Biomedical subjects

A Volpe

Publications and source records attributed to A Volpe.

At least 91 records · Page 5Linked to original sources

PubMed1999

Rhythmic variation in the rate of ectopic pregnancy throughout the year.

OBJECTIVE: This study was conducted to determine whether the incidence of ectopic pregnancy follows a seasonal rhythm of occurrence. STUDY DESIGN: A retrospective analysis was performed on 15,639 pregnancies reported in a single department in 5.5 years (January 1992-June 1997). For each pregnancy the time of conception was estimated from medical records. Frequencies of conceptions that terminated in birth, spontaneous abortion, legally induced abortion, and ectopic pregnancy were distributed across the 12-month period. RESULTS: Total pregnancy showed a seasonal rhythm of occurrence, with peak values in March. The rate of ectopic pregnancy showed a rhythm with 2 peaks, in June and December. Nadirs were coincident with the peak and nadir of total conceptions and also with the equinoxes. Spontaneous abortions tended to show a rhythm the inverse of that of ectopic pregnancy. CONCLUSIONS: These data show an influence of the seasons on the rate of ectopic pregnancy, which may have implications for both the understanding of ectopic pregnancy's causative mechanisms and its prevention.

Abortion, Spontaneous↗

PubMed1999

Biometrical threshold of biparietal diameter for certain fetal sex assignment by ultrasound.

OBJECTIVES: The aim of this study was to establish the biometric threshold of biparietal diameter (BPD), assumed to be an independent variable of gestational age, at which 100% accuracy in the assessment of fetal sex by ultrasonography is achievable. METHODS: Transvaginal and/or transabdominal sonography was used for detecting the 'sagittal sign' as a marker of fetal sex in 385 fetuses with BPD between 18 and 29 mm. The results of ultrasound examination were compared with sex at birth or with karyotype obtained from amniotic fluid cells or chorionic villus sampling. RESULTS: Fetal sex assignment was feasible in 337 of 385 cases (87.5%). Of the 312 fetuses with known fetal sex outcome, 164 were males and 148 were females. An accuracy rate of 100% was achieved when a BPD of > or = 23 mm was obtained. CONCLUSION: This study provides important information about the earliest stage of fetal development, expressed in terms of BPD, at which a diagnosis of fetal sex can be made with 100% accuracy.

Biometry↗

PubMed1999

Hormonal replacement therapy and urinary problems as evaluated by ultrasound and color Doppler.

OBJECTIVE: To determine how hormone replacement therapy modifies bladder vascularization and urinary symptoms. STUDY DESIGN: Twenty-eight postmenopausal women with urinary symptoms (day-time frequency > 8; nocturia > 1; urgency and/or dysuria) were analyzed before and after 1, 3 and 6 months of hormone replacement therapy. The patients underwent transvaginal ultrasound evaluation of the pelvic organs and endometrial and bladder wall thickness. Transvaginal color Doppler analysis of blood flow impedance of the uterine and intramural bladder wall arteries was performed in all cases. RESULTS: Hormone replacement therapy significantly increased bladder wall and endometrial thickness. This result was associated with significant improvements in uterine and bladder wall vascularization. Urinary symptoms also improved during therapy. CONCLUSION: The study of bladder wall thickness and vascularization provides additional information regarding the beneficial effect of hormone replacement therapy on lower urinary tract symptoms in postmenopausal women.

Aged↗

PubMed1999

Polycystic ovary syndrome: it is always bilateral?

OBJECTIVE: To evaluate whether patients with unilateral polycystic ovary showed different ovarian and uterine blood flow from those with bilateral polycystic ovaries, and to investigate whether there was a correlation between the ultrasonographic aspect and different hormonal parameters. DESIGN: An observational study. SUBJECTS: Sixteen patients with unilateral polycystic ovary and twenty patients with bilateral polycystic ovaries underwent clinical, biochemical, gray-scale and color Doppler ultrasonographic evaluation. METHODS: The following parameters were evaluated: hormonal (luteinizing hormone (LH), follicle stimulating hormone (FSH), LH/FSH concentration ratio, estradiol, prolactin, androstenedione, testosterone), clinical (body mass index, Ferriman-Gallwey score), ultrasonographic (ovarian volume, number and distribution of subcapsular follicles, stromal score) and Doppler (uterine artery and intraparenchymal vessel pulsatility index, ovarian stromal vascularization), in oligomenorrheic patients in the early follicular phase (cycle days 3-5) or in amenorrheic patients at random. RESULTS: Significantly higher androstenedione plasma levels and LH/FSH concentration ratios were observed in bilateral polycystic ovaries. In unilateral polycystic ovaries, gray-scale and color Doppler ultrasonography showed different features in the affected and the unaffected ovary, similar to the appearance of a polycystic and normal ovary, respectively. CONCLUSION: Polycystic ovary syndrome does not predetermine a single ultrasonographic and Doppler pattern.

