Anti-Müllerian hormone-mediated preantral follicle atresia is a key determinant of antral follicle count in mice

STUDY QUESTION

Does anti-Müllerian hormone (AMH) induce preantral follicle atresia in mice?

SUMMARY ANSWER

The present findings suggest that AMH-mediated follicle atresia only occurs in early follicles before they become sensitive to FSH.

WHAT IS KNOWN ALREADY

Most prior studies have investigated the ability of AMH to inhibit primordial follicle activation. Our previous study showed that AMH-overexpressing mice had fewer preantral follicles than expected after accounting for primordial follicle inhibition but the reason for this was not determined.

STUDY DESIGN, SIZE, DURATION

Cross-sectional-control versus transgenic/knockout mouse studies were carried out.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Studies were conducted on female wild-type (Amh+/+), AMH-knockout (Amh-/-) and AMH overexpressing (Thy1.2-AMHTg/0) mice on a C57Bl/6J background (age: 42-120 days). The follicle counts were conducted for primordial, transitioning, primary, secondary and antral follicles in Amh-/- and Amh+/+ mice. After confirming that follicle development speeds were identical (proliferating cell nuclear antigen immunohistochemistry), the ratio of follicles surviving beyond each stage of folliculogenesis was determined in both genotypes. Evidence for increased rates of preantral follicle atresia was assessed by active caspase-3 immunohistochemistry in wild-type and Thy1.2-AMHTg/0 mice.

MAIN RESULTS AND THE ROLE OF CHANCE

Amh -/- mice at 100-120 days of age had lower primordial follicle counts but higher primordial follicle activation rates compared to Amh+/+ mice. These counteracting effects led to equivalent numbers of primordial follicles transitioning to the primary stage in Amh+/+ and Amh-/- mice. Despite this, Amh+/+ mice had fewer primary, secondary, small antral and medium antral follicles than Amh-/- mice indicating differing rates of developing follicle atresia between genotypes. Cleaved caspase-3 immunohistochemistry in Thy1.2-AMHTg/0 ovaries revealed high rates of granulosa cell and oocyte apoptosis in late primary/early secondary follicles of Thy1.2-AMHTg/0 mice.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The findings were shown only in one species and additional research will be required to determine generalizability to other species.

WIDER IMPLICATIONS OF THE FINDINGS

This study is consistent with prior studies showing that Amh-/- mice have increased primordial follicle activation but these new findings demonstrate that AMH-mediated preantral follicle atresia is a predominant cause of the increased small antral follicle counts in Amh-/- mice. This suggests that the role of AMH is not to conserve the ovarian reserve to prolong fertility, but instead to prevent the antral follicle pool from becoming too large. While this study may demonstrate a new function for AMH, the biological purpose of this function requires further investigation, particularly in mono-ovulatory species.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Health Research Council of New Zealand and the University of Otago. No competing interests to declare.

Discovery of amivantamab (JNJ-61186372), a bispecific antibody targeting EGFR and MET

A bispecific antibody (BsAb) targeting the epidermal growth factor receptor (EGFR) and mesenchymal-epithelial transition factor (MET) pathways represents a novel approach to overcome resistance to targeted therapies in patients with non-small cell lung cancer. In this study, we sequentially screened a panel of BsAbs in a combinatorial approach to select the optimal bispecific molecule. The BsAbs were derived from different EGFR and MET parental monoclonal antibodies. Initially, molecules were screened for EGFR and MET binding on tumor cell lines and lack of agonistic activity toward MET. Hits were identified and further screened based on their potential to induce untoward cell proliferation and cross-phosphorylation of EGFR by MET via receptor colocalization in the absence of ligand. After the final step, we selected the EGFR and MET arms for the lead BsAb and added low fucose Fc engineering to generate amivantamab (JNJ-61186372). The crystal structure of the anti-MET Fab of amivantamab bound to MET was solved, and the interaction between the two molecules in atomic details was elucidated. Amivantamab antagonized the hepatocyte growth factor (HGF)-induced signaling by binding to MET Sema domain and thereby blocking HGF β-chain-Sema engagement. The amivantamab EGFR epitope was mapped to EGFR domain III and residues K443, K465, I467, and S468. Furthermore, amivantamab showed superior antitumor activity over small molecule EGFR and MET inhibitors in the HCC827-HGF in vivo model. Based on its unique mode of action, amivantamab may provide benefit to patients with malignancies associated with aberrant EGFR and MET signaling.

Rapid COVID-19 Prognostic Blood Test for Disease Severity Using Epigenetic Immune System Biomarkers

OBJECTIVE

To develop a novel whole-blood epigenetic biomarker of immune system status, or EpiMarker, that would indicate whether a person with a recent COVID-19 diagnosis is at risk for severe symptoms including Acute Respiratory Distress Syndrome.

METHODS

Using a novel methyl-sensitive restriction endonuclease approach to measure site-specific DNA methylation profiles, immune system phentoype EpiMarkers are identified using a machine-learning computational bioinformatics platform. The result is a diagnostic network of 20 to 40 immuno DNA methylation sites having the greatest predictive power for identifying patients whose COVID-19 disease will likely progress to ARDS requiring ICU/intubation care.

RESULTS

Immune system status in peripheral whole blood provides a sensitive and responsive sentinel signal reflecting how different functional pathways are currently being regulated in a subject. Deciphering this signal status of how immune cells are set to respond provides deep functional information regarding patient health and potential disease phenotypes resulting from a cytokine storm characteristic of a hyper immune inflammatory response to COVID-19 infection.

CONCLUSIONS

The ability to identify future potential changes in patient health using this novel EpiMarker technology opens new avenues for defending populations from severe disease risks of Acute Respiratory Distress Syndrome.

POLICY IMPLICATIONS

A successful EpiMarker Assay for COVID-19 disease severity risk would allow for two important applications: (1) patients could be triaged early in the course of infection to allow for critical decisions for allocating resources, both in terms of hospital infrastructure (ICU beds, ventilators) and therapeutic drug treatments; and (2) pre-infection, individuals could be screened to identify personnel at low-risk for mission critical assignments (first responders, doctors, nurses, military personnel, etc.) during future pandemics and ongoing battles with viral pathogens like influenza.

Reframing autism as a behavioral syndrome and not a specific mental disorder: Implications of genetic and phenotypic heterogeneity

Clinical and molecular genetics have advanced current knowledge on genetic disorders associated with autism. A review of diverse genetic disorders associated with autism is presented and for the first time discussed extensively with regard to possible common underlying mechanisms leading to a similar cognitive-behavioral phenotype of autism. The possible role of interactions between genetic and environmental factors, including epigenetic mechanisms, is in particular examined. Finally, the pertinence of distinguishing non-syndromic autism (isolated autism) from syndromic autism (autism associated with genetic disorders) will be reconsidered. Given the high genetic and etiological heterogeneity of autism, autism can be viewed as a behavioral syndrome related to known genetic disorders (syndromic autism) or currently unknown disorders (apparent non-syndromic autism), rather than a specific categorical mental disorder. It highlights the need to study autism phenotype and developmental trajectory through a multidimensional, non-categorical approach with multivariate analyses within autism spectrum disorder but also across mental disorders, and to conduct systematically clinical genetic examination searching for genetic disorders in all individuals (children but also adults) with autism.

A Novel Bispecific Antibody Targeting EGFR and cMet Is Effective against EGFR Inhibitor-Resistant Lung Tumors

Non-small cell lung cancers (NSCLC) with activating EGFR mutations become resistant to tyrosine kinase inhibitors (TKI), often through second-site mutations in EGFR (T790M) and/or activation of the cMet pathway. We engineered a bispecific EGFR-cMet antibody (JNJ-61186372) with multiple mechanisms of action to inhibit primary/secondary EGFR mutations and the cMet pathway. JNJ-61186372 blocked ligand-induced phosphorylation of EGFR and cMet and inhibited phospho-ERK and phospho-AKT more potently than the combination of single receptor-binding antibodies. In NSCLC tumor models driven by EGFR and/or cMet, JNJ-61186372 treatment resulted in tumor regression through inhibition of signaling/receptor downmodulation and Fc-driven effector interactions. Complete and durable regression of human lung xenograft tumors was observed with the combination of JNJ-61186372 and a third-generation EGFR TKI. Interestingly, treatment of cynomolgus monkeys with JNJ-61186372 resulted in no major toxicities, including absence of skin rash observed with other EGFR-directed agents. These results highlight the differentiated potential of JNJ-61186372 to inhibit the spectrum of mutations driving EGFR TKI resistance in NSCLC. Cancer Res; 76(13); 3942-53. ©2016 AACR.

