Gregory M. Christman
University of Michigan
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Gregory M. Christman.
The New England Journal of Medicine | 2014
Richard S. Legro; Robert G. Brzyski; Michael P. Diamond; Christos Coutifaris; William D. Schlaff; Peter R. Casson; Gregory M. Christman; Hao Huang; Qingshang Yan; Ruben Alvero; Daniel J. Haisenleder; Kurt T. Barnhart; G. Wright Bates; Rebecca S. Usadi; Scott Lucidi; Valerie L. Baker; J. C. Trussell; Stephen A. Krawetz; Peter J. Snyder; Dana A. Ohl; Nanette Santoro; Esther Eisenberg; Heping Zhang
BACKGROUND Clomiphene is the current first-line infertility treatment in women with the polycystic ovary syndrome, but aromatase inhibitors, including letrozole, might result in better pregnancy outcomes. METHODS In this double-blind, multicenter trial, we randomly assigned 750 women, in a 1:1 ratio, to receive letrozole or clomiphene for up to five treatment cycles, with visits to determine ovulation and pregnancy, followed by tracking of pregnancies. The polycystic ovary syndrome was defined according to modified Rotterdam criteria (anovulation with either hyperandrogenism or polycystic ovaries). Participants were 18 to 40 years of age, had at least one patent fallopian tube and a normal uterine cavity, and had a male partner with a sperm concentration of at least 14 million per milliliter; the women and their partners agreed to have regular intercourse with the intent of conception during the study. The primary outcome was live birth during the treatment period. RESULTS Women who received letrozole had more cumulative live births than those who received clomiphene (103 of 374 [27.5%] vs. 72 of 376 [19.1%], P=0.007; rate ratio for live birth, 1.44; 95% confidence interval, 1.10 to 1.87) without significant differences in overall congenital anomalies, though there were four major congenital anomalies in the letrozole group versus one in the clomiphene group (P=0.65). The cumulative ovulation rate was higher with letrozole than with clomiphene (834 of 1352 treatment cycles [61.7%] vs. 688 of 1425 treatment cycles [48.3%], P<0.001). There were no significant between-group differences in pregnancy loss (49 of 154 pregnancies in the letrozole group [31.8%] and 30 of 103 pregnancies in the clomiphene group [29.1%]) or twin pregnancy (3.4% and 7.4%, respectively). Clomiphene was associated with a higher incidence of hot flushes, and letrozole was associated with higher incidences of fatigue and dizziness. Rates of other adverse events were similar in the two treatment groups. CONCLUSIONS As compared with clomiphene, letrozole was associated with higher live-birth and ovulation rates among infertile women with the polycystic ovary syndrome. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00719186.).
The Journal of Clinical Endocrinology and Metabolism | 2010
Richard S. Legro; William D. Schlaff; Michael P. Diamond; Christos Coutifaris; Peter R. Casson; Robert G. Brzyski; Gregory M. Christman; J. C. Trussell; Stephen A. Krawetz; Peter J. Snyder; Dana A. Ohl; Sandra Ann Carson; Michael P. Steinkampf; Bruce R. Carr; Peter G. McGovern; Gabriella G. Gosman; John E. Nestler; Evan R. Myers; Nanette Santoro; Esther Eisenberg; M. Zhang; Heping Zhang
CONTEXT There is no standardized assay of testosterone in women. Liquid chromatography mass spectrometry (LC/MS) has been proposed as the preferable assay by an Endocrine Society Position Statement. OBJECTIVE The aim was to compare assay results from a direct RIA with two LC/MS. DESIGN AND SETTING We conducted a blinded laboratory study including masked duplicate samples at three laboratories--two academic (University of Virginia, RIA; and Mayo Clinic, LC/MS) and one commercial (Quest, LC/MS). PARTICIPANTS AND INTERVENTIONS Baseline testosterone levels from 596 women with PCOS who participated in a large, multicenter, randomized controlled infertility trial performed at academic health centers in the United States were run by varying assays, and results were compared. MAIN OUTCOME MEASURE We measured assay precision and correlation and baseline Ferriman-Gallwey hirsutism scores. RESULTS Median testosterone levels were highest with RIA. The correlations between the blinded samples that were run in duplicate were comparable. The correlation coefficient (CC) between LC/MS at Quest and Mayo was 0.83 [95% confidence interval (CI), 0.80-0.85], between RIA and LC/MS at Mayo was 0.79 (95% CI, 0.76-0.82), and between RIA and LC/MS at Quest was 0.67 (95% CI, 0.63-0.72). Interassay variation was highest at the lower levels of total testosterone (≤50 ng/dl). The CC for Quest LC/MS was significantly different from those derived from the other assays. We found similar correlations between total testosterone levels and hirsutism score with the RIA (CC=0.24), LC/MS at Mayo (CC=0.15), or Quest (CC=0.17). CONCLUSIONS A testosterone RIA is comparable to LC/MS assays. There is significant variability between LC/MS assays and poor precision with all assays at low testosterone levels.