Adolescent↗

PubMed1999

Diurnal variation of semen quality in human males.

The possibility of a diurnal variation in semen quality was tested in 54 human males attending our infertility clinic. Of the enrolled subjects, 24 were normozoospermic and 30 were suffering from oligo- and/or asthenozoospermia. Seminal fluid was collected by masturbation twice by each subject, once in the morning (7:00-7:30 a.m.) and once in the afternoon (5:00-5:30 p.m.). Abstinence from sexual intercourse for 3-4 days before each of the two collections was requested. Semen parameters were evaluated independently by two biologists before and after pellet swim-up. Beside similar macroscopic parameters, specimens collected in the afternoon showed a higher number (P < 0.01) and concentration (P < 0.01) of spermatozoa. Also, immediately (P < 0.05), and at 1 h (P < 0.02) and 2 h (P < 0.01) after pellet swim-up, the number of spermatozoa with progressive linear motility was higher in the afternoon than in the morning. These data are the first documenting a diurnal rhythm in sperm quality which may contribute to the reported variability in semen parameters, and may prove useful for spontaneous and assisted conceptions.

Adult↗

PubMed1999

Effect of ovarian suppression on glucose metabolism of young lean women with and without ovarian hyperandrogenism.

Gonadal steroids are believed to influence glucose metabolism, oestrogens inducing an improvement and androgens or progestins a deterioration. At baseline and after 3 months of ovarian suppression with a gonadotrophin-releasing hormone analogue (GnRHa: goserelin depot 3.75 mg/28 days), glucose metabolism was evaluated in eight lean women affected by ovarian hyperandrogenism (PCOS) and six age-weight-matched non-hyperandrogenic women (controls) by using both an oral glucose tolerance test (75 g; OGTT) and the minimal model method. The latter method allows calculation of peripheral insulin sensitivity (Si) and glucose dependent glucose utilization (Sg). In PCOS, higher fasting concentrations (P < 0.05) of insulin and C-peptide, and lower Sg (P < 0.05) and Si (P < 0.01) were found. GnRHa did not significantly modify glucose metabolism of controls, while in women with PCOS it decreased fasting glucose (P < 0.05) and significantly increased Si (P < 0.03) up to control values. The present data indicate that strong suppression of ovarian activity improves Si in lean women with PCOS, while it is without relevant effects on glucose metabolism of non-hyperandrogenic women.

Adult↗

PubMed1999

Adjuvant L-arginine treatment for in-vitro fertilization in poor responder patients.

The objective of the present study was prospectively and randomly to evaluate the role of L-arginine in improving uterine and follicular Doppler flow and in improving ovarian response to gonadotrophin in poor responder women. A total of 34 patients undergoing assisted reproduction was divided in two groups according to different ovarian stimulation protocols: (i) flare-up gonadotrophin-releasing hormone analogue (GnRHa) plus elevated pure follicle stimulating hormone (pFSH) (n = 17); and (ii) flare-up GnRHa plus elevated pFSH plus oral L-arginine (n = 17). During the ovarian stimulation regimen, the patients were submitted to hormonal (oestradiol and growth hormone), ultrasonographic (follicular number and diameter, endometrial thickness) and Doppler (uterine and perifollicular arteries) evaluations. Furthermore, the plasma and follicular fluid concentrations of arginine, citrulline, nitrite/nitrate (NO2-/NO3-), and insulin-like growth factor-1 (IGF-1) were assayed. All 34 patients completed the study. In the L-arginine treated group a lower cancellation rate, an increased number of oocytes collected, and embryos transferred were observed. In the same group, increased plasma and follicular fluid concentrations of arginine, citrulline, NO2-/NO3-, and IGF-1 was observed. Significant Doppler flow improvement was obtained in the L-arginine supplemented group. Three pregnancies were registered in these patients. No pregnancies were observed in the other group. It was concluded that oral L-arginine supplementation in poor responder patients may improve ovarian response, endometrial receptivity and pregnancy rate.

Adult↗

PubMed1999

Physiological doses of estradiol decrease nocturnal blood pressure in normotensive postmenopausal women.

