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Biomedical subjects

A Volpe

Publications and source records attributed to A Volpe.

At least 109 records · Page 6Linked to original sources
PubMed1998

Effect of desogestrel-containing oral contraceptives on vascular reactivity and catecholamine levels.

The modifications induced by new oral contraceptives (OC) on blood pressure, great vessel vascular reactivity by color Doppler, and catecholamine levels were investigated. Young healthy women not taking OC (n = 22; controls) or receiving, for > or = 6 months, OC containing desogestrel with either 30 micrograms (n = 14) or 20 micrograms of EE (n = 8) were enrolled. Blood pressure measured at rest in supine position was similar between controls and OC users. The pulsatility index (PI), an indirect index of resistance to blood flow, of axillary artery was significantly higher (p < 0.05) in 30 micrograms than in 20 micrograms EE OC users or controls. A similar trend, albeit not significant, was observed for the internal carotid artery PI. Norepinephrine (p < 0.01) and dopamine (p < 0.05) but not epinephrine levels, were lower in 30 micrograms EE OC users than in 20 micrograms EE OC users or controls. Thus, both 20 micrograms and 30 micrograms EE OC had no negative effect on blood pressure, but the 30 micrograms EE OC tended to increase great vessel resistance to blood flow, independently of catecholamine levels.

Adult↗
PubMed1998

Paracrine regulation of human placenta: control of hormonogenesis.

There is much evidence indicating that the human placenta plays a very important role in modulating the endocrinology of pregnancy. Placental tissue produces cytokines, hormones and growth factors that are essential in the regulation of the feto-maternal unit. The production of these substances is regulated by a network of interactions within and between intra-uterine through paracrine and/or autocrine mechanisms. Communication between the gestational intra-uterine tissues is critical for successful pregnancy, from the earliest stage of implantation until the expulsive phase of delivery. This is confirmed by the demonstration that the human placenta directly controls the release of substances such as hCG, hPL, steroid hormones and prostaglandins. Furthermore, there is evidence that intra-uterine tissues also can regulate ACTH release and have effects on the hypothalamus-pituitary-gonadal axis and the hypothalamus-pituitary-adrenal axis. The set of data reported in this article confirms that the placenta must be considered an organ that is essential for the initiation, maintenance and successful conclusion of pregnancy and that an imbalance between the complex network of placental regulating systems may cause serious gestational disorders.

Adrenocorticotropic Hormone↗
PubMed1998

Ultrasonographic patterns of polycystic ovaries: color Doppler and hormonal correlations.

Ultrasound has been used in the identification of two different morphological patterns of polycystic ovaries, namely a peripheral cystic pattern and a general cystic pattern. The aim of this study was to evaluate whether patients with the peripheral form of polycystic ovaries showed different ovarian and uterine blood flow from those with the general form, and to investigate whether there was a correlation between the forms and different hormonal parameters. Eighteen patients with the general form and 16 patients with the peripheral form of polycystic ovary underwent clinical, biochemical, gray-scale and color Doppler ultrasonographic evaluation. The parameters analyzed confirmed polycystic ovarian syndrome (PCOS) in all patients. Individual levels of plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, androstenedione and estradiol did not differ between the groups. However, there was a significantly higher LH/FSH ratio and a greater stromal echodensity in the peripheral cystic group than in the general cystic group. Doppler ultrasonography demonstrated significantly lower pulsatility index values in the intraovarian arteries of the peripheral cystic group and a higher rate of visualization of these arteries than in the general cystic group. These findings suggest that, apart from the LH/FSH ratio, the different morphological types of polycystic ovary do not reflect differences in endocrine profile. The differences in blood flow demonstrated by Doppler assessment in each case, however, showed that PCOS does not predetermine a single intraovarian blood flow pattern.

Adolescent↗
PubMed1998

Ultrasonographic and color Doppler analysis in the treatment of polycystic ovary syndrome.