Leptin Responsive and GABAergic Projections to the Rostral Preoptic Area in Mice

The adipocyte-derived hormone leptin plays a critical role in the control of reproduction via signalling in hypothalamic neurones. The drivers of the hypothalamic-pituitary-gonadal axis, the gonadotrophin-releasing hormone (GnRH) neurones, do not have the receptors for leptin. Therefore, intermediate leptin responsive neurones must provide leptin-to-GnRH signalling. We investigated the populations of leptin responsive neurones that provide input to the rostral preoptic area (rPOA) where GnRH cell bodies reside. Fluorescent retrograde tracer beads (RetroBeads; Lumafluor Inc., Naples, FL, USA) were injected into the rPOA of transgenic leptin receptor enhanced green fluorescent protein (Lepr-eGFP) reporter mice. Uptake of the RetroBeads by Lepr-eGFP neurones was assessed throughout the hypothalamus. RetroBead uptake was most evident in the medial arcuate nucleus (ARC), the dorsomedial nucleus (DMN) and the ventral premammillary nucleus (PMV) of the hypothalamus. The uptake of RetroBeads specifically by Lepr-eGFP neurones was highest in the medial ARC (18% of tracer-labelled neurones Lepr-eGFP-positive). Because neurones that are both leptin responsive and GABAergic play a critical role in the regulation of fertility by leptin, we next focussed on the location of these populations. To address whether GABAergic neurones in leptin-responsive hypothalamic regions project to the rPOA, the experiment was repeated in GABA neurone reporter mice (Vgat-tdTomato). Between 10% and 45% of RetroBead-labelled neurones in the ARC were GABAergic, whereas uptake of tracer by GABAergic neurones in the DMN and PMV was very low (< 5%). These results show that both leptin responsive and GABAergic neurones from the ARC project to the region of the GnRH cell bodies. Our findings suggest that LEPR-expressing GABA neurones from the ARC may be mediators of leptin-to-GnRH signalling.

Insulin Does Not Target CamkIIα Neurones to Critically Regulate the Neuroendocrine Reproductive Axis in Mice

Insulin signalling in the brain plays an important role in the central regulation of energy homeostasis and fertility, such that mice exhibiting widespread deletion of insulin receptors (InsR) throughout the brain and peripheral nervous system display diet sensitive obesity and hypothalamic hypogonadism. However, the specific cell types mediating the central effects of insulin on fertility remain largely unidentified. To date, the targeted deletion of InsR from individual neuronal populations implicated in the metabolic control of fertility has failed to recapitulate the hypogonadic and subfertile phenotype observed in brain-specific InsR knockout mice. Because insulin and leptin share similar roles as centrally-acting metabolic regulators of fertility, we used the Cre-loxP system to generate mice with a selective inactivation of the Insr gene from the same widespread neuronal population previously shown to mediate the central effects of leptin on fertility by crossing Insr-flox mice with calcium/calmodulin-dependent protein kinase type IIα (CamkIIα)-Cre mice. Multiple reproductive and metabolic parameters were then compared between male and female Insr-flox/Cre-positive (CamK-IRKO) and Insr-flox/Cre-negative control mice. Consistent with brain-specific InsR knockout mice, CamK-IRKO mice exhibited a mild but significant obesogenic phenotype. Unexpectedly, CamK-IRKO mice exhibited normal reproductive maturation and function compared to controls. No differences in the age of puberty onset, oestrous cyclicity or fecundity were observed between CamK-IRKO and control mice. We conclude that the central effects of insulin on the neuroendocrine reproductive axis are not critically mediated via the same neuronal populations targeted by leptin.

A population-based study of ethnicity and breast cancer stage at diagnosis in Ontario

BACKGROUND

Breast cancer stage at diagnosis is an important predictor of survival. Our goal was to compare breast cancer stage at diagnosis (by American Joint Committee on Cancer criteria) in Chinese and South Asian women with stage at diagnosis in the remaining general population in Ontario.

METHODS

We used the Ontario population-based cancer registry to identify all women diagnosed with breast cancer during 2005-2010, and we applied a validated surname algorithm to identify South Asian and Chinese women. We used logistic regression to compare, for Chinese or South Asian women and for the remaining general population, the frequency of diagnoses at stage ii compared with stage i and stages ii-iv compared with stage i.

RESULTS

The registry search identified 1304 Chinese women, 705 South Asian women, and 39,287 women in the remaining general population. The Chinese and South Asian populations were younger than the remaining population (mean: 54, 57, and 61 years respectively). Adjusted for age, South Asian women were more often diagnosed with breast cancer at stage ii than at stage i [odds ratio (or): 1.28; 95% confidence interval (ci): 1.08 to 1.51] or at stages ii-iv than at stage i (or: 1.27; 95% ci: 1.08 to 1.48); Chinese women were less likely to be diagnosed at stage ii than at stage i (or: 0.82; 95% ci: 0.72 to 0.92) or at stages ii-iv than at stage i (or: 0.73; 95% ci: 0.65 to 0.82).

CONCLUSIONS

Breast cancers were diagnosed at a later stage in South Asian women and at an earlier stage in Chinese women than in the remaining population. A more detailed analysis of ethnocultural factors influencing breast screening uptake, retention, and care-seeking behavior might be needed to help inform and evaluate tailored health promotion activities.

Evidence that insulin signalling in gonadotrophin-releasing hormone and kisspeptin neurones does not play an essential role in metabolic regulation of fertility in mice

Insulin in the brain plays an important role in regulating reproductive function, as demonstrated via conditional brain-specific insulin receptor (Insr) deletion (knockout). However, the specific neuronal target cells mediating the central effects of insulin on the reproductive axis remain unidentified. We first investigated whether insulin can act via direct effects on gonadotrophin-releasing hormone (GnRH) neurones. After clearly detecting Insr mRNA in an immunopurified GnRH cell fraction, we confirmed the presence of insulin receptor protein (InsR) in approximately 82% of GnRH neurones using dual-label immunohistochemistry. However, we did not observe any insulin-induced phospho-Akt (pAkt) or phospho-extracellular-signal-regulated kinase 1/2 in GnRH neurones, and therefore we investigated whether insulin signals via kisspeptin neurones to modulate GnRH release. Using dual-label immunohistochemistry, InsRs were detected only in approximately 5% of kisspeptin-immunoreactive cells. Insulin-induced pAkt was not observed in any kisspeptin-immunoreactive cells in either the rostral periventricular region of the third ventricle or arcuate nucleus in response to 200 mU of insulin treatment, although a more pharmacological dose (10 U) induced pronounced (> 20%) pAkt-kisspeptin coexpression in both regions. To confirm that insulin signalling via kisspeptin neurones does not critically modulate reproductive function, we generated kisspeptin-specific InsR knockout (KIRKO) mice and assessed multiple reproductive and metabolic parameters. No significant differences in puberty onset, oestrous cyclicity or reproductive competency were observed in the female or male KIRKO mice compared to their control littermates. However, significantly decreased fasting insulin (P < 0.05) and a nonsignificant trend towards reduced body weight were observed in male KIRKO mice. Thus, InsR signalling in kisspeptin cells is not critical for puberty onset or reproductive competency, although it may have a small metabolic effect in males.

Modelling preventive effectiveness to estimate the equity tipping point: at what coverage can individual preventive interventions reduce socioeconomic disparities in diabetes risk?

INTRODUCTION

Most individual preventive therapies potentially narrow or widen health disparities depending on the difference in community effectiveness across socioeconomic position (SEP). The equity tipping point (defined as the point at which health disparities become larger) can be calculated by varying components of community effectiveness such as baseline risk of disease, intervention coverage and/or intervention efficacy across SEP.

METHODS

We used a simple modelling approach to estimate the community effectiveness of diabetes prevention across SEP in Canada under different scenarios of intervention coverage.

