The role of obesity in treatment planning for early-stage cervical cancer.

OBJECTIVES: Optimal management of obese patients with early-stage cervical cancer is debated despite evidence of non-inferior survival in obese patients undergoing radical hysterectomy with pelvic lymphadenectomy (RH) compared to primary radiation with or without radiosensitizing chemotherapy (RT). Objectives included describing patient factors affecting disposition to RH versus RT; comparing RH outcomes for obese (BMI >30 mg/m2) and non-obese patients; and comparing differences in recurrence free survival (RFS) and overall survival (OS). METHODS: This was a single institution cohort study of all cervical cancer patients who underwent RH or were candidates for RH based on clinical stage. Demographic, clinicopathologic and treatment outcomes were collected and analyzed. RESULTS: RT patients (n = 39, 15%) had a higher BMI (p = 0.004), older age (p < 0.001), more life-limiting comorbidities (LLC) (p < 0.001), larger tumor size (p = 0.001), and higher clinical stage (p = 0.013) compared to RH patients (n = 221, 85%). On multivariable survival analysis there was no difference in OS based on treatment modality; significant predictors of worse OS were larger tumor size, higher number of LLC and recurrence. Among the RH group, obese patients had a longer operative time (p = 0.01) and more LLC (p = 0.02); there were no differences in demographic or clinicopathologic characteristics, operative outcomes, RFS or OS compared to non-obese patients. CONCLUSION: In this cohort of RH-eligible cervical cancer patients, BMI was independently associated with disposition to RT. Studies demonstrate that RH is feasible and safe in obese patients with no difference in RFS or OS when compared to non-obese patients. Thus, the decision for disposition to RT should not be based on obesity alone.

Metformin and survival: Is there benefit in a cohort limited to diabetic women with endometrial, breast, or ovarian cancer?

OBJECTIVE: Evaluate the association between metformin and survival in women with Type 2 diabetes (T2DM) and breast, endometrial and ovarian cancer- 3 hormonally mediated cancers. METHODS: We evaluated outcomes in a cohort of 6225 women with T2DM with a new diagnosis of ovarian, breast or endometrial cancer from 2010 to 2019. We classified glycemic medications at time of first cancer diagnosis into 3 tiers in accordance with ADA guidelines. Approaches compared: (i) metformin (tier 1) vs. no glycemic medication, (ii) metformin vs tier 2 medications (sulfonylureas, thiazolidinediones, SGLT2-inhibitors, DPP4-inhibitors, alpha glucosidase-inhibitors, GLP-1 agonists), (iii) metformin vs tier 3 medications (insulins, amylinomimetics), and (iv) tier 2 vs tier 3 medications. Analyses included Cox proportional-hazards models, Kaplan-Meier curves, and conditional logistic regression in a risk set-sampled nested case-control matched on T2DM duration- all modeling survival. Models were adjusted for demographics, cancer type, A1C, T2DM duration, and number of office visits and hospitalizations. RESULTS: Metformin was the most used medication (n = 3232) and consistently demonstrated survival benefit compared with tier 2 and 3 medications, across all methods. Tier 3-users demonstrated highest risk of death when compared to metformin rather than tier 2 [adjHR = 1.83 (95% CI: 1.58, 2.13) vs. adjHR = 1.32 (95% CI: 1.11, 1.57)], despite similar baseline profiles between tier 1 and 2 users. CONCLUSIONS: Metformin users experienced increased survival even after accounting for surrogates of diabetes progression. Benefit extended beyond that seen in tier 2-users. Our findings, consistent with prior studies, indicate metformin use improves survival in women with T2DM and hormonally mediated women's cancers.

Phase I Trial Combining Chemokine-Targeting with Loco-Regional Chemoimmunotherapy for Recurrent, Platinum-Sensitive Ovarian Cancer Shows Induction of CXCR3 Ligands and Markers of Type 1 Immunity.

