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Dive into the research topics where Nikos Vlahos is active.

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Featured researches published by Nikos Vlahos.


Journal of Assisted Reproduction and Genetics | 2004

Impact of semen characteristics on the success of intrauterine insemination.

Yulian Zhao; Nikos Vlahos; David Wyncott; Carolina Petrella; Jairo E. Garcia; Howard A. Zacur; Edward E. Wallach

AbstractPatients: To evaluate the influence of sperm characteristics on the outcome of infertility treatment using intrauterine insemination (IUI). Methods: Retrospective study of 431 infertility couples who underwent 1007 IUI treatment cycles from June 1999 to October 2002. Sperm parameters before and after preparation for IUI were evaluated and correlated with pregnancy outcome. Results: Clinical pregnancy occurred in 12% of cycles and 28% of patients. Initial sperm motility and processed forward progression were independently associated with pregnancy after IUI. The mean number of cycles per patient was 4.3. Although pregnancy rate per cycle did not differ from cycle to cycle, the cumulative pregnancy rate approached plateau after five cycles. Conclusions: Sperm motility is an independent factor influencing IUI-related pregnancy. A forward progression score of 3 to 4 in a processed specimen is necessary for IUI success. The number of IUI attempts per patient should be individualized depending upon the needs of patients.


Fertility and Sterility | 2003

Prolactin gene expression in human ovarian follicular cells.

John Y. Phelps; Elizabeth M. Bugg; Michael J. Shamblott; Nikos Vlahos; Joe Whelan; Howard A. Zacur

OBJECTIVE To investigate prolactin gene expression in human ovarian follicular cells. DESIGN RNA was isolated from follicular cells obtained at the time of transvaginal oocyte retrieval from patients after controlled ovarian hyperstimulation. The RNA was subjected to reverse transcription and polymerase chain reaction (RT-PCR) using prolactin-specific primers. The RT-PCR products were analyzed by gel electrophoresis, followed by Southern blot analysis using prolactin-specific probes. SETTING Department of gynecology and obstetrics research laboratory. PATIENT(S) Women undergoing controlled ovarian hyperstimulation followed by transvaginal oocyte retrieval. INTERVENTION(S) Controlled ovarian hyperstimulation followed by transvaginal oocyte retrieval. Expression of prolactin mRNA by follicular cells. RESULT(S) The presence of prolactin-specific cDNA amplified by RT-PCR from RNA isolated from human follicular cells was confirmed by Southern blot analysis. CONCLUSION(S) Human ovarian follicular cells are an extrapituitary site of prolactin gene expression.


Journal of Assisted Reproduction and Genetics | 1999

Exogenous luteinizing hormone (LH) increases estradiol response patterns in poor responders with low serum LH concentrations.

John Y. Phelps; Lina Figueira-Armada; Adam S. Levine; Nikos Vlahos; Daniel Roshanfekr; Howard A. Zacur; Jairo E. Garcia

Purpose:Our purpose was to investigate whether the addition of exogenous leuteinizing hormone (LH) increases estradiol secretion in LH-depleted women undergoing controlled ovarian hyperstimulation (COH) with purified follicle stimulating hormone (FSH).Methods:We carried out case series and retrospective analysis of midfollicular serum LH concentrations and estradiol response patterns in COH cycles. All patients initially received gonadotropins containing purified FSH. Human menopausal gonadotropin containing LH was added to poor responders with low midfollicular LH concentrations.Results:The addition of exogenous LH to the COH regimen significantly increased estradiol secretion in poor responders with low midfollicular endogenous LH concentrations. This was confirmed statistically by an average change in the slope of the estradiol patterns from 27.54 to 85.49 after the addition of exogenous LH. Furthermore, patients with midfollicular serum LH concentrations <3.0 mIU/ml had significantly lower midfollicular and peak estradiol (E2) concentrations compared to patients with LH concentrations ≥3.0 mIU/ml (352.3 and 2094.3 vs 855.6 and 3757.1 pg/ml, respectively).Conclusions:The addition of exogenous LH increases E2response patterns in poor responders with low midfollicular serum LH concentrations. Low midfollicular serum LH concentrations are associated with significantly lower midfollicular and peak E2concentrations.