RESULTS

Five-year baseline diabetes risk differed between the lowest and highest income groups by 1.76%. Assuming complete coverage across all income groups, the difference was reduced to 0.90% (144 000 cases prevented) with lifestyle interventions and 1.24% (88 100 cases prevented) with pharmacotherapy. The equity tipping point was estimated to be a coverage difference of 30% for preventive interventions (100% and 70% coverage among the highest and lowest income earners, respectively).

CONCLUSION

Disparities in diabetes risk could be measurably reduced if existing interventions were equally adopted across SEP. However, disparities in coverage could lead to increased inequity in risk. Simple modelling approaches can be used to examine the community effectiveness of individual preventive interventions and their potential to reduce (or increase) disparities. The equity tipping point can be used as a critical threshold for disparities analyses.

Evidence that hypothalamic RFamide related peptide-3 neurones are not leptin-responsive in mice and rats

Leptin, a permissive hormonal regulator of fertility, provides information about the body's energy reserves to the hypothalamic gonadotrophin-releasing hormone (GnRH) neuronal system that drives reproduction. Leptin does not directly act on GnRH neurones, and the neuronal pathways that it uses remain unclear. RFamide-related peptide-3 (RFRP-3) neurones project to GnRH neurones and primarily inhibit their activity. We tested whether leptin could act via RFRP-3 neurones to potentially modulate GnRH activity. First, the effects of leptin deficiency or high-fat diet-induced obesity on RFRP-3 cell numbers and gene expression were assessed in male and female mice. There was no significant difference in Rfrp mRNA levels or RFRP-3-immunoreactive cell counts in wild-type versus leptin-deficient ob/ob animals, or in low-fat versus high-fat diet fed wild-type mice. Second, the presence of leptin-induced signalling in RFRP-3 neurones was examined in male and female wild-type mice and rats. Dual label immunohistochemistry revealed leptin-induced phosphorylated signal transducer and activator of transcription-3 in close proximity to RFRP-3 neurones, although there was very little (2-13%) colocalisation and no significant differences between vehicle and leptin-treated animals. Furthermore, we were unable to detect leptin receptor mRNA in a semi-purified RFRP-3 cell preparation. Because GABA neurones form critical leptin-responsive GnRH inputs, we also determined whether RFRP-3 and GABA cells were colocalised. No such colocalisation was detected. These results support the concept that leptin has little or no effects on RFRP-3 neurones, and that these neurones are unlikely to be an important neuronal pathway for the metabolic regulation of fertility by leptin.

Maternal and newborn outcomes among women with schizophrenia: a retrospective population-based cohort study

OBJECTIVE

More women with schizophrenia are becoming pregnant, such that contemporary data are needed about maternal and newborn outcomes in this potentially vulnerable group. We aimed to quantify maternal and newborn health outcomes among women with schizophrenia.

DESIGN

Retrospective cohort study.

SETTING

Population based in Ontario, Canada, from 2002 to 2011.

POPULATION

Ontario women aged 15-49 years who gave birth to a liveborn or stillborn singleton infant.

METHODS

Women with schizophrenia (n = 1391) were identified based on either an inpatient diagnosis or two or more outpatient physician service claims for schizophrenia within 5 years prior to conception. The reference group comprised 432 358 women without diagnosed mental illness within the 5 years preceding conception in the index pregnancy.

MAIN OUTCOME MEASURES

The primary maternal outcomes were gestational diabetes mellitus, gestational hypertension, pre-eclampsia/eclampsia, and venous thromboembolism. The primary neonatal outcomes were preterm birth, and small and large birthweight for gestational age (SGA and LGA). Secondary outcomes included additional key perinatal health indicators.

RESULTS

Schizophrenia was associated with a higher risk of pre-eclampsia (adjusted odds ratio, aOR 1.84; 95% confidence interval, 95% CI 1.28-2.66), venous thromboembolism (aOR 1.72, 95% CI 1.04-2.85), preterm birth (aOR 1.75, 95% CI 1.46-2.08), SGA (aOR 1.49, 95% CI 1.19-1.86), and LGA (aOR 1.53, 95% CI 1.17-1.99). Women with schizophrenia also required more intensive hospital resources, including operative delivery and admission to a maternal intensive care unit, paralleled by higher neonatal morbidity.

CONCLUSIONS

Women with schizophrenia are at higher risk of multiple adverse pregnancy outcomes, paralleled by higher neonatal morbidity. Attention should focus on interventions to reduce the identified health disparities.

Kisspeptin neurones do not directly signal to RFRP-3 neurones but RFRP-3 may directly modulate a subset of hypothalamic kisspeptin cells in mice

The neuropeptides kisspeptin (encoded by Kiss1) and RFamide-related peptide-3 (also known as GnIH; encoded by Rfrp) are potent stimulators and inhibitors, respectively, of reproduction. Whether kisspeptin or RFRP-3 might act directly on each other's neuronal populations to indirectly modulate reproductive status is unknown. To examine possible interconnectivity of the kisspeptin and RFRP-3 systems, we performed double-label in situ hybridisation (ISH) for the RFRP-3 receptors, Gpr147 and Gpr74, in hypothalamic Kiss1 neurones of adult male and female mice, as well as double-label ISH for the kisspeptin receptor, Kiss1r, in Rfrp-expressing neurones of the hypothalamic dorsal-medial nucleus (DMN). Only a very small proportion (5-10%) of Kiss1 neurones of the anteroventral periventricular region expressed Gpr147 or Gpr74 in either sex, whereas higher co-expression (approximately 25%) existed in Kiss1 neurones in the arcuate nucleus. Thus, RFRP-3 could signal to a small, primarily arcuate, subset of Kiss1 neurones, a conclusion supported by the finding of approximately 35% of arcuate kisspeptin cells receiving RFRP-3-immunoreactive fibre contacts. By contrast to the former situation, no Rfrp neurones co-expressed Kiss1r in either sex, and Tacr3, the receptor for neurokinin B (NKB; a neuropeptide co-expressed with arcuate kisspeptin neurones) was found in <10% of Rfrp neurones. Moreover, kisspeptin-immunoreactive fibres did not readily appose RFRP-3 cells in either sex, further excluding the likelihood that kisspeptin neurones directly communicate to RFRP-3 neurones. Lastly, despite abundant NKB in the DMN region where RFRP-3 soma reside, NKB was not co-expressed in the majority of Rfrp neurones. Our results suggest that RFRP-3 may modulate a small proportion of kisspeptin-producing neurones in mice, particularly in the arcuate nucleus, whereas kisspeptin neurones are unlikely to have any direct reciprocal actions on RFRP-3 neurones.

Parental broader autism subphenotypes in ASD affected families: relationship to gender, child's symptoms, SSRI treatment, and platelet serotonin

Relationships between parental broader autism phenotype (BAP) scores, gender, selective serotonin reuptake inhibitor (SSRI) treatment, serotonin (5HT) levels, and the child's symptoms were investigated in a family study of autism spectrum disorder (ASD). The Broader Autism Phenotype Questionnaire (BAPQ) was used to measure the BAP of 275 parents. Fathers not taking SSRIs (F-SSRI; n = 115) scored significantly higher on BAP Total and Aloof subscales compared to mothers not receiving treatment (M-SSRI; n = 136.) However, mothers taking SSRIs (M + SSRI; n = 19) scored higher than those not taking medication on BAP Total and Rigid subscales, and they were more likely to be BAPQ Total, Aloof, and Rigid positive. Significant correlations were noted between proband autism symptoms and parental BAPQ scores such that Total, Aloof, and Rigid subscale scores of F-SSRI correlated with proband restricted repetitive behavior (RRB) measures on the ADOS, CRI, and RBS-R. However, only the Aloof subscale score of M + SSRI correlated with proband RRB on the ADOS. The correlation between the BAPQ scores of mothers taking SSRIs and child scores, as well as the increase in BAPQ scores of this group of mothers, requires careful interpretation and further study because correlations would not withstand multiple corrections. As expected by previous research, significant parent-child correlations were observed for 5HT levels. However, 5HT levels were not correlated with behavioral measures. Study results suggest that the expression of the BAP varies not only across parental gender, but also across individuals using psychotropic medication and those who do not.

