Expression profiles of the nuclear receptors and their transcriptional coregulators during differentiation of neural stem cells.

Neural stem cells (NSCs) are pluripotent precursors with the ability to proliferate and differentiate into 3 neural cell lineages, neurons, astrocytes and oligodendrocytes. Elucidation of the mechanisms underlying these biologic processes is essential for understanding both physiologic and pathologic neural development and regeneration after injury. Nuclear hormone receptors (NRs) and their transcriptional coregulators also play crucial roles in neural development, functions and fate. To identify key NRs and their transcriptional regulators in NSC differentiation, we examined mRNA expression of 49 NRs and many of their coregulators during differentiation (0-5 days) of mouse embryonic NSCs induced by withdrawal of fibroblast growth factor-2 (FGF2). 37 out of 49 NRs were expressed in NSCs before induction of differentiation, while receptors known to play major roles in neural development, such as THRα, RXRs, RORs, TRs, and COUP-TFs, were highly expressed. CAR, which plays important roles in xenobiotic metabolism, was also highly expressed. FGF2 withdrawal induced mRNA expression of RORγ, RXRγ, and MR by over 20-fold. Most of the transcriptional coregulators examined were expressed basally and throughout differentiation without major changes, while FGF2 withdrawal strongly induced mRNA expression of several histone deacetylases (HDACs), including HDAC11. Dexamethasone and aldosterone, respectively a synthetic glucocorticoid and natural mineralocorticoid, increased NSC numbers and induced differentiation into neurons and astrocytes. These results indicate that the NRs and their coregulators are present and/or change their expression during NSC differentiation, suggesting that they may influence development of the central nervous system in the absence or presence of their ligands.

A model for initial care of the infertile couple.

Infertility affects an estimated 6.1 million women in the United States. Although more than 1.2 million women seek medical care for infertility each year, the majority drop out of the treatment process before achieving a successful pregnancy. An expert panel of five reproductive endocrinologists developed the Individualized Infertility Care Plan model to aid obstetrician-gynecologists and primary care physicians in streamlining the critical period encompassing diagnosis and initial treatment of the patient with uncomplicated infertility. The model emphasizes the importance of the physician's establishing a strong, lasting relationship with the infertile patient.

Hormone receptors and sexuality in the human female.

There is only inferential evidence based on observational studies and deductive reasoning that allows us to suppose there are hormone receptors in the human brain that are associated with libido. Data indicate that sexually active pubescent women have higher testosterone levels than matched controls. However, any number of nonhormonal events in puberty could be related to these changes. Another circuitous way to look at hormone libido receptors in the brain is by evaluating patients on birth control pills, in whom sexual activity paradoxically decreases. Sex hormone-binding globulin (SHBG) levels are increased, and, therefore, free testosterone levels seem to be affected by the use of birth control pills. In addition, the progestins in the pill are 19-nortestosterone derivatives, which may have some androgenic effect in their own right. Women on estrogen replacement therapy with the addition of testosterone seem to report increased libido, and there is subjective information that there is an increase in psychological sense of well-being. It has been well documented that females with adrenogenital syndrome are masculinized in utero, indicating imprinting on behavior. Because of the nature of the end point (e.g., increased libido), it is difficult to draw concrete conclusions on the presence of libido receptors in the human brain. Because the outcomes and end points are so soft, it is difficult to come to a consensus, and in fact this topic polarizes opinions of the pure scientist (objective) against the clinician (subjective).

Administration of progesterone before oocyte retrieval negatively affects the implantation rate.