OBJECTIVE: To compare the effect of a gonadotropin releasing hormone (GnRH) analog plus 'add-back' oral contraceptive (OC) therapy with OC therapy alone on the clinical and hormonal parameters that are characteristic of polycystic ovary syndrome (PCOS). DESIGN: Prospective, randomized study. SUBJECTS: Thirty PCOS patients were randomly assigned to treatment with leuprolide acetate for depot suspension plus a combined monophasic OC (Group I) or to OC alone (Group II). METHODS: Hormonal (luteinizing hormone (LH), follicle stimulating hormone (FSH), LH : FSH concentration ratio, estradiol, androstenedione, testosterone), clinical (Ferriman-Gallwey score), ultrasonographic (ovarian volume, number of subcapsular follicles, stromal score) and Doppler (uterine artery and ovarian intraparenchymal vessels' pulsatility index, ovarian stromal vascularization) parameters were evaluated during 6 months' therapy and 6 months' follow-up. RESULTS: Significant changes in all the parameters analyzed occurred as a result of therapy and the changes were more marked in the group undergoing treatment with GnRH analog plus OC. CONCLUSIONS: GnRH analog plus OC use has a more rapid and marked effect on the hormonal milieu as well as the ovarian architecture and vascularization in patients with PCOS than OC used alone. The former treatment may be a more efficient therapy for PCOS.

Adolescent↗
PubMed1998

Increased anticardiolipin antibodies are positively related to the uterine artery pulsatility index in unexplained infertility.

The objective of the study was to evaluate, in patients with unexplained infertilty, the possible relationship between anticardiolipin antibodies and indices of uterine artery Doppler measurements. A total of 46 infertile women participated in the study and underwent ovarian stimulation. Transvaginal ultrasonography and colour Doppler were performed on the day of embryo transfer and patients were divided on the basis of pulsatility index (PI): group I, PI <2.5; group II, PI 2.5-3.0; and group III, PI >3.0. On the same day that Doppler analysis took place, peripheral blood was obtained and circulating anticardiolipin antibodies were assayed. The response to ovarian stimulation was similar in the three studied groups. No significant differences in oestradiol and ultrasonographic parameters were observed between the groups. A significant increase in anticardiolipin antibodies was observed in those patients with higher resistance to flow at the level of the uterine artery. A significant relationship was found between the uterine artery PI and anticardiolipin immunoglobulin G class (F = 14.35; P = 0.001), and immunoglobulin M class (F = 5.88; P = 0.020). It is concluded that, in unexplained infertility, anticardiolipin antibodies may be involved in uterine vascular modifications and that Doppler flow analysis of uterine arteries may be an important tool in the assessment and management of ovarian stimulation.

Adult↗
PubMed1998

Influence of age and sex on serum concentrations of total dimeric activin A.

Several studies have shown that activin A is secreted in substantial amounts into the systemic circulation. The changes that occur during menstrual cycle and pregnancy suggest a correlation with reproductive function. At present, however, no definitive evidence has confirmed this pattern throughout adult life; moreover, neither the origin nor the physiological implications of this circulating growth factor have been clearly defined. The aim of the present study was to evaluate whether circulating concentrations of activin A change in adult men and women according to age and sex, and to examine the possible correlation with serum concentrations of FSH. Total dimeric activin A was measured using a specific two-site enzyme immunoassay in serum specimens collected from a cohort of normal individuals enrolled in an epidemiological survey. A group of men (n = 106) and one of women (n=151) were subdivided into six age groups (20-30, 30-40, 40-50, 50-60, 60-70 and 70-90 years). In a small group of 8 men and 11 women, serum concentrations of activin A were evaluated twice, in specimens collected at an interval of 10 years. Serum FSH concentrations were also measured in all specimens. Serum concentrations of activin A were not significantly different in men and women and showed an age-related progressive increase between 20 and 50 years of age (P<0.01, those aged 40-50 compared with those aged 20-30 years). After the age of 50 years, activin A concentrations remained in the same range of values in women, whereas they increased significantly in men, reaching peak values between 70 and 90 years (P<0.01 compared with the group aged between 20 and 50 years). From the age of 50 years, activin A concentrations were significantly greater in men compared with those in women in the corresponding age groups (P<0.001). Activin A concentrations correlated with age in men, but not in women. No significant correlation between concentrations of activin A and FSH was found in either sex. Activin A concentrations in specimens collected 10 years apart showed an increase in seven of eight men, but not in women. Finally, no significant variations of activin A concentrations were observed when fertile and postmenopausal women were compared. The present data indicate that circulating concentrations of activin A vary according to age; furthermore, men older than 50 years have greater concentrations than women. These changes, which occur irrespectively of FSH concentrations, indicate that circulating activin A is not a hormone of the reproductive axis.

