Brain Aromatase and the Regulation of Sexual Activity in Male Mice.

The biologically active estrogen estradiol has important roles in adult brain physiology and sexual behavior. A single gene, Cyp19a1, encodes aromatase, the enzyme that catalyzes the conversion of testosterone to estradiol in the testis and brain of male mice. Estradiol formation was shown to regulate sexual activity in various species, but the relative contributions to sexual behavior of estrogen that arises in the brain versus from the gonads remained unclear. To determine the role of brain aromatase in regulating male sexual activity, we generated a brain-specific aromatase knockout (bArKO) mouse. A newly generated whole-body total aromatase knockout mouse of the same genetic background served as a positive control. Here we demonstrate that local aromatase expression and estrogen production in the brain is partially required for male sexual behavior and sex hormone homeostasis. Male bArKO mice exhibited decreased sexual activity in the presence of strikingly elevated circulating testosterone. In castrated adult bArKO mice, administration of testosterone only partially restored sexual behavior; full sexual behavior, however, was achieved only when both estradiol and testosterone were administered together. Thus, aromatase in the brain is, in part, necessary for testosterone-dependent male sexual activity. We also found that brain aromatase is required for negative feedback regulation of circulating testosterone of testicular origin. Our findings suggest testosterone activates male sexual behavior in part via conversion to estradiol in the brain. These studies provide foundational evidence that sexual behavior may be modified through inhibition or enhancement of brain aromatase enzyme activity and/or utilization of selective estrogen receptor modulators.

Predicting venous thrombosis in patients undergoing elective splenectomy.

BACKGROUND: Venous thrombosis (VT) is an ongoing problem for patients undergoing elective splenectomy. There is limited data evaluating risk factors for VTs. An increase in platelet counts is commonly seen after splenectomy; however, there is a paucity of literature evaluating post-operative platelet counts as a risk factor for VTs in this patient cohort. The objective of this study was to determine the incidence of VT events and to use the platelet count as a predictor for VT development. METHODS: A retrospective review was undertaken at Brigham Women's Hospital, evaluating elective splenectomy patients between 1997 and 2018. Descriptive statistics were utilized to determine the incidence of VTs. Receiver operator characteristic (ROC) curves were utilized to identify platelet counts that could predict VTs. RESULTS: Five hundred and twenty splenectomies were included in the study of which 344 were completed in an open manner and 176 were done laparoscopically. The overall incidence of VT events was 6.7% (35/520), 6.1% (21/344) for open, and 8.0% (14/176) for laparoscopic approaches (p = 0.43). ROC curves demonstrated platelet counts to be a good predictor for the development of VTs with an area under the curve (AUC) of 0.77 (95% CI 0.69-0.86; p < 0.001) for all splenectomy patients, 0.70 (95% CI 0.59-0.81; p < 0.001) for those completed in an open manner, and 0.88 (95% CI 0.77-0.99; p < 0.001) for those done laparoscopically. The optimal platelet cutoff was found to be 545 for the overall splenectomy cohort, 457 for the open, and 659 for the laparoscopic cohorts. These platelet counts had a diagnostic accuracy that ranged from 61 to 86% and a negative predictive value (NPV) that ranged from 97 to 99%. CONCLUSION: These results suggest platelet cutoffs that predict VTs. This information can be used to individualize prophylactic strategies.

Laparoscopic versus open splenectomy for splenomegaly: the verdict is unclear.

