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Dive into the research topics where David E Tourgeman is active.

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Featured researches published by David E Tourgeman.


Gynecologic Oncology | 2003

The proto-oncogene c-kit is expressed in leiomyosarcomas of the uterus.

Lina Wang; Juan C. Felix; Joyce L Lee; Peik Y Tan; David E Tourgeman; Anne T O’Meara; Charles A. Amezcua

OBJECTIVE The proto-oncogene c-kit encodes for a 145-kDa transmembrane tyrosine kinase receptor. Interaction with its ligand, stem cell factor, is essential in the development of hematopoietic stem cells, mast cells, gametocytes, melanocytes, and interstitial cells of Cajal. C-kit expression has been identified in a number of different neoplasms that includes mastocytosis/mast cell leukemia, acute myeloblastic leukemia, seminoma/dysgerminoma, and gastrointestinal stromal tumors. This study examines c-kit expression in uterine endometrial stromal sarcomas, leiomyomas, and leiomyosarcomas using immunohistochemistry. METHODS Archival tissue from 38 patients with the uterine mesenchymal tumors (16 leiomyosarcomas, 8 leiomyomas, 11 low-grade endometrial stromal sarcomas, and 3 high-grade endometrial stromal sarcomas) was stained with polyclonal antibody for c-kit. Modified avidin biotin (ABC) immunoperoxidase method was employed for antibody detection. Individual tumors were considered positive if more than 10% of the cells comprising the neoplasm displayed immunoreactive staining. Staining intensity was graded 1+ to 3+ and distribution graded as focal (10-30% of the cells), intermediate (30-60% of the cells), or diffuse (>60% of the cells). RESULTS C-kit was positive in 12 (75%) of the 16 leiomyosarcomas. The staining was 3+ and diffuse in the majority of the positive tumors. C-kit expression was not detected in any of the 8 leiomyomas. Two of the 3 high-grade endometrial stromal sarcomas displayed c-kit positivity. Staining was diffuse and 3+ in both of these tumors. Expression of c-kit was observed in only 3 of the 11 low-grade endometrial stromal sarcomas. CONCLUSIONS C-kit is expressed in uterine leiomyosarcomas and endometrial stromal sarcomas. Adjunctive diagnostic studies using c-kit may be useful in distinguishing leiomyosarcomas from benign leiomyomas in uterine tumors that offer uncharacteristic features. Furthermore, studies should investigate the prospect of treating these malignant tumors with tyrosine kinase inhibitors.


American Journal of Obstetrics and Gynecology | 1999

Serum and tissue hormone levels of vaginally and orally administered estradiol

David E Tourgeman; Elisabet Gentzchein; Frank Z. Stanczyk; Richard J. Paulson

OBJECTIVE Our purpose was to determine serum and endometrial estradiol levels when micronized estradiol is administered vaginally and orally. STUDY DESIGN Five subjects were given oral estradiol (2 mg twice daily), during an artificial luteal phase, and another group of 5 subjects were given the same dose of estradiol by the vaginal route. Endometrial biopsies and blood samples were obtained on day 21 of the cycle, 2 hours after the last dose was administered. Tissue and blood samples were assayed for estradiol. RESULTS Serum estradiol levels were significantly higher with vaginally administered estradiol than with orally administered estradiol (2344 +/- 398 vs 279 +/- 76 pg/mL, P <.005). Endometrial estradiol concentrations were also significantly higher with vaginally administered estradiol than with the oral preparation (918 +/- 412 vs 13 +/- 2 pg/mg protein, P <.05). CONCLUSIONS Vaginal administration of estradiol is more effective in increasing serum and endometrial levels of estradiol than the oral route and may represent the optimal route of administration for recipients of egg donation. If the vaginal route of estradiol administration is considered for menopausal replacement therapy, much lower doses of the standard oral quantities should be used. Furthermore, if the uterus is present, a progestin must be used to compensate for the high tissue levels of estradiol.


Fertility and Sterility | 2001

Endocrine and clinical effects of micronized estradiol administered vaginally or orally