Activins↗
PubMed1998

Reduction of serum citrulline levels in women at term toward the day of labor onset.

OBJECTIVE: To test the hypothesis that labor onset could be the result of a reduced release of nitric oxide (NO). STUDY DESIGN: Out of 91 consecutive healthy nulliparous women at term serum citrulline (Cit) and arginine (Arg) levels were measured at least twice in 37 subjects, by the means of HPLC with fluorometric detection. Twenty cases underwent a spontaneous onset of labor (group A) while in 17 cases labor was induced (group B) because of pregnancy prolongation or amniotic fluid reduction. RESULTS: Cit and Arg levels were unaffected by the gestational age. In group A, Cit levels undergo a progressive decrease toward the day of labor (from 32.9+/-4.7 microM/L the day - 18,-5 to 27.7+/-7.8 the day -4,0; p=0.012) whilst they remained stable in group B (from 33.3+/-7.7 to 34.2+/-9.2). No significant changes were observed in Arg levels. Cit/Arg ratio remained stable in group A whereas it showed a trend to increase in group B. CONCLUSION: These data indirectly suggest a reduced release of NO toward term. This phenomenon could play a permissive role in the spontaneous onset of labor of healthy nulliparous women.

Arginine↗
PubMed1997

The effect of transdermal 17-beta-estradiol on glucose metabolism of postmenopausal women is evident during the oral but not the intravenous glucose administration.

OBJECTIVES: To evaluate the effect of transdermal 17-beta-estradiol (50 micrograms/day) on glucose metabolism of postmenopausal women. STUDY DESIGN: A frequently sampled intravenous glucose tolerance test (FSIGT), to calculate insulin sensitivity (SI) and peripheral glucose utilization independent of insulin (SG), and an oral glucose tolerance test (75 g; OGTT), were performed in nine postmenopausal women prior to, and after 2 months of, treatment. RESULTS: Estradiol decreased insulin and increased the C-peptide/insulin ratio both during fasting (P < 0.02) and OGTT (insulin levels, P < 0.01; C-peptide/insulin ratio, P < 0.05), but not FSIGT. Glucose levels, C-peptide levels, SI and SG were not affected. CONCLUSIONS: In spite of unmodified SI, the reduction of insulin levels and the increase of the C-peptide/insulin ratio, observed during fasting and OGTT, support a beneficial effect of estradiol on glucose metabolism. This effect probably requires the interplay of estradiol with gastrointestinal factors.

Administration, Cutaneous↗
PubMed1997

L-arginine infusion decreases platelet aggregation through an intraplatelet nitric oxide release.

Nitric Oxide (NO) inhibits platelet aggregation via activation of an intraplatelet soluble guanylate cyclase which induces an increase in cyclic GMP (1). It has been also demonstrated that platelets contain a constitutive, calcium-dependent, NO synthase which is activated by collagen-induced platelet aggregation. This leads to a NO synthesis from L-Arginine (L-Arg), which in turn increases cyclic GMP and down-regulates platelet aggregation (2). In vitro administration of supraphysiological concentrations of L-Arg enhances platelet cyclic GMP levels by increasing NO production and reduces platelet aggregation. This effect is reversed by pre-incubation with NO-synthase inhibitors (3). These results indicate that the L-Arg: NO pathway plays an important role in the modulation of human platelet aggregation (4). In vivo L-Arg, when administered i.v., induces hypotension (5) and vasodilatation (6,7) in humans, and when orally supplemented reduces platelet aggregability both in hypercholesterolemic rabbits and healthy men (8,9).

