Highly sensitive quantitation of methamphetamine by time-resolved fluoroimmunoassay using a new europium chelate as a label.
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A simple and highly sensitive time-resolved fluoroimmunoassay of methamphetamine (MA) using a new fluorescent europium chelate (BHHCT-Eu3+) as a label is described. Two variations of competitive immunoassay were attempted. In the first (one-step) assay, microtiter plates coated with anti-MA were used, and the new label was bound to a conjugate of bovine serum albumin and N-(4-aminobutyl)-MA (MA-BSA). In the second (two-step) assay, instead of the labeled MA-BSA, biotinylated MA-BSA and BHHCT-Eu3+-labeled streptavidin-BSA were used. The lowest measurable concentrations of MA for the one-step and the two-step methods were 1 ng/mL (25 pg/assay) and 1 pg/mL (25 fg/assay), respectively. These were 10 to 1000 times superior to the detection limits of MA in any other immunoassay. Intra-assay coefficient of variation was approximately 2-8% at eight different concentrations (n = 4). Analysis of 34 urine samples with the new method and conventional gas chromatography showed a good correlation (r = 0.954). The high detectability of the present assay also enabled segmental hair analysis with a few centimeters of a hair. (+info)
Characterization of monoclonal antibodies for prostate-specific antigen and development of highly sensitive free prostate-specific antigen assays.
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BACKGROUND: The recent elucidation of the importance of serological free prostate-specific antigen (PSA) in the diagnosis of prostate cancer has created a demand for immunoassays specific for free PSA. METHODS: We developed and characterized 11 monoclonal antibodies with high affinities for PSA (Ka values from 1.1 x 10(8) to 1.8 x 10(10)L/mol), only 3 of which cross-react with human glandular kallikrein (hK2). Using these antibodies and PSA antibodies developed by others, in conjunction with time-resolved fluorometry, we developed ultrasensitive sandwich immunoassays specific for the free form of PSA. RESULTS: The analytical detection limit of these immunoassays is 0.001 microg/L. To our knowledge, this is the most sensitive free PSA assay reported to date. The free PSA immunoassays exhibit <1% cross-reactivity with PSA-alpha1-antichymotrypsin, show no cross-reactivity with hK2, and correlate well with established free PSA kits. The 11 antibodies developed by our group, in conjunction with 4 commercially available antibodies, were used to generate a putative epitope map of the PSA molecule. CONCLUSION: The highly sensitive free PSA immunoassays may be used for measuring PSA subfractions in female serum, an application currently impossible with other reported free PSA immunoassays. (+info)
Increased episodic release and disorderliness of prolactin secretion in both micro- and macroprolactinomas.
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To quantify prolactin (PRL) secretion patterns, ten untreated (female) microprolactinoma patients and six (male) macroprolactinoma patients underwent repetitive blood sampling every 10 min over 24 h. PRL release activity was analyzed from plasma PRL concentration (immunofluorimetric assay) profiles via a model-independent discrete peak detection program (Cluster) and a waveform-independent deconvolution technique (Pulse). Diurnal variations were analyzed by cosinor analysis. The number of distinct PRL pulses (mean +/- S.E.M.) was increased in patients: microprolactinoma 18.6 +/- 0.6/24 h versus female controls 12.4 +/- 0.6 (P = 6.7 x 10-s), and macroprolactinoma 18.0 +/- 0.9 versus male controls 13.5 +/- 0.8/24 h (P = 0.003). In patients, PRL pulse height, amplitude, pulse area and interpeak nadir concentrations were each greatly elevated compared with gender-matched controls. By 2-component deconvolution analysis, the mean nadir PRL secretion rate in microprolactinoma patients was augmented 20-fold at 0.408 +/- 0.089 microgram/l per min versus in female controls 0.019 +/- 0.009 microgram/l per min (P < 0.001); and in macroprolactinoma by 130-fold at 2.067 +/- 0.693 micrograms/l per min versus male controls 0.016 +/- 0.001 microgram/l per min (P = 0.001). Corresponding 24 h mean PRL secretion rates were in women, 0.658 +/- 0.147 and 0.044 +/- 0.018 (P < 0.001), and in men, 3.309 +/- 1.156 and 0.035 +/- 0.010 micrograms/l per min (P = 0.001), being respectively 15- and 94-fold increased in tumors. The estimated PRL production per day was 160 +/- 15 and 187 +/- 20 micrograms in male and female controls respectively. PRL production was 2860 +/- 640 micrograms in female patients with microadenomas (P < 0.001), and 37,800 +/- 5900 micrograms in male macroadenoma patients (P = 0.001). Cosinor analysis of the plasma concentrations