucumber lead to the change of uptake of trace elements, which suggest that a rare earth element is directly or indirectly involved in the ion transport of the plant and affects plant growth by regulating the uptake and distribution of elements that influence the plant cell physiology and biochemistry.

Biological Transport↗
PubMed1989

Radioactive-electrophoretic assay of adenosine 5'-triphosphate sulfurylase activity in crude extracts with sulfate or selenate as a substrate.

An assay method for ATP sulfurylase is presented which employs Na2(35)SO4 as a substrate and measures the production of labeled adenosine 5'-phosphosulfate and 3'-phosphoadenosine 5'-phosphosulfate by low-voltage, hanging paper strip electrophoresis. The method is applicable to crude bacterial or mammalian extracts and accurately measures picomole amounts of product(s). Na2(75SeO4 can also be employed as a substrate, if the unstable radioactive product, adenosine 5'-phosphoselenate, is converted to elemental 75Se degrees by inclusion of reduced glutathione in the reaction mixture. The same paper strip electrophoretic technique can then be used to separate 75Se degrees from the radiolabeled substrate. The method also has utility for measuring any direct reduction by crude microbial extracts of radioactive selenate to selenite, independent of ATP sulfurylase.

Adenosine Phosphosulfate↗
PubMed1997

The use of a multitracer technique for the studies of the uptake and retention of trace elements in rats.

The uptake by, and distribution and retention of radioactive isotopes in various organs of Wistar rats were examined using the multitracer technique. A hydrocholoric acid solution (pH 3) of a carrier-free radioactive multitracer was prepared from gold foil irradiated with a 14N beam of 135 MeV nucleon. The solution was administered orally to 12 7-week-old male rats. Urine and faeces were collected and each group of three rats was killed at 1, 2, 3 or 6 days after administration. The percentage of administered dose of the 17 elements, Mn, Co, Zn, As, Rb, Sr, Y, Eu, Gd, Er, Tm, Yb, Lu, W, Re, Ir and Pt in the organs blood and excreta were determined using gamma-ray spectrometry. Each element revealed its characteristic distribution among the different organs, including the blood. These results are discussed and compared with those of single-tracer experiments, and the advantages of the multitracer technique are presented.

Administration, Oral↗
PubMed2001

Attomole quantitation of protein separations with accelerator mass spectrometry.

Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as 14C to subattomole sensitivity. We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5%. Micro-proton-induced X-ray emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phopsphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome.

Amino Acids↗
PubMed1981

Mice treated with strontium 90: an animal model deficient in NK cells.

Treatment of BALB/c mice with radioactive isotopes of the bone-seeking element strontium reduces the percentage of specific NK-cell cytotoxicity to only 2.6%, compared with 13.6% for normal BALB/c and 36.3% for athymic (nude) BALB/c. The syngeneic plasmacytoma NS-1 was used as target in a 4th in vitro NK-cell microassay. Marrow cellularity in treated mice is reduced to 12.5% of controls, but haemopoietic and stem-cell functions are taken over by the spleen and the peripheral blood picture remains relatively normal. Allogenic (H-2k) tumour transplants are rejected normally with good anti-H-2k alloantibody response. Haemopoietic and T- and B-cell functions are therefore substantially intact, and the defect seems confined to NK cells. In vivo, after s.c. inoculation of 10(6) NS-1 cells, 8/12 controls grew a solid tumour after a mean delay of 30.5 +/- 1.25 (s.e.) days, whereas 5/6 90Sr-treated mice grew the tumours after a delay of only 10.5 +/- 1.8 days. This markedly reduced delay in the 90Sr-treated mice lends support to suggestions that NK cells play an important role in resisting the establishment of tumour foci (i.e. in antitumour surveillance). Mice treated with 90Sr could be useful in evaluating the in vitro role of NK cells.

Animals↗
PubMed1983

RNA polymerase II ternary transcription complexes generated in vitro.

Ternary transcription complexes have been formed with a HeLa cell extract, a specific DNA template, and nucleoside triphosphates. The assay depends on the formation of sarkosyl-resistant initiation complexes which contain RNA polymerase II, template DNA, and radioactive nucleoside triphosphates. Separation from the other elements in the in vitro reaction is achieved by electrophoresis in agarose - 0.25% sarkosyl gels. The mobility of the ternary complexes in this system cannot be distinguished from naked DNA. Formation of this complex is dependent on all parameters necessary for faithful in vitro transcription. Complexes are formed with both the plasmid vector and the specific adenovirus DNA insert containing a eucaryotic promoter. The formation of the complex on the eucaryotic DNA is sequence-dependent. An undecaribonucleotide predicted from the template DNA sequence remains associated with the DNA in the ternary complex and can be isolated if the chain terminator 3'-0-methyl GTP is used, or after T1 ribonuclease treatment of the RNA, or if exogenous GTP is omitted from the in vitro reaction. This oligonucleotide is not detected in association with the plasmid vector. Phosphocellulose fractionation of the extract indicates that at least one of the column fractions required for faithful runoff transcription is required for complex formation. A large molar excess of abortive initiation events was detected relative to the level of productive transcription events, indicating a 40-fold higher efficiency of transcription initiation vs. elongation.