American Journal of Obstetrics and Gynecology | 2000

Clinical significance of the qualification of atypical squamous cells of undetermined significance: An analysis on the basis of histologic diagnoses

Nikos Vlahos; Katherine G. Dragisica; Edward E. Wallach; Frances H. Burroughsb; Susan Fluckb; Dorothy L. Rosenthal

OBJECTIVE This study was undertaken to evaluate the significance of further qualification of atypical squamous cells of undetermined significance in routine Papanicolaou smears. STUDY DESIGN A retrospective medical records review was conducted on 316 women whose Papanicolaou smears yielded diagnoses of either atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion or atypical squamous cells of undetermined significance suggestive of a reactive process. RESULTS The overall incidence of a squamous intraepithelial lesion (cervical intraepithelial neoplasia grades I, II, and III) was higher in the group with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion than in the group with results suggestive of a reactive process (41.1% vs 22.3%; P =.0344). Women with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion were 9.7 times more likely to have high-grade squamous intraepithelial lesion (cervical intraepithelial neoplasia III) develop than were women with atypical squamous cells of undetermined significance suggestive of a reactive process (95% confidence interval, 1.26-74.64). The incidence of high-grade squamous intraepithelial lesion was higher among women </=35 years old than among women >35 years old (17.8% vs 6.3%; P =.0378). CONCLUSION Women with a diagnosis of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion are more likely to have intraepithelial lesions develop than are those with atypical squamous cells of undetermined significance suggestive of a reactive process. Aggressive evaluation of cases of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion with colposcopy and cervical biopsies may be appropriate. Age should be considered as an independent factor in the plan of management.


Fertility and Sterility | 2003

An unusual complication of tubal anastomosis

Marcus W Jurema; Nikos Vlahos

OBJECTIVE To report an unusual complication associated with the use of a long-term intrafallopian stent during microsurgical tubal anastomosis. DESIGN Case report. SETTING Tertiary academic center. PATIENT(S) A 36-year-old woman in whom an intrafallopian stent used during a sterilization reversal procedure could not be transcervically retrieved in the office. INTERVENTION(S) Hysteroscopic evaluation for removal of intrafallopian stent, followed by operative laparoscopy for postoperative abdominal pain. MAIN OUTCOME MEASURE(S) Patient symptoms, potential for morbidity, and review of the literature. RESULT(S) Hysteroscopic view of the uterine cavity failed to identify the intrafallopian stent. Laporoscopic evaluation of postoperative abdominal pain revealed significant formation of pelvic and abdominal adhesions. The 2-0 nylon suture used as an intrafallopian stent was seen sitting freely on top of the liver serosa. Adhesiolysis and successful retrieval of the stent resolved the patients symptoms. CONCLUSION(S) To our knowledge, this is the first report describing complete dislodgment and cephalad migration of an intrafallopian stent. Patient morbidity and health care costs may increase when long-term stents are used for sterilization reversal.


International Journal of Gynecology & Obstetrics | 2008

Bizarre leiomyoma of the posterior vaginal fornix.

Nikos Vlahos; Konstantinos P. Economopoulos; Eva Skarpidi; Dimitrios Moraitis

Bizarre leiomyoma is a rare form of leiomyoma with benign behavior, despite microscopic features of malignancy. We report a case of a 33-year-old woman with a bizarre leiomyoma originating in the posterior vaginal fornix. The womans only reported symptom was dysmenorrhea and her past medical and surgical histories were unremarkable. Physical examination was also unremarkable, except for a sense of fullness in the posterior vaginal fornix. Magnetic resonance imaging of the pelvis confirmed the presence of a soft tissue mass (7.5×6.5×3 cm) filling the posterior cul-de-sac (Fig. 1). The mass was completely resected by an exploratory laparotomy under general anesthesia without entering the vagina and without compromising any of the adjacent organs. Evaluation of the abdominal cavity did not reveal any other pathology. The tumor had a solid, soft, multinodular, yellow-tan, semitranslucent cut surface giving the impression of a lipomatous neoplasm. Histologic evaluation of the mass revealed a well circumscribed neoplasm with a multinodular growth pattern composed of epithelioid cells. Most of the cells showed prominent pleomorphism with large, hyperchromatic, irregular, often multiple nuclei and eosinophilic intranuclear cytoplasmic inclusions. There was no mitotic activity or necrosis. Immunohistochemical stains revealed the neoplastic cells to be variably positive for desmin, smooth muscle actin, and muscle-specific actin (HHF-35) expression. These stains also highlighted smooth muscle bundles at the periphery of the lesion. The neoplastic cells were negative for CD34, pan-keratin, cytokeratin Cam5.2, epithelial membrane antigen (EMA), S-100 protein, HMB-45, Melan A, and CD117. Less than 2% of the neoplastic cells were positive for Ki-67 expression. The tumor was diagnosed as an epithelioid neoplasm with features consistent with bizarre leiomyoma. One year after the operation a transvaginal ultrasound revealed no evidence of recurrence. The term “bizarre” was originally used by Martin et al. [1] in 1960 to describe gastric leiomyomas. Subsequently, the term “bizarre leiomyoma” was adopted by the World Health Organization [2] to describe “a leiomyoma containing giant cells with pleomorphic nuclei and little or no mitotic activity.” The terms “atypical,” “pleomorphic,” and “symplastic” were acknowledged as synonymous designations. According to the largest series published by Downes et al. [3], these tumors generally resemble ordinary leiomyomas. In these series, mitoses ranged from 0 to 2.8 mitotic figures


