Francesco Romanelli

Arachidonic acid and its metabolites effects on testosterone production by rat Leydig cells

Arachidonic acid (AA) seems to play an important role in testicular steroidogenesis, although controversial data exist in the literature. In the present study AA induced a dose related increase of testosterone (T) formation and, at the highest dose, stimulated the production of prostaglandin E2 (PGE2), leukotrienes B4 (LTB4) and C4 (LTC4) by purified rat Leydig cells. The contemporary addition of the prostaglandin synthesis blocker, indomethacin (IND), and AA further increased T formation, decreased PGE2 levels and did not modify LTB4 and LTC4 concentrations. The addition of a lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA, 5 μM), did not influence the stimulatory effect of AA on T and PGE2 formation while it decreasedthe output of LTB4 and LTC4. When 20 μM NDGA was used in addition to AA the expected reduction of leukotrienes release was observed together with a surprising impairment of T and PGE2 secretion. PGE2 and PGF2alpha did not modify basal T production but reduced HCG-stimulated T secretion at the 10nM dose. When 5–12-and 15-HETE were tested an enhancement of basal T formation was observed at the 10nM dose. 5-HETE (10nM) stimulated HCG-induced T production. LTA4, LTB4 and LTE4 did not influence basal T output while LTC4 and LTD4 inhibited it. LTC4 (10nM) induced a decrease of HCG-stimulated T production. These findings suggest that: 1) exogenous AA stimulates T secretion; 2) conversion of AA to cycloxygenated and lipoxygenated metabolites is not required for its steroidogenic effect; 3) cycloxygenated and lipoxygenatedcompounds play a diverse modulatory role on testicular steroidogenesis.

The role of antioxidant therapy in the treatment of male infertility: An overview

In recent years, many studies have focused on the effect of oxidative stress, reactive oxygen species (ROS) and antioxidants on the male eproductive system. Under physiological conditions, sperm produces small amounts of ROS, which are needed for fertilisation, acrosome reaction and capacitation. However, if an increased production of ROS is not associated with a similar increase in scavenging systems, peroxidative damage of the sperm plasma membrane and loss of DNA integrity typically occur, which leads to cell death and reduced fertility. Furthermore, since there is no linear correlation between sperm quality and pregnancy rates, an improvement in semen parameters should not be the sole outcome considered in studies of antioxidant therapies. A definitive conclusion regarding the benefit of these therapies is difficult to obtain, as most of the previous studies lacked control groups, considered different antioxidants in different combinations and doses, or did not evaluate pregnancy rates in previously infertile couples. Even if beneficial effects were reported in a few cases of male infertility, more multicentre, double-blind studies performed with the same criteria are necessary for an increased understanding of the effects of various antioxidants on fertility.

Pituitary adenylate cyclase-activating polypeptide regulates rat Leydig cell function in vitro

The present study was designed to evaluate the effects of both pituitary adenylate cyclase-activating polypeptide (PACAP)-27 and PACAP-38 on testosterone, cAMP and prostaglandin E2 (PGE2) production by purified rat Leyding cells. Because PACAP-38 shares homology with vasoactive intestinal peptide (VIP), the effects of VIP and both PACAP and VIP receptor antagonists on testicular steroidogenesis were also examined. PACAP-38 potentiated testosterone response to a low effective dose of human chorionic gonadotropin (hCG), while PACAP-27 was without effect. Furthermore, PACAP-38 amplified testosterone response to a wide concentration range of hCG until the submaximal dose. VIP evoked a dose-dependent increase of both basal and hCG-induced testosterone production. PACAP potentiation of steroidogenesis was nullified in the presence of a PACAP antagonist, but was not modified by a VIP antagonist. Moreover, while VIP antagonist blunted testosterone response to VIP, PACAP antagonist was without effect. Increasing concentrations of PACAP-38 evoked a dose-response enhancement of both cAMP and PGE2 production. However, this fatty acid is not involved in PACAP activity, as a prostaglandin blocker indomethacin did not modify the effect of PACAP on steroidogenesis. Taken together these findings: (i) demonstrate that PACAP-38 is able to activate both cAMP- and phosphatidylinositol-dependent mechanisms in Leydig cells; (ii) indicate that the peptide exerts an amplificatory action on testicular steroidogenesis stimulated by hCG and that this activity is receptor-mediated, as it is prevented by a PACAP receptor antagonist; (iii) predict the existence of specific PACAP receptors (type 1 binding sites) on Leydig cells.