Endothelial protein C receptor function in murine and human breast cancer development

Several markers identify cancer stem cell-like populations, but little is known about the functional roles of stem cell surface receptors in tumor progression. Here, we show that the endothelial protein C receptor (EPCR), a stem cell marker in hematopoietic, neuronal and epithelial cells, is crucial for breast cancer growth in the orthotopic microenvironment of the mammary gland. Mice with a hypomorphic allele of EPCR show reduced tumor growth in the PyMT-model of spontaneous breast cancer development and deletion of EPCR in established PyMT tumor cells significantly attenuates transplanted tumor take and growth. We find expansion of EPCR⁺ cancer stem cell-like populations in aggressive, mammary fat pad-enhanced human triple negative breast cancer cells. In this model, EPCR-expressing cells have markedly increased mammosphere- and tumor-cell initiating activity compared to another stable progenitor-like subpopulation present at comparable frequency. We show that receptor blocking antibodies to EPCR specifically attenuate in vivo tumor growth initiated by either EPCR⁺ cells or the heterogenous mixture of EPCR⁺ and EPCR^- cells. Furthermore, we have identified tumor associated macrophages as a major source for recognized ligands of EPCR, suggesting a novel mechanism by which cancer stem cell-like populations are regulated by innate immune cells in the tumor microenvironment.

Incidence of diabetes among postmenopausal breast cancer survivors

AIMS/HYPOTHESIS

Evidence is emerging of an association between breast cancer and diabetes; however, it is uncertain whether diabetes incidence is increased in postmenopausal breast cancer survivors compared with women without breast cancer. The objective of this study was to determine whether postmenopausal women who develop breast cancer have a higher incidence of diabetes than those who do not develop breast cancer.

METHODS

We used population-based data from Ontario, Canada to compare the incidence of diabetes among women with breast cancer, aged 55 years or older, from 1996 to 2008, with that of age-matched women without breast cancer. We used Cox proportional hazard models to estimate the effect of breast cancer on the cause-specific hazard of developing diabetes overall and in the subgroup of women who received adjuvant chemotherapy.

RESULTS

Of 24,976 breast cancer survivors and 124,880 controls, 9.7% developed diabetes over a mean follow-up of 5.8 years. The risk of diabetes among breast cancer survivors compared with women without breast cancer began to increase 2 years after diagnosis (HR 1.07 [95% CI, 1.02, 1.12]), and rose to an HR of 1.21 (95% CI, 1.09, 1.35) after 10 years. Among those who received adjuvant chemotherapy (n = 4,404), risk was highest in the first 2 years after diagnosis (HR 1.24 [95% CI 1.12, 1.38]) and then declined.

CONCLUSIONS/INTERPRETATION

We found a modest increase in the incidence of diabetes among postmenopausal breast cancer survivors that varied over time. In most women the risk began to increase 2 years after cancer diagnosis but the highest risk was in the first 2 years in those who received adjuvant therapy. Our study suggests that greater diabetes screening and prevention strategies among breast cancer survivors may be warranted.

Using the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) to predict 1-year mortality in population-based cohorts of patients with diabetes in Ontario, Canada

AIMS

There are limited validated methods to ascertain comorbidities for risk adjustment in ambulatory populations of patients with diabetes using administrative health-care databases. The objective was to examine the ability of the Johns Hopkins' Aggregated Diagnosis Groups to predict mortality in population-based ambulatory samples of both incident and prevalent subjects with diabetes.

METHODS

Retrospective cohorts constructed using population-based administrative data. The incident cohort consisted of all 346,297 subjects diagnosed with diabetes between 1 April 2004 and 31 March 2008. The prevalent cohort consisted of all 879,849 subjects with pre-existing diabetes on 1 January, 2007. The outcome was death within 1 year of the subject's index date.

RESULTS

A logistic regression model consisting of age, sex and indicator variables for 22 of the 32 Johns Hopkins' Aggregated Diagnosis Group categories had excellent discrimination for predicting mortality in incident diabetes patients: the c-statistic was 0.87 in an independent validation sample. A similar model had excellent discrimination for predicting mortality in prevalent diabetes patients: the c-statistic was 0.84 in an independent validation sample. Both models demonstrated very good calibration, denoting good agreement between observed and predicted mortality across the range of predicted mortality in which the large majority of subjects lay. For comparative purposes, regression models incorporating the Charlson comorbidity index, age and sex, age and sex, and age alone had poorer discrimination than the model that incorporated the Johns Hopkins' Aggregated Diagnosis Groups.

CONCLUSIONS

Logistical regression models using age, sex and the John Hopkins' Aggregated Diagnosis Groups were able to accurately predict 1-year mortality in population-based samples of patients with diabetes.

Altered response to neuroendocrine challenge linked to indices of the metabolic syndrome in healthy adults

Metabolic syndrome (MetS) is characterized by central obesity, hypertension, insulin resistance, and hypercholesterolemia. Hypothalamic-pituitary-adrenal (HPA) axis activity is frequently abnormal in MetS, and excessive cortisol exposure may be implicated in metabolic derangements. We investigated the hypothesis that cortisol and adrenocorticotropic hormone (ACTH) responses to a standardized neuroendocrine challenge test would be associated with indices of MetS in a community sample of healthy adults. Healthy adults, 125 men and 170 women, without significant medical problems or chronic medications were recruited from the community. Participants completed the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, and anthropometric measurements, blood pressure, glycosylated hemoglobin (HbA1c), and cholesterol were measured. Participants reported on their history of early life stress and recent stress, as well as mood and anxiety symptoms. Cortisol and ACTH responses to the Dex/CRH test were negatively associated with measures of central adiposity (p<0.001) and blood pressure (p<0.01), and positively associated with HDL cholesterol (p<0.01). These findings remained significant after controlling for body mass index (BMI). Measures of stress and anxiety and depressive symptoms were negatively correlated with cortisol and ACTH responses in the Dex/CRH test but were not related to MetS indices. That altered HPA axis function is linked to MetS components even in a healthy community sample suggests that these processes may be involved in the pathogenesis of MetS. Identification of premorbid risk processes might allow for detection and intervention prior to the development of disease.

Brain growth trajectories in mouse strains with central and peripheral serotonin differences: relevance to autism models

The genetic heterogeneity of autism spectrum disorders (ASDs) suggests that their underlying neurobiology involves dysfunction at the neural network level. Understanding these neural networks will require a major collaborative effort and will depend on validated and widely accepted animal models. Many mouse models have been proposed in autism research, but the assessment of their validity often has been limited to measuring social interactions. However, two other well-replicated findings have been reported in ASDs: transient brain overgrowth in early postnatal life and elevated 5-HT (serotonin) levels in blood platelets (platelet hyperserotonemia). We examined two inbred mouse strains (C57BL/6 and BALB/c) with respect to these phenomena. The BALB/c strain is less social and exhibits some other autistic-like behaviors. In addition, it has a lower 5-HT synthesis rate in the central nervous system due to a single-nucleotide polymorphism in the tryptophan hydroxylase 2 (Tph2) gene. The postnatal growth of brain mass was analyzed with mixed-effects models that included litter effects. The volume of the hippocampal complex and the thickness of the somatosensory cortex were measured in 3D-brain reconstructions from serial sections. The postnatal whole-blood 5-HT levels were assessed with high-performance liquid chromatography. With respect to the BALB/c strain, the C57BL/6 strain showed transient brain overgrowth and persistent blood hyperserotonemia. The hippocampal volume was permanently enlarged in the C57BL/6 strain, with no change in the adult brain mass. These results indicate that, in mice, autistic-like shifts in the brain and periphery may be associated with less autistic-like behaviors. Importantly, they suggest that consistency among behavioral, anatomical, and physiological measures may expedite the validation of new and previously proposed mouse models of autism, and that the construct validity of models should be demonstrated when these measures are inconsistent.

