Atypical ATMs: Broadening the phenotypic spectrum of ATM-associated hereditary cancer

Heterozygous, loss-of-function germline variants in ATM have been associated with an increased lifetime risk of breast, pancreas, prostate, stomach, ovarian, colorectal, and melanoma cancers. We conducted a retrospective review of thirty-one unrelated patients found to be heterozygous for a germline pathogenic variant in ATM and identified a significant proportion of patients in this cohort with cancers not currently associated with the ATM hereditary cancer syndrome, including carcinomas of the gallbladder, uterus, duodenum, kidney, and lung as well as a vascular sarcoma. A comprehensive review of the literature found 25 relevant studies where 171 individuals with a germline deleterious ATM variant have been diagnosed with the same or similar cancers. The combined data from these studies were then used to estimate the prevalence of germline ATM pathogenic variants in these cancers, which ranged between 0.45% and 2.2%. Analysis of tumor sequencing performed in large cohorts demonstrated that the frequency of deleterious somatic ATM alterations in these atypical cancers equaled or exceeded the alteration frequency in breast cancer and occurred at a significantly higher rate than in other DNA-damage response tumor suppressors, namely BRCA1 and CHEK2. Furthermore, multi-gene analysis of somatic alterations in these atypical cancers demonstrated significant co-occurrence of pathogenic alterations in ATM with BRCA1 and CHEK2, while there was significant mutual exclusivity between pathogenic alterations in ATM and TP53. This indicates that germline ATM pathogenic variants may play a role in cancer initiation and progression in these atypical ATM malignancies, potentially influencing these cancers to be driven toward DNA-damage repair deficiency and away from loss of TP53. As such, these findings provide evidence for broadening of the ATM-cancer susceptibility syndrome phenotype to improve the recognition of affected patients and provide more efficacious, germline-directed therapies.

Understanding patient partnership in health systems: lessons from the Canadian patient partner survey

OBJECTIVES

To examine the sociodemographic characteristics, activities, motivations, experiences, skills and challenges of patient partners working across multiple health system settings in Canada.

DESIGN

Online cross-sectional survey of self-identified patient partners.

SETTING

Patient partners in multiple jurisdictions and health system organisations.

PARTICIPANTS

603 patient partners who had drawn on their experiences with the health system as a patient, family member or informal caregiver to try to improve it in some way, through their involvement in the activities of a group, organisation or government.

RESULTS

Survey respondents predominantly identified as female (76.6%), white (84%) and university educated (70.2%) but were a heterogeneous group in the scope (activities and organisations), intensity (number of hours) and longevity (number of years) of their role. Primary motivations for becoming a patient partner were the desire to improve the health system based on either a negative (36.2%) or positive (23.3%) experience. Respondents reported feeling enthusiastic (83.6%), valued (76.9%) and needed (63.3%) always or most of the time; just under half felt they had always or often been adequately compensated in their role. Knowledge of the health system and the organisation they partner with are key skills needed. Two-thirds faced barriers in their role with over half identifying power imbalances. Less than half were able to see how their input was reflected in decisions or changes always or most of the time, and 40.3% had thought about quitting.

CONCLUSIONS

This survey is the first of its kind to examine at a population level, the characteristics, experiences and dynamics of a large sample of self-identified patient partners. Patient partners in this sample are a sociodemographically homogenous group, yet heterogeneous in the scope, intensity and longevity of roles. Our findings provide key insights at a critical time, to inform the future of patient partnership in health systems.

Metachronous Advanced Neoplasia on Surveillance Colonoscopy in Patients With Young- vs Older-onset of Colorectal Cancer

The incidence of colorectal cancer (CRC) and cancer-related mortality has increased in patients <55 years old.¹ Consensus on optimal intervals for post-CRC surveillance colonoscopy in young patients is lacking. The primary endpoint of this study was comparison of rates of metachronous advanced neoplasia (AN) in patients diagnosed with CRC at <50 and 50-75 years. The secondary aim was to evaluate risk factors of metachronous AN.

Gastrointestinal Tract Lymphomas: A Review of the Most Commonly Encountered Lymphomas

CONTEXT.—

The gastrointestinal (GI) tract is the most common site of extranodal non-Hodgkin lymphoma, accounting for 20% to 40% of all extranodal lymphomas. The majority of these are systemic processes secondarily involving the GI tract. Primary GI lymphomas are less common, accounting for approximately 10% to 15% of all non-Hodgkin lymphoma. Most non-Hodgkin lymphoma involving the GI tract are of B-cell lineage, of which diffuse large B-cell lymphoma is the most common subtype, irrespective of location.

OBJECTIVE.—

To review the lymphoproliferative neoplasms of B-cell and T-cell lineage involving the luminal GI tract according to the most prevalent subtypes at each anatomic site.

DATA SOURCE.—

Systematic search of the PubMed database for updated literature on GI lymphomas epidemiology, subtypes, clinical, endoscopic, and genetic findings. Histologic images are derived from our collection of clinical cases.

CONCLUSIONS.—

The GI tract is the most common site of extranodal lymphoproliferative neoplasms. Recognition of the most frequently encountered GI lymphomas is imperative for patient management and treatment.