Detection rate of FNA cytology in medullary thyroid carcinoma: a meta‐analysis

The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine‐needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta‐analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates.

The use of core needle biopsy as first-line in diagnosis of thyroid nodules reduces false negative and inconclusive data reported by fine-needle aspiration

BackgroundThe reported reliability of core needle biopsy (CNB) is high in assessing thyroid nodules after inconclusive fine-needle aspiration (FNA) attempts. However, first-line use of CNB for nodules considered at risk by ultrasonography (US) has yet to be studied. The aim of this study were: 1) to evaluate the potential merit of using CNB first-line instead of conventional FNA in thyroid nodules with suspicious ultrasonographic features; 2) to compare CNB and FNA as a first-line diagnostic procedure in thyroid lesions at higher risk of cancer.MethodsSeventy-seven patients with a suspicious-appearing, recently discovered solid thyroid nodule were initially enrolled as study participants. No patients had undergone prior thyroid fine-needle aspiration/biopsy. Based on study design, all patients were proposed to undergo CNB as first-line diagnostic aspiration, while those patients refusing to do so underwent conventional FNA.ResultsFive patients refused the study, and a total of 31 and 41 thyroid nodules were subjected to CNB and FNA, respectively. At follow-up, the overall rate of malignancy was of 80% (CNB, 77%; FNA, 83%). However, the diagnostic accuracy of CNB (97%) was significantly (P < 0.05) higher than that of FNA (78%). In one benign lesion, CNB was inconclusive. Four (12%) of the 34 cancers of the FNA group were not initially diagnosed because of false negative (N = 1), indeterminate (N = 2) or not adequate (N = 1) samples.ConclusionsCNB can reduce the false negative and inconclusive results of conventional FNA and should be considered a first-line method in assessing solid thyroid nodules at high risk of malignancy.

Medullary thyroid cancer diagnosis: An appraisal

Since its first description in 1951, a timely diagnosis of medullary thyroid carcinoma (MTC) may represent a diagnostic challenge in clinical practice. Several contributions have been addressed to the treatment and follow‐up of MTC, but review articles focused on the diagnostic problems of this cancer in clinical practice are sparse. As a delayed diagnosis and an inadequate initial treatment may severely affect the prognosis of this thyroid malignancy, the appropriate use and the correct interpretation of the available diagnostic tools for MTC are of crucial importance. The purpose of the present article is to provide an easy‐to‐use guide reviewing the main issues of MTC diagnosis: (1) basal serum calcitonin; (2) stimulated serum calcitonin; (3) additional serum markers for MTC; (4) ultrasound and other imaging techniques; (5) fine‐needle aspiration (FNA) cytology; (6) calcitonin measurement on FNA washout; (7) rearranged during transfection (RET) mutations; and (8) scope of the problem.

Andrological aspects of physical exercise and sport medicine

Appropriate physical activity is one of the bases of healthy lifestyle. In fact, physical exercise and playing sport may be associated with both improvements and injury to both general and reproductive health. A biologically normal testosterone secretion appears fundamental in males to guarantee both a physiological exercise adaptation and safe sport participation. The reproductive system is highly sensitive to the effects of exercise-related stress and the reproductive hormones may both increase and decrease after different acute or chronic exercises. Exercise and sport participation may positively or negatively influence andrological health status depending on the type, intensity and duration of performed physical activity and on individual health status. In addition, prohibited substances administration (e.g. androgenic–anabolic steroids, and so forth) in competitive and non-competitive athletes represents the main cause of iatrogenic andrological diseases. Preventing and treating andrological problems in active healthy and unhealthy individuals is as important as promoting a correct lifestyle. Physicians need to be educated on the relationships between the male reproductive system and sport participation and on the great role of the pre-participation physical examination in the prevention of andrological diseases.