PURPOSE: Increased prevalence of cytotoxic T lymphocytes (CTL) in the tumor microenvironment (TME) predicts positive outcomes in patients with epithelial ovarian cancer (EOC), whereas the regulatory T cells (Treg) predict poor outcomes. Guided by the synergistic activity of TLR3 ligands, IFNα, and COX-2 blockers in selectively enhancing CTL-attractants but suppressing Treg-attractants, we tested a novel intraperitoneal chemoimmunotherapy combination (CITC), to assess its tolerability and TME-modulatory impact in patients with recurrent EOC. PATIENTS AND METHODS: Twelve patients were enrolled in phase I portion of the trial NCT02432378, and treated with intraperitoneal cisplatin, intraperitoneal rintatolimod (dsRNA, TLR3 ligand), and oral celecoxib (COX-2 blocker). Patients in cohorts 2, 3, and 4 also received intraperitoneal IFNα at 2, 6, and 18 million units (MU), respectively. Primary objectives were to evaluate safety, identify phase 2 recommended dose (P2RD), and characterize changes in the immune TME. Peritoneal resident cells and intraperitoneal wash fluid were profiled via NanoString and Meso Scale Discovery (MSD) multiplex assay, respectively. RESULTS: The P2RD of IFNα was 6 MU. Median progression-free survival and overall survival were 8.4 and 30 months, respectively. Longitudinal sampling of the peritoneal cavity via intraperitoneal washes demonstrated local upregulation of IFN-stimulated genes (ISG), including CTL-attracting chemokines (CXCL-9, -10, -11), MHC I/II, perforin, and granzymes. These changes were present 2 days after chemokine modulation and subsided within 1 week. CONCLUSIONS: The chemokine-modulating intraperitoneal-CITC is safe, tolerable, and associated with ISG changes that favor CTL chemoattraction and function. This combination (plus DC vaccine) will be tested in a phase II trial. See related commentary by Aranda et al., p. 1993.

Prevalence of intratumoral regulatory T cells expressing neuropilin-1 is associated with poorer outcomes in patients with cancer.

Despite the success of immune checkpoint blockade therapy, few strategies sufficiently overcome immunosuppression within the tumor microenvironment (TME). Targeting regulatory T cells (Tregs) is challenging, because perturbing intratumoral Treg function must be specific enough to avoid systemic inflammatory side effects. Thus, no Treg-targeted agents have proven both safe and efficacious in patients with cancer. Neuropilin-1 (NRP1) is recognized for its role in supporting intratumoral Treg function while being dispensable for peripheral homeostasis. Nonetheless, little is known about the biology of human NRP1+ Tregs and the signals that regulate NRP1 expression. Here, we report that NRP1 is preferentially expressed on intratumoral Tregs across six distinct cancer types compared to healthy donor peripheral blood [peripheral blood lymphocyte (PBL)] and site-matched, noncancer tissue. Furthermore, NRP1+ Treg prevalence is associated with reduced progression-free survival in head and neck cancer. Human NRP1+ Tregs have broad activation programs and elevated suppressive function. Unlike mouse Tregs, we demonstrate that NRP1 identifies a transient activation state of human Tregs driven by continuous T cell receptor (TCR) signaling through the mitogen-activated protein kinase pathway and interleukin-2 exposure. The prevalence of NRP1+ Tregs in patient PBL correlates with the intratumoral abundance of NRP1+ Tregs and may indicate higher disease burden. These findings support further clinical evaluation of NRP1 as a suitable therapeutic target to enhance antitumor immunity by inhibiting Treg function in the TME.

Do air gaps with image-guided vaginal cuff brachytherapy impact failure rates in patients with high-intermediate risk FIGO Stage I endometrial cancer?

PURPOSE: The aim of this study was to assess the impact of air gaps at the cylinder surface on the rate of vaginal cuff failure (VCF) after image-guided adjuvant vaginal cuff brachytherapy (VCBT) in the treatment of high-intermediate risk (HIR) FIGO (Fédération Internationale de Gynécologie et d'Obstétrique (International Federation of Gynecology and Obstetrics)) Stage I endometrial cancer. METHODS AND MATERIALS: A retrospective review of patients treated with image-guided VCBT from 2009 to 2016 for HIR FIGO Stage I endometrial cancer was performed. Air gaps present at the applicator surface on the first postinsertion CT were contoured. Vaginal cuff failure-free survival (VCFFS) was measured from the first fraction of VCBT to VCF. RESULTS: A total of 234 patients were identified. Air gaps were present on the first postinsertion CT scan in 82% of patients. The median number of air gaps was 2 (interquartile range [IQR] 1-3), median depth of the largest air gap was 2.7 mm (IQR 2.1-3.4 mm), and the median cumulative volume of air gaps was less than 0.1 cm3 (range < 0.1-0.7 cm3). At a median followup of 56 months (IQR 41-69), 12 patients (5%) experienced VCF, of which 4 had isolated VCF and 8 had synchronous pelvic or distant failure. Five-year VCFFS and isolated VCFFS were 96% (95% confidence interval 93-98%) and 98% (95% confidence interval 96-100%), respectively. On univariate analysis, no factors, including the presence, number, maximum depth, or cumulative volume of air gaps, were predictive for VCFFS. CONCLUSIONS: In this population, VCFFS remained high despite most patients having air gaps present on postinsertion CT scan.