The effect of a 2-mo treatment with transdermal estradiol (50 microgram/day) versus placebo on 24 h of blood pressure rhythm was investigated in 18 normotensive healthy postmenopausal women. Whereas daytime blood pressure was not modified, nighttime blood pressure was reduced by estradiol. Estradiol magnified the nocturnal decrement of systolic (14.3 +/- 7.2 vs. 9.8 +/- 6.7 mmHg, P = 0. 0033), diastolic (11.6 +/- 5.0 vs. 7.5 +/- 7.3 mmHg, P = 0.028), and mean (10.8 +/- 5.6 vs. 7.2 +/- 4.5 mmHg, P = 0.011) blood pressure. As a consequence, the 24-h rhythm of mean blood pressure was restored in 50% of the subjects (P = 0.045) in whom it was absent and was amplified in the remaining 50% of the subjects. Body mass index was an independent determinant of blood pressure values being directly related to the amplitude of the 24-h mean blood pressure rhythm (r2 = 0.38; P = 0.0067). In normotensive postmenopausal women, physiological doses of estradiol amplify the nocturnal decline of blood pressure.

Blood Pressure↗

PubMed1999

Doppler, ultrasonographic and endocrinological environment with regard to the number of small subcapsular follicles in polycystic ovary syndrome.

The aim of this study was to evaluate how, in patients with polycystic ovary syndrome, the number of small subcapsular follicles correlates with uterine and ovarian blood flow and with specific hormonal parameters. At an ultrasonographic evaluation, 30 patients with polycystic ovary syndrome showed 5-10 (group I; n = 14) or > 10 (group II; n = 16) small follicles. These patients underwent ultrasonographic (ovarian volume and stroma echodensity; number, diameter and distribution of follicles) and color Doppler (uterine and intraovarian vessels) analyses, and hormonal assay. In group II, significantly lower pulsatility index values than in group I were observed in the ovarian stromal arteries. The Ferriman-Gallwey score, plasma androstenedione level and luteinizing hormone/follicle stimulating hormone (LH/FSH) ratio results were significantly higher in group II than in group I. Androstenedione plasma levels correlated with the number of small follicles. Furthermore, the LH/FSH ratio correlated with both the number of small follicles and the stromal artery pulsatility index. The combined assessment of ovarian morphology by transvaginal ultrasound and color Doppler may provide insight into the pathological state of polycystic ovary syndrome.

Adult↗

PubMed1999

Color Doppler and hormone replacement therapy: the role of thromboxane and plasma viscosity.

The aim of the study was to evaluate the plasma thromboxane and plasma viscosity in relation with Doppler flow parameters in postmenopausal patients treated with hormone replacement therapy. Thirty-two postmenopausal (follicle-stimulating hormone > 40 IU/l and estradiol < 100 pmol/l) women (mean age +/- SD, 54.7 +/- 2.9 years) participated in the study and were submitted to continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate every second month. Doppler resistances at the level of the uterine and internal carotid arteries, thromboxane plasma levels and plasma viscosity were analyzed in basal condition and after 1, 3 and 6 months. During hormone supplementation, the pulsatility index significantly decreased at the level of the analyzed arteries. Similarly, plasma thromboxane levels and plasma viscosity were significantly reduced. Significant correlations were found between thromboxane plasma concentrations, plasma viscosity and uterine artery resistances. Thus hormone replacement therapy seems to be responsible for both direct and indirect modifications at the level of the vessel wall physiology.

Blood Viscosity↗

PubMed1999

Uterine and cerebral vascularization in postmenopausal women treated with hormone-replacement therapy.

The effects of hormone-replacement therapy on the Doppler flow parameters of the ophthalmic artery in postmenopausal women were studied and compared with those registered at the level of the internal carotid and uterine arteries. Fifty-seven postmenopausal patients were submitted to continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate. During the estrogen phase of hormone-replacement therapy all patients underwent (at 1, 3 and 6 months after the beginning of hormone-replacement therapy) transvaginal ultrasonographic evaluation of the pelvic organs and of endometrial thickness. On the same day, they underwent color Doppler analysis of the blood flow impedance of the uterine, internal carotid and ophthalmic arteries. Estradiol plasma concentrations were assayed on the day that ultrasonographic and Doppler examinations took place. The pulsatility index of all the arteries improved, from baseline values, during the therapy and attained stable values compared to those after the first month of treatment. Furthermore, at the level of the internal carotid and ophthalmic arteries, a significant increase of the peak systolic blood flow velocity (Vmax) was observed over the 6 months of therapy. Doppler studies of the ophthalmic artery are capable of affording specific and precise pathophysiologic information to assess peripheral intracranial blood flow variations. Furthermore, such studies may be useful in monitoring hormone-replacement therapy effects on cerebral perfusion.