Increasing uptake of evidence-based screening services though a community health worker-delivered multimodality program: study protocol for a randomized pragmatic trial

BACKGROUND

Underserved ethnic minority populations experience significant disparities in HIV, hepatitis C virus (HCV), colorectal cancer (CRC), and cervical cancer incidence and mortality. Much of the excess burden of these diseases among underserved communities is due to lack of preventive care, including screening. Barriers to disease screening include low awareness, lack of access to care and health insurance, and cultural beliefs regarding disease prevention. Our current trial aims to examine community health worker (CHW)-delivered, home-based multi-modality screening for HIV, HCV, CRC, and cervical cancer simultaneously.

DESIGN

We are conducting a randomized pragmatic trial among 900 Haitian, Hispanic, and African-American participants from diverse underserved communities in South Florida. People between the ages of 50 and 65 who have not had appropriate HIV, HCV, CRC, and cervical cancer screening per United States Preventive Services Task Force (USPSTF) recommendations are eligible for the study. Participants are recruited by CHWs and complete a structured interview to assess multilevel determinants of disease risk. Participants are then randomized to receive HIV, HCV, CRC, and cervical cancer screening via navigation to care by a CHW (Group 1) or via CHW-delivered home-based screening (Group 2). The primary outcome is completion of screening for each of these diseases within 6 months post-enrollment.

DISCUSSION

Our trial is among the first to examine the effectiveness of a CHW-delivered, multimodality, home-based disease-screening approach. If found to be effective, this approach may represent a cost-effective strategy for disease screening within underserved and underscreened minority groups.

TRIAL REGISTRATION

Clinical Trials.gov # NCT02970136, registered November 21, 2016.

Abstract LB-175: The malignancy associated change hypothesis tested through 3D cellular imaging

Early detection remains by far the most reliable and potent strategy in curing lung cancer. Many current approaches, however, are limited by poor sensitivity or specificity that increase health care costs and potentially risk patient health through unneeded and invasive procedures.

The association between cell morphology and cancer has been established in the cytology literature. However, the tumor field effect potentially introduces subtle changes into non-tumor cells that reside in the tumor microenvironment. This phenomenon has given rise to the malignancy associated change (MAC) hypothesis.

The Cell-CT™ platform and LuCED® test represent a promising new method for detecting lung cancer with high (92%) sensitivity and (95%) specificity that is based on alterations in cellular morphology.

We present a study of 3D morphological alterations in non-tumor cells obtained from sputum of healthy subjects and biopsy confirmed lung cancer patients. Three major cell types were analyzed from 235 patients: bronchial epithelial columnar, squamous intermediate, and mature macrophages (dust cells). We used the Cell-CT platform to measure over 700 different structural biosignatures for each cell. A classifier to test the degree to which the features discriminate between cells from normal or cancer patients was developed and its performance characterized by the area under the ROC curve (aROC) (Table 1). Hierarchical clustering analysis revealed biosignatures of nuclear chromatin organization to be the most differentiating between macrophages from healthy subjects and patients with cancer.

Table 1. Classifier development and performance characteristics

Cell TypeNumber of cells from cancer patientsNumber of cells from normal patientsSupervised Learning – aROCSquamous Intermediate4,6849530.70Macrophages7,2191,3660.75Columnar cells11,7742,9110.80

Our results confirm the MAC hypothesis based on 3D cellular imaging and suggest that cancer presence in the lung can be detected in patient's sputum based on the morphologic alterations in non-tumor cells. This is important as cancer cells are rare in early stages of cancer, posing challenges in terms of detection sensitivity and specificity.

Further work will emphasize boosting of the performance figures above based on the combination of results from the differing methods presented.

Citation Format: Michael Meyer, Laimonas Kelbauskas, Rahul Katdare, Chris Presley, Celeste Hamilton, Daniel Sussman, Tim Bell, Alan Nelson. The malignancy associated change hypothesis tested through 3D cellular imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-175.

Olmesartan-Induced Enteropathy

Olmesartan-induced enteropathy mimics celiac disease clinically and pathologically. As in celiac disease, the pathologic findings are villous atrophy and increased intraepithelial lymphocytes. Clinical presentation of olmesartan-induced enteropathy includes diarrhea, weight loss, and nausea. In contrast to celiac disease, tissue transglutaminase is not elevated and there is no response to a gluten-free diet. Including this entity in the differential diagnosis of sprue-like enteropathy is critical for its early diagnosis since replacing olmesartan with an alternative antihypertensive drug can simplify the diagnostic workup and provide both clinical and histologic improvement.

Adherence and persistence of mirabegron and anticholinergic therapies in patients with overactive bladder: a real-world claims data analysis

BACKGROUND

Adherence and persistence rates of anticholinergic (ACH) therapies have been well described. To date, few studies describe these metrics for mirabegron in patients with overactive bladder.

METHODS

This retrospective analysis of MarketScan^® database assessed adherence and persistence of patients receiving either mirabegron or ACH. Study eligibility required an index date (first prescription filled) between July 2012 and June 2013 with 12 months of continuous enrolment preindex date and 12 months of follow-up. Adherence was defined as a proportion of days covered of ≥ 80% among patients with at least 2 fills of index medication. Persistence measures included treatment failure described as either treatment discontinuation (medication supply gap ≥ 30 days) or switching to a different medication. A medication supply gap of ≥ 45 days was used as a sensitivity analysis.