Adenosine Diphosphate↗
PubMed1997

Regulation of the 24-hour rhythm of body temperature in menstrual cycles with spontaneous and gonadotropin-induced ovulation.

OBJECTIVE: To investigate the relation between gonadal steroids and the 24-hour body temperature rhythm. PATIENT(S): Nineteen normally cycling women. DESIGN: Controlled clinical study in volunteer women. SETTING: Clinical hospital. INTERVENTION(S): Eleven women were studied in the early follicular and luteal menstrual phases of cycles with spontaneous ovulation, and 8 women were studied in the early follicular, preovulatory, and luteal phases of cycles with multiple follicular development. MAIN OUTCOME MEASURE(S): Starting at 5:00 P.M., intravaginal body temperature was monitored continuously for 24 hours and its values were related to E2 and P levels. RESULT(S): Twenty-four-hour body temperature rhythm parameters were related to the P:E2 ratio. Very low P:E2 ratios in the preovulatory phase were associated with a reduced 24-hour mean and an elevated body temperature rhythm amplitude. The progressive increase in the P:E2 ratio in the early follicular and luteal phases was associated with an increase in the 24-hour mean body temperature and a decrease in the rhythm amplitude. Body temperature differences between the luteal and early follicular phases were less pronounced in cycles with multiple follicular development. CONCLUSION(S): A woman's body temperature is related to her P:E2 ratio. Even in the presence of elevated P values, alterations of this ratio may influence negatively the postovulatory rise in body temperature.

Adult↗
PubMed1997

A long-term treatment with gonadotropin-releasing hormone agonist plus a low-dose oral contraceptive improves the recovery of the ovulatory function in patients with polycystic ovary syndrome.

OBJECTIVE: To evaluate the hormonal and clinical follow-up after the suspension of a longterm therapy with GnRH-agonist (GnRH-a) plus oral contraceptive (OC) in comparison to OC alone in patients with polycystic ovary syndrome (PCOS). DESIGN: Hormonal (plasma LH, FSH, sex steroid levels) and clinical (Ferriman-Gallwey score and ultrasound) parameters were monitored at various moments during the 6 months of treatment and during the 6 months after treatment suspension. SETTING: Physiopathology of Human Reproduction, University of Modena, Italy. PATIENT(S): Thirty patients with PCOS were enrolled and randomly subdivided in two groups of 15 each. INTERVENTION(S): Group A was treated with 3.75 mg IM GnRH-a plus OC. Group B was treated only with OC. RESULT(S): Both therapeutical regimens were effective in reducing androgenic milieu, Ferriman-Gallwey score, and ovarian volume within the 6th month of treatment. However, only patients treated with GnRH-a + OC showed a normal LH:FSH ratio, adequate plasma E2 and P levels, and ovulatory cycles during the 6 months of the after treatment follow-up. Patients treated with OC alone showed no beneficial effect after the 3rd month of the follow-up. CONCLUSION(S): These data support the evidence of a higher efficacy of the combined regimen (GnRH-a + OC) than OC alone in the treatment of patients with PCOS. In addition, the former regimen is associated with recovery of normal ovulatory cycles.

Androgens↗
PubMed1997

An increased vulnerability to stress is associated with a poor outcome of in vitro fertilization-embryo transfer treatment.