DNA-Directed RNA Polymerases↗
PubMed1979

Ectopic functioning adrenocortico-myelolipoma in longstanding Nelson's syndrome.

A 26-year-old man with the Nelson's syndrome is described, in whom an abdominal tumour developed, accompanied by recurrent Cushing's syndrome 11 years after total adrenalectomy. Upon removal the tumour was a myelolipoma containing islands of adrenocortical-like elements. On incubation of the tumour with radioactive precursors, its capacity to produce cortisol in vitro was shown. The name adrenocortico-myelolipoma is suggested for this tumour.

Abdominal Neoplasms↗
PubMed2002

[Fast automated finite element mesh generation of residual lower limb for clinical application].

Objective. To develop a model of fast automated mesh generation of residual lower limb for clinical application. Method. Actual geometry of the bone was represented as a standard pretreated model of bone, which was auto-located by employing an affine scaling transformation. Hexahedral or wedge elements were constructed by joining quadrilateral or triangular meshes generated by graph partitioning method and transport-mapping method from successive planar cross sections. Result. A model of fast automated mesh generation of residual lower limb was developed, which can be applied to different amputee and ensure the geometric integrality of bone. Auto-location of the bone was carried out. The mesh refinement can be controlled to adapt to different computational efficiency. The generated elements are hexahedral or wedge elements, both of which are more precise than tetrahedral element. Conclusion. The present method could be applied in finite element analysis method for prosthetic socket designing. Radioactive damage from those techniques such as CT or MRI to the amputee and the difficulty in image processing could be avoided.

Amputation Stumps↗
PubMed1971

Radionuclides and selected trace elements in marine protein concentrates.

The concentrations of various trace elements and radionuclides have been measured in marine protein concentrates prepared from surface feeding fishes. As with concentrates prepared from benthic fishes, the 210Pb-210Po pair are the most significant radionuclides present. Concentrations of stable Pb, Co and Ag in certain concentrates are sufficiently high to contribute substantially to estimated current intakes of these elements.

Animals↗
PubMed1987

[Activation of solid materials in a medical linear electron accelerator].

Using the medical linear electron accelerator SL 75/20 supplied by Philips and employing a radiation time of 15 minutes with the 16 MeV high-energy photon stage, we measured the radioactivities induced by photons and neutrons, at the output elements (target, compensator body, wedge filter, diaphragms), at the positioning table of the patient and at a barium oxide concrete wall, via Ge(Li) spectrometry. The resulting local dose rates were determined. The radioactivity that is mainly caused by the nuclides W 187, Sb 120, Cu 64, Cu 62, Ni 57, Mn 56, Al 28, Mg 27 and Al 26 m results (with the exception of the target) in a local gamma-Dose rate of the order of 10 mu Sv/h, respectively. beta radiation, however, is expected to markedly increase these values. The total dose rate of 15 mSv/h in the target region, which retains this indeed rather high level even 7 minutes after radiation has been discontinued, makes it imperative to control the local dose rate and if necessary--depending on the irradiation conditions--to introduce waiting times of several hours if manipulations in this area have to be performed.

Electrons↗
PubMed1997

Computer-assisted analysis of Mycobacterium avium fingerprints using insertion elements IS1245 and IS1311 in a Caribbean setting.

A total of 33 clinical isolates of the Mycobacterium avium complex from 25 patients, identified by means of biochemical and cultural characteristics, the Accuprobe system and DT1/DT6 PCR, were further analysed using novel insertion elements IS1245 and IS1311 in a French Caribbean setting. PvuII-cleaved DNA and non-radioactive Southern hybridization and detection systems were used for fingerprinting with both IS elements. The data confirmed the specificity of the two probes for M. avium in our setting and highlighted a significant proportion of M. intracellulare-infected patients in this region. Two distinct groups composed of 2-3 bands and 6-27 bands were found among M. avium isolates, and were composed of the same isolates both with IS1245 and IS1311. The computer analysis of polymorphic banding patterns identified two prevalent genotypes: one contained 4 isolates from 3 patients while a second 2-banded cluster was composed of 6 isolates from 4 patients; all the patients were from the same hospital in Guadeloupe. A single isolate from Martinique was falsely included in the 2-banded cluster initially upon IS1245 fingerprinting, but could be discriminated from other isolates on the basis of IS1311 fingerprinting of PvuII-cleaved DNA. These results were also confirmed upon IS1245 fingerprinting of PstI-digested DNA, as well as DT6 fingerprinting. A single case of polyclonal infection was also discovered in a patient at a 75-day interval. This is the first study comparing the two IS elements and constitutes a first description of disseminated M. avium complex disease from the Caribbean. We conclude that both elements possess a similar discriminatory potential for M. avium isolates. Coupled with computer analysis, this methodology would appear to be particularly suitable for larger epidemiological studies.