RESULTS

The mean age of mirabegron users (n = 4037) was 67 years and 43% were ACH naïve while the mean age of ACH users was 62 years (n = 67,943). Over the 12-month follow-up period, 44% of patients treated with mirabegron and 31% of patients treated with ACH were adherent to their indexed medications. Treatment failure was 81% for mirabegron and 88% for ACH. Most mirabegron treatment failures were because of treatment discontinuation (67%) versus switching to ACH therapy (14%). The ACH discontinuation rate was 84% and treatment switching rate was 4%. The mean (standard deviation) time to treatment failure was 143 (130) days for mirabegron and 69 (69) days for ACH. Adherence and persistence patterns were similar in the sensitivity analysis using a ≥ 45-day supply gap threshold.

CONCLUSIONS

This real-world study demonstrated low adherence and persistence to mirabegron similar to ACH therapies.

Neuroanatomical features in soldiers with post-traumatic stress disorder

Background

Posttraumatic stress disorder (PTSD), an anxiety disorder that can develop after exposure to psychological trauma, impacts up to 20 % of soldiers returning from combat-related deployment. Advanced neuroimaging holds diagnostic and prognostic potential for furthering our understanding of its etiology. Previous imaging studies on combat-related PTSD have focused on selected structures, such as the hippocampi and cortex, but none conducted a comprehensive examination of both the cerebrum and cerebellum. The present study provides a complete analysis of cortical, subcortical, and cerebellar anatomy in a single cohort. Forty-seven magnetic resonance images (MRIs) were collected from 24 soldiers with PTSD and 23 Control soldiers. Each image was segmented into 78 cortical brain regions and 81,924 vertices using the corticometric iterative vertex based estimation of thickness algorithm, allowing for both a region-based and a vertex-based cortical analysis, respectively. Subcortical volumetric analyses of the hippocampi, cerebellum, thalamus, globus pallidus, caudate, putamen, and many sub-regions were conducted following their segmentation using Multiple Automatically Generated Templates Brain algorithm.

Results

Participants with PTSD were found to have reduced cortical thickness, primarily in the frontal and temporal lobes, with no preference for laterality. The region-based analyses further revealed localized thinning as well as thickening in several sub-regions. These results were accompanied by decreased volumes of the caudate and right hippocampus, as computed relative to total cerebral volume. Enlargement in several cerebellar lobules (relative to total cerebellar volume) was also observed in the PTSD group.

Conclusions

These data highlight the distributed structural differences between soldiers with and without PTSD, and emphasize the diagnostic potential of high-resolution MRI.

Durable improvements in urinary incontinence and positive treatment response in patients with idiopathic overactive bladder syndrome following long-term onabotulinumtoxinA treatment: Final results of 3.5-year study

OBJECTIVES

Here we present the final results from an extension study assessing long-term onabotulinumtoxinA treatment (3.5 years) in patients with idiopathic overactive bladder.

METHODS

Patients who completed either of 2 Phase III trials were eligible to enter a 3-year extension study in which they received multiple onabotulinumtoxinA (100 U) treatments. Data were analyzed for the overall population of patients who received 100 U in any treatment cycle (n=829) and within discrete subgroups of patients who received exactly 1 (n=105), 2 (n=118), 3 (n=117), 4 (n=83), 5 (n=46), or 6 (n=33) treatments of the 100 U dose throughout the study (n=502).

RESULTS

Of the 829 patients enrolled, 51.7 % completed the study. Discontinuations due to AEs/lack of efficacy were low (5.1/5.7 %); other reasons were not treatment-related. Mean reductions from baseline in urinary incontinence (UI) episodes/day (week 12; co-primary endpoint) were consistent among discrete subgroups who received 1 (-3.1), 2 (-2.9, -3.2), 3 (-4.1 to -4.5), 4 (-3.4 to -3.8), 5 (-3.0 to -3.6), or 6 (-3.1 to -4.1) treatments. A consistently high proportion of patients reported improvement/great improvement on the Treatment Benefit Scale (week 12; co-primary endpoint) in the discrete subgroups across all treatments (70.0-93.5 %). Median time to request retreatment was ≤6 months for 34.2 %, >6-≤12 months for 37.2 %, and >12 months for 28.5 % of patients. Most common AE was UTI, with no changes in safety profile over time.

CONCLUSION

Long-term onabotulinumtoxinA treatment resulted in consistent reductions in UI and high proportions of patients reporting improvement after each treatment, with no new safety findings.

Abstract A01: Exploring phosphatase and tensin homolog (PTEN) loss as a potential predictive marker for response to everolimus in patients with pancreatic neuroendocrine tumors (PNETs)

Introduction: Identification of patients with exquisite sensitivity and/or durable responses to targeted therapies may lead to improved patient selection and allow for more rational treatment designs. Loss of PTEN tumor suppressor gene function, usually due to deletion, leads to activation of phosphatidylinositol 3-kinase/Akt and mammalian target of rapamycin (mTOR) signaling. The RADIANT-3 trial of everolimus in advanced PNETs demonstrated a significant prolongation of progression-free survival (PFS) from 4.6 months with placebo versus 11 months with everolimus. Despite the improvement in PFS, the response rate was only 5% among patients receiving everolimus. The index case for our study was an exceptional responder who had a significant radiological response as well as a PFS of 24 months, which were both better than expected from the literature. This led to the hypothesis that there may be mutational changes in genes affecting the mTOR pathway that could predict sensitivity to mTOR inhibitors. In this study, we specifically explored the role of PTEN loss as a potential predictive marker.