OBJECTIVE: To evaluate the association between the vulnerability to stress and the treatment outcome of couples undergoing IVF-ET. DESIGN: Controlled, prospective clinical study. SETTING: The Assisted Reproduction Unit of the Department of Obstetrics and Gynecology, University of Modena. PATIENT(S): Forty-nine infertile women consecutively admitted to standard superovulation treatment. Mean age was 33.9 years, duration of infertility was 6.3 years. Reasons for assisted reproduction were mechanical factor in 22 cases, sperm problem in 9 cases, and endocrine disorder in 6 cases. In 12 cases, infertility was unexplained. More than 55% already had an IVF-ET attempt. INTERVENTION(S): The day of oocyte pick-up, subjects were submitted to Stroop Color and Word test, a task measuring the ability to cope with a cognitive stressor, involving attentional and sympathoadrenal systems. Systolic (SBP) and diastolic blood pressure, as well as heart rate (HR) were measured at baseline, during the test, and 10 minutes after the end of testing. MAIN OUTCOME MEASURE(S): The evidence of a biochemical pregnancy (beta-hCG value 12 days after ET) define the success and failure groups. RESULT(S): Sixteen women (33%) had a biochemical pregnancy, 12 also had ultrasound evidence. Eight gave birth to healthy infants. Age, education, causes, and duration of infertility were similar in the success and failure groups. The latter were more involved in a job outside home than the former. Moreover, they had a lower number of both fertilized oocytes and transferred embryos. In response to the Stroop test, every subject reported an increase of cardiovascular parameters. However, women becoming pregnant showed a lower response of both SBP and HR than women who failed. CONCLUSION(S): Both a major cardiovascular vulnerability to stress and working outside home are associated to a poor outcome of IVF-ET treatment.

Adult↗
PubMed1997

Difference of LH and FSH secretory characteristics and degree of concordance between postmenopausal and aging women.

OBJECTIVE: Several neuroendocrine changes occur at menopause and the present study aimed to verify whether the episodic release and the degree of concordance of LH and FSH differs between early and late postmenopausal women. METHODS: Postmenopausal (n = 32) women were enrolled and subdivided in two groups according to the menopausal age: group A (n = 22), patients with more than 2 but less than 5 years from the occurrence of menopause; group B (n = 10), patients with more than 15 years from the occurrence of menopause. All subjects underwent a pulsatility study (4 h, sampling every 10 min) to assess LH and FSH secretory characteristics and their degree of concordance. RESULTS: Mean +/- S.E.M. LH and FSH plasma levels were lower in older women than in postmenopausal women (P < 0.01). The secretory pattern was pulsatile for both LH and FSH and their pulse amplitudes were lower in aged women (P < 0.01). No significant difference was observed in terms of pulse frequency between the two groups. LH and FSH pulses were co-secreted in early postmenopausal women while such a concordance was lost in older women. CONCLUSIONS: Late postmenopause is characterized by the reduction of the amplitude of gonadotropin pulses in comparison to women in early postmenopause, reflecting changes of both GnRH secretion and/or pituitary responsiveness to GnRH. The age-related loss of concordance between LH and FSH pulses discloses the existence of a hidden FSH stimulating system, which drives FSH episodic release independently and more promptly than GnRH.

Aging↗
PubMed1997

Modulatory effects of a synthetic steroid (tibolone) and estradiol on spontaneous and GH-RH-induced GH secretion in postmenopausal women.