BACKGROUND: The benefits of laparoscopic splenectomy (LS) over open splenectomy (OS) for normal-sized spleens have been well documented. However, the role of laparoscopy for moderate and massive splenomegaly is debated. METHODS: A retrospective review of patients undergoing elective splenectomy at one institution from 1997 to 2017 was conducted. Moderate and massive splenomegaly was defined as splenic weight of 500-1000 g and greater than 1000 g, respectively. We performed a 1:2 matching of laparoscopic to open splenectomy to control for differences in splenic weight. Differences in perioperative morbidity (infection, thromboembolism, reoperation, readmission), intraoperative factors (blood loss, operative time), length of stay, and mortality were examined. RESULTS: A total of 491 elective splenectomies were identified. 268 cases were for splenic weights greater than 500 g. After a 1:2 matching of LS:OS, we identified 22 LS and 44 matched OS for moderate splenomegaly. The LS group had longer mean operative times (178 vs. 107 min, p < 0.01), with similar length of stay and blood loss. For massive splenomegaly, 26 LS were identified and matched to 52 OS. LS had longer mean operative times (171 vs. 112 min, p < 0.01) and higher readmission rates (27% vs. 6%, p < 0.05). Other factors and outcomes did not differ between LS and OS for moderate or massive splenomegaly. The conversion rate for LS was higher for massive versus moderate splenomegaly, but was not statistically significant (35% vs. 14%, p = 0.09). CONCLUSIONS: LS for moderate and massive splenomegaly is associated with longer operative times. Other perioperative outcomes were comparable to OS, with no demonstrated benefits for LS. Although LS may be a feasible approach to moderate and massive splenomegaly, its benefits require further clarification in this patient population.

Shift from androgen to estrogen action causes abdominal muscle fibrosis, atrophy, and inguinal hernia in a transgenic male mouse model.

Inguinal hernia develops primarily in elderly men, and more than one in four men will undergo inguinal hernia repair during their lifetime. However, the underlying mechanisms behind hernia formation remain unknown. It is known that testosterone and estradiol can regulate skeletal muscle mass. We herein demonstrate that the conversion of testosterone to estradiol by the aromatase enzyme in lower abdominal muscle (LAM) tissue causes intense fibrosis, leading to muscle atrophy and inguinal hernia; an aromatase inhibitor entirely prevents this phenotype. LAM tissue is uniquely sensitive to estradiol because it expresses very high levels of estrogen receptor-α. Estradiol acts via estrogen receptor-α in LAM fibroblasts to activate pathways for proliferation and fibrosis that replaces atrophied myocytes, resulting in hernia formation. This is accompanied by decreased serum testosterone and decreased expression of the androgen receptor target genes in LAM tissue. These findings provide a mechanism for LAM tissue fibrosis and atrophy and suggest potential roles of future nonsurgical and preventive approaches in a subset of elderly men with a predisposition for hernia development.

Morbidity Associated with Urinary Diversion in the United States: A Contemporary Evaluation Using the NSQIP Database.

INTRODUCTION: We identified preoperative differences between patients undergoing incontinent vs continent diversion, and compared 30-day complication outcomes between the 2 procedures. METHODS: Using the NSQIP® (National Surgical Quality Improvement Program) database we identified patients undergoing urinary diversion incorporating bowel, with or without cystectomy, between 2010 and 2012. We compared preoperative characteristics, surgical parameters and 30-day postoperative outcomes. We stratified patients based on the continence status of the diversion as incontinent vs continent. RESULTS: We identified 1,959 urinary diversions in the NSQIP database, including 1,568 incontinent diversions (80.0%) and 391 continent diversions (20.0%). Significantly higher rates of chronic obstructive pulmonary disease (9.1% vs 4.3%), previous cardiac surgery (4.3% vs 1.8%), hypertension (63.3% vs 47.1%) and disseminated disease (4.7% vs 2.1%) were noted in patients undergoing incontinent diversion. Patients undergoing continent diversion were significantly more likely to have received preoperative chemotherapy (10.5% vs 5.2%). Operative time was longer for continent diversion (388 vs 336 minutes). Postoperative urinary tract infection (13.8% vs 7.9%) and sepsis rates (11.5% vs 7.9%) were significantly higher with continent diversion, whereas transfusion rates were higher with incontinent diversion (45.2% vs 37.1%). Thirty-day readmission rates (18.2% vs 15.6%), length of stay (10.2 vs 10.7 days), presence of at least 1 NSQIP captured complication (61.4% vs 64.0%) and mortality (1.5% vs 2.1%) were not statistically different between continent diversion and incontinent diversion. CONCLUSIONS: Urinary diversion incorporating bowel continues to carry a significant risk of postoperative morbidity. While continent diversion offers potential long-term advantages, these must be balanced against longer operative times and higher rates of postoperative infectious complications.