Methods and Materials: Between 2010 and 2014, patients with well-differentiated unresectable and metastatic PNETs treated at the University of Miami/Sylvester Comprehensive Cancer Center and Jackson Memorial Hospital with everolimus were identified. Eight patients had pathology specimens available for testing. PTEN loss detected by Fluorescence In Situ Hybridization (FISH) was carried out using a commercially available probe for cytoband 10q23. Patients' response to everolimus was evaluated through June 2014. The primary outcome was PFS. PTEN expression by immunohistochemistry (IHC) will also be performed and the results will be compared to those obtained by FISH.

Results: The median age was 60 years (range 45-78). 50% of the patients were females and 50% were males. Two patients had gastrinomas, 1 patient had an insulinoma, and five patients had non-functional PNETs. All patients had unresectable metastases to the liver. In addition to sandostatin LAR, the patients received everolimus starting at a dose of 10mg daily. Three patients were found to have deletion of PTEN. Of those, one patient did not tolerate everolimus and the PFS for the other two was 8 and 24 months respectively. Detection of PTEN loss by FISH yielded no results in 2 patients due to insufficient tumor left in the specimen. PFS in these 2 patients was 24 and 4 months respectively. Testing is ongoing in the last 3 patients and the PFS for these patients is 3, 10 and 13 months. PTEN expression by IHC is also ongoing and will be reported at the meeting.

Conclusion: The index case for this study had a PTEN deletion and had a partial response to treatment and prolonged disease control for 2 years with everolimus. Testing is ongoing in additional cases to determine if there is a consistent correlation between PTEN loss by FISH and PFS.

Citation Format: Moh'd Khushman, Joyce Slingerland, Yao-Shan Fan, Monica Garcia-Buitrago, Ernesto Bustinza, Maria Restrepo, Daniel Sussman, Caio Rocha-Lima, Peter Hosein. Exploring phosphatase and tensin homolog (PTEN) loss as a potential predictive marker for response to everolimus in patients with pancreatic neuroendocrine tumors (PNETs). [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr A01.

The autism puzzle: Diffuse but not pervasive neuroanatomical abnormalities in children with ASD

Autism Spectrum Disorder (ASD) is a clinically diagnosed, heterogeneous, neurodevelopmental condition, whose underlying causes have yet to be fully determined. A variety of studies have investigated either cortical, subcortical, or cerebellar anatomy in ASD, but none have conducted a complete examination of all neuroanatomical parameters on a single, large cohort. The current study provides a comprehensive examination of brain development of children with ASD between the ages of 4 and 18 years who are carefully matched for age and sex with typically developing controls at a ratio of one-to-two. Two hundred and ten magnetic resonance images were examined from 138 Control (116 males and 22 females) and 72 participants with ASD (61 males and 11 females). Cortical segmentation into 78 brain-regions and 81,924 vertices was conducted with CIVET which facilitated a region-of-interest- (ROI-) and vertex-based analysis, respectively. Volumes for the cerebellum, hippocampus, striatum, pallidum, and thalamus and many associated subregions were derived using the MAGeT Brain algorithm. The study reveals cortical, subcortical and cerebellar differences between ASD and Control group participants. Diagnosis, diagnosis-by-age, and diagnosis-by-sex interaction effects were found to significantly impact total brain volume but not total surface area or mean cortical thickness of the ASD participants. Localized (vertex-based) analysis of cortical thickness revealed no significant group differences, even when age, age-range, and sex were used as covariates. Nonetheless, the region-based cortical thickness analysis did reveal regional changes in the left orbitofrontal cortex and left posterior cingulate gyrus, both of which showed reduced age-related cortical thinning in ASD. Our finding of region-based differences without significant vertex-based results likely indicates non-focal effects spanning the entirety of these regions. The hippocampi, thalamus, and globus pallidus, were smaller in volume relative to total cerebrum in the ASD participants. Various sub-structures showed an interaction of diagnosis-by-age, diagnosis-by-sex, and diagnosis-by-age-range, in the case where age was divided into childhood (age < 12) and adolescence (12 < age < 18). This is the most comprehensive imaging-based neuro-anatomical pediatric and adolescent ASD study to date. These data highlight the neurodevelopmental differences between typically developing children and those with ASD, and support aspects of the hypothesis of abnormal neuro-developmental trajectory of the brain in ASD.

•

Thorough analysis of neuroanatomical patterns in children and adolescents with ASD

•

Cortical, subcortical, and cerebellar development is assessed.

•

Total brain volume is smaller in males with ASD compared with Controls.

•

Cortical thickness in ASD does not decrease between childhood and adulthood.

•

Hippocampi, thalamus, globus pallidus and cerebellum are relatively smaller in ASD.