OBJECTIVE: Since hormonal replacement therapy (HRT) affects plasma GH levels, the present study aimed to verify the effect of tibolone, a synthetic steroid, on modulating spontaneous and growth hormone releasing hormone (GH-RH) induced GH secretion. METHODS: Postmenopausal women (n = 30) were enrolled and randomly subdivided in three groups (n = 10 each group): (1) treated with transdermal estradiol (50 micrograms) (Dermestrill, Rottapharm, Monza, Italy) biweekly; (2) treated with transdermal estradiol (100 micrograms) (Dermestrill, Rottapharm, Monza, Italy) biweekly; (3) treated with tibolone 2.5 mg/day (Livial, Organon Italia, Rome, Italy). Patients underwent a GH-RH test (1 microgram/kg) and 15 of them underwent to a pulsatility study before and 5 weeks after treatment. RESULTS: Mean (+ S.E.M.) GH plasma levels increased in all patients after any type of HRT. GH response to GH-RH stimulation (expressed as maximal response to GH-RH or as delta value) was similar in the three groups while significant changes occurred in spontaneous pulsatile GH release. Tibolone and both dosages of transdermal estradiol significantly reduced GH pulse frequency and increased pulse amplitude. CONCLUSIONS: The reduced plasma GH levels observed during postmenopause are probably related to a reduced endogenous GH-RH and not to a reduced pituitary ability to respond to GH-RH. In addition tibolone, as well as transdermal estradiol, are effective in restoring the spontaneous GH episodic release.

Administration, Cutaneous↗
PubMed1997

Colour Doppler changes and thromboxane production after ovarian stimulation with gonadotrophin-releasing hormone agonist.

The objective of this study was to evaluate the Doppler flow variations which occur following the use of different protocols of ovarian stimulation in an IVF programme, and to investigate the thromboxane production by cultured endometrial cells and its influence on embryo implantation. A total of 60 patients underwent three different ovarian stimulation protocols: long gonadotrophin-releasing hormone agonist (GnRH-a), short GnRH-a and no GnRH-a. Transvaginal ultrasonography and colour Doppler analysis were performed before and during the treatment. On the day that the Doppler examination took place, luteinizing hormone, follicle stimulating hormone, plasma oestradiol and thromboxane concentrations were assayed. On the day of oocyte retrieval, endometrial cells were collected and cultured, and their thromboxane production evaluated. No significant differences in hormonal, ultrasonographic or Doppler parameters were observed between the three groups. Ten out of 56 patients who had a successful embryo transfer became pregnant. In the group of pregnant women the pulsatility index values of both uterine and spiral arteries was lower than in non-pregnant patients, and was associated with significantly lower thromboxane concentrations from cultured endometrial cells. It is concluded that thromboxane plays a role in embryo implantation, and that Doppler flow analysis of uterine and spiral arteries in infertile patients may be important in the management of ovarian stimulation.

Adult↗
PubMed1997

Effect of triclosan on the subgingival microbiota of periodontitis-susceptible subjects.

The present study evaluated the long-term effect of (i) meticulous self-performed, supragingival plaque control and (ii) the use of a triclosan/copolymer containing dentifrice in adult subjects susceptible to destructive periodontitis. 40 individuals were recruited into the trial. 3-5 years prior to the baseline examination, they had all been treated by nonsurgical means- for advanced periodontal disease. During the subsequent maintenance phase, all subjects had at different time intervals exhibited sites with recurrent periodontitis. At a baseline examination, 6 surfaces per tooth were examined regarding bleeding on probing, probing pocket depth, and probing attachment level. The deepest pocket site in each quadrant (i.e. 4 sites per subject) was selected and samples of the subgingival bacteria were taken. At baseline, all volunteers received detailed information on proper oral hygiene techniques. This information was repeated on an individual need basis during the course of the subsequent 36-months. No professional subgingival therapy was delivered between the baseline and the 36-month examinations. The subjects were randomly distributed into 2 equal groups of 20 individuals each, 1 test and 1 control group. The members of the test group were supplied with a fluoridated dentifrice containing triclosan/copolymer (Total, Colgate), while the controls received a corresponding dentifrice but without triclosan/copolymer. The findings demonstrated that in subjects with advanced and recurrent periodontitis, carefully practiced supragingival plaque control had some effects on the subgingival microbiota, but also that this was insufficient to prevent disease progression. In a corresponding group of subjects, however, who used a triclosan/copolymer dentifrice, the subgingival microbiota was reduced in both quantitative and qualitative terms and recurrent periodontitis was almost entirely prevented.

Actinomyces↗