Both p110alpha and p110beta isoforms of phosphatidylinositol 3-OH-kinase are required for insulin signalling in the hypothalamus

Both insulin and leptin action in the brain are considered to involve activation of phosphoinositide 3-kinase (PI3K), although the roles of different PI3K isoforms in insulin signalling in the hypothalamus are unknown. In the present study, we characterised the roles of these isoforms in hypothalamic insulin and leptin signalling and investigated the cross-talk of both hormones. To evaluate PI3K levels in the hypothalamus, PI3K was immunoprecipitated using an antibody directed against the p85 subunit, and then total PI3K activity was measured in the presence of novel isoform-selective pharmacological inhibitors of each isoform of PI3K. Subsequently, these inhibitors were administered into the lateral ventricle of male Sprague-Dawley rats, followed by vehicle, insulin, leptin or both hormones 45 min later. PI3K activity was determined by immunohistochemical detection of phosphorylated AKT (S473). In a separate study, the effects of the inhibitors on the anorexigenic action of insulin and leptin were determined. Hypothalamic insulin signalling was specifically mediated by the combined actions of the class Ia isoforms p110alpha and p110beta. Total hypothalamic PI3K activity was inhibited 65% by a p110alpha inhibitor, and 35% by a p110beta inhibitor, with a combination of inhibitors being equally effective as the broad-spectrum PI3K inhibitor wortmannin. Individual i.c.v. administration of p110alpha and p110beta inhibitors partly prevented insulin-induced phosphorylated AKT (S473) in the arcuate nucleus, whereas simultaneous application completely blocked insulin action. Unlike insulin, leptin did not induce phosphorylated AKT in the hypothalamus, as detected by immunohistochemistry, and the anorectic effects of leptin were not affected by pre-treatment with a combination of p110alpha and p110beta inhibitors. The enhanced anorectic effect of a combined i.c.v. application of both insulin and leptin could be prevented by pre-treatment with the combination of p110alpha and p110beta inhibitors. The data suggest that p110alpha and p110beta isoforms of PI3K are necessary to mediate insulin action in the hypothalamus. The role of PI3K in leptin action is less clear, but it may be involved by means of an insulin-dependent sensitisation of leptin action.

Developmental and steroidogenic effects on the gene expression of RFamide related peptides and their receptor in the rat brain and pituitary gland

RFamide related peptides (RFRPs) have been extensively implicated in the neuroendocrine control of reproduction. While steroid hormones strongly regulate the closely-related kisspeptin gene and protein expression, the regulation of RFRPs or their receptor by steroid hormones is almost unknown. The present study aimed to quantify relative levels of RFRP and Kiss1 gene expression and their G protein-coupled receptors (GPR147 and GPR54, respectively) in various brain areas and the pituitary gland, and to determine the effects of differing levels of oestradiol and pubertal development on levels of these gene products. In Experiment 1, the treatment groups examined were: dioestrus, ovariectomised and ovariectomised with replacement oestradiol to induce a preovulatory-like luteinising hormone surge. Micropunched brain regions and whole pituitary glands were processed for measurement of RFRP, Kiss1, GPR147 and GPR54 mRNA by quantitative reverse transcriptase-polymerase chain reaction. As expected, Kiss1 gene expression was low in the rostral periventricular area of the third ventricle of ovariectomised animals, whereas levels were highest in the arcuate nucleus in this situation. No such oestrogenic effects were observed for RFRP gene expression. GPR147 gene expression was highest in the rostral periventricular region of the third ventricle. The levels of GPR147 and GPR54 mRNA were markedly lower in the pituitary gland than in the hypothalamic regions, and RFRP and Kiss1 mRNA were virtually undetectable in the pituitary gland. These data imply that the actions of RFamides are likely to be predominantly central in nature. In Experiment 2, hypothalamic RFRP and GPR147 mRNA levels were measured in male and female rats aged 2, 4, 6 and 8 weeks. In females, RFRP gene expression increased with developmental age, peaking around the time of puberty, whereas in males gene expression increased between 2 and 4 weeks of age. These results suggest a role in the regulation of adult reproduction rather that prepubertal infertility.

Characterization of cerebrospinal fluid monoamine metabolites in peripubertal chimpanzees (Pan troglodytes)

BACKGROUND

Assessment of cerebrospinal (CSF) monoamine metabolites 5-hydroxyindoeacetic acid (5-HIAA) and homovanillic acid (HVA), and the serotonin precursor tryptophan (TRP), in chimpanzees may help in understanding the neurobiology underlying aggressive, impulsive behavior in humans and non-human primates.

METHODS

Two CSF samples were obtained from 11 peripubertal chimpanzees 8 months apart and were assayed for monoamine metabolite and TRP concentrations.

RESULTS

Substantial inter-individual stability was observed for 5-HIAA (n = 11; r = 0.83, P < 0.001) and HVA (r = 0.91, P < 0.001). Females had significantly higher concentrations of 5-HIAA compared to males (F(1,8) = 7.31; P < 0.05). Levels of 5-HIAA (r = -0.62, P < 0.05), HVA (r = -0.86, P < 0.001) and TRP levels (r = -0.67; P < 0.05) decreased with age.

CONCLUSION

Close parallels were observed between chimpanzees and humans with respect to absolute levels, sex effects, ontogeny, and 5-HIAA-HVA correlations, supporting the potential utility of the measures in understanding relationships between monoamine functioning and behavior in chimpanzees and humans.

Tissue factor regulation by epidermal growth factor receptor and epithelial-to-mesenchymal transitions: effect on tumor initiation and angiogenesis

ErbB oncogenes drive the progression of several human cancers. Our study shows that in human carcinoma (A431) and glioma (U373) cells, the oncogenic forms of epidermal growth factor receptor (EGFR; including EGFRvIII) trigger the up-regulation of tissue factor (TF), the transmembrane protein responsible for initiating blood coagulation and signaling through interaction with coagulation factor VIIa. We show that A431 cancer cells in culture exhibit a uniform TF expression profile; however, these same cells in vivo exhibit a heterogeneous TF expression and show signs of E-cadherin inactivation, which is coupled with multilineage (epithelial and mesenchymal) differentiation. Blockade of E-cadherin in vitro, leads to the acquisition of spindle morphology and de novo expression of vimentin, features consistent with epithelial-to-mesenchymal transition. These changes were associated with an increase in EGFR-dependent TF expression, and with enhanced stimulation of vascular endothelial growth factor production, particularly following cancer cell treatment with coagulation factor VIIa. In vivo, cells undergoing epithelial-to-mesenchymal transition exhibited an increased metastatic potential. Furthermore, injections of the TF-blocking antibody (CNTO 859) delayed the initiation of A431 tumors in immunodeficient mice, and reduced tumor growth, vascularization, and vascular endothelial growth factor expression. Collectively, our data suggest that TF is regulated by both oncogenic and differentiation pathways, and that it functions in tumor initiation, tumor growth, angiogenesis, and metastasis. Thus, TF could serve as a therapeutic target in EGFR-dependent malignancies.

Contribution of host-derived tissue factor to tumor neovascularization

OBJECTIVE

The role of host-derived tissue factor (TF) in tumor growth, angiogenesis, and metastasis has hitherto been unclear and was investigated in this study.

METHODS AND RESULTS

We compared tumor growth, vascularity, and responses to cyclophosphamide (CTX) of tumors in wild-type (wt) mice, or in animals with TF levels reduced by 99% (low-TF mice). Global growth rate of 3 different types of transplantable tumors (LLC, B16F1, and ES teratoma) or metastasis were unchanged in low-TF mice. However, several unexpected tumor/context-specific alterations were observed in these mice, including: (1) reduced tumor blood vessel size in B16F1 tumors; (2) larger spleen size and greater tolerance to CTX toxicity in the LLC model; (3) aborted tumor growth after inoculation of TF-deficient tumor cells (ES TF(-/-)) in low-TF mice. TF-deficient tumor cells grew readily in mice with normal TF levels and attracted exclusively host-related blood vessels (without vasculogenic mimicry). We postulate that this complementarity may result from tumor-vascular transfer of TF-containing microvesicles, as we observed such transfer using human cancer cells (A431) and mouse endothelial cells, both in vitro and in vivo.

CONCLUSIONS

Our study points to an important but context-dependent role of host TF in tumor formation, angiogenesis and therapy.

Published randomized controlled trials of drug therapy for dementia often lack complete data on harm

OBJECTIVE

The objective of the study was to determine the extent to which published randomized controlled trials (RCTs) report data on harm.

STUDY DESIGN AND SETTING

A systematic search strategy was used to identify RCTs published between 1996 and 2005 on the use of cholinesterase inhibitors or atypical antipsychotics in patients with dementia. A structured abstraction form was used to determine if data on mortality or serious adverse events were reported and if the articles followed Consolidated Standards of Reporting Trials format for reporting harm.