Acquired Immunodeficiency Syndrome↗
PubMed2005

The emerging Medical and Geological Association.

The impact on human health by natural materials such as water, rocks, and minerals has been known for thousands of years but there have been few systematic, multidisciplinary studies on the relationship between geologic materials and processes and human health (the field of study commonly referred to as medical geology). In the past few years, however, there has been a resurgence of interest in medical geology. Geoscientists working with medical researchers and public health scientists have made important contributions to understanding novel exposure pathways and causes of a wide range of environmental health problems such as: exposure to toxic levels of trace essential and non-essential elements such as arsenic and mercury; trace element deficiencies; exposure to natural dusts and to radioactivity; naturally occurring organic compounds in drinking water; volcanic emissions, etc. By linking with biomedical/public health researchers geoscientists are finally taking advantage of this age-old opportunity to help mitigate environmental health problems. The International Medical Geology Association has recently been formed to support this effort.

Dust↗
PubMed2002

Uptake and distribution of trace metal elements in wheat seedlings.

The uptake and distribution of eight metallic elements were examined in wheat seedlings for a period of 12 d with a radioactive multitracer technique. The radioactive nuclides of the seedlings were simultaneously determined by gamma-ray spectrometry. All of the elements studied were taken up by the wheat seedlings and mainly accumulated in the roots. Only some elements were transported to shoots and leaves of the seedlings or bound to leaf proteins, and two elements were transported into the chloroplast. Uptake of most elements reached a maximum on the fifth or the eighth day and then gradually decreased afterward. In the cases of 95mTc and 72Se, the uptake increased continuously within 12 d without the peak uptake. The change of elemental concentrations was dependent on uptake and excretion rates. The dynamics of metal elements taken up by the wheat seedlings and their distribution in roots, shoots, and leaves were different for each element, suggesting that it may depend on the characteristics of the elements.

Chloroplasts↗
PubMed1999

Relationship between the biodistributions of radioactive metal nuclides in tumor tissue and the physicochemical properties of these metal ions.

This study was undertaken to elucidate the relationship between the biodistribution of radioactive metal nuclides in tumor tissue and its physicochemical properties. Potassium analogs (86Rb, 134Cs, 201Tl) were taken up into viable tumor tissue, although 22Na concentrated in necrotic tumor tissue. 67Ga and 111In were more predominant in inflammatory tissue than in the viable and necrotic tumor tissue. 169Yb and 167Tm accumulated in viable tumor tissue and tissue containing viable and necrotic tumor tissue. 67Ga, 111In, 169Yb and 167Tm were bound to the acid mucopolysaccharide with a mol. wt. of about 10,000 daltons in the tumor tissue. 46Sc, 51Cr, 95Zr, 181Hf, 95Nb, 182Ta, and 103Ru were highly concentrated in inflammatory tissue and were bound to the acid mucopolysaccharides with a mol. wt. exceeding 40,000 daltons. 65Zn and 103Pd concentrated in viable tumor tissue and were bound to the protein in the tissue. The results suggest that the difference in intra-tumor distribution of these elements is caused by a difference in the binding substances (or status) of these elements in the tissues, and the binding substance is determined by physicochemical properties of the elements. We therefore conclude that the biodistribution of radioactive metal ions in tumor tissue is determined by its own physicochemical properties.

Animals↗
PubMed2002

Instrumental neutron activation analysis of minor and trace elements in food in the Russian region that suffered from the Chernobyl disaster.

The control of food quality, using the analysis of essential and toxic element contents, assumes an urgent importance within the regions that suffered from the Chernobyl disaster. Instrumental neutron activation analysis was used to study contents of 17 chemical elements (calcium, chlorine, cobalt, chromium, cesium, iron, mercury, potassium, magnesium, manganese, sodium, rubidium, antimony, scandium, selenium, strontium, and zinc) in foods within the south and southwest territories of the Kaluga Region that was exposed to radionuclide contamination. The radionuclide contamination ranges up to 15 Ci/km2 there. Flesh and meat products, dairy products, bread, vegetables, legumes, roots, fruits, and mushrooms were analyzed. The concentration of essential and toxic elements in the different foods were in the normal ranges.

Diet↗