OBJECTIVE: To compare the efficacy of two clinically accepted methods of progesterone supplementation during IVF. DESIGN: Prospective randomized trial. SETTING: A university-based IVF program. PATIENT(S): Three hundred fourteen stimulated IVF cycles between January 1993 and October 1994. INTERVENTION(S): Patients were assigned to one of two luteal phase progesterone regimens by a random permuted block design. In protocol A, 12.5 mg of IM progesterone was given 12 hours before oocyte retrieval; in protocol B, 25 mg of IM progesterone was given on the day of oocyte retrieval. MAIN OUTCOME MEASURE(S): Clinical pregnancy. RESULT(S): Patient demographic characteristics, including age, diagnosis, number of oocytes retrieved and fertilized, and number of embryos transferred, were not different between the two groups. There was no difference in the rate of cycle cancellation between the groups. One hundred forty ETs were performed in patients assigned to protocol A and 142 in patients assigned to protocol B. The clinical pregnancy rate in group A was 12.9% compared with 24.6% in group B. CONCLUSION(S): The administration of progesterone before oocyte retrieval is associated with a lower pregnancy rate than the administration of progesterone after oocyte retrieval.

Prevention of retrosternal adhesion formation in a rabbit model using bioresorbable films of polyethylene glycol and polylactic acid.

The purpose of this study was to test the efficacy of three bioresorbable films of polyethylene glycol (EO) and polylactic acid (LA) (EO/LA = 1.5, 2.5, and 3.0) in the prevention of adhesion formation between the epicardium and the sternum (retrosternal adhesions) in a rabbit model. Retrosternal adhesions were generated by sternotomy, pericardiotomy, and abrasion of the anterior epicardium. The adhesion barrier was placed between the epicardium and the sternum and sutured to the edge of the pericardium. Epicardial adhesions were evaluated 14-20 days later by assessing the area of the epicardium covered by adhesions. In the control rabbits, tenacious adhesions were observed between sternum and the central portion of epicardium (portion exposed through the pericardiotomy) which were difficult to dissect. When a bioresorbable film was placed over the pericardium, adhesion formation at the central strip of the epicardium (area between the sternum and the epicardium exposed through the pericardium) could be reduced or prevented. At this site, the areas of adhesion formation were 0% (EO/LA = 1.5), 8.4 +/- 2.8% (EO/LA = 2.5), and 5.6 +/- 4.7% (EO/LA = 3.0) of the central strip, significantly less than that observed in the control group, 78.0 +/- 5.8% (P < 0.01). At the anterior left and right and posterior apex of the heart (sites where the film was not placed), there were no differences between control and treatment groups. The films were completely resorbed at the time of necropsy in group EO/LA = 2.5 and 3.0. Small pieces of film were observed in group EO/LA = 1.5. In conclusion, the bioresorbable films [EO/LA = 1.5 (REPEL-CV), 2.5, or 3.0] were efficacious in the reduction of retrosternal adhesions to the epicardium.

Histologic alterations in dermal repair after thermal injury effects of topical angiotensin II.

Previously, we determined that quantitative assessment of epithelialization of the burn site could be performed using quantitative immunohistochemistry with an antibody to the protein cyclin. In this study, the effect of administration of angiotensin II (AII) on two histologic parameters of healing-the number of vascular channels at the burn site and the number of cells proliferating in hair follicles at the edge of the burn and within the burn-were evaluated. Beginning on day 4, vascular channels were noted within the burn site. Significantly more channels were noted in the burns treated with AII than those treated with placebo. With the exception of 3 postinjury days, this increase continued through day 17. Thereafter, the number of vascular channels peaked, and no differences were noted between control and treated burns. The number of cells proliferating in the hair follicle was also evaluated. At the edge of the burn, on average, 126 cells per microscope field (10x) were undergoing proliferation in the AII-treated burn on days 1 through 16 after burn injury. This is approximately a 50% increase over the number of cells proliferating in the placebo-treated burns. On day 12 (approximately 5 days before that observed in control burns), this AII-dependent proliferative response began to increase and peaked on day 19 at a level comparable to control. Thereafter, the proliferative response remained at this level through day 28. Within the area of the burn on days 1 through 15, 21 cells per medium power field on average (approximately 50% more than control) were undergoing proliferation. As on the edge of the burn, an AII-dependent increase in the number of cells proliferating in the hair follicles was observed during the latter phase of healing (on day 16 after the initiation of injury). However, unlike the edge of the burn, administration of AII led to a continued increase (approximately 50%) in the number of cells per field undergoing proliferation. AII increased neovascularization and cellular proliferation after burn injury. Through an increase in these two cellular events, AII may in turn accelerate healing of tissues after thermal injury.