NSQIP® Indexed Complications Following Transurethral Bladder Tumor Resection and Contemporary Financial Implications.

INTRODUCTION: We determined the incidence of NSQIP (National Surgical Quality Improvement Project) indexed complications by tumor size and investigated the related financial implications based on contemporary reimbursement schedules. METHODS: Transurethral bladder tumor resection procedures performed from 2010 to 2012 were identified and stratified by size specific CPT coding. Preoperative characteristics, surgical parameters and 30-day perioperative outcomes were compared using chi-square analysis and Student's t-test. Financial data for all inpatient transurethral bladder tumor resections performed during the most recent fiscal year at our institution were collected and analyzed, and a comparison was made using up-to-date Medicare reimbursement schedules. RESULTS: We identified 8,116 cases, including 3,533 coded as small (43.3%), 2,734 medium (33.5%) and 1,849 large (22.6%). Large resections required longer operative time (small-25.8 minutes, medium-33.0 minutes, large-49.0 minutes, p <0.01) and length of stay (small-0.67 days, medium-1.1 days, large-1.9 days, p <0.006), and had higher rates of transfusion (small-0.74%, medium-1.5%, large-3.7%, p <0.001), sepsis (small-0.23%, medium-0.44%, large-0.92%, p <0.05), renal insufficiency (small-0.17%, medium-0.15%, large-0.60%, p <0.01) and 30-day mortality (small-0.2%, medium-1%, large-1.8%, p <0.05) independent of preoperative parameters. Large resections were also associated with higher rates of 30-day readmission (small-4.3%, medium-6.3%, large-9.4%, p <0.001) and reoperation (small-2.1%, medium-2.7%, large-4.5%, p <0.001). Institutional data demonstrate that the most common Diagnosis Related Group classification results in an operating loss when treating Medicare beneficiaries. CONCLUSIONS: Urologist selected coding directly correlates with NSQIP indexed postoperative complications. Many cases of transurethral bladder tumor resection with associated complications may result in financial loss for the performing institutions. Efforts to improve quality of care and reimbursement seem warranted.

An appraisal of the learning curve in robotic general surgery.

BACKGROUND: Robotic-assisted surgery is used with increasing frequency in general surgery for a variety of applications. In spite of this increase in usage, the learning curve is not yet defined. This study reviews the literature on the learning curve in robotic general surgery to inform adopters of the technology. METHODS: PubMed and EMBASE searches yielded 3690 abstracts published between July 1986 and March 2016. The abstracts were evaluated based on the following inclusion criteria: written in English, reporting original work, focus on general surgery operations, and with explicit statistical methods. RESULTS: Twenty-six full-length articles were included in final analysis. The articles described the learning curves in colorectal (9 articles, 35%), foregut/bariatric (8, 31%), biliary (5, 19%), and solid organ (4, 15%) surgery. Eighteen of 26 (69%) articles report single-surgeon experiences. Time was used as a measure of the learning curve in all studies (100%); outcomes were examined in 10 (38%). In 12 studies (46%), the authors identified three phases of the learning curve. Numbers of cases needed to achieve plateau performance were wide-ranging but overlapping for different kinds of operations: 19-128 cases for colorectal, 8-95 for foregut/bariatric, 20-48 for biliary, and 10-80 for solid organ surgery. CONCLUSION: Although robotic surgery is increasingly utilized in general surgery, the literature provides few guidelines on the learning curve for adoption. In this heterogeneous sample of reviewed articles, the number of cases needed to achieve plateau performance varies by case type and the learning curve may have multiple phases as surgeons add more complex cases to their case mix with growing experience. Time is the most common determinant for the learning curve. The literature lacks a uniform assessment of outcomes and complications, which would arguably reflect expertise in a more meaningful way than time to perform the operation alone.

What is the BMI threshold for open ventral hernia repair?