RESULTS

Thirty-three RCTs were identified (27 on cholinesterase inhibitors and 6 on atypical antipsychotics). Nineteen trials (58%) had explicit data on mortality and only four (12%) reported regulatory-agency-defined serious adverse events. Most abstracts (31, 94%) stated that harm was studied but few studies (9, 27%) provided a clear definition of the measures of harm.

CONCLUSIONS

Although most published RCTs state that they examine harm, many failed to provide data on mortality and most lacked clear definitions or detailed analyses of harm. Better reporting of harm would provide timely and important information that could help physicians and the public to make more informed decisions.

Expression of human tissue factor under the control of the mouse tissue factor promoter mediates normal hemostasis in knock-in mice

BACKGROUND

Tissue factor (TF) is expressed widely at the subluminal surface of blood vessels and serves as the primary cellular initiator of the extrinsic pathway of blood coagulation. Lack of TF in mice resulted in lethality in utero, but human TF (huTF) expressed at low levels from a human minigene rescued null mice from prenatal death. Although these low-TF expressing transgenic mice developed to term, they had a significantly shorter life span and exhibited hemorrhage and fibrosis in the heart.

METHODS

Human TF knock-in (TFKI) mice were generated by replacing the first two exons of the mouse (murine) TF (muTF) gene with the huTF complete coding sequence, thus placing it under the control of the endogenous muTF promoter.

RESULTS

Expression of huTF in the TFKI mice was similar to muTF in wild-type (wt) mice. The TFKI mice showed no microscopic evidence of spontaneous hemorrhage in the heart, nor cardiac fibrosis at up to 18 months of age. Immunohistochemistry showed that huTF was expressed in cells surrounding blood vessels in TFKI mice. Coagulation activity of brain homogenates from TFKI mice was comparable with that from wt brain. Cardiac hemorrhage similar to that of the low-TF transgenic mice occurred in the TFKI mice when huTF was blocked by a neutralizing anti-huTF monoclonal antibody.

CONCLUSION

We generated a transgenic mouse line that expresses huTF under the control of the endogenous muTF promoter at physiological levels. Our results suggest that huTF can fully reconstitute the murine coagulation system and mediate normal hemostasis.

Expression of human tissue factor under the control of the mouse tissue factor promoter mediates normal hemostasis in knock-in mice

BACKGROUND

Tissue factor (TF) is expressed widely at the subluminal surface of blood vessels and serves as the primary cellular initiator of the extrinsic pathway of blood coagulation. Lack of TF in mice resulted in lethality in utero, but human TF (huTF) expressed at low levels from a human minigene rescued null mice from prenatal death. Although these low-TF expressing transgenic mice developed to term, they had a significantly shorter life span and exhibited hemorrhage and fibrosis in the heart.

METHODS

Human TF knock-in (TFKI) mice were generated by replacing the first two exons of the mouse (murine) TF (muTF) gene with the huTF complete coding sequence, thus placing it under the control of the endogenous muTF promoter.

RESULTS

Expression of huTF in the TFKI mice was similar to muTF in wild-type (wt) mice. The TFKI mice showed no microscopic evidence of spontaneous hemorrhage in the heart, nor cardiac fibrosis at up to 18 months of age. Immunohistochemistry showed that huTF was expressed in cells surrounding blood vessels in TFKI mice. Coagulation activity of brain homogenates from TFKI mice was comparable with that from wt brain. Cardiac hemorrhage similar to that of the low-TF transgenic mice occurred in the TFKI mice when huTF was blocked by a neutralizing anti-huTF monoclonal antibody.

CONCLUSION

We generated a transgenic mouse line that expresses huTF under the control of the endogenous muTF promoter at physiological levels. Our results suggest that huTF can fully reconstitute the murine coagulation system and mediate normal hemostasis.

Expression of ovarian steroid hormone receptors in tuberoinfundibular dopaminergic neurones during pregnancy and lactation

During late-pregnancy, tuberoinfundibular dopaminergic (TIDA) neurones, a critical component of the negative-feedback loop regulating prolactin secretion, become unresponsive to the stimulatory effects of prolactin. The change in TIDA responsiveness to prolactin at this time results in a decrease in dopamine secretion and a prolactin surge. As the onset of parturition and the antepartum prolactin surge depend on the withdrawal of progesterone in the presence of oestrogen, it is likely that ovarian steroid hormones mediate this change in TIDA responsiveness. To determine whether ovarian steroids can directly modulate TIDA activity, and whether changes of receptor numbers might contribute to overall steroid-regulation of these neurones, we investigated the level of oestrogen receptor alpha (ERalpha) and progesterone receptor (PR) expression within TIDA neurones during pregnancy and lactation. Animals were sacrificed on dioestrous, days 12, 19 and 21 of pregnancy and day 5 of lactation, and the proportion of TIDA neurones expressing ERalpha or PR, as well as the total number of PR expressing cells within the arcuate nucleus, was determined. Approximately 75% and 55% of tyrosine hydroxylase neurones expressed ERalpha and PR, respectively. Levels of steroid receptor expression within TIDA neurones remained fairly constant, except for an increase in ERalpha on days 12 and 19 of pregnancy compared to dioestrous and lactation day 5. The presence of steroid receptors on TIDA neurones during pregnancy and lactation supports the concept of a direct effect of steroid hormones on these neurones at this time. Thus, steroid hormones may directly act on TIDA neurones to regulate maternal prolactin secretion. The relatively stable level of expression during late pregnancy suggests that a shift in steroid receptor expression during late pregnancy does not contribute to the change in TIDA responsiveness to prolactin at this time.

αv Integrin-Targeted Immunoconjugates Regress Established Human Tumors in Xenograft Models

PURPOSE

Targeted delivery of cytotoxic agents to solid tumors through cell surface antigens can potentially reduce systemic toxicity and increase the efficacy of the targeted compounds. The purpose of this study was to show the feasibility of treating solid tumors by targeting alpha(v) integrins with antibody-maytansinoid conjugates and to test the relative in vivo activities of several linker-maytansinoid chemistries.

EXPERIMENTAL DESIGN

CNTO 364, CNTO 365, and CNTO 366 are targeted cytotoxic agents created by conjugating the CNTO 95 anti-alpha(v) integrin antibody with three distinct maytansinoid-linker structures. These structures were designed to have varying degrees of chemical substitution surrounding the disulfide bond linking the cytotoxic agent to the antibody. A model conjugate was shown to be specifically cytotoxic in vitro and highly active against established human tumor xenografts in immunocompromised rats. The in vivo antitumor activities of CNTO 364, CNTO 365, and CNTO 366 were compared in rat xenograft models.

RESULTS

CNTO 365, with a linker chemistry of expected intermediate stability, was shown to be substantially more active than the other two conjugates with lesser or greater substitution around the disulfide linkage.

CONCLUSION

CNTO 95-maytansinoid immunoconjugates are potent antitumor agents against alpha(v) integrin-expressing human carcinomas. These studies show for the first time the feasibility of targeting alpha(v) integrins on solid tumors with tumor-activated prodrugs. The DM4 linker-maytansinoid configuration of CNTO 365 was substantially more active in the models tested here when compared with alternative configurations with greater or lesser chemical substitution surrounding the linker.

Temperament and response to the Trier Social Stress Test

OBJECTIVE

The personality characteristics behavioural inhibition and neuroticism have been associated with mood and anxiety disorders and, in some studies, hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. We recently reported that low levels of Novelty Seeking were associated with elevated plasma cortisol responses to the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test in healthy adults with no psychiatric disorder. The present study tested the association between temperament and HPA axis function in the same group of subjects using a standardized psychosocial neuroendocrine stress test.

METHOD

Subjects completed diagnostic interviews, questionnaires, and the Trier Social Stress Test (TSST).

RESULTS

Novelty Seeking was inversely associated with plasma cortisol concentrations at baseline and throughout the TSST, but was not related to adrenocorticotropic hormone (ACTH) levels.

CONCLUSION

Results of this study extend our previous finding in the Dex/CRH test to a psychosocial stress test. Future investigations are needed to replicate these findings and further elucidate how temperament and personality are linked to HPA function.

