Stability of thyroxine and triiodothyronine in biological fluids.

The stability of thyroxine and triiodothyronine in serum has been investigated. Apparent levels of total thryroxine, as determined by two different protein-binding assays employing thyroxine-binding globulin as the binding protein, increased significantly in serum and plasma samples stored at room temperature and were signficantly lower in haemolysed samples. Values did not change significantly in samples stored at 4 degrees C, nor in samples stored at room temperature when determined by radioimmunoassay. Total triiodothyronine levels, as determined by radioimmunoassay, fell slightly on storage. Failure to appreciate the effect of storing samples at room temperature on apparent levels of total thyroxine, as determined by some protein-binding assays, could lead to an incorrect assessment of thyroid status.     

Determination of bisphenol A concentrations in human biological fluids reveals significant early prenatal exposure

BACKGROUND: There is broad human exposure to bisphenol A (BPA), an estrogenic endocrine-disrupting chemical widely used for the production of plastic products. BPA is reported to affect preimplantation embryos or fetuses and alter their postnatal development at doses typically found in the environment. We measured contamination of BPA in various kinds of human biological fluids by a novel enzyme-linked immunosorbent assay. METHODS: Blood samples were obtained from healthy premenopausal women, women with early and full-term pregnancy, and umbilical cord at full-term delivery. Ovarian follicular fluids obtained during IVF procedures and amniotic fluids obtained at mid-term and full-term pregnancy were also subject to BPA measurements. RESULTS: BPA was present in serum and follicular fluid at approximately 1-2 ng/ml, as well as in fetal serum and full-term amniotic fluid, confirming passage through the placenta. Surprisingly, an approximately 5-fold higher concentration, 8.3 +/- 8.7 ng/ml, was revealed in amniotic fluid at 15-18 weeks gestation, compared with other fluids. CONCLUSION: These results suggest accumulation of BPA in early fetuses and significant exposure during the prenatal period, which must be considered in evaluating the potential for human exposure to endocrine-disrupting chemicals.     

The identification of particulate matter in biological tissues and fluids.

Sections, 1-2 micron thick, of Araldite embedded tissue were prepared to provide a link between optical and electron microscopy for the identification of crystals. This technique permits examination of individual particles by means of polarising light microscopy, electron microscopy, X-ray energy spectroscopy and electron diffraction. It provides a reliable method for routine and research studies. It has led to the positive identification of individual crystals of calcium pyrophosphate dihydrate and hydroxyapatite in synovial fluids. The method can be applied to the identification of other particulate matter in a variety of biological specimens.     

Advances in the detection of amino acids in biological fluids.

New methods and modifications of existing methods for the determination of amino acids in biological fluids are reviewed. The application of classical ion exhcange, gas chromatography, and combined gas chromatography/mass spectrometry methodology in the clinical biochemistry laboratory are examined and the advantages and disadvantages are noted for these techniques.     

Sensitive ELISA for interleukin-6. Detection of IL-6 in biological fluids: synovial fluids and sera

A monoclonal antibody and an affinity purified polyclonal antibody, both raised against recombinant human IL-6, have been employed in an ELISA procedure to quantitate human IL-6. Both antibodies were very potent in neutralizing the biological activity of recombinant as well as natural human IL-6. The monoclonal antibody was used as the capture antibody whilst the polyclonal antibody, in biotinylated form, was used as the detecting antibody in combination with a streptavidin horseradish peroxidase conjugate and a signal amplification system. The detection limit for natural as well as recombinant IL-6 was 1 pg/ml. A good correlation was found between the ELISA and the B9 biological assay when IL-6 was measured in crude culture supernatants, in synovial fluids of rheumatoid arthritis patients and in the sera of patients with diverse diseases. Immunoprecipitation of IL-6, produced by different cell types, such as monocytes, endothelial cells and smooth muscle cells or derived from biological fluids, such as the serum of a patient with septic shock or the synovial fluid of a rheumatoid arthritis patient, revealed in every case only molecules in the molecular weight range of 21,000-26,000.     

Electrothermal atomic absorption spectrometry of trace metals in biological fluids.

Electrothermal atomic absorption spectrometry has five major advantages for measurements of trace metals in biological materials, in comparison to measurements by conventional flame atomic absorption analysis: (1) Trace metal contamination is minimized by avoidance of preliminary chemical extractions and additions of reagents; (2) Sample volumes are small (1 to 50 mu1). The entire sample is vaporized in electrothermal atomization, whereas in most flame nebulization systems only a small fraction of the sample enters the flame; (3) Atoms are released in higher concentrations. In electrothermal atomization, the atom cloud is released into a relatively small volume of gas. In contrast, in flame atomization, the atom cloud is diluted by the high flow rate of gases and by expansion of gases during combustion; (4) Molecular recombination of atoms is retarded by the atmosphere of inert gas which restricts chemical reactions (e.g., oxidation). In contrast, in flame atomization, oxidation occurs very rapidly; and (5) By programmed increments in temperature, electrothermal atomization permits organic constituents to be pyrolyzed prior to vaporization and atomization of metals. Despite these advantages, electrothermal atomic absorption is particularly subject to interferences and sources of imprecision which necessitate critical evaluations in the prospective analyst's laboratory before an electrothermal method can be confidently employed for diagnostic measurements of a specific trace metal in body fluids.     