Circulating CD14+ HLA-DRlo/- monocytic cells as a biomarker for epithelial ovarian cancer progression.

PROBLEM: Previous studies identified circulating CD14+ HLA-DRlo/- monocytic cells as an immune suppressive subset in solid malignancies, such as prostate, renal cell carcinoma, and pancreatic cancer. Such monocytic cells have been implicated not only in tumour progression but also as a potential barrier for immunotherapy. This study examined the relationship between the frequency of circulating monocytic cells and epithelial ovarian cancer (EOC) progression pre- and post-frontline chemotherapy, defined by disease stage, which is a leading prognostic factor for this malignancy. METHOD OF STUDY: Incident cases of 236 women with EOC were recruited and comprehensive flow cytometry was utilized to assess the frequency of peripheral blood CD33+ CD11b+ HLA-DR-/low CD14+ CD15- monocytic cells, henceforth termed CD14+ HLA-DRlo/- monocytic cells, prior to and after completion of frontline chemotherapy. Multivariable odds ratios (OR) were used to estimate the association between CD14+ HLA-DRlo/- monocytic cell percentages and disease stage. Wilcoxon signed-rank tests evaluated changes in these monocytic cell levels pre- and post-chemotherapy in a patient subset (n = 70). RESULTS: Patients with elevated frequencies of circulating CD14+ HLA-DRlo/- monocytic cells at diagnosis were at 3.33-fold greater odds of having advanced stage (III/IV) EOC (CI: 1.04-10.64), with a significant trend in increasing CD14+ HLA-DRlo/- monocytic cell levels (P = .04). There was a 2.02% median decrease of these monocytic cells post-chemotherapy among a subset of patients with advanced stage disease (P < .0001). CONCLUSION: These findings support the potential clinical relevance of CD14+ HLA-DRlo/- monocytic cells in EOC for prognosis and may indicate a non-invasive biomarker to measure disease progression.

Dose-escalated intensity modulated radiation therapy in patients with locally-advanced vulvar cancer - does it increase response rate?

PURPOSE: GOG 205 safely increased clinical (cCR) and pathologic complete response (pCR) in locally-advanced vulvar cancer through dose escalation using three-dimensional radiotherapy (RT). The aim of this study is to assess the response of dose-escalated intensity modulated radiotherapy (IMRT) in locally-advanced vulvar cancer. METHODS: A retrospective review of patients treated with dose-escalated (≥ 55Gy) IMRT from 2012 to 2018 for locally-advanced vulvar cancer was performed. Patients treated with preoperative or definitive intent were included. Rates of cCR and pCR were assessed, and predictors of disease-free survival (DFS) were analyzed using the Kaplan Meier method with log rank test between groups and a parsimonious multivariate Cox model. RESULTS: Median dose to the vulva was 66.0 Gy (Interquartile Range [IQR]: 66.0-68.0) for definitive and 59.4 Gy (IQR: 58.0-59.4) for preoperative IMRT. The overall rates of cCR and pCR were 76% and 70%, respectively. DFS at two years was 65% (95% Confidence Interval [CI] 50-80%) for all patients, 81% (95% CI 63% - 98%) for definitive IMRT, and 55% (95% CI 35% - 76%) for preoperative IMRT. On multivariate analysis, cCR predicted for disease-free survival (HR 0.21; 95% CI 0.06-0.76; p = 0.02), and pCR predicted for OS (HR 0.12; 95% CI 0.02-0.60; p = 0.01). Grade 3 acute and late RT toxicity was seen in 14 (29%) and 3 (6%) of patients, respectively. CONCLUSION: Dose-escalated IMRT for locally-advanced vulvar cancer is well tolerated, with rates of cCR and pCR that compare favorably with published data.