CNTO 859, a humanized anti-tissue factor monoclonal antibody, is a potent inhibitor of breast cancer metastasis and tumor growth in xenograft models

Thromboembolic complications are frequently associated with advanced cancer. Interestingly, one of the major initiators of blood coagulation, tissue factor (TF), is reported to be overexpressed in several tumor types and can be found on both tumor cells and tumor vasculature. Although the exact mechanisms have yet to be elucidated, TF expressed on tumor cells can trigger intracellular signaling events through various pathways that can lead to tumor angiogenesis, proliferation, and metastasis. There exists preclinical evidence that disruption of TF dependent signaling can effectively inhibit tumor cell migration, metastasis, and angiogenesis. Here, we report for the first time that an antibody to tissue factor can also prevent tumor growth in vivo. Prophylactic administration of CNTO 859, a humanized anti-human TF antibody, was shown to inhibit experimental lung metastasis of MDA-MB-231 human breast carcinoma cells by over 99% compared to a control antibody. Furthermore, therapeutic doses of CNTO 859 were shown to reduce tumor incidence and growth of orthotopically implanted MDA-MB-231 cells.

Readers should systematically assess methods used to identify, measure and analyze confounding in observational cohort studies

OBJECTIVE

To describe techniques used to address confounding in published observational studies.

STUDY DESIGN AND SETTING

A systematic literature review identified studies using administrative or registry data to investigate health effects of drug therapies. Studies published from January 2001 to December 2005 came from BMJ, New England Journal of Medicine, Lancet, Annals of Internal Medicine, and JAMA. A structured abstraction form was used to collect information about confounding.

RESULTS

The search identified 29 studies. Twenty-two studies (76%) had 10,000 or more subjects and 18 (62%) used a mortality outcome. None mentioned use of a literature search to identify confounders, however, 28 (97%) listed confounders included, and 26 (90%) listed confounders not included in the study. Eighteen (62.1%) discussed the validity of confounder data. Most (22, or 76%) studies included a table with the distribution of confounders but none used effect size to assess imbalance between comparison groups. Almost all studies used regression techniques (28, or 97%); fewer used stratification (16, or 55%) or matching (four, or 14%) to address confounding. Eleven (40%) studies discussed sensitivity analyses.

CONCLUSION

Published cohort studies routinely include a list of potential confounders but there is room for improvement in confounder identification, measurement, and analysis.

Differential effects of centrally-administered oestrogen antagonist ICI-182,780 on oestrogen-sensitive functions in the hypothalamus

Oestrogen actions within the hypothalamus are essential for a range of reproductive functions. In this study, we sought to develop a method for suppressing central oestrogen action without affecting peripheral oestrogenic effects. We administered the oestrogen receptor antagonist ICI-182,780 (ICI) via crystalline implants into the left lateral ventricle or the arcuate nucleus and measured the effectiveness of this drug on three endpoints known to be regulated by oestrogen: gonadotrophin-releasing hormone (GnRH) pulse frequency, progesterone receptor expression and the generation of a sustained prolactin surge during late pregnancy. To confirm that central ICI administration had no effect on peripheral actions of oestrogen, we monitored changes in uterine weight. Intracerebroventricular ICI treatment reversed the inhibitory effects of oestrogen on GnRH pulse frequency, as measured by plasma luteinising hormone pulse frequency. No effect on the oestrogenic induction of progesterone receptors within the arcuate nucleus or ventromedial hypothalamus was observed; however, a small yet significant reduction in progesterone receptor expression within dopaminergic neurones in the arcuate nucleus was observed. Intracerebroventricular or direct crystalline ICI administration to the arcuate nucleus did not change the serum prolactin level during late pregnancy. Central administration of ICI did not affect uterine weight, and thus did not have a peripheral effect. These data suggest that central administration of ICI can overcome some actions of oestrogen in the brain, such as GnRH pulse frequency, but does not affect other oestrogen mediated actions, including the induction of progesterone receptors or the antepartum prolactin surge. Thus, it appears that there is a differential sensitivity to the inhibition of central oestrogen actions by ICI.

Therapeutic potential of cytokine and chemokine antagonists in cancer therapy

A new paradigm is becoming widely accepted, that chronic inflammation, driven in part by chemokines and cytokines at the site of a tumour, may facilitate tumour progression instead of promoting anti-tumour immunity. Tumours and activated stromal cells secrete pro-inflammatory chemokines and cytokines that act either directly or indirectly through stimulation of the vascular endothelium to recruit leukocytes to the tumour. After activation, these tumour-associated leukocytes release angiogenic factors, mitogens, proteolytic enzymes, and chemotactic factors, recruiting more inflammatory cells and stimulating angiogenesis to sustain tumour growth and facilitate tumour metastasis. Breaking this cycle by inhibiting targets such as cytokines, chemokines and other inflammatory mediators, either alone, or more realistically, in combination with other therapies, such as anti-angiogenic or cytotoxic agents, may provide highly efficacious therapeutic regimens for the treatment of malignancies. This article reviews anti-cytokine and anti-chemokine therapies being pursued in cancer, and discusses in more detail anti-tumour necrosis factor-alpha (TNF) approaches.

Relationships between serotonin transporter promoter polymorphism, platelet serotonin transporter binding and clinical phenotype in suicidal and non-suicidal adolescent inpatients

Relationships between the serotonin transporter promoter polymorphism (5-HTTLPR), platelet serotonin transporter (SERT) binding and clinical phenotype were examined in 32 suicidal and 28 non-suicidal Ashkenazi Israeli adolescent psychiatric inpatients. The 5-HTTLPR polymorphism was not associated with transporter binding or with suicidality or other clinical phenotypes. However, in the suicidal group, a significant positive correlation between platelet SERT density and anger scores (n=32, r=.40; p=.027) and a negative correlation between platelet count and trait anxiety (n=32, r=-.42; p=.034) were observed.

Tumor necrosis factor-? in the pathogenesis and treatment of cancer

The critical pathogenic role of tumor necrosis factor (TNF)alpha in inflammatory disorders such as rheumatoid arthritis and inflammatory bowel disease is well established. The role played by TNFalpha in both the treatment and pathogenesis of cancer remains less understood. Recent advances help to create a framework for understanding seemingly paradoxical effects of TNFalpha as both an anti-tumour agent and a mediator of tumour growth. High pharmacological doses of TNFalpha combined with chemotherapy can regress otherwise intractable tumours, and efforts continue to optimize delivery to avoid severe toxicities. Mounting evidence demonstrates that pathophysiological concentrations of endogenous TNFalpha act to promote tumour genesis and growth. The cellular and molecular pathways mediating these phenomena are starting to be clarified. Current data support the continued development of both TNFalpha and anti-TNFalpha therapy for clinical treatment of cancers in distinct settings.

Autism as a disorder of neural information processing: directions for research and targets for therapy

The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which they feed, is hampered by the large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging, and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself.

Serotonin uptake and metabolism by cultured guinea pig airway smooth muscle cells

Serotonin (5-hydroxytryptamine, 5-HT) is synthesized and released in the airways by pulmonary neuroendocrine cells located in the vicinity of airway smooth muscle (ASM). The aim of this study was to determine whether ASM cells contribute to the inactivation of serotonin, and investigate the role of the serotonin transporter (SERT) and monoamine oxidase (MAO) in this process. Cultured guinea pig tracheal smooth muscle cells, maintained in culture medium containing serotonin for 1-4 days, induced a decrease in 5-HT and increase in 5-HIAA in the culture medium. Changes in indole concentrations were prevented by fluvoxamine and iproniazid. Na+-sensitive [3H]-serotonin uptake into cultured ASM cells was time- and concentration-dependent (Km, 561 nM; Vmax, 1.06 pmol/mg protein/min), and inhibited by clomipramine (IC50, 13.7 nM), fluvoxamine (IC50, 0.16 microM) and fluoxetine (IC50, 0.32 microM). Western blot analysis with an anti-SERT antibody revealed a single 115 kDa immunoreactive band in ASM cell lysates. The results of this study suggest that ASM contributes to the uptake and metabolism of serotonin via SERT and MAO, respectively, and may therefore play a role in the inactivation of endogenous serotonin generated within the airway wall.

Neurobiology and neuroimmunology of Tourette?s syndrome: an update

Tourette's syndrome is a childhood-onset neuropsychiatric disorder characterized by the presence of both multiple motor and vocal tics. While the pathogenesis at a molecular and cellular level remains unknown, structural and functional neuroimaging studies point to the involvement of the basal ganglia and related cortico-striato-thalamo-cortical circuits as the neuroanatomical site for Tourette's syndrome. Moreover, Tourette's syndrome has a strong genetic component, and considerable progress has been made in understanding the mode of transmission and in identifying potential genomic loci. Summaries of recent findings in these areas will be reviewed, followed by a critical overview of findings both supporting and challenging the proposed autoimmune hypothesis of Tourette's syndrome. We conclude that Tourette's syndrome is a heterogeneous disorder, and that immune factors may indeed be involved in some patients.

