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Featured researches published by P.A. Hassun.


Fertility and Sterility | 2010

Effects of semen storage and separation techniques on sperm DNA fragmentation

Robert Jackson; C.L. Bormann; P.A. Hassun; A.M. Rocha; E.L.A. Motta; Paulo Serafini; Gary D. Smith

OBJECTIVE To determine the effect of semen storage and separation techniques on sperm DNA fragmentation. DESIGN Controlled clinical study. SETTING An assisted reproductive technology laboratory. PATIENT(S) Thirty normoozospermic semen samples obtained from patients undergoing infertility evaluation. INTERVENTION(S) One aliquot from each sample was immediately prepared (control) for the sperm chromatin dispersion assay (SCD). Aliquots used to assess storage techniques were treated in the following ways: snap frozen by liquid nitrogen immersion, slow frozen with Tris-yolk buffer and glycerol, kept on ice for 24 hours or maintained at room temperature for 4 and 24 hours. Aliquots used to assess separation techniques were processed by the following methods: washed and centrifuged in media, swim-up from washed sperm pellet, density gradient separation, density gradient followed by swim-up. DNA integrity was then measured by SCD. MAIN OUTCOME MEASURE(S) DNA fragmentation as measured by SCD. RESULT(S) There was no significant difference in fragmentation among the snap frozen, slow frozen, and wet-ice groups. Compared to other storage methods short-term storage at room temperature did not impact DNA fragmentation yet 24 hours storage significantly increased fragmentation. Swim-up, density gradient and density gradient/swim-up had significantly reduced DNA fragmentation levels compared with washed semen. Postincubation, density gradient/swim-up showed the lowest fragmentation levels. CONCLUSION(S) The effect of sperm processing methods on DNA fragmentation should be considered when selecting storage or separation techniques for clinical use.


Reproductive Sciences | 2010

Review: Follicular Waves in the Human Ovary: A New Physiological Paradigm for Novel Ovarian Stimulation Protocols

P.H.M. Bianchi; Paulo Serafini; A.M. Rocha; P.A. Hassun; E.L.A. Motta; P. S. Baruselli; E.C. Baracat

Ovulation induction (OI) is a cornerstone of human assisted reproduction treatments (ART). Current OI protocols are based on the human follicular dynamics model known as propitious moment theory (PMT), by which follicles continuously grow from the primordial pool without any pattern, and follicular fate depend on the occurrence of a gonadotropin surge. Recently, a new paradigm of human follicular dynamics called follicular waves was revealed using sequential ultrasound examination of 1 interovulatory interval. Instead of random growth, follicles develop in coordinated groups or waves, occurring 2 to 3 times during an interovulatory interval. Follicular waves are common in several other mono-ovulatory species, like equines and bovines. In fact, this model was applied to the development of several OI protocols in veterinary medicine, especially in cows. It has been shown that synchronization of OI with the emergence of a follicular wave increases substantially success rates in animals, even with single embryo transfer. Veterinarians have already developed mechanisms to control wave emergence through mechanical or chemical ablation of the dominant follicle or corpus luteum. Considering the follicular dynamics similarities between humans and bovines regarding the follicular wave phenomenon, we hypothesize that synchronization of follicular wave emergence with ovarian stimulation produces more competent oocytes and embryos and will enhance ART efficiency in humans. At the end of this article, we propose 2 theoretical approaches to induce the emergence of a follicular wave in women: (1) a mechanical strategy by aspiration of the dominant follicle and (2) a pharmacological strategy by administering estradiol and progesterone.


Gynecological Endocrinology | 2009

Protein profile of the luteal phase endometrium by tissue microarray assessment

Paulo Serafini; A.M. Rocha; Cyntia T. Osório; Gary D. Smith; P.A. Hassun; Ismael Dale Cotrim Guerreiro da Silva; E.L.A. Motta; Edmund Chada Baracat

