Marcos Sampaio
Universidade Federal de Minas Gerais
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Featured researches published by Marcos Sampaio.
Reproductive Biomedicine Online | 2002
Selmo Geber; Daniela Parreiras Ferreira; Luis Felipe Víctor Spyer Prates; Liana Sales; Marcos Sampaio
Endometriosis affects 2-50% of women at reproductive age. Surgery is an option for treatment, but there is no convincing evidence that it promotes a significant improvement in fertility. Also, the removal of ovarian endometrioma might lead to a reduction in the follicular reserve and response to stimulation. Therefore, the aim of this study was to evaluate the effect of previous ovarian surgery for endometriosis on the ovarian response in assisted reproduction treatment cycles and its pregnancy outcome. A total of 61 women, with primary infertility and previously having undergone ovarian surgery for endometriosis, who had received 74 IVF/intracytoplasmic sperm injection (ICSI) cycles, were studied (study group). A further 74 patients with primary infertility who underwent 77 IVF/ICSI cycles within#10; the same period of time, at the same clinic and without previous ovarian surgery or endometriosis were studied as a control group. Patients were matched for age and treatment performed. Patients </=35 years with previous ovarian surgery had fewer retrieved oocytes than the patients in the control group (P = 0.049). The number of ampoules used for ovulation induction, duration of folliculogenesis; (days), number of follicles and fertilization rate was similar in both groups. The same was observed for pregnancy rates, with 24 patients (53.3%) having had previous ovarian surgery and 27 (56.2%) in the control group becoming pregnant. Patients >35 years with previous ovarian surgery needed more ampoules for ovulation induction (P = 0.017) and had fewer follicles and oocytes than women in the control group (P = 0.001). Duration of folliculogenesis was similar in both groups, as was fertilization rate. A total of 10 patients achieved pregnancy in the study group (34.5%) and 14 (48.3%) in the control group. Although a lower pregnancy rate was observed in patients who had undergone previous ovarian surgery, this difference was not statistically significant (P = 0.424). In conclusion, ovarian surgery for the treatment of endometriosis reduces the ovarian outcome in IVF/ICSI cycles in women >35 years old, and might also decrease pregnancy rates. Therefore, for infertile patients, non-surgical treatment might be a better option to avoid reduction of the ovarian response.
Journal of Physics G | 2012
G. Gazzola; H. G. Fargnoli; A. P. Baêta Scarpelli; Marcos Sampaio; M. C. Nemes
We consider an effective model formed by usual QED (minimal coupling) with the addition of a nonminimal Lorentz-violating interaction (proportional to a fixed 4-vector b?) which may radiatively generate both CPT even and odd terms in the pure gauge sector. We show that gauge invariance from usual QED, considered as a limit of the model for b? ? 0, plays an important role in the discussion of the radiatively induced Lorentz-violating terms at one-loop order. Moreover, despite the nonrenormalizability of the (effective) model preventing us from readily extending our discussion to higher orders, it is still possible to display the general form of the breaking terms of the photon sector in the on-shell limit organized in powers of b? which in turn can be considered as a small expansion parameter.
Physical Review D | 2001
A. P. Baêta Scarpelli; M. C. Nemes; Marcos Sampaio
We extend an implicit regularization scheme to be applicable in the
Reproductive Biomedicine Online | 2007
Selmo Geber; Ana Carolina Moreira; Sálua Oliveira Calil de Paula; Marcos Sampaio
n
European Physical Journal C | 2008
A. P. Baêta Scarpelli; Marcos Sampaio; M. C. Nemes; B. Hiller
-dimensional space-time. Within this scheme divergences involving parity violating objects can be consistently treated without recoursing to dimensional continuation. Special attention is paid to differences between integrals of the same degree of divergence, typical of one loop calculations, which are in principle undetermined. We show how to use symmetries in order to fix these quantities consistently. We illustrate with examples in which regularization plays a delicate role in order to both corroborate and elucidate the results in the literature for the case of CPT violation in extended
Journal of Assisted Reproduction and Genetics | 2002
Selmo Geber; Liana Sales; Marcos Sampaio
QED_4
Physics Letters B | 2006
Leonardo A.M. Souza; Marcos Sampaio; M. C. Nemes
, topological mass generation in 3-dimensional gauge theories and the Schwinger Model and its chiral version.