Urology | 2002
David C. Miller; Brent K. Hollenbeck; Gary D. Smith; John F. Randolph; Gregory M. Christman; Yolanda R. Smith; Dan I. Lebovic; Dana A. Ohl
OBJECTIVES To determine the impact of processed total motile sperm (PTMS) count on pregnancy after partner intrauterine insemination (IUI). IUI is generally attempted before proceeding to more expensive and invasive assisted-reproductive techniques such as intracytoplasmic sperm injection. Several semen parameters have been shown to correlate with IUI outcome and may be useful when counseling couples. METHODS Four hundred thirty-eight couples with diverse causes of infertility underwent 1114 cycles of husband IUI during a 39-month period. The clinical and semen parameters were recorded for each couple and each insemination. The parameters were compared between those couples who achieved a pregnancy and those who did not. RESULTS The total number of pregnancies was 120, resulting in a pregnancy rate per cycle of 10.8% and a couple pregnancy rate of 27.4%. On multivariable logistic regression analysis, the PTMS count was independently associated with fertility after IUI (P = 0.0014). Moreover, the pregnancy rate was significantly lower for couples with less than 10 million PTMS (P <0.05). CONCLUSIONS The results of this study have demonstrated that the PTMS count independently predicts success with IUI. Cycles with less than 10 million total motile sperm are significantly less likely to result in a pregnancy. If cause-specific therapy has failed, alternatives to IUI should be considered for couples when the PTMS count is less than 10 million.
American Journal of Obstetrics and Gynecology | 2008
Rebecca Rogers; John M. Norian; M. Malik; Gregory M. Christman; Mones Abu-Asab; Faye Chen; Casey L. Korecki; James C. Iatridis; William H. Catherino; Rocky S. Tuan; Namisha Dhillon; Phyllis C. Leppert; James H. Segars
OBJECTIVE Uterine leiomyoma produce an extracellular matrix (ECM) that is abnormal in its volume, content, and structure. Alterations in ECM can modify mechanical stress on cells and lead to activation of Rho-dependent signaling and cell growth. Here we sought to determine whether the altered ECM that is produced by leiomyoma was accompanied by an altered state of mechanical homeostasis. STUDY DESIGN We measured the mechanical response of paired leiomyoma and myometrial samples and performed immunogold, confocal microscopy, and immunohistochemical analyses. RESULTS Leiomyoma were significantly stiffer than matched myometrium. The increased stiffness was accompanied by alteration of the ECM, cell shape, and cytoskeleton in leiomyoma, compared with myometrial samples from the same uterus. Levels of AKAP13, a protein that is known to activate Rho, were increased in leiomyoma compared to myometrium. AKAP13 was associated with cytoskeletal filaments of immortalized leiomyoma cells. CONCLUSION Leiomyoma cells are exposed to increased mechanical loading and show structural and biochemical features that are consistent with the activation of solid-state signaling.
Fertility and Sterility | 2011
Matthew A. Will; Jason E. Swain; Mikkel Fode; Jens Sønksen; Gregory M. Christman; Dana A. Ohl
OBJECTIVE To evaluate the current literature on the impact and potential mechanisms of varicocele repair on male fertility. DESIGN Pertinent articles were identified through computer PubMed search on varicocele repair and male factor infertility. References of selected articles were hand searched for additional citations. CONCLUSION(S) Varicocele repair has been shown to reverse a spectrum of effects contributing to men with impaired fertility. Clinical studies on the intervention have illustrated variable effects on postoperative sperm parameters and pregnancy rates (PR). Studies with conflicting results suffer from a significant number of confounding variables such as variable repair technique or lack of controls. Additional studies are warranted on the role of modern microsurgical varicocelectomy given the improvements in assisted reproductive technologies (ART).