David E Tourgeman; Cristin C. Slater; Frank Z. Stanczyk; Richard J. Paulson

OBJECTIVE To determine the impact of the vaginal route of micronized estradiol (E(2)) administration upon hepatic globulin and lipid production and upon the outcome of oocyte donation cycles in which the recipients received E(2) via this route. DESIGN Series report. SETTING University-based assisted reproduction techniques (ART) program. PATIENT(S) Recipients of donor oocytes. INTERVENTION(S) Administration of micronized E(2) via the oral or vaginal route, oocyte donation, and embryo transfer. MAIN OUTCOME MEASURE(S) Measurements of the serum levels of free E(2), sex hormone-binding globulin (SHBG), total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), as well as endometrial thickness and pregnancy outcome. RESULT(S) Serum SHBG and lipoprotein levels were unaltered by the vaginal as compared with the oral route of E(2) administration. Serum free E(2) levels were significantly higher after vaginal administration. Ten patients who had previously failed to achieve adequate endometrial thickness with an oral regimen were found to have adequate endometrial thickness after vaginal E(2) administration and seven of them achieved an ongoing pregnancy after embryo transfer. CONCLUSION(S) Vaginal administration of micronized E(2) results in significantly higher free serum E(2) levels when compared to levels achieved after oral E(2) administration. Hepatic globulin and lipoprotein production is similar despite 10-fold higher serum E(2) levels after the vaginal administration. The greater efficiency of E(2) delivery to the endometrium after vaginal administration makes this route a good option for patients who fail to achieve adequate endometrial thickness with oral E(2) administration.


Fertility and Sterility | 2002

Human chorionic gonadotropin suppresses ovarian epithelial neoplastic cell proliferation in vitro

David E Tourgeman; Jean J. Lu; Charles A. Amezcua; Juan C. Felix; Richard J. Paulson

OBJECTIVE To quantify the in vitro effects of gonadotropins on benign, borderline, and malignant ovarian cell lines. DESIGN In vitro cell culture. SETTING Research laboratory. PATIENT(S) None. INTERVENTION(S) Three hormonally sensitive ovarian neoplastic cell lines were exposed to control medium, FSH (40 mIU/mL), hCG (200 mIU/mL), and a combination of FSH and hCG. MAIN OUTCOME MEASURE(S) Cellular proliferation measured by a colorimetric (MTT) assay. RESULT(S) Growth of the cell lines was similar when exposed to control or FSH. In the presence of hCG alone, the cell lines demonstrated decreased proliferation when compared to control or FSH alone. When hCG was given in combination with FSH, there was decreased proliferation of the cell lines compared to control or FSH alone. CONCLUSION(S) Growth of benign, borderline, and malignant ovarian epithelial cell lines is inhibited by hCG at levels, which are commonly achieved with hCG administration during ovulation induction or as a result of trophoblastic production in early pregnancy.


Journal of Assisted Reproduction and Genetics | 2003

Treatment-Associated Serum FSH Levels in Very Poor Responders to Ovarian Stimulation

Peyman Saadat; Cristin C. Slater; John K. Jain; David E Tourgeman; Frank Z. Stanczyk; Richard J. Paulson

AbstractPurpose: To compare treatment-associated follicle-stimulating hormone (FSH) response in patients undergoing controlled ovarian hyperstimulation with either microdose flare (MDF) leuprolide acetate or clomiphene citrate and human menopausal gonadotropin (CC/hMG). Methods: Thirteen patients who were deemed poor responders underwent stimulation with one of two poor responder stimulation protocols (MDF group: n = 8; CC/hMG group: n = 5). Serum FSH, estrone (E1), estrone sulfate (E1S), and estradiol (E2) levels were measured at baseline, day 5 of medication, and on day of hCG administration. Ovarian and uterine responses were evaluated by ultrasound. Results: Treatment-associated FSH levels were consistently higher in the group that took CC/hMG. However, serum E1, E1S, and E2 values were similar in both groups as were the number of oocytes retrieved and the endometrial echo complex. There were no differences between the two groups with regards to the quality of the oocytes obtained, fertilization rate, or the quality of the embryos. Conclusion: Clomiphene citrate, when administered in conjunction with exogenous hMG, is a more potent stimulator of FSH production than MDF leuprolide acetate among poor responders to ovarian stimulation. However, the number of oocytes is not increased.


Fertility and Sterility | 2001

Pregnancy rates following fimbriectomy reversal via neosalpingostomy: a 10-year retrospective analysis

David E Tourgeman; Manjita Bhaumik; Gregory C. Cooke; Sam Najmabadi; Richard J. Paulson; John K. Jain

OBJECTIVE To establish parameters associated with successful fimbriectomy reversal and to estimate monthly fecundability and cumulative pregnancy rates through life-table analysis. DESIGN Series report. SETTING University-based infertility clinic. PATIENT(S) Forty-one women undergoing surgery for tubal sterilization reversal. INTERVENTION(S) Surgical fimbriectomy reversal. MAIN OUTCOME MEASURE(S) Time from sterilization to reversal, laparoscopy vs. laparotomy, uni- vs. bilateral fimbriectomy reversal, Bruhat vs. suture, tubal lengths, postsurgical hysterosalpingogram, ovulation induction, incidence of pregnancy and outcome, and life-table analysis to determine pregnancy rate. RESULT(S) The mean time from sterilization to reversal was 11.5 years. Of the 41 women who underwent fimbriectomy reversal, 6 (14.6%) conceived. Sixteen reversals were performed by laparotomy resulting in 4 (25%) pregnancies, whereas 25 were performed laparoscopically resulting in 2 (8%) pregnancies. Eight had unilateral salpingostomies and 33 bilateral, of which 1 of 8 (12.5%) and 5 of 33 (15.2%) conceived, respectively. Using the Bruhat technique, 1 of 11 (9%) conceived vs. 5 of 30 (16.7%) that underwent reversal using sutures. The mean postoperative tubal length for the 6 women who conceived was 8 cm vs. 6.7 cm in the 35 women who did not conceive. Postoperatively, 26 women received ovulation induction and 1 (3.8%) conceived whereas 5 (33.3%) conceptions occurred in 15 women who did not require ovulation induction. Using life-table analysis with 619 postsurgical cycles, the monthly fecundability was.0097. The cumulative conception rate after 5 years was 31.2%. CONCLUSION(S) Neosalpingostomy for the reversal of fimbriectomy sterilization represents a viable option for fertility restoration. The best candidates for this procedure are spontaneously ovulatory and have a tubal length of more than 7 cm.