BACKGROUND: Overweight and obese patients are often asked to lose weight prior to ventral hernia repair (VHR). Improved outcomes are the reasons behind this strategy. Data regarding weight loss targets are scant, and it is not known at what body mass index (BMI) threshold postoperative complications increase. This study aimed to determine the threshold to allow proper patient counseling. METHODS: All patients who underwent open VHR at our institution between 2002 and 2015 captured in the NSQIP database were included. The primary outcome was defined as any (≥1) of 18 captured postoperative complications. Patients were divided into five groups based on BMI: group 1 (<25 kg/m2); 2 (25-29.99 kg/m2); 3 (30-34.99 kg/m2); 4 (35-39.99 kg/m2); and 5 (≥40 kg/m2). Multivariable, adjusted logistic regression was performed to evaluate the association between BMI categories and postoperative complications. RESULTS: Sixty seven of 922 patients (7.3 %) had at least one postoperative complication following VHR. The adjusted odds of complications in group 5 was 2.89 times greater compared to group 1 (OR 2.89; 95 % CI = 1.22-6.84), while there was no significant differences in odds of postoperative complications for groups 2, 3, or 4 compared to group 1. BMI category was also significantly associated with undergoing recurrent VHR, with 28.7 % of patients in group 5 having a recurrent repair compared to 14 % in patients in group 1 (p = 0.03). CONCLUSIONS: After VHR, complications are most likely to occur in patients with BMI ≥ 40 kg/m2. This subset of patients also had a significantly higher risk of undergoing surgery for a recurrent hernia, suggesting that this group of patients is likely to experience adverse outcomes after VHR and should be counseled to consider bariatric surgery prior to attempts at VHR. VHR at lower BMIs appears appropriate, and delaying therapy to achieve preoperative weight loss will likely offer no advantage.

A Urologist's Guide to Ingredients Found in Top-Selling Nutraceuticals for Men's Sexual Health.

INTRODUCTION: Use of supplements is common among men seeking urologic evaluation for sexual health matters. With a dizzying array of formulations available and little regulation on the dosage, purity, or ingredients found in these products, the health effects of nutraceuticals are often confusing to patients and medical practitioners alike. AIM: In this review, we set out to concisely summarize the data on ingredients found within the top-selling nutraceutical agents marketed for men's sexual health in order to provide a clinical guide for urologists. METHODS: We used sales data from the most popular retail provider of men's health supplements to identify the top-selling products marketed toward improvement of men's sexual health. We summarized the available information related to the ingredients, dosage, cost, and mechanism of action for these substances and performed an extensive literature search to identify and review the current evidence available for each of the most common ingredients found in these nutraceuticals. RESULTS: The top-selling nutraceuticals marked for men's sexual health contain a blend of multiple supplements (up to 33 in one formulation identified), the most common being ginseng, tribulus, zinc, horny goat weed, B complex vitamins/trace minerals, fenugreek, L-arginine, maca, DHEA, ginkgo, and yohimbine. The currently available medical literature evaluating the efficacy of these substances is generally of low quality. CONCLUSIONS: Despite the dearth of evidence supporting nutraceutical agents in the men's health arena, these substances are still commonly used by patients. As these products can affect the health and well-being of men presenting to a urology clinic, a familiarity with commonly used agents can help the urologist appropriately counsel their patients.

Estrogen receptor alpha (Esr1) regulates aromatase (Cyp19a1) expression in the mouse brain.

OBJECTIVES: Local estrogen production in the brain regulates critical functions including neuronal development, gonadotropin secretion and sexual behavior. In the mouse brain, a 36 kb distal promoter (l.f) regulates the Cyp19a1 gene that encodes aromatase, the key enzyme for estrogen biosynthesis. In vitro, promoter l.f interacts with estrogen receptor alpha (Esr1) to mediate Cyp19a1 mRNA expression and enzyme activity in mouse hypothalamic neuronal cell lines. The in vivo mechanisms that control mammalian brain aromatase expression during fetal and adult development, however, are not thoroughly understood. Our aim was to elucidate the basis of the in vivo connection between Esr1 and Cyp19a1. METHODS: Pregnant mice were sacrificed at gestational days 9, 11, 13, 15, 16, 19, 21 and the brain tissues of the fetuses were harvested along with five newborns at the age of postnatal day 2. Esr1KO (female) were also sacrificed and their hypothalamus were excised out. Then both fetuses and adults RNA were isolated, reverse transcribed and amplified employing primers specific for Esr1 and Cyp19a1 with Real time PCR. RESULTS: In the fetal mouse brain, Cyp19a1 mRNA levels are inversely correlated with estrogen receptor alpha (Esr1) mRNA levels in a temporal manner. Moreover, Cyp19a1 mRNA levels increased in the hypothalamus of estrogen receptor-alpha knockout female mice (Esr1KO). CONCLUSION: Taken together, our findings might indicate that Esr1 has crucial roles in the in vivo regulation of aromatase expression in the brain during fetal and adult life.