Expression of cyclin protein after thermal skin injury in a guinea pig model.

In this study, an immunohistochemical stain for cyclin was used to quantitate proliferating elements in hair follicles at the edge of and within thermal burn areas. Biopsy specimens from thermal injury in the guinea pig (day 1 through day 28) were sectioned and stained with MIB-1 antibody, which recognizes cyclin, a protein expressed during epithelial cell proliferation. At the edge of the burn, 89 +/- 6.1 (SD) cells per medium power field (x 10, mpf) were MIB-1-positive on days 1 through 16. On day 17, the number of positive cells increased, reaching peak values on days 20 to 28 (271 +/- 12.7 cells/mpf). Within the burn, minimal staining was observed from day 1 to day 15 (12.7 +/- 1.6 cells/mpf). Thereafter the number of MIB-1-positive cells increased and plateaued with an average of 96.4 +/- 9.0 cells/mpf on days 20 through 28. In conclusion, immunohistochemical staining of dermal biopsy specimens with MIB-1 antibody may provide a quantitative method for the evaluation of tissue damage and healing after thermal injury.

Clinical problem of intraperitoneal postsurgical adhesion formation following general surgery and the use of adhesion prevention barriers.

Because of multiple studies demonstrating barrier efficacy, adhesion prevention adjuvants have received widespread acceptance in appropriate surgical settings. Many investigators are incorporating adhesion prevention barriers into their routine clinical practice and are achieving good results. Although both Seprafilm and Interceed barriers were shown to be safe and effective in all human clinical trials, their use did not eliminate adhesions in all patients. Efficacy of these barriers is limited to surgical situations in which the area in question can be completely covered. Physician acceptance is constrained by technical difficulties, including the need for hemostasis and removal of excess peritoneal fluid (Interceed), as well as limitations in application and handling properties within the surgical field (Seprafilm).

Inhibin, activin, and follistatin in reproductive medicine.

OBJECTIVE: To review the available information regarding the polypeptide factors inhibin, activin, and follistatin in reproductive physiology. DESIGN: The protein structure, tissue expression, regulation, and effects of these factors are outlined, with an emphasis on the reproductive tissues in both females and males. Although some information is only available in animal model systems, human data has been selected whenever possible. CONCLUSIONS: Inhibin and activin are closely related peptides with opposing actions, whereas follistatin is a structurally unrelated peptide that may act indirectly through modulation of inhibin-activin effects. These three peptides are secreted in highest levels by the adult gonads; however, they are also present in a wide variety of reproductive and nonreproductive tissues where they are believed to exert local, tissue-specific effects. Within the reproductive system, these peptides play a role in the regulation of gonadotropin biosynthesis and secretion, ovarian and placental steroidogenesis, and oocyte and spermatogonial maturation.

Ultrasound prediction of follicle volume: is the mean diameter reflective?

OBJECTIVE: To evaluate the relationship between 2 dimensional sonographic measurement of ovarian follicles and their actual volume. DESIGN: Prospective clinical study. SETTING: The in vitro fertilization (IVF) program of a University based, tertiary care hospital. PATIENTS AND INTERVENTIONS: Sonographic categorization by shape, and measurement of 96 individual ovarian follicles immediately prior to aspiration for IVF. Each follicle was aspirated under direct ultrasound guidance and the volume recorded. The 96 follicles were visualized in a total of 14 patients from whom 2 to 27 oocytes were obtained. MAIN OUTCOME MEASURE: Total volume of each follicle. RESULTS: Round and polygonal follicles exhibited a highly significant relationship between sonographically measured mean diameter and total follicle volume. The volume of follicles that were categorized as ellipsoid was not predicted by measurement of the longest diameter, shortest diameter or mean diameter. CONCLUSION: The mean diameter of round and polygonal follicles accurately predicts total follicular volume. However, clinical decisions in ovulation induction should be modified when the follicle shape is predominantly ellipsoid because the traditionally held belief that the sonographic measurement of the follicular diameter correlates with the follicular volume does not apply in those circumstances.