Abstract B46: FIT FOR LIFE: Increasing prevention and early detection of colorectal cancer for the medically disenfranchised

Background: Racial/ethnic minorities, low-income individuals and recent immigrants shoulder a disproportionate burden of colorectal cancer (CRC) mortality. In Florida, Blacks and Hispanics remain at an increased risk of colorectal cancer (CRC) compared to non-Hispanic Whites (NHW). In the Miami metropolitan area, this disparity is most prominent within the ethnic enclaves of Little Haiti and Hialeah, comprised predominately of Haitian and Hispanic Americans, respectively These communities experience an increased rate of late-stage CRC diagnosis relative to the state as a whole, largely due to lack of access to, and utilization of, CRC screening. Fecal immunochemical testing (FIT) has proved successful in addressing screening barriers for other medically-underserved communities. The present study represents a novel method for FIT delivery and uptake, particularly for the medically disenfranchished. Community Health Workers (CHWs), indigenous to Little Haiti and Hialeah, identified unscreened individuals, educated them about how to appropriately use FIT, and then provided them a postage-paid envelope to return completed tests to a laboratory for processing. Here we report preliminary acceptability and feasibility data for this approach.

Methods: The FIT for Life screening program was available to all persons residing in Little Haiti and Hialeah 50 and 75 years old, who were unscreened or underscreened according to US Preventive Task Force recommendations, and considered average risk for CRC based on a brief screener. Our team worked closely with community partners to identify the CHWs, who ultimately were responsible for participant recruitment and intervention delivery. Following FIT return, a research assistant contacted participants to ask a series of questions in their language of preference about their perceived acceptability of FIT as a modality for CRC prevention. Any participant, identified as FIT positive was navigated to timely colonoscopy

Results: To date, 221 participants (112 Hispanic, 109 Haitian) have been consented, received education on CRC screening, and were given the FIT kits. 92 Hispanics (82.1%) and 97 Haitians (88.9%) returned the FIT kits for processing. The test positive rate was 2.2% for Hispanics and 3.1% for Haitians. The mean quantity of blood in stool for positive tests was 896 ng/mL for Hispanics and 950 ng/mL for Haitians. The mean quantity of blood in stool for negative tests was 5.2 ng/mL for Hispanics and 4.8 ng/mL for Haitians. On follow-up clinical care, one Haitian participant was found to have an advanced stage CRC and a second did not want to undergo colonoscopy. Based on acceptability surveys, 100% of Hispanics and 90% of Haitians responded that they would use FIT again if offered for further screening; the same proportions would recommend the FIT with CHW method to friends and family members. Interestingly, 90.2% of Hispanics and only 5.0% of Haitians felt confident that FIT works as well as a CRC screening test that would be administered by a physician or nurse.

Conclusion: The pairing of CHWs with CRC screening by FIT appears to be an effective approach to disease prevention that is highly acceptable to study participants. Further examination of whether this method is needed. We have begun collaborating with Federally Qualified Health Centers (FQHC) in Little Haiti and Hialeah to explore the sustainability of this approach and to ensure that participants are linked to a medical home for ongoing cancer prevention.

Citation Format: Daniel Sussman, Monica Oriol, Martha Gonzalez, Heisy Asusta, Jose Ruiz, Dinah Trevil, Dorothy Parker, Erin Kobetz. FIT FOR LIFE: Increasing prevention and early detection of colorectal cancer for the medically disenfranchised. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B46. doi:10.1158/1538-7755.DISP13-B46

Wnt signaling through Dishevelled, Rac and JNK regulates dendritic development

Dendritic arborization is required for proper neuronal connectivity. Rho GTPases have been implicated in the regulation of dendrite development. However, the signaling pathways that impinge on these molecular switches remain poorly understood. Here we show that Wnt7b, which is expressed in the mouse hippocampus, increases dendritic branching in cultured hippocampal neurons. This effect is mimicked by the expression of Dishevelled (Dvl) and is blocked by Sfrp1, a secreted Wnt antagonist. Consistent with these findings, hippocampal neurons from mice lacking Dvl1 show reduced dendritic arborization. Activation of the canonical Wnt-Gsk3beta pathway does not affect dendritic development. In contrast, Wnt7b and Dvl activate Rac and JNK in hippocampal neurons. Dominant-negative Rac, dominant-negative JNK or inhibition of JNK blocks Dvl-mediated dendritic growth. These findings demonstrate a new function for the non-canonical Wnt pathway in dendrite development and identify Dvl as a regulator of Rho GTPases and JNK during dendritic morphogenesis.

Interleukin 1 upregulates ovarian prostaglandin endoperoxide synthase-2 expression: evidence for prostaglandin-dependent/ceramide-independent transcriptional stimulation and for message stabilization

