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Biomedical subjects

M Serio

Publications and source records attributed to M Serio.

At least 181 records · Page 10Linked to original sources
PubMed1985

Spermatic and peripheral venous plasma concentrations of testosterone, 17-hydroxyprogesterone, androstenedione, dehydroepiandrosterone, delta 5-androstene-3 beta,17 beta-diol, dihydrotestosterone, 5 alpha-androstane-3 alpha,17 beta-diol, 5 alpha-androstane-3 beta,17 beta-diol, and estradiol in boys with idiopathic varicocele in different stages of puberty.

Serum testosterone (T), 17-hydroxyprogesterone (17P), androstenedione (delta 4-dione), dehydroepiandrosterone (DHA), delta 5-androstene-3 beta, 17 beta-diol (delta 5-diol), estradiol (E2), dihydrotestosterone (DHT),5 alpha-androstane-3 alpha,17 beta-diol (3 alpha diol), and 5 alpha-androstane-3 beta,17 beta-diol (3 beta diol) were measured in the peripheral and spermatic venous blood of 21 boys undergoing surgery for idiopathic left varicocele. The boys were divided into 3 groups according to their pubertal development: prepubertal (group 1 or P1; n = 8), pubertal stage 2 (group II or P2; n = 6), and pubertal stages 3-4 (group III or P3-4; n = 7). The testes of the prepubertal boys secreted T, 17P, DHA, delta 5-diol, DHT, and 3 alpha diol, but not delta 4-dione, E2, and 3 beta diol. In pubertal stage P2, the mean spermatic-peripheral secretory gradients of T, 17P, DHA, delta 5-diol, DHT, and 3 alpha diol were significantly higher than those in the prepubertal stage, and there was testicular secretion of delta 4-dione, E2, and 3 beta diol. In pubertal stage P3-4, the mean spermatic-peripheral secretory gradients of most of these steroids, even if increased, were not significantly different from those in stage P2 (with the exception of 17P, delta 5-diol, and DHA). We suggest that after the important modifications of testicular secretion occurring in pubertal stage P2, the testicular secretory pattern of the pubertal testis is similar to the pattern of the adult testis. We suggest also that these results, obtained in boys with idiopathic varicocele, can probably be extended to the secretory activity of the testes of normal pubertal boys.

17-alpha-Hydroxyprogesterone↗
PubMed1985

Pregnanediol-3 alpha-glucuronide measured in diluted urine by mass spectrometry with fast atom bombardment/negative-ion ionization.

We describe a mass-spectrometric method based on the fast atom bombardment ionization technique in the negative-ion mode for measuring pregnanediol-3 alpha-glucuronide in diluted urine from women. The procedure requires addition of testosterone-17 beta-D-glucuronide (2.5 micrograms/25 microL) to the urine sample as internal standard, and the sample is added directly to the fast atom bombardment target with no further manipulation. We have assessed and evaluated the method by the traditional criteria of reliability.

Adult↗
PubMed1984

Helix pomatia induced conversion of some 3 beta-hydroxysteroids.

After incubating a dehydroepiandrosterone solution with an enzymatic preparation from Helix pomatia, the steroid recovery was markedly decreased. The transforming activity resulted specific for some 3 beta-hydroxysteroids and it appeared to lower after storing the preparation at 4 degrees C for some days. The presence of 4-androsten-3,17-dione within the incubation products suggests that the enzymatic preparation contains at least 3 beta-hydroxysteroid: NAD oxydoreductase and 3-oxosteroid-5-4-ene isomerase. The use of large amounts of freshly dissolved Helix pomatia juice solution may lead to unreliable results in steroid analyses.

Animals↗
PubMed1984

Effects of different dopaminergic antagonists on bromocriptine-induced inhibition of norepinephrine release.

In this study we evaluated the effects of placebo or acute bromocriptine (BC) administration (2.5 mg orally) on plasma catecholamines, systolic and diastolic blood pressure (BP), heart rate, and plasma PRL in six normal subjects [group I, mean age 33.2 +/- 5.4 (SD) yr] in the supine as well as upright position. BC induced a significant decrease in plasma norepinephrine in the supine [167.7 +/- 16.8 (SEM) vs. 101.9 +/- 33.7 pg/ml, P less than 0.005] and upright positions [397.3 +/- 27.7 vs. 211.3 +/- 26.7 pg/ml, P less than 0.005], a decrease in systolic and diastolic BP and a decrease in plasma PRL (P less than 0.01). After standing, epinephrine levels increased significantly (53.6 +/- 11.8 vs. 226.4 +/- 71.0 pg/ml, P less than 0.05). The study was repeated in a second group of seven normal subjects (mean age, 32.3 +/- 12.9 yr) after placebo or metoclopramide (20 mg orally) plus BC. In this group metoclopramide, a central and peripheral antidopaminergic agent, counteracted the BC-induced effects found in group I, both in the basal and stimulated conditions. Plasma PRL increased significantly (P less than 0.025). Finally, to assess the effect of peripheral dopaminergic blockade on BC-induced changes in sympathetic outflow, we repeated the study in seven normal subjects (group III, mean age, 30.1 +/- 5.0 yr) after placebo or domperidone (20 mg orally) plus BC. Domperidone blocked the effects of BC on norepinephrine and BP in the supine position. On standing there was a significant decrease in systolic (P less than 0.05) and diastolic (P less than 0.05) BP and an increase in epinephrine levels (58.9 +/- 12.2 vs. 109.8 +/- 24.6 pg/ml, P less than 0.05) was still observed. Plasma PRL increased significantly (P less than 0.025). The results of this study suggest that the inhibition of sympathetic outflow induced by BC is peripherally mediated. As peripheral dopamine receptor blockade did not counteract all the effects after BC during standing, dopaminergic modulation of central reflex sympathetic activation is suggested.