Aberrant estradiol flare despite gonadotropin-releasing hormone-agonist-induced suppression is associated with impaired implantation.

Our results confirm the previous report that rapid suppression by GnRH-a is favorable relative to delayed suppression (1). They further indicate that the pattern of E2 production during GnRH-a-induced ovarian suppression may be predictive of cycle outcome. We suggest that imperfect pituitary suppression of bioactive LH as indicated by an aberrant rise in E2 during GnRH-a down-regulation may compromise oocyte quality and ultimately impair implantation. Further study of follicular phase E2 response to GnRH-a suppression may provide a prognostic marker for implantation.

Clinical review 55: Advances in clinical in vitro fertilization.

The advances in human in vitro fertilization are excellent examples of the partnership between basic science and clinical medicine. It is reasonable to assume that future breakthroughs will result from this continued collaboration.

Failure of standard criteria to diagnose nonemergency ectopic pregnancies in a noninfertility patient population.

Algorithms for the diagnosis of ectopic pregnancy are applied independent of the patient population. However, patients may require care at various times of gestation or for different reasons. To examine the utility of the same diagnostic criteria for identifying an ectopic pregnancy in different patient populations, we evaluated women from the infertility clinic and the residents' gynecology clinic at Yale-New Haven Hospital. Sixty women with nonemergency ectopic pregnancies were identified, 38 from the infertility clinic and 22 from the residents' clinic. Although the most common symptoms were the same in both groups (abdominal pain, spotting/bleeding >3 days, dizziness, shoulder pain), they were significantly more frequent in women form the residents' clinic. Despite care by the same attending physicians, ruptured ectopic pregnancies were more than 3 times as likely to occur in the noninfertility patients, and half as likely to be treated laparoscopically (p<0.01). Patients from the residents' clinic also were more likely to have postoperative complications (p<0.5), and had over a threefold higher risk of receiving a blood transfusion. We conclude that criteria for diagnosis and intervention in ectopic pregnancy may have to be modified on the basis of characteristics of the patient population.

A case of endometrial cancer following endometrial ablation for dysfunctional uterine bleeding.

BACKGROUND: A concern voiced by critics of endometrial ablation is the possibility that cryptic endometrial adenocarcinoma may develop after such ablation. To date, this concern has been theoretical. CASE: A patient presented with vaginal bleeding and was diagnosed with endometrial carcinoma 5 years after ablation of the superficial endometrium. CONCLUSION: The possibility exists for endometrial carcinoma to develop years after endometrial ablation. Careful patient selection, thorough evaluation of any post-procedure bleeding, careful postoperative surveillance, and continued evaluation of the procedure and its long-term efficacy are indicated.

Ovulation induction with GnRH agonist and human menopausal gonadotropins: response in patients with one versus two ovaries.

OBJECTIVE: To examine the effect of oophorectomy on response to gonadotropin releasing hormone-agonist/human menopausal gonadotropin (GnRH-a/hMG) for in vitro fertilization (IVF). DESIGN: Retrospective review. SETTING: Tertiary care academic institution. PATIENTS: Ninety-one infertile patients undergoing IVF. Eighty-four women had two ovaries and seven had only one ovary. RESULTS: There was no difference observed between women with one versus two ovaries with regard to response to medications, hormone production, number of oocytes retrieved and fertilized, or the number of embryos cleaved and transferred. CONCLUSION: Women with only one ovary are at no reproductive disadvantage when undergoing ovulation induction for IVF.