We have recently documented a marked dependence of ovarian prostaglandin endoperoxide synthase (PGS)-2 transcripts, proteins, and activity on interleukin (IL) 1, a putative intermediary in the ovulatory cascade. The purpose of the present study was to characterize the cellular and molecular mechanisms underlying the ability of IL-1beta to upregulate the steady-state levels of ovarian transcripts corresponding to PGS-2. Results of studies designed to enrich or deplete nitric oxide strongly suggest that the stimulatory effect of IL-1beta on ovarian PGS-2 expression is independent of nitric oxide. Utilization of a series of agents designed to simulate or enhance transduction via the sphingomyelin ceramide cycle suggests that the long-term stimulatory effect of IL-1beta on ovarian PGS-2 gene expression is independent of ceramide. In contrast, inhibition of prostaglandin biosynthesis with a series of distinct inhibitors suggests that the ability of IL-1beta to upregulate ovarian PGS-2 transcripts is due, if only in part, to the generation of endogenous prostaglandin estradiol-17beta (E(2)). Inhibition of protein biosynthesis suggested that the IL-1beta-induced PGS-2 gene expression required de novo protein biosynthesis. Our findings revealed substantial IL-1beta-mediated stabilization of PGS-2 transcripts, as assessed by a threefold increase in the half-life of the message. We have also observed the ability of IL-1beta to upregulate the transcription of PGS-2 promoter constructs subjected to transient transfection into whole-ovarian dispersates (twofold increase as assessed by activation of the luciferase reporter gene). Taken together, these findings suggest that the stimulatory effect of IL-1beta on PGS-2 expression is 1) independent of nitric oxide as well as ceramide, 2) dependent on prostaglandin E(2), 3) contingent on de novo protein biosynthesis, and 4) accounted for by both increased transcription and message stabilization. These observations provide indirect support for the hypothesis that IL-1beta, acting in part through PGS-2 (an obligatory ovulatory principal), may constitute a key intermediary in the ovulatory cascade.

Impact of baseline symptom severity on future risk of benign prostatic hyperplasia-related outcomes and long-term response to finasteride. The Pless Study Group

OBJECTIVES

To evaluate the long-term effects of finasteride on symptoms, acute urinary retention (AUR), and the need for benign prostatic hyperplasia (BPH)-related surgery in relationship to baseline symptom severity.

METHODS

A total of 3040 men with BPH were treated for 4 years with finasteride or placebo. The changes from baseline in symptoms and the incidence of BPH-related surgery and AUR were determined in men with mild (less than 8), low-moderate (8 to 12), high-moderate (13 to 19), and severe (greater than 19) baseline quasi-American Urological Association symptoms for all patients and for the subgroup with a baseline prostate-specific antigen (PSA) level of 1.4 ng/mL or greater.

RESULTS

In patients who completed the 4-year study, the change in symptom score, stratified by baseline symptom severity, was +1.4 +/- 0.5 (mild), -0.8 +/- 0.3 (low-moderate), -3.6 +/- 0.3 (high-moderate), and -7.7 +/- 0.5 (severe) in finasteride-treated patients and, respectively, +3.4 +/- 0.5, +0.7 +/- 0.3, -1.4 +/- 0.3, and -5.3 +/- 0.6 in placebo-treated patients (between-group P <0.01). The between-group differences were greater in the subgroup of patients with a baseline PSA of 1.4 ng/mL or greater. The risk of BPH-related surgery increased among placebo patients with increasing baseline symptom severity to a greater extent than the risk of AUR. Finasteride reduced the risk of AUR or the need for BPH-related surgery in all subgroups (P <0.001), especially in men with a baseline PSA of 1.4 ng/mL or greater.

CONCLUSIONS

Compared with placebo, finasteride had a beneficial effect on symptoms, AUR, and BPH-related surgery in all symptom categories. BPH-related surgery, but not AUR, occurred more commonly in placebo-treated men with more severe baseline symptoms. The greatest absolute benefit of finasteride on symptoms and the reduction in risk of AUR and surgery was in men with higher baseline symptom scores and a baseline PSA level of 1.4 ng/mL or greater.

A water channel in the core of the vitamin B(12) RNA aptamer

BACKGROUND

The 3.0 A crystal structure of the vitamin B(12) RNA aptamer revealed an unusual tertiary structure that is rich in novel RNA structural motifs. Important details of the interactions that stabilize noncanonical base pairing and the role of solvent in the structure were not apparent owing to the limited resolution.

RESULTS

The structure of the vitamin B(12) RNA aptamer in complex with its ligand has been determined at 2.3 A resolution by X-ray crystallography. The crystallographic asymmetric unit contains five independent copies of the aptamer-vitamin B(12) complex, making it possible to accurately define well-conserved features. The core of the aptamer contains an unusual water-filled channel that is buried between the three strands of an RNA triplex. Well-ordered water molecules positioned within this channel form bridging hydrogen bonds and stabilize planar base triples that otherwise lack significant direct base-base contacts. The water channel terminates at the interface between the RNA and the bound ligand, leaving a pair of water molecules appropriately positioned to hydrogen bond with the highly polarized cyanide nitrogen of vitamin B(12). Analysis of the general solvation patterns for each nucleotide suggests that water molecules are not precisely positioned, as observed in previous RNA duplex structures, but instead might adjust in response to the varying local environment. Unusual intermolecular base pairing contributes to the formation of three different dimerization contacts that drive formation of the crystal lattice.

CONCLUSIONS

The structure demonstrates the important role of water molecules and noncanonical base pairing in driving the formation of RNA tertiary structure and facilitating specific interactions of RNAs with other molecules.