Administration, Cutaneous↗

PubMed1999

24-hour ambulatory blood pressure monitoring: a comparison between transdermal glyceryl-trinitrate and oral nifedipine.

The objective of the present study is to compare the effectiveness of transdermal glyceryl-trinitrate versus oral nifedipine in lowering blood pressure in patients affected by pregnancy-induced hypertension (PIH). Thirty-six consecutive pregnant women have been evaluated at different gestational ages after the diagnosis of PIH or preeclampsia (PE). After a 24-h ambulatory blood pressure monitoring, patients were allocated to three groups: those receiving oral nifedipine and those receiving transdermal glyceryl-trinitrate in a continuous (24 h/day) or intermittent (16 h/day) administration. A second blood pressure monitoring was performed after 2 weeks of treatment. Systolic and diastolic blood pressure were compared by using the Cosinor method looking at mesor, amplitude, and acrophase. Baseline systolic and diastolic blood pressure was similar among the three groups. Neither the transdermal glyceryl-trinitrate administered for 24 or 16 h nor oral nifedipine affected systolic and diastolic blood pressure. Analysis of variance showed that the posttreatment values were similar among the groups. Further studies are needed to verify the possible use of transdermal glyceryl-trinitrate as an antihypertensive drug during pregnancy.

Administration, Cutaneous↗

PubMed1999

Oral contraceptives and vascular reactivity of great vessels in women.

Blood pressure and great vessel vascular reactivity, evaluated by color Doppler ultrasound, were investigated in users of third-generation oral contraceptives (n = 18) compared to non-users, who were studied either in the follicular (n = 8) or in the luteal (n = 10) phase of the menstrual cycle. Blood pressure measured at rest in the supine position, evaluated both in the follicular phase and in the luteal phase, was similar between oral contraceptive users and non-users. The pulsatility index (an indirect index of resistance to blood flow) of both the internal carotid artery and the axillary artery was similar in control women studied in the follicular phase and in the luteal phase. By contrast, in users of oral contraceptives, pulsatility index values of the internal carotid artery tended to be higher, whilst those of the axillary artery were significantly higher, than those of women in either the follicular phase (p < 0.01) or the luteal phase (p < 0.025). In conclusion, new third-generation oral contraceptives do not have a significant impact on blood pressure control, but still tend to increase vascular resistance to blood flow, particularly in areas more involved in the regulation of blood pressure, for example the axillary artery.

Adult↗

PubMed1999

Variations of cardiac performance and inotropism in healthy postmenopausal women treated with estroprogestin replacement therapy.

OBJECTIVE: The aim of the present study was to evaluate possible variations in cardiac hemodynamic parameters related to the natural changes of ovarian estrogen production. METHODS: Forty postmenopausal women aged 52.7 +/- 4.6 years, randomized into two groups (20 patients in each group) according to the administration (group A) or not (group B) of estroprogestin replacement therapy (ERT), were examined using thoracic electrical bioimpedence. RESULTS: After 6 months of therapy, we observed the following: (1) the mean end-diastolic index was significantly higher in group A than in group B (70.27 and 57.13 mL/m2, respectively) (p < 0.05); (2) the mean acceleration index, indicator of heart contractility, and the mean cardiac index rate, indicators of cardiac performance, were significantly higher in group A than in group B (mean, 1.35 vs. 0.76 s [p < 0.01] and mean, 3.22 vs. 2.34 L/min/m2 [p < 0.05], respectively); and (3) the patients treated with ERT showed systemic vascular resistance index values significantly lower than the controls (mean, 2280 vs. 3150 fOhm/m2 [p < 0.01]), achieving standard levels after 6 months of therapy. Furthermore, the acceleration index showed a significant increase, within group A, between the third and sixth month of ERT (0.91 vs. 1.35 s [p < 0.05]). CONCLUSIONS: Our findings suggest that postmenopausal women treated with a 6-month course of ERT have significantly improved end-diastolic index, heart contractility index, cardiac index, and systemic vascular resistance, whereas 3 months of ERT does not seem to induce the same effects. In our study, thoracic electrical bioimpedence was shown to be a sensitive and specific method of analysis with a very low cost of administration.

Adult↗

PubMed1999

Effect of L-arginine load on platelet aggregation: a comparison between normotensive and preeclamptic pregnant women.