Genome-wide DNA methylation analysis predicts an epigenetic switch for GATA factor expression in endometriosis.

Endometriosis is a gynecological disease defined by the extrauterine growth of endometrial-like cells that cause chronic pain and infertility. The disease is limited to primates that exhibit spontaneous decidualization, and diseased cells are characterized by significant defects in the steroid-dependent genetic pathways that typify this process. Altered DNA methylation may underlie these defects, but few regions with differential methylation have been implicated in the disease. We mapped genome-wide differences in DNA methylation between healthy human endometrial and endometriotic stromal cells and correlated this with gene expression using an interaction analysis strategy. We identified 42,248 differentially methylated CpGs in endometriosis compared to healthy cells. These extensive differences were not unidirectional, but were focused intragenically and at sites distal to classic CpG islands where methylation status was typically negatively correlated with gene expression. Significant differences in methylation were mapped to 403 genes, which included a disproportionally large number of transcription factors. Furthermore, many of these genes are implicated in the pathology of endometriosis and decidualization. Our results tremendously improve the scope and resolution of differential methylation affecting the HOX gene clusters, nuclear receptor genes, and intriguingly the GATA family of transcription factors. Functional analysis of the GATA family revealed that GATA2 regulates key genes necessary for the hormone-driven differentiation of healthy stromal cells, but is hypermethylated and repressed in endometriotic cells. GATA6, which is hypomethylated and abundant in endometriotic cells, potently blocked hormone sensitivity, repressed GATA2, and induced markers of endometriosis when expressed in healthy endometrial cells. The unique epigenetic fingerprint in endometriosis suggests DNA methylation is an integral component of the disease, and identifies a novel role for the GATA family as key regulators of uterine physiology-aberrant DNA methylation in endometriotic cells correlates with a shift in GATA isoform expression that facilitates progesterone resistance and disease progression.

Paracrine activation of WNT/ß-catenin pathway in uterine leiomyoma stem cells promotes tumor growth.

Uterine leiomyomas are extremely common estrogen and progesterone-dependent tumors of the myometrium and cause irregular uterine bleeding, severe anemia, and recurrent pregnancy loss in 15-30% of reproductive-age women. Each leiomyoma is thought to arise from a single mutated myometrial smooth muscle stem cell. Leiomyoma side-population (LMSP) cells comprising 1% of all tumor cells and displaying tumor-initiating stem cell characteristics are essential for estrogen- and progesterone-dependent in vivo growth of tumors, although they have remarkably lower estrogen/progesterone receptor levels than mature myometrial or leiomyoma cells. However, how estrogen/progesterone regulates the growth of LMSP cells via mature neighboring cells is unknown. Here, we demonstrate a critical paracrine role of the wingless-type (WNT)/ß-catenin pathway in estrogen/progesterone-dependent tumorigenesis, involving LMSP and differentiated myometrial or leiomyoma cells. Estrogen/progesterone treatment of mature myometrial cells induced expression of WNT11 and WNT16, which remained constitutively elevated in leiomyoma tissues. In LMSP cells cocultured with mature myometrial cells, estrogen-progesterone selectively induced nuclear translocation of ß-catenin and induced transcriptional activity of its heterodimeric partner T-cell factor and their target gene AXIN2, leading to the proliferation of LMSP cells. This effect could be blocked by a WNT antagonist. Ectopic expression of inhibitor of ß-catenin and T-cell factor 4 in LMSP cells, but not in mature leiomyoma cells, blocked the estrogen/progesterone-dependent growth of human tumors in vivo. We uncovered a paracrine role of the WNT/ß-catenin pathway that enables mature myometrial or leiomyoma cells to send mitogenic signals to neighboring tissue stem cells in response to estrogen and progesterone, leading to the growth of uterine leiomyomas.