Survival and recurrence after intraperitoneal chemotherapy use: Retrospective review of ovarian cancer hospital registry data.

BACKGROUND: Intraperitoneal/intravenous chemotherapy (IP/IV) was associated with improved survival for ovarian cancer (OC) patients in several randomized clinical trials. However, the uptake of IP/IV in clinical practice is varied due to conflicting evidence about its impact on survival and recurrence. The aim of this study was to explore the uptake of IP/IV treatment and to evaluate its impact on survival and recurrence in OC patients. METHODS: Demographic and clinical information on OC patients (N = 2916) who underwent treatment for OC between 2000 and 2017 was obtained from the large healthcare system cancer registry. Duplicate records, grade 1, rare (eg, gelatinous carcinoma), and non-epithelial (eg, granulosa cell carcinoma) tumors were excluded. Kaplan-Meier survival curves were constructed to compare 5- and 10-year survival based on the chemotherapy type, surgery type, and stage. Multivariable Gray's piecewise constant time-varying coefficient models were fitted to evaluate the effect of IP/IV on adjusted hazard ratio (AHR) of OC survival and recurrence adjusting for potential confounders. RESULTS: The final sample consisted of 1846 OC patients, 14% (250/1846) of which received IP/IV chemotherapy. IP/IV was significantly associated with improved 10-year survival (P < .001). Multivariable Gray's model demonstrated that IP/IV therapy significantly reduced the AHR of death (AHR = 0.39-1.07, P < .001) with the beneficial effect gradually declining over time. Use of IP/IV chemotherapy had no impact on OC recurrence. CONCLUSIONS: These findings demonstrated that only a small fraction of eligible patients underwent IP/IV chemotherapy. We report a significant 10-year survival, but not necessarily recurrence benefit is associated with IP/IV chemotherapy compared to IV only, suggesting the need for novel ways of identifying patients who may benefit from IP/IV chemotherapy.

Phase II clinical trial of metformin as a cancer stem cell-targeting agent in ovarian cancer.

BACKGROUNDEpidemiologic studies suggest that metformin has antitumor effects. Laboratory studies indicate metformin impacts cancer stem-like cells (CSCs). As part of a phase II trial, we evaluated the impact of metformin on CSC number and on carcinoma-associated mesenchymal stem cells (CA-MSCs) and clinical outcomes in nondiabetic patients with advanced-stage epithelial ovarian cancer (EOC).METHODSThirty-eight patients with stage IIC (n = 1)/III (n = 25)/IV (n = 12) EOC were treated with either (a) neoadjuvant metformin, debulking surgery, and adjuvant chemotherapy plus metformin or (b) neoadjuvant chemotherapy and metformin, interval debulking surgery, and adjuvant chemotherapy plus metformin. Metformin-treated tumors, compared with historical controls, were evaluated for CSC number and chemotherapy response. Primary endpoints were (a) a 2-fold or greater reduction in aldehyde dehydrogenase-positive (ALDH+) CD133+ CSCs and (b) a relapse-free survival at 18 months of more than 50%.RESULTSMetformin was well tolerated. Median progression-free survival was 18.0 months (95% CI 14.0-21.6) with relapse-free survival at 18 months of 59.3% (95% CI 38.6-70.5). Median overall survival was 57.9 months (95% CI 28.0-not estimable). Tumors treated with metformin had a 2.4-fold decrease in ALDH+CD133+ CSCs and increased sensitivity to cisplatin ex vivo. Furthermore, metformin altered the methylation signature in CA-MSCs, which prevented CA-MSC-driven chemoresistance in vitro.CONCLUSIONTranslational studies confirm an impact of metformin on EOC CSCs and suggest epigenetic change in the tumor stroma may drive the platinum sensitivity ex vivo. Consistent with this, metformin therapy was associated with better-than-expected overall survival, supporting the use of metformin in phase III studies.TRIAL REGISTRATIONClinicalTrials.gov NCT01579812.

