Biomedical subjects

A M Morelli

Publications and source records attributed to A M Morelli.

4 recordsLinked to original sources

PubMed2005

Testosterone and sexual activity.

Male sexual activity is characterized by a synchronization of sexual desire arising in the brain and its transmission to the periphery, resulting in penile tumescence necessary for sexual intercourse. Testosterone (T) has been claimed for so long as a pivotal hormone in regulating male sexual function, acting both at central and peripheral level. We believe that T is indeed the main synchronizer of sexual activity regulating libido and enzymes as nitric oxide synthase (NOS) and phosphodiesterase type 5 (PDE5), which are crucial for the erectile process. In fact, NOS increases cyclic guanosine monophosphate (cGMP) levels, while PDE5 reduces it. Because T positively controls both the initiation and the end of the penile erection, its net effect on erection is null. In fact, penile erections are often present even without T. The main action of T is to timely adjust the erectile process as a function of sexual desire, therefore finalizing erections to sex.

Animals↗

PubMed1995

Evidence for bioeffects of LY 139478 on the human pre-osteoclastic cell line FLG 29.1.

LY 139478, the hydrochloride salt of LY 117018, is a member of the nonsteroidal antiestrogens, benzothiophene derivatives, described to be full estrogen agonists in bone acting via an estrogen receptor-mediated mechanism. However, the cellular actions of these compounds on bone remodelling need to be established. To investigate the "in vitro" properties of LY 139478 on osteoclast precursors, the human pre-osteoclastic cell line FLG 29.1 was examined for evidence of bioeffects of this compound. Binding studies with tritiated 17 beta-estradiol (17 beta E2) demonstrated that the relative potency of LY 139478 in inhibiting estrogen binding to its receptor was equal to that of 17 beta E2. Significant (p < 0.05) dose-dependent inhibition of cell growth was induced by LY 139478 at 10 nM, 100 nM and 1 microM. Calcitonin-induced cAMP accumulation was significantly increased by low (1 pM) and high (1 microM) doses of both 17 beta E2 and the compound with a dose-dependent response. Differently than estrogen, LY 139478 at high dose significantly reduced IL-6 release by these cells. In addition, pharmacological doses of both 17 beta E2 and LY 139478 activated apoptotic cell death. These findings show that the benzothiophene-derived LY 139478 acts directly on the human pre-osteoclastic cell line FLG 29.1 as an estrogen agonist.

Bone Marrow Cells↗

PubMed1991

Use of a synthetic soluble bilirubin derivative to assess interference in creatinine measurements.

In assessing interference from bilirubin, the use of a synthetic soluble derivative (ditaurobilirubin, DTB) is recommended as a surrogate for the natural conjugates (Bc). We compared the interference effect of unconjugated bilirubin (Bu), Bc, and DTB, using six mechanized methods for serum creatinine measurement. No significant interference was noted in methods that include removal of proteins or in an enzymatic method involving NADH oxidation. Heavy (negative) interference was observed in an alkaline picrate method, and in direct enzymatic methods based on hydrogen peroxide measurement: interference was always more pronounced in the presence of the two soluble derivatives (Bc and DTB), whose interference was of the same magnitude. These results point out the utility of testing for bilirubin interference by using soluble derivatives, in addition to Bu, and suggest the feasibility of using DTB as a surrogate for Bc for this purpose.

Bilirubin↗

PubMed1990

Importance of using soluble derivatives in assessing bilirubin interference: the example of gamma-glutamyltransferase.

In assessing possible in vitro interference from bilirubin on analytical methods, different results are to be expected from using either unconjugated (uB) or conjugated (cB) bilirubin as test materials, because of their different solubilities. In vitro interference of a synthetic soluble bilirubin derivative (ditauro-bilirubin, dtB) on gamma-glutamyltransferase activity measurement has been studied, in comparison with uB. In three out of five analytical methods/systems for the measurement of the enzyme activity, significantly higher (negative) interference was observed in the presence of the soluble derivative. Whichever the mechanism for the observed effect, the opportuneness of using soluble derivatives in order to assess bilirubin interference is pointed out: pathological serum specimens, submitted for laboratory investigations, are indeed frequently loaded with soluble bilirubin conjugates.

Bilirubin↗