Contemporary management of adult intussusception: who needs a resection?

BACKGROUND: Surgical resection is often recommended in adults with intestinal intussusception (AI) because of its potential association with malignancy. We provide a contemporary algorithm for managing AI by focusing on the probability of discovering a lead point. METHODS: This is a retrospective study of adult patients with computed tomography (CT)-confirmed intussusception who underwent operative management of AI between 1996 and 2011 at a single academic institution. RESULTS: Sixty-four patients were diagnosed with AI by CT scan and then managed operatively. The incidence of colonic (CI), small bowel (SBI), and retrograde intussusception (RI) was 14, 55, and 31 %, respectively. All patients with CI had a lead point, whereas none were found among patients with RI. Some 46 % of patients with SBI had a lead point. The probability of discovering a lead point in SBI was increased by past history of malignancy (RR, 3.7, p < 0.001), a mass seen on preoperative CT scan (RR, 2.9, p = 0.005), and age over 60 years (RR, 2.2, p = 0.07). CONCLUSIONS: A pathologic lead point is likely with CI but not with RI. Patients with SBI who are over the age of 60 years and have a history of malignancy or a mass noted on CT scan have a higher likelihood of harboring a pathologic lead point.

A humanized pattern of aromatase expression is associated with mammary hyperplasia in mice.

Aromatase is essential for estrogen production and is the target of aromatase inhibitors, the most effective endocrine treatment for postmenopausal breast cancer. Peripheral tissues in women, including the breast, express aromatase via alternative promoters. Female mice lack the promoters that drive aromatase expression in peripheral tissues; thus, we generated a transgenic humanized aromatase (Arom(hum)) mouse line containing a single copy of the human aromatase gene to study the link between aromatase expression in mammary adipose tissue and breast pathology. Arom(hum) mice expressed human aromatase, driven by the proximal human promoters II and I.3 and the distal promoter I.4, in breast adipose fibroblasts and myoepithelial cells. Estrogen levels in the breast tissue of Arom(hum) mice were higher than in wild-type mice, whereas circulating levels were similar. Arom(hum) mice exhibited accelerated mammary duct elongation at puberty and an increased incidence of lobuloalveolar breast hyperplasia associated with increased signal transducer and activator of transcription-5 phosphorylation at 24 and 64 wk. Hyperplastic epithelial cells showed remarkably increased proliferative activity. Thus, we demonstrated that the human aromatase gene can be expressed via its native promoters in a wide variety of mouse tissues and in a distribution pattern nearly identical to that of humans. Locally increased tissue levels, but not circulating levels, of estrogen appeared to exert hyperplastic effects on the mammary gland. This novel mouse model will be valuable for developing tissue-specific aromatase inhibition strategies.

Laparoscopic cholecystectomy after a quarter century: why do we still convert?

BACKGROUND: Laparoscopic cholecystectomy (LC) is the gold standard procedure for gallbladder removal. However, conversion to open surgery is sometimes needed. The factors underlying a surgeon's decision to convert a laparoscopic case to an open case are complex and poorly understood. With decreasing experience in open cholecystectomy, this procedure is however no longer the "safe" alternative it once was. With such an impending paradigm shift, this study aimed to identify the main reasons for conversion and ultimately to develop guidelines to help reduce the conversion rates. METHODS: Using the National Surgical Quality Improvement Program (NSQIP) database and financial records, the authors retrospectively reviewed 1,193 cholecystectomies performed at their institution from 2002 to 2009 and identified 70 conversions. Two independent surgeons reviewed the operative notes and determined the reasons for conversion. The number of ports at the time and the extent of dissection before conversion were assessed and used to create new conversion categories. Hospital length of stay (LOS), 30-day complications, operative times and charges, and hospital charges were compared between the new groups. RESULTS: In 91% of conversion cases, the conversion was elective. In 49% of these conversions, the number of ports was fewer than four. According to the new conversion categories, most conversions were performed after minimal or no attempt at dissection. There were no differences in LOS, complications, operating room charges, or hospital charges between categories. Of the six emergent conversions (9%), bleeding and concern about common bile duct (CBD) injury were the main reasons. One CBD injury occurred. CONCLUSIONS: In 49% of the cases, conversion was performed without a genuine attempt at laparoscopic dissection. Considering this new insight into the circumstances of conversion, the authors recommend that surgeons make a genuine effort at a laparoscopic approach, as reflected by placing four ports and trying to elevate the gallbladder before converting a case to an open approach.