To investigate the luteal phase endometrial expression of leukemia inhibitor factor (LIF), insulin-like growth factor 1 (IGF-1), progesterone receptor (PR), claudin 4 (CLDN4), vascular-endothelial growth factor receptor 3 (VEGFR-3), bone morphogenetic protein 4 (BMP-4) and citokeratin 7 (CK-7), we obtained luteal phase endometrial samples from 52 women. Samples were dated and integrated using a tissue microarray (TMA). Samples were immunostained for LIF, IGF-1, PR, CLDN4, VEGFR-3, BMP-4 and CK-7. Frequencies of positive expressions at the early, mid and late luteal phases were compared by two proportions test. Concomitant expression of these proteins was assessed with Chi-square or Fischers test. The frequency of LIF was positively correlated to the frequency of IGF-1 (r = 0.99; p < 0.05) and PR (r = 0.99; p < 0.05), and the correlation between IGF-1 and PR tended to be significant (r = 0.98; p < 0.1). The expression of PR was associated with the absence of CLDN4 (p < 0.001). Thus, expression of LIF, IGF-1 and PR are correlated during the luteal phase, and immunohistochemistry for these proteins might be used to assist in the assessment of endometrial maturation. In addition, the expression of CLDN4 and PR was not concomitant, warranting further investigation on the relationship of their endometrial expression.


Journal of Assisted Reproduction and Genetics | 2009

Human choriogonadotropin prior to controlled ovarian stimulation and in vitro fertilization improves implantation, and pregnancy rates

E.L.A. Motta; Gary D. Smith; Paulo Serafini; M. Coslovsky; P.A. Hassun; A.M. Rocha; Isaac Yadid

PurposeOur purpose was to retrospectively compare controlled ovarian stimulation(COH) in IVF cycles with administration of hCG on the day of menses (D1-hCG) with women not receiving hCG at day 1 of menses (Control).MethodsData on maternal age, endocrine profile, amount of rFSH required, embryo characteristics, implantation and pregnancy rates were recorded for comparison between D1-hCG (n = 36) and Control (n = 64).ResultsDose of rFSH required to accomplish COH was significantly lower in D1-hCG. Following ICSI, more top-quality embryos were available for transfer per patient in the D1-hCG and biochemical pregnancy rates per transfer were significantly higher in the D1-hCG. Significantly higher implantation and on-going pregnancy rates per embryo transfer were observed in D1-hCG (64%) compared to Control (41%).ConclusionsAdministration of D1-hCG prior to COH reduces rFSH use and enhances oocyte developmental competence to obtain top quality embryos, and improves implantation and on-going pregnancy rates. At present it is not clear if the benefit is related to producing an embryo that more likely to implant or a more receptive uterus, or merely fortuitous and related to the relatively small power of the study.


Fertility and Sterility | 2007

Prospective randomized comparison of human oocyte freezing and vitrification: an update

J. Fioravanti; J.R. Alegretti; P.A. Hassun; E.L.A. Motta; Paulo Serafini; Gary D. Smith


Fertility and Sterility | 2006

O-224: Prospective randomized controlled study of human oocyte cryopreservation by slow-rate freezing and/or vitrification

Gary D. Smith; J. Fioravanti; P.A. Hassun; J.R. Alegretti; E.L.A. Motta; Paulo Serafini


Fertility and Sterility | 2008

The effect of sperm separation on sperm chromatin decondensation and motility at 0 and 24 hours of culture

C.L. Bormann; A.M. Rocha; P.A. Hassun; E.L.A. Motta; P. Serafini; Gary D. Smith


Fertility and Sterility | 2007

Individualized assessment of oocyte cumulus cell health and oocyte quality, fertilization, embryo development and implantation

P.A. Hassun; M. Ribeiro; A.M. Rocha; Gary D. Smith; E.L.A. Motta; Paulo Serafini


Fertility and Sterility | 2007

High throughput evaluation of cumulus cell viability and apoptosis using fluorescent activated cell sorting influence of mode of GnRH down-regulation

P.A. Hassun; M. Ribeiro; A.M. Rocha; Gary D. Smith; E.L.A. Motta; P. Serafini


Fertility and Sterility | 2011

Preimplantation genetic screening using array CGH improves clinical pregnancy rates in AMA patients

J.F. Cuzzi; J.R. Alegretti; A. Harutunian; M. Hughes; P.A. Hassun

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E.L.A. Motta

Federal University of São Paulo

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Paulo Serafini

University of São Paulo

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A.M. Rocha

University of Michigan

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J.R. Alegretti

Federal University of São Paulo

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Agnaldo Pereira Cedenho

Federal University of São Paulo

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Miguel Srougi

University of São Paulo

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Valdemar Ortiz

Federal University of São Paulo

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