Adult↗
PubMed1984

Effects of naloxone on catecholamine plasma levels in adult men. A dose-response study.

To evaluate a possible role for endogenous opiates in modulating sympathetic-adrenal function in humans, we measured plasma epinephrine and norepinephrine (radioenzymatic method), blood pressure and heart rate in 8 normal men (aged 24-33 years) before and after placebo or different doses (0.4, 4.8, 10 mg) of naloxone. In 6 subjects plasma insulin and glucagon levels were also measured by radioimmunoassay after placebo and 10 mg naloxone. Naloxone had no significant effect upon blood pressure, heart rate, plasma insulin, glucagon or norepinephrine. Placebo, 0.4 and 4.8 mg naloxone caused no significant change in peripheral levels of epinephrine while 10 mg produced an increase in epinephrine concentrations 15 min after iv injection (186 +/- 23 vs 99 +/- 9 pmol/l, P less than 0.01). Since naloxone did not modify plasma levels of insulin and glucagon, an indirect effect of naloxone on adrenal medullary secretion seems to be excluded. These results are in agreement with in vitro experimental data obtained in animals and suggest that endogenous opiates also have a role in modulating adrenal medullary secretion in man.

Adrenal Medulla↗
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

Effects of pharmacological doses of testosterone and dihydrotestosterone on the hypothalamic-pituitary axis function of Klinefelter patients.

Six patients affected by Klinefelter's syndrome (KS) were treated with testosterone propionate (TP) 100 mg im daily for 4 days and one month later the same patients received dihydrotestosterone propionate (DHTP) 100 mg im daily for 4 days. Plasma levels of LH, FSH, PRL, testosterone (T) and dihydrotestosterone (DHT) have been measured in these patients for 8 days during and after TP and DHTP treatment. TP administration reduced LH levels only transiently, while a more prolonged reduction was observed for FSH. DHTP administration produced a late and transient reduction of LH and a very late reduction of FSH. PRL levels increased significantly during and after TP administration. Our data suggest that in Klinefelter patients: i) DHT is less effective than T in suppressing gonadotropin concentrations, ii) the increased PRL levels observed during and after TP administration are not due to a pure androgenic effect, but are probably related to an increased conversion rate of T to estradiol.

Adolescent↗
PubMed1983

Effects of thyroid replacement therapy on catecholamine plasma levels.

Plasma catecholamines (CA), total and free thyroid hormones (T4, FT4, T3, FT3) and thyrotropin (TSH) were measured before and during therapy in seven normotensive women with primary hypothyroidism lasting for more than 6 months. Twelve normal women matched for age were used as controls. In hypothyroid patients plasma norepinephrine (NE) was found increased in supine and upright position and plasma epinephrine (E) unchanged. After 30-60 days of therapy with dry thyroid extract, NE, T3, and FT3 levels were found in the normal range while T4 and FT4 levels, although raised, were still significantly lower than those of controls. These results seem to demonstrate that low doses of replacement therapy can restore NE levels to normal and therefore suggest that severe hypothyroidism alone is able to affect the sympathetic function.

Adult↗
PubMed1983

Steroid secretion by the prepubertal human testis.

It has been demonstrated that the human testis secretes testosterone and, to a smaller extent and less constantly, also androstenedione. Testosterone, progesterone, 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone have been measured in the spermatic and peripheral venous blood of prepubertal boys undergoing surgery for undescended testis or inguinal hernia repair. The spermatic plasma levels of testosterone and progesterone were significantly higher than peripheral levels. A significant spermatic-peripheral gradient was not found for 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone. These studies demonstrate that the secretory pattern of the human prepubertal testis is different from that of the adults.

Androgens↗
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↗
PubMed1983

Spermatic and peripheral venous plasma concentrations of dehydroepiandrosterone sulfate in prepubertal and pubertal boys.

