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The evaluation of cancer risk among patients treated for infertility is complex, given the need to consider indications for use, treatment details, and the effects of other factors (including parity status) that independently affect cancer risk. Many studies have had methodologic limitations. Recent studies that have overcome some of these limitations have not confirmed a link between drug use and invasive ovarian cancers, although there is still a lingering question as to whether borderline tumors might be increased. It is unclear whether this merely reflects increased surveillance. Investigations regarding breast cancer risk have produced inconsistent results. In contrast, an increasing number of studies suggest that fertility drugs may have a special predisposition for the development of uterine cancers, of interest given that these tumors are recognized as particularly hormonally responsive. Additional studies are needed to clarify the effects on cancer risk of fertility drugs, especially those used in conjunction with in vitro fertilization. Because many women who have received such treatments are still relatively young, further monitoring should be pursued in large well-designed studies that enable assessment of effects within a variety of subgroups defined by both patient and disease characteristics.
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OBJECTIVE - The objective of the study was to characterize the variations in normal cervical spectra because of menopausal status and location within the menstrual cycle. Using the information obtained, the accuracy of Raman spectroscopy to diagnose low-grade squamous intraepithelial lesion (LGSIL) will be improved.
STUDY DESIGN - A total of 133 patients undergoing either colposcopy or Papanicolaou smear were recruited from either Vanderbilt University or Tri-State Women's Health. Raman spectra were collected from both normal and diseased areas. The data were processed and analyzed using a multiclass discrimination and classification algorithm to determine whether the spectra were correctly classified.
RESULTS - Stratifying the data by menopausal state resulted in correctly classifying LGSIL 97% of the time (from 74%).
CONCLUSION - This study brings Raman spectroscopy one step closer to clinical use by improving the sensitivity to differentiate LGSIL from normal.
The TAL1/SCL transcription factor is essential for haematopoietic commitment and vascular remodelling during embryonic development. To help clarify its role in postnatal vascular processes, we characterized the expression of mouse Tal1 protein by immunocytochemistry in several experimental models of blood vessel formation. In adult mice, Tal1 protein was expressed in rare microvascular endothelial cells and in extravascular cells provisionally identified as endothelial progenitors from their morphology, proximity to vessels and expression of vascular endothelial growth factor receptor-2. The number of Tal1-expressing endothelial cells increased significantly but transiently in all the models-hormone-induced ovulation, wound healing and tumour development. Finally, Tal1 protein was detected in the nuclei of newly formed lymphatic endothelial cells in tumour-bearing animals. These results show that TAL1 is expressed by vascular endothelial cells and endothelial progenitors at sites of physiological and pathological neovascularization and suggest a role for this transcription factor in adult vasculogenesis. This work also provides the first evidence for TAL1 expression in lymphangiogenesis.
Copyright (c) 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
OBJECTIVE - An association between assisted reproductive technique (ART) and specific imprinting mutations, such as Beckwith-Wiedemann syndrome (BWS), has recently been documented. Based on experiments in farm animals that demonstrated an association between alterations in culture media during ART and large offspring syndrome, we hypothesized that the culture media could be implicated as a common factor among the children with BWS conceived after ART.
DESIGN - Retrospective case series.
SETTING - Registry from Academic Medical Center.
PATIENT(S) - Nineteen children born after ART were identified within the registry.
MAIN OUTCOME MEASURE(S) - Demographics of patients, type of ART, culture media, IVF parameters.
RESULT(S) - Twelve of the 19 medical records from the reproductive endocrine centers were successfully obtained. Ten of 12 mothers of children with BWS had IVF, but no single, consistent culture media was used in this group. Half of the patients underwent IVF with intracytoplasmic sperm injection (ICSI; n = 5), whereas the other half had routine IVF. One child was conceived through clomiphene citrate (CC) stimulation and artificial insemination, whereas another patient conceived through gonadotropin stimulation with intrauterine insemination (IUI). The gonadotropin dosage and quantity of embryos transferred also varied significantly. The only consistent finding was that all 12 women received some type of ovarian stimulation medication.
CONCLUSION(S) - Large epidemiologic studies are needed to further study the association between BWS and ART.
PURPOSE - We compared the cost-effectiveness of 4 treatment strategies for varicocele related infertility from the perspective of the health care payor and patient.
MATERIALS AND METHODS - Cost-effectiveness analysis was performed by studying 4 treatment strategies, namely observation, surgical varicocelectomy followed by in vitro fertilization (IVF) if unsuccessful, gonadotropin stimulated intrauterine insemination (IUI) followed by IVF if unsuccessful, and immediate IVF. The main outcome measure was incremental cost per live delivery of any number of newborns.
RESULTS - Immediate IVF cost more per live delivery and was less effective than varicocelectomy/IVF or IUI/IVF. When electing the latter 2 procedures, the preferred approach depended on the choice of perspective. From the health care payor viewpoint each additional birth that resulted from choosing varicocelectomy/IVF over observation cost $52,152, while each additional birth that occurred by electing IUI/IVF over varicocelectomy/IVF cost $561,423. From the patient perspective, while varicocelectomy/IVF resulted in improved outcomes over observation, a rational decision maker would always be willing to pay the slightly higher cost of IUI/IVF (incremental cost per live birth versus observation $27,371) for the added benefit in effectiveness if they were initially willing to invest in varicocelectomy/IVF (incremental cost per live birth versus observation $27,618).
CONCLUSIONS - The optimal choice of treatment for varicocele related infertility depends strongly on the decision maker perspective. Regardless of perspective the most technologically advanced treatment, that is immediate IVF, is never favored. The findings of this study should be used to counsel infertile patients with varicocele that immediate IVF is not cost-effective.