Aromatase, breast cancer and obesity: a complex interaction.

Obesity has been associated with abnormally high expression of the enzyme aromatase in the breast, increased local estrogen production, and predisposition to breast hyperplasia and cancer. Increased adiposity in postmenopausal women may trigger signaling pathways that induce aromatase expression. In breast adipose fibroblasts, increased TNF production may induce the distal aromatase promoter, whereas increased local PGE(2) production may induce the proximal promoter region. We review here the mechanisms that control aromatase gene expression in breast adipose tissue, and the paracrine interactions between malignant breast epithelial cells and the surrounding adipose fibroblasts. Systematic characterization of these signaling pathways will facilitate the identification of potential drug targets to selectively reduce aromatase expression and excessive estrogen production, with therapeutic benefit.

Aromatase promoter I.f is regulated by progesterone receptor in mouse hypothalamic neuronal cell lines.

Aromatase catalyzes the conversion of C(19) steroids to estrogens. Aromatase and progesterone, both of which function at different steps of steroidogenesis, are crucial for the sexually dimorphic development of the fetal brain and the regulation of gonadotropin secretion and sexual interest in adults. The aromatase gene (Cyp19a1) is selectively expressed in distinct neurons of the mouse hypothalamus through a distal brain-specific promoter, I.f, located ∼40 kb upstream of the coding region. However, the regulation of aromatase expression in the brain is not well understood. In this study, we investigated a short feedback effect of progesterone analogues on aromatase mRNA expression and enzyme activity in estrogen receptor α (Esr1)-positive or -negative mouse embryonic hypothalamic neuronal cell lines that express aromatase via promoter I.f. In a hypothalamic neuronal cell line that highly expresses aromatase, progesterone receptor (Pgr), and Esr1, a progesterone agonist, R5020, inhibited aromatase mRNA level and enzyme activity. The inhibitory effect of R5020 was reversed by its antagonist, RU486. Deletion mutants of promoter I.f suggested that inhibition of aromatase expression by progesterone is conferred by the nt -1000/-500 region, and R5020 enhanced binding of Pgr to the nt -800/-600 region of promoter I.f. Small interfering RNA knockdown of Pgr eliminated progesterone-dependent inhibition of aromatase mRNA and enzyme activity. Taken together, progesterone enhances recruitment of Pgr to specific regions of the promoter I.f of Cyp19a1 and regulates aromatase expression in hypothalamic neurons.

Malpractice carrier underwrites Fundamentals of Laparoscopic Surgery training and testing: a benchmark for patient safety.

BACKGROUND: Fundamentals of Laparoscopic Surgery (FLS) is a validated program developed by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) to educate and assess competency in minimally invasive surgery (MIS). This study reports the first malpractice carrier-sponsored FLS course for surgeons in practice underwritten by the Controlled Risk Insurance Company of Harvard's Risk Management Foundation (CRICO/RMF). The study investigated the participating surgeons' pattern of MIS skills acquisition, subjective laparoscopic comfort level, operative activity, and perception of the FLS role in surgical education, credentialing, and patient safety. METHODS: A 1-day postgraduate continuous medical education (CME) course consisted of didactic presentations of the leading MIS faculty, proctored FLS hands-on training, psychomotor testing, and cognitive computer-based examination. Voluntary anonymous pre- and postcourse surveys were distributed to the participants at registration and at completion of both the didactic teaching and the skills modules of the program. RESULTS: The course was attended by 37 practicing surgeons in the Harvard system, and 86% of the survey forms were returned. The major driving forces for attending the course were directive from the chief/chairman (50%), improvement in MIS didactic knowledge (56%), and the belief that FLS would become a standard such as advanced trauma life support (ATLS), advanced cardiac life support (ACLS), or the like (53%). Surgeons reported that the FLS exam content was appropriate (Likert 4.41 +/- 0.91) and that mastery of the course material would improve safety (Likert 4.13 +/- 0.79) and technical knowledge of MIS (Likert 4.03 +/- 1.00). CONCLUSIONS: This unique cooperative effort between a liability carrier, a professional surgical society, and proactive surgeons should be considered a model for advancing competency and patient safety. The survey results indicate a positive view of FLS in surgical training, safety, and MIS education.