revealed a significant rhythm in nine of ten, patients with a microadenoma, and in five of six with a macroadenoma. The same method applied to pulse height and amplitude disclosed a significant rhythm for PRL pulse height, but not for pulse amplitude, suggesting preserved rhythmicity of baseline interpulse nadir PRL concentrations. Approximate entropy (ApEn), a scale- and model-independent regularity statistic, averaged 1.6559 +/- 0.028 in microprolactinoma patients versus 0.8128 +/- 0.079 in female controls (P = 1.7 x 10(-8)); ApEn in macroadenomas was 1.5674 +/- 0.054 versus male controls 0.8773 +/- 0.076 (P = 1.7 x 10(-5), signifying greater secretory irregularity in the patients. Compared with microadenomas, macroadenomas exhibited a higher mean plasma concentration, overall mean PRL secretion rate, nadir secretion rate and pulse area, but similar peak frequency. We conclude that PRL secretion by prolactinomas is characterized by increased plasma PRL episodicity of release, increased total (15- to 100-fold) and basal (20- to 130-fold) secretion rates, and increased disorderlines of minute-to-minute secretion. These abnormalities of secretory control are very similar to those for GH and ACTH identified earlier in acromegaly and Cushing's disease respectively, thus suggesting mechanistic generality of pituitary tumor secretory derangements, independent of the particular hormone. (+info)
The effect of chronic treatment with GH on gonadal function in men with isolated GH deficiency.
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Eleven adult males, previously submitted to neurosurgery because of a pituitary lesion (three with craniopharyngioma, three with clinically non-functioning adenoma and five with macroprolactinoma) were treated with recombinant GH for 12 months after the diagnosis of GH deficiency was made. Circulating FSH, LH, prolactin, testosterone, 17 beta-estradiol (E2), dehyroepiandrosterone (DHEA-S), androstenedione. 17-OH-progesterone (17OHP), IFG-I, and steroid hormone-binding protein (SHBG) levels were assayed before and after CG test at study entry and 6 and 12 months after GH treatment. A significant increase in plasma IGF-I levels was obtained after 6 and 12 months of GH treatment. In addition, CG-stimulated, but not baseline, testosterone levels showed a significant increase after 6 and 12 months of GH treatment when compared with study entry (9.6 +/- 0.5 and 9.9 +/- 0.5 vs 7.9 +/- 0.5 ng/ml; P < 0.05). Baseline, but not CG-stimulated, serum 17OHP levels were significantly increased only after 12 months of GH treatment (1.7 +/- 0.1 vs 1.4 +/- 0.1 ng/ml; P < 0.05). No significant difference was found as far as both basal and CG-stimulated E2, androstenedione, DHEA-S and SHBG were concerned. With regards to the semen analysis, only seminal plasma volume was significantly increased after 12 months of GH treatment (2.9 +/- 0.3 vs 1.7 +/- 0.3 ml; P < 0.05). No significant change in sperm count, motility and abnormal forms was observed. These data show that GH treatment displays a clear-cut effect upon Leydig cell function and increases the production of seminal plasma volume in fertile adult males with isolated GH deficiency. (+info)
Combined inhibin and CA125 assays in the detection of ovarian cancer.
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BACKGROUND: The reproductive hormone inhibin has been used as a diagnostic marker of ovarian mucinous and granulosa cell cancers. The aims of this study were to develop a new inhibin immunofluorometric assay (alphaC IFMA) to replace an inhibin RIA as a diagnostic marker of these ovarian cancers and to assess whether the alphaC IFMA in combination with CA125, which detects serous cancers, leads to an improved biochemical diagnosis of all ovarian cancers. METHODS: Serum inhibin concentrations were determined in healthy postmenopausal women (n = 165) and women with ovarian cancers (n = 154), using an inhibin RIA and an alphaC IFMA, which detects inhibin forms containing the alphaC subunit as well as the free alphaC subunit. RESULTS: The alphaC IFMA gave a similar or better discrimination of mucinous (90% vs 71%) and granulosa cell (100% vs 100%) cancers compared with the inhibin RIA. Combination of CA125 and alphaC IFMA values by canonical variate analysis or by multiROC analysis showed that the percentage of all ovarian cancers detected was significantly increased compared with either CA125 or alphaC IFMA alone. CONCLUSIONS: The alphaC IFMA shows a similar or better specificity compared with the RIA, but with increased sensitivity. In combination with CA125, the alphaC IFMA provides an effective dual test for the detection of the majority (90%) of ovarian cancers. (+info)
Effects of repeated jugular puncture on plasma cortisol concentrations in loose-housed dairy cows.