Cyclooxygenase (COX)-derived prostaglandins are critical in female reproduction. Gene targeting studies show that ovulation, fertilization, implantation, and decidualization are defective in COX-2 deficient mice. We used genetic and pharmacologic approaches to perturb COX function and examine the differential and synergistic effects of inhibition of COX-1, COX-2, or of both isoforms on reproductive outcomes during early pregnancy in mice. The results demonstrate that simultaneous inhibition of COX-1 and COX-2 produces more severe effects on early pregnancy events than inhibition of either isoform alone. The effects of pharmacological inhibition of COX-2 on female reproductive functions were less severe than the null mutation of the COX-2 gene. A combined approach showed that COX-2 inhibition in COX-1(-/-) mice induced complete reproductive failure, suggesting a lack of alternative sources of prostaglandin synthesis. This investigation raises caution regarding the indiscriminate use of COX inhibitors and shows for the first time the distinct and overlapping pathways of the cyclooxygenase systems in female reproduction.
Previous observations of ovulation and fertilization defects in cyclooxygenase-2 (COX-2)-deficient mice suggested that COX-2-derived ovarian prostaglandins (PGs) participate in these events. However, the specific PG and its mode of action were unknown. Subsequent studies revealed that mice deficient in EP(2), a PGE(2)-receptor subtype, have reduced litter size, apparently resulting from poor ovulation but more dramatically from impaired fertilization. Using a superovulation regimen and in vitro culture system, we demonstrate herein that the ovulatory process, not follicular growth, oocyte maturation, or fertilization, is primarily affected in adult COX-2- or EP(2)-deficient mice. Furthermore, our results show that in vitro-matured and -fertilized eggs are capable of subsequent preimplantation development. However, severely compromised ovulation in adult COX-2- or EP(2)-deficient mice is not manifested in immature (3-wk-old) COX-2- or EP(2)-deficient mice, suggesting that the process of ovulation is more dependent on PGs in adult mice. Although the processes of implantation and decidualization are defective in COX-2(-/-) mice, our present results demonstrate that these events are normal in EP(2)-deficient mice, as determined by embryo transfer and experimentally induced decidualization. Collectively, previous and present results suggest that whereas COX-2-derived PGE(2) is essential for ovulation via activation of EP(2), COX-2-derived prostacyclin is involved in implantation and decidualization via activation of peroxisome proliferator-activated receptor delta.
Caenorhabditis elegans oocytes, like those of most animals, arrest during meiotic prophase. Sperm promote the resumption of meiosis (maturation) and contraction of smooth muscle-like gonadal sheath cells, which are required for ovulation. We show that the major sperm cytoskeletal protein (MSP) is a bipartite signal for oocyte maturation and sheath contraction. MSP also functions in sperm locomotion, playing a role analogous to actin. Thus, during evolution, MSP has acquired extracellular signaling and intracellular cytoskeletal functions for reproduction. Proteins with MSP-like domains are found in plants, fungi, and other animals, suggesting that related signaling functions may exist in other phyla.
Prostaglandins (PGs) are ubiquitous lipid mediators derived from cyclooxygenase (COX) metabolism of arachidonic acid that exert a broad range of physiologic activities including modulation of inflammation, ovulation, and arterial blood pressure. The physiologic actions of PGs are mediated in part by their interaction with specific G-protein-coupled PG receptors. Eight PG receptors have been cloned, including four for the major COX metabolite, PGE2. The physiologic roles of the PGE2 receptors have been investigated utilizing subtype-selective agonists, localization of receptor mRNA expression, and creation of mice with targeted disruption of PG receptor genes. These analyses have delineated discrete roles for the various PG receptor subtypes. Recent studies on mice lacking the PGE2 EP2 receptor have implicated the PGE2 EP2 receptor subtype in arterial dilatation and salt-sensitive hypertension, and also indicate that this receptor plays a key role in female fertility. The EP2 receptor may thus prove to be a productive target for pharmacological intervention in the treatment of hypertension and infertility.
Desensitization of guanine nucleotide binding protein-coupled receptors is a ubiquitous phenomenon characterized by declining effector activity upon persistent agonist stimulation. The luteinizing hormone/choriogonadotropin receptor (LH/CGR) in ovarian follicles exhibits desensitization of effector adenylyl cyclase activity in response to the mid-cycle surge of LH. We have previously shown that uncoupling of the agonist-activated LH/CGR from the stimulatory G protein (G(s)) is dependent on GTP and attributable to binding of beta-arrestin present in adenylyl cyclase-rich follicular membrane fraction to the third intracellular (3i) loop of the receptor. Here, we report that LH/CGR-dependent desensitization is mimicked by ADP ribosylation factor nucleotide-binding site opener, a guanine nucleotide exchange factor of the small G proteins ADP ribosylation factors (Arfs) 1 and 6, and blocked by synthetic N-terminal Arf6 peptide, suggesting that the GTP-dependent step of LH/CGR desensitization is receptor-dependent Arf6 activation. Arf activation by GTP and ADP ribosylation factor nucelotide-binding site opener promotes the release of docked beta-arrestin from the membrane, making beta-arrestin available for LH/CGR; Arf6 but not Arf1 peptides block beta-arrestin release from the membrane. Thus, LH/CGR appears to activate two membrane delimited signaling cascades via two types of G proteins: heterotrimeric G(s) and small G protein Arf6. Arf6 activation releases docked beta-arrestin necessary for receptor desensitization, providing a feedback mechanism for receptor self-regulation.