Dehydroepiandrosterone sulfate (DEAS), a major adrenal product, is quantitatively one of the most important steroids found in human testicular tissue. However, conflicting data have been reported about the testicular production of DEAS 'in vivo'. We have measured the spermatic and peripheral concentrations of testosterone (T) and DEAS in two groups of prepubertal (Group I, N = 18) and pubertal (Group II; N = 11) boys undergoing surgery for undescended testis, inguinal hernia or varicocele. Mean (+/- SE) spermatic concentrations of DEAS (77 +/- 16 and 113 +/- 19 micrograms/dl in Group I and II respectively) were not significantly different from peripheral concentrations (70 +/- 13 and 130 +/- 16 micrograms/dl in Group I and II respectively). Mean spermatic concentrations of T (153 +/- 101 and 7515 +/- 4314 ng/dl in Group I and II respectively) were significantly different from peripheral concentrations (9 +/- 1 and 149 +/- 53 ng/dl; P less than 0.001 in both groups). Spermatic and peripheral levels of T and DEAS found in prepubertal boys were significantly lower than those found in pubertal boys. Spermatic levels of DEAS were not significantly related with spermatic levels of T in both groups. Our data show that, as in adult subjects, no significant spermatic-peripheral DEAS gradient is present in prepubertal and pubertal boys.

Adolescent↗
PubMed1983

Spermatic and peripheral venous plasma concentrations of progesterone, 17 alpha-hydroxyprogesterone, and 20 alpha-dihydroprogesterone in prepubertal boys.

Testosterone, progesterone, 17 alpha-hydroxyprogesterone, and 20 alpha-dihydroprogesterone have been measured in the spermatic and peripheral venous blood of 17 prepubertal boys undergoing surgery for undescended testis or inguinal hernia repair. Mean (+/-SE) spermatic testosterone and progesterone (538 +/- 212 and 704 +/- 110 pg/ml, respectively) were significantly higher (P less than 0.005) than peripheral levels (91 +/- 11 and 419 +/- 71 pg/ml, respectively). No significant spermatic-peripheral gradient was found for 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone. These in vivo studies demonstrate that the secretory pattern of the prepubertal testis is different from the adult testis.

20-alpha-Dihydroprogesterone↗
PubMed1982

ATP and ADP content of human ejaculated spermatozoa. I. Relationship with semen physical parameters in normal donors and oligozoospermic patients.

ATP and ADP were measured by a bioluminescent method in human ejaculated spermatozoa from 31 normal donors and oligozoospermic patients. ATP and ADP expressed for the sperm total number were significantly correlated (P less than 0.001). ATP snd ADP levels were found significantly correlated with the total motile spermatozoa and with the total viable cells (respectively P less than 0.001 and P less than 0.001 for ATP and P less than 0.001 and P less than 0.001 for ADP). ATP/ADP ratio was found significantly lower in subjects with sperm motility less than 50% (P = 0.024) and total viable cells less than 80% (P = 0.026).

Adenosine Diphosphate↗
PubMed1982

ATP and ADP content of human ejaculated spermatozoa. II. Time-dependent changes after ejaculation.

ATP and ADP content of ejaculated spermatozoa of 7 donors were measured by a bioluminescent method within 24 h. The semen samples were kept at room temperature and at prefixed time were tested for motility and viability and extracted for ATP and ADP measurement. ATP pattern in relation to the time was studied with a mathematical model and the resulting curve showed a very high significance (P less than 0.001). ADP decrease with time was not significant and was variable among our subjects. The relationship between ATP decrease (%) and the decrease (%) of viability and motility was not linear, and till now no mathematical model has been found to express this phenomenon.

Adenosine Diphosphate↗
PubMed1981

Evaluation of different progesterone-isoluminol conjugates for chemiluminescence immunoassay.

The effect of varying the length of the alkyl bridge linking the chemiluminescent label isoluminol to progesterone on the light yield and binding affinity of progesterone chemiluminescent-marker conjugates was investigated. For this purpose five different derivatives of isoluminol, aminoethyl isoluminol (AEI), aminoethylethyl isoluminol (AEEI), aminobutyl isoluminol (ABI), aminobutyl-ethyl isoluminol (ABEI) and aminoethyl-ethyl isoluminol (AHEI) were covalently linked through a peptide bond to progesterone-11 alpha -hemisuccinate (P-11-HS). The resulting progesterone chemiluminescent-marker conjugates were then evaluated as potential labels for the development of an immunoassay based on monitoring chemiluminescence. These conjugates were able to compete with tritiated progesterone for the binding sites of an antibody raised against progesterone-11 alpha-HS bovine serum albumin, and they showed higher affinity than unaltered progesterone. These conjugates produced light upon oxidation by a hydrogen peroxide-microperoxidase system. The chemiluminescent reaction was optimized in terms of pH, concentration of oxidant, catalyst and conjugate design. Under optimal conditions, all the conjugates were detectable at femtomolar levels. The lowest detection limit was obtained using P-11-HS-ABEI (0.1 fmol). These results indicated that immunoassay techniques based on chemiluminescence can be developed with these labels.

Animals↗