Journal of Assisted Reproduction and Genetics | 2012

The sensitivity and specificity of hyperglycosylated hCG (hhCG) levels to reliably diagnose clinical IVF pregnancies at 6 days following embryo transfer

Charles M. Strom; Ruben Bonilla-Guererro; Ke Zhang; K.J. Doody; David E Tourgeman; Ruben Alvero; Marcelle I. Cedars; Beryl Crossley; Raj Pandian; Rajesh Sharma; Julie Neidich; Denise Salazar

ObjectiveTo determine the sensitivity and specificity of hyperglycosylated hCG (hhCG) measurements for the diagnosis of clinical pregnancies in the IVF setting and how soon post embryo transfer (ET) a pregnancy can be detected using an ultrasensitive (hhCG) assay. To determine if a single, early hhCG measurement can discriminate between biochemical and clinical pregnancies.DesignA 4 center prospective blinded clinical trial was performed with patients undergoing IVF-ET. Patients had blood drawn and submitted for hhCG analysis on the day of ET and at days 4, 6, 8, and 12 thereafter. First morning urines were collected and submitted for hhCG analysis on days 0, 4, 6, 8, 10 and 12.SettingFertility CentersOutcome MeasuresClinical pregnancies were defined as an ultrasound study demonstrating a gestational sac and/or heart beat at appropriate gestational ages.ResultsFifty-six of 58 enrolled patients completed the study. There were 25 clinical and 6 biochemical pregnancies. For blastocyst transfers, a single serum or urine hhCG measurement identified pregnancies (both biochemical and clinical) at 6 days post ET with 100% sensitivity and specificity. There were 6 biochemical pregnancies, all following blastocyst transfers. All of these pregnancies were identified by lower values.


Journal of Assisted Reproduction and Genetics | 2001

The prognostic significance of day 3 embryo cleavage stage on subsequent blastocyst development in a sequential culture system.

John K. Jain; Cristin C. Slater; David E Tourgeman; Mary M. Francis; Richard J. Paulson

AbstractPurpose: To determine prognostic significance of blastomere number on Day 3 of culture upon subsequent blastocyst (BL) development. Methods: A retrospective analysis was conducted in 37 IVF subjects undergoing standard protocols and BL transfer after sequential embryo culture in P1 and BL media. Results: Of Day 3 embryos containing 7 or more blastomeres, 68.9% (186/270) developed into BL compared to embryos containing 4–6 blastomeres, 38.1% (56/147), P < 0.0001. The majority of BL, 68.9% (168/244), were observed on Day 5. Extended Day 6 culture represented 31.1% (76/244) of all BLs. Conclusions: The observation of 7 or more blastomeres on Day 3 yielded a significantly greater likelihood of BL development. Embryos containing 4–6 blastomeres are still relatively likely to progress to a BL. Extended culture to Day 6 still yields a significant proportion of BL. Cell cleavage stage on Day 3 appears to be a useful prognostic indicator of subsequent BL development.


Journal of the National Cancer Institute | 1994

Microsatellite Instability in Sporadic Endometrial Carcinoma

Bridgette D. Duggan; Juan C. Felix; Laila l. Muderspach; David E Tourgeman; Jian Zheng; Darryl Shibata


JAMA | 2002

Pregnancy in the Sixth Decade of Life Obstetric Outcomes in Women of Advanced Reproductive Age

Richard J. Paulson; Peyman Saadat; Eliran Mor; David E Tourgeman; Cristin C. Slater; Mary M. Francis; John K. Jain

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Richard J. Paulson

University of Southern California

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Peyman Saadat

University of Southern California

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Frank Z. Stanczyk

University of Southern California

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Cristin C. Slater

University of Southern California

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John K. Jain

University of Southern California

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Eliran Mor

University of Southern California

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Juan C. Felix

University of Southern California

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Mary M. Francis

University of Southern California

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Aykut Bayrak

University of Southern California

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Charles A. Amezcua

University of Southern California

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