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In three experiments, the effects of venipuncture on plasma cortisol concentrations were studied in loose-housed dairy cows. In Exp. 1, two blood samples were collected 18 min apart on three alternate days from 20 dairy cows for studying their adrenocortical response to a single venipuncture. To further evaluate the effect of cows anticipating venipuncture, in Exp. 2, 15 dairy cows were sequentially venipunctured once daily on 12 successive days in a randomized order in groups of five, starting 15 min apart. In Exp. 3, 10 primiparous cows were used on three alternate days to study habituation to serial sampling (i.e., collection of five blood samples by venipuncture, 15 min apart). In cows accustomed to handling, jugular puncture did not affect cortisol concentrations in plasma collected 18 min later. Average daily cortisol concentrations varied between 2.07 +/- .38 and 3.81 +/- .56 ng/mL in the first (t = 0) and between 1.43 +/- .15 and 2.61 +/- .72 ng/mL in the second (t = 18) blood samples. Likewise, when cows were sampled sequentially once a day, the order of sampling between and within groups did not influence (P > .05) plasma cortisol concentrations. In contrast, primiparous dairy cows that were less used to being handled showed an average increase in cortisol concentrations when five samples were collected by venipuncture 15 min apart. During successive sampling sessions, however, the cows did not decrease or increase plasma cortisol concentrations in response to repeated serial sampling at the group level (P > .05). Between individuals, the maximum effect of repeated venipuncture on cortisol concentrations (4.5 to 22.6 ng/mL), the time at which the effect reached its maximum (30 to 60 min), and the consistency of the response pattern over successive series varied largely. The results of this study show that in cows that were accustomed to handling and to being restrained, baseline cortisol concentrations can be measured in single blood samples that are collected by jugular puncture within 1 min after first approaching the cow. When successive blood samples need to be collected within 15 to 20 min, jugular puncture may induce an increase in cortisol concentration, which seems to depend on the handling experience of the animals and on individual differences. (+info)
Alpha2-macroglobulin and eosinophil cationic protein in the allergic airway mucosa in seasonal allergic rhinitis.
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As previously demonstrated in seasonal allergic rhinitis, increased microvascular permeability and eosinophil activation are key features of allergic airway inflammation. In the present study, the hypothesis that exudation of alpha2-macroglobulin may cause the appearance of eosinophil cationic protein (ECP) in the airway lumen was explored. Nasal lavages were carried out using the nasal pool device before and during the pollen season both at baseline and after histamine challenge in 10 children with allergic rhinitis. Nasal lavage fluid levels of alpha2-macroglobulin and ECP were determined. All patients experienced nasal symptoms of allergic rhinitis during the pollen season (p<0.01-0.05). Baseline nasal lavage fluid levels of alpha2-macroglobulin and ECP were increased during the season (p<0.01-0.05) and were found to be well correlated (p<0.0001). Histamine produced concentration-dependent plasma exudation before and during the pollen season, but it was only during the pollen season that this caused an increase in the lavage fluid levels of ECP (p<0.05). These data suggest that exudation of plasma and increased tissue levels and output of eosinophil cationic protein characterize nasal mucosal inflammation in children with seasonal allergic rhinitis. The plasma exudation process in part may account for lumenal entry of eosinophil cationic protein molecules that have been released in mucosal tissue compartments. A combination of induced exudation and nasal lavage may improve the yield of important markers of inflammation in studies of nasal diseases. (+info)
Measuring endocrine profiles of women in field studies.
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Improved methods are needed to evaluate the effects of occupational and environmental hazards on the reproductive health of human female populations. This communication describes highly specific, sensitive, and reliable time-resolved fluorescence immunoassays for measuring luteinizing hormone (LH) and follicle-stimulating hormone (FSH), estrone 3-glucuronide (E13G), and pregnanediol 3-glucuronide (Pd3G) in urine, a fluid that is convenient and painless to collect serially from large populations. Furthermore, some of the technical issues relevant to the successful application of these measurements to field studies are discussed. (+info)