BACKGROUND: In the present study we hypothesized that a derangement of the L-arginine-nitric oxide system could be involved in the development of the hypercoagulative status found during preeclampsia. In order to verify such hypothesis we have compared the effects of nitric oxide substrate, L-arginine on platelet aggregation. Moreover, we have also measured the L-citrulline plasma levels as a stochiometric metabolite resulting from the conversion L-arginine to nitric oxide. METHODS: Nine preeclamptic women and 11 normotensive pregnant women were enrolled for the study. Subjects were infused with saline and with 30gr of L-arginine. Blood samples were drawn during the saline infusion (30 min), during L-arginine administration (30 min) and 30 min thereafter. ADP and collagen-induced platelet aggregation was studied as per Born with a dual-channel aggregometer (Chrono-Log, Mascia Brunelli, Italy) and L-citrulline was measured by HPLC. RESULTS: In normotensive women the infusion significantly decreased ADP and collagen-induced aggregation after 15 minutes of L-arginine load; whereas no effects were observed in preeclamptic women. Similarly in normotensive but not in preeclamptic women L-arginine load was able to increase L-citrulline plasma levels. CONCLUSIONS: In normotensive women the in vivo L-arginine administration decreases platelet aggregation with an increase of L-citrulline plasma levels. On the contrary, no effects were observed in preeclamptic women. These findings confirm that a hypercoagulative status characterizes preeclampsia and that such phenomenon could be explained by a derangement of the platelet L-arginine-nitric oxide pathway.

Adenosine Diphosphate↗

PubMed1999

Hepatitis C virus-RNA, immunoglobulin M anti-HCV and risk factors in haemodialysis patients.

In order to evaluate hepatitis C virus-RNA (HCV-RNA), immunoglobulin M (IgM) anti-HCV and risk factors in haemodialysis patients, 180 subjects (45 HCV negative and 135 HCV positive) were studied. Sex, age, duration of dialysis, number of transfusions and ALT were also considered. HCV-RNA was determined by the Amplicor HCV test, and IgM anti-HCV by the Abbott HCV IgM EIA. These markers were present in 40% and 30.4% of anti-HCV positive subjects. The agreement between the two tests employed was 77%. The results showed a close association between HCV-RNA and IgM anti-HCV with abnormal ALT levels and between HCV-RNA and the number of transfusions. Both of these markers were different when correlated with age and time on dialysis, respectively. Therefore, IgM anti-HCV may also serve as a serological marker of HCV infection and a complementary marker of virus replication.

Adult↗

PubMed1999

Effects of fluoride toothpaste on etched enamel of orthodontic patients.

OBJECTIVE: To investigate the effects of fluoride toothpaste on acid-etched enamel by means of a scanning electron microscope. METHODS: Permanent first premolars extracted for orthodontic reasons were etched with 37% H3PO4. They were divided into two groups in pairs of contralateral teeth. Group 1 was treated with fluoride toothpaste slurry; Group 2 was treated with deionized water. Treatment time was three weeks (one hour, 3 times a day). RESULTS: At the conclusion of the experiment, large amounts of precipitate were observed on the enamel surface of the teeth that were treated with fluoride toothpaste slurry. The etched structures were no longer evident and the enamel surface was smooth. The acid resistance of the teeth was significantly enhanced. However, clearly etched enamel structures were visible on the enamel surface of the teeth that were treated with deionized water. CONCLUSION: Fluoride toothpaste could promote the remineralization of etched enamel and enhance its resistance to acid attack.

Acid Etching, Dental↗

PubMed1998

Diurnal rhythms of labor and delivery in women: modulation by parity and seasons.

OBJECTIVES: Our purpose was to evaluate in women the diurnal (24 hour) rhythms of the onset of labor and time of delivery and their modulation by parity and seasons. STUDY DESIGN: A retrospective analysis was performed on 15,910 at term deliveries of single fetuses with noninduced labor. RESULTS: A diurnal rhythm of labor onset, with peak frequency at 8 PM and 9 AM was observed in nulliparous women but not in multiparous women. No diurnal rhythm of labor length was detectable. A diurnal rhythm of delivery, with peak values at 2 PM was evident in nulliparous but not in multiparous women. In nulliparous women the two acrophases of the diurnal rhythm of labor onset were closer in summer (10 hours) than in winter (13 hours). The acrophase of the diurnal rhythm of delivery progressively shifted to earlier hours from winter (5 PM) to summer (1 PM). CONCLUSIONS: These data show the attenuation of the diurnal rhythms of labor and delivery in multiparous women and their modulation by seasons.

Circadian Rhythm↗