PubMed Health⌕ Search

Biomedical subjects

M Pazzagli

Publications and source records attributed to M Pazzagli.

At least 37 records · Page 2Linked to original sources
PubMed1984

Homogeneous luminescence immunoassay for total estrogens in urine.

We describe an homogeneous luminescence immunoassay for "total" estrogens in enzymically hydrolyzed urine from nonpregnant women. The antiserum, raised against estriol-16,17- dihemisuccinate conjugated to bovine serum albumin, specifically bound the C-19 steroids carrying the estrogen-characteristic phenolic group. 17 beta-Estradiol conjugated with aminobutylethyl isoluminol was used to monitor the immunological reaction; this conjugate was stable for at least two years. Because binding to the antiserum markedly enhances the light-producing efficiency of the tracer, no separation of bound and free antigen is necessary. Results (microgram/24 h) by this method (y) correlated well (r = 0.958) with those by a conventional fluorometric (x) method (y = 2. 51x - 2.83). The sensitivity (detection limit) is 4 micrograms/L and the precision compares well with that of commonly used RIA methods. The method appears suited to large numbers of samples, as in menstrual cycle monitoring.

Cross Reactions↗
PubMed1984

On-line computer analysis of chemiluminescent reactions, with application to a luminescent immunoassay for free cortisol in urine.

We interfaced a microcomputer on-line with a luminometer to acquire the light signal of chemiluminescent reactions from a photomultiplier and then compute significant parameters of light emission and kinetic "shape" indices. Using this system to study interferences from biological samples on the measurement of chemiluminescent reactions, we observed that such effects are usually associated with modifications of the shape of the light-emission kinetics. These results suggest that a simultaneous evaluation of the shape of a chemiluminescent reaction and the measurement of light emission can be combined to assess luminescent immunoassays as an internal control of the interferences in measurements of the chemiluminescent tracer. As an example of this approach, we developed and validated a luminescent immunoassay for free cortisol in diluted urine. Dextran-coated charcoal is used for bound-free separation.

Chemical Phenomena↗
PubMed1983

A solid phase chemiluminescent immunoassay (LIA) for testosterone glicuronide in diluted urines.

A chemiluminescent immunoassay (LIA) method in solid phase for the measurement of testosterone 17 beta-D-glicuronide (TG) in diluted urine is described, which utilizes as tracer a TG-isoluminol conjugate (TG-ABEI). An IgG fraction of antiserum of TG-BSA, has been passively adsorbed to the walls of polystyrene tubes. After the binding reaction the coated tubes were washed with buffer and the measure of chemiluminescence reaction was performed at high pH. The assay was validated in terms of specificity, accuracy, sensitivity and precision. The values obtained by chemiluminescence immunoassay were compared with that obtained by the RIA method, and the two methods agreed well (r = 0.95, n = 28). The assay method offers the advantage of speed and does not involve the use of radioisotopes or of a centrifugation step. Preliminary results show that the mean 24 h urinary TG excretion in a group of hirsute women is higher than in the control group, and decreases after suppression with dexamethasone for 1 month of therapy.

Cushing Syndrome↗
PubMed1983

Preparation and evaluation of steroid chemiluminescent tracers.

Six different isoluminol derivatives have been synthesized and evaluated as potential labels for conjugation to steroid molecules. The resulting steroid-chemiluminescent tracers have been investigated in terms of detection limit and affinity for the homologous antibody. The conjugation to the steroid molecule did not significantly affect the quantum yield of the chemiluminescent label. Consequently the detection limit was very similar using tracers with the same chemiluminescent label and different steroids and it was always at picomolar levels. The affinity of the chemiluminescent tracer versus the homologous antibody was evaluated using tritiated steroids as reference. The bridge and the chemiluminescent molecule could influence the affinity of the chemiluminescent tracer which could be higher, similar or lower than that of the tritiated steroid. In conclusion some isoluminol derivatives (i.e. ABEI or AEEI) can be considered as universal labelling compounds for steroids and their metabolites, because they possess a high light efficiency (similar to luminal itself) and favourable reaction conditions. Moreover the conjugation to the steroid molecule does not modify their chemiluminescent properties.

Animals↗
PubMed1981

Spermatic and peripheral oestradiol levels in patients affected by azoospermia due to seminiferous tubular damage.

Plasma levels of testosterone, androstenedione and oestradiol were determined in the spermatic venous blood of both testes of 17 patient affected by azoospermia due to tubular damage (Group I). The results were compared with those found in 5 patients affected by azoospermia of obstructive origin and 5 patients with an inguinal hernia (Group II). Mean spermatic levels of testosterone and androstenedione were not significantly different in the two groups, while the mean (+/- SE) oestradiol spermatic level was significantly higher in patients of Group I (5.02 +/- 0.75 nM/l vs. 2.20 +/- 0.365 nM/l; P less than 0.05). Moreover, while the testosterone/androstenedione and the androstenedione/oestradiol ratios were not significantly different in the two groups, the mean (+/- SE) testosterone/oestradiol ratio was significantly lower in patients of Group I (552.71 +/- 80.94 vs. 939.86 +/- 129.45; P less than 0.025). Peripheral testosterone and androstenedione mean levels were not significantly different between the two groups while the mean peripheral oestradiol level (+/- SE) was significantly higher in Group I (0.107 +/- 0.021 nM/l vs. 0.038 +/- 0.05 nM/l; P less than 0.025). Peripheral oestradiol was not significantly related to peripheral FSH, nor to spermatic oestradiol in both groups. These results suggest the possibility that oestradiol may be involved in the pathogenesis of some cases of male infertility.