A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue.

BACKGROUND: Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testis-specific). It remains unknown whether aromatase is expressed in other mouse tissues via novel and tissue-specific promoters. METHODS: Real-time PCR was used to examine the aromatase expression levels in various C57BL/6 mouse tissues. 5'-rapid amplification of cDNA ends (5'-RACE) was used to determine the transcriptional start sites of Cyp19a1 transcripts. Promoter activity was measured using serial deletion mutants of DNA fused to the luciferase reporter gene. Primary mouse adipose fibroblasts were isolated and cultured from 16-week-old mouse gonadal fat pads. RESULTS: We systematically analyzed Cyp19a1 expression in a large number of mouse tissues, and demonstrated for the first time that aromatase was expressed in the male but not female gonadal fat pad. Subcutaneous and brown adipose tissue did not contain detectable Cyp19a1 mRNA. We used 5'-RACE to clone a novel gonadal fat-specific untranslated first exon, which is spliced onto a common junction 15 bp upstream of the translation start site. This adipose-specific first exon was mapped to approximately 75 kb upstream of the translation start site. Transfection of luciferase reporter gene plasmids containing the promoter region upstream of the adipose-specific first exon into murine 3T3-L1 adipose fibroblasts demonstrated significant basal promoter activity conferred primarily by the sequence located at -343/-1 bp. Dexamethasone significantly induced activity of this adipose-specific promoter region. Adipose-specific Cyp19a1 mRNA was expressed in primary mouse adipose fibroblasts and significantly induced by dexamethasone alone or serum plus dexamethasone. CONCLUSION: Taken together, this research identified a novel, adipose-specific first exon of Cyp19a1 and its hormonally regulated promoter region in male murine gonadal fat. These results expand the known 5'-regulatory region of the murine Cyp19a1 gene to 75 kb upstream of the translation start site. Cyp19a1 expression in mouse adipose tissue may play an important role in reproductive biology and lipid metabolism.

Distal pancreatectomy is not associated with increased perioperative morbidity when performed as part of a multivisceral resection.

PURPOSE: To evaluate the indications for and the outcomes from distal pancreatectomy. METHODS: Retrospective chart review of 171 patients who underwent distal pancreatectomy at Brigham and Women's Hospital between January 1996 and August 2005. RESULTS: Nearly one-third of distal pancreatectomies were performed as part of an en bloc resection for a contiguous or metastatic tumor. Fifty-six percent of the patients underwent a standard distal pancreatectomy +/- splenectomy (group 1), whereas 44% of distal pancreatic resections included additional organs or contiguous intraperitoneal or retroperitoneal tumor (group 2). The overall post-operative complication rate was 37%; the most common complication was pancreatic duct leak (23%). When compared to patients undergoing standard distal pancreatectomy, those with a more extensive resection including multiple viscera and/or metastatic or contiguous tumor resection had no significant difference in overall complication rate (35% v. 39%, p = 0.75), leak rate (25% v. 20%, p = 0.47), new-onset insulin-dependent diabetes mellitus (3% v. 4%, p = 1.0), and mortality (2% v. 4%, p = 0.656). CONCLUSION: This series includes a large number of patients in whom distal pancreatectomy was performed as part of a multivisceral resection or with en bloc resection of contiguous tumor. Complications were no different in these patients when compared to patients undergoing straightforward distal pancreatectomy.