Use of flexible cystoscopy at time of artificial urinary sphincter placement.

INTRODUCTION: Artificial urinary sphincters (AUS) are used to treat significant urinary incontinence. Flexible cystoscopy at the time of AUS placement provides relevant intraoperative feedback including confirmation that the AUS is functioning, visualization of coaptation, and evaluation for urethral injury. Current guidelines for placement of an AUS do not include flexible cystoscopy. The objective was to evaluate whether flexible cystoscopy at time of AUS placement changed cuff size at the time of surgery. MATERIALS AND METHODS: A retrospective cohort study was performed to evaluate all patients undergoing AUS placement by a single surgeon between March 2013 and March 2017. The primary endpoint of the study was change in cuff size based on cystoscopy. RESULTS: A total of 109 AUS were placed in 96 patients. In five (4.6%) cases flexible cystoscopy identified a lack of coaptation of the urethra despite appropriate sizing which resulted in down-sizing of the cuff. Five patients were identified as having a bladder neck contracture that was previously unrecognized as clinic cystoscopy was performed by the referring urologist and was reportedly normal. Three patients developed postoperative infections, two of these patients had a history of multiple AUS placement and revisions and the third patient had a history of cystectomy and neobladder. CONCLUSIONS: Flexible cystoscopy at time of AUS placement changed the cuff size in nearly 5% of cases. Flexible cystoscopy at time of AUS placement provides valuable feedback and should be recommended for low volume prosthetic surgeons.

Neoadjuvant Chemoradiation Therapy Followed by Extrafascial Hysterectomy in Locally Advanced Type II Endometrial Cancer Clinically Extending to Cervix.

PURPOSE: The role of neoadjuvant chemoradiation therapy in locally advanced type II endometrial cancer is controversial. We thus aimed to present our experience with the hypothesis that neoadjuvant chemoradiation therapy is associated with similarly high rates of downstaging and locoregional control for type II endometrial cancer and type I endometrial cancer. METHODS AND MATERIALS: Thirty-four patients with type II endometrial cancer with clinical evidence of cervical ± parametrium involvement treated with neoadjuvant external beam radiation therapy (45-50.4 Gy in 25-28 fractions) and high-dose-rate brachytherapy with a median total dose of 20 Gy (range, 15-27.5) in 4 fractions (range, 3-5) and concurrent platinum chemotherapy ± adjuvant chemotherapy from 2008 to 2018 were retrospectively reviewed. Patients with type I pathologic diagnoses and those treated with definitive (rather than preoperative) intent were excluded. RESULTS: Pathologic characteristics were as follows: 38% were carcinosarcoma, 18% serous, and 24% clear cell. Ninety-four percent of patients were downstaged to an extrafascial hysterectomy, and 94% had negative surgical margins. The 2-year local control, regional control, distant control, disease-free survival, and overall survival were 87.8%, 81.3%, 76.3%, 52.5%, and 63.7%, respectively. There was 1 subacute grade 3 and 1 late grade 3 small bowel obstruction, directly attributable to radiation therapy. CONCLUSIONS: Neoadjuvant chemoradiation therapy effectively downstages the majority of locally advanced type II endometrial cancers, thereby increasing the likelihood of achieving complete resection with negative margins.

Diagnosis and Treatment of Ovarian Cancer.

Epithelial ovarian cancer classically presents with vague persistent gastrointestinal, urologic, or nonacute abdominal/pelvic symptoms (bloating, early satiety, discomfort). Ultimately, a pelvic examination or imaging identifies an adnexal mass typically with accompanied advanced peritoneal dissemination. Management involves aggressive cytoreductive surgery in combination with platinum and taxane chemotherapy. Over the last 20 years, optimal resection and mode and timing of chemotherapy have evolved. The authors review the initial diagnosis and management and present the available data and recommendations to guide the decision tree of when to use neoadjuvant, intraperitoneal, HIPEC, dose-dense, and maintenance chemotherapy in the front-line treatment of epithelial ovarian cancer.

Helicase-Driven Activation of NFκB-COX2 Pathway Mediates the Immunosuppressive Component of dsRNA-Driven Inflammation in the Human Tumor Microenvironment.