Radioimmunoassay for the synthetic ergoline derivative cabergoline in biological fluids.

An antiserum against cabergoline, a powerful dopamine-agonist under clinical trials for the treatment of Parkinson's disease and hyperprolactinemia, has been raised in rabbits by immunization with an immunogen produced by conjugation of cabergoline to bovine serum albumin. The antiserum was able to bind a derivative of cabergoline labelled with tritium and was able to distinguish the drug molecule from some of its close related compounds and from other agents that could be simultaneously present in plasma from patients undergoing treatment with cabergoline. The antiserum and the tritium labelled hapten were used to develop a radioimmunoassay for cabergoline determination in human plasma and urine. A linear relationship between cabergoline added and % radioactivity bound was found in the range 1.9-500 pg/tube. The addition in the assay of 200 microliters human plasma or 25 microliters urine did not affect the specific and the non-specific binding of the radiolabelled hapten so enabling us to obtain a final sensitivity of about 12 pg/ml plasma and 120 pg/ml urine. The assay was validated in terms of reproducibility, precision and accuracy over the whole range of concentrations tested both in plasma and urine. The plasma concentrations at the steady state in a patient with Parkinson's disease who had received the drug at single oral daily doses of 3, 5 and 7 mg were determined using the assay.     

Characterization of peptides found in human biological fluids in macroglobulinemia IgM.

Excessive production of IgM in macroglobulinemia is accompanied frequently by secretion of proteins and peptides which are normally absent from biological fluids. These proteins and peptides are probably secreted by cells producing IgM. Three types of peptides were isolated and their basic properties are described. One peptide showed calcium-binding properties, and the other two peptides were bound to secreted IgM immunoglobulin.     

Determination of colchicine in biological fluids]

The authors described a fluorimetric method of estimation of colchicine applicable to biological fluids, during treatment and, especially, during acute poisoning. Blood and urinary concentrations confirm the data in the literature.     

Autogenous rhythms and self-organization of biological fluids

The process by which biological fluids are crystallized makes it possible to identify rhythmic undulatory oscillations occurring in the liquid phase of the medium. Pathological changes in the body impair physiological rhythms at different levels, these impairments being reflected in the biocrystalline structure of a biological fluid during its self-organization. Targeted modifications of the rhythm characteristic of a biofluid may help to evaluate the resistance of the organism to environmental factors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 10, pp. 364–371, October, 1996     

Bone histoquantitative findings and histochemical staining reactions for aluminium in chronic renal failure patients treated with haemodialysis fluids containing high and low concentrations of aluminium.

A total of 112 undecalcified bone biopsies from 67 patients under treatment for chronic renal failure by maintenance haemodialysis was available for retrospective study. The patients were divided into three groups. Group I (15 cases) had been dialysed for the majority of the time in their own homes with a fluid containing a low concentration of aluminium. Group II (28 cases) had been dialysed exclusively in hospital (prior to 1978) with a fluid containing a high concentration of aluminium and group III (24 cases) had been treated exclusively in hospital (from 1978 onwards) with a fluid of low aluminium concentration. The tissues from these groups were subjected to histoquantitative assessment and stained by a histochemical technique to demonstrate aluminium salt. In group II, 71.4% of cases showed positive aluminium staining reactions (at the osteoid/mineralised tissue interface) compared to 26.6% in group I and 37.5% in group III. Staining reactions were also more extensive in group II cases. The osteoid volume was significantly increased and the calcification front extents significantly decreased in group II compared to both groups I and III. A comparison of histochemically positive with negative cases in each group showed a significantly increased osteoid volume and significantly decreased calcification fronts in the positive cases. It was, therefore, concluded that haemodialysis against a fluid containing a high concentration of aluminium leads to intraosseous aluminium accumulation of greater degree in a larger number of patients than a fluid with low aluminium content and that there is an accompanying osteomalacia manifest by an increase in osteoid volume together with diminution in the extent of the calcification fronts.     

CT findings of the nose and paranasal sinuses in chromium intoxication

We performed computed tomography (CT) of the nose and paranasal sinuses in 21 patients with chromium induced septal perforation or thinning. Twenty patients showed various magnitudes of septal perforation. Twelve of 20 had perforation at the mid portion of the cartilaginous nasal septum. One patient had a sheet-like thinning of septal cartilage. Sixteen patients had mucosal thinning of the nasal conchas. In most cases, unilateral involvement of the inferior concha was seen. Eleven of 21 cases showed paranasal sinus mucosal thickening and one patient had a cyst or polyp in the sinus cavity. The main finding was nodular thickening of mucosa. Septal perforation by inhalation of chromic acid was located in the cartilaginous septum and there was no destruction of the bony septum and wall of the sinuses.