Fertility and Sterility | 2003

Clinical outcome of using ganirelix acetate versus a 4-day follicular phase leuprolide acetate protocol in unselected women undergoing in vitro fertilization

M.Natalia Posada; Nikos Vlahos; M.W Jurema; N.J Bracero; Edward E. Wallach; Jairo E. Garcia

OBJECTIVE To compare the clinical outcome of controlled ovarian hyperstimulation (COH) in unselected patients undergoing IVF using multidose ganirelix acetate versus 4 days of administration of leuprolide acetate. DESIGN Retrospective cohort study. SETTING A fertility and IVF center. PATIENT(S) Two hundred forty-seven women who underwent COH-IVF between April 1, 1999, and January 30, 2001. INTERVENTION(S) Pituitary suppression according to a 4-day follicular phase leuprolide acetate protocol (236 women) or a multidose ganirelix acetate regimen (133 women). MAIN OUTCOME MEASURE(S) Amount of gonadotropin used, days of stimulation, cancellation rate, number of oocytes retrieved, implantation rate, and clinical pregnancy rate. RESULT(S) Compared with leuprolide acetate recipients, ganirelix recipients required significantly less gonadotropin and the mean day of hCG administration was 4 days earlier. Among women younger than 35 years of age, the implantation rate (15% vs. 6%) and the clinical pregnancy rate per initiated and transferred cycle (27% vs. 12% and 32% vs. 15%, respectively) were significantly higher in the ganirelix group than the leuprolide acetate group. CONCLUSION(S) Compared with a 4-day leuprolide acetate protocol, COH-IVF using a multidose ganirelix acetate protocol reduces treatment duration and amount of gonadotropin used. In younger women, the latter protocol is associated with significantly better pregnancy and implantation rates.


Postgraduate Obstetrics and Gynecology | 1998

Chronic Pelvic Pain

Nikos Vlahos; John Y. Phelps; Edward E. Wallach

After completing this lesson, the participant will be familiar with the epidemiology, pathophysiology, and etiology of pelvic pain, and be able to develop a s.ystematic diagnostic approach and strategic plan for the management of patients with chronic pelvic pain.


International Journal of Gynecology & Obstetrics | 2005

Non-puerperal uterine rupture after use of misoprostol and a Foley catheter for management of uterine bleeding

Nikos Vlahos; B.J. Bankowski; Evangelos Makrakis

Data supporting the use of mechanical tamponade and prostaglandins to control bleeding in the nonpuerperal uterus are scant [1—3]. We present a complication resulting from such a management of post-hysteroscopy vaginal bleeding, in order to highlight the associated risks. A 38-year-old woman, gravida 2 para 1010, presented for fertility counseling after an unfortunate obstetric outcome (preterm, premature rupture of membranes at 31 weeks of gestation, Cesarean Section at 32 weeks of gestation, neonatal death due to severe neuromuscular dysfunction of unknown etiology).


Postgraduate Obstetrics and Gynecology | 2005

Emerging Issues In Endometriosis

Nikos Vlahos; Kimberly B. Fortner

Endometriosis remains one of the more significant gynecologic pathologies because of its effect on quality of life, and reproductive capacity, and the difficulty encountered in its effective management. Treating endometriosis represents a significant expenditure of health care dollars. It is estimated that the cost of inpatient endometriosis treatment in the United States was

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Jairo E. Garcia

Johns Hopkins University School of Medicine

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John Y. Phelps

University of Texas Medical Branch

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M.W Jurema

Johns Hopkins University School of Medicine

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N.J Bracero

Johns Hopkins University School of Medicine

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Yulian Zhao

Johns Hopkins University School of Medicine

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Jeremy A. King

Johns Hopkins University

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Y. Zhao

Johns Hopkins University

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M.N Posada

Johns Hopkins University School of Medicine

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