Presence of cytotoxic CD8+ T cells (CTL) in tumor microenvironments (TME) is critical for the effectiveness of immune therapies and patients' outcome, whereas regulatory T(reg) cells promote cancer progression. Immune adjuvants, including double-stranded (ds)RNAs, which signal via Toll-like receptor-3 (TLR3) and helicase (RIG-I/MDA5) pathways, all induce intratumoral production of CTL-attractants, but also Treg attractants and suppressive factors, raising the question of whether induction of these opposing groups of immune mediators can be separated. Here, we use human tumor explant cultures and cell culture models to show that the (ds) RNA Sendai Virus (SeV), poly-I:C, and rintatolimod (poly-I:C12U) all activate the TLR3 pathway involving TRAF3 and IRF3, and induce IFNα, ISG-60, and CXCL10 to promote CTL chemotaxis to ex vivo-treated tumors. However, in contrast with SeV and poly I:C, rintatolimod did not activate the MAVS/helicase pathway, thus avoiding NFκB- and TNFα-dependent induction of COX2, COX2/PGE2-dependent induction of IDO, IL10, CCL22, and CXCL12, and eliminating Treg attraction. Induction of CTL-attractants by either poly I:C or rintatolimod was further enhanced by exogenous IFNα (enhancer of TLR3 expression), whereas COX2 inhibition enhanced the response to poly-I:C only. Our data identify the helicase/NFκB/TNFα/COX2 axis as the key suppressive pathway of dsRNA signaling in human TME and suggest that selective targeting of TLR3 or elimination of NFκB/TNFα/COX2-driven suppression may allow for selective enhancement of type-1 immunity.Significance: This study characterizes two different poly-I:C-induced signaling pathways in their induction of immunostimulatory and suppressive factors and suggests improved ways to reprogram the TME to enhance the antitumor efficacy of immunotherapies. Cancer Res; 78(15); 4292-302. ©2018 AACR.

Benign Breast Diseases: Evaluation and Management.

Benign breast disease is a spectrum of common disorders. The majority of patients with a clinical breast lesion will have benign process. Management involves symptom control when present, pathologic-based and imaging-based evaluation to distinguish from a malignant process, and counseling for patients that have an increased breast cancer risk due to the benign disorder.

BAD-mediated apoptotic pathway is associated with human cancer development.

The malignant transformation of normal cells is caused in part by aberrant gene expression disrupting the regulation of cell proliferation, apoptosis, senescence and DNA repair. Evidence suggests that the Bcl-2 antagonist of cell death (BAD)-mediated apoptotic pathway influences cancer chemoresistance. In the present study, we explored the role of the BAD-mediated apoptotic pathway in the development and progression of cancer. Using principal component analysis to derive a numeric score representing pathway expression, we evaluated clinico-genomic datasets (n=427) from corresponding normal, pre-invasive and invasive cancers of different types, such as ovarian, endometrial, breast and colon cancers in order to determine the associations between the BAD-mediated apoptotic pathway and cancer development. Immunofluorescence was used to compare the expression levels of phosphorylated BAD [pBAD (serine-112, -136 and -155)] in immortalized normal and invasive ovarian, colon and breast cancer cells. The expression of the BAD-mediated apoptotic pathway phosphatase, PP2C, was evaluated by RT-qPCR in the normal and ovarian cancer tissue samples. The growth-promoting effects of pBAD protein levels in the immortalized normal and cancer cells were assessed using siRNA depletion experiments with MTS assays. The expression of the BAD-mediated apoptotic pathway was associated with the development and/or progression of ovarian (n=106, p<0.001), breast (n=185, p<0.0008; n=61, p=0.04), colon (n=22, p<0.001) and endometrial (n=33, p<0.001) cancers, as well as with ovarian endometriosis (n=20, p<0.001). Higher pBAD protein levels were observed in the cancer cells compared to the immortalized normal cells, whereas PP2C gene expression was lower in the cancer compared to the ovarian tumor tissue samples (n=76, p<0.001). The increased pBAD protein levels after the depletion of PP2C conferred a growth advantage to the immortalized normal and cancer cells. The BAD-mediated apoptotic pathway is thus associated with the development of human cancers likely influenced by the protein levels of pBAD.