The reproductive response of rams to thyroidectomy: mediation by impaired inhibin feedback rather than a change in LH pulsatility

A series of experiments was conducted to examine the mechanism by which removal of the thyroid glands in seasonally suppressed rams brings about rapid testicular growth. In the first experiment, thyroidectomy at the nadir of the testicular cycle (late winter) initiated testis growth without any detectable change in the extent of spermatogenesis compared with sham-operated controls. The serum concentration of FSH, but not LH, was also markedly increased by thyroidectomy. In the second experiment, serum FSH concentration was again increased by thyroidectomy in late winter but there was no effect of thyroidectomy on LH concentration, LH pulses (measured in frequent blood samples) or testosterone concentration. Furthermore, there was no evidence of a change in central dopaminergic inhibition of GnRH, as measured by the pulsatile LH response to an i.m. injection of the dopaminergic D(2) agonist bromocriptine or antagonist sulpiride. The rapid increase in FSH concentration occurred despite a markedly increased serum inhibin A concentration in thyroidectomized rams. Therefore, the efficacy of inhibin feedback was examined by testing the FSH-suppressive effect of an inhibin preparation (5 ml charcoal-stripped bovine follicular fluid i.v.) in long-term thyroidectomized and thyroid intact castrated rams. Bovine follicular fluid suppressed FSH concentrations in control rams as expected but in marked contrast, was completely without effect in thyroidectomized animals. In castrated rams, the FSH concentration was only marginally increased by thyroidectomy, indicating that there is a major component of the mediation of the effects of thyroidectomy that is testicular in origin. It was concluded that a reduction in the ability of endogenous inhibin to inhibit FSH release at the pituitary, rather than a hypothalamic mechanism, is the primary cause of the stimulation of testis growth by thyroidectomy.

Cortisol response to a cognitive stress challenge in posttraumatic stress disorder (PTSD) related to childhood abuse

Preclinical studies show that animals with a history of chronic stress exposure have increased hypothalamic-pituitary-adrenal (HPA) axis reactivity following reexposure to stress. Patients with posttraumatic stress disorder (PTSD) have been found to have normal or decreased function of the HPA axis, however no studies have looked at the HPA response to stress in PTSD. The purpose of this study was to assess cortisol responsivity to a stressful cognitive challenge in patients with PTSD related to childhood abuse. Salivary cortisol levels, as well as heart rate and blood pressure, were measured before and after a stressful cognitive challenge in patients with abuse-related PTSD (N=23) and healthy comparison subjects (N=18). PTSD patients had 61% higher group mean cortisol levels in the time period leading up to the cognitive challenge, and 46% higher cortisol levels during the time period of the cognitive challenge, compared to controls. Both PTSD patients and controls had a similar 66-68% increase in cortisol levels from their own baseline with the cognitive challenge. Following the cognitive challenge, cortisol levels fell in both groups and were similar in PTSD and control groups. PTSD patients appeared to have an increased cortisol response in anticipation of a cognitive challenge relative to controls. Although cortisol has been found to be low at baseline, there does not appear to be an impairment in cortisol response to stressors in PTSD.

Oestradiol microimplants in the ventromedial preoptic area inhibit secretion of luteinizing hormone via dopamine neurones in anoestrous ewes

Oestradiol exerts a season-specific negative feedback effect on the GnRH/LH neurosecretory system of the Suffolk ewe. This neuroendocrine suppression is mediated in part by dopamine A15 neurones, but these neurones do not possess the oestrogen receptor. Based on indirect evidence, we hypothesized that oestrogen receptor-containing neurones in the ventromedial preoptic area (vmPOA) may be the initial step in a neuronal system whereby oestradiol suppresses GnRH secretion during the non-breeding season. To test this, three experiments were conducted using ovariectomized ewes receiving either empty or oestradiol-containing bilateral microimplants directed at the vmPOA or s.c. subcutaneous oestradiol-containing implants. In the first experiment, LH pulse frequency was measured on days 0, 1, 7 and 14 of treatment during seasonal anoestrus. In vmPOA oestradiol and s.c. oestradiol groups only, LH pulse frequency was suppressed on days 7 and 14, with maximal suppression evident by day 7. In the second experiment, this protocol was repeated during the breeding season, with LH pulses examined on days 0 and 7; LH pulse frequency did not change in any group. The third experiment tested if the effect of vmPOA oestradiol during anoestrus could be overcome by an injection of the dopamine-D2 receptor antagonist (-)-sulpiride. The vmPOA microimplants and s.c. oestradiol implants again suppressed LH pulse frequency and this was reversed by sulpiride in vmPOA oestradiol ewes. We conclude that oestradiol acts on cells in the vmPOA to stimulate a system involving dopamine neurones that inhibits GnRH/LH pulsatility in the anoestrous ewe.

Localized antimicrobial peptide expression in human gingiva

The stratified epithelia of the oral cavity are continually exposed to bacterial challenge that is initially resisted by innate epithelial factors and by the recruitment of neutrophils. Antimicrobial peptides from phagocytes and epithelia contribute to this antimicrobial barrier. Using antibodies and in situ hybridization, we explored antimicrobial peptide expression in the varied epithelia of the periodontium and in cultured gingival epithelial cells. In gingival tissue, mRNA for the beta-defensins, human beta-defensin 1 (hBD-1) and human beta-defensin 2 (hBD-2) was predominately localized in suprabasal stratified epithelium and the peptides were detected in upper epithelial layers consistent with the formation of the stratified epithelial barrier. In cultured epithelial cells, both hBD-1 and -2 peptides were detected only in differentiating, involucrin-positive epithelial cells, although hBD-2 required stimulation by proinflammatory mediators or bacterial products for expression. Beta-defensins were not detected in junctional epithelium (JE) that serves as the attachment to the tooth surface. In contrast, alpha-defensins and cathelicidin family member LL-37 were detected in polymorphonuclear neutrophils (PMNs) that migrate through the JE, a localization that persists during inflammation, when the JE and surrounding tissue are highly infiltrated with PMNs. Thus, the undifferentiated JE contains exogenously expressed alpha-defensins and LL-37, and the stratified epithelium contains endogenously expressed beta-defensins. These findings show that defensins and other antimicrobial peptides are localized in specific sites in the gingiva, are synthesized in different cell types, and are likely to serve different roles in various regions of the periodontium.

Maternal sertraline treatment and serotonin transport in breast-feeding mother-infant pairs

OBJECTIVE

Pharmacological treatment of postpartum depression is frequently complicated by the mother's desire to breast-feed. Although breast milk levels of several selective serotonin reuptake inhibitors (SSRIs) have been reported to be relatively low, a critical question is whether SSRI exposure during nursing results in clinically significant blockade of serotonin (5-HT) reuptake in infants. This study determined the degree of transporter blockade in infants exposed to sertraline through maternal breast milk.

METHOD

The extent of maternal and infant transporter blockade was assessed by measurement of platelet levels of 5-HT in 14 breast-feeding mother-infant pairs before and after 6-16 weeks of maternal treatment with sertraline for major depression with postpartum onset. Plasma sertraline and desmethylsertraline levels were obtained in 13 of these mothers and 11 of their infants.

RESULTS

Marked declines in platelet 5-HT levels of 70%-96% were observed in mothers after sertraline treatment, 25-200 mg/day. In contrast, infants showed little or no change in platelet 5-HT levels after exposure through breast-feeding. Mean levels of maternal plasma sertraline and its major metabolite, desmethylsertraline, were 30.7 ng/ml and 45.3 ng/ml, respectively. Drug and drug metabolite concentrations in the infants were at or below the lower limit of quantitation.

CONCLUSIONS

The data indicate that while mothers receiving clinical doses of sertraline experience substantial blockade of the platelet 5-HT transporter, platelet 5-HT uptake in nursing infants of treated mothers is unaltered. The observations suggest that mothers taking sertraline can breast-feed without appreciably affecting peripheral or central 5-HT transport in their infants.