Fertility and Sterility | 2001
Dana A. Ohl; Lynda J. Wolf; Alan C. Menge; Gregory M. Christman; William W. Hurd; Rudi Ansbacher; Yolanda R. Smith; John F. Randolph
OBJECTIVE To determine the efficacy of electroejaculation in combination with assisted reproductive technology (ART). DESIGN Case series. SETTING University fertility program. PATIENT(S) One hundred twenty-one consecutive couples seeking treatment of anejaculatory infertility. INTERVENTION(S) Electroejaculation with IUI, or gamete intrafallopian transfer or IVF. MAIN OUTCOME MEASURE(S) Pregnancy and pregnancy outcome. RESULT(S) Fifty-two couples became pregnant (43%), 39 by IUI alone (32.2%). Cycle fecundity for IUI was 8.7%. No difference in cycle fecundity was seen among ovarian stimulation protocols (clomiphene citrate, 7.6%, hMG, 13.2%, and natural cycle, 11.2%). Pregnancy was unlikely when the inseminated motile sperm count was <4 million. Female management protocol and etiology of anejaculation did not affect results. Patients undergoing IVF had higher cycle fecundity (37.2%) than did those undergoing IUI. The rates of spontaneous abortion and multiple gestations were 23% and 12%, respectively. CONCLUSION(S) Electroejaculation with stepwise application of ART is effective in treating anejaculatory infertility. Intrauterine insemination with the least expensive monitoring protocol should be used for most couples, because use of more expensive monitoring did not improve results. It is cost-effective to bypass IUI and proceed directly to IVF in men who require anesthesia for electroejaculation and in those with a total inseminated motile sperm count < 4 million.
The New England Journal of Medicine | 2015
Michael P. Diamond; Richard S. Legro; Christos Coutifaris; Ruben Alvero; Randal D. Robinson; Peter R. Casson; Gregory M. Christman; Joel Ager; Hao Huang; Karl R. Hansen; Valerie L. Baker; Rebecca S. Usadi; Aimee Seungdamrong; G.W. Bates; Rosen Rm; Daniel J. Haisenleder; Stephen A. Krawetz; Kurt T. Barnhart; J. C. Trussell; Dana A. Ohl; Yufeng Jin; Nanette Santoro; Esther Eisenberg; Heping Zhang
BACKGROUND The standard therapy for women with unexplained infertility is gonadotropin or clomiphene citrate. Ovarian stimulation with letrozole has been proposed to reduce multiple gestations while maintaining live birth rates. METHODS We enrolled couples with unexplained infertility in a multicenter, randomized trial. Ovulatory women 18 to 40 years of age with at least one patent fallopian tube were randomly assigned to ovarian stimulation (up to four cycles) with gonadotropin (301 women), clomiphene (300), or letrozole (299). The primary outcome was the rate of multiple gestations among women with clinical pregnancies. RESULTS After treatment with gonadotropin, clomiphene, or letrozole, clinical pregnancies occurred in 35.5%, 28.3%, and 22.4% of cycles, and live birth in 32.2%, 23.3%, and 18.7%, respectively; pregnancy rates with letrozole were significantly lower than the rates with standard therapy (gonadotropin or clomiphene) (P=0.003) or gonadotropin alone (P<0.001) but not with clomiphene alone (P=0.10). Among ongoing pregnancies with fetal heart activity, the multiple gestation rate with letrozole (9 of 67 pregnancies, 13%) did not differ significantly from the rate with gonadotropin or clomiphene (42 of 192, 22%; P=0.15) or clomiphene alone (8 of 85, 9%; P=0.44) but was lower than the rate with gonadotropin alone (34 of 107, 32%; P=0.006). All multiple gestations in the clomiphene and letrozole groups were twins, whereas gonadotropin treatment resulted in 24 twin and 10 triplet gestations. There were no significant differences among groups in the frequencies of congenital anomalies or major fetal and neonatal complications. CONCLUSIONS In women with unexplained infertility, ovarian stimulation with letrozole resulted in a significantly lower frequency of multiple gestation but also a lower frequency of live birth, as compared with gonadotropin but not as compared with clomiphene. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01044862.).
American Journal of Physiology-gastrointestinal and Liver Physiology | 1997
Ellen M. Zimmermann; Lina Li; Yong Tai Hou; M. Cannon; Gregory M. Christman; Khalil N. Bitar
Insulin-like growth factor (IGF) binding protein 5 (IGFBP-5) mRNA was studied in intestines of rats with peptidoglycan-polysaccharide enterocolitis by Northern analysis and in situ hybridization. IGFBP-5 mRNA was increased 2.4 ± 0.5-fold in inflamed rat colon compared with controls and was highly expressed in smooth muscle. Cultured rat intestinal smooth muscle cells were used to study the regulation of IGFBP-5 and type I collagen synthesis. IGF-I (100 ng/ml) increased IGFBP-5 mRNA (1.9 ± 0.1-fold) and collagen type α1(I) mRNA (1.6 ± 0.2-fold) in cultured smooth muscle cells. IGF-I induced a dose- and time-dependent increase in IGFBP-5 in conditioned medium by Western ligand blot and by immunoblot. IGF-I did not affect the IGFBP-5 mRNA decay rate after transcriptional blockade. Cycloheximide abolished IGFBP-5 mRNA. In conclusion, IGFBP-5 mRNA is expressed by intestinal smooth muscle and is increased during chronic inflammation. IGF-I increases IGFBP-5 and collagen mRNAs in intestinal smooth muscle cells.