The 1.3 A crystal structure of a biotin-binding pseudoknot and the basis for RNA molecular recognition

A pseudoknot-containing aptamer isolated from a pool of random sequence molecules has been shown previously to represent an optimal RNA solution to the problem of binding biotin. The affinity of this RNA molecule is nonetheless orders of magnitude weaker than that of its highly evolved protein analogs, avidin and streptavidin. To understand the structural basis for biotin binding and to compare directly strategies for ligand recognition available to proteins and RNA molecules, we have determined the 1.3 A crystal structure of the aptamer complexed with its ligand. Biotin is bound at the interface between the pseudoknot's stacked helices in a pocket defined almost entirely by base-paired nucleotides. In comparison to the protein avidin, the aptamer packs more tightly around the biotin headgroup and makes fewer contacts with its fatty acid tail. Whereas biotin is deeply buried within the hydrophobic core in the avidin complex, the aptamer relies on a combination of hydrated magnesium ions and immobilized water molecules to surround its ligand. In addition to demonstrating fundamentally different approaches to molecular recognition by proteins and RNA, the structure provides general insight into the mechanisms by which RNA function is mediated by divalent metals.

The structural basis for molecular recognition by the vitamin B 12 RNA aptamer

Previous solution structures of ligand-binding RNA aptamers have shown that molecular recognition is achieved by the folding of an initially unstructured RNA around its cognate ligand, coupling the processes of RNA folding and binding. The 3 A crystal structure of the cyanocobalamin (vitamin B12) aptamer reported here suggests a different approach to molecular recognition in which elements of RNA secondary structure combine to create a solvent-accessible docking surface for a large, complex ligand. Central to this structure is a locally folding RNA triplex, stabilized by a novel three-stranded zipper. Perpendicular stacking of a duplex on this triplex creates a cleft that functions as the vitamin B12 binding site. Complementary packing of hydrophobic surfaces, direct hydrogen bonding and dipolar interactions between the ligand and the RNA appear to contribute to binding. The nature of the interactions that stabilize complex formation and the possible uncoupling of folding and binding for this RNA suggest a strong mechanistic similarity to typical protein-ligand complexes.

Expanding the physician's role in pediatric environmental health

In rural Georgia, a nurse and an environmental health specialist from the local health department visit the home of a young nursing mother to evaluate her home for the presence of lead hazards. The mother's older child, a 3-year old girl, has a blood lead level of 22 micrograms per deciliter, which was discovered through routine (EPSTD) health department screening. In examining the home, the specialist finds classic environmental risks; peeling and chipping lead-based paint on windows and door frames, lead dust on window wells and floors, and a backyard that serves as a burial ground for defunct car parts and dead batteries. In the course of talking with the mother about the lead hazards he has found, he notices that she and her 8-week-old infant seem quite listless, so he asks the mother how she's coping with her new baby. Eventually, the mother discloses that during her pregnancy she craved dirt and that she had eaten bowels of it scooped from her backyard. Once she had the baby, she says, she lost her craving. The nurse immediately contacts the physician involved in this case, who arranges for the mother and infant to be admitted to a nearby medical center for chelation therapy. Testing reveals the mother's lead level at 90 micrograms per deciliter; the infant's level is staggering 85 micrograms per deciliter. Once lead levels are reduced,the physician and public health nurse arrange for a host of social services, including psychological and nutritional counseling for the mother and periodic retesting of the children. The family moves from the dilapidated rental home. However, the mother misses her appointments, and despite repeated attempts to locate her, the family is lost to follow-up.

Airbags: an exploratory survey of public knowledge and attitudes

The present study examines public knowledge and opinion in the United States on issues related to airbag safety. Data were obtained through a national random digit-dial telephone survey of 1005 people living in the contiguous 48 United States. A majority of respondents (1) know that airbags can harm drivers seated too close to the steering wheel; (2) know that rear-facing infant seats should not be placed in the front seat of a car with passenger-side airbags; and (3) know that airbags are saving more lives of women drivers than are being lost. However, most respondents did not know that (1) airbags are killing more children than they are saving; (2) airbags can injure properly belted drivers; and (3) the majority of the lives saved by airbags have been among people who were not wearing safety belts. Knowledge of airbag risks to children and properly belted drivers was significantly associated with a less favorable attitude toward airbags, and with opposition toward the law mandating airbags on all new cars. Drivers of vehicles equipped with airbags held more favorable attitudes toward airbag technology. Further analysis suggests that as the public begins to understand the risks associated with airbags, the current high level of public support for the technology and the mandatory regulation may decline.

Current activities at the Centers for Disease Control and Prevention's National Diabetes Laboratory

In 1997, the Centers for Disease Control and Prevention established the National Diabetes Laboratory in order to help prevent and treat type 1 diabetes. This state-of-the-art laboratory collaborates with research scientists and key national and international organizations throughout the world to identify and study risk factors for type 1 diabetes by developing measurements for glycosylated proteins, developing and evaluating technology for measuring genetic risk factors for the disease, and working to standardize autoantibody measurements. Developing improved technologies for diagnosing and managing diabetes and developing reference materials for properly calibrating and standardizing blood glucose meters are also critical aspects of the laboratory's work. In addition, the laboratory provides quality storage for valuable collections of biologics and other materials and facilitates sharing of specimens, associated epidemiologic data, and test results. Working with our partners in diabetes research, we are improving the diagnosis, treatment, and prevention of type 1 diabetes.