Cortisol, dehydroepiandrosterone sulphate and dehydroepiandrosterone sulphate/cortisol ratio responses to physical stress in males are influenced by pubertal development

To evaluate the influence of chronological age and pubertal development on the hypothalamus-pituitary-adrenal (HPA) axis response to stress, we studied the possible correlations between male pubertal characteristics and salivary cortisol (C), DHEAS and the DHEAS/ C ratio before (pre-stress) and after acute exercise-stress in young male volunteers (no. 87; 13.3±2.1 yr). In our overall study population, the mean pre-stress salivary C and DHEAS concentrations, significantly increased after exercise-related stress, whereas the DHEAS/C ratio significantly decreased. Pre-stress salivary C was positively correlated with chronological age, and after-stress salivary C concentration variations were negatively correlated with pubertal stage, mean testis volume and pre-stress salivary DHEAS. Furthermore, salivary DHEAS concentrations and the DHEAS/C ratio, before and after exercise stress, were positively correlated with chronological age, pubertal stage, pre-stress salivary testosterone (T), testis volume and body mass index (BMI). In contrast with late pubertal stages (P4, P5), young individuals at early stages of puberty (P1 to P3) showed higher C increase and lower DHEAS/C ratio after exercise-related stress. In conclusion, since C is also a mediator of stress-related negative effects on health and the DHEAS/C ratio has been hypothesized as an index for the degree to which an individual is buffered against the negative effects of stress, these data might suggest potentially increased stress-related risks at early stages of male puberty.

Calcitonin measurement in aspiration needle washout fluids has higher sensitivity than cytology in detecting medullary thyroid cancer: a retrospective multicentre study

Only few studies analysed the capability of cytology in detecting medullary thyroid cancer (MTC), and they reported a low accuracy of this diagnostic technique. Recently, calcitonin (CT) measurement in aspiration needle washout (FNA‐CT) of thyroid and neck lesions has been reported as a sensitive tool for MTC. The aim of this study is to compare the sensitivity of FNA‐CT and cytology in detecting MTC and to assess a cut‐off value of FNA‐CT for clinical practice.

Acetylsalicylic acid inhibits the pituitary response to exercise-related stress in humans.

PURPOSE Prostaglandins (PGs) modulate the activity of the hypothalamus-pituitary axis, and pituitary hormones are largely involved in the physiological responses to exercise. The purpose of this study was to analyze the effects of acetylsalicylic acid (ASA), an inhibitor of PGs synthesis, in the pituitary responses to physical stress in humans. METHODS Adrenocorticotropin (ACTH), beta-endorphin, cortisol, growth hormone (GH), and prolactin (PRL) responses to exercise were evaluated after administration of either placebo or ASA. Blood samples for hormone evaluations before (-30, -15, and 0 pre) and after (0 post, +15, +30, +45, +60, and +90 min) a 30-min treadmill exercise (75% of .VO(2max)) were taken from 12 male athletes during two exercise trials. One tablet of ASA (800 mg), or placebo, was administered two times daily for 3 d before and on the morning of each exercise-test. RESULTS The results clearly show that, compared with placebo, ASA ingestion significantly blunted the increased serum ACTH, beta-endorphin, cortisol, and GH levels before exercise (anticipatory response) and was associated with reduced cortisol concentrations after exercise. Furthermore, although no differences in the GH response to exercise were shown, a significantly reduced total PRL response to stress condition was observed after ASA. CONCLUSION ASA influences ACTH, beta-endorphin, cortisol, GH, and PRL responses to exercise-related stress in humans (preexercise activation/exercise-linked response). Even though it is not possible to exclude direct action for ASA, our data indirectly confirm a role of PGs in these responses. We have to further evaluate the nature of the preexercise endocrine activation and, because of the large use of anti-inflammatory drugs in athletes, whether the interaction between ASA and hormones might positively or negatively influence health status, performance, and/or recovery.