Fertility and Sterility | 1999
Alan C. Menge; Gregory M. Christman; Dana A Ohl; Rajesh K. Naz
OBJECTIVE To determine if fertilization antigen (FA)-1 will remove autoantibodies from the surface of sperm cells of immunoinfertile men by immune adsorption and permit an increased acrosome reaction (AR). DESIGN Prospective analytic study. SETTING University medical center. PATIENT(S) Men from 18 infertile couples with autoantibodies present on their spermatozoa. INTERVENTION(S) Sperm samples after processing were examined for antibody binding and AR before and after adsorption with control medium or FA-1. MAIN OUTCOME MEASURE(S) Sperm-bound antibody was assessed by the immunobead assay (immunoglobulin [Ig] A and IgG) and the AR by induction with ionophore A23187. RESULT(S) Adsorption with FA-1 compared with control medium increased immunobead-free swimming sperm an average of 50% and 76% for IgA and IgG antisperm antibodies, respectively, with 78% and 100% of the 18 semen specimens increasing significantly. The AR rate increased an average of 10.3% compared with control medium and showed improvement in 78% of the sperm samples after FA-1 adsorption. CONCLUSION(S) The FA-1 sperm antigen appears to significantly free sperm cells coated with autoantibodies in the semen of most infertile men examined. Reducing sperm-bound antibodies that inhibited the AR allowed the sperm cells to undergo successful AR induction by calcium ionophore.
Inflammatory Bowel Diseases | 2012
Kinan Rahal; Phyllissa Schmiedlin-Ren; Jeremy Adler; Muhammad Dhanani; Victoria Sultani; Ahren C. Rittershaus; J. Zhu; Barbara J. McKenna; Gregory M. Christman; Ellen M. Zimmermann
Background: Resveratrol has antiinflammatory and antifibrotic effects. Resveratrol decreases proliferation and collagen synthesis by intestinal smooth muscle cells. We hypothesized that resveratrol would decrease inflammation and fibrosis in an animal model of Crohns disease. Methods: Peptidoglycan‐polysaccharide (PG‐PS) or human serum albumin (HSA) was injected into the bowel wall of Lewis rats at laparotomy. Resveratrol or vehicle was administered daily by gavage 1–27 days postinjection. On day 28, gross abdominal and histologic findings were scored. Cecal collagen content was measured by colorimetric analysis of digital images of trichrome‐stained sections. Cecal levels of procollagen, cytokine, and growth factor mRNAs were determined. Results: PG‐PS‐injected rats (vehicle‐treated) developed more fibrosis than HSA‐injected rats by all measurements: gross abdominal score (P < 0.001), cecal collagen content (P = 0.04), and procollagen I and III mRNAs (P ≤ 0.0007). PG‐PS‐injected rats treated with 40 mg/kg resveratrol showed a trend toward decreased gross abdominal score, inflammatory cytokine mRNAs, and procollagen mRNAs. PG‐PS‐injected rats treated with 100 mg/kg resveratrol had lower inflammatory cytokine mRNAs (IL‐1&bgr; [3.50 ± 1.08 vs. 10.79 ± 1.88, P = 0.005], IL‐6 [17.11 ± 9.22 vs. 45.64 ± 8.83, P = 0.03], tumor necrosis factor alpha (TNF‐&agr;) [0.80 ± 0.14 vs. 1.89 ± 0.22, P = 0.002]), transforming growth factor beta 1 (TGF‐&bgr;1) mRNA (2.24 ± 0.37 vs. 4.06 ± 0.58, P = 0.01), and histologic fibrosis score (6.4 ± 1.1 vs. 9.8 ± 1.0; P = 0.035) than those treated with vehicle. There were trends toward decreased gross abdominal score and decreased cecal collagen content. Procollagen I, procollagen III, and IGF‐I mRNAs also trended downward. Conclusions: Resveratrol decreases inflammatory cytokines and TGF‐&bgr;1 in the PG‐PS model of Crohns disease and demonstrates a promising trend in decreasing tissue fibrosis. These findings may have therapeutic applications in inflammatory bowel disease. (Inflamm Bowel Dis 2011;)