Netrin and Frazzled regulate presynaptic gap junctions at a Drosophila giant synapse.

Netrin and its receptor, Frazzled, dictate the strength of synaptic connections in the giant fiber system (GFS) of Drosophila melanogaster by regulating gap junction localization in the presynaptic terminal. In Netrin mutant animals, the synaptic coupling between a giant interneuron and the "jump" motor neuron was weakened and dye coupling between these two neurons was severely compromised or absent. In cases in which Netrin mutants displayed apparently normal synaptic anatomy, half of the specimens exhibited physiologically defective synapses and dye coupling between the giant fiber (GF) and the motor neuron was reduced or eliminated, suggesting that gap junctions were disrupted in the Netrin mutants. When we examined the gap junctions with antibodies to Shaking-B (ShakB) Innexin, they were significantly decreased or absent in the presynaptic terminal of the mutant GF. Frazzled loss of function mutants exhibited similar defects in synaptic transmission, dye coupling, and gap junction localization. These data are the first to show that Netrin and Frazzled regulate the placement of gap junctions presynaptically at a synapse.

Stable radio-frequency transfer over optical fiber by phase-conjugate frequency mixing.

We demonstrate long-distance (≥100-km) synchronization of the phase of a radio-frequency reference over an optical-fiber network without needing to actively stabilize the optical path length. Frequency mixing is used to achieve passive phase-conjugate cancellation of fiber-length fluctuations, ensuring that the phase difference between the reference and synchronized oscillators is independent of the link length. The fractional radio-frequency-transfer stability through a 100-km "real-world" urban optical-fiber network is 6 × 10(-17) with an averaging time of 10(4) s. Our compensation technique is robust, providing long-term stability superior to that of a hydrogen maser. By combining our technique with the short-term stability provided by a remote, high-quality quartz oscillator, this system is potentially applicable to transcontinental optical-fiber time and frequency dissemination where the optical round-trip propagation time is significant.

Neuroendocrine carcinoma of the cervix during pregnancy: A case report.

► Neuroendocrine carcinoma of the cervix is a rare and aggressive malignancy. ► A multimodality approach must be individualized when diagnosed during pregnancy. ► We report the use of a therapeutic cervical cone and adjuvant chemotherapy.

Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy.

The greenhouse-gas molecules CO(2), CH(4), and H(2)O are detected in air within a few ms by a novel cavity-ringdown laser-absorption spectroscopy technique using a rapidly swept optical cavity and multi-wavelength coherent radiation from a set of pre-tuned near-infrared diode lasers. The performance of various types of tunable diode laser, on which this technique depends, is evaluated. Our instrument is both sensitive and compact, as needed for reliable environmental monitoring with high absolute accuracy to detect trace concentrations of greenhouse gases in outdoor air.

Isolation and structural modification of 7-deoxynarciclasine and 7-deoxy-trans-dihydronarciclasine.

As an extension of structure-activity relationship studies of pancratistatin (1), various techniques were first evaluated for separating the mixtures of 7-deoxynarciclasine (2b) and 7-deoxy-trans-dihydronarciclasine (3a) isolated from Hymenocallis littoralis. An efficient solution for that otherwise difficult separation then allowed the lactam carbonyl group of protected (4c and 5c) alcohols 2b and 3a to be reduced employing lithium aluminum hydride. Cleavage (TBAF followed by H2SO4) of the silyl ester/acetonide protected 6a gave amine 8. X-ray crystal structure determinations were employed to confirm the structures of 3,4-acetonide-5-aza-6-deoxynarciclasine (6b), 5-aza-6-deoxynarciclasine (8a), and 5-aza-6-deoxy-trans-dihydronarciclasine (9a, 9b). Against the murine P388 lymphocytic leukemia and a panel of human cancer cell lines, the parent natural products, 7-deoxynarciclasine (2b) and 7-deoxy-trans-dihydronarciclasine (3a), were found to generally be more cancer cell growth inhibitory (GI50 0.1 to <0.01 microg/mL) than the compounds with structural modifications such as amine 8 by a factor of 10 or more. The trans ring juncture of isocarbostyril 3a proved to be an important modification of narciclasine (2a) for improving cancer cell growth inhibition in this series.