Preliminary characterization of crystals of an in vitro evolved cyanocobalamin (vitamin B12) binding RNA

A 35-nucleotide pseudoknot that binds vitamin B12 been isolated using systematic evolution of ligands by exponential enrichment (SELEX). Affinity chromatography was used to purify functional, properly folded molecules and the hanging-drop vapor-diffusion method was used to crystallize this aptamer. Two crystal forms have been obtained and the preliminary crystallographic characterization is reported here. Both crystal forms (space groups I222 or I212121 and C2221) diffract to 2.9 A and should prove sufficient for structure determination.

Unilateral retinoblastoma: new intraocular tumours after treatment

A retrospective chart review of 427 eyes diagnosed with unilateral retinoblastoma was performed to determine which eyes, which patients, and when new intraocular tumours would develop after treatment. Mean follow up was 8.16 years. Twenty five (6%) of 427 unilateral retinoblastoma patients developed new intraocular tumours after treatment. Five (1%) unilateral patients who were previously treated with enucleation developed new tumours (in the fellow eye). Fifteen (24%) unilateral patients who were previously treated with external beam radiation developed new tumours (equally in either eye). New tumours did not develop in the macula of either eye. The relative risk of developing new intraocular tumours after treatment was 16% in patients diagnosed before 1 year old and 2.2% for patients diagnosed after 1 year old (p < 0.001). The mean time to onset for the development of new tumours after treatment was 0.74 years; no new tumours appeared after 7.5 years of age. Those patients who are diagnosed with unilateral retinoblastoma in the first 6 months of life and have a family history of the disease are at greatest risk of developing new intraocular tumours.

Expression and transforming activity of a variant of the heparin-binding fibroblast growth factor receptor (flg) gene resulting from splicing of the alpha exon at an alternate 3'-acceptor site

Splicing at an alternate 3'-acceptor site results in deletion of a CCCAG in the 5'-sequence of the exon coding for the NH2-terminal immunoglobulin-like disulfide loop of the heparin-binding fibroblast growth factor receptor (flg) alpha isoform. The result is an in-frame stop codon 138 base pairs after the first flg consensus translational initiation site. The next more favorable site predicts the same two loop intracellular receptor isoform, gamma, which was predicted from two different human cDNAs that arise by alternate use of two exons at the same site. Although expressed in normal tissue, the gamma mRNA is increased in rat prostate tumors and confers ability of anchorage-dependent cells expressing non-secreted heparin-binding fibroblast growth factors to grow in soft agar.

Radiation regression patterns in treated retinoblastoma: 7 to 21 years later

A retrospective review of cases on file at the Ophthalmic Oncology Center of The New York Hospital-Cornell Medical Center, New York was performed in order to examine the appearance of radiation regression patterns 7 or more years after successful treatment of retinoblastoma with external beam radiotherapy. Forty-eight patients were found to have 89 tumors in 57 eyes which were treated solely with external beam radiation; they were followed for a minimum of 7 years and had sufficient information available for analysis. All but five of the patients had bilateral retinoblastoma. Seventy-four of the 89 tumors continued to be ophthalmoscopically visible after 7 or more years. Taking into account those that did change between the time of first evaluation (usually at the completion of treatment) and final evaluation (7 or more years after treatment), the number of Type I regressions increased by 10.1%, Type IIs decreased by 19.1%, Type IIIs fell by 7.8%, Type IVs rose by 10.1%, and the number of tumors that disappeared increased by 6.8%. Type II remained the most common regression throughout the follow-up. The regression with the greatest potential for change was the Type II regression. The pretreatment volume of the tumor correlated with long-term radiation regression patterns. The smallest tumors (mean size 1.1 dd [disc diameter] or less in size) completely disappeared, while the largest (mean 9.9 dd) became Type I regressions.

Trace anesthetic gases during xenon arc photocoagulation for retinoblastoma

In pediatric ocular examinations, administration of continuous-flow anesthetic gases containing nitrous oxide, halothane, and oxygen enables the physician to do safe, controlled, reproducible examinations. We did a study in which the levels of waste anesthetic gases were measured during xenon arc photocoagulation procedures used for retinoblastoma. Waste nitrous oxide and halothane gases measured during these procedures significantly exceeded the levels recommended by the National Institute of Safety and Health. These high levels are of particular importance because of the physician's proximity to the patient during the procedure. The high levels of waste gases may have immediate deleterious effects on the physician's functioning capacity and may also pose long-term health hazards for the physician and operating room personnel.

Lower limb salvage with autoclaved autogenous tibial diaphysis: case report

A massive crush injury of the lower extremity associated with avulsion of a 30-cm segment of the diaphysis of the tibia is reported. The patient refused consideration of amputation. Therefore, in this unique case, the noncomminuted fragment was autoclaved and replaced as a nonvascularized autogenous graft. Graft-host union was observed without complication, leading to full weight-bearing ambulation with a molded orthosis within 1 year of the injury.

The Pickwickian syndrome with hypertrophy of tonsils: a re-appraisal

Pronounced tonsilar hypertrophy was found in two obese patients suffering from hypersomnolence, periodic attacks of apnea and disturbing snoring at night. Both patients underwent tonsillectomy. Immediately after the operation the hypersomnolence disappeared, the breathing became normal, and the disturbing snoring at night ceased. Follow-up over a period of three years did not reveal any recurrence of these symptoms, even though the patients had not lost any weight during this period.