European Physical Journal C | 2017
C. Gnendiger; A. Signer; D. Stöckinger; Alessandro Broggio; A. L. Cherchiglia; Felix Driencourt-Mangin; A. R. Fazio; B. Hiller; Pierpaolo Mastrolia; Tiziano Peraro; R. Pittau; G. M. Pruna; German Rodrigo; Marcos Sampaio; German F. R. Sborlini; W. J. Torres Bobadilla; F. Tramontano; Y. Ulrich; A. Visconti
The use of progesterone for luteal phase support has been demonstrated to be beneficial in assisted reproduction cycles using gonadotrophin-releasing hormone analogues (GnRHa). Two micronized progesterone preparations are available for vaginal administration: capsules and gel. The objective of this study was to compare the efficacy of these two forms for luteal phase support in assisted reproduction cycles. A total of 244 couples undergoing IVF/intracytoplasmic sperm injection cycles were included in the study and were randomly allocated (sealed envelopes) into two groups: group 1 (122) received vaginal capsules of 200 mg of micronized progesterone (Utrogestan), 3 times daily, and group 2 (122) received micronized progesterone in gel (Crinone 8%), once daily. Both groups received progesterone for 13 days beginning day 1 after oocyte retrieval, continuing until the pregnancy test was performed and until 12 weeks of pregnancy. Groups were compared by clinical data and assisted reproduction results and had similar ages and causes of infertility. Although the pregnancy rate was higher for those receiving progesterone gel than capsules (44.26 and 36.06% respectively), this difference was not statistically significant. The study showed that vaginal progesterone gel and capsules used for luteal phase support in assisted reproduction cycles with long protocol GnRHa result in similar pregnancy rates.
Journal of High Energy Physics | 2003
David Carneiro; Marcos Sampaio; M. C. Nemes; Antonio Paulo Baêta Scarpelli
The radiative induction of the CPT and Lorentz violating Chern–Simons (CS) term is reassessed. The massless and massive models are studied. Special attention is given to the preservation of gauge symmetry at higher orders in the background vector bμ when radiative corrections are considered. Both the study of the odd and even parity sectors of the complete vacuum polarization tensor at one-loop order and a non-perturbative analysis show that this symmetry must be preserved by quantum corrections. As a complement we obtain the result that transversality of the polarization tensor does not fix the value of the coefficient of the induced CS term.
International Journal of Theoretical Physics | 2006
Marcos Sampaio; A. P. Baêta Scarpelli; J. E. Ottoni; M. C. Nemes
AbstractPurpose: Compare the efficacy and safety of two different GnRHa, used for pituitary suppression in IVF cycles. Methods: A total of 292 patients using depot goserelin (Group 1) and 167 using daily leuprolide acetate (Group 2) were compared. Days required to achieve pituitary function suppression, duration of ovarian stimulation, total dose of HMG, number of aspirated follicles, number of oocytes retrieved, and presence of functional ovarian cyst were analyzed. Results: The time taken to achieve downregulation was similar. The mean number of ampoules used for superovulation was higher in Group 1; however, this difference was observed only for patients >40 years old that started GnRHa in the follicular phase. There was no difference between the two groups in the duration of superovulation, in the number of follicles aspirated, and the number of oocytes retrieved. In the group of patients with >40 years the incidence of ovarian cysts was higher in Group 2. Conclusions: Both routes of GnRHa have similar effects for pituitary suppression and ovulation induction in assisted reproductive technology. Therefore the long-acting GnRHa is an excellent option, as only a single subcutaneous dose is necessary, decreasing the risk of the patient to forget its use and, most important, it does not interfere in the patients quality of life.