Adult↗
PubMed1979

Seminal plasma levels of testosterone and 5 alpha-dihydrotestosterone in azoospermic patients.

Testosterone (T) and 5 alpha-dihydrotestosterone (DHT) have been measured in seminal plasma of sixteen azoospermic patients with tubular damage (germinal cell arrest or Sertoli cell only syndrome) and five patients affected by azoospermia of obstructive origin. In both groups T values were not significantly different from controls, while DHT was significantly lower in patients affected by azoospermia of obstructive origin.

Dihydrotestosterone↗
PubMed1978

Klinefelter's syndrome: a study of its hormonal plasma pattern.

Plasma testosterone (T), dihydrotestosterone (DHT), 17 beta-estradiol (E2), 17-hydroxyprogesterone (17-OHP), androstenedione (delta), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), 5-androstene-3 beta-17 beta-diol (A-diol) and cortisol (F) have been measured in a group of normal males and in a group of patients with Klinefelter's syndrome (KS) before and after hCG stimulation. Significantly lower baseline levels of T and DHT and significantly higher baseline levels of E2 were found in patients with KS. No significant differences were found between baseline levels of 17-OHP, delta, DHEA, DHEAS, A-diol, and F. After hCG stimulation between T, DHT, E2 and 17-OHP levels showed a significant increase in the two groups of subjects. The percentage variation of T and DHT, however, was much less important in Klinefeiter patients, while E2 and 17-OHP did not show a significantly different pattern from that of normal controls, hCG administration did not produce any significant variation of delta, DHEA, DHEAS, and F in the two groups of subjects, while A-diol levels increased significantly in normal subjects, but not in Klinefelter patients. Our data may be consistent with the hypothesis that testicular steroidogenesis in Klinefelter patients is impaired below the 21-C-steriod level not only at delta 4 but also at the delta 5 pathway.

Adolescent↗
PubMed1977

Plasma androgens in women with hyperprolactinaemic amenorrhoea.

Cortisol, androstenedione, testosterone, dehydroepiandrosterone sulphate (DHAS) and free dehydroepiandrosterone (DHA) were measured in plasma of ten women affected by amenorrhoea with hyperprolactinaemia and eleven women affected by secondary hypothalamic amenorrhoea; twelve normal women at the second day of the menstrual cycle were used as controls. All subjects were hospitalized and 17-ketosteroids, 17OH-corticosteroids and total dehydroepiandrosterone were also measured in urine. Plasma DHAS was increased in all subjects affected by amenorrhoea with hyperprolactinaemia, while plasma DHA and urinary DHA were significantly increased in this group in comparison to other groups. Plasma cortisol, androstenedione and testosterone and urinary 17-oxosteroids and 17OH-corticosteroids were not significantly differnt in the three groups. In subjects affected by amenorrhoea with hyperprolactinaemia treated with bromocriptine a clear decrease of DHAS correlating with a decrease of plasma prolactin was observed. Since in wome DHAS sems to be almost exclusively secreted by the adrenal gland and most of the circulating DHA is dervied from adrenal secretion, these data suggest that human prolactin can stimulate DHAS production by the adrenal cortex.

Adrenal Cortex↗
PubMed1976

Dihydrotestosterone in human ovarian venous plasma.

Androstenedione (delta), oestradiol-17beta (Oe2), 5alpha-dihydrotestosterone (DHT), progesterone (P) and testosterone (T) concentrations have been measured by radioimmunoassay in ovarian and peripheral venous blood from 15 women in the luteal phase of the cycle. The ovarian blood samples were obtained during surgical intervention from 15 ovaries containing the corpus luteum and from 5 contralateral ovaries. The mean concentration of DHT in ovarian venous blood was not higher than that found in the cubital vein. However in some cases with high concentrations of testosterone in ovarian venous blood, a small but significant DHT gradient was found.

Adult↗
PubMed1975

Radioimmunoassay of plasma dihydrotestosterone in normal and hypogonodal men.

A radioimmunoassay for determination of dihydrotestosterone (DHT) in man is described. After extraction from plasma, DHT is separated by paper chromatography. The radioimmunoassay is performed using an antiserum to dihydrotestosterone-3-oxime-BSA and a charcoal-dextran mixture is used to separate the free from the bound fraction. The reliability criteria of the method in terms of precision, accuracy, sensitivity and specificity have been evaluated. The mean level of DHT in plasma samples from young (age 21-37) and old (age 65-90) normal men is respectively (mean+/-SD) 54-7+/-19 ng/dl (n = 17) and 39-1+/-19 ng/dl (n = 14). The difference is statistically significant (P less than 0-01). The values found in seven patients with Klinefelter's syndrome (21-0+/-6 ng/dl) are significantly lower than normal young subjects (P less than 0-01). Lastly, the DHT levels found in a mixed group of male hypogonadism (azoospermia, due to tubular failure, germinal cell aplasia and anorchia) are reported.

Adult↗